Imaging definition which CCD camera works in limited distance was solved by using hyperfocal distance.Telecentric optical system was employed in order to solve the precision of measuring systems.

• 用超焦距方法解决了CCD像机对有限远距离范围内工作时的成像清晰度问题,采用了像方远心光路设计解决了系统测量精度问题。