JP2004341554A - Projection type color liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type color liquid crystal display device realizing higher luminance by improving the utilization rate of light from a light source. <P>SOLUTION: The projection type color liquid crystal display device is equipped with a red light source where a plurality of red LEDs are two-dimensionally arrayed on an insulating base plate and which is parallel converged by a microlens array, a display panel for red 26 irradiated with the light from the red light source and modulating a red image, a green light source where a plurality of green LEDs are two-dimensionally arrayed on an insulating base plate and which is parallel converged by a microlens array, a display panel for green 25 irradiated with the light from the green light source and modulating a green image, a blue light source where a plurality of blue LEDs are two-dimensionally arrayed on an insulating base plate and which is parallel converged by a microlens array, a display panel for blue 24 irradiated with the light from the blue light source and modulating a blue image, an optical means 27 composing video light transmitted through the respective display panels and a projection lens 28 projecting a color image composed by the optical means 27 to a screen 29. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projection type color liquid crystal display device.

  FIG. 8 is a schematic configuration diagram showing an internal structure of a projection type color liquid crystal display device that projects a color image on a screen. As shown in FIG. 8, in this projection type color liquid crystal display device, white light is emitted from a light source 1 and this light is passed through two dichroic mirrors 2 and 3 into three optical paths for red, green and blue. Is divided into Liquid crystal panels 4, 5, and 6 are arranged on each optical path, and red (R) and green (G) obtained by passing light on images formed on the panels 4, 5, and 6 are obtained. , Blue (B) image light are collected on one output optical path by two mirrors 7 and 8 and two dichroic mirrors 9 and 10. Thereby, the red image, the green image, and the blue image are superimposed, and the color image formed by the superimposition is projected on the screen 12 via the projection lens 11.

  In the above-mentioned conventional projection type color liquid crystal display device, a combination of a lamp 1a such as a metal halide lamp or a xenon lamp and a reflector 1b is used as a light source 1, as shown in FIG.

  By the way, the projection type color liquid crystal display device is configured to irradiate the liquid crystal panel 4 (5, 6) with the light of the light source 1 as parallel light. However, the projection type color liquid crystal display device is different from a conventional lamp 1a such as a metal halide lamp or a xenon lamp. For this reason, the arc length is about 2 mm, and the light spreads with a divergence angle of 6 to 8 degrees at present in proportion to the arc length.

  However, there is a problem that the spread of the light from the light source 1 causes color shift and color unevenness. Further, there is a problem that the utilization rate of light including the projection lens 11 is reduced.

  In addition, Japanese Patent Application Laid-Open No. 8-19095 (IPC: G02F 1/1335) proposes a parallel light source for a liquid crystal display device using a hologram color filter. This light source comprises a micro focusing lens array and a white micro primary light source disposed at the focal point of each micro lens or at an off-axis position thereof, and generates substantially parallel light to be incident on the liquid crystal display device.

  However, the above-mentioned light source is white light, and in order to use the light source in a color liquid crystal display device, it is necessary to separate white light into three primary colors of red, green and blue by a hologram color filter or the like, and the number of parts increases. There are difficulties. Further, since white light is separated into light of three colors, the light given to the liquid crystal display device is one-third of the light emitted from the light source, and there is a limit in increasing the luminance.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a projection-type color liquid crystal display device capable of improving the utilization rate of light from a light source and achieving high luminance, in consideration of the above-described conventional problems.

  The present invention relates to an optical device in which a plurality of red light-emitting elements are two-dimensionally arranged on a front surface of an insulating substrate on which a heat sink is mounted on a back surface, and light from the red light-emitting elements is arranged on a front surface of the light-emitting element. A red light source parallel-converged by the element, a red display panel that emits light from this red light source to modulate a red image, and a green light-emitting element on the surface of an insulating substrate with a heat sink attached to the back side Are arranged two-dimensionally, and a green light source in which light from the green light-emitting element is collimated and converged by an optical element disposed in front of the light-emitting element, and a green light emitted by the light from the green light source. A green display panel for modulating an image and a plurality of blue light-emitting elements are two-dimensionally arranged on the surface of an insulating substrate on which a heat sink is mounted on the back side, and light from the blue light-emitting elements is used as a light-emitting element. Front A blue light source collimated by the arranged optical elements, a blue display panel irradiated with light from the blue light source to modulate a blue image, and an optical unit for combining video light transmitted through each of the display panels And a projection lens for projecting the color image synthesized by the optical means onto a screen.

  It is preferable that the light-emitting elements of the respective colors are arranged at a pitch shifted by one row, and the optical elements arranged on the front surface of the light-emitting elements are formed in a turtle-shape.

  Further, each of the display panels can be mounted on each light source.

  As described above, since the light-emitting element including the light-emitting diode used as the light source of the liquid crystal display device of the present invention is a point light source capable of performing a uniform display in a wide color reproduction range, the optical element is disposed in front of the light source. By doing so, the dispersion angle can be reduced, illumination light that is very close to parallel can be obtained, and the light use efficiency can be improved.

  In addition, the projection type color liquid crystal display device of the present invention using the above-described light source can provide illumination light that is extremely parallel to each display panel, can eliminate color shift and color unevenness, and can reduce the light utilization rate. Is improved. In addition, since red, green, and blue light can be directly applied to the display panel, loss of light due to light separating means and the like can be eliminated, and a projection type color liquid crystal display device with high light utilization can be provided. be able to.

  In addition, by attaching a heat sink to the back surface of the insulating substrate, heat of the light emitting element can be efficiently radiated from the heat sink.

  Furthermore, the light emitting elements of each color are arranged with a pitch shift by one row, and the optical elements arranged on the front surface of the light emitting elements are formed in a turtle-shape, so that unevenness of light due to periodicity can be reduced.

  Hereinafter, the present invention will be described with reference to the drawings showing an embodiment thereof. FIG. 1 is a schematic plan view showing a first light source used in the present invention, and FIG. 2 is a schematic side view thereof.

  As shown in the drawing, the light source 20 has a light emitting diode (LED) 21 as a plurality of light emitting elements arranged two-dimensionally on an insulating substrate 22. A microlens array 23 as an optical element is mounted in accordance with the arrangement of the light emitting diodes 21. Each light emitting diode 21 is a point light source capable of performing uniform display in the color reproduction range, and the light emitted from the light emitting point of the light emitting diode 21 is collimated by the microlens array 23 so that the dispersion angle is reduced and the parallel light is reduced. Illumination light very close to

  When the light source 20 is used as illumination light of about 200 W of a metal halide lamp for irradiating a liquid crystal panel equivalent to 2 inches, 1000-1500 light emitting diodes on an insulating substrate 22 of about 30 mm × 40 mm at about 1 mm pitch. 21 may be arranged two-dimensionally.

  When the light source 20 described above is used in a three-panel projection type color liquid crystal display device, a light source in which a red light emitting diode is two-dimensionally arranged as a light source for irradiating a liquid crystal panel on which a red image is displayed is replaced with a green light source. A two-dimensional arrangement of green light-emitting diodes is used as a light source for irradiating a liquid crystal panel on which an image is displayed, and a two-dimensional arrangement of blue light-emitting diodes is used as a light source for irradiating a liquid crystal panel on which a blue image is displayed. It is good to prepare what you did.

  FIG. 3 is a schematic side view showing a second light source used in the present invention.

  As shown in FIG. 3, in the light source 20a, a red light emitting diode 21R, a green light emitting diode 21G, and a blue light emitting diode 21B as light emitting elements are two-dimensionally arranged on an insulating substrate 22. A microlens array 23a as an optical element is mounted in accordance with the arrangement of the light emitting diodes 21R, 21G, and 21B. The microlens array 23a is configured to emit light at different angles according to each color component. Each color light emitting diode 21R, 21G, 21B is a point light source capable of uniform display in the color reproduction range, and the light emitted from the light emitting point of the light emitting diode 21R, 21G, 21B is collimated at a predetermined angle by the micro lens array 23a. Thus, illumination light having a small dispersion angle and an angle corresponding to the color component can be obtained.

  A heat sink 24 is mounted on the back surface of the insulating substrate 22, and is configured to radiate heat of the light emitting diodes 21 R, 21 G, and 21 B from the heat sink 24.

  When the light source 20a is used as illumination light of about 200 W of a metal halide lamp for irradiating a liquid crystal panel equivalent to 2 inches, 1000-1500 light emitting diodes on an insulating substrate 22 of about 30 mm × 40 mm at about 1 mm pitch. 21R, 21G and 21B may be arranged two-dimensionally.

  FIG. 4 is a schematic plan view showing a third light source used in the present invention. In this light source, the light emitting diodes 21 (21R, 21G, 21B) are arranged so as to be shifted by a half pitch line by line, and the microlens array 23 (23a) is formed in a tortoiseshell shape. With such a configuration, light unevenness due to periodicity can be reduced.

When a white light source is obtained with the light source 20 described above, red, blue, and green light emitting diodes 21 are randomly and two-dimensionally arranged, and a diffusing plate is provided on the entire surface of the microlens array 23 to form a red, blue, and green light emitting diode.
What is necessary is just to comprise so that green and blue may be combined.

  Next, an embodiment of the projection type color liquid crystal display device of the present invention will be described with reference to FIG.

  As shown in FIG. 5, a red light emitting diode is two-dimensionally arranged on an insulating substrate, and a light source 20 (R) having a microlens array mounted thereon is prepared. A liquid crystal panel 26 on which a red image is displayed is mounted on the light source 20 (R). Then, the light emitted from the red light emitting diode and emitted as a parallel light by the microlens array passes on an image formed on the liquid crystal panel 26 and is given to the dichroic prism 27 as red (R) image light. .

  Also, a light source 20 (G) having a green light emitting diode two-dimensionally arranged on an insulating substrate and a microlens array mounted thereon is prepared. A liquid crystal panel 25 on which a green image is displayed is mounted on the light source 20 (G). Then, the light emitted from the green light-emitting diode and emitted as parallel light by the microlens array passes through an image formed on the liquid crystal panel 25 and is provided to the dichroic prism 27 as green (G) image light.

  Further, a blue light emitting diode is two-dimensionally arranged on an insulating substrate, and a light source 20 (B) having a microlens array mounted thereon is prepared. A liquid crystal panel 24 on which a green image is displayed is mounted on the light source 20 (B). The light emitted from the blue light emitting diode and collimated by the microlens array passes through an image formed on the liquid crystal panel 24 and is provided to the dichroic prism 27 as blue (B) image light.

  The red (R), green (G), and blue (B) image lights are collected on one output optical path by the dichroic prism 27. Thereby, the red image, the green image, and the blue image are superimposed, and the color image formed by the superimposition is projected onto the screen 12 via the projection lens 28.

  The light intensity of each of the light sources 20 (R), 20 (G) and 20 (B) may be controlled by controlling the current applied to the light emitting diode.

  Next, a reference example of a projection type color liquid crystal display device using this light source will be described with reference to FIG.

  As shown in FIG. 6, a red light emitting diode is two-dimensionally arranged on an insulating substrate, and a light source 20 (R) having a microlens array mounted thereon is prepared. Then, the light emitted from the red light emitting diode and emitted from the light source 20 (R) as a parallel light by the microlens array is provided to the dichroic mirror 30 a and the dichroic mirror 30 b as the color combining means 30. The dichroic mirror 30a reflects blue light and transmits red light and green light. The dichroic mirror 30b has a property of reflecting red light and transmitting green light and blue light. The red light emitted from the light source 20 (R) is reflected by the dichroic mirror 30b and guided toward the micro lens array 31 at a predetermined angle.

  Also, a light source 20 (G) having a green light emitting diode two-dimensionally arranged on an insulating substrate and a microlens array mounted thereon is prepared. Then, the light emitted from the green light emitting diode is converted into a parallel light by the microlens array, and the light from the light source 20 (G) is provided to the color combining unit 30. Green light emitted from the light source 20 (G) passes through the dichroic mirrors 30 a and 30 b and is provided to the microlens array 31.

Further, a blue light emitting diode is two-dimensionally arranged on an insulating substrate, and a light source 20 (B) having a microlens array mounted thereon is prepared. The light emitted from the blue light emitting diode and collimated by the microlens array from the light source 20 (B) is
0 is given. The blue light emitted from the light source 20 (B) is reflected by the dichroic mirror 30a and guided toward the microlens array 31 at a predetermined angle.

  That is, the light emitted from the light sources 20 (R), 20 (G), and 20 (B) is condensed by the color synthesizing means 30 including the two dichroic mirrors 30a and 30b, and the light is microscopically dispersed at a dispersion angle corresponding to each color. The angles of the dichroic mirrors 30a and 30b are adjusted so that the light is emitted to the lens array 31.

  The angles of the red light (R), green light (G), and blue light (B) emitted by the color synthesizing unit 30 are different from each other, and these color components are focused at different positions by the microlens array 31. In the liquid crystal panel 32, pixel portions corresponding to the respective color components are formed at positions where the liquid crystal panel 32 converges. Accordingly, the red component focused by the microlens array 31 is a red (R) pixel portion of the liquid crystal panel 32, the green component is a green (G) pixel portion of the liquid crystal panel 32, and the blue component is a blue (B) pixel of the liquid crystal panel 32. Through the department. Then, the light passes through each of the pixel portions of the liquid crystal panel 32, and an image modulated and formed by the liquid crystal panel 32 is enlarged by a projection lens (not shown) and projected on a screen.

