JP2010210658A - Image forming apparatus and method of controlling carrying sheet material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, suitably displaying "different size". <P>SOLUTION: In this image forming apparatus, when the occurrence of a paper jam is determined, in the case where a sheet causing this paper jam is the first sheet after the size of sheets stored in a paper feed cassette is changed, "different size" is displayed on a screen. This display of "different size" on the screen informs that the size specified by a user does not match the size of a sheet stored in the paper feed cassette. On the other hand, in the case where the sheet causing the paper jam is the second and following, the image forming apparatus is adapted to display "paper jam" on the screen. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image on a conveyed sheet material and a sheet material conveyance control method thereof.

  2. Description of the Related Art Conventionally, image forming apparatuses such as printers, copiers, and facsimile machines are provided with storages (called cassettes, decks, pedestals, and the like) for storing sheet materials. The storage is provided with a dial for designating the size of the sheet material. The user adjusts the dial to the size of the sheet material to be set.

  The image forming apparatus performs conveyance control of the sheet material based on the size specified by the user. For this reason, when the size of the sheet material set by the user in the storage is different from the size of the sheet material specified by the user with the dial, the following problem occurs. That is, since the image forming apparatus performs conveyance control according to the size of the sheet material designated by the user with the dial, paper jams, image defects, contamination of the apparatus due to toner that has not been transferred to the sheet material, and the like have occurred.

  On the other hand, an image forming apparatus described in Patent Document 1 is disclosed. When the sheet material stored in the storage is transported, the image forming apparatus detects the time when the “paper present” of the sensor for detecting presence / absence of paper provided on the transport path is detected, and transport of the sheet material. The length of the paper is calculated from the speed. Then, the image forming apparatus determines whether or not the size specified by the user is correct. If the size is incorrect, the image forming apparatus displays on the operation unit that the size is different. Further, this image forming apparatus uses a plurality of sensors, and when the downstream sensor in the transport direction detects the presence of paper within a predetermined time, correction of the detection result of the paper size in consideration of the distance from the upstream sensor. I do.

JP-A-8-87204

  However, the conventional image forming apparatus has the following further problems. That is, even when the control described in Patent Document 1 is performed, the method for calculating the paper length of the sheet material based on the time when the sensor detects “paper present” is a member for conveying the sheet material (such as a roller). ) Slip, it was difficult to distinguish between paper jams and size differences. Accordingly, even when a paper jam occurs due to an abnormality in the apparatus, there is a possibility that a size difference is displayed.

  Accordingly, the present invention has been made to solve such a problem, and an object thereof is to provide an image forming apparatus capable of appropriately displaying a difference in size and a sheet material conveyance control method thereof. .

  In order to achieve the above object, an image forming apparatus according to the present invention includes an image forming unit that forms an image on a sheet material, a sheet storage unit that stores the sheet material, and a state that detects a change in the state of the sheet storage unit. A change detecting unit; a conveying unit configured to convey the sheet material stored in the sheet storing unit to the image forming unit; and a conveying path configured to convey the sheet material by the conveying unit to detect the presence or absence of the sheet material. A sheet detection unit; a paper jam determination unit that determines a paper jam when a sheet material is detected for a predetermined time by the sheet detection unit; a display unit that displays a status of the apparatus; and a control that controls display of the display unit And the control means is configured such that after the state change is detected by the state change detection means, the sheet material determined to be paper jam by the paper jam determination means is detected. In the case of the first sheet, a display is made to notify the display means that the preset size of the sheet material is different from the size of the sheet material stored in the sheet storage means, In the case of the second and subsequent sheets, the display unit is controlled to display to notify that a paper jam has occurred.

  The sheet material conveyance control method of the image forming apparatus according to the present invention includes an image forming unit that forms an image on a sheet material, a sheet storage unit that stores the sheet material, and a sheet material stored in the sheet storage unit. In a sheet material conveyance control method for an image forming apparatus, comprising: a conveyance unit that conveys the sheet to a forming unit; and a display unit that displays a state of the apparatus. The image forming apparatus is disposed on a conveyance path for conveying the sheet material. A sheet detection step for detecting the presence or absence of the sheet material by the provided sheet detection means, and a paper jam determination in which the image forming apparatus determines a paper jam when the sheet material is detected for a predetermined time in the sheet detection step. A state change detecting unit that detects a state change of the sheet storage unit, and the image forming apparatus determines whether the paper jam occurs. When the sheet material determined to be jammed in step is the first sheet after the state change is detected in the state change detection step, the sheet size set in advance to the display means , A display for notifying that the size of the sheet material stored in the sheet storage means is different. On the other hand, in the case of the second and subsequent sheets, a display for notifying the display means that a paper jam has occurred. And a display control step for performing control so as to perform the above.

  In the image forming apparatus according to the first aspect of the present invention, only the first sheet after the change in the state of the sheet storage unit is detected, and a display notifying that the size is different when it is determined that a paper jam has occurred. Do. As a result, even when a paper jam occurs due to an abnormality in the apparatus, the second and subsequent sheets are not displayed with the size difference, and the size difference can be displayed appropriately.

  The image forming apparatus according to claim 2 displays a difference in size only when the first sheet after changing the designated size is determined to be a paper jam. As a result, it is possible to correct an error in the user's size specification with respect to the size of the sheet material stored in the sheet storage means.

  According to the image forming apparatus of the third to sixth aspects, it is possible to correctly detect various state changes in the sheet storage unit.

  According to the image forming apparatus of the seventh aspect, since the predetermined time is determined from the designated size and the conveyance speed, the predetermined time is uniquely determined according to the size, and a paper jam can be accurately determined.

  According to the image forming apparatus of the eighth aspect, when it is determined that the length of the sheet material calculated by the time when the sheet material is detected is longer than the specified size, it is determined that the paper is jammed. The display of the size difference can be performed more appropriately.

1 is a cross-sectional view illustrating an internal configuration of an image forming apparatus according to an embodiment. 3 is a front view showing an appearance of an operation unit 4. FIG. It is a figure which shows the screen of the operation display part 917. FIG. It is a partially broken side view which shows the size designation | designated mechanism of cassette 21a-21d. It is a block diagram which shows the hardware constitutions of the control unit 5 in sheet material conveyance control. It is a figure which shows the function implement | achieved when CPU501 executes the control program stored in ROM502 as a block. 5 is a flowchart illustrating a conveyance control procedure in a conveyance control unit 512. 5 is a flowchart illustrating a control procedure for determining size switching in a size switching determination unit 513; 7 is a flowchart illustrating a control procedure for detecting opening / closing of a cassette and driving a lifter motor to enable a sheet to be fed when the size switching determination unit 513 detects opening / closing of the cassette. 10 is a flowchart illustrating a display control procedure in the display control unit 514. It is a figure which shows the screen of the operation display part 917 which displays a size mistake. FIG. 10 is a diagram illustrating a screen of an operation display unit 917 that displays the occurrence of a paper jam.

  Embodiments of an image forming apparatus and a sheet material conveyance control method thereof according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an internal configuration of an image forming apparatus according to an embodiment. In FIG. 1, a control unit 5 to be described later is omitted.

  The image forming apparatus 1 includes a face-up discharge tray 2, a face-down discharge tray 3, an operation unit 4, photosensitive drums 11a, 11b, 11c, and 11d as photosensitive members, and roller chargers 12a, 12b, 12c, and 12d. Is provided. Further, scanners 13a, 13b, 13c, and 13d that are latent image forming units, developing devices 14a, 14b, 14c, and 14d that are developing units, and cassettes 21a, 21b, 21c, and 21d are provided.

  In addition, pickup rollers 22a, 22b, 22c, and 22d for feeding the sheet material P from the cassettes 21a to 21d one by one, BC rollers 23a, 23b, 23c, and 23d, and drawing rollers 24a to 24d are provided. Further, a registration roller 25, a pre-registration roller 26, a manual feed tray 27, a deck 28, a BC roller 29, an intermediate transfer member 30 that is an image carrier, and a drive roller 32 that transmits driving to the intermediate transfer member 30 are provided.

  Further, a tension roller 33 that applies an appropriate tension to the intermediate transfer member 30 by urging a spring (not shown) and a driven roller 34 that forms a secondary transfer region with the intermediate transfer member 30 interposed therebetween are provided. Further, the image formed on the intermediate transfer body 30 and the primary transfer rollers 35a to 35d, which are image carrier transfer portions to which a high pressure for transferring the toner image to the intermediate transfer body 30 is applied, are transferred to the sheet material P. A secondary transfer roller 36 is provided as a sheet material transfer portion for transferring to the sheet.

  Further, a fixing unit 41, a fixing roller 41a having a heat source such as a halogen heater inside, and a pressure roller 41b for pressing the sheet material P between the fixing roller 41a are provided. Note that this pressure roller may include a heat source.

  Further, the image forming surfaces of the inner discharge roller 44, the outer discharge roller 45, and the intermediate transfer member 30 that transport the sheet material P discharged from the pair of rollers including the fixing roller 41a and the pressure roller 41b are cleaned ( A cleaning device 50 is provided for cleaning. The cleaning device 50 includes a cleaner blade 51 and a waste toner box 52 that stores waste toner.

  In addition, a pickup roller 60, a paper feed roller 61, and a drawing roller 62 are provided.

  Also, cassette paper presence / absence sensors 63a, 63b, 63c, and 63d, paper feed pre-registration sensors 64a, 64b, 64c, and 64d as detection units, a deck paper feed sensor 65, a deck pull-out sensor 66, and a registration sensor (also referred to as a registration sensor) 67 Is provided.

  In addition, the internal paper discharge sensor 68, the face-down paper discharge sensor 69, the double-sided pre-registration sensor 70, the double-sided re-feed sensor 71, the reverse rollers 72a, 72b, 72c, the switching flapper 73, the double-sided rollers 74a to 74d, 75 is provided. In the figure, symbol L represents a loop and symbol R represents an inversion position. A tray paper presence / absence sensor 76 is also provided.

  Here, the pickup rollers 22a to 22d, the BC rollers 23a to 23d, the drawing rollers 24a to 24d, the pre-registration roller 26, the BC roller 29, the pickup roller 60, the paper feeding roller 61, the drawing roller 62, and the double-sided rollers 74a to 74d are conveyed. Forming part.

  The detection unit is not limited to the paper feed pre-registration sensors 64a to 64d, and other sensors can be used.

  The image forming apparatus 1 is roughly divided into an image forming unit, a paper feeding unit, an intermediate transfer unit, a transport unit, a fixing unit 40, an operation unit 4, and a control unit 5 (see FIG. 5). The image forming unit has four stations a, b, c, and d arranged side by side, and the configuration thereof is the same.

  Next, each structural unit will be described. The image forming unit includes photosensitive drums 11a to 11d, roller chargers 12a to 12d, scanners 13a to 13d, developing devices 14a to 14d, and primary transfer rollers 35a to 35d.

  The photosensitive drums 11a to 11d are pivotally supported at their centers, and are rotated and driven by a drive motor (not shown) in the direction of the arrow in the figure. The roller chargers 12a to 12d, the scanners 13a to 13d, and the developing devices 14a to 14d are arranged along the rotation direction facing the outer peripheral surfaces of the photosensitive drums 11a to 11d.

  The roller chargers 12a to 12d give a uniform charge amount to the surfaces of the photosensitive drums 11a to 11d. The scanners 13a to 13d cause a light beam such as a laser beam modulated according to the recording image signal to enter a rotating polygonal mirror (polygon mirror or the like) that rotates at a constant angular velocity, and the reflected scanning light is irradiated to the photosensitive drums 11a to 11d. Expose above. Thereby, electrostatic latent images are formed on the photosensitive drums 11a to 11d.

  The scanners 13a to 13d have a beam detect sensor (BD sensor) for detecting the reflected light of the rotary polygon mirror, and by counting the number of times the laser beam is incident on this BD sensor (BD signal), the image and the sheet material The timing can be adjusted. The scanner 13a exposes a black image, and outputs a signal obtained by dividing the BD signal by a predetermined division ratio to a CPU 501 described later.

  The developing devices 14a to 14d respectively store four colors of developer (toner) consisting of yellow, cyan, magenta, and black, and visualize the electrostatic latent images formed on the photosensitive drums 11a to 11d. . This visualized visible image is transferred to the intermediate transfer member 30.

  By the above process, image formation with each toner is sequentially performed. The start of image exposure is performed in response to the output of an image forming start signal output from a control unit 5 (see FIG. 5) described later.

  The sheet feeding unit includes a portion for storing the sheet material P, a roller for conveying the sheet material P, a sensor for detecting the passage of the sheet material P, a sensor for detecting the presence or absence of the sheet material P, and the sheet material It is comprised from the guide (not shown) for conveying P along a conveyance path | route.

  The deck 28 stores the sheet material P. In the pickup rollers 22a to 22d, a plurality of sheet materials P may be sent out, but only one sheet is reliably separated by the BC rollers 23a, 23b, 23c, and 23d.

  The sheet material P separated by only one sheet by the BC rollers 23 a to 23 d is further transported by the drawing rollers 24 a to 24 d and the pre-registration roller 26, and is transported to the registration roller 25.

  The pickup roller 22a, the BC roller 23a, and the drawing roller 24a are driven by a paper feed motor 505 (see FIG. 5) described later. Similarly, the pickup roller 22b, the BC roller 23b, and the drawing roller 24b are also driven by another motor (not shown). That is, the pickup roller, the BC roller, and the drawing roller are driven by separate motors (not shown) for each of the stations a, b, c, and d.

  When the solenoid (SL) 504 (see FIG. 5) is operated, the pickup roller 22a performs an operation of feeding the sheet material P by the action of the gear and the cam. The same applies to the pickup rollers 22b to 22d.

  The sheet material P stored in the manual feed tray 27 is separated by the BC roller 29 and conveyed to the registration roller 25 by the pre-registration roller 26.

