JP2007041567A - Illuminating apparatus and image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfactorily maintain the high luminance of illuminating light and maintain the good white balance of a displayed image, regarding an illuminating apparatus used for an image display apparatus, and also, to prolong the life of a light source, especially, even in the case of using a solid-state light emitter as the light source, and also, to prevent a signal processing for the image display apparatus from becoming difficult. <P>SOLUTION: The illuminating apparatus includes a plurality of light sources 2G<SB>1</SB>and 2G<SB>2</SB>for emitting light of the same wavelength, a control means 4 for controlling respective light sources 2G<SB>1</SB>and 2G<SB>2</SB>to turn on, and an optical path converting means 10 for converting at least one of the optical paths of light emitted from respective light sources 2G<SB>1</SB>and 2G<SB>2</SB>and guiding the light emitted from respective light sources 2G<SB>1</SB>and 2G<SB>2</SB>to the same spatial light modulating element 1G. The control means 4 controls respective light sources 2G<SB>1</SB>and 2G<SB>2</SB>to turn on in time-division. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illumination device for illuminating a spatial light modulation element in an image display device or the like, and an image display device configured to include such an illumination device.

  2. Description of the Related Art Conventionally, there has been proposed an image display device that includes a plurality of spatial light modulation elements, illuminates these spatial light modulation elements with an illumination device, and forms an image of modulated light that has passed through each spatial light modulation element to display an image.

  Each spatial light modulator displays a red component, a green component, and a blue component of a display image, respectively, and modulates illumination light according to these images. The illumination device illuminates a spatial light modulation element displaying a red component image with red illumination light, illuminates a spatial light modulation element displaying a green component image with green illumination light, and displays a blue component image. The spatial light modulator to be illuminated is illuminated with blue illumination light.

  The modulated light modulated by each spatial light modulator is color-synthesized and imaged, and displays an image on a screen, for example.

  As an illumination device of such an image display device, as described in Patent Document 1, a light source using a solid light emitting element that emits red light, green light, and blue light has been proposed. A solid light emitting element is a light emitting diode (LED), a semiconductor laser diode (LD), an electroluminescent element (EL), or the like.

  In the image display device having this illumination device, as shown in FIG. 12, each of the solid-state light emitting elements 101r, 101g, and 101b for red, green, and blue is provided by independent drive circuits 102r, 102g, and 102b. Light is controlled. These drive circuits 102r, 102g, and 102b are controlled by the controller 103.

  The illumination light emitted from the red solid-state light emitting element 101r is incident on the red transmissive spatial light modulation element 107r via the relay lens 104r, the field lens 105r, and the polarizer 106r. The red illumination light is polarization-modulated by the transmissive spatial light modulation element 107r in accordance with the image signal of the red component, passes through the analyzer 108r, and enters the color synthesis prism 109 as red image light.

  The illumination light emitted from the green solid light emitting element 101g is incident on the green transmissive spatial light modulator 107g via the relay lens 104g, the field lens 105g, and the polarizer 106g. The green illumination light is polarized and modulated in accordance with the image signal of the green component by the transmissive spatial light modulation element 107g, passes through the analyzer 108g, and enters the color synthesis prism 109 as green image light.

  The illumination light emitted from the blue solid-state light emitting element 101b is incident on the blue transmissive spatial light modulation element 107b via the relay lens 104b, the field lens 105b, and the polarizer 106b. The blue illumination light is polarization-modulated by the transmissive spatial light modulator 107b in accordance with the image signal of the blue component, and enters the color synthesis prism 109 as blue image light through the analyzer 108b.

  The red, green and blue image lights incident on the color combining prism 109 are color combined and incident on the projection lens 110. The projection lens 110 projects image light of each color on a screen (not shown), enlarges it, forms an image, and displays an image.

  In such an image display device, as shown in FIG. 13, a color image can be displayed by continuously driving the red, green, and blue solid light emitting elements 101r, 101g, and 101b. Further, as described in Patent Document 1, in this image display device, as shown in FIG. 14, human solid-state light emitting devices 101 r, 101 g, 101 b can also be sequentially driven in a time-division manner. A color image can be displayed by utilizing the afterimage effect in vision.

  Patent Document 2 describes an image display device having an illumination device using solid-state light emitting elements that emit four different colors. According to Patent Document 2, in this image display device, an image is formed by four colors, so that the white balance of the display image is improved. In addition, two solid light emitting elements having similar colors among the four color solid light emitting elements are sequentially driven in a time-division manner to avoid the influence of the luminance difference between these solid light emitting elements.

JP 10-32080 A JP 2004-325477 A

  By the way, the lifetime of the solid-state light-emitting element used in the illumination device as described above depends on the temperature (junction temperature) of the light-emitting layer. In general, when the junction temperature exceeds 100 ° C., the lifetime of the solid state light emitting device is remarkably shortened. For this reason, in a solid state light emitting device, it is not possible to input high power that would cause the junction temperature to exceed 100 ° C., and since the light emission efficiency is low, the display image has sufficient luminance. It has become difficult.

  In the image display device described in Patent Document 1, the red, green, and blue solid-state light emitting elements 101r, 101g, and 101b emit light sequentially in a time-sharing manner. Although it seems that the rise in temperature is suppressed and the life is extended, the light emission period of each color solid-state light emitting element 101r, 101g, 101b per field is shortened, so that the brightness of the display image cannot be increased.

  Further, since the light emission efficiency of the green solid light emitting element 101g is lower than that of the red and blue solid light emitting elements 101r and 101b, it is difficult to optimize the white balance while maintaining the luminance of the display image. . That is, in order to maintain the white balance of the display image, the light emission power of the red and blue solid light emitting elements 101r and 101b must be lowered, and the luminance of the entire display image is lowered.

  In the image display device described in Patent Document 2, since the spatial light modulation element is illuminated using solid-state light emitting elements that emit four different colors, the image displayed by the spatial light modulation element is 4 You must prepare one corresponding to one color component. However, generally used image signals are composed of three color components of red (R), green (G), and blue (B), and correspond to the fourth color component based on this image signal. Image signals to be generated must be generated, and complicated signal processing must be performed.

  In addition, in this Patent Document 2, the idea of optimizing the light emission period of each solid state light emitting device to suppress the increase in junction temperature is disclosed for time-division driving of two solid state light emitting devices having similar colors. Therefore, the effect of extending the lifetime of the solid state light emitting device is not assumed.

  Therefore, the present invention has been proposed in view of the above circumstances, and in an illumination device used for illuminating a spatial light modulation element in an image display device or the like, the brightness of illumination light is maintained sufficiently high. In addition, it is possible to maintain a sufficiently long lifetime of the light source, particularly when a solid light emitting element is used as the light source, while maintaining the white balance of the display image satisfactorily. It is another object of the present invention to provide an illuminating device that does not make signal processing in the image display device difficult, and to provide an image display device using such an illuminating device.

  In order to solve the above-described problems and achieve the object, an illumination device according to the present invention has any one of the following configurations.

[Configuration 1]
A plurality of light sources that emit light of the same wavelength, a control unit that controls lighting of each light source, and at least one of the light from each light source is converted into an optical path so that the light from each light source is converted into the same spatial light modulator. And a light path changing means for guiding, and the control means controls each light source to light up in a time division manner.

[Configuration 2]
In the illuminating device having the configuration 1, the optical path conversion means includes a reflection plate that reflects light from the light source, and moves the reflection plate with respect to the optical path of the light from the light source in synchronization with the lighting cycle of the light source. Thus, the optical path of the light from the light source is converted in a time division manner.

[Configuration 3]
The lighting device having the configuration 1 or the configuration 2 includes a temperature detection unit that detects an environmental temperature, and the control unit controls the lighting frequency of each light source based on the environmental temperature detected by the temperature detection unit. The light emitting part temperature of each light source is suppressed to a predetermined temperature or lower.

  The image display apparatus according to the present invention has the following configuration.

[Configuration 4]
Combining a plurality of spatial light modulation elements, an illumination device provided corresponding to each spatial light modulation element and illuminating the corresponding spatial light modulation element, and modulated light emitted from the illumination device and passing through each spatial light modulation element And at least one of the illuminating devices is an illuminating device having any one of Configurations 1 to 3.

  In the illumination device according to the present invention, control is performed so that a plurality of light sources that emit light of the same wavelength are lit in a time-division manner.

  In other words, in this lighting device, since the light source is driven with a pause period, even if this light source is a solid-state light emitting device, it is possible to suppress an increase in junction temperature and to apply higher power than in continuous driving. And the brightness of the illumination light can be improved. In order to obtain the effect of suppressing such an increase in junction temperature, it is more preferable to light each light source with the same lighting cycle and lighting time.

  Moreover, if the ambient temperature is detected and the lighting frequency of each light source is controlled based on the ambient temperature by the control means, the light emitting part temperature of each light source can be suppressed to a predetermined temperature or lower.

  Therefore, in this illuminating device, it is possible to improve the luminance of illumination light while suppressing an increase in the junction temperature even for a solid-state light emitting element for green having low luminous efficiency. Since the brightness of the illumination light from the green solid-state light emitting element can be improved, the white balance of the display image in the image display device is good without reducing the brightness of the illumination light of other colors (red and blue) Can be maintained. In this illumination device, if each light source is controlled so that at least one of the light sources is always lit, the light emission period continues and the maximum luminance of the illumination light can be maintained.

  And in this illuminating device, when power equivalent to that in the case of continuously driving the light source is turned on, excessive heat generation can be suppressed, the life of the light source can be extended, and overall Power consumption can be reduced.

  Further, in this illumination device, since the plurality of light sources emit the same wavelength, the spatial light modulation element illuminated by this illumination device displays an image signal corresponding to one color component, and the image display device The signal processing in is not made difficult.

  That is, the present invention is to maintain a sufficiently high luminance of illumination light and maintain a good white balance of a display image in an illumination device used for illuminating a spatial light modulation element in an image display device or the like. In particular, even when a solid-state light-emitting element is used as a light source, the life of the light source can be maintained sufficiently long, and signal processing in the image display apparatus becomes difficult. It is possible to provide an illuminating device having no illumination, and to provide an image display device using such an illuminating device.

  Hereinafter, the configuration of an illumination device according to the present invention and an image display device using the illumination device will be described in detail.

[First Embodiment]
FIG. 1 is a plan view showing the configuration of the image display apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, the image display apparatus includes a plurality of spatial light modulation elements 1R, 1G, and 1B, and these spatial light modulation elements 1R, 1G, and 1B correspond to the spatial light modulation elements 1R, 1G, and 1B. The image display device displays the image by illuminating with the illuminating device, and color-combining the modulated lights that have passed through the spatial light modulation elements 1R, 1G, and 1B.

  Each of the spatial light modulators 1R, 1G, and 1B displays the red component, the green component, and the blue component of the display image, respectively, and polarization-modulates the illumination light according to these images. In this embodiment, each of the spatial light modulators 1R, 1G, 1B is a transmissive type, and modulates and transmits the incident illumination light.

  Each lighting device illuminates the spatial light modulation element 1R for displaying the red component image with red illumination light, illuminates the spatial light modulation element 1G for displaying the green component image with green illumination light, and The spatial light modulation element 1B displaying an image is illuminated with blue illumination light.

The illumination device of this image display device uses solid-state light emitting elements 2R, 2G ₁ , 2G ₂ , 2B that emit red light, green light, and blue light as light sources. A solid light emitting element is a light emitting diode (LED), a semiconductor laser diode (LD), an electroluminescent element (EL), or the like. When the solid state light emitting devices 2R, 2G ₁ , 2G ₂ , 2B are light emitting diodes, the material forming these solid state light emitting devices 2R, 2G ₁ , 2G ₂ , 2B is AlGaAs, AlGaInP for red, or GaAsP, for green Is InGaN or AlGaInP, and blue is InGaN.

Among these illumination devices, the green illumination device that illuminates the spatial light modulation element 1G for green includes the first and second solid-state light emitting elements 2G ₁ and 2G ₂ as light sources. It becomes embodiment of the illuminating device which concerns on invention. The first and second solid state light emitting devices 2G ₁ and 2G ₂ emit illumination light having the same wavelength.

In this image display device, the red, green and blue solid-state light emitting elements 2R, 2G ₁ , 2G ₂ and 2B are controlled by independent drive circuits 3R, 3G ₁ , 3G ₂ and 3B, respectively. Emits light. These drive circuits 3R, 3G ₁ , 3G ₂ , 3B are controlled by a synchronous controller 4 serving as control means.

  The illumination light emitted from the red solid light emitting element 2R is incident on the red transmissive spatial light modulation element 1R via the relay lens 5R, the field lens 6R, and the polarizer 7R. The red illumination light is polarization-modulated by the transmissive spatial light modulator 1R according to the image signal of the red component, and enters the color synthesis prism 9 as red image light through the analyzer 8R.

  The illumination light emitted from the blue solid light emitting element 2B is incident on the blue transmissive spatial light modulation element 1B via the relay lens 5B, the field lens 6B, and the polarizer 7B. The blue illumination light is polarized and modulated in accordance with the image signal of the blue component by the transmissive spatial light modulator 1B, and enters the color synthesis prism 9 as blue image light through the analyzer 8B.

Then, the illumination light emitted from the solid light-emitting element 2G ₁ for the first green, through the relay lens 5G ₁ and the field lens 6G _1, is incident on the surface side of the rotary wheel 10 as a light path changing means. Further, illumination light emitted from the solid light emitting element 2G ₂ for a second green, through the relay lens 5G ₂ and the field lens 6G _2, is incident on the rear surface side of the rotary wheel 10. The optical axes of the illumination lights emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ are orthogonal to each other.

The rotating wheel 10 is configured in a disc shape, and at the position where the optical axes of the illumination light emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ intersect each of these optical axes. The main surface portion is arranged at an angle of 45 °.

  FIG. 2 is a front view showing the configuration of the rotating wheel 10.

  As shown in FIG. 2, each rotating wheel 10 is formed in a disk shape by a fan-shaped transmitting portion 10a and a reflecting portion (reflecting plate) 10b. As shown in FIG. 2A, each of the transmission part 10a and the reflection part 10b may have a disk shape with one surface as a sector having a central angle of 180 °, or in FIG. As shown in (b), each of the two surfaces may form a disc shape with a sector shape having a central angle of 90 °, or each may have a central angle [360 / 2n] ° (∵n: natural number). It is good also as what forms a disk shape by each n surface as a fan shape.

  As the reflecting portion 10b, a metal film such as aluminum or silver provided with a reflection-reflecting film can be used, and a low-pass, high-pass, or band-pass filter (dichroic mirror) using a dielectric film can be used. May be used.

The rotating wheel 10 is rotated by a motor 11 as shown in FIG. The motor 11 is rotationally driven by a motor drive circuit 12 controlled by the synchronous controller 4. The rotating wheel 10 is rotationally operated to convert (deflect) the optical paths of the illumination light emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ in a time division manner.

That is, when the rotating wheel 10 is rotated and the transmission part 10a is located at a position where the optical axes of the illumination lights emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ intersect, illumination light emitted from the solid light-emitting element 2G ₁ for green 1 is transmitted through the transmissive portion 10a. When the rotating wheel 10 is rotated and the reflecting portion 10b is located at a position where the optical axes of the illumination lights emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ intersect, solid-state light-emitting element 2G illumination light emitted from the ₂ for 2 green are converted to optical path is reflected by the reflective portion 10b.

Illumination light emitted from the _first solid-state light emitting element 2G1 for green and transmitted through the transmission part 10a of the rotating wheel 10, or reflected from the _second solid-state light emitting element 2G2 for green and the reflecting part 10b of the rotating wheel 10 The illumination light reflected by the light passes through the polarizer 7G and enters the green transmissive spatial light modulator 1G. The green illumination light is polarization-modulated by the transmissive spatial light modulator 1G according to the image signal of the green component, passes through the analyzer 8G, and enters the color synthesis prism 9 as green image light.

  The red, green, and blue image lights incident on the color combining prism 9 are color-combined and incident on a projection lens 13 serving as an image forming unit. The projection lens 13 projects image light of each color on a screen (not shown), enlarges it, forms an image, and displays an image.

  FIG. 3 is a timing chart showing the lighting state of each light source in the image display apparatus.

In this image display device, as shown in FIG. 3, the synchronous controller 4 continuously drives the red and blue solid light emitting elements 2R and 2B, respectively, and also uses the green solid light emitting elements 2G ₁ and 2G _2. Are sequentially driven in a time division manner. The synchronous controller 4 lights the green solid-state light emitting elements 2G ₁ and 2G ₂ in a time-sharing manner. In this embodiment, the synchronous controller 4 alternately turns on the solid light emitting elements 2G ₁ and 2G ₂ for green, and at least one of the solid light emitting elements 2G ₁ and 2G ₂ is always on. To control. In addition, the synchronous controller 4 lights the green solid-state light emitting elements 2G ₁ and 2G ₂ with the same lighting cycle and lighting time.

The reflecting portion 10b of the rotating wheel 10 is moved with respect to the optical path of the illumination light from each of the green light emitting elements 2G ₁ and 2G ₂ and is synchronized with the lighting period of the second green solid light emitting element 2G _2. are to enter, it is exit in synchronism with the first lighting period of the green solid-state light-emitting element 2G _1.

In this way, _one of the illumination lights from the green solid-state light emitting elements 2G ₁ and 2G ₂ is always incident on the green transmissive spatial light modulator 1G, and the red light Illumination light from the solid light emitting element 2R for red is always incident on the transmissive spatial light modulator 1R, and illumination light from the solid light emitting element 2B for blue is incident on the transmissive spatial light modulator 1B for blue. Is always incident, and a color image is displayed.

In the illumination device of the image display device, the plurality of solid state light emitting elements 2G ₁ and 2G ₂ that emit light of the same wavelength are alternately turned on in a time-division manner, and at least one of the light sources is always turned on. Controlled. Accordingly, each of the solid state light emitting devices 2G ₁ and 2G ₂ is driven with a rest period and the increase in junction temperature is suppressed, so that higher power can be input than in continuous driving, and the luminance of illumination light can be improved. it can. Since each of the solid light emitting elements 2G ₁ and 2G ₂ is lit with the same lighting cycle and lighting time, an increase in the junction temperature is effectively suppressed.

Therefore, in this image display device, it is possible to improve the luminance of the illumination light while suppressing an increase in the junction temperature for the green solid-state light emitting elements 2G ₁ and 2G _{2 having} a low luminous efficiency, and other colors (red) In addition, the white balance of the display image can be favorably maintained without lowering the luminance of the illumination light of blue.

  Further, in this image display device, the light source of each illumination device is always controlled so that at least one of the light sources is lit, so that the light emission period is continuous and the maximum illumination light The brightness can be maintained. In this image display device, when power equivalent to that for continuously driving the light source is applied, excessive heat generation can be suppressed, the life of the light source can be extended, and overall consumption Electric power can be reduced.

Furthermore, in this image display device, since the green solid-state light emitting elements 2G ₁ and 2G ₂ emit the same wavelength, the spatial light modulation element 1G illuminated by these solid-state light emitting elements 2G ₁ and 2G ₂ Since the image signal corresponding to the color component is displayed, signal processing in the image display device is not made difficult.

[Second Embodiment]
FIG. 4 is a plan view showing the configuration of the image display apparatus according to the second embodiment of the present invention.

  The image display apparatus according to the present invention is not limited to the configuration using the transmission type light modulation element as the light modulation element as in the above-described embodiment, and the reflection type light modulation element (so-called “LCOS”) or the like as the light modulation element. A configuration using “DMD” or the like may be used.

  As shown in FIG. 4, the image display device includes a plurality of spatial light modulation elements 21R, 21G, and 21B, and these spatial light modulation elements 21R, 21G, and 21B correspond to the spatial light modulation elements 21R, 21G, and 21B. Illuminated by the illuminating device, the modulated light that has passed through each of the spatial light modulation elements 21R, 21G, and 21B is color-synthesized and imaged to display an image. Each of the spatial light modulators 21R, 21G, and 21B displays the red component, the green component, and the blue component of the display image, respectively, and polarization-modulates the illumination light according to these images. In this embodiment, each of the spatial light modulation elements 21R, 21G, and 21B is of a reflective type, and modulates incident illumination light and reflects it.

  Each lighting device illuminates the spatial light modulation element 21R for displaying the red component image with red illumination light, illuminates the spatial light modulation element 21G for displaying the green component image with green illumination light, and The spatial light modulator 21B displaying the image is illuminated with blue illumination light.

The illumination device of this image display device uses solid-state light emitting elements 2R, 2G ₁ , 2G ₂ , 2B that emit red light, green light, and blue light as light sources. Among these illumination devices, the green illumination device that illuminates the spatial light modulation element 21G for green includes the first and second solid-state light emitting elements 2G ₁ and 2G ₂ as light sources. It becomes embodiment of the illuminating device which concerns on invention. The first and second solid state light emitting devices 2G ₁ and 2G ₂ emit illumination light having the same wavelength.

In this image display device, the red, green and blue solid-state light emitting elements 2R, 2G ₁ , 2G ₂ and 2B are controlled by independent drive circuits 3R, 3G ₁ , 3G ₂ and 3B, respectively. Emits light. These drive circuits 3R, 3G ₁ , 3G ₂ , 3B are controlled by a synchronous controller 4 serving as control means.

  Illumination light emitted from the solid light emitting element 2R for red passes through the collimator lens 14R, is made uniform in illuminance distribution through the first and second fly-eye lens arrays 15R and 16R, and is polarized by the polarization conversion element 17R. The direction can be aligned in a certain direction. The illumination light is incident on the polarization beam splitter 20R via the field lens 18R and the polarizer 19R.

  The illumination light that has entered the polarization beam splitter 20R is reflected by the polarization reflection film inclined at 45 ° with respect to the optical axis of the illumination light, is emitted from the polarization beam splitter 20R, and is transmitted through red. The light is incident on the light modulation element 21R. The red illumination light is polarization-modulated by the transmissive spatial light modulator 21R according to the image signal of the red component, reflected as red image light, and re-enters the polarization beam splitter 20R. The image light re-entering the polarization beam splitter 20R passes through the polarization reflection film, is emitted from the polarization beam splitter 20R, and enters the color synthesis prism 9 through the analyzer 22R.

  The illumination light emitted from the blue solid-state light emitting element 2B is made uniform in illuminance distribution through the first and second fly-eye lens arrays 15B and 16B through the collimator lens 14B, and is converted by the polarization conversion element 17B. The polarization direction can be aligned in a certain direction. The illumination light is incident on the polarization beam splitter 20B through the field lens 18B and the polarizer 19B.

  The illumination light incident on the polarization beam splitter 20B is reflected by the polarization reflection film inclined at 45 ° with respect to the optical axis of the illumination light, is emitted from the polarization beam splitter 20B, and is transmitted through blue. The light is incident on the light modulation element 21B. The blue illumination light is polarization-modulated by the transmissive spatial light modulator 21B according to the image signal of the blue component, reflected as blue image light, and reenters the polarization beam splitter 20B. The image light re-entering the polarization beam splitter 20B passes through the polarization reflection film, is emitted from the polarization beam splitter 20B, and enters the color synthesis prism 9 through the analyzer 22B.

The illumination light emitted from the first green solid-state light emitting element 2G ₁ is made uniform in illuminance distribution through the collimator lens 14G ₁ and the first and second fly-eye lens arrays 15G ₁ and 16G ₁ . It is, by the polarization conversion element 17G _1, is aligned in polarization direction in the predetermined direction. Then, the illumination light passes through the field lens 18G _1, is incident on the surface side of the rotary wheel 10 as a light path changing means. Also, the illumination light emitted from the second green solid-state light emitting element 2G ₂ is made uniform in illuminance distribution through the collimator lens 14G ₂ and the first and second fly-eye lens arrays 15G ₂ and 16G ₂ . It is, by the polarization conversion element 17G _2, is aligned in polarization direction in the predetermined direction. Then, the illumination light passes through the field lens 18G _2, is incident on the back side of the rotating wheel 10 as a light path changing means. The optical axes of the illumination lights emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ are orthogonal to each other.

As in the first embodiment described above, the rotating wheel 10 has a disk-shaped transmitting portion 10a and a reflecting portion 10b, each of which is configured in a disc shape, and the first and second green solids. At the position where the optical axes of the illumination light emitted from the light emitting elements 2G ₁ and 2G ₂ intersect, the main surface portion is arranged at an angle of 45 ° with respect to each of the optical axes.

The rotating wheel 10 is rotated by a motor 11. The motor 11 is rotationally driven by a motor drive circuit 12 controlled by the synchronous controller 4. The rotating wheel 10 is rotated to change the optical path of the illumination light emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ in a time division manner.

That is, when the rotating wheel 10 is rotated and the transmission part 10a is located at a position where the optical axes of the illumination lights emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ intersect, illumination light emitted from the solid light-emitting element 2G ₁ for green 1 is transmitted through the transmissive portion 10a. When the rotating wheel 10 is rotated and the reflecting portion 10b is located at a position where the optical axes of the illumination lights emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ intersect, solid-state light-emitting element 2G illumination light emitted from the ₂ for 2 green are converted to optical path is reflected by the reflective portion 10b.

Illumination light emitted from the _first solid-state light emitting element 2G1 for green and transmitted through the transmission part 10a of the rotating wheel 10, or reflected from the _second solid-state light emitting element 2G2 for green and the reflecting part 10b of the rotating wheel 10 The illumination light reflected by is incident on the polarization beam splitter 20G via the polarizer 19G.

  The illumination light that has entered the polarization beam splitter 20G is reflected by the polarization reflection film inclined at 45 ° with respect to the optical axis of the illumination light, is emitted from the polarization beam splitter 20G, and is transmitted through green. The light is incident on the light modulation element 21G. The green illumination light is polarization-modulated by the transmissive spatial light modulator 21G according to the image signal of the green component, reflected as green image light, and reenters the polarization beam splitter 20G. The image light re-entering the polarization beam splitter 20G passes through the polarization reflection film, is emitted from the polarization beam splitter 20G, enters the color synthesis prism 9 through the analyzer 22G.

  The red, green, and blue image lights incident on the color combining prism 9 are color-combined and incident on a projection lens 13 serving as an image forming unit. The projection lens 13 projects image light of each color on a screen (not shown), enlarges it, forms an image, and displays an image.

Also in this image display apparatus, the synchronous controller 4 continuously drives the red and blue solid-state light emitting elements 2R and 2B, respectively, and sequentially turns the green solid-state light emitting elements 2G ₁ and 2G ₂ in a time-division manner. Drive. The synchronous controller 4 lights the green solid-state light emitting elements 2G ₁ and 2G ₂ in a time-sharing manner. In this embodiment, the synchronous controller 4 alternately turns on the solid light emitting elements 2G ₁ and 2G ₂ for green, and at least one of the solid light emitting elements 2G ₁ and 2G ₂ is always on. To control. In addition, the synchronous controller 4 lights the green solid-state light emitting elements 2G ₁ and 2G ₂ with the same lighting cycle and lighting time.

The reflecting portion 10b of the rotating wheel 10 is moved with respect to the optical path of the illumination light from each of the green light emitting elements 2G ₁ and 2G ₂ and is synchronized with the lighting period of the second green solid light emitting element 2G _2. are to enter, it is exit in synchronism with the first lighting period of the green solid-state light-emitting element 2G _1.

In this way, any one of the illumination lights from the green solid-state light emitting elements 2G ₁ and 2G ₂ is always incident on the green transmissive spatial light modulator 21G, and the red light Illumination light from the solid light emitting element 2R for red is always incident on the transmissive spatial light modulator 21R, and illumination light from the solid light emitting element 2B for blue is incident on the transmissive spatial light modulator 21B for blue. Is always incident, and a color image is displayed.

  In this image display device, each lighting device may use a rod integrator or a light tunnel (light pipe) integrator instead of the first and second fly-eye lens arrays.

Also in the illumination device of the image display device, the plurality of solid state light emitting elements 2G ₁ and 2G ₂ that emit light of the same wavelength are alternately turned on in a time-division manner, and at least one of the light sources is always turned on. To be controlled. Accordingly, each of the solid state light emitting devices 2G ₁ and 2G ₂ is driven with a rest period and the increase in junction temperature is suppressed, so that higher power can be input than in continuous driving, and the luminance of illumination light can be improved. it can. Since each of the solid light emitting elements 2G ₁ and 2G ₂ is lit with the same lighting cycle and lighting time, an increase in the junction temperature is effectively suppressed.

Therefore, in this image display device, it is possible to improve the luminance of the illumination light while suppressing an increase in the junction temperature for the green solid-state light emitting elements 2G ₁ and 2G _{2 having} a low luminous efficiency, and other colors (red) In addition, the white balance of the display image can be favorably maintained without lowering the luminance of the illumination light of blue.

  Further, in this image display device, the light source of each illumination device is always controlled so that at least one of the light sources is lit, so that the light emission period is continuous and the maximum illumination light The brightness can be maintained. In this image display device, when power equivalent to that for continuously driving the light source is applied, excessive heat generation can be suppressed, the life of the light source can be extended, and overall consumption Electric power can be reduced.

Further, in this image display device, since the green solid-state light emitting elements 2G ₁ and 2G ₂ emit the same wavelength, the spatial light modulation element 21G illuminated by these solid-state light emitting elements 2G ₁ and 2G ₂ Since the image signal corresponding to the color component is displayed, signal processing in the image display device is not made difficult.

[Third Embodiment]
In each of the above-described embodiments, as the optical path changing means in the illumination device according to the present invention, the rotating wheel 10 having a disk-shaped transmitting portion 10a and a reflecting portion 10b, each having a disk shape, is used. The optical path changing means in the present invention is not limited to the rotating wheel 10.

  FIG. 5 is a plan view showing the configuration of the image display apparatus according to the third embodiment of the present invention.

  That is, as shown in FIG. 5, this image display device is configured in the same manner as in the first or second embodiment described above, and is rotated as an optical path changing means instead of the rotating wheel 10. You may comprise using the reflecting plate 23 which is.

  FIG. 6 is a front view showing the configuration of the reflecting plate 23 serving as an optical path changing means in the image display device.

As shown in FIG. 6, the reflecting plate 23 is formed in a flat plate shape and is supported so as to be rotatable about a support shaft 24 along one side. A rotary motor 25 is attached to the support shaft 24. The reflecting plate 23 is rotated about the support shaft 24 by the rotation motor 25 through the support shaft 24. The rotary motor 25 is rotationally driven by the motor drive circuit 12 controlled by the synchronous controller 4 as in the above-described embodiment. The reflection plate 23 is rotated to change the optical path of the illumination light emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ in a time division manner.

That is, the reflecting plate 23 is rotated, and the optical axes of the illumination light emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ intersect with each of the optical axes. when it is made a condition that an angle of 45 ° the surface portion, the illumination light emitted from the solid light emitting element 2G ₂ for second green is converted to the optical path is reflected by the reflecting plate 23. When the reflecting plate 23 is rotated and the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ are withdrawn from the position where the optical axes of the illumination lights intersect, illumination light emitted from the solid light-emitting element 2G ₁ for green is passed into this position.

The illumination light emitted from the first green solid-state light-emitting element 2G ₁ or the illumination light emitted from the second green solid-state light-emitting element 2G ₂ and reflected by the reflector 23 is a green spatial light. The light enters the color synthesis prism 9 through the modulation elements 1G and 21G.

Also in this image display apparatus, the synchronous controller 4 continuously drives the red and blue solid-state light emitting elements 2R and 2B, respectively, and sequentially turns the green solid-state light emitting elements 2G ₁ and 2G ₂ in a time-division manner. Drive. The synchronous controller 4 lights the green solid-state light emitting elements 2G ₁ and 2G ₂ in a time-sharing manner. In this embodiment, the synchronous controller 4 alternately turns on the solid light emitting elements 2G ₁ and 2G ₂ for green, and at least one of the solid light emitting elements 2G ₁ and 2G ₂ is always on. To control. In addition, the synchronous controller 4 lights the green solid-state light emitting elements 2G ₁ and 2G ₂ with the same lighting cycle and lighting time.

Then, the reflector 23 is moved with respect to the optical path of the illumination light from each of the green solid light emitting elements 2G ₁ and 2G ₂ and enters in synchronization with the lighting period of the second green solid light emitting element 2G _2. is exit in synchronism with the first lighting period of the green solid-state light-emitting element 2G _1.

In this way, either one of the illumination lights from the green solid light emitting elements 2G ₁ and 2G ₂ is always incident on the green spatial light modulation elements 1G and 21G, and the red light Illumination light from the solid light emitting element 2R for red is always incident on the transmissive spatial light modulator 21R, and illumination light from the solid light emitting element 2B for blue is incident on the transmissive spatial light modulator 21B for blue. Is always incident, and a color image is displayed.

  FIG. 7 is a front view showing another configuration example (using a rotary motor) of the optical path changing means in this image display device.

Further, as shown in FIG. 7, the reflection plate 23 may be formed in a flat plate shape and have a support shaft 26 perpendicular to the main surface portion at the side edge portion. A rotary motor 25 is attached to the support shaft 26. The reflecting plate 23 is rotated in a plane along the main surface portion around the support shaft 26 by the rotation motor 25 via the support shaft 26. The rotary motor 25 is rotationally driven by the motor drive circuit 12 controlled by the synchronous controller 4 as in the above-described embodiment. The reflection plate 23 is rotated to change the optical path of the illumination light emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ in a time division manner.

That is, the reflecting plate 23 is rotated, and the optical axes of the illumination light emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ intersect with each of the optical axes. when it is made a condition that an angle of 45 ° the surface portion, the illumination light emitted from the solid light emitting element 2G ₂ for second green is converted to the optical path is reflected by the reflecting plate 23. When the reflecting plate 23 is rotated and the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ are withdrawn from the position where the optical axes of the illumination lights intersect, illumination light emitted from the solid light-emitting element 2G ₁ for green is passed into this position.

The illumination light emitted from the first green solid-state light-emitting element 2G ₁ or the illumination light emitted from the second green solid-state light-emitting element 2G ₂ and reflected by the reflector 23 is a green spatial light. The light enters the color synthesis prism 9 through the modulation elements 1G and 21G.

Also in this case, the synchronous controller 4 continuously drives the red and blue solid-state light emitting elements 2R and 2B, and sequentially drives the green solid-state light emitting elements 2G ₁ and 2G ₂ in a time-division manner. . The synchronous controller 4 controls the green solid-state light emitting elements 2G ₁ and 2G ₂ to alternately turn on in a time-division manner so that at least one of the solid-state light emitting elements 2G ₁ and 2G ₂ is always on. To do. In addition, the synchronous controller 4 lights the green solid-state light emitting elements 2G ₁ and 2G ₂ with the same lighting cycle and lighting time.

Then, the reflector 23 is moved with respect to the optical path of the illumination light from each of the green solid light emitting elements 2G ₁ and 2G ₂ and enters in synchronization with the lighting period of the second green solid light emitting element 2G _2. is exit in synchronism with the first lighting period of the green solid-state light-emitting element 2G _1.

In this way, either one of the illumination lights from the green solid light emitting elements 2G ₁ and 2G ₂ is always incident on the green spatial light modulation elements 1G and 21G, and the red light Illumination light from the solid light emitting element 2R for red is always incident on the transmissive spatial light modulator 21R, and illumination light from the solid light emitting element 2B for blue is incident on the transmissive spatial light modulator 21B for blue. Is always incident, and a color image is displayed.

  FIG. 8 is a front view showing still another configuration example (using a linear motor) of the optical path changing means in this image display device.

Further, as shown in FIG. 8, the reflection plate 23 may be formed in a flat plate shape, and a linear motor 27 may be attached to the side edge portion. The reflecting plate 23 is moved (slided) by a linear motor 27 along a side edge portion within a plane along the main surface portion. The linear motor 27 is rotationally driven by the motor drive circuit 12 controlled by the synchronous controller 4 as in the above-described embodiment. The reflector 23 is operated to move, and time-divisionally converts the optical paths of the illumination light emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ .

That is, the reflecting plate 23 is moved, and the main surface portion of each of the optical axes of the illumination light emitted from the first and second solid-state light emitting elements 2G ₁ and 2G ₂ for green intersects each of the optical axes. when was made a state that an angle of 45 °, the illumination light emitted from the solid light emitting element 2G ₂ for second green is converted to the optical path is reflected by the reflecting plate 23. When the reflecting plate 23 is moved and moved out of the position where the optical axes of the illumination lights emitted from the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ intersect, the first green color is emitted. illumination light emitted from the solid state light element 2G ₁ use passes through this position.

The illumination light emitted from the first green solid-state light-emitting element 2G ₁ or the illumination light emitted from the second green solid-state light-emitting element 2G ₂ and reflected by the reflector 23 is a green spatial light. The light enters the color synthesis prism 9 through the modulation elements 1G and 21G.

Also in this case, the synchronous controller 4 continuously drives the red and blue solid-state light emitting elements 2R and 2B, and sequentially drives the green solid-state light emitting elements 2G ₁ and 2G ₂ in a time-division manner. . The synchronous controller 4 controls the green solid-state light emitting elements 2G ₁ and 2G ₂ to alternately turn on in a time-division manner so that at least one of the solid-state light emitting elements 2G ₁ and 2G ₂ is always on. To do. In addition, the synchronous controller 4 lights the green solid-state light emitting elements 2G ₁ and 2G ₂ with the same lighting cycle and lighting time.

Then, the reflector 23 is moved with respect to the optical path of the illumination light from each of the green solid light emitting elements 2G ₁ and 2G ₂ and enters in synchronization with the lighting period of the second green solid light emitting element 2G _2. is exit in synchronism with the first lighting period of the green solid-state light-emitting element 2G _1.

In this way, either one of the illumination lights from the green solid light emitting elements 2G ₁ and 2G ₂ is always incident on the green spatial light modulation elements 1G and 21G, and the red light Illumination light from the solid light emitting element 2R for red is always incident on the transmissive spatial light modulator 21R, and illumination light from the solid light emitting element 2B for blue is incident on the transmissive spatial light modulator 21B for blue. Is always incident, and a color image is displayed.

In the illuminating device according to the present invention, the optical path changing means is not limited to one having a reflecting portion (reflecting plate) as shown in each of the above-described embodiments, and a polarizing film may be used. Good. In this case, for example, the illumination light emitted from the _first solid-state light emitting element 2G1 for green is set in a P-polarized state with respect to the polarizing film, and the illumination emitted from the _second solid-state light emitting element 2G2 for green is used. The light is set in an S-polarized state with respect to the polarizing film. Then, the illumination light emitted from the solid light-emitting element 2G ₁ for the first green is transmitted through the polarizing film, the illumination light emitted from the solid light emitting element 2G ₂ for second green is reflected by the polarizing film The light paths of the illumination lights from the green solid-state light emitting elements 2G ₁ and 2G ₂ are combined to illuminate the same green spatial light modulation elements 1G and 21G.

[Fourth Embodiment]
The illumination device according to the present invention is not limited to the configuration having the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ as the plurality of light sources, as in each of the above-described embodiments. As above, a plurality of red solid-state light emitting devices or a plurality of blue solid-state light emitting devices may be used.

  Further, the image display device according to the present invention is not limited to a configuration in which only the green illumination device has a plurality of light sources as in the above-described embodiments, but only the red illumination device. May be configured to have a plurality of light sources, or only the blue illumination device may have a plurality of light sources. Further, in the image display device according to the present invention, the green and red illumination devices have a plurality of light sources, and the red and blue illumination devices have a plurality of light sources. Or the blue and green lighting devices have a plurality of light sources, or the red, green and blue color lighting devices all have a plurality of light sources. It is good also as a structure.

  Moreover, in the illuminating device which concerns on this invention, it is not limited to the structure which has a solid light emitting element as a light source, It is good also as a structure which has light emission means, such as a discharge lamp, as a light source.

  Furthermore, the illumination device according to the present invention is not limited to a configuration having two light sources as a plurality of light sources as in each of the above-described embodiments, and may have a configuration having three or more light sources.

  FIG. 9 is a plan view showing a configuration of a lighting device according to the present invention having three or more light sources.

  When the illumination device according to the present invention has a configuration having three or more light sources, as shown in FIG. 9, when the number of these light sources L1, L2, L3. -1] optical path changing means M1, M2, M3... L (m-1) are provided, and the illumination light emitted from any one of these light sources illuminates the same spatial light modulator P. Like that. The optical axis of the illumination light emitted from each of the light sources L1, L2, L3,... Lm is all the other light sources L1, L2, L3, ··· with respect to the optical axis of the illumination light emitted from one light source Lm. ..The optical axis of illumination light emitted from L (m-1) is in a direction that is orthogonal.

  When each of these optical path conversion means M1, M2, M3... L (m-1) is configured as a rotating wheel, as in the above-described embodiment, the reflecting portion in each rotating wheel has a central angle [ 360 / (m · n)] ° (∵n: natural number) as a sector shape, which is provided evenly (at equal angular intervals) at n locations. Each rotating wheel is rotated at the same speed while maintaining the state where the reflecting portions are shifted from each other by [360 / (m · n)] °. By rotating each rotating wheel in this manner, only one of the rotating wheels has the reflecting portion entering the optical path, and all the rotating wheels have the reflecting portion exit the optical path. The state will be repeated.

  When only one of the rotating wheels has the reflecting portion entering the optical path, only the light source corresponding to the rotating wheel having the reflecting portion entering the optical path is turned on, and all the rotating wheels have the reflecting portion. When leaving the optical path, only the corresponding light source Lm without a rotating wheel is turned on. Thus, by synchronizing the rotation of the rotating wheel and the lighting of each light source, the illumination light emitted from only one of the light sources reaches the spatial light modulator P.

[Fifth Embodiment]
In each of the embodiments described above, the lighting device according to the present invention is provided with temperature detection means for detecting the environmental temperature, and the lighting frequencies of the plurality of light sources are controlled based on the environmental temperature detected by the temperature detection means. Can be configured.

  FIG. 10 is a plan view showing the configuration of the image display device according to the fifth embodiment of the present invention.

  That is, this illuminating device has an outside air temperature monitor 30 serving as a temperature detecting means, as shown in FIG. The outside air temperature monitor 30 detects the environmental temperature (outside air temperature). The detection result by the outside air temperature monitor 30 is sent to the synchronous controller 4 serving as the control means via the calculator 31. Other configurations are the same as those in the first embodiment described above.

  In addition, in FIG. 10, although the structure which added the outside temperature monitor 30 to the illuminating device in the above-mentioned 1st Embodiment is shown, also about the illuminating device in the above-mentioned 2nd thru | or 4th embodiment, Similarly, an outside air temperature monitor 30 can be added.

The synchronous controller 4 controls the lighting frequencies of a plurality of light sources (for example, the first and second green solid-state light emitting elements 2G ₁ and 2G ₂ ) based on the environmental temperature detected by the outside air temperature monitor 30. With this control, the synchronous controller 4 keeps the light emitting unit temperatures (junction temperatures) of the plurality of light sources below a predetermined temperature.

  FIG. 11 is a graph (characteristic curve) showing the relationship between the lighting time of a solid state light emitting device (LED) and the thermal resistance value.

For example, for a light emitting diode (LED), as shown in FIG. 11, when the lighting time exceeds 1.0 × 10 ⁻³ seconds, the thermal resistance value rapidly increases and the lighting time is 1.0 × 10 ^−1. If it exceeds 2 seconds, the thermal resistance value is saturated at about 1.25 (° C / W). And the junction temperature of a light emitting diode is also influenced by environmental temperature (outside temperature), and can be shown with the following formula | equation.
[Junction temperature] = [Environment temperature] + [Average lighting temperature] + [Lighting temperature]

When two light emitting diodes are alternately lit at equal intervals and controlled so that one of them is always lit, the duty ratio is 50%, the lighting frequency is 100 Hz, the driving power is 100 W, the environment When the temperature is 25 ° C., the junction temperature is calculated as follows.
25 (° C) +50 (W) × 1.25 (° C / W) +100 (W) × 0.5 (° C / W) = 25 + 62.5 + 50≈137.5 (° C.)

  In this case, in order for the synchronous controller 4 to control the lighting frequency so that the junction temperature is 100 ° C. or lower, the lighting temperature may be 12.5 ° C. or lower. May be about 1.7 kHz or more.

  In addition, when the environmental temperature is 35 ° C. under the above-described conditions, the lighting temperature needs to be 2.5 ° C. or lower in order for the junction temperature to be 100 ° C. or lower. The frequency needs to be 100 kHz or more.

  Thus, in this lighting device, the synchronous controller 4 controls the lighting frequency of the plurality of light sources based on the environmental temperature, so that the junction temperature of the solid state light emitting element can be suppressed to a predetermined temperature or less, and the illumination light level is increased. It is possible to achieve both luminance enhancement and long life of the light source.

It is a top view which shows the structure in 1st Embodiment of the image display apparatus which concerns on this invention. It is a front view which shows the structure of the rotating wheel in the said image display apparatus. It is a timing chart which shows the lighting state of each light source in the image display device. It is a top view which shows the structure in 2nd Embodiment of the image display apparatus which concerns on this invention. It is a top view which shows the structure in 3rd Embodiment of the image display apparatus which concerns on this invention. It is a front view which shows the structure of the optical path conversion means in the said image display apparatus. It is a front view which shows the other structural example (thing using a rotary motor) of the optical path changing means in the said image display apparatus. It is a front view which shows the further another structural example (thing using a linear motor) of the optical path changing means in the said image display apparatus. It is a top view which shows the structure of the illuminating device which concerns on this invention which has a 3 or more light source. It is a top view which shows the structure in 5th Embodiment of the image display apparatus which concerns on this invention. It is a graph (characteristic curve) which shows the relationship between the lighting time of a solid light emitting element (LED), and a thermal resistance value. It is a top view which shows the structure of the conventional image display apparatus. It is a timing chart which shows the lighting state of each light source in the conventional image display apparatus. It is a timing chart which shows the other example of the lighting state of each light source in the conventional image display apparatus.

Explanation of symbols

1R Red transmissive spatial light modulator 1G Green transmissive spatial light modulator 1B Blue transmissive spatial light modulator 2R Red solid light emitting element 2G ₁ First green solid light emitting element
2G ₂ Solid light emitting element for first green 2B Solid light emitting element for blue 4 Synchronous controller 10 Rotating wheel 13 Projection lens 21R Reflective spatial light modulator 21G for red Reflective spatial light modulator 21B for green 21B For blue Reflective spatial light modulator 23 Reflector 30 Outside temperature monitor

Claims (4)

A plurality of light sources emitting light of the same wavelength;
Control means for controlling lighting of each light source;
Optical path conversion means for converting an optical path for at least one of the light from each light source and guiding the light from each light source to the same spatial light modulation element, and
The lighting device characterized in that the control means controls the light sources to light up in a time-sharing manner. The optical path conversion means has a reflecting plate that reflects light from the light source, and moves the reflecting plate relative to the optical path of the light from the light source in synchronization with the lighting cycle of the light source. The lighting device according to claim 1, wherein the light path of the light from the light is converted in a time-sharing manner. Equipped with temperature detection means for detecting the environmental temperature,
The said control means controls the light emission part temperature of each said light source to below predetermined temperature by controlling the lighting frequency of each said light source based on the environmental temperature detected by the said temperature detection means, It is characterized by the above-mentioned. Claim | item 1 or the illuminating device of Claim 2. A plurality of spatial light modulators;
An illumination device that is provided corresponding to each of the spatial light modulation elements and illuminates the corresponding spatial light modulation element;
An image forming means for combining the modulated light emitted from the illumination device and passing through the spatial light modulation elements to form an image;
At least one of the lighting devices is the lighting device according to any one of claims 1 to 3. An image display device, wherein:

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