JPH028784Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to a cover for protecting a thermal head of a thermal printer.

(b) Background of the technology By forming a plurality of electrical resistor elements on the surface of a substrate made of ceramics, etc., and causing the desired electrical elements to generate heat based on an electrical signal, various characters consisting of a combination of multiple dots can be created. , symbols, etc. can be printed on the recording medium.

Thermal printers based on this principle are
A recording medium is sandwiched between a thermal head on which resistor elements are formed and a platen, and an electric signal for printing is sent to the thermal head, and the recording medium is made to run at a predetermined speed. A normal thermal head forms a resistor element, and in order to prevent reverse current from flowing through the element,
Each element is equipped with a plurality of diodes connected oppositely.

(c) Prior Art and Problems Figure 1 is a side sectional view showing the printing section of the thermal printer having a conventional configuration, in which 1 is a thermal head mounting plate, 2 is a thermal head, 3 is a rotatable platen, and 4 is a thermal printer. is part of the heat-sensitive recording medium.
The thermal head 2 includes a plurality of conductor layers 7 to 9 on the upper surface of a ceramic substrate 6, a resistance layer 10 bridging the conductor layers 7 and 8, and insulating layers 11 and 12 laminated on the conductor layers 7 and 8, respectively. , a protective layer 13 laminated on the resistive layer 10 is formed, and a diode 1 is formed.
A cover 5 attached to the mounting plate 1 covers the diode 14 so as to protect it.

In the printing section configured in this way, the recording medium 4 is sandwiched between the protective layer 13 of the thermal head 2 and the platen 3, and a printing electric signal is sent to the thermal head 2 to selectively heat the resistive layer 10, and the platen 3 is rotated in the direction of arrow A, desired printing is applied to the recording medium 4 traveling as a result of the rotation.

However, in the conventional thermal printer having the cover as described above, when the leading end of a new recording medium is inserted between the thermal head and the platen, the leading end is inserted between the thermal head and the cover.
The drawback was that it was easy to get caught up in the process.

(d) Purpose of the invention The purpose of the invention is to provide a thermal printer that eliminates the above problems.

(e) Structure of the invention The above object is to attach a thermal head protective cover that exposes a resistor element formed on a thermal head and is wider than the thermal head so as to cover the upper part of the thermal head; Both sides of the recording medium in the width direction are provided with slopes for guiding each side of the recording medium in the width direction above the thermal head, and the lower end of the slope is located below the upper surface of the thermal head. This is achieved by a thermal printer characterized by:

(f) Examples of the invention Hereinafter, examples of the invention will be described using drawings.

FIG. 2 is a perspective view of a thermal head protection cover of a thermal printer according to an embodiment of the present invention attached to a thermal head mounting plate, and FIG. 3 is a side view taken in the direction of arrow B in FIG.

In FIGS. 2 and 3, 31 is a thermal head mounting plate, 32 is a thermal head fixed to the mounting plate, and 33 is a cover screwed to the mounting plate. Cover 33 formed into an almost M-shape when viewed from the side
It is composed of two pairs of mounting legs 34, a pair of slopes 35, and a bottom surface 36 that connects the slopes, and a square window 37 extending over the middle part of the bottom surface 36 and a part of the slope 35 is bored. Then, the leg 34 is inserted through the machine screw 38.
When attached to the side end surface of the mounting plate 31, the resistor element array area 39 of the thermal head 32 (the area where a plurality of elements 10 in FIG.
The bar-like remaining portion of the bottom surface 36 protrudes to the side of the thermal head 32 and is half depressed below the top surface of the thermal head 32. On the other hand, a rotatable platen (rubber roller) 40 is used to bring a recording medium (not shown) into contact with the element array area 39 of the thermal head 32.
is longer than the element array area 39 and fits within the window 37, and the width of the window 37 in the longitudinal direction is shorter than the width of the medium.

Therefore, the cover 33 is used to protect the diode mounted on the thermal head 32 (corresponding to the diode 14 in FIG. 1) and the connecting portion connecting the thermal head 32 to its drive circuit (exposed conductor layers 7 and 9 in FIG. 1). In addition, when inserting a new recording medium, the remaining bottom surface 36 and the side portions of the slope 35 connected thereto guide the leading end of the medium so that it is led out above the cover 33. Become.

4 and 5 are perspective views of a cover different from the above embodiment.

In FIG. 4, a cover 41, which is attached in the same manner as the cover 33 described above, has almost the same shape as the cover 33, but has a slot at the longitudinal end of the window 42 for exposing the resistor element array of the thermal head. 43 so that the inclination angle of the opposing slope 44 can be independently set. Therefore, the cover 41 is
This has the advantage that it is easy to narrow the distance between each of the slopes 44 and the upper surface of the thermal head located below them.

In FIG. 5, a cover 51, which is attached in the same way as the conventional cover 5, protects only the diode mounting side of the thermal head, and is configured to prevent the insertion end of the recording medium from getting caught, and has a simplified shape. The recording medium is guided near each end in the width direction and in contact with the upper inclined end surface 53 of the cover mounting leg 52.

(g) Effects of the invention As explained above, according to the invention, when inserting a recording medium, the leading edge of the recording medium does not go under the thermal head protective cover, which simplifies the handling of the thermal printer and prevents mistakes. This has the effect of eliminating lost time due to insertion.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing the printing section of a conventional thermal printer; Fig. 2 is a perspective view of a thermal printer according to an embodiment of the present invention in which a thermal head protection cover is attached to a thermal head mounting plate; 3 is a side view as viewed from arrow B in FIG. 2, FIG. 4 is a perspective view showing a thermal head protection cover according to another embodiment of the present invention, and FIG. 5 is a side view showing a thermal head protection cover according to another embodiment of the present invention. FIG. 3 is a perspective view showing a related thermal head protection cover. In the figure, 2 and 32 are thermal heads;
3 and 40 are rubber rollers (platen), 4 is a recording medium, 5, 33, 41, and 51 are thermal head protection covers, 34 and 44 are slopes, and 53 is a slope end surface.

Claims (1)

[Claims for Utility Model Registration] By running a recording medium sandwiched between a thermal head and a platen and selectively generating heat from a plurality of resistor elements formed in the thermal head, a combination of a plurality of dots can be produced. In a thermal printer that prints characters, etc. on the recording medium, a thermal head protective cover that exposes each resistor element and is wider than the thermal head is attached to cover the upper part of the thermal head, and the cover is Both sides of the recording medium in the width direction are provided with slopes that guide the sides of the recording medium in the width direction above the thermal head, and the lower ends of the slopes are located below the upper surface of the thermal head. A thermal printer featuring