JPH0192143A - Belt device - Google Patents

Abstract

PURPOSE:To improve a running property and durability by obliquely forming the end parts in the width direction of each of width-direction position restricting projecting parts provided on the back face of a belt. CONSTITUTION:Width-direction position restricting projecting parts 16, 16 are provided on both end parts in the width direction on the back face of a belt 3 along the circumferential direction. Each projecting part 16 both end parts of which in the width direction are formed in a taper shape forms an engaging part on the inner side in the radial direction of the outer peripheral surface of a driving roller 1 being separably engaged with end faces 1a, 1b. In this structure, when a belt 3 is made run by means of a driving roller 1, if the distance between shafts on the left end part of both rollers 1, 2 is larger than the distance between shafts on the right end part, the projecting part 16 on the left side is separated from the left end faces 1b, 2b of the rollers 1, 2 and rides over the outer peripheral surface, while stopping the movement at the time when both right and left distances between shafts becomes the same.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a belt device that is built into an electrophotographic copying machine, a laser printer, or the like and includes a belt made of a photoreceptor, a dielectric material, or the like.

[Conventional technology]

2. Description of the Related Art Electrophotographic copying machines and laser printers using photoreceptor belts or dielectric belts have been considered for some time.

That is, as shown in FIG. 4, in the above-mentioned electrophotographic copying machine or laser printer, a belt 3 made of a photoreceptor or dielectric material is stretched between a drive roller 1 and an idle roller 2. It is supported and cyclically conveyed in the direction of the arrow by the drive roller 1.

After the belt 3 is charged by a charger 4 placed opposite to the belt 3, exposure is performed in an exposure section 5, and a latent image is formed on the belt 3. Further, the latent image is made visible by toner supplied from a developer tank 6 disposed opposite to the belt 3, and subsequently, the visible image is transferred onto a sheet of paper (not shown) in a transfer section. The toner remaining on the belt 3 is removed by the cleaner 7, and the surface of the belt 3 is further neutralized by a static eliminator (not shown), so that the belt 3 completes one cycle.
goes around once.

By the way, in the above device, the charger 4, the exposure section 5,
It is necessary to prevent the belt 3 from waving or lifting at any location where the developer tank 6 and the cleaner 7 are provided. Therefore, a predetermined tension is applied to the belt 3 between the drive roller 1 and the idle roller 2, and the belt 3
Back plates 8 and 9 are installed on the back side.

In addition, as shown in FIG. 5, if the axes of the drive roller 1 and the idle roller 2 are not assembled in parallel, while the belt 3 is being conveyed, the belt 3 will move toward one side in the width direction as shown by the arrow. Specifically, it moves to the side where the distance between the axes of both ends and the rad 2 is smaller. Furthermore, if there is a difference in the circumferential length at both ends in the width direction of the belt 3, a pair of springs (shown in FIG. Even if the biasing forces of the belts (not shown) are different, the interaxial distance between the roller rods 2 will be different at both ends of the roller rod 2 in the axial direction, so that the belt 3 will move in the width direction. Such movement of the belt 3 in the width direction causes an adverse effect on the quality of the image to be copied or printed.

Therefore, conventionally, as shown in FIG. 6(a) or (b), a protrusion 10 is provided on the back surface of the belt 3 along its circumferential direction, and this protrusion 10 is attached to the drive roller 1 and the idle roller 2. By bringing it into contact with the end surface (FIG. 6(a)) or by fitting into the groove 11 formed at the axial end of the drive roller 1 and the idle roller 2 (FIG. 6(b)),
A belt device that regulates the position of the belt 3 in the width direction is revolving.

[Problem that the invention seeks to solve]

However, in the above-described belt device, when removing the belt 3 from the roller head 2, it is difficult to easily separate the protrusion 10 from the end surface of the roller head 2 or the groove 11, so there is a problem in that it takes time and effort to remove the belt 3. It had

Further, although the protrusion 10 is usually glued to the belt 3, if the distance between the shafts is not the same at both ends of the roller rod 2 in the axial direction, and a large lateral pressure is applied to the protrusion 10,
Since there is a risk that the protrusion 10 may come off the belt 3, there is a drawback in durability.

[Means for solving problems]

In order to solve the above problems, a belt device according to the present invention has a belt that is stretched between a plurality of rollers and is conveyed. Retaining parts are provided at inner positions, and retaining parts are provided at both widthwise ends of the back surface of the belt, the ends of which are formed in an inclined shape, and are removably engaged with the retaining parts of the rollers. a width direction position regulating protrusion to be fitted together; a supporting means for movably supporting both axial ends of the at least one roller in a direction in which tension is applied to the belt and in a direction opposite thereto; The present invention is characterized in that it includes a biasing means for biasing both axial ends in a direction to apply tension to the belt.

[For production]

According to the above configuration, the widthwise end of each widthwise position regulating protrusion is formed in an inclined shape, so if the distance between the axes does not match at both ends of the roller in the axial direction, the belt is , one of the widthwise position regulating protrusions, specifically, the widthwise position regulating protrusion on the side where the distance between the axes of the rollers is relatively large, is gradually separated from the retaining part of the corresponding roller. while moving in the width direction. As a result, the one widthwise position regulating protrusion is gradually exposed on the outer circumferential surface of the roller, so the tightening force of the belt against the roller gradually increases on the side of the one widthwise position regulating protrusion. As a result, the roller provided with the biasing means approaches the other roller on the side of the one width direction position regulating protrusion, resisting the biasing force of the biasing means, and as a result, the width of the one width direction is increased. The distance between the axes of the rollers decreases on the side of the directional position regulating protrusion.

Then, the belt stops moving in the width direction at a position where the distance between the axes at both ends of the roller in the axial direction becomes equal, and after that, the belt runs stably without moving in the width direction.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

The belt device built into the electrophotographic copying machine or laser printer according to this embodiment and equipped with a belt made of a photoreceptor or dielectric material basically has the same configuration as the conventional example shown in FIG. There is.

The support mechanism for the drive roller 1 and the idle roller 2 will be explained in detail below.As shown in FIG.
Both ends of the shaft 1a in the axial direction, that is, both left and right ends in the figure, are 1
It is supported by the pair of side plates 12, 12 so as to be rotatable, but not movable in the longitudinal direction.

On the other hand, both left and right end portions of the shaft 2a of the idle roller 2 are rotatably supported by a pair of tension plates 13 as supporting means disposed on the outside of each of the side plates 12. Each tension plate 13 is movable along with the shaft 2a in the longitudinal direction of the side plates 12, 12, that is, in the A and reverse A directions. A tension lever 14 is rotatably attached to each tension plate 13, and when each tension lever 14 is rotated in the B direction, the tension plate 13 is moved in the 'A force direction. Further, each tension plate 13 is rotated in a reverse direction by a tension spring 15 as a biasing means stretched between it and the side plate 12.
direction, that is, the direction in which tension is applied to the belt 3.

As shown in FIG. 1, at both ends in the width direction on the back side of the belt 3, that is, at both left and right ends in the figure, there are protrusions for regulating the width direction position (hereinafter simply "protrusions") along the circumferential direction of the belt 3. Section 16.16 is provided. Each protrusion 16
is formed in an inclined shape, more specifically in a tapered shape, at both ends in the width direction, and separates from the end surfaces 1b and 2b of the drive roller 1 or the idle roller 2 as a retaining portion located radially inward from the outer circumferential surface. Possibly engaged.

In the above configuration, when the belt 3 is conveyed by the driving roller 1, when the distance between the axes of the roller rad 2 is equal between both ends and the left and right ends of the rad 2, the belt 3 does not move in the width direction. Therefore, the protrusions 16 and 16 are both open and closed.
The belt 3 maintains its engagement with the end surfaces 1b and 2b, and the belt 3 runs stably in this state.

On the other hand, as shown in FIG. 5, for example, when the distance between the axes at the left end of the double-end-rad 2 is larger than the distance between the axes at the right end, the belt 3 will move as shown in FIG. is gradually separated from the left end surfaces 1b and 2b of the roller rod 2 and moved to the right in the figure. Along with this, the left protrusion 16 gradually rides on the outer circumferential surface of the rollerad 2, so that the tightening force on the rollerad 2 at the left end of the belt 3 is greater than the tightening force on the rollerad 2 at the right end of the belt 3. As a result, the left end of the idle roller 2 moves in a direction approaching the left end of the drive roller 1 against the biasing force of the left tension spring 15.

