JP2538376Y2 - Belt drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a flat belt driving device, and more particularly to a belt driving device such as a photoreceptor belt and a transfer conveyance belt of an apparatus using an electrophotographic system. .

2. Description of the Related Art Conventionally, for example, in an electrophotographic apparatus, a photoreceptor layer or a dielectric layer is formed on a surface of a plurality of roller members arranged substantially in parallel with each other for the purpose of reducing the weight and size of the apparatus. It is known that a flat belt is stretched over, and the flat belt is used as a photosensitive belt or a transfer conveyance belt instead of the photosensitive drum.

However, flat belts used for such purposes are:
In many cases, the base material is formed of a material having low elongation and high strength, such as a plastic film or a metal foil. Therefore, since this type of flat belt is not easily elastically deformed, it absorbs dimensional errors of related parts, mounting errors of roller members, imbalance of belt tension, and uneven belt circumference by deformation of the belt itself. As a result, there is a problem that meandering is likely to occur when the flat belt runs.

However, such an electrophotographic apparatus requires high precision and high resolution in order to form an accurate image.
It is necessary to detect the meandering of the flat belt and eliminate it.

As a conventional technique for detecting such belt meandering and eliminating it, a complicated mechanism structure as disclosed in JP-A-58-110609 and JP-A-64-48457 is disclosed. Is used to detect and correct meandering.

(Problems to be solved by the invention) However, in the above-mentioned publication, in order to detect and correct meandering using a complicated mechanism,
Not only is it expensive and requires extra space, which not only leads to an increase in the size of the entire device, but also the number of parts due to the complicated mechanism and the number of parts that cause failures increases, and the reliability of the device is sufficient. It was hard to say that it was secured.

The present invention has been made in view of these points, and it is possible to detect the meandering of the belt at a low cost with a simple mechanism without performing complicated processing on the roller member and the flat belt, with a simple mechanism. It is an object of the present invention to provide a meandering detection device that can perform the meandering.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, when a meandering occurs in the flat belt, a meandering detecting member that comes into contact with the flat belt due to the meandering displacement is provided. The meandering correction is performed by using the torque acting on the wobble.
Specifically, the invention according to claim (1) includes a flat belt, a support shaft, and a roller, wherein the flat belt is provided with a plurality of roller members that are stretched so as to run, At least one of the roller members is configured as a meandering adjustment roller member. A meandering detection member disposed coaxially with the meandering adjustment roller member and supported rotatably independently of the meandering adjustment roller member is provided at at least one spindle end of the meandering adjustment roller member. The meandering detection member is provided with a meandering detection surface capable of contacting the edge of the meandering flat belt, and the meandering detection surface is formed substantially perpendicular to the meandering direction of the flat belt. When the meandering flat belt is connected to the meandering detection member and comes into contact with the meandering detection surface of the meandering detection member, the rotational torque is applied to the meandering detection member by the frictional force between the edge of the flat belt and the meandering detection surface. When actuated, there is provided a roller end displacement means for converting the rotational movement of the meandering detection member into a movement for displacing the shaft end of the meandering adjusting roller in a direction in which the meandering amount of the flat belt decreases.

In the invention according to claim (2), the flat belt is made of a belt material having high rigidity in the width direction.

In the invention according to claim (3), the flat belt is provided with a metal foil as a tension band whose width direction coincides with the belt width direction.

According to a fourth aspect of the present invention, the flat belt includes a polymer composite material in which a large number of needles extending substantially in the belt width direction are embedded.

(Operation) Next, the operation of the present invention with the above configuration will be described.

According to the invention described in claim (1), when the flat belt is displaced by meandering and its edge contacts the meandering detecting surface of the meandering detecting member, the rotational torque is applied to the meandering detecting member by the frictional force between the two. Acts, and the meandering detection member rotates according to the rotation torque. Then, the roller end displacement means converts the rotational movement of the meandering detection member into a movement in which the shaft end of the meandering adjustment roller is displaced in a predetermined direction. As a result, the flat belt is moved in a direction in which the meandering amount decreases. Since the device performs such a meandering correction operation, the meandering correction is reliably performed. Further, even if the meandering correction operation is not performed well and the meandering amount becomes large, the meandering detection surface of the meandering detection member is formed substantially perpendicular to the meandering direction of the flat belt. Therefore, an increase in the meandering amount can be forcibly prevented. Further, since the meandering detection surface is formed substantially perpendicular to the meandering direction of the flat belt as described above, the wear direction due to the contact of the flat belt when used for a long period of time can be adjusted to the meandering detection surface. Since the direction is perpendicular to the direction, the amount of change in the meandering detection position with respect to the amount of wear is small, and the meandering detection operation is performed smoothly for a long period of time.

According to the invention described in claim (2), the flat belt is made of a belt material having high rigidity in the width direction.
When the flat belt comes into contact with the meandering detection member, it is possible to suppress the occurrence of buckling deformation or damage at the belt end.

According to the invention described in claims (3) and (4), means for improving the rigidity of the flat belt in the width direction can be embodied,
Power can be reliably transmitted to the meandering detection member.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a flat belt driving device housed in an electrophotographic apparatus according to the present invention. In FIG. 1 which shows the entire driving device for a three-axis photoreceptor belt, reference numerals 1, 2, and 3 denote first, second and third roller members, respectively.
a, 2a, 3a, and elastic rollers 1b, 2b formed to have a slightly larger diameter concentrically with the support shafts 1a, 2a, 3a except for the left and right ends of the support shafts 1a, 2a, 3a. , 3b. As a material for the elastic rollers 1b, 2b, 3b, for example, EPDM-based crosslinked rubber is employed. However, the rollers 1b, 2b, 3b need not be elastic.

Further, a photoreceptor belt 4 as a flat belt according to the present invention, in which a photoreceptor layer is formed on the surface of a base material, is runably stretched over each of the roller members 1, 2, and 3. The photoconductor belt 4 functions as a photoconductor of the electrophotographic apparatus. A nickel foil 17 is used as a base material of the photoreceptor belt 4.

The first roller member 1 has a support shaft 1a linked to the drive shaft of the drive motor 5 so that the drive force of the drive motor 5 can be transmitted, and functions as a so-called drive roller.

The second roller member 2 is a so-called driven roller, and its axis is inclined with respect to the axis of the first roller member 1.
For example, only the end in the direction A of the support shaft 2a is slightly moved in the direction C with respect to the horizontal position with respect to the first roller member 1 (for example, 1 m).
m) Displaced.

The third roller member 3 is a meandering detection roller member according to the present invention, and its axis is arranged substantially parallel to the axis of the first roller member 1. The third roller member 3 is provided with a biasing force in the C direction by springs 3c, 3c disposed at both left and right shaft ends, and the tension of the photosensitive belt 4 is adjusted by the biasing force. It has become.

Since the roller members 1, 2, and 3 are provided in this manner, the photosensitive belt 4 stretched over the roller members 1, 2, and 3 always meanders in the A direction. It has become.

The shaft end of the support shaft 3a of the third roller member 3 is rotatably supported by a lower frame 8a via a bush 7 as a bearing member, as shown in FIGS. A frame 8a is engaged with an upper frame 8b attached and fixed to the movable member 6 via a slide bearing 9 so as to be able to approach and separate from the shaft end of the first roller member 1.

Further, the meandering detecting member 11 is provided at a position inside the mounting position of the lower frame 8a of the support shaft 3a of the third roller member 3 with the third roller member 3.
And is rotatably disposed independently of the third roller member 3. Further, a ring member 12 is mounted at a position outside the meandering detection member 11.

The meandering detection member 11 is formed of polyacetal or the like. The meandering detection member 11 has a disk formed on a meandering detection surface 11a in which the surface facing the side end surface 4a of the elastic roller 3b is formed perpendicular to the extending direction of the third roller member 3. When the meandering occurs in the photosensitive belt 4, the meandering displacement causes the side end surface 4a of the photosensitive belt 4 to contact the meandering detection surface 11a.

The meandering detection member 11 has one end connected to the winding portion 11b and the other end of the cord member 13 fixed to the fixing member S. The meandering displacement of the photosensitive belt 4 causes the photosensitive belt 4 to move.
Is in contact with the meandering detection surface 11a of the meandering detection member 11, and when a rotational torque acts on the meandering detection member 11, the rotation of the meandering detection member 11 causes the string member 13 to wind up the winding portion 11b of the meandering detection member 11.
The shaft end of the support shaft 3a of the third roller member 3 is displaced in the direction of FIG. 1B. That is, when the shaft end of the support shaft 3a is displaced in the direction B, the photosensitive belt 4 travels while being wound in the direction opposite to the direction A. Is the axis 3a until the reverse meandering component occurs and cancels with the initial meandering component.
Will be displaced.

