JPH09105900A - Optical write system projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the influence of lighting unevenness of a light source image and prevent an image from blurring while reducing the size of the device. SOLUTION: This device is equipped with a write optical part 1 consisting of a write light source 7 and a Koehler lighting optical system 8, a liquid crystal image forming device 2, an image forming optical part 3, a spatial optical modulating element 4, a projection part 5, and a screen 6. The light source light of the write light source 7 is made into parallel luminous flux by the Koehler lighting optical system 8 and inputted to the liquid crystal image forming device 2. On the liquid crystal image forming device 2, none of light source images of the filament, electrode, etc., of the light source 7 is formed, and consequently a write image formed on the spatial optical modulating element 4 through the image forming optical part 3 is prevented from becoming uneven is luminance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention inputs two-dimensional light information such as an image or a data pattern into a spatial light modulator using writing light, and uses display light to display this information two-dimensionally. The present invention relates to an optical writing projection display device having a function.

SUMMARY OF THE INVENTION The present invention provides, as an optical system for illuminating a liquid crystal image forming apparatus, a Koehler illuminating optical system in which output light from a light source is transmitted as a parallel light flux on a liquid crystal image forming apparatus which is an illumination object. By using it, it is possible to prevent a light source image such as an electrode of a light source or a filament from being formed on an illuminated object, and to obtain a written image that is not affected by uneven illumination due to the light source image.

Further, by using a fly-eye lens composed of a large number of rectangular microlenses in an optical system for illuminating the liquid crystal image forming apparatus, the writing image is multi-sourced and the light flux from each of the microlenses is formed in the liquid crystal image forming apparatus. The illumination intensity can be made spatially uniform and the light utilization rate can be improved.

Furthermore, by using a telecentric optical system arranged so that the principal ray passes through the focal point of the imaging lens as means for forming an optical image on the spatial light modulator, the optical axis direction of the spatial light modulator is increased. The size of the written image formed on the photoconductive layer of the spatial light modulator does not change with respect to the movement, and high-precision image display is enabled. Further, in the projection of a full-color image, the registration image size of each color does not change, which facilitates registration adjustment.
This makes it possible to display a high quality projected image.

[0005]

2. Description of the Related Art Conventionally, as an optical writing type projection display device including a light writing type spatial light modulating element using a light scattering liquid crystal layer having a high light transmittance and a photoconductive layer without requiring a polarizing plate. Are known in the following literature (literature: K.Takizawa, H.Kikuchi, H.Fujikake, So
ciety for Information Displays (SID) International
Symposium Digest of Technical Papers Vol.22, p.250
-p.253, 1991).

The device described in this document, as shown in FIG.
For each color of green (G), red (R), and blue (B),
Liquid crystal image forming apparatuses 101G, 101R and 101B, relay lenses 102G, 102R and 102B, and spatial light modulators 103G, 103R and 103B are provided. Liquid crystal image forming devices 101G, 101R, 101B
A blue writing light is incident on. By the incident blue writing light, each of the liquid crystal image forming devices 101G, 101R,
The image light displayed on 101B is transmitted to the relay lens 102.
Each spatial light modulator 10 via G, 102R, and 102B
Written in 3G, 103R, 103B.

On the other hand, each spatial light modulator 103G, 103
The images written in R and 103B are the display light source 104,
The reading light supplied through the condenser lens 105, the reflecting lens 107, the dichroic mirror 108, and the dichroic mirror 109 reads out the light, combines the dichroic mirrors 109 and 108, and the lens
07, it is projected on the screen 111 via the lens 110. As a result, the enlarged image is displayed on the screen 11
Can be displayed on one.

In this case, each spatial light modulator 103
As shown in FIG. 9, G, 103R, and 103B are the first transparent electrode 121, the photoconductive layer 122, and the light absorption layer 123.
A dielectric multilayer mirror 124, a light modulation layer 125,
The second transparent electrode 126 and the transparent substrate 127 are provided, and in the state in which the AC voltage is applied from the driving AC power source 129 via the lead wire 128, the photoconductive layer 122 is photoconductive from the left side of FIG. When the writing light 130 that induces the effect is incident, the light modulation layer 125 is driven according to the light intensity of the writing light 130, and when the reading light 131 is irradiated from the right side of FIG. 9, writing is performed. The optical image is emitted as display light (reflected light) 132.

[0009]

However, the conventional optical writing projection display device described above has the following problems.

First, as shown in FIG. 10, when the liquid crystal image forming apparatus 101, which is an apparatus for displaying a writing image, is illuminated by the writing light source 142 of the writing optical section 141, an electrode of the writing light source 142 and a filament image ( Since the light source image) is generated on the liquid crystal image forming apparatus 101 which is the irradiation surface, the light intensity unevenness appears in the optical image input to the spatial light modulator 103, and this causes unevenness in the modulation of the projected image, which is a factor that significantly deteriorates the image quality. Has become.

Second, the writing light image of the spatial light modulator 101 needs a light intensity sufficient for the sensitivity of the photoconductive layer 122, but the loss in the writing optical system is large, and the light utilization rate of the light source is large. If the value becomes worse, it is not possible to secure a sufficient light intensity for the modulation of the spatial light modulator 101, and a high-luminance projection image cannot be obtained. Further, the writing light source 142 and the entire display device are increased in size.

Thirdly, as shown in FIG. 11, a general image forming system for forming an optical image formed by the liquid crystal image forming apparatus 101 on the spatial light modulator by the relay lens 102 is used for the writing optical system. Therefore, the spatial light modulator 10
In the third photoconductive layer 122, the size of the light image changes, causing image blurring. Therefore, the resolution of the spatial light modulator 103 is significantly reduced, and a highly accurate projected image cannot be obtained. Furthermore, when projecting a full-color image,
Since the written image size of each color varies depending on the adjustment of the optical system, registration adjustment is difficult.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to achieve the miniaturization of an apparatus while avoiding the influence of illumination unevenness due to a light source image and preventing the occurrence of image blurring. An object is to provide an optical writing projection display device.

[0014]

In order to achieve the above-mentioned object, the invention of claim 1 is such that the first transparent electrode and the first transparent electrode are laminated, and the impedance changes according to the intensity of incident light. A photoconductive layer, a light absorption layer laminated on the photoconductive layer, a dielectric multilayer mirror which is laminated on the light absorption layer and reflects all or part of the visible light spectrum, and the dielectric multilayer film. At least a light modulation layer laminated on the mirror and a second transparent electrode laminated on the light modulation layer are provided, and driven by an AC voltage applied between the first transparent electrode and the second transparent electrode. It has a spatial light modulator and a visible light source, and irradiates the spatial light modulator with the visible light as read light, and projects the reflected light of the spatial light modulator with respect to the read light as display light on a screen. Projection optics A liquid crystal image forming apparatus for displaying an input image, a writing light source having a spectrum sensitive to a photoconductive layer of the spatial light modulator, and a Koehler generating illumination light for illuminating the liquid crystal image forming apparatus from the writing light source. It is characterized by comprising a writing optical section having an illumination optical system and an image forming optical section for forming an optical image of the liquid crystal image forming apparatus on a photoconductive layer of the spatial light modulator.

According to a second aspect of the present invention, a first transparent electrode, a photoconductive layer which is laminated on the first transparent electrode and whose impedance changes according to the intensity of incident light, and a photoconductive layer which is laminated on the photoconductive layer. A light absorption layer, a dielectric multilayer film mirror laminated on the light absorption layer and reflecting all or part of a visible light spectrum, and a light modulation layer laminated on the dielectric multilayer film mirror,
At least a second transparent electrode laminated on the light modulation layer, and spatial light for each of blue, green and red that is driven by an AC voltage applied between the first transparent electrode and the second transparent electrode. It has a modulation element and a visible light source, separates the visible light from this visible light source into blue, green and red light and irradiates each spatial light modulation element as read-out light. The projection optical unit that synthesizes the reflected light from the spatial light modulator to project it on the screen as display light, each separate liquid crystal image forming apparatus that forms blue, green, and red input images, and each photoconductive layer are sensitive. A writing optical section having a writing light source having a spectrum of, and a Kohler illumination optical system that generates illumination light that illuminates each of the liquid crystal image forming apparatuses from the writing light source,
A division unit including an optical element that divides the illumination light emitted from the writing optical unit into three and outputs the divided illumination light to each of the liquid crystal image forming devices; and an optical image of each of the liquid crystal image forming devices, the optical image of each of the spatial light modulating devices. And an image forming optical section for each of blue, green and red for forming an image on the photoconductive layer.

According to a third aspect of the present invention, in the optically writable projection display device according to the first or second aspect, the light modulation layer constituting the spatial light modulation element is a nematic liquid crystal, a cholesteric liquid crystal, a smectic liquid crystal, or the like. At least one liquid crystal selected from the group consisting of a mixture of nematic liquid crystal, cholesteric liquid crystal, and smectic liquid crystal, or a nematic having a transparent resin with a preset refractive index and an ordinary light refractive index equivalent to this transparent resin. A liquid crystal / resin composite in which any one of liquid crystal, cholesteric liquid crystal, smectic liquid crystal, or a mixed liquid crystal of these liquid crystals is dispersed, or a liquid crystal / resin composite in which the transparent resin is dispersed in these liquid crystals. It has a feature.

The invention of claim 4 is the invention of claim 1, 2 or 3.
In the optical writing projection display device described in
The writing optical unit is characterized by having a fly-eye lens that converts a non-uniform light beam emitted from a writing light source into a rectangular uniform light beam.

