JPH04211240A - Color image processing device - Google Patents

Abstract

PURPOSE:To provide a color image processing device which carries out the high speed processings. CONSTITUTION:An original image is color-analyzed to a plurality of colors by an analogue write-in system, and witten onto an image write-in plane consisting of space light amplifying elements 10a-10c, and stored. When the laser beam in a digital read-out system performs the two-dimensional scan for the space light amplifying elements 10a-10c, the image written in the space light amplifying elements 10a-10C is read out in digital form. The read-out image data is applied with the desired image processing, and written into the space light amplifying elements 10a-10c again in digital form by the laser beam for the two-dimensional scan. In the final stage, the image is read out in analogue form from the space light demodulating elements 10a-10c, and an output image is prepared.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image processing apparatus using a spatial light modulation element.

0002

2. Description of the Related Art Color copying machines are known as devices for creating, editing, and copying full-color images. Generally, there are two types of color copying machines: analog type and digital type, and each type has its advantages and disadvantages. Analog color copying machines create color copies by exposing and developing optical images, making it difficult to perform image processing such as color correction and gradation processing. On the other hand, digital color copying machines use an image scanner to convert the original image into a digital signal, and then use a printer to create a color copy based on this digital signal, so color correction, gradation processing, etc. Processing can be performed easily.

[0003] When comparing the color copies made, analog color copying machines have a resolution of 800
Since the DPI is about the same, the image quality is smooth, but color masking to separate black and chromatic colors is not easy, and black line drawings are colored, resulting in poor color reproducibility. On the other hand, digital color copying machines facilitate color masking and have excellent color reproducibility, but it is difficult to achieve high definition. This is because as the resolution increases and the number of pixels read increases, the amount of data increases, and high-speed processors and large-capacity memory are required to process this large amount of data, making it less expensive than analog methods. This is because there is a significant disadvantage in this respect. From this point of view, analog color copying machines are advantageous when performing large-volume copy processing.
Additionally, digital color copying machines are advantageous for creating design manuscripts where color reproducibility is important, simple printing, and the like.

As mentioned above, the analog system and the digital system each have their advantages and disadvantages. Therefore, they are used differently depending on the type of image, processing purpose, use, etc. However, until now there has been no equipment that can combine the excellent processing of analog and digital methods, and in order to create high-definition images with good color reproducibility, it is extremely difficult to use digital methods. It was necessary to use expensive equipment. Furthermore, no device has existed that allows analog and digital images to coexist on one screen. For this reason, the applicant has already proposed a color image processing device that can handle mixed and fused images of analog and digital images, and has high resolution and excellent color reproducibility (patent application). No. 1-335304, December 2, 1999
5th application).

This color image processing device uses a spatial light modulation element using a liquid crystal, an analog writing system for writing an image of a single color component of the original image in an analog manner, and two laser beams.
A digital readout system that digitally reads out an image of a single color component written in a spatial light modulation element by dimensional scanning, a processing unit that performs image processing on the read image data, and a laser beam that scans two-dimensionally. a digital writing system that digitally writes the single color component image data that has undergone the above processing into the spatial light modulation element; and an analog readout system that reads out the single color component image that has been written to the spatial light modulation element in an analog manner. It is equipped with a system.

[0006]

[Problems to be Solved by the Invention] According to the color image processing device described above, when a full-color original image is to be image-processed and printed, the red component image of the original image is first sent to the spatial light modulation element in an analog manner. After writing, reading out digitally and processing the image, digitally writing again to the spatial light modulation element. The process of reading out and outputting this image in an analog manner must be performed sequentially in the same way for the green component image and the blue component image. In particular, when attempting to create a plurality of hard copies, it is necessary to perform the above-mentioned processing for the required number of output copies, which results in a lot of unnecessary processing and makes it impossible to complete the processing in a short time. SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a color image processing device that can perform high-speed processing.

[0007]

[Means for Solving the Problems] To achieve the above-mentioned objects, the present invention comprises a photoreceptor constituting an image writing plane, a liquid crystal laminated on the photoreceptor, and an electrode sandwiching the photoreceptor and the liquid crystal. an analog writing system that separates the original image into multiple colors and writes each color-separated image onto the spatial light modulator in an analog manner; A digital readout system that digitally reads out the image written in the spatial light modulation element by scanning, a processing unit that performs image processing on the readout image data, and a laser beam
a digital writing system that digitally writes the processed image data into the spatial light modulation element by dimensional scanning; and an output image is formed by reading out the image written on the spatial light modulation element in an analog manner. This is a color image processing device characterized by being equipped with an analog readout system.

[0008]

[Operation] The original image is separated into a plurality of colors by an analog writing system, and then written and stored on the image writing plane of the spatial light modulation element. The image written on the spatial light modulation element is digitally read out by scanning the spatial light modulation element two-dimensionally with a laser beam of the digital readout system. After the read image data is subjected to desired image processing, it is digitally written again into the spatial light modulation element by a two-dimensionally scanned laser beam. Finally, an output image is created by reading out the image from the spatial light modulation element in an analog manner.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram schematically showing the basic structure of a color image editing/output device according to an embodiment of the present invention. In the same figure, 10a, 10b and 10c are each red (R).
, a spatial light modulation element for green (G) and blue (B) component images. These three spatial light modulation elements 10a, 10b
and 10c change the transmittance distribution, reflectance distribution, or phase distribution of those elements according to the input spatial light intensity distribution (optical image), so the light intensity distribution, that is, the image It can be stored temporarily. When another light is irradiated onto the spatial light modulation element in which an image is stored, transmitted light, reflected light, or scattered light that is modulated according to the stored two-dimensional (spatial) image information is obtained. The written image is read by detecting or exposing the modulated transmitted light, reflected light, or scattered light.

Spatial light modulation elements 10a, 10b and 10c
The spatial intensity distribution of light input to
It may also be a digital image obtained by dimensional scanning. Furthermore, when reading out from the spatial light modulators 10a, 10b, and 10c, an analog image may be obtained by irradiating uniform light onto these spatial light modulators 10a, 10b, and 10c, or a constant intensity laser beam may be used. It may also be a digital image obtained by irradiating a beam with two-dimensional scanning. In FIG. 1, reference numeral 11 denotes a document illuminated by a white light source 12, and a reflected image from the document 11 is formed by a lens 13 and is incident on a dichroic mirror 14. Dichroic mirror 14 converts input light into R, G, and B
This is an optical element that separates colors into three colors: cyan, magenta, and yellow. For example, the R image is reflected on the surface 14a, the B image is reflected on the surface 14b, and the G image travels straight without being reflected on any surface.

The R image reflected by the surface 14a is incident on the spatial light modulation element 10a and is temporarily recorded. At the same time, B and G images are also written to the spatial light modulation elements 10b and 10c, respectively. The lens 13 and the dichroic mirror 14 correspond to the analog writing system of the present invention. Note that the dichroic mirror 14 does not need to be an integral type as shown in FIG. 1, and may be a divided type divided into a plurality of parts. As a mechanism for performing color separation, various mechanisms such as a filter may be used in addition to a dichroic mirror. A digital readout system that digitally reads out images written in the spatial light modulation elements 10a, 10b, and 10c includes three sets of laser modulation circuits 15a, 15b, and 15c.
, three sets of laser light sources 16a, 16b and 16c, and 3
a set of laser beam scanning systems 17a, 17b and 17c;
It has three sets of light receiving elements 18a, 18b, and 18c.

Laser modulation circuits 15a, 15b and 15c
The light receiving elements 18a, 18b and 18c are connected to the processing section 19.
electrically connected to. The operation of this digital readout system will be explained for an R image. A laser beam with a constant light intensity emitted from a laser light source 16a is applied to a laser beam scanning system 17a and deflected in vertical and horizontal directions. Thereby, the laser beam scans the spatial light modulation element 10a two-dimensionally. Transmitted light, reflected light, or scattered light modulated according to the image information of the pixel corresponding to the laser beam spot is applied to the light receiving element 18a and photoelectrically converted. The photoelectrically converted image information is sent to the processing section 19. In this way, the R image information written on the spatial light modulation element 10a can be read out in time series. G
and B images are processed in the same way as the R image. Moreover, processing of each R, G, and B image is executed simultaneously.

Spatial light modulation elements 10a, 10b and 10c
The digital writing system for digitally writing an image on the digital reading system includes three sets of laser modulation circuits 15a and 15.
b and 15c, three sets of laser light sources 16a, 16b and 16c, and three sets of laser beam scanning systems 17a, 17b and 17c are shared. The operation of this digital writing system will be explained for the R image system. By applying the processed digital image signal from the processing unit 19, the laser modulation circuit 15a modulates the light intensity of the laser beam emitted from the laser light source 16a. The light intensity of this laser beam represents the gradation of the pixel corresponding to the laser beam spot. Next, the laser beam is applied to the laser beam scanning system 17a and deflected in the vertical and horizontal directions, so that the laser beam scans the spatial light modulation element 10a two-dimensionally. The laser modulation circuit 15a and the laser beam scanning system 17a are driven in synchronization with each other.

