The present invention relates to a fixing device.
In the related art, a fixing device is provided to fix a toner image on a sheet. The fixing device includes a nozzle unit and an opposite electrode. The nozzle unit sprays a fixing solution onto a sheet on which the toner image is formed. The opposite electrode is located at an interval from the nozzle unit. A voltage is applied to the opposite electrode (refer to JP-A-2017-068098).
However, according to the fixing device disclosed in JP-A-2017-068098, mists of the fixing solution sprayed from nozzles are electrically charged. For this reason, the mists of the fixing solution are provided to the sheet, so that the sheet is electrically charged. When the fixing solution is additionally sprayed to the electrically charged sheet, an electrostatic repulsive force is generated between the mists of the fixing solution and the sheet, so that the mists of the fixing solution are difficult to be attracted to the sheet.
Therefore, it is difficult to stably provide the fixing solution to the sheet.
It is therefore an object of the present disclosure to provide a fixing device capable of stably providing a fixing solution sprayed from each of a plurality of nozzles to a sheet even in a case where the sheet is electrically charged.
The opposite electrode has a first flat plate and a plurality of first projections.
The first flat plate extends in a first direction.
The plurality of first projections extends from the first flat plate in a second direction. The second direction is a direction facing from the opposite electrode toward the nozzle unit. The plurality of first projections are aligned in the first direction.
According to the configuration, the plurality of first projections extend from the opposite electrode toward the nozzle unit.
Thereby, in a state where a voltage is applied to the opposite electrode, an electrostatic force is concentrated on a tip end of each of the plurality of first projections.
For this reason, it is possible to form a strong electric field at the tip end of each of the plurality of first projections without increasing the voltage applied to the opposite electrode.
The plurality of first projections are aligned in the first direction.
For this reason, it is possible to stably attract the fixing solution sprayed from each of the plurality of nozzles toward the opposite electrode by the strong electric field formed in the first direction.
As a result, even in a case where the sheet is electrically charged, it is possible to stably provide the fixing solution sprayed from each of the plurality of nozzles to the sheet.
According to the configuration, since the electrode is spaced from the sidewall, it is possible to suppress the sidewall from being electrically charged due to the voltage applied to the opposite electrode.
For this reason, it is possible to suppress mists of the fixing solution sprayed from the nozzle unit from being attracted to the sidewall.
As a result, the nozzle unit can stably spray the fixing solution toward the opposite electrode.
According to the fixing device of the present disclosure, even in a case where the sheet is electrically charged, it is possible to stably provide the fixing solution sprayed from each of the plurality of nozzles to the sheet.
An outline of an image forming apparatus 1 is described with reference to
An image forming apparatus 1 includes a main body housing 2, a sheet feeding unit 3, a photosensitive drum 4, a charging device 5, an exposure device 6, a developing device 7, a transfer device 8, and a fixing device 9.
The main body housing 2 accommodates the sheet feeding unit 3, the photosensitive drum 4, the charging device 5, the exposure device 6, the developing device 7, the transfer device 8, and the fixing device 9.
The sheet feeding unit 3 feeds a sheet S to the photosensitive drum 4. The sheet feeding unit 3 includes a sheet cassette 10, a pickup roller 11, and a conveying roller 12. The sheet cassette 10 accommodates sheets S. The sheet S is, for example, a printing sheet. The pickup roller 11 conveys the sheet S in the sheet cassette 10 toward the conveying roller 12. The conveying roller 12 conveys the sheet S from the pickup roller 11 toward the photosensitive drum 4.
The photosensitive drum 4 can rotate about an axis A. The axis A extends in a first direction. The photosensitive drum 4 has a cylindrical shape. The photosensitive drum 4 extends along axis A.
The charging device 5 electrically charges a surface of the photosensitive drum 4. The charging device 5 is, specifically, a charging roller. Note that, the charging device 5 may also be a scorotron-type charger. In a case where the charging device 5 is a charging roller, the charging device 5 is in contact with the surface of the photosensitive drum 4. In a case where the charging device 5 is a scorotron-type charging device, the charging device 5 is located at an interval from the surface of the photosensitive drum 4.
The exposure device 6 exposes the surface of the photosensitive drum 4. Specifically, the exposure device 6 exposes the surface of the photosensitive drum 4 electrically charged by the charging device 5. Thereby, an electrostatic latent image is formed on the surface of the photosensitive drum 4. The exposure device 6 is, specifically, a laser scan unit. Note that, the exposure device 6 may also be an LED array.
The developing device 7 supplies toner to the surface of the photosensitive drum 4. Thereby, the electrostatic latent image is developed, so that a toner image is formed on the surface of the photosensitive drum 4. The developing device 7 includes a toner accommodation unit 13 and a developing roller 14.
