JP2018030665A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus which allows a user to easily adjust the position of a sheet set on a tray when performing printing on a long rectangular-shaped sheet, and can suppress the occurrence of skew and lateral deviation.SOLUTION: An image forming apparatus includes detection means which detects skew and lateral deviation of a sheet in a conveyance path from a sheet support part to an image forming part. A control part causes the detection means to detect skew and lateral deviation of the sheet while conveying the sheet by driving a sheet conveyance part, calculates a correction amount for correcting skew and lateral deviation on the basis of the detection result, converts the correction amount into a scale amount of a position adjustment scale and displays it on an information display part.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus including a sheet conveying unit that feeds a sheet, and in particular, when a user tries to form an image on a long sheet, a simple operation is performed on a sheet position set in a sheet storage unit. It is related with the technology adjusted in

  In recent years, image forming apparatuses such as printers and copiers have been required to be compatible with various types of sheets. For example, there is an increasing demand for printing on a long rectangular sheet for use in a catalog or book cover.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a configuration including an expansion sheet tray and a movable side guide as a sheet supply device for supplying a so-called long sheet to a print engine of an image forming apparatus.

  Japanese Patent Application Laid-Open No. 2005-228561 discloses an active registration type apparatus that detects skew of a sheet supplied to a print engine of an image forming apparatus and drives a skew correction roller based on detection information.

JP 2003-267561 A JP 2008-254856 A

  When the sheet is set on the manual feed or cassette type sheet tray, if the sheet is shifted from an appropriate position, lateral shift and skew are likely to occur in the path for feeding the sheet to the print engine. When a lateral shift or skew of the sheet occurs, the image printed on the sheet shifts from the position where it should be printed. In particular, in the field of commercial printing such as catalogs and book covers, since high accuracy is required for the printing position, it is inconvenient for the sheet to be laterally shifted or skewed in the feeding path.

  The movable side guide of Patent Document 1 allows the side guide to be moved in accordance with the sheet width in order to prevent play between the side guide and the sheet when a long sheet is set on the tray. The seat is regulated. However, Japanese Patent Application Laid-Open No. H10-228707 does not sufficiently examine the point that the position of the side guide should be adjusted appropriately in order to prevent the sheet from being laterally shifted or skewed in the feeding path.

  The apparatus of Patent Document 2 is excellent in that the registration is automatically corrected in the feeding path without bothering the user, but is realistic in setting the shape and material of the skew feeding correction roller, the printing speed, and the like. Because of these limitations, the range that can be automatically corrected was not infinitely wide. Therefore, the amount of deviation of the sheet set on the sheet tray from the appropriate position may be within the range that can be corrected by the skew feeding correction roller, but it is out of the range that can be corrected. In some cases, the skew and lateral deviation of the sheet could not be corrected.

  Therefore, it has been demanded that the user can easily adjust the position of the sheet to be set on the tray and can suppress the occurrence of skew and lateral shift.

  The present invention provides a sheet support unit that supports a sheet, an image forming unit that forms an image on a sheet, a sheet transport unit that transports a sheet from the sheet support unit to the image forming unit, and an information display unit that displays information And a control unit that controls display of the information display unit, wherein the sheet support unit controls a position of a sheet supported by the sheet support unit, and a position of the sheet position control member. A position adjusting unit to be adjusted, an index indicating the position of the sheet position regulating member, and a position adjusting scale provided corresponding to the index, the position adjusting unit being a direction orthogonal to the sheet conveying direction; The sheet position regulating unit can be adjusted with respect to an angle with respect to the sheet conveyance direction, and the sheet conveyance unit is configured to perform skew feeding of a sheet conveyed during conveyance from the sheet support unit to the image forming unit. Detection means for detecting a shift is provided, and the control unit displays on the information display unit the number of scales of the position adjustment scale for adjusting the position of the sheet position regulating member based on detection by the detection means. An image forming apparatus characterized by that.

  According to the present invention, the user can easily adjust the position of the sheet to be set on the tray, and the occurrence of skew and lateral shift can be suppressed.

1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. The block diagram which shows the connection of a controller and each part of an apparatus. The top view of the sheet tray of a first embodiment. The perspective view of a sheet tray, a resist part, and a photosensitive drum. The top view of a sheet tray, a resist part, and a photosensitive drum. The top view of a resist part. The top view of the display screen on which information was displayed. The flowchart which shows the sequence of test mode. FIG. 6 is a plan view showing a sheet print image in a test mode. The flowchart which shows the sequence of registration mode. The top view of the sheet tray of 2nd embodiment. The perspective view and partial sectional view of a cassette type sheet tray of a third embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[First embodiment]
FIG. 1 is a schematic configuration diagram of an image forming apparatus including a sheet conveying device according to the first embodiment of the present invention.

  In FIG. 1, reference numeral 1000 denotes a printer. The printer 1000 includes a printer main body 1001, a scanner 2000 and an operation unit 3000 arranged on the printer main body 1001. Hereinafter, the configuration and operation will be described in the order of the scanner 2000, the operation unit 3000, and the printer main body 1001.

(Scanner)
A scanner 2000 that reads a document includes a scanning optical system light source 201, a platen glass 202, a document pressure plate 203 that opens and closes, and a feeder 250. An image reading unit 2001 including a lens 204, a light receiving element (photoelectric conversion element) 205, an image processing unit 206, a memory unit 208 for storing image processing signals processed by the image processing unit 206, and the like. I have.

