JP6829836B2 - Image reader and image forming device - Google Patents

Description

The present invention relates to an image reader and an image forming apparatus.

Conventionally, an image reading device including a reading means for reading an image of a document as an object to be transported and a contact glass as a translucent member arranged between a transport path for transporting the document and the reading means has been known. Has been done. In such an image reading device, when the document passes through the reading position of the scanning means while being guided by the contact glass, dust adhering to the document adheres to the contact glass, and vertical streaks occur in the scanned image due to the influence of the dust. It is known to do.

According to Patent Document 1, as the image reading device, it is determined based on the scanned image whether or not dust is attached to the contact glass, and when it is determined that dust is attached, a transporting means for transporting the document. There is a description that automatically opens the ADF to encourage the user to clean the contact glass.

However, the image reading device described in Patent Document 1 has a problem that the user has to take time to clean the contact glass.

In order to solve the above problems, the present invention provides a reading means for reading an image of an object to be transported and a translucent member arranged between the transport path to which the object is transported and the reading means. In the image reading device provided, the evacuation means for retracting the translucent member from between the conveying path and the reading means, and the control means for controlling the retracting means based on the conveying position of the object. When the tip of the object is positioned at a transport position held by a member on the downstream side provided on the downstream side in the transport direction with respect to the light-transmitting member, the control means can move the light-transmitting member. It is characterized in that the retracting means is controlled so as to retract from between the transport path and the reading means .

According to the present invention, it is possible to suppress the adhesion of dust to the translucent member while suppressing the occurrence of transport jam of the object.

The schematic block diagram which shows the copying machine which concerns on embodiment. A partially enlarged configuration diagram showing an enlarged part of the internal configuration of the image forming portion in the copier. A partially enlarged view showing a part of a tandem part composed of four process units in the image forming part. The perspective view which shows the scanner and ADF of the copier. An enlarged configuration diagram showing the main configuration of the ADF together with the upper part of the scanner. The block diagram which shows a part of the electric circuit of the copying machine. The block diagram which shows the main part of the electric circuit of a close contact type image sensor. The figure explaining the transport | transport of the document MS of the 1st scanning transport section. The figure which shows the state which the 1st contact glass was positioned at the retracted position. FIG. 5 is a schematic view showing an example in which a suction fan for sucking dust adhering to the document facing surface of the first contact glass located at the retracted position is provided. The figure which shows another example which provided the suction fan which sucks the dust adhering to the document facing surface of the 1st contact glass located at the retracted position. The flow chart which shows an example of the retracting operation of the 1st contact glass.

Hereinafter, embodiments in which the present invention is applied to an electrophotographic copying machine (hereinafter, simply referred to as a copying machine) will be described.
First, the basic configuration of the copying machine according to the embodiment will be described. FIG. 1 is a schematic configuration diagram showing a copying machine according to an embodiment. This copier includes an image forming unit 1, a blank paper supply device 40, and a document reading device 50. The document reading device 50 includes a scanner 150 fixed on the image forming unit 1 and an ADF 51 as a document transporting device supported by the scanner 150.

The blank paper supply device 40 separates the two paper feed cassettes 42 arranged in multiple stages in the paper bank 41, the delivery roller 43 for feeding the transfer paper from the paper feed cassettes, and the paper feed path 44. It has a separation roller 45 and the like to be supplied. It also has a plurality of transfer rollers 47 and the like that transfer the transfer paper to the paper feed path 37 of the image forming unit 1. Then, the transfer paper in the paper feed cassette is fed into the paper feed path 37 in the image forming unit 1.

FIG. 2 is a partially enlarged configuration diagram showing a part of the internal configuration of the image forming portion in an enlarged manner. The image forming unit 1 as an image forming means includes an optical writing device 2, four process units 3K, Y, M, C, and a transfer unit 24 for forming a toner image of K, Y, M, and C colors. .. It also includes a paper transport unit 28, a resist roller pair 33, a fixing device 34, a switchback device 36, a paper feed path 37, and the like. Then, a light source such as a laser diode or an LED arranged in the optical writing device 2 is driven to irradiate the laser light L toward the four drum-shaped photoconductors 4K, Y, M, and C. By this irradiation, an electrostatic latent image is formed on the surface of the photoconductors 4K, Y, M, and C, and this latent image is developed into a toner image via a predetermined development process. The subscripts K, Y, M, and C added after the code indicate that the specifications are for black, yellow, magenta, and cyan.

The process units 3K, Y, M, and C support the photoconductor and various devices arranged around the photoconductor as one unit on a common support, respectively, with respect to the image forming unit 1 main body. It is removable. Taking the black process unit 3K as an example, it has a photoconductor 4K and a developing device 6K for developing an electrostatic latent image formed on the surface of the photoconductor into a black toner image. It also has a drum cleaning device 15 for cleaning the transfer residual toner adhering to the surface of the photoconductor 4K after passing through the primary transfer nip for K, which will be described later. This copying machine has a so-called tandem type configuration in which four process units 3K, Y, M, and C are arranged to face the intermediate transfer belt 25, which will be described later, so as to be arranged along the endless movement direction. There is.

FIG. 3 is a partially enlarged view showing a part of a tandem portion composed of four process units 3K, Y, M, and C. The four process units 3K, Y, M, and C have almost the same configuration except that the colors of the toners used are different. Therefore, in the figure, K, Y, M, and C attached to each reference numeral. The subscript is omitted. As shown in the figure, the process unit 3 has a charging device 23, a developing device 6, a drum cleaning device 15, a static elimination lamp 22, and the like around the photoconductor 4.

As the photoconductor 4, a drum-shaped one in which a photosensitive layer is formed by applying a photosensitive organic photosensitive material to a raw tube such as aluminum is used. However, an endless belt-shaped one may be used.

The developing apparatus 6 develops a latent image using a two-component developer containing a magnetic carrier and a non-magnetic toner. To transfer the toner in the two-component developer carried on the developing sleeve 12 and the stirring unit 7 that conveys the two-component developer housed inside while stirring and supplies the developing sleeve 12 to the photoconductor 4. It has a developing unit 11 of the above.

The stirring unit 7 is provided at a position lower than that of the developing unit 11, and is provided on two transport screws 8 arranged in parallel with each other, a partition plate provided between the screws, and a bottom surface of the developing case 9. It has a toner concentration sensor 10 and the like.

The developing unit 11 includes a developing sleeve 12 facing the photoconductor 4 through the opening of the developing case 9, a magnet roller 13 provided inside the developing sleeve 13 so as not to rotate, and a doctor blade 14 whose tip approaches the developing sleeve 12. ing. The developing sleeve 12 has a non-magnetic, rotatable tubular shape. The magnet roller 13 has a plurality of magnetic poles that are sequentially arranged in the direction of rotation of the sleeve from a position facing the doctor blade 14. Each of these magnetic poles exerts a magnetic force on the two-component developer on the sleeve at a predetermined position in the rotational direction. As a result, the two-component developer sent from the stirring unit 7 is attracted to and supported on the surface of the developing sleeve 12, and a magnetic brush along the magnetic field lines is formed on the surface of the sleeve.

The magnetic brush is regulated to an appropriate layer thickness when passing through the position facing the doctor blade 14 as the developing sleeve 12 rotates, and then is conveyed to the developing region facing the photoconductor 4. Then, the toner is transferred onto the electrostatic latent image by the potential difference between the development bias applied to the developing sleeve 12 and the electrostatic latent image of the photoconductor 4, and contributes to the development. Further, it returns to the inside of the developing section 11 again with the rotation of the developing sleeve 12, separates from the sleeve surface due to the influence of the repulsive magnetic field formed between the magnetic poles of the magnet roller 13, and then returned to the inside of the stirring section 7. An appropriate amount of toner is supplied to the two-component developer in the stirring unit 7 based on the detection result by the toner concentration sensor 10. As the developing apparatus 6, instead of using a two-component developing agent, one using a one-component developing agent containing no magnetic carrier may be adopted.

The drum cleaning device 15 uses a method in which a cleaning blade 16 made of polyurethane rubber is pressed against the photoconductor 4, but other methods may be used. For the purpose of improving the cleanability, in this example, a contact conductive fur brush 17 that brings the outer peripheral surface into contact with the photoconductor 4 is rotatably provided in the direction of the arrow in the drawing. The fur brush 17 also has a role of applying the lubricant to the surface of the photoconductor 4 while scraping the lubricant from the solid lubricant into a fine powder. A metal electric field roller 18 for applying a bias to the fur brush 17 is rotatably provided in the direction indicated by the arrow in the drawing, and the tip of the scraper 19 is pressed against the electric field roller 18. The toner adhering to the fur brush 17 is transferred to the electric field roller 18 to which the bias is applied while rotating in contact with the fur brush 17 in the counter direction. Then, after being scraped from the electric field roller 18 by the scraper 19, it falls on the recovery screw 20. The recovery screw 20 transports the recovered toner toward the end of the drum cleaning device 15 in the direction orthogonal to the drawing surface, and delivers it to the external recycling transport device 21. The recycling transfer device 21 sends the delivered toner to the developing device 6 for recycling.

The static elimination lamp 22 eliminates static electricity from the photoconductor 4 by irradiation with light. The surface of the statically eliminated photoconductor 4 is uniformly charged by the charging device 23, and then subjected to an optical writing process by the optical writing device 2. As the charging device 23, a charging roller to which a charging bias is applied is rotated while being in contact with the photoconductor 4. A scorotron charger or the like that performs a non-contact charging treatment on the photoconductor 4 may be used.

In FIG. 2 shown above, K, Y, M, C toner images are formed on the photoconductors 4K, Y, M, and C of the four process units 3K, Y, M, and C by the process described so far. Will be done.

A transfer unit 24 is arranged below the four process units 3K, Y, M, and C. The transfer unit 24 moves the intermediate transfer belt 25 stretched by a plurality of rollers endlessly in the clockwise direction in the drawing while abutting on the photoconductors 4K, Y, M, and C. As a result, a primary transfer nip for K, Y, M, C in which the photoconductors 4K, Y, M, C and the intermediate transfer belt 25 come into contact with each other is formed. In the vicinity of the primary transfer nips for K, Y, M, and C, the intermediate transfer belt 25 is attached to the photoconductors 4K, Y, M, by the primary transfer rollers 26K, Y, M, and C arranged inside the belt loop. It is pressing toward C. A primary transfer bias is applied to each of these primary transfer rollers 26K, Y, M, and C by a power source. As a result, a primary transfer electric field is formed in the primary transfer nips for K, Y, M, and C to electrostatically move the toner image on the photoconductors 4K, Y, M, and C toward the intermediate transfer belt 25. Has been done. On the front surface of the intermediate transfer belt 25, which sequentially passes through the primary transfer nip for K, Y, M, and C as it moves in the clockwise direction in the figure, a toner image is formed on each primary transfer nip. Are sequentially superimposed and primary transferred. By the primary transfer of this superposition, a four-color superposition toner image (hereinafter referred to as a four-color toner image) is formed on the front surface of the intermediate transfer belt 25.

A paper transport unit 28 is provided at the lower part of the transfer unit 24 in the drawing, in which an endless paper transport belt 29 is hung between the drive roller 30 and the secondary transfer roller 31 to move the transfer unit 24 endlessly. Then, the intermediate transfer belt 25 and the paper transport belt 29 are sandwiched between its own secondary transfer roller 31 and the lower tension roller 27 of the transfer unit 24. As a result, a secondary transfer nip is formed in which the front surface of the intermediate transfer belt 25 and the front surface of the paper transport belt 29 come into contact with each other. A secondary transfer bias is applied to the secondary transfer roller 31 by a power source. On the other hand, the lower tension roller 27 of the transfer unit 24 is grounded. As a result, a secondary transfer electric field is formed in the secondary transfer nip.

A resist roller pair 33 is arranged on the right side in the drawing of the secondary transfer nip, and the secondary transfer paper sandwiched between the rollers is secondary at a timing capable of synchronizing with the four-color toner image on the intermediate transfer belt 25. Send to the transfer nip. In the secondary transfer nip, the four-color toner image on the intermediate transfer belt 25 is collectively secondary transferred to the transfer paper due to the influence of the secondary transfer electric field and the nip pressure, and combined with the white color of the transfer paper, a full-color image is obtained. The transfer paper that has passed through the secondary transfer nip is separated from the intermediate transfer belt 25, held on the front surface of the paper transport belt 29, and transported to the fixing device 34 along with its endless movement.

On the surface of the intermediate transfer belt 25 that has passed through the secondary transfer nip, the transfer residual toner that has not been transferred to the transfer paper by the secondary transfer nip is attached. The transfer residual toner is scraped off by a belt cleaning device that comes into contact with the intermediate transfer belt 25.

The transfer paper conveyed to the fixing device 34 is sent from the fixing device 34 to the paper ejection roller pair 35 after the full-color image is fixed by pressurization or heating in the fixing device 34, and then goes out of the machine. It is discharged.

In FIG. 1 shown above, a switchback device 36 is arranged under the paper transport unit 28 and the fixing device 34. As a result, the transfer paper that has been subjected to the image fixing process on one side is switched to the transfer paper reversing device side by the switching claw, is inverted there, and enters the secondary transfer nip again. Then, after the secondary transfer process and the fixing process of the image are performed on the other side, the paper is discharged onto the paper discharge tray.

The scanner 150 fixed on the image forming unit 1 has a first surface fixed reading unit 151 as a first surface reading means and a moving reading unit 152 as a first surface reading means.

The moving reading unit 152 as the first surface reading means is arranged directly under the second contact glass fixed to the upper wall of the casing of the scanner 150 so as to come into contact with the document MS, and is arranged from a light source, a reflection mirror, or the like. The optical system can be moved in the left-right direction in the figure. Then, in the process of moving the optical system from the left side to the right side in the figure, the light emitted from the light source is reflected by the document placed on the second contact glass, and then passed through a plurality of reflection mirrors. Light is received by the image reading sensor 153 fixed to the scanner body.

The first surface fixed reading unit 151 as the first surface reading means is arranged directly below the first contact glass fixed to the upper wall of the casing of the scanner 150 so as to come into contact with the document MS. Then, when the document MS conveyed by the ADF 51, which will be described later, passes over the first contact glass, the light emitted from the light source is sequentially reflected on the document surface and received by the image reading sensor via a plurality of reflection mirrors. To do. As a result, the first surface of the document MS is scanned without moving the optical system including the light source and the reflection mirror.

The scanner 150 also has a close contact image sensor that reads the second surface of the document MS. This close contact type image sensor will be described later.

The ADF 51 arranged on the scanner 150 mounts a document mounting table 53 for mounting the document MS before scanning, a transport unit 54 for transporting the document MS, and the document MS after scanning on the main body cover 52. It holds a document stack base 55 or the like for stacking. As shown in FIG. 4, it is supported so as to be swingable in the vertical direction by a hinge 159 fixed to the scanner 150. Then, the swing causes the movement like an opening / closing door to expose the first contact glass 154 and the second contact glass 155 on the upper surface of the scanner 150 in the opened state. In the case of a single-bound original such as a book in which one corner of a bundle of originals is bound, the originals cannot be separated one by one, so that the ADF 51 cannot convey the originals. Therefore, in the case of a single-bound original, the ADF 51 is opened as shown in FIG. 4, and then the single-bound original with the page to be read opened is placed face down on the second contact glass 155, and then the ADF 51 is opened. close. Then, the image of the page is read by the moving reading unit 152 shown in FIG. 1 of the scanner 150.

On the other hand, in the case of a bundle of originals in which a plurality of original MSs independent of each other are simply stacked, the original MSs are automatically conveyed one by one by the ADF 51, and the first surface fixed reading unit 151 in the scanner 150 and the ADF 51 are in close contact with each other. The type image sensor can be read in sequence. In this case, after setting the document bundle on the document loading table 53, the copy start button is pressed. Then, the ADF 51 sends the document MS of the document bundle placed on the document loading table 53 into the transport unit 54 in order from the top, and conveys the document MS toward the document stack table 55 while inverting it. In the process of this transfer, immediately after the original MS is inverted, it is passed directly above the first surface fixed reading unit 151 of the scanner 150. At this time, the image on the first surface of the original MS is read by the first surface fixed reading unit 151 of the scanner 150.

FIG. 5 is an enlarged configuration diagram showing the main configuration of the ADF 51 together with the upper portion of the scanner 150. Further, FIG. 6 is a block diagram showing a part of the electric circuit of the ADF 51 and the scanner 150. The ADF 51 includes a document setting unit A, a separation and transport unit B, a resist unit C, a turn unit D, a first read and transport unit E, a second read and transport unit F, a paper discharge unit G, a stack unit H, and the like.

As shown in FIG. 6, the ADF (51) has a controller 64 made of an ASIC (Application Specific Integrated Circuit) or the like, and can control various devices and sensors by the controller 64. A resist sensor 65, a document set sensor 63, a paper ejection sensor 61, a butt sensor 72, a document width sensor 73, a reading inlet sensor 67, a table raising sensor 59, and the like are connected to the controller 64. Further, a close contact type image sensor 95, a pickup motor 56, a paper feed motor 76, a read motor 77, a paper discharge motor 78, a bottom plate raising motor 79, a contact glass retracting motor 110, and the like are also connected. In addition, a main body control unit 200 that controls each device of the scanner is also connected. The scanner (150) has a main body control unit 200 including a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like. As a result, various devices and sensors inside the scanner 150 can be controlled. Further, it is connected to the controller 64 of the ADF (51) by the I / F 202, and various devices and sensors in the ADF 51 can be indirectly controlled via the controller 64.

In FIG. 5, the document setting unit A has a document mounting table 53 or the like on which a bundle of document MSs is set. Further, the separation / transport unit B separates the original MSs one by one from the set bundle of the original MSs and feeds them. Further, the resist unit C temporarily hits the supplied original MS and aligns the original MS before sending it out. Further, the turn portion D has a curved transport portion that is curved in a C shape, and the original MS is turned upside down while being folded back in the curved transport portion. Further, the first reading / conveying unit E conveys the document MS on the first contact glass 154 to the first surface fixed reading unit 151 arranged inside the scanner below the first contact glass 154. The first side of the manuscript MS is read. Further, the second reading and conveying unit F causes the close contact image sensor 95 to read the second surface of the original MS while transporting the original MS under the close contact image sensor 95. Further, the paper ejection unit G ejects the document MS from which the images on both sides have been read toward the stack unit H. Further, the stack unit H stacks the document MS on the document stack base 55.

In the original MS, the front end of the original is placed on the movable original table 53a that can swing in the directions a and b in the drawing according to the thickness of the bundle of the original MS, and the rear end of the original is on the original mounting table 53. It is set in the state of being placed on. At this time, the position in the width direction is adjusted by abutting the side guides on both ends in the width direction (direction orthogonal to the drawing paper surface) on the document mounting table 53. The document MS set in this way pushes up the lever member 62 oscillatingly arranged above the movable document table 53a. Then, the document set sensor 63 detects the set of the document MS and transmits the detection signal to the controller 64. Then, this detection signal is sent from the controller 64 to the main body control unit 200 via the I / F 202.

The document mounting table 53 holds a first length sensor 57 and a second length sensor 58 composed of a reflective photo sensor or an actuator type sensor that detects the length of the document MS in the transport direction. These length sensors detect the length of the original MS in the transport direction.

A pickup roller 80 that is movably supported in the vertical direction (arrows c and d in the figure) by a cam mechanism is arranged above the bundle of document MS placed on the movable document table 53a. .. This cam mechanism can move the pickup roller 80 up and down by being driven by the pickup motor 56. When the pickup roller 80 moves upward, the movable document table 53a swings in the direction of arrow a in the drawing, and the pickup roller 80 comes into contact with the top document MS in the bundle of document MS. Further, when the movable document table 53a rises, the table rise sensor 59 eventually detects the rise of the movable document table 53a to the upper limit. As a result, the pickup motor 56 stops and the movable document table 53a stops rising.

For the operation unit 201 provided on the main body of the copier, which consists of a numeric keypad, a display, etc., a key operation for setting a reading mode indicating whether the double-sided reading mode or the single-sided reading mode is performed by the operator, or a copy start key Pressing operation etc. is performed. That is, the operation unit 201 functions as a mode information acquisition means for acquiring information on whether the mode is the double-sided reading mode or the single-sided reading mode. When the copy start key is pressed, a document feeding signal is transmitted from the main body control unit 200 to the controller 64 of the ADF 51 via the I / F 202. Then, the pickup roller 80 is rotationally driven by the forward rotation of the paper feed motor 76, and the document MS on the movable document table 53a is sent out from the movable document table 53a.

When setting the double-sided scanning mode or the single-sided scanning mode, it is possible to collectively set both sides and single-sided for all the document MSs placed on the movable document table 53a. Further, the 1st and 10th original MSs are set to the double-sided scanning mode, while the other original MSs are set to the single-sided scanning mode, and so on. It is also possible to set.

The document MS sent out by the pickup roller 80 enters the separation and conveying section B and is sent to the contact position with the paper feed belt 84. The paper feed belt 84 is stretched by a drive roller 82 and a driven roller 83, and is endlessly moved in the clockwise direction in the drawing by the rotation of the drive roller 82 accompanying the forward rotation of the paper feed motor 76. A reverse roller 85, which is rotationally driven clockwise in the drawing by the forward rotation of the paper feed motor 76, is in contact with the lower tension surface of the paper feed belt 84. At the contact portion, the surface of the paper feed belt 84 moves in the paper feed direction. On the other hand, the reverse roller 85 is in contact with the paper feed belt 84 at a predetermined pressure, and when it is in direct contact with the paper feed belt 84 or only one original document MS is sandwiched in the contact portion. In that case, take it to the belt or the manuscript MS. However, when a plurality of original MSs are sandwiched between the contact portions, the rotating force is lower than the torque of the torque limiter, so that the original MS is rotationally driven clockwise in the figure opposite to the rotating direction. As a result, the reverse roller 85 applies a moving force in the direction opposite to the paper feeding to the document MS below the top, and only the top document MS is separated from several sheets.

The original MS separated into one sheet by the action of the paper feed belt 84 and the reverse roller 85 enters the resist portion C. Then, when passing directly under the abutting sensor 72, its tip is detected. At this time, the pickup roller 80 receiving the driving force of the pickup motor 56 is still rotationally driven, but the document MS is separated from the document MS by the lowering of the movable document table 53a, so that the document MS has an endless moving force of the paper feed belt 84. Transported only by. Then, the endless movement of the paper feed belt 84 continues for a predetermined time from the timing when the tip of the document MS is detected by the abutting sensor 72. After that, the tip of the document MS abuts on the contact portion between the pull-out drive roller 86 and the pull-out driven roller 87 that is rotationally driven while contacting the pull-out drive roller 86. With the tip of the original MS abutting against the abutting portions of both rollers, the rear end side of the original MS is fed in the paper feeding direction, so that the original MS is bent by a predetermined amount while the tip is bent. Positioned at the abutment. As a result, the skew (tilt) of the original MS is corrected, and the original MS is in a posture along the paper feeding direction.

In addition to the role of correcting the skew of the original MS, the pull-out driven roller 87 also has a role of conveying the skew-corrected original MS to the intermediate roller pair 66 on the downstream side in the original conveying direction, and the paper feed motor 76. It is rotationally driven by reversal. When the paper feed motor 76 reverses, the pull-out driven roller 87 and one of the rollers in the intermediate roller pair 66 that are in contact with each other start rotating, and the endless movement of the paper feed belt 84 stops. At this time, the rotation of the pickup roller 80 is also stopped.

The document MS sent out from the pull-out driven roller 87 passes directly under the document width sensor 73. The document width sensor 73 has a plurality of paper detection units including a reflective photo sensor and the like, and these paper detection units are arranged in the document width direction (direction orthogonal to the paper surface). The size of the original MS in the width direction is detected based on which paper detection unit detects the original MS. Further, the length of the document MS in the transport direction is detected based on the timing from when the front end of the document MS is detected by the abutting sensor 72 until the rear end of the document MS is not detected by the abutting sensor 72. ..

The tip of the document MS whose size in the width direction is detected by the document width sensor 73 enters the turn portion D and is sandwiched between the abutting portions between the rollers of the intermediate rollers vs. 66. The transport speed of the document MS by the intermediate roller pair 66 is set to be higher than the transport speed of the document MS in the first reading / transport unit E, which will be described later. As a result, the time required to feed the document MS to the first reading / conveying unit E is shortened.

The tip of the document MS conveyed in the turn portion D passes the position where the tip of the document faces the reading inlet sensor 67. As a result, when the tip of the document MS is detected by the reading inlet sensor 67, the intermediate roller is transported until the tip is transported to the position of the reading inlet roller pair (pair of 89 and 90) on the downstream side in the transport direction. The document transport speed of the pair 66 is reduced. Further, with the start of the rotational drive of the reading motor 77, one roller in the reading inlet roller pair (89, 90), one roller in the reading outlet roller pair 92, and one roller in the second reading outlet roller pair 93 Rotational drive is started for each.

In the turn portion D, the upper and lower surfaces are reversed while the document MS is transported by the curved transport path between the intermediate roller pair 66 and the reading inlet roller pair (89, 90), and the transport direction is folded back. .. Then, the tip of the document MS that has passed through the nip between the rollers of the reading inlet roller pair (89, 90) passes directly under the resist sensor 65. At this time, when the tip of the document MS is detected by the resist sensor 65, the document transfer speed is decelerated while applying a predetermined transfer distance, and the transfer of the document MS is temporarily stopped before the first reading transfer unit E. .. Further, a pause signal is transmitted to the main body control unit 200 via the I / F 202.

When the main body control unit 200 that has received the pause signal transmits the reading start signal, the rotation of the reading motor 77 is restarted under the control of the controller 64 until the tip of the document MS reaches the inside of the first reading and conveying unit E. The transport speed of the document MS is increased up to a predetermined transport speed. Then, at the timing when the tip of the document MS reaches the reading position by the first surface fixed reading unit 151, the controller 64 informs the main body control unit 200 of the gate signal indicating the sub-scanning direction effective image area of the first surface of the document MS. Is sent. This transmission is continued until the rear end of the document MS exits the reading position by the first surface fixed reading unit 151, and the first surface of the document MS is read by the first surface fixed reading unit 151. The timing at which the tip of the document MS reaches the reading position by the first surface fixed reading unit 151 is calculated based on the pulse count of the reading motor 77.

The tip of the document MS that has passed through the first reading / conveying unit E passes through the reading outlet roller pair 92, which will be described later, and then its tip is detected by the paper ejection sensor 61. When the single-sided reading mode is set, it is not necessary to read the second side of the original MS by the close contact type image sensor 95 described later. Therefore, when the tip of the original MS is detected by the paper ejection sensor 61, the forward rotation drive of the paper ejection motor 78 is started, and the paper ejection roller on the lower side in the drawing of the paper ejection roller pair 94 is in the clockwise direction in the drawing. It is driven to rotate. Further, the timing at which the rear end of the document MS exits the nip of the paper ejection roller vs. 94 is calculated based on the paper ejection motor pulse count after the tip of the document MS is detected by the paper ejection sensor 61. Then, based on this calculation result, the drive speed of the paper ejection motor 78 is decelerated at the timing immediately before the rear end of the original paper MS comes out of the nip of the paper ejection roller vs. 94, and the original paper MS is moved from the original paper stack base 55. Paper is ejected at a speed that does not pop out.

On the other hand, when the double-sided scanning mode is set, the timing from the detection of the tip of the document MS by the paper ejection sensor 61 to the arrival at the close contact image sensor 95 is based on the pulse count of the scanning motor 77. It is calculated. Then, at that timing, the controller 64 transmits a gate signal indicating an effective image area in the sub-scanning direction on the second surface of the document MS to the main body control unit 200. This transmission is continued until the rear end of the document MS exits the reading position by the contact image sensor 95, and the second surface of the document MS is read by the contact image sensor 95.

The close contact type image sensor 95 (CIS) as the second surface reading means coats the reading surface with a coating treatment for the purpose of preventing vertical streaks of reading due to adhesion of paste-like foreign matter adhering to the original MS to the reading surface. Is given. A second reading roller 96 as a document supporting means for supporting the document MS from the non-reading surface side (first surface side) is arranged at a position facing the close contact type image sensor 95. The second scanning roller 96 plays a role of preventing the original MS from floating at the scanning position by the close contact image sensor 95 and also functioning as a reference white portion for acquiring shading data in the close contact image sensor 95. There is. In this copier, the second scanning roller 96 is used as the document supporting means for supporting the document at the position facing the close contact type image sensor 95, but a guide plate-like one may be used.

FIG. 7 is a block diagram showing a main part of the electric circuit of the close contact type image sensor 95. As shown in the figure, the close contact type image sensor 95 has a light source unit 95a including an LED array, a fluorescent lamp, a cold cathode tube, and the like. Further, it has a plurality of sensor chips 95b arranged in the main scanning direction (direction corresponding to the document width direction). Further, it has a plurality of OP amplifier circuits 95c individually connected to each sensor chip 95b. It also has a plurality of A / D converters 95e individually connected to each OP amplifier circuit 95c. Further, it also has an image processing unit 95f, a frame memory 95g, an output control circuit 95h, an I / F circuit 95i, and the like.

The sensor chip 95b includes a photoelectric conversion element called a 1x contact image sensor and a condenser lens. Prior to the document entering the reading position by the close contact type image sensor 95, the lighting ON signal is sent from the controller 64 to the light source unit 95a. As a result, the light source unit 95a is turned on, and the light is directed toward the second surface of the document. The reflected light reflected by the second surface of the document is collected by the photoelectric conversion element by the condenser lens in the plurality of sensor chips 95b and read as image information. The image information read by each sensor chip 95b is amplified by the OP amplifier circuit 95c and then converted into digital image information by the A / D converter 95e. These digital image information are input to the image processing unit 95f, shading correction and the like are performed, and then temporarily stored in the frame memory 95g. After that, it is converted into a data format that can be accepted by the main body control unit 200 by the output control circuit 95h, and then output to the main body control unit 200 via the I / F circuit 95i. From the controller 64, a timing signal for notifying the timing when the tip of the document reaches the reading position by the close contact image sensor 95 (image data after that timing is treated as valid data), a light source lighting signal, a power supply, etc. Is to be output.

FIG. 8 is a diagram illustrating the transfer of the document MS of the first reading and transporting unit E.
As shown in FIG. 8A, the document MS is conveyed to the first reading and conveying unit E at an angle inclined with respect to the surface of the first contact glass 154. Therefore, the tip of the document MS hits the first contact glass 154 and is conveyed while being guided by the first contact glass 154 as shown in FIG. 8 (b). After that, as shown in FIG. 8C, when the tip of the original MS reaches the paper ejection side guide member 156 which is the downstream guide, the original MS is conveyed so as to be scooped up by the downstream guide. As a result, when the original MS is guided by the output side guide member 156, the original MS has a shape in which the tip side is held by the output side guide member 156 and does not come into contact with the first contact glass 154. It is transported in a good condition.

When the document MS passes through the first scanning and transporting unit E, dust adhering to the document MS adheres to the first contact glass 154, and vertical streaks are generated in the scanned image due to the influence of the dust. As shown in FIG. 8, the original MS is guided by the first contact glass 154 until the tip of the original reaches the output side guide member 156 and is scooped up by the output side guide member 156. Therefore, until the original paper MS is scooped up by the paper ejection side guide member 156, the tip of the original document MS gets into the scanner 150 without the first contact glass 154, and the original paper MS is scooped up by the paper ejection side guide member 156. It cannot be raised, and there is a risk of document jam.

On the other hand, when the tip of the original MS is scooped up by the output side guide member 156 and conveyed while being guided by the output side guide, the original MS is conveyed without jamming even without the first contact glass 154. be able to. Therefore, in the present embodiment, when the tip of the original MS reaches the output side guide member 156 and the original is guided by the output side guide member 156, the first contact glass 154 is referred to the original guide shown in FIG. It was moved from the position to the retracted position to prevent dust from adhering to the first contact glass 154. Hereinafter, a specific description will be given with reference to the drawings.

FIG. 9 is a diagram showing a state in which the first contact glass 154 is positioned at the retracted position.
As shown in FIG. 9, the end of the first contact glass 154 on the upstream side in the document transport direction is fixed to the rotation shaft 110a. The rotation shaft 110a is rotationally driven by the contact glass retracting motor 110 shown in FIG. The rotation shaft 110a is arranged on the upstream side in the transport direction with respect to the first contact glass 154, and arranges the document MS below the upstream guide member 120 that guides the document MS to the reading position of the first surface fixed reading unit 151. The rotating shaft 110a is arranged at a position hidden by the upstream guide member 120 with respect to the first reading / conveying unit E.

When the tip of the document MS reaches the paper ejection side guide member 156, the contact glass retracting motor 110 is driven to rotate the first contact glass 154, and the evacuation indicated by the solid line in the figure is displaced from the guide position indicated by the dotted line in the figure. Move to position. In the present embodiment, the first contact glass 154 is rotated by 90 degrees from the guide position indicated by the dotted line in the figure, and the first contact glass is stored inside the scanner 150. Specifically, the upstream guide member 120 moves to a position hidden from the first reading / conveying unit E. As a result, it is possible to prevent dust that has fallen from the document MS from adhering to the first contact glass 154. Further, by retracting the guide member 120 on the upstream side, the first contact glass 154 located at the retracted position does not interfere with the light irradiating the document or the light reflected from the document.

Further, the rotation shaft 110a may be provided below the paper ejection side guide member 156, and the first contact glass 154 may be rotated with the downstream end of the first contact glass 154 in the document direction as a fulcrum. At this time, the first contact glass 154 located at the retracted position is stored in the scanner in a form hidden by the paper ejection side guide member 156.

Further, in the present embodiment, by rotating 90 degrees from the guide position indicated by the dotted line in the drawing, the document facing surface of the first contact glass 154 facing the document becomes parallel to the vertical direction at the retracted position. As a result, even if dust of the document adheres to the document facing surface of the first contact glass 154 before the tip of the document MS reaches the paper ejection side guide member 156, the document MS moves to the retracted position. The attached dust falls from the surface facing the document. Therefore, it is possible to remove dust adhering to the document facing surface of the first contact glass 154 until the tip of the next document MS reaches the paper ejection side guide member 156.

Further, in the present embodiment, the rotation shaft 110a is rotated by the contact glass retracting motor 110. For example, a push portion extending in the normal direction is provided at one end of the rotation shaft 110a and is pushed by the actuator. The rotation shaft 110a may be rotated by pushing the portion.

Further, the first contact glass 154 may be rotated 180 degrees from the guide position indicated by the dotted line in the drawing to retract the first contact glass 154. As shown in FIG. 9, when the rotation range from the guide position to the retracted position is 90 degrees, the dust dropped from the document facing surface of the first contact glass 154 recontacts the document facing surface and faces the document again. It may adhere to the surface. On the other hand, by rotating the first contact glass 154 180 degrees, the document facing surface of the first contact glass 154 becomes the lower surface at the retracted position, so even if dust adhering to the document facing surface falls, it falls. There is an advantage that the dust does not reattach to the surface facing the document.

Further, the timing at which the tip of the document reaches the paper ejection side guide member 156 (the timing at which the movement from the guide position to the evacuation starts) can be calculated based on the pulse count of the reading motor 77. Specifically, the pulse count of the reading motor 77 corresponding to the distance + margin from the document resist position (the position where the transfer of the document MS is temporarily stopped before the first reading and transporting unit E) to the paper ejection side guide member 156. It is a number.

Further, when the rear end of the document reaches the paper ejection side guide member 156, the first contact glass 154 is moved from the retracted position to the guide position. The timing at which the rear end of the document reaches the paper ejection side guide member 156 (the timing at which the movement from the retracted position to the guide position starts) can also be calculated based on the pulse count of the reading motor 77. Specifically, it is the length in the transport direction of the original MS + the distance from the original resist position to the output side guide member 156 + the pulse count number of the reading motor 77 corresponding to the margin. The length of the document MS in the transport direction can be grasped from the detection results of the first length sensor 57 and the second length sensor 58 provided on the document mounting table 53.

When the depth of focus of the first surface fixed reading unit 151 is narrow, the first contact glass 154 is moved to the guide position before the rear end of the document MS reaches the first reading and conveying unit E. It is preferable to guide the rear end of the document MS with 1 contact glass 154. This is because when the first contact glass 154 is not in the guide position, the rear end of the document may pass through the reading position of the first surface fixed reading unit 151 in a form of entering the inside of the scanner. If the depth of focus of the first-side fixed reading unit 151 is narrow, the scanned image on the rear end side of the document that has entered the inside of the scanner may be out of focus. Therefore, when the depth of focus of the first surface fixed reading unit 151 is narrow, the first contact glass is moved to the guide position and the first contact is made before the rear end of the document MS reaches the first reading and conveying unit E. By guiding the rear end of the original document MS with the glass 154, the image of the rear end of the original document can be read well, which is preferable.

Further, the first contact glass 154 may be moved to the retracted position each time the document is conveyed. Further, when the dust on the first contact glass 154 is detected, the first contact glass 154 may be moved to the retracted position to suppress an abnormal image due to the dust and remove the dust at the retracted position. To detect dust, for example, an image is captured by the first surface fixed reading unit 151 when the document is not in the reading position. Then, the image captured by the software in the device is analyzed, and if, for example, the captured image has black spots or the like, it is determined that the first contact glass 154 has dust. Further, the photo interrupter may detect dust adhering to the document facing surface of the first contact glass 154. When no dust adheres to the document facing surface of the first contact glass 154, the light receiving portion of the photo interrupter detects the light of the light emitting portion. On the other hand, when dust adheres to the document facing surface of the first contact glass 154, the dust blocks the light of the light emitting portion of the photo interrupter, and the light receiving portion does not detect the light. As a result, it is detected that dust has adhered to the document facing surface of the first contact glass 154.

Further, when the specified number of original documents are conveyed, the first contact glass 154 may be moved to the retracted position, and dust adhering to the first contact glass 154 may be dropped and removed. The specified number of sheets for moving the first contact glass 154 to the retracted position may be set by the user by operating the operation unit 201.

FIG. 10 is a schematic view showing an example in which a suction fan 111 for sucking dust adhering to the document facing surface of the first contact glass 154 located at the retracted position is provided.
As shown in FIG. 10, the suction fan 111 as the deposit removing means is arranged below the end portion on the opposite side of the rotation fulcrum of the first contact glass 154 in the retracted position. When the first contact glass 154 is in the retracted position, the suction fan 111 is driven. When the suction fan 111 is driven, an air flow W is generated along the document facing surface of the first contact glass 154 as shown by an arrow in the figure. The air flow W sucks the dust adhering to the document facing surface of the first contact glass 154 into the suction fan 111, and the dust adhering to the document facing surface of the first contact glass 154 is removed. The suction by the suction fan 111 may be executed each time the first contact glass 154 is positioned at the retracted position, or may be executed when it is detected that dust has adhered to the first contact glass 154. Further, when the specified number of documents are conveyed, the suction fan 111 may perform suction.

FIG. 11 is a diagram showing another example in which a suction fan 111 for sucking dust adhering to the document facing surface of the first contact glass 154 located at the retracted position is provided.
FIG. 11 is provided so as to be hidden below the paper ejection side guide member 156, and the suction fan 111 is arranged so as to face the document facing surface of the first contact glass 154 in the retracted position with the reading position in between. It is a thing. Also in the configuration shown in FIG. 11, the airflow W generated by the suction fan 111 can suck and remove dust adhering to the document facing surface of the first contact glass 154 by the suction fan 111. In addition, the removed dust can be collected at a predetermined location or discharged to the outside of the scanner. In addition, dust that has entered the scanner can also be sucked, and dust such as the first surface fixed reading unit 151 can be suppressed from adhering.

In the configuration in which the suction fan 111 shown in FIG. 10 is arranged below the first contact glass 154 located at the retracted position, the airflow W of the suction fan 111 supports dust falling from the first contact glass 154 by its own weight. It will be shaped like a glass. Therefore, there is an advantage that the dust removing power is high. However, the device may become large in the vertical direction. On the other hand, in FIG. 11, although the dust removing power is inferior to that of the configuration of FIG. 10, it is possible to avoid an increase in size in the vertical direction as compared with FIG.

FIG. 12 is a flow chart showing an example of the retracting operation of the first contact glass 154.
First, the controller 64, which is a control unit, measures the length of the document MS to be transported in the transport direction (S1). The document transport length is detected by the first length sensor 57 and the second length sensor 58. Next, the pickup motor 56 rotationally drives the pickup roller 80 to start the document transfer (S2). Then, the tip of the document MS is detected by the resist sensor 65, the document transfer speed is decelerated while applying a predetermined transfer distance, and the transfer of the document MS is temporarily stopped before the first reading transfer unit E. Then, when the rotation of the read motor 77 is restarted, the measurement of the pulse count of the read motor 77 is started (S3).

The controller 64 monitors from the pulse count value whether or not the tip of the document reaches the paper ejection side guide member 156, and when the pulse count number reaches the timing when the tip of the document reaches the paper ejection side guide member 156. , Check whether it is in the intermittent operation mode (S5). The intermittent operation mode is a mode for moving the first contact glass 154 to the retracted position when the adhesion of dust to the first contact glass 154 is detected, and is set by the user operating the operation unit 201. The mode.

When the intermittent operation mode is set (YES in S5), it is checked whether or not the means for detecting dust on the document facing surface of the first contact glass 154 detects dust (S6). The dust may be detected by the photo interrupter as described above, or may be detected based on the captured image.

If no dust is detected (No in S6), it is checked whether or not the number of documents to be conveyed is the specified number (S7). When the number of originals to be conveyed is not the specified number (No in S7), the first contact glass 154 is not retracted.

On the other hand, when the operation mode is not intermittent (No in S5), the dust is detected in the intermittent operation mode (Yes in S6), or the number is specified (Yes in S7), the first contact glass 154 Is moved from the guide position to the retracted position (S8). Then, when the first contact glass 154 moves to the retracted position, the suction fan 111 is driven (S9) to perform an operation of removing dust adhering to the first contact glass 154.

Next, the controller 64 checks whether or not the pulse count value of the reading motor 77 has reached the pulse count value at the timing when the rear end of the document MS reaches the paper ejection side guide member 156. The pulse count value at the timing when the rear end of the document MS reaches the paper ejection side guide member 156 is the pulse count value at the timing when the front end of the document MS reaches the paper ejection side guide member 156, and the document is conveyed as detected in S1. It is a value obtained by adding the pulse count value corresponding to the direction length.

When the pulse count value of the reading motor 77 becomes the pulse count value at the timing when the rear end of the document MS reaches the paper ejection side guide member 156 (Yes in S11), the first contact glass 154 is moved from the retracted position to the guide position. (S12), and the drive of the suction fan 111 is stopped (S13). Then, when there is the next manuscript (No in S14), the steps after S1 are executed again. If there is no next manuscript (Yes in S14), the process ends.

Further, in the present embodiment, the operation of the first contact glass 154 to the retracted position is started at the timing when the tip of the original MS reaches the paper ejection side guide member 156, but from the first contact glass 154. The movement of the retracted position may be started at the timing when the tip of the document MS reaches the reading outlet roller pair 92 arranged on the downstream side in the transport direction.

What has been described above is an example, and has a unique effect in each of the following aspects.
(Aspect 1)
Between a reading means such as a first surface fixed reading unit 151 that reads an image of an object such as a document MS to be conveyed, and a conveying path such as the first reading and conveying unit E to which the object is conveyed and the reading means. In an image reading device such as a document reading device 50 provided with a translucent member such as the first contact glass 154 arranged, the retracting means for retracting the translucent member from between the transport path and the reading means ( In this embodiment, it is provided with a rotating shaft 110a, a contact glass evacuation motor 110, and the like) and a control means such as a controller 64 that controls the evacuation means based on the transport position of the object.
Although the occurrence of jam is suppressed by guiding an object such as a document MS conveyed to a reading position of a reading means such as the first surface fixed reading unit 151 by a translucent member such as the first contact glass 154. For example, when the tip of the object is held by the transport member or the guide member on the downstream side in the transport direction from the translucent member, jam does not occur even if the translucent member does not guide the object. As described above, it is not necessary to position the light transmitting member between the transport path and the reading means depending on the transport position of the object.
Therefore, in the first aspect, the evacuation means for retracting the light transmitting member from between the transfer path and the reading means is controlled based on the transfer position of the object. As a result, when the object is in the transport position where the guide of the translucent member is required, the translucent member can be positioned between the transport path and the reading means, and the translucent member can move the object. It can be guided to suppress the occurrence of jam. On the other hand, when the object is in a transport position where the guide of the light-transmitting member is not required, the light-transmitting member can be retracted from between the transport path and the reading means, as compared with a non-retracted object. It is possible to prevent dust and the like from adhering to the translucent member. In this way, since it is possible to suppress the adhesion of dust and the like to the translucent member, it is possible to reduce the frequency with which the user cleans the translucent member. As a result, it is possible to reduce the chance of having to clean the translucent member.

(Aspect 2)
In the first aspect, the control means such as the controller 64 is such that the tip of the object such as the document MS is provided on the downstream side in the transport direction with respect to the translucent member such as the first contact glass 154. After being positioned at the transport position held by the member on the downstream side of the above, the retracting means is controlled so as to retract the translucent member from between the transport path and the reading means.
According to this, the occurrence of jam can be suppressed, and the adhesion of dust or the like to the translucent member such as the first contact glass 154 can be suppressed.

(Aspect 3)
In the first or second aspect, the retracting means is the first contact glass 154 or the like at the retracting position retracted from between the transport path such as the first reading transport unit E and the reading means such as the first surface fixed reading unit 151. The translucent member is retracted so that the posture of the transmissive member is such that the deposits adhering to the transmissive member fall under its own weight.
According to this, as described in the embodiment, by moving the translucent member such as the first contact glass 154 to the retracted position, it is possible to remove the deposits such as dust adhering to the transmissive member. This eliminates the need to manually remove the adhesion to the translucent member.

(Aspect 4)
In any one of aspects 1 to 3, the first contact glass 154 or the like located at a retracted position retracted from between a transport path such as the first reading transport unit E and the reading means such as the first surface fixed reading unit 151. A deposit removing means such as a suction fan 111 for removing the deposits adhering to the translucent member is provided.
According to this, as described in the embodiment, the deposits such as dust adhering to the translucent member such as the first contact glass 154 can be removed manually by the deposit removing means such as the suction fan 111. It is not necessary to remove the adhesion to the translucent member.

(Aspect 5)
In the fourth aspect, the deposit removing means sucks the deposits adhering to the translucent member such as the first contact glass 154 and removes them from the translucent member.
According to this, as described in the embodiment, the airflow can remove the deposits adhering to the translucent member such as the first contact glass 154, and slides on the surface of the first contact glass 154. Compared with the case of removing the deposits adhering to the translucent member, it is possible to suppress scratches on the surface of the translucent member.

(Aspect 6)
In any of aspects 3 to 5, deposit detection means for detecting deposits adhering to a translucent member such as the first contact glass 154 (in this embodiment, a photo interrupter or a first surface fixed reading unit 151 in the apparatus). The control means such as the controller 64 has software for analyzing the image captured by the above, and when the deposit detecting means detects that the deposit is attached to the translucent member, the manuscript MS or the like The control of the retracting means based on the transport position of the object is executed.
According to this, it is possible to suppress the entry of dust into the scanner as compared with the case where the translucent member such as the first contact glass 154 is moved to the retracted position each time.

(Aspect 7)
In any of aspects 3 to 6, the control means such as the controller 64 controls the evacuation means based on the transport position of the object such as the document MS when the number of transports of the object such as the document MS reaches the specified number of times. Execute.
According to this, it is possible to suppress the entry of dust into the scanner as compared with the case where the translucent member such as the first contact glass 154 is moved to the retracted position each time.

(Aspect 8)
In an image forming apparatus including an image reading means such as a document reading device 50 and an image forming means such as an image forming unit 1 that forms an image based on image data read by the image reading means, as the image reading means. The image reader according to any of aspects 1 to 7 was used.
According to this, it is possible to copy a good image in which vertical streaks are suppressed.

1: Image forming unit 2: Optical writing device 3: Process unit 4: Photoreceptor 6: Developing device 7: Stirring unit 8: Conveying screw 9: Development case 10: Toner density sensor 11: Development unit 12: Development sleeve 13: Magnet roller 14: Doctor blade 15: Drum cleaning device 16: Cleaning blade 17: Fur brush 18: Electric field roller 19: Scraper 20: Recovery screw 21: Recycling transfer device 22: Static elimination lamp 23: Charging device 24: Transfer unit 25: Intermediate Transfer belt 27: Lower tension roller 28: Paper transport unit 29: Paper transport belt 30: Drive roller 31: Secondary transfer roller 33: Resist roller pair 34: Fixing device 35: Paper discharge roller pair 36: Switchback device 37: Paper feed path 40: Blank paper supply device 41: Paper bank 42: Paper feed cassette 43: Sending roller 44: Paper feed path 45: Separation roller 47: Conveying roller 50: Document reading device 52: Main body cover 53: Document mounting table 53a: Movable document table 54: Conveying unit 55: Document stack table 56: Pickup motor 57: First length sensor 58: Second length sensor 59: Table raising sensor 61: Paper ejection sensor 62: Lever member 63: Document set sensor 64 : Controller 65: Resist sensor 66: Intermediate roller pair 67: Reading inlet sensor 72: Butt sensor 73: Document width sensor 76: Paper feed motor 77: Reading motor 78: Paper ejection motor 79: Bottom plate raising motor 80: Pickup roller 82 : Drive roller 83: Driven roller 84: Paper feed belt 85: Reverse roller 86: Pullout drive roller 87: Pullout driven roller 92: Read outlet roller pair 93: Second read outlet roller pair 94: Paper discharge roller pair 95: Adhesion type Image sensor 95a: Light source 95b: Sensor chip 95c: OP amplifier circuit 95e: A / D converter 95f: Image processing unit 95g: Frame memory 95h: Output control circuit 95i: I / F circuit 96: Second reading roller 110: Contact Glass retracting motor 110a: Rotating shaft 111: Suction fan 120: Upstream guide member 150: Scanner 151: First surface fixed reading unit 152: Moving reading unit 153: Image reading sensor 154: First contact glass 155: Second Contact glass 156: Paper ejection side guide member 159: Hinge 200: Main body control unit 201: Operation unit A: Document setting unit B: Separation transfer unit C: Resist unit D: Turn unit E: First reading and transporting unit F: Second Reading and transporting unit G: Paper ejection unit H: Stacking unit MS: Document W: Airflow

Japanese Unexamined Patent Publication No. 2012-10248

Claims (7)

A reading means that reads the image of the object to be transported,
In an image reading device provided with a light-transmitting member arranged between a transport path through which the object is transported and the reading means.
A retracting means for retracting the translucent member from between the transport path and the reading means,
A control means for controlling the evacuation means based on the transport position of the object is provided .
When the tip of the object is positioned at a transport position held by a member on the downstream side in the transport direction with respect to the light-transmitting member, the control means transfers the light-transmitting member to the transport path. An image reading device characterized in that the retracting means is controlled so as to retract from between the scanning means and the reading means . The image reading apparatus according to 請Motomeko 1,
The evacuation means is such that the posture of the translucent member at the evacuation position retracted from between the transport path and the reading means is such that the deposits adhering to the transmissive member fall by its own weight. An image reading device characterized in that the translucent member is retracted. In the image reading apparatus according to claim 1 or 2 .
An image reading device characterized in that a deposit removing means for removing deposits adhering to the translucent member located at a retracted position retracted from between the transport path and the reading means is provided. In the image reading apparatus according to claim 3 ,
The image reading device is characterized in that the deposit removing means sucks the deposits adhering to the translucent member and removes the deposits from the translucent member. In the image reading apparatus according to any one of claims 2 to 4 .
It has a deposit detecting means for detecting the deposits adhering to the translucent member.
The control means is characterized in that when the deposit detecting means detects that the deposit is attached to the translucent member, the control means controls the retracting means based on the transport position of the object. Reader. In the image reading apparatus according to any one of claims 2 to 4 .
The image reading device is characterized in that, when the number of times the object is conveyed reaches a predetermined number of times, the control means controls the evacuation means based on the position of the object being conveyed. Image reading means and
In an image forming apparatus including an image forming means for forming an image based on the image data read by the image reading means.
An image forming apparatus according to claim 1, wherein the image reading apparatus according to any one of claims 1 to 6 is used as the image reading means.

Images