Patent ID: 12197158

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments to which the present invention is applied will be described in detail with reference to the drawings. In this specification and the drawings, substantially the same components are denoted by the same reference numerals, and redundant description will be omitted.

1. First Embodiment

First, an image forming system according to a first embodiment of the present invention will be described below with reference toFIGS.1to6.

<Configuration of Image Forming System>

First, a configuration of an image forming system according to the first embodiment will be described with reference toFIG.1.

FIG.1is a diagram illustrating a schematic configuration of an image forming system according to the first embodiment.

As shown inFIG.1, an image forming system10includes a recording material feeding device100, a recording material conveying device400, an image forming apparatus200, and a post-processing device300.

In the image forming system10, when an image is formed on a recording material S, first, the recording material S is supplied from the recording material feeding device100to the recording material conveying device400. Then, the recording material conveying device400conveys the recording material S to the image forming apparatus200. Note that the recording material conveying device400includes a stiffness measuring device410that measures the stiffness of the recording material S.

Next, the image forming apparatus200forms an image on the recording material S supplied from the recording material conveying device400. Then, the image forming apparatus200sends the recording material S on which the image is formed to the post-processing device300. The post-processing device300performs predetermined post-processing on the recording material S on which the image is formed. Thereafter, the post-processing device300ejects the recording material S.

[Recording Material Feeding Device]

The recording material feeding device100stores the recording material S for image formation. Upon receiving an image forming job from a controller90(to be described later) of the image forming system10, the recording material feeding device100supplies the recording material S corresponding to the image forming job to the recording material conveying device400. The recording material feeding device100includes a conveying portion50and a recording material feeding section70.

The recording material feeding section70includes a plurality of recording material storage portions. The recording materials S of different types and sizes are individually stored in the plurality of recording material storage portions. In the present embodiment, the recording material S is a recording medium on which an image is to be formed, and is, for example, a sheet. The recording material S may be anything other than a sheet as long as the stiffness thereof can be measured.

The conveying portion50includes a plurality of take-out rollers for taking out the recording material S from the recording material feeding section70, and a plurality of conveying rollers54. InFIG.1, the take-out rollers are not shown. The plurality of conveying rollers54are arranged in a predetermined recording material conveyance path. The plurality of conveying rollers54convey the recording material S taken out from the recording material feeding section70to the recording material conveying device400one by one.

[Recording Material Conveying Device]

The recording material conveying device400includes a carry-in port a first conveying portion51, a second conveying portion52, a third conveying portion53, a ejection portion56, a carry-out port57, the stiffness measuring device410, and a recording material detector420.

The carry-in port55carries in the recording material S supplied from the recording material feeding device100. The first conveying portion51, the second conveying portion52, and the third conveying portion53convey the recording material S carried in from the carry-in port55to the ejection portion56or the carry-out port57. The first conveying portion51, the second conveying portion52, and the third conveying portion53include a plurality of conveying rollers54for conveying the recording material S.

The stiffness measuring device410is a device that acquires the stiffness of the recording material S. The stiffness of the recording material S is an index indicating resistance to bending of the recording material S, and can be expressed using various physical quantities. The recording material detector420detects that the recording material S has been conveyed to a position where the stiffness is measured. Hereinafter, the position for measuring the stiffness of the recording material S is referred to as a “stiffness measurement position”.

The recording material conveying device400includes a branching portion58by which the conveyance path of the recording material S is branched. The recording material conveying device400includes a first conveyance path41located on the upstream side of the branching portion58in the recording material conveyance direction, and a second conveyance path42and a third conveyance path43located on the downstream side of the branching portion58in the recording material conveyance direction.

The first conveyance path41is a path from the carry-in port55to the branching portion58. The first conveying portion51is disposed in the first conveyance path41. The first conveying portion51conveys the recording material S along the first conveyance path41. The recording material S conveyed along the first conveyance path41is guided to the second conveyance path42or the third conveyance path43by the branching portion58.

The second conveyance path42is a path from the branching portion58to the ejection portion56. The second conveying portion52is disposed in the second conveyance path42. The second conveying portion52conveys the recording material S along the second conveyance path42. The stiffness measuring device410measures the stiffness of the recording material S whose conveyance is stopped in the middle of the second conveyance path42. The recording material S whose stiffness has been measured by the stiffness measuring device410is again conveyed along the second conveyance path42and is ejected from the ejection portion56.

The third conveyance path43is a path from the branching portion58to the carry-out port57. The third conveying portion53is disposed in the third conveyance path43. The third conveying portion53conveys the recording material S along the third conveyance path43. The recording material S conveyed along the third conveyance path43is ejected from the carry-out port57. The recording material S ejected from the carry-out port57is supplied to the image forming apparatus200.

[Image Forming Apparatus]

The image forming apparatus200includes an operation display unit220, a scanner230, an image forming section240, and a conveying portion250.

The operation display unit220includes an operation part and a display part. The display part is, for example, a display device such as a liquid crystal display (LCD). The display part displays various screens according to an instruction of a display signal input from the controller90(seeFIG.2), which will be described later. The operation part includes a touch screen formed so as to cover the display screen of the display part, and various operation buttons such as numeric buttons and a start button. The operation part accepts an operation instruction from a user. The operation part outputs an operation signal based on the operation of the user to the controller90, which will be described later.

The scanner230includes an automatic document feeder called an ADF (Auto Document Feeder) and a document image scanning device which is a scanner. The automatic document feeder conveys a document placed on a document tray by a conveyance mechanism and sends the document to the document image scanning device. The document image scanning device optically scans a document conveyed onto a contact glass by the automatic document feeder or a document placed on the contact glass by the user, and forms an image of reflected light from the document on a light receiving surface of a charge coupled device (CCD) sensor or the like to read the image of the document. The scanner230generates image data based on the result of reading by the document image scanning device.

The image forming section240forms an image on the recording material S based on image data. The image forming section240includes photosensitive drums241Y,241M,241C, and241K, charging sections242Y,242M,242C,242K, exposure sections243Y,243M,243C and243K, developing sections244Y,244M,244C and244K, and primary transfer rollers245Y,245M,245C and245K, corresponding to yellow (Y), magenta (M), cyan (C), and black (K). The image forming section240also includes an intermediate transfer belt246, a secondary transfer roller247, and a fixing section248.

Hereinafter, the photosensitive drums241Y,241M,241C, and241K are collectively referred to as “photoconductor drum241”. The charging sections242Y,242M,242C, and242K are collectively referred to as “charging section242”, and the exposure sections243Y,243M,243C, and243K are collectively referred to as “exposure section243”. Further, the developing sections244Y,244M,244C, and244K are collectively referred to as “developing section244”, and the primary transfer rollers245Y,245M,245C, and245K are collectively referred to as “primary transfer roller245”.

The photosensitive drum241is an image bearing member that carries a toner image thereon. The photosensitive drum241is rotated by driving of a photoreceptor drive motor (not illustrated). Around the photosensitive drum241, a charging section242, an exposure section243, and a developing section244are disposed in order from upstream to downstream in the rotation direction of the photosensitive drums241. The charging section242uniformly charges the photosensitive drum241.

The exposure section243includes a laser light source, a polygon mirror, and a lens. The exposure section243forms an electrostatic latent image by scanning and exposing the surface of the photosensitive drum241with a laser beam. The scanning exposure by the exposure section243is performed based on image data read by the scanner230or image data received from an external device.

The developing section244causes the toner of each color to adhere to the electrostatic latent image formed on the photosensitive drum241to perform development. Thus, a toner image is formed on the image bearing surface of the photosensitive drum241. That is, a yellow toner image is formed on the image bearing surface of the photosensitive drum241Y. A magenta toner image is formed on the image bearing surface of the photosensitive drum241M. A cyan toner image is formed on the image bearing surface of the photosensitive drum241C. A black toner image is formed on the image bearing surface of the photosensitive drum241K.

The intermediate transfer belt246is wound around a plurality of belt support rollers and formed in a loop shape. The primary transfer roller245, the secondary transfer roller247, a charge eliminating roller (not shown), and a cleaning unit249are disposed in a moving path of the intermediate transfer belt246.

An outer circumferential surface of the intermediate transfer belt246is an image bearing surface. The outer circumferential surface of the intermediate transfer belt246is in contact with the outer circumferential surface of the photosensitive drum241. The intermediate transfer belt246rotates in a direction opposite to the direction in which photosensitive drum241rotates. Specifically, the photosensitive drum241rotates in a counterclockwise direction inFIG.1, and the intermediate transfer belt246rotates in a clockwise direction inFIG.1.

The primary transfer roller245is disposed at a position facing the photosensitive drum241. The primary transfer roller245is disposed on the inner peripheral side of the intermediate transfer belt246, and sandwiches the intermediate transfer belt246between itself and the opposing photosensitive drum241.

The primary transfer roller245transfers the toner deposited on the image bearing surface of the photosensitive drum241to the image bearing surface of the intermediate transfer belt246by applying an electric charge having a polarity opposite to that of the toner to the intermediate transfer belt246. As a result, a color toner image in which the toner images of four colors are superimposed is formed on the image bearing surface of the intermediate transfer belt246.

The secondary transfer roller247collectively transfers the color toner image on the image bearing surface of the intermediate transfer belt246onto one recording surface of the recording material S. The secondary transfer roller247, and the belt support roller sandwich the intermediate transfer belt246. The position where the secondary transfer roller247and the belt support roller face each other is a transfer position where the toner image transferred on the image bearing surface of the intermediate transfer belt246is transferred to the recording material S.

In the rotational direction of the intermediate transfer belt246, the cleaning unit249is disposed upstream from the primary transfer rollers245and downstream from the charge eliminating roller (not shown). The cleaning unit249removes the toner remaining on the image carrying surface of the intermediate transfer belt246.

A fixing section248includes a fixing roller248aand a pressing roller248b. A heater is built in the fixing roller248a. The pressing roller248bis pressed against the fixing roller248a. As a result, the fixing roller248aand the pressing roller248bare press-contacted to each other, and a fixing nip portion is formed at this press-contacted portion. The recording material S is heated and pressurized when passing through the fixing nip portion. As a result, the toner image transferred to the recording material S is fixed.

The conveying portion250includes a plurality of conveying rollers54for conveying the recording material S along a predetermined conveying path. The conveying portion250conveys the recording material S supplied from the recording material conveying device400to the transfer position. Further, the conveying portion250conveys the recording material S after image formation to the post-processing device300.

