JP2874117B2 - Belt running device - Google Patents

Description

The present invention is applicable to, for example, a photoreceptor belt traveling device in a printer, a copying machine, a facsimile, or the like using a laser. More specifically, the present invention relates to a belt traveling device that hangs a belt-like endless belt between a first roller and a second roller, rotates the rollers, and prevents the belt from shifting to run the belt.

2. Description of the Related Art In a belt traveling device of this type, for example, when a deviation occurs in the parallelism between rollers, the belt is biased to one side. Therefore, when this is used for a laser printer, a copying machine, or the like, there is a problem that an abnormal image such as image shift or fluctuation occurs.

Conventionally, in this type of belt traveling device, for example, as shown in FIG. 10, a second roller is operated by operating a solenoid 2 or a tension spring 3 by a signal of a belt sensor (not shown) provided near the side edge of the belt 1. 4, one end of the second roller 4 is rotated in the direction of the arrow P or Q to change the degree of parallelism with the first roller (not shown). In some cases, the belt 1 is moved in the direction of arrow C or D to adjust the deviation of the belt 1 (see JP-A-57-139775).

Problems to be Solved by the Invention However, the conventional belt traveling device shown in FIG. 12 requires a belt sensor, a solenoid 2, a tension spring 3 and the like in order to prevent the belt from being biased, so that the configuration becomes complicated and the cost increases. There were problems such as being noticeable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a belt traveling device that simplifies the configuration, reduces costs, and prevents belt deviation.

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 hangs a belt between a first roller and a second roller,
In a belt traveling device that travels a belt by rotation of those rollers, the belt is configured to be conveyed from a first roller to a second roller above the two rollers, and flange portions are provided at both ends of the second roller, The roller axis of the second roller is bent or bent symmetrically, and an intermediate portion of the roller axis of the second roller is substantially perpendicular to a plane including both ends of the roller axis and the roller axis of the first roller. And the second roller is provided so as to be movable in the axial direction of its roller shaft.

According to a second aspect of the present invention, there is provided a belt traveling device that hangs a belt between a first roller and a second roller, and runs the belt by rotation of the rollers. The first roller is configured to be conveyed from the second roller to the second roller. Flanges are provided at both ends of the second roller, and the roller axis of the second roller bends or bends symmetrically to the left and right. Is positioned downward in a plane substantially perpendicular to a plane including both ends of the roller shaft and the roller shaft of the first roller, and moves the second roller in the axial direction of the roller shaft. It is characterized by being provided freely.

Furthermore, the invention according to claim 3 is characterized in that the first roller and the second roller
In a belt traveling device that hangs a belt between rollers and runs the belt by rotation of the rollers, the belt is transported from a first roller to a second roller above the two rollers; Flanges are provided at both ends of the second roller, and both ends of the second roller are supported by separate roller shafts, respectively, and the leading ends of the roller shafts are connected to the base ends of the roller shafts and the roller shafts of the first roller. The second roller is disposed at a position facing upward in a plane substantially perpendicular to the plane including the second roller, and the second roller is provided movably in the axial direction of the roller shaft.

Still further, the invention according to claim 4 is a belt traveling device in which a belt is hung between a first roller and a second roller, and the belt runs by rotating the rollers. Is transported from the first roller to the second roller, flange portions are provided at both ends of the second roller, and both ends of the second roller are supported by separate roller shafts, respectively. The leading end is disposed at a position facing downward in a plane substantially perpendicular to a plane including the base end of the roller shaft and the roller shaft of the first roller, and the second roller is disposed in the axial direction of the roller shaft. Characterized in that it is provided so as to be movable.

According to a fifth aspect of the present invention, in the third or fourth aspect, the two roller shafts of the second roller are held by one holding member, and the holding member is biased by the urging member. Characterized by being urged in a direction in which tension is applied.

In the belt traveling device according to the present invention, when the traveling belt starts to shift to one side, the second roller moves to one end of the roller shaft following the deviation, and changes the inclination with the first roller. Then, the belt stops leaning to one side,
Then, the second roller starts to return to the other, and accordingly, the second roller also moves to the intermediate portion of the roller shaft and returns to the original position, thereby correcting the deviation of the belt.

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

FIG. 9 shows a laser printer provided with a belt traveling device according to the present invention, and shows an overall schematic configuration of an internal mechanism thereof. Reference numeral 10 in the figure denotes a printer main body. Printer body
Inside the photoreceptor belt 10, a photoreceptor belt traveling device 11 is provided at the center. Then, around the photoreceptor belt traveling device 11, in the rotation direction of the photoreceptor belt 11a (clockwise in the drawing),
Charging unit 12, optical unit 13, developing unit 14, transfer unit 15, static elimination unit 16, cleaning unit
Place 17 Further, on the right side of the printer body 10 in the figure, a paper feed tray 19 for storing paper 18 as a recording medium is removably loaded. The attachment portion of the paper feed tray 19 is provided with a paper feed unit 22 having a call roller 20, a paper feed roller 21, and the like. Further, on the side opposite to the paper supply unit 22 with the transfer unit 15 interposed therebetween, a transport unit 23 and a fixing unit 24 are arranged in order. Then, a paper receiving tray 26 on the printer main body 10 passes through the paper discharging unit 25 from the fixing unit 24.
Contact At the exit of the paper discharge unit 25, a pair of paper discharge rollers 27 is provided.

When printing is performed by the electrophotographic process using the laser printer, the paper 18 is sequentially sent out from the paper feed tray 19 by driving the calling roller 20. Then, the sheet is conveyed by the sheet feeding roller 21, and the leading end of the sheet 18 is detected by a registration sensor (not shown). Then, the sheet 18 is stopped so that the leading end of the sheet 18 abuts the registration roller pair 28.

On the other hand, the photoreceptor belt traveling device 11 includes a photoreceptor belt 11a.
While rotating clockwise in the figure, the surface of the photoreceptor belt 11a is sequentially and uniformly charged by the charging unit 12, and the next optical unit 13 irradiates a laser beam to electrostatic latent on the surface of the photoreceptor belt 11a. An image is formed, and when the image passes through the developing unit 14, the electrostatic latent image is sequentially visualized with toner, and a transfer image is formed on the surface of the photoreceptor belt 11a. Then, the transfer image is synchronized with the timing, and the registration roller pair described above is used.
The sheet 18 that has hit the sheet 28 is sent out toward the photoreceptor belt 11a. Then, the transfer image on the photoreceptor belt 11a is transferred to the sheet 18 in the transfer unit 15. After the transfer, the charge remaining on the photoreceptor belt 11a is removed by the charge removing unit 16, and the residual toner is cleaned by the cleaning unit 17.

On the other hand, the sheet 18 is sent to the fixing unit 24 by the transport unit 23, and the transferred image is thermally fixed by the fixing unit 24. After that, the paper is sent out to the paper discharge unit 25, discharged by the paper discharge roller pair 27 through the paper discharge unit 25, and the recorded paper 18 is sequentially stacked on the paper discharge receiver 26.

Incidentally, in the above-described laser printer, the photosensitive belt traveling device 11 includes a photosensitive belt 11a between a first roller (drive roller) 30 and a second roller (driven roller) 31, as shown in FIGS. Multiply by The first roller 30 has a roller shaft 33 rotatably attached to left and right side plates 32 and 32 fixed in the apparatus main body 10 via bearings 34, respectively. A drive gear 35 is provided at one end of the roller shaft 33.
For transmitting a driving force from a driving source via a gear train (not shown), for example. The second roller 31 has flange portions 31a at both ends, and a roller shaft 36 as shown in FIG.
Are provided rotatably and axially movable via a bearing 37. As shown in the figure, the roller shaft 36 has an intermediate portion which is curved symmetrically in the direction perpendicular to the plane including both ends of the roller shaft and the roller shaft 33 of the first roller 30. Both ends of the roller shaft 36 are inserted through the block members 38 so that they cannot rotate. As shown in FIG. 1, the block members 38, 38 are provided movably in the longitudinal direction of the elongated holes 39, 39 provided in the side plates 32, 32, and biasing members 40, 40 are respectively provided on one side.
Press one end of Then, as shown in FIG. 4, the photoreceptor belt is urged by urging the block members 38 in the direction of the arrow.
11a is tensioned.

Thus, the first roller 30 and the second roller 31
Drive the photoreceptor belt above both rollers
When the photoreceptor belt 11a starts to shift on the second roller 31 in, for example, the direction of arrow B when the photoreceptor belt 11a travels in the direction of arrow A shown in FIG. 5, the flange 31a is pushed. Therefore, the second roller 31 moves in the direction in which the photoreceptor belt 11a is biased, following the curvature of the roller shaft 36. And the first
As shown in FIG. 6, the second roller 31 is inclined by an angle θ between the roller 30 and the roller 30, and a parallelism shift occurs in a plane orthogonal to a plane including both the rollers 30 and 31. Then, as shown in the drawing, one point on the photosensitive belt 11a which enters at the point C on the second roller 31 returns from the point D, and the photosensitive belt
While 11a makes one rotation, it returns to the left by Δl in the figure. Therefore, the photoreceptor belt 11a starts to return and hits the flange 31a, and then the second roller 31 follows and returns to the intermediate portion of the roller shaft 36 to correct the deviation of the photoreceptor belt 11a.

Further, in all the embodiments described above, the second rollers 31 and 45 are used.
The middle part of the roller shafts 36 and 46 is curved symmetrically. However, in the belt traveling device according to the present invention,
As shown in FIG. 7 (a), the roller shaft 50 of the second roller is bent symmetrically at the middle bent portion 50a, or at the left and right bent portions 50b, 50b as shown in (b). It may be configured to be symmetrically bent.

Next, in the embodiment shown in FIG. 8, both ends of the second roller 53 are supported by separate roller shafts 54, 54, respectively. The roller shafts 54 are bent at a bent portion of a holding member 55 bent in a U-shape.
The base end portions are fixed to 55a and 55a, respectively, and the front end portions are provided to be inclined. The front end portions of the roller shafts 54 are connected to the base end portions of the roller shafts and the roller shaft of the first roller. It is arranged at right angles to the plane that contains it. One end of an urging member 56 is hung on the holding member 55. Then, the entire holding member 55 is pulled and urged to apply tension to the photoreceptor belt. As described above, separate roller shafts 54
Since it is configured to be supported by one holding member 55 and the whole is pulled by one spring 56, the number of parts can be reduced, the assembling work can be facilitated, and the cost can be reduced.

As described above, according to the belt traveling device of the present invention, when the belt is shifted, the second roller is moved according to the shift, and the inclination is changed between the first roller and the belt. Since the belt is offset and the offset is adjusted back, the configuration can be simplified by eliminating the conventional belt sensor, solenoid, spring, etc. to prevent the offset, reducing the number of parts and reducing costs. Can be planned.

[Brief description of the drawings]

FIG. 1 is a perspective view of a belt traveling apparatus according to an embodiment of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a longitudinal sectional view of a second roller portion, and FIG. FIG. 5 is an explanatory view for explaining that the photosensitive belt shifts to one side during traveling, and FIG. 6 is a diagram in which the second roller is tilted according to the shift of the photosensitive belt to correct the shift of the photosensitive belt. FIGS. 7 (a) and 7 (b) show another embodiment of the belt traveling device of the present invention. FIG. 7 (a) is a front view of a roller shaft of a second roller, and FIG. In another embodiment of the belt traveling device of the present invention, a perspective view of a part thereof,
FIG. 9 is a schematic configuration diagram of the entire internal mechanism in a laser printer including the belt traveling device of the present invention, and FIG. 10 is a perspective view of a part of the conventional belt traveling device. 11 photoreceptor belt traveling device, 11a photoreceptor belt, 30 first roller, 31, 45, 53 second roller, 36
· · · · · · · · · · · · · Roller shaft of the second roller 55 · · · · · · · · · · · · · urging member.

Claims (5)

(57) [Claims] 1. A belt traveling device which hangs a belt between a first roller and a second roller, and runs the belt by the rotation of the rollers, wherein the belt is moved from the first roller to the second roller above the two rollers. Flanges are provided at both ends of the second roller, and the roller shaft of the second roller is bent or bent symmetrically to the left and right, and the intermediate portion of the roller shaft of the second roller is connected to the roller. A belt disposed at a position facing upward in a plane substantially perpendicular to a plane including both ends of a shaft and a roller shaft of the first roller, and a second roller provided movably in an axial direction of the roller shaft; Traveling device. 2. A belt traveling device which hangs a belt between a first roller and a second roller, and runs the belt by the rotation of the rollers. The second roller is provided with flange portions at both ends thereof, and the roller axis of the second roller is bent or bent symmetrically left and right, and the intermediate portion of the roller axis of the second roller is moved to The second roller is disposed at a position facing downward in a plane substantially perpendicular to a plane including both ends of the roller shaft and the roller shaft of the first roller, and the second roller is provided movably in the axial direction of the roller shaft. Belt running device. 3. A belt traveling device which hangs a belt between a first roller and a second roller and runs the belt by the rotation of the rollers, wherein the belt is moved from the first roller to the second roller above the two rollers. And a flange portion is provided at both ends of the second roller, and both ends of the second roller are supported by separate roller shafts, respectively.
The tip of each of the roller shafts is positioned upward in a plane substantially perpendicular to the plane containing the base ends of the roller shafts and the roller shaft of the first roller, and the second roller The belt traveling device is provided so as to be movable in the axial direction of the roller shaft. 4. A belt traveling device which hangs a belt between a first roller and a second roller, and runs the belt by the rotation of the rollers. The second roller is provided with flange portions at both ends thereof, and both ends of the second roller are supported by separate roller shafts, respectively.
The distal end of each of the roller shafts is positioned downward in a plane substantially perpendicular to the plane containing the base end of the roller shafts and the roller shaft of the first roller, and the second roller , Which are provided so as to be movable in the axial direction of the roller shafts. 5. The apparatus according to claim 3, wherein two roller shafts of said second roller are held by one holding member, and said holding member is urged by an urging member in a direction of applying tension to said belt. 5. The belt traveling device according to 4.