JPS58212540A - Carrying roller of endless belt type recording body - Google Patents

Abstract

PURPOSE:To improve the duration of life of a recording body while removing a stripping phenomenon by preventing the fatigue of the recording body caused by its repeated folding formed due to a roller end by beveling the carrying roller end of the endless belt type recording body with a proper radius of curvature. CONSTITUTION:Corner parts along the both end surfaces of outer periphery of carrying roller 2 having near its both ends contact pieces 3 for detecting the approach of an endless belt type recording body 1 are beveled with a proper radius of curvature. Accordingly, when the belt type recording body 1 is driven while applying tension to it, portions of the recording body 1 wound round the carrying roller 2 are bent at roller end parts, and each of these bent parts is inflected with a certain radius of curvature along the curvature of the outer periphery of end part 2a of the roller 2. Therefore, the local concentration of bending stress is avoided, enabling the occurrence of the stripping of the recording body 1 from its side end parts to be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conveyance roller of a recording apparatus in which an endless belt-like recording medium is supported and guided by a plurality of conveyance rollers and driven in the circumferential direction.

For example, in electrostatic recording type electrophotographic devices, an endless belt-like recording medium (
A configuration is adopted in which the photoreceptor is supported by a plurality of conveyance rollers and driven in the circumferential direction.

By the way, when such an endless belt-shaped recording medium is rotated, the belt shifts to either the left or right side as time passes due to the accuracy of the belt, the accuracy of the device, local friction, etc. If you continue to use this without correcting it, not only will the recording device on the belt become misaligned, but it will also impede belt drive and damage both sides of the belt, so it is necessary to detect this misalignment and correct it. be.

As shown in FIG. 1, contact pieces 3 are provided near both ends of one of the conveying rollers 2 that wind and support the belt-like recording material 1, as a correction means for detecting deviation of the endless belt-like recording material.
is swingably provided on the shaft 4, and a contact portion 3a provided at one end thereof.
is brought into contact with the side edge 1a of the belt-shaped recording medium 1, and if the deviation of the recording medium l exceeds a predetermined amount, the light shielding piece 3 at the other end of the contact piece 3
b, the shift interrupter 5 is turned on and off, and the signal causes a slight displacement of one side of the conveying roller in a direction perpendicular to the belt surface, for example, by a solenoid, thereby twisting the belt slightly. Generally used are devices that automatically correct misalignment by shifting the image in the lateral direction.

In the above-mentioned system for detecting deviation of a belt-shaped recording medium, the contact portion 3a contacts the side edge 1a of the recording medium 1, but needs to be arranged so that it does not contact the end surface 2a of the conveying roller 2. Therefore, the side edge 1a of the recording medium 1 protrudes outward from the end surface 2a of the conveyance roller 2.

When the belt-shaped recording material is driven in this state while applying tension, the recording material 1 is bent to form a corner at a position where it contacts the outer periphery of the end surface 2a of the conveyance roller 2, as shown in FIG. Since this occurs only in the portion wound around the conveyance roller 2, the bent portion moves with the rotation of the belt-shaped recording material, and as a result, repeated bending stress acts on the recording material.
Fatigue is added to the record.

If the recording medium is made of a uniform material, the effect of fatigue described above will not be as great as on the left. In the case of a belt-shaped recording medium such as a belt-shaped photoreceptor, which is constructed by laminating several layers of different materials, peeling occurs at the boundary surface of each layer at the part that touches the end of the conveyance roller, and peeling occurs from the side edge to the other layer. As a result, it loses its function as a recording medium.

The present invention provides a structure for a conveying roller that prevents fatigue caused by the above-mentioned repeated bending of an endless belt-like recording medium by the ends of the conveying roller, thereby eliminating the peeling phenomenon of the recording medium and contributing to improving the life of the recording medium. The purpose is to provide.

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments thereof.

In the embodiment shown in FIG.
Conveyance roller 2 with contact pieces 3 for detecting misalignment provided near both ends
The corners of the outer periphery of both end faces are chamfered with an appropriate curvature.

Note that 6 is a bearing, and 7 is a tension spring.

Therefore, when the belt-shaped recording material l is driven while applying tension, the recording material bends as shown in FIG. Since it is bent with a certain curvature along the curvature of the outer periphery of the end surface 2a, local concentration of bending stress is avoided, and as a result, the occurrence of peeling of the recording material from the side edges is prevented.

In another embodiment shown in FIG.
The surface layer 2b in contact with is made of an elastic material such as rubber, sponge, or felt. Therefore, when the belt-shaped recording material l is driven while applying tension, the portion of the end of the conveyance roller 2 around which the recording material l is wound is pressed by the tension of the recording material, but is deformed by the elasticity of the surface layer 2b. , concentration of bending stress on the recording medium is prevented. Note that the surface layer of the elastic body does not necessarily have to be provided over the entire length of the conveyance roller 2, but the purpose can be achieved by providing it only at appropriate lengths at both ends.

In yet another embodiment shown in FIG. 6, an annular elastic body 2c is provided at the end of the transport port 2. As shown in FIG. Its outer diameter is slightly larger than the outer diameter of the conveyance roller 2, and the angle of the outer periphery of the end surface opposite to the surface in contact with the conveyance roller main body 2 is chamfered with an appropriate curvature.

Therefore, when the belt-shaped recording medium 1 is driven while applying tension, the portion of the annular elastic body 2c in contact with the recording medium is curved and becomes approximately the same radius as the circumferential surface of the conveying roller main body 2, and the end surface thereof The fact that the corners of the annular surface 2c of the recording medium are curved and elastically abuts against the recording medium makes it even more effective in preventing the concentration of bending stress at the corners of the annular surface portion 2c of the recording medium. become certain.

As described above, according to the present invention, it is possible to avoid local concentration of bending stress at the portion of the end of the recording medium that abuts the corner of the end surface of the conveyance roller, and as a result, especially when the recording medium has layers of different phases. Even when the recording medium is formed by laminating layers, delamination does not occur and the life of the recording medium can be improved.

By chamfering the outer periphery of the end surface of the conveying roller with a suitable curved tail, another effect can be obtained in that the endless belt-like recording medium can be easily inserted when attached to the conveying roller.

The above embodiments have been described using a latent image recording body (photoreceptor) of an electrophotographic copying machine using an electrostatic recording method as an example. The present invention can also be applied to a conveyor belt for an endless belt-like recording medium in a system.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the vicinity of the end of a conventional conveying roller in which a shift detection means for a conventional endless belt-shaped recording medium is provided near the end, and FIG. 3 is a sectional view showing an embodiment of the present invention, FIG. 4 is a sectional view showing the bent state of the end of the recording medium when the recording medium is driven in the apparatus, and FIG. 5 is a sectional view showing the bending state. FIG. 6 is a sectional view showing still another embodiment of the present invention.
Il... Endless belt-shaped recording body 2... Conveying rollers 2b, 2C... Elastic body part 3... Recording body deviation detection means Fig. 1 Fig. 2

Claims (1)

[Scope of Claims] (11) An endless belt-shaped recording medium is supported and guided by a plurality of conveying rollers and driven in the circumferential direction, and a contact type recording body deviation detection means is provided as described above to correct deviation of the recording medium in the width direction. In the above-mentioned conveyance roller shorter than the recording body width of the recording device, which is disposed near one end of the conveyance roller and has a length of the conveyance roller slightly shorter than the width of the recording body, the endless belt-shaped recording body It is characterized by having a means for preventing the end of the portion of the recording medium wrapped around the conveyance 4 voice 2 from being bent at a corner position of the outer periphery of the end surface of the conveyance roller. Conveying roller. (2) As a means for preventing bending of the endless belt-like recording medium, the outer circumferential corner of the conveying roller is chamfered with an appropriate curvature. (3) As a means for preventing bending of one endless belt-like recording medium, at least the end portion of the surface of the conveyance roller that comes into contact with the recording medium is made of an elastic material. The conveyance loaf according to scope 1 (4) The scope of claims characterized in that the corners of the outer periphery of the end surface of the elastic body provided on at least the end surface of the conveyance roller are chamfered with an appropriate curvature. The conveying roller according to item 3. (5) At least one or more layers of different materials are laminated on the surface of the flexible member layer forming the base of the endless belt-shaped recording body supported by the conveying roller. The conveyance roller according to any one of claims 1 to 4, characterized in that the conveyance roller is made of a.