Industrial Technology Research Institute

National Taipei University of Technology

Jin-Liang Chen

Chung-Chu Chang

Liang-Chia Chen

Yao-Ting Huang

Shih-Hsuan Kuo

Hung-Ming Tai

Huang-Wen Lai

Ching-Ming Yeh

Huang-Chi Huang

Yong-Tong Zou

Chung Chu Chang

Chun-Tai Lien

Chi Hong Tung

Shih-Fang Lee

The present invention relates to a method for image calibration and an apparatus for image acquiring. In the method for image calibration, the image formation position for an image acquiring unit of the apparatus is calibrated according to the relative location of the image acquiring unit to a objective lens of the apparatus, wherein the relative location is determined by calculating the focus index of the image acquired by the image acquiring unit so that a clear and sharp interferogram can be obtained for three dimensional surface profile measuring. In addition, it is possible to obtain a clear and sharp image without any interference fringe outside the coherent range by adjusting the image formation position, which is capable of being utilized for two dimensional defect detection and dimension measurement.

Method for image calibration and apparatus for image acquiring

A method for out-of-plane displacement detection is disclosed. The out-of-plane displacement is detected by analyzing all the fringe density indexes calculated using the frequency-domain information extracted from a series of interference images of the sample vibrating at different frequencies. The present invention further discloses a method and an apparatus for resonant frequency identification by detecting the peak value of all the fringe indexes calculated at different scanning frequencies. With the identified resonant frequency, the full-field vibratory surface profile of the sample in various resonance modes can be reconstructed.

Method and apparatus for resonant frequency identification through out-of-plane displacement detection

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 identifying dynamic characteristics of a vibratory object is provided in the present invention, in which a series of dynamic interference images of the vibratory object is acquired through a frequency sweeping procedure and a two-dimensional image scanning procedure. Thereafter, the acquired images are processed for obtaining the corresponding differential fringe density index by signal processing technique of band-pass filtering method so as to further identify the dynamic characteristics of the vibratory object.

Method and apparatus for identifying dynamic characteristics of a vibratory object

An autofocus searching method includes the following procedures. First, focus values of images, which are acquired during the movement of the object lens, are calculated, in which the focus value includes at least the intensity value of the image derived from the intensities of the pixels of the image. Next, focus searching is based on a first focus-searching step constant and a first focus-searching direction, in which the first focus-searching step constant is a function, e.g., the multiplication, of the focus value and a focus-searching step size. If the focus searching position moves across a peak of the focus values, it is then amended to be based on a second focus-searching direction and a second focus-searching step constant, in which the second focus-searching step constant is smaller than the first focus-searching step constant, and the second focus-searching direction is opposite to the first focus-searching direction.

Autofocus searching method

The invention relates to a tilting adjustable surface profilometer, comprising an apparatus capable of adjusting an image acquiring angle. The apparatus includes two types of frameworks. One is a translation-stage-type tilting adjustable surface profilometer, which is enabled by the translations of two translation stage with the rotation of a rotary rack, a surface profile with an omni-directional angle of a sample can be obtained. The other framework is a surface profilometer with an arc-trajectory tilting apparatus, which is enabled by guiding the surface profilometer to slide along the arc rails with the rotations of the rotary rack, a surface profile with an omni-directional angle of a sample can be obtained.

Tilting adjustable surface profilometer

The present invention relates to a signal analysis method for vibratory interferometry to identify the vibratory characteristics of an object under test. A vibratory stroboscopic interferometric signal of an object under vibration is obtained. The vibratory stroboscopic interferometric signal is analyzed with a deconvolution operation to obtain a reformed vibratory stroboscopic interferometric signal.

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Hsinchu, Taiwan

Jin-Liang Chen