JPH03243936A - Image processor - Google Patents

Abstract

PURPOSE:To handle an image where analog and digital images coexist or are mixed and to reproduce an image at a high resolution and with good color reproduction by properly using an analog processing or a digital process according to the type of the image. CONSTITUTION:An analog writing system 11 with which an original image 18 is written to a space light modulator element 10 analogously and a digital reading system 13 with which the image written over the space light modulator 10 is read digitally are provided, and a processing part 15 executing the image processing of the read image is further provided. Then a digital writing system 14 digitally writing the image data subjected to the above processes on the space space light modulator element 10, and an analog reading system 12 analogously reading the written image are provided. Here, since ferroelectric liquid crystal with a storing effect is utilized as the liquid crystal of the space light modulator element 10, light for reading can be emitted from either side of the space modulator element. Thus, the image where the analog image and the digital image coexist and are mixed can be handled, and the high resolution color reproduction can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image processing device using a spatial light modulation element.

[Prior Art] Color copying machines are known as devices for creating, editing, and copying full-color images.

Color copying machines generally come in two types: 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 according to this digital signal, so color correction, gradation processing, etc. Image processing etc. can be easily performed.

In this specification, the term "image processing" refers to gradation processing (gamma correction, shading correction), sharpening (sharpness emphasis), area specification (trimming, masking), color processing (color reproduction, paint function, color-based It is used in a broad sense, including processing such as cutting out), movement (rotation), editing processing (inset composition, character composition), etc.

Comparing the color copies produced, analog color copiers have superior image quality and smoothness (resolution of 8
00 DPI), but color masking (separation of black and chromatic colors) is not easy and color reproducibility is not very good. Specifically, black line drawings are colored. on the other hand,
Digital color copying machines facilitate color masking and have excellent color reproducibility, but it is difficult to achieve high definition. Increasing the number of pixels to read with higher resolution increases the amount of data and requires a high-speed processor and large-capacity memory, making it significantly disadvantageous in terms of cost compared to analog methods.

From this point of view, analog color copiers are advantageous when performing large-volume copy processing, while digital color copiers are useful for creating design manuscripts where color reproducibility is important, simple printing, etc. It will be advantageous.

Table 1 summarizes the comparison between analog color copying machines and digital color copying machines.

Table 1 [Problems to be Solved by the Invention] As mentioned above, analog and digital methods each have their advantages and disadvantages, so they are used differently depending on the type of image, processing purpose, application, etc. .

However, conventionally, there has been no single device capable of processing both analog and digital methods, and in order to use them separately in this way, it was necessary to prepare at least two devices.

Furthermore, conventionally, there has been no device that can perform a combination of excellent processing using an analog method and excellent processing using a digital method. Therefore, in order to create high-definition images with good color reproducibility, it has been necessary to use very expensive digital equipment.

Furthermore, conventionally, there has been no device that allows analog images and digital images to coexist on one screen.

Therefore, an object of the present invention is to provide an image processing apparatus that can handle images in which analog images and digital images are mixed or combined.

Another object of the present invention is to provide an image processing device that has high resolution, excellent color reproducibility, and can be realized at low cost.

[Means for Solving the Problems] The features of the present invention for achieving the above-mentioned objects include a photoconductor constituting an image writing plane, a ferroelectric liquid crystal layered on the photoconductor and having a memory function, and a ferroelectric liquid crystal layered on the photoconductor and having a memory function. A spatial light modulation element equipped with electrodes sandwiching a conductor and a liquid crystal, an analog writing system for writing an original image onto the spatial light modulation element in an analog manner, and a laser beam two-dimensionally scanned over the spatial light modulation element. A digital readout system that digitally reads out the image written in the spatial light modulation element, a processing unit that performs image processing on the readout image data, and image data that has undergone the aforementioned processing by two-dimensionally scanning a laser beam. The present invention is equipped with a digital writing system for digitally writing an image into a spatial light modulation element, and an analog readout system for reading out an image written on the spatial light modulation element in an analog manner.

[Operation] First, an original image is written on the spatial light modulation element in an analog manner, and the image thus written on the spatial light modulation element is digitally read out for each pixel by a two-dimensionally scanned laser beam. .

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, the image is read out from the spatial light modulator in an analog manner.

