Misoperation preventing device for optical touch screen and optical touch screen

The utility model discloses a misoperation preventing device for an optical touch screen and a touch screen. The device comprises a sensor and a signal processing unit; the signal output end of the sensor is connected with the input end of the signal processing unit; the signal processing unit comprises an amplifying circuit, a wave filter, an absolute value converting circuit, a peak envelope detection circuit, a comparator and a microprocessor; and the amplifying circuit, the wave filter, the absolute value converting circuit, the peak envelope detection circuit, the comparator and the microprocessor are connected in series sequentially. The misoperation preventing device for the optical touch screen can effectively shield mistaken touch operations, and the optical touch screen using the device inputs information more accurately.