Focal plane shutter and method for forming the same
AssigneeNikon Corporation
InventorsTakashi Matsubara, Masanori Hasuda
Life of this patent
Estimating the term…
Abstract
A focal plane shutter provides an extremely durable and reliable super-high speed shutter with speeds of greater than 1/8000 second which minimizes increases in the charge energy, has an increased rate of acceptance of the FRP and is economical to produce. The blades will not collide with or be damaged by the intermediate plate and the light shielding plate, even when the shutter is released while accelerating the camera in a direction virtually perpendicular to the direction of movement of the blades. The focal plane shutter includes a front and a rear blind that each include multiple dividing blades. The rigidity of the slit-forming blades having the largest amount of movement among the dividing blades differs between the front blind and the rear blind.
Claims39
A focal plane shutter comprising:
- a front blind and a rear blind each having a plurality of blades;
- a driving mechanism that moves the front blind and the rear blind between an open position in which an exposure aperture is formed and a closed position in which the exposure aperture is covered;
- at least one of said blades of the front blind having a larger range of movement than the other blades of the front blind;
- and
- at least one of said blades of the rear blind having a larger range of movement than the other blades of the rear blind;
- wherein a blade having a largest range of movement of the rear blind has greater rigidity than a blade having a largest range of movement of the front blind, and wherein a thickness of the blade having a second largest amount of movement in the front blind is substantially equal to a thickness of the blade having the largest amount of movement in the front blind, and further wherein a thickness of a blade having a second largest amount of movement in the rear blind is thinner than the blade having the largest amount of movement in the rear blind.
A focal plane shutter comprising:
- a front blind having a plurality of front dividing blades;
- a rear blind having a plurality of rear dividing blades;
- a mechanism for displacing the front and rear dividing blades to selectively define an exposure gap between at least one front slit-forming blade of said front blind and at least one rear slit-forming blade of said rear blind,
- wherein a rigidity of the rear slit-forming blade is different from a rigidity of the front slit-forming blade;
- and
- wherein thicknesses of two of said front dividing blades most displaced by said mechanism are substantially equal, and thicknesses of two of said rear dividing blades most displaced by said mechanism are different.
A focal plane shutter comprising:
- a front blind and a rear blind each having multiple dividing blades including a slit-forming blade, wherein the slit-forming blade of the front blind and the rear blind are movable with respect to each other to form a slit of a determined width between the front blind and the rear blind;
- and
- a driving mechanism that drives said front blind and said rear blind, wherein each slit-forming blade has a rigidity and the respective rigidities of the slit-forming blades of said front blind and said rear blind are different.
A focal plane shutter assembly comprising:
- a base plate;
- a front blind movably connected to said base plate, said front blind having a front slit-forming blade;
- and
- a rear blind movably connected to said base plate, said rear blind having a rear slit-forming blade cooperable with said front slit-forming blade to establish an exposure slit therebetween;
- wherein said front slit-forming blade and said rear slit-forming blade have different rigidities.
A method for forming a focal plane shutter of a camera having a front blind and a rear blind, each blind having a slit-forming blade and a plurality of dividing blades, said slit-forming blades being movable with respect to each other to form a slit of a predetermined width between the front and rear blinds, said method comprising:
- selecting material for each of the blades according to each blade's relative degree of movement;
- dimensioning the blades to reduce the possibility of collisions among the blades and with other components of the camera by dimensioning the front slit-forming blade to have a thickness that is less than a thickness of the rear slit-forming blade;
- and
- forming the blades using the selected material and dimensions.
A method for forming a focal plane shutter of a camera having a front blind and a rear blind, each blind having a slit-forming blade and a plurality of dividing blades, said slit-forming blades being movable with respect to each other to form a slit of a predetermined width between the front and rear blinds, said method comprising:
- selecting material for each of the blades according to each blade's relative degree of movement;
- dimensioning the blades to reduce the possibility of collisions among the blades and with other components of the camera;
- and
- forming a blade having a largest amount of movement of the rear blind with greater rigidity than a blade having a largest amount of movement of the front blind.
Dependencies are inferred from the claim text.