JP2000250030A - Nearly parallel light projecting means and projection type liquid crystal display device using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the power efficiency of a lamp by arranging prism sheets which have many microprisms arrayed between a light source and a liquid crystal panel and projecting video on a screen by an erect image forming means. SOLUTION: The prism sheets 14a and 14b which have many microprisms arrayed are arranged between a light source and liquid crystal panel and video is projected on a screen by an erect image forming means. The mechanisms are preferably in a triangular, a trapezoidal, a polygonal, a triangularly-conic, a pyramidal, a circularly-conic, a frustum-of-cone, a semicylindrical, a hair-line, a stained shape or the like. Then the projection type liquid crystal display device which constitutes a large-size projection device comprises a nearly parallel light irradiation means 41, a liquid crystal panel which has a driver IC or the like arranged at the periphery of a liquid crystal pixel part in a frame shape and convex lens arrays (1st lens array), convex lens arrays (2nd lens array), a Fresnel concave lens and a screen which are used as the erect image forming means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a rear projection type liquid crystal display device suitable for large-screen display.

[0002]

2. Description of the Related Art In a conventional large-screen projection video apparatus using a liquid crystal projector or a CRT projector, a long projection distance is required to greatly enlarge an image displayed on a liquid crystal panel or a CRT. growing. In addition, as a display with a thin depth, conventionally, PD
P is also available, but is expensive.

A conventional technique for shortening the set depth of a projection apparatus by greatly shortening the projection distance by using an erect image forming means such as a lens array is disclosed in Japanese Unexamined Patent Publication No. Hei.
188340 (hereinafter referred to as prior art A)
There is. In the prior art A, in order to prevent each lens transmitted light in the lens array from deviating from a predetermined optical path,
A substantially parallel light irradiating means for making the illumination light substantially parallel within a predetermined angle is used.

[0004] However, any of those employed as the substantially parallel light irradiation means has a problem that the lamp power efficiency is inferior and the projected image is very dark or requires a very large lamp power. It also implies that this problem cannot be solved without reducing lamp efficiency or using large lamp power.

[0005] Therefore, the lamp power efficiency required for realizing a bright screen is the performance that is most important in large-screen video equipment products, but the problem with the prior art A is that the lamp power efficiency is inferior. Can not.

[0006] Several years after the publication of the prior art A, a technique aimed at improving the above-mentioned problem by two inventors of this technique is described in "FUJITSU.47.4 / 07, 1".
996, LCD multi-panel display, p352-3
56 (hereinafter referred to as conventional technology B).
However, the lamp power efficiency is still not sufficient. Also, as a large-screen video device product used indoors, the reduction of the depth of the device is not sufficient.

Japanese Patent Application Laid-Open No. 6-051142 discloses an image display device in which a prism sheet for improving a viewing angle characteristic is arranged between a screen and an assembly of optical fibers for enlarging an optical image. (Hereinafter referred to as conventional technology C). In the prior art C, since the optical image is enlarged by using the optical fiber, the depth dimension of the image display device becomes long. Nothing is said about improving lamp power efficiency.

[0008]

As described above, the prior arts A, B, and C of the projection type liquid crystal display device using the erect image forming means such as a lens array are the most important in a large-screen image device product. Lamp power efficiency is not sufficient,
There are two problems that the depth of the device is not sufficiently reduced as a large-screen image device product used indoors.

It is an object of the present invention to provide a projection type liquid crystal display device using erect image forming means with improved power efficiency of a lamp. It is another object of the present invention to provide a projection-type liquid crystal display device using erect image forming means with a reduced depth dimension of the device.

[0010]

According to the present invention, as a substantially parallel light irradiating means for a projection type liquid crystal display device utilizing an erect image forming means such as a lens array, a light beam emitted from a light source is transmitted in one direction or a plurality of directions. Direction, or an edge light guide that converts and emits a light flux that shows a luminance peak within a certain angle range, or a concave mirror or a cylindrical concave mirror, or a lens or a Kamaboko Fresnel lens, or a concave mirror or a cylindrical concave mirror and a lens; Beam direction changing means such as combination with Kamaboko Fresnel lens, and
In addition to the prism sheet or prism plate on which minute irregularities such as triangles, trapezoids, polygons, triangular pyramids, polygonal pyramids, cones, truncated cones, semicircles, hair lines, and satin mats are arranged, from the combination of light sources and unnecessary light removing means Use what constitutes.
Further, in the present invention, a uniform illuminating means including at least one lens plate in which a plurality of rectangular lenses are arranged in a matrix or in parallel, or a metal thin film such as AL is formed in a mosaic shape, a mesh shape or the like, thereby reflecting light. Surface and transmissive surface are mosaic, uniform illumination means consisting of a transparent plate formed in a distribution such as a mesh, or triangle, trapezoid, polygon, triangular pyramid, polygonal pyramid, cone, truncated cone, truncated cone, A uniform illuminating means composed of a prism sheet or a prism plate on which minute uneven surfaces such as a hairline and satin are arranged is arranged between the light source and the transmission type liquid crystal panel.

In order to achieve the object of the present invention, a projection type liquid crystal display device according to the present invention has a prism sheet in which a large number of micro prisms are arranged between a light source and a liquid crystal panel, and is formed on a screen by erect image forming means. Project the image. It is preferable that the micro prism is formed in a shape such as a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a semi-cylindrical shape, a hairline, and a satin finish.

Further, the projection type liquid crystal display device according to the present invention provides a light source and a light beam emitted from the light source in one direction, a plurality of directions,
An edge light guide for converting into a light flux showing a luminance peak in any of a certain angle range, a liquid crystal panel, a prism sheet disposed between the light source and the liquid crystal panel, and arranged with a large number of micro prisms, Erect image forming means for erect image formation of an image on the liquid crystal panel on a screen.

Further, a projection type liquid crystal display device according to the present invention is provided with a light source, a light beam direction changing means for changing the direction of light from the light source, a liquid crystal panel, and a light source and the liquid crystal panel. It comprises a prism sheet in which a number of micro prisms are arranged, and erect image forming means for erectly forming an image of a liquid crystal panel on a screen. The light beam direction changing means includes a concave mirror, a cylindrical concave mirror, a lens, a Kamaboko Fresnel lens, a combination of a concave mirror and a lens, a combination of a cylindrical concave mirror and a lens, a combination of a concave mirror and a Kamaboko Fresnel lens, a cylindrical concave mirror and a Kamaboko Fresnel. It is constituted by any combination of lenses. Further, the erecting imaging means may include any one of a plurality of convex lens arrays, a flat microlens array as a refractive index distributed lens array, a self-occurring lens array, a rod type microlens array, and a bent distribution optical fiber bundle. It is configured using.

[0014] In these projection type liquid crystal display devices, it is preferable that an unnecessary light removing means is provided to remove a part of the light beam emitted from the prism sheet. The unnecessary light removing means is constituted by arranging either a polygonal hole or a round hole in a close-packed arrangement. The edge light light guide, one or both of the exit surface and the back surface, triangular, trapezoidal, polygonal, triangular pyramid, polygonal pyramid, cone, truncated cone, semi-cylindrical, hair line, one of the fine convex surface of matte Edge light light guide with a flat exit surface, edge light light guide with a light scatterer dispersed inside, edge light light guide with a light scatterer printed on the back, hollow inside It is preferable to use any one of the edge light light guide described above and an edge light light guide formed by laminating a plurality of transparent plates. Further, it is preferable that the light source is disposed on a side end surface of the edge light guide. Further, the light source is any one of a hot cathode tube, a cold cathode tube, and a fluorescent tube, and it is preferable to arrange one or more layers.

In these projection type liquid crystal display devices, a polarization converter is provided, and the polarization converter is arranged between the light source and the edge light guide. Preferably, the light beam direction changing means is a combination of a concave mirror and a lens, and the lens preferably uses any one of a convex lens, a convex kamaho lens, and a convex kamaho Fresnel lens. Further, the light source is constituted by a fluorescent tube which is any one of a hot cathode tube, a cold cathode tube double tube and the like, and the light beam direction changing means is a cylindrical concave mirror,
A cylindrical concave mirror such as a rectangular cylinder concave mirror, an elliptical cylindrical concave mirror, a hyperbolic cylindrical concave mirror, or a non-spherical cylindrical concave mirror may be used. The light source may be a point light source such as a miniature lamp, and the light beam direction changing means may be a concave mirror such as a spherical concave mirror, a parabolic concave mirror, an elliptical concave mirror, a hyperbolic concave mirror, or an aspheric concave mirror. Further, in these projection type liquid crystal display devices, it is preferable that the liquid crystal panel is constituted by a transmission type liquid crystal panel and an enlargement projection unit for enlarging a light image from the transmission type liquid crystal panel is provided. It is preferable that a driver IC or the like is arranged in a frame shape around the pixel portion of the transmissive liquid crystal panel. Further, it is preferable that an enlargement projection unit for enlarging the light image of the liquid crystal panel is provided, and the enlargement projection unit is constituted by a Fresnel concave lens. It is further preferable that the liquid crystal panel is constituted by a transmission type liquid crystal panel, and a reflection type polarization separation film is provided between the light source and the transmission type liquid crystal panel.

In these projection type liquid crystal display devices, a uniform illuminating means comprising a lens plate in which a plurality of rectangular lenses are arranged in a matrix or in parallel is provided, and the uniform illuminating means is provided between the light source and the prism sheet. It is preferable to arrange them. The light source is a linear light source of a cold cathode tube having a diameter of 3 mm or less. In these projection type liquid crystal display devices, it is preferable that a polarization converter is provided, the liquid crystal panel is constituted by a transmission type liquid crystal panel, and the polarization converter is arranged between the light source and the transmission type liquid crystal panel.

In these projection-type liquid crystal display devices, the metal thin film forms a mosaic pattern, a mesh pattern, or the like, so that the reflection surface and the transmission surface are formed in a mosaic pattern, a mesh pattern, or the like. It is preferable that a uniform illuminating means made of a plate is provided, the liquid crystal panel is constituted by a transmissive liquid crystal panel, and the uniform illuminating means is arranged between the light source and the transmissive liquid crystal panel. In these projection type liquid crystal display devices, a uniform illuminating means comprising a prism sheet having a plurality of minute prisms having a shape such as a triangle, a trapezoid, a polygon, a triangular pyramid, a pyramid, a cone, a truncated cone, a truncated cone, a hairline, and a satin finish. And the liquid crystal panel is constituted by a transmissive liquid crystal panel, and is disposed between the light source and the transmissive liquid crystal panel. In these projection-type liquid crystal display devices, the prism sheet is constituted by a plurality of micro prisms having a shape such as a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a trapezoid, a hairline, and a satin finish. The liquid crystal panel is constituted by a transmissive liquid crystal panel, and the prism sheet is disposed between the light source and the transmissive liquid crystal panel.

The projection type display device according to the present invention has a prism sheet in which a number of micro prisms are arranged between a light source and a liquid crystal panel, and the projection type liquid crystal display device which projects an image on a screen by erect image forming means is arranged vertically and horizontally. A plurality of the images are arranged and projected on the same screen, and a continuous image without any seam is displayed on the same screen.

Further, the projection display apparatus according to the present invention comprises a light source, an edge light guide for converting a light beam emitted from the light source into a light beam showing a peak of luminance, a liquid crystal panel, and a liquid crystal panel. A plurality of projection-type liquid crystal display devices, which are arranged between them and have a prism sheet in which a large number of micro prisms are arranged, and erect image forming means for erectly forming an image of a liquid crystal panel on a screen, are arranged vertically and horizontally and projected on the same screen. Then, seamless images are displayed on the same screen.

Further, the projection display apparatus according to the present invention is provided with a light source, a light beam direction changing means for changing the direction of light from the light source, a liquid crystal panel, and a microscopic device disposed between the light source and the liquid crystal panel. A plurality of projection type liquid crystal display devices including a prism sheet in which a number of prisms are arranged, and erect image forming means for erectly forming an image of a liquid crystal panel on a screen are arranged vertically and horizontally, and projected on the same screen to form a seamless continuous screen. The image is displayed on the same screen.

In these projection type liquid crystal display devices, the liquid crystal panel is constituted by a transmission type liquid crystal panel, and the number of pixels of the transmission type liquid crystal panel is set to (VGA, SVGA, X
The number of pixels according to the pixel number standard such as GA, SXGA, UXGA, etc./(the total number of projection type liquid crystal display devices) + the number of pixels required for the above-mentioned overlapping portions. In these projection type liquid crystal display devices, the prism sheet has a triangular shape,
Trapezoidal, polygonal, triangular pyramid, polygonal pyramid, cone, truncated cone, semi-cylindrical, hairline, satin, etc.It is a substantially parallel light irradiation means having a plurality of minute prisms, and the liquid crystal panel is constituted by a transmission liquid crystal panel Then, the substantially parallel light irradiation means is disposed between the light source and the transmission type liquid crystal panel.

The direct-view type liquid crystal display device according to the present invention comprises a light source, a transmissive liquid crystal panel, a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a truncated cone, a hairline, a satin finish and the like. A prism sheet having a plurality of micro prisms, wherein the prism sheet is used as uniform illumination means or as substantially parallel light irradiation means, or as both uniform illumination means and substantially parallel light irradiation means, and the light source and the transmission type liquid crystal are used. It is placed between the panels.

The front projection type liquid crystal display device according to the present invention comprises a light source, a transmission type liquid crystal panel, a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a truncated cone,
Hair line, a prism sheet having a plurality of micro prisms in the shape of satin, etc., the prism sheet,
The light source is disposed between the light source and the transmissive liquid crystal panel as uniform illumination means or substantially parallel light irradiation means, or as both uniform illumination means and substantially parallel light irradiation means.

The substantially parallel light irradiating means according to the present invention comprises a light source and an edge light guide for converting a light beam emitted from the light source into a light beam having a luminance peak in one direction, a plurality of directions, or within a certain angle range. And a prism sheet on which a number of micro prisms are arranged.

The substantially parallel light irradiating means according to the present invention includes a light source, a light beam direction changing means for changing the direction of light from the light source, and a prism sheet on which a number of micro prisms are arranged. In these substantially parallel light irradiation means, an unnecessary light removing means is provided to remove a part of the light beam emitted from the prism sheet. The micro prism is triangular, trapezoidal,
It is a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a truncated cone, a hairline, or a satin finish. Further, the unnecessary light removing means is configured by arranging holes such as polygonal holes and round holes in a close-packed manner.

Further, the light beam direction changing means includes a concave mirror,
One of cylindrical concave mirror, lens, Kamaboko Fresnel lens, combination of concave mirror and lens, combination of cylindrical concave mirror and lens, combination of concave mirror and Kamaboko Fresnel lens, combination of cylindrical concave mirror and Kamaboko Fresnel lens . In this substantially parallel light irradiation means, a polarization converter is provided, and the polarization converter is arranged between the light source and the edge light guide. Further, in the substantially parallel light irradiation means, the light beam direction changing means is a combination of a concave mirror and a lens, and the lens uses any one of a convex lens, a convex lens, and a convex Fresnel lens.

The edge light guide may include a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a truncated cone, a hairline,
Edge light guide with a slightly convex surface such as satin finish, edge light guide with a flat exit surface, edge light guide with light scatterer dispersed inside, edge light with light scatterer printed on the back One of a light guide, an edge light guide having a hollow inside, and an edge light guide formed by laminating a plurality of transparent plates. Further, the light source is constituted by a fluorescent tube which is any one of a hot cathode tube, a cold cathode tube double tube and the like, and the light beam direction changing means is a cylindrical concave mirror,
It is a cylindrical concave mirror such as a rectangular cylinder concave mirror, an elliptical cylindrical concave mirror, a hyperbolic cylindrical concave mirror, or a non-spherical cylindrical concave mirror.

In these substantially parallel light irradiation means, a reflection type polarization separation film was provided. Further, in this substantially parallel light irradiation means, a uniform illumination means comprising a lens plate in which a plurality of rectangular lenses are arranged in a matrix or in parallel is provided, and the uniform illumination means is arranged between the light source and the prism sheet. . In this substantially parallel light irradiation means, the metal thin film forms a pattern such as a mosaic shape or a mesh shape, so that the reflection surface and the transmission surface are formed of a transparent plate formed in a mosaic shape or a mesh shape distribution. It is preferable to provide lighting means. Further, the prism sheet has a plurality of small prisms having a shape such as a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a phantom, a hairline, and a satin finish. It is. In addition, the prism sheet has a plurality of micro prisms having a shape such as a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a semicircular shape, a hairline, and a satin finish. It is preferable that it also serves as a means.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to the drawings using examples. FIG. 1 is a perspective view showing a first embodiment of a substantially parallel light irradiation means used in a projection type liquid crystal display device according to the present invention. FIG. 2 is a schematic diagram showing one embodiment of a large-sized projection device in which some of the projection-type liquid crystal display devices according to the present invention are arranged. FIG. 3 is a schematic view showing one embodiment of the projection type liquid crystal display device according to the present invention. The substantially parallel light irradiation means shown in FIG. 1 is a component of the projection type liquid crystal display device 1 shown in FIGS. 2 and 3, and will be described later in detail.
As shown in FIG. 2, the large projection device 2 is configured by arranging a plurality of projection type liquid crystal display devices 1 shown in FIG. On the screen 3 shared by the plurality of projection type liquid crystal display devices 1, only the image of the liquid crystal panel built in each of the projection type liquid crystal display devices 1 is projected, and the gap 4 between the liquid crystal panels is projected.
, A seamless large-screen image is formed, and the number of pixels of the entire screen on the screen 3 of the large-size projection device 2 is set to SX.
GA.

As shown in FIG. 3, an outline of the projection type liquid crystal display device 1 constituting the large projection device 2 shown in FIG. Liquid crystal panel 5 arranged, a plurality of convex lens arrays (first lens array) 6 used as erect image forming means
a, a convex lens array (second lens array) 6 b, a Fresnel concave lens 7 and the screen 3.

Since the substantially parallel light irradiation means 41 emits substantially parallel illumination light, the image 8 of the liquid crystal panel 5 is formed as an inverted image 9 by the first lens array 6a. Next, an image is formed as the erect image 10 by the second lens array 6b. When the erect image 10 is formed, the lens arrays 6a and 6b
Light rays passing through adjacent lenses inside overlap each other, and form an entire image of the liquid crystal panel 5 as an erect image 10 as an entire lens array. Then, the Fresnel concave lens 7 projects the erect image 10 on the screen 3 in an enlarged manner, so that an enlarged image 11 is formed.

The main part of the substantially parallel light irradiation means 41 shown in FIG. 3 is constructed as shown in FIG. The substantially parallel light irradiation means 41 includes cold cathode tubes 12a and 12b as light sources, edge light guides 13 and edge light guides 1 as light flux direction changing means.
The prism sheet 14a disposed on the third side, the prism sheet 14b disposed on the unnecessary light removing unit 15 side, and the reflection sheet 1
6. Prism sheets 14a, 14b
Are formed in parallel with micro triangular prisms, and the arrangement direction of the prisms on the prism sheet 14a is the same as the long axis direction (perpendicular to the plane of the drawing) of the cold cathode tubes 12a and 12b. The arrangement direction of the prisms is formed orthogonal to the direction, and the prism sheet 14
a and 14b are arranged so as to overlap each other so that the arrangement directions of the prisms are orthogonal to each other.

FIG. 4 is a conceptual diagram for explaining the operation of the edge light guide and prism sheet of the substantially parallel light irradiation means of FIG. As shown in FIG.
Is formed flat, and a rear surface 18 is formed with a slightly convex surface 19a. The surface 19b between the adjacent minute convex surfaces 19a is configured to be flat. The cold cathode tube 12 installed on the left end surface 20a side of the edge light guide 13
A light beam 21a emitted from a enters the edge light guide 13 after irradiating the side end surface 20a. The angle of incidence of most of the light entering the edge light guide 13 is such that the light enters the exit surface 17 and the back surface 18 of the edge light guide 13 at an angle greater than the critical angle. The thickness is set thin.

For this reason, the light beam emitted from the cold cathode tube 12 a repeats total reflection between the light exit surface 17 and the rear surface 18, and travels deep inside the edge light light guide 13. On the way, back 1
When the light that has reached the emission surface 17 at a critical angle or less out of the light reflected by the minute convex surface 19a provided on the light emission surface 8 is emitted from the emission surface 17, the light flux 22 shown by the arrow in FIG. As can be seen from the luminous flux shown, the light is converted and emitted so as to show a luminance peak in one specific direction. Similarly, the luminous flux 21b emitted from the cold cathode tube 12b installed on the right end face 20b side of the edge light guide 13 is also the luminous flux 2 shown by an arrow.
As can be seen from 3 and the light flux indicated by the arrows on both sides thereof, the light is converted and emitted in one direction symmetrical to the above-mentioned specific one direction.

By such a light guiding action of the edge light light guide 13, the light fluxes 21a, 21b emitted from the cold cathode tubes 12a, 12b installed on the left and right end faces 20a, 20b.
Are luminous fluxes 22, 2 indicated by arrows when viewed in a cross section on the optical path.
As can be seen from FIG. 3, the light is converted into bilaterally symmetrical light fluxes 22 and 23 which show luminance peaks in two specific directions, and becomes light emitted from the surface light source from each part of the exit surface 17 of the edge light guide 13. To the prism sheet 14a.

Each of the light beams 22 and 23 indicated by the thick arrows is
At a certain point, a representative ray whose luminance is peaked in a light beam having a certain angular width in the emission direction, or an angle of the emission direction in a light beam having a certain angular width in the emission direction indicates an average value of the angular width. Represents a representative ray. (In FIG. 4 and subsequent figures, a bold arrow indicates a similar representative light beam.) A light beam 22 of the bold arrow indicates a representative light beam directed to the right surface 25 of the prism, and a light beam 23 of the bold arrow indicates the left light of the prism. Represents a representative light beam directed to the surface 27 of FIG.

