JPH106625A - Thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal printer which reduces the wasteful consumption of an ink ribbon to the maximum possible extent. SOLUTION: This thermal printer consists of a supply roll means 51 with a back tension applying means, on which an ink ribbon R is wound around a roll shaft with a function to apply a back tension to the ink ribbon R, a take-up roll means 52 for taking up the ink ribbon R, a drive means for driving the take-up roll means 51, a thermal head 24 for holding the ink ribbon R provided between the supply roll means 51 and the take-up roll means 52 and a platen roller 26. In this case, the ink ribbon R is fed from a supply reel means by the rotating drive force of the platen roller 26, when the ink ribbon R is held, and at the same time, is taken up by the take-up roll means 52 with the help of a drive force by the drive means after the ink ribbon R is fed by the platen roller 26. In this case, the back tension is set higher than the take-up drive force by the drive means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer for printing predetermined information with a thermal head,
More specifically, the present invention relates to a thermal printer including a supply roll means for supplying an ink ribbon and a winding roll means for winding the ink ribbon.

[0002]

2. Description of the Related Art As a conventional thermal printer for performing printing by using a thermal head of this kind, a supply roll for supplying an ink ribbon, and a winding roll for winding the ink ribbon supplied from the supply roll by a driving force of a driving motor. There is known a printer including a thermal head and a platen roller configured to be able to pinch an ink ribbon bridged between a supply roll and a take-up roll, and a control unit that executes various processes. .

In this thermal printer, when printing,
The thermal head moved by the control unit presses the ink ribbon supplied from the supply roll onto the platen roller in a state where the ink ribbon and print paper are overlapped, and the ink ribbon is supplied from the supply roll unit by the rotational driving force of the platen roller. Are sequentially supplied. In this case, a predetermined back tension is applied to the ink ribbon supplied from the supply roller in order to remove slack from the platen roller. The ink ribbon sent out by the platen roller is taken up by a take-up roller in order to prevent the ink ribbon from being taken up by the platen roller due to slack.

On the other hand, after printing is completed, in a conventional thermal printer, the thermal head is separated from the platen roller to separate the printed print paper from the ink ribbon and to prevent the ink ribbon from being entangled by the platen roller. Then, the ink ribbon is wound by the winding driving force of the drive motor, and then, after stopping the platen roller, the drive motor is stopped. In this case, in general, a hard lead film is added to the leading end of the ink ribbon wound around the supply roll in order to facilitate winding the ink ribbon of the supply roll by the take-up roll. . For this reason, the winding force by the drive motor is smaller than the back tension applied to the ink ribbon supplied from the supply roller, for the purpose of allowing the winding roll to easily wind the lead film. Is also set to be large.

[0005]

However, this conventional thermal printer has the following problems. That is, in the conventional thermal printer, the winding force of the drive motor is set to be larger than the back tension of the supply roll. Therefore, since the thermal head is not pressed against the ink ribbon and the platen roller between the time when the thermal head is moved after the printing is completed and the time when the drive motor is stopped, the take-up roll has only the slacked ink ribbon. Instead, the ink ribbon is pulled out from the supply roll and wound up. As a result, the conventional thermal printer has a problem that the ink ribbon is wasted as much as newly drawn from the supply roll.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a thermal printer capable of minimizing waste of an ink ribbon.

[0007]

In order to achieve the above object, a thermal printer according to the present invention comprises a supply roll having back tension applying means for applying an ink ribbon to a roll shaft and applying a back tension to the ink ribbon. Means, a take-up roll means for taking up the ink ribbon supplied from the supply roll means, a drive means for driving the take-up roll means, and a bridge between the supply roll means and the take-up roll means. A thermal head and a platen roller configured to be able to clamp the ink ribbon, and when the ink ribbon is clamped, the ink ribbon is supplied from the supply reel means by the rotational driving force of the platen roller, and the ink ribbon is sent out by the platen roller. Ink ribbon to the take-up roll means by the driving force of the drive means In the thermal printer which is configured to take can, characterized by being larger than the take-up drive force by the drive means back tension by the back tension applying means.

