KEYBOARD CIRCUIT
First Claim
1. A keyboard circuit, comprising:
- a central processing unit (CPU);
a plurality of keys aligned in a matrix fashion of n rows and m columns, where n and m are natural numbers;
n first resistors corresponding to the n rows keys;
m second resistors corresponding to the m columns keys;
a first voltage output terminal;
a second voltage output terminal; and
a detection resistor;
wherein a first contact of each of the plurality of keys aligned in a same column is electronically connected to the first voltage output terminal by a corresponding second resistor, a second contact of each of the plurality of keys aligned in the same column is grounded by the detection resistor;
the first contact of each of the plurality of keys aligned in a same row is electronically connected to the second voltage output terminal by a corresponding first resistor;
the CPU is grounded by the detection resistor and the first voltage output terminal alternates with the second voltage output terminal to output a voltage under control of the CPU.
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Accused Products
Abstract
A keyboard circuit includes a CPU, a plurality of keys aligned in n rows and m columns, n first resistors, m second resistors, a first voltage output terminal, a second voltage output terminal, and a detection resistor. A first contact of each of the plurality of keys in a column is electronically connected to the first voltage output terminal by a second resistor, and a second contact of each of the plurality of keys in the column is grounded by the detection resistor. The first contact of each of the plurality of keys in a row is electronically connected to the second voltage output terminal by a first resistor. The CPU is grounded by the detection resistor and the first voltage output terminal alternates with the second voltage output terminal to output a voltage under control of the CPU.
23 Citations
16 Claims
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1. A keyboard circuit, comprising:
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a central processing unit (CPU); a plurality of keys aligned in a matrix fashion of n rows and m columns, where n and m are natural numbers; n first resistors corresponding to the n rows keys; m second resistors corresponding to the m columns keys; a first voltage output terminal; a second voltage output terminal; and a detection resistor; wherein a first contact of each of the plurality of keys aligned in a same column is electronically connected to the first voltage output terminal by a corresponding second resistor, a second contact of each of the plurality of keys aligned in the same column is grounded by the detection resistor;
the first contact of each of the plurality of keys aligned in a same row is electronically connected to the second voltage output terminal by a corresponding first resistor;
the CPU is grounded by the detection resistor and the first voltage output terminal alternates with the second voltage output terminal to output a voltage under control of the CPU. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A keyboard circuit, comprising:
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a central processing unit (CPU); a plurality of keys aligned in a matrix fashion of n rows and m columns, n and m are natural numbers; n first resistors corresponding to the n rows; m second resistors corresponding to the m columns; a first voltage output terminal electronically connected the m second resistors; a second voltage output terminal electronically connected the n first resistors; and a detection resistor; wherein each first resistor is connected to the detection resistor by any one of the keys located in a same row with the first resistor;
each second resistor is connected to the detection resistor by any one of the keys located in a same column with the second resistor;
the CPU is grounded by the detection resistor and the first voltage output terminal alternates with the second voltage output terminal to output a voltage under control of the CPU. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A keyboard circuit, comprising:
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a central processing unit (CPU) comprising a first voltage output terminal and a second voltage output terminal; a plurality of keys aligned in a matrix fashion of n rows and m columns, n and m are natural numbers; n first resistors corresponding to the n rows; m second resistors corresponding to the m columns; and a detection resistor; wherein a first contact of each of the plurality of keys aligned in a same column is electronically connected to the first voltage output terminal by a corresponding second resistor, a second contact of each of the plurality of keys aligned in the same column is grounded by the detection resistor;
the first contact of each of the plurality of keys aligned in a same row is electronically connected to the second voltage output terminal by a corresponding first resistor;
the CPU is grounded by the detection resistor and the first voltage output terminal alternates with the second voltage output terminal to output a voltage under control of the CPU. - View Dependent Claims (14, 15, 16)
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Specification