JPH03284964A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To simplify a structure, reduce cost and shorten an image printing time by using a cylindrical platen of a larger width than a line thermal head and forming a structure in which a part of each one of the both platen ends outside a line thermal head is opened and closed by clamping claws arranged on the both ends of the platen. CONSTITUTION:When a clamping claw 3 is set to 'clamp' state by the tensile strength of a clamp spring 6, a lever 9 moves a lever 8 to the left using a pin 17 as a fulcrum by the action of a cam follower 9A which follows a cam groove 10A, if a cam 10 is rotated in an arrow A direction. Then a lever 7 rotates counterclockwise using a pin 16 as a fulcrum by the action of the lever 8. Subsequently the clamping claw 3 rotates counterclockwise under the pressure of the lever 7, resisting the tensile strength of the clamp spring 6. This results in the release of clamping action by the clamping claw 3 which is pressed against a part of the periphery of the both clamp ends. A clamping claw operation drive mechanism is provided in pair at the both platen ends. The clamping claw 3 is controllably driven by rotary return drive control of the cam 10.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention wraps photographic paper fed around a platen and attaches a line thermal head to the platen via a thermal transfer ribbon that is transported at the same speed as the platen. Each ribbon color (yellow, magenta) is pressed.

This invention relates to a structural improvement of a thermal transfer printer that performs color printing by rotating according to the number of rotations (such as cyan).

[Prior Art] A nuclide printer has a mechanism for clamping one end of fed photographic paper at a predetermined position via a clamp claw formed on a platen during printing.

Examples of this mechanism include JP-A-63-309463, JP-A-60-94367, and JP-A-58-12805.
The one shown in Publication No. 4 is known as a typical example.

JP-A-63-309463 discloses an example in which one end of fed photographic paper is clamped with clamp claws provided at intervals on a longitudinal line on the outer periphery of the platen. ! For the outside, a notch is formed in the longitudinal direction on the outer circumference of the platen, and one end of the fed photographic paper is held with a clamp claw placed inside the notch so that it does not extend beyond the outside diameter of the platen. It is meant to be clamped.

When printing, a nuclide printer wraps fed photographic paper around a platen and prints at a predetermined rotation rate corresponding to the number of ribbons of each color on the platen, so it has the following drawbacks. Of the prior art listed in w, the former has clamp claws protruding from the outer periphery of the cylindrical platen, so the line thermal head that comes into pressure contact with the platen must be retracted from the platen every rotation during printing, and this up-down process is required. Since the operation takes extra time, there is a problem in printing efficiency. In the latter case, if the line thermal head is elastically held in a predetermined position with respect to the platen, there is no need for the up-down movement as described above, but it is necessary to form a notch in the platen. , the cost is high and the device becomes a compound cone. In addition, the line thermal head comes into contact with the rotating platen during the up and down movement of each rotation or at the notch, which causes problems such as wear on the line thermal head and shortening its life. there were.

[IL to be Solved by the Invention The present invention aims to eliminate the above-mentioned drawbacks, and aims to provide a simple structure, cost reduction, and
The purpose is to shorten printing time and improve reliability as a thermal transfer printer.

[Means for Solving Problem 11II] The thermal transfer printer of the present invention has a cylindrical platen whose length in the longitudinal direction is wider than a line thermal head, and clamp claws elastically supported in a swingable manner at both ends of the platen. The edge of the photographic paper fed to the platen can be opened and closed via the drive control of the clamp pawl opening/closing drive mechanism.

[Function] According to the above structure, both edges of the leading edge of the photographic paper fed are clamped by the drive control of the clamp claw opening/closing drive mechanism, and the line thermal head is pressed against the cylindrical platen via the thermal transfer ink ribbon. In this state, the cylindrical platen rotates multiple times corresponding to the number of ribbon colors, but since the clamp claw is located at the outer peripheral edge of the platen extending outward from the line thermal head, the line thermal head
- Printing can be performed while the platen remains in pressure contact without moving up and down with respect to the platen during each rotation.

