JPH10269802A - Lighting system and image display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce consumption of power, miniaturize a unit, and gain even illuminance distribution, by prolonging the life of a light source and improving utilization efficiency of light. SOLUTION: Each illumination light of red, green, and blue, emitted from light-emitting diodes 11R, 11G, and 11B is equalized by colored scopes 12R, 12G, and 12B respectively, projected on image display light bulbs 21R, 21G, and 21B per color through a relay lens and a field lens, specially intensity- modulated, compounded by a composite prism 20, and magnification projected on a screen 26 by a projection lens 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device for performing uniform illumination, and an image display device for displaying an image by spatially modulating light from the illuminating device and projecting the light onto a screen or the like. About.

[0002]

2. Description of the Related Art Conventionally, as an image display device used for the purpose of viewing an image, a projection type in which light emitted from a light source is spatially modulated by an image display light valve and an image is projected on a screen or the like. There is a video display device. As one of the projection type image display devices, there is a liquid crystal projector using a transmission type liquid crystal panel as an image display light valve, which has been practically used because of its small size and light weight.

In a conventional liquid crystal projector, a white light source such as a discharge-type xenon lamp, a metal halide lamp, or a heat-emitting halogen lamp is used as a light source. The white light emitted from the light source is ultraviolet (UV) and infrared light. Unnecessary light is removed by a UV-IR cut filter that cuts (IR), and red (hereinafter, also referred to as R) and green (hereinafter, G) by a dichroic mirror or the like that transmits or reflects light of a specific wavelength component. ) And blue (hereinafter, also referred to as B). Each of the separated lights passes through three liquid crystal panels as a spatial light modulator on which an image is formed according to each signal corresponding to the three primary colors, and is then combined by a combining optical system to form a full-color image. The projection lens enlarges and projects the image on a front transmission or reflection screen.

[0004]

By the way, in the projection type image display device using a lamp such as a xenon lamp, a metal halide lamp and a halogen lamp as described above, the power consumption of the lamp is large and the light use efficiency is improved. However, there is a problem that the size of the apparatus is increased by using many optical components. In addition, the lamp has a problem that the lamp needs to be frequently replaced because its brightness changes greatly with time and its life is relatively short.

Further, in the conventional projection type image display apparatus, since the wavelength distribution exists in the light emitted from the lamp, the wavelength distribution of each color separated depends on the wavelength distribution of the light emitted from the lamp, and good color reproduction is achieved. There was a problem that it was difficult.

[0006] Further, in a projection type video display device such as a liquid crystal projector, improvement and uniformity of display luminance have been problems. In order to equalize the display luminance, it is necessary to equalize the illuminance of the illumination light with respect to the image display light valve. However, in a typical liquid crystal projector, for example, the radiation of a metal halide lamp is collimated by a parabolic reflector, and
Since the liquid crystal panel is illuminated, color unevenness due to uneven light emission of the lamp occurs on the display screen, and the central part of the display screen becomes considerably brighter than the peripheral part.
There is a problem that the display quality is inferior to that of an image when the T (cathode ray tube) is viewed directly.

[0007] To improve the display brightness, it is necessary to improve the light use efficiency and the lamp. At the current level, light utilization is only a few percent, wasting most of the light. Therefore, if this is improved, the display luminance is improved and the power consumption is reduced. Recently, in order to ensure brightness, a high-output lamp (xenon lamp, metal halide lamp) and a point light source with high luminous efficiency, which can easily extract parallel light, have been developed. However, when the luminous efficiency of the lamp is improved, there is a problem in that there is a reciprocal relationship that the current increases and the life is shortened. On the other hand, regarding light utilization efficiency, since there is a spectral distribution in the emitted light of the lamp, necessary R, G,
There is a problem that a large amount of light is discarded when color separation into the three primary colors B is performed.

Further, in the conventional projection type video display device, since a light use efficiency is low, a large lamp must be used in order to obtain necessary brightness, and as a result, the projection type video display device is required. However, there is a problem that the size becomes large.

The present invention has been made in view of the above problems, and a first object of the present invention is to increase the life of a light source, improve light use efficiency, reduce power consumption, and reduce the size of an apparatus. Another object of the present invention is to provide a lighting device having a uniform illuminance distribution.

A second object of the present invention is to provide a light source having a long life, an improved light use efficiency, a reduction in power consumption and a reduction in the size of the apparatus, and an excellent color reproduction.
An object of the present invention is to provide a video display device having a uniform display luminance.

[0011]

According to a first aspect of the present invention, there is provided a lighting device, comprising: a light source using one or more light emitting diodes for emitting light to be illuminated to an illuminated portion; And an illuminance equalizing optical element for equalizing the illuminance in the section.

According to a sixth aspect of the present invention, there is provided an image display apparatus, comprising: a spatial modulation means for spatially modulating light to be irradiated in accordance with information of an image to be displayed to form an image; A light source using one or more light emitting diodes for emitting light, an illuminance equalizing optical element for equalizing the illuminance of the light emitted from the light source in the spatial modulation means, and a light modulated by the spatial modulation means. And a projection optical system for projecting the reflected light.

In the illumination device according to the first aspect, light emitted from a light source using one or more light emitting diodes is illuminated by an illuminance equalizing optical element such that the illuminance in the illuminated portion is equalized. The light is emitted to the lighting unit.

In the image display device according to the present invention, the light emitted from the light source using one or more light emitting diodes is made uniform by the illuminance uniforming optical element so that the illuminance in the spatial modulation means is made uniform. The light is radiated to the spatial modulation means, spatially modulated by the spatial modulation means according to the information of the image to be displayed, and projected by the projection optical system.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing the configuration of the lighting device according to the first embodiment of the present invention. The lighting device according to the present embodiment has one light emitting diode 1 as a light source that emits light to be irradiated on an illuminated part.
1 and a rod-type optical integrator (hereinafter, referred to as a KALEIDOSCOPE) 12 as an illuminance equalizing optical element for equalizing the illuminance of the light emitted from the light emitting diode 11 in the illuminated portion.
And The kaleidoscope 12 is made of a glass rod having a certain length, and has one end face (incident end face).
The incident light is made uniform and emitted from the other end face (emission end face). The kaleidoscope 12 may have a columnar shape such as a quadrangular columnar shape or a hexagonal columnar shape. In the example shown in FIG. 1, the kaleidoscope 12 has a rectangular columnar shape. Light emitting diode 11
Are joined to the incident end face of the kaleidoscope 12 such that the light emitting surface faces the incident end face of the kaleidoscope 12. In the lighting device shown in FIG. 1, the light emitting diode 11 having substantially the same shape and the same size as the incident end face of the kaleidoscope 12 is used. However, as shown in FIG. A light emitting diode 11 having a shape similar to that of the above and smaller than the shape of the incident end face may be used.

Here, the principle of illuminance uniformization in the kaleidoscope 12 will be described with reference to FIG. In the kaleidoscope 12, the light incident at an angle with respect to the optical axis 13 on the incident end face 12 a is emitted from the emission end face 12 b by repeating total reflection on the side face of the kaleidoscope 12. Here, the number of reflections is Kaleidoscope 1.
2, and as a result, the lights having different numbers of reflections are mixed and become uniform outgoing light at the outgoing end face 12b (refer to the document “Optical Technology Contact”, Vo).
l. 33, No. 2, 1995, pp. 41-44 "
reference. ).

