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US 4,075,449 AGranted
Switch with electroluminescent indicator
AssigneeNgk Spark Plug Co., Ltd.
InventorsHideaki Yagi, Tetsuo Hishiki
Life of this patent
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Abstract
Electroluminescent elements comprising a ferroelectric sintered ceramic body as a substrate, a luminescent layer applied on the body, a transparent electrode layer applied on the luminescent layer and an electrode layer applied on other side of the body and having improved withstand voltage properties. The electroluminescent elements are suitable for the indication of location of switch members or the like at the switching-off condition.
Claims13
An electrical switch including an electro-luminescent element for visually indicating when the switch is in its OFF condition, comprising:
- an OFF-ON actuator mounted for pivotal movement between OFF and ON positions, switch contacts for connection to an external supply of electricity, and switching means actuatable by said actuator between OFF and ON conditions;
- said actuator including an electroluminescent element comprising a ferroelectric sintered ceramic substrate, a luminescent layer applied on one surface of said substrate, a transparent electrode layer applied over the surface of said luminescent layer, and another electrode on the opposite side of said substrate;
- said actuator being at least semi-transparent so that light from said luminescent layer may be seen outside of said switch and actuator;
- said electroluminescent element being electrically connected in parallel with said switching means so that current will flow through only one of them at any time, said luminescent layer thereby emitting light only when said switch is in its OFF condition.
1 more element
Dependencies are inferred from the claim text.