Linear thermal print head and linear thermal print head apparatu

Details Linear thermal print head and linear thermal print head apparatu Linear thermal print head and linear thermal print head apparatu

1997-07-07

1999-05-25

Tran, Huan

Incremental printing of symbolic information

Thermal marking apparatus or processes

Specific resistance recording element type

B41J 2335, B41J 2345

Patent

active

059073470

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

1. Technical Field
The present invention relates to a line type thermal print for printing in a facsimile or the like, the line type thermal print head comprising a heating resistor and circuit patterns corresponding to respective portions of the heating resistor.
Also, the present invention relates to line type thermal print head device, including the above mentioned line type thermal print head and a head connector which is mounted on the print head in such a manner as to conduct to each of the connection terminals of the line type thermal print head.
2. Background Art
(1) Line Type Thermal Print Head
Generally, a thermal print head of this type has a rectangular head circuit board and a heating resistor formed in a straight line in the longitudinal direction (line-direction) of the circuit board. A common wiring pattern is formed so as to extend in parallel with the heating resistor along one side edge in the longitudinal direction of the surface of the head circuit board, and the common wiring conducts to those portions of the heating resistors which correspond to the respective print dots. Further, a plurality of individual circuits are formed in the area opposite to the common wiring across the heating resistor on the surface of the head circuit board. The individual circuits conduct to those portions of the heating resistor which correspond to the respective dots. Further, a ground wiring pattern is formed so as to extend in the longitudinal direction of the surface of the head circuit board, and a plurality of driver elements are mounted on the head circuit board which connect the ground wiring to the individual circuits.
When each driver element switches from one circuit to another under the condition that the line type thermal print head is mounted in the printer of a facsimile or the like, an arbitrary individual circuit electrically conducts to the ground wiring. Accordingly, the portion of the heating resistor which corresponds to the currently conducting individual circuit generates heat, so that printing takes place at the print dot according to the amount of heat generated.
The ground wiring and the common wiring in the line type thermal print head extend along the linear heating resistor. Both wiring patterns are connected to a power source so as to have electrical power supplied at one end or both ends thereof. Since both wiring patterns are thin and long and narrow, it is difficult to reduce the electrical resistance of both wiring patterns. Therefore, under this arrangement, there is a voltage drop along the longitudinal direction of each wiring pattern. Owing to the voltage drop, a difference in density occurs in the printed dots.
Japanese Patent Laid-Open Publication No. Hei 2-286261 (Japanese Patent Publication No. Hei 4-17797) proposes a line type thermal print head developed to solve the above-mentioned problem (Related Art 1). FIG. 12 shows the outline of this line type thermal print head. In FIG. 12, reference numeral 201 denotes a head circuit board, 202 a heating resistor, 203 a common wiring pattern, 205 driver elements, and 207 a ground wiring pattern, with no individual circuits depicted. As shown in FIG. 12, the ground wiring pattern 207 is divided substantially at the center of the head circuit board 201 into a right-side ground wiring pattern 207a and a left-side ground wiring pattern 207b. A pair of ground connection terminals 208 and a pair of common-wiring connection terminals 212 are formed close to the longitudinal side edge 201b and substantially in the central area in the longitudinal direction of the head circuit board 201. The pair of common-wiring connection terminals 212 are located more towards the inside than the pair of ground connection terminals 208. The pair of ground connection terminals conduct to the pair of ground wiring patterns, respectively, while the common-wiring connection terminals conduct to both ends of the common wiring pattern 203.
In Related Art 1, the voltage drop in the common wiring pattern 203 becomes large

REFERENCES:
patent: 5278580 (1994-01-01), Nishikawa et al.
patent: 5335002 (1994-08-01), Nagahata et al.
patent: 5568174 (1996-10-01), Nagahata et al.

Affiliated with

Also associated with

Rating

Linear thermal print head and linear thermal print head apparatu does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Linear thermal print head and linear thermal print head apparatu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Linear thermal print head and linear thermal print head apparatu will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-403938