JP2000131507A - Lens array plate, light valve device, projection type display device, and viewfinder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the maximum tilt angle of projection light from becoming extremely large by forming the border between spherical or rotationally symmetrical aspherical surfaces and conic surfaces of every lens element in a specific arcuate shape and smoothly connecting the spherical or rotationally symmetrical non-spherical surface and conic surface. SOLUTION: The lens array plate is constituted by forming a thin resin layer 52 on a glass substrate 51, forming plural lens elements 53 in a square array on the surface of the resin layer 52 with their convex surfaces out, and further adhering a thin glass substrate 55 thereupon with an adhesive 54. The border of the effective area of lens elements 53 is a square. The lens surface of each lens element 53 has a spherical surface 59 at its center part 58 and a conic surface 61 at its peripheral part 60, and the spherical surface 59 and conic surface 61 are smoothly connected. The border 62 between the spherical surface 59 and conic surface 61 is circular and this border circle 62 is inscribed in the border of an effective area. Then the optical axis 63 of the lens element 53 passes the center of the effective area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens array plate in which a plurality of lens elements are arranged in a matrix, a light valve device using the lens array plate, a projection display device and a view using the light valve device. The present invention relates to a finder device.

[0002]

2. Description of the Related Art In order to obtain a large-screen image, a method of forming an optical image corresponding to an image signal on a light valve, irradiating the optical image with light, and enlarging and projecting the image on a screen by a projection lens is well known. Have been. Recently, a projection type display device using a liquid crystal panel as a light valve has attracted attention (for example, Japanese Patent Application Laid-Open No. 62-133424).
The liquid crystal panel uses an active matrix type in which a twisted nematic (TN) liquid crystal is used as a liquid crystal material and a TFT is provided in each pixel as a switching element in order to obtain a high quality projected image, and is used for red, green, and blue. It is becoming mainstream to use three liquid crystal panels.

[0003] The TFT liquid crystal panel is provided with a black matrix to shield the TFT and the wiring from light. For this reason, there is a problem that the pixel aperture ratio (the ratio of the area of all the openings of the black matrix to the entire area of the display area) is low, and the light output of the projection display device is reduced accordingly. This problem becomes more serious as the number of pixels of the liquid crystal panel increases and the pixel density increases. In order to solve this problem, there has been proposed a method of improving the light output by disposing a lens array plate close to the incident side of a liquid crystal panel (for example, Japanese Patent Application Laid-Open No. Hei 1-1990).
189885, JP-A-2-262185, etc.). Further, when the display area of the liquid crystal panel is small and the number of pixels is large, it is necessary to shorten the focal length of each lens element of the lens array plate, and it is necessary to make the incident side glass substrate of the liquid crystal panel thin. A method of disposing a lens element inside a glass substrate on the incident side has been proposed (JP-A-2-302726).

FIG. 11 shows a configuration of a light valve device in which a TFT liquid crystal panel and a lens array plate are combined. T
A lens array plate 12 is arranged on the incident side of the FT liquid crystal panel 11.

The liquid crystal panel 11 includes two glass substrates 1
An airtight space is formed by the seal resins 3 and 14 and a peripheral resin, and a TN liquid crystal 15 is sealed therein. A common electrode 16 made of a transparent conductive film is provided on the liquid crystal layer 15 side of the incident side glass substrate 13, and pixel electrodes 17 made of a transparent conductive film are formed in a square array on the liquid crystal layer 15 side of the emission side glass substrate 14. In the vicinity of each pixel electrode 17, a TFT 18 is formed as a switching element. Common electrode 16
An alignment film (not shown) is formed on the pixel electrode 17 to align the TN liquid crystal in a predetermined state. Intense light is incident on the liquid crystal panel.
In order to prevent erroneous operation of T18, a black matrix 21 made of a metal thin film that shields the TFT 18 and the wiring from light is formed on the liquid crystal layer 15 side of the incident side glass substrate 13. The opening of the black matrix 21 becomes the pixel 22. T
When a signal voltage is applied to the liquid crystal layer of each pixel 22 via the FT 18, an optical image is formed on the liquid crystal layer 15 as a change in optical rotation.

The lens array plate 12 is formed by forming a thin resin layer 24 on a glass substrate 23, and forming a plurality of lens elements 25 having a convex surface facing the surface 26 of the resin layer 24 in a square array. . The lens surface 26 is a spherical surface.

In the lens array plate 12, the optical axis 27 of the lens element 25 is located at the center of the pixel 22 of the liquid crystal panel 11 (the area center; therefore, in cross section, as shown in FIG.
And the optical axis 27 may be displaced. ) Is adhered to the incident side glass substrate 13 of the liquid crystal panel 11 by an adhesive 28 so as to pass through. The refractive index of the adhesive 28 is lower than the refractive index of the resin layer 24, and the lens surface 26 has a positive refractive power. The focal point of each lens element 25 is configured to be located near the center of the pixel 22.

[0008] Polarizing plates (not shown) are arranged on the incident side of the lens array plate 12 and the exit side of the liquid crystal panel 11 with their absorption axes directed in predetermined directions. The two polarizing plates are
The change in optical rotation of the liquid crystal layer 15 is converted into a change in transmittance.
Thus, an optical image is formed on the light valve device as a change in transmittance.

As shown in FIG. 12, light emitted from a light source 32 is transmitted through a lens element 25 positioned on an optical axis 33 of the light source 32.
Incident on the focal point 29 of the lens element 25
Is formed. The beam diameter becomes minimum at the position of the focal point 29. If the size of the real image 34 is smaller than the size of the pixel 22, all the light emitted from the lens element 25 passes through the pixel 22. When the lens array plate 12 is not used, light that does not pass through the pixels 22 also passes through the pixels 22 by using the lens array plate 12, so that the amount of light emitted from the liquid crystal panel 11 increases. If the projection lens can capture the light passing through the pixel 22,
The light output of the projection display device can be improved. An increase in the light output means that the effective aperture ratio becomes higher than the actual aperture ratio of the liquid crystal panel 11.

There is also a conventional example in which the focal point of the lens element 25 is located on the emission side of the pixel 22. Also in this case, by using the lens array plate 25, the amount of light emitted from the lens element 25 and passing through the pixels 22 can be increased by using the lens array plate 25. Also in this case, it is necessary that the projection lens can capture the light that has passed through the pixel 22.

[0011]

As can be seen from FIG. 12, the divergence angle of the light passing through the lens array plate 12 is larger than the divergence angle of the illumination light. Therefore, in order to improve the light output of the projection display device by combining the liquid crystal panel 11 with the lens array plate 12, it is necessary to reduce the F value so that the projection lens can take in all the light emitted from the lens element 25. When three liquid crystal panels are used, it is necessary to dispose a color combining optical system between the liquid crystal panel and the projection lens. However, when the divergence angle of light emitted from the liquid crystal panel becomes large, the color combining optical system becomes difficult. It is necessary to increase the optical path length, and it is necessary to increase the back focus of the projection lens with the increase in the optical path length. If an attempt is made to reduce the F-number of the projection lens and increase the back focus, there is a problem that the projection lens becomes considerably large and the projection display device becomes large.

In particular, when the pixels of the light valve device are arranged in a square, it is preferable that the effective area of each lens element 25 be square, as shown in FIG.
This will be discussed because it has a significant effect on the value.

As shown in FIG. 14, the light emitted from the light source 32 is transmitted through a lens element 25 positioned on the optical axis 33 of the light source 32.
Consider the case where light is incident on. FIG. 14 shows a state in which a light ray travels in a plane including the optical axis 27 of the lens element 25 and perpendicular to the screen.
FIG. 14A shows a state in which a light ray travels in a diagonal plane including the optical axis 27 of the lens element 25 in FIG. Here, in consideration of using a combination of a lamp and a concave mirror as the light source, the effective area of the light emitted from the light source 32 is a circle. Further, it is assumed that the lens element 25 is a thin lens and the exit side of the lens element 25 is air.

[0014] As shown in FIG.
In the plane perpendicular to the screen and including the optical axis of the light source 32, the light beam emitted from the lens element 25 having the largest inclination angle (the angle between the light ray and the optical axis of the lens element) is the edge 36 of the light source 32.
, And is incident on the center 37 of each side of the square forming the boundary of the effective area 35 of the lens element 25.
Further, as shown in FIG. 14B, in the plane in the diagonal direction, among the light rays emitted from the lens element 25, those having the largest inclination angle emit the edge 36 of the light source 32 and The light ray 40 is incident on a square vertex 39 that forms a boundary of the area 35. Outgoing ray 4 corresponding to ray 40
The tilt angle of 1 is considerably large, about 1.4 times the tilt angle of the output light beam 42 corresponding to the light beam 38.

As shown in FIG. 13, the ratio of the area of the inscribed circle 43 to the area of the square effective area 35 of the lens element 25 is 78.5%. The area ratio of the regions is 21.5%. When comparing the case where only the light emitted from the inscribed circle 43 of the effective area 35 of the lens element 25 is used with the case where the light emitted from the entire effective area 35 is used, the light output of the latter is one of the light output of the former. .
Although the magnification is 27 times, the F value required for the latter projection lens is 1 / 1.4 times that of the former. This means that the latter projection lens has an extremely large outer shape and a very high cost. Therefore, when an attempt is made to increase the light output of a projection display device by combining a lens array plate with a liquid crystal panel in which pixels are arranged in a square array, there arises a problem that the entire device becomes large and the cost becomes extremely high.

In addition, a liquid crystal panel has been used as a view finder in a video camera in order to make the whole video camera smaller and lighter and to improve portability. In order to reduce the size and weight of the viewfinder and display high-quality images on the liquid crystal panel, it is necessary to reduce the display screen size of the liquid crystal panel and increase the number of pixels. That is, it is necessary to reduce the pixel pitch of the liquid crystal panel. Then, the display image becomes dark because the aperture ratio of the liquid crystal panel becomes small. To brighten the displayed image, a bright light source may be used. However, the power consumption of the light source increases, and a problem occurs that the continuous use time in one battery charge is shortened.

According to the present invention, in consideration of the above-mentioned problems of the conventional lens array plate, light valve device, projection display device, and viewfinder device, a lens in which the maximum inclination angle of the emitted light does not become extremely large. It is an object to provide an array plate. It is another object of the present invention to provide a light valve device capable of increasing the effective aperture ratio without extremely increasing the maximum inclination angle of the emitted light by including the lens array plate.
Furthermore, by having this light valve device,
It is an object of the present invention to provide a compact projection display device having a large light output and a viewfinder device having low power consumption and a bright display image.

[0018]

In order to solve the above-mentioned problems, a first invention (corresponding to the first invention) is provided.
Comprises a plurality of lens elements arranged in a matrix, the effective area of the lens elements is square or rectangular, and the lens surface of each lens element is disposed at the center of the lens surface A spherical surface or a rotationally symmetric aspheric surface that generates a positive refractive power, and a conical surface that generates a positive refractive power disposed around the spherical surface or the rotationally symmetric aspherical surface. The boundary with the conical surface is one or more arcs forming a part of the circumference of one circle or the circumference of one circle, and the spherical surface or the rotationally symmetric aspheric surface and the conical surface, This is a lens array plate that is connected smoothly.

According to a second aspect of the present invention (corresponding to the fourth aspect of the present invention), a lens array plate of the present invention, and a light valve in which a plurality of pixels corresponding to each of the lens elements are arranged in a matrix. Wherein the lens array plate is disposed on the light-incident side of the light valve, and the optical axis of each lens element passes through the center of the corresponding pixel.

According to a third aspect of the present invention (corresponding to the seventh aspect of the present invention), a light source and a light valve device of the present invention for emitting light emitted from the light source as an optical image according to a video signal are provided. And a projection lens for enlarging and projecting the optical image emitted from the light valve device onto a screen.

According to a fourth aspect of the present invention (corresponding to an eighth aspect of the present invention), there is provided a light source, and a light valve device of the present invention for emitting light emitted from the light source as an optical image in accordance with a video signal. And an eyepiece for observing the optical image emitted from the light valve device.

[0022]

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

(First Embodiment) First, the first embodiment of the present invention will be described.
An embodiment will be described with reference to the drawings.

FIGS. 1 and 2 show a schematic configuration of a lens array plate according to a first embodiment of the present invention. FIG. 1 is a plan view, and FIG. 2 is a diagonal sectional view. 1 and 2, 51 is a glass substrate, 52 is a resin layer,
53 is a lens element, 54 is an adhesive, 55 is a glass substrate,
59 is a spherical surface and 61 is a conical surface.

The lens array plate in this embodiment is
A plurality of lens elements 53 each having a thin resin layer 52 formed on a glass substrate 51 and having a convex surface facing outward on the surface of the resin layer 52.
Are formed in a square array, and a thin glass substrate 55 is further adhered thereon by an adhesive 54.

The boundary 57 of the effective area 56 of the lens element 53
Is a square. In the lens surface of the lens element 53, the central portion 58 is a spherical surface 59, the peripheral portion 60 is a conical surface 61, and the spherical surface 59 and the conical surface 61 are smoothly connected. A boundary 62 between the spherical surface 59 and the conical surface 61 is a circle, and the boundary circle 62 is inscribed in a boundary 57 of the effective area 56. The optical axis 63 of the lens element 53 passes through the center of the effective area 56.

The dimensions of the entire effective area of the lens array plate are 26.62 mm horizontally × 19.97 mm vertically, and the lens element 5
The number 3 is 1024 horizontal × 768 vertical, the lens element 53
Has a horizontal dimension of 26 μm × vertical dimension of 26 μm, and the effective area 56 of the lens element 53 has a horizontal dimension of 25 μm × vertical dimension of 25 μm. Seen on the optical axis 63, the thickness of the glass substrate 51 is
1.0 mm, the thickness of the resin layer 52 is 13 μm, the adhesive 5
4 has a thickness of 6 μm, and the glass substrate 55 has a thickness of 77 μm.
m. The radius of curvature of the spherical surface 59 is 24 μm, and the resin layer 5
2, the refractive index of the adhesive 54 is 1.59.
38. The focal length of the lens element 53 is 11
4 μm.

The lens array plate shown in FIGS. 1 and 2 is produced as follows. For good surface accuracy, both surfaces are polished, apply an ultraviolet curable resin on the glass substrate 51, stack a mold having a predetermined shape on it, and irradiate ultraviolet light from the glass substrate 51 side to cure the ultraviolet curable resin. Thus, the outer surface of the resin layer 52 is formed. Next, an ultraviolet-curable adhesive is applied on the resin layer 52, a glass substrate having a thickness of 0.7 mm is stacked thereon, and ultraviolet rays are irradiated from the glass substrate 55 side to cure the ultraviolet-curable adhesive. Finally, the outer surface of the glass substrate 55 is ground and polished so that the entire surface of the lens array plate is 1.1 mm in thickness with good surface accuracy.

The operation of the lens array plate shown in FIGS. 1 and 2 will be described.

As shown in FIG. 3, it is assumed that light emitted from a disk-shaped light source 64 enters a lens element 53 located on an optical axis 65 of the light source 64. It is assumed that the lens element 53 is a thin lens and the exit side of the lens element is air. FIG. 3A shows a state in which a light ray travels in a plane including the optical axis of the lens element 53 and perpendicular to the screen, and FIG. 3A shows a state in which a light ray travels in a plane including the optical axis 63 of the lens element 53 and in a diagonal direction. Shown in b).

When viewed in a plane perpendicular to the screen, FIG.
As shown in (5), the light beam emitted from the light source 64 and incident on the lens element 53 is incident on the spherical surface 59, so that a circular light source image 67 is formed near the focal point 66. Of the light beams emitted from the lens element 53, those having the largest inclination angle
Is a light ray 71 generated by a light ray 70 emitted from the edge 68 of the lens element 53 and incident on the point 69 on the boundary circle 62 of the lens element 53.

As viewed in a diagonal plane, as shown in FIG. 3B, light emitted from the light source 64 and incident on the spherical surface 59 of the lens element 53 forms a light source image 67 near the focal point 66. . Among the light rays emitted from the spherical surface 59 of the lens element 53, those having the largest inclination angle are emitted light rays 75 generated by the light rays 74 emitted from the edge 72 of the light source 64 and incident on the point 73 on the boundary circle 62 of the lens element 53. It is. The outgoing light beam 77 generated by the light beam 76 emitted from the edge 72 of the light source 64 and incident on an arbitrary point on the conical surface 61 of the lens element 53 is:
The distance from the light source 64 to the lens element 53 is
Since the pitch is sufficiently longer than the pitch of No. 3, the light travels substantially parallel to the light beam 75. Accordingly, the maximum value of the inclination angle of the light beam emitted from the conical surface 61 of the lens element 53 is substantially equal to the inclination angle of the light beam 75, and is smaller than the maximum value of the inclination angle of the emitted light beam when the peripheral portion 60 is spherical. .

The cross-sectional shape of the light beam on the focal point 66 is a circle 78 as shown in FIG.
Thus, the light emitted from the spherical surface 59 and the conical surface 61 becomes a pin-shaped shape 79 circumscribing a circle 78 as shown in FIG.
The cross-sectional shape of the light flux in the space from the lens element 53 to the focal point 66 also becomes a pincushion shape.

As described above, in the lens array plate of the present invention, the cross-sectional shape of the light beam in the space from the lens element 53 to the focal point 66 is a pincushion shape, and the maximum light beam inclination angle is larger than when the entire lens surface is spherical. The value decreases. If the pixel of the light valve combined with the lens array plate has a square shape, the light emitted from the lens element 53 passes through the four corners of the pixel even if the sectional shape of the light flux in the space from the lens element 53 to the focal point 66 is pincushion. The effective aperture ratio of the light valve device can be increased. Since the maximum inclination angle of the light beam emitted from the lens element is small, the F value of the projection lens does not need to be extremely small, and the external shape of the projection lens does not become so large. Therefore, by using the lens array plate of the present invention, it is possible to provide a compact projection display device having a high light output.

The lens array plate shown in FIGS. 1 and 2 has a spherical surface 5 of the lens element 53 in order to reduce aberration.
9 may be replaced by a rotationally symmetric aspherical surface. However, the rotationally symmetric aspheric surface and the conical surface are connected smoothly.
In this case, the light source image 67 near the focal point 66 can be reduced.

FIG. 1 shows a case where the boundary circle 62 of the lens element 53 is in contact with the boundary 57 of the effective area 56. However, the diameter of the boundary circle 62 may be the same as the pitch of the lens element 53. Alternatively, as shown in FIGS. 5A and 5B, the diameter of the boundary circle 62 may be slightly larger than the width of the effective area 56, or may be slightly smaller. In any case, it is preferable that the center of the boundary circle 62 of the lens element 53 coincides with the center of the effective area 56. that way,
At the same time as minimizing the maximum tilt angle of the light beam emitted from the lens element 53, the light beam diameter near the focal point 66 of the lens element 53 can be minimized. In any case, it is possible to provide a compact projection display device having a high light output.

The effective area of the lens element may be rectangular. However, even in this case, the boundary between the spherical surface or the rotationally symmetric aspheric surface and the conical surface for each lens element is defined by one or a plurality of arcs that form a part of the circumference of one circle or the circumference of one circle. Need to be.

