JPH07199188A - Liquid crystal display element and liquid crystal display device using the element - Google Patents

Abstract

PURPOSE:To provide a liquid crystal display element, which effectively guides incident light to an aperture part regardless of a light source of bad parallelism to obtain bright picture information display, and the liquid crystal display device on which a picture is bright and is easy to see. CONSTITUTION:One transparent substrate, on which the light radiated from a light source is made incident, out of a pair of transparent substrates between which liquid crystal is charged consists of the substrate where a first plane micro lens array 51 and a second plane micro lens array 52 are closely brought into contact with each other. Plane micro lens arrays 51 and 52 have unit lens parts 51a and 52a each of which has an area approximately equal to the area corresponding to one picture element of the picture element array of liquid crystal and which are arranged in the same array as picture elements of liquid crystal. Two plane micro lens arrays 51 and 52 have optical axes of unit lens parts 51a and 52a aligned, and focal lengths synthesized in respective unit lens parts are shortened, and focuses are arranged very closely to the liquid crystal face in the vicinity of the liquid crystal layer and about center parts of rear parts of corresponding picture elements, and in this state, they are closely brought into contact with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmissive liquid crystal display element for injecting liquid crystal between a pair of transparent substrates and displaying image information by the electro-optical effect of the liquid crystal, and a transmissive liquid crystal display element as a light valve. The liquid crystal display device used.

[0002]

2. Description of the Related Art The structure of a twisted nematic (TN) type liquid crystal display device, which is a typical example of a liquid crystal display device, has a structure in which a liquid crystal is injected between a pair of transparent substrates having transparent electrode coatings before and after a liquid crystal cell. And each polarization direction is 9
Two polarizers are arranged so that they are different by 0 °.
This twisted nematic (TN) liquid crystal display device controls the amount of incident light transmitted by combining the action of rotating the plane of polarization by the electro-optic effect of liquid crystal and the action of selecting the polarization component of the polarizer to control the amount of incident light. Displaying information. These liquid crystal display elements are disclosed in detail, for example, in "Basics and Applications of Liquid Crystal Electronics" edited by Sasaki, Ohmsha (1979). In the above liquid crystal display elements, metal wiring of electrodes in each pixel and The non-linear element or the switching element added as a means for individually controlling each pixel, and the gap (light-shielding portion) that does not contribute to the display such as the gap around the pixel electrode existed.
Therefore, particularly in a transmissive liquid crystal display element, of the light emitted from the light source and radiated to the liquid crystal display element, the light reaching the light-shielding portion does not pass through the liquid crystal display element, which reduces the light utilization efficiency. It was The light utilization efficiency is usually expressed by the aperture ratio of the liquid crystal display element. Here, the aperture ratio is defined as follows. Aperture ratio = effective area contributing to display in one pixel / area of one pixel whole region Improvement of light utilization efficiency (aperture ratio) of a liquid crystal display element has been a problem in this field.

Further, in order to make a display device using a liquid crystal display element compact, if the liquid crystal display element is miniaturized and the number of pixels of the liquid crystal display element is the same, the liquid crystal display element is downsized. The area of one pixel becomes smaller as it is blown out. Then, the ratio of the above-mentioned light-shielding portion to be closed in the pixel becomes large, and it becomes difficult to make it bright. Also,
In order to increase the resolution of a display device using a liquid crystal display element with the same size and high definition, it is necessary to reduce the pixel pitch, but in that case, if all the constituent elements of the liquid crystal display element can be reduced in a similar manner, light shielding is possible. The influence of the part does not change and the aperture ratio does not change. However, the width of the metal wiring of the electrode and the size of the additional element cannot be reduced to a certain extent or smaller in view of etching accuracy, alignment accuracy, and the like. As a result, the aperture ratio deteriorated when the definition was kept high. Here, as the transmissive liquid crystal display element and the liquid crystal display device with the improved aperture ratio, a microlens array as disclosed in, for example, JP-A-60-165622 and JP-A-61-11788. There is one that has.

[0004]

In each of the above-mentioned prior arts, the microlens array is formed on the substrate on the light incident side of the liquid crystal display element, and the characteristics of the light source for irradiation are not taken into consideration. It was Therefore, the optical characteristics of the liquid crystal element will be described with reference to FIG. FIG. 11 is a schematic cross-sectional view of a portion corresponding to one pixel of the liquid crystal display element, and the liquid crystal layer and the other transparent substrate are omitted. Usually, the dimension D of one pixel of the liquid crystal display device is about 100 μm, while the thickness t of the transparent substrate 12 is about 1 mm.
Therefore, the microlens array 10 formed on the substrate
The focal length f of the unit lens 10a of is calculated by the equation (1). The focal length f calculated from this equation is substantially equal to the thickness t of the transparent substrate 12. f = 1 / n≈t (1) l: distance from the rear principal point of the lens to the liquid crystal surface n: refractive index of the transparent substrate 12, that is, a long focal length with respect to the dimension D of one pixel It becomes the lens of. As a result, for example, in FIG. 11, when the incident light beam is completely parallel like the light beam 20a, the light beam can be focused on the opening 14 of the pixel. However, the incident ray is the ray 20
Rays b and 20c which are incident at a convergence angle θ with respect to the optical axis of the unit lens 10a of the microlens array 10 are
The light is condensed on the light shielding portion 16 that does not contribute to the display, and cannot be condensed in the opening 14 of the pixel. in this way,
The technique disclosed above has a disadvantage that a sufficient light collecting effect cannot be obtained.

Since the above-mentioned aperture ratio of a liquid crystal display element is usually 30 to 40%, the pixel size D is assumed to be 1
If it is 00 μm, the dimension d of the opening therein is 50 to 6
It becomes about 0 μm. Therefore, it is necessary to use a light source having an extremely high degree of parallelism such that the focusing angle θ of the incident light beam that can be condensed in the opening is about 2 to 3 ° according to the following formula (2). d = 2f · tan θ (2) However, a white light source such as a halogen lamp, a xenon lamp, a metal halide lamp or the like usually used as a light source of a liquid crystal display element has an extremely large focusing angle θ of about 0 to 10 °. Since it has a focusing angle component, a general liquid crystal display element cannot obtain a sufficient light-collecting effect. In addition, the value of the convergence angle θ that can collect light in this way tends to become smaller as the liquid crystal display element becomes finer.

As described above, in the above-mentioned prior art, a display device using a liquid crystal display element provided with a microlens array and an illumination optical system, or a projection type display in which an image by the display device is projected on a screen by a projection lens The characteristics of a series of optical systems including a light source when constructing the device have not been considered. Therefore, the present invention solves the conventional problems, can effectively utilize all of the light rays from the light source incident on the liquid crystal display element, and significantly improves the aperture ratio, and a liquid crystal display using the same. To provide a device.

[0007]

In the liquid crystal display device of the present invention, of the two transparent substrates in which liquid crystal is injected, the transparent substrate on the side on which the light emitted from the light source is incident is the first flat plate micro panel. The lens array and the flat plate microlens array of the second flat plate microlens array are configured by a substrate in close contact with each other. In each flat-plate microlens array, unit lens portions in an area substantially equal to an area corresponding to each pixel of the liquid crystal pixel array are arranged in the same array as the liquid crystal pixel array. In addition, the unit lens portions between the flat plate microlens arrays have their optical axes aligned with each other to shorten the focal length combined by the respective unit lens portions, and further, the focal point is in the vicinity of the liquid crystal layer and corresponding pixels. As a basic configuration, a unit lens is arranged in the vicinity of the liquid crystal layer so as to coincide with the substantially central portion of the opening.

In the liquid crystal display device of the present invention, of the two transparent substrates with the liquid crystal injected between the illumination system, the transparent substrate on the side on which the light rays emitted from the light source are incident is the first and second flat plates. The microlens array is composed of a closely attached substrate, and in each flat plate microlens array, the unit lens portions in the regions substantially equal to the regions corresponding to each one pixel of the liquid crystal pixel array are arranged in the same array as the liquid crystal pixel array. The unit lens portions of the flat plate microlens array that are in close contact with each other have their optical axes coincident with each other to shorten the focal length synthesized by each unit lens portion, and further, the focal point thereof is in the vicinity of the liquid crystal layer, and
And a liquid crystal display element arranged in the vicinity of the liquid crystal so as to coincide with the substantially central portion of the opening of each corresponding pixel.

[0009]

In the liquid crystal display device of the present invention, the unit lens portion of the microlens array can be arranged in the immediate vicinity of the liquid crystal layer, the unit lens can be made to have a short focal point corresponding to the arrangement position, and the focusing angle of the incident light beam can be widened. . That is, an incident light beam with a large focusing angle from a light source (illumination system) with poor parallelism is effectively guided to the opening, and the non-linearity added as a means for individually controlling the metal wiring of each electrode and each pixel. Brightness is obtained even if the aperture ratio is poor (small) because “vignetting” of incident light does not occur due to blocking by a portion (light-shielding portion) that does not contribute to display, such as a gap around the element or switching element or the pixel electrode, etc. An image information display is obtained. Further, according to the configuration of the present invention, the light emitted from the liquid crystal display element is limited to the effective portion for display, and the opaque portion between the pixels is filled, so that a smooth image information display can be obtained.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. First Example FIG. 1 is a sectional view of a liquid crystal display element 50 according to the first example. The liquid crystal display element 50 is configured by disposing polarizing plates 59 in front of and behind a liquid crystal cell in which liquid crystal 55 is injected between a transparent substrate 57 and a flat plate microlens array A. A pair of first flat plate-shaped microlens arrays 51 are provided on the light incident side of the liquid crystal cell.
And a second flat plate-shaped microlens array 52 (hereinafter referred to as the first
Alternatively, a flat plate microlens array A composed of the second lens arrays 51 and 52) is provided. Each of the lens arrays 51 and 52 is a two-dimensional array in which a plurality of unit lens portions 51a and 52a that refract light are arranged adjacent to each other in the vertical and horizontal directions corresponding to the pixels of the liquid crystal. In the flat plate microlens array A, the unit lens portions 51a and 52a between the first lens array 51 and the second lens array 52 are made to face each other, and the optical axes of the respective lenses are made to coincide with each other to be adhered to the adhesive layer 53. And they are one. A metal thin film, which is usually called a black matrix, is disposed on the integrated flat plate microlens array A to form a light shielding portion 56, and a color filter 58 and a transparent electrode 54 are formed.
Are arranged respectively. The gap between the light shielding portion 56 and the light shielding portion 56 becomes an opening 66. A transparent electrode 54 is provided on the opposite surface side of one transparent substrate 57, and a non-linear element or a switching element 6 as means for individually controlling each pixel.
0 to form a flat plate microlens array A and a transparent substrate 5.
A liquid crystal 55 is enclosed between 7 and 7. In the liquid crystal display element 50 in this embodiment, the pair of polarizing plates 59, the microlens arrays 51 and 52, and the transparent substrate 57 are in close contact with each other, but they may be separated from each other.

Next, a method of manufacturing the flat plate microlens array A in this embodiment will be described. 2 and 3 are explanatory views schematically showing the flat plate microlens array A. First lens array 5 forming the flat microlens array A
The first and second lens arrays 52 are, for example, in a transparent parallel plate glass substrate 510 having a refractive index N ₀ (in this embodiment, a borosilicate optical glass substrate having a thickness t ₁ = about 1 mm is used). Region 5 having a refractive index N different from the substrate refractive index N ₀
15 is a gradient index type flat plate microlens array in which 15 is formed with periodicity. The gradient index microlens array can be formed by, for example, an ion exchange method. In the ion exchange method, a mask layer having a required pattern is formed on a transparent parallel flat plate glass substrate by using, for example, a metal, and when the mask layer is immersed in a molten salt bath, N contained in the glass is contained.
Cations such as a + (sodium ion) and K + (potassium ion) are exchanged with cations such as Tl + (thallium ion) contained in the molten salt through the exposed surface of the glass. The region 515 thus ion-exchanged has a refractive index different from that of the original glass, and the refractive index distribution regions having a function of refracting light become the unit lens portions 51a and 52a.
By forming the microlenses 51 and 52 having the unit lens portions 51a and 52a by this ion exchange method, it is possible to give a lens effect of refracting light to the inside of the transparent parallel flat plate glass substrate 510. When the lens arrays of 1 are integrated, a flat microlens array A having a flat surface can be formed. Also,
In order to manufacture a two-dimensional matrix type gradient index lens corresponding to one pixel of a liquid crystal cell, it is achieved by adjusting (overdiffusing) the shape of the mask layer having a required pattern and the time of ion exchange. It

Next, the planar shape of the unit lens portions 51a and 52a of the flat plate microlens array A will be described with reference to FIG. FIG. 4 is a plan view of a main part showing the shape of the unit lens part 51a (52a) of the flat plate microlens array A of the liquid crystal display element. Usually, the region B corresponding to one pixel of the liquid crystal cell has a square or rectangular shape. Therefore, the shape of the region B is, for example, L _{1 for} the length of one side and L for the length of the other side.
_The rectangle is set to ₂ (L ₁ <L ₂ ). Then, it is assumed that the opening 66 (color filter 58, the transparent electrode 54) and the light shielding portion 56 (black matrix) are provided therein. Here, the unit lens portion 51a of the flat plate microlens array A
_{When 1} is realized in a circular shape as in the conventional technique, the maximum diameter of each adjacent unit lens portion is a circular shape having a diameter L ₁ shown in (a). As a result, of the rays incident on the region B corresponding to one pixel, the rays incident on the outside of the unit lens portion 51a ₁ cannot be effectively used. However, in the process of forming the unit lens portion 51a by the ion exchange method,
As shown in FIG. 4B, it is possible to form a flat plate microlens array having a large area of the unit lens portion 51a ₂ occupying in one pixel of a circular shape having a diameter L ₂ and having a high effective utilization rate of light rays. is there.

That is, the area S occupied by the unit lens portion 51a (hatched portion) of the flat plate microlens array in one pixel
Is configured to satisfy the following equation. (1) When the area B corresponding to one pixel of the liquid crystal cell of _{L 1 <L 2 π (L} 1/2) 2 <S ≦ L 1 · L 2 ‥‥‥ (3) (2) of the liquid crystal cell 1 when the area B corresponding to the pixel is _{L 1 = L 2 π (L} 1/2) 2 <S ≦ L 1 2 ‥‥‥ (4) flat to form a unit lens section 51a so as to satisfy the above equation micro With a lens array, the time required to form (manufacture) a flat microlens array is shortened, which has an effect on productivity such as cost reduction, and a large proportion of one pixel in a unit lens part improves the apparent aperture ratio. That is, a bright liquid crystal display device can be obtained.

Then, the pair of flat plate-shaped microlens arrays 51 and 52 thus formed are brought into close contact with each other, and then the thickness of the flat plate microlens array A is adjusted by polishing (see FIG. 3). Next, a method of adjusting the thickness of the flat plate microlens array A will be described. Unit lens part 51 of two flat plate microlens arrays manufactured by the above manufacturing method
The side where a and 52a are formed is joined and adhered by an ultraviolet curable adhesive 53 which is colorless and transparent and has excellent heat resistance. Then, the thickness of the substrate on the liquid crystal side is set to two unit lens parts 51a,
The thickness equal to the focal length combined at 52a, in this embodiment, the thickness of the second microlens is t ₂ = about 2
Polish to 00 μm. Then, the thin second lens array 52 is disposed on the liquid crystal cell side.

The operation of the flat plate microlens array A thus constructed will be described. FIG. 5 is a principle explanatory view for explaining the flat plate microlens array A of the present embodiment, and FIG. 5A shows the focal length of a unit lens when the flat plate microlens array is composed of one sheet, (B) shows the focal length of the unit lens when it is composed of two pieces. That is, with a single unit lens, the focal length f ₁ can be reduced to a certain extent. On the other hand, when two flat plate microlens arrays are used as in this embodiment (see b), the combined focal length f ₂ is obtained by the equation (5). 1 / f ₂ = 1 / f ₁ + 1 / f ₁ (5) As shown in the above equation, when two unit lenses are combined, one unit lens is used. Focal length f ₂ is 1 /
It becomes possible to shorten the focus to 2. As described above, the flat-plate microlens array A adjusts the thickness of the substrate of the microlens array so that the unit lens portions 51a,
52a can be arranged very close to the liquid crystal surface, and at the same time, the unit lenses 51a and 52a corresponding to the arrangement positions can be made to have a short focus.

