JPH04204979A - Transfer device - Google Patents

Abstract

PURPOSE:To facilitate JAM processing and to prevent the dropping of toner by moving a transfer unit in which a transfer member is incorporated in an up-and-down direction while it keeps a horizontal state with respect to a photosensitive body side. CONSTITUTION:The transfer unit 15 descends to a side below the photosensitive body 1 in a horizontal state through a cam mechanism 19 together with respective guiding plates 22 and 22 provided in respective supporting members 16 and 16. Therefore, wide working space is secured between the photosensitive body 1 and the transfer unit 15, so that work is very easily performed in the case of performing the JAM processing. Since the transfer unit 15 descends while keeping the horizontal state, the dropping of the toner of a transfer roller 11 incorporated in the transfer unit 15 is not caused.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a transfer device installed in an image forming apparatus.

(Prior Art) Conventionally, this type of transfer device is disclosed in, for example, Japanese Patent Application Laid-Open No. 51-128.
As described in Japanese Patent No. 538, a transfer unit incorporates a transfer roller that comes into contact with the photoreceptor side, a guide plate that guides a transfer material such as transfer paper toward the photoreceptor side, etc. at a lower position of the photoreceptor. The side of the transfer unit opposite to the guide plate is cantilever-supported so that it can be moved close to and away from the transfer roller or photoreceptor side, and the transfer unit is supported by an electric separating device equipped with a solenoid or the like. It is linked to the contact mechanism. When transferring an image to the transfer body, the transfer unit is separated from the photoconductor side by the operation of the electric separation mechanism within a predetermined time range until the transfer body is conveyed to the photoconductor side. This prevents wear and damage caused by constant contact between the photoconductor and the transfer roller, and when the transfer body is conveyed to the photoconductor side, the transfer is performed by the operation of the electric separation mechanism. The unit is moved close to the photoreceptor side, and the toner image on the photoreceptor side is transferred to the transfer member conveyed between the photoreceptor and the transfer roller of the transfer unit. Further, when a paper jam occurs between the transfer unit and the photoreceptor and the jammed paper is to be removed, or when performing a so-called JAM process, the electric separation mechanism is activated to remove the jammed paper from the transfer unit. is separated from the photoconductor side, and a work space is secured between the photoconductor and the transfer unit to perform the JAM processing.

(Problem to be Solved by the Invention) However, in the above-described transfer device, since the transfer unit incorporating the transfer roller, the guide plate, etc. is supported in a cantilever manner, when performing JAM processing, Even if the transfer unit is separated from the photoreceptor, it is difficult to secure a large working space between the photoreceptor and the transfer unit, resulting in poor workability. When the transfer roller incorporated in the transfer unit separates from the photoreceptor, the toner on the transfer roller may fall off or adhere to the surrounding area. Moreover, the electric separation mechanism of the transfer unit is However, there were also problems in that the number of parts was large and it was very complicated, resulting in high costs.

The present invention has been made in view of the above-mentioned transfer problem.The purpose of the present invention is to secure a large working space between the photoreceptor and the transfer unit, and to prevent toner from falling off. An object of the present invention is to provide a transfer device.

(Means for Solving the Problems) In order to achieve the above object, the transfer device of the present invention has a transfer unit in which a transfer member is incorporated, which is not held in a horizontal position below the photoreceptor. The image forming apparatus is characterized in that it is supported so as to be horizontally movable and further includes a separation mechanism that horizontally moves the transfer unit relative to the photoreceptor side.

(Function) According to the above configuration, when JAM processing is performed, the transfer unit is moved and separated while maintaining a horizontal position below the photoreceptor by the operation of the separation mechanism. A wide working space is secured between the transfer unit and the photoconductor, making it extremely easy to perform the JAIVI process, and the transfer unit can be moved while maintaining a horizontal position with respect to the photoconductor. Therefore, there is no possibility of toner falling on the transfer roller incorporated in the transfer unit.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows the overall structure of an image forming apparatus equipped with a transfer device of the present invention. In the figure, 1 is a photoreceptor that is rotatably supported, 2 is a cleaning unit for the photoreceptor 1,
3 is a developing section, and 4 is a transfer device disposed below the photoreceptor 1. Reference numeral 5 denotes a paper feed box containing a transfer body 6 such as transfer paper, and between this paper feed box 5 and the transfer device 4, there is a pair of upper and lower paper feed rollers 7.7 facing each other.
A paper feed detection switch RS is provided immediately upstream of each paper feed roller 7 to detect paper feeding of the transfer body 6.
Also, on the downstream side of the transfer device 4, a fixing section 9 including a conveyor belt 8 and a plurality of rollers 91 is provided.
An ejection detection switch ESW for detecting ejection of the transfer body 6 is provided downstream of the fixing section 9.

As is clear from FIGS. 2 and 3, the transfer device 4 has the following features:
A transfer roller 11 as an example of a transfer member rotatably supported with an outer peripheral portion exposed upward on the inner upper side of the unit case 10, and a transfer roller 11 always in contact with the inner intermediate portion of the unit case 10. A conductive cleaning fur brush 12 supported by
2 cleaning roller 13 and cleaning roller 1
4, the unit case 10. Transfer roller 11
．． Far flage 12. The cleaning roller 13 and the cleaning roller 14 constitute a transfer unit 15. The transfer roller 11, fur brush 12, and cleaning roller 13 are each connected to a high voltage power source E.
This high-voltage power supply E is used to apply a predetermined charge to each of the above-mentioned cells. Further, a drive roller R connected to a belt drive motor M that drives the conveyor belt 8 is provided on the unit case 10 side, and the rotation of the drive roller R causes the cleaning roller 13 and the The fur brush 12 and the like are configured to rotate.

Then, on both sides of the front and back of the unit case IO,
Each supporting member 16.16 is integrally provided, and a long hole 17 extending in the vertical direction is provided at the lower side of each supporting member 16.16.
, 17 are formed, and the shaft rods [, 18 extending from the fixing member side of the image forming apparatus are inserted into the member holes 17, 17, and the shaft rods 18, 1g and the elongated holes 17, 17 are connected to each other. The entire transfer unit 15 is supported so as to be horizontally movable in the vertical direction relative to the photoreceptor 1 side.

Further, on the lower side of the transfer unit 15, a cam mechanism 19 (an example of a detachment mechanism) is disposed for moving the entire transfer unit 15 in the vertical direction with respect to the photoreceptor 1 while keeping it in a horizontal position. The cam mechanism 19 includes an eccentric cam 21 that is supported by a support shaft 20 and comes into contact with the lower surface side of the unit case 10, and a drive motor TRM that rotationally drives the eccentric cam 21. , this motor TR
The eccentric cam 21 is configured to be rotated by the drive of the motor M via a gear mechanism.

Furthermore, each support member 16 provided on the unit coos 10
．． Front and rear guide plates 22, 22 for guiding the transfer body 6 are integrally attached to the upper side of the transfer body 16.

Next, the operation of the above configuration will be explained with reference to the timing chart shown in FIG. First, when the print key switch KSl'l is turned on, the dry motor DM is driven to start rotating the photoreceptor 1, and
The motor TRM of the cam machine [19 is driven and the eccentric cam 21 is rotated approximately half a rotation, and the transfer unit throat 1 is rotated along with the guide plates 22 and 22 provided on the support member 16 and 16.
5 is lifted upward in a horizontal position from the state shown in FIG. 2 to the state shown in FIG. Afterwards, the motor TRM is once turned off,
The transfer unit 15 is held in a lifted state. Furthermore, at the same time as the print key switch KSIII is turned on, charges BHVT are applied to the fur brush 12 and charges CH to IT are applied to the cleaning roller 13. The transfer roller 11 is cleaned by the roller I3.

Then, when the transfer body 6 is supplied and conveyed from the paper feed box 5 side and the paper feed detection switch R3III is turned on, a charge THVT is imprinted on the transfer roller 11 at a predetermined timing from this on operation. The toner image on the photoreceptor 1 side is transferred to the transfer member 6 conveyed between the transfer roller 11 and the photoreceptor 1, and the paper feed detection switch R3I'l is activated to detect the passage of the transfer member 6. After it is turned off it will be operated. Further, the transfer body 6 on which the image has been transferred is conveyed to the fixing unit 9 side via the conveyor belt 8, and when the image is fixed in this fixing unit 9 and is discharged to the outside, the discharge detection switch ESIII is turned on, and after a predetermined timing from this on operation, the charge T on the transfer roller 11 side is reduced.
HVT is eliminated. The above-mentioned operations are similarly performed when the next transfer body 6 is conveyed and supplied subsequent to the transfer body 6.

Furthermore, when the image transfer to all the transfer bodies 6 is completed, after a predetermined period of time has elapsed since the ejection detection switch ESW was turned off on the final transfer body 6, the motor TRM of the cam mechanism 19 is driven again to correct the eccentricity. The cam 21 is rotated approximately half a turn, and the entire transfer unit 15 is lowered horizontally so that the transfer roller 11 is separated from the photoreceptor 1.
After the motor TRM is stopped and a predetermined time elapses after the SW is turned off, the drive motor is stopped to open, and the electric charge BHVT of the fur brush 12 and the electric charge CHVT of the cleaning roller 13 are changed. will disappear together.

In addition, when a paper jam or the like occurs during image transfer to the transfer body 6 as described above and JAM processing is performed, the paper feed detection switch R3III and the ejection detection switch ESW control the motor TRM of the cam mechanism 19. is automatically driven, and the entire transfer unit 15 is lowered to a position below the photoreceptor 1 while maintaining a horizontal position.
Therefore, JAM processing can be performed easily and is very convenient. Further, the transfer unit 15 includes each of the support members 16.1.
Since the guide plates 22 and 22 provided on the photoreceptor 1 and the transfer unit 15 are lowered horizontally to the lower side of the photoreceptor 1 via the cam mechanism 19, there is a large space between the photoreceptor 1 and the transfer unit 15. A space is secured, which makes it very easy to perform the JAM process, and since the transfer unit 15 is lowered while maintaining a horizontal position, the transfer port 11 incorporated in the transfer unit 15 is In addition, the transfer unit 1
Since the vertical movement of 5 is performed via the cam mechanism 19, the structure is simple and costs can be reduced.

<Effects of the Invention> As explained above, according to the transfer device of the present invention, the transfer unit in which the transfer member is incorporated is supported on the lower side of the photoreceptor so that it can be horizontally moved while maintaining a horizontal position. In addition, since a separation mechanism is provided to horizontally move the transfer unit relative to the photoreceptor side, a large working space is secured between the photoreceptor and the transfer unit, which is very convenient when performing JAM processing. Moreover, when performing JAM processing, toner dropout and the like will not occur.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the overall structure of an image forming apparatus employing the transfer device of the present invention, and FIGS. 2 and 3 are side views showing main parts of the transfer device. Figure 3 shows a state in which the unit is separated from the photoconductor, and Figure 3 shows a state in which the transfer unit is brought close to the photoconductor.
The figure is a timing chart diagram of the same transfer unit. 1...Photoreceptor, 11...Transfer roller, 15...
...Transfer unit, 19...Cam mechanism.

Claims (1)

[Claims] A transfer unit incorporating a transfer member is supported on the lower side of the photoconductor so as to be horizontally movable while maintaining a horizontal position, and a separation mechanism is provided for horizontally moving the transfer unit with respect to the photoconductor side. Characteristic transcription device.