JP2014109680A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of reducing incorrect copying and clogging of sheets even when the size of the sheets is changed.SOLUTION: An image forming apparatus determines whether a sheet specified by a display unit/operation unit 610 is included in a group determined by a sheet size group detection sensor 50, when determining that the sheet is not included in the group, measures a length in a sheet feeding direction of the sheet with a sheet size measuring sensor 10, and controls an image forming unit to perform image forming operation when the length in the feeding direction of the specified sheet coincides with a measurement result, and controls the image forming unit not to perform image forming operation when the length does not coincide with the measurement result.

Description

  The present invention relates to an image forming apparatus, and more particularly to a configuration for detecting the size of a sheet stored in a paper feed cassette.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multi-function machine that forms an image by an electrophotographic method has a center moving function that automatically moves a processed image of a document to the center of a sheet. In addition, an automatic scaling function that automatically scales the image to be processed according to the size of the sheet, an automatic sheet selection function that automatically detects the size of the document, and automatically selects a sheet that matches the detected size. It has. When forming an image, each of these functions is activated to form an image.

  By the way, when forming an image on a sheet, it is necessary to determine the size of the image to be processed and the size of the sheet before image formation. Conventionally, the sheet size is determined in advance by providing a specific switch corresponding to the size of the sheet stored in the cassette in which the sheet is stored, and outputting from the specific switch when the cassette is mounted on the image forming apparatus. Was done by an electrical signal.

  Here, as a size detection device for detecting the sheet size stored in a cassette having a unique switch, a first sheet size setting associated with a desired sheet size is selected from a plurality of sheet size settings by a selection unit. There is something to select (see Patent Document 1). Thereby, even when a sheet having an arbitrary size different from the sheet size according to various standards is used, an image can be formed on the sheet. By using such a size detection device, it becomes possible to use sheets of various sizes, and the user can easily set an arbitrary sheet size.

  Further, as a size detection device for detecting the sheet size, for example, a sheet width setting unit that sets an edge position in the sheet width direction and a sheet length setting unit that sets an edge position in the sheet length direction are provided. There is a thing (refer patent document 2). The automatic size detection apparatus includes a sheet width detection unit that outputs a first electrical signal corresponding to an edge position in the width direction set by the sheet width setting unit, and a length direction set by the sheet length setting unit. Sheet length detecting means for outputting a second electrical signal corresponding to the edge position is provided.

  The automatic size detection device detects the size based on the first electric signal and the second electric signal. The automatic size detection device detects the sheet size according to the priority order set in advance in the sheet group when a plurality of standard sheets are selected based on the first electric signal and the second electric signal. I do.

Japanese Patent Laid-Open No. 2004-210443 JP-A-6-72562

  By the way, the sheet size used in the conventional image forming apparatus includes a postcard size, A5, A4, A3, B5, B4, and the like. In addition, there are special sizes used in certain countries. As described above, there are various types of sheet sizes used in the image forming apparatus. Furthermore, the user may use a special size sheet independently.

  Here, in the conventional sheet size detection apparatus described above, in order to detect various types of sheet sizes, it is necessary to prepare a large number of sheet feeding cassettes each having a unique switch for each sheet size. As a result, the size of the image forming apparatus itself is increased, and an operation with many cassette replacement operations becomes a complicated device, and there is a problem in terms of manufacturing cost.

  On the other hand, in the case of the size detection apparatus described above, an arbitrary sheet size different from the sheet sizes according to various standards can be set, so that it is not necessary to prepare a large number of paper feed cassettes. However, when the sheets stored in the sheet cassette are changed, the user performs an input operation of sheet information. If the user forgets the input operation, the sheet stored in the sheet cassette is set. Sheet information does not match. As a result, miscopying and sheet jamming may occur.

  Further, in the case of the automatic size detection device, the length and width of the sheet are detected and combined to detect the size of the sheet. However, if the user does not properly set the regulating member, which is the sheet length setting means, at the upstream end of the sheet feeding direction, the sheet is conveyed with a different size from the set sheet, and therefore jamming and skew feeding are repeated. There arises a problem that it occurs.

  Accordingly, the present invention has been made in view of such a situation, and an object of the present invention is to provide an image forming apparatus that can reduce miscopying and sheet jamming even when the sheet size is changed. is there.

  The present invention provides an image forming apparatus, an image forming unit, a sheet storing unit that stores a sheet fed to the image forming unit, and an upstream end in a sheet feeding direction of the sheet stored in the sheet storing unit. Which group of a plurality of groups in which the sheet stored in the sheet storage unit is grouped according to the length in the sheet feeding direction according to the position of the restriction member for restricting the position and the position of the restriction member Determination means for determining whether the sheet is included, input means for inputting a size of a sheet stored in the sheet storage means, and control means for controlling an image forming operation of the image forming unit. The control unit determines whether the sheet input by the input unit is included in the group determined by the determination unit, and determines that the sheet is not included in the group. And it is characterized in Rukoto.

  When it is determined that the specified sheet is not included in the group determined by the determination unit as in the present invention, the sheet length is measured, and the measurement result matches the specified sheet length. By performing the image forming operation, miscopying and sheet jamming can be reduced even when the sheet size is changed.

1 is a diagram illustrating an overall configuration of a laser beam printer (LBP) that is an example of an image forming apparatus according to a first embodiment of the present invention. FIG. 3 illustrates a configuration of a paper feeding cassette provided in the laser beam printer. The chart which shows the relationship between the rear end regulation board provided in the said laser beam printer, ON / OFF of switch SW1, SW2, and the sheet | seat grouped. FIG. 3 is a control block diagram of the laser beam printer. 6 is a flowchart showing sheet size determination control according to the present embodiment. 9 is a flowchart showing sheet size determination control according to the second embodiment of the present invention. 10 is a flowchart showing sheet size determination control according to a third embodiment of the present invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an overall configuration of a laser beam printer (LBP) which is an example of an image forming apparatus according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a laser beam printer, and 1A denotes a laser beam printer main body (hereinafter referred to as a printer main body). The printer main body 1A includes an image forming unit 1B, and a sheet feeding device 1C for feeding the sheets S stacked and stored in the paper feed cassette 2 to the image forming unit 1B is provided below the printer main body 1A. It has been.

  Here, the image forming unit 1B includes a photosensitive drum 12a, a charger 12b, a developing sleeve 12c, and the like. Further, a laser scanner 13 is provided as exposure means for exposing the surface of the photosensitive drum 12a to form an electrostatic latent image on the photosensitive drum 12a. The image forming unit 1B is in contact with the photosensitive drum 12a, and includes a transfer roller 12d that forms a transfer unit together with the photosensitive drum 12a, a fixing unit 14 that fixes the toner image transferred by the transfer unit to the sheet S, and the like. I have.

  The sheet feeding apparatus 1 </ b> C includes a pickup roller 3 that is a sheet feeding unit that feeds sheets S stacked in a sheet feeding cassette 2 that is a sheet storage unit from the uppermost side. Further, the sheet feeding apparatus 1C includes a feed roller 4a that rotates in the sheet conveyance direction and a retard roller 4b that forms a separation nip portion that presses against the feed roller 4a and separates the sheets one by one from the feed roller 4a. And.

  In FIG. 1, reference numeral 10 denotes a sheet size measurement sensor disposed upstream of the registration roller pair 11. The sheet size measurement sensor 10 is located at the position where the light shielding plate shields the photo interrupter by the contact of the sheet. Detect the presence of a sheet. Further, the CPU 501 shown in FIG. 4 to be described later can actually measure the sheet feeding direction length (sheet size) of the conveyed sheet S from the ON time of the sheet size measuring sensor 10.

  Next, an image forming operation in the laser beam printer 1 will be described. When the image forming operation is started, first, the pickup roller 3 of the sheet feeding device 1C rotates to feed the uppermost sheet S1 on the sheet feeding cassette 2. The sheet S1 sent out by the pickup roller 3 is separated and conveyed by the separation roller pair 4a and 4b, then conveyed to the stopped registration roller pair 11, and the leading edge is pressed to align the leading edge ( (Skew correction) is performed.

  Next, based on a signal from the sheet size measurement sensor 10, laser light is emitted from the laser scanner 13 to the photosensitive drum 12a whose surface is charged by the charger 12b. Thereby, an electrostatic latent image is formed on the photosensitive drum. Thereafter, the electrostatic latent image is developed as a toner image by supplying toner that has been appropriately charged with the rotation of the developing sleeve 12c onto the photosensitive drum 12a and adhering to the electrostatic latent image. Visualized.

  Next, the sheet S1 is conveyed to the transfer unit by the registration roller pair 11 so as to be synchronized with the image formed on the photoconductor drum 12a in the image forming unit 1B, and the image on the photoconductor drum 12a is transferred to the sheet by the transfer roller 12d. Transferred to S1. Next, the sheet S1 to which the toner image has been transferred is conveyed to the fixing unit 14, and the unfixed toner image is heated and pressurized to be fixed on the sheet surface. The sheet S1 after the toner image is fixed is discharged onto the paper discharge tray 19.

  FIG. 2 is a diagram showing the configuration of the paper feed cassette 2. In the present embodiment, the maximum sheet size that can be stored in the sheet feeding cassette 2 is A3 (sub-scanning length: 420 mm). In FIG. 2, 202 a and 202 b are provided on the sheet stacking portion 201 of the sheet feeding cassette 2 so as to be movable in the width direction orthogonal to the sheet feeding direction, and restrict side positions of the sheet S in the width direction. It is. Reference numeral 204 denotes a rear end regulating plate that is provided in the sheet stacking unit 201 so as to be movable in the sheet feeding direction and serves as a regulating member that regulates the position of the upstream end of the sheet S in the sheet feeding direction. The rear end regulating plate 204 is connected to a sub-scanning detection unit 206 via sub-scanning detection guides 205a and 205b.

  Here, the rear end regulating plate 204 is positioned at a position indicated by 204a for regulating a group of sheets having a sub-scanning length (length in the sheet feeding direction) of 335 mm or more, and a sheet S of a group having a sub-scanning length of 232 mm to 335 mm. It can move to the position of 204b to be regulated. Further, the rear end regulating plate 204 is movable to a position 204c that regulates a group of sheets whose sub-scanning length is 232 mm or less. That is, in the present embodiment, the trailing edge regulating plate 204 is set to a position that regulates the trailing edge positions of the three groups of sheets S having different lengths in the sheet feeding direction.

  The sub-scanning detection unit 206 is provided with switches SW1 and SW2. Then, when the sub-scanning detection guides 205a and 205b move according to the position of the rear end regulating plate 204, the switches SW1 and SW2 are in different detection states. FIG. 3 shows ON / OFF of the switches SW1, SW2 according to the position of the rear end regulating plate 204.

  That is, when the switches SW1 and SW2 are (1, 0), it is indicated that one sheet S of a group having a sub-scanning length of 335 mm or more is stored in the sheet feeding cassette. When the switches SW1 and SW2 are (0, 1), it indicates that one sheet of a group having a sub-scan length of 232 mm to less than 335 mm is stored. Further, when the switches SW1 and SW2 are (1, 1), it indicates that one sheet of the group whose sub-scanning length is less than 232 mm is stored. When the switches SW1 and SW2 are (0, 0), the cassette is not present.

  The switches SW1 and SW2 constitute a sheet size group detection sensor 50 connected to a CPU 501 shown in FIG. 4 to be described later, and ON and OFF of the switches SW1 and SW2 are input to the CPU 501. Here, for example, as the sheet S of the group whose sub-scanning length is 335 mm or more, there are A3, 11 × 17, B4, LGL, and the like. Therefore, when the switches SW1 and SW2 are (1, 0), the CPU 501 determines that any one sheet of A3, 11x17, B4, LGL, and the like is stored in the sheet cassette 2. Can do. That is, the CPU 501 can group the sheets stored in the sheet feeding cassette 2 based on the signal from the sheet size group detection sensor 50.

  FIG. 4 is a control block diagram of the laser beam printer according to the present embodiment. In FIG. 4, reference numeral 501 denotes a CPU (engine control unit) as control means. The CPU 501 includes a ROM (read-only memory) 502 that stores a control procedure (control program), and a RAM (random access memory) 503 that is a main storage device used as a storage area for input data or a work storage area. Yes. The ROM 502 serving as the storage means stores a table indicating the relationship between the rear end regulating plate shown in FIG. 3 described above, ON / OFF of the switches SW1 and SW2, and the grouped sheets.

  The CPU 501 includes an I / O (input / output control unit) 504 for inputting a control signal output to a load such as a main motor and a sensor signal. A sheet size measurement sensor 10 is connected to the CPU 501 via the I / O 504 as a measuring unit that measures the length of the sheet S in the sheet feeding direction.

  Further, the CPU 501 has a determination unit for determining which of the plurality of groups the sheets stored in the sheet feeding cassette 2 are grouped according to the length in the sheet feeding direction. The sheet size group detection sensor 50 is connected. Further, the CPU 501 is connected with a sheet presence / absence detection sensor 60 which is a detection means for detecting the presence / absence of a sheet in the sheet feeding cassette 2, a controller 600 for controlling various operations of each part of the laser beam printer 1 via an interface IF, and the like. Has been.

  The controller 600 includes a keyboard for operating the laser beam printer 1, image formation settings, paper feed cassette size settings, a display panel (not shown) that displays setting information, and the like. / The operation unit 610 is connected by a bus or the like. Then, the operator gives various commands related to image formation, such as a command for image formation to the CPU 501 via the controller 600 by the operation panel of the display unit / operation unit 610. In addition, the operator designates the sheet size using the display / operation unit 610 which is a designation unit for designating the size of the sheet on which the image is formed.

  By the way, the CPU 501 uses the table stored in the ROM 502 to check whether the sheet size detected (determined) by the sheet size group detection sensor 50 matches the sheet size designated by the user in the display / operation unit 610. Determine. Alternatively, it is determined whether the sheet size group detected (determined) by the sheet size group detection sensor 50 includes the sheet size designated by the user in the display unit / operation unit 610.

  Here, if the detected sheet size does not match the designated sheet size, or if the designated sheet size is not included in the sheet size group, the sheet feeding direction length of the sheet S is set. Actual measurement is performed by the sheet size measurement sensor 10. Then, the actual measured sheet length is compared with the length of the specified sheet size. If the actual measured sheet length is the same as the sheet length specified by the user, the image is displayed on the sheet as it is. Can continue to be printed.

  If the sheet size group does not match the designated sheet size and the actually measured sheet length is the same as the sheet length designated by the user, the position of the trailing edge regulating plate 204 is Judge that it is not appropriate. Then, after the printing is completed, the CPU 501 displays on the display unit / operation unit 610 a display prompting the user to confirm the setting position of the rear end regulating plate 204.

  Next, the sheet size determination control according to the present embodiment will be described with reference to the flowchart shown in FIG. When a print instruction for image formation from the controller 600 is sent via the interface IF (Y in S701), the CPU 501 starts printing (S702). As a result, the pickup roller 3 rotates and the uppermost sheet S1 on the sheet feeding cassette 2 is sent out.

  Also, the CPU 501 determines whether or not the sheet size designated by the user on the display / operation unit 610 matches the sheet size group in the sheet cassette detected by the sheet size group detection sensor 50. Determine. That is, it is determined whether the size designation and the size group detected by the sheet size group detection sensor 50 match or do not match (S703).

  Here, when the sheet size does not match (Y in S703), the length of the sheet S in the sheet feeding direction is measured by the sheet size measurement sensor 10 (S704), and the actually measured size length by the measurement and the size specified by the user are measured. Compare the sheet length. As a result of this comparison, when the actually measured sheet length matches the designated sheet length (Y in S705), printing is continued (S706).

  Thereafter, when printing is completed (Y in S707), a state confirmation request for confirming the state of the rear end regulating plate 204 of the sheet feeding cassette 2 is displayed on the display panel of the display unit / operation unit 610 (S708). When the sheet sizes match, that is, when the sheet sizes do not match (N in S703), printing is continued. As a result of comparison, if the measured sheet length (measured size length) and the sheet length specified by the user do not match (N in S705), there is a risk of miscopying or sheet jamming. Printing is interrupted (S709).

  As described above, in the present embodiment, the CPU 501 determines whether the sheet specified by the display unit / operation unit 610 is included in the group determined by the sheet size group detection sensor 50. If it is determined that the sheet is not included in the group, the sheet size measurement sensor 10 measures the length of the sheet in the sheet feeding direction and the measurement result matches the designated sheet feeding direction length. Controls the image forming unit 1B to perform the image forming operation. As a result, when the sheet size is changed, miscopying and sheet jamming can be reduced even when the trailing edge regulating plate 204 is not properly set.

  In the above description, when the print job (image forming job) is completed, the status confirmation request is displayed. However, the present invention is not limited to this. For example, even before the print job is completed, if there is no sheet in the sheet feeding cassette (in the sheet storage unit), a status confirmation request may be displayed on the display panel of the display unit / operation unit 610.

  Next, even before such a print job is completed, when there is no sheet in the sheet feeding cassette, a status confirmation request is displayed on the display panel of the display unit / operation unit 610. Embodiments will be described. FIG. 6 is a flowchart showing sheet size determination control in the image forming apparatus according to the present embodiment.

  When a print instruction for image formation from the controller 600 is sent via the interface IF (Y in S801), the CPU 501 starts printing (S802). As a result, the pickup roller 3 rotates and the uppermost sheet S1 on the sheet feeding cassette 2 is sent out.

  Also, the CPU 501 determines whether or not the sheet size designated by the user on the display / operation unit 610 matches the sheet size group in the sheet cassette detected by the sheet size group detection sensor 50. Determine. That is, it is determined whether the size designation and the size group detected by the sheet size group detection sensor 50 match or do not match (S803).

  Here, in the case of the sheet size mismatch state (Y in S803), the sheet feeding direction length of the sheet S is measured by the sheet size measurement sensor 10 (S804), and the actually measured size length by the measurement and the specified size by the user. Compare the sheet length. As a result of this comparison, when the actually measured sheet length matches the designated sheet length (Y in S805), printing is continued (S806).

  After this, even before printing is completed, if the sheet presence / absence detection sensor 60 detects the absence of paper in the paper cassette 2 (Y in S807), a state confirmation request for confirming the state of the rear end regulating plate 204 of the paper cassette 2 Is displayed on the display panel of the display / operation unit 610 (S808). When the sheet sizes match, that is, when the sheet sizes do not match (N in S803), printing is continued. As a result of comparison, if the measured sheet length (actually measured size length) does not match the sheet length specified by the user (N in S805), there is a risk of miscopying or sheet jamming. Printing is interrupted (S809).

  As described above, in the present embodiment as well, as in the first embodiment described above, when the sheet size is changed, even if the trailing end regulating plate 204 is not set appropriately, miscopying or sheet jamming is caused. Can be reduced.

  Next, a third embodiment of the present invention will be described. FIG. 7 is a flowchart in the image forming apparatus according to the present embodiment. In the present embodiment, when the sheet size designation and the sheet size group detected by the sheet size group detection sensor 50 do not match, a sheet size mismatch alarm notification is performed.

  If the actually measured sheet length is the same as the sheet length designated by the user, the sheet size mismatch alarm notification is canceled. In addition, the number of times the sheet size mismatch notification is canceled is counted, and when the number of cancellation of the sheet size mismatch notification reaches a predetermined number, it is determined that the sheet size group detection sensor 50 has failed. A display (warning) for prompting the user to be present is performed.

  Next, the sheet size determination control according to the present embodiment will be described with reference to the flowchart shown in FIG. When a print instruction for image formation from the controller 600 is sent via the interface IF (Y in S901), the CPU 501 starts printing (S902). As a result, the pickup roller 3 rotates and the uppermost sheet S1 on the sheet feeding cassette 2 is sent out.

  Also, the CPU 501 determines whether or not the sheet size designated by the user on the display / operation unit 610 matches the sheet size group in the sheet cassette detected by the sheet size group detection sensor 50. Determine. That is, it is determined whether the size designation and the size group detected by the sheet size group detection sensor 50 match or do not match (S903).

  If the sheet size does not match (Y in S903), a sheet size mismatch alarm is notified and the length of the sheet S in the sheet feeding direction is measured (S904). Compare the sheet length of the specified size. As a result of this comparison, when the actually measured sheet length matches the designated sheet length (Y in S905), the sheet size mismatch alarm notification is stopped (S906) and printing is continued. If the sheet sizes match (N in S903), the state confirmation request is not displayed and printing is continued. As a result of comparison, if the actually measured sheet length does not match the sheet length specified by the user (N in S905), the printing is interrupted (S911).

