JPH03271772A - Image forming device - Google Patents

Abstract

PURPOSE:To form an image by binarizing only desired color information by separating an inputted color image into color information of more than two colors, and binarizing the desired color information from the separated color information. CONSTITUTION:The color image from an image inputting means is separated into the color information of more than two colors. That is, reflected beam from an original 999 is passed through a half mirror 20a, and formed as image on a CCD line sensor 20c by a lens 20b, the CCD sensor 20c is constituted from a line sensor with a red optical filter fitted in and a line sensor fitted with a cyan optical filter, for example, each are outputted as signal R and a signal C, and each are inputted to a controller part 2a as analogous electrical signals. Then, the controller part 2a is operated to form the image by binarizing the desired color information from this separated color information. Thus, the image is formed by binarizing only desired color information from the color image.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that binarizes only desired color information among color information to form an image. [Prior Art] Conventionally, when copying a color original with desired color information, an area containing the desired color information is first specified using an indicating means such as a digitizer. The desired color information was copied by using a method of masking areas other than the specified area. [Problems to be Solved by the Invention] However, in the above-mentioned conventional methods, it is difficult to copy the desired color information when the desired color information and other color information overlap or are close to each other. . The present invention was developed to solve the above problems, and
An object of the present invention is to provide an image forming apparatus that binarizes only desired color information of a color image to form an image. [Means for Solving the Problems] In order to achieve the above object, an image processing device of the present invention has the following configuration. That is, an image input means for inputting a color image, a color separation means for separating the color image from the image input means into color information of two or more colors, and a method for extracting desired color information from the color information separated by the color separation means. It has a binarization means for binarizing, and an image forming means for forming an image according to the color information in the binarization means.

[Operation] In the above configuration, a color image is read and the image is separated into color information of two or more colors. Then, it operates to binarize desired color information from the separated color information to form an image. DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Description of Structure> FIG. 1 is a sectional view showing the structure of an image forming apparatus according to an embodiment, which includes a copying apparatus main body 1, a document scanning section 2. Paper feeding section 31 image recording section 4. It is composed of an intermediate tray section 5 and the like. First, the configuration of the document scanning section 2 will be explained. Reference numeral 2a denotes a controller section, which is composed of a control section that controls the copying sequence in general, and an image processing section that performs image processing on the image signal read by the CCD line sensor 20c. 2b is a power switch, 2c is an original exposure lamp, which consists of a scanning mirror and an optical scanning type, and scans at a predetermined speed. * 20a is a half mirror, and the passing light is COD.
It passes through the imaging lens 20b, is photoelectrically converted by the CCD line sensor 20c, and is sent as an image electrical signal to the image processing section of the controller section 2a (details will be described later).
. Further, the reflected light from the half mirror 20a is filtered through a red filter 20d for removing red color or a blue filter 20e for removing blue color.
Alternatively, there are cases where no filter or shutter is used, but the light passes through them. 2d is an imaging lens that forms an image of the reflected light on the photosensitive drum 11 of the image recording section 4 (analog image recording). Reference numeral 2e denotes a buzzer, which notifies a user of a copy mode error set on an operation unit, which will be described later, as a warning. 2f is an optical system drive motor (optical motor), which drives the optical scanning system etc. with high precision. Next, the paper feed section 3 will be explained. 3a and 3b are paper feed rollers, and these paper feed rollers 3a,
By driving 3b, the cut sheet SH is fed into the image forming section 4. Next, the configuration of the image recording section 4 will be explained. Reference numeral 12 denotes a registration roller, which temporarily stops the cut sheet SH fed by the drive of the paper feed rollers 3a and 3b, synchronizes the alignment of the leading edge of the image, and then cuts the sheet again.
Feed SH. Reference numerals 13a and 13b are development units, in which developers for different colors (
red, black), and the solenoids 14a, 14
By driving b, one of the developing units 13a and 13b is selectively disposed close to the photosensitive drum 11, and the other is disposed away from the photosensitive drum 11. In addition, when performing multiple development, the controller section 2a controls the solenoids 14a and 1.
Controls the drive of 4b. 15 is a transfer charger, and the above-mentioned developing unit 13a,
The toner image developed by 13b is cut into a cut sheet SH
After the transfer, the photosensitive drum 1 is transferred to the photosensitive drum 1 by the separation charger 16.
1. Separate Cut Sea)-SH from 1. 17 is a pre-exposure lamp, which neutralizes the surface potential of the photosensitive drum 11;
Prepare for primary charging. 18 is a cleaner device, which is composed of a cleaning blade and a cleaning roller;
Toner remaining on the photosensitive drum 11 is collected. A fixing device 19 fixes the toner image transferred to the cut sheet SH by heat and pressure. A transport roller 20 transports the cut sheet SH, which has undergone the above-described fixing process, to the paper discharge tray 24. Further, in the case of multiple copying, the flapper 21 is switched to the position shown by the dotted line by driving a solenoid (not shown), and paper is fed and transferred. The separated and fixed cut sheet SH passes through the conveyance path 22 and is sequentially conveyed to the conveyance path 22a, and after the paper is detected by the sensor S5, it is detected by the sensors S6, 58, etc.
Lateral positioning is performed by a solenoid for lateral registration alignment. Then, the registration rollers 12 are driven by a multiple copy command from the operation unit 41, and the cut sheet SH is sent to the position of the registration rollers 12. Thereafter, the paper is ejected to the paper ejection tray 24 in the same manner as described above. In addition, during double-sided copying, the transfer sheet is partially ejected by the ejection roller 23 in the same manner as in the normal copying operation described above, but after the trailing edge of the cut sheet SH passes through the flapper 21, the transfer sheet is ejected from the ejection roller 23. is driven in reverse, and the cut sheet SH is guided by the flapper 21 and transferred to the conveyance path 22.
will be introduced to. This reverse rotation drive is performed by a solenoid that controls forward and reverse rotation. The subsequent operations are the same as in the case of multiple copying described above. As mentioned above, in the case of double-sided copying, the - degree paper ejection roller 2
3 to the outside of the machine, the cut sheet SH is reversely driven by the reverse rotation of the paper ejection roller 23, and is then transported in the transport direction 22a.
sent to. In the above, multiple copying of one sheet or double-sided copying has been described, but in the case of multiple copying of a plurality of sheets or double-sided copying, the intermediate tray portion 5 is used. As shown in FIG. 1, the intermediate tray portion 5 is provided with an intermediate tray 3o that temporarily stores the cut sheet SH on the conveyance path 31. As shown in FIG. In the case of this multiple copying of a plurality of sheets, the fixed cut sheet SH is partially ejected by the paper ejection roller 23 under the same control as in the case of double-sided copying of a single sheet copy, and then the paper ejection roller 23 is ejected. By driving in reverse, it is stored in the intermediate tray 30 via the conveyance path 22, flapper 32, and conveyance path 36. This operation is repeated, and after all of the first side is stored in the intermediate tray 30, the feeding roller 33 is driven in response to the next copy command, and copying of the second side is executed via the conveyance path 36. On the other hand, in the case of multiple double-sided copies, under the same control as in the case of single-sheet multiple copying described above, the paper passes from the fixing device 19 through the conveyance path 22, 36 by the flapper 21 and is stored in the intermediate tray 30. The subsequent operations are the same as in the multiple copy case described above.
The explanation here will be omitted. 25 is a scanner motor that rotates a polygon mirror (rotating polygon mirror) 25a at a predetermined speed, and rotates a semiconductor laser 26.
Deflects the laser beam emitted from the Note that the scanner motor 25. A digital scanning unit is configured from a semiconductor laser 26, etc., and emits a laser beam corresponding to the digital image information input from the image processing section of the controller section 2a, and combines the image obtained by the above-mentioned analog image recording and this digital image. In addition to recording the recording as a superimposed image, at the time of analog image recording, the latent image area recorded on the photosensitive drum 11 is irradiated with a laser beam to selectively erase the latent image. Reference numeral 27 denotes an exposure shutter, which blocks part or all of the reflected image light to prevent latent image formation. And 28 is a primary charger. Note that S1 to S15 in the figure. S19 to S23 are sensors, and in particular, sensor S1 detects the home position of the optical system serving as an analog scanning unit, and the optical system is stopped at this position during standby. Further, the sensor S2 detects that the optical system has moved to a position corresponding to the leading edge position of the original image, and controls the timing of the copy sequence using this sensor output. The sensor S3 is at the limiter position (inverted position) during maximum scanning. The optical system performs a reciprocating operation with a scan length according to the cassette size and magnification inputted via an operation section, which will be described later. FIG. 2 is a block diagram illustrating the configuration of the controller section 2a shown in FIG. 1, and the same parts as in FIG. 1 are given the same reference numerals. In the figure, 41 is the operation unit, which includes keys for setting the copy mode (single-sided, double-sided, multiplex, etc.) and copy mode (magnification, paper size, etc.), as well as all the documents fed from the automatic document feeder (ADF). The first mode setting key sets the first recording mode in which digital information stored in advance from the digital scanning unit is superimposed on the original document. A second mode setting key is arranged (details will be described later) for setting a second recording mode in which digital information stored in advance from the scanning unit is superimposed. 42 is a control unit (controller), and the CPU 42 a
, ROM 42b, RAM 42c, etc., and performs overall control of the copying sequence based on a control program stored in the ROM 42b. Reference numeral 43 denotes an editor, through which area designation for a predetermined area of the document is input. 44 is a shutter section, 1 exposure shutter 27
It consists of a solenoid and a solenoid. 45 is a laser section, which includes semiconductor lasers 26. It is composed of a skisana motor 25 and the like. Reference numeral 46 denotes an AC driver, which supplies AC power to an AC load 47 such as the document exposure lamp 20. 48 is a motor control section, and the solenoid 14a
