Driving circuit for matrix electrode for detecting fingerprint pattern

Abstract

Abstract PURPOSE:To form many line electrodes at a small space and to detect a fine fingerprint pattern by maintaining a line electrode, in which a driving signal is not impressed, to the constant potential of a low impedance. CONSTITUTION:When in order to detect a fingerprint pattern, a finger is put on a fingerprint input plate 10 and pressed to the plate, a crossover position A is not pressurized, and other crossover positions B, C and D are pressurized by the line of the fingerprint. At present, in order to discriminate the pressurization condition of the crossover position A, a driving signal is outputted from a data driver 11 to a line electrode KD2, a data receiver 14 selects a line electrode KR1, and then, a driving signal to flow at the line electrode KD2 flows to a line electrode KD3 at the ground potential through resistances R2 and R3 of the pressurized crossover positions B and C as shown by a broken line and does not sneaking at the line electrode KR1. Since the crossover position D is pressurized and the line electrode KD3 becomes the ground potential, the sneaking to the line electrode KR1 is not executed. Thus, the sneaking preventing element of the signal is not made unnecessary and a high density matrix electrode is obtained.

Inventors

• 👤 Teruhiko Tamori
• 👤 田森　照彦

Bibliographic Details