| 摘要 |
A between-the-lens shutter which includes a sealed casing containing a liquid of selected index of refraction to couple two optical elements of the camera lens and which also houses a pair of shutter blades. The shutter blades are mounted to pivot about an axis offset with respect to an aperture through the casing and are controlled by a common cocking-releasing cam. The shutters are cocked sequentially and released simultaneously. A high shutter speed effect is achieved by allowing both shutter blades, when released to return simultaneously toward their normal or rest positions and a slow shutter speed effect is achieved by delaying the return of the second-cocked shutter blade when the two blades are released simultaneously. The delayed return is achieved by a latch made operative by slightly shifting the pivot mounting for the two shutter blades, the latch temporarily holding the second shutter blade in cocked position and being disengaged from this shutter blade in response to movement of the other shutter blade to its rest position after both blades have been simultaneously released by the cam.
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