JP2024021937A - Image reading device and image forming device - Google Patents

Abstract

An image reading device and an image forming apparatus equipped with the same are provided, which can reduce the possibility that a rotating member for detecting a sheet will be damaged during maintenance or jam removal of a reading unit. SOLUTION: The image forming apparatus 101 is rotatable between a closed position that covers the reading unit 307 when viewed from above, and an open position that exposes the reading unit 307 when viewed from above. The sheet detection unit 600 includes a rotation guide member 500 supported by a housing 316 and a sheet detection unit 600 having a flag member 601 rotatably provided. The flag member 601 is arranged at a position where the contact portion 602 is exposed when viewed from above with the rotation guide member 500 in the open position. The contact portion 602 has a first inclined surface 602a and a second inclined surface 602b that are formed so as to approach each other in the axial direction as the contact portion 602 moves away from the rotating shaft portion 603 in an orthogonal direction perpendicular to the axial direction of the rotating shaft portion 603. has. [Selection diagram] Figure 10

Description

The present invention relates to an image reading device that reads images on a sheet, and an image forming apparatus equipped with the same.

Conventionally, an image reading device installed in an image forming apparatus such as a copying machine is an automatic document feeder (hereinafter referred to as ADF) that conveys sheets of originals placed on a document tray one by one. It is known that it has the following. When disposing a reading unit that reads images on sheets inside such an ADF, the sheet transport path should be arranged so that the glass surface of the reading unit is exposed to the outside of the device in order to clean the glass surface facing the sheet and clear jams. may be configured to be openable. Patent Document 1 describes a configuration in which an opening/closing member forming the top surface of the device and a guide member forming the sheet conveyance path of the ADF are rotatable in order to expose the glass surface of the reading unit to the outside of the device. There is.

Further, some ADFs include a detection unit that detects sheets in the sheet conveyance path in order to control conveyance and detect jams. As such a detection unit, one is known that includes a rotating member that rotates when pressed by a sheet being conveyed, and a sensor that detects the sheet by detecting the rotation of the rotating member. (Patent Document 2).

Japanese Patent Application Publication No. 2005-194011 Japanese Patent Application Publication No. 2007-22706

In a configuration in which the conveyance path can be opened as in Patent Document 1, a rotating member for detecting a sheet may be exposed to the outside of the apparatus when the sheet conveyance path is opened. In such a case, there is a risk that an operator's hand or a cleaning tool may come into contact with the rotating member and be damaged during maintenance or jam removal of the reading unit.

SUMMARY OF THE INVENTION Therefore, the present invention provides an image reading apparatus and an image forming apparatus equipped with the image reading apparatus that can reduce the possibility that a rotating member for detecting a sheet is damaged during maintenance of the reading unit or jam removal. The purpose is to provide.

One aspect of the present invention includes a housing, a placing portion on which a sheet is placed, a feeding member feeding the sheet placed on the placing portion, and a sheet fed by the feeding member. a conveyance member that conveys the sheet along a conveyance path; a reading unit that reads an image of the sheet conveyed by the conveyance member; and a first guide that guides the sheet facing the upper surface of the sheet conveyed by the conveyance member. an opening/closing member having a surface and rotatably supported by the housing; and a second guide surface that faces the lower surface of the sheet conveyed by the conveyance member and forms the conveyance path together with the first guide surface. and is supported by the housing so as to be rotatable between a first position that covers the reading unit when viewed from above and a second position that exposes the reading unit when viewed from above. A detection unit that includes a guide member and a rotating member that is rotatably provided, and that detects a sheet when the rotating member rotates when pressed by the sheet conveyed by the conveying member. , the rotating member has a rotating shaft portion and a contact portion that comes into contact with the sheet conveyed by the conveying member, and when viewed from above with the guide member located at the second position. The abutting portions are arranged at positions where the abutting portions are exposed, and the abutting portions are formed so that the abutting portions move closer to each other in the axial direction as they move away from the rotating shaft in an orthogonal direction perpendicular to the axial direction of the rotating shaft. An image reading device characterized in that the image reading device has a first surface and a second surface.

Further, another aspect of the present invention includes a housing, a placing portion on which a sheet is placed, a feeding member feeding the sheet placed on the placing portion, and a feeding member configured to A conveyance member that conveys the fed sheet along a conveyance path, a reading unit that reads an image of the sheet conveyed by the conveyance member, and a sheet that guides the sheet facing the upper surface of the sheet conveyed by the conveyance member. an opening/closing member that is rotatably supported by the housing, and that faces a lower surface of the sheet conveyed by the conveying member and forms the conveyance path together with the first guide surface. The casing has a second guide surface and is rotatable between a first position that covers the reading unit when viewed from above and a second position that exposes the reading unit when viewed from above. a detection unit that has a guide member supported by a guide member and a rotating member that is rotatably provided, and that detects a sheet by rotating the rotating member when pressed by the sheet conveyed by the conveying member; and the rotating member has a rotating shaft portion and a contact portion that contacts the sheet conveyed by the conveying member, and the rotating member has a rotating shaft portion and a contact portion that comes into contact with the sheet conveyed by the conveying member, and when the guide member is located at the second position, A first surface is disposed at a position where the abutting portions are exposed when viewed from above, and the abutting portions are formed to approach each other in the axial direction of the rotation shaft portion as the abutting portions move toward the upstream side in the conveyance direction. and a second surface.

According to the present invention, an image reading device and an image forming apparatus equipped with the same are provided, which can reduce the possibility that a rotating member for detecting a sheet is damaged during maintenance of a reading unit or jam removal. can be provided.

FIG. 1 is a schematic cross-sectional view of an image forming apparatus. FIG. 2 is a perspective view of an image reading device. FIG. 2 is a schematic cross-sectional view of an image reading device. FIG. 3 is a perspective view of the ADF with the opening/closing cover open. FIG. 3 is a perspective view of the ADF with the opening/closing cover and rotation guide member open. FIG. 3 is a side view of the ADF with the rotation guide member closed. FIG. 3 is a side view of the ADF with the rotation guide member open. FIG. 3 is a sectional view of a reading unit and a reading guide member. FIG. 3 is a perspective view of the ADF with the opening/closing cover and rotation guide member open. FIG. 3 is an enlarged view of the vicinity of the contact portion of the flag member according to the first embodiment. FIG. 3 is a cross-sectional view of the ADF near the flag member according to the first embodiment. FIG. 2 is a perspective view of a flag member according to the first embodiment. FIG. 7 is an enlarged view of the vicinity of the contact portion of the flag member according to the second embodiment. FIG. 7 is a perspective view of a flag member according to a second embodiment.

[First embodiment]
Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the following embodiments are examples of embodying the present invention, and do not limit the technical scope of the present invention.

<Image forming device>
First, an image forming apparatus 100 according to the present embodiment will be described using FIG. 1. FIG. 1 is a schematic cross-sectional view of the image forming apparatus 100 when viewed from the front.

As shown in FIG. 1, the image forming apparatus 100 includes an image forming apparatus main body 104 and an image reading device 101 provided above the image forming apparatus main body 104. The image forming apparatus 100 forms a toner image on a sheet P according to image data read by the image reading apparatus 101 or an image signal from a host device such as a personal computer communicably connected to the image forming apparatus 100. Examples of the paper P, which is a recording medium, include sheet materials such as plain paper, plastic film, and cloth.

Inside the image forming apparatus main body 104, there are provided laser scanners 107 to 110, image forming units 111 to 114, and a fixing unit 118, which are image forming units using an electrophotographic method, and which correspond to each color of YMCK. Laser scanners 107 to 110 irradiate laser beams toward photoreceptors included in corresponding image forming units 111 to 114, respectively, in accordance with input image signals. These image forming units 111 to 114 are arranged along an intermediate transfer belt 115.

In the image forming unit 111, a yellow toner image is formed, and the formed yellow toner image is primarily transferred onto the intermediate transfer belt 115. In the image forming unit 112, a magenta toner image is formed, and the formed magenta toner image is primarily transferred onto the intermediate transfer belt 115 so as to be superimposed on the yellow toner image. In the image forming unit 113, a cyan toner image is formed, and the formed cyan toner image is primarily transferred onto the intermediate transfer belt 115 so as to be superimposed on the yellow and magenta toner images. In the image forming unit 114, a black toner image is formed, and the formed black toner image is primarily transferred onto the intermediate transfer belt 115 so as to be superimposed on the yellow, magenta, and cyan toner images.

A paper feed cassette 105 is arranged at the bottom of the image forming apparatus main body 104 so as to be able to be pulled out to the front side. The image forming apparatus 100 uses a pickup roller 106 to feed the paper P stored in the paper feed cassette 105 toward the secondary transfer nip portion where the intermediate transfer belt 115 and the secondary transfer portion 116 are in contact with each other. When conveying the paper P, the image forming apparatus 100 conveys the paper P in synchronization with the toner image on the intermediate transfer belt 115. Then, the multiple toner images on the intermediate transfer belt 115 are transferred onto the paper P at the secondary transfer nip section by the action of the secondary transfer bias voltage applied to the secondary transfer section 116.

The paper P on which the toner image has been secondarily transferred in the secondary transfer section 116 is conveyed to the fixing unit 118 by the conveyance belt 117 . Then, the paper P is heated and pressurized by the fixing unit 118 to fix the toner image, and after the toner image is fixed on the surface, the paper P is discharged to the paper discharge tray 119.

In this embodiment, the image forming apparatus 100 includes an electrophotographic image forming means, but the image forming means is not limited to this, and may be other image forming means such as an inkjet method.

<Image reading device>
Next, the image reading device 101 will be explained using FIGS. 2 and 3. FIG. 2 is a perspective view of the image reading device 101, and FIG. 3 is a schematic cross-sectional view of the image reading device 101. The image reading device 101 includes a reader 103 and an ADF 102 provided above the reader 103. The image reading device 101 also includes a control unit 101a, and the control unit 101a controls sheet conveyance in the ADF 102 based on a signal from a sheet detection unit 600, which will be described later. The ADF 102 is rotatably supported with respect to the reader 103 by a hinge (not shown) provided on the back side of the device. The image reading device 101 performs an operation of reading image information from a still document placed on the document table glass 318 of the reader 103 (fixed reading operation), and an operation of reading image information while conveying a sheet as a document by the ADF 102 (flowing operation). reading operation).

As shown in FIG. 3, the reader 103 has an original platen glass 318 on which an original is placed, and a document placed on the original platen glass 318 while moving in the sub-scanning direction (horizontal direction in the figure) below the original platen glass 318. and a reading unit 306 that reads image information of the original document. The reader 103 also has a first scanning glass 312 . The reading unit 306 can read image information by optically scanning the document conveyed by the ADF 102 via the first panning glass 312 while being stopped below the first panning glass 312 .

The reading unit 306 includes a sensor substrate 309 on which a CCD image sensor as a light receiving element is mounted, a light source 310 that irradiates light onto a document, and a plurality of mirrors 308 that guide reflected light from the document to an imaging surface of the light receiving element. , has.

The ADF 102 includes a document tray 200, an ejection tray 201 disposed below the document tray 200, and a reading unit 307. In the ADF 102, a feeding roller 300, a pair of separating rollers 301, pairs of conveying rollers 302, 303, 304, and a pair of discharge rollers 305 are arranged along a sheet conveying path P1 along which sheets are conveyed. The document tray 200 is a loading section on which sheets as documents are placed, and the discharge tray 201 is a discharge and stacking section on which sheets with image information read are discharged. Note that the transport roller pairs 303 and 304 and the discharge roller pair 305 as transport members are rotatably supported inside a casing 316 that includes the exterior of the ADF 102 and a sheet metal. Further, the document tray 200 is configured to be rotatable about a rotation axis (not shown) with respect to the housing 316, and when the user rotates the document tray 200 upward, the document tray 200 is It is possible to easily take out the original.

The reading unit 307 includes a contact image sensor (hereinafter referred to as CIS 311) as a reading section and a second scanning glass 313. The second panning glass 313 is a first transparent member that transmits light from the document, and the CIS 311 reads image information of the document conveyed through the sheet conveyance path P1 via the second panning glass 313. Further, the reading unit 307 is rotatably supported by the casing 316 of the ADF 102 via a rotation shaft 314.

When a user sets a stack of originals on the original tray 200 and instructs the start of a reading operation via an operation unit (not shown), a feeding roller 300 serving as a feeding member feeds the original into the sheet conveying path P1 in order from the topmost original. It will be done. The delivered document is separated one by one by a pair of separation rollers 301, and is conveyed through a sheet conveyance path P1 while passing through pairs of conveyance rollers 302, 303, and 304 in order. Then, when the document passes through the first scanning glass 312, image information on the first side (front surface) of the document is read by the reading unit 306. Similarly, when passing through the second scanning glass 313, the reading unit 307 reads image information on the second side (back side) of the document, which is opposite to the first side. The document whose image information has been read is discharged to the outside of the ADF 102 by a pair of discharge rollers 305 as a discharge member, and is stacked on the discharge tray 201. Note that the first side of the document is the top surface when the document is placed on the document tray 200, and the second side of the document is the bottom surface when the document is placed on the document tray 200.

The ADF 102 includes an opening/closing cover 315 that forms the top surface of the device. An opening/closing cover 315 serving as an opening/closing member is rotatably (openably/closably) supported by the casing 316 of the ADF 102 via a rotation shaft 319 . The opening/closing cover 315 is provided with an upper guide 315a that forms a sheet conveyance path P1 together with a lower guide 500a of a rotation guide member 500, which will be described later. Here, the upper guide 315a is a first guide surface that faces the upper surface of the sheet fed by the feeding roller 300 and guides the sheet. Further, the lower guide 500a is a second guide surface that faces the lower surface of the sheet fed by the feeding roller 300 and guides the sheet. The open/close cover 315 is fixed to the housing 316 by a locking mechanism (not shown) in the closed position (the position shown in FIG. 2). When the user pulls up the opening/closing lever 315b when opening the opening/closing cover 315, a locking mechanism (not shown) is released and the opening/closing cover 315 can be opened.

In the closed state of the opening/closing cover 315, the rotation guide member 500 is covered from above by the opening/closing cover 315. Further, the opening/closing cover 315 is provided with a feeding roller 300, a pair of separating rollers 301, and one (upper side in the figure) of a pair of conveying rollers 302. Therefore, when the opening/closing cover 315 rotates upward from the closed position and moves to the open position, a part of the sheet conveyance path P1 is opened and the rotation guide member 500 is exposed to the outside of the ADF 102, as will be described later. The rotation guide member 500 is now in a state where it can be rotated.

<About cleaning the glass>
While the image reading device 101 repeats the scanning operation, foreign matter consisting of dust such as paper powder and stains such as glue and ink attached to the original adheres to the first scanning glass 312 and the second scanning glass 313. There are cases where If a scanning operation is performed with a foreign object attached within the reading range of the reading units 306 and 307 on the first scanning glass 312 and the second scanning glass 312, the foreign object will not exist in the original document at the position corresponding to the foreign object. A striped image is read. This is a phenomenon (hereinafter referred to as image streaks) that occurs when the optical path during reading by the reading units 306 and 307 is blocked by foreign matter attached to the first scanning glass 312 and the second scanning glass 313, resulting in shadows. It is.

In order to eliminate the occurrence of image streaks, it is effective to properly clean the first scanning glass 312 and the second scanning glass 313 to remove foreign substances that are the cause. Regarding the reading unit 306 of the reader 103, the first scanning glass 312 is exposed by rotating the ADF 102 upward from the reader 103, so that the user can clean it from above. On the other hand, the reading unit 307 of the ADF 102 is arranged inside the housing 316. As shown in FIG. 3, in the present embodiment, the reading unit 307 is disposed below the rotation guide member 500 and in an area inside the sheet conveyance path P1 curved in a U-shape. Therefore, a configuration for exposing the second scanning glass 313 to the outside of the apparatus (a means for making the second scanning glass 313 accessible) is required. Therefore, in this embodiment, each of the rotation guide member 500 and the reading unit 307 is configured to be rotatable with respect to the housing 316, and the second scanning glass 313 of the reading unit 307 is exposed to the outside of the ADF 102. make it possible.

FIG. 4 is a perspective view of the image reading device 101 with the openable cover 315 open. FIG. 5 is a perspective view of the image reading device 101 with the opening/closing cover 315 and the rotation guide member 500 open. As described above, when the opening/closing cover 315 is in the closed state, the opening/closing cover 315 covers the upper part of the rotation guide member 500. On the other hand, as shown in FIG. 4, when the open/close cover 315 is in the open state, a part of the sheet conveyance path P1 is opened, and the rotation guide member 500 is exposed to the outside of the apparatus when viewed from above.

In this embodiment, the rotation guide member 500 is rotatably supported by the housing 316 of the ADF 102 via a rotation shaft 502 extending in the width direction orthogonal to the sheet conveyance direction. Here, the width direction is a direction along the main scanning direction of the reading units 306 and 307. The rotation guide member 500 has two positions: a closed position (the first position shown in FIG. 4) that covers the reading unit 307 when viewed from above, and an open position (the first position shown in FIG. 5) where the reading unit 307 is exposed to the outside of the apparatus when viewed from above. the second position). On the other hand, a fixed guide member 507 that guides the sheet continuously from the lower guide 500a of the rotation guide member 500 is fixed to the casing 316 of the ADF 102. As shown in FIG. 4, the fixed guide member 507 is a guide surface that is adjacent to the downstream end of the lower guide 500a, faces the upper guide 315a, and forms the sheet conveyance path P1.

Further, the reading unit 307 is configured to rotate in conjunction with the rotation of the rotation guide member 500. FIG. 6 is a side view of the ADF 102 when the rotation guide member 500 is in the closed state, and FIG. 7 is a side view of the ADF 102 when the rotation guide member 500 is in the open state. Note that in FIGS. 6 and 7, parts unnecessary for explanation are omitted. The ADF 102 has an arm member 501 for rotating the reading unit 307. An arm member 501 serving as an interlocking member is provided so as to be rotatable about a rotation shaft 502 as the rotation guide member 500 rotates. When the user rotates the rotation guide member 500 in the direction of arrow A, the arm member 501 also rotates in the direction of arrow A. When the arm member 501 rotates by a predetermined angle, the arm member 501 comes into contact with the reading unit 307. Then, the reading unit 307 is lifted up by the arm member 501 and rotates in the direction of arrow B around the rotation axis 314. By the above operation, the second scanning glass 313 of the reading unit 307 is exposed to the outside of the ADF 102, and the user can clean the second scanning glass 313 with a cleaning tool such as a non-woven cloth. Further, in a state where the rotation guide member 500 is in the open state and the reading unit 307 is rotated, the user can also clean the protective glass 404, which will be described later.

<Reading unit configuration>
Next, the configuration of the reading unit 307 will be described in detail using FIG. 8. FIG. 8 is a cross-sectional view of the reading unit 307 and the reading guide 403. The reading unit 307 has a first case member 400 and a second case member 401, and the CIS 311 is housed in the first case member 400 and the second case member 401. An opening 402 is provided on the surface of the first case member 400 on the side of the sheet conveyance path P1 in order to read image information of the conveyed sheet, and a second panning glass 313 is provided so as to cover the opening 402. is attached to the first case member 400.

On the other hand, a reading guide 403 is provided at a position facing the second panning glass 313. The reading guide 403 is fixed to the housing 316 and has a guide surface that faces the second scanning glass 313 and guides the sheet. The reading guide 403 is provided with a white sheet 405 and a protective glass 404. The white sheet 405 is a white reference member for performing shading correction of the CIS 311 before the reading unit 307 reads the image information of the document. The protective glass 404 is a second transparent member for preventing the surface of the white sheet 405 from being scratched.

<Sheet detection unit>
Next, the sheet detection unit 600 will be explained. FIG. 9 is a perspective view of the ADF 102 with the opening/closing cover 315 and the rotation guide member 500 in an open state and the reading unit 307 rotated, and shows the ADF 102 in the state shown in FIG. 5 from another angle. This is a drawing. FIG. 10 is an enlarged view of the vicinity of the contact portion 602 of the flag member 601. FIG. 11 is a sectional view of the ADF 102 near the flag member 601. FIG. 12 is a perspective view of the sheet detection unit 600.

The ADF 102 includes a sheet detection unit 600 as a detection section for detecting sheets being conveyed. The sheet detection unit 600 is a discharge sensor that detects a sheet at a detection position between the reading position of the reading unit 307 and the discharge roller pair 305 on the sheet conveyance path P1. As shown in FIG. 12, the sheet detection unit 600 includes a flag member 601, which is a rotating member that rotates when pressed by the conveyed sheet, and a photo interrupter 610, which is a sensor that detects the rotation of the flag member 601. ,have. The flag member 601 includes a rotation shaft portion 603 extending in the main scanning direction, a contact portion 602 formed to extend from the rotation shaft portion 603 in an orthogonal direction D orthogonal to the axial direction C (main scanning direction), It has a light shielding part 604 and flange parts 605 and 606. The contact portion 602 contacts the sheet conveyed on the sheet conveyance path P1. The light blocking section 604 blocks the optical path between the light emitting section 611 and the light receiving section 612 of the photointerrupter 610. The flange portions 605 and 606 restrict movement of the flag member 601 in the main scanning direction by coming into contact with a restriction portion (not shown) provided on the housing 316. The photointerrupter 610 switches ON/OFF of the signal transmitted to the control unit 101a depending on whether the optical path is blocked by the light blocking section 604 of the flag member 601 or the optical path is not blocked by the light blocking section 604.

As shown in FIG. 11, the ADF 102 includes transport guides 508 and 509 that form a sheet transport path P1 between the reading unit 307 and the pair of discharge rollers 305. The conveyance guide 508 is a fourth guide surface provided adjacent to the downstream side of the protective glass 404 in the conveyance direction, and faces the first surface of the sheet opposite to the second surface read by the reading unit 307. This is a guide surface that guides the sheet. On the other hand, the conveyance guide 509 is a third guide surface provided on the opposite side of the lower guide 500a of the rotation guide member 500, and faces the conveyance guide 508 when the rotation guide member 500 is in the closed state. It is located like this.

The flag member 601 is arranged such that the contact portion 602 protrudes from an opening 508a formed in the conveyance guide 508 into the sheet conveyance path P1. Further, the flag member 601 is arranged at a position where the contact portion 602 is exposed to the outside of the ADF 102 when viewed from above when the open/close cover 315 and the rotation guide member 500 are in the open state. Further, the contact portion 602 is arranged on the downstream side of the protective glass 404 in the conveyance direction. The leading edge of the sheet conveyed by the pair of conveyance rollers 304 comes into contact with the contact portion 602 after passing through the reading position of the reading unit 307 . As shown in FIG. 11, the contact portion 602 rotates about the rotation shaft portion 603 so as to fall down toward the downstream side in the conveying direction by being pressed by the sheet. At this time, the rotation of the rotation shaft portion 603 causes the light shielding portion 604 of the flag member 601 to move to a position where it does not block the optical path of the photointerrupter 610. As a result, the output signal of the photo interrupter 610 is switched, and the sheet detection unit 600 can detect the sheet.

Next, the shape of the contact portion 602 will be explained. As shown in FIG. 12, the contact portion 602 is formed with a first inclined surface 602a (first surface) and a second inclined surface 602b (second surface) that extend in the direction along the conveyance direction. The first inclined surface 602a and the second inclined surface 602b are planes inclined with respect to both the axial direction C and the orthogonal direction D, and as they move away from the rotation shaft portion 603 in the orthogonal direction D, they approach each other in the axial direction C. It's slanted like that. Furthermore, a connecting surface 602c that smoothly connects the first inclined surface 602a and the second inclined surface 602b is formed on the contact portion 602 on the upstream side of the first inclined surface 602a and the second inclined surface 602b in the conveyance direction. has been done. The connection surface 602c is a surface that the sheet in the contact portion 602 contacts. The connecting surface 602c includes a curved surface section continuous from the upstream side of the first inclined surface 602a, a curved surface section continuous from the upstream side of the second inclined surface 602b, and a flat section continuous from these two curved surface sections. Ru. The first inclined surface 602a and the second inclined surface 602b are inclined so that they approach each other the further away from the rotation shaft 603, so the width of the connecting surface 602c in the axial direction C becomes smaller as the distance from the rotation shaft 603 increases. . That is, the contact portion 602 has a shape that becomes thinner toward the tip, and the shape of the contact portion 602 is approximately triangular when viewed from the conveyance direction.

By the way, as shown in FIG. 9, the flag member 601 is arranged at a position where the contact portion 602 is exposed to the outside of the ADF 102 when viewed from above when the opening/closing cover 315 and the rotation guide member 500 are in the open state. There is. As described above, when the opening/closing cover 315 and the rotation guide member 500 are in the open state, the user can clean the second scanning glass 313 and the protective glass 404. For example, the user cleans the second scanning glass 313 and the protective glass 404 by pressing the nonwoven fabric against the area to be cleaned and moving it in the main scanning direction. At this time, the user's hand may come into contact with the contact portion 602 of the flag member 601. However, in this embodiment, when a force in the main scanning direction is applied to the first inclined surface 602a or the second inclined surface 602b, the flag member 601 rotates in the same direction as when detecting a sheet. In other words, the flag member 601 is configured to be retractable when a force in the direction along the axial direction C is applied to the contact portion 602. Thereby, it is possible to reduce the possibility that the flag member 601 will be damaged when the user cleans the second scanning glass 313 and the protective glass 404.

Note that in this embodiment, the first inclined surface 602a and the second inclined surface 602b are flat, but the first inclined surface 602a and the second inclined surface 602b may have a shape other than a flat surface, such as a curved surface.

[Second embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIGS. 13 and 14. The second embodiment has a configuration in which only the shape of the contact portion 602 of the flag member 601 is changed from the first embodiment, so the description of the same configuration as the first embodiment will be omitted. do.

FIG. 14 shows a flag member 701 as a rotating member of the sheet detection unit 600 according to the second embodiment. The flag member 701 includes a rotating shaft portion 703 extending in the main scanning direction, an abutting portion 702 extending in an orthogonal direction D perpendicular to an axial direction C of the rotating shaft portion 703, a light shielding portion 704, and flange portions 705, 706. It has . The contact portion 702 contacts the sheet conveyed on the sheet conveyance path P1. The light blocking section 704 blocks the optical path between the light emitting section 611 and the light receiving section 612 of the photointerrupter 610. The flange portions 705 and 706 restrict movement of the flag member 701 in the main scanning direction by coming into contact with a restriction portion (not shown) provided on the housing 316.

The contact portion 702 is formed with a first inclined surface 702a (first surface) and a second inclined surface 702b (second surface) extending in the orthogonal direction D. As shown in FIG. 13, the first inclined surface 702a and the second inclined surface 702b are planes inclined with respect to the conveyance direction, and are inclined so as to approach each other toward the upstream side in the conveyance direction. Furthermore, a connecting surface 702c that smoothly connects the first inclined surface 702a and the second inclined surface 702b is formed on the contact portion 702 on the upstream side of the first inclined surface 702a and the second inclined surface 702b in the conveying direction. ing. The connection surface 702c is a surface that the sheet in the contact portion 702 contacts. The connecting surface 702c includes a curved surface portion continuous from the upstream side of the first sloped surface 702a, a curved surface portion continuous from the upstream side of the second sloped surface 702b, and a flat portion continuous from these two curved surface portions. Ru. When viewed from the orthogonal direction D, the shape of the contact portion 702 is approximately triangular.

As shown in FIG. 13, the flag member 701 is arranged at a position where the contact portion 702 is exposed to the outside of the ADF 102 when viewed from above when the open/close cover 315 and the rotation guide member 500 are in the open state. In such a configuration, when a force in the main scanning direction is applied to the first inclined surface 702a or the second inclined surface 702b, the flag member 701 rotates in the same direction as when detecting a sheet. Thereby, as in the first embodiment, it is possible to reduce the possibility that the flag member 701 will be damaged when the user cleans the second scanning glass 313 and the protective glass 404.

100 Image forming device 101 Image reading device 102 ADF
103 Reader 306, 307 Reading unit 312 First scanning glass 313 Second scanning glass 315 Opening/closing cover 500 Rotation guide member 600 Sheet detection unit 601, 701 Flag member 602, 702 Contact portion 602a, 702a First inclined surface 602b , 702b second slope

Claims (11)

