JP2018198350A - Image reading device, image forming apparatus, control program, and control method - Google Patents

Abstract

CONSTITUTION: An image reading device 10 comprises a light source 70 including a plurality of light emitting parts 82, and receives light reflected from an object with an imaging element 78 to read an image of the object. The image reading device includes a streak data storage part 108 that stores streak data set in advance on the basis of the arrangement of the light emitting parts, determines whether banded white streaks occur in a scanned image by using the streak data (S3), and when the white streaks occur, reduces the quantity of light from the light source and executes re-scanning processing (S7, S1).EFFECT: The occurrence of banded white streaks can be prevented without increasing a burden on a user performing operations.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an image reading apparatus, an image forming apparatus, a control program, and a control method, and more particularly to an image reading apparatus, an image forming apparatus, a control program, and a control method capable of reading an image of an object such as a glossy object.

  2. Description of the Related Art Conventionally, an image reading apparatus that reads an image of an object by irradiating an object (original) from a light source and converting the reflected light into an electric signal by an image sensor is known. In such an image reading apparatus, when attempting to read a three-dimensional glossy object such as a metal product, the reflected light from the glossy object is partially increased, and the scanned image may be defective, such as white spots. .

  Therefore, as an example of a conventional image reading apparatus, there is one having a glossy object scan mode for reading a glossy object. When the user reads a glossy object, the user can select a glossy object scan mode and set the light amount according to the glossy object, thereby reducing the occurrence of defects such as white spots in the scanned image. However, such an operation of setting the light amount is a burden on the user.

  On the other hand, Patent Document 1 discloses another example of a conventional image reading apparatus. In the technique of Patent Document 1, pre-scanning is performed when an image of an object is read, and at least one of an empty transfer area, a light shield area, and an effective pixel area outside the image area on a CCD line sensor (imaging device) is detected. The signal level is compared with a predetermined level. When the signal level is higher than a predetermined level, the influence on the image quality due to the overflow of the CCD line sensor is mitigated by controlling the light amount of the light source that irradiates the document during the main scan.

Japanese Patent Laid-Open No. 9-284549

  An array type light source in which a plurality of LEDs (light emitting units) are arranged in the main scanning direction may be used as a light source for irradiating the object with light. When a glossy object is scanned using such an array-type light source, striped white stripes are formed in the scan image that are arranged at predetermined intervals in the main scanning direction and extend in the sub-scanning direction, as shown in FIG. There is a case.

  However, in the technique of Patent Document 1, excessive charge overflows from the photoelectric conversion element of the target pixel of the CCD due to strong reflected light from the target and overflows outside the effective area of the rear portion of the CCD, resulting in white stripes. However, it is only possible to deal with it, and no consideration is given to the treatment for striped white stripes.

  Therefore, a main object of the present invention is to provide a novel image reading apparatus, image forming apparatus, control program, and control method.

  Another object of the present invention is to provide an image reading apparatus, an image forming apparatus, a control program, and a control method capable of preventing or suppressing the occurrence of striped white stripes without increasing the operation burden on the user. .

  The first invention includes a plurality of light emitting units arranged at predetermined intervals in the main scanning direction, a light source that irradiates the object, a reflected light from the object irradiated from the light source, and the object An image sensor that reads an image of the image, a muscle data storage unit that stores muscle data that is set in advance based on the arrangement of the light emitting unit, and a muscle that is stored in the muscle data storage unit, When the white line is determined to be generated by the line determination unit and the line determination unit, the image sensor is irradiated with light whose amount of light has been reduced, It is an image reading apparatus provided with the control part which performs the rescan process which reads the image of this again.

  In the first invention, the image reading apparatus includes a light source in which a plurality of light emitting units are arranged so as to be arranged at a predetermined interval in the main scanning direction, and the reflected light from the object is received by the image sensor, so that the object is scanned. The image is read. The image reading apparatus includes a muscle data storage unit that stores muscle data set in advance based on the arrangement of the light emitting units, and uses this muscle data to determine whether or not white stripes are generated in the scanned image. Determine. For example, the bright spot interval of the light source based on the arrangement of the light emitting unit is stored as the stripe data, and when the striped white stripe is detected in the scan image, the white stripe interval matches the bright spot interval. It is determined that striped white stripes resulting from the object being a glossy object are generated in the scanned image. Then, the control unit of the image reading device performs re-scanning by causing the image sensor to read the image of the object again by irradiating light with a light amount reduced from the light source when white stripes are generated in the scan image. Execute the process.

  According to the first aspect of the present invention, it is determined whether or not white stripes are generated in the scan image using the stripe data set in advance based on the arrangement of the light emitting units of the light source. It is possible to appropriately determine the presence or absence of striped white stripes resulting from being an object. If striped white stripes occur, the amount of light from the light source is reduced and the rescan process is executed. Therefore, the occurrence of striped white stripes can be reduced without increasing the operation burden on the user. Can be appropriately prevented or suppressed.

  The second invention is dependent on the first invention, and the control unit of the image reading apparatus determines that the white line is not generated by the line determination unit or the light amount of the light source is a preset minimum. Until the reference value is reached, the light quantity of the light source is decreased stepwise and the rescan process is repeated.

  According to the second aspect of the invention, since the light amount of the light source can be automatically adjusted to an appropriate light amount according to the object, generation of white stripes can be appropriately prevented or suppressed while maintaining the image quality of the scanned image. .

  The third invention is dependent on the first or second invention, and the control unit of the image reading apparatus performs the rescan process even when the rescan process is performed in a state where the light amount of the light source is lowered to the preset minimum reference value. When the streak determination unit determines that white stripes are generated in the scanned image, a message that prompts the user to change the orientation of the object is displayed on the display unit.

  According to the third aspect of the invention, even when the striped white stripes are not eliminated by the light amount control of the light source, the occurrence of white stripes may be prevented or suppressed.

  A fourth invention is dependent on any one of the first to third inventions, and the control unit of the image reading apparatus executes a rescan process in a state where the light amount of the light source is lowered to a preset minimum reference value. In addition, when the streak determination unit determines that white stripes are generated in the rescanned image, it notifies that white stripes are generated.

  According to the fourth aspect of the invention, it is possible to notify the user that white stripes are generated even though the light amount is adjusted.

  A fifth invention is dependent on any one of the first to fourth, and the control unit of the image reading apparatus performs only a predetermined area including an image area in which a white stripe is generated when the rescan process is executed. Reduce the light intensity of the light source.

  According to the fifth aspect, the light amount of the light source is reduced only in a predetermined region including an image region where white stripes are generated. Therefore, a normal scan image can be obtained for an image region where the light amount of the light source is not reduced. it can.

  A sixth invention is an image forming apparatus including the image reading apparatus according to any one of the first to fifth inventions.

  According to the sixth aspect of the invention, the same operational effects as those of any of the first to fifth aspects of the invention can be achieved, and the occurrence of striped white stripes can be appropriately prevented or suppressed without increasing the operation burden on the user. .

  The seventh invention has a plurality of light emitting units arranged at predetermined intervals in the main scanning direction, receives a light source that irradiates the object, and reflected light from the object of the light emitted from the light source, and A control program executed by a processor of an image reading apparatus including an image sensor for reading an image of an object and a streak data storage unit that stores streak data set in advance based on the arrangement of the light emitting unit. Using the muscle data stored in the muscle data storage unit, the muscle determination unit that determines whether or not the white stripes are generated in the image read by the image sensor, and the white line is generated by the determination unit. When it is determined that the image is detected, the control program causes the light source to emit light with a reduced amount of light, and causes the image sensor to read the image of the object again and to function as a control unit that executes a rescan process.

  The eighth invention has a plurality of light emitting units arranged at predetermined intervals in the main scanning direction, receives a light source that irradiates the object, and reflected light from the object of the light emitted from the light source, and receives the object An image reading apparatus control method comprising: an image sensor that reads an image of an object; and a line data storage unit that stores line data set in advance based on the arrangement of the light emitting unit. When the image data read by the image sensor is used to determine whether or not white stripes have occurred in the image read by the image sensor, and when the white stripes have occurred in the image read by the image sensor This is a control method for executing re-scan processing by irradiating light with a light amount reduced from the light source and causing the image sensor to read the image of the object again.

  According to the seventh or eighth invention, the same effects as those of the first invention can be obtained, and the occurrence of striped white stripes can be appropriately prevented or suppressed without increasing the operation burden on the user.

  According to the present invention, since it is determined whether or not white stripes are generated in the scan image using the stripe data set in advance based on the arrangement of the light emitting portions of the light source, the object is a glossy object. It is possible to appropriately determine the presence or absence of striped white stripes resulting from the existence. If striped white stripes occur, the amount of light from the light source is reduced and the rescan process is executed. Therefore, the occurrence of striped white stripes can be reduced without increasing the operation burden on the user. Can be appropriately prevented or suppressed.

  The above object, other objects, features, and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

1 is an illustrative view showing an image forming apparatus including an image reading apparatus according to a first embodiment of the present invention. FIG. 2 is an illustrative view schematically showing an internal configuration of the image reading apparatus in FIG. 1. FIG. 2 is an illustrative view schematically showing a light source provided in the image reading apparatus of FIG. 1. FIG. 2 is a block diagram illustrating an electrical configuration of the image reading apparatus in FIG. 1. FIG. 3 is an illustrative view showing one example of a memory map of a RAM shown in FIG. 2. FIG. 2 is a flowchart illustrating an example of scan processing of the image reading apparatus in FIG. 1. It is a flowchart which shows an example of the scanning process of the image reading apparatus of 2nd Example of this invention. It is an illustration figure which shows an example of the message displayed on the display part with which the image reading apparatus of 2nd Example is provided. It is an illustration figure for demonstrating an example of the scanning process in the image reader of 3rd Example of this invention. It is an illustration figure which shows typically a mode that the striped blank stripe was produced in the scan image of the glossy object.

[First embodiment]
FIG. 1 is an illustrative view showing an example of an image forming apparatus 100 including an image reading apparatus 10 according to the first embodiment of the present invention. An image forming apparatus 100 shown in FIG. 1 is a multifunction peripheral (MFP) having a copying function, a printer function, a scanner function, a facsimile function, and the like. However, the image forming apparatus 100 only needs to include the image reading apparatus 10 (scanner function) that reads an image of an object such as a paper document and a glossy object, and the other functions described above can be arbitrarily employed.

  First, the basic configuration of the image forming apparatus 100 will be schematically described. As shown in FIG. 1, the image forming apparatus 100 includes an apparatus main body 12 and an image reading apparatus 10 disposed above the apparatus main body 12.

  The apparatus main body 12 includes a control unit 14 including the CPU 102 and the image forming unit 16. The control unit 14 transmits a control signal to each part of the image forming apparatus 100 according to an input operation to the operation unit 18 (see FIG. 4) such as a touch panel, and causes the image forming apparatus 100 to perform various operations. . The control unit 14 is also a control unit of the image reading apparatus 10 in order to control the entire image forming apparatus 100.

  The image forming unit 16 includes an exposure unit 20, a developing unit 22, a photosensitive drum 24, a cleaner unit 26, a charger 28, an intermediate transfer belt unit 30, a transfer roller 32, a fixing unit 34, and the like. An image is formed on the conveyed paper, and the paper on which the image has been formed is discharged to a paper discharge tray 38. As image data for forming an image on a sheet, image data (scanned image data) read by an image reading unit 60 described later, image data transmitted from an external computer, or the like is used.

  Note that image data handled in the image forming apparatus 100 corresponds to four color images of black (K), cyan (C), magenta (M), and yellow (Y). For this reason, each of the developing device 22, the photosensitive drum 24, the cleaner unit 26, and the charger 28 is provided so as to form four types of latent images corresponding to the respective colors, thereby providing four image stations. Composed.

  In the apparatus main body 12, a first paper transport path L1 is formed for sending paper from the paper feed tray 36 and the like to the paper discharge tray 38 via the registration roller 40, the transfer roller 32, and the fixing unit 34. The In addition, when performing duplex printing on a sheet, the sheet after the one-side printing is finished and passed through the fixing unit 34 is returned to the first sheet conveyance path L1 on the upstream side of the transfer roller 32 in the sheet conveyance direction. The second paper transport path L2 is formed. In the first paper transport path L1 and the second paper transport path L2, a plurality of transport rollers are provided as appropriate to supplementarily provide a driving force to the paper.

  Referring to FIG. 2 together with FIG. 1, the image reading apparatus 10 can read an image of a three-dimensional glossy object such as a metal product in addition to a general paper document, and is formed of a transparent material. A document table 50 is provided. A document pressing cover 52 is attached to the upper side of the document placing table 50 through a hinge or the like so as to be freely opened and closed. The document pressing cover 52 is provided with an ADF (automatic document feeder) 58 that automatically feeds documents placed on the document placing tray 54 one by one to the image reading position 56. An operation unit 18 that receives an input operation such as a print instruction by a user is provided on the front side of the document table 50. The operation unit 18 includes a display with a touch panel (display unit) and various operation buttons.

  Further, the image reading apparatus 10 includes an image reading unit 60 including a light source unit 62, a mirror unit 64, a sensor unit 66, and the like.

  The light source unit 62 includes a light source 70, a reflection mirror 72, and the like. As shown in FIG. 3, the light source 70 includes a long plate-like substrate 80 that extends in the main scanning direction (in this embodiment, the front-rear direction of the image reading apparatus 10). The substrate 80 is provided with a plurality of light emitting portions 82 arranged at predetermined intervals in the main scanning direction. In the first embodiment, the light emitting unit 82 is an LED. Such a light source unit 62 is provided so as to be movable in the sub-scanning direction (in this embodiment, the left-right direction of the image reading apparatus 10) that is orthogonal to the main scanning direction. Light is irradiated, and the reflected light is reflected by the reflection mirror 72 and guided to the mirror unit 64. In the first embodiment, a side-emitting LED is used as the light-emitting unit 82, but the light-emitting unit 82 may be a top-emitting LED. In addition, the light source 70 is disposed only on one side in the sub-scanning direction with reference to the position where the document is irradiated, but the light source 70 may be disposed on both sides in the sub-scanning direction.

  The mirror unit 64 includes a plurality of reflection mirrors 74, further reflects the reflected light from the reflection mirror 72 of the light source unit 62 and guides it to the sensor unit 66. This mirror unit 64 is also provided so as to be movable in the sub-scanning direction.

  The sensor unit 66 includes an imaging lens 76 and a plurality of imaging elements 78 arranged in a line along the main scanning direction. The imaging lens 76 condenses the reflected light from the mirror unit 64 and forms an image of the document on the image sensor 78. In this embodiment, the image sensor 78 is a CCD (Charge Coupled Device) image sensor, and photoelectrically converts the reflected light for each pixel and outputs it as an image signal. That is, the image sensor 78 converts the received light into an electrical signal, and outputs an electrical signal (analog image data) having an output level corresponding to the amount of received light. The electric signal output from the image sensor 78 is input to an image processing unit 112 (see FIG. 4) described later.

  When reading an image of a document placed on the document placement tray 54, the light source unit 62 is disposed at a position facing the image reading position 56, and the image reading unit 60 receives a document conveyed by the ADF 24. When passing through the image reading position 56, the image on the surface of the original is read. Further, when reading an image of a document placed on the document placement table 50, the image reading unit 60 moves the light source unit 62 and the mirror unit 64 below the document placement table 50 in the sub-scanning direction. The image on the surface of the original is read.

  FIG. 4 is a block diagram illustrating an example of an electrical configuration of the image forming apparatus 100. As illustrated in FIG. 4, the image forming apparatus 100 includes a CPU 102, and the CPU 102 is connected to a RAM 106, a ROM 108, an HDD 110, an image processing unit 112, and the like via an internal bus 104. The CPU 102, RAM 106, ROM 108, HDD 110, and image processing unit 112 constitute the control unit 14 described above. The control unit 14 is connected to the above-described image reading unit 60, the image forming unit 16, the operation unit 18, and the like via the internal bus 104.

  The CPU 102 governs overall control of the image forming apparatus 100. The RAM 106 is used as a working area and a buffer area for the CPU 102. The ROM 108 stores default values for the activation program of the image forming apparatus 100 and various information. The HDD 110 is a main storage device of the image forming apparatus 100 and stores image data (scanned image data) read by the image reading unit 60, image data transmitted from an external computer, and the like.

  The image processing unit 112 performs various types of image processing such as A / D conversion processing and shading correction on the scanned image data input from the image reading unit 60. In addition, the image processing unit 112 generates a luminance distribution that is a luminance value distribution of each pixel included in the scan image data, and extracts the coordinates of the luminance peak, or extracts the luminance value of a predetermined coordinate. .

  In addition, the image reading unit 60 includes the light source 70 and the plurality of imaging elements 78 as described above. When causing the image sensor 78 of the image reading unit 60 to read an image, the CPU 102 controls turning on and off of each light emitting unit 82 of the light source 70 via a lighting control circuit (not shown), and turning on the light source 70. Control the amount of light.

  In such an image reading apparatus 10, it is possible to read an image of a three-dimensional glossy object such as a metal product by placing it on the document table 50. However, when the object whose image is to be read is a glossy object, striped white stripes may occur in the scanned image (the image read by the image sensor 78 of the image reading unit 60) as shown in FIG. This is considered to be because, when an array type LED light source is used as the light source 70 as in this embodiment, the amount of light from the light source 70 becomes large at each position in the main scanning direction where the light emitting unit 82 is disposed. It is done. This is not a problem for normal documents, but for glossy objects with a large amount of reflected light, the central portion of each position in the main scanning direction where the light emitting section 82 is arranged becomes a bright spot, and white stripes extend in the sub-scanning direction. Appear in the scanned image.

  Therefore, in the first embodiment, in consideration of the fact that the arrangement mode such as the number and interval of the light emitting units 82 is unique in the image reading apparatus 10, the line data corresponding to the arrangement of the light emitting units 82 is preliminarily stored in the ROM 108. For example, it is determined whether or not white stripes are generated in the scanned image using the stripe data. When it is determined that white spots are generated in the scanned image, the light amount of the light source 70 is made smaller than the reference light amount, and the object is rescanned (image data is reacquired). By reducing the light amount of the light source 70, the amount of reflected light from the object is also reduced, so that the occurrence of white spots is suppressed. This will be specifically described below.

  In this embodiment, the streak data is data indicating the size of the bright spot interval of the light source 70 based on the arrangement of the light emitting units 82 (that is, the striped white streak interval expected to occur in the apparatus). . Then, when striped white streaks are detected in the scanned image when the scanning process is executed, for example, the scanned image has a plurality of luminance peaks that appear at predetermined intervals in the main scanning direction. When it is detected that a predetermined value or more continues in the sub-scanning direction, the interval between white stripes appearing in the scanned image is compared with the bright spot interval stored as the stripe data. As a result, when these intervals coincide (that is, when the degree of coincidence is equal to or greater than a predetermined threshold), striped white stripes are generated in the scanned image due to the object being a glossy object. Judge that In addition, when a striped white streak is not detected in the scanned image, or when a striped white streak is detected and the interval is different from the interval of the streak data, no white streak is generated in the scanned image. Judge.

  However, the stripe data may be data indicating the coordinates of the predicted generation position of the striped white stripe set based on the arrangement of the light emitting units 82. In this case, when the brightness of the occurrence predicted position of the white spot and the brightness between the occurrence predicted positions are extracted from the scan image, and the difference between these brightness is larger than the threshold value, the white spot is generated in the scan image. It is good to judge.

  The stripe data may be data indicating an image pattern of white stripes set based on the arrangement of the light emitting units 82. In this case, it is preferable to use a pattern matching method to determine that a blank line is generated in the scan image when an image that matches the image pattern that is the line data is extracted from the scan image.

  When it is determined as a result of the streak determination process for determining whether or not white stripes are generated as described above, striped white stripes resulting from the object being a glossy object are generated in the scanned image Then, the light quantity of the light source 70 is lowered and the rescan process is executed. At this time, the light amount of the light source 70 is preferably decreased step by step by a predetermined value, and it is preferable to repeat the rescanning process until it is determined as a result of the line determination process that no white stripes have occurred. This is because the light amount of the light source 70 can be automatically adjusted to an appropriate light amount according to the object, and the occurrence of white stripes can be prevented or suppressed while maintaining the image quality of the scanned image. . However, it is preferable that a minimum reference value (minimum light amount) of the light amount is set in advance, and the rescan process is not repeated when the light amount of the light source 70 reaches the minimum reference value. This is because if the light amount of the light source 70 is too low, the image of the object cannot be read properly. Note that the light amount of the light source 70 does not necessarily have to be decreased stepwise, and when it is determined that white spots are generated in the scanned image, the light amount of the light source 70 can be decreased to the minimum reference value at a time.

  The above-described operations of the image forming apparatus 100 and the image reading apparatus 10 are realized by the CPU 102 executing a control program that is read and stored in the RAM 106. Specific processing will be described later with reference to a flowchart.

  FIG. 5 is an illustrative view showing one example of a memory map 200 of the RAM 106 shown in FIG. As shown in FIG. 5, the RAM 106 includes a program storage area 202 and a data storage area 204. The program storage area 202 stores a control program for controlling the image forming apparatus 100. The control programs include an operation detection program 202a, an image reading program 202b, a white stripe determination program 202c, a light amount control program 202d, an image formation program 202e, and the like.

  The operation detection program 202a is a program for detecting an operation input from the operation unit 18 operated by the user. For example, the operation input is operation data input in response to operation of various operation buttons such as a copy button, and touch coordinate data input in response to operation (touch) of the touch panel.

  The image reading program 202b controls the operation of the image reading unit 60 to read the image of the object placed on the document table 50 or the object conveyed from the ADF 58 and generate image data (scanned image data). It is a program to do.

  The blank stripe determination program 202c uses stripe data set in advance, and striped blank stripes are generated in the scanned image read by the image reading unit 60 due to the object being a glossy object. It is a program for judging whether or not.

  The light amount control program 202d is a program for changing the light amount of the light source 70 when striped white stripes are generated in the scanned image.

  The image forming program 202e is a program for controlling the operation of the image forming unit 16 and printing an image corresponding to the image data on recording paper (paper).

  The data storage area 204 is provided with an operation input data buffer 204a and an image data buffer 204b. The data storage area 204 stores the muscle data 204c and the light amount adjustment data 204d.

  The operation input data buffer 204 a is a buffer for temporarily storing operation inputs from the operation unit 18. The image data buffer 204b is a buffer for temporarily storing image data read by the image reading unit 60, image data transmitted from an external computer, and the like.

  The streak data 204c is data for determining whether or not white stripes are generated, which is set in advance based on the arrangement of the light emitting units 82 of the light source 70, and is a striped white stripe that is predicted to be generated in the apparatus. This is data indicating the interval or coordinates of the. The light amount adjustment data 204d is data indicating a light amount value corresponding to a preset number of rescans and a minimum reference value of the light amount.

  Although illustration is omitted, the program storage area 202 also stores other programs for executing the functions of the image forming apparatus 100 as appropriate. The data storage area 204 stores other data necessary for execution of the control program, and is provided with a timer (counter) and a flag necessary for execution of the control program.

  FIG. 6 is a flowchart illustrating an example of scan processing of the image forming apparatus 100 (image reading apparatus 10). For example, when the object is placed on the document placing table 50 by the user and the copy button is selected, the CPU 102 executes a scanning process and acquires a scanned image of the object in step S1. That is, the CPU 102 causes the image sensor 78 to read an image of the object by irradiating the light source 70 with the reference light amount while moving the light source unit 62 and the mirror unit 64 in the sub-scanning direction.

  In the next step S3, it is determined whether or not streak white stripes are generated in the scanned image acquired in step S1 using the line data. For example, when the CPU 102 detects a striped white streak in the scan image, the CPU 102 reads the bright spot interval stored as the streak data and compares it with the white streak interval appearing in the scan image. When these intervals coincide with each other, it is determined that striped white stripes resulting from the object being a glossy object are generated in the scanned image.

  If “NO” in the step S3, that is, if it is determined that the streak-like white streak is not generated in the scanned image, the scanning process is ended as it is. Then, an image forming process is performed in which an image corresponding to the acquired scanned image (or the immediately preceding rescanned image after rescanning) is printed on a recording sheet or the like. On the other hand, if “YES” in the step S3, that is, if it is determined that a streak of white stripes is generated in the scanned image, the process proceeds to a step S5.

  In step S5, it is determined whether or not the currently set light amount of the light source 70 is larger than the minimum reference value. That is, when the light amount of the light source 70 is decreased stepwise, it is determined whether or not the set light amount has reached the minimum reference value.

  If “NO” in the step S5, that is, if the light amount of the light source 70 has reached the minimum reference value, the scanning process is ended as it is. Then, an image forming process for printing an image corresponding to the immediately preceding rescanned image on a recording sheet or the like is performed. On the other hand, if “YES” in the step S5, that is, if the light amount of the light source 70 has not reached the minimum reference value, the process proceeds to a step S7.

  In step S7, the light amount of the light source 70 is set to a value lower than the reference light amount (currently the set light amount in the case of the second and subsequent rescans) by returning to step S1, and scan processing is executed again. To do. That is, the CPU 102 performs rescanning processing that causes the image sensor 78 to read the image of the target object again by irradiating the light source 70 with light whose light amount is reduced when white spots are generated in the scanned image. To do. If it is determined that white stripes have occurred in the scanned image even after the rescan process is executed, the amount of light from the light source 70 is determined until it is determined that white stripes have not occurred. Until the minimum reference value set in advance is reached, the light amount of the light source 70 is decreased stepwise and the rescan process is repeated.

  As described above, according to the first embodiment, it is determined whether or not white stripes are generated in the scan image using the stripe data set in advance based on the arrangement of the light emitting units 82 of the light source 70. Since it determines, the presence or absence of the striped white stripe resulting from a target object being a glossy object can be determined appropriately. If striped white stripes are generated, the amount of light from the light source 70 is reduced and the rescan process is performed. Therefore, the occurrence of striped white stripes is generated without increasing the operation burden on the user. Can be prevented or suppressed appropriately.

  Further, according to the first embodiment, the light amount of the light source 70 is changed until it is determined that no white stripes are generated in the scanned image or until the light amount of the light source 70 reaches a preset minimum reference value. Since the rescan process is repeated stepwise, the light amount of the light source 70 can be automatically adjusted to an appropriate light amount according to the object. Therefore, it is possible to appropriately prevent or suppress the occurrence of white spots while maintaining the image quality of the scanned image.

[Second Embodiment]
Next, an image reading apparatus 10 according to the second embodiment of the present invention will be described with reference to FIGS. The image reading apparatus 10 of the second embodiment displays a message on the screen of the display unit 90 when striped white stripes are not eliminated even when the light amount of the light source 70 reaches a preset minimum reference value. Other than this, the second embodiment is the same as the first embodiment, and therefore, the contents different from the first embodiment will be described, and redundant description will be omitted.

