Abstract:
Liquid crystal (LC) beam control devices using a dispersion shaped (DS) half wave plate (HWP), with specific physical characteristics, allows the broadened beam to maintain significantly better the color cohesion. Beneficial aspects of using a HWP with an appropriate thickness and birefringence index which makes it inefficient in the blue wavelength spectrum, therefore reducing the blue photon depletion in the center of the broadened beam is described herein. Combinations of an homeotropic LC cell and DS HWP structures for reduced color separation, faster relaxation time and reduced ground state scattering is further described herein.
Abstract:
An autofocus camera assembly is described. The camera assembly includes an electrically controllable optical power lens and a lens assembly having a frame supporting at least one lens element near the electrically controllable optical power lens. The electrically controllable optical power lens is mounted to an object end of the frame. An aperture stop is provided located either at or within the electrically controllable optical power lens or on an external surface of the frame next to the electrically controllable optical power lens. The aperture stop can include an opaque mask and optionally alignment marks.
Abstract:
A liquid crystal optical device is provided. The optical device includes a layered structure including at least two support substrates. An external hole patterned control electrode is provided on one of the substrates and has an aperture. An internal hole patterned control electrode is provided on one of the substrates within the aperture, the internal control electrode and the outer control electrode being separated by a gap. The gap forms part of the aperture. A weakly conductive material is provided on one of the substrates over the aperture. A planar transparent electrode is provided on another one of the substrates. An alignment surface is provided on the substrates over the electrodes. A layer of liquid crystal material is contained by the substrates and in contact with the alignment surface of the substrates. A floating transparent electrode is provided on a side of one of the substrates opposite the outer and the internal hole patterned electrode.
Abstract:
A tunable liquid crystal optical device is described. The optical device has an electrode arrangement associated with a liquid crystal cell and includes a hole patterned electrode, wherein control of the liquid crystal cell depends on electrical characteristics of liquid crystal optical device layers. The optical device further has a circuit for measuring said electrical characteristics of the liquid crystal optical device layers, and a drive signal circuit having at least one parameter adjusted as a function of the measured electrical characteristics. The drive signal circuit generates a control signal for the electrode arrangement.
Abstract:
A wafer level camera module may be easily connected to a host device via mounting surface contacts. The module includes an electrically controllable active optical element and a flexible printed circuit that provides electrical connection between the optical element and surface conductors on a mounting surface of the module. The surface conductors may be a group of solder balls, and the module may have another group of solder balls that make connection to another electrical component of the module, such as an image sensor. All of the solder balls may be coplanar in a predetermined grid pattern, and all of the components of the device may be surrounded by a housing such that the camera module is an easily mounted ball grid array type package.
Abstract:
A focus free camera module uses fixed lenses within a housing that are combined with an electrically controllable active optical element, such as a tunable liquid crystal lens. The fixed lenses provide a desired amount of optical power, but the manufacturing tolerances of the module are insufficient to ensure a proper focus of an image on an image sensor. The active optical element is therefore used to compensate for any variations in the optical power to achieve the desired focus. To ensure an effective compensation, the module may be constructed so that, when the variation in optical power due to manufacturing tolerances is at a maximum, the desired focus is achieved when the active optical element is at zero optical power. All other variations may then be compensated by adjusting the active optical element to increase its optical power.
Abstract:
A wafer level method of manufacturing a liquid crystal optical device removes the need for a rigid barrier fillet while minimizing any risk of contamination of the liquid crystal. An uncured adhesive may be deposited on a bottom substrate and partially cured to form a liquid crystal barrier. After addition of the liquid crystal and a top substrate, the adhesive is fully cured to bond the substrate layers together. An uncured adhesive may be used together with the partially cured adhesive, and may be deposited separately or filled into an extracellular matrix surrounding a plurality of liquid crystal cells. The adhesive may be cured by a variety of means, including light that may be spatially modulated. One or both of the substrates may be deformed during assembly so as to create a structure with a lensing effect on light passing through the liquid crystal region.
Abstract:
Liquid crystal optoelectronic devices are produced by fabricating a wafer- level component structure and affixing a plurality of discrete components to a surface structure prior to singulating the individual devices therefrom. After singulation, the individual devices include a portion of the wafer-level fabricated structure and at least of the discrete components. The wafer-level structure may include a liquid crystal and controlling electrodes, and the discrete components may include fixed lenses or image sensors. The discrete components may be located on either or both of two sides of the wafer-level structure. Multiple liquid crystal layers may be used to reduce nonuniformities in the interaction with light from different angles, and to control light of different polarizations. The liquid crystal devices may function as optoelectronic devices such as tunable lenses, shutters or diaphragms.
Abstract:
A liquid crystal lens or beam steering device is made by programming alignment surfaces of the LC cell walls using a programming field to align the alignment surface molecules before fixing them. By setting the desired pre-tilt, the lens can operate in the absence of the control field, and power consumption by the control field can be reduced.
Abstract:
A variable angle beam control device is capable of maintaining the same color temperature of the light source regardless of the changes in the angle of the beam. The controllable light beam device has a light source with primary optics producing a low divergence light beam having an inverted angular distribution of the correlated color temperature (CCT), and a liquid crystal device with an electrically variable refractive index distribution arranged to receive said light beam and to provide a variable angle beam.