  By the way, in this embodiment, when printing is completed (Y in S907), the CPU 501 measures the number of times the sheet size mismatch notification is canceled at the first printing after changing the sheet size, and the number of times of measurement is predetermined. It is determined whether the number of times has been reached (S908). If the predetermined number of times has not been reached (N in S908), a state confirmation request for confirming the state of the rear end regulating plate 204 of the sheet feeding cassette 2 is displayed on the display panel of the display unit / operation unit 610. (S909). If the predetermined number of times has been reached (Y in S908), the CPU 501 determines that the sheet size group detection sensor 50 has failed, and displays the sheet size group detection sensor failure on the display panel (S910).

  Thus, in the present embodiment, the failure of the sheet size group detection sensor 50 is detected by measuring the number of times the sheet size mismatch notification is canceled and determining whether the number of times of measurement has reached a predetermined number. Can do. As a result, it is possible to reduce miscopying and sheet jamming based on the failure of the sheet size group detection sensor 50.

DESCRIPTION OF SYMBOLS 1 ... Laser beam printer, 1A ... Laser beam printer main body, 1B ... Image formation part, 2 ... Paper feed cassette, 10 ... Sheet size measurement sensor, 50 ... Sheet size group detection sensor, 60 ... Sheet presence detection sensor, 204 ... After End regulating plate, 501... CPU, 610... Display / operation unit, S... Sheet, SW1, SW2.

Claims (9)

An image forming unit;
Sheet storage means for storing a sheet fed to the image forming unit;
A regulating member that regulates the position of the upstream end of the sheet stored in the sheet storing means in the sheet feeding direction;
According to the position of the restricting member, it is determined which of the plurality of groups the sheets stored in the sheet storage unit are grouped according to the length in the sheet feeding direction. Determination means for,
Input means for inputting the size of the sheet stored in the sheet storage means;
Control means for controlling the image forming operation of the image forming unit,
The control unit determines whether the sheet input by the input unit is included in the group determined by the determination unit, and warns when it is determined that the sheet is not included in the group. Forming equipment. When the sheet is fed, a measuring means for measuring the length of the fed sheet in the sheet feeding direction is provided,
When the control unit determines that the sheet is not included in the group and the sheet stored in the sheet storage unit is fed, the measuring unit measures the sheet feeding direction length of the sheet. When the measurement result and the length of the sheet fed in the input unit match, the image forming operation is performed, and when they do not match, the image forming unit is controlled not to perform the image forming operation. The image forming apparatus according to claim 1. When the sheet is fed, a measuring means for measuring the length of the fed sheet in the sheet feeding direction is provided,
When the control unit determines that the sheet is not included in the group and the sheet stored in the sheet storage unit is fed, the measuring unit measures the sheet feeding direction length of the sheet. 2. The image forming apparatus according to claim 1, wherein when the measurement result and the length of the sheet input in the input unit do not coincide with each other, the change of the sheet input in the input unit is urged. Display means for displaying the position of the restricting member so as to change the sheet input by the input means to a position included in the group determined by the determination means;
The control means controls the display means to perform a display for changing the position of the restricting member when the measurement result and the input sheet length in the feeding direction coincide with each other. Item 4. The image forming apparatus according to Item 2 or 3.   The image forming apparatus according to claim 4, wherein the control unit controls the display unit to perform a display for changing a position of the restriction member after the image forming job is completed. A detection means for detecting the presence or absence of a sheet in the sheet storage means,
5. The control unit according to claim 4, wherein when the detection unit detects that there is no sheet in the sheet storage unit, the control unit controls the display unit to perform a display for changing the position of the restriction member. Image forming apparatus.   When the control unit determines that the input sheet is not included in the group, the control unit displays that the sheet size does not match, and the measurement result and the input sheet feeding direction length match. The image forming apparatus according to claim 4, wherein the display unit is controlled to release the display when the display is canceled.   The image forming apparatus according to claim 7, wherein the control unit measures the number of times the display is canceled, and determines that the determination unit is out of order when the measured number reaches a predetermined number. A storage unit including a table for determining which group the input sheet is included in, based on a sheet feeding direction length of the sheet input by the input unit;
9. The image forming apparatus according to claim 2, wherein the control unit determines in which group the sheet input by the input unit is included, based on the table.

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