Image reading device, image forming apparatus, and reading condition adjustment method

Abstract

To provide an image reading device, an image forming apparatus, and a reading condition adjustment method that can read a shadow occurring at a leading end of a document regardless of the type of an image sensor.SOLUTION: An image forming apparatus 100 comprises: a second imaging unit 43 that has a first light emitting unit 43C that emits light toward a reading position P1 from the upstream side of the reading position P1 in a conveyance direction D1 of a document X1, and outputs image data including an image of the document X1 passing through the reading position P1 by using the first light emitting unit 43C; an identification processing unit that identifies the type of the second imaging unit 43; and an adjustment processing unit that, on the basis of an identification result from the identification processing unit, adjusts a specific condition related to formation of a shadow SH1 at a leading end of the document X1, of reading conditions for the image of the document X1 by using the second imaging unit 43.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an image reading apparatus, an image forming apparatus, and a reading condition adjustment method.

Background Art

[0002] There is known an image reading apparatus capable of reading an image of a document conveyed via a predetermined reading position (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the image reading apparatus, the posture of the read image may be corrected based on a shadow image included in the read image read from the document. The shadow image is an image showing a shadow generated when the leading edge of the document passes through the reading position.

[0005] In addition, in the image reading apparatus, when the image sensor used for reading the image of the document is replaced, the type of the image sensor provided in the image reading apparatus may be switched.

[0006] Here, when the type of the image sensor provided in the image reading apparatus is switched, the shadow generated when the leading edge of the document passes through the reading position becomes thin, and it may not be possible to read the shadow.

[0007] An object of the present invention is to provide an image reading apparatus, an image forming apparatus, and a reading condition adjustment method capable of reading a shadow generated at the leading edge of a document regardless of the type of an image sensor.

Means for Solving the Problem

[0008] An image reading apparatus according to one aspect of the present invention includes a document conveyance unit, an image sensor, an identification processing unit, and an adjustment processing unit. The document conveyance unit conveys a document along a predetermined conveyance path. The image sensor has a first light emitting unit that emits light from an upstream side in the conveyance direction of the document than a predetermined reading position in the conveyance path toward the reading position, and outputs image data including an image of the document passing through the reading position using the first light emitting unit. The identification processing unit identifies the type of the image sensor. The adjustment processing unit adjusts a specific condition related to the generation of a shadow that occurs when the leading edge of the document passes through the reading position among the reading conditions of the image of the document using the image sensor based on the identification result by the identification processing unit.

[0009] An image forming apparatus according to another aspect of the present invention includes the image reading apparatus, and forms an image on a sheet based on the image data output from the image reading apparatus.

[0010] A reading condition adjustment method according to another aspect of the present invention is executed by an image reading apparatus including a document conveyance unit that conveys a document along a predetermined conveyance path and an image sensor that has a first light emitting unit that emits light from an upstream side in the conveyance direction of the document than a predetermined reading position in the conveyance path toward the reading position, and outputs image data including an image of the document passing through the reading position using the first light emitting unit, and includes an identification step and an adjustment step. In the identification step, the type of the image sensor is identified. In the adjustment step, a specific condition related to the generation of a shadow that occurs when the leading edge of the document passes through the reading position among the reading conditions of the image of the document using the image sensor is adjusted based on the identification result by the identification step.

Advantages of the Invention

[0011] According to the present invention, regardless of the type of image sensor, it is possible to read the shadow generated at the leading edge of the document.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiments are an example of embodying the present invention and do not limit the technical scope of the present invention.

[0014] [Configuration of Image Forming Apparatus 100] First, with reference to FIG. 1, the configuration of an image forming apparatus 100 according to an embodiment of the present invention will be described.

[0015] The image forming apparatus 100 is a multifunction device having a plurality of functions such as a scan function for reading an image from a document X1 (see FIG. 3), a print function for forming an image on a sheet based on image data, a fax function, and a copy function. Note that the image forming apparatus of the present invention may be a fax device or a copy machine.

[0016] As shown in FIG. 1, the image forming apparatus 100 includes an ADF (Auto Document Feeder) 1, an image reading unit 2, an image forming unit 3, a paper feeding unit 4, an operation display unit 5, a storage unit 6, and a control unit 7.

[0017] ADF1 conveys the original document X1 from which an image is read by the scanning function.

[0018] The image reading unit 2 realizes the scanning function. Specifically, the image reading unit 2 reads an image from the original document X1 conveyed by ADF1. Further, the image reading unit 2 reads an image from the original document X1 placed on the document table 41 (see FIG. 2).

[0019] The image forming unit 3 realizes the printing function. For example, the image forming unit 3 forms an image on a sheet supplied from the paper feeding unit 4 by an electrophotographic method. For example, the image forming unit 3 includes a photosensitive drum, a charging roller, an optical scanning device, a developing device, a transfer roller, a cleaning device, and a fixing device. The image forming apparatus 100 forms an image on a sheet based on the image data output from the image reading unit 2 using the image forming unit 3. Note that the image forming unit 3 may form an image on a sheet by a method different from the electrophotographic method such as an inkjet method.

[0020] The paper feeding unit 4 supplies a sheet to the image forming unit 3. For example, the paper feeding unit 4 includes a paper feeding cassette, a manual feed tray, a sheet conveyance path, and a plurality of conveyance rollers.

[0021] The operation display unit 5 is a user interface of the image forming apparatus 100. The operation display unit 5 includes a display unit and an operation unit. The display unit displays various information in response to a control instruction from the control unit 7. For example, the display unit is a liquid crystal display. The operation unit inputs various information to the control unit 7 in response to a user operation. For example, the operation unit is a touch panel.

[0022] The storage unit 6 is a non-volatile storage device. For example, the storage unit 6 is a non-volatile memory such as a flash memory. Note that the storage unit 6 may be an SSD (Solid State Drive) or an HDD (Hard Disk Drive).

[0023] The control unit 7 comprehensively controls the image forming apparatus 100. As shown in FIG. 1, the control unit 7 includes a CPU 11, a ROM 12, and a RAM 13. The CPU 11 is a processor that executes various arithmetic processes. The ROM 12 is a non-volatile storage device in which information such as control programs for causing the CPU 11 to execute various processes is stored in advance. The RAM 13 is a volatile or non-volatile storage device used as a temporary storage memory (working area) for various processes executed by the CPU 11. In the control unit 7, various control programs stored in advance in the ROM 12 are executed by the CPU 11. Thereby, the control unit 7 comprehensively controls the image forming apparatus 100. Note that the control unit 7 may be configured by an electronic circuit such as an integrated circuit (ASIC). Further, the control unit 7 may be a control unit provided separately from the main control unit that comprehensively controls the image forming apparatus 100.

[0024] [Configuration of ADF1 and Image Reading Unit 2] Next, with reference to FIGS. 1 to 3, the configuration of the ADF1 and the image reading unit 2 will be described. Here, FIG. 2 is a cross-sectional view showing the configuration of the ADF1 and the image reading unit 2. Further, FIG. 3 is a cross-sectional view showing the configuration of the second imaging unit 43. In FIG. 3, hatching is applied to the shadow SH1.

[0025] As shown in FIG. 2, the ADF1 includes a document placement unit 21, a housing 22, a pickup roller 23, a paper feed belt 24, a separation roller 25, a registration roller 26, a first conveyance roller 27, a second conveyance roller 28, a discharge roller 29, and a discharge unit 30.

[0026] A document X1 to be conveyed is placed on the document placement unit 21. In the ADF1, the document X1 placed on the document placement unit 21 is conveyed in the conveyance direction D1 shown in FIG. 2.

[0027] A lift plate (not shown) is provided on the document placement unit 21. The lift plate lifts one or a plurality of documents X1 placed on the document placement unit 21 to the contact position with the pickup roller 23.

[0028] The housing 22 houses rollers and the like used for conveying the original X1. As shown in FIG. 2, a conveyance path 22A is formed inside the housing 22. The conveyance path 22A guides the original X1 along a predetermined conveyance path. Specifically, the conveyance path is a path that leads from the original placement unit 21 to the reading position P1 (see FIG. 2) and the discharge unit 30 via the opening 22B (see FIG. 2).

[0029] As shown in FIG. 2, an opening 22B is provided at the bottom of the housing 22. The opening 22B exposes the surface of the original X1 conveyed along the conveyance path to the outside. The surface facing upward in the original X1 placed on the original placement unit 21 is the surface of the original X1. At the opening 22B, the first imaging unit 42 (see FIGS. 1 and 2) of the image reading unit 2 reads an image of the surface of the original X1 conveyed by the ADF1.

[0030] As shown in FIG. 2, the pickup roller 23 is provided above the original placement unit 21. The pickup roller 23 contacts the surface (upper surface) of the uppermost original X1 among one or a plurality of originals X1 lifted by the lift plate, and conveys the original X1 in the conveyance direction D1.

[0031] As shown in FIG. 2, the paper feed belt 24 is provided in the conveyance path 22A. The paper feed belt 24 contacts the surface of the original X1 conveyed in the conveyance direction D1 by the pickup roller 23, and conveys the original X1 to the downstream side in the conveyance direction D1.

[0032] As shown in FIG. 2, the separation roller 25 is provided in contact with the paper feed belt 24 below the paper feed belt 24. The separation roller 25 separates the original X1 in contact with the paper feed belt 24 from the original X1 below the original X1 among the plurality of originals X1 conveyed to the contact position with the paper feed belt 24.

[0033] As shown in FIG. 2, the resist roller 26 is provided on the downstream side of the paper feed belt 24 in the conveyance path 22A in the conveyance direction D1 and on the upstream side of the first conveyance roller 27 in the conveyance direction D1. The resist roller 26 contacts the document X1 conveyed by the paper feed belt 24 and conveys the document X1 to the downstream side in the conveyance direction D1.

[0034] As shown in FIG. 2, the first conveyance roller 27 is provided on the downstream side of the resist roller 26 in the conveyance path 22A in the conveyance direction D1 and on the upstream side of the second conveyance roller 28 in the conveyance direction D1. The first conveyance roller 27 contacts the document X1 conveyed by the resist roller 26 and conveys the document X1 to the downstream side in the conveyance direction D1.

[0035] As shown in FIG. 2, an opening 22B is formed on the downstream side of the first conveyance roller 27 in the conveyance direction D1 in the conveyance path 22A and on the upstream side of the second conveyance roller 28 in the conveyance direction D1. In the opening 22B, an image of the surface of the document X1 passing through the opening 22B is read by the first imaging unit 42 (see FIGS. 1 and 2) of the image reading unit 2.

[0036] As shown in FIG. 2, the second conveyance roller 28 is provided on the downstream side of the opening 22B in the conveyance direction D1 in the conveyance path 22A and on the upstream side of the discharge roller 29 in the conveyance direction D1. The second conveyance roller 28 contacts the document X1 conveyed by the first conveyance roller 27 and conveys the document X1 to the downstream side in the conveyance direction D1.

[0037] As shown in FIG. 2, the discharge roller 29 is provided on the downstream side of the second conveyance roller 28 in the conveyance direction D1 in the conveyance path 22A. The discharge roller 29 contacts the document X1 conveyed by the second conveyance roller 28 and discharges the document X1 to the discharge unit 30. The discharged document X1 is stacked in the discharge unit 30.

[0038] In the ADF1, the original document X1 placed on the original document placement unit 21 is conveyed along the conveyance path by the pickup roller 23, the paper feed belt 24, the registration roller 26, the first conveyance roller 27, the second conveyance roller 28, and the discharge roller 29. The pickup roller 23, the paper feed belt 24, the registration roller 26, the first conveyance roller 27, the second conveyance roller 28, and the discharge roller 29 are an example of the original document conveyance unit of the present invention.

[0039] As shown in FIGS. 1 and 2, the image reading unit 2 includes a document table 41, a first imaging unit 42, a second imaging unit 43, an image processing unit 44, a shading roller 45, and a moving unit 46.

[0040] On the document table 41, the original document X1 to be read is placed. The document table 41 is provided at the upper part of the housing of the image forming apparatus 100 (see FIG. 2). The ADF1 is provided so as to be openable and closable with respect to the document table 41, and also serves as a document cover that supports one surface of the original document X1 placed on the first contact glass 41A of the document table 41.

[0041] As shown in FIG. 2, the document table 41 includes a first contact glass 41A, a second contact glass 41B, and a guide member 41C. On the first contact glass 41A, the original document X1 whose image is read by the first imaging unit 42 is placed. The second contact glass 41B and the guide member 41C close the opening 22B of the housing 22 and form a part of the conveyance path 22A when the ADF1 is in a state of closing the document table 41. The second contact glass 41B transmits the light emitted from the first imaging unit 42 toward the opening 22B and the light reflected by the surface of the original document X1. The guide member 41C guides the original document X1 to the second conveyance roller 28 on the downstream side in the conveyance direction D1 from the second contact glass 41B.

[0042] As shown in FIG. 2, the first imaging unit 42 is provided below the first contact glass 41A and the second contact glass 41B. The first imaging unit 42 is long in the depth direction of the paper surface in FIG. 2 and is provided so as to be movable along the left-right direction of the paper surface in FIG. 2. The first imaging unit 42 reads an image of the surface of the document X1 conveyed by the ADF1 while being disposed below the second contact glass 41B. Specifically, the first imaging unit 42 is a CIS (Contact Image Sensor). The first imaging unit 42 outputs image data including the image read from the surface of the document X1.

[0043] As shown in FIG. 2, the second imaging unit 43 is provided on the downstream side in the conveyance direction D1 of the resist roller 26 in the conveyance path 22A and on the upstream side in the conveyance direction D1 of the first conveyance roller 27. The second imaging unit 43 is long in the depth direction of the paper surface in FIG. 2. The second imaging unit 43 is provided on the side facing the back surface of the document X1 in the conveyance path 22A. The second imaging unit 43 reads an image of the back surface of the document X1. Specifically, the second imaging unit 43 is a CIS. The second imaging unit 43 outputs image data including the image read from the back surface of the document X1.

[0044] As shown in FIG. 3, the second imaging unit 43 includes a housing 43A, a light-transmitting part 43B, a first light-emitting part 43C, a second light-emitting part 43D, a lens 43E, a photoelectric conversion part 43F, and an AFE (Analog Front End) 43G.

[0045] The housing 43A houses the first light-emitting part 43C, the second light-emitting part 43D, the lens 43E, and the photoelectric conversion part 43F. For example, the housing 43A is formed in a box shape that is long in the depth direction of the paper surface in FIG. 3. The AFE 43G is provided on the bottom surface of the housing 43A. An opening that is long in the depth direction of the paper surface in FIG. 3 is formed in the upper part of the housing 43A. The light-transmitting part 43B is provided in the opening.

[0046] The light-transmitting part 43B is a transparent member that closes the opening of the housing 43A. For example, the light-transmitting part 43B is a glass plate. The light-transmitting part 43B transmits the light emitted from the first light-emitting part 43C and the second light-emitting part 43D. Further, the light-transmitting part 43B transmits the light that is emitted from the first light-emitting part 43C and the second light-emitting part 43D, passes through the reading position P1, and is reflected by the document X1.

[0047] As shown in FIG. 3, the first light-emitting part 43C emits light from the upstream side of the conveyance direction D1 of the document X1 toward the reading position P1 from a position upstream of a predetermined reading position P1 (see FIGS. 2 and 3) in the conveyance path. For example, the first light-emitting part 43C is a light-emitting diode that emits white light.

[0048] As shown in FIG. 3, the second light-emitting part 43D emits light from the downstream side of the conveyance direction D1 toward the reading position P1 from a position downstream of the reading position P1 (see FIGS. 2 and 3) in the conveyance path. For example, the second light-emitting part 43D is a light-emitting diode that emits white light.

[0049] The lens 43E condenses the light that is emitted from the first light-emitting part 43C and the second light-emitting part 43D, passes through the reading position P1, and is reflected by the document X1 onto the photoelectric conversion part 43F.

[0050] The photoelectric conversion part 43F outputs an analog electrical signal based on the light that is emitted from the first light-emitting part 43C and the second light-emitting part 43D, passes through the reading position P1, and is reflected by the document X1.

[0051] The AFE 43G converts the analog electrical signal output from the photoelectric conversion part 43F into a digital electrical signal (image data) and outputs it.

[0052] The second imaging part 43 outputs image data including an image of the back surface of the document X1 that passes through the reading position P1 by using the first light-emitting part 43C and the second light-emitting part 43D. The second imaging part 43 is an example of the image sensor of the present invention.

[0053] The image processing unit 44 executes predetermined image processing on the image data output from the second imaging unit 43. Specifically, the image processing unit 44 is a substrate on which an electronic circuit for executing the image processing is mounted. For example, the image processing unit 44 is provided on the bottom surface of the housing 43A of the second imaging unit 43 and is connected to the AFE 43G via a cable. For example, the image processing includes shading correction. The image data subjected to the image processing by the image processing unit 44 is input to the control unit 7.

[0054] As shown in FIGS. 2 and 3, the shading roller 45 is provided to face the second imaging unit 43 with the reading position P1 interposed therebetween. As shown in FIG. 2, the shading roller 45 is provided on the side facing the surface of the document X1 in the conveyance path 22A. The shading roller 45 has an outer peripheral surface colored with a predetermined reference color. For example, the reference color is white. Correction data used for the shading correction is read from the outer peripheral surface of the shading roller 45. The shading roller 45 is an example of the opposing portion of the present invention. Note that the opposing portion of the present invention is not limited to a roller-shaped member and may be a plate-shaped member.

[0055] For example, the shading roller 45 is rotatably supported by a pair of bearing portions provided on both outer sides of the shading roller 45 in the longitudinal direction of the shading roller 45. Further, the pair of bearing portions are movably supported by the housing 22 of the ADF 1 along the opposing direction D2 (see FIG. 3).

[0056] The moving unit 46 moves the shading roller 45 along the opposing direction D2 (see FIG. 3) with respect to the second imaging unit 43. The opposing direction D2 is a direction orthogonal to the surface and the back surface of the document X1. Further, the opposing direction D2 is a direction intersecting the horizontal plane. Note that, as shown in FIGS. 2 and 3, the second imaging unit 43 is provided below the shading roller 45.

[0057] For example, the moving part 46 includes a pair of cams that support the pair of bearing parts below the pair of bearing parts, and a motor that rotates the pair of cams. The pair of cams are provided so as to be integrally rotatable. The pair of cams receive a rotational driving force supplied from the motor and rotate, thereby swinging the pair of bearing parts along the facing direction D2.

[0058] The control unit 7 corrects the posture of the read image based on the shadow image included in the read image read from the document X1 using the second imaging unit 43. The shadow image is an image showing a shadow SH1 (see FIG. 3) generated when the leading edge of the document X1 passes through the reading position P1. Specifically, the control unit 7 rotates the read image so that the inclination angle of the shadow image with respect to the main scanning direction becomes zero.

[0059] Further, the control unit 7 determines the size in the width direction orthogonal to the conveyance direction D1 of the document X1 based on the shadow image. Specifically, the control unit 7 determines the size in the width direction of the document X1 based on the size in the longitudinal direction of the shadow image.

[0060] By the way, in the image forming apparatus 100, when the second imaging unit 43 is replaced due to a failure or the like, the type of the second imaging unit 43 provided in the image forming apparatus 100 may be switched.

[0061] Here, when the type of the second imaging unit 43 provided in the image forming apparatus 100 is switched, the shadow SH1 (see FIG. 3) generated when the leading edge of the document X1 passes through the reading position P1 becomes thinner, and it may not be possible to read the shadow SH1.

[0062] Specifically, when the type of the second imaging unit 43 is switched, the incident angle AN1 (see FIG. 3) of the light emitted from the first light emitting unit 43C with respect to the document X1 may become smaller. As a result, the width W1 (see FIG. 3) of the shadow SH1 along the conveyance direction D1 becomes smaller, and the shadow SH1 becomes thinner.

[0063] If the reading of the shadow SH1 fails, the posture correction of the read image based on the shadow image and the determination of the size in the width direction of the original document X1 cannot be performed.

[0064] On the other hand, in the image forming apparatus 100 according to the embodiment of the present invention, as will be described below, regardless of the type of the second imaging unit 43, it is possible to read the shadow SH1 generated at the leading edge of the original document X1.

[0065] [Configuration of Control Unit 7] Next, the configuration of the control unit 7 will be described with reference to FIGS. 1 and 3.

[0066] As shown in FIG. 1, the control unit 7 includes an identification processing unit 51 and an adjustment processing unit 52.

[0067] Specifically, in the ROM 12 of the control unit 7, a reading condition adjustment program for causing the CPU 11 to execute the reading condition adjustment process (see FIG. 4) described later is stored in advance. Then, the CPU 11 functions as the identification processing unit 51 and the adjustment processing unit 52 by executing the reading condition adjustment program stored in the ROM 12. The apparatus including the ADF 1, the image reading unit 2, and the control unit 7 is an example of the image reading apparatus of the present invention.

[0068] Note that the reading condition adjustment program may be recorded on a computer-readable recording medium such as a CD, a DVD, and a flash memory, and may be read from the recording medium and stored in a storage device such as the storage unit 6. Also, a part or all of the processing units included in the control unit 7 may be configured by an electronic circuit. Further, the reading condition adjustment program may be a program for causing a plurality of processors to function as each processing unit included in the control unit 7.

[0069] The identification processing unit 51 identifies the type of the second imaging unit 43.

[0070] For example, in the image forming apparatus 100, the image processing unit 44 can output a type signal corresponding to the type of the second imaging unit 43.

[0071] Then, the identification processing unit 51 identifies the type of the second imaging unit 43 based on the type signal output from the image processing unit 44.

[0072] For example, the identification processing unit 51 identifies whether the second imaging unit 43 provided in the image forming apparatus 100 is the second imaging unit 43 of product A or the second imaging unit 43 of product B based on the type signal output from the image processing unit 44.

[0073] For example, the incident angle AN1 (see FIG. 3) of the second imaging unit 43 of product B is smaller than that of the second imaging unit 43 of product A. That is, in the image forming apparatus 100 including the second imaging unit 43 of product B, it is more difficult to read the shadow SH1 than in the image forming apparatus 100 including the second imaging unit 43 of product A.

[0074] Note that the identification processing unit 51 may identify the type of the second imaging unit 43 from three or more types.

[0075] Also, the second imaging unit 43 may have a function of outputting the type information. In this case, the identification processing unit 51 may identify the type of the second imaging unit 43 based on the type signal output from the second imaging unit 43.

[0076] Also, the second imaging unit 43 may include a type display unit that displays the type of the second imaging unit 43 on the outer surface of the housing 43A. For example, the type display unit is a label, a barcode, or the like that includes information indicating the type of the second imaging unit 43. Also, the type display unit may be in a shape for identifying the type of the second imaging unit 43. In this case, the identification processing unit 51 may identify the type of the second imaging unit 43 using a reading unit that can read the type of the second imaging unit 43 displayed by the type display unit.

[0077] Based on the identification result by the identification processing unit 51, the adjustment processing unit 52 adjusts specific conditions related to the generation of a shadow SH1 (see FIG. 3) that occurs when the leading edge of the document X1 passes through the reading position P1 among the reading conditions of the image of the document X1 using the second imaging unit 43.

[0078] For example, the specific conditions include the light quantity ratio of the emitted light quantity of the first light emitting unit 43C and the emitted light quantity of the second light emitting unit 43D.

[0079] Further, the specific conditions include the separation distance between the second imaging unit 43 and the shading roller 45 in the facing direction D2.

[0080] For example, in the image forming apparatus 100, table data in which the type of the second imaging unit 43, the emitted light quantity of the first light emitting unit 43C, the emitted light quantity of the second light emitting unit 43D, and the separation distance are associated is stored in the storage unit 6 in advance.

[0081] For example, in the table data, the emitted light quantity of the second light emitting unit 43D corresponding to the second imaging unit 43 of product name B is set to be smaller than the emitted light quantity of the second light emitting unit 43D corresponding to the second imaging unit 43 of product name A. Thereby, when the second imaging unit 43 provided in the image forming apparatus 100 is the second imaging unit 43 of product name B (where it is relatively difficult to read the shadow SH1), it is possible to reduce the emitted light quantity of the second light emitting unit 43D that emits light (to make it thinner) to illuminate the shadow SH1.

[0082] Further, in the table data, the emitted light quantity of the first light emitting unit 43C corresponding to the second imaging unit 43 of product name B is set to be larger than the emitted light quantity of the first light emitting unit 43C corresponding to the second imaging unit 43 of product name A. Thereby, when the second imaging unit 43 provided in the image forming apparatus 100 is the second imaging unit 43 of product name B (where it is relatively difficult to read the shadow SH1), it is possible to increase the emitted light quantity of the first light emitting unit 43C that emits light (to make it darker) to generate the shadow SH1.

[0083] In the table data, the total value of the emission light amount of the first light emission unit 43C corresponding to the second imaging unit 43 of product name A and the emission light amount of the second light emission unit 43D is set to be the same as the total value of the emission light amount of the first light emission unit 43C corresponding to the second imaging unit 43 of product name B and the emission light amount of the second light emission unit 43D.

[0084] In the table data, the separation distance corresponding to the second imaging unit 43 of product name B is set to be larger than the separation distance corresponding to the second imaging unit 43 of product name A. Thus, when the second imaging unit 43 provided in the image forming apparatus 100 is the second imaging unit 43 of product name B (where it is relatively difficult to read the shadow SH1), it is possible to increase the separation distance to widen the width W1 of the shadow SH1.

[0085] For example, the adjustment processing unit 52 adjusts the light amount ratio and the separation distance based on the identification result by the identification processing unit 51 and the table data. That is, the adjustment processing unit 52 adjusts the emission light amount of the first light emission unit 43C to the light amount associated with the identification result by the identification processing unit 51 in the table data. Also, the adjustment processing unit 52 adjusts the emission light amount of the second light emission unit 43D to the light amount associated with the identification result by the identification processing unit 51 in the table data. Further, the adjustment processing unit 52 uses the moving unit 46 to move the shading roller 45 so that the separation distance becomes the distance associated with the identification result by the identification processing unit 51 in the table data.

[0086] Note that the adjustment processing unit 52 may adjust only the light amount ratio among the light amount ratio and the separation distance. In this case, the image reading unit 2 may not include the moving unit 46. Also, the adjustment processing unit 52 may adjust only the separation distance among the light amount ratio and the separation distance. In this case, the second imaging unit 43 may not include the second light emission unit 43D.

[0087] [Reading Condition Adjustment Processing] Hereinafter, with reference to FIG. 4, an example of the procedure of the reading condition adjustment process executed by the control unit 7 in the image forming apparatus 100 will be described together with the reading condition adjustment method of the present invention. Here, steps S11, S12,... represent the numbers of the processing procedures (steps) executed by the control unit 7. For example, the reading condition adjustment process is executed when the power of the image forming apparatus 100 is turned on. Further, the reading condition adjustment process may be executed when a predetermined operation is received on the operation display unit 5.

[0088] <Step S11> First, in step S11, the control unit 7 identifies the type of the second imaging unit 43. The process of step S11 is an example of the identification step of the present invention and is executed by the identification processing unit 51 of the control unit 7.

[0089] Specifically, the control unit 7 identifies whether the second imaging unit 43 provided in the image forming apparatus 100 is the second imaging unit 43 of product name A or the second imaging unit 43 of product name B based on the type signal output from the image processing unit 44.

[0090] <Step S12> In step S12, the control unit 7 adjusts the specific conditions based on the identification result of the process in step S11. The process of step S12 is an example of the adjustment step of the present invention and is executed by the adjustment processing unit 52 of the control unit 7.

[0091] Specifically, the control unit 7 adjusts the light amount ratio and the separation distance based on the identification result of the process in step S11 and the table data.

[0092] In this way, in the image forming apparatus 100, the type of the second imaging unit 43 is identified, and the specific conditions are adjusted based on the identification result of the type. Thereby, it is possible to adjust the specific conditions related to the generation of the shadow SH1 (see FIG. 3) according to the type of the second imaging unit 43 provided in the image forming apparatus 100. Therefore, regardless of the type of the second imaging unit 43, it is possible to read the shadow SH1 generated at the leading edge of the document X1.

[0093] [Supplementary Note of the Invention] Hereinafter, the outline of the invention extracted from the above-described embodiment will be appended. Note that each configuration and each processing function described in the following supplementary note can be arbitrarily combined by making selections.

[0094] <Supplementary Note 1> A document conveyance unit that conveys a document along a predetermined conveyance path, and a first light emitting unit that emits light from the upstream side in the conveyance direction of the document to the reading position at a predetermined reading position in the conveyance path, and outputs image data including an image of the document passing through the reading position using the first light emitting unit, an identification processing unit that identifies the type of the image sensor, and an adjustment processing unit that adjusts specific conditions related to the generation of a shadow that occurs when the leading edge of the document passes through the reading position among the reading conditions of the image of the document using the image sensor, based on the identification result by the identification processing unit. An image reading apparatus comprising:

[0095] <Supplementary Note 2> An image processing unit that executes predetermined image processing on the image data output from the image sensor, the image processing unit can output a type signal corresponding to the type of the image sensor, and the identification processing unit identifies the type of the image sensor based on the type signal output from the image processing unit. The image reading apparatus according to Supplementary Note 1.

[0096] <Supplementary Note 3> The image sensor has a second light emitting unit that emits light from a downstream side of the reading position in the conveyance direction toward the reading position, outputs the image data using the first light emitting unit and the second light emitting unit, and the specific condition includes a light quantity ratio between the light quantity of the light emitted by the first light emitting unit and the light quantity of the light emitted by the second light emitting unit. The image reading apparatus according to Appendix 1 or 2.

[0097] <Appendix 4> The image reading apparatus includes an opposing unit provided to face the image sensor with the reading position therebetween, and a moving unit that moves the opposing unit along the direction of facing the image sensor, and the specific condition includes the separation distance between the image sensor and the opposing unit. The image reading apparatus according to any one of Appendices 1 to 3.

[0098] <Appendix 5> An image forming apparatus including the image reading apparatus according to any one of Appendices 1 to 4, and forming an image on a sheet based on the image data output from the image reading apparatus.

[0099] <Appendix 6> A reading condition adjustment method executed by an image reading apparatus including a document conveyance unit that conveys a document along a predetermined conveyance path, and an image sensor that has a first light emitting unit that emits light from an upstream side of the conveyance direction of the document toward the reading position at a predetermined reading position in the conveyance path, and outputs image data including an image of the document passing through the reading position using the first light emitting unit, the method including an identification step of identifying the type of the image sensor, and an adjustment step of adjusting a specific condition related to generation of a shadow that occurs when a leading end of the document passes through the reading position among the reading conditions of the image of the document using the image sensor based on the identification result of the identification step.

Explanation of Signs

[0100] 1 ADF 2 Image reading unit 3 Image forming unit 4 Sheet feeding unit 5 Operation display unit 6 Memory unit 7 Control unit 21 Original document placement unit 22 Housing 22A Conveyor path 23 Pickup roller 24 Paper feed belt 25 Separation roller 26 Registration roller 27 First conveyor roller 28 Second conveyor roller 29 Discharge roller 30 Discharge unit 43 Second imaging unit 43A Housing 43B Light-transmitting part 43C First light-emitting part 43D Second light-emitting part 43E Lens 43F Photoelectric conversion part 43G AFE 44 Image processing unit 45 Shading roller 46 Moving part 51 Identification processing unit 52 Adjustment processing unit 100 Image forming apparatus

Claims

1. A document conveyance unit that conveys a document along a predetermined conveyance path, a first light emitting unit that emits light from an upstream side in the conveyance direction of the document toward a predetermined reading position in the conveyance path, and an image sensor that outputs image data including an image of the document passing through the reading position using the first light emitting unit, an identification processing unit that identifies the type of the image sensor, an adjustment processing unit that adjusts specific conditions related to the generation of a shadow that occurs when the leading edge of the document passes through the reading position among the reading conditions of the image of the document using the image sensor based on the identification result by the identification processing unit, An image reading apparatus comprising the same.

2. An image processing unit that performs predetermined image processing on the image data output from the image sensor is provided, the image processing unit can output a type signal corresponding to the type of the image sensor, the identification processing unit identifies the type of the image sensor based on the type signal output from the image processing unit, The image reading apparatus according to Claim 1.

3. The image sensor has a second light emitting unit that emits light from a downstream side in the conveyance direction of the document toward the reading position, and outputs the image data using the first light emitting unit and the second light emitting unit, the specific conditions include a light quantity ratio of the light quantity of the light emitted by the first light emitting unit and the light quantity of the light emitted by the second light emitting unit, The image reading apparatus according to Claim 1.

4. An opposing unit provided to face the image sensor with the reading position therebetween, a moving unit that moves the opposing unit along the opposing direction with the image sensor, Comprising, the specific conditions include the separation distance between the image sensor and the opposing unit, The image reading apparatus according to Claim 1.

5. Comprising the image reading apparatus according to any one of Claims 1 to 4, forming an image on a sheet based on the image data output from the image reading apparatus, An image forming apparatus.

6. A document conveyance unit that conveys a document along a predetermined conveyance path, and a first light emitting unit that emits light from an upstream side in the conveyance direction of the document toward a reading position at a predetermined position in the conveyance path, and an image sensor that outputs image data including an image of the document passing through the reading position using the first light emitting unit. A reading condition adjustment method executed by an image reading apparatus comprising: An identification step of identifying the type of the image sensor; An adjustment step of adjusting specific conditions related to the generation of a shadow that occurs when the leading edge of the document passes through the reading position among the reading conditions of the image of the document using the image sensor based on the identification result of the identification step; A reading condition adjustment method including the above.

Images