Dynamically compensated exposure control system

Claim 2

An exposure control system for photographic apparatus comprising: exposure mechanism means selectively movable in a first direction toward a first terminal position and in a second Direction toward a second terminal position to control light passage through an exposure aperture; spring means normally operative to exert force against said exposure mechanism so as to move said exposure mechanism in said first direction toward said first terminal position, said spring means being actuable to exert force against said exposure mechanism so as to move said exposure mechanism in said second position toward said second terminal position; and means responsive to an electrical energy input to actuate said spring means such that said spring means moves said exposure mechanism in said second direction toward said second terminal position.

Claim 3

The exposure control system of claim 1 wherein said spring means include first spring means biasing said exposure mechanism means to move in said first direction toward said first terminal position; and second spring means biasing said exposure mechanism means to move in said second direction toward said second terminal position and said first spring means being effective when said electrical energy input is removed from said means for actuating said spring means to move said exposure mechanism in said first direction against the bias exerted by said second spring means, the application of said electrical energy input to said means for actuating said spring means being effective to remove the influence of said first spring means from said exposure mechanism means so as to permit said exposure mechanism means movement in said second direction toward said second terminal position by said second spring means bias.

Claim 4

The exposure control system of claim 2 in which said means for actuating said spring means is configured to load said first spring means at an accelerative rate selected to negate the influence thereof upon said exposure mechanism means movement in said second direction toward said second terminal position.

Claim 5

The exposure control system of claim 3 in which said exposure mechanism means is configured to progressively unblock said exposure aperture when moved in said first direction and to progressively block said exposure aperture when moved in said second direction.

Claim 6

An exposure control mechanism for photographic apparatus comprising: exposure mechanism means movable in first and second directions to control light passage through an exposure aperture; tractive eletromagnetic means including an excitation winding and a movable armature, said armature being movable in one direction upon energization of said excitation winding; first spring means biasing said exposure mechanism means to move in said first direction; and second spring means biasing said movable armature in a second direction and being effective when said winding is unenergized to move said exposure mechanism in said second direction against the said bias exerted by said first spring means, the energization of said winding being effective to remove the influence of said second spring means from said first spring means so as to permit said exposure mechanism means movement in said first direction only by said first spring means bias.

Claim 7

An exposure control mechanism for photographic apparatus comprising: exposure mechanism means movable in first and second directions to control light passage through an exposure aperture; tractive eletromagnetic means including an excitation winding and a movable armature, said armature being movable in one direction upon energization of said excitation winding; first spring means biasing said exposure mechanism means to move in said first direction; and second spring means biasing said movable armature in a second direction and being effective when said winding is unenergized to move said exposure mechanism in said second direction against the said bias exerted by said first spring means, the energization of said winding being effective to remove the influence of said second spring means from said first spring means so as to permit said exposure mechanism means movement in said first direction only by said first spring means bias.

Claim 8

The exposure control mechanism of claim 5 in which said tractive electromagnetic means is operative to load said second spring means when said winding is energized.

Claim 9

The exposure control mechanism of claim 6 in which said tractive electromagnetic means is configured to load said second spring means at an accelerative rate selected to negate the influence thereof upon said exposure mechanism means movement in said first direction.

Claim 10

The exposure control mechanism of claim 7 in which said exposure mechanism means is configured to progressively unblock said exposure aperture when moved in said second direction, and to block said light passage when moved in said first direction.

Claim 11

The exposure control mechanism of claim 8 in which said second spring means is connected with said armature for selective loading thereby, and is connected in negatable driving relationship wiTh said exposure mechanism means.

Claim 12

The exposure control mechanism of claim 9 in which said first spring means is connected in driving relationship with said exposure mechanism means.

Claim 13

An exposure control mechanism for photographic apparatus comprising: shutter means movable between first and second positions to control the light permitted to pass through an exposure aperture; tractive electromagnetic means including an excitation winding and a movable armature, said armature being movable in one direction upon excitation of said excitation winding; first spring means biasing said shutter means toward said first position; and second spring means biasing said movable armature in a second direction and also being effective, when said excitation winding is unenergized, to force said shutter means into said second position against the bias provided by said first spring means, the energization of said winding being effective rapidly to remove the influence of said second spring means from said shutter means thereby permitting said first spring means to move said shutter means to said first position, the de-energization of said winding resulting in the return of said shutter means to said second position under the net influence of said first and second spring means.

Claim 14

An exposure control mechanism for photographic apparatus comprising: shutter means movable between first and second positions to control the light permitted to pass through an exposure aperture; tractive electromagnetic means including an excitation winding and a movable armature, said armature being movable in one direction upon excitation of said excitation winding; first spring means biasing said shutter means toward said first position; and second spring means biasing said movable armature in a second direction and also being effective, when said excitation winding is unenergized, to force said shutter means into said second position against the bias provided by said first spring means, the energization of said winding being effective rapidly to remove the influence of said second spring means from said shutter means thereby permitting said first spring means to move said shutter means to said first position, the de-energization of said winding resulting in the return of said shutter means to said second position under the net influence of said first and second spring means.

Claim 15

The exposure control mechanism of claim 11 in which said shutter means is configured to block the passage of said light through said aperture when at said first position, and to permit said light passage when at said second position.

Claim 16

An exposure control system for photographic apparatus comprising: light valve means selectively movable to block and unblock an exposure aperture; spring means having first characteristic force values for biasing said valve means for movement to block said exposure aperture, and having second characteristic force values for biasing said valve means for movement to unblock said exposure aperture; tractive electromagnetic means energizable to drive only said spring means against said second characteristic force value bias, and de-energizable for effecting said valve means movement under said second characteristic force value bias; and control means for selectively energizing and de-energizing said tractive electromagnetic means.

Claim 17

An exposure control system for photographic apparatus comprising: light valve means selectively movable to block and unblock an exposure aperture; spring means having first characteristic force values for biasing said valve means for movement to block said exposure aperture, and having second characteristic force values for biasing said valve means for movement to unblock said exposure aperture; tractive electromagnetic means energizable to drive only said spring means against said second characteristic force value bias, and de-energizable for effecting said valve means movement under said second characteristic force value bias; and control means for selectively energizing and de-energizing said tractive electromagnetic means.

Claim 18

The exposure control system of claim 13 in which said spring means second characteristic force values are higher than said first characteristic force values.

Claim 19

The exposure control system of claim 14 in which said spring means includes means isolating said second force values from said first force values when said tractive electromagnetic means is energized.

Claim 20

The exposure control system of claim 15 in which said spring means includes: first spring means cooperating with said valve means and exhibiting said second characteristic force values; and second spring means cooperating with said valve means and exhibiting said second characteristic force values.

Claim 21

The exposure control system of claim 16 in which said spring means includes means associating said first spring means in driven relationship with said second spring means when said tractive electromagnetic means is de-energized.