JP2012034168A - Image reader and image formation device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain data obtained by properly reading respective images even when various images such as characters and photographs are mixed in a document, by an image reader for generating image data by reading the document.SOLUTION: The image reader comprises: an LED lamp 6 for irradiating the document with light; an image sensor 15 which converts light reflected by the document to an electric signal; a first image processing unit 9 which generates image data using the electric signal obtained from the image sensor 15; and a lighting control unit 93 which controls the light to irradiate the document therewith by the LED lamp 6. When the first image processing unit 9 generates the image data of a sheet of a document, the lighting control unit 93 controls the light of the LED lamp 6 to irradiate at least a part of the document respectively with a plurality of different patterns of light.

Description

  The present invention relates to an image reading apparatus that reads a document. The present invention also relates to an image forming apparatus provided with the image reading apparatus.

  For example, there is an image reading apparatus that reads a document (reading object, for example, paper) such as a scanner. In general, the image reading apparatus includes a light source such as a lamp that irradiates light on a document, an image sensor that receives reflected light from the document and performs photoelectric conversion, and the like. The image reading apparatus may be mounted on an image forming apparatus such as a copying machine, a multifunction machine, or a FAX apparatus.

  For example, Patent Document 1 discloses a color copying machine that divides image data obtained by an image reading device reading a document into a plurality of sections and prints output images obtained by performing different color correction processes on the sections. Is described. According to this color copying machine, a user who has confirmed a printed output image can easily select a color correction process to be selected by comparing the sections in the output image. Then, it is possible to prevent toner from being wasted by trial printing a plurality of output images subjected to different color correction processing (Patent Document 1: Claims 1, 2, Paragraph [0020], [0021] and [0033] etc.).

Japanese Patent Laid-Open No. 5-110839

  According to the color copying machine described in Patent Document 1, it is possible for a user to easily select a color correction process to be selected based on a printed output image, and to prevent toner from being wasted. It becomes. However, the color correction process that can be selected by the user is a color correction process for printing an image having a good color balance as a whole, and is a color correction process that is uniformly applied to the entire image data. Therefore, even if the output image is printed after being subjected to the color correction process selected by the user, it may not be partially in the state desired by the user.

  In particular, a document read by the image reading apparatus may include not only a single type of image (for example, an image showing a character or an image showing a photograph) but also a mixture of a plurality of types of images. . When the image reading apparatus reads such a document in which a plurality of types of images are mixed, depending on the suitability of the reading conditions (for example, the state of light that the light source irradiates the document) and the type of image in the document, Partially degraded image data is generated. Therefore, even if such image data is corrected by performing the uniform processing described in Patent Document 1, it is difficult to improve the partial deterioration.

  Further, in a post-process (a process performed on image data obtained by reading a document) as described in Patent Document 1, deterioration due to the process (for example, edge enhancement to make the image data clear) (Degradation of gradation in the case of performing the above process) cannot be ignored. For this reason, it is difficult to obtain image data in a state desired by the user in the subsequent processing.

  In view of the above-described problems of the prior art, the present invention is an image reading apparatus that reads an original and generates image data, and appropriately reads each image even when various images such as characters and photographs are mixed in the original. The problem is to obtain the data.

  In order to achieve the above object, an image reading apparatus according to claim 1 includes: a lighting unit that irradiates light to a document; an image sensor that converts light reflected by the document into an electrical signal; and the image sensor. An image data generation unit that generates image data using the obtained electrical signal; and a lighting control unit that controls the light that the lighting unit irradiates the document. When generating the image data of the document, the lighting control unit controls the lighting unit so that at least a part of the document is irradiated with a plurality of different patterns of light.

  According to this configuration, even if different types of images are mixed in the document, each data including an electrical signal read using light suitable for each image in the document can be obtained.

  According to a second aspect of the present invention, in the first aspect of the present invention, each of the electrical signals obtained from the image sensor is converted into the image by irradiating the original with a plurality of different patterns of light. The data generation unit selectively combines to generate the image data of the document.

  According to this configuration, image data is generated using an electrical signal obtained by reading under an appropriate reading condition. Therefore, partial deterioration of the image data can be suppressed.

  According to a third aspect of the present invention, in the second aspect of the present invention, the light of the first pattern irradiated at a first intensity for a first time on the original and a second intensity smaller than the first intensity. The lighting control unit controls the lighting unit so that the second pattern light irradiated for a second time longer than the first time is emitted, and the first pattern is applied to the document. A first electric signal obtained from the image sensor by irradiating the light and a second electric signal obtained from the image sensor by irradiating the original with the light of the second pattern. The image data generation unit selectively combines to generate image data of the document.

  According to this configuration, the first electric signal having a sharp image such as a character whose image density changes sharply and the second electric signal having a smooth image such as a photograph in which the image density hardly changes are selectively selected. Can be obtained.

  According to a fourth aspect of the present invention, in the invention of the third aspect, when the image data generating unit generates image data of one original, the lighting unit is in a predetermined direction with respect to the original. The first pattern of light and the second pattern are scanned for each unit area formed by dividing the original along the predetermined direction in the scanning. The lighting control unit controls the lighting unit so that each of the lights is irradiated.

  According to this configuration, the first electric signal and the second electric signal can be obtained by one scan. Therefore, smooth reading can be performed.

  According to a fifth aspect of the invention, in the third aspect of the invention, when the image data generating unit generates image data of one original, the lighting unit is directed in a predetermined direction with respect to the original. The light is sequentially irradiated twice, and in the first scanning, one of the first pattern light and the second pattern light is irradiated to the original, and the second scanning. Therefore, the lighting control unit controls the lighting unit so that the other of the first pattern light and the second pattern light is irradiated to the original.

  According to this configuration, each of the first electric signal and the second electric signal can be obtained by two scans.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the image data generation unit is configured to perform the second scanning operation based on an electrical signal obtained from the image sensor during the first scanning operation. The lighting unit determines the timing for irradiating light, and the lighting control unit controls the lighting unit so that light is emitted to the document at the second timing of the scanning. .

  According to this configuration, the number of times the lighting unit is lit in the second scan can be made equal to or less than the first scan. Therefore, power consumption can be reduced.

  According to a seventh aspect of the present invention, in the sixth aspect of the invention, the first pattern of light is irradiated to the original at the first scanning, and the original is irradiated at the second scanning. The lighting control unit controls the lighting unit so that the second pattern of light is irradiated, and the image data generation unit has a predetermined region of the first electric signal obtained in the first scanning. The amount of variation is detected for each time, and light is emitted to the document at the second scanning time at the timing of reading a region in the document corresponding to a region where the amount of variation of the first electrical signal is relatively small. Thus, the lighting control unit controls the lighting unit.

  According to this configuration, the first electric signal obtained by irradiating the first pattern of light in the first scan can be abruptly fluctuated. Therefore, when the fluctuation amount of the first electric signal is confirmed, an area obtained by reading an image such as a character whose image density fluctuates sharply (an area where the fluctuation quantity is relatively large) and the image density hardly fluctuate sharply. An area obtained by reading an image such as a photograph (an area with a relatively small fluctuation amount) can be accurately separated. Therefore, power consumption can be effectively reduced.

