Abstract: An optical touch apparatus and a touch method thereof are provided. A plurality of light sensing units are disposed between a first scanning light source and a second scanning light source, wherein the light sensing units, the first scanning light source and the second scanning light source are disposed at a same side of a touch surface. A touch position of an input tool is determined according to an intensity of a scattered light generated by an input tool and sensed by the light sensing units and generated when a first scanning beam and a second scanning beam scan the input tool.

Abstract: An optical touch device defining a sensing area includes two scanning modules and a light detecting element. The scanning modules respectively disposed on terminals of a first side of the sensing area include light-emitting elements and reflective elements. The light-emitting element is used for emitting a detective light along a first pathway and the reflective element has a reflective surface for reflecting the detective light such that the detective light is emitted along a second pathway. There is an angle forming between the first side and the second pathway and the reflective surface changes a direction of the second pathway such that the detective light scans in the sensing area. The detective light has a first intensity and a second intensity, in which the first intensity is less than the second intensity. The light detecting element is used for receiving a detective light reflected by an object.

Abstract: A laser scanning device and a control method thereof are provided. The method includes: providing a control signal to an oscillating reflective mirror of the device; setting a frequency of the control signal gradually decreased from a maximal-setting-value of a resonant frequency of the mirror; judging whether a light detector receives a laser light reflected by the mirror according to an edge signal of the detector; judging whether a pulse width of the edge signal is equal to a predetermined pulse width when the detector receives the laser light: (1) increasing the frequency of the control signal when the pulse width of the edge signal is greater than the predetermined pulse width, (2) decreasing the frequency of the control signal when the pulse width of the edge signal is less than the predetermined pulse width. The time and labor for measuring the scanning frequency of the mirror may be saved.