Fixing heater and imaging equipment

Abstract

The utility model provides a fixing heater, which is characterized in that the edge thickness of a working surface of the fixing heater is larger than the middle thickness, and the edge and the middle straight surface form a recess as a lubricating oil storage area. The utility model also provides an imaging device, which comprises the photographic fixing heater; the fixing heater is located on the inner side of the fixing film; and the pressure roller is positioned outside the fixing film, and a gap is formed between the pressure roller and the fixing film for printing paper to pass. According to the utility model, the retention time of the lubricating grease between the heat-conducting film and the ceramic heater is prolonged, and the service life of the printer is prolonged.

Description

Technical Field

[0001] The utility model relates to a fixing heating technology, and more particularly to a fixing heater and an imaging device for a copier or a printer. Background Art

[0002] A heat-fixing device used in copiers and printers consists of a cylindrical thermally conductive film, a ceramic heater in contact with the inner wall of the film, grease to lubricate the heater's working surface and the film's inner wall, and a pressure roller that forms a nip between the film and the ceramic heater. Paper, to which toner has been electrostatically attached, is conveyed through the gap between the pressure roller and the film. The toner is heated and melted, and the pressure roller presses the toner into the gap between the paper and the film. This type of heat-fixing device (referred to as a film-heating method) has a very low heat capacity, resulting in fast warm-up to the fixing temperature, short printing wait times, and low power consumption while waiting for a print command.

[0003] The working surface of existing ceramic heaters is flat. While a flat working surface minimizes frictional resistance and facilitates the operation of the fixing film, it also reduces friction between the ceramic heater and the inner wall of the cylindrical thermally conductive film. However, after 40 hours or more of operation while the heater is heating, the lubricant applied to the surface of the ceramic heater can be squeezed out and lost. This increases friction between the thermally conductive film and the ceramic heater, resulting in the thermally conductive film becoming unable to rotate or being damaged by torsion, ultimately causing the printer to malfunction. Utility Model Content

[0004] In view of the problems in the background technology, the present invention proposes a fixing heater, comprising: a working surface of the fixing heater having an edge thickness greater than a middle thickness, and a concave portion formed between the edge and the middle flat surface as a lubricating oil storage area.

[0005] Furthermore, the edge of the working surface is in the shape of an inwardly concave arc, an outwardly convex arc, or a stepped shape.

[0006] Furthermore, the heater also includes: a substrate; a conductor layer, which is arranged on the substrate, and electrodes are arranged on the conductor layer; a resistor layer, which covers the conductor layer, and a thermistor is arranged on the resistor layer; an insulating layer, which covers the resistor layer; and a thermal circuit breaker for cutting off power supply is connected in series to the circuit of the heater.

[0007] Furthermore, the heating resistor is distributed in the middle of the short side of the heater, and two or more heating resistors are distributed along the long side of the heater.

[0008] Furthermore, a plurality of heating resistors are connected in series or in parallel between one or more electrodes of the conductor layer.

[0009] The utility model also provides an imaging device, comprising: the fixing heater as described above; a fixing film, the fixing heater is located inside the fixing film; and a pressure roller is located outside the fixing film, with a gap between the two for printing paper to pass through.

[0010] The technical effects of the utility model include: prolonging the retention time of lubricating grease between the heat-conducting film and the ceramic heater, and prolonging the working life of the printer. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to make the present invention more easily understood, the present invention will be described in more detail with reference to the specific embodiments shown in the accompanying drawings. These drawings only depict typical embodiments of the present invention and should not be considered as limiting the scope of protection of the present invention.

[0012] Figure 1 This is a cross-sectional view of a heater assembly to which the heater of the present invention is applied.

[0013] Figure 2 This is an exploded view of the heater.

[0014] Figure 3 This is a diagram of the heater of the present invention after assembly.

[0015] Figure 4 A cross-sectional view of a heater assembly according to the prior art.

[0016] Figure 5 This is a cross-sectional view of an embodiment of a heater assembly of the present invention.

[0017] Figure 6 It is a partial enlarged view of the heater assembly of the present invention.

[0018] Figure 7 It is a partial cross-sectional view of another embodiment of the heater assembly of the present invention.

[0019] Figure 8 It is a partial cross-sectional view of another embodiment of the heater assembly of the present invention.

[0020] Reference numerals

[0021] 1-heater, 2-fixing film, 3-pressure roller, 4-printing paper, 5-heating plate bracket, 6-thermistor, 7-oil storage area, 11-resistance layer, 12-conductor layer, 13-insulating layer, 14-base material. DETAILED DESCRIPTION

[0022] The following describes the implementation methods of the present invention with reference to the accompanying drawings so that those skilled in the art can better understand the present invention and implement it. However, the enumerated embodiments are not intended to limit the present invention. Unless there is a conflict, the following embodiments and the technical features in the embodiments can be combined with each other, and the same components are represented by the same figure marks.

[0023] Figure 1 The figure shows the heater assembly during the printing process, including the heater 1 of the present invention. Heater 1 is located inside a cylindrical fuser film 2. A gap (nip) is left between the fuser film 2 and a pressure roller (elastic pressure roller) 3 for the passage of printing paper 4. As the printing paper 3 passes between the fuser film 2 and the pressure roller 3, heater 1 provides heat, which is then transferred to the printing paper 4 through the fuser film 2. The pressure roller 3 applies pressure, squeezing the softened toner on the printing paper 4 into the gaps between the paper fibers.

[0024] The outer surface of the cylindrical fixing film 2 contacts the printing paper 4, while the inner wall of the fixing film 2 contacts the heater 1. The heater 1 is preferably a thick ceramic film heating element that adheres to the inner wall of the fixing film 2. The pressure roller 3 has a metal core and a flexible silicone outer shell. The printing paper travels through the gap between the pressure roller 3 and the fixing film 2.

[0025] like Figure 2 As shown, heater 1 comprises a ceramic substrate on which a heating circuit and an encapsulating glass layer are arranged. Thermistors 6 are located in the middle of the short side of heater 1, with two or more thermistors distributed along the long sides. A thermal circuit breaker is connected in series with the heater circuit to cut off power when the heater's temperature rise exceeds a set limit.

[0026] Figure 3 The structure of the heater 1 is shown. The heater 1 includes a substrate (made of ceramic) 14, a conductor layer 12, a resistor layer 11, and an insulating layer 13. The substrate 14 is made of aluminum oxide or aluminum nitride ceramic. The conductor layer 12 is arranged on the substrate 14, and electrodes are arranged on the conductor layer 12. Heating resistors are arranged on the resistor layer 11, and the heating resistors can be 2 or more groups. The conductor layer 12 is covered by the resistor layer 11. The resistor layer 11 is covered and encapsulated by the insulating layer 13. The heating circuit distributed on the resistor layer 11 has multiple groups of heating resistors in a symmetrical arrangement, and the heating resistors are connected in series or in parallel between one or more groups of electrodes of the conductor layer, so that heat can be generated simultaneously.

[0027] Figure 3A perspective view of the fuser assembly is shown. The fuser assembly includes a pressure roller 3 and a heater assembly. The pressure roller 3 (a pressure-applying elastic roller) adheres to the outer wall of the fuser film. The pressure roller 3 has a metal core and elastic silicone. The paper's path passes through the gap between the pressure roller 3 and the fuser film 2.

[0028] Figure 4 A cross-sectional view of a heater assembly of the prior art is shown (green represents the heater, red represents the thermal conductive film, purple represents the thermistor, and yellow represents the heater support iron frame). The heater is supported by the heater support frame, the heater is heated by the thermistor, and the heat is conducted to the fixing film. It can be seen from the figure that the area marked by A is completely flat and has no oil storage area. The film oil between the fixing film and the ceramic heater will gradually be squeezed out of the working area due to continuous printing and operation. The lubricating grease will be lost in large quantities due to the squeezing, which will increase the friction between the fixing film and the ceramic heater, resulting in the fixing film being unable to rotate, or the fixing film being damaged due to torque, and ultimately causing the printer to malfunction.

[0029] Figure 5-6 A cross-sectional view of a heater of the present invention is shown in a real-number manner. A sealing glass layer is provided on the ceramic substrate of the ceramic heater 1. The sealing glass layer contacts the inner wall of the fixing film 2. This contact surface of the ceramic heater 1 is called the heater working surface, wherein the edge thickness of the ceramic heater working surface is greater than the middle thickness, the middle is low and the two sides are high, and the concave interior formed forms a lubricating oil storage area 7. That is, the middle plane of the heater working surface is a plane, and the two sides along the long side of the heater are higher than the middle. The structure of the ceramic heater working surface of the present invention in which the upper edge is higher than the middle establishes a lubricating oil storage area on each side of the ceramic heater, thereby extending the retention time of the lubricating grease between the thermal conductive film and the ceramic heater. Whether a certain amount of lubricating grease can exist between the ceramic heater and the thermal conductive film determines the performance and service life of the entire fixing heater, thereby greatly extending the service life of the fixing heater.

[0030] Preferably, the maximum height of the edge of the heater working surface does not exceed the edge of the ceramic heater support to prevent the sharp edge of the heater 1 from contacting the inner wall of the fixing film 2 .

[0031] Figure 7 This figure shows a cross-sectional view of a heater according to the present invention. The lubricating oil reservoir 7 is formed by a flat center area and arc-shaped end areas. Specifically, the center plane of the heater's working surface is flat, while the two edges along the heater's longitudinal direction are arc-shaped and convex inward.

[0032] Figure 8A cross-sectional view of a heater according to the present invention is shown. The lubricating oil reservoir 7 is formed by a flat center area and stepped protrusions at the ends. Specifically, the center plane of the heater's working surface is flat, while the two sides along the heater's longitudinal direction are elevated with convex steps.

[0033] The embodiments described above are merely preferred embodiments of the present invention. The phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments" used in this specification may refer to one or more of the same or different embodiments of the present disclosure. Any common changes and substitutions made by those skilled in the art within the scope of the present invention are intended to be encompassed within the scope of protection of the present invention.

Claims

1. A fixing heater, characterized in that: include: The thickness of the edge of the working surface of the fixing heater is greater than the thickness in the middle, and a depression is formed between the edge and the middle flat surface as a lubricating oil storage area.

2. The fixing heater according to claim 1, wherein The edge of the working surface is in an inwardly concave arc shape, an outwardly convex arc shape or a stepped shape.

3. The fixing heater according to claim 1, wherein Also includes: substrate; a conductor layer, which is arranged on the substrate, and electrodes are arranged on the conductor layer; a resistance layer covering the conductor layer, wherein a thermistor is arranged on the resistance layer; an insulating layer covering the resistive layer; A thermal circuit breaker for cutting off the power supply is connected in series with the heater's circuit.

4. The fixing heater according to claim 3, wherein The heating resistors are distributed in the middle of the short side of the heater, and two or more heating resistors are distributed along the long side of the heater.

5. The fixing heater according to claim 4, wherein A plurality of heating resistors are connected in series or in parallel between one or more electrodes of the conductor layer.

6. An imaging device, characterized in that include: The fixing heater according to any one of claims 1 to 5; a fixing film, wherein the fixing heater is located inside the fixing film; The pressure roller is located on the outside of the fixing film, and there is a gap between the two for the printing paper to pass through.

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