JPH03261981A - Belt driving device and electrophotographic device using the same - Google Patents

Abstract

PURPOSE:To use a belt for a long period without the replacement of the belt by moving the exposed part of the belt along a specific track at both a belt take-up part and a drawing part. CONSTITUTION:A belt updation feeding device 10 moves a moving base 10a backward normally to allow the rotation of a conveyor belt to be free, but when a transfer belt is updated, the moving base 10a is moved forward at the position where both shafts face each other to couple both the shafts with each other, which are rotated by a updating motor 10b to feed one end part of the transfer belt 9 and wind the other end part simultaneously, thereby performing update operation for updating the exposed part. Consequently, when the exposed part of the belt 9 is deteriorated, the deteriorating exposed part is taken-up in the take-up part 7 to expose the unused belt part stored in the belt drawing part 8 between the belt drawing part 8 and belt take-up part 7. Consequently, the belt can be used for a long time without being replaced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a belt drive device and an electrophotographic apparatus using the belt drive device, and particularly relates to the renewal of a deteriorated belt.

[Conventional technology]

Basically, an electrophotographic apparatus first uniformly charges the surface of a photoconductor, and then exposes the surface of the photoconductor to light corresponding to the image to be recorded to form an electrostatic latent image. Next, the electrostatic latent image is developed to form a toner image, and the toner image is first transferred to recording paper and fixed.

A transfer device that transfers a toner image on the surface of a photoconductor onto recording paper applies a charge for transfer to the back side of the recording paper using a corona charger while the recording paper is in close contact with the surface of the photoconductor. It is moved toward the recording paper side by electrostatic force generated by transfer charges. This type of transfer device is based on the assumption that the recording paper is in close contact with the photoconductor surface, and if it is not in close contact, the toner image will have to travel (transfer) over a long distance, causing the toner particles to spread. This has the disadvantage that a clear transferred image (toner image transferred to recording paper) cannot be obtained.

An example of a transfer device that allows the recording paper to come into close contact with the surface of the photoconductor is a belt transfer device as described in Japanese Patent Laid-Open No. 59-184377. This transfer device is equipped with an endless transfer belt that revolves so that a part of the belt contacts the surface of the photoconductor, and the surface of this transfer belt is charged in advance, and the recording paper is electrostatically attracted to the surface of the transfer belt. Then, the recording paper is pressed (closely attached) to the surface of the photoconductor to transfer the toner image.

[Problem to be solved by the invention]

However, this belt transfer device has the problem that the transfer belt wears out due to contact with the recording paper or the photoconductor, and the electrical characteristics deteriorate due to ozone generated from the charger, so that the belt must be replaced in a short period of time.

The object of the present invention is to enable this type of belt to be used for a long period of time without being replaced.

[Means to solve the problem]

The first invention is characterized in that the exposed part of the belt stretched between the belt winding part and the belt feeding part is moved along a specific trajectory together with the belt winding part and the belt feeding part, A second invention provides a belt drive device configured to move an exposed portion of a belt stretched between a belt winding part and a belt feeding part along a specific trajectory together with the belt winding part and the belt feeding part; an electrophotographic photoconductor disposed so as to be in contact with the moving trajectory of the surface of the exposed portion of the belt; means for forming a toner image on the surface of the photoconductor; and means for electrostatically attracting recording paper to the surface of the belt. A third invention is characterized in that the recording paper adsorbed on the surface of the e-belt is brought into contact with the electrophotographic photoconductor to transfer the toner image on the surface of the electrophotographic photoconductor to the recording paper. a belt drive device configured to move an exposed portion of a photoconductive belt stretched between a belt winding section and a belt feeding section along a specific trajectory together with the belt winding section and the belt feeding section; A means for forming a toner image on the surface of an exposed portion of the conductive belt, and a means for bringing a recording paper into contact with the surface of the photoconductive belt, the toner image on the photoconductive surface being transferred to the recording paper. It is characterized by

[Effect]

When the exposed part of the belt stretched between the belt feeding part and the belt winding part deteriorates, the unused belt part stored in the belt feeding part can be reused by winding up the deteriorated exposed part in the winding part. It can be exposed between the belt feeding part and the belt winding part, and the part where the belt is used (
The exposed part) can be updated in the same way as replaced.

〔Example〕 Embodiments of the present invention will be described below with reference to the drawings.

Example 1 FIG. 1 is a side view of an electrophotographic apparatus embodying the present invention. A toner image 2 is formed on the outer peripheral surface of the photoreceptor drum 1 by charging, exposure, and development. a transfer device 4 that transfers the toner image 2 on the outer circumferential surface of the photosensitive drum 1 to a recording paper 3;
is the drive pulley 5a.

