Telephonic communications – Supervisory or control line signaling – Substation originated
Patent
1995-09-11
1997-08-26
Chiang, Jack K.
Telephonic communications
Supervisory or control line signaling
Substation originated
379428, 379429, H04M 100
Patent
active
056617933
ABSTRACT:
A key unit is provided with a first print substrate on which a contact portion and a LED capable to be mounted on flat surface are mounted, a conductive contact rubber, placed on the first print substrate, having a movable contact portion which can contact with the contact portion and an open portion in which the LED is accommodated, a key button placed on the conductive contact rubber, a LED lens, placed on the edge portion of the open portion of the conductive contact rubber, which leads the light beam generated from the LED in the open portion, and a key case having a through hole into which the key button is slidably inserted and a lens insertion hole into which the LED lens is inserted. The key unit may also be provided with a chip resistor to protect the LED, which is mounted on the first print substrate at a position below a lower end face of the key case. Further, a key button may be inserted into the through hole and a position where the LED lens is inserted into the lens insertion hole, the width of the LED lens is made to be shorter than that of the LED.
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Akimoto Toshimi
Hoshi Ichiro
Imai Junichiro
Ishida Takuya
Oono Fumiyoshi
Chiang Jack K.
Hitachi Telecom Technologies Ltd.
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