Since a ferroelectric liquid crystal having a memory function is used as the liquid crystal of the spatial light modulation element, reading light can be irradiated from either side of the spatial light modulation element. Therefore, writing processing and reading processing can be performed from the same side of the spatial light modulation element.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram schematically showing the basic structure of a color image editing/output device as an embodiment of the present invention.

In the figure, 10 is a spatial light modulation element having an image writing plane, 11 is an analog writing system of an image to the spatial light modulation element 10, 12 is an analog reading system, 13 is a digital reading system, and 14 is a digital writing system. It shows.

The digital reading system 13 and the digital writing system 14 are electrically connected to a processing section I5 that performs various image processing. The processing section 15 includes a display 16 and a control section 1.
7 is connected.

The control section 17 is mainly composed of a computer, and is electrically connected to the above-described analog write system 11, analog read system 12, digital read system 13, and digital write system 14. In FIG. 2, white arrows represent analog optical images, black arrows represent digital optical images, and broken lines represent electrical signals.

The spatial light modulation element 10 changes the transmittance distribution, reflectance distribution, or phase distribution according to the input spatial light intensity distribution (light image), so that the spatial light modulation element 10 changes the light intensity distribution, that is, the image. can be temporarily stored. When the spatial light modulation element that stores an image is irradiated with other light, the transmitted light, reflected light, or scattered light is modulated according to the stored two-dimensional (spatial) image information. By detecting or exposing the modulated transmitted light, reflected light, or scattered light, the written image is read out.

The spatial light intensity distribution input to the spatial light modulator IO may be an analog image that is an optical image, or a digital image obtained by two-dimensionally scanning a modulated laser beam. . Further, reading from the spatial light modulation element 10 may be performed by irradiating negative light onto the spatial light modulation element 10 to obtain an analog image, or by two-dimensionally scanning a laser beam with a constant intensity. It may also be a digital image obtained by.

The analog writing system 11 has a function of writing an optical image of the original image on the original document 18 onto the spatial light modulation element 10, and writes the optical image of the original image obtained by the light source that illuminates the original image onto the spatial light modulation element 10. It mainly consists of an optical system that forms an image on the image.

The analog readout system 12 has a function of projecting an optical image written on the spatial light modulation element 10 onto a recording paper 19 such as photosensitive paper, and has a function of projecting an optical image written on the spatial light modulation element 10 onto a recording paper 19 such as photosensitive paper. It mainly consists of an optical system that forms an image of the spatial light modulator 10 on the recording paper 19.

The digital readout system 13 has a function of reading out the image written in the spatial light modulation element 10 in a time-series manner as an image signal by scanning and irradiating the image with a laser beam in two-dimensional manner. It mainly consists of a light receiving system and a light receiving system.

The digital writing system 14 writes a digital image to the spatial light modulation element 10 based on the image signal given from the processing section 15.
It has a writing function and mainly consists of a laser light source, a laser beam scanning system, and a laser beam modulation section.

The processing unit 15 performs digital image processing on the image signal applied from the digital reading system 13 and outputs the processed image signal to the digital writing system 14. The results processed by the processing section 15 are displayed on the display 16.

Image editing and
Provides output functionality. Furthermore, an image editing function can be obtained by combining the spatial light modulation element 10, the digital reading system 13, the processing section 15, and the digital writing system 14. Further, by combining the analog writing system 11, the spatial light modulation element io, and the digital reading system 13, an image scanner function can be obtained. Furthermore, a digital writing system 14, a spatial light modulation element 10.
By combining the analog readout system 12 and the analog readout system 12, a printer function can be obtained. By combining the analog write system 11, the spatial light modulator 10, and the analog read system 12, an analog copying function can be obtained. Each of these functional modes is realized by the computer of the control unit 17.

FIG. 1 shows the configuration of the embodiment shown in FIG. 2 in more detail.

The analog writing system 11 shown in FIG. 2 is R (red),
Three light sources: G (green) and B (blue) (e.g. fluorescent lamps)
lla Xl1b, llc and a lens 11 (represented by an optical system denoted by l). By sequentially illuminating the original 18 with light such as - from the light source 11a % jib % llc, an optical image of the original image is formed. is the lens li
d is reduced and projected onto the writing plane of the spatial light modulator 10.

To separate a color image, process it sequentially.

For one original image, first turn on the R light source 11a, write the optical image on the spatial light modulator 10, read out the image, and then turn on the G light source 11b to write the optical image into the spatial light modulator 10. After writing to the light modulation element 10 and reading out the image, similar processing is performed for the B light source 11c.