In this thermal printer, at the time of printing, the ink ribbon stretched between the supply roll means and the take-up roll means rotates the platen roller while being held between the thermal head and the platen roller. Sent out by force. For this reason, the ink ribbon in the supply roll means is forcibly pulled out, and the ink ribbon sent out by the platen roller is taken up by the take-up roll means by the take-up driving force of the drive motor. On the other hand, when the thermal head is moved after the printing, the ink ribbon stretched between the supply roll means and the take-up roll means is taken up by the take-up roll means by the take-up driving force of the drive means. Can be In this case, since the back tension by the back tension applying unit is larger than the winding driving force of the driving unit, only the slack of the ink ribbon is wound up by the winding roll unit, and the ink ribbon is pulled out from the supply roll unit. This prevents wasteful winding of the ink ribbon.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a thermal printer (hereinafter, referred to as a "printer") according to the present invention is applied to a label printer will be described below with reference to the accompanying drawings.

FIG. 1 is a side sectional view of the main mechanical components of the printer 1. In this printer 1, when an operator inputs print data of characters and graphics by a keyboard using a separate information input device (for example, a personal computer), a desired label is pre-adhered to the mount based on the print data. Characters and figures are printed. Thereafter, the operator can peel the printed label from the backing sheet and adhere it to an arbitrary place.

Next, a schematic configuration of the printer 1 will be described with reference to FIG.

As shown in FIG. 1, the printer 1
A pair of plate-shaped roll paper support guides 10 for supporting the roll paper 3 formed by winding the label paper 2 having the label L attached thereto in a roll shape, and the width of the label paper 2 fed from the roll paper 3 A pair of plate-shaped label paper feed guides 11 that regulate movement in the direction, and a plurality of guide rollers 13 a and 13 that are disposed on the transport path 12 and transport the label paper 2.
b, 15 and pinch rollers 14a, 14b, 16;
The discharge roller 17 and the pinch roller 18 and the conveyance path 12
Light emitting element 2 for irradiating light to label paper 2 conveyed above
0, and a photosensor 22 comprising a light receiving element 21 for receiving irradiation light transmitted through the label paper 2, a thermal head (hereinafter, simply referred to as "head") 24, and a head 24 facing the head 24 and cooperating with the head 24 during printing. A platen roller 26 for sandwiching the label paper 2, a label discharge port 28 for discharging the label L on the label paper 2, and a mount discharge port for discharging the mount B via the guide roller 30 and the pinch roller 31. And a motor 34 for driving guide rollers 13a, 13b, 15, 30, the discharge roller 17, the platen roller 26, and a winding roll 52 in a transfer ribbon cassette 38, which will be described later, via a gear mechanism (not shown). And the following,
"Motor 34").

On the other hand, a control device 36 for executing various controls on the printing of the head 24 is provided below the body.

A head 24 configured to be vertically movable is attached to the upper part of the body, and a transfer ribbon cassette 38 containing a transfer ribbon R corresponding to the ink ribbon of the present invention is detachably mounted. ing. In the transfer ribbon cassette 38, a supply roll 51 for supplying the transfer ribbon R wound in a roll shape to the head 24 side, a winding roll 52 for winding the transfer ribbon R, and a guide for the transfer ribbon R. Guide roller 53,
And a guide roller 53 when the head 24 moves down.
A guide member 55 for guiding the transfer ribbon R between the heads 24 and a ribbon peeling plate 56 for peeling the transfer ribbon R from the label paper 2 are incorporated. A hydraulic brake (not shown) called a so-called oil damper or oil brake is provided on a roll shaft 51a of the supply roll 51. The hydraulic brake exerts a predetermined rotational resistance on the roll shaft 51a. By giving the transfer ribbon R, a predetermined back tension is applied to the transfer ribbon R. On the other hand, a friction clutch called a so-called slip clutch is provided on the roll shaft 52a of the take-up roll 52. The friction clutch transmits the driving force of the motor 34 to the roll shaft 52a via frictional force. , And prevents transmission of a driving force exceeding a specified torque. In this case, if the value of the rotational driving force by the platen roller 26 is Fa, the value of the back tension by the hydraulic brake is Fb, and the value of the winding force of the roll shaft 52a by the motor 34 is Fc, Fa>Fb> Fc The relationship is set as follows.

Next, referring to FIGS.
The overall operation of the printer 1 focusing on the supply control of the printer 1 will be described.

When a print command is output from the outside of the apparatus to the control device 36, the control device 36 drives the motor 34 so that the guide rollers 13a, 13b, 15, 3
0, the discharge roller 17, the platen roller 26 and the take-up roll 52 are driven. Along with this, the label paper 2 fed from the roll paper 3 is transported on the transport path 12.
When the label paper 2 passes through the photo sensor 22, the light emitted by the light emitting element 20 passes through the label paper 2, and the light receiving element 21 receives the transmitted light. Is the label L on the label paper 2
The position of the tip of is detected. When the label L is transported to the position of the head 24, the head 24 is moved downward, and the head 24 presses the platen roller 26 in a state where the transfer ribbon R and the label paper 2 are overlapped (see FIG. 2). . Next, printing is performed by transferring the ink of the transfer ribbon R to the label L by the heat generated by the head 24. In this state, the transfer ribbon R is sent out by the rotation driving force in a state where the platen roller 26 sandwiches the transfer ribbon R in cooperation with the head 24, thereby forcing the transfer ribbon R in the supply roll 51. Pull out one after another. On the other hand, the transfer ribbon R sent out by the platen roller 26 is taken up by the take-up roll 52 by the take-up driving force of the motor 34. For this reason, the platen roller 2
The transfer ribbon R is maintained in a tight state between the transfer roll 6 and the take-up roll 52. Thereafter, the label L is automatically peeled off from the mount B by being sandwiched between the guide roller 30 and the pinch roller 31, and the label L is carried out from the label discharge port 28, and
Is discharged from the mount outlet 32.

When a predetermined number of labels L have been printed, under control of the control device 36, the head 24
6 and move upward (see FIG. 3). In this state, the transfer ribbon R stretched between the supply roll 51 and the take-up roll 52 is momentarily slackened as indicated by a chain line in FIG. As a result, as shown by the solid line in the drawing, the tape is maintained tight between the guide rollers 53 and 54. In this case, since the back tension of the supply roll 51 due to the hydraulic brake is greater than the winding drive force of the motor 34, the friction clutch prevents the winding roller 52 from transmitting the winding drive force of the specified torque or more. . For this reason, as a result of the roll shaft 52a idling, only the slack of the transfer ribbon R is taken up by the take-up roll 52, and the transfer ribbon R is not pulled out from the supply roll 51. Winding is prevented. Next, the rotation of the platen roller 26 is stopped, and the printing ends.

As described above, various preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and can be appropriately modified. For example,
In the present embodiment, an example in which the transfer ribbon R is nipped by pressing the head 24 against the platen roller 26 has been described. However, the present invention is not limited to this, and the platen roller 26 may be configured to press the head 24. Further, the back tension applying means provided on the supply roll 51 is not limited to the hydraulic brake shown in the present embodiment, but may apply another type of mechanical, pneumatic or electromagnetic friction brake to apply the back tension. Is also good.
Further, in the present embodiment, a friction clutch is provided on the winding roll 52, but the present invention is not limited to this.
Other types of friction clutches can be used, and not only mechanical but also electrical and hydraulic / pneumatic clutches can be used.

In this embodiment, an example in which the present invention is applied to a label printer has been described. However, the present invention is not limited to this and can be applied to all thermal printers. Also, when applied to a label printer,
The present invention is not limited to the roll paper 3 as the label paper 2, but may be applied to a label printer that prints on sheet labels cut in advance to a predetermined size.

[0020]

As described above, according to the thermal printer of the present invention, the back tension by the back tension applying means on the supply roll means side is made larger than the winding driving force of the driving means. As a result, the excess amount of the ink ribbon is not wound up more than the slack, so that the waste of the ink ribbon can be reduced as much as possible.

[Brief description of the drawings]

FIG. 1 is a sectional view illustrating an outline of an internal structure of a label printer according to an embodiment.

FIG. 2 is an internal structural diagram showing a state of a transfer ribbon in the label printer according to the embodiment.

FIG. 3 is an internal structural diagram showing a state of a transfer ribbon in the label printer according to the embodiment.

[Explanation of symbols]

 1 Label Printer 24 Thermal Head 26 Platen Roller 34 Motor 51 Supply Roll 51a Roll Shaft 52 Take-Up Roll 52a Roll Shaft R Transfer Ribbon

Claims (1)

[Claims] 1. A supply roll means having back tension applying means for winding an ink ribbon around a roll shaft and applying a back tension to the ink ribbon;
Take-up roll means for winding up the ink ribbon supplied from the supply roll means, a drive means for driving the take-up roll means, and a bridge between the supply roll means and the take-up roll means A thermal head and a platen roller configured to be able to clamp the formed ink ribbon, and when the ink ribbon is being clamped, supply the ink ribbon from the supply reel means by the rotational driving force of the platen roller. And a winding device for winding the ink ribbon sent out by the platen roller on the winding roll by the driving force of the driving unit. That is greater than the winding drive force Characteristic thermal printer.