JP2001331048A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device by which safety in terms of a quality is secured when an operator performs exchange due to the end of the life of a transfer roller or the like by preventing the transfer roller of a transfer roller unit from falling down in a direction in which it is grounded on a desk upper surface or the like without making a device large-sized. SOLUTION: A holder incorporating a handle B-6 which the operator holds at the time of attaching/detaching the transfer roller unit is provided so as to be freely rotatable with the transfer roller 12 in the transfer roller unit. In the case that the operator holds the handle B-6 by a hand C, the line of action L of gravity actuated to the transfer roller unit passes nearly the center position of the transfer roller 12. When the transfer unit is put on a desk D, the transfer roller unit falls in an (a) direction because it has a projected part B-3 on a transfer position side lower part than the line of action L of the center of gravity, so that it does not fall in a (b) direction in which it comes into contact with the upper surface of the desk D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on paper, such as an electrophotographic printer or copier.

[0002]

2. Description of the Related Art FIG. 6 is a view showing the handling state of a conventional transfer roller unit, and FIG. 7 is a view showing the state when the conventional transfer roller unit is collapsed. FIG. 6 shows a handle B of the transfer roller unit B ′.
This shows a state in which the operator holds and holds -6 with the hand C. When the operator holds the handle B-6 with the hand C, the line of action L of gravity acting on the transfer roller unit B '
Substantially passes through the center position of the transfer roller 12. When the transfer roller unit B ′ is to be placed on the desk D as shown in FIG.
Since the support member B-2 that supports both ends of the transfer roller 12 has a substantially circular shape, the transfer roller unit B ′ falls down in either the a or b direction.

[0003] As shown in FIG. 7, if it falls down in the direction b, a concave portion B- 4 configured so as not to contact the intermediate transfer belt is located on the desk top surface D side, and the surface of the transfer roller 12 is in contact with the desk top surface D. Contact. The transfer roller 12 generally has low mechanical strength, and if the surface is scratched, it affects the transfer performance and causes deterioration in image quality. In addition, if dust adheres, the quality of the image deteriorates as well as the scratches, and there is a risk that the transfer roller 12 or peripheral components may be damaged.

[0004]

As a means for solving the above-mentioned conventional problems, it is conceivable to prevent the transfer roller unit B 'from falling down. 2 needs to be increased, and there is a problem that the apparatus becomes large.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and prevents a transfer roller of a transfer roller unit from falling down in a direction in which the transfer roller contacts a desk surface or the like without increasing the size of the apparatus.
It is an object of the present invention to provide an image forming apparatus capable of ensuring quality and safety when an operator replaces a transfer roller due to a service life of the transfer roller.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an image forming apparatus for forming an image on a sheet by an electrophotographic method, comprising a transfer roller for transferring a toner image formed in an image forming process section onto the sheet. A support portion for supporting both ends is formed integrally with a handle member that is held when the transfer roller is attached and detached, and a transfer position is defined by an action line passing through the center of gravity of the transfer roller when the handle member is supported by hand. A convex portion was provided on the side and the lower side.

According to the present invention, it is possible to prevent the transfer roller of the transfer roller unit from falling down in the direction in which the transfer roller comes into contact with the desk top surface without increasing the size of the apparatus. Thus, an image forming apparatus that can ensure quality and safety can be realized.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is an image forming apparatus for forming an image on a sheet by an electrophotographic method, wherein a toner image formed in an image forming process section is transferred onto the sheet. Supporting parts supporting both ends of the roller,
A projection is formed integrally with a handle member that is held when the transfer roller is attached and detached, and is provided on the transfer position side and below the action line passing through the center of gravity of the transfer roller when the handle member is supported by hand.

According to a second aspect of the present invention, the shape of the supporting portion is
A part of the transfer position side is a radius R1 with respect to an action line passing through the center of gravity of the transfer roller when the handle member is supported by hand, and a part of the transfer position side and a lower part of the radius below the action line of the center of gravity is also a radius R.
Third, the other portions have a shape of a substantially radius R2, and when the radius of the transfer roller is R0, the relationship of R1 <R0 <R2 <R3 is satisfied.

[0010] With the above configuration, it is possible to prevent the transfer roller of the transfer roller unit from falling down in the direction in which the transfer roller contacts the desk surface or the like without increasing the size of the apparatus. An image forming apparatus that can ensure safety can be realized.

Hereinafter, embodiments of the present invention will be described. FIG. 1 is an overall configuration diagram of a printer according to an embodiment of the present invention, FIG. 2 is a perspective view of a transfer roller unit according to an embodiment of the present invention, and FIG. FIGS. 4 and 5 show the handling state of the transfer roller unit according to the embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a printer main body.
To form a yellow image, a drum-shaped photoconductor 3 having an electrostatic latent image formed on its peripheral surface by a laser beam from an exposure device 2, a charging device 5 for charging the drum, and toner adhered to the photoconductor 3 The developing unit 4 includes a developing unit 4 that visualizes the electrostatic latent image to form a latent image, and a cleaner 6 that removes residual toner on the photoconductor 3 after transferring the toner image to the intermediate transfer belt 8. Other color magenta, cyan, and black image formations have the same configuration.

