Industrial Technology Research Institute

Hsien-Yei Chen

Chieh-Yu Lin

Han-Chieh Chang

Ting-Yao Chen

Chung-Mu Hwang

Ruey-Yang Wang

Jung-Lung Chang

Jyh-Jye Jeng

A method and apparatus for the automatically inspecting the contours of a gear for manufacturing errors. According to the method, a gear to be inspected is imaged on an imaging surface to form a gear image. A digitized image indicative of the gear image is generated. The digitized image comprises a plurality of pixels. The pixels each have a gray value and coordinates which represent the location of the pixel within the digitized image. Each pixel is classified into a first or a second class by comparing the gray value of the pixel to a predetermined threshold value. The coordinates of pixels corresponding to the contours of the gear are determined from the classes of pixels. The manufacturing errors of the gear are calculated by comparing the coordinates of the pixels corresponding to the contours of the gear to a standard gear pattern. The apparatus, in its preferred embodiment, includes a base and collimated light source to illuminate the gear, a microscope to magnify an image of the gear and a CCD camera to generate a digitized image indicative of the magnified gear image. A digital computer is also included to assign a gray value to each pixel in the digitized image, to classify each pixel into a first or second class by comparing the gray value of the pixel with a predetermined threshold value, to determine the coordinates of pixels corresponding to the contours of the gear and to calculate the manufacturing errors of the gear by comparing the coordinates of pixels corresponding to the contours of the gear with a standard gear pattern. The manufacturing errors include runout error, pitch error and profile error.

Method and apparatus for inspecting the contours of a gear

A real-time apparatus for detecting surface defects on a moving object under test comprises a high-frequency linear light source for generating linear light which is focused on a line position of the tested object, a linear CCD (charge coupled device) camera for scanning the line position and generating an image signal, an image-signal processing device for converting the analog image signal to digital image signal and further converting the digital signal to a HIGH or a LOW signal, a combination of the HIGH and LOW signals constituting constituting binary image data in the form of binary pulses, an image-storing circuit connected to the image-signal processing circuit for storing the binary image data, a defect-detecting unit for detecting if an area unit has a valid defect which meets one of a set of predetermined defect patterns or detecting statistical defects which are not valid defects but a plurality of small defects combined together still counted as defects, and a defect detecting statistic unit connected to the image-storing circuit for calculating a total amount of defect, and the area and location of each defect by a well-known connectivity analyzation process.

Real-time apparatus for detecting surface defects on objects

Growing community of inventors

Hsinchu Hsien, Taiwan

Hsien-Yei Chen