US3820128A - Flash photographic control system - Google Patents

Flash photographic control system Download PDF

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Publication number
US3820128A
US3820128A US00333331A US33333173A US3820128A US 3820128 A US3820128 A US 3820128A US 00333331 A US00333331 A US 00333331A US 33333173 A US33333173 A US 33333173A US 3820128 A US3820128 A US 3820128A
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United States
Prior art keywords
exposure
responsive
control system
illumination
source
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Expired - Lifetime
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US00333331A
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English (en)
Inventor
J Burgarella
P Carcia
R Kee
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Polaroid Corp
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Polaroid Corp
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Publication date
Application filed by Polaroid Corp filed Critical Polaroid Corp
Priority to US00333331A priority Critical patent/US3820128A/en
Priority to GB1796673A priority patent/GB1391293A/en
Priority to CA169,112A priority patent/CA998865A/en
Priority to FR7314655A priority patent/FR2226075A5/fr
Priority to JP4605573A priority patent/JPS5716336B2/ja
Priority to DE2320676A priority patent/DE2320676C2/de
Application granted granted Critical
Publication of US3820128A publication Critical patent/US3820128A/en
Priority to CA223,863A priority patent/CA999176A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B15/00—Special procedures for taking photographs; Apparatus therefor
    • G03B15/02—Illuminating scene
    • G03B15/03—Combinations of cameras with lighting apparatus; Flash units
    • G03B15/04—Combinations of cameras with non-electronic flash apparatus; Non-electronic flash units
    • G03B15/0452—Electrical ignition means connected to the shutter
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B7/00—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
    • G03B7/08—Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B7/00—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
    • G03B7/08—Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device
    • G03B7/091—Digital circuits
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B7/00—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
    • G03B7/16—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly 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
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B9/00—Exposure-making shutters; Diaphragms
    • G03B9/58—Means for varying duration of "open" period of shutter

Definitions

  • ABSTRACT A flash photographic control system for use within a highly automatic reflex camera of a variety utilizing a flash firing circuit in conjunction with a packaged array of flashlamps.
  • the firing circuit ignites the flashlarnps sequentially in a predetermined order from first to last.
  • the control system is characterized in electrically isolating the firing circuit during portions of a photographic cycle during which it would otherwise be subjected to spurious signals or noise effects. Additionally, an arrangement is provided wherein the control system overrides the flash firing network under select scene conditions of high brightness.
  • a thin and compact, yet fully-automatic handheld reflex camera is described in a copending application four United States patent entitled, REFLEX CAM- ERA, by E. I-l. Land, I. Blinow, and V. K. Eloranta, Ser. No. 134,733 filed Apr. 16, 1971, and assigned in common herewith.
  • the automatic camera necessarily is highly complex, being capable of performing a significant number of operational events in the course of a single photographic cycle. For example, during a preexposure phase of such a cycle, the instrumentalities or control components of the camera are called upon to initially fully close an exposure mechanism. This activity secures the exposure chamber of the camera by blocking its taking optical path.
  • the exposure mechanism is driven to its blocking orientation by the continuous energization of a tractive electromagnetic device in the form of a solenoid.
  • a tractive electromagnetic device in the form of a solenoid.
  • a motor is energized for a short period of time to cause the unlatching of a reflex component, thereby causing it to be driven under spring bias into an orientation altering the optical path for purposes of exposing a film unit.
  • an exposure phase of the camera ensues wherein the solenoid drive of the exposure mechanism is de-energized to permit a gradual unblocking of the optical path of the camera.
  • the exposure phase is terminated upon reenergization of the noted solenoid drive and consequent blocking of the optical path.
  • the photographic cycle of the camera continues into a postexposure phase.
  • the exposure mechanism solenoid continues to be energized while the motor again is energized to cock the reflex component into its initial orientation.
  • the driven instrumentalities of the camera remove an exposed film unit from the exposure chamber and process it through the driven rolls of a processing station.
  • the post-exposure phase of the photographic cycle ends when the system is shut down to de-energize both the motor and exposure mechanism drive solenoid.
  • the exposure mechanism of the camera is regulated from a light-sensing network having light detecting elements which monitor both scene brightness and corresponding instantaneous exposure values.
  • the exposure mechanism is one which continuously varies aperture in the course of a given exposure interval under a program selected to optimize both aperture selection and taking speed.
  • the light-sensing network signals the control system of the camera to energize the exposure mechanism solenoid to terminate an exposure. Activation of the lightsensing network is carried out by an electronic form of switching operating in. synchronism with exposure mechanism actuation.
  • Flashlamp illumination for the noted camera is provided by a lighting system utilizing a multiple flashlamp arrangement wherein a plurality of flashlamps are mounted as an array within a singular disposable package. All of the thus arrayed lamps are oriented for providing scene illumination, when ignited, without recourse to moving or rotating either the flashlamps or their mountings between exposures. Since no relative movement of the flashlamps is involved between exposures, the system includes a firing circuit which sequentially ignites the bulbs in a predetermined order with each photographic cycle. Exposure control for flash mode operation is carried out by a separate control system based upon a follow-focus approach. With this system, the blades of the exposure mechanism are selectively arrested during their opening movement to define a fixed apertural value.
  • This value is automatically determined during focusing procedures, the arresting feature being mechanically linked with the focusing mechanism of the camera.
  • Design of the followfocus mechanism is based upon the inverse square law of light energy propagation in which light intensity is considered to vary inversely with the distance from its source.
  • Actuation of an arresting linkage for the flash control system is provided by a'tractive electromagnetic device, for instance, another solenoid. Once the blades of the exposure mechanism are arrested at an appropriate aperture, the flash firing circuit is actuated to ignite a selected flashlamp and afixed exposure interval ensues which is terminated upon energization of the exposure mechanism solenoid to block the optical path of the camera. A post-exposure phase of the photographic cycle is then carried out.
  • the exposure control system when in an ambient illumination mode, be capable of overriding the flash control system under certain photographic circumstances.
