JPH11268388A - Thermal transfer printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save a ribbon even when a printing medium is printed at high speeds, while the ribbon is being conveyed in a stable manner. SOLUTION: There are provided a thermal head 3, a ribbon conveying roller 6 which conveys a ribbon 4 at the same conveying speed as a pair of conveying rollers 2, a ribbon connect-disconnect mechanism 10 which presses the ribbon 4 against the roller 6 or releases the ribbon therefrom, and a printing part moving mechanism 20. If the pair of rollers 2 is driven, the ribbon 4 is pressed against the rotating roller 6, and the thermal head 3 is moved to a printing position by the mechanism 20, a packaging film 1 can be printed desirably. When one unit of printing is completed, the ribbon 4 is released from the roller 6, and the head 3 is retracted, whereby only the film 1 is conveyed so that the ribbon can be saved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printing apparatus for printing on a printing medium using a ribbon, and more particularly to a thermal transfer printing apparatus suitable for a case where a ribbon saving function is provided.

[0002]

2. Description of the Related Art Conventionally, as such a thermal transfer printing apparatus, there is one described in, for example, Japanese Utility Model Publication No. Sho 62-41809. When the printing is completed, the thermal transfer printing apparatus separates the ink sheet (ribbon) from the plain paper as a printing medium and returns the ink sheet by a predetermined amount in a direction opposite to a conveying direction at the time of printing. The portion of the ink sheet corresponding to the white portion of the plain paper (the portion on which no printing is performed) is prevented from being wasted.

Further, in the thermal transfer printing apparatus described in Japanese Patent Publication No. 2-59068, a feed-back roller is provided in a transport path of a thermal transfer film (ribbon), and a base paper (print medium) on which visual information is printed is provided. After the polymer with the heat-sensitive transfer film passes through the separation roller for separating the base paper and the heat-sensitive transfer film, the separation roller is driven so as to reversely feed the heat-sensitive transfer film by a predetermined amount.

[0004]

However, in this type of conventional thermal transfer printing apparatus, when printing portions are continuously formed on a printing medium at predetermined intervals along a conveying direction thereof, each printing portion is formed. Since the operation of returning the ribbon by a predetermined amount in the reverse direction is repeated each time printing of a portion is completed, if the printing speed is increased, there is a problem that the return process of the ribbon cannot follow the printing speed.

[0005] In particular, in the case of a normal label printer,
The transport speed of the printing medium is about 100 mm / sec. For example, in the case of a thermal transfer printing apparatus used for various packaging, the above transport speed is required to be high-speed transport of about 500 to 600 mm / sec. In such a conventional thermal transfer printing apparatus, desired printing cannot be performed while performing ribbon save. Even when the printing medium is transported at a slow speed, the ribbon is rewound by a predetermined amount every time printing is performed when the ribbon is saved by the above-described conventional thermal transfer printing apparatus. Was likely to be unstable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. Even when a printing medium is conveyed at a high speed and high-speed printing is performed, a ribbon save (a little unused portion is left on the ribbon). (Economic use), and at the same time, stably transport the ribbon.

[0007]

In order to achieve the above object, the present invention provides a printing unit for printing on a print medium conveyed in a conveyance direction at the time of printing by a print medium conveyance means for conveying a print medium, A ribbon transport means driven so as to be able to transport the ribbon at the same transport speed as the medium transport means, and a printing medium which is brought into pressure contact with the ribbon being transported by the ribbon transport means by the transport force of the ribbon transport means. And a ribbon contacting / separating means for transporting the ribbon in the transporting direction at the time of printing and releasing the ribbon from being pressed against the ribbon transporting means.

When the ribbon is pressed against the ribbon transfer means by the ribbon transfer means, the printing section is moved to the printing position, and when the ribbon is released from the pressure contact with the ribbon transfer means. A printing unit moving means for moving the printing unit from the printing position to the retracted position.

With this arrangement, when the print medium is being conveyed in the conveyance direction at the time of printing by the print medium conveyance means, the ribbon is brought into pressure contact with the driving ribbon conveyance means by the ribbon contact / separation means, and the ribbon conveyance is performed. If the printing medium and the ribbon are conveyed in the conveying direction at the time of printing by the conveying force of the means, the printing medium and the ribbon are conveyed at the same conveying speed in a state of being overlapped. Therefore, in this state, predetermined printing can be performed on the printing medium by the printing unit.

When the printing section finishes printing of a predetermined length, the ribbon contact / separation means releases the pressure contact of the ribbon with the ribbon conveyance means, so that the ribbon receives a conveyance force from the ribbon conveyance means. Since it disappears, the conveyance is stopped. At that time, the ribbon transport unit is continuously driven at the same transport speed as the print medium transport unit without stopping.

On the other hand, the print medium is continuously transported in the transport direction at the time of printing by the print medium transport means. If the ribbon is brought into pressure contact with the driving ribbon transporting means by the ribbon contacting / separating means, the print medium and the ribbon are transported again at the same transport speed in the transport direction during printing. At the same timing, the printing unit moving means moves the printing unit to the printing position, superimposes the printing medium on the ribbon, and performs the next printing on the printing medium by the printing unit. Printing can be continuously performed by economical ribbon save without leaving.

In addition, since the ribbon transport means continues to be driven at the same transport speed as that of the print medium transport means without stopping even between the printing portion where no printing operation is performed and the next printing portion. Even when printing on a print medium at high speed, if the ribbon is pressed against the ribbon transfer means being driven by the ribbon contact / separation means, the transfer speed of the print medium transfer means and the ribbon from the moment of the pressure contact. They can be transported at the same transport speed. Therefore, compared to the case where the ribbon transport unit is driven from the stop state, there is no waste in the rising time until the ribbon transport unit reaches the same transport speed as the transport speed of the print medium transport unit.

In the above thermal transfer printing apparatus, the print medium transport amount detecting means for detecting the transport amount of the print medium and the ribbon contact / separation means are operated when the transport amount detected by the means reaches a predetermined value. It is preferable to provide means for bringing the ribbon into pressure contact with the ribbon transport means being driven, and operating the printing section moving means to move the printing section to the printing position.

In this case, the transport amount of the print medium can be accurately detected by the print medium transport amount detecting means. Therefore, when the conveyance amount detected by the printing medium conveyance amount detecting means reaches the predetermined value corresponding to the interval between the printing portion and the next printing portion each time printing of one unit is completed, the ribbon contact / separation means , The ribbon can be pressed against the driving ribbon transport means to transport it in the transport direction during printing at the same transport speed as the transport speed of the print medium. Therefore, even in the case of high-speed conveyance, it is possible to continuously perform printing with an accurate interval between a printing portion and the next printing portion.

Further, in any one of the thermal transfer printing apparatuses described above, a driving force for driving the ribbon conveying means is transmitted to a ribbon winding section for winding the ribbon after being used for printing, and the ribbon is rotated. A drive force transmitting mechanism for interrupting transmission is provided, and when the ribbon is pressed against the ribbon conveying means by the ribbon contact / separation means, the drive force transmitting mechanism is moved to a position at which the drive force is transmitted to the ribbon winding unit. It is preferable to provide a driving force contact / separation mechanism for setting the driving force transmission mechanism to a position where the transmission of the driving force is interrupted when the pressure contact with the ribbon transport means is released.

With this configuration, the ribbon take-up section can be rotated by the driving force of the ribbon transfer section, and the ribbon used for printing can be taken up by the ribbon take-up section. And the drive source of the ribbon winding section can be shared.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a configuration of a packaging printer which is a thermal transfer printing device according to the present invention.

The packaging printer as the thermal transfer printing apparatus includes a pair of transport rollers 2 (printing medium transport means for transporting a packaging film 1 as a printing medium). The thermal head 3 is a printing unit that prints on the belt platen 5 on the packaging film 1 conveyed to the left in FIG. And a ribbon transport roller 6 which is a ribbon transport means that is driven to rotate in the direction of arrow A so that the ribbon 4 can be transported at the same transport speed as the transport speed of the transport roller pair 2.

The packaging printer is provided with a contact / separation roller 7.
Is moved to a position shown by a virtual line in FIG.
The ribbon 4 is pressed against the ribbon transport roller 6 rotating in the direction indicated by the arrow A, and the ribbon 4 is transported in the transport direction during printing of the packaging film 1 by the transport force of the ribbon transport roller 6, or the ribbon of the ribbon 4 Ribbon contact / separation mechanism 1 which is a ribbon contact / separation means for releasing pressure contact with conveyance roller 6
0 (detailed description will be described later).

Further, in this packaging printer, when the ribbon 4 is pressed against the ribbon transport roller 6 by the ribbon contact / separation mechanism 10, the thermal head 3 is moved to the printing position, and the pressure contact of the ribbon 4 against the ribbon transport roller 6 is released. A printing unit moving mechanism 20, which is a printing unit moving means for moving the thermal head 3 from the printing position to a retracted position above the printing position when the contact / separation roller 7 is moved to the position shown by the solid line in FIG. ing.

The packaging printer also receives a speed detector 9 for detecting the transport speed of the packaging film 1 from the rotation of the transport roller 50, and inputs a signal corresponding to the transport speed of the packaging film 1 from the speed detector 9. A control device 30 for controlling the driving of the ribbon winding motor 22 at a rotational speed such that the transport speed of the packaging film 1 and the transport speed of the ribbon 4 are equal to each other. 6 is rotated in the direction of arrow A.

That is, the belt drive pulley 31 is fixed to the rotation shaft 22 a of the ribbon winding motor 22, and the pulley 11 is fixed to the support shaft of the ribbon transport roller 6. Then, a timing belt 21 is stretched between the belt driving pulley 31 and the pulley 11, and the timing belt 21 is provided so as to be connectable and separable to a driving force transmission chuck 43 integrally fixed to the ribbon winding core 12. The ribbon take-up pulley 27 and the idle pulley 13 are also extended.

Therefore, when the ribbon winding motor 22 is rotated, the belt driving pulley 31 is rotated, whereby the pulley 11, the ribbon winding pulley 27, and the idle pulley 13 are rotated by the rotating timing belt 21, and the ribbon driving pulley 31 is rotated. The transport roller 6 rotates in the direction of arrow A.

The control unit 30 includes a central processing unit (CPU) having various judgment and processing functions, a ROM storing each processing program and fixed data, a RAM serving as a data memory for storing processing data, and an input / output circuit. (I / O). The control device 30 receives a signal corresponding to the transport speed of the packaging film 1 from the speed detector 9 and various signals output at predetermined timing from various sensors provided in each section of the packaging printer. Enter each.

The control device 30 includes a drive system (not shown) for driving the transport roller pair 2, a ribbon winding motor 22, and a solenoid 25 provided in the ribbon contact / separation mechanism 10, which will be described later. And various signals for driving them are output at predetermined timings. Also, with respect to other various loads provided in the packaging printer, signals for driving them are output at predetermined timings. Note that the ribbon 4 is fed out from the ribbon supply core 8, and the ribbon guide roller 3
3 while being wound on the ribbon winding core 12.

Further, in the packaging printer, a driving force of a ribbon winding motor 22 for driving the ribbon transport roller 6 is applied to a ribbon winding core 12 serving as a ribbon winding section for winding the ribbon 4 used for printing. Through a driving force transmission chuck 43 to rotate the transmission or to cut off the transmission of the driving force (to be described in detail later).
Is provided.

In the packaging printer, when the ribbon 4 is pressed against the ribbon transport roller 6 by the ribbon contact / separation mechanism 10, the driving force transmission mechanism 40 is connected to the ribbon winding motor 22.
At a position where the driving force is transmitted to the ribbon take-up core 12, and the driving force transmission mechanism 40 is set at a position where the transmission of the driving force is interrupted when the pressing of the ribbon 4 against the ribbon transport roller 6 is released. A driving force contact / separation mechanism 60 is provided.

The ribbon contact / separation mechanism 10 includes a contact / separation roller 7,
A swing arm 15 that rotatably holds the contact / separation roller 7 at one end thereof and has a substantially center portion swingably supported by a shaft 14.
An intermediate arm 16 rotatably attached to the other end of the swing arm 15, and a drive attached to the intermediate arm 16 and capable of moving by a predetermined amount along the longitudinal direction of the intermediate arm 16. An arm 17, a crank arm 19 swingably supported by a fulcrum shaft 18, and a solenoid connecting arm rotatably attached to an upper end of the crank arm 19 by a pin together with an end on one end of the drive arm 17. 1, and a solenoid 25 having a plunger 25a rotatably attached to the left end of the solenoid connecting arm 24 in FIG.

As shown in FIG. 2, the intermediate arm 16 is formed with two long holes 16a and 16b at intervals in the longitudinal direction, and a stepped pin 28 is provided in the long hole 16a and a step is provided in the long hole 16b. The stepped pins 29 which are shorter than the stepped pins 28 are fitted respectively, and the stepped pins 28 and 29 are
7 are fixed to the drive arms 17 by fitting them into the holes formed in the holes 7 and caulking the ends thereof.

Then, the right end of the intermediate arm 16 in FIG. 2 is bent to form a spring receiver 16c, and a spring 32 is mounted between the spring receiver 16c and the stepped pin 28. As shown in FIG. 2, the stepped pin 28 abuts on the right edge of the elongated hole 16a and the stepped pin 29 abuts on the right edge of the elongated hole 16b. Therefore, when the drive arm 17 is moved to the left in FIG. 2 while the intermediate arm 16 is restrained, the spring 32 is extended by an amount corresponding to the movement of the drive arm 17.

The main body of the solenoid 25 of the ribbon contact / separation mechanism 10 shown in FIG. 1 is fixed to a fixing portion of the packaging printer. When the solenoid 25 is turned on, the plunger portion 25a moves leftward in FIG. 1 and the solenoid connecting arm 24 moves leftward. As a result, the crank arm 19 swings about the fulcrum shaft 18 in the counterclockwise direction in FIG.

Then, the drive arm 17 is moved to the intermediate arm 16.
1, the swing arm 15 rotates clockwise in FIG. 1 with the shaft 14 as a fulcrum, and the contact / separation roller 7 comes into pressure contact with the ribbon transport roller 6 via the ribbon 4. At this time, even after the contact / separation roller 7 comes into contact with the ribbon transport roller 6 via the ribbon 4, the drive arm 17 is slightly pushed to the left in FIG.
The ribbon 4 is absorbed by the extension, and the ribbon 4 is pressed against the ribbon transport roller 6 by the contact / separation roller 7 with a predetermined pressure suitable for transport of the ribbon 4.

The printing unit moving mechanism 20 includes a solenoid 25, a solenoid connecting arm 24, a fulcrum shaft 18, and various parts of the crank arm 19 which also serve as the ribbon contacting / separating mechanism 10, and one end rotatably supported by a supporting shaft 34. 1, a presser plate urging spring 36 for urging the head presser plate 35 upward in FIG. 1, and the head presser plate 35 attached to the head presser plate 35 via a connecting member 41. A spring absorbing mechanism 37 for absorbing downward movement of
A holding member 38 for holding the spring absorbing mechanism 37 movably in the vertical direction, and a head bracket 39 for fixing the thermal head 3 and held movably in the vertical direction by the holding member 38.

The printing unit moving mechanism 20 includes a solenoid 2
When the ribbon 5 is turned on and the ribbon 4 is pressed against the ribbon transport roller 6, the crank arm 19 rotates counterclockwise about the fulcrum shaft 18 from the position shown in FIG. 35, the right end side is pressed down against the urging force of the presser plate urging spring 36.

As a result, since the connecting member 41 is pushed down, the head bracket 39 is pushed down via the spring absorbing mechanism 37, and the thermal head 3 is pushed onto the belt platen 5 via the ribbon 4 and the packaging film 1. When the thermal head 3 is pressed down, the spring absorbing mechanism 37 is appropriately compressed to absorb the downward movement amount of the connecting member 41. The platen 5 is brought into pressure contact with a predetermined pressure suitable for printing.

The driving force transmission mechanism 40 includes a belt driving pulley 31, a timing belt 21, and a ribbon winding pulley 2.
7, a driving force transmitting chuck 43 to which a rotational force is transmitted from the ribbon winding pulley 27 at the time of connection, and a ribbon winding core integrally fitted and fixed to the driving force transmitting chuck 43 as shown in FIG. 12 and a shaft 47.

The driving force contact / separation mechanism 60 can swing in the direction of arrow B in FIG. 4 by pivotally supporting the shaft portions 44a and 44b (see FIG. 1) formed at both ends. The swing arm 45, a slide plate 46 that swings the swing arm 45 in a direction indicated by an arrow C in FIG. 1 and a direction opposite to the direction indicated by the arrow C, a solenoid 25 serving also as the printing unit moving mechanism 20, and And a solenoid connecting arm 24.

When the ribbon 4 is pressed against the ribbon conveying roller 6 by the ribbon contact / separation mechanism 10, the driving force contact / separation mechanism 60 causes the driving force transmission mechanism 40 to receive the driving force from the ribbon winding motor 22. When the belt 4 is moved to the ribbon take-up core 12 via the belt driving pulley 31, the timing belt 21, the ribbon take-up pulley 27, and the driving force transmitting chuck 43, and the pressing of the ribbon 4 against the ribbon transport roller 6 is released. Then, the driving force transmission mechanism 40 is set to a position where the transmission of the driving force is cut off.

The slide plate 46 is substantially L-shaped as shown in FIG.
In this figure, long holes 46b and 46c having the left-right direction as a longitudinal side in FIG.
The pins 48 are fitted into the long holes 46b and 46c, respectively, so that the pins 48 can be moved only in the direction of arrow C and in the direction opposite to the direction of arrow C. An inclined portion 46a as shown in FIG. 3 is formed at the tip of the slide plate 46.

The ribbon take-up pulley 27 is fixed to a shaft 47 as shown in FIG. 4, and rotates around the shaft 47. The right side of the ribbon take-up pulley 27 in the figure is formed in a tapered shape.
A large number of teeth 27a are formed on the tapered surface in a bevel gear shape at equal intervals over the entire circumference. A driving force transmitting chuck 43 is rotatably fitted on the shaft 47, and the left side surface of the driving force transmitting chuck 43 in FIG. 4 has a concave taper corresponding to the taper surface of the ribbon winding pulley 27. A large number of teeth 43a meshing with the teeth 27a on the ribbon take-up pulley 27 are formed on the tapered surface at equal intervals in the circumferential direction.

In a normal state, the ribbon take-up pulley 27 is urged leftward in FIG.
It is separated from the driving force transmission chuck 43 as shown in the figure (the position where the transmission of the driving force is cut off). Therefore, in this state, the ribbon take-up pulley 27 is
1, the driving force is not transmitted from the ribbon winding pulley 27 to the driving force transmitting chuck 43.

The upper end of the swing arm 45 is always in contact with the back surface of the ribbon take-up pulley 27, and one end edge 45a of the lower end of the swing arm 45 shown in FIG. 46a. Therefore, when the solenoid 25 shown in FIG. 1 is turned on and the solenoid connecting arm 24 is moved to the left in FIG. 1 to slide the slide plate 46 in the same direction, the slide plate 46 is moved in the direction indicated by an arrow in FIG. In order to slide in the direction E shown in FIG. 4 (forward direction in FIG. 4), one end edge 45a of the lower end of the swing arm 45 is pushed out in the direction G shown in FIG. 3 (see also FIG. 4). The swing arm 45 has a shaft portion 44a,
With reference to 44b (FIG. 1) as a fulcrum, it swings clockwise in FIG.

As a result, the ribbon take-up pulley 27 is pushed rightward in FIG. 4 and pressed against the driving force transmitting chuck 43, so that the teeth 27a of the ribbon take-up pulley 27
And the teeth 43a of the driving force transmitting chuck 43 mesh with each other (the position where the driving force is transmitted), and the rotational force from the ribbon take-up pulley 27 is transmitted to the driving force transmitting chuck 43 side.
Therefore, the driving force transmission chuck 43 rotates in a direction in which the ribbon 4 wound around the ribbon winding core 12 is wound.

The ribbon 4 is fed out from the ribbon supply core 8 shown in FIG. 1, and a clutch 49 is attached to the ribbon supply core 8, and the clutch 49
, A back tension wire 51 is wound around as shown, and one end thereof is fixed. The other end of the back tension wire 51 is pulled by a back tension spring 52. Therefore, the back tension spring 52 is attached to the ribbon supply core 8.
1 always acts in the counterclockwise direction in FIG. 1, a predetermined tension acts on the ribbon 4 fed from the ribbon supply core 8, so that the ribbon 4 does not sag. It has become.

The belt platen 5 is stretched between the platen stretching rollers 53 and 54 so as to be rotatable in the direction of the arrow J, and between the platen stretching rollers 53 and 54,
A belt receiving plate 55 is provided so that even if the belt platen 5 is pressed by the thermal head 3 by the belt receiving plate 55, the belt receiving plate 55 does not bend more than a predetermined amount.
The surface of the belt platen 5 in sliding contact with the belt receiving plate 55 is subjected to a process for reducing a frictional force when the belt platen 5 is pressed against the belt receiving plate 55 by the thermal head 3.

Next, using the packaging printer shown in FIG. 1, the printing portions a1,
The following describes a case where the operation of continuously printing a2, a3... at a high speed at a constant interval S is performed while performing a ribbon save that leaves almost no unused portion on the ribbon 4 to be used. First, the conveying roller pair 2 shown in FIG. 1 is driven to convey the packaging film 1 to the left in the same figure, and the conveying speed of the packaging film 1 is detected by the speed detector 9, and the conveying speed of the packaging film 1 is detected. The ribbon winding motor 22 is driven at such a rotational speed that the transport speed of the ribbon 4 becomes the same as that of the ribbon.

Then, the solenoid 25 is turned on at a predetermined printing timing. Then, the solenoid connecting arm 24 moves to the left by the plunger 25a moving to the left in FIG. As a result, the crank arm 19 swings about the fulcrum shaft 18 in the counterclockwise direction in FIG.

Then, the drive arm 17 is moved to the intermediate arm 16.
1, the swing arm 15 rotates clockwise in FIG. 1 with the shaft 14 as a fulcrum, and the contact / separation roller 7 comes into pressure contact with the ribbon transport roller 6 via the ribbon 4. At this time, the contact / separation roller 7 is driven by the drive arm 17 and the intermediate arm 16.
The ribbon 4 is pressed against the ribbon transport roller 6 until the spring 32 attached between them is slightly extended.

When the solenoid 25 is turned on to move the solenoid connecting arm 24 to the left in FIG. 1, the slide plate 46 also slides in the same direction. As a result, the movement of the slide plate 46 has been described with reference to FIG. As described above, the portion of the one end edge 45a of the swing arm 45 is pushed out in the arrow G direction.

The swing arm 45 swings clockwise in FIG. 4 about the shaft portions 44a and 44b (not shown in FIG. 4; see FIG. 1), so that the ribbon take-up pulley 27 is driven. Pressed against the force transmitting chuck 43,
The teeth 27a on the ribbon winding pulley 27 mesh with the teeth 43a on the driving force transmission chuck 43, and the ribbon winding pulley 2
7 is transmitted to the driving force transmitting chuck 43 side.

Therefore, the driving force transmitting chuck 43 is
The ribbon 4 is rotated in a winding direction (clockwise direction in FIG. 1) for winding the ribbon 4 wound on the ribbon winding core 12 shown in FIG. Further, when the solenoid 25 is turned on, the crank arm 19 rotates counterclockwise about the fulcrum shaft 18 by the movement of the solenoid connecting arm 24 to the left in FIG. The right end side of the plate 35 in FIG. 1 is pressed down against the urging force of the pressing plate urging spring 36.

As a result, the head bracket 39 descends integrally with the thermal head 3 via the connecting member 41 and the spring absorbing mechanism 37, and the heat generating line portion 3 a of the thermal head 3 is belted via the ribbon 4 and the packaging film 1. It is pressed onto the platen 5 with a predetermined pressure suitable for printing.

Thus, printing can be performed while the packaging film 1 and the ribbon 4 are conveyed at the same conveyance speed in a state where they are overlapped with each other at the thermal head 3. here,
The thermal head 3 generates heat to perform desired printing.
The printing portion a1 shown in FIG. 5 is printed.

Then, as shown in FIG. 6 (the ribbon 4 is shown with the portion used for printing being outlined), the desired printing in the printing portion a1 is completed, and thereafter, some margin is given. The solenoid 25 shown in FIG. Then, the plunger unit 25
a moves to the right (in the direction C) in FIG. 1 by the urging force of a return spring (not shown).
4 also moves to the right. As a result, the crank arm 19 swings clockwise in FIG.

Then, the pressing of the intermediate arm 16 to the left by the drive arm 17 in FIG. 1 is released, so that the swinging arm 15 rotates counterclockwise in FIG. Since the release roller 7 moves to the position shown by the solid line in FIG. 3, the pressing of the ribbon 4 on the ribbon transport roller 6 by the contact / separation roller 7 is released.

The movement of the slide plate 46 in the above-described direction causes the one end 45a of the swing arm 45 described with reference to FIG.
Is returned in the direction opposite to the arrow G, so that the swing arm 45 swings counterclockwise about the shaft portions 44a and 44b (FIG. 1) in FIG. As a result, the ribbon take-up pulley 27 is separated from the driving force transmission chuck 43, and the engagement between the teeth 27a on the ribbon take-up pulley 27 side and the teeth 43a on the drive force transmission chuck 43 side is released. From the driving force transmitting chuck 43
Will not be transmitted.

Therefore, the rotation of the driving force transmitting chuck 43 is stopped, and the operation of winding the ribbon is temporarily stopped. Note that even at this time, the ribbon transport roller 6 and the ribbon take-up pulley 27 continue to be rotated at a rotational speed that enables the ribbon 4 to be transported at the same transport speed as the transport speed of the transport roller pair 2.

Further, the above-mentioned solenoid connecting arm 2
4, the crank arm 19 rotates clockwise in FIG. 1 around the fulcrum shaft 18, so that the right end of the head holding plate 35 in FIG. Is pushed up by the urging force. Thereby,
The head bracket 39 rises integrally with the thermal head 3 via the connecting member 41 and the spring absorbing mechanism 37, and the pressurization of the ribbon 4 on the packaging film 1 by the heating line portion 3a of the thermal head 3 is released.