The lens array plate of the present invention has a plurality of lens elements 53 formed on at least a glass substrate 51. Therefore, not only the glass substrate 51, the resin layer 52, the adhesive 54, and the glass substrate 55 as shown in FIGS. 1 and 2 but also the glass substrate 51, the resin layer 52, and the adhesive 54. May be used, or may be made of a glass substrate 51 and a resin layer 52. In short, the lens array plate of the present invention includes a plurality of lens elements arranged in a matrix, the effective area of the lens elements is square or rectangular, and the lens surface of each lens element is the lens. A spherical surface or a rotationally symmetric aspheric surface which generates a positive refractive power and a conical surface which generates a positive refractive power and are arranged around the spherical surface or the rotationally symmetric aspheric surface arranged at the center of the surface, and the spherical surface for each lens element Alternatively, the boundary between the rotationally symmetric aspheric surface and the conical surface is one or more arcs forming a part of the circumference of one circle or the circumference of one circle, and the spherical surface or the rotationally symmetric aspheric surface is not limited thereto. It suffices if the spherical surface and the conical surface are smoothly connected.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
An embodiment will be described with reference to the drawings. The lens array plate according to the present embodiment differs from the lens array plate according to the above-described first embodiment only in the direction of the lens surface and the refractive index. The same is true. Therefore, in the present embodiment, components that are not particularly described are assumed to be the same as those in the first embodiment, and the components having the same names as those in the first embodiment will be the same as those in the first embodiment unless otherwise described. It has the same function as the embodiment.

FIG. 6 shows a schematic cross-sectional configuration in the diagonal direction of a lens array plate according to a second embodiment of the present invention, where 81 is a glass substrate, 82 is a resin layer, 83 is a lens element, 84 Is an adhesive, and 85 is a glass substrate.

In the lens array plate shown in FIG. 6, the direction of the lens surface of the lens array plate shown in FIGS. 1 and 2 is reversed.
The refractive index of the adhesive 84 is higher than the refractive index of the resin layer 82. The lens surface of the lens element 83 is a spherical surface 89 at the central portion 88 and a conical surface 91 at the peripheral portion 90, and the spherical surface 89 and the conical surface 91 are smoothly connected.

The lens array plate shown in FIG. 6 also provides the same operation as that shown in FIGS. 1 and 2, and can provide a compact projection display device having a large light output.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
An embodiment will be described with reference to the drawings. The light valve device according to the present embodiment is configured by bonding a liquid crystal panel instead of the glass substrate 55 of the lens array plate in the first embodiment described above.
Therefore, in the present embodiment, components that are not particularly described are assumed to be the same as those in the first embodiment, and the components having the same names as those in the first embodiment will be the same as those in the first embodiment unless otherwise described. It has the same function as the embodiment.

FIG. 7 shows the configuration of a light valve device according to a third embodiment of the present invention.
Denotes a liquid crystal panel, 102 denotes a lens array plate, and 103 denotes an adhesive.

In the light valve device, a lens array plate 102 is bonded to an incident side of a liquid crystal panel 101 with an adhesive 103.

The liquid crystal panel 101 has two glass substrates 1
A TN liquid crystal 106 is sealed between the cells 04 and 105. Pixel electrodes 107 made of a transparent conductive film are formed in a square array on the liquid crystal layer 106 side of the emission side glass substrate 105, and a TFT 108 is provided near each pixel electrode 107 as a switching element. Adjacent pixel electrode 1
08, a signal line and a scanning line are formed.
Reference numeral 8 denotes 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 107. On the liquid crystal layer 106 side of the incident side glass substrate 104, a black matrix 114 of a metal thin film as shown in FIG. 8 is formed to shield the TFTs 108, signal lines and scanning lines, and a transparent conductive film is formed thereon. A common electrode 115 is formed. Each opening of the black matrix 114 has a square shape, and this opening becomes the pixel 116. An alignment film (not shown) is applied on the pixel electrode 107 and the common electrode 115, and is rubbed to align liquid crystal molecules in a predetermined state. LCD panel 10
1 indicates that the size of the display area is 26.62 mm horizontal × 1 vertical
9.97 mm, the number of pixels is horizontal 1024 × vertical 768, the pixel pitch is horizontal 26 μm × vertical 26 μm, and pixel 1
The dimensions of the 16 effective areas are horizontal 19 μm × vertical 19 μm,
The aperture ratio is 51%.

The configurations of the glass substrate 119, the resin layer 120, and the adhesive 103 are exactly the same as the configurations of the glass substrate 51, the resin layer 52, and the adhesive 54 of the lens array plate shown in FIGS. That is, the lens array plate 102
Is formed by forming a thin resin layer 120 on the emission side surface of a glass substrate 119, and forming a plurality of lens elements 122 having a convex surface facing the surface 121 in a square array. The boundary of the effective area of the lens element 122 is a square. The lens surface of the lens element 122 has a spherical surface 126 at a central portion 125, a conical surface 128 at a peripheral portion 127, and a spherical surface 126.
And the conical surface 128 are smoothly connected. Spherical surface 12
The boundary 129 between 6 and the conical surface 128 is a circle, and this boundary circle 129 is inscribed in the effective area boundary 57.

The lens array plate 102 is provided for each lens element 1
The optical axis 130 of the pixel 22 corresponds to the center of the corresponding pixel 116 (the center of the area; therefore, in cross section, as shown in FIG.
The center of the cross section 6 and the optical axis 130 may be shifted. ) Is adhered to the liquid crystal panel 101 by an adhesive 103 so as to pass through. The focal point of each lens element 122 is located near the center of the pixel.

On the incident side of the lens array plate 102 and the exit side of the liquid crystal panel 101, polarizing plates (not shown) are arranged with their absorption axes directed in predetermined directions. When an electric field is applied to the liquid crystal layer 106 of each pixel 116 by the signal supply circuit and the scanning circuit, the optical rotation of the liquid crystal layer 106 changes according to the electric field. An image is formed. This optical image is converted by the two polarizing plates into an optical image due to a change in transmittance.

The light valve device shown in FIG. 7 is manufactured as follows. In the method described with reference to FIGS. 1 and 2, the glass substrate 119, the resin layer 120, the adhesive 103,
After forming a lens array plate composed of a glass substrate 104, a black matrix 1 is placed on the glass substrate 104.
14, and a common electrode 115 is further formed thereon to form a first substrate. T on the glass substrate 105
The FT 108, the pixel electrode 107, and the like are formed to form a second substrate. The first substrate and the second substrate are bonded to each other by a sealing resin at the peripheral portion so as to form a thin sealed space therebetween, and the TN liquid crystal 106 is sealed in the sealed space.

Assuming that the focal length of the lens array plate 102 is f and the air-converted optical path length from the vertex of the lens element 122 to the center of the pixel 116 is s, in the configuration shown in FIG.
114 μm, s = 57 μm, and f = 2 s.

The relation between f and s is most preferably f = 2s. However, if f / s is in the range of 1.5 to 3,
The effective aperture ratio can be sufficiently increased as compared with the conventional case. When f / s is smaller than 1.5, F of the projection lens
It is difficult to reduce the value, and when f / s is greater than 3, it is difficult to sufficiently increase the effective aperture ratio. Further, when the screen size of the liquid crystal panel is large and the F value of the illumination light is sufficiently large, if there is room to reduce the F value of the projection lens, f = s may be set.

When the light valve device shown in FIG. 7 is used for a projection display device, the F value of the light source is F _S , the F value of the lens element 122 of the lens array plate 102 is F _L , and the F value of the projection lens is F. _It is preferable that _P is configured so as to satisfy the relationship of Expressions 1 and 2.

[0054]

(Equation 1)

[0055]

(Equation 2)

As described above, when the light valve device of the present invention using the lens array plate in which a plurality of lens elements each having a combination of a spherical surface and a conical surface are arranged in a square, the operation and effect of the above-described lens array plate are achieved. In addition, it is possible to provide a compact projection display device having a higher light output than before.

In the present embodiment, the light valve device of the present invention is configured by bonding a TFT liquid crystal panel instead of the glass substrate 55 of the lens array plate in the first embodiment. However, the present invention is not limited to this, and for example, a structure in which another type of liquid crystal panel is bonded instead of the glass substrate 85 of the lens array plate in the second embodiment may be used. . In short, the light valve device of the present invention includes the lens array plate of the present invention, and a light valve in which a plurality of pixels corresponding to each of the lens elements are arranged in a matrix, wherein the lens array plate includes the light valve. , And the optical axis of each lens element only needs to pass through the center of the corresponding pixel.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described.
An embodiment will be described with reference to the drawings. The projection display device according to this embodiment includes the light valve device according to the third embodiment described above. Therefore, in the present embodiment, components that are not particularly described are the same as those in the third embodiment.

FIG. 9 shows a configuration of a projection type display apparatus according to a fourth embodiment of the present invention, wherein 141 is a light source, 146 and 147 are dichroic mirrors,
9, 150, 155 are field lenses, 151, 15
3 is a relay lens, 156, 157, 158, 162,
163, 164 are polarizing plates, 159, 160, 161 are light valve devices, 165 is a color combining prism, and 172 is a projection lens.

The light source 141 includes a lamp 142 and a concave mirror 14.
3. The lamp 142 is a metal halide lamp, and emits light including three primary color components. The concave mirror 143 is an elliptical mirror. The emitted light of lamp 142 is
The light is reflected by the concave mirror 143 and emitted as nearly parallel light from which infrared light has been removed.

The visible light included in the light emitted from the light source 141 passes through the filter 144 and is reflected by the cold mirror 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, and the cold mirror 145 reflects visible light on the glass substrate and emits red light. An optical multilayer film that reflects external light is deposited.

The light reflected by the cold mirror 145 is
Of the light that has entered the blue transmission dichroic mirror 146 and transmitted, blue light is transmitted, and red light and green light are reflected. Red light and green light are green reflection dichroic mirror 1
47, of which red light is transmitted and green light is reflected. The blue light transmitted through the blue transmission dichroic mirror 146 is reflected by the plane mirror 148 and enters the field lens 149, and the green light reflected by the green reflection dichroic mirror 147 directly enters the field lens 150. Green reflective dichroic mirror 14
7, the first relay lens 151, the plane mirror 152, the second relay lens 153, and the plane mirror 15.
4 and sequentially enters the field lens 155.
The light emitted from each of the field lenses 149, 150, and 155 passes through the incident-side polarizing plates 156, 157, and 158, respectively, and the corresponding light valve devices 159, 160, and 155, respectively.
161.

