WO2018199252A1 - Display device - Google Patents

Abstract

Provided is a display device with which it is possible to prevent a non-image region from being visually recognized due to a non-pixel region present between pixel regions of an image source. The display device (1) comprises: an image source (11) in which a plurality of pixels are arrayed and which projects image light; a lens (12) that magnifies the image light (V) and projects the same toward an observer; and an optical sheet (20) that is disposed between the image source (11) and the lens (12), or is disposed on the observer side of the lens (12). The optical sheet (20) comprises, on the interior or surface thereof, at least one optical shape surface in which a convex or concave unit shape extending along the sheet surface is arrayed in a direction orthogonal to the extension direction.

Description

Display device

The present invention relates to a display device that displays an image to an observer.

2. Description of the Related Art Conventionally, a head-mounted display device, a so-called head mounted display (HMD), that allows an observer to observe an image from an image source such as an LCD (Liquid Crystal Display) or an organic EL display through an optical system has been proposed. (For example, patent document 1). Such a head-mounted display device enlarges image light projected from an image source by an optical system such as a lens and displays a clear image to an observer.
An image source used in such a display device includes a plurality of pixel regions that form an image and a non-pixel region that is provided between the pixel regions and does not contribute to image display. When the image light emitted from such an image source is enlarged by a lens, not only the image constituted by the pixel area, but also the non-image area caused by the non-pixel area is enlarged, and only the image is obtained. In addition, the non-image area is also visually recognized by the observer, which may hinder the display of a clear image.

Special table 2011-509417 gazette

An object of the present invention is to provide a display device capable of suppressing a non-video region caused by a non-pixel region existing between pixel regions of a video source from being visually recognized.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The present invention includes an image source (11) in which a plurality of pixels are arranged to emit image light (V), a lens (12) that expands and emits the image light to an observer side, the image source, and the lens Or an optical sheet (20, 40, 60) disposed on the observer side of the lens, and the optical sheet has a convex extending inside or on the surface thereof along the sheet surface. A display device (1) characterized by comprising at least one optical shape surface (201, 202, 401, 402, 601) in which a unit shape of a shape or a concave shape is arranged in a direction orthogonal to the extending direction. is there.

Further, according to the present invention, in an image displayed in a state where the image source (11) and the optical sheet (20, 40, 60) are arranged, light from one pixel is spread by the diffusion action of the optical sheet. The range is a light emitting area (EA), and in the light emitting area, an interval between two farthest points, which is 1/5 of the maximum light amount in the arrangement direction of the unit shapes, is defined as a spread width in the arrangement direction. When the maximum spread width (SW) is used as the maximum spread width among the spread widths, the maximum spread width is a pixel that is a center-to-center distance between the pixel and the pixel that are arranged closest to each other in the image. The display device (1) is characterized in that it is 0.5 to 5 times the closest distance (S).
Further, according to the present invention, in an image displayed in a state where the image source (11) and the optical sheet (20, 40, 60) are arranged, light from one pixel is spread by the diffusion action of the optical sheet. The range is a light emitting area (EA), and in the light emitting area, an interval between two farthest points, which is 1/5 of the maximum light amount in the arrangement direction of the unit shapes, is defined as a spread width in the arrangement direction. The maximum spread width (SW) of the spread widths is defined as the maximum spread width (SW), and the direction in which the center-to-center distance between the pixels is the closest is defined as the first adjacent arrangement direction (DL1). When a direction that is different from the adjacent arrangement direction and in which the center-to-center distance between the pixel and the pixel is next to the first adjacent arrangement direction is the second adjacent arrangement direction (DL2), 1 One or more Among the arrangement directions of the unit shapes, the arrangement direction in which the spread width becomes the maximum spread width forms an angle of 5 degrees or more with respect to the first adjacent arrangement direction and the second adjacent arrangement direction. The display device (1).

According to the present invention, it is possible to provide a display device capable of suppressing the non-video area caused by the non-pixel area existing between the pixel areas of the video source from being visually recognized.

It is a figure explaining the head mounting type display apparatus 1 of 1st Embodiment. FIG. 3 is a diagram of the optical sheet 20, the holding unit 32, and the image source 11 used in the display device 1 of the first embodiment as viewed from the observer side (−Y side). It is a figure explaining the detail of the optical sheet 20 used for the display apparatus 1 of 1st Embodiment. It is a figure explaining the light emission area of one pixel. It is a figure explaining the breadth of a light emission area. It is a figure explaining 1st proximity arrangement direction DL1 and 2nd proximity arrangement direction DL2 in an example of pixel arrangement of picture source 11 of a 1st embodiment. It is a figure explaining the optical sheet 40 of 2nd Embodiment. It is a figure explaining the optical sheet 60 of 3rd Embodiment. It is a figure explaining the specific arrangement direction of optical sheet 60 with an example of pixel arrangement of picture source 11. FIG. FIG. 6 is a diagram schematically illustrating a state in which the optical sheet 20 diffuses the image light V when the optical sheet 60 is arranged with the specific arrangement direction (SZ direction) of the optical sheet 60 being aligned with the third adjacent arrangement direction DL3. is there. The figure which showed typically a mode that the optical sheet 60 diffused the image light V when the specific arrangement direction (SZ direction) of the optical sheet 60 was made to correspond with the 1st proximity arrangement direction DL1, and the optical sheet 60 was arrange | positioned. is there. It is a figure which shows the result of having visually evaluated the appearance of the image observed by arrange | positioning the angle (delta) which shows the specific arrangement direction (SZ direction) of the optical sheet 60 gradually changing. It is a figure explaining the light emission area of one pixel of 4th Embodiment. It is a figure explaining the breadth of the light emission area of 4th Embodiment.

Embodiments of the present invention will be described below with reference to the drawings. In addition, each figure shown below including FIG. 1 is the figure shown typically, and the magnitude | size and shape of each part are exaggerated suitably for easy understanding.
In the present specification, numerical values such as dimensions and material names of each member to be described are examples of the embodiment, and are not limited thereto, and may be appropriately selected and used.
In this specification, terms that specify shape and geometric conditions, for example, terms such as parallel and orthogonal, are strictly meanings, have similar optical functions, and can be regarded as parallel and orthogonal It also includes a state having an error of.

In the present specification, the sheet surface is a sheet-like member that indicates a surface in the planar direction of the sheet when viewed as the entire sheet.
In this specification, the terms “plate”, “sheet”, and the like are used, but these are generally used in the order of thickness, “plate”, “sheet”, “film”. Above all, it uses it. However, there is no technical meaning in such proper use, so these terms can be replaced as appropriate.

(First embodiment)
FIG. 1 is a diagram illustrating a head-mounted display device 1 according to the first embodiment. FIG. 1 shows a state where the display device 1 is viewed from the upper side in the vertical direction.
In the drawings shown below including FIG. 1 and the following description, the vertical direction (vertical direction) is set to the Z direction in a state where the viewer wears the display device 1 on the head for easy understanding. Let the horizontal direction be the X direction and the Y direction. Moreover, among this horizontal direction, let the thickness direction of the optical sheet 20 be Y direction, and let the left-right direction orthogonal to the thickness direction be X direction. In the Y direction, the observer side is the -Y side, and the image source side (back side) is the + Y side.

FIG. 2 is a view of the optical sheet 20, the holding unit 32, and the video source 11 used in the display device 1 of the first embodiment as viewed from the observer side (−Y side).
In FIG. 2, in addition to the XYZ direction described above, SX is shown as a symbol indicating a second direction rotated (tilted) by an angle δ around the Y axis (in the XZ plane). -SY (Y) -SZ is shown. Note that the SY direction coincides with the Y direction described above. The direction of SX-SY-SZ is provided to indicate the arrangement direction of unit shapes of the optical sheet 20 to be described later.
FIG. 3 is a diagram illustrating details of the optical sheet 20 used in the display device 1 of the first embodiment. 3A is a cross-sectional view in a cross section parallel to the arrangement direction and the thickness direction of the unit shapes 21a of the optical sheet 20, and FIG. 3B is a cross-sectional view of a portion b in FIG. FIG. 3C is a diagram showing details of the portion c in FIG. 3A, and FIG. 3D is a diagram showing details of the portion d in FIG. 3B.

The display device 1 is a so-called head mounted display (HMD) that is attached to the head of an observer and displays an image in front of the eyes of the observer. As shown in FIG. 1, the head-mounted display device 1 according to this embodiment includes an image source 11, lenses 12 (12 </ b> A, 12 </ b> B), and an optical sheet 20 (20 </ b> A, 20 </ b> B) inside a housing 30. By mounting the case 30 on the head so that it is in front of the observer's eyes, the image displayed on the image source 11 is passed through the optical sheet 20 and the lens 12 to the observer's eyes E1. , E2 can be visually recognized.
In the following description, since the lenses 12A and 12B have the same shape, they will be collectively described as the lens 12 as appropriate. Further, since the optical sheets 20A and 20B have the same shape, the optical sheets 20 will be described together as appropriate. The same applies to second to fourth embodiments described later.
In FIG. 1, the display device 1 will be described by taking an example in which an image is displayed on both eyes E1 and E2 of the observer. However, the display apparatus 1 is not limited to this. For example, the eye E1 on one side of the observer is used. The image may be displayed with respect to the eye E1.

The housing 30 is a rectangular box-shaped housing that is horizontally long in the left-right direction, and a holding unit 31 that holds the image source 11, a holding unit 32 that holds the optical sheet 20 (20 </ b> A, 20 </ b> B), and a lens inside thereof. 12 (12A, 12B) is provided. The housing 30 can be attached to the observer's head by a belt (not shown) or the like.
The holding unit 31 is a member that holds the image source 11. On the display surface 11 a side of the image source 11, openings 311 A and 311 B are provided at positions corresponding to the eyes E 1 and E 2 of the observer and the lenses 12 A and 12 B. have. In the present embodiment, the video source 11 is detachably held by the holding unit 31 (that is, the display device 1).

The holding unit 32 is a member that is positioned closer to the observer side (−Y side) than the holding unit 31 and the image source 11 and holds the optical sheet 20. In the holding part 32, the optical sheets 20A and 20B are held in the opening parts 321A and 321B provided at positions corresponding to the opening parts 311A and 311B, respectively.

The holding unit 33 is a member that is positioned closer to the observer side (−Y side) than the holding unit 32 and the optical sheet 20 and holds the lenses 12A and 12B. The holding portion 33 has openings 331A and 331B at positions corresponding to the optical sheets 20A and 20B, and the lenses 12A and 12B are held in the openings 331A and 331B, respectively.

The image source 11 is a display element (micro display) that emits image light V and displays an image on the display surface 11a. For example, a transmissive liquid crystal display device, a reflective liquid crystal display device, an organic EL, or the like is used. Can be used. The image source 11 of this embodiment uses an organic EL display with a diagonal of 5 inches.
The video source 11 is held by the holding unit 31 so that the display surface 11a is on the viewer side (−Y side).

The lenses 12 (12A, 12B) are convex lenses that magnify the image light V emitted from the image source 11 and emit it to the viewer side. In the present embodiment, the image source 11 and the optical sheet 20 (20A, 20B) are arranged closer to the observer side (−Y side). The lens 12 is made of glass or resin with high translucency.
A reflection suppression layer 12 a is formed on the surface of the lens 12 on the image source side (back side, + Y side).

The optical sheet 20 (20A, 20B) is disposed between the image source 11 and the lens 12, as shown in FIG. The optical sheet 20 has a diffusion function that slightly diffuses the image light V emitted from the image source 11.

In FIG. 1, the optical sheet 20 and the display surface 11a of the image source 11 are separated from each other by a predetermined dimension. However, the present invention is not limited to this, and the optical sheet 20 and the display surface 11a of the image source 11 are separated. An intermediate layer is provided between the display surface 11a of the image source 11 and the surface on the viewer side of the optical sheet 20, and reaches at least the viewer's eyes E1 and E2 of the image light V. The air layer may not be present in the region where the light to be transmitted (the light visually recognized by the observer) is transmitted.
In this case, light that reaches between the display surface 11a of the image source 11 and the surface on the viewer side of the optical sheet 20 and reaches the viewer's eyes E1 and E2 of at least the image light V (light that the viewer sees). ) Is preferably less than 0.3 at the interface between the members in the region where the light is transmitted. By adopting such a configuration, it is possible to reduce a light amount loss of the image light V due to interface reflection, suppress stray light, and the like.
Such an intermediate layer can be appropriately employed depending on the desired optical performance or the like, and examples thereof include an index matching resin. The index matching resin may have a function of determining the position of the optical sheet 20 and supporting the position.
In addition, for example, the optical sheet 20 may be integrally laminated on the display surface 11a without including the intermediate layer.

2. Description of the Related Art Conventionally, head-mounted display devices that are mainly used (hereinafter referred to as comparative display devices) are not provided with the optical sheet 20 described above, and the image light V emitted from the image source is used. The image was magnified by a lens and displayed on the observer.
In the display such as the organic EL used for the image source 11 of the present embodiment and the image source of the comparative example, a plurality of pixels for forming an image are arranged on the display layer, and an image is formed between the pixels. Non-pixel regions that do not contribute are provided. Therefore, in the display device of the comparative example, when the image displayed by the image light V emitted from the image source is enlarged through the lens, the image is displayed not only in the image region by the image light emitted from the pixel but also in the non-pixel region. The resulting non-video area is also enlarged. In addition, the non-image area is clearly visually recognized by the observer, which may hinder clear image display.

On the other hand, in the display device 1 of the present embodiment, by providing the optical sheet 20 described above, the video light V emitted from the video source 11 is slightly diffused, and the non-video is generated by the diffused video light V. It can suppress that an area | region is visually recognized by the observer.

As shown in FIG. 3, the optical sheet 20 of the present embodiment has a first optical layer 21 and a second optical layer 22 laminated in order from the image source side (back side, + Y side). In the optical sheet 20, a plurality of unit shapes 21a and unit shapes 22a are formed and arranged on the interface 201 between the first optical layer 21 and the second optical layer 22 and the interface 202 between the second optical layer 22 and air, respectively. ing. That is, the interfaces 201 and 202 are both optically shaped surfaces, and the optical sheet 20 includes two optically shaped surfaces.
In FIG. 2, the SX direction and the SZ direction that are parallel to the sheet surface of the optical sheet 20 and are orthogonal to each other are described. These two directions coincide with the arrangement directions of the unit shapes provided in the optical sheet 20 of the present embodiment. In the example of FIG. 2, the arrangement direction of each unit shape of the optical sheet 20 is arranged to be inclined (rotated) with respect to the X direction and the Z direction by an angle δ.
In the present embodiment, the outer shape of the optical sheet 20 is basically a circle as shown in FIG. 2, but is not limited to this.

The first optical layer 21 is a layer that is located on the image source side (+ Y side) with respect to the second optical layer 22 in the thickness direction (Y direction) of the optical sheet 20 and has optical transparency. The image source side surface of the first optical layer 21 is formed substantially flat. As shown in FIG. 2A, the first optical layer 21 on the viewer side (−Y side), that is, the interface 201 between the first optical layer 21 and the second optical layer 22 has a convex shape. A plurality of unit shapes 21a are formed. In the present embodiment, the unit shape 21a is convex on the viewer side.

The second optical layer 22 is a light-transmitting layer located on the viewer side (−Y side) of the first optical layer 21. The surface on the viewer side of the second optical layer 22 is a surface from which the image light transmitted through the optical sheet 20 is emitted (interface 202 with the air). As shown in FIG. A plurality of 22a are formed. In the present embodiment, the unit shape 22a is convex on the viewer side.

The unit shapes 21a extend in the SZ direction along the observer-side (-Y side) surface 201 of the first optical layer 21, and a plurality of unit shapes 21a are arranged in the SX direction orthogonal to the extending direction. The unit shapes 22a extend in the SX direction along the surface 202 on the viewer side of the second optical layer 22, and a plurality of unit shapes 22a are arranged in the SZ direction orthogonal to the extending direction.
The unit shapes 21a and 22a are lenticular lens shapes in which a cross-sectional shape in a plane parallel to each arrangement direction and the thickness direction of the optical sheet 20 is formed in a substantially arc shape. Here, the “substantially arc shape” means not only a perfect circular arc but also a curved shape including a part such as an ellipse or an ellipse. In the present embodiment, as an example, the sectional shapes of the unit shapes 21a and 22a are substantially arc-shaped as described above, but the present invention is not limited to this.
The arrangement pitch of the unit shapes 21a and 22a of this embodiment is P1 and P2, and the arcuate curvature radii are R1 and R2.

In the present embodiment, when viewed from the thickness direction (Y direction) of the optical sheet 20, the arrangement direction (SX direction) of the unit shapes 21a and the arrangement direction (SZ direction) of the unit shapes 22a are orthogonal to each other. The extending direction (SX direction) of 21a and the extending direction (SX direction) of the unit shape 22a are orthogonal to each other.
In the present embodiment, an example in which the arrangement direction (SX direction) of the unit shapes 22a and the arrangement direction (SZ direction) of the unit shapes 21a are orthogonal to each other when viewed from the thickness direction (Y direction) of the optical sheet 20 is shown. However, the intersecting angle need not be a right angle.

The first optical layer 21 has a plurality of light-transmitting ultraviolet curable resins and the like on the surface of a base material layer formed of a PC (polycarbonate) resin, a PET (polyethylene terephthalate) resin, or the like having a high light transmittance. The unit shape 21a is formed and formed.
The second optical layer 22 is made of an ultraviolet curable resin or the like with high light transmittance.
In the present embodiment, the unit shape 21 a of the first optical layer 21 is formed of a material having a higher refractive index than that of the second optical layer 22.

Further, in the optical sheet 20 of the present embodiment, the refractive index difference between regions adjacent to each other via the interface 201 (optical shape surface), that is, the refractive index difference Δn1 between the unit shape 21a and the second optical layer 22 is 0. It is preferably formed so as to satisfy 0.005 ≦ Δn1 ≦ 0.2.
When this refractive index difference Δn1 is less than 0.005, the image light is hardly refracted at the interface 201, and a sufficient diffusing action is not exhibited. Further, in this case, the dispersion of the refractive index of the resin has a great influence on the diffusion characteristics, and the influence of the wavelength dispersion becomes large.
When the refractive index difference Δn1 is larger than 0.2, the light refraction at the interface 201 becomes too large, the diffusing action becomes too large, and it becomes difficult to adjust the diffusivity.

Furthermore, the optical sheet 20 of the present embodiment is provided with a reflection suppression layer (not shown) on at least one of the image source side (+ Y side) surface and the viewer side (−Y side) surface.
The antireflection layer provided on the optical sheet 20 may be the same antireflection layer as the antireflection layer 12 a provided on the image source side of the lens 12.
In addition, a layer having a hard coat function, an antifouling function, an antistatic function, or the like may be appropriately provided on the image source side (+ Y side) or the viewer side (−Y side) of the optical sheet 20.

Next, the action of diffusing the image light V of the optical sheet 20 will be described.
As described above, the optical sheet 20 suppresses the observer from visually recognizing the non-image area caused by the non-pixel area by the action of diffusing the image light V.
If the diffusing action by the optical sheet 20 is too strong, the image light V is diffused more than necessary, and the quality of the image deteriorates, such as blurring of the image. On the other hand, if the diffusion action by the optical sheet 20 is too weak, the non-image area will be visually recognized by the observer. Therefore, the optical sheet 20 must have an appropriate diffusing action.
Further, the optimum intensity of the diffusing action by the optical sheet 20 varies depending on the positional relationship with the image source 11 and the lens 12. In addition, since the unit shapes are arranged in a predetermined direction on the optical sheet 20, the positional relationship between the arrangement direction and the pixels also affects the effect of making it difficult for the observer to visually recognize the non-image area. .

Since the image light V from the image source 11 is diffused by the optical sheet 20 and further magnified by the lens 12 and observed by the observer, the component of the light diffused in the range actually observed by the lens 12 is important. It is. Further, the optical sheet 20 includes an interface 201 (optical shape surface) in which a plurality of unit shapes 21a are arranged, and an interface 202 (optical shape surface) in which the plurality of unit shapes 22a are arranged. Diffused.

(Regarding the spread of light)
The diffusing action of diffusing the image light of the optical sheet 20 will be described from the viewpoint of the spread of light emitted from the pixels.
The light emitted from one pixel provided in the video source 11 has its light range (hereinafter referred to as a light emitting area) expanded mainly by the diffusion action of the optical sheet 20. Therefore, the directivity and the magnitude of the light diffusing action of the optical sheet 20 can be defined by the direction and the size of the light emitting area widened by the optical sheet 20 and the size thereof.
FIG. 4 is a diagram illustrating a light emitting area of one pixel. FIG. 4A is an observation image obtained by enlarging an image displayed by the image source 11 with a digital microscope or the like without using the lens 12 and the optical sheet 20, and shows a state of light emitted from one pixel. . FIG. 4B is an observation image obtained by enlarging an image displayed in a state where the image source 11 and the optical sheet 20 are combined and arranged without using the lens 12, and shows the state of light emitted from one pixel. Show.

When the light emitted from the pixel does not pass through the optical sheet 20 or the like, as shown in FIG. 4A, the light emitting area EA0 is observed as a shape close to the shape of the light emitting portion of the pixel (for example, a circular shape). Is done. Then, by receiving the diffusing action of the optical sheet 20, the light emitted from the pixels is spread mainly along the SX direction and the SZ direction, which are the arrangement directions of the unit shapes 21a and 22a, as shown in FIG. As shown, the light emitting area EA is observed as a shape spreading in a rectangular shape.
Further, depending on the distance between the optical sheet 20 and the pixels of the image source 11 (display layer on which the pixel and non-pixel areas are formed), the arrangement pitches P1 and P2 of the unit shapes 21a and 22a of the optical sheet 20, etc. In some cases, the ratio of the amount of light emitted and diffused by diffraction in the unit shapes 21a and 22a to the light emitted from the light increases. In that case, the light emitting area EA expands in the arrangement direction (SX direction, SZ direction) of the unit shapes 21a and 22a by diffusion and is also expanded by diffracted light, and a large amount of light (bright region) generated by diffraction is It is observed as a portion where the luminance is intermittently increased in a plurality of grains in the light emitting area EA.

The light emitting area EA has a shape close to a square when the size of the diffusing action on the two optical shape surfaces (interfaces 201 and 202) on which the unit shapes 21a and 22a are formed is equal. In addition, when the magnitudes of the diffusing action on the two optical shape surfaces are not equal, of the two diagonal lines, the one parallel to the arrangement direction of the unit shape having the larger diffusing action has a longer rhombus shape than the other. It may be a close shape or a rectangle.
In the present embodiment, the diffusion action on the optical shape surface (interface 202) on which the unit shape 22a is formed is slightly larger than the diffusion action on the optical shape surface (interface 201) on which the unit shape 21a is formed. It is assumed that EA has a rhombus shape in which the diagonal line parallel to the SZ direction is longer than the other of the two diagonal lines.

FIG. 5 is a diagram for explaining the spread width of the light emitting area. Each graph shown in FIG. 5 shows, for example, the distribution of the light quantity in the SZ direction that is the arrangement direction of the unit shapes 22a, the vertical axis shows the light quantity, and the horizontal axis shows the position in the SZ direction.
The graph shown in FIG. 5A is an example of the light amount distribution of one light emitting area EA0 in an observation image obtained by enlarging an image displayed by the image source 11 with a digital microscope or the like without using the lens 12 and the optical sheet 20. Show. Each graph shown in FIG. 5B shows the amount of light of one light emitting area EA in an observation image obtained by enlarging an image displayed without using the lens 12 and in a state where the image source 11 and the optical sheet 20 are arranged in combination. An example of the distribution is shown. The graph shown in FIG. 5B is an example in the case where the ratio of the diffusion action due to refraction in the unit shapes 21 a and 22 a is high in the light emitted from the optical sheet 20.

Here, in the light emission area EA of one pixel, the spread width of the light emission area EA in the arrangement direction of the unit shape 21a or the unit shape 22a is an image displayed in a state where the image source 11 and the optical sheet 20 are arranged in combination. , The two most distant points (points t1 and t2 in FIG. 5B) that are 1/5 of the maximum value of the light quantity in the direction along the arrangement direction of the unit shapes of the light emitting area EA. Defined as an interval. Among the spread widths, the maximum value (the larger one) is set as the maximum spread width SW.
If the unit shapes 21a and 22a have the same diffusing action in the arrangement direction (when the light emitting area EA is square), the spreading width in each arrangement direction is the maximum spreading width SW.

The maximum spreading width SW of the light emitting area EA is the distance between the pixels that are closest to each other in the above-described image (distance between the centers) (hereinafter, the distance between the pixels is the distance between the centers of the pixels). And the closest distance S of the pixel (the distance between the centers of the pixels in the first adjacent arrangement direction DL1 to be described later) is 0.5 times or more and 5 times or less. preferable.
When the maximum spread width SW is less than the above range, the non-image area between the light emitting areas EA of adjacent pixels becomes large, and the non-image area is easily seen by the observer in the usage state of the display device 1. Is not preferable.
In addition, when the maximum spread width SW is larger than the above range, the light emitting areas of adjacent pixels are largely overlapped, which is not preferable because blurring of an image becomes larger than necessary.

Note that, in an image displayed in a state where the image source 11 and the optical sheet 20 are arranged in combination, the maximum value of the light amount of the light emitting area EA in the arrangement direction of each unit shape or a value that is 1/5 of the maximum value, The positions of the two points t1 and t2 and the distance between the two points t1 and t2 are determined based on the video signal (coordinate information in the image and the coordinate information in the image). The correlation between the position in the light emitting area EA and the brightness can be detected from the signal intensity) and calculated.
Further, the closest distance S of the pixels in the image displayed in a state where the image source 11 and the optical sheet 20 are arranged in combination is the same as the image displayed by the image source 11 without using the lens 12 and the optical sheet 20. The closest distance S can be calculated from the observation image captured by enlarging the image, and the closest distance S is the distance between the centers of the pixels closest to each other in the video display area (display layer) of the video source 11. Note that the closest distance S of the pixels can be calculated from an observation image obtained by similarly enlarging an image displayed in a state where the image source 11 and the optical sheet 20 are combined and arranged. For the sake of convenience, it is desirable to calculate from the observation image obtained by enlarging the image displayed by the image source 11 in the same manner.

(Regarding pixel arrangement and arrangement direction of unit shape of optical sheet)
Next, the relationship between the pixel arrangement of the video source 11 and the arrangement direction (SX direction, SZ direction) of the unit shapes 21a and 22a of the optical sheet 20 will be described.
FIG. 6 is a diagram illustrating the first adjacent arrangement direction DL1 and the second adjacent arrangement direction DL2 in an example of the pixel arrangement of the video source 11 according to the first embodiment.
Depending on the type of the image source 11, when the proportion of the area occupied by the pixels in the image display region of the image source 11 is small (that is, the proportion occupied by the non-pixel region is large), the arrangement direction of the unit shapes 21a and 22a of the optical sheet 20 Depending on the angle formed by the (SX direction, SZ direction) with respect to the arrangement direction of the pixels of the image source 11, the image light emitted from the pixels is not sufficiently diffused to the non-pixel region side, and the non-image region is easily noticeable.

In FIG. 6, as an example of the pixel arrangement of the video source 11 of the present embodiment, the pixels G0 are arranged in a square lattice pattern in the vertical and horizontal directions (X direction and Z direction) of the rectangular video display area of the video source 11. An example is shown. Here, regardless of the emission color (R, G, B) of the pixel G0, attention is paid to the distance between the center positions of the pixels G0. The differences are not shown. In FIG. 6, the pixels G0 are arranged at equal intervals in the vertical and horizontal directions of the rectangular display area. In addition, although the shape of the pixel G0 has shown the example which is circular shape as an example in FIG. 6, it is not limited to this.
In FIG. 6, as an example, the following direction is defined by the distance between the pixel centers (center-to-center distance) with an arbitrary pixel GA below in the figure as a reference. Note that the reference pixel GA is set for explanation for easy understanding, and it is not necessary to determine one specific pixel as a reference.

(First proximity arrangement direction DL1)
A direction in which the distance between the pixel centers is the closest from the appropriately selected reference pixel GA is defined as a first adjacent arrangement direction DL1. In the present embodiment, the angle formed by the first adjacent arrangement direction DL1 and the Z direction is 0 degrees.

(Second adjacent arrangement direction DL2)
A direction that is different from the first adjacent arrangement direction DL1 and in which the center-to-center distance between the pixels is next to the first adjacent arrangement direction DL1 is defined as a second adjacent arrangement direction DL2. In the present embodiment, the angle formed by the second adjacent arrangement direction DL2 and the Z direction is 45 degrees.

Temporarily, among the arrangement directions (SX direction, SZ direction) of the unit shapes 21a and 22a, the arrangement direction of the unit shape that is the direction of the maximum spread width SW (in this embodiment, the SZ direction that is the arrangement direction of the unit shapes 22a). And the first proximity arrangement direction DL1 coincide with each other, the spread of the image light to the non-pixel region of the image source 11 is small, and the region where the non-image region is visually recognized becomes large.
The same applies to the case where the direction of the maximum spreading width SW matches the second adjacent arrangement direction DL2.

Therefore, among the arrangement directions of the unit shapes 21a and 22a of the optical sheet 20, the direction of the maximum spread width SW is at an angle of 5 degrees or more with respect to the first adjacent arrangement direction DL1 and the second adjacent arrangement direction DL2. The optical sheet 20 is preferably disposed.
By arranging the optical sheet 20 so that the arrangement direction of each unit shape is in the above-described direction with respect to the pixels of the video source 11, it is possible to suppress the non-video region from being visually recognized. .

The display device 1 can suppress a non-video region from being visually recognized and display a good image by satisfying the above-described conditions for the light emitting area EA.
In the present embodiment, a form in which the rectangular display area is arranged in a square lattice pattern in the up / down / left / right direction is shown. In this case, the pixel may be arranged in a square lattice pattern. Further, the arrangement of the pixels of the video source 11 may be appropriately selected.

(Diffusion degree D)
Next, a preferable range of the diffusion action of the optical sheet 20 will be described from another viewpoint.

For example, when the image source 11 is an organic EL display, a transparent substrate, a transparent electrode, an organic hole transport layer, an organic light emitting layer (display layer), an organic electron transport layer, a metal electrode, and the like are sequentially arranged from the observer side. A plurality of layers are laminated. The non-pixel region and the pixel are formed in the display layer.
In the Y direction, when the distance between each optical shape surface on which each unit shape is formed and the pixel (display layer) of the image source 11 is L, this distance L is the height of each unit shape from the display layer. It is preferable to reach the position where the average height is reached.

Here, of the refractive indexes of the regions adjacent to each other through the interface (optical shape surface) on which the unit shape is formed, the higher refractive index is defined as na, and the lower refractive index is defined as nb. At this time, the diffusivity D representing the degree to which the video light V is diffused by the unit shape can be defined as follows.
D = (P / R) × (1− (nb / na)) × L
Note that P is the arrangement pitch of the unit shape, and R is the radius of curvature of the unit shape.

The diffusivity D also represents the degree to which the optical shape surface on which the unit shape is formed diffuses light. The diffusivity D and the distance between the pixels closest to each other and the center of the pixel are the same. The ratio D / S to the closest distance S can be used as an index representing the degree of suppression of the non-image area being visually recognized by the observer due to its optical shape surface.

Next, when various parameters were changed to create a plurality of types of optical sheets 20 and the actual appearance was evaluated, when the ratio D / S satisfies the following formula, it is difficult for the observer to visually recognize the non-image area. It has been found that it is possible to provide a good image in which the video area cannot be seen independently and the video is not too blurred.
1.0 ≦ D / S ≦ 10.0 (Formula 1)
If D / S is less than 1.0, the video area is seen independently by the observer, and the non-video area is also visually recognized by the observer. Further, when D / S is larger than 10.0, the viewer visually recognizes the image as blurred. Therefore, it is preferable that D / S satisfies the above formula in each optical shape surface.

Moreover, it is more preferable that each optical shape surface satisfies the following expression, which is a stricter condition.
2.0 ≦ D / S ≦ 6.0 (Formula 2)
When the above formula is satisfied for each optical shape surface, an optimal image is provided in which the non-image area is hardly visually recognized by the observer, the image area formed by each pixel is not independently viewed, and the image is not excessively blurred. Was possible.

Thus, with respect to the optical sheet 20, when the D / S satisfies a preferable range in the optical shape surface, the display device 1 uses the optical sheet 20 to convert the video light V emitted from the video source 11 into the arrangement direction of the unit shapes 21 a. (SX direction) and unit shape 22a can be slightly diffused in the arrangement direction (SZ direction), and a clear image is displayed to the observer, and the non-image area is prevented from being visually recognized by the minute diffusion of the image light V. can do.

If the cross-sectional shape of the unit shapes 21a and 22a is an elliptical shape or a partial shape of an ellipse and is not a complete arc, the shape is approximated by an arc and the radius of the arc shape is set to R1, What is necessary is just to calculate as R2.

(Regarding the arrangement pitch P of the unit shape and the distance L between the optical shape surface and the pixel)
Next, the relationship between the arrangement pitch P of unit shapes and the distance L between the optical shape surface on which the unit shapes are formed and the pixels (display layer) of the video source 11 will be described. According to the distance L, the optical sheet 20 has a preferable arrangement pitch P of unit shapes provided on its optical shape surface. The display device 1 preferably satisfies the following formula.
0.005 ≦ P / L ≦ 0.05 (Formula 3)
Moreover, it is more preferable to satisfy | fill the following formula | equation.
0.01 ≦ P / L ≦ 0.03 (Formula 4)

When P / L is smaller than 0.005, the distance between the unit shape and the pixel (display layer) is too far, so that the parallelism of light incident on the optical sheet 20 becomes high, or the pitch of the unit shape is small. In some cases, the diffraction phenomenon of light due to the unit shape is likely to occur, the influence of the diffracted light becomes too great, and a sufficient degree of diffusion cannot be obtained, or the image may become unclear. If the arrangement pitch is too small, it is difficult to manufacture unit shapes.
When P / L is larger than 0.05, the distance between the unit shape and the pixel (display layer) is too short, and moire is likely to occur between the pixel and the unit shape.

As shown in FIG. 1, the video light V emitted from the video source 11 is incident on the optical sheet 20 and is formed by a plurality of unit shapes 21 a formed at the interface 201 between the first optical layer 21 and the second optical layer 22. Then, the light is slightly diffused in the arrangement direction (SX direction) of the unit shapes 21 a and enters the second optical layer 22.
The image light V is slightly diffused in the arrangement direction (SZ direction) of the unit shapes 22a by a plurality of unit shapes 22a formed at the interface 202 between the second optical layer 22 and air, and the observer of the optical sheet 20 The light is emitted from the side (−Y side) surface.
The image light V transmitted through the optical sheet 20 is magnified by the lens 12 and emitted to the viewer side.

According to the present embodiment, since the display device 1 satisfies the above-described conditions, the video light V emitted from the video source 11 can be slightly diffused, and a clear video is displayed to the observer and the video is displayed. It is possible to prevent the viewer from seeing the non-video region caused by the non-pixel region of the video source 11 without the region being viewed independently.

(Second Embodiment)
The optical sheet 40 of the second embodiment includes the third optical layer 43 on the observer side (−Y side) of the second optical layer 22, and the unit shape 42 a includes the second optical layer 42, the third optical layer 43, and the like. This is different from the optical sheet 20 of the first embodiment in that it is formed at the interface 402.
Therefore, in the following description of the second embodiment and the third and fourth embodiments to be described later, parts having the same functions as those of the first embodiment described above are denoted by the same reference numerals or the same reference numerals at the end. Thus, overlapping description will be omitted as appropriate. In the second to fourth embodiments, differences from the first embodiment will be mainly described.
FIG. 7 is a diagram illustrating the optical sheet 40 of the second embodiment. Fig.7 (a) is sectional drawing in the cross section parallel to the sequence direction and thickness direction of the unit shape 41a of the optical sheet 40, FIG.7 (b) is b section sectional drawing of Fig.7 (a). FIG. 7C is a diagram showing details of the portion c in FIG. 7A, and FIG. 7D is a diagram showing details of the portion d in FIG. 7B.

As shown in FIG. 7, in the optical sheet 40 of the second embodiment, a first optical layer 41, a second optical layer 42, and a third optical layer 43 are laminated in this order from the image source side (+ Y side).
This optical sheet 40 has unit shapes 41a and unit shapes 42a at the interface 401 between the first optical layer 41 and the second optical layer 42 and at the interface 402 between the second optical layer 42 and the third optical layer 43, respectively. Multiple arrays are formed. In other words, the optical sheet 40 includes two optical shape surfaces (interfaces 401 and 402).