In addition to the light source switching method described above, in order to obtain a color-separated image,
There is a color filter method.

This color filter method is a method in which R, G, and B color filters are provided between the lens lid and the spatial light modulation element 10, and these are sequentially switched to obtain a color-separated image. Specifically, the R and GlB color filters are sequentially switched by attaching them to, for example, a rotating body and rotating the body. In the color filter method, a white light source such as a halogen light bulb is used as a light source.

Note that in the light source switching method and color filter method, the three colors of cyan, yellow, and magenta may be used instead of the three colors of R, G, and B.

The digital readout system 13 includes a laser light source 13a1, a laser beam scanning system 13b, a condenser lens 13C1, and a light receiving element 13d. A laser beam with constant light intensity emitted from the laser light source 13a is transmitted to the laser beam scanning system 1.
3b and is deflected in the vertical and horizontal directions. As a result, the laser beam scans the spatial light modulator 10 two-dimensionally. Transmitted light, reflected light, which is modulated according to the image information of the pixel corresponding to the laser beam spot,
Alternatively, the scattered light is applied to the light receiving element 13d via the lens 13c and photoelectrically converted. In this way, the image information written on the spatial light modulation element 10 can be read out in time series. To obtain color image information, such a readout operation is performed for each of the R, G, and B color separated images. The read image information is sent to the processing section 15.

The laser light source 13a is a semiconductor laser or a laser made of HeNe (helium-neon) or the like. Since semiconductor lasers are small, the entire device can be constructed compactly. In addition, gas lasers have good coherence, so the spot diameter of the laser beam can be made small.
This allows the reading resolution to be further increased.

The laser beam scanning system 13b is mainly composed of a main scanning section and a sub scanning section. The main scanning section causes the laser beam spont to scan one line on the spatial light modulation element 10. The sub-scanning section scans the laser beam spot in a direction perpendicular to the main-scanning direction.

That is, when one line of main scanning is completed, the spot is moved to the next line. In this way, the laser beam spot can be two-dimensionally scanned over the spatial light modulator 10 by the main scanning section and the sub-scanning section.

The main scanning section includes a hologram scanner, a rotating polygon mirror, an ultrasonic deflector, a galvanometer, or 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 10.

The light receiving element 13d can be composed of a high speed photodiode. If the laser beam is shaped like a slit extending in the sub-scanning direction in order to read image information for several lines (in the sub-scanning direction) at once, a diode array or CCD is used as the light receiving element.
(charge-coupled device) may be used.

The dental writing system 14 includes a laser light source 14a (i3a) and a laser beam scanning system 14b (13b) shared with the digital readout system 13, and further includes a laser modulation circuit 14c.

A signal is applied from the processing unit 15 to the laser modulation circuit 14c, and the laser light source 14a (13a
) The intensity of the laser beam generated from the laser beam is modulated. When a semiconductor laser is used as the laser light source 14a (13a), direct modulation is possible by modulating its drive current, but when a gas laser is used, a modulator (not shown) is used to externally modulate the emitted laser beam. )is necessary.

The modulated laser beam is transmitted through a laser beam scanning system i4b.
(13b) and is deflected in the vertical and horizontal directions. As a result, the laser beam scans the spatial light modulation element 10 two-dimensionally. Spatial light modulator IO
The upper laser beam spot corresponds to one pixel, and its light intensity represents the gradation of the pixel.

Laser modulation circuit 14c and laser beam scanning system 14b (+
3b) operate in synchronization with each other and write a digital image into the spatial light modulation element 10 based on a signal given from the processing section 15. To handle color image information, such a writing operation is performed for R, G.

Do this for each color of B.

The analog readout system 12 uses three RSGSB light sources (
For example, fluorescent lamps) 12g, 12b, 12c
and an optical system indicated by a lens 12d. The image written on the spatial light modulator 10 is the light source 12a11.
By being sequentially illuminated with --like light from 2b and 12c, the image is enlarged and projected onto the recording paper 19 by the lens 12d.

When an R image is being written on the spatial light modulation element 10, the R light source 12a is turned on to irradiate the spatial light modulation element 10, and the recording paper 19 is exposed with the reflected light.

Similar processing is sequentially repeated for the G and H color separated images. The recording paper 19 on which the R and GSB images have been exposed in this manner is subjected to development processing to obtain a color hard copy.

