JP2004096321A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader having a second image read means for reading a rear side of an original in an original carrying means that alleviates a shock exerted to the second image read means at opening / closing of the original carrying means, improves the opening / closing operability of the original carrying means, and permits an original to be easily placed on a read section. <P>SOLUTION: The image reader is provided with: a reader main body provided with an original platen; a first image read means provided with a line sensor for reading the original placed on the original platen; the original carrying means to carry the original onto the original platen; a turning support means for turnably supporting the original carrying means with respect to the original platen; and a second image read means provided to the original carrying means and provided with the line sensor to read an image on an opposite side of the original to the image read by the first image read means on the original carried by the original carrying means. The turning shaft of the turning support means is characteristically placed in a direction orthogonal to an arranged direction of the line sensors provided in the first and second image read means. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading apparatus such as a copying machine, a printer, a facsimile, and a scanner, and more particularly, to an image reading apparatus having an automatic document feeder for reading both sides of a document in a single document transfer process. It is about.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, some image reading apparatuses include a document transport device (document transport unit) that continuously transports a plurality of documents. In order to read images on both sides of a document, there are a type in which a document is inverted and transported twice to an image reading unit, and a type in which two image reading units are provided to read images on both sides in a single transport. An example of the latter is known, for example, as described in JP-A-2000-201251.
[0003]
That is, first image reading means provided with a line sensor for reading a document on a document table, document conveying means for conveying a document on the document table, and a document provided on the document conveying means and conveyed by the document conveying means And a second image reading means provided with a line sensor for reading an image opposite to the image read by the first image reading means.
[0004]
The shortest direction of the maximum readable document is set in the arrangement direction of the line sensor (main scanning direction), and the longitudinal direction of the maximum readable document is moved by the reading position of the line sensor or the document (sub scanning direction). Thus, the image of the document is read. This is because reading can be performed with a line sensor having a smaller number of pixels than in the case where the longitudinal direction of the largest document is set in the main scanning direction.
[0005]
Further, there is provided a rotation supporting means for rotatably supporting the document conveying means with respect to the apparatus main body. Thus, when cleaning the document table, processing a paper jam of the document being conveyed, and placing the document on the document table, the document conveying device is rotated in a direction away from the apparatus main body to thereby copy the document. After the table is opened and the respective operations are performed, the document feeder is again turned in the approaching direction, and the document feeder is in an operable state.
[0006]
Conventionally, in an image reading device including a second image reading unit in this type of document conveying device, in order to minimize the impact applied to the second image reading unit provided in the document conveying device by opening and closing the document conveying device, By making the rotation axis of the rotation support means of the document feeder parallel to the main scanning direction, the amount of movement of the second image reading means due to the rotation of the document feeder is reduced, and damage to the second image reading means, Deformation was prevented.
[0007]
[Problems to be solved by the invention]
However, even if the rotation axis of the document conveying means is parallel to the main scanning direction, the impact at the time of opening and closing the document conveying means is not necessarily applied to the second image reading means, and the user gives a strong shock to the document conveying means. When such opening / closing is performed, there is still a possibility that the reading unit may be deformed or the adjustment may be abnormal.
[0008]
Further, when the rotation axis of the document conveying means is parallel to the main scanning direction, the document is arranged in parallel with the short side direction of the largest document. Assuming that the document is operated, the longitudinal direction of the document is in the front-rear direction, and the index label is far from the user. Further, assuming that the user operates the document such that the short side of the document is in the front-rear direction, the rotation axis of the document conveying unit is right or left, and the opening and closing operation of the document conveying unit is very troublesome. turn into.
[0009]
The present invention has been made in order to solve the above-described problems of the related art, and an object of the present invention is to provide an image reading apparatus having a second image reading unit that reads the back side of a document in a document conveying unit. Provided is an image reading apparatus capable of reducing an impact applied to a second image reading unit when opening and closing a conveying unit, improving operability of opening and closing the original conveying unit, and easily placing a document on a reading unit. is there.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, a typical configuration of an image forming apparatus according to the present invention includes an apparatus main body having a document table, and a first image reading unit including a line sensor that reads a document on the document table. A document conveying means for conveying a document onto the document table, a rotation supporting means for rotatably supporting the document conveying means with respect to the document table, and a document conveying means provided on the document conveying means. A second image reading means having a line sensor for reading an image of the conveyed document opposite to the image read by the first image reading means, wherein the second image reading means comprises an elastic body. And attached to the document conveying means via
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
[First embodiment]
A first embodiment of an image reading apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is an overall cross-sectional view illustrating the configuration of the image reading apparatus according to the present embodiment, FIG. 2 is an external perspective view of the image reading apparatus, and FIG. FIG.
[0012]
The image reading apparatus shown in FIG. 1 includes a scanner section 100 as an apparatus main body having a document table, a document conveying apparatus 200 as document conveying means for conveying a document on the document table, and a scanner section 100. And a hinge portion 21 serving as a rotation support means rotatably supporting the hinge portion 21.
[0013]
The scanner unit 100 has a housing, and includes a platen glass 3 for a book original and a platen glass 2 for a sheet original on the upper surface of the housing, and a platen glass for a book original as a platen in the housing. 1 and a first reading unit 1 as a first image reading unit having a line sensor 11 for reading a document on the platen glass 2 for a sheet document.
[0014]
The book original platen glass 3 is provided with a reference white plate 901. The density data of the reference white plate 901 is read by the line sensor 11, and a pseudo value S 1 is generated based on the density data. The density of the image read by the reading unit 1 is corrected.
[0015]
The first reading unit 1 includes a first mirror base 6 to which the lamp 4 and the first mirror 5 are mounted, a second mirror base 9 to which the second and third mirrors 7 and 8 are mounted, a lens 10, And a line sensor 11 as a conversion unit. The line sensors 11 are arranged in the direction of arrow A in FIG.
[0016]
The image of the original S on the platen glass 3 for book originals or the platen glass 2 for sheet originals is illuminated by the lamp 4, and the first, second, and third mirrors 5, 7, 8 bend the optical path with the lens 10 while bending the optical path. An image is formed on the sensor 11 and read by photoelectric conversion. Since the first mirror base 6 and the second mirror base 9 are moved at a speed ratio of 2: 1 by a driving unit (not shown), the original placed on the platen glass 3 for book originals and the platen glass 2 for sheet originals is moved. The distance between the object image and the line sensor 11 is kept constant.
[0017]
The document conveying device 200 includes a contact type image sensor 20 as a second image reading unit that reads an image of the document conveyed by the document conveying device 200 on the side opposite to the image read by the first reading unit 1. .
[0018]
The conveyance system of the document conveyance device 200 includes a pickup roller 12 for taking out the documents S on the document tray 300 one by one, a separation roller pair 13 for preventing the taken-out documents from being double fed, and a document S for sheet documents. A pair of transport rollers 14, 15, 16, and 17 leading to the platen glass 2, a feed sheet guide 904 and a relay sheet guide 905, a platen roller 18 approaching the platen glass 2 for sheet document, and a platen approaching the close contact image sensor 20. The contact type image sensor 20 includes a white plate 902, a discharge roller pair 19 for transferring to the document discharge tray 400, and a discharge sheet guide 906. The contact image sensor 20 includes a transport roller pair 17 and a discharge roller pair downstream of the platen roller 18. 19 are provided.
[0019]
The contact-type image sensor 20 includes an LED (light source, not shown), a lens, and a sensor element as a line sensor serving as a photoelectric conversion unit. The image of the document S on the side opposite to the surface read by the line sensor 11 is illuminated by a lamp in the contact image sensor 20 when the document S is being conveyed by the document conveying device 200, and is illuminated on the sensor element by a lens. And is read by being photoelectrically converted.
[0020]
The density data of the platen white plate 902 is read by the contact image sensor 20, and a shading value S2 is generated based on the density data, thereby correcting the density of the image read by the contact image sensor 20.
[0021]
When reading a document conveyed by the document conveying device 200, the first and second mirror tables 6, 9 are fixed at the positions shown in FIG. When reading a book document or a document in which the document transport device 200 cannot be used, the document transport device 200 is rotated to open the platen glass 3 for book document, and then the document is placed on the platen glass 3. Reading is performed by moving and scanning the table 6 and the second mirror table 9.
[0022]
The document conveying device 200 has a function of pressing and conveying the document against the platen glass 2 for sheet document as a reading unit, and a function of covering and pressing the document on the platen glass 3 for book document. When cleaning the paper 2 and processing a paper jam at the platen roller 18, the document conveying device 200 is rotated around the hinge portion 21 so as to be separated from the sheet document platen glass 2.
[0023]
The rotation axis X of the hinge part 21 is provided so as to be orthogonal to the arrangement direction of the line sensor 11 of the first reading unit 1 and the line sensor (not shown) provided in the contact image sensor 20. .
[0024]
Here, the operability of the apparatus will be described with reference to FIG.
[0025]
First, in the open / close operability of the document feeder 200, when the user operates the scanner unit 100 at the position indicated by the arrow C (the front surface of the device), the user turns the hinge 21 of the document feeder 200 with respect to the user. Since the moving axis X is located at the back side of the apparatus (A2 direction) and the front side (A1 direction) of the document feeder 200 is lifted, the means for starting the reading operation and setting the number of sheets is also required by the user. Are arranged on the assumption that the device is operated at the position of the front surface of the device indicated by the arrow C (in the direction A1 in front of the device).
[0026]
On the other hand, when the original is placed on the book original platen glass 3, an index label 3 a as a means for positioning the original with respect to the book original platen glass 3 is arranged on the back side of the book original platen glass 3. At this time, since the user operates at the business front position indicated by arrow C, the shortest direction of the largest document is the front-rear direction (A direction) and the longitudinal direction is the left and right so that the index label 3a does not separate from the user. It is arranged in the direction (direction B).
[0027]
Next, the operation will be described.
[0028]
When the originals S are stacked on the original tray 300, the pickup roller 12 takes out and transports the uppermost original on the tray. Even if several originals are simultaneously sent out, the originals are separated and conveyed by the separation roller pair 13. Then, the sheet is conveyed toward the platen roller 18 for the sheet original by the next pair of conveying rollers 14, 15 and 16.
[0029]
Before the first document S passes the reading positions of the line sensor 11 and the contact image sensor 20, the density data of the reference white plate 901 and the platen white plate 902 are read, and shading values S1 and S2 are generated. After the line sensor 11 reads the density D1 of the platen roller 18, the first document S passes the reading position of the line sensor 11 at a predetermined speed to start reading the image information of the first surface. Is done.
[0030]
Next, after the contact type image sensor 20 reads the density E1 of the platen white plate 902, the first document S is conveyed to the conveying roller pair 17 and passes through the reading position of the contact type image sensor 20. Reading of the image information of the second surface is started. Image data read by the line sensor 11 and the contact image sensor 20 is subjected to shading correction of image density based on the shading values S1 and S2, respectively. The document S that has been read is conveyed toward the document discharge tray 400 by the discharge roller pair 19.
[0031]
After that, the density D2 of the platen roller 18 and the density E2 of the platen white plate 902 are read again, and then the first and second images of the second original S are read by the line sensor 11 and the contact image sensor 20. Since the amount of light of the lamp 4 and the lamp in the contact type image sensor 20 changes with time, the image density of the first side of the second original S is determined based on the corrected shading value S1 according to the changes in the densities D1 and D2. And performs shading correction of the image density of the second surface of the second original S based on the corrected shading value S2 according to the change in the densities E1 and E2. The same operation is repeated for the third and subsequent sheets, and the operation is stopped after the last document S has been discharged. Driving such as feeding and conveying is performed by a motor (not shown).
[0032]
In this manner, the line sensor 11 of the scanner unit 100 and the contact type image sensor 20 mounted on the document feeder 200 can read the front and back of the double-sided document S during one transfer process.
[0033]
Next, an example of mounting the contact type image sensor 20 will be described.
[0034]
As shown in FIG. 3, the close contact type image sensor 20 is fixed to the front side plate 31 and the rear side plate 32 of the document feeder 200 by screws 52a and 52b via rubber bushes 51a and 51b as elastic bodies. The front plate 31 and the rear plate 32 are integrally fixed by stays 33 to form a housing.
[0035]
In the present embodiment, the scanner unit 100 includes the reduction optical system using the line sensor 11 and the document feeder 200 includes the contact image sensor 20. However, the combination may be reversed or the scanner unit may be replaced. 100 and the document feeder 200 may be the same.
[0036]
Further, if the contact type image sensor is fixed to the platen white plate 902 instead of the front side plate 31 and the rear side plate 32, the contact type image sensor 20 can be accurately fixed to the platen white plate 902. Can be reliably approached by the close contact type image sensor 20.
[0037]
[Second embodiment]
A second embodiment of the image reading apparatus according to the present invention will be described with reference to the drawings. FIG. 4 is a detailed view of a mounting portion of the contact type image sensor according to the present embodiment. The same reference numerals are given to the same portions as those in the first embodiment, and the description is omitted.
[0038]
4A is a detailed view of a mounting portion of the contact image sensor 20, and FIG. 4B is a view of the platen white plate 902 viewed from below. In the present embodiment, the contact image sensor 20 is attached to the document feeder 200 via leaf springs 35a and 35b as elastic bodies.
[0039]
The contact type image sensor 20 is urged by the leaf springs 35a and 35b so as to abut on the white platen plate 902 via the step shafts 904a and 904b. The stepped shafts 904a and 904b are fixed to the contact image sensor 20, are fitted into the holes 902a and 902b formed in the platen white plate 902, and abut against the platen white plate 902. The plate springs 35a and 35b can be fixed to the platen white plate 902 depending on the accuracy. In order to cope with the expansion of the contact type image sensor 20 due to the heat of the built-in LED or line sensor, the contact type image sensor 20 is provided with step screws 37a in elongated holes 906a, 906b formed at one end of the leaf springs 35a, 35b. One end of the leaf springs 35a, 35b is fixed to the front plate 31 and the rear plate 32 by screws 36a, 36b, respectively.
[0040]
In the present embodiment, the contact image sensor 20 is always positioned with respect to the platen white plate 902 regardless of the bending of the leaf springs 35a and 35b. Can be approached. Needless to say, even when the elongated holes are provided in the stay 33, the close contact type image sensor 20 can be accurately fixed without depending on the bending of the leaf springs 35a and 35b.
[0041]
[Third embodiment]
A third embodiment of the image reading device according to the present invention will be described with reference to the drawings. FIG. 5 is a view for explaining the configuration of the image reading apparatus according to the present embodiment, and FIG. 6 is a detailed view of a mounting portion of the contact type image sensor according to the present embodiment. Portions are given the same reference numerals and description thereof is omitted.
[0042]
As shown in FIG. 5, in the present embodiment, the second platen roller 22 is disposed so as to face the contact type image sensor 20 provided in the document feeder 200 of the first embodiment.
[0043]
As shown in FIG. 6, the second platen roller 22 is attached to the document feeder 200 via rubber blocks 33a and 33b as elastic bodies. The front plate 31 and the rear plate 32 are integrally fixed by a stay 33 to form a housing, and the rubber blocks 33a and 33b are fixed to the front plate 31 and the rear plate 32 with an adhesive, respectively.
[0044]
The contact image sensor 20 is fixed to a holder 38. The holder 38 supports the second platen roller 22 via bearings 39a and 39b such that the second platen roller 22 can move toward and away from the close contact image sensor 20 (not shown), and is supported by compression springs 40a and 40b. The flanges 22 a and 22 b provided at both ends of the second platen roller 22 are pressed against the close contact type image sensor 20, respectively. Therefore, the gap g between the second platen roller 22 and the contact image sensor 20 is reliably ensured, so that the document S can be securely brought into close contact with the contact image sensor 20. The holder 38 is provided with an opening 38c through which the document S passes, and is fixed to the rubber blocks 33a and 33b with screws 34a and 34b.
[0045]
With the above-described configuration, even if the rubber blocks 33a and 33b are deformed, the original S can be brought close to the close contact type image sensor 20 by the second platen roller 22, so that a high-quality read image without a focus shift or the like can be obtained. can get. The hardness of the rubber blocks 33a and 33b is set so as to be deformed within a range in which the document S can be conveyed without a trouble such as a paper jam.
[0046]
Further, if the rubber blocks 33a and 33b are fixed to the relay sheet guide 905 and the discharge sheet guide 906 instead of the front side plate 31 and the rear side plate 32, the contact type image sensor 20 can be fixed to the relay sheet guide 905 and the discharge sheet guide 906. Therefore, it is possible to more reliably transfer the document S to the relay sheet guide 905 and the discharge sheet guide 906 without causing a paper jam or the like of the document S.
[0047]
[Fourth embodiment]
A fourth embodiment of the image reading apparatus according to the present invention will be described with reference to the drawings. FIG. 7 is a detailed view of a mounting portion of the close contact type image sensor according to the present embodiment. The same reference numerals are given to the same portions as those in the above embodiments, and the description is omitted.
[0048]
Also in the present embodiment, the second platen roller 22 is arranged at a position facing the close contact type image sensor 20, and leaf springs 35a, 35b are used instead of the rubber blocks 33a, 33b of the third embodiment. .
[0049]
That is, the contact image sensor 20 is attached to the document feeder 200 via the leaf springs 35a and 35b as elastic bodies. The holder 38 to which the contact type image sensor 20 is fixed abuts against the step shafts 905a and 905b fixed to the stay 33 by leaf springs 35a and 35b, and the holes 38a and 38b formed in the holder 38 are step shafts 905a and 905b. Is fitted. The holder 38 is fixed to long holes 906a, 906b formed at one ends of the plate springs 35a, 35b via step screws 37a, 37b, and one ends of the plate springs 35a, 35b are respectively fixed by screws 36a, 36b to the front plate 31, It is fixed to the rear side plate 32.
[0050]
In the present embodiment, the close contact type image sensor 20 is always positioned with respect to the stay 33 irrespective of the bending of the leaf springs 35a and 35b. It is possible to carry out the transfer between the guides 905 and the discharge sheet guide 906. Of course, even if the stepped shafts 905a and 905b are provided on the relay sheet guide 905 and the discharge sheet guide 906, the bending of the leaf springs 35a and 35b is similarly performed. Regardless, the contact image sensor 20 can be accurately fixed.
[0051]
In each of the above embodiments, the rotation axis X of the hinge 21 is provided so as to be orthogonal to the arrangement direction of the line sensors 11 of the first reading unit 1 and the line sensors provided in the contact image sensor 20. However, in the case where the contact type image sensor 20 provided in the document feeder 200 is supported by an elastic body such as rubber to absorb an impact, the rotation axis X of the hinge 21 is not necessarily set to the first reading unit 1. It may not be provided so as to be orthogonal to the arrangement direction of the line sensors provided in the line sensor 11 and the contact-type image sensor 20, and may be provided in parallel with the arrangement direction of the line sensors.
[0052]
【The invention's effect】
As described above, in the image reading apparatus according to the present invention, the rotation axis of the document conveying means having the second image reading means therein is arranged so as to be orthogonal to the arrangement direction of the line sensors for reading the image. With this configuration, the rotation axis of the document conveying means can be arranged at the back of the apparatus with respect to the user, and the shortest direction of the largest document placed on the reading unit of the apparatus can be set to the front-rear direction. In addition to improving the operability of opening and closing the means, the original can be easily placed on the reading unit.
[0053]
In addition, since the second image reading means provided on the document conveying means is supported by an elastic body such as rubber, the reading means is deformed even when the user opens and closes so as to give a strong impact to the document conveying means. In addition, stable reading image quality can be assured without causing troubles such as abnormal adjustment and the like.
[0054]
Further, by using a rubber material or a leaf spring as the elastic body, the impact on the second image reading means can be reduced with a very simple configuration.
[Brief description of the drawings]
FIG. 1 is an overall sectional view illustrating a configuration of an image reading apparatus according to a first embodiment.
FIG. 2 is an external perspective view of the image reading apparatus.
FIG. 3 is a detailed view of a mounting portion of a contact image sensor provided in the document feeder.
FIG. 4 is a detailed view of a mounting portion of the contact image sensor according to the second embodiment.
FIG. 5 is a diagram illustrating a configuration of an image reading device according to a third embodiment.
FIG. 6 is a detailed view of a mounting portion of a contact image sensor according to a third embodiment.
FIG. 7 is a detailed view of a mounting portion of a contact image sensor according to a fourth embodiment.
[Explanation of symbols]
S: Document 1: First reading unit 2: Platen glass for sheet document 3: Platen glass for book document 3a: Index label 4: Lamp 5: First mirror 6: First mirror table 7: Second mirror 8: Third Mirror 9 Second mirror base 10 Lens 11 Line sensor 12 Pickup roller 13 Separation roller pair 14 to 16 Transport roller pair 17 Transport roller pair 18 Platen roller 19 Discharge roller pair 20 Contact image sensor Reference Signs List 21 hinge part 22 second platen rollers 22a, 22b flange part 31 front side plate 32 rear side plate 33 stays 33a, 33b rubber blocks 34a, 34b screws 35a, 35b leaf springs 36a, 36b screws 37a , 37b ... Step screw 38 ... Holder 8c Opening portions 39a, 39b Bearings 40a, 40b Compression springs 51a, 51b Rubber bushings 52a, 52b Screw 100 Scanner unit 200 Document feeder 300 Document tray 400 Document discharge tray 901 Reference white plate 902 Platen white plates 902a and 902b Hole 904 Feed sheet guides 904a and 904b Step shaft 905 Relay sheet guides 905a and 905b Step shaft 906 Output sheet guides 906a and 906b Slot

Claims (4)

An apparatus body with a platen,
A first image reading unit having a line sensor for reading a document on the platen,
Document conveying means for conveying a document on the platen,
Turning support means for rotatably supporting the document conveying means with respect to the document table,
A second image reading unit provided with the line transport unit and provided with a line sensor that reads an image on the opposite side to the image read by the first image reading unit of the document transported by the document transport unit,
An image reading apparatus comprising:
An image reading apparatus, wherein the second image reading means is attached to a document conveying means via an elastic body. 2. The image reading apparatus according to claim 1, wherein a rotation axis of the rotation support means is provided in a direction orthogonal to an arrangement direction of line sensors provided in the first and second image reading means. The image reading device according to claim 1, wherein the elastic body is a rubber material. 2. The image reading device according to claim 1, wherein the elastic body is a leaf spring.

Images