A casing and
a placing section on which the sheet is placed;
a feeding member that feeds the sheet placed on the loading section;
a conveying member that conveys the sheet fed by the feeding member along a conveying path;
a reading unit that reads an image of a sheet conveyed by the conveyance member;
an opening/closing member rotatably supported by the housing, the opening/closing member having a first guide surface that guides the sheet opposite to the upper surface of the sheet conveyed by the conveying member;
a second guide surface that faces the lower surface of the sheet conveyed by the conveyance member and forms the conveyance path together with the first guide surface; a first position that covers the reading unit when viewed from above; a guide member supported by the housing so as to be rotatable between a second position in which the reading unit is exposed when viewed;
a detection unit that includes a rotatable member that is rotatably provided, and detects a sheet by rotating the rotary member when pressed by the sheet conveyed by the conveying member;
Equipped with
The rotation member has a rotation shaft portion and a contact portion that contacts the sheet conveyed by the conveyance member, and the rotation member has the rotation shaft portion and the contact portion that contacts the sheet conveyed by the conveyance member, and the rotation member It is placed in a position where the contact part is exposed,
The contact portion has a first surface and a second surface that are formed to approach each other in the axial direction as the contact portion moves away from the rotation shaft in an orthogonal direction perpendicular to the axial direction of the rotation shaft.
An image reading device characterized by: The first surface and the second surface are planes extending in a direction oblique to the orthogonal direction and the axial direction,
The image reading device according to claim 1, characterized in that: The contact portion connects the first surface and the second surface on the upstream side in the conveyance direction, and has a connection surface that comes into contact with the sheet conveyed by the conveyance member,
The width of the connecting surface in the axial direction becomes smaller as the distance from the rotation axis increases in the orthogonal direction.
The image reading device according to claim 1, characterized in that: The detection section includes a sensor having a light emitting section and a light receiving section,
The rotating member has a light shielding part that blocks an optical path between the light emitting part and the light receiving part.
The image reading device according to claim 1, characterized in that: comprising an ejection member that ejects the sheet whose image has been read by the reading unit,
The detection unit detects the sheet at a detection position between the reading position of the reading unit and the ejection member on the conveyance path.
The image reading device according to claim 1, characterized in that: The reading unit has a transparent member that transmits light from the sheet, and is rotatable so that the transparent member is exposed when viewed from above with the guide member located at the second position.
The image reading device according to claim 1, characterized in that: The transparent member is a first transparent member,
The housing includes a white reference member for the reading unit to perform shading correction, and a second transparent member that covers the white reference member with respect to the transport path,
The rotating member is arranged such that the contact portion is located downstream of the second transparent member in the sheet conveyance direction.
The image reading device according to claim 6, characterized in that: The guide member has a third guide surface that guides the sheet on the opposite side of the second guide surface,
The casing has a fourth guide surface that is provided adjacent to the downstream side of the second transparent member in the sheet conveyance direction and forms the conveyance path together with the third guide surface,
The contact portion is arranged to protrude into the conveyance path from an opening formed in the fourth guide surface.
The image reading device according to claim 7, characterized in that: comprising an interlocking member that rotates the reading unit in conjunction with the rotation of the guide member;
The image reading device according to claim 6, characterized in that: A casing and
a placing section on which the sheet is placed;
a feeding member that feeds the sheet placed on the loading section;
a conveying member that conveys the sheet fed by the feeding member along a conveying path;
a reading unit that reads an image of a sheet conveyed by the conveyance member;
an opening/closing member rotatably supported by the housing, the opening/closing member having a first guide surface that guides the sheet opposite to the upper surface of the sheet conveyed by the conveying member;
a second guide surface that faces the lower surface of the sheet conveyed by the conveyance member and forms the conveyance path together with the first guide surface; a first position that covers the reading unit when viewed from above; a guide member supported by the housing so as to be rotatable between a second position in which the reading unit is exposed when viewed;
a detection unit that includes a rotatable member that is rotatably provided, and detects a sheet by rotating the rotary member when pressed by the sheet conveyed by the conveying member;
Equipped with
The rotation member has a rotation shaft portion and a contact portion that contacts the sheet conveyed by the conveyance member, and the rotation member has the rotation shaft portion and the contact portion that contacts the sheet conveyed by the conveyance member, and the rotation member It is placed in a position where the contact part is exposed,
The contact portion has a first surface and a second surface that are formed to approach each other in the axial direction of the rotation shaft portion as it goes upstream in the conveyance direction.
An image reading device characterized by: An image reading device according to any one of claims 1 to 10,
an image forming means for forming an image on a recording medium based on the image read by the reading unit;
An image forming apparatus characterized by:

Images