JPH0747394Y2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is directed to a first position at which a toner image formed on a latent image carrier can be transferred onto a transfer sheet, and a latent image carrier more than the first position. Transfer means movable between the second position retracted from the
A pair of upper and lower guide plates that are provided on the upper and lower sides of a transfer sheet path to the transfer section between the transfer unit and the latent image carrier at the first position and guide the transfer sheet to the transfer section; The guide plate moves integrally with the transfer means, and occupies a position for guiding the transfer paper to the transfer portion when the transfer means is at the first position,
The present invention relates to an image forming apparatus that is displaced to a position where the distance between the transfer unit and the latent image carrier is widened when the transfer unit is in the second position.

[Conventional technology]

In an image forming apparatus such as an electrophotographic copying machine, a laser printer, and a facsimile, a toner image formed on a latent image carrier is transferred onto a transfer paper that is conveyed to a transfer section between the latent image carrier and a transfer unit. The transfer paper is transferred by the action of the means, and then this transfer paper is separated from the latent image carrier and conveyed to the fixing device, where the toner image is fixed on the transfer paper.

In a conventional guide device for guiding a transfer sheet to a transfer section, as shown in FIG. 3, the transfer sheet 8 sent out from a pair of registration rollers 2 and 3 is integrated into a transfer charger and a separation charger which are examples of transfer means. The transfer / separation charger (hereinafter abbreviated as “transfer charger”) 6 and the photoconductor drum 1 which is one configuration example of the latent image carrier are guided to the transfer portion by sandwiching the transfer paper path. Upper guide plate 4 and lower guide plate 5
Is provided. The toner image formed on the photoconductor drum 1 is transferred onto the transfer paper 8 guided by the upper and lower guide plates 4 and 5 and conveyed to the transfer portion under the action of the transfer charger of the transfer charger 6. , Then this transfer paper 8
Separation charger for transfer charger 6 and photosensitive drum 1
It is separated from the photoconductor drum 1 by the separation claw 7 that is in contact with the tip of the toe, and is conveyed toward a fixing device (not shown).

The transfer paper may jam at the entrance of the transfer charger 6, the contact portion of the separation claw 7, or the like. Therefore, in the case of the apparatus of this example, as shown in FIG. 4, the lower guide plate 5 is integrally fixed and attached to the casing of the diversion charger 6, and when a jam occurs, the diversion charger 6 is attached to the lower guide plate 5. The transfer paper 8 which is jammed while being rotated in a direction away from the photoconductor drum 1 around the integral shaft to widen the gap between the photoconductor drum 1 and the upper guide plate 4 is taken out from the gap.

The method of enlarging the conveyance path for the jammed paper treatment is not limited to this. For example, in Japanese Utility Model Laid-Open No. 56-150949, the upper and lower guide plates of the transfer paper conveyance path from the registration roller pair to the transfer section are described. Either one of them is rotatably biased by a spring or its own weight, and is normally held at a predetermined transfer paper guide position by its biasing force, and the jamming process widens the conveyance path against the biasing force. An image forming apparatus is disclosed in which the jammed paper is taken out by displacing the jammed paper.

However, in the examples described in FIGS. 3 and 4 and the example disclosed in Japanese Utility Model Laid-Open No. 56-150949, the jammed transfer paper is strongly attracted to the photosensitive drum by electrostatic force. However, it is necessary to manually peel this from the photosensitive drum. This operation is not easy for the operator and may damage the photoconductor drum.

[Problems to be solved by the device]

In view of the above conventional problems, the present invention automatically and reliably transfers the transfer paper from the latent image carrier when the transfer means and the lower guide plate are retracted from the latent image carrier to remove the jammed paper. An object of the present invention is to provide an image forming apparatus capable of easily removing jammed paper without peeling and damaging the latent image carrier.

[Means for Solving the Problems]

In order to solve the above problems, the transfer paper guiding device of the present invention is the image forming apparatus described at the beginning, and in the image forming device described above, a means for urging the upper guide plate in a direction away from the latent image carrier and a transfer device. The upper guide plate is held at a predetermined guide position against the biasing force of the biasing means when the means is in the first position, and the upper guide plate carries the latent image when the transfer means is in the second position. And means for permitting movement in a direction away from the body.

[Action]

With the above configuration, when the transfer unit is retracted from the latent image carrier for the jam paper treatment, the lower guide plate moves integrally with the transfer unit in the direction away from the latent image carrier, and the upper guide plate is urged. It moves in the direction away from the latent image carrier by the biasing force of the means. As a result, the transfer paper adsorbed on the latent image carrier is peeled off by the upper guide plate and can be easily removed by the operator, and scratches on the latent image carrier can be prevented.

〔Example〕

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

1 and 2 are views showing an embodiment in which the present invention is applied to the image forming apparatus described above with reference to FIGS. 3 and 4. Therefore, members having the same functions as those described above are designated by the same reference numerals, and different points will be mainly described.

Also in this embodiment, the transfer charger 6 has the first position (FIG. 1) at which the toner image formed on the photosensitive drum 1 which is one example of the latent image carrier can be transferred to the transfer paper 8 and The second position (the second position) retracted from the photosensitive drum 1 rather than the position.
(Fig.) Is supported so as to be movable. A pair of upper and lower parts for guiding the transfer paper 8 to the transfer part are provided on both upper and lower sides of a transfer paper path from the registration roller pair 2, 3 to the transfer part between the transfer charger 6 and the photosensitive drum 1 at the first position. Guide plates 4 and 5 are provided. Further, the lower guide plate 5 is formed integrally with the casing of the transfer charger 6 so as to move integrally with the transfer charger 6, and when the transfer charger 6 is at the first position, the transfer paper 8 is transferred to the transfer portion. When the transfer charger 6 is in the second position,
It is displaced to a position where the distance from the photosensitive drum 1 increases.

Further, in this embodiment, the upper guide plate 4 is pivotally supported around the shaft of the upper roller 2 of the registration roller pair, and the stopper pin 10 integrally provided on the guide plate 4 is provided.
A compression spring 9 is provided around the shaft between the upper guide plate 4 and the machine frame, and the upper guide plate 4 is biased in a counterclockwise direction around its swing axis. On the other hand, at the rear end of the lower guide plate 5 in the transfer paper conveyance direction, positioning projections 5'project upwardly on both sides that do not hinder the transfer paper 8 from being conveyed, and the transfer charger 6 is the first. In the case of the transferable first position shown in the figure, the upper guide plate 4 is pushed up against the urging force of the spring 9 by the positioning protrusion 5'and positioned to a position suitable for guiding the transfer sheet. To be done.

When the transfer charger 6 is retracted from the photosensitive drum 1 as shown in FIG. 2 to remove the jammed paper, the lower guide plate 5 is removed.
The positioning projection 5'is lowered integrally therewith, and accordingly, the upper guide plate 4 is rotated counterclockwise by the urging force of the spring 9, and the locking portion 10 provided on the head of the stopper pin 10 is rotated.
a engages with the edge of the hole provided in the machine frame and stops, and the upper guide plate 4 is positioned at the lowered position. In this state, between the photoconductor drum 1 and the transfer charger 6, and the upper and lower guide plates.
The intervals of 4 and 5 are necessary and sufficient for processing jammed paper.

By moving the front end of the upper guide plate 4 in the conveying direction away from the peripheral surface of the photosensitive drum 1, the jammed transfer paper 8 adsorbed on the photosensitive drum 1 is transferred to the upper guide plate 4.
It is pushed down by the tip of and is peeled off from the photosensitive drum.

As can be seen from the above description, in this embodiment, the means for urging the upper guide plate in the direction away from the latent image carrier is constituted by the compression coil spring 9, and the transfer means is the first. When in the 1st position, the upper guide plate is held at a predetermined guide position against the biasing force of the biasing means,
A positioning projection 5'constitutes a means for allowing the upper guide plate to move in a direction away from the latent image carrier when the transfer means is in the second position.
Of course, these means can be configured by other suitable configurations. For example, the spring 9 is eliminated, and the guide plate 4 is biased in the direction in which it is separated from the photosensitive drum 1 by the weight of the upper guide plate 4. In this case, the weight of the upper guide plate itself constitutes the biasing means. Further, the upper guide plate 4 can be pivotally supported at an appropriate position other than the registration roller 2 so as to be rotatable. Further, the spring 9 and the stopper pin 10 are not limited to those shown in the drawings, and may be any one as long as they fulfill the function of positioning the upper guide plate between the predetermined guide position and the lowered position. Further, the displacement of the upper and lower guide plates and the diverter charger does not have to be rotational movement, and they may be supported so as to move in parallel in the vertical direction. Further, the positioning protrusion may be directly attached to the lower guide plate, or may be attached to the transfer charger and moved integrally with the lower guide plate.

In the illustrated embodiment, the transfer charger, which is an example of the transfer unit, and the separation charger are configured as an integral transfer charger.However, these are separated from each other, or an image forming apparatus that does not have a separation charger or a transfer charger. The present invention can also be applied to an image forming apparatus in which the means includes a transfer roller or the like.

[Effect of device]

As described above, according to the present invention, the transfer means and the lower guide plate are retracted from the latent image carrier to treat the jammed paper, so that the transfer paper adsorbed on the latent image carrier can be peeled off. Therefore, the jammed transfer paper can be easily taken out, and the risk of scratching the latent image carrier is reduced.

[Brief description of drawings]

FIGS. 1 and 2 are partial sectional front views showing a transferable state and a jammed-out state of an embodiment of the present invention, and FIGS. 3 and 4 show a conventional configuration example. FIG. 3 is a partial sectional front view similar to FIGS. 1 and 2. 4 ... Upper guide plate, 5 ... Lower guide plate 8 ... Transfer paper

Claims (1)

[Scope of utility model registration request] 1. A movable position between a first position at which a toner image formed on a latent image carrier can be transferred onto a transfer sheet and a second position retracted from the latent image carrier relative to the first position. Transfer means, and a pair of upper and lower guide plates provided on both upper and lower sides of a transfer paper path to the transfer portion between the transfer means and the latent image carrier at the first position and guiding the transfer paper to the transfer portion. The lower guide plate moves integrally with the transfer means, occupies a position for guiding the transfer sheet to the transfer portion when the transfer means is at the first position, and when the transfer means is at the second position. In an image forming apparatus that is displaced to a position where the distance between the latent image carrier and the latent image carrier is widened, a means for urging the upper guide plate in a direction away from the latent image carrier and a transfer means are in a first position. At this time, the upper guide plate is held at a predetermined guide position against the urging force of the urging means, and An image forming apparatus comprising: means for allowing the upper guide plate to move in a direction away from the latent image carrier when the copying means is in the second position.