Improved cavity ring down spectroscopy is provided by binning decay time vs. wavelength data into wavelength bins defined by discontinuities in a wavelength monitor signal. Average decay times and average wavelengths are computed for each bin. The optical loss of a target analyte at the average wavelengths is determined from the corresponding average decay times.

Molecular absorption spectroscopy is a technique that uses the interaction of energy with a molecular species to qualitatively and/or quantitatively study the species, and/or to study physical processes associated with the species. The interaction of radiation with matter can cause redirection of the radiation and/or transitions between the energy levels of the atoms or molecules. The transition from a lower level to a higher level with an accompanying transfer of energy from the radiation to the atom or molecule is called absorption. When molecules absorb light, the incoming energy excites a quantized structure to a higher energy level. The type of excitation depends on the wavelength of the light. Electrons are promoted to higher orbitals by ultraviolet or visible light, vibrations are excited by infrared light, and rotations are excited by microwaves. The infrared (IR) region is generally considered as extending from just beyond the red visible region (˜0.7 μm to 50 μm). The 0.7 to 2.5 μm region is generally called the near-infrared (NIR), the 2.5 to 15 μm region is referred to as the mid-infrared and the 15 to 50 μm region is called the far-infrared. The wavelengths of IR absorption bands are characteristic of specific types of chemical bonds, and IR spectroscopy finds its greatest utility in the identification of organic and organometallic molecules.
The data that is obtained from spectroscopy is called a spectrum. An absorption spectrum shows the absorption of light as a function of its wavelength. The spectrum of an atom or molecule depends on its energy level structure. A spectrum can be used to obtain information about atomic and molecular energy levels, molecular geometries, chemical bonds, the interactions of molecules, and related processes. Often, spectra are used to identify the components of a sample (qualitative analysis). Spectra may also be used to measure the amount of material in a sample (quantitative analysis). An instrument which measures an absorption spectrum is called a spectrometer.
Gaseous molecules are found only in discrete states of vibration and rotation, called the rovibrational state. Each such state, identified by quantum numbers describing both the vibration and rotation, has a single energy which depends on the quantum numbers. In dipole transitions described above, a single photon of radiation is absorbed, transforming the molecule from one ro-vibrational state to another. As the energies of the ro-vibrational states are discrete, so too are the energies of the transitions between them. Therefore, a photon must possess a specific energy to be absorbed by a molecule to transform the molecule between two given ro-vibrational states. Since the energy of a photon is proportional to the frequency of the radiation, (or equivalently, inversely proportional to its wavelength), only discrete frequencies (wavelengths) can be absorbed by the molecule. The set of discrete frequencies (wavelengths), often called absorption lines, at which a particular species of molecule absorbs, is called the absorption spectrum of a molecule. The width in frequency (wavelength) of each absorption line depends on the specific ro-vibrational transition, the pressure and temperature of the gas containing the molecule, and the presence (or absence) of other types of molecules in the gas. Each species of molecule has a unique absorption spectrum, by which the species of molecule may be identified. Since the energies of different rotational states of a gaseous molecule are typically spaced much more closely than the energies of different vibrational states, then the absorption lines occur in sets, each set corresponding to a single vibrational transition, and many rotational transitions. These sets of absorption lines are called absorption bands.
In the NIR, all the vibrational transitions are harmonics of fundamental, mid-infrared bands. These harmonics can be a hundred to ten thousand times weaker than their mid-infrared counterparts. Standard methods, such as Fourier Transform Infrared Spectroscopy (FTIR), commonly used to characterize mid-infrared transitions, normally have difficulty detecting these weak absorption features in the NIR spectral region. Therefore, more sensitive detection methods are required to measure NIR absorption features. Moreover, because overtone bands and combinations of overtone bands often overlap in wavelength (frequency), the NIR is normally filled with dense bands of absorption lines. It is therefore not uncommon to find spectral regions where the same molecular species has both strong and weak transitions that are co-located in wavelength (frequency). Hence, spectral resolution is very important, especially for near-infrared detection systems.
Measuring the concentration of an absorbing species in a sample is accomplished by applying the empirical Beer-Lambert Law. The Beer-Lambert law (or Beer's law) is the linear relationship between absorbance and concentration of an absorbing species. The general Beer-Lambert law is usually written as:A(λ)=α(λ)L=Cε(λ)L  (1)where A(λ) is the measured absorbance, α(λ) is a wavelength-dependent absorption coefficient, ε(λ) is a wavelength-dependent extinction coefficient, L is the path length, and C is the analyte concentration.
Experimental measurements are usually made in terms of transmittance (T), which is defined as:T=I/I0where I is the light intensity after it passes through the sample and Io is the initial light intensity. The relation between A and T is:A=−log T=−log(I/Io)  (2)
However, modern absorption instruments usually display the data as transmittance, %-transmittance, or absorbance, as a function of wavelength (or wave number). An unknown concentration of an analyte can be determined by measuring the amount of light that a sample absorbs, and then applying Beer's law. Equations (1) and (2) show that the ability of a spectrometer to detect a specific concentration depends not only on the path length through the sample, but also on the intensity noise of both the light source and the detector. Sensitivity can be quantified as a minimum detectable absorption loss (MDAL), i.e., the normalized standard deviation of the smallest detectable change in absorption. MDAL normally has units of cm−1. Sensitivity can also be defined as the achievable MDAL in a one second measurement interval, and has units of cm−1 Hz−1/2. Sensitivity accounts for the different measurement speeds achieved by diverse absorption-based methods and is a figure of merit for any absorption-based spectroscopic technique.
Typically, a spectral feature (called an "absorption peak") of the target species is measured in order to obtain its concentration. Although most species will absorb light at more than one wavelength, the total spectral profile of any particular species is unique. The ability of a spectrometer to distinguish between two different species absorbing at similar wavelengths is called selectivity. Because spectral features narrow as the sample pressure is reduced, selectivity can be improved by reducing the operating pressure. However, the spectrometer must still be able to resolve the resulting spectral lines. Thus, selectivity ultimately depends on spectral resolution. Spectral resolution, typically measured in frequency (MHz), wavelength (picometers) or wave numbers (cm−1), is an important figure of merit for a spectrometer
Optical detection is the determination of the presence and/or concentration of one or more target species within a sample by illuminating the sample with optical radiation and measuring optical absorption by the sample and a wide variety of optical detection methods are known. Most of these methods, however, have limited resolution, and can frequently not achieve sufficient selectivity in spectral measurement. For example, FTIR spectrometers can provide a very broad spectral tuning range but only at the expense of spectral resolution. Many FTIR spectrometers cannot resolve individual rotational lines in an absorption band at low operating pressures (below ˜100 Torr). Non-dispersive infrared (NDIR) instruments have even less resolution that FTIR (typical filters cannot resolve individual rotational lines, let alone absorption bands) but enable inexpensive instruments. Tunable diode laser based absorption spectrometers (TDLAS), can achieve excellent wavelength resolution by finely tuning the laser. However, their precision and accuracy depend on being able to measure, and hence control, the laser wavelength. A TDLAS spectrometer is only as good as its wavelength measuring component. Cavity enhanced optical detection entails the use of a passive optical resonator, also referred to as a cavity, to improve the performance of an optical detector. Cavity enhanced absorption spectroscopy (CEAS) and cavity ring down spectroscopy (CRDS) are two of the most widely used cavity enhanced optical detection techniques. Cavity enhanced methods, like TDLAS depend in resolution on the quality of the wavelength monitoring device and resulting laser control. Both methods, however, provide a significant improvement in sensitivity over traditional TDLAS.
The intensity of single-mode radiation trapped within a passive optical resonator, called the ring-down cavity (RDC), decays exponentially over time, with a time constant τ, which is often referred to as the ring-down time. In practice, it is desirable to ensure that only a single resonator mode has an appreciable amplitude, since excitation of multiple resonator modes leads to multi-exponential radiation intensity decay (i.e., multiple time constants), which significantly complicates the interpretation of measurement results. The ring-down time τ depends on the cavity round trip length and on the total round-trip optical loss within the cavity, including, of course, loss due to absorption and/or scattering by one or more target species within a sample positioned inside the cavity. Thus, measurement of the ring-down time of an optical resonator containing a target species provides spectroscopic information on the target species. Both CRDS and CEAS are based on a measurement of τ.
In CRDS, an optical source is usually coupled to the resonator in a mode-matched manner, so that the radiation trapped within the resonator is substantially in a single spatial mode. The coupling between the source and the resonator is then interrupted (e.g., by blocking the source radiation, or by altering the spectral overlap between the source radiation and the excited resonator mode). A detector typically is positioned to receive a portion of the radiation leaking from the resonator, which decays in time exponentially with time constant τ. The time-dependent signal from this detector is processed to determine τ (e.g., by sampling the detector signal and applying a suitable curve-fitting method to a decaying portion of the sampled signal). Note that CRDS entails an absolute measurement of τ. Both pulsed and continuous wave laser radiation can be used in CRDS with a variety of factors influencing the choice. The articles in the book "Cavity-Ringdown Spectroscopy" by K. W. Busch and M. A. Busch, ACS Symposium Series No. 720, 1999 ISBN 0-8412-3600-3, including the therein cited references, cover most currently reported aspects of CRDS technology.
Single spatial mode excitation of the resonator is also usually employed in CEAS, but CEAS differs from CRDS in that the wavelength of the source is swept (i.e., varied over time), so that the source wavelength coincides briefly with the resonant wavelengths of a succession of resonator modes. A detector is positioned to receive radiation leaking from the resonator, and the signal from the detector is integrated for a time comparable to the time it takes the source wavelength to scan across a sample resonator mode of interest. The resulting detector signal is proportional to τ, so the variation of this signal with source wavelength provides spectral information on the sample. Unlike CRDS, the CEAS technique entails a relative measurement of τ. The published Ph.D. dissertation "Cavity Enhanced Absorption Spectroscopy", R. Peeters, Katholieke Universiteit Nijmegen, The Netherlands, 2001, ISBN 90-9014628-8, provides further information on both CEAS and CRDS technology and applications CEAS is also discussed in a recent article entitled "Incoherent Broad-band Cavity-enhanced Absorption Spectroscopy by S. Fiedler, A. Hese and A, Ruth Chemical Physics Letters 371 (2003) 284-294.
In cavity enhanced optical detection, the measured ring-down time depends on the total round trip loss within the optical resonator. Absorption and/or scattering by target species within the cavity normally accounts for the major portion of the total round trip loss, while parasitic loss (e.g., mirror losses and reflections from intracavity interfaces) accounts for the remainder of the total round trip loss. The sensitivity of cavity enhanced optical detection improves as the parasitic loss is decreased, since the total round trip loss depends more sensitively on the target species concentration as the parasitic loss is decreased. Accordingly, both the use of mirrors with very low loss (i.e., a reflectivity greater than 99.99 percent), and the minimization of intracavity interface reflections are important for cavity enhanced optical detection. Although the present invention will be described primarily in the context of CRDS, it should be understood that the methodology is also applicable to CEAS. In other techniques, called integrated cavity output spectroscopy (ICOS) and off-axis ICOS, the cavity is aligned so as to create a set of densely spaced modes, and with these techniques the method of this invention cannot be used. The present invention relies on the RDC clearly defining a comb of equally spaced modes (having the same transverse mode number and separated by the free spectral range). Such a comb of frequencies does not exist for ICOS cavities.

Method for the precise measurement of the wavelength of light


An integrated optical device includes an electro-absorption modulator disposed on a top surface of an optical waveguide. The electro-absorption modulator includes germanium disposed in a cavity between an n-type doped silicon sidewall and a p-type doped silicon sidewall. By applying a voltage between the n-type doped silicon sidewall and the p-type doped silicon sidewall, an electric field can be generated in a plane of the optical waveguide, but perpendicular to a propagation direction of the optical signal. This electric field shifts a band gap of the germanium, thereby modulating the optical signal.

1. Field
The present disclosure relates to techniques for modulating optical signals. More specifically, the present disclosure relates to an integrated optical device that includes an electro-absorption modulator.
2. Related Art
Silicon photonics is a promising technology that can provide large communication bandwidth, low latency and low power consumption for inter-chip and intra-chip optical interconnects or links. A key component for use in inter-chip and intra-chip optical interconnects is a modulator that can be monolithically integrated into the same silicon layer as transistors and other optical components.
Some approaches for implementing silicon-photonic modulators are based on germanium, which is an efficient absorbing material at infrared wavelengths that include a 1.5 μm band for electro-absorptive modulator applications. For example, for high-performance transistors, a silicon layer can either be strained by the addition of germanium layers or used as a direct, mobility-enhanced silicon-germanium layer.
Consequently, there is considerable interest in integrating alloys of germanium on silicon from both an optical and an electronic perspective. In existing fabrication techniques, germanium alloys are typically produced by direct heteroepitaxial integration using crystal growth at the wafer level. For this reason, germanium is available in many front-end CMOS manufacturing lines and opportunistically provides a manufacturing path for making an electro-absorptive modulator on silicon.
Several approaches have been proposed for making germanium-based modulators that are monolithically integrated on silicon. In some approaches, an silicon-on-insulator (SOI) substrate is used to provide strong confinement of light for optical-waveguide applications in conjunction with germanium integration. The use of a SOI substrate can also be used to fabricate a plurality of wavelength-division-multiplexing optical components to further increase optical communication bandwidth.
Moreover, direct heteroepitaxial integration has been reported for germanium quantum wells and silicon-germanium alloys in surface-normal geometries on bulk silicon substrates to produce quantum-confined Stark effect (QCSE) and Franz-Keldysh (FK) electro-absorption modulators. In principle, electro-absorption modulators, with their wide spectral range of modulation-bandwidth operation, may allow reduced tuning power to be used when aligning the electro-absorption modulators with other optical components in optical links. However, in practice a surface-normal device geometry often requires thick active layers (in order for the light to interact with the silicon-germanium layer). Therefore, very high voltage is typically needed during operation of these optical devices. Furthermore, these optical devices usually are not compatible with the in-plane, edge geometries that are typically used for optical-waveguide operation.
Integrating such a vertical profile on an SOI substrate remains an active area of research. For example, attempts at integrating in-plane FK and QCSE electro-absorption modulators in optical waveguides on SOI substrates are typically complicated and usually have poor performance.
Hence, what is needed is an integrated electro-absorption modulator without the above-described problems.


In the present invention, a masterbatch is produced by melt-mixing a metal compound (B) with a reactive thermoplastic resin (C). The oxidizable polyamide (A) is produced by polycondensing a diamine component containing m-xylylenediamine in an amount of 70 mol % or higher with a dicarboxylic acid component containing adipic acid in an amount of 50 mol % or higher. The metal compound (B) contains at least one metal selected from the group consisting of transition metals in group VIII of the periodic table, manganese, copper and zinc. The reactive thermoplastic resin (C) has an internal bond and/or a reactive functional group which are reactive with an amide bond and/or a reactive functional group of the oxidizable polyamide (A). The masterbatch exhibits a stable moldability. The masterbatch is melt-mixed with an oxidizable polyamide (A) and formed into a molded article which exhibits an excellent oxygen-absorbing ability irrespective of the preservation conditions of the masterbatch.

1. Field of the Invention
The present invention relates to a masterbatch having an excellent processability for producing an oxygen-absorbing molded article having an excellent oxygen-barrier property, and relates to a production method of the oxygen-absorbing molded article made of the masterbatch.
2. Description of the Prior Art
Conventionally, metallic cans and glass bottles have been used as packaging containers capable of inhibiting oxygen from entering thereinto from outside and exhibiting a high ability to store the contents, but have been recently increasingly replaced with plastic packaging containers made of an oxygen-barrier thermoplastic resin in view of its good processability and low costs. As the oxygen-barrier thermoplastic resins, ethylene-vinyl alcohol copolymers and polyamides produced by the polycondensation of a diamine component mainly composed of m-xylylenediamine and a dicarboxylic acid component mainly composed of adipic acid (hereinafter referred to as "nylon MXD6") have been widely used because of their low permeability to gaseous substances such as oxygen and carbon dioxide gas, good processability, sufficient transparency and sufficient mechanical strength. The packaging containers made of metal or glass are substantially free from the permeation of gas into its inside from the outside. In contrast, a non-negligible amount of gas permeates into the inside from the outside in the packaging containers made of the oxygen-barrier thermoplastic resins. The amount of permeated gas increases in some cases according to the conditions for storing the packaging containers made of the oxygen-barrier thermoplastic resin. Therefore, the packaging containers made of the oxygen-barrier thermoplastic resin are poor in the ability to store the contents for a long time, as compared to the conventional metallic cans and glass bottles.
Recently, compositions prepared by adding a cobalt compound to an unsaturated carbon-carbon bond-containing thermoplastic resin such as polybutadiene and polyisoprene or nylon MXD6, compositions prepared by adding a cobalt compound to a mixture of polyamide, polyethylene terephthalate, etc., with an unsaturated carbon-carbon bond-containing thermoplastic resin such as polybutadiene and polyisoprene, and compositions prepared by adding a cobalt compound to a modified resin obtained by introducing an unsaturated carbon-carbon bond to molecular chains of polyethylene terephthalate have been found to exhibit an oxygen absorbing function, and packaging containers using such oxygen-absorbing compositions have now been put into practice. In these packaging containers, since the permeating oxygen from the outside is absorbed by the oxygen-absorbing thermoplastic resin, the amount of oxygen permeating from the outside is apparently considerably reduced. In addition, the oxygen present in the packaging containers is also absorbed by the oxygen-absorbing thermoplastic resin, thereby preventing oxidative deterioration of the contents over a long period of time, and enhancing the ability to preserve the contents as compared to the conventional packaging containers.
There have been conventionally proposed various methods for producing the above oxygen-absorbing thermoplastic resin compositions by adding a transition metal compound to a thermoplastic resin. For example, there are known methods of producing oxygen-absorbing resin compositions by mixing thermoplastic resin pellets containing nylon MXD6 as an oxidizable thermoplastic resin with a solution of a transition metal compound, if required under reflux, and then evaporating the solvent to allow the transition metal compound to adhere to the thermoplastic resin pellets (Japanese Patent Application Laid-Open Nos. 2-500846 and 3-505888). However, the proposed methods require the drying step for evaporating the solvent which entails some danger. Therefore, a special drying apparatus for evaporating the solvent is needed. In addition, it takes a very long time until the drying step is completed, increasing the production costs. In the proposed methods, since the thermoplastic resin pellets carrying the transition metal compound is dried by long-term heating, the oxidation of the nylon MXD6 by the transition metal compound is promoted during the heat-drying, thereby likely to cause the reduction of molecular weight of the nylon MXD6 and the decrease of melt viscosity of the resultant oxygen-absorbing resin composition. This tends to adversely affect various subsequent molding steps to cause molding defects, etc.
Alternatively, there have been proposed a method of producing oxygen-absorbing resin compositions in which a mixture of thermoplastic resin pellets containing nylon MXD6 and a transition metal compound is melt-kneaded in an extruder, etc., extruded into strands, and then pelletized (Japanese Patent Application Laid-Open No. 11-514385). However, in the proposed method, since the molten thermoplastic resin containing nylon MXD6 is kneaded with the metal compound, the oxidation of nylon MXD6 is promoted during the kneading to reduce the molecular weight, thereby likely to reduced the melt viscosity of the resultant oxygen-absorbing resin composition. In some cases, the reduction of molecular weight of the nylon MXD6 may be more significant according to the melt-kneading conditions to lead to a drastic decrease of the melt viscosity of the oxygen-absorbing resin composition. When such an oxygen-absorbing resin composition is subjected to the subsequent molding steps, there tend to occur problems such as molding defect because of uneven melt viscosity.
Not limited to the above methods, in the methods for producing molded articles from the oxygen-absorbing resin composition obtained by melt-mixing an oxidizable thermoplastic resin with a transition metal compound, the oxidizable thermoplastic resin inevitably suffers from oxidative deterioration upon molding, thereby adversely affecting the moldability into products. Also, when allowed to stand in an oxygen-containing atmosphere such as in air, the molecular weight of the oxidizable thermoplastic resin is continuously reduced because of the oxygen absorption by the oxygen-absorbing resin composition. Therefore, the oxygen-absorbing resin composition should be stored until it is used for molding so as to prevent it from coming into contact with oxygen as effectively as possible.

Masterbatch and production method of oxygen-absorbing molded article


A network storage volume stores first entries in a first-mode storage bucket and a second entries in a second-mode storage bucket. The first-mode storage bucket has first bucket metadata, and the second-mode storage bucket has second bucket metadata. A computer-implemented method includes comparing a utilized capacity of the network storage volume to a target capacity information of the network storage volume to obtain a comparison result. Based on the comparison result, at least one bucket is selected to be purged from the buckets of the network storage volume based at least in part on bucket metadata of the buckets. The method further includes causing a purge of the at least one selected bucket from the network storage volume.