  According to an eighth aspect of the present invention, in the fifth to seventh aspects of the invention, the first time of the scanning, the direction in which light is sequentially applied to the document, and the second time of the scanning, The direction in which light is sequentially applied to the document is opposite to the direction.

  According to this configuration, reading can be performed smoothly.

  The invention according to claim 9 is the invention according to claims 3 to 8, wherein the image data generation unit has a variation amount for each predetermined region with respect to at least one of the first electric signal and the second electric signal. And the image data generation unit selects and combines the first electrical signal in a region where the variation amount is relatively large, and selects the second electrical signal in a region where the variation amount is relatively small. The document image data is generated.

  According to this configuration, an image obtained by reading an image such as a character whose image density fluctuates sharply (an area where the fluctuation amount is relatively large) and an image such as a photograph where the image density hardly fluctuates sharply are read. It is possible to separate the obtained region (region where the variation amount is relatively small). Then, it is possible to obtain image data in which an image such as a character whose image density changes sharply is clear and an image such as a photograph where the image density hardly changes sharply is smooth.

  According to a tenth aspect of the present invention, in the ninth aspect of the invention, the image data generation unit detects a variation amount for each predetermined region of the first electric signal, and the image data generation unit includes the first data signal. The first electric signal is selected in a region where the fluctuation amount of the electric signal is relatively large, and the second electric signal is selected and combined in a region where the fluctuation amount of the first electric signal is relatively small. Image data was generated.

  According to this configuration, by confirming the amount of fluctuation of the first electrical signal that can vary steeply, an area obtained by reading an image such as a character whose image density varies abruptly (an area with a relatively large amount of fluctuation) ) And an area obtained by reading an image such as a photograph in which the image density is less likely to fluctuate sharply (an area where the fluctuation amount is relatively small) can be accurately separated.

  According to an eleventh aspect of the present invention, in the first to tenth aspects of the invention, the driving unit that moves the lighting unit with respect to a predetermined direction of the original and / or the original with respect to the lighting unit. Is further provided with a document conveying section that moves the lighting section in a predetermined direction, and the driving section moves the lighting section, and / or the document conveying section moves the document, so that the lighting section moves relative to the document. Scanning with light irradiation in order along a predetermined direction was performed.

  According to this configuration, scanning can be easily performed.

  An image forming apparatus according to a twelfth aspect includes the image reading apparatus according to any one of the first to eleventh aspects.

  According to this configuration, even if images of different types are mixed in an original, the image forming apparatus can obtain each data including an electrical signal read using light suitable for each image in the original Can be provided.

  According to the present invention, when generating image data of one original, a plurality of different patterns of light are irradiated to the original. Therefore, even if different types of images are mixed in the original, it is possible to obtain each data including an electrical signal read using light suitable for each image in the original.

1 is a schematic cross-sectional view showing a schematic configuration of a copying machine according to a first embodiment. 1 is a schematic cross-sectional view illustrating an example of an image reading apparatus according to a first embodiment. 1 is a block diagram illustrating an example of a configuration of a copier according to a first embodiment. 1 is a block diagram illustrating an example of a configuration of an image reading apparatus according to a first embodiment. It is explanatory drawing which shows an example of the lighting pattern of LED which concerns on 1st Embodiment. 6 is a timing chart illustrating an example of an operation of the image reading apparatus according to the first embodiment. It is a conceptual diagram which shows an example of the production | generation method of the image data by the image reading apparatus which concerns on 1st Embodiment. It is a conceptual diagram which shows an example of the production | generation method of the image data by the image reading apparatus which concerns on 2nd Embodiment. 12 is a timing chart illustrating an example of an operation of the image reading apparatus according to the third embodiment. It is a conceptual diagram which shows an example of the production | generation method of the image data by the image reading apparatus which concerns on 3rd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. However, each element such as configuration and arrangement described in this embodiment does not limit the scope of the invention and is merely an illustrative example.

(Outline of image forming apparatus)
First, an outline of an electrophotographic copying machine 200 (corresponding to an image forming apparatus) including the image reading apparatus 100 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a front sectional view schematically showing a configuration of a copying machine 200 according to the first embodiment of the present invention.

  As shown in FIG. 1, a copying machine 200 according to the present embodiment has an image reading apparatus 100 disposed above. The image reading apparatus 100 includes an image reading unit 1 that irradiates light on the upper surface of the conveyance reading contact glass 11 or the placement reading contact glass 12 and generates image data by the image sensor 15 based on the reflected light. 1 includes a document conveyance unit 2 that opens and closes in the vertical direction with respect to the image reading unit 1 by a rotating shaft 2a (see FIG. 3) and conveys a document toward the conveyance reading contact glass 11. Details of the image reading apparatus 100 will be described later.

  Further, as indicated by a broken line in FIG. 1, an operation panel 3 is provided on the front side of the image reading unit 1. The operation panel 3 includes a liquid crystal display unit 30 that displays keys for setting the copying machine 200 and receives user inputs. Further, the liquid crystal display unit 30 can display the status of the copying machine 200 such as an error such as a jam or out of paper. In addition, a numeric keypad 31 for inputting numbers such as the number of copies, a start key 32 for instructing copy execution, and the like are arranged on the operation panel 3.

  As shown in FIG. 1, the copying machine 200 according to this embodiment includes a sheet feeding unit 4A, a conveyance path 4B, an image forming unit 5A, an intermediate transfer unit 5B, a fixing unit 5C, and the like inside the main body. Each of the plurality of paper feeding units 4A in the copying machine 200 main body has a size (for example, A type, B type paper such as A4 and B4), various types of paper (for example, copy paper, recycled paper, cardboard, OHP sheet). Etc.). Each paper feed unit 4A includes a paper feed roller 41 that is driven to rotate, and feeds paper one by one to the transport path 4B during printing.

  The transport path 4B is a path for transporting paper in the apparatus. Then, on the conveyance path 4B, a guide plate for guiding the sheet, a pair of conveyance rollers 42 that are rotationally driven during conveyance of the sheet (in FIG. 1, a total of three of 42A, 42B, and 42C from the top) are conveyed. A registration roller pair 43 and the like are provided that waits before the image forming unit 5A and feeds the sheet in accordance with the transfer timing of the formed toner image. In addition, a pair of discharge rollers 45 for discharging the sheet after completion of fixing to the discharge tray 44 is also provided.

  The image forming unit 5A includes a plurality of image forming units 50 (50Bk for black, 50Y for yellow, 50C for cyan, 50M for magenta) and an exposure device 51. The exposure device 51 outputs laser light while turning it on and off based on the image data read by the image reading unit 1, and scans and exposes each photosensitive drum. The image forming unit 50 includes a photosensitive drum that is rotatably supported, and a charging device, a developing device, a cleaning device, and the like disposed around the photosensitive drum. Then, a toner image is formed on the peripheral surface of the photosensitive drum by each image forming unit 50 and the exposure device 51.

  The intermediate transfer unit 5B receives the primary transfer of the toner image from each image forming unit 50 and performs the secondary transfer on the sheet. The intermediate transfer unit 5B includes primary transfer rollers 52Bk to 52M, an intermediate transfer belt 53, a driving roller 54, a plurality of driven rollers 55, a secondary transfer roller 56, a belt cleaning device 57, and the like. Each primary transfer roller 52 </ b> Bk to 52 </ b> M sandwiches a corresponding photosensitive drum and an endless intermediate transfer belt 53. A transfer voltage is applied to each of the primary transfer rollers 52 </ b> Bk to 52 </ b> M, and the toner image is transferred to the intermediate transfer belt 53.

  The intermediate transfer belt 53 is stretched around a driving roller 54 and the like, and rotates around the driving roller 54 connected to a driving mechanism (not shown) such as a motor. The intermediate transfer belt 53 and the drive roller 54 sandwich the intermediate transfer belt 53 with the secondary transfer roller 56. The toner images (black, yellow, cyan, and magenta colors) formed by each image forming unit 50 are sequentially transferred to the intermediate transfer belt 53 in a superimposed manner without deviation, and then applied with a predetermined voltage. The image is transferred onto the sheet by the secondary transfer roller 56.

  The fixing unit 5C fixes the toner image transferred to the paper. The fixing unit 5C mainly includes a heating roller 58 containing a heating element and a pressure roller 59 in pressure contact therewith. When the sheet passes through the nip between the heating roller 58 and the pressure roller 59, the toner is melted and heated, and the toner image is fixed on the sheet. The sheet discharged from the fixing unit 5C is sent to the discharge tray 44.

(Configuration of Image Reading Apparatus 100)
Next, an example of the image reading apparatus 100 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view showing an example of the image reading apparatus 100 according to the first embodiment of the present invention. Although details will be described later, in the image reading apparatus 100 according to the present embodiment, since it is necessary to finely control the light applied to the document, it is possible to respond quickly such as an LED (Light Emitting Diode). It is preferable to apply a light source. In addition, although it is also possible to apply light sources other than LED, for the sake of concrete description, a case where an LED is applied as a light source will be exemplified below.

  First, the document conveying section 2 automatically and continuously conveys the document to be read one by one to a reading position (a conveyance reading contact glass 11 described later). The document transport unit 2 includes, in order from the upstream side in the document transport direction, a document tray 21, a document supply roller 22, a document transport path 23, a plurality of document transport roller pairs 24, a document discharge roller pair 25, a document discharge tray 26, and the like. The document conveying unit 2 is attached to the image reading unit 1 so as to be able to be opened and closed in the vertical direction with the back side of the sheet of FIG. 2 as a fulcrum, and functions as a cover for pressing each contact glass of the image reading unit 1 from above.

  A plurality of documents to be read are placed on the document tray 21. Then, the document supply roller 22 contacts the uppermost document among the documents placed on the document tray 21. For example, when an input for reading a document, such as pressing the start key 32, is input to the copying machine 200, the document supply roller 22 sends the document to the document transport path 23 one by one.

  The fed document is guided to a plurality of document transport roller pairs 24 and guides, and passes through the upper surface of the transport reading contact glass 11 provided on the upper surface of the image reading unit 1. During this passage, the image reading unit 1 performs reading. Then, the document that has been read is discharged from the document discharge roller pair 25 to the document discharge tray 26 (the document transport path is shown by a two-dot chain line). Each of the rotating bodies (the document supply roller 22, the document transport roller pair 24, and the document discharge roller pair 25) rotates with the document transport motor 27 (see FIG. 4) as a drive source.

  Next, the image reading unit 1 in the present embodiment will be described. As shown in FIGS. 1 and 2, the image reading unit 1 has a box-shaped housing. Then, on the left side of the upper surface of the image reading unit 1, a transparent plate-shaped conveyance reading contact glass 11 is arranged extending in a direction perpendicular to the paper surface of FIG. 2. Then, on the right side of the upper surface of the image reading unit 1, a transparent plate-like placement reading contact glass 12 is arranged extending in a direction perpendicular to the paper surface. The placement reading contact glass 12 is provided on the upper surface of the image reading unit 1. When reading a document such as a book one by one, the document is placed with the document transport unit 2 lifted and the reading surface facing downward.

  As shown in FIG. 2, a first moving frame 131, a second moving frame 132, a wire 133, a take-up drum 134, a lens 14, and an LED that irradiates light on the document are provided in the housing of the image reading unit 1. The provided LED lamp 6 (corresponding to a lighting unit), light irradiated on the document, and an image sensor 15 for reading the document for each line and generating an electrical signal are arranged. The image sensor 15 is constituted by, for example, a CCD (Charge Coupled Device) in which photoelectric conversion elements are arranged in a line shape, and reads the document line by line based on the reflected light of the document.

  The light emitted from the LED lamp 6 strikes the original on the conveyance reading contact glass 11, and the reflected light is reflected by the first mirror 161, the second mirror 162, and the third mirror 163 and guided to the lens 14. The lens 14 collects the reflected light and enters the image sensor 15. The image sensor 15 is a line sensor in which a plurality of light receiving elements are arranged in three lines of R, G, and B, for example. The image sensor 15 converts the reflected light into an analog electrical signal corresponding to the image density. The original is read line by line in the main scanning direction (perpendicular to the original conveying direction), and reading in line units is performed in order along the sub-scanning direction (original conveying direction), thereby making one original. Is read.

  The first moving frame 131 supports the LED lamp 6 that irradiates light upward and the first mirror 161 downward. The LED lamp 6 and each mirror have a shape extending in the direction perpendicular to the paper surface of FIG. The second moving frame 132 supports the second mirror 162 on the upper side and the third mirror 163 on the lower side. Further, the first moving frame 131 is disposed above the second moving frame 132. A plurality of wires 133 are attached to the first moving frame 131 and the second moving frame 132 (only one is shown in FIG. 2 for convenience). The other end of the wire 133 is connected to the take-up drum 134, and the take-up drum 13 rotates forward and backward by rotating the take-up motor 13M (corresponding to the drive unit, see FIG. 4). The second moving frame 132 moves freely in the horizontal direction.

  Here, an example of a specific document reading operation will be described. First, when reading a document transported by the document transport unit 2, the first moving frame 131 and the second moving frame 132 are moved to a lower position (reading position) of the transport reading contact glass 11 by the rotation of the winding motor 13M. Fixed. Then, the document transported by the document transport unit 2 passes over the area where the LED lamp 6 emits light, so that the document is sequentially irradiated with light along the sub-scanning direction (scanned). .

  On the other hand, when reading a document placed on the placement reading contact glass 12, the first moving frame 131 and the second moving frame 132 are horizontally moved from the home position to the right in FIG. 2 by the rotation of the winding motor 13M. By moving to, light is sequentially irradiated (scanned) along the sub-scanning direction to the placed document.

  The above scanning is continuously performed from one end to the other end of the document in the sub-scanning direction, thereby reading the entire document and obtaining an electrical signal of the document image. In this embodiment and the second embodiment described later, a single document is scanned twice. For example, when reading a document transported by the document transport unit 2, the document transported by the first scan described above is changed to the first scan by the reverse rotation of each rotating body (document transport motor 27) of the document transport unit 2. A second scanning may be performed by transporting in the reverse direction (switching back), or a mechanism for feeding the document transported by the first scanning again into at least a part of each rotating body of the document transport unit 2 May be provided in the document transport unit 2, and the mechanism may perform the second scanning by transporting the document in the same direction as the first scanning. Further, for example, when reading a document placed on the placement reading contact glass 12, the winding motor 13M is rotated in the direction opposite to the first scan and the LED is turned on after the first scan is completed. The lamp 6 may irradiate the original with light so that the second scan may be performed. After the first scan is completed, the winding motor 13M moves in the direction opposite to the first scan. By rotating, the first moving frame 131 and the second moving frame 132 may be moved to the home position, and the second scan may be performed in the same manner as the first scan.

(Hardware configuration of copying machine 200)
Next, an example of the hardware configuration of the copying machine 200 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing an example of the configuration of the copying machine 200 according to the first embodiment of the present invention.

  First, the main body control unit 8 of the copying machine 200 is provided with a CPU 81 as a central processing unit. In addition, a storage unit 82 composed of nonvolatile and volatile memories such as a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), and a flash ROM is included in the main body control unit 8 (main unit control unit). 8 may be provided).

  The storage unit 82 stores programs, data, and the like for controlling the copying machine 200. The main body control unit 8 uses the program and data in the storage unit to control each unit and perform printing. The main body control unit 8 is a main control unit that performs overall control, communication control, and image processing, an engine control unit that controls printing by performing ON / OFF of a motor that rotates an image forming and various rotating bodies, and the like. A plurality of types may be provided for each function. In this description, a form in which these control units are combined is shown and described.

  The main body control unit 8 includes a second image processing unit 83 that performs image processing based on image data obtained by processing of a first image processing unit 9 (details will be described later) provided in the image reading apparatus 100. It is done. For example, the second image processing unit 83 includes an ASIC (Application Specific Integrated Circuit), a memory, and the like, and performs various image processing such as density conversion processing, enlargement / reduction processing, rotation processing, image data compression / decompression processing, and the like. Can be done. Note that the second image processing unit 83 can perform other image processing (for example, frame erasing processing) and the like, but description thereof is omitted because it can perform known image processing.

  The main body control unit 8 is connected to the sheet feeding unit 4A, the conveyance path 4B, the image forming unit 5A, the intermediate transfer unit 5B, the fixing unit 5C, the operation panel 3, and the like. The main body control unit 8 controls the operation of each unit such as paper conveyance and toner image formation. Also, settings and copy execution instructions on the operation panel 3 are transmitted to the main body control unit 8. The main body control unit 8 is also connected to the image reading apparatus 100 and gives an operation instruction to the image reading apparatus 100 at the time of executing a copy. Then, the main body control unit 8 receives the image data of the document at the time of copying, and performs printing (copying) based on the image data.

(Hardware configuration of image reading apparatus 100)
Next, an example of the hardware configuration of the image reading apparatus 100 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing an example of the configuration of the image reading apparatus 100 according to the first embodiment of the present invention.

  As described above, the image reading apparatus 100 according to the present embodiment includes the document transport unit 2 and the image reading unit 1, and the document transport unit 2 controls the operation of the document transport unit 2. Is provided. On the other hand, the image reading unit 1 is provided with a reading control unit 10 that controls the operation of the image reading unit 1.

  First, the document conveyance control unit 20 will be described. The document conveyance control unit 20 is connected to the main body control unit 8 and the reading control unit 10 described above, and controls the operation of the document conveyance unit 2 in response to instructions and signals from the main body control unit 8 and the reading control unit 10. The document conveyance control unit 20 is, for example, a substrate including a CPU as a central processing unit, a ROM and a RAM as storage devices for storing control programs and data. The document conveyance control unit 20 communicates with the main body control unit 8 and the like, and receives an instruction from the main body control unit 8 and controls the operation of the document conveyance unit 2. For example, when a document reading instruction is issued from the main body control unit 8, the document transport motor 27 is driven to rotate the document supply roller 22, the document transport roller pair 24, and the like.

  Next, schematic configurations of the image reading unit 1 and the reading control unit 10 will be described. The reading control unit 10 is communicably connected to the main body control unit 8 and the document conveyance control unit 20 described above. The reading control unit 10 receives an instruction and a signal from the main body control unit 8 and controls the operation of the document conveying unit 2. The reading control unit 10 is also a substrate including a CPU as a central processing unit, a ROM and a RAM as storage devices for storing programs and data necessary for controlling the image reading device 100.

  Then, for example, when the start key 32 of the operation panel 3 is pressed, the reading control unit 10 receives an instruction from the main body control unit 8, and the reading control unit 10 controls the operation of the image reading apparatus 100 and the image data obtained by reading. Transmission control to the main body control unit 8 is performed.

  The reading control unit 10 is connected to a winding motor 13M. Thereby, the rotation of the winding motor 13M is controlled, the winding drum 134 is rotated, and each moving frame is moved. The reading control unit 10 is connected to the LED lamp 6, the image sensor 15, the A / D conversion unit 91, the first image processing unit 9, and the like, and is instructed to read the document, in other words, should be driven. Give instructions to that effect.

  The LED lamp 6 irradiates the original with line-shaped white light parallel to the main scanning direction. For example, the LED unit 61 may be configured to include a plurality of LEDs aligned in the main scanning direction, or a light guide (extending light incident from the end in the main scanning direction) extending in a direction parallel to the main scanning direction. It is good also as a structure provided with LED provided in the edge part of the main scanning direction of the said light guide. Moreover, even if an LED that outputs white light alone (for example, a combination of an LED that lights up in blue and a phosphor that receives the light from the LED and emits yellow light) is applied. It is also possible to apply a combination of a plurality of LEDs (for example, a combination of an LED that lights red, an LED that lights green, and an LED that lights blue) that outputs white light as a whole. Also good.

  As shown in FIG. 4, the LED lamp 6 is provided with a lighting circuit 62 as a switch for controlling lighting of LEDs (hereinafter simply referred to as LEDs) provided in the LED unit 61. The lighting circuit 62 may be configured to selectively light any LED. In this case, for example, all or some of the LEDs are connected in parallel.

  The image sensor 15 receives the light irradiated on the document, and outputs three types of analog electrical signals of R, G, and B for each pixel. The magnitude of the electrical signal varies depending on the amount of received light. The A / D conversion unit 91 receives the analog electrical signal of each pixel obtained by the image sensor 15, performs quantization, and converts the data into data including a digital electrical signal. For example, the A / D conversion unit 91 performs quantization on 8 bits (24 bits in total) for R, G, and B, respectively.

  The first image processing unit 9 (corresponding to an image data generation unit) receives the data output from the A / D conversion unit 91 and generates image data. In the present embodiment, an example in which the first image processing unit 9 is provided in the image reading unit 1 and the second image processing unit 83 is provided in the main body control unit 8 will be described. For example, one image processing unit is provided on the main body side. Only one image processing unit may be provided, and the processing of the first image processing unit 9 and the processing of the second image processing unit 83 in this description may be performed. In other words, only one image processing unit may be provided.

  In the first image processing unit 9, a work memory 92, a lighting control unit 93, a synchronization signal generation unit 94, a synthesis processing unit 95, a region separation unit 96, a selection synthesis unit 97, a correction processing unit 98, and the like are provided. The work memory 92 is a work area for data processing, and data output from the A / D conversion unit 91 is stored in the work memory 92. The synchronization signal generation unit 94 generates a synchronization signal for synchronizing with reading of the document. For example, the synchronization signal generator 94 generates a horizontal synchronization signal HSYNC for synchronization by reading one line.

  The horizontal synchronization signal HSYNC is given to the lighting control unit 93, the image sensor 15, and the A / D conversion unit 91, for example, when reading a document. For example, the lighting control unit 93 outputs a lighting instruction signal to the lighting circuit 62 in accordance with the horizontal synchronization signal HSYNC so that the LEDs are lit at a predetermined intensity and a predetermined timing. For example, the image sensor 15 starts outputting an electrical signal from the pixel at the head of one line in accordance with the horizontal synchronization signal HSYNC. For example, the A / D conversion unit 91 digitizes the electrical signal in accordance with the horizontal synchronization signal HSYNC and outputs data to the first image processing unit 9. The reading control unit 10 controls the operations of the document conveying unit 2 and the take-up motor 13M (that is, the relative positional relationship between the document and the light emitted from the LED lamp 6) in synchronization with the horizontal synchronization signal HSYNC. May be.

  The lighting control unit 93 outputs a lighting instruction signal to the lighting circuit 62, so that the LEDs can be lit in various different patterns. An example of the lighting pattern of LED is demonstrated based on FIG. FIG. 5 is an explanatory diagram illustrating an example of an LED lighting pattern according to the first embodiment.

  As shown in FIG. 5, the LED has a first pattern that lights for a first time at a first intensity, and a second pattern that lights for a second time that is smaller (weaker) than the first intensity and longer than the first time. Can be lit with a pattern. In addition, it is preferable that the whole light quantity irradiated by each pattern is substantially equal. Further, the lighting pattern shown in FIG. 5 is merely an example, and the LED may be lit in any lighting pattern as long as each lighting pattern is different. However, for the sake of concrete explanation, an example will be described below in which an LED is lit in one of the first pattern and the second pattern.

  When the original is irradiated with strong and short light by the first pattern, the time during which the light is incident on the image sensor 15 is shortened, and an electric signal (light corresponding to the image density of the original is photoelectrically converted) obtained by the image sensor 15. Averaging of the resulting electrical signal) is suppressed. Therefore, clear data can be obtained from the A / D converter 91. Specifically, data is obtained in which the signal value of the electrical signal at a nearby position can fluctuate sharply. Therefore, the first pattern is preferably applied at the time of reading a document including an image such as a character whose image density changes sharply. Specifically, for example, when the user selects a “character mode” for reading a document consisting of characters via the operation panel 3 of the copying machine 200, the lighting control unit 93 controls the lighting circuit 62, and the LED is It is preferable to control to light up in one pattern.

  When the original is irradiated with weak and long light by the second pattern, the time for the light to enter the image sensor 15 becomes long, and the averaging of the electrical signals obtained by the image sensor 15 is promoted. Therefore, smooth data can be obtained from the A / D conversion unit 91. Specifically, data in which signal values of electrical signals at adjacent positions are suppressed from abrupt fluctuations can be obtained. For this reason, the second pattern is preferably applied to a document including an image such as a photograph in which the image density does not easily change sharply. Specifically, for example, when the user selects the “photo mode” for reading a document consisting of a photograph via the operation panel 3 of the copying machine 200, the lighting control unit 93 controls the lighting circuit 62, and the LED is It is preferable to control to light up in two patterns.

  By the way, when different types of images such as characters and photographs are mixed in the original, specifically, for example, a “character / photo mode” in which the user reads an original composed of characters and photographs via the operation panel 3 of the copying machine 200. Is selected, the lighting control unit 93 controls the lighting circuit 62 so that the LEDs are lit in the first pattern and the second pattern. Details of the LED lighting method and the image data generation method in this case will be described later.

  The composition processing unit 95 generates data including one type of electrical signal indicating black and white (for example, luminance) from data including electrical signals of R, G, and B colors. For example, the composition processing unit 95 performs processing when generating data used for processing in the region separation unit 96 or generating monochrome (grayscale) image data. In the case where the image sensor 15 generates only an electrical signal indicating monochrome and the A / D conversion unit 91 generates only data indicating monochrome, the composition processing unit 95 may not be provided.

  The region separation unit 96 separates the data obtained from the A / D conversion unit 91 (including data processed by the composition processing unit 95) for each region corresponding to the type of image included in the document. Perform region separation processing. Any known process may be applied as the area separation process. For example, an edge detection process that detects the fluctuation amount of the signal value of the electrical signal may be applied.

  When performing edge detection processing, a filter for edge detection such as a differential filter (for example, Sobel filter, Previt filter, Laplacian filter) may be applied to the data. By applying such a filter to the data, the edge region (region where the signal value of the electrical signal at the adjacent position fluctuates sharply) and the other region (region where the signal value of the electric signal at the adjacent position varies little) ) And region separation data showing different signal values (for example, the signal value of the edge region is large and the signal value of the other region is small). That is, an area (edge area) obtained by reading an image such as a character whose image density changes sharply (an edge area), and an area (other area) obtained by reading an image such as a photograph whose image density does not change sharply. , Region separation data indicating different signal values are obtained.

  The selection / combination unit 97 refers to the region separation data obtained from the region separation unit 96 to recognize a region to which each electric signal included in the data obtained from the A / D conversion unit 91 belongs. And based on the recognized area | region, the electrical signal contained in the data obtained from the A / D conversion part 91 is selectively combined, and image data is produced | generated. Details of the operations of the region separation unit 96 and the selection combining unit 97 will be described later.

  The above-described region separation unit 96 and selection / combination unit 97 operate to generate image data mainly when images of different types are mixed in the document (for example, when the user selects “character / photo mode”). To do. In other cases (for example, when the user selects “text mode” or “photo mode”), the operation may not be performed. In this case, data obtained from the A / D conversion unit 91 and data obtained by the processing of the synthesis processing unit 95 are image data.

  The correction processing unit 98 corrects the distortion derived from the characteristics of the LED lamp 6 and the image sensor 15 such as gamma correction and shading correction on the image data obtained as described above. Note that the processing by the correction processing unit 98 may be performed before any of the synthesis processing unit 95, the region separation unit 96, and the selection synthesis unit 97 performs processing.

  The image data processed by the first image processing unit 9 is stored in the image memory 84 and then transferred to the main body control unit 8. Further, after the second image processing unit 83 performs image processing, for example, image data is given to the exposure device 51.

(Lighting control method and image data generation method)
Next, when different types of images are mixed in the document (for example, when the user selects “character / photo mode”), the lighting control method of the LED by the lighting control unit 93, the region separation unit 96, and the selection An example of a method for generating image data by the combining unit 97 will be described with reference to FIGS. FIG. 6 is a timing chart showing an example of the operation of the image reading apparatus according to the first embodiment. FIG. 7 is a conceptual diagram showing an example of a method for generating image data by the image reading apparatus according to the first embodiment. For the sake of specific description, an example in which the image reading apparatus 100 reads a document in which characters and photographic images are mixed will be described below.

  In FIG. 6, reading lines L1 to Ln (corresponding to unit areas, n is a natural number) that are lines of the document to be read are aligned in this order from one end to the other end in the sub-scanning direction of the document. And Further, as described above, the change of the original reading lines L1 to Ln (that is, the driving of the original conveying unit 2 or the take-up motor 13M) and the lighting of the LED are controlled in synchronization with the horizontal synchronization signal HSYNC. And For the sake of simplification, the reading lines L1 to Ln are switched intermittently (stepwise) in accordance with the horizontal synchronization signal HSYNC (the document conveying unit 2 and the take-up motor 13M operate intermittently). However, it may be configured so that it is continuously (gradually) switched (the document conveying section 2 and the take-up motor 13M operate continuously).

  As shown in FIG. 6, in this embodiment, when generating image data of one original, scanning is performed twice in which light is irradiated in order along the sub-scanning direction of the original. In the first scanning (scanning that sequentially irradiates light from the document reading lines L1 to Ln), the lighting control unit 93 outputs a lighting instruction signal to the lighting circuit 62 so that the LEDs are lit in the first pattern. In the second scanning (scanning that sequentially irradiates light from the document reading lines Ln to L1), the lighting control unit 93 outputs a lighting instruction signal to the lighting circuit 62 so that the LEDs are lit in the second pattern. .

  As shown in FIG. 7, the first data is output from the A / D converter 91 by the first scan and the second data is acquired by the first image processor 9 by the second scan. . Then, the region separation unit 96 applies the above region to at least one of the first data and the second data obtained from the A / D conversion unit 91 (including data processed by the synthesis processing unit 95). By performing the separation process, region separation data is generated. The region separation data indicates a region obtained by reading a character image and a region obtained by reading a photographic image in the first data and the second data.

  Then, the selection / combination unit 97 refers to the region separation data, so that the region obtained by reading the character image in the first data and the second data, the region obtained by reading the image of the photograph, Recognize each. Then, the selection / combination unit 97 selectively extracts an electrical signal of a region obtained by reading a character image from the first data, and sets it as the electrical signal of the region in the image data. Similarly, an electrical signal of a region obtained by reading a photographic image is selectively extracted from the second data, and is used as the electrical signal of the region in the image data. As described above, the selection / synthesis unit 97 selectively combines the electrical signals of the first data and the second data to generate image data.

  According to the first embodiment of the present invention, when generating image data of one original, a plurality of different patterns of light are emitted to the original. Therefore, even if different types of images are mixed in the original, it is possible to obtain each data including an electrical signal read using light suitable for each image in the original.

  Specifically, in the example shown in FIGS. 6 and 7, first data including an electrical signal read using light (first pattern) suitable for an image such as a character whose image density varies sharply, and image density The second data including the electrical signal read using the light (second pattern) suitable for an image such as a photograph that is difficult to change sharply can be obtained.

  Furthermore, the selective combining unit 97 generates image data by selectively combining electrical signals read using light suitable for each image in the document, thereby suppressing partial deterioration of the image data. be able to.

  Specifically, in the examples shown in FIGS. 6 and 7, image data such as characters whose image density changes sharply is clear, and images such as photographs where the image density hardly changes sharply are obtained. be able to.

  Note that the region separation unit 96 may perform region separation processing on the first data. In the first data, the signal value of the electrical signal may fluctuate sharply. Therefore, when the amount of change in the signal value of the electrical signal included in the first data is confirmed by applying edge detection processing as the region separation processing, it is obtained by reading an image such as a character whose image density changes sharply. Can be accurately separated from a region obtained by reading an image such as a photograph in which the image density is not likely to fluctuate sharply (a region having a relatively small amount of variation). it can. Further, the region separation unit 96 performs region separation processing on both the first data and the second data, and compares the respective results to generate region separation data that has been subjected to the region separation processing with high accuracy. Also good.

  Alternatively, the lighting control unit 93 may output a lighting instruction signal to the lighting circuit 62 so that the LED is lit in the second pattern in the first scan and is lit in the first pattern in the second scan.

  Further, when the selection / synthesis unit 97 generates image data by combining electrical signals selectively extracted from the first data and the second data, the selection / synthesis unit 97 may combine (for example, weighted addition) as necessary. . For example, an electrical signal in the vicinity of the boundary between a region where a character image is read and a region where a photographic image is read may be generated by the above synthesis.

  In addition, the direction of light applied to the document is reversed between the first scan and the second scan (for example, the rotation direction of the document transport motor 27 provided in the document transport unit 2 or the winding motor 13M is The first scanning and the second scanning are reversed), but the same direction may be used. However, the reverse direction as described above is preferable because reading (conveying the document and moving the first moving frame 131 and the second moving frame 132) can be performed smoothly.

(Second Embodiment)
Next, a second embodiment will be described based on FIG. FIG. 8 is a conceptual diagram illustrating an example of a method for generating image data by the image reading apparatus according to the second embodiment. The second embodiment is different from the first embodiment in the LED lighting control method by the lighting control unit 93 and the image data generation method by the region separation unit 96 and the selection synthesis unit 97. Is the same as in the first embodiment. Therefore, detailed description of the same parts as those in the first embodiment is omitted.

  Also in the second embodiment, similarly to the first embodiment, when generating image data of one original, scanning is performed twice in order to irradiate light in the sub-scanning direction of the original (FIG. 6). reference). In the first scanning (scanning that sequentially irradiates light from the document reading lines L1 to Ln), the lighting control unit 93 outputs a lighting instruction signal to the lighting circuit 62 so that the LEDs are lit in the first pattern. In the second scanning (scanning that sequentially irradiates light from the document reading lines Ln to L1), the lighting control unit 93 outputs a lighting instruction signal to the lighting circuit 62 so that the LEDs are lit in the second pattern. .

  However, in the second embodiment, the timing at which the LED is turned on in the second scan is controlled based on the data obtained in the first scan. Specifically, the lighting control unit 93 outputs a lighting instruction signal to the lighting circuit 62 so that the number of times the LED is lit in the second scanning is equal to or less than the first scanning.

  As shown in FIG. 8, the first data is output from the A / D conversion unit 91 and acquired by the first image processing unit 9 by the first scanning. Then, the region separation unit 96 performs the region separation process on the first data obtained from the A / D conversion unit 91 (which may include data processed by the synthesis processing unit 95), thereby performing region separation. Generate data. The region separation data indicates a region obtained by reading a character image and a region obtained by reading a photographic image in the first data.

  The lighting control unit 93 refers to the region separation data, so that the region obtained by reading the character image and the region obtained by reading the photo image in the first data and the second data, respectively. recognize. Then, the lighting control unit 93 determines the timing for lighting the LED in the second scan, and outputs a lighting instruction signal to the lighting circuit 62.

