JP5983272B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a fixing device, a conveying member, and an image forming apparatus.

  2. Description of the Related Art A fixing device is known that irradiates a recording medium on which a toner image is formed with laser light to fix the toner on the recording medium. Japanese Patent Application Laid-Open No. 2004-228561 describes a technique for suppressing damage to the conveyor belt by irradiating the laser beam by using a conveyor belt having a property of transmitting laser light. Patent Document 2 describes that a toner is uniformly fixed to an image recording medium by providing a light absorption layer for converting laser light into heat on the surface of the image recording medium. Patent Document 2 also describes that a toner image fixed on an image recording medium is removed by bringing a removal roller heated by irradiation with laser light into contact with the image recording medium.

JP 2011-107658 A JP 2010-243596 A

  An object of the present invention is to suppress heating of a conveying member irradiated with light from an irradiation unit in a fixing device.

Fixing device according to claim 1, an irradiation unit for irradiating a laser beam on a recording medium on which an image by the image forming material is fixed by absorbing light is formed, is dispersed in the base material is a resin the substrate A first layer that includes the base material and a dispersion material having a different refractive index and is irradiated with the light , and is formed on a side opposite to the irradiation unit with respect to the first layer , and reflects the laser light A transporting member that transports the recording medium, the transporting member having a second layer, and having a reflectance of the light irradiated by the irradiation unit equal to or higher than the recording medium.

Fixing device according to claim 2, an irradiation unit for irradiating a laser beam on a recording medium on which an image by the image forming material is fixed by absorbing light is formed, is dispersed in the base material is a resin the substrate A first layer that includes the base material and a dispersion material having a different refractive index and is irradiated with the light , and is formed on a side opposite to the irradiation unit with respect to the first layer , and reflects the laser light It has a 2nd layer and is a conveyance member which conveys the said recording medium, Comprising: It has a conveyance member whose reflectance of the light irradiated by the said irradiation part is high compared with the layer containing only the said base material.

  According to a third aspect of the present invention, in the fixing device according to the first or second aspect, the refractive index of the dispersion material is different from the refractive index of the base material.

  According to a fourth aspect of the present invention, in the fixing device according to any one of the first to third aspects, the electrical conductivity of the dispersion material is higher than the electrical conductivity of the base material. .

  According to a fifth aspect of the present invention, in the fixing device according to the third or fourth aspect, the dispersion material is titanium oxide.

According to a sixth aspect of the present invention, in the fixing device according to any one of the first to fifth aspects, the transport member is a belt that supports the recording medium.

A fixing device according to a seventh aspect of the present invention is the fixing device according to any one of the first to sixth aspects, wherein the first layer is white.

The conveying member according to claim 8 , wherein the second layer is made of any one of aluminum, copper, iron, nickel, zinc, tin, chromium, gold, and silver, or two or more of these metals It is an alloy .

An image forming apparatus according to claim 9 irradiates a laser beam to a transfer unit that transfers an image of an image forming material that is fixed by absorbing light onto a recording medium, and a recording medium on which the image is transferred by the transfer unit. A first layer that is irradiated with the light, and includes a base material that is a resin and a dispersion material that is dispersed in the base material and has a refractive index different from that of the base material , and the first layer. A transport member for transporting the recording medium, the second layer reflecting the laser light, and having a reflectance of the light irradiated by the irradiation unit. And a conveying member that is larger than the recording medium.

An image forming apparatus according to claim 10 irradiates a laser beam onto a transfer unit that transfers an image formed of an image forming material that is fixed by absorbing light onto a recording medium, and a recording medium on which the image is transferred by the transfer unit. A first layer that is irradiated with the light, and includes a base material that is a resin and a dispersion material that is dispersed in the base material and has a refractive index different from that of the base material , and the first layer. A transport member for transporting the recording medium, the second layer reflecting the laser light, and having a reflectance of the light irradiated by the irradiation unit. It has a high conveyance member compared with the layer containing only a base material.

According to the first and ninth aspects of the invention, the conveying member irradiated with light by the irradiating unit is heated as compared with the case where the light reflectance of the conveying member is lower than the light reflectance of the recording medium. can be suppressed, further light irradiated by the irradiation portion Ru can be prevented from being transmitted through the conveying member.
According to the invention which concerns on Claim 2 and 10 , compared with the case where the reflectance of the light of a conveyance member is lower than the reflectance of the light of the layer containing only a base material, the conveyance member irradiated with light by the irradiation part is can be suppressed from being heated, further light irradiated by the irradiation portion Ru can be prevented from being transmitted through the conveying member.
According to the invention which concerns on Claim 3, compared with the case where the refractive index of a dispersion material is the same as the refractive index of a base material, it can suppress that the conveyance member irradiated with light is heated.
According to the invention which concerns on Claim 4, compared with the case where the electrical conductivity of a dispersing material is low compared with the electrical conductivity of a base material, it can make it easy to charge a conveyance member.
According to the invention which concerns on Claim 5, compared with the case where a dispersion material is not a titanium oxide, it can suppress that the conveyance member irradiated with light by the irradiation part is heated.
According to the invention which concerns on Claim 6 , compared with the case where a 1st layer does not contain a dispersing material, it can suppress that the belt irradiated with light by the irradiation part is heated.
According to the invention which concerns on Claim 7 , it can suppress that the conveyance member irradiated with light by the irradiation part is heated compared with the case where a 1st layer is not white.

Schematic showing the internal configuration of the image forming apparatus Cross-sectional schematic view of the fixing device as seen from the upstream side in the transport direction Cross-sectional schematic view of the fixing device viewed from one side in the width direction Cross section of conveyor belt

  FIG. 1 is a diagram showing an outline of an internal configuration of an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 is an apparatus that functions as a copying machine, a printer, a scanner, a facsimile, or the like. The image forming apparatus 1 includes a housing unit 10, a supply roller 20, a conveyance roller 30, a transfer unit 40, a fixing device 50, and a discharge roller 60 in a housing 100. The storage unit 10 stores paper p (an example of a recording medium). The supply roller 20 comes into contact with one of the sheets p stored in the storage unit 10 and supplies the sheet p along the transport path r (chain line). The transport roller 30 is a cylindrical member, rotates around the center of the cylinder, and transports the paper p supplied by the supply roller 20. The sheet p is transported by the transport roller 30 and passes through the transfer unit 40. The transfer unit 40 transfers a toner image (an example of an image) to the paper p conveyed by the conveyance roller 30. The fixing device 50 heats and fixes the toner image transferred by the transfer unit 40 onto the paper p by irradiating light. The discharge roller 60 discharges the paper p on which the toner image is fixed from the image forming apparatus 1.

  The transfer unit 40 includes a photosensitive drum 401, a charger 402, an exposure device 403, a developing device 404, a toner cartridge 405, an intermediate transfer belt 406, a rotation roller 407, a primary transfer roller 408, a secondary transfer roller 409, and a backup roller 410. Have The photosensitive drum 401 is a cylindrical member having a photoconductive film laminated on the outer peripheral surface, and is supported so as to rotate about the center of the cylinder. The photosensitive drum 401 is disposed so as to be in contact with the intermediate transfer belt 406, and rotates in the direction of arrow A1 in the drawing as the intermediate transfer belt 406 moves. The charger 402 is, for example, a scorotron charger, and charges the photoconductive film of the photosensitive drum 401 to a predetermined potential. The exposure device 403 exposes the photosensitive drum 401 charged by the charger 402 to form an electrostatic latent image. The developing device 404 contains a two-component developer containing toner of any color of Y (Yellow), M (Magenta), C (Cyan), and K (Black) and a magnetic carrier such as ferrite powder. . The developing device 404 forms a toner image by attaching toner to the electrostatic latent image formed on the photosensitive drum 401. The developing device 404 is connected to the toner cartridge 405 via a toner replenishment path, and receives toner replenishment from the toner cartridge 405 by a rotational drive of a dispense motor (not shown). The intermediate transfer belt 406 is an endless belt-like member and rotates in the direction of an arrow A2 in the drawing. The rotation roller 407 is a cylindrical member that supports the movement of the intermediate transfer belt 406 and rotates about the center of the cylinder. The primary transfer roller 408 is a cylindrical member that faces the photosensitive drum 401 with the intermediate transfer belt 406 interposed therebetween. The primary transfer roller 408 is applied with a transfer bias from a power source (not shown), generates a potential difference with the photosensitive drum 401, and transfers the toner image on the surface of the photosensitive drum 401 to the surface of the intermediate transfer belt 406. . The secondary transfer roller 409 is a cylindrical member that faces the backup roller 410 with the intermediate transfer belt 406 interposed therebetween. The secondary transfer roller 409 is applied with a transfer bias from a power source (not shown), generates a potential difference with the backup roller 410, and transfers the toner image on the surface of the intermediate transfer belt 406 to the paper p.

  The image forming apparatus 1 also includes a control unit, a communication unit, and a storage unit (not shown). The control unit controls the operation of each unit of the image forming apparatus 1 described above. The control unit includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The communication unit is connected to an external device such as a personal computer or a facsimile, and transmits / receives image data. The storage unit includes a device that stores data and programs used by the control unit, such as an HDD (Hard Disk Drive). With the above configuration, the image forming apparatus 1 forms and fixes a toner image on the paper p in the process of transporting the paper p along the transport path r. Hereinafter, the direction in which the paper p is transported is simply referred to as “transport direction”, and the direction orthogonal to the transport direction is referred to as “width direction”.

  FIG. 2 is a schematic cross-sectional view of the fixing device 50 according to the embodiment of the present invention as viewed from the upstream side in the transport direction. FIG. 3 is a schematic cross-sectional view of the fixing device 50 as viewed from one side in the width direction. The x axis represents the width direction, the y axis represents the transport direction, and the z axis represents the height direction. The fixing device 50 includes an irradiation unit 101, an optical member 102, a reflection member 103, a partition member 104, and a conveyance belt 105.

  The irradiation unit 101 irradiates the paper p conveyed by the conveyance roller 30 with the laser beam LB. The irradiation unit 101 includes a plurality of light sources 1011 that generate laser light LB. The optical axis a1 is the optical axis of the laser beam LB. As illustrated in FIG. 2, the light sources 1011 are arranged at intervals g along the width direction. The interval g is determined so that the laser beam LB is irradiated on the entire area of the paper p where the toner image can be formed. In FIG. 2, the irradiation unit 101 includes four light sources 1011. The wavelength of the laser beam LB may be any wavelength as long as energy sufficient to melt the toner can be given to the toner. For example, infrared light is used as the laser light LB. In this case, the developing device 404 uses toner mixed with a material that absorbs infrared rays.

  The optical member 102 is a member that controls the direction in which the laser beam LB emitted from the light source 1011 propagates, for example, a lens. One optical member 102 is provided for each light source 1011. In FIG. 2, four optical members 102 are provided corresponding to each of the four light sources 1011 arranged in the width direction. The laser beam LB emitted from the light source 1011 propagates toward the optical member 102. As shown in FIG. 3, the optical member 102 has a convex cross section viewed from the width direction and converges the laser beam LB in the transport direction. The optical member 102 converges the laser beam LB so that the irradiation width in the transport direction falls within a predetermined range (for example, 1.0 ± 0.1 mm). Further, as shown in FIG. 2, the optical member 102 has a rectangular cross section viewed from the conveyance direction, and transmits the laser light LB without being refracted in the width direction. When the laser beam LB passes through the optical member 102, it propagates toward the reflecting member 103.

  As shown in FIG. 2, the reflecting member 103 has a rectangular cross section viewed from the conveying direction, and the cross section viewed from the width direction has an arch shape as shown in FIG. The reflective member 103 has a hole 1031, an opening 1032, and a reflective surface 1033. The hole 1031 allows the laser beam LB emitted from the light source 1011 to pass inside the reflecting member 103. The opening 1032 faces the conveyance path r and allows the laser beam LB propagated inside the reflecting member 103 to pass therethrough. The laser beam LB that has passed through the opening 1032 is irradiated onto an irradiation region D1 that extends in the width direction on the transport path r. In the example shown in FIG. 3, the angle θ formed by the optical axis a <b> 1 and the transport path r when viewed from the width direction is 90 degrees. When the paper p is irradiated with the laser beam LB, the laser beam LB is reflected in a region where the toner particles on the surface of the paper p are not attached. Since specular reflection and diffuse reflection occur on the surface of the paper p, the laser beam LB is reflected in all directions. The opening 1032 also allows the reflected light reflected by the surface of the paper p to pass through. The reflective surface 1033 is a surface that is inside the reflective member 103 and faces the conveyance path r. The reflection surface 1033 reflects the reflected light that has passed through the opening 1032 to the paper p. The reflecting surface 1033 is processed to reflect the laser beam LB. For example, the reflecting member 103 may be made of a metal such as aluminum, and the reflecting surface 1033 may be polished to a mirror surface, or the reflecting surface 1033 may be plated with silver or the like. The reflected light is reflected by the reflecting surface 1033, so that a part of the reflected light is absorbed by the toner particles and the rest is reflected again by the surface of the paper p. As described above, when the reflection of the laser beam LB is repeated between the surface of the paper p and the reflection surface 1033 of the reflection member 103, a part of the laser beam LB reflected by the reflection surface 1033 is absorbed by the toner and the toner is heated. And melting is promoted.

  Part of the heated toner is sublimated into a gas by the laser beam LB, and this may be cooled to generate dust. The partition member 104 partitions the irradiation unit 101 and the conveyance path r so that dust does not enter the space surrounded by the reflection member 103. The partition member 104 is a rectangular and plate-shaped member having a short side and a long side, and is formed of a material that transmits light, for example, quartz glass. The partition member 104 is supported by the reflecting member 103 at the opening 1032 so that the short side is along the transport direction and the long side is along the width direction.

  The conveyance belt 105 (an example of a conveyance member) conveys the paper p along the conveyance path r. The conveyor belt 105 is driven by a pair of drive rollers 106 that rotate in the direction indicated by arrow A3. The driving roller 106a is a roller on the downstream side of the conveyance path r, and the driving roller 106b is a roller on the upstream side of the conveyance path r. The driving roller 106a is rotationally driven by a power source (not shown), and the driving roller 106b rotates with the rotation of the driving roller 106a. When the driving roller 106 rotates in the direction indicated by the arrow A3, the conveyance belt 105 rotates in the direction indicated by the arrow A4. The conveyor belt 105 also reflects the laser beam LB irradiated by the irradiation unit 101. The reflectance of the laser beam LB by the conveying belt 105 is equal to or higher than the reflectance of the laser beam LB by the paper p. The “reflectance” here refers to a reflectance that combines specular reflection and diffuse reflection.

  FIG. 4 is a cross-sectional view of the transport belt 105 in the yz plane. The conveyor belt 105 includes a base material layer 1051 and a metal layer 1052. The base material layer 1051 (an example of a first layer) is a layer facing the opening 1032, and is irradiated with the laser light LB irradiated by the irradiation unit 101. The base material layer 1051 includes a base material 1051a and a dispersion material 1051b. The base material 1051a is a main substance of the base material layer 1051. For the base material 1051a, a material having heat resistance and flexibility, for example, a resin such as a polyimide resin, a polyamide resin, or a polyamideimide resin is used. The dispersion material 1051b is a substance that is dispersed in the base material 1051a. The dispersion material 1051b is used to increase the reflectance of light on the transport belt 105 compared to the case where the dispersion material 1051b is not used. Further, in this example, since the conveyance belt 105 conveys the recording medium by electrification and adsorption, the dispersion material 1051b is used to make the electric conductivity of the conveyance belt 105 higher than when the dispersion material 1051b is not used. That is, as the dispersion material 1051b, a material having a refractive index different from that of the base material 1051a and high electrical conductivity is used. Specifically, for example, titanium oxide is used as the base material 1051a. The base material layer 1051 in which titanium oxide is used for the dispersion material 1051b is white.

  The metal layer 1052 (an example of the second layer) is a layer that is in contact with the driving roller 106 and reflects the laser beam LB that is transmitted without being reflected by the base material layer 1051. For the metal layer 1052, for example, aluminum is used.

(Modification)
The present invention is not limited to the above-described embodiments, and various modifications can be made. Hereinafter, some modifications will be described. Two or more of the modifications described below may be used in combination.

(1) Modification 1
The dispersion material 1051b is not limited to titanium oxide. For the dispersion material 1051b, for example, a white pigment such as calcium carbonate or barium sulfate may be used. In another example, an oxide semiconductor such as indium oxide, tin dioxide, or zinc oxide may be used for the dispersion material 1051b. In any of the above examples, a plurality of substances may be used together as the dispersing material 1051b. In yet another example, the dispersion material 1051b is not necessarily a material having a higher electrical conductivity than the base material 1051a as long as the material has a refractive index different from that of the base material 1051a.

(2) Modification 2
The metal used for the metal layer 1052 is not limited to aluminum. For the metal layer 1052, for example, copper, iron, nickel, zinc, tin, chromium, gold, silver, or an alloy of two or more of these metals may be used.
In the above-described embodiment, the metal layer 1052 is shown as an example of the second layer. However, the second layer is not limited to the metal layer 1052. For example, the second layer may be a layer in which carbon black, carbon nanotube, graphite, or the like is dispersed in a resin such as a polyimide resin, a polyamide resin, or a polyamideimide resin. In this case, the second layer absorbs the laser beam LB transmitted without being reflected by the base material layer 1051.

(3) Modification 3
The conveyance belt 105 is not limited to the case of two layers of the base material layer 1051 and the metal layer 1052. The conveyance belt 105 may be a single layer including only the base material layer 1051. In another example, the conveyance belt 105 may have three or more layers. For example, an elastic layer made of an elastic material such as silicone rubber may be provided as a layer that supports the metal layer 1052.

(4) Modification 4
The conveying member is not limited to the conveying belt 105. The transport member may be, for example, a roller that includes the base material layer 1051 and the metal layer 1052 and transports the paper p.

(5) Modification 5
The optical member 102 is not limited to the one that converges the laser beam LB in the transport direction. For example, the optical member 102 may diffuse the laser beam LB in the width direction. In this case, a lens having a concave section viewed from the transport direction is used as the optical member 102. In another example, a lens that diffuses the laser light LB in the width direction and a lens that converges the laser light LB in the transport direction may be provided for one light source 1011. In still another example, a single optical member extending along the width direction may be provided in correspondence with the plurality of light sources 1011 arranged along the width direction.

(6) Modification 6
When viewed from the width direction, the angle θ formed by the optical axis a1 with the transport path r is not limited to 90 degrees. The angle θ may be a value smaller than 90 degrees.

(7) Modification 7
The light irradiated by the irradiation unit 101 is not limited to the laser beam LB. For example, the irradiation unit 101 may irradiate the paper p with light generated by a flash lamp such as a xenon lamp.

(8) Other Modifications The number of light sources 1011 is not limited to one in the transport direction. A plurality of light sources 1011 may be arranged in the transport direction.
In the embodiment, toner is shown as an example of the image forming material, but the image forming material may be ink. In this case, the ink is irradiated with light and dried, whereby the image is fixed on the paper p.
In the embodiment, the image forming apparatus 1 forms a color image. However, a monochrome image may be formed.
In the embodiment, an example is shown in which the paper p is cut into one page at a predetermined size. However, the paper p is a continuous paper that is not cut into one page (also referred to as continuous form or continuous paper). It may be.

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Accommodating part, 20 ... Supply roller, 30 ... Conveyance roller, 40 ... Transfer part, 401 ... Photosensitive drum, 402 ... Charger, 403 ... Exposure apparatus, 404 ... Developing apparatus, 405 ... Toner Cartridge, 406 ... Intermediate transfer belt, 407 ... Rotating roller, 408 ... Primary transfer roller, 409 ... Secondary transfer roller, 410 ... Backup roller, 50 ... Fixing device, 60 ... Ejecting roll, 100 ... Housing, 101 ... Irradiation unit DESCRIPTION OF SYMBOLS 1011 ... Light source, 102 ... Optical member, 103 ... Reflective member, 1031 ... Hole, 1032 ... Opening part, 1033 ... Reflecting surface, 104 ... Partition member, 105 ... Conveying belt, 1051 ... Base material layer, 1052 ... Metal layer

Claims (10)

An irradiation unit that irradiates a recording medium on which an image formed of an image forming material that absorbs and fixes light is formed with laser light;
A first layer that is dispersed in the base material that is a resin and a dispersion material that has a refractive index different from that of the base material and is irradiated with the light ; and the irradiation unit with respect to the first layer; A conveying member that is formed on the opposite side and has a second layer that reflects the laser light and conveys the recording medium, and has a reflectance of the light irradiated by the irradiation unit that is greater than or equal to the recording medium A fixing device having a conveying member. An irradiation unit that irradiates a recording medium on which an image formed of an image forming material that absorbs and fixes light is formed with laser light;
A first layer that is dispersed in the base material that is a resin and a dispersion material that has a refractive index different from that of the base material and is irradiated with the light ; and the irradiation unit with respect to the first layer; A conveying member that is formed on the opposite side and has a second layer that reflects the laser light and conveys the recording medium, and the reflectance of the light irradiated by the irradiation unit includes only the base material A fixing device having a conveying member higher than a layer. The fixing device according to claim 1, wherein a refractive index of the dispersion material is different from a refractive index of the base material. The fixing device according to claim 1, wherein the electrical conductivity of the dispersion material is higher than the electrical conductivity of the base material. The fixing device according to claim 3, wherein the dispersion material is titanium oxide. The conveying member, the fixing device according to any one of claims 1 to 5, characterized in that a belt for supporting the recording medium. Said first layer, the fixing device according to any one of claims 1 to 6, characterized in that it is white. The second layer is a metal selected from aluminum, copper, iron, nickel, zinc, tin, chromium, gold, and silver, or an alloy of two or more of these metals.
The fixing device according to claim 1, wherein A transfer portion that transfers an image formed by an image forming material that absorbs light and is fixed to a recording medium;
An irradiation unit that irradiates a recording medium onto which the image has been transferred by the transfer unit with a laser beam;
A first layer that is dispersed in the base material that is a resin and a dispersion material that has a refractive index different from that of the base material and is irradiated with the light ; and the irradiation unit with respect to the first layer; A conveying member that is formed on the opposite side and has a second layer that reflects the laser light and conveys the recording medium, and has a reflectance of the light irradiated by the irradiation unit that is greater than or equal to the recording medium An image forming apparatus having a conveying member. A transfer portion that transfers an image formed by an image forming material that absorbs light and is fixed to a recording medium;
An irradiation unit that irradiates a recording medium onto which the image has been transferred by the transfer unit with a laser beam;
A first layer that is dispersed in the base material that is a resin and a dispersion material that has a refractive index different from that of the base material and is irradiated with the light ; and the irradiation unit with respect to the first layer; A conveying member that is formed on the opposite side and has a second layer that reflects the laser light and conveys the recording medium, and the reflectance of the light irradiated by the irradiation unit includes only the base material An image forming apparatus having a conveying member higher than a layer.

Images