Modern data centers often comprise thousands of hosts that operate collectively to service requests from even larger numbers of remote clients. During operation, components of these data centers can produce significant volumes of machine-generated data. The loosely structured and unstructured nature of much of this data has made it challenging to perform indexing and searching operations because of the difficulty of applying semantic meaning to such data. As the number of hosts and clients associated with a data center continues to grow, processing large volumes of machine-generated data in an intelligent manner and effectively presenting the results of such processing continues to be a priority.
Moreover, the infrastructures of various kinds of computing resources, including computer systems, servers, storage systems, network communication devices, or any other electronic resource, of such a data center or information technology (IT) ecosystem typically have characteristics that can be measured. Measuring the characteristics of the computing resources is vital to mitigating instabilities and detecting vulnerabilities. Examples of the characteristics include temperature, utilization, availability, etc. For example, measuring the health of a datacenter's infrastructure, services, service components, backend systems, and various types of application programming interfaces (APIs) is important to enable organizations to proactively monitor, diagnose, and analyze the infrastructure, application, and business metrics of the datacenter.
The performance metrics (e.g., metrics) are useful time-series measurements of computing resources for IT operations and application management. Metrics are used to analyze performance of one or more systems in a domain. Specifically, a metric represents a performance measurement of a computing resource. The metric includes a numerical value indicative of a characteristic of the computing resource measured at a point in time. The numerical value may also be referred to as the "measure" of the metric. In some cases, a metric can represent a data point of a time series of characteristic measurements taken of a computing resource. The numerical value may be a floating point value including any number of decimal values that reflects a precision of that measurement. In some embodiments, the number can be an integer value.
Metrics can be measured at short intervals for multiple applications and/or systems, resulting in large data sets. Metrics measurements can be at the root of everything deployed and managed in at least some known IT environments. From on-premises to cloud deployments, measurements of such metrics enable analysts to understand the availability, performance, and health of mission critical services delivered to end users. Such metrics measurements can provide insights into trends and facilitate a comparison of what is normal and what is not. Existing systems for processing and analyzing metrics data remain inadequate and fail to provide meaningful insights into the health of computing resources.
Metrics can also be helpful in assessing machine-generated data generated by various components in IT environments, such as servers, sensors, routers, mobile devices, Internet of Things (IoT) devices, etc., and for business analytics and security. Analyzing large volumes of machine-generated data has become imperative to obtaining critical insights of systems and their computing resources. However, existing systems for analyzing machine-generated data are incapable of providing insights that benefit from metrics data, which is processed independently by separate systems. As such, analyzing metrics data and/or machine-generated data of computing resources is often difficult, thereby creating a significant cognitive burden on analysts to determine meaningful insights about systems.

This patent is subject to a terminal disclaimer.

Storage volume regulation for multi-modal machine data


A system and method for separating mixed materials employing an angled screen that is moved through a vertically oriented circular path by a single drive element.

The ability to efficiently separate mixed materials, such as household recycling and construction waste, is of increasing importance and economical significance. For example, efficiently extracting and separating various types of recyclable materials from variable mixed waste streams is a critical factor when considering the economic viability of a recycling program. Material Recovery Facilities (MRFs) must be able to separate or sort mixed recyclable materials to a significantly high purity, for example 10 percent. If the final sorted and bailed product, for example similar plastic materials, does not achieve the purity required for purchase on the commodity market at a desired price, the product represents wasted resources and a financial loss for the MFR.
A critical step in the sorting or separation process is the dimensional sorting of materials. Several types of dimensional sorting equipment or separators have been developed, however each of these known types of separators continues to suffer from significant shortcomings. Ballistic-type separators function by rotating an angled surface in a relatively small vertical circle, thereby projecting the mixed materials deposited upon the surface into the air. The materials are separated according to each materials ballistic properties and trajectory created by the movement of the surface.
These types of separators may employ a surface that is unitary or one that is divided into various portions or sections that may move in unison or separately relative to one another. However, in order to achieve the desired motion of the surface, known separators employs a plurality of different motors. For example, different motors may be associated with each of the sides or corners of the unitary surface or with each of the various portions or sections of the surface. An obvious shortcoming of these separators is the increased maintenance associated with the calibration of the multiple motors to achieve the desired movement of the surface.
Another type of dimensional separator employs an angled surface formed of a bank of vertically rotating discs. The discs may have a roughly triangular or irregular shape and may be oriented non-symmetrically along axles or shafts. The axles rotate the discs towards an elevated side of the surface, thereby carrying certain materials up the surface while other materials fall towards the lower side of the surface. One obvious shortcoming of disc-type separators is the increased maintenance resulting from the wear associated with a surface formed of entirely moving parts, e.g. discs, axles, bearing.
Another disadvantage with disc-type separators is a propensity for materials to wrap themselves around and attach themselves to the discs and rotating spaces between the discs. These wrapped materials can lead to decreased throughput and efficiency due to the equipment's down-time required to remove the materials and increased impurities due to the effect of the wrapped materials on the migration of other materials. On disc-type systems employing multiple drive motors, required maintenance may also be undesirably high due to the need to calibrate the efforts of the different motors.
Finally, both of the above types of separator sort small materials or fines by providing voids or holes in the surface through which the fines can pass. The fines pass through the surface and ultimately into a vessel or onto a conveyor belt for transfer. However, known separators suffer from the fact that the fines must fall over equipment structure residing under the surface and above the output vessel or conveyor belt. These structures include drive motors and other moving and often sensitive attachments points of the equipment. This separation technique has the shortcoming of resulting in increased maintenance and repair due to the falling fines contaminating or damaging the components of the separator residing under the surface and above the output.
In view of the above described failures of the known dimensional separators, there exists a significant need in the art for more robust separators having increased efficiency and decreased maintenance and repair costs.


A plurality of reflecting mirrors (322) extending in the vertical direction of a screen are provided in parallel as appropriate between a light incident surface and a light exiting surface. The reflecting mirrors (322) each have a shape of parabolic cylinder, for condensing light on substantially one line. Light rays (L2) are reflected from a concave mirror part on the inner surface of one of the reflecting mirrors (322), and are reflected again from a convex mirror part of an adjacent one of the reflecting mirrors (322), to be emitted to the outside. Being reflected from the inner surface of one of the reflecting mirrors (322), the light rays (L2) are condensed on a predetermined focal point (FP1), and are then emitted while diffusing. Thus obtained is a diffuser panel for a rear projection screen capable of contributing to improved clarity of images.

