Exposure parameter information generating circuit in a single lens reflex camera
First Claim
1. In a single lens reflex camera whose photographing lens is interchangeable, said photographing lens having a first signal member for mechanically putting out the information of an exposure parameter Avo -Av (Avo is an APEX symbol representing an aperture value when the diaphragm of said photographing lens forms a maximum aperture and Av is an APEX symbol representing a present aperture value) and a second signal member for mechanically putting out the information of an exposure parameter Avo, said camera being usable in combination with an electronic flash unit and having a third signal member for mechanically putting out the information of a preset exposure parameter Sv (this is an APEX symbol representing the ASA speed value), an exposure time operation circuit for metering the object light passed through the maximum aperture of the diaphragm of said photographing lens and operating a proper exposure time, and a circuit for generating exposure parameter information, said exposure parameter information generating circuit comprising:
- (a) first converter means for converting the mechanical outputs of said first and third signal members into electrical output information Sv +Avo -Av ;
(b) second converter means for converting the mechanical output of said second signal member into electrical output information Avo ;
(c) an adder circuit for adding the electrical outputs of said first and second converter means and electrically putting out Sv -Av information;
(d) a first output terminal for applying the output of said first converter means to said exposure time operation circuit; and
(e) a second output terminal for applying the output of said adder circuit to said electronic flash unit.
1 Assignment
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Accused Products
Abstract
In a single lens reflex camera having an interchangeable photographing lens having a first and a second signal member, the camera being usable in combination with an electronic flash unit and having a third signal member, there is provided an exposure parameter information generating circuit which comprises first converter means for converting the mechanical outputs of the first and third signal members into electrical output information, second converter means for converting the mechanical output of the second signal member into electrical output information, an adder circuit for adding the electrical outputs of the first and second converter means and putting out electrical information, a first output terminal for applying the output of the first converter means to an exposure time operation circuit, and a second output terminal for applying the output of the adder circuit to the electronic flash unit.
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Citations
7 Claims
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1. In a single lens reflex camera whose photographing lens is interchangeable, said photographing lens having a first signal member for mechanically putting out the information of an exposure parameter Avo -Av (Avo is an APEX symbol representing an aperture value when the diaphragm of said photographing lens forms a maximum aperture and Av is an APEX symbol representing a present aperture value) and a second signal member for mechanically putting out the information of an exposure parameter Avo, said camera being usable in combination with an electronic flash unit and having a third signal member for mechanically putting out the information of a preset exposure parameter Sv (this is an APEX symbol representing the ASA speed value), an exposure time operation circuit for metering the object light passed through the maximum aperture of the diaphragm of said photographing lens and operating a proper exposure time, and a circuit for generating exposure parameter information, said exposure parameter information generating circuit comprising:
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(a) first converter means for converting the mechanical outputs of said first and third signal members into electrical output information Sv +Avo -Av ; (b) second converter means for converting the mechanical output of said second signal member into electrical output information Avo ; (c) an adder circuit for adding the electrical outputs of said first and second converter means and electrically putting out Sv -Av information; (d) a first output terminal for applying the output of said first converter means to said exposure time operation circuit; and (e) a second output terminal for applying the output of said adder circuit to said electronic flash unit. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification