JP2005195733A - Transparent substrate having microlens array and liquid crystal display device - Google Patents

Abstract

【Task】
To provide a transparent substrate with a microlens array and a liquid crystal display device which can achieve cost reduction and prevent deterioration of image display.
[Solution]
The transparent substrate 12 according to the present invention is used in a liquid crystal display device, on which a TFT element 11 and a transparent electrode 10 are formed. A microlens array 122 having a plurality of microlenses is formed on the surface of the transparent substrate 12, and a rim 121 that is the same as or higher than the apex of the microlens is formed on a part or all of the periphery of the microlens array 122. Has been.
[Selection] Figure 1

Description

  The present invention relates to a transparent substrate for a liquid crystal display device having a microlens array and a liquid crystal display device.

  The configuration of a conventional liquid crystal display device is shown in FIG. In the liquid crystal display device, a liquid crystal layer 7 is sandwiched between two transparent substrates 2 and 12. A polarizing film 1 is provided on the front side of the transparent substrate 2. On the back side of the transparent substrate 2, a black matrix 3, a color filter layer 4, a transparent electrode 5, and an alignment film 6 are formed. A spacer 8 is provided between the transparent substrate 2 and the transparent substrate 12. On the front side of the transparent substrate 12, a TFT element 11, a transparent electrode 10, and an alignment film 9 are formed. In addition, a light guide plate, a light source, a reflective layer, and the like are provided on the back side of the polarizing film 13. Information display is realized by controlling the voltage applied to the liquid crystal layer 7.

  In the liquid crystal display device having such a configuration, there is a problem that light from the back side is blocked by the TFT element 11 provided on the transparent substrate 12 on the back side, and the light use efficiency is lowered. In order to solve such a problem, a technique is proposed in which a microlens array sheet is arranged on the back side of the transparent substrate 12 so that light from the back side does not hit the TFT element 11 and the light use efficiency is increased. Has been.

The microlens array is manufactured by, for example, a manufacturing method described in Patent Document 1.
JP-A-8-166502

  In the conventional liquid crystal display device, the microlens array sheet for increasing the light use efficiency is provided on the back side of the transparent substrate 12 as an independent member, which increases the number of components and increases the cost. Met.

  In addition, when the polarizing film is fixed to the microlens array sheet, the peripheral area of the microlens array sheet is lower than the apex of the microlens, so the polarizing film is bent at that portion to ensure flatness. There is a problem in that image display is deteriorated.

  The present invention has been made to solve such problems, and a first object of the present invention is to provide a transparent substrate with a microlens array and a liquid crystal display device that can reduce the number of components and achieve cost reduction. .

  It is a second object of the present invention to provide a transparent substrate with a microlens array and a liquid crystal display device capable of preventing image display deterioration.

  A transparent substrate according to the present invention is a member for a liquid crystal display device comprising a transparent substrate on which a switching element and a transparent electrode are formed, and a polarizing plate placed on the transparent substrate, and is formed on the back surface. A microlens array having a plurality of microlenses and a rim that is formed on a part or all of the periphery of the microlens array on the back surface and has the same or higher rim as the apex of the microlens It is.

  Here, the side surface of the rim on the microlens array side is preferably a slope.

  The upper surface of the rim may be formed with a recess.

  Furthermore, the upper surface of the rim is preferably a rough surface.

  The rim in a preferred embodiment is formed of the same material as the microlens array.

  Moreover, the transparent substrate in a preferred embodiment is a glass substrate.

  Another transparent substrate according to the present invention is a transparent substrate on the front side of the liquid crystal display device, on which a transparent electrode is formed, and a polarizing plate is placed on the front side of the transparent substrate, The transparent substrate is formed on a part or all of the periphery of the microlens array on the front surface and a microlens array having a plurality of microlenses formed on the front surface. It has the same or higher rim as the apex.

  According to the present invention, it is possible to provide a transparent substrate with a microlens array and a liquid crystal display device that can reduce the number of components and achieve cost reduction. Further, it is possible to provide a transparent substrate with a microlens array and a liquid crystal display device that can prevent image display deterioration.

Embodiment 1 of the Invention
FIG. 1 is a sectional view of a liquid crystal display device according to Embodiment 1 of the present invention. In this liquid crystal display device, a liquid crystal 7 is sandwiched between two transparent substrates 2 and 12. A polarizing film 1 is provided on the front side (observer side) of the transparent substrate 2. A black matrix 3, a color filter layer 4, a transparent electrode 5, and an alignment film 6 are formed on the side of the transparent substrate 2 on which the liquid crystal layer 7 is provided (back side). A spacer 8 is provided between the transparent substrate 2 and the transparent substrate 12. On the front side of the transparent substrate 12, a TFT element 11, a transparent electrode 10, and an alignment film 9 are formed.

  The first embodiment is characterized in that a microlens array 122 is formed on the back side of the transparent substrate 12 and a rim 121 is formed.

  Here, each configuration in the liquid crystal display device will be described.

  The polarizing film 1 forms a polarizing layer. The polarizing film 1 has a transmission axis and an absorption axis orthogonal to each other, transmits linearly polarized light parallel to the transmission axis, and absorbs linearly polarized light parallel to the absorption axis.

  The transparent substrate 2 is a transparent substrate disposed on the front side. The transparent substrate 2 is made of, for example, glass or transparent resin. A retardation layer may be further provided between the polarizing film 1 and the transparent substrate 2. This retardation layer is composed of a retardation plate, a retardation film, and a laminate thereof, and converts linearly polarized light into elliptically polarized light.

  The black matrix 3 is a light shielding film disposed between the regions of the color filter layer 4. The color filter layer 4 is a layer provided in order to realize color display, and is composed of, for example, three types of regions that perform R, G, and B color display.

  The transparent electrode 5 is an electrode for forming a common electrode or the like, and is formed of, for example, ITO (Indium Tin Oxide). The alignment film 6 is a layer that is provided on the transparent substrate 2 and has a function of controlling the liquid crystal molecules in the liquid crystal layer 7 so as to have an alignment and tilt suitable for the operation mode of the liquid crystal. The liquid crystal layer 7 is a layer made of, for example, nematic liquid crystal. The spacer 8 is inserted in order to keep the distance between the transparent substrate 2 and the transparent substrate 12, that is, the cell gap constant.

  The alignment film 9 is a layer that is provided on the transparent substrate 12 and has a function of controlling the liquid crystal molecules in the liquid crystal layer 7 so as to have an alignment and tilt suitable for the operation mode of the liquid crystal. The transparent electrode 10 is an electrode for forming a display electrode or the like, and is formed of, for example, ITO. The TFT element 11 is a switching element for controlling application of a voltage to the liquid crystal layer 7.

  The transparent substrate 12 is made of, for example, glass, transparent resin such as polycarbonate or acrylic resin. The transparent substrate 12 is provided with a rim 121 and a microlens array 122 on the back side thereof, which will be described in detail later. The polarizing film 13 has a configuration equivalent to that of the polarizing film 1.

  In addition, although a light-guide plate, a light source, a reflective layer, etc. are provided in the back side of the polarizing film 13, description is abbreviate | omitted about these structures since it is a known structure.

  Then, the rear view of the transparent substrate 12 is shown in FIG. A rim 121 is provided on the transparent substrate 12 so as to surround the periphery thereof. That is, the rim 121 shown in FIG. 2 is a convex portion that is continuously formed at substantially the same height without being interrupted over the entire circumference of the transparent substrate 12. However, the rim 121 does not have to be provided over the entire circumference of the transparent substrate 12 and may be interrupted in part. Moreover, it is not necessary to provide in all four sides, and you may make it provide in two opposing sides. The rim 121 has a height equal to or higher than the apex (the highest point) of the microlens array 122. The rim 121 is integrated with the transparent substrate 12.

  The rim 121 may be made of the same material as the transparent substrate 12 or may be made of a different material. In the preferred embodiment, the rim 121 is made of the same material as the microlens array 122. For example, it is made of a transparent resin or glass, but it is not necessarily transparent.

  The microlens array 122 is provided with a microlens for each pixel. That is, the same number of pixels is provided. For example, in the case of a liquid crystal display device for a portable terminal, a set of microlens arrays 122 is configured by about 200,000 microlenses. The microlens protrudes in a convex shape from a regular hexagonal region, thereby forming a convex lens. Therefore, since the microlens array is directly provided on the transparent substrate, the positions of the pixels and the lenses match each other, and alignment is not required as in the case where they are configured by separate members.

  The micro lens array 122 refracts light so that light from the back side does not strike the TFT element 11. As a result, the light utilization efficiency is increased, and high-luminance display is possible.

