JPS608876A - Fixing device - Google Patents

Abstract

PURPOSE:To prevent contacting parts of a couple of pressure bodies which are brought into press-contact with each other from deforming by providing a press- contact releasing mechanism which allows the couple of pressure bodies to leave each other through the reciprocal motion of a rack and a pinion unless fixation is in process. CONSTITUTION:A fixing roller 28 and an upper frame 25 fitted with a collared roll 31, and a fixing roller 29 and a lower frame 26 fitted with a collared roll 32 are coupled together rotatably by a shaft 27, and the rack 35 is interposed between the roll 33 and pinion 34. When a motor is driven to move the rack 35 as shown by an arrow (a), the roll 31 is lowered along a taper part 36, and the upper roller 28 is brought into press-contact with the lower roll 29 by the pressure of a spring 30 to pass transfer paper between both. The motor is reversed after the fixation to move the rack 35 as shown by an arrow (b), and then the rollers 28 and 29 leave from each other. Thus, the fixing roller 27 and 28 are out of press-contact with each other all the time, so roller contacting parts does not deform by pressure, and plastics, etc., are used for the rollers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a constant M mount provided in, for example, an electrophotographic copying machine.

[Technical background of the invention and its problems]

As this type of fixing device, for example, the one shown in FIG. 1 is known. That is, in the figure, reference numeral 1112 denotes a pair of rollers, and these rollers 1 and 2 are pressed against each other by a spring 3 with a pressure of, for example, about 3 (1=/crn), and the unfixed copy 4 is passed between these rollers 1 and 2. This helps to fix the image.

By the way, in recent years, rollers I have been developed that have been treated with a satin finish to eliminate the gloss of copies, and rollers 2 that have been molded with plastic 5 have been developed to improve the finished quality of copies. has been done.

However, since the roller 2 of the above-mentioned one is molded from plastic, when the rollers 1 and 2 are pressed together for a long time,
Creep deformation occurs in the rough contact portions of the rollers 1 and 2, creating a step on the rollers, and this step causes an unpleasant clicking sound during rotation, which is very unpleasant to the ears.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a device for adjusting the constant That is.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention brings pressure bodies of 1 to 1 that are in pressure contact with each other into pressure contact between 1 and 1E during non-fixing.
'i! It is equipped with a remover Ij4.

[The fruits of invention 7i! Example 1 The present invention will be described below with reference to 11 examples shown in FIGS. 2 to 4. In the figure, reference numeral 11 denotes a copying machine main body, and a photosensitive drum 12 is provided in the copying machine main body 11.A charging device 13, a developing device 14, a developing device 14, ill: ζ photo charger 15
, a peeling charger 16 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 J9 is taken out one by one by a paper feed roller 2o. Further, 21 transfers the transfer paper J9 to the photosensitive drum 12.
22 is a transport section 81) 2 that transports the transfer paper 19 as a fixing object on which the mountain iJ has been transferred. A fixing device 23 and a paper ejection roller 24 are provided in the second conveyance section 22.

The fixing device 23 is constructed as shown in detail in FIG. 3 2 and m4(2). That is, 25 is an upper frame, and a lower frame 26 is rotatably supported on this upper frame 251C via a shaft 27. An upper roller 28 as a pressure member is attached to the upper frame 25, and several lower rollers 29 are installed on the lower frame 261. In addition, the upper frame 25 and the lower frame 26
The ends opposite to the pivot are biased toward each other by the spring 30ζ. Also, τj1 of the upper frame 25
A first flange roller 3 is attached to the lower part of one side, and a second flange roller 32 is mounted on the upper side of the lower frame 26, spaced apart from and facing the first flange roller 31. Attached retail. Further, on the lower frame 260) side m, a third flanged roller 3 is located at the lower part of the shaft 27.
3 is attached, and a pinyon 34 is attached to the lower part of this third flange roller 33. A rack 35 constituting the contact/separation mechanism A is inserted between the first and second flange rollers 31, 32 and the third flange roller 33 and pinion 34. One end of the rack 35 is engaged with the pinion 34, and a tapered cap 36 is formed at the other end 11111.

The shaft 34a of the pinion 34 is connected to a motor 38 via a form gear device 37, as shown in FIG. The motor 38 rotates in forward and reverse directions to reciprocate the rack 35 left and right. That is, the motor 38 is rotated in the forward direction when fixing the image 1 11, and reversely rotated when the spool 1 is not fixing the image.