  When reading the original, the original (not shown) placed on the platen glass 202 is read by irradiating light with the scanning optical system light source 201. The read document image is processed by the image processing unit 206, converted into an electrically encoded electrical signal 207, and transmitted to a laser scanner 111 a serving as image forming means provided in the printer body. Note that the image information processed and encoded by the image processing unit 206 can be temporarily stored in the memory unit 208 and transmitted to the laser scanner 111a as required by a signal from the controller 120.

(Operation section)
The operation unit 3000 includes an input unit 302 for inputting various instructions for the user to operate the printer 1000, and a display panel 301 as an information display unit for displaying information to the user.

  The input unit 302 includes keys for the user to specify an operation mode of the printer, a button for instructing the start of a printing operation, a numeric keypad for specifying the number of prints, and the like. As the display panel 301 that is an information display unit, an LCD panel or an OLED panel with good visibility is preferably used.

  In addition, although the input unit 302 and the display panel 301 are provided separately in the operation unit 3000 in FIG. 1, the present invention is not necessarily limited to this example. For example, a touch panel in which a display panel and an input unit are integrated may be used. The position of the operation unit 3000 is above the scanner 2000 in the image forming apparatus of FIG. 1, but is not limited to this example, and may be installed at a different position as long as it is easy for the user to operate. Good.

(Printer body)
The printer main body 1001 includes a sheet feeding device 1002 that supports sheets and feeds the sheets one by one, an image forming unit 1003 that forms an image on a sheet fed by the sheet feeding device 1002, and a controller 120. Yes.

  A controller 120 as a control unit of the printer 1000 controls the operation of each unit of the printer 1000.

  The sheet feeding apparatus 1002 includes a manual sheet tray 300 serving as a sheet support portion, a cassette sheet tray 100, and a pickup roller 101, a feed roller 102, and a retard roller 103 provided in correspondence therewith. A pair of the feed roller 102 and the retard roller 103 constitutes a separation unit that separates the sheets S one by one. That is, the sheets S in the manual sheet tray 300 or the cassette sheet tray 100 are separated and fed one by one by the action of the pickup roller 101 that moves up and down / rotates at a predetermined timing and the separation unit. Yes.

  The sheet feeding apparatus 1002 further includes a registration unit 1 that is a sheet conveyance unit.

  The sheet S fed from the manual type sheet tray 300 or the cassette type sheet tray 100 which is a sheet supporting unit is guided to the image forming unit 1003 via the registration unit 1.

  The manual sheet tray 300 and the resist unit 1 will be described in detail later.

  The image forming unit 1003 is of an electrophotographic type, and includes a photosensitive drum 112 as an image carrier, a laser scanner 111a as an image writing unit, a developing device 114, a transfer charger 115, a separation charger 116, and the like. .

  During image formation, when the registration sensor 131 detects that the sheet S has passed through the registration unit 1, the controller 120, which is a control unit, adjusts the timing based on this detection signal and irradiates the laser scanner 111a with laser light. Instruct the start.

  Then, the laser beam from the laser scanner 111a is folded back by the mirror 113 and applied to the exposure position 112a on the photosensitive drum rotating in the clockwise direction, whereby a latent image is formed on the photosensitive drum. Further, the latent image formed on the photosensitive drum in this way is thereafter visualized as a toner image by the developing device 114.

  The toner image on the photosensitive drum that has been visualized in this manner is then transferred to the sheet S by the transfer charger 115 in the transfer unit 112b.

  The sheet S to which the toner image has been transferred is electrostatically separated from the photosensitive drum 112 by the separation charger 116, and then conveyed to the fixing device 118 by the conveyance belt 117, and the toner image is fixed. It is discharged by 119. Thereby, the image formation on the sheet is completed.

  As shown in FIG. 2, the controller 120, which is a control unit that controls the operation of each unit of the printer 1000, includes a CPU, a RAM that temporarily stores data, a ROM that stores a control program, and an external communication unit. An input / output circuit and the like are included. As shown in FIG. 2, the controller 120 exchanges signals with each unit of the apparatus and controls each unit.

(Sheet tray)
Next, the manual sheet tray 300 that is a sheet support portion will be described. FIG. 3 is a plan view showing a schematic configuration of the manual sheet tray 300, but illustrations of mechanisms such as the pickup roller 101, the feed roller 102, and the retard roller 103 are omitted. Reference numeral 320 in the figure denotes a base of the manual sheet tray 300. A side restricting plate 311 and a side restricting plate 312 as sheet position restricting members that restrict the set position of the sheet S are fixed to the base 320. The side regulating plate 311 and the side regulating plate 312 are fixed to the base body 320 via an adjustment knob 313 and an adjustment knob 314, which are position adjustment units, respectively. If the user loosens the adjustment knob, the side regulating plates 311 and 312 are fixed. Can be moved to adjust its position and angle.

  The side regulating plate 312 is provided with a pointer 315 and a pointer 316 along the longitudinal direction (X direction) of the sheet S. The pointer 315 and the pointer 316 are provided at positions separated from the sheet leading edge position when the sheet S is set by a distance of L1 and L2 on the downstream side in the sheet conveying direction.

  The base 320 is provided with a scale 317 and a scale 318 as position adjustment scales along the sheet conveying direction, corresponding to the pointer 315 and the needle 316 as indexes. A scale 317 and a scale 318 are scales indicating distances in a direction orthogonal to the sheet conveying direction. This is for the convenience of the user adjusting the positions and angles of the side regulating plates 311 and 312 when a test mode described later is executed.

  Further, in order to make it easy for the user to distinguish between the pointer 315 and the pointer 316, in the vicinity of the pointers on the side regulating plate 312, indicators 321 A and B are attached to the pointers, respectively.

  In addition, in the vicinity of the scale 317 and the scale 318 of the base 320, a mark 319 indicating the adjustment direction is attached to the scale.

  The pointers, scales, signs, and marks are not limited to the example shown in FIG. 3 as long as they are easily visible to the user. The pointers and scales are not limited to the example provided at only two locations along the sheet conveyance direction, and a plurality of points and scales may be provided.

(Registration part)
Next, the registration unit 1 that is a sheet conveyance unit will be described. The registration unit 1 is a part that conveys the sheet S fed from the manual sheet tray 300 or the cassette sheet tray 100 to the image forming unit 1003. As will be described later, the controller 120 can change the sheet conveying operation in the registration unit 1 depending on the test mode or the registration mode.

  FIG. 4 is a perspective view showing a schematic configuration of the resist unit 1. FIG. 5 is a plan view showing a schematic configuration of the resist portion 1 from above.

  In the drawing, a manual sheet tray 300 storing sheets S is shown on the right side of the resist unit 1, and a photosensitive drum 112 of the image forming unit 1003 is shown on the left side of the resist unit 1. The sheet S is conveyed from right to left in the figure. The Y direction in the figure indicates the direction parallel to the image bearing surface of the photosensitive drum 112 or the axis of the photosensitive drum 112. In addition, since the sheet | seat with a long length is often set to the manual feed type sheet | seat tray 300, the example was shown, However, The cassette type sheet | seat tray 100 may be sufficient like 3rd embodiment mentioned later.

  The registration unit 1 includes a first skew correction driving roller 21a, a first skew correction driven roller 21b, a second skew correction driving roller 22a, a second skew correction driven roller 22b, two registration driving rollers 30a, A resist driven roller 30b is provided. Each drive roller and driven roller are pressed against each other by a pressure spring (not shown), and the sheet S is conveyed therebetween.

  In the following description, the first skew correction driving roller 21a and the first skew correction driven roller 21b are grouped as a first skew correction roller pair 21 and a second skew correction drive roller 22a and a second skew. The set of correction driven rollers 22b may be referred to as a second skew correction roller pair 22. In addition, the two pairs of the registration driving roller 30 a and the registration driven roller 30 b may be collectively referred to as a registration roller pair 30.

  The skew correction motor 23 rotates the first skew correction drive roller 21a, and the skew correction motor 24 rotates the second skew correction drive roller 22a independently. The registration motor 31 rotates the two registration driving rollers 30a in conjunction with each other. The registration shift motor 33 moves the registration roller pair 30 in the Y direction, that is, in a direction parallel to the image carrying surface of the photosensitive drum 112.

  A start sensor 27a for detecting the start timing of the skew correction motor 23 is provided upstream of the first skew correction roller pair 21 in the sheet conveyance direction. Similarly, a start sensor 27b for detecting the start timing of the skew correction motor 24 is provided upstream of the second skew correction roller pair 22 in the sheet conveyance direction. The activation sensor 27a and the activation sensor 27b are arranged along the Y direction.

  With respect to the first skew correction roller pair 21 and the second skew correction roller pair 22, on the downstream side in the sheet conveyance direction, a skew detection sensor 28a and a skew detection sensor 28b for detecting the skew of the sheet S. Is provided. The skew detection sensor 28a and the skew detection sensor 28b are arranged along the Y direction.

  A lateral registration sensor 35 for detecting the shift amount of the sheet S in the Y direction is provided downstream of the skew detection sensor 28a and the skew detection sensor 28b in the sheet conveyance direction. As the lateral registration sensor 35, for example, a linear CCD sensor installed along the Y direction is used.

  A registration sensor 131 is provided downstream of the registration roller pair 30, and the controller 120 can detect that the sheet S has reached this position.

  As will be described later, when normal image formation is performed, the controller 120 causes the printer 1000 to operate in the registration mode. That is, the controller 120 independently controls the rotational speeds of the first skew correction roller pair 21 and the second skew correction roller pair 22 of the registration unit 1 to correct sheet skew. Further, the controller 120 corrects the lateral shift of the sheet by driving the registration shift motor 33 and moving the registration roller pair 30 along the Y-axis direction, that is, in a direction parallel to the image carrying surface of the photosensitive drum 112.

  On the other hand, when a test mode to be described later is executed, the controller 120 conveys the sheet without automatically correcting sheet registration (skew and lateral deviation), and sets the amount of skew and lateral deviation of the sheet to the registration unit 1. Measured by the sensor inside. The controller 120 displays information on the display panel 301 for the user to easily adjust the position and angle of the side regulating plates 311 and 312 of the manual sheet tray 300 based on the measurement result. Here, the skew means that the side of the sheet that should be parallel to the sheet conveyance direction is inclined at a predetermined angle with respect to the sheet conveyance direction. When the skew of the sheet occurs, an image formed on the sheet is formed inclined with respect to the sheet.

  Further, the lateral deviation means that the actual center position of the sheet is deviated from the ideal sheet center position in a direction orthogonal to the sheet conveyance direction. When a lateral shift occurs, an image formed on the sheet is shifted in a direction perpendicular to the sheet conveyance direction.

  Next, the test mode and the registration mode will be described in order.

(Test mode)
Before printing on a sheet, the user causes the printer 1000 to execute a test mode in order to check whether or not the position and angle of the side regulating plates 311 and 312 of the manual sheet tray 300 need to be adjusted. Can do. In particular, when printing a long sheet, it is preferable to execute the test mode because the position and angle of the side regulating plates 311 and 312 greatly affect the skew and lateral displacement of the sheet. In the present embodiment, the skew detection sensor 28a, the skew detection sensor 28b, and the lateral registration sensor 35 constitute detection means for detecting skew and lateral deviation of the sheet.

  The test mode will be described with reference to FIGS.

  FIG. 8 is a flowchart showing an operation sequence in the test mode. Each operation (step) shown in the flowchart of FIG. 8 is realized by the CPU of the controller 120 executing a control program stored in the ROM.

  When receiving the test mode execution instruction, the controller 120 starts the test mode (S1). The sheet feeding device 1002 starts feeding the sheet S set on the manual sheet tray 300 (S2). When the sheet S is fed to the registration unit 1 shown in FIG. 4, the leading edge of the sheet S reaches the activation sensor 27a and the activation sensor 27b. When the start sensor 27a and the start sensor 27b detect the leading edge of the sheet S, the controller 120 drives the skew correction motor 23 and the skew correction motor 24 to convey the sheet S in the downstream direction. At this time, the controller 120 causes the first skew correction driving roller 21a and the second skew correction driving roller 22a to rotate at a constant speed by the skew correction motor 23 and the skew correction motor 24, so that the skew is automatically corrected. There is nothing (S3).

  When the sheet reaches the position indicated by S1 in FIG. 5, the leading edge of the sheet is detected by the skew detection sensor 28a and the skew detection sensor 28b, and a detection signal is transmitted to the controller 120. Since the skew detection sensor 28a and the skew detection sensor 28b are arranged in parallel with the Y direction, the timing of the detection signal is shifted when the sheet is skewed in the middle of conveyance. The controller 120 calculates the skew amount, that is, the angle θ in FIG. 5 based on the detection signal timing shift and the sheet conveyance speed (the peripheral speed of the skew correction roller). The angle θ indicates an angle with respect to an ideal sheet conveyance direction. An ideal sheet conveyance direction is a direction perpendicular to the Y direction.

  As shown in FIG. 6, the lateral registration sensor 35 detects the lateral edge position of the sheet at the position where the leading edge of the sheet S is detected by the registration sensor 131, and the shift amount D with respect to the reference position in the Y direction is input to the controller 120. Is done.

  When the displacement in the Y direction due to the skew of the sheet by the angle θ is D1, and the displacement in the Y direction due to the lateral displacement of the sheet is D0, the shift amount D detected by the lateral registration sensor 35 is between The following relationship holds.

D = D0 + D1
D1 = L0 × tan θ
The controller 120 calculates an index for adjusting the position and angle of the side regulating plate of the manual sheet tray 300 based on the measured angle θ and shift amount D.

  First, with respect to the position of the side regulating plate 312, a correction amount to be corrected at the positions of the hands 315 and 316 is obtained in order to suppress the skew and lateral deviation of the sheet.

  As described with reference to FIG. 3, the pointers 315 and 316 of the side regulating plate 312 are located at a distance of L1 and L2 from the sheet leading edge position when the sheet S is set. The unit of each parameter is θ [rad], D [mm], L0 [mm], L1 [mm], L2 [mm], the position correction amount of the pointer 315 is Aa [mm], and the position correction amount of the pointer 316 Is Ab [mm].

  The controller 120 calculates the position correction amount of the pointer 315 as Aa [mm] and the position correction amount of the pointer 316 as Ab [mm] based on the following relationship (S4).

Aa = D + (L1-L0) × tan θ
Ab = D + (L2-L0) × tan θ
The controller 120 can also display the position correction amount Aa and the position correction amount Ab on the display panel 301 as numerical information in mm units. However, in this embodiment, for the convenience of the user's adjustment, the scale number based on the scale provided on the sheet tray described in FIG. As the position correction amount Aa and the position correction amount Ab, values that can correct the skew and lateral deviation of the sheet are displayed. For example, when the sheet is conveyed as shown in S2 of FIG. 6, a value that moves the side regulating plate 312 so that the image position on the photosensitive drum 112 and the sheet position are in the ST state. Is displayed.

  For example, in the case where the scale 317 and the scale 318 are scaled at intervals of Sc [mm] per scale, when the numbers of scales to be corrected by the user for the pointers 315 and 316 are Ma and Mb, respectively, (S5).

Ma = Aa ÷ Sc
Mb = Ab ÷ Sc
The controller 120 displays the calculated Ma and Mb on the display panel 301 as information associated with the scale, mark, and mark of the sheet tray. For example, when the calculated Ma and Mb are less than 1 (S6), “adjustment is not required” is displayed (S7). When the calculated Ma and Mb are 1 or more, the number of scales to be corrected in association with the mark and mark is displayed ( S8). By this display, the user can obtain the necessity of adjusting the position and angle of the side regulating plate of the sheet tray 300 and the operation procedure information when necessary.

  For example, the controller 120 displays the calculated Ma and Mb on the display panel 301 as information associated with the scale, mark, and mark of the sheet tray.

  Hereinafter, a user operation when the operation procedure information is displayed on the display surface 71 of the display panel 301 will be described.

  For example, the user who has confirmed the information displayed as shown in FIG. 7 can recognize that the position adjustment of the side restriction plate 311 and the side restriction plate 312 of the sheet tray 300 is necessary. Then, the positions of the side regulating plate 312 and the side regulating plate 311 are adjusted according to the displayed procedures (1) to (4). At this time, the number of scales to be corrected in association with the indicator 321 and the mark 319 provided on the sheet tray 300, such as “A pointer is 3 scales in the + direction” and “B needle is 1 scale in the − direction”. Is displayed. For this reason, the user can adjust the position and angle of the side regulating plate 312 very easily. Then, a rectangular sheet is brought into contact with the side regulating plate 312, and the position of the side regulating plate 311 is adjusted so that the sheet is sandwiched between the side regulating plate 312 and the side regulating plate 311. That is, the position of the side regulating plate 311 is adjusted so that there is no gap between the sheet and the side regulating plate 312 (and the side regulating plate 311) when the sheet is set. When the position adjustment of the side regulating plate 311 and the side regulating plate 312 is completed, the user presses the completion button of the input unit 302.

  When it is determined that the user has pressed the completion button (S9), the controller 120 determines that the adjustment by the user is completed and ends the test mode (S10).

  As described above, by executing the test mode, the user confirms whether or not it is necessary to adjust the position and angle of the side regulation plate of the manual sheet tray 300 before printing on a long sheet. can do. When it is necessary to adjust, the number of scales to be corrected is displayed in association with the signs and marks, so that the position and angle of the side regulating plate can be adjusted very easily. By displaying such an adjustment method, even a long sheet can be prevented from being laterally shifted and skewed, and high-quality printing is possible.

  Further, it is possible to print and output information necessary for adjusting the position of the side regulating plate on the sheet fed in the test mode.

  FIG. 9 shows an example in which information is printed on the sheet S for the convenience of the user. The operation procedure information 91 similar to that displayed on the display panel 301 is printed at an easily viewable position on the sheet S.

  Further, when the sheet is set on the sheet tray 300 in FIG. 3, the scale is placed at a position corresponding to the pointer 315 and the pointer 316, that is, a position on the sheet corresponding to the signs A and B on the side regulating plate 312. You may print. For example, a scale having the same scale as the scale 317 and the scale 318 of the base 320 of the sheet tray may be printed on the sheet, like the scale 92 and the scale 93 in FIG. In the test mode, the sheet S is fed to the image forming unit without correction of skew and lateral deviation. Therefore, the printed scale 92 and scale 93 allow the user to determine the amount of skew and lateral deviation on the sheet tray. The scale 317 and the scale 318 can be visually recognized on the same scale.

  On the other hand, it is possible to discharge the sheet fed in the test mode without printing anything. The user can reuse the sheet used in the test mode for printing.

(Registration mode)
Next, the operation of the registration unit 1 in the registration mode, which is a feeding mode when printing on a sheet, will be described.

  FIG. 10 is a flowchart showing an operation sequence in the registration mode. When copying or printing is started, the pickup roller 101 is driven. The sheets stacked on the manual sheet tray 300 are separated one by one by the feed roller 102 and the retard roller 103 driven by the manual sheet drive motor 304, and conveyed to the registration unit 1 (S20).

  A part of the peripheral surface of the driving roller of the registration roller pair 21 and 22 and the registration roller pair 30 is cut off, and the position where this part faces the driven roller is the home position of the driving roller of each roller pair. It has become. At the home position, each roller pair is in a state where the driving roller and the driven roller are separated from each other. Therefore, when the driving roller is at the home position, the roller pair does not pinch the sheet. Each roller pair is controlled so that the driving roller is positioned at the home position before the start of sheet conveyance (when the roller is stopped).

  When the leading edge of the sheet conveyed to the registration unit is detected by the activation sensors 27a and 27b, the skew correction motors 23 and 24 are started based on the respective sensors, and the skew correction roller pair 21 and 22 rotate to rotate the sheet. Is transported. From the detection time difference between the activation sensors 27a and 27b, the skew amount of the sheet in the S1 state is calculated, and the first skew correction is performed (S21). If the skew correction cannot be corrected by only the first skew correction, the skew detection amount of the sheet is detected by the downstream skew detection sensor 28, and the second skew correction is performed (S22). The first skew correction is based on the detection time difference between the start sensors 27a and 27b to determine the leading side of the leading edge of the sheet, and the rotational speed of the skew correction driving roller on the leading side is determined as follows. This is done by making it slower than the rotational speed of the skew correction drive roller on the non-preceding side. The skew correction may be performed by making the rotation speed of the skew correction driving roller on the non-preceding side faster than the rotation speed of the skew correction driving roller on the preceding side. Similarly to the first skew correction, the second skew correction also corrects the skew of the sheet by changing the speed of the skew correction drive roller.

  Further, the registration motor 31 is started based on the delay side of the skew detection sensor 28a and the skew detection sensor 28b, the registration roller pair 30 rotates, and the sheet is conveyed by the registration roller pair 30 (S23). When the sheet is nipped by the registration roller pair 30, the skew correction motors 23 and 24 are set so that the skew correction drive rollers 21a and 22a are at the home position based on detection of the skew correction HP sensors 25 and 26. Stop (S24).

  When the leading edge of the sheet is detected by the registration sensor 131 (S25), at the same time, the lateral edge position of the sheet is detected by the lateral registration sensor 35 (S26). Based on the time difference between the detection timing of the registration sensor 131 and the timing at which the photosensitive drum 112 is irradiated with laser light, and based on the detection signal of the lateral registration sensor 35 and the determined lateral registration target position, The shift motor 33 is controlled. Then, the front end position and the lateral registration position are controlled so that the ST state where the image position on the photosensitive drum 112 and the sheet position coincide with each other (S27, S28, S29).

  The sheet conveyed by the registration roller pair 30 is transferred and attracted to the photosensitive drum 112, and after the conveyance by the roller downstream of the registration roller pair 30 in the sheet conveyance direction is started, the registration motor 31 stops. Based on the detection of the registration HP sensor 26, the registration motor 31 stops so that the registration driving roller 30a is at the home position (S30).

  The registration shift motor 33 is activated, and the registration driving roller pair 30 is shifted in a direction opposite to the direction in which the registration roller pair 30 is moved in (S29). The registration shift motor 33 is stopped based on the detection of the registration shift HP sensor 34 that detects the home position of the registration roller pair 30 in the shift direction, and the registration roller pair 30 stops at the home position in the Y direction (S31). The sheet on which the position of the image on the photosensitive drum 112 and the toner image has been transferred with high accuracy is transferred to the fixing device 118 and then discharged outside the apparatus (S32).

  By the above operation, the sheet can be fed to the image forming unit while detecting and correcting the skew and lateral registration shift of the sheet in the registration unit 1.

[Second Embodiment]
The image forming apparatus according to the second embodiment has the apparatus configuration described with reference to FIGS. 1 and 2 as in the first embodiment, whereas the first embodiment includes the manual sheet tray illustrated in FIG. The second embodiment is different in that it includes the manual sheet tray shown in FIG.

(Sheet tray)
FIG. 11 is a plan view showing a schematic configuration of the manual sheet tray 300 according to the second embodiment, but illustrations of mechanisms such as the pickup roller 101, the feed roller 102, the retard roller 103, and the like are omitted. Reference numeral 320 in the figure denotes a base of the manual sheet tray 300.

  The angle adjusting plate 330 is a member for adjusting the angles of the side regulating plate 325 and the side regulating plate 328 as sheet position regulating members. The angle adjustment plate 330 is normally fixed to the base 320. However, when the angle is adjusted, the angle adjustment plate 330 can be rotated around a rotation fulcrum 340 at a distance L1 from the sheet front end position.

  The side regulating plate 325 and the side regulating plate 328 are respectively fixed to the angle adjusting plate 330 by an adjusting knob 326 and an adjusting knob 329 that are position adjusting portions. If the user loosens the adjustment knob, the position of the side regulating plate can be adjusted along the longitudinal direction of the angle adjusting plate 330 (that is, the rotational radial direction).

  The side regulating plate 325 is provided with a pointer 327 as an index, and the side regulating plate 328 is provided with a pointer 323 as an index. The pointer 327 and the pointer 323 are provided at a position separated from the sheet leading edge position when the sheet S is set by a distance L1 on the downstream side in the sheet conveyance direction.

  The base 320 is provided with a scale 324 as a position adjustment scale at a position corresponding to the pointer 323. The scale 324 is an angle scale for adjusting the angle of the sheet. The angle adjustment plate 330 is provided with a scale 322 as a position adjustment scale at a position corresponding to the pointer 327. The scale 324 is a scale indicating the distance in the direction orthogonal to the sheet conveying direction. This is for the convenience of the user adjusting the position and angle of the side regulating plate when the test mode is executed.

  Further, in order to make it easy for the user to distinguish between the pointer 327 and the pointer 323, indicators 332 C and D are displayed in the vicinity of each pointer. A mark 331 indicating the adjustment direction is displayed in the vicinity of the scale 322 and the scale 324 of the base 320.

  The pointer 327 and the scale 322 are used when adjusting the lateral displacement position, and the pointer 323 and the scale 324 are used when performing skew adjustment.

  Note that the pointers, scales, marks, and marks are not limited to the example shown in FIG. 11 as long as they are easily visible to the user.

  Next, the test mode according to the second embodiment will be described.

(Test mode)
The user executes a test mode in the printer 1000 to check whether or not the angle of the angle adjustment plate 330 of the manual sheet tray 300 and the position of the side regulation plate need to be adjusted before printing on the sheet. Can be made.

  Also in the second embodiment, the registration unit 1 is used to measure the angle θ at which the sheet S is skewed and the shift amount D that is laterally shifted. The controller 120 calculates an index for adjusting the position and angle of the side regulating plate of the manual sheet tray 300 based on the measured angle θ and shift amount D.

  First, the angle at which the angle adjustment plate 330 should be adjusted for skew adjustment is θ [rad], but this is converted into the number of scales Md based on the scale 324 of c [rad] per scale. The controller 120 performs the following calculation.

