JP2012065067A - Image reading apparatus and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading apparatus which removes dust such as paper powder adhering onto a contact glass, thereby preventing an abnormal image and obtaining image information to form a high-definition image finally.SOLUTION: A document on the contact glass is irradiated with light, and the reflected light forms an image by a lens via a mirror provided to a travel object, the image being read by a sensor. In the image reading apparatus like this, the contact glass is covered with a transparent and cylindrical sheet member, and the sheet member moves in shading operation.

Description

  The present invention relates to an image reading apparatus and an image forming apparatus that read an image of a document transported on a contact glass by an ADF (automatic document transport device) such as a copying machine, a facsimile machine, and a scanner by an image sensor.

Among image reading apparatuses, there is a type called a sheet-through method in which a document is transported in the sub-scanning direction and the document being transported is read by a reading unit placed at a fixed position.
According to this method, when reading, the document passes while contacting the contact glass, so that it is inevitable that dust attached to the image surface side of the document adheres to the contact glass. If such an adhering matter adheres to the reading position of the contact glass, the influence appears in the read image signal, and the finally formed image is disturbed, thereby degrading the image quality.
Deposits such as dust on the contact glass lead to image deterioration not only in the sheet-through method but also in any method, and only occur as dots in image reading devices that fix the document and sub-scan the reading unit. On the other hand, in the case of a sheet-through type reading apparatus, a so-called vertical streak is generated which is connected in the sub-scanning direction, and the influence is much greater.
Conventionally, there are several means for cleaning the contact glass surface as disclosed in Patent Document 1, but dust and dust remain on the contact glass surface or in the vicinity thereof, which only makes the appearance worse. In addition, when dust or the like cannot be completely removed, dust may move to the reading position of the original image at some moment, which may cause vertical stripes in the formed image.
Patent Document 2 discloses a moving unit for reciprocating the transparent member in the document conveying direction, and a control unit for performing image reading at a reading position while conveying the document and moving the transparent member by the moving unit. However, depending on the position where the document is stopped, the document may be damaged.

  Therefore, the present invention has been made in view of the above problems, and its problem is to remove dust such as paper dust adhering to the contact glass, to prevent abnormal images, and to achieve a high image finally formed. An object of the present invention is to provide an image reading apparatus capable of obtaining high-quality image information.

The features of the present invention, which is a means for solving the above problems, are listed below.
The image reading apparatus of the present invention irradiates a document conveyed on a contact glass at a constant speed with light, forms an image with a lens through a mirror provided in a traveling body, and reads the image with a sensor. In the apparatus, the contact glass is covered with a transparent cylindrical sheet member, and the sheet member moves during a shading operation.
In the image reading apparatus of the present invention, the image reading apparatus further separates the originals one by one in a state where the traveling body is fixed, and conveys the originals on the contact glass of the image reading unit at a constant speed. It is characterized by being linked to an automatic document feeder.
The image reading apparatus of the present invention is further characterized in that a driving source for conveying the sheet member is the same as a driving source of the traveling body.
Further, the image reading apparatus of the present invention is further characterized in that the roller holding the sheet member is configured to transmit the drive only in one direction.
In the image reading apparatus of the present invention, the sheet member further includes a cleaning mechanism on the upstream side of the reading position with respect to the conveyance direction of the sheet member. The distance between the cleaning mechanism and the reading position is larger.
Further, the image reading apparatus of the present invention is further characterized in that the diameter of the roller for holding the sheet member is larger than the thickness of the contact glass.
The image reading apparatus of the present invention is further characterized in that the transmittance of the sheet member has a characteristic of cutting a longer wavelength side than the near infrared region.

  The image forming apparatus of the present invention includes an image carrier that carries an electrostatic latent image, a charging device that is disposed in contact with or close to the image carrier and charges the surface of the image carrier, and the image carrier. An exposure device that exposes the surface of the body and writes an electrostatic latent image, a developing device that visualizes the latent image formed on the surface of the image carrier with toner, and a visible image on the surface of the image carrier A transfer device for transferring to the member; a cleaning device disposed downstream of the transfer device for cleaning the toner on the surface of the image carrier; and a fixing device for melting and fixing the toner on the recording member. In the image forming apparatus, any one of the image reading apparatuses described above is used.

  According to the present invention, which is a means for solving the above problems, when the image is read by irradiating the original with light, the position of the transparent sheet corresponding to the reading position changes every time. It can be taken away from the position, and abnormal images can be reduced. Further, since the sheet member operates only during shading and operates, it is possible to provide an image forming apparatus that does not damage the document when it stops abnormally.

1 is a cross-sectional view illustrating a configuration of an automatic document feeder (ADF) that is linked to an image reading apparatus of the present invention. FIG. 3 is a block diagram illustrating control of an automatic document feeder (ADF) that is linked to the image reading apparatus of the present invention. FIG. 3 is a block diagram illustrating control of an automatic document feeder (ADF) that is linked to the image reading apparatus of the present invention. 1 is a schematic diagram illustrating a configuration of an image reading apparatus of the present invention. 1 is a schematic diagram illustrating a configuration of an image reading apparatus of the present invention. FIG. 2 is a schematic diagram illustrating a configuration of an image reading device / automatic document feeder near a general image reading unit. It is the schematic which shows the structure of the sheet | seat member of the image reading apparatus of this invention. It is the schematic which shows the structure of the sheet | seat member of the image reading apparatus of this invention. It is the schematic which shows the structure of the sheet | seat member of the image reading apparatus of this invention. It is the schematic explaining operation | movement of the image reading apparatus of this invention. It is the schematic explaining operation | movement of the image reading apparatus of this invention. FIG. 3 is a perspective view illustrating a schematic configuration of a drive source that drives a sheet member of the image reading apparatus of the present invention. FIG. 3 is a side view of a schematic configuration of a drive source that drives a sheet member of the image reading apparatus of the present invention. It is the schematic explaining the drive of the sheet | seat member of the image reading apparatus of this invention. It is the schematic explaining the diameter of the roller holding the transparent sheet of the image reading apparatus of this invention, and the thickness of contact glass. 1 is a schematic diagram illustrating a configuration of an image forming apparatus incorporating an image reading apparatus of the present invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

The present embodiment relates to an automatic document feeder (hereinafter, referred to as “ADF”) used in an apparatus that reads an original to be read to a fixed reading device unit and performs image reading while being conveyed at a predetermined speed. .
FIG. 1 is a cross-sectional view showing a configuration of an automatic document feeder (ADF) interlocked with the image reading apparatus of the present invention.
FIG. 2 is a block diagram showing the control of the automatic document feeder (ADF) linked to the image reading apparatus of the present invention.
FIG. 3 is a block diagram showing the control of the automatic document feeder (ADF) linked to the image reading apparatus of the present invention.
The basic configuration, operation, and action of FIG. 1 will be described based on the cross-sectional view of this apparatus and the control block diagrams of FIGS.
A document setting section A for setting a document bundle 501 of documents 7 to be read, a separation feeding section B for separating and feeding the documents 7 one by one from the set document bundle 501, and a fed document 7 , And a turn portion D that turns the conveyed document 7 and conveys the document surface toward the reading side (downward). A first reading / conveying unit E for reading the front surface image of the original document 7 from below the contact glass, a second reading / conveying unit F for reading the back side image of the original document 7 after reading, and the original document 7 whose front and back have been read. From the paper discharge unit G to be discharged outside the machine, the stack unit H for stacking and holding the original 7 after reading, the driving units 101 to 105 for driving these conveying operations, and the controller unit 100 for controlling a series of operations. It is configured.

