Exposure control system

Claim 2

An exposure control system for photographic apparatus comprising: aperture-determining means adjustable over a range of exposure values; shutter means for controlling the exposure interval during which scene light is permitted to pass through the aperture determined by said aperture-determining means; electronic control means operable in an aperture mode and a shutter-timing mode, said electronic control means when operating in its aperture mode being responsive to scene brightness for adjusting said aperture determining means automatically to establish for each selected level of scene brightness within a predetermined brightness range a different effective aperture area with a controlled relationship by which the product of brightness and the effective aperture area increases with increasing selected brightness levels, said electronic control means when operating in its shuttertiming mode being responsive to the value of At least one selected electrical circuit parameter to control said shutter means in a manner determinative of exposure interval; means for automatically adjusting said electrical circuit parameter of said electronic control means as a function of scene brightness and also as a function of the selected aperture area to establish for each level of scene brightness and its corresponding effective aperture area a different and unique value of said electrical circuit parameter; and sequencing means operable upon initiation of an exposure cycle first to cause said electronic control means to operate in its aperture mode to provide automatic adjustment of effective aperture area as a function of scene brightness and thereafter to cause said electronic control means to operate in its shutter-timing mode to control exposure interval in response to the adjusted value of said electrical circuit parameter such that for each different level of scene brightness and its corresponding effective aperture area, there is established a different and unique exposure interval corresponding thereto.

Claim 3

The exposure control system of claim 1 wherein said electronic control means includes function-generating means operable during said aperture mode for influencing said aperture-defining means adjustment in accordance with said controlled relationship.

Claim 4

An exposure control system as set forth in claim 2 in which said function generating means include means for generating an electrical signal which varies as a function of time.

Claim 5

An exposure control system as set forth in claim 3 in which the time-varying characteristic of said electrical signal is substantially simulative of the time-dependent-dynamic characteristics of said aperture defining means adjustment.

Claim 6

An exposure control system as set forth in claim 3 wherein said sequencing means includes means responsive to the attainment by said time-varying electrical signal of a preselected condition for causing said electrical control means to operate in its shutter-timing mode.

Claim 7

An exposure control system as set forth in claim 5 including flash mode setting means actuable as a function of a photographic parameter to set a preselected maximum aperture area for flash operation thereby to limit the range of adjustment of said automatically operable aperture-defining adjustment means to said maximum aperture area.

Claim 8

An exposure control system for photographic apparatus comprising: aperture-determining means adjustable over a range of exposure values; means responsive to scene brightness for adjusting said aperture-determining means automatically over a preselected scene brightness range to establish for each selected level of scene brightness within said brightness range a preselected different aperture area with a controlled relationship in which the product of brightness and the effective aperture area increases with increasing selected brightness levels; shutter means for controlling the exposure interval during which scene light is permitted to pass through the aperture determined by said aperture-determining means; electronic control means for controlling said shutter means responsive to the value of at least one selected electrical circuit parameter in a manner determinative of exposure interval; means for automatically adjusting said electrical circuit parameter as a function of scene brightness over said preselected brightness range and also as a function of the controlled aperture area corresponding thereto to establish for each selected level of scene brightness and its corresponding controlled aperture area a different and unique value of said electrical circuit parameter; and sequencing means operable upon initiation of an exposure cycle first to cause said aperture determining means to provide automatic adjustment of aperture area as a function both of scene brightness and of the corresponding controlled aperture area and thereafter operable to activate said control means to cOntrol exposure interval responsive to the adjusted value of said electrical circuit parameter to establish, over said brightness range, for each different level of scene brightness and its corresponding controlled aperture area, a different and unique exposure interval corresponding thereto.

Claim 9

An exposure control system for photographic apparatus comprising: aperture-determining means adjustable over a range of exposure values; means responsive to scene brightness for adjusting said aperture-determining means automatically over a preselected scene brightness range to establish for each selected level of scene brightness within said brightness range a preselected different aperture area with a controlled relationship in which the product of brightness and the effective aperture area increases with increasing selected brightness levels; shutter means for controlling the exposure interval during which scene light is permitted to pass through the aperture determined by said aperture-determining means; electronic control means for controlling said shutter means responsive to the value of at least one selected electrical circuit parameter in a manner determinative of exposure interval; means for automatically adjusting said electrical circuit parameter as a function of scene brightness over said preselected brightness range and also as a function of the controlled aperture area corresponding thereto to establish for each selected level of scene brightness and its corresponding controlled aperture area a different and unique value of said electrical circuit parameter; and sequencing means operable upon initiation of an exposure cycle first to cause said aperture determining means to provide automatic adjustment of aperture area as a function both of scene brightness and of the corresponding controlled aperture area and thereafter operable to activate said control means to cOntrol exposure interval responsive to the adjusted value of said electrical circuit parameter to establish, over said brightness range, for each different level of scene brightness and its corresponding controlled aperture area, a different and unique exposure interval corresponding thereto.

Claim 10

An exposure control system as set forth in claim 7 in which means responsive to scene brightness for adjusting said aperture-determining means includes function generating means for generating an electrical signal which varies as a function of time.

Claim 11

An exposure control system as set forth in claim 8 in which the time-varying characteristic of said electrical signal is substantially simulative of the time-dependent-dynamic characteristics of said aperture-defining aperture means.

Claim 12

An exposure control system for photographic apparatus comprising: aperture-defining means having at least one element movable between terminal positions defining minimum and maximum exposure apertures; drive means having a predetermined dynamic characteristic for moving said element from one of said terminal positions to another at a reproducible rate; means having a predetermined dynamic response to actuation for halting the movement of said element at selected intermediate aperture-defining positions; light-sensitive circuit means responsive to the aperture defined by the said element and to the light level of a scene for generating an output signal; summing means for combining said output signal with an adjusting signal over a period of time corresponding with said element movement to interrelate said drive means dynamic characteristic, said halting means dynamic response and said scene light in accordance with a predetermined program; voltage-sensitive circuit means operative in response to said combined light-sensitive circuit means output signal and said adjusting signal for actuating said halting means, whereby said aperture-defining means element is halted at a position defining an exposure aperture in accordance with said predetermined exposure program; and shutter means responsive to the aperture defined by said element and to said scene light for regulating the interval of an exposure through said aperture in accordance with said predetermined exposure program.

Claim 13

An exposure control system for photographic apparatus comprising: aperture-defining means having at least one element movable between terminal positions defining minimum and maximum exposure apertures; drive means having a predetermined dynamic characteristic for moving said element from one of said terminal positions to another at a reproducible rate; means having a predetermined dynamic response to actuation for halting the movement of said element at selected intermediate aperture-defining positions; light-sensitive circuit means responsive to the aperture defined by the said element and to the light level of a scene for generating an output signal; summing means for combining said output signal with an adjusting signal over a period of time corresponding with said element movement to interrelate said drive means dynamic characteristic, said halting means dynamic response and said scene light in accordance with a predetermined program; voltage-sensitive circuit means operative in response to said combined light-sensitive circuit means output signal and said adjusting signal for actuating said halting means, whereby said aperture-defining means element is halted at a position defining an exposure aperture in accordance with said predetermined exposure program; and shutter means responsive to the aperture defined by said element and to said scene light for regulating the interval of an exposure through said aperture in accordance with said predetermined exposure program.

Claim 14

The exposure control system of claim 10 in which said summing means includes timing circuit means for generating said predetermined adjusting signal.

Claim 15

The exposure control system of claim 10 in which: said summing means includes means for generating said adjusting signal; and said generating means is operative to derive said adjusting signal as a progressively varying voltage.

Claim 16

The exposure control system of claim 12 in which said summing means includes means for initiating the actuation of said generating means simultaneously with the initiation of said movement of said aperture-defining means element.

Claim 17

The exposure control system of claim 10 in which said summing means comprises: capacitor means for deriving said adjusting signal as a varying voltage; and means for selectively charging said capacitor means over a time interval determined in correspondence with the movement of said aperture means element.

Claim 18

The exposure control system of claim 10 in which said summing means comprises: capacitor means coupled with said voltage-sensitive circuit means for forming a variable voltage; and means for charging said capacitor means at a select rate over an interval substantially coincident with the said movement of said aperture-defining means element so as to derive said adjusting signal as said variable voltage.

Claim 19

An exposure control system for photographic apparatus comprising: aperture-defining means having at least one element movable between terminal positions defining minimum and maximum exposure apertures; drive means for urging said element to move at a reproducible rate from one terminal position to another; brake means having a predetermined dynamic response for halting the movement of said element at select intermediate aperture-defining positions; light-sensitive circuit means oriented with respect to a scene for generating a sensing output signal representative of the light levels thereof; means for regulating said light-sensitive circuit means synchronously and in correspondence with the aperture defined by said element; summing means, including capacitor means selectively chargeable in correspondence with the said movement of said aperture-defining means element and with respect to said brake means dynamic response, for generating an adjusting signal and for combining said adjusting signal and said regulated light-sensitive circuit output signal in accordance with select photographic program criteria; trigger means operable in response to said signal combination reaching a predetermined threshold voltage for actuating said brake means to selectively halt said element; and shutter means responsive to the aperture defined by said element and to said scene light level for regulating the interval of an exposure through said aperture.

Claim 20

An exposure control system for photographic apparatus comprising: aperture-defining means having at least one element movable between terminal positions defining minimum and maximum exposure apertures; drive means for urging said element to move at a reproducible rate from one terminal position to another; brake means having a predetermined dynamic response for halting the movement of said element at select intermediate aperture-defining positions; light-sensitive circuit means oriented with respect to a scene for generating a sensing output signal representative of the light levels thereof; means for regulating said light-sensitive circuit means synchronously and in correspondence with the aperture defined by said element; summing means, including capacitor means selectively chargeable in correspondence with the said movement of said aperture-defining means element and with respect to said brake means dynamic response, for generating an adjusting signal and for combining said adjusting signal and said regulated light-sensitive circuit output signal in accordance with select photographic program criteria; trigger means operable in response to said signal combination reaching a predetermined threshold voltage for actuating said brake means to selectively halt said element; and shutter means responsive to the aperture defined by said element and to said scene light level for regulating the interval of an exposure through said aperture.

Claim 21

The exposure control system of claim 16 in which: said light-sensitive circuit includes at least one photosensitive element arranged to receive light from said scene; and said regulating means comprises means for attenuating said scene light received by said photosensitive element synchronously and in correspondence with the movement of said aperture-defining means element.

Claim 22

The exposure control system of claim 17 including means for actuating said shutter means in response to the actuation of said brake means by said trigger means.

Claim 23

The exposure control system of claim 17 wherein said summing means signal combination and said trigger means predetermined threshold voltage are selected such that over a given range of light level values said aperture-defining element defines apertures having an aperture area to light value relationship of less than 1:1.

Claim 24

The exposure control system of claim 17 wherein said aperture-defining means is operative to define continuously variable apertures between said terminal positions.

Claim 25

The exposure control system of claim 17 wherein said aperture-defining means comprises a pair of opaque blades configured and arranged to mutually and synchronously coact to define continuously variable apertures when moved between said terminal positions.

Claim 26

The exposure control system of claim 21 wherein said scene light-attenuating means is formed as an elongate opening disposed within one said opaque blade.

Claim 27

An exposure control system for photographic apparatus comprising: aperture-determining means having at least one element movable between terminal positions for determining a range of effective apertures; shutter means for controlling the exposure interval during which scene light is permitted to pass through the aperture determined by said aperture-determining means; drive means for urging said element to move with a time-dependent dynamic characteristic between said terminal positions; arresting means for selectively halting the movement of said element in response to an aperture mode control signal; function-generating means operable for generating a time-varying electrical signal functionally related to said drive means dynamic characteristic; light-sensitive circuit means operable in an aperture mode and a shutter-timing mode, said light-sensitive circuit means when operating in its aperture mode being automatically responsive to scene brightness, the varying electrical signal of said function-generating means and the aperture determined by said movable element, for actuating said arresting means to halt said movable element of said aperture-determining means to establish for each selected level of scene brightness within a predetermined brightness range a different effective aperture area with a controlled relationship by which the product of brightness and the effective aperture area increases with increasing selected brightness levels; said light-sensitive circuit means when operating in said shutter-timing mode being responsive to scene brightness and also to said selected aperture area for controlling said shutter means in a manner determinative of exposure interval; and sequencing means operable upon initiation of an exposure cycle first to cause said light-sensitive circuit means to operate in its aperture mode to provide automatic adjustment of effective aperture area as a function of scene brightness and thereafter to cause said light-sensitive circuit means to operate in its shutter-timing mode to control exposure interval such that for each different level of scene brightness and its corresponding effective aperture area, there is established a different and unique exposure interval corresponding thereto.

Claim 28

An exposure control system for photographic apparatus comprising: aperture-determining means having at least one element movable between terminal positions for determining a range of effective apertures; shutter means for controlling the exposure interval during which scene light is permitted to pass through the aperture determined by said aperture-determining means; drive means for urging said element to move with a time-dependent dynamic characteristic between said terminal positions; arresting means for selectively halting the movement of said element in response to an aperture mode control signal; function-generating means operable for generating a time-varying electrical signal functionally related to said drive means dynamic characteristic; light-sensitive circuit means operable in an aperture mode and a shutter-timing mode, said light-sensitive circuit means when operating in its aperture mode being automatically responsive to scene brightness, the varying electrical signal of said function-generating means and the aperture determined by said movable element, for actuating said arresting means to halt said movable element of said aperture-determining means to establish for each selected level of scene brightness within a predetermined brightness range a different effective aperture area with a controlled relationship by which the product of brightness and the effective aperture area increases with increasing selected brightness levels; said light-sensitive circuit means when operating in said shutter-timing mode being responsive to scene brightness and also to said selected aperture area for controlling said shutter means in a manner determinative of exposure interval; and sequencing means operable upon initiation of an exposure cycle first to cause said light-sensitive circuit means to operate in its aperture mode to provide automatic adjustment of effective aperture area as a function of scene brightness and thereafter to cause said light-sensitive circuit means to operate in its shutter-timing mode to control exposure interval such that for each different level of scene brightness and its corresponding effective aperture area, there is established a different and unique exposure interval corresponding thereto.

Claim 29

The exposure control system of claim 23 wherein said sequencing means includes means responsive to the attainment by said function-generating means time-varying electrical signal of a preselected condition for causing said light-sensitive circuit means to operate in its shutter-timing mode.

Claim 30

The exposure control system of claim 23 in which said function-generating means comprises: capacitor means for deriving said time-varying electrical signal as a varying voltage; and means for selectively charging said capacitor means substantially simultaneously with the commencement of said movement of said aperture defining means element.

Claim 31

The exposure control system of claim 23 including means for activating said function-generating means upon initiation of an exposure cycle and substantially simultaneously with the commencement of said movement of said element.

Claim 32

The exposure control system of claim 26 wherein said arresting means is selected having a consistent and reproducable dynamic response to actuation by said light-sensitive circuit means.

Claim 33

The exposure control system of claim 27 wherein said light-sensitive circuit means includes trigger means operable to actuate said arresting means in response to said light-sensitive circuit means achieving a first preselected condition when in said aperture mode, and operative to regulate said shutter means in response to said light-sensitive circuit means achieving a second preselected condition when in said shutter-timing mode.

Claim 34

The exposure control system of claim 28 in which said light-sensitive circuit means includes at least one photosensitive element arranged to receive scene light; and said system includes means for attenuating said scene light received by said photosensitive element synchronously and in correspondence with the movement of said aperture-defining means element.

Claim 35

The exposure control system of claim 28 wherein said sequencing means is operative to actuate said shutter means in response to the actuation of said arresting means by said trigger means.

Claim 36

The exposure control system of claim 28 wherein said function-generating means time varying electrical signal, said trigger means first preselected condition, said drive means dynamic characteristic and said arresting means dynamic response are selected such that over said predetermined brightness range said aperture-determining means element determines apertures having an effective aperture area to light value relationship of less than 1:1.

Claim 37

The exposure control system of claim 28 wherein said aperture-determining means element is operative to define continuously variable apertures between said terminal positions.

Claim 38

The exposure control system of claim 29 wherein said aperture-determining means comprises a pair of opaque blades configured and arranged to mutually and synchronously coact to define continuously variable apertures when moved between said terminal positions.

Claim 39

The exposure control system of claim 33 wherein said scene light-attenuating means is formed as an Elongate opening disposed within at least one said opaque blade.

Claim 40

An exposure control system for photographic apparatus comprising: aperture-determining means including at least one element movable from initial to terminal positions to define a range of exposure aperture values in accordance with a predetermined dynamic adjustment characteristic; shutter means for controlling the exposure interval during which scene light is permitted to pass through the aperture determined by said aperture determining means; function-generating means for generating a time-varying electrical signal functionally related to said dynamic adjustment characteristic of said aperture determining means, said signal reaching a preselected condition at least when said movable element reaches said terminal position; circuit means operable in an aperture mode and a shutter-timing mode, said circuit means, when operating in its aperture mode being responsive to scene brightness and the varying electrical signal of said function generating means for adjusting said aperture-determining means automatically, said circuit means, when operating in its shutter-timing mode, being responsive to scene brightness and also to said selected aperture area for controlling said shutter means in a manner determinative of exposure interval; and sequencing means operable upon initiation of an exposure cycle first to cause said circuit means to operate in its aperture mode to provide automatic adjustment of effective aperture area as a function of scene brightness and thereafter to cause said circuit means to operate in its shutter-timing mode at least in response to the attainment by said time-varying electrical signal of said preselected condition.

Claim 41

An exposure control system for photographic apparatus comprising: aperture-determining means including at least one element movable from initial to terminal positions to define a range of exposure aperture values in accordance with a predetermined dynamic adjustment characteristic; shutter means for controlling the exposure interval during which scene light is permitted to pass through the aperture determined by said aperture determining means; function-generating means for generating a time-varying electrical signal functionally related to said dynamic adjustment characteristic of said aperture determining means, said signal reaching a preselected condition at least when said movable element reaches said terminal position; circuit means operable in an aperture mode and a shutter-timing mode, said circuit means, when operating in its aperture mode being responsive to scene brightness and the varying electrical signal of said function generating means for adjusting said aperture-determining means automatically, said circuit means, when operating in its shutter-timing mode, being responsive to scene brightness and also to said selected aperture area for controlling said shutter means in a manner determinative of exposure interval; and sequencing means operable upon initiation of an exposure cycle first to cause said circuit means to operate in its aperture mode to provide automatic adjustment of effective aperture area as a function of scene brightness and thereafter to cause said circuit means to operate in its shutter-timing mode at least in response to the attainment by said time-varying electrical signal of said preselected condition.

Claim 42

The exposure control system of claim 35 wherein said circuit means includes trigger means operable to actuate said sequencing means to cause said circuit means to operate in its shutter-timing mode in response to the receipt of an electrical signal of said preselected condition.

Claim 43

An exposure control system for photographic apparatus comprising: aperture-determining means variable over a range of exposure values in accordance with a predetermined dynamic adjustment characteristic; shutter means for controlling the exposure interval during which scene light is permitted to pass through the aperture determined by said aperture-determining means; function-generating means for generating a time-varying electrical signal functionally related to said dynamic adjustment characteristic of said aperture-determining means; light-sensitive circuit means operable in an aperture mode and a shutter-timing mode, said light-sensitive circuit means, when operating in its aperture mode being responsive to scene brightness and the varying electrical signal of said function generating means for adjusting said aperture-determining means automatically, said light-sensitive circuit means, when operating in its shutter-timing mode, being responsive to scene brightness and also to said selected aperture area for controlling said shutter means in a manner determinative of exposure interval; sequencing means operable upon initiation of an exposure cycle first to cause said light-sensitive circuit means to operate in its aperture mode to provide automatic adjustment of effective aperture areas as a function of scene brightness and thereafter to cause said light-sensitive circuit means to operate in its shutter timing mode at least in response to the attainment by said time varying electrical signal of a preselected condition; and flash mode setting means actuable as a function of a photographic parameter to set a preselected maximum aperture area for flash operation thereby to limit said variation of said aperture-determining means over said range of exposure values to a maximum aperture area.

Claim 44

An exposure control system for photographic apparatus comprising: aperture-determining means variable over a range of exposure values in accordance with a predetermined dynamic adjustment characteristic; shutter means for controlling the exposure interval during which scene light is permitted to pass through the aperture determined by said aperture-determining means; function-generating means for generating a time-varying electrical signal functionally related to said dynamic adjustment characteristic of said aperture-determining means; light-sensitive circuit means operable in an aperture mode and a shutter-timing mode, said light-sensitive circuit means, when operating in its aperture mode being responsive to scene brightness and the varying electrical signal of said function generating means for adjusting said aperture-determining means automatically, said light-sensitive circuit means, when operating in its shutter-timing mode, being responsive to scene brightness and also to said selected aperture area for controlling said shutter means in a manner determinative of exposure interval; sequencing means operable upon initiation of an exposure cycle first to cause said light-sensitive circuit means to operate in its aperture mode to provide automatic adjustment of effective aperture areas as a function of scene brightness and thereafter to cause said light-sensitive circuit means to operate in its shutter timing mode at least in response to the attainment by said time varying electrical signal of a preselected condition; and flash mode setting means actuable as a function of a photographic parameter to set a preselected maximum aperture area for flash operation thereby to limit said variation of said aperture-determining means over said range of exposure values to a maximum aperture area.

Claim 45

The exposure control system of claim 37 in which: said aperture-determining means includes at least one elemenT movable from initial to terminal positions between which said range of exposure values is determined; and the generation time for said varying electrical signal of said function-generating means is selected for deriving said preselected condition in correspondence with the time required for said element to move from said initial to said terminal position.

Claim 46

An exposure control system for photographic apparatus comprising: aperture-defining means having at least one element movable between terminal positions defining minimum and maximum exposure apertures; drive means for urging said element to move at a reproducible rate from one said terminal position to another; brake means for halting the movement of said element at select intermediate aperture-defining positions; light-sensitive circuit means oriented with respect to a scene for generating a sensing output voltage signal representative of the light levels thereof; means for regulating said light-sensitive circuit means synchronously and in correspondence with the aperture defined by said element so that said output signal is responsive to said aperture; summing means for generating an adjusting voltage signal having a predetermined value following a select generation time, and for combining said adjusting voltage signal and said regulated light-sensitive circuit output voltage signal; trigger means operative in response to said voltage signal combination reaching a value equal to said adjusting signal predetermined value for actuating said brake means to selectively halt said element; shutter means for regulating the interval of an exposure through said aperture; and means for actuating said shutter means in response to the actuation of said trigger means by at least said adjusting voltage signal.

Claim 47

An exposure control system for photographic apparatus comprising: aperture-defining means having at least one element movable between terminal positions defining minimum and maximum exposure apertures; drive means for urging said element to move at a reproducible rate from one said terminal position to another; brake means for halting the movement of said element at select intermediate aperture-defining positions; light-sensitive circuit means oriented with respect to a scene for generating a sensing output voltage signal representative of the light levels thereof; means for regulating said light-sensitive circuit means synchronously and in correspondence with the aperture defined by said element so that said output signal is responsive to said aperture; summing means for generating an adjusting voltage signal having a predetermined value following a select generation time, and for combining said adjusting voltage signal and said regulated light-sensitive circuit output voltage signal; trigger means operative in response to said voltage signal combination reaching a value equal to said adjusting signal predetermined value for actuating said brake means to selectively halt said element; shutter means for regulating the interval of an exposure through said aperture; and means for actuating said shutter means in response to the actuation of said trigger means by at least said adjusting voltage signal.

Claim 48

The exposure control system of claim 39 in which said summing means adjusting voltage signal generation time is selected for deriving said predetermined voltage value in correspondence with the time required for said moving of said aperture-defining element from one said terminal position to another.

Claim 49

The exposure control system of claim 39 including follow-focus means operative to selectively preempt the function of said brake means for limiting said movement of said aperture-defining means element in correspondence with the inverse square law of light energy propagation.

Claim 50

The exposure control system of claim 39 in which said summing means adjusting voltage signal generation time is selected for deriving said predetermined voltage value in correspondence with the time required for said moving of said aperture-defining element from one said terminal position to another; and including follow-focus means operative to selectively preempt the function of said brake means for limiting the said movement of said aperture-defining means element in correspondence with the anticipated light levels of an artificially illuminated scene.

Claim 51

The exposure control system of claim 39 in which said summing means comprises: capacitor means for deriving said adjusting voltage signal; means for selectively charging said capacitor means; and means for actuating said charging means substantially simultaneously with the initiation of said movement of said aperture-defining element.

Claim 52

The exposure control system of claim 43 in which said charging means is selected for causing said predetermined voltage signal value to be generated at said capacitor means following a generation time at least equivalent to the time required for said moving of said aperture from one said terminal position to another.

Claim 53

The exposure control system of claim 43 in which said charging means is selected for causing said predetermined voltage signal value to be generated at said capacitor means following a generation time at least equivalent to the time required for said moving of said aperture from one said terminal position to another; and including follow-focus Means operative to selectively preempt the function of said brake means for limiting the said movement of said aperture-defining means element in correspondence with the anticipated light levels of an artificially illuminated scene.

Claim 54

The exposure control system of claim 45 including: means for illuminating said scene to be photographed with artificial illumination; means for energizing said illuminating means substantially at the commencement of said interval of exposure; timing means isolated from said light-sensitive circuit means signal for generating an auxiliary output voltage signal having a select level following a predetermined interval commencing substantially simultaneously with the said energizing of said artificial illumination means; and voltage-sensitive switching means responsive to said auxiliary voltage signal for overriding said light-sensitive circuit means signal to cause the insertion of a voltage signal into said shutter-activating means, whereby said exposure interval may be terminated following a select, maximum period of time.

Claim 55

An exposure control system for use with photographic apparatus comprising: an exposure mechanism having at least one controllable exposure parameter for regulating the exposure of a photosensitive material; light detector means having an electrical parameter responsive to the light level of a scene to be photographed; means responsive to said electrical parameter and forming a light-sensitive circuit with said light detector means for deriving an output signal responsive to the said light level of said scene; amplifier means coupled to receive said light-sensitive circuit output signal and having a selectable gain corresponding with the sensitometric properties of said photosensitive material for adjusting said output signal in accordance therewith; and means responsive to said adjusted output signal for controlling said exposure parameter.

Claim 56

An exposure control system for use with photographic apparatus comprising: an exposure mechanism having at least one controllable exposure parameter for regulating the exposure of a photosensitive material; light detector means having an electrical parameter responsive to the light level of a scene to be photographed; means responsive to said electrical parameter and forming a light-sensitive circuit with said light detector means for deriving an output signal responsive to the said light level of said scene; amplifier means coupled to receive said light-sensitive circuit output signal and having a selectable gain corresponding with the sensitometric properties of said photosensitive material for adjusting said output signal in accordance therewith; and means responsive to said adjusted output signal for controlling said exposure parameter.

Claim 57

The exposure control system of claim 47 wherein said amplifier means comprises a differential amplifier having a feedback circuit incorporating impedance means connected between its input and output, said impedance means being selected for deriving said gain.

Claim 58

The control system of claim 47 including: impedance means coupled between said light-sensitive circuit means and the input of said amplifier means for calibrating said light-sensitive circuit means.

Claim 59

The control system of claim 47 in which said amplifier means is present as a differential amplifier.

Claim 60

The exposure control system of claim 50 in which said amplifier means includes a feedback circuit incorporating resistor means having an impedance value selectable for calibrating said light-sensitive circuit means.

Claim 61

The exposure control system of claim 50 including: impedance means coupled between said light-sensitive circuit means and the input of said differential amplifier, said impedance means having a value of impedance selectable to derive said gain.

Claim 62

The exposure control system of claim 50 including: first impedance means coupled in series between said light-sensitive circuit means and the input of said differential amplifier; said differential amplifier includes: a feedback path coupled between the input and output thereof, said path including second impedance means; and the impedance value of one of said first and second impedance means is selected in correspondence with said sensitometric properties.

Claim 63

The exposure control system of claim 53 in which the impedance value of one of said first and second impedance means is selected in correspondence with said sensitometric properties and the impedance value of the other of said first and second impedance means is selected for calibrating said light-sensitive circuit means.

Claim 64

An exposure control system for photographic apparatus comprising: an exposure mechanism including means defining an exposure aperture having an effective area representing a firSt exposure parameter and for uncovering and covering said exposure aperture for an interval of time representing a second exposure parameter so as to regulate the exposure of a photosensitive material; light-sensitive circuit means responsive to the light levels of a scene being photographed and operable in a first mode for providing an output signal evaluating said first parameter and in a second mode for providing an output signal evaluating said second parameter; a differential amplifier coupled to receive and adjust said light-sensitive circuit output signals; a feedback path having a select first impedance coupled between the input and output of said amplifier; a second impedance means coupled in series between said light-sensitive circuit means and said differential amplifier input for varying said output signals; means for selectively varying the impedance value of at least one said first impedance and second impedance means so as to adjust the gain of said amplifier in correspondence with the sensitometric properties of said photosensitive material; and means responsive to said adjusted output signals for controlling said first and second exposure parameters.

