JP2011217050A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make backside transcription of an original document and reading black of a surrounding of the original document at least selectively suppressible without providing a plurality of movable members and variable color panels in an image reading device provided with a first image-reading unit for reading an image of one surface of the original document to be conveyed along a conveyance path and a second image-reading unit for reading an image of the other surface of the original document to be conveyed along the conveyance path.SOLUTION: When a second reading device 230 moves to a first position where a lens 232 and a light-receiving element 233 of the second reading device 230 are opposed to a white reference plate 217 of a first reading device 210, a white reference plate 237 of the second reading device 230 is opposed to a lens 212 and a light-receiving element 213 of a first reading device 210 (A). When the second reading device 230 moves to a second position where the lens 232 and the light-receiving element 233 are opposed to a black reference plate 218, the black reference plate 238 is opposed to the lens 212 and the light-receiving element 213 (B).

Description

  The present invention relates to an image reading apparatus that reads an image of a document, and more specifically, a first image reading unit that reads an image on one side of a document that is transported along a transport path, and is transported along the transport path. The present invention relates to an image reading apparatus including a second image reading unit that reads an image on the other side of the document.

  2. Description of the Related Art Conventionally, an image reading device that reads an image of a document is applied to devices such as a scanner, a copying machine, and a facsimile machine. As a configuration for reading images on both sides of a document with this type of image reading apparatus, a configuration has been proposed in which a single image reading unit reads images on both the front and back sides by reversing the document by devising the conveyance path of the document. In recent years, however, a configuration has been proposed in which two image reading units simultaneously read both front and back images.

  Further, in such an apparatus that reads an image while conveying an original, it has been proposed to suppress show-through as follows as an apparatus that reads only one side of an original through the first image reading unit. Yes. That is, when a movable member having a white surface portion and a black surface portion or a variable color panel is arranged on the back surface of an original whose image is read by the first image reading section, and the original is thin paper and it is desired to suppress show-through, For example, a black surface portion is arranged on the back surface to suppress show-through. Further, in this apparatus, when the document is an irregular size, it is possible to prevent the periphery of the document from being read in black by arranging a white surface portion on the back surface of the document (see, for example, Patent Document 1). ).

JP 2001-2108018 A

  However, when the technique described in Patent Document 1 is applied to an image reading apparatus including two image reading units as described above, it is necessary to individually provide a movable member or a variable color panel for each image reading unit. The manufacturing cost of the device increases. Accordingly, the present invention provides a first image reading unit that reads an image on one side of a document that is conveyed along a conveyance path, and a first image reading unit that reads an image on the other side of the document that is conveyed along the conveyance path. In an image reading apparatus including a two-image reading unit, it is possible to at least selectively suppress the show-through of a document and reading of the periphery of the document in black without providing a plurality of movable members and variable color panels. As made.

The image reading apparatus of the present invention, which has been made to achieve the above object, has at least a first position and a second position along the transport path on one side opposed to each other across the transport path of the document. A first image reading unit that is movably provided and reads an image on one side of the document conveyed along the conveyance path; A second image reading unit that reads an image on the other side of the document conveyed along a conveyance path; and a second image reading unit that is provided on the other side of the document along the conveyance path. A white first white plate facing the first image reading unit and the other side position along the transport path, and the first image reading unit is moved to the first position. When moved to position 2, facing the first image reading unit The first colored plate colored with a color other than white and the first image reading unit are moved along the transport path, and the first image reading unit is disposed at the first position. The white second white plate facing the second image reading unit and the first image reading unit move along the conveyance path, and the first image reading unit is moved to the second position. And a second colored plate that is colored with a color other than white when opposed to the second image reading unit.

  In the image reading apparatus of the present invention configured as described above, the first image reading unit provided so as to be movable at least between the first position and the second position along the document conveyance path includes the above-described conveyance. An image on one side of the document conveyed along the path is read. The second image reading unit, which is immovably provided on the other side facing the first image reading unit across the conveyance path, is provided on the other side of the document conveyed along the conveyance path. Read the image. Therefore, the image reading apparatus of the present invention can simultaneously read images on both the front and back sides of a document.

