JP2009227374A - Paper feeder and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeder capable of favorably separating stacked paper, and an image forming device. <P>SOLUTION: This image forming device 10 includes a loading device 100 on which paper is placed, a separating device 200 for separating the paper placed on the loading device 100 by supplying an airflow thereto, a feed roll 302 for feeding the paper separated by the separating device 200, a pressing device 400 for pressing the feed roll 302 against the paper, a feed state detection device 500 for detecting the feed state of the paper fed by the feed roll 302, and a control device 800 for controlling the pressing force of the pressing device 400 against the feed roll 302 based on the result of the detection by the feed state detection device 500. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sheet feeding device and an image forming apparatus.

  The contact member is pressed against the stacked sheets, and the contact surface of the contact member with the sheet is moved in a predetermined direction to send out the sheets; and air toward the stacked surface of the stacked sheets Spraying means for spraying, sheet speed measuring means for measuring the moving speed of the sheet, contact surface speed measuring means for measuring the moving speed of the contact surface, and the moving speed of the sheet measured by the sheet speed measuring means And a control means for controlling spraying by the spraying means in accordance with a speed difference between the contact surface moving speed measured by the contact surface speed measuring means (Patent Document 1). .

JP 2006-27843 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeding device and an image forming apparatus that can satisfactorily separate stacked paper.

  The first feature of the present invention is that a stacking unit on which sheets are stacked, a separation device that supplies an air current to separate sheets stacked on the stacking unit, and a sheet separated by the separation device A feed member that feeds the feed member toward the downstream side in the transport direction, a pressing unit that presses the feed member against the paper, a transport state detection unit that detects a transport state of the paper fed by the feed member, and the transport And a load control unit configured to control a pressing force of the pressing unit to the delivery member based on a detection result of the state detection unit.

  Preferably, the conveyance state detection means includes a rotating member that contacts the sheet and rotates along with the conveyance of the sheet, and a sheet movement amount measurement unit that measures the movement amount of the sheet from the rotation amount of the rotation member. The load control unit controls the pressing force of the pressing unit to the feeding member based on the sheet moving amount measured by the sheet moving amount measuring unit.

  Preferably, the detection means includes a rotating member that contacts the sheet and rotates with the sheet, a sheet movement amount measuring unit that measures a movement amount of the sheet from the rotation amount of the rotating member, and a sheet of the feeding member. A contact surface movement amount measuring unit that measures a movement amount of the contact surface that is in contact, and the control unit is configured to measure the movement amount of the contact surface measured by the contact surface movement amount measurement unit and the paper movement amount. The pressing force of the pressing unit to the feeding member is controlled based on the difference from the sheet movement amount measured by the measuring unit.

  Preferably, the rotating member moves up and down following a sheet that moves up and down by an air flow supplied from the separation device.

  Preferably, the rotating member is rotatably supported, and further includes a swinging member that is swingably supported by a support shaft, and the rotation shaft of the rotating member is in a paper transport direction than the support shaft. In FIG.

  Preferably, the rotating member regulates the rising of the sheet due to the airflow supplied from the separation device.

  The second feature of the present invention is that a stacking unit on which sheets are stacked, a separation device that supplies an air flow to separate the sheets stacked on the stacking unit, and a sheet separated by the separation device A feeding member that feeds the sheet toward the downstream side in the transport direction, a pressing unit that presses the feeding member against the sheet, and a floating state detection unit that detects a floating state of the sheet due to the airflow supplied by the separation unit, And a load control unit configured to control a pressing force of the pressing unit to the delivery member based on a detection result of the floating state detection unit.

  Preferably, the load control unit controls the pressing force of the pressing unit to the feeding member based on the height of the floated sheet detected by the floating state detection unit.

  Preferably, the load control means has the floating state detection means, and is based on an image photographed by the photographing means for photographing the sheets stacked in a direction perpendicular to the sheet stacking direction. The pressing force to the delivery member is controlled.

  Preferably, a setting unit that sets an initial value of the pressing force of the pressing unit to the feeding member according to at least one of a sheet feeding speed by the feeding member and a sheet feeding interval by the feeding member. It has further.

  Preferably, it further has an airflow control means for controlling the airflow supplied from the distribution device.

  Preferably, the airflow control means controls the airflow according to at least one of the type of paper and the size of the paper.

  According to a third aspect of the present invention, a stacking unit on which sheets are stacked, a separation device that supplies an air current to separate sheets stacked on the stacking unit, and a sheet separated by the separation device A feed member that feeds the paper toward the downstream side in the transport direction, an image forming unit that forms an image on the paper fed by the feed member, a pressing unit that presses the feed member against the paper, and the feed member An image having conveyance state detection means for detecting the conveyance state of the fed paper, and load control means for controlling the pressing force of the pressing means to the delivery member based on a detection result by the conveyance state detection means. In the forming device.

  According to a fourth aspect of the present invention, a stacking unit on which sheets are stacked, a separation device that supplies an air current to separate the sheets stacked on the stacking unit, and a sheet separated by the separation device A feeding member that feeds the sheet toward the downstream side in the conveying direction, an image forming unit that forms an image on the sheet fed by the feeding member, a pressing unit that presses the feeding member against the sheet, and a separation unit A levitation state detection means for detecting a levitation state of the paper by the supplied air flow; and a load control means for controlling a pressing force of the pressing means to the delivery member based on a detection result by the levitation state detection means. An image forming apparatus having the same.

  According to the present invention, it is possible to provide a paper feeding device and an image forming apparatus that can satisfactorily separate stacked paper.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an outline of an image forming apparatus 10 according to the first embodiment of the present invention.
The image forming apparatus 10 includes an image forming apparatus main body 12. A discharge unit 16 is provided on the image forming apparatus main body 12, and the image forming unit 14 and paper are stacked in the image forming apparatus main body 12. A stacking device 100 used as a stacking unit, a separating device 200 that separates sheets stacked on the stacking device 100, and a feeding roll 302 used as a feeding member that feeds the sheets separated by the separating device 200 toward the downstream side in the transport direction. , A feeding device 300 having pressure, a pressing device 400 used as a pressing means for pressing the feeding roll 302 against the paper, and a conveyance state detection used as a conveyance state detection means for detecting the conveyance state of the paper fed by the feeding roll 302. Used as device 500 and load control means, used as airflow control means Is, the control device 800 to be used as a setting unit is mounted.

Further, a conveyance path 18 used for conveying paper is formed in the image forming apparatus main body 12, and an operation panel 850 used as an operation unit is provided on the front side (left side in FIG. 1) of the image forming apparatus main body 12. Is attached.
The operation panel 850 includes a numeric keypad and is used to input the number of sheets on which image formation is performed, the type and size of sheets on which image formation is performed, and the like. Note that an operation device such as a personal computer connected to the control device 800 is used instead of inputting the number of sheets on which image formation is performed, the type and size of the sheets on which image formation is performed, from the operation panel 850. It is also possible to input from (not shown).

  The image forming unit 14 is of an electrophotographic system, and is a drum-shaped photoconductor 20 used as an image carrier, a charging device 22 that uniformly charges the photoconductor 20, and a photoconductor 20 charged by the charging device 22. An optical writing device 24 that writes a latent image with light on the surface, a developing device 26 that develops and visualizes the latent image on the surface of the photoreceptor 20 formed by the optical writing device 24 with a developer, and a development that is visualized by the developing device 26 A transfer device 28 composed of, for example, a transfer roll that transfers the agent image to the paper, a cleaning device 30 that cleans the developer remaining on the photoreceptor 20, and a developer image on the paper transferred by the transfer device 28 is fixed on the paper. And a fixing device 32 to be operated. Among the members constituting the image forming unit 14, the photoconductor 20, the charging device 22, the developing device 26, and the cleaning device 30 are integrated as an image forming structure 34, for example, from the front side of the image forming apparatus main body 12. It can be attached to and detached from the image forming apparatus main body 12.

  The stacking apparatus 100 can be pulled out, for example, to the front side of the image forming apparatus main body 12, or can be attached to and detached from the image forming apparatus main body 12 from, for example, the front side of the image forming apparatus main body 12, and can be pulled out or removed from the image forming apparatus main body 12. The paper can be replenished in the state of being damaged.

  The loading device 100 is connected to the loading device main body 102, the lifting plate 104 that can be moved up and down relative to the loading device main body 102, and the lifting plate 104 for moving the lifting plate 104 up and down relative to the loading device main body 102. And a motor 106 used as a drive source. In the stacking apparatus 100, the remaining amount of paper is detected by a remaining amount sensor (not shown), and the lift plate 104 is moved up and down by controlling the motor 106 according to the detection result of the remaining amount sensor. Regardless, the sheet P1 positioned at the top of the lifting plate 104 is arranged at a fixed position in the height direction.

  In the image forming apparatus main body 12, the feeding device 300, the transporting roll 36 and the separating roll 38, the registration roll 40, the above-described transfer device 28, and the like, in order from the upper side in the paper transporting direction along the transporting path 18. The fixing device 32 and the discharge roll 42 described above are provided. The transport roll 36 is used for transporting the sheet fed by the feed roll 302 toward the downstream side. The separating roll 38 is provided so as to come into contact with the conveying roll 36 and has a function of separating and separating the sheet fed from the feeding roll 302. For this reason, even if two or more sheets are sent out in a state where two or more sheets are not overlapped by the separating apparatus 200, the sheets are separated by the separating roll 38. The registration roll 40 is used to supply the sheet fed from the feeding device 300 to the contact portion between the photoconductor 20 and the transfer device 28 at the timing when the image forming unit 14 forms an image. The discharge roll 42 is used to discharge the sheet on which the developer image has been fixed by the fixing device 32 to the discharge unit 16.

  A detection sensor 550 for detecting paper is mounted at a position downstream of the transport roll 36 and the separating roll 38 in the paper transport direction. A signal from the detection sensor 550 is input to the control device 800.

  In the image forming apparatus 10 configured as described above, the photosensitive member 20 is uniformly charged by the charging device 22, and light emitted from the optical writing device 24 based on the image signal is applied to the charged photosensitive member 20. Irradiation forms a latent image, and this latent image is developed by the developer of the developing device 26 to form a developer image. On the other hand, the sheets stacked on the stacking apparatus 100 are separated by the separating apparatus 200, the separated sheets are sent out by the sending-out apparatus 300, and the sent-out sheets are image-formed by the image forming unit 14 by the registration roll 40. The developer image is transferred between the transfer device 28 and the photosensitive member 20 so as to be synchronized with the transfer device 28, and the developer image is transferred to the supplied paper by the transfer device 28. The transferred developer image is transferred to a sheet by the fixing device 32, and the sheet on which the developer image is transferred is discharged to the discharge unit 16 by the discharge roll 42.

  FIG. 2 shows a separation device 200, a delivery device 300, a pressing device 400, and a conveyance state detection device 500.

  As shown in FIG. 2, the separation device 200 is attached to the right side of the stacked paper, and can supply airflow from the right side to the stacked paper. Details of the separation device 200 will be described later.

  The delivery device 300 has a delivery roll 302 that is used as a delivery member that feeds the paper separated by the separation device 200 toward the downstream side in the transport direction as described above, and is a drive that drives the delivery roll 302 to the delivery roll 302. A motor M2 used as a source is connected using a gear G1, a gear G2, a gear G3, a gear G4, and a gear G5. The delivery roll 302 can move between a position contacting the uppermost sheet P1 and a position spaced from the sheet P1, as shown in FIG. The motor M2 is connected to the control device 800 and is controlled by the control device 800.

The pressing device 400 includes a frame body 404 that is rotatably supported using a shaft 402 with respect to the image forming apparatus main body 12, a gear G12, and a motor M1.
The frame 404 supports the gear G3, the gear G4, the gear G5, and the feed roll 302 described above so that the gear G3, the gear G4, the gear G5, and the feed roll 302 can rotate. The body 404 and the image forming apparatus main body 12 can be moved so as to rotate together with the body 404. Further, a protrusion is formed on a part of the right side plate of the frame 404, for example, and a gear G10 is formed on the protrusion.

  A motor M1 is connected to the gear G10 via a gear G12. Therefore, when the motor M1 is driven, the drive is transmitted to the frame body 404 via the gears G12 and G10, and the frame body 404 moves so as to rotate about the shaft 402. By moving the frame body 404, the feed roll 302 mounted on the frame body 404 moves as a unit with the frame body 404. For this reason, the delivery roll 302 can move between a position where it contacts the paper P1 and is pressed against the paper P1, and a position where it does not contact the paper P1, and the paper roll 302 is moved according to the position of the frame 404. The pressing force (load) with respect to P1 changes. The motor M1 is connected to the control device 800 and controlled by the control device 800.

  The conveyance state detection device 500 is connected to the roller 502 used as a rotating member that contacts the paper P1 and rotates with the paper P1, and the paper movement that is connected to the roller 502 and measures the movement amount of the paper P1 from the rotation amount of the roller 502. A first rotary encoder 504 used as a quantity measuring unit. The output from the first rotary encoder 504 is input to the control device 800. Details of the transport state detection device 500 will be described later.

FIG. 3 shows a separation device 200.
The separation device 200 includes a hollow container 202 in which a blowout port 204 used as an airflow ejection part that ejects an airflow is formed, and a blower fan 206 that is used as an airflow generation part that generates an airflow supplied into the container 202. A duct 208 that connects the container 202 and the blower fan 206 is provided. The separation device 200 sends the air taken in from the blower fan 206 to the container 202 through the duct 208 and supplies the air to the sheets stacked on the stacking device 100 from the blowout port 204 as an air flow. Separate the paper loaded on the printer.

  The blower fan 206 is connected to the control device 800, and the amount of air per unit time supplied toward the sheet is controlled by the control device 800.

FIG. 4 shows a conveyance state detection device 500.
The conveyance state detection device 500 includes the roller 502 and the first rotary encoder 504 as described above, and also includes the swing member 506 and a pressing member 508 made of an elastic body such as a coil spring.
The swing member 506 can be rotated about the support shaft 46 with respect to the image forming apparatus main body 12 and is supported by using the support shaft 46 so as to be able to swing. A roller 502 is supported in the vicinity of the upstream end portion of the swing member 506 in the paper conveyance direction so as to be able to rotate using a rotation shaft 512. In addition, one end side of the pressing member 508 is mounted near the end of the swing member 506 on the downstream side in the paper conveyance direction. The other end side of the pressing member 508 is attached to the image forming apparatus main body 12.

  Further, the rotation shaft 512 of the roller 502 is arranged in the upstream region u instead of the downstream region d of the support shaft 46 in the paper transport direction.

  In the conveyance state detection device 500, the end of the swing member 506 on the downstream side in the sheet conveyance direction is biased so as to be pulled upward by the pressing member 508. Then, by being biased, the roller 502 is pressed against the paper P <b> 1 such that the swinging member 506 rotates about the support shaft 46. The strength of the pressing member 508 can be raised and lowered following the raising and lowering of the paper P1 while the roller 502 is kept in contact with the paper P1 when the paper P1 is raised and lowered by the airflow supplied from the separation device 200. It is prescribed as follows.

FIG. 5 shows a first modification of the transport state detection device 500.
The conveyance state detection apparatus 500 according to the above-described embodiment includes the pressing member 508, and the roller 502 is pressed against the paper P1 by the pressing member 508. On the other hand, the conveyance state detection apparatus 500 according to the first modification does not have the pressing member 508, and the roller 502 is pressed against the paper P1 by the gravity acting on the roller 502 and the like.

  Also in the first modified example, the rotating shaft 512 of the roller 502 is not located in the downstream area d of the support shaft 46 but in the upstream area u in the paper transport direction. . The same parts as those in the above-described embodiment with the conveyance state detection apparatus 500 are denoted by the same reference numerals in FIG.

FIG. 6 shows a second modification of the transport state detection device 500.
The conveyance state detection device 500 according to the second modification has a regulating member 516 that the conveyance state detection device 500 according to the above-described embodiment does not have.
The regulating member 516 is attached in the vicinity of the support shaft 46 of the image forming apparatus main body 12 and has a function of regulating the swinging of the swinging member 506 within a certain range. That is, as shown in FIG. 6B, the sheet P1 is raised by the supply of the airflow from the separating device 200, and the roller 502 is raised following the rise of the sheet P1, so that the swing member 506 is shown in FIG. Even if the rocking member 506 is rocked so as to rotate clockwise in FIG. 6B, the rocking member 506 comes into contact with the regulating member 516, and the rocking of the rocking member 506 is restricted. Then, the swing of the swing member 506 is restricted, so that the rise of the roller 502 is restricted. The rise of the roller 502 is restricted, and the rise of the paper P1 is restricted. As described above, in the transport state detection device 500 according to the second modification, the roller 502 regulates the rising of the paper due to the airflow supplied from the separation device 200.

FIG. 7 shows a control device 800.
The control device 800 includes a control circuit 802 made up of, for example, a CPU. Image data is input to the control circuit 802 via the communication interface 804, output from the first rotary encoder 504, and operation panel 850. And the output from the detection sensor 550 are input. Further, the image forming unit 14, the motor M 1, the motor M 2, and the blower fan 206 are controlled by the output from the control circuit 802.

FIG. 8 shows a control flow by the control device 800.
As shown in FIG. 8, for example, when a series of control starts when image data is input to the control circuit 802 via the communication interface 804, the control device 800 causes the sheet by the feed roll 302 to be printed in step S <b> 102. In accordance with at least one of the sheet feeding speed and the sheet feeding interval of the feeding roll 302, an initial setting of the load with which the pressing device 400 presses the feeding roll 302 against the sheet is performed. Then, the motor M1 is driven so that the feed roll 302 is pressed against the paper P1 with a set load.

  In the next step S104, the control device 800 starts driving the blower fan 206 of the separation device 200 and starts supplying airflow to the stacked paper.

  In the next step S106, the control device 800 starts driving the motor M2, starts rotating the feed roll 302, and starts feeding the paper.

  In the next step S108, the control device 800 causes the first rotary encoder 504 to measure the amount of paper movement.

  In the next step S120, the control device 800 compares the sheet movement amount measured in step S108 with a predetermined reference value. If the amount of movement of the paper measured in step S108 is the same as the predetermined reference value, the load is maintained while maintaining the load without changing the load that presses the feeding roll 302 against the paper. The process proceeds to S202. If the amount of paper movement measured in step S108 is larger than a predetermined reference value, the process proceeds to step S122, and the amount of paper movement measured in step S108 is smaller than a predetermined reference value. In this case, the process proceeds to step S126.

  In step S122, it is determined whether or not the load that presses the feed roll 302 against the paper at that time has reached a predetermined lower limit value of the load, and the load has reached the lower limit value. Advances to step S202 while maintaining the load without changing the load that presses the feed roll 302 against the paper. On the other hand, if the load that presses the feed roll 302 against the sheet at that time does not reach the lower limit value, the process proceeds to step S124.

  In step S124, the control device 800 drives the motor M1 of the pressing device 400 to reduce the load that presses the feeding roll 302 against the paper. If the load that presses the feeding roll 302 against the paper is weakened, the paper is less likely to be damaged. Further, since it is determined in step S122 that the load has not reached the lower limit value, even if the load is weakened, it is difficult to cause a problem that a paper feed failure by the feed roll 302 occurs.

  In step S126, it is determined whether or not the load pressing the feeding roll 302 against the sheet at that time has reached a predetermined upper limit value of the load, and the load has reached the upper limit value. Advances to step S202 while maintaining the load without changing the load that presses the feed roll 302 against the paper. On the other hand, if the load that presses the feeding roll 302 against the paper at that time does not reach the upper limit, the process proceeds to step S128.

  In step S128, the control device 800 drives the motor M1 of the pressing device 400 to increase the load that presses the feeding roll 302 against the paper. If the load for pressing the delivery roll 302 against the paper is increased, the amount of movement of the paper when the delivery roll 302 sends out the paper increases. In addition, since it is determined in step S126 that the load has not reached the upper limit value, even if the load is increased, the sheet is hardly damaged by the feed roll 302.

  In step S202, it is determined whether or not the leading edge of the sheet is detected by the detection sensor 550, and the process returns to step S108 until it is determined that the leading edge of the sheet is detected. On the other hand, if it is determined in step S202 that the leading edge of the sheet has been detected, the process proceeds to step S204.

  In step S204, the control device 800 drives the motor M1 to separate the delivery roll 302 from the paper, thereby turning off the load from the delivery roll 302 on the paper.

  In the above description, the control flow when the control device 800 controls the load that presses the feed roll 302 onto the paper has been described. However, the control device 800 also controls the blower fan 206. That is, the control device 800 is also used as a control unit that controls the airflow supplied from the separation device 200. For example, the control device 800 sets at least one of the paper type and the paper size input from the operation panel 850. In response, for example, the amount of airflow supplied to the paper is controlled.

FIG. 9 shows a conveyance state detection device 500 included in the image forming apparatus according to the second embodiment of the present invention.
The conveyance state detection apparatus 500 according to the first embodiment described above includes a roller 502 and a first rotary encoder 504 that is connected to the roller 502 and is used to measure the amount of movement of the sheet from the rotation amount of the roller 502. Had. In addition, the transport state detection apparatus 500 according to the second embodiment is used as a contact surface movement amount measurement unit that measures the movement amount of the peripheral surface 302a, which is a surface of the delivery roll 302 that is in contact with the paper P1. A second rotary encoder 530 is included.

FIG. 10 shows a control device 800 included in the image forming apparatus according to the second embodiment of the present invention.
In the control device 800 of the first embodiment described above, the output from the first rotary encoder 504, the output from the operation panel 850, and the output from the detection sensor 550 are input to the control circuit 802. In contrast, in the control device 800 included in the image forming apparatus 10 according to the second embodiment, the output from the second rotary encoder 530 is input to the control circuit 802. Similarly to the control device 800 included in the image forming apparatus 10 according to the first embodiment, the image forming unit 14, the motor M <b> 1, the motor M <b> 2, and the blower fan 206 are controlled by the output from the control circuit 802.

FIG. 11 shows a control flow by the control device 800 included in the image forming apparatus 10 according to the second embodiment of the present invention.
In the first embodiment described above, in step S108, the control device 800 causes the first rotary encoder 504 to measure the amount of movement of the paper, and in the next step S120, the amount of movement of the paper measured in step S108. A predetermined reference value was compared, and the load for pressing the feed roll 302 against the paper was controlled according to the comparison result.
On the other hand, in the second embodiment, the control device 800 causes the first rotary encoder 504 to measure the amount of paper movement in step S108, and then in step S110, sends it to the second rotary encoder 530. The amount of movement of the peripheral surface 302a of 302 is measured, and in the next step S140, the measured amount of movement of the paper is compared with the measured amount of movement of the peripheral surface 302a. The load that presses the feed roll 302 is controlled.

  That is, in step S140, control device 800 compares the amount of movement of the sheet measured in step S108 with the amount of movement of peripheral surface 302a measured in step S110. If the difference between the measured values is equal to a certain reference value, the process proceeds to step S202 while maintaining the load without changing the load that presses the feed roll 302 against the paper. If the difference between the two measurement values is smaller than a certain reference value, the process proceeds to step S142. If the difference between both measurement values is larger than the certain reference value, the process proceeds to step S146.

  In step S142, it is determined whether or not the load pressing the feeding roll 302 against the sheet at that time has reached a predetermined lower limit value of the load, and the load has reached the lower limit value. Advances to step S202 while maintaining the load without changing the load that presses the feed roll 302 against the paper. On the other hand, if the load that presses the feed roll 302 against the paper at that time does not reach the lower limit value, the process proceeds to step S144.

  In step S <b> 144, the control device 800 drives the motor M <b> 1 of the pressing device 400 to reduce the load that presses the feeding roll 302 against the paper. If the load that presses the feeding roll 302 against the paper is weakened, the paper is less likely to be damaged. In addition, since it is determined in step S142 that the load has not reached the lower limit value, even if the load is weakened, for example, a slip is generated between the feed roll 302 and the paper, so that the feed is performed. It is also difficult to cause a problem that a paper feed failure by the roll 302 occurs.

  In step S146, it is determined whether or not the load that presses the feed roll 302 against the sheet at that time has reached a predetermined upper limit value of the load, and the load has reached the upper limit value. Advances to step S202 while maintaining the load without changing the load that presses the feed roll 302 against the paper. On the other hand, if the load that presses the feed roll 302 against the paper at that time does not reach the upper limit, the process proceeds to step S148.

  In step S <b> 148, the control device 800 drives the motor M <b> 1 of the pressing device 400 to increase the load that presses the feeding roll 302 against the paper. If the load that presses the feeding roll 302 against the paper is increased, slippage is unlikely to occur between the feeding roll 302 and the paper, and the amount of movement of the paper when the paper is fed by the feeding roll 302 is increased. Further, since it is determined in step S146 that the load has not reached the upper limit value, even if the load is increased, the sheet is hardly damaged by the feed roll 302.

  Since the control other than that described above is the same as that of the first embodiment described above, the same numbers (numbers indicating steps) are given in FIG.

FIG. 12 shows a peripheral configuration of the feeding device 300 and the pressing device 400 of the image forming apparatus 10 according to the third embodiment of the present invention.
The image forming apparatus 10 according to the above-described first embodiment and the image forming apparatus 10 according to the above-described second embodiment have the conveyance state detection device 500 that detects the conveyance state of the paper. In contrast, the image forming apparatus 10 according to the third embodiment includes a floating state detection device 600 instead of the conveyance state detection device 500.

  The levitation state detection device 600 is used as a levitation state detection unit that detects the levitation state of the paper by the airflow supplied by the separation device 200, and includes a laser displacement meter 602. The laser displacement meter 602 is disposed above the paper P1, which is the uppermost paper stacked on the stacking device 100, and is used for detecting the height of the paper P1 from the paper stacking direction. In addition, about the same part as 1st Embodiment, the same number is attached | subjected in FIG. 12, and description is abbreviate | omitted.

  FIG. 13 shows a control device 800 included in the image forming apparatus 10 according to the third exemplary embodiment of the present invention. In the first embodiment described above, the output from the first rotary encoder 504, the output from the operation panel 850, and the output from the detection sensor 550 are input to the control circuit 802. On the other hand, in the third embodiment, an output from the laser displacement meter 602 is input to the control circuit 802 instead of the output from the first rotary encoder 504. Similarly to the first embodiment, the output from the operation panel 850 and the output from the detection sensor 550 are input to the control circuit 802, and the image forming unit 14 and the motor M <b> 1 are output by the output from the control circuit 802. The motor M2 and the blower fan 206 are controlled.

FIG. 14 shows a control flow by the control device 800 included in the image forming apparatus 10 according to the third embodiment of the present invention.
In the first embodiment described above, in step S108, the control device 800 causes the first rotary encoder 504 to measure the amount of movement of the paper, and in the next step S120, the amount of movement of the paper measured in step S108. A predetermined reference value was compared, and the load for pressing the feed roll 302 against the paper was controlled according to the comparison result.
On the other hand, in the third embodiment, in step S158, the control device 800 causes the laser displacement meter 602 to detect the floating state (height and floating amount) of the paper, and in the next step S160, the measurement is performed. A comparison is made between the levitation amount and a predetermined levitation amount, and the load for pressing the feed roll 302 against the paper is controlled according to the comparison result.

  That is, in step S160, the control device 800 compares the sheet floating amount measured in step S158 with a predetermined reference value. If there is no difference between the measured levitation amount and the reference value, the process proceeds to step S202 while maintaining the load without changing the load that presses the feed roll 302 against the paper. If the measured levitation amount is larger than the reference value, the process proceeds to S162. If the measured levitation amount is smaller than the reference value, the process proceeds to step S166.

  In step S162, it is determined whether or not the load pressing the feeding roll 302 against the sheet at that time has reached a predetermined lower limit value of the load, and the load has reached the lower limit value. Advances to step S202 while maintaining the load without changing the load that presses the feed roll 302 against the paper. On the other hand, if the load that presses the feed roll 302 against the paper at that time does not reach the lower limit value, the process proceeds to step S164.

  In step S164, the control device 800 drives the motor M1 of the pressing device 400 to reduce the load that presses the feeding roll 302 against the paper. If the load that presses the feed roll 302 against the paper is reduced, the paper is less likely to be damaged. Further, it is determined in step S162 that the load has not reached the lower limit value, and the sheet is floated higher than the reference value, so that it is expected that the uppermost sheet P1 is well separated. Even when the load is weakened, it is difficult to cause a problem that a paper feed failure by the feed roll 302 occurs.

  In step S166, it is determined whether or not the load pressing the feed roll 302 against the sheet at that time has reached a predetermined upper limit value of the load, and the load has reached the upper limit value. Advances to step S202 while maintaining the load without changing the load that presses the feed roll 302 against the paper. On the other hand, if the load that presses the feed roll 302 against the paper at that time does not reach the upper limit, the process proceeds to step S168.

  In step S168, the control device 800 drives the motor M1 of the pressing device 400 to increase the load that presses the feeding roll 302 against the paper. If the load that presses the feeding roll 302 against the paper is increased, the height of the paper floating is below the reference value, and the paper is good even when the uppermost paper P1 is not sufficiently separated. It becomes easy to be sent out. Further, since it is determined in step S166 that the load has not reached the upper limit value, even if the load is increased, the sheet is hardly damaged by the feed roll 302.

  Controls other than those described above are the same as those in the first embodiment described above, and therefore the same numbers (numbers indicating steps) are given in FIG.

FIG. 15 shows a modified example of the floating state detection device 600.
The floating state detection apparatus 600 according to the modification includes a camera 610 that is used as an imaging apparatus that captures sheets stacked from a direction having a component perpendicular to the sheet stacking direction. The camera 610 includes an image data processing apparatus 612. And the output from the camera 610 is input to the control device 800 via the image data processing device 612. According to the floating state detection apparatus 600 according to this modification, it is possible to detect not only the floating state of the sheet P1 positioned at the top, but also the floating state of other sheets.

  As described above, the present invention can be applied to an image forming apparatus such as a copying machine, a facsimile machine, and a copier, and a paper feeding apparatus used in these image forming apparatuses, for example.

1 is a right side view illustrating an image forming apparatus according to a first embodiment of the present invention. 2A and 2B are diagrams illustrating a separation device, a feeding device, a pressing device, and a conveyance state detection device included in the image forming apparatus according to the first embodiment of the present invention. FIG. 2A is a right side view of FIG. b) is a plan view. 1 is a perspective view illustrating a separation device included in an image forming apparatus according to a first embodiment of the present invention. 1 is a right side view illustrating a conveyance state detection device included in an image forming apparatus according to a first embodiment of the present invention. FIG. 10 is a right side view illustrating a first modification of the conveyance state detection device included in the image forming apparatus according to the first exemplary embodiment of the present invention. FIG. 6A is a right side view illustrating a second modification of the conveyance state detection device included in the image forming apparatus according to the first exemplary embodiment of the present invention, and FIG. FIG. 6B is a right side view showing a state where the uppermost sheet is levitated. 1 is a block diagram illustrating a control device included in an image forming apparatus according to a first embodiment of the present invention. 3 is a flowchart illustrating control by a control device included in the image forming apparatus according to the first exemplary embodiment of the present invention. FIGS. 9A and 9B are diagrams illustrating a conveyance state detection device included in an image forming apparatus according to a second embodiment of the present invention, FIG. 9A is a right side view, and FIG. 9B is a plan view. FIG. 5 is a block diagram illustrating a control device included in an image forming apparatus according to a second embodiment of the present invention. 6 is a flowchart illustrating control by a control device included in an image forming apparatus according to a second exemplary embodiment of the present invention. FIGS. 12A and 12B are diagrams illustrating a floating state detection device included in an image forming apparatus according to a third embodiment of the present invention, FIG. 12A is a right side view, and FIG. 12B is a plan view. It is a block diagram which shows the control apparatus which the image forming apparatus which concerns on the 3rd Embodiment of this invention has. 10 is a flowchart illustrating control by a control device included in an image forming apparatus according to a third exemplary embodiment of the present invention. It is a perspective view which shows the modification of the levitation state detection apparatus which the image forming apparatus which concerns on the 3rd Embodiment of this invention has.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 14 Image forming part 100 Stacking apparatus 200 Separating apparatus 300 Sending apparatus 302 Sending roll 302a Circumferential surface 400 Pressing apparatus 500 Conveyance state detecting apparatus 502 Roller 504 First rotary encoder 506 Swing member 516 Restricting member 530 Second rotary encoder 600 Levitation state detection device 610 Camera 800 Control device

Claims (14)

A loading section on which paper is loaded;
A separation device that supplies an air current and separates the sheets stacked on the stacking unit;
A delivery member that feeds the paper separated by the separation device toward the downstream side in the conveyance direction;
Pressing means for pressing the delivery member against the paper;
A conveyance state detecting means for detecting a conveyance state of the sheet fed by the feeding member;
Load control means for controlling the pressing force of the pressing means to the delivery member based on the detection result by the transport state detecting means;
A paper feeder. The conveyance state detection means includes
A rotating member that contacts the paper and rotates along with the conveyance of the paper;
A paper movement amount measuring unit that measures the movement amount of the paper from the rotation amount of the rotating member;
Have
The sheet feeding device according to claim 1, wherein the load control unit controls a pressing force of the pressing unit to the feeding member based on a sheet moving amount measured by the sheet moving amount measuring unit. The detection means includes
A rotating member that contacts and rotates with the paper;
A paper movement amount measuring unit that measures the movement amount of the paper from the rotation amount of the rotating member;
A contact surface movement amount measuring unit that measures a movement amount of a contact surface that contacts the paper of the delivery member;
Have
The control means is based on a difference between the movement amount of the contact surface measured by the contact surface movement amount measurement unit and the movement amount of the paper measured by the paper movement amount measurement unit. The sheet feeding device according to claim 1, wherein the pressing force to the feeding member is controlled.   The sheet feeding device according to claim 2 or 3, wherein the rotating member moves up and down following a sheet that moves up and down by an air flow supplied from a separation device. The rotating member is rotatably supported, and further includes a swinging member that is swingably supported by a support shaft.
The sheet feeding device according to claim 4, wherein the rotation shaft of the rotation member is disposed upstream of the support shaft in the sheet conveyance direction.   The sheet feeding device according to claim 4, wherein the rotating member regulates a rise of the sheet due to an airflow supplied from the separation device. A loading section on which paper is loaded;
A separation device that supplies an air current and separates the sheets stacked on the stacking unit;
A delivery member that feeds the paper separated by the separation device toward the downstream side in the conveyance direction;
Pressing means for pressing the delivery member against the paper;
A levitation state detection means for detecting a levitation state of the paper by the airflow supplied by the separation means;
Load control means for controlling the pressing force of the pressing means to the delivery member based on the detection result by the floating state detecting means;
A paper feeder.   The sheet feeding device according to claim 7, wherein the load control unit controls a pressing force of the pressing unit to the feeding member based on a height of the floated sheet detected by the floating state detection unit.   The load control means is included in the floating state detection means, and is applied to the feeding member of the pressing means based on an image photographed by photographing means for photographing sheets stacked in a direction perpendicular to the sheet stacking direction. The sheet feeding device according to claim 7 or 8, which controls a pressing force of the sheet.   And a setting unit configured to set an initial value of a pressing force of the pressing unit to the feeding member in accordance with at least one of a sheet feeding speed by the feeding member and a sheet feeding interval by the feeding member. Item 10. A sheet feeding device according to any one of Items 1 to 9.   The paper feeding device according to any one of claims 1 to 10, further comprising an air flow control means for controlling an air flow supplied from the dispensing device.   The paper feeding device according to claim 11, wherein the airflow control unit controls the airflow according to at least one of a paper type and a paper size. A loading section on which paper is loaded;
A separation device that supplies an air current and separates the sheets stacked on the stacking unit;
A delivery member that feeds the paper separated by the separation device toward the downstream side in the conveyance direction;
An image forming unit that forms an image on the sheet fed by the feeding member;
Pressing means for pressing the delivery member against the paper;
A conveyance state detecting means for detecting a conveyance state of the sheet fed by the feeding member;
Load control means for controlling the pressing force of the pressing means to the delivery member based on the detection result by the transport state detecting means;
An image forming apparatus. A loading section on which paper is loaded;
A separation device that supplies an air current and separates the sheets stacked on the stacking unit;
A delivery member that feeds the paper separated by the separation device toward the downstream side in the conveyance direction;
An image forming unit that forms an image on the sheet fed by the feeding member;
Pressing means for pressing the delivery member against the paper;
A levitation state detection means for detecting a levitation state of the paper by the airflow supplied by the separation means;
Load control means for controlling the pressing force of the pressing means to the delivery member based on the detection result by the floating state detecting means;
An image forming apparatus.

Images