Similarly to the analog writing system 11, the analog reading system 12 may also use a color filter system in addition to the light source switching system. Furthermore, instead of R, G, and B, three colors, cyan, yellow, and magenta, may be used.

The processing unit 15 is mainly composed of a computer including a microprocessor, memory, etc.
d receives the photoelectrically converted image signal and performs image processing, that is, gradation processing (gamma correction, shading correction), sharpening (sharpness emphasis), area specification (cropping,
Performs some or all digital processing such as masking), color processing (color reproduction, paint function, color extraction), movement (rotation), and editing processing (inset composition, character composition).

Note that the processing unit 15 does not necessarily need to perform any special processing. The processing results are displayed on the display 16, and the processing can be performed interactively while checking the results. The processed image signal is output to the laser modulation circuit 14c.

Note that in FIG. 1, illustration of the control section 17 shown in FIG. 2 is omitted.

FIG. 3 shows the spatial light modulator 1 which is the main component of the present invention.
(It is a sectional view showing an example of the configuration of l.

In the figure, loa and job are glass plates arranged at both ends, and an electrode 10c is laminated on the entire inside of one glass plate 10a, and a photoconductor 10d is placed inside this electrode 10c. Laminated. A thin film heater 10e and an insulating film +Of are laminated on the entire inner surface of the other glass plate 10b, and an electrode 10g is further laminated on the inside of this insulating film 101.

A spacer 10h is inserted between the electrode 10g and the conductor 10d, and a liquid crystal 10i is injected and sealed into the space formed by the electrode 10g, the conductor IQd, and the spacer 10h. For electrodes IQc and 10g, power supply 1
(lj is connected.

The electrodes lQC and log are transparent electrodes, and are preferably formed of indium tin oxide (ITO) films.

As the photoconductor 10d, cadmium sulfide (CdS),
Cadmium telluride (CdTe), selenium (Se), zinc sulfide (ZnS), bismuth silicate crystal (BSO), amorphous silicon, or an organic photoconductor is used. When dealing with color images, it is best to use amorphous silicon as the photoconductor. This is because the wavelength sensitivity of amorphous silicon is flat across visible light.

The photoconductor 10d changes the molecular orientation of liquid crystal according to the input light, and other photoconductor materials whose resistance changes depending on the light can be used.

Examples include materials that generate voltage when exposed to light (for example, solar cells), materials that generate heat when exposed to light, materials whose structure changes when exposed to light (for example, photochromic compounds), and the like. Materials that generate heat when exposed to light and materials whose structure changes when exposed to light have the ability to directly change the molecular orientation of liquid crystals without electricity.

The glass plates 10a and 10b are transparent and the liquid crystal 1
It functions as a substrate for sealing 0.

Therefore, a transparent plastic plate or a transparent ceramic plate may be used instead of the glass plate.

When the spatial light modulator is configured as a transmission type, an ITO film or the like is used as the thin film heater 1 (le).

In addition, the insulating film 10f includes silicon oxide (SiO2), silicon nitride (S i3 N4), and aluminum oxide (
A transparent film such as Al 203) is used.

A ferroelectric liquid crystal with a memory effect is used for the liquid crystal 10g.

As a general characteristic of ferroelectric liquid crystals, since the torque PsE exerted by the electric field E is used for the spontaneous polarization Ps, the response speed is extremely fast (for example, on the order of μS6C).

Examples of ferroelectric liquid crystal materials include chiral smectic C liquid crystal (SmC), mixed liquid crystal of chiral smectic C liquid crystal and non-chiral smectic C liquid crystal (SmC),
Alternatively, there is a mixed liquid crystal of chiral smectic C liquid crystal and an optically active substance.

In chiral smectic C liquid crystal, liquid crystal molecules have a layered structure, and the long axis of the molecules is inclined at a certain angle with respect to the perpendicular to the layers. In the bulk state, the long sleeve of the molecule maintains this angle and rotates in a spiral.

First, the case of thick cells will be explained.

A ferroelectric liquid crystal is homogeneously aligned and inserted between electrodes as a relatively thick cell of 10 μm or more. When a pulsed voltage is applied between such electrodes, the liquid crystal changes from an opaque state to a transparent state. This is because the helical structure is broken by the electric field, the shape of the domain becomes larger, and scattering is reduced.

The electro-optical characteristic in this case is a relatively gentle curve, and its intermediate value can be used.

If you choose a liquid crystal material with a slightly higher viscosity, you can create a memory effect, although the response speed will be slower. In order to erase the stored content, a high frequency voltage may be applied between the electrodes. This returns it to its original spiral structure.

In this way, in the case of a thick cell, it is possible to construct a spatial light modulation element capable of expressing gradation while having a memory effect. In this case, the thin film heater toe and the insulating film lot shown in FIG. 3 become unnecessary.

When using a spatial light modulation element with a thick liquid crystal cell as described above, it is controlled as follows.

Writing to the spatial light modulation element 10 is performed by projecting a planar image light or irradiating an intensity-modulated laser beam onto the photoconductor 10d constituting the image writing plane, and then writing an optical image according to the light intensity distribution. As a result, a resistance distribution occurs in the photoconductor lOd. That is, the portion of the photoconductor 10d that is exposed to light
The resistance of the photoconductor 1 decreases, and the part of the photoconductor 1 that is not exposed to light
0d remains high resistance.

In this state, when a pulsed voltage is applied between the electrodes IQc and 101, a voltage with the same distribution as the incident light intensity distribution is applied to the liquid crystal 10i, and the transparent state changes accordingly. The optical image written on the liquid crystal 101 in this manner is stored.

For reading from the spatial light modulation element 10, by irradiating the entire surface of the spatial light modulation element 10 with --like light, scattered light or reflected light modulated according to the information written at each point is obtained. By imaging this with a lens, an analog image can be read out. Furthermore, when a spot light such as a laser beam is irradiated, pixel information of that spot can be read out.

In order to completely erase the image written on the spatial light modulator 10, it is sufficient to irradiate the entire surface of the photoconductor 10d with -like light while applying a high-frequency AC voltage between the electrodes 10c and 101.

To partially erase an image written on the spatial light modulator 10, a laser beam with a constant light intensity is applied to the portion of the photoconductor 10d to be erased while a high-frequency AC voltage is applied between the electrodes 10c and 10g. Uniform irradiation by two-dimensional scanning.

Next, the case of a thin cell will be explained.

When a ferroelectric liquid crystal with an extremely thin cell thickness is inserted between electrodes, it has a memory effect and exhibits bistable operation.

That is, by homogeneously aligning the SmC" liquid crystal,
The cell is inserted between electrodes with an extremely thin cell thickness of 3 μm or less (generally 3 μm or less). With this configuration, a helical structure cannot be formed due to the influence of planar orientation, and the inclination angle of the long axis of the molecule can only take two values (10, -0).

When a DC electric field 1E is applied to the cell in this state, the spontaneous polarization Ps of the liquid crystal matches the direction of the electric field 1E, and all the liquid crystal molecules are aligned in the +θ direction.When an electric field -E is applied, all the liquid crystal molecules are - Align in the direction of θ. In other words, by switching the polarity of the electric field, the liquid crystal molecules are oriented in one of two directions, 10 and -θ, making it possible to create a bistable state.

Further, even if the electric field is removed, the molecular orientation state does not change because it has a memory effect due to the influence of planar orientation.

Such thin cells are expected to be applied to large display elements with a large display capacity.

In order to apply it to a spatial light modulator, it is necessary to express intermediate tones. In other words, it is important how to express halftones while creating a memory effect.

FIG. 4 shows the electro-optical properties of a ferroelectric liquid crystal in a thin cell.

As shown in the figure, the curve is steep and therefore bistable operation is performed. A method for expressing halftones by area gradation by controlling the threshold voltage for a ferroelectric liquid crystal having such electro-optical characteristics will be described below.

The threshold voltage depends on the torque PsE and the viscosity of the SmC liquid crystal.In other words, as the viscosity decreases, the liquid crystal molecules move more easily, so the viscosity naturally decreases.On the other hand, the spontaneous polarization Ps As the voltage increases, the driving force increases, so the liquid crystal molecules are inverted at a small threshold voltage.

Some liquid crystal materials have a temperature dependence in their spontaneous polarization Ps. By using such a liquid crystal material and applying a temperature gradient, the threshold voltage can be changed.

In order to actually provide area gradation, a matrix-like temperature distribution is provided in the liquid crystal cell to give a distribution to the threshold voltage. This is done by a thin film heater lOe.

As shown in FIG. 5, for example, the thin film heater lOe is formed in a pattern in which a plurality of micro heaters 20 are provided in parallel. Each of these microheaters 20 corresponds to a pixel, and since the pitch thereof affects the resolution, it is preferable that the pitch be small. Each micro heater 2
It is appropriate that the diameter of the 0 is 10 am or less and the pitch is 20 μm or less.

In this way, by giving a matrix-like temperature distribution to the liquid crystal using the thin film heater 10e, a threshold voltage distribution is given, and the size of the area where the liquid crystal molecules are inverted changes depending on the voltage applied to both sides of the liquid crystal. That will happen.

When using a spatial light modulation element of a thin liquid crystal cell as described above, it is controlled as follows.

Writing to the spatial light modulation element IO is carried out by projecting a plane image light onto the photoconductor 10d constituting the image writing plane.
A resistance distribution occurs at 0d. That is, the resistance of the portion of the photoconductor 10d that is exposed to light decreases, and the resistance of the portion of the photoconductor 10d that is not exposed to light remains high.

The thin film heater 10g is energized from a power source (not shown), thereby providing a temperature distribution to the liquid crystal cell.

In this state, a pulsed voltage +V is applied between the electrodes 10c and 10g. In this case, a DC voltage may be applied, but a pulsed voltage is better in consideration of the lifespan of the liquid crystal.

This voltage value V is the voltage required to invert the liquid crystal molecules in the portion that is strongly irradiated with light.

This causes an inversion of the liquid crystal molecules depending on the resistance distribution of the photoconductor 104 and the temperature distribution of the liquid crystal cell. Generally, areas that are strongly irradiated with light have a large inverted area of liquid crystal.
In areas where the light is weak, the inversion area of the liquid crystal is small. In this way, an optical image is written on the liquid crystal 101 and stored.

Writing with a laser beam is similar, and the electrode 10c
Then, one pixel is written by irradiating an intensity-modulated laser beam with a pulsed voltage +V applied between 10g and 10g. The image is then written by scanning the laser beam two-dimensionally. However, since the gradation is represented by area gradation,
One pixel must correspond to the pitch of the micro-heater 20, and the size of the laser beam spot is also adjusted to this.

Reading from the spatial light modulator 10 is performed as follows.

This method modulates light by inverting the orientation of liquid crystal molecules and changing the polarization state. Therefore, a polarizer and an analyzer (not shown) are used.

The linearly polarized light for readout that has passed through the polarizer is transferred to the electrode 10.
The entire surface of the spatial light modulator 10 is irradiated with no voltage applied between c and 10g, and the scattered light or reflected light is converted into a change in light amount through an analyzer and read out. The directions of polarization of the polarizer and analyzer are perpendicular or parallel.

Note that since the liquid crystal 10i has a memory effect, the photoconductor ]O
Even if reading light is irradiated onto the area d, the written image will not be erased.

When the entire surface of the spatial light modulation element 10 is irradiated with such polarized light, scattered light or reflected light is obtained that is modulated according to the information written at each point, which is passed through an analyzer and sent through a lens. An analog image can be read out by focusing the image. Further, by similarly irradiating a spot light such as a laser beam, pixel information of that spot can be read out.

When a liquid crystal having a memory function is used as in the present invention, writing is not performed unless both light and voltage are simultaneously applied to the photoconductor. That is, a laser beam for readout or -
Even if various types of light are irradiated onto the photoconductor, the written image will not change. Therefore, there is no need to provide a light shielding film between the liquid crystal and the photoconductor to prevent light from being applied to the photoconductor during reading, and the readout optical system can be of a transmission type. Moreover, even if the reading laser beam is applied from the glass plate 10a side or
It may be applied from the b side. Alternatively, a reflective type may be provided by providing a light shielding film.

In particular, if the configuration is such that the reading laser beam is applied from the same side as the writing laser beam, as shown in FIG.
Most of the optical system can be shared by the digital writing system and the digital reading system.

Note that in order to erase the entire image written on the spatial light modulation element 10, a pulsed voltage -
It is only necessary to irradiate the entire surface of the photoconductor 10d with --like light having a relatively strong light intensity while applying (2).

As a result, all liquid crystal molecules are aligned in the -θ direction. Note that the voltage -V in this case is a voltage sufficient to invert the liquid crystal molecules.

