JP2020033131A - Image forming device and control method of image forming device - Google Patents

Abstract

To provide a technology preventing erroneous detection to identify no paper in a manual tray and like, as paper jam.SOLUTION: An image forming device 100 is provided with: a manually feeding tray 101 on which a plurality of papers are loaded; a paper transporting unit 103 transporting the papers from the manually feeding tray 101; a paper length detection unit 201 arranged on the manually feeding tray to detect each length of the papers loaded on the manually feeding tray in the transport direction; and a controller 110 controlling the image forming device 100. The controller 100 delays start of transporting successive papers for a predetermined time when a detected result with the paper length detection unit 201 is changed during transporting the papers by the paper transporting unit 103.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to an image forming apparatus, and more specifically, to a sheet conveyance control in an image forming apparatus.

  2. Description of the Related Art As a type of an image forming apparatus such as a printer and a multifunction peripheral, there is a type that uses toner for development. An image forming apparatus using these toners directly or indirectly transfers toner for development using a photoreceptor to a sheet as a transfer-receiving medium, and further transfers the toner to a sheet by a fixing roller. It is common to fix toner.

  2. Description of the Related Art In recent years, as the image forming apparatus has become clearer and faster, and has responded to many media, high reliability of paper feeding from a paper feeding unit has been required. Further, in order to improve convenience, it is required to accurately present the cause of the interruption of the paper supply to the user when the paper supply is interrupted. That is, it is desirable that the cause of the paper supply interruption be specified by presenting the cause of the paper shortage or the paper jam to the user, and the normal state can be easily restored.

  For example, Japanese Patent Laying-Open No. 2002-60092 (Patent Literature 1) discloses that “a sheet storage unit that stacks and stores a plurality of sheets, and that the sheets are fed out one by one based on a sheet feed start signal. A paper feeding mechanism for feeding paper to the paper end, a paper jam detecting means for detecting whether or not the paper sent from the paper storing means is passed by the paper feeding mechanism, and a swinging motion of the uppermost sheet stored in the paper storing means. No paper detection means for detecting the presence or absence of paper in the storage means based on the fluctuation of the swinging member which is movably touched, display means for displaying required information, paper feed mechanism, paper jam detection means, and no paper detection means And a control means for determining whether there is a paper jam or no paper based on the detection information from each of the detection means, and displaying the determination result on the display means. Determines that there is a paper jam based on the detection information from the paper jam detection means, suspends the display of the determination result on the display means until a predetermined time elapses, and detects from the paper absence detection means during the suspension. If it is determined that there is no paper based on the information, it is set so that the display of the determination result on the display means is preferentially executed. "(Patent [0009]).

JP-A-2002-60092

  According to the technique disclosed in Japanese Patent Application Laid-Open No. H11-163, as long as a configuration in which a paper absence detection sensor such as a paper feed cassette can be arranged to some extent upstream from the paper feed mechanism, erroneous detection of a paper break as a paper jam is reduced to some extent. Can be prevented.

  However, in a configuration such as a manual feed tray, a sensor (hereinafter, referred to as an “FD (Feed Dimension) detection sensor”) that detects the length of the paper placed on the manual feed direction in the transport direction, and a tray. It is necessary to install both sensors for detecting whether or not sheets are loaded (hereinafter, referred to as “empty detection sensor”). Due to the configuration, it is necessary to arrange the empty detection sensor near the paper feeding mechanism. Therefore, in applications that require high-speed paper feed, where the paper feed interval is short, the interval between the conveyed paper and the following paper is very short, and the empty detection sensor cannot catch up with the detection of the paper exhaustion. Incorrect detection may occur. Therefore, there is a need for a technique for preventing erroneous detection of a paper jam that can be applied to a manual feed tray.

  The present disclosure has been made in view of the above background, and an object of one aspect is to provide a technique for preventing a paper feed mechanism such as a manual feed tray from erroneously detecting a paper out condition as a paper jam. Is to do.

  An image forming apparatus according to a certain aspect includes a manual tray on which a plurality of sheets are placed, a sheet transport unit that transports the sheets from the manual tray, and a sheet feeding unit provided on the manual tray. The image forming apparatus includes a sheet length detection unit that detects a length in the transport direction and a control unit that controls the image forming apparatus. The control unit delays the start of the conveyance of the succeeding sheet by a predetermined time when the detection result of the sheet length detection unit changes during the conveyance of the sheet by the sheet conveyance unit.