  As shown in FIG. 7, in the second embodiment, the process of step S9 is executed in addition to the processes of steps S1 to S7 shown in the flowchart of FIG. In the second embodiment, if “NO” in step S5, that is, if striped white stripes occur in the scanned image even if the light amount of the light source 70 is reduced to the minimum reference value, the CPU 102 performs step Proceed to S9. In step S <b> 9, a message prompting to change the orientation of the object as illustrated in FIG. 8 is displayed on the screen of the display unit 90. This is because by changing the direction of the object, the light reflection direction may change and the white stripes may be eliminated. When the process of step S9 is completed, the scanning process is terminated as it is, and the user waits for the object to be placed on the document table 50 and the copy button to be selected again.

  According to the second embodiment, even when the striped white stripes are not eliminated by the light amount control of the light source 70, the occurrence of white stripes may be prevented or suppressed in some cases.

  In the example shown in FIG. 8, a message prompting the user to change the orientation of the object is displayed on the screen of the display unit 90. Instead of displaying this message or together with this message, for example, “scanned image” As you can see, there are streaks due to the reflected light of the light source. The light intensity was adjusted but could not be resolved. " A message for notifying (warning) that streaks due to the above cannot be eliminated may be displayed, and then the scanned image may be output or saved. Further, when outputting or saving a scan image, the user may be inquired in advance about whether to output or save the scan image. Furthermore, instead of displaying these messages, or together with displaying the messages, sounds or sounds corresponding to the messages may be output from a speaker.

[Third embodiment]
Next, with reference to FIG. 9, an image reading apparatus 10 according to a third embodiment of the present invention will be described. The image reading apparatus 10 according to the third embodiment reduces the light amount of the light source 70 only in a predetermined area including an image area where white stripes are generated during rescanning. Other than this, the second embodiment is the same as the first embodiment, and therefore, the contents different from the first embodiment will be described, and redundant description will be omitted.

  As shown in FIG. 9, in this third embodiment, when it is determined that striped white stripes are generated in the scanned image, white stripes are generated instead of reducing the light amount of the entire scanned image. An image area is identified, and control is performed so that only a predetermined area including the image area is rescanned with the light amount of the light source 70 reduced. For example, in the main scanning direction, it is preferable that only the light emitting unit 82 in the section corresponding to the image area where the white stripe is generated is controlled so as to reduce the light amount. Further, with respect to the sub-scanning direction, when the light source unit 62 moves, it is preferable to control so that the light amount of the light source 70 is reduced only when it passes through a section corresponding to an image area where white stripes are generated. As a result, a normal scan image can be obtained for an image region in which the light amount of the light source 70 is not reduced.

  However, it is not always necessary to limit the image area in which the amount of light is reduced to a predetermined area in both the main scanning direction and the sub-scanning direction, and it can also be performed in either the main scanning direction or the sub-scanning direction.

  In the example shown in FIG. 9, the light amount is reduced by a rectangular section including an image area where white stripes occur, but the area including the image area where white stripes appear (circular in FIG. 9). ) To reduce the amount of light. However, the rectangle is defined by a width in the vertical direction (main scanning direction) and a width in the horizontal direction (sub-scanning direction).

  According to the third embodiment, when the image of the object is rescanned, the light amount of the light source 70 is reduced only in a predetermined area including an image area where white stripes are generated, so that the image quality of the scanned image is maintained. On the other hand, it is possible to appropriately prevent or suppress the occurrence of white stripes.

  In the above-described embodiment, it is determined whether or not white spots are generated in the scanned image as shown in FIG. 6 or 7 regardless of the object placed on the document table 50. However, the present invention is not limited to this. The scan process as shown in FIG. 6 or 7 may be executed only when the glossy object scan mode is selected (set) by the user. In such an embodiment (fourth embodiment), the user needs to select a scan mode, but it is not necessary to set the amount of light according to the glossy object, so the operation burden on the user is reduced. In addition, when the glossy object scan mode is selected by the user, a process of uniformly reducing the light amount of the light source 70 can be considered. However, when reading an image of a glossy object, striped white stripes do not necessarily occur in the scanned image. Therefore, even when this is not necessary, the light amount of the light source 70 is reduced and the image quality of the scanned image is improved. It will decline. On the other hand, in the case of the fourth embodiment, even when the glossy object scan mode is selected, the light amount of the light source 70 is reduced and re-scanning is performed only when white spots occur at the reference light amount. Necessary deterioration of image quality is suppressed.

  Further, in the above-described embodiment, when it is determined that white stripes are generated in the scan image, the light amount of the light source 70 is automatically reduced to perform the rescan process. However, the present invention is not limited to this. For example, before performing the rescan process, a preview image based on the scanned image is displayed on the display unit 90 included in the operation unit 18 and a touch key that allows the user to select whether or not to rescan is displayed. Like that. Then, when the user instructs to rescan according to the display, the light amount of the light source 70 may be reduced to perform the rescan process.

  In addition, after performing the rescan process and before performing the image forming process, a preview image based on the first acquired scan image and a preview image based on the rescanned rescan image are displayed on the display unit 90, The user may be able to select which scan image is used to perform the image forming process. Of course, when the rescan process is performed a plurality of times, it is possible to select from all the acquired scan images.

  In the above-described embodiment, the CCD image reading unit 60 is used. However, the image reading unit 60 may be a CIS (Contact Image Sensor) type.

  Further, in the above-described embodiment, it is determined whether or not white stripes are generated in the actual scan image, but it is not necessary to be limited to this. In another example, only the process of determining whether or not white stripes have occurred in an image obtained by reading at a resolution lower than the set resolution of the actual scanned image (scanning process) or reading only in black and white is first performed. May be done.

DESCRIPTION OF SYMBOLS 10 ... Image reading apparatus 12 ... Apparatus main body of image forming apparatus 14 ... Control part 16 ... Image forming part 18 ... Operation part 60 ... Image reading part 70 ... Light source 78 ... Imaging element 82 ... Light emission part 90 ... Display part 100 ... Image formation apparatus

Claims (8)

A light source having a plurality of light emitting units arranged at predetermined intervals in the main scanning direction, and irradiating an object;
An image sensor that receives reflected light from the object of light emitted from the light source and reads an image of the object;
A muscle data storage unit for storing muscle data set in advance based on the arrangement of the light emitting units;
Using the muscle data stored in the muscle data storage unit, a muscle determination unit that determines whether or not white stripes are generated in an image read by the imaging device, and white stripes are generated by the muscle determination unit An image reading apparatus comprising: a control unit that performs a rescan process that causes the image sensor to read an image of the object again by irradiating light with a light amount reduced from the light source when it is determined that the light source is lighted.   The control unit gradually reduces the light amount of the light source until it is determined by the streak determination unit that no white stripes have occurred or until the light amount of the light source reaches a preset minimum reference value. The image reading apparatus according to claim 1, wherein the rescan process is repeated.   Even if the control unit executes the rescan process in a state where the light amount of the light source is lowered to a preset minimum reference value, the streak determination unit determines that white stripes are generated in the rescanned image. The image reading apparatus according to claim 1, wherein when determining, a message prompting to change the direction of the object is displayed on a display unit.   Even if the control unit executes the rescan process in a state where the light amount of the light source is lowered to a preset minimum reference value, the streak determination unit determines that white stripes are generated in the rescanned image. The image reading apparatus according to claim 1, wherein when the determination is made, the fact that the outline stripe is generated is notified.   5. The control unit according to claim 1, wherein when the rescan process is performed, the light amount of the light source is decreased only in a predetermined region including an image region where the white stripe is generated. Image reading device.   An image forming apparatus comprising the image reading apparatus according to claim 1. A plurality of light emitting units arranged at predetermined intervals in the main scanning direction, a light source that irradiates the object, and reflected light from the object that is irradiated from the light source, and receives an image of the object A control program executed by a processor of an image reading device including an image sensor to be read and a muscle data storage unit that stores muscle data set in advance based on the arrangement of the light emitting unit,
A processor of the image reading device;
Using the muscle data stored in the muscle data storage unit, a muscle determination unit that determines whether or not white stripes are generated in an image read by the imaging device, and white stripes are generated by the muscle determination unit A control program that, when it is determined that the light source has been determined, causes the light source to emit light with a reduced amount of light, and causes the image sensor to re-read an image of the object, and to function as a control unit that executes a rescan process. A plurality of light emitting units arranged at predetermined intervals in the main scanning direction, a light source that irradiates the object, and reflected light from the object that is irradiated from the light source, and receives an image of the object A control method for an image reading apparatus comprising: an image sensor to be read; and a streak data storage unit that stores streak data set in advance based on the arrangement of the light emitting unit,
The processor of the image reading device includes:
Using the stripe data stored in the stripe data storage unit, it is determined whether or not white stripes are generated in the image read by the image sensor, and white stripes are generated in the image read by the image sensor. A control method of executing re-scanning processing of causing the imaging device to read an image of the object again by irradiating light having a reduced light amount from the light source.