5b, an endless conveyor belt 6, a belt winding section 7 and a belt unwinding section 8 attached to the conveyor belt 6 at a predetermined interval, and one end of which is attached to the belt unwinding section 8.
A transfer belt 9 is housed in the transfer belt 9 , the other end is wound up in the winding section 7 , and the exposed part of the belt is stretched between the belt feeding section 8 and the belt winding section 7 . a belt renewal feeding device 10 that renews the exposed portion of the transfer belt that is driven to rotate; a belt cleaning device f, 11 that cleans the exposed portion of the transfer belt; and a charging device 12 that charges the exposed portion of the rotation belt; A recording paper supply device 13 and the like is provided that supplies the recording paper 3 to the exposed portion of the charged transfer belt and causes it to be electrostatically attracted.

The drive pulley 5a is driven in the direction of the arrow by the drive motor 14, and thereby rotates around the conveyor belt 6 in the direction of the arrow. The belt feeding section 8 has a feeding shaft 8b disposed at the center of a storage tube 8a having a feeding slit, and stores the transfer belt 9 wound around the shaft 8b. The belt winding section 7 has a shaft 7b arranged at the center of a storage cylinder 7a in which a winding slit is formed.

The transfer belt 9 is wound around the shaft 7b.

The transfer belt 9 is made of an insulating material in the form of a sheet, and one end thereof is wound around the shaft 8b of the belt feeding section 8 and stored in the storage tube 8a, and the other end is wound around the shaft 8b of the belt winding section 7. 7b and stored in the storage cylinder 7a, and the part between them is exposed between the winding part 7 and the feeding part 8, and serves as an exposed part where the recording paper 3 is electrostatically sucked up and conveyed.

Belt update sending equipment! 1.0, as shown in FIG.
The movable base 10a is normally moved backward to allow the conveyor belt 6 to circulate freely, and when the transfer belt is updated, the movable base 10a is placed opposite the shaft 8b of the belt feeding section 8. The transfer belt 9 is moved forward to connect both shafts, and the update motor 10b rotates both shafts to perform an update operation in which one end of the transfer belt 9 is let out and the other end is wound up to update the exposed portion.

The transfer belt update timing is determined by referring to the number of revolutions of the conveyor belt 6, and the drive motor 14 that drives the conveyor belt 6 is configured to perform the above-described updating operation when a predetermined number of revolutions is reached. Signals are supplied to each of the update motor 10b that updates and drives the transfer belt 9 and the power device that moves the moving base 10a.

This update timing may be determined based on a resistance measurement result by a resistance measurement device provided in the orbit for measuring the surface resistance or volume resistance of the transfer belt 9.

FIG. 3 shows the relationship between the exposed belt portion of the transfer belt 9 that rotates as the conveyor belt 6 rotates, the outer peripheral surface of the photosensitive drum 1, the belt cleaning device 11, and the charging device 12.

When the exposed portion of the transfer belt 9 passes through a position facing the photosensitive drum 1, the cleaning device fill, and the charging device 12, the relative distance between each position of the exposed portion of the transfer belt 9 and these must be constant. . For example, in Figure 3 (A
), when the belt feeding portion 8 is located below the uppermost position on the outer circumference of the drive pulley 5b, the belt winding portion 7
When the transfer belt advances beyond the position of the photosensitive drum 1, the exposed portion of the transfer belt cannot come into contact with the surface of the photosensitive drum, and in such a state, normal toner image transfer cannot be performed. Therefore, when the exposed portion of the transfer belt 9 reaches a position facing the photosensitive drum 1, the drive pulley is moved so that the transfer belt 9 is parallel to the conveyor belt 6, as shown in FIG. 3(B). 5b position must be set. Such considerations are also necessary to maintain the relative relationships between the cleaning device 11, the charging device 12, and the transfer belt 9. That is, when the conveyor belt 6 is stretched horizontally, the horizontal distance from the center position of the photosensitive drum 1 to the center position of the drive pulley 5b needs to be equal to or longer than the length of the exposed portion of the transfer belt 9. The horizontal distance from the center position of the cleaning device 11 to the center position of the drive pulley 5a needs to be equal to or longer than the length of the exposed portion of the transfer belt 9.
The distance in the horizontal direction from the end position of the drive pulley 5b to the center position of the drive pulley 5b needs to be equal to or longer than the length of the exposed portion of the transfer belt 9.

Embodiment 2 FIGS. 4A to 4D show a second embodiment that is a modification of the first embodiment described above. In this embodiment, a follow-up type correction roll 16 is provided between the belt winding section 7 and the belt feeding section 8, which is not fixed to the conveyor belt 6 and the transfer belt 9 and rotates along a separate track rail. It is something that The straightening roll 16 moves the photosensitive drum 1 to the drive pulley 5b.
In a device that aims to downsize by shortening the horizontal portion of the conveyor belt 6 by arranging it near the conveyor belt 6, the exposed portion of the transfer belt 9 is The photosensitive tram 1 is stopped as shown in FIG. 4(A) in order to press against the outer circumferential surface of the photosensitive tram 1, and when the belt winding section 7 and the belt feeding section 8 revolve around the horizontal portion of the conveyor belt 6, as shown in FIG. 4(B). transfer belt 9
The belt feeding section 8 rotates around the drive pulley 5a.
While rotating around the outer circumference of the drive pulley 5b, the transfer belt 9 stops as shown in FIG. During this period, the exposed portion of the transfer belt 9 is stopped as shown in FIG. 4(D) in order to face the charging device 12 at a predetermined distance. In order to rotate the correction roll 16 in this way, the conveyor belt 6
A separate drive system is prepared.

FIG. 5 shows a drive system for rotating the correction roll 16 in this manner.

The track rail 17 is arranged along the conveyor belt 6 in a state independent from the conveyor belt 6, and the track rail 17
7 between the power system 18 and the straightening roll 16, and the power system 1
8 is a sliding power supply rail 1 formed as a part of the track rail 17
The straightening roll 1 is rotated by receiving a control signal from 7a.
6 is moved as described above.

In this embodiment, since the straightening roll 16 can move along the conveyor belt 6, the trajectory shape of the conveyor belt 6 can be freely set.

Embodiment 3 This embodiment is an example in which a straightening roll that plays the role of the straightening roll 16 of the second embodiment described with reference to FIG. 4 is provided at a fixed position in correspondence with the drive pulleys 5a and 5b. . The straightening rolls are indicated by reference numerals 16a and 16b in FIG. 6(A).
, 16c, 16d, the driving pulleys 5a, 5
They are provided corresponding to the upper and lower positions of b. As shown in FIG. 6(B), each straightening roll is provided with rotors 20a and 20b on a horizontally rotatable base 19, and is positioned at a position corresponding to the widthwise end of the conveyor belt 6. The belt winding part 7 and the belt feeding part 8 are rotated so as to be parallel to the edge of the conveyor belt (indicated by a broken line) when the belt winding part 7 and the belt feeding part 8 pass. It was designed so as not to interfere with the

Embodiment 4 In each of the embodiments described above, one transfer belt 9 is rotated, but when it is desired to shorten the conveyance interval of recording paper during high-speed recording, a plurality of transfer belts may be arranged around the conveyance belt 6. It's good to do that.

In this embodiment, as shown in FIG. 7, five sets of transfer belts 9 and correction rolls 16 are arranged around the conveyor belt 6.

Embodiment 5 In this embodiment, as shown in FIG. 8, the exposed portion of one transfer belt 9 is lengthened and arranged to cover almost the entire circumference of the conveyor belt 6, and a plurality of correction rolls 16e, 16f,
16g, 16h, 16i.

16j, the circumferential shape was corrected.

Embodiment 6 In each of the embodiments described above, the conveyor belt 6 is rotated and the transfer belt 9 is moved together with the belt winding section 7 and the belt feeding section 8.
However, it is also possible to apply rotational force to the transfer belt 9 itself. This example is based on the ninth
As shown in Figure (A), three drive pulleys 21 that apply rotational force to the transfer belt 9 are arranged around which the exposed portion of the transfer belt 9 is wound. The orbits of the shafts 7 b and 8 b of the belt feeding section 7 and the belt feeding section 8 are regulated by guide rails 22 .

As shown in FIG. 9(B), each drive pulley 21 has a large number of small parts rotatably arranged on the periphery of the holding disc 21a, except for the area that accommodates the belt winding part 7 and the belt feeding part 8. A pulley 21b, a first drive motor 21c for rotating or stationary the holding disk 21a, and a rotating disk 2
A second drive motor 21e is provided for rotating the small pulley 21b via the motor 1d.

The transfer belt 9 is rotated so as to come into contact with the outer periphery of the small boob U 2 l b, and rotational force is applied by rotating each of the small pulleys 21b by the second drive motor 21e. When the belt winding section 7 and the belt feeding section 8 pass the position of the drive pulley 21, the first drive motor 21c drives the holding disc 21a.
The belt winding section 7 and the belt feeding section 8 are accommodated in the area where the small pulley 21b is omitted, and the belt winding section 7 and the belt feeding section 8 are passed therethrough.After that, the transfer belt 9 is rotated again by rotating the small pulley 21b. go around.

Embodiment 7 Each of the embodiments described above is directed to the transfer belt 9, but such a circulating belt means is applied to a means for circulating a photosensitive belt for forming an electrostatic latent image in an electrophotographic process. be able to. In this case, instead of the transfer belt 9, a belt made of a photoconductive material or a belt made of a conductive material whose surface is coated with a photoconductive material may be used. If this belt is used in the same manner as the photosensitive drum 1 described above, an electrophotographic apparatus that can be used while easily updating the photosensitive surface can be obtained.

〔Effect of the invention〕

As described above, in the present invention, the exposed portion of the belt stretched between the belt winding section and the belt feeding section is moved along a specific trajectory together with the belt winding section and the belt feeding section. When the exposed portion of the belt stretched between the belt feeding section and the belt winding section deteriorates, the unused belt section stored in the belt feeding section can be reused by winding up the deteriorated exposed portion into the winding section. It can be exposed between the feeding section and the belt winding section.

The belt can be renewed in the same way as replacing the used part (exposed part), and the belt can be used for a long period of time without having to be replaced.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is a side view of an electrophotographic apparatus embodying the present invention, FIG. 2 is a perspective view of a belt renewal feeding device, and FIG. 3 (A). (B) is a side view showing the correspondence relationship between the exposed belt portion of the transfer belt rotating as the conveyor belt rotates, the outer peripheral surface of the photosensitive drum, the belt cleaning device, and the charging device, and FIGS. 4(A) to 4(B). (D) is a side view showing the second embodiment of the transfer belt drive device, FIG. 5 is a perspective view showing the drive system for rotating the correction roll, and FIGS. 6(A) and (B) are Side view and perspective view showing modified examples of the straightening roll, FIGS. 7 and 8
The figure is a side view showing a modification of the transfer belt, FIG. 9(A). (B) is a side view and a perspective view showing a modification of the transfer belt and drive pulley. 1... Photosensitive drum, 4... Transfer device [,
5a. 5b...Drive pulley, 6...Transport belt, 7...Belt winding section, 8...Belt feeding section, 9...Transfer belt, 10... ...Belt renewal feed device. 1 Figure I'4 Laofu 1 drum 2, toner n1 4: transfer table 6.1 and d (to 7゛ to 8) hef L to 1t to 9: to transfer 'Rot 112I!! 5th stage (A) Figure 6 (8) Figure 17 Figure 8 Figure 13 (A) (8) (A) Figure 4 (B) (C) (D) Figure 9 (B )

Claims (1)

[Claims] 1. The exposed part of the belt stretched between the belt winding part and the belt feeding part is moved along a specific trajectory together with the belt winding part and the belt feeding part. belt drive device. 2. The belt drive device according to claim 1, wherein the orbit is a circular orbit. 3. A belt drive device according to claim 1 or 2, characterized in that the belt is composed of a single sheet or a composite sheet of a conductor or an insulator. 4. A belt drive device according to any one of claims 1 to 3, characterized in that the belt surface is photoconductive. 5. A belt driving device according to any one of claims 1 to 3, wherein the belt is photoconductive. 6. A belt drive device configured to move an exposed portion of a belt stretched between a belt winding section and a belt feeding section along a specific trajectory together with the belt winding section and the belt feeding section, and an exposed portion of the belt. An electrophotographic photoconductor disposed so as to be in contact with the movement trajectory of the partial surface, means for forming a toner image on the surface of the electrophotographic photoconductor, and means for electrostatically attracting recording paper to the belt surface. An electrophotographic apparatus, characterized in that a recording paper adsorbed on the surface of the belt is brought into contact with the electrophotographic photoconductor to transfer a toner image on the surface of the electrophotographic photoconductor to the recording paper. 7. A belt drive device configured to move an exposed portion of a photoconductive belt stretched between a belt winding section and a belt feeding section along a specific trajectory together with the belt winding section and the belt feeding section; means for forming a toner image on the surface of an exposed portion of the photoconductive belt; and means for bringing a recording paper into contact with the surface of the photoconductive belt on which the toner image is formed;
An electrophotographic apparatus characterized in that a toner image on a photoconductive surface is transferred to recording paper.