In this embodiment, the total reflection is repeated between the flat light exit surface 17 and the flat surface 19b of the rear surface 18, and the amount of light traveling to the far side inside the edge light guide 13 and the light reflected by the minute convex surface 19a are emitted. The amount of light emitted from the surface 17 is
Each part of the edge light guide 13 is controlled so that the light exit surface 17 is controlled.
After exiting from the liquid crystal panel 5 (see FIG. 3) via the prism sheets 14a and 14b (see FIG. 1).
In order to equalize the amount of light toward the entire surface of the emission surface 17, the shape of the minute convex surface 19a formed on the back surface 18 is made appropriate, and at the same time, the distance between the minute convex surfaces 19a forming the flat surface 19b is adjusted. Are appropriately changed according to the distance from the cold cathode tubes 12a and 12b. For this reason, uniform illumination for equalizing the illuminance of each part of the entire surface of the liquid crystal panel 5 has become possible, and uniformization of the luminance distribution of each part of the enlarged image 11 on the screen 3 has been realized.

In the present embodiment, d 1 is a close distance, and indicates a distance between the w-plane and the light exit surface 17 of the edge light guide 13. During this close interval, the prism sheet 14a
The light source side surface 28 is disposed. Here, the w surface is a surface formed by a line connecting between the valley bottoms of the adjacent prisms or, when the peaks of the prisms face the light source side, between the ridges of the adjacent prisms. As shown in the figure, the distance between the three surfaces of the w surface, the light source side surface 28 of the prism sheet 14a, and the emission surface 17 of the edge light guide 13 is close.

For this reason, the exit surface 17 within the width of the w-plane
As many rays as possible in the bidirectional light beams 22 and 23 passing through the upper representative point k (for example, near the midpoint of the prism width)
It can be reached within the right face 25 or the left face 27 of the closest opposing prism.

In this embodiment, attention is paid to the fact that the light beams 22 and 23 emitted from the edge light guide 13 show a luminance peak in one or a plurality of directions at a predetermined angle, and the light beams in the two directions (the light beams indicated by bold arrows) are used. 22 and 23) are refracted or totally reflected by a predetermined surface of the prism and exit from the surface 25 or 27 of the prism so that they exit in the same optical axis 24 direction. And the height t of the prism are designed to predetermined values.

Therefore, when exiting from the edge light guide 13, the light fluxes 22 and 23 indicated by thick left and right symmetrical arrows indicating luminance peaks in two specific directions are emitted from the prism sheet 14 a. Can be converted into luminous fluxes 29 and 30 indicated by bold arrows indicating the luminance peak in the same direction as the optical axis 24. In this embodiment, two prism sheets 14a and 1
Since the prism arrangement directions of 4b (see FIG. 1) are orthogonal to each other, the above conversion also occurs in the prism sheet 14b. Therefore, the above-described conversion occurs in both the long axis direction and the orthogonal direction of the cold cathode tubes 12a and 12b.

In this embodiment, the prism sheets 14a and 14b having the prisms designed as described above are arranged
The following two things are achieved by arranging the edge light guide 13 close to the emission surface 17. That is, (1) a light beam passing through the representative point k on the emission surface 17 within the width of the w surface of the edge light light guide 13 close to the w surface (the light source 12
a, 12b), as much as possible from the w-plane close to the exit surface 17 so as to reach the nearest prism surface 25 or 27 and be refracted or reflected. (2) The prism surface 25 or 27 can be controlled efficiently by the light source 12
a and 12b as much as possible incident angles that can contribute to imaging (the maximum incident angle of light passing through the lens and contributing to imaging; FIG. The liquid crystal panel 5 is made into a substantially parallel light beam in
(See FIG. 3).

In the projection type liquid crystal display device shown in FIG. 3, in order to shorten the projection distance, light is condensed, projected and formed by using lens arrays 6a and 6b composed of small-diameter convex lenses having a diameter on the order of mm and a Fresnel concave lens 7. The statue is going.

The unnecessary light removing means 15 shown in FIG.
It can be configured as shown in FIGS.

FIG. 5A is a plan view showing one embodiment of the unnecessary light removing means, and FIG. 5B is a plan view showing another embodiment of the unnecessary light removing means. FIG. 6 is a sectional view of the unnecessary light removing means. The unnecessary light removing means 15 is provided on a flat plate made of a light absorber (black material) having a predetermined thickness, as shown in FIG.
A large number of square holes are arranged in a close-packed arrangement,
As shown in (b), a large number of circular holes can be used in a close-packed arrangement. The unnecessary light removing means 15 is provided in FIG.
As shown in the figure, light with an incident angle of 0 to ± θ is transmitted, but light with an incident angle of θ to 90 degrees or -θ to -90 degrees hits a hexagonal hole or a circular wall surface and is absorbed. I have to. The unnecessary light removing unit 15 is provided on the exit side of the prism sheet 14b.

Further, in the total liquid crystal panel 5 of the plurality of projection type liquid crystal display devices 1 constituting the large projection device 2, the number of pixels of the entire screen on the screen 3 may be SXGA, so that one liquid crystal panel The number of pixels of 5 is obtained from the following equation.
Therefore, the aperture ratio of the liquid crystal panel 5 can be increased. The number of pixels of the liquid crystal panel = (the number of pixels according to the pixel number standard such as VGA, SVGA, XGA, SXGA, and UXGA) / (the number of projection type liquid crystal display devices 1 that project onto the screen 3) + the number of pixels required for overlapping portions. (Equation 1) By using a plurality of the projection type liquid crystal display devices 1 configured as described above and configuring a large projection device 2 as shown in FIG. By projecting only the image 8 of the liquid crystal panel 5 built in the liquid crystal display device 1, a continuous large-screen image 11 without the gap 4 between the liquid crystal panels 5 can be obtained. At this time, a part of the image 8 of the adjacent liquid crystal panel 5 overlaps with each other. The brightness of the overlapping portion is adjusted by an electronic circuit (not shown) so that the connecting portion does not look unnatural on the screen. As a result of configuring the projection type liquid crystal display device 1 as described above, the large projection device 2 of the present embodiment can greatly reduce the depth as compared with the conventional technology B, and the lamp power efficiency of the conventional technologies A and B is inferior. Problems can be greatly improved.

In this embodiment, one of the images 8 of the liquid crystal panel 5 built in the adjacent projection type liquid crystal display device 1 is used.
However, the brightness of the gap 4 between the liquid crystal panels 5 and the brightness of the non-opening (not shown) between the pixels in the liquid crystal panel 5 are the same on the screen 3. If it is possible to actually make it seem that there is no gap between the liquid crystal panels 5, a part of the image 8 of the liquid crystal panel 5 may be projected without overlapping.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. FIG. 7 is a side view showing a second embodiment of the substantially parallel light emitting means used in the projection type liquid crystal display device according to the present invention. The luminous flux emitted from the light source usually includes p-polarized light and s-polarized light. For this reason, in the first embodiment, half the polarized light in the light flux emitted from the light sources 12a and 12b is absorbed by the polarizing plate (not shown) in the liquid crystal panel 5 and is not used. In order to utilize the polarized light lost in the polarizing plate in the liquid crystal panel 5, in the second embodiment, as shown in FIG.
A substantially parallel light irradiating means 42 was formed by adding a reflection type polarization separating film 31 between the prism sheet 14b and the unnecessary light removing means 15. Portions other than the substantially parallel light irradiation means 42 are the same as those of the first embodiment, and are configured as shown in FIG. The polarized light separating film 31 in FIG. 7 is composed of a two-layer film of a cholesteric liquid crystal film and a quarter-wave plate film, for example, a polarized light separating film (trade name, “Transmax”) manufactured by Merck Japan Ltd. It has been known.

The polarization separation film 31 is
4b, by installing on the emission side surface,
Light having the same polarization component as the polarizing plate of the liquid crystal panel 5 is transmitted and sent to the liquid crystal panel 5 (shown in FIG. 3). On the other hand, light of a polarization component orthogonal to the polarizing plate of the liquid crystal panel 5 is reflected by the polarization separation film 31, and the prism sheet 14a,
The light returns to the edge light guide 13 via 14b, is reflected again by the back surface 18 of the edge light guide 13 and the reflection sheet 16, and returns to the polarization separation film 31 side. In this way, the light that was initially a light having a polarization component orthogonal to the polarizing plate of the liquid crystal panel 5 is converted into light having the same polarization component as that of the polarizing plate of the liquid crystal panel 5 in the reflection process, and The liquid crystal panel 5 can be transmitted through the separation film 31.
Participation in irradiation. Thus, the lamp power efficiency can be improved in the second embodiment more than in the first embodiment.

Next, a third embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention will be described with reference to FIG. FIG. 8 is a side view showing a third embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention. As shown in FIG. 8, in the present embodiment, between the light sources 12a and 12b and the edge light light guide 13, two rectangular prisms and a polarization separation film formed on a joint surface between the prisms are formed. A substantially parallel light irradiating means 43 was configured by adding a PBS (polarizing beam splitter) 32, a λ / 2 plate 33, and a mirror. Except for the substantially parallel light irradiation means 43, the configuration is the same as that of the first embodiment. PB
The combination of S32, the λ / 2 plate 33, and the mirror 34 is usually called a polarization converter.

In this embodiment, the PBS 32 and the λ / 2 plate 33
Since the substantially parallel light irradiation means 43 is configured by adding the mirror 34, not only p-polarized light (or s-polarized light) but also s-polarized light (or p-polarized light) can be effectively used. Therefore, the substantially parallel light irradiation means 43 of the present embodiment can improve the lamp power efficiency more than the substantially parallel light irradiation means 42 shown in the second embodiment.

As the edge light guide 13, (a)
In addition to the flat and parallel output surfaces and the back surface adopted in the first to third embodiments, (b) the front and back surfaces have a wedge-like shape, (c) the back surface has a curved shape, (D)
A flat surface with a light scatterer (ink containing an inorganic filler such as titanium white or barium sulfate) printed in a dot or stripe pattern, and (e) a light scatterer in an edge light guide. (Inorganic fine particles such as calcium carbonate, silica, glass beads, and nylon fine particles) and a light-scattering polymer, (f) a hollow hollow inside of an edge light guide for weight reduction, (g)
(H) a prism function is applied to one or both of the exit surface and the back surface of the edge light guide to integrate the functions of the prism sheet and the edge light guide. Triangles, trapezoids, polygons, triangular pyramids, polygonal pyramids, cones, truncated cones, semi-cylindrical shapes, hair lines, matte-finished surfaces, and the like.

In the present invention, various combinations of the edge light guide 13 from among the above (a) to (h) may be employed as appropriate. When one or both of the emission surface 17 and the back surface 18 of the edge light guide 13 are formed with the minute convex surface 19a having a prismatic action, the number of prism sheets used may be one or zero.

In the first to third embodiments, the left and right end surfaces 20a, 20a of the edge light light guide 13 are provided.
Although the cold cathode tubes 12a and 12b arranged in two layers are used for b, in the present invention, cold cathode tubes may be arranged as shown in FIGS. 9 (a) to 9 (c).

FIG. 9A is a side view showing an embodiment of the arrangement of the edge light guide and the cold cathode tube, FIG. 9B is a plan view thereof, and FIG. 9C is an edge light guide. And FIG. 9D is a plan view showing still another embodiment of the arrangement of the edge light guide and the cold cathode tube. 9 (a) and 9 (b), the cold cathode tubes 12 are arranged on one side surface of the edge light light guide 13 ', and in FIG. 9 (c), the cold cathode tubes 12 are arranged on both side surfaces of the edge light light guide 13'. A cold cathode tube 12 is provided, and in FIG. 9D, the cold cathode tube 12 is provided on the four end surfaces of the edge light guide 13 '. Naturally, these cold cathode tubes 12 may be arranged in one or more layers.

As described in the first embodiment, noting that the light beams 22 and 23 emitted from the edge light guide 13 show a luminance peak in one or more specific directions, the luminance in the emitted light beam is considered. When the representative luminous fluxes 22 and 23 exhibiting peaks are refracted or totally reflected on a predetermined surface of the prism and are emitted from the predetermined surface 25 or 27 of the prism, they are directed in the same optical axis 24 direction. By arranging the prism sheets 14a and 14b in which the prism angles (α and β in FIG. 4) and the height t are set to predetermined values so as to be close to the exit surface 17 of the edge light light guide 13, (1) The emission surface 17 of the edge light light guide 13 facing the w surface or the w surface formed by a line connecting the valley bottoms of the adjacent prisms (or the peaks of the prisms) of the prism sheet 14a. Luminous flux passing through upper representative point k (Light fluxes coming from the light sources 12a and 12b) reach the prism surface 25 or 27 closest to the w surface as much as possible from the w plane, and are refracted or reflected to efficiently control the light flux direction. To do
(2) The surfaces 25 or 27 of the prism are the light sources 12a and 12b
From the liquid crystal panel 5 as much as possible parallel light rays within an effective angle θ on the incident angle that can contribute to the image formation.

Substantially the same as the above (1) and (2) is also possible by a combination of a light beam direction changing means other than the edge light guide and a prism sheet. Hereinafter, the embodiment will be described with reference to the drawings.

FIG. 10A is a side view showing a fourth embodiment of the substantially parallel light irradiating means used in the projection type liquid crystal display device according to the present invention, and FIG. It is a perspective view showing one example. FIG. 10 (a), FIG.
As shown in (b), the substantially parallel light irradiating means 44 includes a cylindrical concave mirror, a rectangular parallelepiped concave mirror, an elliptic cylindrical concave mirror, a hyperbolic cylindrical concave mirror, or an aspherical cylindrical concave mirror as a light flux direction changing means. It is configured by using the concave mirror 36, setting the interval between the cylindrical concave mirror 36 and the prism sheets 14a and 14b to a predetermined value, and combining the cold cathode tube 12, the prism sheets 14a and 14b, the polarization separation film 31, and the unnecessary light removing means 15. Is done. The projection type liquid crystal display device has the same configuration as that of the first embodiment except for the substantially parallel light irradiation means 44.

In this embodiment, the cylindrical concave mirror 36 used for the light beam direction converting means converts one of the light beams emitted from the cold cathode tube 12 on a cross section orthogonal to the long axis direction of the cold cathode tube 12 into one. The light is converted into a light flux showing a luminance peak in one or more directions or within a certain angle range. The cylindrical concave mirror 36 will be described below.
As a specific example, the case where a rectangular parallelepiped concave mirror or an elliptical cylindrical concave mirror is used will be described.

First, a specific example using a rectangular parallelepiped concave mirror 37 as the cylindrical concave mirror 36 will be described with reference to FIG.
FIG. 11 is a conceptual diagram for explaining the operation of the prism sheet when a rectangular parallelepiped concave mirror is used as the light beam direction changing means. As shown in the figure, Φ1, γ1,.
Due to the design of the prism angle such as n, the opening surface of the concave mirror 37 is inclined by an angle α with respect to the prism sheet 14a. Further, the central long axis of the cold cathode tube 12 is
At the focal axis f1. For this reason, the luminous flux emitted from the cold cathode tube 12 is reflected by the concave mirror 37 and is in the same direction as the normal 38 of the opening surface of the concave mirror 37, and the prism sheet is directly transmitted from the cold cathode tube 12. The light 40 is converted to light 40 which is directed to a radiation direction within a certain angle range toward 14a. Therefore, the luminous flux (thick arrow) traveling toward the prism sheet 14a includes a luminous flux 39 showing a luminance peak in one direction parallel to the normal 38 and a luminous flux 40 showing a luminance peak within a certain angle range.
Consists of

In the drawing, attention is paid to a representative light beam 39 passing through a representative point k in the w plane and parallel to the normal line 38 and a representative light beam 40 traveling from the cold cathode tube 12 directly to the prism sheet 14a surface. When the light is emitted, the prism angles Φ1, γ1,...,. ,,, Φ
Optimize n, γn and height t. Prism sheet 14b
, The same optimization is performed.

In this way, as many rays as possible in the luminous flux coming from the cold-cathode tube 12 are viewed from the w-plane,
Light can be efficiently controlled by allowing the light to reach the nearest left prism surface 50 or right prism surface 51 and refracted or reflected. Therefore, the luminous flux emitted from the prism sheets 14a and 14b can be converted so as to show a luminance peak in one direction as possible as the optical axis 24. In this manner, as much as possible of the luminous fluxes emitted from the prism sheets 14a and 14b are converted into substantially parallel light rays within the angle θ and effective toward the liquid crystal panel 5 on the incident angle capable of contributing to image formation. Substantially parallel light irradiation can be realized.

Hereinafter, a specific example using the elliptical cylindrical concave mirror 52 as the cylindrical concave mirror 36 will be described with reference to FIG. FIG.
FIG. 4 is a conceptual diagram for explaining an operation with a prism sheet when an elliptic cylindrical concave mirror is used as a light beam direction conversion unit. In the figure, since the cold cathode tube 12 is placed on the first focal axis f2 of the elliptical cylindrical concave mirror 52, the illuminating light traveling toward the prism sheet 14a is reflected by the elliptical cylindrical concave mirror 52 and passes through the second focal axis f3 or its vicinity. 53 and a light beam 54 emitted from or near the first focal axis f2.

For this reason, the elliptic cylindrical concave mirror 52 is
Of the luminous flux emitted from the light source 2, the light in the cross-sectional direction perpendicular to the long axis of the cold-cathode tube 12, the light in the radial direction having the second focal axis f 3 as a fan, and the light in the first focal axis f 2 as a fan. Can be converted into light in the radiation direction.

As described above, in the example using the elliptic cylindrical concave mirror 52, as shown in FIG. 12, a representative line in the w plane formed by a line connecting the peaks of the prisms adjacent to each other facing the cold cathode tube 12 side. Focusing on the representative luminous flux 53 in the radial direction having the second focal axis f3 as a fan and passing through the point k and the representative luminous flux 54 in the radial direction having the first focus axis f2 as a fan, prism angles Φ1, γ
By optimizing 1,... Φn, γn and the height t, substantially parallel light irradiation similar to the case of the concave mirror 37 can be realized.

A fifth embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention will be described below with reference to FIG. FIG. 13 is a side view showing a fifth embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention. In the figure, the luminous flux direction changing means places the Kamaboko Fresnel lens 59 on the exit side of the cylindrical concave mirror 60, and the three axes of the focal axis of the lens 59, the central axis of the cylindrical concave mirror 60, and the central long axis of the cold cathode tube 12 match. Are arranged as follows. The exit surface 61 of the hemispherical Fresnel lens 59 of the light beam direction changing means and the light source side surface 28 of the prism sheet 14a are arranged close to each other to constitute a substantially parallel light irradiation means. Except for the substantially parallel light irradiation means, the configuration is the same as that of the first embodiment.

FIG. 14 is a conceptual diagram for explaining the operation of the prism sheet in the case where a Kamaboko Fresnel lens and a cylindrical concave mirror are used as the light beam direction converting means. In the fifth embodiment, as shown in FIG. 14, after the light beam 62 directly traveling from the cold cathode tube 12 to the prism sheet 14a is also reflected by the cylindrical concave mirror 60, the light 63 passing through or near the central axis of the cylindrical concave mirror 60 is also reduced. Both pass through the focal axis f4 of the Kamaboko Fresnel lens 59 or its vicinity, and are brought closer to the optical axis 24 by the Kamaboko Fresnel lens 59.

However, most of the light is not completely parallel after passing through the lens 59 because of the size of the cold cathode tube 12. Since the cold-cathode tube 12, which is a light emission source, has a symmetrical shape, the emission surface 61 of the Kamaboko Fresnel lens 59 shown in the figure.
The light beams emitted from above are emitted as light beams 64 and 65 having a radial luminance distribution substantially symmetric with respect to the direction of the optical axis 24.

For this reason, in the present embodiment, the light passes through the representative point k on the exit surface 61 of the Kamaboko Fresnel lens 59 installed in close proximity to the w-plane formed by the line connecting the valley bottoms of the adjacent prisms (this representative). Point k is placed in the projection of the w plane). Focusing on the representative rays 64 and 65, the prism angles Φ1, γ1,..., Φn, γ are set for each prism surface within the opening width L of the cylindrical concave mirror 60 in the same manner as in the fourth embodiment.
Optimize n and height t. Similar optimization is performed for the prism sheet 14b. In this manner, substantially parallel light irradiation similar to that of the fourth embodiment can be realized.

In the embodiment shown in FIG. 10, the distance between each part of the cylindrical concave mirror 36 and the cold cathode tube 12 is not uniform, and the distance between each part of the prism sheet 14a and the cold cathode tube 12 is one. In addition, the cold cathode tube 12 itself becomes an obstacle to the reflected light via the cylindrical concave mirror 36, and furthermore,
The level of uniform illumination for equalizing the illuminance at each location on the liquid crystal panel 5 is insufficient due to factors such as uneven illuminance at various locations on the prism sheet 14a due to the reflection characteristics of the cylindrical concave mirror 36 and the like. It may be.

In such a case, a first lens plate for dividing the light beam from the light source into a plurality of sub-beams, and a second lens for forming a plurality of light source images using the plurality of sub-beams divided by the first lens plate Using a plate or the like and using an integrator technique of superimposing and forming a plurality of light source images on a rectangular illumination target enables uniform illumination. This technology is disclosed in
11806.

FIG. 15 shows an embodiment in which the above-described integrator technique is applied to uniform illumination of the prism sheet 14a. FIG. 15 is a schematic diagram showing a sixth embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention. As shown in FIG. 15, the substantially parallel light irradiating means 45 includes a cold cathode tube 12 and a rectangular parallelepiped concave mirror 37 serving as a light beam direction changing means.
, A first lens plate 70, a second lens plate 71, a rectangular lens 72 in the second lens plate 71, and two prisms 7.
3, 74, a polarization separation film 75 formed on the joint surface between the prisms 73, 74, the λ / 2 plate 33, the mirror 34, the third lens 78, and the prism sheet 14a.
And the prism sheet 14b and the unnecessary light removing means 15 are combined.

The first lens plate 70, the second lens plate 71, and the third lens 78 share a role as uniform illumination means.
Further, each of the rectangular lenses 72, the two prisms 73 and 74, the polarization separation film 75, and the λ / 2 plate 3 each having a small size.
3. The arrangement comprising the mirror 34 is arranged as a set of units so as to form a plane perpendicular to the optical axis 24. Among them, one rectangular lens 72 in the second lens plate 71 and two prisms 73 and 74 in the form of a quadrangular prism, a polarization separation film 75 formed on a joint surface between the prisms 73 and 74,
One set of the λ / 2 plate 33 and the mirror 34 constitute a polarization converter. The configuration other than the substantially parallel light irradiation means 45 is the same as that of the first embodiment.

The first lens plate 70 converts the light beam 79 coming through the cold cathode tube 12 and the concave mirror 37 into a plurality of sub-beams 8.
Divide into zero. The second lens plate 71 forms a plurality of light source images using the plurality of sub-beams 80 and also functions as a condenser lens as a role of the second lens plate of the integrator. Since the principal ray 79 from the concave mirror 37 is parallel, the first lens plate 70 and the second lens plate 71
The width and height of the outer shape are made equal.

Hereinafter, the first lens plate 70 and the second lens plate 7
1 will be described with reference to FIG. FIG. 16A is a plan view showing an embodiment of a lens plate, and FIG.
It is an enlarged perspective view of the lens plate of (a). First lens plate 7
0 and the second lens plate 71 can be configured similarly,
Reference numeral 6 denotes both of these lens plates. As shown in FIG. 16, the first lens plate 70 and the second lens plate 71 are formed with a plurality of rectangular lenses 81 and 72 having a shape similar to the illumination target area L ′ of the prism sheet 14 a and viewed from the center 82. Symmetrically, they are arranged in a matrix. First lens plate 70
And the number of rectangular lenses 81 and 72 arranged on the second lens plate 71 need to be equal or proportional. Note that the illumination target area L ′ of the prism sheet 14a is the rectangular parallelepiped concave mirror 3
A straight line parallel to the optical axis 24 set at both ends of the opening width L of No. 6 is an area between two points where the straight line intersects the prism sheet 14a.

The prism sheet 14a and the prism sheet 1
4b plays the same role as in the case of the fourth embodiment, etc., and the prism sheet 14a serves as the representative ray 8 passing through the representative point k in the w plane.
When the prism 3 exits the prism sheet 14a, the prism angle Φ1 is set for each prism 85 corresponding to the opening width L of the concave mirror 36 so that the prism sheet 14a emits toward the liquid crystal panel 5 in the same direction as the optical axis 24 as much as possible. , Γ1,... Φn, γ
n and height t are optimized. Prism sheet 14b
The same applies to. In addition, the prism sheet 14a,
With the prism sheet 14b and the unnecessary light removing unit 15 removed, the angular characteristics of the illuminance (illumination luminance) are measured for points corresponding to all the representative points k of the prism sheet 14a. The light beam 83 can be specified.

The light beam directly from the cold cathode tube 12 and the light beam 79 reflected by the concave mirror 37 are converted into a plurality of sub-beams 8 by a plurality of rectangular lenses 81 in the first lens plate 70.
After being divided into 0, the rectangular lens 81 forms a light source image at the positions of the two prisms 73 and 74.

Next, the plurality of rectangular lenses 72 in the second lens plate 71 adjust the size and position of the light source image formed by the plurality of rectangular lenses 81 in the first lens plate 70 to the polarization separation film 75, and In the vicinity of the polarization separation film 75. Further, the plurality of rectangular lenses 7 in the second lens plate 71
Reference numeral 2 forms a plurality of light source images of a predetermined size on the area L 'of the prism sheet 14a.

The sub-beam 80 converged near the polarization separation film 75 is separated by the polarization separation film 75 into p-polarized light 86 and s-polarized light 87. The p-polarized light 86 passes through the polarization splitting film 75 as it is and goes to the third lens 78. On the other hand, the s-polarized light 87 is reflected by the polarization separation film 75 and travels about 9
Turn 0 degrees and head to mirror 34. The mirror 34 further changes the traveling direction of the s-polarized light 87 by about 90 degrees. Next, the s-polarized light 87 advances at substantially the same angle as the p-polarized light 86, and the λ / 2 plate 3
3, the light is converted into p-polarized light at the time of passage, and travels to the third lens 78. In this way, the light 79 from the cold cathode tube 12 composed of the p-polarized light and the s-polarized light is made uniform to the same p-polarized light and travels to the third lens 78.

The third lens 78 transfers a plurality of light source images formed by the plurality of rectangular lenses 72 in the second lens plate 71 to a position and a size in an area L ′ of the prism sheet 14a which is an illumination target area. Accurately matched, superimposed and illuminated. A superimposed light source image 84 is formed.

As shown in FIG. 16, a plurality of rectangular lenses 81 and 72 having a shape similar to the illumination target area L ′ are arranged in a matrix that is symmetrical when viewed from the lens center. Using the first lens plate 70 and the second lens plate 71, two prisms 73, 74,
The light source image 76 when the second lens plate 71 is viewed by removing the polarization converter 35 composed of the polarization separation film 75, the λ / 2 plate 33, and the mirror 34 formed on the joint surface between the third and the prism 74 is removed. This is shown in FIG. The plurality of light source images 76 are
At the same time as the uneven illuminance is symmetrically distributed with each other,
There is a relationship that complements each other's uneven illuminance.

Using a first lens plate 70 and a second lens plate 71 in which a plurality of rectangular lenses 81 and 72 are arranged symmetrically as viewed from the lens center 82, a light beam 79 from the cold cathode tube 12 is used. Is divided into a plurality of sub-beams 80, and a superimposed light source image 84 is formed by superimposing a large number of light source images in the same area L ′. Is the same as illuminating the same location by using a plurality of light sources that have a relationship that compensates for the illuminance non-uniformity of the prism sheet 14a.
Are uniformly illuminated.

For this reason, the representative light beam 83 passing through the representative point k of each prism 85 of the prism sheet 14a uniformly illuminated.
Are uniformly arranged. Further, as described above, the prism angles Φ1, γ1,... Φn, γn, and the height t are optimized, so that the representative light beam 83 becomes an outgoing light beam 88 substantially parallel to the optical axis 24, and the prism sheet 14b, It goes to the liquid crystal panel 5 via the unnecessary light removing means 15.

As described above, the light flux 79 emitted from the cold-cathode tube 12 composed of p-polarized light and s-polarized light irradiates the illumination target L ′ while being aligned with the same polarized light. Can be improved. In addition, regarding the alignment of the polarization of the light from the cold cathode tube 12, each of the condensing lenses 7 is small.
2, a plurality of sets are arranged in a plane and used as a set including the PBS 32, the λ / 2 plate 33, and the mirror 34, so that the depth of the apparatus is not significantly increased. Further, since the prism sheet 14a that has been uniformly illuminated has the prism angles Φ1, γ1,... Φn, γn and the height t optimized, the light beam 88 emitted from the prism sheet 14a is converted into substantially parallel light beams so that the liquid crystal panel 5 I'm going to. The same applies to the light flux emitted from the prism sheet 14b. As described above, in the sixth embodiment, the light utilization rate is greatly improved, and the uniform illumination and the substantially parallel light irradiation for equalizing the illuminance of each part of the entire surface of the liquid crystal panel 5 are realized.

In this embodiment, if the rectangular lenses 81 and 72 provided on the first lens plate 70 and the second lens plate 71 are made smaller, the distance between the first lens plate 70 and the second lens plate 71 can be made smaller. The lens plate 70 and the second lens plate 71 can be integrated, and a uniform illumination function can be shared by one lens plate. In most cases, the first lens plate 70 and the second
If the number of rectangular lenses 81 and 72 provided on the lens plate 71 is four or more, sufficient uniform illumination can be realized.

When the illuminance non-uniformity in the long axis direction (perpendicular to the paper surface) of the cold cathode tube 12 can be ignored, the first lens plate 70 and the second lens plate 71 in which a plurality of rectangular lenses 81 and 72 are arranged in parallel are arranged. Even when used, uniform illumination can be realized.

On the other hand, when an elliptic cylindrical concave mirror 52 is used instead of the rectangular concave mirror 36, the size and position of the light source image formed by the second lens plate 71 can be adjusted to the object to be illuminated.
The lens 78 need not be used. When the polarization converter is not used, the third lens 78 and the second lens plate 71 can be integrated. In this case, the uniform illumination function can be shared by the two lens plates. The method of using various concave mirrors and the method of integrating lenses are disclosed in detail in JP-A-3-111806. The illumination target area L ′ is determined according to the concave mirror opening width L. Therefore, when the concave mirror opening width L is reduced, the illumination target area L ′ is also reduced, so that the distance from the second lens plate 71 to the prism sheet 14a to be illuminated can be shortened. Therefore, if the concave mirror opening width L is reduced by using the cold cathode tube 12 having a small diameter, for example, 3Φ or less, it is very advantageous to reduce the depth of the apparatus.

Next, a seventh embodiment of the substantially parallel light irradiation means will be described with reference to FIG. In this embodiment, a metal thin film such as aluminum (AL) is formed into a mosaic shape, a mesh shape,
A transparent plate formed on the surface in an appropriate pattern such as a stripe pattern or a dot pattern is disposed between the cold cathode tube 12 and the liquid crystal panel 5 or between the cylindrical concave mirror 36 and the prism sheet 14a as a uniform illuminating means. Thus, a substantially parallel light irradiation unit is configured.

By forming the metal thin film in the pattern described above,
A fine transmission surface and a non-transmission surface can be distributed on each part of the surface of the transparent plate. Therefore, by appropriately changing the transmittance per unit area of each part of the transparent plate, it is possible to eliminate the influence of uneven illuminance at the surface mirror opening L. The non-transmissive surface of the metal thin film returns a portion of the light coming from the light source to the cylindrical concave mirror 36 side, reflects the light again by the cylindrical concave mirror 36, transmits the transparent surface of each part of the transparent plate surface, and transmits the liquid crystal panel 5 It can contribute to lighting. Thus, in the seventh embodiment, in addition to realizing substantially parallel light irradiation, the liquid crystal panel 5
Uniform illumination for equalizing the illuminance of each part of the entire surface of the device can be realized.

FIG. 1 shows an eighth embodiment in which the depth of a projection type liquid crystal display device using the sixth embodiment is further reduced and the lamp power efficiency of the uniform illumination means of the seventh embodiment is improved.
7 will be described. FIG. 17 is a side view showing an eighth embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention. In this embodiment, as shown in FIG. 17, a rectangular parallelepiped concave mirror 37 is used as a light beam direction changing unit, and the cold cathode tube 12, the polarization separation film 31, and the unnecessary light removing unit 15 are used. Three prism sheets 89 between the reflection type polarization separation films 31;
The substantially parallel light irradiation means 46 was constituted by arranging 14a and 14b. The configuration other than the substantially parallel light irradiation means 46 is the same as that of the first embodiment.

The role as the uniform illumination means is shared by the prism sheet 89. The prism sheets 14a and 14b share the same role as the prism sheets 14a and 14b shown in FIG. Since the structure other than the prism sheet 89 is the same as that of the fourth embodiment, the description will be omitted unless otherwise required.

Hereinafter, referring to FIG.
The operation of the prism sheet 89 as a uniform illumination means and the prism sheet 14a for substantially parallel light irradiation will be described.
FIG. 18 is a conceptual diagram for explaining the functions of the rectangular cylinder concave mirror, the prism sheet as the uniform illumination means, and the prism sheet for substantially parallel light irradiation. In the figure, the w1 surface is a surface composed of lines connecting the peaks of the prisms of the prism sheet 89, k
1, kn are representative points for each prism of the prism sheet 89. Representative rays 92a and 92b passing through the representative point k1
Is refracted or reflected in the prism 91, and the outgoing light beam 90
a, 90b, and head toward the prism sheet 14a. Then, the light is refracted or reflected in the prism 93 and exits from the exit surfaces 94 and 95 of the prism sheet 14a.
a ′ and 90b ′, and the liquid crystal panel 5 is directed to the liquid crystal panel 5 via the prism sheet 14b. A representative ray 96a passing through the representative point kn,
The same applies to 96b.

