JP2004357070A - Document reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem of small smoothness of carrying a document and a hindrance of high-speed reading of double-sided document because of a cross position in a switch back path or in a carrying path, and a problem of out-of-order of a reading optical system caused by shock during the process of plugging of the document in a double-sided document reader. <P>SOLUTION: There is no cross position in a structure of a carrying path, and though the both-sided images of the document are read by respectively different readers and both sides of the document are read at high speed in the constitution, a document carrying unit and the reader are differently constituted. Then, the document carrying path has no cross structure or no switch-back structure, so the high-speed reading of the document can be carried out smoothly, and the out-of-order of the optical system caused by shock applied to the reading optical system can be prevented during the process of plugging of the document. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading apparatus, and more particularly, to a document reading apparatus capable of reading both sides of a document conveyed by document conveying means at a high speed.
[0002]
2. Description of the Related Art A reading device is arranged oppositely through contact glasses of the same size which are arranged opposite to each other with an original conveying path interposed therebetween, and the original is conveyed between the contact glasses so that both sides of the original are read almost simultaneously. A double-sided image reading device has been proposed (see Patent Document 1). Also, after reading the first side of the original image by the image reading unit, the original is reversed in a loop shape and the second side of the original image is read. A double-sided image reading apparatus that reads both sides of a document at high speed has been proposed (see Patent Document 2).
[0003]
[Patent Document 1]
Japanese Patent No. 3224252 [Patent Document 2]
JP, 2002-29666, A
[Problems to be solved by the invention]
In the apparatus described in Patent Document 1, when a document is jammed between the contact glasses facing each other, the reading device having one contact glass is moved to the side having the other contact glass in order to open the transport path. I have to lift it. Then, it is necessary to return the side having the contact glass lifted after processing the jammed document to the original position. There is a possibility that the adjustment of the reading optical system on the side that performs the opening / closing operation may be out of order due to the impact accompanying the opening / closing at the time of processing such a document jam.
In the apparatus described in Patent Document 2, there is only one document reading section, and the platen roller must be reversed every time a document is fed and discharged. Therefore, the speed of high-speed reading is limited. Since the platen roller repeats reversal during double-sided reading, the service life of the mechanical components that drive the platen roller may be shortened.
[0005]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a document reading apparatus that can solve the above-described problem in a conventional document reading apparatus capable of reading a document having images on both sides as described above.
[0006]
[Means for Solving the Problems]
According to the present invention, in a document reading device capable of reading a document having image information on both sides, a document conveyance device having an S-shaped document conveyance path that is substantially laid down, A first reading unit for reading the first document surface and a second reading unit for reading a second document surface different from the first surface are arranged on substantially the same plane. In this manner, since the image forming apparatus is configured so as not to have a portion that crosses the document transport path or a portion that switches back, the reading of both sides of the document is performed smoothly and at a higher speed than in the related art. It becomes possible. In addition, since the reading device faces the same side of the document transport device, even if a document jam occurs, the transport path of the document transport device can be opened and processed, and the reading devices are provided on both sides of the document transport route. As compared with the case where the reading operation is performed, there is no possibility that the reading apparatus receives an impact due to the paper jam processing.
[0007]
In the present invention, the cross-sectional shape of one of the two reading devices is substantially rectangular, and the cross-sectional shape of the other reading device is substantially L-shaped. Since it is possible to increase the length of the reading device corresponding to the above, it is possible to increase the resolution when reading the original.
[0008]
In the present invention, the two reading devices are arranged side by side in the horizontal direction. With such a configuration, there is an advantage that the same component can be used because the configuration of the reading apparatus is targeted.
[0009]
In the present invention, of the first reading device and the second reading device, one optical system is configured by a moving optical system, and the other optical system is configured by a fixed optical system. A bound document such as thick paper or a book that cannot be transported by the document transport device can also be read.
[0010]
According to the present invention, in a double-sided image reading apparatus for reading an original having image information on both sides, when reading both sides of the original continuously, the original is conveyed before the second side of the preceding original is read by the second reading apparatus. Since it is possible to start the conveyance of the subsequent document by using the means, it is possible to increase the speed even when reading the document continuously.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, unless otherwise specified. It is only an example.
[0012]
FIG. 1 is a conceptual diagram of a two-sided document reading device according to a first embodiment of the present invention, and FIG. 2 is a conceptual diagram of a two-sided document reading device according to a second embodiment of the present invention.
In the figure, the same components are denoted by the same reference numerals. In FIG. 1, reference numeral 1 denotes a document feeder provided above a copying machine main body (not shown). Roller 5, sheet feeding roller 6, reversing sheet feeding roller 7, registration roller pair 8, first platen roller 9, auxiliary conveyance roller 10, plural sets of document conveyance roller pairs 11, A two-platen roller 12, an auxiliary transport roller 13, a discharge roller pair 14, and a document discharge tray 15 are arranged. A contact glass is disposed on the upper surface of the copying machine main body, and two image reading apparatuses, that is, a first reading apparatus 3 and a second reading apparatus 4 are disposed below the contact glass. In the present invention, since the reading optical system is intended to read a double-sided document at a high speed of 100 sheets or more per minute, a fixed optical system is employed.
[0013]
First, referring to FIG. 1, in the embodiment of the present invention, a plurality of documents stacked on a document feed tray (not shown) with the first side (front side) facing down are instructed to start a copying operation. Then, among the stacked originals, the original is transported from the bottom original to the inside of the original transport device 1 in FIG. Here, the original is fed to the position of the paper feed roller 6 by the feed pickup roller 5, and the paper feed roller 6 separates the originals one by one in cooperation with the paper feed reversing roller 7 to register the original. -Conveyed to pair 8; The original conveyed to the pair of registration rollers 8 is temporarily stopped in a state of contact with the pair of registration rollers 8, and if the original is skewed, the inclination of the original is adjusted. After the timing is adjusted, the sheet is conveyed to the first platen roller 9. The second side (back side) of the document which has reached the first reading nip 16 between the first platen roller 9 and the contact glass 20 disposed on the upper surface of the copying machine while being inverted by the first platen roller 9 The image of () is read as follows. The document transported to the first platen roller 9 is transported by the auxiliary transport roller 10 in close contact with the first platen roller 9.
[0014]
Light for reading emitted from a lamp 31 which is a light source of the first reading device 3 is radiated toward a document by a reflector 32, and light reflected from a second surface of the document is reflected by a plurality of reflection mirrors 33. The light is guided to the lens system 34, and the magnification and the focus are adjusted by the lens system 34, and then an image is formed on the CCD 35 which is a solid-state image sensor. The image formed and read on the CCD 35 is digitally converted and read into the memory of the apparatus.
[0015]
The document for which the reading of the second side (back side) has been completed is once conveyed to the upper right by a plurality of document convey roller pairs 11 and then conveyed horizontally, and further conveyed to the lower right by the second platen roller. -Reach la 12; The first side (front side) of the document which has been inverted by the second platen roller 12 and has reached the second reading nip portion 17 between the second platen roller 12 and the contact glass 20 disposed on the upper surface of the copying machine main body. The image is read as described below. The document transported to the second platen roller 12 is transported by the auxiliary transport roller 13 in close contact with the second platen roller 12. Further, a pair of registration rollers for the second platen roller may be provided on the document conveyance path on the upstream side of the second platen roller 12 to correct the skew of the document or to adjust the reading timing. .
[0016]
Next, reading of the image on the first surface of the document that has reached the second reading nip will be described. Light for reading emitted from a lamp 41 as a light source is radiated toward a document by a reflector 42, and reflected light from the document is guided to a lens system 44 via a reflection mirror 43, and the magnification is magnified by the lens system 44. After the focus is adjusted, an image is formed on the CCD 45 which is a solid-state imaging device. The image formed and read on the CCD 45 is digitally converted and read into the memory of the apparatus.
[0017]
The original on which the reading of the first surface (front surface) has been completed is conveyed obliquely to the upper left by the discharge roller pair 14 with the first surface facing down, and discharged to the document discharge tray 15. The document discharge tray 15 is a portion above a cavity provided in an intermediate portion of the document reading device 1, and the document whose reading has been completed can be taken out by pulling out the document discharge tray 15 from the document reading device 1. .
[0018]
In the present invention, as shown in FIG. 1, the document transport path is formed in an S-shape in which the document transport path is substantially laid, so that the length of the document transport device 1 in the document transport direction can be shortened. Since it is possible to read each side of the document at two reading positions facing the lower surface and arranged side by side on the same plane, a reading device is provided on both sides of the document conveying path as in the conventional example. Compared with the case of arrangement, there is no possibility that the adjustment of the optical system of the reading apparatus is disrupted by the impact due to the document jam processing. Further, in the present invention, since there is no configuration that intersects the document transport path or that switches back, the control of document transport is easy, and the speed of document transport is easy.
