JP5783713B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus that reads image information of a document and an image forming apparatus including the image reading apparatus.

  2. Description of the Related Art Conventionally, there has been known an image reading apparatus equipped with an original document feeder (Auto Document Feeder) that feeds a set original to an image reading position on a platen glass, reads image information at the image reading position, and then discharges the original. Yes.

  The image reading apparatus moves the image reading unit below the image reading position, then emits light from the lamp unit, and transports the document along the platen glass at the image reading position to scan the document. Then, the reflected light is detected by the image reading means to read the image information of the document. Therefore, in order to prevent the occurrence of image blur and fog caused by the floating of the conveyed document, the image reading device regulates the lifting of the document at the image reading position when detecting the reflected light and reading the image information. There is a need to.

  In response to this, an image reading apparatus is disclosed that guides an original on a platen glass while suppressing the original with a roller, and restricts the lifting of the original with a reading guide portion disposed opposite to the platen glass (for example, Patent Document 1). The reading guide unit of the image reading apparatus includes a platen roller that guides a document along the platen glass, and a regulation plate that causes the document guided on the platen glass to closely contact the platen glass.

JP 2003-189069 A

  However, in the image reading device disclosed in Patent Document 1, since the restriction plate of the reading guide portion disposed to face the platen glass is formed in an elongated shape in the longitudinal direction, the restriction plate easily causes warpage in the longitudinal direction. . In addition, the regulating plate may bend and vibrate due to vibration during document conveyance. For this reason, the distance between the platen glass and the regulating plate is not stable. For example, when a non-standard-size document or a perforated document is read, fogging or white spots may occur due to a change in the amount of light.

  In order to cope with this, it is conceivable to increase the strength of the regulating plate against warping or bending vibration by increasing the length (lateral width) of the regulating plate in the short direction. However, if the length of the regulation plate in the short direction is increased, the platen glass needs to be increased in accordance with this, so that there is a problem that the entire apparatus becomes larger.

  SUMMARY OF THE INVENTION Accordingly, the present invention provides an image reading apparatus capable of suitably suppressing the occurrence of warping or vibration of the reading guide portion without increasing the size of the reading guide portion that regulates the lifting of the document, and an image provided with the image reading device. An object is to provide a forming apparatus.

The present invention provides a feeding roller that feeds a document to a platen, an image reading unit that reads an image of a document fed from the feeding roller through the platen, and the image reading unit through the platen. and arranged opposite, with a reading guide section for guiding the document fed, and a discharge portion for discharging a document image is read out of the machine by the image reading means, the reading guide section, feeding the paper a first row La that the fed original document to guide along the platen from the roller, a second roller disposed downstream of the first roller, the first roller and the rotational axis of the second roller And a guide plate that guides a document conveyed along the platen, and supports the first roller in a swingable manner about the rotation shaft of the feed roller, and the first roller is supported by the platen. For A first swinging arm that biases the second roller, and a second swinging member that swingably supports the second roller about the rotation axis of the first roller and biases the second roller toward the platen. A movable arm, and the second swing arm has a butting portion that holds the gap between the first roller and the second roller and the platen at a constant distance by abutting against the platen, The guide plate is disposed between the first roller and the second roller , and is disposed on both ends of the rotation shafts of the first roller and the second roller and on the rotation shaft located between the both ends. They are respectively supported at least one place, an image reading apparatus, characterized in that.

  The present invention suppresses warping and vibration of the restriction plate and improves the quality of the formed image by supporting a restriction plate that closely attaches the document to the platen glass at a plurality of positions of the roller portion that guides the document. Can do.

1 is a cross-sectional view illustrating an image reading apparatus according to an embodiment of the present invention. It is a perspective view which shows the reading guide part of the image reading apparatus shown in FIG. FIG. 3 is an exploded view of the reading guide portion shown in FIG. 2. It is a side view of the reading guide part located above platen glass. It is sectional drawing of the reading guide part located above platen glass. It is sectional drawing of the reading guide part located above platen glass.

  Hereinafter, an image reading apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings. First, the overall configuration of the image reading apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an image reading apparatus 1 according to an embodiment of the present invention.

  As shown in FIG. 1, the image reading apparatus 1 includes a document feeding unit 2 that feeds a sheet-like document P, and a platen glass 161 that serves as a platen on which the document P fed by the document feeding unit 2 is placed. . In addition, the image reading apparatus 1 includes a reader unit 150 serving as an image reading unit that reads an image of the document P placed on the platen glass 161, a placement table glass 3 on which the document P is fixedly placed, A pressure plate 15 that presses the document P placed on the table glass 3.