Next, a case in which a flat plate microlens array is externally mounted on a transparent substrate having a thickness of 1.1 mm to form a liquid crystal display element as in the conventional case, and the flat plate microlens array A of this embodiment is used. When the liquid crystal display element was configured by using the liquid crystal display element with the same pixel size, the focal length of the unit lens and the converging angle θ of the incident light that can be condensed were measured. The result is shown in the graph of FIG. The light source used was an illumination system in which a reflector was attached to a metal halide lamp with an arc length of 3 mm. In this graph, the horizontal axis indicates the focal length f of the lens, and the vertical axis indicates the angle θ of the incident light ray with respect to the optical axis of the lens. Here, the value of a conventional liquid crystal display element in which a flat plate microlens array is externally mounted on a transparent substrate having a thickness of 1.1 mm is indicated by 15, and the flat plate microlens array A of this embodiment is used to form a liquid crystal display element. The value when configured is shown at 50. From this result, in the liquid crystal display element 50 according to the present embodiment, the distance from the unit lens portion to the liquid crystal surface and the focal length f associated therewith can be made significantly shorter than the value 15 of the structure externally mounted on the transparent substrate. Moreover, it can be seen that the converging angle θ of the incident light that can be condensed is expanded by about 4 times, and even if a light source with poor parallelism is used, the light can be effectively condensed at the opening.

Second Embodiment FIG. 7 is a cross-sectional view of an essential part of a liquid crystal display device 500 according to a second embodiment of the present invention. The same components as those in the first embodiment are designated by the same reference numerals and their detailed description will be given. Omit it. The feature of this embodiment is that the liquid crystal display element 500 is configured by changing the substrate material of the two flat plate-shaped microlens arrays 501 and 502.
In a normal liquid crystal display element, the substrate material of the transparent substrate 57 on the opposite side is different between when an amorphous thin film transistor is used for the switching element 80 and when a polysilicon thin film transistor is used. That is, borosilicate optical glass is used when an amorphous thin film transistor is used, and quartz glass is used when a polysilicon thin film transistor is used. There is no problem if borosilicate optical glass substrates are used for the two flat-plate microlens arrays and amorphous thin film transistors are used as switching elements. However, if polysilicon thin film transistors are used, the coefficient of thermal expansion between the substrates is different, and Problems such as misalignment occur. Therefore, when a polysilicon thin film transistor is used, the substrate material of the flat plate microlens array 501, which has a thick substrate thickness, of the two flat plate-shaped microlens arrays 501 and 502 is the same as the substrate material of the transparent substrate 57 on the opposite side. To do. With this configuration, it is possible to eliminate problems such as pixel shift without deteriorating the light condensing performance of the lens.

Third Embodiment FIG. 8 is a sectional view of an essential part of a liquid crystal display element 550 according to a third embodiment of the present invention. The same components as those in the previous embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. To do. The feature of this embodiment is 2
The flat plate microlens arrays 551 and 552 have the same substrate thickness. Further, a glass substrate 555 is closely attached to the light incident side with an adhesive layer 533. When there is a difference in the thickness of the substrate, the substrate tends to warp slightly. In the first and second embodiments, there is no problem because the size of the liquid crystal display element is about 1 inch to 3 inches, which is small. However, when the size of the liquid crystal display element is further increased, The warp of the substrate becomes a problem. In order to prevent warpage, the substrate thicknesses of the two flat plate microlens arrays may be made equal. Due to the above facts, this liquid crystal display element 550 is composed of two flat plate microlens arrays 5.
By making the substrate thicknesses of 51 and 552 equal, warpage can be prevented from occurring, and a large-sized liquid crystal display device can be manufactured. It should be understood that the material of the glass substrate 555 should be the same as the material of the transparent substrate 57 on the opposite side, as in the previous embodiment.

Fourth Embodiment This embodiment shows a liquid crystal display device using this liquid crystal display element as a light valve. FIG. 9 is a sectional view showing the principle configuration of a liquid crystal display device using the liquid crystal display element according to the present invention as a light valve, and FIG. 9 (a) is a sectional view showing the principle configuration of a liquid crystal display device having an illumination system including a light source. b) is a sectional view of the principle configuration of a projection type liquid crystal display device having an illumination system including a light source and a projection system.