  In the first embodiment of the present invention, the rim 121 is configured together with the microlens array 122 on the back side of the transparent substrate 12, for the following reason. The polarizing film 13 is provided on the back side of the transparent substrate 12 as described above. However, if the rim 121 is not formed, the polarizing film 13 is deformed in the peripheral region, and flatness is lost. More specifically, the polarizing film 13 bends in the direction (front side) in contact with the glass substrate 12 in the peripheral region. If the flatness of the polarizing film 13 is lost, desired optical performance cannot be obtained, and image display is deteriorated.

  Therefore, in Embodiment 1 of the present invention, the rim 121 is formed to maintain the flatness of the polarizing film in the peripheral region, thereby realizing high image display.

  Incidentally, as shown in FIG. 3, a large number of transparent substrates 12 are taken from a large plate glass 120. That is, first, a plurality of sets of rims 121 and microlens arrays 122 are formed on the sheet glass 120. Next, the sheet glass 120 is cut so that each set is separated. Thereby, a plurality of transparent substrates 12 can be manufactured from one plate-like glass 120.

  Then, an example of the manufacturing method of the transparent substrate 12 concerning this invention is demonstrated using FIG. FIG. 4 is a partial cross-sectional view for each process. First, as shown in FIG. 4A, a positive photoresist 102 is applied on a substrate 101 by spin coating or the like. Next, the resist 102 is irradiated with laser light. At this time, by using the fact that the reaction of the resist 102 varies depending on the intensity of the laser light emitted from the laser device, the intensity of the laser light is sequentially formed so that the shapes corresponding to the rim 121 and the microlens array 122 are configured. Scanning on the resist 102 is performed while adjusting the. FIG. 5 shows the state of the laser beam irradiation operation. In FIG. 5, laser light is irradiated from the laser device 200 onto the upper surface of the resist 102. As shown in FIG. 4B, an irradiated portion 1021 and an unirradiated portion 1022 are formed by the laser light irradiation. Since the transparent substrate 12 is processed using the laser light in this way, the rim 121 and the microlens array 122 can be formed integrally, and the shape of the rim 121 can be processed arbitrarily.

  Next, the resist in the irradiated portion 1021 is dissolved and removed with a developing solution. As a result, a substrate 101 as shown in FIG. 4C and a resist 1022 having a shape corresponding to the rim 121 and the microlens array 122 are formed.

  Further, after a conductive film is formed on the resist 1022 by sputtering or the like, a mold (plating stamper) 103 is formed by electrolytic plating. The mold 103 is made of, for example, Ni, Cu, or Au. The mold 103 can be formed by electroless plating instead of electrolytic plating. The state where the mold 103 is formed is shown in FIG.

  Thereafter, the substrate 101 and the resist 1022 are separated from the mold 103. Further, a molten UV (ultraviolet) curable resin 104 is poured into the mold 103 (FIG. 4E). Examples of the UV curable resin include polycarbonate (PC), acrylic, cycloolefin, polymethyl methacrylate (PMMA), and the like. A thermosetting resin may be used instead of the UV curable resin. Further, for example, the transparent substrate 12 which is a glass substrate is placed on the UV curable resin 104 and irradiated with ultraviolet rays to cure the UV curable resin 104 (FIG. 4F). Then, when the mold 103 is separated, the transparent substrate 12 having the rim 121 and the microlens array 122 formed on the surface is manufactured (FIG. 4G).

  Thereafter, a TFT element, a transparent electrode, and the like on the transparent substrate 12 are formed, and a liquid crystal panel is manufactured in combination with other layers. At this time, the upper surface of the rim 121 is fixed to the polarizing film 13 by an adhesive. Then, a liquid crystal panel is incorporated to complete a liquid crystal display device.

  In the manufacturing method shown in FIG. 4, each transparent substrate 12 is manufactured, but as described with reference to FIG. 3, the rim 121 and the microlens array 122 are formed on the sheet glass by the manufacturing method shown in FIG. Then, the transparent substrate 12 may be manufactured by cutting.

Embodiment 2 of the Invention
The transparent substrate according to the second embodiment of the present invention is characterized by the shape of the rim. FIG. 6 shows a partial cross-sectional view of the transparent substrate 12. As shown in FIG. 6, the rim 121 has an upper surface 1212 and a side surface 1211, but the side surface 1211 on the microlens array 122 side is an inclined surface. That is, the side surface 1211 is not perpendicular to the upper surface 1212 but is formed as a tapered surface having a certain inclination. Thus, when the side surface of the rim 121 on the microlens array 122 side is an inclined surface, it is easy to release from the mold, and the manufacturing yield can be improved.

Embodiment 3 of the Invention
The transparent substrate according to the third embodiment of the present invention is characterized by the shape of the rim. FIG. 7 shows a partial cross-sectional view of the transparent substrate 12. As shown in FIG. 7, the rim 121 has a recess 1213 on the upper surface 1212. In this recess 1213, an adhesive used for bonding the polarizing film 13 and the rim 121 is collected, and the adhesive strength can be increased. Further, it is possible to prevent the adhesive from being pushed out and attached to the microlens array 122.

Embodiment 4 of the Invention
The transparent substrate according to the fourth embodiment of the present invention is characterized by the shape of the rim. FIG. 8 shows a partial cross-sectional view of the transparent substrate 12. As shown in FIG. 8, the upper surface 1212 of the rim 121 has a rough surface. This also increases the adhesive strength between the polarizing film 13 and the rim 121.

Embodiment 5 of the Invention
In the liquid crystal display device according to the fifth exemplary embodiment of the present invention, the rim and the microlens array are provided on the front transparent substrate. FIG. 9 is a partial cross-sectional view of the liquid crystal display device. As shown in the figure, a rim 21 and a microlens array 22 are provided on the front surface of the transparent substrate 2 on the front surface side. Since the transparent substrate 2 on which the rim 21 and the microlens array 22 are formed has the same configuration as the transparent substrate 12 described in the first embodiment of the invention, detailed description thereof is omitted.

  Thus, by providing the microlens array 22 on the front surface of the transparent substrate 2 on the front surface side, the viewing angle can be widened. At the same time, since the rim 21 is provided, it is possible to ensure the flatness of a film such as the polarizing film 1 and further improve the optical characteristics.

Other embodiments.
The liquid crystal display device described above can be applied not only to a transmissive liquid crystal display device but also to a reflective liquid crystal display device.

It is a partial cross section figure of the liquid crystal display device concerning this invention. It is a rear view of the transparent substrate concerning this invention. It is a figure which shows the glass substrate before the transparent substrate concerning this invention is isolate | separated. It is a flowchart which shows the manufacturing method of the transparent substrate concerning this invention. It is a perspective view which shows the mode of one process in the manufacturing method of the transparent substrate concerning this invention. It is a partial cross section figure of the transparent substrate concerning this invention. It is a partial cross section figure of the transparent substrate concerning this invention. It is a partial cross section figure of the transparent substrate concerning this invention. It is a partial cross section figure of the liquid crystal display device concerning this invention. It is a partial cross section figure of the conventional liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polarizing film 2 Transparent substrate 3 Black matrix 4 Color filter layer 5 Transparent electrode 6 Alignment film 7 Liquid crystal layer 8 Spacer 9 Alignment film 10 Transparent electrode 11 TFT element 12 Transparent substrate 13 Polarizing film 121 Rim 122 Micro lens array

Claims (10)

A member for a liquid crystal display device comprising a transparent substrate on which a switching element and a transparent electrode are formed, and a polarizing plate placed on the transparent substrate,
The transparent substrate is
A microlens array having a plurality of microlenses formed on the back side surface;
A transparent substrate that is formed on a part or all of the periphery of the microlens array on the back surface, and has a rim that is the same as or higher than the apex of the microlens.   2. The transparent substrate according to claim 1, wherein a side surface of the rim on the microlens array side is a slope.   The transparent substrate according to claim 1, wherein a concave portion is formed on an upper surface of the rim.   The transparent substrate according to claim 1, wherein an upper surface of the rim is a rough surface.   The transparent substrate according to claim 1, wherein the rim is made of the same material as the microlens array.   The transparent substrate according to claim 1, wherein the transparent substrate is a glass substrate. In the liquid crystal display device is a transparent substrate on which a transparent electrode is formed on the front side, and a polarizing plate is placed on the front side of the transparent substrate.
A microlens array having a plurality of microlenses formed on the front side surface;
A transparent substrate formed on a part or all of the periphery of the microlens array on the surface on the front surface side, and having a rim that is the same as or higher than the apex of the microlens.   A liquid crystal display device comprising the transparent substrate according to claim 1. A method for producing a glassy transparent substrate used by forming a switching element and a transparent electrode in a liquid crystal display device,
Forming a plurality of sets of microlens arrays on one surface of the sheet glass;
And a step of cutting the sheet glass so that the plurality of sets of microlens arrays are separated. A method for manufacturing a transparent substrate, further comprising a step of forming a rim on one surface of the plate-like glass so as to surround each macro lens array.

Images