JP2004045554A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader for reading both surfaces of an original, in which a read means is easily cleaned and which can easily cope with troubles such as jamming. <P>SOLUTION: Since a first platen roller 28 and a CIS 31 are attached to a cover part 17 and a scanner 19 and a second platen roller 30 are attached to a read main body part 18, the read means and a platen are separated simultaneously by the opening / closing operation of the cover part 17, so that the cleaning of the read means and the removal of the original stuck by jamming are easily performed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading apparatus capable of reading both sides of a document, which is applicable to an image forming apparatus such as a copying machine and a facsimile machine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image forming apparatus having an automatic document feeder (ADF) has a sheet fixing type in which a document is conveyed by a conveyance belt and positioned on a platen glass, and a scanner moves below the platen glass to read the document. A sheet-through type is known in which a scanner is stopped below a platen glass and a document is read while the document is conveyed on the platen glass at a constant speed.
[0003]
When scanning both sides of a document, the fixed sheet type temporarily stops the document on the platen glass.To scan both sides, it is necessary to reverse the document and then stop the document again. However, there is a drawback. In the sheet-through type, for example, Japanese Patent Application Laid-Open No. Hei 7-175279 discloses that after reading the surface of a document and transporting the document to a discharge port, the document is returned to the document feeding path from the rear end of the document and transported again. A document processor for reading the back side of a document is described. However, in this case, if the original is ejected as it is after the reading of both sides of the original is completed, the page order of the original will not be aligned, so the original is returned to the feed path again and then ejected. Needs to be conveyed three times to the original document.
[0004]
Thus, for example, as described in Japanese Patent Application Laid-Open No. 1-194658, two reading means are arranged on both sides of a conveyance path on which a document is conveyed, and the front and back surfaces of the document are moved once. Reading by transport is performed. By doing so, the number of reading means increases, but the document is conveyed only once, and the reading processing time can be shortened.
[0005]
[Problems to be solved by the invention]
A conventional image reading apparatus using two such reading means has the advantage of shortening the reading processing time, but has a portion which is set at a narrow interval between the reading means and the platen in the document transport path. Since the number of papers has increased to two places, the occurrence of jams during document conveyance naturally increases, and dirt such as paper dust generated when the document is conveyed adheres to the two reading units. Need to be performed. SUMMARY OF THE INVENTION It is an object of the present invention to provide an image reading apparatus which solves such a disadvantage of a conventional image reading apparatus.
[0006]
[Means for Solving the Problems]
An image reading apparatus according to an aspect of the present invention includes a conveying unit that conveys a document in one direction, a first reading unit that is disposed on one side of the document conveyance path and reads a surface of the document, and a conveyance path of the document. A first platen opposed to the first reading means via a second reading means arranged on the other side of the document conveyance path to read the back side of the document, and A second platen facing the second reading unit, wherein the first reading unit and the first platen are provided so as to be separated, and the second reading unit and the second platen are also provided so as to be separated. It is characterized by.
[0007]
Furthermore, the image reading device includes the cover unit and the main body unit on which the document is placed including the conveyance unit, and the first reading unit and the second platen are provided on the main body unit, The first platen and the second reading unit are provided on the cover. Further, in the closed state of the cover, an impact absorbing member is provided near the second reading means and at a contact portion between the cover and the main body. Further, the second platen provided in the main body is formed of a driving roller.
[0008]
With the above-described configuration, the space between the first reading unit and the first platen and the space between the second reading unit and the second platen can be separated. The original can be removed, and dirt such as paper dust attached to the reading means can be easily cleaned, so that both sides of the original can be read in a good condition at all times.
[0009]
In particular, when two reading units are used, it is necessary to perform cleaning of the reading unit more frequently than in the case of one unit. However, by adopting the configuration of the present invention, the cleaning operation is simplified and can be performed in a short time. It can be carried out. Furthermore, by providing the first platen and the second reading means in the cover portion and providing the first reading means and the second platen in the main body portion, the opening and closing operation of the cover portion allows the first reading means and the first platen to be in contact with each other. The second reading unit and the second platen can be separated at the same time, so that the operability of maintenance such as handling of a jam and cleaning work is remarkably improved.
[0010]
Further, as described above, by providing an impact absorbing member at a contact portion between the cover portion and the main body portion in the vicinity of the second reading means, an impact generated between the cover portion and the main body portion at the time of the closing operation is provided. It is possible to prevent the second reading means provided on the cover from being affected. Further, by using the second platen provided in the main body as a driving roller, it is possible to smoothly transport the document transported between the second reading unit and the second reading unit.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments according to the present invention will be described in detail. FIG. 1 schematically shows an entire image forming apparatus provided with an image reading apparatus according to the present invention. A document reading section 1 for transporting a document and reading both sides of the document is disposed above the image forming apparatus, and a recording section 2 for recording an image, a sheet transport section 3 for transporting a sheet for recording an image, and a paper feed section below the document reading section 1. A paper section 4 is provided.
[0012]
A plurality of sheets are stacked and set on a sheet cassette 5 in the sheet feeding unit 4, and the sheets are fed to the sheet transport unit 3 one by one. The fed sheet is conveyed to the recording unit 2 by the conveying rollers 6 and the like of the sheet conveying unit 3 to record an image, and is discharged to the sheet discharge tray 16 by the discharge rollers 15. In FIG. 1, the paper transport path is indicated by a dotted line.
[0013]
In the recording unit 2, the developer 7, the charger 9, the photosensitive drum 10, the transfer roller 11, the exposure head 12, the memory removing brush 13, and the fixing roller 14 are used for recording on the sheet conveyed by the sheet conveying unit 3. Provided. First, the surface of the photoconductor drum 10 is uniformly charged by the charger 9, and the charged photoconductor drum 10 is exposed by the exposure head 12 in accordance with an image recording signal to form an electrostatic latent image. Next, the toner in the developing device 7 is transferred to an electrostatic latent image formed on the photosensitive drum 10 by the developing roller 8 to be visualized, and the toner image formed on the surface of the photosensitive drum 10 by the transfer roller 11. Is transferred to paper. Then, the transferred toner image is heated and pressed by the fixing roller 14 to be fixed on the sheet.
[0014]
In this way, a series of processes such as charging of the photoreceptor, exposure, development, transfer and fixing to paper are performed, and an image is formed on the paper. The toner remaining on the surface of the photoconductor drum 10 after the transfer is weakened in adhesion by the memory removal brush (ERS brush) 13 and is dispersed on the surface of the photoconductor drum 10. Then, the residual toner is collected by the developing roller 8.
[0015]
The document reading section 1 includes a cover section 17 internally provided with a document transport device and a back surface reading device for reading the back side of the document, which will be described later, and a reading main body section 18 provided with a scanner 19. On the upper surface of the reading main body 18, a platen glass 20 is disposed at a portion for reading a conveyed document, and a placing bed 21 made of a transparent glass material is disposed at a portion for placing and reading a document or a book. I have. When reading a conveyed document, the scanner 19 is stopped at a position facing the platen glass 20 to perform a reading operation. When reading a document or the like placed on the placing bed 21, the scanner 19 is scanned and read. To do. A document holder 34 is attached to a surface of the cover unit 17 facing the placing bed 21, and a document tray 22 on which a plurality of documents are placed is provided above the document press 34.
[0016]
FIG. 2 is a schematic diagram illustrating the configuration of the document reading unit 1. A paper feed roller group including a feed roller 23, a retard roller 24, and a pickup roller 25, and a reading / conveying roller including a positioning roller 26, a first conveying roller 27, and a second conveying roller 29 along a document conveying path indicated by a dotted line. A group, a first platen roller 28, a second platen roller 30, and a discharge roller 32 are provided.
[0017]
At the start of reading, when the document set sensor 40 detects a document placed on the document tray 22, the pickup roller 25 of the paper feed roller group presses the document, and the feed roller 23 and the retard roller 24 rotate to move the document. Paper is fed to the transport path one by one. When the positioning sensor 41 detects the leading end of the document, the electromagnetic clutch of the positioning roller 26 is temporarily turned off, and the drive transmission is stopped. Then, after the leading edge of the document abuts against the nip portion of the positioning roller 26 and is positioned, the electromagnetic clutch is turned on and the document transport is restarted.
