JP2016213686A - Image reader, image forming apparatus and image reading method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict adhesion of dust and so on to a surface of a document, which surface is to be read.SOLUTION: In a digital copying device 1, an image reading part that reads an image of a document is disposed below a pressure plate part 5, and a document is inserted between the pressure plate part 5 and the image reading part. Using a carrying part, the digital copying device 1 carries an inserted document into the image reading part. However, a document table roller part 12 is disposed in the position of the upstream end part of a document table 11 in the direction in which a document is carried. If a document is a long-sized one, the digital copying device 1 moves the document table roller part 12 to a separate position in a higher position. While separating a surface of the document, which side is to be read, from the document table 11 by use of the document table roller part 12, the digital copying device carries the document between the pressure plate part and the image reading part, thereby restricting adhesion of dust and so on to the reading part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image reading apparatus, an image forming apparatus, and an image reading method, and more particularly to an image reading apparatus, an image forming apparatus, and an image reading method for reading an image of a document.

  As an image reading apparatus that automatically reads an image of an original, there are roughly two methods as an original reading method. That is, first, the original is transported one by one from the original table onto the contact glass by the original transport mechanism, stopped on the contact glass, and the scanning optical system mounted on the moving carriage is moved in the sub-scanning direction. There is a document stationary type reading system that scans an image of a document while performing main scanning. Next, there is an original conveyance type reading method in which an original is scanned by a stationary scanning optical system while an original is conveyed by a document conveying mechanism on a contact glass from an original table, and an image of the original is read.

  Normally, in any reading method, an image reading apparatus conveys a document onto a contact glass while being guided by a document table, and reads an image of the document on the contact glass with a scanning optical system.

  Such an image reading apparatus conveys a document onto the contact glass while guiding the document in contact with the document table with its image reading surface facing the document table. Therefore, while the document is conveyed on the document table, the document comes into contact with the document table, and dirt such as image forming agent such as dust and ink (hereinafter referred to as dust) adheres to the image reading surface of the document. . As a result, dust or the like appears not only as a dust image in the read image but also as an abnormal image such as a white stripe or a black stripe when attached to the scanning optical system.

  Conventionally, a means for converting an image of a document into a density signal using an image reading means, a conversion means for converting the density signal converted by the conversion means into a digital image signal, and a digital signal converted by the conversion means In a digital copying machine comprising an image creating means for writing an image signal on a photosensitive member, a conveying means for conveying a sheet-like document, a plurality of image reading means for reading a document being conveyed, and an output from the image reading means A digital device comprising: conversion means for converting a signal into a digital image signal; delay means for delaying an output signal from the conversion means; comparison means for comparing a plurality of digital image signals; and detection means for detecting image noise A copying machine has been proposed (see Patent Document 1).

  That is, in this prior art, an image of a document being conveyed is read sequentially by a plurality of image reading means, and if there is a difference between the read images, it is detected as image noise. Then, image noise is removed from the image data.

  However, in the above prior art, since dust and the like are only removed by image processing, it is impossible to prevent dust and the like from adhering to the reading surface of the document, and the influence of dust and the like is removed. There are times when it cannot be done. As a result, it has been necessary to improve the image quality by preventing the original image from being processed as noise and improving the image quality.

  Accordingly, an object of the present invention is to suppress adhesion of dust or the like to a reading surface of a document.

  In order to achieve the above object, an image reading apparatus according to claim 1, an image reading unit that reads an image of a document, a transport unit that transports the document to the image reading unit, and the image reading unit by the transport unit. Opposite the reading surface of the original conveyed to the guide, the guide means for guiding the original to be conveyed, and the vicinity of the upstream end portion of the guide means in the original conveying direction, and conveyed by the conveying means And a separating unit that separates the reading surface of the document by a predetermined amount from the guide unit in the vicinity of the upstream end portion of the guide unit in the document transport direction.

  According to the present invention, it is possible to suppress adhesion of dust or the like to the reading surface of a document.

1 is an external perspective view of a digital copying apparatus to which an embodiment of the present invention is applied. FIG. 4 is a top perspective view of a document insertion unit and a conveyance reading unit. FIG. 3 is an enlarged schematic configuration diagram of a document insertion unit, a conveyance reading unit, and a pressure plate unit. FIG. 3 is a partially enlarged front view of a document table roller unit. FIG. 5 is a side configuration diagram of a document insertion unit, a conveyance reading unit, and a pressure plate unit when a document table roller unit is in a standby position. FIG. 3 is a side configuration diagram of a document insertion unit, a conveyance reading unit, and a pressure plate unit when a document is inserted. The enlarged side view of the front-end | tip part of an original table. FIG. 4 is a side configuration diagram of a document insertion unit, a conveyance reading unit, and a pressure plate unit when a document table roller unit is at a separation position. 1 is a block diagram of a digital copying apparatus. 1 is a functional block diagram of a digital copying apparatus. The figure which shows an example of a document table roller part drive condition. 5 is a flowchart showing image reading control processing.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The range of this invention is unduly limited by the following description. However, not all the configurations described in the present embodiment are essential constituent elements of the present invention.

