Foil transfer apparatus

A foil transfer apparatus that transfers foil of a foil film to a sheet, including: a heating member and a pressurizing member that nip the foil film and the sheet; a movable frame supporting one of the heating member and the pressurizing member and movable between a first position at which the one of the heating member and the pressurizing member is located at a contact position so as to contact the foil film in a mounted state in which the foil film is mounted on a housing body and a second position at which the one of the heating member and the pressurizing member is located at a spaced position so as to be spaced from the foil film in the mounted state; a cam that moves the movable frame between the first position and the second position; and a sensor that detects a position of the movable frame.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Japanese Patent Application No. 2020-168834, which was filed on Oct. 6, 2020, the disclosure of which is herein incorporated by reference in its entirety.

BACKGROUND

Technical Field

The following disclosure relates to a foil transfer apparatus configured to transfer foil to a sheet.

Description of Related Art

A conventionally known foil transfer apparatus includes a heating member that heats a foil film and a sheet and a pressurizing member that cooperates with the heating member to nip the foil film and the sheet therebetween. The known foil transfer apparatus includes: a position change mechanism that moves the heating member between a contact position at which the heating member contacts the foil film and a spaced position at which the heating member is spaced apart from the foil film; and a sensor that detects a position of the heating member.

SUMMARY

In the foil transfer apparatus constructed as described above, the sensor for detecting the position of the heating member may be configured to detect a phase of a cam that moves the heating member, for instance. However, in a case where the heating member does not move even though the cam moves, the sensor may fail to accurately detect the position of the heating member.

Accordingly, an aspect of the present disclosure is directed to a technique of accurately detecting a position of a heating member capable of coming into contact with and moving away from a foil film.

In one aspect of the present disclosure, a foil transfer apparatus configured to superpose a sheet on a foil film including foil and to transfer the foil to the sheet includes: a housing body; a heating member configured to heat the foil film and the sheet; a pressurizing member configured to cooperate with the heating member to nip the foil film and the sheet therebetween; a movable frame supporting one of the heating member and the pressurizing member, the movable frame being movable between i) a first position at which the one of the heating member and the pressurizing member is located at a contact position at which the one of the heating member and the pressurizing member is in contact with the foil film in a state in which the foil film is mounted on the housing body and ii) a second position at which the one of the heating member and the pressurizing member is located at a spaced position at which the one of the heating member and the pressurizing member is spaced apart from the foil film in the state in which the foil film is mounted on the housing body; a cam configured to move the movable frame between the first position and the second position; and a sensor configured to detect a position of the movable frame.

DETAILED DESCRIPTION OF THE EMBODIMENT

Referring to the drawings, there will be hereinafter described a foil transfer apparatus according to one embodiment of the present disclosure. In the following description, directions are explained based on directions illustrated inFIG.1A. That is, a right side and a left side inFIG.1Aare respectively defined as a front side and a rear side of the foil transfer apparatus, and a front side and a rear side of the sheet ofFIG.1Aare respectively defined as a left side and a right side of the foil transfer apparatus. An upper side and a lower side inFIG.1Aare respectively defined as an upper side and a lower side of the foil transfer apparatus.

The foil transfer apparatus denoted at1inFIG.1Ais configured to superpose a sheet S on a foil film F including foil and to transfer the foil to the sheet S. As illustrated inFIG.1A, the foil transfer apparatus1is configured to transfer the foil such as aluminum on a toner image formed on the sheet S by an image forming apparatus such as a laser printer. The foil transfer apparatus1includes a housing2, a sheet tray3, a sheet conveyor10, a film supplier30, a transfer device50, and a controller100that controls the foil transfer apparatus1.

The housing2is formed of a resin, for instance, and includes a housing body21and a cover22. The housing body21has, at an upper portion thereof, an opening21A (FIG.2). The opening21A is for mounting and dismounting a film unit FU (that will be described) on and from the housing body21. The opening21A faces upward. The cover22is a member for opening and closing the opening21A. The cover22is pivotably supported at a rear end portion thereof by the housing body21. The cover22is movable between a closed position at which the cover22closes the opening21A and an open position at which the cover22exposes the opening21A. In the present embodiment, the cover22is configured to be opened in a direction different from a conveying direction of the sheet S.

