JPS61123257A - Synchronous control system of color picture processing system - Google Patents

Abstract

PURPOSE:To attain digital color picture processing without requiring an expensive host computer by executing read and print of a color picture to satisfy the high-picture element density and high speed. CONSTITUTION:When a tip (a) of an actuator plate of a transfer drum 16 of a color printer 2 is detected by an ITOP sensor 20, the exposure scanning of a scanning unit 4 ofa color reader 1 is started and when the tip T of an original 3 is detected by a DTO sensor 22-2, the read of an original picture and write to a synchronous memory are started, and when a rear end (b) of the actuator plate 19 is detected by an ITO sensor 20 to start the read of a picture data and write of a picture toa photosensitive drum 15 at the same time. The variance in time when the scanning unit 4 is started from a stop position 22-1 until it reaches the DTOP sensor 22-2 is absorbed by the synchronous memory.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a digital color image processing system such as a copying machine or a facsimile, particularly when a read color image is printed out in real time, or when the system does not have an image memory. The present invention relates to a synchronization control method for overlapping color images between a color image information reading device and a color image information printing device.

[Prior art]

Traditionally, when obtaining a hard copy of a color image.

For example, in color printers such as thermal transfer and electrophotographic methods, full color ( (Full color) You are getting a hard copy of the image. And in this case, 7 images 9
The M and C images must be superimposed on the recording medium (recording paper) with high precision. For example, even if the deviation between each image is about 0.1 mm, the color image will be blurred and the sharpness will be lost. There was a problem that the color lacked strength and the color became muddy, resulting in a decrease in saturation.

For this reason, conventionally, an image memory for at least one page is provided, and the image memory is synchronized with a reference signal that is the leading edge of one image.
Read the image information from the image memory and send it to Y
, M, and C to make one color match. Normally, such color printers are connected to a host computer that controls the entire system, and the above-mentioned image The memory is the host computer's large capacity memory (for example, MT (Ray Tape), etc.
It has a storage capacity of color data for three Y, M, and C disks.

On the other hand, a digital color image copying system equipped with a digital image reading system is equipped with an image memory for at least one page, and reads color separation image information in the order of Y, M, and C for the above-mentioned synchronization. , After storing the read information in its image memory, it is synchronized with the reference synchronization signal,
A method of sequentially printing out image information is also being considered. However, in a digital color image copying system with high pixel density, image information is read at 1 apel/m, for example, and A4 size (297 x 210
mm), the amount of image information is approximately 18 megabits (Mbit) per image, and this is Y.

If it has three disks, M and C, it will be about 413 Mbit, which is a huge storage capacity.

Furthermore, the high pixel density digital color image copying system described above is relatively fast; for example, the reading or writing speed of one slip is several tens of nanoseconds (
nsec). For this reason, a high-speed semiconductor memory is required.
If you use high-speed static RAM (random access memory) of
In the case of three image memories, the number of high-speed static RAs is 750, which has the disadvantage that the scale and manufacturing cost are enormous. Therefore, an inexpensive digital color image processing system can be created by connecting a color image information reading device that digitally reads color images and a digital color printing device that digitally prints the read color images without using a host computer. This has been difficult in the prior art for the reasons mentioned above.

〔the purpose〕

In view of the above-mentioned conventional problems, the present invention satisfies high pixel density and high speed by reading and printing color images at the same time, and achieves digital processing without the intervention of an expensive host computer and without image memory. The purpose is to provide a color image processing system for IS, and in particular to provide a synchronous control method that solves the problem of superimposition of four colors, Y, M, C, and BK, which are a major technical element. shall be.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.
- FIG. 1 shows an example of a schematic internal configuration of a digital color image processing system according to the present invention.As shown in the figure, the system has a digital color image reading device R (hereinafter referred to as
It has a digital color image printing device (hereinafter referred to as a color printer) 2 at the bottom. This color reader 1 reads color image information of a document for each color using a color separation means to be described later and a photoelectric conversion element such as a CC port, and converts it into an electrical digital image signal. The color printer 2 is an electrophotographic laser beam color printer that reproduces a color image in each color according to the digital image signal, and records the image by transferring it to recording paper multiple times in the form of digital dots.

