JP3839214B2 - Image reading apparatus, automatic document feeder, and image forming system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image reading apparatus such as a copying machine, a facsimile apparatus, a scanner apparatus, and the like, an automatic document conveying apparatus that can be mounted on the image reading apparatus, and an image forming system that combines the image reading apparatus and the automatic document conveying apparatus. In particular, the present invention relates to an image reading apparatus, an automatic document feeder, and an image forming system having a reading unit capable of simultaneously reading the front and back surfaces of a document.
[0002]
[Prior art]
In general, in an image reading apparatus having an automatic document conveying device that separates documents one by one from a plurality of documents and automatically conveys them to a slit glass (reading position), when reading image information of a two-sided document Then, after reading the surface of the document with a scanner at the reading position, the document is reversed and conveyed to the reading position again to read the back side of the document.
[0003]
However, in such an image reading apparatus, a complicated reversing path is required for the automatic document conveying device to reverse the document, so that the automatic document conveying device becomes large and complicated. There is a problem that the manufacturing cost of the image reading apparatus increases.
[0004]
In order to solve such a problem, a first image sensor that reads image information on one side of a document on a document transport path and a document transport direction downstream (or upstream) with respect to the first reading unit. In addition, a second image sensor for reading image information on the other side of the document is provided at a position facing the first reading unit across the document conveyance path so that image information on both sides of the document is read simultaneously. There is one that reduces the manufacturing cost of the image reading apparatus by reducing the size and simplification of the automatic document feeder without the need for the document reversal path. (See Kaihei 11-69044).
[0005]
In such an image reading apparatus, in particular, when the first and second image sensors are provided close to the document conveyance direction, the document conveyance path is further shortened. It is possible to further reduce the size of the automatic document feeder.
[0006]
On the other hand, a first white plate and a second white plate, which serve as a reference for reading a document, are installed at positions facing the first image sensor and the second image sensor across the document conveyance path. The document is conveyed through a conveyance path between the first image sensor and the first white plate and a conveyance path between the second image sensor and the second white plate.
[0007]
[Problems to be solved by the invention]
However, in the image reading apparatus including the first and second image sensors, when the image information of the original is read, light reflected on the original surface is photoelectrically changed as image information. Therefore, the light irradiated onto the document surface interferes with each other between the first and second image sensors, and the end portion of the document causes show-through and a back stripe is generated. This causes a problem that the image information cannot be read satisfactorily.
[0008]
In order to prevent such a problem from occurring, it is conceivable that the first and second image sensors are separated from each other so as not to interfere with light by knowing the document conveyance path. In this case, it is necessary to secure a long conveyance path for separating the first and second image sensors. As a result, the size of the automatic document conveying apparatus increases, and the manufacturing cost of the image reading apparatus increases accordingly. The problem of end up occurred.
[0012]
Furthermore, in a reading apparatus that reverses the original and reads the image information on both sides of the original, in addition to the inversion, a reverse discharge mechanism that discharges the original in accordance with the page order is also required. The reversal time of the alignment becomes a waiting time for the entire system, which causes a reduction in system efficiency.
[0013]
  ThereforeMain departureEven if the first reading unit and the second reading unit are arranged close to each other in order to reduce the size of the automatic document feeder, the optical interference between the first reading unit and the second reading unit is prevented. It is an object of the present invention to provide an image reading apparatus and an automatic document conveying apparatus that can read image information of a double-sided document with high accuracy.
[0014]
  Also,Main departureMing eliminates the need for reversing time for reading double-sided originals and aligning the page order, and enables copying with image information that prevents show-through, thereby improving image quality. An object of the present invention is to provide an image forming system with high productivity by reducing the waiting time of the system.
[0016]
[Means for Solving the Problems]
  In order to solve the above problems, the invention according to claim 1Place the document toward the slit glass provided at the scanning position.An image reading apparatus provided with a document conveying means for conveying, provided at the reading position, sandwiching a document conveyance path so as to read image information by exposing one surface and the other surface of the document. An image reading apparatus comprising a first reading unit and a second reading unit provided, wherein the first reading unit and the second reading unit are arranged close to a position where light can interfere with each other along the conveyance path. A light interference preventing member for preventing light interference between the first reading means and the second reading means is disposed on the document transport path between the first reading device and the second reading device;The optical interference preventing member is composed of a roller, and when the length in the width direction of the slit glass is set in the main scanning direction of the first reading means and the second reading means, the length in the rotation axis direction of the roller is Set longer than the slit glass width directionIt is characterized by that.
[0017]
  In this case, since the optical interference preventing member for preventing the mutual interference of the light of the first reading unit and the second reading unit is installed on the document conveyance path between the first reading device and the second reading device, the first reading is performed. Even when the means and the second reading means are arranged close to each other, it is possible to prevent light interference between the first reading means and the second reading means. As a result, while reducing the size of the automatic document feeder, it is possible to read the image information of a two-sided document well by preventing the occurrence of problems such as show-through of the edge of the document and the occurrence of back streaks. Can do.
  Further, since the length in the rotation axis direction of the roller is set longer than the width direction of the slit glass, the light emitted from one of the first reading means and the second reading means is transmitted from the slit glass to the first reading means and the second reading means. It is possible to reliably prevent the other of the light from being received, and to reliably prevent light interference between the first reading means and the second reading means.
[0018]
  In addition, this departureAkira to solve the above problemsBeforeThe light interference preventing member is composed of a roller in contact with the slit glass.
[0019]
In this case, since the optical interference preventing member is composed of a roller that contacts the slit glass, it is possible to smoothly convey the document while preventing light interference between the first reading unit and the second reading unit.
[0020]
  In addition, this departureAkira to solve the above problemsBeforeThe recording roller has a conveyance force for conveying the document in the reading direction.
[0021]
In this case, it is possible to prevent light interference between the first reading means and the second reading means, and it is possible to use both a roller for transporting a document and a light interference preventing member, and a component for transporting the document. Can be reduced.
