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US 7,612,690 B2Granted
Method and apparatus for scanning a key or button matrix
AssigneeCypress Semiconductor Corporation
InventorsDavid G. Wright, Ray Asbury
Life of this patent
Estimating the term…
Abstract
An improved key matrix scanning technique conducts a first pre-scan on a first array of connections in a key matrix to identify any activated keys or buttons associated with the first array. A second sub-scan is conducted on a second array of connections in the key matrix but only for the connections in the first array that are detected as having activated keys.
Claims20
A method comprising:
- conducting a pre-scan of a connection-matrix having rows and columns that are connectable upon activation of one or more keys or buttons, wherein the pre-scan is capable of identifying either a row or a column of the connection-matrix that corresponds to an activated key or button;
- and
- when at least one row or column is identified in the pre-scan as corresponding to the activated key or button, conducting a sub-scan of the identified row or column to locate a particular row-column connection that corresponds to the activated key or button.
A device comprising:
- processing circuitry configured to conduct a first scan of a connection-matrix to identify either a row or a column of the connection-matrix corresponding to an activated connection, and to conduct a second scan of the row or column identified in the first scan to identify a particular key or button in the connection-matrix that corresponds to the activated connection.
A method comprising:
- identifying either a row or a column in a connection-array that corresponds to an activated key or button;
- and
- sub-scanning the identified row or column in the connection-array to locate the key or button in the connection-array that is activated.
Dependencies are inferred from the claim text.