Hong Kong Applied Science and Technology Research Institute Company, Limited

The Hong Kong University of Science and Technology

The University of Hongkong

Xiuling Zhu

Zhiguo Meng

Jiaxin Sun

Hoi-Sing Kwok

Man Yu Wong

Ming Wai Alwin Tam

Hoi Sing Kwok

Yaojun Feng

Kin Lung Chan

Chenjung Tsai

Xiaohan Wang

Xurong Li

Vivian Wing-Wah Yam

Man Chit Wong

Zhuanyun Zhang

Shou-Lung Chen

Dongli Zhang

Chun Yip Wong

Chi Kin Wong

Lichun Ye

Ting Hao

Kin Lung Kenny Chan

Kwan-Wah Ng

Zeineb Ben Aziza

Kenny Chan

Man-Chung Wong

Wai Shan Lau

A multilayered optical security device has a resonant waveguide grating (RWG) layer on an under layer having a hologram. The RWG layer has plural RWGs for generating one or more patterns. Each RWG has first and second RWG portions, with diffraction gratings of different grating periods, for light coupling-in and coupling-out, respectively. Using the RWGs minimizes interference to a holographic image generated by the under layer. This advantage is especially useful when the holographic image carries digital data such as in digital holographic encryption where an encrypted hologram is used in the under layer. The digital data may contain biometric information such as a fingerprint. In each RWG portion of an individual RWG, scattering elements in a grating are curved to thereby enhance an angular tolerance in azimuthal angle during observing the patterns by an observer while the individual RWG is still selective in elevation angle.

Multilayered optical security device

Polarization-independent focusing is advantageously achieved by a multifocal system having a polarization beam splitter (PBS) to split an unpolarized light beam into two orthogonally linearly-polarized (LP) light beams. The two LP light beams are reflected by mirrors to travel in opposite directions and enter into a variable-focusing module at two ends thereof, respectively. The module includes waveplates to convert the LP light beams into two circularly-polarized (CP) light beams at both ends of an optical assembly. The optical assembly is formed with a stack of birefringent optical elements including at least one geometric phase lens and one polarization selector that may be electrically modulated to select the optical power in focusing the two CP light beams. Followed by the waveplates converting two focused CP light beams to two focused LP light beams and upon mirror reflection, the beams are finally recombined by the PBS to form one focused light beam.

Multifocal system with polarization-independent focusing

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 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

According to the present invention, a multi-dimensional image detection apparatus includes a touch surface, at least one two-vision image sensing module located proximally to the touch surface, and a control module coupled to the image sensing module. The multiple-dimensional image detection apparatus can detect a foreign object's image with at least two different dimensional modes. A method of multiple-dimensional image detection is also disclosed by reading the image data acquired by the image sensing module and comparing with a pre-stored background data to determine detecting the foreign object under a predetermined dimensional mode.

Multi-dimensional image detection apparatus

A system for determining a touch point's location within a user-definable region is provided. The system comprises plural modules. In a set-up stage, a user positions each module to define a peripheral point of the region. Exemplarily, a module comprises a means for detecting alignment between the module and another one, a means for measuring an inter-module distance, and a means for making wireless data communication. In particular, the detecting of the alignment and the measuring of the inter-module distance are configured to be performed without physically connect the two modules together. Hence, a geometric coordinate of the module relative to the other one is determinable without a need to physically connect the two modules. The system can thereby be compactly packed for traveling to give an advantage of high portability to a portable interactive whiteboard system that incorporates such system.

Portable interactive whiteboard module

The present invention is to provide a method and system for determining true touch points on input touch panel. Two optical sensing module pairs are used to determine two groups of possible touch regions, further with overlap checking with virtual shadow regions to find out potential touch points. Occlusion checking is implemented to acquire true touch points from the potential touch points. The method of the present invention is capable of acquiring true touch points in a fast and reliable way. Furthermore, an interactive input system of the present invention comprises optical sensing modules having their corresponding optical emitters with different wavelengths, and light filters with peak transmission at different wavelengths to avoid from interference effect and over-exposed signal during signal detection by the optical sensing modules.

Method and system for determining true touch points on input touch panel using sensing modules

A coordinate locating device capable of locating the coordinates of two or more objects is provided for a display apparatus. The coordinate locating device includes a first detector arranged together with a first light source at a first corner of the coordinate locating device, a second detector arranged together with a second light source at a second corner of the coordinate locating device, at least one reflector configured to reflect light from the first and second light sources, and a mirror arranged on a first edge of the coordinate locating device, configured to reflect mirrored images of two or more objects intruding the coordinate locating device, wherein the first and second detectors detect real images of the two or more objects, and at least one of the first and second detectors further detects the mirrored images of the two or more objects reflected by the mirror.

Coordinate locating method, coordinate locating device, and display apparatus comprising the coordinate locating device

The present invention provides a method of an active-matrix thin film transistor array, comprising of two levels of metallic interconnections formed from one layer of metallic conductor; and thin-film transistors with source, drain and gate electrodes either fully or partially replaced with metal, and wherein the pixel electrodes are polycrystalline silicon.

Method for fabrication of active-matrix display panels

A coordinate locating apparatus for locating at least one touch point on a plane and the method thereof are provided. The coordinate locating apparatus comprises: a first detecting unit, comprising a first light emitting element and a first light receiving element, arranged at a first location of the plane; a second detecting unit, comprising a second light emitting element and a second light receiving element, arranged at a second location of the plane; a first optical element arranged along an edge of the plane for reflecting and retro-reflecting light from the first and the second light emitting elements; and a second and third optical elements arranged along two edges of the plane for performing at least one of reflecting and retro-reflecting light from the first and the second light emitting elements or light reflected from the first optical element, both of the two edges being adjacent to the edge along which the first optical element is arranged, wherein the at least one touch point is located on the basis of the detected intensities of light received by the first and the second light receiving elements, and the detected intensities of light are compared with a first threshold and a second threshold.

Coordinate locating method and apparatus

A touch panel capable of recognizing at least one gesture and the method thereof are provided. The touch panel comprises: a first optical unit, comprising a first light emitting element and a first light receiving element, arranged at a first position of the touch panel; a first optical element arranged along a first edge of the touch panel for reflecting light; a second and a third optical element arranged along a second and a third edge of the touch panel, respectively, for retro-reflecting the light, the second edge being adjacent to both the third edge and the first edge; and a processing unit for recognizing the at least one gesture according to changes to distance and slope of possible touch points.

Multiple-input touch panel and method for gesture recognition

A coordinate locating device for a display apparatus is provided, which can have lower manufacturing costs and can locate the coordinates of a single or multiple objects. The coordinate locating device includes a light source configured to emit light, wherein said light source comprises a light emitting device, at least one reflector configured to reflect the light from the light source, and a detector configured to detect the light reflected by the at least one reflector, wherein the light source and the detector are disposed at different positions on the same edge of the coordinate locating device.

Metal induced polycrystallized silicon is used as the anode in a light emitting device, such as an OLED or AMOLED. The polycrystallized silicon is sufficiently non-absorptive, transparent and made sufficiently conductive for this purpose. A thin film transistor can be formed onto the polycrystallized silicon anode, with the silicon anode acting as the drain of the thin film transistor, thereby simplifying production.

Polycrystalline silicon as an electrode for a light emitting diode and method of making the same

An organic light-emitting diode display which can display independent images on both sides is described. This display can be driven with passive matrix or active matrix schemes. The invention combines a unique stacked organic diode structure and special driving schemes involving time-sequential reversed fields.

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Hong Kong, China

Xiuling Zhu