Automatic exposure control system

Claim 2

A photographic exposure control system for exposing, during a given flash illumination interval, photographic film located at a given film plane, said system comprising a variable lens assembly for directing image carrying rays from a scene along a given exposure path and for focusing such rays on such photographic material, and control means for controlling the instantaneous amount of light rays passing from such scene along such exposure path during an exposure cycle and for defining a related time interval during which such instantaneous amount of light is passed along such exposure path so as to provide an exposure interval and thereby determine the total amount of light passed to such film during such exposure cycle and, in response To focusing of said lens assembly, for determining a unique relationship between said instantaneous defining means and said exposure time interval defining means so as to provide an optimized exposure at selected subject distances, such relationship being varied at an intermediate subject distance so as to provide an exposure interval utilizing almost all of the flash interval and greater than the amount of flash interval utilized at focus settings for subject distances at least slightly less than or slightly greater than such intermediate distance so as to preclude over exposure of subjects at this intermediate distance.

Claim 3

The system of claim 1 for use also under ambient illumination, and wherein said means for defining a related time interval includes means for sensing the brightness of such scene, said brightness sensing being configured for leading said instantaneous light controlling means so as to anticipate the total amount of light passed along such path when said system is operated under ambient conditions, and said relationship determining means includes means for reducing said leading of said light sensitive means so as to reduce such anticipation of such scene brightness at intermediate focus distances and to thereby provide an exposure time interval utilizing a substantial portion of such flash interval.

Claim 4

The system of claim 1 for use also under ambient illumination, and wherein said means for defining a related time interval includes means for sensing the brightness of such scene, and said control means including means for varying said instantaneous light controlling means from a minimum to a maximum value and for simultaneously controlling the response of said brightness sensing means from a minimum to a maximum value which leads said instaneous light controlling means and then to reduced value so as to anticipate the total amount of light passed along such path in ambient operation as said instantaneous light controlling means is driven to its maximum and for then providing a reduced response to said brightness sensing means when said instantaneous light sensing means is maintained at its said maximum.

Claim 5

The system of claim 3 wherein said relationship determining is selectively operable, and additionally including means for rending said relationship determining means operative for flash mode operation.

Claim 6

The system of claim 1 wherein said control means includes a cam mechanism coupled to said focusing lens and operable therewith a first cam surface for near the intermediate subject distances and a second cam surface for further subject distances, selectively operable means for blocking and unblocking said exposure path and for defining a primary aperture for controlling light rays passing along said exposure path and means responsive to scene brightness for actuating said blocking and unblocking means to block said path following the unblocking thereof so as to terminate an exposure cycle, and said aperture defining means and said scene brightness responsive means being coupled to said cam mechanism and controlled thereby so as to provide a first aperture curve and scene brightness response curve for near to intermediate distances and a different curve for intermediate to further distances.

Claim 7

The system of claim 5 wherein said cam mechanism includes a third camm surface corresponding to focusing at far distances, said first cam surface providing only slight increase in said aperture size and said brightness response as said focus setting is varied from near to intermediate distances, said second cam surface providing a relatively large increase in said aperture size and said brightness response as said focus setting is varied from intermediate to further distances, and said third cam surface providing a relatively small increase in said aperture size and said brightness response as said focus setting is varied from said further to far distances.

Claim 8

A photographic exposure control system for exposing, under ambient or flash illuminatin, photogRaphic material located at a given film plane, said system comprising a housing, an opening in said housing defining a maximum main aperture, a variable lens system for directing image carrying rays along a given exposure path from a scene through said housing opening and for focusing such rays on such photographic material, shutter means for blocking and unblocking said exposure path, means responsive to scene light for actuating said shutter means to block said path following the unblocking of said path, said shutter means including a pair of blade members mounted for displacement with respect to each other, each of said blade members having a primary and secondary opening which when displaced into at least partial coincidence with the corresponding opening of the other blade member respectively define a primary aperture for unblocking said exposure path and a secondary aperture for blocking said light responsive means, said primary opening being of larger size than said housing opening and being elongated in the direction of travel of said blade members so as to provide a substantially constant exposure opening at one point in displacement of said blade members while said secondary openings continue to provide an altered secondary aperture such that said secondary aperture may be varied while said main aperture is fully open.

Claim 9

A photographic exposure control system for exposing, under ambient or flash illuminatin, photogRaphic material located at a given film plane, said system comprising a housing, an opening in said housing defining a maximum main aperture, a variable lens system for directing image carrying rays along a given exposure path from a scene through said housing opening and for focusing such rays on such photographic material, shutter means for blocking and unblocking said exposure path, means responsive to scene light for actuating said shutter means to block said path following the unblocking of said path, said shutter means including a pair of blade members mounted for displacement with respect to each other, each of said blade members having a primary and secondary opening which when displaced into at least partial coincidence with the corresponding opening of the other blade member respectively define a primary aperture for unblocking said exposure path and a secondary aperture for blocking said light responsive means, said primary opening being of larger size than said housing opening and being elongated in the direction of travel of said blade members so as to provide a substantially constant exposure opening at one point in displacement of said blade members while said secondary openings continue to provide an altered secondary aperture such that said secondary aperture may be varied while said main aperture is fully open.

Claim 10

A photographic exposure control system for exposing with flash illumination photographic material located at a given film plane, said system comprising a variable lens system for directing image carrying rays along a given exposure path from a scene and focusing such rays on such material, selectively operable shutter means for blocking and unblocking such exposure path, means for actuating said shutter means to unblock said path so as to initiate an exposure cycle, a light sensitive element configured for automatically actuating said shutter means to block said exposure path responsive to the brightness of such scene following initiation of an exposure cycle, said shutter means including means for determining a primary aperture opening of given size within a given range for control of the instantaneous amount of light passed to such film and for determining a secondary aperture opening of given size within a given range for control of the instantaneous amount of scene light emitted to said light sensitive element, follow-focus means responsive to selected focusing of said lens for selecting a given size of said main and said secondary apertures, said follow-focus means including means for determining said apertures over a first range of values for near to intermediate subject distances and a second range of values for intermediate to far subject distances.

Claim 11

A photographic exposure control system for exposing with flash illumination photographic material located at a given film plane, said system comprising a variable lens system for directing image carrying rays along a given exposure path from a scene and focusing such rays on such material, selectively operable shutter means for blocking and unblocking such exposure path, means for actuating said shutter means to unblock said path so as to initiate an exposure cycle, a light sensitive element configured for automatically actuating said shutter means to block said exposure path responsive to the brightness of such scene following initiation of an exposure cycle, said shutter means including means for determining a primary aperture opening of given size within a given range for control of the instantaneous amount of light passed to such film and for determining a secondary aperture opening of given size within a given range for control of the instantaneous amount of scene light emitted to said light sensitive element, follow-focus means responsive to selected focusing of said lens for selecting a given size of said main and said secondary apertures, said follow-focus means including means for determining said apertures over a first range of values for near to intermediate subject distances and a second range of values for intermediate to far subject distances.

Claim 12

A photographic exposure control system for exposing under ambient or flash illumination photographic material located at a given film plane, said system comprising a variable lens arrangement for directing image carrying rays along a given exposure path from a scene and for focusing such rays on such film material, selectively operable shutter means for blocking and unblocking such exposure path, means for actuating said shutter means to unblock said exposure path and thereby initiate an exposure cycle, means responsive to scene brightness for automatically actuating said shutter means to block said path following the initiation of such exposure cycle so as to terminate said exposure cycle and thereby determine an exposure interval, said shutter means including means for determining a main shutter aperture for controlling the instantaneous amount of light passing to such film plane and a secondary shutter aperture for controlling the instantaneous amount of scene light passing to said brightness responsive means, said shutter means including means for opening said secondary aperture at a relatively faster rate than the opening of said main aperture such that said secondary aperture leads said main aperture so as to provide an anticipation of scene brightness for ambient operations and Said shutter means including means for decreasing such lead of such secondary aperture at intermediate aperture sizes so as to provide reduced anticipation of the scene brightness thereat and a sufficiently long exposure time at intermediate subject distances when operated in the flash mode to thereby utilize a large portion of the flash envelope at such distances.

Claim 13

A photographic exposure control system for exposing under ambient or flash illumination photographic material located at a given film plane, said system comprising a variable lens arrangement for directing image carrying rays along a given exposure path from a scene and for focusing such rays on such film material, selectively operable shutter means for blocking and unblocking such exposure path, means for actuating said shutter means to unblock said exposure path and thereby initiate an exposure cycle, means responsive to scene brightness for automatically actuating said shutter means to block said path following the initiation of such exposure cycle so as to terminate said exposure cycle and thereby determine an exposure interval, said shutter means including means for determining a main shutter aperture for controlling the instantaneous amount of light passing to such film plane and a secondary shutter aperture for controlling the instantaneous amount of scene light passing to said brightness responsive means, said shutter means including means for opening said secondary aperture at a relatively faster rate than the opening of said main aperture such that said secondary aperture leads said main aperture so as to provide an anticipation of scene brightness for ambient operations and Said shutter means including means for decreasing such lead of such secondary aperture at intermediate aperture sizes so as to provide reduced anticipation of the scene brightness thereat and a sufficiently long exposure time at intermediate subject distances when operated in the flash mode to thereby utilize a large portion of the flash envelope at such distances.

Claim 14

The system of claim 9 wherein said lead of said secondary aperture over said main aperture is rapidly decreased at said intermediate subject distance settings and then rapidly increased as said shutter means is operated to progressively open said apertures so as to thereby provide suitable lead throughout most the shutter opening curve for ambient operation while providing reduced lead at intermediate subject distances in flash operation.

Claim 15

The system of claim 9 wherein said shutter means includes a pair of displaceable mounted blade members having a first pair of openings for defining said primary aperture and a second pair of openings for defining said secondary aperture, said second openings including elongated, narrow leading portions of substantially uniform width for providing an initial small increase in aperture size with blade displacement and second portions providing an abrupt increase in width for providing a rapid increase in aperture size with further blade displacement.

Claim 16

A photographic exposure control system for exposing, under ambient or flash illumination, photographic film material located at a given film plane, said system comprising a lens for directing light from a scene along a given exposure path to such film material, means for sensing the brightness of such scene, means for unblocking and thereafter blocking said exposure path and said brightness sensing means, means for actuating said unblocking and blocking means to unblock said path to thereby initiate an exposure cycle, and means responsive to said brightness sensing means for actuating said unblocking and blocking means to block said exposure path following the initiation of said exposure cycle to terminate said exposure cycle and thereby define an exposure interval, said unblocking and blocking means including means for controlling the instantaneous amounts of light passed from such scene along said exposure path and to said brightness sensing means from minimum to maximum values during unblocking of said exposure path with the instantaneous amount of light passed to said brightness sensing means in leading relation to that directed along said exposure path so as to provide anticipation of scene brightness, said blocking and unblocking means including means for maintaining the instantaneous amount of light passed from such scene along said exposure path at a maximum value while reducing the instantaneous amount of light passed from such scene to said brightness sensing means from a maximum to a lesser value so as to thereby provide a reduced response of said brightness sensing means.

Claim 17

A photographic exposure control system for exposing, under ambient or flash illumination, photographic film material located at a given film plane, said system comprising a lens for directing light from a scene along a given exposure path to such film material, means for sensing the brightness of such scene, means for unblocking and thereafter blocking said exposure path and said brightness sensing means, means for actuating said unblocking and blocking means to unblock said path to thereby initiate an exposure cycle, and means responsive to said brightness sensing means for actuating said unblocking and blocking means to block said exposure path following the initiation of said exposure cycle to terminate said exposure cycle and thereby define an exposure interval, said unblocking and blocking means including means for controlling the instantaneous amounts of light passed from such scene along said exposure path and to said brightness sensing means from minimum to maximum values during unblocking of said exposure path with the instantaneous amount of light passed to said brightness sensing means in leading relation to that directed along said exposure path so as to provide anticipation of scene brightness, said blocking and unblocking means including means for maintaining the instantaneous amount of light passed from such scene along said exposure path at a maximum value while reducing the instantaneous amount of light passed from such scene to said brightness sensing means from a maximum to a lesser value so as to thereby provide a reduced response of said brightness sensing means.

Claim 18

A photographic exposure control system for exposing, under ambient or flash illumination, photographic material located at a given film plane, said system comprising a housing, an opening in said housing defining a maximum main aperture, a lens system for directing image carrying rays along a given exposure path from a scene through said housing opening and for focusing such rays on such photographic material, means for unblocking and blocking said exposure path, means for actuating said unblocking and blocking means to unblock said exposure path and thereby initiate an exposure cycle, means responsive to scene light for actuating said unblocking and blocking means to block said path following the unblocking thereof so as to terminate said cycle, said unblocking and blocking means including a pair of blade members mounted for displacement with respect to each other, each of said blade members having a primary and secondary opening which when displaced into at least partial coincidence with the corresponding opening of the other blade mEmber respectively define a primary aperture for unblocking said exposure path and a secondary aperture for unblocking said light responsive means, said primary openings of said blade members being elongated in the direction of travel of said blade members and at least of larger size than said housing opening as measured in said direction so as to provide a substantially constant maximum exposure opening at one point in displacement of said blade members while said secondary openings continue to provide an altered secondary aperture such that said secondary aperture may be varied while said main aperture is fully open.

Claim 19

A photographic exposure control system for exposing, under ambient or flash illumination, photographic material located at a given film plane, said system comprising a housing, an opening in said housing defining a maximum main aperture, a lens system for directing image carrying rays along a given exposure path from a scene through said housing opening and for focusing such rays on such photographic material, means for unblocking and blocking said exposure path, means for actuating said unblocking and blocking means to unblock said exposure path and thereby initiate an exposure cycle, means responsive to scene light for actuating said unblocking and blocking means to block said path following the unblocking thereof so as to terminate said cycle, said unblocking and blocking means including a pair of blade members mounted for displacement with respect to each other, each of said blade members having a primary and secondary opening which when displaced into at least partial coincidence with the corresponding opening of the other blade mEmber respectively define a primary aperture for unblocking said exposure path and a secondary aperture for unblocking said light responsive means, said primary openings of said blade members being elongated in the direction of travel of said blade members and at least of larger size than said housing opening as measured in said direction so as to provide a substantially constant maximum exposure opening at one point in displacement of said blade members while said secondary openings continue to provide an altered secondary aperture such that said secondary aperture may be varied while said main aperture is fully open.

Claim 20

The system of claim 13 wherein said secondary openings in said blade members are configured to provide a reduction in the size of said secondary aperture as said blade members are displaced through said one point providing a maximum exposure opening so as to thereby reduce the response of said light responsive means when said maximum exposure opening is achieved.

Claim 21

The system of claim 13 wherein said blade openings are configured to provide, during blade displacement of said corresponding openings into coincidence, a leading relation of said secondary aperture to said primary aperture until said one point in displacement is reached and a reduction in said secondary aperture as said blade members are displaced through said one point so as to reduce the response of said light responsive means when said maximum exposure opening is achieved.

Claim 22

A photographic exposure control system for a camera for exposing photographic film under artificial illumination of given intensity during a given artificial illumination interval, the camera having means for mounting the photographic film at a focal plane, means defining a optical path along which image carrying light rays from a scene are directed to the camera focal plane, and means indicative of subject distance, said system comprising means responsive to the subject distance indicating means for limiting the instantaneous amount of light rays passing from the scene along the optical path during an exposure cycle as a function of subject distance, and means reponsive to scene light for defining a time interval during which the instantaneous amount of light is passed along the optical path so as to define an exposure interval as a function of scene brightness, said light ray limiting means and said exposure time interval defining means being interrelated in a predetermined manner to provide an exposure interval at a predetermined subject distance utilizing a portion of the given illumination interval greater than the portion of the illumination interval utilized by the exposure interval at a subject distance slightly greater than such predetermined distance to preclude overexposure of subjects at this predetermined distance.

Claim 23

A photographic exposure control system for a camera for exposing photographic film under artificial illumination of given intensity during a given artificial illumination interval, the camera having means for mounting the photographic film at a focal plane, means defining a optical path along which image carrying light rays from a scene are directed to the camera focal plane, and means indicative of subject distance, said system comprising means responsive to the subject distance indicating means for limiting the instantaneous amount of light rays passing from the scene along the optical path during an exposure cycle as a function of subject distance, and means reponsive to scene light for defining a time interval during which the instantaneous amount of light is passed along the optical path so as to define an exposure interval as a function of scene brightness, said light ray limiting means and said exposure time interval defining means being interrelated in a predetermined manner to provide an exposure interval at a predetermined subject distance utilizing a portion of the given illumination interval greater than the portion of the illumination interval utilized by the exposure interval at a subject distance slightly greater than such predetermined distance to preclude overexposure of subjects at this predetermined distance.

Claim 24

The system of claim 16 wherein the portion of the illumination interval utilized at said predetermined subject distance is also greater than the portion of the illumination interval utilized at a subject distance slightly less than said predetermined distance.

Claim 25

The system of claim 16 wherein the camera includes a variable lens assembly and means for varying said lens assembly in accordance with subject distance so as to focus scene light rays on the camera focal plane, said limiting means includes means for defining an aperture of variable size located in the optical path, cam means operatively coupled to the lens varying means and having a cam surface displaceable in response to focusing of the lens assembly, and means for coupling said aperture defining means in cam follower relation to said cam surface and for controlling said aperture defining means to select an aperture size in accordance with lens focusing, said cam surface including an offset portion corresponding to said predetermined subject distance so as to select a given aperture size configured for utilizing said greater portion of the illumination interval at said predetermined subject distance for proper exposure.

Claim 26

The system of claim 16 for use under both ambient and artificial illumination wherein said exposure interval defining means includes means for sensing the brightness of the scene, and said limiting means includes means operable upon initiation of an exposure cycle for defining a variable aperture of progressively increasing size located in the optical path and for varying said sensing means in tracking relation to the size of said variable aperture to provide a light sensing response proportional to scene brightness and said aperture size in an ambient illumination mode of operation and means operable in an artificial illumination mode and responsive to the subject distance indicating means for controlling said aperture defining means to select an aperture size as a function of the subject distance indication, and said tracking relation being altered at a given aperture size functionally related to said predetermined subject distance so as to reduce the response of said sensing means at said given aperture size thereby increasing the exposure interval at said prederermined subject distance so as to utilize said greater portion of the illumination interval at said predetermined subject distance in the artificial illumination mode.

Claim 27

The system of claim 19 wherein the camera includes a variable lens assembly and means for varying said lens assembly in accordance with subject distance to focus scene light rays on the camera focal plane, and said limiting means includes cam means operatively coupled to the lens varying means and having a cam surface displaceable inresponse to focusing of said lens assembly, and means for coupling said aperture defining means in cam follower relation to said cam surface and for controlling said aperture defining means to select an aperture size in accordance with lens focusing, and said cam surface having an offset portion therein corresponding to said predetermined subject distance so as to select a given aperture size configured for utilizing said greater portion of the illumination interval at said predetermined subject distance for proper exposure.

Claim 28

A photographic exposure control system for use with a camera for exposing photographic film under ambient illumination or under artificial illumination and responsive in an artificial illumination mode to both scene brightness and subject distance, the camera having means for mounting the photographic film at a focal plane, a lens for directing light from a scene along a given optical path to the film plane, and means for determining subject distance, said system comprising means for sensing the brightness of the scene, means for unblocking and thereafter blocking the given optical path, means for actuating said unblocking and blocking means to unblock the given optical path to thereby initiate an exposure cycle, and means responsive to said brightness sensing means for actuating said unblocking and blocking means to block the given optical path following the initiation of said exposure cycle so as to terminate said exposure cycle and thereby define an exposure interval, said unblocking and blocking means including means for simultaneously limiting the instantaneous amounts of scene light passed along the optical path and to said brightness sensing means from minimum to maximum values during unblocking of the given optical path with the instantaneous amount of scene light passed to said brightness sensing means in leading relation to the amount passed along the given optical path so as to thereby provide anticipation of scene brightness, means operative in the artificial illumination mode and responsive to the subject distance determining means for controlling said blocking and unblocking means so as to provide a limiting of selected value between said minimum and maximum values as a function of subject distance, and said blocking and unblocking means additionally including means for maintaining the limiting of the instantaneous amount of scene light passed along the given opticAl path at its maximum value while decreasing the limiting of the instantaneous amount of scene light passed to said brightness sensing means from a maximum to a lesser value so as to thereby provide a reduced response of said brightness sensing means for ambient mode operation.

Claim 29

A photographic exposure control system for use with a camera for exposing photographic film under ambient illumination or under artificial illumination and responsive in an artificial illumination mode to both scene brightness and subject distance, the camera having means for mounting the photographic film at a focal plane, a lens for directing light from a scene along a given optical path to the film plane, and means for determining subject distance, said system comprising means for sensing the brightness of the scene, means for unblocking and thereafter blocking the given optical path, means for actuating said unblocking and blocking means to unblock the given optical path to thereby initiate an exposure cycle, and means responsive to said brightness sensing means for actuating said unblocking and blocking means to block the given optical path following the initiation of said exposure cycle so as to terminate said exposure cycle and thereby define an exposure interval, said unblocking and blocking means including means for simultaneously limiting the instantaneous amounts of scene light passed along the optical path and to said brightness sensing means from minimum to maximum values during unblocking of the given optical path with the instantaneous amount of scene light passed to said brightness sensing means in leading relation to the amount passed along the given optical path so as to thereby provide anticipation of scene brightness, means operative in the artificial illumination mode and responsive to the subject distance determining means for controlling said blocking and unblocking means so as to provide a limiting of selected value between said minimum and maximum values as a function of subject distance, and said blocking and unblocking means additionally including means for maintaining the limiting of the instantaneous amount of scene light passed along the given opticAl path at its maximum value while decreasing the limiting of the instantaneous amount of scene light passed to said brightness sensing means from a maximum to a lesser value so as to thereby provide a reduced response of said brightness sensing means for ambient mode operation.