  Specifically, the lighting control unit 93 sends a lighting instruction signal to the lighting circuit 62 so that the LED lights at a timing estimated to read an image (photograph) suitable for the second pattern of light used in the second scan. Is output. At this time, the lighting control unit 93 may selectively control the LEDs to be lit. For example, in the second scanning, the LED that is estimated to irradiate light is selectively selected at a timing when the lighting control unit 93 is estimated to read an image (photograph) suitable for the second pattern of light. A lighting instruction signal may be output to the lighting circuit 62 so as to light up. In this case, for example, all or some of the LEDs are connected in parallel so that the lighting circuit 62 can selectively light any LED.

  As shown in FIG. 8, when the second scan as described above is performed, second data partially including an electrical signal read by irradiation with light is output from the A / D conversion unit 91. Acquired by the first image processing unit 9.

  Then, the selection / combination unit 97 refers to the region separation data, so that the region obtained by reading the character image in the first data and the second data, the region obtained by reading the image of the photograph, Recognize each. Then, the selection / combination unit 97 selectively extracts an electrical signal of a region obtained by reading a character image from the first data, and sets it as the electrical signal of the region in the image data. Similarly, an electrical signal of a region obtained by reading a photographic image is selectively extracted from the second data, and is used as the electrical signal of the region in the image data. As described above, the selection / synthesis unit 97 selectively combines the electrical signals of the first data and the second data to generate image data.

  According to the invention of the second embodiment, similarly to the first embodiment, when generating image data of one original, a plurality of different patterns of light are irradiated to the original, respectively. Therefore, even if different types of images are mixed in the original, it is possible to obtain each data including an electrical signal read using light suitable for each image in the original.

  Specifically, in the example shown in FIG. 8, the first data including an electrical signal read using light (first pattern) suitable for an image such as a character whose image density varies sharply, and the image density is steep. It is possible to obtain second data including an electrical signal read using light (second pattern) suitable for an image such as a photograph that does not easily change.

  Furthermore, the selective combining unit 97 generates image data by selectively combining electrical signals read using light suitable for each image in the document, thereby suppressing partial deterioration of the image data. be able to.

  Specifically, in the example illustrated in FIG. 8, it is possible to obtain image data in which an image such as a character whose image density varies sharply is clear and an image such as a photograph in which the image density hardly varies sharply is smooth. .

  In addition, according to the second embodiment, the number of times the LED is lit in the second scan can be made equal to or less than the first scan. Therefore, not only the above effects can be obtained, but also the power consumption can be reduced.

  Note that the lighting control unit 93 may output a lighting instruction signal to the lighting circuit 62 so that the LED is lit in the second pattern in the first scan and is lit in the first pattern in the second scan. In this case, the region separation unit 96 performs region separation processing on the second data obtained by the first scan.

  However, when reading using the first pattern is performed in the first scan, the first data in which the signal value of the electric signal can fluctuate sharply is obtained. Therefore, when the amount of change in the signal value of the electrical signal included in the first data is confirmed by applying edge detection processing as the region separation processing, it is obtained by reading an image such as a character whose image density changes sharply. Can be accurately separated from a region obtained by reading an image such as a photograph in which the image density is not likely to fluctuate sharply (a region having a relatively small amount of variation). it can. Therefore, power consumption can be effectively reduced.

  Further, when the selection / synthesis unit 97 generates image data by combining electrical signals selectively extracted from the first data and the second data, the selection / synthesis unit 97 may combine (for example, weighted addition) as necessary. . For example, an electrical signal in the vicinity of the boundary between a region where a character image is read and a region where a photographic image is read may be generated by the above synthesis.

  In addition, the direction of light applied to the document is reversed between the first scan and the second scan (for example, the rotation direction of the document transport motor 27 provided in the document transport unit 2 or the winding motor 13M is The first scanning and the second scanning are reversed), but the same direction may be used. However, the reverse direction as described above is preferable because the conveyance of the document and the movement of the first moving frame 131 and the second moving frame 132 can be performed smoothly.

(Third embodiment)
Next, a third embodiment will be described based on FIG. 9 and FIG. FIG. 9 is a timing chart illustrating an example of the operation of the image reading apparatus according to the third embodiment. FIG. 10 is a conceptual diagram showing an example of a method for generating image data by the image reading apparatus according to the third embodiment. The third embodiment is different from the first embodiment in the LED lighting control method by the lighting control unit 93 and the image data generation method by the region separation unit 96 and the selection synthesis unit 97. Is the same as in the first embodiment. Therefore, detailed description of the same parts as those in the first embodiment is omitted. FIG. 9 corresponds to FIG. 6 shown for the first embodiment, and the definition of FIG. 6 can be applied.

  As shown in FIG. 9, in the present embodiment, when generating image data of one original, scanning is performed once in which light is irradiated in order along the sub-scanning direction of the original. In this scanning (scanning that sequentially irradiates light from the document reading lines L1 to Ln), the lighting control unit 93 sends a lighting instruction signal to the lighting circuit 62 so that the LEDs are alternately lit in the first pattern and the second pattern. Output. In particular, when reading one reading line, the lighting control unit 93 outputs a lighting instruction signal to the lighting circuit 62 so that the LEDs are lit in the first pattern and the second pattern, respectively. The LEDs may be lit in the order of the first pattern and the second pattern as shown in FIG. 9, or may be lit in the reverse order (the order of the second pattern and the first pattern).

  As shown in FIG. 10, in the above scanning, the first data is output from the A / D converter 91 when the LEDs are lit in the first pattern, and the second data is output as the second pattern is lit. , Acquired by the first image processing unit 9. Then, the region separation unit 96 applies the above region to at least one of the first data and the second data obtained from the A / D conversion unit 91 (including data processed by the synthesis processing unit 95). By performing the separation process, region separation data is generated. The region separation data indicates a region obtained by reading a character image and a region obtained by reading a photographic image in the first data and the second data.

  Then, the selection / combination unit 97 refers to the region separation data, so that the region obtained by reading the character image in the first data and the second data, the region obtained by reading the image of the photograph, Recognize each. Then, the selection / combination unit 97 selectively extracts an electrical signal of a region obtained by reading a character image from the first data, and sets it as the electrical signal of the region in the image data. Similarly, an electrical signal of a region obtained by reading a photographic image is selectively extracted from the second data, and is used as the electrical signal of the region in the image data. As described above, the selection / synthesis unit 97 selectively combines the electrical signals of the first data and the second data to generate image data.

  According to the invention of the third embodiment, similarly to the first embodiment, when generating image data of one original, a plurality of different patterns of light are irradiated to the original. Therefore, even if different types of images are mixed in the original, it is possible to obtain each data including an electrical signal read using light suitable for each image in the original.

  Specifically, in the example shown in FIGS. 9 and 10, first data including an electrical signal read using light (first pattern) suitable for an image such as a character whose image density varies sharply, and the image density The second data including the electrical signal read using the light (second pattern) suitable for an image such as a photograph that is difficult to change sharply can be obtained.

  Furthermore, the selective combining unit 97 generates image data by selectively combining electrical signals read using light suitable for each image in the document, thereby suppressing partial deterioration of the image data. be able to.

  Specifically, in the example shown in FIGS. 9 and 10, image data such as a character whose image density changes sharply is clear and an image data such as a photograph where the image density is difficult to change sharply is obtained. be able to.

  Further, according to the third embodiment, the first data and the second data can be obtained by one scan. Therefore, not only the above effects can be obtained but also smooth reading can be performed. Specifically, for example, in the case of reading in which the first moving frame 131 and the second moving frame 132 are fixed and the document is transported by the document transport unit 2, if the number of times of transport of the document is 1, the document transport unit 2 can prevent the document from being jammed. Further, the document conveying unit 2 performs conveyance twice such that one surface (surface to be read) of one document faces the LED lamp 6 (performs conveyance different from conveyance for reading both sides of the document). , Can be unnecessary. Therefore, it is possible to prevent the configuration of the document conveying unit 2 from becoming complicated.

  Note that the region separation unit 96 may perform region separation processing on the first data. In the first data, the signal value of the electrical signal may fluctuate sharply. Therefore, when the amount of change in the signal value of the electrical signal included in the first data is confirmed by applying edge detection processing as the region separation processing, it is obtained by reading an image such as a character whose image density changes sharply. Can be accurately separated from a region obtained by reading an image such as a photograph in which the image density is not likely to fluctuate sharply (a region having a relatively small amount of variation). it can. Further, the region separation unit 96 performs region separation processing on both the first data and the second data, and compares the respective results to generate region separation data that has been subjected to the region separation processing with high accuracy. Also good.

  Further, when the selection / synthesis unit 97 generates image data by combining electrical signals selectively extracted from the first data and the second data, the selection / synthesis unit 97 may combine (for example, weighted addition) as necessary. . For example, an electrical signal in the vicinity of the boundary between a region where a character image is read and a region where a photographic image is read may be generated by the above synthesis.

  In the first to third embodiments, the copying machine 200 including the image reading apparatus 100 is taken as an example. However, the present invention is an image reading apparatus such as a scanner, and the copying machine 200 including the image reading apparatus. The present invention can also be applied to apparatuses other than those (for example, multifunction peripherals and facsimile machines).

  Further, the image reading apparatus 100 may selectively perform the LED lighting control method and the image data generation method in the first to third embodiments according to the situation. For example, in the case of reading performed by fixing the first moving frame 131 and the second moving frame 132 and conveying the document by the document conveying unit 2, the LED lighting control method and the image data generation method of the third embodiment May be performed. On the other hand, when reading a document placed on the placement reading contact glass 12 by moving the first moving frame 131 and the second moving frame 132, the LED of the first or second embodiment is turned on. You may perform the control method and the production | generation method of image data.

  The embodiment of the present invention has been described above, but the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be used for an image reading apparatus and an image forming apparatus including the image reading apparatus.

DESCRIPTION OF SYMBOLS 1 Image reading part 2 Original conveyance part 12 Placement reading contact glass 13M Winding motor (drive part)
15 Image sensor 6 LED lamp (lighting part)
61 LED section 62 lighting circuit 9 first image processing section (image data generation section) 91 A / D conversion section 93 lighting control section 96 area separation section 97 selection combining section 100 image reading apparatus 200 copier (image forming apparatus)

Claims (12)

A lighting unit that emits light to the document;
An image sensor that converts light reflected by the document into an electrical signal;
An image data generation unit that generates image data using an electrical signal obtained from the image sensor;
A lighting control unit that controls the light that the lighting unit irradiates the document;
When the image data generation unit generates the image data of the one original, the lighting control unit is configured to irradiate at least a part of the original with a plurality of different patterns of light. An image reading apparatus characterized by controlling a section.   By irradiating the original with a plurality of different patterns of light, the image data generator selectively combines the electrical signals obtained from the image sensor to generate image data of the original. The image reading apparatus according to claim 1, wherein: A first pattern irradiated to the original at a first intensity for a first time and a second pattern irradiated at a second intensity smaller than the first intensity for a second time longer than the first time. And the lighting control unit controls the lighting unit so that each of the light is irradiated,
A first electrical signal obtained from the image sensor by irradiating the original pattern with light of the first pattern, and an image sensor by irradiating the original document with light of the second pattern. The image reading apparatus according to claim 2, wherein the image data generation unit generates image data of the original by selectively combining the obtained second electric signal. When the image data generation unit generates image data of one original, the original is scanned once by the lighting unit to sequentially irradiate light along a predetermined direction.
In the scanning, the lighting control unit is configured to irradiate the light of the first pattern and the light of the second pattern respectively to each unit area formed by dividing the document along the predetermined direction. The image reading apparatus according to claim 3, wherein the lighting unit is controlled. When the image data generation unit generates image data of one original, the document is scanned twice by the lighting unit sequentially irradiating light along a predetermined direction.
In the first scanning, one of the light of the first pattern and the light of the second pattern is irradiated to the original,
The lighting control unit controls the lighting unit so that the other of the light of the first pattern and the light of the second pattern is irradiated to the original in the second scanning. The image reading apparatus according to claim 3. The image data generation unit determines the timing at which the lighting unit should irradiate light in the second scan based on the electrical signal obtained from the image sensor in the first scan.
The image reading apparatus according to claim 5, wherein the lighting control unit controls the lighting unit so that light is emitted to the original at the second timing of the scanning. The lighting control is performed so that the first pattern light is irradiated to the original document at the first scanning, and the second pattern light is applied to the original document at the second scanning. The part controls the lighting part,
The image data generation unit detects a fluctuation amount for each predetermined region of the first electric signal obtained in the first scan;
In the second scanning, the lighting control unit is configured to irradiate the document with light at a timing of reading a region in the document corresponding to a region where the variation amount of the first electric signal is relatively small. 7. The image reading apparatus according to claim 6, wherein the lighting unit is controlled.   The direction in which light is sequentially applied to the original in the first scan and the direction in which light is sequentially applied to the original in the second scan are opposite directions. The image reading apparatus according to claim 5. The image data generation unit detects a variation amount for each predetermined region for at least one of the first electric signal and the second electric signal;
The image data generation unit selects and combines the first electrical signal in a region where the variation is relatively large, and selects and combines the second electrical signal in a region where the variation is relatively small. 9. The image reading apparatus according to claim 3, wherein the image reading apparatus generates data. The image data generation unit detects a variation amount for each predetermined region of the first electric signal,
The image data generation unit selects the first electrical signal in a region where the variation amount of the first electrical signal is relatively large, and selects the second electrical signal in a region where the variation amount of the first electrical signal is relatively small. The image reading apparatus according to claim 9, wherein the image data is selected and combined to generate image data of one original. A drive unit that moves the lighting unit with respect to a predetermined direction of the document; or a document transport unit that moves the document with respect to the lighting unit in a predetermined direction.
The driving unit moves the lighting unit, or the document conveying unit moves the document, so that the lighting unit scans the document sequentially with light along a predetermined direction. The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus.   An image forming apparatus comprising the image reading apparatus according to claim 1.

Images