JPH0623901B2 - Image forming apparatus provided with sheet separating device - Google Patents

Description

The present invention relates to an image forming apparatus such as an electrophotographic apparatus including a sheet separating device.

[Conventional technology]

In the transfer and separation device of the conventional electrophotographic device, for example, in the transfer and separation device, the transfer paper is brought into close contact with the photoconductor by the transfer guide, and then the transfer charger is used to charge the back surface of the transfer paper with a polarity opposite to the polarity of the toner. After applying the electrostatic force, the toner on the surface of the photoconductor is transferred to the transfer paper, and then the separation charger is used.
AC discharge or DC discharge with the same polarity as the toner is added to remove the electric charge applied to the transfer paper at the time of transfer to reduce the attraction force between the transfer paper and the photoconductor, and the elastic force of the transfer paper. Was used to separate the transfer paper from the photoconductor. At this time, the transfer charge remains on the transfer paper even if the separation charge is removed. Due to this transfer charge, the transfer paper and the photoconductor still have an adsorbing force, so if there is toner on the photoconductor, the adhesion is not so strong and separation is easy, and conversely, if there is no toner at all, the adhesion to the photoconductor surface is low. However, it is very difficult to separate it. Therefore, in an electrophotographic apparatus with a detachable developing device, if the developing device is neglected to be set at a predetermined position, toner does not remain on the photoconductor even when copying is performed, and therefore the photoconductor of the transfer paper is not attached. However, there is a drawback in that separation is caused due to the adhesiveness to and jams frequently occur.

[Object of the Invention]

In view of the above, the present invention eliminates the above-mentioned drawbacks of the conventional example, and in a device including one or more detachable developing devices, causes failure of separation of the transfer paper even when failing to mount the developing device at a predetermined position. It is an object of the present invention to provide a sheet separating device that can discharge a sheet without the need.

〔Example〕

FIG. 1 is a schematic perspective view of an electrophotographic apparatus embodying the present invention. A primary charger 11 is provided on the surface of the photoconductor 10.
The developing device 13 develops the electrostatic latent image formed by irradiating the surface of the photoconductor uniformly charged with the image exposure 12 into a toner image, and the transfer paper 14 is brought into close contact with the photoconductor 10 by the transfer guide 14. After that, the transfer charger 15 is used on the back surface of the transfer paper 17 to charge the toner having a polarity opposite to the polarity of the toner, and the toner on the photoconductor 10 is transferred to the transfer paper 17 by using an electrostatic force. 16 is used to perform AC discharge or discharge in which DC discharge having the same polarity as the toner is added to remove the electric charge applied to the transfer paper 17 at the time of transfer to remove the attraction force between the transfer paper 17 and the photoconductor 10. Then, the transfer paper 17 is separated from the photoconductor 10 by utilizing the elastic force of the transfer paper 17, and the mounting state of the developing device 13 is detected by the connector pin 41 and the connector socket 42. Then, the high voltage generator 43 is controlled by this detection signal, and the developing device 13
, The transfer charger 15 and the separation charger 16 operate normally, and when the developing device 13 is not attached in a predetermined position, electrical discharge is made by not making electrical connection. If the configuration is not performed, even if the developing device 13 is forgotten to be inserted, or if improper mounting occurs, the transfer paper 17 is prevented from adhering to the surface of the photoconductor more than necessary, and the jam can be prevented and separated reliably. Became.

In the embodiment of the present invention, the same effect can be obtained by using, for example, a photocoupler or a Hall element as the detecting means for detecting the wearing state of the developing device.

〔The invention's effect〕

As described above, when the developing device is not mounted at a predetermined position, the transfer paper can be reliably separated with a simple configuration in which the transfer charger and the separation charger do not discharge. Became.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an embodiment of the present invention. 10 ... Photoconductor, 11 ... Primary charger 12 ... Image exposure, 13 ... Developing device 14 ... Transfer guide, 15 ... Transfer charger 16 ... Separation charger, 17 ... Transfer paper 18 ... Cleaning device 41 ...... Connector pin 42 ...... Connector socket 43 ...... High voltage generator

Claims (1)

[Claims] 1. An image forming apparatus comprising a sheet separating device for separating a sheet from a toner image after the toner image developed on the image bearing member by a detachable developing means is transferred onto the sheet. A transfer charging unit that transfers an image onto a sheet, a separation charging unit that separates the sheet from the image carrier, a power supply that supplies power to the transfer charging unit and the separation charging unit,
A detecting unit that detects whether the developing unit is mounted at a predetermined position, and the transfer charging by the power source when the detecting unit detects that the developing unit is not mounted at the predetermined position. An image forming apparatus, which discharges a toner-free sheet without supplying electric power to the means and the separate charging means.