JP7230611B2 - Image reader - Google Patents

Description

The present disclosure relates to an image reading device.

There is an image forming system in which an image reading device for reading a paper surface after image formation is arranged on the rear stage side of the image forming device. The image forming system can perform various calibrations such as correction of luminance unevenness of an image formed on a sheet using a read image obtained by a reading unit of an image reading device (for example, Japanese Unexamined Patent Application Publication No. 2002-100003, 2).

In the related arts such as those described in Patent Documents 1 and 2, the image forming system performs shading correction as one of various calibrations on the premise that at least there is no paper at the reading position of the reading unit. and Therefore, in an image forming system that forms an image on continuous paper such as roll paper or continuous form paper, shading correction cannot be performed. Therefore, in an image forming system filled with continuous paper, it is necessary to separate the continuous paper from the reading unit when performing shading correction.

Therefore, among image forming systems, there is an image forming system that switches between an arrangement in which the reading section and the continuous paper face each other and an arrangement in which the reading section and the continuous paper do not face each other by moving the reading section or a conveying member for the continuous paper. It has been proposed (see, for example, Patent Document 3).

Japanese Patent Application Laid-Open No. 2002-010041 Japanese Patent Application Laid-Open No. 2002-344709 JP 2017-112451 A

However, the conventional technique as disclosed in Patent Document 3 is costly and requires a large-sized apparatus. Further, if the conveying path of the continuous paper changes due to the movement of the conveying member, the media length of the continuous paper also changes. Therefore, slack is generated in the continuous paper due to the displacement of the media length of the continuous paper. necessary. If the tension applied to the continuous paper is controlled, the distance at which the continuous paper faces the reading section and the distance at which the correction member including the white reference surface used when performing shading correction faces the reading section change. , it is difficult to ensure reading accuracy during shading correction. Therefore, even if the shading correction can be performed, the size and cost of the apparatus cannot be avoided, and it is difficult to ensure the reading accuracy during the shading correction.

The present disclosure has been made in view of such circumstances, and is intended to make it possible to easily ensure reading accuracy during shading correction while avoiding an increase in the size and cost of the apparatus. be.

An image reading apparatus according to one aspect of the present disclosure includes a reading unit that reads an object to be detected at a reading position, an upstream conveying unit that is arranged upstream of the reading unit and conveys continuous paper, and A downstream-side transport unit that is disposed downstream and transports the continuous paper; a sheet-shaped member that is placed on and transported on the continuous paper; a correction member having a white reference surface configured on a surface and being freely arranged at the reading position of the reading unit; a correction member supply unit feeding the correction member to the reading position; a control unit that determines whether or not the reading unit is dirty based on the reading result of the surface of the member, wherein the reading unit follows the conveyance of the continuous paper and corrects the reading position. When the member is fed and faces the white reference surface , the correction member supply unit reads the white reference surface as the object to be detected, and the control unit determines that the reading unit is dirty. In this case, the correction member is continuously sent to the reading unit, or the supply and recovery of the correction member are repeated .

According to one aspect of the present disclosure, it is possible to easily ensure reading accuracy during shading correction while avoiding an increase in size and cost of the apparatus.

1 is a diagram showing an overall configuration example of an image forming apparatus 3 according to an embodiment of the present disclosure; FIG. 6 is a diagram illustrating a configuration example of a reading unit 632 according to an embodiment of the present disclosure; FIG. 6A and 6B are diagrams illustrating an example of a correction member 633 according to an embodiment of the present disclosure; FIG. 6A and 6B are diagrams showing an example of a change in position of a correction member 633 sent to a reading unit 632 according to the embodiment of the present disclosure; FIG. FIG. 6 is a diagram showing a scanning example when reading a correction member 633 according to an embodiment of the present disclosure; FIG. FIG. 7 is a diagram showing an example of reading result of the correction member 633 according to the embodiment of the present disclosure; 4 is a flowchart illustrating a control example according to the embodiment of the present disclosure;

Embodiments of the present disclosure will be described below based on the drawings, but the present disclosure is not limited to the following embodiments.

FIG. 1 is a diagram showing an overall configuration example of an image forming apparatus 3 according to an embodiment of the present disclosure. The image forming apparatus 3 is provided with the paper feeding device 2 and the tensioning mechanism 61 on the front side, and is provided with the image reading device 63, the tensioning mechanism 62 and the winding device 4 on the rear side. 35 and a control unit 301 . The paper feeding device 2 is loaded with roll-shaped continuous paper P1. The winding device 4 accommodates the continuous paper P2 in a roll. Note that the continuous paper P1 and P2 are collectively referred to as the continuous paper P when described. Further, the image forming apparatus 3 may include at least one of the paper feeding device 2 , the winding device 4 , the tensioning mechanism 61 and the tensioning mechanism 62 . The image reading device 63 includes a control section 631 , a reading section 632 , a correction member 633 , a correction member supply section 634 and a paper detection section 75 . Note that the paper detection unit 75 is composed of, for example, a reflective photoelectric sensor, and detects passage of the continuous paper P. As shown in FIG. Details of the image reading device 63 will be described later.

The paper feeding device 2 includes a paper feeding drive section 21 and a paper feeding control section 22 . The paper feed drive unit 21 is composed of, for example, a servo motor, and is driven based on a control command from the paper feed control unit 22 to control the rotational speed of the continuous paper P1. The tension applying mechanism 61 is provided on the rear side of the roll-shaped continuous paper P1, and applies tension to the continuous paper P1. The paper feeding device 2 feeds the continuous paper P1 to the image forming device 3 via the tension imparting mechanism 61 , thereby supplying the continuous paper P1 to which tension is applied to the image forming device 3 .

The tensioning mechanism 61 comprises two driven rollers 611 , dancer rollers 612 , weights 613 , support members 614 and air dampers 615 . The dancer roller 612 includes a roller main body 612a and a roller support shaft 612b, and the roller main body 612a can move up and down together with the roller support shaft 612b. The weight 613 includes a weight main body 613a and a weight support shaft 613b. The tension is determined according to the weight of the weight 613 . A load of the weight 613 is applied to the dancer roller 612 by the support member 614 connecting the roller support shaft 612b and the weight support shaft 613b. The support member 614 is held by an air damper 615 . When the pressure of the air damper 615 is weakened, the holding force of the weight 613 by the support member 614 is weakened, and the load of the weight 613 applied to the dancer roller 612 is increased, so the tension applied to the continuous paper P is increased.

The continuous paper P on which an image has been formed by the image forming device 3 is wound up by the winding device 4 and stored as a roll-shaped continuous paper P2. The winding device 4 includes a winding drive section 41 and a winding control section 42 . The winding drive unit 41 is composed of, for example, a servomotor, and is driven based on a control command from the winding control unit 42 to control the rotation speed of the continuous paper P2. The tension applying mechanism 62 is provided on the front stage side of the roll-shaped continuous paper P<b>2 and applies tension to the continuous paper P. The winding device 4 stores the continuous paper P output from the image forming apparatus 3 as the continuous paper P2 to which tension is applied by winding the continuous paper P2 in a roll form via the tension applying mechanism 62 .

The tensioning mechanism 62 comprises two driven rollers 621 , dancer rollers 622 , weights 623 , support members 624 and air dampers 625 . The dancer roller 622 includes a roller main body 622a and a roller support shaft 622b, and the roller main body 622a can move up and down together with the roller support shaft 622b. The weight 623 includes a weight main body 623a and a weight support shaft 623b. The tension is determined according to the weight of the weight 623 . A load of the weight 623 is applied to the dancer roller 622 by the support member 624 connecting the roller support shaft 622b and the weight support shaft 623b. The support member 624 is held by an air damper 625 . When the pressure of the air damper 625 is weakened, the holding force of the weight 623 by the support member 624 is weakened, and the load of the weight 623 applied to the dancer roller 622 is increased, so the tension applied to the continuous paper P is increased.

That is, the continuous paper P is supported by the dancer roller 612 and two driven rollers 611, so that the dancer roller 612 is driven to rotate in the rotational direction together with the two driven rollers 611, and is supported so as to be vertically movable. , and the vertical movement range is restricted. Similarly, since the continuous paper P is supported by the dancer roller 622 and the two driven rollers 621, the dancer roller 622 is driven to rotate in the rotational direction together with the two driven rollers 621, and is supported so as to be vertically movable. and the vertical movement range is restricted. Therefore, the rotational speeds of the servo motors of the paper feeding driving section 21 and the winding driving section 41 are controlled so that the positions of the dancer rollers 612 and 622 are fixed. In other words, the positions of the dancer rollers 612 and 622 depend on the input/output speed difference between the paper feeding driving section 21 and the winding driving section 41 . Therefore, when the power supply to the paper feeding device 2 and the winding device 4 is stopped, that is, when the power is cut off, the paper feeding driving unit 21 and the winding driving unit 41 also stop being energized. falls under the load applied by weights 613, 623 and its own weight to the lower limit of its range of motion. As a result, the continuous paper P is in a state where no tension is applied.

In the image forming apparatus 3, the continuous paper P is conveyed by the upstream conveying roller pair 37A and the downstream conveying roller pair 37B, passes through the image forming section 34 and the fixing section 35, and is discharged. Further, an edge detecting portion 73 is provided in the conveying path between the upstream side conveying roller pair 37A and the transfer portion 34e. The edge detection unit 73 is composed of, for example, a reflective photoelectric sensor, and detects the edge of the continuous paper P in the main scanning direction CD. Therefore, the edge detector 73 can detect the position of the edge of the continuous paper P in the main scanning direction CD. Therefore, the deviation of the continuous paper P is detected according to the displacement of the position of the end of the continuous paper P in the main scanning direction CD detected by the edge detection unit 73 at regular intervals. Note that the main scanning direction CD will be described later with reference to FIG.

The image forming apparatus 3 has a setting section 36 at the top. The setting unit 36 includes a display unit 36a and an operation unit 36b, receives user operations through the operation unit 36b, and displays information on the display unit 36a. The image forming apparatus 3 includes an automatic document feeding device and a document image scanning device for automatically reading a document on its upper portion. The document image scanning device can read an image through the platen glass. The document image scanning device is used, for example, to read an image of a document and form an image by the image forming section 34 . The image forming section 34 includes image carriers 34d prepared for respective colors such as cyan, magenta, yellow, and black. A device 34c is provided. The image carrier 34d is composed of, for example, a drum-shaped photosensitive member.

The surface of the image carrier 34d charged by the charging device 34a is subjected to image exposure by the exposure device 34b based on the document image data of the print job to form an electrostatic latent image. The electrostatic latent image is developed on the image carrier 34d by the developing device 34c to form a toner image. The transfer section 34e includes an intermediate transfer belt 34e1, a pressing section 34e5, and the like. The transfer portion 34e transfers the toner image transferred onto the intermediate transfer belt 34e1 onto the continuous paper P via a transfer nip (secondary transfer nip) formed by a pressing portion 34e5 that can be pressed against the intermediate transfer belt 34e1. The fixing section 35 performs a fixing process on the continuous paper P to which the toner image has been transferred. The pressing portion 34e5 includes a secondary transfer roller 34e51, a secondary transfer adjusting portion 34e52, and a secondary transfer driving portion 34e53, although the details will be described later. A transfer adjustment unit 34e52 adjusts the position of the secondary transfer roller 34e51.

Although not shown, the transfer section 34e includes a belt cleaning device. The belt cleaning device has a belt cleaning blade or the like, and is brought into sliding contact with the surface of the intermediate transfer belt 34e1. The belt cleaning device removes transfer residual toner remaining on the surface of the intermediate transfer belt 34e1 after secondary transfer.

The intermediate transfer belt 34e1 is formed of an endless belt. A drive roller 34e2, a primary transfer roller 34e3, an opposing roller 34e4, a driven roller 34e6, a steering roller 34e7, and a driven roller 34e8 are arranged on the inner peripheral side of the intermediate transfer belt 34e1. Therefore, the intermediate transfer belt 34e1 is stretched in a loop by a drive roller 34e2, a primary transfer roller 34e3, an opposing roller 34e4, a driven roller 34e6, a steering roller 34e7 and a driven roller 34e8. The drive roller 34e2 is arranged downstream of the primary transfer roller 34e3 for the K component in the belt running direction. As the drive roller 34e2 rotates, the intermediate transfer belt 34e1 runs clockwise at a constant speed. The opposing roller 34e4 is arranged downstream of the drive roller 34e2 and faces the secondary transfer roller 34e51. The driven roller 34e6 is arranged above (downstream) the opposing roller 34e4. The steering roller 34e7 is arranged downstream of the driven roller 34e6 and upstream of the primary transfer roller 34e3 for the Y component, which is positioned most upstream in the rotational direction of the intermediate transfer belt 34e1 among the plurality of primary transfer rollers 34e3. . The driven roller 34e8 is arranged between the Y component primary transfer roller 34e3 and the steering roller 34e7. Between the Y component primary transfer roller 34e3 and the K component primary transfer roller 34e3, the M component primary transfer rollers 34e3 and the C component primary transfer rollers 34e3 are arranged in order from the Y component side. there is

Each of the plurality of primary transfer rollers 34e3 is provided on the inner peripheral surface side of the intermediate transfer belt 34e1, and arranged at a position facing each of the plurality of image carriers 34d. That is, each of the plurality of primary transfer rollers 34e3 is pressed against each of the plurality of image carriers 34d via the intermediate transfer belt 34e1. With such an arrangement configuration, a primary transfer nip is formed between each of the plurality of image carriers 34d and each of the plurality of primary transfer rollers 34e3. At the primary transfer nip, toner images are transferred from each of the plurality of image carriers 34d to the intermediate transfer belt 34e1.

The secondary transfer roller 34e51 is provided on the outer peripheral surface side of the intermediate transfer belt 34e1. The secondary transfer roller 34e51 is called a backup roller, and is pressed against the intermediate transfer belt 34e1 to form a secondary transfer nip. A toner image is transferred from the intermediate transfer belt 34e1 to the continuous paper P at the secondary transfer nip. When the intermediate transfer belt 34e1 passes through the primary transfer nip, the toner images on each of the plurality of image carriers 34d are sequentially superimposed and primarily transferred onto the intermediate transfer belt 34e1. Specifically, when the primary transfer bias is applied to the primary transfer roller 34e3, a charge having a polarity opposite to that of the toner contained in the toner image is generated on the side of the intermediate transfer belt 34e1 that contacts the primary transfer roller 34e3. By being applied, the toner image is electrostatically transferred to the intermediate transfer belt 34e1.

The toner image on the intermediate transfer belt 34e1 is secondarily transferred to the continuous paper P when the toner image is electrostatically transferred to the intermediate transfer belt 34e1 and the continuous paper P passes through the secondary transfer nip. Specifically, by applying a secondary transfer bias to the secondary transfer roller 34e51, the side of the back surface of the continuous paper P that contacts the secondary transfer roller 34e51 is charged with the opposite polarity of the toner. As a result, the toner image is electrostatically transferred to the continuous paper P. As shown in FIG. The continuous paper P onto which the toner image has been transferred is conveyed toward the fixing section 35 .

The secondary transfer adjusting portion 34e52 is composed of an L-shaped member and includes a long piece, a short piece, and a cam. The long piece has a distal end portion that rotatably supports the secondary transfer roller 34e51 and a proximal end portion that forms a bent portion. This bent portion is swingably supported by a support pin and engages the short piece. Therefore, according to the driving force of the secondary transfer drive unit 34e53, the cam presses the short piece with the transfer pressing force, so that the long piece rotates around the support pin, and the secondary transfer roller 34e51 moves the intermediate transfer belt 34e1. can be pushed upward to form a secondary transfer nip. Since the pre-transfer transport roller 74 is provided in the secondary transfer nip before transfer, tension is applied to the continuous paper P by the pre-transfer transport roller 74 . This tension is applied to the continuous paper P in order to suppress the meandering amount of the continuous paper P. The transfer pressing force is to press the secondary transfer roller 34e51 against the intermediate transfer belt 34e1 to form a secondary transfer nip.

In the transfer unit 34e, instead of the secondary transfer roller 34e51, a secondary transfer belt (not shown) is stretched around a plurality of support rollers (not shown) including the secondary transfer roller 34e51 in a loop. , a belt-type secondary transfer unit may be employed.

The fixing section 35 includes a first rotating member 352 and a second rotating member 353 . The first rotating member 352 includes a heating roller 352a, a heating source 352b, a fixing belt 352c and an upper pressure roller 352d. The heating source 352b is provided inside the heating roller 352a, is capable of raising the temperature, and heats the heating roller 352a. An upper pressure roller 352d is provided below the heating roller 352a. The fixing belt 352c is endless, and is wound around the heating roller 352a and the upper pressure roller 352d. A fixing nip is formed via the fixing belt 352c by pressing the second rotating member 353 functioning as a lower pressure roller against the upper pressure roller 352d. When the second rotating member 353 is separated from the upper pressure roller 352d, that is, the first rotating member 352, the fixing nip is released. Even if the fixing nip is released, the continuous paper P is wound around the second rotating member 353 if tension is applied to the continuous paper P.

The first rotating member 352 is driven by an upper drive section 354 . The upper driving section 354 causes the first rotating member 352 to travel at a constant speed under the control of the control section 301 . For example, by driving the upper pressure roller 352d, while the fixing belt 352c is running at a constant speed, the heat supplied from the heating roller 352a through the fixing belt 352c is formed on the upper pressure roller 352d. transmitted to the nip. Therefore, the temperature of the fixing belt 352 c can be regarded as the temperature of the first rotating member 352 . A second rotating member 353 is driven by a lower driving portion 355 . Under the control of the control unit 301 , the lower driving unit 355 separates the second rotating member 353 from the first rotating member 352 or presses the second rotating member 353 against the first rotating member 352 . let In other words, the positional relationship between the upper pressure roller 352d and the second rotating member 353 functioning as the lower pressure roller is either the separated state or the pressure contact state.

An upper temperature detector 71 is provided at a position facing the fixing belt 352c. The upper temperature detector 71 detects the temperature of the fixing belt 352c. A lower temperature detector 72 may be provided around the second rotating member 353 . The lower temperature detector 72 detects the temperature around the second rotating member 353 . Heat is transferred from the first rotating member 352 to the second rotating member 353 via the fixing nip, but a device similar to the heat source 352b may be provided inside the second rotating member 353. .

In other words, the image forming section 34 is capable of forming an image on the continuous paper P by electrophotography. A drum cleaning device 34g is provided around the image carrier 34d. The drum cleaning device 34g removes residual toner remaining on the transfer portion 34e. The control unit 301 includes a CPU, ROM, RAM, and I/O interface (not shown), and is used as a computer that controls the image forming apparatus 3 . The CPU reads a program from the ROM according to the processing content, develops it in the RAM, and controls the operation of the image forming apparatus 3 in cooperation with the developed program. The program is for realizing various control functions. The control unit 301 is also used as a processor mainly composed of a CPU.

FIG. 2 is a diagram illustrating a configuration example of the reading unit 632 according to the embodiment of the present disclosure. As shown in FIG. 2, an upstream transport section 38A composed of rollers is provided on the upstream side of the reading section 632 in the transport direction. 39 A of upstream regulation parts which regulate the height direction of P are provided. The continuous paper P is conveyed from the upstream conveying portion 38A and passes through the reading position L while being regulated in the height direction by the upstream regulating portion 39A. A downstream transport section 38B composed of rollers is provided downstream of the reading section 632 in the transport direction. A downstream regulation portion 39B is provided. The continuous paper P that has passed through the reading position L is conveyed to the tension applying mechanism 62 by the downstream conveying section 38B while being regulated in the height direction by the downstream regulating section 39B.

The reading unit 632 includes a CCD 632B and an optical system 632C inside a housing 632A, and a plurality of light sources 632D inside a protrusion 632F of the housing 632A. A transparent member 632G made of glass or the like is provided at a position facing the reading position L on the projecting portion 632F. Therefore, the continuous paper P passes under the transparent member 632G. The CCD 632B is composed of a color line sensor capable of reading the entire width range in the width direction of the continuous paper P, that is, the main scanning direction CD, and reads the image formed on the continuous paper P at the reading position L. The optical system 632C includes a plurality of mirrors and lenses, and guides the image at the reading position L to the CCD 632B. The light source 632D is composed of an LED, for example, and illuminates the reading position L. With such a configuration, the reading section 632 reads the image over the entire width in the main scanning direction CD as the continuous paper P is conveyed in the conveying direction, that is, in the sub-scanning direction FD (described later with reference to FIG. 5). Therefore, as the continuous paper P advances in the sub-scanning direction FD, the reading range S (described later with reference to FIG. 5) of the object to be detected at the reading position L read by the reading unit 632 along the main scanning direction CD is a certain size.

By the way, the reading unit 632 may produce deviations in reading results due to variations in the imaging device such as the CCD 632B, unevenness caused by the temperature and the light source 632D, stains adhering to the transparent member 632G, and the like. Therefore, in order to correct such deviation of the reading result, the image reading device 63 needs to periodically perform shading correction according to the reading result of the reference surface (to be described later). The execution timing of shading correction is when the power of the image reading device 63 is turned on, when the image reading device 63 is operated for the first time on the day, after maintenance, when there is a pause between jobs, and when reading is performed for a certain period of time during a job. There is a periodical correction time.

As will be described later, the correction member 633 is conveyed to the reading position L following the continuous paper P. FIG. The image reading device 63 also includes a control section 631 . The control unit 631 has the same configuration as the control unit 301 , and can communicate with other control mechanisms such as the control unit 301 while controlling the entire image reading device 63 .

FIG. 3 is a diagram illustrating an example of a correction member 633 according to embodiments of the present disclosure. The correction member 633 is composed of a sheet-like member 633A. The sheet member 633A is a member having flexibility, and is placed on the continuous paper P and conveyed. Therefore, the correction member 633 can be arranged in a rolled state. The sheet member 633A includes a white reference surface 633D and a black reference surface 633E as reference surfaces for determining correction values for shading correction. The white reference surface 633D is formed along the main scanning direction CD of the continuous paper P on the surface of the sheet member 633A. The black reference plane 633E is configured adjacent to the white reference plane 633D. The sheet-like member 633A includes a cleaning member 633B in addition to the white reference surface 633D and the black reference surface 633E. The cleaning member 633B is arranged for each reference surface consisting of a white reference surface 633D and a black reference surface 633E, and can clean the surface of the reading section 632 facing the reading position L (see FIG. 2). The cleaning member 633B is composed of a flocked cloth, a sponge-like foam material, or the like. The sheet-like member 633A is formed by repeating a plurality of sets of a cleaning member 633B, a white reference surface 633D and a black reference surface 633E. The sheet-like member 633A further includes ribs 633C. The rib 633C has a projection shape provided outside the reading range S (see FIG. 5) of the reading section 632 along the longitudinal direction of the sheet member 633A. The rib 633C is a flexible member similar to the sheet member 633A. In addition, the correction member 633 follows the conveyance of the continuous paper P by the friction of the back surface of the sheet member 633A. In other words, if the correction member 633 is placed on the continuous paper P, it is transported in the transport direction together with the transport of the continuous paper P, and can be freely arranged at the reading position L (see FIG. 2) of the reading unit 632. be.

FIG. 4 is a diagram showing an example of positional change of the correction member 633 fed to the reading unit 632 according to the embodiment of the present disclosure. FIG. 4A is a diagram showing an example in which the correction member 633 is arranged on the upstream side of the reading section 632. FIG. As shown in FIG. 4A, the correction member 633 is arranged in a rolled state, and the continuous paper P is transported along the transport direction, that is, the sub-scanning direction FD. In other words, the correction member supply unit 634 (see FIG. 1) can collect the correction member 633 in a roll shape. FIG. 4B shows an example in which the correction member 633 following the conveyance of the continuous paper P is sent to the reading section 632 . In the example of FIG. 4(b), the cleaning member 633B is fed into the reading section 632. As shown in FIG. On the other hand, the correction member supply section 634 (see FIG. 1) feeds the correction member 633 to the reading position L (see FIG. 2), and transports the continuous paper P by the upstream transport section 38A and the downstream transport section 38B. The supply speed for feeding the correction member 633 to the reading unit 632 is made smaller than the speed.

FIG. 4C shows an example in which the white reference surface 633D is fed to the reading position L of the reading section 632 (see FIG. 2). In the example of FIG. 4C, the reading unit 632 reads the white reference plane 633D as the object to be detected when facing the white reference plane 633D. Although not shown, when the black reference surface 633E is sent to the reading unit 632 and the reading unit 632 faces the black reference surface 633E, the reading unit 632 reads the black reference surface 633E as an object to be detected. FIG. 4D shows an example in which the correction member 633 is pulled out from the reading unit 632 and recovered. In the example of FIG. 4D, when the reading unit 632 reads the white reference surface 633D, the correction member supply unit 634 (see FIG. 1) pulls out the correction member 633 from the reading position L (see FIG. 2). to recover. On the other hand, when the correcting member 633 is pulled out and collected from the reading position L (see FIG. 2) by the correcting member supply unit 634 (see FIG. 1), the upstream transport unit 38A transports the continuous paper P. direction, that is, the direction opposite to the sub-scanning direction FD. The downstream transport section 38B operates in the same manner as the upstream transport section 38A.

In the example of FIG. 4(d), the correction member 633 is collected by the correction member supply unit 634 (see FIG. 1). For example, the correction member supply unit 634 (see FIG. 1) continues to feed the correction member 633 to the reading unit 632 .

FIG. 5 is a diagram illustrating a scanning example when reading the correction member 633 according to the embodiment of the present disclosure. As shown in FIG. 5, the range of main scanning positions from b(0) to b(m−1) in the reading range S is the main scanning position range along the main scanning direction CD. On the other hand, the sub-scanning position range in the reading range S continues along the sub-scanning direction FD while the reading unit 632 continues the reading operation. FIG. 6 is a diagram showing an example of reading results of the correction member 633 according to the embodiment of the present disclosure. In FIG. 6A, when the sub-scanning position on the sub-scanning direction FD is a(0) in FIG. ) is a diagram showing an example of the reading result of the reading unit 632 in terms of luminance values. In the example of FIG. 6A, among the luminance values of the reading result of the reading unit 632, the values below the correction member contamination threshold TH(1) exist at the main scanning position b(q2). Further, among the luminance values of the reading result of the reading unit 632, the values that are not below the correction member contamination threshold TH(1) but have a certain decrease in the luminance value are those at the main scanning position b(q1). exists in place.

In FIG. 6B, when the sub-scanning position on the sub-scanning direction FD is a(n−1) in FIG. -1) is a diagram showing an example of the reading result of the reading unit 632 in terms of luminance values. In the example of FIG. 6B, among the luminance values of the reading result of the reading unit 632, there is no value lower than the correction member contamination threshold TH(1). Further, among the luminance values of the reading result of the reading unit 632, the values that are not below the correction member contamination threshold TH(1) but have a certain decrease in the luminance value are those at the main scanning position b(q1). exists in place.

Referring to FIG. 5, the location where the main scanning position corresponds to b(q1) and the sub-scanning position corresponds to the range from a(0) to a(n-1) is K(1). , the sheet-like member 633A is free of dirt. On the other hand, the location where the main scanning position corresponds to b(q2) and the sub-scanning position corresponds to the range from a(0) to a(n−1) is K(2). Dirt is present on 633A. Therefore, at a specific sub-scanning position, it is not possible to determine whether or not the sheet-like member 633A is soiled, that is, whether the correction member 633 is soiled or not, based only on the reading result of the reading unit 632 reading along the main scanning direction CD.

Then, it demonstrates using FIG.6(c). FIG. 6C shows the peak hold value of the reading result of the reading unit 632 at different sub-scanning positions for each main scanning position at regular intervals in the sub-scanning position range from a(0) to a(n−1). It is a figure which shows an example which calculated|required a_PH. In the example of FIG. 6C, when the peak hold value a_PH is less than the reading unit dirt threshold TH(2), it is determined that the reading unit 632 is dirty, and the peak hold value a_PH becomes the reading unit dirt threshold TH(2). , it is determined that the reading unit 632 is not soiled. For example, at the location where the main scanning position is b(q2), the peak hold value a_PH does not fall below the reading unit dirt threshold TH(2), so it is determined that the reading unit 632 is not dirty. Therefore, the peak hold value a_PH hides the data regarding the contamination of the correction member 633, so that it is possible to determine whether or not the reading unit 632 has an abnormality. Specifically, when the control unit 631 determines that the reading unit 632 is dirty, the correction member supply unit 634 continuously feeds the correction member 633 to the reading unit 632, or supplies and collects the correction member 633. and repeat.

Regarding the contamination of the correction member 633, among the reading results of the reading unit 632, there is a value below the correction member contamination threshold TH(1), and the value below the correction member contamination threshold TH(1) is the same as the value below the correction member contamination threshold TH(1). If there is no reading result of the reading unit 632 at the scanning position that is lower than the correction member dirt threshold TH(1), it is determined that the correction member 633 is dirty. For example, the above condition applies to the location where the main scanning position is b(q2).

FIG. 7 is a flow chart illustrating a control example according to the embodiment of the present disclosure. In step S11, the control section 631 determines whether or not the continuous paper P is being transported. If the control unit 631 determines that the continuous paper P is being transported (step S11; Y), the process proceeds to step S13. When the control unit 631 determines that the continuous paper P is not conveyed (step S11; N), the process proceeds to step S12, and in step S12, the continuous paper P is started to be conveyed, and the process proceeds to step S13. Transition. In step S13, the control unit 631 feeds the correction member 633, and proceeds to the process of step S14. In step S14, the control section 631 causes the cleaning member 633B to clean the surface of the transparent member 632G, and proceeds to the process of step S15. In step S15, the control unit 631 executes shading correction using the white reference plane 633D, and proceeds to the process of step S16. In step S16, the control unit 631 executes shading correction using the black reference plane 633E, and proceeds to the process of step S17.

In step S<b>17 , the control unit 631 determines whether or not the reading result of the reading unit 632 has a value lower than the correction member contamination threshold TH(1). If the control unit 631 determines that there is a value below the correction member contamination threshold TH(1) among the reading results of the reading unit 632 (step S17; Y), the process proceeds to step S20. If the control unit 631 determines that there is no value less than the correction member contamination threshold TH(1) among the read results of the reading unit 632 (step S17; N), the control unit 631 proceeds to the process of step S18. , the correction member 633 is pulled out, the process proceeds to step S19, the conveyance of the continuous paper P is stopped in step S19, and the process ends.

In step S20, the control unit 631 determines that among the reading results of the reading unit 632 at the same main scanning position as the value below the correction member dirt threshold TH(1), the value below the correction member dirt threshold TH(1) is further Determine if it exists. The control unit 631 determines that among the reading results of the reading unit 632 at the same main scanning position as the value below the correction member dirt threshold TH(1), there is a further value below the correction member dirt threshold TH(1). If so (step S20; Y), the process proceeds to step S25. The control unit 631 determines that among the reading results of the reading unit 632 at the same main scanning position as the value below the correction member contamination threshold TH(1), there is no further value below the correction member contamination threshold TH(1). If so (step S20; N), the process proceeds to step S21. In step S21, the control unit 631 determines that the correction member 633 is dirty, and proceeds to step S22.

In step S22, the control unit 631 determines whether or not a plurality of sets of the cleaning member 633B, the white reference surface 633D and the black reference surface 633E are arranged on the sheet member 633A. If the control unit 631 determines that a plurality of sets of the cleaning member 633B, the white reference surface 633D, and the black reference surface 633E are arranged on the sheet-like member 633A (step S22; Y), the process of step S13 is performed. back to If the control unit 631 determines that a plurality of sets of the cleaning member 633B, the white reference surface 633D, and the black reference surface 633E are not arranged on the sheet-like member 633A (step S22; N), the process of step S23 is performed. transition to In step S23, the control unit 631 causes the correction member 633 to be pulled out, and proceeds to the process of step S24. In step S24, the control unit 631 replaces the correction member 633, and returns to the process of step S13.

In step S25, the control unit 631 obtains the peak hold value a_PH of the reading result of the reading unit 632 at different sub-scanning positions for each main scanning position at regular intervals, and proceeds to the process of step S26. In step S26, the control section 631 determines whether or not the peak hold value a_PH is below the reading section dirt threshold TH(2). If the control unit 631 determines that the peak hold value a_PH is less than the reading unit dirt threshold TH(2) (step S26; Y), the process proceeds to step S27, and in step S27, the reading unit 632 is dirty. , and the process returns to step S13. If the control unit 631 determines that the peak hold value a_PH does not fall below the reading unit contamination threshold TH(2) (step S26; N), the process ends.

From the above description, in the present embodiment, when the correction member 633 is fed to the reading position L following the conveyance of the continuous paper P and faces the white reference surface 633D, the reading unit 632 detects a white object as an object to be detected. Read the reference plane 633D. Therefore, since the correcting member 633 can follow the transportation of the continuous paper P to the reading unit 632 , there is no need to separate the continuous paper P from the reading unit 632 . Therefore, since the transport path of the continuous paper P and the media length of the continuous paper P are not affected, it is unnecessary to control the tension by the tension applying mechanism 61 and the tension applying mechanism 62, and it is not necessary to increase the size of the device. . Further, with the above configuration, the white reference surface 633D can be read by the reading unit 632, so shading correction can be performed with a low-cost configuration. In addition, since the correction member 633 is placed on the continuous paper P and conveyed, the distance between the reading unit 632 and the continuous paper P is assumed to be the same as the distance between the reading unit 632 and the correction member 633. can be regarded as Therefore, it is possible to easily ensure reading accuracy during shading correction while avoiding an increase in the size and cost of the apparatus.

Further, in this embodiment, when the reading unit 632 reads the white reference surface 633D, the correction member supply unit 634 pulls out the correction member 633 from the reading position L and collects it. Therefore, since the correction member 633 is recovered, the correction member 633 can be sent to the reading position L again. Therefore, the correction member 633 can be used repeatedly.

Further, in this embodiment, the correction member 633 is arranged on the upstream side of the reading section 632 . Therefore, the correction member 633 is sent to the reading section 632 along the same direction as the continuous paper P transport direction. Therefore, the correction member 633 can be fed to the reading position L even when the continuous paper P is being conveyed.

Moreover, in this embodiment, the sheet member 633A is a flexible member. Therefore, the correction member 633 has few restrictions on length and size. Therefore, the handling cost of the correction member 633 can be reduced.

Further, in the present embodiment, the correction member supply unit 634 can collect the correction member 633 in a roll shape. Therefore, the supply mechanism for the correction member 633 can be realized only by the rotation mechanism. Therefore, the correction member 633 can be sent to the reading section 632 with a simple configuration. Also, with a simple configuration, the correction member 633 can be pulled out from the reading unit 632 and collected.

In addition, in the present embodiment, the sheet member 633A is arranged for each reference plane consisting of a black reference plane 633E configured adjacent to the white reference plane 633D and the white reference plane 633D and the black reference plane 633E, A cleaning member 633B capable of cleaning the surface of the reading unit 632 facing the reading position L is further included. Therefore, the cleaning member 633B, the white reference surface 633D and the black reference surface 633E are arranged side by side. Therefore, the cleaning of the surface of the reading unit 632 facing the reading position L, the shading correction by the white reference surface 633D, and the shading correction by the black reference surface 633E can be realized in one operation.

Further, in this embodiment, the sheet-like member 633A is formed by repeating a plurality of sets of the cleaning member 633B, the white reference surface 633D and the black reference surface 633E. Therefore, even if one reference surface is stained or defective, it is possible to use reference surfaces at different locations, or to perform shading operations a plurality of times in succession.

Further, in the present embodiment, the correction member 633 follows the conveyance of the continuous paper P by the friction of the back surface of the sheet member 633A. Therefore, a separate mechanism for sending the correction member 633 to the reading section 632 is not required. Therefore, the correction member 633 can be sent to the reading section 632 at low cost.

Further, in this embodiment, the correction member supply unit 634 makes the supply speed of the correction member 633 to the reading unit 632 smaller than the conveying speed of the continuous paper P by the upstream conveying unit 38A and the downstream conveying unit 38B. Therefore, the transport speed of the continuous paper P is faster than the supply speed of the correction member 633 . Therefore, since the correction member 633 is pulled by the continuous paper P, the slack of the correction member 633 can be prevented.

Further, in the present embodiment, when the correcting member 633 is pulled out from the reading position L by the correcting member supply unit 634 and collected, the upstream conveying unit 38A feeds the continuous paper P in the direction opposite to the conveying direction of the continuous paper P. transport to Therefore, when the correction member 633 is pulled out, the continuous paper P is transported in the direction opposite to the transport direction. Therefore, the load when pulling out the correction member 633 can be reduced. Further, since the correction member 633 is pulled out from the reading position L and recovered, it can be completely retracted from the continuous paper P. Therefore, the correction member 633 is less likely to become dirty, and the correction member 633 can be kept in a reusable state.

Further, in the present embodiment, when the control unit 631 determines that the reading unit 632 is dirty, the correction member supply unit 634 continuously feeds the correction member 633 to the reading unit 632 or Supply and collection are repeated. Therefore, it is possible to automatically deal with contamination.

Further, in the present embodiment, the correction member supply section 634 continues to feed the correction member 633 to the reading section 632 while the reading section 632 is reading the surface of the sheet-like member 633A. Therefore, the reading section 632 reads the surface of the sheet-like member 633A while the correction member 633 is being fed. Therefore, even if the correction member 633 is dirty, the influence of the dirt on the correction member 633 can be reduced.

Further, in the present embodiment, the sheet-like member 633A is provided with protrusion-shaped ribs 633C outside the reading range S of the reading unit 632 along the longitudinal direction of the sheet-like member 633A. Therefore, the upstream transport section 38A and the downstream transport section 38B do not contact the white reference surface 633D and the black reference surface 633E. Therefore, even if at least one of the white reference surface 633D and the black reference surface 633E is stained, it is possible to prevent such stains from adhering to the upstream transport section 38A and the downstream transport section 38B.

The image forming apparatus 3, the paper feeder 2, and the take-up device 4 according to the present disclosure have been described above based on the embodiments, but the present disclosure is not limited to this, and is within the scope of the present disclosure. and you can make changes.

In the present embodiment, an example has been described in which the tension applying mechanism 61 is provided on the rear stage side of the paper feeding device 2 and the tension applying mechanism 62 is provided on the front stage side of the winding device 4, but the present invention is not particularly limited to this. not something. For example, the tension applying mechanisms 61 and 62 may be provided inside the image forming apparatus 3 .

Also, in the present embodiment, an example in which the tension applying mechanism 61 includes the weight 613 and the support member 614 separately has been described, but it is not particularly limited to this. For example, tensioning mechanism 61 may include a dancer arm in which weight 613 and support member 614 are integrally constructed. If tensioning mechanism 61 includes a dancer arm, air damper 615 may hold the dancer arm. The tension applying mechanism 62 is similar.

Further, in the present embodiment, an example in which the tension applying mechanism 61 applies tension to the continuous paper P using the weight 613 has been described, but the present invention is not particularly limited to this. For example, the tension applying mechanism 61 may apply tension to the continuous paper P by applying pressure to the dancer roller 612 by applying a load to the dancer roller 612 with an air cylinder or a spring. If the tension applying mechanism 61 is an air cylinder, the air pressure fluctuations in the pressurization by the air cylinders are the tension fluctuations. Also, if the tensioning mechanism 61 is a spring, a damper is provided to stabilize the spring. The tension applying mechanism 62 is similar.

Further, in the present embodiment, an example of the configuration in which the first rotating member 352 includes the fixing belt 352c as the belt heating method has been described, but the present invention is not particularly limited to this. For example, the first rotating member 352 may be configured as a roller heating system. Moreover, although an example in which the second rotating member 353 functions as a lower pressure roller has been described as the roller pressure method, the present invention is not particularly limited to this. For example, a configuration in which the second rotating member 353 is provided with a pressure belt as a belt pressure method may be employed.

Further, in the present embodiment, an example in which the image forming apparatus 3 adopts an electrophotographic system has been described, but the image forming apparatus 3 is not particularly limited to this. For example, the image forming apparatus 3 may employ an inkjet method. If the image forming apparatus 3 according to the present disclosure is applied to the image forming apparatus 3 of the ink jet system, even if heat is applied to quickly fix the ink, the printing cost increases and the image Quality deterioration can be suppressed.

Further, in the present embodiment, an example in which the fixing section 35 fixes the toner image on the continuous paper P by the fixing nip has been described, but the fixing section 35 is not particularly limited to this. For example, the fixing section 35 may be of flash fixing that fixes the toner image on the continuous paper P by heat of light.

Also, in the present embodiment, an example in which the edge detector 73 is configured by a reflective photoelectric sensor has been described, but the configuration is not particularly limited to this. For example, it may consist of a transmissive photoelectric sensor.

Also, in the present embodiment, an example of using the luminance value as the reading result of the reading unit 632 has been described, but the present invention is not particularly limited to this. For example, the amount of light may be used as the reading result of the reading unit 632 .

Also, in the present embodiment, an example using the CCD 632B as an imaging device of the reading unit 632 has been described, but the imaging device is not particularly limited to this. For example, a CMOS may be used as the imaging element of the reading unit 632 .

Further, in this embodiment, an example in which the correction member 633 is arranged on the upstream side of the reading unit 632 has been described, but the present invention is not particularly limited to this. For example, the correction member 633 may be arranged downstream of the reading section 632 . Further, the correction member 633 may be arranged beside the reading section 632 .

Also, in the present embodiment, an example in which the sheet-like member 633A is a flexible member has been described, but the present invention is not particularly limited to this. The sheet member 633A may be a non-flexible member. For example, the sheet-like member 633A may be a plate-like member of a certain size.

Further, in the present embodiment, an example including the white reference surface 633D and the black reference surface 633E as reference surfaces for shading correction on the surface of the sheet-like member 633A has been described, but the present invention is particularly limited to this. not a thing Only the white reference surface 633D may be formed on the surface of the sheet member 633A as a reference surface for shading correction.

2 paper feeding device 21 paper feeding driving section 22 paper feeding control section 3 image forming device 34 image forming section 34a charging device 34b exposure device 34c developing device 34d image carrier 34e transfer section 34e1 intermediate transfer belt 34e2 driving roller 34e3 primary transfer roller 34e4 opposing roller 34e6, 34e8 driven roller 34e7 steering roller 34e5 pressing section 34e51 secondary transfer roller 34e52 secondary transfer adjusting section 34e53 secondary transfer driving section 34g drum cleaning device 35 fixing section 352 First rotating member 352a Heating roller 352b Heating source 352c Fixing belt 352d Upper pressure roller 353 Second rotating member 354 Upper drive unit 355 Lower drive unit 36 Setting unit 36a Display unit 36b Operation unit 37A upstream transport roller pair 37B downstream transport roller pair 38A upstream transport section 38B downstream transport section 39A upstream regulation section 39B downstream regulation section 301 control section 4 winding device 41 winding driving section 42 winding Take control unit 61 tension applying mechanism 611 driven roller 612 dancer roller 612a roller main body 612b roller support shaft 613 weight 613a weight main body 613b weight support shaft 614 support member 615 air damper 62 tension applying mechanism 621 driven roller 622 Dancer roller 622a Roller body 622b Roller shaft 623 Weight 623a Weight body 623b Weight shaft 624 Supporting member 625 Air damper 63 Image reading device 631 Control unit 632 Reading unit 632A Housing 632B CCD 632C Optics System 632D Light source 632F Protrusion 632G Transparent member 633 Correction member 633A Sheet member 633B Cleaning member 633C Rib 633D White reference surface 633E Black reference surface 634 Correction member supply unit 71 Upper temperature detection unit 72 Lower temperature detection 73 Edge detection unit 74 Pre-transfer transport roller 75 Paper detection unit P, P1, P2 Continuous paper L Reading position S Reading range TH (1) Correction member dirt threshold TH (2) Reading unit dirt threshold FD Sub Scanning direction, CD Main scanning direction a_PH Peak hold value

Claims (12)

a reading unit that reads an object to be detected at a reading position;
an upstream transport unit arranged upstream of the reading unit and transporting the continuous paper;
a downstream-side conveying unit arranged downstream of the reading unit and conveying the continuous paper;
a sheet-shaped member that is placed on and conveyed on the continuous paper; a compensating member that can be placed in any position;
a correction member supply unit that feeds the correction member to the reading position;
a control unit that determines whether or not the reading unit is soiled based on the reading result of the surface of the sheet-like member by the reading unit;
with
The reading unit
when the correction member is fed to the reading position following the conveyance of the continuous paper and faces the white reference surface, the white reference surface is read as the object to be detected;
When the control unit determines that the reading unit is dirty, the correction member supply unit continuously feeds the correction member to the reading unit, or repeats supply and recovery of the correction member.
Image reader. The correction member supply unit includes :
When the white reference surface is read by the reading unit, the correction member is pulled out from the reading position and collected.
The image reading device according to claim 1. The correction member is
arranged upstream of the reading unit,
The image reading device according to claim 1 or 2. The sheet-shaped member is
A member having flexibility,
The image reading device according to any one of claims 1 to 3. The correction member supply unit includes:
The correction member can be collected in a roll shape,
The image reading device according to any one of claims 1 to 4. The sheet-shaped member is
a black reference surface configured adjacent to the white reference surface;
a cleaning member disposed for each reference plane consisting of the white reference plane and the black reference plane and capable of cleaning a surface of the reading unit facing the reading position;
further comprising
The reading unit
When the correcting member is fed to the reading position following the conveyance of the continuous paper and faces the black reference surface, the black reference surface is read as the object to be detected.
The image reading device according to any one of claims 1 to 5. The sheet-shaped member is
A plurality of sets of the cleaning member, the white reference surface, and the black reference surface are repeatedly configured.
7. The image reading device according to claim 6. The correction member is
Following the conveyance of the continuous paper by the friction of the back surface of the sheet-like member;
The image reading device according to any one of claims 1 to 7. The correction member supply unit includes:
setting a supply speed for feeding the correction member to the reading unit to be lower than a speed of conveying the continuous paper by the upstream conveying unit and the downstream conveying unit;
The image reading device according to any one of claims 1 to 8. The upstream transport section is
When the correction member is pulled out from the reading position and collected by the correction member supply unit, the continuous paper is conveyed in a direction opposite to the conveying direction of the continuous paper.
The image reading device according to any one of claims 1 to 9. The correction member supply unit includes:
While the surface of the sheet-shaped member is being read by the reading unit, the correction member is continuously fed to the reading unit;
The image reading device according to any one of claims 1 to 10 . The sheet-shaped member is
A protruding rib provided outside the reading range of the reading unit along the longitudinal direction of the sheet-like member;
further comprising
The image reading device according to any one of claims 1 to 11 .

Images