The first optical layer 41 and the unit shape 41a correspond to the first optical layer 21 and the unit shape 21a of the first embodiment described above. The second optical layer 42 and the unit shape 42a correspond to the second optical layer 22 and the unit shape 22a of the first embodiment.
The third optical layer 43 is a light-transmitting layer provided on the viewer side (−Y side) of the second optical layer 42. The surface on the viewer side of the third optical layer 43 is formed substantially flat. The third optical layer 43 of this embodiment is formed of an ultraviolet curable resin or the like with high light transmittance.
The third optical layer 43 is made of a resin having a high light transmittance and a refractive index higher than that of the second optical layer 42, and a refractive index difference Δn 2 between the second optical layer 42 and the third optical layer 43. Satisfies 0.005 ≦ Δn2 ≦ 0.2.

Also in this embodiment, the display device 1 can slightly diffuse the image light V emitted from the image source 11 by satisfying each condition as in the first embodiment, and a clear image can be displayed to the observer. In addition to displaying, it is possible to prevent the viewer from visually recognizing the non-video region caused by the non-pixel region because the video region cannot be seen independently.

Moreover, according to this embodiment, since both surfaces of the optical sheet 40 become a plane by providing the 3rd optical layer 43, it is easy to handle and manufacture of the display apparatus 1 becomes easy.
Further, according to this embodiment, since the third optical layer 43 is provided on the observer side of the second optical layer 42, the third optical layer 43 is provided with a reflection suppressing function, a hard coat function, an antistatic function, and the like. Layer.

(Third embodiment)
The optical sheet 60 of the third embodiment includes a first optical layer 61 and a second optical layer 62 laminated on the viewer side (−Y side), and a unit shape 61a is formed at the interface 601 between the two layers. The optical sheet 20 is different from the optical sheet 20 of the first embodiment in that a plurality of optical surfaces are formed.
FIG. 8 is a diagram illustrating the optical sheet 60 according to the third embodiment. FIG. 8A is a cross-sectional view in a cross section parallel to the thickness direction of the optical sheet 60 and the longitudinal direction of the unit shapes 61a, and FIG. 8B is the thickness direction of the optical sheet 60 and the arrangement direction of the unit shapes 61a. FIG. FIG. 8C is a diagram showing details of the portion c in FIG. 8A, and FIG. 8D is a diagram showing details of the portion d in FIG. 8B.

As shown in FIG. 8, in the optical sheet 60 of the third embodiment, a first optical layer 61 and a second optical layer 62 are laminated in order from the image source side (+ Y side). The optical sheet 60 has a reflection suppressing layer (not shown) on both surfaces.
The optical sheet 60 is formed by arranging a plurality of unit shapes 61a at the interface 601 between the first optical layer 61 and the second optical layer 62, and the interface 601 is an optical shape surface. The unit shape 61a is the same as the unit shape 21a of the first embodiment described above except that the SX direction is the longitudinal direction and is arranged in the SZ direction.
The first optical layer 61 and the second optical layer 62 correspond to the first optical layer 21 and the second optical layer 22 of the first embodiment described above, and are formed of the same materials.

Also in the present embodiment, the maximum spread width SW of the light emitting area EA by the optical sheet 60 is preferably not less than 0.5 times and not more than 5 times the closest distance S of the pixels. In the present embodiment, the maximum spread width SW is in the arrangement direction (SZ direction) of the unit shapes 61a.
Also in the present embodiment, the optical sheet 60 is arranged such that the arrangement direction (SZ direction) of the unit shapes 61a forms an angle of 5 degrees or more with respect to the first and second adjacent arrangement directions DL1 and DL2. 60 is preferably located relative to the video source 11.

Further, in the present embodiment, the following formula is satisfied from the viewpoint that the non-video area is not easily seen by the observer, the video area is not seen independently, and the video is not too blurred and provides a good image. Is preferred.
1.0 ≦ D / S ≦ 15.0 (Formula 5)
Further, it is more preferable to satisfy the following formula.
2.0 ≦ D / S ≦ 6.0 (Formula 6)
In the above two formulas, as described above, D is the diffusivity of the unit shape 61a (optical shape surface 601), and S is the closest distance of the pixel.

According to the present embodiment, by satisfying each condition as in the first embodiment, the display device 1 can slightly diffuse the video light V emitted from the video source 11, and a clear image for the observer. , And the video area is not seen independently, and it is possible to suppress the non-video area caused by the non-pixel area between the pixels from being viewed by the observer.

Moreover, according to this embodiment, since the optical sheet 60 has only one optical shape surface, the manufacturing is easy, and the production cost of the optical sheet 60 and the display device 1 can be suppressed.
In addition, according to the present embodiment, both surfaces of the optical sheet 60 are flat as shown in FIG. 8, which is easy to handle and manufacture of the display device 1 is facilitated.

In this embodiment, the optical shape surface on which a plurality of unit shapes are arranged is the interface 601 between the first optical layer 61 and the second optical layer 62. However, the present invention is not limited to this. May be an interface 602 between the second optical layer 62 and air.
Further, in the present embodiment, the unit shapes 61a are illustrated as being arranged in the SZ direction. However, the unit shapes 61a are not limited thereto, and may be arranged in the SX direction.

(Fourth embodiment)
The display device 1 of the fourth embodiment includes an optical sheet similar to the optical sheet 60 of the third embodiment, and the display device of the first embodiment is that the pixel array of the video source 11 is a diamond pen tile array. Different from 1.
The optical sheet 60 of the present embodiment is the same as the optical sheet 60 of the third embodiment described above, and the extending direction of the unit shapes 61a is the SX direction, and the arrangement direction is the SZ direction. The optical sheet 60 is arranged such that its specific arrangement direction (the SZ direction, which is the arrangement direction of the unit shapes 61a) is inclined with respect to the Z direction of the video source 11 by an angle δ.

FIG. 9 is a diagram illustrating a specific arrangement direction of the optical sheet 60 together with an example of a pixel arrangement of the video source 11.
As described above, the main purpose of providing the optical sheet 60 is to prevent the non-image area due to the non-pixel area between the pixels from being noticeable when the image source 11 is enlarged and observed. is there. This phenomenon tends to be particularly noticeable in the organic EL display. This is because an organic EL display tends to have a low ratio of an area occupied by pixels (hereinafter referred to as a pixel area) in a video display area (display layer). In particular, when the ratio of the pixel area in the video display area of the video source 11 is 50% or less, particularly 30% or less, the effect of the optical sheet 20 is more exhibited. In the case of this embodiment shown in FIG. 9, the ratio of the pixel area in the video display area of the video source 11 is about 20%.

As an example of the pixel arrangement in the organic EL display, a diamond pen tile arrangement shown in FIG. 9 is known. In this diamond pen tile arrangement, the pixels are arranged in a square lattice pattern in a direction inclined 45 degrees with respect to the vertical and horizontal directions of the rectangular display area. In the diamond pen tile arrangement, the number of green (G) is twice the number of red (R) and blue (B). In FIG. 9, the shape and size of each pixel of red (R), green (G), and blue (B) are shown by imitating the actual shape and size. The letters R, G, and B indicating colors are attached. Pixels having the same shape and size indicate pixels of the same color. That is, a small square pixel is a red (R) pixel, a large square pixel is a blue (B) pixel, and a round pixel is a green (G) pixel. is there.
In the present embodiment, a diamond pen tile array configured in a square array (same vertical and horizontal intervals) in the 45 degree direction will be described as an example. For example, a pixel array having a slightly different interval in the vertical and horizontal directions will be described. Elements may be used and are not limited to those applied to a square array of diamond pen tiles.

In such a pixel arrangement, attention is paid to the distance between the center positions of the respective pixels regardless of the difference in emission color (R, G, B). In the diamond pen tile arrangement, the pixels are arranged at equal intervals if the color difference is eliminated, and any pixel may be used as a reference. In the example of FIG. 9, the red (R) pixel at the bottom of the figure is used as a reference. And the following directions were prescribed | regulated by the distance (distance between centers) between pixel centers.

(First proximity arrangement direction DL1)
As shown in the first embodiment, the first adjacent arrangement direction DL1 is a direction in which the distance between the pixel centers is the closest from the appropriately selected reference pixel. The angle formed by the adjacent arrangement direction DL1 with the Z direction is 45 degrees.
(Second adjacent arrangement direction DL2)
The second proximity arrangement direction is a direction different from the first proximity arrangement direction DL1, and is the direction in which the center-to-center distance between the pixels is next to the first proximity arrangement direction DL1. Then, the angle formed by the second adjacent arrangement direction DL2 with the Z direction is 0 degree.

(Third adjacent arrangement direction DL3)
The third adjacent arrangement direction is a direction different from the first adjacent arrangement direction DL1 and the second adjacent arrangement direction DL2, and the direction in which the center-to-center distance between the pixels is next to the second adjacent arrangement direction DL2. Defined as DL3. In the present embodiment, the angle formed by the third adjacent arrangement direction DL3 and the Z direction is 18.4 degrees.

(Nth adjacent arrangement direction)
A direction different from the first adjacent arrangement direction to the Nth adjacent arrangement direction, where N is an integer of 3 or more, and the direction in which the center-to-center distance between the pixels is next to the Nth adjacent arrangement direction. It can be generalized and defined as the (N + 1) th adjacent arrangement direction. Even in the Nth adjacent arrangement direction, if the condition is satisfied, it can be used effectively in relation to a specific arrangement direction. However, in the following description, for ease of understanding, the description will be made using the first to ninth adjacent arrangement directions DL1 to DL9 shown in FIG.
In the present embodiment, the angles formed by the fourth to ninth adjacent arrangement directions DL4 to DL9 and the Z direction are 26.6 degrees, 11.3 degrees, 31.0 degrees, 8.1 degrees, and 33.7 degrees, respectively. 23.2 degrees.

Note that here, the nine directions from the first to ninth adjacent arrangement directions DL1 to DL9 will be described from the Z direction to the counterclockwise direction as shown in FIG. 11 for easy understanding. However, these directions also exist in a line-symmetrical direction with a straight line in the Z direction as a symmetry axis and in a line-symmetrical direction with these two directions as further a straight line in the X direction as a symmetry axis. Accordingly, nine directions from the first proximity arrangement direction to the ninth proximity arrangement direction can be set in four directions. The same applies to the Nth adjacent arrangement direction.

By arranging a specific arrangement direction (SZ direction) of the optical sheet 60 with an appropriate angular relationship with respect to the nine directions from the first to ninth adjacent arrangement directions DL1 to DL9, a clear image for the observer It was found that the non-image area can be suppressed from being visually recognized by the minute diffusion of the image light V.

FIG. 10 schematically illustrates how the optical sheet 60 diffuses the image light V when the optical sheet 60 is arranged with the specific arrangement direction (SZ direction) of the optical sheet 60 aligned with the third adjacent arrangement direction DL3. FIG.
As described above, the optical sheet 60 diffuses the video light V with respect to the arrangement direction (SZ direction) of the unit shapes 61a, but has almost no diffusing action with respect to the direction orthogonal to the arrangement direction (SX direction). . Accordingly, the light diffusing action of the optical sheet 60 has directivity in the direction in the sheet plane of the optical sheet 60 as in the diffusion ranges DR, DG, and DB shown in FIG. If the direction of the directivity, that is, the arrangement direction (SZ direction) of the unit shapes 61a becomes an appropriate direction as in the example of FIG. 10, it diffuses into a region corresponding to the non-video region as shown in FIG. It is possible to suppress the non-image area from being visually recognized by the observer due to the spread image light.

FIG. 11 schematically illustrates how the optical sheet 60 diffuses the image light V when the optical sheet 60 is arranged with the specific arrangement direction (SZ direction) of the optical sheet 60 aligned with the first adjacent arrangement direction DL1. FIG.
Compared to the previous case of FIG. 10, in the case of FIG. 11, since the range in which the video light V is diffused is not properly aligned, the area where the non-video area is visually recognized by the observer is large. The beneficial effect by providing the optical sheet 60 is not sufficiently obtained.

Thus, it is very important how the direction of the specific arrangement direction (SZ direction) of the optical sheets 60 is set. Accordingly, the angle δ indicating the specific arrangement direction (SZ direction) of the optical sheets 60 was gradually changed and arranged, and the appearance of the observed image was visually evaluated. The evaluation criteria for this visual evaluation are whether or not the non-image area can be suppressed from being visually recognized by the observer, and whether or not the observer can observe the image clearly.

FIG. 12 is a diagram illustrating a result of visual evaluation of the appearance of an observed image by gradually changing and arranging an angle δ indicating a specific arrangement direction (SZ direction) of the optical sheets 60. The circles in FIG. 12 indicate that the non-image area can be prevented from being visually recognized and a clear image can be observed. The Δ mark indicates that it is usable, although it is inferior to the ○ mark. The x mark indicates that the non-video region is not suppressed from being visually recognized, or the video is unclear.
From FIG. 12, it can be said that the optical sheet 60 is desirably disposed in the range of the angle δ from 8 degrees to 25 degrees, and more desirably disposed in the range of the angle δ from 8 degrees to 18 degrees. However, this numerical range is based on the premise that the image source 11 having a diamond pen tile arrangement is used. From the viewpoint of suppressing the non-image area from being visually recognized, it is desirable to define a specific arrangement direction (SZ direction) of the optical sheet 60 from the arrangement of the pixels.

That is, the orientation of the optical sheet 60 determines whether or not the effectiveness of the optical sheet 60 is exhibited in relation to the pixel arrangement. Therefore, based on the result of FIG. 12, how is the specific arrangement direction (SZ direction) of the optical sheet 60 with respect to the nine directions from the first adjacent arrangement direction to the ninth adjacent arrangement direction described above? Specifically, it should be specified as follows.

The optical sheet 60 is preferably arranged so that the specific arrangement direction thereof has an angle of 2 degrees or less with respect to any of the third to ninth adjacent arrangement directions DL3 to DL9.
By arranging the optical sheet 60 in this way, a clear image can be displayed to the observer, and the non-image area of the image source 11 can be prevented from being visually recognized due to the slight diffusion of the image light V. Can do.

In addition, it is desirable that the optical sheet 60 be arranged such that the specific arrangement direction has an angle of 5 degrees or more with respect to the first adjacent arrangement direction DL1 and the second adjacent arrangement direction DL2.
More desirably, the optical sheet 60 is arranged such that the specific arrangement direction has an angle of 10 degrees or more with respect to the first adjacent arrangement direction DL1, and 5 with respect to the second adjacent arrangement direction DL2. It is good to arrange with an angle of more than degree.
If the optical sheet 60 is arranged in this way, it is possible to avoid an inappropriate arrangement as shown in FIG. 11, a clear image can be displayed to the observer, and a non-image area can be displayed. It can suppress that it is visually recognized.

The optical sheet 60 is a straight line drawn in a direction along the specific arrangement direction, and a virtual line is drawn into a region including pixels and a region not including pixels by drawing a straight line passing through the outermost diameter portion of the pixels. In particular, when the video source 11 is divided, it is desirable that the specific arrangement direction is provided so that the area ratio of the region including the pixels is 80% or more, more preferably 100%. The area ratio of the region including the pixel will be described with reference to FIG. FIG. 11 shows a case where the optical sheet 60 is arranged with the specific arrangement direction (SZ direction) of the optical sheet 60 aligned with the first adjacent arrangement direction DL1. In this case, it can be virtually divided into the regions PB1, PB2, PB3, and PB4 shown in FIG. 11 by a straight line drawn in a direction along a specific arrangement direction. In the figure, portions other than the regions indicated as regions PB1, PB2, PB3, and PB4 are repetitions of regions PB1, PB2, PB3, and PB4. The ratio of the widths of these regions is PB1: PB2: PB3: PB4 = 15: 15: 13: 15. Therefore, in the example of FIG. 11, the area ratio of the region including the pixels = (13 + 15) / (15 + 13 + 15 + 15) = 48%.
When the area ratio of the region including the pixel is similarly obtained in the other direction, it is 64% in the second adjacent arrangement direction DL2, and 100% in the third to seventh adjacent arrangement directions DL3 to DL7.
In this way, if the optical sheet 60 is arranged so that the area ratio of the region including the pixels is 80% or more or 100%, a clear image can be displayed to the observer and a non-image can be displayed. It can suppress that an area | region is visually recognized.

In addition, it is desirable that the optical sheet 60 is arranged including pixels of different colors in the direction along the specific arrangement direction. This is because, if only the pixels of the same color are used, the same color lines are diffused and the appearance is deteriorated.

Furthermore, among the center-to-center distances between the pixels in any of the third to ninth adjacent arrangement directions DL3 to DL9, the center-to-center distance in the direction corresponding to the specific arrangement direction is the first adjacent arrangement direction. It is desirable that it is within 7 times the distance between the centers of the pixels. In FIG. 9, the distance between the pixel centers is also indicated by a symbol. The example in FIG. 9 will be described as follows.
First adjacent arrangement direction DL1: CD1 / CD1 = 1.0
Second adjacent arrangement direction DL2: CD2 / CD1 = 1.4
Third adjacent arrangement direction DL3: CD3 / CD1 = 2.2
Fourth adjacent arrangement direction DL4: CD4 / CD1 = 3.2
Fifth adjacent arrangement direction DL5: CD5 / CD1 = 3.6
Sixth adjacent arrangement direction DL6: CD6 / CD1 = 4.1
Seventh adjacent arrangement direction DL7: CD7 / CD1 = 5.0
Eighth adjacent arrangement direction DL8: CD8 / CD1 = 5.1
Ninth adjacent arrangement direction DL9: CD9 / CD1 = 5.4
As described above, in this embodiment, any direction satisfies the above condition of 7 times or less.
When the center-to-center distance in the direction corresponding to the specific array direction exceeds seven times the center-to-pixel distance in the first adjacent array direction, the diffusion action of the optical sheet 60 becomes insufficient, and This is because a non-video area between the pixels may be visually recognized, and on the other hand, if the diffusion action is enhanced, a clear video cannot be obtained.

The light emitted from one pixel provided in the video source 11 has its light range (hereinafter referred to as a light emitting area) expanded mainly by the diffusion action of the optical sheet 60. As described above, since the direction in which the optical sheet 60 diffuses light has directivity, the direction in which the light emitting area expands due to the diffusion action of the optical sheet 60 also has directivity.
FIG. 13 is a diagram illustrating a light emitting area of one pixel according to the fourth embodiment. FIG. 13A is an observation image obtained by enlarging an image displayed by the image source 11 with a digital microscope or the like without using the lens 12 and the optical sheet 60, and shows a state of light emitted from one pixel. . The diagrams shown in FIGS. 13B and 13C are observation images obtained by enlarging an image displayed in a state where the image source 11 and the optical sheet 60 are arranged in combination without using the lens 12, and one pixel. The state of the light emitted by is shown.

When the light emitted from the pixel does not pass through the optical sheet 60 or the like, as shown in FIG. 13A, the light emitting area EA0 is observed as a shape close to the shape of the light emitting portion of the pixel (for example, a circular shape). Is done. Then, by receiving the diffusing action of the optical sheet 60, the light emitted from the pixels is spread most greatly in a specific arrangement direction (SZ direction, arrangement direction of the unit shapes 61a), as shown in FIG. Further, the light emitting area EA is observed as a shape that is most widened in one direction along a specific arrangement direction. The direction in which the light emitting area EA is expanded is equal to the direction in which the diffusion is the largest.

In addition, as the distance between the optical sheet 60 (interface 601) and the pixel (display layer) of the image source 11 is shorter, the arrangement pitch P1 of the unit shapes 61a of the optical sheet 60 is preferably smaller from the viewpoint of obtaining an appropriate diffusion action. Become. Therefore, when the optical sheet 60 is disposed close to the pixels, such as being stacked on the display surface 11a of the video source 11, compared with the case where the optical sheet 60 is disposed away from the video source 11, the optical sheet 60 The ratio of the amount of emitted light that is diffused and emitted by diffraction in the unit shape 61a is large.
In this case, as shown in FIG. 13 (c), the light emitting area EA is in a state where it spreads most in one direction along a specific arrangement direction (SZ direction) and has a large amount of light generated by the influence of diffraction. (Bright areas) are observed in multiple grains.

FIG. 14 is a diagram illustrating the width of the light emitting area according to the fourth embodiment. Each graph shown in FIG. 14 shows the distribution of the light quantity in the direction (SZ direction) in which the light emitting area EA is greatly expanded, the vertical axis shows the light quantity, and the horizontal axis shows the position in the SZ direction.
The graph shown in FIG. 14A shows an example of the light amount distribution of one light emitting area EA0 in the observation image obtained by enlarging the image displayed by the image source 11 without using the lens 12 and the optical sheet 60. In each graph shown in FIGS. 14B and 14C, one light emitting area in an observation image obtained by enlarging an image displayed in a state where the image source 11 and the optical sheet 60 are combined and arranged without using the lens 12. FIG. An example of the distribution of the light quantity of EA is shown. The graph shown in FIG. 14B is an example in the case where the ratio of the diffusing action due to refraction at the interface of the unit shape 61a is high in the light emitted from the optical sheet 60, and the graph shown in FIG. This is an example of a case where the ratio of the diffusion action due to diffraction by the unit shape 61a is high in the light emitted from the optical sheet 60.

As shown in FIGS. 14B and 14C, the spreading width W of the light emitting area EA of one pixel is defined in the same manner as the spreading width shown in the first embodiment. The spread width W of the present embodiment corresponds to the maximum spread width SW shown in the first embodiment. The spread width W is 0.5 times or more and 5 times or less of the closest distance S (distance between the centers of the pixels in the first adjacent arrangement direction DL1) of the pixels as in the first embodiment. preferable.

It should be noted that, in an image displayed in a state where the image source 11 and the optical sheet 60 are arranged in combination, the maximum value of the light amount in the light emitting area EA, a value that is 1/5 of the maximum value, the positions of the two points t1 and t2, The distance between the two points t1 and t2 can be calculated by a method similar to the calculation method described in the first embodiment.
Further, the distance between the centers of the pixels in the first adjacent arrangement direction DL1 (that is, the closest distance S of the pixels) in the image displayed in a state where the image source 11 and the optical sheet 60 are disposed in combination is also determined. It can be calculated by the calculation method shown in the first embodiment.

Further, the spread width W satisfies the above range, and further, in the image displayed in a state where the image source 11 and the optical sheet 60 are arranged in combination, the direction in which the spread of the light emitting area EA is the largest (in the optical sheet 20). It is preferable to be equal to or less than the distance between the centers of pixels arranged closest to each other in a specific arrangement direction (SZ direction) (pixel closest distance S).
When the spread width W is larger than the distance between the centers of the pixels arranged closest to each other in the direction in which the spread of the light emitting area EA is the largest (the specific arrangement direction of the optical sheet 60, the SZ direction), The light emitting areas of adjacent pixels (the range in which the light emitted from the adjacent pixels spreads) overlap each other, which may cause blurring of images and the like, which is not preferable.

Further, the direction in which the light emitting area EA expands most is equal to the specific arrangement direction (SZ direction) of the optical sheet 60, and is 5 with respect to the first adjacent arrangement direction DL1 and the second adjacent arrangement direction DL2 as described above. It is desirable that the optical sheet 60 is disposed so as to form an angle of more than degrees.
If the optical sheet 60 is arranged in this way, it is possible to avoid an inappropriate arrangement in which the non-image area as shown in FIG. 11 is viewed in a streak shape, and a clear image is displayed to the observer. And it is possible to suppress the non-video region from being visually recognized.

Further, the direction in which the light emitting area EA expands most is equal to the specific arrangement direction (SZ direction) of the optical sheet 60, and as described above, any one of the third to ninth adjacent arrangement directions DL3 to DL9. It is desirable that they are arranged with an angle of 2 degrees or less.
By arranging the optical sheet 60 in this way, it is possible to display a clear image to the observer and to suppress the non-image area from being visually recognized.

As in this embodiment, in the display device 1 including the image source 11 in which the pixel arrangement is a diamond pen tile arrangement, the angle δ indicating a specific arrangement direction (the arrangement direction of the unit shapes 61a, the SZ direction) is changed. When the optical sheet 60 is arranged and the appearance of the observed image is visually evaluated, it is preferable to arrange the optical sheet 60 with the angle δ in the range of 8 degrees to 25 degrees as shown in FIG. It is further desirable that the angle δ is arranged in the range of 8 degrees to 18 degrees.

Then, the display device 1 arranges the optical sheet 60 so that the angle δ satisfies the above-described range, and further displays a light emitting area in an image displayed in a state where the image source 11 and the optical sheet 60 are combined. A distance between the centers of the pixels closest to each other in the spread width W of EA (that is, the distance between the centers of the pixels in the first adjacent arrangement direction DL1 and the closest distance S of the pixels) is 0. By setting it to 5 times or more and 5 times or less, it is possible to suppress the non-video region from being viewed and the video region from being viewed independently, and to display a good image.
Furthermore, in the above image, the spread width W is equal to or less than the distance between the centers of the pixels arranged in the direction in which the spread of the light emitting area EA is the largest (specific arrangement direction of the optical sheet 60, SZ direction). Thus, the display device 1 can further improve the above-described effect and display a good image with less blur.

Here, as an example, the direction (SZ direction) in which the spread width W due to the diffusion action of the optical sheet 60 satisfies the above-described preferable range and the light emitting area EA is expanded most by the optical sheet 60 is the fifth adjacent arrangement direction DL5. When the display device 1 matched with the above is prepared and observed at the observation position (the positions of the eyes E1 and E2 of the observer when the display device 1 is used and the focal point of the image light V by the lens 12), It was possible to suppress the viewing of the video area, suppress the viewing of the video area independently, and view a good image.
Further, in this display device 1, when the spread width W due to the diffusing action of the optical sheet 60 is less than the preferred range or larger than the preferred range and is observed at the observation position, the non-image area is visually recognized and the image is displayed. A good image could not be visually recognized because the area was observed independently, or the blur of the image was increased and the sharpness was greatly reduced.

Next, the spreading width W satisfies the preferred range as described above, and the direction in which light is most spread by the third adjacent arrangement direction DL3 and the seventh adjacent arrangement direction DL7 and the optical sheet 60 (the arrangement direction of unit shapes 21a (SZ direction). )) And the display device 1 were prepared, and when an image was visually recognized at the observation position, a good image was also visually recognized.
Further, in these display devices 1, those in which the spread width W due to the diffusion action of the optical sheet 60 is less than the preferred range and those that are larger than the preferred range are prepared, and the image displayed at the observation position is visually confirmed as described above. However, a non-video area is visually recognized, and the video area is observed independently, or the blurred image is greatly increased and the sharpness is greatly reduced. It was.

(Deformation)
Without being limited to the embodiments described above, various modifications and changes are possible, and these are also within the scope of the present invention.
(1) In the first and third embodiments, the refractive indexes of the unit shapes 21a and 61a of the first optical layers 21 and 61 are higher than the refractive indexes of the second optical layers 22 and 62. In the second embodiment, Although the example in which the refractive index of the unit shape 41a of the first optical layer 41 and the refractive index of the third optical layer 43 is higher than the refractive index of the second optical layer 42 has been shown, the present invention is not limited to this. In the third embodiment, the refractive index of the first optical layers 21 and 61 is lower than the refractive index of the second optical layers 22 and 62, or in the second embodiment, the first optical layer 41 and the third optical layer. The refractive index 43 may be lower than the refractive index of the second optical layer 42.
Moreover, although the 1st optical layers 21 and 41 showed the form in which several unit shapes were shape | molded on the single side | surface of a base material layer, it is good also as a form not only this but a single layer.

(2) In the second embodiment, the optical sheet 40 has a configuration in which the three optical layers of the first optical layer 41, the second optical layer 42, and the third optical layer 43 are sequentially laminated. However, the present invention is not limited to this. It is good also as a form provided with four or more optical layers according to the optical performance etc. which are not desired.
Moreover, in 2nd Embodiment, the optical shape surface should just be one or more, for example, is good also as the optical sheet 40 provided with three optical shape surfaces.

(3) In each embodiment, although the optical sheet 20, 40, 60 showed the form hold | maintained at the holding | maintenance part 32, it is not restricted to this, For example, opening 311A of the holding | maintenance part 31 holding the image source 11 is provided. 311B may be bonded to the observer side or the like so as to close these openings, or the openings 331A and 331B of the holding unit 33 that holds the lens 12 may be closed on the image source side. It is good also as a form stuck.
Further, in each embodiment, the optical sheets 20, 40, 60 may be disposed closer to the viewer than the lens 12.

(4) In each embodiment, although the optical sheet 20, 40, 60 showed the example provided independently corresponding to each of the left and right eyes, it is not restricted to this.
For example, the optical sheet 20 may have a shape in which regions corresponding to the left and right eyes E1 and E2 are connected to each other, or a rectangular shape that is large enough to cover the regions of the lenses 12A and 12B. With such a shape, it becomes easy to arrange the SX direction and the SZ direction of the optical sheet 20 at a predetermined angle δ with respect to the X direction and the Z direction. In this case, an index indicating the direction of the optical sheet 20 may be provided in order to prevent mistakes during assembly, or the shape of the optical sheet may be asymmetric. The same applies to the optical sheet 40 of the second embodiment and the optical sheet 60 of the third and fourth embodiments.
In each embodiment, the display device 1 may include two image sources corresponding to the lenses 12A and 12B and the eyes E1 and E2 of the observer.

(5) In each embodiment, the video source 11 may be fixed to the display device 1 in advance and not removable.

(6) In the third embodiment and the fourth embodiment, the optical sheet 60 has been described with an example in which the second optical layer 62 is laminated on the first optical layer 61 provided with the unit shape 61a. . For example, the second optical layer 62 may be omitted.

(7) In 4th Embodiment, the optical sheet 60 gave and demonstrated the example provided with only the unit shape of the lenticular lens shape extended in one direction. For example, two different unit shapes intersecting in the arrangement direction may be provided in the same optical sheet, or may be used separately.

In addition, although this embodiment and modification can also be used in combination suitably, detailed description is abbreviate | omitted. Further, the present invention is not limited to the embodiments described above.

DESCRIPTION OF SYMBOLS 1 Display apparatus 11 Image source 11a Display surface 12 Lens 12a Antireflection layer 20,40,60 Optical sheet 21,41,61 1st optical layer 21a, 41a, 61a Unit shape 22,42,62 2nd optical layer 22a, 42a Unit shape 43 Third optical layer 201, 202, 401, 402, 601 Optical shape surface

Claims (16)

1. An image source in which a plurality of pixels are arranged to emit image light; and
   A lens that magnifies and emits the image light to the viewer side;
   An optical sheet disposed between the image source and the lens or on the viewer side of the lens;
   With
   The optical sheet is provided with at least one optical shape surface in which convex or concave unit shapes extending along the sheet surface are arranged in a direction perpendicular to the extending direction inside or on the surface thereof,
   A display device.
2. The display device according to claim 1,
   In an image displayed in a state where the image source and the optical sheet are arranged, a range in which light from one of the pixels spreads by a diffusing action of the optical sheet is a light emitting area,
   In the light emitting area, the distance between the two most distant points that is 1/5 of the maximum value of the light quantity in the arrangement direction of the unit shapes is defined as the spread width in the arrangement direction,
   When the maximum spread width is set to the maximum value among the one or more spread widths,
   The maximum spread width is not less than 0.5 times and not more than 5 times the closest distance of a pixel, which is a distance between the centers of the pixels arranged closest to each other in the image;
   A display device.
3. The display device according to claim 1,
   In an image displayed in a state where the image source and the optical sheet are arranged, a range in which light from one of the pixels spreads by a diffusing action of the optical sheet is a light emitting area,
   In the light emitting area, the distance between the two most distant points that is 1/5 of the maximum value of the light quantity in the arrangement direction of the unit shapes is defined as the spread width in the arrangement direction,
   The largest spread width among the one or more spread widths is defined as the maximum spread width,
   The direction in which the center-to-center distance between the pixel and the pixel is the closest is the first proximity array direction,
   When the second proximity arrangement direction is a direction different from the first proximity arrangement direction, and the direction in which the center distance between the pixel and the pixel is next to the first proximity arrangement direction is
   Among the arrangement directions of one or more of the unit shapes, the arrangement direction in which the spread width becomes the maximum spread width forms an angle of 5 degrees or more with respect to the first adjacent arrangement direction and the second adjacent arrangement direction. thing,
   A display device.
4. The display device according to claim 1,
   The optical sheet is
   Two or more optical layers are laminated,
   A first optical shape surface which is an interface between the adjacent optical layers and has a plurality of convex or concave first unit shapes;
   A second optical shape surface formed by a plurality of convex or concave second unit shapes at another interface between the adjacent optical layers or an interface between the optical layer and air;
   With
   The first unit shape extends in a first direction in a sheet surface orthogonal to the thickness direction of the optical sheet, and is arranged in a second direction orthogonal to the first direction in the sheet surface,
   The second unit shape extends in a third direction in the sheet surface orthogonal to the thickness direction of the optical sheet, and is arranged in a fourth direction orthogonal to the third direction in the sheet surface,
   The first direction and the third direction intersect when viewed from the thickness direction of the optical sheet;
   A display device.
5. The display device according to claim 4,
   The optical sheet has three or more optical layers,
   A plurality of the first unit shape and the second unit shape are respectively provided at different interfaces between the adjacent optical layers;
   A display device.
6. The display device according to claim 1,
   The optical sheet is flat on both sides,
   A display device.
7. The display device according to claim 4,
   The optical sheet is formed by laminating two optical layers.
   A plurality of the first unit shapes are provided at the interface between the two optical layers,
   A plurality of the second unit shapes are provided at the interface between one of the two optical layers and the air;
   A display device.
8. The display device according to claim 1,
   The light diffusion action of the optical sheet has a direction in which the diffusion is the largest in the direction within the sheet surface of the optical sheet,
   The unit shapes are arranged in a specific arrangement direction at least in the sheet plane perpendicular to the thickness direction of the optical sheet,
   The optical sheet diffuses light in the arrangement direction of the unit shapes,
   The unit shape extends in a first direction in a sheet plane orthogonal to the thickness direction of the optical sheet, and a second direction orthogonal to the first direction in the sheet plane is the specific arrangement direction. Are arranged as
   The direction in which the light diffusion action of the optical sheet is the largest is the specific arrangement direction,
   A display device.
9. The display device according to claim 8, wherein
   The video source is configured by arranging a plurality of pixels side by side,
   The direction in which the distance between the centers of the pixels is the closest is defined as the first proximity array direction,
   A direction different from the first adjacent arrangement direction, and a direction in which a center-to-center distance between pixels is next to the first adjacent arrangement direction is defined as a second adjacent arrangement direction;
   The third proximity arrangement direction is a direction different from the first proximity arrangement direction and the second proximity arrangement direction, and a direction in which the center-to-center distance between the pixels is next to the second proximity arrangement direction. As stipulated as
   The fourth proximity arrangement direction is a direction that is different from the first proximity arrangement direction to the third proximity arrangement direction, and in which the center-to-center distance between the pixels is next to the third proximity arrangement direction. As stipulated as
   An integer greater than or equal to 3 is assumed to be N. Hereinafter, the distance from the first adjacent arrangement direction to the Nth adjacent arrangement direction is different, and the distance between the centers of the pixels is next to the Nth adjacent arrangement direction. Is defined as the (N + 1) th adjacent arrangement direction,
   The direction in which the diffusion is greatest is arranged with an angle of 2 degrees or less with respect to the Nth adjacent arrangement direction,
   Of the center-to-center distances between the pixels in the Nth adjacent arrangement direction, the center-to-center distance in the direction corresponding to the direction in which the diffusion is largest is the center-to-center distance between the pixels in the first adjacent arrangement direction. Within 7 times,
   A display device.
10. The display device according to claim 9, wherein
    The direction in which the diffusion is the largest is arranged with an angle of 5 degrees or more with respect to the first adjacent arrangement direction and the second adjacent arrangement direction,
    A display device.
11. The display device according to claim 9, wherein
    The direction in which the diffusion is greatest is arranged with an angle of 10 degrees or more with respect to the first adjacent arrangement direction, and is arranged with an angle of 5 degrees or more with respect to the second adjacent arrangement direction. is being done,
    A display device.
12. The display device according to claim 9, wherein
    The video source is configured by arranging the pixels of a plurality of colors side by side,
    In a direction along the direction in which the diffusion is the largest, pixels of different colors are included and arranged,
    A display device.
13. The display device according to claim 1,
    When the pitch at which the unit shapes are arranged is P, and the distance between the optical shape surface on which the unit shapes are formed and the display layer of the video source is L,
    0.005 ≦ P / L ≦ 0.05
    Meeting,
    A display device.
14. The display device according to claim 2,
    The spread width is equal to or less than a center-to-center distance between pixels arranged along a direction in which the spread of the light emitting area is the largest in the video;
    A display device.
15. The display device according to claim 8, wherein
    The pixel array of the image source is a diamond pen tile array,
    A display device.
16. The display device according to claim 1,
    There is no air layer in a region between the display surface of the image source and the surface on the viewer side of the optical sheet, at least in the region through which the light reaching the viewer is transmitted. ,
    A display device.

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