JP2018060187A - Conveyance device, transfer device, image formation apparatus, position control method of rotor in conveyance device and position control program of rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveyance device for conveying a sheet-like conveyance object material which can enhance the reduction rate of shock jitter due to the contact/separation operation of two rotors without reducing the conveyance efficiency.SOLUTION: A conveyance device which conveys a sheet-like conveyance object material between a first rotor provided in a rotatable manner and a second rotor provided in a rotatable manner and arranged so as to face the first rotor includes a contact/separation mechanism which can move at least a surface of at least any of the first rotor and the second rotor between a contact position where the first rotor and the second rotor contact the conveyance object material and a separation position where the first rotor is separated from the second rotor in a facing region where the first rotor and the second rotor face each other. The contact/separation mechanism moves at least the surface of any of the first rotor and the second rotor to any position between the separation position and the contact position from the separation position at the first speed, and then moves the surface to the contact position from the any position at the second speed slower than the first speed when moving the surface in the direction from the separation position to the contact position.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a conveying device that conveys a sheet-like material to be conveyed, a transfer device that conveys the material to be conveyed, an image forming apparatus, a position control method for a rotating body in the conveying device, and a position control program for the rotating body.

  In an image forming apparatus having two rotating bodies that contact an image carrier such as an intermediate transfer belt to form a transfer nip, linear density unevenness called a shock jitter is caused when the recording medium passes through the transfer nip. Sometimes. This density unevenness is caused when the load on the image carrier suddenly changes when the paper enters or leaves the transfer nip, and the linear velocity of the image carrier is instantaneously greatly changed.

  Therefore, in the configuration of Patent Document 1, the amount of shock jitter is reduced by adjusting the distance between the intermediate transfer belt and the secondary transfer roller at the time of contact according to the detected sheet thickness with respect to the set sheet thickness. Had gone.

  According to the configuration of Patent Document 1, it can be expected to suppress the rotational load of the image carrier when the recording medium enters the transfer nip, but both the reduction of the rotational load and the transport efficiency of a plurality of transported materials are achieved. I couldn't.

  In addition, this problem is not limited to the transfer device, and suppresses speed fluctuations that occur in at least one of the rotating bodies due to an impact when the material to be conveyed enters the facing region between the first rotating body and the second rotating body. If it is an effective rotating body drive device, it can occur similarly.

  Therefore, in view of the above circumstances, the present invention provides a transport apparatus for transporting a sheet-like material to be transported, which can increase the reduction rate of the rotational load due to the contact / separation operation of two rotating bodies without reducing the transport efficiency. The purpose is to provide.

In order to solve the above-described problem, according to one aspect of the present invention, between a first rotating body provided rotatably and a second rotating body provided rotatably and opposed to the first rotating body. A conveying device that conveys a sheet-like material to be conveyed,
In a facing region where the first rotating body and the second rotating body face each other, a contact position where the first rotating body and the second rotating body are in contact with the material to be conveyed, the first rotating body, and the A contact / separation mechanism capable of moving at least a surface of at least one of the first rotating body and the second rotating body between the second rotating body and a separated position where the second rotating body is separated;
With
The contacting / separating mechanism is
When moving at least the surface of at least one of the rotating bodies from the separated position toward the contact position,
After moving from the separated position to an arbitrary position between the separated position and the contact position at a first speed, the contact is made from the arbitrary position at a second speed that is lower than the first speed. Move it to a position,
A conveying device is provided.

  According to one aspect, in a transport device that transports a sheet-like material to be transported, the reduction rate of shock jitter due to the contact / separation operation of two rotating bodies can be increased without reducing transport efficiency.

1 is a schematic view illustrating the configuration of an image forming apparatus according to an embodiment of the invention. Schematic which illustrates the structure of a conveying apparatus provided with the contacting / separating mechanism which concerns on 1st Embodiment. The figure which illustrates the structure of the contacting / separating mechanism which concerns on 1st Embodiment. The drive control block diagram of the conveying apparatus which concerns on 1st Embodiment. The figure which shows the positional relationship of a separation position, a preliminary | backup position, a contact position, and a press contact position of an opposing roller and a secondary transfer roller. 6 is a timing chart showing the positions of two rotating bodies in a contact / separation operation when transporting sheets continuously. 7 is a control flowchart in the transport apparatus according to the first embodiment. 6 is a timing chart showing the positions of two rotating bodies in a contact / separation operation when transporting sheets of different thicknesses. Schematic which illustrates the structure of a conveying apparatus provided with the contacting / separating mechanism which concerns on 2nd Embodiment. FIG. 10 is a schematic view illustrating the internal configuration of a direct transfer image forming apparatus according to a third embodiment. FIG. 10 is a schematic view illustrating the internal configuration of an inkjet image forming apparatus according to a fourth embodiment.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

<Configuration of image forming apparatus>
FIG. 1 is a schematic view illustrating the configuration of an image forming apparatus 90 according to an embodiment of the invention.

  The image forming apparatus 90 includes a photosensitive member 10, a charging device 11, an exposure device 12, a developing device 13, an intermediate transfer belt 20, a secondary transfer roller 30, a fixing device 40, an automatic document feeder (ADF) 50, a reading device 51, and the like. And a multifunction machine that prints and outputs an image on the paper P stored in the paper tray 71. Note that the paper P is an example of a sheet-like material to be conveyed.

  In the image forming apparatus 90, when printing an image on the paper P, first, the charging device 11 uniformly charges the surface of the rotating photoreceptor 10, and the image read by the reading device 51 on the document set on the ADF 50. Based on the data and the like, the exposure device 12 exposes the surface of the photoreceptor 10 to form an electrostatic latent image.

  Next, the developing device 13 containing a developer containing toner therein develops the electrostatic latent image on the surface of the photoreceptor 10 to form a toner image. The image forming apparatus 90 includes a plurality of photoreceptors 10, a developing device 13, and the like. After forming toner images of different colors, the toner images are transferred onto the rotating intermediate transfer belt 20 in an overlapping manner. The photoconductor 10, the charging device 11, the exposure device 12, the developing device 13, and the like function as an image forming unit.

  The toner image transferred to the intermediate transfer belt 20 is transferred from the paper tray 71 to the paper transport roller 72 in the secondary transfer section where the intermediate transfer belt 20 and the secondary transfer roller 30 transport the paper P while sandwiching the paper P between the opposing areas. Is secondarily transferred to the sheet P conveyed by the above. The paper P onto which the toner image has been transferred is further conveyed, heated and pressed by the fixing device 40 to fix the toner image, and is discharged to the paper discharge tray 73.

  After the toner image is transferred to the intermediate transfer belt 20, the toner remaining on the surface is removed by the cleaning device 14 to prepare for the next image formation.