  In a certain aspect, the image forming apparatus further includes an empty detection unit that is disposed along a sheet conveyance path and detects the presence or absence of a sheet set on a manual feed tray. Due to the delay of the start of the conveyance of the subsequent sheet, the conveyance of the subsequent sheet is started after the empty detection unit detects the presence or absence of the sheet.

  In one aspect, the image forming apparatus further includes a display unit that displays information to a user. When the control unit determines that the paper in the manual feed tray has run out during the paper feeding operation based on the detection result of the paper length detection unit, the control unit displays the paper out information on the display unit regardless of the detection result of the empty detection unit. I do.

  In one aspect, the image forming apparatus further includes a display unit that displays information to a user. When the detection result of the paper length detecting unit changes during the paper feeding operation, and the empty detecting unit detects that the paper has run out, the control unit displays information on the running out of paper on the display unit.

  In a certain aspect, the image forming apparatus further includes a sheet width detection unit that detects a width in a sheet conveyance direction. The control unit determines the paper size based on each detection result of the paper length detection unit and the paper width detection unit.

  In one aspect, the control unit adjusts a predetermined time based on the detection results of the sheet length detection unit and the sheet width detection unit.

  In one aspect, the image forming apparatus further includes an operation unit that receives an input from a user. The control unit adjusts a predetermined time based on the input paper size regardless of each detection result of the paper length detection unit and the paper width detection unit when the paper size is input by the operation unit. .

  In one aspect, the paper length detection unit is arranged below the paper set on the manual feed tray.

  In one aspect, the paper length detection unit includes a transmission sensor and a light blocking part of the transmission sensor.

  According to another embodiment, a control method in an image forming apparatus is provided. The control method includes a step of detecting a sheet placed at a position where the sheet can be conveyed on the manual feed tray, a step of conveying the sheet from the manual feed tray via a roller, and a subsequent sheet of the sheet conveyed via the roller. Detecting the presence / absence of paper, and if the length of the paper placed in the transportable position on the manual feed tray in the transport direction cannot be detected while the paper is being transported through the rollers, Delaying the drive for transporting for a predetermined time.

  In one aspect, the control method further includes a step of restarting the driving of the roller after the detection of the presence or absence of the subsequent sheet is performed due to a delay.

  In one aspect, the control method includes determining whether or not there is a subsequent sheet when the length of the sheet placed in a position where the sheet can be transported on the manual feed tray in the transport direction cannot be detected during the transport of the sheet via the roller. The method further includes the step of displaying out-of-paper information irrespective of the detection of.

  In one aspect, the control method may not be able to detect the length in the transport direction of the paper placed at the transportable position on the manual feed tray during the transport of the paper via the roller, and the subsequent paper may run out. The method further includes the step of displaying out-of-paper information when detected.

  According to the present technology, it is possible to prevent a paper feed mechanism such as a manual feed tray from erroneously detecting a paper-out condition as a paper jam.

  The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention that is understood in connection with the accompanying drawings.

FIG. 1 is a configuration diagram showing a configuration example of an image forming apparatus 100 according to the present embodiment. FIG. 2 is a configuration diagram showing a configuration example of a manual feed tray 101 of the image forming apparatus 100 according to the present embodiment. FIG. 2 is a configuration diagram showing a configuration example of an FD detection sensor 201 of image forming apparatus 100 according to the present embodiment. FIG. 5 is a diagram illustrating the operation of a sensor and a roller at each stage of transporting a sheet. FIG. 5 is a diagram illustrating a state of conveyance of a sheet in a stage A of FIG. 4. FIG. 5 is a diagram illustrating a paper conveyance state in a stage B of FIG. 4. FIG. 5 is a diagram illustrating a state of conveyance of a sheet in a stage C of FIG. 4. FIG. 5 is a diagram illustrating a paper conveyance state in a stage D of FIG. 4. FIG. 5 is a diagram illustrating a state of conveyance of a sheet in a stage E of FIG. 4. FIG. 5 is a diagram illustrating a sheet conveyance state in a stage F of FIG. 4. 5 is a flowchart showing conveyance delay control according to the present embodiment. 5 is a flowchart illustrating a process for preventing erroneous determination of a paper out and a paper jam according to the present embodiment.

  Hereinafter, embodiments of the technical concept according to the present disclosure will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are the same. Therefore, detailed description thereof will not be repeated.

[First Embodiment]
<A. Apparatus Configuration of Image Forming Apparatus 100>
First, the device configuration of image forming apparatus 100 according to the present embodiment will be described. As a typical example, an image forming apparatus 100 that is a color image forming apparatus implemented as a multi-function peripheral (MFP) will be described. However, the technical idea according to the present embodiment is limited to a color image forming apparatus. However, the present invention is also applicable to a monochrome image forming apparatus.

  FIG. 1 is a diagram showing a configuration example of an image forming apparatus 100 according to the present embodiment. Referring to FIG. 1, image forming apparatus 100 includes a manual feed tray 101, a paper feed cassette 102, a paper feed roller 103, a registration roller 104, an imaging unit 105, an intermediate transfer belt 106, and a transfer roller 107. , A fixing unit 108, a discharge tray 109, and a control unit 110.

  The imaging unit 105 includes a photoconductor, a charging unit, an exposure unit, and a developing unit. The imaging unit 105 includes a plurality of imaging units for generating respective toner images of cyan (C), magenta (M), yellow (Y), and black (K).

  Image forming apparatus 100 according to the present embodiment employs, for example, a configuration in which toner images generated by respective imaging units 105 are transferred to a member to be transferred via intermediate transfer belt 106. Although FIG. 1 illustrates a configuration in which the toner image is temporarily transferred to the intermediate transfer belt 106 and then transferred to the transfer member, a configuration in which the toner image on the photoconductor is directly transferred to the transfer member is adopted. Is also good.

  The paper is placed on either the manual feed tray 101 or the paper feed cassette 102. The paper feed roller 103 transports the paper placed on the manual tray 101 or the paper feed cassette 102 one by one to a paper transport path. The registration roller 104 transports the paper transported by the paper feed roller 103 further downstream. The transfer roller 107 transfers the transfer image on the intermediate transfer belt 106 to the conveyed sheet. The fixing unit 108 melts the toner transferred to the surface of the sheet and fixes it on the sheet. The sheet completed up to the fixing process is discharged to a discharge tray 109. The control unit 110 controls the overall operation of the image forming apparatus 100.

<B. Configuration of Bypass Tray 101>
FIG. 2 is a diagram showing a configuration example of the manual feed tray 101 of the image forming apparatus 100 according to the present embodiment. 2, the manual feed tray 101 includes an FD detection sensor 201, a sheet width detection sensor 202, a push-up plate 203, an empty detection sensor 204, and a double feed prevention member 205.

  The FD detection sensor 201 is disposed on the manual feed tray 101 so as to be below the sheet, and includes a protrusion configured to sink under the weight of the sheet. The protruding portion sinks under the weight of the paper placed on the manual feed tray. The paper width detection sensor 202 detects the width of the sandwiched paper. The control unit 110 automatically determines a standard paper size such as A4 or A3 from the detection results of the paper width detection sensor 202 and the FD detection sensor 201. The FD detection sensor 201 also detects whether the sheet is placed at an appropriate position.

  The push-up plate 203 rotates about the fulcrum Z, and pushes up the leading edge of the sheet placed on the manual feed tray 101 to a position where the sheet comes into contact with the sheet feed roller 103. The empty detection sensor 204 detects the presence or absence of a sheet on the manual feed tray 101. The double feed preventing member 205 is for preventing a plurality of sheets from being simultaneously conveyed by the sheet feeding roller.

<C. Configuration of FD detection sensor 201>
FIG. 3 shows a configuration example of FD detection sensor 201 of image forming apparatus 100 according to the present embodiment. Referring to FIG. 3, FD detection sensor 201 includes transmission type sensor 301 and light shielding part 302. The FD detection sensor 201 is provided inside the manual feed tray 101.

  When the sheet is not placed on the manual feed tray 101, the torsion coil spring lifts the projection of the light blocking part 302 from the hole 303 to the upper side of the manual feed tray 101. In this state, since the light blocking part 302 blocks the light of the transmission sensor 301, the input to the FD detection sensor 201 is turned off.

  On the other hand, when a sheet is placed on the manual feed tray 101, the protrusion of the light shielding part 302 sinks due to the weight of the sheet. As a result, the portion of the light shielding part 302 that has blocked the light of the transmission sensor 301 is lifted, and the input to the FD detection sensor 201 is turned ON.

  The configuration of the FD detection sensor 201 is not limited to the contents shown in FIG. 3, but may be any type other than the transmission type sensor as long as it can detect that a sheet is loaded. Further, when no paper is placed on the manual feed tray 101, the input of the FD detection sensor 201 is turned on, and when paper is loaded on the manual feed tray 101, the input of the FD detection sensor 201 is turned off. You may do so.

<D. Paper transport control>
FIG. 4 is a diagram showing the operation of each sensor and each roller at each stage of paper transport. Hereinafter, the operation of each unit of the image forming apparatus 100 at each transport stage in FIG. 4 will be described with reference to FIGS. The control unit 110 performs input reading of various sensors and rotation control of various rollers.

  FIG. 5 is a diagram showing an example of the arrangement of the manual feed tray 101 and peripheral components of the manual feed tray 101 of the image forming apparatus 100. FIG. FIG. The registration roller 104 transports the paper transported by the paper feed roller 103 toward the transfer roller 107. The sheet 501, the sheet 502, and the sheet 503 are located inside the image forming apparatus 100 or on the manual feed tray 101, respectively.

  At the position of the primary conveyance start 401 in the stage A of FIG. 4, the registration roller 104 is conveying the paper 501. The leading end of the sheet 502 is located at the position of the sheet feeding roller 103. In this state, the control unit 110 determines that there is a sheet on the manual feed tray 101 based on the input from the empty detection sensor 204. Further, the FD detection sensor 201 is pushed down by the weight of the sheet, and the control unit 110 determines that the sheet is present at a position where the manual feed tray 101 can be conveyed based on the input of the FD detection sensor 201.

  The control unit 110 starts the rotation of the sheet feeding roller 103 and conveys the sheet 502. The control unit 110 stops the rotation of the paper feed roller 103 after conveying the paper 502 until the leading end of the paper 502 reaches the position of the registration roller 104.

  FIG. 6 is a diagram showing the state of transporting the sheet in step B of FIG. In step B of FIG. 4, the control unit 110 ends the conveyance of the sheet 501 by the registration roller 104 before the leading end of the sheet 502 reaches the registration roller 104. Next, the control unit 110 stops the rotation of the registration roller 104, and shortly thereafter, stops the rotation of the sheet feeding roller 103. By doing so, even if the leading end of the sheet 502 reaches the position of the registration roller 104, the registration roller 104 does not immediately convey the sheet 502, so that an appropriate interval is provided between the sheet 501 and the sheet 502. Can be In the present embodiment, the appropriate interval is, for example, an interval at which two rollers are not simultaneously conveyed by one roller. The transfer of the leading end of the sheet placed on the manual feed tray 101 to the position of the registration roller 104 by the sheet feeding roller 103 as in steps A and B is performed in order to distinguish the sheet from the secondary transfer described below. Called transport.

  FIG. 7 is a diagram showing the paper transport status in step C of FIG. At the position of the secondary conveyance start 402 in the stage C of FIG. 4, the control unit 110 starts the rotation of both the sheet feeding roller 103 and the registration roller 104. By doing so, the leading end of the sheet 502 is further conveyed before the position of the registration roller 104. When the sheet feed roller 103 has conveyed the sheet 502, the control unit 110 stops the rotation of the sheet feed roller 103. Even after the rotation of the paper feed roller 103 is stopped, the control unit 110 continues to rotate the registration roller 104 to start the next primary conveyance. When the registration roller 104 conveys the leading edge of the sheet further than the registration roller 104 as in step C, it is called secondary conveyance.

  FIG. 8 is a diagram showing the state of conveyance of the sheet in step D of FIG. At the position of the primary conveyance start 403 in the stage D of FIG. 4, the control unit 110 rotates the paper feed roller 103 to convey the last sheet 503 on the manual feed tray 101. When the sheet 503 is transported, the protrusion of the FD detection sensor 201 is lifted. When the protrusion of the FD detection sensor 201 is lifted and the input of the FD detection sensor 201 is turned off, the control unit 110 determines that there is no sheet at a position where the manual feed tray 101 can be conveyed based on the input of the FD detection sensor 201. I do. More precisely, the control unit 110 determines that there is no sheet following the sheet 503 currently being conveyed, and the sheet 503 is the last sheet.

  FIG. 9 is a diagram illustrating the state of conveyance of the sheet at the stage E in FIG. In step E of FIG. 4, similarly to step B, the control unit 110 ends the conveyance of the sheet 501 by the registration roller 104 before the leading end of the sheet 503 reaches the registration roller 104. After that, the control unit 110 stops the rotation of the registration roller 104, and shortly thereafter, stops the rotation of the sheet feeding roller 103.

  FIG. 10 is a diagram showing the state of conveyance of the sheet at the stage F in FIG. The control unit 110 starts the rotation of both the paper feed roller 103 and the registration roller 104 at the position of the secondary conveyance start 404 in FIG. By doing so, the control unit 110 causes the sheet feeding roller 103 and the registration roller 104 to convey the leading end of the sheet 503 further ahead of the position of the registration roller 104. When the sheet feed roller 103 has conveyed the sheet 502, the control unit 110 stops the rotation of the sheet feed roller 103. The control unit 110 continues to rotate the registration roller 104 to start the next primary transport.

  Normally, the control unit 110 starts the rotation of the paper feed roller 103 at the position of the primary transport delay control 405. However, before the position of the primary transport delay control 405, if the control unit 110 determines that there is no paper based on the input of the empty detection sensor 204, the control unit 110 starts the rotation of the paper feed roller 103. And stop the transfer process.

  However, the interval between the conveyed sheets may be very short, and the detection by the empty detection sensor 204 may be delayed. In this case, the control unit 110 starts the rotation of the paper feed roller 103 without stopping the transport process. In this case, since the paper to be conveyed does not exist on the manual feed tray 101, the paper will not be conveyed to the position of the registration roller 104 even after a certain period of time.

  If the leading edge of the paper has not been conveyed to the position of the registration roller 104 even after a certain period of time from the start of the rotation of the paper feed roller 103, the control unit 110 erroneously determines that a paper jam has occurred, and performs image formation. The apparatus 100 displays information indicating that a paper jam has occurred on a liquid crystal monitor or the like.

  In order to prevent erroneous determination due to the detection delay of the empty detection sensor 204, in the present embodiment, when the FD detection sensor 201 determines that there is no succeeding paper, the control unit 110 determines the position shown in FIG. As indicated by X, the rotation start of the paper feed roller 103 is delayed for a certain period of time (for example, a period of time sufficient for completing the detection processing of the empty detection sensor 204). By doing so, the empty detection sensor 204 can complete the detection of the presence or absence of the sheet before the control unit 110 starts the rotation of the sheet feeding roller 103. As a result, the control unit 110 can complete the paper-out determination based on the input from the empty detection sensor 204 before the paper-paper determination, and eliminate the erroneous determination that the paper-out is a paper jam. Can be. Note that the control unit 110 may change the delay time according to each sheet size determined by the FD detection sensor 201 and the sheet width detection sensor 202. For paper whose size cannot be automatically determined by the FD detection sensor 201 and the paper width detection sensor 202, the control unit 110 determines the paper size and sets a delay time in accordance with the user's operation buttons or touch panel operation. You may.

<E. Flowchart of transport delay control>
FIG. 11 is a flowchart showing the transport delay control according to the present embodiment. With reference to FIG. 11, an example of the flow of the conveyance delay control for preventing the erroneous determination of the paper out and the paper jam will be described.

  In step S1105, when detecting a sheet feed start signal (YES in step S1105), control unit 110 shifts the control to step S1110. The feed start signal is generated, for example, when a user operates an operation button or a touch panel of the image forming apparatus 100. When detecting no sheet feeding start signal (NO in step S1105), control unit 110 repeats step S1105 and continues to wait for the sheet feeding start signal. Alternatively, the control unit 110 may end the processing instead of continuing to wait for the sheet feeding start signal.

  In step S <b> 1110, the control unit 110 determines whether or not a sheet is placed on the manual feed tray 101 based on the input of the empty detection sensor 204. If control unit 110 determines that no paper is detected by empty detection sensor 204 and paper is placed on manual feed tray 101 (NO in step S1110), control unit 110 shifts control to step S1115. If the empty detection sensor 204 detects that there is no paper and the control unit 110 determines that no paper is placed on the manual feed tray 101 (YES in step S1110), the control unit 110 shifts the control to step S1140.

  In step S1115, the control unit 110 starts the rotation of the paper feed roller 103 for primary transport control. When the leading end of the conveyed sheet reaches the position of the registration roller 104, the control unit 110 stops the rotation of the sheet feeding roller 103.

  In step S <b> 1120, control unit 110 determines whether or not the sheet is at a position where manual feed tray 101 can be conveyed, based on the input from FD detection sensor 201. The determination may be made based on the input of the FD detection sensor 201 and the input of the empty detection sensor 204. Note that the control unit 110 may execute the process of step S1120 without waiting for the process of step S1115 to be completed. When the protrusion of the FD detection sensor 201 is kept pressed down by the weight of the sheet, the signal of the FD detection sensor 201 does not change, so the control unit 110 determines that the sheet is at a position where the sheet can be transported. On the other hand, when the last sheet is conveyed and the protrusion of the FD detection sensor 201 is lifted, a change occurs in the signal of the FD detection sensor 201. judge. If control unit 110 determines that the sheet is at a position where manual feed tray 101 can be conveyed (NO in step S1120), control unit 110 shifts the control to step S1130. If control unit 110 determines that the paper is not at a position where manual tray 101 can be conveyed (YES in step S1120), control proceeds to step S1125.

  In step S1130, the control unit 110 rotates the paper feed roller 103 and the registration roller 104 for secondary conveyance, and conveys the sheet conveyed in step S1115 to the transfer roller 107.

  In step S1125, the control unit 110 shifts the control to step S1130 after performing a delay setting of the primary transport start time such as setting a flag on a program. In this embodiment, the delay setting refers to a setting in which the start time of the primary transport is delayed from the original time. For example, the control unit 110 delays the start time of the next primary transport by a time sufficient for completing the detection processing by the empty detection sensor 204 after the secondary transport. In step S1135, the control unit 110 performs the primary transport delay process only when the delay setting of the primary transport start time is performed. When the control unit 110 performs the delay processing of the primary transport, the start timing of the next primary transport is later than usual, so that even if the detection processing by the empty detection sensor 204 is delayed after the secondary transport, The primary transport is not started first.

  The primary transport and the secondary transport of the sheet are completed by the processing in steps S1115 to 1135. Thereafter, the control unit 110 repeats the processing from step S1110 until the conveyance of the specified number of sheets is completed.

  In step S1140, control unit 110 determines whether or not the process of transporting the specified number of sheets has been completed, based on input from the operation buttons of image forming apparatus 100 or the like. If control unit 110 determines that the process of transporting the specified number of sheets has been completed (YES in step S1140), the process ends. If the control unit 110 determines that the conveyance process for the specified number of sheets has not been completed (NO in step S1140), the control unit 110 shifts the control to step S1145.

  In step S1145, control unit 110 displays information indicating that the paper has run out on a liquid crystal screen or the like of image forming apparatus 100. In step S1150, control unit 110 temporarily stops the sheet feeding operation. In step S1155, control unit 110 waits until paper is replenished. When the empty detection sensor 204 and the FD detection sensor 201 detect that a sheet is newly placed, the control unit 110 shifts the control to step S1105.

  As described in detail above, the image forming apparatus 100 according to the present embodiment prevents erroneous detection of out of paper as a paper jam even in a paper feeding mechanism such as a manual feed tray, and provides correct information to a user. Can be displayed, and convenience can be improved.

[Second embodiment]
Hereinafter, a second embodiment will be described. Note that the hardware of the image forming apparatus 100 according to the present embodiment is the same as the hardware configuration of the image forming apparatus 100 according to the first embodiment. Therefore, the description of the hardware configuration will not be repeated.

  FIG. 12 is a flowchart showing processing for preventing erroneous determination of a paper jam and out of paper according to the present embodiment. With reference to FIG. 12, a flow of processing for preventing erroneous determination of a paper out and a paper jam will be described. The same processes as those shown in the flowchart of FIG. 11 are denoted by the same reference numerals. Therefore, the description of the same processing will not be repeated.

  In step S1205, when control unit 110 detects that the input of FD detection sensor 201 has changed (YES in step S1205), control unit 110 shifts the control to step S1140. According to the present embodiment, when the input of the FD detection sensor 201 changes, the control unit 110 performs the out-of-paper determination processing without performing the delay processing setting of the primary paper feeding. Is different.

  According to the present embodiment, control unit 110 determines that there is no more paper when the input of FD detection sensor 201 changes after the start of primary paper feeding. The FD detection sensor 201 is arranged at a position corresponding to the length of the paper in the transport direction according to the standard. When the primary transport of the last paper starts, the protrusion pressed down by the paper is immediately lifted up. The input value changes. Therefore, if the control unit 110 uses the FD detection sensor 201 instead of the empty detection sensor 204 and determines that the paper is exhausted when the input of the FD detection sensor 201 changes, the control unit 110 can more easily determine that the paper jam has occurred. Misjudgment of cutting can be prevented.

  However, the present embodiment is applicable to paper of a size conforming to the standard such as A4, and the first embodiment is used for paper of a size not conforming to the postcard size or the standard. Is more desirable.

  In another aspect, the first embodiment and the second embodiment are used in combination, and the processing according to the second embodiment is performed only on paper having a size conforming to the standard such as A4. The processing according to the first embodiment may be applied to other paper.

  The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  Reference Signs List 100 image forming apparatus, 101 manual feed tray, 102 paper feed cassette, 103 paper feed roller, 104 registration roller, 105 imaging unit, 106 intermediate transfer belt, 107 transfer roller, 108 fixing unit, 109 discharge tray, 110 control unit, 201 FD Detection sensor, 202 Paper width detection sensor, 203 Push-up plate, 204 Empty detection sensor, 205 Double feed prevention member, 301 Transmission type sensor, 302 Light shielding part, 303 hole, 402, 404 Secondary transport start, 405 next transport delay control , 501, 502, 503 paper.

Claims (13)

An image forming apparatus,
A manual feed tray on which a plurality of sheets are placed,
A paper transport unit that transports paper from the manual tray,
Provided in the manual tray, a paper length detection unit that detects the length in the transport direction of the paper placed on the manual tray,
A control unit for controlling the image forming apparatus,
The image forming apparatus, wherein the control unit delays the start of conveyance of a subsequent sheet by a predetermined time when a detection result of the sheet length detection unit changes during conveyance of the sheet by the sheet conveyance unit. Further comprising an empty detection unit arranged along the paper transport path and detecting the presence or absence of the paper set in the manual feed tray,
The image forming apparatus according to claim 1, wherein, due to the delay, conveyance of a subsequent sheet is started after the empty detection unit detects the presence or absence of a sheet. Further comprising a display unit for displaying information to the user,
The control unit, based on the detection result of the paper length detection unit, when it is determined that the paper in the manual feed tray has run out during the paper feeding operation, regardless of the detection result of the empty detection unit, the paper on the display unit The image forming apparatus according to claim 2, wherein the image forming apparatus displays cut information. Further comprising a display unit for displaying information to the user,
The control unit, when the detection result of the paper length detection unit changes during a paper feeding operation, and when the empty detection unit detects that the paper has run out, displays information indicating that the paper has run out on the display unit. 3. The image forming apparatus according to 2. Further provided is a paper width detection unit that detects the width of the paper in the transport direction,
The image forming apparatus according to claim 1, wherein the control unit determines a sheet size based on each detection result of the sheet length detection unit and the sheet width detection unit.   The image forming apparatus according to claim 5, wherein the control unit adjusts the predetermined time based on detection results of the sheet length detection unit and the sheet width detection unit. It further includes an operation unit that accepts input from the user,
The control unit, when a paper size is input by the operation unit, regardless of each detection result of the paper length detection unit and the paper width detection unit, based on the input paper size, the predetermined The image forming apparatus according to claim 6, wherein the time is adjusted.   The image forming apparatus according to claim 1, wherein the sheet length detection unit is disposed below a sheet set on the manual tray.   The image forming apparatus according to claim 1, wherein the sheet length detection unit includes a transmission sensor and a light blocking part of the transmission sensor. Detecting a sheet placed at a position where it can be transported on the manual feed tray;
Transporting the paper from the manual tray via a roller,
Detecting the presence or absence of a succeeding sheet of the sheet conveyed through the roller,
During the conveyance of the paper via the rollers, when the length of the paper placed in the transportable position on the manual feed tray in the conveyance direction cannot be detected, the drive for conveying the subsequent paper by the rollers is performed. Delaying a predetermined time.
A control method in the image forming apparatus.   The control method according to claim 10, further comprising restarting the driving of the roller after detecting the presence or absence of a succeeding sheet.   If the length of the paper placed in the transportable position on the manual feed tray in the transport direction cannot be detected while the paper is being transported via the rollers, the paper runs out regardless of the detection of the presence of the succeeding paper. The control method according to claim 11, further comprising a step of displaying the information of (1).   During the conveyance of the paper via the rollers, the length of the paper placed in the position where the paper can be conveyed on the manual feed tray in the conveyance direction cannot be detected, and if the subsequent paper is detected to be out, the paper out is detected. The control method according to claim 11, further comprising a step of displaying information.

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