Md = θ ÷ c
The controller 120 performs the following calculation.

Ac = D + (L1-L0) × tan θ
Mc = Ac ÷ a
A position correction amount Ac [mm] for adjusting the side regulating plate 325 for lateral shift position adjustment is obtained, and Ac [mm] is further set to the scale number Mc of the scale 322 engraved at intervals of a [mm] per scale. This is a calculation for conversion.

  The controller 120 displays the calculated Mc and Md on the display panel 301 as information associated with the sheet tray scale 322, scale 324, indicator 332, and mark 331. For example, when the calculated Mc and Md are less than 1, “adjustment is unnecessary” is displayed, and when the calculated Mc and Md are 1 or more, the number of scales to be corrected in association with the mark and mark is displayed. By this display, the user can obtain the necessity of adjusting the angle of the angle adjustment plate 330 of the sheet tray 300 and the position of the side regulating plate, and the operation procedure information when necessary.

  For example, the operation procedure information “Adjust the D pointer by 4 scales in the (−) direction and adjust the C pointer by 2 scales in the (+) direction” is displayed on the display surface 71 of the display panel 301. The operation of the user will be described.

  A user who has confirmed the displayed information can recognize that the position adjustment of the angle adjustment plate 330, the side regulation plate 325, and the side regulation plate 328 of the sheet tray 300 is necessary.

  The user adjusts the angle by setting the angle adjustment plate 330 in a rotatable state. At this time, since the number of scales to be corrected is displayed in association with the mark 332 and the mark 331 provided on the sheet tray 300, such as “D pointer is 4 scales in the minus direction”, the user can very easily The angle of the angle adjusting plate 330 can be adjusted and fixed.

  Next, the adjustment knob 329 is loosened and the pointer C of the side regulation plate 325 is adjusted by two graduations in the (+) direction, and then the adjustment knob 326 is tightened to fix the side regulation plate 325 to the angle adjustment plate 330. Further, the adjustment knob 329 is loosened to adjust the position of the side regulation plate 328 so that no gap is generated when the seat is set, and then the adjustment knob 329 is tightened to fix the side regulation plate 328 to the angle adjustment plate 330. To do. When the above adjustment operation is completed, the user presses the completion button of the input unit 302.

  When the user presses the completion button, the controller 120 that has received notification of adjustment completion ends the test mode.

  Also in the second embodiment, it is possible to print and output information necessary for adjusting the position of the side regulating plate on the sheet fed in the test mode, as in the first embodiment.

  As described in the first embodiment with reference to FIG. 9, the information displayed on the display panel 301 may be printed, or the scale 92 and the scale 93 may be printed. The user can visually check the amount of deviation from the reference position of the printed scale 92 and the scale 93, and can easily calculate the number Md of skew adjustment scales from the amounts of deviation Ma and Mb. . The scale number Md is calculated by the following formula.

    Md = Mb-Ma

[Third embodiment]
The image forming apparatus of the third embodiment has the apparatus configuration described with reference to FIGS. 1 and 2 as in the first embodiment, but the first embodiment includes the manual sheet tray 300 of FIG. On the other hand, the third embodiment is different in that the cassette type sheet tray 100 of FIG. 12 is provided.

  The cassette type sheet tray 100 of FIG. 12 which is a sheet supporting portion has a sheet position restricting member, and includes a fixing hook 150 and a fixing hook 151 which are rotatably fixed at positions L1 and L2 from the sheet leading end position. Prepare. The fixing hook 150 and the fixing hook 151 correspond to a pin 156 and a pin 157 that are cassette type sheet tray fixing pins on the printer main body side. The fixed hook 150 and the fixed hook 151 are provided with a fixed adjustment knob 154 and a fixed adjustment knob 155 as position adjusting portions, and further, an adjustment scale 152 and an adjustment scale 153 are provided as position adjustment scales in the vicinity thereof.

  Also in the third embodiment, when the test mode is executed as in the first embodiment, information related to the position adjustment of the fixed hook 150 and the fixed hook 151 is displayed on the display panel 301. Further, as in the first embodiment, it is also possible to print and output information necessary for position adjustment on a sheet fed in the test mode. As described in the first embodiment with reference to FIG. 9, information displayed on the display panel 301 may be printed, and a scale 92 and a scale 93 may be printed. However, as is apparent from the apparatus configuration of FIG. 1, the sheets set on the cassette type sheet tray 100 of the third embodiment are fed in the opposite direction to the sheets set on the manual type sheet tray 300 for printing. Is performed on the back of the sheet.

[Other Embodiments]
In the above embodiment, the printer main body 1001 and the scanner 2000 are separate, but the printer main body 1001 and the scanner 2000 may be integrated.

  In addition to inputting the scanner 2000 signal to the printer main body 1001 and functioning as a copying machine, the printer main body 1001 can also function as a FAX by inputting a FAX signal, or can function as a printer by inputting a PC signal. Good.

  Further, in the above-described embodiment, the display indicating that the adjustment is necessary is performed when the correction amount detected in the test mode is one graduation or more.

  For example, the maximum skew and lateral shift that can be corrected in the registration mode may be stored in advance, the measured shift amount may be compared with this, and the information to be displayed may be changed based on the comparison result.

  That is, the controller stores in advance, in the memory, θmax, which is the maximum value of θ that can be corrected by the registration unit 1 when the sheet is conveyed in the registration mode, and Dmax, which is the maximum value of D that can be corrected. The controller compares θ and D measured in the test mode with θmax and Dmax, respectively, and when the former exceeds the latter, displays the adjustment procedure together with a message indicating that adjustment is necessary. Conversely, if the former does not exceed the latter, a message that adjustment is not necessary is displayed. As a result, it is possible to efficiently suppress the deterioration of the print image quality caused by the skew or lateral shift of the sheet.

  Information necessary for the adjustment may be displayed not only on the display panel but also in a voice message.

  In the first embodiment and the second embodiment, an example of a manual feed type sheet tray has been described. However, a similar mechanism can be applied to a cassette type sheet tray.

  In the above-described embodiment, the sheet skew amount θ is measured using the skew detection sensor 28a and the skew detection sensor 28b of FIG. 4, but is not limited thereto. For example, if the lateral registration sensor 35 measures two lateral registration amounts along the longitudinal direction of the sheet while feeding the sheet, the skew feeding amount θ can be obtained by calculation.

  In the above-described embodiment, in the registration mode, active registration is performed in which the skew feeding correction motor and the registration shift motor are driven to correct the skew feeding and the positional deviation. However, the present invention is not limited to this. For example, a method of correcting skew by abutting a sheet against an abutting member may be used.

  In the above embodiment, an electrophotographic apparatus is used as the image forming unit. However, the present invention is not limited to this. For example, an ink jet system, a thermal transfer system, or a sublimation printer may be used.

  1000 ... Printer / 3000 ... Operation unit / 301 ... Display panel / 120 ... Controller / 1 ... Registration unit / 300 ... Manual sheet tray / 315,316 ... Pointer / 317, 318 ... Scale / 319 ... Mark / 321 ... Mark / S ... Sheet / 28a, 28b ... Skew detection sensor / 35 ... Horizontal registration sensor / 71 ... Display surface /323,327...Guidelines/322,324...Scale/331...Mark/332...Sign/

Claims (16)

A sheet support part for supporting the sheet;
An image forming unit for forming an image on a sheet;
A sheet conveying unit that conveys a sheet from the sheet supporting unit to the image forming unit;
An information display section for displaying information;
A control unit for controlling the display of the information display unit,
The sheet support part includes a sheet position restriction member that restricts the position of the sheet supported by the sheet support part, a position adjustment part that adjusts the position of the sheet position restriction member, and an index that indicates the position of the sheet position restriction member; A position adjustment scale provided corresponding to the index,
The position adjusting unit is capable of adjusting the sheet position regulating unit with respect to a direction orthogonal to the sheet conveying direction and an angle with respect to the sheet conveying direction.
The sheet conveying unit includes a detecting unit that detects skew and lateral deviation of a sheet conveyed during conveyance from the sheet support unit to the image forming unit,
The control unit causes the information display unit to display the number of scales of the position adjustment scale for adjusting the position of the sheet position regulating member based on detection by the detection unit.
An image forming apparatus. The detection unit detects skew and lateral deviation of the sheet, and the control unit calculates a correction amount for correcting skew and lateral deviation based on the detection result of the detection unit, and adjusts the correction amount to the position adjustment. Convert to the number of tick marks,
The image forming apparatus according to claim 1. The sheet support part is a manual sheet tray.
The image forming apparatus according to claim 1, wherein: The sheet support portion is a cassette type sheet tray.
The image forming apparatus according to claim 1, wherein: The position adjustment scale is an adjustment scale indicating a position in a direction orthogonal to the sheet conveyance direction, and is a scale provided at a plurality of locations along the sheet conveyance direction.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The position adjustment scale is an adjustment scale indicating the position in the direction perpendicular to the sheet conveyance direction and the adjustment scale of the angle in the sheet conveyance direction.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The indicator is an indicator provided in plural along the sheet conveying direction.
The image forming apparatus according to claim 5. The indicator is an indicator provided in plural along a direction orthogonal to the sheet conveying direction.
The image forming apparatus according to claim 6. The sheet support portion has a mark attached to the indicator and a mark attached to the position adjustment scale.
The image forming apparatus according to claim 2. The control unit causes the information display unit to display the result of converting the correction amount into the number of scales of the position adjustment scale as information associated with the mark and the mark,
The image forming apparatus according to claim 9. The control unit prints the result of converting the correction amount into the number of scales of the position adjustment scale on the sheet by driving the image forming unit.
The image forming apparatus according to claim 2. The control unit drives the image forming unit to print the sheet on the sheet by using the result of converting the correction amount to the number of scales of the position adjustment scale as information associated with the mark and the mark.
The image forming apparatus according to claim 9. The control unit prints a scale of the same scale as the position adjustment scale on the sheet by driving the image forming unit.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The control unit performs a registration mode in which the sheet is conveyed to the sheet conveying unit while correcting skew and lateral deviation of the sheet, and a test for detecting the amount of skew and lateral deviation by conveying the sheet without correcting skew and lateral deviation. Mode, and
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The control unit stores a maximum value of skew and lateral deviation that can be corrected in the registration mode, compares the detected value in the test mode with the maximum value, and displays the information based on the comparison result Change the information displayed in the
The image forming apparatus according to claim 14. The image forming unit is one of an electrophotographic method, an inkjet method, a thermal transfer method, and a sublimation printer.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

Images