A sheet tray3is a tray on which the sheets S such as paper and OHP films are placed. The sheet tray3is disposed at a rear portion of the housing2. Each of the sheets S is placed on the sheet tray3such that a surface thereof, on which the toner image has been formed, faces downward.

The sheet conveyor10includes a sheet supply mechanism11and a sheet discharge mechanism12. The sheet supply mechanism11is configured to convey the sheets S on the sheet tray3one by one toward the transfer device50. The sheet supply mechanism11includes a pickup roller11A, a retard roller11B, and upstream conveyor rollers11C.

The pickup roller11A is configured to supply the sheet S on the sheet tray3toward the transfer device50. The retard roller11B is for separating one of the sheets S that is to be sent by the pickup roller11A from the others.

The retard roller11B is disposed above the pickup roller11A. The retard roller11B is rotatable in a direction to return the sheets S superposed on the one of the sheet S that is to be sent by the pickup roller11A toward the sheet tray3.

The upstream conveyor rollers11C are constituted by two rollers. The two rollers are rotated in a state in which the sheet S is nipped therebetween to thereby convey the sheet S. The upstream conveyor rollers11C are disposed between the pickup roller11A and the transfer device50and convey, to the transfer device50, the sheet S sent by the pickup roller11A.

The sheet discharge mechanism12is a mechanism for discharging, to outside the housing2, the sheet S that has passed the transfer device50. The sheet discharge mechanism12includes downstream conveyor rollers12A (each as one example of a conveyor roller) and discharge rollers12B.

The downstream conveyor rollers12A and the discharge rollers12B are both constituted by two rollers. The two rollers of each of the downstream conveyor rollers12A and the discharge rollers12B are rotated in a state in which the sheet S is nipped therebetween to thereby convey the sheet S. The downstream conveyor rollers12A are located downstream of a second guide shaft42(that will be described) in the conveying direction of the sheet S. In the following explanation, the conveying direction of the sheet S will be simply referred to as “conveying direction” where appropriate.

Specifically, the downstream conveyor rollers12A are rollers that are the closest to the second guide shaft42among the plurality of rollers (12A,12B) for conveying the sheet S that are located downstream of the second guide shaft42in the conveying direction. The downstream conveyor rollers12A are disposed between the second guide shaft42and the discharge rollers12B in the conveying direction. The downstream conveyor rollers12A convey the sheet S sent from the transfer device50toward the discharge rollers12B.

The discharge rollers12B are located downstream of the downstream conveyor rollers12A in the conveying direction. The discharge rollers12B discharge, to outside the housing2, the sheet S sent from the downstream conveyor rollers12A.

The film supplier30is configured to supply the foil film F such that the foil film F is superposed on the sheet S conveyed from the sheet supply mechanism11. The film supplier30includes a film unit FU and a motor80.

The film unit FU is mountable to and dismountable from the housing body21from an upper side, as illustrated inFIG.2. The film unit FU includes a supply reel31, a take-up reel35, a first guide shaft41, the second guide shaft42(as one example of a separating member), and a third guide shaft43(as one example of an angle defining member). The foil film F is wound around the supply reel31of the film unit FU.

As illustrated inFIG.1B, the foil film F includes a supporting layer F1and a supported layer F2. The supporting layer F1is a tape-like transparent base formed of a high molecular material. The supporting layer F1supports the supported layer F2.

The supported layer F2includes a separation layer F21, a transfer layer F22, and an adhesive layer F23. The separation layer F21is a layer for permitting the transfer layer F22to be easily peeled off from the supporting layer F1. The separation layer F21is disposed between the supporting layer F1and the transfer layer F22. The separation layer F21contains a transparent material, such as a wax resin, that permits itself to be easily peeled off from the supporting layer F1.

