JP2002368960A - Image reader and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader and an image forming device which can obtain various information on a document by arranging a plurality of read sensors and perform the best image processing for read image information according to the obtained information. SOLUTION: This image reads an image of the document by arranging at least two read sensors in a conveyance path for carrying the document and is equipped with a 1st read sensor which is arranged in the conveyance path to obtain document information, a 2nd read sensor 12 which is arranged on the downstream side of the 1st read sensor to obtain image information on the document, and an image processing part 58 which performs control or image processing as to the image information obtained by the 2nd read sensor according to the document information obtained by the 1st document information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image reading apparatus and an image forming apparatus for reading image information of a document.

[0002]

2. Description of the Related Art When performing a full scan of a document (collection of document information) when reading a document with a conventional image reading apparatus, it is necessary to pass the same document a plurality of times through the same document transport path. Reading took time and reading efficiency was poor.

[0003] On the other hand, the present applicant has previously filed Japanese Patent Application No.
In Japanese Patent Application No. 01-16137, an image reading apparatus in which a plurality of reading sensors are arranged in a document conveying path and which can read efficiently is proposed. According to this image reading apparatus, since a plurality of reading sensors are arranged, it is possible to read a document image efficiently by reading one side of a plurality of documents almost simultaneously.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a plurality of reading sensors are arranged as described above, various kinds of information on a document are obtained, and image processing optimal for the read image information is performed based on this information. It is an object of the present invention to provide an image reading apparatus and an image forming apparatus which can be used.

[0005]

In order to achieve the above object, a first image reading apparatus according to the present invention has at least two reading sensors arranged on a conveying path for conveying a document and reads an image of the document. A first reading sensor arranged on the transport path to acquire document information; and a second reading sensor arranged downstream of the first reading sensor to acquire image information of the document. Means for controlling or performing image processing on the image information acquired by the second reading sensor based on the document information acquired by the first reading sensor.

According to the first image reading apparatus, original information can be acquired by the first reading sensor before the original image is read,
Optimal image processing can be performed on the read document image in real time based on the document information. The efficiency of reading an image from a document is improved.

A second image reading apparatus according to the present invention is an image reading apparatus which reads an image by arranging at least two reading sensors on a conveying path for conveying a document, and wherein the first image reading apparatus is disposed on the conveying path. A reading sensor, a second reading sensor arranged downstream of the first reading sensor to obtain image information of a document, and document information acquired by the first reading sensor. Means for performing control or image processing on the image information acquired by the second reading sensor, and pressing the document at a position facing the first reading sensor across the conveyance path and performing the first reading A document holding means installed so as to obtain shading correction data by a sensor, wherein the first reading sensor collects shading correction data and obtains document information. And changes the concentration of manuscript presser means.

According to the second image reading apparatus, it is possible to perform optimal image processing on a read document image in real time based on document information acquired before reading the document image. Efficiency is improved and shading correction data and document information can be acquired by the first reading sensor, and the density of the document pressing means can be changed between shading correction data collection and document information acquisition to be optimal in each case. Therefore, the shading correction data and the document information can be accurately obtained.

[0009] In this case, the density of the document pressing means is adjusted so that the reflected light from the document pressing means becomes uniform white in the spectral sensitivity region of the first reading sensor when the shading correction data is collected. It is preferable to change the light so that the light from the light source that irradiates the original at the time of acquiring the information is almost completely reflected light. This allows
The shading correction data can be accurately collected, and the document information can be obtained more accurately.

The document pressing means includes a roll-shaped member arranged substantially parallel to a pixel row of the first reading sensor such that a longitudinal surface is a reading surface, and the reading surface of the roll-shaped member is provided. Has a first density surface and a second density surface, and sets the reading surface of the roll-shaped member to the first density surface when the shading correction data is collected, and the second density surface when the document information is acquired. Thus, the above-described density change can be realized with a simple structure.

The first reading sensor collects shading correction data on the first density surface before the document is conveyed to the opposing position, and the document is conveyed to the opposing position to collect the shading correction data. The document information can be acquired in a state where light is reflected from the density surface of the document.