In FIG. 9A, a liquid crystal display device is a light source 10 such as a metal halide lamp or a halogen lamp.
0 (white light source), the concave mirror 110, and the condenser lens group 13
0 and a liquid crystal display element 150 as a light valve. The light emitted from the light source 100 that emits white light is
For example, the light is reflected by the reflecting mirror of the concave mirror 110, or a part of the light is not reflected by the reflecting mirror and is incident on the liquid crystal display element 150 after passing through the condenser lens group 130. In the liquid crystal display element 150, the incident light is effectively guided to the pixel electrodes (openings) by the action of the flat plate microlens array, and the image on the liquid crystal surface is projected on the diffusion plate 170. At this time, the projected image of the diffusion plate 170 provides bright image information while avoiding the loss of the light utilization efficiency due to the light shielding portion. Further, as a drive circuit of the liquid crystal display element 150, for example, a video input input from a laser disk, a VTR or the like is processed by a video chroma processing circuit 71, and an RGB output circuit 72 is provided.
Entered in. In the RGB output circuit 72, the video signals corresponding to R, G, and B and the liquid crystal display element 150 are AC-driven, so that the polarities are inverted every vertical period and input to the electrodes of the liquid crystal display element 150 via the X driver 73. . Video chroma processing circuit 71, RGB output circuit 72, X driver 7
3 and the Y driver 76 are synchronized by the synchronization processing circuit 74 and the controller 75.

In the projection type liquid crystal display device shown in FIG. 9B, light is emitted from the light source 100 and is incident on the liquid crystal display element 150.
The image information after passing is enlarged by the projection lens 190 and enlarged and projected on the screen 200. Screen 2
With the projection image of 00, bright image information can be obtained while avoiding the loss of light utilization efficiency due to the light shielding unit.

Fifth Embodiment This embodiment shows another example of a liquid crystal display device using the liquid crystal display element according to the present invention as a light valve (see FIG. 10). FIG. 10 is a sectional view showing the principle configuration of the projection type liquid crystal display device according to this embodiment. The liquid crystal display element according to the present invention has three primary colors of R (red), G (green) and B (blue). Correspondingly, a three-plate projection type liquid crystal display device using a total of three sheets is shown. A light beam emitted from a light source 300 using metal halide, xenon, halogen, etc. is directly or reflected by a concave mirror 310, passes through an infrared cut filter 320 that reflects heat rays and allows visible light to pass, and enters a condenser lens group 330. After that, the light is emitted so as to be substantially parallel to the optical axis of the light beam. Then, the light ray is reflected by the B (blue) reflection dichroic mirror 340a arranged at an angle of 45 ° with respect to the optical axis of the light ray, and the R (red) and G (green) light is reflected. To Penetrate.

The reflected B ray is incident on the liquid crystal display element 350 after its optical path is bent by the total reflection mirror 345. On the other hand, B reflection dichroic mirror 340a
The R and G rays that have passed through are 45 ° to the optical axis of the ray.
G-reflecting dichroic mirror 340 arranged at an angle of
G rays are incident on b and are reflected by the G reflection dichroic mirror 340b, and R rays are transmitted.

The reflected G ray is the liquid crystal display element 3 as it is.
It is incident on 50. On the other hand, the R ray that has passed through the G reflection dichroic mirror 340 b is incident on the liquid crystal display element 350 with its optical path bent by the total reflection mirror 345. Further, an image corresponding to each of R, G, and B displayed on the liquid crystal surface of each liquid crystal display element 350 has a B reflection surface 361 and an R reflection surface 363, and the reflection surface is a light beam of each color. The dichroic prism 365 configured so as to form an angle of 45 ° with respect to the axis synthesizes the synthesized image with the projection lens 370 to obtain a magnified real image on the screen 390.

Further, as a drive circuit of the liquid crystal display element in this embodiment, for example, there is a circuit shown in the drawing. That is, a video input from a laser disk, a VTR, etc. is processed by the video / chroma processing circuit 81,
Input to the output circuit 82 corresponding to each color of R, G, B. R
In the GB output circuit 82, since the video signal corresponding to each color and the liquid crystal display element are AC-driven, the polarities are inverted every vertical period and input to the liquid crystal display element 350 via the X driver 83 corresponding to each color. The above video / chroma processing circuit 8
1, the output circuit 82 corresponding to each color, the X driver 83, and the Y driver 86 are synchronized by the synchronization processing circuit 84 and the controller 85 corresponding to each color. In addition,
It goes without saying that the liquid crystal display element 310 used in this embodiment does not require a color filter.