1. Field of the Invention
The present invention relates to a technique applied to projection televisions, for correcting the direction of travel of light rays projected from the rear side to thereby enlarge the viewing angle of images.
2. Description of the Background Art
A television such as a projection television is constructed such that a rear projection screen corrects the direction of travel of light projected from a projection device so that projected light rays from the whole screen reaches the position of a viewer watching the projection television.
A conventional rear projection screen, by way of example, includes a Fresnel lens sheet as a condensing element and a lenticular lens sheet as a diffusing element, in the direction of travel of light.
Light rays projected from the projection element toward the rear projection screen pass through the Fresnel lens sheet to be made parallel light rays as a whole, and then pass through the lenticular lens sheet.
The lenticular lens sheet has a cylindrical lens formed thereon. The light rays are refracted and diffused when passing through the lenticular lens sheet, and are allowed to have, for example, a directivity in the vertical direction ranging approximately between 10 and 40 degrees at full width at half maximum of light distribution, and a wider directivity in the lateral direction ranging approximately between 30 and 90 degrees at full width at half maximum of light distribution. Such lenticular lens sheet has the function of diffusing light rays in the horizontal direction in which viewers are positioned, so that more people can observe the rear projection screen.
Such rear projection screen is in most cases provided with a Fresnel lens surface on a light exiting side of a Fresnel lens sheet in order to prevent light loss on an unnecessary surface of Fresnel lens teeth.
Such screen is disclosed in Japanese Patent Application Laid-Open No. 2002-196422 (pp. 2–3, FIG. 1), and techniques related to such screen are disclosed in the following Japanese Patent Application Laid-Open Nos: 10-111537 (1998) (pp. 4–5, FIGS. 1 & 3); 2002-311211 (p.5, FIGS. 1–3); 58-163930 (1993) (pp. 3–4, FIG. 2); 2002-174703 (pp. 3–5, FIG. 2); and 9-120102 (1997) (pp. 3–4, FIGS. 1 & 2).
In the above-described rear projection screen, however, a cylindrical lens changes the direction of travel of light rays by refraction, thereby diffusing the light rays. This may cause chromatic aberration due to refractive index wavelength dispersion of a material making up of a lenticular lens sheet, disadvantageously causing an image to take on a different hue when viewed from an angle.
Further, reflected light is inevitably generated, as well as refracted light, at a refracting surface of a lens. Such reflected light disadvantageously causes ghosts and blurred images.

Diffuser panel for rear projection screen and such rear projection screen


The imidazo[1,2-a]pyrimidines given by the following formula [I]:

Japan unexamined patent application 2001-19693 discloses pyrazolo[1,5-a]pyrimidines given by the following formula:
[wherein Z represents O, S, NA2 or a single bond; A1 represents an optionally substituted alkyl, alkenyl, alkynyl, alkadienyl, haloalkyl, aryl, heteroaryl, cycloalkyl, bicycloalkyl or heterocyclic group; A2 represents a hydrogen atom or optionally substituted alkyl, alkenyl, alkynyl, alkadienyl, haloalkyl, aryl, heteroaryl, cycloalkyl, bicycloalkyl or heterocyclic group; m is 0 or an integer of 1 to 4; each of A3's represents independently a halogen atom, alkyl, alkoxy or nitro group; and A4 represents a halogen atom]
It is described that said compounds have excellent fungicidal activity against many kinds of Eumycetes.
Further, with regard to imidazo[1,2-a]pyrimidines which are isomers of pyrazolo[1,5-a]pyrimidines, a kind of imidazo[1,2-a]pyrimidines having herbicidal activity or fungicidal activity are disclosed. [Acta Nat. de l'Ateneo Parmense, 18 (1982) 93, J. Med. Chem. (1975) 8, 1253, etc.] However, the imidazo[1,2-a]pyrimidines having a substituent on the 6-position are not disclosed.
The present invention was made for providing novel imidazo[1,2-a]pyrimidines having excellent activity for controlling plant diseases.

Imidazo[1,2-a]pyrimidine and fungicidal compositions containing thereof

Abstract: [wherein R1 and R2 represent a C1–C6 alkyl group optionally substituted by one or more selected from the group consisting of C1–C4 alkoxy group, C2–C8 dialkylamino group, C1–C4 alkylthio group, C2–C5 alkoxycarbonyl group, cyano group and halogen atoms; or R1 and R2 represent a 3–8 membered heterocyclic group together with the nitrogen atom bonded with R1 and R2; R3 represents a halogen atom or C1–C4 alkyl group; and Ar represents a phenyl group optionally substituted by a halogen atom or atoms; and the like] have excellent activity for controlling plant diseases.


A telecommunications network (10) includes a plurality of telecommunication switches (12). Each telecommunication switch (12) includes a set of processors (14) in order to provide a distributed architecture. A network processor (16) periodically communicates with each set of processors (14) of each telecommunication switch (12) to collect various switch and network information and respond with routing recommendations. These routing recommendations are provided in response to a switch utilization index determined for each telecommunication switch (12). The switch utilization index provides an up to date picture of the in service trunks and a realistic figure of the global load on the processors (14). The switch occupancy index is based on trunks, call attempts, time, and switch type and is defined as the ratio of new call arrival rate to the maximum call arrival rate for a dynamically controlled routing processing cycle.

Telecommunication switches currently in service in a telecommunications network are typically controlled by a generic software which uses a static routing algorithm. The static routing algorithm provides an inflexible method of transmitting telecommunications information from and through the telecommunication switches within the network. A static routing algorithm is typically used within a centralized architecture of telecommunication switches. A centralized architecture uses a central processing scheme to control and operate the telecommunication switches within the network. A centralized architecture using a static routing algorithm allows for a simple calculation of the load on each telecommunication switch, determining a switch occupancy for each switch. However, in a distributed architecture, processors are placed in each switch to operate and control the routing functions for the switch. Switch occupancy and processor load within a distributed architecture becomes a difficult calculation within a multi-processor distributed environment. Therefore, it is desirable to determine a switch occupancy in a distributed multi-processor architecture.

Apparatus and method of determining switch utilization within a telecommunications network


In a beam lithography operation the relative motion between a work piece and the exposure beam produces variations in linear speed at different regions of the work piece surface. For example, if a disk work piece rotates with a constant angular velocity (CAV) relative to the beam, the linear surface speed relative to the beam impact point increases in proportion to increasing radial distance of that point from the center of the disk. To provide uniform exposure dose, the duty cycle of pulses of the exposure beam are varied in accord with radial distance.

Electron beam lithography equipment typically includes a beam column, acting as the generator for producing the exposure beam, and a moveable support table for moving the work piece to be exposed by the beam past the beam. As the surface of the work piece passes under the beam, the beam is modulated to form desired marks on the surface of the disk. Such electron beam lithography equipment, for example, has been suggested for use in forming servo marks on the master for the production of magnetic disks used in hard disk drives. However, application of beam lithography to rotating disk shaped work pieces presents certain problems, as will be discussed below.
A magnetic disk drive, such as a hard disk drive, stores data on one or more disks coated with a magnetic medium. For read/write purposes, the surface of the magnetic medium carries a number of generally parallel data tracks, which on a disk type medium, are arranged concentrically with one another about the center of the disk. An actuator arm positions a transducer or "head" over a desired track, and the head writes data to the track or reads data from the track. As the disk rotates, the actuator arm moves the head in a radial direction across the data tracks under control of a closed-loop servo system, based on position information or "servo data," which is stored within dedicated servo fields of the magnetic medium of the disk. The servo fields can be interleaved with data sectors on the disk surface or can be located on a separate disk surface that is dedicated to storing servo information. As the head passes over the servo fields, it generates a readback signal that identifies the location of the head relative to the center line of the desired track. Based on this location, the servo system moves the actuator arm to adjust the head's position so that it moves toward a position over the desired track and/or a desired location within the track of current interest. Systems for forming the servo tracks on a master for the production of magnetic disks have used both stepped translation mechanisms with laser beams and continuous translation mechanisms with electron beams.
Generally, beam lithography equipment controls the velocity of movement of the work piece under the beam to obtain a desired exposure dose. However, for rotating disk type applications, such as servo mark formation on master disks, it is advantageous to rotate the disk work piece under the beam and to move the disk work piece radially under the beam, during exposure. Assuming the beam remains stationary, the combination of the rotation and radial translation of the disk work piece causes the beam to expose a spiral pattern. In another application (US Publication No. 2004/0001415; entitled Manufacture of Concentric Patterns From Spiral Source), the inventors have developed a technique using cyclical deflection of the beam in synchronization with disk rotation, to convert the spiral pattern to a series of concentric rings. The beam is modulated on and off during such movement of the disk to form a series of desired servo marks along the spiral or along the concentric rings.
During such beam lithography processing of disk work pieces, it is advantageous to rotate the work piece at a constant rotational speed (constant angular velocity—CAV). This provides coherence between successive passes (or tracks). Good coherence, or low track-to-track phase error, is a requirement for good servo track writing so as to support good drive servo performance, for example in disk drive applications.
However, by using CAV during exposure of a rotating disk work piece, the linear velocity of the disk surface at the point under the beam increases proportionally with the radius from the center of disk rotation. Since the linear speed varies with radius, the resulting dosage also varies, since by the beam energy and the linear speed determine the dosage at any given point. As speed increases, the dosage per unit area decreases. Such variation in dosage results in unwanted variation in the feature geometry.
It may be helpful to consider FIG. 11 as an example. The drawing shows a recording disk 101, e.g. a resist coated silicon wafer, having a center opening 103. As the disk 101 rotates and translates relative to the recording beam, the beam is modulated to form servo marks in the photoresist surface, in patterns 105.
The enlarged view of region 107 shows a representative area of the disk work piece, and thereby makes visible a number of the actual marks 109, in a region relatively near the center opening 103. In the region 107, the radial distance from the center of the disk 101 is relatively small. In a similar fashion, the enlarged view of region 111 shows a representative area of the disk, and thereby makes visible a number of the actual marks 113, in a region relatively near the outer edge of the disk 101. In the region 111, the radial distance from the center of the disk 101 is relatively large.
Because the angular rotation rate is constant (e.g. constant RPM), the linear velocity of the disk surface increases at points further from the center of disk rotation. The greater the radius from the center, the greater the circumference at that distance, and the higher will be the linear speed relative to the exposure by the beam. As a result, a greater arc of the disk surface passes under the beam during a unit of exposure time. Any unit of exposed area therefore receives less exposure dose because it is moving faster (because at a greater radius from the center).
FIG. 12 shows the timing of the actual beam-on pulse 115, in relation to the exposed areas 109 and 113 in the regions 107 and 111. The on-time of the beam used to expose each mark is the same, as represented by the high state of the pulse 115. However, as noted above, the linear velocity increases with radius, since the disk 101 rotates at a constant angular velocity during processing. As a result, as the linear speed increases (higher radius), the length of the marks increases (compare 109 to 113). The two different lengths of marks 109, 113 illustrate the linear change in feature length, from outer diameter (OD) to inner diameter (ID), when marks are formed using a constant substrate rotation rate and a constant mark exposure time. Under such a processing scenario, actual exposure dose is effectively stretched over a longer mark area as radius increase. Hence, the exposure dose in a given unit of surface area decreases as radius increases (or the dose in a given unit of surface area increases with decreasing radius).
Like many other beam lithography applications, servo pattern formation on a master for the production of magnetic disks requires uniform exposure doses. That is to say, the exposure dose in any exposed unit of area of the master disk should be held substantially constant across the exposure surface.
It might be possible to vary the electron beam current to compensate for variations in linear velocity. Unfortunately, variation of the beam current adversely affects the spot size and again produces unwanted changes in the recorded feature geometry.
A need therefore exists for a technique to adapt the beam lithography approach, for example using the rotation and translation of the disk work piece, e.g. a resist coated silicon wafer forming a master disk, so that the lithography produces a substantially uniform exposure dosage for marks regardless of the location (e.g. radially) on the disk surface, without causing other unwanted changes in the recorded feature geometry.

Exposure dose control of rotating electron beam recorder


The present invention relates to provided a textile film lamination for use as a wall covering and the like, comprising a fabric layer formed of fire retardant yarn filaments and having a face and back side, a thermoplastic cap film applied to the face of the fabric under heat and pressure, a fire retardant thermosetting or thermoplastic film adhesive on the back of the fabric wherein the fabric retains its fabric-like quality in appearance and tactile feel. The invention retains a weave like look and feel to the fabric while providing a protective clear film on the face surface of the fabric. The invention is suitable for use on wall surfaces in aircraft interiors, rail coach cars, buses, ships, hospitals, public office buildings, sports arenas, hotels, theaters, churches, seniors homes and schools where flammability of the covering material is crucial.

1. Field of the Invention
This invention relates to a fire retardant, high performance fabric lamination for use in high traffic wall covering areas. In particular the present invention provides wall coverings on vertical surface walls within aircraft cabin interiors and other venues where flammability of wall covering material is crucial.
2. Description of the Prior Art
The use of woven and non-woven fabric as a substrate which is supported by plastic laminating materials consisting of resins that encase the fabric and provide smooth plastic like surfaces is known. However the face side of the fabric does not retain its textural characteristics. Webs of reinforcing strands have also been encased in resins to give support to a laminated plastic sheet (see U.S. Pat. Nos. 3,616,130 and 5,773,373).
It is also known to prepare fire retardant material by encapsulating a core fibre in a wrapping or covering to form a heat resistant yarn which may be woven into a heat resistant fabric (see U.S. Pat. No. 4,500,593).
U.S. Pat. No. 4,246,311 is directed to a fire-retardant barrier fabric comprising a polyvinyl/polyvinylidene film including fire retardant material laminated to a scrim woven from high density polyethylene sandwiched between two layers of low density polyethylene material containing fire retardant material.
The known structures do not retain the fabric like quality in appearance and tactual feel while at the same time providing protection for the surface of the fabric for cleaning purposes and giving the fabric added structural support and fire retardation properties.
It is an object of the invention to protect the surface of a fabric, suitable for use as a wall covering and the like and having fire retardant properties, while retaining its fabric like quality in appearance and its tactile feel.
It is a further object of the invention to retain a weave like look and feel to fabric while providing a protective clear film on the face surface of the fabric.
It is a still further object of the invention to provide a fire retardant wall covering fabric suitable for use on wall surfaces in aircraft interiors, rail coach cars, bus ships, hospitals, public office buildings, sports arenas, hotels, theaters, churches, seniors homes and schools where flammability of wall covering material is crucial.
Thus in accordance with the present invention there is provided a textile film lamination for use as a wall covering or the like, comprising a fabric layer formed of fire retardant yarn filaments and having a face and back side, a thermoplastic cap film applied to the face of the fabric under heat and pressure, a fire retardant thermosetting or thermoplastic film adhesive on the back of the fabric wherein the fabric retains its fabric-like quality in appearance and tactile feel. The invention retains a weave like look and feel to the fabric while providing a protective clear film on the face surface of the fabric.
Further features of the invention will be described or will become apparent in the course of the following detailed description.