  1 to 12 are diagrams illustrating an embodiment of an image reading apparatus, an image forming apparatus, and an image reading method according to the present invention. FIG. 1 illustrates an image reading apparatus, an image forming apparatus, and an image reading method according to the present invention. 1 is an external perspective view of a digital copying apparatus 1 to which an embodiment is applied.

  In FIG. 1, a digital copying apparatus (image reading apparatus, image forming apparatus) 1 is provided with a document insertion portion 3 and a paper discharge portion 4 on the front side of a main body housing 2, and a pressure plate above the main body housing 2. A unit 5 and an operation unit 6 are provided. Further, as shown in FIG. 2, the digital copying apparatus 1 is provided with a conveyance reading unit 7 that is continuous with the document insertion unit 3.

  The operation unit 6 includes an operation key 6a, an operation panel 6b, and the like. The operation key 6a is a physical key, and various operations such as a copying operation, a printing operation, and a scanner operation using the digital copying apparatus 1 and various operations in an image reading method described later are performed. For example, a display such as an LCD (Liquid Crystal Display) or a display with a touch panel is used as the operation panel 6b, and the contents of commands input from the operation keys 6a and various information notified to the user from the digital copying apparatus 1 are displayed. The When a display with a touch panel is used, the operation panel 6b displays various function buttons together with various information, and detects a touch operation on the function buttons. In particular, the operation unit 6 is used to input the length in the conveyance direction of the original G by a key operation of the operation key 6a or a touch operation of the touch panel of the operation panel 6b. Therefore, the operation unit 6 functions as an input unit.

  In the digital copying apparatus 1, a printer unit 52 (see FIG. 9), which will be described later, is housed in the main body housing 2, and printing is performed on the paper by the printer unit 52 and the printed paper is discharged to the paper discharge unit 4. .

  As shown in FIGS. 2 and 3, the document insertion unit 3 includes a document table 11, a document table roller unit 12, a support member 13, and the like.

  In the digital copying apparatus 1, a document G is inserted from the document insertion unit 3 to the pressure plate unit 5 with the direction of the pressure plate unit 5 from the document table roller unit 12 of the document insertion unit 3 as the transport direction (insertion direction).

  The document table roller unit 12 is attached to the document table 11 by a support member 13. The document table roller unit 12 is configured so that the support member 13 rotates a predetermined amount in the vertical direction around the mounting position on the document table 11, so that the separation position Pr (see FIGS. 3 and 8) and the document G are not in contact with each other. It is supported so as to be movable with respect to the document table 11 at a standby position Pt (see FIGS. 5 and 6).

  The document table 11 has a predetermined length in the transport direction and a width wider than the maximum document width that can be read by the digital copying apparatus 1 in the width direction orthogonal to the transport direction. The original G to be inserted is set with the original table 11 side as the reading surface. As shown in FIG. 7, the document table 11 has a leading end formed in a curved surface that smoothly guides the reading surface of the document G to be inserted into the pressure plate portion 5, and an upper end surface of the document table 11 toward the pressure plate portion 5. It is formed on a plane that guides the reading surface of the original G to be inserted.

  The support member 13 is rotatably attached to both side surfaces in the width direction of the document table 11 by a fulcrum part 13a, and the outer peripheral surface of the fulcrum part 13a has a gear structure. The support member 13 has a document table roller shaft 12 a attached to the tip of each support member 13.

  The document table roller section (roller) 12 has a document table roller (small roller) 12b rotatably attached to a document table roller shaft 12a. As shown in FIGS. 2 and 4, a plurality of document table rollers 12b are arranged at predetermined intervals in the axial direction of the document table roller shaft 12a. The document table roller 12b is attached to the document table roller shaft 12a so as to be rotatable with a light load as the document G touches the document table roller 12b and moves in the transport direction.

  In the document table 11, an operation motor 14 is disposed in the vicinity of the position where the fulcrum portion 13 a of the support member 13 is disposed, and the drive shaft of the operation motor 14 extends to both side surfaces of the document table 11 in the width direction. . A drive gear 14 a is attached to both ends of the drive shaft of the operation motor 14. The drive gear 14 a is connected to the fulcrum part 13 a by the timing belt 15, and the fulcrum part 13 a is rotated via the timing belt 15 when the drive gear 14 a is rotated by the operation motor 14.

  The support member 13 rotates the fulcrum portion 13a to move the document table roller portion 12 as the tip portion in the vertical direction to the separation position Pr and the standby position Pt around the fulcrum portion 13a.

  The document table 11 is provided with a limit sensor 16, a document insertion sensor 17, and a long document sensor 18.