According to a fifth aspect of the present invention, in the optical writing projection display device according to the fourth aspect, the aspect ratio of the luminous flux of illumination by the fly-eye lens matches the aspect ratio of the liquid crystal image forming apparatus. There is.

The invention of claim 6 is based on claims 1, 2, 3,
The optical writing projection display device according to any one of 4 and 5 is characterized in that the image forming optical unit includes a telecentric optical system.

[0020]

1 is a block diagram showing an embodiment of an optical writing projection display device according to the present invention.

The optical writing type projection display apparatus shown in this figure comprises a writing optical section 1, a liquid crystal image forming apparatus 2,
Imaging optical unit 3, spatial light modulator 4, and projection optical unit 5
And a screen 6.

The writing optical unit 1 includes a writing light source 7 and a Kohler illumination optical system 8. This Koehler illumination optical system 8 is provided on the liquid crystal image forming apparatus 2 which is an illumination object.
This is an illumination optical system in which light from a light source is transmitted as a parallel light flux, and has an effect as shown in FIG.

The liquid crystal image forming apparatus 2 is, for example, a TFT.
(Thin Film Transistor) Equipped with an active liquid crystal panel to display the input monochrome video signal as an image.

The image forming optical unit 3 is provided with an image forming lens 9 and guides the written image displayed on the liquid crystal image forming apparatus 2 to form an image on the spatial light modulator 4.

The spatial light modulator 4, as shown in FIG.
First transparent electrode 11, photoconductive layer 12, and light absorption layer 13
A dielectric multilayer film mirror 14, a light modulation layer 15, and a second
The transparent electrode 16 and the transparent substrate 17 are provided, and the photoconductive effect of the photoconductive layer 12 is shown from the left side of FIG. 2 in a state where an AC voltage is applied from a driving AC power source 19 via a lead wire 18. When the inducing writing light 20 is incident, the light modulation layer 15 is driven according to the light intensity of the writing light 20, while the reading light 21 is irradiated from the right side of FIG. Is emitted as display light (reflected light) 22.

First transparent electrode 11 and second transparent electrode 16
Is a thin film of In ₂ O ₃ : Sn or the like that is adhered to one surface of the photoconductive layer 12 or one surface of the transparent substrate 17 by a method such as vapor deposition. Each voltage of the driving AC power supply 19 is connected via the lead wire 18. Connected to the output terminal.

The photoconductive layer 12 has CdS and C whose electric impedance is significantly reduced with respect to the incidence of the writing light 20.
dSe, Se, SeTe, GaAs, GaP, Bi ₁₂ S
iO ₂₀ , Bi ₁₂ GeO ₂₀ , Si, amorphous Se, amorphous Si, amorphous SiC, amorphous S
This layer is made of a material such as eTe, SeAs, and amorphous SeAs.

The light absorption layer 13 is one or more films selected from the group consisting of a CdTe film, a diamond-like carbon film, an amorphous film substantially composed of silicon, carbon and germanium, or an inorganic pigment. , A resin composite in which one or more materials selected from the group consisting of organic pigments, carbon, and dyes are dispersed in a resin.

The dielectric multilayer mirror 14 is composed of a SiO ₂ film,
TiO ₂ film, HfO ₂ film, Ta ₂ O ₅ film, ZnS film, A
l ₂ O ₃ film, Na ₂ AlF ₆ film, MgF ₂ film, LaF ₃
Any one of a film, a GdF ₃ film, a SmF ₃ film, a CeF ₃ film, a ZrO ₂ film and a CeO ₂ film, or a multilayer film in which two or more films selected from these are stacked.

Further, the light modulation layer 15 is composed of a liquid crystal / resin composite comprising a transparent resin 23 formed in a plate shape and liquid crystal droplets 24 dispersed in the transparent resin 23 substantially uniformly. There is. Liquid crystals as the liquid crystal forming droplets 24, good ones refractive index n _p equivalent value of the ordinary refractive index n _o is a transparent resin 23. Further, the refractive index anisotropy Δn (=
It is desirable that n _e −n _o ) be as large as possible. As a liquid crystal satisfying such a condition, a nematic liquid crystal having a large refractive index anisotropy Δn, a cholesteric liquid crystal, a smectic liquid crystal, or a liquid crystal mixture of these liquid crystals is used. However, a nematic liquid crystal having low viscosity and high elasticity is suitable for obtaining high speed. Among them, nematic liquid crystals of cyanobiphenyl type, terphenyl type, pyridine type, pyrimidine type and tolan type having a large refractive index anisotropy Δn are particularly suitable.

In this embodiment, the light modulation layer 15
The liquid crystal / resin composite is composed of the liquid crystal droplets 24 which are dispersed almost uniformly in the transparent resin 23. However, the liquid crystal / resin composite is formed by dispersing the transparent resin in the liquid crystal. Further, it may be composed of any one or more liquid crystals of the group consisting of nematic liquid crystals, cholesteric liquid crystals, smectic liquid crystals, and mixtures of these nematic liquid crystals, cholesteric liquid crystals and smectic liquid crystals.

Further, as the transparent resin 23, polymerization is promoted by ultraviolet rays, and the refractive index n _p at the time of curing is 1.52.
Degree acrylic resin, methacrylic resin, epoxy resin,
A urethane resin, polystyrene, polyvinyl alcohol, or a copolymer thereof (for example, an acrylic / urethane copolymer) is suitable.

The transparent substrate 17 is a portion to be a substrate of this optical writing type spatial light modulator, and is made of glass having high transparency and excellent flatness, or synthetic resin such as acryl.

The projection optical unit 5 blocks a white light source 31 for display, which is composed of a xenon lamp, a halogen lamp, a metal halide lamp, etc., and blocks ultraviolet light and infrared light contained in visible light from the white light source 31. Bandpass filter 32, a condensing lens 33 that condenses visible light that has passed through this bandpass filter 32, a reflecting mirror 34 that receives and reflects the light condensed by this condensing lens 33, and The light reflected by the reflection mirror 34 is received and emitted as the readout light 21 of the spatial light modulator 4, and
A lens 35 that receives the optical image written in the spatial light modulator 4 and emits it as display light (reflected light) 22, and a projector that projects the display light 22 emitted from this lens 35 and projects it on the screen 6. And an optical lens 36.

Next, the operation of this embodiment will be described.

First, the operation of the spatial light modulator 4 of the optical writing type will be described. When driving the spatial light modulator 4, an AC voltage is applied between the first transparent electrode 11 and the second transparent electrode 16. . The writing light 20 imaged through the imaging optical unit 3 enters from the photoconductive layer 12 side. On the other hand, the read light 21 condensed via the lens 35 is the light modulation layer 1
The light is incident from the 5 side and undergoes light intensity modulation accompanied by light scattering in the light modulation layer 15. The modulated readout light 21 is reflected by the dielectric multilayer film mirror 14 and becomes display light 22. The read light 21 leaked from the dielectric multilayer film mirror 14 is absorbed by the light absorption layer 13. At this time, when the writing light 20 is extremely weak or does not enter, most of the driving voltage is applied to the photoconductive layer 4 side having a higher electrical impedance than the light modulation layer 15. Therefore, the alignment direction of the liquid crystal molecules of the light modulation layer 15 is controlled by the resin interface and the liquid crystal droplets 2
Every 4th becomes irregular. As a result, the reading light 21 is repeatedly scattered and strongly reflected and refracted due to the mismatch of the refractive index between the liquid crystal droplet 24 and the transparent resin 23. On the other hand, when the writing light 20 having a sufficient intensity is incident, the electric impedance of the photoconductive layer 12 is lowered, so that part of the voltage distributed to the photoconductive layer 12 is transferred to the light modulation layer 15 side. At this time, since the size of each liquid crystal droplet 24 is uniform, the orientation of liquid crystal molecules (positive dielectric anisotropy) in each liquid crystal droplet 24 is
Align in the direction of the electric field at once. Therefore, the refractive index of the liquid crystal droplets 24 approaches the ordinary refractive index n _o, a refractive index of the transparent resin 23 n
_It is equivalent to _p . As a result, the mismatch of the refractive index is eliminated, the light modulation layer 15 is changed to transparent, and the incident read light 2
1 is reflected by the dielectric multilayer film mirror 14 and emitted. Here, if only the specularly reflected display light 22 is extracted by the optical system, an optical image of the display light 22 modulated by the writing light 20 can be obtained. The optical image thus obtained is projected onto the screen 6 via the lens 35 and the projection lens 36.

In this case, the writing light is generated by the writing optical section 1. However, as described above, when the writing light emitted from the writing light source 7 is used in a general imaging optical system,
A light source image such as a filament or an electrode of the light source is formed on the liquid crystal image forming apparatus 2, and this image is written as a writing image in the spatial light modulator 4 and causes uneven brightness.

In this embodiment, the writing light is imaged on the liquid crystal image forming apparatus 2 via the Koehler illumination optical system 8. That is, as shown in FIG. 3, the light source light of the writing light source 7 is collimated by the Koehler illumination optical system 8 and input to the liquid crystal image forming apparatus 2, so that the filament of the light source 7 is placed on the liquid crystal image forming apparatus 2. The light source image of the electrodes or electrodes is not formed. Therefore, it is possible to prevent unevenness in brightness from occurring in the written image formed on the spatial light modulator 4 via the image forming optical unit 3.

