Patent
1981-07-22
1983-01-11
Perkey, William B.
354165, 354197, 354198, G03B 310, G03B 1320
Patent
active
043679340
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Field of the Invention
The present invention relates to a camera including an automatic focusing device which adjusts the focusing of a camera objective or picture taking lens in accordance with a range finding and particular to such apparatus wherein a light from a light source is projected onto a target object, the light reflected therefrom is selectively received by a plurality of light receiving elements, and the object distance is determined in dependence on which light receiving element has received the reflected light.
2. Prior Art
Heretofore, automatic focusing devices have been proposed, such as in U.S. Pat. No. 3,723,003, which devices adjust the focus of a camera objective in accordance with range finding wherein a light emitting element light source is caused to emit a pulse of light, the light pulse reflected from a target object is received by one of a plurality of light receiving elements arranged to respectively receive light from zones at different distances, and the distance to the target object is detected by which element received the light.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a camera including the above type of automatic focusing device which facilitates close-up photography as well.
To attain the object, the camera according to the present invention is arranged such that a light emitting element light source is caused to emit a single light pulse for range finding in ordinary photography, thereby focusing a camera objective or picture taking system. At the same time, the camera is further arranged such that, in the case of close-up photography where the focusing of a picture taking optical system is fixed at a specific distance, the light emitting element is caused to successively emit light pulses for continuous range finding to indicate that the camera and a target object are in the positional relationship most suitable for close-up photography when the fixed distance being focused by the picture taking optical system matches the actual camera-to-target-object distance. According to the present invention, the automatic focusing of the picture taking optical system can be effected in ordinary photography, and at the same time, a continuous range finding operation is performed for close-up photography, the result thereof being indicated to allow easy determination of a relative distance between the camera and a target object with the camera-to-target object distance being changed while the indication of the indicating means is observed thereby enabling easy close-up photography. Additionally, as the light emitting element is caused to emit a light pulse only once for a range finding in ordinary photography, power consumption is saved than in the case when the light emitting element is always caused to succesively emit light pulses.
Furthermore, according to an embodiment of the present invention, a single light emitting element is used for the range findings in both ordinary and close-up photography, resulting in an advantage in terms of space and cost. In addition, in view of the fact that, in close-up photography, it is possible to obtain sufficient accuracy in range finding even if the light from the light emitting element is slightly low in intensity, because a target object is located near the camera, the light for close-up photography is emitted at lower intensity than that for ordinary range finding, thereby saving power consumption, even if the light emitting element emits light successively. In addition, an indication means for the close up focusing is arranged to also indicate that a target object is outside the focusable distance range in ordinary photography by the picture taking optical system, thereby informing a photographer of the need for the changeover from ordinary photography to close-up photography.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects, features and advantages of the invention are readily apparent from the following description of the invention taken in conjunction with the drawings, wher
REFERENCES:
patent: 3723003 (1973-03-01), Vockenhuber
patent: 3836934 (1974-09-01), Suzuki et al.
patent: 4251144 (1981-02-01), Matsuda et al.
Minolta Camera Kabushiki Kaisha
Perkey William B.
LandOfFree
Camera with an automatic focusing device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Camera with an automatic focusing device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Camera with an automatic focusing device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-776040