JPH0259373A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To improve the yield and increase the printing quality by providing a device which can fix the pivotal shaft of a pinch roller at an position in the groove, and fine-adjusting the parallelism of a platen roller to an optimal position with a capstan roller. CONSTITUTION:A long groove 33 is provided at the right and left with a reference position as a center in a frame on one side, and an adjustment lever 34 which rocks due to an eccentric cam 35 centering around a fulcrum 34a. This lever 34 can be fixed at any position by clamping a screw 34b. Here a force works on the pinch roller 4 due to a spring 8c, and if this pinch roller 4 comes in contact with a capstan roller 5, this force acts as a tension force. In addition, as a force rests on the pivotal shaft 8a in the B direction, the pivotal shaft 8a is fixed at a position where it is pressed against the adjustment lever 34. If an eccentric cam 35 is rotated, the pivotal shaft 8a moves along a groove 33 on an opposed frame, from a reference hole 37 in the pivotal shaft of the frame on the one side. Thus it is possible to adjust the center shaft of the pinch roller so that it becomes parallel with the center shaft of the capstan roller.

Description

[Detailed description of the invention] Industrial applications The present invention relates to thermal transfer printers.

BACKGROUND OF THE INVENTION FIG. 2 is an overall perspective view of a thermal transfer color printer. In the figure, 1 is a lower cabinet, 2 is a circuit section, and 3 is a power supply panel. A pinch roller 4 contacts the capstan roller 5 and applies a driving force. A platen roller 8 constitutes a paper feeding mechanism together with the pinch roller 4 and the capstan roller 5. Here, the capstan roller 5,
The platen roller 6 is driven by a main motor 7. Reference numeral 8 denotes a pinch roller lever that brings the pinch roller 4 into contact with the capstan roller 5 or releases the contact by interlocking with the operation of the cam, and which swings around the pinch roller fulcrum shaft 8a. 8C is capstan roller 6
The role is to press the pinch roller 4 into contact with the roller. 9 is a peeling roller that separates the ink film from the paper, 1o is a paper feed roller that brings the paper into contact with the platen roller e, and 11 is a paper guide that guides the paper.

Reference numeral 12 denotes a paper support that stores the paper wound into a roll. 13 is the cover frame and the lock lever
14 and lock lever shake) 15. ! It is opened and closed by engaging and disengaging l:. A ribbon feed gear 16 for positioning one end of the ribbon feed, in which an ink film is wound into a roll, is arranged on the cover frame 13, and a ribbon feed presser 17 for applying a pressing force to the other end of the ribbon feed. A head holder 18 has a fixed head 19, and is fixed to a head arm 2o that is linked to the operation of a cam. 21 is a cooling fan that radiates heat from the main motor 7, the circuit section 2, etc., and 22 is an operation panel. 23 is a top cover, and 24 is an upper cabinet.

By the way, in a conventional thermal transfer color printer, paper feeding and printing were performed as shown in FIG.

First, when feeding the paper, the paper 25 is fed by one screen in the input direction from the paper holder 26 by the rotational driving force of the pinch row 24 and the platen roller 6 in the counterclockwise direction, as shown by the hole in the figure.

At this time, the head 19 is located away from the platen roller 6, and the ink film 27 is in a stopped state, so no printing is performed. In the same figure &, reference numeral 28 denotes an ink film supply holder 29, which is an ink film winding holder.

Next, during printing, as shown in the figure, the platen roller 6 and the pinch roller 4 rotate clockwise, and the paper 26 is rewound in the direction B by one screen. At this time head 1
9 is in contact with the platen roller 6, the ink film holder 28 and the ink film take-up holder 29 are rotating counterclockwise, and the ink film 27 is in contact with the paper 2.
6 and is rewound in the B direction. In this way, heat is applied to the ink film 27 from the head 19, and the paper 2
6, a predetermined print is made. Incidentally, yellow, magenta and cyan are sequentially arranged on each screen on the ink film 27, and color printing is performed by repeating the above operation three times.

FIG. 4 shows details of a conventional pinch roller opening/closing mechanism which is a drive system for paper travel. To explain this, due to the rotation of the cam 31 and the action of the spring 8C, the pinch roller lever 8, which traces the cam 31 by the roller 8b, swings around the pinch roller fulcrum shaft 8a, and the pinch roller 4 and the capstan The rollers 5 are opened and closed. At this time, the capstan roller 5 is fixed to the left and right frames 36 of the printer via bearings, and the pinch roller fulcrum shaft 82L of the pinch roller 4 is fixed to the holes 37 of the left and right frames. is fixed through bearings to two left and right pinch roller levers 8 that rotate around a fulcrum shaft 1131L.

Problems to be Solved by the Invention However, in the configuration shown in FIG. 4, there are variations in the machining accuracy of the bearing hole positions of the capstan rollers 6 of the left and right mechanical frames 36 and the hole positions of the pinch roller fulcrum shaft 81L, and assembly accuracy. There may be variations in the parallelism between the capstan roller 6 and the pinch roller 4 due to variations in the machining accuracy of the fulcrum shaft hole of the pinch roller lever 8 and the position of the pinch roller bearing hole, and due to irregularities during assembly. If the parallelism between the capstan roller 6 and the pinch roller 4 is poor, in the case of thermal transfer color printers, the paper is moved back and forth for the number of colors and printed overlappingly, resulting in large print deviations between each color, which deteriorates print quality. Also, the printing misalignment was
In order to keep the color within 0.1, set the parallelism to 0.0.
It is necessary to maintain accuracy on the order of 1 ml, and attempting to guarantee processing accuracy alone would increase the cost of parts and was difficult to achieve.

The present invention provides a thermal transfer printer that can solve these problems.

Means for Solving the Problems The thermal transfer printer of the present invention includes a capstan roller, a pinch roller provided corresponding to the capstan roller and swinging open and closed around a fulcrum shaft, and a pinch roller and the capstan. An opening/closing means for opening and closing between the rollers, a pressure contact means for pressing the pinch roller against the capstan roller, a groove for holding the fulcrum shaft, a head for applying heat to the ink film, and a platen roller disposed near the head. A means for fixing the fulcrum shaft of the pinch roller at an arbitrary position in the groove is provided so that the parallelism between the capstan roller and the platen roller can be finely adjusted to an optimal position.

In this way, by finely adjusting the parallelism of the platen roller to the capstan roller to the optimum position, it is possible to suppress print misalignment in thermal transfer color printers, correct variations between mechanisms without increasing costs, and improve speed. This improves retention and print quality.

Embodiment FIG. 1 is a diagram showing details of a pinch roller opening/closing mechanism of a thermal transfer color printer according to an embodiment of the present invention. One side of the left and right frames has the structure shown in FIG. 4 as in the prior art, and the fulcrum shaft 82L of the pinch roller is positioned by a round hole. In addition, as shown in Fig. 1, the opposing frames have grooves 33 that are elongated holes on the left and right sides with the reference position as the center.
An adjustment lever 34 is provided which swings around a fulcrum 341L by an eccentric cam 35. This lever 34 has a screw 34b
It can be fixed in any position by fastening.

Here, a force is applied to the pinch roller 4 in the input direction by the spring 8c, and this acts as a stress force when the pinch roller 4 and the capstan roller 5 come into contact with each other. Also.

Since a force acts on the fulcrum shaft 8a in the direction B, the fulcrum shaft 8a is fixed at the position pressed against the adjustment lever 34. As a result, by rotating the eccentric cam 35, the fulcrum shaft Sa moves along the groove 33 on the opposite frame with reference to the reference hole 37 of the fulcrum shaft on one frame, and relative to the central axis of the capstan roller 6. Thus, the relationship between the central axes of the pinch rollers 4 can be adjusted so that they are parallel to each other.

In the above embodiments, one side of the fulcrum shaft is fixed and the other side is adjusted as variable, but the same function can be achieved even if both sides of the frame are provided with slotted slots so that both sides are variable. It goes without saying that the same function can be achieved by fixing the pinch roller to the frame and movably adjusting the capstan roller.

Effects of the Invention As described above, according to the present invention, the axis of the pinch roller can be adjusted to be parallel to the axis of the capstan roller after assembly and printing. A small, high quality thermal transfer color printer can be provided.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the pinch roller opening/closing mechanism of a thermal transfer color printer according to an embodiment of the present invention, FIG. 2 is an overall perspective view of the thermal transfer color printer, and FIGS. 3a and 3b are views of a conventional thermal transfer color printer. A schematic diagram of the operation of the paper feeding and printing portion, and FIG. 4 is a detailed diagram of the conventional pinch roller opening/closing mechanism. 4...Pinch roller, 5...Capstan roller, 8...Pinch roller lever, 82
L...Fully shaft, 8c...Spring, 31.
...Cam, 33...Groove, 34...
・WA node v bar +, 34a... fulcrum, 34b... river/fastening screw, 36... eccentric cam, 36...
··flame. Name of agent: Patent attorney Shigetaka Awano and one other person Figure 4 - Hint roller 5 - Gobustan roller 8 - Pinch roller lever - 8α - Support, color axis aC - - Hine 31 - Cam 33 - Groove - 34-Miyama fraud lever- 344-Exchange heat 34b-11 tan introduction screw 36-Frame city map map

Claims (1)

[Claims] A capstan roller, a pinch roller provided corresponding to the capstan roller and swinging to open and close around a fulcrum shaft, an opening/closing means for opening and closing between the pinch roller and the capstan roller, and a pinch roller that caps the pinch roller. It has a pressing means for pressing the stun roller, a groove for holding the fulcrum shaft, a head for applying heat to the ink film, and a platen roller disposed near the head, and the fulcrum shaft of the pinch roller is connected to the fulcrum shaft for holding the fulcrum shaft. A thermal transfer printer characterized by being provided with means that can be fixed at any position in the groove.