Auxiliary Pulse Research Articles

Improvement of low gray scale linearity using multi-luminance-level subfield method in plasma display panel

A new multi-luminance-level subfield method is proposed to improve the low gray scale linearity by implementing the inverse gamma relation from the gamma-corrected input signals of plasma display panel televisions (PDP-TVs). Multi-luminance levels can be expressed per sustain pulse in a low gray scale by applying the different auxiliary pulses in the same sustain-pulse subfields. As a result, this method can contribute to realize a high quality image by suppressing a low gray-level contour.

New driving scheme for white color balancing of plasma display panel television

This paper presents a new driving scheme based on the algorithm for the selection of the optimum auxiliary pulse to reduce the deviation of white color in an AC plasma display panel television (PDP-TV). The luminance ratio among the red, green, and blue lights can be controlled independently by applying the different auxiliary address pulses to the red, green, and blue cells during a sustain-period. As a result, white colors of eight subfields can be clustered within a region, which is not resolvable in terms of visual perception.

P‐64: Improvement of Color Gamut Using New Auxiliary Negative Pulse in AC‐PDPs

AbstractA new auxiliary negative pulse is proposed to improve the color purity by reducing the neon (Ne) emission of 585 nm in an ac PDP. Applying the auxiliary negative pulse to the address electrodes during a sustain‐period induces a new discharge mode that can reduce the Ne emission remarkably. For this new discharge mode, the change in the Ne emission intensity including the discharge characteristics is measured and the corresponding mechanism is also analyzed. As a result, it is found that a color gamut area is expanded by approximately 8.5 % in comparison with a conventional case.

P‐65: White Color Balancing using New Luminance Compensation Driving Method in AC PDP

AbstractThe new driving method is proposed based on the luminance compensation against subfield variation for balancing the white color in an AC PDP. The luminance ratio among the red, green, and blue light can be controlled independently by applying the different auxiliary address pulses to the red, green, and blue cells during a sustain‐period. As a result, the minimum perceptible white color difference (Δuv < 0.002) with respect to the reference white color at SF5 is obtained irrespective of the variation in the subfield from SF1 to SF8.

P‐64: Improvement of Color Temperature Using Address Voltage Pulse During Sustain Period of AC‐PDP

AbstractA new driving technique of applying the auxiliary pulses to only the address electrodes with the blue phosphor layers during sustain‐period is proposed to improve the color temperature of an AC‐PDP. This auxiliary pulses can increase the intensity of blue light, such that the color temperature of an AC‐PDP can be improved without any modification of cell structure and degradation of image quality.

Influence of nonlinear coupling of pulses on spatio-temporal compression

Properties of a novel configuration of an optical (spatio-temporal) pulse compressor, that is based on a Kerr-type planar waveguide into which two pulses are simultaneously launched, are studied. It is assumed that the pulse which is the subject of the compression propagates in the anomalous dispersion regime, while the auxiliary pulse is in normal dispersion. The best parameters of the proposed compressor are obtained when duration of the auxiliary pulse is so large that this dispersion can be neglected, while energy of the second pulse is above the threshold of first-order soliton generation. It is observed that in such a configuration the compression occurs simultaneously with the generation of a soliton-like solution. It is argued that the proposed configuration with two simultaneously propagating pulses has advantages over the configuration with a single pulse, namely the maximal compression factor and the optimal length of the compressor is, respectively, more than 3 times larger and, at least, 10 times greater than the corresponding values of the compressor with a single pulse. It is also demonstrated that such a compressor can be considered as a universal device, since its operation depends only slightly on the initial parameters of the pulse subject to the compression.

On the possibility of target plasma ignition under the conditions of inertial nuclear fusion

The thermonuclear gain G for bulk and spark ignitions are calculated using a mathematical simulation of thermonuclear combustion in a DT plasma of laser targets for various parameters of the target plasma and (isobaric and isochoric) ignitors. The critical parameters of ignitors at which an effective nuclear burst occurs with G ∼ 100 are calculated. It is shown that a further increase in the temperature and size of the ignitors virtually does not affect the efficiency of DT fuel burnup. Irrespective of the ignition technique, the value of G can be estimated with the help of a simple asymptotic formula. At the same time, the critical parameters of ignitors are determined to a considerable extent by the mode of ignition and by the target parameters. Spark ignition with an isochoric ignitor corresponding to the fast ignition mode is considered in detail. It is shown that the main critical parameter for optimal isochoric ignitors is their thermal energy liberated upon absorption of an auxiliary ultrashort laser pulse. The critical values of this energy are calculated.