The lighting device according to the present embodiment can be used for a device that requires uniform illuminance in a portion to be illuminated, for example, a projection type image display device. Here, in the present application, a projection-type image display device refers to a device that projects spatially modulated light onto a screen, such as a liquid crystal projector, and a spatially modulated light, such as a head-mounted display. There is also a virtual image display type image display device that projects the light emitted to the human eye, and an exposure device that projects spatially modulated light onto a resist on a semiconductor wafer, such as a step-type projection exposure device. Shall be included.

When the illumination device according to the present embodiment is used for a projection type video display device for viewing, a device that emits visible light is used as the light emitting diode 11. When the illumination device according to the present embodiment is used for an exposure device, the illumination light does not need to be visible light, and may be ultraviolet light or the like. In this case, the light emitting diode 11 may be an ultraviolet light or the like. A device that emits light in a necessary wavelength range is used.

When the illumination device according to the present embodiment is used for a projection type video display device for full-color viewing, the use of three primary colors of R, G, and B as illumination light is considered from the viewpoint of color reproducibility. The most effective to see. Therefore, in the following description,
The case where three primary colors of R, G, and B are used as the illumination light will be described.

The light emitting diode 11 uses, for example, an AlGaPAs-based compound semiconductor for red light emission, and uses, for example, a GaN-based or ZnSe-based compound semiconductor for green light emission and blue light emission. Use things.

The light emitting diode 11 is used in the form of a so-called bare chip. At present, the size of the light emitting surface of a commercially available light emitting diode is 0.2 to 0.5 mm square, but the lighting device according to the present embodiment is used for a projection type video display device for viewing. In this case, the light emitting diode 11 in the present embodiment preferably has a size of about several mm square, although it differs depending on the material such as the external quantum efficiency of the compound semiconductor. A bare chip having a size is prepared and used.

The shape of the light-emitting surface of the light-emitting diode 11 and the cross-section of the kaleidoscope 12 may be arbitrary, for example, a square, a hexagon, a circle, etc., but the projection-type image display device for viewing the illumination device according to the present embodiment. If you use
In both cases, it is preferable to make the shape similar to the shape of the image display area of the light valve to be illuminated. By adopting such a shape, the cross-sectional shape of the light beam applied to the image display area of the light valve can be made to have a shape corresponding to the image display area. As a result, the light emitted from the light emitting diode 11 It will be used effectively and the light use efficiency will be improved. Further, by making the light emitting surface of the light emitting diode 11 and the cross section of the kaleidoscope 12 have substantially the same shape, the highest luminance and efficiency can be obtained as the light emitted from the kaleidoscope 12. Therefore, for example, if the aspect ratio of the image display area of the light valve is 3: 4 similar to that of the current monitor, the aspect ratio of the light emitting surface of the light emitting diode 11 and the cross section of the kaleidoscope 12 is also 3: 4.
When the image display area of the light valve has the same aspect ratio of 9:16 as that of HDTV, the shape of the light emitting surface of the light emitting diode 11 and the cross section of the kaleidoscope 12 also have the aspect ratio of 9:16. Is preferred.

The material of the kaleidoscope 12 is optical glass. The length of the kaleidoscope 12 is determined in consideration of the number of times of total reflection of light, but is preferably about several tens mm to several hundred mm.

Next, an example of a method of joining the light emitting diode 11 and the kaleidoscope 12 in the lighting device according to the present embodiment will be described with reference to FIGS. FIG. 3 and FIG. 4 are cross-sectional views showing a joint portion between the light emitting diode 11 and the kaleidoscope 12. In the example shown in FIG. 3, a reflecting mirror 15 serving also as an electrode having a shape that forms a part of a spherical surface is provided on the surface opposite to the light emitting surface of the light emitting diode 11, And the reflector 15 are connected to leads 16 and 17, respectively. In this example, for example, a light-emitting diode 1
After mounting the bare chip on the reflecting mirror 15 and performing electrode wiring, the light emitting diode 11 and the reflecting mirror 15 are incident on the kaleidoscope 12 such that the light emitting surface of the light emitting diode 11 faces the incident end face of the kaleidoscope 12. Joined to the end face. For mounting the bare chip of the light-emitting diode 11, a light-emitting diode mounting technology that is currently commercially available can be used.

In the example shown in FIG.
A metal reflection film 19 is formed on the surface opposite to the light emitting surface of the LED, and leads 16 and 17 are connected to the light emitting surface of the light emitting diode 11 and the surface on the opposite side, respectively. In this example, for example, after forming and wiring the metal reflection film 19 on the bare chip of the light emitting diode 11 formed in a predetermined size, the light emitting surface is arranged so as to face the incident end surface of the kaleidoscope 12, By epoxy resin 18 etc.
It is directly joined to the incident end face of the kaleidoscope 12.

Next, the operation of the lighting device according to the present embodiment will be described. In the lighting device according to the present embodiment,
The light emitted from the light-emitting diode 11 enters the inside of the kaleidoscope 12 from the incident end face, repeats total reflection on the side face of the kaleidoscope 12, and is emitted as uniform light from the emission end face. The emitted light is uniformly applied to an illuminated portion such as an image display area of the light valve.

According to the illuminating device of the present embodiment, since the light emitting diode 11 is used as the light source, the life of the light source is extended. Therefore, the work of replacing the light source can be reduced.

When the illumination device according to the present embodiment is used in a projection type video display device for full-color viewing, light discarded when color separation is performed, such as when a white light source is used as a light source. And the light use efficiency can be improved. As a result, power consumption can be reduced and the size of the image display device can be reduced as compared with the case where a white light source is used as the light source.

By the way, the light emitting diode 11 is used as a light source.
Although the above-described effects can be obtained by using, the current density in the light emitting surface is different in the light emitting surface due to the presence of the electrode part on the light emitting surface side of the light emitting diode 11. As a result, the light emitted from the light emitting diode 11 may have uneven brightness. As a result,
The illuminance distribution in the illuminated portion becomes uneven, and when the illuminating device is used for a viewing-type image display device, there is a possibility that the displayed image may have uneven brightness or color. However, in the lighting device according to the present embodiment, since the illuminance of the light emitted from the light emitting diode 11 is made uniform through the kaleidoscope 12, the illuminance distribution in the illuminated portion can be made uniform. Problems can be eliminated.

When the illumination device according to the present embodiment is used in a projection type image display device for full-color viewing, since the wavelength region of the light emitted from the light emitting diode for each color is narrow, a white light source is used. The range of colors that can be expressed by combining the emitted light of the light emitting diodes for each color without the wavelength distribution of each color depending on the wavelength distribution of the emitted light of the original white light source as in the case where the emitted light is color-separated Is widened, and as a result, good color reproduction becomes possible.

FIG. 6 is a perspective view showing a configuration of a lighting device according to a second embodiment of the present invention. The lighting device according to the present embodiment has a single kaleidoscope 1 as a light source.
This is an example in which a plurality of light emitting diodes 11 are provided so that the respective light emitting surfaces are arranged two-dimensionally with respect to the two incident end faces. In the example shown in FIG. 6, a total of nine light emitting diodes 11 arranged in three columns and three rows are arranged and joined to the incident end face of the kaleidoscope 12. The shape of each light emitting diode 11 is similar to the shape of the incident end face of the kaleidoscope 12. The overall shape of the aggregate of the nine light emitting diodes 11 is substantially the same as the shape of the light emitting diodes 11 in the lighting device shown in FIG.