  • the ambient mode control system may providev higher quality photography through a programmed selection of higher relative aperture values.
  • the control system of the camera preferably should provide for overriding the flash illumination mode control system while, additionally, preventing the igniting of a flashlamp.
  • the present invention is addressed to a control system for photographic apparatus in the form of a highly automatic reflex camera of a variety utilizing a firing circuit to selectively and sequentially ignite individual flashlamps within an array thereof.
  • the control system electrically isolates the firing circuit substantially during all but the exposure phase of its elaborate photographic cycle. For instance, the flash firing circuit is de-energized during periods of motor drive operations as well as during those intervals when the shutter driving solenoid of the camera is energized. By so isolating the operation of the firing circuit, a highly desirable lessening of drain from the limited battery power supply of the camera is realized.
  • the flash firing circuit arrangement of the control system also is utilized in a manner deriving a preference for ambient illumination mode control under scene conditions of high brightness.
  • the light sensing network of the ambient illuminational control function of the system is deactivated only following the ignition of a flashlamp. This feature also permits the automatic camera to complete a photographic cycle in ambient mode fashion in the event a flashlamp fails to ignite.
  • the inventive system provides for the derivation of a unique output signal from'its flash firing circuit. This signal is utilized not only for initiating flash interval timing, but also for deriving the noted ambient operational mode preference feature.
  • a further feature and object of the invention is to provide a photographic control system having an operational mode for flash illumination which performs in conjunction with an operational mode for ambinet illumination over select high brightness scene illumination conditions.
  • an exposure mechanism which develops progressively varying aperture values during an ambient operational mode is utilized in conjunction with an interceptor arrangement to establish focus responsive aperture values when'operated in a flash illumination mode.
  • the system is operative during the flash illumination mode to actuate the exposure mechanismto terminate an exposure following a fixed interval. Under select scene conditions of high brightness, such actuation is permitted to take place under circumstances wherein the light-sensitive circuit of the camera is disabled only following a select point in time within the exposure phase of a photographic cycle.
  • the control system is operative to disable the lightsensitive circuit of the ambient mode portion of the system only in response to the ignition of a flashlamp.
  • a tractive electromagnetic device such as a solenoid is utilized for purposes of providing a focus-responsive arrest of the exposure mechanism.
  • the control circuit initially de-energizes all electromagnetic devices within the system before the commencement of an exposure phase and, subsequently, de-energizes the arresting solenoid to derive a pulse for actuating the flash firing circuit. When a flashlamp is fired, all electromagnetic instrumentalities are in a de-energized condition.
  • Another feature and object of the invention is to provide a control system for a highly-automated photographic camera which includes photographic instrumentalities for carrying out photographic cycles for flash and ambient illuminative modes. These photographic 'cycles includes a pre-exposure operational phase, an exposure operational phase, and a postoperational phase.
  • the instrumentalities further incorporate electromagnetic actuators which are selectively energizable and de-energizable to derive the noted cycle operational phasesin a predetermined order from first to last.
  • the system further includes a firing circuit actuable, when energized, to effect the ignition in predetermined sequence of a flashlamp within an array of such flashlamps.
  • control arrangement for selectively regulating the instrumentalities to carry out the operational phases in their predetermined order and which is operative during the noted flash illuminative mode cycle to effect the actuation of the firing circuit when the electromagnetic actuators are in a de-energized condition.
  • the system further may include an arrangement for imparting a preference to ambient illumination mode operation under selectively high scene brightness conditions. This preference is derived in conjunction with a select deenergization of one of the electromagnetic actuators within the noted instrumentalities.
  • the invention accordingly, comprises the system and apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure.
  • FIG. 1 is a pictorial view of a fully-automatic handheld camera incorporating the control system features of the instant invention, the view having portions broken away or removed to reveal internal structure;
  • FIG. 2 is a partial pictorial representation of switching features of the camera of FIG. 1 with portions broken away to reveal internal structure;
  • FIG. 3 is a partial plan view of an exposure mechanism which is incorporated in the camera of FIG. 1;
  • FIG. 4 is a block logic diagram showing the sequence of events occurring during operational cycles of the camera of FIG. 1; 1
  • FIG. 5 is a fragmentary detail view of a portion .of the mechanism revealed in FIG. 3;
  • FIG. 6 is a partial top view showing follow-focus components of the mechanism of FIG. 3 in a stand-bycondition
  • FIG. 7 is a partial top view of the follow-focus components of the mechanism of FIG. 3, similar to FIG. 6, but showing an orientation of components during an energized state of the solenoid thereof;
  • FIG. 8 is a schematic diagram of a control circuit used in conjunction with the control system of the camera of FIG. 1;
  • FIG. 9 is a truth table or schedule of operational events performed by the control system of the camera of FIG. 1, showing in logic form, the input and output states of gate functions incorporated within the circuit of FIG. 8 as it operates under ambient lighting conditions;
  • FIG. 10 is an energization status chart for various components of the circuit of FIG. 8 as they operate throughout a photographic cycle under ambient illumination conditions;
  • FIG. 11 is a truth table or schedule of operational events performed by the control system of the camera of FIG. 1, showing, in logic form, the input and output states of gate functions of the circuit of FIG. 8 when that circuit is operated for flash mode performance;
  • FIG. 12 is an energization status chart for various components of the circuit of FIG. 8 as they operate in a flash operational mode;
  • FIG. 13 is a schematic diagram of select components of a flash firing circuit which may be incorporated within the system of the instant invention.
  • FIG. 14 is a schematic diagram in greater detail of the flash firing circuit of FIG. 13 illustrating its feedback to overall camera system
  • FIG. 1 a fully-automatic reflex camera incorporating the features of the instant invention is portrayed generally at 10.
  • the several articulated housing components of camera 10, including rear wall 12, forward wall 14 and exposure control housing 16 are pivotally associated with a base 18 so as to be foldable thereinto in nesting fashion. When so folded from the erected configuration shown, the camera assumes a thin and compact shape 'suiting'it to be conveniently carried in the pocket of a garment.
  • the specific hinge connections providing for the articulated structure while not being visible in the figure, are positioned at axes 20, 22, 24 and the lower rear portion of exposure housing 16. I a
  • rear wall 12, forward wall 14, and exposure control housing 16 combine in conjunction with an opaque flexible bellows, a fragment of which is illustrated at 26, to define an exposure chamber generallydepicted at 28.
  • Base 18 includes an inner frame assembly, a portion of which is shown at 30.
  • Inner frame assembly 30, as well as the outward portions of base 18, cooperate to provide structural support for numerous instrumentalities of the camera.
  • frame is configured to define a receiving chamber for retaining and securing a film laden cassette 32 at the bottom of exposure chamber 28.
  • Cassette 32 is of generally flat, rectangular-shape and contains a stacked assemblage of photographic film units, one of which isshown at 34. Film units as at 34 are arranged for sequential presentation at a light entrance portion of cassette 32which is defined by a ridge 36. The underside of ridge 36 serves as a seat against which the uppermost one of the film units abuts.
  • cassette 32 The forward wall of cassette 32 is formed having an elongate slot 38 disposed thereacross. Slot 38 serves as an egress means providing for the sequential removal of each film unit as at 34.
  • Cassette 32 is also formed having slots or openings in the upward face thereof as at 40. Slots 40 permit the insertion of a component of a pick mechanism which functions to impart initial movements to the film units as they are removed from the cassette. 4
  • Camera 10 operates in a modified reflex fashion, being convertible between viewing and exposure operational orientations by a reflex assembly, including an operator arrangement formed as a somewhat planar reflex reflecting component 50. Shown at an intermediate position evidenced during a transition from one terminal position to another, the component 50 is configured having a mirror surface 52 mounted upon its underside, and a viewing surface 54, positioned upon or forming its upward surface. In the course of a photographic cycle, reflex component 50 is moved from a viewing position against ridge 36 of cassette 32, where it serves to secure the light entrance portion thereof, to an exposure position abutting against a mirror 56 located upon the inner side of rear wall 12. Movement between the viewing and exposure positions is pivotal, the component being coupled to inner frame 30 at hinges 58 and 60. 7
  • a viewing optical path is established.
  • This path extends from a taking lens mounted at 64 in exposure housing 16, through an exposure mechanism depicted generally at 66, which establishes an aperture opening of maximum available width, thence to the reflecting surface of mirror 56 at the rear of the camera and thence to viewing surface 54 at the upward side of component 50.
  • Viewing surface 54 is configured having a texture and optical design facilitating the focusing of the image of the scene to be photographed. This image may be viewed by the camera operator through a collapsible optical viewing assembly depicted generally at .68.
  • a configuration suited for viewing surface 54 is described and claimed in a copending application for US. Pat. Ser. No.
  • the exposure optical path orientation of camera 10 is established by pivoting reflex component 50 substantially against the inner surface of. rear wall 12. In this orientation, the optical path nowextends from taking lens 64 and exposure mechanism 66 to mirror 52, positioned on the underside of reflex component 50, thence to the uppermost one of the film or photographic units positioned beneath ridge 36 of cassette 32. Note that such uppermost film unit is located at the exposure plane of camera 10.
  • exposure mechanism 66 defines an aperture of maximum available light transmissability, while reflex component 50 is held in a light-securing position over ridge 36 and, consequently, the exposure plane of camera 10.
  • Component 50 is retained in its light-securing position by a driven instrumentality operating through hinge 58.
  • a driven instrumentality operating through hinge 58.
  • the driven instrumentality is regulated from a control system which utilizes the output of a motor 70 to selectively drive an elongate, thin gear train, certain components of which are shown generally at 72, extending along one side of camera 10.
  • the various gear components of gear train 72 are rotatably mounted upon camera 10 between inner frame 30 and an outer plate 74 (FIG. 2).
  • gear train 72 Two reduction ratio circuits are present in gear train 72, one such circuit terminating in a phase control cam 76 which is rotatably driven through one revolution during the course of a single photographic cycle.
  • Cam 76 operates in conjunction with a cam follower 78 positioned upon the inwardly facing side of an elongate ram or actuator 80.
  • Ram 80 is slideably mounted for movement along gear train 72 between the outer face thereof and outer plate 74 and is driveably connected to an input bell crank 82 mounted, in turn, at the rear of camera 10.
  • Input bell crank 82 is connected by a spring linkage to reflex component 50 at hinge 58.
  • this spring linkage provides a drive spring feature utilized to move component 50 into its exposure position, as well as an override spring system feature, pennitting cocking operations to proceed, even though component 50 may be stuck in an upward position.
  • reflex component 50 throughout any given photographic cycle is controlled by select energizations of motor 70 and consequent rotation of phase control cam 76.
  • cam follower 78 and ram 80 serve to retain reflex component 50 in its exposure plane securing position over ridge 36 of cassette 32.
  • cam 76 is in a radial orientation wherein it holds follower 78 and associated ram 80 at a terminal rearward position against the bias exerted by the noted spring linkages utilized'to'drive component 50 and exerted through .input bell crank 82.
  • Acontrolled'energization of motor 70 early in a given photographic cycle causes the gear train 72 to rotate cam 76 to a position whereat follower 78 releases from contact therewith, permitting ram 80 to be driven along with and in correspondence with reflex component 50 into their respective terminal positions.
  • ram 80 and reflex component 50 operate in corresponding synchronism, ram 80 servingas a dynamic tracking device.
  • Switch S additionally includes a resilient leaf 96 which is supportedalong with leaf 94 from an insulative base 98 fixed to outer plate 74 of base 18. Accordingly, the contacts represented by leaves 94-and 96 of switch S are opened substantially in synchronism with the initial movement of component 50 from its viewing position.
  • reflex component 50 The spring biased rotational travel of reflex component 50 about its hinges 58 and 60 from its seated exposure position entails about 37.
  • reflex component 50 somewhat closely approaches this seated position against rear wall 12 and mirror 56, Le, at about 32, tab 90 contacts the insulative cap 100 of a resilient leaf 108.
  • Station 108 is comprised of two cylindrical rolls 110 and 112 mounted within an access door, the cover of which is shown at 114.
  • Roll 110 of the station is connected with gear train 72 through a drive pinion 116.
  • a pick mechanism illustrated generally at 120 is actuated to engage the uppermost photographic film units as at 34, and to move it through forwardly disposed egress slot 38 and into the bite or point of tangency between rotating processing rolls 110 and 112 of station 108.
  • mechanism 120 includes a carriage assembly 122 which is selectively driven from a cam (not shown) present within gear train 72.
  • carriage 122 is configured supporting a resilient pick member 126.
  • the outer tip 128 of pick member 126 is configured to extend into and slide along slot 40 of cassette 32.
  • Carriage 122 is spring biased to position tip 102 of another switch depicted generally as S Leaf 102 is normally in contact with a second leaf 104 of switch S and both leaves are supported from an insulative base 106, also fixed to outer plate 74.
  • Serving to monitor the movement of reflex component 50 the open contacts of switch 5;, provide a signal condition evidencing that the component 50 has approached its seated position against rear wall 12.
  • a post exposure phase of a photographic cycle is carried out by reenergizing motor to drive gear train 72, thereby rotating phase control cam 76.
  • cam 76 As cam 76 is rotated, contact is reasserted with follower 78 to drive ram rearwardly and cock reflex component 50 into its viewing position.
  • a second reduction circuit within gear train 72 functions to drivea processing station shown generally at 128 at the rear of slot 40 of cassette 32. At this position, tip 128 engages the rear edge of a photographic unit 34.
  • the assembly of carriage 122 and pick 126 moves the uppermost one of the photographic film units through slot 40 until it is engaged by the roll of processing station 108.
  • Carriage 122 is latched at its forwardmost position following performance of its pick function and is returned under spring bias to its rearward station at the completion of the photographic cycle.
  • Photographic units 34 are processed by the pressure applied from rolls and 112 of processing station 108 as they are drawn therethrough. Described in detail in a U.S. patent by E. H. Land, No. 3,145,644, these units are structured to contain a processing fluid which is spread therewithin to cause the formation of a visible positive image.
  • the exposure control system of camera 10 is called upon to perform a number of operational steps in the course of a photographic cycle. For instance, it is required to operate exposure mechanism 66 in a manner establishing an aperture opening of maximum width or light transmissibility for viewing and focusing purposes. During the conversion of the optical path of camera 10 from a viewing orientation to an exposure orientation, mechanism 66 is retained in a fully closed condition to secure exposure chamber 28. Further, in the courseof an exposure interval, mechanism 66 and its related control provides for a dual exposure parameter regulation in which both aperture and exposure interval are controlled in accordance with a predetermined, optimized photographic program. For instance, under such a program, relative aperture should be selected automatically to optimize depth of field, while exposure interval is selected to maximize taking speed.
  • exposure mechanism 66 is shown to be formed having two blades, and 142, which slidably ride in a track (not shown) mounted within exposure housing 16.
  • Each blade, 140 and 142 is formed having a teardrop shaped apertured opening as shown, respectively, at 144 and 146. Additionally, the blades are formed having secondary openings, shown respectively at 148 and 150, (FIG. 1) which move in synchronism with openings 142 and 144 before the detecting elements of a photosensing network positioned behind an entrance optical assembly 152. Openings 144 and 146 of respective blades 140 and 142 are positioned for movement across the optical path of camera as it is established at taking lens 64.
  • openings 144 and 146 symmetrically overlap to define selectively varying aperture sizes.
  • Secondary openings 148 and 150 are configured somewhat in correspondence with the contours of respective openings 144 and 146 and also move in mutual symmetry over the optical path of the light sensing network of the control system of thecamera.
  • Blades 140 and 142 are moved in mutual symmetry as a result of their connection with a walking beam type actuator shown at 154.
  • Walking beam 154 is formed having a centrally disposed hub portion 156 which is journalled for rotation about an upstanding stud (not shown) extending from the rear casting 158 of exposure control housing 16.
  • Elongate slots as at 160 and 162 are formed in the tip portions of walking beam 154 for the purpose of providing connection with pins 164 and 166 extending, respectively, from blades 140 and 142.
  • a bias urging walking beam 154 to move blades 140 and 142 into a closed orientation is provided by a closing spring 168 (FIG. 3). Wound about hub 156, the stationary end of spring 168 is grounded against a pin 170 extending from rear casting 158, while its moving end is wound about the lower portion of walking beam 154.
  • Actuation of blades 140 and 142 for purposes of controlling exposure as well as for securing the exposure chamber 28 is carried out by a tractive electromagnetic device present as a solenoid 172.
  • solenoid 172 Described in detail in a copending application for US. Patent by C. C. Petersen, entitled Tractive Electromagnetic Device Ser. No. 245,884 filed Apr. 21, 1972, and assigned in common herewith, solenoid 172 is formed having an excitation winding 174 which is wound about a bobbin 176 attached, in turn, to a U-shaped frame 178.
  • a cylindrically shaped plunger 180 is slidably mounted within a corresponding central opening within bobbin 176 and the composite assembly is fixed to rear casting 158.
  • Plunger 180 is biased to move outwardly from its retracted position within excitation winding 174 by an opening spring 182.
  • opening spring 182 is constrained between frame 178 and an outer striker cap 184 fixed to the outer extremity of plunger 180.
  • Cap 184 is positioned to establish an abuttable contact with an upstanding pin 186 extending from the lower portion of walking beam 154.
  • the loading or force value characteristics of spring 182 are selected as being greater than the loading characteristics of closing spring 168. Accordingly, when excitation winding 174 is de-energized, spring 182 urges plunger 180 outwardly to contact pin 186 and drive walking beam 154 toward positions establishing progressively widening apertures.
  • blades 140 and 142 define an opening of maximum aperture width, as shown in FIG. 3.
  • plunger 180 is retracted thereinto at a rate negating the noted abutting contact force between cap 184 and pin 186.
  • walking beam 154 is permitted to rotate under the bias closing spring 168 to drive blades and 144 into an aperture closing orientation as shown in FIG. 1.
  • the retracted orientation of spring 182 and cap 184 is shown in FIG.
  • switch'S is formed having an upstanding insulated base 188 fixed, in turn, to frame 178.
  • Base 188 supports an elongate contact rod 190, the upwardly extending portion of which is configured to wipe across two separate conducting surfaces 192 and 194.
  • solenoid 172 is energized and its plunger is retracted, however, a pin 198 extending laterally from cap 184 drives contact rod rearwardly to wipe against and make electrical contact with conducting surface 192.
  • Conducting surfaces 192 and 194 are relatively closely spaced such that electrical contact is effected with surface 192 when plunger 180 is closely proximate its fully retracted and seated position. Conversely, contact rod 190 effects electrical contact with conducting surface 194 very rapidly upon deenergization of solenoid 172. Preferably, this contact is made before shutter blades 140 and 142 are permitted to define an aperture opening.
  • AMBIENT CYCLE OPERATION Referring additionally to FIG. 4, the operational events sequence defining a photographic cycle as camera 10 operates under ambient illuminational conditions is displayed in block logic form. For instance, upon erecting camera 10 to the configuration shown in FIG. 1, the operator views and focuses a scene to be photographed through optical assembly 68. To optimize this viewing, blades 140 and 142 of exposure mechanism 66 are fully opened as depicted at function block 204. Additionally, the exposure plane of the camera is blocked by reflex component 50 as it is positioned over ridge 36 of cassette 32. This securing of the exposure plane is depicted by function block 206.
  • a photographic cycle is commenced with the depression of a start button 208 located on a forward face of control housing 16 (FIG. 1). Depression of this button closes appropriate switching to energize the control system of a camera which, in turn, effects the energization of winding 174 of solenoid 172.
  • solenoid 172 retracts plunger 180, permitting closingspring 168 to drive walking beam 154 in a direction moving blades 140 and 142 into the closed position shown in FIG. 1.
  • the initial closure of exposure mechanism blades 140 and 142 upon depression of start button 208 commences a pre-exposure phase of the photographic cycle. The extent of this phase and succeeding ones is bracketed and labelled in FIG. 4.
  • Switch S is opened. Serving as a transducer stage for monitoring the movement of reflex component 50, the. open contacts of switch 5;, provide a signal condition evidencing that component 50 has approached its seated position.
  • switch S the control system of the camera provides a delay function as indicated at block 214. This delay is predetermined, beingselected to accommodate for any dynamic instability'such as bouncing or the like which reflex component'50 may exhibit against itsseated position in rear wall 12.
  • the light sensing network of the control system evaluates scene lighting from entrance assembly 152 as it is affected by moving openings 148 and 150. (FIG. 1)
  • This light responsive regulation function is depicted at block 218.
  • a trigger within the circuit thereof is fired, as depicted at function block 220, and excitation winding 174 is again energized to cause the retraction of plunger 180 and rapid closure of blades 140 and 142.
  • This exposure terminating function concludes the exposure phase of a given photographic cycle and is depicted at block 222.
  • FLASH CYCLE OPERATION a photographic cycle of camera 10 has been described as -it relates to operation under ambientlighting conditions.
  • a packaged linearly arrayed multiflashlamp assembly such as that shown in FIG. 1 at 234 is mounted upon exposure housing 16.
  • assembly 234 serves to arm or activate a flash control logic within the control system of the camera by closing a switch (FIG. 8) designated S the discussion to follow.
  • F IG. 4 also depicts a resulting flash mode photographic cycle, the noted control logic activation occasioned from insertion of flash array 234 and closure of switch S being depicted by function block 236.
  • the flash mode cycle includes a.
  • a second, follow-focus solenoid 240 forming part of exposure mechanism 66, is energized.
  • Such energization is depicted at function block 242 in FIG. 4.
  • Solenoid 240 represents the drive component of a follow-focus Y phy, Ser. No. 168,671, filed on Aug. 3, 1971 and assigned in common herewith.
  • This follow-focus mechanism provides a mechanical coupling between the focusing system of camera andthe aperture adjusting feature of exposure mechanism66.
  • taking lens 64 is mounting inan externally threaded bezel, the threaded periphery of which is depicted in phantom in 244. Selective rotation of this bezel serves to provide a focusing function for the camera.
  • Periphery 244 is threadibly engaged with the teeth of an idler gear 246 which is mounted for rotation about an upstanding stud 248 fixed, in turn, to rear casting 158.
  • Gear 246 is retained upon stud 248 by a flat faced screw 250. which is threadibly engaged with stud 248.
  • a manually adjustible focusing wheel. 252 the topmost periphery of which extends through the cover of exposure control housing 16 to permit operator access thereto. Focusing wheel 252 is mounted for rotation upon the collar of a screw 254 extending therethrough and into rear casting 158.
  • solenoid 240 is configured having an excitation winding 256 mounted upon a bobbin 258 which, in turn, is supported upon a U-shaped frame or bracket 260.
  • Frame v260 is fixed to rear casting 158 in a manner positioning solenoid 240 behind focus wheel 252 and above solenoid 172.
  • the follow focus components of mechanism 66 position an interceptor linkage 262 at a location whereat a cam surface 264 formed thereupon may arrest the opening movement of blades 140 and 142 at a position defining a proper aperture value.
  • Linkage 262 is pivotally connected by an axle 266 through inwardly depending flanges of a cam follower 268.
  • a slot 270 formed within follower 268 provides for the slidable To move cam surface 264 of interceptor linkage 262 into an intercepting or arresting position, linkage 262 is driven inwardly such that surface 264 is positioned to intercept a pin 276 extending from walking beam 154. Note that pin 276 is formed having an annular shaped flange portion 276 at its outer tip. An intercepting orientation for linkage 262 is depicted in FIG. 7, while a standby or non-intercepting orientation for linkage 262 is illustrated in FIG. 6. Linkage 262 is biased into the latter orientation by a plunger 280 extending from a portion of rear casting 158. Outward bias is imparted to plunger 280 by a compression spring 282.
  • the noted bias exerted from plunger 280 is applied against the inner face of an arm-type extension 284 of linkage 262. Contact with the opposite face of arm 284 is provided by a pull-down bar 286. Pull-down bar 286 is loosely pinned to an extension 288 of frame 260 by a rivet 290. Bar 286 also is pivotally coupled to the internally disposed plunger 292 of solenoid 240 by a connector 294. Thus configured, when the excitation winding 296 of solenoid 240 is energized, plunger 292 is retracted therewithin to draw pull-down bar 286 inwardly and, in turn, urge linkage 262 inwardly against the bias of spring 282.
  • .142 commence to define progressively enlargening aperture widths until such time as pin 276 of walking beam 154 is captured by contact with camming edge 264 of interceptorlinkage 262. The latter capture .as well as a delay feature suspending further operational events within the exposure phase is indicated at function block 300.
  • contact bar 190 of switch S moves into contact with conductive surface 194..As noted at block 302, this switching activity energizes the flash firing circuit of the system, however, the system is not committed to a flash mode cycle at this point. Accordingly, the light responsive regulation function described in connection with block 218 continues to operate in normal fashion.
  • solenoid 240 is de-energized,'as shown at block 304. No exposure mechanism blade movement ensues, inasmuch as the outer flange portion 278 of pin 276, operating in conjunction with the bias exerted from spring 182, maintains the interceptor link 262 at its arrested orientation.
  • solenoid 240 is deenergized as described at 304, a pulse is generated which is utilized to actuate the flash firing circuit of the system to ignite a select flashlamp as indicated at block 306. Only when such a flashlamp has been successfully ignited is the light responsive regulation operation of the system, as described at block 218, suppressed. Such suppression is depicted at block 308.
  • a fixed delay as depicted at 310, ensues to establish an exposure interval corresponding with the light generation time of the fired flashlamp.
  • a trigger is fired, as described at 220, to energize solenoid 172 to close blades 140 and 142.
  • pin 192 within solenoid plunger 180 again transfers contact rod 190 of switch S, into contact with conducting surface 192. This activity serves to de-energize the flash firing circuit as depicted at function block 312.
  • the latter activity at switch S also serves to energize motor 70 to commence the post exposure phase of the photographic cycle, as shown at function block 224.
  • the post exposure phase of the flash mode cycle continues with the same sequence of operational events as performed under ambient mode conditions. These events are discussed above in connection with function blocks 224 through 232.
  • FIGS. 8 and following a schematic diagram for a control circuit suited to regulate the instrumentalities heretofore disclosed is provided.
  • Truth tables and related energization state diagrams also are provided for purposes of graphically illustrating the performance of components within the circuit.
  • the circuit of FIG. 8 includes a series of multi-function GATES designated A-E.
  • the inputs and outputs for these GATES are depicted in Boolean enumeration in the noted truth-tables.
  • the tabulations within these figures, as well as to facilitate the description to follow when the inputs or outputs of the listed components are at ground reference potential, they are referred to as low and, additionally, such input or output may be digitally identified as 0.
  • FIGS. 8, 9 and 10 the circuit arrangement for controlling camera 10 under ambient lighting conditions is illustrated.
  • a photographic cycle is commenced with the depression of start button 208. This depression serves to close a switch designated as S in FIG. 8.
  • Closure of switch S connects a primary power line 338 which is connected with the positive terminal'of a battery 340.
  • the opposite terminal of battery 340 is connected by a line 342 to ground.
  • primarypower line 338 serves .to energize a latching network depicted functionally by block 344.
  • network 344 operates under two energization states. The first of these states permits the operator of camera 10 to abort a photographic cycleuntil such time as switch S is opened, as discussed in connection with function block 212 of FIG. 4. Following the opening of switch S a second energization state at network 344 permits a continuous powering of the circuit from line 345, even though the contacts of switch S, are separated.
  • the output of latching network 344 is present at a power distribution line 346 which, in turn, is connected to a branch power line 348.
  • Branch power line 348 is connected to a second branch power line 350 and these two lines serve to power and assert initial control conditions over the various gates and components within the entire circuit.
  • a Schmitt-type having a normally conducting output state and a normally non-conducting input state. These states operate to reverse their conductive states very rapidly upon receipt at the input stage of a signal which is at least equal to a predetermined triggering reference or threshold level.
  • a signal which is at least equal to a predetermined triggering reference or threshold level.
  • the output at line 356 of trigger 358 remains low until a signal above the noted triggering reference level is received at any of its input lines, for instance, at line 366.
  • the output at line 356 assumes a high status.
  • Such input as derived at line 366, is developed from a control signal generated at a light-sensitive exposure control network designated generally at 368.
  • Gate input terminal b of GATE A evidences a low state by virtue of its connection through line 370 and limiting resistor 372 to ground. Additionally, this low status is permitted as a result of the connection of line 370 through lines 374, 376 and 378 to switch 5,.
  • Switch S corresponds with that described in conjunction with the earlier figures and is shown havinga common terminal c contact rod and alternate contacts A and B.
  • switch 5. assumes c'ondition C-A, it is considered to be in position wherein contact rod 190 is in contact with conducting surface 194, as discussed in connection with FIGS. 3 and 5.
  • switch 8. assumes condition C-B," it is considered to be in the orientation described in the noted figures wherein contact rod 190 is in contact with conducting surface 192.
  • switch S is normally in a GA condition at the commencement of a photographic cycle
  • line 378 is open-circuited.
  • switch 5 assumes a C-B condition
  • line 378 is energized through line 364 from primary power line 338.
  • Gate input terminal c of GATE A is coupled through line 380 and line 382 to the corresponding common input terminals of GATE B.
  • the initial low status of common input terminals 0 is derived as a result of the connection of line 382 through line 384 to the output 386 of a trigger 388.
  • the output of trigger 388 is normally low and will assume a high status in response to the receipt of a signal above a predetermined triggering or threshold value at its input 390.
  • Trigger 388 is energized from branch power line 350 through line 392 and is coupled to ground through lines 394 and 396. Representing the triggering components of the delay function described in connection with function block 214 of FIG. 4, trigger 388 serves to retain common input terminals c at a low state during the pre-exposure phase of a photographic cycle. Note that this low input condition represents a signal from the electrical-mechanical interface of the control system that reflex component has not been elevated to a position proximate that required for initiating the exposure phase of a photographic cycle.
  • the resultant initial output, t, of GATE A present at line 398 is high and is imposed at the base of an NPN transistor Q
  • the emitter of transistor 0 is coupled along line 400 to ground while its collector is connected to line 402.
  • Line 402 in turn, connects the excitation winding 174 of solenoid 172 to primary power line 338.
  • the high status at line 398 serves to forward bias the base-emitter junction of transistor 0,,
  • GATE B serves apowering down function wherein solenoid 172 is energized at a lower current level when the plunger 180 thereof gains its fully retracted position. To carry this out, GATE B diverts solenoid energizing current through limiting resistor 404. When transistor is forward biased, however, this diversion through resistor 404 is insignificant.
  • Solenoid 172 being energized, blades 140 and 142 are driven to their fully closed position. When this position is reached, contact rod 190 of switch S, will have been transferred to derive a GE condition.
  • Line 410 is coupled to line 354, the latter line providing a common coupling of the corresponding inputs of GA TES A and B.
  • Gate input terminal d of GATE C remains low in consequence of its connection through lines 412, 414 and closed switch S to ground.
  • input tenninal b of GATE C is connectable to primary power line 338 from lines 364, 378 and switch 8., when in a C-B condition, its status is now altered from a low to a high" state.
  • the resultant low output i of GATE C when introduced through line 408, signals a motor control function 416 to energize motor 70.
  • Control function 416 is energized from primary power line 338 through line 418 and is coupled to ground through line 420.
  • the resultant energization of motor 70 effects the release or unlatching of reflex component 50, thereby enabling a spring drive mechanism to move it away from its viewing position.
  • tab 90 of ram 80 moving in corresponding synchronism with reflex component 50, releases from engagement with insulative cap 92 of leaf 94 to open switch S
  • the opening of switch S alters the status of input terminal d of GATE C to a high" condition and the resultant outputs t of the GATE becomes high.
  • a high status at line 408 serves to signal motor control function 416 to de-energize motor 70. As a consequence, drive to gear train 72 is halted.
  • switch S The opening of switch S and resultant alteration of the status of input terminal d serves to signal latching network 344 to assume its second energization state, thereby committing the control system to the completion of photographic cycle.
  • Connection between input line 412 and network 344 is made through resistor 422, line 424 and line 426.
  • network 430 serves to delay the commencement of the exposure phase of a photographic cycle. This delay is selected in accordance with a time constant sufficient to permit reflex component 50 to fully seat at its exposure position.
  • Network 430 is activated upon removal of a shunt about capacitor 434 which is constituted by a line 438, connected from a point intermediate capacitor 434 and resistor 432, to ground through a diode 440 and switch S Diode 440 serves to isolate line 438 from spurious signals and the like.
  • a threshold signal is developed at input 390 of trigger 388.
  • trigger 388 alters its output at line 386 to a high status.
  • This high status is introduced from line 384 to lines 380 and 382 to simultaneously alter the state of all common gate inputs 0 to d high or 1 status.
  • Such alteration changes the output t of GATE B to high state, thereby abruptly terminating current flow in line 402, with the consequence of deenergizing excitation winding 174 of solenoid 172.
  • the exposure phase of a photographic cycle begins as blades and 143 of exposure mechanism 66 commence to open under the bias of opening spring 182.
  • the signal change in line 382 also is introduced through an inverter 442 to activate an electronic switch shown functionally by block 444.
  • an electronic switch shown functionally by block 444 Described in detail and claimed in a copending application for United States patent by E. K. Shenk, Ser. No. 213, 289, tiled Dec. 20, 1971, entitled, Exposure Control System Incorporation Solid State Switching to Enable a Light-Sensitive Network, and-assigned in common herewith, when triggered, switch 444 removes a shunt established by lines 446 and 448 across a timing capacitor 450. The removal of this shunt activates exposure control network 368, thereby providing the light-responsive regulation function described in connection with block 218 of FIG. 4 and represented as Event No. 5 in FIGS. 9 and 10.
  • Network 368 includes a photovoltaic cell 452, positioned within camera behind openings 148 and 150 of exposure mechanism 66 and connected to the input of an operational, differential-type amplifier 454 by lines 456 and 458.
  • Timing capacitor 450 is coupled within a feedback path between output 460 of amplifier 454 and its input at line 456.
  • the output of this light-sensing arrangement at line 460 represents an integrated valuation of scene lighting as witnessed at the optical path of camera 10. This output is varied in accordance with the sensitrometic properites properties of film being exposed by a second amplification stage 462.
  • Amplification stage 462 operates in conjunction with a gain adjusting variable resistor 464 and a calibrating resistor 466, the latter being positioned within a feedback path line 468.
  • Power supplies forboth amplifier 454 and 462 are provided from branch power line 348 and line470, while ground connections for the amplifiers, respectively, are provided through lines 472 and 474.
  • the adjusted output from network 368 is presented alongline 366 to trigger 358.
  • Solenoid 172 then operates to block the optical path of camera 10 by closing blades I40 and 142. As plunger 180 of solenoid 172 .reaches its fully-retracted position, pin 192 extendingtherefrom moves contact rod 190 to alter switch S to a .C-B condition. The exposure phase of the photographic cycle is terminated.
  • pick assembly 120 is actuated to draw a photographic unit 20 as at '34 from cassette 32 and move its forward edge into the bite of rotating processing rolls and 112 to process the unit and drive it out of the receiving chamber of camera 10. Such activity is depicted in FIG. 1.
  • switch S When closed to terminate a photographic cycle, switch S also imposes a quenching signal upon latching function 344 from along lines 414, 412, 424 and 426. As a consequence, the entire circuit is de-energized thereby permitting the de-energization of excitation winding 174 of solenoid 172. The latter de-energization is carried out if switch S is open and level to permit exposure mechanism blades and 142 to be driven under the biasof spring 136 to their fully opened positions in preparation for a next succeeding photographic cycle. As plunger of solenoid 172 commences its outward movement, rod of switch S is released to permit the switch to assume its C-A condition.
  • CONTROL CIRCUIT FLASH MODE CYCLE The control system of camera 10 converts to a follow-focus-type flash operation when a flash array such as that depicted at 234 in FIG. 1 is mounted upon exposure housing 16. As described in connection with function block 236 of FIG. 4, when somounted, a switch S connected within line 424 is closed (FIG. B). Referring additionally to FIGS.'11 and 12, it may be seen that, at the commencement of a photographic cycle under flash mode operation, Event No. 1 remains the same as operation under ambient conditions. Accordingly, input conditions are imposed upon GATES A and B to effect the energization of excitation winding 174 of solenoid 172. As noted at function block 210 of FIG.
  • blades 140 and 142 of exposure mechanism 66 are driven to a blocking terminal position and switch S remained in a GA condition wherein a flash sequencing and firing circuit 476 was energized from primary power line 338, line 364 and line 478.
  • Ground connection for circuit 476 is provided through line 480.
  • Firing circuit 476 is operative to sequentially ignite the individual flashlamps within linear flashlamp arrays as shown at 234 in FIG. 1. Typical of such circuits is one described in a US. Pat. No. 3,618,492, by S. Ellin. Such circuits are necessarily involved and if not appropriately isolated, may be prone to cause spurious flashlamp ignitions in the presence'of excessive electrical noise. Such noise may be present in automaticcameras

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US00333331A 1972-04-24 1973-02-16 Flash photographic control system Expired - Lifetime US3820128A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US00333331A US3820128A (en) 1972-04-24 1973-02-16 Flash photographic control system
GB1796673A GB1391293A (en) 1972-04-24 1973-04-13 Photographic exposure control apparatus
CA169,112A CA998865A (en) 1972-04-24 1973-04-19 Photographic control system for flash and ambient light modes
FR7314655A FR2226075A5 (ru) 1972-04-24 1973-04-20
JP4605573A JPS5716336B2 (ru) 1972-04-24 1973-04-23
DE2320676A DE2320676C2 (de) 1972-04-24 1973-04-24 Belichtungssteuereinrichtung für fotografische Apparate
CA223,863A CA999176A (en) 1972-04-24 1975-04-04 Photographic flash and ambient exposure control system

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US24689172A 1972-04-24 1972-04-24
US00333331A US3820128A (en) 1972-04-24 1973-02-16 Flash photographic control system

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3896459A (en) * 1974-05-29 1975-07-22 Honeywell Inc Control circuit for an automatic photographic camera
US4005449A (en) * 1973-12-13 1977-01-25 Polaroid Corporation Flash photographic system with camera inhibit feature
US4017876A (en) * 1976-01-13 1977-04-12 Polaroid Corporation Shutter latch system with automatic release for shock damping member
US4023187A (en) * 1975-10-03 1977-05-10 Polaroid Corporation Exposure control system with fill flash race condition
FR2338507A1 (fr) * 1976-01-13 1977-08-12 Polaroid Corp Appareil de prise de vues muni d'un verrouillage d'obturateur perfectionne
US4182561A (en) * 1978-08-03 1980-01-08 Polaroid Corporation Fast charging electronic flash device
US4184756A (en) * 1978-10-13 1980-01-22 Polaroid Corporation Strobe without primary storage capacitor
US4185144A (en) * 1978-09-05 1980-01-22 Polaroid Corporation Electrochemical cell with a cadmium patch electrode
US4291964A (en) * 1980-01-28 1981-09-29 Polaroid Corporation Strobe switch with camera control feature

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4017873A (en) * 1975-10-03 1977-04-12 Polaroid Corporation Exposure control system with braking capability
US4008481A (en) * 1975-10-03 1977-02-15 Polaroid Corporation Exposure control system with separate flash and ambient trigger levels

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4005449A (en) * 1973-12-13 1977-01-25 Polaroid Corporation Flash photographic system with camera inhibit feature
US3896459A (en) * 1974-05-29 1975-07-22 Honeywell Inc Control circuit for an automatic photographic camera
US4023187A (en) * 1975-10-03 1977-05-10 Polaroid Corporation Exposure control system with fill flash race condition
US4017876A (en) * 1976-01-13 1977-04-12 Polaroid Corporation Shutter latch system with automatic release for shock damping member
FR2338507A1 (fr) * 1976-01-13 1977-08-12 Polaroid Corp Appareil de prise de vues muni d'un verrouillage d'obturateur perfectionne
FR2338508A1 (fr) * 1976-01-13 1977-08-12 Polaroid Corp Appareil de prise de vues muni d'un verrouillage d'obturateur perfectionne
US4182561A (en) * 1978-08-03 1980-01-08 Polaroid Corporation Fast charging electronic flash device
JPS5522795A (en) * 1978-08-03 1980-02-18 Polaroid Corp Electronic flash device and camera using same
US4185144A (en) * 1978-09-05 1980-01-22 Polaroid Corporation Electrochemical cell with a cadmium patch electrode
US4184756A (en) * 1978-10-13 1980-01-22 Polaroid Corporation Strobe without primary storage capacitor
EP0010884A1 (en) * 1978-10-13 1980-05-14 Polaroid Corporation Electronic flash device
US4291964A (en) * 1980-01-28 1981-09-29 Polaroid Corporation Strobe switch with camera control feature

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GB1391293A (en) 1975-04-23

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