Invention Grant
US5432574A Single lens reflex camera with collapsible lens 失效
单镜头反光相机与可折叠镜头

Single lens reflex camera with collapsible lens
Abstract:
A single-collapsible-lens reflex camera includes a lens barrel designed such that it is moved forward into shooting position from the camera body when in use and at least its part is collapsed in the camera body when not in use. A shutter release button is provided to shoot a subject when pressed. Electromagnets for controlling the leading and following curtains of a focal plane shutter are deenergized before the shutter release button is pressed and energized when the button is pressed. A mirror drive member raises or lowers a movable reflex mirror when a subject is shot and the lens barrel is collapsed. A shutter charging member moves the focal plan shutter in the direction that charges the focal plane shutter in synchronism with the operation of the mirror driving member to raise the mirror and in the direction that discharges the shutter in synchronism with the operation of the discharges driving member to raise the mirror. A control circuit deenergizes the shutter leading-curtain controlling electromagnet when the mirror is raised, deenergizes the shutter following-curtain electromagnet after a length of time depending on the intensity of light reflected from a subject to be photographed, and keeps the leading-curtain and following-curtain controlling electromagnets deenergized when the mirror is raised to collapse the lens barrel. Thereby, the shutter is shifted to the non-charged state as it is closed when the lens barrel is collapsed.
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