As a result, as shown in FIG.
Is stopped, and only the packaging film 1 is transported in the transport direction (the direction indicated by the arrow K) during printing. Therefore, the ribbon 4 enters the temporary standby state with the last print use portion 4a of the portion used for printing the print portion a1 (the portion shown in white) is located near the heating line portion 3a of the thermal head 3. Become.

When only the packaging film 1 is conveyed by the distance S between the printing portion a1 and the next printing portion a2 described in FIG. 5 and the timing shown in FIG. 8 is reached, the solenoid 25 is turned on again. Become. Then, since the respective parts operate as described above, the contact / separation roller 7 again comes into pressure contact with the ribbon transport roller 6 via the ribbon 4.

The ribbon take-up pulley 2 described with reference to FIG.
7 is connected to the driving force transmission chuck 43 again, so that the driving force transmission chuck 43 rotates in a direction in which the ribbon 4 is wound. Further, when the right end side of the head holding plate 35 in FIG. 1 is pressed down against the urging force of the pressing plate urging spring 36, the thermal head 3 is lowered, and the ribbon 4 is placed on the packaging film 1 with a pressing force suitable for printing. Contact.

Thus, the packaging film 1 and the ribbon 4
The printing corresponding to the printing portion a2 (FIG. 5) is carried out by the thermal head 3 while being conveyed at the same conveying speed in a state where they are superimposed on each other at the portion of the thermal head 3. Then, as shown in FIG. 9, the printing in the printing portion a2 is completed, and thereafter, at a timing allowing for some margin, the solenoid 25 shown in FIG. In the printing of, the packaging film 1 is continuously transported by the solenoid 25 being repeatedly turned on and off at the timing described above.
The transport and the stop of the ribbon 4 are repeated as described above, and printing by the ribbon save of economical use that hardly leaves an unused portion on the ribbon 4 is continuously repeated.

In the case of a conventional thermal transfer printing apparatus, a large number of printed portions are continuously formed at predetermined intervals along the transport direction on a packaging film as a printing medium while performing ribbon save. Sometimes, each time printing of one unit is completed, the operation of returning the ribbon by a predetermined amount in the direction opposite to the above-described conveying direction has to be repeated, so that the conveying speed of the print medium is 500, such as a packaging printer used for various packaging. In the case of high-speed conveyance such as about 600 mm / sec, the rewinding process of the ribbon may not be able to follow the conveyance speed.

However, in the case of the packaging printer according to this embodiment, even if the interval S between the printing portions a1 and a2 described with reference to FIG. Since the ribbon 4 is not rewound in the direction opposite to the transport direction during printing, and is continuously driven at the same transport speed as the transport speed of the transport roller pair 2 without stopping the ribbon transport roller 6. Even when the printing is performed at a high speed such as the above-described conveying speed of about 500 to 600 mm / sec, the printing can be reliably performed.

Since the ribbon transport roller 6 continues to rotate without decreasing the rotation speed as described above, the ribbon transport roller 6 stands up from the stopped state to the same transport speed as the transport speed of the transport roller pair 2. Since it is not necessary to wait for the rising time as compared with the case of raising, even if the interval S between the above-mentioned print portion and the next print portion is small, it is possible to realize the print while enabling the ribbon save. . Moreover, since the ribbon is not returned by a predetermined amount in the direction opposite to the conveying direction at the time of printing of one unit every time printing of one unit is completed, the vibration of the ribbon which is likely to occur when the ribbon is rewound does not occur. The ribbon can be transported stably.

In this packaging printer, as described with reference to FIG. 1, the control device 30 detects the transport speed of the packaging film 1 based on a signal from the speed detector 9 and detects the transport amount of the packaging film 1 therefrom. doing. That is, in this embodiment, the control device 30 functions as a print medium conveyance amount detection unit. And the control device 30
Each time printing of one unit is completed, when the transport amount of the packaging film 1 calculated from the detected transport speed of the packaging film 1 reaches the interval S (predetermined value) described with reference to FIG. The drive of the solenoid 25 is controlled so that the contact / separation mechanism 10 is driven (ON operation) to press the ribbon 4 against the ribbon transport roller 6 being driven.

In this manner, the transport amount of the packaging film 1 is accurately detected, and when the detected transport amount reaches the transport amount corresponding to the interval S between the print portions, the ribbon contacting is performed. When the solenoid 25 of the release mechanism 10 is turned on, the ribbon 4 is pressed against the rotating ribbon transport roller 6, and the ribbon 4 is transported at the same transport speed as the packaging film 1 in the transport direction during printing. Therefore, even when the sheet is conveyed at a high speed, printing can be continuously performed with an accurate interval S between the printing portion and the next printing portion.

It is to be noted that, contrary to the above-described embodiment, the ribbon contact / separation mechanism may press the ribbon against the rotating ribbon transport roller when the solenoid is turned off. When the interval S shown in FIG. 5 is always constant, a cam is fixed to a shaft supporting the transport roller 50 shown in FIG. 1, and the cam is swung by a cam surface corresponding to the interval S of the cam. The moving lever may be swung, and the ribbon may be mechanically pressed against the ribbon transport roller by the displacement of the swiveling lever. Further, in the above-described embodiment, the case where the ribbon transport roller 6 functioning as the ribbon transport means is of a roller type has been described, but the present invention can be similarly applied to a ribbon transport means of a belt type.

[0069]

As described above, according to the thermal transfer printing apparatus of the present invention, high-speed printing can be performed by transporting the printing medium at high speed while saving the ribbon. Also, even if a ribbon save is performed, the ribbon is not returned to the direction opposite to the transport direction during printing, so that the ribbon hardly vibrates. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing the configuration of a packaging printer as a thermal transfer printing apparatus according to the present invention.

FIG. 2 is a plan view partially showing a connection portion between an intermediate arm and a drive arm of a ribbon contact / separation mechanism provided in the packaging printer.

FIG. 3 is a plan view partially showing a mechanism for swinging a swing arm provided in the packaging printer in a partially sectional view.

4 is a side view showing a part of a driving force contact / separation mechanism and a part of a driving force transmission mechanism provided in the packaging printer of FIG.

FIG. 5 is a schematic view showing an example in which a large number of printing portions are formed continuously at a predetermined interval S on a packaging film.

FIG. 6 is a schematic diagram showing a state in which an initial printing portion a1 is printed on a packaging film using the packaging printer of FIG. 1;

FIG. 7 is a schematic diagram showing a state in which the transport of the ribbon is stopped at the timing of FIG. 6 and the transport of only the packaging film is continued.

8 is a schematic diagram showing a state in which the transport of the ribbon is resumed after the state of FIG. 7 and the ribbon and the packaging film are transported at the same transport speed.

FIG. 9 is a schematic diagram showing a state in which the conveyance of the ribbon is stopped after the printing of the second print portion a2 and the conveyance of only the packaging film is continued.

[Explanation of symbols]

 1: Packaging film (print medium) 2: Transport roller pair (print medium transport means) 3: Thermal head (print section) 4: Ribbon 6: Ribbon transport roller (ribbon transport means) 9: Speed detector 10: Ribbon contact / separation Mechanism (ribbon moving unit) 12: Ribbon winding core (ribbon winding unit) 20: Printing unit moving mechanism (printing unit moving unit) 30: Control unit 40: Driving force transmitting mechanism 60: Driving force moving mechanism

Claims (3)

[Claims] 1. A printing section for printing on a print medium conveyed in a conveyance direction during printing by a print medium conveyance means for conveying a print medium, and a ribbon at a conveyance speed equal to the conveyance speed of the print medium conveyance means. A ribbon transport unit that is driven so as to be transportable, and a ribbon is brought into pressure contact with the ribbon transport unit that is being driven, and the ribbon is transported in the transport direction during printing of the print medium by the transport force of the ribbon transport unit, or A ribbon contacting / separating means for releasing pressure contact of the ribbon with respect to the ribbon transporting means, and moving the printing unit to a printing position when the ribbon is pressed against the ribbon transporting means by the ribbon contacting / separating means, And a printing section moving means for moving the printing section from a printing position to a retracted position when the pressure contact with the ribbon transport means is released. Character device. 2. A thermal transfer printing apparatus according to claim 1, wherein said print medium transport amount detecting means for detecting the transport amount of said print medium, and said ribbon when said transport amount detected by said means reaches a predetermined value. Means for operating the contact / separation means to press the ribbon against the ribbon transport means being driven and means for operating the printing section moving means to move the printing section to a printing position. apparatus. 3. The thermal transfer printing apparatus according to claim 1, wherein a driving force for driving the ribbon transport unit is transmitted to a ribbon winding unit that winds a ribbon used for printing, and the ribbon winding unit rotates the ribbon. A drive force transmitting mechanism for interrupting the transmission of the drive force is provided, and when the ribbon is pressed against the ribbon transport means by the ribbon contact / separation means, the drive force transmission mechanism is driven by the ribbon winding unit. And a driving force contact / separation mechanism for setting the driving force transmission mechanism to a position where the transmission of the driving force is cut off when the pressing of the ribbon against the ribbon transport means is released. Thermal transfer printing device.