[0022]
  In addition, this departureAkira to solve the above problemsBeforeThe light interference preventing member is constituted by a pair of rollers that can contact in the direction of the rotation axis and can convey the document while sandwiching it.
[0023]
In this case, since the optical interference preventing member is composed of a pair of rollers, it is possible to smoothly convey the document while preventing light interference between the first reading unit and the second reading unit.
[0026]
  Also bookThe invention is to solve the above-mentioned problems.BeforeThe first reading means is disposed below the slit glass, the second reading means is disposed downstream of the slit glass in the document transport direction, and the roller is disposed on the slit glass document. It is in contact with the upper end surface on the downstream side in the transport direction.
[0027]
In that case, the first reading unit and the second reading unit are arranged by disposing the first reading unit below the slit glass and disposing the second reading unit downstream of the slit glass in the document transport direction. If the roller is brought into contact with the upper end surface on the downstream side in the transport direction of the original of the slit glass where light is most likely to leak when the slit glass is disposed in an oblique direction, the first reading means and the second reading means are mutually connected. It is possible to reliably prevent light interference.
[0028]
  In addition, this departureAkira to solve the above problemsBeforeA light leakage prevention process is performed on the exposed surface on the downstream side in the conveyance direction of the slit glass from the position where the roller contacts.
[0029]
The reason for this will be described. The slit glass is disposed so that the upper surface protrudes from the document conveyance path. This is because if the upper surface of the slit glass is positioned on the lower surface with respect to the document conveying path, the leading edge of the document that has slipped out of the upper surface of the slit glass collides with a frame or the like that constitutes the conveying path, and jamming occurs. However, when the slit glass protrudes from the upper surface of the document conveyance path, the leading edge of the document that has slipped out of the upper surface of the slit glass collides with a frame or the like constituting the conveyance path. This is because it can be prevented and jamming and bending can be prevented.
[0030]
However, when the slit glass is protruded from the document conveyance path to the upper surface in this way, the corners of the slit glass are exposed from the conveyance path, and the portion where light easily leaks increases. Therefore, the invention according to claim 7 reliably prevents light from leaking from the corners of the slit glass by applying a light leakage prevention process to the exposed surface downstream of the slit glass in the conveyance direction from the position where the roller contacts. I was able to do that.
[0031]
  Also bookIn order to solve the above problems, the present inventionHaving slit glass,Hold one side of the moving documentBy exposing through the slit glass,An automatic document conveying apparatus that can be attached to an image reading apparatus including a first reading unit that reads image information and includes a conveyance path that conveys the document toward the first reading unit. Comprises a second reading means for reading the image information of the original by exposing the other side of the original facing the one side of the original in the transport path, and the first reading of the second reading means and the image reading apparatus. And a first reading unit and a second reading unit on the conveyance path between the first reading unit and the second reading unit. Install a light interference prevention member to prevent mutual light interference,The optical interference preventing member is composed of a roller, and when the length in the width direction of the slit glass is set in the main scanning direction of the first reading means and the second reading means, the length in the rotation axis direction of the roller is Set longer than the slit glass width directionIt is characterized by that.
[0032]
In this case, since the optical interference preventing member for preventing the mutual interference of the light of the first reading unit and the second reading unit is installed on the document conveyance path between the first reading device and the second reading device, the first reading is performed. Even when the means and the second reading means are arranged close to each other, it is possible to prevent light interference between the first reading means and the second reading means. As a result, while reducing the size of the automatic document feeder, it is possible to read the image information of a two-sided document well by preventing the occurrence of problems such as show-through of the edge of the document and the occurrence of back streaks. Can do.
[0033]
  The invention according to claim 9 is for solving the above-mentioned problems.In addition, the automatic document feeder is provided to be openable and closable so as to open a conveyance path with respect to the image reading device.It is characterized by.
[0034]
In this case, since the optical interference preventing member is composed of a roller that contacts the slit glass, it is possible to smoothly convey the document while preventing light interference between the first reading unit and the second reading unit.
[0035]
  In addition, this departureAkira to solve the above problemsBeforeThe automatic document feeder is provided so as to be openable and closable so as to open a transport path with respect to the image reading device.
[0036]
In this case, when a document jam occurs at the reading position, the jammed document can be easily removed by opening the automatic document feeder so as to open the conveyance path.
[0037]
In addition, when positioning the roller pair and the slit glass, it is relatively difficult to position the slit glass and the roller pair, and the original collides with the roller and is likely to be skewed, but the roller is in contact with the slit glass. Therefore, when the automatic document feeder is closed, the positioning of the roller with respect to the slit glass is simplified, and the occurrence of document skew can be easily prevented.
[0038]
  In addition, this departureAkira to solve the above problems, Mentioned aboveThe image reading apparatus is combined with an image forming apparatus that forms image information on both sides of a transfer sheet on both sides of a transfer sheet.
[0039]
In this case, since it is possible to perform copying with image information that prevents the show-through, it is not necessary to read the double-sided original and inversion time to align the page order, so that the image quality can be improved and the system waits. An image forming system with high productivity can be obtained with less time.
[0040]
  In addition, this departureAkira, in order to solve the above problems,Mentioned aboveThe automatic document feeder and the first reading unit of the image reading apparatus are combined with an image forming apparatus that forms image information on both sides of the document read by the first reading unit and the second reading unit on both sides of the transfer paper. It is characterized by becoming.
[0041]
In this case, since it is possible to perform copying with image information that prevents the show-through, it is not necessary to read the double-sided original and inversion time to align the page order, so that the image quality can be improved and the system waits. An image forming system with high productivity can be obtained with less time.
[0048]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0049]
1 to 13 are diagrams showing an embodiment of an image reading apparatus, an automatic document feeder, and an image forming system according to the present invention. The image reading apparatus and the image forming system can be applied to a copying machine, a facsimile apparatus, a scanner apparatus, and the like. In this embodiment, a copying machine will be described as an example.
[0050]
First, the configuration will be described. 1 to 3, reference numeral 1 denotes an image forming apparatus including a copying machine. A contact glass 2 and a slit glass 3 having a smaller area than the contact glass 2 are provided on the upper surface of a main body 1 a of the image forming apparatus 1. An automatic document feeder (hereinafter simply referred to as ADF) 4 is provided on the upper surface of the main body 1a. The ADF 4 is provided on the upper surface of the main body 1a through a hinge mechanism (not shown) so as to be opened and closed.
[0051]
A document table 5 is provided on the upper surface of the ADF 4, and a document bundle (not shown) composed of a plurality of documents can be set on the document table 5 on the back side reference (downstream reference in the document transport direction).
[0052]
A document set filler 6 is swingably provided on the back side of the document table 5, and the filler 6 is pressed by the leading end of the document bundle and swings when the document bundle is set on the document table 5. It is supposed to be.
[0053]
The filler 6 is detected by a photo interrupter type document set sensor 100. The document set sensor 100 detects the presence or absence of a document according to the swing position of the filler 6 and outputs detection information to the controller 106. It is supposed to be. Specifically, the filler 6 is detected by the document setting sensor 100 when the document bundle is not set. When the document bundle is set, the filler 6 swings to a position where it is retracted from the document setting sensor 100. The document set sensor 100 detects the presence or absence of a document bundle according to the swing position of the filler 6.
[0054]
Further, when the controller 106 determines that a bundle of documents has been detected based on detection information from the document set sensor 100, a signal is sent to the main body control unit 112 provided on the image forming apparatus 1 side via the interface device 113. Is output.
[0055]
After the detection information is input to the main body control unit 112, an input mode such as a copy mode or the number of copies is input from an operation panel (not shown) provided on the upper surface of the main body 1a, and the copy start key is further pressed. In addition, a paper feed start signal is output to the controller 106.
[0056]
Also, a bottom plate 7 is provided on the back side of the document table 5, and this bottom plate 7 is moved up and down in the direction of the arrow ab by a bottom plate raising motor 108 around a swing fulcrum 7a. The bottom plate 7 is detected by the bottom plate home position sensor 101, and is positioned at the home position detected by the sensor 101 by the bottom plate raising motor 108 when the document bundle is not set.
[0057]
A pickup roller 8 is provided above the bottom plate 7, and this pickup roller 8 is rotatably supported by a support member 9. The support member 9 can be swung in the direction of the arrow cd so as to approach and separate from the bottom plate 7 by a pickup lowering motor 109. When the pickup roller 8 is at a position separated from the bottom plate 7, the bottom plate The proper position sensor 102 detects it.
[0058]
In this embodiment, when a paper feed start signal is input from the main body control unit 112 to the controller 106 via the interface 113, the controller 106 drives the pickup lowering motor 109 to move the support member 9 in the arrow d direction. Thus, the pickup roller 8 is brought into contact with the document bundle.
[0059]
At this time, when the bottom plate 7 is lowered in the direction of the arrow b, the pickup roller 8 is disengaged from the bottom plate appropriate position sensor 102, and therefore the pickup roller 8 is not in contact with the uppermost document in the document bundle. Since the position is not suitable for feeding a document, the bottom plate raising motor 108 is driven to raise the bottom plate 7.
[0060]
At this time, since the pickup roller 8 is pushed up by the bottom plate 7 through the document bundle and is lifted, when the support plate 9 is detected by the appropriate bottom plate position sensor 102 and this sensor 102 is turned on, the pickup roller 8 is moved to the proper feeding position. Will be located. When the bottom plate appropriate position sensor 102 is turned on, the controller 106 stops driving the bottom plate raising motor 108 and stops driving the bottom plate 7.
[0061]
On the other hand, a paper feed belt 10 is provided on the downstream side in the document transport direction with respect to the pickup roller 8, and a reverse roller 12 having a built-in torque limiter is in contact with the paper feed belt 10. The sheet feeding belt 10 is bridged by a driving roller 11a and a driven roller 11b, and is moved around by the driving roller 11a.
[0062]
The paper feed belt 10 is driven in the CW (clockwise) direction as the paper feed direction, and the reverse roller 12 is driven in the CW direction as the paper feed prevention direction. The uppermost original is separated.
[0063]
The separated original is conveyed to the registration driving roller 14a and the registration driven roller 14b via the pull-out driving roller 13a and the pull-out driven roller 13b, and is located downstream of the pull-out driving roller 13a and the pull-out driven roller 13b. When the leading edge of the document is detected by the pull-out sensor 103, the controller 106 is configured so that the paper feed motor 110 that drives the pickup roller 8, the driving roller 11a, and the pull-out driving roller 13a is driven in reverse.
[0064]
Further, the controller 106 drives the pickup lowering motor 109 based on the detection information from the pull-out sensor 103 to raise the pickup roller 8 in the arrow a direction.
[0065]
In the present embodiment, the pickup roller 8, the paper feed belt 10, the pull-out driving roller 13a, the pull-out driven roller 13b, the registration driving roller 14a, and the registration driven roller 14b constitute a document conveying unit.
[0066]
The controller 106 calculates the length of the document in the conveyance direction by counting pulses while the pull-out sensor 103 detects the leading edge and the trailing edge of the document. A plurality of document width sensors 105 are provided in the vicinity of the pull-out sensor 103 in the document width direction. The controller 106 determines the document width direction length based on detection information from the document width sensor 105. Calculate. Therefore, the controller 106 can calculate the size of the document based on the detection information from the pull-out sensor 103 and the document width sensor 105.
[0067]
Here, the paper feed drive system will be described with reference to FIG.
[0068]
In FIG. 4, a paper feed motor pulley 15 is provided on the output shaft of the paper feed motor 110, and this pulley 15 is connected to a paper feed deceleration pulley 17 via a timing belt 16. The paper feed deceleration pulley 17 is connected via a timing belt 18 to a paper feed belt drive pulley 19 connected to a paper feed belt 10 incorporating a one-way clutch. The pulley 19 is connected to a gear portion of an idler gear / pulley 22 via idler gears 20 and 21, and the pulley portion of the idler gear / pulley 22 is connected to a pickup driving pulley 24 that drives the pickup roller 8 via a timing belt 23. It is connected.
[0069]
On the other hand, the paper feed belt drive pulley 19 is provided with a paper feed drive transmission gear 25 on the same axis. This gear 25 has a built-in one-way clutch via idler gears 26 and 27, and a pull-out roller for driving the pull-out drive roller 13a. The drive gear 28 is connected. This pull-out roller drive gear 28 is provided with a pull-out roller drive pulley 29 coaxially, and this pulley 29 is connected to the timing belt 18.
[0070]
The paper feed drive transmission gear 25 is connected to a reverse roller drive gear 31 through an idler gear 30, and the reverse roller drive gear 31 drives the reverse roller 12.
[0071]
On the other hand, in FIGS. 1 to 3, a registration sensor 104 is provided downstream of the registration driving roller 14a. The registration sensor 104 detects the leading edge of the document and outputs the detected information to the controller 106. ing. The controller 106 controls the document in advance based on this detection information, or waits while reading the preceding document.
[0072]
On the other hand, the image forming apparatus 1 below the slit glass 3 is provided with a scanner 32 composed of an image sensor as a first reading means. This scanner 32 is driven by a driving device (not shown) in the direction of arrows ef in FIG. To move to. The driving device is controlled by a main body control unit 81, and when reading image information of a document set on the contact glass 2, the scanner 32 is scanned below the contact glass 2 and the slit glass. The scanner 32 is stopped below the slit glass 3 when reading the image information on one side (front surface) of the original conveyed on the top 3.
[0073]
In addition, an image sensor 107 serving as a second reading unit is provided on the upper right side of FIG. 2 with the slit glass 3 interposed therebetween. The image sensor 107 reads image information on the other side (back side) of the document. It has become.
[0074]
FIG. 5 is a configuration diagram of the image sensor 107. Since the scanner 32 has the same configuration, only the configuration of the image sensor 107 will be described. The image sensor 107 is provided with a plurality of sensor chips 35 in the main scanning direction. When the reflected light of the light irradiated on the document surface from the light source unit 34 is input to the sensor chip 34, it is amplified by the amplifier 36. The A / D converter 37 performs A / D conversion. The A / D converted data is subjected to image processing by the image processing unit 38 and then temporarily stored in the frame memory 39. The stored image data is output from the output control circuit 40 controlled by a predetermined timing to the I / F circuit. The data is output to the main body control unit 11 via the unit 41.
[0075]
On the other hand, in FIG. 1, image information on both sides of the original read by the scanner 32 and the image sensor 107 is output to the main body control unit 112 as image data, and the main body control unit 112 outputs the image data to the writing system. 200 forms an electrostatic latent image on the photosensitive drum 202 constituting the image forming unit 201, and on the photosensitive drum 202 by the cooperation of the charging unit 203, the exposure unit 204, and the developing unit 205 constituting the image reading unit 202. Thus, a visible image of toner is formed.
[0076]
On the other hand, the transfer paper fed from the paper feed system 206 is conveyed to the image forming unit 201, and toner is transferred to one surface of the transfer paper by the transfer unit 207 constituting the image forming unit 201, thereby fixing the fixing system. The transfer paper for which fixing by 208 is completed is conveyed to the reverse paper discharge unit 209.
[0077]
Here, the I path in the reverse paper discharge unit 209 is a straight paper discharge path for the transfer paper to the outside of the image forming apparatus 1, and the II path is a path through which the transfer paper is reversed and discharged in the reverse paper unit 209. In the path III, after the transfer paper is reversed in the reverse discharge unit 209, the transfer paper is re-fed to the double-sided tray, and the other side of the transfer paper is transferred through the image forming process described above. , And discharged through the I path to the outside of the image forming apparatus 1.
[0078]
On the other hand, a roller (light interference prevention member) 42 is provided between the scanner 32 and the image sensor 107, and this roller 42 prevents light interference between the scanner 32 and the image sensor 107. The roller 42 is set so that the length in the rotation axis direction is longer than the width direction of the slit glass 3 when the length of the slit glass 3 in the width direction is the main scanning direction of the scanner 32 and the image sensor 107. . Further, the roller 42 is in contact with the upper end surface of the slit glass 3 on the downstream side in the conveying direction, and is pressed against the slit glass 3 by a spring 43.
[0079]
The roller 42 is composed of a rotating shaft and a cylindrical soft rubber provided on the outer peripheral portion thereof, and is rotated in such a manner that the outer peripheral portion of the soft rubber is lightly slid on the slit glass 3 by being coated with polyurethane rubber. It comes to contact.
[0080]
Here, in FIG. 2, reference numeral 44 a is a paper discharge driving roller, 44 b is a paper discharge driven roller, and these rollers 44 a and 44 b discharge a document that has been read by the scanner 32 and the image sensor 107 to a paper discharge tray 45. It is like that.
[0081]
Further, the paper discharge drive roller 44a is driven by the transport motor 111 together with the registration drive roller 14a and the roller 42. This transport drive system will be described with reference to FIG.
[0082]
In FIG. 6, a conveyance motor pulley 46 is provided on the output shaft of the conveyance motor 111, and this pulley 46 is connected via a timing belt 47 to a registration roller driving pulley 48 that drives the registration driving roller 14a. The pulley 48 is connected to a roller driving pulley 50 that drives the roller 42 via a timing belt 49. The timing belt 48 is provided with a tension roller 51. The tension roller 51 keeps the tension of the timing belt 48 constant. Further, a paper discharge roller drive pulley 53 connected to a paper discharge drive roller 44 via a timing belt 48 is connected to the transport motor pulley 46.
[0083]
On the other hand, as shown in FIGS. 7 to 9, both end portions of the roller 42 are rotatably supported by support portions 53a of a pair of side frames 53 provided in the ADF 4, and springs 43 attached to the support members 53a. Is pressed against the slit glass 3. Further, a rib 53b is provided at the lower end of the frame 53, and this rib 53b comes into contact with the conveyance guide 56 on the upper surface of the main body 1a of the image reading formation 1.
[0084]
A reflection plate 54 is provided between the frames 53, and the reflection plate 54 constitutes a document conveyance path together with a conveyance guide 56 on the upper surface of the main body 1a.
[0085]
A white plate (second white plate) 55 is provided on the upper surface of the main body on the downstream side of the slit glass 3, and this white plate 55 is arranged to face the image sensor 107 across the document conveyance path. And is disposed on the same plane as the surface of the slit glass 3.
[0086]
The reflecting plate 54 has a slit 54a, and the roller 42 is in contact with the slit glass 3 through the slit 54a. A slit 54 b is formed in the reflecting plate 54, and a glass 58 is fitted into the slit 54 b, and an image sensor 107 is placed on the upper surface of the glass 58, and the image sensor 107 is white through the glass 58. Opposite the plate 55. The reflection plate 54 also serves as the white plate of the scanner 32 and constitutes a first white plate. That is, in the present embodiment, the image sensor 107 and the first white plate are integrally held with the reflection plate 54.
[0087]
Further, one end of a spring (pressing member) 56 is attached to the upper surface of the reflecting plate 54. The other end of the spring 56 is supported by the frame of the ADF 4, and the reflecting plate 54 is connected to the scanner 32 and the white plate 55 side. It is designed to be pressed.
[0088]
Further, a rib (projection) 59 is provided at the lower end portion of the reflection plate 54, and the rib 59 is in contact with the conveyance guide 56. Therefore, when the reflecting plate 54 is pressed toward the scanner 32 and the white plate 55 by the spring 57, the reflecting plate 54 can be separated from the white plate 55 and the slit glass 3 at a constant interval.
[0089]
In FIG. 2, reference numeral 60 is a pressure plate provided on the lower surface of the ADF 4 to press the document against the contact glass 2.
[0090]
Next, a paper feeding operation and a document reading operation will be described based on the flowcharts of FIGS.
[0091]
FIG. 10 is a flowchart showing the paper feeding operation, and this flow is executed by the controller 80. First, it is determined whether or not a document has been set based on detection information from the document set sensor 100 (step S1). If no document is set, it is determined whether or not the bottom plate home position sensor 6 is turned on (step S2). If it is turned on, the bottom plate 7 moves to a position indicated by an arrow b in FIG. Thus, the bottom plate raising motor 108 is turned off by determining that it is at the home position (step S3).
[0092]
If the bottom plate home position sensor 6 is not turned on, it is determined that the bottom plate 7 is not at the home position, the bottom plate raising motor 108 is turned on, and the bottom plate 7 is moved to the position indicated by the arrow b in FIG. To move to the home position (step S4).
[0093]
On the other hand, when it is determined that a document bundle has been set on the document table 5 based on detection information from the document setting sensor 100, it is determined whether a paper feed signal or a first-out signal has been input from the main body control unit 112. (Step S5) When input is made, the pickup lowering motor 109 is turned on counterclockwise to lower the pickup roller 8 through the support member 9. Next, it is determined whether or not the bottom plate appropriate position sensor 102 is turned on (step S7). If the bottom plate appropriate position sensor 102 is not turned on, it is judged that the document bundle is not located at the optimum paper feed position, and the bottom plate raising motor is determined. 108 is turned on to raise the bottom plate 7 (step S8).
[0094]
If the bottom plate appropriate position sensor 102 is turned on, it is determined that the original bundle is located at the optimum paper feed position, and the bottom plate raising motor 108 is turned off (step S9). Next, the paper feed motor 111 is driven to start feeding the original (step S10).
[0095]
Next, it is determined whether or not the pull-out sensor 103 is turned on (step S10). If the pull-out sensor 103 is turned on, it is determined that the leading edge of the document has been detected. The rotation pulse count is started (step S12).
[0096]
Next, after the paper feeding motor 110 is driven in the counterclockwise direction (step S13), the pickup lowering motor 109 is turned on to start raising the pickup roller 8 (step S14).
[0097]
Next, it is determined whether or not the paper feed motor 110 has reached a predetermined pulse count (step S15). (Step S16).
[0098]
Here, the document feeding operation in steps S10 and S13 will be described in detail.
[0099]
First, when the paper feed motor 42 rotates in the clockwise direction indicated by the solid line, the one-way clutch built in the paper feed belt drive pulley 19 is locked, and the drive roller 10a rotates to feed the paper feed belt 10 in the paper feed direction. Move around clockwise. Further, since the driving force is transmitted from the paper feed drive transmission gear 25 to the idler gear / pulley 22 through the idler gears 20 and 21, the pickup roller 8 is rotationally driven in the paper feed direction by the pickup drive pulley 24.
[0100]
Further, since the driving force is transmitted from the paper feed drive transmission gear 25 to the reverse roller drive gear 31 via the idler gear 30, the reverse roller 12 rotates in the clockwise direction, which is the separation preventing direction. Further, the pull-out drive gear 28 incorporating the one-way clutch via the idler gears 26 and 27 locks the rotation shaft of the pull-out drive roller 13a, so that the driving force is transmitted and the feed-out direction rotates in the paper feeding direction.
[0101]
At this time, the pull-out drive pulley 29 in which the one-way clutch is built is in a sliding direction so that the drive from the timing belt 18 is not transmitted to the rotation shaft of the pull-out drive roller 13a.
[0102]
Next, when the paper feed motor 110 rotates counterclockwise, the one-way clutch of the paper feed drive pulley 19 is in a sliding direction with respect to the shaft of the drive roller 11a of the paper feed belt 10, so that the paper feed belt 10 and the pickup roller 8 are moved. Is stopped.
[0103]
At this time, the pull-out driving roller 11a continues to rotate in the paper feeding direction as the driving force is transmitted from the timing belt 18 because the pull-out driving pulley 29 is in the locking direction. As a result, the original document that has reached the pull-out sensor 103 is pulled out of the separation unit by the pull-out driving roller 13a and the pull-out driven roller 13b.
[0104]
At this time, the driving roller 11a to which the paper feeding belt 10 is bridged has a built-in one-way clutch, so that it is rotated. Also, since the reverse roller 12 has a built-in torque limiter, it is rotated or stopped in the same manner as the paper feed belt 10 depending on the state of the next original. As a result, it is possible to prevent the next original from being separated.
[0105]
On the other hand, it is determined whether or not the carry motor 111 is driven in step S17 (step S17). If driven, the paper feed motor 110 is stopped and the above-described first-out process is completed (step S18). It is determined whether or not the next original can be read (step S19). If reading is possible, the paper feed motor 110 is driven in the clockwise direction to execute the document feed process described above.
[0106]
If it is determined in step S17 that the conveyance motor 111 is not driven, after the conveyance motor 21 is turned on, it is determined whether or not the leading edge of the document is detected by the registration sensor 104 (step S22). When the registration sensor 104 is turned on and the leading edge of the document is detected, the conveyance motor 111 is turned off to wait for the document at the reading position.
[0107]
Next, the document reading operation will be described based on the flowchart of FIG. FIG. 11 is a flowchart showing the reading operation, and this flow is executed by the controller 106.
[0108]
First, it is determined whether or not a reading start signal has been input from the main body control unit 112 (step S31). If it has been input, the speed at the image scale based on the information sent in advance from the main body control unit 112 is determined. Then, the transport motor 111 is driven (step S32).
[0109]
Next, the drive pulse of the carry motor 111 is counted from the time when the drive of the carry motor 111 is started, and it is determined whether or not this drive pulse has become a predetermined pulse (step S33). When the driving pulse becomes a predetermined pulse, it is determined that the leading edge of the document has reached the upper surface of the scanner 32, and a front surface DF gate signal indicating that the image is within the effective range is transmitted to the main body control unit 112. Reading of the surface of the document is started (step S34).
[0110]
Next, the drive pulse of the transport motor 111 is counted to determine whether or not this drive pulse has become a predetermined pulse (step S35). When this drive pulse becomes a predetermined pulse, it is determined that the leading edge of the document has reached the lower surface of the image sensor 107, and reading of image information on the back surface of the document is started by the image sensor 107 (step S36). At this time, the document is guided by the roller 42 and conveyed along a conveyance path defined by the reflection plate 54 and the conveyance guide 56.
[0111]
Next, it is determined whether or not the registration sensor 104 is turned off (step S37). If the registration sensor 104 is turned off, it is determined that the trailing edge of the document has passed through the trailing edge of the registration sensor 104. Then, the drive pulse of the transport motor 111 is counted to determine whether or not this drive pulse has become a predetermined pulse (step S38). If this drive pulse becomes a predetermined pulse, it is determined that the trailing edge of the document has come to the upper surface of the scanner 32, and the front DF gate signal transmitted to the main body control unit 112 for transmission is turned off (step S39).
[0112]
Next, the drive pulse of the transport motor 111 is counted to determine whether or not this drive pulse has become a predetermined pulse (step S40). When this drive pulse becomes a predetermined pulse, it is determined that the trailing edge of the document has come to the lower surface of the image sensor 107, and reading of the back surface of the document is completed (step S41).
[0113]
Next, it is determined whether or not the next original is at the first-out position. If it is not at the first-out position, the drive pulse of the transport motor 111 is counted to determine whether or not this drive pulse has become a predetermined pulse (step). S43). When this drive pulse becomes a predetermined pulse, it is determined that the trailing edge of the document has passed through the paper discharge drive roller 44a and the paper discharge driven roller 44b, and the transport motor 111 is turned off to complete the document reading process. .
[0114]
Image information of the double-sided original read by the scanner 32 and the image sensor 107 is output to the main body control unit 112, and the main body control unit 112 operates the writing system 200, the image forming unit 201, and the reverse paper discharge unit 209, Transferred to both sides of transfer paper.
[0115]
As described above, in the present embodiment, since the roller 42 for preventing the mutual interference of light between the scanner 32 and the image sensor 107 is installed on the document conveyance path between the scanner 32 and the image sensor 107, the scanner 32 and the image sensor 107. Can be prevented from interfering with each other between the scanner 32 and the image sensor 107. As a result, while downsizing the ADF 4, it is possible to read the image information of the double-sided original document by preventing occurrence of problems such as show-through of the edge of the original document and the occurrence of back streaks.
[0116]
Further, since the roller 42 is in contact with the slit glass 3, the original can be smoothly conveyed while preventing the light interference between the scanner 32 and the image sensor 107.
[0117]
Further, since the length in the rotation axis direction of the roller 42 is set to be longer than the width direction of the slit glass 3, light irradiated from one of the scanner 32 and the image sensor 107 is transmitted from the slit glass 3 to the other of the scanner 32 and the image sensor 107. Light can be reliably prevented from being received, and light interference between the scanner 32 and the image sensor 107 can be reliably prevented.
[0118]
Further, since the roller 42 has a conveying force for conveying the document in the reading direction, the roller for conveying the document can be used as a member for preventing light interference, and the number of parts for conveying the document can be reduced. be able to.
[0119]
Since the scanner 32 is disposed below the slit glass 3 and the image sensor 107 is disposed downstream of the slit glass 3 in the document transport direction, the scanner 32 and the image sensor 107 are sandwiched between the slit glass 3. When arranged in an oblique direction, the roller 42 can be brought into contact with the upper end surface on the downstream side in the document transport direction of the slit glass 3 where light is most likely to leak, so that light interference between the scanner 32 and the image sensor 107 can be ensured. Can be prevented.
[0120]
In addition, the reflecting plate 54 is integrated with the image sensor 107, and the reflecting plate 54 is supported so that the reflecting plate 54 is separated from the white plate 55 and the slit glass 3 at a predetermined interval. Since the rib 59 and the spring 57 are provided, the clearance between the slit glass 3 and the reflecting plate 54 that also serves as the white plate and the clearance between the reflecting plate 55 and the reflecting plate 54 can be set constant.
[0121]
That is, the clearance between the reflecting plate (white plate) and the white plate 55 with respect to the document conveyance path can be made constant with a simple configuration, and a double-sided document can be read with high accuracy. Further, since the integrated image sensor 107 and the white plate 55 are simply assembled to the ADF 4, the clearance between the reflector (white plate) 54 and the white plate 55 with respect to the document conveyance path can be made constant with a simple configuration. In addition, the assembling property of the white plate 55 and the image sensor 107 can be improved.
[0122]
Further, since the ADF 4 is provided on the upper surface of the main body 1a of the image forming apparatus 1 so as to be freely opened and closed, when the ADF 4 is closed with respect to the main body 1a, the reflecting plate 54 is pressed against the scanner 32 and the white plate 55 by the spring 57. The rib 59 makes it possible to make the clearance between the slit glass 3 and the reflecting plate 54 that also serves as the first white plate and the clearance between the white plate 55 and the reflecting plate 54 constant.
[0123]
In addition to this, when an ADF 4 is provided on the upper surface of the main body 1a of the image forming apparatus 1 so as to be freely opened and closed, when an original jam occurs at the reading position, the ADF 4 is opened so as to open the conveyance path. The original can be easily removed. Further, when the ADF 4 is closed, the positioning of the roller 42 with respect to the slit glass 3 can be simplified, and the occurrence of document skew can be easily prevented.
[0124]
In addition, since the image forming system is configured by incorporating the scanner 32 and the image sensor 107 into the image forming apparatus 1, image information that prevents the show-through is eliminated by eliminating the inversion time for reading the double-sided original and aligning the page order. Since copying can be performed, the image quality can be improved and an image forming system with high productivity can be obtained by reducing the waiting time of the system.
[0125]
In the present embodiment, the optical interference prevention member is constituted by the roller 42 that contacts the slit glass 3. However, the present invention is not limited to this, and as shown in FIG. Thus, the rollers 61a and 61b that can be conveyed may be used. Even in this case, it is possible to smoothly convey the document while preventing the light interference between the scanner 32 and the image sensor 107.
[0126]
Further, as shown in FIG. 13, for example, a light leakage prevention portion 61 subjected to a leakage prevention process for applying a black color may be formed on the exposed surface on the downstream side in the conveyance direction of the slit glass 3 from the position where the roller 42 contacts. good.
[0127]
In such a case, the following effects can be obtained.
[0128]
As shown in FIG. 13, the slit glass 3 is disposed so that its upper surface protrudes from the document transport path. This is because if the upper surface of the slit glass 3 is positioned on the lower surface with respect to the document conveyance path, the leading edge of the document that has slipped out of the upper surface of the slit glass 3 collides with a frame or the like that constitutes the conveyance path, and a jam occurs When the slit glass 3 protrudes from the upper surface of the document conveyance path, the leading edge of the document that has slipped out of the upper surface of the slit glass 3 forms a frame or the like constituting the conveyance path. This is because the collision can be prevented, and the occurrence of jamming and bending can be prevented.
[0129]
However, when the slit glass 3 is protruded from the document conveyance path to the upper surface in this way, the corners of the slit glass 3 are exposed from the conveyance path, and the portion where light is likely to leak increases. Therefore, by performing a light leakage prevention process on the exposed surface on the downstream side in the conveyance direction of the slit glass 3 from the position where the roller 42 is in contact, it is possible to reliably prevent light from leaking from the corner of the slit glass 3.
[0130]
【The invention's effect】
  BookAccording to the invention, even when the first reading unit and the second reading unit are arranged close to each other, it is possible to prevent light interference between the first reading unit and the second reading unit. As a result, while reducing the size of the automatic document feeder, it is possible to read the image information of a two-sided document well by preventing the occurrence of problems such as show-through of the edge of the document and the occurrence of back streaks. Can do.
  Further, since the length in the rotation axis direction of the roller is set longer than the width direction of the slit glass, the light emitted from one of the first reading means and the second reading means is transmitted from the slit glass to the first reading means and the second reading means. It is possible to reliably prevent the other of the light from being received, and to reliably prevent light interference between the first reading means and the second reading means.
[0131]
  Also bookAccording to the invention, since the optical interference preventing member is composed of the roller that contacts the slit glass, the original can be smoothly conveyed while preventing the light interference between the first reading means and the second reading means. it can.
[0132]
  Also bookAccording to the invention, the light interference preventing member isLaTherefore, it is possible to smoothly convey the document while preventing light interference between the first reading unit and the second reading unit.
[0133]
  Also bookAccording to the invention, since the optical interference preventing member is composed of the roller pair, the original can be smoothly conveyed while preventing the light interference between the first reading unit and the second reading unit.
[0135]
  In addition, the present inventionThe first reading means and the second reading means are provided by disposing the first reading means below the slit glass and disposing the second reading means downstream of the slit glass in the document transport direction. When the roller is disposed in an oblique direction with the slit glass interposed therebetween, the first reading means and the second reading means can be realized by bringing the roller into contact with the upper end surface on the downstream side in the document transport direction of the slit glass where light is most likely to leak. Mutual light interference can be reliably prevented.
[0136]
  Also bookAccording to the invention, it is possible to reliably prevent light from leaking from the corners of the slit glass by performing the light leakage prevention process on the exposed surface on the downstream side in the conveyance direction of the slit glass from the position where the roller contacts.
[0137]
  Also bookAccording to the invention, the optical interference preventing member for preventing the mutual interference of the light of the first reading means and the second reading means is installed on the document conveyance path between the first reading device and the second reading device. Even when the first reading unit and the second reading unit are arranged close to each other, it is possible to prevent light interference between the first reading unit and the second reading unit. As a result, while reducing the size of the automatic document feeder, it is possible to read the image information of a two-sided document well by preventing the occurrence of problems such as show-through of the edge of the document and the occurrence of back streaks. Can do.
[0138]
  Also bookAccording to the invention, since the optical interference preventing member is composed of the roller that contacts the slit glass, the original can be smoothly conveyed while preventing the light interference between the first reading means and the second reading means. it can.
[0139]
  Also bookAccording to the inventionIfWhen a document jam occurs at the reading position, the jammed document can be easily removed by opening the automatic document feeder so as to open the conveyance path. Further, when the automatic document feeder is closed, the positioning of the roller with respect to the slit glass is simplified, and the occurrence of document skew can be easily prevented.
[0140]
  Also bookAccording to the present invention, it is possible to make a copy with image information that prevents the show-through, without requiring a reversing time for reading a double-sided original and aligning the page order. Therefore, it is possible to obtain a highly productive image forming system.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an image reading apparatus, an automatic document feeder, and an image forming system according to an embodiment of the present invention, and is a schematic configuration diagram of the image forming apparatus including an image reading apparatus and an ADF.
FIG. 2 is a schematic configuration diagram of an ADF provided in the image forming apparatus according to the embodiment.
FIG. 3 is a block diagram illustrating a circuit configuration of an ADF according to an embodiment.
FIG. 4 is a configuration diagram of a paper feed drive system according to an embodiment.
FIG. 5 is a configuration diagram of an image sensor according to an embodiment.
FIG. 6 is a configuration diagram of a transport drive system according to an embodiment.
FIG. 7 is a side view showing the configuration around the slit glass of the ADF of one embodiment.
FIG. 8 is a diagram of a reflector according to an embodiment as viewed from below.
FIG. 9 is an external perspective view of a reflector, a roller, and an image sensor according to an embodiment.
FIG. 10 is a flowchart of a sheet feeding operation according to an embodiment.
FIG. 11 is a flowchart of a document reading operation according to an embodiment.
FIG. 12 is a view showing another shape of the optical interference prevention member of one embodiment.
FIG. 13 is a view showing a slit glass having a structure subjected to a light leakage prevention process according to an embodiment.
[Explanation of symbols]
  1 Image forming device
  1a body
  3slitGlass (reading position)
  4 ADF
  8 Pickup roller (document transport means)
  10 Paper feed belt (document transport means)
  13a Pull-out drive roller (document conveying means)
  13b Pull-out driven roller (document conveying means)
  14a Registration drive roller (document conveying means)
  14b Registration driven roller (document conveying means)
  42 Roller (light interference prevention member)
  54 reflector
  55 White plate (second white plate)
  56 Transport Guide
  57 Spring (Pressing member)
  59 Ribs (protrusions)
  61a, 61b Roller

Claims (11)

An image reading apparatus provided with a document conveying means for conveying a document toward a slit glass provided at a reading position ,
A first reading unit and a second reading unit which are provided at the reading position and which are provided on both sides of the conveyance path of the original so as to expose one side and the other side of the original to read image information; ,
In the image reading apparatus in which the first reading unit and the second reading unit are arranged close to a position where light can interfere with each other along the conveyance path,
An optical interference preventing member for preventing light interference between the first reading unit and the second reading unit is installed on the document conveyance path between the first reading device and the second reading device;
The optical interference preventing member is composed of a roller, and when the length in the width direction of the slit glass is set in the main scanning direction of the first reading means and the second reading means, the length in the rotation axis direction of the roller is An image reading apparatus characterized in that it is set longer than the width direction of the slit glass . The image reading apparatus of the prior SL light interference prevention member according to claim 1, wherein the constructed from the roller in contact with the slit glass.   The image reading apparatus according to claim 2, wherein the roller has a conveying force for conveying the document in a reading direction.   2. The image reading apparatus according to claim 1, wherein the optical interference preventing member is constituted by a pair of rollers which can be conveyed while being in contact with each other in the rotation axis direction and sandwiching the document. The first reading unit is disposed below the slit glass, and the second reading unit is disposed downstream of the slit glass in the document conveyance direction,
  5. The image reading apparatus according to claim 2, wherein the roller is in contact with an upper end surface of the slit glass on the downstream side in the document conveyance direction. 6. The image reading apparatus according to claim 2, wherein a light leakage prevention process is applied to an exposed surface on the downstream side in the conveyance direction of the slit glass from a position where the roller contacts. A slit glass is attached to an image reading apparatus having a first reading means for reading image information by exposing one side of a moving document through the slit glass, and the document is attached to the first document. In an automatic document feeder provided with a conveyance path for conveyance toward one reading means,
  The automatic document feeder includes a second reading unit that exposes the other surface of the document facing the one surface of the document to read the image information of the document.
  The second reading unit and the first reading unit of the image reading apparatus are provided close to a position where light from the exposure can interfere along the conveyance path, and between the first reading unit and the second reading unit. A light interference preventing member for preventing light interference between the first reading means and the second reading means is installed on the transport path,
  When the light interference preventing member is constituted by a roller, and the width direction length of the slit glass is set in the main scanning direction of the first reading unit and the second reading unit, the length of the roller in the rotation axis direction is An automatic document feeder characterized by being set longer than the width direction of the slit glass. 8. The automatic document feeder according to claim 7, wherein the interference preventing member is composed of a roller that contacts the slit glass. 9. The automatic document conveying device according to claim 7, wherein the automatic document conveying device is provided so as to be openable and closable so as to open a conveying path with respect to the image reading device. 7. An image obtained by combining the image reading apparatus according to claim 1 with an image forming apparatus that forms image information on both sides of a document on both sides of a document read by the image reading apparatus. Forming system. 10. The image information on both sides of the original read by the first reading means and the second reading means is transferred to both sides of the transfer paper on the automatic document feeder according to claim 7 and the first reading means of the image reading apparatus. the image forming system characterized by comprising a combination of an image forming apparatus for forming an image on.

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