In the above-described configuration, in the image formation 11!1, the top of the photosensitive drum 12 is charged by the band 71 and the device 13, and an electrostatic charge is applied to the charged photosensitive drum 12 by an e-exposure system (not shown). an image is formed. This η
The P electrolyte latent image is visualized by supplying a developer at a development stage 614. On the other hand, at this time, Kg paper cassette 1
The transfer paper 19 of the 8th day is taken out one by one from the paper feed roller 2oζ, and transferred to the paper sensitive drum 12 by the first conveyance section 2).
and the transfer charger 15. Here, the iI\ image on the photosensitive drum 12 is transferred onto the transfer paper 191 by the action of the transfer charger 15. The transfer paper J9 on which this image has been transferred is separated from the photoreceptor drum 12 by the action of the FliU charger 16, passes through the second conveyance path 22, and is sent to the ApiM device 23. At this time, the drive motor 38 of the fixing device R2:1 is operated and rotated forward, and the pinion 34 is rotated. As a result, the rack 35 is moved in the direction of arrow a, the flange rollers 31 of the frame 25 are lowered along the taper 36 of the rack 35, and the upper roller 28 is pressed against the lower roller 29 by the pressing force of the spring 30. be done. In this way, applying a pressure of 1N, the transfer paper 19 is pressed between the lower rollers 2B and 29, and the image is fixed under pressure. In this way, the image
4! 'IJ's IF, force-fixed transfer paper 794;
t Ijl 祇τ1-R24 Sono' and the paper is ejected to the paper ejection tray 11. - Power, ii:il j (J" set, the end of the door is the differential, f device hood drive 4s1 The sweater 38 rotates continuously, and when the rack 35 brim is marked with the big name 34i-fl-, it is ``6H4JI sai LO0 from this Ij, the Arene 25 is called;') 3i is the rack. 35's 1-bar 36 zi → upper case? 4 Shibane 30's 4111.i:
River in power, Shideue IJ 7 Z87-B 'i-D '7
From 29 upwards'\i4i: (L-ifzu4t.

After that, +!・(1 (K1 times, upper roller 28 is lower roller 294 times) (, -C together with I
Sru.

As mentioned above, when the non-image foot is 7, press the upper F roller 2.
Even if the rollers are molded with Schiffsnack "C" to release the pressure contact between the rollers 28 and 29, the contact portions of the rollers 28 and 29 will be creep deformed.

r: f i;, In the above N31 embodiment, the pressure contact release mechanism was configured by the dragon 35 and the pinion 34, but the mechanism is not limited to this, and as shown in No. 5 C1, a swing arm is attached to the lower frame 26. 51, and by swinging one end of this swing arm 51 by the rotation of the cam 52, the upper frame 25 is rotated via the cam follower 53, and the upper roller 28 approaches and separates from the lower roller 29. You may also do so.

〔Effect of the invention〕

As explained above, the present invention has a method for tracing a probe-equipped body between a pair of pressurizing bodies that are in pressure contact with each other and applying pressure fixing thereto, and fixing the pressurized body with pressure when the pair of pressurizing bodies are not fixed. G apart 1
(1) Since a pressure release mechanism is provided, the pressure deformation of the pressurizing body can be reduced as much as possible compared to the conventional method in which a pair of pressurizing bodies are continuously pressed against each other. Therefore, even if the pressurizing body is made of a material that easily undergoes creep deformation, such as plastic, it is not possible to achieve good fixation without causing unpleasant noises due to deformation.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing a conventional pressure foot M device, Fig. 2 and Fig. 4 are self-explanatory embodiments (a book), and Fig. 2 shows a partially broken electronic copying device. 3 is a top view showing the pressure fixing device, FIG. 4 is a plan view showing the drive system of the pressure release mechanism, and FIG. 5 is a side view showing another example. 28.29...Pressure body (roller), 19...Fixed body (transfer paper), A...Pressure release mechanism. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 3 Figure 4

Claims (2)

[Claims] (1) In an apparatus for pressure fixing by passing a fixing object between a pair of pressure bodies that are in pressure contact with each other, a pressure release mechanism is provided for separating the pair of pressure bodies when not fixing, and this pressure release mechanism is provided. The fixing device 4 is characterized in that it has a pinion and a rack that is reciprocated by the pinion, and that the pair of pressurizing bodies are separated by the reciprocating movement of the rack. (2) Pressure contact) 5: The fixing device according to claim 1, characterized in that it is equipped with a two-stage cam for removing machine tin-t'.