JPH05203901A - Image forming device - Google Patents

Abstract

PURPOSE:To enable an image processing on an optical image memory and to shorten the occupancy time of a host computer by providing an area erasing and a rewriting means on the side of an image forming device. CONSTITUTION:When an image erasure instruction wherein an area is specified is sent from the host computer HC, a central control part 40 fetches the instruction from an interface part IF and positions the area to be erased by using a rotary encoder 3 and a linear encoder 35. Then a liquid crystal cell control part 45 is set in an image pixel unit erasuring state. When an image write instruction wherein an area is specified is sent from the host computer HC, the central control part 40 fetches the instruction from a positioning part IF and positions the area for writing by using the rotary encoder 3 and linear encoder 35. Then the liquid crystal cell control part 45 is set in an image writing state. Consequently, the image processing for image erasure or rewriting using image data on a liquid crystal cell is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for writing image data into an optical image memory by beam light, reading the written image and printing the image, and more particularly to an optical image memory by writing and erasing in the optical image memory. The image processing means described above.

[0002]

2. Description of the Related Art A display in which a liquid crystal cell is selectively irradiated with laser light to display an image on the liquid crystal cell is disclosed in US Pat. No. 3,996,999. This is one in which the heat of the laser light is used to partially change the phase of the liquid crystal, and an image is formed according to the irradiation pattern of the laser light. The liquid crystal used is, for example, a smectic liquid crystal.

Further, Japanese Patent Application Laid-Open No. 64-20773 discloses an apparatus for forming an image by using the above-mentioned heat writing liquid crystal cell. According to it, a latent image is formed on the photosensitive material by irradiating the photosensitive material with the transmitted light or the reflected light of the liquid crystal cell,
An image can be formed based on the latent image. And 3
Equipped with a liquid crystal cell, R (red), G
The primary color images of (green) and B (blue) are written, and the three types of images are combined to form a full-color image.

[0004]

In the case of performing form overlay (standard format printing) in an image forming apparatus, such as a printer, which employs the above-mentioned configuration, the host side is provided despite having an optical image memory on the printer side. The calculation was performed on the computer side, and it was sent to the printer side as an already completed image.

Further, even when overlaying (overlapping printing) a plurality of images, all processing is performed on the host computer side, and data is transmitted to the printer side as an already completed image. Therefore, the host computer side has to deal with a large amount of image data, resulting in an increase in the occupation time for printing. Furthermore, even though the printer has an optical image memory, its superiority has not been fully demonstrated.

The present invention has been made in consideration of the above circumstances, and an object thereof is to provide an image forming apparatus having an image processing means using an optical image memory.

[0007]

According to the present invention, there is provided an optical image memory capable of storing image data which is optically recognizable and which can be repeatedly read out, and a writing means for writing the image data into the optical image memory by means of beam light. And an erasing means for erasing the image data already written, if desired,
Position confirmation means for confirming the position in the optical image memory of the image data erased by the erasing means, and control means for controlling the writing means for writing the image data only in the position of the optical image memory confirmed by the position confirmation means. An image forming apparatus comprising:

[0008]

The erasing means erases the image data that has already been written as desired. Thereafter, the control means controls the writing means to write the image data in the optical image memory at the position confirmed by the position confirming means. By this procedure, image processing on the optical image memory becomes possible and the occupation time of the host computer can be shortened.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments. FIG. 1 is a schematic block diagram of a printer using a liquid crystal cell, which is an optical image memory, as an intermediate memory for image data, which is an embodiment of the present invention. The printer is its main unit 1
A semiconductor laser 2, a rotary encoder 3, a motor 4, a main scanning mirror 5, a liquid crystal cell 6, a lamp 7, and a filter 8 are arranged on the upper right side of the. A mirror 9 is arranged on the upper left side. The media sheet 24 is supplied by the media sheet cassette 26 and loaded in the media cassette holder 29 of the main body 1.

Preferred liquid crystal cells include a liquid crystal cell exhibiting a smectic C phase and a liquid crystal cell utilizing a nematic cholesteric mixed liquid crystal. Furthermore, this liquid crystal cell has a structure in which a heat storage layer is laminated on liquid crystal (for example,
U.S. Pat. No. 3,796,999) and an optical writing type device in which a photoconductive layer is laminated (see, for example, JP-A-49-10036 and JP-A-49-10037). The liquid crystal cell may be either a reflective cell or a transmissive cell. These liquid crystal cells can hold images once stored for several hours to several tens of days even if they are left as they are.

The media sheet 24 is, for example, Japanese Patent Laid-Open No. 59-59.
A full-color type light and pressure sensitive sheet disclosed in Japanese Patent Application Laid-Open No. -30537, which comprises (1) a microcapsule in which a photocurable material that is sensitive to red light and a dye that develops cyan are enclosed;
(2) Microcapsules containing a photo-curable material that is sensitive to green light and a dye that develops magenta, and (3) a microcapsule that contains a photo-curable material that is sensitive to blue light and a dye that develops yellow. The microcapsules of are uniformly dispersed and dispersed on the sheet.

The media sheet 24 is wound inside the media sheet cassette 26 as a media supply roll 27 in a state in which the outside light is blocked. On the other hand, the used media sheet 2 is stored in the media sheet cassette 26.
A take-up shaft for winding 4 is prepared, and the used media sheet 24 has a media discharge roll 28 on the take-up shaft.
Is rolled into a roll. The central axis of the media supply roll 27 is connected to the supply shaft 23 when the media sheet cassette 26 is loaded in the main body 1. On the other hand, the central axis of the media discharge roll 28 is such that the media sheet cassette 26
It is connected to the take-up shaft 25 when it is loaded into. The media sheet 24 is transported through the transport path by an operation after loading the media sheet cassette 26, and is wound around the media discharge roll 28. An exposure plate 10, an automatic conveyance roller 11, a buffer roller 12, and pressure rollers 13 and 14 are arranged along the conveyance path of the media sheet from the media supply roll 27 to the media discharge roll 28. On the lower right side,
A cassette 15 is provided, and the cassette 15 stores an image receiving sheet 16 coated with a developing material that develops a color by reacting with each of the dyes and a thermoplastic resin. A feeding roller 17 and a timing roller 18 are provided on the conveyance path of the image receiving sheet 16 from the cassette 15 to the pressure developing unit 22. The glossing device 1 is provided on the left side of the pressure developing unit 22.
9 is provided, a paper discharge roller 20 is arranged on the left side thereof, and a paper discharge portion 21 is provided on the upper portion of the main body 1.

First, a method for loading a media sheet will be described. The user needs to replace the media sheet cassette 26 and load the media sheet 24 when the printer is used for the first time and when the media sheet 24 in the media sheet cassette 26 that has been used is used up. For loading the media sheet 24, an operation for automatically loading the media sheet 24 after loading the media sheet cassette 26 into the main body 1 is prepared, and the leading end of the media sheet 24 can be easily loaded automatically. In order to facilitate the automatic loading operation, an autoload sheet 30 which is somewhat stiffer than the media sheet 24 is prepared at the leading end of the media sheet 24 (FIG. 2).

The user pulls out the media cassette holder 29 from the main body 1, loads the media sheet cassette 26, and mounts the auto load sheet 30 on the automatic transport roller 11 by a predetermined method, and then the media cassette holder 29.
Is loaded into the main body 1. After that, the media sheet 24 is automatically loaded by the operation key. The automatic loading operation starts by moving the buffer roller 12 to the automatic load position K so that the automatic load sheet 30 can easily pass through.

Next, the automatic load roller 30 sends the auto load sheet 30 to the pressure developing section 22. Pressure roller 1
The auto load sheet 30 that has passed between 3 and 14 is sent in the direction of the media discharge roll 28 by the media sheet changing plate 32. An adhesive tape is attached to the media discharge roll 28 in order to wind the auto load sheet 30, and the sent auto load sheet 30 is wound around the media discharge roll 28 with the adhesive tape. At this time, the pressure rollers 13, 14 and the winding shaft 25 are rotated in the forward direction to assist the winding of the auto load sheet 30.
After the auto load sheet 30 is wound around the media discharge roll 28, the auto load sheet 30 is wound, and the winding is continued for a predetermined time until the media sheet 24 is loaded. Finally, the buffer roller 12 is moved to the home position H. Thus, the automatic loading operation of the media sheet 24 is completed, and the printing operation can be started.

On the other hand, the media information 30a such as the photosensitivity of the media sheet 24 and the lot number is printed on the auto load sheet 30 (FIG. 2), and the information is read by the photo sensor at the time of auto loading and is non-volatile. The storage device (EEPROM or the like) stores the information as media information. FIG. 3 shows the configuration of the control mechanism of this embodiment.

In the figure, IF is an interface unit which receives image data (image data) from a host computer and which is used by a microcomputer, a ROM, and an RA.
Central processing unit 4 including M and input / output circuits
Enter 0. The central processing unit 40 is connected to an error detection unit 41 that detects an error such as paper jam or opening of the main body 1, a laser control unit 42 that controls the semiconductor laser 2, and a laser beam from the semiconductor laser 2. A laser scan control unit 43, an oven control unit 44 for controlling an oven for holding the liquid crystal cell 6 in a constant temperature state, a liquid crystal cell control unit 45 for controlling writing and erasing of the liquid crystal cell 6, and a key input unit 46 including a display are connected. To be done. In the above description, the central processing section 40 constitutes the control means, and the semiconductor laser 2, including the central processing section 40, the laser control section 42, and the laser scan control section 43 constitute the writing means. The central processing unit 40 and the laser control unit 42 also function as erasing means. Further, the rotary encoder 3, the linear encoder 35, and the central processing unit 40 constitute a position confirmation means. Next, the image forming operation will be described.

The image data transmitted from the host computer HC is taken in by the interface section IF of the printer and sent to the central control section 40. The central controller 40 corrects the data based on the transmitted image data and considering the photosensitivity of the media sheet 24 being used. Then, the laser control unit 42 oscillates the semiconductor laser 2 based on the corrected data. The laser beam output by the oscillation of the semiconductor laser 2 is reflected by the main scanning mirror 5 attached to the shaft of the motor 4,
The liquid crystal cell 6 is irradiated. The main scanning mirror 5 is driven by the motor 4, and its movement is controlled by the laser scan control unit 43 by a signal from the rotary encoder 3. Further, the oscillation timing of the semiconductor laser 2 is controlled by the output of the rotary encoder 3 so that it is a system in which a position shift is unlikely to occur.

On the other hand, the liquid crystal cell 6 itself is mounted on a carrier 33 as shown in FIG.
Is moved in the sub-scanning direction SS by. Linear motor 34
Is controlled by the linear encoder 35.
With the signals from the rotary encoder 3 and the linear encoder 34, the position on the liquid crystal cell 6 can be designated and necessary information can be written. There are three liquid crystal cells 6, and in the case of color printing, red, green, and blue screens are assigned to each and image data is written by the semiconductor laser 2.

At the time of reading the image data, the liquid crystal cell 6 is illuminated from the lamp 7 through the filter 8 and the media sheet 24 is illuminated with the reflected light. The liquid crystal cell 6 is illuminated through the filter 8 and the media sheet 24 is illuminated with reflected light. There are three types of filters 8, red, green, and blue, and the light from the lamp 7 is applied to each of the liquid crystal cells 6 via the filter 8 and reflected. The irradiation time of the lamp 7 is controlled by the time when the shutter 36 is empty, and the color balance of printing can be changed.

The reflected lights of red, green and blue are reflected by the mirror 9 and irradiated on the media sheet 24 on the exposure plate 10 to expose the media sheet 24. When this exposure area is X, the amount of the media sheet 24 used at one time is the length of the exposure area X plus the image-to-image distance Y. The exposure forms a selective curing latent image on the media sheet 24. The operations after the above are different between the case of multi-printing and the case of single-printing. A single print will be described as an example.

When the exposure is completed, the buffer roller 12 is moved in the direction A, and a new media sheet 24 is sent to the exposure area X. Next, the winding shaft 25 is rotated, and at the same time, the buffer roller 12 is moved in the B direction to the home position H, whereby the tip of the area where the selective curing latent image is formed is conveyed to the pressure developing point P. On the other hand, the image receiving sheets 16 are fed one by one from the cassette 15,
The timing roller 18 is conveyed by the feeding roller 17.
At that point, I stopped and was waiting.

