JP2010206343A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correctly read an original image of an original placed on a platen glass, and delete troublesome work to replace the original even when the original is not correctly placed in a reference position determined beforehand. <P>SOLUTION: An image reading apparatus 1 reads the original image of the original 9 placed on a platen glass 21, and includes: original position detection sensors 4a to 4d that detect to which one of four corner parts of the platen glass 21 the original 9 correctly touches and is placed; main/sub scanning length detection sensors 5a to 5v which detect the original size, making a corner part to which the original is touched, as a reference point out of four corner parts; and an image correction unit 11 which corrects the image data read out based on the original size detected by the main/sub scanning length detection sensors 5a to 5v when the original 9 is placed in a condition that it touches to a corner part other than the reference position out of the four corner parts. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that reads a document image of a document placed on a platen glass, and more particularly to a device that has a document size reading function and a read image data correction function.

  2. Description of the Related Art Conventionally, an image reading apparatus in a copying machine or a multifunction machine scans an original placed on a platen glass with an exposure optical system, forms an image on a rotating photosensitive drum, and forms the original on the photosensitive member. A latent image is formed. In recent years, an apparatus that forms an image of a document on an image pickup device such as a CCD to acquire image data, and then performs image exposure on a photosensitive drum using a semiconductor laser or the like is becoming widespread.

  When reading a document image using these devices, it is necessary to place the document against the reference position on the platen glass, but if the user is in a hurry or is unfamiliar with the operation, In some cases, reading is started in a state where the document is not correctly placed, and the paper is wasted.

  Therefore, for example, Patent Document 1 discloses a detection sensor for detecting the size of a document placed on a platen glass, a linear light emitting display arranged along the short side of the platen glass, and a light emitting display. A document positioning instruction device has been proposed that includes a light emission control unit that expands and contracts the light emitting area length of the device and displays the correct placement position. This apparatus is configured to display a warning message indicating that the placement position is not correct and prompt the user to reposition the original when the original is not placed in accordance with the light emitting area of the light emitting display.

  Further, Patent Document 2 includes a line number detection unit that detects the number of lines of read data, a data amount detection unit that detects a data amount after encoding of the read data, and a warning unit that gives a warning to the user. A facsimile machine has been proposed. In this apparatus, when a document image is read, the amount of code data per line of the document is compared with a predetermined reference value, and a warning is issued when the amount of code data is smaller than the reference value.

  Further, Patent Document 3 detects the position of the original on the platen glass based on the image data obtained by forming the original image on the CCD, and the detected position of the original is input to the control unit in advance. There has been proposed an image forming apparatus that determines whether or not a document is correctly placed in comparison with document reference position data.

  This apparatus is configured to issue a warning that a document is not correctly placed when the document is placed so that the document position cannot be detected from the image data. If the document placement position is deviated within the range in which the document position can be detected from the image data, the amount of displacement is calculated from the comparison result between the detected document position and the document reference position data, and the image data Is configured to correct.

JP-A-8-069160 JP-A-6-046185 JP 2003-075942 A

  However, the apparatuses described in Patent Documents 1 and 2 merely issue a warning to the user and are not provided with correction means on the apparatus side. There was a problem that it had to be repositioned correctly.

  On the other hand, since the apparatus described in Patent Document 3 has a function of correcting image data in accordance with the amount of positional deviation, if the degree of deviation is small, the document is not forced to be repositioned. However, in this apparatus, since the original image is formed on the CCD and the original is detected, as shown in FIG. 13, only when the original 70 is placed on the home position side of the optical module 71 on which the CCD is mounted. Only the presence or absence of the document 70 can be detected correctly. For this reason, there is a problem that applicable devices are limited and versatility is poor.

  The apparatus described in Patent Document 3 has a function of arranging a plurality of sensors (document longitudinal length detection sensors) along the longitudinal direction of the platen glass and detecting the size of the placed document. Since the sensor is arranged on the assumption that the document is correctly placed, there is a problem that the size cannot be detected correctly depending on the placement position of the document.

