JP2543427B2 - Image processing device - Google Patents

Description

The present invention relates to an image processing device using a spatial light modulator.

[Prior Art] As a device for creating, editing, and copying full-color images,
Color copiers are known.

Color copiers are generally classified into analog type and digital type, and each has its own advantages and disadvantages.

An analog color copier exposes an optical image,
Since a color copy is created by development, it is difficult to add image processing such as color correction and gradation processing. On the other hand, in a digital color copier, an original image is converted into a digital signal by an image scanner, and a color copy is made by a printer in accordance with the digital signal. Image processing and the like can be easily performed.

Comparing the color copies made, analog color copiers have smooth image quality (resolution is
Although it is about 800 DPI), color masking (separation of black and chromatic colors) is not easy and color reproducibility is not very good.
Specifically, a black line drawing may be colored. On the other hand, a digital color copying machine is easy to color mask and has excellent color reproducibility, but it is difficult to achieve high definition.
When the resolution is increased and the number of read pixels is increased, the amount of data increases and a high-speed processor and a large-capacity memory are required, which is significantly disadvantageous in cost compared with the analog method.

From this point of view, the analog type color copier is advantageous when a large amount of copy processing is to be performed, and the digital type color copier is suitable for the production of design manuscripts where color reproducibility is important and simple printing. Be advantageous.

As described above, since the analog method and the digital method have advantages and disadvantages, respectively, the image type, the processing purpose,
It is used properly according to the purpose.

However, there is no device capable of executing a combination of excellent processing by the analog method and excellent processing by the digital method, and in order to create a high definition image quality with good color reproducibility, it is very expensive due to the digital method. It was necessary to use the device.

Furthermore, there is no device capable of mixing analog images and digital images in one screen.

Therefore, the present applicant has already proposed an image processing apparatus that can handle an image in which analog images and digital images are mixed and fused and that has high resolution and excellent color reproducibility (Japanese Patent Application No. Hei 10 (1999) -135242). No. 1-335304, filed on December 25, 1991).

This image processing apparatus is an analog writing system for writing a reflected image obtained by illuminating an original with a light source in an analog writing system on a spatial light modulating element using liquid crystal, and a spatial light modulating element by two-dimensionally scanning a laser beam. A digital reading system that digitally reads the image written in the image, a processing unit that performs image processing on the read image data, and the image data that has been subjected to the above-described processing by two-dimensionally scanning the laser beam to the spatial light modulator. It is provided with a digital writing system for writing digitally and an analog reading system for reading out the image written in the spatial light modulator in an analog manner.

[Problems to be Solved by the Invention] In this type of image processing apparatus, when a reflected image from a document is written in an analog spatial light modulator in an analog manner, the amount of reflected light is significantly different due to the difference in paper quality and color of the document. Will end up. Therefore, it is extremely difficult to always record an image with good contrast in the spatial light modulator, and as a result, it is difficult to always obtain a high quality image.

Therefore, it is an object of the present invention to provide an image processing apparatus which can always obtain a high quality image regardless of the type of original.

[Means for Solving the Problems] A first aspect of the present invention that achieves the above object is to provide a spatial light modulator having an image writing plane and an image obtained by irradiating an original with light. An analog writing system for writing in the modulator in an analog manner, a digital reading system for digitally reading the image written in the spatial light modulator by two-dimensionally scanning a laser beam on the spatial light modulator, and a read image A processing unit that performs image processing on data, a digital writing system that digitally writes an image in a spatial light modulator based on image data that has been subjected to the above-described processing by two-dimensionally scanning a laser beam, and a spatial light modulator Spatial light modulation by an analog readout system that reads out the image written in the analog It is provided with a detection means for detecting the brightness of the image written in the element and a means for adjusting the input sensitivity of the spatial light modulation element according to the output of the detection means.

A second aspect of the present invention that achieves the above object is to provide a spatial light modulation element having an image writing plane, and an analog that writes an image obtained by irradiating a document with light to the spatial light modulation element in an analog manner. A writing system, a digital reading system that digitally reads an image written in the spatial light modulation element by two-dimensionally scanning a laser beam on the spatial light modulation element, and a processing unit that performs image processing on the read image data. And laser beam 2
A digital writing system that digitally writes an image to the spatial light modulation element based on the image data that has been subjected to the above-described processing by dimensional scanning, and an analog read that reads the image written in the spatial light modulation element in an analog manner. System, detecting means for detecting the brightness of the image written in the spatial light modulator by the analog writing system, and means for adjusting the intensity of the light applied to the original according to the output of the detecting means. Especially.

[Operation] By irradiating a document with light, an image of the document is imaged on the image writing plane of the spatial light modulator and written in an analog manner. The average brightness of the written image is detected, and the input sensitivity of the spatial light modulator is adjusted according to the detected brightness, or the intensity of the light applied to the document is adjusted. As a result, an image having a constant contrast is always recorded on the spatial light modulator. The image written in the spatial light modulator in this manner is digitally read out for each pixel by the two-dimensionally scanned laser beam. Then, the read image data is digitally rewritten in the spatial light modulator by the two-dimensionally scanned laser beam after the desired image processing. Finally, the image is read out from the spatial light modulator in an analog manner.

Embodiments 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 / outputting 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. Shows.

The digital read system 13 and the digital write system 14 are
It is electrically connected to a processing unit 15 that performs various image processing. A display 16 and a control unit 17 are connected to the processing unit 15.

The control unit 17 is mainly composed of a computer, and has the above-mentioned analog writing system 11 and analog reading system.
12, digital read system 13, and digital write system 14
Is electrically connected to In FIG. 2, white arrows represent an optical image by analog, black arrows represent an optical image by digital, and a broken line represents an electrical signal.

A contrast control system 20 that controls the contrast of the spatial light modulator 10 is further connected to the spatial light modulator 10 and the control unit 17. The contrast control system 20 is provided with a detection means for detecting the brightness of the optical image written in the spatial light modulation element 10 and a means for adjusting the input sensitivity of the spatial light modulation element 10.

The spatial light modulation element 10 changes the transmittance distribution, the reflectance distribution, or the phase distribution according to the spatial intensity distribution (optical image) of the input light, so that the intensity distribution of the light, that is, the image Can be stored temporarily. When the spatial light modulation element storing the image is irradiated with other light, the transmitted light, the reflected light, the reflected light, or the like depending on the stored two-dimensional (spatial) image information.
Alternatively, the scattered light is modulated. By detecting or exposing the modulated transmitted light, reflected light, or scattered light, the written image is read.

The spatial intensity distribution of the light input to the spatial light modulator 10 may be an analog image which is an optical image, or a digital image which is obtained by two-dimensionally scanning a modulated laser beam. . Further, when reading from the spatial light modulation element 10, uniform light may be applied to the spatial light modulation element 10 to obtain an analog image, or a laser beam having a constant intensity may be two-dimensionally scanned and applied. It may be a digital image obtained by

The analog writing system 11 has a function of writing the optical image of the original image on the original document 18 into the spatial light modulation element 10.
It is mainly composed of a light source for illuminating the light source and an optical system for forming an optical image of an original image obtained by the light source on the spatial light modulator 10.

The analog reading system 12 has a function of projecting the optical image written in the spatial light modulation element 10 onto a recording paper 19 such as a photosensitive paper, and a light source for illuminating the spatial light modulation element 10 and a light source for illuminating the spatial light modulation element 10. Recording paper with the image of the spatial light modulator 10
It is mainly composed of an optical system for focusing on 19.

The digital reading system 13 has a function of reading the image written in the spatial light modulator 10 two-dimensionally with a laser beam and irradiating the image, thereby reading the image signal in time series. It is mainly composed of a scanning system and a light receiving system.

The digital writing system 14 has a function of writing a digital image in the spatial light modulation element 10 based on an image signal given from the processing unit 15, and is mainly composed of a laser light source, a laser beam scanning system, and a laser beam modulation unit. Has been done.

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. This processing unit 15
The result processed by is displayed on the display 16.

An image editing / outputting function can be obtained by combining all the above-mentioned configurations. Furthermore, an image editing function can be obtained by combining the spatial light modulator 10, the digital reading system 13, the processing unit 15, and the digital writing system 14. Also, the analog writing system 11, the spatial light modulator 10,
An image scanner function can be obtained by combining the digital reading system 13 and the digital reading system 13. Furthermore, the printer function can be obtained by combining the digital writing system 14, the spatial light modulator 10, and the analog reading system 12. Then, by combining the analog writing system 11, the spatial light modulator 10, and the analog reading 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 more specifically shows the configuration of the embodiment shown in FIG.

The analog writing system 11 shown in FIG. 2 has R (red),
Three light sources of G (green) and B (blue) (eg fluorescent lamp)
11a, 11b, 11c and the optical system represented by the lens 11d. The original document 18 is sequentially illuminated with uniform light from the light sources 11a, 11b, and 11c, so that the optical image of the original image is reduced and projected onto the writing plane of the spatial light modulator 10 by the lens 11d.

Color separation of a color image is performed in a frame sequential manner. For one original image, first, the R light source 11a is turned on, the optical image is written to the spatial light modulator 10, the image is read out, and then the G light source 11b is turned on to scan the optical image in space. After writing to the light modulation element 10 and reading the image, the same processing is performed on the B light source 11c.

In order to obtain a color separated image, there is a color filter system in addition to the above-mentioned light source switching system.

This color filter system is a system in which R, G, and B color filters are provided between the lens 11d and the spatial light modulator 10, and these are sequentially switched to obtain a color separation image. Specifically, the R, G, and B color filters are attached to, for example, a rotator and rotated to sequentially switch the color filters. In the color filter method, a white light source such as a halogen bulb is used as a light source.

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

The contrast control system 20 is for adjusting the dynamic range of the spatial light modulation element 10 according to the brightness of the image in which it is written.

That is, the quality of the image recorded on the spatial light modulator 10 is
It depends on the reflected image from the original, and if the paper quality of the original changes, the intensity of the reflected light also changes, and the reflected image with the brightness within a certain range is not always obtained. On the other hand, the spatial light modulator 10
Has a limited dynamic range. Therefore, in order to always record an image having the optimum contrast, it is necessary to recognize the brightness of the reflected image and match the dynamic range of the spatial light modulator 10 with this.

Further, information (for example, characters) written in a color similar to the original on a colored original is used for the spatial light modulator 10.
When writing to, it is sometimes required to always record an image with good contrast, even at the expense of accurate color information.

Therefore, the contrast control system 20 includes the spatial light modulator.
As the detection means for detecting the average brightness of the image written in 10, the light receiving element 20a and the lens 20b arranged so that the image writing plane of the spatial light modulation element 10 is imaged on the light receiving element 20a. Is equipped with. The light receiving element 20a is connected to the control unit 17 in FIG. 2, and the detection output thereof is sent to the control unit 17.

At least one of the light sources 11a, 11b, and 11c is turned on, and the image written in the spatial light modulation element 10 is detected by the light receiving element 20a.
Form an image on and measure the brightness of the image. In this case, in order to know the amount of light reflected by the background of the paper, the central portion of the formed image is ignored and the reflected light from the four corners of the periphery is captured. Further, the light receiving elements 20a may be arranged in an array, the image written in the spatial light modulation element 10 may be divided into a plurality of areas, and the average brightness of each area may be measured separately.

Further, the contrast control system 20, as a means for adjusting the input sensitivity of the spatial light modulation element 10, a power source 20c capable of controlling the voltage applied between the electrodes of the spatial light modulation element 10 according to the detection output of the light receiving element 20a. I have it. The control input of this power supply 20c is connected to the control unit 17 (Fig. 2),
Receive the voltage control signal formed at 17. The output of the power source 20c is connected to both electrodes of the spatial light modulator 10. In this way, the spatial light modulator 10, the light receiving element 20a, and the controller 1
A closed loop is formed between 7 and the power supply 20c.

The spatial light modulation element 10 has increased sensitivity to incident light when the voltage applied between its electrodes increases, and decreases its sensitivity to incident light when the voltage decreases. Therefore, the spatial light modulation element 10 has its dynamic range controlled by the applied voltage, and as a result, due to the above-mentioned closed loop, it is always optimal for the reflected image of the original 18 incident on the spatial light modulation element 10. It is controlled to obtain the dynamic range.

The digital readout system 13 includes a laser light source 13a and a lens 13
b, perforated mirror 13c, holographic scanner 13d,
It has a galvanometer mirror 13e, a lens 13f, and a light receiving element 13g.

The laser beam having a constant light intensity emitted from the laser light source 13a is guided to the holographic scanner 13d through the lens 13b and the perforated mirror 13c. The holographic scanner 13d scans the laser beam in the main scanning direction. After passing through the holographic scanner 13d, the laser beam is applied to the galvanometer mirror 13e and scanned in the sub-scanning direction. As a result, the laser beam scans the spatial light modulator 10 two-dimensionally.

By irradiating the spatial light modulator 10 with the laser beam, the transmitted light, reflected light, or scattered light at that point is modulated according to the image information of the pixel corresponding to the laser beam spot. This transmitted light, reflected light, or scattered light is received by the light receiving element 13g.
And is photoelectrically converted. In this embodiment, reflected light is used. This reflected light follows the opposite path of the incident laser beam. That is, the light passes through the galvanometer mirror 13e and the holographic scanner 13d, is reflected by the perforated mirror 13c, is condensed by the lens 13f, and reaches the light receiving element 13g. In this case, the holographic scanner 13d acts as a condenser lens.

In this way, the image information written on the spatial light modulator 10 can be read out in time series.

The digital writing system 14 includes a laser light source 14a and a lens 14
b, Holographic scanner 14c, Galvano mirror 14d
And a laser modulation circuit 14e.

A signal is applied from the processing unit 15 to the laser modulation circuit 14e, and the intensity of the laser beam generated from the laser light source 14a is modulated according to this signal.

When a semiconductor laser is used as the laser light source 14a,
The laser modulation circuit 14e can be directly modulated by configuring it as a circuit that modulates the drive current. When a gas laser is used as the laser light source 14a, a modulator (not shown) that externally modulates the emitted laser beam is required.
In this case, the laser modulation circuit 14e is configured as a drive circuit for the external modulator.

The modulated laser beam is applied to the lens 14b to become parallel light, and then applied to the holographic scanner 14c and the galvanometer mirror 14d to be deflected vertically and horizontally. As a result, the laser beam scans the spatial light modulator 10 two-dimensionally. Laser modulation circuit 14e
The holographic scanner 14c and the galvano mirror 14d are driven in synchronization with each other.

In this way, the image corresponding to the image data from the processing unit 15 is written in the spatial light modulator 10. The laser beam spot on the spatial light modulator 10 corresponds to one pixel, and its light intensity represents the gradation of the pixel.

The analog reading system 12 has three light sources of R, G, and B (for example, fluorescent lamps) 12a, 12b, 12c and an optical system indicated by a lens 12d. The image written in the spatial light modulator 10 is sequentially illuminated with uniform light from the light sources 12a, 12b, 12c, so that the recording paper 19 is recorded by the lens 12d.
Projected on top.

When the R image is written in the spatial light modulator 10, the R light source 12a is turned on to illuminate the spatial light modulator 10, and the recording paper 19 is exposed by the reflected light. The same process is sequentially repeated for G and B color separation images. The recording paper 19 on which the R, G, and B images have been exposed in this manner
However, a color hard copy is obtained by being developed.

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

To handle color image information, the analog writing operation, digital reading operation, digital writing operation, and analog reading operation as described above are sequentially performed for each of the colors R, G, and B. That is, each operation is repeated for R, G for G, and B for three times.

The laser light sources 13a and 14a are semiconductor lasers or He-Ne.
A gas laser such as (helium-neon) is used. Since the semiconductor laser is small, the device body can be made compact. Further, since the gas laser has good coherence, the spot diameter of the laser beam can be made small, which can further improve the reading resolution.

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

A rotary polygon mirror, an ultrasonic deflector, or a galvanometer mirror may be used instead of the holographic scanners 13d and 14c.
A holographic scanner may be used instead of the galvano mirrors 13e and 14d.

The processing unit 15 is mainly composed of a computer including a microprocessor, a memory, etc., and has a light receiving element 13e.
The image signal photoelectrically converted in is received and subjected to image processing, that is, gradation processing (gamma correction, shading correction), sharpening (sharpness enhancement), area designation (trimming,
Part or all of digital processing such as masking), color processing (color reproduction, paint function, cutout by color), movement (rotation), and editing processing (embedding composition, character composition) are performed. Note that the processing unit 15 does not necessarily have to perform special processing. The processing result is displayed on the display 16, and the processing can be performed interactively while confirming the result. The processed image signal is output to the laser modulation circuit 14e.

Note that the control unit 17 shown in FIG. 2 is omitted in FIG.

FIG. 3 shows a spatial light modulator which is a main component of the present invention.
FIG. 11 is a cross-sectional view showing one configuration example of 10.

In the figure, 10a and 10b are glass plates arranged on both side ends, an electrode 10c is laminated on the entire inner surface of one glass plate 10a, and a photoconductor 10d and a light shielding film are further provided inside the electrode 10c. 10e are sequentially stacked. The other glass plate 10b
An electrode 10f is laminated on the entire inner surface of the electrode.

A spacer 10g is inserted between the electrode 10f and the light-shielding film 10e, and liquid crystal 10h is injected and sealed in the space formed by the electrode 10e, the light-shielding film 10e, and the spacer 10g. The above-mentioned power source 20c is connected to the electrodes 10c and 10f.

The electrodes 10c and 10f are transparent electrodes, and are preferably composed of an indium tin oxide (ITO) film.

As the photoconductor 10d, cadmium sulfide (CdS), cadmium telluride (CdTe), selenium (Se), zinc sulfide (Zn
S), bismuth silicate crystal (BSO), amorphous silicon, or organic photoconductor is used. When handling color images, it is best to use amorphous silicon as the photoconductor. This is because the wavelength sensitivity of amorphous silicon is flat over the entire visible light.

The photoconductor 10d changes the molecular orientation of the liquid crystal according to the input light, and other materials of the photoconductor whose resistance changes with light can be used. For example, a material that generates a voltage by light (for example, a solar cell), a material that generates heat by light, a material that changes its structure by light (for example, a photochromic compound), and the like. The material that generates heat by light and the material whose structure is changed by light have a function of directly changing the molecular orientation of liquid crystal without using electricity.

The light shielding film 10e is provided to prevent laser light or white light from entering the photoconductor 10d when reading image information from the spatial light modulator 10. That is, when the laser light or the white light reaches the photoconductor 10d, the written information is erased by the light. As the light-shielding film 10e, an electrically insulating opaque film, for example, a dielectric mirror such as silicon monoxide (SiO) is used.

The glass plates 10a and 10b are transparent and function as substrates for sealing the liquid crystal 10h. Therefore, a transparent plastic plate or a transparent ceramic plate may be used instead of the glass plate.

In this embodiment, a liquid crystal having a hybrid electric field effect is used as the liquid crystal 10h. This liquid crystal has no memory function.

A DC voltage is applied from the power supply 20c between the electrodes 10c and 10f to charge the electrodes 10c and 10f. Then, the electrodes 10c and 10f and the power source 20c are disconnected from each other. In this state, an optical image is incident on the photoconductor 10d by projecting a planar image light or irradiating an intensity-modulated laser beam. This causes a distribution of resistance in the photoconductor 10d according to the light intensity distribution. That is, the resistance of the photoconductor 10d in the light-exposed portion decreases, and the resistance of the photoconductor 10d in the non-lighted portion remains high. As a result, a voltage according to the light intensity distribution is applied to the liquid crystal 10h, the orientation of the liquid crystal molecules is changed, and the input light image is written.

A factor that determines the degree of alignment of liquid crystal molecules is the voltage applied to the liquid crystal at each point. This voltage depends on the light intensity incident on the photoconductor 10d and the voltage supplied from the power source 20c. That is, for example, even if the intensity of the incident light changes due to the difference in the paper quality of the original document 18, an image having a constant contrast can be written by controlling the voltage supplied from the power source 20c to the liquid crystal 10h.

To erase the image written in the spatial light modulator 10, uniform light is incident on the photoconductor 10d or the electrode 10c.
And 10e should be short-circuited.

A liquid crystal having a memory function (accumulation function) may be used as the liquid crystal 10h. Examples of liquid crystals having a memory function include dynamic scattering (DS) liquid crystals, phase transfer liquid crystals, smectic A liquid crystals, and ferroelectric liquid crystals.

As an example, writing and reading operations of the spatial light modulator using the dynamic scattering (DS) liquid crystal will be described below.

When a direct current voltage or a low frequency alternating current voltage of about 100 Hz is applied to the dynamic scattering type liquid crystal, the liquid crystal undergoes dynamic scattering and becomes a white turbid state. This state is maintained and stored even if the voltage is removed. And high frequencies above the cutoff frequency (eg
When a voltage of 700 Hz) and uniform relatively strong light are applied,
The stored image is erased. This phenomenon is applied to a spatial light modulator.

Writing to the spatial light modulation element 10 is performed by applying a DC voltage or a low frequency AC voltage of about 100 Hz from the power source 20c between the electrodes 10c and 10f, and at the same time, a planar image light to the photoconductor 10d forming the image writing plane. A light image is made incident by the projection or irradiation of a laser beam whose intensity is modulated. This allows
A distribution of resistance is generated in the photoconductor 10d according to the light intensity distribution. That is, the resistance of the photoconductor 10d in the light-exposed portion decreases, and the resistance of the photoconductor 10d in the non-lighted portion remains high. As a result, a voltage according to the light intensity distribution is applied to the liquid crystal 10g, and the liquid crystal in the portion to which the voltage is applied causes a scattering phenomenon.

For reading from the spatial light modulator 10, when uniform light is applied to the entire surface of the spatial light modulator 10, scattered light or reflected light that is modulated according to the information written in each point is obtained, An analog image can be read out by forming an image with a lens. When spot light such as a laser beam is emitted, the image information of the spot can be read.

In order to erase the entire surface of the image written in the spatial light modulation element 10, it is necessary to irradiate the entire surface of the photoconductor 10d with uniform and relatively strong light while applying a high-frequency AC voltage between the electrodes 10c and 10f. Good.

When a liquid crystal having a memory function is used as the liquid crystal 10h, writing is not performed unless both light and voltage are applied to the photoconductor at the same time. That is, the written image does not change even when the reading laser beam or uniform light is applied to the photoconductor 10d. Therefore, it is not necessary to provide the light-shielding film 10e as described above between the liquid crystal 10h and the photoconductor 10d so that light is not applied to the photoconductor 10d at the time of reading, and the reading optical system should be a transmission type. You can Moreover, the laser beam for reading is the glass plate 10a.
It may be applied from the side or from the glass plate 10b side. Alternatively, a light shielding film 10e may be provided to make it a reflective type.

In particular, if the reading laser beam is applied from the same side as that for writing, most of the optical systems in the digital writing system and the digital reading system, that is, the laser light sources 13a and 14a, the holographic scanners 13d and 14 are used.
c, Galvano mirrors 13e and 14d, and lenses 13b and 14b can be shared.

FIG. 4 specifically shows the configuration of another embodiment of the present invention.

The present embodiment has substantially the same configuration as the above-described embodiment of FIG. 1, except that the configuration of the detection means for detecting the brightness of the optical image written in the spatial light modulation element 10 of the contrast control system 20 is different. Furthermore, the only difference is that the contrast control system 20 has a means for adjusting the intensity of light applied to the original instead of the means for adjusting the input sensitivity of the spatial light modulator 10.

That is, in this embodiment, the digital readout system 13 is shared as the detection means for detecting the brightness of the optical image written in the spatial light modulator 10.

The scanning interval of the laser beam by the digital reading system 13 is set large, and the brightness of the recorded image is roughly detected. Then, a representative value of brightness is extracted by calculating an average value from the sampled brightness data of each point or by obtaining a maximum value and a minimum value. In order to know the amount of light reflected by the background of the paper, the central portion of the image formed by the spatial light modulator 10 may be ignored and the laser beam may be focused and focused on the four corners of the periphery.

To increase the scanning interval of the laser beam, the light receiving element
The sampling frequency of 13g may be lowered, or the rotation speed of the holographic scanner 13d or the galvano mirror 13e may be increased.

As shown in FIG. 4, at least one of the light sources 11a, 11b, and 11c is used as means for adjusting the intensity of the light applied to the document.
A light source control circuit 20d for controlling one emission intensity is provided. The light source control circuit 20d is connected to the control unit 17 shown in FIG. 2 so that the brightness of the image written from the document 18 to the spatial light modulator 10 matches the dynamic range of the spatial light modulator 10. The emission intensity is controlled.

The method of the embodiment shown in FIG. 1 may be used to detect the brightness of the optical image written in the spatial light modulator 10 in the present embodiment. On the contrary, the method of this embodiment may be used to detect the brightness of the optical image written in the spatial light modulator 10 in the embodiment of FIG.

According to the above-described embodiment, it is possible to always obtain a high-quality image regardless of the type of original.

Therefore, it is very effective in compensating for the difference in reflectance due to the difference in the paper quality of the original document and reading information such as characters from the colored original document 18. In particular, the image of the document 18 is converted into a spatial light modulator.
When used as an analog copying machine in which data is written in 10 and projected and exposed on a photosensitive paper as it is, it can be used as a means for correcting the image written in the spatial light modulator 10.

Further, by utilizing the above-described technique of controlling the brightness of the image written from the original 18 to the spatial light modulation element 10 so as to match the dynamic range of the spatial light modulation element 10, it is intentionally different for each color image. By performing the control, an image having a color tone different from the image of the original can be written in the spatial light modulation element 10.

[Effects of the Invention] As described in detail above, according to the present invention, a spatial light modulation element having an image writing plane and an image obtained by irradiating an original with light are written in the spatial light modulation element in an analog manner. An analog writing system, a digital reading system for digitally reading an image written in the spatial light modulator by two-dimensionally scanning a laser beam on the spatial light modulator, and a process for performing image processing on the read image data. Part, a digital writing system for digitally writing an image in the spatial light modulation element based on the image data subjected to the above-described processing by two-dimensionally scanning the data beam, and an image written in the spatial light modulation element. The image written in the spatial light modulator by the analog read system that reads in analog and the analog write system Detecting means for detecting the brightness of the image, and means for adjusting the input sensitivity of the spatial light modulator according to the output of the detecting means, or for adjusting the intensity of light applied to the document according to the output of the detecting means. With the above, it is possible to always obtain a high-quality image regardless of the type of the original.

[Brief description of drawings]

FIG. 1 is a block diagram showing a color image editing / outputting apparatus as one embodiment of the present invention, FIG. 2 is a block diagram schematically showing the configuration of the embodiment of FIG. 1, and FIG. 3 is spatial light modulation. FIG. 4 is a cross-sectional view showing one structural example of the element, and FIG. 4 is a structural view showing a color image editing / outputting device as another embodiment of the present invention. 10 ... Spatial light modulator, 10a, 10b ... Glass plate, 10c, 1
0f ... electrode, 10d ... photoconductor, 10e ... light-shielding film, 10g ...
... Spacer, 10h ... Liquid crystal, 11 ... Analog writing system, 11a, 11b, 11c, 12a, 12b, 12c ... Light source, 11d, 12
d, 13b, 13f, 14b, 20b, ... lens, 12 ... analog readout system, 13 ... digital readout system, 13a, 14a ...
Laser light source, 13c …… Perforated mirror, 13d, 14c …… Holographic scanner, 13e, 14d …… Galvano mirror,
13g, 20a …… photodetector, 14 …… digital writing system, 14
e ... Laser modulation circuit, 15 ... Processing unit, 16 ... Display, 17 ... Control unit, 18 ... Original, 19 ... Recording paper, 20 ...
… Contrast control system, 20c …… Power supply, 20d …… Light source control circuit.

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Claims (2)

(57) [Claims] 1. A spatial light modulation element having an image writing plane, an analog writing system for writing an image obtained by irradiating an original with light to the spatial light modulation element in an analog manner, and on the spatial light modulation element. A digital reading system for digitally reading an image written in the spatial light modulator by two-dimensionally scanning a laser beam;
A processing unit that performs image processing on the read image data; a digital writing system that digitally writes an image in the spatial light modulator based on the processed image data by two-dimensionally scanning a laser beam; An analog reading system for reading the image written in the spatial light modulation element in an analog manner, a detection means for detecting the brightness of the image written in the spatial light modulation element by the analog writing system, and an output of the detection means And a means for adjusting the input sensitivity of the spatial light modulator according to the above. 2. A spatial light modulation element having an image writing plane, an analog writing system for writing an image obtained by irradiating a document with light to the spatial light modulation element in an analog manner, and on the spatial light modulation element. A digital reading system for digitally reading an image written in the spatial light modulator by two-dimensionally scanning a laser beam;
A processing unit that performs image processing on the read image data; a digital writing system that digitally writes an image in the spatial light modulator based on the processed image data by two-dimensionally scanning a laser beam; An analog reading system for reading the image written in the spatial light modulation element in an analog manner, a detection means for detecting the brightness of the image written in the spatial light modulation element by the analog writing system, and an output of the detection means And a means for adjusting the intensity of light applied to the original according to the image processing apparatus.