APPARATUS AND METHOD FOR INSPECTING CAPACITIVE TOUCH SCREEN PANEL USING PHASE LOCKED LOOP

摘要

PURPOSE: An apparatus for testing an electrostatic touch screen panel using a PLL(Phase Locked Loop) and a method thereof are provided to assure generality of a test equipment by testing the electrostatic touch screen panel using a PLL, and to improve robustness and test reliability as to electrical and mechanical impact and external environmental change. CONSTITUTION: A frequency signal generation part(110) generates a first frequency signal by a generic electrostatic capacity, and generates a second frequency signal by synthesized electrostatic capacity of generic electrostatic capacity and electrostatic capacity between ITO(Indium Tin Oxide) sensor electrodes of the electrostatic touch screen panel. A PLL circuit part(120) synchronizes an output frequency of a VCO(Voltage Controlled Oscillator) to a frequency of an input signal by inputting a signal generated by the frequency signal generation part as the input signal. A non-defection judgment part(130) judges non-defection of the electrostatic touch screen panel by comparing the amount of output voltage change of the VCO with amount of reference change. [Reference numerals] (110) Frequency signal generation part; (116) Frequency oscillation part; (120) PLL circuit part; (122) Phase detection part; (124) Voltage control oscillation part; (126) Divider part; (130) Non-defection judgment part; (132) A/D converter(24bit); (134) Voltage change comparison part; (136) Frequency comparison part; (140) Monitoring part