JPH1184337A - Liquid crystal device and projection display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constitution capable of enhancing an effective opening ratio efficiently and also capable of making a device thinner in a liquid crystal display device in which a microlens array is formed. SOLUTION: In a liquid crystal device 100, a second substrate 120 in one pair of substrates 110, 120 holding a liquid crystal device 130 is provided with a microlens substrate 121 in which a microlens array 122 is formed on a light emitting surface 126. A light emitting surface 125 of the second substrate 120 is flattened by a resin layer 124 formed on the surface of the microlens array 122 to face a liquid crystal layer 130 through the resin layer 124. By this constitution, the effective opening ratio of the device can be enhanced by collecting lights efficiently to pixel openings 180 and also the miniaturizing and the thinning of the device can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a liquid crystal device in which an effective aperture ratio is improved by using a microlens array, and a projection display device incorporating the liquid crystal device.

[0002]

2. Description of the Related Art In recent years, attention has been paid to a projection type display device using a liquid crystal device. It is very difficult to increase the screen size of a direct-view type liquid crystal device. This is because a large image of high quality can be easily obtained by projecting the image on a screen or the like. When a liquid crystal device is used in a projection display device, it is necessary to increase the number of pixels so that the image quality is not noticeable even at a high magnification.
As the number of pixels increases, the area of a portion other than the pixels in the liquid crystal device also increases accordingly. This tendency is particularly strong in an active matrix type liquid crystal device. Portions other than the pixels are shielded from light by a light-shielding layer generally called a black matrix, and the area of the portions (openings) not shielded from light is reduced. As a result, the amount of light emitted from the miniaturized liquid crystal device becomes very small, and the displayed image becomes dark.

In order to prevent a decrease in the amount of light due to the refinement of the liquid crystal device, a liquid crystal device having a structure in which a microlens is attached to the liquid crystal device and light is condensed on the opening of each pixel by the microlens has been proposed. ing.

FIG. 3 shows a schematic sectional structure of the liquid crystal device. As shown in this figure, the liquid crystal device 200 has a counter substrate 210 having a pair of glass substrates 211 and 212 bonded to each other by an adhesive 230, and the counter substrate 210 is transparent via a liquid crystal layer 130. Substrate 22
0. Counter substrate 210
The surface on the liquid crystal layer side of the glass substrate 211 outside the
A microlens array 213 composed of a plurality of microlenses corresponding to each pixel is formed.

According to such a liquid crystal device 200, light components normally blocked by the black matrix 170 can be condensed on the corresponding pixel openings 180 by the microlens array 213. The aperture ratio can be improved, and a bright display image can be obtained.

[0006]

As described above, the liquid crystal device is required to be small and thin while being required to have high brightness and high definition of an image. If a microlens array is formed, it is possible to achieve brightness and high definition of an image, but it is not possible to achieve miniaturization and thinning because the thickness of the counter substrate increases.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a liquid crystal device having a microlens array formed thereon, by efficiently reducing the thickness of the device and improving the effective aperture ratio, thereby achieving a small and sufficiently bright display. It is to provide a liquid crystal device capable of obtaining an image. Another object of the present invention is to provide a projection display device incorporating the liquid crystal device.

[0008]

In order to solve the above-mentioned problems, a liquid crystal device according to the present invention comprises a plurality of pixels arranged in a matrix and has a liquid crystal layer sandwiched between a pair of substrates. The one substrate includes a microlens substrate in which a microlens array is formed on a surface on the liquid crystal layer side, and the surface on the liquid crystal layer side of the one substrate is on a surface of the microlens array. It is characterized by being flattened by the formed resin layer.

In the liquid crystal device according to the present invention, the surface of the microlens array is flattened by the resin layer, so that the microlens array and the liquid crystal layer face each other via the resin layer. Thus, the substrate (glass substrate) on the liquid crystal layer side of the conventional liquid crystal device (see FIG. 3) can be omitted. The fact that the microlens array is formed causes an increase in the thickness of the device, but the thickness of the glass substrate is much larger than the thickness of the microlens array, so that the glass substrate is removed. Therefore, the size and thickness of the liquid crystal device having the microlens array formed thereon can be reduced. Further, since the distance from the microlens array to the liquid crystal layer can be very short, the diameter of the light spot at the pixel opening can be reduced by using a microlens having a short focal length corresponding to the distance. Therefore, light can be efficiently guided to the pixel openings without being blocked by the black matrix. Therefore, a sufficiently bright display image can be obtained by efficiently increasing the effective aperture ratio. Further, since the thickness of the resin layer can be easily adjusted by polishing or the like, the distance from the microlens array to the liquid crystal layer can be easily adjusted to a desired length according to the focal length of the microlens.

The resin layer can be made of a resin such as a photo-curing or thermosetting epoxy or acrylic resin.
In general, the curing time of a photocurable resin is shorter than that of a thermosetting resin. Therefore, from the viewpoint of mass productivity, it is desirable to use a photocurable resin. Further, if a material having a thermal expansion coefficient close to that of glass generally used for a substrate of a liquid crystal device is selected, the problem of peeling or cracking of the resin due to heat generation due to light irradiation does not occur.

In the present invention, if an antireflection film is formed on at least the surface of the microlens substrate opposite to the liquid crystal layer, light can be prevented from being reflected on that surface, so that the light can be used efficiently. It is effective in raising.

The liquid crystal device of the present invention is a projection type display device comprising: a modulating means for modulating a light beam emitted from a light source; and a projecting means for enlarging and projecting the light beam modulated by the modulating means on a projection surface. It can be used as a modulation means. As described above, in the liquid crystal device of the present invention, although the microlens array is formed, the device is efficiently reduced in size and thickness and the effective aperture ratio is improved. The projection display device provided is small and can project a bright high-quality image.

In particular, a color separating means for separating a light beam emitted from a light source into light beams of respective colors, a plurality of modulating means for modulating the light beams of respective colors separated by the color separating means, and a modulating means for modulating each of the light beams. The liquid crystal device of the present invention is suitable as a modulating means of a projection display device having a color synthesizing means for synthesizing the luminous fluxes of the respective colors, and a projection means for enlarging and projecting the luminous flux synthesized by the color synthesizing means on a projection surface. ing.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(Liquid Crystal Device) An example of a liquid crystal device to which the present invention is applied will be described below with reference to the drawings. 1A and 1B show a schematic configuration of the liquid crystal device using a cross-sectional view and a perspective view. As shown in FIGS. 1 (A) and (B),
The liquid crystal device 100 of the present example has a first substrate 110 which is a glass substrate made of quartz glass or the like, and a second substrate 110 which is disposed so as to face the first substrate 110 with a sealant 140 interposed therebetween.
Substrates 120, and a liquid crystal layer 130 between these substrates.
Is enclosed. Liquid crystal device 100 of the present example
Are polarizing plates 210 and 20 on the side of the light incident surface and the light exit surface.
It is used as a light valve of a projection display device in a form where 0 is arranged.

The first substrate 110 is a glass substrate made of quartz glass or the like, and has source lines 151 and gate lines 152 formed in a lattice on the surface thereof. Source line 1
The thin film transistor (TF) is connected to the gate line 51 and the gate line 152.
T) 153 is connected. Thin film transistor 153
, A transparent pixel electrode 154 is connected in series.

The second substrate 120 includes a microlens substrate 121 made of crystallized glass made of quartz, neoceram, or the like. A surface (light emitting surface) 126 of the microlens substrate 121 on the side of the liquid crystal layer 130 is provided. Has a microlens array 122 formed therein.

The micro lens array 122 is composed of a plurality of micro lenses 123. Each micro lens 123 is a convex lens, and is arranged in a matrix corresponding to each pixel of the first substrate 110. Each microlens 123 is given an optical characteristic so that light passing through a resin layer 124 described later is focused on the pixel opening 180. Therefore, the macro lens array 1
Almost all of the light incident on the pixel apertures 180 is condensed by the microlens array 122 so as to correspond to each pixel opening 180.
, And the amount of light passing through the pixel opening 180 can be increased.

The microlens array 122 can be formed on the microlens substrate 121 by, for example, patterning the microlens substrate 121 to obtain a desired microlens array 122 and then forming the microlens array 121 by photolithography. Also, the microlens array 122 can be formed by cutting a material by a machining method. Further, it can be formed by an evaporation method or the like. In this case, a concave portion similar to the contour shape of the microlens 123 is formed on the substrate, a predetermined substance is vapor-deposited until the concave portion is filled, and then the entire thickness (the microlens substrate 121 and the May be adjusted by polishing or the like. Note that the micro lens array 122 is
Of course, it may be formed from a material different from the above.

In the liquid crystal device 100 of the present embodiment, a resin layer 124 is formed on the surface of the microlens array 122 and is flattened. This resin layer 124 can be formed by forming an adhesive on the surface of the microlens array 122 after forming the microlens array 122, flattening and hardening the surface. At this time, it is preferable to form the resin layer 124 with a thickness that does not cause unevenness due to the microlens array 122.

For the resin layer 124, a photo-curing adhesive that is cured by light such as ultraviolet light or a thermosetting adhesive that is cured by heat can be used. It should be noted that the photo-curable adhesive can be cured in a shorter time than the thermo-curable adhesive, so when the curing time is taken into consideration, the photo-curable epoxy, acrylic, silicone, etc. It is more advantageous to use an adhesive. Since the silicon adhesive has high elasticity, even if a thermal stress is generated due to a difference in thermal expansion coefficient from glass, there is an advantage that the stress can be absorbed. Further, if a material having a thermal expansion coefficient close to that of glass generally used for a substrate of a liquid crystal device is selected, the problem of peeling or cracking of the resin due to heat generation due to light irradiation does not occur.

Note that the refractive index of the resin layer 124 needs to be smaller than the refractive index of the microlens substrate 122.

In order to form a flat resin layer 124,
For example, an adhesive having relatively high fluidity may be used. The adhesive may be applied to the microlens array 122 by a so-called spin coating method in which the adhesive is applied while rotating the microlens substrate 121 at high speed.

As still another method, first, an adhesive is applied to the surface of the microlens substrate 121. Next, a flattening member that has been subjected to a surface treatment so that the adhesive does not adhere to the surface flattened by polishing or the like is placed on the adhesive. Next, the surface of the adhesive is flattened by rubbing the flattening member with the microlens substrate 121. Finally,
When the adhesive is cured and the flattening member is removed, a flattened resin layer 124 is formed. The flattening member used at this time is desirably formed of a material having a light transmitting property. When such a flattening member is used, when a photocurable adhesive is used, light irradiation is performed. The area can be increased, the curing time can be shortened, and this is advantageous in terms of mass productivity.

Resin layer 124 of microlens substrate 121
A black matrix 170 made of metal chromium or the like is formed on the surface of the first substrate 110 by vapor deposition or the like in order to prevent the switching elements formed on the first substrate 110 from being irradiated with light. This black matrix 170
Thus, curing such as prevention of light deterioration of the switching element and prevention of light leakage between pixels can be obtained, and a bright and high-contrast display image can be obtained. Also, the resin layer 124
The counter electrode 160 is formed on the surface of the substrate.

In the liquid crystal device 100 thus configured, the light L incident on the microlens substrate 121 from the counter electrode side is refracted by each microlens 123 of the microlens array 122 and passes through the resin layer 124 to the corresponding pixel. The light is focused on the opening 180. In the liquid crystal device 100 of the present example,
The resin layer 124 formed on the surface of the microlens array 122 faces the liquid crystal layer 130, and has a configuration in which the glass substrate 212 in the conventional liquid crystal device 200 described with reference to FIG.

Therefore, only the resin layer 124 is interposed between the microlens array 122 and the liquid crystal layer 130, and the distance from the microlens array 122 to the liquid crystal layer 130 can be extremely reduced. Therefore, the micro lens 123 having a short focal length corresponding to the distance can be used, and a minute light spot can be formed in the pixel opening 180. As a result, the pixel openings 180 are not blocked by the black matrix 170.
Light can be collected efficiently, and the effective aperture ratio can be increased to obtain a sufficiently bright display image.

Although the formation of the microlens array 122 causes an increase in the thickness of the device, the glass substrate having a thickness much larger than the thickness of the microlens array 122 has been removed. Therefore, the size and thickness of the liquid crystal device on which the microlens array 122 is formed can be reduced.

In the liquid crystal device 100 of this embodiment, the microlens array 122 is formed integrally with the microlens substrate 121.
May be formed, and the microlens array 122 may be bonded to the microlens substrate 121 later. Further, in order to improve the light use efficiency, the micro lens array 12
Preferably, an anti-reflection film is formed on the surface of No. 2.

(Projection Display Device) An example of a projection display device provided with a liquid crystal device to which the present invention is applied will be described. The projection display apparatus of this example separates a white light beam emitted from the light source lamp unit into three primary color light beams of red (R), green (G), and blue (B), and converts each of these color light beams as a light valve. This is a type in which the light is modulated in accordance with image information through a liquid crystal device to which the present invention is applied, and the luminous flux of each color after the modulation is recombined and enlarged and displayed on a screen via a projection optical system.

FIG. 2 shows a schematic configuration of an optical system incorporated in the projection display device 1 of this embodiment. The optical system of the projection display device 1 of the present example includes a light source lamp 80 as a component of the light source lamp unit 8 and a first lens plate 921 and a second lens plate 92 having a plurality of rectangular lenses.
A uniform illumination optical system 923 having 2 is employed. Then, the projection display apparatus 1 uses the uniform illumination optical system 923.
Of the light beam W emitted from the red (R), green (G), blue (B)
And a color separation optical system 924 for separating light beams of respective colors R, G, B
Liquid crystal devices 100R, 100G, 100
B, a dichroic prism 10 as a color synthesizing optical system for re-synthesizing the modulated color light beam, and a projection lens unit 6 for enlarging and projecting the synthesized light beam on the surface of the screen 1000. Further, each color light flux R, G,
B, the liquid crystal light valve 10 corresponding to the blue luminous flux B
It has a light guide system 927 for guiding to 0B.

The light emitted from the light source lamp 80 enters the uniform illumination optical system 923 and passes through the first lens plate 921 onto the entrance surface of each rectangular lens forming the second lens plate 922. Each is projected as a secondary light source image, and the liquid crystal devices 100R, 100G, and 100B, which are objects to be illuminated, are illuminated using the light emitted from the second lens plate 922.

The uniform illumination optical system 923 includes a reflection mirror 931 so that the optical axis 1a of the light emitted from the uniform illumination optical system 923 is bent at a right angle toward the front of the apparatus. First, with the reflection mirror 931 interposed therebetween,
The second lens plates 921 and 922 are arranged to be orthogonal.

The color separation optical system 924 includes a blue-green reflecting dichroic mirror 941 and a green reflecting dichroic mirror 9.
42 and a reflection mirror 943. The luminous flux W is
First, in the blue-green reflecting dichroic mirror 941,
The blue luminous flux B and the green luminous flux G contained therein are reflected at substantially right angles, and travel toward the green reflection dichroic mirror 942.

The red light beam R passes through the blue-green reflecting dichroic mirror 941, is reflected at a substantially right angle by the rear reflecting mirror 943, and is emitted from the emitting portion 944 of the red light beam R to the dichroic prism 10. The blue and green light fluxes B and G reflected by the blue-green reflection dichroic mirror 941 are reflected by the green reflection dichroic mirror 942 so that only the green light flux G is reflected substantially at right angles, and the green light flux G exits from the emission portion 945 of the dichroic prism 10. Emitted to the side. This green reflective dichroic mirror 94
The blue luminous flux B that has passed through the light-emitting device 2 is emitted from the blue light
From the light guide system 927. In this example, the distances from the light emitting portion of the light beam W of the uniform illumination optical system to the light emitting portions 944, 945, and 946 of the color light beams in the color separation optical system 924 are all set to be equal.

The red and green luminous flux R of the color separation optical system 942,
Condensing lenses 951 and 952 are arranged on the emission sides of the G emission sections 944 and 945, respectively. Therefore,
The red and green luminous fluxes R and G emitted from the respective emission sections are incident on these condenser lenses 951 and 952 and are parallelized.

The parallelized red and green luminous fluxes R and G enter the liquid crystal devices 100R and 100G and are modulated to add image information corresponding to each color light. That is, the switching of these liquid crystal devices is controlled by driving means (not shown) in accordance with image information.
The modulation of each color light passing therethrough is performed. As such a driving means, a known means can be used as it is.
On the other hand, the blue luminous flux B is guided to the corresponding liquid crystal device 100B via the light guide system 927, where it is similarly modulated according to image information.

The light guide system 927 includes a light emitting portion 94 for the blue light flux B.
6, a condenser lens 954 disposed on the exit side, an incident side reflection mirror 971, an exit side reflection mirror 972, an intermediate lens 973 disposed between these reflection mirrors, and disposed on the near side of the liquid crystal device 100B. And a condenser lens 953. The optical path length of each color light beam, that is, the distance from the light source lamp 80 to each liquid crystal panel, is the longest for the blue light beam B, and therefore, the light amount loss of this light beam is the largest. However, by interposing the light guide system 927, the light amount loss can be suppressed.

Next, each of the liquid crystal devices 100R, 100G, 1
Each color light flux R, G, B modulated through 00B is recombined by the dichroic prism 10. The color image synthesized by the dichroic prism 10 is
The image is enlarged and projected on the surface of the screen 1000 at a predetermined position via the projection lens unit 6.

The projection display device 1 thus configured
Are liquid crystal devices 100R, 100G, 1
00B. Liquid crystal devices 100R, 100G, 1
Since the effective aperture ratio of 00B is increased as described above, a bright and high-quality image can be projected by the projection display apparatus 1 including the liquid crystal devices 100R, 100G, and 100B. In addition, the liquid crystal devices 100R, 10R
0G and 100B can be made smaller and thinner than the conventional liquid crystal device despite the formation of the microlens array 122.
The projection display device 1 provided with R, 100G, and 100B can provide a compact projection display device.

[Other Embodiments] The above-described projection display device 1 is a front projection display device that performs projection from the side where the projection surface is observed, but the liquid crystal device of the present invention employs a projection surface. The present invention can also be applied to a rear projection display device that performs projection from a direction opposite to the side to be observed.

The above-described liquid crystal device 100 can be used as a direct-view type liquid crystal device.

[0042]

As described above, in the liquid crystal device of the present invention, the surface of the microlens array is flattened by the resin layer so that the microlens array and the liquid crystal layer face each other through the resin layer. Like that. Therefore,
Compared with the conventional liquid crystal device, a substrate (glass substrate) thicker than the microlens array is omitted,
The size and thickness of the liquid crystal device on which the microlens array is formed can be reduced. Further, since the distance from the microlens array to the liquid crystal layer can be shortened, the focal length of the microlens can be shortened according to the distance, and a minute light spot can be formed in the pixel opening. Therefore, light can be efficiently guided to the pixel openings without being blocked by the black matrix, so that the effective aperture ratio is increased and a sufficiently bright display image can be obtained.

[Brief description of the drawings]

FIG. 1A is a schematic cross-sectional configuration diagram of a liquid crystal device to which the present invention is applied, and FIG. 1B is a perspective view of the liquid crystal device.

FIG. 2 is a schematic configuration diagram showing an optical system of a projection display device in which the liquid crystal device shown in FIG. 1 is incorporated.

FIG. 3 is a schematic cross-sectional configuration diagram of a conventional liquid crystal device.

[Explanation of symbols]

 Reference Signs List 1 projection display device 6 projection lens unit 80 light source lamp 10 dichroic prism 100, 100R, 100G, 100B liquid crystal device 110 first substrate 120 second substrate 121 microlens substrate 122 microlens array 123 microlens 124 resin layer 125th Light emitting surface of substrate 2 126 Light emitting surface of microlens substrate 130 Liquid crystal layer 140 Sealant 151 Source line 152 Gate line 153 Thin film transistor (TFT) 154 Pixel electrode 160 Counter electrode 170 Black matrix 180 Pixel aperture 210, 220 Polarizer 921, 922 Integrator lens 923 Uniform illumination optical system 924 Color separation optical system 1000 Projection surface

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G02F 1/1335 530 G09F 9/00 327Z G09F 9/00 327 360D 360 H04N 5/74 K H04N 5/74 9/31 C 9/31 G02B 1 / 10 A

Claims (5)

[Claims] 1. A liquid crystal device comprising a plurality of pixels arranged in a matrix and having a liquid crystal layer sandwiched between a pair of substrates, wherein one of the substrates has a microlens array on a surface on the liquid crystal layer side. A liquid crystal device, comprising: a formed microlens substrate; and a surface of the one substrate on the liquid crystal layer side is planarized by a resin layer formed on a surface of the microlens array. 2. The liquid crystal device according to claim 1, wherein the resin layer is a photocurable resin. 3. The liquid crystal device according to claim 1, wherein an antireflection film is formed on at least a surface of the microlens substrate opposite to the liquid crystal layer. 4. A modulating means for modulating a light beam emitted from a light source, and a projecting means for enlarging and projecting the light beam modulated by the modulating means on a projection surface, wherein the modulating means comprises:
A projection type display device, which is the liquid crystal device according to claim 1. 5. The color separation device according to claim 4, wherein the light beam emitted from the light source is separated into light beams of respective colors, and the plurality of modulation devices that modulate the light beams of respective colors separated by the color separation device. A color synthesizing unit for synthesizing a light beam of each color modulated by each of the modulating units, wherein the light beam synthesized by the color synthesizing unit is enlarged and projected on a projection surface by the projection unit. Type display device.