The control or image processing performed on the document information and the image information of the document obtained by each of the above image reading devices includes the following.

That is, the document information is the background of the document,
The control of the image information or the image processing is the background processing.

The document information is an average density of the document, and the control of the image information or the image processing is an EE process.

The document information is a document size or area, and the control or image processing of the image information is an automatic scaling or a document automatic arrangement process.

Further, the document information is a tilt of the document with respect to the transport direction of the transport path, and the control of the image information or the image processing is a tilt correction process.

The document information is document top and bottom information, and the control of image information or image processing is document automatic top and bottom recognition processing.

The document information is the type of a document such as a photograph or text, and the control of the image information or the image processing is filter processing.

The document information is a region of a photograph or a character type of an image in the document, and the control or image processing of the image information is a region-specific filtering process.

The document information is the presence or absence of a color image, and the control of the image information or the image processing is a color / monochrome document automatic discrimination process.

Further, an image forming apparatus according to the present invention includes the above-described image reading apparatus and an image forming apparatus main body that forms an image based on image information read by the image reading apparatus.

According to this image forming apparatus, it is possible to perform optimal image processing on the read document image in real time based on the document information acquired before the document image is read by the image reading device as described above. Since the document can be read well, efficient image formation is possible, and the productivity of image formation can be improved.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view conceptually showing an image reading apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of a roll-shaped member which is used both for document pressing and for collecting shading correction data.

As shown in FIG. 1, this image reading apparatus comprises:
A document table 20 on which a sheet-shaped document to be read is placed; a feed roller 19 for feeding the document one by one from the document table 20 into the apparatus for reading; a first conveyance roller pair 21 for conveying the document; A first reading unit 11 that reads a document image on one surface S1 (the top surface in FIG. 1) of the document S sent from the first pair of transport rollers 21 and a second device that sends the document read by the first reading unit 11 , A large-size transport path 31 and a small-size transport path 32 for guiding the document S to the lower side of the drawing by the second transport roller pair 22, and the middle of the large-size transport path 31. A pair of transport rollers 26 provided, and a third pair of transport rollers 23 that transports a document guided and transported by the large-size transport path 31 or the small-size transport path 32
And a second reading unit 12 that reads a document image on the same surface as the one surface S1 (the lower surface in FIG. 1) of the document S sent from the third transport roller pair 23 and read by the first reading unit 11.
A fourth transport roller pair 24 for transporting the original read by the second reading unit 12, a discharge transport path 36 for guiding the original to be discharged, and a discharge roller 25 for discharging the original to be discharged. And a discharge tray 30 on which the document discharged from the discharge roller 25 is placed.

In the image reading apparatus, the original sent from the second transport roller pair 22 is sent through a part of the small-size transport path 32 to be sent to reverse the original and guided.
A first reverse transport roller pair 27 and a third reverse transport roller pair 29 that can be rotated forward and reverse to transport a document in both the right and left directions in the figure; A first circulating conveyance path 3 for guiding the document sent from the reverse conveyance roller pair 27 to circulate to the first reading unit 11
And a document read by the second reading unit 12 and sent from the fourth transport roller pair 24 to the third reverse transport roller pair 2.
9, a reverse circulation path 37 for reversing the front and back of the document sent from the fourth conveyance roller pair 24 and discharging the document to the discharge tray 30; And a possible second pair of reverse conveying rollers 28.

Further, the image reading apparatus includes a second reading unit 12
And a scanning reading unit 13. Second reading unit 12
Is composed of a first platen glass 14, an optical system 16 that is stationary and fixed at a position directly below the first platen glass 14 and reads a document image, an imaging optical system 55, and a CCD image sensor 56. You. Many members of the second reading unit 12 also serve as a scanning reading unit, and the scanning reading unit 13 scans a second platen glass 15 and a document image of a document placed on the second platen glass. Optical system 1 for scanning and reading
6 ′, an imaging optical system 55, and a CCD image sensor 56.

