JPH11320974A - Imaging apparatus, control method therefor and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image forming apparatus in which a read-in image can be formed while varying the output density every time when the image is formed a plurality of times. SOLUTION: When an image is formed on a recording medium by binarizing an image signal through a binarization circuit 1514, density of an output image is varied by varying at least any one of the developing bias for a developing unit 203 or the exposing light beam irradiating time of a laser drive circuit 1510 every time when the image is formed after start before end of a job.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a recording medium based on image data, and more particularly to an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, when controlling the density for each image formation, an image signal composed of multi-value data is set to one.
An image signal is converted into a desired density by a look-up table for density conversion for each pixel, the converted multi-valued image signal is binarized, the binarized image signal is stored in an image memory, and stored. The read image signal is read out, and laser emission is performed in accordance with data of each pixel of the binarized image signal, thereby forming an electrostatic latent image on the photosensitive drum.

Thereafter, an image is formed on a recording medium by performing development, transfer and fixing. Further, when the same image is formed a plurality of times, an image signal stored in an image memory is read out a plurality of times to form an image.

[0004]

However, in the above-described conventional image forming apparatus, since the density is converted before the image is stored in the image memory, the image stored in the image memory is converted. However, since the density cannot be changed, the density cannot be changed for each image formation when an image once read is formed a plurality of times.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to change the density of an image signal even after converting the image signal from multi-valued to binary. It is an object of the present invention to provide an image forming apparatus capable of changing a density every time, a control method thereof, and a storage medium.

[0006]

An image forming apparatus, a control method thereof, and a storage medium according to the present invention are configured as follows.

(1) An image forming apparatus has a binarizing means for converting an image signal into a binary signal, and forms an image on a recording medium using the image signal binarized by the binarizing means. An image forming apparatus, wherein the density of an output image is changed by changing at least one of a developing bias to a photoconductor and an irradiation time of a light beam for exposure for each image formation performed from the start to the end of a job. I did it.

(2) In the image forming apparatus of the above (1), the touch panel and a control means for performing control for changing at least one of the developing bias and the irradiation time of the exposure light beam in accordance with the depression of the touch panel are provided. Equipped.

(3) Control of an image forming apparatus having a binarizing means for converting an image signal into a binary signal, and forming an image on a recording medium by the image signal binarized by the binarizing means. In the method, control is performed to change at least one of the developing bias to the photoconductor and the irradiation time of the light beam for exposure according to the pressing of the touch panel.

(4) An image forming apparatus having a binarizing means for converting an image signal into a binary signal, and forming an image on a recording medium by the image signal binarized by the binarizing means. A program for realizing control of changing at least one of the developing bias to the photoconductor and the irradiation time of the light beam for exposure in response to pressing of the touch panel is stored in the storage medium.

[0011]

FIG. 1 is a sectional view showing the overall structure of an image forming apparatus according to one embodiment of the present invention.

In FIG. 1, reference numerals 100 and 200 denote an image input device and an image output device constituting the main body, respectively, and 300 denotes a circulating automatic document feeder (hereinafter referred to as RDF).
Reference numeral 400 denotes a sheet post-processing apparatus (hereinafter, a finisher).

Reference numeral 100 denotes an image input device (hereinafter, referred to as a reader unit) for converting an original into image data. Reference numeral 200 denotes a plurality of types of recording paper cassettes, which output image data as visible images on recording paper in response to a print command. An image output device (hereinafter, referred to as a printer) 250 is an external device electrically connected to the reader unit 100.

The external device 250 has various functions.
Stores information from the fax unit, file unit, external storage device connected to the file unit, computer interface unit for connection to the computer, formatter unit for converting information from the computer into a visible image, and reader unit. And an image memory unit for temporarily storing information sent from a computer, a core unit for controlling the above functions, and the like (not shown).

Documents stacked on the RDF 300 are sequentially conveyed onto the platen glass surface 102 one by one. When the original is conveyed to a predetermined position on the glass surface 102, the lamp 103 of the scanner unit is turned on and the scanner unit 10 is turned on.
4 moves to irradiate the original. The reflected light from the original passes through mirrors 105, 106, 107 and lens
The data is input to a CD (image sensor) 109. Then, the reflected light of the document irradiated on the CCD 109 is subjected to electrical processing such as photoelectric conversion, and is subjected to normal digital processing. The image signal thus obtained is input to the printer unit 200. The image signal input to the printer unit 200 is converted into an optical signal modulated by the exposure control unit 201 and irradiates the photoconductor 202. The latent image formed on the photoconductor 202 by the irradiation light is developed by the developing device 203.

The transfer paper of each size is conveyed from the transfer paper stacking unit 204 or 205 in synchronization with the leading end of the developed image, and the developed image is transferred onto the transfer paper in the transfer unit 206. Transcribed. After the transferred image is fixed on the transfer paper by the fixing unit 207,
The transfer paper is further discharged out of the apparatus. Then, the paper discharge unit 20
The transfer paper output from 8 is sorted, bound, and the like according to the operation mode specified in advance by the sorter 400.

Next, a method of forming images to be sequentially read on both sides of one output sheet (transfer sheet) will be described. After the output sheet fixed by the fixing unit 207 is once conveyed to the paper discharge unit 208, the conveyance direction of the sheet is reversed, and the output sheet is conveyed to the refeeding transfer paper stacking unit 210 via the conveyance direction switching member 209. I do. When the next original is prepared, the original image is read in the same manner as in the above process, and the photosensitive member 202 is read.
Although a latent image is formed on the upper side, the transfer sheet is fed from the transfer sheet stacking section 210 for re-feeding, so that different original images can be respectively output on the front side and the back side of the same output sheet. .

Next, the RDF 300 will be described. FIG.
FIG. 2 is a sectional view showing a configuration of the RDF 300 of FIG.

As shown in FIG. 2, the RDF 300 is provided with a loading tray 310 as a first document tray on which a bundle of documents is set.

Further, the stacking tray 310 is provided with feeding means constituting one part of the document feeding means.
This feeding means includes a half-moon roller 331, a separation conveyance roller 332, a separation motor (SPRMTR) (not shown),
A registration roller 335, a full belt 336, a belt motor (BELMTR) (not shown), a large transport roller 337, and a transport motor (FEEDMTR) (not shown)
, A paper discharge roller 340, a flapper 341, a recycle lever 342, a paper feed sensor (ENTS), an inversion sensor (TRNS), a paper discharge sensor (EFTS) (not shown), and the like.

Here, the half-moon roller 331 and the separation / conveyance roller 332 are rotated by a separation motor (SRPMTR) to move the original from the bottom of the original bundle on the stacking tray 310 to one.
Separate one by one. The registration roller 335 and the full-surface belt 336 convey the separated document rotated by a belt motor (BELTMTR) to an exposure position (sheet path c) on the platen glass surface 101 via sheet paths a and b. I do. The transport large roller 337 is rotated by the transport motor (FEEDMTR) to transport the original on the platen glass surface 101 from the sheet path c to the sheet path e. The document conveyed to the sheet path e is returned onto the stack of documents on the stacking tray 310 by the discharge rollers 340.

The recycle lever 342 detects the circulation of the original. When the original is fed, the recycle lever 342 is placed on the upper part of the original bundle, the originals are sequentially fed, and the rear end of the final original is recycled. One cycle of the document is detected by dropping under its own weight when passing through the lever 342.

In the above-mentioned feeding means, at the time of double-sided original, the original is once guided from sheet paths a and b to c, then the large conveying roller 337 is rotated and the flapper 341 is switched to guide the leading end of the original to sheet path d. Then, the sheet is passed through the sheet path b by the registration roller 335, and then the document is conveyed onto the platen glass surface 101 by the entire belt 336 and stopped, thereby turning the document over. That is, the original is reversed on the sheet paths c to d and b. In addition,
Sheet paths a to b to c to d to e of the document bundle one by one
, The document is conveyed until the recycle lever 342 detects that one cycle has been made, whereby the number of documents can be counted.

Next, the finisher will be described with reference to FIG.

FIG. 3 is a cross-sectional view showing the structure of the sheet post-processing apparatus according to the embodiment. As shown in FIG. 3, the finisher swings to engage with an engaging member 469 provided on the copying machine main body. A free hook 470;
Is engaged with the engaging member 469, whereby the sheet post-processing apparatus 400 is positioned.

On the side of the apparatus 400, a carry-in port 471 for carrying in the sheet S discharged by the discharge roller pair 208 is opened, and a deflector 472 is provided downstream of the carry-in port 471. Have been. A first transport path 473 is provided downstream of the deflector 472, and a transport roller pair 475 is disposed in the first transport path 473. Further, a discharge roller pair 476 is disposed downstream of the first transport path 473, and a processing tray 477 is disposed downstream of the roller pair 476.

The lower roller 47 of the roller pair 476 is
A part of a belt 479 is wound around 6a, and a lower end portion of the belt 479 is in contact with the processing tray 477. The tray 477 is provided with a movable width contributor 480 and a positioning plate (not shown) for aligning the width direction of the sheet S, and a rack 481 is provided below the width contributor 480. The rack 481 is provided with a stepping motor 4 disposed below the processing tray 477.
It is in mesh with a pinion gear 483 driven by 82.

Further, a stapler 485 is provided adjacent to the processing tray 477, and the stapler 485 binds the sheets S stacked on the tray 477. At the end of the tray 477, a paper discharge roller 486 is provided.
A swing roller 489 provided at one corner of a swing arm 488 supported swingably by 87 comes into contact with the swing arm.

The guide 488 has a guide lever 4
A spring 492 having one end fixed to the body frame 491 is connected to the lever 490, whereby the swing guide 488 is urged counterclockwise. Further, in the vicinity of the guide lever 490,
A disk 493 that is rotated by the swing motor M2 is provided, and a pin 495 that engages with the guide lever 490 is provided on the disk 493.

An L-shaped leaf spring 496 as viewed from the front is swingably supported near the disk 493, and a microswitch 497 is provided near the spring 496. Further, a rail plate 499 is provided on the body frame 491 so as to extend in the horizontal direction.
The rail plate 499 supports a rotatable roller 411 provided on the saw guide 410.

A tray moving table 412 is supported by the guide 410 so as to be able to move up and down. The moving table 412 is provided with a stack tray 413 having a concave base end and stacking sheets S. The swing guide 48
8, a sheet level sensor 415 for detecting the level of the sheets S stacked on the stack tray 413 is provided. The sensor 415 includes a sensor lever 416 and a photo sensor which contact the sheets S stacked on the stack tray 413. The sensor 417 is configured.

On the other hand, a second transport path 419 is provided branching to the deflector 472, and a deflector 420 is provided at the end of the transport path 419. A third transport path 421 that is bent downstream of the deflector 420
Is provided, and an inner guide surface of the transport path 421 is constituted by a table roller 422, and the transport path 421 communicates with the first transport path 473. Further, a folding conveyance path 423 is provided, which is branched to the deflector 420, and the folding section 427a is disposed downstream of the conveyance path 423. In the drawing, S5 and S6 are sheet detection sensors for detecting a sheet.

Next, the operation section and the display section will be described.

FIG. 4 is a diagram showing an example of the arrangement of the operation / display panel provided in the image forming apparatus main body 100 described above.
The operation and display panel has keys and a key / displayable LCD display.

In FIG. 5, reference numeral 503 denotes a copy start key (copy start key) which is depressed to start copying. A clear / stop key 504 functions as a clear key when pressed during standby, and as a stop key during copying and recording. This clear key is pressed to cancel the set number of copies.

Reference numeral 502 denotes a numeric keypad, which is depressed when setting the number of copies. A copy density key 505 is depressed when manually adjusting the copy density. An AE key 506 is depressed when automatically adjusting the copy density according to the density of the document or when canceling the AE (automatic density adjustment) and switching the density adjustment to manual (manual).

Reference numeral 508 denotes a cassette selection key, which is pressed to select an upper cassette, a middle cassette, and a lower paper deck. When an original is placed on the RDF 300, the key 508 is used to execute APS (automatic paper selection).
Can be selected. When APS is selected, a copy paper cassette having the same size as the original is automatically selected.

Reference numeral 509 denotes an equal-size key, which is depressed when making a copy of the same size (original size). Reference numeral 511 denotes a zoom key.
Press to specify any magnification between 4 and 142%.
Reference numerals 510 and 512 denote fixed size scaling keys, which are pressed when designating reduction / enlargement of a fixed size. Reference numeral 515 denotes a key for selecting an operation mode of the sorter. The sheet ejection method (staple, sort, group), and a staple mode / sort mode when a stapler capable of stapling sheets after recording is connected. And selection and release of folding (cross section Z shape / cross section V shape) of recorded paper.

Further, various processing can be set by the extended function key 513 and the image processing key 514. For example,
The mode includes a double-sided mode, a binding margin setting, a photo mode, a multiple processing, a page continuous shooting, and a 2 in 1 mode. Reference numeral 501 denotes an LCD display for displaying various messages, which displays information about copying. The various keys 505 to 515 described above are provided above the LCD display 501, and are realized as a touch panel 516 that transmits the display contents of the LCD display 501.

Next, the system configuration of the above-described image forming apparatus will be described.

FIG. 5 is a block diagram showing the configuration of the entire system. 1 is a reader unit, 2 is a printer unit, 3 is a communication control unit for controlling communication with the external device 20, computer 21 and facsimile. Alternatively, data is exchanged by serial communication or the like to achieve synchronization.

Here, the data transmitted from the main body to the DH includes a paper feed signal for urging the original loaded on the DH to be fed,
A discharge signal for prompting the discharge of the original on the platen glass, and a paper supply / discharge mode that determines the form of paper supply / discharge, and data transmitted from the main body to the finisher are an image forming mode and a mode for storing in the finisher. , A sheet size to be stored, a timing signal, and the like. When the operation is being performed, data indicating which function of the communication control unit 3 is used is transmitted from the reader unit and the printer unit to the DH and the finisher using communication. The communication control unit 3 is connected to the reader unit 1 by a cable, and controls signals and controls each function by a core unit 10 in the communication control unit 3.

The communication control unit 3 includes a facsimile unit 4 for performing facsimile transmission / reception, a file unit 5 for converting various types of document information into electric signals and storing them on a magneto-optical disk (external storage device 6), and code information from the computer 21. Formatter unit 8 and computer 21 for expanding image into image information
A computer interface unit 7 for interfacing with the computer, an image memory unit 9 for storing information from the reader unit 1 and temporarily storing information sent from the computer, and a core for controlling the above functions. It consists of a part 10.

Reference numeral 11 denotes a man-machine interface unit, 11a denotes a hard disk, 11b denotes a keyboard, 1
1c is a display.

Next, the reader section 1 will be described.

FIG. 6 is a circuit block diagram showing the signal processing configuration of the reader unit 1. The configuration and operation of the reader unit 1 will be described below.

The reflected light of the document irradiated on the CCD 109 is photoelectrically converted here, and is converted into electric signals of red, green and blue. The color information from the CCD 109 is amplified by the following amplifiers 110R, 110G, and 110B in accordance with the input signal level of the A / D converter 111. The output signal from the A / D converter 111 is input to the shading circuit 112, where the uneven light distribution of the lamp 103 and the uneven sensitivity of the CCD are corrected. A signal from the shading circuit 112 is input to a Y (luminance) signal generation / color detection circuit 113 and an external I / F switching circuit 119. The Y signal generation / color detection circuit 113 performs an operation on the signal from the shading circuit 112 using the following equation to obtain a Y signal.

Y = 0.3R + 0.6G + 0.1B Further, the circuit 113 has a color detection circuit that separates R, G, and B signals into seven colors and outputs a signal for each color. The output signal from the Y signal generation / color detection circuit 113 is
It is input to the scaling / repeat circuit 114. Depending on the scanning speed of the scanner unit 104, zooming in the sub-scanning direction
The scaling in the main scanning direction is performed by the scaling circuit / repeat circuit 114. Further, a plurality of identical images can be output in the main scanning direction by the scaling / repeat circuit 114.

The contour / edge emphasis circuit 115 obtains edge emphasis and contour information by emphasizing the high frequency components of the signal from the scaling / repeat circuit 114. The signal from the contour / edge enhancement circuit 115 is used for patterning, thickening, masking,
It is input to the trimming circuit 117. The marker area determination / contour generation circuit 116 reads a portion of the original written with a marker pen of a designated color to generate marker contour information, and the next patterning / thickening / masking / trimming circuit 117 outputs this contour. Perform fattening, masking and trimming from information. Also, a Y signal generation / color detection circuit 1
The patterning is performed by the color detection signal from.

The output signal from the patterning / thickening / masking / trimming circuit 117 is input to a laser driver circuit 118 and converted into various signals to drive a laser. The output signal of the laser driver circuit 118 is input to the printer unit 2 and an image is formed as a visible image.

Next, the external I / F switching circuit 119 for performing I / F with the communication control unit 3 will be described.

When outputting image information from the reader unit 1 to the communication control unit 3, the external I / F switching circuit 119 communicates image information from the patterning / thickening / masking / trimming circuit 117 via the connector 120. Output to the control unit 3. When inputting image information from the communication control unit 3 to the reader unit 1, the external switching circuit 119 inputs image information from the connector 120 to the Y signal generation / color detection circuit 113.

Each of the above-described image processing is performed according to an instruction from the CPU 122, and the area signal generation circuit 121 generates various timing signals necessary for the above-described image processing based on the values set by the CPU 122. CPU1
The communication with the communication control unit 3 is performed by using the communication function built in the communication unit 22. The SUB CPU 123 controls the operation unit (display unit) 124 and controls the SUB CPU
The communication with the communication control unit 3 is performed using the communication function built in the communication unit 123.

Next, the core section 10 will be described.

FIG. 7 is a block diagram showing a detailed configuration of the core unit 10 described above.

Referring to FIG.
1 and is connected to the connector 120 of the reader unit 1 by a cable. Communication is performed by four types of signals via the connector 131, and the signal 187 is an 8-bit multilevel video signal. The signal 185 is a control signal for controlling a video signal. The signal 181 corresponds to the CPU 1 in the reader unit 1.
22. The signal 182 is the SUB in the reader 1
-Communicate with the CPU 123. Signal 181 and signal 182
Is the communication protocol processed by the communication IC 132 and the CPU
The communication information is transmitted to the CPU 133 via the bus 183.

The signal 187 is a bidirectional video signal line, and is capable of receiving information from the reader unit 1 by the core unit 10 and outputting information from the core unit 10 to the reader unit 1. The signal 187 is connected to the buffer 140, where it is separated from the bidirectional signal into a one-way signal 188 and a signal 170.

The signal 188 is an 8-bit multi-valued video signal from the reader unit 1 and is input to the LUT 141 at the next stage. The LUT 141 converts the image information from the reader unit 1 into a desired value using a look-up table. LU
The output signal 189 from T141 is input to the binarization circuit 142 or the selector 143. The binarization circuit 142 has a simple binarization function of binarizing the multi-level signal 189 at a fixed slice level, and binarization by a variable slice level in which the slice level varies from the value of the pixel around the target pixel. It has a function and a binarization function by an error diffusion method.

The binarized information is converted into a multi-level signal of 00H when it is 0 and FFH when it is 1 and the selector 143 at the next stage.
Is input to The selector 143 selects a signal from the LUT 141 or an output signal of the binarization circuit 142. The output signal 190 from the selector 143 is input to the selector 144. The selector 144 converts output video signals from the fax unit 4, file unit 5, computer interface unit 7, formatter unit 8, and image memory unit 9 into connectors 135, 136, and 13 respectively.
7, 138, 139 and the signal 194 input to the core unit 10 and the output signal 190 of the selector 143
Selection is made according to the instruction of 133.

The output signal 191 of the selector 144 is input to the rotation circuit 145 or the selector 146. The rotation circuit 145 converts the input image signal into +90 degrees, -90 degrees,
It has the function of rotating +180 degrees. Rotating circuit 145
Converts the information output from the reader unit 1 into a binarization circuit 142.
After that, the signal is converted into a binary signal, and is stored in the rotating circuit 145 as information from the reader unit 1.

Next, in response to an instruction from the CPU 133, the rotating circuit 145 rotates and reads the stored information. The selector 146 selects either the output signal 192 of the rotation circuit 145 or the input signal 191 of the rotation circuit 145, and as the signal 193, the connector 135 with the fax unit 4, the connector 136 with the file unit 5, and the computer interface unit 7, a connector 138 with the formatter unit 8, and a connector 13 with the image memory unit 9.
9 and the selector 147.

A signal 193 is a synchronous 8-bit unidirectional video bus for transferring image information from the core unit 10 to the facsimile unit 4, file unit 5, computer interface unit 7, formatter unit 8, and image memory unit 9. The signal 194 is a synchronous type 8 for transferring image information from the fax unit 4, the file unit 5, the computer interface unit 7, the formatter unit 8, and the image memory unit 9.
A one-way video bus for bits.

The video control circuit 134 controls the synchronous bus of the signal 193 and the signal 194, and the control is performed by the output signal 186 from the video control circuit 134. The connectors 135 to 139 include:
In addition, each of the signals 184 is connected. Signal 184
Is a bidirectional 16-bit CPU bus for asynchronously exchanging data commands. Fax unit 4, file unit 5, computer interface unit 7, formatter unit 8, image memory unit 9, and core unit 1.
The transfer of information with 0 is performed by the above two video buses 193 and 193.
194 and CPU bus 184.

The signals 194 from the facsimile unit 4, file unit 5, computer interface unit 7, formatter unit 8, and image memory unit 9 are input to the selector 144 and the selector 147. The selector 144 is the CPU 1
The signal 194 is input to the rotation circuit 145 of the next stage in accordance with the instruction of 33. The selector 147 outputs the signal 193 and the signal 194
Is selected by the instruction of the CPU 133. Selector 147
Is output to the pattern matching 148 and the selector 149.

The pattern matching 148 determines whether the input signal 1
95 is performed with a predetermined pattern, and if the pattern matches, a predetermined multi-level signal is output to a signal line 196. If they do not match in the pattern matching, the input signal 195 is changed to the signal 196.
Output to Selector 149 provides signals 195 and 196
Is selected by the instruction of the CPU 133.

The output signal 197 of the selector 149 is input to the LUT 150 at the next stage. The LUT 150 converts the input signal 197 according to the characteristics of the printer when outputting image information to the printer unit 2. The selector 151 has L
The output signal 198 and the signal 195 of the UT 150 are
Select according to the instruction of 33. The output signal 199 of the selector 151 is input to the enlargement circuit 152 at the next stage.

The enlargement circuit 152 can set an enlargement magnification in the X and Y directions according to an instruction from the CPU 133. The enlargement method is a first-order linear interpolation method. The output signal 170 of the enlargement circuit 152 is input to the buffer 140. The signal 170 input to the buffer 140 is
It becomes a bidirectional signal 187 according to the instruction of the CPU 133 and is sent to the printer unit 2 via the connector 131 to be printed out. Hereinafter, a signal flow between the core unit 10 and each unit will be described.

The operation of the core unit 10 for outputting information to the fax unit 4 will be described.

The CPU 133 communicates with the CPU 122 of the reader unit 1 via the communication IC 132, and issues a document scan command. The reader unit 1 outputs image information to the connector 120 when the scanner unit 104 scans a document according to this command.

The reader unit 1 and the communication control unit 3 are connected by a cable, and information from the reader unit 1 is input to the connector 131 of the core unit 10. Further, the image information input to the connector 131 is input to the buffer 140 through the line of the multi-valued 8-bit signal 187.
The buffer 140 stores a bidirectional signal 187 according to an instruction from the CPU.
As a one-way signal via the line of signal 188
141. The LUT 141 converts the image information from the reader unit 1 into a desired value using a look-up table. For example, it is possible to skip the background of a document. The output signal 189 of the LUT 141 is input to the next-stage binarization circuit 142.

The binarization circuit 142 outputs the 8-bit multi-level signal 18
9 is converted to a binary signal. The binarization circuit 142 converts the binarized signal into two multi-level signals: 00H if the signal is 0, FFH if it is 1, and two signals. The output signal of the binarization circuit 142 is supplied to the rotation circuit 1 via the selector 143 and the selector 144.
45 or input to the selector 146. Rotating circuit 1
The 45 output signal 192 is also input to the selector 146, and the selector 146 selects either the signal 191 or the signal 192. The selection of the signal is determined by the CPU 133 communicating with the fax unit 4 via the CPU bus 184. The output signal 193 from the selector 146 is sent to the fax unit 4 via the connector 135.

Next, the operation of the core unit 10 when receiving information from the fax unit 4 will be described.

The image information from the fax unit 4 is transmitted to the connector 1
35 to the signal 194 line. Signal 1
94 is input to the selector 144 and the selector 147. To rotate and output the image at the time of fax reception to the printer unit 2 according to an instruction from the CPU 133, the selector 1
The signal 194 input to 44 is rotated by a rotation circuit 145. An output signal 192 from the rotation circuit 145 is supplied to the pattern matching 1 through the selectors 146 and 147.
48. When the image at the time of fax reception is directly output to the printer 2 according to the instruction of the CPU 133, the signal 194 input to the selector 147 is input to the pattern matching 148.

The pattern matching 148 has a function of smoothing the backlash of an image when a fax is received. The signal subjected to pattern matching is supplied to the selector 149.
Through the LUT 150. LUT 150 is
In order to output a fax-received image to the printer unit 2 at a desired density, the table of the LUT 150 is
3 can be changed. Output signal 1 of LUT150
98 is input to the enlargement circuit 152 via the selector 151.

The enlargement circuit 152 has two values (00H, F
FH) is subjected to an enlargement process by a first-order linear interpolation method. The 8-bit multi-valued signal having many values from the enlargement circuit 152 is supplied to the buffer 140 and the connector 1.
The data is sent to the reader unit 1 via the interface 31. The reader unit 1 inputs this signal to the external I / F switching circuit 119 via the connector 120. The external I / F switching circuit 119 includes:
A signal from the fax unit 4 is converted into a Y signal generation / color detection circuit 11
Enter 3 After the output signal from the Y signal generation / color detection circuit 113 is processed as described above, it is output to the printer unit 2 and an image is formed on output paper.

Next, the operation of the core unit 10 when outputting information to the file unit 5 will be described.

The CPU 133 communicates with the CPU 122 of the reader unit 1 via the communication IC 132 and issues a document scan command. The reader unit 1 outputs image information to the connector 120 when the scanner unit 104 scans a document according to this command. The reader unit 1 and the communication control unit 3 are connected by a cable, and information from the reader unit 1 is input to the connector 131 of the core unit 10.

The image information input to the connector 131 is
The buffer 140 produces a one-way signal 188. The signal 188, which is a multi-valued 8-bit signal, is converted into a desired signal by the LUT 141. The output signal 189 of the LUT 141 is input to the connector 136 via the selector 143, the selector 144, and the selector 146. That is, the data is transferred to the file unit 5 without changing the functions of the binarization circuit 142 and the rotation circuit 145, while maintaining the 8-bit multi-value.

When filing the binarized signal by communication with the file unit 5 via the CPU bus 184 of the CPU 133, the functions of the binarizing circuit 142 and the rotating circuit 145 are used. The binarization processing and the rotation processing are omitted because they are the same as in the case of the above-described fax.

Next, the operation of the core unit 10 when receiving information from the file unit 5 will be described.

The image information from the file section 5 is transmitted to the connector 1
The signal is input to the selector 144 or the selector 147 as a signal 194 via the signal 36. In the case of 8-bit multi-level filing, it is possible to input to the selector 147, and in the case of binary filing, it is possible to input to the selector 144 or 147. In the case of binary filing, the description is omitted because it is the same processing as fax.

In the case of multi-value filing, selector 147
Output signal 195 from the LUT through the selector 149
Enter 150. The LUT 150 creates a look-up table in accordance with an instruction from the CPU 133 in accordance with a desired print density. Output signal 1 from LUT 150
98 is input to the enlargement circuit 152 via the selector 151. The 8-bit multi-level signal 170 enlarged to a desired enlargement ratio by the enlargement circuit 152 is sent to the reader unit 1 via the buffer 140 and the connector 131. Reader unit 1
Is sent to the printer unit 2 and an image is formed on an output sheet, similarly to the above-described fax.

Next, the computer interface unit 7
The operation of the core unit 10 based on this information will be described.

The computer interface unit 7
It interfaces with a computer connected to the communication control unit 3. The computer interface unit 7 includes a plurality of interfaces for communicating with SCSI, RS232C, and Centronics.
The computer interface unit 7 has the above three types of interfaces, and information from each interface is transmitted to the CP via a connector 137 and a data bus 184.
It is sent to U133. The CPU 133 performs various controls based on the transmitted contents.

Next, the operation of the core unit 10 based on the information of the formatter unit 8 will be described.

The formatter unit 8 has a function of expanding command data such as a document file sent from the computer interface unit 7 into image data. When the CPU 133 determines that the data transmitted from the computer interface unit 7 via the data bus 184 is data relating to the formatter unit 8, the CPU 133 transfers the data to the formatter unit 8 via the connector 138. The formatter unit 8 expands the transferred data into a memory as a meaningful image such as a character or a graphic.

Next, a procedure for receiving information from the formatter unit 8 and forming an image on an output sheet will be described.

The image information from the formatter unit 8 is transmitted to the signal 194 line via the connector 138 by two values (0
0H, FFH). The signal 194 is input to the selector 144 and the selector 147. The selectors 144 and 147 are controlled by an instruction from the CPU 133. Hereinafter, the description is omitted because it is the same as the case of the above-described fax.

Next, the operation of the core unit 10 when outputting information to the image memory unit 9 will be described.

The CPU 133 communicates with the CPU 122 of the reader unit 1 via the communication IC 132, and issues a document scan command. The reader unit 1 outputs image information to the connector 120 when the scanner unit 104 scans a document according to this command. The reader unit 1 and the communication control unit 3 are connected by a cable, and information from the reader unit 1 is input to the connector 131 of the core unit 10. The image information input to the connector 131 is sent to the LUT 141 via the buffer 140 and the line of the multivalued 8-bit signal 187.

The output signal 189 of the LUT 141 transfers multi-valued image information to the image memory unit 9 via the selectors 143, 144, 146 and the connector 139. The image information stored in the image memory unit 9 is transmitted to the connector 139.
To the CPU 133 via the CPU bus 184.
The CPU 133 transfers the data sent from the image memory unit 9 to the computer interface unit 7 described above. The computer interface unit 7 includes the above three types of interfaces (SCSI, RS23).
2C, Centronics) to the computer via the desired interface.

Next, the case of receiving information from the image memory unit 9 will be described.

First, the computer interface unit 7
Image information is sent from the computer to the core unit 10 via the. When the CPU 133 of the core unit 10 determines that the data transmitted from the computer interface unit 7 via the CPU bus 184 is data relating to the image memory unit 9, the CPU 133 transfers the data to the image memory unit 9 via the connector 139. Next, the image memory unit 9 transmits the 8-bit multi-level signal 194 to the selector 144 and the selector 147 via the connector 139. An output signal from the selector 144 or the selector 147 is
Is output to the printer unit 2 and an image is formed on an output sheet in the same manner as the above-described fax.

Next, the RDF control device will be described.

FIG. 8 shows an RDF controller 90 according to this embodiment.
FIG. 9 is a block diagram illustrating a circuit configuration of a central processing unit (CPU) 901, a read-only memory (ROM) 902, and a random access memory (RAM) illustrated in FIG.
The control device 900 of the RDF 300 is configured by the 903, the output port 904, the input port 905, and the like. RO
A control program is stored in M902
Stores input data and work data.

The output port 904 includes various motors such as a partition member motor 906, a separation motor 907, a reversing motor 908, a belt motor 909, a paper discharge motor 910, a tray swing motor 917, a separation clutch 911, a paper feed clutch 912, and the like. A stopper SL (solenoid) 913, a weight SL914, a reversing flapper SL915, a discharge flapper 916, a jogging SL918, a brake 919, and a solenoid driving unit are connected.

The input port 905 has a sheet length detecting means 920, an entrance sensor 921, an exit sensor 922, a reversing sensor 923, a first sheet ejection sensor 924, a second sheet ejection sensor 925, a third sheet ejection sensor 926, and a separation section. Clock 927,
A belt clock 928, an inversion clock 929, a paper discharge clock 930, an upper limit SW (switch) 931, a lower limit SW 932, and a partition sensor 933 are connected. Control. Further, the CPU 901 has a serial interface function, performs serial communication with the CPU of the reader unit 1, and exchanges control data with the reader unit 1. The data transmitted from the DH to the reader unit 1 is a feed completion signal or the like indicating the completion of feeding of the document onto the platen glass.

Next, the finisher control device 1000 will be described.

FIG. 9 shows a sheet post-processing apparatus 40 according to this embodiment.
FIG. 2 is a block diagram showing a circuit configuration of a control device 1000 of No. 0. The control device of the sheet post-processing device 400 includes a control unit 1061 shown in FIG. 9. The control unit 1061 is a central processing unit (CPU) 1062 and a ROM 10 storing a control program for controlling the CPU 1062.
63, and a RAM 1065 serving as a main recording device,
An output interface 1066 for outputting a control signal to a load such as a main motor and an input interface 1067 for inputting a detection signal from each sensor are connected.

The copying machine body and the automatic document feeder 3
Similarly, each load and each sensor of 00 are connected via respective interfaces (not shown). The output interface 1066 includes a bundle transport motor M1, a swing motor M2, a stepping motor 482, a stapler motor M3, a tray elevating motor M4, and a transport motor M5.
Are connected, and the input interface 1067 is connected to the sheet detection sensors S5 and S6, a width home position (HP) sensor S7, a sheet level sensor 415, and a microswitch 497.

Each control will be described with reference to the block diagram of FIG.

First, control of the operation unit will be described.

Referring to FIG. 10, a memory 1504 includes a ROM storing program codes for controlling the operation unit and image data to be displayed on the LCD display 501, and a RAM for performing calculations. SUBCPU1
A CPU 507 for controlling the operation unit includes an A / D conversion circuit, an I / O port, and a serial communication port. The SUBCPU 1507 sequentially reads and executes program-coded instructions stored in the memory 1504. It also has a built-in serial communication port and CPU
Data transmission and reception are performed by performing serial communication with 1508.

A copy start key 503, a clear / stop key 504, a numeric keypad and other keys 502 are switches arranged on the operation unit, and are connected to the input ports of the SUBCPU 1507. It is possible to detect. A copy start key 503 is a key pressed by a user when starting a job.

The clear / stop key 504 is a key to be pressed when canceling a job. A numeric keypad 502 includes a numeric keypad for setting the number of copies, a clear key for clearing the set number of copies, an interrupt key for starting an interrupt job, and the like. The key code is converted into a predetermined key code according to the type of the pressed key and transmitted to the CPU 1508. The LCD display 501 has the number of copies,
A display such as 501 shown in FIG. 4 is displayed for displaying setting contents such as density.

The LCD drive circuit 1506 is a circuit for driving the LCD display 501, and includes a SUBCPU1
507 displays the image designated by the CPU 1508 at the designated position. A predetermined character code is assigned to each image data. The image data corresponding to the character code is read out from the memory 1504 and transferred to the LCD driver circuit 1506 to display the image data on the LCD display 501.

The touch panel 516 is an analog touch panel, and is arranged on the LCD display 501. The voltage applied in the X direction and the Y direction changes according to the pressed position. This voltage is read out by an A / D conversion circuit built in the SUBCPU 1507 to detect the pressed position. When the user presses a display such as “light” or “koi” displayed on the LCD display, the voltage applied to the touch panel 516 is reduced by the SUBCPU 150.
The position is detected by reading the data by an A / D conversion circuit built-in 7, and is converted into a predetermined key code according to the detected position, and the key code is transmitted to the CPU 1508.

The memory 1509 includes a ROM storing program codes for controlling the main body, and a RAM for performing calculations. The CPU 1508 includes an A / D conversion circuit, an I / O port, and a serial communication port. The CPU 1508 sequentially reads and executes the program-coded instructions stored in the memory 1509.
In addition, a serial communication port is built in and the CPU 150
Data is transmitted and received by performing serial communication with.

When start key 503 is pressed, SUB
Detected by the CPU 1507, converted into a predetermined key code, and transmitted to the CPU 1508. CPU1
At 508, a display instruction is issued to the SUBCPU 1507 almost simultaneously with the start of the sheet feeding and reading operations. The character code corresponding to the image data "Copying" and the display position are transmitted. SUBCPU150
At 7, the image data corresponding to the character code is transferred to the LCD drive circuit 1506 as described above, so that "Copying" is displayed on the LCD display 501.

When the display of “light” or “koi” on the LCD display, which is a display for setting the density, is pressed, the voltage of the touch panel 516 is changed to SUB as described above.
The CPU 1507 detects the voltage, converts the detected voltage into a position, and further converts the voltage into a predetermined key code.
To communicate.

Since the received key code is a key for density setting, the CPU 1508 sets the density at the time of image formation, and presses the "light" key to change the display of the pointer to the SUBCPU in real time to indicate the density setting. In the case of a code, the character code and position corresponding to the image data in which the pointer is moved to the left by one step and the key code of "Koi" is moved to the right by one step is transmitted to the SUBCPU. SUBCPU
At 1507, as described above, the image data corresponding to the character code is transferred to the LCD drive circuit 1506, so that the LCD display 501 is rewritten to display the pointer moved one step. Reference numeral 1521 denotes a clutch such as the above-described separation clutch 911 and a stopper S
A clutch and a solenoid driving circuit for driving a solenoid such as L913.

Next, an outline of the control from reading an image by the CCD to outputting a laser will be described.

The CCD 109 is arranged in the scanner of the reading unit, and when the copy start key 503 is pressed on the operation unit, the scanner is operated by the instruction of the CPU 1508 to scan the original. CCD drive circuit 1
A circuit 516 drives the CCD 109. The circuit 516 generates a clock pulse, samples and holds a voltage value corresponding to the density of each pixel of the pixel signal output by the CCD, and performs A / D conversion. The image converted to multi-value data of 00 (h) to FF (h) by A / D conversion is transmitted to the density conversion circuit 1515. The LUT 1518 is configured with a 256-byte RAM, and the density conversion circuit 1515 stores
In the case of (h), the data is converted into the data arranged in the first byte of the LUT 1518, and when the multi-valued data is 01 (h), the data is converted into the data arranged in the second byte of the LUT 1518. Perform the operation.

Since the CPU 1508 can read a predetermined density conversion table from the memory 1509 and set it in the LUT 1518, the density can be adjusted. The multi-value data converted by the density conversion circuit 1515 is transmitted to a binarization circuit (binarization means) 1514.
The binarization circuit converts multi-level data into binary data using an error diffusion method. Then, the values of 00 (h) to FF (h) are converted into binary values of 0 and 1. The binarized image signal is transmitted to the memory controller 1512 and stored in the image memory 1513 by the memory controller 1512.

The image memory 1513 has a capacity capable of storing a plurality of images. The binary image data read from the image memory 1513 by the memory controller 1512 is stored in the laser drive circuit 151 of the exposure control unit 201.
When the pixel data is 1, the laser output circuit 1511 controls the laser output unit 1511 to turn on the laser, and when the pixel data is 0, the laser drive circuit 1510 turns off the laser. 1 in the laser drive circuit 1510
It is possible to set the irradiation time per pixel (hereinafter, laser power). Normally, the mode is the HIGH mode, and when making the image thin, the mode is the LOW mode in which the laser irradiation time per pixel is short. The laser drive circuit 1510 is C
The laser power is connected to an output port of a PU (control means) 1508, and the laser power is set according to an instruction from the CPU 1508. Once set, the mode is retained until changed.

Next, the density adjustment by changing the developing bias will be described.

The voltage generating circuit 1519 is a circuit for generating a voltage (hereinafter referred to as a developing bias) to be applied to the developing roller of the developing device 203, and generates a developing bias by combining a DC voltage and an AC voltage. The voltage generation circuit 1519 is a CPU 150
8 (CPU) (control means) 150
8, the DC component of the developing bias can be set to the voltage calculated by the CPU 1508.

Based on the above description, the setting of the laser power and the setting of the developing bias, which characterize the present invention, will be described with reference to the flowchart of FIG. In addition,
This processing operation is performed according to an instruction from the CPU 1508 based on a program stored in the memory 1509 in advance.

The job is started by pressing the copy start key (step S1). With this, leader section 1
, And a paper feed operation of the transfer paper is started. In step S2, the density set on the LCD touch panel is read. One of six levels is set, such as pressing 505 in FIG. 4 one level lighter and pressing 506 in FIG. 4 one level darker. The density d is set to 0 for the lightest setting and 5 for the darkest setting.
Set the value according to the density setting of the touch panel.

In step S3, if the density d is 0, the process proceeds to step S4. If the density d is set to 1 to 5, the process proceeds to step S5. Next step S4 and step S
In step 5, the irradiation time per pixel when the photosensitive drum is irradiated with laser light to the laser driver circuit is set.
When an image is formed at a normal density, a HIGH mode is set to increase the irradiation time, and when an image is formed at a low density, a LOW mode is set to shorten the irradiation time.

In step S4, the laser power is set to the LOW mode to form a thin image, and in step S5, the laser power is set to the HIGH mode. In step S6, a developing bias voltage for applying toner to the electrostatic latent image on the photosensitive drum is calculated. The developing bias voltage is a voltage obtained by superimposing a DC voltage and an AC voltage. In step S6, a DC component V of the developing bias is calculated. V is calculated by the following equation (1).

V = −560− (30 × d) (V) (1) In step S7, a voltage having a DC component of the developing bias voltage V calculated in step S6 is applied to the developing roller of the developing machine. In step S8, an image is formed on the transfer paper.
In step S9, if the copy job is not completed, the process returns to step S2.

Further, during the period from step S2 to step S9, the control to accept the density setting by the LCD touch panel is performed.

Although the present embodiment has been described as an apparatus, the present invention may be embodied as a storage medium storing the above-described density changing method or a program for realizing the method.

As described above, in this embodiment, the developing bias is changed every time image formation is performed from the start to the end of the job, or the laser emission time per pixel is changed by the laser power control means. In the case of forming an image stored in the image memory even in an image forming apparatus configured to convert multi-valued data by a look-up table before storing the image data in the image memory because at least one control is performed. Since the density can be changed by the laser output or the developing bias, the density can be changed for each image formation when an image read once is formed a plurality of times.

Further, it is possible to provide an image forming apparatus which includes a touch panel and operation means and allows the user to change the density, so that the density can be easily changed.

[0127]

As described above, according to the present invention,
An image forming apparatus, comprising: a binarizing unit for converting an image signal into a binary signal; forming an image on a recording medium by the image signal binarized by the binarizing unit; The density of the output image is changed by changing at least one of the developing bias to the photoconductor and the irradiation time of the light beam for exposure for each image formation performed until the end, so that a plurality of images once read are read. When forming images twice, the output density can be changed for each image formation,
This has the effect of improving the user interface.

Further, since the touch panel and the control means for performing control for changing at least one of the developing bias and the irradiation time of the exposure light beam in accordance with the pressing of the touch panel are provided, the user instructs to change the output density. Thus, there is an effect that the output density can be easily changed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the configuration of the circulating automatic document feeder of FIG.

FIG. 3 is a cross-sectional view illustrating a configuration of a sheet post-processing apparatus according to an embodiment.

FIG. 4 is an explanatory diagram showing an arrangement configuration of an operation / display panel according to an embodiment;

FIG. 5 is a block diagram illustrating a system configuration of the image forming apparatus according to the embodiment;

FIG. 6 is a block diagram showing a signal processing configuration of a reader unit in FIG. 5;

FIG. 7 is a block diagram showing a detailed configuration of a core unit in FIG. 5;

FIG. 8 is a block diagram showing a configuration of a control device of the circulating automatic document feeder according to one embodiment.

FIG. 9 is a block diagram illustrating a configuration of a control device of the sheet post-processing apparatus according to the embodiment.

FIG. 10 is a block diagram illustrating a main configuration of an image forming apparatus according to an embodiment.

FIG. 11 is a flowchart illustrating a control operation of a laser power and a developing bias according to one embodiment;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 reader unit 2 printer unit 10 core unit 100 image input device (reader unit) 200 image output device (printer) 201 exposure control unit 203 developing unit 300 circulating automatic document feeder (RDF) 400 sheet post-processing device (sorter) 516 Touch panel 1504 Memory 1507 SUBCPU 1508 CPU (control means) 1509 Memory 1510 Laser drive circuit 1511 Laser output unit 1512 Memory controller 1513 Image memory 1514 Binarization circuit (Binarization means) 1515 Density conversion circuit 1518 LUT 1519 Voltage generation circuit

Claims (4)

[Claims] 1. An image forming apparatus, comprising: a binarizing unit for converting an image signal into a binary signal; and forming an image on a recording medium by the image signal binarized by the binarizing unit. The density of an output image is changed by changing at least one of a developing bias to a photoconductor and an irradiation time of a light beam for exposure for each image formation performed from the start to the end of a job. Image forming device. 2. The apparatus according to claim 1, further comprising: a touch panel; and control means for performing control for changing at least one of a developing bias and an irradiation time of an exposure light beam in response to pressing of the touch panel. Image forming apparatus. 3. A control method for an image forming apparatus, comprising: a binarizing unit for converting an image signal into a binary signal, wherein an image is formed on a recording medium by the image signal binarized by the binarizing unit. A control method for an image forming apparatus, comprising: performing control to change at least one of a developing bias to a photoconductor and an irradiation time of an exposure light beam in response to pressing of a touch panel. 4. An image forming apparatus comprising: a binarizing unit for converting an image signal into a binary signal; and an image forming apparatus for forming an image on a recording medium by the image signal binarized by the binarizing unit. A storage medium storing a program for realizing control of changing at least one of a developing bias to a photoconductor and an irradiation time of an exposure light beam in response to pressing of a button.