JP6855819B2 - Continuous paper transport equipment, fixing equipment, and image forming equipment - Google Patents

Description

The present invention relates to a continuous paper transport device, a fixing device, and an image forming device.

Patent Document 1 describes a movable buffer for the purpose of reducing transfer blurring by reducing the impact when a buffer that absorbs fluctuations in web length generated due to a speed difference between a transfer portion and a fixing portion comes into contact with the web. It is disclosed that a brake is provided in order to suppress the operation of the above.

Further, Patent Document 2 discloses that, for the purpose of dispersing the force at the time of contact from the transfer member to the continuous medium, the contact operation is performed by giving a speed to the transfer of the continuous medium and the rotation of the transfer member. ing.

Japanese Unexamined Patent Publication No. 2005-215427 International Application No. WO2003 / 12554

The present invention is a continuous paper transporting device, a fixing device, and an image forming apparatus that suppress the occurrence of slack in the continuous paper when the continuous paper is sandwiched between two members or released from the sandwiching during continuous paper transport. The purpose is to provide.

Claim 1 is
A first transport member that is in contact with continuous paper and assists in transporting the continuous paper by a transport operation that matches the transport of the continuous paper.
The contact / detachment operation of moving in the direction of contacting / separating with the first conveying member is free, and the continuous paper is sandwiched and pressed against the first conveying member, and the conveying operation is performed in accordance with the conveying of the continuous paper. A second transport member that assists in transporting the continuous paper, and
The continuous paper is passed through a position sandwiched between the first transport member and the second transport member without contributing to the transport of the continuous paper of the first transport member and the second transport member. The transport unit that transports on the transport path and
A first control process in which the second transport member is made to stand by at a separated position away from the first transport member.
After the second control process of causing the first transfer member and the second transfer member to start the transfer operation, and after the start of the transfer operation of the first transfer member and the second transfer member, and After the start of transporting the continuous paper, the control unit is provided with a control unit that performs control including a third control process in which the second transport member is pressed against the first transport member across the continuous paper.
In the third control process, the control unit
In the first operation process in which the second transport member waiting at the separated position moves in a direction approaching the first transport member, the second transport member moves at the first average moving speed.
In the second operation process following the first operation process until the second transfer member reaches the final pressing position pressed against the first transfer member, the second transfer member is subjected to the second operation process. When the second average moving speed is lower than the first average moving speed, and the thickness of the continuous paper is thin according to the thickness of the continuous paper to be conveyed by the conveying unit, the continuous. The continuous paper transport device is characterized in that the movement of the second transport member is controlled so that the moving average speed is lower than that in the case where the paper is thick.

Claim 2
When the control unit has a relatively high transfer speed of the continuous paper according to the transfer speed of the continuous paper to be conveyed by the transfer unit, and when the transfer speed of the continuous paper is relatively low. compared a continuous sheet conveying apparatus according to claim 1, characterized in that reducing the moving average speed of the second conveying member in the second operating process.

Claim 3
The continuous paper transport device according to claim 1 or 2 , wherein the control unit temporarily stops the second transport member in the middle of the first operation process.

Claim 4
A first transport member that is in contact with continuous paper and assists in transporting the continuous paper by a transport operation that matches the transport of the continuous paper.
The contact / detachment operation of moving in the direction of contacting / separating with the first conveying member is free, and the continuous paper is sandwiched and pressed against the first conveying member, and the conveying operation is performed in accordance with the conveying of the continuous paper. A second transport member that assists in transporting the continuous paper, and
The continuous paper is passed through a position sandwiched between the first transport member and the second transport member without contributing to the transport of the continuous paper of the first transport member and the second transport member. The transport unit that transports on the transport path and
A first control process in which the second transport member is made to stand by at a separated position away from the first transport member.
After the second control process of causing the first transfer member and the second transfer member to start the transfer operation, and after the start of the transfer operation of the first transfer member and the second transfer member, and After the start of transporting the continuous paper, the control unit is provided with a control unit that performs control including a third control process in which the second transport member is pressed against the first transport member across the continuous paper.
In the third control process, the control unit follows the first operation process in which the second transport member, which has been waiting at the separated position, moves in a direction approaching the first transport member. In the second operation process in which the transport member of the paper reaches the final pressing position pressed against the first transport member across the continuous paper, the second is at an average moving speed that does not cause slack in the continuous paper. It is a continuous paper transport device characterized by moving a transport member.

Claim 5
A first transport member that is in contact with continuous paper and assists in transporting the continuous paper by a transport operation that matches the transport of the continuous paper.
The contact / detachment operation of moving in the direction of contacting / separating with the first conveying member is free, and the continuous paper is sandwiched and pressed against the first conveying member, and the conveying operation is performed in accordance with the conveying of the continuous paper. A second transport member that assists in transporting the continuous paper, and
The continuous paper is passed through a position sandwiched between the first transport member and the second transport member without contributing to the transport of the continuous paper of the first transport member and the second transport member. The transport unit that transports on the transport path and
The second transport member is maintained at the final pressing position pressed against the first transport member with the continuous paper sandwiched between them, and the transport operation is performed on the first transport member and the second transport member. A control unit that performs control including a fourth control process for continuing the process and a fifth control process for moving the second transport member at the final pressing position to a separated position away from the first transport member. With
In the fifth control process, the control unit moves the second transport member at the final pressing position at a relatively low third average moving speed in a direction away from the first transport member. Following the third operating process and the third operating process, the fourth moving member moves at a fourth moving speed higher than the third average moving speed until the second transport member reaches the separation position. The continuous paper transport device is characterized in that the moving speed pattern of the second transport member is changed so as to realize the operation process of the above.

Claim 6
A heating member that heats the toner image that has been transferred onto the continuous paper and has been transferred while assisting the transfer of the continuous paper by the transfer operation that is in contact with the continuous paper and that matches the transfer of the continuous paper.
The continuous paper can be freely moved in the direction of contacting and separating from the heating member, and the continuous paper is pressed against the heating member by sandwiching the continuous paper to pressurize the continuous paper in accordance with the transportation of the continuous paper. A pressure member that assists in the transfer of the continuous paper by the transfer operation, and
With a transport unit that transports the continuous paper on a transport path via a position sandwiched between the heating member and the pressurizing member without contributing to the transport of the heating member and the continuous paper of the pressurizing member. ,
The first control process of making the pressurizing member stand by at a separated position away from the heating member,
After the second control process of causing the heating member and the pressurizing member to start the transport operation, and after the start of the transport operation of the heating member and the pressurizing member, and after the start of transporting the continuous paper, the addition is performed. It is provided with a control unit that performs control including a third control process in which the pressing member is pressed against the heating member with the continuous paper sandwiched between them.
In the third control process, the control unit follows the first operation process in which the pressurizing member waiting at the separation position moves in a direction approaching the heating member, and the first operation process. The fixing device is characterized in that the speed pattern of movement of the pressurizing member is changed in the second operation process until the pressurizing member reaches the final pressing position pressed against the heating member. ..

Claim 7
The control unit moves the pressurizing member at the first average moving speed in the first operating process, and the pressurizing member is slower than the first average moving speed in the second operating process. The fixing device according to claim 6 , wherein the movement of the pressurizing member is controlled so as to move at the second average moving speed.

Claim 8
When the control unit has a thin continuous paper according to the thickness of the continuous paper to be conveyed by the transport unit, the addition in the second operation process is compared with a case where the continuous paper is thick. a Fixing device according to claim 7, characterized in that to reduce the moving average speed of member.

Claim 9
When the control unit has a relatively high transfer speed of the continuous paper according to the transfer speed of the continuous paper to be conveyed by the transfer unit, and when the transfer speed of the continuous paper is relatively low. compared a Fixing device according to claim 7 or 8, wherein reducing the moving average speed of the pressing member in the second operating process.

Claim 10
The fixing device according to any one of claims 6 to 9 , wherein the control unit temporarily stops the pressurizing member in the middle of the first operation process.

11 .
A heating member that heats the toner image that has been transferred onto the continuous paper and has been transferred while assisting the transfer of the continuous paper by the transfer operation that is in contact with the continuous paper and that matches the transfer of the continuous paper.
The continuous paper can be freely moved in the direction of contacting and separating from the heating member, and the continuous paper is pressed against the heating member by sandwiching the continuous paper to pressurize the continuous paper in accordance with the transportation of the continuous paper. A pressure member that assists in the transfer of the continuous paper by the transfer operation, and
The first control process of making the pressurizing member stand by at a separated position away from the heating member,
After the second control process of causing the heating member and the pressurizing member to start the transport operation, and after the start of the transport operation of the heating member and the pressurizing member, and after the start of transporting the continuous paper, the addition is performed. It is provided with a control unit that performs control including a third control process in which the pressing member is pressed against the heating member with the continuous paper sandwiched between them.
The pressurizing member is the continuous paper following the first operation process in which the control unit moves the pressurizing member waiting at the separated position in the direction approaching the heating member in the third control process. A fixing device characterized in that the pressurizing member is moved at an average moving speed that does not cause slack in the continuous paper in the second operation process of reaching the final pressing position pressed against the heating member with the paper in between. Is.

12 .
A heating member that heats the toner image that has been transferred onto the continuous paper and has been transferred while assisting the transfer of the continuous paper by the transfer operation that is in contact with the continuous paper and that matches the transfer of the continuous paper.
The continuous paper can be freely moved in the direction of contacting and separating from the heating member, and the continuous paper is pressed against the heating member by sandwiching the continuous paper to pressurize the continuous paper in accordance with the transportation of the continuous paper. A pressure member that assists in the transfer of the continuous paper by the transfer operation, and
A fourth control process in which the pressurizing member is maintained at the final pressing position pressed against the heating member with the continuous paper sandwiched therein, and the heating member and the pressurizing member continue the transport operation, and the above. The pressurizing member at the final pressing position is provided with a control unit that performs control including a fifth control process for moving the pressurizing member to a separation position away from the heating member.
A third operation process in which the control unit moves at a relatively low third average moving speed in the direction in which the pressurizing member at the final pressing position moves away from the heating member in the fifth control process. And the fourth operation process following the third operation process, in which the pressurizing member moves at a fourth moving speed higher than the third average moving speed until the pressure member reaches the separation position. As described above, the fixing device is characterized in that the moving speed pattern of the pressurizing member is changed.

13 .
The fixing device according to any one of claims 6 to 12, and the fixing device.
A transport unit that transports the continuous paper on a transport path via a fixing position sandwiched between the heating member and the pressurizing member without contributing to the transport of the heating member and the continuous paper of the pressurizing member. When,
The image forming apparatus is provided with a toner image generation unit that generates a toner image and transfers the toner image onto the continuous paper on the upstream side of the fixing position in the transport direction of the continuous paper.

According to the continuous paper conveying device of claims 1 to 4 , when the second conveying member is pressed against the first conveying member with the continuous paper sandwiched between the first operating process and the second operating process. The occurrence of slack in the continuous paper is suppressed as compared with the case where the first operation process and the second operation process are pressed at the same speed.

According to the continuous paper transport device of claim 5 , the occurrence of slack in the continuous paper when the continuous paper sandwiched between the first transport member and the second transport member is released is suppressed.

According to the fixing device of claims 6 to 11 , the occurrence of slack in the continuous paper when the pressing member is pressed against the heating member with the continuous paper sandwiched between the first operating process and the second operating process. Compared to the case of pressing at the same speed, it is suppressed.

According to the fixing device of claim 12 , the occurrence of slack in the continuous paper when the continuous paper sandwiched between the heating member and the pressurizing member is released is suppressed.

According to the image forming apparatus according to claim 13, in accordance with the dependent source of the claim 13, generation of the continuous paper slack when pressing the pressure member to the heating member across the continuous sheet, or a heating member The occurrence of slack in the continuous paper when the continuous paper sandwiched between the pressurizing members is released is suppressed.

It is a schematic diagram of the image forming apparatus as one Embodiment of this invention. It is a schematic diagram of a fuser. It is a figure which showed the operation flow at the time of power-on of the image forming apparatus shown in FIG. It is a figure which showed the operation flow at the time of receiving a print instruction. It is explanatory drawing of the cause which the continuous paper loosens at the time of latching of a pressure roll. It is explanatory drawing of the problem which may occur when the continuous paper is loosened. It is a figure which showed the latch control method of this embodiment together with the comparative example. It is a figure which showed the correspondence table with the type of continuous paper, and the movement distance of each pressure roll in the 2nd operation process in a latch operation. It is a figure which showed the correspondence table of the transport speed of continuous paper, and the moving distance of each pressure roll in the 2nd operation process in a latch operation. It is a figure which showed the 2nd example of the latch control method. It is a figure which showed the 3rd example of the latch control method. It is a figure which showed an example of the control method of the pressure roll in the separation operation which separates a pressure roll in a final pressing position from a heating roll and moves it to a separation position.

Hereinafter, embodiments of the present invention will be described.

FIG. 1 is a schematic view of an image forming apparatus as an embodiment of the present invention. The image forming apparatus 100 shown in FIG. 1 includes an embodiment of the continuous paper transporting apparatus of the present invention and an embodiment of the fixing apparatus of the present invention.

The image forming apparatus 100 includes a paper feeding unit 110, an image forming unit 120, and a winding unit 130.

A long roll paper P1 wound in a roll shape is mounted on the paper feed unit 110. The roll paper P1 mounted on the paper feed unit 110 is directed toward the image forming unit 120 by the rotation of the roll shaft 111 in the direction of the arrow A and the rotation of the delivery roll 112 by a drive source (not shown). It is sent out as continuous paper P in the direction.

In the image forming unit 120, the continuous paper P fed in the direction of the arrow X1 is conveyed in the direction of the arrow X2 by the conveying member 121, and an image is formed on the continuous paper P in the meantime.

The continuous paper P on which this image is formed is sent to the winding unit 130 in the direction of arrow X3, and is rotationally driven in the direction of arrow B by a drive source (not shown) via a buffer 132 for absorbing the speed difference. It is wound around the roll shaft 131 to be rolled as roll paper P2.

The image forming unit 120 is provided with four image holders 11Y, 11M, 11C, and 11K, each of which rotates in the direction of the arrow Y. Here, Y, M, C, and K mean yellow, magenta, cyan, and black. On the four image holders 11Y, 11M, 11C, and 11K, each toner image is formed by toners of each color through the toner image forming process described below. In the following, in the description common to each color, the symbols Y, M, C, and K indicating the color distinction will be omitted.

Each charger 12 and each developer 13 are provided around each image holder 11. Each charger 12 charges each image holder 11. Further, each developer 13 develops an electrostatic latent image formed on each image holder 11 with toner of each color. Further, the four image holders 11Y, 11M, 11C, and 11K are provided with an exposure device 14 at the upper part. From the exposure device 14, each exposure light 141 modulated with image data corresponding to each color is irradiated toward each image holder 11. Then, on each image holder 11, charging by each charging device 12, formation of an electrostatic latent image by exposure by irradiation of each exposure light 141 from the exposure device 14, and development by each developing device 13 of each color A toner image is formed, and each image holder 11 temporarily holds the formed toner image of each color.

Further, the image forming unit 120 is provided with an intermediate transfer belt 21. The intermediate transfer belt 21 is an endless belt that is supported by a plurality of rolls 22 and circulates in the direction of the arrow Z along a path along the four image holders 11.

Each primary transfer roll 23 is provided at each position where the intermediate transfer belt 21 is sandwiched between the image holder 11 and the image holder 11. Then, each toner image temporarily held on each image holder 11 is transferred onto the intermediate transfer belt 21 by the action of each primary transfer roll 23. The toner image transferred onto the intermediate transfer belt 21 is carried by the intermediate transfer belt 21 in the direction of arrow Z, and is transferred onto the continuous paper P by the action of the secondary transfer roll 24.

The toner image transferred onto the continuous paper P is carried to the continuous paper P and proceeds in the direction of arrow X2, and is sandwiched between the heating roll 31 and the pressure roll 32 constituting the fixing device 30 to heat and pressurize. The toner image is fixed on the continuous paper P. As a result, an image composed of the fixing toner image is formed on the continuous paper P. As described above, the continuous paper P on which this image is formed is fed to the winding unit 130 and wound up to become the roll paper P2.

The image forming apparatus 100 is further provided with a control unit 41 and an operation unit 41. The control unit 41 is in charge of overall control for realizing the above-mentioned image formation process in the image forming apparatus 100. Further, the control unit 41 receives a print instruction including image data transmitted from an external device, temporarily stores the print instruction, controls the exposure machine 14 based on the image data, and causes the exposure device 14 to display the image. The exposure light 141 according to the data is generated.

Further, the operation unit 42 has a role of accepting an operation by the user and transmitting the user operation to the control unit 41. The control unit 41 controls the image forming apparatus 100 so that the operation corresponding to the user operation transmitted from the operation unit 42 is executed.

Here, the feature of the present embodiment is the operation of the fuser 30, and the operation of the fuser 30 will be described below.

FIG. 2 is a schematic view of the fuser.

The fuser 30 includes a heating roll 31 internally provided with a heat source (not shown) for heating by receiving electric power, and a pressure roll 32 for pressing continuous paper P against the heating roll 31. The pressure roll 32 moves up and down in the direction of arrow UD due to the rotation of the cam 33.

The pressure roll 32 shown by a solid line in FIG. 2 is in the final pressing position where the continuous paper P is sandwiched and pressed against the heating roll 31. Further, the pressure roll 32 shown by the alternate long and short dash line in FIG. 2 is at a separated position away from the heating roll 31. Here, the surface of the pressure roll 32 has elasticity, so that the pressure roll 32 at the final pressing position not only comes into contact with the heating roll 31 with the continuous paper P sandwiched between them, but also at the final pressing position. Is pushed up further. When the pressure roll 32 is pushed up to the final push-up position, the pressure roll 32 is slightly crushed by the heating roll 31 to form a fixing nip region N with the heating roll 31. The heating roll 31 is rotationally driven in the direction of arrow R1, and the pressurizing roll 32 is rotationally driven in the direction of arrow R2. As described with reference to FIG. 1, the continuous paper P is conveyed even if the heating roll 31 and the pressure roll 32 do not contribute to the continuous paper transfer, but the heating roll 31 and the pressure roll 32 are conveyed. By rotating with the continuous paper P in between, it also assists in the continuous paper transport.

When the motor 43 instructed by the control unit 41 (see also FIG. 1) rotates, the cam 33 rotates, and the pressure roll 32 is finally pressed by the rotation of the cam 33, which is shown by the solid line in FIG. It moves up and down in the direction of arrow UD between the position and the separated position shown by the alternate long and short dash line in FIG.

FIG. 3 is a diagram showing an operation flow of the image forming apparatus shown in FIG. 1 when the power is turned on. Here, attention is paid to the fuser 30, and FIG. 3 shows an operation flow regarding the fuser 30.

At the stage of turning on the power of the image forming apparatus 100 shown in FIG. 1, the heating roll 32 is placed at a separated position away from the heating roll 31. Then, when the power is turned on (step S01), electric power is supplied to the heat source inside the heating roll 31 to start heating the heating roll 31 (step S02), and each of the heating roll 31 and the pressurizing roll 32 is further started. , Starts low-speed rotation slower than the continuous paper transport speed at the time of actual image formation (step S03). Then, when the heating roll 31 reaches a predetermined standby temperature lower than that at the time of actual image formation (step S04), the standby is completed and the standby state is maintained (step S05). In this standby state, the heating roll 31 is maintained at the standby temperature, and the heating roll 31 and the pressurizing roll 32 maintain low speed rotation. At this time, the pressure roll 32 remains placed at a separated position away from the heating roll 31.

FIG. 4 is a diagram showing an operation flow when a print instruction is received. Here, as in FIG. 3, the operation flow regarding the fuser 30 is shown.

When the print instruction is received in the standby state (step S11) described above (step S12), the heating roll 31 kept at the standby temperature starts heating further from the standby temperature (step S13), and the speed is low. The rotating heating roll 31 and the pressurizing roll 32 start high-speed rotation, which is the speed at the time of image formation (step S14), and the continuous paper P is started to be conveyed (step S15). Then, when the heating roll 31 reaches the fixing target temperature, which is the temperature at the time of image formation (step S16), the pressurizing roll 32 is latched (step S17). Here, latching the heating roll 32 means pushing up the pressure roll 32 at the separated position shown by the alternate long and short dash line in FIG. 2 and moving it to the final pressing position shown by the solid line in FIG. After the latch of the pressure roll 32, the image formation is performed according to the printing instruction as described above.

FIG. 5 is an explanatory diagram of the cause of loosening of the continuous paper when the pressure roll is latched.

In latching the pressure roll 32, the surface speed of the heating roll 31 due to the rotation of the heating roll 31 in the direction of the arrow R1, the surface speed of the pressure roll 32 due to the rotation of the pressure roll 32 in the direction of the arrow R2, and After controlling so that the paper transport speeds are all the same, the pressurizing roll 32 is latched. However, in reality, an error may occur in the rotation speed and the continuous paper transport speed of the heating roll 31 and the pressure roll 32, and a speed difference may occur between them. Then, when a speed difference occurs, a local fluctuation occurs in the continuous paper transport speed when the pressure roll 32 is latched. For example, when the continuous paper transport speed is higher than the surface speed of the heating roll 31 or the pressure roll 32, as shown in FIG. 5A, the front side of the fixing nip region N in the continuous paper transport directions X2 and X3 ( On the upstream side), slack S occurs in the continuous paper P. Alternatively, when the continuous paper transport speed is lower than the surface speed of the heating roll 31 or the pressure roll 32, slack S occurs in the continuous paper P on the downstream side of the fixing nip region N as shown in FIG. 5 (B). ..

FIG. 6 is an explanatory diagram of problems that may occur when the continuous paper is loosened.

As shown in FIG. 5A, when slack S occurs on the front side of the nip region N, the posture of the continuous paper P rushing into the nip region N changes, for example, rushing in an oblique posture or a dogleg in the width direction. There is a possibility that paper wrinkles R may occur as shown in FIG. 6 (A) due to bending and rushing into the paper. Once the paper wrinkle R is generated, the paper wrinkle R continues to be formed when passing through the nip region N, and the image formed on the continuous paper P may also be wrinkled. ..

Further, as shown in FIG. 5 (B), when slack S occurs on the downstream side of the nip region N, the continuous paper P meanders, and the continuous paper P is wound up by the winding portion 130 (see FIG. 1) and rolled. When paper P2 is used, winding failure W may occur due to meandering in the axial direction of winding.

In the present embodiment, the occurrence of slack S on the continuous paper P is suppressed by the latch control described below.

FIG. 7 is a diagram showing the latch control method of the present embodiment together with a comparative example.

The horizontal axis t in FIG. 7 is the time axis. Further, the vertical axis d in FIG. 7 represents the position of the pressure roll 32 in the arrow UD direction (see also FIG. 2). The “nip start position” represents a position where the pressure roll 32 just contacts the heating roll 31 with the continuous paper P sandwiched between them.

In the case of the comparative example shown by the alternate long and short dash line in FIG. 7, the latch operation start instruction is given at the latch start time t1, the pressure roll 32 at the separated position starts to rise toward the heating roll 31, and the pressure roll 32 starts to rise. , Moves to the final pressing position at a constant speed.

On the other hand, in the case of the present embodiment, the pressure roll 32 at the separated position moves at the same speed as the comparative example up to the nip start position, but after the nip start position, the pressure roll 32 is gradually moved (distance d0). It moves to the final pressing position while repeating the operation of stopping for a while, waiting for the stress between the continuous paper P to be relieved, and moving by a distance d0 and stopping for a while. As a result, it is possible to prevent the continuous paper P from being subjected to sudden stress to generate slack S. Here, the movement of moving the pressure roll 31 at the separated position to the nip start position corresponds to an example of the first operation process referred to in the present invention, and the pressure roll 32 moved to the nip start position is moved to the final pressing position. The movement to move to corresponds to an example of the second operation process referred to in the present invention. Here, since the pressurizing roll 32 advances stepwise after moving to the nip start position, the pressurizing roll 32 moves at an average moving speed lower than that of the first operating process in the second operating process. It will be.

In the case of the latch control shown in FIG. 7, the motor 43 (see FIG. 2) for moving the pressurizing roll 32 needs to rotate / stop, but the speed at the time of rotation is a constant speed and has a speed variable function. Is unnecessary.

FIG. 8 is a diagram showing a correspondence table between the types of continuous paper and the moving distance (distance d0 shown in FIG. 7) of the pressurizing roll in the second operation process in the latch operation. This correspondence table is created in advance and stored in the control unit 41 (see FIGS. 1 and 2).

In the image forming apparatus 100 shown in FIG. 1, three types of continuous paper A, continuous paper B, and continuous paper C, which are different types of continuous paper P, can be used as the continuous paper P. Here, when the paper thicknesses of the continuous papers A, B, and C of each type are compared, the continuous paper A is the thinnest, and the continuous paper B has an intermediate thickness between the continuous paper A and the continuous paper C. Is the thickest continuous paper. In this case, the smallest movement distance a in the case of the thinnest continuous paper A is set as the movement distance per stepwise movement (distance d0 shown in FIG. 7) in the second operation process in the latch operation. Further, as the continuous papers B and C become thicker, the larger moving distances b and c are set in order as the moving distance per one time.

In the image forming apparatus 100 shown in FIG. 1, when the roll paper P1 is mounted on the paper feeding unit 110, the type of continuous paper P constituting the mounted roll paper P1 is determined by the user operation of the operation unit 42. Entered. Then, the control unit 41 finally controls the pressurizing roll 32 by the moving distance per time according to the type of the input continuous paper P in controlling the second operation process of the latch operation of the pressurizing roll 32. Move to the pressing position. Here, the stop time per stop is constant. This means that the thinner the continuous paper P, the lower the average moving speed of the pressure roll 32 in the second operation process. The thinner the paper thickness, the larger the fluctuation of the continuous paper transport speed due to the load fluctuation, and the slack S is likely to occur. Therefore, here, according to the paper thickness, the thinner the paper thickness, the lower the average moving speed to suppress the occurrence of slack S.

FIG. 9 is a diagram showing a correspondence table between the transport speed of continuous paper and the moving distance of each pressure roll in the second operation process in the latch operation. This correspondence table is also created in advance and stored in the control unit 41 (see FIGS. 1 and 2).

In the image forming apparatus 100 shown in FIG. 1, three types of speeds D, E, and F, which are different speeds, can be set as the transport speed of the continuous paper P. Here, when the respective transport speeds D, E, and F are compared, the transport speed D is the slowest, the transport speed E is an intermediate speed between the transport speed D and the transport speed F, and the transport speed F is the lowest. High transport speed. In this case, when the slowest transfer speed D is specified as the movement distance per stepwise movement (distance d0 shown in FIG. 7) in the second operation process in the latch operation, the largest movement distance d is set. Set. Further, as the transport speeds E and F and the transport speed become higher, smaller travel distances e and f are set in order as the travel distance per time.

In the image forming apparatus 100 shown in FIG. 1, when the roll paper P1 mounted on the paper feeding unit 110 is started to be conveyed, the continuous transfer speed of this time is input by the user operation of the operation unit 42. Then, the control unit 41 conveys the continuous paper P according to the input continuous paper conveying speed, and controls the second operation process of the latch operation of the pressurizing roll 32 according to the continuous paper conveying speed 1. The pressurizing roll 32 is moved to the final pressing position by the moving distance per rotation. Here, the stop time per stop is constant. This means that the higher the transport speed of the continuous paper P, the lower the average moving speed of the pressure roll 32 in the second operation process. The higher the transport speed of the continuous paper P, the larger the fluctuation of the continuous paper transport speed due to the load fluctuation, and the slack S is likely to occur. Therefore, here, according to the transport speed of the continuous paper P, the higher the transport speed of the continuous paper P, the lower the average moving speed and the occurrence of slack S is suppressed.

Here, for the sake of clarity, the paper thickness of the continuous paper P (FIG. 8) and the transport speed of the continuous paper P (FIG. 9) have been described separately, but a plurality of types of continuous paper having different paper thicknesses have been described separately. In the case of the image forming apparatus 100 in which the continuous paper transfer speed can be switched to a plurality of stages, the continuous paper type shown in FIG. 8 and the continuous paper transfer speed shown in FIG. 9 are two variables. A correspondence table for determining the movement distance per movement is stored in the control unit 41 and is referred to during the latch operation. In the case of the correspondence table between these two variables and the moving distance per time, as in the above, the thinner the continuous paper and the faster the conveying speed of the continuous paper, the more the moving distance per time. Is set small.

FIG. 10 is a diagram showing a second example of the latch control method. FIG. 10 also shows a comparative example also shown in FIG. 7 for comparison.

The horizontal axis t of FIG. 10 is the time axis, and the vertical axis d represents the position of the pressure roll 32 in the arrow UD direction (see also FIG. 2 together).

In the case of the second example shown in FIG. 10, the pressure roll 32 at the separated position moves at the same speed in the comparative example and the first example shown in FIG. 7 in the first operation process up to the nip start position. Then, in the subsequent second operation process, it is continuously pushed up at a lower speed than the first operation process. The operating speed of the pressure roll 32 in this second operating process is a speed that avoids sudden stress on the continuous paper P and avoids causing slack S in the continuous paper P. As shown in this second example, the second operating process may be configured to be continuously pushed up at a lower speed than the first operating process. However, in the case of this second example, it is necessary to adjust the displacement amount per hour according to the rotation position of the cam 33 (see FIG. 2) or to use the motor 43 (see FIG. 2) having a variable rotation speed.

The moving speed of the pressure roll 32 in the second operation process is changed according to the thickness of the continuous paper P or the continuous paper transport speed described with reference to the second example and FIGS. 8 and 9. It may be combined with what to do. In that case, the continuous moving speed of the pressure roll 32 in the second operation process is adjusted.

FIG. 11 is a diagram showing a third example of the latch control method. Also in FIG. 11, for comparison, the same comparative example as the comparative example shown in FIGS. 7 and 10 is shown.

Similar to FIGS. 7 and 10, in FIG. 11, the horizontal axis t represents the time axis, and the vertical axis d represents the position of the pressure roll 32 in the arrow UD direction (see also FIG. 2). There is.

In the case of the third example shown in FIG. 11, at the time t2 (step S12 shown in FIG. 4) when the print instruction is received, which is a time before the latch operation start time t1 (step S17 shown in FIG. 4) in the conventional example. The latch operation of the pressure roll 32 is started.

The moving speed of the pressure roll 32 is such that even if the pressure roll 32 is pressed against the heating roll 31 with the continuous paper P sandwiched between them, not only in the second operation process but also in the first operation process. The speed is slow enough not to cause slack S in P.

In this third example, the pressurizing roll 32 starts operation at time t2 when the print instruction is received, moves at a slow speed, stops at a position before the nip start position, and stands by at that position. Then, the operation is performed at the time when the heating roll 32 in the comparative example reaches the nip start position after reaching the nip operation start time t1 in the comparative example after the heating roll 31 reaches the fixing target temperature. It starts again and moves to the final pressing position at a slow speed that does not cause slack S in the continuous paper P. In the case of this third example, by starting the operation at an early time t2 and waiting, the slack S to the continuous paper P without changing the rotation speed at the time of rotation of the motor 43 (see FIG. 2) in the middle. Is suppressed.

It should be noted that the pressure roll 32 in the second operation process depends on the paper thickness of the continuous paper P or the continuous paper transport speed described with reference to the third example shown in FIG. 11 and FIGS. 8 and 9. It may be combined with changing the moving speed. In that case, the continuous moving speed of the pressurizing roll 32 in both the first operating process and the second operating process is adjusted by using the motor 43 having a variable rotation speed.

In the description of FIGS. 7, 10 and 11, the operation until the pressurizing roll 32 in the standby position reaches the nip start position is set as the first operation process, and the operation reaches the final pressing position from the nip start position. The second operation process is defined as the operation until the movement is performed. However, the first operation process and the second operation process are separated. For example, the bending point of the moving speed in FIG. 10 does not have to be exactly at the nip start position. It may be slightly before (closer to the separation position) than the nip start position, or slightly ahead (closer to the final pressing position).

FIG. 12 is a diagram showing an example of a method for controlling the pressure roll in the separation operation in which the pressure roll at the final pressing position is separated from the heating roll and moved to the separation position. In FIG. 12, as in FIG. 7, the horizontal axis t indicates the time axis, and the vertical axis d indicates the position of the pressure roll in the arrow UD direction.

When the pressure roll 32 is instructed to separate at time t3, the pressure roll 32 at the final pressing position starts moving toward the separation position, but moves from the final pressing position until it reaches the nip start position. And stop are repeated alternately, and when the nip start position is reached, it continuously moves to the standby position. The movement of the pressure roll 32 from the final pressing position to the nip start position corresponds to an example of the third operation process referred to in the present invention, and the movement from the nip start position to the standby position is referred to in the present invention. It corresponds to an example of the operation process of 4. In the example shown in FIG. 12, repeating the movement and the stop alternately in the third operation process means that the average moving speed is reduced. Even in the situation where the pressure roll 32 is separated, the stress applied to the continuous paper P is alleviated by slowly separating the pressure roll 32 until it passes through the nip start region, and the speed fluctuation of the continuous paper P is suppressed. be able to.

The example shown in FIG. 12 is an example in which the operation of the pressurizing roll 32 in the latch control shown in FIG. 7 is traced in the reverse direction. The operation of the pressurizing roller 32 in the latch control shown may be traced in the opposite direction. Further, as in the case of the latch control, the separation between the third operation process and the fourth operation process does not have to be exactly at the nip start position, and may be a position from the final pressing position rather than the nip start position. Alternatively, the position may be closer to the separation position than the nip start position.

Further, also in the scene of this separation operation, the thinner the continuous paper P or the faster the continuous paper transport speed, which is described with reference to FIGS. 8 and 9, the more the addition in the third operation process is performed. Control may be performed to reduce the average moving speed of the pressure roll 32.

Here, the fixing device 30 composed of a combination of the heating roll 31 and the pressure roll 32 in the image forming apparatus 100 shown in FIG. 1 has been taken up and described, but the present invention has, for example, an endless belt shape instead of the heating roll 31. The same can be applied to a fuser or the like provided with a heating member.

Further, although the operation of the pressurizing roll 32 of the fixing device 30 of the image forming apparatus 100 shown in FIG. 1 has been taken up and described here, the secondary transfer roll 24 shown in FIG. 1 is brought into contact with and separated from the intermediate transfer belt 21. In the case of the configuration, the present invention may be applied to the operation of contacting and detaching the secondary transfer roll 24.

Further, the present invention is not only applied to the image forming apparatus, but can be widely applied to the continuous paper conveying apparatus for conveying continuous paper.

24 Secondary transfer roll 30 Fixer 31 Heating roll 33 Pressurizing roll 41 Control unit 42 Operation unit 43 Motor 100 Image forming device 110 Feeding unit 120 Image forming unit 130 Winding unit P Continuous paper

Claims (13)

A first transport member that is in contact with continuous paper and assists in transporting the continuous paper by a transport operation that matches the transport of the continuous paper.
The contact / detachment operation of moving in the direction of contacting / separating with the first conveying member is free, and the continuous paper is sandwiched and pressed against the first conveying member, and the conveying operation is performed in accordance with the conveying of the continuous paper. A second transport member that assists in transporting the continuous paper, and
The continuous paper is passed through a position sandwiched between the first transport member and the second transport member without contributing to the transport of the continuous paper of the first transport member and the second transport member. The transport unit that transports on the transport path and
A first control process in which the second transport member is made to stand by at a separated position away from the first transport member.
After the second control process of causing the first transfer member and the second transfer member to start the transfer operation, and after the start of the transfer operation of the first transfer member and the second transfer member, and After the start of transporting the continuous paper, the control unit is provided with a control unit that performs control including a third control process in which the second transport member is pressed against the first transport member across the continuous paper.
In the third control process, the control unit
In the first operation process in which the second transport member waiting at the separated position moves in a direction approaching the first transport member, the second transport member moves at the first average moving speed.
In the second operation process following the first operation process until the second transfer member reaches the final pressing position pressed against the first transfer member, the second transfer member is subjected to the second operation process. When the second average moving speed is lower than the first average moving speed, and the thickness of the continuous paper is thin according to the thickness of the continuous paper to be conveyed by the conveying unit, the continuous. A continuous paper transport device, characterized in that the movement of the second transport member is controlled so that the moving average speed is lower than that when the paper is thick. When the control unit has a relatively high transfer speed of the continuous paper according to the transfer speed of the continuous paper to be conveyed by the transfer unit, and when the transfer speed of the continuous paper is relatively low. compared, continuous paper conveying apparatus of claim 1, wherein the reducing the moving average speed of the second conveying member in the second operating process. The continuous paper transport device according to claim 1 or 2 , wherein the control unit temporarily stops the second transport member in the middle of the first operation process. A first transport member that is in contact with continuous paper and assists in transporting the continuous paper by a transport operation that matches the transport of the continuous paper.
The contact / detachment operation of moving in the direction of contacting / separating with the first conveying member is free, and the continuous paper is sandwiched and pressed against the first conveying member, and the conveying operation is performed in accordance with the conveying of the continuous paper. A second transport member that assists in transporting the continuous paper, and
The continuous paper is passed through a position sandwiched between the first transport member and the second transport member without contributing to the transport of the continuous paper of the first transport member and the second transport member. The transport unit that transports on the transport path and
A first control process in which the second transport member is made to stand by at a separated position away from the first transport member.
After the second control process of causing the first transfer member and the second transfer member to start the transfer operation, and after the start of the transfer operation of the first transfer member and the second transfer member, and After the start of transporting the continuous paper, the control unit is provided with a control unit that performs control including a third control process in which the second transport member is pressed against the first transport member across the continuous paper.
In the third control process, the control unit follows the first operation process in which the second transport member, which has been waiting at the separated position, moves in a direction approaching the first transport member. In the second operation process in which the transport member of the paper reaches the final pressing position pressed against the first transport member across the continuous paper, the second is at an average moving speed that does not cause slack in the continuous paper. A continuous paper transport device characterized by moving transport members. A first transport member that is in contact with continuous paper and assists in transporting the continuous paper by a transport operation that matches the transport of the continuous paper.
The contact / detachment operation of moving in the direction of contacting / separating with the first conveying member is free, and the continuous paper is sandwiched and pressed against the first conveying member, and the conveying operation is performed in accordance with the conveying of the continuous paper. A second transport member that assists in transporting the continuous paper, and
The continuous paper is passed through a position sandwiched between the first transport member and the second transport member without contributing to the transport of the continuous paper of the first transport member and the second transport member. The transport unit that transports on the transport path and
The second transport member is maintained at the final pressing position pressed against the first transport member with the continuous paper sandwiched between them, and the transport operation is performed on the first transport member and the second transport member. A control unit that performs control including a fourth control process for continuing the process and a fifth control process for moving the second transport member at the final pressing position to a separated position away from the first transport member. With
In the fifth control process, the control unit moves the second transport member at the final pressing position at a relatively low third average moving speed in a direction away from the first transport member. Following the third operating process and the third operating process, the fourth moving member moves at a fourth moving speed higher than the third average moving speed until the second transport member reaches the separation position. A continuous paper transport device, characterized in that the moving speed pattern of the second transport member is changed so as to realize the operation process of the above. A heating member that heats the toner image that has been transferred onto the continuous paper and has been transferred while assisting the transfer of the continuous paper by the transfer operation that is in contact with the continuous paper and that matches the transfer of the continuous paper.
The continuous paper can be freely moved in the direction of contacting and separating from the heating member, and the continuous paper is pressed against the heating member by sandwiching the continuous paper to pressurize the continuous paper in accordance with the transportation of the continuous paper. A pressure member that assists in the transfer of the continuous paper by the transfer operation, and
With a transport unit that transports the continuous paper on a transport path via a position sandwiched between the heating member and the pressurizing member without contributing to the transport of the heating member and the continuous paper of the pressurizing member. ,
The first control process of making the pressurizing member stand by at a separated position away from the heating member,
After the second control process of causing the heating member and the pressurizing member to start the transport operation, and after the start of the transport operation of the heating member and the pressurizing member, and after the start of transporting the continuous paper, the addition is performed. It is provided with a control unit that performs control including a third control process in which the pressing member is pressed against the heating member with the continuous paper sandwiched between them.
In the third control process, the control unit follows the first operation process in which the pressurizing member waiting at the separation position moves in a direction approaching the heating member, and the first operation process. A fixing device characterized in that the speed pattern of movement of the pressurizing member is changed in the second operation process until the pressurizing member reaches the final pressing position pressed against the heating member. The control unit moves the pressurizing member at the first average moving speed in the first operating process, and the pressurizing member is slower than the first average moving speed in the second operating process. A claim characterized in that the movement of the pressurizing member is controlled so as to move at the second average moving speed.
6. The fixing device according to 6. When the control unit has a thin continuous paper according to the thickness of the continuous paper to be conveyed by the transport unit, the addition in the second operation process is compared with a case where the continuous paper is thick. constant Chakusochi of claim 7, wherein reducing the moving average speed of member. When the control unit has a relatively high transfer speed of the continuous paper according to the transfer speed of the continuous paper to be conveyed by the transfer unit, and when the transfer speed of the continuous paper is relatively low. compared constant Chakusochi according to claim 7 or 8, wherein reducing the moving average speed of the pressing member in the second operating process. The fixing device according to any one of claims 6 to 9 , wherein the control unit temporarily stops the pressurizing member in the middle of the first operation process. A heating member that heats the toner image that has been transferred onto the continuous paper and has been transferred while assisting the transfer of the continuous paper by the transfer operation that is in contact with the continuous paper and that matches the transfer of the continuous paper.
The continuous paper can be freely moved in the direction of contacting and separating from the heating member, and the continuous paper is pressed against the heating member by sandwiching the continuous paper to pressurize the continuous paper in accordance with the transportation of the continuous paper. A pressure member that assists in the transfer of the continuous paper by the transfer operation, and
The first control process of making the pressurizing member stand by at a separated position away from the heating member,
After the second control process of causing the heating member and the pressurizing member to start the transport operation, and after the start of the transport operation of the heating member and the pressurizing member, and after the start of transporting the continuous paper, the addition is performed. It is provided with a control unit that performs control including a third control process in which the pressing member is pressed against the heating member with the continuous paper sandwiched between them.
The pressurizing member is the continuous paper following the first operation process in which the control unit moves the pressurizing member waiting at the separated position in the direction approaching the heating member in the third control process. A fixing device characterized in that the pressurizing member is moved at an average moving speed that does not cause slack in the continuous paper in the second operation process of reaching the final pressing position pressed against the heating member with the paper in between. .. A heating member that heats the toner image that has been transferred onto the continuous paper and has been transferred while assisting the transfer of the continuous paper by the transfer operation that is in contact with the continuous paper and that matches the transfer of the continuous paper.
The continuous paper can be freely moved in the direction of contacting and separating from the heating member, and the continuous paper is pressed against the heating member by sandwiching the continuous paper to pressurize the continuous paper in accordance with the transportation of the continuous paper. A pressure member that assists in the transfer of the continuous paper by the transfer operation, and
A fourth control process in which the pressurizing member is maintained at the final pressing position pressed against the heating member with the continuous paper sandwiched therein, and the heating member and the pressurizing member continue the transport operation, and the above. The pressurizing member at the final pressing position is provided with a control unit that performs control including a fifth control process for moving the pressurizing member to a separation position away from the heating member.
A third operation process in which the control unit moves at a relatively low third average moving speed in the direction in which the pressurizing member at the final pressing position moves away from the heating member in the fifth control process. And the fourth operation process following the third operation process, in which the pressurizing member moves at a fourth moving speed higher than the third average moving speed until the pressure member reaches the separation position. As described above, the fixing device is characterized by changing the moving speed pattern of the pressurizing member. The fixing device according to any one of claims 6 to 12, and the fixing device.
A transport unit that transports the continuous paper on a transport path via a fixing position sandwiched between the heating member and the pressurizing member without contributing to the transport of the heating member and the continuous paper of the pressurizing member. When,
An image forming apparatus including a toner image generation unit that generates a toner image and transfers the toner image onto the continuous paper on the upstream side of the fixing position with respect to the transport direction of the continuous paper.

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