Industrial Technology Research Institute

National Taipei University of Technology

Huang-Wen Lai

Liang-Chia Chen

Jin-Liang Chen

Shih-Hsuan Kuo

Sheng-Lih Yeh

Huang-Chi Huang

Yong-Tong Zou

Chun-Tai Lien

Leh-Rong Chang

An embodiment of an autofocus system is provided, including a height detection module, an image detection module, a movement unit and a processing unit. The height detection module is arranged to output a plurality of detection lights along a Z axis direction, wherein each of the detection lights has different focal lengths and different wavelengths such that the height detection module generates a dispersion region along the Z axis direction. The image detection module is arranged to capture an image of the focus position. The movement unit is arranged to move an object along the Z axis direction, wherein the object has an internal surface and an external surface. The processing unit determines whether the external surface and the internal surface are within the dispersion region according to the quantity of the energy peaks of a reflectance spectrum received by the height detection module.

Autofocus system and autofocus method

A exemplary method for determining vibration displacement in interferometric scanning, in which two optical signals having a phase difference with each other of a high-coherence interferogram corresponding to a tested surface is detected for determining a shifting displacement between the reference plane of interferometric apparatus and the tested surface. In one embodiment, a series of the shifting displacements with respect to a time interval are measured for determining the vibrating frequency of the tested surface by spectrum analysis. Meanwhile, an exemplary interferometric apparatus is also disclosed for calculating the relative position between the tested surface and the reference plane of interferometric apparatus whereby the interferometric apparatus is capable of compensating influences of vibration caused by the environment or the tested surface itself so as to obtain the surface profile and vibration frequency of the tested surface.

Method for determining vibration displacement and vibrating frequency and apparatus using the same

A method and apparatus for simultaneously acquiring interferograms created with a plurality of different interference conditions are provided in the present invention. In the present invention, an object beam and a reference beam are used to interfere with each other and there are a plurality of sub-fields of interference simultaneously generated. All the sub-fields of interference can be simultaneously acquired by an image acquiring device with single shooting action so as to form the plurality of interferograms. Moreover, the present invention also provides a method for solving the phase information of the object beam from the interferograms formed by the foregoing said method.

Method and apparatus for simultaneously acquiring interferograms and method for solving the phase information

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Taipei County, Taiwan

Huang-Wen Lai