JPH0234699Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a fixing device, in particular, a sheet on which an image has been recorded using an electrostatic recording method is passed between a pair of fixing rollers to fix the image. The present invention relates to a fixing device.

[Prior art]

Generally, in a fixing device, a sheet separation claw is provided in contact with the fixing roller in order to separate the sheet that has passed between the fixing rollers from the fixing roller, but conventionally, the sheet separation claw is in contact with the fixing roller. Many of them cannot be released from the set position, and those that can be released are done using complicated release mechanisms.

However, in such conventional cases,
If the sheet separation claw cannot be released, it has the disadvantage that it takes time and effort to dispose of a sheet jam if it occurs, and if the sheet separation claw can be released, the release mechanism is complicated. Therefore, the number of parts increases, and the precision of positioning the sheet separation claw when setting the sheet to the set position is disadvantageous. Furthermore, in the past, when the recording paper was wrapped around the fixing or pressure roller, the sheet separation claws got in the way, making it difficult to remove the recording paper.

[Purpose of invention]

This invention eliminates the drawbacks of conventional devices such as seki, and uses a simple mechanism to separate the sheet separation claw from the fixing roller in one motion. An object of the present invention is to provide a fixing device that can accurately position the fixing device.

[Structure of the idea]

This invention is based on a fixing device that passes a sheet on which an image has been recorded using an electrostatic recording method between a pair of fixing rollers to fix the image, and then discharges the sheet via a pair of sheet discharge rollers. A support shaft is provided parallel to the axial direction of the fixing roller and the pair of sheet ejection rollers, a sheet separation claw is provided on the support shaft so as to be able to contact one of the fixing rollers, and one of the sheet ejection rollers is rotatably supported. A machine frame is provided on the support shaft, a recess is formed in the sheet separation claw, a release arm is formed in the sheet ejection guide member fixed to the machine frame, and the release arm can be placed in the recess. , connecting the sheet ejection guide member and the sheet separation claw with a biasing member;
In conjunction with the rotational movement of the sheet ejection guide member about the support shaft, the release arm engages with the recess to isolate the sheet separation claw from the fixing roller, and one of the sheet ejection rollers It has a configuration in which it is isolated from the other sheet ejection roller.

[Example of idea]

Embodiments of this invention shown in the drawings will be described below.

1 to 3 show a fixing device according to this invention, which is equipped with a pair of upper and lower fixing rollers 1 and 2 that are in pressure contact with each other, and is equipped with a pair of upper and lower fixing rollers 1 and 2 that are used to record images on transfer paper or the like using an electrostatic recording method. Sheet (not shown)
is conveyed in the direction of the arrow in FIG.
When the sheet passes between the fixing rollers 1 and 2, the image is fixed on the sheet by heat from a heat source provided in the fixing roller 1 and pressure from both the fixing rollers 1 and 2.

A support shaft 3 is provided on the sheet discharge side of the fixing roller 1, and a plurality of sheet separation claws 4 are provided on this support shaft 3.
and a sheet discharge guide stay 5 are each rotatably attached around the support shaft 3. The sheet separating claw 4 has a claw portion 4a formed at the lower end of the front surface facing the fixing roller 1, and a sheet guide arm 6 and an engagement arm 7 are formed above and below a recess 8 on the back side. Sheet discharge guides 9 are fixed to the sheet discharge guide stay 5 at positions corresponding to the sheet separation claws 4, and sheet discharge guides 11 are fixed to the positions corresponding to the lower sheet discharge rollers 10. A release arm 12 that enters into the recess 8 of the sheet separation claw 4 is formed at the sheet separation claw 4, and a spring 13 as a biasing member is tensioned between the release arm 12 and the top of the sheet separation claw 4. A sheet guide arm 14 is formed, and an upper sheet discharge roller 15 that is in circumferential contact with the lower sheet discharge roller 10 is rotatably attached. As shown in the figure, the support shaft 3 is connected to a pair of fixing rollers 1 and 2 and a pair of sheet ejection rollers 1.
It is parallel to the axial direction of 0 and 15.

Note that 16 is a sheet guide.

Next, the operation of the above will be explained.

First, in a regular use state, the sheet ejection guide stay 5 is placed at a position where the upper sheet ejection roller 15 comes into circumferential contact with the lower sheet ejection roller 10 by means such as a stopper (not shown), and at this time, the sheet separation claw 4 is moved by a spring. By the tensile force of 13, the claw portion 4a
is in contact with the circumferential surface of the fixing roller 1 with a predetermined pressure. As a result, when a sheet on which an image has been recorded using the electrostatic recording method enters between fixing rollers 1 and 2 and is sent out to the ejection side while the image is fixed by heat and pressure, the sheet sticks to the fixing roller 1. The leading edge of the sheet is separated from the fixing roller 1 by the claw portion 4a of the sheet separation claw 4, and is guided vertically by sheet discharge guides 9, 11 and sheet guide 16 to the lower sheet discharge roller 10. and the sheet discharge upper roller 15.

Furthermore, in the event of an abnormality such as sheet jamming or during inspection, the sheet ejection guide stay 5 may be raised by rotating upward about the support shaft 3. In this way, the sheet discharge guides 9 and 11 fixed to the sheet discharge guide stay 5 and the sheet discharge upper roller 15 attached to the sheet discharge guide 11 rotate upward together with the sheet discharge guide stay 5 and open. In conjunction with this, the release arm 12 of the sheet ejection guide 9 releases the sheet separation claw 4.
The sheet separating claw 4 engages with the lower surface of the engaging arm 7 to lift the sheet separating claw 4 upward, so the sheet separating claw 4 rotates upward around the support shaft 3, so that the claw portion 4a touches the circumferential surface of the fixing roller 1. The claw portion 4a is thereby separated from the claw portion 4a.
is released from contact with the fixing roller 1. Therefore, the recording paper wrapped around the fixing roller or the like can be easily removed without being disturbed by the separating claw.

Further, in order to eliminate an abnormal state such as a jam or to return from a released state to a normal state at the end of an inspection, the sheet ejection guide stay 5 may be rotated downward about the support shaft 3 and folded down. In this way, the rotation of the sheet discharge guide stay 5 stops at the position where the upper sheet discharge roller 15 and the lower sheet discharge roller 10 circumferentially contact each other, and the sheet separation claw 4 is rotated by the tension force of the spring 13 so that the claw portion 4a is The fixing roller 1 is brought into contact with the pressure at a predetermined position on the circumferential surface of the fixing roller 1 and is stopped, thereby becoming in a steady state of use.

In the above embodiment, the sheet separating claw 4 is provided on the fixing roller 1 side, but the invention is not limited to this. For example, in the case where the sheet tends to stick to the fixing roller 2, the separating claw 4 may be provided on the fixing roller 2 side. Of course, the sheet ejection guide stay 5 may also be rotatably attached not to the support shaft 3 but to an appropriate location on the machine frame.

[Effect of idea]

By configuring this idea as described above,
The sheet separation claw can be separated from the fixing roller as needed, making it easy and quick to deal with sheet jams and inspections.In addition, a simple connection mechanism allows the sheet separation claw to be moved away from the fixing roller. Since the nail can be separated from the fixing roller, the nail separation operation is reliable. As a result, the number of parts can be reduced, and furthermore, the sheet separating claw can be accurately positioned when it comes into contact with a predetermined position of the fixing roller, which has excellent effects.

[Brief explanation of drawings]

The drawings show an embodiment of this invention, with FIG. 1 being a schematic layout diagram showing the set state, FIG. 2 being a schematic layout diagram showing the released state, and FIG. 3 being a perspective view of the main parts. 1, 2... Fixing roller, 3... Support shaft, 4... Sheet separation claw, 4a... Claw portion, 5... Sheet discharge guide stay, 6, 14... Sheet guide arm, 7...
...Engagement arm, 8...Recess, 9, 11...Sheet discharge guide, 10...Sheet discharge lower roller, 12...
Release arm, 13... Spring, 15... Sheet discharge upper roller, 16... Sheet guide.

Claims (1)

[Scope of utility model registration request] In a fixing device that passes a sheet on which an image has been recorded by an electrostatic recording method between a pair of fixing rollers to fix the image, and then discharges the sheet via a pair of sheet discharge rollers, the pair of fixing rollers and the A support shaft is provided parallel to the axial direction of the pair of sheet ejection rollers, and a seal separating claw is provided on the support shaft so as to be able to contact one of the fixing rollers. A recess is formed in the sheet separation claw provided on the support shaft, and a release arm is formed in the sheet ejection guide member fixed to the machine frame, and the release arm is disposed within the recess, and the sheet ejection A biasing member connects the guide member and the sheet separation claw, and the release arm engages with the recess in conjunction with the rotational movement of the sheet ejection guide member about the support shaft. A fixing device characterized in that the sheet separation claw is separated from the fixing roller, and one sheet ejection roller is separated from the other sheet ejection roller.