JP3833623B2 - Image reader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image reading apparatus that reads an image of a document being automatically conveyed.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been known an image reading apparatus that automatically conveys a document from a predetermined document tray to a conveyance path by an ADF (automatic document feeder (automatic sheet feeding unit)) and reads an image of the document being conveyed. Further, for example, as disclosed in Japanese Patent Application Laid-Open No. H10-260260, there is known a configuration in which image reading means is arranged on each side of a document being conveyed so that images on both sides of the document can be read in parallel. As a result, it is possible to read images from both sides of the original (single-sided reading of the original image) with one transport of the original.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-69087
[0004]
[Problems to be solved by the invention]
However, depending on the user, it is often the case that both-side reading of the original image is used, and in such a case, the operating rate of one of the image reading means (the image reading means for the back side) is low and the efficiency is low There was a problem.
On the other hand, if the image on one side of the document being conveyed can be read by each of the plurality of image reading means, for example, dust adhered to the image reading means by mutual complementation of the image data read by the plurality of image reading means. By removing (preventing) vertical streaks that occur in the image data due to the above, or by adjusting the reading density of each of the plurality of image reading means when you want to adjust the reading density of the image on a trial and error basis, It is possible to improve image quality and convenience, such as reducing the number of trials by obtaining image data with a plurality of density settings in one document transport.
Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to enable both-side reading of a document image and image reading in an image reading apparatus that reads an image of a document being automatically conveyed. An object of the present invention is to provide an image reading apparatus capable of improving the image quality and convenience by effectively utilizing the means.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an image reading apparatus that automatically conveys a document from a predetermined document tray and reads an image of the document being conveyed. A first image reading means for reading an image on one side, and a movement so as to selectively read an image on the one side or the other side of the document being conveyed on the first conveyance path; And a second image reading unit configured to be capable of being configured as an image reading device.
With this configuration, both sides of the original can be read by moving the second image reading means, and the image on the one side can be read twice using two image reading means simultaneously. it can. As a result, it is possible to improve image quality by mutually complementing the two obtained image data.
[0006]
If the image reading conditions in the first and second image reading means can be set individually, the reading conditions can be changed on a trial and error basis by changing the reading conditions of the two image reading means. It is possible to reduce the number of trials when it is desired to adjust the value.
[0007]
And a second conveyance path which is a conveyance path for the original document different from the first conveyance path, and the second image reading unit is configured to transmit one of the original documents being conveyed on the second conveyance path. A configuration is also possible in which the image of the surface is movable so that it can be read selectively. Thus, for example, if two conveyance paths are used alternately, the operating rates of the two image reading means are dispersed, leading to a longer life of the entire image reading means.
[0008]
And a document branching unit that switches between the first and second transport paths for guiding the document transported from the document tray, and each of the first and second transport paths by the document branching unit. It is also conceivable that the originals are sequentially guided to read the original image in parallel by the first and second image reading means in the first and second transport paths, respectively.
As a result, the operating rates of the two image reading means are distributed, leading to a longer life of the entire image reading means, and it is possible to speed up the reading of a plurality of documents.
[0009]
It is also conceivable that a cleaning means for cleaning the second image reading means and a shading plate used for shading correction of the second image reading means are arranged on the moving path of the second image reading means. .
Accordingly, it is possible to perform cleaning and shading correction of the second image reading unit by utilizing the fact that the second image reading unit is movable.
[0010]
Further, a configuration in which the second image reading means can be moved to a position where it can be taken out from the image reading apparatus is also conceivable.
As a result, the second image reading means can be easily taken out and maintained.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments and examples of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. It should be noted that the following embodiments and examples are examples embodying the present invention, and do not limit the technical scope of the present invention.
FIG. 1 is a diagram schematically showing a schematic cross section of the image reading apparatus X according to the embodiment of the present invention. FIG. 2 is a document supply means provided in the image reading apparatus X according to the embodiment of the present invention. FIG. 3 schematically shows a schematic section of the document branching means provided in the image reading apparatus X according to the embodiment of the present invention, and FIG. 4 shows an embodiment of the present invention. It is the figure which represented typically the schematic cross section of the 2nd image reading means with which the image reading apparatus X which concerns on the form, and its moving mechanism are equipped.
[0012]
First, the configuration of the image reading apparatus X according to the embodiment of the present invention will be described with reference to FIG.
A document tray 1 for loading the document S, a document supply means 2 for discharging the document S from the document tray 1 (supplying it into the apparatus), and a first transport path of two documents S provided in parallel. The first and second transport paths R1 (an example of the transport path) and the second transport path R2 (an example of the sub-transport path) and the document S that is transported from the document tray 1 by the document supply unit 2 are transferred. Document branching means 3 for switching to one of the transport paths R1 and R2, a plurality of transport rollers 4 for transporting the document S in the first and second transport paths R1 and R2, and the first transport path First image reading that reads an image of one surface of the document S that is transporting R1 (the upper surface side when it is placed on the document tray 1, hereinafter referred to as a front surface for convenience) through the glass plate 7. Means 8 and the original S being conveyed through the first conveyance path R1. A movable surface so that an image of the front surface and the opposite surface (the other surface) (hereinafter referred to as the back surface) and the front surface of the document S being conveyed through the second conveyance path R2 can be selectively read. The second image reading means 9, the document discharge tray 5 from which the document S on which the image has been read is discharged, and the document table 6 that functions as a platen glass when reading the document image one by one manually. It has.
[0013]
The first image reading means 8 includes first and second scanning units 81 and 82 which are two optical system scanning units.
The first scanning unit 81 exposes line by line in the main scanning direction (depth direction in FIG. 1) while stopping at a predetermined transported document reading position P0, and reflects reflected light from the document S to the second scanning unit 81. A light source (for example, an exposure lamp such as a halogen lamp or a fluorescent lamp) 81 a and a first reflection mirror 81 b that guides reflected light from the document S to the second scanning unit 82 are provided to guide the scanning unit 82. .
The second scanning unit 82 is controlled so as to follow the first scanning unit 81 and move at a predetermined speed (for example, half the speed of the first scanning unit 81), and the first reflection unit 82 Second and third reflection mirrors 82a and 82b for guiding the reflected light from the mirror 81b to the imaging lens 83 are provided. The imaging lens 83 forms an image of the reflected light from the third reflection mirror 82b on a CCD 84 (Charge Coupled Device). The CCD 84 converts the reflected light from the imaging lens 83 into an analog electric signal. The electrical signal is converted into digital image data by an image processing unit (not shown) and stored in an image memory or output to an image forming apparatus or an external device.
The configuration of the second image reading unit 9 will be described later. Further, the arrangement position of the first and second image reading means 9 is not limited to the position shown in FIG. 1, but it is desirable that they are not arranged opposite to each other in view of the quality of the read image.
[0014]
The image reading apparatus X is configured to be able to select four modes of a high image quality reading mode, a two-condition reading mode, a high-speed reading mode, and a double-sided reading mode by a setting operation from an operation unit (not shown).
In the high-quality reading mode, the image on the front surface of the document S being conveyed on the first conveying path R1 is read by the same reading condition (reading) by both the first and second image reading means 8 and 9. (Hereinafter, reading the image of the same side of the document with the two image reading means 8 and 9 is called twice), and the obtained two image data are not shown. In a mode in which image correction processing is performed such as removing (preventing) vertical streaks generated in image data due to dust or the like adhering to the first or second image reading means by complementing each other by an image processing unit. is there.
The two-condition reading mode is the same as the high-quality reading mode in that the two-time reading is performed, but the reading conditions are individually set in advance for each of the first and second image reading means 8 and 9 in advance. (Reading density conditions, etc.) can be set, and two image data under each condition can be obtained. As a result, when it is desired to adjust the image reading conditions (density, etc.) on a trial and error basis, it is possible to obtain image data with two condition settings by carrying the document once, so the number of trials can be reduced. Become.
In the high-speed reading mode, the document branching means 3 sequentially guides the document S to the first and second transport paths R1 and R2, respectively. In this mode, the images on the front surface of the document S are read in parallel by the first and second image reading means 8 and 9. As a result, two images of one side of the document S are read almost simultaneously (in parallel) two at a time, so that it is possible to read a plurality of documents S (single side reading) at high speed.
In the double-sided reading mode, the front surface of the document S being conveyed on the first conveying path R1 is read by the first image reading means 8, and the back surface is read by the second image reading means. 9 for reading. As a result, it is possible to obtain image data on both sides of the original S once.
[0015]
Next, the configuration and operation of the document supply means 2 will be described with reference to FIGS. 2A to 2D schematically show a schematic cross section of the document supply means 2. FIG.
As shown in FIG. 2A, the document supply unit 2 includes an air feeding belt 22 that is an endless belt that rotates around two rotating rollers 21. The air feeding belt 22 is disposed so as to be close to the uppermost surface of the document S placed on the feeding tray 1, and a plurality of holes (not shown) are provided over substantially the entire surface of the belt. Air is sucked (air sucked) from the lower side (original S side) to the upper side through the hole.
Hereinafter, the operation of supplying the document S by the document supply means 2 when the high-speed reading mode is set will be described with reference to FIGS.
First, when a document supply command is received from a control unit (not shown), the air feeding belt 22 rotates in the supply direction of the document S, and air suction through the hole of the air feeding belt 22 is started (see FIG. 2 (a) state). As a result, the uppermost document S1 is sucked by the air feeding belt 22, and the sucked document S is applied to a primary feeding roller 23 (roller pair) provided at a subsequent stage according to the rotation of the air feeding belt 22. It is conveyed toward (state of FIG. 2 (b)). Here, from the downstream side of the document S in the conveyance direction (left direction in FIG. 2) and from the lower side of the document S sucked by the air feeding belt 22, the document S is directed upstream and obliquely upward. Air is jetted from the slit-like nozzle 24. As a result, even if the second and subsequent documents are likely to adhere to the uppermost document S1 due to static electricity or the like, the second and subsequent documents S are caused by the action of the air jet from the nozzle 24. Is peeled off from the uppermost document S1, so that the document S can be prevented from being double fed.
[0016]
After the transport of the uppermost document S1 has been taken over by the primary sheet feed roller 23, the rear end (the most downstream end in the transport direction) side of the document S1 is the document S side of the air feed belt 22. Therefore, the second original S2 from the uppermost surface is identical to the uppermost original S by the suction action through the hole of the air feeding belt 22 in the released state. The air is fed to the air feeding belt 22 in a state of overlapping (the state shown in FIG. 2C).
The second original S2 sucked in this way is also conveyed toward the primary paper supply roller 23 according to the rotation of the air paper supply belt 22, and after the conveyance has been taken over by the primary paper supply roller 23. The rotation of the air feeding belt 22 and the air suction through the hole of the belt 22 are stopped (state shown in FIG. 2D). As a result, the top and second originals S1 and S2 are then conveyed by the rotational force of the primary paper feed roller. The timing of stopping the rotation of the air feeding belt 22 and the air suction is detected by, for example, a pressure change (pressure increase) on the suction side of the air suction or according to a document size set from an operation unit (not shown). It may be determined by measuring the elapsed time. By sequentially repeating the operations shown in FIGS. 2A to 2D, two originals S1 and S2 are sequentially carried out from the original tray 1 in a partially overlapping state (sequentially supplied into the apparatus). )
Of course, the original S may be supplied (carry out) one by one without overlapping with a conventional general pickup roller or the like, but in the case of supplying the original with the configuration and operation shown in FIG. The time required for document supply is shortened compared to the conventional method of waiting for complete unloading one sheet at a time. In particular, when the document size is large or the number of documents is large, the effect of shortening the time appears significantly.
As described above, the uppermost and second originals S1 and S2 sequentially carried out in a partially overlapping state are guided to the transport paths R1 and R2 by the original branching unit 3, respectively. The images of the documents S1 and S2 are read in the first and second transport paths R1 and R2 in parallel. The operation of the document branching means 3 in this case will be described later.
On the other hand, when a mode other than the high-speed reading mode is set, the rotation of the air feeding belt 22 and the air suction are stopped in the state shown in FIG. By repeating this operation, the uppermost document S1 is supplied one by one.
[0017]
Next, the configuration and operation of the document branching means 3 will be described with reference to FIGS. 3 (a) and 3 (b). FIGS. 3A and 3B are views schematically showing a schematic cross section of the document branching means 3.
As shown in FIG. 3A, the document branching means 3 includes first and second secondary paper feed rollers 33 provided at the respective entrances of the first and second transport paths R1 and R2. 34 (a pair of rollers), which is provided so as to be able to swing, and to which of the first and second secondary paper feed rollers 33 and 34 the document S conveyed from the primary paper feed roller 23 is guided. The movable guide plate 31 to be switched, and the original S guided by the movable guide plate 31 are more reliably supplied to the first and second secondary paper feed rollers 33 and 34 (that is, the first and second secondary feed rollers 33 and 34). And a brush roller 32 guided to one of the transport paths R1, R2).
When the high-speed reading mode is set, when the uppermost and second originals S1 and S2 are conveyed in a partially overlapping state as described above (in synchronization with the operation of the original supply means 2). First, as shown in FIG. 3A, the movable guide plate 31 swings toward the first conveyance path R1, and the brush roller 32 conveys the document S1 to the first conveyance path. By rotating in the direction leading to the path R1 (counterclockwise in FIG. 3), the uppermost document S1 is guided to the first transport path R1 (the first secondary paper feed roller 33). .
Next, for example, after a predetermined time required for the original S1 to reach the first secondary paper feed roller 33 (or the front end of the original S1 is detected by the predetermined secondary paper feed sensor 33 by the first secondary paper feed roller 33). And the like, the movable guide plate 31 swings toward the second conveyance path R2 and the brush roller 32 is subsequently conveyed. By reversing S2 in the direction leading to the second transport path R2 (clockwise in FIG. 3), the second document S2 is placed on the second transport path R2 side (the second secondary paper feed). To the roller 34 side). As a result, the documents are sequentially guided to the first and second transport paths R1 and R2, respectively, and the images of the two documents S1 and S2 are read in the first and second transport paths R1 and R2 in parallel. Will be.
On the other hand, when a mode other than the high-speed reading mode is set, the document S conveyed one by one is always operated in the state shown in FIG. 3A, so that the first conveyance path R1. Guided to the side.
[0018]
Next, the configuration and operation of the second image reading means 9 will be described with reference to FIG. FIG. 4 schematically shows a schematic cross section of the second image reading means and the moving mechanism thereof, and a second image reading unit 90 having the second image reading means is shown in a broken line frame. Only the part is taken out and represented.
As shown in FIG. 4, the second image reading means 9 is made from a contact image sensor (CIS) in which a contact glass 94 and a light source 91 formed in an array, an imaging lens 92, and a CCD 93 are integrated. Thus, the second image reading unit 90 is configured together with the two guide plates 9a and 9b which are guide means for the document S. It is also conceivable that the guide means for the document S is constituted by other means such as a guide roller.
The second image reading means 9 can be rotated around a predetermined rotation axis 95 by a drive source such as a stepping motor (not shown) in the second image reading unit 90, and the guide plate 9a. , 9b and the white shading plate 11 (reference reading density setting plate) and the contact glass 94 used for the shading correction in the second image reading means 9 and the contact glass 94 are cleaned. It is configured to be able to stop in a direction V3 toward the cleaning device 12 (cleaning means).
