Control system for varifocal objective
AssigneeJos. Schneider Optische Werke GmbH
InventorOtto Thomas
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Abstract
The correlated positions of two axially shiftable components of a varifocal objective, i.e., a variator and a compensator, throughout a zoom range are stored in a memory from which they can be read out to control respective drives during a zooming operation. The readout rate is determined by a speed selector which sets a frequency for the pulsing of a control unit that scans successive memory addresses. The memory may also contain data for focusing control, either through axial adjustment of a front component of the objective or through modification of the positional correlation of the two shiftable components, as well as for an adjustment of a diaphragm with changes in the overall focal length.
Claims10
In an optical zooming system wherein a varifocal objective has a plurality of components including an axially shiftable variator for changing its focal length and an axially shiftable compensator for maintaining a constant image plane, the combination therewith of:
- first drive means for axially shifting said variator;
- second drive means for axially shifting said compensator;
- memory means storing correlated positional data for said variator and said compensator;
- a source of zooming signals;
- and
- control means connected to said memory means and to said source for concurrently reading out respective sequences of said correlated positional data to said first and second drive means in response to said zooming signals whereby said variator and said compensator are axially shifted between different positions in a zoom range.
Dependencies are inferred from the claim text.