JP2013146040A - Image reading device, and image forming apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of moving a CIS linearly and smoothly, and preventing the occurrence of paper jam.SOLUTION: An image reading device is configured to convey a document from a document mounting glass 43 to a leading edge of a single glass G via a document reading glass 42; and an edge 47b of a document guide unit 47 is arranged below an upper face of the document reading glass 42. Accordingly, a leading edge of a document does not get caught by the edge 47b of the document guide unit 47, which prevents the occurrence of paper jam.

Description

  The present invention relates to an image reading apparatus that reads a document or the like using a contact image sensor, and an image forming apparatus including the image reading apparatus.

  This type of image reading apparatus reads an original and is used alone or mounted on a copying machine or the like. When used alone, the image of the read original is output to an external printer or the like, and when used in a copying machine, the image of the read original is copied by the copying machine.

  As such an image reading apparatus, a document placing glass and a document reading glass are juxtaposed, and a contact image sensor (CIS (Contact Image Sensor)) is moved along the lower surface of the document placing glass, while the CIS is used. A first mode for reading a document placed on the document placement glass, and a second mode for positioning the CIS on the lower surface of the document reading glass and reading the document conveyed along the upper surface of the document reading glass by the CIS There is something that selectively performs.

  Here, as is well known, since the focal depth of the CIS is as shallow as about 0.4 mm, the CIS is often moved close to or in sliding contact with the lower surface of the document placement glass and the lower surface of the document reading glass. For this reason, if a step is formed between each glass instead of a uniform flat surface from the lower surface of the document placement glass to the lower surface of the document reading glass, the moving CIS comes into contact with the step and the CIS moves. The load fluctuated and the CIS movement became unstable.

  In view of this, a single single glass may be divided into a document placing glass region and a document reading glass region. In this single glass, there is no step between the document placing glass and the document reading glass, so that the CIS moving operation does not become unstable as described above.

  However, when the original is read in the second mode, the original is conveyed along the upper surface of the original reading glass. Therefore, in order to pick up the read original from the upper surface of the original reading glass, the guide member for scooping up the original is read. Must be attached to the upper surface of the original reading glass.

  However, when the guide member is affixed to the upper surface of the original reading glass, a step is formed between the end of the guide member and the upper surface of the original reading glass, and the leading edge of the original is caught in this step, causing jamming. There was something to do. By appropriately setting the shape of the guide member, it is possible to reduce such a step, but it is difficult to completely eliminate the step, and jamming caused by the step is also completely eliminated. I can't do it.

  On the other hand, in Patent Document 1, the guide member is attached to the upper surface of the original reading glass, and the flow reading glass is laminated on the upper surface of the original reading glass, and the surface of the flow reading glass is positioned higher than the end of the guide member. Arranged. In this case, the leading edge of the original conveyed along the upper surface of the flow reading glass is conveyed without being caught by the end of the guide member, and jamming does not occur.

  In Patent Document 2, a single glass sheet is divided into a document placement glass area and a document reading glass area, and a guide member is provided in a document transport section that can be opened and closed with respect to the glass. A recess is formed in the area of the document placement glass. Then, when the document conveying section is closed, the guide member is arranged in the area of the document placing glass, and the end of the guide member enters the concave portion between the end of the guide member and the upper surface of the document reading glass. No step is formed on the surface.

JP 2006-213353 A JP-A-7-191502

  However, when the flow-reading glass is pasted on the upper surface of the original reading glass as in Patent Document 1, the number of parts is increased.

  In addition, when the flow reading glass is stacked on the upper surface of the original reading glass, the thickness of the glass increases by the thickness of the flow reading glass. Therefore, in order to maintain a constant CIS separation distance for both the original on the flow reading glass and the original on the original placement glass, when reading the original on the flow reading glass and on the original placement glass. It is necessary to change the vertical position of the CIS depending on when the document is read. As described above, since the depth of focus of the CIS is extremely shallow, it is necessary to adjust the vertical position of the CIS in order to accurately read a document.

  In Patent Document 1, the CIS is guided by a rail-shaped guide plate, and the CIS is flowed and displaced up and down by an amount corresponding to the thickness of the reading glass, so that the CIS separation distance with respect to the original is made constant. However, in order to displace the CIS up and down, it is necessary to form a step in the guide plate, and this step causes the CIS movement operation to become unstable.

  Further, as in Patent Document 2, in order to put the end of the guide member into the concave portion of the glass, it is necessary to make the concave portion sufficiently deep. However, when such a concave portion is formed, the strength of the glass is remarkably lowered. If a heavy object such as a book is placed, the glass may be damaged. In addition, when the concave portion is shallow, the end portion of the guide member is difficult to enter the concave portion, and the effect that no step is formed between the end portion of the guide member and the upper surface of the original reading glass may not be achieved. .

  Accordingly, the present invention has been made in view of the above-described conventional problems, and an image reading apparatus that can smoothly move a CIS in a straight line and that does not cause jamming, and an image forming apparatus including the image reading apparatus. An object is to provide an apparatus.

  An image reading apparatus according to the present invention includes a first mode in which a document placed on the document placing glass is read by a contact image sensor moved along the lower surface of the document placing glass, and a document reading glass. An image reading device that switches and sets a second mode for reading a document conveyed along the upper surface of the document reading glass by the contact image sensor positioned on the lower surface side. A single glass that is divided into a region and a region of the original reading glass, and the contact image sensor or the movable body on which the contact image sensor is mounted, and the contact image sensor is moved. A sliding contact portion that is in sliding contact with the lower surface of the single glass, and the document reading glass from the document placement glass side in the second mode. A conveying unit that conveys the original glass to one end side of the single glass; and the original document that is provided on one end side of the single glass and that is conveyed to the one end side of the single glass from the original reading glass. A document guide portion that is scooped up, and an end portion of the document guide portion is disposed on the lower surface side of the document reading glass with respect to the upper surface of the document reading glass.

  In the present invention, one single glass is divided into a document placing glass and a document reading glass, and the sliding contact portion of the contact image sensor is in sliding contact with the lower surface of the single glass. The contact image sensor can be smoothly moved in a straight line, and the movement operation of the contact image sensor is stabilized.

  In addition, the document is transported from the document placement glass side to one end side of the single glass through the document reading glass, and the document is scooped up from the document reading glass by the document guide portion provided on one end side of the single glass. In the above, the end portion of the document guide portion is disposed on the lower surface side of the document reading glass with respect to the upper surface of the document reading glass. For this reason, the leading edge of the document is not caught by the edge of the document guide portion, and jamming does not occur.

  Therefore, the slidable contact portion of the contact image sensor can be slidably contacted with the lower surface of the single glass, and the contact image sensor can be smoothly moved linearly, and jamming does not occur. Thus, there is no need to provide a flow-reading glass or a guide plate on which a step is formed. Moreover, it is not necessary to form a recessed part in glass like patent document 2. FIG.

  In the image reading apparatus of the present invention, the sliding contact portion and the document guide portion come into contact with each other when the contact image sensor is brought closest to one end of the single glass in the moving range of the contact image sensor. do not do.

  In this case, even if the contact image sensor is closest to one end of the single glass, the sliding contact portion of the contact image sensor does not contact the document guide portion, and the movement operation of the contact image sensor is stabilized. Can do. The position of the contact image sensor when closest to one end of the single glass is, for example, the initial position of the contact image sensor.

  Furthermore, in the image reading apparatus of the present invention, a document position restricting portion with which the end of the document is brought into contact in the first mode is provided on the upper surface of the single glass.

  Such a document position restricting portion does not protrude to the lower surface side of the single glass, and thus does not come into contact with the sliding contact portion of the contact image sensor, and makes the movement operation of the contact image sensor unstable. There is no cause.

  In the image reading apparatus of the present invention, the end portion of the document guide portion is in contact with one end of the single glass.

  In this case, no gap is formed between the end of the document guide portion and one end of the single glass, and the document can be smoothly scooped up from the document reading glass by the document guide portion.

  Next, an image reading apparatus according to the present invention includes a first mode in which a document placed on the document placement glass is read by a contact image sensor moved along the lower surface of the document placement glass; An image reading apparatus for switching and setting a second mode for reading a document conveyed along the upper surface of the document reading glass by the contact image sensor positioned on the lower surface side of the reading glass, A single glass that is divided into a placement glass area and a document reading glass area, and the contact image sensor or a movable body on which the contact image sensor is mounted; A sliding contact portion that is in sliding contact with the original placing glass and the original reading glass is provided so as to be openable and closable. A conveying unit that conveys the original document from the document placement glass side to the one end side of the single glass through the document reading glass, and a document guide unit that is provided in the conveyance unit and scoops up the document from the document reading glass. Provided, when the transport unit is closed, the document guide unit is disposed on one end side of the single glass, and the end of the document guide unit is located above the upper surface of the document reading glass. Arranged on the lower surface side.

  In the present invention, one single glass is divided into a document placing glass and a document reading glass, and the sliding contact portion of the contact image sensor is in sliding contact with the lower surface of the single glass. The contact image sensor can be smoothly moved in a straight line, and the movement operation of the contact image sensor is stabilized.

  When the transport unit is closed, the document guide unit is disposed on one end of the single glass, and the end of the document guide unit is disposed on the lower surface side of the document reading glass with respect to the upper surface of the document reading glass. The document guide unit picks up the document from the document reading glass. For this reason, the leading edge of the document is not caught by the edge of the document guide portion, and jamming does not occur.

  In the image reading apparatus according to the present invention, the document guide unit is rotatably supported by an axis orthogonal to the document conveyance direction by the conveyance unit, and the document reading unit is read when the conveyance unit is closed. It abuts on a member below the upper surface of the glass and rotates to approach one end of the single glass.

  As described above, when the document guide unit is rotatably supported by an axis orthogonal to the document conveyance direction, the document guide unit rotates and approaches or separates from one end side of the single glass. Can be brought closer to one end of the single glass without being hooked to one end.

  Further, in the image reading apparatus according to the present invention, the document guide unit forms a part of the document transport path in the transport unit.

  In this case, the document guide unit not only scoops up from the document reading glass but also forms a part of the document transport path in the transport unit.

  The image reading apparatus according to the present invention further includes a sensor for detecting the rotational position of the document guide portion.

  Since the document guide unit contacts and rotates with a member below the upper surface of the document reading glass when the transport unit is closed, the rotation position of the document guide unit corresponds to the open / closed state of the transport unit. For this reason, it is possible to determine the open / closed state of the transport unit based on the rotation position of the document guide unit detected by the sensor.

  On the other hand, an image forming apparatus of the present invention includes the image reading apparatus of the present invention.

  Such an image forming apparatus of the present invention also has the same effects as the image reading apparatus of the present invention.

  In the present invention, one single glass is divided into a document placing glass and a document reading glass and used, and the sliding contact portion of the contact image sensor is brought into sliding contact with the lower surface of the single glass. The image sensor can be smoothly moved linearly, and the movement operation of the contact image sensor is stabilized.

  In addition, the document is transported from the document placement glass side to one end side of the single glass through the document reading glass, and the document is scooped up from the document reading glass by the document guide portion provided on one end side of the single glass. In the above, the end portion of the document guide portion is disposed on the lower surface side of the document reading glass with respect to the upper surface of the document reading glass. For this reason, the leading edge of the document is not caught by the edge of the document guide portion, and jamming does not occur.

  Therefore, the slidable contact portion of the contact image sensor can be slidably contacted with the lower surface of the single glass, and the contact image sensor can be smoothly moved linearly, and jamming does not occur. Thus, there is no need to provide a flow-reading glass or a guide plate on which a step is formed. Moreover, it is not necessary to form a recessed part in glass like patent document 2. FIG.

1 is a cross-sectional view showing an image forming apparatus provided with an embodiment of an image reading apparatus of the present invention. It is sectional drawing which shows the image reading apparatus of FIG. 1 seeing from a side. It is a top view which shows the reading part of the image reading apparatus of FIG. It is sectional drawing which expands and shows a contact type image sensor (CIS). FIG. 3 is an enlarged cross-sectional view illustrating a document guide portion provided on the front end side of a single glass of the image reading apparatus. It is sectional drawing which expands and shows the comparative example of a document guide part. (A), (b) is the top view and side view which show the internal structure of a reading part. It is sectional drawing which expands and shows a close_contact | adherence image sensor (CIS), a sliding contact part, and single glass. It is a front view which shows the state which pressed each sliding contact part of the both ends of a contact | adherence type image sensor (CIS) on the lower surface of the single glass. It is sectional drawing which shows the image reading apparatus of 2nd Embodiment seeing from the side. It is a top view which shows the reading part of the image reading apparatus of FIG. FIG. 11 is a cross-sectional view illustrating a partially enlarged state in which a document conveyance unit of the image reading apparatus in FIG. 10 is opened. FIG. 11 is a partially enlarged cross-sectional view illustrating a state in which a document conveyance unit of the image reading apparatus in FIG. 10 is closed. It is sectional drawing which expands and shows a part of image reader of 3rd Embodiment seeing from the side. FIG. 15 is a cross-sectional view taken along line AA in FIG. 14 and omitting the upper guide plate in FIG. 14. FIG. 15 is a cross-sectional view illustrating a state in which a document conveyance unit of the image reading apparatus in FIG. 14 is opened.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a sectional view showing an image forming apparatus provided with a first embodiment of an image reading apparatus of the present invention. The image data handled in the image forming apparatus 1 corresponds to a color image using each color of black (K), cyan (C), magenta (M), yellow (Y), or a single color (for example, black). This corresponds to the monochrome image used. For this reason, four each of the developing device 12, the photosensitive drum 13, the drum cleaning device 14, and the charger 15 are provided in order to form four types of toner images corresponding to the respective colors, and black, cyan, Four image stations Pa, Pb, Pc, and Pd are configured in association with magenta and yellow.

  In each of the image stations Pa, Pb, Pc, and Pd, after the residual toner on the surface of the photosensitive drum 13 is removed and collected by the drum cleaning device 14, the surface of the photosensitive drum 13 is set to a predetermined potential by the charger 15. It is charged uniformly, the surface of the photosensitive drum 13 is exposed by the optical scanning device 11, an electrostatic latent image is formed on the surface, and the electrostatic latent image on the surface of the photosensitive drum 13 is developed by the developing device 12, A toner image is formed on the surface of the photosensitive drum 13. As a result, a toner image of each color is formed on the surface of each photosensitive drum 13.

  Subsequently, while the intermediate transfer belt 21 is moved in the direction of the arrow C, the residual toner on the intermediate transfer belt 21 is removed and collected by the belt cleaning device 25, and then each color toner image is transferred onto the surface of each photosensitive drum 13. The toner images are sequentially transferred onto the belt 21 and overlapped to form a color toner image on the intermediate transfer belt 21.

  A nip area is formed between the intermediate transfer belt 21 and the transfer roller 26a of the secondary transfer device 26. The intermediate transfer is performed while the recording paper conveyed through the paper conveyance path R1 is sandwiched and conveyed in the nip area. The color toner image on the surface of the belt 21 is transferred onto the recording paper. Then, the recording paper is sandwiched between the heating roller 31 and the pressure roller 32 of the fixing device 17 and heated and pressed to fix the color toner image on the recording paper.

  On the other hand, the recording paper is pulled out from the paper feed tray 18 by the pickup roller 33, conveyed through the S-shaped paper conveyance path R 1, passes through the secondary transfer device 26 and the fixing device 17, and passes through the paper discharge roller 36. Then, it is carried out to the paper discharge tray 39. In this paper conveyance path R1, after the recording paper is temporarily stopped and the leading edges of the recording paper are aligned, recording is performed in accordance with the transfer timing of the color toner image in the nip area between the intermediate transfer belt 21 and the transfer roller 26a. A set of registration rollers 34 for starting the conveyance of the sheet, a plurality of sets of conveyance rollers 35 for urging the conveyance of the recording sheet, a set of discharge rollers 36, and the like are arranged.

  Further, when printing not only on the front side of the recording paper but also on the back side, the recording paper is conveyed in the reverse direction from each discharge roller 36 to the reverse path Rr, and the recording paper is turned upside down. The image is guided again to each registration roller 34, and the image is recorded and fixed on the back surface of the recording paper, similarly to the front surface of the recording paper, and the recording paper is carried out to the paper discharge tray 39.

  Next, a schematic configuration of the image reading apparatus 2 according to the first embodiment mounted on the upper part of the main body of the image forming apparatus 1 in FIG. 1 will be described. FIG. 2 is a cross-sectional view showing the image reading device 2 as viewed from the side. FIG. 3 is a plan view showing the reading unit 41 of the image reading device 2.

  As shown in FIG. 2, the image reading apparatus 2 includes a lower reading unit 41 and an upper document conveying unit 61. The document conveyance unit 61 is pivotally supported on the back side of the reading unit 41 by a hinge (not shown) and opened and closed by moving the front portion up and down. When the document transport unit 61 is opened, the document placement glass 43 and the document reading glass 42 of the reading unit 41 are opened.

  As shown in FIGS. 2 and 3, in the reading unit 41, a single glass G is provided in the upper opening of the housing 44, and an edge plate is provided between each side plate 44 a of the housing 44 and the four sides of the single glass G. 44b. The single glass G is a single transparent glass plate having a uniform thickness, and a rectangular frame member 45 is provided on the left end side (the front end side of the single glass G). The opposite two sides of the rectangular frame member 45 are a document position restricting portion 46 and a document guide portion 47. Both end portions 45a of the rectangular frame member 45 are disposed outside the single glass G, the document position restricting portion 46 is disposed on the upper surface of the single glass G, and the document guide portion 47 is disposed outside the front end of the single glass G. Has been. For this reason, the whole lower surface of the single glass G is a smooth flat surface.

  The document placing glass 43 and the document reading glass 42 correspond to two regions obtained by dividing the single glass G by the document position restricting unit 46, and share the transparent single glass G. The area of the document placing glass 43 is an area from the rear end 46a of the document position restricting portion 46 to the rear end (right end in FIG. 2) of the single glass G, on which the document is placed. . The area of the original reading glass 42 is an area from the front end of the original position restricting section 46 to the front end of the single glass G (the left end in FIG. 2), on which the original is conveyed and passes.

  As shown in FIG. 2, a contact image sensor (CIS (Contact Image Sensor)) 48 is disposed below the document placing glass 43 and the document reading glass 42, and is positioned by a position sensor 49 below the document reading glass 42. When the moving frame 71 (shown in FIGS. 7A and 7B) carrying the CIS 48 is detected, the CIS 48 is at the initial position. The CIS 48 reads the document placed on the document placement glass 43 while being moved in the sub-scanning direction X below the document placement glass 43 by the moving unit MU (first mode), and is constant from the initial position. The document is positioned at a reading position below the document reading glass 42 separated by a distance, and the document passing on the document reading glass 42 is read (second mode).

  4 is an enlarged cross-sectional view of the CIS 48. As shown in FIG. As shown in FIG. 4, the CIS 48 includes a pair of LED arrays 51 that illuminate a document through a document placement glass 43 and a document reading glass 42, a SELFOC (registered trademark) lens array 52 that collects reflected light from the document, And a line sensor 53 that photoelectrically converts reflected light from the document and outputs an analog image signal.

  In the first mode, the document conveying unit 61 is opened, the document is placed on the document placement glass 43, the leading end of the document is brought into contact with the rear end 46a of the document position restricting unit 46, the document is positioned, The document conveying unit 61 is closed. The CIS 48 stands by at a reading position below the document reading glass 42 and is moved from the reading position to the position below the document placing glass 43 by the moving unit MU, and further the document leading edge (the rear end 46a of the document position regulating unit 46). Is moved in the sub-scanning direction X at a constant speed by a distance corresponding to the document size. During this movement, each LED array 51 illuminates the original on the original placement glass 43, and reflected light from the original is condensed on the line sensor 53 by the SELFOC lens array 52. The line sensor 53 repeatedly scans the document in the main scanning direction Y, and outputs an analog image signal of one main scanning line each time to read the document.

  In the second mode, the CIS 48 is positioned at a reading position below the document reading glass 42. In this state, the original is placed on the original tray 62 of the original conveying unit 61 and set, and the original conveying by the original conveying unit 61 is started. In the document transport unit 61, the document on the document tray 62 is pulled out by the pickup roller 63, and the document is transported to the document reading glass 42 through the document transport path 64. At this time, the leading edge of the document is guided by the inclined guide surface 46b of the document position restricting section 46 and guided to the upper surface of the document reading glass 42, and the document slides on the upper surface of the document reading glass 42, and the document guide section. The original is scooped up from the upper surface of the original reading glass 42 by the inclined surface 47 a of 47. Further, the original is conveyed through the original conveying path 64 and is discharged from the discharge roller 66 to the discharge tray 67. In the document transport path 64, a registration roller 68 that transports the document after aligning the leading ends thereof, a transport roller 69 that transports the document, and the like are arranged.

  In the CIS 48, each LED array 51 illuminates a document passing over the document reading glass 42, the reflected light from the document is condensed on the line sensor 53 by the SELFOC lens array 52, and the document is repeated by the line sensor 53. Scanning is performed in the main scanning direction Y, and an analog image signal of one main scanning line is output from the line sensor 53 at each scanning.

  As described above, in both the first and second modes, the document is read by the CIS 48 and an analog image signal is output from the CIS 48. This analog image signal is A / D converted into a digital image signal, subjected to various image processing, and then sent to the optical scanning device 11 of the image forming apparatus 1 where an original is recorded on a recording sheet. The recording paper is output as a copy original.

  Here, as is apparent from FIG. 2, the document transport path 64 extends from the document placement glass 43 side through the document reading glass 42 to the tip of the single glass G, and is further curved upward by approximately 180 °. The paper reaches the paper discharge tray 67. Accordingly, the document is conveyed from the document placing glass 43 side to the front end of the single glass G through the document reading glass 42, further inverted 180 ° upward, and discharged to the sheet discharge tray 67.

  Further, as shown in an enlarged view in FIG. 5, the document guide portion 47 provided on the front end side of the single glass G has only an inclined surface 47a protruding above the upper surface of the document reading glass 42, and its end portion 47b. Is disposed below the upper surface of the document reading glass 42 (on the lower surface side of the document reading glass 42). For this reason, when the document is conveyed in the arrow direction J from the document placement glass 43 side to the leading edge of the single glass G via the document reading glass 42, the leading edge of the document is inclined surface 47a of the document guide portion 47. The original is quickly picked up from the upper surface of the original reading glass 42 by the inclined surface 47a. Therefore, the leading edge of the document is not caught by the end portion 47b of the document guide portion 47, and no jam occurs.

  If the original is conveyed in the reverse direction K from the front end side to the rear end side of the original reading glass 42 as shown in FIG. 6, the front end of the original is caught by the end portion 46c of the original position restricting portion 46, and jammed. Will occur.

  In the present invention, as shown in FIG. 5, an original is conveyed from the original placement glass 43 side to the front end of the single glass G via the original reading glass 42 and then the end of the original guide 47 Since 47b is arranged below the upper surface of the document reading glass 42, the leading edge of the document is not caught by the end portion 47b of the document guide portion 47, and jamming does not occur.

  Next, the moving unit MU for moving the CIS 48 in the reading unit 41 of the image reading apparatus 2 of the first embodiment will be described in detail. 7A and 7B are a plan view and a side view showing the internal structure of the reading unit 41 in a state where the single glass G and the edge plate 44b of the housing 44 are removed.

  As shown in FIGS. 7A and 7B, in the moving unit MU, the CIS 48 is mounted on a moving frame 71 extending in the main scanning direction Y. Each holder 72 is fixed to both ends of the CIS 48, and each coil spring 74 is fitted into each pin 73 protruding from both ends of the moving frame 71, and each pin 73 is connected to each holder at both ends of the CIS 48. The respective holders 72 are placed on the respective coil springs 74 through the holes 72 a of 72. Each pin 73 supports the CIS 48 with respect to the moving frame 71 so as not to shift in the sub-scanning direction X and the main scanning direction Y, and supports the CIS 48 so as to be movable in the vertical direction. Each coil spring 74 receives and elastically supports the CIS 48 with the bottom surface of the CIS 48 separated from the moving frame 71. When the CIS 48 descends, each coil spring 74 is shortened, and the CIS 48 is biased upward by each coil spring 74.

  In addition, each contact portion 77 made of POM (polyoxymethylene) or the like is provided at the upper end of each holder 72. As shown in the cross-sectional views of FIG. 7B and FIG. 8, the sliding contact portions 77 are provided so as to overlap the outer ends of both ends of the CIS 48 and protrude upward from the upper surface of the CIS 48 to the same height.

  Further, a columnar shaft 75 is fixed to the front and rear side plates 44 a of the housing 44 so as to extend in parallel with the sub-scanning direction X. A guide member 76 is fixed to the bottom surface of the moving frame 71, and a shaft 75 is fitted into a semi-cylindrical recess facing downward of the guide member 76, and the moving frame 71 is inserted into the shaft 75 via the guide member 76. The moving frame 71 is supported by the shaft 75 so as to be movable in the sub-scanning direction X.

  In addition, a pair of shafts 81 and 82 that are spaced apart from each other in the sub-scanning direction X are vertically projected on the bottom plate 44 d of the housing 44, and the small pulleys 83 and 84 rotate at the upper ends of the shafts 81 and 82. An endless driven belt 85 is bridged between the small pulleys 83 and 84. A guide member 76 on the bottom surface of the moving frame 71 is connected to the outer peripheral surface of the driven belt 85.

  A large pulley 86 is concentrically fixed to the small pulley 84 of the one shaft 82 so that the small pulley 84 and the large pulley 86 rotate together. The motor 87 is fixed to the bottom plate 44 d of the housing 44 in the vicinity of one shaft 82. A drive pulley 88 is fixed to the output shaft of the motor 87, and an endless drive belt 89 is bridged between the drive pulley 88 and the large pulley 86.

  As shown in FIGS. 8 and 9, the sliding contact portions 77 of the holders 72 at both ends of the CIS 48 are pressed against the lower surface of the single glass G. For this reason, the coil springs 74 are sandwiched between the holders 72 and the moving frames 71 at both ends of the CIS 48, and the coil springs 74 are shortened. One glass G is pressed against the lower surface. Since the protruding heights of the sliding contact portions 77 of the holders 72 with respect to the upper surface of the CIS 48 are the same, the CIS 48 is parallel to the lower surface of the single glass G.

  When the motor 87 is driven and the drive pulley 88 is rotated in a state where the sliding contact portion 77 of each holder 72 is pressed against the lower surface of the single glass G, the rotation of the drive pulley 88 is caused to rotate via the drive belt 89. The small pulley 84 rotates together with the large pulley 86 and the rotation of the small pulley 84 is transmitted to the small pulley 83 via the driven belt 85, and the small pulley 83 rotates. Then, the driven belt 85 moves around, the guide member 76 connected to the driven belt 85 slides on the shaft 75, and the moving frame 71 moves in the sub scanning direction X. Further, since the rotation direction of the output shaft of the motor 87 corresponds to the movement direction of the moving frame 71, and the rotation angle of the output shaft of the motor 87 corresponds to the movement distance of the moving frame 71, the rotation direction of the output shaft of the motor 87. By controlling the rotation angle, the moving direction and moving distance of the moving frame 71 and the CIS 48 can be controlled.

  Further, a position sensor 49 is provided near one end of the one side plate 44 a of the housing 44. The position sensor 49 is, for example, a light emitting element and a light receiving element arranged to face each other, and detects the guide piece 71a of the moving frame 71 that has entered between the light emitting element and the light receiving element.

  Here, when the output shaft of the motor 87 is rotated in one direction to move the moving frame 71 and the CIS 48 to below the original reading glass 42, the guide piece 71a of the moving frame 71 causes the light emitting element and the light receiving element of the position sensor 49 to move. And the guide piece 71a is detected by the position sensor 49. In response to the detection output of the position sensor 49, the motor 87 is stopped and the CIS 48 is positioned at the initial position below the original reading glass 42. Subsequently, the motor 87 is rotated in the reverse direction by a fixed rotation angle, and the CIS 48 is moved. Is moved by a certain distance in a direction away from the position sensor 49, and the CIS 48 is positioned at a reading position below the original reading glass 42. At this time, the initial position of the CIS 48 and the sliding contact of each holder 72 are prevented so that the sliding contact portions 77 of the holders 72 at both ends of the moving frame 71 do not contact the bottom surface of the document guide portion 47 or the tip of the single glass G. The width of the portion 77 in the sub-scanning direction X is set.

  In the second mode, a document passing over the document reading glass 42 is read by the CIS 48 with the CIS 48 positioned at a reading position below the document reading glass 42.

  In the first mode, the rotation direction and the rotation angle of the output shaft of the motor 87 are controlled to move the moving frame 71 and the CIS 48 below the document placing glass 43, and subsequently the moving frame 71 and the CIS 48 are moved to the front end of the document. The document is moved in the sub-scanning direction X at a constant speed by a distance corresponding to the document size from the (position of the rear end 46a of the document position restricting section 46), and the document placed on the document placement glass 43 is read by the CIS 48.

  Further, the lower surface of the document position regulating unit 46 is white, and the lower surface of the document position regulating unit 46 can be read by the CIS 48 to generate shading correction data. In this case, after the CIS 48 is once positioned at the initial position, the rotation direction and the rotation angle of the output shaft of the motor 87 are controlled to position the CIS 48 below the document position restricting portion 46, and the lower surface of the document position restricting portion 46. Is read by the CIS 48, the output of the CIS 48 is sampled, and shading correction data is generated from the sampled output.

  When moving the moving frame 71 and the CIS 48, the sliding contact portion 77 of each holder 72 slides on the lower surface of the single glass G, but the entire lower surface of the single glass G is a smooth flat surface. The moving frame 71 and the CIS 48 are smoothly translated relative to the lower surface of the single glass G, and the moving operation of the CIS 48 is not unstable, and the CIS 48 with an extremely shallow depth of focus (about 0.4 mm) is used. The original on the single glass G (the original reading glass 42 and the original placing glass 43) can be read accurately.

  Even if the CIS 48 is positioned at the initial position, the sliding contact portion 77 of each holder 72 does not come into contact with the bottom surface of the document guide portion 47 or the tip of the single glass G. This also stabilizes the moving operation of the CIS 48. .

  That is, in the image reading apparatus 2 of the first embodiment, the CIS 48 can be smoothly moved linearly by sliding the sliding contact portions 77 of the holders 72 of the CIS 48 against the lower surface of the single glass G, and There is no occurrence of jamming, and there is no need to provide a flow-reading glass or a guide plate on which a step is formed as in Patent Document 1. Moreover, it is not necessary to form a recessed part in glass like patent document 2. FIG.

  Next, an image reading apparatus 2A according to the second embodiment will be described. FIG. 10 is a cross-sectional view showing the image reading apparatus 2A of the second embodiment as viewed from the side. FIG. 11 is a plan view showing the reading unit 41 of the image reading apparatus 2A of the second embodiment. 10 and 11, the same reference numerals are given to the portions that perform the same functions as those in FIGS. 2 and 3.

  The image reading apparatus 2A according to the second embodiment is different from the image reading apparatus 2 according to the first embodiment in that a document position restricting unit 101 and a document guide unit 102 are provided instead of the document position restricting unit 46.

  The document position restricting unit 101 is provided on the surface of the single glass G of the reading unit 41, and divides the surface of the single glass G into a region of the document placement glass 43 and a region of the document reading glass 42. The area of the document placement glass 43 is an area from the rear end 101a of the document position restricting portion 101 to the rear end of the single glass G (the right end in FIGS. 10 and 11), on which the document is placed. Placed. Further, the area of the original reading glass 42 is a rectangular area surrounded by the three inner sides of the original position restricting portion 101 and the front end of the single glass G (the left end in FIGS. 10 and 11) when viewed in plan. is there.

  The document position restricting unit 101 has an inclined guide surface 101b that guides the leading edge of the document to the upper surface of the document reading glass 42 in the second mode. Further, the lower surface of the document position regulating unit 101 is white, and the lower surface of the document position regulating unit 101 can be read by the CIS 48 to generate shading correction data.

  The document guide unit 102 is provided in the document transport unit 61. The document guide unit 102 is longer than the document reading glass 42 and the document placement glass 43 in the main scanning direction Y, and both ends of the document guide unit 102 are opposed to the body casing or the frame of the document transport unit 61. It is fixed and supported on the wall. The document guide unit 102 has an inclined surface 102 a and a lower surface 102 b, and the inclined surface 102 a is connected to the guide wall 64 a of the document conveyance path 64 to form a part of the document conveyance path 64.

  As described above, the document position restricting unit 101 and the document guide unit 102 are provided separately for the reading unit 41 and the document conveying unit 61.

  Here, the document transport unit 61 is pivotally supported on one side of the reading unit 41 and is opened and closed by moving the front portion thereof up and down, so that it is also opened and closed with respect to the document placing glass 43 and the document reading glass 42. The Therefore, as shown in FIG. 12, when the document conveying portion 61 is opened, the document guide portion 102 is separated from the document reading glass 42 together with the document conveying portion 61. Further, when the document conveying portion 61 is closed, the document guide portion 102 is disposed near the front end of the document reading glass 42 as shown in FIG.

