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US 4,792,823 AGranted
Camera and camera system
AssigneeMinolta Camera Kabushiki Kaisha
InventorsAkihiko Fujino, Masaaki Nakai, Hiroshi Ootsuka
Life of this patent
Estimating the term…
Abstract
A camera or camera system includes a depth of field preview device for stopping down an aperture of an objective lens mounted on the camera to a predetermined aperture value in response to a manual operation prior to its photographing operation, and an AE lock device for storing a light measuring signal indicative of the brightness of object in response to another manual operation. In the camera or camera system, proper exposure can be obtained even if the depth of field preview device and the AE lock device are intended to be operated together, with compensating and correcting exposure error which would be produced by operation of both devices.
Claims36
A camera system including a camera body and an objective lens for photographing, mountable on the camera body, comprising:
- a preview operating member;
- a release operating member;
- means for starting an exposure operation of the camera system in response to operation of the release operating member;
- means for stopping down an aperture diaphragm of the objective lens to a predetermined aperture value in response to operation of the preview operating member;
- means for discriminating whether the stopping down operation is being performed;
- means for measuring light transmitted through the objective lens to produce a light measuring signal relative to the measured light;
- means for correcting the light measuring signal in accordance with a difference between a light measuring signal measured when the aperture diaphragm is fully opened and a light measuring signal measured when the aperture diaphragm is stopped down by the stopping down means;
- and
- means for controlling the correcting means to operate the correcting means when the discriminating means detects that the stopping down operation is being performed.
6 more elements
A camera system including a camera body and an objective lens for photographing, mountable on the camera body, comprising:
- a preview operating member;
- a release operating member;
- means for starting an exposure operation of the camera system in response to operation of the release operating member;
- means for stopping down an aperture diaphragm of the objective lens to a predetermined aperture value in response to operation of the preview operation member;
- means for discriminating whether the stopping down operation is being performed;
- means for measuring light transmitted through the objective lens to produce a light measuring signal relative to the measured light;
- means for compensating the light measuring signal in accordance with a difference between a light measuring signal measured when a predetermined reference lens is attached to the camera body and a light measuring signal measured when the objective lens for photographing is attached thereto;
- and
- means for controlling the compensating means responsive to the discriminating means.
6 more elements
A camera system including a camera body and an objective lens for photographing, mountable on the camera body, comprising:
- a preview operating member;
- a release operating member;
- means for starting an exposure operation of the camera system in response to operation of the release operating member;
- means for stopping down an aperture diaphragm of the objective lens to a predetermined aperture value in response to operation of the preview operating member;
- means for discrminating whether the stopping down operation is being performed;
- means for producing data relating to the objective lens attached to the camera body;
- means for indicating an aperture value;
- and
- means for correcting the aperture value indicated by the indicated means based on the data produced by the data producing means when the discriminating means detects that the stopping down operation is being performed.
6 more elements
A camera system including a camera body and an objective lens for photographing, mountable on the camera body, comprising:
- a preview operating member;
- an AE lock operating member;
- means for stopping down an aperture diaphragm of the objective lens to a predetermined aperture value in response to operation of the preview operating member;
- means for discriminating whether the stopping down operation is being performed;
- means for producing data relating to the objective lens attached to the camera body;
- means for measuring light transmitted through the objective lens to produce a light measuring signal relative to the measured light;
- means for calculating proper exposure time in accordance with the light measuring signal;
- means for storing the light measuring signal in response to operation of the AE lock operating member;
- means for storing the data when the light measuring signal storing means stores the light measuring signal;
- and
- means for correcting the proper exposure time calculated by the calculating means in accordance with a difference between the data stored in the data storing means and data produced by the data producing means, when the discriminating means detects that the stopping down operation is being performed.
8 more elements
A camera system including a camera body and an objective lens, comprising:
- a preview operating member;
- an AE lock operating member;
- means for stopping down an aperture diaphragm of the objective lens to a predetermined aperture value in accordance with operation of the preview operating member;
- first means for discriminating whether the stopping down operation is being performed;
- means for measuring light transmitted through the objective lens to produce a light measuring signal relative to the measured light;
- means for storing the light measuring signal in response to operation of the AE lock operating member;
- second means for discriminating whether the storing means is operated or not;
- and
- means for controlling the storing means to store a light measuring signal measured in the condition in which the aperture diaphragm is stopped down by the stopping down means, when the first discriminating means detects that the stopping down operation is performed while the storing means has been discriminated to be operated by the second discriminating means.
6 more elements
A camera system including a camera body and an objective lens, comprising:
- a preview operating member;
- an AE lock operating member;
- means for stopping down an aperture diaphragm of the objective lens to a predetermined aperture value in accordance with operation of the preview operating member;
- means for discriminating whether the stopping down operation is being performed;
- means for measuring light transmitted through the objective lens to produce a light measuring signal relative to the measured light;
- means for storing the light measuring signal in response to operation of the AE lock operating member;
- and
- means for controlling the storing means to cancel the light measuring signal stored in the storing means when the discriminating means detects that the stopping down operation is cancelled after the storing means was once operated in the condition in which the stopping means has been operated.
5 more elements
A camera system including a camera body and an objective lens, comprising:
- a preview operating member;
- an AE lock operating member;
- means for stopping down an aperture diaphragm of the objective lens to a predetermined aperture value in accordance with operation of the preview operating member;
- means for measuring light transmitted through the objective lens to produce a light measuring signal relative to the measured light;
- means for storing the light measuring signal in response to operation of the AE lock operating member;
- means for discriminating whether the storing means is operated or not;
- and
- means for controlling the stopping down means to interrupt the operation of the stopping down means when the discriminating means detects that the storing means is operated.
5 more elements
A camera system including a camera body and an objective lens, comprising:
- a preview operating member;
- means for stopping down an aperture diaphragm of the objective lens to a predetermined aperture value in accordance with operation of the preview operating member;
- means for discriminating whether the stopping down operation is being performed;
- means for discriminating whether an electric power battery is attached to the camera body or not;
- and
- means for indicating a display when the electric power battery is discriminated to be attached to the camera body after the electric power battery has been detached from the camera body in a condition in which the discriminating means detects that the stopping down operation is being performed.
3 more elements
Dependencies are inferred from the claim text.