In the lighting device according to the first embodiment, since one light emitting diode 11 is used as a light source,
When high luminance is required as a lighting device, it is necessary to use a light emitting diode 11 with very high luminance,
In the lighting device according to the present embodiment, since a plurality of light emitting diodes 11 are used as light sources, an equivalent lighting device is realized by using light emitting diodes 11 having lower luminance than in the first embodiment. be able to. Further, according to the lighting device according to the present embodiment, it is also possible to realize a lighting device with higher luminance than in the first embodiment. Furthermore, according to the lighting device according to the present embodiment, the shape of the light emitting surface is arbitrarily set by using a large number of light emitting diodes 11 and selectively emitting light, and the light emission intensity of each light emitting diode 11 is reduced. By changing, it is possible to obtain illumination light having an arbitrary intensity distribution. Other configurations, operations and effects in the present embodiment are described in the first section.
This is the same as the embodiment.

FIG. 7 is a perspective view showing a configuration of a lighting device according to a third embodiment of the present invention. The lighting device according to the present embodiment is configured by bundling a plurality of light emitting diodes 11 bonded to the incident end face of one kaleidoscope 12. In the example shown in FIG. 7, the kaleidoscope 1 in which the light emitting diode 11 is bonded to the incident end face is used.
2 are bundled in a total of nine rows in three columns and three rows. The shape of each light emitting diode 11 is similar to the shape of the incident end face of each kaleidoscope 12. The plurality of kaleidoscopes 12 are bundled by, for example, bonding with epoxy resin or the like. The overall shape of the lighting device according to the present embodiment is the same as that of the lighting device according to the second embodiment shown in FIG. Other configurations, operations, and effects of the present embodiment are the same as those of the second embodiment.

FIG. 8 is a perspective view showing a configuration of a lighting device according to a fourth embodiment of the present invention. The illuminating device according to the present embodiment is configured by bundling a plurality of light emitting diodes 11 joined to the incident end face of one kaleidoscope 12 in a bundle. In the example shown in FIG. 8, a kaleidoscope 12 in which a total of six light emitting diodes 11 are joined in two rows and three rows with respect to the incident end face.
Are arranged in three rows and three rows, and a total of nine pieces are bundled. The plurality of kaleidoscopes 12 are bundled by, for example, bonding with epoxy resin or the like. Other configurations, operations, and effects in the present embodiment are described in the second section.
This is the same as the embodiment.

Here, FIG. 9 shows the effect of arranging a plurality of light emitting diodes 11 in a plane as in the second to fourth embodiments and independently controlling the light emission intensity of each light emitting diode 11. This will be described with reference to FIG. FIG. 9 and FIG. 10 show the results of an experiment in which the relationship between the light emitting state of the light source and the lighting state when the light emitted from the light source is irradiated on the illuminated part through a predetermined optical system is shown. .

In FIG. 9, (a) shows a light emitting state when the light emitting surface of the light source has a rectangular shape with an aspect ratio of 3: 4 and emits light uniformly within the light emitting surface, and (b) shows a light emitting state in that case. This shows the lighting state. (C) shows a light emitting state in a case where the shape of the light emitting surface of the light source is a rectangle having an aspect ratio of 3: 4 and the light emitting intensity is distributed in the light emitting surface, and (d) shows an illumination state in that case. Is represented. Note that, in (a), the symbol A0 represents a region of uniform luminance. In (b), the code A1 has a relative luminance of 1.3.
A region with a relative value of not less than 1.4, A2 is a region with a relative value of 1.2 or more and less than 1.3, A3 is a region with a relative value of 1.1 or more and less than 1.2, and A4 is a value of a relative value Represents an area of not less than 1.0 and less than 1.1, and A5 represents an area having a relative value of 0.9 or more and less than 1.0. (B), (d)
, B1 is a region where the illuminance is a relative value of 0.9 or more and 1 or less, B2 is a region where the illuminance is a relative value of 0.8 or more and less than 0.9, B3 is an illuminance whose relative value is 0.7 or more and 0. An area of less than 8, B4 represents an area in which the illuminance is a relative value of 0.3 or more and less than 0.7, and B5 represents an area of an illuminance in a relative value of 0.1 or more and less than 0.3. In the example shown in FIG. 9C, the distribution of the light emission intensity differs between the right half and the left half in the light emission surface. That is, in the left half, the brightness is gradually increased toward the periphery, in the right half, the brightness is sharply increased in the periphery, and the maximum value of the brightness in the right half is larger than the maximum value of the brightness in the left half. I have.

Similarly, in FIG. 10, (a) shows a light emitting state when the light emitting surface of the light source is a rectangle having an aspect ratio of 9:16 and light is uniformly emitted within the light emitting surface, and (b) shows a light emitting state. This shows the lighting state in that case. Also, (c) shows the light emitting state when the shape of the light emitting surface of the light source is a rectangle having an aspect ratio of 9:16 and the light emission intensity is distributed in the light emitting surface, and (d) shows the lighting state in that case. Is represented.
In these figures, the meanings of the symbols A0 to A5 and B1 to B5 are the same as those in FIG. In the example shown in FIG. 10C, the distribution of the light emission intensity differs between the right half and the left half in the light emitting surface. That is, in the left half, the brightness is gradually increased toward the periphery, in the right half, the brightness is sharply increased in the periphery, and the maximum value of the brightness in the right half is larger than the maximum value of the brightness in the left half. I have.

FIGS. 9A and 9B and FIGS.
As can be seen from (b), when the light source emits light uniformly within the light emitting surface, the peripheral portion of the illuminated portion is darker than the central portion. Therefore, FIG. 9 (c) and FIG.
As shown in FIG. 9C, by giving the light emission intensity of the light source a distribution, as shown in FIG. 9D and FIG. 10D, it is possible to reduce uneven brightness in the illuminated portion. It becomes possible.

Since the relationship between the light emitting state of the light source and the lighting state of the illuminated part differs depending on the optical system between the light source and the illuminated part, the light emitting state of the light source is determined in the second to fourth embodiments. It is preferable to set appropriately according to the individual device in which the lighting device according to the above is used. Here, referring to FIG. 11, the lighting devices according to the second to fourth embodiments are
Consider a case where the present invention is used for a projection type video display device for viewing. In FIG. 11, (a) and (c) show the light emitting state of the light source, and (b) and (d) show the image display light valve when the light emitting state is (a) and (c), respectively. 5 shows an example of an illuminance distribution in one horizontal line in a vertical center portion. In the example shown in FIG. 11, as shown in FIG.
When a light source is configured by arranging a total of 60 rows and 10 rows, and each light emitting diode 11 emits light uniformly, the illuminance distribution on the image display light valve is as shown in FIG. It is assumed that the illuminance is large at the central portion and the illuminance gradually decreases toward the periphery. In such a case,
As shown in (c), by gradually increasing the light emission intensity of the light emitting diode 11 from the center to the periphery,
Ideally, a flat illuminance distribution can be obtained as shown in FIG.

FIG. 12 is a perspective view showing a configuration of a lighting device according to a fifth embodiment of the present invention. The lighting device according to the present embodiment has a structure in which a plurality of red light emitting diodes 11R, green light emitting diodes 11G, and blue light emitting diodes 11B are arranged and joined to the incident end face of one kaleidoscope 12. is there. As a method of arranging the light emitting diodes 11R, 11G, and 11B, there are a mosaic arrangement as shown in FIG. 13 and a Δ arrangement as shown in FIG.

In the lighting device according to the present embodiment, by illuminating the light emitting diodes 11R, 11G, and 11B simultaneously, white illumination light with uniform illuminance can be obtained. Further, in the lighting device according to the present embodiment, the light emitting diodes 11R, 11G, and 11B are sequentially turned on, so that the illuminance is uniformed and the three primary colors of R, G, and B are sequentially output. Can be obtained. Then, by using the illumination light of the three primary colors of R, G, and B, a color image can be displayed by a time-division color display method as described later. Other configurations, operations, and effects of the present embodiment are the same as those of the second embodiment.