<< Experimental Example 1 >> The liquid crystal image forming apparatus 2 has a light source image.
A lens system with an F number of 4 and a focal length of 40 cm is used in order not to form an image above, and the distance between the light source 7 and the lens is 55 cm, and the distance between the lens and the liquid crystal image forming apparatus 2 is 40 cm. The experiment was done with the optical system. At this time, the ratio of the highest brightness part and the lowest brightness part of the written image was 1.4: 1 or less, and good results were obtained as uneven brightness of the written image.

Further, when a lens system having an F number of 3 to 6 is used, a brightness unevenness of 1.8: 1 or less is obtained,
It was confirmed that this value can actually secure a valid range of use.

As described above, according to this embodiment, since the image display is performed by using the Koehler illumination optical system 8, a projected image excellent in spatial uniformity can be obtained without causing uneven brightness. be able to.

FIG. 4 is a block diagram showing another embodiment of the optical writing type projection display apparatus according to the present invention.

In this embodiment, a fly-eye lens 41 is arranged between the writing light source 7 and the Kohler illumination optical system 8.

The fly-eye lens 41 is an array-shaped lens in which small lenses such as a fly's eye are arranged, and the writing light source is made multi-source by each minute lens, and light from each light source is used. The entire surface of the liquid crystal image forming apparatus 2, which is an illumination object, is illuminated and overlapped by the number of minute lenses, so that spatially uniform illumination is possible.

The surface of the fly-eye lens 41 used in this embodiment is provided with an antireflection film (not shown) having good characteristics for the spectrum of the writing light.

<< Experimental Example 2 >> An optical writing projection display device having the configuration shown in FIG. In this prototype, the fly-eye lens 41 has a length of 60 mm and a width of 6 mm.
A 0 mm, 170 mm long, f = 110 m specification was adopted.

As a result, when the number of minute lenses forming the fly-eye lens 41 is four, the brightness ratio between the highest brightness part and the lowest brightness part of the obtained written image is 100: 70 or more. , 9: 100: 90 or less, 25: 100: 95 or less, 9
Good spatial uniformity was obtained by the fly-eye lens 41 composed of one or more minute lenses.

Although the cross section of the light beam emitted from the writing light source 7 is circular, when the fly-eye lens 41 having a rectangular aspect ratio is used, the non-uniform circular light beam from the light source is a fly-eye lens. Since it is transformed into a uniform rectangular light flux by 41, the light utilization rate of the writing light source 7 can be greatly improved, and as a result, the display device can be downsized.

Furthermore, when the fly-eye lens 41 composed of the nine minute lenses is incorporated in the projection display shown in FIG. 4, the light of the writing light source is utilized as compared with the case without the fly-eye lens 41. The result is that the rate is 1.5 times or more.

When the fly-eye lens 41 having a light flux cross section of 3: 4 is used in conformity with the liquid crystal image forming apparatus 2 having an aspect ratio of 3: 4, the light utilization rate is higher than that when the fly-eye lens 41 is not used. It has more than doubled. Also, 9:16
The cross section of the light flux is 9:16 according to the liquid crystal image forming apparatus 2 of
Even when the fly eye lens 41 is used, the light utilization rate is more than double.

As described above, it was confirmed that the light utilization efficiency of the light source can be improved by adjusting the aspect ratio of the minute lenses constituting the fly-eye lens 41 to the shape of the liquid crystal image forming apparatus 2.

Further, it has been found that when the fly-eye lens 41 is used, the power of the writing light source 7 is half that in order to obtain a written image with the same light intensity as when the fly-eye lens 41 is not used. Therefore, a small light source can be used, and the entire configuration of the writing optical unit 1 can be reduced to 2/3.

FIG. 5 shows still another embodiment of the light-immersion type projection display device according to the present invention.

The feature of this embodiment is that the telecentric optical system 5 is used as the image forming optical unit 3 for forming the optical image displayed on the liquid crystal image forming apparatus 2 on the spatial light modulator 4.
1 was used.

As shown in FIG. 6, the telecentric optical system 51 is an optical system arranged so that the principal ray from the liquid crystal image forming apparatus 2 passes through the focal point of the imaging lens. When the telecentric optical system 51 is used in the image forming optical unit 3, even if the spatial light modulator 4 is moved in the optical axis direction, the size of the image written on the photoconductive layer 12 does not change. Therefore, when the telecentric optical system 51 is used, even if the spatial light modulator 4 having different thicknesses of the photoconductive layer 12 is used, the size of the written image does not differ in the thickness direction, so that the high-resolution written image is obtained. Can be modulated.

Experimental Example 3 According to the experiments conducted by the present inventors,
A projection type display (see FIG. 11) which does not use the telecentric optical system 51 of FIG. 5 but instead uses the above-mentioned normal single lens (F number = 2) to form an image-forming optical unit 3 has a thickness of 1 mm. The spatial light modulator 4 having the photoconductive layer 12 has a resolution of 10 lp / mm and a thickness of 2
The resolution of the spatial light modulator 4 having the photoconductive layer 12 of 50 μm was 25 lp / mm.

On the other hand, in the projection display device using the telecentric optical system (F number = 3.5) 51, the resolution of the spatial light modulator having the photoconductive layers 12 having different thicknesses of 1 mm and 250 μm is: Both were 50 lp / mm, and a high-resolution image display was obtained. This performance does not change even when the F-number of the telecentric optical system 51 is changed from 2 to 6,
The resolution of the displayed image was constant.

As described above, according to this embodiment, the optical image displayed on the liquid crystal image forming apparatus 2 is converted into the spatial light modulator 4.
Since the telecentric optical system 51 is used as the image forming optical unit 3 for forming an image on the optical axis, even when the spatial light modulator 4 moves in the optical axis direction, the image to be written on the photoconductive layer 12 is not changed. There is no change in size. Therefore, when the telecentric optical system 51 is used, even in the spatial light modulator 4 having different thicknesses of the photoconductive layer 12, the size of the written image does not differ in the thickness direction, so that the writing image can be modulated with high resolution. Is.

Further, in this embodiment, since the writing optical unit 1 uses the Koehler illumination optical system 8 and the fly-eye lens 41 for producing a uniform luminous flux, an image with good spatial uniformity is displayed. it can.

FIG. 7 shows still another embodiment of the optical writing type projection display device according to the present invention. The same components as those in each of the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

This embodiment is a device for displaying a full-color image, and as shown in FIG. 7, a writing optical unit 1 including a writing light source 7, a fly-eye lens 41 and a Kohler illumination optical system 8. , The light splitting unit 61 and the liquid crystal image forming devices 2G, 2 provided for each of green, red, and blue.
R, 2B, an image forming optical unit 3 having telecentric optical systems 51G, 51R, 51B provided separately for green, red, and blue, and spatial light modulators 4G, 4R provided respectively for green, red, blue. , 4B, a projection optical unit 5, and a screen 6.

The light splitting unit 61 reflects a 1/3 of the writing light input from the writing optical unit 1 and transmits a 2/3 of the writing light, and a light reflected by the split mirror 62. And a half mirror 64 that reflects half of the light transmitted through the split mirror 62 and transmits half of the light that is incident on the red liquid crystal image forming apparatus 2R. And a reflection mirror 65 that reflects the light reflected by the half mirror 64 and makes it enter the green liquid crystal image forming apparatus 2G.

On the other hand, the projection optical unit 5 includes a xenon lamp,
A white light source 31 for display including a halogen lamp, a metal halide lamp, etc., a condenser lens 33 for condensing visible light from the white light source 31, and a condenser lens 33.
The reflection mirror 34 that reflects the light condensed by the light is emitted, and the reflection light of the reflection mirror 34 is emitted as the reading light of the spatial light modulator 4, and the optical image written in the spatial light modulator 4 is incident. A lens 35 that emits as display light (reflected light) and a projection lens 36 that receives the display light emitted from the lens 35 and projects the display light onto the screen 6 are provided.

The projection optical section 5 reflects the blue light in the read light that has passed through the lens 35, and the dichroic mirror 71 that transmits other colors of light, and is reflected by the dichroic mirror 71. A reflecting mirror 7 that emits blue light as read light of the blue spatial light modulator 4B and reflects blue display light emitted from the spatial light modulator 4B toward the dichroic mirror 71.
2 and of the light transmitted through the dichroic mirror 71, the red light is transmitted and the green light is reflected, while the transmitted red light is emitted as the read light of the red spatial light modulator 4R and the spatial light The dichroic mirror 73 on which the red display light emitted from the modulator 4R is incident, and the green light reflected by the dichroic mirror 73 is emitted as the read light of the green spatial light modulator 4G, and the spatial light modulation is performed. A reflection mirror 74 that reflects the green display light emitted from the element 4G toward the dichroic mirror 73 is provided.

In the above structure, the illumination light made into a uniform light flux by the fly-eye lens 41 of the writing optical unit 1 and the Koehler illumination optical system 8 is equally divided into three in the light dividing unit 61, which are green and red, respectively. , Blue liquid crystal image forming apparatus 2
It is incident on G, 2R and 2B. The image lights from the green, red, and blue liquid crystal image forming devices 2G, 2R, 2B are
Telecentric optical system 51G, 51R, 51 for each color
An image is formed on the spatial light modulators 4G, 4R, 4B of each color via B.

On the other hand, the light source light (readout light) from the white light source
Is a dichroic mirror 71 that reflects blue light,
It is color-divided by the dichroic mirror 73 that reflects green light, and is emitted as the read light 21 of the spatial light modulators 4G, 4R, 4B of each color. The reflected lights (display lights) of the spatial light modulators 4G, 4R, 4B of the respective colors are combined by the dichroics 73, 71, and then projected onto the screen 6 by the lens 35 and the projection lens 36.