The transfer layer F22is a layer to be transferred to the toner image. The transfer layer F22contains foil. The foil is a thin metal such as gold, silver, copper, or aluminum. The transfer layer F22contains a thermoplastic resin and a colorant such as a gold colorant, a silver colorant, or a red colorant. The transfer layer F22is disposed between the separation layer F21and the adhesive layer F23.

The adhesive layer F23is a layer for permitting the transfer layer F22to be easily bonded to the toner image. The adhesive layer F23contains a material, such as a polyvinyl chloride resin or an acrylic resin, that is easily bonded to the toner image heated by the transfer device50(that will be described).

As illustrated inFIG.1A, the supply reel31is formed of a resin or the like and includes a supply shaft portion31A around which the foil film F is wound. The take-up reel35is formed of a resin or the like and includes a take-up shaft portion35A around which the foil film F is taken up. A load apply mechanism, not illustrated, is provided for the supply reel31. The load apply mechanism generates a frictional force between the supply reel31and a supply case32that rotatably supports the supply reel31, thereby applying a load torque to the supply reel31. The load torque is applied to the supply reel31, so that the foil film F is tensioned when taken up by the take-up reel35.

For convenience sake,FIG.1A, etc., illustrate a state in which the foil film F is wound around both the supply reel31and the take-up reel35to a maximum extent. Actually, in a new condition of the film unit FU, the diameter of the roll-like foil film F wound around the supply reel31is maximum while the foil film F is not wound around the take-up reel35or the diameter of the roll-like foil film F wound around the take-up reel35is minimum. On the other hand, when the film unit FU reaches the end of its life, namely, when the foil film F is used up, the diameter of the roll-like foil film F wound around the take-up reel35is maximum while the foil film F is not wound around the supply reel31or the diameter of the roll-like foil film F wound around the supply reel31is minimum.

Each of the first guide shaft41, the second guide shaft42, and the third guide shaft43is a shaft shaped like a roller for changing a moving direction of the foil film F. The first guide shaft41, the second guide shaft42, and the third guide shaft43are formed of SUS (stainless steel), for instance.

The first guide shaft41is located upstream of the transfer device50in the conveying direction of the sheet S. The first guide shaft41changes the moving direction of the foil film F drawn from the supply reel31so as to be substantially parallel with the conveying direction of the sheet S.

The foil film F guided by the first guide shaft41is conveyed toward the transfer device50in a state in which the supported layer F2(FIG.1B) faces upward. The sheet S is superposed on the foil film F whose supported layer F2faces upward, and the sheet S is then conveyed with the foil film F toward the transfer device50.

The second guide shaft42is located downstream of the transfer device50in the conveying direction of the sheet S. The second guide shaft42changes the moving direction of the foil film F that has passed the transfer device50to a direction different from the conveying direction of the sheet S, thus permitting the foil film F to be peeled off from the sheet S.

The third guide shaft43is a member for defining the moving direction of the foil film F that is changed by the second guide shaft42. Specifically, the third guide shaft43defines an angle of the foil film F when the foil film F is peeled off from the sheet S. (This angle will be hereinafter referred to as “separating angle” where appropriate.) Here, the separating angle is an angle formed by: a portion of the foil film F tensioned between the first guide shaft41and the second guide shaft42; and a portion of the foil film F tensioned between the second guide shaft42and the third guide shaft43. The third guide shaft43changes the moving direction of the foil film F guided by the second guide shaft42to thereby guide the foil film F to the take-up reel35.

In a state in which the film unit FU is mounted on the foil transfer apparatus1, the take-up reel35is driven and rotated counterclockwise inFIG.1by a motor80provided in the housing2. When the take-up reel35rotates, the foil film F wound around the supply reel31is drawn. The foil film F drawn from the supply reel31is guided by the guide shafts41-43and is taken up around the take-up reel35. Specifically, in a foil transfer operation, the foil film F is sent by a pressure roller51and a heating roller61(both of which will be described), so that the foil film F is drawn from the supply reel31. The foil film F that has been sent by the pressure roller51and the heating roller61is taken up around the take-up reel35.

The transfer device50is configured to transfer the transfer layer F22onto the toner image formed on the sheet S by heating and pressurizing the sheet S and the foil film F that are superposed on each other. The transfer device50includes the pressure roller51(as one example of a pressurizing member) and the heating roller61(as one example of a heating member). The transfer device50heats and pressurizes the sheet S and the foil film F superposed on each other at a nip position between the pressure roller51and the heating roller61.

The pressure roller51is a roller formed by covering the circumferential surface of a cylindrical core metal with a rubber layer formed of silicone rubber. The pressure roller51is disposed so as to be located on an upper side of the foil film F and is capable of contacting the back surface of the sheet S, i.e., the surface of the sheet S opposite to the front surface thereof on which the toner image is formed.

The pressure roller51is rotatably supported at opposite ends thereof by the cover22. The pressure roller51cooperates with the heating roller61to nip the sheet S and the foil film F therebetween. The pressure roller51is driven and rotated by the motor80so as to rotate the heating roller61.

The heating roller61is a roller constituted by a cylindrical metal pipe in which is disposed a heater. The heating roller61heats the foil film F and the sheet S. The heating roller61is disposed so as to be located on a lower side of the foil film F and is capable of contacting the foil film F. The heating roller61heats the foil film F and the sheet S. In the following explanation, a direction in which an axis, about which the heating roller61rotates, extends will be simply referred to as “axial direction”.

The heating roller61is supported by a heating unit6so as to be rotatable and movable in the up-down direction. The heating unit6includes a roller-position change mechanism7configured to cause the heating roller61to come into contact with and move away from the foil film F. The heating unit6is disposed between the supply reel31and the take-up reel35in the conveying direction of the sheet S. In a state in which the cover22is closed, the roller-position change mechanism7causes the heating roller61to be moved to a contact position at which the heating roller61contacts the foil film F, at timing when the sheet S is supplied to the transfer device50. In a case where the cover22is opened or in a case where the foil transfer operation is not performed on the sheet S by the transfer device50, the roller-position change mechanism7causes the heating roller61to be kept located at a spaced position at which the heating roller61is spaced apart from the foil film F.

In the thus constructed foil transfer apparatus1, the sheet S placed on the sheet tray3with the front surface thereof facing downward is conveyed by the sheet supply mechanism11toward the transfer device50The sheet S is superposed on the foil film F supplied from the supply reel31on the upstream side of the transfer device50in the conveying direction and is then conveyed to the transfer device50in a state in which the toner image of the sheet S and the foil film F are in contact with each other.

In the transfer device50, when the sheet S and the foil film F pass the nip position between the pressure roller51and the heating roller61, the sheet S and the foil film F are heated and pressurized by the heating roller61and the pressure roller51, so that the foil (the supported layer F2) is transferred onto the toner image.

After the foil has been transferred, the sheet S and the foil film F are conveyed to the second guide shaft42in a state in which the sheet S and the foil film F are stuck to each other. When the sheet S and the foil film F pass the second guide shaft42, the moving direction of the foil film F is changed to a direction different from the conveying direction of the sheet S, so that the foil film F is peeled off from the sheet S, namely, the supported layer F2bonded to the toner image is peeled off from the supporting layer F1of the foil film F.

The foil film F peeled off from the sheet S and including the supporting layer F1that is peeled off from the supported layer F2bonded to the toner image on the sheet S is taken up around the take-up reel35. On the other hand, the sheet S from which the foil film F is peeled off is discharged by the sheet discharge mechanism12to outside the housing2in a state in which the front surface of the sheet S on which the foil has been transferred faces downward.

There will be next explained in detail the characterizing feature of the present embodiment, i.e., the roller-position change mechanism7of the heating unit6.

As illustrated inFIGS.3and4, the heating unit6includes a fixed frame60in addition to the heating roller61and the roller-position change mechanism7described above. The fixed frame60constitutes an outer frame of the heating unit6and supports the roller-position change mechanism7. The fixed frame60is fixed to the housing body21.

The roller-position change mechanism7is configured to move the heating roller61between the contact position illustrated inFIG.3and the spaced position illustrated inFIG.4. In other words, the heating roller61is moved by the roller-position change mechanism7in a direction in which the heating roller61and the pressure roller51are arranged (FIG.1). In the following explanation, the direction in which the heating roller61moves will be simply referred to as “movement direction”.

As illustrated inFIG.5, the roller-position change mechanism7includes a movable frame70and cams73. The movable frame70supports the heating roller61. The movable frame70is slidably guided by a guide portion (not illustrated) of the fixed frame60so as to be movable between a first position illustrated inFIG.6and a second position illustrated inFIG.7. As illustrated inFIG.6, the first position is a position at which the heating roller61is in contact with the foil film F in a state in which the foil film F is mounted on the housing body21. As illustrated inFIG.7, the second position is a position at which the heating roller61is spaced apart from the foil film F in the state in which the foil film F is mounted on the housing body21. It is noted that the direction in which the movable frame70moves between the first position and the second position is the same as the movement direction indicated above.

Each of the cams73is configured to move the movable frame70. The cams73are disposed respectively at opposite end portions of a shaft73S that extends in the axial direction. The shaft73S is configured to be rotated by a drive source not illustrated. The rotation of the shaft73S causes each cam73to be displaceable between a pushing position (FIG.6) at which the cam73pushes the movable frame70and a release position (FIG.7) at which the cam73does not push the movable frame70.

When each cam73rotates from the release position to the pushing position, the movable frame70is pushed by each cam73and is moved from the second position to the first position. In a state in which the movable frame70is located at the first position, the heating roller61is located at the contact position.

When each cam73rotates from the pushing position to the release position, the movable frame70is not pushed by each cam73and is moved from the first position to the second position. In the present embodiment, when the cams73rotate to the respective release positions, the movable frame70moves from the first position to the second position by its own weight. In a state in which the movable frame70is located at the second position, the heating roller61is located at the spaced position.

As illustrated inFIG.6, the movable frame70of the present embodiment is constituted by two frames arranged in the up-down direction. Specifically, the movable frame70includes a first frame71and a second frame72. The roller-position change mechanism7further includes a connecting shaft74, rollers75, and springs76.

As illustrated inFIG.5, the connecting shaft74is a shaft extending in the axial direction and connects the first frame71and the second frame72.

The rollers75are disposed respectively at opposite end portions of the connecting shaft74in the axial direction and are rotatable relative to the connecting shaft74. Each roller75is a member configured to be pushed by the corresponding cam73. When the rollers75are pushed by the corresponding cams73, the connecting shaft74is moved with the rollers75.

The first frame71is located above the second frame72. The first frame71includes a support portion71A, connecting portions71B, spring engaging portions71C, and protrusions71D (FIG.8).

The support portion71A is a portion for supporting the heating roller61. The connecting portions71B are portions for connecting the first frame71to the second frame72via the connecting shaft74. Each connecting portion71B has an elongate hole71H in which the connecting shaft74is engaged. The elongate hole71H is a long hole extending in the movement direction. Accordingly, the first frame71is slidably movable relative to the connecting shaft74in the movement direction. As illustrated inFIG.8, each of the spring engaging portions71C protrudes toward the second frame72. Each spring engaging portion71C is a portion that is in engagement with one of opposite ends of the corresponding spring76. Each of the protrusions71D protrudes toward one side in the axial direction. The protrusion71D is a portion that pushes a corresponding one of links64(that will be described) when the first frame71moves from the second position to the first position.

The second frame72includes connecting portions72A, spring engaging portions72B, and a protrusion72C.

Each of the connecting portions72A is a portion that engages with the connecting shaft74for connecting the second frame72to the first frame71via the connecting shaft74. Each connecting portion72A has a cutout72K in which the connecting shaft74is engaged from the lower side. Accordingly, the second frame72is slidably movable relative to the connecting shaft74in the movement direction. Each spring engaging portion72B protrudes toward the first frame71. Each spring engaging portion72B is a portion that is in engagement with the other of the opposite ends of the corresponding spring76. The protrusion72C extends in the movement direction. In the present embodiment, the protrusion72C is located at a lower end of the second frame72so as to extend downward. The protrusion72C is a portion utilized in detecting the position of the movable frame70by a sensor SA that will be described.

As illustrated inFIG.6, the springs76are disposed between the first frame71and the second frame72. Each spring76is one example of an elastically support member, in other words, an urging member. In the present embodiment, each spring76is a compression spring, and a plurality of springs76are provided in the present foil transfer apparatus1. The first frame71and the second frame72are slidably movable relative to the connecting shaft74in the movement direction and are urged by the springs76in a direction in which the first frame71and the second frame72are spaced apart from each other.

When the cams73rotate from the respective release positions to the respective pushing positions, the cams73push up the corresponding rollers75, so that the connecting shaft74is pushed up and the connecting shaft74accordingly pushes the connecting portions72A of the second frame72. Thus, the connecting shaft74moves the second frame72upward. When the second frame72moves upward, the first frame71is pushed upward via the springs76. Thus, the first frame71and the second frame72are moved from the second position to the first position.

As illustrated inFIG.7, when the cams73rotate from the respective pushing positions to the respective release positions, the cams73do not push up the corresponding rollers75. Because the connecting shaft74does not push the second frame72in this state, the springs76urge the first frame71and the second frame72in the direction in which the first frame71and the second frame72are spaced apart from each other, so that the first frame71and the second frame72move away from each other. The connecting shaft74then comes into contact with a lower end of each elongate hole71H of the first frame71, and the first frame71and the second frame72no longer move away from each other. The first frame71and the second frame72move from the first position to the second position by their own weights.

As illustrated inFIGS.8and9, the heating unit6further includes the sensor SA, a shutter62, and link mechanisms63.

The sensor SA is fixed to the fixed frame60. The sensor SA is an optical sensor configured to detect the position of the movable frame70. The sensor SA detects the position of the protrusion72C to thereby detect the position of the movable frame70. The sensor SA is connected to the controller100(FIG.5).

Specifically, the sensor SA includes a light emitting portion SA1and a light receiving portion SA2that is opposed to the light emitting portion SA1.

As illustrated inFIG.6, when the movable frame70is located at the first position, the protrusion72C is not located between the light emitting portion SA1and the light receiving portion SA2. In this case, the light receiving portion SA2detects light emitted from the light emitting portion SA1. Accordingly, the controller100determines that the movable frame70is located at the first position.

As illustrated inFIG.7, when the movable frame70is located at the second position, the protrusion72C is located between the light emitting portion SA1and the light receiving portion SA2. In this case, the light receiving portion SA2does not detect light emitted from the light emitting portion SA1. Accordingly, the controller100determines that the movable frame70is located at the second position.

The shutter62is provided at an upper end portion of the heating unit6so as to be slidably movable between a closed position and an open position. When the shutter62is moved, it is guided by the fixed frame60. The shutter62includes a shaft62S that extends in the axial direction. The shaft62S is in engagement with the link mechanisms63.

As illustrated inFIG.3, when the heating roller61is located at the contact position, the shutter62is located at the open position (as a second shutter position) that is a position different from a position between the heating roller61and the pressure roller51.

As illustrated inFIG.4, when the heating roller61is located at the spaced position, the shutter62is located at the closed position (as a first shutter position) that is the position between the pressure roller51and the heating roller61to cover the heating roller61.

Each of the link mechanisms63is a mechanism for moving the shutter62in conjunction with the movement of the movable frame70. Specifically, as illustrated inFIG.9, when the movable frame70is moved from the first position to the second position, the link mechanisms63cause the shutter62to be moved from the open position to the closed position. As illustrated inFIG.8, when the movable frame70is moved from the second position to the first position, the link mechanisms63cause the shutter62to be moved from the closed position to the open position.

Each link mechanism63includes the link64and a shutter guide65. The following explanation will be made focusing on one of the link mechanisms63.

The link64is swingably supported by the fixed frame60. That is, the link64is swingably supported by the housing body21via the fixed frame60. The link64is swingable between a third position illustrated inFIG.8and a fourth position illustrated inFIG.9. The link64has a shaft64A, an arm64B, and an elongate hole64H. The link64is always urged by a torsion spring (not illustrated) toward the fourth position, namely, in a direction in which the shutter62is closed.

The shaft64A is supported by the fixed frame60. The link64swings about the axis of the shaft64A. The arm64B is a portion that is in contact with the corresponding protrusion71D of the first frame71. The shaft62S of the shutter62is engaged in the elongate hole64H.

The shutter guide65is fixed to the fixed frame60and has an elongate hole65H. The elongate hole65H guides the movement of the shaft62S of the shutter62.

As illustrated inFIG.8, when the movable frame70moves from the second position to the first position, the protrusion71D pushes up the arm64B, and the link64swings from the fourth position to the third position. The link64then moves the shaft62S that is engaged in the elongate hole64H, whereby the shutter62is moved from the closed position to the open position.

As illustrated inFIG.9, when the movable frame70moves from the first position to the second position, the protrusion71D does not push up the arm64B, and the link64swings from the third position to the fourth position by the torsion spring. The link64then moves the shaft62S that is engaged in the elongate hole64H, whereby the shutter62is moved from the open position to the closed position.

As described above, the link64is in engagement with the movable frame70and the shutter62. The link64swings when the movable frame70moves from the second position to the first position, so as to move the shutter62from the closed position to the open position.

Referring toFIG.10, there will be explained a thermistor66provided in the heating unit6. As illustrated inFIG.10, the heating unit6further includes the thermistor66and a metal plate67that extends in the axial direction.

The thermistor66is a temperature sensor for estimating the temperature of the shutter62. The thermistor66is connected to the controller100.

Specifically, the thermistor66is not in contact with the shutter62that is formed of a resin but is disposed so as to be in contact with the metal plate67. The metal plate67extends in the axial direction and has a dimension in the axial direction that is larger than a maximum width of the sheet S on which the foil transfer apparatus1performs the foil transfer operation. It is noted that a distance between the heating roller61and the thermistor66and a distance between the heating roller61and the shutter62are substantially the same.

In the present embodiment, in a case where the temperature detected by the thermistor66is higher than a predetermined temperature, the controller100activates an interlock switch (not illustrated) to prohibit the cover22from being opened.

The configuration according to the illustrated embodiment enjoys the following advantages.

In the foil transfer apparatus including the heating roller61that is movable between the contact position at which the heating roller61is in contact with the foil film F and the spaced position at which the heating roller61is spaced apart from the foil film F, the heating roller61fails to move in some cases even though the cams move. In such a case, even if the sensor detects the phase of the cams that move the heating roller61, the position of the heating roller61cannot be accurately detected.

In the foil transfer apparatus1according to the present embodiment, the sensor SA detects the position of the movable frame70supporting the heating roller61, so that the position of the heating roller61can be accurately detected.

The movable frame70supporting the heating roller61moves from the second position to the first position by being pushed by the cams73and moves from the first position to the second position by its own weight. This configuration eliminates a member for moving the movable frame70from the first position to the second position, resulting in a reduction of the number of components.

The foil transfer apparatus1includes the link mechanisms63each configured to move the shutter62to the first shutter position between the heating roller61and the pressure roller51when the movable frame70moves from the first position to the second position and to move the shutter62to the second shutter position different from the position between the heating roller61and the pressure roller51when the movable frame70moves from the second position to the first position. With this configuration, the link mechanisms63cause the shutter62to cover the heating roller61when the movable frame70moves to the second position, and the shutter62does not hinder nipping by the heating roller61and the pressure roller51when the movable frame70moves to the first position.

The heating unit6includes the first frame71supporting the heating roller61, the second frame72configured to be pushed by the cams73, and the springs76disposed between the first frame71and the second frame72. With this configuration, the second frame72pushed by the cams73pushes the first frame71via the springs76, thus preventing the heating roller61from being pushed more than needed.

In a case where the sheets S used in the foil transfer apparatus1have various sizes and the area over which the sheet S is conveyed differs among the sheets S, there may be generated imbalances in the temperature distribution of the shutter62in the axial direction. In the present embodiment, the thermistor66detects the temperature of the metal plate67that is good in heat conductivity, so that the temperature of the shutter62is estimated. With this configuration, the temperature of the shutter62can be appropriately estimated without providing a plurality of thermistors.

It is to be understood that the present disclosure is not limited to the details of the illustrated embodiment but may be embodied in various forms described below, for instance.

In the illustrated embodiment, the movable frame70moves from the second position to the first position by being pushed by the cam73. The present disclosure is not limited to this configuration. The movable frame70may move from the second position to the first position by being pushed by other member such as a solenoid actuator.

In the illustrated embodiment, the movable frame70moves from the first position to the second position by its own weight. The present disclosure is not limited to this configuration. The movable frame70may move from the first position to the second position by an urging member such as a spring.

In the illustrated embodiment, the movable frame supporting the heating roller61is constituted by the two frames. The movable frame may be constituted by a single frame or at least three frames.

In the illustrated embodiment, the springs76, each as one example of the elastically support member (the urging member), disposed between the first frame71and the second frame72are the compression springs. The elastically support members may be other springs such as leaf springs or torsion springs or may be rubber or sponge.

In the illustrated embodiment, the pressure roller51is illustrated as the pressurizing member, and the heating roller61is illustrated as the heating member. The present disclosure is not limited to this configuration. For instance, the pressurizing member may be a pad or the like that cooperates with the heating roller to nip the sheet and the foil film therebetween. The heating member may be a plate-like member that cooperates with the pressure roller to nip the sheet and the foil film therebetween.

In the illustrated embodiment, the second guide shaft42shaped like a roller is illustrated as the separating member. The present disclosure is not limited to this configuration. The separating member may be a blade shaped like a plate, for instance.

In the illustrated embodiment, the third guide shaft43shaped like a roller is illustrated as the angle defining member. The present disclosure is not limited to this configuration. The angle defining member may be a blade shaped like a plate, for instance.

In the illustrated embodiment, the supply reel31and the take-up reel35constitute a foil-transfer film cartridge FC. The present disclosure is not limited to this configuration. For instance, the foil-transfer film cartridge may include the supply reel, and the take-up reel may be provided in the housing.

In the illustrated embodiment, the foil transfer apparatus is configured to transfer the foil onto the toner image formed on the sheet. The present disclosure is not limited to this configuration. The foil transfer apparatus may be any apparatus provided that the apparatus is configured to transfer the foil to the sheet.

In the illustrated embodiment, the foil film F is constituted by the four layers. The present disclosure is not limited to this configuration. The number of layers that constitute the foil film may be optional provided that the foil film includes the transfer layer and the supporting layer.

In the illustrated embodiment, the film unit is constituted by the foil-transfer film cartridge and a holder holding the foil-transfer film cartridge. The present disclosure is not limited to this configuration. The film unit need not necessarily include the holder. The holder may undetachably support the foil-transfer film cartridge.

The transfer device50in the illustrated embodiment includes the pressure roller51and the heating roller61, and the sheet S and the foil film F are superposed on each other at the nip position between the pressure roller51and the heating roller61. There may be employable what is called film fixation in which the sheet passes between the pressure roller and a heated fixation film. Further, a nip position may be defined between the pressure roller and a heater, and a belt may be interposed between the pressure roller and the heater. The sheet placed on the belt may pass the thus defined nip position.

In the illustrated embodiment, the heating roller61is configured to be movable. The pressure roll51may be configured to be movable.

The present disclosure may be embodied by optionally combining the elements described in the embodiment and the modifications.