JPH06118370A - Light valve device and display device using device concerned - Google Patents

Abstract

PURPOSE:To provide a projection type display device which can display a projection image being bright and having a high picture quality. CONSTITUTION:A first lens array means 71, a second lens array means 72, and a light valve 73 are arranged in order from an incident light side, a focal distance of a positive lens element of a first lens array means 71 is shorter than a focal distance of each positive lens element of a second lens array means 72, and each positive lens element of a second lens array means 72 forms a real image corresponding to a virtual object on a focus of each positive lens element of a first lens array means 71, in each picture element of the light valve 73. By a first lens array means 71, plural minute light sources corresponding to a light source are formed, and in each positive lens element of a second lens array means 72, an emitted light from plural minute light sources is made incident and can be allowed to be made incident on a picture element of the light valve 73, therefore, since light which is made incident on an opening part of the light valve 73 is increased without thinning and incident side glass substrate of the light valve 73, a bright projection image is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light valve device, a projection type display device and a viewfinder device using the light valve device.

[0002]

2. Description of the Related Art In order to obtain a large screen image, a method of forming an optical image according to an image signal on a light valve, irradiating the optical image with light, and enlarging and projecting it onto a screen by a projection lens is well known. Has been. Recently, a projection type display device using a liquid crystal panel as a light valve has been proposed (for example, Japanese Patent Laid-Open Nos. 62-133424 and 2).
No. 250015, etc.), the entire set becomes compact, and therefore, attention has been paid to it.

In order to obtain a high quality projected image, a liquid crystal panel uses a twist nematic (TN) liquid crystal as a liquid crystal material and an active matrix type in which a TFT is provided in each pixel as a switching element. It is becoming mainstream to use three liquid crystal panels for blue.

FIG. 11 shows a conventional configuration example of an optical system of a projection type display device using a liquid crystal panel. The light emitted from the light source 11 enters a color separation optical system composed of the dichroic mirrors 12 and 13 and the plane mirror 14 and is separated into three primary colors of red, green and blue. The primary color lights pass through the field lenses 15, 16 and 17, respectively, and then through the incident side polarization plates 18, 19 and 20, respectively, and the liquid crystal panel 2
It is incident on 1, 22, 23. The optical image formed as a change in optical rotatory power on the liquid crystal panels 21, 22, and 23 in accordance with the video signal is transmitted by the action of the incident side polarization plates 18, 19, 20 and the emission side polarization plates 24, 25, 26. It becomes a changed optical image. The light emitted from the liquid crystal panels 21, 22, 23 is
The light is combined into one light by the color combining optical system including the dichroic mirrors 27 and 28 and the plane mirror 29. The combined light is incident on the projection lens 30, and the optical images on the three liquid crystal panels 21, 22, and 23 are enlarged and projected on the screen by the projection lens 30.

The structure of the TFT liquid crystal panel is shown in FIG. A sealed space is formed by the two glass substrates 41 and 42 and the sealing resin in the peripheral portion, and the TN liquid crystal 43 is sealed inside. A common electrode 44 made of a transparent conductive film is provided on the liquid crystal layer 43 side of the incident side glass substrate 41, and pixel electrodes 45 made of a transparent conductive film are formed in a matrix on the liquid crystal layer 43 side of the emission side glass substrate 42. A TFT 46 is formed near each pixel electrode 45 as a switching element. An alignment film is formed on the common electrode 44 and the pixel electrode 45 to align the TN liquid crystal in a predetermined state. Polarizing plates 47 and 48 are arranged on the entrance side and the exit side of the liquid crystal panel with their absorption axes oriented in a predetermined direction. Intense light is incident on the liquid crystal panel.
In order to prevent this malfunction, a black matrix 49 made of a metal thin film that shields the TFT 46 and the wiring is formed on the liquid crystal layer 43 side of the incident side glass substrate 41. TFT46
When a signal voltage is applied to each pixel via the, the optical activity of the liquid crystal layer of each pixel changes, and the transmittance of each pixel can be controlled by the action of the two polarizing plates 47 and 48. Thus, an image is displayed on the liquid crystal panel as a change in transmittance.

By the way, with the configuration shown in FIG.
The light used by the T liquid crystal panel is the black matrix 4
The brightness of the projected image is proportional to the aperture ratio of the liquid crystal panel (the ratio of the total area of the openings 50 of the black matrix 49 to the total area of the display area) of the liquid crystal panel. If the light incident on the non-opening portion 51 of the black matrix 49 can also be used, the projected image can be brightened and the energy use efficiency can be improved. Therefore, a method has been proposed in which a projection image is brightened by arranging a lens array plate close to the incident side of the liquid crystal panel (for example, JP-A-1-189685 and JP-A-2-262185).
Issue Bulletin).

An example of the construction of a light valve device in which a liquid crystal panel is combined with a lens array plate is shown in FIG. The lens array plate 61 is formed by forming a plurality of positive lens elements 64 in a matrix on the surface of the transparent substrate 62 on the liquid crystal panel 63 side. The lens array plate 61 includes the positive lens element 6
4 and the pixels 50 of the liquid crystal panel 63 are arranged close to each other. The light incident on the lens array plate 61 is
It is converted into focused light by the positive lens element 64 and is incident on the pixel 50. Since the light that enters the non-opening portion 51 of the black matrix 49 enters the opening portion 50, the liquid crystal panel 6
3, the substantial aperture ratio is improved, and the projected image becomes brighter.

[0008]

In order to obtain a high-definition projected image with the configuration shown in FIG. 13, it is preferable to increase the number of pixels of the liquid crystal panel. If the display screen dimensions of the liquid crystal panel are the same, the pixel pitch will be reduced. In this case, the following problems occur.

When a lens array is used, the liquid crystal panel 6
A reduced real image of the light source is formed on 3 pixels 50.
If the size of this real image is larger than the size of the pixel 50,
Although the effective aperture ratio is improved when parallel light is incident,
The projected image does not become bright. In order to reduce the size of the real image of the light source, it is necessary to shorten the focal length of the positive lens element 64 of the lens array plate 61, and it is necessary to make the incident side glass substrate 41 thin. However, if the incident side glass substrate 41 is made thin, it becomes difficult to make the thickness of the liquid crystal layer 43 uniform. Therefore, a method of disposing a lens element inside the incident side glass substrate 41 has been proposed (Japanese Patent Laid-Open No. 2-302726). However, when a gradient index lens array is formed by the ion exchange method, it is necessary to use glass containing alkali ions as a glass substrate, but there is a problem that the characteristics of the TFT deteriorate due to the elution of alkali ions. Also, 2 lens arrays
When forming between two glass substrates, it is necessary to combine materials with different refractive index materials, but it is difficult to make the thickness of the liquid crystal layer uniform in a wide temperature range because of different thermal expansion coefficients. . In any case, it is difficult to display a high quality image on the liquid crystal panel by the method of forming the positive lens element inside the incident side glass substrate. After all, there is a problem that it is difficult to obtain a high-definition and bright projection image.

Next, the video camera needs to be made compact and lightweight in order to improve portability, and it is considered that a liquid crystal panel is used for the viewfinder in order to make the whole compact. In order to make the viewfinder small and lightweight and display a high quality image on the liquid crystal panel, it is necessary to make the display screen of the liquid crystal panel small and increase the number of pixels. That is, it is necessary to reduce the pixel pitch of the liquid crystal panel. Then, since the aperture ratio of the liquid crystal panel becomes small, the displayed image is dark. A bright light source may be used to brighten the display image, but power consumption of the light source is increased, and a problem occurs that continuous use time in one battery charge is shortened.

The present invention provides a projection type display device which displays a bright projected image without thinning the glass substrate even when the pixel pitch of the liquid crystal panel is small, and a viewfinder where the displayed image is bright with low power consumption. With the goal. Moreover, it aims at providing the light valve apparatus for this.

[0012]

A light valve device according to the present invention comprises a light valve having a plurality of pixels arranged in a matrix in a delta arrangement, and a plurality of positive lens elements arranged in a matrix similar to the pixel arrangement of the light valve. 1 lens array means, and a second lens array means in which a plurality of positive lens elements are arranged in a matrix similar to the pixel arrangement of the light valve, and the second lens array means is provided on the incident side of the light valve. The first lens array means is disposed on the incident side of the second lens array means, and the focal length of each positive lens element of the first lens array means is the same as that of the second lens array means. Equal to or shorter than the focal length of the positive lens element, each positive lens element of the second lens array means is the first lens array means. Real images of virtual objects on the focal points of the plurality of positive lens elements are formed on the corresponding pixels of the light valve, and the optical axis of each positive lens element of the first lens array means is the second lens array. The means is arranged so as to pass through the outer center of a triangle formed by the centers of three adjacent positive lens elements.

The projection display device of the present invention comprises a light source, a light valve device on which light emitted from the light source is incident and an optical image is formed according to a video signal, and a projection lens for projecting the optical image on a screen. And using the above light valve device as the light valve device.

The viewfinder device according to the present invention comprises a light source, a light valve for forming an optical image in response to a video signal from the light emitted from the light source, and a magnifying lens for enlarging the optical image. The light valve device described above is used as the valve device.

[0015]

[Function] A model of the light valve device of the present invention is shown (FIG. 1).
Shown in. First lens array means 71 in order from the incident side,
The second lens array means 72 and the light valve 73 are arranged. Here, the light valve 73, the first lens array means 71, and the second lens array means 72 are all very thin, and the space between them is air. Light valve 7
The pixels 74 of 3 are arranged in a delta array. The first lens array means 71 and the second lens array means 72 are hexagonal positive lens elements 75 and 76 arranged in a delta arrangement, and it is assumed that there is no non-lens area. It is assumed that the positive lens elements 75 and 76 are all thin-walled lenses and are ideal lenses with no aberration. The pitch of the first lens array means 71 and the pitch of the second lens array means 72 are exactly the same as the pitch of the light valve 73, and each positive lens element 7 is arranged.
The optical axis 77 of 5 corresponds to the corresponding positive lens elements 76a, 76b,
The center 80 of the light valve 73 passes through the outer center 79 of the triangle 78 formed by the center of 76c, and the center 80 of the pixels 74a and 74b of the light valve 73.
It is assumed that a straight line connecting a and 80b passes through the midpoint 81.

An optical path diagram corresponding to (FIG. 1) is shown in (FIG. 2). The incident light 82 from the light source is the first lens array means 7
When incident on 1, each positive lens element 75 of the first lens array means 71 forms a minute real image 84 corresponding to the light source on each focal point 83. That is, the first minute light source group 85 is formed on the emission side of the first lens array means 71. Each positive lens element 76 of the second lens array means 72 is a real image 8 of the microscopic light source 84 rotated by 180 ° and having the same magnification.
6 is formed. That is, the second minute light source group 87 is formed on the emission side of the second lens array means 72. The pitch of the first minute light source group 85 and the pitch of the second minute light source group 87 are equal to each other. The pixel pitch of the light valve 73 is the second
Each pixel 74 of the light valve 73 can be overlapped with each minute light source 86 of the second minute light source group 87 if the pitch of the minute light source group 87 is equal.

If the distance from the focal point 83 to the principal point of the positive lens element 76 is longer than the focal length of the positive lens element 75, the light emitted from one positive lens element 75a of the first lens array means 71 is the second lens. The light enters the plurality of positive lens elements 76a and 76b of the array means 72. The emitted light is incident on any pixel of the light valve 73.
Thus, one pixel of the light valve 73 has a plurality of positive lens elements 76 a, 7 a of the second lens array means 72.
Light enters from 6b.

The focal length of each positive lens element 75 of the first lens array means 71 is f ₁ , and the second lens array means 7 is
The focal length of each positive lens element 76 of No. ₂ is f ₂ . Second
In order to overlap all the minute light sources 86 of the minute light source group 87,
B to the principal point of the lens array means 72, and c to the pixel 74 of the light valve 73 from the principal point of the second lens array means 72.

[0019]

[Equation 2]

[0020]

[Equation 3]

[0021] When the distance from the principal point of the first lens array means 71 to the focal point 83 is a,

[0022]

[Equation 4]

It becomes In the model shown in FIG. 1, c is restricted by the light valve 73, but a + b
There is no factor that constrains. Therefore, the focal length f ₁ of the first lens array means 71 can be shortened, and f
_{If 1} becomes short, each minute light source 86 of the second minute light source group 87
The size of becomes smaller. Further, as described above, since the light emitted from the first lens array means 71 reaches all the pixels 74 of the light valve 73 via the plurality of positive lens elements 76 of the second lens array means 72, ( (Fig. 1)
The substantial aperture ratio of the light valve device shown in FIG. When all the light emitted from each pixel of the light valve enters the projection lens, the projected image becomes bright.

Desirable conditions for improving the substantial aperture ratio by the configurations shown in FIGS. 1 and 2 will be described. An optical path diagram in a general case where light is incident on one pixel of the light valve from the plurality of positive lens elements of the second lens array means is shown in FIG. In the case of the state shown in FIG. 3, the positive lens elements 76a and 76b use only part of the effective area. In this case, the projection lens is wasteful because the middle part of the pupil is not used. In order to minimize this waste, 1 of the first lens array means 71 is used.
The light beam emitted from the end 88 of each positive lens element 75a is
It suffices that the second lens array means 72 pass through the end 89 of the set of adjacent positive lens elements 76a and 76b. This condition is that the focal length of each positive lens element 75 of the first lens array means 71 is f ₁ , the focal length of each positive lens element 76 of the second lens array means 72 is f ₂ , and a positive integer is m.

[0025]

[Equation 5]

[0026] FIG. 2 shows a case where the light emitted from one positive lens element 75 of the first lens array means 71 is incident on the second lens array means 72 and is incident on three positive lens elements 76. However, the number is not limited to three, and may be increased to 6, 12, or the like. In any case, it is desirable to satisfy (Equation 5).

According to the present invention, even when the distance from the incident side surface of the light valve to the light valve layer cannot be shortened, by using the two lens array means as in the model shown in (FIG. 1). A light valve device having a substantially high aperture ratio can be realized. By using this light valve device in a projection display device, a bright projected image can be obtained. If this light valve device is used in a viewfinder device, a bright display image can be obtained.

[0028]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The construction of the first embodiment of the light valve device of the present invention is shown in FIG. 91 is an incident side polarization plate, 92 is a first lens array plate, 93 is a second lens array plate, and 94.
Is a liquid crystal panel, and 95 is an emission side polarizing plate.

The light valve device is composed of an incident side polarization plate 91, a first lens array plate 92, a second lens array plate 93, a liquid crystal panel 94, and an emission side polarization plate 95 in order from the incidence side.

