JP2000025315A - Sublimation thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sublimation thermal printer and a picture forming method, which permit the restraining of unsettled condition of a card effectively upon printing while restraining a cost so as to be low and permit the forming of a high-quality picture on the card or the like by the effective restraining of the unsettled condition. SOLUTION: Separating rollers 27, 28, providing an ink ribbon IR with a force orthogonal to the surface of a card C at a position apart from a thermal head 20 by a predetermined distance S into an advancing direction along the surface of the card C, are provided, whereby the card C receives only the force orthogonal to the surface of the same upon separating the ribbon IR even when the degree of adhesion between the ink ribbon IR and the card C is different depending on the light and shade of the picture. According to this method, the unsettled condition of the card C with respect to the advancing direction of the same can be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a technique for forming an image by thermal transfer from an ink ribbon to a card or the like.

[0002]

2. Description of the Related Art By heating an ink ribbon with a thermal head in which a plurality of heating elements are arranged in a line, ink separated sublimationally from the ink ribbon is transferred to a card or the like and fixed thereon to form an image. Are known. According to such a sublimation thermal printer, an image such as a photograph can be printed clearly, so that it is widely used for printing cards such as membership cards.

When printing is performed using such a sublimation thermal printer, the heating elements of the thermal head are arranged in a line, so that each heating element is heated separately and a card is mounted on the thermal head. Need to be moved in synchronization with the timing of heating.
In such a case, the card moves below the heating element of the thermal head by being pressed by the pressing member at the rear end center.

On the other hand, the ink ribbon is taken up by a take-up roller along with the movement of the card, and is pulled obliquely upward in the traveling direction to separate from the card after passing through the thermal head. .

However, since the winding diameter of the take-up roller increases as printing proceeds, there is a characteristic that the peripheral speed increases when the rotation speed is kept constant. On the other hand, in a portion where the density of the image is uniformly dark, the sticking force between the ink ribbon and the card is locally increased by the fixed ink. That is, it can be said that it is difficult to peel off the ink ribbon from the card while adjusting the rotational torque of the take-up roller by a simple control mode.

Therefore, a tension roller attached to a swing arm is provided in front of the take-up roller, and the ink ribbon is pulled with a constant pulling force regardless of the winding diameter of the take-up roller. The ink ribbon is separated at the position.

[0007]

However, the swing amount of the swing arm is limited, and when the swing arm swings to its limit, the tension function does not work. In such a case, depending on the peripheral speed of the take-up roller and the state of the density of the image, the ink ribbon may not be immediately separated from the card, but may be separated uncontrollably downstream of the thermal head.

On the other hand, since the card is pressed and held in a line between the thermal head and the platen roller, and the center of the rear end is merely pushed, the yawing motion is easily generated. Therefore, if the ink ribbon uncontrollably separates from the card at a considerable downstream of the thermal head, the card may wobble (yaw) under a large moment. However, during the movement, the card performs image transfer at a plurality of stages using a plurality of ink ribbons, that is, so-called multicolor printing, so if the card moves while wobbling, the image formed Shift and blur are likely to occur for each color.

On the other hand, a guide for suppressing the side surface of the card when moving is provided, so that the fluctuation of the card is suppressed to some extent. However, due to component placement issues,
When the card passes below the thermal head, the guide of the card is interrupted once, and when the card passes through the thermal head, the guide starts again. Therefore, when the card passes below the thermal head, the guide of the card does not function sufficiently, and the risk of the card wobbling remains.

If the moving speed of the card is suppressed in order to suppress such a wobble of the card, there arises a problem that the printing speed of the card is reduced and the efficiency is reduced. On the other hand, if the card is gripped and moved by a member having higher rigidity, the fluctuation can be suppressed, but the cost is higher.

In view of the problems of the prior art, the present invention can effectively suppress the fluctuation of the card at the time of printing while keeping the cost low, thereby forming a high quality image on the card or the like. And a sublimation thermal printer and an image forming method.

[0012]

In order to achieve the above object, a sublimation thermal printer of the present invention forms an image by transferring ink separated from an ink ribbon by heating with a thermal head to a card. Means for applying a force to the ink ribbon in a direction perpendicular to the surface of the card at a position separated from the thermal head by a predetermined distance in a traveling direction along the surface of the card. It is characterized by being provided.

The image forming method according to the present invention includes a step of sandwiching an ink ribbon between a thermal head and a card;
While heating the thermal head according to the image to be transferred,
Winding the ink ribbon in synchronization with the card; and, at a position separated from the thermal head by a predetermined distance in a traveling direction along the surface of the card, the ink ribbon in a direction perpendicular to the surface of the card. And a step of applying force.

[0014]

According to the sublimation thermal printer of the present invention, the ink ribbon is applied to the ink ribbon in a direction perpendicular to the surface of the card at a position separated from the thermal head by a predetermined distance in the traveling direction along the surface of the card. Because a means for applying force is provided, even if the degree of sticking between the ink ribbon and the card differs depending on the density of the image, for example, when the ink ribbon is peeled off, the card is held only in the direction perpendicular to the surface of the card. Since the card is subjected to the force, it is possible to suppress the fluctuation in the moving direction of the card.

According to the image forming method of the present invention, the ink ribbon is applied to the ink ribbon in a direction perpendicular to the surface of the card at a position separated from the thermal head by a predetermined distance in a traveling direction along the surface of the card. Since the card has a step of applying force, even if the degree of sticking between the ink ribbon and the card is different due to, for example, shading of the image, when the card is peeled off, the card receives a force only in the vertical direction with respect to the surface of the card. As a result, it is possible to suppress the fluctuation of the card in the traveling direction.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a top view of a sublimation thermal printer 10 according to an embodiment of the present invention. Printer 10
A control device group 11 for controlling various devices described later is disposed behind (upper portion in FIG. 1). On the right side of the printer 10, card storage units 12a and 12b capable of storing a large number of cards made of paper or thin plastic are arranged in parallel. The card C is taken out of the card storage units 12a and 12b by a take-out device (not shown), and is drawn out to a conveyor device 13 arranged in front of the printer 10.

The conveyor device 13 conveys the card C taken out to the first to fifth processing stages 14 to 18 and then to the completion position 19. First to first
In the fifth processing regions 14 to 18, for example, green, red,
Different ink ribbons such as blue and black are arranged, and ink is transferred corresponding to an image, so that multicolor printing is performed.

FIG. 2 is a view showing one of the processing stages 14 to 18 taken out. FIG. 2 (a) is a top view, and FIG. 2 (b) is a side view. In FIG. 2, the ink ribbon is omitted, and FIG.
3A, the thermal head 20 is also omitted. In FIG. 2 (b), the conveyor device 13 includes a pair of rollers 13 that are precisely rotated by a pulse motor (not shown).
b, an endless belt 13a stretched between 13c,
A driving member 13d is attached to a part of the endless belt 13a.

The driving member 13d has a pick member 23 projecting upward. The rear end of the card C is pushed by the pick member 23, and the card C moves toward the thermal head 20 while its side edge is guided by the guide members 21 and 24 (FIG. 2A). The guide members 21 and 24 terminate before the thermal head 20.

The guide member 24 includes a spring member 24a (FIG. 2).
The card C is pressed against the guide member 21 by the biasing force from (a)), thereby preventing the occurrence of a gap between the guide member 21 and the card C, and preventing the card C from wobbling. It is designed to move stably.

The card C conveyed to the thermal head 20 is sandwiched between the thermal head 20 and the platen roller 25 via an ink ribbon (not shown). At this time, the card C is arranged in a line at the lower end of the thermal head. A plurality of heating elements (not shown) are individually heated according to the image to be transferred, so that the ink on the ink ribbon is transferred to the card. On the other hand, the heating of the heating element is performed in synchronization with the movement of the card C, so that when the card C passes through the thermal head 20, an image is formed by a series of two-dimensional ink dots. ing. Thereafter, the card C is transported to the next processing stage, and another color ink is transferred in an overlapping manner.

On the other hand, if the card C is not guided after passing through the thermal head 20, the card C may fluctuate. Therefore, guide members 22 and 26 (FIG. 2A) are provided at positions passing through the thermal head 20 to guide the front end side of the card C.

Here, the distance between the guide members 22 and 26 is
If the width is substantially equal to the width W1 of the card C, the card C can be guided more stably. However, card C
Are guide members 21 and 24 near the thermal head 20.
In some cases, the sheet may be slightly shifted in the lateral direction in order to escape from the restraint. In such a case, if the interval between the guide members 22 and 26 is strictly equal to the width W1 of the card C, the front end of the card C
There is a possibility that the sheet may not be able to be conveyed by contacting one of the sheets 2 and 26.

Therefore, the distance W2 between the guide members 22 and 26
Is slightly widened with respect to the width W1 of the card C to ensure smooth conveyance of the card C. However, since the interval W2 between the guide members 22 and 26 is slightly wider than the width W1 of the card C, backlash occurs between the guide members 22 and 26 and the card C, and due to the state of sticking between the ink ribbon and the card C. The card C may fluctuate within the range of such play.

A mechanism according to the present embodiment for suppressing card wander will be described below. FIG. 3 is a side view of the mechanism. In FIG. 3, the card C is
With the ink ribbon IR placed on the upper surface, the ink ribbon IR is sandwiched between the thermal head 20 and the platen roller 25 and transported in the direction of the arrow.

On the downstream side of the thermal head 20,
The card C is transported with the ink ribbon IR adhered to the upper surface by the ink fixed by heating. Downstream from the thermal head 20, a pair of peeling rollers 27 and 28 are provided above a position separated by a distance S. The peeling rollers 27 and 28 as means for applying a force to the ink ribbon are rotated by a pulse motor (not shown) in synchronization with the movement of the conveyor device 13 (FIG. 2). The ink ribbon IR includes the pair of peeling rollers 2.
7 and 28, and is wound around a winding roller 34 via an idle roller 29 and a tension roller 30.

The tension roller 30 is rotatably supported by a free end of a swing arm 31, and the swing arm 31 is urged clockwise by a spring member (not shown). As a result, the tension roller 30, which can move to the left and right in the drawing, removes the slack by applying a predetermined tension to the ink ribbon IR. When the tension roller 30 and the swing arm 31 rotate counterclockwise and cannot rotate any more, the sensor 32 transmits a signal,
Thereby, the rotation of the winding roller 34 is stopped.

The operation of this embodiment will be described. 4 is a view similar to FIG. 3, but FIG. 4 (a) shows a state in which the front end of the card C has reached below the thermal head 20, and FIG. FIG. 3 is a diagram showing a state immediately after passing through the thermal head 20. First, FIG.
In the state shown in (1), the peeling rollers 27 and 28 are not rotating, and start rotating in synchronization with the movement of the card C from when the leading end of the card C reaches just below the peeling rollers 27 and 28. On the other hand, the take-up roller 34 also starts rotating from this point, but the rotation is constant regardless of the winding diameter.

While the card C passes below the peeling rollers 27 and 28, as shown in FIG.
Is vertically peeled off from the surface of the card C and wound up. Therefore, regardless of the density of the image, the ink ribbon IR is always peeled off at the same position, so that wobble can be suppressed as much as possible when the card C is transported. As described above, according to the present embodiment, it is possible to maintain high image quality at low cost.

On the other hand, as shown in FIG.
When the rear end reaches just below, the separation of the ink ribbon IR becomes unnecessary, and the rotation of the separation rollers 27 and 28 is stopped. Also in such a case, the take-up roller 34 continues to rotate, so that the ink ribbon I
The slack of R is removed. Thereafter, when the tension roller 30 and the swing arm 31 rotate counterclockwise due to the tension of the ink ribbon IR and the sensor 32 transmits a signal, the take-up roller 34 stops rotating. In that state,
Because the tension is applied, the ink ribbon IR
Means that the next card C is the thermal head 20 and the platen 25
When intruding in between, the state shown in FIG. 4A is maintained.

Although the present invention has been described with reference to the embodiment, the present invention should not be construed as being limited to the above-described embodiment, and it is needless to say that the present invention can be appropriately changed or improved. is there. For example, in the present embodiment, paper or thin plastic is exemplified as a card material, but the present invention is not limited to this, and other materials may be used.

[0032]

According to the thermal sublimation thermal printer of the present invention, the ink ribbon is provided at a position separated from the thermal head by a predetermined distance in the traveling direction along the card surface and in a direction perpendicular to the card surface. Is provided, for example, even if the degree of sticking between the ink ribbon and the card differs depending on the density of the image, when removing the card, the card is perpendicular to the surface of the card. Since only the force is received, it is possible to suppress the fluctuation in the moving direction of the card.

According to the image forming method of the present invention, a force is applied to the ink ribbon in a direction perpendicular to the surface of the card at a position separated from the thermal head by a predetermined distance in the traveling direction along the surface of the card. Therefore, even if the degree of sticking between the ink ribbon and the card differs depending on the density of the image, for example, the card is subjected to a force only in the vertical direction with respect to the surface of the card when the ink ribbon is peeled off. , It is possible to suppress the fluctuation of the card in the traveling direction.

[Brief description of the drawings]

FIG. 1 is a top view of a sublimation thermal printer 10 according to an embodiment of the present invention.

FIG. 2 is a view showing one of processing stages 14 to 18 taken out, and FIG. 2A is a top view thereof;
(B) is a side view thereof.

FIG. 3 is a side view of a mechanism for suppressing a wobble of the card.

4 is a view similar to FIG. 3, but FIG. 4A shows a state in which the front end of the card C has reached below the thermal head 20, and FIG. FIG. 3 is a view showing a state immediately after passing through the thermal head 20.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Printer 11 Control group 12a, 12b Card storage part 13 Conveyor device 14-18 Processing stage 20 Thermal head 21, 22, 24, 26 Guide member 25 Platen roller 27, 28 Peeling roller 30 Tension roller 31 Swing arm 34 Take-up roller C Card IR ink ribbon

Claims (4)

[Claims] 1. A sublimation thermal printer which forms an image by transferring ink separated from an ink ribbon by heating with a thermal head to a card, wherein the thermal head is provided with a predetermined direction in a traveling direction along a surface of the card. A sublimation thermal printer, further comprising means for applying a force to the ink ribbon in a direction perpendicular to the surface of the card at a position separated by a distance. 2. The sublimation thermal printer according to claim 1, wherein the means for applying the force is a pair of peeling rollers that sandwich the ink ribbon and rotate in synchronization with the movement of the card. 3. The apparatus according to claim 2, further comprising a take-up roller for taking up the ink ribbon, and a tension device provided between the take-up roller and the pair of rollers to apply tension to the ink ribbon. The sublimation thermal printer according to claim 1. 4. A step of sandwiching an ink ribbon between a thermal head and a card, and heating the thermal head according to an image to be transferred.
Winding the ink ribbon in synchronization with a card; and, at a position separated from the thermal head by a predetermined distance in a traveling direction along the surface of the card, the ink ribbon in a direction perpendicular to the surface of the card. Applying a force to the image.