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The growth of the nanotechnology and intense studies on subwavelength nanophotonics has facilitated research in the field of metamaterials and metasurfaces. Optical waveguides has been a proper platform for metasurface applications because of its versatility and numerous infrastructure. In this paper, a metasurface interconnection method via attaching antiresonant waveguide is introduced. The antiresonant waveguide allows all-waveguide type inline metasurface schematic. Numerical calculations verified that the antiresonant fiber is capable of metasurface interconnection. In addition, an inline optical transmission modulator has been proposed by filling liquid crystal inside the hollow region. A liquid crystal device with on- state transmittance of 93.64%, and off-state transmittance of 0.96% with a smooth transient region are achieved.

An all-liquid-crystal device for fast orbital angular momentum encoding and optical vortex beam steering is proposed and demonstrated. It is a combination of a cascaded spin-determined beam deflector and an optical vortex generator. The fast switching derives from the rapid in-plane optical axis rotation of ferroelectric liquid crystal half-wave plates, while the q-plate and meta-q-plate made by photopatterned liquid crystal polymer ensure high-quality and efficient orbital angular momentum encoding. By programing the binary signals applied to the half-wave plates, electrical optical vortex deflection and 32 different orbital angular momentum encoding are achieved faster than 70 µs with a total efficiency over 85%. It supplies a practical strategy for fast optical vortex steering and orbital angular momentum encoding and may be broadly used in vortex LiDAR, multitarget communications and orbital angular momentum multiplexed optical telecoms. [ABSTRACT FROM AUTHOR]

The thermistor was fabricated by filling the nematic liquid crystal (NLC) material IM95100-000 into a liquid crystal device with an interdigital electrode structure. In the temperature range of 25 °C–120 °C, the temperature response of the thermistor under different voltages was measured with a step length of 5 °C to study its performance. The experimental results show that the resistance value of the thermistor decreases exponentially with increasing temperature in the range of 25 °C–120 °C. The temperature resistance characteristics at different voltages can satisfy the Steinhart-Hart formula well and the nonlinear fitting coefficient can reach 0.999; under the voltage of 1 V, the total resistance percentage changes by 93.1%, the material constant B25-120 value can reach 3299.07 K, and the temperature coefficient of resistance (TCR) can reach 0.98%/K. As a temperature sensor, it is twice as sensitive as that without the interpolated electrode structure, and the sensitivity can be further improved as the temperature decreases. Through the stability and recovery measurements, it is found that the resistance has no obvious deviation, which verifies the possibility of long-term application of this thermistor. [ABSTRACT FROM AUTHOR]

We report continuously tunable and bandwidth variable optical notch and band-pass filters created by combining four left- and right-handed circular cholesteric liquid crystal cells without extra optical components. Filter performance was greatly improved by introducing an anti-reflection layer on the filter device. The filter comprised cholesteric liquid crystal wedge cells with continuous pitch gradient. The band wavelength position was spatially tuned from 470 nm to 1000 nm. The notch filters are polarization-independent in the spectral ranges. The band pass filters can be designed to be polarization-independent or polarization-dependent via cell alignment and the bandwidth can be reversibly controlled from the original bandwidth (60~18 nm). These tunable filter strategies could make a paved road to wavelength tunable spectroscopic instruments applications in the VIS and near infrared response spectral range.

We report electrically re-configurable liquid crystal core rib waveguide based electro-optic switch. It is proposed to use single side anchored in-plane switching (IPS) configuration for optical switching in view of its low threshold voltage and low switching voltage in comparison to that in a double-side anchored LC waveguide switch. Further, the proposed LC waveguide based switch has better response time than that in a double side anchored configuration at operating voltage close to threshold voltage of a double side anchored. The device has been realized on a BK7 glass substrate using E7 LC. We also show wavelength re-configurability of the switch over a wide wavelength range (1 – $3~\mu \text{m}$) by externally applied voltage. Proposed work would be useful for optical signal processing on integrated optic platform. [ABSTRACT FROM AUTHOR]

An InP-based Vertical-Cavity Surface-Emitting Laser (VCSEL) with a liquid crystal (LC) microcell monolithically integrated on its surface for spectral tuning is investigated. Unlike tunable VCSELs integrating a movable membrane, here the physical length of the cavity remains unchanged and only the voltage applied on the LC ensures a refractive index modification for a particular polarization emitted by the VCSEL. This tunable VCSEL operates in CW at room temperature and exhibits more than 23 nm wavelength tuning around 1.55 μm at a maximum applied voltage of 20 V. The measured laser threshold around 6.5 mW is still comparable to VCSEL without LC microcell, a clear indication that the optical losses related the LC are very low. On the other hand, for this first optically pumped device, the lasing characteristics suggest that the LC birefringence is lower than expected. To assess this hypothesis, thermo-optical simulations have been conducted. [ABSTRACT FROM AUTHOR]

For distance detection, a tunable aperture using liquid crystal is proposed, achieving high resolution images in real-time. The tunable aperture inserted into a camera has been designed to two sizes, which can create different Depth of Field images. By analyzing these two images, distance to object can be extracted. Initially, the aperture has large size with zero voltage. When the driving voltage is applied, the aperture transfers itself to smaller size by realignment of liquid crystal molecules in the device. The diameter of aperture is 4.4 mm with f/1.8 and 2.0 mm with f/4.0. The proposed device has low driving voltage of 2.8 V and fast response time of 9.84 ms. Compact size aperture of $10\times {10}\times 1.8$ mm3 is assembled in a camera with focal length of 8 mm which contains 5 glass lenses and 1/2.7- inch full high definition (FHD) image sensor. The tunable aperture has high stability due to no mechanically moving parts. This distance sensor can be applied to the various field of depth map application which is the self-driving car, drones and manufacturing machine. [ABSTRACT FROM AUTHOR]

We report continuously tunable and bandwidth variable optical notch and band-pass filters created by combining four left- and right-handed circular cholesteric liquid crystal cells without extra optical components. Filter performance was greatly improved by introducing an anti-reflection layer on the filter device. The filter comprised cholesteric liquid crystal wedge cells with continuous pitch gradient. The band wavelength position was spatially tuned from 470 nm to 1000 nm. The notch filters are polarization-independent in the spectral ranges. The band pass filters can be designed to be polarization-independent or polarization-dependent via cell alignment and the bandwidth can be reversibly controlled from the original bandwidth (60∼18 nm). These tunable filter strategies could make a paved road to wavelength tunable spectroscopic instruments applications in the VIS and near infrared response spectral range. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical model of the rectangular-shaped microstrip patch antennas on liquid crystal (LC) substrates in order to accurately derive the resonant frequencies and radiation performances. The model is based on the solution of the mode matching about an LC loaded cavity. The calculation results of the theoretical model are compared with the experiment and simulation results. The discrepancy between calculation and simulation results is merely 2.7%. In addition, a tuning mechanism of the patch antenna on the LC substrate is verified depending on the strength of a biasing voltage. The calculated results of the theoretical model indicate that the resonant frequency is shifted toward lower direction and 3-dB beamwidth of radiation pattern increases as the bias voltage increases. Although the calculated maximum directivity decreases with the increment of voltage, the realized gain increases due to the radiation efficiency of the antenna. [ABSTRACT FROM AUTHOR]

A simple technology is demonstrated for the wafer-scale fabrication of liquid-crystal (LC) microcells that can be integrated in active optoelectronic devices. Fabrication of 1.55- $\mu \text{m}$ tunable Fabry–Perot optical micro-filter arrays is achieved owing to the insertion of a single nanoimprinted polymer grating dedicated to LC alignment and to the soft thermal transfer of a dry thick resist film between two highly reflective mirrors. The filter exhibits a spectral tuning range of 102 nm with only 18 V applied, as well as negligible internal loss, which makes it suitable for being inserted in a laser cavity. This constitutes a key step toward the large-scale integration of widely tunable photonic devices such as vertical-cavity surface-emitting lasers using LC technology. [ABSTRACT FROM AUTHOR]

In this paper, the design and characterization of the sloped-field-plate enhanced trench edge termination structure are carried out. For achieving the ideal planar junction breakdown voltage and high dV/dt performance, structural parameters, including the depth of the sloped-field-plate and the depth and width of the trench, need to be well designed. Using extensive numerical simulations, the above-mentioned design is accomplished. Experimental results show that for 600 V class devices, a breakdown voltage of 757 V can be achieved by the devices with a trench width larger than 20 \mu \textm . The breakdown characteristics are verified as the ideal planar junction breakdown by using liquid crystal thermal measurement. Furthermore, the high dV/dt measurement results show that the devices with a trench width larger than 25 \mu \textm are capable of handling a high dV/dt of 28.9 kV/ \mu \texts even at a bus voltage of 750 V. [ABSTRACT FROM AUTHOR]

We demonstrate an electrically controlled optical switch based on nematic liquid crystal (LC) core waveguide, fabricated on an ITO-coated glass substrate, with upper and lower cladding layers of the negative photoresist AZ15nXT. The reorientation of the LC molecules in the presence of an applied electric field produces distinct guiding properties for the TE and TM polarizations of light. Considering full anisotropy of the LC, the thickness of the cladding layer is chosen suitably to minimize the propagation loss of guided modes. The fabricated device operates at a threshold voltage of 3.5 Vpp, and behaves as an optical switch for TM polarization of light with an extinction ratio > 15 dB. We experimentally achieved a relatively low insertion loss ∼7.96 dB at the applied voltage of 10 V for a waveguide of length 10 mm. The proposed device has potential application as an electrically controlled optical switch or retarder, particularly for low frequency applications. [ABSTRACT FROM PUBLISHER]

This letter discusses the frequency effect of polymer-stabilized blue-phase liquid crystal (BPLC) on the data voltages of a conventional pixel circuit and develops a new pixel buffer that exploits amorphous indium–gallium–zinc-oxide thin-film transistors (TFTs). During high-speed operations, BPLC seriously distorts data voltages because of the highly frequency-dependent dielectric anisotropy. To lessen the frequency-dependent effect of BPLC, a source-follower structure is integrated into the proposed pixel buffer to prolong the charging time of the BPLC cell. The experimental results show that the source-follower yields linear output characteristics. Further compensation for TFT ${{\text{V}}}_{{\mathrm{TH}}}$ shifts and suppressing the leakage current are confirmed to make the data voltages on the BPLC cell highly uniform and stable. [ABSTRACT FROM AUTHOR]

The electrically tunable liquid crystal (LC) optical channel waveguide with strong polarization-dependent mode tunability is demonstrated for the first time. When the applied voltage increases, the LC molecules encapsulated in the semicircular groove on the fused silica substrate gradually tilt upward and twist toward two sides. For TE polarization, the applied voltage slightly decreases the effective index and has a small effect on the field distribution of the guided mode. As to TM polarization, electrical tuning greatly enhances the effective index as larger as 2.234 ×10-1 and causes an obvious variation of the mode size. The TM polarization has the lowest propagation loss 0.94 dB/cm up to date. It is attributed to high-optical quality substrate and smooth groove surface produced by chemical etching with the composite mask. The LC reorientation distribution and the full-vectorial guided mode characteristics at various voltages are calculated to explain the experimental results. The proposed LC-core channel waveguide owns the unique feature of strong polarization-dependent mode tunability and can be used as promising devices, such as ultrashort phase modulator, pulse-delayed device, and polarization controlling device. [ABSTRACT FROM PUBLISHER]

We propose a tunable add-drop multiplexer in a silicon waveguide Mach-Zehnder interferometer that has a sampled grating structure and ferroelectric liquid crystal (FLC) cladding, which we fabricated. The effective coupling coefficient that was decreased by the sample grating structure led to a narrow stop bandwidth in the grating waveguide. The FLC material caused a change in the Bragg conditions for lightwave propagation in the waveguide according to the direction of the electric field applied to FLC. The switching operation of the fabricated device, which separated the input and reflected signals without a circulator, was successfully demonstrated. The time response, dependence on voltage, and memory operation of the fabricated device based on FLC characteristics are also reported. [ABSTRACT FROM PUBLISHER]

Multispectral imaging and photometric stereo are common in 3D imaging but rarely have been combined. Reconstructing a 3D object's shape using photometric stereo is challenging owing to indirect illumination, specular reflection, and self-shadows, and removing interreflection in photometric stereo is problematic. A new multispectral photometric-stereo method removes interreflection on diffuse materials using multispectral-reflectance information and reconstructs 3D shapes with high accuracy. You can integrate this method into photometric-stereo systems by simply substituting the original camera with a multispectral camera. [ABSTRACT FROM PUBLISHER]

The polarization conversion of a twisted nematic liquid crystal device can be completely characterized by the physical parameters, including the cell parameters and equivalent birefringent parameters. Periodic ambiguity is unavoidable in the measurement; therefore, the exact values of these parameters cannot be uniquely determined. To solve this problem, phase-shift imaging polarimetry is developed to measure the spatial distribution of the physical parameters of a twisted nematic liquid crystal device without periodic ambiguity. The proposed method experimentally showed that as few as eight intensity images are adequate to uniquely determine all of the physical parameters based on an analytical approach. [ABSTRACT FROM PUBLISHER]

A method is proposed for determining the cell gap, twist angle and pretilt angle of twisted nematic liquid crystal (TNLC) cells. In the proposed approach, the effective optical parameters of the TNLC cells are measured using a Stokes polarimetry method and the physical optical parameters are then extracted from these effective parameters using a simple analytical technique. The experimental results for the TNLC cell show that the extracted values of the twist angle, pretilt angle and cell gap are Φ = 89.864°±0.028°, ξ = 1.806°±0.050° and d=10.696 μm±0.025 μm, respectively. The experimental results for the twist angle and cell gap deviate from the known values by just ΔΦ = 0.136° and Δd=0.196 μm, respectively. Moreover, the pretilt angle is found to lie in the reliable range. In contrast to existing methods, the technique proposed in this study requires the use of only a single illuminating wavelength. As a result, it provides a cheaper and more straightforward approach for extracting the three physical parameters of TNLC cells than existing optical-parameter measurement schemes. [ABSTRACT FROM PUBLISHER]

Recently, liquid crystal (LC) polarization gratings (PGs), because of several advantages, have become extremely popular although the process for analysis and optimization of different optical characteristics is still very complicated. Here, we reveal a simplified model (SM) to evaluate and optimize the performance of LCPGs. Unlike the existing extended Jones matrix (EJM) method, the SM excludes the layer-by-layer analysis and considers an effective twist that reduces the complexity of the calculations. In addition, obtained results from the SM have been compared with the EJM model for variety of conditions and found in good agreement. Furthermore, the proposed SM can also be used for variety of LC photonic elements viz., polarization convertors, polarization rotators, and so on. [ABSTRACT FROM PUBLISHER]

We have developed new analytical expressions for designing liquid crystal (LC) microlenses. These equations are based on a novel equivalent electric circuit and can be used to create an optimum design for the LC lenses in which the lens diameter ranges from a few micrometers to several millimeters. Thus far, only experimental studies have been conducted on the LC lenses. The analytical expressions developed in this letter depend on various manufacturing parameters and can be used to design lenses with specific focal lengths and a parabolic phase profile. The required driving scheme (modal or hole-patterned) can be predicted. The LC microlenses were manufactured and electrooptically characterized: the measurements were compared using an analytical approach. [ABSTRACT FROM PUBLISHER]

In this paper, we present a novel projection-type 3-D integral imaging display with an adaptive liquid crystal (LC) prism array. Comparing with conventional integral imaging display, the proposed system demonstrated that the viewing zones for a projection type integral imaging display was successfully extended by time-multiplexed technique and without any mechanical movement. To the best of our knowledge, this is the first report on combining an adaptive LC prism array with the projection-type integral imaging 3-D display. The proposed display is attractive for future wide viewing zone projection-type integral imaging 3-D displays. [ABSTRACT FROM PUBLISHER]

A novel fabrication method using holographic exposure for switchable blue phase (BP) liquid crystal (LC)/polymer Fresnel lens was demonstrated. The Fresnel pattern can be achieved by interfering a planar and a spherical wave fronts with a 532-nm laser. The BPLC/polymer Fresnel lens can thus be fabricated without photo mask and controlled with a simpler driving compared with the conventional LC Fresnel lens. [ABSTRACT FROM PUBLISHER]

Liquid crystal (LC) lenses have been the subject of research due to their advantage of focal length tunability that brings added value to applications typically based on conventional gradient index lenses. A novel approach for modeling the unwrapped phase defects in modal LC microlenses is presented. For solving the gradual voltage across the lenses, the proposed analytical method uses only circuit theory exploiting partial differential equations and conformal mapping techniques. The LC molecular ordering has been modeled on the basis of the continuum theory and optical response has been deduced through inspection of phase retardations. The model validity has been checked for predicting some defects of the modal microlenses in the phase of the lens design, comparing experimental characterization with simulation. [ABSTRACT FROM PUBLISHER]

Recent advances in both nano-fabrication and nano- materials open up rich new avenues in the optical sensing area. Using nano-grid electrodes, nanometer-scale photo-alignment layers and deformed helix ferro-electric liquid crystals with a sub-wavelength helix pitch of 150 nm, we have realised a fully integrated polarisation-based photonic transducer which exhibits fast response to an applied voltage/electric field, excellent linearity and allows multiplexing using standard, low cost telecom optical fibers. [ABSTRACT FROM PUBLISHER]

A reconfigurable reflectarray which exploits the dielectric anisotropy of liquid crystals (LC) has been designed to operate in the frequency range from 96 to 104 GHz. The unit cells are composed of three unequal length parallel dipoles placed above an LC substrate. The reflectarray has been designed using an accurate model which includes the effects of anisotropy and inhomogeneity. An effective permittivity that accounts for the ‘real effects’ of the LC has also been used to simplify the analysis and design of the unit cells. The geometrical parameters of the cells have been adjusted to simultaneously improve the bandwidth, maximize the tunable phase-range and reduce the sensitivity to the angle of incidence. The performance of the LC based unit cells has been experimentally evaluated by measuring the reflection amplitude and phase of a reflectarray consisting of 52\,\times\,54 identical cells. The good agreement between measurements and simulations validates the analysis and design techniques and demonstrates the capabilities of the proposed reflectarray to provide beam scanning in F band. [ABSTRACT FROM AUTHOR]

We propose and demonstrate a new modified Lyot filter to independently ensure the channel amplitude equalization and the bandwidth tuning functions. The device consists of hybrid liquid crystal interferometers. We show numerically and experimentally that for a modified four-stage Lyot filter, the two first interferometers ensure equalization function with a maximum extinction ratio, while the last interferometer allows full-width at half-maximum tuning function by using, in particular, the optical canceling approach. Such a device is highly desirable in optical telecommunications, especially where in the core network the optical filters must perform several other functions in addition to their basic amplitude filtering action. [ABSTRACT FROM PUBLISHER]

In this paper, integration of liquid crystal (LC) capacitive chemical and biological sensor with the CMOS interface circuit has been investigated. The LC microchip provides better sensitivity compared to discrete interfacing and array of sensors can be fabricated to reduce false positives. For high sensitivity detection, the excitation signal voltage and frequency have been examined and sensor capacitance plots are provided. Two on-chip interdigitated capacitors provide differential sensor measurement to cancel common environmental parasitic effects. The LC sensor interface circuit includes a low noise charge amplifier, synchronous demodulator, low pass filter and a sigma-delta A/D converter. The preamplifier noise has been minimized using a nonlinear optimization algorithm. The preamplifier has 15 aF resolution with 1 kHz bandwidth, while the microchip has 14-bit resolution using AMI 0.5 μm technology. [ABSTRACT FROM PUBLISHER]

In this paper an interface circuit has been designed using hydrogenated amorphous silicon (a-Si:H) thin film transistors for array of capacitive liquid crystal (LC) chemical and bio- logical sensors. Amorphous silicon has high uniformity over large area electronics and has relatively low cost fabrication process. The proposed circuit is insensitive to a-Si:H non-ideal behavior such as low mobility and threshold voltage change. The circuit provides analog input interface and has direct digital output while consuming 0.02 mm2 of chip area and 35 μW of power. More than 200 000 sensor units can be fabricated on a chip area as small as an iPad display. To the knowledge of the authors, this is the first a-Si:H interface circuit for capacitive LC chemical and biological sensor. [ABSTRACT FROM PUBLISHER]

We report an on-chip integrated ferroelectric liquid crystal (FLC) waveguide structure suitable for telecommunication applications. Single gaps with different widths of 5, 10, and 20 μ m inside individual silica waveguides were filled with an FLC mixture. The waveguide devices operate as a binary switch or an attenuator in a temperature range from 30 ° C to 60 ° C. The FLC mixture exhibited a good alignment quality in these gaps without alignment layers. A good extinction ratio of up to 33.9 dB and a low insertion loss of <; 4.3 dB at λ = 1550 nm were observed. Switching times of <; 100 μs were obtained for the low electric fields applied in this experiment. [ABSTRACT FROM PUBLISHER]

We present electric-field modeling of carbon nanotubes (CNTs) as nanorods to optimize electrode geometry in a light-modulating nanophotonic device based on CNTs and liquid crystals. The electric fields spawned by the nanotube electrodes are used to align the liquid crystal molecules to generate a gradient refractive-index profile. We considered an array of CNTs on a 2-D conducting substrate. Different geometries were realized by choosing one, two, three, and four CNTs at each point. The static electric fields produced by these different geometries were simulated. Our results show that the “four nanotube” groups generated a wide and symmetrical electric field as compared to other geometries. We have verified the simulation results by experimentally fabricating the nanophotonic device and found that the “four nanotube” groups formed a negative lens array in the liquid crystal cell with enhanced performance. [ABSTRACT FROM PUBLISHER]

Microdisplays of the liquid crystals on silicon (LCOS) type have gone through a rapid evolution during the last decade. We present an overview of how vertically aligned nematic (VAN) LCOS have evolved from an attractive, but notoriously difficult and even infamous technology, to the mainstream microdisplay technology that it is today. At the same time, we highlight a number of remaining issues and concerns, and present some ideas of how to remedy them. [ABSTRACT FROM PUBLISHER]

A novel adaptive optical splitter structure employing an Opto-VLSI processor and 4-f imaging system is proposed and experimentally demonstrated. By driving the Opto-VLSI processor with computer generated multicasting phase holograms, an input optical signal launched into an input optical fiber port can be split and coupled into many output optical fiber ports with arbitrary splitting ratios. A proof-of-principle 1\,\times\,2 adaptive optical splitter structure driven by optimized multicasting phase holograms uploaded onto the Opto-VLSI processor is developed, demonstrating an arbitrary splitting ratio over a wavelength range exceeding 50 nm. [ABSTRACT FROM PUBLISHER]

To reduce frame memory usage in LCD overdrive, block truncation coding (BTC) is commonly used due to its efficient coding and low implementation cost. However, the inherent limitation of BTC causes severe perceptual artifacts and degrades overdrive performance. To solve this problem, we propose an adaptive multi-level BTC (AM-BTC) in this paper. The AM-BTC firstly overcomes the limitation by adaptively selecting 2-level or 4-level BTC according to the edge property of the coding block. Then, to reduce the bit rate of AM-BTC we improve the 2-level and 4- level BTCs by using only luminance bit-map to represent three color bit-maps. As shown in simulation results, the AM-BTC successfully reduces the frame memory usage to 1/6 and significantly improves coding performance (up to 3.779 dB) as compared with other algorithms. When the AM-BTC is applied to LCD overdrive, it also improves overdrive performance up to 3.390 dB as compared with other competitive methods in literature. [ABSTRACT FROM AUTHOR]

In this paper, a segment-based motion estimation (ME) method for frame rate up-conversion is proposed that can achieve better visual quality for next generation video formats. The proposed ME method can reduce the computational complexity of the ME drastically by adjusting the search range (SR) for each segment and adopting a new efficient distortion criterion, called the subsampled sum of absolute differences (SSAD). The proposed method does not degrade the motion accuracy by using the temporal consistency of the segment with large size. Experimental results show that the proposed algorithm outperforms conventional methods both objectively and subjectively with the significantly reduced computational complexity. [ABSTRACT FROM AUTHOR]

This paper proposes a line inversion-based stepwise data driving scheme for use in low-power mobile TFT-LCDs. The proposed stepwise data driving scheme adopts a stepwise pull-up and pull-down transition operations of source and common lines in an LCD penal, resulting in greatly reduced power consumption as compared to the conventional line inversion-based data driving schemes. Moreover, the proposed scheme shows relatively uniform power consumption for different image patterns, making background image design easy for use in commercial portable display devices. Three test chips for mobile devices having QCIF+, QVGA, and HVGA resolutions were fabricated in a 6-V/0.7-µm quadruple-metal CMOS process. The experimental results showed that overall power reductions of 25%-37% for QCIF+, 31%-47% for QVGA, and 42%-53% for HVGA TFT-LCDs were achieved, depending on image pattern, with a die size overhead of less than 1%. They also indicated that the proposed driving scheme allowed around 55% to 32% reduction on image pattern-dependent power variation as compared to conventional driving schemes. [ABSTRACT FROM AUTHOR]

The article reports on the use of pervasive screen displays based on liquid crystal displays (LCD) or front and rear projection. Several prototypes have been developed by researchers to explore utilizing multimodal remote interaction displays to provide more intuitive human-display interaction. A sensor-based, multimodal, touchless approach is required for remote interaction with screen displays. Constraints requiring physical contact are disposed of and natural interaction with tangible digital information is permitted by processing hand gestures.

Local dimming techniques cause clipping artifacts in liquid crystal displays. To overcome the problems associated with the artifacts, the backlight luminance should be adjusted, but this process increases power consumption. In this paper we propose a novel backlight luminance compensation algorithm to reduce clipping artifacts by minimizing the increment of backlight luminance. [ABSTRACT FROM AUTHOR]

This paper presents an improved wide color-gamut technique for liquid crystal modules (LCM) with multi-phosphor white (MPW) light emitting diodes (LED) and an modified rich color image processing method. The MPW LED improves 13% of the display color gamut in comparison with standard white LED under the assumption of equal power consumption and brightness. Via many simulation results, the pixel-level rich color method is shown to obtain a superior image data by giving about 45% saturation enhancement without hue distortion. The performance and merit of the proposed technique are exemplified by conducting several experimental results on a 2.8-inch thin-film-transistor (TFT) LCM. [ABSTRACT FROM AUTHOR]

The evaluation of liquid crystal display (LCD) quality in terms of human factors shows more accurate results than conventional measurements such as image resolution and response speed. In this paper, we propose a new method for measuring eyestrain based on pupil accommodation speed according to the change of four adjustment factors---brightness, contrast, saturation, and hue---of images on an LCD TV. Experimental results showed that the order of affecting the eyestrain much was the changes of hue, brightness, contrast and saturation. Based on them, the solutions for suppressing eyestrain of watchers of LCD TV are discussed. [ABSTRACT FROM AUTHOR]

Mura is a typical vision defect of LCD panel, appearing as local lightness variation with low contrast and blurry contour. This letter presents a new machine vision inspection way for Mura defect based on the level set method. First, a set of real Gabor filters are applied to eliminating the global textured backgrounds. Then, the level set method is employed for image segmentation with a new region-based active contours model, which is an improvement of the Chan Vese's model so that it more suitable to the segmentation of Mura. Using some results from the level set based segmentation, the defects are quantified based on the SEMU method. Experiments show that the proposed method has better performance for Mura detection and quantification. [ABSTRACT FROM AUTHOR]

With the rapid development of home network technology, sharing multimedia content among AV devices has become easier, however, the operation of these AV devices have become more complicated. These devices display status and related information through On-Screen Display (OSD) or Liquid Crystal display Module (LCM) display, but the displays have some issues with OSD interference to reception or require users to understand all the symbols on the LCM Display. This paper proposes a universal remote control based on AV device virtualization, called V-URC (Virtualization based Universal Remote control), in order to control AV devices V-URC dynamically generates user interfaces, which conform to the current state of devices; this not only simplifies the operation of A V devices, but also eliminates the issues caused by LCM display and OSD-based AV devices In addition, for new A V devices, V-URC can be used directly without the need to go through complicated learning programs or update of firmware. [ABSTRACT FROM AUTHOR]

The overdrive technique has been popularly used to alleviate the motion blur on liquid-crystal display (LCD) by shortening the response time of the liquid crystal. However, this technique requires a large frame buffer to store the previous frame as a reference. In this paper, we propose a novel block truncation coding based on the vector quantizer for the color image compression in LCD overdrive. Due to the constant output bit-rate and the low computational complexity, the proposed method is suitable for the hardware implementation in LCD overdrive. Experimental results show that the proposed method achieves higher compression ratio as well as better visual quality as compared with the conventional methods. [ABSTRACT FROM AUTHOR]

A liquid crystal display (LCD)-photomask-based desktop manufacturing system that includes software and hardware configuration is described. The software design includes a slicing algorithm, an LCD photomask display, a process-user interface, and a motion control program. The bucket-sorting algorithm is used in the slicing preprocessing for search speed enhancement. The slicing time ratio can be reduced to nearly 25% with five buckets. The hardware configuration of this architecture includes an LCD photomask, an optical system, a z-axis elevator, and a personal-computer-based control system. The matrix optics assists the optical system design of the proposed RP machine. After the slicing process, a cross-sectional contour of each layer is transferred to the LCD photomask. The optical system emits parallel light upward through the photomask to expose and solidify the entire layer at once. This visible light can expose and solidify an entire layer at once, layer by layer, until the whole part is finished. We have physically demonstrated the complete system, including hardware and software implementation, and the experimental results are as what was expected and are described here. [ABSTRACT FROM AUTHOR]

In this paper, a multistring light-emitting diode (LED) backlight driving system for liquid crystal display (LCD) panels with color sequential display (CSD) and area control is proposed. In large-scale LCD panels, multistring LED backlights are required to provide sufficient back lighting. The most popular structure to achieve multistring current regulation is a current mirror. However, it cannot be applied to high-power LED (>100 mA) driving, and the number of LEDs in each string is highly limited. In the driving system, a multioutput flyback converter associated with a novel control IC is proposed to tightly regulate LED driving currents and to readily achieve CSD and area control. The proposed driving system for a 32-in LCD panel has been built, from which experimental measurements have verified that the proposed driving system has the following features: low power consumption, high power conversion efficiency, stable driving currents, and high reliability. [ABSTRACT FROM AUTHOR]

The dynamic characteristics of normal and Corbino hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) have been investigated. Top- and bottom-gate normal a-Si:H TFTs and bottom-gate Corbino a-Si:H TFTs were fabricated with a five-photomask process used in the processing. of the active-matrix liquid crystal displays. The charging time and feedthrough voltage ΔVP measurement indicates that the normal a-Si:H TFT shows a similar behavior regardless of its TFT geometrical structure. Using a simple gate-to-source capacitance CGS model, the dependence of ΛVP on gate-to-source overlap and storage capacitor has closely been estimated using analytical calculation. Due to a unique electrode geometry, the Corbino a-Si:H TFT shows a small deviation from an analytical model used for the normal a-Si:H TFT, and consequently, a modified analytical model was developed. We also developed concepts of its possible application as a switching device to active-matrix organic light-emitting displays. [ABSTRACT FROM AUTHOR]

The operation of a post-aligned bistable nematic (PABN) liquid crystal device is simulated using a dynamic finite-element implementation of the Landau–de Gennes theory in 3D. Two topologically distinct stable director profiles of higher and lower tilt angles are identified. The switching process between these two states is simulated while monitoring the variation in total free energy of the liquid crystal material. Maxima in the free energy, acting as energy barriers separating the two stable states, are shown to coincide with the formation of -1/ 2 defect lines in the director field. [ABSTRACT FROM PUBLISHER]