Patent ID: 7580590

Claim:
An optical image system surface resolution calibration method, comprising the following steps: providing a calibration standard and an image sensor device, the surface of said calibration standard being provided with a plurality of interleaving bright lines and dark lines, said calibration standard being disposed in a plane to be measured, said image sensor device being provided with an imaging means, a memory means, and a logic-arithmetic means; selecting a plurality of sequentially arranged bright lines and dark lines within the effective sensing range of said image sensor device; fetching the image information of the calibration standard and storing the image information by the memory means of said image sensor device; determine the image boundary by the logic-arithmetic means, defining the orthogonal first axis and second axis by utilizing the pixel of the image sensor device as the reference coordinate, and calculating to obtain the number of the selected bright lines and their linear equations, wherein, the parameters related to the linear equation include the slope (a) and the intersection distance (b), thus the slope (a) represents the distance increased along the second axis vs the distance increased along the first axis, while the intersection distance (b) represents the distance from the point the straight line crossing the first axis to the origin of the coordinate; calculating the average distance Δb between adjacent bright lines along the direction of the second axis through said logic-arithmetic means by making use of the intersection distances (b) of the respective bright line linear equations; and calculating and obtaining through said logic-arithmetic means the magnification factor Δb/√{square root over (1+a 2 )} for the image fetched by said image sensor device.