Thereby, the image of the document S passing (conveyed) between the guide plate 9a and the contact glass 94 is read in a state where the second image reading means 9 is stopped in the V1 direction. The image of the document S passing (conveyed) between the guide plate 9b and the contact glass 94 can be read in a state where the image is stopped in the V2 direction.
[0019]
The second image reading unit 90 is supported by a guide rail 10 disposed in a direction substantially orthogonal to the first and second transport paths R1 and R2, and includes a stepping motor or the like (not shown). It is configured to be movable along the guide rail 10 by a driving source. Then, the second image reading unit 90 is located at a position where the first conveyance path R1 and the second guide plate 9b and the gap between the contact glasses 94 in the V2 direction (document passage) coincide. A double reading position P3, which is a position where the reading position P2, the first conveying path R1, the first guide plate 9a, and the gap between the contact glass 94 in the V1 direction (original passage) coincide with each other. , A shading correction position P4 that is a position facing the shading plate 11, a cleaning position P5 that is a position facing the cleaning device 12, and the second transport path R2, the second guide plate 9b, and the contact glass. It is configured to be able to stop at each position of the parallel reading position P6 that is a position where 94 gaps (original passages) coincide (ie, the shade). Ring plate 11 and the cleaning device 12 is arranged in the movement path of the second image reading unit 9). In the image reading apparatus X, a stepping motor is used to move the second image reading unit 90, and the second image reading unit 90 is positioned at each of the positions P2 to P6 according to a moving distance (number of steps) from a predetermined reference position P1. At the reference position P1 near one end of the guide rail 10, a unit detection sensor 13 for detecting whether or not the second image reading means 9 exists at that position is provided. 13, the reference position P1 is positioned.
The reference position P1 is a position at which the second image reading unit 90 can be taken out from the image reading device X without disassembling the device X. As a result, the second image reading means 9 can be easily taken out and maintained.
[0020]
When the high image quality reading mode or the two-condition reading mode is set, the second image reading unit 90 is positioned at the second reading position P2 and the second image reading mode. Means 9 are oriented in the V2 direction. As a result, it is possible to read the image of the front surface of the document S being conveyed on the first conveyance path R1, and the image of the document S being conveyed on the first conveyance path R1 is the first image. The second image reading means 8 and 9 perform the reading twice, thereby complementing the two obtained image data to improve image quality, and adjusting the image reading conditions on a trial and error basis. When it is desired, the number of trials can be reduced.
When the high-speed reading mode is set, the second image reading unit 90 is positioned at the parallel reading position P6 and the second image reading means 9 is directed in the V2 direction. As a result, it becomes possible to read the image on the front surface of the document S being conveyed on the second conveyance path R2, and the first and second conveyance paths R1 and R2 respectively. The image reading means 8 and 9 read the image on the front surface of the document S in parallel, so that high-speed image reading is possible. Further, since the operating rate is distributed to the first and second image reading devices 8 and 9, respectively, the life of the first and second image reading means 8 and 9 as a whole is extended. Of course, even if such parallel reading is not performed, for example, the document S can be transported alternately to the first and second transport paths R1 and R2 one by one. The life of the image reading means 8 and 9 as a whole is extended.
When the double-sided reading mode is set, the second image reading unit 90 is positioned at the double-sided reading position P3, and the second image reading means 9 is directed in the V1 direction. As a result, it is possible to read an image on the back side of the document S being conveyed through the first conveyance path R1, and the first and second image reading means 8 and 9 can be used to read the first conveyance path R1. Images on both the front and back sides of the document S being conveyed can be read in parallel.
When the shading correction of the second image reading means 9 is performed at the time of start-up or when a predetermined operation is performed, the second image reading unit 90 is positioned at the shading correction position P4. At the same time, the second image reading means 9 is directed in the V3 direction. Similarly, when cleaning the contact glass 94, the second image reading unit 90 is positioned at the cleaning position P5 and the second image reading means 9 is directed in the V3 direction.
Accordingly, it is possible to perform cleaning and shading correction of the second image reading unit 9 by utilizing the fact that the second image reading unit 9 is movable.
[0021]
【The invention's effect】
As described above, according to the present invention, it is possible to read the image on the front side by moving the image reading means (second image reading means) for the back side of the document that is generally less frequently used. Thus, it is possible to read the image on the front side twice by using the two image reading means at the same time while allowing the both sides of the original to be read. As a result, the image quality is improved by performing mutual complementation of the two obtained image data, etc., and trials for adjusting the reading conditions by trial and error by changing the reading conditions of each of the plurality of image reading means The number of times can be reduced.
Further, a new document transport path is provided, and the image reading means for the back side can be moved to the newly provided transport path, and the document is sequentially guided to each of the two transport paths, and the image of the document in each of the two transport paths. Can be read in parallel, the reading speed of a plurality of documents can be increased, and the operating rate is distributed, leading to a longer life of the entire image reading means.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a schematic cross section of an image reading apparatus X according to an embodiment of the present invention.
FIG. 2 is a diagram schematically showing a schematic cross section of a document supply unit included in the image reading apparatus X according to the embodiment of the present invention.
FIG. 3 is a diagram schematically showing a schematic cross section of a document branching unit included in the image reading apparatus X according to the embodiment of the present invention.
FIG. 4 is a diagram schematically showing a schematic cross section of a second image reading unit and a moving mechanism thereof included in the image reading apparatus X according to the embodiment of the present invention.
[Explanation of symbols]
1 ... Document tray
2 ... Document supply means
3. Document branching means
4 ... Conveying roller
5 ... Document output tray
6 ... Document table
7 ... Glass plate
8: First image reading means
9. Second image reading means
10 ... Guide rail
11 ... Shading board
12 ... Cleaning device
13 ... Unit detection sensor
21 ... Rotating roller
22 ... Air feeding belt
23 ... Primary paper feed roller
24 ... Nozzle
31 ... Movable guide plate
32 ... Brush roller
33. First secondary paper feed roller
34. Second secondary paper feed roller
90 ... Second image reading unit
91 ... Light source
92 ... Imaging lens 92
93 ... CCD
94 ... contact glass
9a, 9b ... guide plate
R1 ... 1st conveyance path
R2 ... Second transport path
S, S1, S2 ... Original

Claims (7)

In an image reading apparatus that automatically conveys a document from a predetermined document tray and reads an image of the document being conveyed,
First image reading means for reading an image on one side of the document being conveyed on a predetermined first conveyance path;
A second image reading means configured to be movable so as to selectively read an image on either one side or the other side of the document being conveyed on the first conveyance path;
An image reading apparatus comprising: The image reading apparatus according to claim 1, wherein the image reading conditions in the first and second image reading units can be individually set. A second transport path which is a transport path for the original document different from the first transport path;
3. The apparatus according to claim 1, wherein the second image reading unit is configured to be movable so as to selectively read an image on one side of the document being conveyed on the second conveyance path. The image reading apparatus described. Comprising a document branching means for switching whether the document transported from the document tray is guided to the first transport path or the second transport path;
By sequentially guiding the originals to the first and second transport paths by the original branching unit, the images of the originals by the first and second image reading units in the first and second transport paths, respectively. The image reading apparatus according to claim 3, wherein the image reading apparatus is configured to be capable of reading in parallel. 5. The image reading apparatus according to claim 1, further comprising a cleaning unit that is disposed in a moving path of the second image reading unit and cleans the second image reading unit. The image reading apparatus according to claim 1, further comprising a shading plate that is disposed in a moving path of the second image reading unit and is used for shading correction of the second image reading unit. The image reading apparatus according to claim 1, wherein the second image reading unit is configured to be movable to a position where the second image reading unit can be taken out from the image reading apparatus.

Images