JPH0736095B2 - Transfer device of image forming apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a corona discharger for an image forming apparatus including a belt-shaped photoconductor having a deviation adjusting roller, and more particularly, to a mutual position adjustment between the photoconductor and the corona discharger. is there.

2. Description of the Related Art In electrostatic copying machines, there are several known mechanisms for releasing the corona discharger from the photoconductor in order to remove the transfer paper from around the photoconductor when jammed, and when setting this corona discharger. In addition, some of them also have means for restricting the photoconductor and the corona discharger to a predetermined distance. However, in most of these cases, the photosensitive member is not displaced as in the case of the drum-shaped photosensitive member. In an adjustable copying machine, the position of the belt-shaped photoconductor is displaced by the adjustment of the deviation adjustment roller, and the gap between the belt-shaped photoconductor and the corona discharger is changed, so that the predetermined discharge cannot be performed. Sometimes.

Purpose As described above, in the image forming apparatus having the belt-shaped photoconductor provided with the deviation adjusting device, when the belt-shaped photoconductor is displaced by the deviation adjusting operation, the distance between the belt-shaped photoconductor and the corona discharger provided opposite thereto changes. Then, there is a possibility that the desired charging cannot be performed, but in the present invention, even if the belt-shaped photoconductor is displaced by the deviation adjustment operation, the belt-shaped photoconductor is always kept at a constant distance. It is intended to provide a corona discharger.

The present invention relates to a belt-shaped photosensitive member for image formation stretched in a transfer device of an image forming apparatus, a tiltable offset adjusting roller for stretching the belt photosensitive member and adjusting the offset of the belt photosensitive member, and the offset adjustment. An edge adjusting roller supporting plate that supports the roller and tilts integrally with the edge adjusting roller, and is adjustably attached to the machine frame, a discharge wire for transferring a toner image from a belt photosensitive member to a transfer sheet, and an end of the discharge wire. A transfer member provided at a position facing the belt-shaped photoconductor stretched by the deviation adjusting roller, and a biasing member for constantly supporting the transfer device in the direction of the belt photoconductor by elastic means. The transfer wire supporting member of the transfer means is brought into contact with the deviation adjusting roller support plate or the deviation adjusting roller support shaft. In conjunction with tilting of the deviation adjustment roller,
Only the driving means is tilted with respect to the transfer unit through the elastic means so that the gap between the belt-shaped photoreceptor and the discharge wire of the transfer means is kept constant. Hereinafter, the present invention will be described with reference to the drawings. An example will be described.

FIG. 1 is a side view showing the overall structure of the image forming apparatus according to the present invention, FIG. 2 is a side view showing the relationship between the transfer separation charger and the belt-shaped photoreceptor in FIG. 1, and FIG. 3 is a deviation adjusting roller. FIG. 4 is a cross-sectional view showing the relationship with a corona discharger, FIG. 4 is a perspective view showing a deviation adjusting device, and FIGS. 5 and 6 are all the same as FIG. 3 showing a state in which the deviation adjusting roller is adjusted and displaced. FIG. 7 is a view similar to FIG. 3 showing a modified embodiment,
Is.

In FIG. 1, the light source 2 is placed on the contact glass 1.
The original image illuminated by a and 2b is projected on the belt-shaped photoconductor 6 supported by the driving roller 18, the driven roller 19, and the deviation adjusting rollers 20 and 21 through the lens 3 and the mirrors 4 and 5. The toner image formed by the developing device 7 is transferred by the transfer charger 13 onto the transfer paper which is fed by the feed rollers 11a, 11b, 11c through the registration roller 12 at the same timing. Then, the transfer paper separated from the photoconductor by the separation charger 14 is discharged to the paper discharge tray 10 via the conveying device 28 and the fixing device 9. On the other hand, at the same time as the transfer, the photoconductor is destaticized by the destaticizing lamp 17, the residual toner after the transfer is cleaned by the cleaning device 8, and is recharged by the charging device 22. Around the belt-shaped photosensitive member 6, a transmissive optical sensor, conductive brushes 23a and 23b, an erase lamp 16, backup rollers 15a and 15b, and a light guide 25 are provided.

By the way, in the above process, the transfer paper cannot be completely avoided due to its nature of abnormal transfer (the transfer paper is not fed normally, and is torn, jammed, or stuck. Jam). , Transfer, separation charger 13,
A transfer separation unit (transfer unit) 30 in which a transfer unit 43 composed of 14 and a transfer device 28 are integrated as shown in FIG.
The jam paper generated at these portions can be easily removed.