Further, the buffer roller 12 is moved in the direction A, and a new media sheet 24 is fed to the exposure area X. Next, after the movement of the buffer roller 12 in the B direction is started, the image receiving sheet 16 waiting at the timing roller 18 is sent to the pressure developing point P in synchronism with the leading edge of the selective curing latent image. The media sheet 24 and the image receiving sheet 16 are superposed on each other just before the pressure point P and fed to the pressure point P. When the tip of the image receiving sheet 16 slightly goes out of the pressure point P, the pressure rollers 13, 1
4, the media sheet 24 and the image receiving sheet 16 are pressed in a superposed state, and in the pressed state, the pressure roller 13,
14 is rotated in the forward direction to feed the media sheet 24 and the image receiving sheet 16.

As a result, the uncured microcapsules on the media sheet 24 are destroyed, the image forming agent flows out, and reacts with the developing material on the image receiving sheet 16 to develop color. Pressurization by the pressure rollers 13 and 14 is performed until just before the trailing edge of the image receiving sheet 16. Media sheet 24 after pressure development
Is taken up by the take-up shaft 25, the image-receiving sheet 16 is heat-treated by the glossing device 19, is conveyed from the bottom to the top by the paper ejection roller 20, and is ejected to the paper ejection section 21.

On the other hand, at the end of pressure development, an unused media sheet has been sent near the pressure point P. Therefore, if the next exposure is performed as it is, the inter-image Y is taken larger than necessary and the media sheet cannot be effectively used. Therefore, the supply shaft 23 and the winding shaft 25 are reversed to move the used media sheet to the vicinity of the exposure area X. The above is the image generation operation procedure at the time of single printing of the full color printer. The image data sent from the host computer is printed by these series of operations.

Next, a method of writing / erasing the liquid crystal cell 6 will be described. FIG. 5 shows a schematic diagram of the configuration of the liquid crystal cell 6. The liquid crystal cell 6 includes two glasses 55 and 56, a transparent electrode 50 provided on the inner wall of the glass 26, an antireflection film 54 provided on the inner wall of the glass 55, and the antireflection film 5 thereof.
4, a laser absorption film 52 and a laser absorption film 52
And a transparent electrode 50 and a liquid crystal 53 enclosed between the electrodes 51.

The liquid crystal cell 6 is kept at a constant temperature of 50 ° C. in an oven (not shown) so as to easily cause a phase transition. At the time of writing image data, a voltage is applied to the electrodes 50 and 51 shown in FIG. 5 to set the direction of phase transition. Next, laser light is emitted from the back surface of the liquid crystal cell 6 by the semiconductor laser 2. The laser light is absorbed by the laser absorption film 52 and converted into heat, which raises the temperature of the liquid crystal in a range proportional to the energy of the given laser light. In other words, there is a high temperature part only where the laser beam hits. The liquid crystal cell 6 as a whole has a phase transition of 50 ° C., which is the temperature at which the phase transition occurs too much.
However, since the temperature rises in the range proportional to the energy of the laser beam applied only to the part where the laser beam hits, a phase transition occurs due to the voltage applied to that part, and that part becomes cloudy. To do.

Therefore, the amount of white turbidity of the liquid crystal 53 can be changed by changing the energy of the laser light to be given, and the gradation can be provided in the unit of one pixel. In this embodiment, the energy applied to the liquid crystal 53 is changed by changing the pulse width of the laser light in units of one pixel, and gradation is provided. The above is the procedure for writing image data in the liquid crystal cell 6.

Next, the erasing of the image data stored in the liquid crystal cell 6 will be described. In order to erase the image data on the liquid crystal cell 6 in liquid crystal units, the voltage applied to the liquid crystal may be set to a value for erasing. The value of the applied voltage varies depending on the configuration of the liquid crystal, but generally, a voltage about twice the applied voltage at the time of writing may be applied. The above-described series of operations are operations when the image processing operation is not performed on the liquid crystal cell 6. The case where an image processing operation is performed on the liquid crystal cell 6 is described above.

