×

Coordinate reading device

  • US 6,778,167 B2
  • Filed: 09/04/2001
  • Issued: 08/17/2004
  • Est. Priority Date: 09/04/2000
  • Status: Expired due to Term
First Claim
Patent Images

1. A coordinate reading device, comprising:

  • a coordinate input sheet that has a coordinate input area for inputting a coordinate by a coordinate input device generating an alternating magnetic field, and a plurality of loop coils laid under the coordinate input area;

    a coil detecting device that detects a coil that generates a maximum signal level and a coil that generates a first signal level that is a larger signal level generated from one of coils adjacent to the coil generating the maximum signal level, in accordance with a strength of the alternating magnetic field generated from the coordinate input device;

    a first storage device that stores a first relationship between the maximum signal level and the first signal level and a second relationship between the first relationship and a distance between a predetermined position and the coordinate input device on the coordinate input area;

    a reading controller that reads a distance, corresponding to the first relationship obtained based on the detected maximum signal level and the first signal level, from the first storage device, and reads a positional coordinate of the coordinate input device on the coordinate input plane based on the read distance;

    a signal level detecting device that detects a second signal level in which two signal levels detected from coils adjacent to each other of the plurality of coils are substantially equal to each other, in accordance with the strength of the alternating magnetic field;

    a signal level calculating device that calculates a third relationship between a third signal level and a fourth signal level which are generated from at least two coils adjacent to the outside of the adjacent coils generating the second signal level detected by the signal level detecting device;

    a second storage device that stores relationships between the second signal level and the third relationship and a correction; and

    a correcting device that corrects the second relationship stored in the first storage device by reading the correction, corresponding to the second signal level detected by the signal level detecting device and the third relationship calculated by the signal level calculating device, from the second storage device.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×