JP2006259364A - Image reader and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image reader capable of suppressing an adverse influence on a photographed image by at least one of smudge such as dust and paper dust and dew condensation and an image forming apparatus capable of maintaining inspection precision of printing quality by providing the image reader. <P>SOLUTION: The image reader 10 has a light source 12, an imaging element 16, a housing 18 and a shutter 26. When an image of a sheet is not read, a reading window 20 is shut by the shutter 26. Thus, the housing 18 is made into a tightly sealed state and penetration of the smudge such as dust or paper dust from the outside of the housing 18 to the inside of the housing 18 is prevented. In addition, at the time of power application of the image forming apparatus 10, etc., the light source 12 is lit at a shut state of the reading window 20 by the shutter 26. Thus, the inside of the housing 18 is efficiently heated using the light source 12 as a heat source and generation of dew condensation in the inside of the housing 18 is prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus that reads an image formed on a sheet, and an image forming apparatus that performs an image forming process, and includes the image reading apparatus to inspect a quality of an image formed by the image forming process.

  An image reading apparatus that reads an image of a document has been proposed. The image reading apparatus includes a light source, and irradiates the original with light from the light source. In addition, the image reading apparatus includes an image pickup device (photoelectric conversion device) such as a CCD (Charge Coupled Device), and detects reflected light of the light irradiated on the document by the light source and converts it into an electric signal. An image processing unit is connected to the image sensor, and captured image data of a document is generated based on an electrical signal from the image sensor. The image sensor is housed in the housing together with the light source. The housing is opened on the propagation path side of the reflected light (on the optical axis side of the image sensor), and this opening portion faces the document placing table on which the document is placed. A contact glass capable of transmitting reflected light is attached to the opening of the housing, and closes the opening of the housing. The light emitted from the light source is applied to the document on the document table, the reflected light is transmitted through the contact glass, and the image sensor detects the reflected light and converts it into an electrical signal. Based on this electrical signal, image processing The captured image data is generated by performing image processing by the unit, and the captured image of the original is obtained.

  Here, in order to prevent and eliminate condensation inside the housing, an invention for warming the inside of the housing has been proposed, and examples thereof are disclosed in Patent Document 1 and Patent Document 2 below.

  An image reading apparatus according to the invention disclosed in Patent Document 1 is a fixed reading type that reads an original while placing the original on a contact glass and moving an optical scanning system including a light source relative to the original. It is an image reading apparatus. In the image reading apparatus of Patent Document 1, the light source is turned on when the power is turned on to increase the surface temperature of the components of the optical scanning system, thereby preventing condensation in the housing.

  Further, the image reading apparatus according to the invention disclosed in Patent Document 2 is a fixed-reading type image reading apparatus, similar to the image reading apparatus disclosed in Patent Document 1. The image forming apparatus of Patent Document 2 includes condensation detection means for detecting condensation, and when the condensation detection means detects condensation, the image forming apparatus positions the optical scanning system at the home position and in this state. Turn on the light source. That is, the optical system member near the home position is warmed to evaporate condensed water.

  In addition to the image forming apparatuses disclosed in Patent Document 1 and Patent Document 2, an invention for preventing dew condensation has been proposed, and an example thereof is disclosed in Patent Document 3 below.

  The image reading apparatus according to the invention disclosed in Patent Document 3 is also a fixed reading type image reading apparatus, and at the time of dew condensation prevention processing, the optical scanning system is reciprocated in the sub-scanning direction. This is a mechanism for preventing dew condensation by applying wind to the optical scanning system. Further, the image reading apparatus of Patent Document 3 further enhances the effect of preventing condensation by turning on the light source during the reciprocating movement of the optical scanning system.

  In addition, an invention has been proposed in which the light source is exposed to the wind without moving the optical scanning system as described above, and an example thereof is disclosed in Patent Document 4 below. The image reading apparatus according to the invention disclosed in Patent Document 4 includes an air blowing unit including a fan and a current plate. A rectifying plate is provided inside the housing, and rectifies the wind sent from the outside of the housing to the inside of the housing by a fan and changes the direction of the wind to the light source side. That is, the air blowing means composed of the fan and the rectifying plate prevents wind from directly hitting the light source. And the wind from a baffle plate is made to strike this light source uniformly over the scanning direction (longitudinal direction of a light source) of a light source.

  However, in the above-described image reading apparatuses of Patent Documents 1 to 4, if dirt such as dust or paper dust adheres to the contact glass, the image sensor reads the dirt together with the image of the paper, and the captured image It will adversely affect. In this case, it is conceivable to omit the contact glass, but there is a possibility that dirt such as dust or paper dust may enter the housing from the opening of the housing.

  Further, the mechanism for reciprocating the optical scanning system in the sub-scanning direction as in the image reading device of Patent Document 3 cannot be used in a flow reading method in which a document is read by a fixed optical imaging system while the document is being conveyed. There's a problem.

Further, the image reading apparatus of Patent Document 4 is not intended to prevent the occurrence of condensation inside the housing, but to suppress uneven irradiation of the paper by the light source, and is not necessarily effective in preventing condensation. . When the air outside the housing is sent into the housing by the fan, dirt such as dust and paper dust may enter the housing together with the air outside the housing. There is a possibility that the captured image may be adversely affected by adhering to the light receiving surface or light source of the element.
Japanese Patent Laid-Open No. 10-308553 Japanese Patent Laid-Open No. 10-290364 JP-A-10-142906 JP 2004-45506 A

  In view of the above problems, the present invention includes an image reading apparatus capable of suppressing an adverse effect on a captured image due to at least one of dirt such as dust and paper powder and dew condensation, and the print reading accuracy is improved by including the image reading apparatus. It is an object to obtain an image forming apparatus that can be maintained.

  An image reading apparatus according to claim 1 is an image sensor that reads an image formed on a sheet; a housing that houses the image sensor; and a reading window formed on the optical axis of the image sensor; A light source that is housed in the housing and is lit to irradiate the paper with light and warm the interior of the housing, and the reading window can be closed, and the reading window is closed to seal the housing. And a shutter.

  In the image reading apparatus according to the first aspect, the imaging element and the light source are accommodated in the housing. A reading window is formed in a portion of the housing on the optical axis of the image sensor. When the light source is turned on, the light is irradiated onto the paper, and the image formed on the paper is read by the image sensor. It is done. Also, here, the interior of the housing is warmed by turning on the light source, thereby preventing condensation from forming inside the housing.

  Here, the image reading apparatus is provided with a shutter so that the reading window of the housing can be closed. In a state where the reading window is closed by the shutter, the housing is sealed, and the light source is turned on so that the inside of the housing is more reliably warmed. Thereby, it can prevent more reliably that dew condensation arises inside a housing.

  Further, in this way, when the reading window is closed by the shutter, the inside of the housing is blocked from the outside of the housing by the shutter, so that dirt such as dust and paper dust can be prevented from entering the inside of the housing from the outside of the housing. .

  As described above, the image reading apparatus can prevent dew condensation from occurring inside the housing, and can prevent dirt such as dust and paper powder from entering the housing from the outside of the housing. It is possible to suppress adverse effects on the picked-up image due to condensation on the light receiving surface or the light source, or contamination such as dust or paper dust.

  An image reading apparatus according to a second aspect of the present invention is the image reading apparatus according to the first aspect, wherein the light source is lit in the closed state of the reading window by the shutter when the image sensor does not read the image. It is characterized by that.

  In the image reading apparatus according to the second aspect, when the image sensor does not read the image on the paper, the light source is turned on in a state where the reading window of the housing is closed by the shutter. For this reason, the inside of the housing can be warmed up in a short time with power saving. That is, the image reading apparatus according to the second aspect can efficiently warm the inside of the housing.

  According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect of the present invention, the color of the surface of the shutter on the image sensor side is a color that reflects light from the light source. It is characterized by being.

  In the image reading apparatus according to the third aspect, the color of the surface of the shutter on the image sensor side is a color that reflects light from the light source. For this reason, the inside of the housing is also warmed by the reflected light from the shutter. That is, the image reading apparatus according to the third aspect can efficiently warm the inside of the housing.

  According to a fourth aspect of the present invention, in the image reading device according to the third aspect, the surface of the shutter on the image sensor side of the shutter is a white reference plate for shading correction. .

  In the image reading apparatus according to the fourth aspect of the invention, since the surface on the image sensor side of the shutter is a white reference plate for shading correction, the shutter can also be used as a shading correction member. Multiple functions can be achieved.

  An image forming apparatus according to a fifth aspect of the present invention is an image forming apparatus including the image forming unit that forms an image on a sheet and the image reading device according to any one of the first to fourth aspects. The image reading apparatus is provided on the downstream side of the image forming unit in the sheet conveying direction, and the image of the sheet formed by the image forming unit is conveyed to the image reading apparatus to improve the quality of the image. It is characterized by inspecting.

  In the image forming apparatus according to the fifth aspect of the invention, since the image reading device is provided downstream of the image forming unit in the sheet conveying direction, the sheet on which the image is formed in the image forming unit is the image reading device. The image on the sheet is read by the image sensor of the image reading apparatus.

  Here, as described above, the image reading apparatus can prevent dirt such as dust and paper dust from entering the inside of the housing from the outside of the housing, and can prevent condensation from forming inside the housing. As a result, for example, a paper image formed by the image forming unit does not cause dirt such as dust or paper dust to adhere to the light receiving surface or light source of the image sensor, and condensation occurs on the light receiving surface or light source of the image sensor. Can be imaged without any problem. That is, since an adverse effect on the captured image due to at least one of dirt such as dust and paper dust and dew condensation can be suppressed, the image forming apparatus according to claim 5 improves the inspection accuracy of the image quality of the paper formed by the image forming unit. Can be maintained.

  As described above, the image reading apparatus according to the present invention has an excellent effect that an adverse effect on a captured image due to at least one of dirt such as dust and paper powder and dew condensation can be suppressed.

  In addition, the image forming apparatus according to the present invention has the excellent effect that the inspection accuracy of the print quality can be maintained by providing the image reading apparatus.

(First embodiment)
FIG. 1 shows an outline of an image reading apparatus 10 according to the first embodiment of the present invention. For example, the image reading apparatus 10 reads an image on the sheet 30 while conveying a sheet (for example, a document, a copy print, or the like) 30 on which an image is formed. Hereinafter, for convenience of explanation, in FIG. 1, the left side is the upstream side in the transport direction, and the right side is the downstream side in the transport direction.

  The image reading apparatus 10 includes a housing 18 having a substantially rectangular box shape. The housing 18 has a pair of side walls 32 and 34 facing each other. The pair of side walls 32, 34 are formed in a slope shape with lower portions approaching each other downward, and the housing 18 is somewhat tapered toward the lower side.

  A bottom wall 36 is integrally formed at the lower ends of the pair of side walls 32, 34. A central portion in the left-right direction of the bottom wall 36 is opened, and this opening portion serves as a reading window 20. The reading window 20 communicates the inside of the housing 18 with the outside.

  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. Such a light source 12 is, for example, a halogen lamp.

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

  An imaging element 16 is accommodated in the housing 18. The image sensor 16 corresponds to the center position of the reading window 20 and is disposed above the light source 12 and the mirror 14. The imaging element 16 faces a paper placement table 28 as a paper placement member, which will be described later, and its optical axis faces downward. The image pickup device 16 is a close-contact type line sensor using, for example, a CCD (Charge Coupled Device) or the like, and detects light propagating from below and converts it into an electrical signal.

  An image processing unit (not shown) is connected to the image sensor 16 and generates captured image data of an image of the paper 30 based on an electrical signal from the image sensor 16.

  A plate-like shutter 26 is attached to the bottom wall 36 of the housing 18 to close the reading window 20 of the housing 18 from the outside. The reading window 20 can be moved in the left-right direction along the lower surface of the bottom wall 36 by a solenoid (not shown) attached to the housing 18 (can be moved in a region on the right side of the position of the reading window 20 as a reference). (See FIG. 2). Accordingly, the reading window 20 is opened (hereinafter referred to as shutter 26 at this time) by moving the shutter 26 to the right side from the position (hereinafter referred to as the closing position) where the reading window 20 is closed by a solenoid or the like (not shown). The position is called the open position). In the present embodiment, the color of the surface of the shutter 26 on the image sensor 16 side is the color that reflects light from the light source 12 (for example, white).

  A paper placement table 28 is disposed below the housing 18. The paper mounting table 28 has a plate shape, and the paper 30 is placed on the upper surface thereof. The upper surface (paper placement surface) of the paper placement table 28 faces the light receiving surface of the image sensor 16. Thereby, the light emitted from the light source 12 and directly or indirectly (via the mirror 14) and applied to the paper 30 on the paper mounting table 28 is reflected to the image sensor 16 side.

  In the image reading apparatus 10 as described above, the above-described solenoid that moves the light source 12, the image sensor 16, and the shutter 26 is connected to a control unit (not shown), and the control unit is the light source 12, the image sensor. 16 and the operation of each of the solenoids that move the shutter 26 are controlled.

  In the present embodiment, when the image of the paper 30 is read, the control unit moves the shutter 26 from the closed position to the open position to open the reading window 20 and turns on the light source 12 to emit reflected light from the paper 30. The image sensor 16 receives light. When the image reading of the paper 30 is finished, the control unit moves the shutter 26 from the open position to the closing position to close the reading window 20 and turns off the light source 12 to turn off the image of the paper 30 by the image sensor 16. Finish reading. Further, immediately before reading the image of the paper 30 (in this embodiment, when the image of the paper 30 is not read, for example, when the image reading apparatus 10 is turned on or when the sleep mode is released), the control is performed. The unit maintains the reading window 20 in the closed state by keeping the shutter 26 in the closed position, and turns on the light source 12 for a predetermined time in this state.

  Next, the operation of the first exemplary embodiment of the present invention will be described.

  When the image reading device 10 reads an image on the paper 30, the state in which the paper 30 is placed on the upper surface of the paper placement table 28 and the image surface (the surface on which the image is formed) of the paper 30 faces upward (imaging). In the state of being on the element 16 side, the sheet 30 is conveyed along the sheet placing table 28 to the downstream side in the conveying direction.

  Here, the solenoid of the shutter 26 is driven by the control unit (the solenoid is turned on), the shutter 26 is moved from the closed position to the open position along the lower surface of the bottom wall 36 of the housing 18, and the reading window 20 is moved. Opened (see FIG. 2). At the same time, the light source 12 is turned on by the control unit and the paper 30 is irradiated with light. Since the reading window 20 is formed in a portion of the housing 18 on the optical axis of the image pickup device 16, the image pickup device 16 receives reflected light from the paper 30 disposed on the paper mounting table 28 and receives the paper. 30 images can be read. Here, the interior of the housing 18 is warmed by turning on the light source 12. Thereby, it can prevent that dew condensation arises in the housing 18 inside.

  Next, when the image reading of the paper 30 is finished, the solenoid of the shutter 26 is stopped by the control unit (the solenoid is turned off), and the shutter 26 is closed from the open position along the lower surface of the bottom wall 36 of the housing 18. The reading window 20 is closed (see FIG. 1). At the same time, the light source 12 is turned off by the control unit, and reading of the image on the paper 30 by the image pickup device 16 is completed. Here, since the reading window 20 of the housing 18 is closed by the shutter 26, dirt such as dust and paper powder can be prevented from entering the housing 18 from the reading window 20 side.

  By the way, immediately before the above-described image reading of the sheet 30 (when the image of the sheet 30 is not read, for example, when the image reading apparatus 10 is turned on or when the sleep mode is released), the control unit performs a shutter. The solenoid 26 is kept in a stopped state (the solenoid is kept in an off state), and the shutter 26 remains in the closed position, whereby the reading window 20 is kept in the closed state. Accordingly, the housing 18 is maintained in a sealed state. Moreover, in this state, the light source 12 is turned on for a predetermined time by the control unit. Here, since the color of the surface of the shutter 26 on the image pickup device 16 side is a color that reflects light from the light source 12 (for example, white), the light from the light source 12 is used as the image pickup device of the shutter 26. Reflected by the 16 side surface. Therefore, the inside of the housing 18 is warmed not only by the direct light from the light source 12 but also by the reflected light from the shutter 26.

  For the reasons described above, the interior of the housing 18 can be warmed up in a short time with power saving. That is, the image reading apparatus 10 can warm the interior of the housing 18 more reliably and efficiently. Thereby, it can prevent more reliably that dew condensation arises inside the housing 18.

  Further, in this state, when the reading window 20 is closed by the shutter 26, the interior of the housing 18 is shielded from the outside of the housing 18 by the shutter 26, so that dirt such as dust and paper dust is contaminated from the outside of the housing 18 to the inside of the housing 18. Can be prevented from entering.

  As described above, the image reading apparatus 10 can prevent condensation within the housing 18 and can prevent dirt such as dust and paper dust from entering the housing 18 from the outside of the housing 18. For this reason, for example, the image reading apparatus 10 causes condensation on the light receiving surface of the image sensor 16, the light source 12, the mirror 14, or the like. It is possible to suppress the adverse effect on the captured image due to the adhesion of dirt or the like.

  In the present embodiment, the color of the surface of the shutter 26 on the image sensor 16 side is the color that reflects the light from the light source 12 (for example, white). The surface on the image sensor 16 side may be, for example, a white reference plate for shading correction (of course, the color of the white reference plate is white). In this case, the shutter 26 can also be used as a shading correction member, and the multifunction of the shutter 26 can be achieved.

In the present embodiment, the image reading apparatus 10 has been described as reading an image on the sheet 30 being conveyed, but the present invention is not limited to this. The image reading apparatus 10 according to the present invention uses an image sensor 16 as an area sensor instead of a line sensor, and reads an image on the paper 30 without transporting the paper 30 placed on the paper placement table 28. (It may be a fixed reading type image reading apparatus).
(Second Embodiment)
Next, a second embodiment of the present invention will be described. In addition, about the location which has the same structure, the same effect | action, and the same effect as the above-mentioned 1st Embodiment of this invention, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  FIG. 3 shows an outline of the image forming apparatus 38 according to the present embodiment. The image forming apparatus 38 is an apparatus for producing the paper 30 described in the first embodiment by forming a color image on the paper 30A. The paper 30A 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 30A feed side of the paper feed cassette 58. The fed paper 30A 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. 3) formed so as to cross the inside of the apparatus. 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 sheet 30A 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 30 </ b> A fed out from the paper feed cassette 58 described above. A secondary transfer roller pair 62 is provided 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 sheet 30A intersect, and the secondary transfer roller pair 62 is fed into itself. By pressing the intermediate transfer belt 41 against the sheet 30A, the color image on the intermediate transfer belt 41 is collectively transferred (secondary transfer) to the sheet 30A.

  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 pressure endless belt 56 facing each other, and the toner image is sandwiched between the heating roller 54 and the pressure endless belt 56 by sandwiching the paper 30A onto which the toner image has been transferred. A fixing device of a heat fixing type that fixes the toner image on the paper 30A by heating the forming surface and pressurizing the paper 30A. The sheet 30A on which the toner image is fixed in this manner is the sheet 30 described above.

  The image reading apparatus 10 described in the first embodiment is disposed downstream of the 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 30 in the body of the image forming apparatus 38. In the image forming apparatus 38, based on the read image (captured image), a controller (not shown) determines the print quality of the paper 30 (for example, color change, density change, thin line formation, etc.) In accordance with the determination result, an instruction (image quality adjustment instruction) for properly performing the image forming process of the image forming apparatus 38 is given to each of the toner image forming units 40A, 40B, 40C, and 40D.

  A tension roller pair 61 is provided on the downstream side in the transport direction of the image reading device 10, and the paper 30 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 30 along the transport direction and remove the slack in the transport direction of the paper 30.

  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 paper 30 discharged from the body of the image forming apparatus 38.

  In the image forming apparatus 38 as described above, the toner image forming units 40A, 40B, 40C, and 40D, the intermediate transfer belt 41, the secondary transfer roller pair 62, and the fixing unit 52 form an image on the paper 30A. An image forming unit 39 for manufacturing 30 is configured.

  Next, the operation of the second exemplary embodiment of the present invention will be described.

  The light exposure device 46 operates, 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 30A is pressed). Transfer (secondary transfer) to the sheet 30A. The sheet 30A 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 30A by the heating roller 54 and the pressure endless belt 56. The toner image is heat-fixed.

  The sheet 30 </ b> A on which the image is formed in this way is the sheet 30 and is conveyed onto the sheet placing table 28 of the image reading apparatus 10 by the roller pair 60.

  Since the image reading device 10 is provided on the downstream side in the transport direction from the fixing unit 52 of the image forming unit 39, the image reading device 10 reads the image of the paper 30 produced by the image forming unit 39 by the imaging element 16. be able to.

  Here, in the present image forming apparatus 38, when the paper 30 is manufactured by performing the heat fixing process on the paper 30 by the fixing unit 52 of the image forming unit 39, the water of the paper 30A evaporates and water vapor is generated. As a result, the water vapor flows to the downstream side in the transport direction from the fixing unit 52 of the image forming unit 39, and there is a possibility that condensation occurs inside the housing 18. However, the image reading apparatus 10 can prevent dew condensation from occurring inside the housing 18 by using the light source 12 as a heat source as described in the first embodiment.

  In the image forming apparatus 38, when the image reading apparatus 10 does not read the image on the paper 30, the reading window 20 formed in the housing 18 is closed as described in the first embodiment. Therefore, it is possible to prevent dust, paper powder, and dirt such as toner on the conveyance path of the paper 30 from entering the housing 18 from the reading window 20.

  For the reasons described above, in the image forming apparatus 38, the image reading apparatus 10 may cause condensation on the light receiving surface of the imaging element 16, the light source 12, the mirror 14, etc. The image on the sheet 30 can be read without suffering from problems such as dust, paper dust, and dirt such as toner adhering to the mirror 14 and the like. Therefore, the image forming apparatus 38 can maintain the inspection accuracy of the image quality of the paper 30 produced by the image forming unit 39.

1 is a diagram illustrating an outline of an image reading apparatus according to a first embodiment of the present invention, and is a diagram illustrating a closed state of a reading window. It is a figure which shows the outline of the image reading apparatus in the open state of a reading window. It is a figure which shows the outline of the image forming apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image reader 12 Light source 16 Image pick-up element 18 Housing 20 Reading window 26 Shutter 39 Image formation part 52 Fixing part (image formation part)

Claims (5)

An image sensor for reading an image formed on paper;
A housing in which the image sensor is housed and a reading window is formed on the optical axis of the image sensor;
A light source that is housed in the housing and is lit to irradiate the paper with light and warm the interior of the housing;
A shutter provided so as to be able to close the reading window, and sealing the housing by closing the reading window;
An image reading apparatus comprising: When the image sensor does not read the image, the light source is turned on in the closed state of the reading window by the shutter.
The image reading apparatus according to claim 1. The color of the surface on the image sensor side of the shutter is a color that reflects light from the light source,
The image reading apparatus according to claim 1 or 2, wherein The surface on the image sensor side of the shutter was a white reference plate for shading correction,
The image reading apparatus according to claim 3. An image forming apparatus comprising: an image forming unit that forms an image on a sheet; and the image reading apparatus according to any one of claims 1 to 4.
The image reading device is provided downstream of the image forming unit in the paper conveyance direction, and the image of the paper formed by the image forming unit is conveyed to the image reading device to inspect the quality of the image.
An image forming apparatus.

Images