JP2000079712A - Thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely perform printing even in transporting a thermal peeling ribbon in a low speed by a method wherein the printing can be stopped even when the transporting of a wrapping film is stopped during the printing. SOLUTION: This thermal printer comprises a thermal head movement amount managing means 61 for managing a movement amount of a thermal head 3 and a printing medium movement amount managing means 62 for managing a movement amount of a wrapping film 1 and detecting a transporting speed of the wrapping film 1. It further comprises a thermal head printing control means 63 that adds a printing medium movement amount managed by the printing medium movement amount managing means 62 with a movement amount of the thermal head 3, forms a printing dot by energizing the thermal head 3 when the added value reaches a predetermined value, moves the thermal head when the transporting speed of the wrapping film 1 is less than a predetermined value and stops the thermal head to perform the printing when the transporting speed is not less than a predetermined value.

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 on a printing medium such as a packaging film by using a thermal head, and more particularly, to sealing various kinds of products with a packaging film which is intermittently transported and stopped. The present invention relates to a thermal printer suitable for use in a packaging machine.

[0002]

2. Description of the Related Art Conventionally, as a thermal printer in such a packaging machine, for example, JP-A-8-217039
Is described in Japanese Patent Application Publication No. This thermal printer is designed to take up the carbon tape unwound from the raw carbon tape with a take-up reel, and place a line thermal head and a platen roller between the raw carbon tape and the take-up reel. The carbon tape and the packaging film are arranged facing each other so as to sandwich them.

In a state in which the carbon tape and the wrapping film are superposed, power is supplied to the line thermal head while passing them between the line thermal head and the platen roller so that printing is performed on the wrapping film. I have. The feed speed of the packaging film is detected by a rotary encoder, and power is supplied to the line thermal head in synchronization with the feed speed.

Further, as a thermal printer capable of printing on a printing medium such as a sheet in a stopped state by printing while moving a thermal head,
For example, there is one described in JP-A-8-216478. In this thermal printer, a rotating disk is rotated by a drive source such as a stepping motor, so that a spindle pin implanted at a position separated by a distance r from the rotation center on the rotating disk is rotated, and the rotating shaft is rotated. The other end side of the connecting bar member whose one end is pivotally supported by the pin is reciprocated. Since the other end of the connection bar member is attached to the thermal head mounting cart, when the other end of the connection bar member is reciprocated as described above, the thermal head reciprocates accordingly.

[0005]

However, in the above-described thermal printer, the position of the line thermal head is always at a fixed position in the transport direction of the packaging film. Printing could not be performed on the packaging film. Therefore, before the printing of the printing length to be printed on the packaging film is completed, the transport of the packaging film is forcibly stopped due to a control reason on the packaging machine side or a trouble on the packaging machine side. In such a case, there is a problem that printing is completed in a state where an image to be printed (for example, manufacturing date) is halfway and cannot be visually recognized.

In such a case, in order to inspect or repair the packaging machine, the power supply of the packaging machine is once completely shut off, and after removing the cause of the trouble on the packaging machine side, the power supply is turned off again. In such a case, the feeding may be restarted while the image is in an incomplete state during the printing of the packaging film. As a result, some of the products packed by the packaging machine may be inconsistent with the image to be printed,
There was a problem that it was necessary to carry out a work such as product selection to remove it later.

In recent years, for the purpose of high-speed printing, a hot-release ink ribbon has been developed in which ink is transferred to a printing medium by peeling when the ink ribbon is melted by heat. It has been considered that such a hot-release ink ribbon is used in a printing device mounted on a packaging machine in combination with the increase in the transport speed of the packaging film due to the improvement in the processing capacity.

However, when the printing speed is lower than a predetermined printing speed due to the characteristics of the hot-release ink ribbon, the ink of the melted and softened ink ribbon is cooled by being heated by the thermal head, and the ink ribbon is removed from the ink ribbon. Ink cannot be transferred to the print medium well, resulting in poor printing. For this reason, in the case of using the hot release ink ribbon, there is a problem that printing cannot be performed at the time of starting the transport of the packaging film or at the time of the low-speed transport operation at the time of checking the setup of the packaging machine.

On the other hand, in the case of the latter thermal printer, printing can be performed by rotating the rotary disk by a driving source such as a stepping motor and reciprocating the thermal head while the packaging film is stopped. In some cases, printing cannot be performed when the packaging film is being conveyed.

That is, in the case of this thermal printer, if the packaging film is transported during printing, the relative movement speed between the packaging film and the thermal head is different from the printing conditions of the printer, so that printing cannot be performed. there were. Therefore, this thermal printer is not only inconvenient, but also incompatible with the recent increase in the packaging film transport speed due to the improvement in the processing capability of the packaging machine.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and operates at a low speed such as when starting conveyance of a printing medium such as a packaging film or when confirming the setup of a packaging machine equipped with a thermal printer. Printing can be performed reliably even when printing is performed.Before printing of the printing length to be printed on the printing medium is completed, the printing medium may be transported due to control reasons on the packaging machine side, trouble on the packaging machine side, etc. It is an object of the present invention to ensure that desired printing can be completed even when the printing stops.

[0012]

In order to achieve the above object, the present invention provides a thermal head reciprocating mechanism for reciprocating a thermal head on a print medium in a direction in which the print medium is conveyed and in a direction opposite thereto. Thermal head moving amount management means for detecting and managing the moving amount of the thermal head moving in the reciprocating direction or the thermal head unit integrally mounted with the thermal head; and a thermal head for detecting the moving amount of the print medium in the conveying direction. A print medium movement amount management unit that detects and manages by a print medium movement amount detection unit of the same type as the thermal head movement amount detection unit of the movement amount management unit; a print medium conveyance speed detection unit that detects a conveyance speed of the print medium; , A print medium movement amount managed by the print medium movement amount management means and a thermal head managed by the thermal head movement amount management means When the added value reaches a predetermined value, the thermal head is energized to form print dots, and the print medium transport speed detected by the print medium transport speed detection means is adjusted to a predetermined value. A thermal printer, comprising: a thermal head printing control means for printing by moving the thermal head when the printing speed is less than the predetermined speed and stopping and printing when the transport speed of the print medium is equal to or higher than the predetermined value.

According to this thermal printer, the movement amount of the print medium in the transport direction managed by the print medium movement amount management means and the movement amount of the thermal head managed by the thermal head movement amount management means are the same kind of movement amount. Since each is detected by the detection unit, their movement amounts can be added. Then, when each of the moving amount detecting sections detects the added amount of each of the moving amounts managed by the print medium moving amount managing means and the thermal head moving amount managing means, the thermal head print control is performed. Power is supplied to the thermal head by the means.

Therefore, even if the thermal head does not move at a constant speed, even if the transport of the packaging film during printing is stopped due to a trouble on the packaging machine side or the transport of the printing medium is stopped, Can form a fixed size, for example, a rectangular dot (FIG. 10), which is a basic pixel of a thermal head, on a print medium with high printing accuracy even if the print medium starts to move during printing. , And can form an image without stretching and disturbance.

Further, in this thermal printer, the print medium transport speed detecting means detects the transport speed of the print medium, and when the transport speed is less than a predetermined value, moves the thermal head to perform printing. Is equipped with a thermal head print control means that stops and prints the thermal head when the value is equal to or greater than the above-mentioned predetermined value. Even when the transport of the packaging film is started using a hot release ink ribbon suitable for printing, or when the low-speed transport operation is performed during the setup confirmation work of the packaging machine, move the thermal head according to the transport state of the print medium. Printing can be performed reliably.

The thermal head moving amount detecting section and the print medium moving amount detecting section are respectively encoders, and the thermal head moving amount managing means manages the number of pulses of the first pulse input from the thermal head moving amount detecting section. Preferably, the print medium movement amount management means manages the number of pulses of the second pulse input from the print medium movement amount detection unit.

With this configuration, the amount of movement of the thermal head or the thermal head unit that moves integrally with the thermal head using the encoder in the direction opposite to the direction in which the print medium is conveyed, and the direction in which the print medium is conveyed The amount of movement of the thermal head and the print medium can be easily added by simply detecting the amount of movement of the thermal head and the number of pulses of the first pulse and the number of pulses of the second pulse. Not only can you find a great amount of travel,
By monitoring the number of second pulses with time, the transport speed of the print medium can be easily detected.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. The thermal printer shown in FIG. 1 transports an ink ribbon 4 guided by ribbon guides 90 and 91 by a ribbon transport mechanism (not shown) onto a packaging film 1 as a printing medium, and a thermal head 3.
To print on the packaging film 1. In this thermal printer, a thermal head reciprocating mechanism for reciprocating the thermal head 3 on the packaging film 1 in the direction of transport of the packaging film 1 (direction of arrow K) and in the direction of arrow C opposite thereto (for details, see (Described later) 70 is provided.

The thermal printer is a member that moves in the reciprocating direction integrally with the thermal head 3 and is a member of the thermal head carriage 38 constituting the thermal head unit in the direction indicated by the arrow K (the direction in which the packaging film 1 is transported). A thermal head movement amount management means 61 for detecting and managing the movement amount in the opposite arrow C direction is provided. Further, in this thermal printer, the amount of movement of the packaging film 1 in the transport direction is determined by the film transport, which is the same type of print medium travel detector as the encoder 64 that is the thermal head travel detector of the thermal head travel controller 61. A print medium movement amount management unit 62 that detects and manages the amount by the amount detection encoder 9 is also provided.

The print medium movement amount management means 62
Manages the print medium movement amount detected by the film conveyance amount detection encoder 9 and the time required for the movement,
It also serves as a print medium transport speed detecting means for detecting the transport speed of the packaging film 1 in the transport direction.

Further, in this thermal printer, the moving amount of the packaging film 1 managed by the printing medium moving amount managing means 62 and the moving amount of the thermal head 3 managed by the thermal head moving amount managing means 61 are added. When the added value reaches a predetermined value, the thermal head 3 is energized to form print dots, and when the transport speed of the packaging film 1 detected by the print medium transport speed detecting means is less than the predetermined value. A thermal head printing control means 63 is provided for printing by moving the thermal head 3 and for stopping and printing the thermal head 3 when the transport speed of the packaging film 1 is equal to or higher than the predetermined value.

In this thermal printer, the motor 65 provided on the thermal head reciprocating mechanism 70 is selectively rotated in both the forward and reverse directions to convey the thermal head 3 in the horizontal direction in FIG. Reciprocate in the direction and the opposite direction.

The packaging film 1 is transported in the direction indicated by the arrow K by a pair of transport rollers 2. The transport roller pair 2 is provided on the side of the packaging machine on which the thermal printer is mounted. Is driven and controlled. The transport roller pair 2 may be provided in a thermal printer so as to be driven and controlled by a control device 30 described in detail later.

In FIG. 1, reference numeral 5 denotes a belt platen.
A belt 56 is provided between the platen tension rollers 53 and 54.
Is mounted so as to be rotatable in the direction of arrow J, and the packaging film 1 is pressed by the thermal head 3 on the belt surface 56a of the belt 56 so that printing is performed.

The platen tensioning rollers 53 and 54 are rotatably held on the unit case 26 by bearings 57 at both ends of respective shaft portions 53a and 54a.
As shown in FIG. 2, the belt platen 5 has a belt receiving plate 55 (FIG. 3) on the inner surface of a portion of the belt 56 corresponding to the thermal head 3 to suppress the downward bending of the belt 56 in FIG. Are omitted in the figure).

The frictional force generated when the belt 56 is pressed against the belt receiving plate 55 by the thermal head 3 is applied to one or both surfaces of the belt 56 and the belt receiving plate 55 that are in sliding contact with each other. (For example, a fluorine coating process) to reduce the amount In the belt platen 5, a belt 56 is housed in the unit case 26 together with the two platen tensioning rollers 53 and 54 in a unit state. In this unit state, a unit provided at a printing position of the thermal printer is provided. It is detachable from the mounting part.

The belt platen 5 does not have its own drive source, and is driven by the transport force of the packaging film 1 transported in the direction indicated by arrow K in FIG. 1 while contacting the belt surface 56a of the belt 56. , The belt 56 rotates in the direction indicated by the arrow J. In addition, the belt 56 may be stretched between three or more platen stretching rollers, or may be stretched between a plurality of rollers.

The control device 30 shown in FIG. 1 has a central processing unit (CPU) having various judgment and processing functions, a ROM storing each processing program and fixed data, and a RAM serving as a data memory for storing processing data. And a well-known microcomputer comprising an input / output circuit (I / O).

The controller 30 outputs a pulse signal output from the film transport amount detection encoder 9 for detecting the transport amount of the packaging film 1 from the rotation of the transport roller 50 which rotates in synchronization with the transport of the packaging film 1. At the same time, various signals output at predetermined timing from various sensors provided in each section of the thermal printer are input.

A pulse signal corresponding to the moving amount of the thermal head carriage 38 (corresponding to the moving amount of the thermal head 3) is input from an encoder 64 of the encoder unit 78, which will be described in detail later with reference to FIG. Further, the control device 30 includes a motor 65 and a thermal head 3
And a signal for driving the other various loads provided in the thermal printer at predetermined timings.

The controller 30 detects the amount of movement of the thermal head carriage 38 that moves integrally with the thermal head 3 by a pulse signal input from the encoder 64 as shown in FIG. The moving amount in the arrow C direction is managed. The control device 3
In the case of 0, the movement amount of the packaging film 1 in the transport direction (the direction indicated by the arrow K) is also detected and managed by a pulse signal input from the film transport amount detection encoder 9.

In this thermal printer, as described above, the transport amount of the packaging film 1 detected by the film transport amount detection encoder 9 and the transport direction of the packaging film 1 detected by the time required for the movement. The transport speed of the printing medium is monitored by the print medium moving amount management means 62, and when the transport speed of the packaging film 1 is less than a predetermined value (for example, the limit printing speed when using a hot-release ink ribbon), the thermal head reciprocating mechanism By rotating the motor 65 provided in the reverse direction, the thermal head 3 is rotated in the direction opposite to the rightward direction in FIG. Print length position)
To print.

After the printing is completed, the thermal head 3 is rotated in the forward direction so that the thermal head 3 is moved in the transport direction of the packaging film 1 in the left direction in FIG.
Is controlled by the thermal head print control means 63 so as to return to the position indicated by the solid line as the home position.

On the other hand, when the transport speed of the print medium is equal to or higher than the predetermined value, printing is performed in accordance with the print medium transport speed at that time while keeping the thermal head 3 at the home position shown by the solid line in FIG. Thus, the thermal head print control means 63 controls. Therefore, the control device 30
Comprises at least a thermal head movement amount management means 61;
It has the functions of a print medium movement amount management means 62 also serving as a print medium conveyance speed detection means, and a thermal head print control means 63.

Next, the thermal head reciprocating mechanism 70 will be described in detail with reference to FIGS. The thermal head reciprocating mechanism 70 includes a motor 65 fixed to a lower holding frame 76 integrally fixed to the lower surface of the upper holding frame 71 with the rotation shaft 65a facing upward, and a motor 65 fixed to the rotation shaft 65a of the motor 65. 4, a pulley 73 rotatably attached to the right end of the upper holding frame 71 in FIG. 4 corresponding to the pulley 72, and a timing belt 74 stretched between the pulleys 72 and 73. As shown in FIG.
A fixed position 91 (simplified by a single line)
And two carriage slide shafts 75
a and 75b, which can be moved in the left-right direction in the figure, and a thermal head carriage 38 holding the thermal head 3 as shown in FIG. A thermal head contact / separation mechanism (not shown), which is constituted by a head bracket 39 and the like movably attached (the detailed description is omitted because it is not directly related to the present invention).

The lower holding frame 76 is fixed to a fixing portion of the apparatus. Further, the two carriage slide shafts 75a and 75b are provided in parallel with each other, and both ends of the carriage slide shafts 75a and 75b
Each part is fixed. An encoder unit 78 is fixed to the thermal head carriage 38, and the encoder unit 78 has an encoder 64.
Is attached, and a wire 81 stretched between left and right ends of the upper holding frame 71 is wound around an encoder pulley 79 fixed to the rotating shaft.

Therefore, when the motor 65 is rotated clockwise in FIG. 5, the pulley 72 is rotated in the same direction, so that the timing belt 74 is rotated clockwise in FIG. 38 and the encoder unit 78 integrated therewith move rightward in the figure. Therefore, the thermal head carriage 3
8, the thermal head 3 mounted via the head bracket 39 as shown in FIG. 4 also moves in the same direction.

At this time, when the encoder unit 78 moves rightward in FIG. 4, the encoder pulley 79 provided there is rotated by the wire 81 wound therearound. Therefore, a pulse signal corresponding to the moving amount of the encoder unit 78 is sent from the encoder unit 78 (more precisely, the encoder 64 provided there) to the thermal head moving amount managing means 61 (FIG. 1) of the control device 30. Output.

When the motor 65 is rotated in the counterclockwise direction in FIG. 5, the timing belt 74 rotates in the counterclockwise direction in FIG. 38 and the encoder unit 78 move to the left in the figure, and the thermal head 3 also moves in the same direction.

When the thermal head 3 moves together with the thermal head carriage 38 to the home position which is the printing start position shown in FIG. 5, the thermal head carriage 38 is moved to the carriage home position sensor (for example, a transmission type photo sensor) shown in FIG. ) 95 detects,
As a result, the rotation of the motor 65 is stopped, and the thermal head carriage 38 stops at the home position (print start position) shown in FIG.

The thermal head print control means 63 of the control device 30 rotates the motor 65 in the clockwise direction in FIG. 5 by a moving amount at which the thermal head 3 (see FIG. 6) performs predetermined printing. Accordingly, the timing belt 74 stretched between the pulleys 72 and 73 rotates clockwise in FIG.
The encoder and the encoder unit 78 are moved rightward in FIG. 5, whereby the thermal head 3 is moved in the same direction by the predetermined print dots via the head bracket 39 shown in FIG. The desired print is performed by causing the thermal head 3 to generate heat.

At this time, the thermal head 3 shown in FIG.
The amount of movement in the direction is managed by inputting the number of first pulses output by the encoder 64 with the movement to the thermal head movement amount management means 61. The movement of the packaging film 1 in the direction indicated by the arrow K in FIG. 1 is controlled by changing the number of pulses of the second pulse output from the film transport amount detection encoder 9 in accordance with the transport of the packaging film 1 by moving the print medium. This is performed by inputting to the quantity management means 62.

In this thermal printer, when printing of a predetermined length by the thermal head 3 is completed, immediately after that, the motor 65 is rotated counterclockwise in FIG. 5 to rotate the thermal head carriage 38 and the encoder unit 78 together. In the figure, the carriage 65 is moved to the left, and when the carriage home position sensor 95 is turned on after detecting the return of the thermal head carriage 38 to the printing start position (coincident with the home position), the rotation of the motor 65 is stopped. At this time, the thermal head 3 is at the position indicated by the imaginary line on the left side of FIG.

This thermal printer is mounted on, for example, a packaging machine that packs a product with the packaging film 1, and the packaging film 1 of the packaging machine is subjected to a seam (heat welding) process of the packaging film 1 covering the product. The transport system (for example, the transport roller pair 2 shown in FIG. 1) for transport is intermittently stopped for a short time, and during the stop time, the thermal head 3 of the thermal printer prints the manufacturing date and the like,
A case will be described in which the drive of the transport system is restarted immediately after the seam process is completed in order to seam the next product.

First, the packaging machine equipped with the thermal printer shown in FIG. 1 is driven to start the operation of packing the product with the packaging film 1. The transport roller pair 2 on the packaging machine side is driven based on a preset transport program, and transports the packaging film 1 intermittently in the direction of arrow K while taking a predetermined pause time (seam process).

In this thermal printer, when a predetermined pause portion (seam portion) of the packaging film 1 comes to the seam process of the packaging machine, the thermal head 3 of the thermal printer is shown together with the thermal head carriage 38 in FIG. It is located at the home position, which is the printing start position, and is incorporated in the packaging machine so that the date of manufacture and the like can be printed on the printed portion of the packaging film 1.

The packaging film 1 is transported by the transport roller pair 2 shown in FIG. 1, and the portion to be printed (the date printed on the date of manufacture) of the packaging film 1 is at the home position shown by the solid line in FIG. When the thermal head 3 stops at the position of the thermal head and the thermal head contact / separation mechanism (not shown) moves the thermal head 3 from the retracted position to the pressing position (the virtual line portion in FIG. 6) shown in FIG. The motor 65 is rotated clockwise in FIG. 5, and the thermal head 3 is moved to the right in FIG. 6 by the amount of the printing portion which is the printing length. Here, the manufacturing date as characters actually formed as print dots in the print portion is printed by the thermal head print control means 63 controlling the thermal head 3.

As described above, the timing belt 74 stretched between the pulleys 72 and 73 by the rotation of the motor 65 rotates clockwise in FIG. 5 moves rightward in FIG. 5, whereby the thermal head 3 is moved by the predetermined print length in the same direction via the head bracket 39 shown in FIG. In order to print each print dot on the first line as a character, the thermal head 3 is controlled to be energized.

Next, the thermal head 3 is moved in order to print each print dot on the second line as a character, and the encoder unit 78 for detecting the amount of movement of the thermal head 3 moves with the movement of the thermal head 3. In this embodiment, as shown in FIG. 7, when four pulses of one encoder pulse movement amount P1 are output, the dimension of the thermal head movement direction reaches one print dot pulse movement amount P0 which is the same as the thermal head basic pixel. When it is determined that the thermal head 3 is energized, the thermal head print control means 63
Is controlled by

In the same manner, the thermal head print control means 63 controls the printing so that each dot of the number of lines required as a character is printed during the movement of the thermal head 3 for the printing length as a printing portion. You. The movement of the thermal head 3 by the motor 65 includes acceleration and deceleration regions as shown in FIG. 8, but even if the region is not in the constant speed region, one print is consequently output when one encoder pulse movement amount P1 is output by four pulses. By energizing the thermal head 3 which reaches the dot pulse movement amount P0, an image can be formed on the packaging film 1 without shifting one print dot unit.

Each dot in one line is controlled by selectively energizing each heating element arranged in a direction perpendicular to the direction of transport of the print medium of the thermal head 3 in accordance with print data. Further, in this embodiment, the resolution is set such that four pulses of one encoder pulse movement amount P1 are output for one printing dot pulse movement amount P0. However, if the resolution is increased, the printing accuracy may be further improved. Of course.

When printing by the movement of the thermal head 3 is completed, the motor 65 is reversely rotated counterclockwise in FIG. 5 to move the thermal head carriage 38 and the encoder unit 78 to the left in FIG. When the position sensor 95 is the thermal head carriage 38
When the return to the home position (coincident with the print start position) is detected and turned on, the rotation of the motor 65 is stopped.
At this time, the thermal head 3 is at the position indicated by the imaginary line on the left side in FIG. 6, and when the seam process of the packaging machine is completed, the packaging film 1 is transported again in the direction indicated by the arrow K in FIG.

As described above, the pulse signal output from the encoder 64 by the movement of the thermal head 3 is such that when the encoder pulse movement amount P1 is output as four pulses as shown in FIG. It is set so that one print dot pulse movement amount P0 is the same as the basic pixel. In this case, printing is performed while the thermal head 3 moves on the wrapping film 1 which is stopped (the transport speed becomes less than a predetermined value). When output, the thermal head print control means 63 controls so that the thermal head 3 is energized.

Further, in this embodiment, the output from the film transport amount detection encoder 9 for detecting the transport amount of the packaging film 1 is exactly the same as the method of setting the number of pulses in the management of the moving amount of the thermal head 3 described above. The pulse signal to be transmitted is represented by one encoder pulse movement amount P2 as shown in FIG.
Are output so that the amount of movement of the wrapping film 1 is equal to the amount of movement of one print dot pulse P0, which is the same as the basic pixel of the thermal head.

Therefore, in this thermal printer,
As described above, when the transport speed of the packaging film 1 is equal to or higher than the predetermined value, printing is started by the stopped thermal head 3 on the transported packaging film 1. The thermal head print control means 6 supplies power to the thermal head 3 when one encoder pulse movement amount P2 is output for four pulses.
3 controls.

Further, when printing is performed by moving the thermal head 3 while the packaging film 1 is being conveyed (provided that the conveying speed is less than a predetermined value), the output of the thermal head movement amount managing means 61 (in this case, P1 ) And the output (P2 in this case) from the print medium movement amount management means 62 are added by the thermal head print control means 63, and when the added encoder pulse P1 + P2 is counted for four pulses as shown in FIG. 11, it is determined that the relative movement amount between the thermal head 3 and the packaging film 1 has reached the same one print dot pulse movement amount P0 as the thermal head basic pixel.
At the fourth pulse of P2, the thermal head print control means 63 controls so that the thermal head 3 is energized at the timing of PR1, PR2, PR3, PR4 for the next print dot.

Next, a case where printing is performed on the packaging film 1 by using a hot-release ink ribbon suitable for high-speed printing as the ink ribbon 4 shown in FIG. 1 will be described. In this case, while the packaging film 1 shown in FIG. 1 is being transported, the ink ribbon 4, which is a release ink ribbon when heated, is transferred onto the packaging film 1 by a ribbon transport mechanism (not shown).
The print medium is conveyed while being guided by 0 and 91, and printing is controlled by the thermal head print control means 63.

At this time, a film transport amount detecting encoder 9 for detecting the transport amount of the packaging film 1 by the rotation of the transport roller 50 that rotates in synchronization with the transport of the packaging film 1.
The printing medium movement amount management means 62 has a function of counting the pulse signals input within a predetermined time based on the pulse signals output from the printer, so that the conveyance of the packaging film 1 as the printing medium conveyance speed detecting means is performed. Monitor speed.

In this thermal printer, the transport speed of the packaging film 1 monitored by the print medium moving amount management means 62 is set at a predetermined transport speed when the transport of the packaging film 1 is started or at the time of the low-speed transport operation at the time of checking the setup of the packaging machine. (Predetermined value)
If it is less than the predetermined value, the thermal head print control means 63 of the control device 30 rotates the motor 65 clockwise in FIG. 5 to start moving the thermal head 3. The output from the print medium movement amount management means 62 (P2 in this case) and the output from the thermal head movement amount management means 61 (P2 in this case)
1) is added by the thermal head print control means 63, and when the added encoder pulse P1 + P2 is counted for four pulses as shown in FIG. 11, the relative movement dimension between the thermal head 3 and the packaging film 1 is determined by the thermal head. When it is determined that the amount of movement of one print dot pulse P0, which is the same as that of the basic pixel, has been reached, the thermal head print control means 63 controls the thermal head 3 to supply current.

Thus, even if the transport speed of the packaging film 1 is lower than the predetermined transport speed, the thermal head 3 moves and performs printing, so that the hot-release ink ribbon printed and thermally fused by the thermal head 3 is used. Since the printing is performed while the print 4 is immediately peeled off, there is no possibility that the ink is surely transferred to the packaging film 1 and printing failure does not occur.

As described above, the print medium movement amount management means 62
When the transport speed of the packaging film 1 monitored by the controller becomes lower than the predetermined transport speed, the thermal head print control means 63 of the control device 30 rotates the motor 65 in the clockwise direction in FIG. With the configuration for printing, even if the transport of the packaging film 1 is suddenly stopped during printing due to a control reason on the packaging machine side or a trouble on the packaging machine side, the packaging film 1 stops. When the immediately preceding conveyance speed is lower than the predetermined conveyance speed, printing can be performed by moving the thermal head 3 until printing for the printing length on the packaging film 1 is completed. An image without disturbance can be formed, and the printing can be surely completed.

FIG. 12 is a flowchart showing these printing operations. Note that the flowchart of FIG. 12 shows an example in which characters and the like are printed on only one line in order to keep the description simple. When the flowchart of FIG. 12 starts, first, in step 1, it is determined whether or not the thermal head 3 is at the home position, based on whether or not the carriage home position sensor 95 detects the thermal head carriage 38 and is on. Therefore, if the carriage home position sensor 95 is not turned on, the process waits as it is, and if it is turned on, the process proceeds to step 2.

In step 2, it is determined whether or not a print command has been issued. If not, the process waits as it is. If the command has been issued, the process proceeds to step 3 in which the thermal head 3 prints the first line. To start. In the next step 4, it is determined whether or not the transport speed of the packaging film 1 has fallen below a predetermined transport speed, that is, whether or not the transport speed is less than a predetermined value. Therefore, if the determination is NO because the transport speed of the packaging film 1 is equal to or higher than the predetermined value, the process proceeds from step 12 to step 6, but if the transport speed is less than the predetermined value, the process proceeds to step 5 to move the thermal head 3 ( 1 (moving to the right in FIG. 1). In addition,
The determination of the transport speed of the packaging film 1 in step 4 is performed based on the transport speed of the packaging film 1 monitored by the print medium moving amount management unit 62.

In the next step 6, 1 is output from the encoder unit 78 with the movement of the thermal head 3.
The counting of the encoder pulse movement amount P1 is started. Then, in step 7, counting of one encoder pulse movement amount P2 output from the film conveyance amount detection encoder 9 when the packaging film 1 moves is started. In step 7, when the packaging film 1 is stopped, the movement amount P2 output from the film conveyance amount detection encoder 9 is 0 (zero).

In the next step 8, the pulse movement amount P
It is determined whether or not 1 + P2 has reached a predetermined value. If the value has not yet reached the predetermined value, the flow returns to step 4 described above, and the determination and processing after step 4 are repeated. If the pulse movement amount P1 + P2 has reached a predetermined value, step 9
Then, printing of the next line by the thermal head 3 is started.

In the next step 10, it is determined whether or not a predetermined print length has been printed, that is, in this example, whether or not printing of one line of characters or the like has been completed, and if printing of one line has not been completed yet. For example, the above-described determination and processing after step 4 are repeatedly performed. If it is determined in step 10 that the printing of the predetermined printing length has been completed, the process proceeds to step 11, and the thermal head 3 is moved in the reverse direction until the carriage home position sensor 95 described in FIG. (Left direction in FIG. 5), the thermal head 3 is moved to the home position, and the processing of this routine is ended.

In the flowchart of FIG. 12,
For example, when printing is started, the packaging film 1 is in a stopped state and the process proceeds to step 8. When the process returns to step 4 because the pulse movement amount P1 + P2 has not yet reached the predetermined value, the printing is still in progress. If the transport of the packaging film 1 has been started at the same timing, if the transport speed of the packaging film 1 is equal to or higher than a predetermined transport speed at that time, the process proceeds to step 12, where the movement of the thermal head 3 is stopped, After that, the processing and the judgment after step 6 are performed.

Although the embodiment of the thermal printer using the ink ribbon 4 has been described above, the ink ribbon 4 may be the above-described hot-release ink ribbon or a normal ink ribbon. Is also good. Further, the thermal printer according to the present invention is a direct thermal printing apparatus in which a printing portion of a packaging film 1 as a printing medium is subjected to a thermal coating process, and printing can be performed directly only by pressing the thermal head 3 and energizing. The effect of the present invention can be obtained as a thermal printer regardless of such a printing method. Further, in the above-described embodiment, the case where the thermal head basic pixel is a square rectangular dot has been described. However, the present invention is not limited to this. Good.

[0069]

As described above, according to the thermal printer of the present invention, the reason for control on the packaging machine side or the packaging machine before the printing of the printing length to be printed on the packaging film is completed. If the transport of the packaging film is stopped due to troubles on the side, etc., or a low-speed transport operation was performed when starting the transport of the packaging film or checking the setup of the packaging machine using a hot release ink ribbon suitable for high-speed printing Even in this case, printing can be reliably completed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a thermal printer according to the present invention.

FIG. 2 is a configuration diagram showing a belt platen provided in the thermal printer in a partially sectional state.

FIG. 3 is a perspective view showing a state in which the belt platen is formed in a unit shape.

FIG. 4 is a schematic configuration diagram viewed from the front for describing a thermal head reciprocating mechanism provided in the thermal printer of FIG. 1;

FIG. 5 is a schematic configuration diagram illustrating the thermal head reciprocating mechanism similarly viewed from a plane.

FIG. 6 is a schematic view from the front showing a moving range of the thermal head moved by the reciprocating mechanism of the thermal head.

FIG. 7 is a diagram illustrating a movement amount of one encoder pulse of the thermal head and a movement amount of one print dot unit.

FIG. 8 is a diagram showing a relationship between a time required for accelerating a thermal head from a stop position, moving at a constant speed, decelerating and stopping, and a thermal head moving speed.

FIG. 9 shows one encoder pulse movement amount and one of the packaging film.
FIG. 5 is a diagram illustrating a movement amount in print dot units.

FIG. 10 is a diagram illustrating an image when the thermal head is moved and printed at equal intervals in the moving direction of the thermal head by the length of a basic pixel length of the thermal head.

FIG. 11 is a diagram for explaining the relationship between the output timing of each encoder pulse relative to the relative movement of the packaging film and the thermal head and the printing timing of one print dot at that time.

FIG. 12 is a flowchart showing a printing operation when printing one line of characters or the like on a printing medium.

[Explanation of symbols]

1: Packaging film (print medium) 3: Thermal head 9: Film transport amount detection encoder (print medium movement amount detection unit) 30: Control device 38: Thermal head carriage 61: Thermal head movement amount management means 62: Print medium movement amount Management means (print medium transport speed detection means) 63: thermal head print control means 64: encoder (thermal head movement amount detection unit) 65: motor 70: thermal head reciprocating movement mechanism

Continued on front page F-term (reference) 2C064 CC02 CC06 CC11 EE02 2C065 AA01 AB01 AD07 AF01 AF02 CC26 DA02 DA03 DA34 DA38 2C087 AA09 AC01 AC05 3E056 AA01 DA01 FA01 GA04

Claims (2)

[Claims] 1. A thermal head reciprocating mechanism for reciprocating a thermal head on a print medium in a direction in which the print medium is conveyed and in a direction opposite to the thermal medium, and the thermal head or the thermal head moving in the reciprocal direction. A thermal head movement amount management unit that detects and manages the movement amount of the integrally mounted thermal head unit, and a thermal head movement amount detection unit of the thermal head movement amount management unit that determines the movement amount of the print medium in the transport direction. A print medium movement amount management unit that detects and manages the same type of print medium movement amount detection unit, a print medium conveyance speed detection unit that detects the transfer speed of the print medium, and the print medium movement amount management unit By adding the moving amount of the printing medium and the moving amount of the thermal head managed by the thermal head moving amount management means, When the addition value reaches a predetermined value, the thermal head is energized to form print dots, and the thermal head is moved when the print medium transport speed detected by the print medium transport speed detecting means is less than a predetermined value. And a thermal head print control means for stopping the thermal head when the transport speed of the print medium is equal to or higher than the predetermined value and performing printing. 2. The thermal head moving amount detecting section and the print medium moving amount detecting section are encoders, respectively, and the thermal head moving amount managing means includes a pulse of a first pulse inputted from the thermal head moving amount detecting section. 2. The thermal printer according to claim 1, wherein the number is controlled, and the print medium movement amount management unit manages the number of second pulses input from the print medium movement amount detection unit.