The movement of the left end of the idle roller 2 toward the drive roller 1 ends when the distance between the shafts at the left end and the distance between the shafts at the right end of the double-end-rad 2 match, and after that, the belt 3 runs stably without moving in the width direction. On the other hand, if the distance between the axes at the right end of the roller rod 2 is larger than the distance between the axes at the left end, the belt 3 moves leftward to a stable position.

Note that when removing the belt 3, each tension lever 14 is rotated in the direction B, and each tension plate 13 is removed.
At the same time, the tension on the belt 3 is released by moving the idle roller 2 in the direction A, and in this state, the belt 3 is removed from the left end side of the roller head 2. When attaching the belt 3, the operation described above may be performed in reverse.

In the above embodiment, both ends of each protrusion 16 in the width direction are formed into a tapered shape, but each protrusion 16 can also be formed with a semicircular cross section, in other words, each protrusion 16 It is sufficient that the width direction end portion of the protrusion portion 16 is formed in an inclined shape so that the protrusion portion 16 can be detached from the end face.

〔Effect of the invention〕

As described above, the belt device according to the present invention has a belt stretched between a plurality of rollers to be conveyed, and the belt device is provided at a position radially inward from the outer circumferential surface at both ends of the roller in the axial direction. A retaining part provided,
at least a widthwise position regulating protrusion provided at both widthwise ends of the back surface of the belt, the widthwise ends of which are formed in an inclined shape, and releasably engaged with the retaining portion of the roller; a support means that supports both axial ends of one roller so as to be movable in the direction of applying tension to the belt and in the opposite direction; and both ends of the at least one roller in the axial direction respectively in the direction of applying tension to the belt. This configuration includes a biasing means for biasing the battery.

As a result, since the widthwise end of each widthwise position regulating protrusion is formed in an inclined shape, the widthwise position regulating protrusion can be easily separated from the engagement part of the roller when the belt is removed. As a result, the belt can be easily removed from the roller.

In addition, if the distances between the rollers do not match at both ends in the axial direction of the plurality of rollers, the belt will
While gradually separating one width direction position regulating protrusion, that is, the width direction position regulating protrusion on the side where the distance between the axes of the rollers is relatively large, from the retaining part of the corresponding roller, By moving to , the distance between the axes at both ends of the roller in the axial direction is made to match, so that excessive lateral pressure is no longer applied to the protrusion for regulating the position in the width direction, and as a result, the widthwise direction from the belt is reduced. This also has the effect of reducing the possibility of the position regulating protrusion coming off and improving durability.

[Brief explanation of the drawing]

1 to 3 show embodiments of the present invention, in which FIG. 1 is a cross-sectional view of the roller section, FIG. 2 is a cross-sectional view showing movement of the belt in the width direction, and FIG. The figure is a perspective view, FIG. 4 is a schematic side view of an electrophotographic copying machine or laser printer using a photoreceptor or dielectric belt, FIG. 5 is a plan view showing movement of the belt in the width direction, and FIG. a) and (b)
) are cross-sectional views of the roller portion in the conventional example. 1 is a drive roller (roller), 2 is an idle roller (roller), 1b and 2b are end surfaces (retaining parts), 3 is a belt, 13
15 is a tension plate (supporting means), 15 is a tension spring (biasing means), and 16 is a widthwise position regulating projection. Figure 1 Figure 20 1a (2a)

Claims (1)

[Claims] 1. In a belt device having a belt stretched between a plurality of rollers and conveyed, engagements provided at positions radially inside the outer circumferential surface of the rollers at both ends in the axial direction. and a widthwise position regulating protrusion provided at both widthwise ends of the back surface of the belt, the widthwise ends of which are formed in an inclined shape, and releasably engaged with the engaging portion of the roller. and support means for movably supporting both axial ends of the at least one roller in the direction of applying tension to the belt and in the opposite direction, respectively, and supporting means for supporting both axial ends of the at least one roller to apply tension to the belt, respectively. A belt device comprising a biasing means for biasing in a direction of application.