Hong Kong Applied Science and Technology Research Institute Company, Limited

Kin Lung Chan

Ming Wai Alwin Tam

Xiuling Zhu

Wei Zhang

Kwok Sing Cheng

Ying Wang

Weiping Tang

Zhuanyun Zhang

Chun Yip Wong

Kam Ho Samuel Poon

Peisong Hua

Zhiqi Yao

Kam Ho Poon

Dehua Liu

Man To Chow

Anti-counterfeiting is benefited by integrating both optical and digital encoding-decoding approaches for spoof protection, e.g., in print anti-spoofing. An optical-digital encoding-decoding system uses an encoded medium, such as a security label, to display images encoded with digital data, and a decoding device to decode or decrypt the digital data for achieving stronger authentication in anti-counterfeiting or other security-related purposes. The images are encoded into resonant waveguide gratings (RWGs) in the encoded medium, enabling angle multiplexing of the displayed images and addressing different secrecy requirements in optically handling different groups of security-related data. Furthermore, aperiodic diffraction gratings instead of periodic ones are used in RWGs for selected images intended to be viewed by users, broadening beamwidths of outgoing light beams generated by these RWGs to allow the selected images to be more conveniently viewed by the users over a wider range of angle.

Optical-digital encoding-decoding system

An apparatus installed in a head-mounted display (HMD) has a coupling prism formed by packing diagonally-reflective (DR) prisms together. Each DR prism has an internal diagonal plane that is at least partially reflective. A captured image of eye or environmental scene received by a DR prism is reflected to an image-leaving end surface thereof. Image-leaving end surfaces of all DR prisms are oriented along a same direction to optically multiplex the captured images to create a multi-channel image. An imaging sensor on the coupling prism images the multi-channel image, avoiding inter-channel interference caused by spillover of captured-image signals while allowing one imaging sensor instead of multiple ones to image the captured images. A micro display displays a visible image to one DR prism, whose internal diagonal plane reflects the visible image along a direction towards an eye. Hence, the apparatus also enables image displaying to a HMD wearer.

Imaging apparatus integrated with display for head-mounted display

Systems and methods providing optical structures providing a large field of view (FOV) for personal portable displays are described. An optical structure of embodiments comprises a catadioptric optical configuration configured to produce a magnified curved intermediate image, wherein the magnified curved intermediate image is furthered magnified with proper reflection angle and transmitted to viewer's eye. The catadioptric optical configuration may comprise two curved mirrors and a polarization prism. Optical structures comprising such catadioptric optical configurations may utilize relatively small sized image sources to produce a large FOV. Such optical structures are well suited for use in large FOV optical see through (OST) head-mounted displays (HMDs).

Large field of view see through head mounted display having magnified curved intermediate image

A rotational geometric phase hologram has geometric phase optical elements (GPOEs) serially cascaded along a common optical axis to form a GPOE cascade used for receiving a linearly-polarized light beam and generating output light beams at an exit surface of the last GPOE. Interference occurred in the output light beams creates a polarization interference pattern on the exit surface. A photoalignment substrate, when positioned in close proximity to the exit surface, records the pattern. Advantageously, each GPOE is rotatable about the common optical axis. Respective rotation angles of the GPOEs are determined according to a spatially-varying linear polarization orientation distribution selected to be generated for the polarization interference pattern. Particularly, the respective rotation angles are reconfigurable to provide the periodicity required for the spatially-varying linear polarization orientation distribution over a range of allowed periodicities while keeping the periodicity of spatially-varying optic axis orientation distribution of each GPOE to be fixed.

Rotational geometric phase hologram with application for fabricating geometric phase optical element

A system for detecting a gazing point of a user in a three-dimensional (3D) space based on a virtual screen is provided. The system includes at least a processor and a wearable device, the wearable device further comprising an external camera arranged for capturing images of the user's field of view, and two internal cameras arranged for capturing binocular images of the user's left and right eyes. The processor is designed to determine the gazing point of the user based on a virtual screen. The coordinates of the pupil center as determined according to the images from the internal cameras are mapped to the images from the external camera based on a left and a right mapping relationships, which further mapped to the virtual screen as an intermediate screen for calculating the 3D coordinates of the gazing point.

3D gazing point detection by binocular homography mapping

A device for controllably deflecting a first circularly-polarized (CP) light beam from an incident direction with fast response comprises a polarization selector (PS) to adjust the incident light beam's sense of rotation to a desired one to form a second CP light beam, and a polarization grating (PG) to deflect the second CP light beam according to the desired sense of rotation. The PS comprises an optical modulator sandwiched between two quarter-wave plates. The optical modulator has at least one ferroelectric liquid crystal (FLC) half-wave plate (HWP) being reconfigurable in fast axis orientation. The device has a fast response in beam steering due to a short time of reconfiguring the FLC HWP. Based on serially cascading multiple units each being this device, a beam-steering apparatus having fast response and enhanced steering resolution is obtained. The apparatus is usable for enhancing a field of view in projecting an image.

Beam-steering apparatus with fast response and enhanced steering resolution

A bi-sensing optical system capable of transmitting signals for eye and object tracking and/or detection, and/or capable of transmitting signals comprising visible light to an eye of a user and non-visible light for eye tracking and object detection and/or tracking is disclosed herein.

Growing community of inventors

Hong Kong, China

Kin Lung Chan