JPS59170865A - Color reproducing device - Google Patents

Abstract

PURPOSE:To perform preferable image reproduction and character reproduction by processing image data and outputting a color signal, and selecting and controlling real-time half-tone reproduction processing on the basis of the image data. CONSTITUTION:A buffer memory M2 is stored with dots from a CG corresponding to picture elements of image data, one to one. Then, an address counter ADC2 decides on a character synthesis position in a color image. When specific image processing reaches preset coordinates X and Y by a signal input source 201, a read of the memory M2 is started to synthesize a character output from a color reproduction output corresponding to a position after dither processing. Then, a specific-level signal which voids a character image from a background color when an image is in dark background color or paints the character image in black when the tone is high is outputted. This signal is inputted to an OR gate 210 and synthesized with image data after the dither processing. Thus, the preferable image reproduction and character reproduction are realized.

Description

[Detailed description of the invention] The present invention relates to a color reproduction device.

There are known devices that process image data having color components and print out color images.

In this case, it is known that dither processing is performed on the data in order to reproduce halftones, but since this essentially impairs resolution, we decided to perform dither processing only in the necessary areas. Improvements have been reported. However, this method is inconvenient in practice because it requires a complicated circuit and time-consuming processing to determine the density difference in the l-region in advance.

Furthermore, if it is desired to insert characters or the like into the reproduced color floor, it is necessary to read the transparent character bones over the document when reading the color document. This is extremely inconvenient.

The present invention eliminates this drawback and enables more preferable image reproduction and single character reproduction.

FIG. 1 shows this embodiment. A document 1 is placed on a transparent plate 2 of a document table and fixed by a document tray. The photosensitive drum 24 and the transfer drum 56 rotate in the direction of the arrow to perform a color process. 12 is a dichroic mirror for spectroscopy, 14,
16.18 is a CCI) that senses spectral light and generates color signals B, G, and B. The rung 8 and mirrors 9 and 10 are moved back and forth to scan the document 1, and at the same time color signals B are sent from each CCU.
,G.

[7, Create a Y signal for reproduction, then output the M signal again using the reciprocating motion, and then repeat the second scan 4 times to form a Y, M, C, BK multiplied signal.7. /--The latent image of each color is formed 11n times on the drum 24). Each color is developed sequentially 2, and the transfer drum 53 is rotated 4 times to repeatedly transfer it to the paper on it, making a full-color copy. Get it.

In the optical system, illumination lamps 5 and 6 also emit light, and a reflecting mirror 7
.
and passes through 12 dichroic filters. Here, the light is split into the original wavelength, green wavelength light, and red wavelength light.

Among the decomposed lights, the molecular light of the omitted wavelength passes through the blue filter 16 and is received by the solid-state image sensor 14. Similarly, light with a green wavelength passes through a green filter 15 and is received by a solid-state image sensor 16. The red wavelength light passes through the red filter 17 and is received by the solid-state image sensor 18. Therefore, the document 6 moves together with the illumination rung 5.6 and the movable reflecting mirror 9. While maintaining the -0 path length through the reflecting mirror 10, the image is further focused on the solid-state imaging elements 14, 18, and 16 of each color via the lens 11 and the electronic filter 12. The Li3 power of each solid-state image sensor 14, 16.
The light output is then irradiated. Polygon mirror 22 is amazing! Since it is rotated by 23, the laser light is scanned perpendicular to the direction of rotation of the photosensitive drum.

