×

Capacitance detector circuit, capacitance detection method, and fingerprint sensor using the same

  • US 20050073324A1
  • Filed: 09/14/2004
  • Published: 04/07/2005
  • Est. Priority Date: 10/02/2003
  • Status: Active Grant
First Claim
Patent Images

1. A circuit of a capacitive sensor having a plurality of column lines and a row line intersecting the column lines, for detecting a change in capacitance at an intersection of a column line and a row line, the circuit comprising:

  • code generating means for generating a code having orthogonality in time sequence to output the generated code as a column drive signal;

    column line drive means for driving a plurality of column lines, from among the column lines that are selected in response to the code;

    capacitance detecting means, connected to the row line, for detecting a voltage by converting a total sum of changes in capacitance at intersections of the selected column lines into the voltage to output the detected voltage; and

    decode processing means for performing a predetermined calculation on the detected voltage output from the capacitance detecting means and the code to determine a voltage value responsive to the capacitance change at the intersection.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×