WO2012068978A1

WO2012068978A1 - Fuser component

Info

Publication number: WO2012068978A1
Application number: PCT/CN2011/082542
Authority: WO
Inventors: 苏健强
Original assignee: 珠海天威飞马打印耗材有限公司
Priority date: 2010-11-25
Filing date: 2011-11-21
Publication date: 2012-05-31
Also published as: CN102063043A; CN102063043B

Abstract

A fuser component comprises a fuser roller (1) and a pressure roller (2) for pressing a printing medium to the fuser roller. A fuser channel providing a passage for the printing medium is formed between the fuser roller (1) and the pressure roller (2). The fuser roller (1) is a solid roller made of magnetically permeable material, the periphery of the end part of the fuser roller (1) is distributed with excitation coils (4, 5), and the axis of the excitation coils (4, 5) essentially overlaps with the axis of the fuser roller.

Description

Fixing unit

Technical field

The present invention relates to a fixing assembly applied to an image forming apparatus such as a laser printer or a copying machine. The present application claims priority to Chinese Patent Application No. 201010558569. filed on Nov. 25, 2010, the entire disclosure of which is incorporated herein by reference.

Background technique

Laser printer is one of the most widely used external computer output devices. It uses the physical and chemical principles of light, electricity and heat to output text or images through interaction. The basic process can be divided into seven steps: charging, exposure, development, transfer, fixing, cleaning, and power-saving. First, the surface of the photosensitive drum is uniformly charged by the charging roller. The laser scanner emits a modulated laser light containing image information to the photosensitive drum to form an electrostatic latent image corresponding to the image to be reproduced on the surface of the photosensitive drum. Then, the toner from the developing roller is adsorbed on the surface of the photosensitive drum to convert the electrostatic latent image into a visible image. With the rotation of the photosensitive drum and the positive voltage applied to the back surface of the recording medium such as paper by the transfer roller, the negatively charged toner forming a visible image on the surface of the photosensitive drum is attracted, and the toner is formed. The image is transferred to a recording medium such as paper. Subsequently, the fixing unit formed by the fixing roller and the pressure roller is inserted, and the toner particles are melted into the fibers of the recording medium under the action of heat and pressure, so that the visible image formed by the carbon powder is completely cured on the recording medium. Such a basic imaging action is completed.

Such a fixing assembly generally includes a fixing roller and a pressure roller, and both the fixing roller and the pressure roller rotate in the recording medium transport direction, and a fixing passage is formed between the pressure roller and the fixing roller, and the recording medium passes through the fixing passage. The visible image formed by the toner is completely cured on the recording medium. In a conventional fixing assembly structure, the fixing roller is usually heated by a heating tube. The heating tube is a resistance heating element disposed inside the fixing roller, generates heat through the inner surface and diffuses to the outer surface until its temperature rises enough to melt the toner (for example, the temperature approaches 100 ° C to 180 ° C), the conventional structure It is necessary to form a cavity in the fixing roller, so that the miniaturization of the fixing roller and the entire fixing assembly is restricted, and the heating efficiency thereof is also low. It is difficult to maintain a uniform and constant heat supply due to the manufacturing accuracy of the resistance heating element distributed inside the small hollow fixing roller, etc., and maintaining a constant temperature value is difficult for a small fixing roller, resulting in poor fixing of the recording medium. In an environment where it is required to quickly start the printer and immediately output a printed image, it is necessary to heat the fixing roller to a predetermined temperature in a short time.

technical problem

The technical problem to be solved by the present invention is to provide a fixing assembly capable of reducing the volume and allowing rapid heating of the fixing roller in view of the drawbacks of the prior art.

Technical solution

In order to solve the above technical problems, the present invention adopts the following technical solution: designing a fixing assembly including a fixing roller and a pressure roller for pressing a printing medium toward the fixing roller, and forming a fixing roller and a pressure roller a fixing passage through which the printing medium passes; wherein the fixing roller is a solid roller made of a magnetic conductive material, and an excitation coil is disposed around an end of the fixing roller, an axis of the exciting coil and an axis of the fixing roller Basically coincident.

Preferably, a set of the exciting coils are distributed around the outer periphery of both ends of the fixing roller.

Preferably, the magnetic conductive material is an iron alloy, a copper alloy, an aluminum alloy, a nickel alloy or a chromium alloy.

As a further improvement of the present invention, the surface of the fixing roller has a coating. The coating can be a Teflon coating. Wherein the outer surface of the coating comprises an end outer surface and an intermediate portion outer surface in contact with the printing medium, the field coil surrounding the end outer surface and forming a clearance fit.

In one embodiment, the roughness of the outer surface of the intermediate portion is less than the roughness of the outer surface of the end portion, and the heat transfer efficiency of the outer surface of the intermediate portion is higher than the heat transfer efficiency of the outer surface of the end portion. The roughness is gradually reduced from the both ends of the fixing roller to the middle, and the change in the roughness can be achieved by controlling the coating application manner, or by controlling the outer surface of the solid roller to machine the roughness. achieve.

In another embodiment, the electrical resistance of the outer surface of the intermediate portion is greater than the electrical resistance of the outer surface of the end portion, and the thermal efficiency of the outer surface of the intermediate portion is higher than the thermal efficiency of the outer surface of the end portion. The change in the resistance is achieved by setting the magnetic conductive material of the solid roller to two or more different resistance values and joining them together by a seamless joining technique, or by controlling the coating method of the surface coating of the fixing roller. achieve.

Preferably, the excitation coil is provided with a temperature sensing element.

Preferably, the exciting coil is a spiral coil.

Beneficial effect

The advantageous effect of the present invention is that since the fixing roller is used instead of the heating tube to heat the fixing roller, rapid heating of the fixing roller can be achieved; at the same time, the exciting coil is disposed at the periphery of the end portion of the fixing roller, so that the fixing roller can be used The solid roll is made to reduce the volume thereof, the miniaturization of the fixing assembly is realized, the manufacturing difficulty and cost of the small heat fixing system are reduced, and the axis of the exciting coil substantially coincides with the axis of the fixing roller, so that the exciting coil heats the fixing roller. More uniform and more efficient heating.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a longitudinal cross-sectional view of an image forming apparatus having a fixing assembly of the present invention.

Figure 2 is a longitudinal cross-sectional view of an embodiment of the fixing assembly of the present invention.

Figure 3 is a front elevational view of the fixing roller (including the exciting coil) in the fixing assembly of Figure 1.

Figure 4 is a perspective view of the fixing roller shown in Figure 2 .

Figure 5 is a schematic view showing the first circuit connection of the fixing roller shown in Figure 2;

Figure 6 is a schematic view showing the second circuit connection of the fixing roller shown in Figure 2;

Figure 7 is a schematic view showing the first driving mode of the fixing roller shown in Figure 2.

Figure 8 is a schematic view showing the second driving mode of the fixing roller shown in Figure 2;

Embodiments of the invention

Embodiment 1

As shown in Fig. 1, the image forming apparatus has the fixing assembly of the present invention. The surface of the photosensitive drum 71 of the image forming apparatus is uniformly charged by the charging roller 72. The exposure unit 73 emits an optical signal containing image information to the photosensitive drum, and forms an electrostatic latent image corresponding to the image to be copied on the surface of the photosensitive drum 71. Then, the toner from the developing roller 74 is adsorbed on the surface of the photosensitive drum 71 to convert the electrostatic latent image into a visible image. With the rotation of the photosensitive drum 71 and the positive voltage applied to the back surface of the recording medium such as paper by the transfer roller 75, the negatively charged toner which forms a visible image on the surface of the photosensitive drum 71 is attracted by the toner. The formed visible image is transferred onto a recording medium such as paper. Subsequently, the fixing unit including the fixing roller 1 and the pressure roller 2 is introduced, and the toner particles are melted into the fibers of the recording medium under the action of heat and pressure, so that the visible image formed by the toner is completely cured on the recording medium. Such a basic imaging action is completed.

A fixing assembly of the present invention includes a fixing roller 1 and a pressure roller 2 that presses a printing medium toward the fixing roller 1, the axes of which are parallel to each other, and the printing medium (for example, paper) can be heated and pressed. The fixing passage between the fixing roller 1 and the pressure roller 2 passes, so that the image is fixed on the printing medium.

As shown in FIGS. 7 and 8, the fixing roller 1 and the pressure roller 2 are driven by a motor 13. The following two driving modes are described: one is as shown in FIG. 7, and the pressure roller 2 is driven to rotate in the recording medium transport direction by the gear 10, and then the fixing roller is driven by the friction between the pressure roller 2 and the fixing roller 1. 1 is rotated in the transport direction of the recording medium; and as shown in Fig. 8, the fixing roller 1 and the pressure roller 2 respectively meshed on the gears 11 and 12 can be moved along the recording medium by the driving and transmission of the gears 11 and 12. The direction of rotation is rotated.

The fixing roller 1 is made of a magnetic conductive material such as an iron alloy, a copper alloy, an aluminum alloy, a nickel alloy or a chromium alloy. The fixing roller 1 can be magnetized by an electromagnetic field and has conductivity such that a current of a predetermined magnitude flows to generate heat.

The fixing roller 1 adopts a cylindrical solid roller, which can reduce the diameter of the fixing roller with respect to the conventional hollow roller. Especially for the fixing roller used in the portable small printing device, the solid roller can simplify the manufacturing process and reduce the manufacturing precision. Thereby reducing costs. In order to improve the release property of the toner image, the surface of the fixing roller 1 is formed with a coating 3 which is preferably a Teflon coating having a coating thickness of about 10 to 50 um. The outer surface of the coating 3 includes a left end outer surface 31 proximate the field coil portion, a right end outer surface 32, and an intermediate portion outer surface 33 that is in contact with the print medium away from the field coil portion, wherein the left end outer surface The roughness of the outer surface 32 of the right end portion 31 is substantially the same, and the roughness of the outer surface 33 of the intermediate portion is smaller than the roughness of the outer surface of the two end portions, which is gradually reduced from the both ends of the fixing roller 1 toward the middle. This change in roughness is achieved by controlling the coating method of the Teflon coating such as thickness and smoothness, or by controlling the roughness of the outer surface of the solid roll made of the magnetically permeable material. The outer surfaces of the two end portions have higher roughness, the contact printing medium area is smaller, and the heat transfer efficiency is lower; the outer portion outer surface 33 has lower roughness, the contact printing medium area is larger, and the heat transfer efficiency is higher.

A plurality of excitation coils 4, 5 (high-frequency induction heating coils) are disposed around the outer ends of the two ends of the fixing roller 1, and the two

excitation coils

4, 5 are respectively spirally wound around the outer surfaces of the both ends. A gap fit is formed and an alternating magnetic flux is generated which changes according to a change in current input from the energy control circuit. A temperature sensing element 9 as shown in FIG. 2 can be disposed on the

exciting coils

4, 5. As shown in Fig. 5, the exciting coil 4 can be connected in series with the exciting coil 5 and connected to the energy control circuit 6. Alternatively, as shown in Fig. 6, the exciting coil 4 is separately connected to the energy control circuit 7, and the exciting coil 5 is separately connected to the energy control circuit 8. The field coils 4, 5 are gap-fitted with the left end outer surface 31 and the right end outer surface 32. The axes of the two

exciting coils

4, 5 substantially coincide with the axis of the fixing roller 1, such that the flux of the fixing roller in the radial direction of the fixing roller is substantially the same during the rotation, so that the surface of the fixing roller is generated in the exciting coil Each part of the electromagnetic field is heated more uniformly.

Since the

exciting coils

4, 5 are located at both end portions of the fixing roller 1, and the heat transfer efficiency of the intermediate portion outer surface 33 of the fixing roller 1 is higher than that of the both end outer surfaces, such an arrangement can make the surface of the fixing roller The temperature is relatively uniform, and the fixing roller is more uniform in heating the printing medium (in the longitudinal direction of the fixing roller), thereby ensuring the fixing effect of the printing medium.

Embodiment 2

The structure of the fixing assembly of the present embodiment is substantially the same as that of the embodiment, and the main feature is that the electric resistance of the outer surface of the intermediate portion of the surface coating of the fixing roller is larger than the resistance of the outer surface of the end portion of the fixing roller 1 Gradually getting bigger in the middle. The change in the resistance can be achieved by setting the magnetic conductive material of the solid roll made of a magnetically permeable material to two or more different resistance values and joining them together by a seamless joining technique. It can also be achieved by controlling the coating method of the conductive Teflon coating on the surface thereof such as thickness. The outer surface of the end has a small electrical resistance, so the thermal efficiency is low; the outer surface of the intermediate portion has a large electrical resistance, so the thermal efficiency is high. Since the exciting coil is located at both ends of the fixing roller, and the thermal efficiency of the outer surface of the intermediate portion of the fixing roller is higher than the outer surfaces of the two end portions, such an arrangement can make the surface temperature of the fixing roller relatively uniform, and the fixing roller pair prints The degree of heating of the medium (in the longitudinal direction of the fixing roller) is also uniform, thereby ensuring the fixing effect of the printing medium.

The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept, for example, a fixing roller. The surface has no coating; or, the fixing roller has an excitation coil only at one end periphery; or the excitation coil is wound around the outer surface of the fixing roller end without forming a clearance fit or the like, which is within the scope of the present invention.

Industrial applicability

The fixing assembly of the present invention realizes rapid heating of the fixing roller, and can form the fixing roller into a solid roller to reduce its volume, realize miniaturization of the fixing assembly, reduce the manufacturing difficulty and cost of the small heat fixing system, and simultaneously fix the fixing. The heating of the rolls is more uniform and the heating efficiency is higher.

Claims

a fixing assembly comprising a fixing roller and a pressure roller that presses the printing medium against the fixing roller, the fixing roller and the pressure roller forming a fixing passage through which the printing medium passes, wherein the fixing roller is A solid roller made of a magnetically permeable material, an excitation coil is disposed around an end of the fixing roller, and an axis of the exciting coil substantially coincides with an axis of the fixing roller.
A fixing assembly according to claim 1, wherein a plurality of said exciting coils are distributed around the outer periphery of both ends of said fixing roller.
The fixing assembly according to claim 1, wherein said magnetic conductive material is an iron alloy, a copper alloy, an aluminum alloy, a nickel alloy or a chromium alloy.
The fixing assembly according to any one of claims 1 to 3, wherein the surface of the fixing roller has a coating.
The fixing assembly of claim 4 wherein said coating is a Teflon coating.
A fixing assembly according to claim 4, wherein said outer surface of said coating comprises an end outer surface and an intermediate portion outer surface in contact with said printing medium, said field coil being wound around said end portion The surface forms a clearance fit.
A fixing assembly according to claim 6, wherein a roughness of an outer surface of said intermediate portion is smaller than a roughness of an outer surface of said end portion, and a heat transfer efficiency of said outer surface of said intermediate portion is higher than said end portion Heat transfer efficiency of the outer surface.
The fixing assembly according to claim 7, wherein said roughness is gradually reduced from the both ends of said fixing roller toward the center, and the change in roughness is achieved by controlling the coating application mode.
A fixing assembly according to claim 7, wherein said roughness is gradually reduced from the both ends of said fixing roller toward the center, and the change in roughness is controlled by controlling the outer surface of said solid roller to be rough. To achieve.
A fixing assembly according to claim 6, wherein an electric resistance of an outer surface of said intermediate portion is greater than an electric resistance of an outer surface of said end portion, and a thermal efficiency of said outer surface of said intermediate portion is higher than a thermal efficiency of said outer surface of said end portion .
A fixing assembly according to claim 10, wherein said change in electric resistance is set by bonding two or more different magnetic resistance materials of said solid roller and joined together by seamless joining technique achieve.
The fixing assembly according to claim 10, wherein said change in electrical resistance is achieved by controlling a coating manner of a surface coating of the fixing roller.
A fixing assembly according to claim 1, wherein said exciting coil is provided with a temperature sensing element.
A fixing assembly according to claim 1, wherein said exciting coil is a spiral coil.