  Still another reference example of a projection type color liquid crystal display device using the above light source will be described with reference to FIG.

  The projection type color liquid crystal display device shown in FIG. 7 uses the light source 20a shown in FIG. As described above, each light emitted from the red light emitting diode 21R, the green light emitting diode 21G, and the blue light emitting diode 21B of the light source 20a is transmitted to the front surface of the liquid crystal panel 31 at a different angle according to each color component by the microlens array 23a. The light is emitted toward the provided microlens array 31. The angles of the red light (R), green light (G), and blue light (B) emitted from the microlens array 23a are different from each other, and these color components are focused by the microlens array 31 at different positions. As described above, in the liquid crystal panel 32, pixel portions corresponding to the respective color components are formed at positions converged by the microlens array 31. Accordingly, the red component focused by the microlens array 31 is a red (R) pixel portion of the liquid crystal panel 32, the green component is a green (G) pixel portion of the liquid crystal panel 32, and the blue component is a blue (B) pixel of the liquid crystal panel 32. Through the department. Then, the light passes through each of the pixel portions of the liquid crystal panel 32, and an image modulated and formed by the liquid crystal panel 32 is enlarged by a projection lens (not shown) and projected on a screen.

  In the above-described example, a light emitting diode is used as the light emitting element, but another light emitting element such as an organic or inorganic EL (electroluminescence), a semiconductor laser, or the like can be used.

FIG. 2 is a schematic plan view showing a first light source used in the present invention. FIG. 2 is a schematic side view showing a first light source used in the present invention. FIG. 3 is a schematic side view showing a second light source used in the present invention. FIG. 5 is a schematic plan view showing a third light source used in the present invention. 1 is a schematic configuration diagram illustrating a projection type color liquid crystal display device according to an embodiment of the present invention. 1 is a schematic configuration diagram showing a projection type liquid crystal display device according to a reference example of the present invention. FIG. 10 is a schematic configuration diagram showing a projection type liquid crystal display device according to still another reference example of the present invention. FIG. 1 is a schematic configuration diagram illustrating an internal structure of a projection type color liquid crystal display device that projects a color image on a screen. It is a schematic block diagram which shows the conventional light source.

Explanation of reference numerals

Reference Signs List 20 light source 20a light source 21 light emitting diode 21R red light emitting diode 21G green light emitting diode 21B blue light emitting diode 22 insulating substrate 23 micro lens array 24 heat sink 20 (R) light source for red 20 (G) light source for green 20 (B) light source for blue 24, 25, 26 Liquid crystal panel 27 Dichroic prism 28 Projection lens 29 Screen 30 Color synthesizing means 30a Dichroic mirror 30b Dichroic mirror 31 Micro lens array 32 Liquid crystal panel

Claims (3)

A plurality of red light emitting elements are two-dimensionally arranged on the surface of an insulating substrate on which a heat sink is mounted on the back side, and light from the red light emitting elements is parallelized by an optical element arranged on the front surface of the light emitting element. A converged red light source, a red display panel irradiated with light from the red light source to modulate a red image, and a plurality of green light emitting elements 2 on a surface of an insulating substrate on which a heat sink is mounted on the back side. A green light source is arranged in a two-dimensional manner, and the light from the green light emitting element is converged in parallel by an optical element arranged in front of the light emitting element, and the light from the green light source is irradiated to modulate a green image. A plurality of blue light-emitting elements are two-dimensionally arranged on the surface of an insulating substrate having a green display panel and a heat sink on the back side, and light from the blue light-emitting elements is arranged on the front of the light-emitting elements. Was A blue light source parallel-converged by the optical element, a blue display panel irradiated with light from the blue light source and modulating a blue image, and optical means for synthesizing image light transmitted through each display panel, A projection lens for projecting a color image synthesized by an optical unit onto a screen. 2. The projection type color liquid crystal according to claim 1, wherein the light emitting elements of each color are arranged with a pitch shifted by one row, and an optical element arranged in front of the light emitting element is formed in a turtle-shape. Display device. 3. The projection type color liquid crystal display device according to claim 1, wherein each of the display panels is mounted on each light source.

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