  FIG. 13 is an enlarged cross-sectional view showing the vicinity of the document guide unit 102 and the document reading glass 42 when the document conveying unit 61 is closed. As shown in FIG. 13, in the vicinity of the front end of the document reading glass 42, a contact surface 44 c is provided in which the surface of the border plate 44 b that borders the four sides of the single glass G is lower than the surface of the document reading glass 42. A step is formed between the surface of the original reading glass 42 and the contact surface 44c. When the document transport unit 61 is closed, the lower surface 102b of the document guide unit 102 contacts the contact surface 44c, and the tip 102c of the document guide 102 is the tip of the document reading glass 42 (the tip of the single glass G) 42a. The leading end 102c of the document guide portion 102 is disposed below the upper surface of the document reading glass 42.

  In the image reading apparatus 2A of the second embodiment having such a configuration, in the first mode, as in the image reading apparatus 2 of the first embodiment, the document transport unit 61 is opened, and the document is loaded on the document. Positioned on the glass plate 43, the document conveying section 61 is closed. In this state, the document on the document placement glass 43 is read by the CIS 48 while the moving unit MU moves the CIS 48 below the document placement glass 43.

  In the second mode, the CIS 48 is positioned at the reading position below the document reading glass 42, and the document is set on the document tray 62 with the document transport unit 61 closed. At this time, as shown in FIG. 13, the leading end portion 102 c of the document guide portion 102 is disposed close to the leading end 42 a of the document reading glass 42 and below the upper surface of the document reading glass 42.

  In the document transport unit 61, the document on the document tray 62 is pulled out by the pickup roller 63, and the document is transported to the document reading glass 42 through the document transport path 64 (in the arrow direction J). The guide 101 is guided by the inclined guide surface 101 b of 101 and is guided between the document reading glass 42 and the upper guide plate 114, and the document slides on the upper surface of the document reading glass 42. Subsequently, the original is scooped up from the upper surface of the original reading glass 42 by the inclined surface 102a of the original guide portion 102, and further, the original is introduced into the original conveyance path 64 by the inclined surface 102a of the original guide portion 102, and the original is conveyed. The document is conveyed through the path 64, and the document is discharged from the discharge roller 66 to the discharge tray 67.

  As described above, in the image reading apparatus 2A according to the second embodiment, the document guide unit 102 is provided on the document conveyance unit 61 side, and when the document conveyance unit 61 is closed, the leading end 102c of the document guide unit 102 is the document reading glass. It is arranged close to the front end 42a of 42 and below the upper surface of the original reading glass 42. Therefore, the front end of the original conveyed from the side of the original placement glass 43 toward the front end 42 a of the original reading glass 42 is not caught on the front end 102 c of the original guide section 102, and the original guide section 102 is inclined. The original is scooped up by the surface 102a, and jamming does not occur.

  Next, the image reading device 2B of the third embodiment will be described. FIG. 14 is an enlarged cross-sectional view of a part of the image reading apparatus 2B according to the third embodiment as viewed from the side. 15 is a cross-sectional view taken along line AA in FIG. 14 and omitting the upper guide plate 114 in FIG. In FIGS. 14 and 15, the same reference numerals are given to portions that perform the same functions as those in FIGS. 10 to 13.

  In the image reading apparatus 2B of the third embodiment, instead of the document guide unit 102, a document guide unit 111 that is rotatably supported and an optical sensor 112 that detects the rotational position of the document guide unit 111 are provided. However, this is different from the image reading apparatus 2A of the second embodiment.

  The document guide unit 111 is provided in the document transport unit 61, is longer than the document reading glass 42 and the document placement glass 43 in the main scanning direction Y, and is rotatable by a shaft 113 orthogonal to the document transport direction by the document transport unit 61. And is urged in the arrow direction E by an urging member (not shown) such as a kick spring.

  Further, a detected piece 111 d is projected from the center of the document guide portion 111 in the main scanning direction Y, and a notch slit 64 b is formed at the center of the guide wall 64 a of the document transport path 64, and as the document guide portion 111 rotates. The detected piece 111d that moves in such a manner passes through the notch slit 64b of the guide wall 64a.

  In the optical sensor 112, for example, a light-emitting element and a light-receiving element are spaced apart from each other, and the detected piece 111d of the document guide unit 111 passes between the elements.

  Here, as shown in FIG. 16, when the document transport unit 61 is opened, the document guide unit 111 is separated from the document reading glass 42 together with the document transport unit 61, and the lower surface 111c of the document guide unit 111 is separated from the contact surface 44c. To do. At this time, the document guide unit 111 rotates about the shaft 113 in the arrow direction E by the urging force of the urging member, the leading end portion 111 e of the document guide unit 111 moves in the arrow direction F, and one end of the document guide unit 111 is moved. The portion 111a contacts the part 61a of the casing of the document conveying portion 61, and the document guide portion 111 is held at a predetermined rotational position. Further, the detected piece 111d of the document guide portion 111 is shifted from between the light emitting element and the light receiving element of the optical sensor 112, and the detected piece 111d is not detected by the optical sensor 112.

  Next, in the process in which the document conveying unit 61 is closed, the document guide unit 111 is held at a predetermined rotational position by the urging force of the urging member, so that the leading end 111e of the document guide unit 111 is moved in the arrow direction F. Therefore, the leading end portion 111e of the document guide portion 111 passes through a position away from the leading end 42a of the document reading glass 42, and the leading end portion 111e of the document guide portion 111 is caught by the leading end 42a of the document reading glass 42. Absent. 14 and 15, when the document conveying portion 61 is closed, the lower surface 111c of the document guide portion 111 contacts the contact surface 44c, and the document guide portion 111 is centered on the shaft 113 in the direction indicated by the arrow E. , The leading end portion 111e of the document guide portion 111 approaches the leading end 42a of the document reading glass 42, and the leading end portion 111e of the document guide portion 111 is disposed below the upper surface of the document reading glass 42. Is done. Further, the inclined surface 111 b of the document guide portion 111 is connected to the guide wall 64 a of the document transport path 64 to form a part of the document transport path 64. Further, the detected piece 111d of the document guide portion 111 moves between the light emitting element and the light receiving element of the optical sensor 112, and the detected piece 111d is detected by the optical sensor 112.

  In the image reading apparatus 2B of the third embodiment having such a configuration, in the first mode, the document is placed on the document placement glass 43, and the document transport unit 61 is closed. While the CIS 48 is moved below the document placement glass 43 by the MU, the document on the document placement glass 43 is read by the CIS 48.

  In the second mode, the document conveying portion 61 is closed, and the leading end portion 111e of the document guide portion 111 approaches the leading end 42a of the document reading glass 42 as shown in FIGS. It is arranged below the upper surface. In this state, the document on the document tray 62 is pulled out by the pickup roller 63, and the document is conveyed to the document reading glass 42 through the document conveyance path 64. Then, the leading edge of the document is guided by the inclined guide surface 101 b of the document position regulating unit 101 and guided to the upper surface of the document reading glass 42, and the document slides on the upper surface of the document reading glass 42, and the document guide unit 111. The original is scooped up from the upper surface of the original reading glass 42 by the inclined surface 111b, and the original is introduced into the original conveying path 64 by the inclined surface 111b of the original guide 111, and the original is conveyed through the original conveying path 64. The document is discharged from the discharge roller 66 to the discharge tray 67. Therefore, the front end of the original is not caught by the front end portion 111e of the original guide portion 111, and the original is scooped up by the inclined surface 111b of the original guide portion 111, so that the jam does not occur.

  Further, when the document conveying section 61 is opened as shown in FIG. 16, the detected piece 111d of the document guide section 111 is not detected by the optical sensor 112, and the document conveying section 61 is detected as shown in FIGS. When closed, the optical sensor 112 detects the detected piece 111d of the document guide unit 111, so that the open / close state of the document transport unit 61 can be determined based on the detection output of the optical sensor 112, and the document transport unit By starting the first and second modes in response to the determination of the closed state of 61, it is possible to prevent a failure in the original reading operation.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. It is understood.

DESCRIPTION OF SYMBOLS 1 Image forming device 2, 2A, 2B Image reading device 11 Optical scanning device 12 Developing device 13 Photosensitive drum 14 Drum cleaning device 15 Charger 17 Fixing device 21 Intermediate transfer belt 26 Secondary transfer device 41 Reading unit 42 Document reading glass 43 Document placement glass 46, 101 Document position restriction units 47, 102, 111 Document guide unit 112 Optical sensor 48 Contact image sensor (CIS (Contact Image Sensor))
61 Document transport section (transport section)
77 Sliding contact part G Single glass MU Moving unit

Claims (10)

A first mode in which a document placed on the document placement glass is read by a contact image sensor moved along the lower surface of the document placement glass, and the contact positioned on the lower surface side of the document reading glass. An image reading device that switches and sets a second mode for reading a document conveyed along the upper surface of the document reading glass by a mold image sensor,
A single glass used by dividing into an area of the document placement glass and an area of the document reading glass;
Provided in the contact image sensor or a moving body equipped with the contact image sensor, and a sliding contact portion that is in sliding contact with the lower surface of the single glass;
A transport unit that transports the document from the document placement glass side to the one end side of the single glass through the document reading glass in the second mode;
A document guide provided on one end of the single glass, and scooping up the document conveyed to the one end of the single glass from the document reading glass;
An image reading apparatus, wherein an end portion of the document guide portion is disposed on a lower surface side of the document reading glass with respect to an upper surface of the document reading glass. The image reading apparatus according to claim 1,
An image reading apparatus characterized in that the sliding contact portion and the document guide portion do not come into contact with each other when the contact image sensor is brought closest to one end of the single glass in the moving range of the contact image sensor. The image reading device according to claim 1 or 2,
An image reading apparatus characterized in that an original position restricting portion against which an end of the original comes into contact in the first mode is provided on the upper surface of the single glass. The image reading apparatus according to any one of claims 1 to 3,
An image reading apparatus, wherein an end portion of the document guide portion is brought into contact with one end of the single glass.   An image forming apparatus comprising the image reading device according to claim 1. A first mode in which a document placed on the document placement glass is read by a contact image sensor moved along the lower surface of the document placement glass, and the contact positioned on the lower surface side of the document reading glass. An image reading device that switches and sets a second mode for reading a document conveyed along the upper surface of the document reading glass by a mold image sensor,
A single glass used by dividing into an area of the document placement glass and an area of the document reading glass;
Provided in the contact image sensor or a moving body equipped with the contact image sensor, and a sliding contact portion that is in sliding contact with the lower surface of the single glass;
The original placing glass and the original reading glass are provided so as to be openable and closable, and are closed in the second mode. The original is placed on the single glass from the original placing glass side through the original reading glass. A transport section for transporting to one end side;
A document guide unit provided in the transport unit and scooping up the document from the document reading glass;
When the conveying unit is closed, the document guide unit is disposed on one end side of the single glass, and the end of the document guide unit is on the lower surface side of the document reading glass than the upper surface of the document reading glass. An image reading apparatus, wherein The image reading device according to claim 6,
The document guide unit is rotatably supported by an axis orthogonal to the document conveyance direction by the conveyance unit, and abuts against a member below the upper surface of the document reading glass when the conveyance unit is closed. An image reading apparatus that rotates and approaches one end of the single glass. The image reading device according to claim 6 or 7,
The image reading apparatus, wherein the document guide unit forms a part of a document transport path in the transport unit. The image reading apparatus according to claim 7, comprising:
An image reading apparatus comprising a sensor for detecting a rotational position of the document guide section.   An image forming apparatus comprising the image reading device according to claim 6.

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