JP2651268B2 - Electrophotographic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrophotographic apparatus having a so-called marker editing copy function for editing and copying an image inside and outside an area designated by a mark written on a document. It is about.

[Conventional technology]

A conventional copying machine as an electrophotographic apparatus reads a color mark other than black on a manuscript and, for example, masks the image by erasing and copying only an image in an area indicated by the color mark, or a mask other than an area indicated by the color mark. There is known an image processing apparatus having a marker editing and copying function such as trimming for erasing and copying an image in an area.

In such a copying machine, when performing copying in the marker editing mode with the color mark set to red, first, reflected light from the original is read by image information reading means such as a CCD (Charge Coupled Device) to obtain image information. Can be Next, the presence or absence of a red color mark is determined from the image information by a marking determination circuit, and an area indicated by the color mark is set as an editing area.

In the above-described marking determination circuit, as shown in FIG. 5, the read output (image information) of the CCD is separated into R (red), G (green), and B (blue) color components by an RGB separation circuit 80. Are held at the sample and hold circuits 81 to 83, respectively. The held output of the sample and hold circuit 81 is input to the non-inverting input terminal of the comparator 85 via the amplifier 84. The outputs of the sample and hold circuits 82 and 83 are
Are added to form a G + B signal, which is input to the inverting input terminal of the comparator 85 via the amplifier 87. The held outputs of the sample hold circuits 81, 82, and 83 are added by an adder 88 to become R + G + B signals, and are input to an inverting input terminal of a comparator 90 and a non-inverting input terminal of a comparator 91 via an amplifier 89. The non-inverting input terminal of the comparator 90 and the inverting input terminal of the comparator 91 respectively have an upper limit value V of the luminance level of the light image of the document read by the CCD.
_max and the lower limit value V _min are input.

In the comparator 85, the R input to the non-inverting input terminal
The signal and the G + B signal input to the inverting input terminal are compared in level. When the level of the R signal is high by this comparison, the output of the comparator 85 becomes high level,
The color mark is identified as red. Meanwhile, the amplifier
R + G + B signal subjected to 89, if the range signal between the upper limit value V _max and the lower limit value V _min, the output of the comparator 90, 91 are both at a high level, the output of the AND circuit 92 becomes high level. Thus, it is determined that the density of the color mark is within a predetermined range. And the comparator 85
When the output of the AND circuit 92 is at a high level, the output of the AND circuit 93 is at a high level, and the presence of the red color mark is determined.

Then, the area indicated by the color mark determined as described above is set as the editing area, and the blank lamp is controlled according to the selected marker editing mode,
A copied image on which editing such as masking and trimming has been performed is obtained.

[Problems to be solved by the invention]

However, in the above-described conventional copier, the RGB, R, and B component ratios in the read output of the CCD may be different irrespective of the pixels of the same color due to variations in the characteristics of the elements constituting the CCD. For this reason, in the above-described marking determination circuit, the comparison levels of the comparators 85, 90, and 91 may vary depending on the pixel, and the determination of the presence or absence of a color mark may not be performed accurately.

[Means for solving the problem]

An electrophotographic apparatus according to the present invention, for solving the above-described problems, includes, for example, a CCD, and reads image information of a document from reflected light of light applied to the document, and reads image information of the document by image information reading means. From the read image information,
A color mark determination unit that determines whether or not there is a color mark indicating an editing area in the original image, and includes a marker editing / copying mode selected and an editing area designated according to the presence or absence of the color mark. Based on the control of the operation of the image editing means such as a blank lamp,
In an electrophotographic apparatus adapted to edit a copied image, the following measures are taken.

That is, the electrophotographic apparatus is provided with a white member that is irradiated with light to read image information by the image information reading unit and provides image information equivalent to that of a white original, while the color mark determination unit includes the image member in advance. Based on the image information obtained from the white member by the information reading means,
An image information correcting means is provided for correcting the color component ratio of the image information obtained when the image information reading means reads a white original so as to be constant regardless of the pixels of the white original.

The image information correcting means includes, for example, an AGC (Automatic Gain) based on image information obtained from a white member.
Control) A control voltage to be applied to the circuit is obtained for each pixel of the image information, and the gain of the AGC circuit is controlled by the control voltage, so that the image information of the white document is corrected by the AGC circuit. Can be

(Operation)

In the above configuration, at the time of marker editing and copying, the image information correction means in the color mark determination means converts the image information of the white original into pixels based on the image information obtained in advance from the white member by the image information reading means. Correct so that it is constant regardless of As described above, since the image information of the image information reading unit is corrected based on the white color, the image information when the pixels of the same color are read by the image information reading unit have the same color component ratio. Therefore, when pixels of different colors are read, the correspondence between the color of the pixels and the ratio of the color components of the image information becomes clear, and the color can be determined more accurately.

Therefore, the image information is not affected by the variation in the characteristics of each element of the CCD mainly used as the image information reading means, and the presence / absence of the color mark is accurately determined by the color mark determination means.

〔Example〕

One embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 2, a copying machine as an electrophotographic apparatus according to the present invention is provided with an optical system 1 at an upper portion. The optical system includes a copy lamp 2, mirrors 3 to 5, a mirror motor 6 for driving the mirrors 4.5 integrally, a lens unit 8, a lens motor 9 for driving the lens unit 8, a mirror 10 11, a mirror motor 12 that integrally drives the mirrors 10, 11, a filter 13, and a mirror 14. The optical system 1 performs optical scanning on a document (not shown) arranged on a document table 15 provided on the upper end surface of the copying machine.
The light reflected from the document is guided to a photosensitive drum 16 described later.

On the light incident side of the lens unit 8, there is provided a CCD unit 7 as image information reading means. The CCD unit 7 receives the reflected light from the document and converts it into image signal output into an electric signal read output. Then, the output is output to a blank lamp control unit 50 described later. The document table 15 has an optical system 1 in an area not involved in optical scanning of the document.
A white plate 40 as a white member is provided at a position where optical scanning is possible.

A photosensitive drum 16 is provided below the optical system 1. Around the photosensitive drum 16, a main charger unit 17, a blank lamp 18, a color developing unit 19, a main developing unit 20, a main developing unit toner box 21, a transfer charger 22, and a peeling charger 23 , A peeling claw 24, and a cleaner unit 25.

The main charger unit 17 charges the surface of the photosensitive drum 16 to a predetermined potential, while the blank lamp 18
Has a function as an image editing means, which removes electricity from a non-image area on the photosensitive drum 16. The color developing unit 19 is a developing device for performing color copying according to the marker editing mode, and the main developing unit 20 is a developing device for performing normal copying. The black toner provided to the main developing unit 20 is
The toner is supplied from the toner box 21 for the main developing unit. The transfer charger 22 transfers a toner image formed on the surface of the photosensitive drum 16 to a sheet supplied from a sheet feed cassette 27 via a registration roller 26. The transfer charger 22 includes a separation charger 23 and a separation claw 24. Is
The sheet is peeled from the photosensitive drum 16.
The cleaner unit 25 collects residual toner on the surface of the photosensitive drum 16.

A suction unit 29 having a suction belt 28, an upper heat roller 31 having a heater lamp 30, and a lower heat roller 32
, An upper peeling claw 33, a lower peeling claw 34, and a paper discharge roller 35, and a paper discharge unit 36 is opened near the paper discharge roller 35. Above the suction unit 29, a main motor 37 serving as a power source of each drive system is provided.
Above 35, a cooling fan motor 38 and an ozone absorption filter 39 are provided.

The control system of this copier has I / O
A main controller 44 composed of an interface 41, a memory 42 and a CPU 43, a CCD drive circuit 45, a marking determination circuit 46, a blank lamp drive circuit 47, and a CPU 4
8 and a blank lamp control unit 50 composed of a memory 49.

I / O interface 4 in main control section 44
1 includes a drive system 51 including a main motor 37 and the like, a main charger unit 17, a color developing unit 19, a main developing unit 20, a transfer charger 22, and a peeling charger 23.
Process system 52 including a cleaning unit 25 and the like
And a paper feed and feed roller
The transport system 53, the fixing unit 54 including the heater lamp 30, the upper heat roller 31, the lower heat roller 32, and the like, the operation panel 55 for inputting and displaying a marker editing mode and the like, and the optical system 1 are connected. . The CPU 43 controls the operation of each system connected to the I / O interface 41 according to the control program stored in the memory 42, based on the input from the operation keys of the operation panel 55, and in particular, prior to copying, The driving of the optical system 1 is controlled so as to optically scan the white plate 40.

Meanwhile, the CCD in the blank lamp control unit 50
The optical system 1 and the CCD unit 7 are connected to the drive circuit 45, the CCD unit 7 is connected to the marking determination circuit 46, and the blank clamp 18 is connected to the blank lamp drive circuit 47. The CCD drive circuit 45, the marking determination circuit 46, and the blank lamp drive circuit 47 are all connected to the CPU 48, and the CPU 48 is connected to the CPU 43 of the main control unit 44 and the memory 49.

The CPU 48 controls the operation of the CCD drive circuit 45 so that the CCD unit 7 reads image information from the original image in accordance with the operation of the optical system 1, and based on determination data output from the marking determination circuit 46, which will be described later. By specifying an editing area and controlling the blank lamp driving circuit 47 based on the editing area and the marker editing / copying mode selected by input to the operation panel 55, the blank lamp 18 is controlled.
Is controlled. That is, CPU48
For example, when the trimming mode is selected as the marker editing copy mode, the area specified by the color mark determined by the marking determination circuit 46 is set as a trimming area, and the image information of the trimming area is stored in the memory 49. At the same time, blank lamp data for not copying an image outside the trimming area is calculated, and the blank lamp data is output to the blank lamp driving circuit 47.

The CCD drive circuit 45 drives the CCD unit 7 based on a command from the CPU 48, and the blank lamp drive circuit 47 drives the blank lamp 18 based on the blank lamp data sent from the CPU 48. . A marking determination circuit 46 as a color mark determination means determines the presence or absence of a color mark of a designated color from the read output of the CCD unit 7, and sends the determination result to the CPU 48.

The marking determination circuit 46, as shown in FIG.
RGB separation circuit 56, AGC circuits 57 to 59, sample and hold circuit
60-62, adder 63-64, amplifier 65-67, comparator 68
To 70, AND circuits 71 and 72, A / D converter (A / D in the figure) 73
And a RAM 74.

The RGB separation circuit 56 is a circuit for separating the read output from the CCD unit 7 into R (red), G (green), and B (blue) color components. The AGC circuits 57 to 59 convert the R, G, and B component signals output from the RGB separation circuit 56 into the CPU 48
By controlling the gain using a later-described correction value calculated and output via the RAM 74 as a control voltage, the level of the read output of the white original is corrected so that the ratio of each component is constant regardless of the pixel. It has become. The sample hold circuits 60 to 62 are circuits that hold the levels of the outputs of the AGC circuits 57 to 69. The adder 63 adds the held outputs of the sample / hold circuits 61 and 62, and the adder 64 adds the held outputs of the sample / hold circuits 60, 61 and 62. The amplifier 65 amplifies the held output of the sample and hold circuit 60, while the amplifiers 67 and 68
・ Amplifies 64 outputs.

The comparator 68 compares the output of the amplifier 65 input to the non-inverting input terminal with the output of the amplifier 66 input to the inverting input terminal, and sets the output to a high level when the output of the amplifier 65 is large. It has become. comparator
69, inverts the output of the amplifier 67 is input to the input terminal, compares the upper limit value V _max of the luminance level of the light image of the original is input to the non-inverting input terminal, an output when the output of the amplifier 67 is smaller Is set to a high level. comparator
70 is the output of the amplifier 67 input to the non-inverting input terminal,
A comparison is made with the lower limit value _Vmin of the luminance level of the light image of the document input to the non-inverting input terminal, and when the output of the amplifier 67 is large, the output is set to the high level. AND circuit
Reference numeral 71 denotes a circuit that takes a logical product of the outputs of the comparators 69 and 70, and an AND circuit 72 is a circuit that takes a logical product of the output of the comparator 68 and the output of the AND circuit 71.

The A / D converter 73 is a circuit that converts the read output of the CCD unit 7 into digital image data. RAM74 is A
The image data from the / D converter 73 is temporarily stored and sent to the CPU 48, and the correction data calculated by the CPU 48 is temporarily stored, and this correction data is sent to the AGC circuits 57 to 59 at an appropriate timing at the time of marker editing and copying. It has become. When supplied from the RAM 74 to the AGC circuits 57 to 59, the correction data is converted into an analog correction value (not shown). On the other hand, the CPU 48 calculates the correction data based on the image data supplied through the RAM 74.
The ratio is calculated as a ratio of the read output to a constant value for each pixel of the document image. In addition, prior to copying, the CPU 48 obtains a correction value based on the read output obtained from the white plate 40 by the CCD unit 7 in conjunction with the operations of the optical system 1 and the CCD unit 7.

As described above, in the above-described marking determination circuit 46, the AGC circuits 57 to 59, the A / D converter 73, and the RAM 74 constitute the image information correction means 75.

In the above configuration, a general copying operation in the copying machine will be described.

At the time of the copying operation, first, the document placed on the document table 15 is scanned by the light emitted from the copy lamp 2 of the optical system 1. On the other hand, the surface of the photosensitive drum 16 is charged to a predetermined potential by the main charger unit 17 and then, if necessary, is discharged by a blank lamp 18 that operates based on blank lamp data to form a non-image area. The light reflected from the original is irradiated on the photosensitive drum 16 via the mirrors 3 to 5, the lens unit 8, the mirrors 10 and 11, the filter 13, and the mirror 14. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 16, and this electrostatic latent image is developed by the color developing unit 19 or the main developing unit 20 to become a toner image. This toner image is stored in the paper cassette 27
The sheet to which the toner image has been transferred by the transfer charger 22 to the sheet supplied from the printer is separated from the surface of the photosensitive drum 16 by the separation charger 23. afterwards,
The toner image on the paper is thermally fixed on the paper by the upper heat roller 31 and the lower heat roller 32, and the paper on which the toner image is fixed is discharged from the paper discharge unit 36 to the outside.

Next, the correction operation performed by the marking determination circuit 46 will be described.

First, when the main power of the copier is turned on, the optical system 1 is driven by a command of the CPU 43 in the main control unit 44,
Optical scanning is performed on the white plate 40. The reflected light from the white plate 40 is received by the CCD unit 7, converted into an electric signal for each pixel corresponding to each element of the CCD unit 7, and becomes a read output. This read output is, as shown in FIG.
-The ratio of the color components of GB is 3 from the first of the CCD unit 7.
The twentieth element is different for each pixel corresponding to each element due to the influence of the variation in the characteristics of each element.

The read output is supplied to a marking determination circuit 46,
After being converted into image data by the A / D converter 73, the image data is sent to the CPU 48 via the RAM 74. In CPU48, CCD unit 7
For example, correction data K _Rn , K _Gn, and K _Bn are calculated for each of the color components as shown in the following equation for the read output of the pixel, and the correction data is temporarily stored in the RAM 74.

Here, V indicates a constant voltage level, and V _Rn
V _Gn and V _Bn indicate the voltage level of each color component output by the n-th element of the CCD unit 7.

Next, when copying is started with the original placed on the platen 15, the reflected light from the original that has entered the CCD unit 7 is the CCD.
The data is read by the unit 7 and converted into a read output. Then, this read output is sent to the blank lamp control
The signal is input to a marking determination circuit 46 in 50.

In the marking determination circuit 46, the read output is separated into RGB components by an RGB separation circuit 56. At this time, for example, the R signal is, as shown in FIG.
The voltage level differs for each element of the D unit 7, that is, for each pixel of the document. The correction data K _Rn , K _Gn, and K _Bn calculated in advance by the CPU 48 and stored in the RAM 74 before copying as described above are used as analog correction values by the AGC circuit 57.
To 59, and the signals output from the RGB separation circuit 56 are corrected with this correction value so as to have a constant level. As a result, when a white portion (white document) of the document is read, for example, the R signal is all set to 2V as shown in FIG. 4 (c) by the correction value obtained as described above. Can be aligned.

The level of the signal whose level has been corrected by the AGC circuits 57 to 59 is held by the sample and hold circuits 60 to 62. The held output of the sample / hold circuit 60 is input to a comparator 68 via an amplifier 65, and the held outputs of the sample / hold circuits 61 and 62 are added by an adder 63 to form a G + B signal. Comparator 68
Is input to In the comparator 68, the two held outputs are compared in level. When copying is performed in the marker editing mode by specifying a red color mark, the R signal at the pixel corresponding to the color mark is larger than the G + B signal. The output of the comparator 68 becomes high level, and the red color mark is recognized.

Further, the held outputs of the sample hold circuits 60, 61, and 62 are added by an adder 64 to form an R + G + B signal.
The signal is input to the comparators 69 and 70 via the amplifier 67. In the comparators 69 and 70, the R + G + B signal is a predetermined upper limit value.
Whether in the range between V _max and the lower limit value V _min is determined. In this determination, when the R + G + B signal is within the above range, the outputs of the comparators 69 and 70 are both at the high level, and the output of the AND circuit 71 is at the high level. Accordingly, it is determined that the density of the red color mark is within a predetermined range. When the output of the comparator 68 and the output of the AND circuit 71 are both at the high level, the output of the AND circuit 72 is at the high level, so that it is determined that there is a red color mark, and this determination result is sent to the CPU 48 as the determination data. You.

The CPU 48 calculates blank lamp data of an area to be erased at the time of copying based on the command sent from the CPU 43 of the main control unit 44 in accordance with the marker editing mode input from the operation panel 55 and the above determination data. You. In the blank lamp driving circuit 47, the blank lamp 18 is operated based on the blank lamp data, and a portion on the surface of the photosensitive pair drum 16 corresponding to the area of the original to be erased is discharged. Therefore, an electrostatic latent image is not formed on this portion, and an image corresponding to a desired marker editing mode is obtained on the sheet on which the developed toner image is transferred.

According to the present embodiment, a correction value is determined in advance for each pixel on the basis of white, and when the read output of a white original is adjusted to the correction value, the ratio of the color components of the read output becomes constant regardless of the pixel. Become. That is, by this correction, the color component ratio of the read output becomes the same for the pixels of the same color, and when the color of the pixel is determined based on the color component ratio, the accuracy of the determination can be further improved. Is accurately determined.

〔The invention's effect〕

As described above, the electrophotographic apparatus according to the present invention includes a white member that is irradiated with light to read image information by the image information reading unit and provides image information equivalent to a white document, while the color mark determination is performed. Means, based on image information obtained in advance from the white member by the image information reading means, a color component ratio of image information obtained when the image information reading means reads a white original In this configuration, image information correction means for correcting the image data so as to be constant regardless of the image information is provided.

As a result, the image information is corrected on the basis of white, so that if the image information is of pixels of the same color, the ratio of the color components is the same. Therefore, when the color of the pixel is determined based on the ratio of the color components, the accuracy of the determination can be further improved. That is, the color mark can be accurately determined without being affected by variations in the characteristics of each element of the CCD mainly used as the image information reading unit.

Therefore, when the present invention is adopted, there is an effect that the reliability of editing and copying can be improved.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of a marking determination circuit. FIG. 2 is an overall configuration diagram of the copying machine. FIG. 3 is a block diagram showing the configuration of the control system. FIG. 4A is an explanatory diagram showing each color component of the read output of the white plate by each element of the CCD unit. FIG. 4B is an explanatory diagram showing the R component of the read output by each element of the CCD unit when reading a document. FIG. 4C is an explanatory diagram showing the R component of the read output by each element of the CCD unit after correction. FIG. 5 shows a conventional example and is a block diagram showing a configuration of a marking determination circuit. 1 is an optical system, 7 is a CCD unit (image information reading means), 1
6 is a photosensitive drum, 18 is a blank lamp (pixel editing means), 40 is a white plate (white member), 44 is a main control section, 50 is a blank lamp control section, 46 is a marking determination circuit (color mark determination means), 48 is CPU, 57
Reference numeral 59 denotes an AGC circuit, and reference numeral 75 denotes an image information correction unit.

Claims (1)

(57) [Claims] An image information reading means for reading image information of a document from reflected light of light illuminated on the document, and an editing area written on the document based on the image information read by the image information reading means. A color mark determination unit that determines the presence or absence of a color mark indicating the presence of a color mark, and controls the operation of the image editing unit based on the selected marker editing / copying mode and the editing area specified according to the presence or absence of the color mark. An electrophotographic apparatus adapted to edit a copied image, wherein the image information is read by the image information reading means when irradiated with light, and a white member which gives image information equivalent to a black-and-white document is provided; In the mark determination means, based on the image information previously obtained from the white member by the image information reading means, the image information reading means An electrophotographic apparatus, comprising: an image information correcting unit that corrects a color component ratio of image information obtained when a white original is read so as to be constant regardless of pixels of the white original.