JP2013098695A - Image forming apparatus and position detection method of document feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of reducing burdens on an operator by shortening adjustment time required when the operator attaches a document feeder to an image forming apparatus body.SOLUTION: A copying machine includes an image sensor unit 83 capable of reading a luminance distribution in a main scanning direction, a document feed part 9 having a first platen roller 97b and capable of feeding a document D, and a hinge part 70 capable of adjusting a position of the document feed part 9 to the image sensor unit 83. The copying machine is provided with: a scanner controller 10 provided with a mark part 101 having luminance different from that of the first platen roller 97b on two or more positions in an axial direction on a surface of the first platen roller 97b, for acquiring luminance distribution information on a main scanning line by reading the surface of the platen roller and the mark parts 101 by the image sensor unit 83 and calculating position deviation information of the document feed part 9 with respect to the image sensor unit 83 from the acquired luminance distribution information; and a display part 17 for displaying the calculated position deviation information.

Description

  The present invention relates to an image forming apparatus capable of reading an image of a document, and more particularly to an image forming apparatus having a document feeding device capable of feeding a document to a predetermined image reading unit.

  2. Description of the Related Art Conventionally, some image forming apparatuses such as digital copying machines have a so-called flow-readable image reading apparatus that reads image information of a document passing over a platen glass with an optical system disposed below the platen glass. Are known. Such an image reading device has a document feeding device that automatically feeds a document on the platen glass, and the document feeding device can read an image even if the document is placed directly on the platen glass. The image forming apparatus main body is attached to the image forming apparatus main body so as to be rotatable.

  Incidentally, the conventional image forming apparatus is not provided with an automatic adjustment function capable of automatically adjusting the attachment position of the document feeder relative to the image forming apparatus main body. For this reason, for example, when the document feeder is newly attached to the image forming apparatus main body at the time of shipment, the attachment position of the document feeder relative to the image forming apparatus main body must be adjusted.

  Here, the adjustment of the attachment position of the document feeder with respect to the conventional image forming apparatus main body is performed by feeding the document with the document feeder, and the operator confirms the skewed state of the fed document one by one. It was done while. This work, which is repeatedly performed while checking the document, varies greatly in work time depending on the experience of the worker, etc., and a worker with little experience needs a lot of time and labor. For this reason, the adjustment operation of the document feeder is very complicated for an operator having little experience.

  For this, a plurality of brightness levels of the document fed by the document feeding device are measured in the main scanning direction, and the position of the document feeding device is determined from the positional deviation in the sub scanning direction of the plurality of brightness levels indicating the maximum value. A technique capable of detecting a shift has been proposed (see Patent Document 1).

JP 2004-129140 A

  However, the image forming apparatus described in Patent Document 1 can reduce the work time related to the adjustment in the planar direction by detecting the positional deviation in the sub-scanning direction of a plurality of luminance levels indicating the maximum value. The floating of the sent document in the image reading unit cannot be detected. For this reason, for the floating of the original in the image reading unit, a separate work for detecting the floating amount is required by an operator, which suppresses the reduction of the work time for adjustment.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of reducing the adjustment time required when attaching the document feeder to the image forming apparatus main body and reducing the burden on the operator.

  The present invention includes an image reading unit capable of reading a luminance distribution on a scanning line, and a platen roller disposed opposite to the scanning line of the image reading unit, and capable of feeding the original to the image reading unit. In an image forming apparatus comprising: a feeding device; and a position adjusting mechanism capable of adjusting a position of the document feeding device with respect to the image reading unit. On the surface of the platen roller, a brightness different from that of the surface of the platen roller. Are provided in two or more locations in the axial direction, the surface of the platen roller and the mark are read in the scanning line direction by the image reading means to acquire luminance distribution information on the scanning line, and the acquired scanning line direction A control unit that calculates positional deviation information of the document feeder with respect to the image reading unit from luminance distribution information of the image, and a display unit that displays positional deviation information calculated by the control unit , With a, characterized in that.

  According to the present invention, marks are provided at two or more positions in the axial direction of a platen roller that feeds a document to a document reading position, and positional deviation information at an image reading unit is calculated from the mark, whereby the document feeding device is Adjustment time required for attaching to the image forming apparatus main body can be shortened to reduce the burden on the operator.

1 is a cross-sectional view schematically showing the overall structure of a copier according to a first embodiment of the present invention. FIG. 2 is a perspective view schematically showing the overall structure of the image reading unit according to the first embodiment. It is sectional drawing of the image reading part shown in FIG. It is a perspective view which shows typically the internal structure of the reader part which concerns on 1st Embodiment. It is a top view which shows the 1st platen roller which concerns on 1st Embodiment. 1 is a block diagram showing a scanner controller of a copying machine according to a first embodiment. (A) is a figure which shows the state in which the original document feeding part is normally attached to the reader part, (b) is a figure which shows the state in which the original document feeding part is inclined and attached to the right. . (C) is a diagram illustrating a state where the left side of the document feeding unit is floating, and (d) is a diagram illustrating a state where the document feeding unit is attached to be inclined to the right and the left side is floating. FIG. (A) is a figure which shows the state in which the original document feeding part is normally attached to the reader part, (b) is a figure which shows the state in which the original document feeding part is inclined and attached to the right. (C) is a figure which shows the state in which the original feeding part is attached inclining to the left. 3 is a flowchart illustrating an operation of the scanner controller according to the first embodiment. It is a top view which shows the 1st platen roller which concerns on 2nd Embodiment. (A) is a figure which shows the state in which the original document feeding part is normally attached to the reader part, (b) is a figure which shows the state in which the original document feeding part is inclined and attached to the right. (C) is a figure which shows the state in which the original feeding part is attached inclining to the left.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. An image forming apparatus according to an embodiment of the present invention is an image forming apparatus including a document feeding device capable of automatically feeding a document to an image reading position. In the following embodiments, a black and white / color copying machine (hereinafter referred to as “copying machine”) will be described as an image forming apparatus.

<First Embodiment>
A copying machine 1 according to a first embodiment of the present invention will be described with reference to FIGS. First, a schematic configuration of the copying machine 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view schematically showing the overall configuration of the copying machine 1 according to the first embodiment of the present invention. In the following, the position where the user faces an operation unit (not shown) where various inputs / settings are performed on the copying machine 1 is referred to as “front side” of the copying machine 1 and the back side is referred to as “back side”. That is, FIG. 1 shows the internal configuration of the copying machine 1 viewed from the front side, and a display unit 17 described later is provided on the front side of the copying machine 1.

  As shown in FIG. 1, the copying machine 1 transfers a sheet feeding unit 2 that feeds a sheet S, an image forming unit 3 that forms an image, and an image formed by the image forming unit 3 to the sheet S. The transfer unit 4, the fixing unit 5 that fixes the image transferred by the transfer unit 4 to the sheet S, the discharge unit 6 that discharges the sheet S on which the image is fixed, and the image reading unit 7 that reads the image information of the document D And.

  The sheet feeding unit 2 is disposed in the lower part of the copying machine 1, and includes a storage cassette 21 that stores the sheet S, a feeding roller 22 that feeds the sheet S stored in the storage cassette 21, and a feeding And a separation unit 23 that separates the sheets S fed by the rollers 22 one by one.

  The image forming unit 3 is disposed above the sheet feeding unit 2 and forms a toner image of four colors of yellow (Y), magenta (M), cyan (C), and black (K). The drums 31Y to 31K, the primary chargers 32Y to 32K that apply and uniformly charge the surfaces of the photosensitive drums 31Y to 31K, and the photosensitive drums 31Y to 31K are statically irradiated with laser light based on image information. Exposure devices 33Y to 33K that form electrostatic latent images and developing devices 34Y to 34K that visualize electrostatic latent images formed on the photosensitive drums 31Y to 31K as toner images are provided.

  The transfer unit 4 is disposed below the photosensitive drums 31Y to 31K, and is a transfer belt 41 that is rotationally driven, and transfer units 42Y to 42K that transfer the color toner images of the photosensitive drums 31Y to 31K to the transfer belt 41. And. The fixing unit 5 is disposed on the downstream side of the transfer unit 4, and includes a fixing roller 51 with a built-in heater and a pressure roller 52 that presses against the fixing roller 51. The discharge unit 6 is disposed on the downstream side of the fixing unit 5 and includes a discharge roller pair 61 that discharges the sheet S to the outside of the apparatus, and a discharge tray 62 that stacks the sheet S discharged to the outside of the apparatus. ing.

  The image reading unit 7 is disposed on the upper part of the copying machine 1 and includes a reader unit 8 that reads an image of the document D and a document feeding unit 9 that can feed the document D to the reader unit 8. Yes. The image reading unit 7 will be described in detail later.

  Next, an image forming job of the copying machine 1 according to the first embodiment configured as described above will be described. When the image forming job of the copying machine 1 is started, the exposure devices 33Y to 33K irradiate the surfaces of the photosensitive drums 31Y to 31K with laser light based on image information from a personal computer (not shown) or the image reading unit 7. As a result, the surfaces of the photosensitive drums 31Y to 31K that are uniformly charged to a predetermined polarity potential by the primary chargers 32Y to 32K are sequentially exposed, and electrostatic latent images are formed on the surfaces of the photosensitive drums 31Y to 31K. Is done. When the electrostatic latent images are formed on the surfaces of the photosensitive drums 31Y to 31K, the developing devices 34Y to 34K develop the electrostatic latent images and visualize them as toner images.

  In parallel with the toner image forming operation, the sheets S stored in the storage cassette 21 are fed out by the feeding roller 22 and separated one by one by the separation unit 23. The separated sheet S reaches a registration roller (not shown), and is conveyed to the transfer units 42Y to 42K by the registration roller at a predetermined timing. When the sheet S is conveyed to the transfer units 42Y to 42K, the visualized toner images of the respective colors are sequentially superimposed and transferred onto the sheet S by the transfer bias applied to the transfer units 42Y to 42K. As a result, a full-color (four-color) toner image is formed on the sheet S.

  The sheet S on which the full-color toner image is transferred is conveyed from the transfer unit 4 to the fixing unit 5, and is fixed as an image by receiving heat and pressure in the fixing unit 5 and melting and mixing the toner. Thereafter, the sheet S on which the image is fixed is discharged to a discharge tray 62 by a discharge roller pair 61 provided downstream of the fixing unit 5, and the image forming job is completed.

  When forming images on both sides of the sheet S, the fixing roller 5 fixes the unfixed toner image on the sheet S and then discharges the discharge roller pair 61 before discharging it to the discharge tray 62 by the discharge roller pair 61. The sheet S is conveyed to the double-sided conveyance path 63 by rotating in the reverse direction. The sheet S is reversed by being conveyed to the duplex conveying path 63, and the inverted sheet S is conveyed again to the image forming unit 3 by the conveying roller provided in the duplex conveying path 63, and the above is repeated.

  Next, the image reading unit 7 according to the first embodiment will be described with reference to FIGS. FIG. 2 is a perspective view schematically showing the overall structure of the image reading unit 7 according to the first embodiment. FIG. 3 is a cross-sectional view of the image reading unit 7 shown in FIG. FIG. 4 is a perspective view schematically showing the internal structure of the reader unit 8 according to the first embodiment. FIG. 5 is a plan view showing the first platen roller 97b according to the first embodiment.

  As shown in FIG. 2, the image reading unit 7 includes a reader unit 8 that reads an image of the document D, and a document feeding unit 9 that can feed the document D to the reader unit 8. The document feeding unit 9 is rotatably supported by the reader unit 8 by hinge units 70 and 70 serving as a position adjusting mechanism disposed on the back side so that the document reading position 100 of the reader unit 8 can be opened and closed. ing. The hinges 70, 70 include a position adjusting unit (not shown) that can adjust the position of the document feeding unit 9 with respect to the reader unit 8, and the position of the document feeding unit 9 with respect to the reader unit 8 by an operator or the like. Is configured to be adjustable.

  As shown in FIGS. 3 and 4, the reader unit 8 includes a platen glass 80 disposed so as to be positioned below a document feeding device 90 to be described later, and a platen glass 80 and a subsidiary plate sandwiching a support stay 81. A document table glass 82 arranged side by side in the scanning direction, a platen glass 80 and a casing 8a for holding the document table glass 82, and an image sensor unit 83 as image reading means are provided.

  The document table glass 82 is used for placing the document D. The document table glass 82 serves as a reference for the main scanning direction as the scanning line direction when placing the document D on the document table glass 82. 82a and an image reference plate 82b serving as a guide in the sub-scanning direction are pasted. Under the original table glass 82, sub-scanning size sensors 82c and 82d for detecting the sub-scanning width of the original D are attached. The housing 8a rotatably supports the document feeding unit 9 so that the platen glass 80 and the document table glass 82 can be freely opened, and accommodates the image sensor unit 83 therein.

  The image sensor unit 83 includes an LED 84 that irradiates light on the document D, a plurality of mirrors 85a, 85b, and 85c that guide reflected light from the document D corresponding to the light irradiated on the LED 84, and a plurality of mirrors 85a to 85c. A condensing lens 86 that condenses the reflected light guided by the light source, and a CCD 87 that photoelectrically converts the reflected light collected by the condensing lens 86 and outputs it as an image signal. The LED 84 and the mirror 85 a are accommodated in an optical carriage (running body) 88, and the optical carriage 88 is connected to a drive belt 89. The drive belt 89 is connected to the drive motor 89a and is configured to be driven by the drive motor 89a. The drive motor 89a is composed of, for example, a stepping motor. The position of the optical carriage 88 can be grasped by a position sensor 16 described later and the number of rotation pulses of the drive motor 89a.

  The image sensor unit 83 irradiates light toward the document D with the LED 84, and the CCD 87 receives the reflected light reflected from the document D so that an image is projected. From the projected image, an image signal for each line is output. Generated. In the image sensor unit 83, the driving belt 89 is driven by the driving motor 89a, and the optical carriage 88 moves in the arrow direction (sub-scanning direction) shown in FIG. D can be optically scanned (placed document reading mode). Further, the image sensor unit 83 stops the optical carriage 88 at a predetermined document reading position 100 located below the document feeding unit 9 and feeds the document D by the document feeding unit 9, whereby the image of the document D is recorded. Information can be read (original scanning mode).

  Further, the image sensor unit 83 stops the optical carriage 88 at the document reading position 100 and reads a later-described first platen roller 97b in the main scanning direction, thereby obtaining luminance distribution information on the main scanning line of the first platen roller 97b. Acquisition is possible (luminance distribution acquisition step described later). The luminance distribution acquisition step will be described in detail in the control operation by the scanner controller 10 described later.

  The document feeder 9 includes a document feeder 90 that automatically feeds the document D, and a document table cover 91 that presses the document D placed on the document table glass 82. As shown in FIG. 3, the document feeder 90 includes a document tray 92 on which the document D is stacked, a feed roller 93 that feeds the document D stacked on the document tray 92, and a feed to the feed roller 93. A separation conveyance roller 94 and a separation pad 95 for separating the document D to be printed one by one, a registration roller pair 96 for conveying the document D with the front end aligned, and a document reading position 100 provided downstream of the registration roller pair 96. A document guide 97 that guides the document D and a discharge roller pair 98 that discharges the document D that has been read out of the apparatus.

  The document tray 92 includes a pair of width direction restricting plates 92 a provided so as to be slidable in the width direction of the document D. The pair of width direction restricting plates 92 a has a width direction of the document D loaded on the document tray 92. By regulating, the conveyance stability at the time of feeding the document D is ensured. The feeding roller 93 is provided above the document tray 92 and has a solid line position shown in FIG. 3 as a home position so as not to hinder the setting operation of the document D by the operator. When the feeding operation of the document D is started, the feeding roller 93 moves from the home position to a feeding position (a broken line position shown in FIG. 3), and abuts on the upper surface of the document D to feed the document D. . The registration roller pair 96 is provided downstream of the separation / conveyance roller 94, and the leading edge of the document D separated and conveyed one by one by the separation / conveyance roller 94 abuts on the nip portion, thereby causing a loop in the document D. By doing so, the leading edges of the document D are aligned. Thereafter, the registration roller pair 96 rotates and conveys the document D toward the document guide unit 97.

  The document guide unit 97 is provided so as to be positioned on the platen glass 80, and guides the document D whose front ends are aligned by the registration roller pair 96 so as to move on the platen glass 80. The document guide unit 97 includes a lead roller pair 97a, a first platen roller 97b as a platen roller, a reading guide (not shown) having a white plate, a second platen roller 97c, and a lead discharge roller pair 97d. ing.

  The read roller pair 97 a transports the document D transported by the registration roller pair 96 onto the platen glass 80. The first platen roller 97b is provided downstream of the read roller pair 97a, and is disposed so as to face the scanning line of the optical carriage 88 (image sensor unit 83) stopped at the document reading position 100. Further, as shown in FIG. 5, on the surface of the first platen roller 97b, when reading the image of the document D, both ends that do not affect the reading of the image (the first platen more than the reading region of the document D). A mark portion 101 as a mark and two or more intersection portions 102 orthogonal to the mark portion 101 are provided outside the roller 97b in the axial direction (hereinafter referred to as “invalid area”). The mark portion 101 has a luminance different from that of the surface of the first platen roller 97b, and is drawn in a rectangular shape having a predetermined width parallel to the sub-scanning direction.

  The mark portion 101 and the intersection portion 102 are attached to the first platen roller 97b with a sticker drawn in a rectangular shape at the time of adjustment of the document feeding portion 9 performed at the time of shipment or the like. It may be configured to be possible. For example, the mark portion 101 and the intersection portion 102 may be configured by a seal member, and in this case, since it can be peeled later, it is not necessary to stick to the invalid area. Further, the mark portion 101 and the intersection portion 102 may be provided on the second platen roller 97c, for example.

  The reading guide is provided downstream of the first platen roller 97b, and the original D conveyed to the original reading position 100 by the first platen roller 97b is in close contact with the platen glass 80 along the platen glass 80. invite. The second platen roller 97c is provided downstream of the reading guide, and conveys the document D that has been guided by the reading guide and has finished reading image information. The lead discharge roller pair 97d is provided on the downstream side of the second platen roller 97c, and conveys the document D conveyed by the second platen roller 97c to the discharge roller pair 98.

  The discharge roller pair 98 is provided downstream of the document guide portion 97 and discharges the document D to the outside of the apparatus. Further, when reading both sides of the document D, the discharge roller pair 98 switches back the document D and conveys it again to the registration roller pair 96 via the sheet path 99.

  The document table cover 91 is supported by the casing 8a so that the platen glass 80 and the document table glass 82 can be freely opened and closed, and presses the document D so that the document D placed on the document table glass 82 does not move by the closing operation. It is made possible. The document table cover 91 is provided with an open / close sensor 91a capable of detecting the opening angle of the document table cover 91 with respect to the housing 8a. The open / close sensor 91a includes two sensors (not shown) and one flag (not shown). 4), the opening / closing angles of the four patterns of the document table cover 91 can be detected.

  Next, from the luminance distribution information in the main scanning direction of the first platen roller 97b, the amount of inclination of the document feeding unit 9 with respect to the reader unit 8 and the amount of floating of the first platen roller 97b with respect to the platen glass 80 as positional deviation information are obtained. A scanner controller 10 as a control unit capable of detection (position detection) will be described with reference to FIG. FIG. 6 is a block diagram showing the scanner controller 10 of the copying machine 1 according to the first embodiment.

  As shown in FIG. 6, the scanner controller 10 includes an inclination amount calculation unit 11 that calculates an inclination amount of the document feeding unit 9 with respect to the reader unit 8, and a float that calculates a floating amount of the first platen roller 97 b with respect to the platen glass 80. A quantity calculation unit 12. The scanner controller 10 also includes an A / D conversion circuit 13 that performs A / D conversion on the output signal of the CCD 87, a drive motor 89 a that scans the document D by moving the optical carriage 88 in the sub-scanning direction, and an LED 84 of the image sensor unit 83. LED driving circuit 14 for driving the first platen roller 97b provided with the mark portion 101, the backup RAM 15 for storing the calculated tilt amount and the floating amount, the position sensor 16 for detecting the position of the optical carriage 88, the tilt amount, It is electrically connected to a display unit 17 or the like that displays a floating amount or the like.

  The scanner controller 10 grasps the position of the optical carriage 88 based on the output signal from the position sensor 16 and the number of rotation pulses to the drive motor 89a. Further, the scanner controller 10 acquires luminance distribution information in the main scanning direction of the first platen roller 97b based on the output signal of the CCD 87 digitized by the A / D conversion circuit 13.

  Here, FIG. 7A to FIG. 8C illustrate luminance distribution information in the main scanning direction of the first platen roller 97b according to the first embodiment. FIG. 7A is a diagram illustrating a state where the document feeding unit 9 is normally attached to the reader unit 8. FIG. 7B is a diagram illustrating a state where the document feeding unit 9 is attached to be inclined to the right. FIG. 7C is a diagram showing a state where the left side of the document feeder 9 is floating. FIG. 7D is a diagram illustrating a state where the document feeding unit 9 is attached to be inclined to the right and the left side is floating. FIG. 8A is a diagram illustrating a state in which the document feeding unit 9 is normally attached to the reader unit 8. FIG. 8B is a diagram illustrating a state where the document feeding unit 9 is attached to be inclined to the right. FIG. 8C is a diagram illustrating a state where the document feeding unit 9 is attached to be inclined to the left.

  For example, as shown in FIGS. 7A and 8A, when the first platen roller 97b is in a normal state (a state in which there is no inclination with respect to the optical carriage 88), the mark portions 101 and 101 perform main scanning. It becomes a state orthogonal to the direction (parallel to the sub-scanning direction). Therefore, in the invalid area where the mark portions 101 and 101 are located, the reference brightness which is the same width as the reference width (mark width) in the main scanning direction and is a predetermined amount lower than the brightness value of the surface of the first platen roller 97b. Is obtained (see FIG. 7A). At this time, since the intersection 102 that is orthogonal to the mark portions 101 and 101 is detected simultaneously on the left and right, the luminance distribution information of the reference luminance that is lower by a predetermined amount is acquired at the same time on the left and right (see FIG. 8A).

  The reference width and the reference luminance are recorded in advance in a ROM (not shown) included in the scanner controller 10, and a control operation program and the like by the scanner controller 10 described later are also recorded in the ROM.

  Next, for example, as shown in FIGS. 7B and 8B, when the first platen roller 97b is inclined to the right, the mark portions 101 and 101 are inclined with respect to the main scanning direction. It becomes a state. Therefore, in the invalid area where the mark portions 101 and 101 are located, luminance distribution information is obtained that has a reference luminance that is wider than the reference width in the main scanning direction and lower than the luminance value of the surface of the first platen roller 97b by a predetermined amount. (See FIG. 7B). At this time, since the intersection 102 that is orthogonal to the mark 101 is detected with a delay on the right side, luminance distribution information with a reference luminance that is lower by a predetermined amount is acquired at a timing when the right side is delayed (see FIG. 8B). On the other hand, when it is inclined to the left side, the intersection part 102 orthogonal to the mark part 101 is detected with a delay on the left side, and therefore, luminance distribution information of a reference luminance that is lower by a predetermined amount is acquired at a timing with a delay on the left side. (See FIG. 8 (c)).

  Further, for example, as shown in FIG. 7C, in the state where the left side of the first platen roller 97b is floating, the mark portions 101, 101 are in a state orthogonal to the main scanning direction. Although the width is the same as the reference width, luminance distribution information is obtained in which the luminance of the invalid area where the left mark portion 101 is located is lower than the reference luminance. Further, for example, as shown in FIG. 7D, when the left side of the first platen roller 97b is floated and inclined to the right side, in the invalid area where the mark portions 101 and 101 are located, Luminance distribution information that is wider than the reference width and in which the luminance of the invalid area where the left mark unit 101 is located is lower than the reference luminance is obtained.

  The scanner controller 10 calculates the tilt amount and the float amount from the above-described luminance distribution information acquired based on the state of the first platen roller 97b, stores the calculated tilt amount and the float amount in the backup RAM 15, and It is displayed on the display unit 17. The calculation of the tilt amount and the floating amount by the scanner controller 10 and the display on the display unit 17 are normally performed when the document feeding unit 9 is attached to the reader unit 8 (when assembling or attaching options). You may comprise so that it may perform, before performing the scanning reading operation | movement by original document scanning mode, or when the power of the copying machine 1 is turned on. Moreover, you may comprise so that an operator may perform at arbitrary timings other than said timing.

  Next, FIG. 9 shows a control operation by the scanner controller 10 that calculates the inclination amount of the document feeding unit 9 with respect to the reader unit 8 and the floating amount of the first platen roller 97b with respect to the platen glass 80 from the acquired luminance distribution information. The description will be given with reference. FIG. 9 is a flowchart showing the operation of the scanner controller 10 according to the first embodiment.

  As shown in FIG. 9, first, the scanner controller 10 controls the drive motor 89a to move the optical carriage 88 in the direction of the platen glass 80 (sub-scanning direction) by a preset number of pulses from the home position position. Move. As a result, the optical carriage 88 moves below the document reading position 100 (step ST10).

  Next, the scanner controller 10 turns on the LED 84 attached to the optical carriage 88 and rotates the first platen roller 97b to mark the surface portion of the first platen roller 97b, the mark portions 101 and 101 and the intersection portion 102 of the invalid area. , 102 and the luminance distribution information in the main scanning direction of the first platen roller 97b is acquired (luminance distribution acquisition step). Specifically, the scanner controller 10 acquires luminance distribution information by reading the maximum luminance and mark width of the mark portions 101 and 101 (step ST15, step ST20, step ST35, and step ST40).

  Next, when the luminance distribution information in the main scanning direction is acquired, the tilt amount and the floating amount as the position shift information are calculated from the acquired luminance distribution information (position shift information calculation step). Specifically, the scanner controller 10 first compares the read maximum brightness of the mark portions 101 and 101 with reference brightness as a threshold value stored in advance in the ROM. If the maximum luminance is smaller than the reference luminance, it is determined that the first platen roller 97b is floating from the platen glass 80, and the floating amount calculation unit 12 calculates the floating amount from the maximum luminance (step ST25, step ST25). ST30). For example, the floating amount is calculated by comparing the maximum luminance of the read mark portions 101 and 101 with a table in which a reference luminance previously associated with the floating amount is stored, and calculating the floating amount therefrom.

  Next, the scanner controller 10 compares the read mark widths of the mark portions 101 and 101 with a reference width as a threshold value stored in advance in the ROM. When the mark width is larger than the reference width, it is determined that the document feeding unit 9 is attached to be inclined with respect to the reader unit 8, and the inclination direction of the first platen roller 97b is detected. The inclination amount calculation unit 11 calculates the inclination amount from the mark width (step ST45, step ST50, step ST55). For example, the inclination amount is calculated by comparing the mark widths of the read mark portions 101 and 101 with a table in which a reference width previously associated with the inclination amount is stored, and calculating the inclination amount therefrom.

  When the calculation of the floating amount and the tilt amount is completed, the scanner controller 10 displays the calculated floating amount and the tilt amount on the display unit 17 (position shift information display step), and the scanner controller 10 related to the calculation of the floating amount and the tilt amount. This completes the control operation (step ST60 to step ST75).

  As described above, the copying machine 1 according to the first embodiment is provided with the pair of mark portions 101 and 101 in the axially invalid area of the first platen roller 97b, and the pair of mark portions 101 together with the first platen roller 97b. , 101 are read in the main scanning direction to obtain luminance distribution information. Therefore, the copying machine 1 according to the first embodiment can simultaneously detect the tilt information and the floating information. Then, by calculating the tilt amount of the document feeder 9 with respect to the reader unit 8 and the float amount of the first platen roller 97b with respect to the platen glass 80 from the acquired tilt information and float information, not only the tilt amount but also the float amount is calculated. Can be easily obtained. Further, by displaying this, for example, even an operator with little work experience can adjust only by looking at the calculated tilt amount and floating amount, and when attaching the document feeding unit 9 to the reader unit 8 The adjustment time required for the process can be shortened. Thereby, an operator's burden can be reduced.

Second Embodiment
Next, an image reading apparatus 1A according to a second embodiment of the present invention will be described with reference to FIG. 10 to FIG. An image reading apparatus 1A according to the second embodiment is different from the first embodiment in the shape of the mark portion provided on the first platen roller 97b. Therefore, in the second embodiment, the difference from the first embodiment, that is, the shape of the mark portion will be mainly described, and the same components as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be given. Omitted.

  FIG. 10 is a plan view showing the first platen roller 97b according to the second embodiment. FIG. 11A is a diagram illustrating a state in which the document feeding unit 9 is normally attached to the reader unit 8. FIG. 11B is a diagram illustrating a state where the document feeding unit 9 is attached to be inclined to the right. FIG. 11C is a diagram illustrating a state where the document feeding unit 9 is attached to be inclined to the left.

  As shown in FIG. 10, the mark portions 201 and 201 of the first platen roller 97b according to the second embodiment are formed in a lightning-like shape (hereinafter referred to as “lightning shape”). Here, FIG. 11A to FIG. 11C illustrate luminance distribution information in the main scanning direction of the first platen roller 97b according to the second embodiment.

  For example, when the first platen roller 97b is in a normal state, the mark portions 201 and 201 are in the state shown in FIG. Therefore, in the invalid area where the mark portions 201 and 201 are located, the reference width (the left side is narrow and the right side is wide) set to the left and right in the main scanning direction, and the brightness of the surface of the first platen roller 97b is set. Luminance distribution information having reference luminance that is a predetermined amount lower than the value is obtained. Also, the luminance distribution information of the reference luminance that is lower by a predetermined amount is acquired at the same time on the left and right.

  Next, in a state where the first platen roller 97b is inclined to the right side, the mark portions 201 and 201 are in the state shown in FIG. That is, in the invalid area where the mark parts 201 and 201 are located, the right side is narrower than the reference width in the main scanning direction from the normal time, and the reference luminance that is lower by a predetermined amount is acquired at the timing when the right side can be sent. On the other hand, in a state where the first platen roller 97b is inclined to the left side, the mark portions 201 and 201 are in the state shown in FIG. That is, in the invalid area in which the mark portions 201 and 201 are located, the reference luminance on the left side is wider than the reference width in the main scanning direction and the reference luminance lower by a predetermined amount than the normal time is acquired at the timing when the left side is sent.

  As described above, even when the mark portion has a lightning bolt shape like the mark portions 201 and 201 of the first platen roller 97b according to the second embodiment, the same effects as those of the first embodiment can be obtained.

  The detection control operation by the scanner controller 10 that calculates the inclination amount of the document feeding unit 9 with respect to the reader unit 8 and the floating amount of the first platen roller 97b with respect to the platen glass 80 described above is formed as a program according to the above procedure. It can also be configured to be executed by a computer such as a CPU. In addition, such a program can be configured to be accessed by a recording medium such as a semiconductor memory, a magnetic disk, an optical disk, a floppy (registered trademark) disk, or a computer in which the recording medium is set and to execute the program. It is.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above. In addition, the effects described in the embodiments of the present invention only list the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention.

  For example, in the present embodiment, the positional deviation information has been described using the amount of inclination of the document feeding unit 9 with respect to the reader unit 8 and the amount of floating of the first platen roller 97b with respect to the platen glass 80. It is not limited. The positional deviation information may be only the tilt amount or only the floating amount.

  Further, for example, in the first embodiment, it is configured to determine whether it is inclined to the left or right at the timing of detecting the intersection 102. However, the present invention is not limited to this. For example, in the luminance distribution information obtained when the first platen roller is tilted, it is possible to determine the left or right tilt direction based on whether the reference width in the main scanning direction is wider on the left or right side. Good. Thereby, it is possible to simultaneously detect the tilt information and the floating information in one scan.

1 Copying machine (image forming device)
3 Image forming unit 7 Image reading unit (image reading device)
8 Reader unit 9 Document feeding unit 10 Scanner controller (control unit)
17 Display part 70 Hinge part (position adjustment mechanism)
83 Image sensor unit (image reading means)
89a Drive motor 90 Document feeder 97b First platen roller (platen roller)
101 Mark (mark)
D Manuscript

Claims (8)

Image reading means capable of reading the luminance distribution on the scanning line;
A document feeding device having a platen roller disposed opposite to the scanning line of the image reading means and capable of feeding a document to the image reading means;
An image forming apparatus comprising: a position adjustment mechanism capable of adjusting a position of the document feeder relative to the image reading unit;
On the surface of the platen roller, two or more marks with a luminance different from the surface of the platen roller are provided in the axial direction,
The image reading unit reads the surface of the platen roller and the mark in the scanning line direction to acquire luminance distribution information on the scanning line, and the acquired luminance distribution information in the scanning line direction is used for the image reading unit. A control unit that calculates misregistration information of the document feeder;
A display unit for displaying positional deviation information calculated by the control unit,
An image forming apparatus. The control unit calculates an inclination amount and a floating amount with respect to the image reading unit of the document feeder from the luminance distribution information on one scanning line.
The image forming apparatus according to claim 1. The mark is provided outside the reading area of the document in the axial direction of the platen roller.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The mark is configured to be removable from the platen roller.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. An original feeding apparatus having an image reading unit capable of reading a luminance distribution on a scanning line, and a platen roller disposed to face the scanning line of the image reading unit, and capable of feeding an original to the image reading unit In a method for detecting a position of a document feeder that detects a displacement of the document feeder relative to the image reading unit in an image forming apparatus comprising:
The image reading means reads the surface of the platen roller and marks provided at two or more locations in the axial direction of the platen roller in the scanning line direction, and brightness distribution information on the scanning line is obtained. A luminance distribution acquisition step to acquire;
A positional deviation information calculating step of calculating positional deviation information of the document feeder relative to the image reading unit from luminance distribution information in the scanning line direction acquired by the luminance distribution acquiring step;
A displacement information display step for displaying the displacement information calculated by the displacement information calculation step,
A method for detecting a position of a document feeder. The positional deviation information calculation step calculates an inclination amount and a floating amount with respect to the image reading unit of the document feeder from the luminance distribution information on one scanning line.
6. A method for detecting a position of a document feeder according to claim 5, wherein: The mark is provided outside the reading area of the document in the axial direction of the platen roller.
The position detection method for a document feeder according to claim 5 or 6. The mark is configured to be removable from the platen roller.
The position detection method for a document feeder according to claim 5 or 6.

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