JPS595252A - Transfer paper guide device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To smoothly guide transfer paper even if the paper thickness varies, and to enhance image quality of a copy, by fixing one end of an elastic member for guiding the paper to one of upper and lower guide plates, and bringing the other end into contact with the forward end of the other guide plate. CONSTITUTION:One end of an elastic member 4 for guiding the transfer paper is fixed to the upper guide plate 2 and the other end is held in contact with the forward end of the lower guide plate 3. The transfer paper P travels forward in the arrow direction while releasing the contact between the member 4 and the plate 3. The end of the paper P is guided along the end of the plate 3 by the pressing force of the member 4, and arrives at the prescribed transfer point of a photoreceptor 1 without colliding against it. Since the forward end of the paper P is corrected in the direction, and contacts with the photoreceptor 1, stains on the reverse side of the paper and deficiency of transfer are prevented even if thickness of the paper P varies.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer paper guide device in an electrophotographic copying machine or the like.

Generally, in an electrophotographic copying machine, a toner image formed on a photosensitive drum in a developing section is transferred to a transfer paper by a transfer charging device in a transfer section. A transfer paper guide device that supplies the transfer paper to the transfer section is provided to perform this transfer process, but the conventional transfer paper guide device moves the transfer paper between the photoreceptor drum (1) as shown in Figure 1. It has an upper guide plate (2) and a lower guide plate (3) for upward guidance. However, the spacing between the upper and lower guide plates is adjusted to suit standard paper such as plain paper (basis weight 50-65K?). Driving becomes difficult. In addition, if the distance between the upper and lower guide plates is increased in order to make the cardboard run smoothly, when plain paper, etc. is fed, the leading edge of the fed paper will come into contact with the toner image on the photosensitive drum, causing the leading edge of the transfer paper to move smoothly. Toner contamination on the back side and transferred images! ii) An inconvenience occurs that causes temporary deterioration.

The present invention has been made to eliminate the above-mentioned drawbacks of conventional transfer paper guiding devices, and its purpose is to always guide the transfer paper smoothly even when the thickness of the transfer paper varies. To provide a transfer paper guide device that allows copies of excellent image quality to be obtained.

The above object of the present invention is achieved by providing an elastic member on either side of the upper and lower guide plates of the transfer paper guide device to guide the transfer paper along the tip of the guide plate. The present invention will be described in detail. In Figure 2, one end of a transfer paper guiding elastic member (4) is attached to the upper guide plate (2), and the other end of the elastic member (4) is in contact with the tip of the lower guide plate (3). The transfer paper moves in the direction of the arrow while releasing contact between the PU elastic member (4) and the lower guide plate (3). The leading edge of the transfer paper P is guided along the leading edge of the lower guide plate by the pressure of the elastic member (4), so that it reaches the transfer point A at constant Qr without colliding with the photosensitive drum, and satisfactory transfer is performed. The elastic member for guiding the transfer paper is a flexible thin plate-like member, and has enough elasticity to guide the tip of the transfer paper along the tips h1~ of the upper (lower) guide plates (2, 3). For example, it can be formed of metal foil, plastic film, or a rectangular VC curved wire.

According to the present invention, it has been found that Mylar (part name, manufactured by 6M Company) made of polyester film is preferable.

Fig. 6 shows an embodiment in which the elastic member (4) for guiding the transfer paper is attached to the lower guide plate (3), and in this case, the tip of the upper guide plate is directed slightly downward. It is better.

According to the transfer paper guide device of the present invention, the interval between the upper and lower guide plates,
Depending on the type of transfer paper, the running condition in one device will change, but the elastic member corrects the direction of the leading edge of the transfer paper so that the leading edge of a given transfer paper always comes into contact with the photosensitive drum. No contamination or transfer defects will occur.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an outline of a transfer paper guide device in a conventional electrophotographic copying machine, and FIGS. 2 and 3 are diagrams each showing an embodiment of an uninvented transfer paper guide device. Symbols in the figure = 1...Photosensitive drum, 2...Upper guide plate. 6... Lower guide plate, 4... Elastic member for guiding transfer paper. 1st 2nd farming = and ＼P

Claims (1)

[Claims] One end of the elastic member for guiding the transfer paper is attached to either the upper guide plate or the lower guide plate that guides the transfer paper onto the photoreceptor drum, and the other end is brought into contact with the tip of the lower guide plate or the upper guide plate. A transfer paper guide device for an electrophotographic copying machine, characterized in that: