JP2018146741A - Fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deterioration of the fixability of a developer image, in a configuration where a light source and a condensing member rotated in contact with a belt are arranged inside the belt whose inner peripheral surface has the adhesion of a liquid in comparison with a configuration not having a leveling member leveling the liquid adhered to the condensing member.SOLUTION: A fixing device 20 includes a belt 22, a light source unit 24, a nip forming roll 26, and a leveling member 28. The belt 22 is endless and transparent. A silicone oil OL is adhered to the inner peripheral surface 22A of the belt 22. The belt 22 comes into contact with a toner image G on a paper sheet P. The light source unit 24 is arranged inside the belt 22 and emits laser light Bm. The nip forming roll 26 is rotatably provided inside the belt 22, has a contact part 29 which comes into contact with a part of the inner peripheral surface 22A of the belt 22, and condenses the laser light Bm emitted from the light source unit 24 toward the contact part 29. The leveling member 28 levels the silicone oil OL adhered to the nip forming roll 26.SELECTED DRAWING: Figure 2

Description

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

  The fixing device of Patent Document 1 includes a transparent cylinder, a counter member that cooperates with the transparent cylinder, a laser light irradiation device that irradiates the transparent cylinder with laser light, a condensing member that condenses the laser light, A liquid filling body is provided between the transparent cylinder and the condensing member. The liquid filling body is filled with a transparent liquid that can transmit laser light.

Japanese Patent Laying-Open No. 2015-72351

  There is a configuration in which a light source and a condensing member that rotates while being in contact with the belt are arranged on the inner side of the belt with liquid adhered to the inner peripheral surface. In this configuration, the liquid adhering to the inner peripheral surface of the belt is transferred to the light collecting member at the contact portion between the light collecting member and the belt. Here, since the amount of the liquid transferred to the light collecting member is not managed, the amount of the liquid existing at the light incident portion of the light collecting member varies with the rotation of the light collecting member. The scattering state of the light incident on the light collecting member from the light source is changed by changing the amount of the liquid. If the light scattering state changes, the fixability of the developer image may deteriorate.

  The present invention has a leveling member that smoothes the liquid adhering to the light condensing member in a configuration in which the light source and the light condensing member that rotates while contacting the belt are arranged inside the belt with liquid adhering to the inner peripheral surface. The object is to suppress the deterioration of the fixability of the developer image as compared with a configuration in which the developer image is not made.

  According to a first aspect of the present invention, there is provided a fixing device that is endless and transparent, has a liquid attached to an inner peripheral surface thereof, and an outer peripheral surface that contacts a developer image on a recording medium, and is disposed inside the belt. A light irradiating means for irradiating light, and a contact portion that is rotatably provided inside the belt and contacts a part of the inner peripheral surface in a range of contact with the recording medium of the belt. A light collecting member that collects the light emitted from the means toward the contact portion; and a leveling member that smoothes the liquid adhering to the light collecting member.

  The leveling member of the fixing device according to claim 2 of the present invention is downstream of the contact portion in the rotation direction of the light collecting member and upstream of the light incident portion on the light collecting member. Has been placed.

  The leveling member of the fixing device according to claim 3 of the present invention is disposed so as to face the outer peripheral surface of the light collecting member along the axial direction of the light collecting member, and is attached to the outer peripheral surface of the light collecting member. Consists of plate material that reduces the amount of

  The leveling member of the fixing device according to a fourth aspect of the present invention includes a replenishing member that is impregnated with a liquid and replenishes the outer peripheral surface of the light collecting member.

  The light irradiating means of the fixing device according to claim 5 of the present invention has a plurality of light source portions arranged at set intervals set along the axial direction of the light collecting member, and the leveling member is the light collecting member. The shape of the part facing the outer peripheral surface of the light condensing member in the leveling member is arranged opposite to the outer peripheral surface of the light collecting member along the axial direction of the optical member. When viewed from the tangential direction of the light collecting member orthogonal to the direction in which the light sources are arranged, the wave shape has a period equal to or shorter than the set interval.

  According to a sixth aspect of the present invention, there is provided an image forming apparatus for forming a developer image on a recording medium, and fixing the developer image on the recording medium formed by the forming means to the recording medium. To the fixing device according to claim 5.

  According to the first aspect of the present invention, in the configuration in which the light source and the condensing member that rotates while contacting the belt are arranged inside the belt having the liquid adhered to the inner peripheral surface, the liquid adhering to the light condensing member is leveled. Compared to a configuration that does not have a member, it is possible to suppress the deterioration of fixability of the developer image.

  The invention according to claim 2 can suppress the deterioration of the fixability of the developer image as compared with the configuration in which the leveling member is disposed upstream of the contact portion and downstream of the light incident portion. .

  The invention of claim 3 can suppress the amount of the liquid from becoming excessive at the light incident portion of the light condensing member, as compared with the configuration in which the amount of the liquid is equalized without decreasing.

  The invention according to claim 4 can suppress the amount of liquid adhering to the outer peripheral surface of the light collecting member from varying in the axial direction as compared with the configuration in which the leveling member does not have the replenishing member.

  The invention according to claim 5 diffuses light in the rotation axis direction of the light collecting member when the shape of the portion facing the outer peripheral surface of the leveling member is viewed from the tangential direction of the light collecting member, compared to a linear configuration. Can be made.

  According to the sixth aspect of the present invention, image defects after fixing can be suppressed as compared with the configuration having no fixing device according to any one of the first to fifth aspects.

1 is an overall configuration diagram schematically illustrating an image forming apparatus according to a first embodiment. 1 is a configuration diagram illustrating a fixing device according to a first embodiment. It is explanatory drawing which shows the state which made the leveling member contact the nip formation roll which concerns on 1st Embodiment. (A) It is explanatory drawing which shows the state which the laser beam which injected into the belt and nip formation roll which concerns on 1st Embodiment is condensed, (B) Belt and nip formation from the several light source part which concerns on 1st Embodiment It is explanatory drawing which shows the state in which a laser beam injects into a roll. It is explanatory drawing which shows the state which made the leveling member contact the nip formation roll which concerns on 2nd Embodiment. (A) It is explanatory drawing which shows the state which the laser beam which injected into the belt and nip formation roll which concerns on 2nd Embodiment is condensed, (B) Belt and nip formation from the several light source part which concerns on 2nd Embodiment It is explanatory drawing which shows the state in which a laser beam injects into a roll. It is explanatory drawing which shows the state which made the blade and the web contact the nip forming roll which concerns on 3rd Embodiment. It is explanatory drawing which shows the state which made the web contact the nip forming roll in the fixing device which concerns on a modification.

[First embodiment]
An example of the fixing device and the image forming apparatus according to the first embodiment will be described.

〔overall structure〕
FIG. 1 shows an image forming apparatus 10 according to the first embodiment. As an example, the image forming apparatus 10 includes a transport unit 12 that transports a paper P, an image forming unit 14 that forms a toner image G using toner T on the transported paper P, and an image forming unit 14. And a fixing device 20 that fixes the toner image G to the paper P. The paper P is an example of a recording medium. The toner T is an example of a developer. The toner image G is an example of a developer image. The image forming unit 14 is an example of a forming unit. The image forming unit 14 performs each process of charging, exposure, development, transfer, and cleaning. In the fixing device 20, as an example, the paper P is conveyed from the −X side to the X side.

  In the following description, the direction indicated by the arrow Y in FIG. 1 is the height direction of the image forming apparatus 10, and the direction indicated by the arrow X in FIG. In addition, a direction (indicated by Z) orthogonal to each of the height direction and the width direction is a depth direction. When the image forming apparatus 10 is viewed from the side where a user (not shown) stands (when viewed from the front), the width direction, the height direction, and the depth direction are described as an X direction, a Y direction, and a Z direction. Further, when it is necessary to distinguish one side and the other side in the X direction, the Y direction, and the Z direction, when the image forming apparatus 10 is viewed from the front, the upper side is the Y side, the lower side is the -Y side, and the right side is X side, left side is described as -X side, back side (rear side) is described as Z side, and front side is described as -Z side.

[Main part configuration]
Next, the fixing device 20 will be described.

  As shown in FIG. 2, the fixing device 20 includes a belt 22, a light source unit 24 as an example of a light irradiation unit, a nip forming roll 26 as an example of a light collecting member, and a leveling member 28. Further, the fixing device 20 includes support rolls 32, 33, 34, an opposing roll 35, a pressure roll 36, and an oil application member 38. The support rolls 32, 33, and 34 are provided inside the belt 22 so as to be rotatable about the Z direction as an axial direction, and support the belt 22. The facing roll 35 is provided at a position facing the support roll 34 outside the belt 22 and is rotatable about the Z direction as an axial direction. The pressure roll 36 is provided outside the belt 22 so as to be rotatable about the Z direction as an axial direction, and pressurizes the belt 22 toward a nip forming roll 26 described later.

<Belt>
The belt 22 is endless and transparent, and transmits laser light Bm from a light source unit 24 described later. In FIG. 2, the laser beam Bm is simplified and indicated by a single solid line. The definition of “transparency” will be described later. The belt 22 has a four-layer structure having an elastic layer, a base material layer, an intermediate layer, and a release layer (not shown) as an example. A primer layer (not shown) for improving adhesiveness is formed between the elastic layer, the base material layer, the intermediate layer, and the release layer. Silicon oil OL (see FIG. 3B) as an example of a liquid adheres to the inner peripheral surface 22A of the belt 22 by an oil application member 38 described later. The outer peripheral surface 22B of the belt 22 is in contact with the toner image G on the paper P.

(Elastic layer)
The elastic layer is the innermost layer disposed on the innermost side of the belt 22 on the nip forming roll 26 and is exposed. Further, as an example, the elastic layer is made of silicone rubber that is thicker than a base material layer described later, and transmits the laser beam Bm. The “elastic layer” in the present embodiment is a layer that is elastically deformed to a greater extent in the thickness direction than the base material layer when pressed in a nip portion N described later. Examples of materials other than silicone rubber include chloroprene rubber, butyl rubber, acrylic rubber, urethane rubber, nitrile rubber, fluorine rubber, and styrene butadiene rubber.

(Base material layer)
The base material layer is a layer for maintaining the necessary strength as the belt 22. Moreover, the base material layer is comprised with the polyimide as an example, and permeate | transmits the laser beam Bm. In addition to polyimide, usable materials include polyvinylidene fluoride (PVDF), polyethylene (PE), polyurethane (PU), and polydimethylsiloxane (PDMS). Examples of materials that can be used other than polyimide include polyether ether ketone (PEEK), polyether sulfone (PES), fluorinated ethylene propylene (FEP), and ethylene tetrafluoroethylene copolymer (ETFE). Further, materials that can be used other than polyimide include chlorotrifluoroethylene (CTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and polytetrafluoroethylene (PTFE). In addition, you may comprise a base material layer by the combination of said material.

(Middle layer)
As an example, the intermediate layer is made of silicone rubber and transmits the laser beam Bm. In this embodiment, as an example, the elastic layer and the intermediate layer are made of the same material (silicone rubber).

