JP2021054617A - Image forming device - Google Patents

Abstract

To suppress occurrence of a conveyance error during conveyance of a sheet, in a case where an image is once formed onto the sheet a part of which can be cut off like a sheet with perforation and image forming operation is repeatedly executed in a state where the part on which the image had been formed has been cut off.SOLUTION: An image forming device 1 capable of forming an image onto a sheet with perforation includes: a conveyance sensor 60 provided to a conveyance path; a controller 100 for instructing to stop sheet conveyance in accordance with detection of front and rear ends of a sheet by the conveyance sensor 60; and setting means 50 for setting the kind of the sheet and, when the sheet is the sheet with perforation, a position of a used region of the sheet with perforation. The controller 100 continues sheet conveyance regardless of a rear end detection result of the sensor 60 when it is determined that the used region of the sheet is located at a position overlapping with the conveyance sensor 60 in a width direction of the conveyance path based on the position of the used region of the sheet set by the setting means 50.SELECTED DRAWING: Figure 12

Description

The present invention relates to an image forming apparatus capable of performing image forming on a paper in which a part of an area is cut off.

Conventionally, in an image forming apparatus such as a copier or a printer, a transport sensor is arranged in the middle of a paper transport path in order to detect a paper transport state. The signal output from the transfer sensor is used for detecting a paper jam, for measuring the transfer timing of subsequent paper, and the like.

By the way, in recent years, electrophotographic image forming apparatus has come to be used in the printing field such as POD (Print on Demand), and it is also required to meet various needs related to special paper. Specific examples of special paper include binder paper and tab paper. When transporting these special papers, if the same transport control as for normal paper is performed using the detection result of the transport sensor, a problem may occur in an unexpected case.

Patent Document 1 proposes a method for solving a transport problem when transporting binder paper. The image forming apparatus of Patent Document 1 masks the paper detection result for a predetermined time from the detection of the paper tip in order to prevent the transport sensor from erroneously detecting the front and rear edges due to the influence of the punch holes of the binder paper. ..

Further, Patent Document 2 proposes a method for solving a transport problem when transporting tab paper. In the image forming apparatus of Patent Document 2, when the tab portion of the tab paper is present at the position of the transport sensor, the paper jam determination range when transporting the tab paper is set wider than that of the standard size paper.

Japanese Unexamined Patent Publication No. 7-69480 Japanese Unexamined Patent Publication No. 2004-99233

In recent years, there is also a need to form an image on a paper that has been perforated and can be separated along the perforated portion (hereinafter referred to as "perforated paper" or "perforated paper"). As shown in FIG. 13, the perforated paper may perform image formation in a state where the used area is cut off. In such a case, the methods of Patent Document 1 and Patent Document 2 are insufficient to solve the transport problem.

The perforated paper of FIG. 13 is a paper capable of dividing A4 size (210 mm × 297 mm) paper into nine, and two of them are used and cut out. When transporting perforated paper from which a part of the area has been cut out in this way, the length in the transport direction is not uniform, so depending on the position of the transport sensor and the position of the used area from which the perforated paper has been cut off. , The length of the paper in the transport direction cannot be measured correctly.

A specific example will be given. FIG. 14A is a diagram showing a transport state of perforated paper from which a part of the region is cut off, and is a diagram in which a transport sensor detection region is attached to the paper of FIG. In the example of FIG. 13, the transport sensor detects the paper length (198 mm) for two sides in the transport direction, but the actual paper length is for three sides (297 mm), and the detection size and the actual paper length. The paper size is different. FIG. 14B is a diagram showing a problem based on the detection signal of the transport sensor. The paper passing time derived from the detection signal (solid line in the graph) of the transport sensor does not match the paper passing time set by the controller (dotted line in the graph). Therefore, a transport error occurs. As described above, the length of the paper in the transport direction cannot be appropriately measured depending on the position of the transport sensor and the position of the used area cut out from the perforated paper. Note that FIG. 15 (a) shows an example of the state of the perforated paper in which the above-mentioned problem occurs, and FIG. 15 (b) shows a paper in which a part of the perforated paper is cut off but the above-mentioned problem does not occur. This is an example of a state.

In view of the above problems, it is an object of the present invention to suitably perform paper transport in an image forming apparatus for transporting paper used by cutting out a part of the region.

In order to achieve the above object, the image forming apparatus according to the present invention is an image forming apparatus capable of forming an image on a paper used by cutting out a part of a region, and transports the paper. A transport path for forming an image on the paper transported along the transport path, and a front end and a rear end of the paper arranged in the transport path and being transported are detected. Paper detection means for the purpose, acquisition means for acquiring information indicating the position of the used area which is a cut area on the paper, information indicating the position of the used area acquired by the acquisition means, and the above. It has a control means for controlling the paper transport of the transport means based on the information output from the paper detection means, and the control means has a used area of the cut out paper of the transport path. When it is determined that the paper is located at a position that does not overlap with the detection area of the paper detecting means in the width direction, the paper transport is continued and stopped according to the timing when the front end and the rear end of the paper are detected by the paper transport means. When it is determined that the cut-out used area of the paper is at a position overlapping the paper detecting means in the width direction, the timing at which the rear end of the paper is detected by the paper detecting means is determined. Instead, the paper is continuously conveyed.

According to the present invention, a paper passing problem occurs in a case where a paper capable of separating a part of the paper such as a perforated paper is used once and the image forming operation is repeatedly executed with the used part cut off. It is possible to provide an image forming apparatus without increasing the cost.

Cross-sectional view of the image forming apparatus Controller block diagram Block diagram of image formation control unit Flowchart showing printing operation Diagram showing the print item setting screen Diagram showing the paper setting screen The figure which shows the output signal example of a transport sensor Flowchart showing normal paper transport operation Flowchart showing selection control of paper transport The figure which shows the example of the presence / absence judgment processing of the used surface of the transport sensor position The figure which shows the example of the output signal value at the time of transport control of special paper Flowchart showing paper transport operation at special times The figure which shows the state example of the perforation paper Diagram explaining the problem The figure which shows the state example of the perforation paper which was cut out partly

Hereinafter, preferred embodiments of the present invention will be described in detail exemplarily with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the following embodiments should be appropriately changed depending on the configuration of the apparatus to which the present invention is applied and various conditions. Therefore, unless otherwise specified, the scope of the present invention is not intended to be limited to them.

(Embodiment 1)
[Image forming device]
FIG. 1 is a cross-sectional view of the image forming apparatus 1. The image forming apparatus 1 forms an image in the image forming unit 10 using an electrophotographic process, transfers the formed image to the paper P in the secondary transfer unit, and heats the paper P to which the image is transferred in the fixing unit. This is a device for fixing an image on paper P. The image forming apparatus 1 described in this embodiment is a four-color full-color multifunction printer (color image forming apparatus) using an A4 size electrophotographic process. The A4 size system referred to here refers to a paper that passes A4 size paper in vertical feed. The vertical feed referred to here means that the long side of the paper P is set in the transport direction and the short side is set in the width direction orthogonal to the transport direction. The image forming apparatus 1 may be a monochrome multifunction printer or a single function printer. The paper P is a paper on which an image is formed on the surface thereof. The paper P is, for example, plain paper, thick paper, OHP, coated paper, label paper, binder paper, tab paper, perforated paper, or the like.

The image forming apparatus 1 includes a controller 100 that controls image forming. The controller 100 functions as a control unit and plays a role of executing an image forming operation based on an input print information signal (for example, image data, paper information, etc.).

The image forming apparatus 1 forms a multicolor image by superimposing four color developing agents (hereinafter, referred to as toner) of yellow (Y), magenta (M), cyan (C), and black (K). To do. Therefore, an image forming unit 10 for forming a toner image of each color is provided. Although YMCK is added to the suffix of the reference code in FIG. 1, the basic configuration of the image forming unit 10 of each color is the same. In the specification, this suffix is omitted in the case of the description that applies to the image forming unit 10 of all colors. The image forming unit 10 has a rotating drum type photoconductor 11 (hereinafter referred to as a drum 11) as an image carrier on which an image is formed, and further, a cleaning member (not shown) acting on the drum 11 and a charging roller. 12. It has a developing unit 14. Toners of each color are stored in the toner storage chamber of the developing unit 14.

A laser scanner unit 13 as an exposure means for the drum 11 is arranged near the image forming unit 10, and a cassette 2 for storing the paper P is arranged at the lower part. Further, a transfer belt unit 20 (hereinafter referred to as a transfer unit) is provided on the upper side of the image forming unit 10.

The transfer unit 20 has an intermediate transfer belt 21 and a drive roller 22 for driving the intermediate transfer belt 21. Inside the intermediate transfer belt 21, four first to fourth primary transfer rollers 15 are arranged in parallel. Each primary transfer roller 15 is arranged so as to face the drum 11 of each image forming portion.

The upper surface of the drum 11 of each color of the image forming portion 10 is in contact with the lower surface of the intermediate transfer belt 21 at the position of each primary transfer roller 15. This contact portion is called a primary transfer portion.

The drive roller 22 is a roller that rotationally drives the intermediate transfer belt 21, and a secondary transfer roller 25 is arranged outside the portion of the intermediate transfer belt 21 backed up by the drive roller 22. The intermediate transfer belt 21 is in contact with the secondary transfer roller 25 which is a transfer means, and this contact portion is called a secondary transfer portion. The intermediate transfer belt cleaning device 23 is arranged on the outside of the portion of the intermediate transfer belt 21 backed up by the tension roller.

The image forming apparatus 1 is provided with a paper transport path Q (wavy line portion in the drawing) for transporting the paper P fed from the cassette 2 upward. In the paper transport path Q, the feed roller 3 and the separation roller pair 4, the resist roller pair 5, the secondary transfer roller 25, the fixing unit 30, and the discharge roller pair (not shown) are arranged in this order from the upstream. Transport P to the discharge tray 9.

