Patent ID: 6477903
Filing Date: 2002-11-12
Classification: B81B,G01L,G01P

Abstract:
A force detector comprising:a flexible substrate including a fixed portion fixed to a detector casing, a working portion to which a force to be detected is transmitted, and a flexible portion having flexibility formed between said fixed portion and said working portion, a fixed substrate fixed on said detector casing so as to face such flexible substrate, a working body to receive a force to be detected and to transmit said force to said working portion of said flexible substrate, a displacement electrode formed on a surface, which faces to said fixed substrate, and a fixed electrode formed on a surface, which faces to said flexible substrate, of said fixed substrate, wherein any one or both of said displacement electrode and said fixed electrode are constituted by four localized electrodes to form four capacitance elements by using said four localized electrodes, respectively, a first localized electrode to form a first capacitance element being located in a positive area with respect to a first axis of coordinates, a second localized electrode to form a second capacitance element being located in a negative area with respect to said first axis, a third localized electrode to form a third capacitance element being located in a positive area with respect to a second axis of coordinates, a fourth localized electrode to form a fourth capacitance element being located in a negative area with respect to said second axis, said first axis and said second axis being perpendicular to each other on a surface where said localized electrodes are formed, a first force component which makes an electrode distance of said first capacitance element smaller than an electrode distance of said second capacitance element and a second force component which makes said electrode distance of said second capacitance element smaller than said electrode distance of said first capacitance element being detected by a difference between electrostatic capacitance values of said first and second capacitance elements.