, 14b, clutch. Controls the drive of fans, etc. 50a is a feeder control section that controls driving of the document feeding section. A sorter 50b discharges the cut sheets SH discharged by the drive of the paper discharge roller 23 into a designated paper discharge bin. The HVT is a high voltage unit that applies a voltage of a predetermined potential to the charging system and the developing sleeves of the developing units 13a and 13b. DCP is a DC power supply and supplies a control potential r+5VJ to the controller section 2a and the like. Description of Operation> Next, the operation of the image processing apparatus in the embodiment will be described below with reference to related drawings. First, when the power switch 2b is turned on, the heater in the fixing device 19 is energized by the controller section 2a, and waits (wait time) until the fixing roller reaches a predetermined temperature at which fixing is possible. When the fixing roller reaches a predetermined temperature, the main drive motor MM is driven for a certain period of time, and the photosensitive drum 11 and the fixing device 19 are driven to set the rollers in the fixing device 19 at a uniform temperature (weight release rotation). . Thereafter, the main drive motor MM is stopped, and the copying is possible (standby state). Here, the main drive motor MM is connected to the photosensitive drum 11. It drives the fixing device 19, the developing units 13a and 13b, and various transfer paper conveyance rollers. When a recopy command is input from the operation unit 41, a copy sequence is started. Here, when performing normal image recording, a latent image is formed on the drum 11 without using the optical filters 20d and 20e. At that time, the laser 26 can also irradiate a laser beam onto any preset area in the image to erase part of the image. Further, when the red color erasing mode is selected, the optical red filter 20d is set in the path of the reflected light from the original, and the red color is erased and an image is recorded. Similarly, in the case of fruit and vegetable color erasure, the optical blue filter 20e is used. First Example> Hereinafter, a first example in which red/black automatic color separation is performed will be described in the following order. (1), Black image latent image (2), Black image development (3), Red image latent image (4), Red image development (1), Black image latent image First, the black image drum 11 Figure 1 shows the latent image of . This will be explained with reference to FIG. In this case, as an operation before forming a latent image of a black image, in order to perform red separation, the optical red filter 20d is connected to the imaging lens 2d.
Set before. Here, by moving the original exposure lamp 2c and the scanning mirror in the direction of the arrow shown in FIG. will be held. The reflected light from the original 999 is reflected by the half mirror 20a.
is reflected by the optical red filter 20d, and is input to the original 9.
The red information within 99 is deleted. The reflected light from which the red information has been erased passes through the imaging lens 2d and forms an image on the drum 11. As a result, other information from which the red information of the document 999 has been removed is formed as a latent image on the drum 11. (2) Development of a black image Next, development of a black image will be explained with reference to FIGS. 1 and 3. As shown in FIG. 1, the cut sheet SH is
When the sheet is fed by the rollers a and 3b and fed into the image forming section 4, the latent image on the drum 11 excluding the red information is developed by the black developing unit 13a and transferred to this cut sheet SH. Ru. After the transfer is completed, the cut sheet SH is separated from the drum 11 by the separation charger 16. Further, the toner remaining on the drum 11 is removed from the cleaner device 1.
Recovered by 8. The cut sheet SH, which has been subjected to the nine development steps, is then conveyed to the fixing device 19, where the black toner image on the cut sheet SH is fixed by heat and pressure, and black information is recorded. Then, the recorded cut sheet SH is transferred to the flapper 21
The latent image of the red image,
Wait until development is performed. (3) Latent image of red image Next, FIG. 1 shows the latent image of the red image on the drum 11. This will be explained with reference to FIG. First, the shutter 27 shown in FIG. 1 is closed as a pre-operation for forming a latent image of a red image. By closing this shutter 27, optical information from the imaging lens 2d is blocked. Here, the original exposure lamp 2c and the scanning mirror are moved by the optical system drive motor (optical motor) 2f in the direction of the arrow shown in FIG.
99, and scanning of the original is performed. And manuscript 9
The reflected light from 99 passes through the half mirror 20a and forms an image on the CCD line sensor 20C by the lens 20b. Next, this CCD line sensor 20c will be explained below with reference to FIG. <Description of CCD line sensor (Figure 4)> As shown, the CCD line sensor 20c is composed of a line sensor P1 fitted with a red optical filter and a line sensor P2 fitted with a cyan optical filter. Ru. The charges accumulated in these two line sensors Pi and P2 for a predetermined period of time are transferred to the shift register P3゜P.
4 and shifted by the shift clock CLK. Here, P3 is output as an R signal, but as the arrow indicates the paper feed direction, the image is read one line earlier than the R signal, so the C signal is one line faster. The line buffer P5 absorbs the advance and outputs it in phase with the R signal. Next, the R signal and C signal from this CCD line sensor 20c are each input to the controller section 2a as analog electrical signals. Here, image processing within the controller section a will be described below with reference to the block diagram shown in FIG. As shown in the figure, the R signal and C signal from the CCD line sensor 20c are input to an amplifier 100R and an amplifier 100C. This amplifier 100R. 100C, when the CCD line sensor 20c reads a white plate (not shown) installed in the document scanning unit 2, the output from the amplifiers 100R, 100C becomes the full scale of the next stage A/D converter 11OR, 110C. In this way, the R signal and C signal are amplified. Next, the analog signals amplified by the amplifiers 100R and 100C are converted from analog to digital by the A/D converters 110R and 110C at the next stage to become 8-bit digital information. And A/D converter 1lOR, 110C
The output from the shading circuit 12OR, 120C
is input. Here, variations in sensitivity of the CCD line sensor 20c, unevenness in light amount of the document exposure lamp 2C, etc. are corrected. Outputs from the shudders 12OR and 120C are input to a look-up table (LUT) 140 and inverting circuits 130R and 130C, respectively. This LUT 140 contains the input red digital information 30.
0R (8 bits, 256 gradations) and front thread digital information 3
Color discrimination signal 310 from 00C (8 bits, 256 gradations)
It outputs A, 310B, and 310G, respectively. Color discrimination by this LUT 140 is shown in FIGS. 6 and 7. Figure 6 shows a red discrimination signal 310A and a black discrimination signal 310C.
Similarly, FIG. 7 is a table for creating a blue discrimination signal 310B and a black discrimination signal 310C. For example, the red light 300R is "200",
When the green signal 300C is "100", as shown in FIG. 6, this value is in the red area, so the red discrimination signal 31
0A becomes "1". Further, according to FIG. 7, since the area is other than blue, the blue discrimination signal 310B becomes "O". The LUT in Figure 6 is used for red-black discrimination in the case of red-black print, and the LUT in Figure 7 is used for blue-black discrimination in the case of blue-black print. is not limited to FIGS. 6 and 7. That is, for example, in FIG. 6, if the area that is determined to be red is enlarged, the range of hues that are determined to be red is also expanded. Therefore, depending on the user's preference, a plurality of tables with different boundaries may be selected even if they are for the same red/black discrimination. Note that the tables in FIGS. 6 and 7 are for the optical system filter 2.
The boundary is set to match the distribution range of color information that can be removed by 0C, but in general, the color distribution range of the color information of the front thread that can be removed by the front thread filter is narrower than that of the red filter. By configuring as shown in FIGS. 20 and 21, it is possible to match the distribution of color information that can be removed by the optical filter and the color information that is digitally extracted. That is, the area subjected to red discrimination in FIG. 21 is narrower than the area subjected to red discrimination in FIG. Next, the black discrimination signal 310C is input to the binarization circuit 200. Further, the red signal 300R and the fruit and vegetable signal 300C are inverted by inverting circuits 130R and 130G, respectively, and the signal 3
20B and 320A. Since this signal 320B is the inverted version of the red luminance signal 300R, it becomes a cyan density signal. Since the signal 320A is an inversion of the front yarn brightness signal 300C, it becomes a reddish density signal. The selectors 150 and 160 shown in FIG.
It is controlled by the 110 port (not shown) of U42a, and when performing red color separation, the control line is connected to “O”.
', and when color separation of the front thread is performed, the control line is set to "1". In other words, when red color separation is selected, the signal 330 has
Signal 310A is selected and signal 340 has signal 320A selected.
is selected. Below, when performing red color separation, that is, selector 1
The case where the control lines 50 and 160 are set to "O" will be described in detail. Red density signal 34 selected by the selector 150 described above
0 is input to the X terminal of the selector 170, and a fixed value (“32” in this embodiment) is input to the X terminal. Further, the red area signal 330 is the control terminal S of the selector 170.
For example, as shown in FIG.
If the signal input to is "1", the red density signal 340 is selected, and if it is "O", a fixed value is selected and output. Here, when the red area signal 330 is "O", the reason why a constant other than "O" is selected as the fixed value is based on the following reasons. That is, if the red density signal 340 is set to "0" when it is determined that it is not red, the signal 3 in FIG.
At 50, the concentration difference before and after time t is d2, which is larger than dl when a constant other than "O" is taken as the fixed value. Therefore, even if it is a gentle changing part that is not an edge part, the boundary before and after time t of the binarized data is emphasized due to the edge emphasis effect by the edge emphasis circuit 180, which will be described later, resulting in an unsightly image. becomes. Therefore, such a drawback is prevented by providing a positive constant other than "O" as a fixed value as described above. Note that the fixed value does not have to be "32" and may be changed depending on the red color processing and the front thread processing. Furthermore, the operator may be able to select from a plurality of fixed values in order to obtain the desired image quality. FIG. 22 shows a case where there is a red round image in a black image, and shows a red area signal 330 indicating a red area and contact information indicating a part where a red image and a black image are in contact. The control signal 380 input to the S terminal of the selector 170 is obtained by subtracting the contact point information from this red area signal 330. FIG. 23 shows how the display density information 340 is selected by the control signal 380 described above. If the red density information 340 is simply selected using the red area signal 330, black information will be mixed into the desired red area at the point where it changes from black to red due to the resolution of the COD. Therefore, in the embodiment, the control signal 38 of the selector 170 is
Create 0. In this way, it is possible to extract the signal 350 only in the desired red region. This contact information includes, for example, a red area signal from “O” to “1”.
