JP2005116266A - Illumination device, display device, and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination device in which color unevenness of an irradiated face is reduced with simple and easy constitution, and provide a display device and a projector with which this illumination device are equipped. <P>SOLUTION: This illumination device 100 is constituted of an LED101R for R light supplying the R light, an LED101G for G light supplying the G light, an LED101B for B light supplying the B light, and image forming optical systems 102R, 102G, and 102B which are installed at the respective LED101R, 101G, and 102B for respective color lights, and which form images of the LED101R, 101G, and 101B for the respective lights so that at least either one of the dimension and the shape of the images of the LED101R, 101G, and 101B for the respective color lights may be almost the same at the irradiated face 103 which is the prescribed face. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an illuminating device, in particular, an illuminating device using a solid light emitting element as a light source, a display device including the illuminating device, and a projector.

  In recent years, it has been proposed to use a solid state light emitting device such as a light emitting diode (LED) as a light source of a projector. Since the solid light emitting element emits light in a specific wavelength region, light with high color purity can be obtained. When a solid state light emitting device is used in a projector, unevenness in color occurs in an image projected on a screen due to variation in light emission luminance characteristics of each solid state light emitting device and variation in shape of a light emitting portion. A method for reducing such color unevenness is disclosed in, for example, the following patent documents.

JP 2000-155545 A JP 2001-209342 A

  However, Patent Document 1 requires a special kaleidoscope. In the configuration disclosed in Patent Document 2, a control system for correcting the drive signal of the light source is provided. As described above, in any of the documents, color unevenness cannot be reduced with a simple configuration, which is a problem.

  The present invention has been made in view of the above, and an object of the present invention is to provide an illumination device that reduces color unevenness of a surface to be irradiated with a simple configuration, a display device including the illumination device, and a projector.

  In order to solve the above-described problems and achieve the object, according to the first invention, at least two light emitting units that supply illumination light in different wavelength regions, and provided for each light emitting unit, emit light on a predetermined surface. It is possible to provide an illuminating device having an imaging optical system that forms an image of the light emitting portion so that at least one of the size and shape of the image of the portion is substantially the same.

  As the light emitting unit, for example, a solid light emitting element such as an LED can be used. The light emitting unit supplies light in different wavelength regions. When this illumination device is used as a light source of a projector, light in different wavelength regions from at least two light emitting units is irradiated onto an irradiated surface that is a predetermined surface or a conjugate surface thereof. At this time, the solid-state light-emitting elements may have different shapes and sizes of the electrode patterns of the light-emitting chips, shapes and sizes of bonding wires, shapes and sizes of bonding pads, and the like. Here, the shape means a shape including a shape and a position. In this case, the images of the plurality of light emitting portions on the predetermined surface have different sizes and shapes such as electrode patterns. Therefore, for example, the shape and size of an image of a light emitting unit that supplies red light (hereinafter referred to as “R light”) and an image of a light emitting unit that supplies green light (hereinafter referred to as “G light”). Will be different. As a result, color unevenness occurs. In contrast, in the first aspect of the invention, the imaging optics is provided for each light emitting unit and forms an image of the light emitting unit so that at least one of the size and shape of the image of the light emitting unit is substantially the same on a predetermined surface. A system has been established. As a result, at least one of the size and the shape of the image of each light emitting portion can be substantially matched on the predetermined surface or the irradiated surface which is a conjugate surface thereof. Preferably, it is desirable that both the size and the shape of the image of each light emitting unit are substantially matched. Thereby, it is possible to obtain illumination light with reduced color unevenness on a predetermined surface or an irradiated surface that is a conjugate surface thereof with a simple configuration.

  Further, according to a preferred aspect of the first invention, the light emitting section includes a first color light emitting section that supplies red light, a second color light emitting section that supplies green light, and a third light that supplies blue light. It is desirable to comprise a light emitting part for color light. 3 of a first color light emitting unit that supplies R light, a second color light source unit that supplies G light, and a third color light emitting unit that supplies blue light (hereinafter referred to as “B light”). By using two light emitting portions, full color illumination with high color purity can be performed.

  According to a preferred aspect of the first invention, it is desirable that the predetermined surface is divided into a plurality of regions, and a light emitting unit and an imaging optical system are provided for each region. Thereby, illumination light with reduced color unevenness can be supplied to a large predetermined surface. Moreover, the brightness (illuminance) can be changed for each region by adjusting the imaging optical system.

  According to a preferred aspect of the first aspect of the present invention, the rod further includes a rod that reflects the illumination light incident from the incident end face to the inner wall or the outer wall and emits the light from the exit end face. It is desirable that they are provided at the matching positions. The rod of this aspect functions as a so-called rod integrator. For this reason, it is possible to obtain illumination light in which uniform color unevenness is reduced on the exit end surface of the rod or its conjugate surface.

  Moreover, according to the preferable aspect of 1st invention, the lens array which consists of a some fly eye lens which divides illumination light into several partial light, and each condenses, and the superimposition lens which superimposes partial light on a to-be-irradiated surface It is desirable that the lens array be provided at a position where the fly-eye lens and the predetermined surface substantially coincide with each other. The lens array of this aspect functions as a so-called fly eye integrator. For this reason, it is possible to obtain illumination light in which uniform color unevenness is reduced on the irradiated surface of the lens array.

  In addition, according to the second invention, the illumination device described above and a spatial light modulation device that is provided at a position of a predetermined surface or a conjugate surface of the predetermined surface and modulates incident light according to an image signal. A characteristic display device can be provided. Thereby, for example, in a direct-view display device, a display image with reduced color unevenness can be obtained with a simple configuration.

  According to the third aspect of the invention, it is possible to provide a projector including the display device described above and a projection lens that projects the modulated light. Thereby, a projection image with reduced color unevenness can be obtained with a simple configuration.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example.

  FIG. 1 shows a schematic configuration of a lighting apparatus 100 according to Embodiment 1 of the present invention. The light emitting unit 101 is an R light LED 101R that is a first color light emitting unit that supplies R light, a G light LED 101G that is a second color light emitting unit that supplies G light, and a third light that supplies B light. It is composed of a B light LED 101B which is a color light emitting section. In addition, imaging optical systems 102R, 102G, and 102B are provided for the respective color light LEDs 101R, 101G, and 101B. In FIG. 1, the imaging optical systems 102R, 102G, and 102B are biconvex single lenses having a positive refractive power, but are not limited thereto, and may be an optical system including a plurality of lenses. The imaging optical systems 102R, 102G, and 102B have the sizes and shapes (including positions) of the images of the R light LED 101R, the G light LED 101G, and the B light LED 101B on the irradiated surface 103 that is a predetermined surface. Are imaged so that at least one of them is substantially the same.

  Further, the LEDs 101R, 101G, and 101B for the respective color lights are arranged on the irradiated surface 103 so that their images are substantially the same. For example, the R-color light LED 101R and the B-color light LED 101B are provided at symmetrical positions with the G-color light LED 101G as the center. Furthermore, the LED patterns for color light 101R, 101G, and 101B are arranged so that the electrode pattern, electrode shape, bonding wire position, and the like are aligned in the same direction.

  FIG. 2 shows an image on the irradiated surface 103 of the R light LED 101R. On the irradiated surface 103, as shown in FIG. 2, the electrode pattern 105 of the R light LED 101R and the bonding wire 104 are imaged by the imaging optical system 102R. The electrode pattern 105 and the bonding wire 104 of the G light LED 101G and the B light LED 101B are also formed so as to substantially overlap the image of the R light LED 101R. As described above, the size and shape (including position) of the electrode patterns and bonding wire images of the LEDs 101R, 101G, and 101B for the respective colors are substantially the same. For this reason, the color unevenness in the irradiated surface 103 can be reduced.

  In addition, the illumination device 100 illuminates using three solid-state light emitting elements of the R light LED 101R, the G light LED 101G, and the B light LED 101B. Thereby, full color illumination with high color purity can be performed.

  FIG. 3 shows a schematic configuration of a lighting apparatus 300 according to Embodiment 2 of the present invention. In this embodiment, the irradiated surface 103, which is a predetermined surface, is divided into three regions 103a, 103b, and 103c. Light emitting units 101X, 101Y, and 101Z are provided for the respective regions 103a, 103b, and 103c. Further, each of the light emitting units 101X, 101Y, and 101Z includes three color light LEDs 101R, 101G, and 101B and imaging optical systems 102R, 102G, and 102B as in the first embodiment.

  The rod lens 301 forms an image by relaying the irradiated surface 103 to a predetermined position. Thereby, illumination with reduced color unevenness can be performed on a surface conjugate with the irradiated surface 103. The configuration of the present embodiment is particularly suitable for illuminating the illuminated surface 103 in a large area. Further, the brightness (illuminance) for each region can be changed by adjusting the imaging optical systems 102R, 102G, and 102B for each of the light emitting units 101X, 101Y, and 101Z. Furthermore, the amount of illumination light from each of the light emitting units 101X, 101Y, and 101Z may be reduced at the periphery of the illumination area. Therefore, as shown in FIG. 3, it is desirable that each of the light emitting units 101X, 101Y, and 101Z illuminate a slightly larger area than each of the areas 103a, 103b, and 103c. Thereby, for example, the illumination light of both the light emitting unit 101X and the light emitting unit 101Y is irradiated in an overlapping manner at the boundary portion between the region 103a and the region 103b. As a result, even when the peripheral light amount of the illumination light from each of the light emitting units 101X, 101Y, and 101Z is decreased, the decrease in the illumination light amount can be reduced at the boundary portions of the regions 103a, 103b, and 103c.

  FIG. 4 shows a schematic configuration of a direct-view display device 400 according to the third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. The display device 400 includes a light emitting unit 101, a rod 401, a relay lens 402, and a liquid crystal light valve 403. The rod 401 is provided at a position where the irradiated surface 103, which is a predetermined surface, and the incident end surface 401a substantially coincide with each other. Each color light from the LED 101R for R light, the LED 101G for G light, and the LED 101B for B light is incident from an incident end surface 401a of a rod 401 having a quadrangular prism shape made of a glass material (BK7, quartz, etc.). Then, the illumination light is emitted from the emission end face 401b while being reflected on the outer wall using the total reflection condition of the interface at the outer wall of the rod 401. Thus, the so-called solid rod integrator, in which the light guide path is not hollow but is filled with a specific optical member, reflects and guides light according to the total reflection condition (TIR condition). For this reason, a reflectance of approximately 100% can be obtained at the interface. Therefore, the light transmission efficiency is improved as compared with the hollow rod integrator. The rod 401 is not limited to a rectangular column shape, and may be a hollow rod whose inner surface is formed of a reflective film.

  Since the rod 401 functions as a so-called rod integrator, uniform illumination light can be obtained in a superimposed manner on the exit end surface 401b of the rod 401 or its conjugate surface. The relay lens 402 images the exit end surface 401b of the rod 401 on a conjugate plane. A transmissive liquid crystal light valve 403, which is a spatial light modulator, is provided on the conjugate plane. The liquid crystal light valve modulates the illumination light according to the image signal and emits it. Each of the color light LEDs 101R, 101G, and 101B is turned on in order to illuminate the liquid crystal light valve 403. An observer observes a full-color image by temporally integrating modulated light of R light, G light, and B light.

  In this configuration, illumination light with reduced uniform color unevenness can be obtained on the exit end surface 401b of the rod 401 or its conjugate surface. Further, on the incident end surface 401a of the rod 401, the size and shape (including position) of the LEDs 101R, 101G, and 101B for the respective color lights are substantially the same. For this reason, since the color unevenness in the irradiated surface 103 can be reduced, the observer can observe a high-quality display image from the arrow A direction.

  Further, in order to sequentially project the R light, the G light, and the B light to obtain a white projected image as a whole, the light flux amount of the G light is set to about 60% to 80% with respect to the total light flux amount. There is a need. For this reason, when the same number of LEDs for R light, B light, and G light are arranged, the lighting time of the G light LED 101G is set to be longer than the lighting time of the R light and B light LEDs. It is desirable to lengthen or increase the drive current of the G light LED 101G to increase the emission intensity compared to the R light and B light LEDs.

  FIG. 5 shows a schematic configuration of a projector 500 according to Embodiment 4 of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. The projector 500 includes a light emitting unit 101, a collimating lens 501, fly-eye lenses 502 and 503, a superimposing lens 504, a transmissive liquid crystal light valve 505, and a projection lens 506.

  The collimating lens converts R light, G light, and B light from the light emitting unit 101 into substantially parallel light and guides it to the fly-eye lens 502. The fly-eye lenses 502 and 503 are lens arrays in which minute lenses having a rectangular outline are arranged in a matrix. When viewed from the optical axis direction, the outer shape of each microlens is an image forming region of a liquid crystal light valve 505 that is a spatial light modulator that modulates illumination light based on an electrical signal to form image light. The outer shape is configured to be substantially the same shape.

