JPS62176270A - Digital color copying machine - Google Patents

Abstract

PURPOSE:To execute simultaneously the exposure of respective colors, to miniaturize a mechanism and to compact the whole body of a copying machine by matching physically a color recording image in respective color information recording devices and executing the overlapping transfer. CONSTITUTION:Respective emitted laser beams are reflected by one rotating polygon mirror 13, and reflected through f-theta lenses 141 and 142 by the first mirrors 15bk, 15y, 15m and 15c. Respective laser beams reflected by the first mirror are guided to respective clearances of respective color information recording devices provided in parallel, reflected by the second mirrors 16bk, 16y, 16m and 16c and irradiated to photosensitive body belts 18bk, 18y, 18m and 18c of respective color information recording devices. Here, the distance between the position to irradiate a laser beam to the photosensitive body belt of the second mirrors 16bk, 16y, 16m and 16c and the position to transfer to recording media is equal to the distance to add the distance from an upstream transfer point to the transfer point of the said device to the said distance in the upstream recording device, and the overlapping transfer of an image can be executed.

Description

[Detailed Description of the Invention] ■Technical Field The present invention relates to a color copying machine, and in particular, an original image is separated into three colors of red, green, and blue using a scanner to obtain gradation data for each color component. The tone data is converted into recording tone data for each recording color yellow, magenta, cyan, and black, and the recording tone data is converted into pixel matrix (area) recording information (pattern information), and based on this pattern information. The present invention relates to a laser writing exposure system of a recording device in a digital color copying machine that reproduces a color image on a sheet by energizing each color recording device to record.

■Prior technology This type of digital color copying machine reads the original image by color separation, for example, red, green, and blue, and then corrects the shading of the read information.

Yellow due to gamma correction etc. and complementary image generation.

Image information for each recording color component such as cyan, magenta, etc. is obtained, and color-specific recording information is created by performing masking processing, undercolor removal processing, nine-gradation processing, and the like. The obtained color-specific recording information is given to each color recording device in recording color categories and superimposed on the same recording paper to form each image.

When one photoreceptor is sequentially exposed to light for each recording color to form an electrostatic latent image, which is then developed for each recording color and transferred to the same recording paper, two or more color recorded images can be generated by one reading of the original image. When obtaining information, the read information or recorded image information must be stored in memory.

However, the amount of image information for each color component of one sheet of document is enormous, and the memory capacity for storing the image information for all color components becomes even more enormous.

Therefore, for example, in Japanese Patent Application Laid-Open No. 58-38966, read information is processed in real time to obtain recorded information, and exposure and development of each recording color is performed simultaneously in real time, and the timing of transfer from the photoreceptor to the recording paper is adjusted. It has been proposed to perform this separately in synchronization with the movement of the recording paper.

However, in this case, the circumferential length of the photoreceptor must be longer than the length of the recording paper, which increases the diameter of the photoreceptor drum and increases the size of the copying machine. In addition, as the photoreceptor drum becomes larger, the arrangement pitch of the photoreceptor drum becomes larger, and the length of the recording paper transport path becomes longer. Since the next copy, that is, exposure cannot be started until the toner image on all the photosensitive drums 11 has been transferred to the recording paper, the copying speed becomes slow.

Also, for example, in Japanese Patent Application Laid-Open No. 54-134439,
By using a photoreceptor belt, the diameter of the photoreceptor drum increases, and a solution to the problem of increasing the size of the copying machine is presented.
The mechanism of the transfer unit to the recording paper becomes complicated, and as a result, the copying machine becomes large and costly.

(1) Purpose The present invention aims to improve the mechanism of the exposure section of a copying machine, downsize it, and eliminate the need for a buffer memory and a frame memory for image information of each color.

■Configuration In order to achieve the above object, the present invention.

Focusing on the fact that recording is performed sequentially for each color component, we developed three or four sets of color information recording devices, each of which records a different color on a recording medium based on recording information for each color component.
A laser beam generator that generates three or four laser beams simultaneously from a predetermined position, a scanning device that deflects and scans the laser beam, and an imaging device that forms an image of the laser beam. and three or four first lenses for guiding the scanned laser beam to each gap of each color information recording device arranged in parallel.
mirror, and three or four second mirrors for guiding the laser beam guided into each gap of the color information recording device to the photoreceptor of the component of each color information recording device, The distance between the transfer point on the recording medium in the recording device and the laser beam t1 irradiation point on the photoconductor of the recording device of the color information recording device is determined by The configuration is such that the distance is equal to the sum of the distance from a transfer point of a color information recording device located upstream in the recording paper transport direction to the transfer point.

According to this, the color recorded images in each color information recording device can be transferred while being physically aligned, and the beam scanning system and exposure system for exposure of the recording device can be simplified, and each recording Exposures in the apparatus can be performed simultaneously. Further, the image information regarding the color to be printed is activated to be recorded in the printing device without being stored in the memory.

Therefore, in this digital color copying machine, the image memory can be omitted. Even when a photoreceptor belt is used as a photoreceptor for each color recording device, it is not necessary to form a toner image of the entire original image on the photoreceptor belt, and the positional relationship of the exposed portions of the photoreceptor belt is determined based on the arrangement of each recording device. As long as it can be specified, the precision of the optical system can be improved and the overall size of the copying machine can be easily reduced as much as possible.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

FIG. 1 shows an outline of the structure of the mechanical section of an embodiment of the present invention, and FIG. 2 shows an outline of the structure of the electrical equipment section.

First, referring to FIG. 1, an original 1 is placed on a platen (contact glass) 2, and a fluorescent lamp 3t for illuminating the original is placed on the platen (contact glass) 2.
t 32, the reflected light of which is illuminated by the movable first
Mirror 41. It is reflected by the second mirror 42 and the third mirror 43, passes through the imaging lens 5, and enters the dichroic prism 6, where it is split into three wavelengths of light: red (R), green (G), and blue CB). The 6-split light is captured by solid-state imaging devices C0D7r, 7g and 7b.
are incident on each. In other words, red light is C0D7r
, green light has a COD of 7g, and blue light has a COD of 7g.
7b.

Fluorescent lights 31 + 32 and the first mirror 41 are the first carriage 8
The second mirror 42 and the third mirror 43 are mounted on the second carriage 9, and the second carriage 9 moves at half the speed of the first carriage 8, so that the original l
The optical path length from to COD is kept constant, and the first and second carriages are scanned from right to left when reading the original image. The first carriage 8 is connected to a carriage drive wire 12 that is wound around a carriage drive pulley 11 fixed to the shaft of a carriage drive motor IO, and the wire 12 is wound around a movable pulley (not shown) on a second carriage 9. As a result, due to the forward and reverse rotation of the motor lO,
The first carriage 8 and the second carriage move forward (original image reading and scanning) and backward (return), and the second carriage 9 moves at 1/2 the speed of the first carriage 8.

When the first carriage 8 is at the home position shown in FIG. 1, the first carriage 8 is detected by a home position sensor 39 which is a reflective photosensor. This detection mode is shown in FIG. When the first carriage 8 is driven to the right during exposure scanning and moves away from the home position, the sensor 39 does not receive light (carriage non-detection). When the first carriage 8 returns to the home position, the sensor 39 receives light ( (carriage detection), and the carriage 8 is stopped when the state changes from non-light reception to light reception. In addition, 4
0 is a carriage guide bar.

Referring now to FIG. 2, CCDs 7r and 7g.

The output of 7b is analog/digital converted and subjected to necessary processing in the image processing unit 100 to produce recorded color information of black (BK), yellow (Y), and magenta (
The signals are converted into binary signals for recording activation of each of M) and cyan (C).

Each of the binary signals is sent to a laser driver 112bk.

112y, 112m and 112c, and each laser driver outputs semiconductor lasers 43bk, 43y, 4
By energizing 3m and 43c, the recording color signal (
A laser beam modulated by a binary signal) is emitted.

Please refer to FIGS. 1 and 4. Each emitted laser beam is reflected by one rotating polygon mirror 13.

f-0 lens 14. and 142, the fourth mirror (
The light is reflected by the first mirror (first mirror) 15bk, 15y, 15+i and 15c, guided to each gap of each color information recording device arranged in parallel, and is reflected by the fifth mirror (second mirror).
16bk, 16y, 16m and 16c and reflected by the photoreceptor belt 18bk of each color information recording device.

18y+ 18111 and 18c are imaged and irradiated.

The rotating polygon mirror 13 is fixed to the rotating shaft of a polygon i drive motor 41, and the motor rotates at a constant speed to rotate the polygon mirror at a constant speed. Due to the rotation of the polygon mirror, the aforementioned laser light is transmitted to the drive rollers 53bk, 53y of the 16-piece belt in a direction perpendicular to the moving direction (vertical direction) of the photoreceptor belt, that is, in the width direction.

Scanning is performed in the direction along the axes 53m and 53c.

Details of the laser scanning system are shown in FIG. 43bk.

'3y+43m and 43c are semiconductor lasers.

The laser beam reflected by the rotating polygon mirror 13 passes through f-0 lenses 141 and 142, and is reflected by fourth mirrors (first mirrors) ljbk, 15y, 15m and 15c, which are arranged in parallel. A fifth mirror (second mirror) is guided to each gap of each color information recording device.
16bk, 16y+ It is reflected by 16m and 16c, and images are irradiated onto the respective photoreceptor belts 18bk, 18y, 18m and 18c.

A sensor 44 made of a photoelectric conversion element is arranged to receive the laser beam at one end of the laser scanning direction along the width direction of the photoreceptor belt, and this sensor 44 detects each laser beam and separates it from the detection. 1 at the time it changes to detection
Detecting the starting point of line scanning. That is, sensor 44
The laser light detection signal (pulse) is processed as a line synchronization pulse for laser scanning.

Referring to FIG. 1, each photoreceptor belt 18bk.

18yy 18m and 18c have 4 motors 50b
k.

Gears 5 lbk, 51y, 51 fixed to the same motor shaft by rotation of 50y+50m and 50c
m and 51c, and the drive roller 53bk of the photoreceptor belt.
.

Gear 52 fixed to 53y*53m and 53c
bk, 52y, 52m and 52c in a clockwise direction. Note that rollers 54bk, 54y, 54m and 54c located above the photoreceptor belt
, which applies tension to the photoreceptor belt, is pressed upward by a spring (not shown). The surface of the photoreceptor belt is a charge scorotron 19bk connected to a positive high voltage generator (not shown).

It is uniformly charged by 19Y, 19m and 19c. When a laser beam modulated by a recording signal is irradiated onto the uniformly charged surface of the photoreceptor, the charge on the surface of the photoreceptor flows from the photoreceptor belt to the equipment ground of the main body and disappears due to a photoconductive phenomenon. Here, the laser is not turned on in areas where the original density is high, and the laser is turned on in areas where the original density is low.

As a result, photoreceptor belts 18bh, 18y, 1
On the surface of 8n+ and 18c, the part corresponding to the high density part of the original has a potential of +800V, and the part corresponding to the low density part of the original has a potential of about +100V. It is formed. Each of these electrostatic latent images is transferred to a black developing unit 20bk.

Developed by E-ro developing unit 2oy, magenta developing unit 20m and cyan developing unit 20c, black and yellow are respectively formed on the surfaces of photoreceptor belts 18bk, 18y+ 18m and 18c.

Forms magenta and cyan toner images.

The toner in the developing unit is negatively charged by stirring, and the developing unit is biased to about +200V by a developing bias generator (not shown), and the toner adheres to the area where the surface potential of the photoreceptor is higher than the developing bias, and is applied to the original. A toner image is formed.

On the other hand, a recording paper 2671 or 2672 stored in a transfer paper cassette 221 or 222 is fed by a feed operation of a feed roller 231 or 232, and is sent to a transfer belt 25 by a registration roller 24 at a predetermined timing.

Reflection type optical sensors 701 and 702 are provided above the recording paper, and the output of the optical sensors is different between ordinary paper (which has a lot of diffuse reflection) and art paper (which has a lot of specular reflection). . Using the sensor output, plain paper is automatically sent out for black mode copying and art paper is sent out for color mode copying. Of course, this control is performed by the control action of a microprocessor system, which will be described later. Furthermore, when color mode copying is specified using the color mode/black mode designation switch 302 (described later), if the reflective optical sensors 701 and 702 do not detect art paper, a warning mark on the console panel 300 lights up. It has become. Transfer belt 25
As the transfer bells 1 to 25 move, the recording paper placed on the recording paper sequentially passes under the photoreceptor belts 18 bk + 18 y - 18m and 18c, and is transferred to each photoreceptor belt 18.
bk, 18y, 18m and 18c, black, yellow, magenta and cyan toner images are sequentially transferred onto the recording paper by the action of a transfer corotron at the lower part of the transfer belt. The transferred recording paper is then sent to a thermal fixing unit 36, where the toner is fixed to the recording paper, and the recording paper is discharged to a tray 37.

On the other hand, the residual potential on the photoconductor surface after transfer is EL eraser 60
The residual toner is removed by the cleaner units 2 lbk, 21y.

It is removed at 21m and 21c.

A cleaner unit 21bk and a black developing unit 20bk that collect black toner are connected to a toner collection pipe 42.
The black toner collected by the cleaner unit 21bk is collected by the developing unit 20bk. Note that the cleaner unit 21y is caused by reverse transfer of black toner from the recording paper during transfer to the photoreceptor belt 18y.

The yellow, magenta, and cyan toners collected at 21m and 21c are not collected for reuse because they are mixed with toner from different color developing devices in the preceding stages of these units.

FIG. 5 shows the inside of the toner recovery pipe 42.

Inside the toner recovery pipe 42, a toner recovery auger 4 is installed.
Contains 3. The auger 43 is formed of a coil spring and is freely rotatable inside the toner collection pipe 42 bent into a channel shape.

The auger 43 is rotationally driven in one direction by a driving means (not shown), and the toner collected in the unit 21bk is transferred to the developing unit 20b by the spiral pump action of the auger 43.
sent to k.

FIG. 9 shows the main parts of the mechanism of one embodiment of the present invention, centering on the transfer belt part.

Referring to the figure, the recording paper is removed from the photoreceptor belt 18bk.
The transfer belt 25 sent in the direction 8c is moved by the idle roller 2
6. Drive roller 27. It is stretched between an idle roller 28 and an idle roller 30, and is rotated counterclockwise by a drive roller 27.

In the drive roller 27, a plunger 35 of a black mode setting solenoid (not shown) is pivotally connected to the right end of a six lever 31 which is pivotally connected to the left end of a lever 31 which is pivotally connected to a shaft 32. A compression coil spring 34 is disposed between the plunger 35 and the shaft 32, and this spring 34 applies a clockwise rotational force to the lever 31.

When the black mode setting solenoid is de-energized (color mode), as shown in FIG. 1, the transfer belt 25 on which the recording paper is placed is the photoreceptor belt 18bk, 18y.

It is in contact with 18m and 18c. In this state, when recording paper is placed on the transfer belt 25 and toner images are formed on all the photoreceptor belts, each toner image is transferred onto the recording paper as the recording paper moves (color mode). When the black mode setting solenoid is energized (black mode), the lever 31 rotates counterclockwise against the repulsive force of the compression coil spring 34, the drive roller is lowered by 5 mm, and the transfer belt 25 is moved from the photoreceptor belt. ' 8yy It is separated from 18+* and 18c and remains in contact with the photoreceptor belt 18bk. In this state, the recording paper on the transfer belt 25 only contacts the photoreceptor belt 18bk, so only the black toner image is transferred to the recording paper (black mode).

Since the recording paper does not contact the photoreceptor belts 1ay, 18m and 18c, the photoreceptor belts 18y+1 are placed on the recording paper.
8m and 18c adhered toner (residual toner) does not stick, and yellow, magenta, cyan, etc. stains are completely removed. In other words, when copying in black mode, copies similar to those produced by a normal monochromatic black copying machine can be obtained.

The console board 300 includes a copy start switch 301. Color mode/black mode designation switch 302 (
Immediately after the power is turned on, the switch key is off and the color mode is set; when the switch is closed for the first time, the switch key lights up and the black mode is set, and the black mode setting solenoid is energized;
When the switch is closed for the second time, the switch key turns off, the color mode is set, and the black mode setting solenoid is de-energized), the automatic density setting switch 303 (the automatic density setting mode is canceled immediately after the power is turned on, and the black mode setting solenoid is de-energized). The automatic density setting mode is set by the first switch suppression, and the automatic density setting mode is canceled by the second suppression), as well as other input key switches, a character display, an indicator light, etc.

Next, the operation timing of the main parts of the copying mechanism will be explained with reference to the time chart shown in FIG. FIG. 6 shows the case where two identical full-color copies are made in the non-automatic density setting mode. Almost at the same timing as the start of exposure scanning of the first carriage 8, the lasers 43bk, 43y,
43m and 43c.

Modulation energization is simultaneously started based on the recording signal.

This modulation energization is performed simultaneously, and exposure is performed at an irradiation point that is physically separated by the moving distance of the transfer belt 25 from the transfer point where each recording device is located (FIG. 1).

Transfer corotrons 29bk, 29y, 29m and 29c are lasers 43bk, 43y and 43, respectively.
It is energized after a delay of a predetermined time (time for the laser irradiation position on the photoreceptor belt to reach the transfer corotron) from the start of the modulated energization of +i and 43c. Note that when the automatic density setting mode is set by suppressing the automatic density setting switch 303, a prescan is executed as shown by the broken line in FIG.

See Figure 2. The image processing unit 100 is a CCD
The three color image signals read by 7r, 7g and 7b are
The signal is converted into black (BK), yellow (Y), magenta (M), and cyan (C) recording signals necessary for recording. Note that the image processing unit 100 is supplied with three color signals from the CCDs 7r, 7g, and 7b in the copying machine mode as described above.

In the graphics mode, three color signals are applied from outside the copying machine through the external interface 117.

Shading correction circuit 10 of image processing unit 100
1 is the color gradation data obtained by A/D converting the output signals of the CCDs 7r, 7g and 7b into 8 bits, and is corrected for optical illumination unevenness, sensitivity variations in the internal unit elements of the CCDs 7r, 7g and 7b, etc. to create read color gradation data.

The multiplexer 102 is a multiplexer that selectively outputs either the output gradation data of the correction circuit 101 or the output gradation data of the interface circuit 117.

The γ correction circuit 103 that receives the output (color gradation data) of the multiplexer 102 changes the gradation (input gradation data) according to the characteristics of the photoreceptor, and also changes the density arbitrarily or automatically using the operation button of the console 300. In the setting mode, the gradation is automatically changed and input 8-bit data is changed to output 6-bit data. Since the output is 6 bits, data representing one of 64 gradations will be output.

In the automatic density setting mode, the peak hold circuit 120 captures the value of the highest density part of the document during pre-scanning, that is, the smallest value of red (R), green (G), and blue (B). Based on that data, the synchronization control circuit 114 determines the operating characteristics of the γ correction circuit 103! Change settings according to lJ.

Next, perform the main scan for printing operation.1. Performs a series of signal processing including γ correction of the set γ correction characteristics,
Get proper print quality. This relationship is shown in FIG.

FIG. 16 is an input/output characteristic diagram of the γ correction circuit showing the relationship between automatic density settings in the automatic density setting mode. The relationship between the γ correction circuit input of value data converted to original density and the γ correction circuit output of value data converted to print density is shown below when the output of the prescan peak hold circuit is equivalent to 0.7. As the characteristic line 401 of the γ characteristic setting,
A characteristic line 402 for setting the γ characteristic when the output of the prescan peak hold circuit is equivalent to 1.0, and a characteristic line 402 for setting the γ characteristic when the output of the prescan peak hold circuit is equivalent to 1.7. 403.

Red (R) output from the γ correction circuit 103.

Three-color gradation data of 6 bits each indicating the gradation of green (G) and blue (B) is applied to a complementary color generation and black separation circuit 104.

The configuration of the complementary color generation and black separation circuit 104 is shown in FIG. Complementary color generation involves converting color reading signals into respective recording color signals, as shown in FIG.

Red (R) gradation data is cyan (C) gradation data,
Green (G) gradation data is converted to magenta (M) gradation data, and blue gradation data (B) is converted to yellow gradation data (Y). This C, M, and Y gradation data is applied as is to the averaging data compression circuit 105. If all of these gradation data indicate high density, it is sufficient to record black, so the digital comparators 104c and 1
At 04m and 104y, the C, M, and Y gradation data are each compared with the reference value data set by the threshold value setting switch 104sh. digital comparator 104c,
104m and 104y are for comparing 8-bit data, and the data (input data) obtained by adding the 6 bits of 1 gradation data and the upper 2 bits of the L level are added to the 1 bit of the lowest digit and the upper digit. It is compared with 8-bit data (reference value data) in which the digit 3 bits are at L level and the 2nd to 4th bits from the lowest are reference value data set by the threshold value setting switch 104sh, and the input data is less than or equal to the reference value data. If so, L is given to the Nantes gate 104a, and if it is exceeded, H is given to the Nantes gate 104a. The Nant gate outputs L (black) when all the comparators are giving an L signal, and outputs H (white) when any one is giving an I signal, and provides the output to the data selector 110. To explain this in more detail, the gradation data input to the comparator is 6-bit data I in hexadecimal 0 to 3F.
The range of Il is black when it is 0, and white as the value increases.

When writing black output, the configuration is such that L represents black and I] represents white. Therefore, the 2 MSB bits (Q6, 7) of the 8-bit input data are input to L, and the gradation data of C, M, and Y are input to the lower 6 bits (QO to 5), respectively. On the comparison data side, a rotary set of switches 104sh is used so that the comparison level can be set in seven stages. Furthermore, since it is a black level setting, if too much white color is included in black, halftone (gray) can be recorded as black and resolution can be increased, but on the other hand, color balance 1 black will occur more often, which is undesirable. You can now set up to 7 levels.
, 6th bit. Also, since there is no need to make very detailed settings, I set LS[1 (II) 1 bit to L and input the setting value from switch 104sh to the middle 3 bits (PI to 3). If the setting of 104sh is 010, the reference value will be 0000010, and C, M,
When all the data of each Y is less than this value, that is, 10
Between base 0 and 3, the output of the comparator is L and black (BK
) output is L (black). Here, setting switch 10
4sh is commonly used for comparison judgment of C, M, and Y, but by using three sets, it is possible to set each color separately, and to set the setting range width of each color to the minimum.

By setting using the highest setting switch, it is also possible to output a specific color in a black pattern with good resolution.

Averaging data compression circuit 105 of image processing unit 100
is 4 bits of gradation data for one image.
×4 image data are averaged and output as 6-bit gradation data. In this example, it is assumed that the size of the input image and the output image are the same, and the input data (C
The data read from the OD) is converted into 8-bit data by A/D conversion, and converted to 6-bit data by gamma correction, but the output data to the laser driver depends on whether the laser is on or off (1
bit) data. 64 depending on input 6-bit data
Ftff-like density separation is possible, and the dither method and density pattern method are well known for output density reproduction. Generally, an 8×8 matrix is used to express 64 gradations using the density pattern method. Therefore, 8 of the input data
The density of ×8 pixels is averaged and the output 8×8 matrix (W
(density pattern conversion in the I tone processing circuit 109). Furthermore, this averaging compresses the data amount and processing speed to 1/64, reducing the data capacity for storage and the cost of the hardware unit.

It is possible to make the size of the input reading pixel 8×8 times that of the output, but this is not adopted in this device because, as mentioned above, we do not want to reduce the resolution of black parts (normal characters).

FIG. 8a shows the configuration of the averaging data compression circuit 105,
FIG. 8b shows the operation timing of the circuit 105. The data to be averaged is 8 pixels in the sub-scanning direction (the exposure scanning direction of the first carriage 8) x 8 pixels in the main scanning direction (direction perpendicular to the exposure scanning direction: CCD electronic circuit scanning direction), for a total of 64 pixels. be.

Also, when averaging 64 pieces of 6-bit data, if you add all the data and then reduce it to 1/64, the adder will be 12
Although a bit adder is required, in this embodiment, processing is performed using an 8-bit adder. First, sub-scanning direction 8
To explain pixel addition, the first data is latched in latch 1 and added to the second data in adder 1, and the added value data is latched in latch 2. The third data is latched in latch 1, added to the fourth data in adder 1, further added to the data in latch 2 in adder 2, and the sum of the 4 pixel data (gradation data) is added to the adder 1. Output from 2. This data is latched into latch 3.

Similarly, when the fifth to eighth data are added and output from the adder 2, they are added to the data in the latch 3 by the adder 3, and data for every eight pixels in the sub-scanning direction is output.

Note that the output of adder 1 becomes 7 by adding 6-bit data.
The output of adders 2 and 3 is the addition of 7-bit data, and the processing result of adders 2 and 3 is 8 bits, but the output takes the upper 7 bits and essentially divides the added data by 1/2.
The value is set to 2.

Next, addition in the main scanning direction will be explained. The average value of the 8 pixels output from the adder 3 corresponds to one main scanning line, and the RA of the memory
It is stored in M1. , when the second line is output from adder 3, it is added to the contents of RAM 1 by adder 4 and the RA
It is stored in M2. By this addition, the first line data +
Second line data is stored in RAM2. When the third line is output from the adder 3, the adder 4
It is added to the contents of I and stored in RAM2. This addition causes 1+2 line data to be stored in RAM2.

When the 3-line row is output from the adder 3, the adder 4 adds it to the contents of the RAM2 and stores it in the RAM1. Similarly, RAMI, 2 alternately serves as addition data output (reading) and storage, and when the 8th line is output from the adder 3, it is added to the contents of RAMI by the adder 4, and 8 lines of addition data are output. Here, adder 4 also has adders 2 and 3
Similarly, by outputting the upper 7 bits of the 7-bit data addition, averaged (1/2) L data is output. In this embodiment, two 4-bit binary full adders (74283) are used in parallel as adders. This circuit can be adapted to various matrix sizes by changing the number of latches and adders on the sub-scanning side.

Next, ÷ skinning processing circuit 106 and UCR processing circuit 1
07 will be explained. The calculation formula for masking processing is generally as follows: Yi, Mi, Ci: data before masking.

'yo, MO, Co: Data after masking.

In addition, the general formula for UCR processing is It can be expressed as

Therefore, in this example, using these equations, we use the product of both coefficients.

is calculated to find new coefficients. The coefficients (allI, etc.) of the above calculation formula that perform both the masking process and the tJCR process at the same time are calculated in advance and substituted into the above calculation formula, so that the planned input Yi of the masking processing circuit 106,
The calculated value (Y
o', etc.: output of the UCR processing circuit 107) are stored in the ROM in advance.

Therefore, in this embodiment, the masking processing circuit 10
6 and the UCR processing circuit 107 are composed of a set of ROMs, and the data at the address specified by inputs Y, M, and C to the masking processing circuit 106 is input to the UCR processing circuit 10.
7 is applied to the gradation processing circuit 109. Generally speaking, the masking processing circuit 106 performs Y, M,
The UCR processing circuit 107 is for correcting the C signal, and the UCR processing circuit 107 is for correcting color balance in overlapping toners of each color.

Next, the gradation processing circuit 109 that performs density pattern processing of the image processing unit 100 will be described. This circuit 109 is
, M, and C to generate a pattern corresponding to the density thereof, and is constituted by a ROM.

The 6-bit gradation data can represent density information of 64 gradations. Ideally, if the dot diameter of one dot could be varied in 64 steps, there would be no need to reduce the resolution, but in the laser beam electrophotography method, the dot diameter modulation is only stable at about 4 steps at most, and in general, the density pattern method is There are many combinations of density pattern method and beam modulation. Here, a processing method of expressing 64 gradations using an 8×8 matrix is used. circuit 10
9 has 64 types of 8×8 density patterns per group, and uses a method of outputting 8-bit data in the sub-scanning direction based on gradation data and a main-scanning address.

Now, if the density pattern is 64 patterns (this is called 1 group) created based on the binarized data in which the threshold level is distributed in a spiral shape as shown in Figure 10a, this pattern will be the same when the density is 0. The number of dots to which toner is applied within the 8x8 matrix is 0, and toner is applied to the number of dots represented by the density data.When the density is 32, toner is applied to the shaded area shown in Figure 10a. . Therefore, data in a certain column is sequentially processed by the processing circuit 109.
, 8-bit data is output in data order from main scanning address 1, and by parallel-to-serial conversion and output, data for one line in the sub-scanning direction is obtained. After outputting the data eight times in the main scanning direction (processing eight lines), the next data string is input. For example, the main scan 3 data of data string 20.32.40 is 0011111
0,01111110,11111111. Here we have shown 64 gradation expression using an 8x8 matrix, but as a way to increase the resolution, it is possible to combine it with dot diameter modulation.
Submatrix methods and the like have been proposed. Similar gradation expression can also be achieved by changing the pattern or by outputting from the pattern. Regarding color processing, the Y, M, C, and BK density patterns may not be the same pattern, but the pattern generation angle may be changed for each color in order to prevent moiré. That is, a plurality of pattern groups are created and patterns of different groups are assigned to each color.

The recording signals assigned to BK include the dot pattern (binary signal) from the black separation circuit 104 and the OCR processing circuit 10.
It is necessary to synthesize the density pattern (gradation pattern signal) generated from the BK gradation information from 7. Simply put, for black in text areas, applying toner based on the binary signal from the black S circuit 104 has higher resolution than applying toner based on density pattern information. On the other hand, toner application based on density pattern information has higher image reproducibility.

The following method can be considered to synthesize the dot pattern (binary signal) from the black separation circuit 104 and the density pattern (gradation pattern signal) generated from the BK gradation information from the UCR processing circuit 107. In other words, (a) simply OR the two (if at least one is black, toner is applied/recorded); (b) the black to be recorded in the 8x8 matrix is output by the black separation circuit 104; Then, the output of the black separation circuit 104 is assigned to that matrix, and if there is no output, the data of the density pattern is assigned, and (c) the black to be recorded in the 8×8 matrix is output by the black separation circuit 104. Then, the output of the black separation circuit 104 is assigned to that matrix, and the number of "black" output by the black separation circuit 104 is compared with the number of "black" of the density pattern to be assigned to the matrix, and the amount by which the latter exceeds the former is calculated. is randomly assigned to the white part of the 71st helix.

The 8x8 matrix area is filled with black (
10d), the output of the black separation circuit 104 becomes the distribution shown in FIG. 10c, and the density pattern specified based on the BK high output of the UCR processing circuit 107 is
When the heat distribution is as shown in the figure, according to the method (a) above, the recording signal shown in FIG. 11a is obtained, and the recording signal shown in
According to the method (c), the recording signal shown in FIG. 11b is obtained, and the recording signal shown in FIG. 11c is obtained according to the method (c).

Method (a) above is simple in terms of hardware, but
As shown in figure a, there are cases where the number of recorded points increases.

In contrast to improving the resolution of black characters, which is one of the purposes of this embodiment, this results in a relatively unfavorable result in that the edges of the black image become black and blurred. In the above method (b), data processing is divided into 8×8 matrix sections, and it is determined whether or not there is an output "black" from the black separation circuit 104 in one section, and if there is, the output of the circuit 104 is This can be done by assigning. In other words, it can be realized with relatively simple hardware and logic. Moreover, this method can achieve the purpose of improving the resolution of characters. However, if the image is a halftone image, the density of black will be lower by 5 dots than when the density pattern is assigned.

The above method (c) solves the problems of (a) and (b). However, in reality, although the difference is easily determined, the hardware and logic for randomly assigning the difference to the white area become complex.

As a result of the above considerations, this embodiment adopts the method (b) described above from the viewpoint of improving the resolution of black characters. This method is performed by data selector 110 shown in FIG.

FIG. 12 shows the configuration of the data selector 110.

O (L: white) for each pixel from the black separation circuit 104.

1 (H: black) data is serial/parallel converter 11
By 0a, every 8 bits are output in parallel and OR gate O
If there is even one black (1) in the 8 bits of RI, "1" is output, and if all of them are black (0), "0" is output. This output is stored in the 1 line 2 minute RAMI, and when the second line is input, it is ORed with the data of the first line stored in RAM1 and stored in RAM2. In this way, the data for 8 lines are sequentially ORed.

During this time, the parallel-converted 0 (L: white)) and 1 (H: black) data for each pixel from the 1-separation circuit 104 is written to the line buffer 110b with a capacity for 8 lines. When this writing is completed, the timing pulse becomes 1, the AND gate ANDI is opened, data is given to the data selector 110c line by line from the line buffer 110b, and density pattern data is sent line by line from the processing circuit 109. is applied to the selector 110c, and also to the RAM
Data No. 2 is repeatedly read out and applied to the control data input terminal of the selector 110c.

When there is an output point of the black separation circuit 104 in the 8×8 matrix section, the output of the RAM 2 is 1, so the data selector 110c sends the output of the buffer 110b to the laser driver 112b through the OR gate 111 (FIG. 2).
give to k. When no output from the separation circuit is black, density pattern data is given.

The peak detection circuit 115 of the image processing unit 100 is meaningful in the monochromatic black copy mode and the automatic density setting color/monochrome mode, and converts each of the R, G, and B signals into analog signals, and compares the three analog signals. The highest value among these three is output to the binarization circuit 116.

The binarization circuit 116 converts the input signal into black (1: recording).

It is binarized into a signal indicating white (0: non-recording). The binary signal is passed through an OR gate 111 to a laser driver 112.
given to bk.

The peak hold circuit 120 is used for automatic density setting mode in color or monochrome mode. (2) The maximum density of the image signals R, G, and B of a frame is detected and held.The input is the output from the peak detection circuit 115, and the output of this peak hold circuit 120 is passed to the synchronization control circuit 114.

The synchronization control circuit 114 determines the activation timing of each of the above elements and matches the timing between each element. Reference numeral 200 denotes a micro processor system 1 that controls all the elements shown in FIG. 2 described above, that is, controls the copying machine.
It is 1. This processor system 200 controls copying in various modes set on the console, and includes not only the image reading/recording system shown in FIG. 2 but also the photoreceptor power system and the exposure system.

Performs sequence control of charger system, developing system, fixing system, etc.

The copying machine of this embodiment is capable of not only full-color copying but also single-color black copying, and the console 300 is equipped with a switching instruction key switch 302 for switching settings between full-color mode and single-color black mode. This switch 30
Mo according to the operation of 2.

The code settings have already been explained. Here, the operation when the monochromatic black mode is set will be explained.

The image scanning section such as the first carriage operates in the same way as in the full color mode in the monochromatic black mode, and the RlG and 0
Three color signals are output from the γ correction circuit 103. Peak detection circuit 1 that did not work in full color mode
15 and the binarization circuit 116 operate, and conversely, the complementary color generation and black separation circuits 104 to gradation processing circuit 109 that operate in color mode, as well as the laser driver 112ytm.
tc and lasers 43y, ++, c do not operate in monochromatic black mode. The operation or non-operation of these circuits is determined by the control operation of the synchronous control circuit 114 based on instructions from the processor system 200. The output of the γ correction circuit 103 is given to the peak detection circuit 115.
gives the analog voltage of the highest level among the three voltages to the binarization circuit 116. The binarization circuit 116 includes:
There is a threshold level set to a predetermined value, and the input is compared with this level, converted into a 1-bit digital signal, and provided to the OR gate 111. This output is given to the laser driver 112bk through the OR gate 111. Laser driver 112bk energizes laser 43bk based on the applied signal. That is, the laser is modulated and controlled based on the signal.

On the other hand, in the recording system, in the monochrome black mode, the charger corotrons 19y, m, c, developing units 20y, w, c, and transfer corotrons 29y+I''pc stop operating, and the rest operate in the same way as in the full color copy mode. The operation and non-operation of the controllers are controlled by their drivers according to instructions from the processor system 200.

FIG. 13 shows an interface between the polygon mirror drive motor 41 and the microprocessor system (200: FIG. 2). Input/output port 207 shown in FIG. 13 is connected to bus 206 of system 200.

In addition, in Fig. 13, 50bk, 50y, 50a
+ and 50. c is photoreceptor belt 18bk, 18y,
This is a motor that rotationally drives l8+a and l8c, and is energized by motor drivers 49bk, 49y, 49m and 49c.

Also, motors 50bk, 50y, 50m and 50
c is for adjusting the joints of photoreceptor belts 18bk, 18y, 18m and 18C to their respective predetermined positions.

Seam sensor 55bk, 55yt 55m and 55c
(Figs. 1 and 13) are provided. Based on the feedback signals from the seam sensors 55bk, 55y, 55+n and 55c, the motors 50bk, 50
y.

50m and 50c are rotated after the copy operation.

That is, seam sensors 55bk, 55y, 55a+
and 55c detect their respective seams, motor 5
The rotation of 0bk, soy, 5x and 50c stops and goes into hibernation. In addition, photoreceptor belt 18bk, 1
A black mark is attached to the inner seam of 8y*18+s and 18c, which is detected by seam sensor 5 Sbk, 5
5y.

55m and 55c perform these control operations by detecting changes in the amount of incident light. In addition, there are drivers for energizing each component of the copying machine, processing circuits connected to sensors, etc., which are connected to the input/output port 207 or other input/output ports and coupled to the system 200; has been omitted.

The transfer paper feed roller 231 corresponds to the operation timing of the first carriage 8 in both the full color mode and the single color black mode.
and 232. @ Imager 20bk, registration roller 24.
The operation timing of the transfer corotron 29bk and the like is the same.

The fact that the photosensitive drum 18bk for black recording is located at the most upstream position when viewed from the paper feeding side has the advantage that recording device energization control in the monochromatic black mode is simple.

If the black recording device is not located at the most upstream position as in the embodiment, but at the most downstream position as in the conventional case, the recording paper Feed roller 23. The operation timing of the registration roller 24 and the like differs between the full color copy mode and the monochrome black copy mode. In other words, control becomes that much more complicated.

Next, the operation timing of each part based on the control operations of the microprocessor system 200 and the synchronous control circuit 114 will be explained.

First, when a power switch (not shown) is turned on.

The device starts the warm-up operation, ・Raises the temperature of the fixing unit 36, ・Starts the polygon mirror to rotate at a constant speed, ・Positions the carriage 8 in the 11 position.

・Clock generation for line synchronization (1,26KIIz),
・Clock generation for video synchronization (8, 42M1lZ),
・Perform operations such as initializing various counters. The line synchronized Glock is supplied to a polygon mirror motor driver and a CCD driver, and the former uses this signal as a reference signal for a phase-locked loop (PLL) servo, and a feedback signal to a beam sensor 4.
The beam detection signal No. 4 is controlled to have the same frequency as the line synchronization clock and to have a predetermined phase relationship. The latter is used as a main scanning start signal for CCD reading. Note that the signal for synchronizing the start of laser beam main scanning is the detection signal (pulse) of the beam sensor 44.

is commonly output for each color, so use this.

Note that the frequency of the line synchronization signal and the detection signal of each beam sensor are locked by PLL and are the same, but there may be a slight phase difference, so the scanning reference is not the line synchronization signal but the frequency of each beam sensor. The detection signal is used.

The video synchronization clock has a frequency of one dot (one pixel) and is supplied to the CCD driver and laser driver.

Various counters.

(1) read line counter, (2) @write line counter, (3) read dot counter, and (4) write dot counter. (3) and (4) are provided individually on the hardware, although not shown.

Next, the timing of the print cycle is shown in Figure 14,
Let me explain this.

When the warm-up operation 11 is completed, the printer becomes ready to print, and when the copy start key switch 301 is turned on, the drive motor of the first carriage 8 (FIG. 13) starts rotating due to the operation of the CPU 202 of the system 1, 200. Starting carriages 8 and 9 (8 172 speeds)
starts scanning (exposure scanning) to the left. When the carriage 8 is at the home position, the output of the home position sensor 39 is I, and the exposure scan (sub-scan) is shortly after starting. At the time of this transition from H to L, the read line counter is cleared and at the same time the count is enabled. Note that the time point at which H changes to I- is the position where the leading edge of the document is exposed.

With the line synchronization clock that comes in after the sensor 39 goes low, the read line counter is counted up every pulse. Also, when the line synchronization clock comes in, the reading dot counter is cleared at the rising edge and counting is enabled.6 Therefore, the first line reading is performed after the home position sensor 39 becomes Pixel 199, . still,
Pixel counting is done by a read dot counter. Further, the content of the read line counter at this time is 1.

Similarly, for the second and subsequent lines, the reading line counter is incremented by the next line synchronization clock, the reading dot counter is cleared, and synchronized with the next video synchronization clock, the reading counter is incremented and pixels are read. Let's do it.

In this way, the lines are sequentially read, and when the reading line counter counts up to 6615 lines, the last reading is performed on that line, and the carriage drive motor is reversely energized to return the carriages 8 and 9 to their home positions.

The pixel data read in the above manner is sequentially sent to the image processing unit 100 and subjected to various image processing. The time required to perform this image processing is only two clocks of the line synchronization clock signal.

At least it takes.

Next, in writing, first the write line counter is cleared and counting is enabled in the following manner: When the read line counter is 2, the write counter is cleared and counting is enabled.

These count-ups are performed at the rising edge of the detection signal of the beam sensor 44. Further, the write dot counter is cleared at the rising edge of the detection signal of the beam sensor, and counting up is performed by the video synchronization signal.

Writing for each color begins when the content of the reading counter reaches a predetermined value, the writing line counter for each color becomes counting enable, and counting starts with the first beam sensor detection signal (content 1). When the dot counter reaches a predetermined value, the laser driver is driven to perform writing. Dot count is 1-4
00 is dummy data, 401 to 5077 (46
77) are writable values. Here, the dummy data includes the beam sensor 44, the photoreceptor belt 18bk,
This is to adjust the physical distance of 18y, 18m and 18c. Also, write data (1 or O)
is captured at the falling point of the video sync signal. The writing range in the line direction is 1 to 66 for each writing line counter.
This is when there are 15 lines.

Now, as shown in FIG. 14, after starting the exposure scan,
Since recording data is obtained from the time of scanning the third line of OD, each recording device starts recording energization in synchronization with the acquisition of data.

In the automatic density setting mode, before the carriage scanning, carriage scanning (prescanning) is performed to read the maximum density of the document.

Next, other embodiments and modifications of the present invention will be described.

In the above embodiment, in addition to full-color copies, it is possible to create copies with only a single black color, but this can be done in addition to full-color and single-color copies, as well as single-color copies of other colors and copies of a smaller number of colors than the full-color copy. It is also possible to use a copying machine that makes overlapping copies.

An example configuration in this case is shown in FIG. 15. In this case, the transfer belt 25 is replaced by the photoreceptor belt 18bk.

1 Bye Four idle rollers 47bk, 47y, 47 to selectively contact 18m and 18c
m and 47c, and solenoids 48bk, 48y, and 48sn that drive each idle roller to the contact position.
and 48c. In this.

Solenoid 48bk for full color copying.

48yy48m and 48c are all energized and transfer belt 25 contacts all photoreceptor belts. solenoid 48
When only bk is energized, it becomes a monochrome black copy, and 48
When only y is energized, the copy is monochrome yellow, when only 48m is energized, the copy is monochrome magenta, when only 48c is energized, the copy is monochrome cyan, and copies of various other combinations of colors can also be set.

For example, when solenoids 48yy48m and 48c are energized at the same time, a three-color full-color copy is made.

Simultaneous energization of two solenoids results in two-color overlapping copies.

■Effects As described above, according to the present invention, the beam scanning system and FF optical system for exposure of the recording device in a color copying machine can be simplified, and exposure can be performed in each recording device at the same time, and recording can be performed easily. The image information about the color to be displayed is recorded in the recording device without being stored in the memory.
Image memory can be omitted, and the entire copying machine can be configured compactly.

Compared to the configuration of a conventional copying machine, the precision of the optical system for laser beam exposure can be improved, and the size of the entire copying machine can be easily reduced as much as possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view mainly showing the structure of the main parts of the mechanism of an embodiment of the present invention, FIG. 2 is a block diagram showing the structure of the main parts of the electrical system, and FIG. FIG. 4 is an exploded perspective view of the exposure scanning system for each recording device shown in FIG. 1, and FIG. 5 is an enlarged perspective view of a part of the carriage 8. FIG. FIG. FIG. 6 is a time chart showing the relationship between original reading scanning timing, recording biasing timing, and transfer biasing timing in the above embodiment. FIG. 7 is a block diagram showing the configuration of the complementary color generation and black separation circuit 104 shown in FIG. 2, FIG. 8a is a block diagram showing the configuration of the averaging data compression circuit 105 shown in FIG. 5 is a time chart showing a data processing sequence of the circuit 105. FIG. FIG. 9 is a side view schematically showing the transfer belt portion of the main part of the mechanism shown in FIG. 1. FIG. 10a is a plan view showing the distribution of threshold level data used in creating the density pattern stored in the gradation processing circuit 109. FIG. 10b is a plan view showing the image distribution of the 8×8 dot matrix area on the original, FIG.
FIG. 0d is a plan view showing the BK density pattern output of the gradation processing circuit 109 developed in a plane. FIG. 11a shows the BK ratio output circuit 109 of the circuit 104.
FIG. 11b is a plan view showing a planar development of the logical sum of density pattern outputs; FIG. 2 is a plan view showing a recording signal distribution in which the difference between the output of the circuit 104 and the "black" density pattern signal is randomly arranged in a white area. FIG. 12 is a block diagram showing the configuration of data selector 110, and FIG. 13 is a block diagram showing a portion of copying mechanism elements connected to microprocessor system 200. FIG. 14 is a time chart showing the relationship between exposure scanning and recording energization of the copying machine shown in FIG. FIG. 15 is a side view showing an outline of the main parts of the mechanism of another embodiment of the present invention. FIG. 16 is a turnout characteristic diagram of the γ correction circuit showing the relationship between automatic density settings in the automatic density setting mode. 1: Document 2 Nibraten 31.3□: Fluorescent lamp 41-43: Mirror 5: Variable magnification lens unit 6: Dichroic prism 7r, 7g, 7b: CCD 8: First carriage 9: Second carriage 10: Carriage drive motor 11 : Pulley 12: Wire 13: Polygon mirror 141, 142: f-〇 lens 15bk, 15y, 15m, 15c: Mirror (first mirror) 16bk, 16y, 16+n, 1
6c: Mirror (second mirror) 18bk, 18y, 1
8m+, 18c: Photoreceptor belt (photoreceptor) if) bk
, 19y, 19+o, 19c: Charge scorotron 20bk, 20y, 20+s, 20c: Developing device 21bk, 21y, 21m, 21c: Cleaner 22
,．． 222: Transfer paper cassette 231.232: Paper feed roller 24 Ni registration roller 25: Transfer belt 26.28
, 30: Idle roller 27: Drive roller 29bk, 2'ly, 29m, 29c:
Transfer Corotron 31 Nilever 32: Shaft 33: Pin 34: Compression coil spring 35
: Black copy mode setting solenoid plunger 36: Fixing device 37: Tray 39: Home position sensor 40: Carriage guide bar 41: Polygon mirror drive motor 42: Toner collection pipe 43bk, 43y, 43m, 43c: Laser 44: Beam sensor 46: Motor driver 4') bk, 49y, 49m, 49c: Motor driver 50bk, 50y, 50m, 50c:
Photoreceptor belt drive motor 51bk, 51y, 51m, 5
1c: Gya 52bk, 52y, 52+w, 52c:
Gear 53bk, 53y, 53a+, 53c
: Photoreceptor belt drive rollers 54bk, 54y, 54m
+, 54c: roller 55bk, 55y, 55
o+, 55c: Seam sensor 60bk, 60y, 6
0trr, 60c: E L eraser 70, . 702
:Sensor 100:Image processing units 104y, 104n+, 104c:Digital comparator 1
04sh: Rotary switch 2671.2672: Recording paper 200: Microprocessor system 300: Console 301: Copy start key switch 302: Full color/m color black mode selection key switch 3
03: Automatic concentration setting switch Figure 9 City 3 Figure Ming Tower 5 Figure Voice 10a Figure 10a Figure Tsume Koushun p Figure 11a Figure 11b) rK (a) I) a7y
Direction% (b) Q #夷job figure Hayabusa 1Od figure UCRsAJ: Tar / Figure 11a, direction ((C) Su Δζn

Claims (4)

[Claims] (1) An image reading device that separates and reads the original image, an image processing device that processes the read image signal into recorded information for each of 3 or 4 color components, each based on recorded information for each color component. three or four sets of color information recording devices arranged parallel to each other to record different colors on a recording medium; a laser beam generator that simultaneously generates three or four laser beams from a predetermined position; a scanning device that deflects and scans the laser beam; an f-theta lens that focuses the laser beam; and three or four first lenses that guide the scanned laser beam to each gap of the color information recording device. a mirror, and three or four second mirrors for guiding the laser beam guided into each gap of the color information recording device to the photoreceptor of the component of each color information recording device,
The distance between the transfer point on the recording medium in each of the color information recording devices and the laser beam irradiation point on the photoreceptor of the color information recording device is the same as that in the color information recording device located upstream in the recording paper transport direction. A digital color copying machine characterized in that the distance is equal to the sum of the distance from a transfer point of a color information recording device located upstream in the recording paper transport direction to the transfer point. (2) The digital color copying machine according to claim (1), wherein the photoreceptor as a component of the color information recording device is a photoreceptor belt. (3) The digital color copying machine according to claim (2), wherein the photosensitive belts, which are components of the color information recording device, are arranged parallel to each other along the recording paper transport path. (4) Each color information recording device includes a photoconductor, a charger that uniformly charges the surface of the photoconductor, an exposure section that receives laser beam light on the photoconductor according to recorded information, and an electrostatic latent formed by exposure. The recording apparatus is equipped with a developing device for developing an image and a transfer device for transferring the developed image onto recording paper, and the photoreceptors of each recording apparatus are arranged in parallel along the conveyance path of the recording paper. A digital color copying machine according to claim (1).