Claim 65

An exposure control system for photographic apparatus comprising: an exposure mechanism including means defining an exposure aperture having an effective area representing a firSt exposure parameter and for uncovering and covering said exposure aperture for an interval of time representing a second exposure parameter so as to regulate the exposure of a photosensitive material; light-sensitive circuit means responsive to the light levels of a scene being photographed and operable in a first mode for providing an output signal evaluating said first parameter and in a second mode for providing an output signal evaluating said second parameter; a differential amplifier coupled to receive and adjust said light-sensitive circuit output signals; a feedback path having a select first impedance coupled between the input and output of said amplifier; a second impedance means coupled in series between said light-sensitive circuit means and said differential amplifier input for varying said output signals; means for selectively varying the impedance value of at least one said first impedance and second impedance means so as to adjust the gain of said amplifier in correspondence with the sensitometric properties of said photosensitive material; and means responsive to said adjusted output signals for controlling said first and second exposure parameters.

Claim 66

The exposure control system of claim 55 in which said first impedance is provided by at least one resistor having a resistance value which is selected in correspondence with said sensitometric properties.

Claim 67

The exposure control system of claim 56 in which said second impedance means comprises at least one resistor having a resistance value selected for calibrating said light-sensitive circuit means for said second operational mode.

Claim 68

The exposure control system of claim 55 in which said second impedance means comprises at least one resistor having a value of resistance selected in correspondence with said sensitometric properties.

Claim 69

The exposure control system of claim 58 in which said first impedance is provided by at least one resistor having a resistance value selected for calibrating said light-sensitive circuit means for said second operational mode.

Claim 70

An exposure control system for photographic apparatus comprising: means defining an exposure aperture having an effective area variable between select terminal values; shutter means for uncovering and covering said exposure aperture means for select intervals of time; aperture control mechanism means for regulating said variable effective area; shutter control mechanism means for regulating said shutter means; light-sensitive circuit means responsive to the light levels of a scene to be photographed and operable sequentially in an aperture regulation mode and shutter regulation mode for providing output voltage signals in correspondence therewith; first voltage-sensitive trigger circuit means having an input stage coupled to receive said output voltage signals and responsive to a predetermined voltage level for actuating said aperture control mechanism means; second voltage-sensitive trigger circuit means having an input stage coupled in common with said first trigger circuit means input stage to receive said output signals and responsive to a predetermined voltage level for actuating said shutter control mechanism means; and means coupled with said second trigger circuit means for selectively adjusting the level of said light-sensitive circuit means output voltage signals, whereby said first and second voltage sensitive trigger circuit means are operative to function respectively in sequence to actuate said aperture and shutter control mechanism means.

Claim 71

An exposure control system for photographic apparatus comprising: means defining an exposure aperture having an effective area variable between select terminal values; shutter means for uncovering and covering said exposure aperture means for select intervals of time; aperture control mechanism means for regulating said variable effective area; shutter control mechanism means for regulating said shutter means; light-sensitive circuit means responsive to the light levels of a scene to be photographed and operable sequentially in an aperture regulation mode and shutter regulation mode for providing output voltage signals in correspondence therewith; first voltage-sensitive trigger circuit means having an input stage coupled to receive said output voltage signals and responsive to a predetermined voltage level for actuating said aperture control mechanism means; second voltage-sensitive trigger circuit means having an input stage coupled in common with said first trigger circuit means input stage to receive said output signals and responsive to a predetermined voltage level for actuating said shutter control mechanism means; and means coupled with said second trigger circuit means for selectively adjusting the level of said light-sensitive circuit means output voltage signals, whereby said first and second voltage sensitive trigger circuit means are operative to function respectively in sequence to actuate said aperture and shutter control mechanism means.

Claim 72

The exposure control system of claim 60 including: a DC power source having terminal outputs of opposite polarity; and means for coupling said first and second voltage-sensitive circuit means in series across said power source so as to establish a reference level for said light-sensitive circuit means.

Claim 73

The exposure control system of claim 61 including compensating means for maintaining thE voltage relationship between at least one voltage-sensitive circuit means and said reference level throughout an exposure sequence.

Claim 74

The exposure control system of claim 62 wherein said compensating means is operative in conjunction with the said voltage sensitive circuit means selected for the initial said exposure mechanism parameter control occurring during said exposure sequence.

Claim 75

The exposure control system of claim 63 in which said compensating means comprises bypass means for selectively assuming any voltage drop across said selected voltage-sensitive circuit means.