<Configuration of Conveying Device Including Intermediate Transfer Belt and Secondary Transfer Roller>
FIG. 2 is a schematic view illustrating the configuration of the transport apparatus 80 including the contact / separation mechanism 60 according to the first embodiment. Specifically, FIG. 2 is a schematic view illustrating the configuration of the intermediate transfer belt 20 and the secondary transfer roller 30 according to the first embodiment and the control thereof.

  The intermediate transfer belt 20 is stretched over a plurality of rollers 21, 22, 23, 24, etc., and is driven by a driving roller 21 rotated by a driving roller motor 25 to rotate in the direction of the arrow in the figure.

  The drive roller 21 is driven to rotate at a predetermined rotation speed by a drive roller motor 25 whose rotation speed is feedback controlled by the control unit 100, thereby rotating the intermediate transfer belt 20. A drive motor encoder 26 is provided on the rotation shaft of the drive roller motor 25, and the control unit 100 can obtain the rotation speed of the drive roller 21 from the detection result of the drive motor encoder 26.

  The intermediate transfer belt 20 is an example of a first rotating member, and the intermediate transfer belt 20 is disposed between the photosensitive member 10 (10K, 10C, 10M, 10Y) and the primary transfer roller 15 (15K, 15C, 15M, 15Y). A toner image formed on the surface is transferred. Further, the toner image formed on the intermediate transfer belt 20 is transferred between the secondary transfer roller 30.

  The secondary transfer roller 30 is an example of a second rotating body, and is configured, for example, by covering an outer periphery of a metal core such as SUS with an elastic material such as urethane whose resistance value is adjusted by a conductive material. ing. The counter roller 24 moves the intermediate transfer belt 20 toward the secondary transfer roller 30 at a position facing the secondary transfer roller 30 so that the sheet P can be pressed against the intermediate transfer belt 20 and the secondary transfer roller 30. Has been. A position where the intermediate transfer belt 20 and the secondary transfer roller 30 sandwich the paper P in the conveyance path is referred to as a facing area.

  The counter roller 24 is provided so as to be movable between a position where the intermediate transfer belt 20 is pressed against the paper P between the secondary transfer roller 30 and a position where the intermediate transfer belt 20 is separated from the paper P. Yes. The opposing roller 24 is a part of a secondary transfer portion that performs secondary transfer, and contacts and separates at least the surface of the intermediate transfer belt 20 that is the first rotating body and the secondary transfer roller 30 that is the second rotating body. It also functions as a part of the contacting / separating mechanism 60.

  The secondary transfer roller 30 is rotated in the direction of the arrow in the figure by a secondary transfer motor 31. The secondary transfer roller 30 is rotationally driven at a predetermined rotational speed by a secondary transfer motor 31 whose rotational speed is feedback controlled by the control unit 100. A paper timing sensor for paper conveyance is provided on the paper conveyance path.

  A secondary transfer encoder 32 is provided on the rotation shaft of the secondary transfer motor 31, and the control unit 100 can obtain the rotational speed of the secondary transfer roller 30 from the detection result of the secondary transfer encoder 32.

  Further, for example, a writing start signal for instructing start of writing on the photoconductor 10 is input to the control unit 100 from the main control unit 91 (see FIG. 9) of the image forming apparatus 90. The control unit 100 defines the movement start timing for preliminary approach, the movement start timing for contact, the separation start timing, and the like as time elapses from the assertion of the write start signal. Note that the signal that triggers the start of preliminary approach movement, the start of contact movement, the start of separation, etc. is not limited to the writing start signal, and any signal can be used as long as it can determine the timing of sheet conveyance.

  The contact / separation mechanism 60 performs intermediate transfer between a position where the intermediate transfer belt 20 and the secondary transfer roller 30 are pressed against the sheet P and the secondary transfer is performed, and a position where the intermediate transfer belt 20 is separated from the sheet P. This is a mechanism for contacting and separating the belt 20 and the secondary transfer roller 30. When the sheet P does not exist between the intermediate transfer belt 20 and the secondary transfer roller 30, a position where the intermediate transfer belt 20 and the secondary transfer roller 30 are separated by more than the thickness of the sheet P is a separation position. The separation position is arbitrarily set. The position where the intermediate transfer belt 20 and the secondary transfer roller 30 are pressed against the paper P and the secondary transfer is performed is called a pressure contact position.

  The contact / separation mechanism 60 includes a contact / separation motor 61, a counter roller 24, and an HP (Home Position) sensor 65. The facing roller 24 is a roller that urges the intermediate transfer belt 20 toward the secondary transfer roller 30. The contact / separation motor 61 is a motor that drives the contact roller 24 to contact / separate the intermediate transfer belt 20 with respect to the secondary transfer roller 30. The contact / separation motor 61 is controlled by the control unit 100. The HP sensor 65 is a sensor that outputs a signal when the facing roller 24 is in a predetermined position. The contact / separation mechanism 60 further includes a contact / separation roller 63 and the like, which will be described later with reference to FIG.

  The control unit 100 controls the contact / separation motor 61 based on the output of the HP sensor 65.

  Further, the control unit 100 includes a memory (NVRAM 104, 105, etc., see FIG. 4) as a storage unit, and the control unit 100 determines the secondary transfer motor 31 based on data stored in the memory (NVRAM 104). The controller 100 controls the rotational speed and the conveying speed, and the controller 100 controls the position of the opposing roller 24 of the contact / separation mechanism 60 based on the data stored in the memory (NVRAM 105) and the secondary transfer of the intermediate transfer belt 20. The position with respect to the transfer roller 30 is controlled. The contact / separation mechanism 60 will be described below.

<Configuration example of contact / separation mechanism>
FIG. 3 is a diagram illustrating the configuration of the contact / separation mechanism 60 according to the first embodiment. FIG. 3A illustrates the counter roller 24 moving in the direction of the secondary transfer roller 30 and the intermediate transfer belt 20 being moved. FIG. 3B shows a state in which the secondary transfer roller 30 is in contact, and FIG. 3B shows a state in which the opposing roller 24 moves in the separation direction and the intermediate transfer belt is separated from the secondary transfer roller 30.

  The opposing roller 24 is urged toward the secondary transfer roller 30 by an elastic body (not shown) such as a spring. As shown in FIG. 3, an eccentric cam 62 is provided on the rotation shaft of the opposing roller 24, and the contact / separation motor 61 connected to the eccentric cam 62 via a belt 64 rotates, so that the opposing roller 24 passes through the opposing roller 24. Thus, the intermediate transfer belt 20 and the secondary transfer roller 30 come in contact with and separate from each other.

  For example, as shown in FIG. 3A, the eccentric cam 62 is rotated via the belt 64 in conjunction with the rotation of the contact / separation roller 63 that is rotationally driven by the contact / separation motor 61, so that the eccentric cam 62 is By setting the angle, the facing roller 24 moves in the approaching direction, and the intermediate transfer belt 20 contacts the secondary transfer roller 30.

  Further, as shown in FIG. 3B, the eccentric cam 62 connected to the opposing roller 24 is rotated via the belt 64 by the contact / separation roller 63 driven to rotate by the contact / separation motor 61, and the eccentric cam 62 is eccentric. By setting the cam 62 at a predetermined angle, the opposing roller 24 and the secondary transfer roller 30 are separated from each other.

  As shown in FIGS. 3A and 3B, the HP sensor 65 is provided, for example, on a part of the eccentric cam 62. When the HP sensor 65 is detected, it means that the rotation of the eccentric cam 62 is at a predetermined rotation angle. For example, it can be seen that the facing roller 24 is located at a predetermined position.

  The position of the intermediate transfer belt 20 with respect to the secondary transfer roller 30 is obtained by the control unit 100 based on the rotation amount of the contact / separation motor 61 using the detection result by the HP sensor 65.

  The secondary transfer roller 30 and the contact / separation roller 63 and the counter roller 24 included in the contact / separation mechanism 60 of FIG. 3 are assumed to be general cylindrical or columnar rollers having a circular or substantially circular outer periphery. .

  The structure of the control part of the following conveying apparatus 80 is demonstrated below.

<Drive control block>
FIG. 4 is a drive control block diagram of the transport device 80 according to an embodiment of the present invention.

  As shown in FIG. 4, the secondary transfer device, which is an example of the conveying device 80 that performs the contact / separation operation, includes a control unit 100, a drive roller motor 25, a drive motor encoder 26, and a secondary as parts related to drive control. A transfer motor 31, a secondary transfer encoder 32, a contact / separation motor 61, and an HP sensor 65 are provided. The control part 100 is a control board provided with CPU, FPGA, etc., for example.

  The drive roller motor 25 rotationally drives a drive roller 21 (see FIG. 2) that rotationally drives the intermediate transfer belt 20. Further, the rotational speed of the drive roller motor 25 and the moving speed of the intermediate transfer belt 20 can be obtained from the detection result of the drive motor encoder 26. The driving roller 21 may be controlled based on the moving speed of the intermediate transfer belt 20 detected by a scale sensor that detects a belt scale provided on the intermediate transfer belt 20.

  The transport roller motor 74 is a motor for feeding and transporting the paper P, which is a transported material, and rotationally drives a transport roller 72 (see FIG. 1) that transports the paper P.

  The secondary transfer motor 31 is a motor for rotating the secondary transfer roller 30. Further, the rotational speed of the secondary transfer roller 30 can be obtained from the detection result of the secondary transfer encoder 32.

  The contact / separation motor 61 is an example of a movement drive unit, and is a motor that moves the opposing roller 24 so as to approach and separate from the secondary transfer roller 30.

  The drive roller motor 25, the secondary transfer motor 31, and the contact / separation motor 61 are preferably stepping motors (STM), for example.

  The HP sensor 65 is an example of a position detection sensor, and outputs a predetermined signal when the opposing roller 24 is at a predetermined position that serves as a reference in the approach / separation direction in the contact / separation mechanism 60 (see FIG. 5).

  The control unit 100 includes a CPU 101, a ROM 102, a RAM 103, NVRAMs 104 and 105, a timer 106, motor drivers 107, 108, 109, 110, and the like.

  A CPU (Central Processing Unit) 101 controls the conveyance while grasping the rotation state with the encoders 26 and 32, and controls the approach / separation operation using the detection result by the HP sensor 65.

  A ROM (Read Only Memory) 102 stores a program written in a code readable by the CPU 101 and various data used when the program is executed. A RAM (Random Access Memory) 103 is a working memory for the CPU 101, and develops contact / separation information as required by the CPU 101, for example.

  The timer 106 measures a predetermined time such as a pause time Ma and a pressure contact time La.

  The motor driver 107 controls driving of the driving roller motor 25 in accordance with a printing instruction.

  The motor driver 108 drives and controls the secondary transfer motor 31.

  The motor driver 109 controls the drive so that the facing roller 24 moves at a predetermined speed and direction by rotating the contact / separation motor 61 according to the approaching state of the sheet to the facing area.

  For example, the contact / separation motor 61, which is a stepping motor, is set with the number of pulses per motor rotation and unit magnification, and “1” indicating how much the opposing roller 24 moves per pulse of the motor shaft of the contact / separation motor 61. It is assumed that the “movement amount per pulse” is associated in advance and controlled by the motor driver 109. Alternatively, the “movement amount per rotation” of how much the opposing roller 24 moves per rotation of the motor shaft of the contact / separation motor 61 may be controlled in association with each other.

  The motor driver 110 drives and controls the conveyance roller motor 74.

  An NVRAM (Non-volatile RAM) 104 is a memory for transfer and conveyance, and stores transfer conditions, a belt conveyance speed, and the like in advance.

  The NVRAM 105 is a memory for the contact / separation operation, and has a plurality of types according to the type of the material to be conveyed, the pressure contact time La, the movement speeds V1 and V2 when approaching, the preliminary approach movement amount Y1, and the separation speed. V3, pause time Ma, etc. are stored. It is not necessary to store all these pieces of information, and it is only necessary to store information that allows a contact / separation operation described later. Further, these pieces of information may be held further in accordance with the transport speed of the transported material and the transport speed of the intermediate transfer belt 20.

  The preliminary approaching movement amount Y1 is an arbitrary position between a predetermined separation position and an arbitrary position between the separation position and the pressure contact position and a preliminary position where the intermediate transfer belt 20 and the secondary transfer roller are separated from each other. This corresponds to a specific movement amount associated with the distance (see FIG. 5). For example, in the contact / separation motor 61, a specific movement amount is set by designating a pulse, a unit magnification, and a rotation amount. The pressure contact time La is a time during which the opposing roller 24 is located at the pressure contact position.

  These pieces of information are retrieved when the CPU 101 requests and accesses the NVRAMs 104 and 105.

  In FIG. 4, only one CPU is collectively shown as the main control unit. However, separate CPUs may be provided for paper conveyance control and for approach / separation control.

<Intermediate transfer belt position>
FIG. 5 is a diagram illustrating the positional relationship between the separation position, the preliminary position, the contact position, and the pressure contact position between the opposing roller 24 and the secondary transfer roller 30.

  5, (a) is a predetermined separation position of the opposing roller 24, (b) is a preliminary position PA for thick paper, (c) a preliminary position PB for thin paper, and (d) is a contact position for thick paper. CA, (e) shows the contact position CB in the case of thin paper, and (f) shows the press contact position. In FIG. 5, the position of the opposing roller 24 as the contact / separation mechanism 60 of the intermediate transfer belt 20 that is the first rotating body will be described.

  The approaching movement in which the opposing roller 24 approaches the secondary transfer roller 30 and the contact roller 24 is further pushed after the contact to increase the contact pressure between the intermediate transfer belt and the paper P, and the secondary transfer roller and the paper P. The movement to the pressure contact that is the movement of the opposing roller 24 is collectively referred to as movement in the approaching direction.

  The HP sensor 65 outputs a detection signal when the facing roller 24 is at a predetermined position detected by the HP sensor. Examples of the output of the detection signal include that the signal is asserted, becomes H level, becomes active, and the like.

  Preliminary positions PA and PB shown in FIGS. 5B and 5C are speed switching positions at which the speed of the facing roller 24 is switched from the first movement speed to the second movement speed in the contact / separation mechanism 60. . The preliminary positions PA and PB are arbitrary positions at an arbitrary distance from a predetermined separation position, and are specific movements that are appropriately changed and set according to the type and conveyance speed of the paper P that is the material to be conveyed. It is defined by the amount (preliminary approach movement amounts Y1, Y2 (see FIG. 8)). Further, as described above, the preliminary position is a position where the intermediate transfer belt 20 and the secondary transfer roller 30 are separated from each other.

  The contact positions CA and CB shown in FIGS. 5D and 5E indicate positions where the opposing roller 24 starts to contact with the paper P (paper type A, paper type B) or starts to separate. This contact position varies depending on the thickness of the paper. At this contact position, the contact pressure applied to the paper P by the intermediate transfer belt 20 and the secondary transfer roller 30 is low.

  The press-contact position shown in FIG. 5F indicates the position of the press-contact state in which an image is transferred on the paper P and is in contact with a predetermined pressure. FIG. 5F shows an example of the paper type B (thin paper). The press contact position shown in FIG. 5F is such that the intermediate transfer belt 20 is pushed to the secondary transfer roller 30 side rather than the contact position at which contact begins (the positions in FIGS. 5D and 5E). The position is appropriately set so as to obtain a desired transfer pressure in a state where the contact pressure is high (a state where the contact pressure is high).

  In the case of the paper type A (thick paper), the press contact position may be a position where it is not pushed in compared to the case of the paper type B (thin paper). Even thick paper may not be pushed in depending on the paper type.

<Position control for approach and separation>
FIG. 6 is a timing chart showing the positional relationship between the surfaces of the two rotating bodies in the contact / separation operation when transporting the paper continuously, and FIG. 7 is a control flowchart in the transport device of the first embodiment.

  The control of the approaching / separating operation of the rotating body in the transport apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 6 and 7. In addition, since the counter roller 24 is a mechanism that moves the intermediate transfer belt 20 that is the first rotating body, the surface position of the intermediate transfer belt 20 may be expressed as the position of the counter roller 24 below. Moreover, the vertical axis | shaft of FIG. 6 is a distance between rotary bodies, and a distance is so small that a vertical axis | shaft goes up, and a distance becomes the smallest in a press-contact position.

  As a premise, in the conveyance device 80, the intermediate transfer belt 20 and the secondary transfer roller 30, which are two rotating bodies, are kept in a separated state during a period when the sheet is not conveyed.

  In step S201 in FIG. 7 (hereinafter simply referred to as “S”), the control unit 100 acquires a sheet conveyance instruction from the main control unit 91. For example, the paper conveyance instruction indicates that the printing instruction has arrived at the control unit 100.

  In step S <b> 202, the control unit 100 acquires sheet information and conveyance speed information from the main control unit 91.

  In S203, the control unit 100 determines the sheet information stored in the NVRAM 105, the preliminary approach speed V1 associated with the transport speed information, and the preliminary approach movement amount Y1 according to the paper information and transport speed information acquired in S202. Read and set the read value.

  In S204, according to the paper information acquired in S202, the conveyance speed information, and the preliminary approach speed V1 and the preliminary approach movement amount Y1 acquired in S203, the control unit 100 temporarily stops at the preliminary position that is the speed switching position. Ma and contact speed V2 are set.

  In this speed setting, the contact speed V2 is set so that “preliminary approach speed (first speed) V1> contact speed (second speed) V2”. Here, the preliminary approach speed V1 and the contact speed V2 are speeds that move by driving the contact / separation motor 61, which is a stepping motor, at a frequency lower than the maximum self-starting frequency fs, and consider acceleration and deceleration. Instead, it moves at a constant speed and starts and stops at a constant speed.

  In S205, the control unit 100 according to the paper information and transport speed information acquired in S202, the preliminary approach speed V1 and the preliminary approach movement amount Y1 set in S203, the temporary stop time Ma and the contact speed V2 at the speed switching position. Sets the pressure contact time La, the separation speed V3, and the separation start timing t7.

  In S206, the control unit 100 starts the sheet conveyance by driving the sheet conveyance roller 72 (see FIG. 1) according to the conveyance speed information. Further, the rotation of the intermediate transfer belt 20 is started by rotating the driving roller 21 according to the conveyance speed information.

  When the writing start signal is asserted (turned ON) in S207 (Yes), the counter roller 24 is set at the preliminary approach speed V1 by driving the contact / separation motor 61 in S208 with the detection as a trigger. At this timing, the movement in the approaching direction is started, and the step count of the contact / separation motor 61 is started.

  S207 in FIG. 7 corresponds to the timing t0 in FIG. 6, and S208 corresponds to the timing t1.

  When the step of the contact / separation motor 61 reaches a predetermined count value corresponding to the preliminary approach movement amount Y1 in S209, the moving speed of the opposing roller 24 by the contact / separation motor 61 is switched to the contact speed V2 in S210 (FIG. 6). Timing t2, t3). For example, the moving speed in the approaching direction of the facing roller 24 is slowed by lowering the operating speed of the stepping motor constituting the contact / separation motor 61 to slow the rotational speed.

  If the suspension time is set to be present in S204, the moving speed of the contact / separation motor 61 is switched to the contact speed V2 after the set suspension time has elapsed in S210. FIG. 6 shows an example in which a temporary stop time is provided. However, when the transport speed is fast (for example, when the transport speed is higher than a predetermined threshold or higher), the time during which the contact / separation operation can be performed is shortened. For example, the pause time may not be provided between t0 and t1, between t2 and t3, and the like.

  When the conveyance speed is high, the detection timing (S207) based on the writing start signal may be equal to the timing of starting movement in the approach direction (S208) (t0 = t1). Or / and when the predetermined count value of the step of the contact / separation motor 61 is reached, that is, immediately after the opposing roller 24 has moved to the preliminary position, which is an arbitrary position, at the first speed (S209), the speed is switched. It may be moved in the approaching direction at the second speed (t2 = t3).

  When the contact / separation motor 61 rotates to a predetermined position in order to move the facing roller 24 in the approaching direction, and the HP sensor 65 is asserted in S211, counting of the number of steps to the pressure contact position is started in S212. (FIG. 6, timing t4).

  When the step of the contact / separation motor 61 reaches a predetermined count corresponding to the distance from the detection position of the HP sensor 65 to the pressure contact position in S213, the contact / separation motor 61 is stopped and the approaching direction of the opposing roller 24 is determined in S214. And the measurement of the pressure contact time La is started (timing t6 in FIG. 6).

  As shown in FIG. 6, the counter roller 24 reaches the contact position before reaching the press contact position. The contact position is a position where the sheet P on the transfer roller 30 and the surface of the intermediate transfer belt 20 wound around the counter roller 24 come into contact with each other. Simultaneously with the timing when the leading edge of the paper P reaches the counter area, the counter roller 24 reaches the contact position, and contact with the paper P is started by the intermediate transfer belt 20 and the secondary transfer roller 30 in the counter area. (Timing t5).

  The contact pressure between the intermediate transfer belt 20 and the secondary transfer roller 30 gradually increases from the timing when the sheet P reaches the facing area, and the facing roller 24 reaches the pressure contact position (FIG. 6, timing t6). ). Transfer from the intermediate transfer belt 20 to the paper P is performed in a state where the opposing roller 24 is located at the pressure contact position. It should be noted that the time until the opposing roller 24 moves from the contact position to the pressure contact position is short, and the counter roller 24 moves to the pressure contact position within a time of transporting several mm from the leading edge of the paper P (timing t5 → t6).

  In S215, when the set pressure contact time La has elapsed, that is, when it is detected by the timer that the separation start timing t7 (see FIG. 6) has been reached, the contact / separation motor 61 is driven and the opposing roller 24 is separated in S216. The movement in the separation direction is started at the speed V3.

  Here, FIG. 6 shows an example of a thick sheet, and an example in which the facing roller 24 moves away from the contact position at the same time as the trailing edge of the sheet P leaves the facing area is shown (timing t8).

  When the contact / separation motor 61 rotates to a predetermined position to move the opposing roller 24 in the separation direction, and the HP sensor 65 is asserted in S217, the number of steps to the separation position is counted in S218 (FIG. 6). , Timing t9).

  When the step of the contact / separation motor 61 reaches a predetermined count corresponding to the distance from the detection position of the HP sensor 65 to the separation position in S219, the contact / separation motor 61 is stopped and the separation direction of the facing roller 24 is stopped in S220. Is stopped (time t10 in FIG. 6).

  When the movement of the facing roller 24 to the separation position is finished, the contact / separation flow is finished.

  When the paper P passes through the facing area continuously, such as when printing a plurality of sheets, the same contact / separation flow is repeated as shown in FIG.

  By executing such a contact / separation flow, in S208 to S209, the preliminary approaching movement is performed by the preliminary approaching speed V1 and the preliminary approaching movement amount Y1 before the paper P enters between the two rotating bodies. The distance between the two rotating bodies can be quickly brought close to the vicinity of the pressure contact position. In S210 to S213, the contact speed V2 at the time of approach when the distance between the two rotators is narrowed can be further reduced, which can contribute to the reduction of shock jitter during the conveyance of the paper P. .

  Note that the above flow shows the contact / separation flow of the rotating body during normal printing, but it returns from an error or power-on, or returns to the separation position using the HP sensor 65 at reset. . For example, even if the relative position of the opposing roller 24 becomes unknown, the reference position can be detected by the HP sensor 65 by moving from the current position in the approaching direction or the separating direction. When the position reaches the reference position, the position is moved in the separation direction, and a predetermined count value corresponding to a predetermined distance from the reference position to the separation position can be used to return to the separation position.

<Adjustment due to differences in paper thickness>
FIG. 8 is a timing chart showing the positions of the two rotating bodies in the contact / separation operation when transporting sheets having different thicknesses. 8A shows an approach / separation operation example when a paper type A having a thick paper is being conveyed, and FIG. 8B is an approach / separation operation when a paper type B having a thin paper is being conveyed. An example is shown. The vertical axis for FIG. 8 is similar to FIG. 6 is also the same as FIG. 6 in that it may be expressed by the position of the opposing roller 24 that urges the intermediate transfer belt 20 that is the first rotating body.

  In the following description, it is assumed that the paper thickness of the paper type A is Ta, the paper thickness of the paper type B is Tb, and A is thicker than B (Ta> Tb).

  The arrival timing (t2, t12) to the preliminary position, the movement start timing (t3, t13) at the contact speed V2 from the preliminary position, the preliminary approach movement amount (Y1, Y2), and the temporary stop time (Ma, Mb) are: It depends on the paper thickness. The movement start timing at the contact speed V2 is t13 earlier than t3. The preliminary approach movement amount has a relationship of Y1 <Y2. The arrival timing (t2, t12), the movement start timing (t3, t13) and the preliminary approach movement amount (Y1, Y2) to the preliminary position vary depending on the distance from the preliminary position to the pressure contact position.

  Generally, the slower the contact speed V2, the smaller the influence on other members, and the shock jitter is reduced. However, in order to improve the conveyance speed of the paper P, it is necessary to shorten the time taken for the approach. Therefore, the approach speed is made two steps and the preliminary approach speed V1 is increased, so that the contact speed V2 at the time of contact can be decreased, so that both the transport speed and the reduction of shock jitter can be achieved. It becomes.

  Here, as shown in FIG. 8, the timing of reaching the press contact position and the timing of starting separation from the press contact position differ depending on the thickness of the paper.

  As shown in FIG. 8A and FIG. 8B, the opposite roller 24 is turned on at the same time as the leading edge of the paper P reaches the opposite area and starts entering, regardless of whether it is thick paper or thin paper. The controller 100 controls the contact / separation mechanism 60 to reach the contact position (CA, CB) (t5).

  In the case of a thick sheet shown in FIG. 8A, the control unit 100 is arranged so that the leading roller 24 reaches the pressure contact position after the leading edge of the sheet P reaches the facing region and starts entering. Controls the contact / separation mechanism 60 (t6).

  Also, in the case of a thin sheet shown in FIG. 8B, control is performed so that the opposed roller 24 reaches the pressure contact position after the timing when the leading edge of the sheet P reaches the opposed area and starts to enter the opposed area. The unit 100 controls the contact / separation mechanism 60 (t16). When the paper P is extremely thin, the timing at which the paper P reaches the opposing area and the timing at which the opposing roller 24 reaches the pressure contact position may be substantially the same.

  In general, when the interval between the rotating bodies is narrow and the contact pressure is high at the press contact position, for example, the position of the opposing roller 24 is close to the secondary transfer roller 30 and the intermediate transfer belt 20 is pushed more strongly toward the secondary transfer roller 30. If this is the case, shock jitter is likely to occur due to the paper entering the facing area.

  Therefore, in the present invention, the surface position of the intermediate transfer belt 20 at the time of entering the facing area at the front end of the sheet is made farther than the press contact position, and the contact pressure is lowered. That is, simultaneously with the insertion of the sheet P into the facing area, the facing roller 24 is moved so as to start the contact of the intermediate transfer belt 20 with the sheet P and then moved to the pressure contact position. Shock jitter can be reduced.

  On the other hand, when the sheet P enters the facing area and the counter roller 24 is moved from the non-contact state to press the intermediate transfer belt 20 against the sheet P, shock jitter due to the impact of contact may occur.

  Therefore, in the present invention, since the sheet P starts to contact the intermediate transfer belt 20 with the contact pressure being low at the same time as the insertion into the opposite area of the sheet P, the sheet P is gradually pushed in at a low contact speed V2. It is possible to reduce the occurrence of shock jitter after entering the opposite area of the paper.

  As described above, in the present invention, the transition from the contact state to the pressure contact state is performed at a low speed, so that shock jitter caused by the transported material entering the opposing region in the transfer can be reduced.

In the case of separation, assuming that the separation speed V3 when the paper is thick (Ta) is the separation start timing t7, and the separation speed V4 when the paper is thin (Tb) is V4 and the separation start timing t17, the separation start timing is Ta When> Tb, set as follows.
The separation start timing t17 is earlier than t7.
The separation speed of the rotating body is V3> V4.

  Specifically, in the case of a thick sheet as shown in FIG. 8A, the control unit starts the movement of the facing roller 24 from the press contact position to the separated position slightly earlier than the timing at which the trailing edge of the sheet P is sent out from the facing area. 100 controls the contact / separation mechanism 60 (t7). Then, the trailing edge of the sheet P is separated from the facing region at a timing slightly earlier than the timing (t8 ′) at which the facing roller 24 separates the intermediate transfer belt 20 from the contact position (t8).

  On the other hand, in the case of the thin sheet shown in FIG. 8B, the counter roller 24 is earlier than the timing (t8) at which the rear end of the sheet P moves away from the facing region and earlier than the case of the thick sheet. Is set to start moving from the pressure contact position to the separation position (t17). Then, the rear end of the sheet P moves away from the facing area (t8) later than the timing (t18) at which the facing roller 24 starts moving the intermediate transfer belt 20 from the contact position to the separated position.

  Here, when the thickness of the paper is thin, the start of movement to the separation position is accelerated and the separation speed is set to a low speed. By slowing the separation speed of the rotating body during separation, sticking of the paper P to the secondary transfer roller 30 and the intermediate transfer belt 20 can be suppressed.

  Further, when the paper is thin, the separation speed is reduced and the separation start timing is advanced, so that the separation operation time can be shortened while suppressing sticking. For this reason, various contact / separation operation times up to the next sheet can be shortened, and the conveyance speed can be increased.

  In the case of the thick paper shown in FIG. 8A and the case of the thin paper shown in FIG. 8B, the opposing roller moves to the separation position (t10, t20), and the movement of the opposing roller 24 stops.

  In this embodiment, even when the paper thickness is different in this way, the start timing of each operation is counted from the timing when the writing start signal is asserted, and after moving to the preliminary approach position, the contact position and the pressure contact The movement to the position is started.

  In the graph of FIG. 8, the difference in timing depending on the thickness is emphasized, but the contact and separation timing from the pressure contact position such as the arrival timing to the pressure contact position and the separation start timing from the pressure contact position is the thickness. When changing in accordance with the above, it is assumed that the adjustment is made within a margin range where image formation of the paper P is not performed.

  Further, due to the above-described separation operation, the intermediate transfer belt 20 and the secondary transfer roller 30 are in a separated state and the two rotating bodies are not in contact with each other during a period in which the paper P is not passing through, so that wear is not easily generated.

  Here, in general, when the distance between the rotating bodies is narrow and the contact pressure is high at the pressure contact position, for example, the position of the opposing roller 24 is close to the secondary transfer roller 30 and the intermediate transfer belt 20 is directed toward the secondary transfer roller 30. When it is pushed in more strongly, shock jitter due to slipping out of the paper from the press contact position is likely to occur during separation.

  Therefore, in the present invention, when the transported material is removed from the opposing region in the transfer, the pressure contact state is released and the contact pressure is reduced immediately before the rear end of the transported material is removed from the opposing region. It is possible to reduce shock jitter caused by falling out of the facing area.

<Second Embodiment>
FIG. 9 is a schematic view illustrating the configuration of a transport apparatus 80A including the contact / separation mechanism 60A according to the second embodiment.

  In the first embodiment shown in FIG. 2, the surface position of the intermediate transfer belt 20 is moved with respect to the secondary transfer roller 30 by moving the counter roller 24, but this embodiment shown in FIG. In the embodiment, the secondary transfer roller 30A is configured to make contact with and separate from the opposing roller 24A. In this configuration, the secondary transfer roller 30A functions as a first rotating body, and the intermediate transfer belt 20A functions as a second rotating body.

  Even in such a configuration, when the approach / separation operation is performed, the secondary transfer roller 30A is moved by the contact / separation motor 61A, which is a movement driving unit, controlled by the control unit 100A. Etc. are the same as in FIGS. In this configuration, when the entire secondary transfer roller 30A moves, the surface position of the secondary transfer roller 30A also moves.

  In the above-described example, the image forming apparatus such as a copying machine, a facsimile apparatus, and a printer apparatus is formed based on image information composed of electronic information as a transport apparatus that performs position control in the contact / separation operation of the rotating body according to the present invention. The secondary transfer device that transfers the image to the recording medium has been described as an example, but other configurations may be used.

  For example, in the above-described example, the intermediate transfer method has been described for the approach and separation of the two rotating bodies. However, the image forming apparatus to which the present invention is applicable need not be limited to the intermediate transfer method. For example, even a direct transfer system can be applied as long as it is a mechanism in which a photosensitive member and a rotating member facing each other are in contact with each other.

<Third Embodiment>
FIG. 10 is a schematic view illustrating the internal configuration of a direct transfer image forming apparatus according to the third embodiment.

  In the image forming apparatus 200 shown in FIG. 10, around the photosensitive belt 210, a charging device 211, exposure devices 212M, 212Y, 212C, and 212K, developing devices 213M, 213Y, 213C, and 213K, a cleaning device 214, A neutralizing device 216 and a transfer roller 230 are provided. In the direct transfer image forming apparatus 200, the charging device 211, the exposure device 212, the developing device 213, and the like function as an image forming unit.

  In this configuration example, for each color, the exposure device 212 serving as a writing device writes a latent image using laser light on the charged photosensitive belt 210, and the developing device 213 uses toner to use the photosensitive belt. The latent image on the surface 210 is developed. A color image is formed on the photosensitive belt 210 by repeating writing and developing for the number of times of the color of the toner.

  Then, the color image on the photosensitive belt 210 is transferred to the paper P at a position where the photosensitive belt 210 and the transfer roller 230 are sandwiched.

  After the transfer, the surface of the photoreceptor belt 210 is neutralized by the neutralization device 216 and cleaned by the cleaning device 214.

  In this configuration, the photosensitive belt 210 is stretched over a plurality of rollers 221, 222, 223, 223, 223, 223, and 223, and is driven by a driving roller 221 that is rotated by a photosensitive belt driving motor 224 in the drawing. Rotate in the direction of the arrow.

  In the present embodiment illustrated in FIG. 10, the opposing roller 222 is configured to perform a contact / separation operation with respect to the transfer roller 230. In this configuration, the photosensitive belt 210 functions as a first rotating body, and the transfer roller 230 functions as a second rotating body. In the present embodiment, the position where the photosensitive belt 210 and the transfer roller 230 face each other in the transport path is referred to as a facing area.

  In such a configuration, when the approach / separation operation is executed, the opposing roller 222 that is controlled by the control unit 240 and is driven by the contact / separation motor 261 around the photosensitive belt 210 is a movement target.

  In the present embodiment, the writing start signal acquired by the control unit 240 is a signal instructing to start writing from the exposure device 212 to the photosensitive belt 210, and the first embodiment is the timing for writing to the photosensitive member 10. Although there is no time difference in the primary transfer timing from the photoconductor 10 to the intermediate transfer belt 20, other controls and timings are the same as those in FIGS.

  Although FIG. 10 shows an example in which the photosensitive belt 210 functions as the first rotating body and the transfer roller 230 functions as the second rotating body, the direct transfer system also uses the same as in the second embodiment. The transfer roller provided on the outside can be moved toward and away from the belt, the transfer roller can be a first rotating body, and the photosensitive belt can be a second rotating body.

  Further, the photoconductor for performing direct transfer is not limited to a belt shape but may be a drum shape. In this case, not the surface position of the first rotator but the first rotator itself moves to contact and separate from the transfer roller.

  In the above example, the electrophotographic image forming apparatus has been described as an example, but other configurations may be used. For example, even an inkjet apparatus can be applied as long as it is a mechanism that contacts and separates opposing rotating bodies.

<Fourth Embodiment>
FIG. 11 is a schematic view illustrating the internal configuration of an inkjet image forming apparatus. In the image forming apparatus 300 of FIG. 11, the head unit corresponds to an image forming unit.

  In this configuration, the head units 350 </ b> C, 350 </ b> M, 350 </ b> Y, and 350 </ b> K eject ink droplets to form an image on the outer peripheral surface of the transfer belt 320.

  The drying mechanism 370 dries the image formed on the transfer belt 320 to form a film.

  The filmed image on the transfer belt 320 is transferred to the paper P at the transfer portion where the transfer belt 320 faces the transfer roller 330.

  The cleaning roller 323 cleans the surface of the transfer belt 320 after transfer.

  In the image forming apparatus 300 shown in FIG. 11, head units 350C, 350M, 350Y, and 350K, a drying mechanism 370, a cleaning roller 323, and a transfer roller 330 are provided around the transfer belt 320.

  In this configuration, the transfer belt 320 is wound around a drive roller 321, a counter roller 322, four shape maintaining rollers 324, four support rollers 335, and the like, and is driven by a drive roller 321 that is rotated by a transfer belt drive motor 327. Rotate in the direction of the arrow in the figure.

  Four support rollers 325 provided to face the head units 350C, 350M, 350Y, and 350K maintain the tension state of the transfer belt 320 when ink droplets are ejected from the head units 350.

  In the present embodiment shown in FIG. 11, the opposing roller 322 is configured to perform a contact / separation operation with respect to the transfer roller 330. In this configuration, the transfer belt 320 supported by the counter roller 322 functions as the first rotating body, and the transfer roller 330 functions as the second rotating body. In the present embodiment, a position where the transfer belt 320 and the transfer roller 330 face each other in the conveyance path is referred to as a facing area.

  In the present embodiment, the ejection start signal acquired by the control unit 340 is a signal that instructs the head unit 350 to start ejection of ink droplets onto the transfer belt 320. Similar to the third embodiment, there is no time difference between the writing timing on the photoconductor 10 and the primary transfer timing from the photoconductor 10 to the intermediate transfer belt 20, but different from the first embodiment. The timing and the like are the same as those in FIGS.

  Although FIG. 11 shows an example in which the transfer belt 320 functions as the first rotating body and the transfer roller 330 functions as the second rotating body, the ink jet system is also provided outside as in the second embodiment. The transfer roller can be moved toward and away from the transfer belt, the transfer roller may be a first rotating body, and the transfer belt may be a second rotating body.

  In addition, the application of the above-described transport device is not limited to the transfer device, and speed fluctuations that occur in at least one of the rotating bodies due to an impact when the material to be transported enters the facing region between the first rotating body and the second rotating body. As long as it is effective to suppress the rotation, it can be applied to other devices. Other examples of the image forming apparatus include a fixing device and a penetrating material coating device, but are not limited thereto. Furthermore, any conveyance mechanism that contacts and separates the rotating body can be applied, not just an image forming apparatus. For example, a sheet inspection apparatus can be considered, but the present invention is not limited thereto.

  In the above example, the counter roller 24 is described as a roller, but the counter member may be a mechanism that urges a part of the intermediate transfer belt 20 that is the first rotating body, and does not need to be a roller. . For example, a shaft or the like that does not rotate may be used.

  In the first and third embodiments described above, the secondary transfer member or transfer member, which is the second rotating body, is a roller. However, if the second rotating body can contact and separate from the first rotating body. For example, a belt may be used.

  In the second and fourth embodiments described above, the secondary transfer member, which is the first rotating body, or the transfer member is a roller. However, the first rotating body can be brought into contact with and separated from the second rotating body. For example, the second rotating body may be a movable roller or a belt wound around a shaft.

  In the above example, each time is counted and controlled. However, all times may be counted from a reference timing such as assertion of a write start signal. Further, for example, the start of movement in the separation direction may be managed by counting from other sensors, such as managing by counting from the detection timing of the HP sensor 65.

  Furthermore, in the above example, at least the surface position of either the first rotating body or the second rotating body is moved, but even if at least the surface positions of both the first rotating body and the second rotating body are operated, good. Even when both of the rotating bodies are moved, it is preferable to operate so that the distance between the rotating bodies of the first rotating body and the second rotating body takes the distance shown in FIG. 6 or FIG.

  In the above example, one of the first rotating body and the second rotating body is a roller and the other is a belt, but both may be rollers. Further, both may be belts.

  Further, in the above example, at least the surface of either the first rotating body or the second rotating body moves in the vertical direction, but the moving direction is not limited to the vertical direction. For example, when the first rotator is a belt, even if at least the surface of the first rotator is brought into contact with the second rotator by rotating as a whole around a roller other than the portion in contact with the second rotator, good.

  In the above example, the conveyance speed is switched from the first speed to the second speed by a predetermined number of stepping motors, but the sensor detects the distance between the first rotating body and the second rotating body. May be switched from the first speed to the second speed when the threshold distance is reached. In this case, the threshold distance may be changed according to the thickness of the sheet-like material to be conveyed.

  Further, the sheet-like transported material transported by the transport device of the present invention is not limited to a recording medium such as paper. For example, “sheet-like transported material” is a material to which liquid such as ink or powder such as toner can be attached at least temporarily, and adheres and adheres, or adheres and penetrates. Means. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, media such as powder layers, organ models, and test cells. Unless otherwise, everything that liquids and powders adhere to is included.

  Further, the material of the “sheet-like material to be conveyed” is a predetermined material such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc., when the conveying device is not applied to the image forming apparatus. Any material may be used as long as it is not a liquid or powder that can be attached as long as it is a sheet-like material that is applied to a transport device that is an object to be approached and separated.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations shown here, such as combinations with other elements, etc., in the configurations described in the above embodiments. These points can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form.

10 (10K, 10C, 10M, 10Y) photoconductor (image forming unit)
20 Intermediate transfer belt (first rotating body, image carrier)
20A intermediate transfer belt (second rotary member, image carrier)
24 counter roller 30 secondary transfer roller (second rotating body)
30A secondary transfer roller (first rotating body)
31 Secondary transfer motor 32 Secondary transfer encoder 34 Memory (storage means)
35 Contact / separation mechanism (moving means)
52 Pressing force detection means 53 Speed correction means 60, 60A Contact / separation mechanism 61, 61A Contact / separation motor 65, 65P HP sensor (position detection sensor)
80, 80A Conveying device 90 Image forming device 100 Control unit (control board, control means)
200 Image forming apparatus 210 Photosensitive belt (first rotating body, image carrier)
211 Charging device (image forming unit)
212 Exposure device (image forming unit)
213 Developing device (image forming unit)
222 Counter roller 230 Transfer roller (second rotating body)
240 Control unit (control board, control means)
300 Image forming apparatus 320 Transfer belt (first rotating body, image carrier)
212 Counter roller 330 Transfer roller (second rotating body)
350 Head unit (image forming unit)
P paper (sheet-like material to be conveyed)
V1 Preliminary approach speed (first movement speed)
V2 contact speed (second movement speed)
V3 separation speed (for cardboard)
V4 separation speed (for thin paper)
Ma, Mb Temporary stop time La, Lb Pressure welding time Y1, Y2 Preliminary approaching movement amount (specific movement amount, arbitrary distance)
PA, PB Preliminary position (arbitrary position)
CA, CB contact position

JP 2006-061828 A

Claims (12)

A conveying device that conveys a sheet-like material to be conveyed between a first rotating body provided rotatably and a second rotating body provided rotatably and opposed to the first rotating body. ,
In a facing region where the first rotating body and the second rotating body face each other, a contact position where both the first rotating body and the second rotating body are in contact with the material to be conveyed, and the first rotating body A contact / separation mechanism capable of moving at least a surface position of at least one of the rotating bodies of the first rotating body and the second rotating body between the first rotating body and the second rotating body.
With
The contacting / separating mechanism is
When moving at least the surface position of the at least one rotating body from the separated position toward the contact position,
After moving from the separated position to an arbitrary position between the separated position and the contact position at a first speed, the contact is made from the arbitrary position at a second speed that is lower than the first speed. Move it to a position,
Conveying device. The contacting / separating mechanism is
Before the tip of the transported material reaches the facing area, at least the surface position of the at least one rotating body is moved to the arbitrary position at the first speed, and the facing area is moved to the facing area. In correspondence with the timing at which the tip of the material to be conveyed arrives, the contact position is reached at the second speed,
The transport apparatus according to claim 1. The contacting / separating mechanism is
At least the surface position of at least one of the rotating bodies is movable to a pressure-contacting position where the distance between at least the surface of the first rotating body and the second rotating body is closer than the contact position;
Causing at least the surface position of at least one of the rotating bodies to reach the pressure contact position at a timing later than the timing at which the tip of the material to be conveyed reaches the facing region,
The transport apparatus according to claim 1 or 2. The contacting / separating mechanism is
At least the surface position of at least one of the rotating bodies is movable to a pressure-contacting position where the distance between at least the surface of the first rotating body and the second rotating body is closer than the contact position;
The distance between the first rotating body and the second rotating body begins to increase from the pressure contact position earlier than the timing at which the rear end of the transported material is sent out from the facing area.
The conveyance apparatus as described in any one of Claims 1 thru | or 3. The contacting / separating mechanism is
At least the surface position of at least one of the rotating bodies is movable to a pressure-contacting position where the distance between at least the surface of the first rotating body and the second rotating body is closer than the contact position;
When the transported material is thin, the timing at which the distance between the first rotating body and the second rotating body starts to increase from the pressure contact position is made earlier than when the transported material is thick.
The conveyance apparatus as described in any one of Claims 1 thru | or 4. The contacting / separating mechanism is
At least the surface position of at least one of the rotating bodies is movable to a pressure-contacting position where the distance between at least the surface of the first rotating body and the second rotating body is closer than the contact position;

When the transported material is thin, the movement of at least the surface of any one of the rotating bodies from the pressure contact position to the separation position is performed at a lower speed than when the transported material is thick.
The conveyance apparatus as described in any one of Claims 1 thru | or 4. A control unit for controlling the contact / separation mechanism;
The control unit obtains information on the type of the sheet-like transported material,
In accordance with the thickness of the material to be conveyed, an arbitrary distance from the separated position to the arbitrary position is changed.
The conveyance apparatus as described in any one of Claims 1 thru | or 6. A control unit for controlling the contact / separation mechanism;
The control unit provides a pause time when shifting from the first speed to the second speed when the transport speed of the transported material is a low speed equal to or lower than a threshold value.
The conveyance apparatus as described in any one of Claims 1 thru | or 6. In the conveyance apparatus as described in any one of Claims 1 thru | or 8,
Either the first rotating body or the second rotating body is an image carrier,
Transferring an image carried on the first rotating body onto the transported material in an opposing region where the first rotating body and the second rotating body are opposed to each other;
Transfer device. An image forming unit for forming an image on the image carrier;
A transfer device according to claim 9.
Image forming apparatus. Position control in a conveying apparatus that conveys a sheet-like material to be conveyed between a first rotating body provided rotatably and a second rotating body provided rotatably and opposed to the first rotating body. A method,
In a facing region where the first rotating body and the second rotating body face each other, a contact position where the first rotating body and the second rotating body are in contact with the material to be conveyed, the first rotating body, and the It is possible to move at least the surface of the rotating body of at least one of the first rotating body and the second rotating body between the separated position where the second rotating body is separated,
When moving at least the surface of at least one of the rotating bodies from the separated position toward the contact position,
Moving from the separated position to an arbitrary position between the separated position and the contact position at a first speed;
Moving from the arbitrary position to the contact position at a second speed lower than the first speed,
Position control method. A computer is caused to execute the position control method according to claim 11.
Rotating body position control program.

Images