Exposure control device for camera

Claim 2

An exposure control device for a camera of the type including a shutter release mechanism comprising a. an electric circuit including a photoelectric element and switch means b. a base plate provided with an arcuate slot, c. an exposure meter mounted on said base plate and connected in said electric circuit whereby said meter is actuable in response to the variation in resistance of said photoelectric element, d. a pointer of said exposure meter being adapted to swing above said base plate, said pointer having the leading end thereof being so bent as to extend upwardly through said arcuate slot from an undersurface of said base plate, and having an indicating pointer which is extended in the axial direction of said first mentioned pointer for indication of an exposure condition, e. a detecting lever mounted to slide toward the leading end of said pointer above said base plate in response to operation of said shutter release mechanism in such a manner that when the brightness of a subject is sufficient said detecting lever engages with said leading end of said pointer and is stopped thereby and when the brightness of a subject is not sufficient, said detecting lever is further displaced to a full stroke displacement to control said switch, f. a pointer retaining plate provided with means for pressing said pointer to retain it in a position to which said pointer swings, and means responsive to the position of said pointer for setting the exposure conditions in said camera, and g. means in said circuit responsive to the control of said switch means for switching an exposure condition in said camera.

Claim 3

An exposure control device as set forth in claim 1 wherein saId exposure setting means comprises a. a cam formed on the surface of said retaining plate which makes contact with said pointer, b. a stop interlocking lever coupled to the retaining plate to have a position determined in response to the position of said retaining plate, and c. stop diaphragms actuable in response to said interlocking lever to set a stop.

Claim 4

An exposure control device as set forth in claim 1 wherein said exposure setting means comprises a. a movable contact fixed to said pointer, b. a meter scale plate and a plurality of stationary contacts for contact with said movable contact disposed upon said meter scale plate, c. a plurality of resistors each of which is interconnected between the adjacent contacts of said stationary contacts, d. capacitors which constitute time-constant circuits, and e. a shutter mechanism actuating a switching circuit responsive to the time-constant of said time-constant circuit.

Claim 5

An exposure control device as set forth in claim 1 wherein said means for switching said exposure condition comprises at least a. a variable resistor and a switch for selectively connecting either said photoelectric element or said variable resistor to said meter, b. a circuit for triggering a flash cube including a switch for closing the triggering circuit, both of said switches being actuable in response to said further displacement of said detecting lever.

Claim 6

An exposure control device as set forth in claim 3 wherein said means for switching said exposure condition comprises a. a by-pass circuit for said exposure meter and a first switch connected to open and close said by-pass circuit b. a second switch connected to be actuated simultaneously with said first switch to vary the capacitance of said capacitors in said time constant circuit, thereby varying the time constant of said time constant circuit, both of said first and second switches being actuable in response to the full stroke displacement of said detecting lever.

Claim 7

An exposure control device as set forth in claim 1 comprising a scale plate having two scale ranges and means for selectively displaying said exposure condition on said scale plate in either of said two ranges.

Claim 8

An exposure control device as set forth in claim 6 comprising means for displacing said scale plate in response to said full stroke displacement of said detecting lever.

Claim 9

In an EE camera having a built-in flash cube, and a shutter release mechanism, an exposure control device comprising an exposure meter having a pointer with a portion adjacent to its free end bent in the form of a U, a detecting lever positioned to be displaced toward the free end of said pointer in response to operation of said shutter mechanism, switching means positioned to be actuable in response to the displacement of said detecting lever, an electric circuit including a variable resistor and an EE photoelectric element, said switch means being connected to substitute said resistor for said element, said circuit being connected to said exposure meter, said resistor having a resistance depending upon a guide number of the flash cube and a film-to-subject distance, a flash cube triggering circuit connected to be energized when said switch means is closed, a rotatable cam plate positioned to press down said pointer in response to operation of said shutter release mechanism after said detecting lever has been actuated, thereby moving said leading end of said pointer away from the path of said detecting lever, the detecting arm of said detecting lever being mounted to engage the free end of said pointer when the brightness of a subject is within the EE range, so that the movement of said detecting lever is limited and said switch means are held in inoperative positions, said detecting arm of said detecting lever being positioned so that it cannot engage said free end of said pointer when the brightness of a subject is so dark as to be out of an EE range so that saiD detecting lever may displace a greater stroke beyond the path of said free end of said pointer, thereby permitting the movement thereof to actuate said switch means to substitute said variable resistor for said EE photoelectric element so as to cause said pointer through an angle which is determined depending upon the resistance of said variable resistor, and to close said switch means to establish the flash cube triggering circuit, and means for rotating said cam plate to engage said pointer immediately after said trigger circuit has been established thereby setting a stop in said camera, and means for then automatically triggering said flash cube in response to further control of said shutter release mechanism.

Claim 10

In an EE camera having a built-in flash cube, and a shutter release mechanism, an exposure control device comprising an exposure meter having a pointer with a portion adjacent to its free end bent in the form of a U, a detecting lever positioned to be displaced toward the free end of said pointer in response to operation of said shutter mechanism, switching means positioned to be actuable in response to the displacement of said detecting lever, an electric circuit including a variable resistor and an EE photoelectric element, said switch means being connected to substitute said resistor for said element, said circuit being connected to said exposure meter, said resistor having a resistance depending upon a guide number of the flash cube and a film-to-subject distance, a flash cube triggering circuit connected to be energized when said switch means is closed, a rotatable cam plate positioned to press down said pointer in response to operation of said shutter release mechanism after said detecting lever has been actuated, thereby moving said leading end of said pointer away from the path of said detecting lever, the detecting arm of said detecting lever being mounted to engage the free end of said pointer when the brightness of a subject is within the EE range, so that the movement of said detecting lever is limited and said switch means are held in inoperative positions, said detecting arm of said detecting lever being positioned so that it cannot engage said free end of said pointer when the brightness of a subject is so dark as to be out of an EE range so that saiD detecting lever may displace a greater stroke beyond the path of said free end of said pointer, thereby permitting the movement thereof to actuate said switch means to substitute said variable resistor for said EE photoelectric element so as to cause said pointer through an angle which is determined depending upon the resistance of said variable resistor, and to close said switch means to establish the flash cube triggering circuit, and means for rotating said cam plate to engage said pointer immediately after said trigger circuit has been established thereby setting a stop in said camera, and means for then automatically triggering said flash cube in response to further control of said shutter release mechanism.

Claim 11

In a camera of the type having a view finder, a shutter release mechanism and incorporating an electronic shutter circuit in which the resistance of a time constant circuit is varied in response to the angular displacement of a pointer of an exposure control meter, an exposure control device comprising a detecting lever mounted to have a smaller and greater displacement depending upon whether said detecting lever is engageable with the leading end of said pointer or not in response to the operation of said shutter release mechanism, a displaceable scale plate having a high and low shutter speed scales, and a group of resistors constituting said time constant circuit, a selection switch actuable in response to the displacement of said scale plate to select the range of said time constant circuit, a pointer retaining plate mounted to press down said pointer to make it selectively contact one of the resistors in said resistor group, said pointer being positioned to engage said detecting lever when an optimum shutter speed is in a high shutter speed range so that the displacement of said detecting lever is limited and said scale plate is held stationary whereby said high shutter speed scale can be viewed in the field of view of said viewfinder, said pointer being positioned to contact one of a plurality of resistor contacts connected to the junctions of said resistors respectively toward which said pointer is swung when said retaining plate presses down said pointer, thereby establishing a high shutter speed time constant circuit in said electronic shutter circuit, said pointer being positioned so that said detecting lever cannot engage it when an optimum shutter speed is in a low shutter speed range so that the detecting arm of said detecting lever may move beyond the path of said leading end of said pointer, and means for causing the displacement of said scale plate when the lever moves beyond said leading end to permit the low shutter speed scale to be viewed in the field of view of said viewfinder and to cause said selection switch to select a low shutter speed range to actuate said exposure control meter again, and means for thereafter moving said retaining plate to cause said pointer to make contact one of said resistor contacts, thereby establishing a low shutter speed time constant circuit in said electronic shutter circuit.

Claim 12

In a camera of the type having a view finder, a shutter release mechanism and incorporating an electronic shutter circuit in which the resistance of a time constant circuit is varied in response to the angular displacement of a pointer of an exposure control meter, an exposure control device comprising a detecting lever mounted to have a smaller and greater displacement depending upon whether said detecting lever is engageable with the leading end of said pointer or not in response to the operation of said shutter release mechanism, a displaceable scale plate having a high and low shutter speed scales, and a group of resistors constituting said time constant circuit, a selection switch actuable in response to the displacement of said scale plate to select the range of said time constant circuit, a pointer retaining plate mounted to press down said pointer to make it selectively contact one of the resistors in said resistor group, said pointer being positioned to engage said detecting lever when an optimum shutter speed is in a high shutter speed range so that the displacement of said detecting lever is limited and said scale plate is held stationary whereby said high shutter speed scale can be viewed in the field of view of said viewfinder, said pointer being positioned to contact one of a plurality of resistor contacts connected to the junctions of said resistors respectively toward which said pointer is swung when said retaining plate presses down said pointer, thereby establishing a high shutter speed time constant circuit in said electronic shutter circuit, said pointer being positioned so that said detecting lever cannot engage it when an optimum shutter speed is in a low shutter speed range so that the detecting arm of said detecting lever may move beyond the path of said leading end of said pointer, and means for causing the displacement of said scale plate when the lever moves beyond said leading end to permit the low shutter speed scale to be viewed in the field of view of said viewfinder and to cause said selection switch to select a low shutter speed range to actuate said exposure control meter again, and means for thereafter moving said retaining plate to cause said pointer to make contact one of said resistor contacts, thereby establishing a low shutter speed time constant circuit in said electronic shutter circuit.

Claim 13

An exposure control device for a camera of the type having a exposure meter mounted on a plate and having a pointer positioned to move in a plane above said plate, and wherein the camera further includes shutter release means and exposure condition setting means, the improvement wherein said plate has a slot, said pointer having an extension bent so that said extension extends downwardly from said pointer and has a leading edge extending upwardly through said slot for meeting said plate, said extension further having an indicating pointer for indicating an exposure condition corresponding to the brightness of a scene, said indicating pointer extending substantially in a longitudinal direction of said first mentioned pointer, said control device further comprising: a. a slidable detecting lever having a leading edge positioned to engage said leading end in a first given range of angular positions of said pointer correspoNding to adequate brightness for operation of the camera with a given exposure setting, and to miss said leading end at another angular position of said pointer corresponding to inadequate brightness to operate the camera at said given exposure setting, upon movement of said lever in one direction, b. means responsive to operation of said shutter release means for moving said lever in said one direction, whereby said lever is stopped by said leading end at a first position when said brightness is adequate to operate the camera and is permitted to move to a second position when said brightness is inadequate to operate the camera, c. a pointer retaining plate and means responsive to operation of said shutter release means for urging said pointer retaining plate against said pointer for holding said pointer against further movement, and d. an electric circuit including a photo cell connected to said exposure meter, said circuit including switch means operable by said lever in said second position to change a parameter of said electric circuit, whereby when said switch means is operated the response of said exposure meter is varied.

Claim 14

An exposure control device for a camera of the type having a exposure meter mounted on a plate and having a pointer positioned to move in a plane above said plate, and wherein the camera further includes shutter release means and exposure condition setting means, the improvement wherein said plate has a slot, said pointer having an extension bent so that said extension extends downwardly from said pointer and has a leading edge extending upwardly through said slot for meeting said plate, said extension further having an indicating pointer for indicating an exposure condition corresponding to the brightness of a scene, said indicating pointer extending substantially in a longitudinal direction of said first mentioned pointer, said control device further comprising: a. a slidable detecting lever having a leading edge positioned to engage said leading end in a first given range of angular positions of said pointer correspoNding to adequate brightness for operation of the camera with a given exposure setting, and to miss said leading end at another angular position of said pointer corresponding to inadequate brightness to operate the camera at said given exposure setting, upon movement of said lever in one direction, b. means responsive to operation of said shutter release means for moving said lever in said one direction, whereby said lever is stopped by said leading end at a first position when said brightness is adequate to operate the camera and is permitted to move to a second position when said brightness is inadequate to operate the camera, c. a pointer retaining plate and means responsive to operation of said shutter release means for urging said pointer retaining plate against said pointer for holding said pointer against further movement, and d. an electric circuit including a photo cell connected to said exposure meter, said circuit including switch means operable by said lever in said second position to change a parameter of said electric circuit, whereby when said switch means is operated the response of said exposure meter is varied.

Claim 15

The exposure meter of claim 10 for use in a camera system including flash means, wherein said electric circuit comprises resistor means, and said switch means comprises means for substituting said resistor means for said photoelectric cell in said circuit in said second position of said detecting lever, said resistor means having a resistance corresponding to the guide number of the flash means and a film-to-subject distance.

Claim 16

The exposure meter of claim 11 in which said exposure condition setting means is a diaphragm setting means, wherein said pointer retaining plate comprises a stepped lever having a displacement dependent upon the position of said pointer, comprising means coupling said lever to said diaphragm setting means.

Claim 17

The exposure meter of claim 10 in which said exposure condition setting means is a shutter control means, wherein said electric circuit comprises means for operating said shutter control means, time constant circuit means, and means responsive to operation of said switch means for changing a time constant in the time constant circuit means for controlling the time of operation of said shutter control means.

Claim 18

The exposure meter of claim 13 wherein said time constant means comprises a plurality of speed electric contacts interconnected by resistor means, said contacts being positioned to be selectively electrically connected to said pointer when said pointer is urged by said pointer retaining plate.