  Here, when the first image reading unit is moved to the first position, the first white plate provided at the other side position along the transport path is opposed to the first image reading unit. To do. At this time, the second white plate that moves along the transport path integrally with the first image reading unit faces the second image reading unit.

  On the other hand, when the first image reading unit moves to the second position, the first colored plate provided at the other side position along the transport path faces the first image reading unit. . At that time, the second colored plate that moves along the transport path integrally with the first image reading unit faces the second image reading unit.

  The first white plate and the second white plate are white, and the first colored plate and the second colored plate are colored with a color other than white. For this reason, if the first image reading unit is moved to the first position, it is possible to prevent the periphery of the document from being read black when the images on both the front and back sides of the document are read. If the reading unit is moved to the second position, the show-through of the document can be suppressed. In addition, according to the present invention, the second white plate and the second colored plate are moved together with the first image reading unit, so that the document show-through can be performed as described above without providing a plurality of movable members. In addition, it is possible to at least selectively suppress reading around the original in black.

  In the present invention, the mode setting unit capable of setting a show-through prevention mode for preventing show-through when reading an image of a document, and when the show-through prevention mode is set by the mode setting unit, the first And a reading drive unit that moves the image reading unit to the second position. In this case, when a show-through prevention mode for preventing show-through when reading an image on a document is set by the mode setting unit, the reading drive unit moves the first image reading unit to the second position. Therefore, the show-through of the document can be satisfactorily suppressed by a simpler operation.

  In this case, the reading drive unit may move the first image reading unit to the first position when the show-through prevention mode is not set by the mode setting unit. In this case, when the show-through prevention mode is not set by the mode setting unit, the reading driving unit moves the first image reading unit to the first position, so that the periphery of the document is read black. Can be suppressed satisfactorily.

Further, in the case where the reading drive unit is provided as described above, the image forming apparatus further includes a transparent document table on which the document is placed, and the reading drive unit moves the first image reading unit along the document table. An operation of moving in the sub-scanning direction may also be executable. In an image reading apparatus capable of so-called flatbed (FB) reading, in which the first image reading unit is moved in the sub-scanning direction along a transparent document table on which an original is placed, the first image reading unit is the above-described In many cases, a means for moving along the transport path is provided. Therefore, when the means is used as the reading drive unit, the image reading apparatus of the present invention can be configured more easily.

1 is a cross-sectional view schematically illustrating a configuration of an image reading apparatus to which the present invention is applied. 2 is a cross-sectional view schematically illustrating a configuration in the vicinity of a reading device of the image reading apparatus. FIG. It is a block diagram showing the structure of the control system of the image reading apparatus. It is a flowchart showing the reading process in the control system. It is a flowchart showing the mode selection process in the reading process. It is sectional drawing which represents typically the modification of the structure of the said reading device vicinity.

[Entire configuration of image reading apparatus]
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing the configuration of an image reading apparatus 10 to which the present invention is applied. The image reading apparatus 10 is provided on an upper portion of a base body 20 of a multifunction machine having an image forming unit (not shown), and a document cover 30 is provided on the upper surface of the base body 20 so as to be opened and closed.

  As shown in FIG. 1, a transparent glass platen 21 on which a document P (see FIG. 2) is placed when the image reading apparatus 10 is used as a flatbed scanner is disposed on the upper end surface of the base 20. Is provided. The document cover 30 is attached to be openable and closable so as to cover the document P placed on the document table 21 by being closed on the surface of the document table 21.

  The document cover 30 is configured as a document cover having an ADF (Automatic Document Feeder), and conveys the document P placed on the sheet feeding tray 110 along the conveyance path, and functions as an ADF. The first reading device 210 and the first reading device 210 out of the second reading devices 230 that can perform image reading in parallel on the front surface and the back surface of the document P conveyed along the conveyance path are provided. The second reading device 230 is provided on the base body 20.

  The transport unit 100 includes transport rollers 121 to 129 that transport the document P placed on the paper feed tray 110 to the paper discharge tray 130 along the transport path (dotted line in FIG. 1). A first reading device 210 (an example of a second image reading unit) for reading an image on the back surface (corresponding to the other surface) of the document P is located at a position (reading position) passing through the upper portion of the substrate 20 in the transport path. ) On the side of the document cover 30, and a second reading device 230 (an example of a first image reading unit) for reading an image on the surface of the document P (corresponding to one surface) faces the substrate 20 side. Is provided.

  Further, an original detection sensor 310 for detecting the presence or absence of the original P placed on the paper feed tray 110 is provided on the transport path. The second reading device 230 is fixed to an endless belt 357 provided between a driving pulley 353 and a driven pulley 355 that are rotationally driven by a motor 351 (an example of a reading drive unit). Accordingly, the lower part of the document table 21 can be moved in the sub-scanning direction (left-right direction).

[Detailed configuration of reading device]
FIG. 2 is a cross-sectional view schematically showing an enlarged configuration in the vicinity of the reading device of the image reading apparatus 10. As shown in FIGS. 2A and 2B, the first reading device 210 includes a light source 211, a lens 212 that collects light emitted from the light source 211 and reflected by the document P, and the lens 212. The light receiving element 213 is provided to detect the light collected by. The light source 211 includes a light guide member extending in the main scanning direction (front-rear direction) and an LED lamp that emits light to the inside of the light guide member, and irradiates the document P with light in a line shape. Lens 2
12 and the light receiving elements 213 are arranged in a line along the main scanning direction. The second reading device 230 also includes the same light source 231, lens 232, and light receiving element 233.

  The first reading device 210 and the second reading device 230 include the following white reference plates 217 and 237 and black reference plates 218 and 238, respectively. A white reference plate 217 (an example of a first white plate) whose surface is colored white is a surface of the original P that is opposite to the lens 212 on the surface facing the second reading device 230 across the original P of the first reading device 210. It is provided on the upstream side in the transport direction (hereinafter simply referred to as the upstream side; the same applies to the downstream side). The white reference plate 237 (an example of the second white plate) of the second reading device 230 is on the downstream side of the lens 232 on the surface facing the first reading device 210 across the document P of the second reading device 230. Is provided. 2A, when the second reading device 230 moves to the first position where the lens 232 and the light receiving element 233 face the white reference plate 217, the white reference plate 237 has the lens 212 and the light receiving portion. It faces the element 213.

  A black reference plate 218 (an example of a first colored plate) whose surface is colored in black is on the downstream side of the lens 212 on the surface facing the second reading device 230 with the document P of the first reading device 210 interposed therebetween. Is provided. A black reference plate 238 (an example of a second colored plate) of the second reading device 230 is upstream of the lens 232 on the surface facing the first reading device 210 across the original P of the second reading device 230. Is provided. As shown in FIG. 2B, when the second reading device 230 is moved to the second position where the lens 232 and the light receiving element 233 face the black reference plate 218, the black reference plate 238 has the lens 212 and the light receiving portion. It faces the element 213.

  For this reason, if the second reading device 230 is moved to the first position, the white reference plates 237 and 217 are disposed behind the original P read by the first reading device 210 and the second reading device 230, and are small. It is possible to suppress reading around the size of the original P in black. Further, when the second reading device 230 is moved to the second position, the black reference plates 238 and 218 are disposed behind the original P read by the first reading device 210 and the second reading device 230, and the original P Show-through can be suppressed. When the second reading device 230 is disposed at the first position or the second position, the first reading device 210 and the second reading device 230 also function as the other document presser.

[Configuration of control system of image reading apparatus]
Next, FIG. 3 is a block diagram illustrating a configuration of a control system of the image reading apparatus 10. As shown in FIG. 3, the control system of the image reading apparatus 10 is configured around an ASIC 400, and a CPU 403, ROM 405, RAM 407, and NVRAM 409 are connected to the ASIC 400.

  The ASIC 400 inputs signals such as a clock signal CLK and a line start pulse signal SP to the first reading device 210 and the second reading device 230 based on a command from the CPU 403, and the above-described light source via the LED circuits 411 and 431. 211 and 231 are controlled. The analog read signals output from the light receiving elements 213 and 233 are converted into digital signals by AFEs (analog front ends) 413 and 433 and then input to the ASIC 400. Further, the ASIC 400 controls the motor 453 that drives the above-described conveyance rollers 121 to 129 (see FIG. 1) via the drive circuit 451, and controls the above-described motor 351 via the drive circuit 461, thereby Also, signals from an operation panel 470 (an example of a mode setting unit) provided in the above and a document detection sensor 310 (see FIG. 1) described above are also input.

[Processing in the control system]
Next, processing executed by the CPU 403 based on a program stored in the ROM 405 in the control system will be described. FIG. 4 shows the CPU 100 when an instruction to read a document image is given.
6 is a flowchart illustrating a reading process executed by the user. As shown in FIG. 4, in this process, first, in S1 as an example of the mode setting unit (S represents a step: the same applies hereinafter), the operation state of the operation panel 470 and the detection signal of the document detection sensor 310 described above. Based on the above, the reading mode is set. In S1, setting of a show-through removal mode (an example of a show-through prevention mode) for removing show-through when reading a thin paper document P or the like is made according to the user's desire.

  In the subsequent S3, it is determined whether or not the reading mode is the duplex mode. If the reading mode is not the duplex mode (S3: N), it is determined whether or not the document table reading is performed in S5. When the reading mode set in S1 is original plate reading (S5: Y), the process proceeds to S7, and the motor 351 is driven via the drive circuit 461, whereby the original of the second reading device 230 is read. Movement in the sub-scanning direction along the table 21 is started. In the subsequent S9, the one-side reading process by the second reading device 230 is executed during the movement, and when the second reading device 230 moves to the end of the document table 21 and the one-side reading process is completed, the process is temporarily ended. To do.

  On the other hand, if it is determined in S5 that the document table is not read (S5: N), the process proceeds to S10, and the following mode selection process is executed. FIG. 5 is a flowchart showing the mode selection process in detail. As shown in FIG. 5, in this process, first, in S11, it is determined whether or not the show-through removal mode is set in S1 described above. If the show-through removal mode is set (S11: Y), the process proceeds to S12, where the second reading device 230 faces the black reference plate 218 of the first reading device 210 (that is, the aforementioned first position). 2), the process proceeds to S20 (see FIG. 4). On the other hand, if it is determined in S11 that the show-through removal mode is not set (S11: N), the process proceeds to S13, and the second reading device 230 is connected to the white reference plate 217 of the first reading device 210. After moving to the opposite reading position (that is, the first position described above), the process proceeds to S20.

  Returning to FIG. 4, in S20, the motor 453 is driven via the drive circuit 451, whereby the conveyance of the document P to be read is started, and the process proceeds to S9 described above. Then, the single-sided reading process of the original P is executed via the second reading device 230 that is fixedly arranged at the first position or the second position, and the conveyance of the original P is completed and the single-sided reading process is completed. When the process ends, this process is temporarily ended.

  If it is determined in S3 that the reading mode set in S1 is the duplex mode (S3: Y), the process proceeds to S30, and the mode selection process similar to S10 described above is executed. . In subsequent S40, the original P to be read is conveyed and the double-sided reading of the original P is performed via the second reading device 230 and the first reading device 210 which are fixedly arranged at the first position or the second position. When the process is executed and the conveyance of the original P is completed and the double-sided reading process is completed, the process is temporarily terminated.

[Effects and Modifications of Embodiment]
As described above, in the image reading apparatus 10 according to the present embodiment, when the show-through removal mode is set (S11: Y), the second reading device 230 is moved to the second position and the back side of the document P is moved. If the show-through removal mode is not set (S11: N), the second reading device 230 is moved to the first position and the periphery of the small-size document P is read black. Can be suppressed. In addition, a configuration for enabling such an operation is also provided by providing the first reading device 210 and the second reading device 230 with white reference plates 217 and 237 and black reference plates 218 and 238, and a motor for reading the document table. This can be realized by moving the second reading device 230 to the first position or the second position using 351.

Therefore, in the present embodiment, it is possible to at least selectively suppress the show-through of the document P and the reading of the periphery of the document P in black without providing a plurality of movable members. In addition, the image reading apparatus 10 of the present embodiment can be configured extremely easily using the existing motor 351.

  In addition, this invention is not limited to the said embodiment at all, It can implement with a various form in the range which does not deviate from the summary of this invention. For example, the arrangement of the white reference plates 217 and 237 and the black reference plates 218 and 238 can be variously changed. In FIG. 6, the white reference plate 217 and the black reference plate 218 of the first reading device 210 are sequentially arranged on the downstream side of the lens 212, and the white reference plate 237 and the black reference plate 238 of the second reading device 230 are arranged. The example arrange | positioned sequentially in the upstream of the lens 232 is represented.

  Also in this case, when the second reading device 230 is moved to the first position where the lens 232 and the light receiving element 233 face the white reference plate 217, the white reference plate 237 is moved to the lens 212 as shown in FIG. When the second reading device 230 is moved to the second position where the lens 232 and the light receiving element 233 face the black reference plate 218, the black reference plate is moved as shown in FIG. 238 faces the lens 212 and the light receiving element 213. Therefore, also in this case, the same effect as that of the above-described embodiment is produced. Further, in this example, as compared with the above-described embodiment, there is an effect that a movement distance when the second reading device 230 is moved between the first position and the second position can be reduced.

  Furthermore, the first colored plate and the second colored plate of the present invention may be colored in other colors such as gray, and if the lightness behind the original P is slightly reduced, the effect of suppressing the show-through to some extent is obtained. Arise. The present invention can also be applied to an image reading apparatus dedicated to ADF reading in which the second reading device 230 is not moved by the motor 351. In that case, instead of providing the motor 351, either the first reading device 210 or the second reading device 230 may be manually moved along the conveyance direction of the document P. Furthermore, the white reference plate 217 and the black reference plate 218 may be configured separately from the first reading device 210.

DESCRIPTION OF SYMBOLS 10 ... Image reading apparatus 20 ... Base | substrate 21 ... Document stand 30 ... Document cover 100 ... Conveying part 210 ... 1st reading device 211,231 ... Light source 212,232 ... Lens 213,233 ... Light receiving element 217,237 ... White reference board 218 , 238 ... Black reference plate 230 ... Second reading device 310 ... Document detection sensor 351, 453 ... Motor 400 ... ASIC 403 ... CPU
405 ... ROM 407 ... RAM
470 ... Operation panel P ... Original

Claims (4)

A document which is provided on one side facing the document conveyance path so as to be movable between at least a first position and a second position along the conveyance path, and is conveyed along the conveyance path. A first image reading unit that reads an image on one side of
A second image reading unit that is immovably provided on the other side facing the conveyance path and reads an image on the other side of the document conveyed along the conveyance path;
A white first white plate provided at a position on the other side along the conveyance path and facing the first image reading unit when the first image reading unit is moved to the first position;
Provided at the position on the other side along the conveyance path, and when the first image reading unit moves to the second position, it is colored with a color other than white that faces the first image reading unit. A first colored plate;
When the first image reading unit moves along the conveyance path integrally with the first image reading unit and the first image reading unit is disposed at the first position, a second white color that faces the second image reading unit. A white plate,
When the first image reading unit moves along the conveying path integrally with the first image reading unit and the first image reading unit is disposed at the second position, the color other than white facing the second image reading unit A second colored plate colored with,
An image reading apparatus comprising: A mode setting unit capable of setting a show-through prevention mode for preventing show-through when reading an image of a document;
A reading drive unit that moves the first image reading unit to the second position when the show-through prevention mode is set by the mode setting unit;
The image reading apparatus according to claim 1, further comprising:   3. The image according to claim 2, wherein the reading drive unit moves the first image reading unit to the first position when the show-through prevention mode is not set by the mode setting unit. Reader. A transparent platen on which the document is placed,
In addition,
4. The image reading apparatus according to claim 2, wherein the reading drive unit can also perform an operation of moving the first image reading unit in the sub-scanning direction along the document table.

Images