Light-emitting device mounted under keybuttons of a keyboard

• US 4,491,692 A
• Filed: 11/05/1982
• Issued: 01/01/1985
• Est. Priority Date: 11/05/1982
• Status: Expired due to Fees

• Current Assignee: Shan S. Lee
• Original Assignee: Shan S. Lee
• Inventors: Lee, Shan S.
• Primary Examiner(s): SCHREYER, STAFFORD
• Application Number:
  US06/439,407
• Time in Patent Office: 788 Days
• Field of Search: 179/90 L, 179/81 C, 179/84 L, 179/94, 179/90 K, 179/178, 200/314, 340/365 R, 362/24, 362/30, 362/84
• US Class Current: 362/24
• CPC Class Codes: H04M 1/22 Illumination; Arrangements for improving the visibility of characters on dials

Abstract

The present invention relates to a light-emitting device mounted under the keys of a keyboard, particularly to a device which emits light by using the effect of light-emitting diodes which are mounted below every key of a keyboard. When a user picks up the handset of a telephone or when the switch of a device is turned on, a closed circuit which emits light is formed so that the user can clearly see the symbols on the keys with the help of the light emitted by the light-emitting diodes. When the handset is placed on the telephone set, the power supply is cut off. Thus, the object of being able to telephone in darkness without difficulty is accomplished.

Claims

1. A keyboard comprising a plurality of keys;

a power switch;

a plurality of light emitting diode means, each light emitting diode means being mounted beneath a corresponding key;

a plurality of conductive rubber pads having an opening therethrough, each rubber pad being positioned above each of said light emitting diode means; and

an insulated elastic rubber dome sheet having open portions surrounded by projecting portions, said dome sheet being positioned above said conductive rubber pads, such that said conductive rubber pads and said dome sheet are positioned between said light emitting diode means and said keys for preventing pressure on said light emitting diode means when said keys are activated;

wherein when said power switch is on, said light emitting diode means are operative to emit light which passes through the openings in said rubber pads and dome sheet thereby illuminating said keys from below; and

wherein when said power switch is off, said light emitting diode means are not operative and said keys are not illuminated.

2. A keyboard as set forth in claim 1, wherein each of said light emitting diode means comprises a light emitting diode and an activating circuit, positioned in the center of the contact area of a switching circuit of a corresponding said key.

3. A keyboard as set forth in claim 1, wherein said projecting portions of said rubber dome sheet have a shape corresponding to the shape of the bottom of said keys.