JP2006270272A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image reading apparatus which can maintain the inspection precision of image quality and can be realized using a compact constitution. <P>SOLUTION: The image reading apparatus 10 can read the image of a form S by a reading means 28; whereas, when the image is not read, it will be in the state where a reading counter part unit 70 carried out an upper part movement and the top surface of a lower plate 74 constitutes the part of a conveyance way, and a top plate 72 blocks the reading window 20 of a housing 18, and a white reference surface 76 dissociates and retreats from the conveyance way. Moreover, the reading window 20 of the housing 18 is closed by a shutter 26, and a contact image sensor 16 is covered from the outside. For this reason, it is hard to produce dirt and dust sticking in the top surface and the white reference level 76 of the top plate 72. Furthermore, the reading means 28 itself is also hard to become less likely to be dirty. Thus, the contact image sensor 16 does not read the adhered image of the dirt or the dust, and it can prevent the quality of the image of the read image deteriorating. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that reads an image on a sheet in order to perform quality inspection or the like of an image recorded on the sheet.

  2. Description of the Related Art An image reading apparatus that is applied to an image recording apparatus or the like and that reads an image on the sheet in order to perform quality inspection of an image recorded on a sheet (printed paper, test paper, or the like) is known.

  In this type of image reading apparatus, an image sensor (reading means) such as a CCD for reading an image of a sheet conveyed through a predetermined conveyance path (paper discharge path) and a light source are provided, and the sheet is irradiated by the light source. Captured image data is generated by detecting reflected light of the light, and a captured image of the paper is obtained.

  By the way, in such a system that strictly inspects such a print output state (image formation state of the print paper) for defects such as “streaks” generated in the print output using the test chart print, dust (paper) As well as dust and dust), dirt at the image reading position (reading facing portion) and dust adhering by the image sensor also affect reading accuracy as a white reference surface for shading correction or as a reading background. Further, when the reading facing portion becomes dirty, it also affects the contamination of the imaging element facing the reading facing portion.

  For this reason, various techniques for preventing the adhesion of dirt and dust have been proposed (see, for example, Patent Documents 1 to 3).

  In the technique disclosed in Patent Document 1, the reading conveyance path and the recording paper conveyance path are shared, and in the recording mode, the white reference member that serves as the opposed surface of the reading unit and the document pressing means is provided by a hinge. It is the structure made to open and retreat from a conveyance path. Similarly, in the technique disclosed in Patent Document 2, the reading conveyance path and the recording paper conveyance path are shared, and the reading unit and the white reference plate for shading correction are integrated in the recording mode. It is the structure which carries out open rotation retraction from a conveyance path. Furthermore, in the technique disclosed in Patent Document 3, the shutter is opened only when white reference data is acquired, and the white correction plate for shading correction is exposed.

  However, the technique disclosed in Patent Document 1 as described above is not configured to retract the reading unit itself, and thus has a drawback that the reading unit is not prevented from being contaminated. Further, in the technique disclosed in Patent Document 2, since the reading unit and the white reference plate are retracted integrally, the apparatus becomes large. In particular, in the case of a reading unit compatible with high-speed printing, even if the same contact type sensor is used, the size of the apparatus is increased because parallel output or the like is performed. Furthermore, in the technique disclosed in Patent Document 3, if an attempt is made without changing the height of the sheet conveying surface in order to maintain the sheet feeding performance, the mechanism becomes significantly complicated.

As described above, any of the conventional techniques for preventing the adhesion of dirt and dust has some drawbacks, and a countermeasure for solving this problem has been desired.
JP 2003-152958 A JP 2004-186909 A JP-A-7-107284

  An object of the present invention is to obtain an image reading apparatus that can maintain the inspection accuracy of the image quality and can realize this with a compact configuration in consideration of the above facts.

  An image reading apparatus according to a first aspect of the present invention is an image reading apparatus that reads an image of a sheet conveyed on a predetermined conveyance path by a reading unit, and is an image reading position by the reading unit and a part of the conveyance path. Is configured to be separated and retracted from the conveyance path when the image is not read by the reading unit.

  In the image reading apparatus according to the first aspect, the image of the sheet conveyed on the conveyance path is read by the reading unit. On the other hand, when the image is not read by the reading unit, the reading facing portion that is an image reading position by the reading unit and forms a part of the transport path is separated from the transport path and retracted.

  Here, in a system for reading and inspecting by applying such an image reading apparatus, the frequency of the inspection is, for example, several times a week, and about several test chart prints are read. Since the print paper output that does not become is several hundred to several thousand sheets, such a normal printing (the reading means) is performed at the reading facing portion (image reading position by the reading means) constituting a part of the conveyance path. Dirt and dust adhere to the image when the image is not read. On the other hand, at the time of such normal printing, since the reading facing portion that is the image reading position by the reading unit and constitutes a part of the conveyance path as described above is separated from the conveyance path and retracted, the image Dirt and dust are unlikely to occur at the reading position (reading facing portion). In addition, since dirt and dust are less likely to occur at the reading facing portion, the reading means positioned opposite to the reading facing portion is also less likely to get dirty.

  Therefore, when the image is read by the reading unit, the reading unit does not read an image with dirt or dust, and it is possible to prevent the image quality of the image read by the reading unit from being deteriorated.

  The image reading apparatus according to a second aspect of the invention is the image reading apparatus according to the first aspect, wherein a test paper is applied as the paper in a state where the reading facing portion constitutes a part of the conveyance path, The transport path forms a test paper transport path, and in a state where the reading facing portion is separated from the transport path and retracted, print paper is applied as the paper, and the transport path forms a print paper transport path. It is characterized by that.

  3. The image reading apparatus according to claim 2, wherein when the image is read by the reading means (that is, in a state in which the reading facing portion constitutes a part of the conveyance path), the conveyance path forms a test paper conveyance path and is tested as a sheet. When paper is applied and the image is not read by the reading means (that is, when the reading facing portion is separated from the conveyance path and retracted), the conveyance path forms the print paper conveyance path and the print paper is applied as the paper. Therefore, the conveyance path for normal print paper output and the conveyance path for test paper output at the time of inspection can be shared, and the apparatus can be made compact as a whole.

  An image reading apparatus according to a third aspect of the present invention is the image reading apparatus according to the first or second aspect, further comprising a shielding member capable of shielding the reading unit from the outside when the image is not read by the reading unit. It is characterized by that.

  In the image reading apparatus according to the third aspect, the reading unit can be shielded from the outside by the shielding member. Therefore, when the image is not read by the reading unit (that is, at the time of normal printing, the reading facing portion is separated from the conveyance path). In the state of being separated and retracted), it is possible to more reliably prevent the reading means itself from becoming dirty or from attaching dust.

  An image reading apparatus according to a fourth aspect of the present invention is the image reading apparatus according to any one of the first to third aspects, wherein the sheet is pressed against the reading when the image is read by the reading unit. A sheet pressing member that is held on the part is provided.

  In the image reading apparatus according to the fourth aspect, when the image is read by the reading unit, the sheet is pressed by the sheet pressing member and held on the reading facing portion. Accordingly, it is possible to prevent the reading accuracy from deteriorating because the brightness at the time of reading or the focus state does not change due to the floating of the paper (test chart print paper) that is the object to be read.

  According to a fifth aspect of the present invention, there is provided an image reading apparatus having an image sensor housed in a housing, provided corresponding to a predetermined conveyance path, and forming an image of a sheet conveyed along the conveyance path in the housing. A reading means for reading by the image pickup device through the reading window, an upper plate provided with a white reference surface on an upper surface, and a lower plate provided facing the lower side of the upper plate, and the transport path The upper surface of the upper plate constitutes a part of the transport path in the state of being moved downward, and the upper surface of the lower plate is a part of the transport path in the state of being moved upward. And a reading counter unit in which the upper plate closes the reading window of the housing and the white reference surface is separated and retracted from the conveyance path.

  In the image reading apparatus according to claim 5, the reading facing unit is provided so as to be movable up and down corresponding to the conveyance path, and the upper surface of the upper plate constitutes a part of the conveyance path when moved downward, On the other hand, the upper surface of the lower plate constitutes a part of the transport path in a state where it has moved upward.

  Further, the image of the sheet conveyed on the conveyance path is read by the reading unit. That is, the reading facing unit is moved downward, and the upper surface of the upper plate forms a part of the conveyance path, and the image of the paper conveyed on the conveyance path and the white reference surface of the upper plate are accommodated in the housing. It is read through the reading window by the image pickup device. On the other hand, when the image is not read by the reading means, the reading facing unit moves upward, and the upper surface of the lower plate forms a part of the conveyance path, and the upper plate closes the reading window of the housing and The reference plane is separated from the conveyance path and retracted.

  Here, in a system for reading and inspecting by applying such an image reading apparatus, the frequency of the inspection is, for example, several times a week, and about several test chart prints are read. Since the print paper output that does not become is several hundred to several thousand, the upper surface of the lower plate of the reading counter unit that has been moved upward is displayed on the upper surface of the reading counter unit during such normal printing (when the image is not read by the reading means). ) Is contaminated with dirt and dust. On the other hand, during such normal printing, the upper surface (white reference surface) of the upper surface of the reading counter unit that has been moved upward as described above is separated from the conveyance path and retracted. On the upper surface of the upper plate and the white reference surface), dirt and dust are less likely to occur. Further, the image reading position is less likely to be contaminated with dirt and dust, and the upper plate closes the reading window of the housing, so that the image pickup device located opposite to the image reading position is also less likely to get dirty.

  Therefore, when the image is read by the reading unit (image pickup device), the image pickup device does not read an image with dirt or dust attached, and it is possible to prevent the image quality of the image read by the image pickup device from being deteriorated.

  According to a sixth aspect of the present invention, in the image reading device according to the fifth aspect, in the state where the reading facing unit moves downward, a test paper is applied as the paper, and the conveyance path is a test. In a state where a paper transport path is formed and the reading counter unit is moved upward, print paper is applied as the paper, and the transport path forms a print paper transport path.

  According to another aspect of the image reading apparatus of the present invention, when the image is read by the reading means (that is, when the reading facing unit is moved downward), the conveyance path forms the test paper conveyance path and the test paper is applied as the paper. When the image is not read by the reading means (that is, when the reading counter unit moves upward and the upper surface (white reference surface) of the upper plate is separated from the conveyance path and retracted), the conveyance path is the same as the print paper conveyance path. Since the printed paper is applied as the paper, it is possible to share the transport path for normal print paper output and the transport path for test paper output at the time of inspection. It can be.

  An image reading apparatus according to a seventh aspect of the present invention is the image reading apparatus according to the fifth or sixth aspect, further comprising a shutter capable of closing the reading window of the housing.

  In the image reading apparatus according to claim 7, since the image sensor can be shielded from the outside by closing the reading window of the housing with the shutter, for example, when the image is not read by the reading unit (image sensor) (that is, If the shutter is operated during normal printing and the reading counter unit moves upward and the upper surface (white reference surface) of the upper plate is separated from the conveyance path and retracted, the image sensor itself becomes dirty or dusty. Can be more reliably prevented.

  An image reading apparatus according to an eighth aspect of the present invention is the image reading apparatus according to the seventh aspect, wherein the shutter is in the closed state of the reading window when the reading counter unit is moved upward and is opposed to the shutter. The upper surface of the upper plate of the unit unit is in close contact with each other, and the white reference surface is not exposed.

  In the image reading apparatus according to claim 8, when the reading counter unit is moved upward, in other words, when the image is not read by the reading means (imaging device) (that is, during normal printing, the upper surface of the upper plate (white) In a state in which the reference surface) is separated from the conveyance path and retracted, the shutter is activated and the reading window is closed. In addition, at this time, the upper surface of the upper plate of the reading facing unit closely contacts the shutter, and the white reference surface is not exposed. Therefore, it is possible not only to reliably prevent the image sensor from becoming dirty or from attaching dust, but also to more reliably prevent the upper surface (white reference surface) of the upper plate from becoming dirty or from attaching dust, thereby further ensuring shading correction. Can be done.

  An image reading apparatus according to a ninth aspect of the present invention is the image reading apparatus according to any one of the fifth to eighth aspects, wherein the sheet is pressed by pressing the sheet in a state where the reading facing unit moves downward. A sheet pressing member that is held on the upper surface of the upper plate of the reading facing unit is provided.

  In the image reading apparatus according to claim 9, the sheet is pressed by the sheet pressing member and held on the upper surface of the upper plate while the reading facing unit is moved downward (that is, when the reading unit reads an image). . Therefore, it is possible to prevent the reading accuracy from being lowered without changing the brightness at the time of reading or changing the focus state due to the floating of the paper (test paper) that is the object to be read.

  As described above, the image reading apparatus according to the present invention has an excellent effect that the inspection accuracy of the image quality can be maintained (deterioration of the image quality of the captured image can be prevented) and this can be realized with a compact configuration.

  1 and 2 are schematic sectional views showing the configuration of an image reading apparatus 10 according to an embodiment of the present invention.

  The image reading apparatus 10 reads an image of the paper S that is conveyed along a guide plate 66 that constitutes a conveyance path. Hereinafter, for convenience of explanation, in FIGS. 1 and 2, the left side is the upstream side in the transport direction, and the right side is the downstream side in the transport direction. In FIGS. 1 and 2, only the sheet S is schematically (three-dimensionally) shown.

  The image reading apparatus 10 includes a housing 18 having a substantially rectangular box shape. The pair of side walls 32 and 34 facing each other of the housing 18 are formed in a slope shape with lower portions approaching each other downward, and the housing 18 is somewhat tapered downward. The bottom portion of the housing 18 is opened, and this opening portion is a reading window 20. The reading window 20 communicates the inside of the housing 18 with the outside.

  On the other hand, an air inlet 22 is formed in the upper part of the side wall 34 of the housing 18, and the inside and outside of the housing 18 communicate with each other.

  The fan 18 is accommodated in the housing 18. The fan 24 is disposed in the vicinity of the air inlet 22, and external air is sucked into the housing 18 when the fan 24 is driven (actuated). In addition, a filter 23 is attached to the intake port 22 to prevent dust from entering the housing 18 from the outside of the housing 18.

  The light source 12 is accommodated in the housing 18 as described above. The light source 12 is disposed on the upper left side of the reading window 20. The light source 12 has a reflecting plate 13 formed so as to wrap around the outer periphery from the lower left to the right in the clockwise direction. The light source 12 emits light toward the lower right including the reading window 20 side. To do.

  A reflector 14 is accommodated in the housing 18. The reflector 14 is disposed on the upper right side of the reading window 20. The reflector 14 corresponds to the light source 12 and is arranged with the reflecting surface facing downward to the left. The reflector 14 reflects the light emitted from the light source 12 to the lower left including the reading window 20 side.

  A reading means 28 is accommodated in the housing 18. The reading unit 28 includes the contact image sensor 16 and the lens array 30 as image pickup elements, and is disposed above the light source 12 and the reflector 14 corresponding to the center position of the reading window 20. The reading means 28 (contact image sensor 16 and lens array 30) faces a reading facing unit 70 described later, and its optical axis faces downward. The contact image sensor 16 detects light propagating from below and converts it into an electrical signal. An image processing unit (not shown) is connected to the contact image sensor 16 and generates captured image data of an image on the paper S based on an electrical signal from the contact image sensor 16.

  A plate-like shutter 26 as a shielding member is attached to the bottom of the housing 18. The shutter 26 can be moved along the housing 18 by a solenoid (not shown) or the like attached to the housing 18 (can be moved in a region on the right side with respect to the position of the reading window 20). The inside of the housing 18 can be shielded from the outside by closing 20.

  Further, a mylar 36 as a paper pressing member is provided at the bottom of the housing 18. The mylar 36 has elasticity in the thickness direction, and can be moved back and forth along the housing 18 toward the reading window 20 by a solenoid (not shown) attached to the housing 18 (the position of the reading window 20 is changed). It is possible to move in the area on the left side as a standard). When the mylar 36 advances toward the reading window 20, the sheet S conveyed onto a reading facing unit 70 (sheet reading position) described later is pressed to prevent the sheet S from being lifted. It is configured to be able to.

  On the other hand, a reading facing unit 70 is disposed below the housing 18. As shown in FIG. 3, the reading facing unit 70 has an upper plate 72 and a lower plate 74 provided facing the lower side of the upper plate 72 and is configured in a box shape as a whole. Corresponding to the above-mentioned guide plate 66 constituting the S transport path, it is provided so as to be movable up and down. A white reference surface 76 is provided on the upper surface of the upper plate 72.

  When the reading facing unit 70 is moved downward as shown in FIG. 1, the upper surface of the upper plate 72 forms a part of the transport path. Moreover, in this state, a test paper is applied as the paper S, and the transport path is configured to form a test paper transport path. On the other hand, in the state of being moved upward as shown in FIG. 2, the upper surface of the lower plate 74 constitutes a part of the conveyance path, and the upper plate 72 closes the reading window 20 of the housing 18 and the white reference surface 76 is separated from the conveyance path. It is configured to evacuate separately. In addition, in this state, print paper is applied as the paper S, and the transport path is configured to form a print paper transport path.

  Further, when the reading facing unit 70 is moved upward, the shutter 26 described above is closed, and the upper surface of the upper plate 72 of the reading facing unit 70 is in close contact with the shutter 26, and the white reference surface 76. Is configured not to be exposed.

  Further, when the reading facing unit 70 is moved downward, the above-described mylar 36 is advanced toward the reading window 20, and the sheet S (test paper) on the upper plate 72 is pressed to press the upper plate 72. It is designed to be held on the top surface.

  As described above, the light source 12, the contact image sensor 16, the solenoid that moves the shutter 26, the fan 24, the driving source of the reading counter unit 70, and the like that constitute the image reading apparatus 10 are connected to a control unit (not shown). This control part controls each operation | movement of each said part.

  The image reading apparatus 10 having the above configuration is applied to the image forming apparatus 38.

  Here, FIG. 5 schematically shows the configuration of the image forming apparatus 38. The image forming apparatus 38 is an apparatus that forms the above-described paper S by forming a color image on a predetermined paper K.

  The paper K is accommodated in a paper feed cassette 58 of the image forming apparatus 38 and fed out one by one by a pickup roller (not shown) provided on the paper K feed side of the paper feed cassette 58. The fed paper K is conveyed at a substantially constant speed by a predetermined number of roller pairs 60 along a conveyance path (a two-dot chain line portion in FIG. 5) formed so as to cross the inside of the machine body. Toner image formation for forming toner images of C (cyan), M (magenta), Y (yellow), and K (black) colors on the upper side of the conveyance path of the paper K with an intermediate transfer belt 41 described later. The portions 40A, 40B, 40C, and 40D are arranged at substantially equal intervals along the circulation path (described later) of the intermediate transfer belt 41.

  The toner image forming units 40A, 40B, 40C, and 40D have the same configuration except for the color of the toner image to be formed, and the photosensitive drum 42 is arranged so that the axis is orthogonal to the circulation direction of the intermediate transfer belt 41. It has. Around the photosensitive drum 42, a charger 44 for charging the photosensitive drum 42, and light (laser light in the present embodiment) is irradiated on the charged photosensitive drum 42 to electrostatic latent image A predetermined color toner is supplied to the electrostatic latent image forming portion on the photosensitive drum 42 and the electrostatic latent image is developed to form a predetermined color toner image on the photosensitive drum 42. A developing device 48 to be formed, a transfer device 50 disposed opposite to the photosensitive drum 42, a static eliminator (not shown) that neutralizes the photosensitive drum 42, a cleaner blade (not shown) for removing residual toner on the photosensitive drum 42, and Each of the cleaner brushes is arranged and configured. In addition, in each of the toner image forming units 40A, 40B, 40C, and 40D, there are a plurality of mirrors 64 that reflect the laser light emitted from the light exposure device 46 and guide it onto the peripheral surface of the photosensitive drum 42. Is provided.

  The toner image forming units 40A, 40B, 40C, and 40D form toner images of different colors on the peripheral surface of the photosensitive drum 42 by the charger 44, the light exposure device 46, and the developing unit 48, and then the toner images. Is transferred (primary transfer) onto an intermediate transfer belt 41 described later by the transfer unit 50. A series of processes of charging, exposure (electrostatic latent image formation), development (toner image formation), and transfer in each of the toner image forming units 40A, 40B, 40C, and 40D is performed in each of the toner image forming units 40A, 40B, 40C, and 40D. The execution timing is controlled so that the toner images formed in the above overlap on the intermediate transfer belt 41. As a result, a full-color toner image is formed on the intermediate transfer belt 41.

  The intermediate transfer belt 41 is provided below the toner image forming portions 40A, 40B, 40C, and 40D. The intermediate transfer belt 41 is an endless belt and circulates counterclockwise in FIG. The intermediate transfer belt 41 circulates while being held between the photosensitive drums 42 of the toner image forming units 40A, 40B, 40C, and 40D and the transfer units 50. On the intermediate transfer belt 41, the toner image forming unit is circulated. The toner images formed by 40A, 40B, 40C, and 40D are transferred and superimposed.

  The lower end portion of the circulation path of the intermediate transfer belt 41 intersects with the intermediate portion of the conveyance path of the paper K fed from the paper feed cassette 58 described above. A secondary transfer roller pair 62 is provided so as to sandwich the intermediate transfer belt 41 at a position where the circulation path of the intermediate transfer belt 41 and the conveyance path of the paper K intersect, and the secondary transfer roller pair 62 is fed into itself. The color image on the intermediate transfer belt 41 is collectively transferred (secondary transfer) to the sheet K by bringing the intermediate transfer belt 41 into pressure contact with the sheet K.

  A fixing unit 52 is disposed downstream of the secondary transfer roller pair 62 in the transport direction. The fixing unit 52 is provided with a heating roller 54 and a pressurizing endless belt 56 facing each other, and the paper K on which the toner image is transferred is sandwiched between the heating roller 54 and the pressurizing endless belt 56 to form a toner image. Is a heat fixing type fixing device that fixes the toner image onto the paper K by heating the forming surface and pressurizing the paper K. In this way, the sheet K on which the toner image is fixed is the sheet S described above.

  The image forming unit for forming the sheet S by forming an image on the sheet K by the image forming units 40A, 40B, 40C, and 40D, the intermediate transfer belt 41, the secondary transfer roller pair 62, and the fixing unit 52 as described above. 39 is configured.

  The image reading device 10 is disposed downstream of the image forming unit 39 (fixing unit 52) in the transport direction. The image reading apparatus 10 is built in the image forming apparatus 38 and reads the image on the paper S in the body of the image forming apparatus 38. In the image forming apparatus 38, a controller (not shown) determines the print quality of the paper S based on the read image (captured image), and the image forming process of the image forming apparatus 38 is appropriately performed according to the determination result. An instruction to perform (image quality adjustment instruction) is given to each toner image forming unit 40.

  A tension roller pair 61 is provided on the downstream side in the transport direction of the image reading apparatus 10, and the paper S feeding speed is somewhat higher than that of the roller pair 60. Thus, the tension roller pair 61 cooperates with the roller pair 60 immediately upstream in the transport direction to pull the paper S along the transport direction and remove the slack in the transport direction of the paper S.

  A discharge tray (not shown) is provided on the downstream side of the tension roller pair 61 in the conveyance direction, and the discharge tray receives the sheet S discharged from the body of the image forming apparatus 38.

  Next, the operation of the present embodiment will be described.

  First, in the image forming apparatus 38, a color image is formed on a predetermined sheet K, and a sheet S is produced.

  That is, the light exposure device 46 is operated, and laser light is emitted from the light exposure device 46 in accordance with the image data. The laser beam is reflected by the mirror 64 and forms an image on the photosensitive drum 42 charged by the charger 44. That is, the laser beam emitted from the light exposure device 46 is scanned on the photosensitive drum 42, whereby an electrostatic latent image is formed on the photosensitive drum 42. Next, the developing device 48 supplies toner of a predetermined color to the electrostatic latent image forming portion on the photosensitive drum 42 and develops the electrostatic latent image, whereby a toner image of the predetermined color is formed on the photosensitive drum 42. Is formed.

  This toner image is transferred (primary transfer) onto the intermediate transfer belt 41 by the transfer device 50. In this case, as the intermediate transfer belt 41 moves along the circulation path, the toner images of the respective colors are sequentially superimposed on the intermediate transfer belt 41 to form a full-color toner image.

  Next, the toner image formed on the intermediate transfer belt 41 is taken out from the paper feed cassette 58 and conveyed by the roller pair 60 at the pressure contact position of the secondary transfer roller pair 62 (position where the paper K is pressed). Transferred (secondary transfer) onto the paper K. The sheet K on which the toner image is transferred from the intermediate transfer belt 41 is conveyed to the fixing unit 52 by the roller pair 60, and is transferred from the intermediate transfer belt 41 to the sheet K by the heating roller 54 and the pressurizing endless belt 56. The toner image is heat-fixed.

  The sheet K on which the image is formed in this manner is the sheet S, and is conveyed to the image reading apparatus 10 by the roller pair 60.

  In the image reading apparatus 10, the reading facing unit 70 is provided so as to be movable up and down corresponding to the conveyance path, and the upper surface of the upper plate 72 constitutes a part of the conveyance path when moved downward, When moved upward, the upper surface of the lower plate 74 constitutes a part of the transport path.

  When the image reading device 10 reads an image on the sheet S, the image on the sheet S is read by the reading unit 28 (the lens array 30 and the contact image sensor 16). That is, as shown in FIG. 1, the reading facing unit 70 is moved downward, and the upper surface of the upper plate 72 constitutes a part of the transport path. It is pressed on the upper surface of the upper plate 72 by the mylar 36 as a member. Further, the image of the sheet S conveyed on the conveyance path and the white reference surface 76 of the upper plate 72 are read through the reading window 20 by the contact image sensor 16 accommodated in the housing 18. In this case, when the image is read by the contact image sensor 16 (that is, the reading facing unit 70 is moved downward), the conveyance path forms a test paper conveyance path, and the test paper is applied as the paper S.

  On the other hand, when the image is not read by the reading means 28 (the lens array 30 and the contact image sensor 16), the reading facing unit 70 is moved upward as shown in FIG. The upper plate 72 closes the reading window 20 of the housing 18 and the white reference surface 76 is separated and retracted from the conveyance path. In this case, when the image is not read by the contact image sensor 16 (that is, in a state where the reading facing unit 70 moves upward and the upper surface (white reference surface 76) of the upper plate 72 is separated from the conveyance path and retracted), the conveyance is performed. The path forms a print paper conveyance path, and the print paper is applied as the paper S.

  Moreover, when such an image is not read, the reading window 20 of the housing 18 is closed by the shutter 26 and the contact image sensor 16 is shielded from the outside. Further, in this state, the upper surface of the upper plate 72 of the reading facing unit 70 is in close contact with the shutter 26 and the white reference surface 76 is not exposed.

  Here, in the system for reading and inspecting by applying the image reading apparatus 10 as described above, the frequency of the inspection is, for example, several times a week. Since the output of the non-printed paper is from several hundred to several thousand, the upper surface of the lower plate 74 of the reading facing unit 70 in the upwardly moved state has such a normal output as schematically shown in FIG. When the image is printed (when the image is not read by the contact image sensor 16), dirt and dust are attached (indicated by reference numeral X in FIG. 4). On the other hand, during such normal printing, the upper surface (white reference surface 76) of the upper plate 72 of the reading facing unit 70 that has been moved upward as described above is separated from the conveying path and retracted. At the reading position (the upper surface of the upper plate 72 and the white reference surface 76), dirt and dust are less likely to occur. Further, dirt and dust are unlikely to occur at the image reading position, and the upper plate 72 closes the reading window 20 of the housing 18. ) Itself is hard to get dirty.

  Therefore, when the image is read by the reading unit 28, the contact image sensor 16 does not read an image with dirt or dust, and it is possible to prevent the image quality of the image read by the contact image sensor 16 from being deteriorated.

  Further, in the image reading apparatus 10, when the image is not read (that is, during normal printing, the reading facing unit 70 moves upward, and the upper surface (white reference surface 76) of the upper plate 72 is separated from the conveyance path. When the reading window 20 of the housing 18 is closed by the shutter 26, the reading means 28 (the lens array 30 and the contact image sensor 16) can be shielded from the outside. It is possible to more reliably prevent the sensor 16 itself from becoming dirty or adhering to dust.

  Furthermore, in this image reading apparatus 10, when the reading counter unit 70 moves upward, in other words, when the image is not read by the reading means 28 (that is, during normal printing, the upper surface of the upper plate 72 (white reference) When the shutter 26 is operated and the reading window 20 is closed in the state where the surface 76) is separated from the conveying path and retracted, the upper surface of the upper plate 72 of the reading facing unit 70 is in close contact with the shutter 26. Thus, the white reference surface 76 is not exposed. Therefore, not only can the lens array 30 and the contact image sensor 16 be reliably prevented from becoming dirty or dust, but also the upper surface (white reference surface 76) of the upper plate 72 can be more reliably prevented from being dirty or dust. Therefore, shading correction can be more reliably performed.

  In the image reading apparatus 10, the sheet S is pressed onto the upper surface of the upper plate 72 by the mylar 36 in a state where the reading facing unit 70 is moved downward (that is, when the contact image sensor 16 reads an image). For this reason, it is possible to prevent the reading accuracy from deteriorating because the brightness at the time of reading or the focus state does not change due to the floating of the sheet S (test paper) that is the object to be read.

  Further, in the image reading apparatus 10, when the image is read by the contact image sensor 16 (that is, in a state where the reading facing unit 70 is moved downward), the conveyance path forms a test paper conveyance path and the test paper is used as the paper S. When the image is not read by the contact image sensor 16 (that is, the reading facing unit 70 is moved upward and the upper surface (white reference surface 76) of the upper plate 72 is separated from the conveyance path and retracted), Since the transport path forms a print paper transport path and print paper is applied as the paper S, it is possible to share a transport path for normal print paper output and a transport path for test paper output during inspection. The apparatus can be made compact as a whole.

  As described above, the image reading apparatus 10 according to the present embodiment can maintain the inspection accuracy of the image quality (can prevent deterioration of the image quality of the captured image), and can be realized with a compact configuration.

1 is a schematic cross-sectional view showing the configuration of an image reading apparatus according to an embodiment of the present invention when an image is read. 1 is a schematic cross-sectional view illustrating a configuration of an image reading apparatus according to an embodiment of the present invention when an image is not read. 1 is a schematic perspective view showing a configuration of a reading facing unit of an image reading apparatus according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view corresponding to FIGS. 1 and 2 illustrating a state in which dirt and dust adhesion occurs in the image reading apparatus according to the embodiment of the present invention. 1 is a schematic diagram illustrating a configuration of an image forming apparatus to which an image reading apparatus according to an embodiment of the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image reader 12 Light source 16 Contact | adherence image sensor (imaging element)
18 Housing 20 Reading window 26 Shutter (shielding member)
28 Reading means 30 Lens array 36 Mylar (paper pressing member)
70 Reading Counter Unit 72 Upper Plate 74 Lower Plate 76 White Reference Surface S Paper

Claims (9)

In an image reading apparatus that reads an image of a sheet conveyed through a predetermined conveyance path by a reading unit,
A reading facing portion which is an image reading position by the reading unit and constitutes a part of the conveyance path is separated and retracted from the conveyance path when the image is not read by the reading unit;
An image reading apparatus. In a state where the reading facing portion constitutes a part of the transport path, a test paper is applied as the paper, and the transport path forms a test paper transport path,
In a state where the reading facing portion is separated and retracted from the transport path, print paper is applied as the paper, and the transport path forms a print paper transport path.
The image reading apparatus according to claim 1.   The image reading apparatus according to claim 1, further comprising a shielding member capable of shielding the reading unit from outside when the image is not read by the reading unit.   The image according to any one of claims 1 to 3, further comprising a sheet pressing member that presses the sheet and holds the sheet on the reading facing unit when the image is read by the reading unit. Reader. An image sensor that is housed in a housing is provided corresponding to a predetermined transport path, and reads an image of a sheet transported through the transport path by the image sensor through a reading window formed in the housing. Reading means;
An upper plate having a white reference surface on the upper surface and a lower plate provided to face the lower side of the upper plate, and is provided so as to be movable up and down corresponding to the transport path, and moved downward. Then, the upper surface of the upper plate constitutes a part of the transport path, and when it is moved upward, the upper surface of the lower plate constitutes a part of the transport path and the upper plate closes the reading window of the housing. A reading facing unit in which the white reference surface is separated and retracted from the conveyance path;
An image reading apparatus comprising: In the state where the reading facing unit moves downward, a test paper is applied as the paper, and the conveyance path forms a test paper conveyance path,
In the state where the reading facing unit moves upward, print paper is applied as the paper, and the transport path forms a print paper transport path.
The image reading apparatus according to claim 5.   The image reading apparatus according to claim 5, further comprising a shutter capable of closing a reading window of the housing. The shutter is in the reading window closed state when the reading facing unit is moved upward, and the upper surface of the upper plate of the reading facing unit is in close contact with the shutter so that the white reference surface is not exposed. ,
The image reading apparatus according to claim 7.   9. A sheet pressing member that presses the sheet and holds the sheet on the upper surface of the upper plate of the reading counter unit in a state where the reading counter unit moves downward. The image reading apparatus according to any one of the above.

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