FIG. 15 is an explanatory diagram showing the configuration of the video display device according to the sixth embodiment of the present invention. This image display device has a cubic combining prism 20, a green image display light valve 21G arranged to face one surface 20G of the combining prism 20, and a surface 20G of the combining prism 20 orthogonal to the combining prism 20. Red image display light valve 21R arranged to face other surface 20R
And a blue image display light valve 21B disposed so as to face another surface 20B of the combining prism 20 that is parallel to the surface 20R. Each of the image display light valves 21R, 21G, 21B corresponds to a spatial modulation unit in the present invention.

The image display device is further disposed on the side of each of the image display light valves 21R, 21G, 21B, and each of the image display light valves 21R, 21G, 21B has a red illumination light, a green illumination light, and a blue illumination. A red illumination device 22R, a green illumination device 22G, and a blue illumination device 22B for irradiating light are provided. The red illuminator 22R includes a red light emitting diode 11 on the incident end face of the kaleidoscope 12R.
R is joined. Similarly, the green lighting device 22G
Is a device in which a green light emitting diode 11G is joined to an incident end face of a kaleidoscope 12G.
B shows a blue light emitting diode 11B joined to the incident end face of the kaleidoscope 12B. In addition, each of the lighting devices 22R, 22G, and 22B may be of any of the first to fourth embodiments.

A red relay lens 23R and a red field lens 24R are arranged between the red illumination device 22R and the red image display light valve 21R in order from the red illumination device 22R side. Similarly, the green lighting device 22
Between G and the green image display light valve 21G, a green relay lens 23G and a green field lens 24G are arranged in this order from the green lighting device 22G side. Further, the blue illumination device 22B and the blue image display light valve 2
Between 1B, a blue relay lens 23B and a blue field lens 24B are arranged in order from the blue illumination device 22B side. The image display device is further disposed so as to face a surface 20A parallel to the surface 20G of the combining prism 20, and the image display light valves 21R, 21G,
21B for projecting the light of the image synthesized by the synthesizing prism 20 onto a screen 26 of a transmission type (in the case of a rear projection type video display device) or a reflection type (in the case of a front projection type video display device). A projection lens 25 is provided. Each of the above components of the video display device is held by a suitable holder and installed in a housing (not shown).

The combining prism 20 has a reflecting surface 20r for reflecting only the red light incident from the surface 20R toward the surface 20A,
A dichroic prism having a reflection surface 20b that reflects only the blue light incident from the surface 20B to the surface 20A side.

Image display light valves 21R, 21G, 2
1B has a large number of pixels each capable of controlling the light transmittance. Video display light valves 21R, 21G, 2
As 1B, for example, TN (Twisted Nema) is used as a liquid crystal.
A transmission type liquid crystal light valve using a tic (twisted nematic) type liquid crystal and a TFT (Thin Film Transistor) as a switching element is used.

The relay lenses 23R, 23G, 23B
Each Kaleidoscope 12R, 12G, 12B
A two-dimensional image of the emission end face of
This is a lens for forming an image on each image display light valve 21R, 21G, 21B, and a field lens 24R,
24G and 24B are relay lenses 23R and 2R, respectively.
3G, 23B is a lens for forming an image of the rear focal plane on the position of the entrance pupil of the projection lens 25. As the projection lens 25, for example, a lens close to a telecentric system is used.

The light emitting surfaces of the light emitting diodes 11R, 11G, 11B and the kaleidoscopes 12R, 12G, 12B
The cross-sectional shape of the image display light valves 21R, 21R
It is preferable to make the shape similar to the shape of the image display area of G, 21B.

FIG. 16 is a block diagram showing a circuit configuration of the video display device according to the present embodiment. As shown in this figure, the video display device according to the present embodiment receives a video signal VS, and inputs a red image signal, a green image signal, and a blue image signal corresponding to a red image, a green image, and a blue image, respectively. A video signal processing circuit 31 for generating an image signal, and a red image memory 32R for temporarily recording the red, green, and blue image signals generated by the video signal processing circuit 31; Green image memory 32G, blue image memory 3
2B, the video signal processing circuit 31 and the red image memory 3
2R, which is connected to the red light valve driving circuit 33R for driving the red video display light valve 21R, and which is connected to the video signal processing circuit 31 and the green image memory 32G, for driving the green video display light valve 21G. Blue light valve driving circuit 33B that is connected to the video light processing circuit 33G, the video signal processing circuit 31, and the blue image memory 32B and drives the blue video display light valve 21B.
And

The image display apparatus further includes a red light emitting diode driving circuit 34 for driving the red light emitting diode 11R, the green light emitting diode 11G, and the blue light emitting diode 11B (the light emitting diodes are referred to as LEDs in the figure).
R, a green light emitting diode driving circuit 34G, a blue light emitting diode driving circuit 34B, and a controller 35 for controlling the video signal processing circuit 31 and each of the light emitting diode driving circuits 34R, 34G, 34B. The controller 35 is constituted by, for example, a microcomputer.

Each light emitting diode drive circuit 34R, 34
G, 34B, each light emitting diode 1 by a variable resistor
Means are provided for independently adjusting the brightness of the light emitted from each of the light emitting diodes 11R, 11G, 11B, for example, by changing the drive current of 1R, 11G, 11B.

Next, the operation of the video display device according to this embodiment will be described. As shown in FIG. 2, the video signal VS is input to a video signal processing circuit 31, and the video signal processing circuit 31 generates a red image signal, a green image signal, and a blue image signal. Red image memory 32R, green image memory 32G, blue image memory 32
B is recorded once. Each light valve drive circuit 33R,
33G and 33B respectively read out the image signals for each color from the image memories 32R, 32G and 32B at a fixed period, and drive the video display light valves 21R, 21G and 21B based on the image signals.

On the other hand, each LED driving circuit 34R,
34G and 34B are light emitting diodes 11R, 11G,
11B so that each light emitting diode 11B is always lit.
R, 11G and 11B are driven.

As shown in FIG. 15, the red illumination light emitted from the red light emitting diode 11R and made uniform by the kaleidoscope 12R passes through a relay lens 23R and a field lens 24R, and then passes through a red image display light valve 21R. Irradiates the image display light valve for red 21R
The intensity of the light is spatially modulated by the light, and the light enters the combining prism 20. Similarly, the green illumination light emitted from the green light emitting diode 11G and made uniform by the kaleidoscope 12G is transmitted through the relay lens 23G and the field lens 24G.
After passing through G, the light is emitted to the green image display light valve 21G, spatially modulated in intensity by the green image display light valve 21G, and is incident on the combining prism 20. The blue illumination light emitted from the blue light emitting diode 11B and made uniform by the kaleidoscope 12B is applied to the blue image display light valve 21B via the relay lens 23B and the field lens 24B. The intensity is spatially modulated by the valve 21 </ b> B and is incident on the combining prism 20.

Each image display light valve 21R, 21G,
The light of each color modulated by 21B is applied to the combining prism 2
0, the light is emitted from the surface 20A, is enlarged and projected on the screen 26 by the projection lens 25, and a color image is displayed on the screen 26.

FIG. 17 shows the Kaleidoscope 12 (12
R, 12G, and 12B. ), Relay lens 23
It is explanatory drawing showing the state of the light in the kaleidoscope illumination system containing (representing 23R, 23G, 23B.) And the field lens 24 (representing 24R, 24G, 24B.). As shown in this figure, the image of the exit end face of the kaleidoscope 12 is
As a result, the image display light valve 21 which is the portion to be illuminated
(Representing 21R, 21G, and 21B).
As a result, the illumination light with uniform illuminance is irradiated onto the image display light valve 21. The field lens 24 forms an image on the rear focal plane of the relay lens 23 at the position 28 of the entrance pupil of the projection lens 25.

As described above, the light emitting diode is used as the light source in the image display device according to the present embodiment, so that the life of the light source is prolonged, and the trouble of replacing the light source can be reduced. Also, the light emitting diode 11 for each color
Since the wavelength regions of the emitted lights of R, 11G, and 11B are narrow, the wavelength distribution of each color may depend on the wavelength distribution of the emitted light of the original white light source as in the case where the emitted light of the white light source is color-separated. Without each light emitting diode 11R, 11G, 11B
The range of colors that can be expressed by the synthesis of the outgoing light is widened, resulting in good color reproduction.

The light emitting diode consumes less power and is smaller than a white light source. Further, by using a light emitting diode as a light source, light discarded when color separation is performed as in the case of using a white light source as a light source is eliminated, and light use efficiency can be improved. As a result, power consumption can be reduced and the size of the image display device can be reduced as compared with the case where a white light source is used as the light source.

Further, according to the video display device of the present embodiment, the light emitted from the light emitting diode 11 is made uniform through the kaleidoscope 12 so as to make the illuminance uniform. Video display light valve 2
1, the display brightness can be made uniform, and the display quality can be improved.

In the image display device according to the present embodiment, the light emitting surface of the light emitting diode 11 and the cross-sectional shape of the kaleidoscope 12 are changed by changing the shape of the image display light valve 21.
By making the shape similar to the shape of the image display region, the cross-sectional shape of the light beam irradiated to the image forming region can be made to have a shape corresponding to the shape of the image forming region, and the light beam has a circular cross section. As compared with the case where a light source is used, the light use efficiency is improved, and as a result, the power consumption and the size of the device can be further reduced.

According to the video display device of the present embodiment, the light emitting diodes 11R, 11G, 11
Since the brightness of the light emitted from B can be adjusted independently, the color adjustment range is wider than in the past. If the efficiencies of the light emitting diodes 11R, 11G, and 11B are different for each color, the light emitting diodes 1R are previously set in the light emitting diode driving circuits 34R, 34G, and 34B.
It is possible to adjust the brightness of the light emitted from each of the light emitting diodes 11R, 11G, 11B independently by changing the drive current of the 1R, 11G, 11B, etc., and to adjust the color temperature of the white screen to a predetermined value. Becomes Also, the viewer
Arbitrarily, it is also possible to adjust the brightness of the light emitted from each of the light emitting diodes 11R, 11G, and 11B to perform color adjustment that matches the taste of the viewer. In the video display device according to the present embodiment, each of the light emitting diodes 11R, 11R
Since the brightness of the light emitted from G and 11B can be adjusted independently, the light emitting diodes 11R, 11G and 1 for each color can be adjusted.
The brightness of each color can be adjusted while keeping the light emitting area of 1B the same, and as a result, the optical system of the video display device can be simplified.

Next, a video display apparatus according to a seventh embodiment of the present invention will be described with reference to FIGS. FIG. 18 is an explanatory diagram illustrating the configuration of the video display device according to the present embodiment. The video display device according to the present embodiment is an example in which a color image is displayed by a time-division color display method. The image display device according to the present embodiment does not include the image display light valves 21R, 21G, and 21B for each color in the sixth embodiment. An image display light valve 41 is provided.

FIG. 19 is a block diagram showing a circuit configuration of the video display device according to the present embodiment. The video display device according to the present embodiment receives a video signal VS and generates a red image signal, a green image signal, and a blue image signal corresponding to a red image, a green image, and a blue image, respectively. A video signal processing circuit 42 for sequentially switching and outputting, a red image signal generated by the video signal processing circuit 42,
An image memory 43 for temporarily recording a green image signal and a blue image signal, and a light valve driving circuit 44 connected to the video signal processing circuit 42 and the image memory 43 and driving the video display light valve 41 are provided. Have.

The image display apparatus further includes a red light emitting diode driving circuit 34 for driving the red light emitting diode 11R, the green light emitting diode 11G, and the blue light emitting diode 11B (the light emitting diodes are referred to as LEDs in the figure).
R, a green light emitting diode driving circuit 34G, a blue light emitting diode driving circuit 34B, a video signal processing circuit 42, a light valve driving circuit 44, and a controller 35 for controlling the light emitting diode driving circuits 34R, 34G, 34B.

Next, the operation of the video display device according to the present embodiment will be described with reference to the timing chart of FIG. The controller 35 receives the video signal VS, synchronizes with the video signal, generates a timing signal for dividing a period of one frame or one field into three, and generates a timing signal processing circuit 42 and a light valve driving circuit 44.
Send to The video signal processing circuit 44 generates a red image signal, a green image signal, and a blue image signal in accordance with the timing signal, and sequentially switches and outputs these. This image signal is temporarily recorded in the image memory 43. The light valve drive circuit 44 sequentially reads out the image signals for each color from the image memory 43 according to the timing signal from the controller 35, and drives the video display light valve 41 based on the image signals. As a result, in the video display light valve 41, as shown in FIG. 20D, each gradation image for red (R), green (G), and blue (B) during one frame or one field period. Are sequentially switched and displayed.

On the other hand, the controller 35 controls the light emitting diodes 11R and 11R in synchronization with the timing at which the red, green and blue gradation images are displayed on the video display light valve 41.
The light emitting diode drive circuits 34R, 34G, 34B are controlled so that the lights 11G, 11B are sequentially turned on. As a result, as shown in FIGS. 20A to 20C, the light emitting diode 11 is synchronized with the timing at which the red, green, and blue gradation images are displayed in the video display light valve 41.
R, 11G, and 11B (in FIG. 20, each LED
Described as R, LED G, and LED B. ) Is turned on, and the light of each color is sequentially switched and irradiated to the image display light valve 41.

By such an operation, the red, green and blue images are sequentially switched and projected on the screen 26, but are recognized by the viewer as a color image due to the afterimage effect of human eyes. Other configurations, operations, and effects of the present embodiment are the same as those of the sixth embodiment.

Next, an image display apparatus according to an eighth embodiment of the present invention will be described with reference to FIGS. The video display device according to the present embodiment is an example in which a time-division color display method is used as in the seventh embodiment and a color image is displayed using a digital gradation display method.

First, the principle of the digital gradation display method will be described with reference to FIG. The principle of the digital gradation display method is that an image to be displayed as shown in FIG. 21A is converted into a plurality of weighted bit images (binary images) as shown in FIGS. It is expressed as a sum. The upper part of FIG. 21A shows an example of a gradation image to be displayed, and the upper part of FIGS.
Each bit image is weighted to 8: 4: 2: 1. The lower part of FIGS. 21 (a) to (e) shows the luminance of each pixel in the upper image in hexadecimal. In this digital gradation display method, a weighted group of bit images is displayed within the time of one frame by controlling a light source and a video display light valve for binary display, and the afterimage effect of the human eye is used. , Make the viewer feel the gradation.

There are mainly two methods for weighting bit images in digital gradation display. One is a pulse width modulation gradation display in which the brightness of the illumination light is fixed and weighted by the length of the display time of each bit image, and the other is the length of the display time of each bit image. Is constant,
This is a light intensity modulation gradation display in which weighting is performed according to the brightness of illumination light. Further, the two methods can be used in combination.

The configuration of the video display apparatus according to the present embodiment is substantially the same as that shown in FIG. 19, but the light emitting diodes 11R, 11G, and 11B may be any as long as they can perform binary display.

Next, the operation of the video display device according to the present embodiment will be described with reference to the timing chart of FIG. FIGS. 22A to 22C show the light emission timing and the light emission amount of the light emitting diode, respectively. FIG.
2 (d) shows the display state of the image display light valve 41. Here, an example will be described in which digital gradation display is performed by using both pulse width modulation gradation display and light intensity modulation gradation display. In the following description, the bit images weighted at 8: 4: 2: 1 to represent a red gradation image are referred to as images R8, R4, R2, and R1, respectively, to represent a green gradation image. For this purpose, each bit image weighted 8: 4: 2: 1 is converted into an image G8, G8, respectively.
4, G2, and G1, and the respective bit images weighted at 8: 4: 2: 1 to represent a blue gradation image are images B8, B4, B2, and B1, respectively.

The controller 35 receives the video signal VS, generates a predetermined timing signal synchronized with the video signal VS, and sends it to the video signal processing circuit 42 and the light valve driving circuit 44. The video signal processing circuit 42 performs bit image R8, G
8, B8, R4, R2, R1, G4, G2, G1, B
4, B2 and B1 are generated, and these are sequentially switched and output. This image signal is temporarily recorded in the image memory 43. The light valve drive circuit 44 controls the image memory 4 according to a timing signal from the controller 35.
The image signal of each bit image is sequentially read from 3 and the video display light valve 44 is driven based on the image signal. In the present embodiment, as shown in FIG.
Bit images R8, G8, and B8 are sequentially displayed by dividing the period of ／ from the beginning of one frame into three equal parts, and the bit images R4, R2, and R1 are divided into nine equal parts in the remaining period of one frame.
G4, G2, G1, B4, B2, and B1 are sequentially displayed. Therefore, the period during which the bit images R8, G8, and B8 are displayed is twice as long as the period during which other bit images are displayed.

Further, the controller 35 is arranged as shown in FIG.
As shown in (c), the light emitting diodes 11R, 11G, and 11 are synchronized with the timing at which the red, green, and blue bit images are displayed in the video display light valve 41.
Each light emitting diode driving circuit 3
4R, 34G and 34B are controlled. Further, the controller 35 determines that the light emitting diodes 12R, 12G, and 12B have the same light emission amount during the period in which the bit images R8, G8, and B8 are displayed and the period in which the bit images R4, G4, and B4 are displayed. If the amount is 1, the bit image R
Each light-emitting diode drive circuit 34 has a light emission amount of ２ during the period in which 2, 2, G2, and B2 are displayed, and 1/4 in the period of displaying the bit images R1, G1, and B1.
R, 34G and 34B are controlled. By such an operation, the light of a plurality of bit images weighted 8: 4: 2: 1 for each color within one frame is sequentially transmitted to the screen 26.
And is recognized by the viewer as a color image due to the afterimage effect of the human eye. Other configurations, operations, and effects of the present embodiment are the same as those of the seventh embodiment. Since the response speed of the light emitting diode is as fast as several microseconds, a color image display using the time-division color display method as in the seventh or eighth embodiment becomes possible.

FIG. 23 is an explanatory diagram showing the configuration of the video display device according to the ninth embodiment of the present invention. The video display device according to the present embodiment is an example in which a reflective liquid crystal light valve is used as a video display light valve, and a color image is displayed using a time-division color display method.
The image display device according to the present embodiment is different from the image display device shown in FIG. 18 in that a dichroic mirror section 50 is provided instead of the combining prism 20 and the field lens 24 is provided.
Instead of R, 24G and 24B, a field lens 51 is provided on the exit side of the dichroic mirror unit 50,
Instead of an image display light valve 41 using a transmission type liquid crystal light valve, a polarization beam splitter 60 and an image display light valve 61 using a reflection type liquid crystal light valve are provided.

The dichroic mirror unit 50 includes a dichroic mirror 50R that reflects only the red light from the illumination device 22R to the field lens 51, and a dichroic mirror 50B.
And a dichroic mirror 50B that reflects only blue light from the lens to the field lens 51 side at the center of each other.

The polarizing beam splitter 60 and the image display light valve 61 are arranged on the optical path of the light emitted from the field lens 51 in this order. The polarization beam splitter 60 has a reflection surface 60a that transmits P-polarized light (polarized light whose polarization direction is parallel to the incident surface) and reflects S-polarized light (polarized light whose polarization direction is perpendicular to the incident surface). I have. In the present embodiment, the projection lens 25 is configured such that the light from the image display light valve 61 is reflected by the reflection surface 60 of the polarization beam splitter 60.
It is arranged in a direction in which the light is reflected by a and travels.

As the image display light valve 61, for example, a reflection type liquid crystal light valve utilizing birefringence of liquid crystal is used. As a reflection type liquid crystal light valve, specifically, for example, a polysilicon T
FT, amorphous TFT, CMOS (complementary metal oxide semiconductor) or SRA fabricated on crystalline silicon
A reflective liquid crystal panel using a substrate in which a circuit such as M (static random access memory) is incorporated can be used. As the liquid crystal having birefringence, a nematic liquid crystal, a ferroelectric liquid crystal, or the like can be used.

In the video display apparatus according to the present embodiment, the light emitting diodes 11R, 11G, 11B and the video display light valve 61 are driven in accordance with the time division color display system, similarly to the seventh or eighth embodiment. . The light emitted from each of the light emitting diodes 11R, 11G, 11B enters the polarization beam splitter 60 via the relay lenses 23R, 23G, 23B, the dichroic mirror unit 50, and the field lens 51. Polarizing beam splitter 6
0, only the P-polarized light component of the incident light
The light passes through Oa and enters the image display light valve 61. An image display light valve 61 using a reflection type liquid crystal light valve spatially converts incident light by using birefringence to change the polarization state (degree of polarization) for each pixel according to an image to be displayed. The light is modulated and reflected to the polarization beam splitter 60 side. In the polarization beam splitter 60,
Only the S-polarized light component of the light from the image display light valve 61 is reflected by the reflection surface 60a, enters the projection lens 25, and is enlarged and projected on the transmission type or reflection type screen 26. Other configurations, operations, and effects of the present embodiment are the same as those of the seventh or eighth embodiment.

FIG. 24 is an explanatory diagram showing the configuration of the video display device according to the tenth embodiment of the present invention. The video display device according to the present embodiment is an example in which a video display light valve using a reflective liquid crystal light valve is provided for each color. This image display device includes a red illumination device 22R, a red relay lens 23R, a red field lens 24R, a red polarization beam splitter 71, and a red image display light valve 61R arranged on a straight line. In these, the S-polarized light component of the light reflected by the red image display light valve 61R reflected by the reflection surface 71a of the red polarization beam splitter 71 is converted to the surface 20R of the combining prism 20.
It is arranged so that it may be incident. The image display device further includes a green illumination device 22G, a green relay lens 23G, a green field lens 24G, a green polarization beam splitter 72, and a green image display light valve 61G arranged on a straight line. These are S-polarized light components reflected by the reflection surface 72a of the polarization beam splitter 72 for green among the light reflected by the image display light valve 61G for green,
It is arranged so as to enter the surface 20 </ b> G of the combining prism 20. The video display device further includes a blue illumination device 22B, a blue relay lens 23B, a blue field lens 24B, a blue polarization beam splitter 73, and a blue video display light valve 61B arranged on a straight line. These are the reflection surfaces 73a of the blue polarization beam splitter 73 of the light reflected by the blue image display light valve 61B.
The S-polarized light component reflected by the
It is arranged to be incident on G.

The polarization beam splitters 71, 7
2, 73 and video display light valves 61R, 61G, 61
The principle of modulation by B is as described in the ninth embodiment. The light modulated for each color is combined by the combining prism 20 in the same manner as in the first embodiment, and is projected on the screen 26 by the projection lens 25. Other configurations, operations, and effects of the present embodiment are the same as those of the sixth embodiment.

FIG. 25 is an explanatory diagram showing the configuration of the video display device according to the eleventh embodiment of the present invention. The image display device according to the present embodiment includes an illumination device 75, a relay lens 76, a field lens 77, a polarization beam splitter 60, and a video display light valve 6 which are arranged on a straight line.
1 is provided. The polarization beam splitter 60 has a reflection surface 60a that transmits P-polarized light and reflects S-polarized light. In the present embodiment, the projection lens 25 is arranged in a direction in which light from the image display light valve 61 travels while being reflected by the reflection surface 60 a of the polarization beam splitter 60.

As shown in FIGS. 12 to 14, the lighting device 75 in the present embodiment
2, the red light emitting diode 11R, the green light emitting diode 11G, and the blue light emitting diode 11B
Are arranged and joined in plural numbers.

In the video display device according to the present embodiment, the light emitting diodes 11R, 11G,
By illuminating 11B sequentially, it is possible to obtain illumination light of three primary colors of R, G, and B, which are output uniformly with uniform illuminance. Using the three primary colors of R, G, and B, a color image can be displayed by the time-division color display method in the same manner as in the ninth embodiment.
Other configurations, operations, and effects of the present embodiment are the same as those of the ninth embodiment.

FIG. 26 is an explanatory diagram showing a configuration of a video display device according to the twelfth embodiment of the present invention. The video display device according to the present embodiment is an example of a virtual image display type video display device, and has a form of a so-called head-mounted display. This image display device includes a lighting device 75, a relay lens 81, and a transmission type image display light valve 82 which are arranged on a straight line. The image display device according to the present embodiment further includes a half mirror 83 disposed on the optical path of light emitted from the image display light valve 82, and a light emitted from the image display light valve 82 and reflected by the half mirror 83. And a concave mirror 84 also serving as a half mirror disposed on the optical path of light. Each of the above-mentioned components is held in an appropriate holder and installed in a housing. As shown in FIGS. 12 to 14, the illuminating device 75 is provided with a red light emitting diode 11R, a green light emitting diode 11G, and a blue light emitting diode 11B with respect to the incident end face of the kaleidoscope 12, as shown in FIGS. Are arranged and joined in plural numbers.

In the video display device according to the present embodiment, each of the light emitting diodes 11R, 11G,
By illuminating 11B sequentially, it is possible to obtain illumination light of three primary colors of R, G, and B, which are output uniformly with uniform illuminance. The three primary colors of illumination light are sequentially spatially modulated by the image display light valve 82. The modulated light is partially reflected by the half mirror 83 and is incident on the concave mirror 84, where it is partially reflected and is incident on the half mirror 83, and further is partially reflected on the half mirror 83.
And projected on the eyes 85 of the observer. Thus, the observer observes the virtual image 86 generated and enlarged by the image display light valve 82 together with the front scene.

An image display device having the form of a head-mounted display requires an illumination device that is small and can provide uniform illumination light. In the video display device according to the present embodiment, as such a lighting device, a lighting device 75 having light emitting diodes 11R, 11G, 11B and kaleidoscope 12 is used. Therefore,
The size of the image display device can be reduced, and the quality of the image can be improved by uniform illumination light. Other configurations, operations, and effects of the present embodiment are the same as those of the eleventh embodiment.

FIG. 27 is an explanatory diagram showing a configuration of a video display device according to the thirteenth embodiment of the present invention. The present embodiment is an example in which the present invention is applied to an exposure apparatus for projecting and exposing a mask pattern (corresponding to an image in the present invention) on a photoresist on a semiconductor wafer. The exposure apparatus according to this embodiment includes an illumination device 91,
A condenser lens 92 that collects the light emitted from the illumination device 91 and irradiates the light onto a mask 93 (corresponding to a spatial modulation unit in the present invention) on which a predetermined pattern is formed, A projection lens 94 for projecting the photoresist on the semiconductor wafer 95; The lighting device 91 has the light emitting diode 11 bonded to the incident end face of the kaleidoscope 12, and may be any of the first to fourth embodiments. In the present embodiment, the light emitting diode 11 emits light (visible light or ultraviolet light) that is sensitive to the photoresist.

In this exposure apparatus, the light emitted from the illumination device 91 passes through the condenser lens 92 and passes through the mask 93
Is irradiated. The light spatially modulated by the mask 93 is projected on a photoresist on a semiconductor wafer 95 by a projection lens 94, and the photoresist is exposed. Note that the exposure apparatus according to the present embodiment may be an exposure apparatus that performs equal-size exposure or a step-type projection exposure apparatus that performs reduced projection exposure.

According to the exposure apparatus of the present embodiment, since the illumination device 91 in which the light emitting diode 11 is joined to the incident end face of the kaleidoscope 12 is used as the light source, the life of the light source is extended, and Can improve usage efficiency,
Power consumption can be reduced and the size of the exposure apparatus can be reduced. Further, it is possible to irradiate the mask 93 with illumination light having uniform illuminance, and it is possible to improve exposure accuracy.

The present invention is not limited to the above embodiments. For example, in the sixth to twelfth embodiments, a fly-eye lens is used instead of the kaleidoscope as the illuminance uniforming optical element. You may. The fly-eye lens is an array of lenses in which small lenses are arranged (refer to the above-mentioned document “Optical Technology Contact”, Vol. 3).
3, No. 2, 1995, pp. 41-44. " ).

FIG. 28 is a side view showing an example of a lighting device in which a plurality of light emitting diodes are arranged on the incident end face of the fly-eye lens, and FIG. 29 is a sectional view of the fly-eye lens in FIG. As shown in these drawings, the fly-eye lens 100 is configured by arranging a number of small lenses 101. In the example shown in FIG.
A plurality of light emitting diodes 11 are arranged on the zero incident end face. On the surface opposite to the light emitting surface of each light emitting diode 11, a reflecting mirror 111 having a shape that forms a part of a spherical surface is provided. In addition, each light emitting diode 11
A lens 112 is provided in front of each of the light emitting surfaces. The plurality of light emitting diodes 11 and the reflecting mirror 1
The lens 11 and the lens 112 are arranged such that the light emitting surface of the light emitting diode 11 faces the incident end face of the fly-eye lens 100. The lighting device as shown in FIG.
It is possible to replace the lighting device according to the sixth to thirteenth embodiments.

The spatial modulation means is not limited to the one described in the embodiment, but may be a liquid crystal light valve using a ferroelectric liquid crystal or a polymer dispersed liquid crystal. The light may be spatially modulated by controlling the reflection, transmission, diffraction, etc. of the light by a simple operation.

In the sixth to twelfth embodiments, the light emitting diodes emitting red light, green light and blue light are used. However, the light emitting diodes emitting light of other colors may be used. good. In this case, the image display light valve is driven based on a color signal corresponding to the color of the light emitted from the light emitting diode.

[0095]

As described above, according to the illuminating device according to any one of the first to fifth aspects, light emitted from a light source using one or more light emitting diodes is emitted by an illuminance uniforming optical element. Since the illuminance in the illuminated part is made uniform and the illuminated part is illuminated, the life of the light source is prolonged, the power consumption can be reduced, and the device can be downsized. This has the effect of making the distribution uniform.

