JPH0596766A - Wiring pattern of thermal head - Google Patents

Abstract

PURPOSE:To achieve improvement of printing quality by a method wherein heating elements are composed of two parallel lines and a pitch of a heating segment of one heating element is shifted by a 1/2 pitch in the direction Y to a pitch of a heating segment of the other heating element. CONSTITUTION:Though a heating segment of respective heating elements 1A, B formed at an interval in parallel with each other is a segment between a grounded wiring pattern on ground side and a power source side wiring pattern existing on its both sides, the heating element 1A, B is formed by shifting the heating segment by 1/2 pitch of the heating segment to each other. That is, one line of the power source side wiring pattern 3A is arranged at the same position in the direction Y as corresponding one line of the ground side wiring pattern 4B, and the ground side wiring pattern 4A is connected to the adjacent ground side wiring pattern 4B at a position inside parallel lines of the heating elements 1A, B. The power source side wiring pattern 3A, B is connected to a common electrode 2A, B outside parallel lines of the heating element 1A, B. The ground side wiring pattern 4A is wire bonded to a corresponding terminal of a control circuit 1C via a corresponding land 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring pattern of a thermal head used in a thermal recording device.

[0002]

2. Description of the Related Art FIG. 2 is a connection diagram showing an example of a conventional wiring pattern. In the figure, 1 is a heating resistor, 2 is a common electrode, 3 is a power source side wiring pattern, 4 is a ground side wiring pattern, and 6 is a grounding side wiring pattern. A power source 8 is a control circuit IC. The selected wiring pattern 4 (one or more) of the ground side wiring patterns 4 is grounded by the control circuit IC (that is,
(Connected to the negative electrode terminal of the power supply 6) and a current flows from the power supply side wiring patterns on both sides of the grounded side wiring pattern 4 toward the grounding side wiring pattern, and the heating resistor 1 between Recording is performed on the thermosensitive recording paper that heats the section and comes into contact with the section.

FIG. 3 is a connection diagram showing another example of a conventional wiring pattern. In the figure, the same reference numerals as those in FIG. 2 designate the same or corresponding parts, 2A is a common electrode A, 2B is a common electrode B, 7
Is a changeover switch, and 10 is a reverse current blocking diode.
The changeover switch 7 connects the common electrode 2A or the common electrode 2B to the positive electrode terminal of the power source 6 in a time division manner. Common electrode 2
While A is connected to the positive electrode terminal, a current flows from the common electrode 2A adjacent to the grounded wiring pattern 4 that is grounded, and the section of the heating resistor 1 between them generates heat.
Further, while the common electrode 2B is connected to the positive electrode terminal, a current flows from the common electrode 2B adjacent to the grounded side wiring pattern 4 and the section of the heating resistor 1 between them is heated. Therefore, in the circuit shown in FIG.
As compared with the circuit shown in FIG. 4, the resolution of the recording points in the Y direction (the direction of the heating resistor is the Y direction and the direction perpendicular to this is the X direction) is doubled with the same density of the wiring pattern. Can be improved.

[0004]

The wiring pattern of the conventional thermal head as described above is not shown in FIG.
There is a problem that it is not suitable for high-resolution recording, and the conventional one shown in FIG.
Although the resolution of the recording point in the direction can be doubled, there are problems as described below.

That is, the backflow blocking diode 10 is required, the cost becomes high, and the board area for mounting the diode 10 is additionally required. Further, since the diode 10 and the IC 8 must be arranged on both sides of the straight line of the heating resistor 1, it is not possible to construct an edge type thermal head in which it is easy to observe the printing result immediately after printing. Further, since the paper feed is not stopped even during the switching of the common electrodes 2A and 2B (because the control is troublesome), the recording paper moves by ε while printing is performed by the common electrode 2A and then by the common electrode 2B. There is a problem that the printing point is shifted by ε. If the switching time is shortened in order to reduce ε, mutual interference occurs in printing of adjacent dots. In addition, the control circuit IC
The bit pattern arranged in the shift register in 8 is a 2-bit unit array for printing with the common electrode 2A and for printing with the common electrode 2B, and conversion from the 1-bit unit in the Y-direction position order to be printed is performed. It is troublesome, and it becomes difficult to control the history of the heat generation section. In addition, the one shown in FIG.
Both of the above-mentioned types have a problem that a large amount of heat energy must be applied so that the dots on both sides extend to the left and right in order to cause the dots to overlap with each other so that there is no printing gap.

The present invention has been made to solve such a problem in the conventional device.

[0007]

According to the present invention, a heating resistor is composed of two heating resistors, a heating resistor A and a heating resistor B, which are parallel to each other. The pitch of the heat-generating sections formed in the heat-generating resistor B is shifted by 1/2 pitch in the Y-direction with respect to the pitch of Y to overlap the adjacent heat-generating points in the Y-direction and to make the Y of the heat-generating points.
Improved directional resolution.

[0008]

1 is a connection diagram showing an embodiment of the present invention. In FIG. 1, the same reference numerals as those in FIGS. 2 and 3 denote the same or corresponding parts, and 1A is a heating resistor A and 1B is a heating resistor. B, 4
A is a ground side wiring pattern A, 4B is a ground side wiring pattern B, 5 is a connection land, and 9 is a bonding wire.

The heating resistors 1A and 1B are formed in parallel with each other with an interval D, and the heating section of each heating resistor is connected to a grounding side wiring pattern and a power source side wiring pattern on both sides thereof. However, in the heating resistors 1A and 1B, the heating sections are formed with a shift of 1/2 of the pitch of the heating sections. That is, one of the power source side wiring patterns 3A is arranged at the same position in the Y direction as the corresponding one of the ground side wiring patterns 4B, and the ground side wiring pattern 4A is located inside the parallel lines of the heating resistors 1A and 1B. It is connected to the ground side wiring pattern 4B adjacent in position. All the power supply side wiring patterns 3A are connected to the common electrode 2A outside the parallel lines of the heating resistors 1A and 1B, and all the power supply side wiring patterns 3B are outside the parallel line of the heating resistors 1A and 1B to the common electrode 2A. Is connected to the common electrode 2B on the opposite side. All the ground side wiring patterns 4A are wire-bonded to the corresponding terminals of the control circuit IC across the common electrodes 2A via the corresponding lands 5.

Same position in the X direction (for example, x ₀ )
Printing is performed in two steps. That is, the heating resistor 1
When A is in the position x ₀ , power is supplied from the changeover switch 7 to the common electrode 2A and the control circuit IC8 controls the grounding of the ground side wiring pattern 4A to perform the first printing. Assuming that the minimum unit for controlling the movement in the X direction is Δx, when the heating resistor 1A is at the position of x ₀ + nΔx (n is an integer), power is supplied to the common electrode 2A to print the data at the position of x ₀ + nΔx. After that, the changeover switch 7 is switched to supply power to the common electrode 2B, and the control circuit IC8 prints the data at the position x ₀ for the second time. If the moving distance in the X direction during the changeover of the changeover switch 7 is ε, D = nΔx
When set to + ε, the X-direction position of the dot printed by the heating resistor 1A and the dot printed by the heating resistor 1B exactly match each other.

The unit of the heat generation section by the connection of FIG. 1 is a section between the power supply side wiring patterns on both sides of the ground side wiring pattern, but this section has an overlap with an adjacent heat generation section by another heating resistor. Including the constituent parts, the resolution of dots in the Y direction by the connection of FIG. 1 is the same as that of the case of FIG. 3, and the overlap of the two heating resistors is obtained. It is not necessary to increase the thermal energy to overlap the adjacent dots as described above.

FIG. 4 is a pattern diagram showing an embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. 1 and 2 designate the same or corresponding parts, and FIG. 4 (a) is a conventional pattern and FIG. 4 (b). )
Is the shape of the print dot by the conventional pattern, Fig. 4 (c)
Shows the pattern of the invention. In the portion where the heating resistor 1 contacts the wiring patterns 3 and 4, the heating resistor is short-circuited by the wiring pattern, and the heat generation in that portion is reduced. Therefore, when printed with the pattern of FIG. 4A, the dot shape as shown in FIG. As shown in FIG. 4C, when the widths (dimensions in the Y direction) of the ground side wiring patterns 4A and 4B are reduced, the central portion of the printed dot shape shown in FIG. Increasing the widths of 3A and 3B reduces the lateral spread of the shape of the print dots. In the present invention, the spread on the left and right is the overlapped portion with the adjacent dot, so that the power supply side wiring pattern 3
The width of the overlap can be adjusted by the widths of A and 3B. Reducing the width of the overlap also results in reducing the effect of heat storage in the adjacent heat generating sections.

[0013]

As is clear from the above description,
According to the present invention, the following effects can be obtained. (A) It is possible to eliminate the deviation ε of the print dot in the X direction. (B) It is possible to improve the print quality by increasing the size of the unit heat generation section in the Y direction so that sufficient overlap can be achieved. (C) The backflow blocking diode can be omitted to reduce the cost, and the power loss due to the voltage drop due to the diode can be eliminated. (D) Since it is not necessary to increase the heat energy to take an overlap, it is possible to perform high-quality printing with low power consumption, and to speed up printing. (E) Since the heating resistors 1A and 1B are separated by D = nΔx + ε, control is facilitated and the effect of heat storage in adjacent dots can be reduced. (F) Since the arrangement of control bits in the control circuit IC8 for controlling the heat generation section of the heat generating resistors 1A and 1B is the same as the arrangement of the heat generation section, the data arrangement becomes easier and the history control becomes easier. .. (G) Since the heating resistor 1B can be formed on the edge of the substrate and the state of the recording paper on which the second printing has been completed can be observed immediately thereafter, an edge type thermal head can be constructed. .. (H) The shape of the printed dots can be improved.

[Brief description of drawings]

FIG. 1 is a connection diagram showing an embodiment of the present invention.

FIG. 2 is a connection diagram showing an example of a conventional wiring pattern.

FIG. 3 is a connection diagram showing another example of a conventional wiring pattern.

FIG. 4 is a pattern diagram showing an embodiment of the present invention.

[Description of Reference Signs] 1A heating resistor A 1B heating resistor B 2A common electrode A 2B common electrode B 3A power source side wiring pattern A 3B power source side wiring pattern B 4A ground side wiring pattern A 4B ground side wiring pattern B 5 land 6 Power supply 7 Changeover switch 8 Control circuit IC 9 Bonding wire

Claims (2)

[Claims] 1. A linear heating resistor is formed on a substrate,
A plurality of conductors contacting and crossing the heating resistor in a direction (X direction) perpendicular to a straight line (Y direction) of the heating resistor are formed at equal intervals in the Y direction. Every other conductor is a wiring pattern on the power supply side and a wiring pattern on the ground side, and the wiring patterns on the power supply side are connected in parallel and connected to the positive terminal of the power supply. Selected lead conductor (s)
In the wiring pattern of the thermal head configured to connect the above to the negative terminal of the power source via the control circuit IC, the heating resistors are the heating resistor A and the heating resistor B which are parallel to each other.
And a power-source-side wiring pattern that contacts the heat-generating resistor A, and a ground-side wiring pattern that contacts the heat-generating resistor A is a ground-side wiring pattern A and a heat-generating resistor. The power source side wiring pattern that contacts the body B is the power source side wiring pattern B, and the ground side wiring pattern that contacts the heating resistor B is the ground side wiring pattern B. One is arranged at the same position in the Y direction as one of the ground-side wiring patterns B in the portion that contacts the heating resistor B. One of the ground-side wiring patterns A is a parallel line of the above two heating resistors. Is connected to one of the ground side wiring patterns B adjacent to each other inside, and all the power source side wiring patterns A are connected to the common electrode A outside the parallel lines of the heating resistors, and all the power source side wiring patterns B are connected. Is heat resistance The ground-side wiring pattern A is connected to the common electrode B outside the parallel lines of the body, and the ground-side wiring pattern A is connected to the corresponding terminal of the control circuit IC provided outside the common electrode A.
A wiring pattern for a thermal head, comprising a changeover switch which is wire-bonded across the common electrode and connects the common electrode A and the common electrode B to a positive terminal of a power source in a time division manner. 2. A Y-direction dimension of a portion of each of the power supply side wiring patterns A in contact with the heating resistor A is a Y-direction dimension of a portion of each of the ground side wiring patterns A in contact with the heating resistor A. And the dimension in the Y direction of the portion where each pattern of the power source side wiring pattern B contacts the heating resistor B is made larger than that of each ground side wiring pattern B.
The wiring pattern of the thermal head according to claim 1, wherein a size in a Y direction of a portion in contact with is larger than that in the Y direction.