JP2010004415A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent foreign matters removed from a reading glass by a cleaning member from soaring upward as the cleaning member rotates, in an image reader structured so that the foreign matters on the surface of a reading glass are removed by the cleaning member. <P>SOLUTION: A plate member 6 is provided so as to make contact with a brush part 32 on the downstream side in the rotating direction of the cleaning member 3 more than a region where a first platen glass G1 is brought into the brush part 32. In order to more effectively prevent foreign matters from scattering to the upper part of the first platen glass G1, a gap between the body part 31 of the cleaning member 3 and the cleaning member side of the plate member 6 is preferably not more than 5 mm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus, and more particularly to an image reading apparatus provided with a cleaning member.

  As an image reading apparatus that optically reads image information of a document, a platen set method that reads image information of a document placed on a platen glass, a document is conveyed one by one, and the image information of a document is The sheet-through method for reading has been used individually or in combination. The sheet-through method has advantages in downsizing, low cost, low noise, high-speed image reading, and high print productivity, and has become the mainstream of image reading devices in monochrome copiers. The introduction is also desired.

  In the case of the sheet-through method, a document image is read on the image surface of the document passing through the other side of the reading glass by an image reading unit fixed on one side of the transparent member (long reading glass). In order to read with the focus of the optical system, if a foreign substance such as dust adheres to the reading glass, a portion shielded by the foreign substance becomes streak image noise in the read image.

  Foreign materials that adhere to the reading glass include paper dust that scatters from paper-based documents, floating foreign materials such as dust in the atmosphere, and adhesive tape or glue that has adhered to the document. There are sticky foreign matters such as ink balls of ballpoint pens and eraser scraps.

Therefore, for example, Patent Document 1 proposes a technique in which an elastic member is attached to the outer periphery of a white roller provided above the reading glass, and the surface of the reading glass is rubbed and cleaned with the elastic member.
JP2000-270152

  However, the proposed technique does not take into consideration that the foreign matter removed from the reading glass by the cleaning member flies upward along with the rotation of the cleaning member and then reattaches to the reading glass surface.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to remove the foreign matter on the surface of the reading glass from the reading glass by the cleaning member in the image reading apparatus that removes the foreign matter on the surface of the reading glass by the cleaning member. This is to prevent foreign matters from moving upward with the rotation of the cleaning member.

  According to the present invention, a plate-like transparent member through which a document passes through one side, a reading unit that optically reads image information of a document that passes through the other side of the transparent member, and a rotatable main body And a cleaning member having elasticity and extending in the axial direction of the main body, and the cleaning member provided so that the cleaning portion contacts the surface of the transparent member on the document passage side, and the cleaning A plate-like member provided so as to come into contact with the cleaning unit on the downstream side in the rotation direction of the cleaning member with respect to the region in which the part comes into contact with the transparent member, and the surface of the transparent member by rotation of the cleaning member The image reading apparatus is characterized in that the plate-like member prevents the scattering of foreign matter above the transparent member.

  Here, in order to more effectively prevent the scattering of foreign matter above the transparent member, the clearance between the main body of the cleaning member and the end of the plate-like member on the cleaning member side is set to 5 mm or less. preferable.

  Further, in order to effectively and efficiently remove the foreign matter adhering to the transparent member, it is preferable to use a plurality of hairs as the cleaning part, and the hairs are conductive fibers. Is preferred.

  The cleaning by the cleaning member may be performed every time the document passes.

  Further, the prevention or restoration of the deformation of the cleaning member by rotating the cleaning member in the reverse direction may be performed every time when the number of documents passing through the transparent member reaches a predetermined number, or the document passing through the transparent member. It may be performed every time the accumulated length of reaches a predetermined length.

  In addition, according to the present invention, in an image forming apparatus that reads an original image and forms an image on a transferred member, the image reading apparatus according to any one of the above and the image information read by the image reading apparatus. An image forming apparatus including an image forming unit that forms an image based on the image forming apparatus is provided.

  In the image reading apparatus of the present invention, the plate-like member provided on the downstream side in the rotation direction of the cleaning member with respect to the region where the cleaning unit comes into contact with the transparent member prevents foreign matter from rising upward as the cleaning member rotates. The foreign matter removed by the cleaning member is prevented from reattaching to the reading glass surface.

  Hereinafter, the image reading apparatus according to the present invention will be described in more detail, but the present invention is not limited to these embodiments.

  FIG. 1 is a schematic diagram showing an embodiment of an image reading apparatus according to the present invention. The image reading apparatus shown in FIG. 1 reads an original conveyed by an automatic original conveying apparatus (hereinafter sometimes referred to as “ADF”) 2 by an image reading unit (reading means) 10. The documents placed on the document placement tray 21 are pulled out from the document placement tray 21 by the pickup roller 24, and sent one by one to the conveyance path by the feed roller 25 and the separation roller 26. And it is conveyed by the conveyance roller pair 27 on the 1st platen glass (transparent member) G1. When the document passes over the surface of the first platen glass G1, the image information of the document is read by the image reading unit 10 provided below G1 of the first platen glass. The document that has passed through the first platen glass G1 is discharged onto the discharge tray 22 by the conveyance roller pair 28 and the discharge roller pair 29. A cleaning member 3 is rotatably provided above the first platen glass G1.

  On the other hand, the image reading unit 10 includes a scanning unit 16 including a light source 161 and a mirror 162, a traveling body 17 including roof mirrors 171 and 172 for guiding reflected light, an imaging lens 18, and a CCD sensor 19. Reading of the image information of the original by the image reading unit 10 is performed by irradiating the original with the light source 161 of the scanning unit 16 when the original passes over the first platen glass G1 and using the reflected light of the two pieces of the traveling body 17. The image is guided onto the CCD sensor 19 through the roof mirrors 171 and 172 and the imaging lens 18 to form an image. The CCD sensor 19 converts the read light image into electronic image data and sends it to an image processing unit (not shown). The image processing unit performs analog processing, A / D conversion, shading correction, image compression processing, and the like on the electronic image data, and then sends the digitized image information data to the image forming unit 11 (shown in FIG. 5). . When the original is placed on the second platen glass G2, which is another image reading surface, and the image information of the original is read, the scanning unit 16 and the traveling body 17 are arranged along the second platen glass G2. , And the reflected light is guided to the CCD sensor 19 for image formation and read.

  FIG. 2 shows an enlarged view of the vicinity of the first platen glass G1, and FIG. 3 shows a perspective view showing an example of the cleaning member 3 and the plate-like member 6, respectively. As shown in FIG. 2, the cleaning member 3 is rotatably provided on a frame (not shown) by a shaft portion 33 above the separation on the document passage surface side of the first platen glass G1. The cleaning member 3 includes a main body portion 31 formed of a columnar body having a circular cross-sectional outline perpendicular to the axial direction, and a brush portion (cleaning device) in which a plurality of hair bodies 321 are attached to a planar portion of the main body portion 31. Part) 32. The hair-like body 321 is preferably composed of conductive fibers. This is because the brush portion 32 prevents frictional charging when the first platen glass G1 is rubbed. Moreover, you may use the outer peripheral surface in which the brush part 32 of the main-body part 31 is not formed in white, and can use it as a white reference surface for white level correction | amendment.

  A step sheet 20 is adhered to the upstream side of the first platen glass G1 in the document conveyance direction. The document M conveyed by the step sheet 20 passes through the image reading position in a non-contact state with the first platen glass G1. Since the original M does not come into contact with the first platen glass G1, adhesive foreign matters such as adhesive portions of the tape adhered to the original M and peeling of adhesive, correction fluid, ink pens of ball-point pens, eraser scraps, and the like are removed. Adhesion to the glass G1 is suppressed. In order to prevent the original M from coming into contact with the image reading position of the first platen glass G1, in addition to using the step sheet 20, the original M does not come into contact with the first platen glass G1 which is generated by making the original M curved. For example, an image reading position may be provided in the area. Of course, the image may be read by bringing the document M into contact with the first platen glass G1.

  As shown in FIG. 2, a light source 161 and roof mirrors 162 and 171 as part of the image reading means are provided on the surface of the first platen glass G1 opposite to the original passage surface. When the document M is transported onto the first platen glass G1 by the transport roller pair 27 and the guide plate, light is emitted from a light source 161 such as a rare gas fluorescent lamp, and the light reflected on the document M is reflected on the platen glass. Reflected by the roof mirrors 162 and 171 immediately below G1, guided to the CCD sensor 19 (described in FIG. 1) and imaged as described above, and image information is read.

  While the document M is passing over the first platen glass G1, the cleaning member 3 is stopped so that the portion of the main body 31 where the brush portion 32 is not formed is on the document transport side (FIG. 2). (A) and FIG. 3 (a)). As a result, the main body 31 of the cleaning member 3 also serves as a guide for the document M being conveyed. Alternatively, the cleaning member 3 may be rotated at a speed much slower than the document conveyance speed so that the portion of the main body 31 where the brush portion 32 is not formed is always on the document conveyance side. When the document M passes over the first platen glass G1, the cleaning member 3 rotates in the same direction as the document conveyance direction on the first platen glass G1 (counterclockwise in FIG. 2) (FIG. 2B). And FIG. 3 (b)). As a result, the brush portion 32 of the cleaning member 3 rubs against the first platen glass G1, and foreign matters attached to the surface of the first platen glass G1 are removed.

  Further, in the vicinity of the cleaning member 3 on the downstream side in the rotation direction from the first platen glass G1, a plate-like member elongated in the axial direction of the cleaning member 3 so as to contact the brush portion 32 and not to contact the main body portion 31. 6 is attached. As shown in FIG. 4, a part of the rotation region of the cleaning member 3 is blocked by the plate-like member 6, and the foreign matter removed from the first platen glass G <b> 1 scatters upward with the rotation of the cleaning member 3. Is suppressed, and foreign matter is prevented from dropping and adhering again onto the first platen glass G1. Further, the rotating brush part 32 comes into contact with the plate-like member 6, so that the foreign matter attached to the brush part 32 is scraped off and the foreign matter is prevented from accumulating in the brush part 32. In addition, when the original M is being conveyed (FIG. 2A), the original M is conveyed while being guided by the plate-like member 6.

  In order to make the plate-like member 6 more effective in preventing the upward scattering of foreign matter and the effect of scraping off the foreign matter attached to the brush portion 32, as shown in FIG. The gap d between the end portion and the main body 31 of the cleaning member 3 is preferably 5 mm or less. More preferably, it is 3 mm or less.

  Although the material of the plate-like member 6 is not particularly limited, a conductive material is desirable from the viewpoint of preventing frictional charging with the cleaning unit 32, and for example, a metal material such as stainless steel can be suitably used.

  When a plurality of documents M are continuously conveyed, the cleaning of the first platen glass G1 by the cleaning member 3 is performed every time the document M passes through the first platen glass G1. Alternatively, it is performed after all the series of documents M have passed. From the viewpoint of reliably preventing foreign matter from adhering to the first platen glass G1, cleaning by the former is desirable. In addition, when a document reading start signal is input, it is desirable to clean the first platen glass G1 by rotating the cleaning member 3 forward before the document is conveyed.

  The cleaning part is not particularly limited as long as it has elasticity. For example, a sponge member or a rubber blade can be used in addition to the brush part made of a hair.

  Next, the image forming apparatus according to the present invention will be described. FIG. 5 is a schematic diagram of an image forming apparatus including the image reading apparatus shown in FIG. The image forming apparatus in this figure is a so-called in-body discharge type image forming apparatus. A paper discharge space 4 having an open front side is formed at a substantially central portion in the vertical direction of the apparatus main body. On the bottom surface of the paper discharge space 4, a tray 87 for placing discharged paper is integrally formed with the casing. On the other hand, an image reading unit 10 for reading a document is built in the upper side of the paper discharge space 4, and an image forming unit 11 is built in the lower side of the paper discharge space 4.

  The image forming unit 11 will be described. The surface of the photosensitive drum 50 is uniformly charged positively or negatively by a charging device 51. As described above, the image data read by the image reading device is written on the surface of the photosensitive drum 50 by the laser scanner (exposure device) 52, and an electrostatic latent image is formed on the surface of the photosensitive drum 50. The Specifically, in the case of the reverse development method, the charge corresponding to the image is removed, and in the case of the regular development method, the charge corresponding to the background is removed to form an electrostatic latent image. Next, the developing device 53 visualizes the electrostatic latent image on the photosensitive drum 50 with toner. At this time, the charging polarity of the toner is the same as the charging polarity of the photosensitive drum 50 in the case of the reversal development method, and is opposite to the charging polarity of the photosensitive drum 50 in the case of regular development.

  On the other hand, the paper P stored in the paper feed cassette 80 is pulled out by the pickup roller 81, and is sandwiched between the paper feed roller 82 and the separating roller 83 and sent to the transport path one by one. Then, the registration roller pair 84 feeds the paper P to the transfer unit at the timing when the toner image on the photosensitive drum 50 reaches the transfer unit. In the transfer portion, the sheet P is sandwiched between the photosensitive drum 50 and the transfer roller 54, and a charge having a polarity opposite to the toner charging polarity is applied to the transfer roller 54. Toner image moves onto the paper P. The toner remaining on the photosensitive drum 50 without moving onto the paper P is removed and collected by the cleaning roller 55. On the other hand, the paper P on which the toner image is placed is conveyed to the fixing roller pair 85. Here, the toner image is heated and pressurized by the fixing roller pair 85 and fixed on the paper P. Then, the paper P is sent to the discharge roller pair 86 and discharged to the tray 87. Note that the paper P placed on the manual feed tray 88 is fed to the registration roller pair 84 by the paper feed roller 89, and thereafter passes through the same path as the above-described transport path.

  In the image reading apparatus of the present invention, the foreign material removed by the cleaning member rises upward with the rotation of the cleaning member by the plate-like member provided on the downstream side in the rotation direction of the cleaning member with respect to the region where the cleaning unit contacts the transparent member. , It is prevented from reattaching to the reading glass surface. As a result, image noise caused by foreign matter adhering to the reading glass is prevented.

1 is a schematic diagram illustrating an example of an image reading apparatus according to the present invention. FIG. 2 is an enlarged view of the vicinity of a first platen glass of the image reading apparatus in FIG. 1. FIG. 2 is a perspective view of the vicinity of a first platen glass of the image reading apparatus of FIG. It is a figure explaining each operation | movement of the penetration | invasion prevention of the foreign material to the 1st platen glass G1 upper direction by the plate-shaped member, and scraping off of the foreign material from a brush part. 1 is a schematic diagram illustrating an example of an image forming apparatus according to the present invention.

Explanation of symbols

2 ADF (automatic document feeder)
DESCRIPTION OF SYMBOLS 3 Cleaning member 6 Plate-shaped member 10 Image reading part 11 Image formation means 31 Main-body part 32 Brush part (cleaning part)
G1 1st platen glass (transparent member)
G2 Second platen glass 321 Ciliary body

Claims (6)

A plate-like transparent member through which the document passes on one side;
Reading means for optically reading image information of a document passing therethrough from the other surface side of the transparent member;
Cleaning having a rotatable main body portion and an elastic cleaning portion extending in the axial direction of the main body portion so that the cleaning portion contacts the surface of the transparent member on the document passage side. Members,
A plate-like member provided so as to come into contact with the cleaning unit on the downstream side in the rotation direction of the cleaning member from a region where the cleaning unit comes into contact with the transparent member;
An image reading apparatus that cleans the surface of the transparent member by rotation of the cleaning member and prevents scattering of foreign matter above the transparent member by the plate member.   The image reading apparatus according to claim 1, wherein a gap between the main body of the cleaning member and an end of the plate-like member on the cleaning member side is 5 mm or less.   The image reading apparatus according to claim 1, wherein the cleaning unit includes a plurality of hairs.   The image reading apparatus according to claim 3, wherein the hair is made of a conductive fiber.   The image reading apparatus according to claim 1, wherein the transparent member is cleaned by rotating the cleaning member each time a document passes.   An image forming apparatus that reads an original image and forms an image on a transfer member, and forms an image based on the image reading apparatus according to claim 1 and image information read by the image reading apparatus. An image forming apparatus comprising: