A liquid crystal display device having first and second substrates with a liquid crystal layer therebetween, a plurality of gate signal lines and a plurality of drain signal lines, a plurality of counter voltage signal lines, a plurality of pixel regions defined by neighboring gate signal lines and drain signal lines. and a counter electrode and a pixel electrode formed on the first substrate in each pixel region so as to enable an electric field to be formed therebetween. The counter electrode is of planar shape and made of a transparent conductor. The counter voltage signal line is made of metal and has a branch in each pixel region with the counter electrode being directly connected to the branch.

Liquid crystal display device comprising two counter voltage signal lines having two branches in each pixel region

Apparatus and method of monitoring for obstructions in a pipe or channel. The method comprising the steps of: (1) transmitting a wave into a first end of the pipe or channel from a transmitting transducer at a first known location relative to the pipe or channel, wherein the frequency f of the transmitted wave ( 13 ) varies in a predictable manner governed by the function f=f(t), where t is time; (2) noting the frequency f tr of the transmitted wave; (3) detecting any reflections of the transmitted wave travelling towards the first end of the pipe or channel at a receiving transducer at a second known location relative to the pipe or channel; (4) determining the frequency f rec of the reflected wave ( 14 ); (5) comparing the frequency f tr of the transmitted wave and the frequency f rec of the reflected wave, being transmitted from and being received by the respective transducers at the same time t; and 6) determining the distance L from the transmitting transducer to an obstruction and back to the receiving transducer from the difference Δf between the frequency f tr and the frequency f rec .

Apparatus and method for detecting obstructions in pipes or channels

A device for detecting a resonant frequency comprises a sound source, a switch, a mixer, and a sound meter The switch and mixer are capable of switching between a first state in which the switch and mixer output a measurement signal and a second state in which the switch and mixer output a synthesized signal containing the measurement signal and the signal output from a microphone The device detects the resonant frequency based on comparison between the first amplitude frequency characteristic measured in the first state and the second amplitude frequency characteristic measured in the second state

Method of detecting resonant frequency, method of selecting resonance frequency, and device for detecting resonant frequency sensor

A method for measuring the complex frequency-dependent dilatational and shear wavespeeds of a slab of material subjected to insonification. Transfer functions that are obtained by insonifying the material at different angles. Once this is accomplished, the transfer functions are manipulated with an inverse method to yield closed form values of dilatational and shear wavespeeds at any test frequency. The wavespeeds can be combined to determine complex Lame constants, complex Young's modulus, complex shear modulus, and complex Poisson's ratio.

Method to estimate the mechanical properties of a solid material subjected to isonification

A resonance frequency sensor (20) comprises sound source means (21), signal combining switch means (26, 27) and measuring means (25). The signal combining switch means (26, 27) switch between a first status of outputting a measurement signal and a second status of outputting a synthetic signal generated by combining the measurement signal and the output signal from a microphone (14). The sensor (20) determines the resonance frequency on the basis of comparison between a first amplitude frequency characteristic measured in the first output status and a second amplitude frequency characteristic measured by the second output status.

Resonance frequency sensing method, resonance frequency selecting method, and resonance frequency sensor

A method and system for acoustic treatment performance testing in a free-ld acoustic environment is provided. A sound source directs a gated acoustic pulse at an acoustic treatment. Acoustic pressures of the gated acoustic pulse and reflected energy from the acoustic treatment are measured from a location approximately in-line with the source and the acoustic treatment. This measurement location is at least one-half the wavelength of the frequency of interest away from the source and is at least a distance equal to (t*c/2) away from the acoustic treatment where t is equal to the duration of the gated acoustic pulse and c is equal to the speed of sound in the free-field acoustic environment. The acoustic pressures of the gated acoustic pulse and reflected energy are compared as an indication of performance of the acoustic treatment at a frequency of interest.

Paul W. Wynn

Papers

Acoustic treatment performance testing