JPH036584A - Image forming device - Google Patents

Abstract

PURPOSE:To easily perform jam processing by releasing a pressure roller from being pressed associatively with the rotation of an image forming frame in its opening direction. CONSTITUTION:A device main body 10 is provided with a pressure application release member 32 which releases the pressure roller 22 from being pressed associatively with the opening-directional rotation of the rotatable image forming frame 30. Namely, when the image forming frame 30 is rotated in the opening direction, its lever operating projection part 35 engages the upper end part 32a of a pressure application release lever 32, which is rotates as shown by an arrow C. This rotation lowers the pressure roller 22 from a solid-line position to a chain-line position and the roller 22 leaves a fixing roller 21. Consequently, jamming paper is easily removed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image forming apparatus that forms an image on paper using an electrophotographic process, such as a printer using a laser, a copying machine, or a facsimile.

Conventionally, in the image forming apparatus described in, for example, Japanese Utility Model Application Publication No. 61-81660, a transfer/separation charger and a conveyance unit are attached to a swinging body in order to facilitate the removal of jammed paper. is pressed by a suppressing member to set the conveyance unit at the conveying position, and when a jam is cleared, the release lever releases the pressure on the suppressing member and at the same time releases the pressure on the pressure roller of the fixing device.

However, although such a release mechanism can be applied to image forming apparatuses equipped with a transport unit, especially small image forming apparatuses do not have an equivalent transport unit and the transport path is fixed. , so it cannot be applied.

An object of the present invention is to facilitate jam processing without such problems.

SUMMARY OF THE INVENTION The present invention is an image forming frame that is rotatable with respect to the main body of an image forming apparatus, and all or part of electrophotographic process equipment such as a developing device, a photoreceptor, and a cleaning device can be attached and detached. In an image forming apparatus that fixes an image by sandwiching a recording paper between a fixing roller and a pressure roller of a fixing device, the pressure roller is applied in conjunction with the rotation of the image forming frame in the opening direction. It is characterized by comprising a pressure release member for releasing pressure. The image forming apparatus is also characterized in that it includes a drive release member that releases the drive system of the fixing roller in conjunction with the rotation of the image forming frame in the opening direction.

Raw--1 When the image forming frame is rotated in the opening direction, the pressure on the pressure roller of the fixing device is released. Alternatively, the drive system of the fixing roller is also released. Then, the paper is released from being held between the pressure roller and the fixing roller, and the fixing roller becomes free.

叉-凰 all at once Next, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 5 is a schematic sectional view of a laser printer according to the present invention.
10 in the figure is the main body upper unit 10a and the main body lower unit 10.
With the printer body divided into b.

The upper main unit 10a is releasably hinged to the lower main unit 10b as shown in FIG. 11 is a paper feed cassette loaded into the printer main body 10. The recording paper 50 fed in the direction of the arrow from the paper feed cassette 11 by the paper feed roller 12 is timed by a pair of registration rollers 13 and placed under a drum-shaped photoreceptor 14 which is a latent image carrier. transported to the side. Photoreceptor 14
is rotated clockwise, and at this time the charger 15
The surface of the photoreceptor 14 is charged and irradiated with laser light from the laser optical system 16 to form an electrostatic latent image on the photoreceptor 14 . This latent image is made visible by toner when passing through the developing device W117, and at the same time, this visible image is transferred by the transfer/separation charger 18 to the lower surface of the recording paper 50 that has been conveyed onto the photoreceptor 14. The recording paper 50 that is in close contact with the photoreceptor 14 is electrostatically separated. The recording paper 50 is guided by the conveyance guide 19 and then moved to the fixing roller 21 of the fixing device 120.
and the pressure roller 22, and the visible image is fixed while being pressed. Then, the recording paper 5 that has come out of the fixing device 20
0 is discharged by the paper discharge roller 23 to the paper discharge section 24 in the direction of arrow B. On the other hand, the photoreceptor 14 after the visible image transfer is cleaned by a cleaning device! The residual toner is removed by a cleaning blade 26 having an elasticity of 26 mm. The removed toner is collected into a toner collection tank 28 by a toner collection member 27. The charger 15, the developing device 17, and the cleaning device 25 are supported by a box-shaped image forming frame 30. This image forming frame 30 consists of 1 main body lower unit 1
For 0b, fixing device! It is pivotally mounted near 20 so as to be rotatable around a fulcrum pin 29. As shown in FIG. 6, when removing the jammed recording paper 50, the upper unit 10a of the main body is opened, and then the image forming frame 30 is opened.

When the image forming frame 30 is opened, the fixing device is activated as follows. At the same time that the pressure on the pressure rollers 22 of 20 is released, the drive system of the fixing roller 21 is also released.

That is, the lower unit 10b is provided with a pressure release lever (pressure release member) 32 that is rotatable about a fulcrum 31, as shown in FIG.

A long hole 33 is provided at the bent lower end of the pressure release lever 32.
is provided, and the shaft 34 of the pressure roller 22 is fitted into the elongated hole 33. On the other hand, a lever operating protrusion 35 that can be engaged with the upper end 32a of the pressure release lever 32 is protruded from the side surface of the image forming frame 30.
When o is rotated in the opening direction, the lever operating protrusion 35
engages with the upper end 32a of the pressure release lever 32, and the pressure release lever 32 is rotated in the direction of arrow C in FIG.

Due to this rotation, the pressure roller 22 is lowered from the solid line position in FIG. 2 to the chain line position, and is separated from the fixing roller 21. Note that if such a pressure release mechanism is provided on both sides of the pressure roller 22, its operation will be more reliable than when it is provided only on one side.

On the other hand, FIGS. 3 and 4 show other embodiments. That is, the lower unit fob of the main body is provided with a gear frame 37 that swings about a gear shaft 36 as a fulcrum, as shown in FIG. This gear frame 37 includes a transmission gear 39 that meshes with a gear 38 at one end of the fixing roller 21.
, and a drive gear 40 that meshes with the transmission gear 39 are supported by bearings. The gear frame 37 is the transmission gear 3
9 is urged counterclockwise in FIG. 3 by a spring 41 to engage the gear 38.

A drive release lever (drive release member) 42 is integrally provided on the gear frame 37 in a protruding manner. on the other hand.

A lever operating protrusion 43 that can engage with the upper end 42a of the drive release lever 42 is provided on the side surface of the imaging frame 30.
When the first image forming frame 30 on which is protruded is rotated in the opening direction, the lever operating protrusion 43 engages the drive release lever 4.
2, and the drive release lever 42 and gear frame 37 are rotated in the direction of the arrow in FIG.

Due to this rotation, the transmission gear 39 is displaced from the solid line position in FIG. 4 to the chain line position and is separated from the gear 38, and the fixing roller 21 becomes free (free to rotate).

Therefore, when the image forming frame 30 is opened to take out the jammed paper, the pressure applied by the pressure roller 22 is released from the jammed paper. Alternatively, when pulling out the jammed paper, the fixing roller 21 can rotate freely with little resistance, so the jammed paper can be easily removed.

According to the present invention, when the image forming frame is released, the pressure roller is automatically released from the pressure roller, or the fixing roller is automatically released from the drive system and can rotate freely. Therefore, jammed paper can be easily removed. Compared to releasing the pressing force of the pressure roller, which has a relatively high load, releasing the fixing roller from the drive system has the advantage that the operating force of one operating frame is smaller.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a mechanism for releasing the pressure on the pressure roller of the fixing device in the image forming apparatus according to the present invention, FIG. 2 is a side view showing its operation, and FIG. 3 is a release of the drive system of the fixing roller. Fig. 4 is a side view showing its operation;
FIG. 5 is a schematic sectional view of a laser printer as an example of the image forming apparatus, and FIG. 6 is a perspective view showing a state in which jammed paper is removed. 10...Printer body 14...Photoreceptor 17...Developing device 20...Fixing device 21. ...... Fixing roller 22 ...... Pressure roller 25 ...... Cleaning device 30 ...
...Image forming frame 32...Press release lever (pressure release member) 37...Gear frame 38...
...Gear 39 of the fixing roller...
Transmission gear 40... Drive gear

Claims (1)

[Scope of Claims] 1. An image forming frame that is rotatable with respect to the main body of the image forming apparatus and supports all or part of electrophotographic process equipment such as a developing device, a photoreceptor, and a cleaning device, while supporting a fixing device. In a surface image forming device that fixes an image by sandwiching a recording paper between a fixing roller and a pressure roller, the pressure roller is released from pressure in conjunction with the rotation of the image forming frame in the opening direction. An image forming apparatus comprising a pressure release member. 2. An image forming frame that is rotatable relative to the main body of the image forming apparatus and supports all or part of the electrophotographic process equipment such as the developing device, photoreceptor, and cleaning device, while also supporting the fixing roller of the fixing device and applying pressure. An image forming apparatus that fixes an image by sandwiching a recording sheet between the rollers, further comprising a drive release member that releases the drive system of the fixing roller in conjunction with rotation of the image forming frame in an opening direction. An image forming apparatus.