JPH0285854A - Full color image forming apparatus - Google Patents

Abstract

PURPOSE:To form a full color image in a shortened time by providing 3 light image memories. CONSTITUTION:Image information is written in the light image memories through an image writing section 11. An image reading section 12 consists of a light source 12a, lenses 12b, 12c, mirrors 12d, 12e, and a color resolving filter 12f, and the image information is read out as reflected light, and a media sheet is exposed. The image information is fed from a scanner, a computer, and the like of external devices to the control CPU of the optical system. Image data are revolved into 3 primary colors and memorized in each area of R, G, and B as digital data, and each image information of the image memories is written in the light image memory at the time of image writing by the writing section 11 including a semiconductor laser device, thus permitting 3 primary color images to be overlaid and a full color image to be formed on the image forming area of a photosensitive body, and the area to be exposed on the whole to light from the light image memory, and accordingly, the total exposure time to be shortened, and the total image forming time to be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a full-color image forming apparatus that is equipped with an optical image memory in which images are written and read by light, and that forms a full-color image using the optical image memory.

(b) Conventional technology Image information written in an optical image memory (intermediate storage medium) made of liquid crystal, PLZT, etc. is converted into reflected light or transmitted light (image information light) by irradiating the optical image memory with light. An image forming apparatus that forms a latent image on a photoreceptor by reading the image information and exposing the photoreceptor to the image information light has been proposed (Japanese Patent Laid-Open No. 140542/1983).
. The image information written in the optical image memory can be stored for a certain period of time, and if it is written in the optical image memory, it can be read out several times to expose the photoreceptor and form an image.

Problems to be solved by the tc+ invention By the way, full-color images generally consist of cyan, magenta,
It is formed by mixing 33 basic colors of yellow. This process separates the original full-color image into the three primary colors of red, green, and blue, and then uses the complementary colors (cyan, magenta, magenta,
The image is formed by forming an image using yellow) and superimposing them as one image. However, optical image memory writes and reads image information by distinguishing between areas that transmit light and areas that scatter light, and image information that is the source of a full-color image cannot be written as is. There wasn't.

Furthermore, since a slit exposure method has been used in the past, there has been a drawback that image scanning takes time, resulting in a longer image forming time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a full-color image forming apparatus that is equipped with three optical image memories, thereby making it possible to form a full-color image using the optical image memories, and shortening the image forming time.

(d) Means for Solving the Problems This invention provides three optical image memories in which images are written and read by light, and an image in which each of three primary color images is written in the three optical image memories. It is characterized by comprising a writing means, an image succession means, and the following.

(e) Function In the full-color image forming apparatus of the present invention, three primary color images constituting a full-color image are written into each of the three optical image memories by the image writing means. and 3
The image information written in each of the optical image memories is exposed entirely by the image reading means, and guided to the same image forming area on the photoreceptor. Therefore, three primary color images are superimposed and formed in this image forming area.

The entire image forming area is exposed using the image information in the optical image memory by the image reading means.

(Example 1) In this example, a full-color media sheet is used as the photoluminescent body, and reflected light from three optical image memories is guided to a predetermined image forming area of this media sheet. do.

A full-color media sheet is disclosed in Japanese Patent Application Laid-Open No. 59-30537, for example, and is a resin sheet made of polyester or the like, on which three types of microcapsules corresponding to each of the three primary colors are uniformly dispersed and coated. It is. These three types of microcapsules are: (1) C capsules in which a photocurable material sensitive to light in the red wavelength band and a dye that develops a cyan color using a developing material (coated on an image-receiving sheet described later) are enclosed in a resin shell; M capsule in which a photocurable material that is sensitive to light in the green wavelength band and a dye that develops a magenta color when used with a developing material are encapsulated in a resin shell; ■ A dye that develops a yellow color when a photocurable material that is sensitive to light in the blue wavelength band and a dye that develops a yellow color when the developing material is used; This is a Y-capsule in which a resin shell is encapsulated. Therefore, when this media sheet is irradiated with red, green, and blue image light, Y and M
, C is cured, and a selectively cured image is formed on the entire media sheet.

The image-receiving sheet is paper coated with a thermoplastic resin and a developing material, and the developing material is a material that develops color from the dyes encapsulated in Y and MO capsules. In addition,
The dye and developing material are, for example, composed of a leuco dye and an acid that develops the color (Japanese Patent Application Laid-open No. 88739/1989, etc.).

When the media sheet on which the selectively cured image has been formed and the image-receiving sheet are stacked and pressed together, the uncured microcapsules are destroyed, and the colorless dye encapsulated flows out and is colored by the developing material of the image-receiving sheet. A colored image is formed on the image receiving sheet.

DESCRIPTION OF THE ENTIRE CONFIGURATION OF THE IMAGE FORMING APPARATUS> FIG. 1 is a schematic front view of a full-color image forming apparatus that is an embodiment of the present invention.

An optical system is arranged at the top of the image forming apparatus main body.

This optical system has an image writing section 11 and an image reading section 12. As will be described later, the image writing section 11 includes an optical image memory and a laser device for writing an image on the optical image memory.

In the optical image memory, an image is written by being irradiated with laser light from one side, and an image is read out by being irradiated with light from the other side. Further, the image successive unit 12 includes a light source 12a, lenses 12b and 12c, mirrors 12d and 12e, and a color separation filter 12f. The image writing section 11 writes image information into the optical image memory, and the image information is read out as reflected light by the image succession section 12 to expose the media sheet. These optical systems will be explained in detail later.

The lower part of the main body of the image forming apparatus is an image forming process section. A media cartridge 21 is provided in the lower central portion of the image forming apparatus main body, and is detachably attached to the image forming apparatus main body. The media cartridge 21 has a supply shaft 21a and a take-up shaft 21b, and an unused media sheet is wound around the supply shaft 21a. As mentioned above, this media sheet is compatible with full color printing. The media sheet is pulled out from the supply shaft 21a, and the shadow feed roller 22a22b
1 Exposure table 23, conveyance roller 22c, buffer roller 24
The film is then wound onto the winding shaft 21b via the pressure roller 25. The media sheet is placed in the image reading section 12 on the exposure table 23.
A selectively cured image is formed by exposure to imaging light.

This exposure is full-surface exposure, and the media sheet is stopped on the exposure table 23 after being fed out a predetermined amount from the media car 1-ridge 21. The reflected light from the entire surface of the optical image memory then exposes the entire image forming area, and the microcapsules that are exposed to the light are hardened. By performing full-surface exposure in this manner, the overall exposure time can be shortened compared to scanning exposure.

The media sheet on which the selectively cured image has been formed is pressed by a pressure roller 25 to destroy the uncured microcapsules. During this pressurization, the image-receiving sheet fed from the paper cassette 26 on the right side of the image forming apparatus body is superimposed on the media sheet, and the contents of the destroyed microcapsules (colorless dye, etc.) flow out onto the image-receiving sheet. do. In addition,
The buffer roller 24 operates to simultaneously perform exposure and pressure transfer, and its actual operation will be described later.

The image receiving sheet in the paper cassette 26 is fed by a paper feed roller 26a, and is temporarily stopped by a timing roller 26b. Then, at a predetermined timing, the timing roller 26b is
As J'1. Ru. As a result, the uncured microcapsules of the selectively cured image on the media sheet are destroyed, and the encapsulated dye flows onto the image-receiving sheet and is colored by the developing material, forming a colored image on the image-receiving sheet.

After that, the media sheet is wound up on the winding shaft 21b,
The image-receiving sheet passes through a urethral belt 28 and a glossing device 29, and then is delivered to a paper output tray 30.

The glossing device 29 includes a glossing belt 29c stretched between rollers 29a and 29b, a pressure roller 29d that presses against the roller 29b via the glossing belt 29C, and a roller 2.
It has a fan 29e facing the fan 9a. roller 29
Inside b, a heat source such as a halogen lamp is provided, and the surface temperature is maintained at more than 100 degrees. The image receiving sheet conveyed from the pressure roller 25 is conveyed along the glossing line 29c. The image receiving sheet is placed on the roller 29b and the pressure roller 29.
d, the thermoplastic resin coated on the image-receiving sheet becomes softened and covers the surface of the colored image, smoothing it and giving the colored image a glossy appearance. Kaisho No. 60259490). In addition, the heating accelerates the coloring reaction of the dye that forms the colored image (Japanese Patent Laid-Open No. 61-24495), making the image clearer.

A serrated retaining portion is provided at the end of the media sheet supply shaft 21a, and is engaged with the actuator 21d. The actuator 21d is rotated by the solenoid 21e,
When the solenoid 21e is in the OFF state, the actuator engages with the supply shaft 21a, and the supply shaft 21a is locked. Also,
When the solenoid 21e is in the ON state, the supply shaft 21a is unlocked, and the valve can be pulled out with a single stroke.

Discharge brushes 27a and 27C are provided on the upper surface of the exposure table 23. FIG. 2 is an enlarged view of this exposure platform.

The static elimination brush 27a is provided in the vertical direction in the figure at the end upstream of the exposure table 23 (with respect to the conveyance direction of the media sheet).
The static elimination brush 27b is provided at the downstream end in the vertical direction in the figure. The static eliminating brushes 27a and 27c are attached to paper guides 27b and 27d above the media sheet, respectively. With these static eliminating brushes 27a and 27c,
Static electricity generated when the media sheet is rubbed against the exposure table 23 during conveyance of the media sheet is removed. In addition, since the static eliminating brushes 27a and 27c can block stray light from entering the center of the exposure table, exposure of the media sheet due to stray light can be prevented. FIG. 3 is a block diagram of the same image forming apparatus.

This image forming apparatus includes two CPUs 41 and 51. The CPU 41 controls the media sheet conveyance system, the image receiving sheet conveyance system, the image forming process section such as the glossing device, and performs input/output control with the operation section. Control of the buffer roller 243, pressure roller 25, etc. is performed. Further, the CPU 51 controls the optical system. Image information is input to the CPU 51 from a scanner, computer, etc. external to the image forming apparatus. This image data is digital data separated into the three primary colors of red (R), green (G), and blue (B), and the CPU 51 stores the image information in the R area, G area, and B area of the image memory 52, respectively. Remember. Then, when writing the image, the image memory 5
The R and CB image information stored in 2 is written into the optical image memory by an image writing device 11 including a semiconductor laser.

Configuration of Optical System> FIG. 4 is a perspective view showing the configuration near the image writing section 11.

The image writing device 11 writes three optical image memos! J 31 R3
It has 1G and 31B. This optical image memo 1J31R
, 31G, and 31B are, for example, Smectinek liquid crystal elements.

(2) Description of Smectinok liquid crystal element FIG. 5 shows the thermo-electro-optical characteristics of this Smectinok liquid crystal element.

The Smectinek liquid crystal element is constructed by sealing Smectinek A-type liquid crystal having positive dielectric constant anisotropy between two sheets of glass (14H). The electrode surface inside the substrate is appropriately treated to align liquid crystal molecules perpendicular to the substrate surface (top left). In this state, the element becomes transparent. As the entire liquid crystal element is heated little by little, its transparency increases slightly and eventually reaches saturation (upper right). In this state, the orientation of the liquid crystal molecules in the liquid crystal element is completely random. In other words, it is in an isotropic state and is not a liquid crystal. Next, by gradually lowering the temperature of this liquid, the following two stable states are obtained.

A) When it is cooled as it is, it partially gathers in a smectinok shape with the molecules in the element ()A-It is called a uniforce luconic. As a result, the element becomes opaque (bottom left).

B) When the device is cooled while applying a sufficiently high high frequency voltage between the electrodes, the liquid crystal molecules become aligned perpendicularly to the substrate and return to the original Smectinok A state. In other words, the device becomes transparent. This is because liquid crystal molecules have a positive dielectric constant anisotropic pressure and are therefore aligned parallel to the applied electric field.

The states A) and B) above are maintained indefinitely even after the voltage applied between the electrodes is removed, provided that the ambient temperature of the liquid crystal element does not exceed the phase potential temperature T, □.

There are two ways to return from the state (F) (opaque state) to the state (T) (transparent state) in the figure.

C) After heating the liquid crystal element again to bring the liquid crystal into a liquid state, the element is cooled while applying a sufficiently high voltage between the two electrodes.

D) Forcibly return state (F) to state (T) by applying a very high voltage between the electrodes. In this case, the liquid crystal element is left at ambient temperature.

Based on the above characteristics, optically readable (transparent or opaque) information can be written and erased by selectively applying voltage and heating to the Smectinok liquid crystal element. Voltage can be selectively applied to any pixel by placing matrix electrodes on the upper glass substrate and scanning these electrodes, and heating can be applied to any pixel by using a radar beam. You can do it by doing this.

FIG. 6 shows the above-mentioned Smectisok liquid crystal element 31R.

31G and 31B. FIG. The liquid crystal element consists of two glass substrates 3a, a Smectinok liquid crystal layer 3b sandwiched between them, and a transparent electrode 3C1 liquid crystal layer 3b arranged on the left side.
It consists of an A1 reflective film 3d placed on the right side of the A1 reflection film 3d, a laser light absorption film CrzO, and an absorption film 3C placed on the right side of the A1 reflection film 3d. The transparent electrode 3C and the reflective film 3d constitute a 71-I Knox electrode as in a known liquid crystal display device,
High frequency voltage 3 with one side as a scanning electrode and the other as a signal part electrode
The electrodes are scanned by f. By doing so, the intersection of the scanning electrode and the signal portion electrode can be used as a pixel, and by controlling the signal wave applied to the electrode, an electric field can be applied to any pixel. A semiconductor laser device and a condensing lens are arranged on the right side of the liquid crystal element, and any pixel can be heated with a laser beam. Therefore, any pixel can be heated by scanning the laser beam and turning the laser beam on and off.

Light incident from the left side (reading side) is not reflected at a location where the liquid crystal N3b is in a scattering state, but reaches the A1 reflective film 3d at a location where the liquid crystal N3b is in a liquid state or a transparent state and is therefore reflected by this reflective film.

In this embodiment, the image information written in the photometric one-image memory (liquid crystal element) is read out as reflected light, but it may also be read out as transmitted light. In FIG. 71, the image writing section 11 has a semiconductor laser device 32. In FIG. The semiconductor laser device 32 receives the image information stored in the image memory 52, and emits laser light that is controlled to be on or off according to the image information G. The light emitted from the mirror 32 provided on the goniometer 32a
b, passes through a pickup lens (condensing lens) having a focusing function, and is irradiated onto optical image memories (liquid crystal elements) 31R, 31C; and 31B. The goniometer 32a is for scanning the radar beam.

A light source i is located to the right of the optical image memories 31R, 31G, and 31B.
2a, lenses 12b, 12C, color separation filter 12 [(
(a part of the image reading section) is provided. Color separation filter 21 [R filter 21fR1 which transmits light in the red wavelength range through a disc-shaped frame G filter 21fR1 which transmits light in the green wavelength range
It includes a filter 21fG and a B filter 21r-8 that transmits light in the i-color wavelength range. Color separation filter 21r
By rotating, one of the three filters faces the position of the reflected light from the optical image memory. Actually, the R filter 21f-R is opposed to the optical image memory 31R, the G filter 21f-G is opposed to the optical image memory 31G, and the B filter 2tr-B is opposed to the optical image memory 31B. Therefore, for example, when reading image information written in the optical image memory 31R, only the red wavelength band light of the reflected light passes through the color separation filter 21f and is irradiated onto the media sheet.

The optical image memories 31R, 31G, and 31B are fixed to a support stand 31, and this support stand 31 is movable along a rail 33. A linear motor 34 is used to move this support stand 31 along the rail 33, and by controlling this motor, three optical image memories 31R, 310, 31
B is made to face the irradiation part collar of the semiconductor laser device 32 and the irradiation part by the light source 12a. Note that the semiconductor laser device 32 and the light source 12a are arranged facing each other, and the irradiation part for writing image information by the semiconductor laser device 32 and
This coincides with the irradiation part for reading image information by the light source 12a. In the figure, an optical image memory 31R is located at the irradiation section.

The image information written in the optical image memories 31R, 31G, 3iI3 is stored as is for a certain amount of time. Therefore, once image information is written to the optical image memory by the semiconductor laser device 32, the light source 12a
(Image reading section) allows the information to be read out many times.

(2) Operational Description Image information is written into and read out from the optical image memories 31R, 31G, and 31B in accordance with the procedure shown in FIG. 7 or 8. The method shown in FIG. 7 is a method in which writing and reading are sequentially performed on three optical image memories, and is convenient when forming a single image. In addition, the method shown in Figure 8 is a method in which data is written to all three optical image memories and then read out sequentially; when forming multiple images, all images are read out before reading starts. Writing an image in advance and then reading it out is convenient because the readout operation can be performed at a constant cycle without being affected by the writing time.Any method may be used, but in either case Once data has been read in, that single image can be used as is for reading.

In FIG. 7, the 3-input + QA extraction of image information is performed as follows. In addition, the following (A) to (F)
represents the figure number.

First, the image ↑n information in the R area of the image memory 52 is written into the optical image memory 31R by the optical sensor 32 (A), and then the optical image memory 31R is exposed to light by the light source 12a to form an image. The information is read out (B). At this time, the R filter 12f-R is inserted into the optical path of the reflected light, and the red wavelength band light is guided to a media sheet (not shown). When the input and readout of the red image information is completed (Δ-[3), the linear motor 34 is driven to move the support base 3
1 moves and faces the optical image memory 31G7>X irradiation section. Also, at this time, the color separation filter 12[ rotates, and the G filter 12f-G is inserted into the optical path of the reflected light from the optical image memory. And write the red image information mentioned above,
Similarly to the time of reading, the image (after the image information in the G area of the image memory 52 is written into the optical image memory 31G (C)
, it is exposed and (D) the reflected light is passed through the G filter 12[-
Expose the media sheet through G. Furthermore, the support base 31 is moved and the one-color separation filter 12f is rotated, and the image information of the B area of the image memory 52 is updated to the optical image memory 31.
After being written in B (IE), it is exposed (F), and the reflected light exposes the media sheet through the B filter 12f-B.

In this way, R, G, and B image information is written into the RlG and B image memories, and the reflected light exposes the media sheet as red wavelength band light, green wavelength band light, and blue wavelength light, respectively. In response to the respective wavelengths: It is not necessary to write on the edge fg again, and by performing exposure in the order of CB-D-F), a selectively cured image can be formed on the media sheets 1 to 1.

Further, in FIG. 8, writing and reading of image information is performed as follows. The following (Δ) to (F) represent figure numbers.

First, the image information in the R area of the image memory 52 is written into the optical image memory 3LR by the V-dedicated laser device 32 (A). Then, the linear motor 34 drives the support base 31
moves to the next writing position, the optical image memory 31G.
faces the irradiation section, and similarly, when the image information of the G area of the image memory 52 is written into the optical image memory 31G, (
B), the linear motor 34 is further driven to move the support base 31, and the optical image memory 31B, which is the next machining position, faces the irradiation section, and the image information in area B of the image memory 52 is transferred to the optical image memory. 31B. In this way, the optical image memories 31R and 31G.

After the image information Y technique is written to 31B, the respective reading is performed.

The support stand 31 moves and the optical image memo 'J 31 R moves to the irradiation section, and the optical image memo 'J 31 R receives the light and 'fA1
2 a is exposed and the image information is read out (
D). At this time, the R filter 12 f -R is inserted into the optical path of the reflected light, and the red wavelength band light is guided to a media sheet (not shown). Then, the support base 31 is moved and the optical image memory 31G is moved to the irradiation section, and the color separation filter 12f is rotated, and the G filter L 2 f-G is inserted into the optical path of the reflected light from the optical image memory. Similarly to the optical image memo 'J 31 R, the optical image memory 31G is exposed (IE) and the reflected light exposes the media sheet via the G filter 12f-G. Furthermore, the movement of the support stand 31 rotates the one-color separation filter 12f, the optical image memory 31B is exposed, and (F) the reflected light is transferred to the B filter 12 [
- Expose the media sheet through B.

In this way, the mechia sheet is exposed to three primary color lights,
A selectively cured image is formed on the surface. In this method, image formation can be performed on the second and subsequent sheets by performing exposure in the order of (D-E-.F).

<Configuration of Media Sheet Conveyance Unit and 01 Production> ■ Explanation of Configuration Figure 9 is a diagram showing the configuration of the media sheet conveyance unit, and (A) to (C) of the same figure represent the configuration of media sheet 1-1, respectively.
It represents the process of Lea feeding.

Here, the exposure length on the exposure table 23 is assumed to be r.

When images are formed continuously on the main iron I, an image forming area 11 with an exposure length E is formed on the media seam 1 and J2.
, ff2... are determined in order. In other words, the image forming area! The first image is in V, 1, and the 2nd image is in image forming area C2.
Images of the gates are formed one after another. Each image forming area e1. A non-image forming area is defined between e2, . . . This non-image (
The media sheet is controlled to be transported one time so that the image forming area is at the conveyance V1-rollers 22b, 22c and pressure roller 25 positions.

Further, the area of the media sheet between the conveyance roller 22c and the pressure roller 25 is defined as a. Normally, no image is formed in this region a, so it is desirable to keep the length a as short as possible. A non-image forming area is also provided between this area a and the image forming area, and when the feeding of the media sheet s is stopped, this area is conveyed 1''-ra 22b.
, 22C1 pressure roller 25, etc., the conveyance control goggle of the media sea is operated.

Exposure table 23. The buffer roller 2.t provided downstream of the conveyance roller 22'- is movable in the directions of arrows A and B in the figure. This (hyperactivity is shown.

j) It is carried out by the drive of a motor that does not operate. Banofalola 2
4 is the home position (hereinafter referred to as +-I P
), but due to the drive of the motor 24-
Move 111 to position 1.21-2.2.4-3. Pa 2
．． The upper right side of the far roller 24 is a buffer section, and media notes are stored in the buffer section by moving the buffer cola 24 to positions 24-1, 242, and 24-3. The storage length of the media seat 1 in the buffer section varies depending on the position of the buffer t.
) 24, a state in which the Mechia sheet approximately 1 times the image forming area (full exposure length) l is accommodated (Fig. 9 (C)
): C7 Flowchart 24-1), a state in which a sheet with a nearly double image forming area (full exposure length) C is stored (Fig. 9 (D): Banoff! Roller position 24- 3
)become.

■Operation explanation Figure 11 is flowchart 1 showing the processing procedure during image formation.
・Figure 10 shows the image at the time of image formation. In this example, as shown in Figure 8,
The image information (U) of the optical image memory ＼ is read out after all the writing is done.

(Single print) When forming only one image, use
4. Carry out the process while it is in a stopped state. Figure 10 (j~)
゛ is the time chart I for single pudding 1-.

When image forming information such as the number of images to be formed (m) is input and printer [・S・I, ・chi] are operated (nl-・"12), image forming processing is performed according to the number of images to be formed (I'n). Started. 1 sheet released.
In the case of , that is, in the case of single print (n3), the process proceeds to n4, where the exposure start, the printing, and the timer T1 start are performed. The paper is fed by rotating the paper feeder 1 roller 26a to feed the image receiving sheet of the claw receptacle 26, and the fed image receiving sheet is fed by the timing roller 261.
] and stop temporarily. Exposure is controlled by the CPU 51 by '+1'J.

In n61, first, the optical image memory 31R is connected to the image reading section 1.
2, the light source 12. a is on and red image information iQ
The light is read out. At the start of this reading, a timer is started and measures a predetermined time. If the media sheet is irradiated with red image information light for a predetermined period of time (n62), the light tJ12
a, move the support stand 31, and the optical image memory 31
G to face the image reading unit 12 (n63), and as before, turn on the light source 12a and irradiate the media sheet with green image information light for a predetermined time, then turn off the light source and move the support stand 31. The optical image memory 31B is transferred to the image succession unit 1
2 (n64=n65-/n66). Furthermore, the light J l 2 a is turned on to irradiate the media sheet with blue image information light for a predetermined period of time, and the optical image memory is moved so that the optical image memory 31R faces the image reading unit 12 as before. to end the exposure process (n 67-n 6
8 = n 69 ).

This exposure process is carried out in parallel with operations such as sheet feeding. Exposure of the media sheet 1 is carried out in an area 11 shown in FIG. 9(A). The above-described exposure requires approximately t1 time, and when the exposure is completed (n5), the image-receiving sheet is superimposed on the selectively cured image formed on the media sheet 1- by the exposure and pressurized. First, at n6, the media sheet supply shaft 21c is unlocked (the solenoid 21e is turned on), and the pressure roller 25 is rotated.