Claim 76

The exposure control system of claim 64 in which each of said first and second voltage sensitive circuit means comprises: electromagnetic means coupled between said power source terminal output and said coupling means reference level for selectively actuating said control mechanism to regulate one said exposure parameter; and a voltage-sensitive trigger circuit coupled to receive said output signal and, in response thereto, to cause the selective energization and deenergization of said electromagnetic means.

Claim 77

The exposure control system of claim 60 including alignment means coupled with the input stage of said first voltage-sensitive trigger circuit means for adjusting the voltage at said input stage to a selected value at the commencement of an exposure cycle.

Claim 78

The exposure control system of claim 60 in which said level-adjusting means comprises at least one unilaterally conductive element having a select forward resistance characteristic.

Claim 79

The exposure control system of claim 67 in which: said first and second voltage-sensitive trigger circuits are operative to switch a current supply when at least one said output voltage signal reaches a predetermined level; and said aperture and shutter control mechanism means include electromagnetic means selectively deenergizable in response to said switching.

Claim 80

The exposure control system of claim 68 in which said at least one unilaterally conductive element is selected as at least one diode.

Claim 81

An exposure control system for photographic apparatus comprising: an exposure mechanism having control means for regulating the effective area of an exposure aperture and for regulating the interval of exposure through said exposure aperture; light-sensitive circuit means responsive to the light levels of a scene to be photographed, said circuit means being operable sequentially in an aperture regulating mode and in an exposure interval regulating mode for providing output signals in correspondence therewith; a power source having output terminals of opposite polarity; first and second electromagnetic means coupled in series across said power source, for selectively actuating said exposure mechanism control means; a first voltage-sensitive trigger circuit responsive to said output signals and coupled in switching relationship with said first electromagnetic means; a second voltage-sensitive trigger circuit selectively responsive to said output signals and coupled in switching relationship with said second electromagnetic means; and alignment means coupled between one said power source output terminal and at least one said trigger circuit for assuring the responsiveness of said trigger circuit at the commencement of an exposure cycle.

Claim 82

An exposure control system for photographic apparatus comprising: an exposure mechanism having control means for regulating the effective area of an exposure aperture and for regulating the interval of exposure through said exposure aperture; light-sensitive circuit means responsive to the light levels of a scene to be photographed, said circuit means being operable sequentially in an aperture regulating mode and in an exposure interval regulating mode for providing output signals in correspondence therewith; a power source having output terminals of opposite polarity; first and second electromagnetic means coupled in series across said power source, for selectively actuating said exposure mechanism control means; a first voltage-sensitive trigger circuit responsive to said output signals and coupled in switching relationship with said first electromagnetic means; a second voltage-sensitive trigger circuit selectively responsive to said output signals and coupled in switching relationship with said second electromagnetic means; and alignment means coupled between one said power source output terminal and at least one said trigger circuit for assuring the responsiveness of said trigger circuit at the commencement of an exposure cycle.

Claim 83

The exposure control system of claim 70 wherein said alignment means comprises impedance means coupled between one said power source output terminal and the input of at least one said trigger circuit for adjusting the voltage at said input to a selected preexposure value.

Claim 84

The exposure control system of claim 71 wherein said impedance means comprises at least one capacitor.

Claim 85

The exposure control system of claim 72 in which the input of each said first and second voltage-sensitive trigger circuits includes a normally nonconducting transistor stage coupled in switching relationship to receive the output signals of said light-seNsitive circuit means.

Claim 86

The exposure control system of claim 70 wherein said light-sensitive circuit means is configured having at least one differential amplification stage functioning in conjunction with a reference level voltage; and including means for interconnecting said first and second electromagnetic means and associated said first and second trigger circuits to develop said reference level voltage at their mutual junction.

Claim 87

The exposure control system of claim 74 including compensating means for maintaining the voltage relationship between the power source coupling of at least one said electromagnetic means, its associated trigger circuit and said reference level mutual junction.

Claim 88

The exposure control system of claim 75 in which: said first voltage-sensitive trigger circuit is responsive to said output signals during said light-sensitive circuit means aperture-regulating mode; and said compensating means is operative in response to the actuation of said first voltage-sensitive trigger circuit.

Claim 89

The exposure control system of claim 76 in which said compensating means comprises: impedance means coupled in parallel with said first electromagnetic means and associated said first voltage-sensitive trigger circuit for deriving a select voltage; and switching means responsive to said first voltage-sensitive trigger circuit for selectively conducting a current supply into said impedance means.

Claim 90

The exposure control system of claim 77 in which each said first and second voltage-sensitive triggering circuits includes a normally conducting stage coupled in switching relationship respectively with said first and second electromagnetic means, said normally conductive stages being operable to deenergize said electromagnetic means in response to select levels of said output voltage signals.

Claim 91

The exposure control system of claim 78 in which said switching means includes at least one transistor stage coupled for conductive response to the deenergization of said first electromagnetic means.