(Release layer)
For example, the release layer is made of tetrafluoroethylene perfluoroalkoxyethylene copolymer (PFA) and transmits the laser beam Bm. Further, the release layer suppresses the adhesion of the toner image G to the belt 22 as compared with the configuration without the release layer. Examples of other materials constituting the release layer include tetrafluoroethylene polymer (PTFE), tetrafluoroethylene hexafluoropropylene copolymer (FEP), and ethylene tetrafluoroethylene copolymer (ETFE). . The release layer also has a function of giving a preferable gloss to the toner image G after fixing in cooperation with the intermediate layer.

  The belt 22 is wound around support rolls 32, 33, and 34 and a nip forming roll 26 described later. The belt 22 rotates around the support roll 32 by being rotated by a gear and a motor (not shown). Here, a portion where the belt 22 and the paper P are sandwiched between a nip forming roll 26 and a pressure roll 36, which will be described later, and the toner image G is pressed is referred to as a nip portion N. The nip portion N is a portion where the toner image G on the paper P is heated by a laser beam Bm from the light source unit 24 described later. The belt 22 transmits the laser beam Bm at the nip portion N and contacts the toner image G on the paper P.

<Oil application member>
As an example, the oil application member 38 is configured by impregnating silicon oil OL into a non-woven fabric formed in a rectangular shape with the Z direction as the longitudinal direction and the X direction as the short direction. The oil application member 38 is provided on the upstream side of the nip portion N in the circumferential movement direction of the belt 22 and on the downstream side of the support roll 34. The oil application member 38 has an X-side end supported by a bracket (not shown), and the −X-side end is in contact with the inner peripheral surface 22 </ b> A of the belt 22.

  Here, when the belt 22 is moved around, the silicon oil OL of the oil application member 38 is applied (supplied) to the inner peripheral surface 22A. Note that since the amount of the silicone oil OL is not controlled in the oil application member 38, the amount of the silicone oil OL applied to the inner peripheral surface 22A may vary in the Z direction.

<Light source unit>
In the present embodiment, as an example, the longitudinal direction of the light source unit 24 is the Z direction, the direction in which the laser beam Bm is applied to the toner image G is the Y direction, and the direction in which the paper P is conveyed is perpendicular to the Z direction and the Y direction. Each member is arrange | positioned so that it may become a X direction. As an example, the light source unit 24 includes a plurality of laser arrays 42 (see FIG. 4B) as an example of a plurality of light source units, and a beam shaping unit 44. The light source unit 24 is disposed inside the belt 22 and irradiates the laser beam Bm toward the −Y side so that the laser beam Bm enters a nip forming roll 26 described later. Then, the light source unit 24 irradiates the toner image G with the laser beam Bm at the nip portion N through the nip forming roll 26 and the belt 22. The laser beam Bm is an example of light.

  As shown in FIG. 4B, as an example, the plurality of laser arrays 42 are arranged at a set interval d set along the Z direction when viewed from the X direction. The distance from the center of the laser array 42 in the Z direction to the center of the adjacent laser array 42 in the Z direction is set as a set interval d. The plurality of laser arrays 42 are configured to emit laser light Bm toward the -Y side (nip forming roll 26 side). The plurality of laser arrays 42 are arranged so that the laser beam Bm is diffused in the Z direction and the laser beams Bm from adjacent laser arrays 42 partially overlap in the Z direction when viewed from the X direction. Yes.

  The beam shaping unit 44 shown in FIG. 4A converts the laser light Bm emitted from the plurality of laser arrays 42 (see FIG. 4B) to the −Y side as parallel light when viewed from the Z direction. A collimating lens (not shown) is included. In FIG. 4A, illustration of the pressure roll 36 (see FIG. 2) and the silicon oil OL adhering to the inner peripheral surface 22A after the nip portion N is omitted. As shown in FIG. 4B, when the beam shaping unit 44 is viewed from the X direction, the laser beam Bm is diffused in the Z direction.

<Nip forming roll>
The nip forming roll 26 shown in FIG. 2 is configured by a transparent glass roll that is a cylindrical (solid) rod lens, for example. Further, the nip forming roll 26 is provided on the inner side of the belt 22 on the −Y side with respect to the light source unit 24 and on the Y side of the transport path K on which the paper P is transported so as to be rotatable about the Z direction. . The outer peripheral surface 26A of the nip forming roll 26 is in contact with a part of the inner peripheral surface 22A of the belt 22 in the absence of silicon oil OL. Further, the nip forming roll 26 transmits the laser beam Bm emitted from the light source unit 24 and collects the laser beam Bm toward a contact portion 29 and a nip portion N described later when viewed from the Z direction. It is configured. The optical axis of the laser beam Bm passes through the center of the nip forming roll 26 when the nip forming roll 26 is viewed from the Z direction.

  A portion where the laser beam Bm is incident on the outer peripheral surface 26 </ b> A of the nip forming roll 26 is referred to as an incident portion 27. The incident portion 27 is a range (part) including the top on the Y side in the Y direction of the nip forming roll 26 when the nip forming roll 26 is viewed from the Z direction. On the other hand, a portion of the outer peripheral surface 26 </ b> A shifted by 180 ° from the incident portion 27 is referred to as a contact portion 29. The contact portion 29 is a portion where the outer peripheral surface 26 </ b> A contacts with a part of the inner peripheral surface 22 </ b> A in the circumferential direction in the range where the belt 22 contacts the paper P.

  In the present embodiment, “transparent” of the belt 22 and the nip forming roll 26 means that the transmittance is sufficiently high in the wavelength region of the laser beam Bm. In other words, the belt 22 and the nip forming roll 26 only need to transmit the laser beam Bm. From the viewpoint of light utilization efficiency, the higher the transmittance, the better. As an example, the transmittance is 90% or more, preferably 95% or more.

<Pressure roll>
As an example, the pressure roll 36 shown in FIG. 2 has a configuration in which an elastic layer and a release layer (not shown) are formed on the outer peripheral surface of a stainless steel roll. The pressure roll 36 is provided on the −Y side with respect to the transport path K through which the paper P is transported so as to be rotatable about the Z direction as an axial direction. Further, the pressure roll 36 is arranged so that a predetermined pressing force acts between the pressure roll 36 and the nip forming roll 26. As described above, the pressure roll 36 presses the paper P and the belt 22 on which the toner image G is formed together with the nip forming roll 26, and conveys it to the X side. In other words, the pressure roll 36 presses the toner image G on the paper P and the belt 22 toward the nip forming roll 26 to form the nip portion N. As a result, the toner image G is heated and pressurized by the laser beam Bm at the nip portion N, and is fixed to the paper P.

<Leveling member>
As shown in FIG. 3, the leveling member 28 is formed in a rectangular flat plate shape that is long in the Z direction. In other words, the leveling member 28 is composed of a plate material (blade). Further, the leveling member 28 is made of a rubber material excellent in oil resistance and wear resistance, and as an example, made of fluoro rubber. Further, the leveling member 28 is arranged to face the outer peripheral surface 26 </ b> A along the Z direction (axial direction) of the nip forming roll 26.

  Specifically, the leveling member 28 is disposed on the downstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 and on the upstream side of the incident portion 27. Further, the leveling member 28 has one end side in the short direction fixed to a bracket (not shown) over the entire length in the Z direction, and the other end side (free end side) is opposite to the rotation direction of the nip forming roll 26. The nip forming roll 26 is disposed so as to face the outer peripheral surface 26A.

  In FIG. 3, the angle of the leveling member 28 with respect to the outer peripheral surface 26 </ b> A is in the forward direction with respect to the rotation direction of the nip forming roll 26 in order to easily show the contact portion between the leveling member 28 and the outer peripheral surface 26 </ b> A. Shown in an angled state. Actually, the leveling member 28 is arranged such that the angle of the leveling member 28 with respect to the outer peripheral surface 26 </ b> A is opposite to the rotation direction of the nip forming roll 26. The pressure acting on the contact portion between the leveling member 28 and the outer peripheral surface 26A is set to such a level that the leveling member 28 does not damage the outer peripheral surface 26A. In addition, this pressure is approximately the same in the Z direction.

  The leveling member 28 configured in this manner reduces the thickness of the silicon oil OL adhering to the outer peripheral surface 26A of the nip forming roll 26, and in the circumferential direction (rotating direction) and Z as the nip forming roll 26 rotates. It is leveled in the direction. The leveling member 28 also has a function of reducing the amount of excessive silicon oil OL adhering to the outer peripheral surface 26A to a preset amount.

(About laser light refraction)
Here, the refractive index of air light is about 1.0 (see JIS B 7071-1). Further, the refractive index of light of the silicon oil OL is about 1.4 (a general measurement value by a refractometer). That is, since the difference in refractive index between the air and the silicon oil OL is large, the laser beam Bm is likely to be scattered when it enters the silicon oil OL from the air. For this reason, if the adhesion amount and surface state of the silicon oil OL adhering to the outer peripheral surface 26A are different in the Z direction, the condensing state of the laser beam Bm in the nip portion N is different in the Z direction. For reference, the refractive index of light of the nip forming roll 26 is about 1.5 (see JIS B 7071-1).

[Action]
Next, the operation of the first embodiment will be described.

  In the fixing device 20 shown in FIG. 2, the laser beam Bm irradiated from the light source unit 24 toward the nip forming roll 26 is collected by the nip forming roll 26 and enters the nip portion N through the belt 22. In the nip portion N, the laser beam Bm is absorbed by the toner T (see FIG. 1) constituting the toner image G on the paper P. As a result, the toner image G is heated and pressurized by the pressure applied to the nip portion N, and is fixed to the paper P.

  In the fixing device 20, a part of the silicone oil OL adhering to the inner peripheral surface 22 </ b> A of the belt 22 is transferred to the nip forming roll 26 at a contact portion 29 between the nip forming roll 26 and the belt 22. The silicon oil OL transferred to the nip forming roll 26 moves toward the incident portion 27 as the nip forming roll 26 rotates.

  Here, the silicon oil OL is leveled by the leveling member 28 before reaching the incident portion 27. Specifically, the silicon oil OL enters between the nip forming roll 26 and the leveling member 28 as the nip forming roll 26 rotates, so that an excessive amount is scraped off (the amount of adhesion decreases). ). In other words, the amount of silicon oil OL is leveled in the rotational direction of the nip forming roll 26. Furthermore, since the silicone oil OL is pressurized toward the nip forming roll 26 by the leveling member 28, it spreads in the Z direction orthogonal to the rotation direction of the nip forming roll 26. That is, when there is a portion where the amount of silicon oil OL is small in a part of the outer peripheral surface 26A of the nip forming roll 26 in the Z direction, the silicon oil OL is also attached to this small portion.

  As described above, in the fixing device 20, the leveling member 28 scrapes off an excessive amount of silicon oil OL, and makes the amount of silicon oil OL adhering to the nip forming roll 26 approximately the same in the Z direction (leveling). . For this reason, compared with the structure which does not have the leveling member 28, the fluctuation | variation (fluctuation | variation of the quantity in the Z direction and the rotation direction of the nip forming roll 26) of the amount of silicone oil OL which reaches | attains the incident part 27 is suppressed. . As a result, the light quantity of the laser light Bm scattered by the silicon oil OL at the incident portion 27 is suppressed from being different in the Z direction, so that the laser light Bm condensed on the belt 22 as the nip forming roll 26 rotates. Fluctuation in the amount of light is suppressed.

  In the fixing device 20, the light condensing property of the laser light Bm to the toner T is suppressed by suppressing the fluctuation of the light amount of the laser light Bm condensed on the belt 22 with the rotation of the nip forming roll 26. Is suppressed from decreasing. In other words, the heating temperature of the toner T is suppressed from lowering than the set fixing temperature. As a result, the amount of heat necessary for fixing can be applied to the toner T, so that deterioration of the fixability of the toner image G onto the paper P can be suppressed as compared with a configuration in which the leveling member 28 is not provided. Note that the deterioration of the fixing property means that the fixing failure of the toner image G locally occurs or uneven glossiness occurs, for example, a cold offset of the toner image G.

  Further, in the fixing device 20, the leveling member 28 is disposed downstream of the contact portion 29 and upstream of the incident portion 27 in the rotation direction of the nip forming roll 26. For this reason, even if the variation in the amount of silicon oil OL transferred from the belt 22 to the nip forming roll 26 at the contact portion 29 is large in the Z direction and the rotation direction, the silicon oil leveled by the leveling member 28 OL reaches the incident portion 27. As a result, the light amount of the laser beam Bm collected on the belt 22 may fluctuate as compared with the configuration in which the leveling member 28 is disposed upstream of the contact portion 29 and downstream of the incident portion 27. It is suppressed. Then, deterioration of the fixability of the toner image G onto the paper P is suppressed.

  Further, in the fixing device 20, the leveling member 28 is configured by a plate material (blade) that is disposed so as to face the outer peripheral surface 26 </ b> A along the Z direction and reduces silicon oil OL attached to the outer peripheral surface 26 </ b> A. For this reason, the amount of silicon oil OL on the downstream side of the leveling member 28 on the outer peripheral surface 26A is smaller than the amount of silicon oil OL on the upstream side. Thereby, compared with the structure which equalizes without reducing the quantity of silicon oil OL, it is suppressed that the quantity of silicone oil OL becomes excessive in the incident part 27. FIG.

  In the image forming apparatus 10 shown in FIG. 1, since the deterioration of the fixability of the toner image G in the fixing device 20 is suppressed, an image defect after fixing (for example, a reduction in image glossiness) is suppressed.

  As a means for grasping the amount of light collected on the belt 22, it can be determined from a two-dimensional light amount distribution observed with a camera (CCD or the like) focused on the light collection position of the belt 22. In addition, as a means for indirectly grasping the light amount, there is a method in which a thermal paper or the like is placed at the condensing position of the belt 22 and the determination is made from the color change caused by laser irradiation and the width thereof.

[Second Embodiment]
Next, an example of a fixing device and an image forming apparatus according to the second embodiment will be described. Note that the same reference numerals as those in the first embodiment are given to the same members and parts as those in the first embodiment described above, and the description thereof is omitted.

  FIG. 5 shows a part of the fixing device 50 according to the second embodiment. The fixing device 50 is configured such that a leveling member 52 is provided in place of the leveling member 28 (see FIG. 2) in the fixing device 20 (see FIG. 2). The configuration other than the leveling member 52 is the same as that of the fixing device 20.

<Leveling member>
As an example, the leveling member 52 is constituted by a fluorine rubber blade formed in a flat plate shape elongated in the Z direction. Further, the leveling member 52 is disposed to face the outer peripheral surface 26A along the Z direction. Further, the leveling member 52 is disposed on the downstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 and on the upstream side of the incident portion 27. In addition, the leveling member 52 is fixed to a bracket (not shown) at one end side in the short direction, and the other end side (free end side) faces the opposite direction to the rotation direction of the nip forming roll 26. It is in contact with the outer peripheral surface 26 </ b> A of the forming roll 26.

  In FIG. 5, the angle of the leveling member 52 with respect to the outer peripheral surface 26 </ b> A is in the forward direction with respect to the rotation direction of the nip forming roll 26 in order to easily show the contact portion between the leveling member 52 and the outer peripheral surface 26 </ b> A. Shown in an angled state. The pressure acting on the contact portion between the leveling member 52 and the outer peripheral surface 26A is set to such a level that the leveling member 52 does not damage the outer peripheral surface 26A. In addition, this pressure is approximately the same in the Z direction.

  Further, in the leveling member 52, a portion facing the outer peripheral surface 26A (hereinafter referred to as an end 52A) is formed in a corrugated shape. Specifically, the shape of the end portion 52A is, for example, as viewed from the tangential direction of the nip forming roll 26 perpendicular to the direction in which the nip forming roll 26 and the leveling member 52 are aligned. It has a sine wave shape with a period equal to or shorter than the set interval d (see FIG. 4B). The set interval d is the pitch of the plurality of laser arrays 42. This sine wave has a shape in which peaks and valleys in the X direction are periodically repeated in the Z direction. When the length of the end portion 52A in the Z direction from the peak portion to the peak portion (the length in the Z direction from the valley portion to the valley portion) is L1, L1 <d. Note that L1 = d may be set.

[Action]
Next, the operation of the second embodiment will be described.

  In the fixing device 50 shown in FIG. 6A, the laser beam Bm irradiated from the light source unit 24 toward the nip forming roll 26 is condensed by the nip forming roll 26 and enters the nip portion N through the belt 22. In the nip portion N, the laser beam Bm is absorbed by the toner T on the paper P. As a result, the toner image G is heated and pressurized by the pressure applied to the nip portion N, and is fixed to the paper P. In the fixing device 50, the silicone oil OL transferred to the nip forming roll 26 at the contact portion 29 moves toward the incident portion 27 as the nip forming roll 26 rotates. In FIG. 6A, illustration of the pressure roll 36 (see FIG. 2) and the silicon oil OL adhering to the inner peripheral surface 22A after the nip portion N is omitted.

  Here, the silicon oil OL is leveled by the leveling member 52 before reaching the incident portion 27. Specifically, the silicone oil OL enters between the nip forming roll 26 and the leveling member 52 as the nip forming roll 26 rotates, so that an excessive amount is scraped off (the amount of adhesion decreases). ). In other words, the amount of silicon oil OL is leveled in the rotational direction of the nip forming roll 26. Further, a part of the silicone oil OL is pressurized toward the nip forming roll 26 by the leveling member 52, and therefore spreads in the Z direction perpendicular to the rotation direction of the nip forming roll 26. That is, when there is a portion where the amount of silicon oil OL is small in a part of the outer peripheral surface 26A of the nip forming roll 26 in the Z direction, the silicon oil OL is also attached to this small portion.

  As described above, in the fixing device 50, the leveling member 52 scrapes off an excessive amount of silicon oil OL and makes the amount of silicon oil OL adhering to the nip forming roll 26 approximately equal in the Z direction. For this reason, compared with the structure which does not have the leveling member 52, the fluctuation | variation (variation in the Z direction and the rotation direction of the nip forming roll 26) of the amount of silicon oil OL which reaches | attains the incident part 27 is suppressed. As a result, the light amount of the laser light Bm scattered by the silicon oil OL at the incident portion 27 is suppressed, so that the light amount of the laser light Bm collected on the belt 22 as the nip forming roll 26 rotates. Is suppressed from fluctuating.

  In the fixing device 50, the light condensing property of the laser light Bm onto the toner T is suppressed by suppressing the fluctuation of the light amount of the laser light Bm condensed on the belt 22 with the rotation of the nip forming roll 26. Is suppressed from decreasing. In other words, the heating temperature of the toner T is suppressed from lowering than the set fixing temperature. As a result, the amount of heat necessary for fixing can be applied to the toner T, so that deterioration of the fixability of the toner image G onto the paper P can be suppressed as compared with a configuration in which the leveling member 52 is not provided. The deterioration of the fixing property is as described above.

  In the fixing device 50, the leveling member 52 is disposed downstream of the contact portion 29 and upstream of the incident portion 27 in the rotation direction of the nip forming roll 26. For this reason, even if the variation in the amount of silicon oil OL transferred from the belt 22 to the nip forming roll 26 at the contact portion 29 is large in the Z direction and the rotational direction, the silicon oil leveled by the leveling member 52 OL reaches the incident portion 27. As a result, the amount of the laser beam Bm condensed on the belt 22 may vary as compared with the configuration in which the leveling member 52 is disposed on the upstream side of the contact portion 29 and on the downstream side of the incident portion 27. It is suppressed. Then, deterioration of the fixability of the toner image G onto the paper P is suppressed.

  Further, in the fixing device 50, the leveling member 52 is configured by a blade that is disposed so as to face the outer peripheral surface 26A along the Z direction and reduces the silicon oil OL adhering to the outer peripheral surface 26A. For this reason, since the pressure of the part which contacts 26 A of outer peripheral surfaces becomes substantially the same in a Z direction, compared with the structure which provided the leveling member 52 in a part of Z direction, the silicon oil OL adhering to 26 A of outer peripheral surfaces It is suppressed that the amount of is excessive in part in the Z direction.

  In addition, as shown in FIG. 5, in the fixing device 50, the shape of the end portion 52 </ b> A facing the outer peripheral surface 26 </ b> A of the leveling member 52 has a period equal to or shorter than the set interval d (see FIG. 6B). It is formed in a wave shape. For this reason, a force toward the Z side and the −Z side with respect to the rotation direction of the nip forming roll 26 acts on the silicone oil OL that has contacted the peak portion of the end portion 52A. The silicon oil OL is formed with a high peak portion in the radial direction (X direction) and a low valley portion in the radial direction at intervals in the Z direction, in other words, nip formation. Silicon oil OL is applied to the outer peripheral surface 26A of the roll 26 in a plurality of stripes.

  As shown in FIG. 6B, the laser beam Bm incident on the silicon oil OL is refracted in accordance with the surface shapes of the peaks and valleys at the peaks and valleys of the silicon oil OL. Specifically, the laser beam Bm incident on the silicon oil OL is refracted in the Z direction. Accordingly, in the fixing device 50 shown in FIG. 5, when viewed from the tangential direction of the nip forming roll 26, the portion of the leveling member 52 facing the outer peripheral surface 26 </ b> A has a linear configuration along the Z direction. In comparison, the laser beam Bm is diffused in the Z direction.

  The fact that the laser beam Bm is diffused in the Z direction means that the optical path length from the laser array 42 to the nip forming roll 26 is lengthened so that it is not necessary to diffuse the laser beam Bm in the Z direction. In other words, in the fixing device 50, it is not necessary to lengthen the optical path length from the laser array 42 (see FIG. 6B) to the nip forming roll 26 in order to secure the amount of overlapping of the laser light Bm in the Z direction. The fixing device 50 is downsized as compared with the configuration in which the optical path length is increased.

  In the fixing device 50, the silicon oil OL is applied to the outer peripheral surface 26A in a streak shape, but the streaks of the silicon oil OL have periodicity in the Z direction. For this reason, by adjusting the arrangement of the laser array 42 in advance in accordance with this periodicity, the amount of the laser beam Bm focused on the nip portion N is suppressed from changing in the Z direction.

  In the image forming apparatus 10 having the fixing device 50 (see FIG. 1), since the deterioration of the fixing property of the toner image G in the fixing device 50 is suppressed, image defect after fixing (for example, reduction in glossiness of the image) is suppressed. Is done.

[Third embodiment]
Next, an example of a fixing device and an image forming apparatus according to the third embodiment will be described. The same reference numerals as those in the first and second embodiments are given to the same members and parts as those in the first and second embodiments described above, and the description thereof is omitted.

  FIG. 7 shows a part of the fixing device 60 of the third embodiment. The fixing device 60 is configured such that a leveling member 62 is provided in place of the leveling member 28 (see FIG. 2) in the fixing device 20 (see FIG. 2). The configuration other than the leveling member 62 is the same as that of the fixing device 20.

<Leveling member>
For example, the leveling member 62 is disposed downstream of the contact portion 29 and upstream of the incident portion 27 in the rotation direction of the nip forming roll 26. Further, the leveling member 62 is disposed to face the outer peripheral surface 26A along the Z direction. Further, the leveling member 62 includes a blade 64 and a web 66 as an example of a replenishing member. Since the blade 64 has the same configuration as the leveling member 52 (see FIG. 5), the description thereof is omitted.

  In FIG. 7, the angle of the blade 64 and the web 66 with respect to the outer peripheral surface 26 </ b> A is set to the forward direction with respect to the rotation direction of the nip forming roll 26 in order to easily show the contact portion between the blade 64 and the web 66 and the outer peripheral surface 26 </ b> A. It has shown in the state arrange | positioned at the angle which becomes. The pressure acting on the contact portion between the blade 64 and the web 66 and the outer peripheral surface 26A is set to such a pressure that the blade 64 and the web 66 do not damage the outer peripheral surface 26A. In addition, this pressure is approximately the same in the Z direction.

(web)
The web 66 is configured by impregnating a band-like (sheet-like) fibrous body with silicon oil OL. The amount of silicon oil OL impregnated in the web 66 is smaller than the amount of silicon oil OL impregnated in the oil application member 38 (see FIG. 2). Moreover, the web 66 is formed in the rectangular shape which makes a Z direction a longitudinal direction and makes a X direction a transversal direction as an example. Further, the web 66 is disposed downstream of the contact portion 29 in the rotational direction of the nip forming roll 26 and upstream of the blade 64. In other words, the blade 64 is disposed downstream of the web 66 and upstream of the incident portion 27. Further, the web 66 is disposed to face the outer peripheral surface 26A along the Z direction.

  The web 66 has one end on the X side supported by a bracket (not shown), and the end on the −X side (the end on the free end) faces the opposite direction to the rotation direction of the nip forming roll 26. It is in contact with the outer peripheral surface 26 </ b> A of the forming roll 26. Further, the web 66 is disposed to face the outer peripheral surface 26A along the Z direction.

[Action]
Next, the operation of the third embodiment will be described.

  In the fixing device 60, the laser beam Bm irradiated from the light source unit 24 (see FIG. 2) toward the nip forming roll 26 is collected by the nip forming roll 26 and enters the nip portion N through the belt 22. In the nip portion N, the laser beam Bm is absorbed by the toner T on the paper P (see FIG. 2). As a result, the toner image G is heated and pressurized by the pressure applied to the nip portion N (see FIG. 2), and is fixed to the paper P. In the fixing device 60, the silicone oil OL transferred to the nip forming roll 26 at the contact portion 29 moves toward the incident portion 27 as the nip forming roll 26 rotates.

  Here, the silicon oil OL is leveled by the leveling member 62 before reaching the incident portion 27. Specifically, first, the silicon oil OL is supplied to the outer peripheral surface 26 </ b> A of the nip forming roll 26 by the web 66. Specifically, when the silicone oil OL is transferred from the belt 22 to the nip forming roll 26, if there is a portion where the amount of the silicone oil OL is small in a part in the Z direction, the silicone oil OL is supplied to this portion. Is done. For this reason, since a certain amount of silicon oil OL adheres to the outer peripheral surface 26A before leveling by the blade 64, the difference in the amount of silicon oil OL adhered in the Z direction becomes small. Thereby, compared with the structure in which the leveling member 62 does not have the web 66, the amount of silicon oil OL adhering to the outer peripheral surface 26A on the downstream side of the leveling member 62 varies in the Z direction (axial direction). Is suppressed.

  Subsequently, as the nip forming roll 26 rotates, the silicone oil OL enters between the nip forming roll 26 and the blade 64, so that an excessive amount is scraped off (adhesion amount is reduced). In other words, the amount of silicon oil OL is leveled in the rotational direction of the nip forming roll 26. Further, a part of the silicone oil OL is pressurized toward the nip forming roll 26 by the blade 64, and therefore spreads in the Z direction. As described above, in the fixing device 60, the leveling member 62 replenishes the silicon oil OL and sets the amount of the silicon oil OL on the nip forming roll 26 to the same level in the Z direction. For this reason, compared with the structure which does not have the leveling member 62, the fluctuation | variation (variation in the Z direction and the rotation direction of the nip forming roll 26) of the amount of silicon oil OL which reaches | attains the incident part 27 is suppressed. As a result, the light amount of the laser light Bm scattered by the silicon oil OL at the incident portion 27 is suppressed, so that it is condensed on the belt 22 (see FIG. 2) as the nip forming roll 26 rotates. Fluctuation of the light amount of the laser beam Bm is suppressed.

  In the fixing device 60, the light condensing property of the laser light Bm onto the toner T is suppressed by suppressing the fluctuation of the light amount of the laser light Bm condensed on the belt 22 with the rotation of the nip forming roll 26. Is suppressed from decreasing. In other words, the heating temperature of the toner T is suppressed from lowering than the set fixing temperature. As a result, the amount of heat necessary for fixing can be applied to the toner T, so that deterioration of the fixability of the toner image G onto the paper P can be suppressed as compared with the configuration without the leveling member 62. The deterioration of the fixing property is as described above.

  In the fixing device 60, the leveling member 62 is disposed downstream of the contact portion 29 and upstream of the incident portion 27 in the rotation direction of the nip forming roll 26. For this reason, even when the variation in the amount of silicon oil OL transferred from the belt 22 to the nip forming roll 26 at the contact portion 29 is large in the Z direction and the rotational direction, the silicon oil leveled by the leveling member 62 OL reaches the incident portion 27. As a result, the light amount of the laser beam Bm condensed on the belt 22 may fluctuate as compared with the configuration in which the leveling member 62 is disposed upstream of the contact portion 29 and downstream of the incident portion 27. It is suppressed. Then, deterioration of the fixability of the toner image G onto the paper P is suppressed.

  In the image forming apparatus 10 having the fixing device 60 (see FIG. 1), since the deterioration of the fixing property of the toner image G in the fixing device 60 is suppressed, image defect after fixing (for example, reduction in glossiness of the image) is suppressed. Is done.

  In addition, this invention is not limited to said embodiment.

<Modification>
As shown in FIG. 8, in the fixing device 60, the leveling member 62 may be constituted by a web 66 formed in a blade shape, except for the blade 64 (see FIG. 7). Since the web 66 is configured in a blade shape, not only the function of supplying the silicon oil OL to the outer peripheral surface 26A but also the silicon oil OL on the outer peripheral surface 26A is leveled in the circumferential direction (rotating direction) and the Z direction. It also has a function. Further, the end of the web 66 on the nip forming roll 26 side may be formed in a corrugated shape. Further, the wave-like period may be a period equal to or shorter than the set interval d (see FIG. 4B). If it is desired to further diffuse the laser beam Bm in the Z direction, the blade 64 may be disposed as described above. Further, in the fixing device 20 (see FIG. 2) and the fixing device 50 (see FIG. 5), the leveling members 28 and 52 may be configured by a web 66 formed in a blade shape or a wave shape.

<Other variations>
The leveling members 28, 52, 62 are upstream of the contact portion 29 in the rotation direction of the nip forming roll 26 (upstream side of the portion where the nip forming roll 26 and the belt 22 are in contact) and downstream of the incident portion 27. It may be arranged on the side. By pre-equalizing the outer peripheral surface 26A of the nip forming roll 26 that rotates toward the contact portion 29 before the silicon oil OL adheres, the amount of silicon oil OL adhering to the outer peripheral surface 26A is prevented from varying in the Z direction. The

  Further, the leveling members 28, 52 and 62 may be arranged such that the other end side (free end side) faces the forward direction (the same direction) with respect to the rotation direction of the nip forming roll 26. Furthermore, you may provide collection | recovery parts, such as a container which collect | recovers silicone oil OL, in the peripheral part of the leveling members 28, 52, and 62.

  In the fixing device 20, the leveling member 28 may be constituted by the web 66. In the fixing device 50, the wave period of the end 52 </ b> A of the leveling member 52 may be larger than the set interval d of the plurality of laser arrays 42. This is because the silicon oil OL is leveled in the Z direction by the peaks and valleys.

  The nip forming roll 26 is not limited to a solid one and may be a hollow one as long as the laser beam Bm is condensed (converged) toward the nip portion N. Further, the nip forming roll 26 is not limited to glass but may be made of resin such as acrylic.

  The method of applying the silicone oil OL to the inner peripheral surface 22 </ b> A of the belt 22 is not limited to the method of always applying using the oil applying member 38. Instead of using the oil application member 38, a method may be used in which the silicon oil OL is applied to the inner peripheral surface 22A when the fixing devices 20, 50, 60 are assembled (manufactured in a factory). The oil application member 38 is not limited to a blade shape, and may be a roll. The liquid is not limited to silicon oil, and other lubricating oils may be used.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 14 Image forming part (an example of a forming means)
20 fixing device 22 belt 22A inner peripheral surface 24 light source unit (an example of light irradiation means)
26 Nip forming roll (an example of a light collecting member)
26A Outer peripheral surface 28 Leveling member 29 Contact portion 42 Laser array (an example of a light source portion)
50 Fixing device 52 Leveling member 60 Fixing device 62 Leveling member 66 Web (an example of a supply member)
OL Silicon oil (an example of liquid)

Claims (6)

A belt that is endless and transparent, the liquid adheres to the inner peripheral surface, and the outer peripheral surface contacts the developer image on the recording medium;
A light irradiating means disposed inside the belt for irradiating light;
A contact portion provided rotatably inside the belt and in contact with a part of the inner peripheral surface in a range of contact with the recording medium of the belt; and the light irradiated from the light irradiation means A condensing member that condenses toward
A leveling member for leveling the liquid adhering to the light collecting member;
A fixing device.   2. The fixing according to claim 1, wherein the leveling member is disposed on the downstream side of the contact portion in the rotation direction of the light collecting member and on the upstream side of the light incident portion on the light collecting member. apparatus.   The leveling member is formed of a plate material that is disposed opposite to the outer peripheral surface of the light collecting member along the axial direction of the light collecting member and reduces the amount of liquid attached to the outer peripheral surface of the light collecting member. The fixing device according to claim 1 or 2.   4. The fixing device according to claim 1, wherein the leveling member includes a replenishing member that is impregnated with a liquid and replenishes the liquid on an outer peripheral surface of the light collecting member. The light irradiating means has a plurality of light source parts arranged at set intervals set along the axial direction of the light collecting member,
The leveling member is disposed opposite to the outer peripheral surface of the light collecting member along the axial direction of the light collecting member,
When the shape of the portion facing the outer peripheral surface of the light collecting member in the leveling member is viewed from the tangential direction of the light collecting member orthogonal to the direction in which the light collecting member and the leveling member are arranged, 5. The fixing device according to claim 1, wherein the fixing device has a wave shape with a period equal to or less than a set interval. Forming means for forming a developer image on a recording medium;
The fixing device according to any one of claims 1 to 5, wherein the developer image on the recording medium formed by the forming unit is fixed to the recording medium.
An image forming apparatus.