[0026]

Since the liquid crystal display device of the present invention can widen the incident angle of incident light, even if the aperture ratio, which is one of the main factors that deteriorates the light utilization efficiency of the liquid crystal display device, is poor (small) in the related art. However, it is hardly affected by the influence, the apparent aperture ratio is increased, and “vignetting” of the light beam due to being blocked by a portion that does not contribute to the display is not generated, and the light utilization efficiency is improved. That is, it is possible to provide a liquid crystal display device that can obtain bright image information. Further, the liquid crystal display device of the present invention can secure a high light-condensing effect even when using a normal light source (illumination system) having poor parallelism, and can effectively use light rays from the light source. Further, the emitted light from the liquid crystal display element is limited to the effective portion for display, and the opaque portion between pixels is eliminated, so that bright and smooth image information display can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is an external perspective view schematically showing a flat plate microlens array.

FIG. 3 is a partial cross-sectional view schematically showing a flat plate microlens array.

FIG. 4 is a main part plan view showing the shape of a flat plate microlens array.

FIG. 5 is a diagram illustrating the principle of the effect of the flat plate microlens array.

FIG. 6 is a characteristic graph of a flat plate microlens array.

FIG. 7 is a cross-sectional view of essential parts of a liquid crystal display element according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view of essential parts of a liquid crystal display element according to a third embodiment of the present invention.

FIG. 9 is a structural explanatory view of a liquid crystal display device and a projection type liquid crystal display device of the present invention.

FIG. 10 is a structural explanatory view of another embodiment of the liquid crystal display device of the present invention.

FIG. 11 is a cross-sectional explanatory diagram of a conventional liquid crystal display element.

[Explanation of symbols]

 50 Liquid Crystal Display Element 51 First Lens Array 51a Unit Lens Section 52 Second Lens Array 52a Unit Lens Section 53 Adhesive Layer 54 Transparent Electrode 55 Liquid Crystal 56 Light Shielding Section 57 Transparent Substrate 58 Color Filter 60 Switching Element A Flat Plate Micro Lens Array

Claims (6)

[Claims] 1. In a transmissive liquid crystal display device in which liquid crystal is injected between a pair of transparent substrates to display image information by the electro-optical effect of the liquid crystal, the transparent substrate on the side on which a light beam emitted from a light source is incident, comprising a first planar microlens array and the second planar microlens array the unit lenses of the refractive index N ₀ as different refractive index N is arranged in the same sequence as the liquid crystal of the pixel array in the substrate having a refractive index N _0, The unit lens of each flat plate microlens array has a region substantially equal to the region corresponding to each pixel of the liquid crystal pixel array, and the first flat plate microlens array and the second flat plate microlens array are of the unit lens unit. A liquid crystal display device in which optical axes are aligned and the focal point is aligned near the liquid crystal layer and is aligned in the substantially central portion of the opening of each corresponding pixel and bonded. 2. In the unit lens portion of the flat plate microlens array, when the region corresponding to one pixel of the liquid crystal has a rectangular shape with one side L ₁ and the other side L ₂ , L ₁ <L ₂ (L ^_1/2) 2 <when _{S ≦ L 1 · L 2 L} 1 = L 2 π (L 1/2) 2 <S ≦ L 1 2 However, S: area of the region which acts as a unit lens section ( 2. An area satisfying a lens aperture).
The liquid crystal display element described. 3. The liquid crystal display device according to claim 1, wherein the unit lens portions of the first flat plate microlens array and the second flat plate lens array which are joined are arranged in the vicinity of the liquid crystal layer. 4. A two-dimensional matrix type refractive index distribution type planar microlens array in which unit lens portions having a refractive index different from that of the substrate are periodically formed in each flat plate microlens array. Liquid crystal display element. 5. A liquid crystal display device comprising at least an illumination optical system and a liquid crystal display device, wherein the liquid crystal display device of the liquid crystal display device comprises the liquid crystal display device according to claim 1, 2, 3, or 4. Liquid crystal display device. 6. A projection-type liquid crystal display device comprising at least an illumination optical system, a liquid crystal display element, and a projection optical system, wherein the liquid crystal display element of the liquid crystal display device is the liquid crystal according to claim 1, 2, 3, or 4. A projection type liquid crystal display device using a display element.