  Therefore, the present invention has been made in view of the above problems in the prior art, and is placed on the platen glass even when the document is not placed against the predetermined reference position. An object of the present invention is to provide an image reading apparatus that can correctly read a document image of a document and eliminate the troublesomeness of replacing the document.

  In order to achieve the above object, the present invention provides an image reading apparatus for reading a document image of a document placed on a platen glass, wherein the document hits any one of the four corners of the platen glass. A document position detecting means for detecting whether or not the document is placed, a document size detecting means for detecting a document size based on a corner of the four corners against which the document is abutted, and the four corners When the document is placed in a state of being abutted against a corner other than a predetermined reference position, the document abutting position detected by the document position detecting unit and the document size detecting unit And correction means for correcting the read image data based on the detected document size.

  According to the present invention, even when a document is placed in a state of being abutted against a corner other than a predetermined reference position, the document size can be detected correctly, and the document is abutted. It is also possible to automatically correct the image data according to the position. For this reason, it is possible to eliminate annoyance without frequently urging the user to reposition the document.

  In the image reading apparatus, the document position detecting means can be composed of a plurality of document position detecting means arranged corresponding to the four corners. According to this, the document is out of the four corners of the platen glass. It is possible to appropriately detect which one of the two has been placed.

  In the image reading apparatus, the document size detection unit includes a plurality of detection sensor groups arranged to detect the length of the document in the main scanning direction and the sub-scanning direction, corresponding to each of the four corners. They can be arranged in groups. According to this, even when the original is placed against any of the four corners, the original size can be detected appropriately.

  In the image reading apparatus, the document size detecting means determines the lengths in the main scanning direction and the sub-scanning direction when the document is placed on the center with respect to the center reference position in the main scanning direction and / or the sub-scanning direction. A detection sensor group for detection can be further provided. According to this, even when the document is placed on the center, it is possible to appropriately detect the size of the document.

  In the image reading apparatus, when the original position detecting unit detects that the original is not hitting any of the four corners, the original is not placed on the platen glass, or A warning message to the effect that the document placement position is invalid can be issued. According to this, it is possible to issue a warning only for a bag that cannot be handled, and it is possible to suppress wasteful consumption of paper while reducing requests for document repositioning.

  As described above, according to the present invention, the original image of the original placed on the platen glass can be read correctly even when the original is not placed against the predetermined reference position. It is possible to eliminate the troublesomeness of replacing the original.

1 is a perspective view illustrating a module scan type image reading apparatus. It is sectional drawing which shows the optical module of FIG. 1 is a top view showing a mirror scan type image reading apparatus. FIG. 1 is a block diagram showing an electrical configuration of an image reading apparatus according to the present invention. It is a top view for demonstrating a document position detection mechanism. It is sectional drawing of an image reading apparatus. 6 is a flowchart for explaining document detection processing; FIG. 6 is a top view showing a state where a document is placed. 6 is a flowchart for explaining a document image reading process. It is a figure for demonstrating the correction process of image data. It is a top view which shows 2nd Embodiment of the image reading apparatus concerning this invention. It is a top view which shows 3rd Embodiment of the image reading apparatus concerning this invention. FIG. 10 is a top view illustrating a relationship between an optical module and a document placement position in a conventional image reading apparatus.

  Next, modes for carrying out the invention will be described in detail with reference to the drawings. In the following, the general configuration of the image reading apparatus will be briefly described prior to the description of the image reading apparatus according to the present invention.

  FIG. 1 is a perspective view showing a module scan type image reading apparatus, FIG. 2 is a cross-sectional view showing the optical module of FIG. 1, and FIG. 3 is a top view showing a mirror scan type image reading apparatus. is there.

  As shown in FIG. 2, the optical module 30 in the module scan system has a configuration in which a CCD 31, a lens 32, a lamp 33 and a mirror 34 are integrally fixed by a frame 35. As shown in FIG. 1, the optical module 30 is disposed on a rail 39 in a state where both ends are connected to a wire 38 wound around a drum 37.

  In the image reading apparatus shown in FIG. 1, the optical module 30 is pulled by rotating the drum 37 by the motor 41 and winding the wire 38. As a result, the optical module 30 is moved in parallel with the original 9 placed on the platen glass 40, and the original 9 is read and scanned.

  In reading scanning, the original 9 is irradiated with light from the lamp 33 of the optical module 30 while moving the optical module 30. At that time, the light reflected by the document 9 is guided to the first-stage mirror 34 through the optical path 36, and is repeatedly reflected by the rear-stage mirror group 34, and then formed on the light receiving surface of the CCD 31 through the lens 32. Then, the CCD 31 performs photoelectric conversion on the formed original image and outputs an image signal corresponding to the original image.

  On the other hand, as shown in FIG. 3, in the mirror scan type image reading apparatus, the CCD 31 and the lens 32 are installed on the bottom 42 of the scanner housing, and the configuration other than the CCD and the lens (lamp 33, mirror 34, etc.) is provided. The optical module 43 is moved to read the original image. In this mirror scan type image reading apparatus, similarly to the module scan type image reading apparatus, the light reflected by the document 9 is condensed on the light receiving surface of the CCD 31 to obtain an image signal corresponding to the original image. Composed.

  Next, an embodiment of an image reading apparatus according to the present invention will be described with reference to FIGS. Here, a case where the image reading apparatus according to the present invention is applied to the module scanning type image reading apparatus shown in FIG. 1 will be described as an example.

  As shown in FIG. 4, the image reading apparatus 1 includes an open / close sensor 2 that detects opening and closing of a platen cover 22 (see FIG. 6), an angle sensor 3 that detects an inclination angle of the platen cover 22, and a document 9 abutment. Various detection sensors such as a document position detection sensor 4 for detecting the position and a main / sub-scanning length detection sensor (hereinafter referred to as “document length detection sensor”) 5 for detecting the length of the document 9 in the main scanning and sub-scanning directions. Is provided.

  Among these, the document position detection sensor 4 is composed of four sensors 4 a to 4 d as shown in FIG. 5, and is arranged corresponding to the four corners R <b> 1 to R <b> 4 of the platen glass 21. These document position detection sensors 4a to 4d are arranged so as to be located slightly outside the edge of the maximum reading size (A3 size in the case of FIG. 5).

  As the document position detection sensors 4a to 4d, for example, an optical sensor in which a light emitting unit that emits light toward the document 9 on the platen glass 21 and a light receiving unit that receives reflected light from the document 9 are used as a pair. be able to. The document position detection sensors 4a to 4d are arranged, for example, at the bottom of the scanner housing so as not to hinder the movement operation of the optical module 30 (see FIG. 6).

  As shown in FIG. 5, the document length detection sensor 5 is composed of 20 sensors including sensors 5 a to 5 v, and the plurality of detection sensors 5 a to 5 v includes any one of the four corners R <b> 1 to R <b> 4. Is placed so as to detect the size of the document 9 (for example, B5, A4, B4 and A3 sizes). That is, one set of detection sensor groups arranged so that the document size can be discriminated with respect to one corner (for example, R1) is set in correspondence with the other corners (R2 to R4). Min) It has the arranged configuration.

  Therefore, for example, as shown by a broken line in FIG. 5, when an A4 size document 9 is placed against the corner R1, the output of the document position detection sensor 4a corresponding to the corner R1 and the document Based on the outputs of the length detection sensors 5k, 5m, 5n and 5p, the main scanning length of the document 9 can be detected, the output of the document position detection sensor 4a, and the outputs of the document length detection sensors 5h and 5p. Based on the above, the sub-scanning length of the document 9 can be detected.

  As another abutment example, for example, as shown by a one-dot chain line in FIG. 5, when a B4 size document 9 is abutted and placed on the corner R3, the document position detection sensor 4c corresponding to the corner R3. And the output of the document length detection sensors 5c and 5d, the main scanning length of the document 9 can be detected, the output of the document position detection sensor 4c, and the output of the document length detection sensors 5c and 5t. Based on the above, the sub-scanning length of the document 9 can be detected.

  The number of document length detection sensors 5 is not limited to 20, but can be changed as appropriate. Similarly to the document position detection sensor 4, the document length detection sensor 5 can be constituted by an optical sensor, for example, and both are arranged at positions that do not hinder the movement operation of the optical module 30 (FIG. 6). reference).

  Returning to FIG. 4, the image reading apparatus 1 has a configuration other than the above-described detection sensor, an image processing unit 10 that performs predetermined signal processing on an image signal output from the CCD 31 and outputs image data, and a document 9. Based on the position and the size of the document 9, the image correction unit 11 edits the image data output from the image processing unit 10 into image data equivalent to the case where the document 9 is placed at the butting reference position R1, and the image Operation of the image reading apparatus 1 as a whole, a memory unit 12 for storing image data edited by the correction unit 11, a display 13 for displaying a predetermined warning message, a button key, and the like. And a control unit 15 for comprehensively controlling the above.

  Next, the operation of the image reading apparatus 1 having the above configuration will be described.

  When the platen cover 22 shown in FIG. 6 is rotated in the opening direction, the opening / closing sensor 2 detects the opening operation of the platen cover 22, and the controller 15 detects the current to the document position detection sensor 4 and the document length detection sensor 5. To turn on.

  When the inclination angle of the platen cover 22 reaches 10 to 20 degrees in the process of rotating the platen cover 22 in the closing direction after the user places the document 9 on the platen glass 21, the angle sensor 3 detects this. In response to this, detection processing for the presence / absence and size of the document 9 is started.

  In the detection process, as shown in FIG. 7, first, the presence / absence of the document 9 (the presence of an object above the sensor) is detected by the document position detection sensors 4a to 4d arranged at the four corners on the platen glass 21 ( Step S1). Next, based on the outputs of the document position detection sensors 4a to 4d, it is determined whether or not the number of document position detection sensors 4 that have detected the presence of the document 9 is two or more (step S2).

  At this time, for example, as shown in FIG. 8A, when the document 9 larger than the maximum reading size is placed on the platen glass 21, all of the document position detection sensors 4a to 4d Existence is detected (step S2: Yes). In this case, it is determined that the placed document 9 is a large-size document, and the process is terminated (step S3).

  On the other hand, if the number of document position detection sensors 4 that have detected the presence of the document 9 is less than two (1 or 0) (step S2: No in FIG. 7), the presence of the document 9 is determined. It is determined whether or not the number of detected document position detection sensors 4 is 0 (whether any of the document position detection sensors 4a to 4d could detect the presence of the document 9) (step S4). As a result, if the document position detection sensor 4 that has detected the presence of the document 9 does not exist (step S4: Yes), the outputs of the document length detection sensors 5a to 5v are referred to, and those outputs are the same as those of the document 9. It is determined whether or not it is present (step S5).

  If the presence of the document 9 cannot be detected by the document length detection sensors 5a to 5v, a warning message indicating that the document 9 is not placed is displayed (step S6). If the presence of the document 9 can be detected by any of 5a to 5v, a warning message indicating that the placement position of the document 9 is invalid is displayed (step S7).

  On the other hand, when the presence of the document 9 is detected by one of the document position detection sensors 4a to 4d (step S4: No), the output of the document position detection sensor 4a installed corresponding to the reference position R1. In step S8, it is determined whether or not the document 9 is placed in a state where it is in contact with the reference position R1.

  At this time, for example, when the document 9 is placed in the state shown in FIG. 8B and the document 9 is abutted against the reference position R1 (step S8: Yes in FIG. 7), the document position detection sensor. Based on the output of 4a and the outputs of the document length detection sensors 5a to 5v, the length of the document 9 in the main / sub scanning direction is detected, and the document size (A4 size in the case of FIG. 8B) is determined. Confirm (step S9).

  On the other hand, for example, as shown in FIG. 8C, the document 9 is placed in a state of being abutted against the corner R3 other than the reference position R1, and the sensor of the document 9 is detected by a sensor other than the document position detection sensor 4a. When the presence is detected (step S8 in FIG. 7: No), the output of the document position detection sensor (in the case of FIG. 8C, the document position detection sensor 4c) that detects the presence of the document 9, and the document length Based on the outputs of the detection sensors 5a to 5v, the length of the document 9 in the main / sub scanning direction is detected, and the document size (A4 size in the case of FIG. 8C) is determined (step S10).

  With the above processing, the original size can be determined before the original image is read, regardless of which corner portion the original 9 is placed against. The advantage that the document size can be determined before reading the document image is as follows. That is, it is possible to quickly present the document size to the user, and in the case of a copy operation, an automatic paper selection function (APS function) in which the apparatus selects a tray of the optimum size from the determined size, An automatic magnification selection function (AMS function) that automatically reduces / enlarges the document size determined to fit the paper size of the selected tray to the optimum magnification is used to present the output size and magnification to the user before execution. It becomes possible.

  When the detection process of the presence / absence and size of the document 9 is completed, the results are displayed on the display 13. If the user depresses the start key 16 because there is no problem in the detection result, the document image reading process is started.

  When the reading process is started, in the image reading apparatus 1, as shown in FIG. 9, it is determined in step S8 shown in FIG. 7 whether or not the document 9 is placed in a state of abutting against the reference position R1. The determination result is used (step S11). If the document 9 is in contact with the reference position R1 (see FIG. 8B), the image data that has undergone signal processing in the image processing unit 10 is stored in the memory unit 12 without being processed as it is (see FIG. 8B). Step S12).

  On the other hand, when the document 9 is placed in a state of being abutted against a corner other than the reference position R1 (see FIG. 8C), as shown in FIG. In FIG. 9, the image data is corrected so as to cut out the data (x1 area) for the size detected from the abutting position, or delete the excess data (x2 area), and store it in the memory unit 12 (FIG. 9). Step S13).

  In the image data processing described above, when the document 9 is placed against the reference position R1, the image data is stored without being processed. However, the document 9 is brought into contact with the reference position R1. Even when the document is placed, as shown in FIG. 10B, the image data may be corrected so as to cut out data corresponding to the document size (y1 region) or delete an extra region (y2 region). .

  As described above, according to the present embodiment, since the document size of the document 9 can be detected even when the document 9 is placed in a state of being abutted against the corner other than the reference position R1, the document 9 can be detected. The document size can be promptly detected as long as it hits one of the corners. In addition, since the image data is corrected based on the detected document size as necessary, it is possible to eliminate annoyance without frequently urging the user to reposition the document 9.

  Further, only when it is detected that the document 9 does not hit any of the four corners, the document 9 is not placed on the platen glass 21 or the document 9 is placed in an incorrect position. Since the warning message is displayed, a warning can be issued only for a trap that cannot be handled. As a result, it is possible to suppress wasteful consumption of paper while reducing the number of requests for replacing the original 9.

  Next, a second embodiment of the image reading apparatus according to the present invention will be described with reference to FIG.

  The image reading apparatus according to the present embodiment is capable of detecting the size of the document 9 and reading the document image even when the document 9 is placed on the center with reference to the center reference position CR1 in the sub-scanning direction. . As shown in FIG. 11A, the image reading device 50 has a configuration in which document length detection sensors 51a to 51e are added to the image reading device 1 shown in FIG. These document length detection sensors 51a to 51e are arranged, for example, corresponding to the case where a B5, A4, B4, and A3 size document 9 is placed on the center according to the center reference position CR1.

  In the image reading device 50, when the document 9 is placed in the state of FIG. 11B, any of the outputs of the document position detection sensors 4a to 4d indicates a state where the document 9 is not placed. Therefore, it can confirm that it is not mounted by the corner butting. At this time, by adding the outputs of the document length detection sensors 5a to 5v and 51a to 51e to the determination condition, the document 9 is not present on the platen glass 21, or the document is not in contact with the four corners R1 to R4. It is possible to determine whether 9 is mounted.

  Further, referring to the outputs of the document length detection sensors 5a to 5v (see FIG. 5) and the document length detection sensors 51a to 51e, the main scanning length and the sub scanning length of the document 9 can be detected, and the document size can be set. Can be determined. After that, as in the case of the first embodiment, the image data is corrected according to the detected position and size of the document 9.

  Next, a third embodiment of the image reading apparatus according to the present invention will be described with reference to FIG.

  The image reading apparatus according to the present embodiment is capable of detecting the size of the document 9 and reading the document image even when the document 9 is placed on the center with reference to the center reference position CR2 in the main scanning direction. . As shown in FIG. 12, the image reading device 60 has a configuration in which document length detection sensors 61a to 61c are added to the image reading device 1 shown in FIG. These document length detection sensors 61a to 61c are arranged corresponding to the case where documents 9 of various sizes are placed on the center according to the center reference position CR2.

  The embodiment of the present invention has been described above, but the present invention is not limited to the above-described configuration, and various modifications can be made within the scope of the invention described in the claims.

  For example, in the above-described embodiment, the case where the image reading apparatus according to the present invention is applied to a module scan type image reading apparatus is illustrated, but the present invention can also be applied to a mirror scan type image reading apparatus. Is possible.

  In the above-described embodiment, the configuration that can handle center placement at the center reference position CR1 and the configuration that can support center placement at the center reference position CR2 have been described separately. A device that can handle both the center reference positions CR1 and CR2 can also be configured.

DESCRIPTION OF SYMBOLS 1 Image reading apparatus 2 Open / close sensor 3 Angle sensor 4 (4a-4d) Original position detection sensor 5 (5a-5v) Main / sub scanning length detection sensor (original length detection sensor)
9 Document 10 Image processing unit 11 Image correction unit 12 Memory unit 13 Display 14 Operation panel 15 Control unit 16 Start key 21 Platen glass 22 Platen cover 30 Optical module 31 CCD
32 Lens 33 Lamp 34 Mirror 35 Frame 36 Optical path 37 Drum 38 Wire 39 Rail 40 Platen glass 41 Motor 42 Bottom 43 Optical module 50 Image reading device 51 (51a to 51e) Document length detection sensor 60 Image reading device 61 (61a to 61c) Document length detection sensor R1 Reference position R2 to R4 Corner CR (CR1, CR2) Center reference position

Claims (5)

An image reading device for reading a document image of a document placed on a platen glass,
Document position detection means for detecting whether the document is placed in a state of being abutted against any of the four corners of the platen glass,
A document size detecting means for detecting a document size with reference to a corner of the four corners on which the document is abutted;
The document abutment position detected by the document position detection means and the document size when the document is placed in a state of being abutted against a corner other than a predetermined reference position among the four corners An image reading apparatus comprising: correction means for correcting read image data based on a document size detected by a detection means.   The image reading apparatus according to claim 1, wherein the document position detection unit includes a plurality of document position detection units arranged corresponding to the four corners.   The document size detection means is configured by arranging a plurality of sets of detection sensor groups arranged to detect the length of the document in the main scanning direction and the sub-scanning direction, corresponding to each of the four corners. The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus.   The document size detection means is a detection sensor for detecting the length in the main scanning direction and the sub-scanning direction when the document is placed on the center with reference to the center reference position in the main scanning direction and / or the sub-scanning direction. The image reading apparatus according to claim 3, further comprising a group.   When the original position detecting means detects that no original is hitting any of the four corners, it means that no original is placed on the platen glass, or the original placement position is 4. The image reading apparatus according to claim 1, wherein a warning message to the effect of fraud is issued.

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