JP6287415B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  For example, Patent Document 1 includes a plastic peeling claw for an organic photoconductor drum, a contact surface that contacts the photoconductor drum, and a tangent line of the photoconductor drum at a position where the tip of the peeling claw contacts the photoconductor drum. An image forming apparatus is disclosed in which the angle a formed by the sheet and the angle b formed by the guide surface that guides the separation when the sheet abuts against the tangent line satisfy the specific formula.

Japanese Patent Laid-Open No. 03-245173

  An object of the present invention is to suppress deterioration of a photoreceptor due to contact with a peeling claw.

An image forming apparatus according to claim 1 is provided.
A photoreceptor on which an electrostatic latent image is formed by rotating around and exposing the surface;
An exposure device that exposes the surface of the photoreceptor to form a latent image;
A developing device for developing a latent image formed on the surface of the photoconductor to form a developed image;
A transfer device for transferring the developed image to a recording medium at a transfer position after the developed image is formed on the surface of the photoreceptor;
A transporter for transporting the recording medium in a path passing through the transfer location from below to above in the direction of gravity;
A peeling member for separating the recording medium from the photosensitive member by contacting the front surface of the photosensitive member above the transfer portion, the peeling member being rotatably held by a fulcrum located above the leading end. Members ,
When the peeling member is held at the fulcrum and the fulcrum is movable between the first position and the second position, and the fulcrum exists at the second position, the first position Than the case where the fulcrum is present, the tip of the peeling member is arranged on the downstream side in the circumferential direction of the photosensitive member, and the direction of the line connecting the center of gravity of the peeling member and the tip is at the first position. and the fulcrum member close to the direction of the vertical line than when the person when the fulcrum there is the fulcrum is in its second position,
It is provided with.

An image forming apparatus according to claim 2
The fulcrum holding member holds the fulcrum of the peeling member with a groove that descends from the second position to the first position.

An image forming apparatus according to a third aspect further includes the image forming apparatus according to the first aspect.
An urging member for urging the fulcrum of the peeling member held by the fulcrum holding member from the second position toward the first position is provided.

According to a fourth aspect of the present invention, there is provided an image forming apparatus according to any one of the first to third aspects.
Comprising a guide member for guiding by separating the recording medium that has been peeled off by the peeling member from the peeling member, the exfoliated recording medium by being guided along the said guide member,該剥release member the first It is characterized by moving from a position to the second position .

  According to the image forming apparatus of the first aspect, it is possible to suppress deterioration of the photoreceptor due to the contact with the peeling claw, compared to the case where the present configuration is not provided.

  According to the image forming apparatus of the second aspect, the structure can be simplified as compared with the case where the present configuration is not provided.

  According to the image forming apparatus of the third aspect, the fulcrum moves more reliably as compared with the case where the urging member is not provided.

  According to the image forming apparatus of the fourth aspect, it is possible to suppress scratches on the photosensitive member as compared with the case where the present configuration is not provided.

1 is a schematic configuration diagram of a printer as a first embodiment of an image forming apparatus of the present invention. It is a figure which shows the periphery structure of a peeling nail | claw. It is a figure which shows the state which the front-end | tip of a peeling nail is contacting the surface of a photoreceptor. It is a figure which shows the periphery structure of the peeling nail | claw in 2nd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a printer as a first embodiment of an image forming apparatus of the present invention.

  The printer 10 shown in FIG. 1 is a monochrome printer, and the printer 10 incorporates an embodiment of a sheet peeling mechanism from the photosensitive member of the present invention.

  An image signal representing an image created outside the printer 10 is input to the printer 10 via a signal cable (not shown). The printer 10 includes a control unit 11 that controls the movement of each component in the printer 10, and an image signal is input to the control unit 11. In the printer 10, an image is formed based on the image signal under the control of the control unit 11.

  Two paper trays 21 are accommodated in the lower part of the printer 10. In these sheet trays 21, sheets P having different dimensions are stored in a stacked state for each sheet tray 21. Each paper tray 21 is configured to be freely drawn out for replenishing paper P. The paper P corresponds to an example of a recording medium according to the present invention. As the recording medium referred to in the present invention, an OHP sheet, plastic paper, or the like may be employed.

  Of these two paper trays 21, the paper P having a size that matches the size of the image represented by the image signal input to the control unit 11 is sent out from the paper tray by the pickup roll 22. The fed sheets P are separated one by one by the separating roll 23, the separated sheet P is conveyed upward, and the leading end of the sheet P reaches the standby roll 24. The standby roll 24 plays a role of feeding out the paper P by adjusting the subsequent transport timing. The paper P that has reached the standby roll 24 is transported further upward by the standby roll 24 with the subsequent transport timing adjusted.

  The printer 10 includes a photoreceptor 12 that rotates in a direction indicated by an arrow A above a standby roll 24. A charger 13, an exposure device 14, a developing device 15, a transfer device 16, and a photoconductor cleaner 17 are disposed around the photoconductor 12.

  The photoconductor 12 has a cylindrical shape and extends in the depth direction of FIG. 1. The photoconductor 12 holds a charge by charging the surface and releases the charge by exposure to form an electrostatic latent image on the surface. The photoreceptor 12 corresponds to an example of the photoreceptor in the present invention. Note that a rotating photoreceptor belt or the like may be employed as the photoreceptor in the present invention.

  The charger 13 includes a charging roll that rotates in contact with the surface of the photoreceptor 12, and charges the surface of the photoreceptor 12 by applying a charge to the surface of the photoreceptor 12 with the charging roll. As the charger 13, in addition to a charger using a charging roll, a corona discharger that is not in contact with the photosensitive member may be employed.

  The exposure device 14 includes a light emitter that emits laser light (exposure light) modulated in accordance with an image signal supplied from the control unit 11, and a rotary polygon mirror that scans the photoconductor 12 with the laser light. The exposure light is output from the exposure unit 14. The photoreceptor 12 is exposed to the exposure light, and an electrostatic latent image is formed on the surface of the photoreceptor 12. The exposure device 14 corresponds to an example of the exposure device according to the present invention. In addition to the system using laser light, an LED array in which a large number of LEDs are arranged along the scanning direction can be adopted as the exposure device in the present invention.

  The electrostatic latent image formed on the surface of the photosensitive member 12 exposed to the exposure light is developed by the developing unit 15. The developing unit 15 includes a developing roll 15c, and a toner storage unit 15a is connected to the developing unit 15 via a toner supply path 15b. A developer containing toner and a magnetic carrier is stored in the developing device 15, and the toner stored in the toner storage portion 15a is appropriately supplied to the developing device 15 through the toner supply path 15b. . The magnetic carrier is obtained, for example, by applying a resin coating to the surface of iron powder. The toner particles are formed using, for example, a binder resin, a colorant, and a release agent. The developing device 15 charges the toner and the magnetic carrier by stirring the developer in which the magnetic carrier particles and the toner particles are mixed. The developer in the developing device 15 is supplied to the surface of the photoconductor 12 by the developing roll 15c, and the latent image on the surface of the photoconductor 12 is developed by the charged toner in the developer to form a toner image (that is, a developed image). . The developing device 15 corresponds to an example of a developing device referred to in the present invention. In addition, as the developing device referred to in the present invention, a one-component type developing device not including a magnetic carrier may be employed.

  Here, the standby roll 24 sends the paper P upward so that the paper P reaches the transfer location in accordance with the timing when the toner image on the photoconductor 12 reaches the transfer location facing the transfer device 16. . The toner image on the photoconductor 12 is transferred to the fed paper P under the action of the transfer device 16. The transfer device 16 corresponds to an example of a transfer device according to the present invention, and the standby roll 24 corresponds to an example of a transport device according to the present invention.

  The toner remaining on the photoconductor 12 after the transfer of the toner image is removed from the photoconductor 12 by the photoconductor cleaner 17.

The paper P that has received the transfer of the toner image further proceeds in the direction of arrow B, and the toner image is fixed on the paper P by being heated and pressurized by the fixing device 25. As a result, an image composed of a fixed toner image is formed on the paper P.

  The paper P that has passed through the fixing device 25 proceeds in the direction of arrow C toward the discharge device 26, and is further sent in the direction of arrow D by the discharge device 26 to be discharged onto the paper discharge tray 18.

  Incidentally, the paper P that has received the transfer of the toner image by the transfer device 16 may be wound around the photoconductor 12. If such winding of the paper P is left unattended, it may cause a paper jam or damage to the photoconductor cleaner 17. Therefore, the printer 10 of this embodiment is provided with a peeling claw for peeling the paper P from the photoconductor 12. ing.

  FIG. 2 is a view showing a peripheral structure of the peeling claw.

  Around the photosensitive member 12, a charging roll 13a of the charger 13 described above, a developing roll 15c of the developer 15 described above, a transfer device 16, and a cleaning blade 17a of the photosensitive member cleaner 17 described above are provided. A separation claw 30 is disposed above the transfer device 16 and the cleaning blade 17a above the position 12. The peeling claw 30 has a tip 31 in contact with the surface of the photoconductor 12 and is rotatable around a fulcrum 32. In this embodiment, the fulcrum 32 is a round bar extending in a direction perpendicular to the paper surface of FIG. 2, and the fulcrum 32 is held by the peeling claw holder 40 by passing through the long hole 41 of the peeling claw holder 40. The peeling claw holder 40 corresponds to an example of a fulcrum holding member according to the present invention. Further, since the fulcrum 32 is movable in the long hole 41 and the long hole 41 is inclined to the right side in FIG. 2, the peeling claw is normally used when the paper P is not wound around the photosensitive member 12. Naturally, it is located on the lower end side of the long hole 41 as shown by a dotted line in FIG. The long hole 41 corresponds to an example of a groove according to the present invention, and the position on the lower end side corresponds to an example of a first position according to the present invention.

  When the paper P is wound around the photosensitive member 12, the leading edge of the paper P hits the peeling claw 30 and is pushed by the paper P, and the peeling claw 30 moves upward as shown by a solid line in FIG. At this time, the fulcrum 32 of the peeling claw 30 is located on the upper end side of the long hole 41. The position on the upper end side corresponds to an example of the second position in the present invention.

  The paper P that has pushed up the peeling claw 30 is peeled off from the surface of the photoreceptor 12 by the tip 31 of the peeling claw 30, and the front end of the paper P is lifted upward along the peeling claw 30. Then, the leading edge of the paper P reaches the guide surface 42 provided on the peeling claw holder 40 which is more robust than the peeling claw 30 and is separated from the peeling claw 30, and the paper P is further lifted upward along the guide surface 42. It is done. The guide surface 42 protrudes forward (that is, the right side in FIG. 2) from the peeling claw 30 when the peeling claw 30 is pushed up by the paper P. As a result, the guide surface 42 is closer to the photoconductor 12 than before the protruding. The sheet P is separated from the peeling claw 30 at the position. Thus, by receiving the force of the paper P by the guide surface 42 of the peeling claw holder 40 that is more robust than the peeling claw 30, the impact on the peeling claw 30 is reduced, and the scratches on the photoconductor 12 caused by the impact, The streaks that occur in the image due to the scratch are also suppressed. The peeling claw holder 40 having the guide surface 42 corresponds to an example of a guide member according to the present invention. After the paper P is separated from the peeling claw 30 and heads upward, it reaches the star wheel 43 attached to the peeling claw holder 40 and is pushed toward the fixing device 25 by being pushed by the star wheel 43. It will be followed.

  Comparing the posture of the peeling claw 30 at the normal time when the paper P is not wound and the posture of the peeling claw 30 at the time of movement moved upward by being pushed by the paper P with the winding, it is more normal than when moving. Time is more posture. More specifically, the line connecting the center of gravity 33 and the tip 31 of the peeling claw 30 is closer to the vertical in the normal state than in the moving state. Thus, when the peeling claw 30 stands normally, the pressing force of the tip 31 against the surface of the photoconductor 12 due to the weight of the peeling claw 30 is smaller than the posture at the time of movement. For this reason, deterioration of the photoconductor 12 caused by the tip 31 of the peeling claw 30 rubbing against the surface of the photoconductor 12 is suppressed, and generation of streaks on the image caused by such deterioration is also suppressed.

  Here, the contact state between the tip 31 of the peeling claw 30 and the surface of the photoreceptor 12 will be described.

  FIG. 3 is a view showing a state where the tip of the peeling claw is in contact with the surface of the photoreceptor.

