Photography – Exposure control circuit
Reexamination Certificate
1999-03-16
2001-04-03
Perkey, W. B. (Department: 2851)
Photography
Exposure control circuit
Reexamination Certificate
active
06212336
ABSTRACT:
This application is based on application No. H10-069754 filed in Japan, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present Invention relates to a multiple exposure camera, and more specifically, to a multiple exposure camera performing a plurality of times of exposures on the same film surface in one release operation.
2. Description of the Prior Art
In conventional photographing, out-of-focus images become blurred. This is undesirable because the edge of the blurred image is enhanced, for example, in the case of a monotonous subject such as a light source. When the degree of blur is substantially uniform in the entire blurred image, a natural and beautiful blurred image is obtained. Means for obtaining such ideal pictures or improving the appearance of pictures include one that uses a so-called apodization effect in which the quantity of the light emanating from the subject and passing through a peripheral portion of the lens is made smaller than that of the light passing through the central portion. This has already been commercialized as a camera.
An arrangement has been disclosed for obtaining pictures where two subjects are in focus by setting a shutter speed, an aperture value, a focal length and in-focus lens driving for a first subject, setting a shutter speed, an aperture value, a focal length and in-focus lens driving for a second subject at a longer distance than the first subject, and performing multiple exposure as described in Japanese Laid-open Patent Application No. H4-215633.
Moreover, the present applicant has disclosed an arrangement in which for a first subject and a second subject at different distances in the photographic image plane, an aperture value where at least one of the subjects is situated outside the depth of field and an aperture value where both are situated within the depth of field are decided and multiple exposure is performed at each of the aperture values as described in Japanese Laid-open Patent Application No. H6-160933.
However, in the conventional product using the apodization effect, the aperture diameter of the diaphragm varies at a constant speed, so that it is impossible to arbitrarily set the apodization effect. Moreover, in the arrangement as described in Japanese Laid-open Patent Application No. H4-215633, an object thereof is to obtain pictures in which subjects at different distances are in focus, which is different from the object of the present invention, i.e. to obtain natural and beautiful blurred images. Moreover, the arrangement as described in Japanese Laid-open Patent Application No. H6-160933 merely provides pictures in which a single blurred image is superimposed outside an in-focus image.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a multiple exposure camera in which natural and beautiful blurred images are obtained by using the so-called apodization effect in a camera of a normal arrangement in which a diaphragm mechanism is set at a predetermined aperture value before exposure is started, a shutter mechanism operates with the aperture diameter being fixed and the aperture value does not vary during exposure.
To achieve the above-mentioned object, according to the present invention, a multiple exposure camera performing a plurality of times of exposures on the same film surface in one release operation is provided with exposure means for performing an exposure operation by controlling a diaphragm and a shutter and control means for performing the exposure operation by the exposure means at a predetermined aperture value and a predetermined shutter speed in each of the plurality of times of exposures.
The aperture value includes an aperture value set by the user, an open aperture value, a value in minimum aperture state (hereinafter, referred to as minimum aperture value) and an aperture value decided based on a maximum shutter speed and a predetermined exposure amount.
The aperture value in each exposure is set so as to have a predetermined ratio to an immediately preceding aperture value. Or, the aperture value in each exposure is set so as to have a predetermined difference from the immediately preceding aperture value.
The shutter speed is controlled so that the exposure amount in each exposure is the same. Or, the shutter speed is controlled so that the exposure amount increases as the aperture value in each exposure decreases. Or, the shutter speed is controlled so that the exposure amount decreases as the aperture value in each exposure decreases.
The aperture value in each exposure is set with reference to the open aperture value or the minimum aperture value. The shutter speed in each exposure is set with reference to the maximum shutter speed.
The plurality of times of exposures are performed in the order of decreasing exposure amount. The number of the plurality of times of exposures is at least three.
REFERENCES:
patent: 5253007 (1993-10-01), Tokura et al.
patent: 4-215633 (1992-08-01), None
patent: 6-160933 (1994-06-01), None
Minato Shoichi
Ohmori Shigeto
Suzuki Tatsuya
Tanaka Yoshiharu
Tanii Junichi
Minolta Co. , Ltd.
Morrison & Foerster / LLP
Perkey W. B.
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