As shown in FIG. 4, a spring 15 is connected to the ring member 12 at the shaft end of the support shaft 3a, so that the ring member 12 is always urged in the direction opposite to the direction of displacement by the winding operation of the string member 13. The displacement of the shaft end of the support shaft 3a by a predetermined amount or more is suppressed by the spring 15. With such a configuration, when the meandering component in the reverse direction due to the displacement of the shaft end of the support shaft 3a becomes larger than the initial meandering component, the photosensitive belt 4 starts meandering in the reverse direction, and the amount of riding on the meandering detection member 11 is increased. Therefore, the rotational torque of the meandering detection member 11 also decreases, and as a result, the amount of displacement of the shaft end of the support shaft 3a by the spring 15 also decreases.

Further, the movement of the meandering detection member 11 to the outside of the roller end is restricted by the stopper 16.

As the operation according to the above configuration, the photosensitive belt 4 is always displaced in the meandering direction in the direction A when the photosensitive belt 4 travels due to the inclined arrangement of the second roller member 2 with respect to the first and third roller members 1 and 3. doing.

The meandering displacement of the photoreceptor belt 4 causes the side end surface 4 a of the photoreceptor belt 4 to move to the meandering detection surface 11 of the meandering detection member 11.
a, the photosensitive belt 4 as shown in FIG.
The meandering detecting member 11 is rotated by the frictional force acting between the meandering detecting surface 11a of the meandering detecting member 11 and the string member 13 is wound by the rotation.

Due to the winding of the string member 13, the shaft end of the support shaft 3a, which is the end of the third roller member 3 on which the meandering detection member 11 is disposed, is displaced in the B direction. The displacement in the A direction is controlled. At the same time, the spring 15 is extended due to the displacement of the shaft end, and the spring force is also acting. Therefore, the displacement of the third roller member 3 is determined by the balance between the winding force of the string member 13 and the spring force of the spring 15. Is regulated, and the position of the edge of the photosensitive belt 4 is maintained at a certain fixed position.

Since the photosensitive belt 4 runs as described above, the meandering of the photosensitive belt 4 is eliminated, and the meandering amount of the photosensitive belt 4 can be suppressed to, for example, more than 10 μm.

When such an operation is performed for a long time, the meandering detection surface 11 of the meandering detecting member 11
a wears out. However, since the direction of the wear is perpendicular to the meandering detection surface 11a, the amount of change in the meandering detection position with respect to the amount of wear is suppressed, and the meandering detection operation is performed smoothly. That is, as shown in FIG. 6 (a), when the meandering detecting surface 11a is formed by the inclined surface, the change amount of the meandering detecting position relative wear amount s is as large as t _1. However, in the case of this example, as shown in FIG.
Variation of the meandering detection position for similar amount of wear s has a wear amount s substantially matching t _2. That is, the amount of change in the meandering detection position with respect to the amount of wear can be significantly reduced.

Further, according to such a shape of the meandering detection surface 11a, the side end surface 4a of the photoreceptor belt 4 can be further prevented from meandering from the state in contact with the meandering detection surface 11a, and the maximum amount of meandering displacement can be set. Can be.

As a modified example of the present embodiment, it is conceivable to secure a frictional force when the photosensitive belt 4 is in contact by forming fine irregularities on the meandering detection surface 11a.

Although the nickel foil 17 is used as the tension band of the photoreceptor belt 4 in the above-described embodiment, a metal foil such as a stainless steel foil or an aramid film may be used. The base of the photoreceptor belt 4 is made of a polymer composite material, and a large number of needles made of short fibers or the like are embedded in the belt in the width direction. It is also possible to adopt a configuration that enhances it.

Further, two or more meandering detection roller members provided with the meandering detection member 11 may be provided. Further, in this example, the second
By slightly displacing the shaft end of the roller member 2 in the direction C, the photosensitive belt 4 is made to meander in the direction A in advance, but the second roller member 2 is moved in parallel with the first roller member 1. The photosensitive belt 4 may be similarly meandered by disposing and displacing the shaft end of the third roller member 3.

In this embodiment, an example in which the present invention is applied to a photoreceptor belt driving device of an electrophotographic apparatus is described. However, the present invention is not limited to this, and a driving device of a transfer / transport device or a normal flat belt driving device is used. Can be similarly applied.

(Effects of the Invention) As described above, according to the present invention, the following effects are exhibited.

According to the first aspect of the present invention, the meandering flat belt can contact the end of the support shaft of the meandering adjusting roller member, and extends in a direction substantially perpendicular to the meandering direction of the flat belt. The reliability of the meandering correcting operation can be improved by providing the detecting member and performing the meandering correcting operation by using the rotational torque of the meandering detecting member acting by the contact of the flat belt. Further, even if the meandering correction operation is not performed well and the meandering amount becomes large, the meandering detection surface of the meandering detection member is formed substantially perpendicular to the meandering direction of the flat belt. Therefore, an increase in the meandering amount can be forcibly prevented. As described above, it is possible to obtain a device that detects and corrects belt meandering at a low cost with a simple mechanism and a small required space without performing complicated processing on the roller member and the flat belt. In addition, the meandering detection member has a wear direction due to contact with the flat belt when used for a long period of time, which is perpendicular to the meandering detection surface, so that the amount of change in the meandering detection position with respect to the wear amount is suppressed. Thus, the meandering detection operation is performed smoothly.

According to the invention described in claim (2), the flat belt is made of a belt material having high rigidity in the width direction.
When the flat belt comes into contact with the meandering detection member, buckling deformation and damage of the belt end can be suppressed.

According to the invention described in claims (3) and (4), means for improving the rigidity of the flat belt in the width direction can be embodied,
Power can be reliably transmitted to the meandering detection member.

[Brief description of the drawings]

1 to 6 show an embodiment of the present invention. FIG. 1 is a schematic perspective view of a belt driving device having a meandering detection device.
FIG. 3 is a vertical sectional front view around the meandering detection member, FIG. 3 is a perspective view seen from the inside, FIG. 4 is a perspective view seen from the outside, FIG. FIG. 6 is a diagram for comparing the change amount of the meandering detection position with respect to the wear amount of the meandering detection surface with the case where the detection surface is inclined. DESCRIPTION OF SYMBOLS 1 ... 1st roller member 2 ... 2nd roller member 3 ... 3rd roller member (meander detection roller member) 1a, 2a, 3a ... Support shaft 1b, 2b, 3b ... Elastic roller 4 ... Photoreceptor belt (flat belt) 11: meandering detection member 11a: meandering detection surface

Claims (4)

(57) [Scope of request for utility model registration] 1. A flat belt, comprising: a support shaft and rollers; and a plurality of roller members over which the flat belt is runnable, wherein at least one of the roller members is meandering. The meandering adjustment roller member is configured to be coaxial with the meandering adjustment roller member at at least one spindle end of the meandering adjustment roller member, and is independent of the meandering adjustment roller member. And a meandering detection member rotatably supported, the meandering detection member has a meandering detection surface capable of contacting the edge of the meandering flat belt, and the meandering detection surface is arranged in the meandering direction of the flat belt. When the meandering flat belt is connected to the meandering detection member and comes into contact with the meandering detection surface of the meandering detection member, the meandering force is generated by the frictional force between the edge of the flat belt and the meandering detection surface. Rotational torque acts on the detection member Then, there is provided a roller end displacement means for converting the rotational movement of the meandering detection member into a movement for displacing the shaft end of the meandering adjusting roller in a direction in which the meandering amount of the flat belt decreases. Characteristic belt drive. 2. The belt driving device according to claim 1, wherein the flat belt is made of a belt material having high rigidity in a width direction. 3. The utility model registration claim (1) or (2), wherein the flat belt is provided with a metal foil as a tension band whose width direction coincides with the belt width direction. The belt driving device according to the item 2). 4. A utility model registration according to claim 1, wherein the flat belt is provided with a polymer composite material in which a large number of needles extending substantially in the belt width direction are embedded.
Item or the belt drive device according to item (2).