[Post-Processing Device]

The recording material S on which the image has been formed by the image forming apparatus200is carried into the post-processing device300. The post-processing device300includes a plurality of post-processing units, a conveying portion350, an ejection portion351, and a sheet ejection tray352.

After receiving the post-processing job from the controller90, which will be described later, the post-processing device300performs predetermined post-processing in a post-processing unit specified by the post-processing job. Example of the post-processing include perforation processing, folding processing, foil stamping, binding, trimming processing, staple, gluing, binding and the like.

The conveying portion350includes a plurality of conveying rollers (not illustrated) for conveying the recording material S along a predetermined conveyance path. The conveying portion350conveys the recording material S supplied from the image forming apparatus200to a post-processing unit corresponding to the type of post-processing to be executed. Further, the conveying portion350conveys the recording material S after the post-processing and ejects the recording material S from the ejection portion351. The recording material S ejected from the ejection portion351is placed on the sheet ejection tray352.

<System Block Diagram>

Next, an example of the configuration of system of the image forming system10will be described referring toFIG.2.

FIG.2is a system block diagram of the image forming system10.

As illustrated inFIG.2, the image forming system10includes the controller90, a storage section98, a communication unit99, the operation display unit220, the scanner230, an image processing unit the recording material feeding section70, the image forming section240, the stiffness measuring device410, the recording material detector420, and the conveying portions51,52,53,250, and350. In the following description, the same configuration as that of the image forming system10illustrated inFIG.1will not be described.

The controller90includes, for example, a central processing unit (CPU)91, a read only memory (ROM)92, a random access memory (RAM)93, and the like.

The CPU91reads various processing programs stored in the ROM92, develops them in the RAM93, and centrally controls the operation of each section of the image forming system10according to the developed programs.

The ROM92stores various processing programs for controlling each section of the image forming system10, parameters and tables necessary for executing the programs, and various files.

The RAM93is, for example, a volatile semiconductor memory. In various types of processing executed by the CPU91, the RAM93forms a work area for temporarily storing various processing programs, input or output data, parameters and the like read from the ROM92.

The storage section98stores, for example, image data or the like received from an external device. In addition, the storage section98stores various processing programs executed by the CPU91, information regarding processing functions of the apparatus necessary for executing the programs, image date read by the scanner230, image date input from a client device (not shown) or the like, the stiffness of the recording material S measured by the stiffness measuring device410, and the like. The storage section98is, for example, a nonvolatile memory such as a hard disk drive (HDD), a solid state drive (SSD), or a flash memory.

The communication unit99includes a network interface card (NIC), a modem, and the like. The communication unit99connects the recording material feeding device100, the recording material conveying device400, the image forming apparatus200, the post-processing device300, and the stiffness measuring device410to a communication network such as a local area network (LAN) or a wide area network (WAN). The communication unit99transmits various data to an external information device. Further, the communication unit99receives various data from the external information device. The external information device is, for example, the client device.

As described above, the operation display unit220functions as the display part and the operation part. The display part displays various operation screens in accordance with a display control signal input from the controller90. The operation part receives various input operations performed by a user and outputs operation signals corresponding to the various input operations to the controller90.

The scanner230outputs a read analog image signal to the image processing unit80.

The image processing unit80includes a circuit for performing analog-digital conversion and a circuit for performing digital image processing, and the like. The image processing unit80performs A/D conversion processing on the analog image signal supplied from the scanner230to generate digital image data. The image processing unit80also analyzes a print job acquired from the external information device, and rasterizes each page of the document to generate digital image data. Furthermore, the image processing unit80performs image processing such as color conversion processing, correction processing according to initial setting or user setting, and compression processing on the image data as necessary. The correction according to the user setting is, for example, shading correction. The image processing unit80outputs the image data after the image processing to the image forming section240.

The stiffness measuring device410is disposed in the recording material conveying device400(seeFIG.1). Upon receipt of a stiffness measurement signal output from the controller90, the stiffness measuring device410measures the stiffness of the recording material S. The stiffness measuring device410outputs the measurement result to the controller90.

The recording material detector420is disposed in the recording material conveying device400(seeFIG.1). The recording material detector420detects that the recording material S is placed at the stiffness measurement position. The recording material detector420outputs the detection result to the controller90.

<Functional Configuration of Controller>

Next, the functional configuration of the controller90will be described with reference toFIG.3.

FIG.3is a functional block diagram of the controller90.

As illustrated inFIG.3, the controller90includes a sheet feed controller94, a conveyance controller95, a stiffness acquisition controller96, and an image formation controller97.

The sheet feed controller94controls supply of the recording material S from the recording material feeding section70to the conveying portion50in the recording material feeding device100. The sheet feed controller94supplies the recording material S to the conveying portion50in accordance with the conveyance control for the recording material S by the conveyance controller95.

The conveyance controller95controls driving of the conveying portions50,51,52,53,250, and350provided in the recording material feeding device100, the recording material conveying device400, the image forming apparatus200, and the post-processing device300. As a result, the recording material S is conveyed to each portion of the image forming system10.

Further, the conveyance controller95controls the conveyance mechanism such as the branching portion58of the recording material conveying device400to change the conveyance path of the recording material S.

When conveying a plurality of recording materials S in accordance with an image forming job, the conveyance controller95guides at least one recording material S to the second conveyance path42of the recording material conveying device400. The second conveyance path42is a path along which the second conveying portion52conveys the recording material S. Then, the conveyance controller95controls the second conveying portion52to dispose the recording material S at the stiffness measurement position in the second conveyance path42. The stiffness of the recording material S disposed at the stiffness measurement position is measured by the stiffness measuring device410.

The conveyance controller95corrects control parameters relating to the conveyance of the recording material S in accordance with the stiffness of the recording material S. A specific example of the control parameter related to conveyance is conveyance speed of the recording material S.

The stiffness acquisition controller96controls the stiffness measuring device410. Specifically, the stiffness acquisition controller96controls driving of a recording material pressing motor451(seeFIG.5), which will be described later, of the stiffness measuring device410. Furthermore, the stiffness acquisition controller96takes in a detection result of a pressing force detector432, which will be described later, of the stiffness measuring device410.

The image formation controller97controls image forming operation of the image forming section240. Furthermore, the image formation controller97determines the control parameters for image formation according to the stiffness of the recording material S measured by the stiffness measuring device410. Specific examples of the control parameters relating to the image formation include the charging potential by the charging section242, the transfer current supplied to the primary transfer roller245and the secondary transfer roller247, and the fixing temperature and the fixing pressure in the fixing section248.

<Configuration of Stiffness Measuring Device>

The operation of the stiffness measuring device410will be described with reference toFIGS.4and5.

FIG.4is a diagram illustrating a schematic configuration of the stiffness measuring device410.

As shown inFIG.4, the stiffness measuring device410is disposed in the second conveyance path42through which the second conveying portion52conveys the recording material S. In the second conveyance path42, the conveyance direction of the recording material S is the vertical direction Z. Therefore, the stiffness measuring device410measures the stiffness of the recording material S in the middle of being conveyed in a vertical direction Z.

Hereinafter, the conveyance direction of the recording material S is referred to as the vertical direction Z. The direction orthogonal to the recording surface of the recording material S conveyed on the second conveyance path42is a horizontal direction Y, and the direction orthogonal to the vertical direction Z and the horizontal direction Y is a recording material width direction X.

The stiffness measuring device410includes a recording material holding portion411that holds the recording material S and a stiffness measuring section412that measures the stiffness of the recording material S held by the recording material holding portion411.

The recording material holding portion411includes a pair of holding rollers421aand421b, a roller driving section422, and a biasing spring423.

The rotation axes of the pair of holding rollers421aand421bare parallel to the recording material width direction X. It is preferable that the pair of holding rollers421aand421balso serve as conveying rollers. The roller driving section422rotates the holding roller421a. The roller driving section422has a holding roller motor424and a gear train425for transmitting the rotation of the holding roller motor424to the holding roller421a.

The biasing springs423bias the holding roller421btoward the holding roller421a. The pair of holding rollers421aand421bhold the recording material S by applying a predetermined pressure to sandwich the recording material S. The pair of holding rollers421aand421bholds the recording material S in a posture such that the recording surface is substantially parallel to the vertical direction Z.

The above-described recording material detector420is disposed on the second conveyance path42. The recording material detector420detects a lower end of the recording material S when the recording material S is located at the stiffness measurement position. The recording material detector420outputs, to the controller90(seeFIG.2), the detection result, that is, the fact that the lower end of the recording material S has been detected. Thus, the controller90detects that the recording material S is disposed at the stiffness measurement position.

The stiffness measuring section412is disposed below the pair of holding rollers421aand421bin the recording material holding portion411. The stiffness measuring section412includes a pressing portion431, a pressing force detector432, a support mechanism433, a moving mechanism434, a home position sensor435, and a frame436. The support mechanism433, the moving mechanism434, and the home position sensor435are disposed in the frame436.

The pressing portion431presses the lower end portion of the recording material S. The pressing portion431includes a blade431aand a base431bthat is continuous with one end of the blade431ain the horizontal direction Y. The blade431ais formed in a long plate shape in the recording material width direction X so as to be able to come into contact with the entire width of the recording material S conveyed in the vertical direction Z. The blade431acomes into contact with a measurement point which is a position separated from the lower end of the recording material S toward the upper side in the vertical direction Z by a specific distance. That is, the measurement point is located on a lower side in the vertical direction than the portion of the recording material S held by the recording material holding portion411.

The pressing force detector432is connected to the surface of the pressing portion431opposite to the surface of the base431bcontinuous to the blade431a. The pressing force detector432detects a pressing force applied when the pressing portion431is pressed in the horizontal direction. That is, the pressing force detector432detects a pressing force required for the pressing portion431to press and bend the recording material S. As the pressing force detector432, for example, a load cell pressure sensor can be employed.

The support mechanism433supports the pressing portion431and the pressing force detector432so as to be movable in the horizontal direction Y. The support mechanism433includes a detector holding member441, an abutting member442, a worm gear443, and a biasing spring444. The detector holding member441and the abutting member442are attached to the frame436.

The detector holding member441is supported by the frame436so as to be movable in the horizontal direction Y. Further, the frame436is provided with a unillustrated locking portion for locking the rotation of the detector holding member441about the axis extending in the horizontal direction Y. The detector holding member441holds the pressing force detector432. A surface of the pressing force detector432opposite to the surface connected to the pressing portion431is connected to the detector holding member441.

The abutting member442faces the detector holding member441in the horizontal direction Y. Further, the abutting member442is fixed to the frame436. The abutting member442rotatably supports one end of the worm gear443.

The rotation axis of the worm gear443extends in the horizontal direction Y. The movement of the worm gear443in the horizontal direction Y is stopped by the abutting member442. The other end of the worm gear443is screwed into the detector holding member441. Accordingly, when the worm gear443rotates, the detector holding member441moves in the horizontal direction.

The biasing spring444is connected to the detector holding member441and the abutting member442. The detector holding member441is biased toward the abutting member442side. As the biasing member444, for example, a tension coil spring or a compression coil spring can be employed.

Backlash occurs between the detector holding member441and the worm gear443. Therefore, the detector holding member441is slightly movable in the horizontal direction Y regardless of the rotation of the worm gear443. According to the present embodiment, since the biasing spring444is provided, the detector holding member441does not move toward the abutting member442due to the influence of backlash. Thus, when the stiffness of the recording material S is measured, the detector holding member441and the pressing portion431are not displaced to the abutting member442side. As a result, the stiffness of the recording material S can be measured with high accuracy.

The moving mechanism434moves the pressing portion431in the horizontal direction Y via the support mechanism433. The moving mechanism434includes the recording material pressing motor451and a gear train452that transmits the rotation of the recording material pressing motor451to the worm gear443. The recording material pressing motor451may be, for example, a stepping motor.

The home position sensor435detects the home positions of the detector holding member441and the pressing portion431. The home position of the pressing portion431is a position at which the pressing portion431starts to contact the recording surface of the recording material S. The home position sensor435detects the home position of the pressing portion431from the position of the detector holding member441.

The home position of the pressing portion431varies depending on the thickness of the recording material S. The association between the thickness of the recording material S and the home position may be made by using table data previously stored in the storage section98. The pressing force detector432detects a pressing force received from the recording material S when the pressing portion431moves from the home position to the recording material S side in the horizontal direction Y by a predetermined amount.

The stiffness measuring device410includes a measuring section moving mechanism (not illustrated) that moves the stiffness measuring section412in the vertical direction Z. The measuring section moving mechanism corresponds to a pressing portion moving mechanism according to the present invention. The position of the pressing portion431in the vertical direction Z is changed in accordance with the length of the recording material S in the vertical direction. The length of the recording material S in the vertical direction is the length of the recording material S in the conveyance direction.

Specifically, the measuring section moving mechanism moves the stiffness measuring section412and the pressing portion431in the vertical direction Z so that the blade431acomes into contact with a position separated from the lower end of the recording material S by a specific distance upward in the vertical direction Z. As a result, when the stiffness of a plurality of types of recording materials S having different lengths in the vertical direction Z are measured, the measurement points at the same distances from the lower ends of the plurality of types of recording materials S can be pressed by the blade431a. As a result, the stiffness of a plurality of types of recording materials S having different lengths in the vertical direction Z can be measured under the same conditions.

The pressing portion moving mechanism according to the present invention may be a mechanism that moves the pressing portion431and the pressing force detector432on the detector holding member441. Furthermore, in the stiffness measuring device according to the present invention, the pair of holding rollers421aand421bmay be moved in the vertical direction so that the blade431acomes into contact with a position separated from the lower end of the recording material S upward in the vertical direction Z by a specific distance.

<Functional Configuration of Stiffness Measuring Device>

Next, a functional configuration of the stiffness measuring device410will be described with reference toFIG.5.

FIG.5is a block diagram illustrating a configuration example of a control system of the stiffness measuring device410.

As illustrated inFIG.5, the stiffness measuring device410includes the holding roller motor424, the pressing force detector432, the home position sensor435, and the recording material pressing motor451.

The holding roller motor424, the pressing force detector432, the home position sensor435, and the recording material pressing motor451are electrically connected to the controller90by wire or wirelessly.

The holding roller motor424, the pressing force detector432, the home position sensor435, and the recording material pressing motor451are controlled by the stiffness acquisition controller96of the controller90. In the case where the pair of holding rollers421aand421b(seeFIG.5) also serves as the conveying rollers, the holding roller motor424may be controlled by the conveyance controller95(seeFIG.3).

The stiffness measuring device410acquires the stiffness of the recording material S by operating as follows.

First, the stiffness acquisition controller96of the controller90receives a detection result of the recording material detector420(seeFIG.5) to detect the fact that the recording material S is disposed at the stiffness measurement position. Then, the stiffness acquisition controller96controls the driving of the holding roller motor424to cause the pair of holding rollers421aand421bto hold the recording material S disposed at the stiffness measurement position. At this time, the pair of holding rollers421aand421bhold the recording material S over the entire width in the recording material width direction X.

The recording material S held by the pair of holding rollers421aand421bis in a posture in which the recording surface is substantially perpendicular to the horizontal direction Y. Thus, the direction in which the recording material S is pressed is the horizontal direction Y, and the effect of gravity can be minimized when the recording material S is pressed. As a result, the stiffness of the recording material S can be measured with high accuracy.

Next, the stiffness acquisition controller96controls the driving of the recording material pressing motor451to move the pressing portion431and the pressing force detector432in the horizontal direction Y via the detector holding member441.

Accordingly, the pressing portion431starts to come into contact with the recording surface of the recording material S. At this time, the home position sensor435detects the position of the detector holding member441and outputs the detection result to the controller90.

Accordingly, the stiffness acquisition controller96detects the home positions of the pressing portion431and the detector holding member441.

Next, the stiffness acquisition controller96controls the driving of the recording material pressing motor451to move the pressing portion431from the home position to a predetermined distance. The predetermined distance is, for example, 3 mm. Thus, the pressing portion431presses and bends the recording material S. At this time, the pressing force detector432detects the pressing force received from the recording material S, and outputs the detection result to the controller90. Thus, the stiffness acquisition controller96acquires the pressing force detected by the pressing force detector432as the stiffness of the recording material S.

After the stiffness of the recording material S is acquired, the stiffness acquisition controller96releases the recording material S from the pressing state by the pressing portion431. That is, the stiffness acquisition controller96controls the driving of the recording material pressing motor451to move the pressing portion431to the abutting member442(seeFIG.5) side from the home position. Thus, the pressing state of the recording material S by the pressing portion431is released.

<Parameter Setting Processing>

Next, parameter setting processing of the image forming system10according to the present embodiment will be described with reference toFIG.6.

FIG.6is a flowchart showing the procedure of the parameter setting processing of the image forming system10.

First, when the print job is started, the conveyance controller95controls the driving of the conveying portion50to take out the recording material S designated by the print job from the recording material feeding section70. Then, the conveyance controller95controls the driving of the first conveying portion51and the second conveying portion52to convey the recording material S along the second conveyance path42of the recording material conveying device400(S1).

Next, when the lower end of the recording material S in the second conveyance path42is detected by the recording material detector420, the conveyance controller95controls the driving of the second conveying portion52to stop the conveyance of the recording material S (S2). Thus, the recording material S stops at the stiffness measurement position. Then, the stiffness acquisition controller96stops the driving of the holding roller motor424and causes the pair of holding rollers421aand421bto hold the recording material S arranged at the stiffness measurement position.

Next, the stiffness acquisition controller96operates the stiffness measuring section412of the stiffness measuring device410to obtain the stiffness of the recording material S (S3). At this time, the stiffness acquisition controller96controls driving of the recording material pressing motor451to cause the pressing portion431to press the recording material S in the horizontal direction Y. Then, the pressing force detector432detects the pressing force received from the recording material S pressed and bent by the pressing by the pressing portion431, and the stiffness acquisition controller96takes in the detection result. Thus, the stiffness of the recording material S is acquired.

Then, the conveyance controller95controls the driving of the second conveying portion52to eject the recording material S whose stiffness has been measured from the ejection portion56(S4). At this time, the stiffness acquisition controller96drives the holding roller motor424to release the holding of the recording material S by the pair of holding rollers421aand421b.

Next, the controller90sets the control parameters based on the stiffness of the recording material S (S5). The association between the stiffness of the recording material S and the control parameters may be made by using table data previously stored in the storage section98. That is, the controller90reads, from the storage section98, the control parameters corresponding to the measured stiffness of the recording material S.

The control parameters to be set includes at least one of a conveyance parameter of the recording material, a curl correction parameter of the recording material, an image forming parameter, and a post-processing parameter.

Specific examples of the conveyance parameter of the recording material include the conveyance speed. Specific examples of the curl correction parameter of the recording material include the pressure applied to the recording material by the curl correction roller and the contact time between the curl correction roller and the recording material. Specific examples of the image forming parameters include the charging potential by the charging section242, the transfer current supplied to the primary transfer roller245and the secondary transfer roller247, and the fixing temperature and the fixing pressure in the fixing section248. Specific examples of the post-processing parameter include the driving pressure for performing staple processing, the driving torque for performing sheet folding processing, and the like.

The conveyance parameter and the curl correction parameter are parameters set by the conveyance controller95. The image forming parameter is a parameter set by the image formation controller97. The post-processing parameter is a parameter set by a non-illustrated post-processing controller included in the controller90. The control parameter set in step S5may be a control parameter other than the control parameters mentioned here.

2. Second Embodiment

A stiffness measuring device according to a second embodiment of the present invention will be described below with reference toFIG.7.

FIG.7is a diagram showing a schematic configuration of the stiffness measuring device according to the second embodiment.

As illustrated inFIG.7, in a stiffness measuring device470according to the second embodiment, a second conveying portion52is disposed in a second conveyance path42through which the recording material S is conveyed. The stiffness measuring device470measures the stiffness of a recording material S being conveyed in the vertical direction Z. The stiffness measuring device470includes a recording material holding portion411for holding the recording material S, and stiffness measuring sections412A and412B for measuring the stiffness of the recording material S held by the recording material holding portion411.

Since the configuration of the recording material holding portion411is the same as that of the recording material holding portion411according to the first embodiment, descriptions thereof will be omitted. The stiffness measuring sections412A and412B face each other in the horizontal direction Y with the recording material S disposed at the stiffness measurement position therebetween. Since the configurations of the stiffness measuring sections412A and412B are the same as those of the stiffness measuring section412according to the first embodiment, the description thereof will be omitted.

The recording material S has a first recording surface and a second recording surface. The first recording surface is, for example, a front surface, and the second recording surface is, for example, a back surface. A stiffness measuring section412A faces the second recording surface of the recording material S. The stiffness measuring section412A presses the second recording surface of the recording material S to measure the stiffness of the first recording surface of the recording material S. A pressing portion431of the stiffness measuring section412A corresponds to a first pressing portion according to the present invention. A pressing force detector432of the stiffness measuring section412A corresponds to a first stiffness acquiring section according to the present invention.

A stiffness measuring section412B faces the first recording surface of the recording material S. The stiffness measuring section412B presses the first recording surface of the recording material S and measures the stiffness of the second recording surface of the recording material S. A pressing portion431of the stiffness measuring section412B corresponds to a second pressing portion according to the present invention. A pressing force detector432of the stiffness measuring section412B corresponds to a second stiffness acquiring section according to the present invention.

The stiffness measuring device470according to the second embodiment can measure the stiffness of the first recording surface and the second recording surface of the recording material S disposed at the stiffness measurement position. Therefore, for example, it is effective in the case of double-sided printing.

When it is desired to measure the stiffness of the first recording surface and the second recording surface of the recording material S by one stiffness measuring section, it is necessary to reverse the recording material S and convey it to the stiffness measurement position again. On the other hand, the stiffness measuring device470according to the second embodiment does not needs to reverse the recording material S, and can shorten the time required to measure the stiffness of the first recording surface and the second recording surface of the recording material S.

3. Modification Examples

In the stiffness measuring devices410and470of the first and second embodiments the pressing portion431is configured to press the measurement point of the recording material S. However, the pressing portion according to the present invention may be connected to the measurement point of the recording material S to pull the recording material S. The stiffness acquiring section in this case detects the reaction force when the recording material S is pulled. The reaction force when the recording material S is pulled may be rephrased as tensile force. Also in this case, the stiffness of the recording material S can be measured. Examples of the pressing portion connected to the measurement point of the recording material include a pressing portion formed into a frame shape having a through hole through which the lower end portion of the recording material passes and a pressing portion having a suction portion for sucking the recording material.

Further, the pressing portion according to the present invention may be configured to be capable of pressing the measurement point of the recording material S and capable of pulling the measurement point of the recording material S. The stiffness acquiring section in this case detects a reaction force generated when the recording material S is pressed and a reaction force generated when the recording material S is pulled. As a result, the stiffness of the first recording surface and the second recording surface of the recording material S can be measured using one pressing portion without reversing the recording material S.

4. Summary

As described above, the stiffness measuring device410according to the first embodiment includes the recording material holding portion411, the pressing portion431, and the pressing force detector432. The recording material holding portion411holds the recording material S in a posture in which the recording surface is substantially parallel to the vertical direction Z. The pressing portion431presses the measurement point located on a lower side in the vertical direction Z than the portion of the recording material S held by the recording material holding portion411. The pressing force detector432measures the reaction force obtained when the measurement point is pressed by the recording material holding portion411, and acquires the measured reaction force as the stiffness of the recording material. The recording material holding portion411corresponds to the holding section according to the present invention, and the pressing force detector432corresponds to the stiffness acquiring section according to the present invention.

As a result, the stiffness of the recording material S can be acquired in a state in which the effect of gravity is minimized. As a result, the stiffness of the recording material S can be measured with high accuracy.

Further, the measurement point according to the above-described first embodiment is an end portion of the recording material S. Thus, the effect of the gravity can be minimized.

Further, the pressing portion431according to the above-described first embodiment presses the measurement point in the horizontal direction Z.

Accordingly, the pressing portion431can reliably press the recording material S whose recording surface is substantially parallel to the vertical direction Z. The pressing force detector432can accurately acquire the relationship between the pressing distance to the recording material S and the reaction force of the recording material S. As a result, the pressing force detector432can accurately detect the reaction force of the recording material S.

In addition, the recording material holding portion411according to the above-described first embodiment stops the recording material S.

Accordingly, the reaction force of the recording material S can be accurately detected.

In addition, the stiffness measuring device410according to the above-described first embodiment includes the pressing portion moving mechanism that moves the pressing portion431. The position of the pressing portion431in the vertical direction Z is changed in accordance with the length of the recording material S in the vertical direction Z.

Thus, when the stiffness of a plurality of types of recording materials S having different lengths in the vertical direction Z is measured, the measurement points at the same distance from the lower ends of the plurality of types of recording materials S can be pressed by the pressing portion431. As a result, the stiffness of a plurality of types of recording materials S having different lengths in the vertical direction Z can be measured under the same conditions.

In addition, the pressing portion according to the above-described modification example may press the measurement point or may be connected to the measurement point and pull the measurement point. The stiffness acquiring section according to the modification example measures the reaction force in each of the case where the pressing portion presses the measurement point and the case where the pressing portion pulls the measurement point, and acquires the stiffness of the both recording surfaces of the recording material.

Thus, the stiffness of the both recording surfaces of the recording material can be measured by using one pressing portion without reversing the recording material.

In addition, the stiffness measuring device470according to the above-described second embodiment includes the pressing portion431of the stiffness measuring section412A which presses the first recording surface of the recording material S and the pressing portion431of the stiffness measuring section412B which presses the second recording surface of the recording material S. Further, the stiffness measuring device470includes the pressing force detector432of the stiffness measuring section412A that measures the reaction force via the pressing portion431of the stiffness measuring section412A, and the pressing force detector432of the stiffness measuring section412B that measures the reaction force via the pressing portion431of the stiffness measuring section412B. Thus, the stiffness of the first recording surface and the stiffness of the second recording surface of the recording material S are acquired. The pressing portion431of the stiffness measuring section412A corresponds to the first pressing portion according to the second embodiment of the present invention, and the pressing portion431of the stiffness measuring section412B corresponds to the second pressing portion according to the second embodiment of the present invention. The pressing force detector432of the stiffness measurement unit412A corresponds to the first stiffness acquiring section according to the present invention, and the pressing force detector432of the stiffness measuring section412B corresponds to the stiffness acquisition section according to the present invention.

Thus, the stiffness of the first recording surface and the stiffness of the second recording surface can be acquired without reversing the recording material S. As a result, the time required for measuring the stiffness of the first recording surface and the second recording surface of the recording material S can be shortened.

In addition, the image forming system10according to the above-described first embodiment includes the image forming section240which forms an image on the recording material S, the recording material feeding section70which can store the recording material, and the second conveyance path42which is provided between the recording material feeding section70and the image forming section240. The image forming system10further includes a stiffness measuring device410that is disposed in the second conveyance path42and measures the stiffness of the recording material S, and the controller90that sets the image forming parameter in accordance with the measurement result of the stiffness measuring device410. The stiffness measuring device410includes the recording material holding portion411, the pressing portion431, and the pressing force detector432. The recording material holding portion411holds the recording material S in a posture in which the recording surface is substantially parallel to the vertical direction Z. The pressing portion431presses the measurement point located on a lower side in the vertical direction Z than the portion of the recording material S held by the recording material holding portion411. The pressing force detector432measures the reaction force obtained when the measurement point is pressed by the recording material holding portion411, and acquires the measured reaction force as the stiffness of the recording material. The recording material feeding section70corresponds to the recording material storage portion according to the present invention, and the second conveyance path42corresponds to the recording material conveyance path according to the present invention.

As a result, the stiffness of the recording material S can be acquired in a state in which the effect of gravity is minimized. As a result, the stiffness of the recording material S can be measured with high accuracy.

In addition, in the stiffness measuring method according to the above-described first embodiment, the recording material S in a posture in which the recording surface is substantially parallel to the vertical direction is held by the recording material holding portion411, and the pressing portion431presses the measurement point located on a lower side in the vertical direction Z than the portion of the recording material S held by the recording material holding portion411. Then, the pressing force detector432measures the reaction force obtained when the measurement point is pressed by the pressing portion431, and acquires the measured reaction force as the stiffness of the recording material.

As a result, the stiffness of the recording material S can be acquired in a state in which the effect of gravity is minimized. As a result, the stiffness of the recording material S can be measured with high accuracy.

The embodiments of the stiffness measuring device and the image forming system according to the present invention have been described above including the effects thereof. However, the stiffness measuring device and the image forming system of the present invention are not limited to the above-described embodiments, and various modification implementations are possible within a scope that does not depart from the gist of the invention described in the claims.

Furthermore, the above-described embodiments have been described in detail in order to describe the present invention in an easy-to-understand manner, and is not necessarily limited to one including all of the described configurations. Furthermore, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added with the configuration of another embodiment. In addition, some of the configurations of each embodiment may be added to, omitted from, and replaced with other configurations.

For example, in the image forming system10of the above-described embodiments, the stiffness measuring device410is provided in the recording material conveying device400. However, the position where the stiffness measuring device according to the present invention is provided can be appropriately set as long as it is on the upstream of the image forming section in the conveyance direction of the recording material. The stiffness measuring device according to the present invention may be provided in, for example, the image forming apparatus200or the recording material feeding device100.

DESCRIPTION OF THE REFERENCE NUMERALS

10—image forming system,41—first conveyance path,42—second conveyance path,43—third conveyance path,50—conveying portion,51—first conveying portion,52—second conveying portion,53—third conveying portion,54—conveying rollers,55—carry-in port,56—ejection portion,57—carry out port,58—branching portion,70—recording material feeding section,80—image processing unit,90—controller,91—CPU,92—ROM,93—RAM,94—sheet feed controller,95—conveyance controller,96—stiffness acquisition controller,97—image formation controller,98—storage section,99—communication unit,100—recording material feeding device,200—image forming apparatus,220—operation display unit,230—scanner,240—image forming section,300—post-processing device,400—recording material conveying device,410,470—stiffness measuring device,411—recording material holding portion,412,412A,412B—stiffness measuring section,420—recording material detector,421a,421b—holding roller,422—roller driving section,424—holding roller motor,425—gear train,431—pressing portion,431ablade,431b—base,432—pressing force detector,433—support mechanism,434—moving mechanism,435—home position sensor,436—frame,441—detector holding member,442—abutting member,443—worm gear,451—recording material pressing motor,452—gear train