HK1154080A - Spectacles-type image display device - Google Patents

Description

Glasses type image display device

Technical Field

The present invention relates to a glasses-type image display device.

Background

Conventionally, as a glasses-type image display device, for example, a device including an image output unit held on a temple (temple) side of glasses and an eyepiece optical unit held adjacent to a lens of the glasses is suggested. Such an eyeglass-type image display device is configured such that image light of an electronic image to be displayed, which is output from an image output unit, is incident on an eyeball of a viewer through an eyepiece optical unit, so that the viewer can see the image. In such a glasses-type image display device, the electronic image and the background image transmitted through the glasses lens are generally superimposed and displayed on the eyeball (this is called "see-through display").

As such a technique, an apparatus having a concave mirror obstructing a front view and a plurality of projection mirrors (see, for example, JP5303056(a)) and an apparatus provided with hologram elements on respective eyeglass lenses (see, for example, JP2006209144(a)) are known. In addition, as such a glasses type image display device, a device configured to hold an image output unit by a glasses frame or the like to allow image light to enter from outside of the glasses lenses (see, for example, JP2001522064(T)) and a device configured to configure an optical path to allow image light to enter each glasses lens (see, for example, JP200511306(T)) are known.

Disclosure of Invention

However, according to the technique described in JP5303056(a), in order to correct aberrations caused by using a large concave mirror, a complicated projection optical system is used. In addition, there are problems such as blocking due to the size of the concave mirror and the need to increase the see-through function. In addition, according to the technique described in JP2006209144(a), since the wavelength selectivity of the hologram optical element is strong, a high-cost method (for example, using a light source such as a laser beam or using only a part of the wavelength with a high-performance filter) is required. In addition, with the hologram optical element, it is difficult to increase the adjustment function according to the diopter (curvature) of each viewer.

In view of the above, an object of the present invention is to provide a glasses-type image display device which enables a viewer to see an external view and an electronic image simultaneously without blocking his/her external view, and which can be small, light-weight, and low-cost.

In order to solve the above problems, a glasses type image display device according to the present invention includes: an image output unit having a display element that displays an image and is provided on a frame of the glasses; and a reflection unit disposed adjacent to the at least one eyeglass lens and configured to reflect the image light output from the image output unit toward an eyeball of the viewer when the viewer wears the eyeglasses so that the viewer can see a virtual image of the image, wherein the reflection unit is a reflection member having positive refractive power, and an effective luminous flux output from the image output unit and reaching the eyeball of the viewer is configured to: so that, for an optical axis section (a section including the optical axis) parallel to the incident surface of the optical axis of the reflection unit, the width of the effective luminous flux perpendicular to the optical axis is minimized at the reflection unit. That is, in the optical system of the glasses-type image display device of the present invention, the reflecting member substantially functions as an aperture stop. In other words, the exit pupil position for an optical axis section parallel to the entrance face may be the reflective member.

Preferably, the minimum width of a cross-section perpendicular to the optical axis is less than 4mm, the 4mm being the average pupil diameter of the person.

In addition, it is preferable that, for the reflection surface of the reflection member, a width in a direction parallel to the incident surface is smaller than a width in a direction perpendicular to the incident surface.

In addition, preferably, the display element is rectangular in shape, and is disposed such that a longitudinal direction of the rectangular shape corresponds to a minimum width direction of the reflection surface of the reflection member. In other words, even if the reflective member is longitudinally long, the display element may be laterally long.

In addition, the reflection surface of the reflection member is represented by Rx > Ry, where the radius of curvature perpendicular to the incidence surface is Ry and the radius of curvature parallel to the incidence surface is Rx. In other words, the reflecting member is a so-called toroidal mirror (toroidal mirror).

Preferably, the reflecting surface of the reflecting member is a free-form surface (free-form surface). In other words, the reflecting member is a so-called free surface mirror.

In addition, for the effective light flux that is output from the image output unit and reaches the eyeball of the viewer, the pupil position in the lateral direction, which is the exit pupil position for an optical axis section parallel to the incident surface of the reflection member, is located near the reflection member, and the pupil position in the longitudinal direction, which is the exit pupil position for an optical axis section perpendicular to the incident surface of the reflection member, is located closer to the pupil of the eyeball of the viewer than the pupil position in the lateral direction. In other words, the reflecting member functions as an aperture stop for an optical axis section parallel to the incident surface, but does not function as an aperture stop for an optical axis section perpendicular to the incident surface.

Further, preferably, the reflective member is embedded in the eyeglass lens.

In addition, preferably, the image output unit is rotatably held around a reflection surface of the reflection unit.

Further, preferably, the reflection unit is rotatably held with its rotation axis located in the reflection surface of the reflection member.

In addition, it is preferable that a deflection prism is provided between the display element and the reflection unit.

In addition, it is preferable that the display element is disposed to face a forward direction of a viewer, and light output from the display element is incident on the deflection prism, deflected by 50 ° to 70 °, and emitted toward the reflection unit.

In addition, it is preferable that the deflection prism is held by a temple (endpiece) of the glasses, the display element is held by a temple of the glasses, and the display element is movable and adjustable in a direction perpendicular to the display surface.

Further, preferably, the deflection prism is held by a temple of the glasses, the display element is held by a temple of the glasses, and the display element is movable and adjustable in a direction parallel to the display surface.

In addition, it is preferable that a longitudinal aberration correction lens for correcting longitudinal aberration caused by decentering of the reflection unit is provided between the display element and the reflection unit.

In addition, it is preferable that the surface of the longitudinal aberration correction lens is in the shape of a free surface.

In addition, preferably, the longitudinal aberration correction lens is integrated in the deflection prism.

In addition, preferably, the display element is an organic EL.

In addition, it is preferable that the display element is disposed at a position where a projection section with respect to the viewer's front direction does not cover the pupil of the viewer.

According to the present invention, it is possible to provide a glasses-type image display device which enables a viewer to see an external image and an electronic image simultaneously without obstructing an external view, and which can realize features of small volume, light weight, and low cost.

Drawings

Fig. 1 is a partial block diagram schematically showing main components of a glasses-type image display device according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram showing an example of a reflection unit for carrying out the present invention;

fig. 3 is a front view of the right eye side of a viewer when the viewer wears the glasses-type image display device in fig. 1;

fig. 4 is a front view showing a width in a short side direction of a rectangular reflection unit according to a first embodiment of the present invention;

FIG. 5 is a basic block diagram illustrating selected optical elements according to a first embodiment of the present invention;

fig. 6 is a light ray diagram of an optical axis section in the lateral direction and an optical axis section in the longitudinal direction of the optical system according to the first embodiment of the present invention;

fig. 7 is a schematic view showing a configuration and a use state of a glasses-type image display device according to a second embodiment of the present invention;

FIG. 8 is a basic block diagram illustrating selected optical elements according to a second embodiment of the present invention;

fig. 9 is a schematic diagram illustrating an example of interpupillary accommodation according to a second embodiment of the present invention;

fig. 10 is a schematic diagram illustrating an example of interpupillary accommodation according to a second embodiment of the present invention;

fig. 11 is a schematic view schematically showing a glasses-type image display device according to a third embodiment of the present invention;

fig. 12 is a schematic view schematically showing a glasses-type image display device according to a fourth embodiment of the present invention;

FIG. 13 is a ray diagram of an optical system according to a fourth embodiment of the present invention;

fig. 14 is a light ray diagram for comparison to show the effect of the fourth embodiment of the present invention;

fig. 15 is a light ray diagram showing an effect of reducing decentering aberration due to the longitudinally long reflecting member of the present invention;

FIG. 16 is an aberration diagram when the reflecting surface of the free surface mirror is circular;

FIG. 17 is an aberration diagram when the reflecting surface of the free surface mirror is a longitudinally long rectangle;

FIG. 18 is an aberration diagram when the reflecting surface of the free surface mirror is a laterally long rectangle;

fig. 19 is a schematic view schematically showing a glasses-type image display device according to a fifth embodiment of the present invention;

fig. 20 is a schematic view schematically showing a glasses-type image display device according to a sixth embodiment of the present invention;

fig. 21 is a schematic view schematically showing a glasses-type image display device according to a seventh embodiment of the present invention; and

fig. 22 is a schematic view schematically showing a glasses-type image display device according to an eighth embodiment of the present invention.

Detailed Description

Embodiments of the present invention are described below with reference to the drawings.

(first embodiment)

Fig. 1 is a partial block diagram schematically showing main components of a glasses-type image display device according to a first embodiment of the present invention. In the schematic diagram, eyeballs 2 of the right eye of the viewer when he/she wears the glasses-type image display device 1 are also shown. As shown in this schematic diagram, the eyeglass type image display device 1 of the present embodiment has an image output unit 4 provided on a frame unit 3 of eyeglasses and a reflection unit 5 that reflects image light output from the image output unit 4 toward eyeballs 2 of a viewer.

The image output unit 4 has therein a display element (not shown in fig. 1) that displays a two-dimensional image and emits image light. As the display element, a general-purpose display element such as a liquid crystal display element or an organic EL element can be used. These common display elements are known as low cost devices. In particular, when an organic EL element is used as a display element, a backlight is not required, and thus a small-sized and lightweight device requiring low power can be realized.

The reflection unit 5 is a reflection member having a positive refractive power disposed adjacent to the eyeglass lenses, and is disposed to reflect the image light output by the image output unit 4 toward the eyeball 2 of the viewer when the viewer wears the eyeglasses to allow the viewer to see a virtual image of the two-dimensional image. As shown in fig. 2, (a) a front surface mirror, (b) a rear surface mirror, (c) a mirror embedded in an eyeglass lens, and (d) a total reflection prism, etc. may be used as the reflection unit 5. Mirrors whose front and rear surfaces are treated with typical mirror coatings (e.g., metal deposits or dielectric multilayer films), respectively, may be used as the front surface mirror and the rear surface mirror. When a mirror embedded in the eyeglass lens is used, the tilt angle can be reduced by refraction between the eyeglass lens and the air. When using a total reflection prism, refraction can be achieved without a mirror coating.

In fig. 1, the spectacle frame 3 is fixed to the spectacle lens 6 (or the frame of the spectacle lens 6) and comprises studs 7 at the two ends of the front face of the spectacle and temples 9 foldably connected by the studs 7 and hinges 8. The image output unit 4 according to the present embodiment is held by the temple 9 through the hinge 8, and is folded together with the temple 9 when the eyeglass frame 3 is folded.

In the above-described structure, the image light output from the image output unit 4, reflected by the reflection unit 5, and reaching the eyeballs 2 of the viewer transmits the space surrounded by the eyeglass lenses 6, the eyeglass frame 3 (and the face of the viewer). This configuration can reduce obstacles blocking the view of the viewer as much as possible, and does not cause any component to be disturbed (for example, by the image output unit 4) when the eyeglass frame 3 is folded.

Fig. 3 is a front view of the right eye side of a viewer when the viewer wears the glasses-type image display device in fig. 1. As shown in fig. 3, in the glasses-type image display device according to the present embodiment, the reflection unit 5 is disposed at a position such that the reflection unit 5 does not cover the pupil 10 of the viewer with respect to the projection cross section with respect to the front direction of the viewer. In the present embodiment, the reflection unit 5 is provided at this position, so that the field of view of the viewer can be sufficiently secured in a normal situation (when the viewer pays more attention to information around him/her than information from the glasses-type image display device). Therefore, even when the viewer wears the glasses-type image display device according to the present embodiment, the viewer can safely move around.

In addition, as shown in fig. 3, in the glasses-type image display device according to the present embodiment, the reflection unit 5 is in the shape of a vertically long rectangle. On the other hand, the image output unit 4 and the display element provided therein are in the shape of a horizontally long rectangle. In other words, the apparatus is configured such that the longitudinal direction of the display element 13 corresponds to the minimum width direction of the reflection unit 5, whereby image light can be guided to a narrow space between the glasses and the face even if the image is displayed long in the lateral direction. In addition, in the glasses-type image display device according to the present embodiment, since the reflection unit 5 is in the shape of a longitudinally long rectangle, there is a large tolerance in longitudinal slippage in a state where the device is mounted. In addition, if the tolerance of the vertical shift caused by the vertically long reflecting unit is used as the image display area, the configuration according to the present embodiment can be used for a vertically long display screen (i.e., a vertically long display element).

In addition, the reflection unit 5 of the longitudinally long rectangular shape according to the present embodiment has an advantage in optical performance. The reflection member of the reflection unit 5 has a positive refractive power, and as shown in fig. 1, the image light output from the graphic output unit 4 is eccentrically incident on the reflection unit 5 and is reflected toward the eye pupil 10. In other words, with the reflection unit 5 according to the present embodiment, an eccentric aberration parallel to the incident surface is generated. However, since the reflection unit 5 according to the present embodiment is a longitudinally long rectangular shape (the width in the direction parallel to the incident surface is small), the eccentric aberration generated at the reflection unit 5 can be reduced. As for the correction of the aberration, a detailed explanation will be given with reference to the aberration diagram in the fourth embodiment.

Fig. 4 is a schematic diagram showing a width along a short side direction of the rectangular reflection unit according to the present embodiment. As described above, in the present embodiment, the image light output from the image output unit 4 is reflected by the reflection unit 5 and guided to the eye pupil 10 of the eyeball 2. Therefore, the reflection unit 5 is disposed obliquely with respect to the line of sight of the eyeball 2 (or the optical axis of the image light output from the image output unit 4). In other words, the size of the reflection unit 5 is different from its actual size with respect to the field of view of the viewer. In the present embodiment, the apparatus is configured such that the width of a cross section (a projection cross section along the line-of-sight direction) of the reflection unit 5 perpendicular to the optical axis is 4mm or less. The value of 4mm is based on the average diameter of the pupil of a person, and when the width of the cross section perpendicular to the optical axis of the reflection unit 5 is less than 4mm, a phenomenon called pupil division perspective is realized by which background light that is not blocked by the reflection unit 5 passes through the pupil 10 of the eye and forms an image on the retina, so that image light output from the image output unit 4 is superimposed on the background light.

Fig. 5 is a basic block diagram showing an optical element selected according to the present embodiment for explaining the optical system according to the present embodiment in more detail. In the optical system according to the present embodiment, as shown in fig. 5, illumination light output from the light source 11 is converted into substantially parallel light by the illumination lens 12, and is applied to the display element 13 (for example, a liquid crystal display element). Thereafter, the display element 13 outputs image light containing image information, which is reflected toward the eyeball by the reflection unit 5 having positive refractive power, so that the viewer can see a virtual image of the display element 13.

As shown in fig. 5, in the optical axis cross section along the paper surface direction of the optical system according to the present embodiment, the aperture of the reflection unit 5 is smallest. In other words, for an optical axis section parallel to the incident surface of the reflection unit 5, the reflection unit 5 functions as a substantial aperture stop in the optical system according to the present embodiment, or it can be said that there is an exit pupil position in the reflection unit 5. In this way, in the optical system according to the present embodiment, since the reflection unit 5 is the exit pupil position, the shape of the reflection unit 5 can be determined regardless of the image shape (i.e., the shape of the display element). Therefore, in the present embodiment, as described above, even if the display element 13 is in the horizontally long rectangular shape, the reflection unit 5 may be in the vertically long rectangular shape.

In addition, it is preferable that the apparatus is configured such that the image of the light source 11 will be located near the reflection unit 5. According to this configuration, since light diffused from the image of the light source 11 is reflected by the reflection unit 5 in a condensed state, improved illumination efficiency can be obtained.

Fig. 6 is a schematic diagram showing a difference between (a) an optical axis section in the lateral direction (i.e., an optical axis section parallel to the incident surface of the reflection unit) and (b) an optical axis section in the longitudinal direction (i.e., an optical axis section perpendicular to the incident surface of the reflection unit) of the optical system according to the present embodiment. It should be noted that, in fig. 6, for the purpose of description with respect to the paper surface, the light reflected by the reflection unit 5 is represented as a straight line.

In fig. 6A and 6B, a principal ray on the optical axis, an edge ray on the optical axis, a principal ray outside the optical axis, and an edge ray outside the optical axis are indicated by a two-dot chain line, a solid line, a one-dot chain line, and a broken line, respectively. As shown in fig. 6A, in the optical system according to the present embodiment, the lateral light flux is defined by the reflection unit 5 (in other words, the reflection unit 5 functions as an aperture stop). Thus, marginal rays outside the optical axis intersect the optical axis. On the other hand, as shown in fig. 6B, since the reflection unit 5 has a sufficiently large aperture for the longitudinal direction, the reflection unit 5 does not function as a substantial aperture stop, and thus the eye pupil 10 functions as an aperture stop.

It should be noted that although the eyeglass type image display device 1 shown in the present embodiment is configured to display an electronic image to the right eye, it may be configured to display an electronic image to the left eye.

(second embodiment)

Fig. 7 is a block diagram schematically illustrating a glasses-type image display device according to a second embodiment of the present invention. In the schematic diagram, eyeballs 2 of his/her right eye when the viewer wears the glasses-type image display device 1 are also shown. As shown in the schematic diagram, the glasses-type image display device 1 according to the present embodiment is provided with: an image output unit 4 provided on a temple 9 of the glasses; a deflection prism 15 for deflecting an angle of the image light output from the image output unit 4; and a reflection unit 5 that is disposed adjacent to the eyeglass lens 6 and reflects the image light emitted from the deflection prism 15 toward the eyeball 2 of the viewer.

The image output unit 4 has a display element 13 therein for displaying a two-dimensional image, and outputs image light. As in the case of the first embodiment, a general-purpose display element such as a liquid crystal display element and an organic EL element can be used as the display element 13. Thereafter, the image light output from the display element 13 (e.g., the image output unit 4) is incident on the deflection prism 15, deflected by 50 ° to 70 °, and exits toward the reflection unit. As a reflection member having a positive refractive power, the reflection unit 5 enlarges the image of the display element 13, and the viewer sees a virtual image of the display element 13. In the embodiment shown in fig. 7, the glasses type image display device has a longitudinal aberration correction lens 14, the longitudinal aberration correction lens 14 is integrated in a deflection prism 15, and corrects aberration caused by decentering of the reflection unit 5.

In addition, as an example of the deflection prism 15, a prism having an apex angle of 30 °, 60 °, and 90 ° (referred to as a 30 ° prism) may be used. When a 30 ° prism is used, a 60 ° deflection can be achieved as follows: the image light is made to enter perpendicularly to the surface opposite to the 90 ° apex angle, the image light is reflected by the surface opposite to the 60 ° apex angle, the image light is totally reflected by the surface opposite to the 90 ° apex angle, and then the image light is emitted from the surface opposite to the 30 ° apex angle.

The reflection unit 5 is a reflection member having a positive refractive power, and is provided so that it reflects the image light output from the image output unit 4 toward the eyeball 2 of the viewer when the viewer wears glasses, so that the viewer can see a virtual image of the two-dimensional image. As in the case of the first embodiment, (a) a front surface mirror, (b) a rear surface mirror, (c) a mirror embedded in a spectacle lens, and (d) a total reflection prism, etc. may be used as the reflection unit 5 (see fig. 2). It should be noted that, as in the case of the first embodiment, the reflection unit 5 is disposed at a position such that the reflection unit 5 does not cover the pupils 10 of the eyes of the viewer with respect to the projection section in the front direction of the viewer (see fig. 3). In addition, in the present embodiment, the reflection unit 5 is generally provided at this position, which allows the viewer to sufficiently secure his/her field of view so that he/she can safely move around even when the viewer wears the glasses-type image display device according to the present embodiment. Specifically, in the present embodiment, the deflecting prism 15 allows light to be incident on the reflecting unit 5 at a sharper angle than in the first embodiment, so that the reflecting unit 5 can be disposed at a position less blocking a field of view.

In the present embodiment shown in fig. 7, the deflection prism 15 is held by the post 7 of the spectacles. In addition, the image output unit 4 is held by the temple 9 of the eyeglasses, and is movable and adjustable in a direction perpendicular to the display surface of the display element 13. With this configuration, the diopter can be adjusted by changing the distance between the display element 13 and the deflection prism 15. In addition, if the display element 13 is movable and adjustable parallel to the display surface, interpupillary adjustment may be performed.

Fig. 8 is a basic block diagram showing optical elements selected in the present embodiment for describing the optical system according to the present embodiment in more detail. As shown in fig. 8, in the optical system according to the present embodiment, image light containing image information is output from the display element 13, deflected by the deflection prism 15, and guided to the reflection unit 5. The reflection unit 5 reflects the incident image light toward the pupil 10 of the eye of the viewer. In this case, the direction of the incident surface of the reflection unit 5 is the same as the direction of the paper surface, and the direction is substantially horizontal when viewed from the viewer. In addition, the longitudinal aberration correction lens 14 integrated in the deflection prism 15 corrects aberration caused by decentering of the reflection unit 5. As can be seen, also in the present embodiment, as in the case of the first embodiment, the light flux diameter of the optical axis section in the paper surface direction is smallest at the reflection unit 5. In other words, also in the present embodiment, the reflection unit 5 substantially functions as an aperture stop for an optical axis cross section in the incident surface direction. As described above, in the present embodiment as well, since the reflection unit 5 is the pupil position, the reflection unit 5 may be long and rectangular in the longitudinal direction even if the display element 13 is long and rectangular in the lateral direction.

As can be seen in the basic block diagram shown in fig. 8, in the present embodiment, the distance between the display element 13 and the reflection unit 5 is changed by changing the distance between the display element 13 and the deflection prism 15, whereby diopter adjustment can be performed. In addition, if the display element 13 is movable and adjustable in parallel to the display surface, the projection position of the display element 13 to the eye pupil 10 is shifted in parallel, and therefore, a configuration capable of performing interpupillary adjustment can be obtained.

Fig. 9 shows another example of interpupillary adjustment according to the present embodiment. Fig. 9A shows only the optical elements, and fig. 9B shows the interpupillary adjustment mechanism.

In fig. 9A, as in the case of the optical element shown in fig. 8, image light containing image information is output from the display element 13, deflected by the deflection prism 15, and guided to the reflection unit 5. Thereafter, the reflection unit 5 reflects the incident image light toward the eye pupil 10 of the viewer. At this time, the image output unit (in fig. 9A, including the display element 13, the deflection prism 15, and the longitudinal aberration correction lens 14) rotates around the reflection unit 5. As a result, since the visible position on the pupil 10 of the eye of the viewer is shifted, interpupillary adjustment can be achieved.

According to an example of the interpupillary adjustment structure, in fig. 9B, the image output unit 4 has an arc-shaped guide 21 centered on the reflection unit 5, and the image output unit 4 is held by the eyeglass frame 3 through this guide 21, thereby realizing a configuration that allows the image output unit 4 to be rotatably held around the reflection unit 5, and realizing a glasses-type image display device capable of performing interpupillary adjustment.

Fig. 10 is a schematic diagram showing another example of interpupillary adjustment according to the present embodiment. Fig. 10A shows only the optical elements, and fig. 10B shows the interpupillary adjustment mechanism.

As in the case of the optical element shown in fig. 8, in fig. 10A, image light containing image information is output from the display element 13, deflected by the deflection prism 15, and guided to the reflection unit 5. Thereafter, the reflection unit 5 reflects the incident image light toward the eye pupil 10 of the viewer. At this time, the reflecting unit 5 rotates about an axis located in the reflecting surface of the reflecting unit. As a result, the visible position on the pupil 10 of the eye of the viewer is shifted, so that interpupillary adjustment can be achieved.

According to the example of the interpupillary adjustment mechanism shown in fig. 10B, a groove having a concave surface 16 is formed in the eyeglass lens, and further, a through hole 17 is provided on a part of the groove to pass through the eyeglass lens. For the reflection unit 5, the convex surface 19 is provided as a rear surface of the reflection surface 18, and a shank (knob)20 passing through the through hole 17 is formed. The concave surface 16 and the convex surface 19 are slidably fitted to each other, and the reflecting surface 18 is deflected by a shank 20 passing through the through hole 17. With this configuration, the centers of curvature of the concave surface 16 and the convex surface 19 will become the centers of rotation of the reflecting surface 18, thereby achieving rotation about an axis located in the reflecting surface. That is, a glasses-type image display device capable of performing interpupillary adjustment can be realized.

It should be noted that although examples of the interpupillary adjustment with reference to fig. 9 and 10 are shown using the second embodiment, these examples may also be appropriately performed by the first embodiment.

(third embodiment)

Fig. 11 is a basic block diagram showing selected optical elements according to the present embodiment for showing an optical system of the third embodiment employing a toroidal mirror (toroidal mirror) as a reflecting member of the reflecting unit 5. The configuration of the glasses-type image display device employing the optical system according to the present embodiment may be the same as that of the second embodiment, for example. In other words, the glasses type image display device according to the third embodiment is provided with: an image output unit 4 having a display element 13 therein and provided on a temple 9 of the glasses; a deflection prism 15 for deflecting an angle of the image light output from the image output unit 4; and a reflection unit 5 that is disposed adjacent to the eyeglass lens 6 and reflects the image light emitted from the deflection prism 15 toward the eyeball 2 of the viewer.

As shown in fig. 11A, in the optical system according to the present embodiment, light containing image information is output from the display element 13, deflected by the deflection prism 15, and guided to the reflection unit 5. The reflection unit 5 reflects the incident image light toward the pupil 10 of the eye of the viewer. As in the case of the first embodiment, also in the present embodiment, the light flux diameter of the optical axis cross section in the paper surface direction is smallest at the reflection unit 5. In other words, also in the present embodiment, the reflection unit 5 functions as a substantial aperture stop with respect to the optical axis cross section in the incident surface direction. Therefore, also in the present embodiment, since the reflection unit 5 is at the pupil position, the reflection unit 5 may be long and rectangular in the longitudinal direction even if the display element 13 is long and rectangular in the lateral direction. It should be noted that fig. 11A also shows a cover glass 22 that protects the display element 13 in the image output unit 4.

Fig. 11B is a schematic diagram showing the shape of the reflection surface 18 of the reflection unit 5. As described above, the reflecting surface 18 according to the present embodiment has a longitudinally long rectangular shape. It should be noted that the longitudinally long rectangle refers to a shape in which the width in the direction parallel to the incident surface of the image light is narrower than the width in the direction perpendicular to the incident surface of the image light. The reflection surface 18 according to the present embodiment is a toroidal surface, and has a relationship represented by Rx > Ry, where Ry is a radius of curvature perpendicular to the incidence surface and Rx is a radius of curvature parallel to the incidence surface. In other words, with the reflecting surface 18 according to the present embodiment, the radius of curvature in the narrower width direction is larger than the radius of curvature in the wider width direction. In this way, astigmatic differences caused by decentering are corrected with the toroidal mirror of the reflecting surface 18. In the example shown in fig. 11B, the width in the direction parallel to the incident surface is 2.5mm, and the width in the direction perpendicular to the incident surface is 6.0 mm. In addition, the radius of curvature parallel to the incident surface was 86.7mm, and the radius of curvature perpendicular to the incident surface was 59.1 mm.

(fourth embodiment)

Fig. 12 is a block diagram schematically illustrating a glasses-type image display device according to a fourth embodiment of the present invention. The schematic view also shows the eyeballs 2 of the viewer when he/she wears the glasses-type image display device 1. As shown in the drawing, the glasses-type image display device 1 according to the present embodiment includes: a display element 13 provided on the temple 9 of the eyeglasses; and a reflection unit 5 that is disposed adjacent to the eyeglass lens 6 and reflects the image light output from the display element 13 toward the eyeball 2 of the viewer.

In the present embodiment, a free surface mirror is used as the reflecting member of the reflecting unit 5. In addition, the display element 13 is disposed obliquely with respect to the optical axis, so that an eccentric aberration caused by eccentricity of the reflection unit 5 can be reduced. In addition, in the configuration of the present embodiment, by disposing the display element 13 obliquely, the display element 13 can be disposed approximately parallel to the eyeglass frame 3, so that a configuration with a smaller volume can be realized. It should be noted that in the configuration according to the present embodiment shown in fig. 12, it is preferable to use an organic EL panel that does not require a backlight as the display element 13.

The effect of correcting the eccentric aberration obtained by obliquely disposing the display element 13 is shown below with reference to fig. 13 and 14.

Fig. 13 is a ray diagram of the optical system according to the present embodiment based on lens data shown below. Fig. 13 is a light ray diagram traced back from a virtual image plane (not shown) S0, which shows sequential tracing from the pupil S1 to the display surface S6 of the display element.

(lens data for the fourth embodiment: corresponding to FIG. 13)

Flour mark

Radius of curvature

Distance between faces

Eccentric center

Refractive index

Abbe number

S0 (noodle)	∞	-1000.00
						S1	∞	12.00
S2	FFS[1]	-34.23	Eccentric [1]]
						S3	∞	-1.00	Eccentric [2]]	1.4917	55.3
S4	∞	-2.30
						S5	∞	-0.70		1.5168	64.1
S6 (image plane)	∞	0.00

·FFS[1]：

C4 -7.7508e-003 C6 -5.2233e-003 C8 -4.0470e-005

C10 -3.8198e-005 C11 -4.6443e-007 C13 2.4738e-006

C15 2.0797e-006 C17 -1.4429e-006 C19 -1.5141e-006

C21 -1.5459e-007

Eccentricity [1 ]:

X 0.00 Y 0.00 Z 0.00

α -35.00 β 0.00 γ 0.00

eccentricity [2]

X 0.00 Y -1.70 Z -1.30

α -35.00 β 0.00 γ 0.00

Fig. 14 is a light ray diagram showing a state in which the display element and the cover glass are not obliquely disposed to show the effect of the fourth embodiment based on lens data shown below. Fig. 14 is a ray diagram traced back from the virtual image plane (not shown) S1, showing sequential tracing from the pupil S1 to the display surface S6. The difference between fig. 13 and fig. 14 is that: a plurality of faces from the third face S3 (the top face of the cover glass) to the sixth face S6 (the display surface of the display element) are not obliquely arranged.

(for lens data when the display element is vertically arranged: corresponding to FIG. 14)

Flour mark	Radius of curvature	Distance between faces	Eccentric center	Refractive index	Abbe number
						S0 (noodle)	∞	-1000.00
S1	∞	12.00
						S2	FFS[1]	-34.23	Eccentric [1]]
S3	∞	-1.00		1.4917	55.3

S4	∞	-2.30
						S5	∞	-0.70		1.5168	64.1
S6 (image plane)	∞	0.00

·FFS[1]：

C4 -7.7508e-003 C6 -5.2233e-003 C8 -4.0470e-005

C10 -3.8198e-005 C11 -4.6443e-007 C13 2.4738e-006

C15 2.0797e-006 C17 -1.4429e-006 C19 -1.5141e-006

C21 -1.5459e-007

Eccentricity [1 ]:

X 0.00 Y 0.00 Z 0.00

α -35.00 β 0.00 γ 0.00

as can be seen from comparison between fig. 13 and 14, particularly in the vicinity of the sixth surface S6, the degree of disturbance (turbulant) of the light ray shown in fig. 13 is lower than that of the light ray shown in fig. 14. In other words, according to the fourth embodiment of the present invention, it is understood that the decentering aberration caused by the decentering of the reflection unit can be reduced by disposing the display element 13 obliquely.

Now, the effect of reducing the decentering aberration due to the longitudinally long reflecting member according to the present invention will be described with the free-surface optical system according to the present invention. It should be noted that the effect of reducing the decentering aberration due to the longitudinally long reflecting member according to the present invention is not limited to the optical system of the free surface mirror, and similar effects are also produced for other embodiments according to the present invention.

Fig. 15 is a ray diagram of an optical system having a free surface mirror according to the present invention based on lens data shown below. Fig. 15 is a light ray diagram traced back from a virtual image plane (not shown) S0, and shows the display surface S6 traced from the pupil S1 to the display element in order. The difference between fig. 15 and fig. 13 is that: the cover glass (S3 and S4 in fig. 13) is not present in fig. 15.

Flour mark	Radius of curvature	Distance between faces	Eccentric center	Refractive index	Abbe number
						S0 (noodle)	∞	-1000.00
S1	∞	12.00
						S2	FFS[1]	-31.02	Eccentric [1]]
S3	∞	-0.70	Eccentric [2]]	1.5168	61.4
						S4 (image plane)	∞	-0.00

·FFS[1]：

C4 -1.1279e-002 C6 -7.6893e-003 C8 -1.2511e-004

C10 -8.5881e-005 C11 -3.1333e-005 C13 -6.5199e-006

C15 -3.7601e-006 C17 -2.1593e-006 C19 -1.6531e-006

C21 -9.6704e-007

Eccentricity [1 ]:

X 0.00 Y 0.00 Z 0.00

α -35.00 β 0.00 γ 0.00

eccentricity [2]

X 0.00 Y -1.56 Z 5.21

α -24.30 β 0.00 γ 0.00

For the above-mentioned lens data, fig. 16, 17, and 18 show lateral aberration diagrams at each point of the maximum image height in the case where the shape of the second face S2 (free-surface mirror) is circular, longitudinally long, and laterally long, respectively. Fig. 16 is an aberration diagram in the case where the reflection surface of the free surface mirror is circular with a radius of 1.74 mm. Fig. 17 is an aberration diagram in the case where the reflection surface of the free surface mirror is rectangular in shape (X is 0.86 × 2mm, and Y is 1.74 × 2mm), and fig. 18 is an aberration diagram in the case where the reflection surface of the free surface mirror is rectangular in shape (X is 1.74 × 2mm, and Y is 0.86 × 2mm), where X is a lateral direction (parallel to the incident surface) and Y is a longitudinal direction (perpendicular to the incident surface).

As can be seen from fig. 16, with the aberration according to the present optical system, the aberration in the X direction is larger than the aberration in the Y direction. Therefore, if the reflection surface of the free surface mirror is restricted in the X direction, the aberration in the X direction is reduced. When comparing the aberration diagram of fig. 17 in which the reflection surface of the free surface mirror is restricted in the X direction with the aberration diagram of fig. 18 in which the reflection surface of the free surface mirror is restricted in the Y direction, it is apparent that the aberration diagram of fig. 17 obtains better aberration correction.

(fifth embodiment)

Fig. 19 is a block diagram schematically illustrating a glasses-type image display device according to a fifth embodiment of the present invention. The schematic view also shows the eyeballs 2 of the viewer when he/she wears the glasses-type image display device 1. As shown in the drawing, the glasses-type image display device 1 according to the present embodiment includes: a display element 13 provided on the temple 9 of the eyeglasses; and a reflection unit 5 that is disposed adjacent to the eyeglass lens 6 and reflects the image light output from the display element 13 toward the eyeball 2 of the viewer.

Also in the present embodiment, a free surface mirror is used as the reflecting member of the reflecting unit 5. In addition, the decentering aberration caused by the decentering of the reflection unit 5 can be reduced by disposing the display element 13 obliquely with respect to the optical axis. In addition, as for the reflection surface of the reflection unit 5, the decentering aberration can be further reduced by making the width parallel to the incident surface smaller than the width perpendicular to the incident surface (longitudinally long shape).

The display element 13 according to the present embodiment is a transmissive liquid crystal display element. Therefore, it is necessary to apply illumination light from the rear side of the display element 13. In the present embodiment, the deflection prism 15 is disposed on the rear side of the display element 13, and the illumination light from the light source 11 is deflected by the deflection prism 15 and then applied to the rear side of the display element 13. In addition, in terms of configuration and production, it is preferable that the illumination lens 12 is integrally molded on the incident surface of the deflection prism 15 to which the illumination light from the light source 11 is applied.

(sixth embodiment)

Fig. 20 is a block diagram schematically illustrating a glasses-type image display device according to a sixth embodiment of the present invention. The schematic view also shows the eyeballs 2 of the viewer when he/she wears the glasses-type image display device 1. As shown in the figure, the glasses-type image display device 1 according to the present embodiment has: a display element 13 provided on the temple 9 of the eyeglasses; and a reflection unit 5 that is disposed adjacent to the eyeglass lens 6 and reflects the image light output from the display element 13 toward the eyeball 2 of the viewer.

Also in the present embodiment, a free surface mirror is used as the reflecting member of the reflecting unit 5. In addition, the decentering aberration caused by the decentering of the reflection unit 5 can be reduced by disposing the display element 13 obliquely with respect to the optical axis. In addition, as for the reflection surface of the reflection unit 5, the decentering aberration can be further reduced by making the width parallel to the incident surface smaller than the width perpendicular to the incident surface (longitudinally long shape).

The display element 13 according to the present embodiment is a reflective display element such as LCOS and DMD. Therefore, illumination light needs to be applied from the surface of the display element 13. In the present embodiment, the deflection prism 15 is provided on the surface of the display element 13, and the illumination light from the light source 11 is deflected by the deflection prism 15 and then applied to the surface of the display element 13. In addition, in terms of configuration and production, it is preferable that the illumination lens 12 is integrally molded on the incident surface of the deflection prism 15 to which the illumination light from the light source 11 is applied.

(seventh embodiment)

Fig. 21 is a block diagram schematically illustrating a glasses-type image display device according to a seventh embodiment of the present invention. In the present embodiment, the use of the glasses-type image display apparatus illustrated with reference to fig. 7 is extended to a binocular application. In other words, the glasses-type image display device 1 according to the present embodiment includes: an image output unit 4 provided on a temple 9 of the glasses; a deflection prism 15 for deflecting the image light output from the image output unit 4; a longitudinal aberration correction lens 14 for correcting longitudinal aberration of the image light; and a reflection unit 5 for reflecting the image light from the longitudinal aberration correction lens 14 toward the respective eyeballs 2 of the right and left eyes of the viewer. Here, each function of the present embodiment is similar to that of the glasses-type image display device according to the second embodiment, and thus similar descriptions are omitted by assigning each same symbol in the drawings. In other words, the glasses-type image display device according to the present embodiment has the functions and effects possessed by the glasses-type image display device according to the second embodiment.

As shown in fig. 21, in the present embodiment, the incident angle of the image light is the same for the right eye and the left eye. In other words, a viewer wearing the glasses-type image display device according to the present embodiment sees one image in front of him/her. At this time, a three-dimensional image can be displayed by displaying inconsistent images to the right and left eyes. In addition, by reducing the width of the reflection unit 5 in the short side direction to less than 4mm (average pupil diameter of a person), see-through display can be realized, whereby a three-dimensional image can be superimposed on a background image around a viewer, and as a result, very realistic stereoscopic display can be realized. In addition, the incident angle of the image light may be inwardly angled corresponding to the amount of convergence of the eyeball.

It should be noted that although the present embodiment is described as an extended application of the second embodiment, the concept of the present embodiment is not limited to the second embodiment, and other embodiments of the present invention may be extended to a binocular application.

(eighth embodiment)

Fig. 22 is a block diagram schematically illustrating a glasses-type image display device according to an eighth embodiment of the present invention. In the present embodiment, the use of the glasses-type image display device according to the second embodiment shown with reference to fig. 7 is expanded to a binocular application. In other words, the glasses-type image display device 1 according to the present embodiment includes: an image output unit 4 provided on a temple 9 of the glasses; a deflection prism 15 for deflecting the image light output from the image output unit 4; a longitudinal aberration correction lens 14 for correcting longitudinal aberration of the image light; and a reflection unit 5 for reflecting the image light emitted from the longitudinal aberration correction lens 14 toward the respective eyeballs 2 of the right and left eyes of the viewer. Here, each function of the present embodiment is similar to that of the glasses-type image display device according to the second embodiment, and thus similar descriptions are omitted by assigning the same symbols in the drawings. In other words, the glasses-type image display device according to the present embodiment has the functions and effects possessed by the glasses-type image display device according to the second embodiment.

As shown in fig. 22, in the present embodiment, for the right and left eyes of the viewer, the incident angle of the image light is directed outward when viewed from the viewer side. That is, a viewer wearing the glasses-type image display device according to the present embodiment sees any one of the images. At this time, by displaying different images between the right eye and the left eye, the viewer can selectively see a desired display. In other words, by putting the respective images for the right eye and for the left eye together, information of the two images can be displayed. Therefore, the present embodiment is suitable for a case when the glasses-type image display device according to the present invention is used as an information providing device.

It should be noted that although the present embodiment is described as an extended application of the second embodiment, the concept of the present embodiment is not limited to the second embodiment, and the use of other embodiments may be extended to a binocular application.

(Note of description of lens data)

For the embodiment used to describe the invention, the eccentricity of each face is in the Y-Z plane, and the only plane of symmetry of the asymmetric free surface of each rotation is the Y-Z plane.

For the eccentric surface, the eccentric amount from the origin center of the optical system to the surface top position of the surface (X, Y, and Z-axis directions are referred to as X, Y and Z, respectively) and the tilt angles (α, β, γ (°, respectively)) around the respective central axes of the surface, i.e., the X, Y, and Z axes (the Z axis is the Z axis of the formula (a) shown below for the free surface, and the X axis is the X axis of the formula (b) shown below for the aspherical surface). In this case, each positive value of α and β represents counterclockwise rotation with respect to the positive direction of each axis, and a positive value of γ represents clockwise rotation with respect to the positive direction of the Z axis. The central axis of the surface is rotated by angles α, β, γ as follows: first, the central axis of the plane and the orthogonal coordinate systems of X, Y and Z are rotated counterclockwise by α degrees about the X axis, then the central axis of the rotated plane is rotated counterclockwise by β degrees about the Y axis of the new coordinate system, and at the same time, the coordinate system rotated once is rotated counterclockwise by β degrees about the Y axis, and then the central axis of the plane rotated twice is rotated clockwise by γ degrees about the Z axis of the new coordinate system.

In addition, in the optically active surface constituting the optical system of each embodiment, when the specific surface and the subsequent surface form a coaxial optical system (including a surface reflection prism), a surface distance is provided. In addition to this, the medium refractive index and abbe number are provided according to a common method.

It should be noted that the free surface employed in the present invention is defined by the following formula (a). The Z-axis of the formula is the axis of the free surface.

Wherein the initial term of formula (a) is a spherical term and the second term is a free-surface term.

In the case of the spherical terms,

r: the radius of curvature of the apex,

k: korenich constant (conic constant), and

in the case of the free-surface item,

provided C_j(j is an integer greater than 1) is a coefficient.

In general, neither the X-Z plane nor the Y-Z plane has a plane of symmetry for the free surfaces described above. However, in the present invention, when all odd power terms of X are zero, a free surface having only one plane of symmetry parallel to the Y-Z plane can be obtained. For example, in the above formula (a), if C₂、C₅、C₇、C₉、C₁₂、C₁₄、C₁₆、C₁₈、C₂₀、C₂₃、C₂₅、C₂₇、C₂₉、C₃₁、C₃₃、C₃₅… is zero, then this can be achieved.

In addition, when all odd power terms of Y are zero, a free surface having only one plane of symmetry parallel to the X-Z plane is obtained. For example, in the above formula, if C₃、C₅、C₈、C₁₀、C₁₂、C₁₄、C₁₇、C₁₉、C₂₁、C₂₃、C₂₅、C₂₇、C₃₀、C₃₂、C₃₄、C₃₆… is zero, then this can be achieved.

In addition, if any one of the directions of the above-described symmetry planes is defined as a symmetry plane, and the decentering direction of the optical system is, for example, a Y-axis direction with respect to the symmetry plane parallel to the Y-Z plane and an X-axis direction with respect to the symmetry plane parallel to the X-Z plane, rotational asymmetric aberration caused by decentering can be effectively corrected, while the ease of manufacturing can be improved.

In addition, as described above, the formula (a) is provided as only one example, the present invention is characterized in that the rotationally asymmetric aberration caused by eccentricity is corrected and the ease of manufacturing is improved by using the plane-symmetric free surface having only one symmetric surface, and it is apparent that the same effect can be obtained according to any other defined formula.

It should be noted that the items for which no data is given with respect to the free surface are zero. The refractive index is for line d (wavelength: 587.56 nm). The length unit is mm.

The present application claims priority from japanese patent application No.2009-200921, filed on 8/31/2009, the contents of which are incorporated herein by reference.

Claims (19)

1. An eyeglass-type image display device, comprising:

an image output unit including a display element that displays an image and is provided on a frame of glasses; and

a reflection unit disposed adjacent to at least one eyeglass lens and configured to reflect image light output from the image output unit toward an eyeball of a viewer when the viewer wears the eyeglasses so that the viewer can see a virtual image of the image,

wherein the reflection unit is a reflection member having a positive refractive power, and

an effective light flux output from the image output unit and reaching an eyeball of the viewer is configured to: so that, for an optical axis section parallel to an incident plane of the optical axis on the reflection unit, a width of an effective luminous flux perpendicular to the optical axis is smallest at the reflection unit.

2. The eyeglass type image display device according to claim 1, wherein a minimum width of a cross section perpendicular to the optical axis is less than 4mm, the 4mm being an average pupil diameter of a human.

3. The eyeglass type image display device according to claim 1, wherein a width in a direction parallel to the incident surface is smaller than a width in a direction perpendicular to the incident surface for the reflection surface of the reflection member.

4. The glasses-type image display device according to claim 3, wherein the display element is a rectangular shape whose longitudinal length and lateral length are different from each other, and the display element is disposed such that a longitudinal direction of the rectangular shape corresponds to a minimum width direction of a reflection surface of the reflection member.

5. The glasses-type image display device according to claim 4, wherein a reflection surface of the reflection member is represented by Rx > Ry, wherein a radius of curvature perpendicular to the incidence surface is Ry and a radius of curvature parallel to the incidence surface is Rx.

6. The glasses-type image display device according to claim 4, wherein the reflection surface of the reflection member is a free surface.

7. The eyeglass type image display device according to claim 1, wherein for an effective luminous flux that is output from the image output unit and reaches the eyeball of the viewer, a pupil position in a lateral direction is located near the reflection member, the pupil position in a longitudinal direction being closer to the pupil of the eyeball of the viewer than the pupil position in the lateral direction, the pupil position in the lateral direction being an exit pupil position for an optical axis section parallel to an incident surface of the reflection member, the pupil position in the longitudinal direction being an exit pupil position for an optical axis section perpendicular to the incident surface of the reflection member.

8. The glasses-type image display device according to claim 1, wherein the reflection member is embedded in the glasses lens.

9. The glasses-type image display device according to claim 1, wherein the image output unit is rotatably held around a reflection surface of the reflection unit.

10. The eyeglass type image display device according to claim 1, wherein the reflection unit is rotatably held with a rotation axis thereof located in a reflection surface of the reflection member.

11. The glasses-type image display device according to claim 1, wherein a deflection prism is provided between the display element and a reflection unit.

12. The glasses-type image display device according to claim 11, wherein the display element is disposed to face a forward direction of a viewer, and light output from the display element is incident on the deflection prism, deflected by 50 ° to 70 °, and emitted toward the reflection unit.

13. The glasses-type image display device according to claim 11, wherein the deflection prism is held by a temple of the glasses, the display element is held by a temple of the glasses, and the display element is movable and adjustable in a direction perpendicular to a display surface.

14. The glasses-type image display device according to claim 11, wherein the deflection prism is held by a temple of the glasses, the display element is held by a temple of the glasses, and the display element is movable and adjustable in a direction parallel to a display surface.

15. The eyeglass type image display device according to claim 11, wherein a longitudinal aberration correction lens for correcting a longitudinal aberration caused by decentering of the reflection unit is provided between the display element and the reflection unit.

16. The eyeglass type image display device of claim 15, wherein a surface of the longitudinal aberration correction lens is in a shape of a free surface.

17. The glasses-type image display device according to claim 15, wherein the longitudinal aberration correction lens is integrated in a deflection prism.

18. The glasses-type image display device according to claim 1, wherein the display element is an organic EL.

19. The glasses-type image display device according to claim 1, wherein, with the reflection unit, a projection section with respect to a viewer forward direction is provided at a position where the projection section does not cover a pupil of the viewer.