JP2014017766A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader capable of cleaning a translucent member so as to prevent such dust coming to a reading position of the translucent member from remaining and capable of cleaning a reference surface for shading correction.SOLUTION: There is provided means which, while brush bristles 98 functioning as a cleaning member which brushes a contact glass 74 functioning as the translucent member from the upstream side to the downstream side of document transportation passes through a circulating position where brush bristles 103 functioning as the cleaning member of a white reference surface 90C brushes and cleans the white reference surface 90C, retracts the brush bristles 103 from the brush bristles 98 so as to prevent the brush bristles 98 from coming into contact with the brush bristles 103.

Description

  The present invention relates to an image reading apparatus, and more particularly to an image reading apparatus that reads a document image by a so-called sheet-through method.

  In recent years, in view of user convenience, an image reading apparatus used in a copying machine or the like moves an optical system below a stationary document placed on a platen glass and reads an image of the document, An automatic document feeder (ADF) reads a document transported in the sub-scanning direction at the reading position on the upper surface of the contact glass, which is a light-transmitting member elongated in the main scanning direction, with an optical system stationary under the contact glass. Many models using the seat-through method have been introduced to the market.

When reading a document image by the sheet-through method, prior to the reading, the white reference surface of a white reference member having a white reference surface disposed at a position facing the optical system via the contact glass is read, and the result is obtained. The shading correction is performed based on the obtained image data.
By the way, in the sheet-through method in which a document is conveyed to a reading position, paper dust and wear pieces of rubber rollers, which are constituent members of ADF, and other dust are conveyed to and near the reading position, and contact glass and white Frequently adheres to the reference surface.

When dust adheres to the contact glass, black streak-like noise appears in the read image, and when dust adheres to the white reference surface, the image quality is deteriorated such that proper shading correction is not performed.
Therefore, Patent Document 1 discloses an image reading apparatus provided with means for cleaning a contact glass and a white reference surface.

The cleaning means of patent document 1 is demonstrated referring FIG.
An image reading sensor 302 is provided below a contact glass 300 having a strip shape in a direction perpendicular to the paper surface. A white roller 304 whose outer peripheral surface is a white reference surface is provided in parallel with the contact glass 300 at a position facing the reading sensor 302 through the contact glass 300. On the outer peripheral surface of the white roller 304, a sponge (first sponge) 306 elongated in the axial direction is attached as a contact glass cleaning member. On the other hand, an elongated sponge (second sponge) 308 is attached to a housing (not shown) as a white roller cleaning member in contact with the peripheral surface of the white roller 304 in parallel with the white roller 304.

  In the above configuration, when cleaning is performed, the white roller 304 is rotated in the direction of arrow C by a driving unit (not shown) until the first sponge 306 is rotated to the position indicated by the broken line, and then returned to the original state. Thereby, the first sponge 304 reciprocates and rubs the surface of the contact glass 300 to clean the surface of the contact glass 304, and the second sponge 308 rubs and cleans the range indicated by the symbol E of the white roller 304. . When the cleaning is completed, the outer peripheral surface portion cleaned by the white roller 304 is positioned at the image reading position.

  Then, after the shading correction is performed, the document is conveyed in the direction of the arrow F and the image is read.

JP 2002-64686 A

However, in the image reading apparatus of Patent Document 1, when the first sponge 306 moves backward, there is a possibility that dust is returned to the upstream side in the document transport direction. As a result, the dust may return to the reading position due to the conveyed document.
In order to cope with this, the white roller 304 may be rotated once to eliminate the backward movement of the first sponge 306. However, the first sponge 306 interferes with the second sponge 308, and If the second sponge is removed, the white reference surface cannot be cleaned.

  In view of the above-described problems, the present invention can clean the surface of a translucent member so as not to leave dust that arrives at the reading position as compared with the conventional image reading apparatus, and also provides a reference plane for shading correction. An object of the present invention is to provide an image reading apparatus capable of cleaning the above.

  In order to achieve the above object, an image reading apparatus according to the present invention conveys a document in the sub-scanning direction and passes the reading position defined in the main scanning direction through a light-transmitting member with respect to the reading position. A sheet-through type image reading apparatus that reads an original image by a reading means arranged in a manner that is rotatable about a rotation axis along the main scanning direction, and has an outer peripheral surface along the rotation direction. When divided into the first area and the second area, a rotating body having a reference surface for shading correction of the reading means in the first area, and a second area of the rotating body are provided. The first cleaning member that cleans the translucent member by rubbing the translucent member from the upstream side to the downstream side in the document transport direction by the circular movement by rotation, and the reference that moves by the rotation of the rotating body The reference plane A second cleaning member that cleans the reference surface by rubbing at a second angular position different from the first angular position that faces the translucent member, and a first cleaning member that orbitally moves are at least A retracting means for retracting one of the first cleaning member and the second cleaning member from the other so that the first cleaning member does not come into contact with the second cleaning member while passing through the rotation position corresponding to the second angular position. And.

Further, when the outer peripheral surface is further divided into the third region in the rotation direction in addition to the first and second regions, the third region is opposed to the translucent member during document image reading. When the rotating body is at the home position, the second cleaning member is in contact with the reference surface so as to cover the reference surface.
In this case, the rotating body is rotated while the document image is not read, the first cleaning member cleans the light transmitting member, and the retracting means is interlocked with the rotation of the rotating body. The second cleaning member is retracted from the first cleaning member by separating the second cleaning member from the reference surface, and the second cleaning member rubs the reference surface during the separation. And cleaning the reference surface.

  Further, when the outer peripheral surface is further divided into the third region in the rotation direction in addition to the first and second regions, the third region is opposed to the translucent member during document image reading. The rotating body is positioned at a position, and the rotating body is rotated during a standby period when reading of the original image is not performed. The first cleaning member cleans the translucent member, and the retracting means rotates the rotating body. The second cleaning member is retracted outside the orbit of the first cleaning member that moves around during the rotation of the rotating body N times (N is a positive integer).

Further, the retracting means retracts the second cleaning member outside the orbit of the first cleaning member during reading of the document image, and cancels the retracting during standby when the document image is not read. The second cleaning member is brought into contact with the reference surface to have a retracting release means for cleaning the reference surface.
In this case, the rotating body is rotated during the standby, the first cleaning member cleans the translucent member, and the evacuation releasing means is operated in conjunction with the rotation of the rotating body. It has a mechanism for bringing a cleaning member into contact with the reference surface.

Alternatively, an image reading unit capable of reading an image of a document placed on the platen glass by attaching an automatic document transport unit that transports the document in the sub-scanning direction to an apparatus main body having a platen glass so as to be opened and closed. A device,
The evacuation is released in conjunction with the opening operation of the automatic document feeder, and the evacuation of the second cleaning member is performed in conjunction with the closing operation.

Alternatively, the rotating body and the second cleaning member are provided in a movable frame attached to the main body frame so as to be openable and closable, and the withdrawal is released in conjunction with the opening operation of the movable frame. The retracting of the second cleaning member is performed in conjunction with the closing operation.
In addition, the second cleaning member is fixed at a position that slidably rubs the reference surface that rotates around the rotation body by the rotation of the rotation body. As the first cleaning member passes through the rotation position corresponding to the second angular position, the first cleaning member is moved so that the first cleaning member does not come into contact with the second cleaning member. Proximity to the second region, and while the first cleaning member passes the first angular position, the first cleaning member is separated from the second region so that the light transmissive member can be rubbed. And

  Further, when the outer peripheral surface is further divided into the third region in the rotation direction in addition to the first and second regions, the third region is opposed to the translucent member during document image reading. When the rotating body is positioned at the home position, the outer peripheral surface of the second cleaning member extends from the second angular position to the first angular position in the rotational direction of the rotating body. It is in contact with the part.

In addition, the driving unit includes: a driving unit that rotationally drives the rotating body; a control unit that controls the driving unit; and a receiving unit that receives a cleaning instruction for the translucent member from a user. When the means accepts the cleaning instruction, the driving means is controlled to rotate the rotating body.
In addition, the driving unit includes: a driving unit that rotationally drives the rotating body; a control unit that controls the driving unit; and a receiving unit that receives a cleaning instruction for the translucent member made from an external device. When the receiving unit receives the cleaning instruction, the driving unit is controlled to rotate the rotating body.

A driving unit that rotates the rotating body; a control unit that controls the driving unit; and a counting unit that counts the number of documents passing through the reading position. The control unit includes the counting unit. Each time the predetermined number of sheets is counted, the driving means is controlled to rotate the rotating body.
The first cleaning member is formed of a sponge, a brush or other flexible material,
The second cleaning member is formed of a flexible material such as a sponge, a brush, or the like.

  According to the image reading apparatus having the above configuration, the translucent member is cleaned by the first cleaning member that rubs the translucent member from the upstream side to the downstream side in the document transport direction. Since the first cleaning member does not sweep back the dust to the upstream side in the conveyance direction of the document, the first cleaning member can be cleaned so that dust that reaches the reading position on the surface of the translucent member does not remain as compared with the conventional image reading apparatus. .

  Further, the first cleaning member moves to the second cleaning member while the first cleaning member that moves around passes at least the second rotation position corresponding to the second angular position where the second cleaning member slides and cleans the reference surface. Since one of the first cleaning member and the second cleaning member is withdrawn from the other so as not to contact, the two cleaning members do not interfere with each other.

1 is a perspective view showing an external appearance of a multifunction machine. It is a figure which shows schematic structure of the image reader part in the said multifunctional device. FIG. 4 is an enlarged view of a second document reading unit and its vicinity in the image reader unit. (A) is a side view of the white roller seen from the axial direction, and (b) is a perspective view of the white roller. FIG. 5A is a side view of the white reference surface cleaning unit viewed from the axial direction of the shaft, and FIG. 5B is a perspective view of the white reference surface cleaning unit. It is the figure which looked at the state in which the said white roller and the said white reference plane cleaning means were arranged in parallel from the axial direction of the shaft which is these structural members. (A) is a figure which shows schematic structure of the main control part which the said multifunctional machine has, (b) is a figure which shows a part of structure of the control part which the said image reader part has. It is a figure which shows the flowchart of the main routine which concerns on the rotation control program of the motor which is a rotation drive source of the said white roller. It is a figure which shows the flowchart of the subroutine which concerns on a home position return process in the said main routine. It is a figure which shows the flowchart of the subroutine which concerns on the process at the time of the shading correction | amendment in the said main routine. It is a figure which shows the flowchart of the subroutine which concerns on the process at the time of the cleaning in the said main routine. In Embodiment 2, it is the figure which looked at the white roller and its vicinity from the axial center direction of the shaft of a white roller. (A), (b) is the figure which looked at the white roller and its vicinity from the axial direction of the shaft of a white roller in Embodiment 3, (c) is the white reference surface cleaning in Embodiment 3. It is a perspective view of a means. (A) is a perspective view of the white reference surface cleaning means in Embodiment 4, (b) is a perspective view showing the one end part side of a white roller. It is the figure which looked at the white roller in Embodiment 4, and its vicinity from the axial center direction of the shaft of a white roller. FIG. 10 is a diagram illustrating a schematic configuration of a scanner and its vicinity in a fifth embodiment. FIG. 16 is a diagram illustrating a schematic configuration of a scanner and its vicinity in a sixth embodiment. (A) is a perspective view of a white roller in Embodiment 7, and (b) is a perspective view of a white reference surface cleaning means or the like. It is the figure which looked at the state in which the white roller and the white reference surface cleaning means were provided in parallel in Embodiment 7 from the longitudinal direction of the white roller. It is a figure for demonstrating a prior art.

Hereinafter, an example in which the embodiment of the image reading apparatus according to the present invention is applied to an image reader unit of a multifunction peripheral (MFP) having a copy function, a printer function, a facsimile function, and a network scan function will be described. This will be described with reference to the drawings. In addition, the scale between members is not unified in each figure.
<Embodiment 1>
FIG. 1 is a perspective view showing the appearance of the multifunction device 2.

The multifunction device 2 is roughly composed of an image reader unit 4 that reads a document image and a printer unit 6 that prints and reproduces the read image on a recording sheet.
The image reader unit 4 is configured to be able to read a document image by both a sheet-through method that is one of fixed optical systems and a mirror moving method that is one of moving optical systems. Here, the sheet-through method is a method in which an original is moved and read while the optical system is stationary (fixed). In the mirror movement method, the document is kept stationary, the mirror that guides the reflected light from the document surface to the CCD sensor is moved relative to the document, and the optical path length from the document reading position to the CCD sensor is always maintained constant. This is a reading method.

The image reader unit 4 includes an automatic document feeder (ADF) 8 for realizing the sheet-through method.
The automatic document feeder 8 separates documents one by one from a bundle of documents set on a document feed tray 10, passes the document reading position, which will be described later, and discharges it to a document discharge tray 12. . An image of a document passing through the document reading position is read by a first document reading unit 30 and a second document reading unit 32 described later.

  The printer unit 6 prints and reproduces the image read by the first document reading unit 30 and the second document reading unit 32 as a toner image on a recording sheet by a known electrophotographic method. The printer unit 6 has a three-stage paper feed cassette 14 provided for each recording sheet size at the lower part of the apparatus, and a recording sheet of a desired size is fed out from the corresponding paper feeding cassette, and a toner image is transferred to this. After being formed, it is discharged to the recording sheet discharge tray 16. The printer unit 6 is connected not only to the image read by the first document reading unit 30 and the second document reading unit 32 but also to the multifunction device 2 via the network interface unit 122 (FIG. 7A). Based on an electronic document received from a terminal device (not shown) such as a personal computer, the image is printed on a recording sheet.

  The multi-function device 2 also includes an operation panel 18 in a place where it can be easily operated at the front of the apparatus. The operation panel 18 has various keys in addition to the liquid crystal touch panel 20. The liquid crystal touch panel 20 displays a copy condition and copy mode being set, a key for selecting the copy condition and the copy mode, and a message such as out of paper or paper jam. The copy mode includes a single-sided reading mode for reading only the front surface (first surface) of the document, and a double-sided reading mode for reading the front surface (first surface) and the back surface (second surface) of the document with a single sheet passing. .

The various keys include a numeric keypad 22 for setting the number of copies, a clear key 24 for resetting the number of copies to “1”, and a copy start key 26 for accepting the start of copying. Further, the operation panel 20 has a cleaning key 28 for accepting a cleaning instruction for a contact glass 74 described later from a user.
FIG. 2 shows the configuration of the image reader unit 4 that is an image reading apparatus. The image reader unit 4 includes a first document reading unit 30 for surface reading in order to realize a function of reading the front surface (first surface) and the back surface (second surface) of the document with a single sheet passing. And a second document reading unit 32 for reading the back side.

The uppermost document in the document bundle D set on the document feed tray 10 is separated from the document bundle D by the pickup roller 34 and the separating roller pair 36 and conveyed to the registration roller pair 40 through the intermediate roller pair 38. The
The original is corrected in skew (skew) by the intermediate roller pair 38 and the registration roller pair 40, and then conveyed to the contact glass 44 of the first original reading unit 30 by the registration roller pair 40 and the first conveyance roller pair 42. Is done. The document that has passed through the contact glass 44 is transported directly below the second document reading unit 32 by the second transport roller pair 46. The document that has passed through the second document reading unit 32 is discharged to the document discharge tray 12 by the third conveyance roller pair 48 and the discharge roller 50. The contact glass 44 is made of a plate-like glass elongated in the main scanning direction (direction perpendicular to the paper surface), which is an example of a translucent member. In addition, you may comprise a translucent member using the plastics which have not only glass but translucency.

  The surface (first surface) of the document passing through the contact glass 44 of the first document reading unit 30 is irradiated by the light source 54 of the scanner 52 that is stationary below the contact glass 44. The reflected light from the document surface is changed in path by the first mirror 56, the second mirror 58 and the third mirror 60, and is imaged on the first line sensor 64 by the imaging lens 62. The first line sensor 64 is composed of a CCD (Charge Coupled Device) in which a plurality of photoelectric conversion elements are arranged along the main scanning direction.

  The first line sensor 64 converts the formed optical image into an image signal and outputs the image signal to the image processing unit 66. The image processing unit 66 performs analog processing, A / D conversion, shading correction, image compression processing, and the like on the input image signal to generate digitized image data, which is processed by a main control unit 112 (described later). Output to FIG. The image data is temporarily stored in the image memory 120 (FIG. 7) of the main control unit 112.

  A white roller 68 is provided immediately above the contact glass 44 of the first document reading unit 30. The white roller 68 is used not only for cleaning the surface of the contact glass 44 but also as a white reference surface for shading correction. The white roller 68 is a white roller provided for the second document reading unit 32. 86 (FIG. 4), the description of the white roller 86, which will be described in detail later, will be replaced with the description of the white roller 68.

In addition to the contact glass 44 for sheet through, a platen glass 70 for manually placing a document is provided at a position facing the automatic document feeder 8.
As described above, when a document is read by the sheet-through scanning method, the scanner 52 is at the position shown in FIG. 2 below the contact glass 44 (below the reading position), and at this position by the automatic document feeder 8. The original conveyed in the sub-scanning direction is irradiated and the original image is read.

On the other hand, when the document is placed on the platen glass 70 for manual placement and read (when the mirror moving method is used), the automatic document feeder 8 is opened upward, and the document is placed on the platen glass 70 for manual placement. Set to.
The automatic document feeder 8 is generally attached to an apparatus main body located below the automatic document feeder 8 so as to be freely opened and closed. On the main body side, an open / close detection switch (not shown) pressed by a part of the automatic document feeder 8 is provided. ) Is attached. That is, when the automatic document feeder 8 is closed, the open / close detection switch is pressed by a part of the automatic document feeder 8 to be turned on, and when the automatic document feeder 8 is opened, the open / close detection switch is turned off. Thus, the open / close state of the automatic document feeder 8 can be detected.

  In the case of the mirror movement method, the scanner 52 is moved rightward in FIG. At this time, the second mirror 58 and the third mirror 60 are paired and move in the same direction as the scanner 52 at a speed that is half of the moving speed. Is kept constant, and the reflected light of the original is imaged on the light receiving surface of the first line sensor 64. The reflected light of the document is photoelectrically converted into an image signal by the first line sensor 64, subjected to the same processing as described above by the image processing unit 66, and then output to the printer unit 6.

As described above, the image reader unit 4 can read the front surface (first surface) of the document by the sheet-through method or the mirror moving method.
When both sides of a document are read with a single pass, the document is read by the second document reading unit 32 in addition to the first document reading unit 30 while the document is conveyed by the automatic document conveying device 8.
FIG. 3 shows an enlarged view of the second document reading unit 32 and the vicinity thereof.

The second document reading unit 32 includes a scanner 72 serving as a reading unit. The scanner 72 has a contact glass 74. The contact glass 74 is made of a plate-like glass elongated in the main scanning direction (direction perpendicular to the paper surface), which is an example of a translucent member. In addition, you may comprise a translucent member using the plastics which have not only glass but translucency.
A pair of light sources 76 and 78 and a second line sensor 80 are provided above the contact glass 74. The second line sensor 80 includes a CIS (Contact Image Sensor) in which a plurality of photoelectric conversion elements are arranged along the main scanning direction.

  A movable frame 82 is provided below the second document reading unit 32. The movable frame 82 is pivotally supported by a shaft 84 fixed to a housing (not shown) of the automatic document feeder 8. The upper surface of the movable frame 82 functions as a guide surface for a document conveyed in the state shown in FIG. 3, and creates a part of the document conveyance path TP indicated by a one-dot chain line. When a document to be conveyed is jammed in the document conveyance path portion in which the movable frame 82 exists (so-called jam occurs), the movable frame 82 is attached to the shaft with the entire automatic document conveying device 8 opened upward. Since the document transport path TP is exposed by rotating counterclockwise around 84, the document can be easily removed from the document transport path TP.

The movable frame 82 includes one (lower) second transport roller 46A constituting the second transport roller pair 46 and one (lower) third transport roller 48A constituting the third transport roller pair 48. Is supported rotatably.
A white roller 86 provided at a position facing the second line sensor 80 via the contact glass 74 is supported on the movable frame 82 so as to be rotatable about a rotation axis along the main scanning direction. Yes. The white roller 86 is provided with a white reference surface cleaning means 88 for cleaning a white reference surface described later of the white roller 86.

FIG. 4A shows a side view of the white roller 86 viewed from the axial direction, and FIG. 4B shows a perspective view of the white roller 86.
The white roller 86 has a main body 90 which is a rotating body having a shape obtained by partially cutting the outer peripheral surface of a cylindrical member with a plane parallel to the central axis (so-called D-cut). The outer peripheral surface of the main body 90 has a flat surface 90A that is a region that appears by the cutting and a circumferential surface 90B that is a remaining region. The main body 90 is entirely white and is made of synthetic resin.

  Of the circumferential surface 90B, an outer peripheral surface area indicated by reference numeral 90C is an area that becomes a white reference surface to be read by the second document reading unit 32 during shading correction (hereinafter, this area is referred to as "white reference surface" 90C "), an outer peripheral surface area indicated by reference numeral 90D is an area serving as a guide surface of the document conveyed when the document image is read (hereinafter, this region is referred to as" guide surface 90D ").

The main body 90 is provided with a shaft 92 concentrically with the central axis of the columnar member, and a part thereof protrudes from both ends.
A brush 94 for cleaning the contact glass 74 is provided on the flat surface 90 </ b> A of the main body 90. The brush 94 is formed by planting brush hairs 98 as cleaning members on a base 96 made of an elongated plastic plate. The bristles 98 are planted in a straight line in the longitudinal direction of the main body 90. In the brush 94, the base 96 is fixed to the flat surface 90A with an adhesive (not shown) or the like. The tip of the bristle 98 protrudes beyond the virtual circumferential surface (FIG. 4A) indicated by the alternate long and short dash line that extends the circumferential surface 90B of the main body 90.

A spur gear 106 is attached to one end of the shaft 92 as shown in FIG. In FIG. 4A, the spur gear 106 is not shown.
FIG. 5A shows a side view of the white reference surface cleaning means 88 viewed from the axial direction of the shaft 100, and FIG. 5B shows a perspective view of the white reference surface cleaning means 88.
The white reference surface cleaning means 88 has a shaft 100. The shaft 100 is joined with a holding member 102 made of a long angle member having a cross-sectional shape of “L”. One end of the holding member 102 in the cross section is joined to the shaft 100 over its entire length. In addition, the bristle 103 as a cleaning member is planted on the other end portion of the holding member 102 over the entire length of the other end portion as a base material, and the brush 104 for cleaning the white reference surface 90C is configured. Has been.

A spur gear 108 is attached to one end of the shaft 100 of the white reference surface cleaning means 88.
In the white roller 86 and the white reference surface cleaning means 88, the shaft 92 and the shaft 100 are arranged in parallel with each other.
FIG. 6 shows a state in which the white roller 86 and the white reference surface cleaning means 88 are arranged side by side as viewed from the axial direction of the shafts 92 and 100 and the side where the spur gears 106 and 108 are not provided. In FIG. 6 and subsequent figures, the white reference surface 90C portion of the main body 90 of the white roller 86 is represented by a thick solid line.

  The spur gear 108 and the spur gear 106 are engaged with each other. The spur gear 106 and the spur gear 108 are gears having the same specifications. That is, the rotation ratio of the spur gear 108 to the spur gear 106 is 1, and when the spur gear 106 makes one revolution, the spur gear 108 meshed with it also makes one revolution. Therefore, when the main body 90 of the white roller 86 makes one rotation, the brush 104 of the white reference surface cleaning unit 88 makes one rotation around the shaft 100.

  In this case, as shown in FIG. 6B, when the guide surface 90D of the main body 90 of the white roller 86 is in a rotational position facing the contact glass 74 of the scanner 72, the white reference surface cleaning means 88 The meshing relationship between the spur gear 106 and the spur gear 108 is adjusted so that the bristles 103 of the brush 104 are in a rotational position that covers the white reference surface 90 </ b> C of the main body 90.

  Here, the rotation position of the white roller 86 shown in FIG. 6B where the guide surface 90D of the main body 90 of the white roller 86 is at the rotation position (angular position) facing the contact glass 74 of the scanner 72 is “home”. It will be referred to as “position”. In this example, whenever the white roller 86 is at the home position, the brush hair 103 of the brush 104 of the white reference surface cleaning means 88 covers the white reference surface 90C. The bristles 103 of the brush 104 of the white reference surface cleaning means 88 are pressed against the white reference surface 90C and cover the white reference surface 90C in a bent state.

  The white roller 86 is rotationally driven by rotational power transmitted through a power transmission mechanism (not shown) from a stepping motor (not shown in FIG. 7 (b)) in FIG. In this case, a detection sensor 110 for detecting that the white roller 86 is at the home position is provided in the vicinity of the white roller 86 (FIG. 3). As the detection sensor 110, for example, a transmission type optical sensor in which a light emitting unit and a light receiving unit are provided to face each other is used. In addition, a disc (not shown) is provided at the end of the white roller 86 opposite to the side where the spur gear 106 is attached, and a small hole is formed in the vicinity of the outer periphery of the disc. (Not shown). Therefore, when the white roller 86 rotates, the detection hole formed in the disk rotates in a circular orbit. The detection sensor 110 is installed so that the light-emitting portion and the light-receiving portion face each other across the detection hole passage position (a part of the circular orbit), so that the detection hole that rotates can be detected. It has become. The positional relationship between the detection sensor 110 and the detection hole is adjusted so that the white roller 86 is at the home position when the detection sensor 110 detects the detection hole.

  Therefore, it is possible to determine whether or not the white roller 110 is at the home position by referring to the detection result of the detection sensor 110, and thus the white roller 110 can be stopped at the home position. Further, by controlling the rotation angle of the stepping motor from the home position, the white reference surface 90C of the main body 90 of the white roller 110 is stopped at the rotation position (angular position) facing the contact glass 74 of the scanner 72. You can also. Here, the rotation position of the white roller 110 where the white reference surface 90C faces the contact glass 74 of the scanner 72 is referred to as a “shading correction position”.

The white roller 86 is at the home position shown in FIG. 6B when reading a document image and in a standby state where the image reader unit 4 is not operated.
When cleaning the contact glass 74, the white roller 86 is rotated only in one direction of the arrow A (clockwise in FIG. 6). Along with this, the shaft 100 of the white reference surface cleaning means 88 is rotated in the direction of arrow B (counterclockwise in FIG. 6), and the brush 104 is separated from the main body 90 of the white roller 86 and further away from the main body 90. .

As a result, as shown in FIG. 6A, the brush 104 of the white reference surface cleaning means 88 is withdrawn from the circular movement path (rotation path) of the brush bristles 98 of the white roller 86. Is prevented from colliding with (contacting) the brush 104.
That is, a spur gear 106 attached to the shaft 92, a spur gear 108 meshing with the spur gear 106, a shaft 100 to which the spur gear 108 is attached, and a holding member joined to the shaft 100 and holding the brush hair 103 102 is configured to save the bristle 103 so as not to come into contact with the bristle 98 moving around.

  When the white roller 86 is further rotated from the state shown in FIG. 6A, the brush bristles 98 are directed in the same direction as the document is conveyed during image reading (that is, upstream in the document conveyance direction). As shown in FIG. 6C, the original reading position on the surface of the contact glass 74 and the vicinity thereof are rubbed. Thereby, the dust adhering to the surface of the contact glass 74 is swept out. In addition, since the dust is swept from the upstream side toward the downstream side in the document transport direction, the swept dust hardly returns to the document reading position on the surface of the contact glass 74 and the vicinity thereof again. Therefore, it is possible to prevent the read image from being deteriorated as much as possible due to the dust once swept out.

  At the time of shading correction, the white roller 86 is moved from the home position shown in FIG. 6B to a position where the white reference surface 90C of the main body 90 faces the contact glass 74 as shown in FIG. (Shading correction position). When the bristle 103 of the white reference surface cleaning means 88 is separated from the white reference surface 90C of the main body 90, the white reference is vigorously restored by restoring the brush bristle 103 that has been in contact with the white reference surface 90C. The white reference surface 90C is cleaned by rubbing the surface 90C. However, the white reference surface 90C is covered with the brush bristles 103 of the white reference surface cleaning means 88 during reading or standby of the document image, so that dust is difficult to adhere. In other words, the white reference surface cleaning unit 88 functions not only as a white reference surface cleaning unit of the literal white reference surface 90C but also as a dustproof unit that prevents dust from adhering to the white reference surface 90C.

FIG. 7A is a diagram illustrating an outline of the main control unit 112 included in the multifunction machine 2.
As shown in the figure, the main control unit 112 has a configuration in which a ROM 116, a RAM 118, and an image memory 120 are connected to the CPU 114 with a CPU 114 as a center. The CPU 114 is connected to each of the CPUs of the image reader unit 4, the printer unit 6, and the operation panel 18 described above. The CPU 114 is connected to an external device such as a personal computer via the network interface unit 122 so as to be communicable.

The ROM 116 stores a control program executed by each CPU.
The RAM 118 stores copy conditions such as the number of copies set via the operation panel 18.
As described above, the image memory 120 temporarily stores the image data output from the image reader unit 4.

The CPU 114 controls the operation panel 18, the image reader unit 4, and the printer unit 6 as a whole to realize a smooth copy operation and the like.
FIG. 7B is a diagram illustrating a part of the configuration of the control unit 124 included in the image reader unit 4. The control unit includes a CPU 126 connected to the CPU 114 (FIG. 7A) of the main control unit 112.

  Connected to the CPU 126 are a motor drive unit 130 that controls the drive of a motor 128 that is a rotational power source of the white roller 86, and a detection sensor 110 (FIG. 2). In this example, a stepping motor is used as the motor 128. The CPU 126 activates the motor 128 and rotates the white roller 86 in accordance with an instruction from the CPU 114 for the shading correction or an instruction from the user input from the operation panel 18 and received via the CPU 114. To control.

The motor control program executed by the CPU 126 will be described with reference to the flowcharts shown in FIGS.
The program according to the flowchart shown in FIG. 8 is a main routine for motor control. The program is activated when the multifunction device 2 is turned on (YES in step S1).

  The CPU 126 refers to the detection result of the detection sensor 110 and determines whether or not the rotation position of the white roller 86 is at the home position. If it is not at the home position, a home position return process is performed (step S3), and if it is at the home position, the process proceeds to step S4. In step S4, the rotational position changing process of the white roller 86 for shading correction is performed as necessary. In the subsequent cleaning process, rotation control of the white roller 86 for cleaning the contact glass 74 and the white reference surface 90C is performed as necessary. Until the power of the multifunction device 2 is turned off (YES in step S6), the processes in steps S4 and S5 are executed as necessary.

Details of steps S3 to S5 will be described below.
FIG. 9 shows a flowchart of a subroutine related to the home position return process. The CPU 126 controls the motor driving unit 130 to activate the motor 128 (step S31). Since the white roller 86 is rotated by the rotation of the motor 128, the motor 128 is stopped after the detection result of the detection sensor 110 is turned on (YES in step S32) (step S33). As a result, the white roller 86 is positioned at the home position (FIG. 6B).

FIG. 10 shows a flowchart of a subroutine related to the shading correction process. The subroutine is activated when an instruction is received from the CPU 114 (FIG. 7) (YES in step S41).
The CPU 126 (FIG. 7) activates the motor 128 (step S42), counts the driving pulses of the motor 128 that is a stepping motor, and whether or not the number of pulses has reached a predetermined P (P is a positive integer). Is determined (step S43). Here, P is the number of drive pulses required for the white roller 86 to rotate from the home position to the shading correction position.

When the drive pulse reaches P (YES in step S43), the motor 128 is stopped. Thereby, the white roller 86 is positioned at the shading correction position (FIG. 6A).
In this state, waiting for the reading of the white reference plane 90C by the scanner 72 (FIG. 3) to end (YES in step S45), the motor 128 is restarted (step S46), and the detection result of the detection sensor 110 is turned on. The motor 128 is stopped (step S48), and the white roller 86 is returned to the home position (FIG. 6B).

FIG. 11 shows a flowchart of a subroutine relating to the cleaning process. The subroutine is started when a cleaning instruction is issued from the user via the cleaning key 28 (FIG. 1) of the operation panel 18 (YES in step S51).
The CPU 126 controls the motor driving unit 130 to activate the motor 128 (step S52).

  Then, after waiting for the detection result of the detection sensor 110 to be turned on (YES in step S53), the motor 128 is stopped (step S54). As a result, the white roller 86 rotates once and returns to the home position (FIG. 6B). During this one rotation, as shown in FIG. 6C, the brush bristles 98 rub against the contact glass 74 to clean the surface of the contact glass 74. Further, as described above, the surface of the white reference surface 90C is cleaned when the brush bristles 103 of the white reference surface cleaning means 88 are separated from the white reference surface 90C.

  In the above example, the cleaning of the contact glass 74 and the white reference surface 90C is executed when the cleaning key 28 of the operation panel 18 is pressed (steps S52 to S54). The above-described cleaning process (steps S52 to S54) is executed when a cleaning instruction is received from an external device such as a personal computer via the network IF unit 122 (FIG. 7A). It does not matter.

Alternatively, the cleaning process (steps S52 to S54) is performed every time the cumulative number of originals conveyed by the automatic document feeder 8 through the contact glass 74 exceeds a predetermined number (for example, 10). It does not matter. This is because a known sensor is provided on the upstream side or the downstream side of the contact glass 74 on the original conveyance path, and the original passing therethrough is detected, and an internal counter (not shown) of the CPU 126 counts the number of passing sheets. This can be realized by comparing the count value with the predetermined number.
<Embodiment 2>
The image reader unit of the MFP according to the second embodiment and the subsequent embodiments is basically the same as the image reader unit of the first embodiment except that the configuration of the white roller and the white reference surface cleaning unit is different. . Therefore, hereinafter, in each embodiment, substantially the same constituent members will be denoted by the same reference numerals, will be referred to as necessary, and different portions will be mainly described.

FIG. 12 is a view of the white roller 86 and the vicinity thereof viewed from the axial direction of the shaft 92 of the white roller 86, and is drawn in the same manner as FIG.
In the first embodiment, the rotation ratio of the spur gear 108 attached to the shaft 100 to the spur gear 106 attached to the shaft 92 was 1. On the other hand, in the second embodiment, the spur gear 132 is attached to the shaft 92 of the white roller 86, and the spur gear 134 having a larger diameter and a larger number of teeth than the spur gear 132 is attached to the shaft 100 of the white reference surface cleaning means 88. The spur gear 132 and the spur gear 134 are engaged with each other. The rotation ratio of the spur gear 134 to the spur gear 132 is (1 / N) (N is a positive integer. In the illustrated example, N = 3). Therefore, with the N rotation of the white roller 86, the brush hair 103 of the white reference surface cleaning means 88 contacts the white reference surface 90C of the main body 90 of the white roller 86 once to clean the white reference surface 90C. It becomes. In other words, while the white roller 86 rotates N times, the bristle 103 is retracted outside the orbit of the bristle 98.

Thereby, the brush hair 98 is excessively compared with Embodiment 1 in which the brush hair 98 of the white reference surface cleaning means 88 contacts the white reference surface 90C and cleans the white reference surface 90C every rotation of the white roller. Can be prevented from coming into contact with the white reference surface 90C, and deterioration due to abrasion of the white reference surface 90C can be prevented.
<Embodiment 3>
FIGS. 13A and 13B are views of the white roller 86 according to the third embodiment and the vicinity thereof viewed from the axial direction of the shaft 92 of the white roller 86, and are drawn in the same manner as FIG. . FIG. 13C is a perspective view of the white reference surface cleaning unit 136.

In the first and second embodiments, in conjunction with the rotation of the white roller 86, a gear mechanism (spur gears 106, 108, spur gears) for retracting the brush hair 103 of the white reference surface cleaning means 88 from the brush hair 98 of the white roller 86 is provided. The spur gears 132 and 134) are used, but in the third embodiment, a cam mechanism is used.
The white reference surface cleaning means 88 has a shaft 138 that is rotatably supported in the housing. As shown in FIGS. 13A and 13B, the shaft 138 is joined with a holding member 140 made of a long angle member having a “L” cross section. One end of the holding member 140 in the cross section is joined to the shaft 138 over substantially the entire length thereof. Further, in the vicinity of the other end portion of the holding member 140, brush hairs 142 as a cleaning member are planted using the holding member 140 as a base material, and a brush 144 for cleaning the white reference surface 90C is configured.

The holding member 140 is provided with an extension portion where the brush hairs 142 are not implanted from the planted region of the brush hairs 142 on the back side of the paper surface in FIGS. 13A and 13B and on the right side in FIG. In addition, the hatched area in the extended portion is a cam sliding contact surface 140A on which a peripheral surface of a plate cam 146 described later comes into sliding contact.
Further, a torsion coil spring (not shown) is applied to the shaft 138 so as to apply a rotational force to the holding member 140 in the clockwise direction around the axis of the shaft 138 in FIGS. 13 (a) and 13 (b). Is attached.

  On the other hand, in FIGS. 13A and 13B, a plate cam 146 is attached to the end of the shaft 92 on the back side of the drawing. The plate cam 146 rotates integrally with the shaft 92. Further, the rotation of the plate cam 146 causes the circumferential surface thereof to contact the cam sliding contact surface 140A of the holding member 140 at an appropriate time, and the holding member 140 and thus the brush 144 are resisted against the biasing force of the torsion coil spring (not shown). And rotate counterclockwise about the shaft 138.

  FIG. 13A shows a state in which the white roller 86 is at the home position. When in the home position, the peripheral surface of the plate cam 146 is separated from the cam sliding contact surface 140A of the holding member 140, and the bristle 142 abuts against the white reference surface 90C by the biasing force of the torsion coil spring. ing. In this state, when the white roller 86 is rotated in the direction of the arrow A, the bristles 142 rub against the white reference surface 90C to clean the white reference surface 90C.

  When the rotation further proceeds, the peripheral surface of the plate cam 146 contacts the cam sliding contact surface 140A of the holding member 140, and the holding member 140 is rotated counterclockwise. At this time, when the bristles 98 of the white roller 86 pass the installation position of the bristles 142 of the white reference surface cleaning means 136 (when the bristles 98 pass through a position facing the bristles 142), the holding member The contour shape of the plate cam 146 is determined so that the counterclockwise rotation angle 140 becomes the largest and the brush bristles 142 and 98 do not contact each other.

Thereby, when the white roller 86 is rotated for cleaning the contact glass 74, the brush hair 98 of the white roller 86 is prevented from coming into contact with the brush hair 142 of the white reference surface cleaning means 136.
In the above example, when the white roller 86 is at the home position, the brush bristles 142 are brought into contact with the white reference surface 90C (FIG. 13A). In the state shown in a), the brush bristle 142 is brought into contact with the outer peripheral surface portion from the white reference surface 90C to the position where the outer peripheral surface of the main body 90 faces the contact glass 74 in the rotation direction of the main body 90. It doesn't matter. This is because the effect of preventing the dust coming from the reading position (document passage position) from adhering to the white reference surface 90C can be obtained even in this way.
<Embodiment 4>
In the first and second embodiments, a gear mechanism is used, and in the third embodiment, a cam mechanism is used, and the brush hair of the white reference surface cleaning means is moved from the brush hair 98 of the white roller 86 in conjunction with the rotation of the white roller 86. Although saved, in the fourth embodiment, other mechanisms are used.

FIG. 14A is a perspective view of the white reference surface cleaning means 148 in the fourth embodiment, and FIG. 14B is a perspective view showing one end side of the white roller 86. FIG. 15 is a view of the white roller 86 and the vicinity thereof viewed from the axial direction of the shaft 92 of the white roller 86.
The white reference surface cleaning means 148 has a shaft 150. A long holding member 152 having a substantially trapezoidal cross section across its entire length is joined to the shaft 150. In the holding member 152, brush hairs 154 that are cleaning members are planted along the longitudinal direction to form brushes 156.

  The holding member 152 has a convex piece 152A that extends in the radial direction of the shaft 150 at one end thereof. Further, a torsion coil spring (not shown) is attached to the shaft 150 so as to apply a clockwise rotational force about the axis of the shaft 150 to the holding member 152 in FIG. Further, a stopper 158 is provided for stopping the holding member 152 that is to be rotated by the rotational force at a certain angular position.

On the other hand, an arm 160 protruding in the radial direction of the shaft 92 is attached at a position corresponding to the convex piece portion 152 in the longitudinal direction of the shaft 92 of the white roller 86.
FIG. 15A shows a case where the white roller 86 is at the home position. From this state, when the white roller 86 is rotated in the clockwise direction to clean the contact glass 74 and the white reference surface 90C, the brush bristles 98 of the white roller 86 and the bristles 154 of the white reference surface cleaning means 148 Although it moves circularly to the position which opposes, since the bristle 154 exists in the retreat position which remove | deviated from the circular track | orbit of the bristle 98 as shown in FIG.15 (b), both do not contact.

  Further, when the white roller 86 is rotated, the arm 160 comes into contact with the convex piece portion 152A (FIG. 15C), pushes it up, and the holding member 152 and the brush bristles 154 are moved to the torsion coil spring (not shown). ) Against the urging force of () to rotate counterclockwise around the axis of the shaft 150. Thereby, the tip of the brush bristles 154 comes into contact with the peripheral surface of the main body 90 of the white roller 86 and becomes a bow in a slightly convex state (FIG. 15D).

  Then, when the rotation further proceeds and the arm 160 passes through the convex piece portion 152A, the holding member 152 rotates clockwise until it abuts against the stopper 158 by the biasing force of the torsion coil spring (not shown). Since the white roller 86 continues to rotate during this time, the brush bristles 154 are rubbed against the white reference surface 90C in a state where the brush bristles 154 turn slightly downward (not shown), and the white reference surface 90C is rubbed. Clean 90C.

In addition, while the white roller 86 rotates from the state shown in FIG. 15B to the state shown in FIG. 15C, the bristles 98 of the white roller 86 are contacted as shown in FIG. The contact glass 74 is cleaned by rubbing the surface of the glass 74.
<Embodiment 5>
In the first to fourth embodiments, the bristles of the white reference surface cleaning unit are retracted from the bristles of the white roller in conjunction with the rotation of the white roller 86, or the bristles of the white reference surface cleaning unit are In the fifth embodiment, the above operation is realized in conjunction with the opening / closing operation of the automatic document feeder 8 with respect to the apparatus main body.

FIG. 16 is a diagram illustrating a schematic configuration of the scanner 72 and the vicinity thereof in the fifth embodiment.
The white reference surface cleaning means 162 has a shaft 164. The shaft 164 is rotatably supported by the movable frame 82.
One end of a holding member 166 made of a long angle member having a substantially “L” cross section is joined to the shaft 164. A brush 170 for cleaning the white reference surface 90 </ b> C is configured on the other end of the holding member 166 by brushing bristles 168 serving as a cleaning member using the other end portion as a base material.

  In addition, one end of an elongated strip-shaped stick member 172 extending in the radial direction of the shaft 164 is joined to the front end of the shaft 164 of the white reference surface cleaning unit 162. One end of a tension coil spring 174 as an urging means is attached to the other end of the stick member 172. In addition, the other end side of the tension coil spring 174 is attached to the movable frame 82 (the attachment portion of the movable frame 82 is not shown). The stick member 172 imparts a clockwise rotational force to the shaft 164 by the restoring force (biasing force) of the tension coil spring 174, so the brush 170 tries to rotate clockwise about the axis of the shaft 164.

A shaft 176 is rotatably supported on the movable frame 82. One end of a rod-shaped first arm 178 extending in the radial direction is joined to the shaft 176. The other end of the first arm 178 is in contact with the stick member 172.
One end of a rod-shaped second arm 180 extending in the radial direction of the shaft 176 is joined to the opposite side via the shaft 176. The movable frame 82 is provided with a stopper 182 that restricts the rotation of the second arm 180 counterclockwise around the axis of the shaft 176.

  According to the above configuration, when the automatic document feeder 8 (FIG. 2) is closed with respect to the apparatus body, the tip of the second arm 180 contacts the platen glass 70 as shown in FIG. In contact therewith, the shaft 176 and thus the first arm 178 is rotated clockwise about the axis of the shaft 176. The second arm 180 is provided at a position that is outside the reading range of the document at the front end of the platen glass 70 in the direction perpendicular to the plane of the paper and is in contact with a position that does not hinder reading of the document.

  The stick member 172 with which the tip of the first arm 178 abuts is rotated counterclockwise about the axis of the shaft 164 by the first arm 178 against the urging force of the tension coil spring 174. Accordingly, the brush 170 also rotates counterclockwise around the axis of the shaft 164, and the brush bristles 168 are separated from the white reference surface 90C of the white roller 86 at the home position. In this state, the bristle 168 is outside the orbit of the tip of the bristle 98 of the white roller 86 and is in a retracted position from the bristle 98. Therefore, in the state shown in FIG. 16A, even if the white roller 86 is rotated clockwise for cleaning the contact glass 74, the brush hair 98 of the white roller 86 remains the brush hair 168 of the white reference surface cleaning means 162. Never touch.

  The automatic document feeder 8 shown in FIG. 16B is opened upward from the state where the automatic document feeder 8 (FIG. 2) shown in FIG. Then, the stick member 172 rotates clockwise about the axis of the shaft 164 by the biasing force of the tension coil spring 174. When pressed by the rotating stick member 172, the first arm 178 rotates counterclockwise about the axis of the shaft 176. Along with this, the second arm 180 also rotates counterclockwise, but the rotation angle is regulated by contacting the stopper 182, and thus the rotation angle of the first arm 178 is also regulated. As a result, the rotation angle of the stick member 172 pressing the first arm 178 is restricted, and as a result, the bristle 168 is positioned at a position covering the white reference surface 90C of the white roller 86 at the home position. The Rukoto.

When the automatic document feeder 8 is closed, as described above, the brush bristles 168 are separated from the white reference surface 90C. At this time, the brush bristles 168 rub against the white reference surface 90C. It will be cleaned.
<Embodiment 6>
In the fifth embodiment, in conjunction with the opening / closing operation of the automatic document feeder 8 with respect to the apparatus body, the brush hair of the white reference surface cleaning means is retracted from the brush hair of the white roller, or the brush hair of the white reference surface cleaning means is removed. In the sixth embodiment, the above operation is realized in conjunction with the opening / closing operation of the movable frame 82.

FIG. 17 is a diagram illustrating a schematic configuration of the scanner 72 and the vicinity thereof in the sixth embodiment.
The white reference surface cleaning means 184 has a shaft 186. The shaft 186 is rotatably supported by the movable frame 82.
One end of a holding member 188 made of a long angle member having a substantially “L” cross section is joined to the shaft 186. A brush 192 for cleaning the white reference surface 90 </ b> C is configured on the other end of the holding member 188 by brushing a bristle 190 as a cleaning member using the other end as a base material.

In addition, one end of a stick member 194 having an elongated strip shape extending in the radial direction of the shaft 186 is joined to the front end of the shaft 186 of the white reference surface cleaning unit 184.
A torsion coil spring 196 that applies a clockwise rotational force to the holding member 188 and the stick member 194 is attached to the shaft 186.

On the other hand, a bar member 200 is attached to the main body frame 198 of the automatic document feeder 8 (FIG. 2) to push down the stick member 194 against the urging force of the torsion coil spring 196.
According to the above configuration, when the movable frame 82 is in the closed state as shown in FIG. 17A, the tip of the bar member 200 comes into contact with the stick member 194 and pushes it down to hold the stick member 194 and the holding member. The member 188 (brush 190) is rotated counterclockwise about the axis of the shaft 186.

  Along with this, the brush 190 also rotates counterclockwise about the axis of the shaft 186, and the bristles 168 are separated from the white reference surface 90C of the white roller 86 at the home position. In this state, the bristle 190 is outside the orbit of the tip of the bristle 98 of the white roller 86 and is in a retracted position from the bristle 98. Therefore, in the state shown in FIG. 17A, even if the white roller 86 is rotated clockwise for cleaning the contact glass 74, the brush hair 98 of the white roller 86 remains the brush hair 190 of the white reference surface cleaning means 184. Never touch.

  When the movable frame 82 shown in FIG. 17 (a) is closed with respect to the main body frame 198, it is rotated counterclockwise about the shaft 84 and is opened as shown in FIG. 17 (b). The bar material 200 is separated from the stick member 194. As a result, the stick member 194 and the holding member 188 (brush 192) receive the urging force of the torsion coil spring 196 and rotate clockwise.

  A stopper 202 that restricts the clockwise rotation angle of the stick member 194 is attached to the movable frame 82. The stick member 194 comes into contact with the stopper 202 and its rotation angle is restricted, and as a result, the rotation angle of the holding member 188 (brush 192) is also restricted. Thereby, the bristle 190 will be positioned in the position which covers the white reference surface 90C of the white roller 86 in a home position.

When the movable frame 82 is closed, as described above, the brush hairs 190 are separated from the white reference surface 90C. At this time, the brush hairs 190 rub against the white reference surface 90C, so that the white reference surface 90 is cleaned. The Rukoto.
<Embodiment 7>
In Embodiments 1 to 6, the brush hair of the white reference surface cleaning means is displaced so that the brush hair of the white reference surface cleaning means and the brush hair of the white roller do not contact each other. However, in Embodiment 7, Further, by displacing the brush hair of the white roller, the brush hair of the white reference surface cleaning means and the brush hair of the white roller are not in contact with each other.

18A is a perspective view of the white roller 204, and FIG. 18B is a perspective view of the white reference surface cleaning unit 206 and the like. FIG. 19 shows a view in which the white roller 204 and the white reference surface cleaning unit 206 are arranged in parallel, as viewed from the longitudinal direction of the white roller 204.
As in the first embodiment, the white roller 204 includes a main body 90 having a flat surface 90A and a circumferential surface 90B. The main body 90 is provided with a shaft 92.

A brush 208 for cleaning the contact glass 74 is provided on the flat surface 90 </ b> A of the main body 90. The brush 208 is formed by planting brush hairs 212 as cleaning members on a base 210 made of an elongated plastic plate. The brush bristles 212 are linearly planted in the longitudinal direction of the substrate 210.
The base member 210 is attached to the flat surface 90A so as to be swingable through a hinge 214 provided along one long side.

The base member 210 has a notch 210A that is cut out with a certain width between the two ends of the other long side. Here, the protruding part of both ends of the notch 210A is referred to as a convex piece 210B.
A compression coil spring 216 is provided between each of the portions corresponding to the both convex piece portions 210B of the substrate 210 and the flat surface 90A (not shown in FIG. 18). In the state shown in FIG. 19A, the compression coil spring 216 is in a substantially free length state, and in this state, the tip of the brush bristles 212 is the circumferential surface of the main body 90 as in the first embodiment. It protrudes from the virtual circumferential surface indicated by the alternate long and short dash line extending 90B.

As shown in FIG. 18B, the white reference surface cleaning means 206 is a sponge brush 222 (hereinafter simply referred to as “brush”) in which a sponge 220 as a cleaning member is bonded to a base material 218 made of a long plastic plate. 222 ”).
The overall length of the brush 222 is shorter than the distance between the two convex piece portions 210B of the substrate 210 (the overall length of the notch portion 210A).

A pair of guide plates 224 and 226 are provided at both ends of the brush 222. Each of the guide plates 224, 226 has a shape in which approximately half of the strip-shaped plate material in the longitudinal direction is curved in an arc shape, and has flat portions 224A, 226B and curved portions 224B, 226B.
The guide plates 224 and 226 are installed such that the centers of the radii of the curved portions 224B and 226B having an arc shape coincide with the axis of the shaft 92 of the white roller 204 (FIG. 19).

In the above configuration, when the white roller 204 is at the home position, the sponge 220 of the brush 222 is in contact with the white reference surface 90C. In this state, the sponge 220 is pressed against the white reference surface 90C and is in a compressed state.
When the white roller 204 is rotated clockwise in FIG. 19A to clean the contact glass 74, first, the white reference surface 90C is rubbed against the sponge 220 to clean the white reference surface 90C.

  When the rotation further proceeds, the tip of the convex piece portion 210B of the base member 210 comes into contact with the curved portions 224B and 226B of the guide plates 224 and 226, and the base member 210 receives a pressing force from the guide plates 224 and 226. As a result, the substrate 210 swings in the direction of closing the hinge 214 against the biasing force of the compression coil spring 216, and as a result, the brush bristles 212 approach the flat surface 90A. Thereby, since the bristle 212 is withdrawn with respect to the sponge 220 approaching relatively, it can avoid that the bristle 212 and the sponge 220 contact.

  Further, when the rotation of the white roller 204 advances and the contact state with the guide plates 224 and 226 at the tip of the convex piece portion 210 </ b> B of the base material 210 is released, the base material 210 is biased (restored) by the compression coil spring 216. Force), the hinge 214 swings in the opening direction until the compression coil spring 216 becomes substantially free length. When the white roller 204 rotates in this state, the bristles 212 rub against the contact glass 74 to clean the contact glass 74.

Note that when the end of the base 210 opposite to the hinge 214 in the width direction passes through a region facing the sponge 220, the sponge 220 slides relatively through the notch 210A. The sponge 220 does not come into contact.
In the above example, when the white roller 204 is at the home position, the sponge 220 is brought into contact with the white reference surface 90C (FIG. 19A). ), The sponge 220 may be brought into contact with the outer peripheral surface portion where the outer peripheral surface of the main body 90 faces the position facing the contact glass 74 from the white reference surface 90C in the rotation direction of the main body 90. Absent. This is because the effect of preventing the dust coming from the reading position (document passage position) from adhering to the white reference surface 90C can be obtained even in this way.

As described above, the present invention has been described based on the embodiment. However, the present invention is not limited to the above-described form, and for example, the following form may be adopted.
(1) In the above embodiment, the brush hair is used as the cleaning member for the contact glass 74, but the present invention is not limited to this, and a sponge may be used. Moreover, in the said Embodiment 1-6, although the bristle was used as the cleaning member for a white reference surface, it is not restricted to this, You may use sponge. Furthermore, in the said Embodiment 7, although sponge was used as the cleaning member for a white reference surface, you may use brush hair not only in this.

Further, the cleaning member is not limited to brush hair or sponge, and other materials may be used. In short, any material that has flexibility and can be cleaned by rubbing the surface to be cleaned (contact glass surface, white reference surface) may be used.
(2) In the first to sixth embodiments, the brush hair 98 for cleaning contact glass is planted on the base material 96 and then provided on the flat surface 90A of the main body 90 of the white roller 86. Not limited to this, the brush hair may be directly planted on the flat surface 90A to constitute the brush.
(3) In the above embodiment, the white reference surface cleaning unit is provided in the second document reading unit 32. However, the white reference surface cleaning unit may be provided in the first document reading unit 30 as well.
(4) In the above-described embodiment, the image reading apparatus that reads a document image by the sheet-through method has two document reading units (first and second document reading units 30 and 32) as an example. It goes without saying that the present invention can also be applied to an image reading apparatus having only one original reading unit.
(5) In the above-described embodiment, the example in which the image reading apparatus according to the present invention is applied to a multifunction peripheral has been described. However, the present invention is not limited to this, and can also be applied to a copying machine and a facsimile apparatus.

  The image reading apparatus according to the present invention can be suitably used for, for example, a copier, a facsimile machine, and an image reader unit of a multifunction machine having these functions.

4 Image reader part 72 Scanner 74 Contact glass 86 White roller 90 Main body part 90C White reference surface 98,212 Brush hair 103,142,154,168,190 Brush hair 220 Sponge

Claims (14)

A sheet-through type image in which a document is conveyed in the sub-scanning direction, and the document image is read by a reading unit disposed through a light-transmitting member with respect to the reading position while passing the reading position defined in the main scanning direction. A reading device,
When the outer peripheral surface is divided into a first area and a second area along the rotation direction, the shading correction of the reading unit is performed in the first area when the outer peripheral surface is divided into the first area and the second area along the rotation direction. A rotating body with a reference surface for
A first cleaning member that is provided in the second region of the rotator and rubs the translucent member from the upstream side to the downstream side in the document transport direction by a circular movement caused by the rotation of the rotator. A cleaning member;
The reference surface that circulates by the rotation of the rotating body is rubbed at a second angular position that is different from the first angular position at which the reference surface faces the translucent member. A second cleaning member to be cleaned;
The first cleaning member and the second cleaning member are arranged so that the first cleaning member does not come into contact with the second cleaning member while the first cleaning member that moves around passes at least the rotation position corresponding to the second angular position. A evacuation means for evacuating one of them from the other,
An image reading apparatus comprising: When the outer peripheral surface is divided into the third region in the rotation direction in addition to the first and second regions, the third region is positioned at the home position facing the translucent member during document image reading. Is positioned,
The image reading apparatus according to claim 1, wherein when the rotating body is in the home position, the second cleaning member is in contact with the reference surface so as to cover the reference surface. The rotating body is rotated during standby when reading of an original image is not performed, and the first cleaning member cleans the translucent member,
The retracting means retracts the second cleaning member from the first cleaning member by separating the second cleaning member from the reference surface in conjunction with the rotation of the rotating body,
The image reading apparatus according to claim 2, wherein the second cleaning member cleans the reference surface by rubbing the reference surface during the separation. When the outer peripheral surface is divided into the third region in the rotation direction in addition to the first and second regions, the third region is positioned at the home position facing the translucent member during document image reading. Is positioned,
The rotating body is rotated during standby when reading of an original image is not performed, and the first cleaning member cleans the translucent member,
The retracting means moves the second cleaning member out of the orbit of the first cleaning member that moves in rotation while the rotating body rotates N times (N is a positive integer) in conjunction with the rotation of the rotating body. The image reading apparatus according to claim 1, wherein the image reading apparatus is retracted. The retracting means retracts the second cleaning member out of the orbit of the first cleaning member during reading of the document image,
2. The apparatus according to claim 1, further comprising a evacuation canceling unit configured to cancel the evacuation and bring the second cleaning member into contact with the reference surface and clean the reference surface while the document image is not read. The image reading apparatus according to 1. The rotating body is rotated during the standby, and the first cleaning member cleans the translucent member,
The image reading apparatus according to claim 5, wherein the retracting release unit has a mechanism for bringing the second cleaning member into contact with the reference surface in conjunction with the rotation of the rotating body. An image reading apparatus in which an automatic document transport unit that transports the document in the sub-scanning direction is attached to an apparatus main body having a platen glass so as to be opened and closed, and an image of a document placed on the platen glass can be read. There,
6. The image according to claim 5, wherein the evacuation is released in conjunction with an opening operation of the automatic document feeder, and the evacuation of the second cleaning member is performed in conjunction with a closing operation. Reader. The rotating body and the second cleaning member are provided on a movable frame attached to the main body frame so as to be openable and closable,
6. The image reading apparatus according to claim 5, wherein the evacuation is released in conjunction with an opening operation of the movable frame, and the evacuation of the second cleaning member is performed in conjunction with a closing operation. . The second cleaning member is fixed at a position that rubs the reference surface that is the second angular position and moves around by the rotation of the rotating body,
The retracting means prevents the first cleaning member from contacting the second cleaning member while the first cleaning member passes through the rotation position corresponding to the second angular position as the rotating body rotates. The first cleaning member is brought close to the second region, and the first cleaning member can rub the translucent member while the first cleaning member passes the first angular position. The image reading apparatus according to claim 1, wherein the image reading apparatus is separated from the two regions. When the outer peripheral surface is divided into the third region in the rotation direction in addition to the first and second regions, the third region is positioned at the home position facing the translucent member during document image reading. Is positioned,
When the rotating body is in the home position, the second cleaning member is in contact with the outer peripheral surface portion from the second angular position to the first angular position in the rotational direction of the rotating body. The image reading apparatus according to claim 1. Driving means for rotationally driving the rotating body;
Control means for controlling the drive means;
A receiving means for receiving a cleaning instruction for the translucent member from a user;
Have
11. The image reading according to claim 1, wherein when the receiving unit receives the cleaning instruction, the control unit controls the driving unit to rotate the rotating body. apparatus. Driving means for rotationally driving the rotating body;
Control means for controlling the drive means;
Accepting means for accepting a cleaning instruction of the translucent member made from an external device;
Have
11. The image reading according to claim 1, wherein when the receiving unit receives the cleaning instruction, the control unit controls the driving unit to rotate the rotating body. apparatus. Driving means for rotationally driving the rotating body;
Control means for controlling the drive means;
Counting means for counting the number of documents passing through the reading position;
Have
The image according to any one of claims 1 to 10, wherein the control means controls the driving means to rotate the rotating body every time the counting means counts a predetermined number of sheets. Reader. The first cleaning member is formed of a sponge, a brush or other flexible material;
The image reading apparatus according to claim 1, wherein the second cleaning member is made of a flexible material such as a sponge, a brush, or the like.

Images