JPS63179770A - Printer - Google Patents

Abstract

PURPOSE:To enable each split roller to be independently rotated and prevent a frictional force from being generated at the part of direct contact of a thermal head with a printing roller, by splitting the printing roller for pressing a thermal recording paper against the thermal head into a plurality of split rollers, and fixing each of the split rollers to a driving shaft. CONSTITUTION:Let the frictional force between each half-friction split roller and a shaft 4 be F3 and the frictional force between a thermal head 2 and each of the split rollers be F4, then a setting condition of F4>>F3 ensures that each of the split rollers 8, 9, 13, 14 makes direct contact with the thermal head, and is not rotated. Of the split rollers 8-14 into which a printing roller 3 is split, those making direct contact with the thermal head 2 are not rotated, so that no frictional force is generated at the parts of direct contact of the head 2 with the roller 3. Therefore, the head and the printing roller are prevented from being damaged, and a rotating torque of a controller is prevented from being varied according to the width of a thermal recording paper.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing device that prints on thermal paper using a thermal head.

[Conventional Technique #41 Conventionally, in this type of device, thermal paper is fed between a thermal head and one print roller, and while the print roller presses the thermal paper against the thermal head, the thermal paper is transferred to the thermal head. It was designed to print by sliding it.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional apparatus, when thermal paper having a width shorter than the length of the thermal head and print roller is fed, a portion where the thermal head and print roller come into direct contact is created. However, there was a problem in that a very large frictional force was generated in this part. This prevents damage to the thermal head and print roller, and the rotational torque of the print roller changes depending on the width of the thermal paper, making it difficult to slide the thermal paper at a uniform speed. was occurring.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a printing device that does not generate frictional force at the portion where the thermal head and print roller directly contact each other.

[Means for Solving the Problems] The printing device according to the present invention divides the print roller that presses the thermal paper against the thermal head into a plurality of divided rollers, and separates each roller from the drive shaft. It is characterized in that each divided roller can be rotated independently by being fixed or attached with a predetermined frictional force.

[Function 1] According to the printing device according to the present invention, among the divided rollers of the print roller, only the divided roller fixed to the drive shaft and the divided roller that presses the thermal paper are moved along with the drive shaft. The other dividing rollers directly contact the thermal head, and the frictional force of this contact portion exceeds the frictional force of the other dividing rollers against the drive shaft. The rollers do not rotate.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a side view schematically showing an embodiment of a printing device according to the present invention.

In this embodiment, a thermal head 2 is fixed inside a casing 1 of the main body of the apparatus, and a print roller 3 is pivotally supported by the thermal head 2 with a slight gap.A shaft 4 of this print roller 3 is attached to a pulley 5. A belt 7 is passed between the pulley 5 and the shaft of the drive motor 6, and the shaft 4 is rotated counterclockwise as the drive motor 6 rotates. Print roller 3 is the second
As shown in the figure, half free cushion divided rollers 8, half free cushion divided rollers 9, half free cushion divided rollers 10, fixed divided rollers 11, half It has a free cushion dividing roller 12, a half free cushion dividing roller 13, and a half free cushion dividing roller 14. Among these divided rollers, the fixed divided roller 11 is fixed to the center of the shaft 4,
It is formed by fixing an elastic body 15 made of, for example, urethane rubber around the periphery. On the other hand, each of the half flexible cushion divided rollers 8 to 10 and each of the half flexible cushion divided rollers 12 to 14 is arranged between the stopper 16 fitted on the shaft 4 and the fixed divided roller 11, and between the shaft 4
The rollers are respectively fitted between a stopper 17 fixed to the roller and the fixed divided roller 11.

These half-fri-cushion split rollers press fit each pipe 18 made of, for example, synthetic resin into the shaft 4 so as to have an appropriate frictional force, and also fit each bony body 15 made of, for example, urethane rubber into each pipe. It is formed by adhering to the periphery of 18. Then, the distance 11 between the outer ends of each divided roller 8 and 14 is B
The distance 12 between the outer edges of each dividing roller 19 and 13 is approximately 2rR#I longer than the width of A4 size paper, and the distance 12 between the outer edges of each dividing roller 10 and 12 is approximately 2 rttm longer than the width of the A4 sheet. The distance 12 is about 2 degrees longer than the width of 85 size, and the distance i4 between both ends of the dividing roller 11 is about 2 degrees longer than the width of A5 size. The purpose of making the width two times longer than the widths of the 84 size, A4 size, 85 size, and A5 size is to ensure that the paper is transported well even if the position of the paper is slightly shifted.

For example, if a large number of 85-size thermal papers 20 are stacked on the hopper table 19, the arm 22 pulled by the spring 21 rotates and pushes up the hopper table 19. One sheet of the thermal paper 20 stacked on the paper is brought into pressure contact with the paper feed roller 23 rotating clockwise and pulled out. The thermal paper 20 passes between the paper feed roller 23 and the main body 24, is guided to the gap between the thermal head 2 and the print roller 3, and is further passed through this gap to the feed roller 25 rotating clockwise. It reaches between the feed auxiliary roller 26 which is pressed against the roller 25. At this time, when the sensor 27 consisting of a light-emitting element and a light-receiving element detects that the thermal paper 20 has been guided, the paper feed roller 23 is activated by a clutch (
(not shown) is turned off and stopped. Further, the print roller 3 is moved in the six directions of the arrow and is pressed toward the thermal head 2 side. As a result, the fixed divided roller 11 of the print roller 3 and each half free cushion divided roller 10
, 12 press the 85-size thermal paper 20 against the thermal head 2, and the other half-flicushion dividing rollers 8, 9, 13, and 14 directly contact the thermal head 2.

Here, the frictional force between the thermal paper 20 and the fixed divided roller 11 is Fl, and I'1f between the thermal paper 20 and the thermal head 2
The lK force is F2, the friction force between each half-fricushion split roller and the shaft 4 is F3, and the thermal head 2
and the frictional force between each divided roller is F4, and the feed roller 25
Assuming that the frictional force between the auxiliary roller 26 and the auxiliary roller 26 is F5, the following conditions are set in advance.

Fl>>F2, F3>F2, F4)>F3, F
4≧F1>F3>F2, F3>F5 Therefore, under the condition of Fl>>F2, the fixed divided roller 11 conveys the thermal paper 20 while pressing it against the thermal head 2. Under the condition of F3>F2, each half free cushion dividing roller 10°12 conveys the thermal paper 20 while pressing it. Also, depending on the condition of F4>>F3, each half free cushion divided roller 8.9.13.1
4 directly contacts the thermal head 2 and does not rotate. Furthermore, due to the condition of F3>F5 and the conveyance speed of the feed roller 25 being set in advance to be slightly faster than the conveyance speed of the print roller 3, the thermal paper 20 follows the conveyance speed of the print roller 3 and is fed. There is a slight slip between the roller 25 and the auxiliary roller 26, and the sheet is conveyed without slack.

At this time, the thermal paper 20 is slid onto the thermal head 2 to print.

Next, the thermal paper 20 conveyed by the feed roller 25 is guided by the vapor guide 28 and reversed, and the paper 20 is rotated in the clockwise direction by the ejecting roller 29 and the ejecting auxiliary roller 30 which is in pressure contact with the roller 29. It passes through the gap and is ejected onto the stacker 31. Note that the frictional force and conveyance speed of the feed roller 29 and the auxiliary roller 30 are the same as those of the feed roller 25 and the auxiliary roller 26, and there is no possibility that the thermal paper 20 is fed out at a speed higher than the conveyance speed of the print roller 3. do not have.

When printing on A5 size thermal paper, the fixed divided roller 11 of the print roller 3 rotates to slide the thermal paper onto the thermal head 2, while the other half free cushion divided rollers 8 ,9゜10.12.13 and 14
directly contacts the thermal head 2 and does not rotate. Similarly, in the case of A4 size thermal paper, each half-free cushion dividing roller 8 and 14 directly contacts the thermal head 2 and does not rotate, and in the case of 84 size thermal paper, the thermal head 2 and print roller There is no part that 3 comes into direct contact with.

Note that 0 and 0 provided between each of the divided rollers 8 to 14
Each gap of 1 to 0.2 is filled by expanding each elastic body 15 in the longitudinal direction on the pressing surface when the print roller 3 is pressed.
Even in these gaps, the thermal paper can be sufficiently pressed against the thermal head 2 to perform printing.

As described above, according to this embodiment, among the divided rollers 8 to 14 obtained by dividing the print roller 3, the half free cushion divided roller that directly contacts the thermal head 2 does not rotate, so that the thermal head 2 and the print roller 3 No frictional force is generated between the parts that are in direct contact with each other.

By the way, in the above embodiment, the print roller 3 is divided according to each wheel of A5 size, 85 size, A4 size, and 84 size, but it is not limited to this, and it can be divided according to the width of the thermal paper used. In general, the more the paper is divided into pieces, the more it can be used with thermal paper of various widths.

[Effects of the Invention] As explained above, in the present invention, the print roller that presses the thermal paper against the thermal head is divided into a plurality of parts, so that frictional force is not applied to the part where the thermal head and the print roller directly contact each other. It is possible to capture a printing device that does not occur. This prevents damage to the thermal head and print roller, and also prevents the rotating torque of the controller from changing depending on the width of the thermal paper.

[Brief explanation of the drawing]

FIG. 1 is a side view schematically showing an embodiment of a printing device according to the present invention, and FIG. 2 is a plan view showing a print roller in the embodiment shown in FIG. DESCRIPTION OF SYMBOLS 1... Housing, 2... Thermal head, 3... Print roller, 4... Shaft, 5... Pulley, 6...
... Drive motor, 7... Belt, 8.9.10.12
,13゜14...Half free cushion divided roller,
11... Fixed divided roller, 15... Elastic body, 16.
17... Stopper, 18... Pipe, 19... Hopper table, 20... Thermal paper, 21... Spring, 22... Arm, 23... Paper feed roller, 24...
...Sabaki, 25...Feeding roller, 26...Feeding auxiliary roller, 27...Sensor, 28...Paper guide, 29...Ejecting roller, 30...Ejecting auxiliary roller, 31...・Stacker. Figure 2

Claims (1)

[Claims] In a printing device having a print roller that presses thermal paper against a thermal head, the print roller is divided into a plurality of divided rollers, and each divided roller is fixed to a drive shaft or A printing device characterized in that each divided roller can be rotated independently by being attached with frictional force.