JP5578402B2 - Thermal transfer printer - Google Patents

Description

  The present invention relates to a thermal transfer printer.

Generally, a thermal transfer printer includes a heat transfer unit, a peeling unit, and a peeling auxiliary member.
The heating transfer section (thermal head) is for heating the thermal transfer ribbon to transfer the dye or pigment to the recording sheet. The peeling means (ribbon take-up core) is for peeling the thermal transfer ribbon from the recording sheet. The peeling auxiliary member assists the peeling of the thermal transfer ribbon by pressing the thermal transfer ribbon moving in the peeling direction by the peeling means with the surface in the middle part thereof.

By the way, in this type of thermal transfer printer, the generation of wrinkles on the thermal transfer ribbon is known as one of the factors affecting the transfer quality of the dye or pigment applied to the thermal transfer ribbon onto the recording sheet. In other words, when wrinkles occur on the thermal transfer ribbon, the transfer quality deteriorates.
The following reasons are considered as the cause of wrinkles. In other words, the already transferred portion that has lost the dye or pigment after finishing the transfer on the thermal transfer ribbon (the dye or pigment has been transferred) forms a thermal transfer ribbon compared to the untransferred portion to which the dye or pigment is applied. The film is loose. This is due to heating by the heat transfer unit. Even if such a thermal transfer ribbon is peeled off from the recording sheet, the amount of extension between the already transferred portion and the untransferred portion is different. For this reason, wrinkles occur at the boundary between the already transferred portion and the untransferred portion.

Therefore, as a thermal transfer printer that suppresses the occurrence of such wrinkles, a technique shown in Patent Document 1 below has been proposed.
In the thermal transfer printer disclosed in Patent Document 1, the intermediate portion of the thermal transfer ribbon that moves in the peeling direction using a peeling assisting member (referred to as “peeling member” in Patent Document 1) is placed in the entire width direction. It is the structure which peels while pressing with a peeling auxiliary member over, Comprising: As a peeling auxiliary member, the structure which curved so that the part which contact | connects the center part of a thermal transfer ribbon may dent rather than the part which contact | connects both ends is employ | adopted. .

JP-A-7-266649

In the thermal transfer printer disclosed in Patent Document 1, in order to suppress the generation of wrinkles on the thermal transfer ribbon, the part that contacts the center part of the thermal transfer ribbon is recessed as compared to the part that contacts both end parts as a peeling auxiliary member. It is curved.
However, in this configuration, there is a problem that wrinkles of the thermal transfer ribbon cannot be sufficiently suppressed.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a thermal transfer printer that can reliably suppress the generation of wrinkles on a thermal transfer ribbon.

The thermal transfer printer of the present invention includes a heating transfer unit for heating the thermal transfer ribbon to transfer the dye or pigment to the recording sheet facing the thermal transfer ribbon, a peeling unit for peeling the thermal transfer ribbon from the recording sheet, and the peeling unit A peeling auxiliary member that assists the peeling from the recording sheet by pressing the thermal transfer ribbon that moves in the peeling direction, and the peeling auxiliary member has a width direction region that protrudes from both ends in the width direction of the recording sheet. And a roller that presses a predetermined region on the surface inside the width direction end of the thermal transfer ribbon.

In the above configuration, the thermal transfer ribbon is heated by the heat transfer unit and the dye or pigment is thermally transferred to the recording sheet, and the thermal transfer ribbon is peeled off from the recording sheet by the peeling means, and the thermal transfer ribbon moving in the peeling direction is a peeling aid. It is pressed by the member.
When the peeling assisting member presses a predetermined area on the surface inside the width direction of the thermal transfer ribbon on the surface of the thermal transfer ribbon, the restriction by the peeling assisting member is relaxed in the non-pressed part, and the degree of freedom is increased accordingly. Therefore, the generation of wrinkles at the boundary between the already transferred portion where the dye or pigment has been lost after the transfer on the thermal transfer ribbon and the untransferred portion where the dye or pigment is applied is reliably suppressed. Further, according to this configuration, the peeling assisting member presses the predetermined region on the surface across the width direction region that protrudes from both ends in the width direction of the recording sheet and inside the width direction end of the thermal transfer ribbon. The thermal transfer ribbon can be reliably peeled from the recording sheet.

  According to the thermal transfer printer of the present invention, the peeling assisting member presses the predetermined area on the surface inside the widthwise end of the surface of the thermal transfer ribbon that moves in the direction to be peeled off by the peeling means. It is possible to reliably suppress the generation of wrinkles at the boundary portion between the already transferred portion where the dye or pigment has been lost after finishing and the untransferred portion where the dye or pigment is applied.

Schematic plan view showing the internal structure of a thermal transfer printer showing an embodiment of the present invention A schematic side view showing the internal structure Partially enlarged side view showing the internal structure Similarly, the main part enlarged plan view Single figure of peeling auxiliary member showing other embodiments of the present invention

Embodiments of a thermal transfer printer according to the present invention will be described below with reference to the drawings.
1 is a schematic plan view showing an internal structure of a thermal transfer printer showing an embodiment of the present invention, FIG. 2 is a schematic side view showing the internal structure, FIG. 3 is a partially enlarged side view showing the internal structure, and FIG. It is a principal part enlarged plan view similarly.

  As shown in FIGS. 1 and 2, the thermal transfer printer performs printing on a sheet feeding unit 1 in which a roll 11 around which a transfer sheet P is wound is accommodated, and a transfer sheet P sent out from the sheet feeding unit 1. A printing unit 2 for performing printing and a paper discharge unit 3 for cutting and transferring the transfer sheet P printed by the printing unit 2 to the outside are provided. The paper feeding unit 1 is on the upstream side in the conveyance direction of the transfer sheet P, the paper discharge unit 3 is on the upstream side in the conveyance direction of the transfer sheet P, and the printing unit 2 is between the paper feeding unit 1 and the paper discharge unit 3. In other words, the transfer sheet P is arranged in the middle of conveyance.

The paper feeding unit 1 conveys the roll 11, a guide 13 a for guiding the transfer sheet P sent out from the roll 11 along the conveyance path, and the transfer sheet P guided by the guide 13 a toward the printing unit 2. For this purpose, a paper feed roller 14 and a paper feed pinch roller 15 disposed opposite to the paper feed roller 14 are provided.
The roll 11 is configured to be freely rotatable in both the forward and reverse directions by the power of a roll motor (not shown).
By rotating the roll motor in the forward rotation direction, the roll 11 rotates clockwise in FIG. By rotating the roll motor in the reverse direction, the roll 11 rotates counterclockwise in FIG.

As shown in FIG. 2 and FIG. 3, the printing unit 2 includes a heating transfer unit (hereinafter referred to as “thermal head”) 21, a platen roller 22 arranged to face the heating part of the thermal head 21, and the paper feeding unit 1. The sheet feeding roller 14 includes a feed roller 23 for feeding the transfer sheet P between the thermal head 21 and the platen roller 22, and a pinch roller 24 disposed opposite to the feed roller 23.
Further, downstream of the thermal head 21 in the transport direction, a print start position sensor 25 that detects that the transfer sheet P is positioned at the print start position, and the transfer sheet P is transported to the print start position sensor 25 side. The sub-feed roller 26 and a sub-pinch roller 27 disposed opposite to the sub-feed roller 26 are provided.

A thermal transfer ribbon (hereinafter referred to as “ink ribbon”) R is detachably provided in the printing unit 2. The ink ribbon R is initially a supply-side ribbon roll 201 around which an untransferred (unused) ink ribbon R is wound.
The ink ribbon R is drawn out from the supply-side ribbon roll 201 and used, and then the already-transferred (used) ink ribbon R is wound to become the winding-side ribbon roll 202.
The already-transferred ink ribbon R is configured to be sequentially wound around the drive shaft R1 so that the ink ribbon R is wound into the winding-side ribbon roll 202. The driving shaft R1 and a driving device (not shown) for rotating the driving shaft R1 about its axis correspond to the peeling means. The width B1 of the ink ribbon R is set to be larger than the width B2 of the transfer sheet P, and the dyes or pigments of the ink ribbon R are transferred by the thermal head 21 with the respective centers in the width direction aligned. Transferred to the sheet P.

  The printing unit 2 further includes ribbon guide rollers 203 and 204 and a peeling auxiliary roller 205 (corresponding to a peeling auxiliary member). The ribbon guide rollers 203 and 204 guide the ink ribbon R drawn from the supply side ribbon roll 201 so as to move between the thermal head 21 and the platen roller 22 (transfer surface of the transfer sheet P).

  The peeling assist roller 205 is for assisting the peeling of the ink ribbon R from the transfer sheet P. The auxiliary peeling roller 205 has a circumferential surface arranged in a direction perpendicular to the transport direction of the ink ribbon R in the width direction of the ink ribbon R, so that one surface of the ink ribbon R (the side on which no dye or pigment is applied). The thermal head 21 is disposed in the vicinity of the drive shaft R1 side so as to press only a part of the surface in the width direction.

The ink ribbon R is bent and conveyed by the ribbon guide rollers 203 and 204 and the peeling auxiliary roller 205 so that the conveying direction is changed while being pulled out from the supply side ribbon roll 201 and wound around the drive shaft R1. It becomes the composition which is done.
The ink ribbon R is composed of a color patch in which ink layers of three colors Y (yellow), M (magenta), and C (cyan) and an L (laminate) layer are periodically arranged. Cueing is performed by detecting a cueing mark for positioning (positioning) provided at the head of each color by a detecting means such as a reflective sensor.
In the figure, the two-dot chain line indicates the transfer sheet P (passage path K1) drawn from the roll 11, and the one-dot chain line indicates the ink ribbon R (passage path K2).

As shown in FIGS. 1 and 4, the peeling assist roller 205 is set longer than the length in the width direction of the ink ribbon R, and both ends thereof are rotatably supported by a printer housing (not shown). .
The peeling assist roller 205 has a large diameter portion 2051 that presses one surface of the ink ribbon R by removing the vicinity of both end portions Ra and Rb, and a smaller diameter than the large diameter portion 2051, and from the end of the large diameter portion 2051. The small-diameter portions 2052 and 2052 project outward in the width direction (axial direction).
The small diameter portions 2052 and 2052 do not contact one surface of the ink ribbon R. The cross-sectional shape of the large diameter portion 2051 is formed in a circular shape having the same diameter in the axial direction.

In other words, the peeling assisting roller 205 includes a pressing portion that contacts the ink ribbon R and presses the predetermined area, and a non-pressing portion that does not contact the ink ribbon R (non-pressing portion that does not press the ink ribbon R). Have. The following three patterns can be considered for the axial length corresponding to the predetermined region in the pressing portion. That is,
(1) smaller than the width of the transfer sheet P (2) substantially equal to the width of the transfer sheet P (3) larger than the width of the transfer sheet P and smaller than the width of the ink ribbon R.

It is preferable that the large diameter portion 2051 of the peeling assist roller 205 is pressed including a region facing the transfer sheet P in the ink ribbon R (a region where both overlap).
In this embodiment, the axial length L1 (width direction length) of the large diameter portion 2051 of the auxiliary peeling roller 205 is set longer than the width B2 of the transfer sheet P. Further, the axial length L1 of the large diameter portion 2051 is set smaller than the width B1 of the ink ribbon R. That is, it corresponds to (3) among the patterns (1) to (3) with the large diameter portion 2051 as the pressing portion.
With this configuration, the ink ribbon R is pressed to the transfer sheet P side in the width direction inner side than both ends Ra and Rb of one surface including the entire region facing the transfer sheet P.

  The paper discharge unit 3 includes a cutter 31 for cutting the transfer sheet P, a paper discharge roller 32 for transporting the cut transfer sheet P to be discharged to a paper discharge port (not shown), and this discharge. A paper discharge pinch roller 33 disposed to face the paper roller 32 is provided.

Next, the process of printing on the transfer sheet P will be described.
The transfer sheet P is set in a roll 11 state, the transfer sheet P is pulled out, the leading end thereof is sandwiched between the paper feed roller 14 and the paper feed pinch roller 15, and loading is performed. In this loading, the transfer sheet P is sent out by driving the roll motor, and the leading edge of the transfer sheet P is conveyed to the standby position on the printing unit 2 side by driving the paper feed roller 14 and the feed roller 23. It is.

When the leading edge of the transfer sheet P is positioned at the standby position and a print start command is output from a control unit (not shown), the transfer sheet P is transported further downstream from the standby position in the transport direction, and the print start position sensor 25 performs transfer. When the sheet P is detected, the transfer of the transfer sheet P is stopped.
Subsequently, the thermal head 21 that is separated from the platen roller 22 moves toward the approaching side and presses the ink ribbon R toward the transfer sheet P. From this state, the transfer sheet P is rewound to the roll 11 side by a predetermined length, and the ink ribbon R is fed from the supply side ribbon roll 201 at the same speed as the transfer speed of the transfer sheet P and wound around the drive shaft R1. As a result, the ink ribbon R is heated by the thermal head 21, and Y (yellow) ink, for example, a dye or a pigment is transferred.

  After the transfer is completed, the thermal head 21 is separated from the platen roller 22, and then the transfer sheet P is sent to a position detected by the print start position sensor 25 to transfer M (magenta) ink, which is a dye or pigment. Subsequently, in the same manner, C (cyan) ink, which is a dye or pigment, and a laminate layer are sequentially transferred to complete printing. When printing is completed, the transfer sheet P is sent to the paper discharge port 3A side and cut by the cutter 31, and the cut print paper is discharged from the paper discharge port 3A to the outside of the printer.

In the printing process, when the dye or pigment of the ink ribbon R is transferred to the transfer sheet P, the ink ribbon R is sequentially wound around the drive shaft R1. At this time, the ink ribbon R is peeled from the transfer sheet P. The ink ribbon R is peeled off while the drive shaft R1 rotates and the ink ribbon R is pressed by the outer peripheral surface of the peeling auxiliary roller 205.
Here, the peeling assist roller 205 is pressed by the large diameter portion 2051 with one end of the ink ribbon R removed from both ends Ra and Rb, and the small diameter portions 2052 and 2052 are not in contact with one surface of the ink ribbon R and are not in contact with the ink ribbon R. Do not press the ribbon R.

In this way, the pressing portion of the peeling assist roller 205 presses over the width direction region of the ink ribbon R that protrudes from both ends in the width direction of the transfer sheet P. In short, the peeling assist roller 205 presses only a predetermined region in the width direction of one surface of the ink ribbon R. For this reason, a portion that is not pressed by the auxiliary peeling roller 205 is generated in the ink ribbon R, and since the restriction (pressing) by the auxiliary peeling roller 205 is relaxed in that portion, the portion that has the degree of freedom in the ink ribbon R correspondingly. (Region indicated by the symbol F) occurs.
For this reason, the force that pulls the ink ribbon R in the peeling direction is equalized, and the boundary portion between the already transferred portion that has lost the dye or pigment after the transfer on the ink ribbon R and the untransferred portion to which the dye or pigment is applied It is possible to reliably suppress the generation of wrinkles in the area. Therefore, a transfer sheet P with good transfer quality can be obtained.

  Further, the peeling assist roller 205 presses a predetermined area facing the transfer sheet P in the ink ribbon R. In this embodiment, the entire region of the ink ribbon R that faces the transfer sheet P is included. For this reason, the ink ribbon R can be reliably peeled from the transfer sheet P.

  The present invention is not limited to the above embodiment. In particular, the configuration of the peeling assisting member is not limited to the above embodiment. In each of the above embodiments, a roller is described as an example of the peeling assisting member. Also good. In this case, it is preferable that a portion of the pressing portion that presses the ink ribbon R that is in contact with the ink ribbon R is a curved surface.

As another example in which the peeling assisting member is in the form of a roller, a configuration as shown in FIG.
The auxiliary peeling roller 206 shown in this other example has a pressing part 2061 and a non-pressing part 2062. The pressing portion 2061 is formed in a circular cross section having the same diameter in the axial direction, that is, a cylindrical shape, and the non-pressing portion 2062 is formed in a circular cross section that decreases in diameter toward the outer side in the axial direction, that is, a truncated cone shape. The outer peripheral surface of the non-pressing portion 2062 is a continuous tapered surface on the outer peripheral surface of the pressing portion 2061 with the boundary 2061a in the figure.
Also in this case, the axial length of the pressing portion 2061 is set so as to press the ink ribbon R in a region corresponding to the entire width direction of the transfer sheet P, and the ink ribbon R is pressed inside the end portion. Yes.

Since the outer peripheral surface of the non-pressing portion 2062 is a tapered surface, a region that contacts the ink ribbon R and a region that is difficult to contact or a region that does not contact are generated.
In the pressing portion 2061, one surface of the ink ribbon R is pressed in the contact area, but the pressing force is sufficiently small in the area that is difficult to contact with the area that contacts the ink ribbon R or in the area that does not contact. For this reason, when the ink ribbon R is peeled from the transfer sheet P, the restriction by the peeling assisting roller 206 is relaxed, and a portion having a degree of freedom is generated in the ink ribbon R correspondingly.
Therefore, the force of pulling the ink ribbon R in the peeling direction is equalized, and at the boundary portion between the already transferred portion that has lost the dye or pigment after the transfer on the ink ribbon R and the untransferred portion to which the dye or pigment is applied. The generation of wrinkles can be reliably suppressed.

In the embodiment shown in FIG. 5, the area in the width direction of the ink ribbon R pressed by the pressing portion 2061 of the auxiliary peeling roller 206 is
(1) smaller than the width of the transfer sheet P (2) substantially equal to the width of the transfer sheet P (3) larger than the width of the transfer sheet P and smaller than the width of the ink ribbon R Good.

In each of the above embodiments, in order to press only a predetermined area (a part) on one surface of the ink ribbon R, the axial length of the pressing portion that presses one surface of the ink ribbon R among the peeling assist rollers is set to the ink ribbon R. It was set smaller than the width B1.
However, the present invention may be configured such that a predetermined region on one surface of the ink ribbon is pressed by the pressing portion of the peeling auxiliary member by shifting the peeling auxiliary member in the width direction with respect to the ink ribbon. However, even in this case, it is preferable that the range in which the ink ribbon is pressed is inward from the end of the ink ribbon.
Even in such a configuration, the restriction by the peeling assisting member is relaxed in the portion where the ink ribbon is not pressed, and a portion having a degree of freedom is generated in the ink ribbon accordingly. For this reason, the force which pulls an ink ribbon in a peeling direction is equalized, and generation | occurrence | production of a wrinkle can be prevented reliably.
In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Paper feed part, 2 ... Printing part, 3 ... Paper discharge part, 3A ... Paper discharge port, 11 ... Roll, 14 ... Paper feed roller, 21 ... Thermal head, 22 ... Platen roller, 201 ... Supply side ribbon roll, 202: Winding side ribbon roll, 203, 204 ... Ribbon guide roller, 205 ... Peeling auxiliary roller, 2051 ... Large diameter part, 2052, 2052 ... Small diameter part, P ... Transfer sheet, R ... Ink ribbon, R1 ... Drive shaft, Ra, Rb ... both ends

Claims (1)

A heat transfer section for heating the thermal transfer ribbon to transfer the dye or pigment to the recording sheet facing the thermal transfer ribbon, a peeling means for peeling the thermal transfer ribbon from the recording sheet, and a movement in the peeling direction by the peeling means And a peeling assisting member that assists the peeling from the recording sheet by pressing the thermal transfer ribbon,
The peeling assisting member is a rotatable roller that presses a predetermined region on a surface inside the width direction end of the thermal transfer ribbon across the width direction region protruding from both ends of the recording sheet in the width direction. Thermal transfer printer characterized by

Images