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This paper describes how the maximum blur radius affects the depth results by depth from the defocus (DFD) method based on liquid crystal (LC) lens. Boundary frequency is determined by the maximum blur radius. It is found that if the maximum blur radius used in the calculation is larger than the real value, the depth resolution obtained is reduced; on the other hand, if one smaller than the real value is used, the depth resolution in the middle range of the scene is increased, but errors occur in the near and far planes. Using the maximum blur radius close to the real one results in the best depth results. [ABSTRACT FROM AUTHOR]

An imaging system is designed with a liquid crystal (LC) lens as the focusing element. The aperture of the LC lens plays the role of the aperture stop of the system. An entrance pupil larger than the LC lens aperture is realized and the magnification of the image formed by the system remains unchanged when the focal length of the LC lens is changed by the applied voltages. [ABSTRACT FROM AUTHOR]

Optical powers and RMS aberrations of the LC lens with different cell gap are studied. With increasing cell gap, the LC lens exhibits similar relation between the optical power and the driving voltage, and the RMS aberrations increase with optical power. The maximum optical power of the LC lens within the aberration level of 0.07 wave and the corresponding driving voltage are nearly proportional to the cell gap. [ABSTRACT FROM AUTHOR]

Liquid crystal lenses(LCL)of two liquid crystal(LC)layers with parallel and orthogonal optic axes are built. The LCL of two LC layers with parallel optic axes is designed to obtain larger focusing power, and that with orthogonal optic axes is to focus light wave of arbitrary polarizations. The focal lengths of both LCLs can be controlled by external voltages. [ABSTRACT FROM AUTHOR]

A new method of voltage application is proposed to increase the focus range of a liquid crystal lens driven by two voltages. It is possible for the optical power of the liquid crystal lens to change in a wider range, while the root mean square aberration of low level is maintained. The liquid crystal lens is driven by a frequency of the voltages different in positive and negative lens states to obtain its largest optical power in each state. An obvious increase in focus range is realised. [ABSTRACT FROM AUTHOR]

Transient properties of a liquid crystal (LC) lens are investigated. It is shown that the LC lens maintains its lens properties as it is driven to switch between positive and negative lens states. Its optical power changes from positive to negative values and rms aberration also changes with time but always keeps below 0.1 wavelength. This transient property of the LC lens is made use of to acquire image of extended depth of field. [ABSTRACT FROM AUTHOR]

We use a liquid crystal (LC) lens to create a foveated imaging system which contains a camera module as a main lens, an LC lens as a foveated device, and an image sensor. The principle and experimental results are given. The influences on imaging of the parameters, including the position and aperture of the LC lens, and the aperture of the lens module, etc, are discussed. [ABSTRACT FROM AUTHOR]