The toner accommodation unit 13 accommodates toner. Toner contains toner particles, and as required, an external additive. The toner particles contain a binding resin, and as required, a colorant, a pigment dispersant, a mold release agent, a magnetic material and a charge control agent. The binding resin is a base of the toner particles. The binding resin binds the components contained in the toner particles. The colorant imparts a desired color to the toner particles. The colorant is dispersed in the binding resin. The pigment dispersant improves dispersibility of the colorant. The charge control agent gives chargeability to the toner particles. The chargeability may be any of positive chargeability and negative chargeability. The external additive regulates chargeability, flowability and storage stability of the toner particles.
The developing roller 14 supplies toner in the toner accommodation unit 13 to the surface of the photosensitive drum 4. The developing roller 14 is in contact with the photosensitive drum 4. Note that, the developing roller 14 may not be in contact with the photosensitive drum 4.
The developing device 7 may be constituted as one process unit, together with the photosensitive drum 4 and the charging device 5. The process unit can be mounted to the main body housing 2.
In addition, the developing device 7 may be a developing cartridge that can be mounted to a drum unit having the photosensitive drum 4 and the charging device 5. The drum unit can be mounted to the main body housing 2.
The developing device 7 may also have a developing unit having the developing roller 14, and a toner cartridge that can be mounted to the developing unit. In this case, the toner cartridge has the toner accommodation unit 13. In addition, the developing unit may be provided to the drum unit. The developing unit can be mounted to the drum unit.
The transfer device 8 transfers the toner image from the photosensitive drum 4 to the sheet S. Thereby, the toner image is formed on the sheet S. The transfer device 8 is in contact with the photosensitive drum 4. Note that, the transfer device 8 may not be in contact with the photosensitive drum 4. The transfer device 8 is, specifically, a transfer roller. Note that, the transfer device 8 may also be a transfer belt.
The fixing device 9 provides a fixing solution to the toner image to fix the toner image on the sheet S. Specifically, the fixing device 9 sprays the fixing solution toward the toner image on the sheet S by electrostatic spraying, thereby providing the fixing solution to the toner image. Then, the binding resin of the toner is softened by the fixing solution. Thereafter, the softened binding resin is cured, so that the toner is fixed on the sheet S. Thereby, the toner image is fixed on the sheet S. The sheet S on which the toner image is fixed is discharged outside the main body housing 2.
Subsequently, details of the fixing device 9 are described with reference to
As shown in
The nozzle unit 9A sprays the fixing solution to a sheet S on which a toner image is formed. As shown in
The housing 21 can accommodate the fixing solution. The housing 21 extends in the first direction. The first direction is a direction in which the axis A of the photosensitive drum 4 extends. The first direction is also a width direction of the sheet S. The housing 21 has an outer surface S1 and an outer surface S2 in a second direction. The second direction is a direction facing from the opposite electrode 9B (refer to
The nozzle electrode 21A is electrically connected to a power supply P1 (refer to
The plurality of nozzle 22 is located on the outer surface S2 of the housing 21. The plurality of nozzles 22 is located between the nozzle electrode 21A the opposite electrode 9B (refer to
As shown in
The first flat plate 31 extends in the first direction and in the second direction. The first flat plate 31 has an edge E1 and an edge E2 in the second direction. The edge E2 is located distant from the edge E1 in the second direction. The edge E2 is located closer to the nozzle unit 9A (refer to
As shown in
A length of each of the plurality of first projections 32 in the second direction is, for example, 1 mm or greater, preferably 2 mm or greater. The length of each of the plurality of first projections 32 in the second direction is, for example, 10 mm or less.
As shown in
As shown in
As shown in
The second flat plate 33 extends in the first direction and in the second direction. The second flat plate 33 has an edge E11 and an edge E12 in the second direction. The edge E12 is located distant from the edge E11 in the second direction. The edge E12 is located closer to the nozzle unit 9A (refer to
Each of the plurality of second projections 34 extends from the edge E12 of the second flat plate 33 toward the nozzle unit 9A in the second direction. Each of the plurality of second projections 34 has the same shape as each of the plurality of first projections 32. Thereby, each of the plurality of second projections 34 has the same function as each of the plurality of first projections 32. The plurality of second projections 34 are aligned at intervals in the first direction.
Each of the plurality of connection plates 35 extends in the first direction and in the third direction. One end portion of each of the plurality of connection plates 35 in the third direction is connected to the edge E1 of the first flat plate 31. In addition, the other end portion of each of the plurality of connection plates 35 in the third direction is connected to the edge E11 of the second flat plate 33. Each of the plurality of connection plates 35 is provided to electrically connect the first flat plate 31 and the second flat plate 33 each other. Thereby, in the state where the voltage is applied to the opposite electrode 9B, a voltage of the first flat plate and a voltage of the second flat plate are the same. The plurality connection plates 35 are aligned at intervals in the first direction.
The connection terminal 36 is located at one end portion of the opposite electrode 9B in the first direction. Specifically, the connection terminal 36 extends from the edge E3 of the first flat plate 31. The connection terminal 36 is electrically connected to a power supply P2 (refer to
Specifically, as shown in
The frame 9C has an accommodation unit 90. The accommodation unit 90 can accommodate the fixing solution sprayed from the nozzle unit 9A. The accommodation unit 90 has a bottom wall 91 and a sidewall 92. The bottom wall 91 is located on an opposite side to the nozzle unit 9A with respect to the opposite electrode 9B in the second direction. The sidewall 92 extends from the bottom wall 91 in the second direction. The opposite electrode 9B is attached to the bottom wall 91.
The electrode 9D is attached to the sidewall 92. The electrode 9D is electrically connected to the power supply P2 (refer to
According to the fixing device 9, as shown in
In the state where the voltage is applied to the opposite electrode 9B, the electrostatic force is concentrated on the tip end 321 of each of the plurality of first projections 32.
For this reason, it is possible to form the strong electric field at the tip end 321 of each of the plurality of first projections 32 without increasing the voltage that is applied to the opposite electrode 9B.
The plurality of first projections 32 are aligned in the first direction.
For this reason, it is possible to stably attract the fixing solution sprayed from each of the plurality of nozzles 22 toward the opposite electrode 9B by the strong electric field formed in the first direction.
As a result, even in a case where the sheet S is electrically charged, it is possible to stably provide the fixing solution sprayed from each of the plurality of nozzles 22 to the sheet S.
In addition, according to the fixing device 9, as shown in
Thereby, the electrostatic force can be further concentrated on the tip end 321 of each of the plurality of first projections 32.
Further, according to the fixing device 9, as shown in
Thereby, in the state where the voltage is applied to the opposite electrode 9B, the voltage of the first flat plate 31 and the voltage of the second flat plate 33 are the same.
As a result, it is possible to form the electric field of the uniform intensity by the plurality of first projections 32 and the plurality of second projections 34.
In addition, according to the fixing device 9, as shown in
For this reason, in the state where the voltage is applied to the opposite electrode 9B, the fixing solution sprayed from each of the plurality of nozzles 22 is more attracted to the tip end 321 of each of the plurality of first projections 32 than the connection terminal 36.
In addition, according to the fixing device 9, as shown in
Thereby, the fixing solution sprayed from the plurality of nozzles 22 can be securely attracted toward the opposite electrode 9B.
Modified examples are described with reference to
(1) As shown in
(2) As shown in
(3) As shown in
Specifically, the electrode 9D extends in the third direction. The third direction is a direction in which the sheet S passes between the nozzle unit 9A and the opposite electrode 9B. The third direction intersects with both the first direction and the second direction. The third direction is preferably orthogonal to both the first direction and the second direction. The electrode 9D has a first terminal T1 and a second terminal T2.
The first terminal T1 is located inside the accommodation unit 90. The first terminal T1 is electrically connected to the opposite electrode 9B inside the accommodation unit 90. The first terminal T1 is in contact with a central portion of the opposite electrode 9B in the first direction. The first terminal T1 is in contact with the connection plate 35 of the opposite electrode 9B. In a state where the first terminal T1 is in contact with the connection plate 35 of the opposite electrode 9B, the first terminal T1 is located more distant from the nozzle unit 9A than the tip end 321 of each of the plurality of first projections 32 in the second direction. In other words, in the state where the first terminal T1 is in contact with the connection plate 35 of the opposite electrode 9B, the tip end 321 of each of the plurality of first projections 32 is located between the nozzle unit 9A and the first terminal T1 in the second direction. Note that, in this modified example, as shown in
The second terminal T2 is located outside the accommodation unit 90. The second terminal T2 is located distant from the first terminal T1. The second terminal T2 is electrically connected to the power supply P2 of the image forming apparatus 1 outside the accommodation unit 90.
In this modified example, as shown in
For this reason, it is possible to suppress the mists of the fixing solution sprayed from the nozzle unit 9A from being attracted to the sidewall 92.
As a result, the nozzle unit 9A can stably spray the fixing solution toward the opposite electrode 9B.
Number | Date | Country | Kind |
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2019-063971 | Mar 2019 | JP | national |
2019-219837 | Dec 2019 | JP | national |
This is a continuation application of International Application No. PCT/JP2019/051139 filed on Dec. 26, 2019 which claims the benefit of priority from Japanese patent applications No. 2019-063971 filed on Mar. 28, 2019 and No. 2019-219837 filed on Dec. 4, 2019. The entire contents of the earlier applications are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/JP2019/051139 | Dec 2019 | US |
Child | 17487121 | US |