| 摘要 |
PURPOSE:To improve the accuracy of range finding especially in a camera for photographing animation etc. by dividing a range finding area of a sensor as required, and finding the distance of a subject from respective area. CONSTITUTION:Signals from a sensor 19 are A/D converted 24, and picture elements are allotted to memories 41-43 in a gate 40. Hpfs of respective areas are calculated in arithmetic units 44-46, and a value k at which Hf makes zero crossing is found. When values of k obtained by arithmetic units 44-46 are k44-k46, circuits 47-49 calculate k44-k45, k44-k46, k45-k46 respectively. On the other hand, a depth calculating circuit 51 calculates the depth under the photographing condition as the width of the values k basing on information of aperture and information of focal distance of photographing lens system. A comparator circuit 50 compares ¦k44-k45¦, ¦k44-k46¦, ¦k45-k46¦ with the value k, and all are less than the value k, all of subject distances are judged to be within the depth of focus. On the other hand, information of distance k44-k46 is evened off 52, and necessary amount of shifting of a lens is calculated by an arithmetic circuit 57 from information of focal distance, etc. and a motor 27 is driven. |