In this way, a digital image can be written on the spatial light modulator 10a. The G and B images are processed in the same way as the R image, and these processes are also processed simultaneously, as in the case of reading described above. Spatial light modulation elements 10a, 10b, 10c
The analog readout system that reads out the image written in the
c, R, G, and B transmissive color filters 21a,
21b and 21c and lenses 22a, 22b and 22c
, a movable mirror 23 , and a lens 24 . The white light from the white light sources 20a, 20b and 20c is
and B color filters 21a, 21b and 21c to produce a specific spectrum of light, and further lenses 22a, 2
After the parallel light is made into parallel light by 2b and 22c, it is applied to the spatial light modulation elements 10a, 10b and 10c, respectively.

[0015] As a result, each spatial light modulator 10a,
The R, G and B images respectively stored in 10b and 10c are simultaneously read out and transferred to the dichroic mirror 14.
are applied from three directions and combined. The optical path of the color image obtained by combining is switched by a movable mirror 23,
An image is formed on photosensitive paper 25 by lens 24, and exposure is performed. The exposed photosensitive paper 25 then undergoes a development process to become a hard copy.

Note that in this embodiment, the color filter 2
1a, 21b and 21c do not necessarily need to be provided. The movable mirror 23 is located in the state shown by the broken line in FIG. 1 during analog writing, and is located in the state shown by the solid line in FIG. 1 during analog reading. Laser light sources 16a, 16b and 16
c is a semiconductor laser or helium-neon He-N
A gas laser such as e (He-Ne) is used. Since semiconductor lasers are small, the entire device can be configured compactly. Furthermore, since the gas laser has good coherence, the spot diameter of the laser beam can be made small, thereby making it possible to further improve the readout resolution. The laser beam scanning systems 17a, 17b, and 17c are composed of a main scanning section and a sub-scanning section. The main scanning section causes the laser beam spot to scan one line on the spatial light modulation element. The sub-scanning section scans the laser beam spot in a direction perpendicular to the main-scanning direction. That is, when main scanning of one line is completed, the spot is moved to the next line. In this way, the laser beam spot is caused to two-dimensionally scan the spatial light modulation element by the main scanning section and the sub-scanning section.

The main scanning section is composed of a hologram scanner, a rotating polygon mirror, an ultrasonic deflector, a galvanometer, and the like. Further, the sub-scanning section is composed of a hologram scanner, a galvanometer, or the like. This sub-scanning may be performed by mechanically moving the spatial light modulation element. Light receiving element 18a
, 18b and 18c can be constructed from high-speed photodiodes. When the laser beam is shaped like a slit extending in the sub-scanning direction in order to read out several lines of image information in the sub-scanning direction at once, a diode array or CCD can be used as the light receiving element. A signal is applied from the processing section 19 to the laser modulation circuits 15a, 15b, and 15c, and the intensity of the laser beam generated from the laser light sources 16a, 16b, and 16c is modulated according to this signal. When semiconductor lasers are used as the laser light sources 16a, 16b, and 16c, direct modulation is possible by modulating their drive currents, but when gas lasers are used, a modulation method (not shown) is used to externally modulate the emitted laser beams. ) is required.

The processing section 19 is mainly composed of a computer including a microprocessor, a memory, etc., and performs digital image processing on the image signals applied from the light receiving elements 18a, 18b, and 18c of the digital readout system. The image signal is output to digital writing system laser modulation circuits 15a, 15b, and 15c. Digital image processing includes gradation processing (gamma correction, shading correction), sharpening (sharpness emphasis), area specification (cropping, masking), color processing (color reproduction, paint function, cropping by color), movement (rotation, etc.) , editing processing (inset composition, character composition), etc. There is no need to perform any particular image processing.

Image editing and output functions can be obtained by combining all of the above configurations. That is, an image editing function can be obtained by combining a spatial light modulation element, a digital reading system, a processing section, and a digital writing system. Furthermore, an image scanner function can be obtained by combining an analog writing system, a spatial light modulation element, and a digital reading system. Furthermore, a printer function can be obtained by combining a digital writing system, a spatial light modulation element, and an analog reading system. An analog copying function can be obtained by combining an analog writing system, a spatial light modulation element, and an analog reading system. Each of these functional modes is realized by the computer of the processing section 19.

Note that the processing section 19 includes a digital output device 2.
6 can be connected. This digital output device 26
Examples include laser printers, general image processing equipment, and VDs.
A monitor device such as T can be used. FIG. 2 is a block diagram schematically showing the basic structure of a color image editing/output device according to another embodiment of the present invention. In the same figure, 110a
, 110b and 110c are red (R) and green (
This is a spatial light modulation element for G) and blue (B) component images. These spatial light modulation elements 110a, 110b and 11
0c is attached to a rotating body (not shown), and as this rotating body rotates, writing and reading positions (
(the position of the spatial light modulator 110b in the same figure). In this case, the number of spatial light modulation elements is not limited to three, but a large number (preferably a multiple of three) may be prepared.

Note that these spatial light modulators 110a,
110b and 110c may be attached to a moving body that moves linearly instead of a rotating body. Each spatial light modulation element 11
Color filters 114a, 114b and 114c of three colors R, G and B or cyan, magenta and yellow are fixed to 0a, 110b and 110c, respectively. When the original 111 is illuminated by the white light source 112, the reflected image from the original 111 is reflected by the lens 1.
13 and is incident on one of the spatial light modulation elements 110a, 110b, and 110c, where it is temporarily recorded. This white light source 112 can be rotated as shown by the arrow to change the irradiation direction. Spatial light modulation element 110a
, 110b and 110c, and a laser modulation circuit 115 and a laser as a digital writing system that digitally writes processed images to the spatial light modulation elements 110a, 110b and 110c. Only one set of light source 116, laser beam scanning system 117, and light receiving element 118 is provided. Laser modulation circuit 115 and light receiving element 118
is electrically connected to the processing section 119.

Digital read and write operations are substantially the same as in the embodiment of FIG. However, in this embodiment, since the digital reading system and the digital writing system are one set, the spatial light modulation elements 110a and 110
b and 110c are processed only by sequentially moving them to the write and read positions. For analog read operation, first,
The spatial light modulation element is illuminated by changing the irradiation direction of the white light source 112. As a result, a reflected image from the spatial light modulation element located at the write and read positions is formed on the photosensitive paper 125 via the movable mirror 123 and the lens 124, and exposed. Spatial light modulation elements 110a, 110b and 110c
are sequentially moved to the writing and reading positions to expose each of the R, G, and B images onto the photosensitive paper 125 three times in total. The exposed photosensitive paper 125 then undergoes a development process to become a hard copy.

The movable mirror 123 is located in the state shown by the broken line in FIG. 2 during analog writing, and is located in the state shown by the solid line in FIG. 3 during analog reading. When printing multiple copies of the same color image, each spatial light modulation element 110
Each image from a, 110b and 110c is printed on photosensitive paper 125.
It is sufficient to sequentially expose the top three times for each sheet. R, G and B
The image information of the spatial light modulators 110a, 110b and 1
10c, there is no need to perform analog writing processing from the original each time, and it is only necessary to sequentially switch the spatial light modulation elements 110a, 110b, and 110c to perform exposure. Note that if a larger number of spatial light modulators are used, different types of images can be stored in the spatial light modulators, and different types of color images can be printed at high speed.

FIG. 3 is a block diagram schematically showing the basic structure of a color image editing/output device according to still another embodiment of the present invention. In the figure, 320 is a spatial light modulation element for red (R), green (G), and blue (B) component images. Since the spatial light modulation element 320 changes its transmittance distribution, reflectance distribution, or phase distribution according to the input spatial light intensity distribution (optical image), the light intensity distribution, that is,
Images can be stored temporarily. When another light is irradiated onto the spatial light modulation element in which an image is stored, transmitted light, reflected light, or scattered light that is modulated according to the stored two-dimensional (spatial) image information is obtained. By detecting or exposing this modulated transmitted light, reflected light, or scattered light, the written image is read out. The spatial light intensity distribution input to the spatial light modulation element 320 may be an analog image that is an optical image, or may be a digital image obtained by two-dimensionally scanning a modulated laser beam. Further, for reading out from the spatial light modulation element 320, an analog image may be obtained by irradiating uniform light onto the spatial light modulation element 320, or a laser beam of a constant intensity may be used to obtain an analog image.
It may also be a digital image obtained by irradiating with dimensional scanning.

In FIG. 3, reference numeral 321 indicates a white light source 322.
The reflected image from this original 321 is formed by a lens 323 and is incident on a dichroic mirror 324. The dichroic mirror 324 is an optical element that separates input light into three colors of R, G, and B or three colors of cyan, magenta, and yellow. for example,
The R image is reflected on the surface 324a, the B image is reflected on the surface 324b, and the G image travels straight without being reflected on any surface. The image of R reflected by the surface 324a is the mirror 3
25 and enters the spatial light modulation element 320a where it is temporarily recorded. At the same time, the B image reflected by the surface 324b is further reflected by the mirror 326 and temporarily recorded on the spatial light modulation element 320c. Furthermore, at the same time, the G image is also temporarily recorded on the spatial light modulation element 320b.

Lens 323 and dichroic mirror 3
24 and mirrors 325 and 326 correspond to the analog writing system of the present invention. Note that the dichroic mirror 324 does not need to be an integral type as shown in FIG. 3, and may be a divided type divided into a plurality of parts. As a mechanism for performing color separation, various mechanisms such as a filter may be used in addition to a dichroic mirror. Note that by providing a shutter that can temporarily block the reflected image from the original 321 between the original 321 and the dichroic mirror 324, a moving image can be written on the spatial light modulation element 320. A digital readout system for digitally reading out images written in the spatial light modulation elements 320a, 320b, and 320c includes a light source 328, a laser beam scanning system 329, and a light receiving element 330 common to each area. Light receiving element 3
30 is electrically connected to a processing section 331.

A laser beam of constant light intensity emitted from a laser light source 328 is applied to a laser beam scanning system 329 and deflected in vertical and horizontal directions. This allows the laser beam to pass through the spatial light modulators 320a, 320b, and 320c.
are scanned two-dimensionally. Transmitted light, reflected light, or scattered light modulated according to the image information of the pixel corresponding to the laser beam spot is applied to the light receiving element 320 and photoelectrically converted. The photoelectrically converted image information is sent to the processing section 331. When the spatial light modulation element 320a is two-dimensionally scanned, R image information can be read out in time series, a G image is read out from 320b, and a B image is read out from 320c. A digital writing system for digitally writing images on the spatial light modulation elements 320a, 320b, and 320c includes a laser modulation circuit 327, a laser light source 328, and a laser beam scanning system 329.
This is shared with the digital readout system.

The laser modulation circuit 327 modulates the light intensity of the laser beam emitted from the laser light source 328 by applying the processed digital image signal from the processing section 321 . The light intensity of this laser beam represents the gradation of the pixel corresponding to the laser beam spot. Next, the laser beam is applied to the laser beam scanning system 329 and deflected in the vertical and horizontal directions, so that the laser beam scans each of the spatial light modulation elements 320a, 320b, and 320c two-dimensionally. Laser modulation circuit 327
and laser beam scanning system 329 are driven in synchronization with each other. An R digital image is written in the spatial light modulation element 320a, a G digital image is written in 320b, and 32
Each digital image of B is written in 0c. An analog readout system for reading out images written in the spatial light modulation elements 320a, 320b, and 320c in an analog manner includes a white light source 332 and the above-mentioned dichroic mirror 324.
It has a movable mirror 333 and a lens 334.

Uniform white light from a white light source 332 is applied to the entire surface of the spatial light modulator 320 . As a result, the R, G, and B images respectively stored in the spatial light modulation elements 320a, 320b, and 320c are read out simultaneously. In this case, each image read out is a projection image of white light, which can be directly or
26 and applied to the dichroic mirror 324 from three directions. The white light projection image of the R image of the spatial light modulator 320a is the surface 32 of the dichroic mirror 324.
By being reflected by 4a, a projected image of red light appears on surface 324c. In addition, the white light projection image of the image B of 320c is the surface 324 of the dichroic mirror 324.
By being reflected by b, a projected image of blue light appears on the surface 324c. Further, in the white light projection image of the G image 320b, only green light is transmitted, and a projected image of green light appears on the surface 324c. In this way,
The R, G, and B images stored in the spatial light modulators 320a, 320b, and 320c, respectively, become projected images of red, green, and blue light, which are applied to the surface 324c of the dichroic mirror 324 and combined to form a color image. becomes.

