JP5880051B2 - Recording material conveyance direction switching device, image forming apparatus, and program - Google Patents

Description

  The present invention relates to a recording material conveyance direction switching device, an image forming apparatus, and a program.

  As a device for switching the sheet conveyance direction in the branch portion of the sheet conveyance path in an image forming apparatus such as an electrophotographic copying machine or a printer, a guide for switching the position by a solenoid or the like has been conventionally selected at the branch portion. 2. Description of the Related Art Gate-type sheet conveyance path switching devices that block a conveyance path entrance different from the conveyance path and feed a sheet to a selected path are widely used.

Patent Document 1 includes a current detection resistor, a differential circuit, and a calculation device as detection means for detecting the start and end of suction of the plunger. The calculation means predicts and detects the time from the start of suction of the plunger to the completion of suction. When the suction start of the plunger is detected by the means, the current supplied to the coil is controlled based on the predicted time. At that time, the arithmetic unit compares the measured time with the predicted time from the start of suction of the plunger to the completion of suction. In addition, a solenoid control device is disclosed that optimizes the current control after the next time or optimizes the prediction of the time from the start and the end of the plunger suction to the next time.
Patent Document 2 discloses that a solenoid driving device that drives by setting the driving voltage of the solenoid to V1, switches the driving voltage to V2 lower than V1 when the driving current reaches a predetermined value, and switches the driving voltage to V1 after a predetermined time. Is disclosed.

JP 2011-23588 A JP 2009-152492 A

  Here, it is preferable that the switching means for switching the conveyance direction of the recording material is less likely to change in operation even if the interval at which the recording material is conveyed changes.

According to the first aspect of the present invention, the conveyance direction of the recording material is switched by selectively moving the first position and the second position in the mechanism of the image forming apparatus that forms an image on the recording material. A switching means, and a moving means for moving the switching means between the first position and the second position by increasing or decreasing a force acting on the switching means at a predetermined time, When the interval at which the recording material is conveyed is smaller than a predetermined interval, the moving unit acts on the switching unit so as to cancel the force that the recording material acts on the switching unit according to the type of the recording material. The recording material transport direction switching device is characterized in that the impulse to be changed is changed.

According to a second aspect of the present invention, when the interval at which the recording material is conveyed is smaller than a predetermined interval, the moving unit has a force that the recording material acts on the switching unit depending on the thickness of the recording material. 2. The recording material transport direction switching device according to claim 1 , wherein the impulse applied to the switching means is changed so as to cancel out the recording material.
According to a third aspect of the present invention, when the interval at which the recording material is conveyed is smaller than a predetermined interval, the moving unit is configured such that the interval at which the recording material is conveyed is equal to or greater than the predetermined interval. 3. The recording material conveyance direction switching device according to claim 1, wherein the movement is started at a time earlier than the case.

According to a fourth aspect of the present invention, there is provided a toner image forming means for forming a toner image, a recording material conveying means for conveying a recording material, and a toner image formed by the toner image forming means is conveyed by the recording material conveying means. A transfer means for transferring to the recording material to be transferred, a fixing means for fixing the toner image transferred to the recording material by the transfer means, and a first position and a second position by selectively moving A switching unit that switches the conveyance direction of the recording material, and a movement that moves the switching unit between the first position and the second position by increasing or decreasing a force applied to the switching unit in a predetermined time. And a control means for controlling the moving means, wherein the control means, when the interval at which the recording material is conveyed is smaller than a predetermined interval, according to the type of the recording material But An image forming apparatus characterized by changing the impulse to be applied to the switching means so as to cancel the force acting on the serial switching means.

  A fifth aspect of the present invention is the image forming apparatus according to the fourth aspect, wherein the switching unit is provided on the recording material conveyance downstream side of the fixing unit.

According to the sixth aspect of the present invention, the recording material is conveyed in the conveying direction by selectively moving the first position and the second position in the computer by the mechanism of the image forming apparatus that forms an image on the recording material. A function for controlling the moving means for moving the switching means between the first position and the second position by increasing or decreasing the force applied to the switching means for switching between the first position and the second position, and the recording A function for calculating the interval at which the recording material is conveyed, and when the interval at which the recording material is conveyed is smaller than a predetermined interval , the force that the recording material acts on the switching means according to the type of the recording material And a function of changing an impulse applied to the switching means so as to cancel .

According to the first aspect of the present invention, there is provided a recording material conveyance direction switching device that is less likely to change in operation even when the interval at which the recording material is conveyed changes as compared with the case where this configuration is not adopted. Can do.
According to the second aspect of the present invention, as compared with the case where the present configuration is not adopted, even when the thickness of the recording material changes, the time for switching the switching means is less likely to change.
According to the invention of claim 3, the switching of the switching means can be finished before the next recording material is conveyed.
According to the fourth aspect of the present invention, it is possible to provide an image forming apparatus with higher silence as compared with the case where this configuration is not adopted.
According to the fifth aspect of the present invention, the quietness can be further enhanced even when images are formed on both sides of the recording material, as compared with the case where this configuration is not adopted.
According to the invention of claim 6, it is possible to realize control by a computer to make the sound generated when the switching means moves smaller than in the case where this configuration is not adopted.

1 is a diagram illustrating a configuration of an image forming apparatus to which the exemplary embodiment is applied. (A)-(d) is the figure explaining operation | movement of each mechanism in the case of performing double-sided printing on several sheets of paper. (E)-(g) is a figure explaining operation | movement of each mechanism in the case of performing double-sided printing on several sheets of paper. (A)-(b) is a figure explaining a switching part (switching apparatus). It is the perspective view explaining the switching part. (A)-(b) is the figure explaining the control method for operating a switching part. (C)-(d) is the figure explaining the control method for operating a switching part. It is a block diagram of the drive control part in this Embodiment. It is the flowchart explaining the control method of the gate member in this Embodiment. (A)-(c) is a graph explaining the control signal (drive signal) output from a current control part. (D)-(f) is a graph explaining the control signal (drive signal) output from a current control part. (A)-(c) is a graph explaining the other example of the control signal (drive signal) output from a current control part. (D)-(f) is a graph explaining the other example of the control signal (drive signal) output from a current control part.

<Description of Entire Image Forming Apparatus>
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a diagram illustrating a configuration of an image forming apparatus 1 to which the exemplary embodiment is applied. An image forming apparatus 1 shown in FIG. 1 is configured by a so-called tandem method using an electrophotographic method, and an image forming process unit 10 as an example of a toner image forming unit that forms a toner image, and the operation of the image forming apparatus 1 as a whole. And a control unit 50 for controlling. The image forming apparatus 1 also stores an image processing unit 51 that performs predetermined image processing on image data received from, for example, an image reading device 4 such as a personal computer (PC) 3 or a scanner, and a processing program. And an external storage unit 52 realized by, for example, a hard disk (Hard Disk Drive).

The image forming process unit 10 forms four toner images respectively forming yellow (Y), magenta (M), cyan (C), and black (K) toners arranged in parallel at predetermined intervals. Image forming units 11Y, 11M, 11C, and 11K (also collectively referred to as “image forming unit 11”) are provided.
The image forming unit 11 includes a photosensitive drum 12 on which an electrostatic latent image is formed while rotating in the direction of arrow A, a charging roll 13 that uniformly charges the surface of the photosensitive drum 12 with a predetermined potential, And a print head 14 that exposes the photosensitive drum 12 charged by the charging roll 13 based on the image data. Further, the image forming unit 11 includes a developing unit 15 that develops the electrostatic latent image formed on the photosensitive drum 12 and a drum cleaner 16 that cleans the surface of the photosensitive drum 12. Each of the four image forming units 11Y, 11M, 11C, and 11K is configured in substantially the same manner except for the toner stored in the developing unit 15, and each of the image forming units 11 is yellow (Y) and magenta (M). , Cyan (C) and black (K) toner images are formed.

  Further, the image forming process unit 10 intermediates the intermediate transfer belt 20 onto which the respective color toner images formed on the respective photosensitive drums 12 of the respective image forming units 11 are transferred, and the respective color toner images of the respective image forming units 11. Primary transfer rolls 21Y, 21M, 21C, and 21K (also collectively referred to as “primary transfer roll 21”) that sequentially transfer (primary transfer) to the transfer belt 20 are provided. Further, the image forming process unit 10 performs batch transfer (secondary transfer) of the superimposed toner image transferred onto the intermediate transfer belt 20 onto the sheet P as a recording material (recording paper) at the secondary transfer unit T. A secondary transfer roll 26 and a fixing device 30 for fixing the secondary transferred image on the paper P are provided. In the image forming apparatus 1 of the present embodiment, the intermediate transfer belt 20, the primary transfer roll 21, and the secondary transfer roll 26 constitute a transfer unit that transfers the toner image onto the paper P. The fixing device 30 functions as a fixing unit that fixes the toner image on the paper P.

The intermediate transfer belt 20 includes a drive roll 24 that rotationally drives the intermediate transfer belt 20, a backup roll 25 provided at a position opposite to the secondary transfer roll 26, a tension roll 27 that applies tension to the intermediate transfer belt 20, and a stretching roll. 28 and primary transfer rolls 21Y, 21M, 21C, 21K and the like, and circulates and moves in the direction of arrow B.
The fixing device 30 includes a fixing roll 31 having a heating source therein, and a pressure roll 32 arranged in pressure contact with the fixing roll 31. The fixing device 30 fixes the toner image on the paper P by passing the paper P holding the unfixed toner image between the fixing roll 31 and the pressure roll 32 and heating and pressing the paper P. To do.

In the image forming apparatus 1 according to the present embodiment, the image forming process unit 10 performs an image forming operation under the control of the control unit 50. In other words, when forming a color image, the print job data input from the PC 3 or the image reading device 4 is subjected to predetermined image processing by the image processing unit 51 and sent to the print head 14 for each color. It is done. For example, in the black (K) image forming unit 11 </ b> K, the surface of the photosensitive drum 12 that is uniformly charged by the charging roll 13 at a predetermined potential is transferred from the image processing unit 51 by the print head 14. Exposure is performed based on the color image data, and an electrostatic latent image is formed on the photosensitive drum 12. The formed electrostatic latent image is developed by the developing device 15, and a black (K) toner image is formed on the photosensitive drum 12. Similarly, in the image forming units 11Y, 11M, and 11C, yellow (Y), magenta (M), and cyan (C) toner images are formed.
When a monochrome image is formed, a black (K) toner image is formed only in the black (K) image forming unit 11K.

The image forming apparatus 1 according to the present embodiment includes transport paths R1, R2, R3, R4, and R5 as a paper transport system.
The transport path R <b> 1 is for transporting the paper P from the paper storage trays 40 </ b> A and 40 </ b> B to the secondary transfer unit T and the fixing device 30.
The transport path R2 is for discharging the paper P transported by the transport path R1 from the paper discharge unit Q.
The transport path R3 is for switching back the paper P in order to reverse the paper P transported by the transport path R1 during duplex printing.
The transport path R4 is used when performing duplex printing, and is used for transporting the paper P reversed in the transport path R3 to the transport path R1 again. That is, when the paper P is transported from the transport path R4 to the transport path R1, an image is formed on the back surface, which is the second surface of the paper P, by passing through the secondary transfer unit T and the fixing device 30.
The transport path R <b> 5 is for transporting the paper P from the manual paper storage tray 56 to the secondary transfer unit T.
Further, the image forming apparatus 1 according to the present embodiment includes a switching unit 60 that switches the sheet P transported on the transport path R1 to the other transport paths R2, R3, and R4, as will be described in detail later.

  Each color toner image formed by each image forming unit 11 is applied with a predetermined primary transfer bias voltage from a power supply device as a high-voltage primary transfer power source on an intermediate transfer belt 20 that circulates and moves in the direction of arrow B. The toner images are sequentially electrostatically transferred by the primary transfer rolls 21, and a superimposed toner image is formed on the intermediate transfer belt 20. As the intermediate transfer belt 20 moves, the superimposed toner image is conveyed toward the secondary transfer portion T where the secondary transfer roll 26 and the backup roll 25 are arranged.

On the other hand, in the image forming apparatus 1, a plurality of sheets P of different sizes or different paper types are stored in the sheet storage trays 40A and 40B, respectively. When the paper P stored in the paper storage tray 40A is designated by the control unit 50, the paper P is taken out from the paper storage tray 40A by the feed roll 41a, and the transport path R1 is moved by the transport rolls 42a and 42c. Each sheet is conveyed to the position of the registration roll 43. When the paper P stored in the paper storage tray 40B is designated by the control unit 50, the paper P is taken out from the paper storage tray 40B by the feed roll 41b, and is moved along the transport path R1 by the transport rolls 42a, 42b, and 42c. Each sheet is conveyed to the position of the registration roll 43. In this embodiment, the paper storage trays 40A and 40B are provided. However, it is also conceivable to provide a paper storage tray having a larger number.
Next, the paper P is fed out from the registration roll 43 in accordance with the timing when each color toner image on the intermediate transfer belt 20 is conveyed to the secondary transfer portion T. A voltage is applied to the secondary transfer portion T from a power supply device as a high-voltage secondary transfer power supply. As a result, the toner images of the respective colors are collectively electrostatically transferred (secondary transfer) onto the paper P by the action of the transfer electric field formed by the secondary transfer roll 26 and the backup roll 25.

Thereafter, the sheet P on which the superimposed toner image is electrostatically transferred is peeled off from the intermediate transfer belt 20 and conveyed to the fixing device 30. The unfixed toner image on the paper P conveyed to the fixing device 30 is fixed on the paper P by being subjected to fixing processing by heating and pressurization by the fixing device 30. Then, the sheet P on which the image is formed is transported from the transport path R1 to the transport path R2 by the switching unit 60 during single-sided printing, so that the post-fixing transport roll 44 and the discharge roll 45 are used to transport the paper discharge section of the image forming apparatus 1. Discharged from Q.
The toner (transfer residual toner) adhering to the intermediate transfer belt 20 after the secondary transfer is removed by a belt cleaner 23 disposed in contact with the intermediate transfer belt 20 to prepare for the next image forming cycle.

On the other hand, during double-sided printing, when the paper P on which image formation has been performed on the front surface, which is the first surface, is conveyed, the paper P from the conveyance path R1 is conveyed by the switching unit 60 to the conveyance path R3. The paper P transported to the transport path R3 once stops, then switches back and returns to the original direction. At this time, the switching unit 60 changes its posture within the time during which the paper is being transported to the transport path R2. The sheet P is transported to the transport path R4 by the action of the switching unit 60.
The paper P transported to the transport path R4 is transported by the double-sided transport rolls 48a, 48b, 48c and reaches the secondary transfer portion T. In the secondary transfer portion T, each color toner image held on the intermediate transfer belt 20 is transferred onto the first sheet P by the transfer electric field formed by the secondary transfer roll 26 and the backup roll 25 as in the case of the surface. Secondary transfer is performed collectively on the rear surface, which is the second surface.
The paper P having the toner images transferred on both sides in this manner is fixed by the fixing device 30 as in the case of the front side. Then, the sheet is transported from the transport path R1 to the transport path R2 by the switching unit 60 and discharged from the paper discharge unit Q of the image forming apparatus 1. When one sheet P is to be printed on both sides, image formation is performed as described above. However, when duplex printing is performed on a plurality of sheets P, image formation is performed according to the procedure described below. .

FIGS. 2-1 (a) to (d) and FIGS. 2-2 (e) to (g) are diagrams for explaining the operation of each mechanism when performing double-sided printing on a plurality of sheets of paper P. FIGS.
Here, a case where the paper P is taken out from the paper storage tray 40A will be described.
First, the first sheet P1 is taken out from the sheet storage tray 40A using the feed roll 41a and sent out to the transport path R1 (FIG. 2-1 (a)).

  The paper P1 is fed toward the upper portion in the drawing on the transport path R1 by the transport rolls 42a and 42c and the registration roll 43. Then, the toner image is secondarily transferred by the secondary transfer portion T and fixed by the fixing device 30 to form an image on the surface of the paper P1 (FIG. 2-1 (b)).

  Next, the switching unit 60 is switched, and the paper P1 is transported to the transport path R3 by the action of the switching unit 60. Then, the paper P <b> 1 is transported to the reverse position where the paper P <b> 1 is switched back by the transport roll 44, the reverse roll 46 and the discharge roll 47. When the paper P1 reaches the reversal position, the reversing roll 46 and the discharge roll 47 are temporarily stopped, so that the paper P1 is also temporarily stopped. Next, when the switching unit 60 is switched again so as to transport the paper P1 to the transport path R4, the reversing roll 46 and the discharge roll 47 rotate in the opposite directions, and the paper P1 is moved in the direction of the transport path R4. It pays out (FIG. 2-1 (c)). Thereby, a reversing operation for reversing the paper P1 is performed. At this time, the second sheet P2 is sent out to the transport path R1.

  While the paper P1 is transported by the double-sided transport rollers 48a, 48b, and 48c and moves downward along the transport path R4 in the drawing, an image is formed on the surface of the paper P2 in the same manner as the paper P1. At this time, the reverse roll 46 and the discharge roll 47 are stopped, and the switching unit 60 is switched again so as to transport the paper P2 from the transport path R1 to the transport path R3 (FIG. 2-1 (d)). ).

  The paper P2 is transported from the transport path R1 to the transport path R3 by the action of the switching unit 60, and the reversing operation is performed in the same manner as the paper P1. The paper P2 on which the reversal operation has been performed is transported to the transport path R4 by the switching unit 60. Further, the paper P1 enters the transport path R1 again from the transport path R4, and image formation is performed on the back surface of the paper P1. At the same timing when the paper P2 is sent out from the transport path R3 to the transport path R4, the paper P1 is transported from the transport path R1 to the transport path R2 by the switching unit 60 and discharged from the paper discharge section Q by the discharge roll 45. . Further, at this time, the third sheet P3 is sent out to the transport path R1 (FIG. 2-2 (e)).

  While the paper P2 is transported by the double-sided transport rolls 48a, 48b, and 48c and moves on the transport path R4, an image is formed on the surface of the paper P3. At this time, the switching unit 60 is switched again so as to transport the paper P3 from the transport path R1 to the transport path R3 (FIG. 2-2 (f)).

The sheet P3 is transported from the transport path R1 to the transport path R3 by the action of the switching unit 60, and the reversing operation is performed. The paper P3 subjected to the reversing operation is transported to the transport path R4 by the switching unit 60. The paper P2 enters the transport path R1 again from the transport path R4, and image formation is performed on the back surface of the paper P2. At the same time as the paper P3 is sent out from the transport path R3 to the transport path R4, the paper P2 is transported from the transport path R1 to the transport path R2 by the switching unit 60 and discharged from the paper discharge section Q by the discharge roll 45. Further, at this time, the fourth sheet P4 is sent out to the transport path R1 (FIG. 2-2 (g)).
Thereafter, the operations of FIGS. 2-2 (f) to 2-2 (g) are repeated.

  As described above, image formation in the image forming apparatus 1 is repeatedly executed for the designated number of sheets. In this embodiment, feed rolls 41a and 41b, transport rolls 42a, 42b and 42c, registration roll 43, transport roll 44, discharge roll 45, reverse roll 46, discharge roll 47, double-sided transport rolls 48a, 48b and 48c. Can be grasped as an example of a sheet conveying means for conveying a recording material.

<Description of switching unit>
FIGS. 3A and 3B are diagrams illustrating a switching unit (recording material conveyance direction switching device) 60. FIG. 4 is a perspective view illustrating the switching unit 60.
Hereinafter, the configuration and operation of the switching unit 60 will be described with reference to FIGS. 3 (a) to 3 (b) and FIG. 4.
As shown in FIGS. 3A and 3B, the switching unit 60 is disposed so as to be rotatable around the rotation axis K, and is a first mechanism in the image forming apparatus 1 that forms an image on the paper P. The gate member 61 as an example of a switching unit that switches the transport direction of the paper P by selectively moving between the first position and the second position, and the force acting on the gate member 61 is increased or decreased during a predetermined time. Thus, the gate member 61 is rotated about the rotation axis K to change the posture of the gate member 61, and the solenoid as an example of a moving unit that moves the gate member 61 between the first position and the second position. 62, a spring member 63 as an example of an elastic body that is connected to the gate member 61 and, for example, the casing of the image forming apparatus and moves between the first position and the second position by cooperating with the solenoid 62. And solenoid And a current control unit 64 supplies the 2 to the current (driving current).

  The switching unit 60 includes a paper detection sensor 65 disposed on the downstream side of the fixing device 30 in the transport path R1, and a drive control unit 67 that receives the detection result of the paper detection sensor 65 and controls the driving of the solenoid 62. It is equipped with. In the present embodiment, the current control unit 64 and the drive control unit 67 can be regarded as control means for controlling the switching unit 60. Moreover, although the current control part 64 and the drive control part 67 may be installed in the switching part 60, you may comprise so that it may be included in a part of control part 50 shown in FIG.

  As shown in FIG. 4, the gate member 61 has a configuration in which a plurality of plate-like members 61 a having a substantially triangular shape are arranged in a row along the rotation axis K in a comb shape. Then, the paper P is guided by contacting the paper P at the side of the triangle, and the conveyance direction of the paper P is defined.

  The solenoid 62 includes a coil 62a having a space inside and a plunger (movable iron core) 62b disposed in the space of the coil 62a.

  The solenoid 62 of the present embodiment is a so-called pull solenoid. Therefore, when a predetermined current is supplied from the current control unit 64 to the coil 62a, the plunger 62b is attracted by the generated magnetic field. As a result, as shown in FIG. 3B, the plunger 62b is attracted from the outside of the solenoid to the inside, and moves in a direction (C2 direction) in which the amount of protrusion from the solenoid body is reduced. Here, as shown in FIG. 4, the pressing member 62 c connected to the plunger 62 b is in contact with a predetermined location 61 b of the gate member 61. Therefore, when the plunger 62b is sucked, the gate member 61 rotates (rotates in the direction D2) around the rotation axis K due to the pressing force generated through the pressing member 62c, and the position (first position) shown in FIG. 2 position).

  On the other hand, when no current flows through the coil 62a, the force generated by the magnetic field is not generated in the plunger 62b. At this time, the gate member 61 rotates around the rotation axis K (rotates in the D1 direction) by the tensile force of the spring member 63, and assumes the position (first position) shown in FIG. In both cases, a force in a direction protruding from the solenoid body acts on the plunger 62b by the pulling force of the spring member 63 acting indirectly through the gate member 61. Therefore, as shown in FIG. 3A, the plunger 62b protrudes from the solenoid body and moves in a direction (C1 direction) in which the protrusion amount from the solenoid body increases.

  That is, the gate member 61 is shown in the position (first position) shown in FIG. 3A and the position shown in FIG. 3B depending on whether the predetermined current is supplied to the coil 62a of the solenoid 62 or not. Go back and forth between the position (second position). Similarly, the plunger 62b goes back and forth between the position retracted into the solenoid body and the position protruding from the case where the predetermined current is not supplied to the coil 62a and the case where it is supplied.

  In addition, when a current is supplied to the coil 62a, the plunger 62b receives a force so as to move in a direction (C2 direction) in which the amount of protrusion from the solenoid body decreases, and the current supply to the coil 62a is reduced. When stopped, the tensile force of the spring member 63 receives the force in the opposite direction, that is, the force that moves in the direction in which the amount of protrusion from the solenoid body increases (direction C1). .

  The drive control unit 67 transmits an ON (ON) signal and an OFF (OFF) signal of the solenoid 62 to the current control unit 64 using information from the paper detection sensor 65 and the like. Then, the current control unit 64 supplies and interrupts the current to the coil 62a according to the ON signal and the OFF signal. That is, the current control unit 64 continues to supply current to the coil 62a while receiving the ON signal from the drive control unit 67, and while receiving the OFF signal from the drive control unit 67, No current is supplied to the coil 62a.

  In the switching unit 60 configured as shown in FIGS. 3 and 4, when the drive control unit 67 outputs an OFF signal, the current control unit 64 does not supply current to the solenoid 62. , The posture (first position) shown in FIG. Further, when the drive control unit 67 outputs an ON signal, the current control unit 64 supplies a predetermined current to the solenoid 62, whereby the gate member 61 is moved to the posture shown in FIG. Position). The gate member 61 and the solenoid 62 are selectively switched as shown in FIG. 3A or FIG.

In the case shown in FIG. 3A, the gate member 61 transports the paper P from the transport path R1 to the transport path R2. Further, at this position, the gate member 61 can transport the paper P which has been reversed after being transported to the transport path R3 to the transport path R4.
On the other hand, in the case shown in FIG. 3B, the gate member 61 transports the paper P from the transport path R1 to the transport path R3.

  More specifically, the gate member 61 is normally in the first position as shown in FIG. The gate member 61 at the first position closes the transport path R3, thereby transporting the paper P from the transport path R1 to the transport path R2. Further, this posture of the gate member 61 is a posture in which the transport path R1 is closed when viewed from the transport path R3, whereby the paper P from the transport path R3 is transported to the transport path R4. Therefore, the first position of the gate member 61 can be regarded as the initial position.

  In addition, when the current is supplied to the solenoid 62, the posture of the gate member 61 changes, and when it reaches the second position as shown in FIG. 3B, the gate member 61 at the second position is now Takes a posture of closing the conveyance path R2. Thereby, the paper P from the transport path R1 can be transported to the transport path R3. Therefore, the second position of the gate member 61 can be regarded as a driving position.

<Description of control of operation of switching unit>
FIGS. 5-1 (a) to (b) and FIGS. 5-2 (c) to (d) are diagrams illustrating a control method for operating the switching unit 60. FIG.
Among these, FIG. 5A is a graph illustrating a control signal (drive signal) output from the current control unit 64 when the gate member 61 is moved from the first position to the second position. Here, the vertical axis represents the drive current amount, and the horizontal axis represents time (t). FIG. 5B is a diagram illustrating the behavior of the gate member 61 at this time.
When the drive control unit 67 determines that the posture of the gate member 61 needs to be switched, the drive control unit 67 outputs an ON signal to the current control unit 64 as shown in FIG. At that time, the drive control unit 67 controls to output the ON signal at time t1 after outputting the ON signal at time t1, and then output the ON signal again at time t3. Accordingly, the current control unit 64 outputs a drive signal of the drive current amount D0 after time t1 to t2 and after time t3 as shown in the figure.

  With such control, as shown in FIG. 5B, the gate member 61 causes the current controller 64 to drive the drive current amount D0 when the drive controller 67 starts outputting the ON signal at time t1. When the signal is supplied to the solenoid 62, a force rotating in the direction of the arrow D2 is received by the suction operation of the solenoid 62, and the rotation starts in the direction of the arrow D2. Then, the drive control unit 67 continues to output the ON signal until time t2. Thus, in the present embodiment, the force applied to the gate member 61 can be changed by changing the amount of drive current supplied to the solenoid 62.

  Then, when the time t2 has elapsed, the drive control unit 67 continues to output the OFF signal until the time t3. Then, the current control unit 64 stops supplying the current to the solenoid 62, and the gate member 61 rotating in the direction of the arrow C2 by the action of the spring member 63 from time t2 to time t3 Receives force in the opposite direction. That is, the gate member 61 receives a braking force acting in the direction of the arrow D1 and rotates in the direction of the arrow D2 while reducing the rotation speed, thereby forming the state of the gate member 61 immediately before the collision.

  When the time t3 has elapsed, the drive control unit 67 continues to output the ON signal again, and in response to this, the current control unit 64 continues to supply the drive signal of the drive current amount D0. As a result, the gate member 61 rotating in the direction of the arrow D2 hits the stopper 612 and stops at the second position. Then, after stopping, the gate member 61 continues to receive the force in the direction of the arrow D2 by the suction operation of the solenoid 62, and thus maintains its posture without rotating in the direction of the arrow D1.

FIG. 5C is a graph for explaining a control signal output from the current control unit 64 when the gate member 61 is moved from the second position to the first position. Here, the vertical axis represents the drive current amount, and the horizontal axis represents time (t). FIG. 5D is a diagram illustrating the behavior of the gate member 61 at this time.
When the drive control unit 67 determines that the posture of the gate member 61 needs to be switched, the drive control unit 67 outputs an OFF signal to the current control unit 64 as shown in FIG. At that time, the drive control unit 67 controls to output an OFF signal at time t4, then output an ON signal at time t5, and then output an OFF signal again at time t6. Accordingly, the current control unit 64 outputs a drive signal of the drive current amount D0 before time t4 and at times t5 to t6 as illustrated.

  By such control, as shown in FIG. 5D, the gate member 61 causes the current control unit 64 to send the drive current to the solenoid 62 when the drive control unit 67 starts outputting the OFF signal at time t4. When the supply is stopped, the force of rotating in the direction of the arrow D1 is received by the tensile force of the spring member 63, and the rotation starts in the direction of the arrow D1. And the drive control part 67 continues outputting an OFF signal until time t5.

  Then, when the time t5 has elapsed, the drive control unit 67 continues to output the ON signal until the time t6. Then, the current control unit 64 supplies current to the solenoid 62, and the gate member 61 rotating in the direction of the arrow D1 by the suction operation of the solenoid 62 during the time t5 to the time t6 is reverse to the conventional one. Receive the force of the direction. That is, the gate member 61 receives a braking force acting in the direction of the arrow D2 and rotates in the direction of the arrow D1 while reducing the rotation speed, thereby forming the state of the gate member 61 immediately before the collision.

  When the time t6 has elapsed, the drive control unit 67 continues to output the OFF signal again, and the current control unit 64 stops supplying the drive current accordingly. Accordingly, the gate member 61 rotating in the direction of the arrow D1 hits the stopper 611 and stops at the first position. Then, after stopping, the gate member 61 continues to receive the force in the direction of the arrow D1 due to the tensile force of the spring member 63, and thus maintains its posture without rotating in the direction of the arrow D2.

  Thus, when the gate member 61 moves from the first position to the second position and when moving from the second position to the first position, the gate member 61 in the middle of the movement has a rotational speed. Receives braking force to decelerate. Therefore, the collision sound between the gate member 61 and the stoppers 611 and 612 at the time of switching is reduced. When the gate member 61 does not apply a braking force that decelerates the rotation speed, the moving speed becomes the fastest when the gate member 61 hits the stoppers 611 and 612. Therefore, a loud collision sound is generated.

Here, in order to improve the productivity of image formation, the interval of the conveyed paper P may be narrowed. At this time, the gate member 61 may start to move with the trailing edge of the paper P remaining on the gate member 61.
In other words, different transport paths may be used for the preceding paper P and the next paper P to be transported. Further, during the above-described double-side printing, the gate member 61 is frequently switched as described with reference to FIGS. At this time, since the interval between the sheets P is clogged, if the movement of the gate member 61 is started after the trailing edge of the preceding sheet P has passed through the gate member 61, the next sheet will be transferred before the movement of the gate member 61 is completed. The tip of P reaches the gate member 61. Therefore, in this case, it is necessary to start the movement of the gate member 61 with the trailing edge of the preceding paper P remaining on the gate member 61.

  However, depending on the paper type of the preceding paper P, the so-called stiffness of the paper P may act as a force on the gate member 61 when the gate member 61 moves. Therefore, the moving speed of the gate member 61 may change due to this. This means that the time of hitting the stoppers 611 and 612 changes when the gate member 61 moves. In this case, if the control shown in FIGS. 5-1 (a) and 5-2 (c) is performed as it is, the collision noise between the gate member 61 and the stoppers 611 and 612 at the time of switching may not be reduced. is there.

  Therefore, in the present embodiment, when the interval at which the paper P is conveyed is smaller than a predetermined interval, the above problem can be suppressed by changing the impulse applied to the gate member 61 according to the type of the paper P. Plan. In other words, this is also referred to as changing at least one of the force and time applied to the gate member 61 in accordance with the type of the paper P when the paper P is conveyed at an interval smaller than a predetermined interval. Furthermore, when the interval at which the sheet P is conveyed is smaller than a predetermined interval, it can be said that the integrated value of the force applied to the gate member 61 is changed according to the type of the sheet P.

FIG. 6 is a block diagram of the drive control unit 67 in the present embodiment.
As illustrated in FIG. 6, the drive control unit 67 includes a detection signal acquisition unit 671 that receives a detection signal from the paper detection sensor 65, a print job information acquisition unit 672 that acquires print job information, and a detection signal acquisition unit 671. A determination unit 673 that changes the control pattern based on the acquired detection signal and the print job information acquired by the print job information acquisition unit 672, and a storage unit that stores data that is a basis for the determination of the determination unit 673 674 and an output unit 675 that transmits a control signal to the current control unit 64 according to the control pattern determined according to the determination result of the determination unit 673.

  The determination unit 673 reads data and software stored in the storage unit 674 in advance and performs a predetermined process, and may be configured by a CPU, for example. Further, the storage unit 674 may be configured by a memory, for example.

FIG. 7 is a flowchart illustrating a method for controlling the gate member 61 in the present embodiment.
Hereinafter, an outline of the operation of the drive control unit 67 will be described with reference to FIGS. 6 and 7.
First, the paper detection sensor 65 detects the paper P, and transmits the detection signal to the detection signal acquisition unit 671 of the drive control unit 67 (step 101).
Upon receiving the detection signal from the paper detection sensor, the drive control unit 67 acquires the contents of the print job by the print job information acquisition unit 672 (step 102). Specifically, the print job information includes the size and thickness of the paper P, the presence / absence of double-sided printing, the presence / absence of paper reversal, the type of post-processing such as binding after image formation.

  Based on these pieces of information, the determination unit 673 determines whether or not it is necessary to switch the gate member 61 (step 103). When it is necessary to switch the gate member 61 (Yes in Step 103), the interval of the paper P is calculated based on the print job information (Step 104). Here, the interval of the paper P can also be calculated by the time interval of the detection signal from the paper detection sensor 65. If it is not necessary to switch the gate member 61 (No in Step 103), the process returns to Step 101.

  Then, the determination unit 673 determines whether or not the interval of the paper P is smaller than a predetermined value (step 105). If the interval between the sheets P is smaller than a predetermined value (Yes in step 105), is the sheet P a thin sheet having a predetermined thickness or a thick sheet exceeding a predetermined thickness? Is determined (step 106). Then, referring to the storage unit 674, a control pattern is determined according to the thickness of the paper P (step 107), and a control signal based on the determined control pattern is output from the output unit 675 (step 108).

  If the interval between the sheets P is equal to or greater than a predetermined value (No in step 105), the next sheet P is detected even if the switching of the gate member is started after the rear end of the sheet P passes through the gate member 61. Before the gate member 61 is reached. Therefore, the output unit 675 outputs a control signal based on a normal control pattern that waits for the trailing edge of the paper P to pass through the gate member 61 and starts switching the gate member 61 (step 109).

  FIGS. 8-1 (a) to (c) and FIGS. 8-2 (d) to (f) are graphs illustrating a control signal (drive signal) output from the current control unit 64. FIGS.

  Among these, FIGS. 8-1 (a)-(c) demonstrates the control signal (drive signal) output from the electric current control part 64 at the time of moving the gate member 61 from a 1st position to a 2nd position. It is a graph. The vertical axis represents the drive current amount, and the horizontal axis represents time (t). Here, FIG. 8A is a normal control pattern selected when the interval of the paper P is equal to or larger than a predetermined interval (in the case of No in step 105 in FIG. 7). It is the same as 1 (a). FIG. 8B is a control pattern when the interval between the sheets P is smaller than a predetermined interval and the sheet P is a thin sheet. Further, FIG. 8-1 (c) is a control pattern in the case where the interval of the paper P is smaller than a predetermined interval and the paper P is a thick paper.

  When the drive control unit 67 determines that the posture of the gate member 61 needs to be switched, the drive control unit 67 outputs the drive current D0 at time t1 (t1 ′, t1 ″) and then turns off at time t2 (t2 ′, t2 ″). Control is performed so that the ON signal is output again at time t3 (t3 ′, t3 ″) after the signal is output. In response to this, the current controller 64 drives the drive current after the time t1 (t1 ′, t1 ″) to t2 (t2 ′, t2 ″) and after the time t3 (t3 ′, t3 ″) as shown in the figure. A drive signal of the amount D0 is output.

When comparing FIGS. 8-1 (a) to (c), FIGS. 8-1 (b) and (c) delay the time for outputting the first drive current D0 from FIG. 8-1 (a). (Time t1 ′, t1 ″> time t1). When the interval at which the sheet P is conveyed is smaller than a predetermined interval, the gate member 61 moves from the first position to the second position by the reaction force of the sheet P remaining on the gate member 61. The force of the direction which helps is working. Therefore, such control is performed, the impulse generated by the solenoid 62 is reduced by the reaction force of the paper P, and the gate member 61 is compared with the case where the paper P is conveyed at a longer interval than a predetermined interval. Keep the behavior unchanged.
Further, when the time for stopping the output of the drive current amount D0 is compared, the time is shown in FIG. 8-1 (b) from FIG. 8-1 (b) and from FIG. 8-1 (b) to FIG. 8-1 (c). ((Time t3−time t2) <(time t3′−time t2 ′) <(time t3 ″ −time t2 ″)). That is, the time for temporarily stopping the suction of the solenoid 62 immediately before the gate member 61 collides with the stopper 612 and reducing the speed of the gate member 61 by the action of the spring member 63 becomes longer as the thickness of the paper P increases. Yes. That is, as the thickness of the paper P increases, the speed of the gate member is less likely to decrease due to the reaction force of the paper P, so that the operation of the gate member 61 is not changed by performing such control.

  On the other hand, FIGS. 8-2D to 8F illustrate control signals (drive signals) output from the current control unit 64 when the gate member 61 is moved from the second position to the first position. It is a graph. Here, the vertical axis represents the drive current amount, and the horizontal axis represents time (t). Here, FIG. 8-2 (d) is a normal control pattern selected when the interval of the paper P is equal to or larger than a predetermined interval (in the case of No in step 105 in FIG. 7). It is the same as 2 (c). FIG. 8-2 (e) shows a control pattern when the interval between the sheets P is smaller than a predetermined interval and the sheet P is a thin sheet. Further, FIG. 8-2 (f) is a control pattern in the case where the interval of the paper P is smaller than a predetermined interval and the paper P is a thick paper.

  When the drive control unit 67 determines that the posture of the gate member 61 needs to be switched, the drive control unit 67 outputs the drive current D0 at time t4 (t4 ′, t4 ″) and then turns off at time t5 (t5 ′, t5 ″). Control is performed so that the ON signal is output again at time t6 (t6 ′, t6 ″) after the signal is output. In response to this, the current controller 64 drives the drive current after time t4 (t4 ′, t4 ″) to t5 (t5 ′, t5 ″) and time t6 (t6 ′, t6 ″) as shown in the figure. A drive signal of the amount D0 is output.

When comparing FIGS. 8-2 (d) to (f), FIGS. 8-1 (e) and (f) stop outputting the first drive current D0 from FIG. 8-2 (d). The time for the action of the spring member to act on the gate member is shortened (time t4 ′, t4 ″ <time t4). When the interval at which the sheet P is conveyed is smaller than a predetermined interval, the gate member 61 moves from the second position to the first position by the reaction force of the sheet P remaining on the gate member 61. The force in the direction that prevents it works. Therefore, such control is performed, the impulse generated by the spring member 63 is increased by the reaction force of the sheet P, and the gate member 61 is compared with the case where the interval at which the sheet P is conveyed is longer than a predetermined interval. Keep the behavior of.
When the time for re-outputting the initial drive current amount D0 is compared, the time is shown in FIG. 8-2 (e) from FIG. 8-2 (d) and FIG. 8-2 (f) from FIG. 8-2 (e). ) Is shorter ((time t6−time t5)> (time t6′−time t5 ′)> (time t6 ″ −time t5 ″)). That is, immediately before the gate member 61 collides with the stopper 612, the suction of the solenoid 62 is temporarily resumed, and the time during which the speed of the gate member 61 is decreased is shortened as the thickness of the sheet P increases. Since the speed of the gate member 61 is likely to decrease due to the reaction force of the paper P as the thickness of the paper P increases, the operation of the gate member 61 is not changed by such control.

  As described above, in the present embodiment, the impulse applied to the gate member 61 is changed depending on the interval and thickness at which the paper P is conveyed. Therefore, the gate member 61 can be switched in response to the reaction force from the paper P that changes according to the presence or absence of the paper P at the location of the gate member 61 and the thickness of the paper P when the paper P remains. As a result, even if the interval at which the paper P is transported or the thickness of the paper P changes, the operation of the gate member 61 hardly changes, and the collision noise between the gate member 61 and the stopper 612 during switching is reduced. The phenomenon of disappearing can be suppressed.

  FIGS. 9-1 (a) to (c) and FIGS. 9-2 (d) to (f) are graphs for explaining other examples of control signals (drive signals) output from the current control unit 64. FIGS. .

  Among these, FIGS. 9-1 (a)-(c) demonstrates the control signal (drive signal) output from the electric current control part 64 at the time of moving the gate member 61 from a 1st position to a 2nd position. It is a graph. The vertical axis represents the drive current amount, and the horizontal axis represents time (t). Here, FIG. 9A is a normal control pattern that is selected when the interval between the sheets P is equal to or greater than a predetermined interval (No in step 105 in FIG. 7). It is the same as 1 (a). FIG. 9B is a control pattern when the interval between the sheets P is smaller than a predetermined interval and the sheet P is a thin sheet. Further, FIG. 9-1 (c) is a control pattern in the case where the interval of the paper P is smaller than a predetermined interval and the paper P is a thick paper.

  When comparing FIGS. 9-1 (a) to (c), FIG. 9-1 (b) from FIG. 9-1 (a) and FIG. 9-1 (c) from FIG. The drive current amount is lowered (D0> D1> D2). Here, the time for outputting the first drive current amounts D0, D1, and D2 is the same ((time t2−time t1) = (time t2′−time t1 ′) = (time t2 ″ −time t1 ″). )), Since the amount of drive current is reduced, a smaller impulse is applied to the gate member 61. By performing such control, the impulse generated by the solenoid 62 is made smaller by the reaction force of the paper P, and the gate member 61 is compared with the case where the interval at which the paper P is conveyed is longer than a predetermined interval. Keep the behavior of. As a result, the phenomenon that the collision noise between the gate member 61 and the stopper 611 at the time of switching is not reduced can be suppressed similarly to the description of FIGS.

  FIGS. 9-2D to 9F are graphs for explaining a control signal (drive signal) output from the current control unit 64 when the gate member 61 is moved from the second position to the first position. It is. The vertical axis represents the drive current amount, and the horizontal axis represents time (t). Here, FIG. 9D is a normal control pattern that is selected when the interval between the sheets P is equal to or greater than a predetermined interval (No in step 105 in FIG. 7). It is the same as 1 (a). FIG. 9-2 (e) shows a control pattern when the interval between the sheets P is smaller than a predetermined interval and the sheet P is a thin sheet. Further, FIG. 9-1 (f) is a control pattern in the case where the interval of the paper P is smaller than a predetermined interval and the paper P is a thick paper.

  In this control pattern, the drive current amount is increased in FIG. 9-2 (e) from FIG. 9-2 (d) and in FIG. 9-2 (f) from FIG. 9-2 (e) (D0 < D1 <D2). For this reason, a larger impulse can be applied to the gate member 61. By performing such control, the impulse generated by the solenoid 62 is increased by the reaction force of the paper P, and the gate member 61 is compared with the case where the interval at which the paper P is conveyed is longer than a predetermined interval. Keep the behavior of. As a result, similarly to the description of FIGS. 8-2 (d) to (f), it is possible to suppress the phenomenon that the collision noise between the gate member 61 and the stopper 611 at the time of switching is not reduced.

  Although the timing for outputting the drive current and the control pattern for controlling the current amount have been described above, the present invention is not limited to this. For example, it is possible to employ a control pattern for controlling the timing for outputting the drive voltage and the voltage amount. In addition, a corresponding means can be considered by performing PWM (Pulse Width Modulation) control and changing each ON / OFF pulse width.

<Description of the program>
The processing performed by the drive control unit 67 and the current control unit 64 described so far is realized by cooperation of software and hardware resources. That is, a CPU (not shown) inside the control computer provided in the drive control unit 67 and the current control unit 64 executes a program that realizes each function of the drive control unit 67 and the current control unit 64, and performs these functions. make it happen.

  Therefore, the process performed by the drive control unit 67 and the current control unit 64 is to selectively move the first position and the second position to the computer by the mechanism unit of the image forming apparatus that forms an image on the recording material. The function of controlling the solenoid 62 that moves between the first position and the second position by increasing or decreasing the force applied to the gate member 61 for switching the recording material conveyance direction at a predetermined time, and recording. A function for calculating the interval at which the recording material is conveyed, and a function for changing the impulse applied to the gate member 61 according to the type of the recording material when the interval at which the recording material is conveyed is smaller than a predetermined interval. It can also be understood as a program that realizes.

DESCRIPTION OF SYMBOLS 60 ... Switching part 61 ... Gate member 62 ... Solenoid 63 ... Spring member 64 ... Current control part 65 ... Paper detection sensor 67 ... Drive control part 671 ... Detection signal acquisition part 672 ... Print job information acquisition Part, 673 ... determination part, R1, R2, R3, R4 ... transport path

Claims (6)

A switching unit that switches the recording material conveyance direction by selectively moving the first position and the second position in a mechanism of an image forming apparatus that forms an image on the recording material;
Moving means for moving the switching means between the first position and the second position by increasing or decreasing the force applied to the switching means at a predetermined time;
With
When the interval at which the recording material is conveyed is smaller than a predetermined interval, the moving unit is arranged so as to cancel the force that the recording material acts on the switching unit according to the type of the recording material. A recording material transport direction switching device, wherein an impulse to be applied is changed. If the interval at which the recording material is transported is smaller than a predetermined interval, the moving unit may transfer the recording material to the switching unit so as to cancel the force acting on the switching unit by the thickness of the recording material . The recording material transport direction switching device according to claim 1, wherein the impulse to be applied is changed.   When the interval at which the recording material is conveyed is smaller than a predetermined interval, the moving unit starts moving at an earlier time than when the interval at which the recording material is conveyed is equal to or greater than the predetermined interval. The recording material transport direction switching device according to claim 1, wherein the recording material transport direction switching device is a recording material transport direction switching device. Toner image forming means for forming a toner image;
Recording material conveying means for conveying the recording material;
Transfer means for transferring the toner image formed by the toner image forming means to the recording material conveyed by the recording material conveying means;
Fixing means for fixing the toner image transferred to the recording material by the transfer means;
Switching means for switching the recording material conveyance direction by selectively moving between the first position and the second position;
Moving means for moving the switching means between the first position and the second position by increasing or decreasing the force applied to the switching means at a predetermined time;
Control means for controlling the moving means;
With
When the interval at which the recording material is conveyed is smaller than a predetermined interval, the control unit is configured to switch the switching unit so as to cancel the force that the recording material acts on the switching unit according to the type of the recording material. An image forming apparatus characterized by changing an impulse to be applied to the image forming apparatus.   The image forming apparatus according to claim 4, wherein the switching unit is provided on a recording material conveyance downstream side of the fixing unit. On the computer,
The force to be applied to the switching means for switching the recording material conveyance direction by selectively moving the first position and the second position in the mechanism of the image forming apparatus that forms an image on the recording material is determined in advance. A function of controlling the moving means for moving the switching means between the first position and the second position by increasing or decreasing in the given time;
A function of calculating an interval at which the recording material is conveyed;
When the interval at which the recording material is conveyed is smaller than a predetermined interval, the impulse that is applied to the switching unit so as to cancel the force that the recording material acts on the switching unit according to the type of the recording material. With the ability to change
A program that realizes

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