In the image forming section, the intermediate transfer belt 8
The toner images on the intermediate transfer belt 8 are transferred onto the sheet P conveyed from the sheet cassette 10 by the transfer roller 12, and then the sheet P passes through the fixing device 13. The toner is fixed, and is discharged to a paper discharge tray 17 by a pair of paper discharge rollers 14 and 15. The residual toner on the intermediate transfer belt 8 that has been transferred to the paper P is cleaned and removed by the cleaning unit 9.
Since the electrical characteristics of the transfer roller 12 gradually deteriorate as the number of prints advances, the transfer roller 12 needs to be replaced as a consumable item over its life.

The transfer roller 12 is incorporated in the transfer device A, and the transfer device A can be opened in the direction C with the support shaft 19 as a fulcrum. In the open state, the transfer roller unit B can be taken out of the transfer device A. In FIG. 2, a transfer roller unit B includes a holder B-1 including a handle B-6 that is held by an operator when attaching and detaching the transfer roller unit B on shafts 12-1 protruding from both ends of the transfer roller 12. It is provided rotatably. On one side of the transfer roller 12, a gear 1 for rotating the transfer roller 12 during a printing operation is provided.
2-2 are provided.

FIG. 3 shows the transfer roller 12 connected to the printer body 1.
2 shows the vicinity of the transfer roller 12 when the transfer roller 12 is mounted.
A lower portion of the holder B-1 is a support portion B-2 for supporting the transfer roller 12, and the support portion B-2 has a substantially circular shape along the circumference of the transfer roller 12.

Here, the radius of the transfer roller 12 is R0. When the transfer roller unit B is mounted on the printer main body 1, the supporting portion B-2 is provided with a concave portion B-4 having a radius R1 on the intermediate transfer belt 8 side, that is, on the transfer position side so as not to contact the intermediate transfer belt 8. And R1 <R0. In the support portion B-2, a radius R
3 are provided, and the radius R of the other outer portion is provided.
2 and R3> R2.

The radius R2 portion, when placed on the desk D,
R2> R so that the transfer roller 12 does not contact the upper surface of the desk D.
0. Therefore, the relationship of each radius dimension is R1 <R
The outer shape of the support portion B-2 is formed so that 0 <R2 <R3. The protrusion B-5 is a fixing hook used to prevent the holder B from rotating when the transfer roller unit B is mounted on the transfer device A.

FIG. 4 shows a state in which the transfer roller unit B is handled by an operator. When the operator holds the handle B-6 with the hand C, the line of gravity L acting on the transfer roller unit B substantially passes through the center position of the transfer roller 12. When the transfer roller unit B is to be placed on the desk D as shown in FIG. 4, the transfer roller unit B has a convex portion B-3 below the transfer line side from the action line L of the center of gravity.
And does not fall in the direction b, which contacts the upper surface of the desk D. FIG. 5 shows a state in which the transfer roller unit B has fallen in the direction a. At this time, since the radius R2 of the support portion B-2 that contacts the upper surface of the desk D is larger than the radius R0 of the transfer roller 12, the surface of the transfer roller 12 does not contact the desk D.

[0019]

As described above, according to the present invention, when the transfer roller 12 is replaced by an operator, the transfer roller is grounded on the desk surface, and the surface is scratched or dust adheres. Therefore, the quality and safety of the replacement work by the operator can be ensured without increasing the size of the apparatus and without increasing the cost.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a printer according to an embodiment of the present invention.

FIG. 2 is a perspective view of a transfer roller unit according to the embodiment of the present invention.

FIG. 3 is a configuration diagram around a transfer roller in one embodiment of the present invention.

FIG. 4 is a handling state diagram of the transfer roller unit according to the embodiment of the present invention.

FIG. 5 is a handling state diagram of the transfer roller unit according to the embodiment of the present invention.

FIG. 6 is a handling state diagram of a conventional transfer roller unit.

FIG. 7 is a state diagram when a conventional transfer roller unit falls down.

[Explanation of symbols]

 B Transfer Roller Unit B-1 Holder B-2 Support B-3 Convex B-4 Concave B-5 Convex 12 Transfer Roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidehiko Inoguchi 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Terms (reference) 2H032 AA05 BA19 BA23 BA30 3J103 AA02 AA90 FA09 FA16 FA30 GA02 GA57 GA58 GA60

Claims (2)

[Claims] An image forming apparatus for forming an image on a sheet by an electrophotographic method, wherein a supporting portion for supporting both ends of a transfer roller for transferring a toner image formed by an image forming process section onto the sheet is provided. The handle is formed integrally with a handle member that is held when the transfer roller is attached and detached, and when the handle member is supported by hand, a convex portion is formed at a transfer position side and a lower side from an operation line passing through the center of gravity of the transfer roller. An image forming apparatus, comprising: 2. The shape of the support portion is such that a part on the transfer position side has a radius R1 with respect to an action line passing through the center of gravity of the transfer roller when the handle member is supported by hand, A part on the lower side of the transfer position has a radius R3, and the other part has a substantially radius R2. When the radius of the transfer roller is R0, the relationship is such that R1 <R0 <R2 <R3. The image forming apparatus according to claim 1, wherein: