| 摘要 |
An automatic focusing apparatus of the type having an infrared light source for illuminating a subject wherein a position sensor for sensing infrared light reflected from the subject passing through two different portions of the picture-taking lens is provided to generate signals which represent condition of the picture-taking lens, that is, whether an image of the subject is in the best focus, front focus or rear focus. The position sensor comprises two position-sensing devices. By detecting the difference between the outputs from these two position-sensing devices, the condition of the picture-taking lens can be determined. A single position-sensing device can be used if AC signals are generated by a mechanical chopper in the forward position therefrom.
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