First, an overview of the color reader I will be explained. 3 is the manuscript, 4
is a document scanning unit that scans the document 3. The document scanning unit 4 includes a rod array lens 4, a same-magnification color separation line sensor (color image sensor) 6, and an exposure lamp 7. 8 is a wiring cord for the original scanning unit 4; 9 is a cooling fan; and 10 is an image processing section connected to the original scanning unit 4 through the wiring cord 8.

When the document scanning unit 4 moves and scans in the direction of arrow A in the figure to read the image of the document 3 on the document table, the exposure lamp 7 in the document scanning unit 4 is turned on at the same time, and the reflected light from the document 3 is transmitted to the rod array. The light is guided by a lens 5 and focused on a same-magnification color separation line sensor 6, which is a color information reading sensor.

Further, 21 is an actuator provided at the bottom of the document scanning unit 4, and 22-1 and 22-2 are position sensors that detect the scanning position of the document scanning unit 4 via the actuator 21, and are composed of microswitches and the like.

Next, an outline of the color printer 2 will be explained. Reference numeral 11 denotes a scanner, a laser output unit (see FIG. 5) that converts the image signal from the color reader 1 into an optical signal, a polygon mirror 12 of a polyhedron (for example, a dodecahedron), and a motor (not shown) that rotates this mirror 12. ), an f/θ lens (imaging lens) 13, etc.

14 is a reflecting mirror that changes the optical path of the laser beam, and 15 is a photosensitive drum. The laser beam emitted from the laser output section is reflected by the polygon mirror 12, and is reflected by the lens 13 and the mirror! 4, the surface of the photosensitive drum 15 is scanned planarly to form a latent image corresponding to the original image.

In addition, 17 is a primary charger, 18 is a full exposure lamp, and 23
is a cleaner section that collects residual toner that was not transferred;
Reference numeral 24 indicates a state before transfer (1; 1), and these members are arranged around the photosensitive drum 15.

2B is a developing unit that develops an electrostatic latent image formed on the surface of the photosensitive drum 15 by laser exposure;
31Y, 31M, 31C, 318, photosensitive drum 1
Developing sleeve that directly develops in contact with 5, 30Y, 30
M.

30G and 30BK are toner hoppers that hold spare toner, and 32 is a screw that transports the developer. For example, when forming a yellow toner image, yellow toner development is performed at the position shown in this figure, and a magenta toner image is formed. When forming the magenta developing device, the developing unit 2B is rotated around the axis P in the figure, and the developing sleeve 31M in the magenta developing device is placed at a position in contact with the photoreceptor 15. Cyan and plaque development work similarly.

Further, 16 is a transfer drum that transfers the toner image formed on the photosensitive drum 15-A onto paper, 18 is a 7-cut unit plate for detecting the moving position of the transfer drum 1B;
By contacting this actuator plate 13, the transfer drum 16 moves to the home position 2.0. 25 is a transfer drum cleaner, 27 is a paper press roller, 28 is a static eliminator, and 29 is a transfer charger, and these members 19, 20, 25, 27.
29 is arranged around the transfer roller 18.

On the other hand, 35.38 is a paper feed cassette that stores paper (paper sheets), 37.38 is a paper feed roller that feeds paper from the cassette 35.38, and 39.40.41 is the timing of paper feeding and conveyance. The paper fed and conveyed via these timing rollers is guided by the paper guide 49, and its leading edge is held by a gripper (see 51 in FIG. 5), which will be described later, and wraps around the transfer drum 16, forming an image. Shift to the formation process.

50 is a peeling claw that removes the paper from the transfer roller 16 after the image forming process is completed; 42 is a transport belt that transports the removed paper; 43 is an image fixing unit that fixes the paper that has been transported by the transport belt 42; The image fixing section 43 has a pair of heat pressure rollers 44 and 45.

Next, the embodiment shown in FIG. 1 will be described in further detail with reference to FIG. 2 and the following drawings.

The above-mentioned equal-magnification type color separation line sensor 6 is illustrated in FIG. 2 (
As shown in A), each pixel consists of 5 chips with 1024 pixels arranged in a staggered manner, with the area of 62.5-inch (1/18-■) corner as one pixel. , the same figure (B
) As shown in the figure, it is divided into three parts according to the size of the approximately 20.8g × f12.5g cabinet, and each of the three divisions is marked with B (blue).
, G (green), and R (red) color separation filters are attached, and when reading the image, the document is scanned in the direction of the arrow in Figure 2 (A), and the color separation image of document 3 (see Figure 1) is scanned. read.

FIG. 3(A) shows each color separation image data read by the 5-chip equal-magnification color separation line sensors (hereinafter referred to as color reading sensors) 101 to 105 arranged in a staggered pattern as 8-bit images. An example of a circuit configuration for quantizing digital data and inputting it to a color correction circuit (see FIG. 4) and an image data processing circuit (see FIGS. R9 and 10), which will be described later, is shown.

First, analog pixel signals color-separated into R, G, and H color components of the document 3 by the color reading sensors 101 to 105 described above are amplified by first-stage amplifiers 108 to 110, and are amplified by logarithmic (log) conversion circuits 111 to 110. 115, it is converted into a pixel density value. At this time, each image signal is serially colored in the order of R1-, G1→B1, in synchronization with the pixel signal transfer lock (CLK) 201, as shown by Ag202 in the timing chart of FIG. 3(B). Output from the reading sensor.

Next, sample and hold circuits (S/H) 118 to 12
0, the sampling signal S/HP shown in FIG. 3(B)
The input image data is sampled and held at timing 203, and then A/D converted by analog-to-digital (A/D) converters 121-125.
(bit), quantized into 256-level image data.

In this way, the color-separated and quantized image data is transferred serially in a time-division manner, as shown by DATA204 in the timing chart of FIG. 3(B). Data DATA204
In order to perform color correction processing using a color correction circuit (see Fig. 4) which will be described later, each DJ and DC of DATA 204 must be
+, OB+, (here, R, G, and B correspond to red, green, and blue, respectively. The same applies hereinafter) must be aligned in the same phase in advance.

Therefore, a latch pulse with a temporal phase difference is used.
LPR+ 205. LPG+ 208. LPB +
DATA204 DJ, DC+ by 207
, DB+ --- sequentially latch circuits 128 to 13θ
The latch outputs LPR, LPc, and LPa of these latch circuits 128 to 130 are latched to the latch pulse (L
GH) 208 makes the latter stage latch circuit! It is latched to 31. As a result, the latch circuit 131 finally latches the color separation data of the same pixel in the same phase.

Furthermore, since the color reading sensors lot~105 are arranged in a staggered manner as shown in FIG. The data for each color is buffered and output to the next role as one continuous line of image data OR, DC, and DB for each color of R, G, and H.

The phase-aligned 8-bit color separation image data DR9DC and DB for the same pixel obtained as described above are subjected to predetermined processing by the circuit shown in FIG. That is, the color correction circuit 135 in this figure performs the process disclosed in item 0 below, which is usually called masking, and
The plate generation and undercolor removal circuit 136 performs the processing disclosed in the following section (2).

(0 masking process - 111 The color correction circuit 135 performs matrix @ calculation shown by the following equation (1) on the input pixel data OR, DC, DB 301 to 303 to absorb unnecessary color components of printing toner. Do the following.

Here, the coefficients ai, bi, and ci (i=1 to 3) are masking coefficients that should be set to appropriate values. Also, Y
, M, and C are output signals 304 to 3013 corresponding to the colors yellow, magenta, and cyan.

(2) Corner plate generation and undercolor removal processing--1--In the corner plate generation and undercolor removal circuit 136, the above-mentioned signal Y is input.

Minimum value of M and C WIN (Y, M, C) = k (constant)
Then, Y' = Y - α, M' = M - β, C
Toner amount Y' to be printed by calculating '=C-γ'
, M', C' 307-309, and further BK(
The signal BK=δk 310 of black) is used as a corner plate for black printing. Here, it is assumed that the coefficients α, β, γ, and δ are set to appropriate values in advance.

Next, each image data Y' obtained by the circuit 13B described above
, M', C', BK 307-310 are
This becomes the basic data of the toner image that is finally printed by the printer 2, but as described later, in a single system color printer, the toner image of Y (yellow) and the toner image of M (magenta) are , C (cyan) toner images and BK (black) toner images cannot be printed out simultaneously on transfer paper, so each toner image is transferred to transfer paper in sequence and the four colors are superimposed one after another to create the final image. Since this is a printing method for obtaining a color print image, it is necessary to select each color data Y', M', C', and BK obtained by the circuit 13B described above in accordance with the operation of the color printer 2. .

The next stage selector 137 is for this selection, and the selector 137 selects the above-mentioned four types of image data Y'.

Select one image data from M', C', and BK307-310. Therefore, in this system, 1
Reading and printing out one color image original requires four original exposure operations and four toner image forming processes. Now, the color separated image 311 selected by the selector 137 described above in response to the operation of the color printer is separated into a character area 313 and a halftone image area 132 by the image area separation circuit 13B, and a halftone image is created. 312), the multi-value processing circuit 139 performs multi-value processing (usually referred to as dither processing), and for the character area 313, the binarization processing circuit 140 performs binary processing using single-rice processing. This converts the image data transferred in 8 bits and 256 gradations mentioned above into dot image data 314° 3!5 of 1", "O". This dot image data 314° 315 is an OR gate. 141 and input to the synchronous memory 142.

Synchronous memory! Reference numeral 42 denotes a buffer memory necessary for sequentially printing out color-separated images read simultaneously with original exposure scanning according to the present invention without color shift;
1 is a synchronous memory controller that controls this synchronous memory 142. Before explaining the functions of these 142 and 143, an outline of sequence control of the color printer 2 will be explained.

First, the image forming process of the laser beam color printer 2 of FIG. 1 will be explained according to the schematic diagram of FIG. 5.

The color-separated image signal read by the color reader I described above is developed into dot image data (dot data) through each circuit shown in FIG. 4, and the dot data corresponding to this color image is finally The laser beam LH is modulated by the laser output section 11L shown in the figure.

The laser beam LB modulated in accordance with the image data is directed by the polygon mirror 12 rotating at high speed in the direction of arrow A-- in FIG.
A beam of laser light is scanned horizontally at high speed with a width of
The horizontal scan corresponds to one horizontal scan of the original image, and in this embodiment, the width is 1/18a+m.

On the other hand, since the photosensitive drum 15 is rotating at a constant speed in the direction of the arrow in the figure, the above-described laser beam scanning is performed in the main scanning direction of the drum, and the photosensitive drum 15 is rotated in the sub-scanning direction of the drum. As a result, a plane image is finally exposed to light and a latent image is formed. For example, if development is performed with yellow toner on the developing sleeve 31Y in response to the first original exposure scan in the color league, the toner image will be formed on the photosensitive drum 15.
A toner image corresponding to the yellow component of the document 3 is formed.

Next, the photosensitive drum 15 is placed onto the paper sheet 54 whose leading end is carried by the gripper 51 and wrapped around the transfer drum 16.
A yellow toner image is transferred and formed by a transfer charger 29 provided at a contact point between the transfer drum 1B and the transfer drum 1B. The same processing process is applied to M (magenta), C (cyan), BK
By repeating the (black) image and superimposing each toner image on the paper sheet 54, a full-color image using four color toners is formed.

Thereafter, the sheet of paper 54 is peeled off from the transfer drum 1B by the movable peeling claw 50 shown in the first factor, guided to the image fixing section 43 by the conveyor belt 42, and heated by the thermal pressure rollers 44 and 45 of the fixing section 43. The toner image on the leaf 54 is fused and fixed.

Next, Y, M according to the above color league l.

The color separation images corresponding to the C and BK toner images are read repeatedly, and the above-mentioned Y, M, C, and 8 toner images are sequentially color-shifted onto the paper sheet 54 carried on the transfer drum 1B in the color printer 2. Control of image reading and image printing timing in order to perform overlapping transfer with high precision without any problems will be explained with reference to FIG.

In FIGS. 6A and 6B, T is the leading edge of the color original 3. In FIGS. The reflected light from the surface of the color original 3 is guided to the rod array lens 5 of the scanning unit 4 and formed into an image on the same-magnification color image sensor 6.

As the scanning unit 4 moves in the direction of the arrow in the figure, the sensor 6 sequentially reads images.

On the other hand, an actuator 21 is attached to the lower part of the unit 4, and a home position sensor (SRI) 22-1 and a mouth top sensor (Slh
) At position 22-2, the position signal is obtained.
Normally, stopping is performed based on the output signal of the home position sensor 22-1. ! DTO to read X draft
This is done based on the signal from the P sensor 22-2.

In the color printer section 2, an image is written at the laser exposure position PH of the photosensitive drum is, I:. Also,
A position sensor (SP+) 20 (hereinafter referred to as an OP sensor) fixedly installed on the main body on the circumference of the transfer drum IB and an actuator plate 19 attached to the transfer drum IB are connected to the i5V! arranged as shown in i,
The tip of the paper sheet 54 to which the toner image is transferred is a 7-cutting plate! 8 is held by a gripper 51 at a point a.

In addition, the length of the ridge of 7 pieces of wood and 1 g of wood is fixed l +
The HP sensor (S
RI') 22-1 and mouth TOP sensor (SR?) 2
It is slightly longer than the distance between 2-2.

First, when the position sensor (SP, ) 20 detects the tip edge a of the seven cutter plates 13 on the transfer drum L6, which is rotating at a constant speed in the direction of the arrow in the figure (counterclockwise direction), the document scanning unit 4 6(A)), when the exposure scanning unit 4 reaches the TOP sensor (SR2) 22-2, the document is read and the synchronization memory 142 (see FIG. 4) is started. Start writing to. That is, in the synchronous memory 142, the color separated image that is started to be read from the leading edge T of the document is stored line by line.

On the other hand, on the printer 2 side, when the rear edge of the seven cutter plates 18 on the circumference of the transfer drum 18 is detected, reading from the beginning of the synchronization memory 142 described above is performed from the time when the rear edge b is detected, and accordingly, the radar light Photosensitive drum 1 by modulation
Writing of the image to 5 is started (FIG. 6(B)).

From the laser exposure position PH on the photosensitive drum 15 to the transfer position i
Since the distance to Tr and the distance from the leading edge of the paper to Tr are set equal in advance, each line is written on the photosensitive drum 15 from the leading edge T of the original 3, and the leading edge of the original 14AT The synchronization memory 142 in the system of this embodiment has a capacity for 48 lines, that is, 1 line.
When reading an image at a scanning density of 8pel/+wm, 3■
■It has a storage capacity equivalent to the width.

The role of this synchronous memory and the reason for its storage capacity of 48 lines will be explained below.

In order to obtain a color image without color shift, as detailed above, the yellow component image of document 3 is first read and a yellow toner image is formed, and then the magenta component image is read. and a magenta toner image is formed, then a cyan component image is read and a cyan toner image is formed, and finally a black component image is read and a black toner image is formed, so the beginning of each image is always Accurate overlapping is essential.

Therefore, as described above, when the ITOP sensor 20 detects the tip a of the seven cutter plate 19 of the transfer drum 1B, the exposure scan of the scanning unit 4 is started,
When the DTOP sensor 22-2 detects the leading edge T of the original 3, it starts reading the original image and writing it to the synchronous memory 142, while the rear end of the actuator plate 19
At the same time as being detected by the TOP sensor 20, the synchronous memory 14
2 and writes the image to the photosensitive drum 15.

However, since the transfer drum 16 rotates at a constant speed, the ITOP sensor (sp, ) 2G detects the tip a of the actuator plate until it detects the rear end, that is, the scanning period is a certain period. Unit 4 is at stop position SR
+ (HP Senna) Start from 22-1 and 5R2 (
As shown in FIG. 7, non-negligible variations occur in the time t until reaching the mouth top sensor) 22-2.

This variation is greatly influenced by conditions specific to the device, such as friction with the main body due to the weight of the scanning unit 4, fluctuations in the tension of the drive wire (not shown), the start-up characteristics of the drive motor, etc.

Therefore, the maximum variation in Figure 7, 4116 times, is the scanning distance and the synchronous memory! In other words, it is necessary to select the capacity of the synchronous memory 142 so that the image data corresponding to the maximum amount of variation can fit in the synchronous memory 142. This Δ
t■a! If the capacity calculated from this device is 48 sentences in
The data capacity is e.

FIG. 8 shows an example of the structure of the above-mentioned synchronous memory 142.
As mentioned above, the scanning unit 4 is a DτOP sensor (SR?
) When the position 22-2 is reached, reading of the original is started, and the first line of the original is written into the synchronous memory 142, and when the rear edge b of the seventh cutter plate 18 of the transfer drum 16 is detected, the reading of the original is started from the first line of the original. Since the image data is read from the synchronous memory 142 and the image is written to the photosensitive drum 15, fmMt7) variation Δ
Intestines a! is absorbed by this synchronous memory 142.

Further, after detecting the tip a of the seven cutter plates 18 of the transfer drum 16 described above, the scanning unit 4 of the color reader 1
After starting, the scanning unit 4 starts reading the leading edge T of the document, that is, the detection of the DTOP sensor 22-2 precedes the detection of the rear end of the actuator plate 13 by at least two lines. If not, synchronous memory 1
The read/write sequence at 42 is reversed and proper synchronization control is not performed.

Therefore, in this system, as described below, there is a delay between detecting the tip a of the seven cutter plate 13 of the transfer drum 16 of the color printer 2 and starting the color reader 1 (7) scanning unit 4. A delay means for providing a time (delay).

A delay means is provided to provide a delay time from when the rear end of the actuator plate 19 is detected to when reading of image data from the synchronous memory 142 is started, and control is performed so that proper synchronization processing is performed. ing.

FIG. 9(A) shows an example of the start delay circuit of the scanning unit 4, and FIG. 9(B) shows a timing chart of the delay circuit. After the input of the scanning motor ON signal 212 that starts the scanning motor of 4, the AND condition of the detection signal (ITOP) 211 of the tip a of the 7-couture multi-plate 19 and H5YNC (referred to as horizontal synchronization signal or beam detection signal) is applied. Therefore, the delay counter 151 counts HSYNC by a predetermined number, and the count up signal 21 of the counter 141
5, the flip-flop 153 is set and outputs a scanning motor drive signal 214, thereby starting the color scanning unit 4 (see FIG. 9(B)).

Note that the count value N of the 1 counter 151 that determines the amount of delay is set by the preset switch 152 or the like.

Further, the above-mentioned H5Y and 021G are synchronization signals output from the beam detector 53 in FIG. 5 once for each horizontal scanning line, and are always sent from the color printer 2 to the color reader l. 52 in FIG. 5 is a reflecting mirror.

FIG. 1O shows a configuration example of a delay circuit for reading an image from the synchronous memory 142. When the rear end of the seven cutter plate 18 of the color printer 2 is detected, the detection signal (ITO
P) 211 sets the flip-flop (F/F) 154 and starts the counting operation of the counter 155.

The counter 155 counts HSYN(:210) generated by the beam detector 53 (see FIG.
At the same time as resetting F154, the subsequent F/F157
is set, and the read operation start signal 21B of the synchronous memory 142 is output from the subsequent F/F 157. counter 15
The set value of 5 is set to an appropriate value by the preset switch 15B.

Based on the set values of the counter means 151 and 155 described above.

Variations in the time from the start of writing image data to the synchronous memory 142 to the start of reading image data, that is, when the scanning unit 4 starts from the HP sensor 22-1 position and DT
The pattern Δtmax of the time required to reach the position of the OP sensor 22-2 is 48 fL in terms of memory line.
2 in front and back based on the standard position so as to fit within
The synchronous memory 142 is set in advance to have a difference of 49-+ne (see FIG. 8).

Therefore, the variation at this time is +24 line and -2 line.
Since it is possible to absorb up to 47 lines of 3 lines, appropriate memory synchronization control is always performed.

〔effect〕

As explained above, according to one aspect of the present invention, the time point at which the color image reading means starts reading the leading edge of the image is arranged to be earlier than the time point at which the color image printing means starts writing out the leading edge of the image. , BK can be superimposed without any color shift, and it is also possible to read and print color images at high speed and almost simultaneously with high pixel density using an expensive host computer and large-capacity image memory. can.

[Brief explanation of the drawing]

FIG. 1 is an internal configuration diagram showing an example of a digital color image processing system to which the present invention is applied, and FIG. 2 (A) is an arrangement showing an example of the same-magnification color separation line sensor in the document scanning unit shown in FIG. Configuration diagram, FIG. 2(B) is an explanatory diagram showing an enlarged view of the main parts. FIG. 3(A) is a block diagram showing a configuration example of a color image reading circuit, FIG. 3(B) is a timing chart showing signal waveforms of the circuit, and FIG. 4 is a circuit for correcting and synchronizing color image signals. FIG. 5 is a perspective view showing in detail the main parts of the printer portion of FIG. 1; FIGS. 6(^) and 6(B) are operational diagrams of the system shown in FIG. 1. Fig. 7 is a characteristic diagram showing temporal variations in the sensor output, Fig. 8 is a layout diagram showing an example of the configuration of the synchronous memory shown in Fig. 4, and Fig. 9 (A) is a start delay of the scanning unit shown in Fig. 1. 9(B) is a timing chart showing the signal waveform of FIG. 9(A); FIG. 10 is a circuit diagram showing an example of the circuit configuration; FIG. FIG. 3 is a circuit diagram showing a configuration example. 1...Color league (digital image reading device M), 2.
... Color printer (digital image printing device), 3... Original, 4... Original scanning unit/to, 6, 101, 105... Same-magnification color separation line sensor (color image sensor), 11. ...Scanner. 15... Photosensitive drum, 18... Transfer drum, 18... Actuator plate, 20... Position sensor, 21... Actuator, 22-1.22-2... Position sensor. 28...Developer unit, 29...Transfer charger, 30Y, 30, 300, 30BK...Toner hopper. 31Y, 31M, 310, 318K...Developing sleeve, 51...Gripper, 54...Paper body. ! 42...Synchronous memory, 151.155...Counter, 152.158...Preset switch. Figure 5 Figure 6 (A) Figure 7 H Seni →--C) TOP,.

Claims (1)

[Scope of Claims] 1) Color image reading means for reading each color component of an original image and sequentially outputting color image data digitized for each pixel for each color; and a monochrome image for each color according to the image data. color image forming means for recording a full-color image on a recording medium by superimposing the single-color image; and a delay means for adjusting the time when the color image reading means starts reading at the leading edge of the image from the color image. 1. A synchronous control method for a color image processing system, characterized in that the method is configured to form an image in advance of the point in time when an image is formed at the leading end of the image forming means. 2) In the method described in claim 1, the accuracy of mechanical position control of the color image forming means is ±x (mm
), the delay means controls the image leading edge formation start reference of the color image forming means to be delayed by at least x (mm) than the image leading edge reading start reference of the color image reading means. Synchronous control method for color image processing system. 3) In the method described in claim 2, when the image density of image reading and forming is N (pel/mm), a synchronization buffer memory with a storage capacity of at least 2N_X runs is provided; A synchronous control method for a color image processing system characterized by forming an image via a buffer memory.