JPH0451279A - belt running device - Google Patents

Abstract

PURPOSE:To prevent the generation of the winding set of rollers on the belt of the belt traveling device by operating a driving motor to regulate or release the turning of a tension lever. CONSTITUTION:Recording on paper by a laser printer equipped with the belt traveling device is executed by first operating the driving motor 35 to release the turning restriction of the tension lever 39 by an eccentric cam 37 and turning the tension lever 39 clockwise by a tension spring 40. A driven roller 13a is then moved by this lever 39 in the tensing direction of the photosensitive belt 14 against the moving habit of the driven roller and the belt is extended. The motor 35 is operated, upon ending of the recording, to regulate the clockwise turning of the lever 38. The roller 13a is then moved in the loosening direction of the belt 14 in accordance with the moving habit thereof and the belt 14 is loosened. The generation of the winding set of the roller on the belt is prevented in this way and the degradation in the image quality is prevented.

Description

[Detailed description of the invention] 11th direct sacrificial anus! The present invention can be applied to, for example, a photoreceptor belt running device that uses a laser and is included in printer/ladder copying machines, facsimile machines, and the like. Specifically, the present invention relates to a belt running device that stretches a wide endless belt between a plurality of rollers and runs the belt as the rollers rotate.

14 This type of belt running device has a photoreceptor belt stretched between a drive roller and two driven rollers, rotates the drive roller by transmitting rotation from the drive device, and rotates the drive roller together with the drive roller. The photoreceptor belt is configured to run. Laser printers and the like that incorporate this belt running device create an image on the surface of the photoreceptor belt using an image forming device such as a laser writing device or a developing device, and record the image by transferring it to paper. . Therefore, in this laser printer, etc., a certain tension is applied to the photoreceptor belt, and the belt is stretched between the rollers.

However, in this conventional belt running device, the photoreceptor belt is always stretched between the rollers regardless of whether it is being driven or not, so it is difficult to solve the problem for a long time. If the photoreceptor belt is not used for a long time, the rollers will curl around the photoreceptor belt, resulting in uneven development on the surface of the photoreceptor belt.
There have been problems such as deterioration of the quality of images formed on paper. Therefore, the purpose of the present invention is to prevent the belt from curling around the rollers in the above-mentioned belt running device. be.

Therefore, the belt running device 11 of the present invention according to claim 1 is similar to, for example, FIGS. 1 and 2.

As in the example shown in Fig. 6 Wi and Fig. 7.

A drive motor 35, a tension lever 39 that regulates or releases the rotation by the operation of the drive motor 35, a tension spring 40 that biases the tension lever 39 in one rotation direction, and the tension spring 40. The driven roller 1 moves against the movement habit by the tension lever 39, which is biased in the direction of one rotation.
3a and.

A belt such as the photoreceptor belt 14, which is stretched around the driven roller 13a, is stretched when it moves against the movement habit, and is loosened when it moves based on the movement habit, and the belt is rotated. It is characterized by comprising a drive roller 12 for driving the drive roller.

Further, a belt running device 45 of the present invention according to claim 2
For example, FIGS. 3 to 5 and FIGS. 6 and 7
As shown in the embodiment shown in the figure, there is a sun gear 5o that rotates due to the operation of a drive device, a planetary gear 49 that meshes with the sun gear 50 and revolves around it, and a drive that is coaxial with the planetary gear 49 and rotates integrally with it. roller 12;
A shaft that connects a belt such as the photoreceptor belt 14, which is stretched between the driving roller 12 and the driven rollers 18a and 13b and is driven by the rotation of the driving roller 12, and the shafts of the sun gear 50 and the planetary gear 49. A support bracket 53, a biasing means such as a return spring 54 that biases the pivot bracket 53 in one rotation direction, and the pivot bracket 5
3 and the roller shaft 46 of the drive roller 12, and a friction member such as a friction brake 55 that applies a constant load to the rotation of the planetary gear 49.

In the belt running device of the present invention as set forth in claim 1, for example, when recording, the drive motor 35 is activated to release the rotation restriction of the tension lever 39, and the tension lever 39 is moved. It rotates with a tension spring 40. Then, the tension lever 39 moves the driven roller 13a.
The belt is moved against the movement habit to stretch the belt, and the drive roller 12 is rotated to drive the belt. After recording is completed, the drive motor 35 is activated to restrict rotation of the tension lever 39, and the driven roller 13a is moved based on its movement behavior to loosen the belt.

Further, the belt traveling device 14 of the present invention according to claim 2
5, when the drive device is activated when recording, for example, the sun gear 50 rotates, revolves around the planetary gear 49, rotates the pivot bracket 53 against the biasing means, and stretches the belt. Then, when the rotational load on the planetary gear 49 becomes smaller than the rotational load on the shaft support bracket 35, the rotation of the shaft support bracket 53 is stopped, the planetary gear 49 rotates, and the belt is driven. After the recording is completed, the operation of the drive device is stopped, and the sun gear 50 stops rotating. Then, the pivot bracket 53 rotates based on the urging means, revolves around the planetary gear, and loosens the belt.

Loss-1-5 The present invention will be described in detail below with reference to one drawing.

FIG. 4 shows an overall schematic configuration of the internal mechanism of a laser printer to which the present invention is applied, and FIG. 5 shows a schematic configuration of main parts of the internal mechanism. It is the main body. The printer main body 10 has a
Belt traveling device according to this invention! 11 or 45. The belt traveling device 11 or 45 includes a drive roller 12
A wide and endless photoreceptor belt 14 is stretched between two driven rollers 13a and 13b. Although not shown, the rotation from the drive device is transmitted to rotate the drive roller 12, and along with the rotation of the drive roller 12, the photoreceptor belt 14 is rotationally driven in the direction of the arrow in the figure. Then, the surface of the photoreceptor belt 14 is uniformly charged with a charger 15, an electrostatic latent image is formed on the surface by writing with a laser writer 16, and the latent image is developed with a developer 17. Visualize.

On the other hand, a paper feed cassette 18 is detachably attached to the right side of the printer main body 10 in the figure. And paper cassette 1
Automatic paper feed bag for paper 19 stored in 8! 20 to feed out the sheets one by one, and the tip is placed between a pair of registration rollers 21 and 21.
Stop it by hitting it in between.

Then, the registration rollers 21 and 21 are rotated in synchronization with the visible image on the photoreceptor belt 14, and the paper 19 is guided between the photoreceptor belt 14 and the transfer device 22. A device 22 transfers the visible image on the photoreceptor belt 14 onto the upper surface of the paper 19, and sends it to a fixing device 23, where the transferred image is fixed. After that, paper 1 after fixing
9 is discharged to the paper discharge section 24 on the printer main body 10.

On the other hand, the surface of the photoreceptor belt 14 after the transfer is cleaned by a cleaning device 25, and is uniformly charged again by a charger 15.

By the way, the belt running device 11 of the present invention according to claim 1 applied to the illustrated laser printer described above is provided removably from the device main body 10, and has a configuration as shown in FIG. 1 in detail. Reference numeral 30 is a drive gear to which rotation from the drive device is transmitted. The driving gear 30 is a driven gear 31 provided coaxially with the driving roller 12.
On the other hand, of the two driven rollers, the lower driven roller 13a in the figure has its roller shaft 32 connected to a guide elongated hole 33 provided in a side plate (not shown) via a bearing (not shown).
penetrate. Then, it is supported by a side plate so as to be rotatable about the roller shaft 32 and movable along the guide elongated hole 33. Additionally, the other end of a loosening spring 34, which has one end hooked to the side plate, is hooked to the roller shaft 32. and,
The loosening spring 34 always urges the driven roller 13a in the direction of loosening the photoreceptor belt 14 (in the diagonally upper right direction in the figure) to give it a moving habit. Further, this belt traveling bag w11 has a drive motor 35 attached to the side plate. The drive motor 35 is provided with an eccentric cam 37 on its motor shaft 36 that is eccentric by a certain amount with respect to the motor shaft 36. On the lower side of the eccentric cam 37.

A tension lever 39 is provided which is rotatably attached to the side plate about a support shaft 38. One end 39a of the tension lever 39 is hooked to the other end of a tension spring 40, which is hooked at one end to the side plate. The tension spring 40 constantly pulls the tension lever 39 in a direction that tensions the photoreceptor belt 14 (diagonally downward to the left in the figure) and urges it clockwise. As shown in FIG. 2, when the drive motor 35 is operated and the center of the eccentric cam 37 is located below the motor shaft 36, the eccentric cam 3
7, push down the other end 39b of the tension lever 39 against the tension spring 40.

Clockwise rotation of the tension lever 39 is restricted.

Then, the driven roller 13a is pulled by the loosening spring 34 and moved in the direction in which the photoreceptor belt 14 is loosened. On the other hand, as shown in FIG. 1, when the drive motor 35 is operated and the center of the eccentric cam 37 is located above the motor shaft 36, the other end 39b of the tension lever 39 separates from the eccentric cam 37 and the tension lever 39 into a free state, and its rotation restriction is released. Then, the tension lever 39 is pulled clockwise by the tension spring 40 against the loosening spring 34, and one end 39a of the tension lever 39 is pressed against the roller shaft 32 of the driven roller 13a, and the driven roller 13a is exposed to light. It is configured to move in the tensioning direction of the body belt 14.

Now, the belt running device 1 according to claim 1 described above.
When recording on paper 19 with a laser printer equipped with 11, as shown in FIG. is rotated clockwise by the tension spring 40. Then, the tension lever 39 moves the driven roller 13a in the tensioning direction of the photoreceptor belt 14 against its movement habit to stretch the photoreceptor belt 14. Thereafter, the drive roller 12 is rotated to tighten the photoreceptor belt 14. 14, an image is formed on the surface of the photoreceptor belt 14, and the image is transferred onto the paper 19 for recording. After this recording is completed, the drive motor 35 is activated as shown in FIG. Then, the eccentric cam 37 restricts the clockwise rotation of the tension lever 39. Then, the driven roller 13a moves in the direction of loosening the photoreceptor belt 14 based on its movement behavior, thereby loosening the photoreceptor belt 14. Therefore, even when storing the belt traveling device 11, it is only necessary to remove it from the device main body 10, and there is no need to loosen the photoreceptor belt 14 by a separate appropriate means.

Further, a belt running device 45 of the present invention according to claim 2, which is also applied to the illustrated laser printer, has a structure as shown in FIGS. 3 to 5.

That is, in this belt traveling device 1145, the drive roller 12 passes its roller shaft 46 through a guide elongated hole 48 provided in a side plate 47, and is rotatable about the roller shaft 46 and movable along the guide elongated hole 48. I support it at 47. Also, a planetary gear 49 is mounted on the same roller shaft 46.
is provided so as to be rotatable integrally with the drive roller 12. The planetary gear 49 meshes with a sun gear 50, and the sun gear 5o meshes with a drive gear 51 that rotates due to the operation of the device. They are connected using a bracket 53. The pivot bracket 53 is attached to the support shaft 52 so as to be rotatable about it. A return spring (biasing means) 54 that hooks one end of the pivot bracket 53 to the side plate 47
The other end is latched, and the pivot bracket 53 is constantly urged in the clockwise direction in FIG. 3, where the photoreceptor belt 14 is loosened. moreover.

