JPH0219238Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field of the Invention> The present invention relates to a thermal printer used in facsimile machines, etc., and particularly relates to an improvement in the mounting structure for preventing vibration of the thermal head.

<Technical Background> The thermal head of a thermal printer has a large number of heating elements on its surface, and this surface is placed facing the platen roller, and the heating elements selectively generate heat on the thermal paper on the platen roller. By doing so, desired printed dots are formed. The platen roller rotates intermittently to feed the paper, and this rotation causes the thermal head to vibrate.
In order to obtain uniform and clear printing, such vibrations of the thermal head must be prevented.

<Prior art and problems> The conventional thermal head mounting structure supports the vicinity of the rear surface of the thermal head facing the platen roller with a leaf spring, and fixes the leaf spring to the device housing.
The thermal head is supported by being pressed against the platen roller by the elastic force of a leaf spring. However, in such a structure, with the intermittent rotation of the platen roller, the free end of the thermal head, which is the rear end in the paper feeding direction, vibrates, and this vibration also causes the part in pressure contact with the platen roller to vibrate, resulting in uneven printing. Clear printing could not be obtained, and noise was generated due to vibration.

<Purpose of the invention> The present invention was devised in view of the above-mentioned shortcomings of the prior art, and it is a thermal head that can provide clearer and more uniform printing without preventing vibrations, and also prevents the generation of noise. The purpose is to provide a mounting structure.

<Structure of the invention> In order to achieve this object, according to the invention, the vicinity of the rear surface of the thermal head facing the platen roller is supported by a plate spring, and the platen spring is used to support the paper of the apparatus housing by the platen roller. Regarding the feeding direction, in the mounting structure of the thermal head fixed at the rear part,
At the end of the thermal head on the rear side in the paper feeding direction on the platen roller, there is provided an elastic plate that protrudes in the rear direction, and a receiving plate that is fixed to the device housing and abuts against the elastic plate in the direction of the platen roller. A mounting structure for a thermal head is provided.

<Embodiment of the invention> FIG. 1 is a perspective view of a thermal head mounting structure according to the invention, and FIG. 2 is a sectional view thereof. A thermal head 2 is provided facing the platen roller 1, and as the platen roller 1 rotates in the direction of arrow B, thermal paper 3 is transferred in the direction of arrow A. The thermal head 2 is a rectangular body whose longitudinal direction is in the axial direction of the platen roller 1, and is supported by leaf springs 4 at two points in the longitudinal direction. One end of the leaf spring 4 is fixed with a screw near the rear surface of the portion of the thermal head 2 facing the platen roller 1, and the other end is fixed with a screw to a housing frame 5 constituting the main body of the printer apparatus.
A rubber plate 6 protrudes and is fixed to the end of the thermal head 2 on the rear side with respect to the feeding direction of the thermal paper 3. A stopper receiving plate 7 that abuts the rubber plate 6 from below (from the platen roller side) is fixed to the housing frame 5. Since the movement of the rear free end of the thermal head 2 is absorbed by the rubber plate 6 coming into contact with the receiving plate 7, the vibration of the thermal head 2 is suppressed.

<Effects of the invention> As explained above, in the present invention, the vibration of the thermal head is absorbed by the elastic body that comes into contact with the stopper receiving plate member of the device housing frame, so uneven printing due to vibration is eliminated and printing is uniform. Clear printing can be obtained, and noise caused by vibrations can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a thermal head mounting structure according to the present invention, and FIG. 2 is a sectional view thereof. 1... Platen roller, 2... Thermal head, 3... Thermal paper, 4... Leaf spring, 5... Housing frame, 6... Rubber plate, 7... Reception plate.

Claims (1)

[Scope of utility model registration request] The vicinity of the rear surface of the thermal head facing the platen roller is supported by a plate spring, and the plate spring is connected to the device housing in the paper feeding direction by the platen roller.
In the mounting structure of the thermal head fixed to the rear part, an elastic plate is attached to the end of the thermal head on the rear side in the paper feeding direction on the platen roller and protrudes toward the rear, and the elastic plate is fixed to the apparatus casing side. A mounting structure for a thermal head characterized in that a receiving plate is provided which comes into contact with the platen roller from the direction of the platen roller.