Then, the media sheet is pulled by the rotation of the pressure roller 25, and is ejected from the media cartridge (not shown). Feeding out the media sheet.

is performed for the area "a+12l". When the media sheet is conveyed, the image-receiving sheet is overlapped with the image-forming area 11 and pressurized by a presser, thereby forming a colored image on the image-receiving sheet. Therefore, the image-receiving sheet is superimposed on the image forming area β1, and the timing sheet feeding starts (n8), and pressure transfer is performed. Note that timing sheet feeding is started when the timer (n4) started at the start of exposure (n7) reaches L2.

Timing paper feeding is performed by rotation of the timing roller 26b. At n71, the timing roller 26b starts rotating and a timer starts, and when the time required to feed the β-length image receiving sheet has elapsed (r+72), the timing roller stops (n73) and starts feeding the image receiving sheet 1~. It ends. After feeding the image receiving sheet held on the timing roller 26b, if the feeding is not the last one (n74), the paper feeding roller 26a is operated to feed a new image receiving sheet from the paper cassette 26. (n75).

In the case of single printing, since only one image is formed, paper feeding (n75) is not performed.

When the pressure transfer is completed, the media sheet supply shaft 21C is locked and the one-pressure roller is stopped, thereby completing single printing. At this time, the next image forming area is located on the exposure table.

(Multi-Print) FIG. 10(B) is a time chart during multi-printing. In this example, we will explain the case where multi-printing of 6 sheets is performed. When performing multi-printing, the buffer roller 24 moves to temporarily store the image forming area on which a selectively cured image has been formed in the bottom part, and while performing exposure, the media sheets in the front and back parts are sent to the pressure roller. Perform pressure transfer. Therefore, exposure and pressure transfer can proceed simultaneously, and image formation speed can be improved. In the figure, ff1l! 2... represents the area where exposure is performed during the operation or the area where the pressure roller passes. Further, the number on the right side at the end of the buffer motor drive and the pressure roller drive indicates the position of the buffer roller at the end of the operation.

Image forming conditions are input and the print switch is operated (nL
, n2), when the number of image forming sheets in is a plurality of sheets (n3
), proceed to n21, add 1 to r representing the number of exposures, and proceed to the next process according to that value.When exposing the first sheet, (n2
2-・口41) At the start of exposure, paper is fed and timer Tl is started (n42), and when exposure ends (n43)
Median-1-Unlock and buffer 1-Start moving 24 (n'44), buffer 2
4 moves in the six directions shown by the arrows in FIG.
When turned on, the media sheet supply shaft 21c is locked.
The buffer roller is stopped and conveyance of the media sheet is stopped (n45-n46). This situation! At lζ, the buffer section stores media sheets for area a and image forming area C1, and when exposing the second and subsequent sheets, pressure transfer processing is performed in parallel with the exposure processing. At step n47, when exposure starts, the pressure roller 25 is driven, and the media sheet in the buffer section is pulled and bitten by the pressure roller 25 (.As a result, the buffer roller 24 moves in the direction of arrow B. Figure 9(B)-
As shown in (C), the rotation of the pressure U-ra 25 causes the area a to
Since the portion of the image is bitten by the pressure roller and timing feeding of the image-receiving sheet is not performed, transfer is not performed.

When the sensor S1 reaches one level due to the movement of the buffer [2-ra 24 in the direction of arrow B, the rotation of the pressure roller 25 stops (
n48-/n49). At this time, the buffer section is as shown in Figure 9 (
As shown in C), one image forming area is stored. After the pressure roller stops, when the timer reaches tl, the media sheet starts to be pulled out (r+50-·n31).

As described above, Ll represents the time from the start of exposure (i147) to the end of exposure (n69) of 1 o'clock, and after the end of exposure, the buffer roller 24 moves in the direction of the arrow to pull out the media sheet.

However, in this example, the exposure and pressure transfer and the bowing operation of the media sheet by the heel roller 24 are performed alternately, and the time required for each operation is always constant. . Place for pressure transfer・a
, for a predetermined period of time from the start of the operation, that is, the image receiving stream formed from the timing roller 26b is transferred to the pressure roller 25.
It is necessary to advance the timing paper feed (feeding of the image receiving sheet I by the rotation of the timing roller 26b) by the time necessary to reach the timing. Therefore, the timing paper feed start time is based on the previous exposure start time. It is set as .

In other words, for example, a predetermined time tQ after the start of exposure for the second image.
When L has elapsed, timing paper feeding of the image receiving sheet for pressure transfer, which is performed in parallel with the exposure of the third sheet, is carried out (n
52-''n53). Note that the pressure transfer is performed with a delay from the IJ exposure process by the amount of media sheets (2 media sheets) stored in the buffer section.

One cover roller 2.1 moves in the direction of the arrow, and when the sensor S3 is turned on, the slider knob is turned to stop drawing out the media seat I. (n54-=nS5). At this time, as shown in Figure 9 (D), there are 2
The selectively hardened image of sheet 5) is stored, and at the start of the next pressure transfer (n47), the previous selectively cured image (L image) is sent and pressure transfer is performed. The image forming area where image formation is to be performed next is placed, and at the start of the next exposure (n47), that area is exposed and a selectively cured image is formed.

In this way, a buffer section is provided in the part continuous with the exposure table,
Since media sheets on which selectively cured images are formed are successively stored in this buffer section, wastage of media sheets can be prevented. In addition, since exposure and pressure transfer are performed simultaneously and the media sheet is pulled out at a relatively high speed in the meantime, there are 111 points that can shorten the overall image forming time. Furthermore, since the entire surface exposure method is applied to the exposure, there is an advantage that the exposure time itself can be shortened.

When the media sheet is pulled out after the exposure process for the number of sheets (6 sheets) is completed (Fig. 9 (E)), the pressure roller 23 is rotated in the same way as before to perform pressure transfer (
Mouth 23=n24-→n25). At this time, as shown in FIG. 9(F), the image forming area 6 is stored in the buffer portion in the image forming area where the last selectively cured image is formed. After this, as shown in FIG. 9(C), the transport roller 22'+
The paper is pulled out to the sofa part to the area a to be stored between the pressure rollers 25 (n26=n29, n30), and during this time, the paper is fed at a predetermined time and time (n27.
n28), the image-receiving sheet fed at this time is fed at the timing when the pressure roller 25 starts to be driven.
n31>, the pressure roller 25 is reached, and the final pressure transfer of the image forming area βG is performed. This pressure transfer ends when the ban flow 1a72□i reaches the HP (n32-n33), and returns to the original state as shown in FIG. 9(A).

As described above, according to this embodiment, during continuous image formation, the media sheet is conveyed by the movement of the buffer roller, and areas a where no image is formed are not created between each image forming area i. It is possible to prevent wasteful use of media sheets.

Note that the r image writing means j in this invention corresponds to the semiconductor laser device 32, and the image reading means j corresponds to the light source 12a,
It corresponds to the image reading section 12 including lenses 12b and 12c.

(g) Effects of the Invention As described above, according to the present invention, each of the three primary color images is written in three optical image memories, and the image information is guided as reflected light to the same image forming area on the photoreceptor. It will be destroyed. Therefore, three primary color images are superimposed and formed on one image forming area on the photoreceptor, making it possible to form a full-color image on the photoreceptor.

Further, since the optical image memory is exposed entirely to light, unlike the scanning method, the overall exposure time is short (thereby, there is an advantage that the total image forming time can be shortened).

[Brief explanation of the drawing]

Fig. 1 is a schematic front view of an image forming apparatus according to an embodiment of the present invention, Fig. 2 is an enlarged view of the vicinity of the exposure table, Fig. 3 is a block diagram of the image forming apparatus, and Fig. 4 shows the optical system. The perspective view shown, FIGS. 5 and 6 are diagrams showing the characteristics and configuration of the optical image memory, and FIGS. FIGS. 8(A) to 8(F) are diagrams showing other examples of the image information writing and reading steps. Figure 9 (
A) to (G) are diagrams showing the conveyance procedure of the media sheet during image formation, and FIG. 10 is a time chart during image formation. Indicates multi-printing. Furthermore, Fig. 11 (A
) to (E) are flowchart 1 showing the processing procedure during image formation; 11--image writing unit; 12- both image reading unit; 11-16- image forming area.

Claims (1)

[Claims] (1) Three optical image memories in which images are written and read by light; image writing means for writing each of the three primary color images into these three optical image memories; and each of the three optical image memories A full-color image forming apparatus comprising: image reading means for exposing the entire surface to light and guiding the reflected light or transmitted light to the same image forming area of a photoreceptor.