The optical path of the combined color image is switched by a movable mirror 333, and the image is formed on a photosensitive paper 335 by a lens 324 for exposure. The exposed photosensitive paper 335 then undergoes a development process to become a hard copy. The movable mirror 333 is located in the state shown by the broken line in FIG. 3 during analog writing, and is located in the state shown by the solid line in FIG. 3 during analog reading. Laser light source 32
8 is a semiconductor laser or helium-neon (He-
A gas laser such as Ne) is used. Since semiconductor lasers are small, the entire device can be configured compactly. Furthermore, since the gas laser has good coherence, the spot diameter of the laser beam can be made small, thereby making it possible to further improve the readout resolution.

The laser beam scanning system 329 consists of a main scanning section and a sub scanning section. The main scanning section causes the laser beam spot to scan one line on the spatial light modulation element. The sub-scanning section scans the laser beam spot in a direction perpendicular to the main-scanning direction. That is, when main scanning for one line is completed, the spot is moved to the next line. In this way, the laser beam spot is caused to two-dimensionally scan the spatial light modulation element by the main scanning section and the sub-scanning section. The main scanning section includes a holographic scanner, a rotating polygon mirror, an ultrasonic deflector, a galvano mirror, and the like. Further, the sub-scanning section is composed of a holographic scanner, a galvano mirror, or the like. This sub-scanning may be performed by mechanically moving the spatial light modulation element.

The light receiving element 330 can be constructed of a high speed photodiode. When the laser beam is shaped like a slit extending in the sub-scanning direction in order to read out several lines of image information in the sub-scanning direction at once, a diode array or CCD can be used as the light receiving element. A signal is applied from the processing section 331 to the laser modulation circuit 327, and the intensity of the laser beam generated from the laser light source 328 is modulated in accordance with this signal. When a semiconductor laser is used as the laser light source 328, direct modulation is possible by modulating its drive current, but when a gas laser is used, a modulator (not shown) is required to externally modulate the emitted laser beam. . The processing unit 331 is mainly composed of a computer including a microprocessor, memory, etc., and performs digital image processing on the image signal applied from the light receiving element 330 of the digital reading system, and sends the processed image signal to the digital writing system. Output to laser modulation circuit 327.

Digital image processing includes gradation processing (gamma correction, shading correction), sharpening (sharpness emphasis), area specification (trimming, masking), color processing (color reproduction, paint function, cropping by color), movement ( (rotation, etc.), editing processing (inset composition, character composition), etc. However, the processing unit 331 does not necessarily need to perform any special processing. Image editing and output functions can be obtained by combining all of the above configurations. That is, a spatial light modulation element, a digital readout system,
An image editing function can be obtained by combining a processing section and a digital writing system. Furthermore, an image scanner function can be obtained by combining an analog writing system, a spatial light modulation element, and a digital reading system. Furthermore, a printer function can be obtained by combining a digital writing system, a spatial light modulation element, and an analog reading system. An analog copying function can be obtained by combining an analog writing system, a spatial light modulation element, and an analog reading system. These case function modes are realized by the computer of the processing section 331.

Note that a digital output device 336 can be connected to the processing section 331. As this digital output device 336, a laser printer, a general image processing device, a monitor device such as a VDT, etc. can be used. FIG. 4 shows a configuration diagram when the spatial light modulation element 320 in the embodiment of FIG. 3 is configured as a single element. In FIG. 4, the spatial light modulators 420 are 420a, 420b, and 420.
It is divided into three regions 320a, 320b, and 320c in the embodiment of FIG. Operations such as image writing and reading are completely the same as in the case of FIG. 3 described above, and will therefore be omitted. (In FIG. 4, the same components as in FIG. 3 are given the same reference numerals.) FIG. 5 is a cross-sectional view showing an example of the configuration of the spatial light modulation element. In the figure, 40 and 41 are glass plates arranged at both ends, and these glass plates 40 and 41
Electrodes 42 and 43 are laminated on the entire inner surface of the substrate. A photoreceptor 44 is laminated inside the electrode 42 . A spacer 45 is inserted between the electrode 43 and the photoreceptor 44, and a liquid crystal 46 is injected into the space formed by the electrode 43, the photoreceptor 44, and the spacer 45 and sealed. An AC power source 47 is connected to the electrodes 42 and 43. The electrodes 42 and 43 are transparent electrodes, and are preferably formed of indium tin oxide (ITO) films. As the photoreceptor 44, a material whose electrical resistance changes with light, a material which generates a voltage with light, a material which generates a current with light, a material whose structure changes with light, or a material which changes temperature with light is used. Materials whose electrical resistance changes with light (photoconductors) include cadmium sulfide (CdS), cadmium telluride (CdTe),
Examples include selenium (Se), zinc sulfide (ZnS), bismuth silicate crystal (BSO), amorphous silicon, and organic photoconductors. Note that when handling color images, it is best to use amorphous silicon as the photoconductor. That is, amorphous silicon is suitable for writing color image information because its wavelength sensitivity is relatively flat over the entire visible light region.

Materials that generate voltage by light include solar cells. Additionally, photochromic compounds are materials whose structure changes when exposed to light. This material has the ability to directly change the molecular orientation of liquid crystals without electricity by changing the structure of the material. In this way, any material that can change the alignment state of the liquid crystal 46 with light can be used as the photoreceptor 44. The glass plates 40 and 41 are transparent and function as substrates for sealing the liquid crystal 46. Therefore, a transparent plastic plate or a transparent ceramic plate may be used instead of the glass plate. The liquid crystal 46 used has a memory function. In this configuration example, a mixed liquid crystal in which nematic liquid crystal and cholesteric liquid crystal are mixed at a weight ratio of about 9:1 is used.

The write and read operations of this example using this mixed liquid crystal will be explained below. electrodes 42 and 4
When a low-frequency alternating current voltage of about 100 Hz is applied from the power source 47 between 3 and 3, the mixed liquid crystal undergoes dynamic scattering and becomes cloudy. This state is maintained and memorized even if the voltage is removed. This phenomenon will be applied to spatial light modulators. When performing analog writing, a low frequency alternating current voltage of approximately 100 Hz and an optical analog image are simultaneously applied to the spatial light modulation element 20. When writing is completed, the AC voltage from the power supply 47 is cut off. When performing digital writing, a low-frequency AC voltage of about 100 Hz and a laser beam are simultaneously applied to this spatial light modulation element, and when writing is completed, the AC voltage from the power source 47 is cut off.

Next, a description will be given of the operation of overlapping writing of an image written in analog form and an image formed in digital writing. The digital image has no gradation and R, G
In the case of an image in which B and B are each expressed in about two values (eight colors), it is best to write the analog image and then directly overlay the digital image. Or, conversely, the analog image may be directly overlaid on top of the digital image. On the other hand, when writing a digital image having gradation, an analog image is first written, then the portion where the digital image is to be written is erased, and then the digital image is written. Before writing a digital image, partial erasing is required to return the area where the digital image is to be written to its initial state.

This partial erasure is performed as follows. While applying an alternating current voltage with a high frequency (eg, 700 Hz) higher than the cutoff frequency between the electrodes 42 and 43, a laser beam having a constant light intensity is two-dimensionally scanned and uniformly irradiated onto the area where a digital image is to be written. As a result, the resistance of the photoreceptor 44 in the portion irradiated with the laser beam becomes low, and a high frequency voltage is applied only to the liquid crystal 46 in that portion, thereby performing partial erasing. Thereafter, as in the case described above, a low frequency alternating current voltage of approximately 100 Hz and a laser beam are simultaneously applied between the electrodes 42 and 43, and a digital image is written in that portion. In order to erase the entire surface of the written image, it is sufficient to apply a high frequency (for example, 700 Hz) AC voltage between the electrodes 42 and 43, and at the same time apply uniform light to the entire surface of the photoreceptor 44.

When all writing is completed, the electrodes 42 and 43
The electrodes 42 and 43 are short-circuited to remove any remaining charge. The changes in the liquid crystal during writing are as follows. That is, the resistance of the photoreceptor 44 in the portion hit by the light decreases, and a voltage is applied to the liquid crystal 46 in that portion. This voltage causes the liquid crystal molecules to enter a turbulent state, and this state is maintained even after the applied voltage is removed. On the other hand, when the liquid crystal is irradiated with a laser beam of constant light intensity during readout, the laser beam is scattered according to the turbulent flow state of the liquid crystal molecules. Therefore, the gradation of that pixel can be read from the light intensity of this scattered light. During analog readout, uniform light is irradiated onto the liquid crystal, and the transmitted light is transferred to the photosensitive paper 3 using a lens 34.
5 to obtain the entire image.

Note that other liquid crystals having a memory function can be used as the liquid crystal 46. For example, it may be a phase change type liquid crystal, a smectic A type liquid crystal, or a ferroelectric type liquid crystal. When a liquid crystal having a memory function is used as described above, writing is not performed unless both light and voltage are simultaneously applied to the photoreceptor. That is, even if the photoreceptor is irradiated with a reading laser beam or uniform light, the written image will not change. Therefore, there is no need to provide a light shielding film between the liquid crystal and the photoreceptor to prevent light from being applied to the photoreceptor during reading, and the readout optical system can be of a transmission type. Furthermore, the reading laser beam may be applied from the glass plate 40 side or from the glass plate 41 side. Alternatively, a reflective type may be provided by providing a light shielding film. In particular, as shown in each of the above embodiments, if the reading laser beam is applied from the same side as the writing laser beam, most of the optical system can be shared between the digital writing system and the digital reading system. can.

As described above, according to the color image editing/output device of this embodiment, it is possible to handle images in which analog images and digital images are mixed or combined. especially,
Since the spatial light modulation element is compatible with the three colors of R, G, and B, it is possible to process images of the three colors of R, G, and B in parallel, allowing for extremely high-speed image input, editing, and output. It can be carried out. Furthermore, since R, G, and B images can be simultaneously exposed onto photosensitive paper in one analog readout process, printing a plurality of sheets of the same color image can be processed very quickly and easily.

[0042]

Effects of the Invention As described in detail above, according to the present invention, a spatial light modulation element comprising a photoconductor constituting an image writing plane, a liquid crystal laminated on the photoconductor, and an electrode sandwiching the photoconductor and the liquid crystal. , an analog writing system that separates the original image into multiple colors and writes each color-separated image onto a spatial light modulation element in an analog manner, and spatial light modulation by two-dimensionally scanning a laser beam on the spatial light modulation element. A digital readout system that digitally reads out the image written on the element, a processing unit that performs image processing on the readout image data, and a spatial light modulation element that processes the image data by scanning the laser beam two-dimensionally. It is equipped with a digital writing system that writes digitally into the spatial light modulator, and an analog readout system that reads out the images written in the spatial light modulation element in an analog manner and synthesizes them to form an output image. Even when handling mixed or fused images, it is possible to realize a color image processing device that has a simple configuration and is easy to assemble, and can output and process full-color original images at high speed. Also,
When printing out a large number of the same color images, each color-separated image is stored in the spatial light modulation element, so very high-speed printing can be performed simply by performing exposure processing.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of a color image processing device of the present invention.

FIG. 2 is a configuration diagram of another embodiment of the color image processing device of the present invention.

FIG. 3 is a configuration diagram of still another embodiment of the color image processing device of the present invention.

FIG. 4 is a configuration diagram of another embodiment of the color image processing device of the present invention.

FIG. 5 is a cross-sectional view showing an example of the configuration of a spatial light modulation element.

[Explanation of symbols]

10a, 10b, 10c Spatial light modulation element 11 Original 12 White light source 13 Lens 14 Dichroic mirror 15a, 15b, 15c Laser modulation circuit 16a, 1
6b, 16c Laser light sources 17a, 17b, 17c
Laser beam scanning system 18a, 18b, 18c Light receiving element 19 Processing section 21a, 21c, 21b Color filter 23
Movable mirror 25 Recording paper

Claims (4)

[Claims] 1. A spatial light modulation element comprising a photoreceptor constituting an image writing plane, a liquid crystal laminated on the photoreceptor, and electrodes sandwiching the photoreceptor and the liquid crystal, and a spatial light modulator that separates an original image into a plurality of colors. an analog writing system for writing each of the color-separated images onto the spatial light modulation element in an analog manner; and an image written on the spatial light modulation element by two-dimensionally scanning a laser beam on the spatial light modulation element. a digital reading system that digitally reads out the image data; a processing unit that performs image processing on the read image data; and a processing unit that digitally writes the processed image data to the spatial light modulation element by two-dimensionally scanning a laser beam. A color image processing device comprising: a digital writing system; and an analog reading system that reads out an image written in the spatial light modulation element in an analog manner to form an output image. 2. The color image processing device according to claim 1, wherein the liquid crystal has a memory function. 3. The color image processing apparatus according to claim 1, further comprising a plurality of spatial light modulation elements according to a plurality of color-separated images. 4. The color image processing device according to claim 1, wherein the spatial light modulation element is divided into a plurality of regions corresponding to a plurality of color-separated images.