Keypad apparatus
First Claim
Patent Images
1. A keypad apparatus containing a plurality of keys, the keypad apparatus comprising:
- a lightpipe having at least two sides and a coating disposed upon a first side of said lightpipe reflecting light inside said lightpipe; and
an electrical keypad circuit disposed upon a second side of said lightpipe and the plurality of keys disposed upon a portion of said electrical keypad circuit and said second side of said lightpipe.
1 Assignment
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Accused Products
Abstract
A keypad apparatus for a radio telephone has the keypad circuit (200) inked onto the lightpipe (105), thereby, allowing freedom in designing the shape of the keypad (103) and reducing the amount of circuitry required on the main circuit board (109) contained within the housing (107) of the radiotelephone.
94 Citations
23 Claims
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1. A keypad apparatus containing a plurality of keys, the keypad apparatus comprising:
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a lightpipe having at least two sides and a coating disposed upon a first side of said lightpipe reflecting light inside said lightpipe; and an electrical keypad circuit disposed upon a second side of said lightpipe and the plurality of keys disposed upon a portion of said electrical keypad circuit and said second side of said lightpipe. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A radiotelephone in a system which allows the radiotelephone to initialize phone calls, the radiotelephone comprising:
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a circuit board disposed within a housing of the radiotelephone; a lightpipe having at least two sides and secured to said housing; a coating disposed upon a first side of said lightpipe reflecting light inside said lightpipe and shielding electromagnetic and radio frequency interference; a plurality of keys forming a keypad, such that phone calls may be initialized; an electrical keypad circuit disposed upon a second side of said lightpipe, said plurality of keys disposed upon a portion of said electrical keypad circuit and said second side of said lightpipe, and said electrical keypad circuit coupled to said circuit board; and a keypad bezel mechanically coupled to said housing and securing said plurality of keys between said lightpipe and said bezel. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. A keypad circuit for use in a keypad apparatus, the keypad circuit further comprising:
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a lightpipe in the keypad apparatus; a first conductive trace having a first end and coupled to a first side of said lightpipe; a first plurality of resistors coupled electrically in series with said first conductive trace and coupled to said first side of said lightpipe; a first power supply including a voltage source having at least one output and a resistor having a first and a second end, said first end of said resistor coupled to one of said at least one output and said second end coupled to said first end of said first conductive trace; a second conductive trace coupled to an electrical ground and said first side of said lightpipe; means, responsive to the activation of a first of a plurality of keys, for coupling said first trace to said second trace and attaining a first voltage level at said first end of said first trace; and means, responsive to the activation of a second of said plurality of keys, for coupling said first trace to said second trace and attaining a second voltage level at said first end of said first trace. - View Dependent Claims (21, 22, 23)
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Specification