JPH08137324A - Paper separating mechanism for fixing device - Google Patents

Abstract

PURPOSE: To provide the paper separating mechanism of a fixing device which prevents an operator from inadvertently touching a hot heat roller surface and getting burned at the time of removing jammed paper and prevents him from touching the pawl part of a separating pawl and being injected at the time of touching the hot heat roller surface and unintentionally pulling back a hand. CONSTITUTION: This mechanism is provided with a link 8 having one end part pivotally supporting one end part freely rotatably supported by a fixing member 13 positioned at an upper part on a paper inserting side against a roller press- contacting position and the other end part of the separating pawl 9 to be freely rotatable, a first bias spring 10 spread between the one end part of the link 8 and the fixing member 13 and energizing the link 8 in the direction of an arrow E, a stopper 12a stopping the energized link 8 at a position where it does not abut on the heat roller surface and a second bias spring 11 spread between the other end part of the link 8 and the one end part of the separating pawl 9 and energizing the separating pawl 9 in the direction of the arrow D and making the pawl part 9b abut on the heat roller surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an electrophotographic printer or the like, and more particularly to a sheet separating mechanism for separating a sheet attached to a heater roller surface.

[0002]

2. Description of the Related Art Conventionally, an electrophotographic printer or the like is provided with a fixing device having a heat roller and a pressure roller which are in pressure contact with each other with a paper conveying path interposed therebetween, and a paper to which a toner is attached is attached. When the sheet is conveyed along the sheet conveying path, the toner is heated and pressure-bonded to the sheet. In the fixing device, one end of the fixing roller is rotatably supported so that the paper adhering to the heater roller surface is separated from the heater roller surface, and the other end of the claw portion is supported by the heater roller surface. There is provided a sheet separating mechanism having a separating claw that is brought into contact with the sheet.

[0003]

In the conventional sheet separating mechanism of the fixing device, when the sheet is separated from the heater roller and jams, the sheet is clogged like a bellows, so that the operator cannot separate the sheet. Rotate the claw around one end of the paper to expand the space between the separation claw and the paper transport path to remove the accordion-shaped paper, but accidentally touch the hot heater surface and get burned. Hot hot
There is a problem in that when the hand comes in contact with the roller surface and the hand retracts unexpectedly, the finger may come into contact with the claw portion of the separating claw, resulting in injury.

According to the present invention, when an operator removes a jammed sheet, he / she accidentally touches the hot heater surface to get burned, or touches the hot heater surface to make a hand. An object of the present invention is to provide a sheet separating mechanism of a fixing device that prevents a person from being injured by coming into contact with a claw portion of a separation claw when it is unexpectedly retracted.

[0005]

In order to achieve the above object, in the sheet separating mechanism of the fixing device of the present invention, the other end of the separating claw is provided so as to be movable along the locus of the heater roller surface. It is a thing.

[0006]

In the sheet separating mechanism constructed as described above, when the sheet is separated from the heater roller and then jams, the separating claw is accordion-likely clogged between the separating claw and the conveying path. The paper is pushed up to widen the space between the separation pawl and the paper transport path, and at this time, the pawl portion of the separation pawl moves along the locus of the heater roller surface.

Therefore, according to the present invention, when the operator removes the jammed paper, the operator accidentally touches the hot heater surface and is burned, or the hot heater surface is burned. It is possible to prevent injuries due to contact with the claw portion of the separation claw when the user comes in contact with the hand and involuntarily retracts it.

[0008]

Embodiments of the present invention will be described with reference to the drawings. Elements common to the drawings are given the same reference numerals.

FIG. 1 is a schematic diagram showing a schematic configuration of the embodiment. The fixing device 1 has a heat roller 2 and a pressure roller 3, and the pressure roller 3 is brought into pressure contact with the heat roller 2 with a sheet conveying path 4 in between. A halogen lamp 5 as a heat source for heating the surface of the heater roller is provided inside the heater roller 2, and each of the sheets 6 conveyed in the direction of arrow A along the sheet conveyance path 4 is indicated by an arrow B. , Heater that rotates in the C direction
The toner 2 adhered to the paper 6 is thermocompression-bonded by pressure contact between the roller 2 and the pressure roller 3. The fixing device 1 includes a link 8, a separation claw 9, a first bias spring 10 and a second bias spring 11, and a paper separating mechanism 12 for separating the paper 6 attached to the heater roller surface. A plurality of them are provided at substantially equal intervals along the axial direction of the heat roller 2 or at intervals according to the paper width of the paper 6.

The link 8 is rotatably supported at one end by a support shaft 14 provided on a fixing member 13 located on the upper side of the sheet insertion side with respect to the roller pressure contact position, and has a separating claw 9 at the other end. A recess 16 is provided to rotatably support the support shaft 15 provided at the one end 9a. The separation claw 9 is urged in the direction of arrow D by a second bias spring 11 stretched between the link 8 and one end 9a of the separation claw 9 as shown by the broken portion of the link 8, and the other end is separated. The claw portion 9b of the above is in contact with the roller surface of the heat roller 2. The link 8 is biased in the direction of arrow E by a first bias spring 10 stretched between the link 8 and the fixing member 13. The fixing member 13 is provided on a frame (not shown), and the link 8 is brought into contact with the protruding stopper 13a.

The biasing force of the first bias spring 10 is stronger than that of the second bias spring 11,
The link 8 has such strength that the link 8 is not easily rotated in the direction of the arrow F by the reaction force of the bias spring 11 of FIG.
It is set so that the link 8 can be easily rotated in the arrow F direction when is jammed like a bellows.

FIG. 2 is an explanatory diagram for removing a paper jammed paper. When the paper sheet 6 is separated from the roller surface of the heat roller 2 and then jammed, the separation claw 9 is separated.
And the conveyance path 4 are pushed up by the sheet 6 that is accordion-shaped and is rotated in the direction of arrow D, and the link 8 is rotated in the direction of arrow F so that the space between the separation claw 9 and the sheet conveyance path 4 is increased. spread. At this time, the claw portion 9a of the separation claw 9 moves along the locus of the roller surface of the heat roller 2.

The operator can see that the separating claw 9 and the sheet conveying path 4 are widened.
Insert a hand between and to remove the paper sheet 6 which is jammed in a bellows shape. Further, the claw portion 9a of the separation claw 9 is a roller of the heat roller 2.
Since it is in contact with the flat surface, there is no possibility of injury by touching the claw with your hand.

In this embodiment, the support shaft 15 provided at one end 9a of the separation claw 9 is rotatably supported by the recess 16 provided at the other end of the link 8, but as shown in FIG. The other end 21 of 20 may be extended to a position further away from the position of the support shaft 15. In this case, since the paper sheet 6 which is jammed in a bellows shape also pushes up the link 20, it becomes easy to remove the jammed paper sheet 6.

[0015]

Since the present invention is configured as described above, it has the following effects.

When a sheet is separated from the heater roller and then jams, the separating claw is pushed up by the sheet clogged between the separating claw and the conveying path to separate the separating claw and the sheet conveying path. Since the claw part of the separating claw is moved along the locus of the heat roller surface, the operator accidentally touches the hot roller surface and is burned. It is possible to prevent injuries due to contact with the claws of the separation claws when the hand comes in contact with the hot heater surface and withdraws the hand unintentionally.

Further, when the sheet is accordion-shaped jammed between the separating claw and the conveying path, the claw portion of the separating claw is pressed against the heater roller surface by the sheet, but since the separating claw is pushed up, the claw portion is pushed up. Can be prevented from being damaged.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of an example.

FIG. 2 is an explanatory diagram for removing a sheet that has caused a paper jam.

FIG. 3 is a schematic diagram showing a modified example.

[Explanation of symbols]

 1 Fixing Device 8 Link 9 Separation Claw 10 First Bias Spring 11 Second Bias Spring 12 Paper Separation Mechanism

Claims (2)

[Claims] 1. A sheet to which a toner is attached is conveyed along a sheet conveying path, and the toner is heated to the sheet by a heater roller and a pressure roller which are in pressure contact with each other across the sheet conveying path. A fixing device that separates the paper adhering to the heater roller surface with a separation claw that crimps and pivotally supports one end and rotatably supports the other end claw portion against the heater roller surface. In the sheet separating mechanism, the claw portion of the separating claw is provided so as to be movable along the trajectory of the heater roller surface, and the sheet separating mechanism of the fixing device. 2. One end portion rotatably rotatably supported by a fixed portion located above the sheet insertion side with respect to the roller pressure contact position and the other end portion rotatably rotatably supported by one end portion of the separation claw. A first bias spring extending between one end of the link and the fixed portion to urge the link toward the heater, and the biased link to the heater. A stopper that stops at a position where it does not abut against the roller surface, and a tension member that is stretched between the other end of the link and one end of the separating pawl so that the pawl portion of the separating pawl comes into contact with the heater surface. 2. The sheet separating mechanism of the fixing device according to claim 1, further comprising a bias spring.