Exposure control system including blade sensing follow focus and trim arrangement

• US 4,200,379 A
• Filed: 08/01/1978
• Issued: 04/29/1980
• Est. Priority Date: 08/01/1978
• Status: Expired due to Term

• Current Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Erlichman, Irving
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): Perkey, William B.
• Application Number:
  US05/930,029
• Time in Patent Office: 637 Days
• Field of Search: 354/26-30, 354/34, 354/42, 354/59, 354/139, 354/149, 354/196, 354/230, 354/47, 354/43, 354/44, 354/270, 354/271, 354/247, 354/228
• US Class Current: 396/66
• CPC Class Codes: G03B 7/087 for control of both exposure time and aperture
• CPC Class Codes: G03B 7/16 in accordance with both the intensity of the flash source and the distance of the flash source from the object, e.g. in accordance with the "guide number" of the flash bulb and the focusing of the camera

Abstract

An improved exposure control system configured for automatic operation in both the ambient light and flash illumination modes of operation and including a pair of displaceably mounted shutter-aperture blades, a blade position sensor operative to detect a blade position indicator on one of the blades, a follow focus system operable in the flash mode for moving at least an element of the sensor along a first sensor path of travel and a trim control device being operative in the flash mode for moving the sensor element along a second sensor path of travel that intersects and is tranversely disposed with respect to the first path. The sensor provides an output signal in response to sensing the blade indicator for temporarily interrupting blade displacement, incidental to flash firing, at a selected aperture value in accordance with the position of the sensor element determined by the combined follow focus and trim control inputs.

Claims

1. An improved exposure control system for regulating the transmission of image-carrying light rays from a scene along an optical path to a photographic film unit located at a given focal plane, said exposure control system being of the type including at least one blade member;

means for mounting said blade member for displacement along a given blade path of travel between first and second positions, said blade member being configured to block the optical path when located in its said first position and unblock the optical path when located in its said second position and to provide progressively changing aperture values within a given range of aperture values through which scene light may pass to the given focal plane as said blade member is displaced from said first position, each of said aperture values being in correspondence with a respective position of said blade member along said blade path of travel;

sensor means for determining when said blade means has reached a predetermined position along said blade path of travel;

said sensor means including a sensor having an actuator portion and providing a given output signal when said blade member is displaced from said first position to within a predetermined vicinity of said actuator portion;

means for mounting at least said actuator portion for displacement along a first sensor path of travel at least substantially parallel to said blade path of travel;

aperture selecting means for selecting an aperture value in correspondence with the distance to the scene to be photographed and for displacing at least said actuator portion to a predetermined location along said first sensor path of travel in accordance with said selected aperture value;

drive means being operative for displacing said blade member between its said first and second positions; and

actuating means for activating said drive means to displace said blade member from its first position toward its second position to initiate an exposure interval during which scene light is directed to the given focal plane and for then at least temporarily terminating further activation of said drive means so as to interrupt said displacement of said blade member in response to said given output signal provided by said sensor to thereby select an aperture value in operative relation to the optical path in accordance with the location of said actuator portion along said first path of travel of said sensor wherein the improvement comprises;

means for mounting at least said actuator portion of said sensor for displacement along a second sensor path of travel intersecting said first sensor path of travel and being disposed in substantially transverse relation thereto so that said actuator portion may be displaced along either one of said first or second sensor paths independently of its displacement along the other of said first and second sensor paths;

aperture trim means being operative independently of the operation of said aperture selecting means for displacing said actuator portion along said second path of travel to move said actuator portion from said predetermined location along said first sensor path of travel to make adjustment in the aperture value set by operation of said aperture selecting means;

indicator means on said blade member cooperating directly with said actuator portion for providing an indication to said actuator portion that said blade member is located within said predetermined vicinity of said actuator portion, said indicator means being configured to provide said indication at different positions of said blade member along said blade path of travel in accordance with the location of said actuator portion defined by its position along said first sensor path of travel in combination with its position along said second sensor path of travel; and

said sensor including an electrical switch having first and second contacts, said sensor actuator portion including one of said first and second contacts and said blade member including an electrically insulative portion thereof that is positioned in between said first and second contacts when said blade member is in said blocking position to maintain said switch in its nonconducting state and said insulative portion of said blade member being removed from its insulating position in response to displacement of said blade member from its blocking position toward its unblocking position thereby allowing engagement of said first and second contacts to causing said switch to assume its conducting state and provide said given output signal to said actuating means.

2. The improved exposure control system of claim 1 wherein said indicator means includes an indicator edge of said insulative portion of said blade member, said indicator edge being disposed at an oblique angle with respect to said first and second sensor paths of travel and said predetermined vicinity of said blade member with respect to said actuator portion is defined as that point along said blade path of travel toward said unblocking position at which said indicator edge is displaced sufficiently from its insulative position to allow engagement of said first and second contacts.

3. An improved exposure control system for regulating the transmission of image-carrying light rays from a scene along an optical path to a photographic film unit located at a given focal plane, said exposure control system being of the type including at least one blade member;

means for mounting said blade member for displacement along a given blade path of travel between first and second positions, said blade member being configured to block the optical path when located in its said first position and unblock the optical path when located in its said second position and to provide progressively changing aperture values within a given range of aperture values through which scene light may pass to the given focal plane as said blade member is displaced from said first position, each of said aperture values being in correspondence with a respective position of said blade member along said blade path of travel;

sensor means for determining when said blade means has reached a predetermined position along said blade path of travel;

said sensor means including a sensor having an actuator portion and providing a given output signal when said blade member is displaced from said first position to within a predetermined vicinity of said actuator portion;

means for mounting at least said actuator portion for displacement along a first sensor path of travel at least substantially parallel to said blade path of travel;

aperture selecting means for selecting an aperture value in correspondence with the distance to the scene to be photographed and for displacing at least said actuator portion to a predetermined location along said first sensor path of travel in accordance with said selected aperture value;

drive means being operative for displacing said blade member between its said first and second positions; and

actuating means for activating said drive means to displace said blade member from its first position toward its second position to initiate an exposure interval during which scene light is directed to the given focal plane and for then at least temporarily terminating further activation of said drive means so as to interrupt said displacement of said blade member in response to said given output signal provided by said sensor to thereby select an aperture value in operative relation to the optical path in accordance with the location of said actuator portion along said first path of travel of said sensor wherein the improvement comprises;

means for mounting at least said actuator portion of said sensor for displacement along a second sensor path of travel intersecting said first sensor path of travel and being disposed in substantially transverse relation thereto so that said actuator portion may be displaced along either one of said first or second sensor paths independently of its displacement along the other of said first and second sensor paths;

aperture trim means being operative independently of the operation of said aperture selecting means for displacing said actuator portion along said second path of travel to move said actuator portion from said predetermined location along said first sensor path of travel to make adjustment in the aperture value set by operation of said aperture selecting means; and

indicator means on said blade member cooperating directly with said actuator portion for providing an indication to said actuator portion that said blade member is located within said predetermined vicinity of said actuator portion, said indicator means being configured to provide said indication of different positions of said blade member along said blade path of travel in accordance with the location of said actuator portion defined by its position along said first sensor path of travel in combination with its position along said second sensor path of travel, said indicator means including an indicator portion of said blade member disposed at an oblique angle with respect to both of said first and second sensor paths of travel.

4. The improved exposure control system of claim 3 wherein said first and second sensor paths of travel are disposed in substantially perpendicular relationship to each other and said indicator means is disposed at an oblique angle of approximately 45°

with respect to said first and second sensor paths of travel.

5. The improved exposure control system of claim 3 wherein said indicator portion includes an edge of said blade member disposed at said oblique angle with respect to said first and second sensor paths of travel and said blade path of travel.

6. An improved exposure control system for regulating the transmission of image-carrying light rays from a scene along an optical path to a photographic film unit located at a given focal plane, said exposure control system being of the type including at least one blade member;

means for mounting said blade member for displacement along a given blade path of travel between first and second positions, said blade member being configured to block the optical path when located in its said first position and unblock the optical path when located in its said second position and to provide progressively changing aperture values within a given range of aperture values through which scene light may pass to the given focal plane as said blade member is displaced from said first position, each of said aperture values being in correspondence with a respective position of said blade member along said blade path of travel;

sensor means for determining when said blade means has reached a predetermined position along said blade path of travel;

said sensor means including a sensor having an actuator portion and providing a given output signal when said blade member is displaced from said first position to within a predetermined vicinity of said actuator portion;

means for mounting at least said actuator portion for displacement along a first sensor path of travel at least substantially parallel to said blade path of travel;

aperture selecting means for selecting an aperture value in correspondence with the distance to the scene to by photographed and for displacing at least said actuator portion to a predetermined location along said first sensor path of travel in accordance with said selected aperture value;

drive means being operative for displacing said blade member between its said first and second positions; and

actuating means for activating said drive means to displace said blade member from its first position toward its second position to initiate an exposure interval during which scene light is directed to the given focal plane and for then at least temporarily terminating further activation of said drive means so as to interrupt said displacement of said blade member in response to said given output signal provided by said sensor to thereby select an aperture value in operative relation to the optical path in accordance with the location of said actuator portion along said first path of travel of said sensor wherein the improvement comprises;

means for mounting at least said actuator portion of said sensor for displacement along a second sensor path of travel intersecting said first sensor path of travel and being disposed in substantially transverse relation thereto so that said actuator portion may be displaced along either one of said first or second sensor paths independently of its displacement along the other of said first and second sensor paths;

8. The improved exposure control system of claim 6 wherein said indicator means includes an indicator edge of said insulative portion of said blade member, said indicator edge being disposed at an oblique angle with respect to said first and second sensor paths of travel and said predetermined vicinity of said blade member with respect to said actuator portion is defined as that point along said blade path of travel at which said indicator edge is driven in between said first and second contacts sufficiently to cause said first and second contacts to become disengaged.

10. The improved exposure control system of claim 8 wherein said blade aperture value at which said given output signal is provided varies in accordance with the distance said actuator is displaced along said second sensor path of travel from said point of intersection with said first sensor path of travel.

7. aperture trim means being operative independently of the operation of said aperture selecting means for displacing said actuator portion along said second path of travel to move said actuator portion from said predetermined location along said first sensor path of travel to make adjustment in the aperture value set by operation of said aperture selecting means;

indicator means on said blade member cooperating directly with said actuator portion for providing an indication to said actuator portion that said blade member is located within said predetermined vicinty of said actuator portion, said indicator means being configured to provide said indication at different positions of said blade member along said blade path of travel in accordance with the location of said actuator portion defined by its position along said first sensor path of travel in combination with its position along said second sensor path of travel; and

said sensor including an electrical switch having first and second contacts, said sensor actuator portion including one of said first and second contacts, and said blade member including an electrically insulative portion that is positioned to one side of said first and second contacts when said blade member is in said blocking position so that said first and second contacts are in engagement causing said switch to assume its conductive state and said insulative portion of said blade member being adapted to be driven in between said first and second contacts to an insulating position causing said first and second contacts to become disengaged in response to displacement of said blade member towards said unblocking position whereby said switch assumes its nonconducting state and thereby provides said given output signal to said actuating means.

9. An improved exposure control system for regulating the transmission of image-carrying light rays from a scene along an optical path to a photographic film unit located at a given focal plane, said exposure control system being of the type including at least one blade member;

means for mounting said blade member for displacement along a given blade path of travel between first and second positions, said blade member being configured to block the optical path when located in its said first position and unblock the optical path then located in its said second position and to provide progressively changing aperture values within a given range of aperture values through which scene light may pass to the given focal plane as said blade member is displaced from said first position, each of said aperture values being in correspondence with a respective position of said blade member along said blade path of travel;

sensor means for determining when said blade means has reached a predetermined position along said blade path of travel;

said sensor means including a sensor having an actuator portion and providing a given output signal when said blade member is displaced from said first position to within a predetermined vicinity of said actuator portion;

means for mounting at least said actuator portion for displacement along a first sensor path of travel at least substantially parallel to said blade path of travel;

aperture selecting means for selecting an aperture value in correspondence with the distance to the scene to be photographed and for displacing at least said actuator portion to a predetermined location along said first sensor path of travel in accordance with said selected aperture value;

drive means being operative for displacing said blade member between its said first and second positions; and

actuating means for activating said drive means to displace said blade member from its first position toward its second position to initiate an exposure interval during which scene light is directed to the given focal plane and for then at least temporarily terminating further activation of said drive means so as to interrupt said displacement of said blade member in reponse to said given output signal provided by said sensor to thereby selct an aperture value in operative relation to the optical path in accordance with the location of said actuator portion along said first path of travel of said sensor wherein the improvement comprises;

means for mounting at least said actuator portion of said sensor for displacement along a second sensor path of travel intersecting said first sensor path of travel and being disposed in substantially transverse relation thereto so that said actuator portion may be displaced along either one of said first or second sensor paths independently of its displacement along the other of said first and second sensor paths;

aperture trim means being operative independently of the operation of said aperture selecting means for displacing said actuator portion along said second path of travel to move said actuator portion from said predetermined location along said first sensor path of travel to make adjustment in the aperture value set by operation of said aperture selecting means; and

indicator means on said blade member cooperating directly with said actuator portion for providing an indication to said actuator portion that said blade member is located within said predetermined vicinity of said actuator portion, said indicator means being configured to provide said indication at different positins of said blade member along said blade path of travel in accordance with the location of said actuator portion defined by its position along said first sensor path of travel in combination with its position along said second sensor path of travel, said indicator means including an indicator edge of said blade member being disposed at an oblique angle with respect to first and second sensor paths of travel such that said indicator edge interacts with said actuator portion to provide said given output signal at a given blade aperture value when said actuator portion is located at a given position along said first sensor path of travel at a point of intersection with said second sensor path of travel, to provide said given output signal at a blade aperture value smaller than said given blade aperture value when said actuator portion is at a location along said second sensor path of travel to one side of said point of intersection with said first sensor path of travel and to provide said given output signal at a blade aperture value greater than said given blade aperture value when said actuator portion is at a location along said second sensor path of travel on the opposite side of said point of intersection with said first sensor path of travel.