Light valve devices 159, 160, 161
Is the same as that shown in FIG. 7, and an optical image is formed as a change in optical rotation according to a video signal. The field lenses 149, 150, and 151 are used to make chief rays incident on pixels at the periphery of the light valve device perpendicular to the liquid crystal layer.

Light valve devices 159, 160, 161
Is transmitted through the output side polarizing plates 162, 163, and 164, and is incident on the color combining prism 165. The color synthesizing prism 165 has a red reflecting dichroic multilayer film and a blue reflecting dichroic multilayer film attached to the slopes of the four triangular prisms. The prisms are joined. The three primary color lights incident on the color combining prism 165 are combined into one light by the red reflection dichroic multilayer film and the blue reflection dichroic multilayer film,
The combined light is incident on the telecentric projection lens 172 at F2.2.

Thus, the three light valve devices 159,
The optical images formed on 160 and 161 are
2 is enlarged and projected on a screen arranged at a distance.

In the projection display device shown in FIG. 8, a lens array plate in which lens elements each having a combination of a spherical surface and a conical surface are arranged in a square is combined with a light valve device, so that the F value of the projection lens 172 is extremely reduced. Since the effective aperture ratio of the light valve device can be improved without the need, the entire device can be made compact and the light output can be increased.

In the present embodiment, the projection type display device of the present invention has been described as including the light valve device of the third embodiment. However, the present invention is not limited to this. The light valve device of the present invention may include the lens array plate of the present invention and another type of liquid crystal panel described as a modification in the third embodiment. In short, the projection display device of the present invention includes a light source, a light valve device of the present invention that emits light emitted from the light source as an optical image according to a video signal, and the optical device that is emitted from the light valve device. What is necessary is just to provide a projection lens for enlarging and projecting the image on the screen.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described.
An embodiment will be described with reference to the drawings. The viewfinder device of the present embodiment has the same basic configuration as the light valve device of the third embodiment described above. Therefore, in the present embodiment, those which are not particularly explained
It is assumed to be the same as the embodiment.

FIG. 10 shows a configuration of a viewfinder device according to a fifth embodiment of the present invention.
182, 183, 184 are LEDs, 185 is a color combining prism, 191 is a condenser lens, 192 is a light valve device, 197 is an eyepiece, and 198 is a housing.

A light source is constituted by three LEDs 182, 183, 184 emitting red light, green light and blue light, respectively, and a color combining prism 185. Each LED 182,1
83 and 184 both have a directivity narrowed by combining a positive lens element immediately after the semiconductor chip. The color combining prism 185 includes three prisms 186, 18
7, 188 are combined so that a green reflective dichroic multilayer film and a red reflective dichroic multilayer film are sandwiched between adjacent prisms. The light emitted from the three LEDs 182, 183, 184 is emitted from the prism 186 by the color combining prism 185, and the directivity is further narrowed by the condenser lens 191 to enter the light valve device 192.

The light valve device 192 is the same as the light valve device shown in FIG.
6.64mm x 12.48mm vertical, 6 horizontal pixels
The configuration is changed to 40 × vertical 480 and uses liquid crystal having a high response speed, and the others are exactly the same as those shown in FIG. The light-incident side and the light-emitting side of the light valve device 192 each have an absorption axis directed in a predetermined direction.
3,194 are affixed.

The light emitted from the light valve device 192 enters an eyepiece 197 obtained by combining two lenses 195 and 196. When the observer looks into the eyepiece 197, an enlarged virtual image corresponding to the image formed on the light valve device 192 can be observed. Optical system,
The drive circuits are all housed in one housing 198. The housing 198 has a configuration in which the lens 196 can be moved in the optical axis direction of the lenses 195 and 196, so that the diopter can be adjusted.

The light valve device 192 sequentially forms red, green, and blue optical images according to video signals by time-division driving, and the three LEDs 182, 183, and 184 turn red in synchronization with driving of the light valve device. , Green and blue in this order, the observer can observe a full-color image.

The viewfinder device shown in FIG.
Since the effective aperture ratio of the light valve device is increased by using the lens array plate, the light use efficiency is increased. The F value of the observer's eye changes depending on the brightness of the display image of the light valve device, but there is a lower limit. For this reason, even if the effective aperture ratio of the light valve device is improved, a case where the displayed image does not become bright sometimes occurs. However, when the lens array plate of the present invention is used, the brightness of the display image is improved because the maximum value of the inclination angle of the light emitted from the light valve device is small even if the effective aperture ratio is the same. Since there is room in the brightness of the displayed image, the power consumption of the LED can be reduced,
The continuous use time in one battery charge can be extended as compared with the case where the lens array plate is not used.

It should be noted that the viewfinder device of the present invention
In the present embodiment, the light valve device according to the third embodiment has the same basic configuration as that of the third embodiment. However, the present invention is not limited to this. The light valve device according to the present invention may include the lens array plate according to the present invention and another type of liquid crystal panel described as a modification. In short, the viewfinder device of the present invention includes a light source, a light valve device of the present invention that emits light emitted from the light source as an optical image according to a video signal, and the optical image emitted from the light valve device. And an eyepiece for observing the image.

[0076]

As is apparent from the above description, the present invention according to claims 1 to 3 can provide a lens array plate in which the maximum inclination angle of emitted light does not become extremely large.

The present invention according to claims 4 to 6 can provide a light valve device capable of increasing the effective aperture ratio without extremely increasing the maximum inclination angle of the emitted light.

Further, according to the present invention, a projection type display device having a large light output can be obtained.

The present invention according to claim 8 can provide a viewfinder device with low power consumption and a bright display image.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a configuration of a lens array plate according to a first embodiment of the present invention.

FIG. 2 is a diagonal sectional view showing a configuration of a lens array plate according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining the operation of the lens array plate according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a cross-sectional shape of a light beam at a focal point of a lens element of the lens array plate shown in FIGS. 1 and 2;

FIG. 5 is a plan view showing a configuration of a modified example of the lens array plate according to the first embodiment of the present invention.

FIG. 6 is a diagonal sectional view showing a configuration of a lens array plate according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a configuration of a light valve device according to a third embodiment of the present invention.

FIG. 8 is a schematic configuration diagram illustrating a configuration of a black matrix of a light valve device according to a third embodiment of the present invention.

FIG. 9 is a schematic configuration diagram illustrating a configuration of a projection display device according to a fourth embodiment of the present invention.

FIG. 10 is a schematic configuration diagram illustrating a configuration of a viewfinder device according to a fifth embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a configuration of a conventional light valve device in which a lens array plate and a TFT liquid crystal panel are combined.

FIG. 12 is a diagram for explaining the operation of the lens array plate shown in FIG. 11;

FIG. 13 is a diagram showing an effective area of a lens element of the lens array plate shown in FIG. 11;

FIG. 14 is a diagram for explaining the operation of the lens array plate shown in FIG. 11;

[Explanation of symbols]

51, 55, 81, 85 Glass substrate 52, 82 Resin layer 53, 83 Lens element 54, 84 Adhesive 59, 89 Spherical surface 61, 91 Conical surface 101 Liquid crystal panel 102 Lens array plate 103 Adhesive 104, 105, 119 Glass substrate 114 Black matrix 116 Pixel 120 Resin layer 122 Lens element 126 Spherical surface 128 Conical surface 141 Light source 146, 147 Dichroic mirror 148, 152, 154 Planar mirror 149, 150, 155 Field lens 151, 153 Relay lens 156, 157, 158, 162 163, 164 Polarizing plate 159, 160, 161 Light valve device 165 Color combining prism 172 Projection lens 182, 183, 184 LED 185 Color combining prism 191 Condensing lens 192 Light valve Location 193, 194 polarizer 197 eyepiece

Claims (8)

[Claims] A plurality of lens elements arranged in a matrix, wherein an effective area of the lens elements is square or rectangular; and a lens surface of each lens element is located at a center of the lens surface. A spherical surface or a rotationally symmetric aspheric surface that generates a positive refractive power, and a conical surface that generates a positive refractive power disposed around the spherical surface or the rotationally symmetric aspherical surface. The boundary between the spherical surface and the conical surface is one or more arcs forming a part of the circumference of one circle or the circumference of one circle, and the spherical surface or the rotationally symmetric aspheric surface and the conical surface Is a lens array plate that is connected smoothly. 2. The lens array plate according to claim 1, wherein a center of said one circle and a center of said effective area coincide with each other for each of said lens elements. 3. The lens element according to claim 2, wherein the effective area of the lens element has a square shape, and a diameter of the circle is equal to a width of the lens element or an arrangement pitch of the lens element. Lens array plate. 4. The lens array plate according to claim 1, further comprising: a light valve in which a plurality of pixels corresponding to each of the lens elements are arranged in a matrix. A light valve device, which is arranged on an incident side of the light valve, wherein an optical axis of each lens element passes through a center of the corresponding pixel. 5. The light valve device according to claim 4, wherein the focal point of the spherical surface or the rotationally symmetric aspheric surface of each lens element is located at or near the center of the pixel. 6. The focal length of the spherical surface or the rotationally symmetric aspheric surface of each lens element is from 1.5 times to 3 times the air equivalent distance from the vertex of the lens element to the center of the pixel.
The light valve device according to claim 4, wherein the light valve device is in a double range. 7. A light valve according to claim 4, wherein the light emitted from the light source is emitted as an optical image in accordance with a video signal, and the light emitted from the light valve is emitted from the light valve. A projection lens for enlarging and projecting the optical image on a screen. 8. A light valve according to claim 4, wherein the light emitted from the light source is emitted as an optical image according to a video signal, and the light emitted from the light valve is emitted from the light valve. A viewfinder device comprising: an eyepiece that allows the optical image to be observed.