  The limit sensor 16 is a mechanical switch or an optical sensor. The limit sensor 16 is turned on when the support member 13 is moved up to the separation position Pr of the document table roller section 12, and is turned off when the support member 13 is moved from the separation position Pr to the standby position Pt by a predetermined amount. That is, the limit sensor 16 is turned on by detecting that the support member 13 has moved to the separation position Pr, and is turned off by detecting that the support member 13 has moved from the separation position Pr to the standby position Pt by a predetermined amount.

  For example, a reflection type optical sensor or the like is used as the document insertion sensor 17. When the document G is inserted into the pressure plate unit 5 along the document table 11, the document G is detected and an ON inserted document detection signal is output. Output.

  The long document sensor (document detection means) 18 is, for example, a reflective optical sensor, and detects the back side in the transport direction of the document G inserted into the pressure plate unit 5 and outputs an ON long document detection signal. Output.

  3, 5, 6, and 8, the conveyance reading unit 7 includes a contact glass 21, an image reading sensor unit 22, a front conveyance roller 23, a rear conveyance roller 24, and the like. The unit 5 includes a pressure plate 31, a front driven roller 32, a rear driven roller 33, and the like. The pressure plate portion 5 is attached to the main body housing 2 so as to be rotatable about one side, for example, the rear side, and can open and close the surface of the contact glass 21.

  The conveyance reading unit 7 is provided with an image reading sensor unit 22 below a transparent contact glass 21. A front conveyance roller 23 conveys the document G upstream of the image reading sensor unit 22 in the conveyance direction. A rear conveying roller 24 is disposed on the downstream side in the direction.

  In the pressure plate unit 5 and the conveyance reading unit 7, the pressure plate 31 is positioned on the contact glass 21 with the pressure plate unit 5 closed, and the front conveyance roller 23, the front driven roller 32, the rear conveyance roller 24, and the rear driven roller 33. Are disposed in contact with each other at a predetermined pressure.

  The pressure plate unit 5 and the conveyance reading unit 7 are configured to read the original G in which the front conveyance roller 23 and the front driven roller 32 are inserted between the pressure plate unit 5 and the conveyance reading unit 7 along the document table 11. To 22.

  In the conveyance reading unit 7, the image reading sensor unit 22 reads an image of the surface on the contact glass 21 side of the document G conveyed on the contact glass 21. For example, an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device) is used as the image reading sensor unit 22, and reads an image of the document G conveyed on the contact glass 21. Further, the image reading sensor unit 22 reads the surface of the pressure plate 31 on the side of the contact glass 21 before the document G is conveyed onto the contact glass 21, and acquires white reference data. That is, the pressure plate 31 has a white surface on the side of the contact glass 21 and provides reference data for detecting light quantity fluctuations.

  In the pressure plate unit 5 and the conveyance reading unit 7, the rear conveyance roller 24 and the rear driven roller 33 convey the original G whose image has been read by the image reading sensor unit 22 to an original discharge unit (not shown).

  The digital copying apparatus 1 has a block configuration as shown in FIG. That is, the digital copying apparatus 1 includes a system control unit 41, a document conveyance driving unit 42, a document conveyance motor 43, a document table roller driving unit 44, a document registration sensor 45, a document discharge sensor 46, a document size sensor 47, and an image processing control unit. 48, data storage unit 49, external I / F 50, printer control unit 51, printer unit 52 and operation unit 6, operation key 6a, operation panel 6b, operation motor 14, limit sensor 16, document insertion sensor 17, long document The sensor 18 and the image reading sensor unit 22 are provided.

  The system control unit 41 includes a CPU (Central Processing Unit) 61, a ROM (Read Only Memory) 62, a RAM (Random Access Memory) 63, and the like.

  The ROM 62 stores a basic program as the digital copying apparatus 1, a program for executing the image reading method of the present invention, necessary system data, data used in the image reading method of the present invention, and the like. The RAM 63 is used as a work memory for the CPU 61.

  The CPU 61 uses the RAM 63 as a work memory based on a program in the ROM 62 to control each unit of the digital copying apparatus 1 to execute basic processing as the digital copying apparatus 1 and to perform the image reading method of the present invention. Execute.

  The document conveyance drive unit 42 is connected to the system control unit 41 and the document conveyance motor 43 and includes a driver circuit. The document transport motor 43 rotates the front transport roller 23 and the rear transport roller 24 to transport the document G. The document transport driving unit 42 drives the document transport motor 43 based on a drive signal from the system control unit 41 and rotates the front transport roller 23 and the rear transport roller 24 to transport the document G.

  The document table roller driving unit 44 is connected to the system control unit 41 and the operation motor 14 and includes a driver circuit. The document table roller drive unit 44 controls driving of the operation motor based on the roller drive signal from the system control unit 41, and separates the document table roller unit 12 from the standby position Pt via the timing belt 15 and the support member 13. Move to position Pr.

  As described above, the limit sensor 16 detects the support member 13 when the document table roller unit 12 moves to the standby position Pt, and outputs a limit signal to the system control unit 41. Based on the limit signal from the limit sensor 16, the system control unit 41 controls the rotation of the operation motor 14 in the direction of the separation position Pr via the document table roller driving unit 44.

  As described above, the document insertion sensor 17 detects whether or not the document G is inserted between the front transport roller 23 and the front driven roller 32 and outputs an inserted document detection signal to the system control unit 41. The system control unit 41 determines whether or not the document G is inserted based on the inserted document detection signal from the document insertion sensor 17.

  The document registration sensor 45 uses, for example, a reflection type optical sensor, detects the presence or absence of the document G at the reading start position of the image reading sensor unit 22, and outputs a registration signal to the system control unit 41. The system control unit 41 controls reading of the document G by the image reading sensor unit 22 based on the registration signal.

  For example, a reflection type optical sensor or the like is used as the document discharge sensor 46. The document discharge sensor 46 is disposed downstream of the image reading sensor unit 22 in the document transport direction, and a document G that has been read by the image reading sensor unit 22 is predetermined. It is detected whether or not it has been discharged to a position, and a discharge detection signal is output to the system control unit 41. The system control unit 41 controls the discharge operation of the document G based on the discharge detection signal.

  As described above, the long document sensor 18 detects the presence or absence of the document G at the upstream end position in the conveyance direction of the document table 11 and outputs a long document detection signal to the system control unit 41. Based on the long document detection signal from the long document sensor 18 when the document insertion sensor 17 detects the insertion of the document G, the system control unit 41 detects that the set document G is longer than a predetermined length. It is determined whether or not it is a document G.

  For example, a reflection type optical sensor or the like is used as the document size sensor 47, and a plurality of document size sensors 47 are arranged at predetermined intervals in the width direction of the document table 11. The document size sensor 47 detects the width size of the document G set on the document table 11 and outputs it to the system control unit 41.

  As described above, the image reading sensor unit 22 scans the reading surface of the document G, reads an image of the document G, and outputs analog image data to the image processing control unit 48.

  The image processing control unit 48 converts the analog image data from the image reading sensor unit 22 into digital data, and then applies digital image data to the digital image data according to the setting in the operation unit 6 or the setting from the external information processing apparatus. The image is subjected to various image processing and output to the data storage unit 49.

  The data storage unit 49 is configured by a hard disk or the like, stores image data image-processed by the image processing control unit 48 under the control of the system control unit 41, and reads it out as necessary.

  The external I / F 50 is connected to an information processing apparatus or the like via a network (not shown) or the like, and exchanges data with the information processing apparatus under the control of the system control unit 41. In particular, the external I / F 50 transmits the image data stored in the data storage unit 49 to the information processing apparatus.

  The printer control unit 51 is connected to the system control unit 41 and the printer unit 52, and controls the drive of the printer unit 52 based on the drawing data and the operation control signal sent from the system control unit 41 to The image is formed (printed) on the part 52.

  As the printer unit 52, printers of various image forming methods such as an ink jet method and an electrophotographic method can be applied. Under the control of the printer control unit 51, an image is formed on a sheet and the image has been formed (printed). ) Is discharged to the paper discharge unit 4.

  The digital copying apparatus 1 includes ROM, EEPROM (Electrically Erasable and Programmable Read Only Memory), EPROM, flash memory, flexible disk, CD-ROM (Compact Disc Read Only Memory), CD-RW (Compact Disc Rewritable), DVD (Digital Program for executing the image reading method of the present invention recorded on a computer-readable recording medium such as Versatile Disk (USB), Universal Serial Bus (USB) memory, Secure Digital (SD) card, MO (Magneto-Optical Disc) Is read and introduced into the ROM 62 and the like, and is constructed as an image reading apparatus that executes an image reading method that suppresses adhesion of dust and the like to the reading surface of the original G, which will be described later, and an image forming apparatus that includes the image reading apparatus. ing. A program for executing this image reading method is a computer-executable program described in a legacy programming language such as an assembler, C, C ++, C #, Java (registered trademark), an object-oriented programming language, or the like, and the recording medium Can be stored and distributed.

  In the digital copying apparatus 1, a function block as shown in FIG. 10 is constructed by introducing a program for executing the image reading method. That is, when a program for executing an image reading method is introduced, the digital copying apparatus 1 has an image reading unit 101, a conveyance unit 102, a guide unit 103, a separation unit 104, a drive control unit 105, and a drive control unit 105 as shown in FIG. The length determination unit 106 and the like are constructed.

  The image reading unit 101 is constructed by the image reading sensor unit 22 and reads an image of the document G. Therefore, the image reading unit 101 functions as an image reading unit.

  The conveyance unit 102 is constructed by a front conveyance roller 23, a rear conveyance roller 24, a front driven roller 32, a rear driven roller 33, a document conveyance driving unit 42, a document conveyance motor 43, and the like. The conveyance unit 102 conveys the inserted document G to the image reading unit 101 and functions as a conveyance unit.

  The guide unit 103 is constructed by the document table 11, the contact glass 21, and the like, and guides the document G to be conveyed so as to face the reading surface of the document G conveyed to the image reading unit 101 by the conveyance unit 102. . Therefore, the guide part 103 functions as a guide means.

  The separation unit 104 is constructed by the support member 13, the document table roller unit 12, and the like. The separation unit 104 is disposed in the vicinity of the upstream end of the guide unit 103 in the document conveyance direction, and separates the reading surface of the document G conveyed by the conveyance unit 102 from the guide unit 103 by a predetermined amount. Therefore, the separation part 104 functions as a separation means.

  The length determination unit 106 is constructed by the long document sensor 18, the operation unit 6, the system control unit 41, and the like, and determines whether the conveyance direction length of the document G exceeds a predetermined threshold length. Therefore, the length determination unit 106 functions as a length determination unit.

  The drive control unit 105 includes a system control unit 41, a document table roller drive unit 44, and the like. When the length of the document G exceeds the threshold length, the drive control unit 105 drives the separation unit 104 in a direction to separate the reading surface of the document G from the guide unit 103 by a predetermined amount. Therefore, the drive control unit 105 functions as a drive control unit.

  Next, the operation of this embodiment will be described. The digital copying apparatus 1 of this embodiment suppresses the adhesion of dust or the like to the reading surface of the original G.

  When the digital copying apparatus 1 reads an image of the document G, when the user inserts the leading end portion of the document G between the front transport roller 23 and the front driven roller 32, the digital copy apparatus 1 moves the document G to the front transport roller 23 and the front transport roller 23. The contact roller 21 is conveyed by the driven roller 32. The digital copying apparatus 1 reads the image on the reading surface with the image reading sensor unit 22 using the surface on the contact glass 21 side of the original G conveyed on the contact glass 21 as a reading surface. When the leading edge of the original G advances to the rear conveying roller 24 and the rear driven roller 33, the digital copying apparatus 1 conveys the original G by the front conveying roller 23, the front driven roller 32, the rear conveying roller 24, and the rear driven roller 33. At the same time, the image reading sensor unit 22 reads the image of the document G.

  The digital copying apparatus 1 conveys the original G whose image has been read to the original discharge unit (not shown) by the rear conveying roller 24 and the rear driven roller 33.

  However, when the document G is long, the weight of the document G itself is large, and while the document G is conveyed to the front conveyance roller 23 and the front driven roller 32, the reading surface of the document G moves while contacting the document table 11. In addition, dust or the like may adhere to the reading surface of the original G. Even if the digital copying apparatus 1 has an image processing function for removing an image such as a smear adhering to the reading surface of the original G, not only all of them can be removed, but also dust or the like can be removed from the reading surface of the original G. It cannot prevent itself from being attached.

  Therefore, the digital copying apparatus 1 of the present embodiment executes the image reading control process shown in FIG. 12 based on the document table roller unit driving conditions as shown in FIG. The digital copying apparatus 1 executes the image reading control process so that the document table roller unit 12 is driven based on the document table roller unit driving condition so that the long document G is obtained from the document table 11. To prevent dust from adhering.

  The document table roller unit driving conditions shown in FIG. 11 are stored in advance in the ROM 62 or the like, and the roller ascending condition and the roller descending condition are registered. In the document table roller unit driving condition of FIG. 11, as the roller raising condition, the long document sensor 18 is ON (“sensor ON”), and the input document length from the operation unit 6 is a threshold value (“input document length> threshold value”. )), And at least one of them is registered. Further, in the document table roller unit driving condition of FIG. 11, the reading completion of the document G (“reading completion”) is registered as the roller lowering condition. When the roller ascending condition is satisfied, the digital copying apparatus 1 raises the document table roller unit 12 to the separation position Pr and separates the document G from the upper surface of the document table 11 by a predetermined amount as shown in FIG. Carry in the state. The digital copying apparatus 1 suppresses adhesion of dust or the like to the reading surface of the original G by conveying the original G in a state of being separated (floating) from the original table 11. Further, when the roller ascending condition is not satisfied, the digital copying apparatus 1 places the document G along the document table 11 with the document table roller unit 12 positioned at the standby position Pt as shown in FIG. Transport. When the document length is input from the operation unit 6, if the input document length exceeds a threshold (for example, 420 mm), the digital copying apparatus 1 determines that the roller raising condition is satisfied, and is less than the threshold. If it is, it is determined that the roller ascent condition is not satisfied.

  That is, as shown in FIG. 12, in the digital copying apparatus 1, when the power is turned on, the document insertion sensor 17 is turned on, that is, the leading edge of the document G is the front conveyance roller 23 and the front driven roller 32. It is checked whether it has been inserted between them (step S101).

  If the document insertion sensor 17 is OFF in step S101 (NO in step S101), the digital copying apparatus 1 determines that the document reading mode is not set, and whether the document insertion sensor 17 is ON again. Is checked (step S101).

  When the long document G is released from the long document G after the front end portion is held between the front conveying roller 23 and the front driven roller 32 by the user, as shown in FIG. As a result, it hangs smoothly from the front end of the document table 11. In this state, when the document table roller unit 12 is positioned at the standby position Pt, the long document G is hung from the position on the front end side of the document table 11 relative to the document table roller unit 12 as shown in FIG. It becomes. Therefore, in this state, the long document sensor 18 detects the document G and is turned ON, and outputs an ON long document detection signal.

  If the document insertion sensor 17 is ON in step S101 (YES in step S101), the digital copying apparatus 1 determines that the document G has been inserted and starts driving the front conveying roller 23 (step S101). S102). When the digital copying apparatus 1 starts driving the front conveying roller 23 and starts conveying the original G, the digital copying apparatus 1 conveys the original G until a predetermined time has elapsed (step S103). In other words, the digital copying apparatus 1 conveys the document G by a distance where the leading edge of the document G is reliably sandwiched between the front conveyance roller 23 and the front driven roller 32.

  When the digital copying apparatus 1 transports the document G for a predetermined time, the transport of the document G is temporarily stopped (step S104), and satisfies the roller raising condition for raising the document table roller unit 12 among the document table roller unit driving conditions. Is checked (step S105).

  If the roller raising condition is not satisfied in step S105 (NO in step S105), the digital copying apparatus 1 starts conveying the original G and reads the original G (step S106). In this case, the digital copying apparatus 1 starts transporting the document G and reads the document G in a state where the document table roller unit 12 is positioned at the standby position Pt without being raised.

  In step S105, if the roller ascent condition is satisfied (YES in step S1205), the digital copying apparatus 1 starts the ascending drive of the operation motor 14 (drives the document table roller unit 12 in the ascending direction). (Step S107). The digital copying apparatus 1 checks whether the detection signal from the limit sensor 16 has been turned on when the upward driving of the operation motor 14 is started (step S108). At this time, the digital copying apparatus 1 drives the operation motor 14 up until the support member 13, that is, the document table roller unit 12, is raised to the separation position Pr (steps S107 and S108).

  In step S108, the digital copying apparatus 1 raises the document table roller unit 12 to the separation position Pr (YES in step S108), and stops driving the operation motor 14 (step S109). When the operation motor 14 is stopped, the digital copying apparatus 1 starts transporting the document G in a state where the document G is lifted from the document table 11 by the document table roller unit 12 at the separation position Pr (separated). Then, the original G is read (step S106). Therefore, since the reading surface of the document G is floating from the document table 11, adhesion of dust or the like to the reading surface of the document G can be suppressed.

  At this time, as shown in FIGS. 2 and 4, the document table roller unit 12 is provided with a plurality of document table rollers 12b at predetermined intervals in the axial direction of the document table roller shaft 12a. The document table roller 12b is attached to the document table roller shaft 12a so as to be rotatable with a light load as the document G touches the document table roller 12b and moves in the transport direction. Therefore, the document table roller unit 12 can be transported to the front transport roller 23 and the front driven roller 32 while being lifted from the document table 11 without adhering dust or the like to the reading surface of the document G. In addition, since the document table roller unit 12 is divided into a plurality of document table rollers 12b, the load when rotating due to the friction of the document G can be reduced, and a moderately balanced tension according to the document width can be obtained. You can hang it.

  The digital copying apparatus 1 checks whether the reading of the original G is completed and the roller lowering condition is satisfied (step S110).

  If the roller lowering condition is not satisfied in step S110 (NO in step S110), the digital copying apparatus 1 continues to convey the original G and read the image. If the roller lowering condition is satisfied in step S110 (YES in step S110), the digital copying apparatus 1 checks whether or not the document table roller unit 12 has been raised (step S111).

  If the document table roller unit 12 has not been raised in step S111 (NO in step S111), the digital copying apparatus 1 ends the image reading control process, returns to step S101, and performs the same processing as described above. (Steps S101 to S111).

  If the document table roller unit 12 has been raised in step S111 (YES in step S111), the digital copying apparatus 1 drives the operation motor 14 downward (drives the document table roller unit 12 downward). Is started (step S112).

  When the operation motor 14 also starts to descend, the digital copying apparatus 1 waits for the document table roller unit 12 to descend to the standby position Pt after a predetermined time has elapsed (step S113), and stops the operation motor 14 (step S113). Step S114). When the document table roller unit 12 is lowered to the standby position Pt and the operation motor 14 is stopped, the digital copying apparatus 1 ends the image reading control process, returns to step S101, and performs the same processing as above (steps S101 to S101). S114).

  As described above, the digital copying apparatus 1 according to the present exemplary embodiment includes an image reading unit (image reading unit) 101 that reads an image of the original G, and a conveyance unit (conveying unit) 102 that conveys the original G to the image reading unit 101. A guide unit (guide means) 103 for guiding the document G to be transported facing the reading surface of the document G transported to the image reading unit 101 by the transport unit 102; The guide unit is disposed near the upstream end of the document transport direction, and the guide surface of the guide G is transported by the transport unit 102 near the upstream end of the guide unit 103 in the document transport direction. And a separation portion (separation means) 104 that separates a predetermined amount from 103.

  Therefore, the reading surface of the document G can be conveyed with a predetermined distance from the document table 11 of the guide unit 103, and adhesion of dust or the like to the reading surface of the document G can be suppressed. As a result, the image quality of the read image can be improved.

  In addition, the digital copying apparatus 1 of the present embodiment includes a length determination unit (length determination unit) 106 that determines whether the length of the document G in the transport direction exceeds a predetermined threshold length, and the document G A drive control unit (drive control unit) 105 that drives the separation unit 104 in a direction in which the reading surface of the document G is separated from the guide unit 103 by a predetermined amount when the length exceeds the threshold length; , Is further provided.

  Therefore, when the conveyance direction length of the document G exceeds a predetermined threshold length, the document G reading surface can be conveyed with a predetermined amount away from the document table 11 of the guide unit 103. It is possible to suppress adhesion of dust or the like to the reading surface of the original G while improving the performance. As a result, the image quality of the read image can be improved while improving the usability.

  Further, in the digital copying apparatus 1 according to the present embodiment, the drive control unit 105 includes the separation position Pr for separating the document G from the guide unit 103 and the standby position Pt that is not in contact with the document G. When the section 104 is moved and the length of the original G exceeds the threshold length, the separation section 104 is moved from the standby position Pt to the separation position Pr.

  Accordingly, when the length of the document G in the transport direction exceeds a predetermined threshold length, the document G is automatically transported in a state in which the reading surface of the document G is separated from the document table 11 of the guide unit 103 by a predetermined amount. It is possible to suppress dust and the like from adhering to the reading surface of the original G while further improving the usability. As a result, the image quality of the read image can be improved while further improving the usability.

  Further, in the digital copying apparatus 1 of this embodiment, the separation unit 104 extends for a predetermined length in the width direction orthogonal to the transport direction, and rotates with the transport of the document G. Roller) 12.

  Accordingly, the reading surface of the document G can be conveyed with a predetermined amount away from the document table 11 of the guide unit 103 in a state where the load applied to the document G is small, and dust or the like adheres to the reading surface of the document G. Can be more appropriately suppressed. As a result, the image quality of the read image can be further improved.

  Further, in the digital copying apparatus 1 according to the present embodiment, the separation unit 104 is provided with a plurality of document table rollers (small rollers) 12b in which the document table roller unit (roller) 12 can rotate independently in the width direction. It is divided.

  Accordingly, the reading surface of the document G can be transported with a predetermined amount away from the document table 11 of the guide unit 103 in a state where the load applied to the document G is further reduced, and dust or the like on the reading surface of the document G Can be more appropriately suppressed. As a result, the image quality of the read image can be further improved.

  Further, in the digital copying apparatus 1 of the present embodiment, the length determination unit 106 is disposed at a predetermined position on the upstream side in the conveyance direction of the original G, and detects a long original sensor (original Detection means) 18, and based on the presence or absence of the original G by the long original sensor 18, it is determined whether or not the length of the original G exceeds the threshold length.

  Therefore, it is automatically determined whether or not the length of the document G in the transport direction exceeds a predetermined threshold length, and the reading surface of the document G is automatically separated from the document table 11 of the guide unit 103 by a predetermined amount. Therefore, it is possible to suppress the adhesion of dust or the like to the reading surface of the original G while further improving the usability. As a result, the image quality of the read image can be improved while further improving the usability.

  Further, in the digital copying apparatus 1 according to the present embodiment, the length determination unit 106 includes an operation unit (input unit) 6 to which the length of the document G is input, and the document input from the operation unit 6 It is determined whether the length of G exceeds the threshold length.

  Therefore, it is determined from the input document length whether or not the length in the conveyance direction of the document G exceeds a predetermined threshold length, and the guide surface of the document G is accurately and automatically determined. Therefore, it is possible to convey the dust G on the reading surface of the original G while improving the usability. As a result, the image quality of the read image can be improved while improving the usability.

  Further, the digital copying apparatus 1 of the present embodiment includes an image reading processing step in which an image reading unit (image reading unit) 101 reads an image of the original G, and a conveying unit (conveying unit) 102 that reads the original G in the image reading unit. The sheet is conveyed by a conveyance processing step for conveying to 101 and a guide unit (guide means) 103 disposed in a state facing the reading surface of the original G conveyed to the image reading unit 101 by the conveyance unit 102. The guide processing step for guiding the document G, and the accuracy portion (separating means) 104 disposed in the vicinity of the upstream end of the guide portion 103 in the document transport direction, the transported by the transport unit 102. A separation processing step of separating the reading surface of the document G from the guide unit 103 by a predetermined amount in the vicinity of the upstream end of the guide unit 103 in the document transport direction; A length determination processing step for determining whether the length of the document G in the conveyance direction exceeds a predetermined threshold length; and if the length of the document G exceeds the threshold length, the separation unit 104 is And a drive control processing step for driving the reading surface of the document G in a direction in which the reading surface is separated from the guide portion 103 by a predetermined amount.

  Therefore, the reading surface of the document G can be conveyed with a predetermined distance from the document table 11 of the guide unit 103, and adhesion of dust or the like to the reading surface of the document G can be suppressed. As a result, the image quality of the read image can be improved.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

DESCRIPTION OF SYMBOLS 1 Digital copying apparatus 2 Main body case 3 Document insertion part 4 Paper discharge part 5 Pressure plate part 6 Operation part 6a Operation key 6b Operation panel 7 Conveyance reading part 11 Document table 12 Document table roller part 12a Document table roller shaft 12b Document table roller 13 Support member 13a Support point part 14 Operation motor 14a Drive gear 15 Timing belt 16 Limit sensor 17 Document insertion sensor 18 Long document sensor 21 Contact glass 22 Image reading sensor unit 23 Front conveyance roller 24 Rear conveyance roller 31 Pressure plate 32 Front driven roller 33 Rear Followed roller 41 System control unit 42 Document conveyance drive unit 43 Document conveyance motor 44 Document table roller drive unit 45 Document registration sensor 46 Document discharge sensor 47 Document size sensor 48 Image processing control unit 49 Data storage unit 50 External I F
51 Printer Control Unit 52 Printer Unit 61 CPU
62 ROM
63 RAM
DESCRIPTION OF SYMBOLS 101 Image reading part 102 Conveyance part 103 Guide part 104 Separation part 105 Drive control part 106 Length judgment part G Document Pr Separation position Pt Standby position

JP-A-9-139844

Claims (9)

Image reading means for reading an image of a document;
Conveying means for conveying the document to the image reading means;
A guide unit for guiding the document to be conveyed opposite to the reading surface of the document conveyed to the image reading unit by the conveying unit;
The guide surface of the document is disposed near the upstream end of the guide unit in the document transport direction and is transported by the transport unit, and the guide surface is positioned near the upstream end of the guide unit in the document transport direction. A separating means for separating a predetermined amount from the means;
An image reading apparatus comprising: The image reading device includes:
Length determination means for determining whether the length of the document in the transport direction exceeds a predetermined threshold length;
Drive control means for driving the separation means in a direction to separate the reading surface of the document by a predetermined amount from the guide means when the length of the document exceeds the threshold length;
The image reading apparatus according to claim 1, further comprising: The drive control means includes
When the separation means is moved to a separation position where the document is separated from the guide means and a standby position where the document is not in contact with the document, and the length of the document exceeds the threshold length, the separation means The image reading apparatus according to claim 2, wherein the image reading apparatus is moved from the standby position to the separation position. The separation means is
4. The image reading apparatus according to claim 1, wherein the image reading apparatus is a roller that extends over a predetermined length in a width direction orthogonal to the conveyance direction and rotates as the document is conveyed. 5. . The separation means is
5. The image reading apparatus according to claim 4, wherein the roller is divided into a plurality of small rollers that can rotate independently in the width direction. The length judging means is
An original detection unit disposed at a predetermined position upstream in the conveyance direction of the original and detecting the presence or absence of the original;
6. The image reading according to claim 2, wherein whether or not the length of the document exceeds the threshold length is determined based on the presence or absence of the document by the document detection unit. apparatus. The length judging means is
An input means for inputting the length of the original;
7. The image reading apparatus according to claim 2, wherein it is determined whether or not the length of the document input from the input unit exceeds the threshold length. An image forming apparatus that forms an image of a document read by an image reading unit on a recording medium by an image forming unit,
An image forming apparatus comprising the image reading apparatus according to claim 1 as the image reading unit. An image reading processing step of reading an image of a document by an image reading means;
A transport processing step of transporting the document to the image reading means by a transport means;
A guidance processing step of guiding the document to be conveyed by guide means arranged in a state of facing the reading surface of the document conveyed to the image reading unit by the conveyance unit;
The reading surface of the document transported by the transporting means is arranged near the upstream end of the guiding means in the document transport direction by a separating device disposed near the upstream end of the guide means in the document transport direction. A separation processing step of separating a predetermined amount from the guide means;
A length determination processing step for determining whether the transport direction length of the document exceeds a predetermined threshold length;
A drive control processing step for driving the separation unit in a direction to separate the reading surface of the document from the guide unit by a predetermined amount when the length of the document exceeds the threshold length;
An image reading method characterized by comprising:

Images