  The tip 31 of the peeling claw 30 is chamfered in two steps in order to avoid damaging the surface of the photoconductor 12 with a sharp corner, and in a normal time indicated by a dotted line, the surface 35 located on the left side in FIG. It is in contact with the surface of the body 12. During the movement indicated by the solid line, the surface 34 located on the right side of FIG.

  Next, a second embodiment of the present invention will be described. Since the second embodiment is the same as the first embodiment except for the difference in the structure for holding the peeling claw 30, the following description will focus on the peeling claw holding structure, and a duplicate description will be omitted. To do.

  FIG. 4 is a view showing a peripheral structure of the peeling claw in the second embodiment.

  In the second embodiment, a long hole 45 is formed in the peeling claw holder 40 in a substantially horizontal direction, and the fulcrum 32 is held by the peeling claw holder 40 by the fulcrum 32 of the peeling claw 30 passing through the long hole 45. ing.

  Further, in the second embodiment, a spring 50 that biases the fulcrum 32 of the peeling claw 30 to the right side in FIG. 4 is provided, and this spring 50 corresponds to an example of a biasing member according to the present invention. . As the urging member, rubber or the like may be employed. When the spring 50 urges the fulcrum 32 of the peeling claw 30, the fulcrum 32 is positioned at one end of the elongated hole 45 in the right direction of FIG. Become. Then, the fulcrum 32 is positioned at one end of the elongated hole 45 in the right direction in FIG. 4, so that the posture of the peeling claw 30 is established as in the first embodiment, and the tip 31 on the surface of the photoreceptor 12 is placed. The pressing force is small.

  Also in the case of the second embodiment, when the paper P is wound, it is pushed by the leading end of the paper P and the peeling claw 30 is pushed up as shown by the solid line in FIG. Peel off.

  In the above description, a printer is shown as an embodiment of the image forming apparatus of the present invention. However, the image forming apparatus of the present invention may be applied to a facsimile, a copy, a multifunction peripheral, or the like.

  DESCRIPTION OF SYMBOLS 10 ... Printer, 11 ... Control part, 12 ... Photoconductor, 13 ... Charger, 14 ... Exposure device, 15 ... Developing device, 16 ... Transfer device, 25 ... Fixing device, 24 ... Standby roll, 30 ... peeling claw, 31 ... tip, 32 ... fulcrum, 40 ... peeling claw holder, 42 ... guide surface, 43 ... star wheel, 41, 45 ... long hole, 50 ... spring , P …… Paper

Claims (4)

A photoreceptor on which an electrostatic latent image is formed by rotating around and exposing the surface;
An exposure device that exposes the surface of the photoreceptor to form a latent image;
A developing device for developing a latent image formed on the surface of the photoreceptor to form a developed image;
A transfer unit that transfers the developed image to a recording medium at a transfer position after the developed image is formed on the surface of the photoreceptor;
A transporter for transporting the recording medium in a path passing through the transfer location from below to above in the direction of gravity;
A peeling member that peels off the recording medium from the photoconductor with the tip contacting the surface of the photoconductor above the transfer location, and is peeled off and held rotatably at a fulcrum located above the tip. Members ,
The peeling member is held at the fulcrum, and the first position and the tip of the peeling member are arranged on the downstream side in the circumferential direction of the photoconductor as compared with the case where the fulcrum exists at the first position . The fulcrum is freely movable between two positions, and the distance between the tip of the peeling member and the surface of the photosensitive member is closer when the fulcrum is at the second position, and the center of gravity of the peeling member the direction of the line connecting the tip, and the fulcrum member close to the direction of the vertical line than when the person when the fulcrum is in the position of the first is fulcrum is in the position of the second,
An image forming apparatus comprising: The image forming apparatus according to claim 1, wherein the fulcrum holding member holds the fulcrum of the peeling member with a groove descending from the second position to the first position. The image forming apparatus according to claim 1, further comprising an urging member that urges the fulcrum of the peeling member held by the fulcrum holding member from the second position toward the first position. . Comprising a guide member for guiding by separating the peeled recording medium from the peeling member by the separating member, that its exfoliated recording medium is guided along the said guide member, said fulcrum of該剥release member first The image forming apparatus according to claim 1, wherein the image forming apparatus is moved from the position 1 to the second position .

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