JPS58203470A - Fixation device - Google Patents

Abstract

PURPOSE:To prevent a peeling liquid such as a silicone oil, an offset preventing liquid, or the like from being stuck to a carrying roll and transferred to a supporting material, by providing a rubbing member, which removes the peeling liquid stuck to the carrying roll, so that this member is brought into contact with a carrying roll on the downstream side of a fixation roll. CONSTITUTION:A silicone oil removing felt 30 which rubs a carrying roll 15, which is brought into contact with the image side of a form 5, throughout in the breadthwise direction has a function to remove the silicone oil stuck onto the carrying roll 15, and a flat spring 31 has a function to press the silicone oil removing felt 30 to the carrying roll 15. Through a silicone oil 17 stuck onto the form 5, where an image is fixed, is stuck to the carrying roll 15 temporarily, this silicone oil 17 is removed by the silicone oil removing felt 30 and is not transferred again to the form 5, and therefore, silicone oil wetting is restrained to a minimum. Though silicone oil wettings 21 and 22 is caused in the center of the image area in a conventional case, silicone oil wetting is caused in the leading edge part of the form 5 only slightly and is almost eliminated in this constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixing device for an image recording device such as a laser beam printer. Furthermore, the present invention relates to a fixing device having a mechanism for applying a release liquid for separating sheets of paper to one of the rotating bodies, such as a roller, of a pair of rotating bodies included in the fixing device.

Conventionally, this type of apparatus has been constructed as shown in FIG. l
is a heating roller, and the surface of the metal cylinder /1/ is
-1 is Teflon coated. Heat the heating roller l with a heater. Reference numeral 3 denotes a pressure roller, and the outside of a metal cylinder 3-/ is formed with a silicone rubber layer 3-2, and the outside thereof is further covered with a Teflon tube 3-3. The heating roller 1 and the pressure roller 3 have a width that is the maximum copy paper width plus an allowance. The heating roller 3 and the pressure roller 3 constitute a pair of fixing rollers, 3 is rotatably supported by both rollers, and the pressure roller 3 has means (not shown) for pressing the heating roller 3.

The heating roller 1 is rotated in the direction of the arrow by a drive device (not shown), and the pressure roller 3 is rotated as a result of the heating roller 1.

When the paper l is fed into the conveyor l/, the unfixed paper is transferred to both rollers/.

3, the image is fixed by heating and pressurizing, and then sent onto the conveyor 12. S is a fixed paper. A rotatably supported roller 6 which is in contact with the heating roller 1 is an application roller which contacts the heating roller 1 and applies silicone oil 7 which has been removed by a stripping liquid onto the heating roller 1.

g is silicone oil 7 in oil pan 9 with coated felt.
One end is submerged therein, and the other end is in contact with the roller 6, and has the function of drawing up the silicone oil 7 and supplying it to the application roller 6. 1
0 is a plate spring that ensures the contact between the coating felt g and the coating roller 6. Here, when the application roller 6 rotates in the direction of the arrow following the heating roller l, the silicone oil is evenly applied to the heating roller, and the toner T on the unfixed sheet of paper adheres to the heating roller l (offset). )
It works to prevent /3 and /4' are separating claws whose tips touch the heating roller 1 and the pressure roller 3, respectively, and are used to prevent paper from wrapping (jamming) around the heating roller 1 and the pressure roller 3, respectively. . /! ; and /6 are a pair of paper ejection rollers or conveyance rollers that send out the paper to a stacker, sorter, or the like.

In the above configuration, not all of the silicone oil applied to the heating roller is transferred to one sheet of paper.
When used for a certain period of time, silicone oil 17 will adhere to the separation claw/s. Particularly during intermittent operation, a lot of silicone oil/'
7 is attached to the leading edge/g of the paper S. Furthermore, the conveyor roller/
! ;, /&, the silicone oil /7 attached to the paper 5 is transferred to the conveyance roller 15, and the conveyance roller 15
When it rotates, silicone oil/7 is transferred to the paper S again.

The paper 5 finally output in this manner becomes wet with silicone oil as shown in FIG.

20.2/, 22 indicates silicone oil wetting. 1 is a length corresponding to the circumferential length of the conveyance roller 15.

It goes without saying that silicone oil wetting deteriorates the quality of the output paper, but silicone oil wetting λl, ko, 21, etc. in the center of the image area is a particularly serious drawback. This phenomenon occurs very often when the conveyor // is not present.

(3) In addition, conventional fixing devices that separate the separating claw from the surface of the fixing roller and apply or supply a large amount of a removing liquid such as silicone oil to enhance the peeling property or two or more types of color copying devices are used. In printers that form images by mixing color toners, laser beam printers, etc., there are fixing devices that supply or apply a larger amount of release liquid than in monochrome copies in order to maintain the release properties.

In such devices, the surface of the transport roller ζ is a supporting material (such as plain paper) that supports the image, to which the peeling liquid easily adheres.
The front and back sides of the machine become easily stained with liquid.

Therefore, it is difficult to write on such support materials, which is a practical obstacle.

The present invention has been made in view of the above-mentioned problems, and has an object of preventing a stripping liquid such as silicone oil or anti-offset liquid from adhering to a conveying roller and transferring to a support material.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a side sectional view of the present invention.

The silicone oil removing felt 30 that rubs against the entire width (g) of the conveyance roller IS in contact with the image side of the paper j has the function of removing silicone oil adhering to the conveyance roller IS. The leaf spring 31 has the function of pressing the silicone oil removal felt 30 against the conveyance roller /k. The structure of other parts is exactly the same as the conventional example shown in FIG.

In the above configuration, the silicone oil 17 that adheres to the fixed paper s adheres to the conveyance roller 15 once, but is removed by the silicone oil removal felt 3θ and is not retransferred to the paper S, so the silicone oil wetting remains at a minimum. As shown in Figure 1, it is almost invisible. In the conventional example, there was some silicone oil wetting in the center of the image area, but with the above configuration, most of it can be removed, although it may be slightly seen at the leading edge of the paper 5.

In the above embodiment, silicone oil removal felt is provided to rub against the conveyance roller that contacts the image side of the paper downstream from the fixing roller, which prevents silicone oil from getting wet in the center of the paper, which has great practical value. It is something.

The present invention can be applied to a fixing device that applies or supplies a release liquid such as silicone oil to a heat fixing roller, a pressure roller, a pressure fixing roller, or a coating roller, and is particularly applicable to fixing devices having a contact separation claw and color copying devices. Effective for machines, etc.

In the present invention, the support material is stained by the stripping liquid that adheres to the conveyance roller, and the surface of the conveyance roller is stained by developer such as toner, which occurs during jams or when repairing equipment, and is transferred to the support material by the adhered peeling liquid. This also solves problems such as stains and dirt on the back.

[Brief explanation of drawings]

FIG. 1 is a side view of a conventional fixing device, FIG. 2 is a plan view showing silicone oil wetting in a conventional example, FIG. 3 is a side view of an embodiment of this invention, and FIG. The results of the example are shown in 1. FIG. 1/... Heating roller Co-heater 3... Pressure roller
l-/・Fist cylinder −−K・Fist surface 3-1・・Cylinder 3-, t・・Silicone rubber layer 3-3・・Teflon tube T・・Toner da, 5・・Paper 6・・Applying roller 7・-Silicone oil ・・Applied felt ・・・Oil pan 10・・Plate spring //, /2・・
Conveyor /, 3. / Goo・Separation claw is, it −1 Conveyance roller 17・Fist silicone oil lza・・Tip
20. Col, 22...Silicone oil wet 30...
Silicone oil removal felt. Patent Applicant Canon Co., Ltd. Agent Arai -buqykaioasg-2o3a7o (4)

Claims (1)

[Claims] l A fixing device having a pair of fixing rollers, a mechanism for applying a release liquid to at least one of the pair of fixing rollers, and a conveying roller provided downstream of the fixing roller in the support material conveying direction. A fixing device characterized in that a rubbing member for removing the stripping liquid adhering to the conveying roller is provided so as to be in contact with the conveying roller downstream of the fixing roller.