As described above, also in this embodiment, the telecentric optical systems 51G, 51R, 51B are classified by color.
Writing light into spatial light modulators 4G, 4
Since the image is formed on R and 4B, the size of each writing light image does not change with respect to the movement of each spatial light modulator 4G, 4R, and 4B in the optical axis direction, as described with reference to FIG. Registration adjustment of the projected image in full color becomes easy,
It is possible to display a high quality projected image.

As a specific example of a full-color projection display device, the spatial light modulators 4G, 4R, and 4B having the configuration of FIG. 2 are used, and a white light source 31 for display has a xenon lamp of 1 kW and a diagonal. FIG. 7 in which each 1.3-inch liquid crystal image forming apparatus 2G, 2R, 2B is incorporated.
As a result of making an experiment with a projection type display device having a configuration, it was possible to obtain a high-quality full-color image display having a light output of 2000 lumens or more and excellent spatial uniformity.

[0069]

As described above, according to the present invention, in the first and second aspects of the present invention, the Koehler illumination optical system for generating the illumination light for illuminating the liquid crystal image forming apparatus from the writing light source is provided. Therefore, the brightness unevenness of the written image is significantly reduced, and it is possible to display a high-luminance projection image that is spatially uniform and of high quality.

Further, in the invention of claim 3, the light modulating layer constituting the spatial light modulating element comprises a group consisting of a nematic liquid crystal, a cholesteric liquid crystal, a smectic liquid crystal, and a mixture of these nematic liquid crystal, cholesteric liquid crystal and smectic liquid crystal. One or more liquid crystals, or a nematic liquid crystal having a normal resin refractive index equivalent to this transparent resin in a transparent resin having a preset refractive index,
Either cholesteric liquid crystal or smectic liquid crystal,
Alternatively, a liquid crystal / resin composite in which a mixed liquid crystal of these liquid crystals is dispersed, or a liquid crystal / resin composite in which the transparent resin is dispersed in these liquid crystals is used. Combined with the adoption, it is possible to display a high-luminance projection image of higher spatial uniformity and high quality.

Further, according to the invention of claim 4, since the writing light source section has the fly-eye lens, the non-uniform luminous flux emitted from the writing light source can be converted into a rectangular uniform luminous flux, and the light utilization factor is improved. It is possible to greatly improve and, in combination with the Koehler illumination optical system, spatially uniform illumination becomes possible.

Further, in the invention of claim 5, the aspect ratio of the illumination light flux by the fly-eye lens is configured to match the aspect ratio of the liquid crystal image forming apparatus, so that the light utilization rate can be further improved.

Further, in the invention of claim 6, since the image forming optical section is constituted by the telecentric optical system,
The size of the written image formed on the photoconductive layer of the spatial light modulator does not change even when the spatial light modulator moves in the optical axis direction. Therefore, when this telecentric optical system is used, even in a spatial light modulator having different thicknesses of the photoconductive layer, the size of the written image does not differ in the thickness direction, so that it is possible to modulate the written image with high resolution.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an optical writing type projection display device according to the present invention.

FIG. 2 is a configuration diagram showing an example of a spatial light modulator that is a component of the optical writing projection display device according to the present invention.

FIG. 3 is an explanatory diagram showing a function and effect of the optical writing projection display device shown in FIG.

FIG. 4 is a configuration diagram showing another embodiment of the optical writing type projection display device according to the present invention.

FIG. 5 is a configuration diagram showing still another embodiment of the optical writing projection display device according to the present invention.

FIG. 6 is an explanatory diagram showing the operational effects of the optical writing projection display device shown in FIG.

FIG. 7 is a configuration diagram showing still another embodiment of the optical writing projection display device according to the present invention.

FIG. 8 is a configuration diagram showing an example of a conventional optical writing projection display device.

FIG. 9 is a configuration diagram showing an example of a spatial light modulator that is a component of a conventional optical writing projection display device.

FIG. 10 is an explanatory diagram showing a function and effect of the conventional optical writing projection display device shown in FIG.

FIG. 11 is an explanatory diagram showing a function and effect of the conventional optical writing projection display device shown in FIG.

[Explanation of symbols]

1 Writing Optical Section 2, 2B, 2G, 2R Liquid Crystal Image Forming Device 3 Imaging Optical Section 4, 4B, 4G, 4R Spatial Light Modulation Element 5 Projection Optical Section 6 Screen 7 Writing Light Source 8 Koehler Illumination Optical System 9 Imaging Lens 11 First transparent electrode 12 Photoconductive layer 13 Light absorption layer 14 Dielectric multilayer film mirror 15 Light modulation layer 16 Second transparent electrode 17 Transparent substrate 18 Lead wire 19 AC power supply for driving 20 Write light 21 Read light 31 White light source 32 Bandpass Filter 33 Condensing lens 34 Reflecting mirror 35 Lens 36 Projecting lens 41 Fly-eye lens 51, 51B, 51G, 51R Telecentric optical system 61 Optical path separating unit 62 Split mirror 63, 65 Reflecting mirror 64 Half mirror 71, 73 Dichroic mirror 72, 74 Reflective mirror

Front page continuation (72) Inventor Hiroshi Kikuchi 1-10-11 Kinuta, Setagaya-ku, Tokyo Inside the Japan Broadcasting Corporation Broadcasting Technology Laboratory (72) Inventor Hideo Fujikake 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan (72) Inventor Takanori Fujii, 1-10-11 Kinuta, Setagaya-ku, Tokyo Inside Broadcasting Technology Institute, Japan Broadcasting Corporation

Claims (6)

[Claims] 1. A first transparent electrode, a photoconductive layer laminated on the first transparent electrode, the impedance of which changes according to the intensity of incident light, and a light absorption layer laminated on the photoconductive layer.
A dielectric multilayer mirror that is laminated on the light absorbing layer and reflects all or part of the visible light spectrum, a light modulating layer that is laminated on the dielectric multilayer mirror, and a first multilayer that is laminated on the light modulating layer. A spatial light modulator including at least two transparent electrodes and driven by an AC voltage applied between the first transparent electrode and the second transparent electrode; and a visible light source, A projection optical unit that irradiates visible light as reading light and projects reflected light of the spatial light modulator with respect to the reading light onto the screen as display light, a liquid crystal image forming apparatus for displaying an input image, and the spatial light. Writing comprising a writing light source having a spectrum sensitive to the photoconductive layer of the modulator and a Kohler illumination optical system for generating illumination light for illuminating the liquid crystal image forming apparatus from the writing light source An optical unit, the optical writing type projection display device comprising an imaging optical unit for focusing the light image on the photoconductive layer of the spatial light modulator, in that it consists of the liquid crystal image forming apparatus. 2. A first transparent electrode, a photoconductive layer laminated on the first transparent electrode, the impedance of which changes according to the intensity of incident light, and a light absorption layer laminated on the photoconductive layer.
A dielectric multilayer mirror that is laminated on the light absorbing layer and reflects all or part of the visible light spectrum, a light modulating layer that is laminated on the dielectric multilayer mirror, and a first multilayer that is laminated on the light modulating layer. A spatial light modulation element for each of blue, green and red that is driven by an AC voltage applied between the first transparent electrode and the second transparent electrode, and a visible light source. , The visible light from the visible light source is separated into blue, green and red lights, which are applied to the respective spatial light modulators as readout light, and the reflected light from the respective spatial light modulators with respect to the readout light is combined. And a projection optical section for projecting as display light on a screen, separate liquid crystal image forming apparatuses for forming blue, green and red input images, and writing having a spectrum sensitive to each photoconductive layer. A writing optical unit including a light source and a Kohler illumination optical system that generates illumination light that illuminates each of the liquid crystal image forming apparatuses from the writing light source, and the illumination light emitted from the writing optical unit is divided into three parts. A division unit including an optical element that emits light to each liquid crystal image forming apparatus, and a separate connection for blue, green, and red that forms an optical image of each liquid crystal image forming apparatus on the photoconductive layer of each spatial light modulation element. An optical writing projection display device comprising an image optical unit. 3. The optical writing projection display device according to claim 1, wherein the light modulation layer forming the spatial light modulator is a nematic liquid crystal, a cholesteric liquid crystal, a smectic liquid crystal, a nematic liquid crystal of these, or a cholesteric liquid crystal. , One or more liquid crystals of a group composed of a mixture of smectic liquid crystals, or a nematic liquid crystal, a cholesteric liquid crystal having a transparent resin having a preset refractive index and an ordinary light refractive index equivalent to this transparent resin, A liquid crystal / resin composite in which any one of smectic liquid crystals or a mixed liquid crystal of these liquid crystals is dispersed, or a liquid crystal / resin composite in which the transparent resin is dispersed in these liquid crystals. Writable projection display device. 4. The optical writing projection display device according to claim 1, wherein the writing optical unit converts a nonuniform light flux emitted from a writing light source into a rectangular uniform light flux. An optical writing projection display device having an eye lens. 5. The optical writing projection display device according to claim 4, wherein an aspect ratio of an illumination light flux by the fly-eye lens matches an aspect ratio of the liquid crystal image forming apparatus. Type display device. 6. The optical writing projection display device according to claim 1, wherein the image forming optical unit is composed of a telecentric optical system. Optical writing projection display device.