The image forming apparatus 1 has an image reader 40. The image reader 40 has a function of reading an image of a document with an optical sensor and converting it into an image signal. The image reader 40 is equipped with a document feeding unit 41. The document feeding unit 41 feeds the documents set upward on the document tray 42 one by one in order from the first page. The reader scanner 43 reads the image of the document fed by the document feeding unit 41. The reader scanner 43 includes a light irradiation unit (not shown) and an image sensor (not shown), and converts a document into an image signal by forming an image on the image pickup surface of the image sensor. Since the reader scanner 43 extends in the main scanning direction (direction orthogonal to the document transport direction), the image of the entire page can be read by transporting the document.

When reading a document without using the document feeding section 41, first, the document feeding section 41 is lifted by the user, the document is placed on the platen glass 45, and the reader scanner 43 is scanned from left to right. This allows the document to be read.

[Main control unit]
FIG. 2 is a block diagram of a controller 100 that controls the image forming apparatus 1. As shown in FIG. 2, the controller 100 has a CPU circuit unit 101. The CPU circuit unit 101 incorporates a CPU (not shown), a ROM 102, and a RAM 103, and comprehensively controls each block (104, 105, 106, 107, 108, 109) described later by a control program stored in the ROM 102. To do. The RAM 103 temporarily holds control data and is also used as a work area for arithmetic processing. The controller 100 is electrically connected to an external information terminal such as a personal computer 200, an input device such as an image reader 40, an operation panel 50, and the like, and transmits and receives signal information. The controller 100 executes an image forming operation based on a print information signal (for example, image data, paper information, etc.) input from the input device.

In the document feeding control unit 107, the document feeding unit 41 controls the document feeding operation and the document feeding operation. The image reader control unit 106 controls the operation of the reader scanner 43 and the conversion operation into an analog image signal. The image signal control unit 105 controls the operation of image processing the analog image signal converted by the reader scanner 43. Specifically, it means that image processing is performed after converting to a digital image signal, and the digital signal after image processing is converted into a video signal and output to the image formation control unit 104. Further, the image signal control unit 105 also controls an operation of performing image processing on a digital image signal input from the computer 200 via the external I / F 109. The image formation control unit 104 controls the components involved in the image formation operation based on the input video signal (detailed description of the image formation control will be described later). The operation display unit control unit 108 exchanges information between the operation display unit 50 and the CPU circuit unit 101. The operation display unit 50 outputs a key signal corresponding to the operation of each key to the CPU circuit unit 101, and displays the corresponding information on the display unit based on the signal from the CPU circuit unit 101.

[Image formation control]
When the image forming apparatus 1 performs an image forming operation, the image forming control unit 104 controls each component involved in the image forming operation to form a full-color image on the paper P.

FIG. 3 is a block diagram of the image formation control unit 104. The image formation control unit 104 has a CPU circuit unit 151 that is different from the controller 100. The CPU circuit unit 151 incorporates a ROM 152 and a RAM 153, and controls each component (12, 13, 14, 15, 22, 25, 30) involved in image formation by an image formation control program stored in the ROM 152. The RAM 153 temporarily stores each detection data for controlling the image formation process, and uses it as a work area for arithmetic processing associated with the control.

Subsequently, the image formation process will be described below. First, the image formation control unit 104 starts rotating and driving the drum 11 in the image formation unit 10 and the drive roller 22 in the transfer unit 20 at a predetermined speed in accordance with the image formation timing. Specifically, the drum 11 is rotated in the clockwise direction in the drawing, and the intermediate transfer belt 21 is rotated in the forward direction with respect to the rotation direction of the drum 11 (counterclockwise in the drawing) with respect to the drive roller 22. Rotate.

Next, the image forming unit 10 executes operation control for developing an image on the drum 11 of each color. The details are as follows. First, the charging roller 12 uniformly charges the surface of the drum 11 with a predetermined potential and polarity. Next, the laser scanner unit 13 scans and exposes the surface of the drum 11 using a laser beam modulated according to the image information signals of each color of Y, M, C, and K to form an electrostatic latent image of each color. To do. Next, the toner is electrostatically adhered to the electrostatic latent image formed by the developing unit 14 to develop the toner image on the drum 11.

Next, the operation control of superimposing the toner images formed on the drums 11 of each color on the intermediate transfer belt 21 is executed. The details are as follows: a predetermined potential is applied to the primary transfer roller 15 facing the drum 11 via the intermediate transfer belt 21, and the toner image on the drum 11 is electrostatically transferred onto the intermediate transfer belt 21 in the primary transfer unit. Let me. By executing this operation for each color, a full-color (Y color + M color + C color + K color) toner image is formed on the intermediate transfer belt 21. This toner image is carried to the secondary transfer unit by the rotational drive of the drive roller 22. The toner that cannot be transferred onto the intermediate belt 21 by the primary transfer unit and remains on the drum 11 is cleaned by a cleaning member (not shown).

On the other hand, the operation of feeding paper from the cassette 2 is executed in parallel with the operation of forming the toner image on the intermediate transfer belt 21. As for the details, one sheet of paper P is fed by the feeding roller 3 and the separating roller pair 4 according to the image formation timing, and is conveyed to the resist roller pair 5. After that, the paper P is conveyed to the secondary transfer unit in synchronization with the toner image on the intermediate transfer belt 21.

Next, the operation control for transferring the toner image on the intermediate transfer belt 21 onto the paper P is executed. The details are as follows: At the timing when the toner image and the paper P are conveyed to the secondary transfer unit, a secondary transfer bias having a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 25, and the toner image is intermediate. It is electrostatically transferred from the transfer belt 21 to the paper P (secondary transfer). That is, the toner image is transferred to the entire surface of the paper P by sandwiching and transporting the paper P by the secondary transfer unit. The paper P on which the toner image is transferred is conveyed to the fixing unit 30. The toner that cannot be transferred onto the paper P by the secondary transfer unit and remains on the intermediate transfer belt 21 is cleaned by the belt cleaning member 23.

After the secondary transfer, the fixing unit 30 executes operation control for heating and pressurizing the toner image on the paper P. When the fixing unit 30 receives a printing operation request, the temperature is raised to a temperature required for toner fixing, and then the operation is controlled so that the temperature is maintained until the paper P reaches the fixing unit 30. .. The toner image on the paper P is heated and pressurized by the fixing nip portion (not shown) of the fixing unit 30 to permanently fix the toner image, and the paper P is sandwiched and conveyed to the fixing nip portion to be conveyed to the paper ejection tray. Transport up to 9.

[Printing procedure]
FIG. 4 is a flowchart showing a process in which the computer 200 transmits print information to the image forming apparatus 1 in response to a user's print request. Here, a case where image data created by using an application installed on the computer 200 is printed (hereinafter referred to as a print operation) will be described as an example. However, the present invention is not limited to the printing operation described here, and can also be applied to a copying operation for duplicating a document. The above-mentioned print information includes print items such as a paper type, a print surface, a number of copies to be printed, a paper feed method, and image allocation information, in addition to image data to be printed.

When the user requests printing of image data via the application program, the application issues a printing request to the printer driver. This request is not always issued directly by the application to the printer driver, but may also be issued to the printer driver through the interface provided by the application's operating system. With this print request, the print processing procedure by the printer driver is started. Proceeding to step S101, the printer driver displays a screen prompting the setting of print items (hereinafter, print item setting screen). The print items that can be set include a function for setting the allocation of image data as well as the type of paper and the paper feeding method. When the setting of the print item is completed, the process proceeds to step S102, and the printer driver creates print information based on the set print item. Then, the process proceeds to step S103, and the created print information is transmitted to the image forming apparatus 1.

FIG. 5 is a setting screen 300 for causing the user to set print items in step S101 of FIG. The setting screen 300 has setting items of a printed matter layout display 301, a “copy” text box 302, a “page” radio button 303, 304, a “start” text box 305, and an “end” text box 306. The setting screen 300 also has a "original size" pull-down menu 307, an "output size" pull-down menu 308, and a "color mode" pull-down menu 309. The setting screen 300 also has a "paper type" pull-down menu 310, a "detailed setting of paper type" button 311, a "paper feed method" pull-down menu 312, and an "image allocation" radio button 313, 314. The setting screen 300 also has a "assignment designation" pull-down menu 315, a "print" button 316, and a "cancel" button 317.

The following values are set for each item of the setting screen 300. The number of copies to be output of the printed matter is set in the item of the "number of copies" text box 302. A print page range is set for the items of the "Page" radio buttons 303 and 304 and the "Start" text box 305 and "End" text box 306. When the "all pages" radio button 303 is selected, all pages of user-created data are set as print page ranges. On the other hand, when the "specify page" radio button 304 is selected, the values entered in the "start" text box 305 and the "end" text box 306 are set as the print page range. A size for one page of image data is set in the item of the "original size" pull-down menu 307, and a standard size such as "A4" or "LTR" can be selected. The size of the printing paper is set in the item of the "output size" pull-down menu 308, and a standard size such as "same as the original size" or "A4" or "LTR" can be selected. A print color mode is set in the item of the pull-down menu 309 of the "color mode", and can be selected from "automatic (color / black and white)", "color", and "black and white".

The “Paper Type” pull-down menu 307 is an item for setting the type of paper used for image formation. In this embodiment, any one of plain paper, thin paper, thick paper, woodfree paper, glossy paper, postcard, glossy film, photo card, T-shirt transfer paper, back print film, OHP film, envelope, label paper, and perforated paper is used. Set.

The perforated paper is a paper that has been perforated in advance and can be separated along the perforated portion. In the present embodiment, the perforated paper is an example of paper that is partially cut out and used.

The "Detailed setting of paper type" button 311 is used to set the details of the paper type. For example, it is used when setting the number of divided surfaces of the perforated paper. When this button is pressed, the paper setting screen 350 described later is displayed, and detailed paper settings can be made. The item selected in the "Paper feed method" pull-down menu 312 is set as the paper feed method for the paper to be output by the image forming apparatus 1, and any one of "automatic", "cassette", and "manual feed" is set. Is possible. Items selected by the "image allocation" radio buttons 313 and 314 can be set for a method of allocating image data on paper. When the "automatic" button 313 is selected, the controller 100 automatically allocates from the paper information and the image data. When the "designate" button 314 is selected, the "assignment designation" pull-down menu 315 can be set. For the allocation setting, for example, "1in1", "2in1", "customization (selected on the layout)" and the like can be selected. Further, as a special case, as a setting method when allocating to perforated paper as described in the print layout 301, the allocation position of the image can be specified by clicking the print area of the paper on the print layout 301. It is possible. The allocation set here is displayed on the print layout 301. The above print items are stored in the hard disk (not shown) together with the image data to be printed as items constituting one print job. When the "print" button 316 is pressed, the printer driver generates print information based on the image data and the paper settings set via the screens of FIGS. 5 and 6. After that, the printer driver transmits the generated print information to the image forming apparatus 1. When the "Cancel" button 317 is pressed, the printer driver closes this screen and ends the process.

[Paper settings]
The paper settings will be described in detail. In the present embodiment, a method will be described in which a user presses the "Detailed setting of paper type" button 311 on the printer driver described above, and selects and inputs information required for setting items on the displayed paper setting screen 350. However, the paper setting method is not limited to this method. For example, the image reader 40 may be operated on the operation display unit 50, and the paper information described later may be acquired and automatically set by scanning with the image reader 40.

FIG. 6 is an example of the paper setting screen 350. The paper setting screen 350 has a "paper layout" field 351 and a "paper type" pull-down menu 352, and a "paper size" radio button 353 and 354. The paper setting screen 350 also has a "standard size" pull-down menu 355, an irregular size "length" text box 356 and a "width" text box 357, and a "margin presence / absence" radio button 358, 359. The paper setting screen 350 also has a "front end" text box 360, a "rear end" text box 361, a "left end" text box 362, and a "right end" text box 363. The paper setting screen 350 also has a "number of divided faces" text box 364, a "divided pattern" radio button 365, 366, 376, a "length direction" text box 368 and a "width direction" text box 369 of the same size division. .. The paper setting screen 350 also has a "delivery note / label" pull-down menu 370, a "used side" radio buttons 371 and 372, an "yes" text box 373, an "OK" button 374, and a "cancel" button 375.

The following values are set for each setting item on the setting screen 350. When the setting is input for each item, it is reflected in the paper layout 351. In the present embodiment, the perforation paper shown in FIG. 14 (9-divided A4 size perforation paper) will be described as an example. The items selected in the "Paper Type" pull-down menu 352 reflect the items input in the "Paper Type" pull-down menu 310 in the print item setting screen 300 described above, and are output by the image forming apparatus 1. Is set as the type of. In FIG. 6, this item is set as "perforation paper". The item selected by the "paper size" radio buttons 353 and 354 is set as the outer size of the paper. When "standard size" is selected, the "standard size" pull-down menu 355 can be set, and a standard size such as "A4" or "LTR" can be selected. When "Amorphous size" is selected, values can be entered in the "Length" text box 356 and the "Width" text box 357 of the amorphous size. In the irregular size "Length" text box 356, enter the length of the side parallel to the paper transport direction, and in the "Width" text box 357, enter the length of the side orthogonal to the paper transport direction. You can set the paper size by doing this. In FIG. 6, the standard size is selected and "A4" is set. The item selected by the "presence / absence of margin" radio button 358, 359 is an item for setting whether or not there is a margin on the paper to be used. When "None" is selected, all of the "tip" text box 360, the "rear end" text box 361, the "left end" text box 362, and the "right end" text box 363 are displayed as "0". When "Yes" is selected, predetermined values can be set in each of the "tip" text box 360, the "rear end" text box 361, the "left end" text box 362, and the "right end" text box 363. In FIG. 6, "None" is selected. Therefore, "0" is displayed in all of the "tip" text box 360, the "rear end" text box 361, the "left end" text box 362, and the "right end" text box 363. The “number of divided faces” text box 364 is an item for setting the number of divided faces by the perforation R. In the standard setting, "1" is entered in the "number of divided faces" text box 364, but the number of divided sheets can be set by entering a numerical value in the "number of divided faces" text box 364. The "divided pattern" radio buttons 365, 366, and 376 are items that can be selected when a numerical value of "2" or more is input in the "number of divided surfaces" text box 364, and are items to be selected with the radio buttons. Sets the size to divide. When "same size division" is selected, it is possible to input the "length direction" text box 368 and the "width direction" text box 369 of the same size division, respectively. In the "length direction" text box 368, enter the number of divided sides of the sides parallel to the paper transport direction, and in the "width direction" text box 369, enter the number of divided sides of the sides orthogonal to the paper transport direction. By doing so, the division pattern of the entire paper can be set. When "Delivery note / label" is selected, it is possible to set the "Delivery note / label" text box 370, and it is set by selecting the default size such as "EAIJ standard" and "D label". It is possible to do. When "Other (Customize: Set on layout)" is selected, the position of the perforation R can be freely set by moving the perforation R on the paper layout 351. In FIG. 6, by inputting "3" in the "vertical" text box 367 and "3" in the "horizontal" text box 368 for "same size division", a perforation paper divided into 9 parts of the same size is set. ing.

The item selected by the "used surface" radio buttons 371 and 371 is an item for setting the position of the used area which is the area cut out in the perforation paper. First, it is set whether or not the paper has a used (cut out) surface. When "None" is selected, it is set that there is no used surface. When "Yes" is selected, a numerical value can be entered in the "Yes" text box 373, and the number of used areas can be set. Further, when "Yes" is selected, the position of the used area can be set on the paper layout 351. The setting method sets the position of the used side by selecting the used print side on the paper layout displayed in the "paper layout" field 351. In the case of FIG. 6, "Yes" is selected and "2" is entered in the text box 373. Further, the used surface position is set to the surface at the rear right position (367 in the figure).

When the "OK" button 374 is pressed after setting the above items, the set paper information is confirmed, the confirmed paper information is stored in the hard disk (not shown), and the paper setting screen 350 is closed. When the "Cancel" button 375 is pressed, the paper setting screen 350 is closed and then the print setting screen 300 is returned. However, in this case, the paper setting items set up to that point are discarded without being saved.

[Paper transport control]
Here, normal paper transport control (general paper) will be described. The paper transport control referred to here is a control for confirming that the paper transport is normal by determining whether or not the paper length (transfer length) through which the paper is being passed is the same as the set paper length. .. If the setting and the detection result are different, the transport is stopped and the image forming operation is stopped.

The detection of the length of the paper to be passed is executed based on the output signal of the paper transport sensor 60, which is the paper detection means arranged on the paper transport path Q. In the present embodiment, the transport sensor 60 arranged in the vicinity of the register roller pair, which is an example of the transport means, will be described as an example of the paper detection means. However, the present invention is not limited to this. For example, a paper feed sensor, a paper discharge sensor, a loop sensor, a fixing front / rear sensor, a paper discharge sensor, a double-sided transport sensor, etc. may be used as long as they are arranged on the paper transport path path Q and detect the paper transport state.

FIG. 7A is an example of the output signal value of the transport sensor 60. The graph of FIG. 7A is an example of the output signal value of the transport sensor 60 at the position of the shaded portion in FIG. 7B. This output signal value is represented by 1 bit, and when the output value is "0", it means "without paper", and when it is "1", it means "with paper". More specifically, the timing at which the output signal value of the transport sensor 60 transitions from "0" to "1", that is, the timing at which the output signal value changes from "without paper" to "with paper" represents the tip of the paper, and the output value is ". The timing of transition from "1" to "0" represents the rear edge of the paper. The image formation control unit 104 measures the time when the output signal value of the transport sensor 60 is "1", and temporarily stores the measurement result in the RAM 153 in the image formation control unit 104.

On the other hand, the controller 100 calculates in advance the time α for the paper to pass through the transport sensor 60 based on the paper size information (355 or 356 copies in FIG. 6) set in the paper setting operation and the transport speed. Notify the image formation control unit 104. To give a specific calculation example, when the A4 size is set, it is assumed that the transport length is 297 mm and the transport speed of the image forming apparatus 1 of the present embodiment is 105 mm / sec. The time to pass through is calculated to be 2.8 seconds.

When the calculated transit time result α and the transfer time β calculated from the output result of the transfer sensor 60 substantially match with each other in consideration of the detection variation of the transfer sensor 60, the image formation control unit 104 transfers the paper. Is judged to be normal, and instructions are given to continue paper transport. On the other hand, if they do not match, the image formation control unit 104 determines that there is an abnormality and instructs to stop the paper transport.

FIG. 8 is a flowchart for explaining normal paper transport control. In step S201, the controller 100 calculates the paper passing time (symbol: Tp) based on the paper information and the conveying speed. The calculation method of this transit time is as described above. Next, the controller 100 temporarily stores the calculated transit time information in the RAM 153, and proceeds to the next step S202.

The process from step S202 to step S206 is a process of measuring the transit time (symbol: Ts) from the output signal value of the transport sensor 60. The method of measuring the passing time from the output of the sensor referred to here is realized by counting the time of the output signal value "1" (signal value indicating "with paper") state of the transport sensor 60 with a timer.

In step S202, the image formation control unit 104 detects the paper tip from the output signal value of the transport sensor 60. Specifically, the tip of the paper is detected from the output signal value of the transport sensor 60 by the above-mentioned method. When the leading edge of the paper is detected, in step S203, a timer for measuring the “with paper” time is started, and the process continues to count up until the trailing edge of the paper is detected.

In step S204, the image formation control unit 104 detects the rear edge of the paper from the output signal value of the transport sensor 60. The rear edge of the paper is detected from the output value of the transport sensor 60 by the above-mentioned method. When the rear edge of the paper is detected, step S205 is executed.

In step S205, the image formation control unit 104 stops the timer for measuring the time of "with paper". When this process is completed and the measured transit time Ts is stored in the RAM 153, the process proceeds to step S206.

In step S206, the image formation control unit 104 determines whether or not the two match based on the passage time Tp calculated by the controller 100 stored in the RAM 153 and the passage time Ts measured from the output signal value of the transfer sensor 60. It is a process. If both are in agreement (YES) in this determination process, it is determined that the paper transport is normal, and the continuation of the paper transport is instructed (step S207). If they do not match (NO), it is determined that the paper transport is abnormal, and an instruction to stop the paper transport is instructed (step S208). When the processes of steps S207 and S208 are completed, the paper transport control is terminated.

[Paper transport selection flow]
Subsequently, the selection process of the paper transport control, which is a feature of the present embodiment, will be described. This flowchart is a flowchart executed by the image forming apparatus 1, and is executed when print information is received.

In step S301, the image formation control unit 104 acquires the paper information included in the received print information (items shown in FIG. 4). The paper information acquired here includes information on the paper type set via the setting screens of FIGS. 5 and 6, the presence / absence of a used area in the case of perforated paper, and the position of the used area. Etc. are included. Next, in step S302, the image formation control unit 104 determines whether the type of paper used for image formation is perforated paper or the used area when it is perforated paper, based on the acquired paper information. Determine if there is. Specifically, on the setting screen of FIG. 4, when the "paper type" is "perforated paper" and the "yes" radio button 372 is selected in the "used surface" item, the step. Move to S303. On the other hand, when the "paper type" is other than "perforated paper", or when the "paper type" is "perforated paper" but the "used side" item is selected, the "none" radio button 371 is selected. If so, the process proceeds to step S306.

Step S303 is a process of determining whether or not the used area (used surface) is at a position overlapping with the transport sensor 60 in the width direction of the paper. The details will be described with reference to FIG. The paper shown in FIG. 10 is the paper mentioned in the example of the problem (FIG. 13). For this paper, it is determined whether or not there is a used surface (used area) in the detection area A surrounded by the thick wavy line frame. The thick wavy line frame has a predetermined width at the center of the paper so as to cover a plurality of transfer sensor 60 positions (center positions in the lateral direction of the paper), and is further set by the length of the paper to be conveyed. Specifically shown in FIG. 10, a range (detection area) created with a width of 10 mm × 297 mm is set. If there is a used surface in the detection area indicated by the thick wavy line frame, the process proceeds to step S304, and if there is no used surface in the detection area, the process proceeds to step S305.

If YES is determined in S303, that is, if there is a used surface at a position overlapping the detection area of the transport sensor 60 in the width direction of the paper, the process proceeds to step S304, and the controller 100 controls the transport of special paper. select. The paper transport control in this process will be described in detail in [Special Paper Transport Control] described later. When the special paper transport control is completed, the processing of the flowchart of FIG. 9 is completed.

If NO is determined in S303, that is, if there is a used surface at a position that does not overlap the detection area of the transfer sensor 60 in the width direction of the paper, the process proceeds to step S305, and the controller 100 controls the transfer of normal paper. Select. The paper transport control in this process is the process of the flowchart of FIG. 8 described above. When the normal paper transport control is completed, the processing of the flowchart of FIG. 9 is completed.

[Special paper transport control]
The special paper transport control is a paper transport control executed when there is a used area of perforated paper at a position overlapping the detection area of the transport sensor 60 in the width direction of the paper, and is the process of S304 in the flowchart of FIG. Is. First, the outline of this control will be described with reference to FIG. FIG. 11B is a 1-bit electric signal value used for transport control of special paper. As described above, if the paper transfer control is executed only by the output signal value of the transfer sensor 60, a transfer problem may occur. Therefore, in this control, the output signal value after the output signal value indicating the paper tip of the transport sensor 60 is ignored, and the paper transport control is executed with the signal value pseudo-generated inside the image formation control unit 104.

FIG. 12 is a flowchart illustrating transfer control of special paper. This flowchart is executed when it is determined in the determination of step S303 in the above-mentioned control that the used area of the perforation paper is located at a position overlapping the detection area of the transport sensor 60. After that, all the controls in steps S401 to S409 are executed by the image formation control unit 104.

In S401, the image formation control unit 104 sets the transit time A calculated by the controller 100 as the transport time (symbol: Tc). Specifically, the above-mentioned 2.8 seconds is set as the transport time Tc = 2.8 seconds. When this process is completed, the process proceeds to step S402.

In step S402, the image formation control unit 104 detects the paper tip from the output signal value of the transport sensor 60. Specifically, the tip of the paper is detected from the output signal value of the transport sensor 60 by the above-mentioned method. When the tip of the paper is detected, the process of step S403 is executed.

In step S403, the image formation control unit 104 ignores the output signal value from the transport sensor 60, generates an electric signal value (bit = 1) that pseudo indicates “with paper” by internal processing, and “paper”. It is a process to make it in the "Yes" state. The process proceeds to the next step S404 at the timing when the image formation control unit 104 generates an electric signal value (bit = 1) indicating “with paper”.

Steps S404 to S407 are processes for measuring the timing of generating an electric signal value indicating "no paper" in a pseudo manner. In addition, the state of "with paper" is maintained in a pseudo manner until an electric signal value indicating "without paper" is generated.

In step S404, it is a process of starting the count-up timer. In this process, the timing at which the count-up timer is started is defined as the count time (symbol: t) = 0.

After that, in steps S405 and S406, the count-up is continued until the count time t becomes the transport time Tc. In step S405, it is a process of determining whether or not the count time t is equal to or longer than the transfer time Tc. If the count time t is less than the transfer time Tc, the process proceeds to step S406, and the count time is increased by 100 msec. Advance time. That is, the count-up process is executed by repeating the processes of step S405 and step S406. When the count time t becomes equal to or longer than the transport time Tc, the process proceeds to step S407, the count-up timer is stopped, and the process shifts to step S408.

Step S408 is a process in which the image formation control unit 104 generates an electric signal value (bit = 0) that pseudo indicates “no paper” by internal processing, and puts the state in the “no paper” state. The process proceeds to the next step S409 at the timing when the image formation control unit 104 generates an electric signal value indicating “no paper”.

Step S409 is a process for determining to continue the paper transport control with the pseudo “paper available” signal value generated in steps S401 to S408. When this process is completed, the special paper transport control is terminated.

As described above, according to the present embodiment, when a paper that can be used by separating a part of the paper such as a perforated paper is repeatedly subjected to an image forming operation with the used part cut out, a paper passing defect occurs. There is nothing to do. Further, since it is not necessary to arrange a plurality of transport sensors in the width direction of the paper, it is possible to provide an image forming apparatus that does not increase the cost.

1 Image forming device 2 Cassette 3 Paper feed roller 4 Separation roller vs. 5 Registrar roller vs. 6 Manual feed tray 7 Manual paper feed roller 8 Separation roller vs. 9 Paper discharge tray 10 Image forming unit 11 Photosensitive drum 12 Charging roller 13 Laser scanner unit 14 Development unit 15 Primary transfer roller 20 Transfer unit 21 Intermediate transfer Intermediate transfer belt 22 Drive roller 23 Intermediate transfer belt cleaning device 24 Recovery toner box 25 Secondary transfer roller 30 Fixing unit 40 Image reader 41 Document feeder 42 Document tray 43 Reader scanner 44 Document Paper output tray 45 Platen glass 50 Operation display unit 60 Conveyance sensor 100 Controller 101 CPU circuit unit 102 ROM
103 RAM
104 Image formation control unit 105 Image signal control unit 106 Image reader control unit 107 Document feed control unit 108 Operation display unit control unit 109 External interface 151 CPU circuit unit 152 ROM
153 RAM
200 Computer 300 Print setting screen 350 Paper setting screen

Claims (6)

An image forming apparatus capable of forming an image on paper used by cutting out a part of the area.
A transport means for transporting the paper along a transport path, and
An image forming means for forming an image on the paper conveyed by the conveying means, and an image forming means.
A paper detecting means for detecting the front end and the rear end of the paper which is arranged in the transport path and is being conveyed, and
An acquisition means for acquiring information indicating the position of a used area, which is a cut area on the paper, and
A control means for controlling the paper transport of the transport means based on the information indicating the position of the used area acquired by the acquisition means and the information output from the paper detection means.
Have,
When the control means determines that the cut-out used area of the paper is at a position that does not overlap the detection area of the paper detection means in the width direction of the transport path, the paper detection means causes the tip of the paper. According to the timing at which the rear end is detected, the continuation and stop of the transport of the paper are controlled, and the cut-out used area of the paper overlaps with the detection area of the paper detection means in the width direction. An image forming apparatus characterized in that, when it is determined that the paper is present, the paper is continuously conveyed regardless of the result of the paper detection by the paper detecting means. The image forming apparatus according to claim 1, wherein the paper is perforated and can be separated along the perforated portion. When the control means determines that the used area of the paper is at a position overlapping the detection area of the paper detection means in the width direction, an output signal indicating that the rear end of the paper detection means has been detected. The image forming apparatus according to claim 1 or 2, wherein the image forming apparatus is ignored. When the control means determines that the used area of the paper is at a position overlapping the detection area of the paper detection means in the width direction, the control means pseudo-signals a signal value indicating that the rear edge of the paper has been detected. The image forming apparatus according to claim 1 or 2, wherein the image forming apparatus is generated and the paper transport is controlled based on the signal value. The control means according to any one of claims 1 to 4, wherein when the paper having no used area is conveyed, the control means controls the paper transfer based on the output signal of the paper detection means. Image forming device. Claims 1 to 5, wherein the range in which the paper is detected by the paper detecting means is defined in a range of a predetermined length centered on the position where the paper detecting means is arranged. The image forming apparatus according to any one item.

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