  The document feeder 2 includes a document tray 4 on which documents P are stacked, a feeding roller 5 that feeds documents P stacked on the document tray 4, a separation roller 8 that separates the documents P one by one, and a document P And a registration roller pair 11 that conveys with the leading ends thereof aligned. The document feeding unit 2 also transports the first read roller 12 as a feeding unit that transports the document to the platen glass 161, the reading guide unit 24 that closely contacts the document to the platen glass 161, and the document that has been read. A second read roller 14. Further, the document feeding unit 2 includes a discharge roller pair 18 as a discharge unit that discharges the document P that has been read out of the apparatus, and a discharge tray 10 from which the document P that has been read is discharged.

  The document tray 4 includes a pair of restricting plates (not shown) arranged to be slidable in the width direction of the document P (direction perpendicular to the transport direction of the document P). The document tray 4 secures conveyance stability during feeding of the document P by regulating a width direction of the document P stacked on the document tray 4 by a regulation plate (not shown).

  The feed roller 5 is provided above the document tray 4 and is located at the home position (solid line position shown in FIG. 1) so as not to hinder the work of setting the document P by the operator. Then, when the feeding operation of the document P is started, the feeding roller 5 moves from the home position to the feeding position (a broken line position shown in FIG. 1), contacts the upper surface of the document P, and feeds the document P. To send. The feeding roller 5 is pivotally supported by an arm (not shown), and moves up and down by swinging the arm.

  The separation roller 8 is provided downstream of the feed roller 5, and is fed by the feed roller 5 by rotating while pressing the separation pad 6 disposed opposite to the feed roller 5 in conjunction with the rotational drive of the feed roller 5. The originals P to be processed are separated and conveyed one by one. The separation pad 6 is made of a rubber material having a smaller friction coefficient than that of the separation roller 8.

  The registration roller pair 11 is provided downstream of the separation roller 8, and the leading edge of the document P that is separated and conveyed one by one by the separation roller 8 abuts on the nip portion to cause a loop in the document P. By aligning the leading edges of the original P, Thereafter, the registration roller pair 11 rotates and conveys the document P toward the platen glass 161.

  The first read roller 12 is provided downstream of the registration roller pair 11, and conveys the document P whose front ends are aligned by the registration roller pair 11 toward the platen glass 161. The reading guide unit 24 is provided downstream of the first lead roller 12, and the original P conveyed to the platen glass 161 by the first lead roller 12 is in close contact with the platen glass 161 along the platen glass 161. I will guide you.

  The second read roller 14 is provided downstream of the reading guide unit 24 and is guided by the reading guide unit 24 and conveys the document P that has been read. The discharge roller pair 18 is provided downstream of the second lead roller 14 and discharges the document P conveyed by the second lead roller 14 to the outside of the apparatus. The discharge tray 10 accommodates the originals P discharged by the discharge roller pair 18 so as to be stacked.

  The placement table glass 3 is a place where the documents P are fixedly placed one by one, and the pressure plate 15 is held by the document feeding unit 2 so as to face the placement table glass 3.

  The reader unit 150 includes a reader unit main body 150 a that holds the platen glass 161 and the mounting table glass 3, a lamp 152 that irradiates light on the document P, and reflected light from the document P that corresponds to the light irradiated on the lamp 152. A plurality of guiding mirrors 153, 155, 156. In addition, the reader unit 150 includes a lens 157 that collects the reflected light guided by the plurality of mirrors 153, 155, and 156, and a CCD 158 that photoelectrically converts the reflected light collected by the lens 157 and outputs it as an image signal. Is provided.

  The reader unit main body 150a supports the document feeding unit 2 so that the placing table glass 3 can be freely opened and closed. The reader unit main body 150a accommodates the lamp 152 and the like so that the lamp 152 and the like are positioned below the reading guide unit 24 through the platen glass 161.

  The lamp 152 and the mirror 153 are attached to the first optical bench 159, and the mirror 155 and the mirror 156 are attached to the second optical bench 151. The first optical bench 159 and the second optical bench 151 are accommodated inside the reader unit main body 150a. The first optical stage 159 and the second optical stage 151 are coupled to a motor (not shown) by wires (not shown), and are controlled to move in parallel with the mounting table glass 3 by the rotational drive of the motor. . The first optical stage 159 and the second optical stage 151 are moved by rotating the motor forward or backward with reference to the position detected by a position sensor (not shown), and fixed to the mounting table glass 3. The placed document P is optically scanned.

  The CCD 158 photoelectrically converts the reflected light guided to the lens 157 via the mirrors 153, 155, and 156, and collected by the lens 157 on the CCD 158, and outputs it as an electronic image signal.

  Next, the reading guide unit 24 of the image reading apparatus 1 according to the present embodiment will be specifically described with reference to FIGS. FIG. 2 is a perspective view showing the reading guide portion 24 of the image reading apparatus 1 shown in FIG. FIG. 3 is an exploded view of the reading guide portion 24 shown in FIG. FIG. 4 is a side view of the reading guide portion 24 located above the platen glass 161. FIG. 5 is a cross-sectional view of the reading guide portion 24 positioned above the platen glass 161. FIG. 6 is a cross-sectional view of the reading guide portion 24 positioned above the platen glass 161.

  As shown in FIG. 2, the reading guide unit 24 includes a platen roller pair 100 as a roller unit that conveys a document along the platen glass 161, a pair of first swing arms 24 c and 24 c, and a pair of second swings. Moving arms 24g, 24g and a white reference plate 103 as a guide plate are provided.

Platen roller pair 100 includes a second platen roller 105 serving as a first roller provided on the downstream side of the second platen roller 105, the first platen roller 104 of the second roller, the. The first platen roller 104 and the second platen roller 105 are connected to a drive transmission unit (not shown) having a motor, a drive pulley, a timing belt, and the like, and are driven to rotate at the same speed as the first lead roller 12. Yes.

  The first platen roller 104 includes a roller unit 104a that conveys the document P and a rotation shaft 104b to which the roller unit 104a is fixed. The roller portion 104a is formed of a rubber member, and a slit portion 104c that exposes the rotation shaft 104b is provided at a substantially center in the axial direction of the rotation shaft 104b to be fixed. The rotating shaft 104b is made of a metal material, and rotates the roller portion 104a fixed to the rotating shaft 104b.

  The second platen roller 105 includes a roller portion 105a that transports the document P and a rotation shaft 105b to which the roller portion 105a is fixed. The roller portion 105a is formed of a rubber member, and a slit portion 105c from which the rotating shaft 105b is exposed is provided at a substantially center in the axial direction of the rotating shaft 105b to be fixed. The rotation shaft 105b is made of a metal material, and rotates the roller portion 105a fixed to the rotation shaft 105b.

As shown in FIG. 3, the first swing arms 24c and 24c are attached to the distal ends of the rotary shaft 104b and the rotary shaft 105b so that the first platen roller 104 and the second platen roller 105 are rotatable. ing. Further, the first swing arms 24c, 24c are biased by a biasing spring 101 (for example, a compression spring) having one end engaged with the first swing arm 24c and the other end engaged with the second swing arm 24g. The second platen roller 105 is biased clockwise around the rotation shaft 105b .

  As shown in FIG. 4, the first swing arm 24c includes a first butting portion 24b and a second butting portion 24f that keep a distance (gap) between the platen roller pair 100 and the platen glass 161 constant. . The first butting portion 24b and the second butting portion 24f abut against the platen glass 161, and thereby the gap between the first platen roller 104 and the platen glass 161 and the gap between the second platen roller 105 and the platen glass 161 are set. Hold.

  The gap amount between the platen roller pair 100 and the platen glass 161 is, for example, about 0.15 to 0.5 mm. The gap amount is determined on the platen glass 161 at the point where both the float regulation of the document P and the transportability are compatible. Further, when the gap amount is 0.15 mm or less, a shock may occur in the reading guide portion 24 when the original P is conveyed in the case of a thick paper original. Further, when the conveyance load increases, the conveyance speed may be blurred, which may cause image blurring.

If the gap amount is 0.5 mm or more, the document P floats on the platen glass 161, the position of the document P varies during image reading (whether or not the float occurs), and the speed of the document P varies. Or, the brightness level fluctuates. This may cause image blurring, image fogging, unevenness, and the like. In the present embodiment, the gap between the first platen roller 104 and the second platen roller 105 and the platen glass 161 is set to be 0.3 mm.

Second swing arm 24g, as in the second platen roller 105及beauty first lead roller 12 is rotatably attached to the tip of the rotation shaft of the rotating shaft 105b and the first lead roller 12 of the second platen roller 105 It has been. Further, the second swing arm 24g has one end attached to the second swing arm 24g and the other end attached to the document feeding portion 2 by a biasing spring 102 (for example, a torsion coil spring), the first lead roller 12. The rotation axis is urged clockwise about the rotation axis.

  The first butting portion 24b and the second butting portion 24f abut against the platen glass 161 by the urging force of the urging spring 101 (compression spring) and the urging spring 102 (torsion coil spring). That is, the second platen roller 105 is rotatably held and the swingable second swinging arm 24g is biased toward the platen glass by the biasing spring 102, whereby the rotation shaft of the second platen roller 105 is rotated. The second butting portion 24f adjacent to 105b hits the mounting table glass.

  Further, the first platen roller 104 is rotatably held, and the first swinging arm 24c swingably held on the rotation shaft 105b of the second platen roller 105 is platened by a biasing spring 101 (compression spring). The glass 161 is biased. Therefore, the first abutting portion 24 b close to the rotation axis of the first platen roller 104 abuts on the platen glass 161.

  The first butting portion 24b and the second butting portion 24f are provided on the first swing arm 24c in the vicinity of both ends of the rotation shafts of the first platen roller 104 and the second platen roller 105, and abut against the platen glass 161. . Therefore, the gap between the first platen roller 104 and the platen glass 161 and the gap between the second platen roller 105 and the platen glass 161 can be held at a constant distance.

  As shown in FIGS. 3, 5, and 6, the white reference plate 103 extends in the same direction (rotation axis direction) as the rotation shaft 104 b of the first platen roller 104 and the rotation shaft 105 b of the second platen roller 105. It is disposed between the first platen roller 104 and the second platen roller 105. The white reference plate 103 includes a rectangular white plate 103a, a first engagement portion 103b supported by a plurality of locations of the rotation shaft 104b of the first platen roller 104, and a plurality of locations of the rotation shaft 105b of the second platen roller 105. And a second engagement portion 103c supported by the second engagement portion 103c.

  The white plate 103a is made of a synthetic resin material, extends in the same direction (rotational axis direction) as the rotation shaft 104b of the first platen roller 104 and the rotation shaft 105b of the second platen roller 105, and is substantially the same as the platen glass 161. It is formed to be parallel. The white plate 103 a has a flat surface facing the platen glass 161, and guides the document P so that the document P conveyed to the platen glass 161 is in close contact with the platen glass 161.

  The first engagement portions 103b are provided at both ends of the white reference plate 103 and substantially at the center in the longitudinal direction, and slits formed on both ends of the rotation shaft 104b of the first platen roller 104 and on the rotation shaft. The rotating shaft 104b is engaged with the portion 104c so as to be rotatable.

  The second engagement portions 103c are provided at both ends of the white reference plate 103 and at a substantially central portion in the longitudinal direction, and slit portions formed on both ends of the rotation shaft 105b of the second platen roller 105 and the rotation shaft. The rotating shaft 105b is engaged with 105c so as to be rotatable.

  Next, the operation of the image reading apparatus 1 will be described with reference to FIG. When the operator instructs to read the image of the document P, the feeding roller 5 swings and comes into contact with the upper surface of the document P to feed the document P. The documents P fed by the feeding roller 5 are separated one by one by the separation roller 8 and conveyed to the registration roller pair 11. In the registration roller pair 11, the leading edge of the conveyed document P is abutted against the nip portion of the registration roller pair 11, and the leading edge of the document P is aligned by causing a loop in the document P. Thereafter, the document P with the leading edges aligned is then conveyed toward the document placement unit 2 by the rotation of the registration roller pair 11.

  Next, the original P is conveyed toward the platen glass 161 by the first lead roller 12. When the document P is conveyed to the platen glass 161, the image of the document P is read on the platen glass 161 by the reader unit 150. Here, the white reference plate 103 is supported at both ends and substantially central portions (three places) of the rotation shaft 104b of the first platen roller 104 and the rotation shaft 105b of the second platen roller 105. Therefore, bending vibration and warpage due to vibration during conveyance of the white plate 103a are suppressed.

  When the reading of the document P by the reader unit 150 is completed, the second read roller 14 is conveyed by the reading guide unit 24 and guides the document P that has been read to the discharge roller pair 18. The original P guided to the discharge roller pair 18 by the second lead roller 14 is discharged outside the apparatus by the discharge roller pair 18 and is stored so as to be stacked by the discharge tray 10.

  In the double-sided mode, the discharge roller pair 18 does not discharge, but switches back, guides to the upper sheet path 9, and conveys toward the registration roller pair 11. When the registration roller pair 11 is reached, the back side of the document P is read in the same manner as described above.

  The image reading apparatus 1 according to the present embodiment having the above-described configuration has the following effects. In the image reading apparatus 1 according to the present embodiment, the white reference plate 103 is supported at both ends and substantially central portions (three places) of the rotation shaft 104b of the first platen roller 104 and the rotation shaft 105b of the second platen roller 105. Has been. Therefore, bending vibration and warpage due to vibration during conveyance of the white plate 103a are suppressed. Thereby, the space | interval of the platen glass 161 and the white board 103a can be stabilized. As a result, for example, even when a non-standard-size document or a perforated document is read, occurrence of fogging or white spots can be suppressed due to a change in the amount of light.

  Further, the platen glass 161 and the white plate 103a have a gap and parallelism in the longitudinal direction, and for example, it is possible to prevent a decrease in white level during image reading when thin paper is used. Further, the strength of the white reference plate 103 against warpage, vibration, etc. can be improved without increasing the lateral width of the white reference plate 103.

  Further, since it is not necessary to increase the lateral width of the reading guide portion 24, the distance between the first platen roller 104 and the second platen roller 105 can be reduced without increasing the size of the image reading apparatus 1. As a result, it is possible to suitably suppress the floating of the document P from the placement table glass 3 at the image reading position. As a result, it is possible to prevent the original P from being fogged and to secure the self-cleaning effect of the platen glass 161 by the original P, thereby suppressing the occurrence of streak images and the like.

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

  For example, in the present embodiment, the white reference plate 103 is supported by both end portions and the central portion (three places) of the rotation shaft 104b of the first platen roller 104 and the rotation shaft 105b of the second platen roller 105. However, the present invention is not limited to this. For example, the structure which is supported by the both ends of the rotating shaft 104b of the 1st platen roller 104 and the rotating shaft 105b of the 2nd platen roller 105, and two or more places between them may be sufficient.

  In the present embodiment, the white reference plate 103 is supported at three positions on both the rotating shaft 104b of the first platen roller 104 and the rotating shaft 105b of the second platen roller 105. It is not limited to this. For example, it may be configured to be supported at three or more locations on one of the rotation shaft 104b of the first platen roller 104 and the rotation shaft 105b of the second platen roller 105. By being supported by any one of the rotating shafts at three or more locations, the warpage of the white plate 103a of the white reference plate 103 can be reduced. And the structure by which the white reference board 103 is supported by less than three places with the other rotating shaft may be sufficient. For example, the white reference plate 103 is supported at three positions in the longitudinal direction on the rotating shaft 104b of the first platen roller 104, and is supported at two positions on both ends in the longitudinal direction by the rotating shaft 105b of the second platen roller 105. May be.

  In the present embodiment, the image reading apparatus 1 has been described. However, the present invention is not limited to this. The image reading apparatus 1 and the image forming apparatus including the image forming unit according to the present embodiment can be suitably used.

DESCRIPTION OF SYMBOLS 1 Image reading device 2 Document feeding part 3 Placement table glass 5 Paper feed roller 12 1st lead roller (feed roller )
14 Second lead roller 15 Pressure plate (pressure plate part)
18 Discharge roller pair (discharge section)
24 Reading guide section 100 Platen roller pair (roller section)
103 White reference plate (guide plate)
103a White plate 103b First engaging portion 103c Second engaging portion 104 First platen roller ( second roller)
104c Slit part 105 Second platen roller ( first roller)
105c Slit part 150 Reader part (image reading means)
161 Platen glass (platen)
P manuscript

Claims (3)

A feed roller for feeding the document to the platen;
Image reading means for reading an image of a document fed from the feeding roller through the platen;
A reading guide unit that is disposed opposite to the image reading unit via the platen and guides a document to be conveyed;
A discharge unit for discharging a document whose image has been read by the image reading unit to the outside of the apparatus,
The reading guide portion is
A first row La for guiding the fed document from the feed roller along said platen, and a second roller disposed downstream of said first roller, said first roller and said second roller The first roller extends in the direction of the rotation axis, guides the document conveyed along the platen, and supports the first roller in a swingable manner about the rotation axis of the feeding roller. A first swing arm that urges the platen toward the platen, and a second roller that swings around the rotation axis of the first roller, and the second roller is directed toward the platen. A second swinging arm that biases ,
The second swing arm has an abutting portion that holds the gap between the first roller and the second roller and the platen at a constant distance by abutting against the platen.
The guide plate is disposed between the first roller and the second roller , and is disposed on both ends of the rotation shafts of the first roller and the second roller and on the rotation shaft located between the both ends. They are respectively supported at at least one location,
An image reading apparatus. The guide plate is a white reference plate.
The image reading apparatus according to claim 1 . The image reading apparatus according to claim 1 or 2 ,
An image forming unit that forms an image read by the image reading device on a sheet,
An image forming apparatus.

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