JP2661791B2 - Image forming system - Google Patents

Description

The present invention relates to an image forming system for writing image data into an optical image memory by using a light beam, and reading and printing the written image.

(B) Prior Art A display for displaying an image on a liquid crystal by selectively irradiating a liquid crystal cell with laser light is disclosed in US Pat. No. 3,796,999. This is to change the phase of the liquid crystal partially using the heat of the laser light, and an image is formed according to the irradiation pattern of the laser light. The liquid crystal cell used is, for example, a smectic liquid crystal.

Further, Japanese Patent Application Laid-Open No. Sho 64-20773 discloses an apparatus for forming an image using the above-described thermal writing liquid crystal cell.
According to this method, a latent image is formed on a photosensitive material by irradiating the photosensitive material with light transmitted or reflected by a liquid crystal cell, and an image can be formed based on the latent image. It has three liquid crystal cells, each of which has R (red), G (green), and B (blue).
Are written, and the three types of images are combined to form a full-color image.

(C) Problems to be solved by the invention However, in such a conventional image forming apparatus,
When writing a liquid crystal cell image, there is a problem that it is difficult to intentionally overwrite an image on the liquid crystal cell.

The present invention has been made in view of such circumstances, and provides an image forming system capable of arbitrarily overwriting by improving a method of writing and erasing an image in a liquid crystal cell. .

(D) Means for Solving the Problems The present invention has an image data output unit for outputting three primary color image data for forming a full color image, and an optical image memory, and has an image output from the image data output unit. Data is selectively written to the optical image memory by the beam light,
A printer for printing out the image on a recording medium, erasing means for detecting that new image data has been sent from the image data output means to the printer, and erasing contents already written in the optical image memory; Manual input means for stopping the erasing operation of the erasing means, wherein the manual input means causes a printer to overwrite a plurality of full-color images as one full-color image on a recording medium via an optical image memory. Image forming system.

An optical image memory is one that can recognize a stored image when it is irradiated with light, for example, and can read out the same image each time the irradiation is repeated (unless an erase is performed). I just need. Specifically, it is distinguished from a photosensitive drum in a normal copying machine, and includes a liquid crystal, electrochromy, PLZT (Pb, La, Zr, T
Compound (i)).

Preferred examples of the optical image memory include a liquid crystal cell using a liquid crystal exhibiting a smectic C phase and a nematic cholesteric mixed liquid crystal. Further, the configuration of this liquid crystal cell includes a liquid crystal in which a heat storage layer is laminated (for example, see US Pat. No. 3,796,999) and an optical writing type device in which a photoconductive layer is laminated (for example, JP-A-49-10036, JP-A-49-100
No. 37 gazette). The liquid crystal cell may be either a reflection type cell or a transmission type cell. These optical image memories can hold images once stored for several hours to several tens of days even if they are left as they are.

Examples of the beam light to be written into the optical image memory include a laser beam from a laser diode and light from an LED, and the like. Any material that can be irradiated may be used.

(E) Operation When new image data is sent from the image data output means to the printer, the erasing means detects this and erases the contents already written in the optical image memory. New image data is written to the optical image memory in which nothing is written. When the erasing operation of the erasing means is stopped by the manual input means, the image data is written to the optical image memory each time image data is sent from the image data output means to the printer. Can be.

(F) Embodiment FIG. 1 is a schematic configuration diagram of an image forming apparatus showing an embodiment of the present invention. In this image forming apparatus, a photosensitive sheet (media sheet) coated with microcapsules containing a photocurable material and an image forming agent, and an image receiving sheet coated with a thermoplastic resin of a developing material which reacts with the image forming agent to form a color. Used.

The image forming apparatus is mainly composed of two parts, upper and lower. One is an image writing and exposure unit 26,
On the right side, a laser diode 2 for emitting a laser beam 3, a rotary encoder motor 4, a main scanning mirror 5,
A liquid crystal cell unit 6, an exposure optical system 59, and a mirror 9a are provided. The exposure optical system 59 includes an exposure lamp 7, a color filter unit 8, and a lens LS. Note that a mirror 9b is provided at the upper left side. Another one is a developing unit 27.
The left media sheet 24 is wound around the supply shaft 23, is conveyed along the conveyance path, and is wound around the winding shaft 25. From the supply axis, along the transport path of the media sheet 24, the exposure plate 10, the automatic transport roller 11, the buffer roller 12,
And pressure rollers 13 and 14 are provided. A cassette 15 is provided on the lower right side, and the cassette 15 has an image receiving sheet.
16 are stored. A feed roller 17 and a timing roller 18 are disposed on a conveyance path of the image receiving sheet 16 from the cassette 15 to the pressure developing unit 22. A glossing device 19 is provided on the left side of the pressure developing unit 22, a paper discharge roller 20 is provided on the left side, and a paper discharge unit 21 is provided on the upper part of the main body 1.

FIG. 2 and FIG. 3 show the main configuration of FIG. In these figures, three liquid crystal cells 111, 112, and 113 of the liquid crystal cell section 6 are mounted on a frame 114, and a liquid crystal supporting section 11 is provided.
Supported by 0. The liquid crystal support 110 is an X-axis moving mechanism
It is supported by 115 and can move in the X-axis direction (sub-scanning direction) indicated by the arrow, and this movement is accurately performed by a linear encoder motor (a linear motor combined with a linear encoder) 55. A writing device including a laser diode 2, a main scanning mirror 5, and a rotary encoder motor (motor combined with a rotary encoder) 4 is disposed above the liquid crystal support 110. When writing an image, the support unit 110
When the mirror 5 is reciprocated while moving the mirror in the X-axis direction, the laser beam scans the liquid crystal cell in the Y-axis direction (main scanning direction) as shown by an arrow in the liquid crystal cell 111 in FIG. Image writing.

The color filter section 8 of the exposure optical system 59 includes a color separation filter and a shutter (not shown). LCD support 110
Is moved in the X-axis direction (FIG. 2), and each time each liquid crystal cell reaches a predetermined position, the shutter of the color filter section 8 is opened and the liquid crystal cells 11 to 13 are surface-scanned, and the reflected light is transmitted through the lens LS. To expose the media sheet 24 in the direction of the exposure plate 10. The liquid crystal cells 111 to 113 have R (red),
G (green) and B (blue) images are written. The color separation filter of the color filter unit 8 selectively transmits only light of a specific color. Specifically, an R filter that transmits a red wavelength, a G filter that transmits a green wavelength, and a blue wavelength. Of three types of B filters that transmit light. This filter is switched to an R filter that transmits a red wavelength when reading a liquid crystal cell in which an R image is written, and a G filter that transmits a green wavelength when reading a liquid crystal cell in which a G image is written. When reading the liquid crystal cell in which the B image has been written, the B filter is switched to a B filter that transmits a blue wavelength. The R, G, and B filters are mounted on a disk that is rotated by a motor (not shown), and a predetermined filter can be set on the optical axis of the lamp 7 by slits formed in the disk. The shutter is also formed of a disk with an opening that is rotated by a motor (not shown), and the opening and closing of the shutter is detected by a slit cut in the disk.

When the red, green, and blue light reflected from the liquid crystal cell unit 6 is exposed by irradiating the media sheet 24 on the exposure plate 10 via the lens LS and the mirrors 9a and 9b, the buffer roller 12 moves in the direction of arrow A. Moving. The exposure forms a selectively cured image on the media sheet 24. The media sheet 24 is, for example, a full-color photosensitive pressure-sensitive sheet disclosed in JP-A-59-30537, in which a photocurable material sensitive to red light and an image forming agent that develops cyan are encapsulated. Three types of microcapsules: capsules, microcapsules containing a photo-hardening material sensitive to green light and an image forming agent that develops magenta, and microcapsules containing a photo-curing material sensitive to blue light and an imaging agent that develops yellow. Capsules are uniformly dispersed and applied on a sheet.

When exposure is completed, take-up shaft 25 is rotated and
12 is moved in the direction of arrow B, and the media sheet 24 on which the selectively cured image is formed is conveyed to the pressure developing unit 22. on the other hand,
The image receiving sheet 15 is fed out one by one from the cassette 16, conveyed by the feed roller 17, temporarily stopped at the timing roller 18, and waits. Arrow B of buffer roller 12
After the start of the movement in the direction, the image receiving sheet 16 that has been waiting by the timing roller 18 is fed to the pressure developing unit 22 in synchronization with the image on the media sheet 24.

The media sheet 24 and the image receiving sheet 16 pass between the pressure rollers 13 and 14 in a superposed state and are pressed. As a result, the uncured microcapsules on the media sheet are destroyed, the image forming agent flows out, and the developing material on the image receiving sheet reacts to develop color. The pressure-developed media sheet 24 is taken up by a take-up shaft 25, the image receiving sheet 16 is subjected to heat treatment by a glossing device 19, conveyed from the bottom up by a sheet discharging roller 20, and discharged to a sheet discharging section 21. You.

FIG. 4 is a block diagram of a control circuit of the image writing and exposing unit 26, and the control operation of this embodiment will be described with reference to FIG.

From host computer 50 to host interface 50a
The image data sent through the process controller 51 is a command sent prior to the actual image data.
After being analyzed by the internal command interpreter, it is sent to the pixel process and laser timing controller 52 via the internal pixel bus B based on the result. In the pixel process and laser timing controller 52, processing of image data and adjustment of laser on timing are performed. In the processing of the image data, data correction is performed on the original image data sent from the host computer 50 in order to improve the color reproducibility, gradation, and other image quality of the printed image. The correction algorithm is determined so as to obtain better image quality by taking into consideration the influence of the media sheet 24, the developing unit 27, and the image writing and exposing unit 26 on the reproduced image quality. In the adjustment of the laser on timing, the laser drive signal S is transmitted to the laser driver 54 at an appropriate timing and a laser on time according to the image data while taking timing with a servo controller 53 to be described later. To emit light. The laser beam emitted from the laser diode 2 is reflected by a main scanning mirror 5 attached to the axis of a rotary encoder motor 4 and is irradiated on a liquid crystal cell unit 6. The liquid crystal cell unit 6 is moved in the sub-scanning direction by the linear encoder motor 55 as described above. By combining the scanning of the laser beam in the main scanning direction by the rotary encoder motor 4 and the scanning in the sub-scanning direction by the linear encoder motor 55, the cells 111 on the liquid crystal cell unit 6 are combined.
The image is written to .about.113. The positions of the rotary encoder motor 4 and the linear encoder motor 55 are monitored by a rotary encoder and a linear encoder incorporated therein, and the servo controller 53 performs drive control necessary for image writing based on the position information. The position information obtained from each encoder (rotary and linear) is also sent to the pixel process and laser timing controller 52, where the laser diode 2
Used to control the on-timing of the

The image information written on the liquid crystal cells 111 to 113 is read out by the exposure optical system 59, and the medium sheet 24 is irradiated with light including the image information. That is, the exposure optical system 59 receives the signal from the process controller 51 and
Is irradiated onto the liquid crystal cell section 6 via the color filter section 8 and the reflected light is guided onto the media sheet 24 via the lens LS.

The liquid crystal cell used in this embodiment is a reflection type cell formed by laser thermal writing as shown in the cross section in FIG. The liquid crystal cell used in the laser thermal writing method is particularly called a liquid crystal light valve, and has a liquid crystal cell sandwiching the smectic liquid crystal layer 6a.
A transparent electrode 6e is formed on the entire inner surface of a single glass substrate 6f. On one substrate, a laser beam absorbing layer 6d is formed. When the liquid crystal cell is irradiated with a laser beam narrowed down to about 10 microns, the absorbing layer 6d absorbs the laser beam and generates heat. When the heat is transmitted to the liquid crystal 6a, only the portion 6h irradiated with the laser beam has a smectic (S). The phase changes from a nematic (N) phase to an isotropic liquid (I) phase. The temperature of the liquid crystal drops sharply when the laser beam moves to another place, and a light-scattering oriented structure is formed in the process of changing from I phase to N phase to S phase. The liquid crystal cell is in a smectic phase at the operating temperature of the liquid crystal layer 6a, and is mounted on the oven 58 so that a phase transition occurs in the isotropic liquid phase by the energy of the irradiated laser beam. Temperature controlled to 51 ° C. The portion of the liquid crystal that is not irradiated with the laser beam has a transparent alignment structure, and the light-scattering alignment structure once formed coexists stably with the transparent alignment structure. As described above, the light scattering pixels are written in the liquid crystal layer by the laser beam irradiation, but the gradation is obtained by scanning the liquid crystal cell while modulating the intensity of the laser beam (pulse width modulation in units of one pixel). The image is written. When light is projected from the opposite side to the liquid crystal cell on which the image is written, the projected light passes through the liquid crystal layer 6a and returns directly opposite (mirror reflection) to the light reflection layer 6c in the portion where the laser beam was not irradiated. However, the projected light is scattered at the portion irradiated with the laser beam. Thus, reflected light of a grayscale image is obtained from the liquid crystal cell unit 6. Further, in order to erase the image once written in the liquid crystal cell, an operation for changing the orientation to a transparent one is required. The image is erased as follows. The light-scattering oriented structure written on the liquid crystal cell by the temperature change due to the irradiation of the laser beam is re-oriented by applying a high electric field of a certain threshold or more,
Return to the initial transparent texture. This operation erases the entire light scattering image on the liquid crystal cell. In this embodiment, the cell eraser 57 applies a rectangular wave voltage of about ± 200 V to both ends of the transparent electrode 6e, thereby generating a high electric field in the liquid crystal layer and erasing the entire image. That is,
First, when new image data is sent from the host computer 50 via the host interface 50a, the process controller 51 sends a command to the cell eraser 57 while sending the data to the laser timing controller 52, and the laser beam is sent to the liquid crystal cell section. Before irradiating 6, the entire image is erased.

On the other hand, the operation panel 60 includes a key for stopping the image erasing operation of the cell eraser 57 and a key for inputting various image forming conditions, and is connected to the process controller 51. When an operator makes a key input from the operation panel 60, the process controller 51 starts the cell eraser.
The image erasing operation of step 57 is stopped. In this case, the previously written image data of the liquid crystal cell is not erased, so that the next image data can be overwritten on the liquid crystal cell, that is, double-written. Specifically, the text data and the graphic data are stored in the host computer 50.
In the case where the text data is stored in a different file, the text data is first read out from the file storing the text data as image data, written and held in the liquid crystal cell, and then the graphic data is stored in the file storing the graphic data. The data is read out as image data and written over the liquid crystal cell. Therefore, both data can be easily synthesized by the double writing function. That is, based on the image data written in the liquid crystal cell,
A latent image representing a sentence is formed on the background of the figure, whereby an image in which the sentence is synthesized on the background is transferred onto the image receiving sheet 16.

(G) Effects of the Invention According to the present invention, it is possible to arbitrarily overwrite image data on a liquid crystal cell, so that it is possible to edit an image.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the configuration of an embodiment of the present invention, FIGS. 2 and 3 are explanatory views showing the main parts of the embodiment shown in FIG. 1, and FIG. 4 is an embodiment shown in FIG. FIG. 5 is an explanatory diagram of a main part configuration of a liquid crystal cell. 2 laser diode 4 rotary encoder motor 5 main scanning mirror 6 liquid crystal cell 7
... Exposure lamp, 8 ... color filter section, 16 ... image receiving sheet, 24 ... media sheet, 55 ... linear encoder motor, 57 ... cell eraser, 60 ... operation panel.

Claims (1)

(57) [Claims] An image data output means for outputting three primary color image data for forming a full color image, and an optical image memory, wherein the image data from the image data output means is transmitted to the optical image memory by a light beam. A printer that selectively writes and prints out the image on a recording medium;
Erasing means for detecting that new image data has been sent from the image data output means to the printer, and erasing the contents already written in the optical image memory; and manual input means for stopping the erasing operation of the erasing means. Wherein the manual input means causes a printer to overwrite a plurality of full-color images as one full-color image on a recording medium via an optical image memory.