JPS608872A - Fixing device - Google Patents

Abstract

PURPOSE:To prevent a body to be fixed from being stained during the restarting of operation after a machine halt by separating a supply body which supplies oil in contact with a fixing body from the fixing body by an escaping mechanism unless fixation is in process. CONSTITUTION:A couple of upper and lower rollers 25 and 26 as the fixing body are pressed against each other by a spring 27, and felt 28 as the supply body which supplies oil in contact with the upper roll 25 is supported rotatably on a frame 30 by a holder 29. The felt 28 is pressed against the roller 26 during fixation to coat the surface of the roller 25 with the oil, and an image is fixed by pressure onto transfer paper which passes between the rollers 25 and 26, but the felt 28 leaves the roller 25 through the escaping mechanism a unless the fixation is in process, so the roller 25 is neitgher impregnated with the oil nor stained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a fixing device provided in, for example, an electrophotographic camera.

[Technical background of the invention and its problems]

This type of fixing device is known, for example, as shown in FIG. That is, 1.2 in the figure is a pair of rollers that are in pressure contact with each other, and a pressure of about 30 h/cm is applied between these rollers 1 and 2 due to the biasing force ζ of the spring 3. The copy paper, on which the image has been transferred by a photoreceptor (not shown), is conveyed by the conveyance path 4 between the rollers 1 and 2, and the undetermined toner is fixed thereon by pressure. This fixed single copy paper is discharged to a paper discharge tray 6 by paper discharge rollers 5, 5.

By the way, when you put on your feet, powdered toner is not necessarily 1
00% may be transferred to the HB roller 1 without adhering to the copy paper. This phenomenon is called offset. As a means to prevent this offset, it is common practice to apply silicone oil to the roller 71. When applying this silicone oil, for example, a felt 7 impregnated with silicone oil is brought into sliding contact with the roller 1 to constantly supply a small amount of silicone oil onto the roller 1, thereby preventing offset.

However, in the past, when the felt 7 became dirty after making many copies, when the machine was stopped for about a day and restarted, some of the dirt on the felt 7 would stick to the roller II. , there was a drawback that band-like stains appeared on the next copy. Also, if the felt 7 is impregnated with a large amount of oil, the oil may leak into the roller 1 while the felt 7 is at rest for a while.
There was also the inconvenience that the oil oozed out and the tip of the missing copy got wet.

[Purpose of the invention]

The present invention was made with a view to the above-mentioned I-111 blue, and its purpose is to provide a constant M which can prevent the target body from becoming dirty when the robot is operated. The device is intended to be used in four different voices.

[Invention, 11! , ': In order to achieve the above 61-1 purpose, the supply body that contacts the constant M body and supplies oil is separated from the fixing body by a relief mechanism during non-constant abrasion.

[Embodiments of the invention]

The present invention will be described below with reference to an embodiment not shown in FIGS. 2 to 5. In the figure, reference numeral 11 denotes a main body of an electronic close-up photographing machine, and a photosensitive drum 12 is provided within this main body 11. Along the rotational direction of the photosensitive drum 12, a charger 13, a developing device 14, and a transfer charger 15 are arranged around the photosensitive drum 12.
, a peeling charger J6, and a cleaning device 17 are provided. Further, a paper feed cassette 18 is provided at the lower part of one side of the main body 11, and a transfer paper 19 is stored in this paper feed cassette 18. The transfer paper 19 is taken out one by one by a paper feed roller 20. 21 is a first conveyance section that conveys the transfer paper 19 toward the photosensitive drum 12, and 22 is a second conveyance section that conveys the transfer paper 19 on which the image has been transferred. A fixing device 23 and a paper discharge roller 24 are provided in the second conveyance section 22 . 45 is a paper ejection tray 1/y. The fixing device 23 is constructed as shown in detail in FIG. 3 and 11. That is, in the figure, 25 and 26 are a pair of upper and lower rollers as a fixing body, and these rollers 25 and 26 are supported by a spring 27.
are pressed against each other. Further, 28 is in contact with the upper roller 25 and oil 9.1fj:
Felt 28 is used as a supply body, and this felt 28 is released from the upper roller 25 by a release mechanism A. Of course, felt 28 is holder 2
94, therefore, +41, and this holder 29 (supports the frame so as to be rotatable) is 1.
F, 3 is a lever for great distance, this 1/bar 31 for contact and separation
The upper part 51 is rotatably supported on the frame 30 via a shaft 32. The tips of the holder 29 and the lever 31 for contact and separation are fitted into each other as shown in Figure 4.
U-shaped bent portions 31a, 31a are formed at both ends of the tip of the handling lever 31, and the holder 29
A curved protruding piece 29a is formed at the center of the tip. The protruding piece 29a of the holder 29 is engaged with the central upper surface of the approach/separate lever 31, and the bent portions 31a, 31a of the approach/separate lever 31 are engaged with the upper surface portions of both sides of the approach/separate lever. It is now stopped. Further, one end portion of the shaft 32 of the upper surface 'applying/separating lever 31 projects from the frame 30 as shown in FIG. 4, and a lever 33 is fixed to this projecting portion. One end of this lever 33 is connected to a pin body 35 via a return spring 34, and the other end is connected to a solenoid 371 via a spring 36. The solenoid 37 is turned on when the image is fixed on the transfer paper 19, and turned off when the image is not fixed.

In the above configuration, when forming an image, the charger 13ζ charges the top of the photoreceptor tram 12, and an electrostatic latent image is formed on the photoreceptor drum 12 through an exposure system (not shown). The latent image is visualized by supplying toner with the developing device 14. On the other hand, at this time, the transfer paper 9 is taken out from the paper feed cassette 18 and sent between the photosensitive drum 12 and the transfer charger 15 via the first conveying section 2. Here, the developed image on the photoreceptor drum 12 is transferred to a transfer paper 19 by the action of the transfer charger 15, and the transfer paper 19 is peeled off from the photoreceptor drum 12 by the action of the peeling charger 16. The transfer paper 19 on which the image has been transferred is transferred to the second conveyance section 2.
2 to the fixing device 23.

At this time, the solenoid 37 of the fixing device 23 is turned on, and the lever 33 is rotated counterclockwise via the spring 36 against the force of the return spring 34.

As a result, the approaching/separating lever 31 is rotated via the shaft 32, and the opening-shaped bent portion at the tip thereof is rotated. 1 a,
31a, the tip 29a of the holder 29 is pushed down, and the felt 28 is pushed down to the L position as shown in FIG. 5(b).
It is pressed against the roller 25. This pressure contact causes oil to be blown onto the surface of the upper roller 25. The transfer paper 19 passes through the upper roller 25 and the lower roller 26 coated with this oil, so that the transferred image is fixed under pressure. Then, the transfer paper J9 on which the image has been fixed is discharged to the paper discharge tray 45 via the paper discharge roller 24.

As mentioned above, after the image is fixed, solenoid 3
2 is turned off. As a result, the lever 33 is activated by the return spring 3.
It is rotated clockwise by the urging force of 4, and its upper surface pushes up the protruding piece 29a of the holder 29, as shown in FIG.
) Rotate the holder 29 upward as shown.

As a result, the felt 28 is released from the upper roller 25 and separated.

Thereafter, the felt 28 is sequentially brought into contact with and separated from the upper roller 25 in the same manner.

As described above, since the felt 28 is separated from the upper roller 25 by the relief mechanism At when the fixing is not performed, it is possible to reliably prevent oil from seeping into the upper roller 25 or dirt from attaching to the upper roller 25. become.

In addition, on the lower side of the felt 28 in the direction of rotation of the upper roller 25, there is a felt 44 as a cleaning section.
is provided and is in actual contact with the upper roller 25. This felt 44 allows the felt 2 from the upper roller 25 to
This button allows the falling toner to be caught when the printer is separated from the printer in step 8, and prevents the copy from being smudged by falling toner.

[Effects of the Invention J] As explained above, the supplying body that contacts the fixing body and supplies oil with the above-mentioned conditions when not fixing is used.
Missing 4 for r111 from the sound body? , % 4, etc. When not fixed, dirt from the IC If'1 body does not land on the fixing body, or mail does not seep into the fixing body. 7] ・The object to be fixed is dirty], ta&), publication, 1, etc. It is effective to definitely prevent the problem of waiting for 1 time.

[Brief explanation of drawings]

Figure 4 is an explanatory diagram showing the slope and separation. 19...Fixed body (transfer paper), 25...Fixing body: roller), 28... Supply body (felt), A...Sounding mechanism. Applicant's Representative Patent Attorney Takehiko Suzue Figure 3, Figure 4, Figure 7, Contents of the amendment (The scope of the 11th patent claim is corrected as shown in the attached sheet. (2) " 45” to 1
25,” he corrected. (3) "When not fixing an image" written in lines 13 to 14 on page 6 of the specification is corrected to "when not copying." (4) Correct the third figure in the drawing as shown in the attached sheet. 2. Claims (1) A fixing body that presses against a fixing object and fixes it; a supply body that contacts this fixing body and supplies oil; and a supply body that is separated from the fixing body when not fixing. A fixing device characterized by comprising a relief mechanism. (2) The fixing device according to claim 1, wherein the fixing body is a roller, and a cleaning section is provided on the downstream side of the supply body in the direction of rotation of the roller. (3) The fixing device according to claim 1 or 2, wherein the supply body is felt.

Claims (1)

[Scope of Claims] (1) A fixing body that comes into pressure contact with the object to be fixed and fixes it;
A fixing device comprising: a supply body that contacts the fixing body and supplies oil; and a relief mechanism that separates the supply body from the fixing body when not fixing. 2. The fixing device according to claim 1, wherein the f2+ removable body is a roller, and a cleaning cap is provided on the downstream side of the supply body in the direction of rotation of the roller. (3) The fixing device according to claim 1 or 2, wherein the supply member is felt.