JP3364560B2 - Image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analog copying machine, a digital copying machine, a digital color copying machine, a facsimile,
The present invention relates to an image forming apparatus such as a color facsimile, a printer, and a color printer.

[0002]

2. Description of the Related Art An image forming apparatus supplies a plurality of sheets or one sheet feeding section for sequentially feeding sheets, and a sheet feeding section selected from one of the plurality of sheet feeding sections or one sheet feeding section. There are analog copiers, digital copiers, digital color copiers, facsimiles, color facsimiles, printers, color printers, etc. that have an image forming unit that forms an image on the formed paper, and the paper is fed by the image forming unit in the duplex mode. There is also one that forms an image on both sides of a sheet fed from a set.

Recently, it has become necessary to effectively use resources against environmental damage due to deforestation, increase the amount of garbage such as waste documents in offices, and reduce the cost related to OA (office automation). Along with this, there is an increasing number of cases in which a backing sheet (recycled sheet whose front side has been used once) is used as a copy sheet for obtaining a copy other than a formal document or a print sheet for a printer in an image forming apparatus.

Further, in Japanese Patent Laid-Open No. 6-255842, an image forming apparatus having a sheet feeding device for sequentially feeding sheets set in a sheet feeding section to an image forming section is described. A large number of reflective photosensors provided to face the back surface of the paper during conveyance of the paper to the image section, and control for determining at least one of the type and state of the paper based on detection signals from the reflective photosensors. The image forming apparatus is characterized in that the control means determines that the paper is a backing paper by the detection signal of the reflection type photo sensor and displays the paper on the display panel.

[0005]

[Patent Document 1] Japanese Patent Application Laid-Open No. 6-25584
In the image forming apparatus described in Japanese Unexamined Patent Publication No. 2 (1994), a large number of reflective photosensors are provided so as to face the back surface of the paper while the paper is being conveyed to the image forming unit, and the paper is based on the detection signals of the reflective photosensors. Control means for determining at least one of the type and the state of the paper, and the control means determines that the paper is the back paper based on the detection signal of the reflection type photosensor and displays the paper on the display panel. And, and
When forming an image such as copying or printing a formal document, the backing sheet cannot be used as a sheet, but the backing sheet is used, resulting in an image forming error (an image is formed on the image-formed side of the sheet. In some cases, a mistaken copy or mistaken print may occur due to the mistake.
Also, while it is possible to automatically detect the backing paper,
Since it is necessary to install a large number of reflective photosensors in order to improve the detection accuracy, the cost is increased.

Further, generally, a document created by using a backing paper in an image forming apparatus causes the show-through to a greater or lesser extent, which makes it difficult to see the user side (front side). Also, when images are formed on both sides of the paper in the duplex mode, if a backing paper is set in the selected paper feed unit, images are formed on both sides of the backing paper A mistake such as forming an image on the finished surface) causes a miscopy or a misprint.

Further, when the backing sheet is set in the paper feeding section with the front side and the back side thereof reversed, an image is formed on the used back side of the backing sheet to cause an image forming error, thereby causing a miscopy or a misprint. Will occur. SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of preventing image forming errors and reducing adverse effects due to show-through of a backing sheet.

[0008]

In order to achieve the above object, the present invention according to claim 1 provides a plurality of or one sheet feeding section for sequentially feeding sheets, and a sheet fed from this sheet feeding section. In an image forming apparatus having an image forming unit for forming an image on a sheet, a recognition unit that recognizes that the backing sheet is used when the backing sheet is set in the paper feeding unit, and the backing sheet is recognized by the recognition unit. And a display unit that indicates the setting state of the backing paper when recognizing that it is used, the image forming unit forms an image on the paper from the paper feeding unit by the image signal processed by the image processing unit, The selected paper feed unit includes a plurality of paper feed units that feed paper, and the image processing unit is configured such that a backing paper is set in the selected paper feed unit of the plurality of paper feed units. Image signal processing conditions so that the image density shifts to the high density side when It is intended to change.

According to a second aspect of the present invention, a selected one is provided with a plurality of sheet feeding units for sequentially feeding the sheets, and an image forming unit for forming an image on the sheets fed from the sheet feeding units. In the image forming apparatus, the recognition unit that recognizes that the backing sheet is used when the backing sheet is set in the paper feeding unit and the backing unit when the recognition unit recognizes that the backing sheet is used When the backing paper is set in the selected paper feeding unit of the plurality of paper feeding units by performing the process control of the image forming unit and the display unit showing the setting state of the paper, the image density is higher than usual. It is provided with process control means for changing the process control conditions so as to shift to the high concentration side.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows an outline of an embodiment of the present invention, and FIG. 3 shows a part thereof. This example embodiment
It is an embodiment of the invention described in claims 1 to 3, and is an example of a digital color image forming apparatus including a digital color copying machine. The image reading apparatus 1 starts the reading operation by a scanner start command from the system control unit, illuminates the document set on the document table 3 by the automatic document feeder 2 with the illumination lamp 5, and mirrors the reflected light image. 3 lines CC via groups 6-8 and lens 9
An image is formed on the color sensor 10 made of D, and the original on the original table 3 is scanned by moving the illumination lamp 5 and the mirror groups 6 to 8 so that the color image information of the original is, for example, blue (hereinafter referred to as B), green ( Each color (hereinafter referred to as G) and red (hereinafter referred to as R) is color-separated and read, and converted into an electrical image signal.

B, G, R obtained by the color sensor 10
The image signal for each color of
An image processing unit 1 which has been D-converted and serves as an image processing means.
1 receives image processing such as scanner (image reading apparatus 1) γ correction, color conversion, main scanning scaling, image separation, processing, area processing, gradation correction processing, printer (color image recording apparatus 12) γ correction. Conversion to color image data of black (hereinafter referred to as K), cyan (hereinafter referred to as C), magenta (hereinafter referred to as M), and yellow (hereinafter referred to as Y) for visualization in the color image recording device 12. To be done.

The color image data of K, C, M, and Y are output to the color image recording device 12 in synchronization with the scanner start signal of the image reading device 1 for each color. By repeating this operation a total of 4 times, 4
The color image data for each color is sequentially visualized in the color image recording device 12, and these are superimposed to form a full-color image.

In the color image recording apparatus 12, the image writing unit 13 as an exposing means converts the color image data from the image processing unit 11 into an optical signal to form an image carrier made of a photoconductor, for example, a photoconductor drum. 14
An optical latent image is formed by performing optical writing corresponding to the original image. The image writing unit 13 drives and modulates the semiconductor laser 15 with the color image data from the image processing unit 11 by a light emission drive control unit (not shown), and emits laser light whose intensity is modulated with the color image data. The laser light is deflected and scanned by the rotary polygon mirror 17 which is rotationally driven by the motor 16, and is irradiated onto the photosensitive drum 14 via the f / θ lens 18 and the reflection mirror 19.

The photoconductor drum 14 is driven to rotate by a drive unit and rotates counterclockwise as shown by an arrow. Around the photoconductor drum 14, a photoconductor cleaning device (cleaning blade or pre-cleaning device) is provided along the rotation direction. A charge removing device 21 is included), a charge removing lamp 22, a charging device 23 as a charging unit, a K developing device 24, a C developing device 25, an M developing device 26, a Y developing device 27, an intermediate transfer belt 28, and the like are arranged. .

Each color developing device 24-27 as developing means
Is a developing roller 2 which is arranged in parallel with the photosensitive drum 14 and forms a developing brush (brush of developer) for developing the electrostatic latent image on the photosensitive drum 14 and rotates in the direction of the arrow in the figure.
41, 251, 261, 271.

Each color developing device 24-27 includes a developing roller 24.
When the developing roller drive motors 1, 251 and 261 and 271 are driven in the reverse direction, the developing state and the developing state are switched. That is, the developing roller 241,
Nos. 251, 261, and 271 are in a non-development state because the developer spikes up when the forward rotation of the developing roller drive motor causes the developer to be developed, and when the reverse rotation occurs due to the developing roller drive motor, the developer is in the spike cutting state. Becomes

Further, in the intermediate transfer portion including the intermediate transfer belt 28, the intermediate transfer belt 28 is connected to the photosensitive drum 1.
Bias rollers 29, 30, a transfer belt driving roller 31, which can be rotated in the forward and reverse directions, and driven rollers 32, 3.
3 and is rotationally driven by the transfer belt drive roller 31. The intermediate transfer belt 28 comes into contact with the photoconductor drum 14 by bias rollers 29 and 30, and a transfer bias is applied from a transfer power source through the bias rollers 29 and 30 to form toner images of respective colors on the photoconductor drum 14. Overprinted.

The paper transfer unit 32 as a transfer means is
It has a paper transfer bias roller 33 arranged to face the intermediate transfer belt 28. The paper transfer bias roller 33 is
Normally, it is separated from the intermediate transfer belt 28, but when the four-color superimposed image formed on the intermediate transfer belt 28 is collectively transferred to the paper, it is pressed by the contact / separation mechanism at a timing and the intermediate transfer is performed. A transfer bias is applied from the transfer power source to the paper transfer bias roller 33 so that the toner image on the intermediate transfer belt 28 is brought into contact with the belt 28 and the transfer belt driving roller 31 transfers the paper image to the paper transfer bias roller 33 and the intermediate transfer belt 28. It is transferred to the paper passing between them.

The intermediate transfer belt 28 after the toner image is transferred onto the paper is cleaned by the intermediate transfer belt cleaning unit 34. Further, the intermediate transfer belt 28 is brought into contact with and separated from the photosensitive drum 14 by a contacting / separating mechanism, and the paper transfer bias roller 33 is brought into contact with and separated from the intermediate transfer belt 28 by a contacting / separating mechanism. The intermediate transfer belt cleaning unit 34 is brought into contact with and separated from the intermediate transfer belt 28 by a contacting / separating mechanism.

Next, the order of color image forming operation (developing operation of each color) (color image forming operation order) is K developing operation, C
The development operation, the M development operation, and the Y development operation will be described in this order. However, the order of developing operations for each color is not limited to the above order. When the color image forming operation is started, the image reading device 1 starts the reading operation for obtaining the K image data at a predetermined timing, outputs the color image data to the image processing unit 11, and the image processing unit 11 outputs the image. The color image data from the reading device 1 is processed and K image data is output to the color image recording device 12.

In the color image recording apparatus 12, the photosensitive drum 14 rotates and is uniformly charged by the charger 23, and the image writing unit 13 becomes the image processing unit 11.
Based on the K image data input from the photoconductor drum 1
An optical latent image is formed by performing optical writing on laser beam 4 by using laser light. Hereinafter, the electrostatic latent image based on this K image data is referred to as a K latent image. Similarly, the electrostatic latent images formed by the C, M, and Y image data are referred to as C latent image, M latent image, and Y latent image.

This K latent image is developed by the K developing device 24 to become a K toner image, and the K toner image on the photosensitive drum 14 is the surface of the intermediate transfer belt 28 driven at the same speed as the photosensitive drum 14. (Hereinafter, the toner image transfer from the photosensitive drum 14 to the intermediate transfer belt 28 is referred to as belt transfer). The belt transfer is performed by applying a predetermined bias voltage from the transfer power source to the transfer bias roller 29 while the photosensitive drum 14 and the intermediate transfer belt 28 are in contact with each other. After the transfer of the K toner image, the photoconductor drum 14 is subjected to charge removal and cleaning by a photoconductor cleaning device 21 including a pre-cleaning charge remover 20.

Next, the K image forming step, the C image forming step, the M image forming step, and the Y image forming step are sequentially performed, and the developing step for developing the electrostatic latent image on the photosensitive drum 14 is performed. The belt transfer process is performed in the same manner as the K image forming process. That is, on the side of the photosensitive drum 14, the C image forming process is performed after the above K image forming process. In this C image forming process, the image reading apparatus 1 starts reading for obtaining C image data at a predetermined timing. , The photosensitive drum 14 is uniformly charged again by the charger 23,
The image writing unit 13 performs optical writing with a laser beam on the photosensitive drum 14 based on the C image data obtained from the image reading device 1 via the image processing unit 11 to form a C latent image.

The C latent image is developed by the C developing device 25 to become a C toner image, and the C toner image on the photosensitive drum 14 is transferred onto the surface of the intermediate transfer belt 28 so as to be superposed on the K toner image. After the transfer of the C toner image, the photoconductor drum 14 is subjected to static elimination and cleaning by the photoconductor cleaning device 21 including the pre-cleaning static eliminator 20, and is uniformly charged again by the charger 23.

On the photosensitive drum 14 side, the C image forming process is followed by the M image forming process. In this M image forming process, the image reading device 1 starts reading for obtaining M image data at a predetermined timing. Image writing unit 1
3 is based on the M image data obtained from the image reading device 1 via the image processing unit 11
An optical latent image is formed by performing optical writing with a laser beam.

This M latent image is developed into an M toner image by the M developing device 26, and the M toner image on the photosensitive drum 14 is transferred onto the surface of the intermediate transfer belt 28 so as to be superposed with the K toner image and the C toner image. To be done. After the transfer of the M toner image, the photoconductor drum 14 is subjected to static elimination and cleaning by the photoconductor cleaning device 21 including the pre-cleaning static eliminator 20, and is again uniformly charged by the charger 23.

On the photosensitive drum 14 side, the M image forming process is followed by the Y image forming process. In this Y image forming process, the image reading device 1 starts reading for obtaining Y image data at a predetermined timing. Image writing unit 1
3 is a photosensitive drum 14 based on Y image data obtained from the image reading device 1 via the image processing unit 11.
Then, optical writing is performed by laser light to form a Y latent image. The Y latent image is developed by the Y developing device 27 to become a Y toner image, and the Y toner image on the photosensitive drum 14 is superposed on the surface of the intermediate transfer belt 28 with the K toner image, the C toner image and the Y toner image. Transcribed.

As for the paper, the first paper feeding section 35, the second paper feeding section 36,
The paper feed roller 3 is selected from the one selected from the third paper feed unit 37.
The sheet is fed to the registration roller 43 by any of 9 to 41, or the sheet manually fed from the manual sheet feeding unit 38 is fed to the registration roller 43 by the sheet feeding roller 42. The registration roller 43 sends out the paper at the timing when the leading edge of the four-color superimposed image on the intermediate transfer belt 28 reaches the paper transfer position. The four-color superposed toner images are collectively transferred from the intermediate transfer belt 28 by the paper transfer unit 32 to the sheet, and the sheet is conveyed to the fixing section 45 by the conveying belt 44 and is fixed by the fixing roller and the pressure roller at the fixing section 45. The toner image is fixed and discharged by the discharge roller 152. In the normal single-sided copy mode, the paper from the paper discharge roller 152 is discharged to the outside as a full-color copy by the switching claw 153 and the paper discharge roller 154.

In the double-sided mode, the discharge roller 152
The single-sided copy sheet (the sheet on which the full-color image has been transferred and fixed on one side as described above) is conveyed by the switching claw 153 to a reversing unit (not shown) and the front and back sides thereof are reversed, and then the conveyance rollers 155, 156. It is discharged to the intermediate tray 157. After that, the paper in the intermediate tray 157 is fed by the paper feed roller 158 and conveyed to the registration roller 43, and the full-color image of the next original set on the original table 3 is displayed on the intermediate transfer belt 28 as described above. Is formed similarly to.

The registration roller 43 sends the one-sided copy sheet with the leading edge aligned with the full-color image on the intermediate transfer belt 28. The paper from the registration roller 43 is transferred by the paper transfer unit 32 to the full-color image on the intermediate transfer belt 28, conveyed by the conveyor belt 44 and fixed by the fixing unit 45, and then ejected by the paper ejection roller 152. To be done. The paper from the paper discharge roller 152 has a full-color image transferred and fixed on both sides, and is discharged to the outside as a double-sided full-color copy by the switching claw 153 and the paper discharge roller 154.

The operation mode such as the copy mode set by the user is input and set by the operation section unit 46 as the operation means and sent to the system control unit 47 as the system control means. The system control unit 47 performs a control process for executing the setting copy mode according to the signal sent from the operation unit 46. At this time, the system control unit 47 includes an image reading unit 1, an image processing unit 11, an image writing unit 13, an image display unit 48 as a display unit,
The copy mode is executed by giving a control instruction to the mechanical section 49 of this copying machine.

When the image read by the image reading unit 1 is displayed on the image display unit 48, the image reading unit 1 starts the document reading operation according to the control instruction (scanner start command) from the system control unit 47, and the image reading is performed. The image signal from the unit 1 is subjected to image processing suitable for display on the image display unit 48 in the image processing unit 11, and then the image display unit 4
The image read out by the image reading unit 1 is displayed on the image processing unit 11.

The image display unit 48 is, as shown in FIG. 4, an image data level converter 50 as a driver / receiver, a FIFO memory (line buffer) 51, a CPU.
52, DR for storing image data as image data memory
AM 53, ROM 54, SRAM 55, VRAM (video memory) 56, serial level conversion unit 57 as a serial communication driver, liquid crystal display (LCD) controller 58, LCD panel 59 as a display, keyboard 60 of operation unit 46. Signal is input from.

The image data output from the image processing unit 11 to the image display unit 48 is subjected to image data storage DR by the DMA controller built in the CPU 52 via the image data level conversion unit 50 and the FIFO memory 51.
It is stored in AM53. Since the image display unit 48 receives the image data control signal together with the image data,
It is possible to take image data into the DRAM 53 only in the effective image area.

The image data of the effective image area taken in the DRAM 53 is transferred to the VRAM 56 by the CPU 52.
MA is transferred. At this time, the CPU 52 causes the DRAM
It is also possible to transfer an arbitrary part of the image data in 53 to the VRAM 56 and to perform processing such as enlargement, reduction and thinning. The image data transferred to the VRAM 56 is displayed on the LCD panel 59 under the control of the LCD controller 58.

FIG. 5 shows the surface of the image display unit 48. The LCD panel 59 displays an image read by the image reading unit 1 and is used for designating an area, a document color, and the like. Further, the LCD panel 59 displays a scale 61 for indicating a standard size of the document and a cursor 62 for indicating a position of a designated point. The image processing unit 11 has a clear key 63 for canceling the last designated point, an all clear key 64 for canceling all the designated points,
Close key 6 to connect the start and end points when specifying the area
5, a point designation key 66 for designating the point indicated by the cursor 62, a cursor key 67 for moving the cursor 62, a screen movement key 68 for moving the screen,
Enlarge key 6 for enlarging the image centering on the cursor 62
9 to 71, whole key 7 for displaying the whole image
2. A brightness adjustment knob 73 for adjusting the brightness of the LCD panel 59, a contrast adjustment knob 74 for adjusting the contrast of the LCD panel 59, and a reading key 75 for starting the reading of a document are provided.

The enlargement keys 69 to 71 display the entire image about 15 times.
The LCD panel includes a magnifying key 69 for magnifying and displaying 0%, a magnifying key 70 for magnifying and displaying the entire image to approximately 200%, and a magnifying key 71 for magnifying and displaying the entire image to approximately 300%. Reference numeral 59 indicates a magnifying key selected from the magnifying keys 69 to 71 with a mark 76. The image display unit 48 may also serve as a display editor for displaying an image on the LCD panel 59 and designating an area for editing / processing / mode setting within the screen.

FIG. 6 shows the operation unit 46. The operation unit 46 includes a numeric keypad 77, a mode clear / preheat key 78, an interrupt key 79, an image quality adjustment key 80, a program key 81, a print start key 82, a clear / stop key 83, an area processing key 84, a brightness adjustment knob 85, It has a touch panel key 86, a layout mode key 87, and the like arranged on the LCD panel 59.

The numeric keypad 77 is used to input a numerical value such as the number of copies. The mode clear / preheat key 78 is used to cancel the set mode and return to the initial setting, or to set the preheat state by continuously pressing for a predetermined time or longer. The interrupt key 79 is used when an original different from the original being copied is interrupted during the copying operation. The program key 81 is used to register or call a frequently used mode.

The print start key 82 is a key for instructing the start of copying. Clear / Stop key 83
Is used to clear the input numerical value or to suspend the copying operation during the copying operation. The area processing key 84 is used when a mode such as area processing / editing is used on the image display unit 48 (display editor). The brightness adjustment knob 85 adjusts the brightness of the screen of the LCD panel 59. Touch panel key 86 is LC
When a key area is set in the same range as the range of various keys displayed on the D panel 59 and the touch panel detects a press within the set range, the set key is processed. The layout mode key 87 is a start key for displaying an image on the image display unit 48.

FIG. 7 shows a display example of the LCD panel 59.
On the screen of the LCD panel 59, there are mode selection displays such as color mode, automatic density, manual density, image quality mode, manual or automatic paper selection, paper feed unit, automatic paper scaling, normal magnification, sorting, and stacking. There are also sub-screen selections such as create, color processing, both sides, and scaling. A key having the same size as the size of each of these displays is set on the touch panel.

FIG. 8 shows an example of screen development by pressing the double-sided key on the LCD panel 59. When the double-sided key is pressed, the LCD panel 59 scrolls up the double-sided setting screen from the bottom of the screen. The duplex setting screen includes a single-sided → double-sided key 88 for making a double-sided copy from a single-sided original, a double-sided → double-sided key 89 for making a double-sided copy from a double-sided original, and a double-sided → single-sided key 90 for making a single-sided copy from a double-sided original.
When any of these is pressed, a mode for making a double-sided copy from a single-sided original, a mode for making a double-sided copy from a double-sided original, and a mode for making a single-sided copy from a double-sided original are set.

FIG. 9 shows an example of the touch panel detection circuit of the touch panel key 86. Controller 91 detects /
The measurement terminal and the X / Y terminal are set to 0 or 1 of the binary signal, and the terminals X1, X2, Y1, and Y2 of the touch panel key 86 are set as shown in FIG. 10 to detect the pressed position of the touch panel key 86. The terminal Y2 is pulled up by the resistor R. When the detection / measurement terminal and X / Y terminal are 0,
The output of the OR circuit 92 becomes low potential (L), the output of the inverter 102 becomes high potential (H), the analog switch 93 is turned on, the analog switch 94 is turned off, and the gates 95 and 96 are in a high impedance state ( Z), the terminal X2 becomes Z, and the terminal X1 is connected to the input side Vin of the A / D converter 97. Further, the outputs of the inverters 98 and 99 become H, the gates 100 and 101 are turned on, the terminal Y2 becomes L, and the terminal Y1 becomes H.

When the detection / measurement terminal is 0 and the X / Y terminal is 1, the output of the OR circuit 92 and the inverter 99.
Becomes H, the analog switch 94 is turned on, the analog switch 93 is turned off, the gates 95 and 96 are turned on, and the terminal X2 becomes L. Then, the output of the inverter 98 becomes L, the gates 100 and 101 become Z, and the terminal Y2 becomes Z. Further, the terminal X1 becomes H, and the terminal Y1 is connected to the input side Vin of the A / D converter 97.

When the detection / measurement terminal becomes 1, the output of the OR circuit 92 becomes H, the analog switch 94 is turned on, the analog switch 93 is turned off, and the gate 95,
96 turns on and the terminal X2 becomes L. Then, the output of the inverter 98 becomes L, the gates 100 and 101 become Z, and the terminal Y2 becomes Z. Further, the output of the inverter 99 becomes L, the terminal X1 becomes L, and the terminal Y1 becomes A /
It is connected to the input side Vin of the D converter 97. At this time, since the terminal Y2 is pulled up by the resistance R, if the touch panel key 86 is off, the input side Vin of the A / D converter 97 becomes H and the touch panel key 86
When is turned on, Vin on the input side of the A / D converter 97 becomes 0V.

Therefore, the controller 91 uses the A / D
The on / off state of the touch panel key 86 is confirmed from the output of the converter 97. When the controller 91 detects the ON state of the touch panel key 86, the detection / measurement terminal is set to 0 to switch the measurement mode, and the X / Y terminal is set to 1 to input the position in the X direction. At this time, the terminal X1 is + 5V
Then, the terminal X2 becomes 0V, and the potential at the pressed position of the touch panel key 86 is converted into a digital value by the A / D converter 97 through the terminal Y1 and input to the controller 91.

Further, the controller 91 inputs the position in the Y direction with the X / Y terminal set to 0. At this time, the terminal Y1 becomes + 5V and the terminal Y2 becomes 0V, and the touch panel key 86
The potential at the pressed position is converted into a digital value by the A / D converter 97 through the terminal X1 and input to the controller 91. In this way, the pressed position of the touch panel key 91 is detected.

FIG. 11 shows a control system of the operation unit 46. In the operation unit 46, the address signal from the CPU 103 is fetched by the address latch 104 and controlled by the signal from the CPU 103. A part of the address signal from the address latch 104 is decoded by the address decoder 105 and becomes a chip select signal for each IC, which is used for creating a memory map.
The address signal from the address latch 104 is R
It enters a memory such as the OM 105 or the LCDC (LCD controller) 58 and is used for addressing.

On the other hand, the CPU 103 is connected to the memory or the LCDC 58 via a data bus and performs bidirectional data communication with these. The LCDC 58 is the LCD driver 10
6, keyboard 60, analog touch panel 86, LC
An LCD panel 59 including a D module, a ROM 107 and a RAM 108 for displaying data, etc. are connected.
The LCDC 58 uses the signal from the keyboard 60 and the signal from the analog touch panel 86 to read the ROM 107 and R.
Display data is created from the data of the AM 108 and the display on the LCD panel 59 is controlled.

Further, the CPU 103 is the optical transceiver 1
An optical fiber connector is connected via 09, and communicates with the outside via the optical transceiver 109.
When the CPU 103 receives a command from the outside via the optical transceiver 109, the CPU 103 determines the display content on the LCD panel 59, expands the CGROM code, which is screen data stored in the ROM 105 in advance, on the RAM 108, and the LCDC 58 displays the code. R for the CGROM code
OM107 converts many bit patterns to LC
Display it on the D panel 59. Further, the CPU 103 uses the system reset unit 110 to send the address decoder 10
Exchange data with 5.

Next, the backing sheet detection of this embodiment will be described. First, as shown in FIG. 12, the paper feed units 35 to 37 are paper feed trays 35a to 35 made up of universal trays.
7a, and size detection units 111 to 113 and backing paper detection units 114 to 116 are installed, respectively. The paper feed trays 35a to 37a are provided so as to be able to pull out (open and close) so that paper can be set, and FIG. 13A shows a state in which the paper feed tray 35a is pulled out (opened).
(B) shows the size detection unit 111 and the back paper detection unit 114.

The size detector 111 is the push switch 1
17 to 121 and a size selection lever 122, a plurality of push switches 117 to 121 are provided corresponding to a plurality of paper sizes. The size selection lever 122 is laterally movably attached to the upper end of the paper feed tray 35a on the back side, and the pressing plate 123 is integrally fixed to the back side.
The pressing plate 123 is provided with a recess 124 that does not press any one of the push switches 117 to 121. The size selection lever 122 is laterally moved by the user and set at a position corresponding to the size of the paper set in the paper feed tray 35a.

The push switches 117 to 121 are fixed at positions facing the pressing plate 123 in this embodiment, and correspond to the size of the sheets set in the paper feed tray 35a when the paper feed tray 35a is mounted. Do 1
One push switch is not pressed by the concave portion 124 of the pressing plate 123 and remains off, but when the other push switch is pressed by the pressing plate 123 and is turned on, the sheets set in the paper feed tray 35a. Detect the size of.

The backing paper detection unit 114 has a push switch 125 and a backing paper selection lever 126, and the backing paper selection lever 126 is attached to the upper end of the paper feed tray 35a so as to be movable in the lateral direction. Also, the backing paper selection lever 126
The pressing plate 127 is integrally fixed to the back side.
23 is a recess 1 slightly larger than the push switch 125.
28 is provided. The backing paper selection lever 126 is moved laterally by the user according to whether the paper set in the paper feed tray 35a is a backing paper or an unused paper, and the backing paper corresponding position and the unused paper correspondence are set. Set selectively to position.

The push switch 125 is fixed at a position facing the pressing plate 127 in this embodiment, and when the paper feed tray 35a is mounted and the backing paper is set in the paper feed tray 35a, the push switch 127 is pressed. Is not pressed by the recessed portion 128 of the sheet feeding tray 3 and remains off.
When the backing sheet is set in the sheet 5a, it is pressed by the pressing plate 127 and turned on, thereby detecting whether the sheet set in the sheet feeding tray 35a is the backing sheet or the unused sheet. . The size detection units 112 and 113 and the back paper detection units 115 and 116 are configured similarly to the size detection unit 111 and the back paper detection unit 114, and the paper feed trays 36 a and 37.
Similarly, the size and direction of the sheet set in a and whether the sheet is a back sheet or an unused sheet are detected.

FIG. 1 shows the control system of this embodiment. The sequence control unit 130 includes a CPU 131 that controls the mechanical unit of this embodiment, a ROM 132 that stores programs and data executed by the CPU 131, and a RAM 13.
3 and an I / O controller 134 for controlling each input / output load to be controlled, and the system control unit 4
The input / output load is controlled on the basis of an instruction from 7, and the image forming operation as described above is performed.

A size detection push switch 135 including push switches 117 to 121 provided on the paper feed tray 35a, a back paper detection push switch 125 provided on the paper feed tray 35a, and a size provided on the paper feed tray 36a. Detection push switch 136, backing paper detection push switch 13 provided on the paper feed tray 36a
7, a size detection push switch 138 provided on the paper feed tray 37a, and a back paper detection push switch 139 provided on the paper feed tray 37a are connected to the CPU 131 via the I / O controller 134, and The signal is transmitted to the system control unit 47 via the sequence control unit 130.

The sequence control unit 130 and the system control unit 47 perform serial communication. The system control unit 47 uses the push switches 135 to 139 and 125.
To the operation unit 46, and the operation unit 46 receives the detection signal from each of the paper feed trays 35a.
The size and direction of the paper within 37a are displayed on the LCD panel 59 as shown in FIG.

The sequence control unit 130 also supplies a high-voltage power source for applying a developing bias to the developing units 24-27, a power source for applying a potential to the grid of the charger 23 composed of a scorotron charger, and a semiconductor laser for driving the semiconductor laser 15. The power supply for applying the transfer bias to the drive circuit, the bias roller 29, and the paper transfer bias roller 33 is controlled, and other input / output loads are controlled.

Further, the sequence control unit 130, based on an instruction from the system control unit 47, if the user selects one of the papers in the paper feed units 35 to 37 with the operation unit unit 46, the manual paper feed is performed. In the selection mode, the paper is fed from the paper feed unit selected by the operation unit unit 46 of the paper feed units 35 to 37, and the user does not select any of the paper in the paper feed units 35 to 37 by the operation unit unit 46. In this case, in the automatic paper selection mode, the paper is fed from the paper feeding unit in which the most suitable one of the papers in the paper feeding units 35 to 37 is set.

In the display example of the LCD panel 59 shown in FIG. 14, a normal unused sheet of A4 size is set vertically in the sheet feed tray 36a, and a normal unused sheet of A3 size is set in the sheet feed tray 37a in a horizontal direction. And the A4 size backing paper is set vertically in the paper feed tray 35a. When the user sets the A4 size backing paper in the paper feed tray 35a in the portrait orientation, the user sets the size and direction of the paper to the A4 size sideways position with the size selection lever 122, and similarly the backing paper selection lever 126 is set. To the position on the back side.

In this state, when the paper feed tray 35a is closed, the detection signal based on the combination of ON / OFF of the push switches 117 to 121 corresponding to the A4 size and the vertical orientation of the paper in the paper feed tray 35a, and the paper feed tray. A detection signal generated by turning off the push switch 125 according to the backing paper set in the reference numeral 35a is transmitted via the I / O controller 134 to the CPU 131.
And the paper in the paper feed tray 35a is A4 size,
The coded data that is the vertical backing paper is transmitted from the CPU 131 to the system control unit 47 as serial data.

The system control unit 47 has a non-volatile memory for storing data relating to the paper in each of the paper feed trays 35a to 37a. The data is sent from the CPU 131 to the size and direction of the paper in the paper feed tray 35a and the back side. It is updated with data indicating whether or not it is paper, and the data is stored in the nonvolatile memory even when the power is turned off. The system control unit 47 causes the image display unit 48 to use the data in the nonvolatile memory to feed the paper feed tray 35a.
It is displayed on the LCD panel 59 as shown in FIG. 14, for example, whether or not the backing paper is set on the sheets 37a to 37a.

As a result, the user uses the operation unit 46 to feed the paper feed tray 35a when the backing paper may be used and when the backing paper should not be used as in a formal document.
This can be dealt with by selecting any one of ~ 37a. Further, since the paper feed trays 35a to 37a are provided with a backing paper selection lever, the backing paper selection lever can be set at the same time when the backing paper is set in the paper feeding tray. , It is possible to minimize the mistake of setting the backing paper in the paper feed tray.

Next, the paper feed tray 35 on which the backing paper is set
The copying operation when a is selected by the user will be described. Print start key 8 of operation unit 46
When 2 is pressed, the CPU 103 causes the operation unit unit 46 to
Each of the modes selected by the keys 77 to 84, the brightness adjustment knob 85, the touch panel key 86, the layout mode key 87, etc. is transmitted to the system control unit 47 via the optical transceiver 109 as a serial communication command. The system control unit 47 transmits operation mode data to each unit in response to a serial communication command from the operation unit 46 before the image forming operation, and sets each mode to the mode selected by the operation unit 46.

When the back paper is set in the paper feed tray when the system control unit 47 transmits the back paper data in the non-volatile memory based on the detection signals from the push switches 125, 137 and 139 to the image processing unit 11. The density control will be described. Image processing unit 1
In 1, the CPU normally uses the image processing parameters of the lookup table (scanner γ correction data for unused paper,
Scanner γ correction for the image signal of each color from the color sensor 10 by the printer γ correction data)
Although the correction is performed, when the back paper data (data indicating that the back paper is set in the selected paper feed unit) is received from the system control unit 47, the CPU shifts the image density to the high density side as a whole. (Or the printer γ is turned on) so that the image processing parameters of the lookup table are changed so that the scanner γ correction data for the unused paper and the printer γ correction data are the scanner γ correction data for the back paper and the printer γ.
Switch to correction data.

In this state, the scanner start command is transmitted from the system control unit 47 to the image reading unit 1, the image reading unit 1 starts scanning the original, and the image reading unit 1 sends the image data to the image processing unit 11. To be Image processing unit 11
From the image reading unit 1 to the interface 14
The image data input via 0 is processed for each function in each block as shown in FIG.
In block 141 for correction, the printer γ correction data for the backing paper is set in the lookup table.
The look-up table is used to perform printer γ correction so that the image data has a higher density than usual. Similarly, in the scanner γ correction block 142, the scanner γ correction data for the backing paper is set in the look-up table. Therefore, the look-up table causes the scanner γ correction data to have a higher density than usual. Make a correction.

Next, the image processing unit 11 will be described. As shown in FIG. 15, the image data of each color of R, G, and B input from the image reading unit 1 to the image processing unit 11 via the interface (I / F) 140 is converted by the scanner γ / dot correction block 142 into 1 The dot deviation within the line is corrected, and the data is corrected to be linear data with respect to the reflectance of the document by scanner γ correction using a look-up table method.

This scanner γ / dot correction block 14
The image data corrected by 2 is input to the image separation processing unit 143 and the RGB filter / color conversion processing block 144. The image separation processing unit 143 performs image data ACS (chromatic / achromatic determination) processing and image area separation (character / character).
Halftone dot) processing is performed, and in ACS processing, black and gray of image data are determined. In addition, the image separation processing unit 143
In image area separation processing, edge judgment (judgment based on the continuity of white and black pixels), halftone dot judgment (judgment based on the repeating pattern of peak / valley peak pixels in the image), photo judgment (outside of characters / halftone dots) (If there is image data), the area of the character, the print (halftone dot) portion, and the photograph portion is determined and transmitted to the CPU 145.

The CPU 145 is the image separation processing unit 14
The determination result of No. 3 is used for switching parameters and coefficients in the RGB filter / color conversion processing block 144 and the printer γ correction / YMCK filter / gradation processing block 141 in the subsequent stage. RGB filter / color conversion processing block 144
Performs MTF correction, smoothing, edge enhancement, through, etc. of the image data of each color of R, G, B, and the filter coefficient thereof is switched and set by the CPU 145 according to the determination area.

Further, the RGB filter / color conversion processing block 144 converts the image data of each color of R, G, B into Y,
Converted to image data of each color of M, C, K, and UCR / UC
A processing is performed and the result is output to the scaling processing block 146. The scaling processing block 146 executes enlargement / reduction processing in the main scanning direction on the image data. The branching of the image data to the image display unit 48 is performed after the scaling processing of the scaling processing block 146, and the image data after the scaling processing of the scaling processing block 146 is sent to the image display unit 48 via the interfaces 147 and 148. Sent.

The create processing block 149 performs create editing and color processing on the image data input from the scaling processing block 146 via the interface 147. In create editing, italic, mirror, shadow, hollow processing, etc. To execute. In addition, the create processing block 149 executes color conversion, designated color deletion, undercolor processing, and the like in color processing.

The printer γ correction / YMCK filter / gradation processing block 141 is a create processing block 149.
The printer γ correction is performed on the image data after the process (1) and is passed through the YMCK filter, and the coefficients of the printer γ and the YMCK filter are set by the CPU 145 based on the determination area. Further, the printer γ correction / YMCK filter / gradation processing block 141 executes dither processing on the image data.

The video control block 150 is a printer γ correction / YMCK filter / gradation processing block 1.
41, write timing setting, image area, white area setting, gray scale,
A test pattern such as a color patch can be generated, and the final image data is output to the image writing unit 13. Each functional processing block 142-144, 146
To 150 are connected to the CPU 145,
A program 5 stored in the ROM 151 executes setting and operation of each process according to an instruction from the system control unit 47.

As described above, in this embodiment, a plurality of sheet feeding units 35 to 37 for sequentially feeding sheets and the sheet feeding unit 3 are provided.
5 to 37, a photosensitive drum 14 for forming an image on a sheet, a charger 23, an image writing unit 13, developing units 24 to 27, an intermediate transfer belt 28, a paper transfer unit 32, and a fixing unit 45. In the image forming apparatus having the image section, the push switches 125, 137, 138 as a recognition means for recognizing that the backing sheet is used when the backing sheet is set in the sheet feeding units 35 to 37, the backing sheet selection Since the lever 126, the pressing plate 127, and the image display unit 48 as a display unit that indicates the setting state of the backing paper when the recognition unit recognizes that the backing paper is used, the official document for image formation is provided. It is possible to prevent erroneous copying from occurring due to image forming errors caused by using the backing paper even though the backing paper cannot be used as a paper when creating It is possible.

The invention according to claim 1 can be similarly implemented even when the number of paper feeding units is one.

Further, in this embodiment, from the push switches 125, 137, 138, the backing sheet selection lever 126 and the pressing plate 127, the recognition means detects that the backing sheet has been set in the sheet feeding sections 35 to 37. Since the backing paper set detection means is composed of the above, the recognition means can be realized with a simple configuration. Since the backing paper set detection means is provided in the paper feeding unit, the user sets the backing paper in the paper feeding unit. At the same time, the backing paper set detection means can be set in the backing paper setting state by the backing paper selection lever, and the backing paper set detection means can be prevented from being set incorrectly.

Further, in this embodiment, the image forming unit forms an image on the paper from the paper feeding unit by the image signal processed by the image processing unit 11 as the image processing unit, and the paper feeding unit is selected. A plurality of paper feed units 35 that feed paper
To 37, the image processing means 11 includes a plurality of paper feeding units 35.
To 37, the processing conditions of the image signal are changed when the backing paper is set in the selected paper feeding unit, so that the density parameter of the scanner γ correction or the printer γ correction of the image processing means 11 is changed. Can reduce the adverse effects of the show-through of the paper. Further, when the image density is changed in a digital image forming apparatus such as a digital copying machine, the density parameter of the image processing means is changed and the image density is controlled by the image data. Therefore, the image density depends on the use environment. Is less.

Next, another embodiment of the present invention will be described. In this embodiment, the image processing unit 11 is the system control unit 47 in the above embodiment.
Instead of changing the image processing parameters of the look-up table so that the back side data is received from and the image density is shifted to the high density side (or the printer γ stands),
The sequence control unit 130 has push switches 125, 1
The image density is changed by receiving backing paper detection signals from 37 and 138 and changing process conditions.

When the sequence controller 130 receives a backing sheet detection signal from the push switches 125, 137 and 138 as shown in FIG. High voltage power source for applying developing bias and charger 23 composed of scorotron charger
Power source for applying an electric potential to the grid of the semiconductor laser 15
Laser driving circuit for driving the bias roller 2
By controlling at least one of 9, 30 and a power source for applying a transfer bias to the paper transfer bias roller 33, the developing bias to the developing units 24 to 27, the surface potential of the photosensitive drum 14, and the light emission of the semiconductor laser 15 are controlled. Power (LD
Power) and at least one of the process control conditions of the transfer bias to the bias roller 29 and the paper transfer bias roller 33 is switched to a value for the backing paper such that the image density is shifted toward the higher density side than the normal level.

In this embodiment, in the above-mentioned embodiment, the selected paper feed unit comprises a plurality of paper feed units 35 to 37 for feeding sheets, and the image forming units 14, 23, 1
A process for performing process control of 3, 24-27, 28, 32, 45, and changing the process control condition when the backing paper is set in the selected paper feeding unit of the plurality of paper feeding units 35-37. Sequence control unit 130 as control means
Since it is provided, the adverse effect due to the show-through of the sheet can be reduced. The invention described in claim 2 can be similarly applied to an analog image forming apparatus such as an analog copying machine.

The present invention is not limited to the above-described embodiments, and for example, analog copying machines, digital copying machines, facsimiles, color facsimiles, printers,
It can be applied to an image forming apparatus such as a color printer. Further, as the backing paper set detecting means, a means for automatically detecting the backing paper set in the paper feeding section can be used.

[0083]

As described above, according to the first aspect of the invention, a plurality of or one sheet feeding section for sequentially feeding sheets and an image is formed on the sheet fed from this sheet feeding section. In an image forming apparatus having an image forming unit, a recognition unit that recognizes that the backing paper is used when the backing paper is set in the paper feeding unit, and a recognition unit that recognizes that the backing paper is used. Since the display means for displaying the setting state of the backing paper is provided when it is recognized, the backing paper is used even if the backing paper cannot be used as a sheet when forming a formal document in image formation, and the image is formed. You can prevent mistakes before they happen.

Moreover, the image forming unit forms an image on the paper from the paper feeding unit by the image signal processed by the image processing means, and the paper feeding unit selects a plurality of papers for feeding the paper. The image processing means includes a paper feeding unit, and when the backing paper is set in the paper feeding unit selected from the plurality of paper feeding units, the image processing unit of the image signal shifts the image density to the high density side. Since the processing condition is changed, the adverse effect due to the show-through of the sheet can be reduced by changing the density parameter of the image processing means.

According to the second aspect of the present invention, a plurality of paper feed units that sequentially feed the selected paper, and an image forming unit that forms an image on the paper fed from the paper feed units. In an image forming apparatus having: a recognition unit that recognizes that the backing sheet is used when the backing sheet is set in the sheet feeding unit; and a recognition unit that recognizes that the backing sheet is used. When the backing paper is set in the selected paper feeding unit of the plurality of paper feeding units, the image density is usually Since the process control means that changes the process control conditions to shift to a higher density side is provided, the backing paper is used even when the backing paper cannot be used as the paper when forming a formal document in image formation. Before it causes an image formation error Gukoto can, it is possible to reduce the adverse effects of show-through of the paper.

[Brief description of drawings]

FIG. 1 is a block diagram showing a control system according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an outline of the embodiment.

FIG. 3 is a block diagram showing a control system of the embodiment.

FIG. 4 is a block diagram showing a circuit configuration of an image display unit in the embodiment.

FIG. 5 is a front view showing the image display unit of the embodiment.

FIG. 6 is a front view showing the operation unit according to the embodiment.

FIG. 7 is a front view showing a display example of the LCD panel in the embodiment.

FIG. 8 is a front view showing an example of screen development by pressing a double-sided key on the LCD panel in the embodiment.

FIG. 9 is a block diagram showing a touch panel detection circuit of a touch panel key in the embodiment example.

FIG. 10 is a diagram showing a relationship between a controller output signal and a state of each terminal of the touch panel key in the embodiment.

FIG. 11 is a block diagram showing a control system of the operation unit according to the embodiment.

FIG. 12 is a cross-sectional view showing a sheet feeding unit of the embodiment.

FIG. 13 is a perspective view showing a sheet feeding unit, a size detecting unit, and a back sheet detecting unit of the embodiment.

FIG. 14 is a front view showing a display example of the LCD panel of the embodiment.

FIG. 15 is a block diagram showing an image processing unit of the above-described embodiment.

[Explanation of symbols]

11 Image processing unit 13 Image writing unit 14 photoconductor drum 23 Charger 24-27 developing device 28 Intermediate transfer belt 32 paper transfer unit 45 fixing unit 46 Operation unit 47 System control unit 48 image display unit 48 35-37 Paper Feeding Section 125, 137, 138 push switch 126 Backing paper selection lever 127 pressing plate 130 Sequence control unit

Continuation of front page (56) Reference JP-A-7-125851 (JP, A) JP-A-5-88435 (JP, A) JP-A-3-73974 (JP, A) JP-A-8-248709 (JP , A) JP 62-141531 (JP, A) JP 9-11576 (JP, A) JP 8-137295 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G03G 21/00 370-540 G03G 15/00 303 G03G 15/00 510-534 G03G 15/00 106 H04N 1/00-1/00 108 B41J 13/00-13/32 B41J 29/00-29 / 70

Claims (2)

(57) [Claims] 1. An image forming apparatus having a plurality of or one sheet feeding section for sequentially feeding sheets and an image forming section for forming an image on the sheets fed from the sheet feeding section, A recognition means for recognizing that the backing paper is used when the backing paper is set on the set, and a display means for indicating the setting state of the backing paper when the recognition means recognizes that the backing paper is used And the image forming unit includes an image processed by the image processing means.
The image signal forms an image on the paper from the paper feed unit,
The paper feed section is the paper source that the selected one feeds paper.
And the image processing means includes a plurality of paper feed units.
If the backing paper is loaded in the selected paper source
Image signal processing so that the image density shifts to the high density side
An image forming apparatus characterized by changing conditions . 2. A plurality of selected sheets are sequentially fed.
Images on multiple sheets of paper and paper fed from this paper tray.
In an image forming apparatus having an image forming unit for forming,
Make sure the backing paper is used when it is set in the paper feed section.
And the recognition paper and the backing paper used by this recognition means.
Table showing the setting state of the backing paper when it is recognized that it will be used
Indicating means and process control of the image forming unit,
If the backing paper is loaded in the selected paper source
Image density shifts to higher density than normal
Process control means to change the process control conditions
Image type forming apparatus characterized by comprising.