Incremental printing of symbolic information – Thermal marking apparatus or processes – Specific resistance recording element type
Reexamination Certificate
2000-10-06
2002-06-11
Barlow, John (Department: 2861)
Incremental printing of symbolic information
Thermal marking apparatus or processes
Specific resistance recording element type
Reexamination Certificate
active
06404453
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a thermal printhead for performing printing by selectively heating up a plurality of heating dots. The invention also relates to a clip pin used for a thermal printhead.
2. Description of the Related Art
As is known in the art, thermal printhead are designed to selectively supply heat energy to thermosensitive paper or transfer ink ribbon for performing printing.
FIG. 13
of the accompanying drawings shows the principal components of a conventional thermal printhead. As illustrated, this conventional printhead includes an insulating primary substrate
1
′, a secondary substrate
2
′, and a plurality of clip pins
3
′ for establishing electrical connection between the primary and the secondary substrates.
The primary substrate
1
′ supports drive ICs
6
′ covered by a protection coat
7
′. The drive ICs
6
′ control the operation of a heating resistor
5
′ formed on the upper surface of the substrate
1
′. The heating resistor
5
′ is divided into a multiplicity of small portions or “heating dots” which are selectively heated up by the drive ICs
6
′ in accordance with given print data.
In the conventional printhead, a plurality of terminals
8
′, connected to e.g. the drive ICs
6
′, are provided along the right edge of the substrate
1
′. Each of the terminals
8
′ is held in contact with the clip portion
3
b
′ of a relevant one of the clip pins
3
′. The lead portion
3
a
′ of each clip pin
3
′ extends horizontally from the clip portion
3
b
′ to be connected to one of the terminal pads
9
′ formed on the upper surface of the secondary substrate
2
′. The terminal pads
9
′ are connected via a wiring pattern (not shown) to a connector
10
′ attached to the lower surface of the secondary substrate
2
′. In operation, a data transmission cable (not shown), which may be connected to a host computer, is plugged into the connector
10
′ for supplying the drive ICs
6
′ with signals, data etc. required for performing printing.
The conventional printhead has been found disadvantageous in the following points.
Referring to
FIG. 14
of the accompanying drawings, the lead portion
3
a
′ of each clip pin
3
′ has a uniform thickness over the entire length thereof. Thus, each clip pin
3
′ is rendered rather rigid, so that it will not be bent even when an external force is exerted on the lead portion
3
a
′ (see the arrows A in FIG.
13
). The exertion of such external force may occur when the user of the printhead tries to plug a flexible cable into the connector
10
′.
Upon application of such external force on the lead portion
3
a
′, the clip portion
3
b
′ of the clip pin
3
′ may be unduly dislocated on the terminal
8
′, thereby causing the so-called called “loose contact” in relation to the terminal
8
′. In an extreme case, the clip portion
3
b
′ may even be wrenched off the edge of the primary substrate
1
′.
SUMMARY OF THE INVENTION
The present invention has been proposed under the circumstances described above, and an object of the present invention is to provide a clip pin capable of overcoming the above problems. Another object of the present invention is to provide a thermal printhead using such clip pins.
According to a first aspect of the present invention, there is provided a thermal printhead which includes: a first substrate provided with a heating resistor; a second substrate spaced from the first substrate; and a plurality of connectors bridging between the first and the second substrates. Each connector is formed with an elongated lead portion which is provided with a bend-facilitating part and a relatively rigid part.
According to a preferred embodiment of the present invention, the bend-facilitating part is smaller in thickness than the rigid part.
Preferably, the bend-facilitating part may be greater in width than the rigid part. Further, the bend-facilitating part may be generally equal in cross-sectional area to the rigid part.
The bend-facilitating parts of the respective connectors may be arranged in a single line. More preferably, the bend-facilitating parts may be arranged in at least two lines. In either case, all of the bend-facilitating parts may be disposed between the first and the second substrates.
Preferably, each connector may be provided with a clip portion formed integral with the lead portion.
According to a second aspect of the present invention, there is provided a clip pin for connecting separate electrical units. The clip pin includes: a generally straight lead portion; and a clip portion formed at an end of the lead portion. The lead portion is provided with a bend-facilitating part which is smaller in thickness than a remaining part of the lead portion.
Preferably, the clip portion may include an upper holding part and a lower holding part spaced vertically from the upper holding part. Further, the bend-facilitating part may have a principal surface whose normal extends generally vertically.
Other features and advantages of the present invention will become apparent from the detailed description given below with reference to the accompanying drawings.
REFERENCES:
patent: 4470648 (1984-09-01), Davis et al.
patent: 5167513 (1992-12-01), Johnson et al.
patent: 5739837 (1998-04-01), Nagahata et al.
patent: 5835358 (1998-11-01), Brakus
patent: 6206718 (2001-03-01), Takahashi et al.
Obata Shinobu
Yoshikawa Yasuhiro
Barlow John
Bednarek Michael D.
Feggins K.
Rohm & Co., Ltd.
Shaw Pittman LLP
LandOfFree
Thermal printhead and clip pin used for the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermal printhead and clip pin used for the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermal printhead and clip pin used for the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2983429