JPH04199139A - Image forming device - Google Patents

Abstract

PURPOSE: To write the next image, for edit an image, before a cell is erased by erasing contents written in an optical image memory, after a specified time lapses after printing out. CONSTITUTION: A host computer 50 confirms that a device is in a ready state for printing, so as to issue a command. The command analyzing part of a process controller 51 analyzes the command. When the erasure of the cell is included in the command, the erasure is executed by a cell eraser 57. After that, image data is received and the image is written in a liquid crystal cell. Then, the image is formed on a medium sheet and transferred to an image reception sheet. Continuously, an MPU 71 erases the cell by the eraser 57 through an I/O driver 72, when a time-up signal is inputted by a timer 75 in which time (N) is set At this time, the time N is made moderate to reuse the image on the cell.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to an image forming apparatus that writes image data into an optical image memory using a beam of light and successively prints the written image.

(b) Conventional technology A display that selectively irradiates a liquid crystal cell with laser light to display an image on the liquid crystal is disclosed in U.S. Patent No. 3,796,999.
Disclosed in the issue. This uses the heat of laser light to partially change the phase of liquid crystal, and an image is formed according to the laser light irradiation pattern.

Note that the liquid crystal cell used is, for example, a smectic liquid crystal.

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

(c) Problems to be Solved by the Invention However, such conventional image forming apparatuses have the following problems. That is, (1) if the image written in the optical image memory is erased immediately after or before printing out, there is no time to overwrite and edit the next image in the optical image memory.

(2) If the drive power supply to the image forming device is cut off while an image has been written to the optical image memory, the next time the image forming device is driven, the new image will not have been previously written. The image is written to the optical image memory overlapping the image.

This invention was made taking these circumstances into consideration, and by improving the image erasing method of the liquid crystal cell, it is possible to easily edit images and prevent overwriting when the power is turned on. An image forming apparatus is provided.

(D) First Means for Solving the Problems This invention selectively writes image data received from an image data output means into an optical image memory using a beam of light.
In an image forming apparatus configured to print out the image on a recording medium, there is provided a timer for counting a predetermined time from the end of printing, and an erasing device for erasing the written contents of the optical image memory after the predetermined time elapses. An image forming apparatus is characterized in that it is provided with means. Further, the present invention provides image data received from the image data output means,
In an image forming apparatus configured to selectively write to an optical image memory using beam light and print out the image on a recording medium, a switch means for turning on/off supply of driving power to the image forming apparatus; An image forming apparatus characterized by comprising a detection means for detecting an off operation of the switch means, and an erasing means for erasing the contents written in the optical image memory when the switch means is turned off. .

An optical image memory is one in which the stored image can be recognized when it is irradiated with light, and the same image can be read out each time (unless it is erased) even if the irradiation is repeated. Bye. in particular,
It is distinguished from the photoreceptor drum in a normal copying machine, and includes liquid crystal, electrochromy, PLZT (Pb, L
a.

Examples include those using Zr, Ti compounds), etc.

A preferred optical image memory includes a liquid crystal cell using a liquid crystal exhibiting a smectic C phase or a nematic cholesteric mixed liquid crystal. Furthermore, the structure of this liquid crystal cell includes a liquid crystal layered with a heat storage layer (see, for example, U.S. Pat. No. 3,796,999), and an optically written device with a photoconductive layer layered thereon (for example, JP-A No. 10036 and JP-A-49-10037). The liquid crystal cell may be either a reflective cell or a transmissive cell. Even if these optical image memories are left as they are, they can retain previously stored images for several hours to several tens of days.

Examples of the beam of light for writing into the optical image memory include a laser beam from a laser diode and light from an LED. Any material that can be irradiated is sufficient.

(e) Effects Since the written contents of the optical image memory are not erased for a predetermined period of time after the printout is completed, the next image can be written thereon and the image can be edited.

When the power supply to the image forming apparatus is cut off, the detection means detects this and the erasing means erases the written contents of the optical image memory, so the next time the image forming apparatus starts to be driven. Second, double writing to the optical image memory is prevented.

(f) Embodiment FIG. 1 is a schematic configuration diagram of an image forming apparatus showing an embodiment of the present invention. This image composition device uses a photosensitive sheet (media sheet) coated with microcapsules containing a photocurable material and an image forming agent, and an image receiving sheet coated with thermoplastic Wilt, a developing material that reacts with the image forming agent to form a color. use

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 that emits a laser beam 3, a rotary encoder motor 4, a main scanning mirror 5,
A liquid crystal cell section 6, an exposure optical system 59, and a mirror 9a are provided.

The exposure optical system 59 includes an exposure lamp (for example, a halogen lamp) 7, a color filter section 8, and a lens LS.

A mirror 9b is disposed at the upper left side.

The other one is the developing unit 27 , and the media sort 24 on the left side is wound around the supply shaft 23 , transported along the transport path, and wound onto the take-up shaft 25 . From the supply shaft, along the conveyance path of the media sort 24, the exposure plate IO1
Automatic transport rollers 11, buffer rollers 12 and pressure rollers 13.14 are arranged. A cassette 15 is arranged at the lower right side, and the image receiving sheet 1 is placed in the cassette 15.
6 is stored. From the cassette 15 to the pressure developing section 22
There are feeding rollers 17,
A timing roller 18 is provided. Pressure developing section 2
A glossing device 19 is provided on the left side of the main body 2, a paper ejection roller 20 is provided on the left of the glossing device 19, and a paper ejection section 21 is provided on the upper part of the main body l.
is provided.

2 and 3 show the main part configuration of FIG. 1. FIG.

In these figures, three liquid crystal cells of the liquid crystal cell section 6,
That is, measure 1 cell 111. Second cell 112. 3rd cell 1
13 is attached to a frame +14 and supported by a liquid crystal support section 110. The liquid crystal support part 110 is an X-axis direction movement mechanism! 15 and is movable in the X-axis direction (sub-scanning direction) shown by the arrow, and this movement is accurately performed by a linear encoder motor (a linear motor coupled with a linear encoder) 55. Above the liquid crystal support section 110 are a laser diode 2, a main scanning mirror 5, and a rotary encoder motor (a motor combined with a rotary encoder).
A writing device including 4 is arranged. When writing an image, if the mirror 5 is rotated back and forth while moving the support part 110 in the X-axis direction, the laser beam is directed to the Y-axis direction (main scanning Image writing is performed by scanning the liquid crystal cell in the direction (direction).

The color filter section 8 of the exposure optical system 59 includes a color separation filter and a shutter (not shown).

Each time the liquid crystal support part 110 moves in the X-axis direction (FIG. 2) and each liquid crystal cell reaches a predetermined position, the shutter of the color filter part 8 is opened and the surface of the liquid crystal cells l1l-113 is scanned, and the reflected light is The light is guided through the lens LS toward the exposure plate 1O to expose the media sort 24. Note that the liquid crystal cells 111 to +13 have R (red), G (green), and B
(blue) image is written. The color separation filter of the color filter section 8 selectively transmits only light of a specific color, and specifically includes an R filter that transmits red wavelengths, a G filter that transmits green wavelengths, and a blue wavelength filter. It consists of three types of B filters that transmit. This filter is
When reading out the liquid crystal cell on which the R image has been written, the R filter is switched to transmit the red wavelength, and the 6
When reading out a liquid crystal cell in which an image has been written, the filter is switched to a G filter that transmits green wavelengths, and when reading out a liquid crystal cell in which eight images have been written, it is switched to a B filter that transmits blue wavelengths. Note that the R and GSB filters are mounted on a disc rotated by a motor (not shown), and a predetermined filter can be set on the optical axis of the lamp 7 through slits cut in the disc. Further, the shutter is also composed of a disc with an opening rotated by a motor (not shown), and whether the shutter is open or closed is detected by a slit cut in the disc.

When the media sort 24 on the exposure plate 10 is irradiated with red, green, and blue light reflected from the liquid crystal cell section 6 or through the lens LS and mirrors 9a and 9b, the buffer roller 12 moves in the direction of arrow A. move in the direction. A selectively cured image is formed on the media note 24 by exposure. The media sort 24 is, for example, a photosensitive pressure-sensitive sorting type compatible with full-edge paper disclosed in Japanese Unexamined Patent Publication No. 59-30537,
■Microcapsules encapsulated with a photocurable material that is sensitive to red light and an image forming agent that develops a magenta color, ■Microcapsules that are encapsulated with a photocurable material that is sensitive to the edge and an image forming agent that develops a magenta color, ■Sensitive to blue light Three types of microcapsules are uniformly dispersed and coated on a sheet: a photocurable material that produces a yellow color, and a microcapsule that contains an image forming agent that develops a yellow color.