[0018]
Thereafter, when the document is conveyed to the first conveyance roller 27 which conveys at a constant speed and the leading edge of the document is detected by the first reading sensor 42, the surface of the document is first read by the scanner 19 at a predetermined timing. The leading edge of the document is transported to a second transport roller 29 through a space between the platen glass 20 and the first platen roller 28, and the second transport roller 29 transports the document at the same speed as the first transport roller 27. Is read while being transported at a constant speed.
[0019]
When the second reading sensor 43 detects the leading end of the document conveyed by the second carrying roller 29, a CIS (Contact Image Sensor) 31 reads the back side of the document at a predetermined timing, and the leading end of the document is directly sent to the discharge roller 32. The document is conveyed and discharged from the discharge roller 32 to the document discharge tray 33. The second platen roller 30 is provided so as to face the CIS 31, and is set so that the distance between the CIS 31 and the conveyed document does not exceed a predetermined distance.
[0020]
The feed roller 23, the positioning roller 26a, the first transport roller 27a, the second transport roller 29a, and the discharge roller 32a are drive-controlled by a controller (not shown), and the retard roller 24, the positioning roller 26b, the first transport roller 27b, The second transport roller 29b and the discharge roller 32b function as driven rollers. The rotation of the first platen roller 28 and the second platen roller 30 may be controlled in accordance with the conveyance of the original. In particular, in the case of the second platen roller 30, the reading operation can be further improved by controlling the rotation. it can.
[0021]
A roller support member 50 is provided between the platen glass 20 and the mounting bed 21 on the upper surface of the reading main body 18. As shown in FIG. 3, the roller support member 50 rotatably supports the second platen roller 30, and has extended portions 51 on both sides thereof along the longitudinal direction of the second platen roller 30. . Further, a first guide section 52, a roller groove section 53, a second guide section 54, and a third guide section 55 are arranged in this order from the upstream side in the document conveying direction. These are formed substantially parallel to the axial direction of the second platen roller 30.
[0022]
The second platen roller 30 is disposed between the second guide portion 54 and the third guide portion 55. The guide surfaces of the first guide portion 52, the second guide portion 54, and the third guide portion 55 are inclined surfaces that rise toward the downstream side in the document transport direction, and are provided along the document transport path. It is formed so as to increase as it goes from the portion 52 to the third guide portion 55.
[0023]
The roller groove 53 loads the second transport roller 29 when the cover 17 and the reading main body 18 are closed. With the second transport roller 29 loaded, the first guide section 52 acts to guide the document that has passed between the scanner 19 and the first platen roller to the second transport roller 29, and the second guide section 54 Guides the document conveyed from the second transport roller 29 between the CIS 31 and the second platen roller 30, and the third guide portion 55 transfers the document passed between the CIS 31 and the second platen roller 30 to the cover portion 17. It acts to guide the document to the document transport path.
[0024]
With the configuration as described above, the scanner 19 and the second platen roller 30 are provided in the reading main body section 18 and the first platen roller 28 and the CIS 31 are provided in the cover section 17. When the cover 17 is opened, the scanner 19 and the first platen roller 28 are separated from each other, and the CIS 31 and the second platen roller 30 are also separated from each other. In this state, the surfaces of the CIS 31 and the second platen roller 30 facing the paper are exposed, so that the surfaces can be easily cleaned and maintenance and other operations can be easily performed.
[0025]
Similarly, the opposing surfaces of the platen glass 20 and the first platen roller 28 on the front of the scanner 19 can be easily cleaned, and the maintenance work can be performed efficiently. Then, even if the document is jammed in the middle for some reason and a jam occurs, the jammed document can be easily removed by opening the cover unit 17.
[0026]
Further, since the CIS 31 is attached to the cover 17, a trouble may occur in the CIS 31 due to an impact generated by colliding with the reading main body 18 when the cover 17 is closed. Therefore, as shown in FIG. 3, the shock absorbing member 60 is attached to the extending portion 51 of the roller supporting member 50. In addition, the shock absorbing members 61 are attached to both sides of the CIS 31 in the longitudinal direction corresponding to the shock absorbing members 60.
