Image reading device and image forming system

Abstract

To reduce the possibility that damage to a member occurs.SOLUTION: An image reading device comprises: a reading unit that has a transparent member and reading means; and an opposing unit that has a contact part in contact with the transparent member. The reading unit is removable from an apparatus main body toward one side of a sheet width direction orthogonal to a sheet conveyance direction of a sheet. The opposing unit is movable to a first position where the contact part is in contact with the transparent member and a second position where the contact part is separated from the transparent member. The opposing unit has a regulation part that, when the opposing unit is at the first position, regulates a movement of the reading unit to one side of the sheet width direction, and when the opposing unit is at the second position, permits the movement of the reading unit to one side of the sheet width direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an image reading device that reads image information from a sheet and an image forming system that forms an image on a sheet. [Background technology]

[0002] An image reading device that reads image information while conveying a sheet includes a contact glass, an image sensor that acquires image information of the sheet through the contact glass, and an opposing unit that faces the contact glass. The opposing unit includes a member that faces the contact glass, such as a guide member that guides the conveyed sheet so that it comes into contact with the contact glass, or a roller member that conveys the sheet while guiding it. Here, if the distance between the opposing unit and the contact glass is too wide, the sheet may pass a position away from the contact glass, thereby reducing the reading accuracy of the image sensor.

[0003] Patent Document 1 describes that a reading guide member facing the contact glass is provided so as to be movable in a direction approaching and moving away from the contact glass, and is biased toward the contact glass by a coil spring. The contact glass is disposed in the main body of the document reading device, and the reading guide member is disposed in a document transport device that can be opened and closed relative to the main body. When the document transport device is closed, a part of the reading guide member abuts against the contact glass, thereby positioning the reading guide member relative to the contact glass. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-89216 A Summary of the Invention [Problem to be solved by the invention]

[0005] The reading unit including the contact glass is configured to be detachable from the device body for cleaning or part replacement. However, in the above-mentioned document, if the reading unit is removed while the reading guide member is in contact with the contact glass, there is a possibility that the contact glass may be damaged.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS In view of the above, an object of the present invention is to provide an image reading device and an image forming system that are capable of reducing the possibility of damage to components. [Means for solving the problem]

[0007] One aspect of the present invention is an image reading device including a reading unit having a transparent member and a reading means for reading image information from a conveyed sheet through the transparent member, and an opposing unit having an abutment portion that abuts against the transparent member and faces the transparent member across a space through which the sheet passes, wherein the reading unit is removable from the device body toward one side in a sheet width direction perpendicular to a sheet conveying direction of the sheet, the opposing unit is movable between a first position where the abutment portion abuts against the transparent member and a second position where the abutment portion is separated from the transparent member, and the opposing unit has a regulating portion that regulates movement of the reading unit toward the one side in the sheet width direction when the opposing unit is located at the first position and allows movement of the reading unit toward the one side in the sheet width direction when the opposing unit is located at the second position. death , the opposing unit is supported at the other side in the sheet width direction by the device body, and is rotatable about an axis in the sheet conveying direction so that an end portion of the opposing unit on the one side in the sheet width direction is separated from the transparent member. The image reading device is characterized in that Another aspect of the present invention is a first reading unit having a first transparent member and a first reading means for reading image information from a first surface of a sheet being transported through the first transparent member, a first opposing unit having a first abutment portion that abuts the first transparent member and faces the first transparent member across a space through which the sheet passes, a second transparent member provided downstream of the first transparent member in the sheet transport direction of the sheet, and a second transparent member that reads image information from a second surface of the sheet being transported that is opposite to the first surface of the sheet being transported through the first transparent member. and a second opposing unit having a second abutting portion that abuts against the second transparent member and faces the second transparent member across a space through which the sheet passes. The first reading unit and the second reading unit are removable from a device body toward one side in a sheet width direction perpendicular to the sheet conveying direction, and the first opposing unit is removable from a device body toward one side in a sheet width direction perpendicular to the sheet conveying direction, and the first abutting portion of the first opposing unit faces the first transparent member. the second opposing unit is movable to a first position where the first abutment portion abuts against the second transparent member and a second position where the first abutment portion is spaced apart from the first transparent member, the second opposing unit is movable to a third position where the second abutment portion abuts against the second transparent member and a fourth position where the second abutment portion is spaced apart from the second transparent member, the first opposing unit restricts movement of the first reading unit to the one side in the sheet width direction when the first opposing unit is located at the first position, the second opposing unit has a first regulating portion that restricts movement of the second reading unit to the one side in the sheet width direction when the second opposing unit is located at the third position, and the second opposing unit has a second regulating portion that restricts movement of the second reading unit to the one side in the sheet width direction when the second opposing unit is located at the fourth position, and allows movement of the second reading unit to the one side in the sheet width direction when the second opposing unit is located at the fourth position. Effect of the Invention

[0008] According to the present invention, the possibility of damage to members can be reduced. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an image forming system according to an embodiment of the present disclosure. [Diagram 2] FIG. 4 is a schematic diagram of an adjustment unit according to the embodiment. [Diagram 3] FIG. 2 is a schematic diagram of a double-sided reading unit according to the embodiment. [Figure 4] FIG. 3 is a cross-sectional view of a first reading unit according to the embodiment. [Diagram 5] FIG. 4 is a cross-sectional view illustrating a state in which a backing unit of the first reading unit according to the embodiment is closed. [Figure 6] FIG. 4 is a cross-sectional view illustrating a state in which a backing unit of the first reading unit according to the embodiment is open. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, exemplary embodiments according to the present disclosure will be described with reference to the drawings.

[0011] 1 is a schematic diagram showing an image forming system 100S according to an embodiment. The image forming system 100S includes an image forming apparatus 100, an adjustment unit 400, and a finisher 600. The adjustment unit 400 is an example of an image reading apparatus that reads image information from a sheet, and the finisher 600 is an example of a sheet processing apparatus that processes the sheet.

[0012] An image forming engine 102 as an image forming means and a main controller for controlling the operation of an image forming system 100S including the image forming apparatus 100 are mounted in a housing 101 of the image forming apparatus 100. The image forming engine 102 of this embodiment includes an optical processing mechanism and a fixing processing mechanism for forming an image on a recording material by an electrophotographic process, and a feeding processing mechanism and a conveying processing mechanism for feeding and conveying a sheet 110 used as the recording material. As the recording material, various sheet materials having different materials, thicknesses, sizes, shapes, etc., such as paper such as plain paper or thick paper, paper with a surface treatment such as coated paper or embossed paper, plastic film, or cloth, can be used.

[0013] The optical processing mechanism includes stations 120, 121, 122, and 123 that form toner images of each color of yellow, magenta, cyan, and black, and an intermediate transfer belt 106. In each of the stations 120 to 123, a primary charger 111 charges the surface of a photosensitive drum 105, which is a drum-shaped image carrier (electrophotographic photosensitive member). The laser scanner unit 107 performs exposure processing of the photosensitive drum 105 based on a command signal that is generated based on image data and transmitted to the laser scanner unit 107. The laser scanner unit 107 has a laser driver that drives a laser beam emitted from a semiconductor laser (not shown) to turn on and off, and guides the laser beam from the semiconductor laser to the photosensitive drum 105 via a reflecting mirror 109 while distributing it in the main scanning direction by a rotating polygon mirror. As a result, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 105.

[0014] The developing unit 112 contains a developer containing toner therein, and supplies charged toner particles to the photosensitive drum 105. The toner particles adhere to the drum surface in accordance with the surface potential distribution, and the electrostatic latent image carried on the photosensitive drum 105 is developed (visualized) as a toner image. The toner image carried on the photosensitive drum 105 is transferred (primary transfer) to the intermediate transfer belt 106 by a primary transfer roller to which a voltage of a polarity opposite to the normal charging polarity of the toner is applied. When a color image is formed, the toner images formed by the four stations 120 to 123 are multiple-transferred so as to be superimposed on each other on the intermediate transfer belt 106, forming a full-color toner image on the belt.

[0015] On the other hand, the feeding process mechanism feeds sheets 110 one by one from a storage 113 inserted retractably into a housing 101 of the image forming apparatus 100 toward a transfer roller 114. A toner image carried on an intermediate transfer belt 106, which is an intermediate transfer body, is transferred (secondary transfer) onto the sheet 110 by the transfer roller 114.

[0016] Around the intermediate transfer belt 106, there are arranged a start position detection sensor 115 for determining a print start position when forming an image, a feed timing sensor 116 for timing the feeding of the sheet 110, and a density sensor 117. The density sensor 117 measures the density of a patch image carried on the intermediate transfer belt 106. The main controller adjusts the operating conditions of the optical processing mechanism (for example, the setting of the charging target potential of the primary charger 111 and the bias voltage of the developer 112) based on the detection result of the density sensor 117.

[0017] The fixing mechanism of this embodiment is composed of a first fixing device 150 and a second fixing device 160. The first fixing device 150 includes a fixing roller 151 for applying heat to the sheet 110, a pressure belt 152 for pressing the sheet 110 against the fixing roller 151, and a first post-fixing sensor 153 for detecting the completion of the fixing process by the first fixing device 150. Each roller including the fixing roller 151 is a hollow roller and has a heater inside. The first fixing device 150 applies heat and pressure to the toner image on the sheet while conveying the sheet 110 by nipping it between the fixing roller 151 and the pressure belt 152, which are a pair of rotating bodies. This melts the toner particles, which then stick to each other, and the image is fixed to the sheet 110.

[0018] The second fixing device 160 is disposed downstream of the first fixing device 150 in the conveying path of the sheet 110. The second fixing device 160 has a function of increasing the glossiness of the image fixed by the first fixing device 150 and ensuring fixability of the image to the sheet 110. Like the first fixing device 150, the second fixing device 160 has a fixing roller 161 and a pressure roller 162 as a pair of rotating bodies that heat and pressurize the sheet 110 while conveying it, and a second post-fixing sensor 163 that detects the completion of the fixing process by the second fixing device 160.

[0019] Depending on the type of sheet 110, there may be cases where it is not necessary to pass the sheet 110 through the second fixing device 160. In such cases, the image forming apparatus 100 has a bypass conveying path 130 for discharging the sheet 110 without passing through the second fixing device 160 in order to reduce energy consumption. The sheet 110 sent out from the first fixing device 150 is guided by a first switching flap 131 to either the second fixing device 160 or the bypass conveying path 130.

[0020] The sheet 110 that has passed through the second fixing device 160 or the bypass conveying path 130 is guided by the second switching flap 132 to either the discharge conveying path 139 or the reverse conveying path 135. The position of the sheet 110 that has been conveyed to the reverse conveying path 135 is detected by the reverse sensor 137, and the leading end and trailing end in the sheet conveying direction are swapped by the switchback operation performed by the reverse unit 136. In the case of double-sided printing, the sheet 110 with an image formed on its first side is transported again toward the transfer roller 114 via the re-conveying path 138 with its leading and trailing ends swapped by the reverse unit 136, and an image is formed on its second side. The sheet 110 with the image formation completed in single-sided printing or the sheet 110 with the image formation completed in double-sided printing is discharged to the outside of the image forming apparatus 100 via the discharge conveying path 139. In addition, a switching flap 134 capable of guiding the sheet 110 switched back by the reversing unit 136 toward the discharge conveying path 139 is provided between the reversing conveying path 135 and the discharge conveying path 139. By providing the switching flap 134, it is possible to select the front or back of the sheet 110 when it is discharged from the image forming apparatus 100.

[0021] An original reading device 190 is installed on the top of the image forming apparatus 100. The original reading device 190 includes a main body portion fixed to a housing 101 of the image forming apparatus 100, and an automatic document feeder (hereinafter referred to as ADF). The ADF includes a feed tray on which original sheets are placed, and a discharge tray onto which the original sheets from which image information has been read are discharged. The original sheets set on the feed tray are fed and transported one by one by a feeding unit. During this time, the original sheets are optically scanned by an image sensor to read the image information of the sheets. The original sheets from which image information has been read are discharged onto the discharge tray by a pair of discharge rollers.

[0022] The image forming apparatus 100 is provided with an operation unit 180 that serves as a user interface for the image forming system 100S (see also FIG. 1). The operation unit 180 has a display as a display means for displaying information to a user. The operation unit 180 also has physical keys such as a numeric keypad and a print execution button, and a touch panel function of a display, as input means by which a user can input commands and data to the image forming system 100S. By operating the operation unit 180, a user can input information indicating sheet attributes such as the name, basis weight, and whether or not the sheet is surface-treated, of a sheet set in a certain storage 113, to the main controller. The input sheet attributes are registered in a sheet library 900 stored in the memory 304.

[0023] 1, an intermediate transfer type color image forming apparatus has been described, but a direct transfer type image forming engine that transfers a toner image formed on an image carrier to a sheet without using an intermediate transfer body may be installed. Also, the image forming means is not limited to the electrophotographic type, and may be, for example, an inkjet type printing unit or an offset printing mechanism.

[0024] (Adjustment unit) Next, a description will be given of the adjustment unit 400. The adjustment unit 400 functions as an image reading device that reads image information in a double-sided reading section 500 from a sheet on which an image has been formed by the image forming apparatus 100. The adjustment unit 400 of this embodiment is used to adjust the execution conditions of an image forming operation performed by the image forming apparatus 100, as will be described later.

[0025] 1, the adjustment unit 400 is installed between the image forming apparatus 100 and the finisher 600 in the horizontal direction (left-right direction in the figure). That is, in this embodiment, the upstream device of the adjustment unit 400 is the image forming apparatus 100, and the downstream device of the adjustment unit 400 is the finisher 600. The finisher 600 has a processing section that performs processing such as binding processing or saddle processing on sheets, and discharges the processed sheet stack (or the sheets received from the upstream device when no processing is required) as a deliverable of the image forming system 100S.

[0026] The devices connected upstream and downstream of the adjustment unit 400 vary depending on the configuration of the image forming system 100S. For example, the adjustment unit 400 is not necessarily directly connected to the image forming apparatus 100, and an intermediate unit may be disposed between the image forming apparatus 100 and the adjustment unit 400, and the adjustment unit 400 may receive the sheet through the intermediate unit. An example of the intermediate unit is a device that performs a coating process to attach a transparent toner to the image surface of the image-formed sheet to give it gloss. In addition, a sheet processing device other than the finisher 600 may be connected downstream of the adjustment unit 400. Examples of such sheet processing devices include an inserter that inserts a sheet to be a cover into a sheet stack, a trimmer that cuts and aligns the ends of a bound sheet stack, and a stacker that can be moved by a cart while storing a large amount of products. In addition, the adjustment unit 400 may be configured to include a discharge tray that discharges sheets as products of the image forming system 100S (a configuration in which the finisher 600 is omitted from FIG. 1).

[0027] 2, the adjustment unit 400 includes a double-sided reading section 500, and a through path 431 and a discharge path 432 that configure a sheet transport path within the adjustment unit. In addition, a discharge tray 430 and an extension tray 423 that can be pulled out from the discharge tray 430 are provided on the upper portion of the housing of the adjustment unit 400.

[0028] The through path 431 is a transport path that receives a sheet discharged from the image forming apparatus 100 and transports the sheet toward the finisher 600, and extends in a substantially horizontal direction. In the through path 431, an entrance roller pair 401 and an exit roller pair 406 are arranged.

[0029] The double-sided reading unit 500 is disposed between the entrance roller pair 401 and the exit roller pair 406 in the through path 431. The double-sided reading unit 500 includes a first reading unit 510 that reads image information from a first surface of the sheet (the lower surface of the sheet in the through path 431), and a second reading unit 520 that reads image information from a second surface of the sheet (the upper surface of the sheet in the through path 431) opposite to the first surface. The double-sided reading unit 500 also includes a first conveying roller pair 501, a second conveying roller pair 502, and a third conveying roller pair 503 as conveying means that convey the sheet through the first reading unit 510 and the second reading unit 520. The detailed configurations of the first reading unit 510 and the second reading unit 520 will be described later.

[0030] The discharge path 432 branches off from the through path 431 and extends upward. In the discharge path 432, a first conveying roller pair 415, a second conveying roller pair 416, a third conveying roller pair 417, and a discharge roller pair 418 are arranged in this order from upstream to downstream in the sheet conveying direction of the discharge path 432. At the branch point between the discharge path 432 and the through path 431, a switching flap 422 is arranged as a guide member capable of switching the sheet conveying path between the through path 431 and the discharge path 432. The switching flap 422 is arranged downstream of the double-sided reading unit 500 and upstream of the exit roller pair 406 in the sheet conveying direction in the through path 431. The switching flap 422 can perform control such that, for example, a sheet on which a normal image is formed is conveyed to a downstream device via the exit roller pair, and a sheet on which a test image for adjusting the execution conditions of the image forming operation is formed is discharged to the discharge tray 430 via the discharge path. The transport path configuration of the adjustment unit 400 shown in the figure is an example, and the double-sided reading unit 500 may be arranged by providing a transport path that branches off from the through path 431 and then merges with the through path 431.

[0031] (Double-sided reading section) The double-sided reading section 500 will be described with reference to FIG. 3. FIG. 3 is a schematic diagram of the double-sided reading section 500 as viewed in the sheet width direction D2. The sheet width direction D2 is a direction perpendicular to the sheet conveying direction D1 and the sheet thickness direction D3 (FIG. 7) in the first reading section 510, and is also a main scanning direction when reading an image in the first reading section 510. The sheet conveying direction D1 is also a sub-scanning direction when reading an image perpendicular to the main scanning direction. The sheet thickness direction D3 is a direction perpendicular to the sheet conveying direction D1 and the sheet width direction D2 in the first reading section 510, and is also a depth of field direction at the reading position of the first reading section 510. In this embodiment, the sheet conveying direction, the sheet width direction, and the sheet thickness direction in the second reading section 520 are substantially the same as the sheet conveying direction D1, the sheet width direction D2, and the sheet thickness direction D3 in the first reading section 510.

[0032] The first reading section 510 of the double-sided reading section 500 includes a reading unit C1 and a backing unit B1 facing the reading unit C1. Similarly, the second reading section 520 includes a reading unit C2 and a backing unit B2 facing the reading unit C2. The reading unit C1 has reading glasses 703 and 704 as transparent members, and CISs 701 and 702 as reading means for optically scanning the sheet P through the reading glasses 703 and 704 to read image information. The reading glasses are also called contact glasses or platen glasses. The backing unit B2 has backing rollers 801 and 802 facing the reading glasses 703 and 704 in the sheet thickness direction D3, and gap adjustment cams 803 and 823 described below.

[0033] The reading glass 703, the CIS 701, and the reading unit C1 are the first transparent member, the first reading means, and the first reading unit of this embodiment. The reading glass 704, the CIS 702, and the reading unit C2 are the second transparent member, the second reading means, and the second reading unit of this embodiment. The gap adjustment cam 803 and the backing unit B1 are the first abutment portion and the first opposing unit of this embodiment, and the gap adjustment cam 823 and the backing unit B2 are the second abutment portion and the second opposing unit of this embodiment.

[0034] As shown in FIG. 4, the CIS 701, 702 includes an irradiation unit 701a, a condensing lens 701b, and a light receiving element 701c, and has the following configuration, for example. The irradiation unit 701a irradiates light toward a reading gap 431G (a part of the through path 431) which is a space through which a sheet passes. The irradiation unit 701a includes an LED as a light source installed on a substrate, and a light guide that extends in the sheet width direction D2 from a position facing the LED and irradiates light from the LED to substantially the entire area of ​​the reading gap 431G in the sheet width direction D2. The condensing lens 701b condenses reflected light from the sheet passing through the reading gap 431G, and forms an image on the light receiving surface of the light receiving element 701c. The condensing lens 701b is a lens array in which cylindrical equal-magnification lenses are arranged in the sheet width direction D2 in correspondence with each of the light receiving elements 701c. The light receiving element 701c is a CMOS sensor arranged on a substrate in the sheet width direction D2. Although the CIS 701 of the first reading unit 510 is shown in FIG. 4, the CIS 702 of the second reading unit 520 has a substantially similar configuration to the CIS 701.

[0035] As shown in FIG. 3, a reading gap 431G, which is a space (part of the through-path 431) through which the sheet P passes, is formed between the outer peripheral surfaces of the backing rollers 801, 802 facing each other in the sheet thickness direction D3 and the reading glasses 703, 704. The CIS 701 and the reading glass 703 constituting the reading unit C1 of the first reading section 510 are disposed on one side of the sheet thickness direction D3 with respect to the through-path 431 (the lower side in the configuration example of FIG. 3). The CIS 702 and the reading glass 704 constituting the reading unit C2 of the second reading section 520 are disposed on the other side of the sheet thickness direction D3 with respect to the through-path 431 (the upper side in the configuration example of FIG. 3). Therefore, the double-sided reading section 500 can read image information of the first and second sides (front and back) of the sheet P in parallel while the sheet P passes through the through-path 431 once.

[0036] The backing rollers 801, 802 are roller members that can rotate around a rotation axis extending in the sheet width direction D2. The backing rollers 801, 802 are members that form the background of the sheet P when the CISs 701, 702 read the image information of the sheet P, and have black outer circumferential surfaces. This makes the contrast between the sheet edge and the background clearer (brightness difference is greater) in the read image information, and image processing such as edge detection can be performed more stably.

[0037] The image forming system 100S of this embodiment can adjust the execution conditions of the image forming operation performed by the image forming apparatus 100 based on information acquired using the double-sided reading unit 500. For example, when aligning (registering) an image on a sheet, the image forming apparatus 100 outputs rectangular patch images at the four corners of both sides of the sheet, and calculates the position of the patch images with respect to the four sides of the sheet from the image information read by the double-sided reading unit 500. Parameters representing the position in the main scanning direction and sub-scanning direction of the image formed on the sheet by the image forming apparatus 100, the magnification, the rotation angle, etc. are adjusted so as to correct the error between the ideal image position and the actual patch image position. Then, the image forming operation to obtain a deliverable is performed using the adjusted parameters.

[0038] In the double-sided reading section 500, since it is desirable to average out the shape variation and print position variation of each sheet in order to obtain a highly accurate measurement result, multiple sheets are measured. Therefore, instead of a method of reading image information by moving the reading unit in the sub-scanning direction while keeping the sheet stationary, a method of reading image information while conveying the sheet is used to shorten the measurement time. In addition, in order to make the adjustment unit 400 as small as possible, the first reading section 510 and the second reading section 520 use contact image sensors (hereinafter referred to as CIS) 701, 702. Therefore, in order to improve the quality of the read image, it is desirable to regulate the passing position of the sheet in the depth of field direction (sheet thickness direction at the reading position) with high accuracy.

[0039] In this embodiment, the configuration in which the CIS is used as the reading means has been described, but the reading means may be a CCD image sensor including a reduction optical system including multiple mirrors and a CCD sensor as a light receiving element. Also, the reading means may be a spectrophotometer including a diffraction grating that separates the reflected light from the sheet into wavelengths and a light receiving element that measures the light intensity of each wavelength, and the adjustment unit 400 may be used to adjust the color tone (color matching) of the image forming apparatus 100. Furthermore, the image information read by the reading means may be used for purposes other than adjusting the execution conditions of the image forming operation, and for example, the read image information may be compared with the image data used in the image formation to perform inspection (management of image quality and detection of image defects).

[0040] (Backing unit) The configuration of the backing unit B1, which is the opposing unit of this embodiment, will be described with reference to Figs. 4 to 6. Fig. 4 is a cross-sectional view showing the cross section of the first reading section 510 in a virtual plane perpendicular to the sheet width direction D2 as viewed in the sheet width direction D2. Figs. 5 and 6 are cross-sectional views showing the cross section of the first reading section 510 in a virtual plane perpendicular to the sheet conveying direction D1 as viewed from the upstream side in the sheet conveying direction D1, Fig. 5 shows the backing unit B1 in a closed state, and Fig. 6 shows the backing unit B1 in an open state.

[0041] The following description will be given taking the backing unit B1 of the first reading unit 510 as an example. The backing unit B2 of the second reading unit 520 has substantially the same configuration as the backing unit B1 of the first reading unit 510, except that the positional relationship in the sheet thickness direction D3 with respect to the through path 431 is reversed.

[0042] As shown in FIGS. 4 and 5, the backing unit B1 includes a backing roller 801, a frame 815, a gap adjustment cam 803, a cam position sensor 812, a cam drive motor 813, and a roller drive motor 814.

[0043] The frame 815 is a frame of the backing unit B1, is supported by the adjustment unit 400, and supports other elements of the backing unit B1. The frame 815 extends in the sheet width direction D2, and has bearings 815b that rotatably support both ends of the roller shaft 808 of the backing roller 801. The backing roller 801 has a cylindrical main body 801a supported by the roller shaft 808, and the black outer circumferential surface of the main body 801a faces the reading glass 703. The main body 801a preferably extends in the sheet width direction D2 with a length that encompasses the entire range (maximum reading range) in which the CIS 701 can read image information in the sheet width direction D2.

[0044] A drive pulley 811 attached to a roller shaft 808 of the backing roller 801 is connected to an output pulley attached to the output shaft of a roller drive motor 814 via a timing belt 804. As a result, the backing roller 801 is rotated by the driving force of the roller drive motor 814.

[0045] The backing roller 801 is rotationally driven so that the peripheral speed of the main body 801a is equal to the sheet conveying speed of the other conveying roller pairs (the peripheral speeds of the first conveying roller pair 501 to the third conveying roller pair 503). By making the peripheral speed of the backing roller 801 equal to the sheet conveying speed (the scanning speed in the sub-scanning direction) in the double-sided reading section 500, the image on the sheet P is less likely to be rubbed against the backing roller 801, and the double-sided reading section 500 is less likely to become dirty.

[0046] The gap adjustment cams 803, which are the contact parts in this embodiment, are provided on both sides of the main body 801a of the backing roller 801 in the sheet width direction D2, and are supported by the roller shaft 808 in a state in which they can rotate relatively to the roller shaft 808. The gap adjustment cams 803 contact the reading glass 703 on their radially outer surfaces (cam surfaces) with respect to the roller shaft 808, thereby controlling (regulating) the distance from the reading glass 703 to the rotation axis of the backing roller 801 in the sheet thickness direction D3. That is, the gap adjustment cam 803 has a function of securing a reading gap 431G as a space through which the sheet P passes between the backing roller 801 and the reading glass 703, and also has a function of adjusting the width of the reading gap 431G in the sheet thickness direction D3.

[0047] As shown in FIG. 4, the gap adjustment cam 803 of this embodiment has a cam surface 803a that is an outer periphery whose distance from the rotation axis A1 of the backing roller 801 is not uniform. The cam surface 803a is formed in an elliptical shape that is eccentric with respect to the rotation axis A1 when viewed in the sheet width direction D2, for example. The cam surface 803a has a plurality of contact portions with different distances from the rotation axis A1, and includes at least five contact positions G1 to G5 in the illustrated example. Therefore, depending on the rotation angle of the gap adjustment cam 803, which of the contact positions G1 to G5 of the cam surface 803a contacts the reading glass 703 changes, and the width of the reading gap 431G is switched in five stages. The contact position G1 corresponds to the minimum value of the width of the reading gap 431G in this embodiment, and the width of the reading gap 431G increases in the order of the contact positions G2, G3, and G4, and the contact position G5 corresponds to the maximum value of the width of the reading gap 431G in this embodiment.

[0048] By changing the shape of cam surface 803a, the range in which the width of reading gap 431G can be changed can be changed, and the width may be switched in more or fewer stages than five stages. Also, for example, cam surface 803a may be formed in a shape that is asymmetrical in the left-right direction of Fig. 4. Also, gap adjustment cam 803 is an example of a mechanism that changes the width of reading gap 431G (width of the sheet conveying path), and the width of reading gap 431G may be changed using a mechanism other than a cam (for example, a solenoid).

[0049] 5, each gap adjustment cam 803 is connected to a cam drive motor 813 via a plurality of gears 805, 806, 807 and a connecting shaft 809. Therefore, the two gap adjustment cams 803 are synchronously driven to rotate by the driving force of the cam drive motor 813. In addition, a sensor flag 810 is attached to the connecting shaft 809 connecting the two gap adjustment cams 803, and a cam position sensor 812 is disposed at a position corresponding to the sensor flag 810. The cam position sensor 812 is an example of a detection means for detecting the rotation angle of the gap adjustment cam 803, and a photointerrupter that is shielded from light by the sensor flag 810 can be used.

[0050] The control unit of the adjustment unit 400 operates the gap adjustment cam 803 based on a detection signal from the cam position sensor 812. That is, the control unit switches the reading gap 431G to a desired width by controlling the cam drive motor 813 to drive and rotate the gap adjustment cam 803 to a target rotation angle and then stop the motor. The control unit of the adjustment unit 400 changes the width of the reading gap 431G in accordance with the thickness of the sheet P by performing the above control based on information (e.g., information on basis weight) of the sheet P used in the current image forming operation sent from the main controller of the image forming apparatus 100.

[0051] In addition, the gap adjustment cam 803 (or the backing roller 801) is urged toward the reading glass 703 in the sheet thickness direction D3 by a urging member such as a spring (not shown), thereby maintaining the gap adjustment cam 803 in contact with the reading glass 703.

[0052] (Removal and installation of the reading unit and regulation of the backing unit) Next, a method for attaching and detaching the reading units C1 and C2 and the restricting portions 815a and 825a provided on the backing units B1 and B2 will be described.

[0053] The reading units C1 and C2 of this embodiment are configured to be detachable from the device body 409 (FIG. 2) of the adjustment unit 400. The reading units C1 and C2 can be detached from the device body 409 by pulling them out from the mounting positions shown in FIGS. 5 and 6 toward one side in the sheet width direction D2 (the front side in FIG. 2). The reading units C1 and C2 are attached to the device body 409 by inserting them toward the other side in the sheet width direction D2. That is, the removal direction of the reading units C1 and C2 is a direction perpendicular to the sheet conveying direction D1, which is the front side in the front-rear direction of the adjustment unit 400. A front door 450 is provided on the side of the front side (one side in the sheet width direction D2) of the housing of the adjustment unit 400 as an openable and closable cover member (openable and closable member) to allow an operator to access the reading units C1 and C2 and the backing units B1 and B2. When the front door 450 is opened, at least a portion (preferably the entirety) of each of the reading units C1, C2 and the backing units B1, B2 is exposed when viewed from the front side of the adjustment unit 400, allowing the attachment / detachment operations and opening of the reading gaps described below to be performed.

[0054] First, the regulating section 815a capable of regulating the removal (pulling out) of the reading unit C1 will be described. As shown in Fig. 5, in a state in which a sheet can be transported to the double-sided reading section 500, the gap adjustment cam 803 of the backing unit B1 described above abuts against the reading glass 703 of the reading unit C1. Therefore, even if the front door 450 is opened, if the reading unit C1 is moved in the sheet width direction D2 in a state in which the gap adjustment cam 803 abuts against the reading glass 703, there is a possibility that the reading glass 703 will be rubbed against the gap adjustment cam 803 and damaged.

[0055] Therefore, the backing unit B1 of this embodiment is provided with a regulating portion 815a that regulates the movement of the reading unit C1 in the sheet width direction D2. The backing unit B1 is movable between a closed position (first position) where the gap adjustment cam 803 abuts against the reading glass 703 as shown in Fig. 5 and an open position (second position) where the gap adjustment cam 803 is separated from the reading glass 703 as shown in Fig. 6.

[0056] The regulating portion 815a is a part of the frame 815 of the backing unit B1, or is provided as a separate member fixed to the frame 815. The regulating portion 815a is located downstream of at least a part of the reading unit C1 in the removal direction (leftward in FIG. 5) of the reading unit C1, and overlaps with a part of the reading unit C1 (hereinafter, referred to as the regulated portion C1a) as viewed in the sheet width direction D2. That is, the regulating portion 815a is located at a position where it interferes with the movement trajectory (pulling movement line) of the reading unit C1 when it is removed when the backing unit B1 is in the closed position. Therefore, when the backing unit B1 is in the closed position where the gap adjustment cam 803 abuts against the reading glass 703, the removal of the reading unit C1 is regulated by the regulating portion 815a.

[0057] The restricting portion 815a is provided outside the maximum reading range of the CIS 701 in the sheet width direction D2, at an end portion on the front side of the frame 815 in the front-rear direction of the adjustment unit 400. The restricting portion 815a protrudes from the backing unit B1 side (upper side in FIG. 5) toward the reading unit C1 side (lower side in FIG. 5) in the sheet thickness direction D3 beyond the position of the surface of the reading glass 703 that rubs against the sheet. Therefore, a part of the reading glass 703 (or a part of the housing of the reading unit C1 that supports the reading glass 703) functions as the restricted portion C1a.

[0058] On the other hand, when the backing unit B1 is moved from the closed position to the open position, the gap adjustment cam 803 moves away from the reading glass 703 in the sheet thickness direction D3, and the restricting portion 815a also moves in the sheet thickness direction D3, as shown in Fig. 6. When the backing unit B1 moves from the closed position to the open position, the restricting portion 815a retreats from the position overlapping with the reading unit C1 as seen in the sheet width direction D2. In other words, the backing unit B1 can be opened to a position where the restricting portion 815a retreats from the movement trajectory (pulling out movement line) when the reading unit C1 is removed.

[0059] When the backing unit B1 is in the open position, the gap adjustment cam 803 is separated from the reading glass 703, so that the reading unit C1 can be moved toward one side in the sheet width direction D2 (the front side of the adjustment unit 400). In other words, the restriction portion 815a is configured to permit removal of the reading unit C1 (release the restriction) when the backing unit B1 is in the open position.

[0060] As described above, the opposing unit (backing unit B1) of this embodiment has a regulating portion 815a that regulates the movement of the reading unit (reading unit C1) to one side in the sheet width direction D2 when the opposing unit is located at the first position (closed position). The regulating portion 815a is configured to allow the reading unit to move to one side in the sheet width direction when the opposing unit is located at the second position (open position). This makes it possible to regulate, with a simple configuration, the reading unit from being removed when the opposing unit is located at the first position, and to reduce the possibility of damage to members such as the reading glass 701.

[0061] Similarly, a restricting portion 825a (FIG. 2) that restricts removal of the reading unit C2 is provided in the backing unit B2 of the second reading section 520. The restricting portion 815a is a first restricting portion of this embodiment, and the restricting portion 825a is a second restricting portion of this embodiment.

[0062] The regulating portion 825a is a part of the frame 825 of the backing unit B2, or is provided as a separate member fixed to the frame 825. The regulating portion 825a is provided outside the maximum reading range of the CIS 702 in the sheet width direction D2, at the end of the front side of the frame 825 in the front-rear direction of the adjustment unit 400. The regulating portion 825a protrudes beyond the position of the surface of the reading glass 704 that slides against the sheet from the backing unit B2 side (lower side in FIG. 2) toward the reading unit C2 side (upper side in FIG. 2) in the sheet thickness direction D3. Therefore, a part of the reading glass 704 (or a part of the housing of the reading unit C2 that supports the reading glass 704) functions as a regulated portion.

[0063] The backing unit B2 is movable between a closed position (third position) where the gap adjustment cam 823 abuts against the reading glass 704 and an open position (fourth position) where the gap adjustment cam 823 is separated from the reading glass 704.

[0064] When the backing unit B2 is in the closed position, the regulating portion 825a is located downstream of at least a part of the reading unit C2 in the removal direction of the reading unit C2, and overlaps with a part (regulated portion) of the reading unit C2 when viewed in the sheet width direction D2. In other words, the regulating portion 825a is located at a position that interferes with the movement trajectory (pulling out movement line) of the reading unit C2 when it is removed when the backing unit B2 is in the closed position. Therefore, when the backing unit B2 is in the closed position, the removal of the reading unit C2 is regulated by the regulating portion 825a.

[0065] When the backing unit B2 is moved from the closed position to the open position, the gap adjustment cam 823 moves away from the reading glass 704 in the sheet thickness direction D3, and the restricting portion 825a also moves in the sheet thickness direction D3. When the backing unit B2 moves from the closed position to the open position, the restricting portion 825a retreats from a position overlapping with the reading unit C2 as viewed in the sheet width direction D2. In other words, the backing unit B2 can be opened to a position where the restricting portion 825a retreats from the movement trajectory (removal movement line) when the reading unit C2 is removed.

[0066] When the backing unit B2 is in the open position, the gap adjustment cam 823 is separated from the reading glass 704. Therefore, the reading unit C2 can be moved toward one side in the sheet width direction D2 (the front side of the adjustment unit 400) without the reading glass 704 rubbing against the gap adjustment cam 823. In other words, the restricting portion 825a is configured to permit removal of the reading unit C1 (release the restriction) when the backing unit B1 is in the open position.

[0067] Here, the frames 815, 825 of the backing units B1, B2 are rotatably supported at their rear sides in the front-rear direction of the adjustment unit 400 (upstream side in the removal direction of the reading unit C1 in the sheet width direction D2) by the device main body 409. That is, the frames 815, 825 are connected near their rear ends to the frame of the device main body 409 via a support mechanism such as a hinge, and rotate around an axis in the sheet conveying direction D1.

[0068] Therefore, by rotating the backing units B1 and B2 so that the front ends of the backing units B1 and B2 are separated from the reading units C1 and C2 in the sheet thickness direction D3, the backing rollers 801 and 802 are separated from the reading glasses 703 and 704. An operator opens the front door 450 (FIG. 2) to access the backing units B1 and B2 from the front side of the adjustment unit 400 and perform the opening operation of the backing units B1 and B2. This opens the reading gap 431G (through path 431), making it easy to clear sheet jams and perform maintenance work in the double-sided reading section 500 from the front side of the adjustment unit 400.

[0069] Particularly, in this embodiment, the reading glasses 703, 704 are arranged along a through path 431 extending from one side surface to the other side surface in the horizontal direction of the adjustment unit 400, and the backing units B1, B2 are opened upward and downward within the device body. Therefore, in a configuration including two reading units C1, C2 that read image information from both sides of a sheet, the two backing units B1, B2 can be easily opened to clear sheet jams or perform maintenance work.

[0070] (Other embodiments) In the above embodiment, the backing rollers 801 and 802 are exemplified as an example of the opposing member, but the opposing member may have another configuration. For example, the opposing member may be a plate-like guide member having a predetermined width in the sheet conveying direction D1 and extending over the entire maximum reading range in the sheet width direction D2. Such a guide member may be biased toward the reading glasses 703 and 704 by a spring member. In addition, the surface of the opposing member is not limited to black, and may be white, which is a reference color for the white color of the image information read by the CIS 701 and 702, for example.

[0071] In the above embodiment, the adjustment unit 400 that is connected to the image forming apparatus 100 to form a part of the image forming system 100S has been described as an example of an image reading device. However, the present technology is also applicable to an image reading device (original reading device) that is installed on the top of a copying machine main body (a part where an image forming means such as an electrophotographic unit is mounted) in order to read image information of an original sheet in a copying machine. The present technology is also applicable to an image reading device such as a document scanner that is used independently of an image forming apparatus. [Explanation of symbols]

[0072] B1, B2... opposing unit, first opposing unit, second opposing unit (backing unit) / C1, C2... reading unit, first reading unit, second reading unit / 100... image forming apparatus / 100S... image forming system / 400... image reading apparatus (adjustment unit) / 701, 702... reading means, first reading means, second reading means (CIS) / 703, 704... transparent member, first transparent member, second transparent member (reading glass) / 801, 802... opposing member (backing roller) / 803, 823... abutment portion, first abutment portion, second abutment portion (gap adjustment cam) / 815a, 825a... regulation portion, first regulation portion, second regulation portion

Claims

1. a reading unit having a transparent member and a reading means for reading image information from a conveyed sheet through the transparent member; an opposing unit having a contact portion that contacts the transparent member and faces the transparent member across a space through which the sheet passes; An image reading device comprising: the reading unit is removable from the apparatus body toward one side in a sheet width direction perpendicular to a sheet conveying direction of the sheet, the facing unit is movable between a first position where the contact portion contacts the transparent member and a second position where the contact portion is separated from the transparent member, the opposing unit has a regulating portion that regulates movement of the reading unit to the one side in the sheet width direction when the opposing unit is located at the first position and allows movement of the reading unit to the one side in the sheet width direction when the opposing unit is located at the second position, the opposing unit is supported at the other side in the sheet width direction by the device body, and is rotatable about an axis in the sheet conveying direction so that an end portion of the opposing unit on the one side in the sheet width direction is separated from the transparent member.

1. An image reading apparatus comprising:

2. the contact portion is configured to be operable based on a command from a control portion of the image reading device to change a width of the space in a sheet thickness direction perpendicular to the sheet conveying direction and the sheet width direction.

2. The image reading apparatus according to claim 1, wherein the image reading apparatus comprises:

3. the facing unit includes a roller member having an outer circumferential surface facing the transparent member in the sheet thickness direction, the roller member rotating about an axis extending in the sheet width direction, The abutment portion is a cam that is provided so as to be rotatable relative to the shaft, a distance between an outer circumferential surface of the roller member and the transparent member in the sheet thickness direction is changed according to a rotation angle of the cam; 3. The image reading apparatus according to claim 2, wherein the image reading apparatus comprises:

4. A cover member is provided on one side surface of the device body in the sheet width direction so as to be openable and closable. By opening the cover member, access to the opposing unit and the reading unit is possible from the one side in the sheet width direction.

4. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

5. The opposing unit is an opposing member that faces the transparent member in a sheet thickness direction perpendicular to the sheet conveying direction and the sheet width direction and forms the space between the opposing member and the transparent member; a frame body extending in the sheet width direction, supporting the opposing member, and rotatably supported by the device main body; The regulating portion is provided at an end portion on the one side in the seat width direction of the frame body.

5. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

6. the regulating portion is disposed outside a maximum reading range in which the reading means can read image information in the sheet width direction, and when viewed in the sheet width direction, protrudes beyond the position of a surface of the transparent member that rubs against the sheet from the opposing unit side toward the reading unit side in the sheet thickness direction.

6. The image reading apparatus according to claim 5,

7. A first reading unit having a first transparent member and a first reading means for reading image information from a first surface of a sheet being conveyed through the first transparent member; a first opposing unit having a first contact portion that contacts the first transparent member and faces the first transparent member across a space through which the sheet passes; a second reading unit including a second transparent member provided downstream of the first transparent member in the sheet conveying direction of the sheet, and a second reading means for reading image information from a second surface of the sheet being conveyed, the second surface being opposite to the first surface, through the second transparent member; a second opposing unit having a second contact portion that contacts the second transparent member and faces the second transparent member across a space through which the sheet passes; An image reading device comprising: the first reading unit and the second reading unit are removable from the apparatus body toward one side in a sheet width direction perpendicular to the sheet conveying direction, the first opposing unit is movable between a first position where the first contact portion contacts the first transparent member and a second position where the first contact portion is separated from the first transparent member; the second opposing unit is movable between a third position where the second contact portion contacts the second transparent member and a fourth position where the second contact portion is separated from the second transparent member; the first opposing unit has a first regulating portion that regulates movement of the first reading unit to the one side in the sheet width direction when the first opposing unit is located at the first position and allows movement of the first reading unit to the one side in the sheet width direction when the first opposing unit is located at the second position; the second opposing unit has a second regulating portion that regulates movement of the second reading unit to the one side in the sheet width direction when the second opposing unit is located at the third position, and allows movement of the second reading unit to the one side in the sheet width direction when the second opposing unit is located at the fourth position.

1. An image reading apparatus comprising:

8. the first transparent member and the second transparent member are disposed along a conveying path extending from one side surface of the device body to the other side surface in a horizontal direction when viewed in the sheet width direction, the first opposing unit and the second opposing unit are configured to be moved upward or downward within the apparatus body so as to be separated from the first transparent member and the second transparent member, thereby opening the transport path; 8. The image reading apparatus according to claim 7,

9. the reading means is a contact image sensor including: an irradiation unit that irradiates light toward the space through which the sheet passes; a plurality of light receiving elements arranged in the sheet width direction and facing the space via the transparent member; and a lens that is arranged between the transparent member and the light receiving elements and that forms an image of the reflected light from the sheet on the light receiving surfaces of the plurality of light receiving elements.

7. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

10. an image forming apparatus for forming an image on a sheet; The image reading device according to claim 1 , which receives a sheet on which an image has been formed from the image forming device and reads image information from the sheet; An image forming system comprising:

Images