According to the lighting device of the fourth aspect,
A plurality of light emitting diodes are provided so that the respective light emitting surfaces are arranged in a plane, and the respective light emission intensities are independently controlled. Providing the distribution of the light emission intensity has an effect that more uniform illumination light can be obtained.

According to the image display device of the present invention, the light emitted from the light source using one or more light emitting diodes is converted into an illuminance in the spatial modulation means by the illuminance uniforming optical element. So that it is uniform
By irradiating to the spatial modulation means, spatially modulated by the spatial modulation means according to the information of the image to be displayed, and projected by the projection optical system, the life of the light source becomes longer,
It is possible to reduce the power consumption and the size of the device, and furthermore, it is possible to achieve good color reproduction and uniform display luminance.

According to the image display device of the ninth aspect, a plurality of light emitting diodes are provided so that each light emitting surface is arranged in a plane, and each light emitting diode is controlled independently. Therefore, in addition to the effect of the video display device according to the sixth aspect, there is an effect that more uniform illumination light can be obtained and display luminance can be made more uniform.

According to the image display device of the present invention, the light source includes a plurality of light emitting diodes for emitting light in different wavelength ranges to form a color image. A plurality of light emitting diodes are driven so that light in different wavelength regions is sequentially emitted in a cycle, so that a color image by a time-division color display method is provided in addition to the effect of the video display device according to claim 6. Can be displayed.

According to the image display device of the twelfth aspect, the end surface on the emission side of the rod-type optical integrator as the illuminance uniforming optical element is formed in a shape corresponding to the image forming area in the spatial light modulator. Therefore, in addition to the effect of the video display device according to claim 6, there is an effect that the light use efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a lighting device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a modification of the lighting device shown in FIG.

FIG. 3 is a cross-sectional view illustrating an example of a joint portion between the light emitting diode and the kaleidoscope in the lighting device according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing another example of a joint portion between the light emitting diode and the kaleidoscope in the lighting device according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram for describing a principle of uniformity of illuminance in a kaleidoscope.

FIG. 6 is a perspective view illustrating a configuration of a lighting device according to a second embodiment of the present invention.

FIG. 7 is a perspective view illustrating a configuration of a lighting device according to a third embodiment of the present invention.

FIG. 8 is a perspective view illustrating a configuration of a lighting device according to a fourth embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a result of an experiment for examining a relationship between a light emitting state of a light source and an illumination state of an illuminated part.

FIG. 10 is an explanatory diagram showing a result of an experiment for examining a relationship between a light emitting state of a light source and an illumination state of an illuminated part.

FIG. 11 is an explanatory diagram showing an example of a light emitting state of a light source and an illuminance distribution in a video display light valve.

FIG. 12 is a perspective view showing a configuration of a lighting device according to a fifth embodiment of the present invention.

FIG. 13 is an explanatory diagram showing an example of a method of arranging the light emitting diodes in FIG.

FIG. 14 is an explanatory view showing another example of the method of arranging the light emitting diodes in FIG.

FIG. 15 is an explanatory diagram showing a configuration of a video display device according to a sixth embodiment of the present invention.

FIG. 16 is a block diagram illustrating a circuit configuration of a video display device according to a sixth embodiment of the present invention.

FIG. 17 is an explanatory diagram illustrating a state of light in a kaleidoscope illumination system of a video display device according to a sixth embodiment of the present invention.

FIG. 18 is an explanatory diagram illustrating a configuration of a video display device according to a seventh embodiment of the present invention.

FIG. 19 is a block diagram illustrating a circuit configuration of a video display device according to a seventh embodiment of the present invention.

FIG. 20 is an explanatory diagram showing an operation of the video display device according to the seventh embodiment of the present invention.

FIG. 21 is an explanatory diagram for describing the principle of a digital gradation display method used in a video display device according to an eighth embodiment of the present invention.

FIG. 22 is an explanatory diagram showing an operation of the video display device according to the eighth embodiment of the present invention.

FIG. 23 is an explanatory diagram showing a configuration of a video display device according to a ninth embodiment of the present invention.

FIG. 24 is an explanatory diagram showing a configuration of a video display device according to a tenth embodiment of the present invention.

FIG. 25 is an explanatory diagram showing a configuration of a video display device according to an eleventh embodiment of the present invention.

FIG. 26 is an explanatory diagram showing a configuration of a video display device according to a twelfth embodiment of the present invention.

FIG. 27 is an explanatory diagram showing a configuration of a video display device according to a thirteenth embodiment of the present invention.

FIG. 28 is a side view showing an example of a lighting device which can be replaced with the lighting devices according to the sixth to thirteenth embodiments of the present invention.

FIG. 29 is a sectional view of the fly-eye lens in FIG. 28;

[Explanation of symbols]

11, 11R, 11G, 11B ... light emitting diode, 1
2,12R, 12G, 12B ... Kaleidoscope, 20
... Synthetic prism, 21R, 21G, 21B ... Video display light valve, 23R, 23G, 23B ... Relay lens,
24R, 24G, 24B ... field lens, 25 ... projection lens.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 33/00 H01L 33/00 N H04N 5/74 H04N 5/74 K A

Claims (12)

[Claims] 1. A light source using one or more light-emitting diodes for emitting light to be illuminated on an illuminated portion, and an illuminance for equalizing the illuminance of the light emitted from the light source in the illuminated portion. A lighting device, comprising: a shaping optical element. 2. The illuminance uniforming optical element is one or more rod-type optical integrators, and the light-emitting diode has a rod-type such that a light-emitting surface thereof faces one end surface of the rod-type optical integrator. The lighting device according to claim 1, wherein the lighting device is joined to one end surface of the light integrator. 3. The illuminance uniforming optical element is a fly-eye lens, and the light-emitting diode is arranged such that a light-emitting surface thereof faces one end surface of the fly-eye lens. The lighting device according to claim 1. 4. The lighting device according to claim 1, wherein a plurality of the light emitting diodes are provided so that respective light emitting surfaces are arranged in a plane, and each light emitting intensity is independently controlled. apparatus. 5. The lighting device according to claim 1, wherein the light source includes a plurality of light emitting diodes that emit light in different wavelength ranges to form a color image. 6. A spatial modulation means for spatially modulating light to be irradiated in accordance with information of an image to be displayed to form an image, and at least one light emitting means for emitting light to the spatial modulation means. A light source using a light emitting diode; an illuminance uniforming optical element for equalizing the illuminance of the light emitted from the light source in the spatial modulation means; and a projection for projecting the light modulated by the spatial modulation means An image display device comprising an optical system. 7. The illuminance uniforming optical element is one or more rod-type optical integrators, and the light-emitting diode has a rod-type optical integrator such that a light-emitting surface faces one end surface of the rod-type optical integrator. The image display device according to claim 6, wherein the image display device is joined to one end surface of the optical integrator. 8. The illuminance uniforming optical element is a fly-eye lens, and the light-emitting diode is disposed so that a light-emitting surface thereof faces one end surface of the fly-eye lens. The video display device according to claim 6. 9. The image according to claim 6, wherein a plurality of the light emitting diodes are provided so that respective light emitting surfaces are arranged in a plane, and each light emitting intensity is independently controlled. Display device. 10. The image display device according to claim 6, wherein the light source includes a plurality of light emitting diodes that emit light in different wavelength ranges to form a color image. 11. The image display device according to claim 10, further comprising a driving unit for driving the plurality of light emitting diodes so that light in different wavelength ranges is sequentially emitted at a predetermined cycle. . 12. The illuminance equalizing optical element is one or more rod-type optical integrators, and an end surface on the emission side of the rod-type optical integrator is formed in a shape corresponding to an image forming area in the spatial light modulator. The video display device according to claim 6, wherein