JPS61259280A - Corona discharger of image forming device - Google Patents

Abstract

PURPOSE:To keep the space between a photosensitive body and a discharger at a specified distance and make constant corona discharge possible by bringing a discharger end block into contact with the supporting side boards of bias adjusting rollers when the corona discharger approaches the photosensitive body side. CONSTITUTION:Bias adjusting of a photosensitive body belt is made adjusting and fixing bias adjusting roller supporting boards 39, 40 that support bias adjusting rollers 20, 21 to a machine frame. At this time, end blocks 37a, 37b of a transfer charger come into contact with supporting side boards 39, 40 of adjusting rollers, and the space between a beltlike photosensitive body 6 and a corona discharging wire 42 is kept parallel and at a fixed distance. Thus, the discharger is made to follow the photosensitive body 6 keeping a fixed distance for displacement of the photosensitive body 6 by bias adjusting. The discharger can be attached and detached to and from the photosensitive body 6 at the time of jamming, and constant corona discharge can be made in the set state.

Description

[[[ 1.

How many mechanisms are known for releasing the corona discharger from the photoconductor in order to remove transfer paper from around the photoconductor in the event of a jam in electrostatic copying machines? Some devices also include means for regulating the distance between the photoreceptor and the corona discharger at a predetermined distance. However, in most of these, the photoconductor does not displace as in the case of a drum-shaped photoconductor, and a belt-shaped photoconductor is used, and the belt of the belt-shaped photoconductor is not shifted by a deviation adjustment roller. In a copying machine that is adjustable, the position of the belt-shaped photoreceptor is displaced by adjusting the offset adjustment roller, and the gap between the belt-shaped photoreceptor and the corona discharger changes, so that a predetermined discharge cannot be performed ( Sometimes it happens.

As described above, in an image forming apparatus having a belt-shaped photoreceptor equipped with an offset adjustment device, when the belt-shaped photoreceptor is displaced by an offset adjustment operation, the distance from the corona discharger installed opposite to it increases. However, in the present invention, even if the belt-shaped photoconductor is displaced due to the offset adjustment operation, it always follows the belt-shaped photoconductor while maintaining a constant distance. The corona discharger
This is what we are trying to provide.

1. The present invention provides an image forming apparatus equipped with a corona discharger that faces a belt-shaped photoreceptor and applies an electric charge to the belt-shaped photoreceptor, which has an offset adjustment roller. When the corona discharger is brought close to the photoreceptor side, the end block of the corona discharger comes into contact with the side plate supporting the offset adjustment roller or the support shaft of the adjustment roller, and the belt-shaped photoreceptor The present invention will be explained below according to embodiments shown in the drawings.

FIG. 1 is a side view showing the overall configuration of an 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. FIG. 4 is a cross-sectional view showing the relationship with the corona discharger, FIG. 4 is a perspective view showing the deviation adjustment device, and FIGS. 5 and 6 are similar to FIG. 7 is a diagram similar to FIG. 3 showing a modified embodiment,
It is.

In FIG. 1, a light source 2 is placed on a contact glass l.
The original image illuminated by lenses 3.a and 2b is illuminated by lenses 3. Via the mirror 4.5, the drive roller 18. Followed roller I'll
, the toner image projected onto the belt-shaped photoreceptor 6 supported by the offset adjustment rollers 20, 21 and formed by the developing device 7 is sent via the registration roller 12 by feed rollers lla, 11b, and lie at the same timing. The transfer charger 12 transfers the image onto a transfer paper. Then, the transfer paper separated from the photoreceptor by the separation charger 13 is discharged to the paper discharge tray 1O via the conveyance device 28 and the fixing device 9. On the other hand, at the same time as the transfer, the photoreceptor is neutralized by the static elimination lamp 17, the residual toner after the transfer is cleaned by the cleaning device 8, and the photoreceptor is charged again by the charging device 22. A transmission type optical sensor 24, conductive brushes 23a and 23b, an erase lamp 16, backup rollers 15a and 15b, and a light guide 25 are provided around the belt-shaped photoreceptor 6.

By the way, in the above process, due to the nature of transfer paper conveyance, it is impossible to completely avoid abnormal conveyance (transfer paper not being fed normally and being torn, clogged, stuck, etc.). , transfer, separation charger 13
．． 14 and the conveyance device 28 are integrated as a transfer separation conveyance unit 30 as shown in FIG. 2, so that jammed paper can be easily removed at these parts.

That is, as shown in FIG. 2, the transfer charger 13, the separation charger 14, and the conveyance device 28 are rotatable around the drive roller 29a of the rollers 29a and 29b that support the conveyance belt of the conveyance device 28. As shown in the figure, the transfer separation and conveyance unit 30 is installed in series with the transfer separation and conveyance unit 30, so that the transfer separation and conveyance unit 30 can be rotated from the solid line position to the chain line position.
Rotating plate 31 for transmitting rotation by engagement of pins and grooves
One end of a lever 33 having a pin 34 sliding in a groove 35 provided in a machine frame at the other end is rotatably connected to a support shaft 31a provided in the machine frame, and a lever 33 is rotatably connected to the support shaft 31a provided in the machine frame. spring 3
2 is provided.

As shown in the figure, since the support shaft 31a is displaced to the position 31b beyond the line connecting the axis of the drive roller 29a and the center of the pin 34, the transfer separation conveyance unit 3
0 will be pushed by the spring 32 in either direction. Note that the range of rotation in the clockwise direction is restricted by the pin 36. In the figure, reference numeral 26 indicates a transfer entrance guide; 27
is a separation guide, and 41 is a leaf spring.

FIG. 3 is a sectional view showing the relative position of the belt-shaped photoreceptor 6 and the transfer (separation) charger. As shown in FIG. The offset of the photoreceptor belt is adjusted by adjusting and fixing the plates 39 and 40 to the machine frame 38 in the directions of arrows A and B. In the present invention, the end blocks 37a and 37b of the transfer (separation) charger are in contact with the offset adjustment roller support side plates 39 and 40, respectively, so that the gap between the belt-shaped photoreceptor 6 and the corona discharge wire 42 is kept parallel and at a constant distance. For this reason, a plate spring 41 is provided between the transfer separation and conveyance unit 30 and the transfer (separation) charger, so that the charger can be driven into engagement with the offset adjustment roller.

5 and 6 show how the transfer (separation) charger always follows correctly and the corona discharge wire 42 remains at a constant position with respect to the belt-shaped photoreceptor 6 even when the offset adjustment roller support side plates 39 and 40 are adjusted. It shows. Also, Figure 7 shows
A modification example is shown in which the end blocks 37a, 37b of the charger engage with the side plates 39, 40 of the shift adjustment device, but instead engage with the shift adjustment roller support shaft to achieve the same effect. It is something.

Note that even if the transfer (separation) charger is displaced to some extent with respect to the transfer separation and conveyance unit 30, the transfer device @28
can operate normally, so there is no effect.

As explained above, according to the present invention, in an image forming apparatus having a belt-shaped photoreceptor provided with a misalignment adjustment device,
Even if the belt-shaped photoconductor is displaced due to the offset adjustment operation, the corona discharger can always follow the belt-shaped photoconductor while maintaining a certain distance, so in the event of a jam, etc. The corona discharger can be easily brought in and out, and in the set state, the corona discharger follows even when the photoreceptor is displaced due to offset adjustment, and always maintains a predetermined distance, so a constant corona discharge is produced at all times. be able to.

[Brief explanation of drawings]

FIG. 2 is a side view showing the overall configuration of an 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. FIG. 4 is a cross-sectional view showing the relationship with the corona discharger, FIG. 4 is a perspective view showing the shifting plate device, and FIGS. 5 and 6 are the same as FIG. 3 showing the state in which the shifting adjustment roller has been adjusted and displaced. illustration. FIG. 7 is a diagram similar to FIG. 3 showing a modified embodiment. 6... Belt-shaped photoreceptor, 7... Developing device, 8...
...Cleaning device, 9...Fixing device, 13...
Transfer charger, 14... Separation charger, 20,
21... Misalignment adjustment roller, 28... Conveyance device, 30
...Transfer separation and conveyance unit, 31...Protrusion, 32.
...Spring, 33...Lever. :37a, 37b...end block, 38...
Machine frame, 39.40...Occurrence adjustment roller support side plate, 41
...Temporary spring, 42...Discharge wire.

Claims (1)

[Claims] In an image forming apparatus equipped with a corona discharger that faces a belt-like photoreceptor and applies an electric charge to the belt-like photoreceptor having an offset adjustment roller, the corona discharger can be moved in a direction toward and away from the belt-like photoreceptor. In addition, when the corona discharger is brought close to the photoreceptor side, the end block of the corona discharger comes into contact with the support side plate of the offset adjustment roller or the support shaft of the offset adjustment roller, and the contact between the belt-shaped photoreceptor and the corona discharger is caused. A corona discharger for an image forming apparatus, characterized in that the gap is always kept constant.