  A plurality of sheets P stored in the deck 28 are conveyed to the paper feed roller 61 by the pickup roller 60, and only one sheet is reliably separated by the paper feed roller 61 and conveyed to the drawing roller 62. Further, the sheet material P is conveyed to the registration roller 25 by the pre-registration roller 26. The pre-registration roller 26 and the BC roller 29 are driven by a pre-registration motor (not shown). In addition, the detection signal of each said sensor is input into the control unit 5. FIG.

  Next, the intermediate transfer unit will be described in detail. The intermediate transfer member 30 is supported by a driving roller 32, a tension roller 33, and a driven roller. The drive roller 32 is rotated and driven by a stepping motor (not shown).

  Primary transfer rollers 35 a to 35 d are arranged on the back of the intermediate transfer body 30 at positions where the respective photosensitive drums 11 a to 11 d and the intermediate transfer body 30 face each other.

  Further, a secondary transfer roller 36 is disposed so as to face the driven roller 34. A secondary transfer region is formed by the nip between the secondary transfer roller 36 and the intermediate transfer member 30. The secondary transfer roller 36 is pressed against the intermediate transfer member 30 with an appropriate pressure.

  A cleaning device 50 is disposed on the intermediate transfer member 30 downstream of the secondary transfer region. The cleaning device 50 includes a cleaner blade 51 and a waste toner box 52. The fixing unit 40 includes a fixing roller 41a, a pressure roller 41b, and an inner paper discharge roller 44.

  On the other hand, the sheet material P conveyed to the registration roller 25 is temporarily stopped by stopping the rotation driving of the roller upstream of the registration roller 25. Then, the conveyance of the sheet material P is resumed by starting the rotational driving of the upstream rollers including the registration rollers 25 in accordance with the image forming timing of the image forming unit.

  The sheet material P is sent out to a secondary transfer region described later. In the secondary transfer region, the sheet material P onto which the image has been transferred and the image has been fixed in the fixing unit 40 passes through the inner paper discharge roller 44, and then the transport destination is switched by the switching flapper 73.

  When the switching flapper 73 is on the face-up discharge side, the sheet material P is discharged to the face-up discharge tray 2 by the outer discharge roller 45. On the other hand, when the switching flapper 73 is on the face-down paper discharge side, the sheet material P is conveyed in the direction of the reversing rollers 72 a, 72 b, 72 c and discharged to the face-down paper discharge tray 3.

  When forming images on both sides of the sheet material, the sheet material is conveyed in the direction of the face-down paper discharge tray 3 and stops when the rear end of the sheet material P reaches the reverse position R, and the double-side rollers 74a to 74d are stopped. The direction of rotation of the reverse roller is reversed in the direction.

  Thereafter, the sheet material P is conveyed to the secondary transfer roller 36 as in the case of conveying the sheet material from the cassettes 21a to 21d.

  A plurality of sensors are arranged in the conveyance path of the sheet material P in order to detect the passage of the sheet material P. As a plurality of sensors, paper feed pre-registration sensors 64a, 64b, 64c, 64d, deck paper feed sensor 65, deck pull-out sensor 66, registration sensor 67, internal paper discharge sensor 68, face-down paper discharge sensor 69, double-side pre-registration sensor 70, double-side re-registration sensor 70 There is a paper feed sensor 71 and the like.

  In addition, cassette paper presence / absence sensors 63a, 63b, 63c, and 63d that detect the presence or absence of the sheet material P are disposed in the cassettes 21a to 21d that store the sheet material P. The manual feed tray 27 is provided with a manual tray paper presence / absence sensor 76 that detects the presence or absence of the sheet material P on the manual feed tray 27. The deck 28 is provided with a deck paper presence / absence sensor 75 that detects the presence or absence of the sheet material P in the deck 28.

  The operation unit 4 is disposed on the upper surface of the image forming apparatus 1. In the operation unit 4, selection of a sheet feeding unit (sheet feeding cassettes 21 a to 21 d, a manual feed tray 27, a deck 28) in which the sheet material P is stored, a sheet discharge tray (face-up sheet discharge tray 2, face-down sheet discharge tray 3). ) And tab sheet bundles can be specified.

  Next, details of the operation unit 4 will be described with reference to FIGS. 2 and 3. FIG. 2 is a front view showing the appearance of the operation unit 4. The operation unit 4 includes a start key 901 for starting an image forming operation, a stop key 902 for interrupting the image forming operation, a reset key 903 for returning display and settings to an initial state, and a numeric keypad for setting numerical values. 904 to 913 are arranged. Also, an ID key 914, a clear key 915, a user mode key 916, and the like are arranged.

  In addition, a liquid crystal display unit (operation display unit) 917 having a touch panel provided on the surface thereof is disposed above the operation unit 4. FIG. 3 is a diagram showing a screen of the operation display unit 917. Soft keys can be provided on the screen of the liquid crystal display unit. Normally, a standard screen as shown in FIG. 3 is displayed on the liquid crystal display unit (operation display unit) 917. Through this screen, the user performs operation settings related to image formation.

  Next, the size designation mechanism of the cassettes 21a to 21d will be described with reference to FIG. FIG. 4 is a partially broken side view showing the size designation mechanism of the cassettes 21a to 21d. In the cassettes 21 a to 21 d, the instruction dial 101 is formed in a disc shape and is rotatable around the support shaft 102. In addition, on the surface of the instruction dial 101, a plurality of size names are written substantially concentrically. Moreover, the notch 103 is provided in the side surface of cassette 21a-21d so that the operator can see the size name mentioned above.

  The cassettes 21a to 21d are provided with detection levers 104 and 105. The detection levers 104 and 105 are in contact with the back surface of the instruction dial 101. Concavities and convexities are formed on the back surface of the instruction dial 101, and the concavities and convexities push and pull the detection levers 104 and 105 (perpendicular to the drawing) according to the rotation angle of the instruction dial 101.

  When the detection lever 104 and the detection lever 105 move, the size switch (SW) 509 (two in FIG. 4 is provided but not shown) is turned ON / OFF. Four types of sizes can be designated by the combination of ON / OFF of these two size switches.

  FIG. 5 is a block diagram illustrating a hardware configuration of the control unit 5 in the sheet material conveyance control. FIG. 5 shows only the blocks necessary for explaining the features of the present invention.

  The control unit 5 includes a CPU 501, a ROM 502, a RAM 503, and an input / output port 510. The input / output port 510 includes a solenoid 504, a paper feed motor 505, a paper feed pre-registration sensor 506, a cassette paper presence / absence sensor 507, a paper feed cassette open / close detection sensor 508, and a size SW 509 for specifying a sheet size stored in the paper feed cassette. Etc. are provided. The input / output port 510 mediates input / output of these devices to the CPU 501. Here, the paper feed pre-registration sensor (paper feed sensor) 506 is a generic name of the paper feed pre-registration sensors 64a, 64b, 64c, 64d, and the like, and is an example of a sheet detection unit. The cassette paper presence / absence sensor 507 is a generic name of the cassette paper presence / absence sensors 63a, 63b, 63c, 63d, and the like, and is an example of a sheet presence / absence detection unit.

  The operation display unit 917 exchanges data through serial communication with the CPU 501. The control unit 5 includes a control board (not shown) for controlling the operation of the mechanism in each unit, a motor drive board (not shown), and the like.

  Next, the control contents of the CPU 501 in the control unit 5 will be described with reference to FIG. FIG. 6 is a block diagram showing functions realized by the CPU 501 executing the control program stored in the ROM 502. FIG. 6 shows functional blocks that are realized by the CPU 501 executing the control program, which are necessary for explaining the features of the present invention.

  The conveyance control unit 512 inputs the sheet feeding sensor 506 and drives the sheet feeding motor 505 and the pickup SL (solenoid) 504 to perform sheet material conveyance control. The size switching determination unit 513 receives the paper presence / absence sensor 507, the open / close detection sensor 508, and the size SW 509 as inputs, and determines size switching, cassette opening / closing, and paper presence / absence. In addition, when the size change determination unit 513 detects size change, cassette open / close or presence / absence of paper, the size change determination unit 513 notifies the display control unit 514 of the information. Further, when the conveyance control unit 512 detects a paper jam, the conveyance control unit 512 notifies the display control unit 514 of the paper jam.

  Upon receiving a paper jam notification from the conveyance control unit 512, the display control unit 514 receives a notification from the size switching determination unit 513, and the sheet that has caused the paper jam is the first sheet after the cassette size is switched. It is investigated whether it is. And the display control part 514 controls the content displayed on the operation display part 917 according to the result of investigation.

  Next, the control contents of the transport control unit 512 will be described with reference to FIG. FIG. 7 is a flowchart showing a conveyance control procedure in the conveyance control unit 512. As described above, this control program is stored in the ROM 502 in the control unit 5 and is executed by the CPU 501.

  First, the conveyance control unit 512 waits for the start of the paper conveyance operation (step S1). When the paper transport operation is started, the transport control unit 512 turns on the paper feed motor 505 (step S2). The conveyance control unit 512 turns on the pickup solenoid (SL) 504 (step S3).

  The conveyance control unit 512 waits for the elapse of a predetermined time (step S4), and turns off the pickup solenoid 504 when the predetermined time elapses (step S5).

  The conveyance control unit 512 monitors the paper feed sensor 506 and checks whether the paper feed sensor 506 is ON (step S6). If the paper feed sensor 506 is OFF, the conveyance control unit 512 checks whether or not a predetermined time has elapsed since entering the process of step S6 (step S7). If the predetermined time has not elapsed, the conveyance control unit 512 returns to the process of step S6.

  On the other hand, if the predetermined time has elapsed in step S7, the conveyance control unit 512 determines that the paper feed sensor 506 has not been turned on even after the predetermined time has elapsed, and determines that the jam has occurred (paper jam) ( Step S8). Thereafter, the conveyance control unit 512 proceeds to the process of step S14.

  On the other hand, if it is detected in step S6 that the paper feed sensor 506 is ON, the conveyance control unit 512 checks whether or not the paper feed sensor 506 is OFF (step S9). If the paper feed sensor 506 is OFF, the transport control unit 512 clears the flag information FLAG stored in the RAM 503 to a value of 0 (step S10). This flag information FLAG is set to a value of 1 in response to a change in size in the control of the size switching determination unit 513 described later. As described above, the flag information FLAG is cleared to 0 in response to the trailing edge of the first sheet passing through the paper feed sensor (through steps S6 and S9).

  After execution of step S10, the conveyance control unit 512 checks whether it is the conveyance of the last sheet (step S11). If there is a subsequent sheet, the conveyance control unit 512 returns to the process of step S1 and starts the conveyance operation for the next sheet. On the other hand, if there is no subsequent sheet, the conveyance control unit 512 turns off the paper feed motor 505 (step S14) and ends this control. Instead of ending this control, the process may return to step S1.

  On the other hand, if the paper feed sensor 506 remains ON in step S9, the conveyance control unit 512 determines whether or not the paper feed sensor 506 has been turned on for a predetermined time (step S12). If the predetermined time has not been continued, the conveyance control unit 512 returns to the process of step S9.

  On the other hand, if the sheet continues for a predetermined time, that is, if the sheet is detected by the paper feed sensor 506 for a predetermined time, the conveyance control unit 512 determines that the jam has occurred and notifies the display control unit 514 of the jam (step). S13). This determination is a paper jam where the sheet material stays at the sensor position because the paper feed sensor 506 has not been turned off even after a predetermined time has elapsed since the paper feed sensor 506 was turned on. It depends on what is considered. Further, since the “predetermined time” is obtained (determined) from the size of the sheet material and the conveyance speed, if the size specification of the sheet material is wrong, it is impossible to distinguish between the stay jam and the size difference. After the process of step S13, the conveyance control unit 512 proceeds to the process of step S14.

  Next, the control contents of the size switching determination unit 513 will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart showing a control procedure for determining size switching in the size switching determination unit 513. As described above, this control program is stored in the ROM 502 in the control unit 5 and is executed by the CPU 501.

  First, the size switching determination unit 513 reads the value of the size SW 509 and stores it in an area secured in the RAM 503 (this area is referred to as size2) (step S21). The size switching determination unit 513 compares the value of a separately secured area in the RAM 503 (this area is referred to as size1) and the value of the area size2 (step S22).

  If the value of the area size1 and the value of the area size2 match, it means that the size SW509 has not changed. In that case, the size switching determination unit 513 returns to the process of step S21. On the other hand, if they do not match, the size SW 509 has changed. In that case, the size switching determination unit 513 stores the value of the area size2 in the area size1 (step S23).

  Furthermore, the size switching determination unit 513 sets flag information FLAG indicating that the size has changed to a value 1 (step S24), and returns to the process of step S21.

  FIG. 9 is a flowchart showing a control procedure for detecting the opening / closing of the cassette in the size switching determination unit 513 and driving the lifter motor to make it possible to feed a sheet when the cassette is opened / closed. As described above, this control program is stored in the ROM 502 in the control unit 5 and is executed by the CPU 501.

  First, the size switching determination unit 513 determines whether or not the cassette is in an open state (step S31). The size switching determination unit 513 returns to the process of step S31 in the closed state.

  On the other hand, in the open state, the size switching determination unit 513 checks whether or not the cassette is in the closed state (step S32). If the size change determination unit 513 is in the open state, the process returns to step S32. On the other hand, in the open state, the size switching determination unit 513 drives a lifter motor (not shown) (step S33).

  The size switching determination unit 513 waits for a predetermined time to elapse after driving the lifter motor (step S34). After the predetermined time elapses, the size switching determination unit 513 stops driving the lifter motor (not shown) (step S35).

  The size switching determination unit 513 detects the presence or absence of paper from the signal of the paper presence / absence sensor 507 (step S36). If there is no paper, the size change determination unit 513 returns to the process of step S31. On the other hand, when there is paper, the size switching determination unit 513 sets the flag information FLAG to 1 because there is a possibility that the cassette has been opened and closed and a sheet of a different size has been set (step S37). Thereafter, the size switching determination unit 513 returns to the process of step S31.

  It should be noted that the flag information FLAG may be set to 1 by simply detecting the opening and closing of the cassette without detecting the presence or absence of paper in step S36. Further, the flag information FLAG may be set to a value 1 by detecting a change from the absence of paper to the presence of paper (change in the presence or absence of paper) according to the signal of the paper presence / absence sensor 507 without detecting the opening / closing of the cassette. Good. Alternatively, the flag information FLAG may be set to 1 even when the user operates the instruction dial 101 of the cassettes 21a to 21d to change the size switch 509. The processes in FIGS. 8 and 9 are examples of the state change detection unit, and the state change of the cassette (sheet storage unit) can be detected by at least one of these changes.

  Next, the control of the display control unit 514 will be described with reference to FIG. FIG. 10 is a flowchart showing a display control procedure in the display control unit 514. As described above, this control program is stored in the ROM 502 in the control unit 5 and is executed by the CPU 501.

  When execution of display control is started, the display control unit 514 first checks whether or not the conveyance control unit 512 has detected a delay jam in step S8 (step S41). If a delay jam is detected, the display control unit 514 proceeds to the process of step S45.

  On the other hand, when the delay jam is not detected, the display control unit 514 checks whether or not the conveyance control unit 512 detects the stay jam in Step S13 (Step S42). When the staying jam is not detected, the display control unit 514 returns to the process of step S41.

  On the other hand, when the stay jam is detected, the display control unit 514 reads the flag information FLAG and checks whether or not the flag information FLAG is set to a value 1 (step S43). When the flag information FLAG is set to a value of 1 (in the case of the first sheet), the display control unit 514 gives a size error to the operation display unit 917 of the operation unit 4 as shown in FIG. Is displayed (step S44). FIG. 11 is a diagram showing a screen of the operation display unit 917 for displaying a size error. On this screen, a “sheet size setting is different” window is displayed.

  On the other hand, when the flag information FLAG is 0 in step S43 (when the flag information FLAG is cleared in step S10, that is, in the case of the second and subsequent sheets), the display control unit 514 displays a paper jam in FIG. Is displayed to notify the user of the occurrence (step S45). FIG. 12 is a diagram showing a screen of the operation display unit 917 that displays the occurrence of a paper jam. On this screen, a “paper jam” window is displayed. After the process of step S44 or S45, the display control unit 514 ends this control.

  As described above, when it is determined that a paper jam has occurred, the image forming apparatus according to the present exemplary embodiment is configured such that the sheet that causes the paper jam is changed after the size of the sheet stored in the paper feed cassette is switched. If it is the first one of the screen, “size difference” screen display is performed. By this “size difference” screen display, it is notified that the size specified by the user and the size of the sheet stored in the paper feed cassette do not match. On the other hand, when the second sheet or more causes the paper jam, the image forming apparatus displays a “paper jam” screen.

  Thereby, since the display of a size difference is performed according to the presence or absence of the user's operation with respect to a cassette (storage), the size difference can be displayed appropriately. That is, when it is determined that the sheet (paper) length calculated based on the time when “paper is present” is detected is longer than the set size, the paper is set in the storage by the user. Alternatively, the size difference is displayed only on the first sheet after the size designation is changed. Therefore, the display of the size difference is appropriately performed.

  The present invention is not limited to the configuration of the above-described embodiment, and any configuration can be used as long as the functions shown in the claims or the functions of the configuration of the present embodiment can be achieved. Is also applicable.

  For example, in the above-described embodiment, the case where the sheet is stored in a cassette having a size specifying mechanism in which the user can specify the size of the sheet with the instruction dial has been described. However, the sheet is stored in a cassette having no size specifying mechanism. In this case, the present invention is applicable. In this case, a sheet of a preset size is usually stored in the cassette of the image forming apparatus.

  In the above embodiment, cassette sheet presence / absence sensors 63a, 63b, 63c, 63d, manual tray paper presence / absence sensor 76, and deck paper presence / absence sensor 75 are arranged as sheet presence / absence detection means. The flag information FLAG may be turned ON by detecting the change in the presence or absence of the sheet material (that is, the change from absence to presence) only by the detection results of these sensors.

  Furthermore, the flag information FLAG may be turned ON by detecting at least one of a designated size change, a cassette open / close change, and a sheet material presence / absence change.

  If it is determined that the length of the sheet calculated by the time when the sheet is detected by the paper feed sensor 506 is longer than the set size, it is determined that the paper is jammed, and the calculated sheet is determined at that time. May be displayed. This makes it possible to display a size error in more detail.

  Further, the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. In addition to the copying machine and the printing apparatus, the image forming apparatus may of course be a facsimile machine having a printing function, a multifunction machine (MFP) having a printing function, a copying function, a scanner function, or the like.

  In the above-described embodiment, an intermediate transfer member is used as the image forming apparatus, and toner images of each color are sequentially transferred onto the intermediate transfer member, and the toner images carried on the intermediate transfer member are collectively transferred to a recording medium. An image forming apparatus that performs transfer is exemplified. However, the present invention is not limited to this transfer method, and an image forming apparatus that uses a recording medium carrier and sequentially superimposes and transfers the toner images of each color carried on the recording medium carrier onto the recording medium. Good.

  In addition, the shapes of the component parts described in the above embodiment, the relative arrangement thereof, and the like should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions, and the scope of the present invention is described above. It is not limited only to what is illustrated.

  In the above-described embodiment, the case where the printing method of the image forming apparatus is an electrophotographic method has been described as an example. However, the present invention is not limited to the electrophotographic method, and an inkjet method, a thermal transfer method, and a thermal method. It can be applied to various printing methods such as electrostatic method and electric discharge destruction method.

  Further, the sheet material is not particularly limited, such as a paper medium, an OHP sheet, a cardboard sheet, and a tab sheet.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 4 Operation part 5 Control unit 21a-21d Cassette 501 CPU
506 Paper feed sensor 507 Paper presence / absence sensor 508 Open / close detection sensor 509 Size switch 512 Transport control unit 513 Size switching determination unit 514 Display control unit 917 Operation display unit

Claims (9)

Image forming means for forming an image on a sheet material;
Sheet storage means for storing the sheet material;
State change detecting means for detecting a state change of the sheet storage means;
Conveying means for conveying the sheet material stored in the sheet storing means to the image forming means;
A sheet detecting means provided in a conveying path for conveying the sheet material, and detecting the presence or absence of the sheet material;
A paper jam determining means for determining a paper jam when the sheet material is detected for a predetermined time by the sheet detecting means;
Display means for displaying the status of the device;
Control means for controlling the display of the display means,
The control means includes
If the sheet material determined to be jammed by the paper jam judging unit is the first sheet after the status change is detected by the status change detecting unit, the sheet set in advance for the display unit A display is made to notify that the size of the material is different from the size of the sheet material stored in the sheet storage means. On the other hand, if it is the second or subsequent sheet, a paper jam has occurred to the display means. An image forming apparatus that performs control so as to perform display for notifying the user. Size specifying means for setting the size of the sheet material stored in the sheet storing means to a specified size;
In the case of the first sheet, the control means is configured such that the size of the sheet material specified by the size specifying means differs from the size of the sheet material stored in the sheet storage means with respect to the display means. The image forming apparatus according to claim 1, wherein display for notification is performed.   The image forming apparatus according to claim 1, wherein the state change detection unit detects a change in opening / closing of the sheet storage unit as the state change.   The image forming apparatus according to claim 2, wherein the state change detection unit detects a change in size designated by the size designation unit as the state change. A sheet presence / absence detection means for detecting whether or not a sheet material is stored in the sheet storage means;
The image forming apparatus according to claim 1, wherein the state change detection unit detects a change in the presence or absence of a sheet material as a result of detection by the sheet presence / absence detection unit as the state change.   The state change detection means includes at least a change in size designated by the size designation means, a change in opening / closing of the sheet storage means, and a change in presence / absence of a sheet material stored in the sheet storage means as the state change. The image forming apparatus according to claim 2, wherein one is detected.   The image forming apparatus according to claim 1, wherein the predetermined time is determined from the set size of the sheet material and a conveyance speed by the conveyance unit.   The paper jam judging unit detects the sheet material for a predetermined time by the sheet detecting unit, and determines that the length of the sheet material calculated by the detected time is longer than the set size. The image forming apparatus according to claim 1, wherein the image forming apparatus determines that a paper jam has occurred. Image forming means for forming an image on a sheet material;
Sheet storage means for storing the sheet material;
Conveying means for conveying the sheet material stored in the sheet storing means to the image forming means;
In a sheet material conveyance control method of an image forming apparatus provided with a display means for displaying the state of the apparatus,
A sheet detection step in which the image forming apparatus detects the presence or absence of the sheet material by a sheet detection unit provided in a conveyance path in which the conveyance unit conveys the sheet material;
A paper jam determining step in which the image forming apparatus determines a paper jam when a sheet material is detected for a predetermined time in the sheet detecting step;
A state change detecting unit for detecting a state change of the sheet storage unit;
When the image forming apparatus is the first sheet after the state change is detected in the state change detection step, the sheet material determined to be in the paper jam determination step is the first sheet after the state change is detected. , Display a notification that the size of the preset sheet material and the size of the sheet material stored in the sheet storage means is different, on the other hand, if it is the second and subsequent sheets, for the display means, And a display control step for controlling to perform a display notifying that a paper jam has occurred. A sheet material conveyance control method for an image forming apparatus.