[0027]
When the cover 17 is closed, the thickness of the shock absorbing member is adjusted so that the shock absorbing members 60 and 61 do not contact and the CIS 31 does not contact the second platen roller 30. The material of the shock absorbing member is not particularly limited as long as the material is rich in elasticity such as sponge. Further, the installation place of the shock absorbing member may be any part near the CIS 31 where the cover part 17 and the reading main body part 18 are in contact, and any place may be selected as long as the influence of the shock on the CIS 31 can be prevented. May be. Further, the shock absorbing member can be provided on either the cover unit 17 or the reading main body unit 18, and may be appropriately designed according to the degree of the shock.
[0028]
In the above embodiment, the first platen roller 28 and the CIS 31 are attached to the cover 17 and the scanner 19 and the second platen roller 30 are attached to the reading main body 18. However, the reading unit and the platen are separated. If possible, a reading means and a platen may be provided in any of them. Further, although the cover and the main body are used as a configuration for separating them, a configuration in which the components are separated inside the image reading apparatus can also be adopted. Further, although an example has been described in which a platen roller is used as a platen facing the reading unit, a pressing plate may be used as the platen.
[0029]
【The invention's effect】
As described above, since the space between the first reading unit and the first platen and the space between the second reading unit and the second platen can be separated, it is easy to remove the original even if a jam occurs in the original being transported. In addition, dirt such as paper dust adhered to the reading means can be easily cleaned, and maintenance work can be easily performed. Furthermore, by providing the first platen and the second reading means in the cover portion and providing the first reading means and the second platen in the main body portion, the opening and closing operation of the cover portion allows the first reading means and the first platen to be in contact with each other. The second reading unit and the second platen can be separated at the same time, so that the operability of maintenance such as handling of a jam and cleaning work is remarkably improved.
[0030]
Further, by providing an impact absorbing member at a contact portion between the cover and the main body in the vicinity of the reader, an impact generated between the cover and the main body when the cover is closed is provided on the cover. Can be prevented. Further, by using the second platen provided in the main body as a driving roller, it becomes possible to smoothly transport the document transported between the second reading unit and the second reading unit.
[Brief description of the drawings]
FIG. 1 is a schematic side view of an entire image forming apparatus having an embodiment according to the present invention.
FIG. 2 is a partial schematic side view of an embodiment according to the present invention.
FIG. 3 is a perspective view of the embodiment according to the present invention when a cover is opened.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 document reading section 2 recording section 3 paper transport section 4 paper feed section 5 paper feed cassette section 6 transport roller 7 developing device 8 developing roller 9 charging device 10 photosensitive drum 11 transfer roller 12 exposure head 13 memory removing brush 14 fixing roller 15 Discharge Roller 16 Paper Discharge Tray 17 Cover 18 Scanning Body 19 Scanner 20 Platen Glass 21 Placement Bed 22 Document Tray 23 Feed Roller 24 Retard Roller 25 Pickup Roller 26 Positioning Roller 27 First Transport Roller 28 First Platen Roller 29 Second Conveyance roller 30 Second platen roller 31 CIS (Contact Image Sensor)
32 Discharge Roller 33 Document Discharge Tray 34 Document Holder 40 Document Set Sensor 41 Positioning Sensor 42 First Reading Sensor 43 Second Reading Sensor 50 Roller Supporting Member 51 Extension 52 First Guide 53 Roller Groove 54 Second Guide Part 55 Third guide part 60 Shock absorbing member 61 Shock absorbing member

Claims (4)

Transport means for transporting the document in a predetermined direction; first reading means disposed on one side of the document transport path for reading one surface of the document; and first reading via the document transport path A first platen opposed to the means, a second reading means arranged on the other side of the document transport path to read the other side of the document, and the second reading means via the document transport path. An image, comprising: a second platen opposed to the first platen, wherein the first reading means and the first platen are detachably provided, and the second reading means and the second platen are also detachably provided. Reader. A cover portion on which the document is placed, the cover portion being provided with the transport device; and a main body portion supporting the cover portion so as to be openable and closable, wherein the first reading means and the second platen are provided on the main body portion. 2. The image reading apparatus according to claim 1, wherein the first platen and the second reading unit are provided on the cover. 3. The shock absorbing member according to claim 2, wherein, in the closed state of the cover, an impact absorbing member is provided near the second reading unit and at a contact portion between the cover and the main body. Image reading device. The image reading device according to claim 2, wherein the second platen provided in the main body unit includes a driving roller.

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