The document bundle 501 of the document 7 to be read is set on the document table 502 including the movable document table 503 with the document surface facing upward. Further, the width direction of the original bundle 501 of the original 7 is positioned in a direction perpendicular to the conveying direction by a side guide (not shown). The setting of the document 7 is detected by a set filler 504 and a set sensor 505 and transmitted to the main body control unit 111 by an I / F (interface) 107.
Further, the length of the document 7 in the conveyance direction is determined by a document length detection sensor 530 or 531 provided on the document table 502. As the document length detection sensor 530 or 531, a reflection type sensor or an actuator type sensor that can detect even one document 7 is used. Further, the document length detection sensor 530 or 531 needs to be arranged so that at least whether the size of the same document 7 is vertical or horizontal can be determined. As a result, the direction and size of the document 7 can be detected, and the conveyance of the document 7 can be controlled.
The movable document table 503 is configured to be moved up and down in the directions a and b shown in the drawing by the bottom plate raising motor 105. When the set filler 504 and the set sensor 505 detect that the document 7 is set, the bottom plate raising motor 105 is provided. Is moved forward to raise the movable document table 503 so that the uppermost surface of the bundle of documents 7 contacts the pickup roller 507.

The pickup roller 507 is operated by the pickup motor 101 in the c and d directions shown in the figure by the cam mechanism, and the movable table 503 is raised and pushed by the upper surface of the original on the movable table 503 to rise in the c direction and the table rise detection sensor. By 508, the upper limit can be detected.
When the print key is pressed from the main body operation unit 108 and a document feed signal is transmitted from the main body control unit 111 to the ADF control unit 100 via the I / F (interface) 107, the pickup roller 507 is moved to the feed motor 102. The roller is rotationally driven by forward rotation, and several (ideally, one) originals 7 on the original table 502 are picked up. The rotation direction is a direction in which the uppermost document 7 is conveyed to the sheet feeding port.
The paper feeding belt 509 is driven in the paper feeding direction by the normal rotation of the paper feeding motor 102, and the reverse roller 510 is rotationally driven in the direction opposite to the conveying direction by the normal rotation of the paper feeding motor 102, and the uppermost document 7 and its By separating the lower document 7, only the uppermost document 7 can be conveyed.
More specifically, the reverse roller 510 is in contact with the paper feed belt 509 at a predetermined pressure, and is in contact with the paper feed belt 509 or in contact with the paper feed belt 509 via one sheet of the document 7. When the document 7 is rotated and rotated counterclockwise, and two or more sheets of paper 7 enter between the paper feeding belt 509 and the reverse roller 510, the follower force is lower than the torque of the torque limiter. The reverse roller 510 rotates in the clockwise direction, which is the original driving direction, and pushes back the excess original 7, thereby preventing double feeding.

The document 7 separated into one sheet by the action of the paper feed belt 509 and the reverse roller 510 is further fed by the paper feed belt 509, detected by the abutting sensor 511, and further advanced to the pull-out roller 512 stopped. bump into. Thereafter, the sheet is fed by a predetermined distance from the detection of the abutting sensor 511. As a result, the paper feeding motor 102 is stopped while being pressed against the pull-out roller 512 with a predetermined amount of bending, thereby supplying the paper. The driving of the paper belt 509 is stopped. At this time, by rotating the pickup motor 101, the pickup roller 507 is retracted from the upper surface of the document 7 and the document 7 is fed only by the conveying force of the paper feed belt 509, so that the leading edge of the document 7 is the upper and lower rollers of the pull-out roller 512. A pair of nips is entered and tip alignment (skew correction) is performed.
The pull-out roller 512 has a skew correction function and is a roller for conveying the skew-corrected document 7 to the intermediate roller 514 after separation, and is driven by the reverse rotation of the paper feed motor 102. At this time (when the paper feed motor 102 reverses), the pull-out roller 512 and the intermediate roller 14 are driven, but the pickup roller 507 and the paper feed belt 509 are not driven.

A plurality of document width sensors 513 are arranged in the depth direction and detect the size in the width direction perpendicular to the transport direction of the document 7 transported by the pull-out roller 512. Further, the length of the document 7 in the transport direction is detected from the motor pulse by reading the leading end and the rear end of the document 7 with the butting sensor 511.
When the document 7 is conveyed from the registration unit C to the turn unit D by driving the pull-out roller 512 and the intermediate roller 514, the conveyance speed at the registration unit C is set higher than the conveyance speed at the reading conveyance unit E. Thus, the processing time for sending the document 7 to the reading unit is shortened.
When the leading edge of the document is detected by the reading entrance sensor 515, before the leading edge of the document enters the nip between the upper and lower roller pairs of the reading entrance roller 516, deceleration is started in order to make the document transportation speed the same as the scanning transportation speed. Then, the reading motor 103 is driven forward to drive the reading entrance roller 516, the reading exit roller 523, and the CIS exit roller 527.
When the registration sensor 517 detects the leading edge of the document 7, it decelerates over a predetermined conveyance distance, temporarily stops before the reading position 520, and transmits a registration stop signal to the main body control unit 111 via the I / F 107. To do.
Subsequently, when a reading start signal is received from the main body control unit 111, the document 7 that has been stopped in registration is accelerated and conveyed so as to rise to a predetermined conveying speed until the leading edge of the document reaches the reading position. . At the timing when the leading edge of the document 7 detected by the pulse count of the reading motor 103 reaches the reading unit, a gate signal indicating an effective image area on the first surface in the sub-scanning direction is sent to the main body control unit 111. Is sent until the trailing edge of the original comes off.