Improvement of luminance and luminous efficiency using address voltage pulse during sustain-period of AC-PDP

To improve the luminance and luminous efficiency of a surface-discharge alternate current plasma display panel (ac PDP), auxiliary voltage pulses were applied to the address electrode during a sustain-period. The luminance and luminous efficiency exhibited maximum values at an address voltage of 100 V and pulse width of 1 /spl mu/s. An improved luminance of 21.4% and luminous efficiency of 24% were simultaneously obtained based on the proper adjustment of the widths and amplitudes of the address voltage pulse. Accordingly, the proper control of the amplitudes and pulse widths of the auxiliary address voltage during a sustain-period can improve both the luminance and the luminous efficiency in a surface-discharge ac PDP.

New driving scheme for improving color temperature of plasma display panel

This paper presents a new driving scheme for improving the color temperature of plasma display panel-televisions (PDP-TVs). Auxiliary address pulses, plus sustain pulses applied to sustain electrodes, are applied only to address electrodes with blue phosphor layers during a sustain-period, thereby resulting in increasing the luminance of blue cells among the red, green, and blue cells. When compared with the conventional driving scheme, the proposed driving scheme can improve the color temperature of PDP-TVs without reducing the luminance.

Population transfer through the continuum using laser-controlled Stark shifts

We show, through analysis and numerical modeling of hydrogen and sodium, that it should be possible to transfer atomic population, with high probability, using a delayed-pulse two-photon Raman transition in which intermediate states are in the ionization continuum. We propose using auxiliary laser pulses to overcome dynamic Stark shifts that would otherwise prevent population transfer. We find that, even without such auxiliary pulses, population transfer can be improved by tuning the carrier frequencies away from the two-photon Raman resonance condition. Our computations for hydrogen predict nearly 85 percent population transfer.

Intensified cavitation produced with pressure release and rigid ellipsoidal reflectors.

An underwater bubble is well known to grow in response to a strong negative acoustic pulse and then collapse because of inertial forces. Here it is shown that adding an auxiliary positive pulse after collapse begins intensifies the collapse. The negative‐then‐positive pulse sequence is produced by two ellipsoidal reflectors, each with an electrical spark at its near focus f1 and beamed so that they share a common second focus f2. The negative pulse is produced by a polyurethane (pressure release) ellipsoid, the positive by a brass (rigid) ellipsoid. A timing circuit controls the delay between the pulses. Cavitation is recorded by pitting (caused by bubble collapse) of an aluminum foil membrane, which is centered at f2 and lies coplanar with the two crossed beams. When the brass reflector is fired alone, a narrow path of ∼1‐mm diameter pits appears. Firing the polyurethane reflector alone yields more widespread, ∼0.1‐mm diameter pits. When both are fired, a pitted X pattern shows the position of the two be...

In Situ Membrane Resistance Measurements in Polymer Electrolyte Fuel Cells by Fast Auxiliary Current Pulses

A solid‐state current pulse generator for in situ membrane resistance measurements by superimposed square current pulses in polymer electrolyte fuel cells was designed and built. The choice of the measuring technique and of parameters of the instrumentation was based on a critical analysis of the relevant electrochemical and physical processes. The inductance of the current pulse path is very low (≈5 nH), because the last stage of the generator is directly attached to the fuel cell. This low inductance permits the generation of 5 A pulses with extremely fast (decay time ≤5 ns) trailing edges (accompanied by a moderate ringing), which in turn makes it possible to measure the voltage transient induced by the current decay, with gigahertz resolution. The voltage transient is analyzed in a time window of 200 to 700 ns after the end of the pulse. By measurements in this time window, it is possible to separate accurately the ohmic series resistance of the cell (membrane resistance) from the other overpotentials at the electrochemical interfaces. Because the pulse current path is independent of the dc loop, the resistance can be measured independently of the dc value, i.e., at open circuit and under high current density conditions. The instrument was tested, and the results were analyzed for accuracy. Resistances down to 2 mΩ can be measured with an error of <5%. The influence of the pulse length and pulse amplitude on the cell voltage response was also investigated. For cell resistances in the order of few milliohms, a current pulse amplitude of 5 A is the minimum requirement for accurate measurements.

Hemispherical ion acoustic solitons

Hemispherical solitons are studied experimentally using a double-plasma device provided with a hemispherical dividing screen. Their properties are compared with those of spherical solitons and differ appreciably. Auxiliary pulses appear behind the soliton, each propagating faster than the soliton but eventually approaching the soliton speed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Multifunctional pulse sequence generator for pulse NMR

A new multifunctional pulse sequence generator has been designed and constructed. It can conveniently generate various pulse sequences used in nuclear-magnetic resonance (NMR) to measure the spin-lattice relaxation time T1, the spin–spin relaxation time T2, and the spin-locking relaxation time T1 ρ. It can also be used in pulse Fourier transform NMR and double resonance. The intervals of pulses can increase automatically with sequence repetitions and the generator can be used in two-dimensional spectrum measurement and spin-density imaging research. The sequences can be generated through four different triggering methods and there are two synchronous pulse outputs and fifteen auxiliary pulse outputs, so the generator can be conveniently interfaced with a computer or other instruments. The circuitry, functions, and features of the generator are described in this article.

The Vernier Delay Unit

This module will accept differential ECL pulses from the auxiliary rear panel or NIM level pulses from the front panel. The pulses are produced at the output with a fixed delay that is software programmable in steps of 0.1 ns over the range of 0.1 to 10.5 ns. Multiple outputs are available at the front panel. Minimum delay through the module is 9 ns.

Development of an ion implanted bubble device with 4 µm period

A 4 μm period ion implanted bubble device has been developed employing 1 μm bubble single layer film. The design and characterization of a transfer-in gate are described. The effect of the pulse shape on operating margins has been investigated, and an auxiliary pulse added to the transfer pulse to greatly improve gate performance. This newly designed transfer-in gate has also been successfully operated as a bidirectional transfer gate. In order to decrease the access time of large capacity chips, a highly efficient method of detection at high frequencies has been devised. Characterization of the device at 300 kHz is presented.

Non-interaction of transverse phonons with free electrons

By calibrating the phonon detectors with an auxiliary second sound pulse in superfluid helium, we could verify that transverse heat pulses propagating in InSb suffer no attenuation from the free electrons.

Cycloconverter Control Circuits

Cycloconverter control circuitry is discussed using examples from a practical three-phase to single-phase circulating current free cycloconverter. The voltage biased cosine wave technique is used for phase control. Phase-forward and phase-back limit (PBL) pulses are superimposed on each cosine wave. Spurious gating pulses in the range 180° to 360° are suppressed. A new current zero detector is presented involving continuous monitoring of the voltage across each thyristor. Two types of circulating current elimination logic are used, suitable for 1)resistive and lagging loads, and 2)leading, resistive, and lagging loads. Auxiliary gate pulses are supplied to the incoming converter to prevent large gaps in the load current waveform.

A Programmed Digital IC Pulse Generator for Transient NMR Spectrometry

A pulse pattern generator for NMR spectrometry using SGS micrologic IC's for the logic and counters is described. Time intervals between pulses, gate times controlling the number of pulses in a sequence, and delay times controlling the sequence repetition rates are all digitized. Auxiliary pulse outputs to use as suppression pulses, for controlling delay lines, and for gated signal averaging devices are provided. The pulse sequences are those most commonly used in relaxation times measurements, including T1ρ. The generation of further sequences and the possibilities of using the flexible logic of this apparatus for extending its use are discussed.

Modification of a Time-of-Flight Mass Spectrometer for Investigation of Ion-Molecule Reactions at Elevated Pressures

Extensive modifications of a Bendix time-of-flight mass spectrometer have been accomplished to permit investigation of ion-molecule reactions at ion source pressures up to about 1 Torr. In contrast with previous attempts to operate a TOF mass spectrometer, the present method employs a continuous electron beam and a dc extraction field in an ion source similar to those used in magnetic mass spectrometers. The master pulse initiating the timing cycle for mass analysis is applied to a focus grid in the low pressure region external to the source chamber and an auxiliary positive blocking pulse is applied to limit the sampling region during the ``on'' cycle. This modification eliminates degradation of instrument performance resulting from charge exchange and other secondary processes during ion acceleration, thereby extending the pressure range over which the ion source is operable by about two orders of magnitude and simultaneously increasing significantly resolution at moderate pressures. Additionally, a novel dual-inlet sample handling system which monitors directly and controls ion source pressure is described. Details of source design and performance are given, and it is demonstrated that kinetic data obtained using this system are in good agreement with previous results.