JP7612426B2 - Image reading device and image forming system - Google Patents

Description

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.

An image reading device that reads image information while conveying a sheet has 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 has 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 guides the sheet while conveying it. Here, if the distance between the opposing unit and the contact glass is too wide, the sheet may pass through a position away from the contact glass, reducing the reading accuracy of the image sensor.

Patent document 1 describes a reading guide member that faces the contact glass and is movable in a direction toward and 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.

JP 2009-89216 A

Incidentally, 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.

The present invention aims to provide an image reading device and an image forming system that can reduce the possibility of damage to components.

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 abutting portion that abuts against the transparent member and faces the transparent member across a space through which the sheet passes, the reading unit being 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 being movable between a first position where the abutting portion abuts against the transparent member and a second position where the abutting portion is separated from the transparent member, and the forward movement of the opposing unit is possible. The image reading device is characterized in that the opposing unit has a regulating portion that regulates movement of the reading unit to 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 one side in the sheet width direction when the opposing unit is located at the second position, and the opposing unit is supported on the other side in the sheet width direction by the device main body and is rotatable around an axis along the sheet conveying direction so that the end of the opposing unit on one side in the sheet width direction is away from the transparent member .
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 against 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. 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.

The present invention can reduce the possibility of damage to components.

1 is a schematic diagram of an image forming system according to an embodiment of the present disclosure. FIG. 4 is a schematic diagram of an adjustment unit according to the embodiment. FIG. 2 is a schematic diagram of a double-sided reading unit according to the embodiment. FIG. 2 is a cross-sectional view of a first reading unit according to the embodiment. FIG. 4 is a cross-sectional view illustrating a state in which a backing unit is closed of the first reading unit according to the embodiment. FIG. 11 is a cross-sectional view illustrating a state in which a backing unit of the first reading unit according to the embodiment is open.

Below, exemplary embodiments of the present disclosure are described with reference to the drawings.

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

The housing 101 of the image forming apparatus 100 is equipped with an image forming engine 102 as an image forming means, and a main controller that controls the operation of the image forming system 100S including the image forming apparatus 100. The image forming engine 102 of this embodiment includes an optical processing mechanism and a fixing processing mechanism that form an image on a recording material by an electrophotographic process, and a feeding processing mechanism and a transport processing mechanism that feed and transport a sheet 110 used as the recording material. As the recording material, a variety of sheet materials with different materials, thicknesses, sizes, shapes, etc., can be used, such as paper such as plain paper or cardboard, paper with a surface treatment such as coated paper or embossed paper, plastic film, or cloth.

The optical processing mechanism includes stations 120, 121, 122, and 123 that form toner images of each color, 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 turns on and off the laser light emitted from a semiconductor laser (not shown), and directs the laser light from the semiconductor laser to the photosensitive drum 105 via a reflecting mirror 109 while distributing it in the main scanning direction using 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.

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

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

Around the intermediate transfer belt 106, there are arranged a start position detection sensor 115 for determining the 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 the patch image carried on the intermediate transfer belt 106. The main controller adjusts the operating conditions of the optical processing mechanism (for example, the charging target potential of the primary charger 111 and the bias voltage setting of the developer 112) based on the detection result of the density sensor 117.

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.

The second fixing device 160 is disposed downstream of the first fixing device 150 in the transport path of the sheet 110. The second fixing device 160 has the function of increasing the glossiness of the image that has been subjected to the fixing process by the first fixing device 150 and ensuring the fixability of the image on 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 transporting it, and a second post-fixing sensor 163 that detects the completion of the fixing process by the second fixing device 160.

Depending on the type of sheet 110, it may not be necessary to pass it 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 the first switching flap 131 to either the second fixing device 160 or the bypass conveying path 130.

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 inversion conveying path 135. The position of the sheet 110 that has been conveyed to the inversion conveying path 135 is detected by the inversion sensor 137, and the leading and trailing ends in the sheet conveying direction are swapped by the switchback operation performed by the inversion unit 136. In the case of double-sided printing, the sheet 110 with an image formed on the first side is transported again toward the transfer roller 114 via the re-conveying path 138 with the leading and trailing ends swapped by the inversion unit 136, and an image is formed on the second side. The sheet 110 on which image formation has been completed in single-sided printing or the sheet 110 on which image formation has been 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 is provided between the reversing conveying path 135 and the discharge conveying path 139, which can guide the sheet 110 switched back by the reversing unit 136 toward 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 device 100.

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

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 the 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 the display, as input means by which the user can input commands and data to the image forming system 100S. By operating the operation unit 180, the user can input information indicating sheet attributes such as the name, basis weight, and whether or not the sheet has been surface-treated, of a sheet set in a certain storage 113, to the main controller. The input sheet attributes are registered in the sheet library 900 stored in the memory 304.

Note that while an intermediate transfer type color image forming device has been described in FIG. 1, it may also be equipped with 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. Also, it is not limited to electrophotographic type, and for example, an inkjet type printing unit or an offset printing mechanism may be installed as image forming means.

(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.

In the image forming system 100S of FIG. 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 or saddle processing on sheets, and discharges the processed sheet stack (or the sheets received from the upstream device if no processing is required) as the output of the image forming system 100S.

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).

As shown in FIG. 2, the adjustment unit 400 includes a double-sided reading section 500, and a through path 431 and a discharge path 432 that form a sheet transport path within the adjustment unit. In addition, the upper part of the housing of the adjustment unit 400 includes a discharge tray 430 and an extension tray 423 that can be pulled out from the discharge tray 430.

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

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 side of the sheet (the lower side of the sheet in the through path 431), and a second reading unit 520 that reads image information from a second side of the sheet (the upper side of the sheet in the through path 431) opposite to the first side. 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 for conveying 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.

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, which is a guide member that can switch the sheet conveying path between the through path 431 and the discharge path 432, is arranged. 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 control, for example, to convey a sheet on which a normal image is formed to a downstream device via the exit roller pair, and discharge a sheet on which a test image for adjusting the execution conditions of the image forming operation is formed to the discharge tray 430 via the discharge path. Note that the transport path configuration of the adjustment unit 400 shown in the figure is one 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, for example.

(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.

The first reading section 510 of the double-sided reading section 500 includes a reading unit C1 and a backing unit B1 that faces the reading unit C1. Similarly, the second reading section 520 includes a reading unit C2 and a backing unit B2 that faces 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 that optically scan 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 that face the reading glasses 703 and 704 in the sheet thickness direction D3, and gap adjustment cams 803 and 823, which will be described later.

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.

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 the reading gap 431G (part of the through path 431), which is a space through which the sheet passes. The irradiation unit 701a includes an LED as a light source installed on a substrate, and a light guide that extends from a position facing the LED in the sheet width direction D2 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 uses a CMOS sensor arranged in a row in the sheet width direction D2 on a substrate. Note that while FIG. 4 shows the CIS 701 of the first reading unit 510, the CIS 702 of the second reading unit 520 also has a substantially similar configuration to the CIS 701.

3, a reading gap 431G, which is a space through which the sheet P passes (part of the through-path 431), is formed between the outer peripheral surfaces of the backing rollers 801, 802, which face 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 unit 510 are arranged 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 unit 520 are arranged 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 unit 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.

The backing rollers 801, 802 are roller members that can rotate around a rotation axis that extends 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 their outer circumferential surfaces are black. This makes the contrast between the sheet edge and the background clearer (bigger brightness difference) in the read image information, and image processing such as edge detection can be performed more stably.

The image forming system 100S of this embodiment can adjust the execution conditions of the image forming operation performed by the image forming device 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 device 100 outputs rectangular patch images at the four corners of both sides of the sheet, and calculates the position of the patch images relative 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, 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 final product is performed using the adjusted parameters.

In the double-sided reading unit 500, multiple sheets are measured because it is desirable to average out the shape variations and print position variations for each sheet in order to obtain highly accurate measurement results. Therefore, instead of reading image information by moving the reading unit in the sub-scanning direction while keeping the sheet stationary, the measurement time is shortened by reading image information while conveying the sheet. In addition, in order to make the adjustment unit 400 as small as possible, the first reading unit 510 and the second reading unit 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.

In this embodiment, a configuration in which a 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 for each wavelength, and the adjustment unit 400 may be used to adjust the color (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).

(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 unit 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 unit 510 in a virtual plane perpendicular to the sheet conveying direction D1 as viewed from the upstream side of 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.

The following describes the backing unit B1 of the first reading unit 510 as an example. Except for the fact that the positional relationship in the sheet thickness direction D3 with respect to the through path 431 is reversed, the backing unit B2 of the second reading unit 520 has a substantially similar configuration to the backing unit B1 of the first reading unit 510.

As shown in Figures 4 and 5, the backing unit B1 has 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.

The frame 815 is the 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.

The drive pulley 811 attached to the 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.

The backing roller 801 is rotated 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 (scanning speed in the sub-scanning direction) in the double-sided reading unit 500, the image on the sheet P is less likely to rub against the backing roller 801, and the double-sided reading unit 500 is less likely to become dirty.

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 relative to the roller shaft 808. The gap adjustment cams 803 contact the reading glass 703 on their radially outer surfaces (cam surfaces) relative 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. In other words, the gap adjustment cam 803 has the function of securing the reading gap 431G as a space through which the sheet P passes between the backing roller 801 and the reading glass 703, and adjusting the width of the reading gap 431G in the sheet thickness direction D3.

As shown in FIG. 4, the gap adjustment cam 803 of this embodiment has a cam surface 803a, which 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 abutment portions with different distances from the rotation axis A1, and in the illustrated example, includes at least five abutment positions G1 to G5. Therefore, depending on the rotation angle of the gap adjustment cam 803, which of the abutment positions G1 to G5 of the cam surface 803a abuts against the reading glass 703 changes, and the width of the reading gap 431G switches in five stages. The contact position G1 corresponds to the minimum width of the reading gap 431G in this embodiment, and the width of the reading gap 431G increases in the order of contact positions G2, G3, and G4, with the contact position G5 corresponding to the maximum width of the reading gap 431G in this embodiment.

The range in which the width of the reading gap 431G can be changed can be changed by changing the shape of the cam surface 803a, and the width can be switched in more or fewer stages than five stages. For example, the cam surface 803a can be made asymmetric in the left-right direction of FIG. 4. The gap adjustment cam 803 is an example of a mechanism that changes the width of the reading gap 431G (width of the sheet transport path), and the width of the reading gap 431G can be changed using a mechanism other than a cam (for example, a solenoid).

As shown in FIG. 5, each gap adjustment cam 803 is connected to a cam drive motor 813 via multiple gears 805, 806, 807 and a connecting shaft 809. Therefore, the two gap adjustment cams 803 are synchronously rotated 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 may be a photointerrupter that is shielded from light by the sensor flag 810.

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

The gap adjustment cam 803 (or the backing roller 801) is biased toward the reading glass 703 in the sheet thickness direction D3 by a biasing member such as a spring (not shown), thereby keeping the gap adjustment cam 803 in contact with the reading glass 703.

(Installation and removal of the reading unit and regulation part 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.

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 removed from the device body 409 by pulling them out from the mounting positions shown in FIGS. 5 and 6 toward one side of 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 of 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. In addition, a front door 450 is provided on the side of the front side (one side of the sheet width direction D2) of the housing of the adjustment unit 400 as a cover member (opening/closing member) that can be opened and closed to allow the 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 all) 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 installation and removal operations and opening of the reading gap to be described below.

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, when 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 an attempt is made to move the reading unit C1 in the sheet width direction D2 while the gap adjustment cam 803 is abutting against the reading glass 703, there is a possibility that the reading glass 703 will rub against the gap adjustment cam 803 and be damaged.

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. In addition, the backing unit B1 is movable between a closed position (first position) in which the gap adjustment cam 803 abuts against the reading glass 703 as shown in FIG. 5, and an open position (second position) in which the gap adjustment cam 803 is separated from the reading glass 703 as shown in FIG. 6.

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 of the reading unit C1 (leftward in FIG. 5), and overlaps with a part of the reading unit C1 (hereinafter referred to as the regulated portion C1a) when viewed in the sheet width direction D2. In other words, the regulating portion 815a is located at a position that interferes with the movement trajectory (pulling 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 regulating portion 815a regulates the removal of the reading unit C1.

The regulating portion 815a is provided outside the maximum reading range of the CIS 701 in the sheet width direction D2, at the end of the front side of the frame 815 in the front-rear direction of the adjustment unit 400. The regulating portion 815a protrudes beyond the position of the surface of the reading glass 703 that rubs against the sheet, 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. 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 regulated portion C1a.

On the other hand, when the backing unit B1 is moved from the closed position to the open position, as shown in FIG. 6, the gap adjustment cam 803 moves away from the reading glass 703 in the sheet thickness direction D3, and the regulating portion 815a also moves in the sheet thickness direction D3. When the backing unit B1 moves from the closed position to the open position, the regulating portion 815a retreats from the position where it overlaps with the reading unit C1 when viewed in the sheet width direction D2. In other words, the backing unit B1 can be opened to a position where the regulating portion 815a retreats from the movement trajectory (removal line) when the reading unit C1 is removed.

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 regulating portion 815a is configured to allow the reading unit C1 to be removed (release the restriction) when the backing unit B1 is in the open position.

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

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

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 rubs 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 the regulated portion.

The backing unit B2 can also be moved between a closed position (third position) in which the gap adjustment cam 823 abuts against the reading glass 704, and an open position (fourth position) in which the gap adjustment cam 823 is separated from the reading glass 704.

When the backing unit B2 is in the closed position, the regulating portion 825a is located downstream of at least a portion of the reading unit C2 in the removal direction of the reading unit C2, and overlaps with a portion of the reading unit C2 (the regulated portion) when viewed in the sheet width direction D2. In other words, the regulating portion 825a is located in a position that interferes with the movement trajectory (removal 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.

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 regulating 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 regulating portion 825a retreats from a position overlapping with the reading unit C2 as seen in the sheet width direction D2. In other words, the backing unit B2 can be opened to a position where the regulating portion 825a retreats from the movement trajectory (removal line) when the reading unit C2 is removed.

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 allow the reading unit C1 to be removed (release the restriction) when the backing unit B1 is in the open position.

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

Therefore, by rotating the backing units B1 and B2 so that their front ends 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. The operator opens the front door 450 (Figure 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 easier to clear sheet jams and perform maintenance work in the double-sided reading section 500 from the front side of the adjustment unit 400.

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

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, it may be a plate-shaped guide member that has a predetermined width in the sheet conveying direction D1 and extends 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 CISs 701 and 702, for example.

In the above embodiment, the adjustment unit 400, which is connected to the image forming apparatus 100 to form 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 top of the main body of a copier (the part where an image forming means such as an electrophotographic unit is mounted) in order to read image information on original sheets in the copier. 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.

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 device/100S... image forming system/400... image reading device (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 (10)

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: 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: 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: a cover member provided openably and closably on one side surface of the device body in the sheet width direction, and 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 scanning apparatus . 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. 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 , a first reading unit including 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: 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 , 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. 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