In the case of single-sided document reading, the document 7 that has passed through the reading conveyance unit E is conveyed to the paper discharge unit G through the second reading unit. At this time, when the leading edge of the document 7 is detected by the paper discharge sensor 524, the paper discharge motor 104 is driven to rotate forward to rotate the paper discharge roller 528 counterclockwise.
In addition, the discharge motor driving speed is reduced immediately before the trailing edge of the document exits the nip of the upper and lower roller pairs of the discharge roller 528 by the pulse count of the discharge motor from the detection of the leading edge of the document 7 by the discharge sensor 524. Control is performed so that the document 7 discharged onto the discharge tray 29 does not jump out.
In the case of double-sided original reading, the discharge sensor 524 detects the leading edge of the original 7 and then the second reading section 25 is reached at the timing when the leading edge of the original 7 reaches the second reading section 25 by the pulse count of the reading motor. On the other hand, a gate signal indicating an effective image area in the sub-scanning direction is transmitted from the control unit 100 of the automatic document feeder (ADF) 5 through the reading unit until the trailing end of the document 7 is removed. The second reading roller 526 serves as a reference white portion for acquiring shading data in the second reading unit as well as suppressing floating of the document 7 in the second reading unit.

4 and 5 are schematic views showing the configuration of the image reading apparatus of the present invention.
Hereinafter, the configuration of the image reading apparatus 4 of the present invention (hereinafter, simply referred to as “reading apparatus”) will be described with reference to the drawings.
An optical unit 401 is present inside the image reading apparatus 4. In the optical unit 401, a first traveling body 404 including a light source 403 and first mirrors 404 a supported at both ends, and both ends are also supported. A second traveling body 405 including a second mirror 405a and a third mirror 405b, and a lens 406 for forming an image of the reflected light of the document 7 on the CCD 407 are provided, and one line sent from the host computer. In response to each image reading request signal, the first traveling body 404 and the second traveling body 405 are configured to sequentially read images while moving along the document 7 at a speed of 2: 1.
The first traveling body 404 moves forward at a constant speed, and the first traveling body 405 travels following the first traveling body 404 at a speed that is 1/2 that of the first traveling body 404. Thereby, the document 7 on the contact glass 402 is optically scanned. The document 7 on the contact glass 402 is illuminated by the light source 403 and the reflected light image is guided to the imaging lens 406 via the first mirror 404a, the second mirror 405a, and the third mirror 405b. An image is formed on a CCD 407 as an image sensor by 406.
The image sensor 407 photoelectrically converts the formed reflected light image of the document 7 into an analog image signal, and reads the document 7. Then, after the reading of the document 7 is completed, the first traveling body 404 and the first traveling body 405 return to the home position.
The analog image signal output from the imaging sensor 407 is converted into a digital image signal by an analog / digital converter, and each image processing (binarization, multi-value conversion, Gradation processing, scaling processing, editing processing, etc.).

A first embodiment of the present invention will be described.
FIG. 6 is a schematic diagram illustrating a configuration of an image reading apparatus / automatic document feeder near a general image reading unit.
7 to 9 are schematic views showing the configuration of the sheet member of the image reading apparatus of the present invention.
The document 7 discharged from the reading entrance roller 516 is conveyed along the guide plate, and delivered to the reading exit roller 523 while being in contact with the upper surface of the contact glass 402.
On the other hand, in the present invention, as shown in FIGS. 7 and 8, a transparent sheet 411 is disposed as a cylindrical sheet member 411 around the contact glass 402, and the transparent sheet 411 includes a driving roller 413 and a driven roller. It is held by a roller 414.
Further, as shown in FIG. 9, the driving roller 413 and the driven roller 414 are respectively held by the driving bearing 413a and the driven bearing 414a, and both the bearings 413a and 414a are pressurized by a spring 415. As a result, the transparent sheet 411 is stretched. A drive transmission component such as a timing pulley 416 is provided on the shaft of the drive roller 413, and power from a motor 418 as a drive source is transmitted via a timing belt 417 or the like.
In the image reading apparatus 4 so far, white reference correction called shading is performed before reading the document 7 and between a plurality of documents 7 when the plurality of documents 7 are continuously conveyed. In this case, the traveling body moves under the white reference plate from the image reading position to read the image on the white reference plate, returns to the image reading position again, and waits for the document 7 to be conveyed to the reading position. is there.

10 and 11 are schematic diagrams for explaining the operation of the image reading apparatus of the present invention.
In the image reading apparatus 4 of the present invention, the transparent sheet 411 is conveyed by the drive source 418 while the shading operation is performed. As a result, when the image is read, the position of the transparent sheet 411 corresponding to the reading position changes every time. Therefore, even if dust adheres during the conveyance of the immediately preceding document 7, it can be taken away from the reading position 520, and dust such as By performing the shading operation in a state without dirt, it is possible to reduce the occurrence of abnormal images having different densities and image accuracy in image formation in the image forming apparatus 1.

FIG. 12 is a perspective view showing a schematic configuration of a drive source for driving the sheet member of the image reading apparatus of the present invention. FIG. 13 is a side view of a schematic configuration of a drive source that drives the sheet member of the image reading apparatus of the present invention.
Next, in the image reading apparatus 4 of the present invention, the drive source 418 for conveying the transparent sheet 411 that is a sheet member is the same as the drive source of the traveling bodies 404 and 405.
In order to convey the transparent sheet 411, a drive source is necessary as described above, but if a dedicated motor or the like is used, the cost increases. On the other hand, the shading operation is performed immediately before reading the document 7, and the document 7 is not read during that time. Therefore, the transparent sheet 411 is conveyed by the motor 418 of the same drive source as the drive sources of the traveling bodies 404 and 405 by interlocking the conveyance operation of the transparent sheet 411 with the shading operation.
For example, the traveling bodies 404 and 405 transmit the power from the motor 418 as a driving source to the traveling body drive shaft 423 via the timing pulley 422, and the drive wire 424 is wound up by the wire pulley provided in the drive shaft 423. The traveling bodies 404 and 405 travel. At this time, the power transmitted to the timing pulley 422 is simultaneously transmitted to the drive pulley 416 of the transparent sheet 411 by the timing belt 425, so that the transparent sheet 411 can be conveyed simultaneously with the shading operation.
During this shading operation, the document 7 is not transported on the contact glass 402. Therefore, by moving the transparent sheet 411 between them, even when dust adheres during transport of the immediately preceding document 7, the reading position 427 is read. Can be taken away from. Further, since there is no dedicated drive source, it can be realized with an inexpensive configuration.

Next, in the image reading apparatus of the present invention, the roller that holds the sheet member is configured to transmit the drive only in one direction.
In the image reading apparatus 4 of the present invention, since the shading operation is a reciprocating operation between the reading position and the white reference plate position, the operation of the transparent sheet 411 is also a reciprocating operation. However, in the case of the reciprocating operation, dust on the transparent sheet 411 once removed may return to the reading position again. Therefore, in the image reading apparatus 4 of the present invention, a one-way clutch is used for a part of a drive train that transports the transparent sheet 411, for example, a timing pulley 416 that transmits power to the drive shaft of the transparent sheet 411, and the like. The power is transmitted only in the direction. By doing so, power is transmitted only in one direction of the reciprocating operation. Therefore, the transparent sheet 411 is conveyed only in one direction even in synchronization with the shading operation. Therefore, it is possible to prevent the dust on the transparent sheet 411 once removed from returning to the reading position again, and thus it is possible to reduce abnormal images due to dust.

Next, in the image reading apparatus 4 of the present invention, the sheet member 411 includes a cleaning mechanism 426 on the upstream side of the reading position with respect to the conveyance direction of the sheet member 411, and the sheet member 411 is conveyed once. The amount is larger than the distance between the cleaning mechanism 426 and the reading position 427.
FIG. 14 is a schematic diagram illustrating driving of the sheet member of the image reading apparatus of the present invention.
In the present invention, a cleaning mechanism 86 is provided upstream of the reading position 87 with respect to the transport direction of the transparent sheet 411 as a sheet member, and the transport amount of the transparent sheet 411 by one operation is determined between the cleaning mechanism and the reading position. It is larger than the distance. In this way, when the transparent sheet 411 is conveyed, the portion that has passed through the cleaning mechanism always becomes the reading position, so that the next original 7 can be read reliably at the portion from which dust has been removed. For this reason, it is possible to reduce abnormal images due to dust.

Next, in the image reading device 4 of the present invention, the diameters of both the driving roller 413 and the driven roller 414 that hold the sheet member 411 are larger than the thickness of the contact glass 402.
FIG. 15 is a schematic diagram illustrating the diameter of the roller that holds the sheet member and the thickness of the contact glass in the image reading apparatus of the present invention.
In the image reading apparatus 4 of the present invention, the diameter 88 of both the driving roller 413 and the driven roller 414 that hold the transparent sheet 411 is made larger than the thickness 89 of the contact glass 402, and the contact glass 402 and the transparent sheet 411 are formed. The configuration is such that it does not contact. By doing so, the edge portion of the contact glass 402 and the transparent sheet 411 are not in contact with each other when the transparent sheet 411 is conveyed, and the transparent sheet 411 can be prevented from being damaged. Even when the transparent sheet 411 is scratched, an abnormal image may be formed as in the case of dust. With this configuration, the abnormal image can be reduced.

Next, in the image reading apparatus 4 of the present invention, the transmittance of the sheet member 411 has a characteristic of cutting the longer wavelength side from the near infrared region.
In the image reading apparatus 4 of the present invention, the transmittance of the transparent sheet 411 is set so that the longer wavelength side is cut from the near infrared region. The light source 403 generally used in the image reading device 4 has light that has a minute wavelength but a wavelength longer than the near infrared region, and the photographing sensor 407 such as a CCD has sensitivity in the above wavelength band. In the original 7 having the reflectance of the area, there is a case where the desired color reproduction cannot be obtained. On the other hand, since this problem is solved by adopting this configuration, a better image can be obtained.

Next, in the image reading apparatus of the present invention, this can be used in preparation for the image forming apparatus.
FIG. 16 is a schematic diagram showing a configuration of an image forming apparatus incorporating the image reading apparatus of the present invention.
The image forming apparatus 1 shown in FIG. 16 is a system in which process cartridges serving as the image forming units 10 are arranged in parallel, the images are once superimposed on the intermediate transfer belt 61, and the images are collectively transferred to the recording member 6. Further, the image forming apparatus 1 has process cartridges serving as the image forming unit 10 arranged in parallel, and the toner image is sequentially transferred onto the conveying belt 66 while the recording member 6 is conveyed.

As shown in FIG. 16, the image forming apparatus 1 includes an automatic document feeder (ADF) 5 that automatically feeds a placed document 7 from above, and a scanner (reading device) 4 that reads the document 7. An image forming unit 3 for forming a toner image, and a recording member 6 such as a recording sheet are provided below the image forming unit 3 and a paper supply unit 2 for supplying the recording member 6 is disposed.
The image forming apparatus 1 has an image forming unit 3 disposed at the center thereof. In the image forming unit 3, there are four image forming units 10 corresponding to yellow (Y), magenta (M), cyan (C), and black (K) color toners at approximately the center of the inside. They are arranged in a tandem shape arranged in parallel in the horizontal direction.
Above the four image forming units 10Y, 10C, 10M, and 10K, an exposure device 12 that exposes the surface of each charged electrostatic latent image carrier 11 based on image data of each color and forms a latent image. Is provided. Below the four image forming units 10Y, 10C, 10M, and 10K, endless belts made of a heat-resistant material such as polyimide and polyamide and adjusted to a medium resistance are provided on rollers 651, 652, and 653. A transfer device 60 including an intermediate transfer belt 61 that is supported by being wound and rotated is disposed.
Since any image forming unit 10 has the same configuration, in this figure, the display of Y, C, M, and K is omitted if it is not related to the color distinction. Each of the image forming units 10Y, 10C, 10M, and 10K has electrostatic latent image carriers 11Y, 11C, 11M, and 11K, and around each electrostatic latent image carrier 11, the electrostatic latent image carrier 11 is provided. A charging device 20 for applying a charge to the surface, a developing device 30 for developing a latent image formed on the surface of the electrostatic latent image carrier 11 with each color toner to form a toner image, and the surface of the electrostatic latent image carrier 11 are not shown. A lubricant applicator for applying the lubricant and a cleaning device 40 having a cleaning blade for cleaning the surface of the electrostatic latent image carrier 11 after the transfer of the toner image are arranged. Thus, one image forming unit 10 is formed.

The electrostatic latent image carrier 11 is made of a metal such as amorofus silicone or selenium, or an organic system. The organic electrostatic latent image carrier 11 has a resin layer in which a filler is dispersed, a photosensitive layer having a charge generation layer and a charge transport layer on a conductive support, and a protective layer in which a filler is dispersed on the surface.
The photosensitive layer may be a single-layered photosensitive layer containing a charge generation material and a charge transport material, but a laminated type composed of a charge generation layer and a charge transport layer is excellent in sensitivity and durability.
In the charge generation layer, a pigment having charge generation ability is dispersed in a suitable solvent together with a binder resin as necessary using a ball mill, an attritor, a sand mill, an ultrasonic wave, etc., and this is coated on a conductive support. It is formed by drying. As binder resin, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N-vinylcarbazole, polyacrylamide, polyvinyl benzal, polyester Phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone and the like. The amount of the binder resin is suitably 0 to 500 parts by mass, preferably 10 to 300 parts by mass with respect to 100 parts by mass of the charge generating material.
The charge transport layer can be formed by dissolving or dispersing the charge transport material and the binder resin in a suitable solvent, and applying and drying the solution on the charge generation layer. Charge transport materials include hole transport materials and electron transport materials. As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol Examples thereof include thermoplastic or thermosetting resins such as resins and alkyd resins.
In addition, a protective layer may be provided on the photosensitive layer. By providing the protective layer and improving the durability, the electrostatic latent image carrier 11 having high sensitivity and no abnormal defects of the present invention can be used effectively.
Materials used for the protective layer include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, Examples thereof include resins such as polybutylene terephthalate, polycarbonate, polyarylate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyvinylidene chloride, and epoxy resin. Of these, polycarbonate or polyarylate can be most preferably used. Other protective layers include fluorine resins such as polytetrafluoroethylene, silicone resins, and inorganic fillers such as titanium oxide, tin oxide, potassium titanate, and silica for the purpose of improving wear resistance. What disperse | distributed the filler etc. can be added. The filler concentration in the protective layer varies depending on the type of filler used and also on the electrophotographic process conditions using the electrostatic latent image carrier 11, but the ratio of filler to the total solid content on the outermost layer side of the protective layer 9 is 5 The mass% or more, preferably 10 mass% or more, 50 mass% or less, preferably about 30 mass% or less is good.

The charging device 20 includes a charging roller 21 configured by covering a conductive core bar with a medium-resistance elastic layer as a charging member. The charging roller is connected to a power source (not shown), and is applied with a predetermined direct voltage (DC) and / or alternating voltage (AC). The charging roller 21 that discharges ions uses an elastic resin roller as a material. In addition, the charging roller 21 may contain an inorganic conductive material such as carbon black or an ionic conductive material in order to adjust electric resistance.
The charging roller 21 is disposed with a small gap with respect to the electrostatic latent image carrier 11. For example, the surface of the spacer member is brought into contact with the surface of the electrostatic latent image carrier 11 by winding a spacer member having a certain thickness around the non-image forming regions at both ends of the charging roller 21. This can be set. Further, the charging roller 21 may be brought into contact without being brought close to the electrostatic latent image carrier 11. The electrostatic latent image carrier 11 can be charged by discharging at a portion that is in the shape of a roller and is close to the electrostatic latent image carrier 11. Further, by making them close and not in contact with each other, it is possible to suppress the occurrence of contamination due to the transfer residual toner of the charging roller 21. In addition, the charging roller 21 is provided with a charging cleaner roller (not shown) that contacts the surface of the charging roller 21 for cleaning.
The developing device 30 uses a two-component developer having a magnetic carrier and toner. And in order to develop the electrostatic latent image carrier 11 which has a latent image, it is provided in the position which opposes.
Further, although not shown, the developing device 30 includes a developer carrier 31 provided with a magnetic field generating means. Below the developer carrying member, a stirring / conveying screw 34 having a mechanism for mixing toner introduced from a toner bottle (not shown) with the developer and pumping the toner to the developer carrying member 31 while stirring is provided. . The two-component developer composed of the toner and the magnetic carrier conveyed by the developer carrier 31 is regulated to a predetermined developer layer thickness by the pumping amount regulating member 35 and is carried on the developer carrier 31. The developer carrying member 31 carries and conveys the developer while moving in the same direction at a position facing the electrostatic latent image carrying member 11 and supplies the toner to the electrostatic latent image carrying member 11. In addition, toner cartridges for each color in which unused toner is stored are detachably stored in the space above the electrostatic latent image carrier 11. Toner is supplied as necessary to each developing device 30 by toner conveying means such as a mono pump or air pump (not shown). A toner cartridge for black toner that is highly consumed can be set to have a particularly large capacity.
More details will be described later.

The cleaning device 40 includes a cleaning blade and a holder for holding the blade, and removes residual toner from the electrostatic latent image carrier 11 by pressing the blade member against the electrostatic latent image carrier 11. To do. In addition, the cleaning blade includes a mechanism for contacting / separating the electrostatic latent image carrier 11 and can be arbitrarily contacted / separated by the control unit of the image forming apparatus 1. The cleaning blade is brought into contact with the electrostatic latent image carrier 11 in a counter manner, whereby toner remaining on the electrostatic latent image carrier 11, talc of recording members adhering as dirt, kaolin, calcium carbonate, etc. The additive is removed from the electrostatic latent image carrier 11 and cleaned. The removed toner or the like is conveyed and stored in a waste toner container (not shown) by a waste toner collection coil (not shown).
The toner that has been cleaned by the cleaning device 40 and removed from the electrostatic latent image carrier 11 is collected by a serviceman or the like by a toner conveying member, or is carried to a developing device or the like as recycled toner and used for development. .

The transfer device 60 includes an intermediate transfer belt 61 on which toner images are stacked, a primary transfer roller 62 that transfers and stacks the toner images on the electrostatic latent image carrier 11 to the intermediate transfer belt 61, and the stacked toner images on a recording member. And a secondary transfer roller 63 for transferring the toner to the toner image. Further, the transfer device 60 is a portion facing the secondary transfer roller 63, and is provided inside the intermediate transfer belt 61 so that a support roller 653 serving as a facing member faces.
A primary transfer roller that primarily transfers a toner image formed on the electrostatic latent image carrier 11 onto the intermediate transfer belt 61 at a position facing each electrostatic latent image carrier 11 with the intermediate transfer belt 61 interposed therebetween. 62 are arranged. The primary transfer roller 62 is connected to a power source (not shown), and is applied with a predetermined direct current voltage (DC) and / or alternating current voltage (AC). The polarity of the voltage to be applied is opposite to the polarity of the charge of the toner, and the primary transfer is performed by drawing and moving from the electrostatic latent image carrier 11 to the intermediate transfer belt 61 side. The primary transfer roller 62 is preferably semiconductive by containing an inorganic conductive material such as carbon black and an ionic conductive material in order to adjust electric resistance. Even if the resistance value of the primary transfer roller 62 is different, the transfer efficiency is hardly changed. However, if the image area ratio is different, the transfer efficiency is greatly different, so that the transfer efficiency cannot be stably maintained. This is because the current flows preferentially to the portion where the toner is not present in the transfer nip portion. As a result, when the image area ratio is small, the transfer voltage value becomes low and the electric field necessary for transfer cannot be obtained sufficiently. is there. In particular, when the resistance value of the primary transfer roller 62 is low, the influence of the resistance value of the toner interposed in the transfer portion becomes large. When constant current control is employed in this way, it is desirable to use a primary transfer roller 62 having a high resistance value. However, if the resistance value exceeds 5 × 10 ⁸ Ω, a toner image is formed due to current leakage. The risk of disturbance is increased. Therefore, it is preferable to use a primary transfer roller having a resistance value in the range of 1 × 10 ⁵ Ω to 5 × 10 ⁸ Ω. The phenomenon that the current flows preferentially to the portion where the toner does not intervene is not only due to the above-described toner resistance, but also the primary transfer voltage applied to the metal core provided at the center of the primary transfer roller 62 and the electrostatic latent voltage. This is also because the potential difference from the image carrier 11 is larger at the portion where the toner is not developed than at the portion where the toner is developed, and thus the transfer current tends to flow toward the larger potential difference. This is because the toner image is the same as the charging polarity of the electrostatic latent image carrier 11, and the toner is developed at a place where the electrostatic potential is removed by receiving the image exposure of the electrostatic latent image carrier 11. This occurs when the image forming apparatus 1 forms a toner image on the electrostatic latent image carrier 11. The photosensitive member potential is high where the toner image is not formed and the photosensitive member potential is low where the toner image is formed, but the transfer potential is opposite to the photosensitive member potential, so the primary transfer voltage and the photosensitive member potential The difference is larger at the portion where the toner is not developed than at the portion where the toner is developed. In this case, the resistance value of the primary transfer roller 62 is desirably in the range of 5 × 10 ⁷ Ω to 5 × 10 ⁸ Ω.

The toner image laminated on the intermediate transfer belt 61 is secondarily transferred to the recording member by the secondary transfer roller 63. Similar to the primary transfer roller 62, the secondary transfer roller 63 is connected to a power source (not shown) and is applied with a predetermined DC voltage (DC) and / or AC voltage (AC). The polarity of the voltage to be applied is opposite to the polarity of the charge of the toner, and the secondary transfer is performed by drawing the intermediate transfer belt 61 toward the recording member that has been conveyed.
The secondary transfer roller 63 includes a cylindrical metal core made of metal, an elastic layer formed on the outer peripheral surface of the metal core, and a surface layer made of a resin material formed on the outer peripheral surface of the elastic layer. Has been.
The metal constituting the metal core is not particularly limited. For example, a metal material such as stainless steel or aluminum is used. Generally, a rubber material is used for the elastic layer formed on the cored bar to form a rubber layer 65b. This is because the secondary transfer roller 63 is required to have an elastic function in order to deform the secondary transfer roller 63 and secure a secondary transfer nip portion, and the JIS-A hardness is 70 [ °] The following is desirable.
In addition, since the cleaning blade 22 is used as a cleaning means for the secondary transfer roller 63, if the elastic layer is too soft, the contact state of the cleaning blade 22 becomes unstable and an appropriate cleaning angle cannot be obtained. Therefore, the hardness of the elastic layer is preferably JIS-A 40 [°] or more.
In addition, since the secondary transfer roller 63 cannot perform the function of transferring a toner image to a recording medium when an insulator is used, it is preferably a foamed resin agent having a conductive function and a thickness of 2 mm to 10 mm. As a material imparting a conductive function, EPDM or Si rubber in which carbon black is dispersed, NBR having an ionic conductive function, urethane rubber, or the like may be used.
Since most of the foamed resin agents used for the elastic layer have high chemical affinity for the toner and a large friction coefficient, the functions required for the surface layer with which the cleaning blade 22 is in contact are low friction coefficient, toner separation. Since the moldability is required, the surface layer of the secondary transfer roller 63 is used by adjusting the resistance by adding a resistance control material to the fluororesin resin.
Further, since the secondary transfer roller 63 rotates in contact with the intermediate transfer belt 61, if a minute linear velocity difference occurs between the intermediate transfer belt 61 and the secondary transfer roller 63, the intermediate transfer belt 61. It will affect the driving of the. Therefore, since the sliding property with the intermediate transfer belt 61 is required for the surface layer of the secondary transfer roller 63, it is desirable to set the friction coefficient of the outermost surface layer to be 0.4 or less.
The intermediate transfer belt 61 is provided with an intermediate transfer belt cleaning device 64 that cleans the surface of the intermediate transfer belt 61 after the secondary transfer.
In addition, the support roller 653 includes a mechanism for contacting / separating with the intermediate transfer belt 61 and can be arbitrarily contacted / separated by the control unit of the main body of the image forming apparatus 1.

Further, the image forming apparatus 1 is provided with a lubricant applying device 45 that applies a lubricant to the intermediate transfer belt 61. The lubricant application device 45 includes a solid lubricant contained in a fixed case, a brush roller that contacts the solid lubricant, scrapes the lubricant, and is applied to the intermediate transfer belt 61 and a lubricant applied by the brush roller. A lubricant application blade for leveling is provided. The solid lubricant is formed in a rectangular parallelepiped shape and is urged toward the brush roller by a pressure spring. The solid lubricant is scraped off and consumed by the brush roller, and the thickness of the solid lubricant decreases with time. However, since the solid lubricant is pressurized by the pressure spring, the solid lubricant is always in contact with the brush roller. The brush roller applies the lubricant scraped off while rotating to the surface of the intermediate transfer belt 61.
Note that a lubricant application device having a similar function may be provided for the electrostatic latent image carrier 11.
In this embodiment, a lubricant application blade (not shown) as a lubricant leveling means is brought into contact with the surface of the intermediate transfer belt 61 on the downstream side in the moving direction with respect to the lubricant application position by the brush roller. The lubricant application blade is made of rubber which is an elastic body, has a function as a cleaning means, and is in contact with the moving direction of the intermediate transfer belt 61 in the counter direction. As the solid lubricant, a dry solid hydrophobic lubricant can be used. In addition to zinc stearate, metal compounds having fatty acid groups such as stearic acid, oleic acid, and palmitic acid can also be used. . Further, waxes such as candelilla wax, carnauba wax, rice wax, wax, ooba oil, beeswax, and lanolin can be used.

The intermediate transfer belt 61 is composed of single layer or multiple layers of PVDF (vinylidene fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), PI (polyimide), PC (polycarbonate), etc., and is made of conductive material such as carbon black. The volume resistivity is adjusted to be in the range of 10 ⁸ to 10 ¹² Ωcm, and the surface resistivity is adjusted to be in the range of 10 ⁹ to 10 ¹³ Ωcm. If necessary, a release layer may be coated on the surface of the intermediate transfer belt 61. As materials used for the coating, ETFE (ethylene-tetrafluoroethylene copolymer),
PTFE (polytetrafluoroethylene), PVDF (vinylidene fluoride), PEA (perfluoroalkoxy fluororesin), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PVF (vinyl fluoride), etc. Although a fluororesin can be used, it is not limited to this.
The method of manufacturing the intermediate transfer belt 61 includes a casting method, a centrifugal molding method, and the like, and the surface thereof may be polished as necessary.
If the volume resistivity of the intermediate transfer belt 61 exceeds the above-described range, the bias necessary for transfer increases, which increases the power supply cost, which is not preferable. Further, since the charging potential of the intermediate transfer belt 61 becomes high and the self-discharge becomes difficult in the transfer process, the transfer paper peeling process, etc., it is necessary to provide a static eliminating means. Also, if the volume resistivity and surface resistivity are below the above ranges, the charge potential decays faster, which is advantageous for static elimination by self-discharge, but toner scattering occurs because the current during transfer flows in the surface direction. End up. Therefore, the volume resistivity and the surface resistivity of the intermediate transfer belt 61 in the present invention must be within the above ranges.
The volume resistivity and the surface resistivity were measured by connecting an HRS probe (inner electrode diameter 5.9 mm, ring electrode inner diameter 11 mm) to a high resistivity meter (manufactured by Mitsubishi Chemical Corporation: Hiresta IP), and the intermediate transfer belt 61. The measured value 10 seconds after applying the voltage of 100V (surface resistivity is 500V) to the front and back of the was used.

  On the left side of the transfer device 60 is provided a fixing device 70 that semipermanently fixes the toner image on the recording member 6 to the recording member 6. Although not shown, the fixing device 70 is mainly composed of a fixing roller 71 having a halogen heater inside, and a pressure roller 72 disposed so as to be opposed to and pressed against the fixing roller 71. The fixing device 70 is controlled by control means (not shown) so as to control fixing conditions based on full-color and monochrome images, single-sided or double-sided, and optimal fixing conditions depending on the type of the recording member 6.

When the double-sided copy mode is selected, the recording member 6 having an image fixed on one side is conveyed to the recording member reversing device 89 side by the switching claw 851, and a plurality of predetermined arrangements are provided in the reversing path 87. By reciprocating the reversal conveyance path 87 formed in advance by a conveyance roller or a guide member (not shown), the recording member surface 9 is turned upside down, and then switched again by the switching claw 852 to perform image formation. The transport path is returned to the registration roller 84, transported along the transport path, and transported to the registration roller 84 again. Here, the position and direction of the recording member 6 are aligned again and sent to the registration roller 84. Therefore, even when an image is formed on the back surface of the recording member 6, the front and back images of the recording member 6 can be aligned.
Further, after being guided to the transfer device 60 and this time transferring and fixing the image on the back surface of the recording member 6, the image is finally discharged onto the discharge tray 86 by the discharge roller 85.
At this time, when the number of the recording members 6 is one, the surface of the recording member 6 is turned upside down and then passes through the re-conveying path 87 of the recording member reversing / conveying device 89 and is again formed by the registration rollers 84. After the image is formed by the unit 10, the image is formed on the recording member 6 by the transfer roller 63. This time, after the image is transferred and fixed on the back surface of the recording member 6, it is finally discharged onto the paper discharge tray 86 by the paper discharge roller 48.
When there are a plurality of recording members 6, the recording member reversal storage device 88 in the recording member reversal conveyance device 89 stores one end of the recording member 6 having a set number of toner images on one side, and then from there. The paper is fed by the paper feed roller 82, separated one by one by the separation roller 81, and waits for the image forming unit 10 to form an image again by the registration roller 84, and an image is formed on the recording member 6. Is done. This time, after the image is transferred and fixed on the back surface of the recording member 6, it is finally discharged onto the discharge tray 86 by the discharge roller 85.
The process cartridge 10 that is an image forming unit is provided with a charging device 20, a developing device 30, a cleaning device 40, and a lubricant application device 45 with the electrostatic latent image carrier 11 as a center. The process cartridge 10 integrally supports at least the electrostatic latent image carrier 11 and the developing device 30 and is detachable from the image forming apparatus 1.

Next, an image forming operation will be described.
In the image forming operation, first, it is difficult to stack the originals on the original table 502 in advance, and it is difficult to stack them. In particular, when using originals having various sizes, the image forming apparatus It is necessary to input the size of the original in 1, and the complicated work is forced. However, the automatic document feeder (ADF) 5 according to the present invention is used for the document table 502 so that the user can automatically place the document on the document table 502 and automatically regulate and store the document at a predetermined position. Then, the document size is detected simultaneously with the loading, and the image forming apparatus 1 can be used remarkably easily and conveniently.
Further, since the original can be stored in a predetermined position and conveyed toward the reading device 4, paper jams during the conveyance of the automatic original conveyance device 5 can be reduced. Furthermore, by suppressing the skew of the document in the automatic document feeder 5, the document can be placed and read on the contact glass 402 with high accuracy, and as a result, a high-quality image with high accuracy can be obtained.
In the reading device 4, as shown in FIG. 16, after moving on the contact glass 402, the document 7 is set on the other contact glass 402. At this time, it is possible to perform a shading operation before setting the document 7. By moving the transparent sheet 411 by this shading operation, even if dust adheres during the conveyance of the immediately preceding document 7, it can be taken away from the reading position 427.
Immediately after this shading operation, the light source 403 is caused to emit light, and the first traveling body 404 and the second traveling body 405 travel. Then, the first traveling body 404 emits light from the light source 403 and further reflects the reflected light from the document surface toward the second traveling body 405 and reflects by the mirror of the second traveling body 405 to form the imaging optical. The document is read through the lens 304 into an image sensor 407 composed of a CCD.

Then, an electrostatic latent image for each color formed on the surface of each photoconductor 11 is formed on the surface of each photoconductor 11 by the laser beam of the exposure device 12 with respect to the photoconductor 11 having the load electrode property as individual image forming means. Next, the developing device 30 develops the toner of a predetermined color having the same polarity (negative polarity) as the charged polarity of the photoconductor 11 and performs reversal development to become a visible image. At this time, the endless intermediate transfer belt 61 is supported by a plurality of rollers 651 to 653 and provided on the top of the photoreceptors 11Y, 11C, 11M, and 11K, and the photoreceptors 11Y, 11C, 11M, and 11K. It is stretched and arranged so that a part after the development process is in contact with the vehicle. The toner images formed on the photoreceptors 11Y, 11C, 11M, and 11K are transferred onto the intermediate transfer belt 61 by the primary transfer rollers 62Y, 62C, 62M, and 62K, and the toner images are transferred to the intermediate transfer belt 61. Are superimposed to form an unfixed image. A belt cleaning device 64 is provided on the outer peripheral portion of the intermediate transfer belt 61 at a position facing the cleaning backup roller 641. The belt cleaning device 64 wipes off unnecessary toner remaining on the surface of the intermediate transfer belt 61 and foreign matters such as paper dust. Further, a secondary transfer roller 63 is provided on the outer periphery of the intermediate transfer belt 61 at a position facing the support roller 653.
At this time, a paper feeding device 80 including a paper feeding cassette 81 in which the recording member 6 can be supplied is provided below the image forming apparatus 1. Only one sheet of the recording member 6 is reliably sent from the paper feed cassette 81 to the conveyance guide device 90 by the conveyance roller 82. Here, the positions of the recording member 6 in the width direction and the conveyance direction are controlled to the correct positions. Further, it is sent to a registration roller 84 on the upstream side in the transport direction.
Next, by applying a bias to the secondary transfer roller 63 while passing the recording member 6 between the intermediate transfer belt 61 and the secondary transfer roller 63, the toner image carried by the intermediate transfer belt 61 is applied to the recording member 6. Transcribed. When the recording member 6 is conveyed in a controlled position and direction, a high-quality transfer image with little transferred deviation or the like is obtained on the recording member 6. The polarity of the transfer voltage applied to the secondary transfer roller 63 is a positive polarity opposite to the polarity of the toner. These members related to the intermediate transfer belt 61 are integrally configured as a transfer device 60 together with the intermediate transfer belt 61, and can be attached to and detached from the image forming apparatus 1.
Further, the recording member 6 that has passed the secondary transfer roller 63 is conveyed to a fixing device 70 provided downstream in the conveying direction. The recording member 6 after fixing is discharged and stacked by a discharge roller 85 on a discharge tray 86 provided outside the image forming apparatus 1.
Therefore, a high-quality image is finally obtained on the recording member 6.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Paper feed part 3 Image forming part 4 Image reading apparatus (scanner part)
401 Optical unit 402/521 Contact glass 403 Light source / lamp 404 First traveling body 404a First mirror 405 Second traveling body 405a Second mirror 405b Third mirror 406 Lens 407 CCD
411 Transparent sheet 412/522 Feed guide 413 Drive roller 413a Drive bearing 414 Driven roller 414a Driven bearing 415 Spring 416 Timing pulley 417 Timing belt 418 Motor 422 Timing pulley 423 Traveling body drive shaft 424 Drive wire 427 Cleaning mechanism 426 Cleaning belt 426 520 Reading position 428 Roller diameter 429 Contact glass thickness 5 Automatic document feeder (ADF)
501 Document bundle 502 Document table 503 Movable document table 504 Set filler 505 Set sensor 507 Pickup roller 508 Table lift detection sensor 509 Feed belt 510 Reverse roller 511 Abutting sensor 512 Pull-out roller 513 Document width sensor 514 Intermediate roller 515 Reading entrance sensor 516 Reading entrance roller 517 Registration sensor 523 Reading exit roller 524 Paper discharge sensor 525 Second reading unit 526 Second reading roller 527 CIS exit roller 528 Paper discharge roller 529 Paper discharge tray 530 Document length detection sensor 531 Document length detection sensor 6 Recording Member 7 Document 10 Image forming unit (process cartridge)
DESCRIPTION OF SYMBOLS 11 Photoconductor 12 Exposure apparatus 13 Static elimination apparatus 20 Charging apparatus 21 Charging roller 30 Developing apparatus 40 Cleaning apparatus 45 Lubricant coating apparatus 60 Transfer apparatus 61 Intermediate transfer belt 62 Primary transfer roller 63 Secondary transfer roller 64 Belt cleaning apparatus 641 Cleaning backup roller 642 Rotating member 65 Roller 651 Driven roller 652 Drive roller 653 Support / tension roller 66 Conveyor belt 70 Fixing device 80 Paper feed device 81 Paper feed cassette 811 Separating roller 812 Paper feed roller 82 Transport path 83a, 83b, 83c, 83d Transport roller 84 Registration roller 85 Paper discharge roller 851, 852 Switching claw 86 Paper discharge tray 87, 871, 872 Reverse conveyance path 88 Recording member storage device 89 Recording member reverse conveyance device 100 Controller 101 105 reading driver 101 pickup motor 102 feed motor 103 motor 104 discharge motor 105 the bottom plate lifting motor 107 I / F
108 Main unit operation unit 111 Main unit control unit 200 Light source unit 201 Sensor chip 202 Operational amplifier 203 A / D conversion element 204 Image processing unit 205 Frame memory 206 Output control circuit 207 I / F circuit

JP2004-221727 Japanese Patent No. 3832483

Claims (8)

In an image reading apparatus that irradiates light on a document conveyed on a contact glass at a constant speed, forms an image with a lens through a mirror included in a traveling body, and reads the image with a sensor.
The contact glass is covered with a transparent cylindrical sheet member, and the sheet member moves during a shading operation. The image reading apparatus according to claim 1,
The image reading device is linked to an automatic document conveying device that separates documents one by one with the traveling body fixed and conveys the document at a constant speed onto the contact glass of the image reading unit. An image reading apparatus. The image reading apparatus according to claim 2,
An image reading apparatus, wherein a driving source for conveying the sheet member is the same as a driving source of the traveling body. The image reading apparatus according to claim 3.
The roller that holds the sheet member is configured to transmit driving only in one direction. The image reading apparatus according to claim 4.
The sheet member includes a cleaning mechanism upstream of the reading position with respect to the conveying direction of the sheet member, and a single conveyance amount of the sheet member is larger than a distance between the cleaning mechanism and the reading position. An image reading apparatus characterized by being large. The image reading apparatus according to claim 5.
An image reading apparatus, wherein a diameter of a roller for holding the sheet member is larger than a thickness of the contact glass. The image reading apparatus according to claim 6.
The transmittance of the sheet member has a characteristic of cutting a longer wavelength side from the near infrared region. An image carrier for carrying an electrostatic latent image;
A charging device disposed in contact with or in proximity to the image carrier to charge the surface of the image carrier;
An exposure device for exposing the surface of the image carrier and writing an electrostatic latent image;
A developing device that visualizes the latent image formed on the surface of the image carrier with toner;
A transfer device for transferring a visible image on the surface of the image carrier to a recording member;
A cleaning device disposed downstream of the transfer device for cleaning the toner on the surface of the image carrier;
An image forming apparatus comprising: a fixing device that melts and fixes the toner on the recording member.
The image forming apparatus using the image reading apparatus according to claim 1.

Images