JPH086065A - Color image output device - Google Patents

Abstract

PURPOSE:To enable size reduction, price reduction, and picture quality improvement by the use of simple structure by providing a time-division color separating means. CONSTITUTION:An input image medium 602 is irradiated with the light from a light source 601 for writing and luminous flux of an input image is subjected to time-division through a time-division color separating means 604 for writing, so that pieces of luminous flux of input images of R, G, and B components appear in sequence. Those input images irradiate the write surface of a spatial optical modulator 605 and is modulated to appear on the read surface. The light from a light source 606 for reading, on the other hand, is divided by time through a time-vision color separating means 607 for reading and pieces of luminous flux of R, G, and B components appear in order and are reflected through the modulated input image on the read surface of the spatial optical modulator 605, so that the input images of the respective color components are read out. At this time, a modulation control circuit 610 synchronously control the modulation characteristics of the spatial optical modulator 605 and the time-vision color separating means 604 and 607. Then the input images of the three colors are outputted on an output screen 609 through an output optical system 608.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to small objects, documents,
The present invention relates to a color image output device that takes in image information such as a negative or reversal photographic film, a photographic print, an exposure mask pattern, and outputs the image information. The output referred to here is a case where an image for visual observation as a display device is directly displayed on a screen or the like, a case where an image is outputted onto some medium such as photographic paper or photographic film for making a hard copy, and further, This includes the case where image information is transmitted as an input signal to an image processing device / measuring device connected to the output side.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 8, there has already been a device for displaying image information recorded on a transparent object such as a reversal photographic film or an OHP sheet by magnifying and projecting it for easy viewing by illuminating it with transmission. Widely used. Negative photographic enlargers for printing magnified projection images directly on photographic paper are also widely known. A mask exposure apparatus or the like for exposing a mask pattern to a semiconductor wafer or the like has almost the same configuration, although there are differences in the properties of the object, the wavelength of light used, and the like. There is also an apparatus that magnifies and projects information recorded on an opaque object such as a small object, a document, or a photographic print by using reflective illumination.

Further, as shown in FIG. 9, when capturing image information, the image information is converted into video information once scanned by using a scanning type image device such as an image pickup tube or a CCD, and this is converted into a CRT or a liquid crystal display panel. A device for inputting and displaying on such a display device is already commercially available.

Further, in order to obtain a high-brightness display which is enlarged and projected as shown in FIG. 10, the target image is once inputted to the spatial light modulator, and the image is read out by using a strong light source. There is also a device for optically amplifying and displaying, and in particular, a device using an optical writing type liquid crystal spatial light modulator is commercially available.

A conventional example of a device for optically amplifying the output target image through a spatial light modulator to display a color image will be described with reference to FIG. The light flux from the writing light source 151 illuminates the transparent input image medium 150 carrying the target image via the parallel optical system 152. The input image after being transmitted through the medium is transmitted through the input image forming system 102, and then, by the dichroic mirrors 306a and 306b and the reflecting mirror 306c which form the color separation optical system, the three primary colors Red, Green, B.
(hereinafter, Red is R, Green is G, and Blue is B), and is separated into three color light beams, and the R, G, and B are separated.
Independently for the writing light flux of, the three light writing type spatial light modulators 103a, 103b, and 103c are separately imaged on the writing surfaces. Then, these input images are modulated by the optical writing type spatial light modulator 103,
It appears on the read surface of the optical write type spatial light modulator 103.

Here, the light flux from the reading light source 153 passes through the parallel optical system 154, and the dichroic mirrors 307a and 307b and the reflecting mirror 307 which constitute the color separation optical system.
Polarization beam splitter 1
The read light fluxes of R, G, and B are separately irradiated via 55a, 155b, and 155c to the three optical writing type spatial light modulators 103a, 103b, and 103c that are independently prepared. And the optical writing type spatial light modulator 103
The modulated images on the reading surfaces of a, 103b, and 103 are read by the color-separated light fluxes of the reading light sources, and are output by the output projection lens 170.
The composite image is formed on the image pickup device 56 and is formed as a final color output image of the entire apparatus.

[0007]

However, in the conventional magnifying projector with simple transmissive or reflective illumination, the light illuminating the target object is used as it is for display, which is sufficient for high-quality image display. It had a drawback that the illuminance could not be obtained. For example, in a slide projector, since the slide film is deteriorated and deformed by heat, the light intensity for irradiating it is limited. Also in the stereoscopic projector, when the reflectance of the object is low or the reflecting surface is a mirror surface, most of the illumination light is absorbed or reflected in a direction other than the reading window of the display device. In addition, the light intensity input to the display device is much lower than the light intensity actually applied. In such a case, since the brightness of the displayed image becomes low, it is impossible to realize the high brightness display which should be obtained by using a strong illumination light source.

In an apparatus using a scanning type image device such as an image pickup tube or CCD for taking in image information as shown in FIG. 9, an image display of considerably high brightness is realized depending on the quality of CRT used for display. It is also possible to carry out enlarged projection with a powerful light source in combination with the optical amplification function of the spatial light modulator, and it is considered that the above-mentioned drawbacks have been greatly improved. However, when a scanning type image device such as an image pickup tube or CCD is used, in the direction orthogonal to the scanning line, a frequency component higher than a certain spatial frequency determined by the interval between the scanning lines is determined by the Nyquist sampling theorem. The image information is lost when the original image information is captured. Even in the direction parallel to the scanning line, in the CCD, a component having a certain spatial frequency or more is similarly lost due to the limitation coming from the pixels of the image pickup element, and even if an image pickup tube is used, a video signal processing circuit that comes after that. However, there is a serious drawback that spatial frequency components above a certain level are lost due to the band limitation.

Further, an apparatus for optically amplifying an output target image as shown in FIG. 10 through a spatial light modulator and displaying the image has a powerful light source for display and an optical amplification function by the spatial light modulator. Therefore, it is possible to obtain a high-brightness display image while overcoming the above drawbacks. However, the color separation means in the writing part to the spatial light modulator which is the input optical system and the reading part to the spatial light modulator which is the output optical system are spatially divided for each color. The inside of the device is composed of many optical components. Therefore, the cost of the apparatus becomes very high, and the size of the apparatus main body becomes large. Further, since the images of the respective color components to be finally output are synthesized by the optical system, there is a problem that the color shift occurs due to the influence of the aberration of the optical system and the image quality is deteriorated.

Therefore, in order to solve such a conventional problem, an object of the present invention is to provide a spatial light modulator having an optical amplifying function inside a color image output device.
Obtain a bright output image. By avoiding conversion of image information into electric scanning signals and outputting as light information, loss of high frequency components is avoided. Further, by providing the time-division color separation means, it is possible to realize the biggest problems of the conventional color image output device such as miniaturization, cost reduction and high image quality with a simple structure.

[0011]

In order to solve the above-mentioned problems, the present invention relates to a spatial light modulator and an optical system for writing an input target image on a writing surface of the spatial light modulator (hereinafter, referred to as an optical system).
This is called an input optical system), an optical system for forming an image on the reading surface of the spatial light modulator on a final output surface (hereinafter referred to as an output optical system), and a drive. A color image output device including a circuit, wherein the input optical system is a first time-division device for color-separating color information of an output target image into three colors, and further time-divisionally outputting the color-separated color information. Color separation means, and second time division color division means for reading into the output optical system as the same color information as the color information written in the spatial light modulator by the first time division color separation means. And a modulation control circuit for synchronously controlling the modulation characteristics of the first time division color separation means, the second time division color separation means, and the spatial light modulator in the drive circuit. As a result, high brightness and high image quality can be ensured while achieving downsizing and cost reduction. It was so.

[0012]

In the color image output device configured as described above, a high-brightness output image can be obtained by the optical amplification action of the spatial light modulator, and the optical input signal can be output as it is as an optical output signal. . Furthermore, for a color information of three colors, a single processing system is used in a time-division manner without providing a dedicated input optical system or output optical system, a spatial light modulator, etc., and a color image is obtained through the same optical system. Can be output. For example, by repeatedly outputting three-color output images such as R → G → B → R → G → ..., and setting the repetition frequency sufficiently high with respect to the color time response of each time of the naked eye The three colors are superposed, and a color image can be output.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. First of all, FIG. 1 is a block diagram showing the basic configuration of an image output apparatus using a spatial light modulator according to the present invention.

The light from the writing light source 601 is collimated and intensity-uniformized by an optical system, and then irradiates a transparent input image medium 602 carrying a target image. The light flux of the input image after passing through the medium is time-divided by the time-division color separation unit 604 for writing after passing through the input image forming system 603, and the input image of the R component, G component, and B component is obtained. Light flux appears in sequence. Then, these input images are irradiated on the writing surface of the spatial light modulator 605, and after being modulated, appear on the reading surface of the spatial light modulator 605.

Here, the light from the reading light source 606 is collimated and made uniform in intensity by the optical system and then time-divided by the reading time-division color separation means 607 to obtain R component, G component, The B component luminous flux appears in sequence. Then, the light flux of the reading light source 606 that has passed through the reading time-division color separation means 607 is reflected via the modulated input image on the reading surface of the spatial light modulator 605 to read the input image of each color component. At this time, the modulation control circuit 604 needs to synchronously control the modulation characteristics of the spatial light modulator 605 and the write time-division color separation means 604 and the read time-division color separation means 607.

The sequentially read three-color input images finally appear on the output image plane 609 via the output optical system 608. If the repetition frequency is sufficiently high, the visually perceived image is a color image after composition. Next, an example of the spatial light modulator used in this embodiment will be described with reference to the drawings. As the spatial light modulator that can be used in the present invention, several kinds such as one using an electro-optic crystal can be considered, but the structure of the optical writing type liquid crystal spatial light modulator will be described below. As shown in FIG. 11, the transparent substrates 206a and 206b such as glass and plastic for holding the liquid crystal molecules have transparent electrode layers 20 on their surfaces.
7a and 207b, and alignment film layers 208a and 208b, which are obtained by applying a vertically aligned polyimide film and then rubbing the surface of the film with a cloth such as velvet with uniform tips. The transparent substrates 206a and 206b have alignment layers 208a and 20b.
The 8b side is made to face each other by controlling the gap via the spacer 213, and holds the nematic liquid crystal 211 having a negative dielectric anisotropy. In addition, a photoconductive layer 209 is provided on the transparent electrode layer 207a on the light writing side, and an alignment film layer 208a.
And a non-reflective coating 212a, 212b is formed on the cell outer surfaces of the writing-side transparent substrate 206a and the reading-side transparent substrate 206b. The photoconductive layer 209 includes i-type, pi-type, or pin-type hydrogenated amorphous silicon, ZnSe, CdSe, or C.
A chalcogenide photoconductor such as dTeSe, or an organic photoconductor such as vanadyl phthalocyanine can be used.

Further, the photoconductive layer 209 and the alignment film layer 208a.
A dielectric mirror 210 is laminated between and.
The dielectric mirror 210 is formed by alternately laminating a λ / 4 film, which is a high refractive index film made of silicon or a compound of silicon and germanium, and a λ / 4 film, which is a low refractive index oxide such as silicon dioxide or magnesium fluoride. A light-reflecting layer with a high light-shielding structure, a λ / 4 film of a high-refractive-index oxide such as titanium oxide or zirconium oxide, and a λ / 4 film of a low-refractive-index oxide such as silicon dioxide or magnesium fluoride are alternated The high reflection layer having a laminated structure is sequentially laminated from the photoconductor 209 side. In the following explanation,
The interface between the transparent electrode 207a and the photoconductive layer 209 is the writing surface,
The surface formed by the nematic liquid crystal 211 will be referred to as a reading surface.

Needless to say, a transparent substrate having an optical transmission anisotropy such as an optical fiber plate may be used as the transparent substrate 206a. In the optical writing type spatial light modulator having the above structure, the nematic liquid crystal 21
In No. 1, the liquid crystal molecules are initially aligned with an inclination of about 0.3 to 5 degrees with respect to the perpendicular to the surfaces of the alignment film layers 208a and 208b. That is, when no electric field is applied to the nematic liquid crystal 211, the nematic liquid crystal 211 is aligned with the liquid crystal molecules inclined by about 0.3 to 5 degrees with respect to the perpendicular of the planes of the alignment film layers 208a and 208b. . The optical writing type spatial light modulator shown in FIG.
A bipolar pulse voltage as shown in (a) is applied. At that time, when the writing light 108 is irradiated from the transparent substrate 206a side in FIG. 11, the photoconductor 2 in the portion irradiated with the writing light 108 is irradiated.
Since the impedance of 09 is lowered about 1000 times or more, most of the effective value of the bipolar pulse voltage is applied to the nematic liquid crystal 211 having a negative dielectric anisotropy. Then, the liquid crystal molecules to which the effective value of the bipolar pulse voltage is applied are aligned in the alignment film layer 208 corresponding to the effective value.
Since the inclination angle of the a and 208b planes with respect to the perpendicular is large, a corresponding birefringence change occurs in the nematic liquid crystal 211 in the portion irradiated with the writing light 108. Therefore, the polarization element which irradiates the reading light 109 polarized in a specific direction from the reading side of the optical writing type spatial light modulator and has a polarization direction perpendicular to (parallel to) the polarization direction of the reading light 109. When the reflected light of the reading light 109 from the optical writing type liquid crystal spatial light modulator is detected via, a reading image in which the portion irradiated with the writing light 108 is positive (negative) is obtained.

At this time, the amplitude of the drive voltage generated in the optical modulation characteristic control circuit 105 is made smaller (or larger) as shown in FIG. 2B, or the frequency of the drive voltage waveform is set as shown in FIG.
By making it large (or small) as shown in (c), it is possible to change the brightness, contrast and resolution of the read image, and to perform positive / negative inversion. The drive voltage applied at this time is limited by the constituent film material and film thickness of the optical writing type liquid crystal spatial light modulator, but the amplitude is 8 to 20 V and the frequency is 0.5 to 10 kHz.
Often within the range.

As the drive voltage waveform applied to the optical writing type liquid crystal spatial light modulator, in addition to the waveform shown in FIG. 2, a periodic voltage waveform such as a sine waveform or a sawtooth waveform is applied. It goes without saying that it is okay. [First Embodiment] A first embodiment of the present invention will be described.

FIG. 3 is an explanatory diagram showing the basic structure of the first embodiment. In FIG. 3, the spatial light modulator is the optical writing type liquid crystal spatial light modulator 103 shown above. The input optical system is a writing light source 151 and a parallel optical system 152 for collimating the light from the writing light source and making the light intensity uniform and the parallel optical system 1.
It is composed of an input image forming system 102 for forming an image of a light beam from the writing light source 151 via 52 on the writing surface of the optical writing type liquid crystal spatial light modulator 103. Further, the output optical system is the reading light source 1.
53 and the parallel optical system 154 for making the light from the reading light source 153 parallel and making the light intensity uniform.
A polarization beam splitter (hereinafter referred to as PBS) 155 that reflects the light flux of the reading light source 153 via 4 and transmits the light flux after reading, and the light flux of the output image that has passed through the PBS 155 is formed on the output image plane 156. Output projection lens 170. The writing color separation filter 160 which is the first time-division color separation means and the reading color separation filter 161 which is the second color separation means have the same structure and are composed of three kinds of optical filters.

First, an input optical system for forming an output target image of this apparatus on the writing surface of the spatial light modulator will be described. As the writing light source 151, a white light source such as a metal halide lamp or a halogen lamp that outputs visible light in a wide band is used. The light flux from the writing light source 151 is a parallel optical system (here, the elliptical mirror 152-1 and the collimator lens 1).
52-2) to form a light flux that is substantially parallel and has a uniform intensity distribution, and irradiates the transparent input image medium 150 that carries the target image. The light flux of the input image that has passed through this medium is input to the writing color separation filter 160 via the input image forming system 102.

The writing color separation filter 160 is disc-shaped, and is arranged such that the disc surface is perpendicular to the optical axis of the light flux of the input image. The color separation filter 160 for writing, for example, red, green, and blue while time-sharing white light.
(Hereinafter, Red is R, Green is G, and Blue is B.) It is to separate light into three primary colors. Each of the three primary colors is separated into three types of optical filters (only the R component is transmitted). The following filters are R filters, G filters
A filter that transmits only the component is referred to as a G filter, and a filter that transmits only the B component is hereinafter referred to as a B filter), and each filter is divided into three fan-shaped parts on a disk, and the R filter, the G filter, and the B filter. Are arranged in sequence.

Further, the writing color separation filter 160 is driven by a pulse motor as a driving source, and is driven to rotate counterclockwise around the center of the circle by linear motion or gear wheel train or belt drive as seen from the input direction of the light beam. Further, the rotation axis of the circular center is arranged so that each of the three types of filters is positioned vertically and sequentially with respect to the optical axis of the light flux of the input image by the rotation of the writing color separation filter 160. is there.

The light flux of the input image is converted into the color separation filter 16 for writing.
By entering the R filter, the G filter, or the B filter of 0, only the color component of one color is separated and passed from the light flux of the input image. Here, it is assumed that the R component has passed. The R component light flux thus decomposed forms an image on the writing surface of the optical writing type liquid crystal spatial light modulator 103.

In FIG. 3, the writing color separation filter 160 is arranged between the input image forming system 102 and the spatial light modulator 103. However, between the input image medium 150 and the input image forming system 102, or the input connection. It may be arranged in the image system 102. Further, since the writing color separation filter 160 uses three types of filters, it is divided into three equal parts in the present embodiment, but it is not particularly limited to this, and the number of filters, the order of arrangement, and the area of each filter. The ratio can be changed according to the purpose. For example, regarding the number of filters, three types of filters are the color separation filter 1 for writing.
Any number of filters may be used as long as they are arranged so as to be successively and sequentially positioned on the optical axis of the light flux of the input image by the rotation of 60. Further, the arrangement of each filter is permuted 3
It suffices that the three filters of the R filter, the G filter, and the B filter are prepared, and the order is not particularly limited.
Further, the area ratio of each filter may be any structure as long as it can ensure a cross-sectional area of the light beam by the input image or more. For example, the area of the B filter having a low transmittance is twice as large as that of the R filter or the G filter, and the writing By continuously rotating the color separation filter 160 for light, the transmission amount of the light flux of B is changed to R and G.
Can be doubled.

Next, an output optical system for finally forming an image on the output image plane of the written image written on the writing surface of the spatial light modulator in the above steps of the present apparatus will be described. The reading light source 153 may be an LED or the like which is a narrow band light source such as red, green or blue, or may be a white light source which outputs a wide band visible light such as a metal halide lamp, a halogen lamp or a xenon lamp. Further, a coherent light source such as a semiconductor laser may be used. In this embodiment, an example using a white light source will be described.

The light beam from the reading light source 153 is converted into a substantially parallel light beam having a uniform intensity distribution by the parallel optical system 154 and is input to the reading color separation filter 161. Since the reading color separation filter 161 has the same structure as that of the writing color separation filter 160, the description of the structure of the reading color separation filter 161 is omitted here. Further, the read color separation filter 161 has the same arrangement of the R filter, G filter, and B filter as seen from the input side of the optical axis, and is the same as the writing color separation filter 160, and further, the rotation direction seen from the input side of the light flux. Is also equivalent.

The reading color separation filter 161 shares a drive source with the writing color separation filter 160 and is driven by a gear train or a belt drive. Further, a filter of the same color as the writing color separation filter 160 is used. The structure is such that it faces the optical axis at almost the same time. Therefore, at this time, the light flux of the reading light source 153 that has passed through the parallel optical system 154 is input to the R filter similarly to the light flux of the writing light source 151. Therefore, only the R component of the light flux of the reading light source 153 is selected and transmitted, and the same process is repeated for G and B thereafter.

In FIG. 3, the reading color separation filter 161 is arranged between the parallel optical system 154 and the PBS 155. However, between the reading light source 153 and the parallel optical system 154, or from the PBS 155 to the optical writing type liquid crystal. Spatial light modulator 10
3 or between the PBS 155 and the projection lens system 170 or between the projection lens system 170 and the output image plane 156.

The luminous flux input to the PBS 155 is P
The S-polarized light flux separated into the polarized light and the S-polarized light and separated / reflected illuminates the reading surface of the optical writing type liquid crystal spatial light modulator 103. Although only the S-polarized light separated by the PBS 155 is used in FIG. 3, it goes without saying that an optical system that uses a P-polarized light flux may be used. In the optical writing type liquid crystal spatial light modulator 103, the alignment direction of the liquid crystal and the direction of the optical axis of the electro-optical final are adjusted in advance so that the phase is modulated when the S-polarized light flux is applied to the reading surface. ing.

As described above, the optical writing type liquid crystal spatial light modulator 103 is irradiated with the image and the optical writing type liquid crystal spatial light modulator 103 is modulated in accordance with the modulation characteristic of the optical writing type liquid crystal spatial light modulator 103. The S-polarized light flux applied to the reading surface of the spatial light modulator 103 is phase-modulated and reflected. The light flux reflected by the reading surface is converted from phase modulation into intensity modulation by passing through the PBS 155 again. The intensity-modulated light beam is imaged on the output image plane 156 such as a projection screen by the output projection lens system 170. Here, for the output projection lens system 170, the optical writing type liquid crystal spatial light modulator 103 is used.
The reading surface and the output image surface 156 are in the relationship of the image forming position. In the case of a projector or the like, the output image plane 156 is a screen, and in the case of a copying machine or the like, the output image plane 156 is a screen.
Is the image plane of the printing mechanism.

In the above embodiment, the PBS 155 fulfills the three functions of (1) separation of the optical path of the read incident light and reflected light, (2) polarization of the read incident light, and (3) analysis of the read reflected light. However, it is also possible to assign these functions to different component parts. FIG. 6 is a configuration diagram showing the configuration of the embodiment in such a case. 6 (a) uses a half mirror for the function of (1) and one polarizing plate for the functions of (2) and (3), and FIG. 6 (b) shows the functions of (2) and (3). This is a case where one polarizing plate is also used. In FIG. 6A, the substantially parallel light flux from the reading light source is the polarizer 158a.
The light beam that has been polarized by is incident on the half mirror 157, and is split into two light beams by the half mirror 157. One of the branched light beams illuminates the reading surface of the optical writing type liquid crystal spatial light modulator 103. The light beam reflected by the reading surface of the optical writing type liquid crystal spatial light modulator 103 and phase-modulated is branched again into two light beams by the half mirror 157, and one light beam is converted into intensity modulation by the analyzer 158b. To be done. With the above configuration, the same operation as the configuration shown in FIG. 5 is possible. Further, as shown in FIG. 6B, a polarizer 158a
It goes without saying that a single polarizing plate 158c may also serve as the detector 158b and the detector 158b may be arranged in the optical path between the half mirror 157 and the optical writing type liquid crystal spatial light modulator 103.

Next, the writing color separation filter 160, the reading color separation filter 161, and the optical writing type liquid crystal spatial light modulator 10.
A driving method of the modulation control circuit for synchronously controlling the modulation characteristic of No. 3 will be described in detail with reference to the timing chart diagram shown in FIG. The clock 401 is a signal that serves as a reference for the operation of the image output apparatus of this embodiment.

The drive clock 402 is a signal synchronized with the clock 401 and is input to the pulse motor which is the drive source of the writing color separation filter 160. The applied voltage 403 is a drive voltage waveform composed of a positive voltage pulse and a negative voltage pulse, and indicates the voltage applied to the spatial light modulator. The optical response 404 shows the reaction speed of the photoconductive layer of the spatial light modulator corresponding to the applied voltage 403, that is, a state where light of a constant intensity is incident on the photoconductive layer and the input image appears on the read surface.

The spatial light modulator is assumed to write an image when a negative voltage is applied by an applied voltage 403 and erase the image when a positive voltage is applied. First, the drive clock 40
2 is input to a pulse motor (not shown), and at the same time, a positive voltage is applied to the spatial light modulator. Two pulses of the drive clock 402 are input to the pulse motor, which causes the writing color separation filter 160 to rotate by a predetermined amount.
Here, the R filter is located in the light flux of the input image and is stopped for a minute time t ₁ . Further, after the R filter is positioned at the light flux of the input image, a negative voltage is applied to the spatial light modulator with a slight delay t ₂ and the R component that has passed through the writing color separation filter 160 (here, the R filter). Input image is written on the writing surface. At this time, the input operation causes the input image to appear on the read surface at a reaction speed as shown by the R output 405.

In the reading portion, the reading color separation filter 161 is the writing color separation filter 16 as described above.
0 and the drive source are shared, and the drive system is mechanically connected to rotate substantially in synchronization, so that the read color separation filter 161 performs the same operation as the write color separation filter 160. Therefore, the light flux of the R component of the reading light source that has passed through the reading color separation filter 161 (here, the R filter) is read by the spatial light modulator at the same timing as the writing color separation filter 160 for a minute time t _1. Illuminate the surface. The irradiated R component read light is reflected by the dielectric mirror in the spatial light modulator via the read surface, and the R component input image corresponding to the light intensity of the read light source 153 is output through the output optical system. It

After the negative voltage is applied to the spatial light modulator, a small time t ₃ elapses, and when the writing of the R component on the writing surface to the input image is completed, a positive voltage is applied to the spatial light modulator to input it. The image is erased. At the same time as the negative voltage is applied to the spatial light modulator in the erasing operation, two pulses of the drive clock 402 are input to the pulse motor again, and the writing color separation filter 160 is rotated by a predetermined amount. Here, the G filter is located in the light flux of the input image, and the minute time t ₁
Just stop. Further, after the G filter is positioned in the light flux of the input image, a negative voltage is applied to the spatial light modulator with a slight delay of t ₂ and the G component passed through the writing color separation filter 160 (here, G filter). Input image is written on the writing surface. At this time, the writing operation causes the input image to appear on the reading surface at a reaction speed as shown by the G output 406.

In the reading portion, the reading color separation filter 161 is the writing color separation filter 16 as described above.
0 and the drive source are shared, and the drive system is mechanically connected to rotate substantially in synchronization, so that the read color separation filter 161 performs the same operation as the write color separation filter 160. Therefore, the light flux of the R component of the reading light source that has passed through the reading color separation filter 161 (here, the G filter) is read by the spatial light modulator at the same timing as the writing color separation filter 160 for a minute time t _1. Illuminate the surface. The irradiated read-out light of the G component is reflected by the dielectric mirror in the spatial light modulator via the read surface, and the input image of the G component according to the light intensity of the read light source is output through the output optical system. .

After the negative voltage is applied to the spatial light modulator, when a minute time t ₃ has elapsed and the writing of the G component on the writing surface to the input image is completed, a positive voltage is applied to the spatial light modulator to input The image is erased. The writing / reading operation of the B component is the same as that of the R component and the G component, and therefore will be omitted.

The above operation is sequentially repeated for each filter. At this time, the drive clock 402 is a pulse required to rotate the writing color separation filter 160 and is not limited to two pulses. In the driving method of the writing color separation filter 160, the optical writing liquid crystal spatial light modulator 103, and the reading color separation filter 161, the color separation filters are driven intermittently. If the incident time of the writing light by the R filter to the spatial light modulator 103 is set longer than the writing time of the R color of the optical writing type liquid crystal spatial light modulator 103, for example, the color separation filter is continuously rotated. However, it goes without saying that the same effect can be obtained. Furthermore, for example, the writing color separation filter 160 is intermittently driven and the reading color separation filter 161 is continuously driven, or the writing color separation filter 160 is continuously driven and the reading color separation filter 161 is intermittently driven. I don't mind.

As described above, the writing color separation filter 16
The rotation time of 0 divides the irradiation time of RGB three colors. As a result, the input images separated into the three colors are successively formed on the writing surface of the optical writing type liquid crystal spatial light modulator 103. Further, the input image obtained by color separation of these three colors is the driving circuit 10
The desired modulation for each color is received by the optical modulation characteristic synchronization control circuit 122 and the modulator included in 4 and sequentially appear on the reading surface of the spatial light modulator according to the time zone. The image subjected to the desired modulation by the spatial light modulator selects a color component by rotating the reading color separation filter 161 similarly to the writing color separation filter 160, and is read by the reading light of the selected color component. Then, it is formed on the output image plane 156 as a final output image through the output projection lens system. This output image is
Although the image is color-modulated for each color component, if the repetition frequency of the time-divided time zone of these three colors is sufficiently high with respect to the color time response of the naked eye, the three colors are sensuously superimposed. It will have the same effect as. That is, the actual color composition is
This is done with the sense of the person who sees the output, and the visual image is a color image after composition. In addition, by controlling the light modulation characteristics of each of the three colors independently for each color separated while time-sharing, after writing the input image, negative / positive inversion, contrast / brightness, and other color balance It is possible to correct the color tone called. Therefore, variations in the light intensity at the time of writing each color and the sensitivity of the optical writing type liquid crystal spatial light modulator for each color can be dealt with by the above-mentioned correction means.

[Second Embodiment] A second embodiment of the present invention will be described. FIG. 5 is an explanatory diagram showing the basic configuration of the first embodiment. In FIG. 5, the spatial light modulator is the above-described optical writing type liquid crystal spatial light modulator 103. The input optical system outputs a light beam from the writing light source 151 and a light beam from the writing light source 151 via the parallel optical system 152 for collimating the light from the writing light source and making the light intensity uniform. It is composed of an input image forming system 102 for forming an image on the writing surface of the optical writing type liquid crystal spatial light modulator 103. The output optical system includes a reading light source 153, a parallel optical system 154 for making the light from the reading light source 153 parallel, and a uniform light intensity, and the parallel optical system 1.
PBS 155 that reflects the light flux of the reading light source 153 via 54 and transmits the light flux after reading, and the PBS
It is composed of an output projection lens 170 that forms the light flux of the output image that has passed through 155 on the output image plane 156. Color separation polygon mirror 162 for writing which is a first time division color separation means
The read color separation polygon mirror 163, which is the second color separation means, has the same structure and is composed of three types of reflection type optical filters.

First, an input optical system for forming an output target image of this apparatus on the writing surface of the spatial light modulator will be described. As shown in FIG. 5, the basic structure of the second embodiment is almost the same as that of the first embodiment, and polygon mirrors are arranged at the positions of the writing color separation filter 160 and the reading color separation filter 161.

In FIG. 5, a white light source is used as the writing light source 151 as in the first embodiment. The light flux from the writing light source 151 is made into a light flux that is substantially parallel and has a uniform intensity distribution by the parallel optical system 152, and illuminates the transparent input image medium 150 that bears the target image. The light flux of the input image that appears on the surface of the medium after passing through the medium enters the writing color separation polygon mirror 162 via the input image forming system 102.

The writing polygon mirror separates the white light into the three primary colors of R, G, and B while rotating it by rotation, and the plane portion reflects the respective components of R, G, and B. An optical filter that uses three types of reflective dichroic mirrors (hereinafter, a dichroic mirror that reflects the R component is an R mirror, a dichroic mirror that reflects only the G component is a G mirror, and a dichroic mirror that reflects only the B component is a B mirror. It is a mirror) and the like.

The polygon mirror used in this embodiment is composed of two R mirrors, two G mirrors, and two B mirrors, for a total of six surfaces, each surface being arranged perpendicular to the light flux of image information. There is. Further, the writing polygon is rotationally driven in the direction of arrow A about the central axis by linear motion or gear wheel train or belt drive using a pulse motor as a drive source. In FIG. 5, for example, the R mirror is positioned at an angle of + 135 ° (the counterclockwise direction is + and the clockwise direction is − with respect to the optical axis of the writing light) with respect to the light flux of image information. Therefore, when the light flux of image information is input to the R mirror surface, only the R component of the light flux of the writing light is reflected and refracted in the + 90 ° direction (this angle is the reflection angle), and the optical writing type liquid crystal spatial light modulation is performed. It is configured to write vertically to the container 103. Further, the writing polygon mirror is controlled by driving the pulse motor, so that the writing polygon mirror is moved to a position of + 135 ° with respect to the luminous flux of the writing light source 151 by +6.
Since each mirror is driven to rotate by 0 ° intermittently, each mirror is sequentially turned to R.
It is located at a reflection position indicated by a mirror and is configured to keep a predetermined reflection angle with respect to incident light constant.

The light flux of the image information input to the writing color separation polygon mirror 162 is incident on any one of the R mirror, the G mirror and the B mirror, so that only one color component is extracted from the light flux of the input image. Separate and reflect. Here, it is assumed that the R component is reflected. The R component luminous flux decomposed in this way is
An image is formed on the writing surface of the optical writing type liquid crystal spatial light modulator 103.

In FIG. 5, the writing color separation polygon mirror 162 is arranged between the input image forming system 102 and the spatial light modulator 103, but the input image medium 150 and the input image forming system 1 are arranged.
02, or in the input imaging system 102. However, at this time, since each mirror in the writing color separation mirror is a reflection type, the optical axis changes due to refraction and reflection of the light flux. Therefore, it is necessary to arrange the optical system according to the variation of the optical axis.

Here, the color separation polygon mirror 162 for writing is used.
The configuration is not particularly limited to this, and it is possible to change the number of filters in the optical filter forming the polygon mirror, the order of arrangement, the area ratio of each filter, and the like according to the purpose. For example, as for the number of filters, any number of filters may be used as long as the three types of filters are sequentially and continuously positioned on the optical axis of the light flux of the input image by the rotation of the polygon mirror. Further, regarding the arrangement of each filter, it is sufficient that the three permuted filters are the R filter, the G filter, and the B filter, and the order is not particularly limited. Further, regarding the area ratio of each filter, it suffices if it is configured so as to ensure a cross sectional area of the light flux due to the input image or more.

Next, the output optical system for finally forming the write image written on the write surface of the spatial light modulator on the output image plane will be described. In this embodiment, a white light source will be used as the reading light source 153. The light flux from the reading light source 153 is converted into a substantially parallel light flux having a uniform intensity distribution by the parallel optical system 154 and is input to the reading color separation mirror.

As the reading color separation polygon mirror 163, the same one as the writing color separation polygon mirror 162 is used, and the description of the structure is omitted here. The reading color separation polygon mirror 163 shares a drive source with the writing color separation polygon mirror 162, and is rotationally driven in the direction of arrow B by a gear train or belt drive. Further, the writing color separation polygon mirror 162 and the mirror having the same color face the optical axis at substantially the same time. For example, if the light flux of the R component input image is written on the writing surface of the optical writing type liquid crystal spatial light modulator 103 in the input optical system, the light flux of the reading light source 153 that has passed through the parallel optical system 154 is the writing portion. In the same manner as the above, only the R component is input to the R mirror and the reflected R component light beam is reflected by the polarization beam splitter 15.
Enter in 5.

As shown in FIG. 5, the color separation mirror for reading is arranged between the parallel optical system 154 and the PBS 155.
Between the reading light source 153 and the parallel optical system 154, PB
It may be arranged at any position between S155 and the optical writing type liquid crystal spatial light modulator 103, between the PBS 155 and the projection lens system 170 or between the projection lens system 170 and the output image plane 156. However, at this time, similarly to the arrangement of the writing color separation polygon mirror 162, it is necessary to arrange the optical system according to the change of the optical axis due to the reflection of the mirror.

The R component light flux input to the PBS 155 is separated into P polarized light and S polarized light, and the separated and reflected R
The component S-polarized light flux is an optical writing type liquid crystal spatial light modulator 103.
Irradiate the reading surface of. In FIG. 5, only the S-polarized light separated by the PBS 155 is used, but it goes without saying that an optical system that uses a P-polarized light flux may be used.
In the optical writing type liquid crystal spatial light modulator 103, the alignment direction of the liquid crystal is adjusted in advance so that the phase is modulated when the S-polarized light flux is applied to the reading surface.

As described above, according to the image irradiated on the writing surface of the optical writing type liquid crystal spatial light modulator 103 and the modulation characteristic of the optical writing type liquid crystal spatial light modulator 103, the optical writing type liquid crystal is used. The S-polarized light flux applied to the reading surface of the spatial light modulator 103 is phase-modulated and reflected. The light flux reflected by the reading surface is converted from phase modulation into intensity modulation by passing through the PBS 155 again. The intensity-modulated light beam is imaged on the output image plane 156 such as a projection screen by the output projection lens system 170.

Here, as in the first embodiment, the PBS 155 is
Element components that perform three functions of (1) separation of the optical path of read incident light and reflected light, (2) polarization of read incident light, and (3) detection of read reflected light, but with different functions. It is also possible to share and bear.

The driving color separation polygon mirror 162, the optical writing type liquid crystal spatial light modulator 103 and the reading color separation polygon mirror 163 are driven by the writing color separation filter 160 shown in FIG. It is equivalent to the separation polygon mirror 162, and the readout color separation filter 161 is replaced with the readout color separation polygon mirror 163. This has already been described in the first embodiment, and thus detailed description thereof will be omitted. . However, in the case of the color separation polygon mirror of the present embodiment, since it is a reflection type and the mirror surface rotates around the rotation axis with respect to the optical axis of the light flux, when the color separation polygon mirror is continuously driven, the input light flux is The reflection angle constantly changes, and the irradiation position of the input light beam on the optical writing type liquid crystal spatial light modulator 103 in the writing portion or the reading portion continuously changes (scans) in a certain direction. Therefore, in order to continuously drive the color separation polygon mirror, the scanning directions for the optical writing type liquid crystal spatial light modulator 103 should be the same,
The writing color separation polygon mirror 162 and the reading color separation polygon mirror are arranged so that the input image from the writing color separation polygon mirror 162 and the color component of the reading light flux from the reading color separation polygon mirror 163 are equal. It is necessary to drive 163 and the optical writing type liquid crystal spatial modulator 103 synchronously. At this time, the light intensity required for writing to or reading from the optically writable liquid crystal spatial light modulator 103,
For example, it is necessary to set the light intensity of the light source and the irradiation time of the light flux to the writing type liquid crystal spatial light modulator 103.

Although the intermittent driving method and the continuous driving method have been described above for driving the color separation polygon mirror, for example, the writing color separation polygon mirror 162 is intermittently driven and the reading color separation polygon mirror 163 is continuously driven. Alternatively, the writing color separation polygon mirror 162 may be continuously driven, and the reading color separation polygon mirror 163 may be intermittently driven.

As described above, the irradiation time of the RGB three colors is time-divided by the rotation of the writing color separation polygon mirror 162. As a result, the input images separated into the three colors are successively formed on the writing surface of the optical writing type liquid crystal spatial light modulator 103. Further, the input images of these three colors are subjected to desired modulation for each color by the light modulation characteristic synchronization control circuit 122 and the modulator included in the drive circuit 104, and sequentially on the reading surface of the spatial light modulator according to the time zone. appear. The image subjected to the desired modulation by the spatial light modulator selects a color component by rotating the reading color separation polygon mirror 161 similarly to the writing color separation polygon mirror 160, and the reading light of the selected color component is selected. Is read out by the output projection lens system and is formed on the output image plane 156 as a final output image. This output image is an image that has been color-modulated for each color component, but if the repetition frequency of the time-divided time zones of these three colors is sufficiently high with respect to the color time response of the unaided eye, it is perceptually three. It will have the same effect as if the colors were superimposed. That is, the actual color combination is performed as if the viewer of the output sensed it, and the image visually observed is the color image after combination.

As described above, in the first embodiment, the method of rotating the writing portion and the reading portion through the color separation filter is used as the means for performing color separation while performing time division. In the second embodiment, the writing portion and the reading portion are used. A method of rotating a part through a color separation polygon mirror was used. This is because it is easy to control the writing part and the reading part to be the same, but for example, a color separation filter is used for the writing part, a color separation polygon mirror is used for the reading part, and a writing part is used. It goes without saying that the same effect can be obtained even with a combination of a color separation polygon mirror and a color separation filter in the reading portion.

Further, in the first and second embodiments, a pulse motor that can easily control the rotation speed and the position by an input pulse is used as a drive source, but the invention is not particularly limited to this, and for example, a servo motor or the like is used for position control. Control and rotation speed control may be performed. As the input image medium, a transparent film such as a negative film, a positive film, or a liquid crystal display is used, but as shown in FIG.
In the case of an input image medium such as a document or a photographic print, which is composed of the surface of an entity, the writing light source 151 is reflected and illuminated by the light condensed by the parallel optical system, and the image is input as in FIG. It may be incident on the image system 102. Therefore, the difference between the transmissive medium and the reflective medium as the input image medium is only the difference between the illumination type used for image input as the transmissive illumination and the reflective illumination, which is an essential difference for the present invention. is not. Therefore, in the description of the embodiments, only an example of reading by transmissive illumination for an input image medium that is all transparent is shown in order to avoid complication, but if the illumination form is changed, all of these examples will be input images that are reflective. It goes without saying that it can be applied to the medium.

In the present embodiment, the time-division color separation is performed in FIG. 4 by the clock of a constant frequency, but the invention is not limited to this, and the irradiation time of the light flux of the color component in the color information is independent for each color. The adjustment of the color balance in the final output, the sensitivity of the spatial light modulator with respect to the light wavelength of each color, and the like can be performed by adjusting the value.

[0063]

As described above, the present invention provides a spatial light modulator, an optical system for writing an input target image on the writing surface of the spatial light modulator, and a reading surface of the spatial light modulator. An optical system for forming the above image on the final output surface,
In a color image output device comprising a drive circuit, in the input optical system, color information of an output target image is color-separated into three colors, and the color-separated color information is time-divided and output in a first time. A second time-division color division for reading in the division color separation means and the output optical system as the same color information as the color information written in the spatial light modulator by the first time division color separation means. And a modulation control circuit for synchronously controlling the modulation characteristics of the first time division color separation means, the second time division color separation means, and the spatial light modulator in the drive circuit. With this configuration, a high-brightness output image can be obtained by the optical amplification effect of the spatial light modulator, and it is possible to avoid the loss of high-frequency components by outputting the image information as light information without converting it into an electrical scanning signal. it can. Further, in the conventional color image output device, an input optical system or an output optical system and a spatial light modulator were required for each color component, but in the present invention, one system of the input optical system or the output optical system,
The spatial light modulator makes it possible to output a color image. As a result, the number of parts of the optical system is significantly reduced, and the size of the device and the cost of the device can be reduced. Further, since the color image is output through the same optical system, it is possible to realize high-quality output without adverse effects such as color misregistration due to the aberration of the optical system that occurs when the color components are combined. Furthermore, since the irradiation time of the light flux of the color component in the color information can be adjusted independently for each color, the color balance of the final output image can also be adjusted.

In addition to these effects, there is no need for a final image composition by an optical system as in the conventional case when the image output device is manufactured, so that workability such as assembly and adjustment is significantly improved. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an exemplary embodiment of the present invention.

FIG. 2 is an explanatory diagram showing drive waveforms for a spatial light modulator used in an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an overall configuration of a first embodiment of the present invention.

FIG. 4 is a timing chart showing the driving method according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an overall configuration of a second embodiment of the present invention.

FIG. 6 is an explanatory view showing another embodiment of a part of the output optical system used in the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing an embodiment of the present invention for a light reflective image medium.

FIG. 8 is an explanatory diagram showing an example of a conventional technique.

FIG. 9 is an explanatory diagram showing another example of the conventional technique.

FIG. 10 is an explanatory diagram showing an example of a conventional technique.

FIG. 11 is an explanatory diagram showing an example of a spatial light modulator used in an embodiment of the present invention.

[Explanation of symbols]

 102 Input Imaging System 103 Optical Writing Liquid Crystal Spatial Light Modulator 104 Driving Circuit 105 Optical Modulation Characteristic Control Circuit 150 Input Image Medium 151 Writing Light Source 153 Reading Light Source 155 PBS (Polarizing Beam Splitter) 160 Writing Color Separation Filter 161 Color separation filter for reading 162 Color separation polygon mirror for writing 163 Color separation polygon mirror for reading 170 Output projection lens 211 Nematic liquid crystal

Claims (1)

[Claims] 1. A spatial light modulator and an optical system for writing an input target image on a writing surface of the spatial light modulator (hereinafter, referred to as an optical system).
This is called an input optical system), an optical system for forming an image on the reading surface of the spatial light modulator on a final output surface (hereinafter referred to as an output optical system), and a drive. In an image output device comprising a circuit, in the input optical system, the color information of the output target image is color-separated into three colors, and the color-separated color information is time-divided and output as a first time-division color And a second time division color division means for reading as color information of the same color as the color information written in the spatial light modulator by the first time division color separation means in the output optical system. In the drive circuit, a modulation control circuit for synchronously controlling the modulation characteristics of the first time-division color separation means, the second time-division color separation means, and the spatial light modulator is provided. A color image output device.