JPH0363140A - Thermal head - Google Patents

Abstract

PURPOSE:To enable the printing of a longitudinal or lateral bar code by lengthening the direction of the sub-scanning direction extending over a heating resistor and a sub-heating resistor or shortening the length of the sub-scanning direction of the heating resistor and generating heat only in the heating resistor. CONSTITUTION:A heating resistor 4 and a sub-heating resistor 5 are made independent in the main scanning direction respectively while one parts of a heating resistor layer 3 and an electrode section 6 are removed through first photoetching and a clearance is formed in order to make a discrete electrode 8 and a sub-discrete electrode 9 independent. Consequently, voltage is applied to a common electrode 7 and the discrete electrode 8, thus generating heat in the heating resistor 4 connected to both electrodes 7, 8. Voltage is applied to the common electrode 7 and the sub-discrete electrode 9, thus generating heat in the heating resistor 4 and the sub-heating resistor 5. Accordingly, length in the sub-scanning direction extending over the heating resistor and the sub- heating resistor is lengthened or shortened, and only the heating resistor is made to generate heat and the printing of a longitudinal or lateral bar code and the printing of other data such as characters are enabled.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a thermal head.

Prior Art First, a conventional example is shown in FIGS. 4 and 5. 5 is a longitudinal side view, and FIG. 6 is a partial plan view. In the figure, 21 is a substrate, and a glaze layer (insulating layer) 22 formed on the surface of this substrate 21 has a glaze layer (insulating layer) 22 in the main scanning direction ( A large number of heating resistors 23 are arranged at predetermined intervals in a direction perpendicular to the feeding direction of recording paper during printing), and a common electrode 24 is connected to both ends of these heating resistors 23 in the sub-scanning direction. and a large number of individual electrodes 25 are formed, and further a protective layer 26 covering these heating resistors 23, common electrode 24, and individual electrodes 25 is formed.
is formed.

Therefore, by applying a voltage to the common electrode 24 and the selected individual electrode 25, the desired heating resistor 23 generates heat, and this heat discolors the thermosensitive coloring paper or records the ink on the thermal transfer ink ribbon. A desired image can be recorded by transferring it to paper. 7 and 8 show the heating resistor 23 having a longer length in the sub-scanning direction (parallel to the recording paper feeding direction), and other configurations are shown in FIGS. 4 and 5. It is similar to

2. Description of the Related Art Recently, barcodes are often used to process objects in distribution processes, factory automation, etc., and the demand for thermal printers suitable for printing barcodes is increasing. There are two types of barcode printing: vertical barcode printing, in which the bars are lengthened parallel to the sub-scanning direction (recording paper feeding direction), and horizontal barcode printing, in which the bars are lengthened parallel to the main scanning direction.

Problems to be Solved by the Invention In the thermal head shown in FIGS. 4 and 5, the shape of the exposed surface of the heating resistor 23 is approximately square, and the length in the main scanning direction and the sub-scanning direction is the minimum unit length. Therefore, a vertical bar code can be printed by selecting the desired heating resistor 23, applying voltage for a certain period of time, and feeding the recording paper. A horizontal bar code can be printed by correspondingly applying a voltage intermittently to feed the recording paper. In this case, the print quality is good, but
Since the length of the heating resistor 23 in the sub-scanning direction is short, it takes a long printing time to pull the bar in the sub-scanning direction. On the other hand, in the case shown in FIGS. 6 and 7, the heating resistor 2
3 has a long length in the sub-scanning direction, so vertical barcodes can be printed at high speed, but when printing horizontal barcodes, the bars become thicker, which causes problems with barcode standards. However, it is inappropriate because the resolution decreases.

Means for Solving the Problem A large number of heat generating resistors are arranged on an insulating layer formed on the surface of a substrate with predetermined gaps in the main scanning direction, and one end of these heat generating resistors is connected in the sub scanning direction. forming a common electrode and a large number of individual electrodes connected to the other end of each of the heating resistors in the sub-scanning direction, one end of which is connected to the heating resistor in the sub-scanning direction, and the other end of each of the sub-individual electrodes connected to the other end of the heating resistor in the sub-scanning direction. A large number of sub-heating resistors connected to electrodes were arranged on the insulating layer with predetermined gaps in the direction in which the heating resistors were arranged.

By applying a voltage to the working common electrode and the individual electrodes, the heating resistor connected to the picture electrode can be made to generate heat.
In addition, since the heating resistor and the sub-heating resistor are connected along the sub-scanning direction, applying a voltage to the common electrode and the sub-individual electrode causes the heating resistor and the sub-heating resistor to generate heat. Therefore, it is possible to print vertical barcodes at high speed by increasing the length of the heating resistor and the sub-scanning direction in the sub-scanning direction, and also to increase the length of the heating resistor in the sub-scanning direction. It is also possible to print horizontal barcodes by shortening the length and making only the heating resistor generate heat.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 and 2. 1 is a substrate made of a material such as ceramic or alumina, and a glaze layer 2, which is an insulating layer, is formed on the surface of this substrate 1. On this glaze layer (insulating layer) 2, there is a A large number of heating resistors 4 and sub-heating resistors 5 are formed in parallel with a predetermined gap in a direction perpendicular to the feeding direction of recording paper during printing. One end of each heating resistor 4 in the sub-scanning direction is connected to the common electrode 7, and the other end of the heating resistor 4 and one end of the sub-heating resistor 5 are directly connected and individually connected to the individual electrodes 8. , the other end of the sub-heating resistor 5 is connected to the sub-individual electrode 9. Further, the heating resistor 4, the sub-heating resistor 5, the common electrode 7, the individual electrodes 8, and the sub-individual electrodes 9 are covered with a protective film IO.

Here, a method for forming the heating resistor 4, the sub-heating resistor 5, the common electrode 7, the individual electrodes 8, the sub-individual electrodes 9, and the protective film 10 will be described. First, Ba
By RF sputtering using RuOs as a target, 100O
A heating resistor layer 3 is formed to have a film thickness of A, and then a 1 μm thick At film is formed as an electrode layer 6. Thereafter, in order to make the heat generating resistor 4 and the sub-heating resistor 5 independent in the main scanning direction, and to make the individual electrode 8 and the sub-individual electrode 9 independent, a part of the heat generating resistor layer 3 and the electrode layer 6 are removed. is removed by the first photoetching to form a gap. Next, in order to form the heating resistor 4 and the sub-heating resistor 5,
The upper electrode layer 6 is removed by a second photo-etching process. The heating resistor 4 has a substantially square shape, and the length of the sub-heating resistor 5 in the sub-scanning direction is set to be equal to or longer than the length of the heating resistor 4 in the sub-scanning direction. Finally, a protective film IO is formed by RF sputtering A Q , O, to a thickness of 5 μm.

In such a configuration, by applying a voltage to the common electrode 7 and the individual electrodes 8, the heating resistor 4 connected to the picture electrode 7.degree. 8 can be caused to generate heat. Furthermore, in the embodiment, the heating resistor 4 and the sub-individual electrode 5 are directly connected and also connected to the individual electrode 8, so that a voltage is applied to the common electrode 7 and the sub-individual electrode 9. This allows the heating resistor 4 and the sub-heating resistor 5 to generate heat. Therefore, it is possible to print a vertical bar code at high speed by increasing the length in the sub-scanning direction between the heating resistor 4 and the sub-heating resistor 5. In particular, the length of the sub-heating resistor 5 in the sub-scanning direction By making the length longer than that of the heating resistor 4, vertical barcodes can be printed even faster.

Therefore, by shortening the length of the heating resistor 4 in the sub-scanning direction, it is possible to print a horizontal bar code or other data such as characters by making only the heating resistor 4 generate heat.

Further, when printing a vertical bar code by generating heat in the heating resistor 4 and the sub-heating resistor 5, the length of the sub-heating resistor 5 in the main scanning direction is the same as that of the heating resistor 4 in the main scanning direction. Since the length in the sub-scanning direction is longer than that of the heating resistor 4, the electric resistance value and the heating temperature of the sub-heating resistor 5 can be made higher than those of the heating resistor 4. As a result, there is no visible difference in the width of the dots formed by the heating resistor 4 and the sub-heating resistor 5. In this case, as shown in FIG. 3, by aligning the centers of the heating resistor 4 and the sub-heating resistor 5 on a straight line along the sub-scanning direction, the width of the dot formed by the sub-heating resistor 5 can be adjusted. The intervals between the dots can be made equal, and the difference in dot width caused by the heating resistor 4 can be visualized in a state where it can be further ignored.

Effects of the Invention Since the present invention is configured as described above, by applying a voltage to the common electrode and the individual electrodes, the heating resistor connected to the picture electrode can be made to generate heat, and the heating resistor and Since the sub-heating resistor and the sub-heating resistor are connected along the sub-scanning direction, by applying a voltage to the common electrode and the sub-individual electrode, the heat-generating resistor and the sub-heating resistor can be made to generate heat. , the length in the sub-scanning direction spanning the heating resistor and the sub-heating resistor is increased so that vertical barcodes can be printed at high speed, and the length of the heating resistor in the sub-scanning direction is shortened; It has effects such as being able to print horizontal bar codes and data such as characters by only generating heat from the heating resistor.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional side view showing an embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a plan view showing a modified example, Fig. 4 is a longitudinal sectional side view showing a conventional example, and Fig. 5. 6 is a longitudinal sectional side view showing another conventional example, and FIG. 7 is a plan view thereof. l...Substrate, 2...Insulating layer, 4...Heating resistor,
5...Sub heating resistor, 7...Common electrode, 8...Individual electrode, 9...Sub individual electrode diagram

Claims (1)

[Claims] 1. A large number of heat generating resistors arranged on an insulating layer formed on the surface of a substrate with predetermined gaps in the main scanning direction, and one end of these heat generating resistors in the sub scanning direction. A connected common electrode and a large number of individual electrodes connected to the other end of each of the heating resistors in the sub-scanning direction are formed, one end of which is connected to the heating resistor in the sub-scanning direction, and the other end of each electrode is connected to the heating resistor. A thermal head characterized in that a large number of sub-heating resistors connected to sub-individual electrodes are arranged on the insulating layer with predetermined gaps in between along the arrangement direction of the heat-generating resistors. 2. The thermal head according to claim 1, wherein the electrical resistance value of the sub-heating resistor is set larger than the electrical resistance value of the heating resistor. 3. The thermal head according to claim 1 or 2, wherein the length of the sub-heating resistor in the sub-scanning direction is set to be equal to or greater than the length of the heat-generating resistor in the sub-scanning direction.