As described above, in the data writing in the liquid crystal cell 6, the position can be confirmed in the main scanning direction by the signal of the rotary encoder 3 connected to the main scanning mirror 5. On the other hand, in the sub-scanning direction, the position of the carriage 33 in which the liquid crystal cell 6 is mounted can be confirmed by the linear encoder 35. Therefore, the position on the liquid crystal cell 6 can be uniquely confirmed by the signals of the rotary encoder 3 and the linear encoder 35.

Next, using the flowchart shown in FIG.
Image erasing and rewriting on the liquid crystal cell 6 will be described.
When an image erasing command designating an area is sent from the host computer HC (step 100), the central control unit 40 takes in the command from the interface unit IF and uses the rotary encoder 3 and the linear encoder 35 to erase the area. Is positioned (step 101). After that, the liquid crystal cell control unit 45 is set to the image pixel unit erasing state (step 102). Next, the central control unit 40 irradiates the laser control unit 42 and the laser scan control unit 43 with a laser in an area designated by the host computer HC to raise the temperature of a part of the liquid crystal (also possible in pixel units). (Step 103). At the time of writing, the liquid crystal became cloudy due to the temperature rise caused by laser irradiation, but the liquid crystal can be made transparent depending on the voltage applied to the liquid crystal. That is, the temperature rise due to laser irradiation is only a trigger for the phase transition, and in which direction the phase transition occurs depends on the voltage applied to the liquid crystal.

The image on the liquid crystal is erased by the above means. Next, when an image writing command specifying an area is sent from the host computer HC (step 10)
4) When the central control unit 40 receives the command from the interface unit IF, the central control unit 40 uses the rotary encoder 3 and the linear encoder 35 to position the area to be written (FIG. 7) (step 105).

Thereafter, the liquid crystal cell control unit 45 is set to the image writing state pair (step 106).
Next, the central control unit 40 writes the image data to the laser control unit 42 and the laser scan control unit 43 based on the image data sent from the area designated by the host computer HC (step 107).

By the above procedure, it is possible to perform image processing such as image erasing and writing using image data on the liquid crystal cell that has already been written. As the optical image memory, the stored image can be recognized, for example, when light is irradiated, and the same image can be read out each time (unless erase is performed) even if irradiation is repeated. If Specifically, it is distinguished from a photoconductor drum in an ordinary copying machine, and is a liquid crystal, electrochromic, PLZT (Pb, La, Z
Compounds of r and Ti) are used.

[0035]

According to the present invention, the image forming apparatus has the means for erasing and rewriting the area. This means that the host computer does not have to perform all the processing of the image data on the host computer side, and the occupation time for creating the image data can be shortened. In other words, it is possible to prevent an increase in the occupied time of the host computer and prevent so-called printer throughput from decreasing.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a perspective view showing a schematic configuration of a media sheet cassette.

FIG. 3 is a block diagram showing a configuration of a control mechanism.

FIG. 4 is a perspective view showing a schematic configuration of a liquid crystal cell portion.

FIG. 5 is a vertical sectional view showing a schematic configuration of a liquid crystal cell.

FIG. 6 is a flowchart showing an operation when an error occurs.

FIG. 7 is a perspective view for explaining positioning on a liquid crystal cell.

[Explanation of symbols]

 2 semiconductor laser 3 encoder 6 liquid crystal cell 40 central processing unit 41 error detection unit 42 laser control unit 43 laser scan control unit 45 liquid crystal cell control unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location G03B 27/32 G 9017-2K G06K 15/00 H04N 1/23 103 Z 9186-5C // H04N 1 / 21 8839-5C

Claims (1)

[Claims] 1. An optical image memory that is optically recognizable and that can repeatedly store image data, and a writing unit that writes the image data to the optical image memory by means of a beam of light. To erase the existing image data, to confirm the position of the image data erased by the erasing device in the optical image memory, and to write the image data only to the position of the optical image memory confirmed by the position confirming device. An image forming apparatus comprising: a control unit that controls the writing unit.