Miniaturized optical zoom lens system
AssigneeNational University of Singapore
InventorsGuangya Zhou, Hongbin Yu, Fook Siong Chau
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Abstract
The present application provides a micromechanical (MEMS) based zoom lens system, for use in miniature device applications, such as miniature electronic imaging devices. The MEMS-based zoom lens system comprises at least four optical elements, or two Alvarez or Lohmann lenses, that are configured for passage of optical signals therethrough along an optical signal path. Each optical element is MEMS-driven and displaceable in a direction substantially transverse to the optical signal path. In use, the transverse displacement of the optical elements vary an overall focal length of the MEMS zoom lens system such as to provide an optical zoom function. A method of manufacturing a MEMS zoom lens system is also provided in a further aspect.
Claims30
An optical zoom lens system comprising
- at least two microactuators configured to displace one or more optical elements,
- at least four optical elements, each of the at least four optical elements configured for passage of optical signals therethrough along an optical signal travel path, each of the at least four optical elements comprising at least one free-form surface,
- wherein at least four of the optical elements are positioned in a pair-wise configuration such that a first and a second optical element form a first pair and a third and a fourth optical element form a second pair, each of the pairs displaceable, in response to the at least two microactuators, in a direction substantially transverse to the optical signal path to cause a change in optical power of the system.
An optical zoom lens system comprising
- at least one movable microstructure configured to displace one or more optical elements,
- at least four optical elements, each of the at least four optical elements configured for passage of optical signals therethrough along an optical signal travel path, each of the at least four optical elements comprising at least one free-form surface,
- wherein at least four of the optical elements are positioned in a pair-wise configuration such that a first and a second optical element form a first pair and a third and a fourth optical element form a second pair, each of the pairs displaceable by the at least one movable microstructure in a direction substantially transverse to the optical signal path to cause a change in optical power and focus of the system, and
- wherein a separation distance, measured from a forward surface of the optical element which first receives the optical signals to a back surface of the optical element from which the optical signals exit, is approximately 30 mm or less.
An optical zoom system having an optical signal path for use in miniaturized cameras comprising
- at least one varifocal lens structure, the varifocal lens structure having at least one free-form surface,
- at least one flexure suspension having first and second ends, the first end connected in a fixed position and the second end connected to at least a portion of the at least one varifocal lens structure for applying a force thereagainst,
- at least one miniaturized actuator for applying a force on at least a portion of the at least one varifocal lens structure in opposition to the force applied by the flexure suspension to move at least a portion of the at least, one varifocal lens structure substantially transverse to the optical signal path.
The optical zoom system of cairn 1 further comprising a fixed focal length lens.
The optical zoom system of cairn 16 wherein the fixed focal length lens contributes to the optical power of the system.
An optical zoom system comprising
- an entry window aligned along an optical signal path,
- a prism for folding the optical signal path approximately 90 degrees relative to the entry window,
- a first pair of varifocal optical elements aligned along the optical signal path and configured to be laterally displaced relative to one another to vary focal length of the first pair,
- a second pair of varifocal optical elements aligned along the optical signal path and configured to be laterally displaced relative In one another In vary focal length of the second pair,
- a plurality of actuators for causing lateral displacement of the first and second pairs such that the combination of the displacements of the optical elements of the first and second pairs provides an optical magnification at the plane of a sensor,
- at least one lens element between the second pair and the plane of the sensor for providing at least some aberration compensation, and
- wherein a separation distance, measured from a forward surface of the optical element which is first in the optical signal path to a back surface of the optical element which is last in the optical signal path, is approximately 30 mm or less.
Dependencies are inferred from the claim text.