This application claims the priority benefit of Korean Patent Application No. 10-2011-0129768 under 35 U.S.C. §119 from, filed on Dec. 6, 2011, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
1. Field
The following description relates to a fixing device for use in an image forming apparatus, and more particularly, to a fixing device for use in an image forming apparatus, where the fixing device includes a pressing unit with a carbon nanotube heating layer.
2. Description of the Related Art
Electrophotographic image forming apparatuses such as, printers, copiers, and facsimile machines, for example, are generally equipped with fixing devices to fix an image onto a print medium.
A typical fixing device includes a heating unit (for example, a heating roller) and a pressing unit (for example, a pressing roller) that together form a fixing nip by pressing against each other. The heating unit may include a heat source, such as a heating lamp, a resistive heating member, or a ceramic heater, for example. While a print medium is being passed through the fixing nip, an image on the print medium may be fixed onto the print medium by heat provided by the heating unit and pressure applied by the fixing nip.
Before the print medium arrives in the fixing nip, the fixing nip, which is disposed between the heating unit and the pressing unit, may already be heated to an appropriate target temperature for fixing an image. During the heating of the fixing nip, part of the heat provided by the heat source of the heating unit may also be transmitted to the inside of the pressing unit, which results in heat loss.
Such heat loss may lead to an increase in the power consumption of the fixing device and deterioration of the performance of the fixing device.
Additional aspects and/or advantages will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.
Exemplary embodiments address at least the above problems and/or disadvantages and other disadvantages not described above. Also, the exemplary embodiments are not required to overcome the disadvantages described above, and an exemplary embodiment may not overcome any of the problems described above.
The exemplary embodiments provide a fixing device capable of reducing the consumption of power and improving performance by reducing heat loss and an image forming apparatus having the fixing device.
According to an aspect of the exemplary embodiments, a fixing device, which is included in an electrophotographic image forming apparatus, includes a heating unit which comprises a first heat source to heat an unfixed image on a print medium, and a pressing unit which forms a fixing nip by contacting the heating unit, where the pressing unit comprises a carbon nanotube heating layer as a second heat source to heat the unfixed image.
The carbon nanotube heating layer may be formed by mixing an elastic material and carbon nanotubes.
The elastic material may be liquid silicon rubber (LSR).
The carbon nanotube heating layer may be formed by mixing LSR and the carbon nanotubes in a mass ratio of approximately 95:5 to approximately 85:15.
The pressing unit may include a shaft member which is cylindrical, an elastic layer which surrounds the shaft member, a carbon nanotube heating layer which surrounds the elastic layer, and an anti-adhesion layer which surrounds the carbon nanotube heating layer.
The pressing unit may also include an adiabatic layer which is disposed between the elastic layer and the carbon nanotube heating layer, and an electrically insulating layer which is disposed between the carbon nanotube heating layer and the anti-adhesion layer.
The pressing unit may include a sleeve member, an elastic layer which surrounds the sleeve member, a carbon nanotube heating layer which surrounds the elastic layer, and an anti-adhesion layer which surrounds the carbon nanotube heating layer.
The pressing unit may also include an adiabatic layer which is disposed between the elastic layer and the carbon nanotube heating layer, and an electrically insulating layer which is disposed between the carbon nanotube heating layer and the anti-adhesion layer.
The sleeve member may be elastically supported against the pressing unit.
The sleeve member may be formed of polyimide.
The heating unit may include a first heat source and a belt member which accommodates the first heat source therein and is placed in contact with the pressing unit.
The heating unit may also include a pressing frame which is disposed in the belt member and presses the belt member against the pressing unit.
The heating unit may include a first heat source and a pipe member which accommodates the first heat source therein and is placed in contact with the pressing unit.
The heating unit may include a first heating roller which is placed in contact with the pressing unit, a second heating roller which is distant apart from the first heating roller and accommodates the first heat source therein, and a heat transfer belt which surrounds the first heating roller and the second heating roller.
The first heat source may be at least one of a heating lamp, a resistive heating material, and a ceramic heater.
According to another aspect of the exemplary embodiments, an electrophotographic image forming apparatus includes a fixing device to fix an unfixed image, where the fixing device includes a heating unit which comprises a first heat source to heat an unfixed image on a print medium, and a pressing unit which forms a fixing nip by contacting the heating unit, where the pressing unit comprises a carbon nanotube heating layer as a second heat source to heat the unfixed image.
The above and/or other aspects will be more apparent by describing certain exemplary embodiments with reference to the accompanying drawings, in which:
Exemplary embodiments are described in greater detail with reference to the accompanying drawings.
In the following description, the same drawing reference numerals are used for the same elements even in different drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of the exemplary embodiments. Thus, it is apparent that the exemplary embodiments can be carried out without those specifically defined matters. Also, well-known functions or constructions are not described in detail since they would obscure the exemplary embodiments with unnecessary detail.
Referring to
The heating unit 110 and the pressing unit 120 may be arranged to face and contact each other, and may form a fixing nip N. The fixing nip N may correspond to the area of contact between the heating unit 110 and the pressing unit 120. While being passed through the fixing nip N, a print medium may be properly heated and pressed by the fixing device 100 so that an image may be fixed onto the print medium.
The heating unit 110 includes a belt member 111, a nip formation member 112, a pressing frame 113, and a first heat source 114.
The belt member 111 may be formed in the shape of a belt, and may be hollow in the middle. The belt member 111 may be disposed to be in contact with the pressing unit 120, and may thus rotate along with the pressing unit 120 during the rotation of the pressing unit 120. The belt member 111 may include a base member (not illustrated) which is pipe-shaped, an elastic layer (not illustrated) which covers the base member, and an anti-adhesion layer (not illustrated) which covers the elastic layer. The base member may be formed of a metallic material with high thermal conductivity such as steel use stainless (SUS), or nickel, for example.
The nip formation member 112 may be disposed between the pressing frame 113 and the belt member 111, and may transfer the pressing force of the pressing frame 113 to the belt member 111. The nip formation member 112 may be disposed to cover at least a part of the belt member 111 which forms the fixing nip N. The nip formation member 112 may have a flat bottom with a predetermined width. The fixing nip N may be formed flat in conformity with the flat bottom of the nip formation member 112. For example, the nip formation member 112 may be formed of a heat-resistant plastic material such as a liquid crystal polymer (LCP).
The pressing frame 113 may be disposed in the belt member 111 to surround the first heat source 114. A plurality of apertures (not illustrated) may be formed along the pressing frame 113 such that heat generated by the first heat source 114 may be transferred to the belt member 111 without being interfered with by the pressing frame 113. The pressing frame 113 may be elastically supported against the pressing unit 120 by an elastic member (not illustrated) such as a coil spring, or a plate spring, for example. The fixing nip N may be formed by the pressing force provided by the elastic member.
The first heat source 114 may be disposed in the middle of the belt member 111. For example, the first heat source 114 may be implemented as a heating lamp or a resistive heating member. The fixing nip N between the pressing unit 110 and the pressing unit 120 may be heated by the heat generated by the first heat source 114, and thus, an unfixed image on the print medium may be heated while passing the print medium through the fixing nip N.
The pressing unit 120 includes a shaft member 121, which is formed in a cylindrical shape, an elastic layer 122, which surrounds the shaft member 121, a carbon nanotube heating layer 124, which is formed on the elastic layer 122, and an anti-adhesion layer 126, which is formed on the carbon nanotube heating layer 124.
The shaft member 121 may be disposed at the center of the pressing unit 120, and may be rotatably supported. The shaft member 121 may be formed of a metallic material or a non-metallic material, and a rigid material. The elastic layer 122 may be formed of an elastic material such as rubber, for example. Due to the elastic layer 122, the pressing unit 120 may be compressed or deformed in the fixing nip N. The anti-adhesion layer 126 may be provided on the outermost side of the pressing unit 120, and may allow the print medium to be easily detached from the pressing unit 120.
The carbon nanotube heating layer 124 may be formed by mixing an elastic material and carbon nanotubes in a predetermined ratio. For example, liquid silicon rubber (LSR) may be used as the elastic material, and the carbon nanotube heating layer 124 may be formed by mixing LSR and carbon nanotubes in a mass ratio of approximately 95:5 to approximately 85:15 so that the carbon nanotube heating layer 124 may have appropriate levels of elasticity and resistivity.
Since the carbon nanotube heating layer 124 contains LSR as its main component, the carbon nanotube heating layer 124 may have elasticity. Accordingly, the carbon nanotube heating layer 124 may be compressively deformed in the fixing nip N along with the elastic layer 122.
Since the carbon nanotube heating layer 124 also contains carbon nanotubes as an auxiliary component, the carbon nanotube heating layer 124 may have the properties of a resistive heating material. Accordingly, in response to the application of a voltage to the carbon nanotube heating layer 124, the carbon nanotube heating layer 124 may generate heat.
Due to the above-mentioned properties of the carbon nanotube heating layer 124, the carbon nanotube heating layer 124 may serve as a second heat source. That is, during the fixing of an image on the print medium, heat may be generated not only by the first heat source 114 of the heating unit 110, but also the second heat source, i.e., the carbon nanotube heating layer 124 of the pressing unit 120, may be transmitted to the fixing nip N between the heating unit 110 and the pressing unit 120.
Because the fixing nip N is heated by both the first heat source 114 and the second heat source 124, the fixing nip N may be heated to a target temperature for fixing an image on the print medium faster than when the fixing device 100 is equipped with the first heat source 114 only. Accordingly, it is possible to reduce not only the warm-up time (WUT) for driving the fixing device 100, but also first page print-out time (FPOT). Therefore, it is possible to improve the performance of the fixing device 100.
Referring to
The adiabatic layer 123 may reduce the amount of heat transmitted from the carbon nanotube heating layer 124 to the shaft member 121 and the elastic layer 122. Due to the adiabatic layer 123, heat loss may be further reduced. The electrically insulating layer 125 may protect the rest of the fixing device 100 and a user against a current that flows through the carbon nanotube heating layer 124.
Referring to
The pressing unit 220 may be the same as the pressing unit 120 illustrated in
The heating unit 210 includes a belt member 211, a nip formation member 212, a pressing frame 213, and a first heat source 214. The belt member 211, the nip formation member 212, and the pressing frame 213 may be the same as their respective counterparts illustrated in
Referring to
The pressing unit 320 may be the same as the pressing unit 120 illustrated in
The heating unit 310 includes a pipe member 311 and a first heat source 314. The pipe member 311 may be formed of a metal such as aluminum, etc. The pipe member 311 and the pressing unit 320 may contact each other, and may thus form a fixing nip. The first heat source 314 may be disposed in the middle of the pipe member 311. For example, the first heat source 314 may be implemented as a heating lamp or a resistive heating material.
Referring to
The pressing unit 420 may be the same as the pressing unit 120 illustrated in
The heating unit 410 includes a first heating roller 430 which is disposed opposite to the pressing unit 420 and forms a fixing nip along with the pressing unit 420, a second heating roller 440 which is disposed apart from the first heating roller 430, and a heat transfer belt 450 which is rotatably wound on the first heating roller 430 and the second heating roller 440. The second heating roller 440 includes a pipe member 441, which is cylindrical, and a first heat source 442, which is contained in the pipe member 441. The pipe member 441 may be formed of a metal with high thermal conductivity such as aluminum, for example. The heat transfer belt 450 may be formed of a material such as polyimide, for example. The heat generated by the first heat source 442 in the second heating roller 440 may be transferred to the fixing nip between the heating unit 410 and the pressing unit 420 via the heat transfer belt 450, and may thus be used for heating an unfixed image.
As illustrated in
Referring to
The heating unit 510 and the pressing unit 520 may be disposed to face and contact each other, and may form a fixing nip N. While being passed through the fixing nip N, a print medium may be properly heated and pressed by the fixing device 100 so that an image may be fixed onto the print medium.
The heating unit 510 includes a pipe member 511 and a first heat source 514.
The pipe member 511 may be formed as a hollow pipe, and may contain the first heat source 514 therein. The pipe member 511 may include a base member (not illustrated) which is pipe-shaped, an elastic layer (not illustrated) which covers the base member, and an anti-adhesion layer (not illustrated) which covers the elastic layer. The base member may be formed of a metallic material with high thermal conductivity such as aluminum, for example.
The first heat source 514 may be disposed in the middle of the belt member 511. For example, the first heat source 514 may be implemented as a heating lamp or a resistive heating member. An unfixed image on the print medium may be heated via the pipe member 511 while passing the print medium through the fixing nip N.
The pressing unit 520 includes a belt member 530, a nip formation member 540, and a pressing frame 550.
The nip formation member 540 may be disposed between the pressing frame 550 and the belt member 530, and may transfer the pressing force of the pressing frame 550 to the belt member 530. The nip formation member 540 may be disposed to cover at least a part of the belt member 530, which forms the fixing nip N. The nip formation member 540 may have a flat part with a predetermined width. The fixing nip N may be formed flat in conformity with the flat part of the nip formation member 540. For example, the nip formation member 540 may be formed of a heat-resistant plastic material such as a liquid crystal polymer (LCP), etc.
The pressing frame 550 may be disposed in the belt member 530, and may be elastically supported against the heating unit 510 by an elastic member (not illustrated) such as a coil spring or a plate spring, for example. The fixing nip N may be formed by the pressing force provided by the elastic member.
The belt member 530 may be formed in the shape of a belt, and may be hollow in the middle. The belt member 530 may be disposed to be in contact with the heating unit 510, and may thus rotate along with the heating unit 510 during the rotation of the heating unit 510.
Referring to
The sleeve member 531 may be formed of a rigid material. For example, the sleeve member 531 may be formed of polyimide, for example. The elastic layer 532 may be formed of an elastic material such as rubber, for example, and may thus be compressively deformed in the fixing nip N. The anti-adhesion layer 536 may be provided on the outermost side of the pressing unit 520 and may allow the print medium to be easily detached from the belt member 530.
The carbon nanotube heating layer 534 may be formed by mixing an elastic material and carbon nanotubes in a predetermined ratio. For example, LSR may be used as the elastic material, and the carbon nanotube heating layer 534 may be formed by mixing LSR and carbon nanotubes in a mass ratio of approximately 95:5 to approximately 85:15 so that the carbon nanotube heating layer 534 may have appropriate levels of elasticity and resistivity.
The fixing device 500, like the fixing device 100 illustrated in
Referring to
The heating unit 610 includes a first heating roller 660, a second heating roller 670, and a heat transfer belt 680. The first heating roller 660, the second heating roller 670, and the heat transfer belt 680 may be the same as their respective counterparts illustrated in
The pressing unit 620 may be the same as its counterpart illustrated in
A fixing device according to an exemplary embodiment, which is equipped with first and second heat sources, and a related-art fixing device which is equipped with the first heat source only were tested for the performance of increasing temperature. During the test, a fixing device (hereinafter referred to as the fixing device according to the present description) having the structure illustrated in
Referring to Table 1, measurement data obtained from the related-art fixing device is as shown in three rows in the middle, and measurement data obtained from the fixing device according to the present description is as shown in two rows at the bottom.
In the case of the related-art fixing device, when the initial temperature of the pressing unit of the related-art fixing device is 25° C., the related-art fixing device has a temperature increase rate of 12.8° C./sec in the non-nip area and a temperature increase rate of 10.3° C./sec in the nip area. On the other hand, in the case of the fixing device according to the present description, when the power consumption of the carbon nanotube heating layer of the fixing device according to the present description is 450 W, the fixing device according to the present description has a temperature increase rate of 20.3° C./sec in the non-nip area and a temperature increase rate of 22.2° C./sec in the nip area.
As shown in Table 1, the fixing device according to the present description has a higher temperature increase rate in both the nip area and the non-nip area than the related-art fixing device.
Referring to Table 1 and
The amount of power consumed by each of the fixing device according to the present description and the related-art fixing device to reach a target temperature was calculated based on the measurement data shown in Table 1, and the results of the calculation are as shown in Table 2 below.
Referring to Table 2, the fixing device according to the present description consumes much less electric energy than the related-art fixing device to reach the same target temperature. That is, the power consumption of the fixing device according to the present description may be less than the power consumption of the related-art fixing device.
Referring to
A print medium may be picked up from the print medium supply unit 20, may be injected into the main body 10, and may be transferred along a path P. An image may be transferred onto the print medium while the print medium is being passed through a transfer nip between the image carrier 31 and the transfer unit 40. The transferred image may be fixed while the print medium is being passed through a fixing nip between a heating unit 51 and a pressing unit 52 of the fixing device 50. Then, the print medium may be ejected from the main body 10.
The fixing device 50 may have the same structure as one of the fixing devices 100, 200, 300, 400, 500, and 600 illustrated in
The image forming apparatus 1 may improve the performance of fixing (for example, a reduced FPOT) and reduce the consumption of power, as compared to a related-art image forming apparatus.
The foregoing exemplary embodiments and advantages are merely exemplary and are not to be construed as limiting. The present teaching can be readily applied to other types of apparatuses. Also, the description of the exemplary embodiments is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.
Number | Date | Country | Kind |
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10-2011-0129768 | Dec 2011 | KR | national |