| 摘要 |
Disclosed is an improvement in an automatic focusing system for use with an optical instrument having a focusable objective which is adjustable in response to optical and electronic components of the system for determining object distance of a remote subject by comparing images of scanning and reference optical systems. The scanner of the optical system is driven oscillatably across an angle to detect a subject between infinity and the minimum focus condition of the objective lens. The present invention relates to improvements in an automatic focusing system for use with an optical instrument having a focusable objective. More particularly, the improvement relates to driving the focusing system to a preset fixed focus setting when the system senses difficult conditions for focus detection as those having low contrast or complex subject matter. |
