Patent ID: 8004659

Claim:
A focusing method of a vision measuring machine, the focusing method comprising: providing: a stage supporting a workpiece; an image capturing device movable relative to the stage; and a laser ranging module movable relative to the stage, and emitting a laser beam directed to the workpiece; selecting a measuring point on the workpiece surface; moving the laser ranging module to locate a laser spot formed by the laser beam at the measuring point; getting a Z-axis coordinate of the laser spot in a Cartesian coordinate system with the laser ranging module; focusing the image capturing device on the measuring point of the workpiece according to the Z-axis coordinate of the laser spot; getting Z-axis coordinates of the image capturing device and the laser ranging module, and measuring the distance between the laser spot and the laser ranging module with the laser ranging module; wherein the Z-axis coordinate of the laser spot is calculated according to the distance between the laser spot and the laser ranging module, and the Z-axis coordinate of the laser ranging module.