[0019]
Also, as shown in FIG. 1, the image reading device is configured such that the first reading device 3 having a substantially rectangular cross section is placed on the second reading device 4 having a substantially L-shaped cross section. A compact configuration can be achieved while sufficiently securing the optical path length of the reading unit. Further, as described later, when the optical system of the first reading device 3 having a substantially rectangular cross section is a moving optical system, the length of the first reading device 3 in the longitudinal direction is made as large as possible. A large-sized document such as A3 size can be configured to be readable.
[0020]
In the present invention, the reading optical system is a fixed optical system, but the optical system of the first reading device 3 in FIG. 1 is a movable reading optical system, and the contact glass 30 of the first reading device 3 is With the same size as the upper surface, it is possible to read a thick paper document such as a postcard or a bound document such as a book that cannot be transported by the document transport device 1.
[0021]
When a large number of copies are to be made, before reading the first side of the preceding document, that is, when reading of one side of the document (the second side in the present invention) is completed, the next document is read. It is possible to start conveyance, and furthermore, only by providing a minimum space required by design between the preceding document and the following document, the reading of the following document during reading of the second side of the preceding document is possible. It is also possible to start transport. This means that the speed can be considerably increased as compared with the current mainstream switchback method of reading both sides of a document. The reason is that, in the method of reading both sides of a document by switching back the document, the conveyance of the following document cannot be started until the preceding document has been separated from the switchback path by reading both sides of the document.
[0022]
FIG. 2 shows a second embodiment of the present invention, in which the configuration of the document feeder 1 is the same as that of the first embodiment, but the configuration of the image reading device provided in the main body of the copying machine is the first. Different from the embodiment. In the configuration of FIG. 2, the first reading device 3 and the second reading device 4 having substantially the same cross-sectional shape are arranged side by side in the horizontal direction. Therefore, one of the reading devices is designed after designing one of the reading devices. May be designed by reversing the configuration of the previously designed reader, which has the advantage of cost, such as the common use of members, and repairs or repairs if any of the readers fail. Easy to replace. Since the read image on the second surface of the document is read in reverse, it is necessary to perform mirror image reversal in image processing.
Also, in the configuration of FIG. 2, if a moving optical system is used instead of a fixed optical system for either the first reading device 3 or the second reading device 4, an original such as thick paper that is not suitable for the original conveyance can be read. it can. It is also possible to read a bound original such as a book.
[0023]
The copier to which the present invention is applied can read a one-sided original, and is configured to convey the original using the original conveying device 1 of the present invention and read the original surface by the second reading device.
[0024]
【The invention's effect】
According to the invention of the present application, since there is no crossing configuration or switchback configuration in the document transport path, high-speed reading of the document can be performed smoothly, and furthermore, the optical system is disordered due to the impact on the reading optical system even when the document is jammed. Can be prevented.
Further, if the image reading apparatus is configured as in the present invention, it is possible to make the copying machine compact, which is advantageous in terms of cost, and maintenance and repair can be easily performed.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a duplex image reading apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a double-sided image reading apparatus according to a second embodiment of the present invention.
[Explanation of symbols]
8 Registration Roller Pair 9 First Platen Roller 11 Conveyance Roller 12 Second Platen Roller 14 Discharge Roller Pair 15 Document Discharge Tray

Claims (5)

A document reading apparatus capable of reading a document having image information on both sides thereof, wherein the document conveying path has an S-shaped document conveying path that is substantially laid, and a first document surface along the conveying path of the document conveying apparatus. A document reading apparatus, wherein a first reading unit for reading a document and a second reading unit for reading a second document surface different from the first surface are arranged on substantially the same plane. 2. The cross-sectional shape of one of the first and second reading devices is substantially rectangular, and the cross-sectional shape of the other reading device is substantially L-shaped. 3. Document reading device according to the above. 2. The document reading device according to claim 1, wherein the first reading device or the second reading device is arranged in a horizontal direction. 4. The optical system according to claim 2, wherein one of the first reading device and the second reading device is configured by a movable optical system, and the other optical system is configured by a fixed optical system. Original reading device. In a double-sided image reading apparatus for reading a document having image information on both sides, when reading both sides of a document continuously, use the document conveying means before reading the second side of the preceding document with the second reading apparatus. 2. The document reading apparatus according to claim 1, wherein conveyance of a subsequent document is started.

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