JP2011150167A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure the degree of freedom during installation of a device. <P>SOLUTION: This image forming apparatus 1 includes a photoreceptor drum 11 rotatably arranged and holding an image on the outer peripheral surface, a transfer drum 21 rotatably arranged facing the photoreceptor drum 11 and transferring the image held by the photoreceptor drum 11 to paper S sandwiched between it and the photoreceptor drum 11, a gripper 23 holding the paper S supplied toward the outer peripheral surface of the transfer drum 21, and a hand supply section 60 supplying the paper S toward different positions around the transfer drum 21. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  For example, in an image forming apparatus such as a copying machine or a printer that employs an electrophotographic system, a toner image formed on a photosensitive drum is transferred and fixed to a recording material supplied from a recording material supply unit, thereby obtaining an image. Is forming.

  As a prior art described in the publication, an image carrier (photosensitive drum) that carries and rotates a visible image, and a transfer material that carries a recording material supplied from a recording material supply unit and rotates together with the image carrier. There is an image forming apparatus including a carrier and a transfer unit that transfers a visible image formed on the image carrier onto a transfer material carried on the transfer material carrier (Japanese Patent Laid-Open No. 6-230687). ).

Japanese Patent Laid-Open No. 6-230687

  An object of this invention is to ensure the freedom degree at the time of installation of an apparatus.

  According to the first aspect of the present invention, an image holding body that is rotatably arranged and holds an image on an outer peripheral surface thereof, and is rotatably arranged to face the image holding body, and is sandwiched between the image holding body. A transfer member that transfers an image held on the image carrier to a recording material, a holding unit that holds the recording material supplied toward the outer peripheral surface of the transfer member, and the periphery of the transfer member, An image forming apparatus comprising: a supply unit that supplies the recording material toward different positions around the periphery.

A second aspect of the present invention is the image forming apparatus according to the first aspect, wherein the holding unit is a gripping member that grips the recording material with the transfer member interposed therebetween.
According to a third aspect of the present invention, the gripping member starts gripping the recording material to be supplied, depending on a position around the transfer member toward which the supply member supplies the recording material. The image forming apparatus according to claim 2, wherein the timing of the change is changed.

  According to a fourth aspect of the present invention, the image holding body sequentially holds images of different colors and sequentially transfers the held images of the respective colors to the recording material held by the transfer member by the holding member. The gripping member releases the grip of the recording material with respect to the transfer member after the image of the last color is transferred from the image carrier to the recording material gripped by the transfer member. The image forming apparatus according to claim 2.

  The invention according to claim 5 is characterized in that the supply means supplies the recording material along the rotation direction of the transfer member and the tangential direction of the outer peripheral surface of the transfer member at each of the surrounding positions. The image forming apparatus according to claim 1.

  According to a sixth aspect of the present invention, the supply means includes a plurality of supply paths that are provided around the transfer member and supply the recording material to the transfer member from different positions. 6. The image forming apparatus according to any one of items 1 to 5.

  The invention according to claim 7 is characterized in that the supply means is provided so as to be movable around the transfer member, and includes a single supply path for supplying the recording material to the transfer member from different positions. The image forming apparatus according to claim 1.

According to invention of Claim 1, the freedom degree at the time of installation of an apparatus is securable.
According to the second aspect of the present invention, it is possible to more reliably hold the newly supplied recording material to the image carrier as compared with the case where the present configuration is not provided.
According to the third aspect of the present invention, it is possible to reliably hold the newly supplied recording material to the image holding member as compared with the case where this configuration is not provided.
According to the fourth aspect of the present invention, compared to the case where the present configuration is not provided, for example, when a multicolor image is formed on a recording material, the positional deviation of each color image on the recording material can be suppressed. It becomes possible.
According to the fifth aspect of the present invention, it is possible to supply the recording material to the transfer member in a more stable state as compared with the case where this configuration is not provided.
According to the sixth aspect of the present invention, it is possible to change the position of the supply means according to the intended use as compared with the case where this configuration is not provided.
According to the seventh aspect of the present invention, the supply path of the apparatus can be finely adjusted as compared with the case where a plurality of supply paths are provided.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. FIG. 3 is a configuration diagram around a transfer drum and a manual feed portion according to the present embodiment. FIG. 10 is a configuration diagram around a transfer drum and a manual feed unit according to another embodiment.

Hereinafter, this embodiment will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus 1 to which the exemplary embodiment is applied.
The image forming apparatus 1 holds an image forming unit 10 on which a toner image is formed and a toner image formed by the image forming unit 10 on a sheet S that is an example of a recording material that holds and supplies the supplied sheet S. The transfer device 20 for transferring, the fixing device 30 for fixing the toner image on the paper S released from the transfer device 20, the paper supply unit 40 for supplying and transporting the paper S, and the control unit 100 for controlling the entire image forming apparatus 1. have. Each component of the image forming apparatus 1 is accommodated in the housing 2, and a paper discharge stacking unit 3 for stacking the sheets S discharged from the fixing device 30 is provided on the top of the housing 2. Yes.

First, the image forming unit 10 uses a photosensitive drum 11 as an example of an image carrier, a charging device 12 that charges the photosensitive drum 11, an exposure device 13 that exposes the charged photosensitive drum 11, and a developer. A rotary developing device 14 that performs development, and a cleaning device 15 that cleans the developer remaining on the photosensitive drum 11.
The photosensitive drum 11 includes a photosensitive layer (not shown) having a negative charging polarity on the surface thereof, and is attached so as to rotate in the arrow A direction. The charging device 12, the exposure device 13, the rotary developing device 14, and the cleaning device 15 are installed in this order along the arrow A direction around the photosensitive drum 11. Here, the outer diameter of the photosensitive drum 11 is, for example, 30 mm.

The charging device 12 is a contact roller type discharging device in the present embodiment, and is configured to charge the photosensitive drum 11 while rotating together with the photosensitive drum 11.
The exposure device 13 is configured to form an electrostatic latent image by irradiating the charged surface of the photosensitive drum 11, and includes a plurality of LEDs (not shown) arranged in the present embodiment.

The rotary developing unit 14 includes a rotating shaft 14A, and yellow (Y), magenta (M), cyan (C), and black (K) developing devices 14Y, 14M, 14C, and 14K installed around the rotating shaft 14A. It has. Further, the rotary developing device 14 is configured to rotate in the direction of arrow C around the rotation shaft 14A, and one of the developing devices stops at a position facing the photosensitive drum 11. The rotary developing device 14 is configured to develop the electrostatic latent image on the photosensitive drum 11 formed by the exposure device 13 using toner. The outer diameter of the rotary developing device 14 is, for example, 100 mm.
These developing units 14Y, 14M, 14C, and 14K contain two-component developers including corresponding color component toners and carriers. Here, although the two-component developer is used in the present embodiment, a one-component developer may be used. In the following description, the two-component developer is simply referred to as a developer.
The cleaning device 15 is configured to remove the developer remaining on the surface of the photosensitive drum 11 and deposits other than the developer. The cleaning device 15 of the present embodiment is a blade type cleaner.

  Next, the transfer device 20 will be described. The transfer device 20 is an example of a transfer member. The transfer device 20 is rotatably disposed to face the photoconductive drum 11. The transfer device 21 transfers the toner image on the photoconductive drum 11 to the paper S, and the paper on the transfer drum 21. A gripper 23 that grips S and a phase sensor 25 that detects the phase of the rotating transfer drum 21 are included.

The transfer drum 21 includes a drum-shaped base 21A and an elastic layer 21B formed on the outer peripheral surface of the base 21A. However, the elastic layer 21B does not cover a part of the outer peripheral surface of the base portion 21A along the axial direction of the base portion 21A, and this portion is an exposed portion 21C where the base portion 21A is exposed.
The transfer drum 21 is provided to rotate in the direction of arrow B in synchronization with the rotation of the photosensitive drum 11 in a state where the elastic layer 21B is elastically deformed to form a nip portion with the photosensitive drum 11. In the following description, a nip portion formed by the photosensitive drum 11 and the transfer drum 21 is referred to as a transfer portion T.
The base 21A in the present embodiment is a conductive hollow tube, and is specifically made of metal. In the present embodiment, it is made of aluminum having a diameter of 112 mm.
The elastic layer 21B is a semiconductive elastic member, and is specifically made of polyurethane having a thickness of 5 mm. The outer diameter when the elastic layer 21B is provided around the base 21A of the present embodiment is 122 mm.

