JPH0226682Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a friction paper feeding mechanism that enables fine adjustment of the paper feeding amount. The present invention relates to a friction paper feeding mechanism that allows recording paper to be reciprocated for overlapping purposes, and which can easily adjust color misregistration.

Conventionally, the paper feed roller of this friction paper feed mechanism was
Various methods of pressing against the platen have been devised, but in most cases the pressing pressure is mechanically constant;
No mechanism was provided to easily change the pressing pressure. Therefore, by moving the recording paper back and forth and applying yellow, magenta, and cyan Mihara papers,
In a multicolor thermal recording device that produces many colors, the thermal head is in close contact with the platen during printing, but when the recording paper is returned to the starting position to print the next color, the thermal head Since the recording paper is not in close contact with the platen, the conditions for paper feeding are different between the feeding and returning of the recording paper, and the amount of feeding of the recording paper may be different. Therefore, when trying to create a mixed color by overlaying another color on top of the previously printed color, the other color may not overlap properly on top of the previously printed color, resulting in color misalignment. There were times when beautiful multicolor records could not be obtained.

In order to eliminate color misalignment, we measure the amount of misalignment and change the rotation amount of the platen by the amount of color misalignment.
Corrections were made for color misalignment, but each machine was
Because the amount of deviation was different, this method was not suitable for mass production.

Therefore, an object of the present invention is to mechanically easily eliminate color misregistration in a method of reciprocating recording in a multicolor thermosensitive recording device.

FIG. 1 is a diagram of a friction paper feeding mechanism of a general multicolor thermal recording device.

A rubber platen 4 rotatably supported by a bearing (not shown); blocks 6a, 6b rotatably attached to a rotating shaft 16 rotatably supported by a bearing (not shown); metal paper feed rollers 5a, 5b rotatably fixed to the block and compressed by the platen; brackets 8a, 8b directly connected to the block;
Fixed to solenoid fixing plates 13a and 13b fixed to a fixing plate (not shown),
Solenoid shafts 11a and 11b having spring hooks pass through the center and enable vertical movement of the solenoid shafts, and solenoids 12a and 12b are in close contact with the bracket and move up and down along the solenoid shafts. Possible caps 9a, 9b,
It is comprised of compression springs 10a and 10b which are fixed between the spring hook part of the solenoid shaft and the cap, and which produce a repulsive force when compressed.

The recording paper 7 passes between the platen 4 and the paper feed rollers 5a and 5b, and passes around the platen 4 in close contact with the platen.

FIG. 2 is a detailed view of the present invention, and is a detailed view of a mechanism for pressing the paper feed roller of the friction paper feed mechanism against the platen.

A platen 4 is rotatably supported by a bearing (not shown), a block 6a is rotatably attached to a rotating shaft (not shown) which is supported by a bearing (not shown), and a block 6a is fixed to the block. A solenoid shaft 1 with a male thread is fixed to a solenoid fixing plate 13a fixed to a fixing plate (not shown).
7 passes through the center and allows the solenoid to move up and down, and the solenoid shaft 17 is in close contact with the bracket 8a.
a cap 9a that is movable up and down along the solenoid shaft 17; a nut 14 with a spring hook that is attached to the male threaded portion 17a of the solenoid shaft 17 and can be moved up and down by turning the screw; and a nut 14 that is fixed to the solenoid shaft 17. It is comprised of a set screw 15 for holding the cap and a compression spring 10a which is fixed between the cap and the nut and generates a repulsive force when compressed.

The operation of the present invention described above will be explained using FIGS. 1 and 2.

When the solenoid 12a fixed to the solenoid fixing plate 13a is operated and the solenoid shaft 17 having a male thread passing through the center of the solenoid moves upward, a spring hook attached to the male thread of the solenoid shaft moves upward. As the nut 14a having the above-mentioned shape also moves upward, the compression spring 10a fixed between the nut and the cap 9a, which is movable up and down along the solenoid shaft, is compressed, and its repulsive force causes the cap 9a to move upward. Push upward. As a result, the bracket 8a that is in close contact with the cap also moves upward and is fixed integrally with the bracket. Block 6a rotatably fixes a metal paper feed roller
rotates around the rotating shaft 16, presses the paper feed roller against the rubber platen 4a, and brings the recording paper 7 into close contact around the platen.Then, the platen is rotated by the driving force of a pulse motor (not shown). Perform paper feed.

At this time, the nut 14 attached to the threaded portion of the solenoid shaft 17 was rotated to allow the nut 14 to move up and down, thereby making it possible to change the initial compression amount of the compression spring 10a. This makes it possible to change the compression force of the compression spring 10a even during the same stroke of the solenoid 12a, and it becomes possible to easily change the pressing pressure of the paper feed roller 5a against the platen 4.

When the paper feed roller 5a presses strongly against the platen 4, the amount that the paper feed roller 5a sinks into the platen 4 increases, and the contact length of the recording paper 7 being passed around the platen 4 with the platen 4 increases.
Since the amount of rotation of the platen 4 is constant, the amount of paper feed increases by the amount that the platen 4 is deeply inserted.

In addition, if the pressing pressure is weak, the amount of penetration is small, so the contact length of the recording paper 7 around the platen 4 is reduced.
Paper feed amount decreases.

As explained above, in the present invention, by providing the nut 14 that can rotate up and down on the threaded part 17a of the solenoid shaft 17 provided with a male threaded part, the amount of compression of the compression spring 10a can be easily changed, and the paper feed By making the pressing pressure of the roller 5a against the platen 4 variable, it is possible to easily finely adjust the amount of paper feed.

As a result of the above, the color shift that conventionally occurs in multicolor thermal recording devices that move recording paper back and forth can be reduced.
It became possible to resolve the problem easily.

[Brief explanation of drawings]

Fig. 1 is a side view of a friction paper feeding mechanism of a conventional general multi-color thermal recording device, and Fig. 2 is a front view of the main part of the mechanism for pressing the paper feeding roller of the friction paper feeding mechanism of the present invention against a platen. It is a diagram. 1... Thermal head, 2a, 2b... Guide roller, 3... Ink film, 4... Platen, 5a, 5b... Paper feed roller, 6a, 6b...
...Block, 7...Recording paper, 8a, 8b...Bracket, 9a, 9b...Cap, 10a, 10
b...Compression spring, 11a, 11b...Solenoid shaft, 12a, 12b...Solenoid, 13a, 1
3b... Solenoid fixing plate, 14... Nut, 1
5... Set screw, 16... Rotating shaft, 17... Solenoid shaft, 17a... Threaded portion.

Claims (1)

[Scope of utility model registration request] A rotatable rubber platen, a rotary shaft disposed near the platen, a block rotatable about the rotary shaft and adjacent to the platen, and a rotatable block rotatably disposed at one end of the block. a metal paper feed roller that presses against the platen; a compression spring provided at the other end of the block for biasing the paper feed roller so as to press against the platen; and a solenoid for pushing up from below, in which a threaded portion is formed on the outer periphery of the shaft of the solenoid, and a nut that engages with the threaded portion is provided, and the lower end of the compression spring is supported on the upper surface of the nut. A paper feeding mechanism for a multicolor thermal recording apparatus, characterized in that the pressing force of the paper feeding roller against the platen can be adjusted by rotating the nut.