  The fly-eye lens 502 divides the illumination light emitted from the light emitting unit 101 into a plurality of partial lights, and collects the partial light on each minute lens of the fly-eye lens 503. The fly-eye lens 503 emits the divided partial light for each partial light and makes it enter the superimposing lens 504. The superimposing lens 504 superimposes the divided partial light and irradiates the liquid crystal light valve 505. Furthermore, the superimposing lens 504 may superimpose illumination light on a surface conjugate with the image forming area as well as the image forming area of the liquid crystal light valve 505. When the illumination light is superimposed on a surface conjugate with the image forming area, the superimposed illumination light is imaged on the image forming area using a relay optical system or a relay imaging unit. Each of the color light LEDs 101R, 101G, and 101B is turned on in order to illuminate the liquid crystal light valve 403. The projection lens 506 projects the light modulated by the liquid crystal light valve 505 onto the screen 507. An observer can observe a full-color image because the modulated light of R light, G light, and B light is integrated by time and recognized.

  Here, the fly-eye lens 502 is provided at a position substantially coinciding with the irradiated surface 103 that is a predetermined surface. A lens array including the fly-eye lenses 502 and 503 functions as a so-called fly-eye integrator. For this reason, uniform illumination light can be obtained on the superimposed surface of illumination light from the lens array. Furthermore, on the incident end surface of the fly-eye lens 502, the size and shape (including position) of the LEDs 101R, 101G, and 101B for each color light are substantially the same. For this reason, it is possible to reduce color unevenness on the irradiated surface 103 and the superimposed surface that is a conjugate surface thereof. Thereby, the observer can observe a high-quality projected image with reduced color unevenness on the screen 507.

  Finally, the arrangement, shape, form, size, etc. in the lens array, superimposing lens, rod, imaging optical system, liquid crystal light valve, etc. that have been shown as examples of the present invention are the optical systems used in each example. However, the present invention may be applied to other optical systems without departing from the gist of the present invention. Further, the spatial light modulator is not limited to the liquid crystal light valve. For example, DMD (manufactured by Texas Instruments) can be used.

  As described above, the lighting device according to the present invention is useful for a device using a solid light-emitting element, and is particularly suitable for a direct-view display device or projector.

1 is a diagram illustrating a schematic configuration of a lighting device according to Embodiment 1. FIG. FIG. 3 is a diagram illustrating a light source image of the illumination device according to the first embodiment. FIG. 6 is a diagram illustrating a schematic configuration of a lighting device according to a second embodiment. FIG. 6 is a diagram illustrating a schematic configuration of a display device according to a third embodiment. FIG. 10 is a diagram illustrating a schematic configuration of a projector according to a fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Illumination device, 101R, 101G, 101B, LED for each color light, 102R, 102G, 102B Imaging optical system, 103 Irradiation surface, 101X, 101Y, 101B Light emission part, 103a, 103b, 103c Each area, 104 Bonding wire, 105 electrode pattern, 300 illumination device, 301 rod lens, 400 display device, 401 rod, 401b emission end surface, 401a incident end surface, 402 relay lens, 403 liquid crystal light valve, 500 projector, 501 collimating lens, 502 fly eye lens, 503 Fly-eye lens, 504 superimposing lens, 505 liquid crystal light valve, 506 projection lens, 507 screen

Claims (7)

At least two light emitting units for supplying illumination light in different wavelength regions;
An imaging optical system provided for each of the light emitting units and configured to form an image of the light emitting unit so that at least one of a size and a shape of an image of the light emitting unit is substantially the same on a predetermined surface; Lighting device.   The light emitting unit includes a first color light emitting unit that supplies red light, a second color light emitting unit that supplies green light, and a third color light emitting unit that supplies blue light. The lighting device according to claim 1.   The illumination device according to claim 1, wherein the predetermined surface is divided into a plurality of regions, and the light emitting unit and the imaging optical system are provided for each region. A rod that reflects the illumination light incident from the incident end face to the inner wall or the outer wall and emits the light from the exit end face;
The lighting device according to any one of claims 1 to 3, wherein the rod is provided at a position where the predetermined surface and the incident end surface substantially coincide with each other. A lens array composed of a plurality of fly-eye lenses that divide the illumination light into a plurality of partial lights and condense them respectively;
A superimposing lens that superimposes the partial light on the irradiated surface;
The illumination device according to any one of claims 1 to 3, wherein the lens array is provided at a position where the fly-eye lens and the predetermined surface substantially coincide with each other. The illumination device according to any one of claims 1 to 5,
A display device comprising: a spatial light modulation device that is provided at a position of the predetermined surface or a conjugate surface of the predetermined surface and modulates incident light according to an image signal. A display device according to claim 6;
A projector having a projection lens for projecting modulated light.

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