JPS63443Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a thermal printer that prints desired characters on thermal paper by selectively energizing a plurality of heating elements to generate heat.

Conventional thermal printers do not have a mechanism to detect whether or not thermal paper is set on the platen, so sometimes the heating element is energized and generates heat even when no thermal paper is set. be. As a result, the platen surface was softened and deformed.

Therefore, the present invention is intended to eliminate the above-mentioned drawbacks, and includes a contactor made of a conductive material provided near the heating element of the thermal head, a platen made of the conductive material, and a contactor made of a conductive material. The device is characterized in that it includes a detector that outputs a contact signal when the head and the platen come into contact without intervening thermal paper, and the contact signal causes the thermal head to be separated from the platen. This will be explained in detail using an example.

FIG. 1 is a schematic perspective view showing an embodiment of a thermal printer according to the present invention. In the figure, 1 is a drive source such as a pulse motor, 2 is a drive pulley rotated by this drive source 1, 3 is a driven pulley, and 4
5 is a print carrier fixed to one end of this drive wire 4; 6 is a guide shaft for spacing this print carrier 5; 7 is this guide shaft 6. magnet for rotating, 8
9 is a rotating arm for rotating the guide shaft 6; 9 is a platen made of conductive rubber; 1 is a rotating arm for rotating the guide shaft 6;
0 is a contact 10 as shown in detail in FIG.
a and a heating element 10b for printing dot-shaped letters, numbers, or symbols; 11 indicates when this contact 10a contacts the conductive platen 9 without intervening thermal paper 12; ,
a detector that detects this contact and outputs a contact signal;
14 is suspended from one end of the rotating arm 8 and rotates the guide shaft 6 to rotate the thermal head 1.
0 is a spring that presses the thermal paper 12 with a predetermined bias, and 13 is a drive circuit that receives a contact signal and outputs a magnet drive signal.

Next, the operation of the thermal printer according to the above configuration will be explained.

First, when there is thermal paper 12 on platen 9, contactor 10a contacts platen 9 via thermal paper 12, so no contact signal is output from detector 11. Therefore, desired dot-shaped characters can be printed by the heating element 10b.

Next, if there is no thermal paper 12 on the platen 9, the contact 10a will directly contact the platen 9.
A contact signal is output from the detector 11. The drive circuit is operated by the input of this contact signal, and a magnet drive signal is output. Therefore, the magnet 7 is energized by this magnet drive signal.
Therefore, the rotating arm 8 is attracted and the guide shaft 6 is rotated. As a result, the print head 10 is rotated away from the platen 9 via the print carrier 5. In this way, even if the heating element 10b is energized when there is no thermal paper 12 on the platen 9, the surface of the platen 9 will be softened by the heat.
Deformation can be prevented.

As described above in detail, the thermal printer according to the invention has the effect of effectively protecting the platen.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view showing an embodiment of the thermal printer according to this invention, Fig. 2 is a plan view showing the thermal head shown in Fig. 1, and Fig. 3 is a state of contact between the thermal head shown in Fig. 1 and the platen. FIG. DESCRIPTION OF SYMBOLS 1... Drive source, 2... Drive pulley, 3... Drive pulley, 4... Drive wire, 5... Print carrier, 6... Guide shaft, 7... Magnet,
8... Rotating arm, 9... Platen, 10... Thermal head, 10a... Contact, 10b... Heat generating element, 11... Detector, 12... Thermal paper, 13
...Drive circuit, 14...Spring.

Claims (1)

[Scope of utility model registration request] The presence or absence of paper is detected by the presence or absence of contact between electrodes placed on the platen side and the thermal head side with respect to the thermal paper, and the heating element of the thermal head pressed against the thermal paper is selectively energized to generate heat, causing the thermal paper to generate heat. A thermal printer that prints desired characters includes a contact made of a conductive material provided near a heating element of the thermal head, a platen made of a conductive organic material, and a contact made of a conductive organic material; The present invention is characterized by comprising a detector that detects this conductive contact and outputs a contact signal when the thermal head contacts without intervening thermal paper, and a separating means that separates the thermal head from the platen based on the contact signal. thermal printer.