JPS62210490A - Fixing device - Google Patents

Abstract

PURPOSE:To surely fix a toner image on a recording member by causing a fixing part to stop its action while holding is released between two rollers. CONSTITUTION:When paper jamming occurs, first a pressure release lever 8 turns in the direction of an arrow A in figure. At that time the longitudinal radial parts of pressure release cams 9a and 9a are positioned toward the side of spring members 4 and 4, and supporting members 8 and 8 turn in the direction of an arrow B with one ends 8a and 8a as a center. The pressure between a heat roller 1 and a pressure roller 2 is released, whereby a jammed recording paper can be taken out. A jammed paper outlet switch 6 is in an OFF state, which does not means that the recording paper is carried out to the paper discharge side. The effect is displayed on a display part, etc., whereby a user can easily know said state, and never mistakenly sets a next copying action.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a fixing device in a copying machine having a pressure release function, for example.

(Prior Art) Conventionally, in the fixing section of a copying device, a recording sheet on which a toner image has been formed is conveyed while being sandwiched between a heat roller and a pressure roller, and the toner image is fixed onto the recording sheet using heat and pressure. things are being done.

By the way, such a fixing unit is generally provided with a mechanism for releasing the sandwiched state between the heat roller and the pressure roller so that the jammed recording paper can be easily removed when a paper jam occurs.

For example, if the pressure roller is pressed into contact with a fixed heat roller by a pressure mechanism having a spring, the copying machine uses a pressure release lever to release the pressure from the pressure mechanism to the pressure roller. The pressure can be released from the outside by protruding from the outside.

(Problem to be Solved by the Invention) However, even when the pressure release lever is not used to pressurize the pressure roller after the above-described pressure release operation is performed and the jammed recording paper is removed from the fixing unit, the conventional Since the copying apparatus performs a copying operation, recording paper on which a toner image is not fixed is conveyed out.

The present invention was devised in view of the above-mentioned circumstances, and an object of the present invention is to provide a fixing device that can reliably fix a toner image to a recording member.

[Structure of the Invention] (Means for Solving the Problems) That is, the fixing device of the present invention conveys a recording member on which a toner image is formed while sandwiching it between two rollers, and transfers this toner image onto the recording member. a fixing unit for fixing the fixing device, a pinch release means for releasing the pinch state between the two rollers of the fixing unit;
A carry-out detection means is disposed on the recording member carry-out side between the two rollers of the fixing unit and detects that the recording member has been carried out from the fixing unit; and a pinch release means detects the pinch state between the two rollers. The fixing device further includes a connecting means that operates in conjunction with the unloading detecting means to cause the recording member to not be unloaded from the fixing unit when the recording member is released.

(Function) In the fixing device of the present invention, when the nipping state between the two rollers of the fixing unit is released by the nipping release unit, the connecting unit interlocks with the unloading detection unit to detect when the recording member is unloaded from the fixing unit. As a result, the toner image can be reliably fixed on the recording member.

(Example) Hereinafter, details of an example of the present invention will be described based on the drawings.

FIGS. 1 and 2 are diagrams showing a fixing device according to an embodiment of the present invention.

As shown in these figures, this fixing device includes a heat roller 1 that is heated to a predetermined high temperature and driven to rotate, and a pressure roller 2 that is arranged along this heat roller 1 and is driven to rotate in synchronization with the heat roller 1. However, both ends of the shaft 2a of the pressure roller 2 are supported by a support member 3.3.

This support member 3 has one end 3a pivoted to the main body, and the other end 3a.
b is pressed against the pressure roller 2 by the spring member 4.4.
An elastic force is applied in the direction in which the heat roller 1 comes into contact with the heat roller 1.

On the other hand, a paper jam removal switch 6 is disposed between the recording paper discharge side of the heat roller 1 and the pressure roller 2 and the paper discharge roller 5.5, and the paper jam removal switch 6 is turned 0N10FF by the actuator 7.

This paper jam removal switch 6 is used in timing synchronization with an entrance switch (not shown) that detects when recording paper (not shown) is carried in from the paper feed side of this copying apparatus. In other words, normally, the entrance switch detects that the recording paper has been carried in, the paper jam removal switch 6 detects that the recording paper has been carried out, and the completion of a series of copying operations is detected. If the entrance switch detects that the recording paper has been carried in, and the paper jam removal switch 6 does not detect that the recording paper has been carried out even after a predetermined period of time has elapsed, there is a paper jam in this copying device. It is determined that this has occurred, and the copying apparatus displays the same, and the copying operation is stopped.

In addition, the actuator 7 has a center 7a attached to the main body so as to be swingable, one end 7b protruding into the recording paper conveyance path, and the other end 7C abutting the switch part of the paper jam volume reduction switch 6.
When no recording paper is present at one end 7b, an elastic member (not shown) applies a resiliency force in a direction in which the other end 7C comes into contact with the switch portion of the paper jam removal switch 6.

When recording paper is present in the recording paper discharge path, this paper jam removal switch 6 is turned off, and when no recording paper is present, it is turned on.

Further, on the opposite side of the spring member 4.4 between the other ends 3b, 3b of the support member 3.3, a shaft 9 is arranged, which rotates in conjunction with a pressure release lever 8 that projects outside of the copying device. The outer periphery of the shaft 9 has support members 3.3 near both ends.
Pressure release cams 9a, 9a having a long diameter portion that abuts on are fixedly attached.

Further, a protrusion 9b is formed on the shaft 9 at a position close to the actuator 7 and directed toward the actuator 7.
On the other hand, a protrusion 7d is formed from the one end 7b side of the actuator 7 toward the protrusion 9b to abut and interlock with the protrusion 9b.

In this fixing device, during normal copying operation,
The recording paper on which the toner image has been formed is conveyed while being held between the heat roller 1 and the pressure roller 2, the toner image is fixed on the recording paper, and then this recording paper comes into contact with one end 7b of the actuator 7. , the paper jam removal switch 6 is turned off, the recording paper passes through one end 7b of the actuator 7, and the paper jam removal switch 6 is turned on, confirming that there is no paper jam. This recording paper is conveyed to the paper ejection side while being held between paper ejection rollers 5.5.

If a paper jam occurs in this fixing device, the pressure release lever 8 is first rotated in the six directions of the arrows in the figure. At that time, the long diameter portion of the pressure release cams 9a, 9a is connected to the spring member 4.
．． The support member 8.8 has one end 8a, 8
It rotates in the direction of arrow B in the figure around a, the pressure between the heat roller 1 and the pressure roller 2 is released, and the jammed recording paper can be removed.

At that time, at the same time, the protrusion 9b formed on the shaft 9 comes into contact with the protrusion 7d of the actuator 7, and this protrusion 7d
is rotated in the direction of arrow C in the figure.

Therefore, the paper jam volume release switch 6 is turned off, that is, the recording paper is placed in this position.

Therefore, if the pressure between heat roller 1 and pressure roller 2 is released, the recording paper will not be conveyed to the paper ejection side, and the copying machine will continue to be in a paper jam state. Therefore, this information is displayed on, for example, a display unit provided in the copying machine, so that the user can easily know this state and prevent the user from accidentally performing the next copying operation.

At that time, even if the user accidentally performs the next copying operation, the copying operation is stopped, so the next copying operation will not be performed, and the recording paper on which the toner image is not fixed will be ejected. That will no longer be the case.

[Effects of the Invention] As explained above, according to the fixing device of the present invention, the fixing section does not operate when the nip between the two rollers is released, so that the toner image can be reliably fixed on the recording member. You will be able to do this.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of a fixing device according to an embodiment of the present invention, and FIG. 2 is a schematic perspective view thereof. 1...Heat roller 2...
・・・・・・Pressure roller 3.3・・・・・・
Support member 4.4... Spring member 5.5... Paper ejection roller 6... Paper jam amount loss switch 7.
・・・・・・・・・Actuator 9・・・・・・
...Shafts 9a, 9a...Pressure release cam 7d19b...Protrusion

Claims (1)

[Claims] (1) A fixing unit that conveys a recording member on which a toner image has been formed while sandwiching it between two rollers and fixing this toner image on the recording member, and releasing the sandwiching state between the two rollers of this fixing unit. a pinch release means; a carry-out detection means disposed on the recording member carry-out side between the two rollers of the fixing unit to detect that the recording member has been carried out from the fixing unit; 1. A fixing device comprising: a connecting means that operates in conjunction with the unloading detection means to set the recording member in a state in which the recording member is not unloaded from the fixing unit when the nipping state between them is released.