” or from “1” to “O” can be extracted by providing a circuit between the selector 160 and the selector 170. Area signal 33
0 and, for example, the contact signal (
It is also possible to perform an AND operation with an inverted signal obtained by inverting the contact point information of the black discrimination signal 310C and the red discrimination signal 310A, and select the result as the control signal 330' (see FIG. 24). Next, the output signal 350 from the selector 170 is input to an edge enhancement circuit 180 and an averaging circuit 190. The edge emphasis circuit 180 is configured with a known edge emphasis filter and emphasizes the edge portion of the input signal 350, and the averaging circuit 190 uses the input signal 350 as a direct average of the pixel of interest in a 9×9 matrix. This is the circuit that performs the conversion. The signals 360 and 370 output from the edge emphasis circuit 180 and the averaging circuit 190 are sent to the next stage binarization circuit 2.
00 respectively. This binarization circuit 200 is
The 8-bit output signal 360 of the edge enhancement circuit 180 and the 8-bit output signal 370 of the averaging circuit 190 are compared, and 1
Outputs a bit red signal 380. Note that, of course, the size of the filter that performs edge enhancement and smoothing is not limited to the above example. In this way, since the edge-enhanced image is binarized using the average value as the threshold, it is possible to appropriately binarize an image with a pale yellow tone, for example, and it is also possible to properly binarize an image that tends to occur during binarization. Blurred edges can be prevented. Next, the red signal 380 binarized by the binarization circuit 200 is input to the next stage noise removal circuit 210, where noise removal is performed. This noise removal circuit 210 is shown in FIG.
) and (b), and converts isolated red information in white information to white information, and converts isolated white information in red information to red information. This is a circuit that removes noise. The output signal 390 from the noise removal circuit 210 is input to the expansion circuit 220 and the synthesis circuit 240. Here, the expansion circuit 220 has two functions: a contact extraction function that detects a portion where black information and red information are in contact, and an expansion function that expands this extracted contact point.
Black information 310C that passes through 00 and red information 390 from which noise has been removed are input. First, the contact extraction function will be explained below with reference to FIGS. 10(a) to (c). As shown in FIG. 10(a), this contact point extraction is composed of a 3×3 matrix, and if both red and black information are included in the four pixels around the pixel of interest, the contact information of the pixel of interest is If both red and black information are not included in the four pixels around the pixel of interest as shown in FIG. 10(b), the contact point information is set to "O". FIG. 10(c) is a diagram showing contact point information when red and black images intersect. Next, the expansion function, which is the second function of the expansion circuit, will be explained with reference to FIG. First, FIG. 11(a) is a diagram showing a basic matrix for expansion. As shown in the figure, the basic matrix is composed of a size of 9×9, and contact information is contained in the matrix excluding the pixel of interest. If so, set the pixel of interest to “1”,
Also, if there is no contact information, it is set to "O". Next, the first
FIG. 1(b) is a diagram in which two pieces of contact information A and B are expanded using the matrix of FIG. 11(a). In the figure, expansion information A is a diagram expanded from contact information A, and is indicated by a two-dot broken line. Expansion information B is a diagram expanded from contact information B, and is indicated by a dotted line. The size of the matrix to be expanded is not limited to the above-mentioned 9×9. Next, the expansion information A and B pass through the signal line 400,
It is input to compression circuit 230. Like the expansion circuit 220, this compression circuit 230 also has a 9×9 matrix (FIG. 11(a)), and if all of the matrix except the pixel of interest is expansion information, the pixel of interest is The size of the matrix to be compressed may be adjusted to the expansion rate, or may be smaller or larger than the expansion rate. this"
1'' is output as compressed information to the signal line 410, input to the synthesis circuit 240, and then the noise removal circuit 2.
signal 390 from 10. Here, the operation of this synthesis circuit 240 will be explained with reference to FIG. 13. As shown, the synthesis circuit 240 separates the red information signal 39 from the intersections of the red and black images, respectively.
0 and the compressed information signal 410 from the compression circuit 230 are combined and output as a combined signal 420. That is, by combining the compressed information signal 410 with the red information signal 390, it becomes possible to interpolate the missing red information caused by the intersection of red and black. Therefore, even if the position of the black latent image formed by the analog system and the position of the red latent image formed by the digital system deviate due to mechanical precision, the formed image will not look good. This eliminates the possibility of creating an image that is close to the original. Next, the output signal 420 from the above-mentioned combining circuit 240 is input to the next scaling circuit 250, where a predetermined scaling process is performed according to an instruction from the operation section 41. The output signal 430 of this variable magnification circuit 250 is input to the next stage laser driver circuit 260 and is processed here to drive the laser 26. Laser 26 converts electrical signal 44 from laser driver circuit 260 into optical information;
The optical information is reflected by the rotating polygon mirror 25a, and the drum 11
Latent image of red information on the surface. (4) Developing the red image Through the above processing, the latent red image is developed as shown in Figure 1.
This will be explained below with reference to FIG. The red information formed as a latent image on the surface of the drum 11 by the laser 26 described above is developed by the red developing unit 13b. Here, the cut sheet SH, which has undergone black development and has been conveyed to the registration rollers 12, is conveyed at the same time as the development starts, and a red toner image is transferred onto the surface of the drum 11. When this transfer is completed, the toner is separated from the drum 11 by the separation charger 16 and then conveyed to the fixing device 19. The red toner image on the cut sheet SH is fixed by this fixing device 19 using heat and pressure. Here, the cut sheet SH on which black and red information is recorded is
The paper is discharged onto the paper discharge tray 24 by the flapper 21 . FIG. 17 is a flowchart illustrating an example of an image synthesis processing procedure in the apparatus according to the present invention. Delete the red analog image in original 999 (original 9
99), an optical filter 20d is set in front of the imaging lens 2d (step 510). Next, the original 999 is illuminated by the original illumination lamp 2c and the scanning mirror, and the reflected light is guided to the optical filter 20d, where only the red image information in the original 999 is erased and the remaining image information passes through the imaging lens 2d. A latent image corresponding to the image excluding the red image is formed on the photosensitive drum 11 (step 511), and the latent image excluding the red image is developed into black in the developing unit 13a (step 512).
). Next, the developed black image is transferred to a cut sheet SH that is transported based on a known electrophotographic process, and after the transfer, the cut sheet SH is separated by a separation charger 16, and then the toner image is heated by a fixing device 19. It is pressed and fixed. In this way, the cut sheet SH on which the black image information has been recorded is controlled in both directions by the flapper 21, and is transferred to the conveyance paths 22 and 22 forming multiple passes for the next image recording.
a, and is conveyed to the position where the registration rollers 12 are provided. Here, an exposure shutter 2 is placed in front of the photosensitive drum 11 in preparation for the next red image recording (digital image recording).
7 (step 513). As a result, the optical information from the imaging lens 2d is no longer imaged onto the photosensitive drum ll. Next, the original 999 is illuminated by the original illumination lamp 2C and the scanning mirror, and the reflected light passes through the half mirror 20a.
An image is formed on the line sensor 2Oc and read (step 514).The electric signal thus photoelectrically converted by the line sensor 20c enters the controller 2a, and is separated into red (step 515). The red image information is applied as red recording information to the laser driver 260, and the semiconductor laser 2 constituting the digital image recording type
6 is modulated and driven to be scanned by the polygon mirror 25a to form a red latent image on the photosensitive drum 11 (step 516). Next, after being developed in red by the developing unit 13a (step 517), it is transferred onto the re-fed cut sheet SH. The cut sheet SH after the transfer is separated by a separation charger 16 and fixed by a fixing device 19. In this way, the cut sheet SH on which the black and red image information has been recorded in a composite manner is discharged by the flapper 21 to the paper discharge tray 24, and the process is completed. Note that if it is possible to select a filter color for color separation according to the developed color set in the developing unit 13a, an image corresponding to the developed color can be combined and recorded as a digital image with an analog image. In other words, in addition to two-color printing of black and red, two-color printing of black and blue can also be performed in the same way.
It is also possible to perform multi-color printing using three colors of blue or additionally a developed color. As explained above, according to the first embodiment, by performing multiple development, it is possible to copy in two colors, red and black. Second Embodiment> The second embodiment will be described in detail below with reference to the related drawings. Note that FIG. 18 is a diagram showing an image processing block in the second embodiment. Processes similar to those in the first embodiment described above are given the same reference numerals, and here, the lookup processing described above is The color extraction calculation circuit 140a corresponding to the table 140 will be explained. The color extraction calculation circuit 140a is LUT 1 of the first embodiment.
It performs the same function as 40, and input signals 300R, 3
Red discrimination signal 310A, blue discrimination signal 310 for 00C
B, a black discrimination signal 310C is output. The processing performed by this color extraction calculation circuit 140a will be described next. FIG. 19 shows a color extraction calculation circuit 140 for extracting a reddish image.
This is a flowchart showing the calculation of a, and will be explained according to this flowchart. Red that can be removed by the optical red filter 20d. In order to obtain a color distribution range approximately equal to the color distribution range of fruits and vegetables (Fig. 20 and Fig. 21), first, in step S20,
Equation 0 is calculated from the 256-level red digital signal 300R and the front thread digital signal 300R. 300R-300C≧32...■ If the result is YES, the pixel is determined to be red in step S21, and "1" is output to 310A. However, no
If so, in step S22, 300R and 300C
If both are less than "160", the pixel is set as a black image in step S23, and "l" is output to 310C. Also,
If the above conditions are not met, in step S24
The equation is calculated, and if YES, "l" is output to 310B as a blue image in step S25. 300R-300C≦-48...■ However, if NO, the image is regarded as a white image (other than an image) in step S26, and 310A is performed. 310B and 310C are each "O". Thereafter, by switching the selector 160, the color distribution shown in FIG. 20 is obtained when extracting reddish colors, and the color distribution shown in FIG. 21 is obtained when extracting front thread colors, and the colors removed by the optical filter are obtained. An approximation to the distribution range of can be obtained by calculation. As described above, according to the second embodiment, by matching the removal color distribution range of a predetermined color with the extraction color distribution range, a high-quality image without double images or image loss can be obtained. [Other Embodiments] Next, other embodiments according to the present invention will be described in detail with reference to the related drawings. In this embodiment, the processing from the shading circuits 12OR, 120C to the laser driver 260 of the image processing block shown in FIG. A reference numeral is given and the explanation here is omitted. Furthermore, the latent image and development of the black image are similar to those in the above-described embodiment, and the latent image formed on the drum 11 of the red image will be explained. First, the shutter 27 shown in FIG. 1 is closed as a pre-operation for forming a latent red 0 image. By closing this shutter 27, optical information from the imaging lens 2d is blocked. Here, by moving the original exposure lamp 2c and the scanning mirror in the direction of the arrow shown in FIG.
99, and scanning of the original is performed. And manuscript 9
The reflected light from 99 passes through the half mirror 20a and forms an image on the CCD line sensor 20C by the lens 20b. Next, the R signal and C signal from the CCD line sensor 20c are input to the controller 2a as analog signals. Here, the image processing in the controller section a is carried out in the 14th mode.
This will be explained below with reference to the block diagram shown in the figure. As shown in the figure, the R signal and C signal from the CCD line sensor 20c are input to an amplifier 100R and an amplifier 100C. This amplifier 100R. 100C, when the CCD line sensor 20c reads a white plate (not shown) installed in the document scanning unit 2, the output from the amplifiers 100R, 100C becomes the full scale of the next stage A/D converter 11OR, 110C. Thus, the R signal and C signal are amplified. Next, the analog signals amplified by the amplifiers 100R and 100C are converted from analog to digital by the A/D converters 110R and 110C at the next stage to become 8-bit digital information. And A/D converter 1lOR, 110C
The output from the shading circuit 12OR, 120C
is input. Here, variations in sensitivity of the CCD line sensor 20c, unevenness in light amount of the document exposure lamp 2c, etc. are corrected. The output signals 300R, 300C from the shooting 12OR, 120C are sent to the memories 28OR, 120C, respectively.
280C. The memories 28OR, 280C in this embodiment have 8 pixels per pixel.
It has a bit depth of "rAB size", that is, a capacity that can store 8 bits for all pixels of one screen. The above-mentioned signals 300R and 300C are sent to the memories 280R and 280C in a hardware manner by the timing control unit 270.
It is stored in C. Next, for the image data in memories 28OR and 280C,
Each process performed by the CPU 290 via the CPU bus will be described below. In this embodiment, two colors, red and black, are separated. First, color separation will be explained according to the flowchart shown in FIG. The same pixel position (x, y
) is Rxy+cxy, the color separation of the red information is determined to be a red image if the formula (2) holds (YES in step S1). However, O≧RXy+C”≦255. Rxy Cxy≧32...
■Let this image determined to be a red image be A fly, and A x
y is found from equation 0 (step S2). A, .ltoreq.255-C, . . .■ In addition, if the image satisfies the formula (2) for an image other than a red image, it is determined that the image is a black image (YES in step S3). Clly≦100...■
Then, let the image determined to be a black image be Kmy (step S4), and the case where it is neither red nor black be A, ,=O
(Step S5). Next, edge enhancement is performed on the red image A xy described above. This edge enhancement is performed using a 9x9
Calculation is performed using the filter. Here, if E xy is an edge-enhanced image, and α (≧O) is a coefficient representing the edge strength, E Xl+ can be found from equation (2). Ely ”Axy+α(4AXY-A +X-41y
-A +1441 V-AX +y-4-Ax (y◆
4)) ・・・■Again. Averaging processing is performed on the red image A xy described above. In this averaging process, the same calculation as in the first embodiment is performed for the 9×9 area. Here, if the averaged image is Sxy, it can be found by calculating the equation (2). Then, a binarization operation is performed from the previously obtained edge image Exy and the averaged image SxF. Letting the result of this binarization operation be B, then E, ,>S
In the case of +111, set B, , = 1, and E xy≦S K
In the case of V, the red image is binarized by setting Bxy to 20. Next, noise removal is performed using the 3 steps shown in FIGS. 9(a) and (b).
It is composed of X3 filters and performs two types of noise removal. First, as shown in FIG. 9(a), when the target pixel B As shown in Figure 9(b), when the target pixel B xy is "O" and all eight surrounding pixels are "1", that is, a red image, B , two processes are performed: one is a contact extraction process that detects the part where black information and red information touch, and the other is an expansion process that expands the extracted contact points.The contact extraction process is as follows. As shown in FIG. 10(a), when red image information (B, , = 1) and black image information (K, , = 1) are included in a 3x3 matrix centered on the pixel of interest, The contact point images T, y are set to "1". Next, another dilation process is a process of dilating the previously obtained T If there is a contact image T This is shown by a dotted line and a double dotted line. The compression process in this example is a process for compressing the expanded image U xy obtained by the expansion process. This compression process uses a 9x9 matrix and is shown in FIG. When all 800 pixels surrounding the pixel of interest are the expanded image Uzy, the image of interest is set to "l", and this is compressed to a compressed image (shaded area). The processing is a compressed image D my obtained by compression processing.
This is a process of synthesizing the red image B xy obtained by noise removal, and the result is the first
It can be expressed as shown in Figure 3. Next, the scaling process is a process of scaling the composite information performed in the above-described compositing process according to the scaling factor instructed from the operation unit 41. The CPU 290 executes each of the processes described above, and stores the results of the above-mentioned scaling process in the bitmap memory 280X in FIG.
to be memorized. Information stored in bitmap memory 280X is read by timing control 270 and input to laser driver 260 through signal line 430. Here, the laser driver 260 performs processing for causing the laser 26 to emit light. The laser 26 then converts the electrical signal 44 from the laser driver 260 into optical information,
By reflecting the optical information onto the rotating polygon mirror 25a, a latent image of red information is formed on the surface of the drum 11. Note that the development of the red image is the same as in the example described above.
The explanation here will be omitted. As described above, by having the CPU 290 perform various processes on the latent image of a red image, it is possible to copy two colors, red and black, with a simple configuration. In the above-described embodiment, a case has been described in which a latent image of a digital image is formed on the photosensitive drum 11 by the semiconductor laser 26 constituting the digital image recording system. It is also possible to have a configuration in which a digital image is recorded by configuring an array or the like. This also allows the configuration of the digital image recording system to be downsized. Further, the LED may be of a type that performs exposure by bringing it into close contact with the photoreceptor drum. In addition, in the above-described embodiment, in the color separation process in the image processing means, the color separation filter executes the red and blue discrimination process based on the output from the line sensor 20C of two filters, red and cyan. R
The determination may be made by multiplying the ratio of the data C and the cyan data C by a constant k, and comparing that value with the slice levels Sr and Sb. Furthermore, the digital recording system described above has a function of erasing the latent image when exposing an area where an analog latent image has already been formed, and a function of erasing the latent image when exposing an area where no latent image has been formed. has add-on functionality. Note that the digital color separation process may be performed by software in the controller unit as described above, or may be implemented by hardware using an LUT or the like. Further, although a two-line CCD sensor is used as the above-mentioned reading means, a mosaic type sensor in which pixels are alternately arranged in the order of RCRC, . . . , may also be used. In addition to the electrophotographic color printer described above, the present invention can also be applied to a so-called Cycolor one-type color printer. In other words, it is not limited to the type that forms a latent image on a photoreceptor;
The recording medium may be of a type in which special paper is directly exposed to light. In this way, a color image with a certain tone contained in an original image can be simply binarized and recorded as a binary image by combining it with an analog image, which is cheaper than combining it as a multivalued image. It can be composed of In addition, digital image recording system, original stamp function, add-on function,
Combination with the framing function and blanking function enables a wide variety of image composition processing. Margin below [Effects of the Invention] As described above, according to the present invention, it is possible to form an image by binarizing only desired color information in a color image.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram showing the configuration of an image forming apparatus in an embodiment. FIG. 2 is a block diagram showing the configuration of the controller section in FIG. 1. FIG. 3 is a diagram explaining document scanning. A diagram showing the configuration of a CCD line sensor, FIG. 5 is a block diagram showing image processing in the first embodiment, FIGS. 6 and 7 are diagrams showing color discrimination in the first embodiment, and FIG. Figure 9 is a diagram illustrating the selection of concentration signals, Figure 9 is a diagram illustrating noise removal in the example, Figure 10 is a diagram illustrating contact extraction in the example, and Figure 11 (a) is the diagram illustrating expansion in the example. A diagram showing the matrix, FIG. 11(b) is a diagram showing the relationship between contact information and expansion information in the example, FIG. 12 is a diagram showing expansion/compression in the example, and FIG. 13 is a diagram showing the relationship between contact information and expansion information in the example. FIG. 14 is a block diagram showing image processing in another embodiment; FIG. 15 is a flowchart showing color separation processing in another embodiment; FIG. 16 is a block diagram showing image processing in another embodiment. FIG. 17 is a flowchart showing image synthesis in the embodiment; FIG. 18 is a block diagram showing image processing in the second embodiment; FIG. 19 is a diagram showing the image processing in the second embodiment. FIGS. 20 and 21 are diagrams showing color discrimination in the second embodiment, and FIGS. 22 to 24 are diagrams explaining contact extraction. In the figure, 1... Copying apparatus main body, 2... Original scanning section, 2
a...Controller unit, 3...Paper feeding unit, 4...Image forming unit, 5...Intermediate tray part, 41...Operation unit,
42... Controller, 42 a-CPU, 42
b・ROM, 42c...RAM, 43...editor, 44...shutter section, 45...laser section, 4
8...Motor control unit, 13a, 13b...Developing unit, 20 C-CCD line sensor, 140...L
UT, 150-170...Selector, 180...Edge emphasizing circuit, 190...Averaging circuit, 200...
Binarization circuit, 210... Noise removal circuit, 220...
- Expansion circuit, 230... compression circuit, 240... synthesis circuit, 250... variable magnification circuit, 260... laser driver. Figure 2 100 00 55 t14! U00R Fig. 9 (0) Fig. (b) Fig. 11 (0) Fig. 11 (b) Fig. 12 Fig. 15 Fig. 16 Fig. 4F Fig. 19 t, Yogon Takumi 300R Fig. 20 G Pre-flight 300R Figure 21 Figure 22

Claims (1)

[Scope of Claims] Image input means for inputting a color image; color separation means for separating the color image from the image input means into color information of two or more colors; and a desired color information separated by the color separation means. An image forming apparatus comprising: a binarizing means for binarizing color information; and an image forming means for forming an image according to the color information in the binarizing means.