Next, a procedure for realizing uniform illumination in the eighth embodiment will be described with reference to FIG. 19 which is a simplified model of FIG. FIG. 19 is a conceptual diagram of uniform illumination obtained by simply modeling FIG. 19, the same reference numerals as those in FIG. 18 indicate the same items. In the figure, both ends of the prism sheet 89 and the prism sheet 14a represent positions corresponding to both ends of the opening width L of the concave mirror 37. The position is a point where a straight line parallel to the optical axis 24 set at both ends of the opening width L of the concave mirror 37 intersects the prism sheet 89 or 14a, and the width is L '.

The arrow 90 in FIG. 18 indicates that the representative rays 90a and 90b in FIG.
b is represented by one straight line. a1, a2,... a
n indicates the illuminance non-uniform distribution of the entire w1 surface of the prism sheet 89 in FIG. 18 for each of the illuminance levels L1, L2,.
This is an index divided into small areas. b1, b
2,..., Bn are prism sheets 1 divided for each range irradiated with representative light beams passing through a1, a2,.
4A shows a small area. The black circle in FIG.
The representative points k1,... Kn in the plane are shown.

FIG. 20 is a conceptual diagram showing the relationship between the illuminance of each small area of the prism sheet as the uniform illumination means and the prism sheet for substantially parallel light irradiation. 20 represent a corresponding set in a1, a2,..., An and b1, b2,. b'n indicates a case where bn is moved away from an. A thick arrow indicates one representative ray passing through both an and bn. A thin arrow indicates a light beam of diffused light represented by the representative light beam, and a dotted arrow indicates diffused light having a large angle range of the light beam.

Since the light emitted from the cold cathode tube 12 to the prism sheet 89 is diffused light, as shown in FIG.
The closer the is to an, the more efficiently the luminous flux passing through an
bn can also penetrate. In FIG. 20, the following (Equation 2) holds. bn area × bn illuminance = c × an area × an illuminance. . . . Here, c is the light loss rate determined by the characteristics of the light source and the distance between an and bn. When both are sufficiently close to each other or when the angle range of the luminous flux coming from the light source (the cold cathode tube 12) is small, It can be approximately regarded as 1.

When the illuminance can be regarded as uniform in the long axis direction of the cold cathode tube 12, the following expression (3) holds. bn width × bn illuminance = c × an width × an illuminance. . . . . (Equation 3) FIG. 18 is different from FIGS. 19 and 20 in that rays 90 a, 90 b, 96 a, 96 b, etc. are refracted or reflected in the prisms 91, 93, etc. When the prism sheet 14a is sufficiently close, FIG.
A small area obtained by dividing the illuminance non-uniform distribution on the w1 surface of the prism sheet 89 into illuminance levels L1, L2,.
(Equation 3) also holds between the small area of the prism sheet 14a irradiated with the representative light beam passing through the small area.

Further, even when the prism sheet 89 and the prism sheet 14a are not sufficiently close to each other, the illuminance non-uniform distribution on the w1 surface of the prism sheet 89 can be determined by the illuminance levels L1 and L1.
Equation 3 is useful for examining the illuminance relationship between the small area divided for each Ln and the small area of the prism sheet 14a irradiated with the representative light beam passing through the small area.

In order to make the illuminance of the prism sheet 14a constant, it is necessary to make (an width × an illuminance) / (bn width) constant from (Equation 3). Therefore, in FIG. 19, if a1 is in the low illuminance region, as shown in FIG. 19, the representative light beams 90a and 90b emitted from within the a1 region toward the prism sheet 14a so that the width of b1 is narrower than a1. Etc. need to be controlled. Also, if a2 is a medium illuminance range, the width of b2 is the same as the width of a2.
It is necessary to control the representative light beam emitted from the inside of the area a2 toward the prism sheet 14a so that the width becomes as shown in FIG. Also, if an is a high illuminance region, it is necessary to control representative light beams 96a, 96b and the like emitted from the an region toward the prism sheet 43b so that the width of bn becomes wider than an. This is a guideline for stabilizing the illuminance of the prism sheet 14a by illumination with light passing through the prism sheet 89 having an uneven illuminance on the w1 surface.

In the eighth embodiment, w of prism sheet 89
Illuminance non-uniform distribution over the entire area of one surface is calculated using multi-level illumination levels L
Each of L1,..., Ln is divided into small areas a1, a2,... An, and each of a1, a2,. For each small area, the prism angles α1, β1,..., Αn, βn and the height t
1, prism sheet 89 and prism sheet 14
The distance T between a was optimized.

The prism angle α1 of the prism sheet 89,
When optimizing β1,..., αn, βn, etc., FIG.
The prism angle is optimized by combining various prism shapes as shown in (a) and (b).

FIGS. 21A and 21B are side views showing an embodiment of light beam control by the prism shape of the prism sheet. Each prism of the prism sheet 89 is shown in FIG.
(A), the representative rays 90a, 90b,..., 96 traveling from the prism sheet 89 to the prism sheet 14a by changing the prism shape as shown in FIG.
The emission angles such as a and 96b can be appropriately controlled. In this way, uniform illuminance on the w surface of the prism sheet 14a can be realized.

Similarly, the prism shape of the prism sheet 14a can be optimized. By optimizing, the prism sheet 1 uniformly illuminated as described above
From each of the prisms 4a, the emitted light beams having uniform illuminance, such as 90a 'and 90b', are made substantially parallel to the optical axis 24 and directed toward the liquid crystal panel 5 via the prism sheet 14b and the unnecessary light removing means 15. Can be changed. Prism sheet 14
The same applies to b. In this way, in the eighth embodiment, in addition to the realization of the substantially parallel light irradiation, the uniform illumination for equalizing the illuminance of the entire surface of the liquid crystal panel 5 can be realized. A description will be given of another embodiment in which only the control method of the representative light beam emitted from the prism sheet 89 toward the prism sheet 14a in the eighth embodiment is changed. A procedure for realizing uniform illumination in the ninth embodiment will be described with reference to FIG. 22, which is a simplified model of FIG.

FIG. 22 is a conceptual diagram of another uniform illumination obtained by simply modeling FIG. In the figure, the same reference numerals as those in FIG. 18 indicate the same items. Further, a1, a2,..., An are small areas having the same meaning as in the eighth embodiment shown in FIG. However, the black circles represent the a of the prism sheet 89 described above.
The representative points at both ends of each small area of 1, a2,.
White circles indicate representative points other than both ends of each small area of a1, a2,.

In the ninth embodiment, as shown in FIG.
Representative points (black circles) at both ends of each small area of 1, a2,.
Is controlled to pass through both ends of L 'of the prism sheet 14a. A representative ray passing through a representative point (open circle) other than both ends of each small area passes through a point corresponding to a point obtained by equally dividing L ′ of the prism sheet 14a by the number of representative points −1 in each small area. To control. For example, as shown in FIG. 22, when the number of representative points of the small area a1 is four, the representative ray 97 passing through the second representative point from the left end of a1 divides L ′ of the prism sheet 14a into three equal parts. Irradiate so as to pass through the second point from the left end of the point (small square).

From the prism sheet 89 to the prism sheet 1
When the representative rays such as 90, 96, 97, 98, and 99 emitted toward 4a are controlled in this way, as shown in FIG.
From each of a1, a2,... an, the representative rays 90, 9
Irradiating 7, 98, 99, etc., evenly over the entire area of L 'of the prism sheet 14a, a1, a2,.
Can be repeated for each location.

From the prism sheet 89 to the prism sheet 1
4a, the representative rays 90, 97, 98, 99,
96, etc., as described above, the prism sheet 8
9 for each of the small areas a1, a2,..., An, and prism angles and heights α1, β1,.
Distance T between prism sheet 89 and prism sheet 14a
Optimized. Other points are the same as in the eighth embodiment.

For this reason, when viewed in each small area, the representative rays 90, 97, 98, and 99 having small illuminance differences from each of the locations a1, a2,.
Irradiation evenly over the entire area within L 'of the prism sheet 14a can be repeated for each of the locations a1, a2,... An, and the illuminance of the prism sheet 14a can be made uniform. In this manner, in the ninth embodiment, in addition to realizing substantially parallel light irradiation, uniform illumination for equalizing the illuminance of the entire surface of the liquid crystal panel 5 can be realized.

The prism sheet 89 in the eighth embodiment
Another embodiment will be described in which only the method of controlling the representative light beam emitted toward the prism sheet 14a is changed.
A procedure for realizing uniform illumination in the tenth embodiment will be described with reference to FIG. 23 which is a simplified model of FIG.

FIG. 23 is a conceptual diagram of yet another uniform illumination obtained by simply modeling FIG. In FIG.
The same reference numbers indicate the same items. In the tenth embodiment, the w1 surface of the prism sheet 89 is simply divided into a plurality of small regions having the same width. A1, A2,... An of FIG.
Indicate small areas obtained by simply dividing the w1 surface of the prism sheet 89 into a plurality of areas having the same width. All other features are the same as in the ninth embodiment.

In the tenth embodiment shown in FIG. 23, as in the ninth embodiment, the representative light passing through the representative points (black circles) at both ends of each of the small areas A1, A2,.
A representative ray passing through both ends of L ′ of 4a and passing through representative points (open circles) other than both ends of each small area is a point obtained by equally dividing L ′ by the number of representative points in each small area minus one. Corresponding point (9th
Prism angles and heights α1 and β for each of the small areas so as to pass through the corresponding points having the same meaning as in the illustration used in the description of the embodiment.
1,... Αn, βn and t1, and prism sheet 8
The distance T between No. 9 and the prism sheet 14a was optimized. In this manner, in the tenth embodiment, in addition to the realization of the substantially parallel light irradiation, the uniform illumination for equalizing the illuminance of each part of the entire surface of the liquid crystal panel 5 can be realized.

Although the erect image forming means employed in the first to tenth embodiments comprises a plurality of convex lens arrays 61 and 62, the present invention is not limited to this. As Optical Engineering Handbook p556-p561 (1
The flat index microlens array, the self-occ lens array, the rod type microlens array, the refractive index distribution optical fiber, which is a refractive index distribution type lens array conventionally known in February 20, 878, first edition, Asakura Shoten), etc. What is constituted by a bundle etc. may be used.

Further, in the first to tenth embodiments, the prism sheet in which the minute uneven surface for converting the luminous flux emitted from the light source or the luminous flux direction converting means into the luminous flux showing the peak of luminance in the same direction is arranged. I used 14a, 14b,
The prism sheet 14 is designed so that the luminous flux emitted from the light source or the luminous flux direction changing means is set as much as possible within the angle θ.
a, 14b, it is not necessary to limit the shape of the fine uneven surface of the prism sheet to one having a function of converting into a light beam showing a peak of luminance in the same direction, and the shape of the light emitted from the light source or the light beam direction changing means is not necessary. It goes without saying that it is only necessary to have an action of making the light flux as large as possible and within the angle θ.

Therefore, in the embodiment of the present invention, a triangular shape is used as the shape of the fine uneven surface forming the prism function formed on the prism sheets 14a and 14b. Polygons, triangular pyramids, polygonal pyramids, cones, truncated cones, semi-cylindrical shapes, hair lines, pears and other fine irregularities may be used.

Further, the concave mirror in the fourth to tenth embodiments may be a concave mirror of a rectangular cylinder or a concave mirror of a cylinder.
Alternatively, an elliptic cylindrical concave mirror, a hyperbolic cylindrical concave mirror, a non-spherical cylindrical concave mirror, or the like can be used. Further, the concave mirror used in the present invention is not limited to the concave surface having a concave curved surface.
For example, the concave surface may be a concave surface formed by alternately forming a belt-shaped reflection plane and a band-shaped non-reflection plane, or a concave surface formed by connecting a band-shaped reflection plane in a polygonal line.

In the eighth to tenth embodiments, the prism sheet is used as the uniform illumination means.
Although only one sheet was used and uniform illumination was not performed in the long axis direction of the cold cathode tube 12, the number of prism sheets was added, and uniform illumination was performed in the long axis direction of the cold cathode tube 12. It is natural that it may be changed.

FIG. 24 is a side view showing an embodiment of light beam control using three prism sheets. Performed for uniform illumination or substantially parallel light irradiation, when the control amount such as the light emission angle or arrival position is large, etc., if necessary, as shown in FIG.
Of course, a plurality of prism sheets may be used. Conversely, depending on the required degree of uniform illumination and the degree of substantially parallel light irradiation, it is natural that one prism sheet may serve as both the uniform lighting means and the substantially parallel light irradiation means.

The fourth, seventh, eighth to tenth aspects of the present invention
In the embodiment, the polarization separation film 31 is used. However, in the present invention, the polarization separation film 31 is replaced with a plane-arranged polarization converter shown in FIG. May be. By doing so, the light utilization factor can be further improved. In the embodiment of the present invention, in order to give priority to the reduction of the depth, the projection type liquid crystal display device 1 uses a light source or a light beam direction changing means in which a large number of cold cathode tubes 12 and cylindrical concave mirrors 36 are arranged. The invention relates to a projection type liquid crystal display device 1
Needless to say, a single light source or a light beam direction changing means may be used.

In the embodiments of the present invention, the cold cathode tube 12 is used as the light source. However, it goes without saying that the present invention may employ a linear light source such as a hot cathode tube or a double tube as the light source. . Furthermore, in the present invention, the shape of the concave mirror disposed behind the light source and the lens disposed on the emission side of the light source and the Fresnel lens 59 are made circular, and at the same time, the micro prisms formed on the prism sheet are concentrically arranged or radially arranged. Needless to say, a point light source such as a miniature lamp may be used as the light source. In this case, the light source becomes point-symmetric, and many of the optical components can be made point-symmetric, so that light loss can be easily reduced.
It can be easily improved.

In the embodiment, an example in which the invention is applied to a projection type liquid crystal display device using erect image forming means is shown. However, the fourth to tenth embodiments of the present invention use the erect image forming means. Not in,
The present invention is also applicable to a direct-view type liquid crystal image display device and a front type projection type liquid crystal display device.

In the present invention, it is possible to obtain a bright projection image by greatly improving the lamp power efficiency, and to obtain a projection type liquid crystal display device in which the depth of the display device is reduced. For this reason, a large-size image projection device product (for PC display or digital TV), which is considered to be very difficult to commercialize with a single liquid crystal panel, and has the feature of having a very short depth, is relatively inexpensive. realizable.

[0122]

As described above, according to the present invention, the lamp power efficiency can be greatly improved and a bright projected image can be obtained. Further, a projection type liquid crystal display device in which the depth of the display device is reduced can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a substantially parallel light irradiation means used in a projection type liquid crystal display device according to the present invention.

FIG. 2 is a schematic diagram showing one embodiment of a large-sized projection device in which some of the projection-type liquid crystal display devices according to the present invention are arranged.

FIG. 3 is a schematic view showing one embodiment of a projection type liquid crystal display device according to the present invention.

FIG. 4 is a conceptual diagram for explaining the operation of an edge light light guide and a prism sheet of the substantially parallel light irradiation means of FIG. 1;

FIG. 5 is a plan view showing an embodiment of unnecessary light removing means.

FIG. 6 is a sectional view of an unnecessary light removing unit.

FIG. 7 is a side view showing a second embodiment of the substantially parallel light emitting means used in the projection type liquid crystal display device according to the present invention.

FIG. 8 is a side view showing a third embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention.

9A and 9B are a side view and a plan view showing an embodiment of the arrangement of the edge light guide and the cold cathode tubes.

FIG. 10 is a side view showing a fourth embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention, and a perspective view showing one embodiment of the light beam direction changing means.

FIG. 11 is a conceptual diagram for explaining an operation with a prism sheet when a rectangular parallelepiped concave mirror is used as a light beam direction conversion unit.

FIG. 12 is a conceptual diagram for explaining an operation with a prism sheet when an elliptic cylindrical concave mirror is used as a light beam direction conversion unit.

FIG. 13 is a side view showing a fifth embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention.

FIG. 14 is a conceptual diagram for explaining the operation of a prism sheet when a Kamaboko Fresnel lens and a cylindrical concave mirror are used as a light beam direction conversion unit.

FIG. 15 is a schematic view showing a sixth embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention.

FIG. 16 is a plan view showing an embodiment of a lens plate used for uniform illumination means and an enlarged perspective view thereof.

FIG. 17 is a side view showing an eighth embodiment of the substantially parallel light irradiation means used in the projection type liquid crystal display device according to the present invention.

FIG. 18 is a conceptual diagram for explaining the functions of a rectangular parallelepiped concave mirror, a prism sheet as uniform illumination means, and a prism sheet for substantially parallel light irradiation.

FIG. 19 is a conceptual diagram of uniform illumination obtained by simply modeling FIG. 18;

FIG. 20 is a conceptual diagram showing the relationship between the illuminance of each small area of a prism sheet as a uniform illumination means and a prism sheet for substantially parallel light irradiation.

FIG. 21 is a side view showing an embodiment of light beam control by the prism shape of the prism sheet.

FIG. 22 is a conceptual diagram of another uniform illumination obtained by simply modeling FIG. 18;

FIG. 23 is a conceptual diagram of yet another uniform illumination obtained by simply modeling FIG. 18;

FIG. 24 is a side view showing an embodiment of light beam control using three prism sheets.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Projection type liquid crystal display device, 2 ... Large projection device, 3 ... Screen, 4 ... Gap between liquid crystal panels 5, 5 ... Liquid crystal panel,
6a: first lens array, 6b: second lens array, 7
... Fresnel concave lens, 8 ... Image of liquid crystal panel 5, 9 ... Inverted image, 10 ... Erect image, 11 ... Enlarged image, 12, 12a, 1
2b: cold cathode tube, 13, 13 ': edge light guide,
14a, 14b: prism sheet, 15: unnecessary light removing means, 16: reflection sheet, 19: slightly convex surface, 21a, 21
b, 29, 30, 92a, 92b, 90, 90a ', 9
0b ′, 64, 65, 66, 67, 88...
2, 23, 83, 96a, 96b, 96, 97, 98,
99: representative light beam, 24: optical axis, 31: reflection type polarization separation film, 32: PBS, 33: λ / 2 plate, 34:
Mirror, 35: polarization converter, 36: cylindrical concave mirror, 37 ...
Parabolic cylinder concave mirror, 38 normal, 41, 42, 43, 44,
45, 46... Substantially parallel light irradiation means, 50, 51, 55, 5
6: prism surface, 52: elliptical cylindrical concave mirror, 53, 54,
57, 58, 62, 63, 39, 40: light flux, 59: Kamaboko Fresnel lens, 60: cylindrical concave mirror, 61: emission surface,
70: first lens plate, 71: second lens plate, 72: second
A rectangular lens in the lens plate 71, 73, 74: two prisms in the form of a quadrangular prism, 75: a polarization separation film, 78: a third lens, 79: a principal ray, 80: a sub beam, 81: a rectangle in the first lens plate 70 85, prism, 84, superimposed light source image, 86, p polarized light, 87, s polarized light, 89, prism sheet as uniform illumination means, 91, 93, prism.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 EA15 EA18 HA13 HA22 HA25 HA30 MA06 2H091 FA14X FA14Y FA23Y FA26X FA26Y FB02 FC17 FC19 FD06 FD16 FD22 GA17 LA03 LA04 LA18 MA07

Claims (47)

[Claims] 1. A projection type liquid crystal display device wherein a prism sheet having a large number of micro prisms is arranged between a light source and a liquid crystal panel, and an image is projected on a screen by erect image forming means. 2. The projection type liquid crystal display device according to claim 1, wherein said micro prism has a shape such as a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a truncated cone, a hairline, or a satin finish. A projection type liquid crystal display device characterized by being constituted. 3. A light source, an edge light guide for converting a light beam emitted from the light source into a light beam having a luminance peak in one direction, a plurality of directions, or within an angle range, a liquid crystal panel, and the light source A projection type liquid crystal display device comprising: a prism sheet arranged between the liquid crystal panel and a plurality of micro prisms; and an erect image forming means for erectly forming an image of the liquid crystal panel on a screen. . 4. A light source, a light beam direction changing means for changing the direction of light from the light source, a liquid crystal panel, a prism sheet disposed between the light source and the liquid crystal panel and having a large number of micro prisms arranged therein. A projection type liquid crystal display device, comprising: erect image forming means for erectly forming an image of a liquid crystal panel on a screen. 5. The projection type liquid crystal display device according to claim 4, wherein said light beam direction changing means includes a concave mirror, a cylindrical concave mirror, a lens, a Kamaboko Fresnel lens, a combination of a concave mirror and a lens, and a combination of a cylindrical concave mirror and a lens. And a combination of a concave mirror and a Kamaboko Fresnel lens, or a combination of a cylindrical concave mirror and a Kamaboko Fresnel lens. 6. The projection type liquid crystal display device according to claim 1, wherein said erecting image forming means includes a plurality of convex lens arrays, a flat microlens array which is a gradient index lens array, and a self-occurring lens. A projection-type liquid crystal display device comprising any one of an array, a rod-type microlens array, and an optical fiber bundle with a distribution of bending ratio. 7. A projection type liquid crystal display device according to claim 1, further comprising an unnecessary light removing means for removing a part of a light beam emitted from said prism sheet. Display device. 8. A projection type liquid crystal display device according to claim 7, wherein said unnecessary light removing means is constituted by arranging any one of a polygonal hole and a round hole in a close-packed arrangement. Liquid crystal display. 9. The projection type liquid crystal display device according to claim 3, wherein said edge light guide has a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid on one or both of an exit surface and a rear surface.
Edge light guide with cone, truncated cone, semi-cylindrical shape, hairline, or matte surface, edge light guide with flat exit surface, edge light guide with light scattering material dispersed inside Body, an edge light guide having a light scattering body printed on the back surface, an edge light guide having a hollow inside, or an edge light guide formed by laminating a plurality of transparent plates. Projection type liquid crystal display device. 10. The projection type liquid crystal display device according to claim 3, wherein said light source is arranged on a side end surface of said edge light guide. 11. A projection type liquid crystal display device according to claim 1, wherein said light source is one of a hot cathode tube, a cold cathode tube, and a fluorescent tube, and one or more layers are arranged. Projection type liquid crystal display device. 12. A projection type liquid crystal display device according to claim 3, wherein a polarization converter is provided, and said polarization converter is arranged between said light source and said edge light guide. Projection type liquid crystal display device. 13. A projection type liquid crystal display device according to claim 4, wherein said light beam direction changing means is a combination of a concave mirror and a lens, and said lens uses any one of a convex lens, a convex lens and a convex Fresnel lens. A projection type liquid crystal display device characterized by the above-mentioned. 14. A projection type liquid crystal display device according to claim 4, wherein said light source is constituted by a fluorescent tube which is any one of a hot cathode tube, a cold cathode tube double tube and the like, and said light beam direction changing. The projection type liquid crystal display device, wherein the means is a cylindrical concave mirror such as a cylindrical concave mirror, a rectangular concave mirror, an elliptical cylindrical concave mirror, a hyperbolic cylindrical concave mirror, and a non-spherical cylindrical concave mirror. 15. A projection type liquid crystal display device according to claim 4, wherein said light source is a point light source such as a miniature lamp, and said light beam direction changing means is a spherical concave mirror, a parabolic concave mirror, an elliptical concave mirror,
A projection type liquid crystal display device comprising a concave mirror such as a hyperbolic concave mirror or an aspherical concave mirror. 16. A projection type liquid crystal display device according to claim 1, wherein said liquid crystal panel is constituted by a transmission type liquid crystal panel, and an enlargement projection means for enlarging a light image from said transmission type liquid crystal panel is provided. A projection type liquid crystal display device characterized by the above-mentioned. 17. A projection type liquid crystal display device according to claim 16, wherein a driver IC or the like is arranged in a frame shape around a pixel portion of said transmission type liquid crystal panel. 18. A projection type liquid crystal display device according to claim 1, further comprising: an enlargement projection unit for enlarging a light image of said liquid crystal panel, wherein said enlargement projection unit is constituted by a Fresnel concave lens. Projection type liquid crystal display device. 19. A projection type liquid crystal display device according to claim 1, wherein said liquid crystal panel is constituted by a transmission type liquid crystal panel, and a reflection type polarization separating film is provided between said light source and said transmission type liquid crystal panel. A projection type liquid crystal display device comprising: 20. The projection type liquid crystal display device according to claim 1, further comprising: a uniform illuminating means comprising a lens plate in which a plurality of rectangular lenses are arranged in a matrix or in parallel; A projection type liquid crystal display device, wherein the projection type liquid crystal display device is disposed between the prism sheet and the prism sheet. 21. A projection type liquid crystal display device according to claim 1, wherein said light source is a linear light source of a cold cathode tube having a diameter of 3 mm or less. 22. A projection type liquid crystal display device according to claim 1, further comprising a polarization converter, wherein said liquid crystal panel is constituted by a transmission type liquid crystal panel, and said polarization converter is constituted by said light source and said transmission type liquid crystal panel. A projection type liquid crystal display device which is arranged between liquid crystal panels. 23. The projection type liquid crystal display device according to claim 1, wherein the metal thin film has a mosaic shape.
By forming a mesh-like pattern, the reflection surface and the transmission surface are provided with a uniform illuminating means made of a transparent plate formed in a mosaic-like or mesh-like distribution, and the liquid crystal panel is formed by a transmission-type liquid crystal panel. A projection type liquid crystal display device, wherein the uniform illumination means is arranged between the light source and the transmission type liquid crystal panel. 24. The projection-type liquid crystal display device according to claim 1, wherein the shape is a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a truncated cone, a hairline, a satin finish or the like. A uniform illuminating means comprising a prism sheet having a plurality of micro prisms, wherein the liquid crystal panel is constituted by a transmissive liquid crystal panel, and arranged between the light source and the transmissive liquid crystal panel. Display device. 25. The projection type liquid crystal display device according to claim 1, wherein said prism sheet is a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a truncated cone, a hairline, The liquid crystal panel is constituted by a plurality of micro prisms having a satin finish or the like and serves as a uniform illumination means and a substantially parallel light irradiation means, and the liquid crystal panel is constituted by a transmission type liquid crystal panel,
The projection type liquid crystal display device, wherein the prism sheet is disposed between the light source and the transmission type liquid crystal panel. 26. A prism sheet in which a large number of micro prisms are arranged is disposed between a light source and a liquid crystal panel, and a plurality of projection type liquid crystal display devices for projecting an image on a screen by erect image forming means are arranged vertically and horizontally on the same screen. A projection display device that projects and displays seamless images on the same screen. 27. A light source, an edge light guide for converting a light beam emitted from the light source into a light beam having a peak of luminance, a liquid crystal panel, and a liquid crystal panel, wherein the liquid crystal panel is disposed between the light source and the liquid crystal panel.
A plurality of projection type liquid crystal display devices having a prism sheet in which a number of micro prisms are arranged and erect image forming means for erectly forming an image of a liquid crystal panel on a screen are arranged vertically and horizontally and projected on the same screen, and are seamlessly connected. A projection display device, wherein a continuous image is displayed on the same screen. 28. A light source, light beam direction changing means for changing the direction of light from the light source, a liquid crystal panel, a prism sheet arranged between the light source and the liquid crystal panel and having a large number of micro prisms arranged therein, A plurality of projection type liquid crystal display devices having erect image forming means for erect image formation of an image of a liquid crystal panel on a screen are arranged vertically and horizontally and projected on the same screen, and a continuous image is displayed on the same screen. A projection display device characterized by the above-mentioned. 29. The projection type liquid crystal display device according to claim 1, wherein said liquid crystal panel is constituted by a transmission type liquid crystal panel, and the number of pixels of said transmission type liquid crystal panel is (VGA, SVGA, XGA, SXGA, UXGA
27. The projection type liquid crystal display device, wherein the number of pixels according to a pixel number standard such as ÷ / (the total number of the projection type liquid crystal display devices of the above-described claim 26) + the number of pixels required for the overlapping portion. 30. The projection type liquid crystal display device according to claim 1, wherein the prism sheet is a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone,
It is a substantially parallel light irradiating means having a plurality of micro prisms in a shape of a semicircle, a hair line, a satin finish, etc., wherein the liquid crystal panel is constituted by a transmissive liquid crystal panel, and the substantially parallel light irradiating means is a light source and the transmissive liquid crystal. A projection type liquid crystal display device which is arranged between panels. 31. A light source, a transmissive liquid crystal panel, a triangle,
A prism sheet having a plurality of micro prisms having a trapezoidal, polygonal, triangular pyramid, polygonal pyramid, cone, truncated cone, semicylindrical, hairline, satin finish, etc., wherein the prism sheet is used as uniform illumination means or substantially parallel. As light irradiation means,
Alternatively, a direct-view type liquid crystal display device is provided between the light source and the transmissive liquid crystal panel, also serving as uniform illumination means and substantially parallel light irradiation means. 32. A light source, a transmissive liquid crystal panel, a triangle,
A prism sheet having a plurality of micro prisms having a trapezoidal, polygonal, triangular pyramid, polygonal pyramid, cone, truncated cone, semicylindrical, hairline, satin finish, etc., wherein the prism sheet is used as uniform illumination means or substantially parallel. As light irradiation means,
Alternatively, a front projection type liquid crystal display device is provided between the light source and the transmissive liquid crystal panel, serving as a uniform illumination unit and a substantially parallel light irradiation unit. 33. A light source and a light beam emitted from the light source in one direction,
A substantially parallel light irradiating means, comprising: an edge light guide for converting a light beam having a luminance peak in any one of a plurality of directions and a certain angle range; and a prism sheet on which a large number of micro prisms are arranged. 34. A substantially parallel light irradiating means, comprising: a light source; a light beam direction changing means for changing a direction of light from the light source; and a prism sheet on which a large number of micro prisms are arranged. 35. The substantially parallel light irradiating means according to claim 33, wherein an unnecessary light removing means is provided to remove a part of a light beam emitted from said prism sheet. . 36. The substantially parallel light irradiating means according to claim 33 or 34, wherein said minute prism is a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a truncated cone, a hairline, a satin finish or the like. A substantially parallel light irradiating means having a shape. 37. A projection type liquid crystal display device according to claim 35, wherein said unnecessary light removing means is constituted by closely arranging holes such as polygonal holes and round holes. Light irradiation means. 38. The substantially parallel light irradiating means according to claim 34, wherein said light beam direction changing means comprises a concave mirror, a cylindrical concave mirror,
Lens, Kamaboko Fresnel lens, Combination of concave mirror and lens, Combination of cylindrical concave mirror and lens, Combination of concave mirror and Kamaboko Fresnel lens, Combination of cylindrical concave mirror and Kamaboko Fresnel lens Substantially parallel light irradiating means. 39. The substantially parallel light irradiating means according to claim 33, wherein a polarization converter is provided, and said polarization converter is disposed between said light source and said edge light guide. Irradiation means. 40. The substantially parallel light irradiation means according to claim 34, wherein said light beam direction converting means is a combination of a concave mirror and a lens, and said lens uses any one of a convex lens, a convex lens and a convex Fresnel lens. A substantially parallel light irradiation means. 41. The substantially parallel light irradiating means according to claim 33, wherein said edge light guide has a triangle, a trapezoid, a polygon, a triangular pyramid, a polygonal pyramid, a cone, Edge light guide with a slightly convex surface such as frustoconical, semicylindrical, hairline, satin finish, edge light guide with flat emission surface, edge light guide with light scattering body dispersed inside, light scattering An edge light light guide having a body printed on the back surface, an edge light light guide having a hollow inside, or an edge light light guide formed by laminating a plurality of transparent plates; Light irradiation means. 42. The substantially parallel light irradiating means according to claim 34, wherein said light source comprises a fluorescent tube which is one of a hot cathode tube, a cold cathode tube double tube and the like, and said luminous flux direction changing unit. Is a cylindrical concave mirror, a rectangular concave mirror, an elliptical cylindrical concave mirror,
A substantially parallel light irradiation means, which is a cylindrical concave mirror such as a hyperbolic cylindrical concave mirror or a non-spherical cylindrical concave mirror. 43. The substantially parallel light irradiating means according to claim 33, wherein a reflection type polarization separation film is provided. 44. The substantially parallel light irradiating means according to claim 34, wherein a uniform illuminating means comprising a lens plate in which a plurality of rectangular lenses are arranged in a matrix or in parallel is provided, and said uniform illuminating means is combined with said light source and said light source. A substantially parallel light irradiating means disposed between the prism sheets. 45. The substantially parallel light irradiating means according to claim 34, wherein the reflecting surface and the transmitting surface form a mosaic, mesh or the like distribution by forming the metal thin film in a mosaic or mesh pattern. Uniform illumination means provided with uniform illumination means formed of a transparent plate. 46. The substantially parallel light irradiating means according to claim 34, wherein said prism sheet has a triangular shape, a trapezoidal shape, a polygonal shape, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a semicircular shape, a hairline,
A substantially parallel light irradiating means having a plurality of fine prisms in a satin shape or the like and acting as a uniform illuminating means. 47. The substantially parallel light irradiating means according to claim 34, wherein said prism sheet has a triangular shape, a trapezoidal shape, a polygonal shape, a triangular pyramid, a polygonal pyramid, a cone, a truncated cone, a truncated cone, a hairline,
A substantially parallel light irradiating means having a plurality of fine prisms in a satin shape or the like, and also serving as a uniform illuminating means and a substantially parallel light irradiating means.