A photosensor 64 is located 11 mm before the laser beam starts scanning on the drum, and generates a signal B when the laser beam hits dirt. , ) The Erad 24 is negatively charged by the negative charger 25 which is supplied with a negative high voltage current from the high voltage power supply 215. Subsequently, upon reaching the exposure section 26, the original 1 on the transparent plate 2 of the original table is illuminated with an illumination rung of 5°6, and is exposed to movable reflecting mirrors 9, 10, lenses 11, dichroic filter 12, blue filter i3, and green filter 15. The image output from the CCD, which is imaged on the solid-state image pickup devices 14, 16, and 18 by the red filter 17, is passed through the shading unit 104 for each color by the image processing circuit shown in FIG.
Masking processing unit 10 via correction unit 105
9. After passing through the UCR processing unit 119, the laser light is outputted from the dither processing unit 124, the multilevel processing unit 125, and the laser driver unit 126 to the laser 21, and the laser light is imaged on the photosensitive drum 24. There, an electrostatic latent image is formed and enters the four-color developer 3 (S, 37, 38, 39).Here, six colors are separated in one exposure scan and the above processes are performed. The output is sequentially selected for each scan of B, G, R, and black.When one color separation light signal is selected in the image processing unit 27 according to the E signal (corresponding to the main body control signal ΦCR), the corresponding developer is selected. The selected developing device performs powder development using a magnetic blade method, and the electrostatic latent image is visualized.

Thereafter, it is negatively charged by a ghost lamp 40 for erasing static latent dust and a negative post electrode 41 supplied from a negative voltage power source 25, thereby erasing the electrostatic latent image.

Next, insert the cassette 4, 44, which is two rows below, into the operating section 45, +:
The copy paper 48 fed from the r+i selected cassette by the rotation of the paper feed rollers 46 and 47 is placed on the first roller,
It passes through the lower part 49.50, passes through the conveyance roller 51, passes through the second registration roller 52, and is wound and tied around the transfer drum 55. Thereupon, the toner on the photosensitive drum 24 is transferred onto the copy paper 4B by the transfer electrode 54. After the transfer has been completed, the photosensitive drum 7-24 removes the static electricity from the copy paper 4B by using the remover 71 (electrode 55) supplied with a high voltage from the high voltage generator 25.

In the case of a normal color original, the above operation is repeated four times for four colors, and the transfer drum is rotated four times to overlap each color. If the original has only one color, black, as described later, when it is detected that the original has only one color, black, after one optical movement is completed, processes such as G, R, scanning, development, transfer, etc. will be started. It jumps and starts copying the black image. In other words, in the case of a color original, the operation time for four colors is required, but in the case of an original of only one color, black, the operation time can be shortened to the time for two colors or one color of t. The copy paper on which two or four transfers have been completed is scraped from the gripper 5/, adsorbed onto the belt 59 by the conveyor fan 5B, guided to the fixing section 60, fixed thereon, and sent out of the machine.

2 and 6 show I[lj1 image processing circuit diagrams.

When the original light from the dichroic filter is irradiated with DI4, 16.18 using an EC, the light from the original that has been converted into one molecule of five colors is amplified by the CCD boards 101, 102, 103.
) Converted to the next shedding unit) 104 to 8 bits) Sent in parallel. When the incident sight of the CCD is - (when it is white), the output data for each bit of the CCD is equal, and the CCI for 6 more colors) 14, 16
, 18 is corrected so as to eliminate the dispersion.) 104 is a RAM configuration, and data is used as an address for proper output.

Next, the r correction unit 105 linearizes the gradation between the crowds (the optimal γ curve is set by the switches 106 and 10).
7, select by changing the value of 108 by 17J/).

, l\5j, 17 times from 8 bits to the upper 6 bits), it is impossible to process in the unique l novel area.

Next, each B is processed by masking processing unit l-1[)9.

Process the Q and R signals at the same time -'') and calculate each color component σ)
Perform color correction by changing the mixing ratio 6. Difficulty) The effect is multiplied by the number of threads.
This is because the calculated values are set to the upper 4 bits and the P L is also limited to a significant area level.

Next, in the UCR and processing unit 119, 13
, G.

3. The minimum value signal of H is determined. σ) The value obtained by multiplying the minimum value signal by an arbitrary coefficient depending on the value of the switch 120 is set as the black A-signal. The value is subtracted from the name and color of each UCRK, and the (g) is branched into two systems, one is the select signal 121 from the main body control section, and the signal for one color is 122.125 and 19 from the dither processing unit. Send to 124 1'
−) to be. In the dither processing unit 124, each color signal is a deep signal, for example, a 6-bit signal is dithered by referring to the table 1? Using OM, one bit of 1 is converted into a digital 15f signal of O in the comparison I to make it easier to modulate the laser. Next, this signal passes through the in-memory and is multi-valued by a multi-value processing unit 125, and is driven by a multi-value processing unit 126. In addition, dither processing units with low threshold levels were arranged) (OMl
, high sequence IIM3, medium R(-,)M2
, simultaneously compares the input signal with these ROM outputs, and latches the output of each comparator into memory;
Then, one pixel is divided into six equal parts. In other words, the 1111ii element is φ1
It is separated by pulses of different widths of ~φ6 and sent. Memories 128-1, 128-2, and 128-5 are at address 60,
θ is stored in addresses θF to θF, 1 is stored in addresses 10 to 2E, and θ is stored in addresses 2F to 6E. The 6BiT signal input to the memory 13128-1 depends on the intensity of the light input to the CCD when there is a lot of light (original density is low)
The θθ of θθ also changes in 64 ways up to 6F when the original is low (high density of the original) -5-3°.As an example, θθ~θF (low density when i-'j, Shingetsu from 10 to 2E) When the signal is medium concentration, 2F to 6F signal σ) is set to extra high concentration Iba. When an intermediate density signal is input to memory B, it outputs 1, otherwise it outputs θ.

This is synchronized with the clock by the latch circuit 129 and
Input 00 and reset the outputs Q1 to Q3.

If there is an intermediate density signal even once in the first optical scan,
The hold circuit outputs 1, and as a result, the output 140 of the OR gate becomes H. The control circuit 69 (FIG. 1) checks this signal immediately after the optical scan is completed 202.
If 3 is an H signal, the control circuit 69 switches the selectors 141 to 145 to the de and isa sides using the switching signal 144 (step 204), and performs dither processing, and if it is an L signal, the selectors 141 to 146 are fixed by the switching signal 144. Switch to the data side (step 205) (dither processing)
-f-ru.

As this first optical scan, dither selection control can be performed in advance by pre-scanning the image at high speed (without forming a reconstructed image) instead of the main scan that directly precedes the formation of the reconstructed image.

The range in which the density is still determined to be intermediate can be freely determined by switching memories with different storage patterns for 1 and θ.

Add or replace a circuit like that shown in FIG. 5 to x, y, and z in FIG. 2, and input the BD double signal from FIG. , By inputting an appropriate count value (for example, if there is an intermediate density area every 4 lines, dither processing can be performed sequentially. Therefore, dither selection control can be performed for each area. A high-resolution print can be obtained by dithering a high-density document and not dithering a high-gradation print without intermediate density.

Note that the present invention is effective even if the input signals of B, G, and I (, ) in FIG. 2 are from the host computer,
Also, at the connection points of X, Y, and Z, it is possible to switch between the host and the CCD league as necessary. In this case, if a command signal without halftone is attached to the beginning of the transmission signal from the host, the selector can be controlled to determine if this is the case and to omit the dither processing. The present invention can also be applied to 1-pixel, 4-dot type Zolinta, thermal printers, and inkjet printers.

In this example, when dither processing is omitted, the pulse rlj modulation of the 1/-the drive signal using the four values mentioned above is used, so some intermediate tones can be reproduced, and low-level intermediate tones (
At the end of the day, it is possible to reproduce the Daizaomitsu) (there is a lifting platform that is closed). Further, it is possible to make a determination every few pixels, and to perform the above-mentioned partial selection control with accurate synchronization.

FIG. 6 is a circuit diagram for inserting characters, numbers, etc. into the above color image.

700 is code generating means for generating characters and numerical values as code data; Ml is a buffer memory that stores the code data at the same time as the code is generated; A1) C1 is controlling the address for writing and reading the memory; C() is a well-known character generator that outputs characters and numerical values as dot pattern image data based on the code data read from the memo υM1, and M2 is a C
The dot data from a is also stored in the backup memory at the same time as it is output, and is stored so that one dot of cG corresponds to one pixel of one image data, that is, dot patterns for multiple characters and numbers are stored for each character and each character. The numerical values are stored at predetermined intervals similar to the reproduced image. Al) C2 is memo IJ M,
This is an address counter that controls the address for writing and reading data in step 2, and also determines the timing of starting reading in synchronization with the processing progress of color image data. position can be determined. 201 is a signal input source for presetting the timing, and when the image processing shown in FIG. 2 reaches the preset coordinates X and Y by 2o1, reading from the memory M2 is started;
The character output is synthesized from the color reproduction output corresponding to the above-mentioned position after dither processing.

205 is a gate that outputs a CG dot output as H (black) when the output of the comparator 206 is L (white, halftone);
4 is an inverter that outputs L (white) when the output of the comparator is H (black). The comparator 206 outputs L when the output A of the black component shown in FIG. 2 is above a certain level Ij i and below 11. Therefore, if the image has a dark background color, in order to make the character image from CG white from the background color,
If the tone of the text is bright, the character image may be blackened by 4", and a signal of the above level may be output by 1". This signal from B is input to the OR gate 210 in FIG.
In this case, the inserted characters are not dithered, so there is no loss of resolution.

The +6i signal is a write signal, and the read signal from the memory M2 is applied to a black scan and a black process in synchronization with the black processing process, and is outputted to form black characters. If the color image is a monochromatic image of blue, and if you want to insert a character in red, the red processing step is further executed and the readout signal is synchronized with the red processing so that the B signal is output only during that step. granted to.

The address counter Al)C2 is used as a driver for image data processing to determine the timing to start reading from the memory M1.
CLK) and lines, and when the count value reaches the preseller l-X, Y by 201, start reading the memory M2 in synchronization with the clock CLI (.The dot count means that the bits are one line. Counting starts for each end signal, and the line count is determined by the beam detection signal in the laser scanner indicating the end of one line scan or by the key attached to the copying machine shown in Fig. 1 or by the transmission line as shown in Fig. 7 for one line. ff1 to M1
When the 984J code is stored, the CG converts it into a corresponding dot pattern and stores it in the memory M2. After that, the color data processing mentioned above becomes possible (in this example, it becomes possible to scan the document using the optical system. Until then, it is prohibited unless a command is input to indicate that there is no insertion paper). Color data When the process starts and reaches the preset coordinates X and Y of 201 in the Brax Gyan process,
Start reading 1~ of memory 1JM2 and use the character B signal CLK.
The latent image of blank characters is formed on the drum, and is transferred and combined with the previous color image to obtain a color print with characters. If necessary, characters in other colors such as red and blue can be inserted as described above.

However, when a character is added to a position where part of the ground is a dark color (black) like ■, the background is automatically determined from the signal A and a white character signal is formed as described above. B
Output as . This procedure provides accurate synchronization and circuit configuration for color image processing so that it can be accomplished in real time. The preset data 201 can be obtained using the key of the copying machine shown in FIG. 1 or the transmitted code data. It may be a memory I[)M that stores the format as 200.

By the way, in cases where the base color is repeated in a short range, such as in a striped pattern, processing the white areas accordingly may make it look unsightly.In order to eliminate this inconvenience, a delay circuit is provided at point W in Figure 5. It is possible to perform whiteout only when the background in a predetermined range is dark.

By the way, if you want to add all characters in white, use memory M2 to handle it in the color image processing process at that time.
The read timing can be determined.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a color copying machine to which the present invention can be applied; FIGS. 2, 6, 5, and 6 are circuit diagrams of an image processing section;
FIG. 4 is a flowchart for halftone determination, and FIG. 7 is an explanatory diagram of a raw image. 14 opening 85:) ~ 1ν (1865 (7) 64 Sono)

Claims (4)

[Claims] (1) A color reproduction device comprising: input means for image data; means for processing the image data to output a color signal; and means for selectively controlling real-time halftone reproduction processing based on the image data. (2) A color reproduction device according to item 1, wherein the color of the inserted character is determined based on the type of image data. (3) The color reproduction device according to item 1, characterized in that characters inserted into dark areas of the image are reproduced in bright mode. (4) The color reproduction device according to item 1, characterized in that the inserted characters are reproduced in black and, if necessary, in other colors.