When the exposure is completed, the winding shaft 25 is rotated to move the buffer roller 12 in the direction of arrow B, and the media note 24 on which the selectively cured image has been formed is conveyed to the pressure developing section 22.

On the other hand, the image receiving sheets 15 are fed out one by one from the cassette 16, conveyed by the feeding roller 17, and temporarily stopped at the timing roller I8 to wait. After the buffer roller 12 starts moving in the direction of arrow B, the timing roller 1 is moved in synchronization with the image on the media sheet 24.
8, one image receiving sheet 16 is transferred to the pressure developing section 2.
Send it to 2.

The media sheet 24 and the image receiving sheet 16 are passed between the pressure rollers 13, 14 in an overlapping 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. After the pressure development is completed, one media sheet 24 is wound up on the take-up shaft 25, and the image-receiving sheet (+6) is subjected to heat treatment in the glossing device 19, and then the media sheet 24 is taken up on the take-up shaft 25.
0, the paper is conveyed from the bottom to the top and is discharged to the paper discharge section 21.

FIG. 4 is a block diagram of the control circuit of the image writing and U light unit 26, and the control operation of this embodiment will be explained using this diagram.

host computer 50 to host interface 50
The image data sent via a is sent to the pixel process and the internal pixel bus B based on the result after the command sent before the actual image data is analyzed by the command innotator unit in the process controller 51. The signal is sent to the laser timing controller 52. The vixel process and laser timing controller 52 processes image data and adjusts laser on timing. In image data processing, 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. This modification algorithm is determined in order to obtain better image quality, taking into account the effects of the media sheet 24, developer unit 27, and image writing and exposure unit 26 used on the reproduced image quality. In adjusting the laser on timing, a laser drive signal S is sent to the laser driver 54 at an appropriate timing and laser on time according to image data, while adjusting the timing with a servo controller 53, which will be described later, to drive the laser diode. 2 to emit light. The laser beam emitted from the laser diode 2 is reflected by a main scanning mirror 5 attached to the shaft of a rotary encoder motor 4, and is irradiated onto a liquid crystal cell section 6. As described above, the liquid crystal cell section 6 is moved in the sub-scanning direction by the linear encoder motor 55. An image is written in the cells 111 to 113 on the liquid crystal cell unit 6 by a combination of scanning of the laser beam in the main scanning direction by the rotary encoder motor 4 and scanning in the sub-scanning direction by the linear encoder motor 55.

The positions of the rotary encoder motor 4 and the linear encoder motor 55 are monitored by a rotary encoder and a linear encoder built into each, and a servo controller 53 performs drive control necessary for image writing based on this position information. Also, each encoder (
The position information obtained from the rotary and linear sensors is also sent to the vixel process and laser timing controller 52 and used to control the on-timing of the laser diode 2.

The image information written on the liquid crystal cells 111 to 113 is read out by the exposure optical system 59, and the media sheet 24 is irradiated with light containing the image information.

In other words, the five exposure optical systems are connected to the process controller 51.
In response to a signal from the exposure lamp 7, the light from the exposure lamp 7 is irradiated onto the liquid crystal cell section 6 via the color filter section 8, and the reflected light is guided onto the media sort 24 via the lens LS.

The liquid crystal cell used in this example is a reflection type cell using laser thermal writing, as shown in cross section in FIG. The liquid crystal cell used in the laser thermal writing method is particularly called a liquid crystal light valve, and consists of two cells sandwiching a smectic liquid crystal layer 6a.
A transparent electrode 6e is formed on the entire inner surface of the glass substrate 6f. A laser beam absorption layer 6d is formed on the - side substrate. When a liquid crystal cell is irradiated with a laser beam focused to about 10 microns, the absorption layer 6d absorbs the laser beam and generates heat. When the heat is transmitted to the liquid crystal layer 6u, only the portion 6h irradiated with the laser beam becomes smectic ( The phase changes from the S) phase to the nematic (N) phase and then to the isotropic liquid (I) phase.

The temperature of the liquid crystal drops rapidly when the laser beam moves to another location, and the temperature of the liquid crystal decreases rapidly when the laser beam moves to another location. In the process of changing to the S phase, a light-scattering oriented structure is formed. Note that the liquid crystal cell has a liquid crystal layer 6.
It is installed in an oven 58 and its temperature is controlled at approximately 51° C. by an oven controller 56 so that it is in a smectic phase at the operating temperature of a and undergoes a phase transition to an isotropic liquid phase due to the energy of the irradiated laser beam. . The liquid crystal in the portion not irradiated with the laser beam has a transparent alignment structure, and the once-formed light-scattering alignment structure stably coexists with this transparent alignment structure. In this way, light-scattering pixels are written on the liquid crystal layer by laser beam irradiation, but the laser beam is intensity-modulated (
An image with gradation is written by scanning the liquid crystal cell while performing pulse width modulation on a pixel-by-pixel basis.

When light is projected from the opposite side to the liquid crystal cell on which an image has been written, the projected light passes through the liquid crystal layer 6a and is regularly reflected (specular reflection) on the light reflection layer 6c in the areas not irradiated with the laser beam. However, the projected light is scattered in the area irradiated with the laser beam. In this way, reflected light of a grayscale image can be obtained from the liquid crystal cell section 6. Furthermore, in order to erase an image once written on a liquid crystal cell, an operation is required to change the orientation to a completely transparent one. Image deletion is performed as follows. The light-scattering oriented structure written on the liquid crystal cell by temperature changes caused by laser beam irradiation is reoriented by the application of a high electric field above a certain threshold, returning to the initial transparent oriented structure. This operation erases the entire light scattering image on the liquid crystal cell. In this embodiment, the transparent electrode 6e is
A rectangular wave voltage of approximately ±200 V is applied to both ends of the liquid crystal layer, thereby generating a high electric field in the liquid crystal layer and erasing the entire image.

FIG. 6 is a detailed diagram of the main part of the block diagram of FIG. 4. 6th
In the figure, 51 is a process controller, 71 is an MPU that controls the operation of the entire controller according to a sequence programmed in advance in the ROM 73, 74 is a RAM used as a working memory necessary for controlling the controller, and 70 is a host computer 50. An interface controller 72 sends and receives commands and image data according to a predetermined interface protocol to the oven temperature controller 5 in accordance with instructions from the MPU 71.
6 and an I10 driver that sends control signals to the cell erase controller 57, and a timer 75 that returns a timer count up (carry) signal to the MPU 71 after a predetermined time by loading a time setting value from the MPU 71 and then starting counting. It is. The oven temperature controller 56 detects the internal temperature of the oven 58 using a thermistor 76, and controls the heater 77 to keep the oven internal temperature constant. This control temperature is the temperature at which the liquid crystal cell of the liquid crystal cell unit 6 installed in the oven 58 is kept in the smectic phase (S phase), that is, the optimum temperature for writing an image by the laser beam and erasing the image by the cell eraser 57. It is set at approximately 51'C). The cell eraser 57 erases an image by applying a rectangular wave AC voltage to both ends of the transparent electrode 6e of the liquid crystal cell section 6 in accordance with instructions from the I10 driver 72.

The AC power E supplied from outside the device is filtered through the noise filter 7.
8. The power is supplied to the DC power unit 80 via the power switch 79. The DC power supply unit 80 supplies C power to the process controller 511 oven controller 56 and others in the apparatus as required. The AC power source via the power switch 79 is also connected to a power off detector 81, which detects that the power switch 79 is turned off and sends a power off signal to the cell eraser 57. Cell eraser
57 receives AC power supply without going through the power switch 79, and its operation is guaranteed even when the power switch 79 is off.

Next, the cell erasing process of this embodiment will be explained using the flowchart of FIG. The host computer 50 confirms that the image forming apparatus is in a print ready state (step nl) and issues a command to request printing. The image forming apparatus sends the received command (step n2) to the command analysis section of the process controller 51 for analysis (step n3). If the command includes a cell erase command, the cell eraser 57 executes the cell erase prior to receiving the image data (steps n4 and n5). However, this cell erasing process prior to receiving image data is not necessarily necessary.

Subsequently, image data is received according to the print command, and the image is written into the liquid crystal cell (steps n6 to n8).

When the reception of the image data and the writing to the liquid crystal cell are completed, the image is exposed to the media sort 24.

When the exposure is completed, the process moves to a developing process, and the image-receiving sheet 16 on which the image has been formed is discharged from the apparatus, thereby completing the printing process normally (steps n9 to n12).

Then, when the printing process is completed normally, the MPU 71
sets the time N to the timer 75 and starts timing at the same time. When the measurement of time N ends, the timer 75
A time-up signal is returned to the PU71. MPU71
In response to this, the I10 driver 72 instructs the cell eraser 57 to erase the cell, and the cell erasure is executed.

Here, the value of time N is determined based on the following operational specifications of the image forming apparatus. When the operator of the host computer 50 finishes printing once and wants to be able to print the same image remaining on the cell again, if the time N is too short, the image on the liquid crystal cell will be erased before starting printing. Therefore, it is necessary to send the image data again. Therefore, it is preferable to set the time until cell erasure to an appropriate length, for example, several minutes. By doing this,
The image on the cell that was formed in the previous printing process can be used again for printing, and if the image forming device is not accessed for a long time, the state of the liquid crystal cell is forgotten, and a new image can be printed without having to erase the cell next time. It is possible to prevent printing from starting. Also, after finishing - degree printing,
If you do not want to reuse the image remaining on the cell, you can set the time to N=0. In this case, steps n4 to n5 in FIG. 7 are unnecessary, and the liquid crystal cell is always in the erased state when starting printing. Furthermore, if it is desired to print a new image immediately after the previous printing process is completed, the print command may include a cell deletion command (steps n4 and n5).

As described above, if the liquid crystal cell is automatically erased after an appropriate period of time from the end of the printing process, it is possible to save image transfer time and waste of printing costs due to the operator forgetting to erase the cell. Furthermore, by appropriately setting the time N until erasing, it is possible to realize a cell erasing function that meets the operating specifications of the device.

By the way, in this type of image forming apparatus, if the power switch of the apparatus is turned off before image erasing of the cell is performed, the following problem occurs. In other words, when the power of the device is turned off, a light scattering image is left on the cell when the liquid crystal cell is not at its operating temperature (approximately 51'C), and even when the cell is erased next time, it cannot be completely erased and the image remains. There is a risk of image offset remaining, which poses a reliability problem for the device. Additionally, if the image data remains in the absence of an operator, the confidentiality of the image data may be leaked, and there is a problem that double image writing may occur when writing the first image after the device is powered on. .

However, according to this embodiment, the power switch 79 of the device
A power off detector 81 constantly monitors the occurrence of an off state, and sends a power off signal to the cell eraser 57 when the power switch 79 is turned off. When the cell eraser 57 detects the power-off signal, it erases the light scattering image on the liquid crystal cell. Note that, as described above, since AC power is supplied to the liquid crystal cell controller 57 without going through the power switch 79, its operation is guaranteed. This eliminates the above-mentioned problems since the image is always erased when the device is powered off.

(G) Effects of the Invention According to this invention, since there is ample time between printing out and erasing the image on the optical image memory, the next image can be written in succession, and the image can be stored on the optical image memory. can be edited.

Furthermore, if the power supply to the image forming device is cut off, the image in the optical image memory is reliably erased, and the next time the image forming device is driven, only a new image can be written to the optical image memory. Therefore, it is easy to use.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing one embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams showing main parts of the embodiment shown in FIG. 1, and FIG. 4 is an explanatory diagram showing the embodiment shown in FIG. 1. 5 is a block diagram showing the control section of the liquid crystal cell, FIG.
FIG. 7 is a detailed block diagram of the main parts of the figure, and is a flowchart for explaining the operation of the embodiment shown in FIG. 2... Laser diode, 4... Rotary encoder motor, 5...
...Main scanning mirror, 6 ...Liquid crystal cell section, 7...
...Exposure lamp, 8...Color filter section, 1
6... Image receiving sheet, 24... Media sheet,
55... Linear encoder motor, 57...
...Cell Eraser. 79...Power switch, 80...DC power supply unit, 81...Power off detector. Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] 1. An image forming apparatus configured to selectively write image data received from an image data output means into an optical image memory using a beam of light and print out the image on a recording medium, An image forming apparatus comprising: a timer for measuring a predetermined time from the end of printout; and an eraser for erasing written content in an optical image memory after the predetermined time elapses. 2. In an image forming apparatus configured to selectively write image data received from an image data output means into an optical image memory using a beam of light and print out the image on a recording medium, driving the image forming apparatus. A switch means for turning on and off the supply of electric power, a detection means for detecting an off operation of the switch means, and an erasing means for erasing the contents written in the optical image memory when the switch means is turned off. An image forming apparatus comprising: