JPS63193857A - Thermal head - Google Patents

Abstract

PURPOSE:To eliminate the need for increasing the width of a wiring pattern and simplify the manufacturing process of a thin-film element substrate, by constructing driving ICs so that a wiring pattern is used in common for two resistor units, each of which constitutes one bit at the time of heat generation, and electric power is supplied to the two resistor units at such timings as to avoid simultaneous heat generation. CONSTITUTION:Driving ICs 24, of a 64-dot driver type, comprises an array of even numbered elements and an array of odd numbered elements provided respectively on opposite sides, and are connected to a substrate 21 in the state of being mounted horizontally. A wiring 31 connected to resistors R1a, R1b is connected to a driver circuit terminal in the upper array of odd elements, whereas a wiring 33 connected to resistors R2a, R2b is connected to a driver circuit terminal in the lower array of even elements. Common wirings 32 are connected to a power-supplying wiring 19 in a pattern. On the electric current basis, a current corresponding to at most one half of the ICs is passed into the wiring 19, so that it is unnecessary to increase the width of the pattern of the wiring 19.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermal head in which a plurality of resistors and wiring patterns are arranged on an insulating substrate and a driving IC is mounted thereon.

[Conventional technology]

FIG. 9 is an external view of a conventional thermal head, and FIG. 10 is a plan view of the resistor portion shown in FIG.

A driving IC 124 is formed on the insulating substrate 121 on which the wiring patterns of the electrode wiring section 123, the recording side ground wiring 126, the signal terminal wiring section 127, and the resistor array 122 are formed through the 'a film formation process and the photoresist process. Equipped with
Wire bonding 125 connects the IC 124 to the wiring pattern portion and between the wiring patterns. In this thermal head, as shown in FIG.
One wiring electrode 119 is shared, and the wiring uses a material with low conductor resistance and a wide wiring pattern.

FIG. 11 is a circuit diagram of the thermal head of FIG. 9.

Resistor R, R2, R3, R4, R5, R6゜..., R
61, R62, R63, and R64 each constitute one heating dot, one end of which is connected to the wiring bridge 119, and driver circuits D, D2, . D3゜D・D・
Driven by D・°°゛・D61・D62・D63・D64. Image data input signal 114 is clock signal 1
The data is transferred to the shift register 11 in synchronization with the data output signal 17 and outputted to the next stage as a data output signal 118, subjected to serial/parallel data conversion, and latched into the latch circuit 112 by the latch circuit 115. Then, the enable signal 116 causes the driver circuits D1 to D64 to operate selectively via the gate circuits A to Δ64, and power is applied to predetermined heating dots.

[Problem that the invention seeks to solve]

In this conventional thermal head, the common wiring pattern 11
A large current flows through 9. For example, dot density 8 dots/M
, for B4 size printing paper, it is 10 to 2 OA, and in order to stabilize the color development characteristic, the conductor resistance needs to be about 20 mΩ.

For this reason, the width of the common wiring pattern 119 is set to about 5 to 10 mm, and in order to form a conductor, a material with a low resistivity such as Au, Cu, or Ag is formed thickly by plating, etc., or thick film printing is used to compensate. Such processing was necessary. For this reason,
The size of the insulating substrate 121 increases, and the process for forming conductors becomes complicated. Further, as can be seen from the external view shown in FIG.
9, a dedicated mask pattern with a size and shape corresponding to the desired printing width is required, so there is no flexibility in changing dimensions.

[Means for solving problems]

In the thermal head of the present invention, for each resistor unit that forms one dot when it generates heat, the wiring pattern is shared between every two resistors, and power is applied to the two resistor units at a timing when they do not generate heat at the same time. The driving IC is configured to perform the following steps.

[Effect]

Since the heat generation timings of the odd-numbered resistors and the even-numbered resistors do not overlap, at most half the current flows into the power application wiring compared to the conventional case, and the wiring pattern does not need to be wide.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram of an embodiment of the thermal head of the present invention.
2 is an external view of the thermal head shown in FIG. 1, FIG. 3 is a block diagram of the driving IC used in the embodiment shown in FIG. 1, and FIG. 4 is a plan view of the driving IC shown in FIG. 5 is a timing diagram explaining the operation of the circuits shown in FIGS. 1 and 3, FIG. 6 is a plan view showing the connection between the FJ element board and the driving IC of the embodiment shown in FIG. 1, and FIG. 2 is a plan view of the resistor portion of the embodiment shown in FIG. 1. FIG.

Resistors R1a and R1b' R2a and R26, R38 and R3.

R4a and R4b・R5a and R5b・R6a and R6b-”
'-1 (and R, R and R, R and 61a 61b 62a G2b 6
3aR, R and R each constitute one heat generating drawer 3b64aG4b. And the resistor R, Ra1bl and R, R share the wiring pattern 32 and 2a
2b Ru. Other resistances R, R,! =R', R... are also 3a
3b 4a 4b.

The image data input signal 14 is transferred to the shift register 1k2 in synchronization with the clock signal 17 and outputted to the next stage as the data output signal 18, and serial/parallel data conversion is performed.
latched to. and enable signals 161-162
As a result, driver circuits D1 to D64 operate via gate circuits A1 to A64, and power is applied to predetermined heating dots. Note that at this time, the enable signal 161 and the enable signal 162 are not turned on at the same time, as shown in the timing diagram of FIG. For this reason,
Resistor R1a, 16. Regarding R2a, R2,
The common wiring pattern 32 includes low antibodies R, R or R,
Either mark of R la 1b 2a
A current with an applied force of 2b flows.

In the thermal head of this embodiment, as shown in FIG. 2, the element substrate has a wiring pattern 23.26° 27 and a low antibody 22 formed on the insulating substrate 21 through a thin film deposition process and a photoresist process. Equipped with driving lG24,
Wire bonding 25 connects the IC 24 to the wiring patterns and between the wiring patterns. Although it is not shown in this figure, the IC is coated with a protective resin.
The thermal head was made by connecting the printed board for the external control 0 and attaching the heat sink cover, etc. In addition, this driving I
In the C24, as shown in the block diagram of FIG. 3, the data of the odd and even numbers of the shift register 11 is latched separately into latch circuits 121 and 122 and output to AND gate circuits 131 and 132, respectively. The circuits are also separated into odd and even numbers.

The driving IC 24 is of a 64-dot driver type, as shown in a plan view in FIG. The connections are as shown in FIG. Resistor R1,.

The wiring 31 connected to Rlb is connected to the driver circuit terminals of the upper odd-numbered columns, and the wiring 33 connected to the resistors R and R is connected to the driver circuit terminals of the lower even-numbered columns. The common wiring 32 is the power application wiring 19
connected to the pattern. In terms of current, at most (1/2)·10 minutes flows into the power application wiring 19, so there is no need to make it 1 wider.

Next, in this embodiment, resistors R, R and R.

Since the heat generation timings of 1a Ib 2a R2b do not overlap, the wiring 31.3 as shown in the pattern diagram of the resistor part (Figure 7)
2.33 are formed with the same pattern width. Therefore, in the case of 8 dots/InJR, the wiring pitch was 125 lines x 2/3 = 83 degrees, the pattern width was 60 Jun, and the gap was 23 m, which were dimensions that could be realized by the conventional technology as a thin film thermal head.

Furthermore, in this embodiment, the wiring pattern connection including the signal terminal wiring 27 and the power application wiring 26 is formed at the mounting pitch interval of one driver vJI C, and the adjacent wiring pattern units are connected by wire bonding. The connections connect the necessary signal terminals. Therefore, as a functional unit,
If the cutting positions 281 and 282 of the board are set as shown in FIG. 2, arbitrary dimensions can be obtained for each wiring pattern. Therefore, if the original board is 84 size, the defective thermal head can be changed to A4 size or B5 size after cutting.

Further, in this embodiment, the board size of the B4 size thermal head is 15 s x 260 m, which is 55% smaller in area than the board size of the conventional long-round head, which is 26 s x 270 m.

FIG. 8 is a plan view of a resistor section showing another embodiment of the present invention.

In this embodiment, the electrode pattern 3 common to resistors R and R2 is
2A and individual electrode pattern 31△.

32A, and the other configurations are the same as in the previous embodiment. This embodiment has the advantage that the shape of the resistor is simple.

(Effects of the Invention) As explained above, the present invention provides a common wiring pattern for every two resistor units for each resistor unit that forms one dot when it generates heat, and at the same time prevents two resistor units from generating heat at the same time. Applying power at the right timing has the following effects.

(1) The thin film element substrate can be created using a thin film deposition process and a photoresist process using conventional technology, and there is no need for special treatment to increase conductor resistance in order to stabilize color moisture characteristics. The manufacturing process can be simplified.

(2) By being able to cut the thin film element substrate into any size for each wiring pattern, it is possible to cut some defective products of large 9-maru heads into smaller thermal heads, and to create new products for small thermal heads. Manufacturing yields are improved and pattern creation costs are reduced, such as by eliminating the need for additional mask patterns.

(3) Furthermore, the element substrate of the thermal head of the present invention includes:
For B4 size, it can be realized with 55% of the area of the conventional technology, and the effect on miniaturization is clear.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of an embodiment of the thermal head of the present invention, Fig. 2 is an external view of the thermal head of Fig. 1, and Fig. 3 is a circuit diagram of an embodiment of the thermal head of the present invention.
A block diagram of the driving IC used in the embodiment shown in the figure, FIG. 4 is a plan view of the driving IC of FIG. 3, and FIG. 5 is a timing diagram explaining the operation of the circuit of FIGS. 1 and 3. 6 is a plan view showing the connection between the thin film element substrate and the driving IC of the embodiment shown in FIG. 1, FIG. 7 is a plan view of the resistor part of the embodiment shown in FIG. Fig. 9 is a plan view of the resistor part of another embodiment of the invention, Fig. 9 is a configuration diagram of the conventional thermal head, Fig. 10 is a plan view of the resistor part of Fig. 9, and Fig. 11 is a plan view of the resistor part of Fig. 9. FIG. 3 is a circuit diagram of the thermal head shown in the figure. Rla-Rlb-R2a・R2b°R3a・R3b・R
4a・R..., R and R64,...resistor, 4b・
64a 11...Shift register, 12.12+, 122...Latch circuit, 13.13
1,132. A, A2,... A64...AND gate circuit, D, D,..., D D...driver circuit, 1 2 63° 64
14... Data input signal, 15... Latch signal, 16+, 162... Enable signal, 17... Clock signal, 18... Data output signal, 19... Power application wiring, 21. ...Insulating substrate, 22...Resistor array, 23...Electrode wiring section, 24...Drive IC pellet, 25...Bonding wire, 26...Recording side ground wiring, 27... Signal terminal wiring section, 281.282...board cut...i side, 30.31, 32, 33.31A, 32A. 33A...Resistor electrode wiring, G...tC bullet ground section, 1+, I2...IC bullet signal input terminal, 0+,
02...IC pellet signal output yKi child. Patent applicant NEC Corporation\2, / Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. In a thermal head in which a plurality of resistors and wiring patterns are arranged on an insulating substrate and a driving IC is mounted, two resistor units are used for each resistor unit that forms one dot when heat is generated. 1. A thermal head characterized in that a driving IC is configured such that a common wiring pattern is used for each resistor, and power is applied to two resistor units at timings that do not generate heat at the same time. 2. The wiring pattern has one wiring pattern unit formed at the mounting pitch of the driving IC, and at the same time, it has become one operational functional unit by including wiring for signal terminals and wiring for power application. , the thermal head according to claim 1, wherein cascade connection is possible with adjacent wiring pattern units.