JP3638877B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing device and an image forming apparatus, and more particularly to attachment of a heater provided inside a heat roller.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying machine or a printer, a sheet is inserted into a nip portion of a fixing roller composed of a heat roller and a pressure roller, and an unfixed toner image is fixed on the sheet by heat and pressure An apparatus is provided, and a heater for heating the roller is attached inside the heat roller. Particularly, in the image forming apparatus of the medium and high speed machine, two heaters are built in the heat roller, but workability when inserting the two heaters inside the heat roller and when attaching the heater to the fixing device. In order to improve the workability, it has been proposed to integrally form the terminals of the two heaters.
[0003]
[Problems to be solved by the invention]
However, when the two heater terminals are integrally formed as described above, the workability when the heater is inserted into the heat roller and the workability when the heater is attached to the fixing device are improved. Even when only the heater fails, there is a problem that the cost required for repair when the heater fails increases because both of the two heaters must be replaced.
[0004]
The present invention has been made to solve the above-described problems, and the workability when inserting a plurality of heaters inside the heat roller and the workability when attaching the plurality of heaters to the fixing device are improved. It is another object of the present invention to provide a fixing device and an image forming apparatus in which the cost required for repairing a heater failure is reduced.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 includes a heat roller having a plurality of heaters built therein, and a pressure roller that presses the sheet on which the unfixed toner image is transferred to the heat roller. In the fixing device for fixing the unfixed toner image on the paper by inserting the paper into the nip portion of both rollers,
Each terminal part provided in each of the plurality of heaters is integrally connected and electrically connected to each other, and includes a connecting member that can be detached from each terminal part,
The connecting member has a first protrusion that fits into a hole provided in a housing of the fixing device, and the heaters are connected to the fixing device by fitting the first protrusion and the hole. The power supply unit is electrically connected .
[0006]
The invention according to claim 2 is the fixing device according to claim 1, wherein the connecting member further includes a second projecting portion extending in a direction orthogonal to the projecting direction of the projecting portion, The second projecting portion comes into contact with the housing when the first projecting portion is fitted in the hole of the housing.
[0007]
According to a third aspect of the present invention, there is provided a heat roller including a plurality of heaters, and a pressure roller that presses a sheet having an unfixed toner image transferred to the surface against the heat roller. In a fixing device for fixing a non-fixed toner image on a sheet by inserting the sheet into the nip portion,
It is possible to attach to and remove from each terminal portion provided in each of the plurality of heaters, and includes a connecting member that connects and electrically connects these terminal portions together,
The connecting member includes a first protrusion that fits into a hole provided in the housing of the fixing device, and a hole provided in a side wall of the housing that extends in a direction orthogonal to the protrusion direction of the protrusion. When the first protrusion is in a fitted state, the second protrusion comes into contact with the side wall, and when the first protrusion is fitted in the hole, the bottom of the housing is abutted. A third projecting portion in contact therewith,
Each heater is configured to be electrically connected to the power supply unit of the fixing device by fitting the first protrusion of the connecting member and the hole of the housing.
[0008]
According to a fourth aspect of the present invention, there is provided the fixing device according to the third aspect, wherein each terminal of each heater is provided with a notch, and the connecting member is provided with each notch. A fourth protrusion that fits into the
When the fourth projecting portion of the connecting member is in a state of being inserted into each notch portion, the side end portion of each heater terminal portion is in contact with the second and third projecting portions. It is.
[0009]
According to a fifth aspect of the present invention, there is provided an image forming apparatus for forming an electrostatic latent image on a photosensitive drum as a toner image on a sheet, and for fixing an unfixed toner image on the sheet. A fixing device according to any one of claims 4 to 4 is provided.
[0010]
According to these configurations, since the respective terminal portions of the plurality of heaters are integrally connected by a connecting member, workability in the heater insertion into the internal heat roller, and when mounting a plurality of heaters in the fixing device In addition, the connecting member can be removed from each terminal when a heater fails, and only the failed heater can be replaced among the multiple heaters, reducing the cost required for repairing the heater failure. can do.
