| 摘要 |
PURPOSE:To obtain a contrast by which a focus can be detected in a focus detecting device corresponding to many kinds of photographing lenses by arranging a pattern having small dimension in a central part and arranging a pattern having large dimension in a peripheral part. CONSTITUTION:A light source, a projection pattern 21 arranged just before the light source and a light projecting lens 20 which projects the projection pattern 21 on an object are provided. The projection pattern 21 is suitable for an illuminating device for detecting focus used with the automatic focus detecting device of a camera which executes the detection of focus by receiving a light beam which passes through an interchangeable photographing lens. And the pattern 21 is constituted by arranging the light untransmitting pattern having small dimension which is suitable for the photographing lens whose focal distance is long in the central part of a light transmitting substrate and arranging the light untransmitting pattern having large dimension which is suitable for the photographing lens whose focal distance is short in the peripheral part of the substrate. At the time of projecting the pattern on the object, the image of the projection pattern can give the contrast by which the focus can be detected to the focus detecting device corresponding to many kinds of photographing lenses from the photographing lens whose focal distance is short to the lens whose focal distance is long. |