In reading the original S by the second reading unit 12, light is emitted from a light source 51 to the original image surface of the original S being conveyed on the platen glass 14, and the reflected light is reflected by mirrors 52, 53, The reflected light is guided into the CCD image pickup device 56 via the image forming optical system 55, whereby the original image is formed on the light receiving surface of the CCD image pickup device 56 and read.

The scanning of the original S by the scanning and reading unit 13 is performed by scanning the original placed on the platen glass 15 and resting on the optical system 16 ′ along the platen glass 15 in the direction shown in FIG. While irradiating the light from the light source 51 ′, C
An original image is read by the CD image sensor 56.

In reading by the first reading unit 11,
A compact image sensor (CIS) in which a light emitting diode and a light receiving element are combined is used. In the second reading unit 12 and the scanning reading unit 13, a light source 51 composed of a halogen lamp and a CCD imaging device 56 are used in combination. The light source 51 and the CCD imaging device 56 may be a compact image sensor (CIS) in which a light emitting diode and a light receiving device similar to the first reading unit 11 are combined.

Each of the transport roller pairs 21 to 25 has a motor 65.
(FIG. 2), a transport mechanism is formed, and the speed at which the document is transported can be changed by switching the rotation speed of each transport roller pair 21 to 25 driven to rotate by the motor 65. 11 and second reading unit 1
2, the reading speed can be controlled. In order to switch the transport speed, at least the roller pairs 21 and 22 and the roller pair 2
3 and 24 are configured to be driven independently.

The image reading apparatus shown in FIG. 1 is provided with a transport direction switching mechanism in each of the transport paths 31 to 37 so as to change the transport direction of the document. That is, the second transport roller pair 22
, A conveyance direction switching member 40 that switches the sheet-like document S to be guided to the large-size conveyance path 31 or the small-size conveyance path 32, the conveyance path 35, and the conveyance path 3.
6 and a transport direction switching member 44 for switching between the transport path 36 and the reverse sheet discharge path 37, each of which is driven by a drive mechanism (not shown) and transported. It constitutes a direction switching mechanism.

As shown in FIG. 1, the first reading unit 1
A roll-shaped member 90 for pressing a document is provided at a position facing the document 1 with the conveyance path interposed therebetween, and is arranged substantially parallel to the pixel rows of the light receiving elements of the first reading unit 11.
As shown in FIG. 2, the roll-shaped member 90 includes a first density surface 91 formed on a semi-peripheral surface extending in the longitudinal direction, and a second density surface 92 similarly formed on another semi-peripheral surface. And a motor in the rotation direction R in the figure (the motor 65a in FIG. 3).
To rotate.

The first density surface 9 of the roll-shaped member 90
Numeral 1 is white for shading correction, and the second density surface 92 is a reflecting surface that reflects incident light almost completely. The first density surface 91 is white in which the reflected light of the light from the first reading unit 11 has uniform spectral characteristics in the spectral sensitivity region of the sensor of the first reading unit 11 when collecting shading correction data.

FIG. 3 is a block diagram of the flow of control signals and image data read by the image reading apparatus according to the present embodiment. Here, the solid line indicates the flow of the image data, and the broken line indicates the flow of the control signal. First
The image data relating to the document read by the reading unit 11 or the second reading unit 12 or the scanning reading unit 13 is subjected to a data conversion process, a shading correction process, a first image processing unit 57 or a second image processing unit 58. After being subjected to image processing such as compression processing and color image processing, it is stored in the memory 59.

The image data of the document read by the first reading unit 11 is mainly used for obtaining various information (document information) on the document. That is, the first reading unit 11
The background of the original, the average density of the original, the original size or original area,
First image processing is performed using document inclination with respect to the conveyance direction of the conveyance path, top and bottom information of the document, the type of the photo or text document, the area of the photo or text type of the image in the document, the presence or absence of a color image, and the like as the first image processing. The detection is performed by the unit 57. The second image processing unit 58 performs respective image processing based on each of the detected document information, and performs document processing based on the image data read by the second reading unit 12 (or the scanning reading unit 13). Read the image information.

Next, each image processing shown in FIG. 3 performed by the second image processing section 58 will be described. Each image processing can be performed by a known processing method.

In the background processing, the background is determined based on the detected background state of the document using a preset threshold value, and the background is processed so as not to be conspicuous. In the EE (Electric Eye) process, information on the document density is detected, and based on the detected information on the document density, a thin character such as a pencil stroke is determined at a preset threshold value and the density is output. And a density conversion process.

In the automatic scaling process, the original size is detected, and the original size is enlarged or reduced based on the detected original size and the set output paper size. In the automatic document arrangement processing, the original area is detected, the arrangement of the originals is determined, the layout is performed, and the processing for enlarging or reducing the original size is performed as necessary.

In the skew correction processing, the skew of the document with respect to the conveyance direction of the conveyance path is detected, and the skew of the detected document is corrected by image data processing based on the detected skew to produce an image without skew. Also, in the automatic document top and bottom recognition process, the top and bottom of the document are recognized based on the detected top and bottom information of the document.

In the filtering process, signal processing is performed by a DSP (Digital Signal Processor) or the like based on the detected type of the photo or text document so as to obtain an image suitable for the type of the document. Also, in the filtering process for each area, the DS or DS of the image in the detected original is determined according to the area of the photograph or character type.
Signal processing is performed by a P (Digital Signal Processor) or the like so that an image suitable for each area is obtained.

In the color / monochrome document automatic discrimination processing, it is determined whether the document image is a monochrome image or a color image based on the detected output level of the document image.

Each of the above-described image processing modes can be configured to be selectable by the mode selection section 67 of the operation display section 66 in FIG.

In FIG. 3, the image reading device uses the CP.
A block diagram is shown in which a control unit 64 composed of a U or the like performs control such as switching of the document transport speed, reading speed, and transport direction, switching of the roll-shaped member 90, and switching of various modes.

Before the document is conveyed to the first reading section 11, the roll-shaped member 90 is rotated by the motor 65a to rotate the first member.
Is rotated to the position where the light from the first reading unit 11 is irradiated, and then immediately before the original is conveyed to the first reading unit 11, the second density unit 92 is moved to that position. Is controlled to rotate. The reflected light from the first density unit 91 enters the first reading unit 11, and the second image processing unit 5 as described above.
In step 8, shading correction processing is performed. Further, since the second density section 92 reflects the incident light almost completely, it is possible to more reliably acquire the document information in the first reading section 11 as described above. As described above, the first density unit 91 and the second density unit 9 are controlled only by controlling the rotation of the roll-shaped member 90.
2 can be changed to a position facing the first reading section 11, so that the density can be reliably changed with a simple configuration at a good timing between the time of collecting the shading correction data and the time of obtaining the document information.

Further, based on the document information read by the first reading section 11, the monochrome image or the color image of the document image is determined as described above, and the size of the document image is determined. The document is conveyed at a high first conveyance speed for a monochrome image and at a low second conveyance speed for a color image based on the conveyance speed at the time of reading by the second reading unit. Is controlled by the control unit 64.

The control unit 64 includes a motor 65 for rotating and driving each of the conveying roller pairs 19 to 29 of FIG. 1, a motor 65a for rotating and driving the roll-shaped member 90, a single-sided-double-side mode,
An operation display section 66 including a mode selection section 67 for selecting a monochrome-color mode, a mixed mode, or each of the above-described image processing modes, and a front and rear end document detection for detecting the leading and trailing edges of a document to take reading timing Sensor K1, K2
(FIG. 1) and the transport direction switching members 40, 43, and 44 are respectively controlled.

For example, the control unit 64 in FIG. 3 controls the transport speed of the original by controlling the motor 65 for driving each pair of transport rollers, and transports the original at a higher speed than at the time of reading except during reading. As a result, the productivity of document reading can be increased. That is, from the document table to the reading unit at a high first conveyance speed, and at the time of reading, a second medium speed medium.
The control unit 64 can control the document to be conveyed at a high speed third conveyance speed to the discharge tray after reading or the next reading unit at the conveyance speed of. The first and third transport speeds, which are the high transport speeds, are preferably set to the same high transport speed in terms of simplifying control.
When, for example, the color mode is selected by the mode selection unit 67, the control unit 64 controls the motor 65 to drive each of the transport rollers at the fourth transport speed during reading so that the transport speed corresponds to the color original. Control.

