摘要:
An auto-focus system employing a tunable liquid crystal lens is provided that collects images at different optical power values as the liquid crystal molecules are excited between a ground state and a maximum optical power state tracking image focus scores. An image is acquired at a desired optical power value less than maximum optical power established with the liquid crystal molecules closer a fully excited state than the maximum optical power state having the same image focus score. This drive signal employed during image acquisition uses more power than was used to achieve the same optical power value during the auto-focus scan, while actively driving the liquid crystal molecules is fast. A pause due to image transfer/processing delays after acquisition is employed to allow slow relaxation of the liquid crystal molecules back to the ground state in preparation for a subsequent focus search.
摘要:
A liquid crystal optical device has a layered structure with split liquid crystal layers having alignment surfaces that define in a liquid crystal material pre-tilt angles of opposite signs. Four liquid crystal layers can provide two directions of linear polarization. In the case of a lens, the device can be a gradient index lens, and the alignment surfaces can have a spatially uniform pre-tilt.
摘要:
An auto-focus system employing a tunable liquid crystal lens is provided that collects images at different optical power values as the liquid crystal molecules are excited between a ground state and a maximum optical power state tracking image focus scores. An image is acquired at a desired optical power value less than maximum optical power established with the liquid crystal molecules closer a fully excited state than the maximum optical power state having the same image focus score. This drive signal employed during image acquisition uses more power than was used to achieve the same optical power value during the auto-focus scan, while actively driving the liquid crystal molecules is fast. A pause due to image transfer/processing delays after acquisition is employed to allow slow relaxation of the liquid crystal molecules back to the ground state in preparation for a subsequent focus search.
摘要:
An electromagnetic source has an electrode structure coupled to a substrate. The electrode structure has interspaced electrodes, at least one of which is spiral-shaped. At least one electrical contact interconnects the electrodes of the electrode structure. The electrode structure is responsive to an applied electrical current to generate a spatially non-uniform magnetic field. This field can act on a LC layer such that optical properties of the layer are controllable.
摘要:
A liquid crystal optical device is provided. The optical device includes a liquid crystal cell controlling optical properties of light passing therethrough and has: a liquid crystal layer, a planar electrode located to one side of said liquid crystal layer; an electric field control structure located to the opposite side of the liquid crystal layer; and a wavefront adjustment structure configured to provide optical phase front adjustment. In some embodiments the wavefront adjustment structure is a conductive floating electrode. In other embodiments the wavefront adjustment structure is a weakly conductive structure having spatially variable sheet resistance. In other embodiments the wavefront adjustment structure a weakly conductive structure having spatially variable sheet resistance having a frequency dependent characteristic.
摘要:
Variable liquid crystal devices for controlling the propagation of light through a liquid crystal layer use a frequency dependent material to dynamically reconfigure effective electrode structures in the device. The frequency of a drive signal that generates an electric field in the device may be varied, and the frequency dependent material has different charge mobilities for the different frequencies. At a low charge mobility, the frequency dependent material has little effect on the existing electrode structures. However, at a high charge mobility, the frequency dependent material appears as an extension of the fixed electrodes, and may be used to change the effective electrode structure and, thereby, the spatial profile of the electric field. This, in turn, changes the optical properties of the liquid crystal, thus allowing the optical device to be frequency controllable.
摘要:
Variable liquid crystal devices for controlling the propagation of light through a liquid crystal layer use a frequency dependent material to dynamically reconfigure effective electrode structures in the device. The frequency of a drive signal that generates an electric field in the device may be varied, and the frequency dependent material has different charge mobilities for the different frequencies. At a low charge mobility, the frequency dependent material has little effect on the existing electrode structures. However, at a high charge mobility, the frequency dependent material appears as an extension of the fixed electrodes, and may be used to change the effective electrode structure and, thereby, the spatial profile of the electric field. This, in turn, changes the optical properties of the liquid crystal, thus allowing the optical device to be frequency controllable.
摘要:
Methods and apparatus for testing operation of a single or multiple tunable active optical device(s) operated by one or more driving electrodes are described Test methods and apparatus are provided for device testing without necessarily requiring direct physical contact with the driving electrodes Testing subjects devices to incident light along an optical path and to an external electric field applied to the device producing a dipolar charge distribution within the electrodes, causing the device to operate The effect of device operation on incident light is optically sensed The sensed effect is analyzed to identify device defects Test methods and apparatus are provided for testing multiple unsingulated devices during fabrication employing a strip contact structure having contact strips connected to multiple devices and extending to wafer edges, such that singulating devices leaves portions of the strip contact structure exposed on device dice edges providing electrical contacts in use.
摘要:
Variable liquid crystal devices for controlling the propagation of light through a liquid crystal layer use a frequency dependent material to dynamically reconfigure effective electrode structures in the device. The frequency of a drive signal that generates an electric field in the device can be varied, and the frequency dependent material has different charge mobilities for the different frequencies. At a low charge mobility, the frequency dependent material has little effect on the existing electrode structures. However, at a high charge mobility, the frequency dependent material appears as an extension of the fixed electrodes, and can be used to change the effective electrode structure and, thereby, the spatial profile of the electric field. This, in turn, changes the optical properties of the liquid crystal, thus allowing the optical device to be frequency controllable.
摘要:
A variable optical device for controlling the propagation of light has a body of liquid crystal optical material with a center and a periphery, a heating system including an electrically controllable heat source and a thermal radiator arranged at the periphery for cooling a portion of the body of material. The heating system is operative to generate a spatially modulated temperature gradient and to provide a desired light propagation behavior.