[Embodiment] Hereinafter, one embodiment of the thermal transfer printer of the present invention will be explained based on FIG. 1.2. Figure 1 shows the main part of the present invention (platen part)
FIG. 2 is an enlarged side view showing the overall arrangement of the thermal transfer printer, and is particularly an enlarged side view for explaining the operation of the clamp claw opening/closing drive mechanism.
1 is a cylindrical platen, 2 is a line thermal head, 3 is a clamp claw elastically supported to be swingable symmetrically at both ends of the platen, and 5 is photographic paper fed to the platen. The length of the cylindrical platen 1 in the longitudinal direction is longer than the width of the line thermal head 2, and dips IA are formed on the circumference corresponding to the edge portions of both ends of the line thermal head 2 in the longitudinal direction. Photographic paper 5 marked a is line thermal head 2
Both side edges of the outwardly extending tip are clamped via the clamp claws under drive control of a clamp claw opening/closing drive mechanism explained in FIG. The platen groove IA is designed to prevent the edges of the line thermal head 2 from causing scratches or scratches on the photographic paper 5 when the line thermal head 2 is pressed against the platen 1. ,
The clamp claw opening/closing drive mechanism will be explained based on FIG. 2. The clamp claw 3 is attached to the end surface of the platen 1 by 1 [
It is arranged so that it can swing around the crossed pin 4 as a fulcrum,
In addition, when the clamp pawl opening/closing drive mechanism described later is not driven, the tensile force of the clamp spring 6 presses and clamps a portion of the outer periphery of both ends of the platen.

The levers 7, 8, and 9 are drive mechanisms for opening and closing the clamp claws 3, and the lever 8 is comprised of bins 11 and 12 installed in the support frame 5 and a rectangular sliding guide formed on the lever 8. The lever 8 is supported so that it can slide linearly by locking the levers with the levers 13 and 14, and a lever 7 that presses the clamp claw 3 is mounted on the support frame 15 at one end of the lever 8. The lever 9 is connected to the support frame 15 so as to be able to swing around a provided pin 16 as a fulcrum, and has a cam follower 9A at the other end that engages with a cam socket 10A formed on the cam 10. They are engaged so that they can swing about the implanted pin 17 as a fulcrum. The cam 10
By reciprocating the rotation (in the direction of the arrow), the cam follower 9A moves following the cam mechanism 10A, and the lever 9
．． 8.7, the clamp opening/closing drive control of the clamp claw 3 is performed. The state shown by the solid line of the lever is a state in which the cam has moved in the direction of the arrow, and the clamp claw 3 is in a clamped state by the tensile force of the clamp spring 6. When the cam 10 is rotated in the direction of arrow A from this state, the lever 9 moves the lever 8 to the left using the pin 17 as a fulcrum due to the movement of the cam follower 9A following the cam arm 10A, and the lever 8 moves to the left.
With this action, the lever 7 rotates counterclockwise about the pin 16 as a fulcrum. In this operation, the clamp claw 3 is rotated counterclockwise by being pressed by the lever 7 against the tensile force of the clamp spring 6, so that a part of the outer peripheral edge of both ends of the platen is rotated. The clamp of the clamp claw 3 that is in pressure contact is released. Needless to say, the clamp pawl opening/closing drive mechanism, whose state is shown by a dashed line, forms a pair at both ends of the platen. And clamp claw 3
The opening/closing drive control operation is performed by rotating and reciprocating drive control of the cam 10. 18 is an ink ribbon cassette containing a heat-sublimable color ribbon coated with three colors of yellow, magenta, and cyan, or four colors of yellow, magenta, cyan, and black; Ribbon feeding mechanism (
(not shown) to feed the ribbon. 2
1 is a line thermal head which swings around a pin 23 as a fulcrum, and is controlled so that it is in pressure contact with the plate and ten during printing, and is in pressure contact and released during non-printing. 20 is a photographic paper feed guide path, 21 is a printed photographic paper discharge guide path, 2
Reference numeral 2 denotes a photographic paper positioning sensor. In a thermal transfer printer having a configuration of 0 or more, during printing operation, the photographic paper is guided through a paper feed guide path 20 by an ASF or the like. At this time, the platen l is on standby with the clamp claw 3 in the predetermined clamp open state shown by the dashed line, and when the photographic paper is detected by the photographic paper positioning sensor 22, the clamp claw 3 The photographic paper is clamped by rotation control. In this state, as shown in FIG. 1, when the line thermal head 2 completes its external operation, the line thermal head 2 separates from the platen 1, and the ink ribbon also stops at a predetermined position. After printing is completed, the platen 1 stops and rotates reversely (clockwise) when the trailing edge of the photographic paper passes through the paper discharge entrance 21A of the paper discharge guide path 21. Due to the stiffness of the paper, the ends tend to move outward from the platen, so as a result, they are restricted from abutting against the upper wall forming the paper ejection guide path 21. Simultaneously with the rotation of the platen 1, the ink ribbon of the ink ribbon cassette 18 is fed in synchronization with the circumferential speed of the platen 1 in response to a predetermined timing signal, and the line thermal head 2 is pressed against the platen 1.

Then, while keeping the line thermal head 2 in pressure contact, move the platen 1 corresponding to the number of color ribbons to be used.
By rotating counterclockwise in FIG. 2, each color is transferred to the photographic paper and a print is formed. The print is moved. When the leading edge of the photographic paper is detected by the photographic paper positioning sensor 22, the clamp claw 3 that clamps the leading edge of the photographic paper is in the state shown in FIG. 2, the platen 1 is stopped, and the cam is 10, the clamp is released via the clamp claw opening/closing drive mechanism. The ejected photographic paper is completely ejected by a paper ejecting roller (not shown).

In this embodiment, the clamp pawl is driven to open and close via a lever mechanism using a motor as the drive source, but it may also be performed via a solenoid cap, and the modification of the clamp pawl opening/closing drive mechanism is not limited to the present invention. It does not change the gist of the article.

[Effects] As described above, according to the thermal transfer printer of the present invention, a cylindrical platen wider than a line thermal head is used, and a portion of both edges of the platen outside the line thermal head is clamped by clamp claws provided at both ends of the platen. By forming the platen so that it can be opened and closed, the shape of the platen is different from that of the conventional example.
Since printing can be performed without applying impact to the line thermal head each time it rotates, it is possible to extend the life of the line thermal head and improve reliability. In addition, by forming a ridge on the circumferential portion of the platen that faces the edge of the line thermal head to prevent the edge from coming into contact with the edge, it is possible to avoid the dents that occur when the edge comes into contact with the photographic paper during the printing operation. A cylindrical platen can be used without the need for a rough shape such as scratches or scratches, and since the entire width of the platen is used and no clamping mechanism is formed, the structure can be simplified and costs can be reduced, and furthermore, printing During operation, printing can be performed with the line thermal head in contact with the 7 platen, so it is possible to print while the line thermal head remains in contact with the platen.
The line thermal head comes into contact with the clamp claw every time it rotates wJH
This is a first example of a printing operation that performs an up-down operation for shortening the printing time as well as an improvement.
The figure is a schematic plan view of the main part of the present invention (platen part), and Figure 2 shows the overall arrangement as a thermal transfer printer, and Figure 1 is an enlarged side view for specifically explaining the operation of the clamp claw opening/closing drive mechanism. .

1...Platen 2...Line thermal head 3...Clamp claw 5... Photographic paper 7゜ 8, Re bar cam 18. Ink ribbon cassette Figure 1 Patent Application Man

Claims (2)

[Claims] (1) A thermal transfer printer that thermally transfers fed photographic paper onto photographic paper by pressing a line thermal head against a rotating platen through a thermal transfer ribbon that is transported at the same speed as the platen. The width of the cylindrical platen is made larger than the width of the line thermal head, and photographic paper clamp claws are provided at both ends of the platen and supported elastically so as to be swingable. is configured to clamp the edge of the photographic paper extending on the outer periphery of the platen outside the line thermal head contact area, and to open and close the clamp by controlling the drive of the clamp claw opening/closing drive mechanism. printer (2) The thermal transfer printer according to claim 1, characterized in that grooves are formed on the outer periphery of the platen on the edge portions of both ends of the line thermal head that come into contact with the rotating platen during the printing operation.