In order to partially erase the image written on the spatial light modulator 10, a constant relatively strong light intensity is applied to the portion of the photoconductor IQd to be erased while a pulsed voltage V is applied between the electrodes 10c and 10g. The laser beam is scanned two-dimensionally one pixel at a time to uniformly irradiate the laser beam.

Next, a description will be given of an operation of overlapping writing between an image written in analog and an image written digitally.

The digital image has no gradation and is RSG.

In the case of an image in which B is represented by approximately two values (eight colors), it is sufficient 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, it is necessary to perform partial erasure as described above in order to return the area where the digital image is to be written to its initial state.

By this partial erasure, the liquid crystal molecules of one pixel that are hit by the laser beam are oriented in the -θ direction and return to the initial state.

Thereafter, as in the case described above, writing is performed pixel by pixel by irradiating an intensity-modulated laser beam while applying a pulsed voltage +V between the electrodes IQc and 10g.

FIG. 6 is a flowchart schematically showing a part of the control program of the computer provided in the control section 17 shown in FIG. This program is for color image editing and
This is for executing the output function mode, and when this mode is specified, the computer operates as follows.

First, in step S1, a flag n for switching between R, G, and B is initially set to n4-O.

Next, in step S2, it is determined whether n==0.

If n=0, the analog write system 1 is
The R light source 11a of No. 1 is turned on, and in the next step S4,
An optical image of the original 18 by -like light from the R light source 11a is written on the spatial light modulation element 10 via the lens ILd.

If n=0 is not determined in step S2, it is determined whether n=1 in step S5.

If n=1, the G light source 11b is turned on in step S6, and the G light source 11b of the original 18 is turned on in the next step S4.
An optical image created by --like light from the above is written on the spatial light modulation element 10 via the lens lid. If n=1, then
In step S7, the B light source 11c is turned on, and in the next step S4, an optical image of the document 18 by -like light from the B light source 11c is transmitted to the spatial light modulator 10 through the lens lId.
write to.

In the next step S8, the digital readout system 13
Activate. That is, the laser beam emitted from the laser light source 13a is two-dimensionally scanned on the spatial light modulator IO, and the transmitted light, reflected light, or scattered light is transmitted to the light receiving element 13.
The image information written on the spatial light modulation element 10 is read out by applying the voltage to d.

Next, in step S9, the processing section 15 is activated,
Various image processing is performed on the read image information.

In the next step SIO, the digital writing system 14 is activated. That is, a signal from the processing section 15 is applied to the laser modulation circuit 14c, and the laser beam is modulated to two-dimensionally scan the spatial light modulation element 10 to perform writing. At the time of this digital writing, the digital image may be written on the entire spatial light modulation element 10, or may be written on a portion thereof. This makes it possible to obtain an image in which an analog image and a digital image are mixed and fused.

In step Sll, it is determined whether all image processing by the processing unit 15 has been completed, and if not, steps 88 to
The process of 510 is repeatedly executed.

In the next step 512, it is determined whether n=o. If n=0, the process advances to step S13 and the R light source 12a of the analog readout system 12 is turned on. Then, in the next step S14, the image information written on the spatial light modulation element 10 is read out using --like light from the R light source 12a, and the optical image is exposed onto the recording paper 19 through the lens 12d. .

If n=0 in step 512, step S1
5, it is determined whether n=1. n-1
In this case, the G light source 12b is turned on in step S16, and in the next step S14, the image information written on the spatial light modulation element IO is read out using --like light from this G light source 12b, and the Lens optical images! The recording paper 19 is exposed through 2d. If not nl, step 5
17, the light source 12c of B is turned on, and the next step 514
Then, the image information written on the spatial light modulator 10 is read out using the -like light from the B light source 12c, and the optical image thereof is exposed onto the recording paper 19 through the lens 12d.

Next, in step 518, n is incremented by n+n+1, and then in step 519, it is determined whether n=3. If n=3, RXG.

This program is terminated assuming that processing of all colors of B has been completed. If n=3, the process returns to step S2 and the above-described process is repeated.

When the color image editing function mode is instructed, the computer executes only steps 38 to S11 of the program in FIG. 6. However, the processing from Steps 38 to Sll is repeatedly executed for all R and GSB colors.

If the image scanner function mode is instructed, the sixth
Only steps 5l-58 of the program shown in the figure are executed. In this case as well, the process is repeated for all R, G, and B colors. That is, the process is continued until n=3.

If the printer function mode is instructed, step 520 of the program in FIG. 6 is first executed, and image information is input from the control section 17 or other external device. Next, the processing after step SlO is executed. However, these processes are repeatedly executed for all R, G, and B colors.

When the analog copy function mode is instructed, the process is executed in such a way that the program always jumps from step S4 to step St2 in the program shown in FIG.

According to this embodiment, analog processing or digital processing can be used depending on the type of image and the like. for example,
For images mainly consisting of line drawings or characters, smooth lines can be reproduced by instructing the analog copy function mode and performing analog processing.

Furthermore, for images where color is important, color correction and the like can be performed by instructing the color image editing/output function mode to faithfully reproduce the colors.

Image area separation, which is difficult with analog processing, can be easily processed by instructing the color image editing/output function mode or the color image editing function mode and performing digital processing such as partial erasure. Furthermore, it is also possible to obtain an image in which analog and digital images are mixed or fused, such as by fitting an analog image into a digital image, fitting a digital image into an analog image, or overwriting a digital image on an analog image.

Furthermore, during readout scanning from the spatial light modulation element, it is also possible to reduce the resolution in stages by coarsening the scanning interval or the sampling interval of the light receiving element. Furthermore, if the scanning interval is set closer than usual and images are displayed at normal intervals, a zoomed-in image can be obtained. By making the area of the spatial light modulation element sufficiently large, it is possible to avoid deterioration in the image quality of zoomed-in images.

This zoom-up function can be used to obtain a zoom-up image of any location and any magnification without moving the document or the optical lens.

[Effects of the Invention] As explained in detail above, according to the present invention, a photoconductor constituting an image writing plane, a ferroelectric liquid crystal laminated on the photoconductor and having a memory function, and a photoconductor and Spatial light modulation is achieved by two-dimensionally scanning a laser beam over the spatial light modulation element, including a spatial light modulation element equipped with electrodes that sandwich the liquid crystal, an analog writing system that writes an original image onto the spatial light modulation element in an analog manner, and A digital readout system that digitally reads out images written on the element; a processing unit that performs image processing on the readout image data; Equipped with a digital writing system that digitally writes to the modulation element and an analog readout system that reads out the image written to the spatial light modulation element in an analog manner, it handles mixed and fused images such as analog and digital images. - It is possible to realize a low-cost image processing device that can reproduce images with high resolution and good gray reproducibility.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic structure of a color image editing/output device as an embodiment of the present invention, FIG. 2 is a block diagram schematically showing the structure of the embodiment of FIG. 1, and FIG. 4 is a cross-sectional view showing an example of the configuration of a spatial light modulator; FIG. 4 is an electro-optical characteristic diagram of a ferroelectric liquid crystal in a thin cell; FIG. 5 is a plan view of a thin film heater in the spatial light modulator of FIG. FIG. 6 is a flowchart schematically showing a part of the computer control program of the embodiment shown in FIG. 10...Spatial light modulation element, IOa, 10b
...Glass plate, IOc, lOg...
・Electrode, lOd...Photoconductor, 10e...
・・Thin film heater, 101・・・Insulating film, IOh・
...Spacer, 101...LCD, 10i
...Power supply, 11...Analog writing system, lla % jib % llc 112a z
12bs 12cm-light source, Ild, 12d,
13c -=- Lens, 12... Analog readout system, 13... Digital readout system, 13
a, 14a----Laser light source, 13b,
14b... Laser beam scanning system, 13d...
・Light receiving element, 14...Digital writing system, 14
c... Laser modulation circuit, 15... Processing section, 16... Display, 17...
Control unit, 18... Original, 19... Recording paper, 20... Micro heater. Figure 2

Claims (1)

[Claims] A spatial light modulator comprising a photoconductor constituting an image writing plane, a ferroelectric liquid crystal laminated on the photoconductor and having a memory function, and electrodes sandwiching the photoconductor and the liquid crystal; There is an analog writing system for analog writing on the spatial light modulation element, and two laser beams on the spatial light modulation element.
A digital readout system that digitally reads out the image written on the spatial light modulation element by dimensional scanning; a processing unit that performs image processing on the read image data; An image characterized by comprising: a digital writing system for digitally writing the image data subjected to the above into the spatial light modulation element; and an analog readout system for reading out the image written on the spatial light modulation element in an analog manner. Processing equipment.