[0011]
In addition , since a plurality of heaters can be electrically connected to the fixing device at once, the workability when the heater is electrically connected to the fixing device is improved.
[0012]
Further , since the positioning of the plurality of heaters with respect to the housing of the fixing device can be performed at once, the workability when attaching the heater to the housing of the fixing device is improved.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a fixing device and an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a schematic configuration of an image forming apparatus according to the present invention. As shown in FIG. 1, in this copying machine (an example of an image forming apparatus) 1, a photosensitive drum 4 that rotates in a direction A in the figure is uniformly charged by a charging unit 3 in a main body housing 2, and an original document An electrostatic latent image is formed on the photosensitive drum 4 by a laser beam from a laser scanning unit (not shown) based on the original image read by the reading unit 5, and toner is attached to the electrostatic latent image by the developing device 7. Thus, a toner image is formed.
[0014]
The sheet is conveyed from the sheet feeding mechanism 9 via the sheet conveyance path 10 toward the photosensitive drum 4 on which the toner image is formed as described above, and the toner image on the surface of the photosensitive drum 4 is transferred to the sheet. . The sheet on which the toner image has been transferred is separated from the photosensitive drum 4 and conveyed to a fixing device 12 having a heat roller 121 and a pressure roller 122 to fix the toner image. The sheet that has passed through the nip portion of the heat roller 121 and the pressure roller 122 is directly discharged to the discharge unit 14 by the discharge roller pair 13 or is conveyed in the sheet conveyance direction by the branch member 16 provided at the branch point of the sheet conveyance path 15. Are switched and conveyed to the switchback unit 17, and after the paper is reversed, the toner image is transferred to the back side again at the transfer position of the photosensitive drum 4, and double-sided copied and discharged to the discharge unit 14.
[0015]
Two heaters 123 and 124 are built in the heat roller 121 of the fixing device 12, and the two heaters are integrally connected to each other by connecting members described later. Such connection between the terminal portions is a feature of the present invention.
[0016]
A cleaning unit 18 removes residual toner and the like on the photosensitive drum 4. Reference numeral 19 denotes a document transport unit that transports a document to the document reading unit 5 in order to read a document image. The paper feed mechanism 9 is detachably attached to the copying machine main body 2 and includes paper feed cassettes 91, 92, 93, 94 for storing paper, and a paper feed tray 95 provided thereabove. These are connected to the developing unit 7 and the photosensitive drum 4 by the paper conveyance path 10.
[0017]
The connection structure of the heater built in the heat roller 121 of the fixing device 12 will be described. FIG. 2 is a view showing attachment of a connecting member to each terminal portion provided in the heater, and FIG. 3 is a view showing a state where two heaters connected to the terminal portion are inserted into the heat roller. Terminal portions 125 and 126 are provided at end portions of the heaters 123 and 124 built in the heat roller 121, and hole portions 125a and 126a are formed in these terminal portions. These terminal portions 125 and 126 are integrally connected by a connecting member 130 having conductivity.
[0018]
The connecting member 130 is attached to the terminal portions 125 and 126 with the side surface of the connecting member 130 in contact with the side surface of the terminal portions 125 and 126 and the hole portion 125a of the terminal portion 125 and the hole portion 130a of the connecting member 130. In the same manner, the screw 131 is inserted into the hole 126a of the terminal 126 and the hole 130b of the connecting member 130.
[0019]
Further, lead wires 127 and 128 for electrically connecting the heaters 123 and 124 to the power supply unit (not shown) of the fixing device 12 are provided at the ends of the heaters 123 and 124 where the terminal portions 125 and 126 are not provided. Is provided. By providing a switch (not shown) between each of the lead wires 127 and 128 and the power supply unit, on / off control can be performed for each heater of the heaters 123 and 124, and fine temperature adjustment is possible. Yes.
[0020]
When the heaters 123 and 124 are inserted into the heat roller 121, the heaters 123 and 124 are inserted into the heat roller 121 from the end portions of the connected terminal portions 125 and 126.
[0021]
In the description of the heater connection structure using FIGS. 2 and 3, the connection between the terminal portions 125 and 126 and the connection member 130 and the insertion state of the heaters 123 and 124 into the heat roller interior 121 are clarified. Accordingly, since the shapes of the terminal portion and the connecting member are simplified, the shapes of the terminal portion and the connecting member described later are different.
[0022]
Next, the terminal portion of the heater, the connecting member, and the fixing device housing portion connected to the connecting member will be described in detail. 4A is a front view showing a fixing device housing portion connected to the coupling member, FIG. 4B is a front view of the heat roller, and FIG. 5A is a plan view showing the fixing device housing portion connected to the coupling member. (B) is a plan view of the heat roller, FIG. 6 (a) is a side sectional view showing a fixing device housing portion connected to the connecting member, and (b) is a side sectional view of the heat roller.
[0023]
The terminal portion 126 of the heater 124 is made of a conductive plate-like member, and has a notch portion 126b as shown in FIG. 6B. Further, the terminal portion 125 of the heater 123 is also made of a conductive plate-like member, and has a notch portion similar to the terminal portion 126 although not particularly shown. On the other hand, the connecting member 130 has the holes 130 a and 130 b as described above, and the protrusion 130 c that is connected to the fixing device 12 and positions the heaters 123 and 124 with respect to the fixing device 12. Further, the connecting member 130 has projecting portions 130d, 130e, and 130f to facilitate positioning of the terminal portions 125 and 126 with respect to the connecting member 130. The side portions of the terminal portions 125 and 126 abut against the protruding portions 130d and 130e, and the protruding portion 130f is fitted into the notches of the terminal portions 125 and 126, so that the terminal portions 125 and 126 with respect to the connecting member 130 are provided. Is positioned.
[0024]
Further, the connecting portion 135 which is a fixing device housing portion connected to the connecting member 130 is made of a conductive member. The connecting portion 135 is provided with a hole 135a at a position corresponding to the protruding portion 130c of the connecting member 130, and is formed in a shape that allows the protruding portion 130c of the connecting member 130 to be fitted. By fitting the connecting portion 135 and the protruding portion 130c, the heaters 123 and 124 are positioned with respect to the fixing device housing, and the heaters 123 and 124 and the fixing device 12 are electrically connected. Further, the heaters 123 and 124 can be positioned with respect to the fixing device 12 also when the protruding portion 130d of the connecting member 130 contacts the inner wall 135b of the connecting portion 135 and the protruding portion 130e contacts the inner wall 135c. Yes.
[0025]
The present invention is not limited to the configuration of the above embodiment, and various modifications can be made. For example, in the above-described embodiment, the connection between the terminal portions 125 and 126 and the connecting member 130 is performed by the screw 131, but the present invention is not limited to this configuration, and the terminal portions 125, Any member other than the screw 131 can be used as long as it can detachably connect the connecting member 130 to 126.
[0026]
Moreover, in the said embodiment, fitting with the protrusion part 130c of the connection member 130 and the hole 135a of the connection part 135, and contact | abutting with the protrusion parts 130d and 130e of the connection member 130, and the inner walls 135b and 135c of the connection part 135 are carried out. Thus, the positioning of the heaters 123 and 124 with respect to the fixing device 12 is performed. However, the configuration for performing the positioning is not limited to this. For example, the positioning is performed only by fitting the protrusion 130c and the hole 135a. Positioning may be performed.
[0027]
Moreover, although the case where the two heaters 123 and 124 are incorporated in the heat roller 121 is shown in the above embodiment, the present invention can be applied to the case where the heat roller 121 includes three or more heaters. Applicable.
[0028]
Further, the heaters 123 and 124 may be configured to be electrically connected to the power supply unit in series via the connecting member 130, and the heaters 123 and 124 may be simultaneously turned on / off. The material and shape of the connecting member 130 are not limited to those shown in the above embodiment, and the connecting member 130 may be attached to both ends of the heaters 123 and 124.
[0029]
【The invention's effect】
As described above, according to the present invention, since the terminal portions of the plurality of heaters are integrally connected by the connecting member, workability when the heater is inserted into the heat roller and the plurality of heaters are attached to the fixing device. In addition, the connecting member can be removed from each terminal portion and the failed heater can be replaced when the heater fails, so that the cost required for repairing the heater failure can be reduced.
[0030]
Further, since the heater is electrically connected to the fixing device by the connecting member can be electrically connected to the fixing device in a lump a plurality of heaters, operability for electrical connection is improved heater fixing device .
[0031]
Further, if the heaters are positioned with respect to the fixing device by the connecting means, the plurality of heaters can be positioned with respect to the fixing device at a time, and workability when the heaters are attached to the fixing device is improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a schematic configuration of an image forming apparatus according to the present invention.
FIG. 2 is a diagram illustrating attachment of a connecting member to each terminal portion provided in a heater.
FIG. 3 is a view showing a state in which two heaters having terminal portions connected to each other are inserted into a heat roller.
4A is a front view showing a fixing device housing portion connected to a connecting member, and FIG. 4B is a front view of a heat roller.
5A is a plan view showing a fixing device housing portion connected to a connecting member, and FIG. 5B is a plan view of a heat roller.
6A is a side sectional view showing a fixing device housing portion connected to a connecting member, and FIG. 6B is a side sectional view of a heat roller.
[Explanation of symbols]
1 Copying machine (image forming device)
DESCRIPTION OF SYMBOLS 12 Fixing device 121 Heat roller 122 Pressure roller 123 Heater 124 Heater 125 Terminal part 126 Terminal part 130 Connection member 130c Protrusion part 131 Screw 135a Hole part

Claims (5)

A heat roller having a plurality of heaters therein; and a pressure roller that presses the sheet on which the unfixed toner image has been transferred onto the surface of the heat roller. In a fixing device for fixing an image on paper,
Each terminal part provided in each of the plurality of heaters is integrally connected and electrically connected to each other, and includes a connecting member that can be detached from each terminal part,
The connecting member has a first protrusion that fits into a hole provided in a housing of the fixing device, and the heaters are connected to the fixing device by fitting the first protrusion and the hole. A fixing device configured to be electrically connected to a power supply unit . The connecting member further includes a second projecting portion extending in a direction orthogonal to the projecting direction of the projecting portion, and the second projecting portion is in a state in which the first projecting portion is fitted in the hole of the housing. The fixing device according to claim 1, wherein the fixing device contacts the housing at a certain time . A heat roller having a plurality of heaters therein; and a pressure roller that presses the sheet on which the unfixed toner image has been transferred onto the surface of the heat roller. In a fixing device for fixing an image on paper,
It is possible to attach to and remove from each terminal portion provided in each of the plurality of heaters, and includes a connecting member that connects and electrically connects these terminal portions together,
The connecting member includes a first protrusion that fits into a hole provided in the housing of the fixing device, and a hole provided in a side wall of the housing that extends in a direction orthogonal to the protrusion direction of the protrusion. When the first protrusion is in a fitted state, the second protrusion comes into contact with the side wall, and when the first protrusion is fitted in the hole, the bottom of the housing is abutted. A third projecting portion in contact therewith,
A fixing device in which each heater is electrically connected to a power supply unit of the fixing device by fitting the first protruding portion of the connecting member and the hole of the housing . Each terminal of each heater is provided with a notch, and the connecting member further includes a fourth protrusion that fits into each notch.
The side end portions of the heater terminal portions are in contact with the second and third protrusion portions when the fourth protrusion portion of the connecting member is in a state of being inserted into the notch portions. Item 4. The fixing device according to Item 3 . An image forming apparatus that forms an electrostatic latent image on a photosensitive drum on a sheet as a toner image,
An image forming apparatus comprising the fixing device according to claim 1 for fixing an unfixed toner image on a sheet.

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