The liquid crystal panel 94 includes two glass substrates 9
TN liquid crystal 98 is sealed between 6, 97. Pixel electrodes made of a transparent conductive film are formed in a matrix on the liquid crystal layer 98 side of the emission side glass substrate 97, and a TFT 100 is provided as a switching element in the vicinity of each pixel electrode. A signal line and a scanning line are formed between adjacent pixel electrodes, and each TFT 100 has a source electrode connected to the signal line, a gate electrode connected to the scanning line, and a drain electrode connected to the pixel electrode. Incident side glass substrate 9
6, a common electrode made of a transparent conductive film is formed on the liquid crystal layer 98 side, and a black matrix 102 made of a metal thin film is formed thereon so as to cover the TFT 100, signal lines, and scanning lines. The openings of the black matrix 102 become the pixels 103. An alignment film is coated on the pixel electrode and the common electrode and rubbed to align the liquid crystal molecules in a predetermined state. When an electric field is applied to the liquid crystal layer of each pixel 103 by the signal supply circuit and the scanning circuit, the optical rotatory power of the liquid crystal layer changes according to the electric field, so that an optical image is displayed on the liquid crystal panel 94 as a change in optical rotatory power according to the video signal. Can be formed. This optical image becomes an optical image due to a change in transmittance due to the actions of the incident side polarization plate 91 and the emission side polarization plate 95.

The number of pixels of the liquid crystal panel 94 is horizontal 480 × vertical 460, the size of the display screen is horizontal 44.64 mm × vertical 33.58 mm, and the pixel pitch is horizontal 94 μm × vertical 73.
μm. The pixels 103 are in a square array as shown in (FIG. 5), and the dimensions of the pixels are horizontal 53 μm × vertical 32 μm.
m, the aperture ratio is 25%. Two glass substrates 96, 9
No. 7 has a thickness of 1.1 mm and a refractive index of 1.52.

The first lens array plate 92 is the glass substrate 1
04, a thin transparent resin 105 is laminated on the emission side surface, and a plurality of positive lens elements 106 are formed in a matrix on the surface thereof. And a plurality of positive lens elements 109 are formed in a matrix on the surface. The positive lens elements 106 and 109 have a delta arrangement as shown in FIG. Each of the positive lens elements 106 and 109 has a hexagonal effective area, and the arrangement pitch is horizontal 94 μm × vertical 73 μm, which is the same as the pixel pitch of the liquid crystal panel 94, and the width between adjacent positive lens elements is about 5 μm. Non-lens part 110, 111
Is provided. The first lens array plate 92 has a glass substrate 104 having a thickness of 1.1 mm, a refractive index of 1.52, and a focal length of 360 μm. Second lens array plate 93
The glass substrate 107 has a thickness of 1.6 mm, a refractive index of 1.52, and a focal length of 360 μm. The two lens array plates 92, 93 are formed by applying an ultraviolet curable resin on the glass substrates 104, 107 and stacking a mold having a predetermined lens array plate surface shape on the glass substrates 104, 107.
It is created by irradiating the ultraviolet curable resin with ultraviolet rays through 107.

The first lens array plate 92, the second lens array plate 93, and the liquid crystal panel 94 are the first lens array plate 92.
The optical axis 112 of each positive lens element 106 of each of the positive lens elements 109a, 109b, 109 of the second lens array plate 93
The optical axis 112 passes through the center 114a of the straight line connecting the centers 115a and 115b of the adjacent pixels 103a and 103b of the liquid crystal panel 94, and passes through the outer center 114 of the triangle 113 formed by the centers 110a, 110b, and 110c of c. As described above, the peripheral portion is fixed with an adhesive agent with a thin air layer interposed therebetween. The incident side polarization plate 91 is the first lens array plate 92.
The output side polarization plate 95 is separated from the liquid crystal panel 9
4 is attached to the output side.

A first embodiment of the projection type display device of the present invention will be described. (FIG. 6) shows the configuration, in which 121 is a light source, 125 is a field lens, and 12
6 is a light valve device, 127 is a projection lens, and 128 is a screen.

The light valve device 126 is (FIG. 4),
It is the same as that shown in FIG. 5 and comprises an incident side polarization plate 91, a first lens array plate 92, a second lens array plate 93, a liquid crystal panel 94, and an emission side polarization plate 95 in order from the incident side. There is.

The light source 121 includes a lamp 122 and a concave mirror 12.
3 and the filter 124. The lamp 122 is a halogen lamp, and the light emitted from the lamp 122 is reflected by the concave mirror 123 and emitted as light that is nearly parallel. The filter 124 is a glass substrate on which a multilayer film that transmits visible light and reflects infrared light is deposited.
Infrared light is removed from the light emitted from the concave mirror 123.

The light emitted from the light source 121 passes through the field lens 125 and enters the light valve device 126, and the emitted light enters the projection lens 127. In this way, the image formed on the liquid crystal panel 94 is projected onto the projection lens 12
7, the image is projected on the screen 128 in an enlarged scale. The field lens 125 is used to make the principal ray incident on the pixels in the peripheral portion of the liquid crystal panel 94 from the light source 121 perpendicular to the liquid crystal layer 98. The projection lens 127 is a liquid crystal panel 94.
It is composed of an auxiliary lens 129 and a main projection lens 130 which are arranged on the exit side of, and the aperture ratio is F3.5. The auxiliary lens 129 is for making the chief ray passing through all the pixels of the liquid crystal panel 94 perpendicular to the liquid crystal layer 98.
Thus, the positive lens element 10 of the first lens array plate 92
The light rays traveling along the optical axis 112 of No. 6 pass through the corresponding positive lens element 109 of the second lens array plate 93 and enter the center 115 of the corresponding pixel 103 of the liquid crystal panel 94.

The operation of the configuration shown in FIGS. 4 and 5 will be described. As shown in FIG. 4, the emitted light 117 from the light source 121 enters the first lens array plate 92. At the focal point 118 of each positive lens element 106 of the first lens array plate 92, a minute real image corresponding to the opening of the concave mirror 123 is formed. Each positive lens element 109 of the second lens array plate 93 forms the plurality of minute light sources on the liquid crystal layer 98 of the liquid crystal panel 94 at equal magnification. The focal length f ₁ of the positive lens element 106 of the first lens array plate 92 and the focal length f ₂ of the positive lens element 109 of the second lens array plate 93.
Means that the condition of (Equation 5) is satisfied. Therefore, one positive lens element 1 of the first lens array plate 92
The light emitted from 06a is emitted from the third lens array plate 93.
The light incident on the positive lens elements 109a and 109b and emitted from the three positive lens elements 109a and 109c enter the pixels 103c and 103d of the liquid crystal panel 94, respectively. One pixel 103d of the liquid crystal panel 94 has a second
Three adjacent positive lens elements 10 of the lens array plate 93
Light emitted from 9c and 109d enters. LCD panel 9
All the light emitted from No. 4 enters the projection lens 127. An optical image is formed on the light valve device 126 as a change in transmittance according to a video signal. This optical image is enlarged and projected by the projection lens 127, and the enlarged black and white projected image is displayed on the screen.

The first lens array plate 9 is emitted from the light source 121.
When all the light that has entered one positive lens element 106 of No. 2 enters the projection lens 127, the light valve device 12
The actual aperture ratio of 6 is the ratio of the area of the lens surfaces of all the positive lens elements to the area of the entire area of the first lens array plate 92. The brightness of the projected image at the screen center becomes brighter by the ratio of the actual aperture ratio to the actual aperture ratio of the liquid crystal panel.

When the two lens array plates 92 and 93 are combined and tested, the brightness near the screen center of the projected image can be increased by about 1.4 times as compared with the case where the lens array plates are not used. The effectiveness of the invention could be confirmed. Considering that the liquid crystal panel 94 has an aperture ratio of 25%, and the actual aperture ratio ignoring the surface reflections of the lens array plates 92 and 93 is theoretically 75%, the effect of improving the brightness is theoretical. Although it is much lower than the value, it is considered that the reason is that the accuracy of the lens surfaces of the lens array plates 92 and 93 is not good.

In the conventional structure shown in (FIG. 13), the incident side glass substrate of the liquid crystal panel needs to be thinned in order to make the projected image bright, but in the structure of the present invention shown in (FIG. 4). The projected image can be brightened without thinning the incident side glass substrate 96 of the liquid crystal panel 94. Since it is not necessary to thin the incident side glass substrate 96, the liquid crystal layer 98
The thickness uniformity of the liquid crystal panel 94 can be ensured.
It is possible to display a high quality image. for that reason,
With the configuration as shown in FIG. 4, it is possible to obtain a bright projected image with high image quality.

The configuration of the second embodiment of the projection display apparatus of the present invention is shown in FIG. 141 is a light source, 147, 148
Is a dichroic mirror, 149 is a plane mirror, 15
0, 151, 152 are field lenses, 153, 15
4, 155 are light valve devices, 171, 172, 17
Reference numeral 3 is an auxiliary lens, 174 and 175 are dichroic mirrors, 176 is a plane mirror, and 177 is a main projection lens.

The light source 141 includes a lamp 142 and a concave mirror 14.
3 and a filter 144. The lamp 142 is a metal halide lamp and emits light containing color components of three primary colors. The concave mirror 143 is made of glass and has a reflecting surface 145.
The shape of is a paraboloid, and a multilayer film that transmits infrared light and reflects visible light is vapor-deposited on the reflecting surface 145. The filter 144 is formed by depositing a multilayer film that transmits visible light and reflects infrared light and ultraviolet light on a glass substrate. The optical axis 146 of the concave mirror 143 is oriented horizontally, and the lamp 14
2 is arranged with its tube axis aligned with the optical axis 146. The light emitted from the lamp 142 is reflected by the concave mirror 143 to be converted into near-parallel light from which infrared light has been removed, passes through the filter 144 to remove infrared light and ultraviolet light, and is emitted as visible light.
The light emitted from the light source 141 is emitted from the two dichroic mirrors 1.
It is separated into red, green and blue primary color lights by a color separation optical system composed of 47, 148 and a plane mirror 149. Each of the primary color lights has a field lens 150, 151, 15
Light valve device 153, 154, 155 through 2
Incident on.

Light valve devices 153, 154, 155
Are the same as those shown in (FIG. 4), and the incident side polarization plates 156, 157, 15 are arranged in order from the light source side.
8, first lens array plate 159, 160, 161, second
Lens array plates 162, 163, 164, liquid crystal panel 1
65, 166, 167, output side polarization plates 168, 169,
It is a combination of 170. Light valve device 1
An optical image is formed on each of 53, 154, and 155 as a change in transmittance according to a video signal. The light emitted from the light valve devices 153, 154, 155, after passing through the auxiliary lenses 171, 172, 173, respectively, is combined into one light by a color combining optical system combining the dichroic mirrors 174, 175 and the plane mirror 176. The combined light enters the main projection lens 177.

The main projection lens 177 is an auxiliary lens 17
It functions as a projection lens when combined with 1,172,173. Auxiliary lenses 171, 172, 173
Is used so that the chief ray of the main projection lens 177 passes vertically through the liquid crystal layer, that is, to improve the telecentricity. Thus, the three light valve devices 153,
The optical images formed on 154 and 155 are the main projection lens 1
The image is enlarged and projected on a screen (not shown) at a distant position by 77.

When the projection type display device shown in FIG. 7 was prototyped and tested, a brighter projected image could be obtained as in the first embodiment, as compared with the case where the lens array plate was not used. . The uniformity of the image quality was also good, except for the obvious defective parts of the lens array plate.

The construction of the second embodiment of the light valve device of the present invention is shown in FIG. 191 is an incident side polarization plate, 19
Reference numeral 2 is a lens array plate, 193 is a liquid crystal panel, and 194 is an emission side polarization plate.

The light valve device is composed of an incident side polarization plate 191, a lens array plate 192, a liquid crystal panel 193, and an emission side polarization plate 194 in order from the incidence side.

The liquid crystal panel 193 is a TFT liquid crystal panel using the same TN liquid crystal as that shown in FIG.
A pixel electrode 197 and a TFT 198 are provided on the liquid crystal layer 196 side of the emission side glass substrate 195. On the liquid crystal layer 196 side of the incident side glass substrate 199, a black matrix 200 for shielding the TFT is provided, a mosaic color filter 201 is provided thereon, and a common electrode is further provided thereon. . 4 horizontal pixels
80 x vertical 460, the size of the display screen is horizontal 30.7 mm
× vertical 23.0 mm, pixel pitch is horizontal 64 μm × vertical 50 μm. Pixel size is horizontal 33μm x vertical 29
μm, the aperture ratio is 25%. The incident-side glass substrate has a thickness of 1.1 mm and a refractive index of 1.52.

The lens array plate 192 is the glass substrate 20.
The first lens array 203 is formed on the incident side surface of No. 2 and the second lens array 204 is formed on the exit side surface.
The first lens array 203 and the second lens array 204 are
Both are thin transparent resin 205 on the glass substrate 202,
206 is overlapped and convex lens surfaces 207 and 208 are formed on the surface thereof. Each positive lens element 207, 208
, The effective area is hexagonal as shown in (FIG. 9),
The liquid crystal panel 193 is arranged in delta at the same pitch. Each positive lens element 207, 208 has a non-lens portion 209, 210 having a width of 5 μm between the adjacent positive lens elements. The optical axis 211 of each positive lens element 207 is defined by three adjacent positive lens elements 208 of the second lens array 204.
Triangle 21 composed of a, 208b, and 208c centers
1 through the center 212. The glass substrate 202 has a thickness of 1.6 mm and a refractive index of 1.52. The first lens array 203 has a focal length of 360 μm and the second lens array 2 has a focal length of 360 μm.
The focal length of 04 is 360 μm.

Lens array plate 192 and liquid crystal panel 193
A thin air layer is sandwiched between the incident side glass substrate 195 and the incident side glass substrate 195, and the peripheral portion is fixed by an adhesive material. At this time, the optical axis 211 of each positive lens element 207 of the first lens array 203 is
The optical axis 211 of each positive lens element 207 of the first lens array 203 passes through the center 212 of a triangle 211 formed by the centers of three adjacent positive lens elements 208a, 208b, 208c of the second lens array 204. The corresponding two adjacent pixels 215a, 215b of the liquid crystal panel 193
It passes through the midpoint 217 of a straight line connecting the centers 216a and 216b of the. The configuration shown in FIG. 8 has a smaller number of boundary surfaces having a difference in refractive index than the case where two lens array plates are used, so that the transmittance is advantageous. Also in this case, the image of the virtual object on the focal point 218 of the positive lens element 207 of the first lens array 203 is formed on the pixel 215 of the liquid crystal panel 193 by the second lens array 204. The light emitted from one positive lens element 207 of the first lens array 203 is incident on the three positive lens elements of the second lens array 204, and one pixel 215 of the liquid crystal panel 193,
Light emitted from the seven positive lens elements of the second lens array 207 enters. Similar to the above-described embodiment, the lens array plate 192 can improve the substantial aperture ratio.
When the light valve device of the projection type display device having the configuration shown in (FIG. 6) is replaced with the light valve device shown in (FIG. 8), a full-color projected image can be obtained. In the experiment, the brightness near the center of the projected image was about 1.4 times that in the case without the lens array plate.

Next, an embodiment in which the light valve device of the present invention is applied to a viewfinder device will be described.
(FIG. 10) shows the structure, and 221 is a light valve device, 226 is a light source, and 229 is an eyepiece.

The light valve device 221 has the same structure as that shown in FIG. 8 although the dimensions of the respective parts are different.
It is composed of an incident side polarization plate 222, a lens array plate 223, a liquid crystal panel 224, and an emission side polarization plate 225 in order from the incidence side. The liquid crystal panel 224 is a TFT liquid crystal panel using a TN liquid crystal having the same configuration as the liquid crystal panel shown in FIG. 8 and has a mosaic color filter built therein.
The display size is 0.7 inch and displays a full color image. The number of pixels is horizontal 372 × vertical 238, the pixel pitch is horizontal 38 μm × vertical 44 μm, and the pixel size is horizontal 18.
μm × vertical 24 μm and the aperture ratio is 25%. Each of the glass substrates of the liquid crystal panel has a thickness of 1.1 mm and a refractive index of 1.52. The lens array substrate has a thickness of 1.6 m
m, the refractive index is 1.52, the focal length of the first lens array is 360 μm, and the focal length of the second lens array is 36.
It is 0 μm.

The light source 226 comprises a lamp 227 and a condenser lens 228. The lamp 227 is a direct-current fluorescent tube having a diameter of 7 mm and a length of 20 mm. The light that spreads and is emitted from the lamp 227 is collected by the condenser lens 22.
The light is converted into light having a narrow directivity by 8 and enters the light valve device 221, and the emitted light enters the eyepiece lens 229. When an observer looks through the eyepiece lens 229, an enlarged virtual image of the image on the light valve device 221 can be observed.

The above components are all in one housing 23.
It is stored in 0. As the lamp 227, it is preferable to use an LED, a halogen lamp, a cathode ray tube, or a light source with a small luminance and high brightness.

In the viewfinder device shown in FIG. 10, the use of the lens array increases the substantial aperture ratio of the light valve device, resulting in higher light utilization efficiency.
Therefore, the power of the lamp can be reduced, and the continuous use time in one battery charge becomes longer than in the case where the lens array is not used.

Another embodiment of the light valve device of the present invention will be described below. The first lens array and the second lens array that play an important role in the light valve device of the present invention need to support them. In addition to the above-described embodiment, a glass substrate is disposed close to the entrance side of the liquid crystal panel, the first lens array is formed on the entrance side surface of the glass substrate, and the entrance side or exit side surface of the entrance side glass substrate of the liquid crystal panel is formed. A configuration in which the second lens array is formed on either side is also possible.

The pitch of the positive lens elements of the first lens array may be slightly larger than the pixel pitch of the liquid crystal panel. If the pitch and arrangement of the second lens array are optimally selected by simple drawing of the optical path diagram, the real image of the minute light source formed at the focal point of each positive lens element of the first lens array
It can be seen that the lens array can be formed on the pixels of the liquid crystal panel. In this way, since the principal ray passing through the pixels in the peripheral portion of the liquid crystal panel can be directed to the inside, the auxiliary lens 129 used in the configuration shown in FIG. 6 can be omitted.

In the liquid crystal panel using the TN liquid crystal, the direction of good contrast is slightly tilted from the normal line of the liquid crystal layer. Therefore, in order to obtain a high-contrast projected image, the liquid crystal panel is tilted obliquely to the liquid crystal panel. Light should be incident.
In this case, the positive lens element group of the first lens array and the positive lens element group of the second lens array are slightly moved in parallel with respect to the pixel group of the liquid crystal panel, and are formed at respective focal points of the first lens array. A real image of the minute light source may be formed on each pixel of the liquid crystal panel.

As the method for producing the lens array plate, in addition to the method described in the first embodiment, a method of forming a gradient index lens on the surface of the glass substrate by ion exchange or selective diffusion, or on the glass substrate There is a method of forming a lens by stacking transparent thermoplastic resins and thermoforming them.

In the above embodiments, the case where the light valve is a TFT liquid crystal panel using TN liquid crystal has been described.
A light valve can be used as long as it can form an optical image as a change in optical characteristics, such as a liquid crystal panel of another type or an electro-optical crystal.

The display size, the number of pixels, the pixel size, etc. of the light valve device, the diameter and length of the light source, the focal lengths of the first lens array and the second lens array, etc. are limited to those of this embodiment. Needless to say, the same effect as in the present embodiment can be obtained by selecting other dimensions and numbers.

[0064]

As described above, according to the present invention, a light valve device having a large aperture ratio can be realized without restricting the light valve, and by using this light valve device, projection is possible. Since it is possible to provide a projection display device having a bright image and a viewfinder device having a bright display image with low power consumption, a very great effect can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a model for explaining the operation of a light valve device of the present invention.

FIG. 2 is a schematic diagram illustrating the operation of the light valve device of the present invention.

FIG. 3 is a schematic diagram illustrating the operation of the light valve device of the present invention.

FIG. 4 is an enlarged side sectional view of an essential part of the first embodiment of the light valve device of the present invention.

FIG. 5 is a schematic diagram in the first embodiment of the light valve device of the present invention.

FIG. 6 is a schematic configuration diagram of a projection display apparatus according to a first embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a projection display apparatus according to a second embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of a light valve device according to a second embodiment of the present invention.

FIG. 9 is a schematic diagram in the first embodiment of the light valve device of the present invention.

FIG. 10 is a schematic configuration diagram of an embodiment of a viewfinder device of the present invention.

FIG. 11 is a schematic configuration diagram of a conventional projection display device.

FIG. 12 is an enlarged side sectional view of an essential part showing the configuration of a liquid crystal panel.

FIG. 13 is an enlarged side sectional view of an essential part showing the configuration of a conventional light valve device.

[Explanation of symbols]

 71 First Lens Array Means 72 Second Lens Array Means 73 Light Valve 91 Incident Side Polarizing Plate 92 First Lens Array Plate 93 Second Lens Array Plate 94 Liquid Crystal Panel 95 Emitting Side Polarizing Plate 121 Light Source 125 Field Lens 126 Light Valve Device 127 Projection lens 128 screen 141 light source 147, 148 dichroic mirror 149 plane mirror 150, 151, 152 field lens 153, 154, 155 light valve device 156, 157, 158 incident side polarization plate 159, 160, 161 first lens array plate 162, 163, 164 Second lens array plate 165, 166, 167 Liquid crystal panel 168, 169, 170 Emitting side polarizing plate 171, 172, 173 Auxiliary lens 174, 175 Dichroic mirror 176 Flat surface 177 Main projection lens 191 Incident side polarization plate 192 Lens array plate 193 Liquid crystal panel 194 Emission side polarization plate 203 First lens array 204 Second lens array 221 Light valve device 222 Incident side polarization plate 223 Lens array plate 224 Liquid crystal panel 225 Emission Side polarizing plate 226 Light source 229 Eyepiece

Claims (8)

[Claims] 1. A light valve in which a plurality of pixels are arranged in a matrix in a delta arrangement, and a plurality of positive lens elements are arranged in a matrix similar to the pixel arrangement of the light valve.
Second lens array means and a plurality of positive lens elements arranged in a matrix similar to the pixel arrangement of the light valve.
Lens array means, the second lens array means is disposed on an incident side of the light valve,
Lens array means is disposed on the incident side of the second lens array means, and the focal length of each positive lens element of the first lens array means is the focal length of each positive lens element of the second lens array means. Equal to or shorter than each positive lens element of the second lens array means, each positive lens element of the second lens array means being a real image of a virtual object on the focal point of the plurality of positive lens elements of the first lens array means. The optical axis of each positive lens element of the first lens array means is formed on the corresponding pixel, and the optical axis of the positive lens element of the second lens array means forms the outer center of a triangle formed by the centers of four adjacent positive lens elements of the second lens array means. The light valve device according to claim 1, which passes through. 2. The second lens array means is formed on the exit side surface of the first transparent substrate arranged on the incident side of the light valve or near the surface thereof, and the first lens array means is the first transparent substrate. The second transparent substrate disposed on the incident side of the second transparent substrate is formed on the emission side surface or near the surface thereof.
The light valve device described. 3. The first lens array means is formed on or near the surface of either the entrance side or the exit side of a transparent substrate disposed on the entrance side of the light valve, or the second lens array means is formed on the surface thereof. The light valve device according to claim 1, wherein the light valve device is formed on an incident side surface of the light valve or in the vicinity thereof. 4. The first lens array means is formed on the incident side surface of the transparent substrate arranged on the incident side of the light valve or near the surface thereof, and the second lens array means is the exit side surface of the transparent substrate or its surface. The light valve device according to claim 1, which is formed in the vicinity. 5. A focal length of each positive lens element of the first lens array means is f ₁ , a focal length of each positive lens element of the second lens array means is f ₂ , and a positive integer is m. The light valve device according to claim 1, which satisfies: [Equation 1] 6. A light valve, comprising: a light source, a light valve device on which light emitted from the light source is incident to form an optical image in accordance with a video signal, and a projection lens which projects the optical image on a screen. Claims 1 to 5 as a device
A projection display device using the light valve device according to any one of 1. 7. The light valve device according to claim 1, further comprising a light source, a light valve on which light emitted from the light source is incident to form an optical image according to a video signal, and a magnifying lens for enlarging the optical image. To a viewfinder device using the light valve device according to claim 5. 8. The viewfinder device according to claim 7, wherein the light source comprises a light emitting means and a condenser lens for converting the light emitted from the light emitting means into light having a narrow directivity.