JP2015136805A - image transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image transfer device capable of suppressing vibration along a conveying direction of a sheet in a transfer head.SOLUTION: An image transfer device includes: a conveying mechanism for conveying a transfer sheet 31 and an image receiving sheet 32 along a conveying direction in a state that the transfer sheet 31 and the image receiving sheet 32 face to each other; a transfer head 23 for heating the transfer sheet 31 and the image receiving sheet 32 conveyed by the conveying mechanism and transferring images possessed by the transfer sheet 31 to the image receiving sheet 32; an energization member 25 for pressing the transfer head 23 against the transfer sheet 31 and the image receiving sheet 32 conveyed by the conveying mechanism in a state that the transfer head 23 can move along the conveying direction and moving the transfer head 23 along a direction opposite to the conveying direction when the movement distance of the transfer head 23 exceeds a prescribed distance; and a vibration control mechanism located side by side with the transfer head 23 in the conveying direction so as to suppress vibration along the conveying direction in which the movement in the conveying direction and the movement in the opposite direction in the transfer head 23 are repeated.

Description

  The technology of the present disclosure relates to an image transfer apparatus that transfers an image to a transfer target.

  As an apparatus for transferring an image to a transfer medium such as a passport, an image transfer apparatus using an intermediate transfer system is widely used as described in Patent Document 1, for example. In the image transfer apparatus, before the image is transferred to the transfer target, the image of the transfer sheet is transferred onto an image receiving sheet different from the transfer target, and a predetermined image is formed on the image receiving sheet. Then, the image on the image receiving sheet is transferred to the transfer body, whereby a predetermined image is formed on the transfer body.

  In such an image transfer apparatus, two sheets are conveyed along a conveyance direction, which is one direction, with the image receiving sheet and the transfer sheet facing each other. Then, the transfer head that comes into contact with one of the two conveyed sheets heats the transfer sheet, whereby the image on the transfer sheet is transferred to the image receiving sheet.

JP 2011-230390 A

  By the way, the transfer head is pressed with a predetermined force by the urging member against the two sheets being conveyed in a state where the transfer head can be moved in the conveyance direction. At this time, as the two sheets move along the conveyance direction, the transfer head also moves along the conveyance direction from the initial position. When the distance traveled by the transfer head exceeds a predetermined size, the transfer head approaches the initial position along the direction opposite to the transport direction by the restoring force of the biasing member. As a result, while the image is transferred from the transfer sheet to the image receiving sheet, the movement of the transfer head along the conveyance direction and the movement of the transfer head along the direction opposite to the conveyance direction are alternately repeated.

  An object of the technology of the present disclosure is to provide an image transfer apparatus capable of suppressing vibration along a sheet conveyance direction in a transfer head.

  One aspect of the image transfer apparatus according to the technology of the present disclosure includes a transport mechanism that transports the transfer sheet and the image receiving sheet along a transport direction in a state where the transfer sheet and the image receiving sheet face each other, and the transport mechanism transports the transfer sheet and the image receiving sheet. A transfer head that heats the transfer sheet and the image receiving sheet, and transfers an image of the transfer sheet to the image receiving sheet; and the transfer mechanism is movable in the transfer direction. When the transfer head is pressed against the transfer sheet and the image receiving sheet being conveyed, and when the transfer head moves beyond a predetermined distance, the direction is opposite to the conveyance direction. An urging member for moving the transfer head; and a movement in the transport direction of the transfer head, positioned alongside the transfer head in the transport direction; Comprising a damping mechanism to suppress the repetitive vibration along said conveying direction is a movement in the Kigyaku direction.

  According to one aspect of the image transfer device in the technology of the present disclosure, the vibration control mechanism prevents the transfer head from moving along the direction parallel to the transport direction, and thus the transfer head may vibrate along the transport direction. It can be suppressed.

  In another aspect of the image transfer apparatus according to the technology of the present disclosure, the vibration suppression mechanism includes a connection unit connected to the transfer head, and a vibration control unit connected to the transfer head via the connection unit, It is preferable that the connection portion has flexibility to bend by receiving a force from the transfer head along a direction opposite to the transport direction.

  According to another aspect of the image transfer device according to the technique of the present disclosure, since the connecting portion is flexible, the movement of the transfer head when the biasing member moves the transfer head along the direction opposite to the transport direction. Is less likely to be disturbed. Therefore, it is possible to prevent the transfer head that has been moved along the conveyance direction by the movement of the two sheets from becoming difficult to return to the initial position.

  In another aspect of the image transfer device according to the technique of the present disclosure, the transfer head extends along a width direction that is a direction intersecting the transport direction, and the connection portion is in the width direction with respect to the transfer head. It is preferable to connect at a plurality of connection positions.

  According to the other aspect of the image transfer apparatus in the technology of the present disclosure, the effect of suppressing the vibration of the transfer head by the vibration damping mechanism compared to the configuration in which the connection portion is connected to the transfer head at one connection position, Unbiased in the width direction is suppressed. Therefore, the inclination of the transfer head with respect to the transport direction can be suppressed from becoming larger than when the transfer head is located at the initial position.

  In another aspect of the image transfer apparatus according to the technology of the present disclosure, the transfer head extends along a width direction that is a direction intersecting the transport direction, and the connection portion extends in the width direction with respect to the transfer head. It is preferable to connect at one connection position located in the center.

  According to another aspect of the image transfer device according to the technology of the present disclosure, the vibration of the transfer head by the vibration damping mechanism is reduced compared to the configuration in which the connection portion is connected at the connection position located at the end in the width direction of the transfer head. The suppressing effect is easily transmitted to the entire width direction of the transfer head.

  In another aspect of the image transfer apparatus according to the technology of the present disclosure, the transfer head repeats transfer at a predetermined control cycle, and the vibration control mechanism vibrates the vibration of the transfer head at a cycle different from the control cycle. Is preferably suppressed.

In another aspect of the image transfer apparatus according to the technique of the present disclosure, image unevenness due to vibration of the transfer head can be more effectively suppressed.
In another aspect of the image transfer apparatus according to the technology of the present disclosure, it is preferable that the vibration damping mechanism includes a damper that dampens the transfer head by the flow of a viscous fluid.

According to another aspect of the image transfer device of the technology of the present disclosure, the vibration of the transfer head is appropriately suppressed by the damper provided in the vibration damping mechanism.
In another aspect of the image transfer apparatus according to the technology of the present disclosure, it is preferable that the vibration damping mechanism includes a spring that dampens the transfer head by a restoring force.

  According to another aspect of the image transfer device in the technology of the present disclosure, the vibration of the transfer head is appropriately suppressed by the spring provided in the vibration suppression mechanism.

  According to the image transfer device of the present disclosure, it is possible to suppress vibration along the sheet conveyance direction in the transfer head.

It is a block diagram which shows the whole structure of one Embodiment of the image transfer apparatus of this indication with an external arithmetic unit. It is a side view which shows the side structure of the transfer mechanism with which an image transfer apparatus is provided. It is sectional drawing which shows the cross-sectional structure of the image receiving sheet used with an image transfer apparatus. It is sectional drawing which shows the cross-section of the transfer sheet used with an image transfer apparatus. It is a figure which shows the state by which the image was transcribe | transferred from the transfer sheet to the image receiving sheet. FIG. 5 is a top view of an example of connection between a transfer head and a vibration damping mechanism as viewed from above. FIG. 5 is a top view of an example of connection between a transfer head and a vibration damping mechanism as viewed from above. FIG. 5 is a top view of an example of connection between a transfer head and a vibration damping mechanism as viewed from above. It is a side view which shows the side structure of the partial structure of the conventional image transfer apparatus. It is a figure for demonstrating the vibration which arises in a transfer head. 6 is a graph showing the relationship between the amplitude of vibration in the transfer head and time.

  With reference to FIGS. 1 to 11, an embodiment of the image transfer apparatus of the present disclosure will be described. Hereinafter, the overall configuration of the image transfer device, the configuration of the transfer mechanism, the configuration of each of the transfer sheet and the image receiving sheet, the vibration control mechanism, and the operation of the image transfer device will be described in order.

[Overall configuration of image transfer device]
The overall configuration of the image transfer apparatus will be described with reference to FIG.
As shown in FIG. 1, the image transfer device 10 is connected to an external arithmetic device E, and the external arithmetic device E generates image data for the image transfer device 10 to transfer to the transfer target, and the image transfer device 10 to send. The external arithmetic unit E may perform various correction processes on the data corresponding to the transfer source image P when generating the image data so that the image transfer apparatus 10 can easily perform the transfer.

  The external arithmetic unit E divides the two-dimensional image data into one-dimensional image data PD, which is data for each row, so that the change of the format of the image data can be easily handled, and converts the plurality of image data PD into an image. Serial transfer to the transfer device 10. The image transfer device 10 generates a control signal for controlling the drive of the transfer head for each one-dimensional image data PD transmitted from the external arithmetic device E. Then, the image transfer apparatus 10 causes the heat generating portion of the transfer head to generate heat according to the control signal. As a result, the transfer head transfers the image of the transfer sheet to the image receiving layer of the image receiving sheet, and transfers the image based on one image data PD. The transfer head transfers the image corresponding to the entire two-dimensional image P to the image receiving sheet by repeatedly performing the same processing based on each of the image data PD sequentially transmitted from the external arithmetic unit E. The image transfer device 10 transfers the image transferred to the image receiving sheet to a transfer target such as a passport by the next transfer process.

  Note that, in a method of forming an image directly on a transfer target, such as an inkjet method, the image is formed on the transfer target due to unevenness of the surface of the transfer target, ink absorbability, or the like. The image quality will change. On the other hand, according to the above-described image transfer apparatus 10 of the intermediate transfer system, an image once formed on an image receiving sheet different from the transfer target is transferred from the image receiving sheet to the transfer target. Therefore, the image quality of the image formed on the transfer body is hardly affected by the state of the surface of the transfer body, and as a result, an image having higher image quality can be formed on the transfer body.

[Configuration of transfer mechanism]
The configuration of the transfer mechanism provided in the image transfer apparatus will be described with reference to FIG.
As shown in FIG. 2, the transfer mechanism 20 includes a transfer stage 21 and two transfer-side rollers 22, and the transfer mechanism 20 is transferred to the transfer target by the transfer stage 21 and the transfer-side roller 22. The transfer sheet 31 having an image is conveyed.

  The transfer stage 21 has a cylindrical shape extending along the width direction, which is one direction, and each of the two end portions of the transfer stage 21 is in a state where the transfer stage 21 can rotate about the central axis. It is supported by the housing of the apparatus 10 or the like. The transfer stage 21 is connected to, for example, a motor that rotates the transfer stage 21, and rotates around the central axis as the motor rotates. The transfer stage 21 conveys the transfer sheet 31 along the conveyance direction that is substantially tangential to the transfer stage 21 by the rotation of the transfer stage 21.

  Each of the two transfer-side rollers 22 has a cylindrical shape extending along the width direction, like the transfer stage 21, and the diameter of each transfer-side roller 22 is smaller than the diameter of the transfer stage 21, for example. In each transfer-side roller 22, each of the two end portions is supported by a housing or the like of the image transfer apparatus 10 in a state where the transfer-side roller 22 can rotate around the central axis. The two transfer-side rollers 22 are positioned on opposite sides of the transfer stage 21 in the transport direction. Each of the two transfer-side rollers 22 rotates around the central axis as the transfer sheet 31 contacting the outer peripheral surface of each transfer-side roller 22 is transported in the transport direction, for example.

The transfer sheet 31 conveyed by the transfer stage 21 and each transfer roller 22 has a band shape extending along the conveyance direction.
The transfer mechanism 20 further includes a transfer head 23, a plurality of image receiving rollers 26, and a vibration damping unit 27. The transfer mechanism 20 transfers the image of the transfer sheet 31 by the plurality of image receiving rollers 26. The image receiving sheet 32 is conveyed along the conveyance direction.

  The transfer head 23 overlaps the transfer stage 21 in the transport direction. The transfer head 23 has a substantially rectangular plate shape extending along the width direction. Among the surfaces of the transfer head 23, an image receiving sheet 32, an image receiving sheet 32, and a heat generating surface that is a surface facing the transfer stage 21. A heating unit 24 for heating the overlapping transfer sheets 31 is located. The heat generating part 24 is composed of a plurality of heat generating elements, and the plurality of heat generating elements are arranged along the width direction and the conveying direction on the heat generating surface.

  The heat generating unit 24 is heated by supplying energy according to the image data PD transferred from the external computing device E to the image transfer device 10. For example, in the heating unit 24, energy is supplied only to some of the plurality of heating elements according to the image data PD, or the sizes of parts of the plurality of heating elements and the remaining parts are different from each other. Energy is supplied. For example, the control unit included in the image transfer apparatus 10 controls the amount of energy supplied to the heat generating unit 24 by the control signal.

  The transfer head 23 is connected to the housing of the image transfer apparatus 10 via a biasing member 25 such as a spring, for example, and the biasing member 25 biases the transfer head 23 in the extending direction of the biasing member 25. The member 25 is urged in the direction from the connection destination of the member 25 toward the transfer stage 21. As a result, the heat generation surface of the transfer head 23 and the outer peripheral surface of the transfer stage 21 are in close contact with each other, so that the uniformity in image transfer from the transfer sheet 31 to the image receiving sheet 32 is enhanced.

  The urging force applied to the transfer head 23 by the urging member 25 is large enough to enable transfer of an image from the transfer sheet 31 to the image receiving sheet 32. The urging force applied by the urging member 25 to the transfer head 23 is large enough to allow the transfer head 23 to move along the conveyance direction as the image receiving sheet 32 is conveyed. In addition, the transfer head 23 moved along the transport direction is pulled back along the opposite direction opposite to the transport direction. In other words, the urging member 25 allows the transfer head 23 that is pulled along the transport direction to move along the transport direction, while providing a restoring force for returning the position of the transfer head 23 that has moved along the transport direction. Have.

  In the configuration in which the position of the transfer head 23 with respect to the transfer stage 21 is fixed, each of the transfer stage 21 and the transfer head 23 is in order for the outer peripheral surface of the transfer stage 21 and the heat generating surface of the transfer head 23 to be in close contact with each other. The position accuracy with respect to the image transfer apparatus 10 needs to be high. On the other hand, if the transfer head 23 is configured to be connected to the housing of the image transfer apparatus 10 by the urging member 25, the urging force of the urging member 25 causes the heat generation surface of the transfer head 23 to be transferred to the transfer stage 21. Is pressed against the outer peripheral surface with a predetermined force. Therefore, as compared with the configuration in which the position of the transfer head 23 with respect to the transfer stage 21 is fixed, each of the transfer stage 21 and the transfer head 23 can increase the degree of freedom of the position with respect to the image transfer apparatus 10.

  Each of the plurality of image receiving side rollers 26 has a cylindrical shape extending along the width direction, and the diameter of the image receiving side roller 26 is substantially equal to the diameter of the transfer side roller 22, for example. In each image receiving side roller 26, each of the two ends is supported by the housing of the image transfer apparatus 10 in a state where the image receiving side roller 26 can rotate around the central axis. Some of the plurality of image receiving side rollers 26 are located on one side with respect to the transfer head 23 in the transport direction, and the rest of the plurality of image receiving side rollers 26 are located on the other side with respect to the transfer head 23. Each of the plurality of image receiving side rollers 26 rotates about the central axis as the image receiving sheet 32 that contacts the outer peripheral surface of each image receiving side roller 26 is conveyed along the conveying direction.

In the transfer mechanism 20, the transfer stage 21, the transfer side roller 22, and the image receiving side roller 26 are examples of the transport mechanism.
The vibration damping unit 27 is connected to the transfer head 23 by a connecting portion 28 extending along the transport direction, and suppresses vibration along the transport direction in the transfer head 23. The connection portion 28 is connected to one surface extending in the width direction among the surfaces of the transfer head 23. Further, the vibration control unit 27 is connected to, for example, the housing of the image transfer apparatus 10.

  In such an image transfer apparatus 10, when the image on the transfer sheet 31 is transferred to the image receiving sheet 32, the transfer side roller 22 and the transfer stage 21 convey the transfer sheet 31 along the conveyance direction, and at the same time, the image receiving side roller 26. However, the image receiving sheet 32 is conveyed along the conveyance direction. At this time, the transfer stage 21 and the transfer head 23 sandwich the transfer sheet 31 and the image receiving sheet 32 with a predetermined pressure, so that the relative speed of the image receiving sheet 32 with respect to the transfer sheet 31 becomes zero. The image receiving sheet 32 is conveyed.

  In the image transfer apparatus 10, heat is supplied to the transfer sheet 31 being conveyed by supplying energy to the heat generating unit 24 according to the image data PD transferred from the external arithmetic unit E, and the transfer sheet 31 is supplied with heat. Heat is also supplied to the image receiving sheet 32 in contact therewith. As a result, the image of the transfer sheet 31 is transferred to the image receiving sheet 32.

[Configurations of image receiving sheet and transfer sheet]
An example of the configuration of each of the image receiving sheet 32 and the transfer sheet 31 will be described with reference to FIGS.

  As shown in FIG. 3, the image receiving sheet 32 includes an image receiving side substrate 41, an image receiving side peeling layer 42, and an image receiving layer 43. In the image receiving sheet 32, the image receiving side peeling layer 42 is stacked on one surface of the image receiving side substrate 41, and one surface of the image receiving side peeling layer 42 that faces the surface that contacts the image receiving side substrate 41. The image receiving layer 43 is stacked on the surface.

  The image receiving side substrate 41 is, for example, a resin film, and the resin film forming material is preferably a heat-resistant material such as polyethylene terephthalate. The image receiving side peeling layer 42 is a layer that allows the laminate of the image receiving side peeling layer 42 and the image receiving layer 43 to be peeled from the image receiving side substrate 41. The material for forming the image receiving side peeling layer 42 is, for example, thermoplastic. Resin. The image receiving layer 43 is a layer to which a part of the layer of the transfer sheet 31 is adhered, and a material for forming the image receiving layer 43 is, for example, a resin to which a layer constituting the transfer sheet 31 is easily attached.

  As shown in FIG. 4, the transfer sheet 31 includes a transfer side substrate 51, a transfer side release layer 52, an image forming layer 53, and an adhesive layer 54. In the transfer sheet 31, the transfer-side release layer 52 is stacked on one surface of the transfer-side substrate 51, and is one surface of the transfer-side release layer 52 that faces the surface that contacts the transfer-side substrate 51. The image forming layer 53 is stacked on the surface. In the transfer sheet 31, an adhesive layer 54 is stacked on one surface of the image forming layer 53 that faces the surface that contacts the transfer-side release layer 52.

  The transfer side substrate 51 is, for example, a resin film, like the image receiving side substrate 41. The transfer-side release layer 52 is a layer that allows the laminate of the transfer-side release layer 52, the image forming layer 53, and the adhesive layer 54 to be released from the transfer-side substrate 51. It is formed from the same material as the material.

  The image forming layer 53 is a layer for forming an image to be transferred to the transfer target, and the forming material of the image forming layer 53 is, for example, a resin containing a colorant such as ink. Alternatively, the image forming layer 53 is a resin film having a minute uneven structure such as a hologram or a diffraction structure. The image forming layer 53 may have both a portion composed of a resin containing a colorant and a portion composed of a resin film having an uneven structure.

  The adhesive layer 54 adheres the image forming layer 53 to the image receiving layer 43 of the image receiving sheet 32 when the transfer sheet 31 is heated by the transfer head 23, while allowing the transfer side peeling layer 52 and the transfer side substrate 51 to peel off. The material for forming the adhesive layer 54 is, for example, a thermoplastic resin.

  As shown in FIG. 5, in the image transfer apparatus 10, each of the transfer sheet 31 and the image receiving sheet 32 is conveyed with the adhesive layer 54 of the transfer sheet 31 and the image receiving layer 43 of the image receiving sheet 32 facing each other. Then, when the transfer sheet 31 and the image receiving sheet 32 are sandwiched between the transfer head 23 and the transfer stage 21, the adhesive layer 54, the image in the portion of the transfer sheet 31 heated by the heat generating portion 24 of the transfer head 23. The laminated body of the formation layer 53 and the transfer side peeling layer 52 is transferred to the image receiving layer 43.

  Here, elements for expressing colors such as ink are widely used in the image forming layer 53 of the transfer sheet 31 described above. On the other hand, in recent years, an optical element such as a hologram is preferably used for the image forming layer 53 for the purpose of improving the design of the transfer target or the confidentiality of the transfer target. There is also.

  By the way, the transfer sheet 31 provided with the image forming layer 53 having optical elements is expensive, and an image using the optical elements is formed not on the entire transfer target but on the local area of the subject. There are many cases. For this reason, the length of the transfer sheet 31 in the width direction is often smaller than the length of the transfer head 23. On the other hand, the laminate of the image receiving side peeling layer 42 and the image receiving layer 43 included in the image receiving sheet 32 is often large enough to cover the entire transfer target. For this reason, the length of the image receiving sheet 32 in the width direction is often larger than the length of the transfer sheet 31. At this time, the image receiving layer 43 included in the image receiving sheet 32 may be in direct contact with the heat generating surface of the transfer head 23.

  Of the surface of the transfer side substrate 51 that is in contact with the transfer head 23, a surface that faces the surface on which the transfer side peeling layer 52 is stacked is subjected to a process for making the transfer head 23 easily slide relative to the transfer side substrate 51. Is possible. On the other hand, the image receiving layer 43 of the image receiving sheet 32 needs to have a characteristic that facilitates transfer of the adhesive layer 54 of the transfer sheet 31, for example, high adhesion to the adhesive layer 54. Therefore, if a process for making the transfer head 23 slippery with respect to the image receiving layer 43 is performed, the adhesive layer 54 is difficult to be transferred to the image receiving layer 43. It is difficult to perform a process for making it slippery. After all, in the configuration in which the length of the transfer sheet 31 in the width direction is smaller than the length of the transfer head 23, the transfer head 23 is less likely to slip with respect to the image receiving layer 43. It becomes easy to move along the conveyance direction.

  When the distance that the transfer head 23 moves along the transport direction exceeds a predetermined size, the urging member 25 moves the transfer head 23 along the direction opposite to the transport direction, thereby causing the transfer head 23 to move. To the initial position of the transfer head 23. As a result, there is a high possibility that vibration along the transport direction occurs in the transfer head 23. The initial position of the transfer head 23 is the position of the transfer head 23 before the transfer of the image by the transfer mechanism 20 and when the transfer sheet 31 and the image receiving sheet 32 are not conveyed.

[Vibration control mechanism]
With reference to FIGS. 6 to 8, the vibration damping unit 27 provided in the transfer mechanism 20 will be described in more detail.
In general, image transfer by the transfer head 23 is performed based on a control signal having a periodicity of about several hundred Hz. Therefore, for example, when vibration of about several tens of Hz occurs in the transfer head 23, the position of the transfer head 23 relative to the transfer stage 21 moves out of synchronization with the cycle of the control signal, so in the image transferred to the image receiving sheet 32 Varies in the distance between the plurality of transfer positions. As a result, the visibility of the image transferred to the transfer object is lowered. Therefore, the vibration control unit 27 can suppress the variation in the distance between the plurality of transfer positions by suppressing the vibration of the transfer head 23 having a period different from the control period, so that an image with high visibility can be transferred. Formed.

  The vibration damping unit 27 is connected to the transfer head 23 and the housing of the image transfer apparatus 10 and suppresses vibration of the transfer head 23 along the transport direction. The damping unit 27 may be, for example, a mechanism that suppresses vibration of the transfer head 23 using the viscosity of the fluid, or a mechanism that suppresses vibration of the transfer head 23 using friction generated in the damping unit 27. A mechanism having a restoring force for restoring to a predetermined shape may be used.

  When the vibration control unit 27 is a mechanism that suppresses vibration using the viscosity of the fluid, the vibration control unit 27 accommodates, for example, viscous fluids such as various gases and liquids therein, and the transfer head by the flow of the viscous fluid. Any damper can be used. The fluid may be a gas or a liquid, and when the fluid is a liquid, the liquid may be, for example, water or various oils. When the vibration control unit 27 is a mechanism that suppresses vibration using friction, the vibration control unit 27 may be a piston mechanism including, for example, a cylinder and a piston. When the damping unit 27 is a mechanism having a restoring force, the damping unit 27 may be a spring that dampens the transfer head by the restoring force, for example. When the damping unit 27 is a mechanism having a restoring force, the restoring force constant in the damping unit 27 preferably has non-linearity. When the restoring force constant has non-linearity, there are more situations in which the damping unit 27 can suppress vibration generated in the transfer head 23 than when the restoring force constant has linearity.

  The damping unit 27 combines at least two of a mechanism that suppresses vibration using the viscosity of a fluid, a mechanism that suppresses vibration using friction, and a mechanism that suppresses vibration using a restoring force. It may be a configuration.

  The connection unit 28 transmits a force acting on the transfer head 23 along the conveyance direction to the vibration suppression unit 27 to cause the vibration suppression unit 27 to exhibit a vibration suppression function. On the other hand, the connecting portion 28 is flexible enough to prevent the biasing member 25 from moving the transfer head 23 along the direction opposite to the transport direction. Since the connection portion 28 has flexibility, the connection portion 28 can be bent by receiving a force from the transfer head 23 along the direction opposite to the conveyance direction. The connection part 28 is a wire, for example, and when the connection part 28 is a wire, the formation material of a wire should just be various metals, for example.

The vibration control unit 27 and the connection unit 28 constitute a vibration control mechanism in the image transfer apparatus 10. Examples of the connection between the vibration control unit 27, the connection unit 28, and the transfer head 23 include the following modes.
As shown in FIG. 6, for example, the vibration damping unit 27 is connected to a connection surface, which is one surface of the transfer head 23, via the connection unit 28, and the connection unit 28 is connected in the width direction of the connection surface. It is connected to the transfer head 23 at one connection position located at the center. For a certain target, when the position close to the transport source in the transport direction is upstream in the transport direction and the position close to the transport destination is downstream in the transport direction, the vibration damping unit 27 is downstream of the transfer head 23 in the transport direction. Is located.

  Alternatively, as shown in FIG. 7, the vibration damping unit 27 is located upstream of the transfer head 23 in the transport direction. At this time, the connection portion 28 is connected to the transfer head 23 at one connection position located at the center in the width direction of the connection surface. The vibration damping unit 27 can suppress the vibration of the transfer head 23 regardless of whether it is located upstream or downstream of the transfer head 23 in the transport direction.

  In such a transfer mechanism 20, the connection portion 28 is connected to the transfer head 23 at one connection position located at the center in the width direction. Therefore, compared with the configuration in which the connection portion 28 is connected at the connection position located at the end of the transfer head 23 in the width direction, the effect of suppressing the vibration of the transfer head 23 by the vibration control portion 27 is It becomes easy to convey to the whole direction.

  Alternatively, as shown in FIG. 8, the vibration damping unit 27 is located downstream of the transfer head 23 in the transport direction. The connection portion 28 is connected at two connection positions different from each other in the width direction on the connection surface of the transfer head 23, while being connected to the vibration damping portion 27 at one connection position. When the vibration control unit 27 is connected to the transfer head 23 at two connection positions different from each other in the width direction, one of the two connection positions is close to one end of the connection surface of the transfer head 23 in the width direction, and The other is preferably close to the other end of the connecting surface of the transfer head 23 in the width direction.

  If the vibration control unit 27 is connected to the transfer head 23 at two connection positions that are different from each other in the width direction, the transfer head 23 is moved in the width direction from the initial position by the vibration control action of the vibration control unit 27. It is possible to suppress tilting. In addition, as the distance between the two positions where the vibration control unit 27 is connected to the transfer head 23 is larger, the transfer head 23 is further suppressed from being inclined with respect to the width direction than the initial position.

  Even when the connecting portion 28 is connected to the transfer head 23 at two different connection positions in the width direction, the vibration damping portion 27 is not limited to the downstream of the transfer head 23 in the transport direction, and It may be located upstream. In any configuration, the vibration damping unit 27 suppresses vibration of the transfer head 23 when an image is transferred to the image receiving sheet 32.

[Operation of image transfer device]
The operation of the image transfer apparatus 10 will be described with reference to FIGS. In the following, prior to the description of the operation of the image transfer apparatus 10 of the present embodiment, the configuration of the transfer mechanism provided in the conventional image transfer apparatus and the principle of vibration of the transfer head 23 will be described in order. In FIG. 9, the same reference numerals are given to the same components as those of the transfer mechanism 20 described with reference to FIG. 1. FIG. 11 is a graph showing the relationship between the amplitude and time in the vibration of the transfer head, and shows the initial stage of the vibration of the transfer head in the conventional image transfer apparatus and the process in which the vibration is attenuated by the damping function. FIG.

  As shown in FIG. 9, the transfer mechanism 60 included in the conventional image transfer apparatus includes a transfer stage 21 that conveys the transfer sheet 31 and two transfer-side rollers 22, as in the transfer mechanism 20 described above. Similarly to the transfer mechanism 20, the transfer mechanism 60 includes a transfer head 23 that faces the transfer stage 21, an urging member 25 that urges the transfer head 23, and a plurality of image receiving side rollers 26 that convey the image receiving sheet 32. I have. That is, the image transfer apparatus is different from the image transfer apparatus 10 described above in that the image transfer apparatus does not include the vibration control unit 27 and the connection unit 28 that connects the vibration control unit 27 to the transfer head 23.

  Therefore, in such a transfer mechanism 60, when the image is transferred to the image receiving sheet 32, the position of the transfer head 23 with respect to the transfer stage 21 is greatly changed like the transfer head 23A indicated by a two-dot chain line.

  As shown in FIG. 10, when the transfer head 23 of the transfer mechanism 60 is considered to be a weight 71 of the mass M, the weight 71 is connected to, for example, the image transfer apparatus 10 via a spring 72 having a spring constant k. Connected to the chassis. The spring 72 corresponds to the urging member 25 in the transfer mechanism 60.

  The weight 71 can be regarded as being located on a moving body 73 having a belt shape and moving at a constant speed. The moving body 73 corresponds to the image receiving sheet 32 conveyed by the transfer mechanism 60. In the moving body 73, the moving speed is v, the static friction coefficient with the weight 71 is μ0, and the dynamic friction coefficient with the weight 71 is μ1, and the static friction coefficient μ0 is larger than the dynamic friction coefficient μ1.

  Further, the weight 71 is pressed against the moving body 73 by a force 74 along a height direction orthogonal to the moving direction of the moving body 73. The force 74 corresponds to the urging force of the urging member 25 provided in the transfer mechanism 60, and the magnitude of the force is N.

  When the moving body 73 moves at a constant speed, the weight 71 is dragged by a static frictional force with the moving body 73 and moves at a constant speed along the moving direction of the moving body 73. When the weight 71 moves along the moving direction, the spring 72 also extends along the moving direction. When the distance that the spring 72 extends reaches a predetermined distance, the static frictional force between the weight 71 and the moving body 73 and the restoring force of the spring 72 become equal. When the distance that the spring 72 extends until the static frictional force and the restoring force are equal to each other is the distance x0, the distance x0 is expressed by the following Expression 1.

x0 = μ0 · N / k (Formula 1)
When the distance that the spring 72 extends exceeds the distance x0 at which the static friction force and the restoring force become equal, the restoring force of the spring 72 is larger than the static friction force with the moving body 73 in the weight 71. Therefore, the weight 71 is pulled by the restoring force of the spring 72 and moves in the direction opposite to the moving direction of the moving body 73. At this time, immediately after the weight 71 starts moving in the direction opposite to the moving direction, the weight 71 accelerates by the restoring force of the spring 72. While the weight 71 is moving in the direction opposite to the moving direction of the moving body 73, a dynamic friction force is generated between the weight 71 and the moving body 73. Then, after the restoring force of the spring 72 and the dynamic frictional force between the weight 71 and the moving body 73 become equal, the movement of the weight 71 becomes a decelerating movement, and further between the weight 71 and the moving body 73. When the static frictional force exceeds the restoring force of the spring 72, the weight 71 starts to move again along the moving direction of the moving body 73.

  After the moving direction of the weight 71 is reversed, the weight 71 is dragged by a static frictional force with the moving body 73 and moves at a constant speed along the moving direction of the moving body 73. Thus, the weight 71 alternately repeats when moving along the moving direction due to the static frictional force with the moving body 73 and when moving in the direction opposite to the moving direction due to the restoring force of the spring 72. In the weight 71, vibration is generated.

  That is, as shown in FIG. 11, after the transfer of the image to the image receiving sheet 32 is started at the timing T1, the weight 71 vibrates along the conveyance direction. Then, one period C of vibration in the weight 71 indicated by a two-dot chain line includes a first portion P1 in which the weight 71 is dragged by a static frictional force with the moving body 73 and moves along the conveyance direction, and the weight 71. However, it is pulled by the restoring force of the spring 72, and includes two parts, the second part P2 that moves along the direction opposite to the conveying direction.

  The moving speed 73 of the moving body 73 is, for example, about several tens mm / sec, and the amplitude of the weight 71 along the transport direction is about 0.1 mm. Therefore, in one period C of vibration, the ratio occupied by the first part P1 is higher than the ratio occupied by the second part P2, and the period C of vibration is about several tens of msec.

  On the other hand, when the vibration damping mechanism is connected to the weight 71 as in the transfer mechanism 20 described above, the vibration damping mechanism suppresses vibration along the moving direction of the weight 71. That is, as indicated by a solid line in FIG. 11, the amplitude along the transport direction becomes small in both the first portion P1 and the second portion P2 included in one cycle C.

  Since the principle of such vibration is also applied to the transfer head 23, when the image on the transfer sheet 31 is transferred to the image receiving sheet 32, the transfer head 23 vibrates along the conveyance direction. When the transfer head 23 vibrates along the conveyance direction, the relative speed of the transfer head 23 with respect to the image receiving sheet 32 is not constant. Therefore, the uniformity of the transfer of the image forming layer 53 to the image receiving sheet 32 is lowered. As a result, in the image transferred to the transfer target, unevenness that is a portion different from the image P occurs.

  On the other hand, according to the transfer mechanism 20 described above, the vibration damping unit 27 suppresses vibration along the conveyance direction in the transfer head 23, so that the relative speed of the transfer head 23 with respect to the image receiving sheet 32 can be prevented from changing. . Therefore, the uniformity in transferring the image forming layer 53 to the image receiving sheet 32 is improved.

  Note that the vibration cycle of the transfer head 23 can be calculated using the moving speed of the image receiving sheet 32 and the force with which the transfer head 23 is pressed against the image receiving sheet 32, as described above. The vibration of the transfer head 23 is appropriately suppressed by selecting a vibration suppression condition by the vibration suppression unit 27 according to the calculated vibration cycle.

For example, an operation when the vibration control unit 27 is a mechanism that suppresses vibration using the viscosity of the fluid and the vibration control unit 27 is a damper that contains a fluid having viscosity therein will be described.
First, the equation of motion of the damped vibration is expressed by the following equation 2.

m · (d / dt) ^ 2 · x + γ · (d / dt) x + k · x−μ · N = 0 (Expression 2)
In Equation 2, (d / dt) represents one-time differentiation, and (d / dt) ^ 2 represents two-time differentiation. M is the mass of the transfer head 23, γ is a damping coefficient, and k is a spring constant.

Of the above formula 2, the following formula 3 excluding γ · (d / dt) x represents the vibration generated in the transfer head 23.
m · (d / dt) ^ 2 · x + k · x−μ · N = 0 (Expression 3)
When the fundamental period of vibration is ω0 and γ / (2 · m · ω0) = Γ, the behavior of the damped vibration varies depending on the value of Γ. In other words, when Γ> 1, the behavior of the damped vibration has a large degree of damping and is almost close to an exponential function. On the other hand, when Γ <1, the behavior of the damped vibration includes a plurality of vibrations and shows a behavior in which the amplitude gradually decreases.

  In the damping part 27, the length of the piston is L, the outer diameter of the piston is Sn, and the cross-sectional area along the direction perpendicular to the length direction of the piston at the orifice formed inside the piston is Sp. When the viscosity of the fluid contained in the cylinder is μ, the damping coefficient γ is expressed by the following formula 4.

γ = 8π · μ · L (Sp / Sn) ^ 2 (Formula 4)
For example, when the fluid contained in the cylinder is silicon oil having a viscosity μ of about 1000 and the amplitude of the transfer head 23 is 0.1 mm, the cross-sectional area Sp of the orifice with respect to the outer diameter Sn of the piston is When the ratio, that is, the value of Sp / Sn is about 30, Γ = 1. Therefore, by setting the value of Sp / Sn to a value in the vicinity of 30, either Γ> 1 or Γ <1 is possible. Therefore, by using a damper as the damping unit 27, it is possible to both attenuate the vibration exponentially and to attenuate the vibration by gradually reducing the amplitude of the vibration.

As described above, according to the image transfer apparatus of the above-described embodiment, the effects listed below can be obtained.
(1) Since the vibration control mechanism suppresses that the transfer head 23 moves along a direction parallel to the transport direction, the transfer head 23 can be suppressed from vibrating along the transport direction.

  (2) Since the connecting portion 28 has flexibility, when the urging member 25 moves the transfer head 23 along the direction opposite to the transport direction, the movement of the transfer head 23 is hardly hindered. Therefore, it is possible to prevent the transfer head 23 that has been moved along the conveyance direction by the movement of the two sheets from becoming difficult to return to the initial position.

  (3) When the connection portion 28 is connected to the transfer head 23 at two connection positions, the transfer head 23 of the vibration control mechanism is compared with the configuration in which the connection portion 28 is connected to the transfer head 23 at one connection position. The effect of suppressing vibration is suppressed from being biased in the width direction. Therefore, the inclination of the transfer head 23 with respect to the transport direction can be suppressed from becoming larger than when the transfer head 23 is located at the initial position.

  (4) When the connection portion 28 is connected to the transfer head 23 at one connection position located in the center in the width direction, the effect of suppressing the vibration of the transfer head 23 by the vibration control mechanism is It becomes easy to be transmitted to the whole.

(5) Since the vibration control mechanism suppresses the vibration of the transfer head 23 with a period different from the control period, the image unevenness due to the vibration of the transfer head 23 is more effectively suppressed.
(6) When the vibration control unit 27 is a damper, the vibration of the transfer head is appropriately suppressed by the damper provided in the vibration control mechanism.

(7) When the vibration control unit 27 is a spring, the vibration of the transfer head is appropriately suppressed by the spring provided in the vibration control mechanism.
The embodiment described above can be implemented with appropriate modifications as follows.

  The vibration control mechanism does not prevent the transfer of the image by the transfer head 23, and when the period of vibration of the transfer head 23 accompanying the conveyance of the transfer sheet 31 and the image receiving sheet 32 is equal to the control period, The vibration may be configured to suppress vibration having a period equal to the control period.

  In the configuration in which the connection unit 28 is connected to the transfer head at one connection position, the connection position may be a position other than the center in the width direction. Even with such a configuration, as long as the vibration damping unit 27 is connected to the transfer head 23, vibration along the transport direction in the transfer head 23 can be suppressed to some extent.

  When the connection part 28 is connected to the transfer head at two connection positions arranged in the width direction, the connection part 28 may be configured by two connection part constituting parts connected in parallel to one vibration damping part. In each of the two connection portion constituting portions, it is only necessary that one end portion is connected to the vibration control portion 27 and the other end portion is connected to the transfer head 23. Even with such a configuration, as long as the connection portion 28 is connected to the transfer head 23 at two connection positions, an effect equivalent to the effect obtained by the transfer mechanism 20 described above can be obtained.

  The connection portion 28 may be connected in parallel to the transfer head 23 at three or more connection positions in the width direction. At this time, the connection unit 28 may be connected to the vibration control unit 27 at one connection position, and may be divided into three or more while extending from the vibration control unit 27 toward the transfer head 23. Or the connection part 28 may be comprised from three or more connection part structure parts.

  The connecting portion 28 may be a rigid body that does not have flexibility. Even in such a configuration, it is only necessary that the transfer head 23 can be positioned at the initial position by moving the transfer head 23 in the direction opposite to the conveyance direction by the force of the urging member 25. Further, the connection unit 28 may be omitted, and the vibration control unit 27 may be directly connected to the transfer head 23.

  Two or more vibration control units 27 may be connected in parallel to the transfer head 23 via mutually different connection units 28. At this time, it is preferable that the two or more damping parts 27 have the same action of suppressing vibration.

  The transfer head 23 may be configured to be pressed against the image receiving sheet 32 only when the image on the transfer sheet 31 is transferred to the image receiving sheet 32. In other cases, the transfer head 23 is positioned on the outer peripheral surface of the transfer stage 21. The image receiving sheet 32 may be separated from the image receiving sheet 32. With such a configuration, it is preferable that the transfer mechanism 20 includes an adjustment mechanism that adjusts the tension of the connection portion 28. When the transfer head 23 is away from the image receiving sheet 32, the adjusting mechanism preferably adjusts the tension of the connecting portion 28 so that the connecting portion 28 bends. On the other hand, when the transfer head 23 is pressed against the image receiving sheet 32, the adjusting mechanism increases the tension of the connection portion 28 so that the connection portion 28 is stretched between the vibration damping portion 27 and the transfer head 23. Is preferred.

  When the vibration control unit 27 is a damper, the vibration control unit 27 does not have to satisfy the expressions 2 to 4 described above. Even in such a configuration, if the vibration control unit 27 is positioned alongside the transfer head 23 in the transport direction, vibration along the transport direction in the transfer head 23 can be suppressed to some extent.

  The transfer head 23 may be a transfer head that is used for transfer other than intermediate transfer, and may be any transfer head 23 that performs transfer between a transfer sheet and an image receiving sheet.

  DESCRIPTION OF SYMBOLS 10 ... Image transfer apparatus 20, 60 ... Transfer mechanism, 21 ... Transfer stage, 22 ... Transfer side roller, 23 ... Transfer head, 24 ... Heat generating part, 25 ... Energizing member, 26 ... Image receiving side roller, 27 ... Damping , 28 ... connection part, 31 ... transfer sheet, 32 ... image receiving sheet, 41 ... image receiving side substrate, 42 ... image receiving side peeling layer, 43 ... image receiving layer, 51 ... transfer side substrate, 52 ... transfer side peeling layer, 53 ... Image forming layer 54 ... Adhesive layer 71 ... Weight 72 ... Spring 73 ... Moving body 74 ... Force E ... External computing device P ... Image PD ... Image data

Claims (7)

A transport mechanism that transports the transfer sheet and the image receiving sheet along a transport direction in a state where the transfer sheet and the image receiving sheet face each other;
A transfer head that heats the transfer sheet and the image receiving sheet being transported by the transport mechanism and transfers an image of the transfer sheet to the image receiving sheet;
The transfer head is pressed against the transfer sheet and the image receiving sheet being transported by the transport mechanism in a state where the transfer head is movable along the transport direction, and the distance that the transfer head moves is A biasing member that moves the transfer head along a direction opposite to the transport direction when a predetermined distance is exceeded;
A vibration damping mechanism that is positioned alongside the transfer head in the transport direction and suppresses vibration along the transport direction, which is a repetition of movement of the transfer head in the transport direction and movement in the reverse direction. And an image transfer device. The vibration suppression mechanism includes a connection portion connected to the transfer head, and a vibration suppression portion connected to the transfer head via the connection portion,
The image transfer apparatus according to claim 1, wherein the connection portion has flexibility to bend by receiving a force from the transfer head along a direction opposite to the transport direction. The transfer head extends along a width direction that is a direction intersecting the transport direction,
The image transfer apparatus according to claim 2, wherein the connection portion is connected to the transfer head at a plurality of connection positions in the width direction. The transfer head extends along a width direction that is a direction intersecting the transport direction,
The image transfer apparatus according to claim 2, wherein the connection portion is connected to the transfer head at one connection position located at a center in the width direction. The transfer head repeats transfer at a predetermined control cycle,
The image transfer device according to any one of claims 1 to 4, wherein the vibration suppression mechanism suppresses vibration having a period different from the control period in the vibration of the transfer head. The image transfer device according to any one of claims 1 to 5, wherein the vibration control mechanism includes a damper that controls the transfer head by the flow of a viscous fluid. The image transfer device according to any one of claims 1 to 6, wherein the vibration control mechanism includes a spring that controls the transfer head by a restoring force.

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