In the image formation, the image data in the memory 59 is transferred to the image writing unit 6 of the image forming apparatus via the first image processing unit 57 or the second image processing unit 58.
Sent to 0. The image writing unit 60 performs writing on the photoconductor as an electrostatic latent image, develops the electrostatic latent image, and transfers and fixes the image on recording paper to form an image. Alternatively, the image data in the memory 59 may be sent to an ink-jet printer to form an image on recording paper.

When the above-described image reading apparatus is incorporated in the image forming apparatus, an image processing signal is sent to the image writing section 60 as shown in FIG. The image information is written by irradiating the photosensitive drum with the modulated laser light, the image information written on the photosensitive drum is developed, and an image is formed by transferring the image information to recording paper. The image forming apparatus will be described with reference to FIG.

FIG. 4 is a side view showing a schematic configuration of the image forming apparatus. An image forming apparatus 70 shown in FIG. 4 includes the image reading apparatus shown in FIG. 1 on an upper part thereof, and an image writing unit 60 shown in FIG. 3 to which an image signal from the CCD image pickup device 56 shown in FIG. Prepare for. Further, the image forming apparatus 70
Is a photosensitive drum 71 that is exposed to a laser beam modulated based on an image processing signal by the image writing unit 60 to form a latent image.
And a charger 72, a developing unit 73, transfer units 74 and 75, and a cleaning unit 76 disposed around the photosensitive drum 71.

In the image forming apparatus 70 shown in FIG. 4, an image is formed on the recording paper 30 as follows. The laser beam from the image writing unit 60 is exposed to the rotating photosensitive drum 71 to form a latent image, and the latent image is developed with toner by the developing unit 73. The recording paper 30 fed from the lower paper feed cassette OA or OB in FIG. 4 by a pair of conveying rollers to the upper side of the figure by the pair of conveying rollers 61 is synchronized with the rotation of the photosensitive drum 71 by the pair of conveying rollers 61 and the photosensitive drum 71 and the transfer device 74 with good timing. , 75 and the developed image is transferred to the recording paper. Next, the recording paper is transported by the transport belt 77 in the direction of the arrow in the figure, and the toner image is fixed by the fixing device 78 to form an image on the recording paper.

When the recording paper is completed with one-sided image formation, the conveyance direction switching member 81 operates to convey the conveyance roller pair 8.
5 discharges to the discharge section 80. If an image is to be formed on the opposite side of the recording paper, the conveyance direction switching member 81
Is operated, and the recording paper is sent to the lower reversing unit 83 by the pair of reversing rollers 82 and the like, is sent upward, passes through the conveying unit 84, and is conveyed in a state where it is inverted below the photosensitive drum 71,
Similarly, after the image is formed on the opposite surface, the sheet is discharged to the discharge section 80.

As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to these.
Various modifications are possible within the scope of the technical idea of the present invention. For example, the first reading unit 11 may be constituted by a CCD image sensor, and the second reading unit 12 may be constituted by a compact image sensor (CIS). Further, the second density portion of the roll-shaped member may be configured to have a chromatic color.
Further, the document information acquired by the first reading unit is not limited to the above-described one, and may be other document information. Therefore, the image processing is a process in another mode based on the other document information. Is also good.

[0054]

According to the image reading apparatus and the image forming apparatus of the present invention, a plurality of reading sensors are arranged, various kinds of document information relating to the document are acquired, and the optimum image processing for the read image information is performed based on the document information. It can be performed.

[Brief description of the drawings]

FIG. 1 is a side view showing a schematic configuration of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a roll-shaped member arranged in the image reading apparatus of FIG.

FIG. 3 is a control block diagram of the image reading apparatus of FIG. 1;

FIG. 4 is a side view illustrating a schematic configuration of an image forming apparatus including the image reading apparatus of FIG. 1;

[Explanation of symbols]

Reference Signs List 11 First reading unit (first reading sensor) 12 Second reading unit (second reading sensor) 21 to 25 Transport roller pair (transport mechanism) 31 Large-size transport path 32 Small-size transport path 33 Front and back Reverse transport path 34 First circulation front / back reverse transport path 35 Second circulation front / back reverse transport path 37 Reverse paper discharge transport path 57 First image processing unit 58 Second image processing unit (control of image information and execution of image processing) Means) 59 Memory 60 Image writing unit 70 Image forming device 90 Roll-shaped member (document pressing means) 91 First density surface 92 Second density surface S Document

Claims (14)

[Claims] 1. An image reading apparatus for arranging at least two reading sensors on a conveyance path for conveying a document and reading an image of the document, comprising: a first reading sensor arranged on the conveyance path to acquire document information; A second reading sensor arranged downstream of the first reading sensor to obtain image information of a document; and a second reading sensor based on the document information obtained by the first reading sensor. Means for performing control or image processing on the image information. 2. An image reading apparatus for reading an image by arranging at least two reading sensors on a conveyance path for conveying a document, comprising: a first reading sensor arranged on the conveyance path; and the first reading sensor. A second reading sensor that is arranged further downstream than the first reading sensor and obtains image information of the document; and the image obtained by the second reading sensor based on the document information by obtaining the document information by the first reading sensor. Means for performing control or image processing on the information; installed so as to hold a document at a position facing the first reading sensor across the conveyance path and to obtain shading correction data with the first reading sensor; A density of the document holding means when the shading correction data is collected by the first reading sensor and when the document information is acquired. Image reading apparatus according to claim and. 3. The density of the document pressing means, the reflected light from the document pressing means having uniform spectral characteristics in the spectral sensitivity region of the first reading sensor at the time of collecting the shading correction data, and 3. The image reading apparatus according to claim 2, wherein the image reading apparatus is changed so that the light from the light source that irradiates the original at the time of acquisition is almost completely reflected light. 4. The document pressing means includes a roll-shaped member arranged substantially in parallel with a pixel row of the first reading sensor such that a longitudinal surface is a reading surface, and a reading surface of the roll-shaped member is provided. Has a first density surface and a second density surface, and sets the reading surface of the roll member to the first density surface when the shading correction data is collected, and the second density surface when the document information is acquired. The image reading apparatus according to claim 2, wherein the image reading apparatus rotates the image reading apparatus. 5. The first reading sensor collects shading correction data on the first density surface before the document is conveyed to the opposing position, and then conveys the document to the opposing position to collect the shading correction data. The image reading apparatus according to claim 4, wherein the document information is acquired in a state where light is reflected from the density surface of No. 2. 6. The image reading apparatus according to claim 1, wherein the document information is a background of the document, and the control of the image information or the image processing is a background process. 7. The document information is an average density of the document.
6. The image reading apparatus according to claim 1, wherein the control of the image information or the image processing is EE processing. 8. The apparatus according to claim 1, wherein the document information is a document size or area, and the control or image processing of the image information is automatic scaling or document automatic arrangement processing. An image reading device according to the item. 9. The method according to claim 1, wherein the document information is a tilt of the document with respect to a transport direction of the transport path, and the control of the image information or the image processing is a tilt correction process.
The image reading device according to any one of claims 1 to 5. 10. The apparatus according to claim 1, wherein the document information is top and bottom information of the document, and the control of the image information or the image processing is an automatic document top and bottom recognition process. Image reading device. 11. The apparatus according to claim 1, wherein the document information is a type of a document such as a photograph or text, and the control of the image information or the image processing is a filtering process. Image reading device. 12. The apparatus according to claim 1, wherein the document information is a region of a photograph or a character type of an image in the document, and the control of the image information or the image processing is a filtering process for each region. 2. The image reading device according to claim 1. 13. The document information indicating whether a color image exists,
The image reading apparatus according to claim 1, wherein the control of the image information or the image processing is a color / monochrome original automatic discrimination processing. 14. An image forming apparatus comprising: the image reading apparatus according to claim 1; and an image forming apparatus main body that forms an image based on image information read by the image reading apparatus. Image forming apparatus.