JPH08110729A - Thermal fixing device - Google Patents

Abstract

PURPOSE: To prevent the fall of foreign matter on a recording paper, and secure a uniform contact pressure between a cleaning member and a heating roller by providing a collecting means of the removed foreign matter through the cleaning member, which removes the foreign matter such as a toner or the like stuck to the peripheral surface of the heating roller, in the cleaning member itself. CONSTITUTION: In the structure of a cleaning member 4, the tip part of a stuck matter containing part 42 is made to be upward from the horizontal direction so that the inner side of the stuck matter containing portion 42 is made to incline downward. A remaining toner is not allowed to stick to and remain in the tip portion, but the stuck matter can surely be fed to the stuck matter containing part 42 arranged behind. The width of a heating roller touching part 41 is set to be wider than the width of a temperature detection member so as to collect the lump and the like of the separated foreign matter from the temperature detection member mainly. Since the width of the touching part 41 is not allowed to reach the full length in the width direction of a heat-sensitive roller but is set to exceed the width of the temperature detection member by predetermined length, contact pressure between the touching portion 41 and a roller peripheral surface can easily be maintained uniform.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a copying machine, a printer,
The present invention relates to an improvement in a fixing device used in an image forming portion of an electrophotographic image forming apparatus such as a facsimile, and more particularly, to an improvement in a cleaning member for collecting foreign matter such as toner adhering to a temperature detection member that contacts a heating roller.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus such as a copying machine, a printer or a facsimile, an electrostatic latent image obtained by supplying toner from a developing device to an electrostatic latent image on a photoconductor. After being transferred onto a recording paper, it is fixed by a fixing device. The fixing device has a heating roller having a heater inside, and a pressure roller that comes into pressure contact with the outer peripheral surface of the heating roller, and allows the recording paper having unfixed toner to pass through the nip portion of both rollers. The toner is heat-fixed on the recording paper. The temperature of the heating roller is detected by a temperature detecting means that is in sliding contact with the surface of the heating roller, and the control unit adjusts the current supplied to the heater based on the detection result so that the temperature of the heating roller is maintained at a predetermined value. I have to.

A conventional thermal fixing device is disclosed in, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Laid-Open No. 9-158057, there is one in which the cleaning member is arranged on the upstream side of the temperature detecting means in the rotating direction of the heating roller. Also, the actual exploitation 63
Japanese Patent No. 168463 discloses a technique in which the cleaning member is composed of a heat insulating cleaning member. Japanese Utility Model Laid-Open No. 61-86760 discloses a technique in which the cleaning member is a gutter having a blade surface.

[0004]

However, Japanese Unexamined Patent Publication No.
Since the fixing device disclosed in Japanese Patent No. 158057 has no means for accommodating the adhered matter such as toner scraped off by the cleaning member, the adhered matter may fall on the conveyed recording paper. In the invention disclosed in Japanese Utility Model Laid-Open No. 63-168463, since the rigidity of the cleaning member is weak,
It is difficult to reliably collect the deposits, and it is not possible to use
In the invention disclosed in No. 60, the cleaning member has rigidity, but since the cleaning member is in contact with the heating roller over the entire axial length, it is difficult to secure a uniform contact pressure,
As a result, there is a drawback that the cleaning ability varies.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and provides a means for collecting foreign matter removed by a cleaning member for removing foreign matter such as toner adhering to the outer peripheral surface of a heating roller constituting a fixing device. An object of the present invention is to provide a fixing device that can prevent foreign matter from dropping on a recording sheet by providing the cleaning member itself. It is also intended to ensure a uniform contact pressure between the cleaning member and the heating roller.

[0006]

In order to solve this problem, the present invention relates to a temperature detecting means for contacting a heating roller to detect the temperature, and a temperature detecting means downstream from the temperature detecting means in the rotating direction of the heating roller. It is characterized in that a cleaning member is provided on the side to contact the heating roller to clean the surface. Further, the present invention is characterized in that the cleaning range of the cleaning member is wider than the width of the temperature detecting member. Further, the present invention is characterized in that the cleaning member has a deposit accommodating portion. Further, according to the present invention, the heating roller contact portion of the cleaning member is
The feature is that it is an acute angle and faces upward with respect to the horizontal direction. The present invention is characterized in that the cleaning member is supported at three points.

[0007]

According to the present invention, the temperature detecting member and the cleaning member are brought into contact with the heating roller, and the cleaning member is arranged downstream of the temperature detecting member to prevent the deposits from falling. Further, the cleaning member is brought into uniform contact with the three-point support to ensure reliable cleaning.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of one embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic view of an example of a heat fixing device according to an embodiment of the present invention. An electrophotographic image forming unit (not shown) is provided on the right side of the fixing device, and the recording paper P, to which the toner image (not shown) on the photoconductor is transferred, is heated by the fixing device to press the toner. To settle. This fixing device has a heating roller 1a having a heater 2 therein and a pressure roller 1b which is in pressure contact with the heating roller 1a, and a thermistor or other temperature detecting member 3 is provided at an appropriate position on the outer peripheral surface of the heating roller 1a. The temperature of the heating roller 1a is controlled by arranging them in a state of sliding contact. Further, a cleaning member 4 is arranged on the downstream side of the temperature detecting member 3, and the temperature detecting member 3 and the cleaning member 4 are attached to the frame 5. Further, the cleaning member 4 is pulled downward by the spring 6 so that the tip end portion thereof is in contact with (sliding contact with) the heating roller 1a.

After the fixing, the toner adheres and remains on the surface of the heating roller 1a which comes into contact with the unfixed toner on the recording paper. The toner remaining on the surface of the heating roller 1a adheres to the temperature detecting member 3 or is directly conveyed to the downstream side. Here, the residual toner in the cleaning range of the cleaning member 4 that has not adhered to the temperature detection member 3 is cleaned by the cleaning member 4. Further, the residual toner adhered to the temperature detecting member 3 is gradually peeled off due to cooling due to the stop of the image forming apparatus,
Although it is transported to the downstream side, the cleaning member 4 is disposed downstream of the temperature detecting member 3, so that the cleaning member 4 is cleaned and collected without falling down and adhering onto the recording paper or the like.

FIG. 2 is an external perspective view of an example of the cleaning member according to the embodiment of the present invention. The cleaning member 4 is integrally configured by the heating roller contact portion 41 at the front end edge, the adhering matter accommodating portion 42, the side walls 43 closing both sides of the accommodating portion 42, and the cleaning member supporting portion 44 protruding at the rear end. The shape of the tip of the heating roller contact portion 41 is an acute angle, and 0 ° <θ1 <9.
It is 0 °. Further, as shown in FIG. 1, the heating roller 1
The angle formed with the outer peripheral surface of a is 0 ° <θ2 <90.
Due to the angle .degree., The distal end of the accommodating portion 42 faces upward from the horizontal direction, and the rear side of the accommodating portion 42 is inclined downward. As a result, the residual toner does not adhere to and remains on the tip end, and the adhering matter can be reliably sent to the adhering matter accommodating portion 42 located at the rear. Further, the width of the heating roller contact portion 41 is wider than the width of the temperature detection member 3, and mainly collects a lump of foreign matter or the like separated from the temperature detection member 3. In addition, the width of the contact portion 41 does not extend over the entire length in the axial direction of the heat-sensitive roller, but only exceeds the width of the temperature detecting member 3 by a predetermined length, so that the contact portion 41 and the roller are not in contact with each other. It is easy to maintain a uniform contact pressure with the peripheral surface. Further, this contact pressure is made more reliable by the three-point support structure described later.

3 (a), (b) and (c) are front longitudinal sectional views of an example of a cleaning member supporting means according to an embodiment of the present invention.
It is a right view and a perspective view of (a). Cleaning member support 4
Reference numeral 4 denotes a rod portion 44a which is inserted into a vertically long hole 5a provided in a rear wall 5A of the frame 5 and which has a rear end engaging portion 4a.
4b is projected outward from the hole 5a to prevent it from falling off. As shown in FIGS. 3 (a), (b) and (c), the rod portion 44a has a distance t1 between the cleaning member main body and the rear wall in the A direction of 0 <t1, and the distance between the rod portion 44a and the hole 5a is B. Direction space t
2 is 0 <t2, and the space t3 in the C direction between the rod portion 44a and the hole 5a is 0 <t3. The locking portion 44b is in contact with the back surface of the rear wall at a point c. Therefore, the cleaning member can be rotated in all directions around the point c. Further, as shown in FIG. 1, since the spring 6 is arranged between the cleaning member and the rear wall 5A to pull the cleaning member downward about the point c, the tip of the cleaning member is A certain contact part 4
1 can surely come into sliding contact with the outer peripheral surface of the heating roller 1a. Moreover, since the cleaning member 4 is supported at three points a, b, and c, it can be uniformly pressed against the heating roller 1a.

[0012]

According to the present invention, the temperature detecting means for contacting the heating roller to detect the temperature, and the heating roller located downstream of the temperature detecting means in the rotating direction of the heating roller. Since the cleaning member for cleaning the surface by contacting with is provided, it is possible to obtain a high-performance heat fixing device in which adhered substances do not drop downward. According to the second aspect of the invention, since the cleaning range of the cleaning member is wider than the width of the temperature detecting member, the adhered matter that has wrapped around the temperature detecting member 3 can also be collected. According to the third aspect of the invention, since the cleaning member has the adhering matter accommodating portion, it is possible to obtain a high-performance heat fixing device in which the adhering matter does not drop downward. According to the invention described in claim 4, since the heating roller contact portion of the cleaning member has an acute angle and faces upward with respect to the horizontal direction, the adhered matter does not adhere to the tip. Further, the adhering matter can be reliably sent to the adhering matter accommodating portion. According to the invention described in claim 5, since the cleaning member is supported at three points, it is possible to uniformly apply pressure to the heating roller.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a heat fixing device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of a main part of a heat fixing device according to an embodiment of the present invention.

3A is a front vertical cross-sectional view of a main part of a heat fixing device according to an embodiment of the present invention, FIG. 3B is a side view, and FIG. 3C is a perspective view.

[Explanation of symbols]

 1a, 1b Heating roller 2 Heater 3 Temperature detection member 4 Cleaning member

Claims (5)

[Claims] 1. A temperature for detecting a temperature by contacting a heating roller constituting the heat fixing device in a heat fixing device used for fixing unfixed toner on a recording sheet in an electrophotographic image forming apparatus. A thermal fixing device comprising: a detection unit and a cleaning member downstream of the temperature detection unit with respect to the rotation direction of the heating roller, the cleaning member contacting the heating roller and cleaning the surface. 2. The thermal fixing device according to claim 1, wherein a cleaning range of the cleaning member is wider than a width of the temperature detecting member. 3. The thermal fixing device according to claim 1, wherein the cleaning member has an adhering substance accommodating portion. 4. The thermal fixing device according to claim 1, wherein a tip of the heating roller contact portion of the cleaning member has an acute angle, and the heating roller contact portion is positioned horizontally with respect to the deposit accommodating portion. The thermal fixing device is characterized in that it faces upward. 5. The thermal fixing device according to claim 1, wherein the cleaning member supports three points.