That is, as shown in FIG. 2, the transfer charger 13, the separation charger 14, and the transport device 28 are rotatable about the drive roller 29a of the rollers 29a and 29b supporting the transport belt of the transport device 28. The transfer / separation / conveyance unit 30 is attached in series as shown in the figure, so that the transfer / separation / conveyance unit 30 can be rotated from the solid line position to the chain line position with respect to the pins / grooves. Lever 31 having a support shaft 31a provided on a rotating plate 31 for transmitting the rotation by the engagement with a lever 34 and a pin 34 at the other end for sliding a groove 35 provided on the machine frame.
One end of the drive roller 29a is rotatably coupled to the drive roller 29a and the pin 34
A spring 32 is provided between and. As shown in the figure, the support shaft 31a is moved beyond the line connecting the shaft center of the drive roller 29a and the center of the pin 34.
Since it is displaced to the position 31b, the transfer / separation / conveyance unit 30 is pushed by the spring 32 in either direction due to the dead point. Note that the clockwise rotation is restricted by the pin 36 in its rotation range. In the figure, reference numeral 26 is a transfer entrance guide, 27 is a separation guide, and 41 is a leaf spring.

FIG. 3 is a cross-sectional view showing the relational position between the belt-shaped photosensitive member 6 and the transfer (separation) charger. As shown in FIG. 4, the deviation adjusting rollers supporting the deviation adjusting rollers 20 and 21 on the left and right are supported. By adjusting and fixing the plates 39 and 40 to the machine frame 38 in the directions of the arrows A and B, the deviation adjustment of the photoconductor belt is performed. In the present invention, however, the end blocks 37a and 37b of the transfer (separation) charger are provided. Are respectively brought into contact with the side plates 39 and 40 for supporting the deviation adjusting rollers, so that the gap between the belt-shaped photosensitive member 6 and the corona discharge wire 42 is maintained in parallel and at a constant distance. Therefore, a leaf spring 41 is provided between the transfer / separation / conveyance unit 30 and the transfer (separation) charger so that the charger can be drivenly engaged with the deviation adjusting roller.

FIGS. 5 and 6 show that the transfer (separation) charger is always driven properly even if the side plates 39, 40 for supporting the deviation adjusting rollers are adjusted.
The corona discharge wire 42 is shown in a fixed position with respect to the belt-shaped photoreceptor 6. Further, FIG. 7 shows that the end blocks 37a and 37b of the charger are offset to the side plate 3 of the adjusting device.
This shows a modified example in which the end blocks are engaged with the deviation adjusting roller support shafts instead of being engaged with the members 9 and 40, and the same effect is obtained.

Note that the transfer (separation) charger is a transfer / separation / conveyance unit.
Even if it is displaced to some extent with respect to 30, there is no influence because the transfer device 28 can operate normally.

Effect Abnormality As described above, according to the present invention, in the image forming apparatus having the belt state light body provided with the deviation adjusting device,
Even if the belt-shaped photoconductor is displaced by the deviation adjustment operation, the corona discharger can always follow the belt-shaped photoconductor by keeping a constant distance. When the corona discharger can be easily contacted and separated and is set, the corona discharger will follow even when the photoconductor is displaced by adjusting the deviation and always keep a predetermined distance, so a constant corona discharge is performed at any time. be able to.

[Brief description of drawings]

FIG. 1 is a side view showing the overall structure of the image forming apparatus according to the present invention, FIG. 2 is a side view showing the relationship between the transfer separation charger and the belt-shaped photoreceptor in FIG. 1, and FIG. 3 is a deviation adjusting roller. FIG. 4 is a cross-sectional view showing the relationship with a corona discharger, FIG. 4 is a perspective view showing a deviation adjusting device, and FIGS. 5 and 6 are all the same as FIG. 3 showing a state in which the deviation adjusting roller is adjusted and displaced. FIG. 7 is a view similar to FIG. 3 showing a modified embodiment,
Is. 6 ... Belt-shaped photoreceptor, 7 ... Developing device, 8 ... Cleaning device, 8 ... Fixing device, 13 ... Transfer charger, 14 ... Separation charger, 20, 21 ... Offset adjusting roller, 28 ... Conveyor, 30 …… Transfer / separation / conveyance unit (transfer unit), 31 ……
Tongue, 32 …… Spring, 33 …… Lever, 37a, 37b …… End block, 38 …… Machine frame, 39,40 …… Side adjustment roller support side plate, 41 …… Leaf spring, 42 …… Discharge wire, 43 …… Transfer means.

Claims (1)

[Claims] 1. A belt-shaped photosensitive member for image formation stretched, a tiltable deviation adjusting roller for stretching the belt photosensitive member and adjusting deviation of the belt photosensitive member, and a deviation adjusting roller for supporting the deviation adjusting roller. A tilt adjustment roller support plate that tilts integrally with the machine frame and is adjustably attached to the machine frame, a discharge wire for transferring a toner image from the belt photosensitive member to the transfer paper, and a support member that supports the end portion of the discharge wire. A transfer unit provided at a position facing the belt-shaped photoconductor stretched by the deviation adjusting roller, and the transfer unit is constantly urged and supported by an elastic unit in the direction of the belt photoconductor to contact the photoconductor. A transfer unit provided so as to be separable, and the discharge wire supporting member of the transfer means is brought into contact with the deviation adjusting roller support plate or the deviation adjusting roller support shaft to tilt the deviation adjusting roller. The image forming apparatus is configured to move and tilt only the driving unit with respect to the transfer unit through the elastic unit to keep the gap between the belt-shaped photoconductor and the discharge wire of the transfer unit constant. Transfer device.