A friction brake (friction member) 55 is provided between the shaft support bracket 53 and the roller shaft 46 to restrict rotation of the roller shaft 46 by friction. Then, the friction brake 55 applies a constant load to the rotation of the planetary gear 49. Therefore, when the sun gear 50 is rotated in the direction of the arrow in FIG.
Due to the rotational load 9, the planetary gear 49 revolves, and the pivot bracket 53 is rotated counterclockwise about the support shaft 52 against the return spring 54. The drive roller 12 is moved integrally with the shaft support bracket 53, and is configured to move in the tensioning direction of the photoreceptor belt 14 (to the right in the figure) along the guide elongated hole 48 and via the roller shaft 46. .

Now, the belt running device w4 according to claim 2 mentioned above.
When recording with the illustrated laser printer equipped with 5, as shown in FIG.
Rotate 0. Then, the planetary gear 49 with one rotation load
The shaft support bracket 53 is rotated counterclockwise in the figure to stretch the photoreceptor belt 14, and when the tension of the photoreceptor belt 14 exceeds a certain level, the shaft support bracket 5
When the rotational load on the planetary gear 49 becomes smaller than the rotational load applied to the drive roller 12, the pivoting bracket 53 stops rotating, the planetary gear 49 rotates, and the photoreceptor belt 14 is driven together with the drive roller 12. However, the photoreceptor belt 14
After recording is completed, the sun gear 50 stops rotating when the driving device stops operating. Then, the pivot bracket 53 rotates clockwise in FIG. 3 based on the return spring 54, the roller shaft 46 moves along the guide elongated hole 48, and the drive roller 12 is moved leftward in the diagram to remove the photoreceptor. Loosen the belt 14.

Therefore, according to the present invention, since the belt is loosened when the belt is not driven, it is possible to prevent the belt from curling around the rollers. It is possible to prevent the image quality from deteriorating when recording an image on paper using the above-mentioned method.

Furthermore, in the present invention as set forth in claim 2, the belt is stretched by applying tension to the belt when it is driven by the belt driving device without using a separate driving device, so in addition to the above-mentioned effects, space can be saved. .

This has the effect of keeping costs low.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the operating state of the belt running device in which the photoreceptor belt is stretched in one embodiment of the present invention as set forth in claim 1, and FIG. It is an explanatory view of an operating state. FIG. 3 is an explanatory diagram of the operating state of a belt running device in which a photoreceptor belt is stretched in one embodiment of the present invention as set forth in claim 2, FIG. 4 is a partially enlarged sectional view of the belt running device, and FIG. The figure is a schematic configuration diagram showing a configuration in which a friction brake is provided between the shaft support bracket and the roller shaft of the drive roller. FIG. 6 is an overall schematic diagram showing the internal mechanism of a laser printer equipped with the belt running device of the present invention, and FIG. 7 is an enlarged diagram of the main part of the internal mechanism. 11.45...Belt running device, 12.
...... Drive roller, 13a, 13b...
...Followed roller, 14...Photoreceptor belt (belt), 35...Driving motor, 39...Tension lever , 40...
・・・・・・Tension spring, 49・・・・・・
...Planetary gear, 50...Sun gear,
53...... Pivot bracket, 55...
...Friction brake (friction member). Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A drive motor, a tension lever that regulates or releases the rotation by the operation of the drive motor, a tension spring that biases the tension lever in the direction of one rotation; a driven roller that moves against the movement habit by the tension lever biased in one rotation direction by a tension spring; A belt running device comprising: a belt that is loosened when moving based on movement habits; and a drive roller that spans the belt and drives it by rotation. 2. A sun gear that rotates due to the operation of the drive device, a planet gear that meshes with the sun gear and revolves around it, a drive roller that is coaxial with the planet gear and rotates integrally with it, and a space between the drive roller and the driven roller. a belt that spans and is driven by the rotation of the drive roller; a pivot bracket that connects the shafts of the sun gear and the planetary gear; and urging means that urges the pivot bracket in the direction of one rotation; A belt running device, comprising: a friction member that is provided between the shaft support bracket and the roller shaft of the drive roller and applies a constant load to the rotation of the planetary gear.