  Here, the base 21A is configured such that a transfer bias composed of a voltage having a polarity opposite to that of the toner is applied from a high voltage power source (not shown). The toner constituting the toner image on the photosensitive drum 11 is transferred to the paper S on the elastic layer 21B at the transfer portion T.

  The gripper 23 as an example of a gripping member is attached to the exposed portion 21C of the transfer drum 21, and is configured to grip the end portion of the paper S between the elastic layer 21B. The gripper 23 in the present embodiment is made of a plate-like member, and one end (downstream in the direction of arrow B, which is the rotation direction of the transfer drum 21) is rotatably fixed to the exposed portion 21C, and the other (transfer drum) 21 is the free end. As a result, the gripper 23 can swing and can be opened and closed to hold the paper S. In the present embodiment, the gripper 23 is configured to grip an end of the paper S on the traveling direction side. The gripper 23 grips the end portion of the sheet S with the transfer drum 21. Further, the transfer drum 21 of the present embodiment does not perform so-called electrostatic attraction for holding the paper S, and the transfer drum 21 has a charger such as a corotron for electrostatic attraction of the paper S. Although not provided, the present invention is not limited to the above embodiment, and a method of performing electrostatic adsorption may be used as a holding unit.

Here, the maximum length of the sheet S that can be used in the image forming apparatus 1 according to the present embodiment is limited to the circumference of the elastic layer 21 </ b> B provided on the transfer drum 21 in the arrow B direction. The sheet S supplied to the transfer drum 21 is gripped by the gripper 23 so as not to straddle the exposed portion 21C.
The opening / closing timing of the gripper 23 can be controlled by the control unit 100.

  Further, the phase sensor 25 as an example of the phase detection unit is disposed to face the outer peripheral surface of the transfer drum 21 and rotates by detecting a mark (not shown) provided on the transfer drum 21. The phase of the transfer drum 21 is measured.

The gripper 23 in the present embodiment is a plate-like member, but may have other shapes such as a column or a thin line, and the mode of installing the gripper 23 on the exposed portion 21C is also limited to the present embodiment. It is not a thing.
Further, the gripper 23 in the present embodiment is configured to hold the end of the sheet S in the traveling direction on the transfer drum 21 as described above, but holds the end opposite to the traveling direction of the sheet S. The transfer drum 21 may further include a member that performs the above operation.

  The fixing device 30 includes a heating roll 31 having a heating source (not shown) and rotatably arranged, and a pressure roll 32 pressed against the heating roll 31.

  The paper supply unit 40 is provided below the image forming apparatus 1, specifically, below the transfer drum 21, a paper storage unit 41 that stores the paper S therein, and a take-out roll 42 that takes out the paper S from the paper storage unit 41. , A separating roll 43 that separates the closely contacted paper S and a transport roll 44 that transports the paper S are provided.

  Here, in the present embodiment, the fixing path 30 supplies the paper S after the toner image is transferred at the transfer portion T, and the supply path 51 for supplying the paper S from the paper storage portion 41 to the transfer portion T. And a discharge path 52 for discharging to the discharge stacking unit 3 via the. In this embodiment, the sheet S supplied to the transfer drum 21 rotates while being wound around the transfer drum 21 by the gripper 23, and this is referred to as a rotation path 53. In this embodiment, the sheet S is supplied from the sheet storage portion 41 toward the sheet feeding position Pa that is located on the upstream side in the rotation direction of the transfer drum 21 as viewed from the transfer portion T. Further, in the present embodiment, the sheet S is discharged toward the fixing device 30 from the discharge position Pb located on the downstream side in the rotation direction of the transfer drum 21 as viewed from the transfer portion T.

On the other hand, the image forming apparatus 1 according to the present embodiment is an example of a supply unit, and can form an image on the paper S supplied from the paper supply unit 40 built in the housing 2 and can be an example of a supply unit. In addition, an image can be formed on the paper S supplied from the manual supply unit 60 externally attached to the housing 2.
As shown in FIG. 1, the housing 2 of the image forming apparatus 1 is provided with a plurality of attachment portions 70 (three in this example) for attaching the manual feeding portion 60. In FIG. 1, the case where the manual feed supply unit 60 is attached to the lowermost mounting part 70 among the three attachment parts 70 is illustrated, but the manual feed supply part 60 is attached to the other mounting part 70. Alternatively, the manual feed supply unit 60 may be attached to two or all of the attachment units 70, respectively.

  The manual paper supply unit 60 includes a manual paper storage unit 61 that stores the paper S therein, a manual feed roll 62 that is an example of a discharge member that extracts the paper S from the manual paper storage unit 61, A manual feed drive source 63 that is an example of a take-out drive source that drives the take-out roll 62 is provided. Here, the manual feed drive source 63 is provided in the manual feed paper storage unit 61 and is connected to the manual feed roll 62 so as to drive the manual feed roll 62. That is, in the present embodiment, the manual sheet storage unit 61, the manual feed roll 62, and the manual feed drive source 63 are integrally configured. The manual feed portion 60 includes a terminal (not shown) connected to the manual feed drive source 63, and this terminal is connected to the housing when the manual feed portion 60 is attached to the attachment portion 70. By being connected to another terminal (not shown) provided inside 2, power supply and control thereof are performed.

In addition, each attachment portion 70 includes an opening for receiving the manual feed supply portion 60 and supports the manual feed portion 60 inserted into the opening, and the manual feed supply portion 60 is inserted. And a manual feed sensor 72 for detection.
In the present embodiment, the dimensions of the manual feed portion 60 and the attachment portion 70 are such that one manual feed portion 60 can be replaced and attached to each attachment portion 70 provided in the housing 2. Is set.

  FIG. 2 is a diagram for explaining the relationship between the transfer drum 21 and each mounting portion 70 in the image forming apparatus 1. 2 shows a state in which the manual supply unit 60 is attached to each of the three attachment parts 70, unlike FIG. In the configuration of the present embodiment, when the bottom area of the housing 2 is limited, a plurality of sizes (or types) of sheets S can be used without replacing the sheets in the sheet storage unit 41. , Can improve convenience.

In the image forming apparatus 1, a first manual feed path 54 and a second manual feed for supplying the paper S from the manual supply unit 60 attached to each mounting unit 70 toward the outer peripheral surface of the transfer drum 21. A paper feed path 55 and a third manual paper feed path 56 are provided.
Here, the first manual paper feed path 54 supplies the paper S toward the first manual paper feed position P1 located upstream of the transfer portion T and the paper feed position Pa in the rotation direction of the transfer drum 21. Configured as follows. Further, the second manual paper feed path 55 supplies the paper S toward the second manual paper feed position P2 located upstream of the first manual paper feed position P1 in the rotation direction of the transfer drum 21. Configured. Furthermore, the third manual feed path 56 is a third hand located downstream of the second manual feed supply position P2 in the rotation direction of the transfer drum 21 and upstream of the transfer portion T in the rotation direction of the transfer drum 21. The sheet S is configured to be supplied toward the difference sheet feeding position P3.

  As described above, in the present embodiment, the sheet S is supplied from the sheet supply unit 40 and the sheet S is supplied from the manual supply unit 60 attached to the attachment unit 70. The paper position is made different. In the present embodiment, the paper feed position with respect to the transfer drum 21 is made different depending on which of the plurality of attachment portions 70 is supplied with the paper S from the manual feed portion 60 attached to which attachment portion 70. It is like that.

  In the present embodiment, the first manual feed path 54, the second manual feed path 55, and the third manual feed path 56 for supplying the paper S from the manual feed section 60 attached to each mounting section 70. The exit side of the transfer drum 21 is tangential to the outer peripheral surface of the transfer drum 21 and is directed downstream in the rotation direction of the transfer drum 21 (arrow B direction). As a result, the sheet S supplied from the manual feed supply unit 60 attached to the attachment unit 70 is configured to be supplied from the tangential direction of the transfer drum 21.

Next, an image forming process in the image forming apparatus 1 will be described.
First, a color material reflected light image of a document read by a document reading device (not shown), color material image data formed by a personal computer (not shown), etc. are, for example, R (red), G (green). , B (blue) data is input to an image signal processing device (not shown) and subjected to predetermined image processing. The image data subjected to the image processing is converted into color material gradation data of four colors of yellow (Y), magenta (M), cyan (C), and black (K), and is output to the exposure device 13.

  As the image forming operation starts, the photosensitive drum 11 and the transfer drum 21 start to rotate in synchronization. Then, after the photosensitive layer of the rotating photosensitive drum 11 is charged by the charging device 12, an electrostatic latent image of the first color (for example, yellow) corresponding to the image information is formed by the exposure device 13. Further, as the transfer drum 21 starts to rotate, the phase sensor 25 measures the phase of the transfer drum 21. At this time, the gripper 23 provided on the transfer drum 21 is open.

On the other hand, in the rotary developing device 14, a developing device (for example, yellow developing device 14Y in the case of yellow) having a color component toner corresponding to the electrostatic latent image formed on the photosensitive drum 11 is used as the photosensitive drum 11. It has been rotated in advance so as to be placed at a position opposite to and stopped.
Then, for example, the electrostatic latent image on the photosensitive drum 11 is developed by the developing device 14 </ b> Y, and a toner image is formed on the photosensitive drum 11. The toner image (here, a yellow toner image) is sent toward a transfer portion T facing the transfer device 20 as the photosensitive drum 11 rotates.

  In response to the start of the image forming operation, the paper S is also supplied. Whether the control unit 100 supplies the sheet S from the sheet supply unit 40 or the sheet S from the manual supply unit 60 attached to the attachment unit 70 before starting the image forming operation. Accepting instructions about. Further, in the case where the manual feed supply unit 60 is attached to each of the plurality of attachment units 70, the control unit 100 determines which attachment unit 70 is attached to which manual supply unit 60 supplies the paper S. Accepting instructions.

For example, when the paper S is supplied from the paper supply unit 40, the paper S taken out from the paper storage unit 41 by the take-out roll 42 is sent to the supply path 51 through the separation roll 43 and using the transport roll 44. . At this time, the conveyance control of the paper S is performed based on the phase of the transfer drum 21 obtained by the phase sensor 25 so that the gripper 23 reaches the paper feed position Pa as the gripper 23 reaches the paper feed position Pa. Is called. Then, as the edge of the sheet S in the traveling direction reaches the sheet feeding position Pa, the gripper 23 shifts from an open state to a closed state. Accordingly, the end portion of the sheet S is gripped between the elastic layer 21 </ b> B and the free end side of the gripper 23. Then, the sheet S is wound around the transfer drum 21 while being held by the gripper 23, and is conveyed through the rotation path 53.
Note that the case where the paper S is supplied from the manual feed supply unit 60 attached to the attachment unit 70 toward the transfer drum 21 will be described later.

  Next, the first (for example, yellow) toner image formed on the photosensitive drum 11 is transferred to the sheet S on the transfer drum 21 at the transfer portion T where the photosensitive drum 11 and the transfer drum 21 face each other. The The toner remaining on the photosensitive drum 11 after the transfer is removed by the cleaning device 15.

When multiple image formation is performed, the second and subsequent (for example, magenta, cyan, and black) latent image formation, development, and transfer are similarly repeated according to the above-described procedure. However, when each color toner image is formed, the rotary developing device 14 rotates, and the corresponding developing devices 14M, 14C, and 14K are arranged at the stop positions.
In the meantime, the sheet S is rotated and conveyed on the rotation path 53 while being gripped by the transfer drum 21 by the gripper 23, and is sequentially transferred so that the second and subsequent toner images are overlapped each time it passes through the transfer portion T. . As a result, for example, when full-color image formation is performed, toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) are transferred onto the sheet S on the transfer drum 21 in a multiple transfer manner. Is done.

  When the last (for example, black) transfer is finished, the gripper 23 releases (releases) the gripping of the paper S onto the transfer drum 21, and the paper S on which the toner image is transferred is separated from the transfer drum 21 and discharged. It enters the discharge path 52 from the position Pb and is sent to the fixing nip portion where the heating roll 31 and the pressure roll 32 as the fixing device 30 are in pressure contact. The toner image held on the sheet S is fixed at the fixing nip portion. The sheet S after completion of fixing is discharged out of the image forming apparatus 1 by the transport roll 44 and is stacked on the paper discharge stacking unit 3.

  Here, the case where the paper S is supplied from the manual feed portion 60 attached to the attachment portion 70 will be described.

  For example, when the paper S is supplied from the manual feed supply unit 60 attached to the lower attachment unit 70 in FIG. 1, the paper S taken out from the manual paper storage unit 61 by the manual feed roll 62 is transferred to the first hand. The paper is sent to the differential paper feed path 54. At this time, based on the phase of the transfer drum 21 obtained by the phase sensor 25, the sheet S is moved to the first manual feed position P1 as the gripper 23 reaches the first manual feed position P1. The conveyance control is performed so as to reach. Then, as the end of the sheet S in the traveling direction reaches the first manual sheet feeding position P1, the gripper 23 shifts from an open state to a closed state. Accordingly, the end portion of the sheet S is gripped between the elastic layer 21 </ b> B and the free end side of the gripper 23. Then, the sheet S is wound around the transfer drum 21 while being held by the gripper 23, and is conveyed through the rotation path 53.

  Similarly, for example, when the paper S is supplied from the manual paper supply unit 60 attached to the middle attachment unit 70 in FIG. 1, the paper S taken out from the manual paper storage unit 61 by the manual paper supply roll 62 is used. The sheet is fed to the second manual feed path 55 and conveyed through the rotation path 53. Further, for example, when the paper S is supplied from the manual feeding unit 60 attached to the upper mounting unit 70 in FIG. 1, the paper S taken out from the manual paper storage unit 61 by the manual feeding roll 62 is used. The paper is fed to the three-manual paper feed path 56 and conveyed through the rotation path 53.

  Hereinafter, although detailed description is omitted, in accordance with the above-described procedure, the transfer of the toner image onto the paper S held on the transfer drum 21, the release of the paper S onto which the toner image has been transferred from the transfer drum 21, and the paper S The toner image is fixed to the sheet and the sheet S after the fixing is discharged.

FIG. 3 is a view for explaining the relationship between the transfer drum 21 and the mounting portion 70 in the image forming apparatus 1 according to another embodiment.
In the example shown in FIG. 3, only one attachment portion 70 is provided for the housing 2, and the attachment portion 70 is centered on a rotating shaft (not shown) provided on the housing 2. It is provided so as to be swingable in the direction of the middle arrow D. The rotation axis of the attachment portion 70 is preferably coaxial with the rotation axis of the transfer drum 21.

  The image forming apparatus 1 is provided with a manual paper feed path 57 for supplying the paper S from the manual paper supply unit 60 attached to the attachment unit 70 toward the outer peripheral surface of the transfer drum 21. In the present embodiment, the manual feed path 57 is also moved as the mounting portion 70 is moved in the direction of arrow D. For this reason, the manual feed path 57 is upstream in the rotation direction of the transfer drum 21 with respect to the transfer portion T and the paper feed position Pa, and is downstream in the rotation direction of the transfer drum 21 with respect to the transfer portion T and the paper discharge position Pb. Is configured to supply the paper S toward any position in the manual feed supply range P0.

  As described above, in the present embodiment, when the paper S is supplied from the paper supply unit 40 (not shown) and when the paper S is supplied from the manual supply unit 60 attached to the attachment unit 70, The paper feed position with respect to the transfer drum 21 is made different. Further, in the present embodiment, the paper feed position with respect to the transfer drum 21 is made different depending on the position where the attachment portion 70 to which the manual feeding portion 60 is attached is fixed.

  Further, in the present embodiment, the outlet side of the manual feed path 57 for feeding the paper S from the manual feed section 60 attached to the mounting section 70 is the outer peripheral surface of the transfer drum 21 regardless of the position of the mounting section 70. In contrast, the direction is tangential to the downstream side of the transfer drum 21 in the rotation direction (arrow B direction). As a result, the sheet S supplied from the manual feed supply unit 60 attached to the attachment unit 70 is configured to be supplied from the tangential direction of the transfer drum 21.

  In the present embodiment, the manual feed sensor 72 is configured to measure the position (angle) of the attachment portion 70 with respect to the housing 2. When an image is formed on the paper S supplied from the manual feeding unit 60 attached to the attachment unit 70, the control unit 100 is based on the detection result of the position of the attachment unit 70 by the manual feed sensor 72. The supply control of the paper S is performed.

  The attachment portion 70 can be fixed to the housing 2 at a plurality of positions (angles). In this case, for example, a ratchet mechanism or a fixing member that can be fixed at an arbitrary position can be separately provided. Further, the mounting portion 70 can set the fixed position steplessly without restricting the fixed position with respect to the housing 2.

  In the present embodiment, for example, when the paper P is supplied to the transfer drum 21 from the manual feed portion 60 attached to the attachment portion 70, the paper S taken out from the manual paper feed portion 61 by the manual feed roll 62. To the movable manual feed path 54. At this time, the sheet S is fed in accordance with the gripper 23 reaching the sheet feeding position selected from the manual sheet feeding range P0 based on the phase of the transfer drum 21 obtained by the phase sensor 25. The conveyance control is performed so as to reach the position. Then, as the edge of the sheet S in the traveling direction reaches the sheet feeding position, the gripper 23 shifts from an open state to a closed state. Accordingly, the end portion of the sheet S is gripped between the elastic layer 21 </ b> B and the free end side of the gripper 23. Then, the sheet S is wound around the transfer drum 21 while being held by the gripper 23, and is conveyed along the rotation path 53.

  In the above-described embodiments, the manual supply unit 60 is described as including the manual extraction drive source 63. However, the manual supply unit 60 may be configured not to include the manual extraction drive source 63. In this case, for example, the transfer drum 21 has a large-diameter rotation shaft gear (not shown) provided on the rotation shaft, and the rotation shaft can be rotated regardless of the position of the manual paper storage portion 61. The manual feed roll 62 has a gear that meshes with the gear. With this configuration, the manual feed roll 62 can be driven by driving the rotation shaft of the transfer drum 21.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Housing, 3 ... Discharge stacking part, 10 ... Image forming part, 11 ... Photosensitive drum, 12 ... Charging device, 13 ... Exposure device, 14 ... Rotary developing device, 15 ... Cleaning device, DESCRIPTION OF SYMBOLS 20 ... Transfer device, 21 ... Transfer drum, 21A ... Base part, 21B ... Elastic layer, 21C ... Exposed part, 23 ... Gripper, 25 ... Phase sensor, 30 ... Fixing device, 40 ... Paper supply part, 41 ... Paper storage part, 42 ... take-out roll, 43 ... paper roll, 44 ... transport roll, 51 ... supply path, 52 ... discharge path, 53 ... rotation path, 60 ... manual feed section, 61 ... manual paper storage section, 62 ... manual feed Roll, 63 ... Manual feed drive source, 70 ... Mounting part, 71 ... Support part, 72 ... Manual feed sensor, 100 ... Control part, S ... Paper

Claims (7)

An image carrier that is rotatably arranged and holds an image on an outer peripheral surface;
A transfer member that is rotatably disposed opposite to the image carrier and that transfers an image held on the image carrier to a recording material sandwiched between the image carrier and the image carrier;
Holding means for holding the recording material supplied toward the outer peripheral surface of the transfer member;
An image forming apparatus comprising: a supply unit that supplies the recording material toward different positions on the periphery of the transfer member.   The image forming apparatus according to claim 1, wherein the holding unit is a holding member that holds the recording material between the transfer member and the holding member.   The gripping member changes a timing to start gripping the supplied recording material depending on a position around the transfer member to which the feeding unit supplies the recording material. The image forming apparatus according to claim 2. The image holding body sequentially holds images of different colors and sequentially transfers the held images of each color to the recording material gripped by the transfer member by the gripping member one by one,
The gripping member releases the gripping of the recording material with respect to the transfer member after the last color image is transferred from the image holding member to the recording material gripped by the transfer member. The image forming apparatus according to claim 2.   5. The recording apparatus according to claim 1, wherein the supply unit supplies the recording material along a rotation direction of the transfer member and a tangential direction of the outer peripheral surface of the transfer member at each of the peripheral positions. The image forming apparatus according to claim 1.   6. The supply unit according to claim 1, wherein the supply unit includes a plurality of supply paths that are provided around the transfer member and supply the recording material to the transfer member from different positions. Image forming apparatus.   6. The supply unit according to claim 1, further comprising a single supply path that is provided so as to be movable around the transfer member and that supplies the recording material to the transfer member from different positions. 2. An image forming apparatus according to item 1.

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