JPH042192B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fixing device for a copying machine using an electrophotographic process, and particularly to a paper peeling device for a heated roll type fixing device.

[Conventional technology]

Generally, a copying machine using an electrophotographic process is provided with a fixing device that fixes an unfixed toner image on a sheet of paper, and a so-called heated roll type fixing device is widely used as an example of this fixing device.

Conventionally, this type of fixing device is equipped with a heated heating roll a and a heating roll b that is in pressure contact with the heating roll a and rotates together with the heating roll a, as shown in FIG. 10, for example. By inserting paper d on which unfixed toner image c is held between the pair of rolls a and b, heat from heating roll a and pressure from pressure roll b are applied to the toner and paper d. The unfixed toner image c is fixed on the paper d.

In this type, the heating roll a is fitted with a shaft (not shown), for example, and has a cylindrical core e made of metal or the like having mechanical strength that can withstand pressure.
and a heater f disposed inside this cylindrical core e.
and a material that satisfies heat resistance, toner release properties, etc.
For example, HTV silicone rubber (High
Temperature Vulcanization Silicone
and a heat-resistant release layer g formed by coating the surface of the cylindrical core e with polytetrafluoroethylene (PTFE) or polytetrafluoroethylene (PTFE).

On the other hand, the pressure roll b is, for example, a shaft h
It is configured in a cylindrical shape to be fitted into the heating roll a, and is made of a material that forms a predetermined fixing nip when it comes into contact with the heating roll a and satisfies heat resistance, etc., specifically, HTV silicone rubber, fluorocarbon rubber, etc. , EPDA rubber (Ethylene Propylene Diene Acryl Rubber)
It is molded from heat-resistant elastic material such as

By the way, in such a fixing device, since the toner surface of the paper d comes into direct contact with the surface of the heating roll a, there is a situation where the paper d gets wrapped around the surface of the heating roll a due to the sticky nature of the softened toner. will occur. In order to prevent such a situation, a device for peeling off the paper d wrapped around the surface of the heating roll a is usually required.

Conventionally, this type of paper peeling device has a plurality of peeling claws i made of metal or heat-resistant plastic along the length of the heating roll a, as shown in FIG. The base of a peeling claw i with a sharp tip is pivoted to a support part (not shown), and the tip of the peeling claw i is pressed against the surface of the heating roll a with a load of several grams to several tens of grams using a biasing spelling j or the like. This is what I did.

According to this type, the tip of the peeling pawl i does not lift up from the heating roll a even when the heating roll a rotates or the paper d hits the tip of the peeling pawl i, and the peeling pawl i is stably arranged. has been done. Therefore, the paper d that is being conveyed wrapped around the surface of the heating roll a is effectively peeled off by the tip of the peeling claw i, guided by a guide member k disposed near the peeling claw i, and guided by the discharge roll l.
They are led to the side.

[Problem that the invention seeks to solve]

However, in such a conventional paper peeling device, even after the leading edge of the paper d is peeled off by the peeling claw i, the sharp tip of the peeling claw i is partially pressed against the toner surface of the paper d. Because of this structure, a strong force acts on a portion of the toner in contact with the tip of the peeling claw i, resulting in the toner being scraped off.

In particular, when the toner image c is formed on the entire surface of the paper d, the portion scraped off by the peeling claw i appears in a streaky manner, which causes a significant deterioration of the copy image quality. was.

[Means and actions for solving problems]

The present invention has been made based on the above-mentioned viewpoints, and its object is to fix the toner surface on the paper without impairing the peeling performance of the paper by using a fixing device equipped with a heating roll. It is an object of the present invention to provide a paper peeling device for a fixing device that prevents paper from being scraped off.

That is, in the present invention, a peeling claw is provided on the paper discharge side of the heating roll, and the sharp tip of the peeling claw is brought into contact with the surface of the heating roll, so that the paper is conveyed as the heating roll rotates. In a paper peeling device of a copying machine that peels paper from its leading edge and peels the paper from a heating roll while guiding the peeled paper with a guide member disposed near the peeling claw, , a paper peeling part with a wide contact width with the paper is formed, and between this guide member and the peeling nail, the tip peeling part of the peeling nail peels off the leading edge of the paper. A positional relationship reversal mechanism is provided to reverse the positional relationship between the paper peeling section of the guide member and the guide member to peel the paper. Instead of the peeling claw, the paper is peeled off by a guide member having a paper peeling part with a wide contact width with the paper, and since the paper peeling part of the guide member is evenly pressed against the entire surface of the paper, the toner is removed. This prevents strong force from acting on the surface, thereby preventing the toner from being scraped off.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. A peeling claw 4, which is disposed in the vicinity, peels off the leading edge of the paper 3 from the heating roll 1, a guide plate 5 which further peels off the paper from which the leading edge has been peeled off, and a solenoid (not shown) which moves the guide member 5. 2), and an actuator arm 6 which is a detection means.

First, the peeling claws 4 are made of metal, and four peeling claws are arranged along the length of the heating roll 1, with their bases pivoted to support parts (not shown) near the heating roll 1. and is formed by pressing the exfoliated portion at the tip thereof against the surface of the heating roll 1 by means of a spring 7.

On the other hand, as shown in FIG. 2, the guide plate 5 is composed of a plate-shaped body having a paper peeling part 8 with a rounded tip, and from this paper peeling part 8 in the width direction,
Four notch recesses 9 into which the peeling claws 4 are inserted
is formed, and a pair of pins 10, 10 are respectively attached to both ends of the third pin.
As shown in the figure, the pins 10, 10 are inserted into the guide holes 1 of the support plate 11 provided on both sides of the fixing device.
2 and 13, and is attached to a position near the heating roll 1, and connected to each of the pins 10, by the action of the solenoid 14, which moves from the position shown by the broken line in FIG. 1 to the position shown by the solid line. It is configured to be movable to different positions.

Further, the actuator arm 6 is constituted by a rod-shaped body having a rounded tip, and its base end is provided on the paper ejection side of the fixing device, and is used to control the operation of the solenoid 14. The switch 15 is connected to the switch 15 when the actuator arm 6 is pressed by the paper discharged from the fixing device and moves from the position shown by the broken line to the position shown by the solid line. It is designed to be turned on.

In FIG. 1, reference numeral 16 denotes a conveyor belt that conveys the paper 3 on which the unfixed toner image is formed to the fixing device.
Reference numerals 17 and 18 indicate fixed guides for guiding the paper 3, and 19 indicates fixed guides for guiding the fixed paper 3 onto the paper output tray 20.
A discharge roll is shown.

Next, to explain the operation of the paper peeling device of the present invention, as shown in FIG. It is first peeled off by the tip peeling part of the claw 4.

The leading edge of the peeled paper 4 presses the actuator arm 6 as the heating roll 1 rotates, moves it to the position shown by the solid line in FIG. 1, and moves the guide plate 5. Turn on switch 15 of solenoid 14.

Due to the action of this solenoid 14, the guide plate 5 moves downward, as shown in FIG.
The paper 3 is then separated from the heating roll 1 by the action of the paper peeling section 8 of the guide plate 5.

Therefore, the paper peeling portion 8 of the guide plate 5, which has a wide contact width with the paper and has a rounded shape, acts evenly on the toner surface of the paper 3, so that a strong force is applied to the toner surface. This prevents the toner from being scraped off.

Note that if the gap between the paper peeling section 8 and the heating roll 1 when the guide plate 5 acts is too wide,
As shown in FIG. 6, peeling of the paper 3 may be insufficient and the leading edge of the paper 3 may be bent and pass through the gap, so the paper peeling section 8 of the guide plate 5 during operation The gap between and heating roll 1 is
The thickness is preferably about 0.1 to 2 mm.

Then, the paper 3 peeled off by the guide plate 5
are guided by the guide plate 5 and the fixed guide 18 and are discharged from the discharge roll 19 to the paper discharge tray 20.

After the paper 3 has passed, the actuator arm 6 returns to its original position as indicated by the broken line in FIG. Return to the original position indicated by .

In this embodiment, the guide plate 5
The structure is such that the positional relationship between the tip peeling part of the peeling claw 4 and the paper peeling part 8 of the guide plate 5 is reversed by moving the peeling claw 4, as shown in FIG. The above positional relationship may be reversed.

That is, the guide plate 5 is fixedly provided in the vicinity of the heating roll 1, while the peeling claw 4 is provided with its support portion (not shown) movable, and the peeling claw 4 is provided so as to be movable so as to separate the paper 3 as shown in FIG. The tip is peeled off by the tip peeling part of the peeling claw 4, and then the switch 15 is turned ON by the action of the actuator arm 6, so that the support part (not shown) of the peeling claw 4 is connected to the solenoid ( (not shown) to reverse the positional relationship between the tip peeling part of the peeling claw 4 and the paper peeling part 8 of the guide plate 5, and the fixed guide plate 5 peels the paper 3. It's okay.

Further, in each of the above embodiments, a positional relationship reversing mechanism for reversing the positional relationship between the tip peeling part of the peeling claw 4 and the paper peeling part 8 of the guide plate 5 is moved with the actuator arm 6 serving as the detection means. However, in place of the actuator arm 6, a photo sensor for detecting the leading edge of the paper 3 inserted into the fixing device is arranged on the paper inlet side of the heating roll 1. , After a certain period of time, this detection signal causes the solenoid 1, which is the moving means, to
It goes without saying that the solenoid 14 may be replaced with a cam mechanism as a moving means.

Furthermore, in the above embodiment, the guide plate 5 is made of a plate-shaped body and has a paper peeling part 8 having a wide contact width with the paper, but instead of the plate-shaped body, a wire or the like is used in the same manner. A guide member formed by molding into the shape of may be adopted.

〔Effect of the invention〕

As described above, the present invention provides a paper peeling device for a copying machine comprising a peeling claw having a sharp tip peeling portion and a guide member disposed near the peeling claw.
A paper peeling part with a wide contact width with the paper is formed at the tip of the guide member, and between the guide member and the peeling claw, after the tip peeling part of the peeling claw peels off the leading edge of the paper, , is provided with a positional relationship reversal mechanism that reverses the positional relationship between this tip peeling part and the paper peeling part of the guide member and peels the paper with the guide member, so when peeling the paper, it is strong against the toner side of the paper. No force acts on it.

Therefore, unlike in the past, the toner surface is not partially scraped off by the peeling portion at the tip of the peeling claw, so deterioration of copy image quality can be prevented, and the practical effects of the present invention are great. be.

[Brief explanation of drawings]

1 to 6 show embodiments of the present invention. FIG. 1 is an explanatory diagram of the structure of the paper peeling device of the present invention, FIG. 2 is a plan view of the guide plate 5, and FIG. A side view showing the installed state of the guide plate 5, and FIGS. 4 to 6 are explanatory diagrams of the operation of this paper peeling device, and FIGS. 7 to 9 show other embodiments of the present invention. , FIG. 7 is an explanatory diagram of the configuration of the paper peeling device, FIGS. 8 and 9 are diagrams of its operation, and FIG. 10 is a diagram of the configuration of the conventional paper peeling device of a copying machine. [Description of symbols] 1...Heating roll, 2...Pressure roll, 3...Paper, 4...Peeling claw, 5...Guide plate, 6...Actuator arm, 7...Spring, 8... ...Paper peeling part, 9...Notch recess,
10... Pin, 11... Support plate, 12, 13...
Guide hole, 14... solenoid, 15... switch, 16... transport belt, 17, 18... fixed guide, 19... discharge roll, 20... paper discharge tray.

Claims (1)

[Claims] 1. A peeling claw is provided on the paper discharge side of the heating roll,
The sharp tip of this peeling claw is brought into contact with the surface of the heating roll, and the paper that is being conveyed as the heating roll rotates is peeled from the tip, and the peeled paper is placed near the peeling claw. In a paper peeling device for a copying machine that peels the paper from a heating roll while being guided by a guide member provided, a paper peeling part with a wide contact width with the paper is formed at the tip of the guide member, and the guide Between the member and the peeling claw, after the tip peeling part of the peeling nail peels off the leading edge of the paper, the positional relationship between the tip peeling part and the paper peeling part of the guide member is reversed, and the guide member removes the paper. 1. A paper peeling device for a copying machine, comprising a positional relationship reversal mechanism for peeling paper. 2. The peeling claw is fixedly provided, and the guide member is movably provided, and the positional relationship reversal mechanism moves the guide member to adjust the positional relationship between the tip peeling portion of the peeling nail and the paper peeling portion of the guide member. A paper peeling device for a copying machine according to claim 1, which reverses the paper. 3. The peeling claw is movably provided, and the guide member is fixedly provided, and the positional relationship reversal mechanism moves the peeling claw to adjust the positional relationship between the tip peeling part of the peeling claw and the paper peeling part of the guide member. A paper peeling device for a copying machine according to claim 1, which reverses the paper. 4. A patent in which the positional relationship reversal mechanism is comprised of a detection means provided on the paper input side or discharge side of the heating roll, and a movement means for moving the peeling claw or guide member based on a detection signal from the detection means. A paper peeling device for a copying machine according to claim 1.