JPH04216576A - Transfer device - Google Patents

Abstract

PURPOSE:To surely transfer a toner image even to the trailing edge of a body to be transferred without irregularity by providing a wind force pressing means for pressing the body to be transferred to an image carrier by wind force. CONSTITUTION:When a transfer paper 31 arrives at the transfer position of the toner image, an air blowing fan 22 is actuated and the transfer paper 31 is pressed by the wind force to tightly contact with a photosensitive drum 11. By impressing bias voltage of reverse polarity to the toner on the transfer wire 19 of a transfer device 17, the toner image formed on the photosensitive drum is transferred to the transfer paper 31. Even after the transfer paper 31 is fed further and the trailing edge thereof passes a transfer roller 13, the transfer paper 31 is pressed by the wind force and tightly contacts with the drum 11, so that deviation is not caused between the drum 11 and the transfer paper 31.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applied to, for example, electrophotographic copying machines and page printers, and is a transfer device that transfers a toner image from an image carrier such as a photoreceptor drum to a transfer object such as transfer paper. It is related to.

0002

2. Description of the Related Art In an electrophotographic apparatus such as a copying machine, for example, as shown in FIG. A transfer device 43 to which polar bias voltages are applied is provided. Further, guide rollers 44, guide members 45, etc. are provided on the upstream and downstream sides of the transfer device 43 in the conveyance path of the transfer object 42, and the guide rollers 44, guide members 45, etc. are provided to press the transfer object 42 against the photoreceptor drum 41 and bring it into close contact with the photoreceptor drum 41. This prevents image disturbance caused by relative misalignment between the photosensitive drum 41 and the transfer target 42.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional transfer device, the elasticity of the transferred body 42 is utilized to
Since the transfer object 42 is pressed against the photoreceptor drum 41, the rear end of the transfer object 42 is pressed against the guide roller 4.
After passing through a position such as No. 4, the force that presses the transfer object 42 against the photoreceptor drum 41 hardly acts.

For this reason, there has been a problem in that the image tends to be distorted, especially near the edges of the transfer target 42. In view of the above-mentioned points, it is an object of the present invention to provide a transfer device that can transfer a toner image without disturbing the image by bringing a transfer object into close contact with a photoreceptor drum or the like.

[0005]

Means for Solving the Problems In order to achieve the above object, the present invention provides a transfer device that transfers a toner image formed on an image carrier onto a transfer target, in which the transfer target is transferred to an image carrier using wind power. It is characterized by being equipped with wind pressure means for pressing against the body.

[0006]

[Operation] According to the above structure, the object to be transferred is pressed against the image carrier by the wind force of the wind force pressing means.

[0007]

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a front view showing the configuration of main parts of an electrophotographic apparatus to which a transfer device according to the present invention is applied. The photosensitive drum 11 is, for example, a conductive body on which a photosensitive conductive layer is formed, and a toner image is formed by exposure by an exposure device (not shown) and development by a developing device. .

Below the photosensitive drum 11, there are a pair of registration rollers 12, a transfer roller 13, which conveys or guides a transfer paper 31 fed from a paper feed tray (not shown).
A guide member 14 and paper guides 15 and 16 are provided. Further, a transfer device 17 is provided below the photosensitive drum 11 in the vicinity between the transfer roller 13 and the guide member 14 . The transfer device 17 includes a frame 18 and a transfer wire 19 to which a bias voltage having a polarity opposite to that of the toner is applied.

A ventilation hole 18a is formed in the frame 18 of the transfer device 17, and a ventilation fan 22 is connected to the ventilation hole 18a via a duct 21. In the above configuration, the photoreceptor drum 11 is exposed to light by an exposure device,
Then, development is performed by a developing device to form a toner image. On the other hand, the transfer paper 31 is supplied via the registration roller pair 12 at a predetermined timing, and is fed to the paper guide 15.
, and the transfer roller 13, and is transported between the photosensitive drum 11 and the transfer device 17, that is, to the toner image transfer position.

When the transfer paper 31 reaches the toner image transfer position, the blower fan 22 is activated, and the transfer paper 31 is pressed by the wind force and comes into close contact with the photosensitive drum 11. Therefore, transfer device 1
When a bias voltage having a polarity opposite to that of the toner is applied to the transfer wire 19 of No. 7, the toner image formed on the photosensitive drum is transferred to the transfer paper 31. Even after the transfer paper 31 is further conveyed and the rear end passes the position of the transfer roller 13, the transfer paper 31 is still pressed by the wind force and comes into close contact with the photoreceptor drum 11, and the photoreceptor drum 11 and the transfer paper There will be no deviation between 31 and 31.

Therefore, the toner image is reliably transferred to the rear end of the transfer paper 31 without any disturbance. In addition,
The transfer paper 31 is transferred to the photosensitive drum 1 by wind force as described above.
1, the transfer roller 13 and guide member 14 may be eliminated to simplify the configuration.

Further, in this embodiment, an example of the transfer device 17 for transferring a toner image from the photoreceptor drum 11 to the transfer paper 31 is shown, but the present invention is not limited to this. The resulting toner image is further transferred to the transfer paper 31.
It may also be applied to a transfer device that transfers images.

[0013]

[Effects of the Invention] As explained above, according to the present invention,
By being equipped with a wind pressure means that presses the transferred object against the image carrier using wind force, the transferred object is firmly attached to the image carrier, so that the toner image is transferred all the way to the rear end of the transferred object. This has the effect that the transfer can be performed reliably without any disturbance.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the configuration of essential parts of an electrophotographic apparatus as an embodiment of the present invention.

FIG. 2 is a front view showing the configuration of main parts of a conventional electrophotographic apparatus.

[Explanation of symbols]

11 Photosensitive drum 17 Transfer device 21 Duct 22　　　　Blower fan

Claims (1)

[Claims] 1. A transfer device for transferring a toner image formed on an image carrier onto an image carrier, characterized by comprising a wind pressure means for pressing the image carrier against the image carrier using wind force. Transfer device.