JPH05104761A - Wiring pattern of thermal head - Google Patents

Abstract

PURPOSE:To adjust the length of the shape of a printing dot in an X-direction by constituting a heating resistor of mutually parallel heating resistors A, B and providing a changeover switch connecting common electrodes A, B to the positive side of a power supply in a time sharing system. CONSTITUTION:When a heating resistor 1A is present at the same position X0 in an X-direction, a current is supplied to a common electrode 2A from a changeover switch 7 and the earth of the wiring pattern 4 on an earth side is controlled by a control circuit IC8 to perform the first printing. Next, the min. unit controlling the movement in the X-direction is set to DELTAX and, when the resistor 1A is present at the position of X0+nDELTAX(n; integer), a current is supplied to the electrode 2A to perform the printing of the data of the position of X0+nDELTAX and, thereafter, the switch 7 is changed over to supply a current to an electrode 2B and the second printing of the position data of X0 is performed by the circuit IC8. When the moving distance in the X-direction during the changeover of the switch 7 is set to epsilon and the interval D between resistors 1A, 1B is set to D=nDELTAX+epsilon-delta, the length of the printing dot in the X-direction can be adjusted by adjusting delta.

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 is high, and an additional board area for mounting the diode 10 is 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 to the problem that the conventional device shown in FIG. 2 is not suitable for high-resolution recording,
Under the same conditions, the shape of the print dots is twice as long in the Y direction as compared to the conventional one shown in Fig.
In order to match the length in the direction with the length in the Y direction, there is a problem that printing must be continued for twice the time.

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

[0007]

In the present invention, the heating resistor is composed of two heating resistors A and B, which are parallel to each other, to realize high-speed printing.

[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, 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. And the power supply side wiring patterns 3A and 3B are formed by the heating resistors 1A and 1B so that they can be printed at the same position in the Y direction. 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,
All the power supply side wiring patterns 3B are heating resistors 1A, 1
It is connected to the common electrode 2B on the opposite side of the common electrode 2A outside the parallel line of B. All the ground side wiring patterns 4 are wire-bonded to the corresponding terminals of the control circuit IC8 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 grounding side wiring pattern 4 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 switching 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. Further, if D = nΔx + ε−δ is set, the dot printed by the heating resistor 1A and the dot printed by 1B are displaced by δ in the X direction.
By adjusting δ, the length of the print dots in the X direction can be adjusted.

Although the length of the print dots in the X direction is adjusted by using the wiring pattern shown in FIG. 1, the wiring pattern shown in FIG. 1 is adjacent by providing two heating resistors. It can be used for other purposes such as avoiding the influence of the heat generation zone and facilitating the heating history control.

[0012]

As is clear from the above description,
According to the present invention, the length of the print dot shape in the X direction can be adjusted.

[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.

[Explanation of symbols]

 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 4 Ground side wiring pattern 5 Land 6 Power source 7 Changeover switch 8 Control circuit IC 9 Bonding wire

Claims (1)

[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 which is in contact with the heating resistor A is a power source side wiring pattern A and a power source side wiring pattern which is in contact with the heating resistor B is a power source side wiring pattern B. The portion of the side wiring pattern A that contacts the heating resistor A is arranged at the same position in the Y direction as the portion of the corresponding power source side wiring pattern B that contacts the heating resistor B, and the ground side wiring pattern is the heating resistor A. And the heating resistor B are arranged at the same position in the Y direction so as to be in contact with each heating resistor, and all the power source side wiring patterns A are connected to the common electrode A outside the parallel lines of the heating resistor. All the power source side wiring patterns B are connected to the common electrode B outside the parallel lines of the heating resistors, and each ground side wiring pattern is connected to the corresponding terminal of the control circuit IC provided outside the common electrode A, Above Wiring pattern of a thermal head is characterized in that it comprises a changeover switch for connecting the electrode A and the common electrode B at the positive terminal of the power source division method.