A power supply circuit is provided for selectively connecting and disconnecting a load from an alternating current power source having neutral and line conductors which comprises a transformer having a primary winding connected to the load and a secondary winding, a relay connected at one terminal thereof to the primary winding and connected at another terminal thereof to the line conductor, a control circuit connected to the relay and operable to open and close the relay, the relay being operable to provide power to the load when closed and to disconnect the line conductor from the primary winding when open, a rectifier circuit connected in parallel with the secondary winding, and an air gap switching mechanism connected to the relay and the control circuit and operable to open the relay when the air gap switching mechanism is activated.

A number of electrical power supply circuits such as wall switch units for lighting fixtures are potentially hazardous to individuals (e.g., repairmen). They comprise an ON/OFF switch or other identified or implied OFF function which most users assume isolates the circuit from the power source when the switch is off. In other words, a user may assume during servicing and maintenance that there are no live parts on the load side of the power supply circuit while the power supply circuit is in the identified OFF mode.
Until recently, safety requirements under Underwriters Laboratories (UL) standard 773 for nonindustrial photoelectric switches for lighting control have not been as stringent as requirements for other electric control circuits in different environments, and most ON/OFF switches and OFF mode identifying functions have been in compliance with UL 773. New safety standards have been devised, however, under the newly proposed UL 773A standard which requires an air gap switch in these types of electrical circuits. The newly proposed UL 773A standard requires that a power supply circuit incorporate either an air gap switch, or a solid-state switching device which restricts leakage currents to 0.5 milliamperes or less back to the load.
U.S. Pat. No. 4,713,598 discloses a power supply circuit 36 which comprises a current transformer XFR to derive operating current, as shown in FIGS. 1A and 1B. The primary winding W1 of the transformer XFR is in series with a switching mechanism SW (e.g., a relay). When the switching mechanism SW is closed, current flows through the primary winding W1 and is induced in the secondary winding W2. Voltage across the secondary winding W2 provides operating power via a power supply 42 (i.e., diode CR1 and capacitor C1) for the control circuitry 44 (i.e., sensor S and amplifier AMP). When the switching mechanism SW is open, the voltage differential for deriving operating current is across the secondary winding W2 to operate a power supply 42.
One of the drawbacks of this design is possible noncompliance with the newly proposed UL 773A safety standard. When the relay SW is open, the device 36 is still electrically connected to the AC source via the capacitor C2 and the secondary winding W2. When analyzed with electronic test equipment, it can be found on some devices that a 2.5 milliamp current flows through the secondary winding W2 of the transformer XFR even though the switching mechanism SW is in the OFF or open position and the load (e.g., a lamp) is no longer energized by the power source. Further, the device 36 does not appear to comprise energy or memory storage means for interrupting the full line to load current path when the load has been opened prior to the device 36 being put in an OFF position by, for example, a slide switch (not shown) or other identified or implied OFF switch. Thus, if the switch SW is a latching relay, and the lamp has burned open, it appears that a repairman could be exposed to full AC line current (e.g., 15 amperes). This is because the power supply circuit in FIGS. 1A and 1B does not provide means for changing the state of the switch SW, that is, no identified or implied OFF switch is provided to either directly or indirectly open the current path to the load. The lamp, therefore, is actually powered on until the relay SW is opened, regardless of whether the slide switch is placed in the OFF position. In addition, current transformers also have a minimum load requirement. Thus, a need exists for a power supply circuit which complies with the newly proposed UL 773A standard.


It is judged whether or not an exchange unit mounted in an image forming apparatus is a genuine one. If judged that a nongenuine unit is mounted there, it is judged at the next step whether not a control parameter is optimized. If judged that the control parameter is optimized, it is judged at the next step whether or not the control parameter is optimized in a local environment. If not optimized in the local environment, an optimal parameter is downloaded from a website.

1. Field of the Invention
The present invention relates to an image forming system, and more particularly to an image forming system having an image forming apparatus in which an exchange unit is exchangeably mounted in a main body thereof.
2. Background Art
An image forming apparatus adapted to allow a user to easily exchange a unit containing consumables or the like has been known.
Meanwhile, in a case where the unit exchanged by the user is other than genuine ones produced by an original manufacturer of the image forming apparatus, the following problems may occur. That is, the capability of the image forming apparatus cannot fully be exerted. For example, picture quality is degraded. Proper operations cannot be ensured. Alternatively, a failure may occur. This is because the image forming apparatus controls the process of forming an image in view of characteristics of toners, those of an image carrier, charging characteristics, cleaning characteristics, and fixing characteristics.
Thus, to maintain the picture quality of an image forming apparatus and to prevent occurrence of problems, JP-A-10-133528 discloses a method of providing in a genuine exchange part a data carrier for holding consumed-amount data of a consumable and of comparing a consumed amount, which is detected by a consumed-amount detection portion provided in a main body of the apparatus, with the consumed-amount data, which is held by the data carrier, to thereby judge whether or not the consumable is supplied to the genuine exchange part.
Further, JP-A-6-149051 discloses the techniques of providing in a toner cartridge storage unit for storing predetermined code data and of inhibiting, when a main body of a copier cannot read predetermined code data from the storage unit, from copying.
Furthermore, JP-A-2001-100598 discloses a method of performing an alarm display and inhibition of printing when empty information written to a cartridge at the detection of a run-out of toner is read from a cartridge replenished with toner.
Also, Japanese Patent No. 2602341 discloses a method of storing the count of generated images in a memory of a cartridge and of making, when a preset termination count representing the number of images, which can be generated by using the cartridge, is equal to the count of generated images, the cartridge unusable thereafter.
Additionally, Japanese Patent No. 3476704 discloses a method of facilitating the detection of nonconformity of a toner replenishment container by setting image forming conditions, which are deteriorated as compared with proper image forming conditions, in a case where it is detected by two-way communication between a container-side communication unit of the toner replenishment container and a main-body-side communication unit of the main body of the apparatus that the toner replenishment container is inadequate, and where it is selected by a selection input unit that a replenishing operation is continued by ignoring the nonconformity of the toner replenishment container.

Image forming system with exchange unit mounted therein


A memory wherein any “disturb effect” can be suppressed in which data in unselected memory cells are lost. This memory has a memory cell array (1) including bit lines, word lines, which are disposed to intersect the bit lines, and memory cells (12) each connected between bit and word lines. In this memory, an access operation, which includes at least one of read, rewrite and write operations, is made to a selected memory cell (12). During this access operation, it is performed to apply to the memory cell (12) a first voltage pulse, which provides an electrical field in a first direction so as to invert a stored data, and a second voltage pulse, which provides as electrical field in the opposite direction to the first one so as not to invert the stored data. In addition, a recovery operation for recovering a residual polarization amount is made to the memory cell (12).

In general, a ferroelectric memory is known as one of nonvolatile memories. Such a ferroelectric memory is disclosed in Japanese Patent Laying-Open No. 2001-210795, for example. This conventional ferroelectric memory is a memory utilizing a pseudo-capacitance change responsive to the direction of polarization of a ferroelectric substance as a memory device. The ferroelectric memory is spotlighted as an ideal memory having both of such an advantage that the same can rewrite data at a high speed with a low voltage in principle and such an advantage that the same is nonvolatile.
FIG. 33 is an equivalent circuit diagram showing a memory cell array of an exemplary conventional simple matrix ferroelectric memory. FIG. 34 is a hysteresis diagram for illustrating operations of the exemplary conventional simple matrix ferroelectric memory. Referring to FIG. 33, a memory cell 501 of the exemplary conventional simple matrix ferroelectric memory is constituted of single ferroelectric capacitors 501a consisting of word lines WL and bit lines BL formed to extend in directions intersecting with each other and ferroelectric films (not shown) arranged between the word lines WL and the bit lines BL.
Operations of the exemplary conventional simple matrix ferroelectric memory are now described with reference to FIGS. 33 and 4. Table 1 shows voltages applied to the word lines WL and the bit lines BL in a read operation and a write operation.
TABLE 1StandbyReadWrite"1"Write"0"Selected WL½ VccVcc0VccUnselected WL½ Vcc⅓ Vcc⅔ Vcc⅓ VccSelected BL½ Vcc0→FloatingVcc0Unselected BL½ Vcc⅔ Vcc⅓ Vcc⅔ Vcc
As the write operation, both ends of the ferroelectric capacitors 501a are at the same potentials in a standby state. When writing data "0", the memory applies a voltage Vcc to a selected word line WL (selected WL) while applying a voltage 0 V to a selected bit line BL (selected BL). At this time, a potential difference Vcc is applied to the ferroelectric capacitors 501a. Thus, the polarization state of the ferroelectric capacitor 501a of a selected memory cell 501 shifts to a point A shown in FIG. 34. When the memory thereafter sets both ends of the ferroelectric capacitor 501a to the same potential, the polarization state of the ferroelectric capacitor 501a makes a transition to "0" shown in FIG. 34. When writing data "1", the memory applies the voltage 0 V to the selected WL while applying the voltage Vcc to the selected BL. At this time, a potential difference −Vcc is applied to the ferroelectric capacitors 501a (see FIG. 33). Thus, the polarization state of the ferroelectric capacitor 501a of the selected memory cell 501 shifts to a point B in FIG. 34. When the memory thereafter sets both ends of the ferroelectric capacitor 501a to the same potential, the polarization state of the ferroelectric capacitor 501a (see FIG. 33) makes a transition to "1" shown in FIG. 34.
As the read operation, the memory first precharges the selected BL to the voltage 0 V, and thereafter brings the same into a floating state. Then, the memory sets up the selected WL to the voltage Vcc. The current potential difference Vcc between the selected WL and the selected BL is capacitance-divided by CFE and CBL assuming that CFE represents the capacitance of the ferroelectric capacitor 501a (see FIG. 33) and CBL represents the parasitic capacitance of the selected bit line BL. The capacitance CFE of the ferroelectric capacitor 501a can be approximated as C0 or C1 depending on held data ("0" or "1"). Therefore, the potential of the selected bit line BL is expressed by the following expressions (1) and (2):V0={C0/(C0+CBL)}×Vcc  (1)V1={C1/(C1+CBL)}×Vcc  (2)
The above expression (1) indicates the potential V0 of the selected BL when data "0" is held, and the above expression (2) indicates the potential V1 of the selected BL when data "1" is held.
The memory performs data reading by determining the potential difference between the bit line potential V0 of the above expression (1) and the bit line potential V1 of the above expression (2) with a read amplifier. Since data of the memory cell 501 is destroyed in this data reading, the memory performs a rewrite operation (restore) responsive to the read data after the data reading.
In the exemplary conventional simple matrix ferroelectric memory shown in FIG. 33, however, it follows that a potential difference of ⅓ Vcc is applied to all unselected memory cells 501 in the write operation and the read operation, and hence there is such inconvenience that the quantity of polarization of the ferroelectric capacitor 501a decreases due to hysteretic properties of the ferroelectric film, as shown in FIG. 35. Consequently, there is such a problem that such a disturbance phenomenon takes place that data are lost from the unselected memory cells 501.

Ferroelectric memory having a refresh control circuit capable of recovering residual polarization of unselected memory cells


A liquid crystal display device includes a signal conversion part (101), a drive pulse generation part (102), a source driver (103), a gate driver (1704), and a multiplexer part (1706). In addition, between the source driver (103) and a display region part (1705) there is provided an intersection part (204) where, when source lines (S1, S2, S3, S4, . . . ) in the display region part are divided into groups each including four source lines, lines that correspond to two source lines (S2 and S3) located the second and third from an end in each group intersect each other. With the liquid crystal display device using the multiplexer part for switching a plurality of source lines in a time-sharing manner, the degradation of the display quality of pixels caused by, for example, an insufficient writing capability to the pixels is improved.

As is well known, liquid crystal display devices have been used in large numbers as the screen display devices for computer devices, for example. In coming years, the liquid crystal display device is expected to expand its range of TV applications. However, a TN (Twisted Nematic) mode, which is currently in wide use, has major display performance problems for use in a TV, such as a narrow viewing angle, an unsatisfactory response time, reduced contrast due to parallax, and blurring of a moving image.
In recent years, the studies on an OCB mode have been advanced in place of the aforementioned TN mode. The OCB has characteristics which provide for a wider viewing angle and a faster response compared to that of TN, and thus it can be said that the OCB is a display mode more suitable for displaying natural moving images.
A conventional liquid crystal display device is described below.
In a display region of a liquid crystal display device, as shown in FIG. 16, source lines 1601 (S1, S2, . . . ), gate lines 1602 (G1, G2, . . . ), and thin film transistors (hereinafter referred to as "TFTs") 1603, serving as switching elements, are provided. A drain electrode of each TFT is connected to a pixel electrode in a pixel 1604. Each pixel 1604 comprises a pixel electrode, a counter electrode, and liquid crystal sandwiched and held between those electrodes. A stray capacitance 1606 is present between the pixel electrode and the source line 1601. For example, the stray capacitance between a source line S2 and a pixel on the left side of the source line S2 is indicated as C2L and the stray capacitance between the source line S2 and a pixel on the right side of the source line S2 is indicated as C2R.
The counter electrode of each pixel 1604 is connected to a counter drive line 1605 and is driven by a counter voltage Vcom.
Next, with reference to FIG. 17, the configuration related to the driving of a conventional liquid crystal display device is described. This conventional liquid crystal display device comprises a signal conversion part 1701, a source driver 1703, a gate driver 1704, a drive pulse generation part 1702 for generating a pulse used for driving each driver, and a display region part 1705 of a liquid crystal panel whose configuration is illustrated in the aforementioned FIG. 16. The signal conversion part 1701 increases the speed of an input image signal by R times at every one horizontal period, R being obtained from R=(N+1)/N, where N is an integer equal to or greater than 1, and converts it to a display signal, which is the image signal whose speed has been increased by R times, and a non-display signal with an R-times speed.
From the signal conversion part 1701, the display signal and the non-display signal are sent to the source driver 1703. The source driver 1703 converts, in accordance with the control of a source driver control signal sent from the drive pulse generation part 1702, the polarity and voltage of the display and non-display signals to an appropriate polarity and voltage for each pixel, and then outputs them as a display signal voltage and a non-display signal voltage.
A multiplexer part 1706 is disposed between the source driver 1703 and the display region part 1705. The multiplexer part 1706 selectively supplies, under the control of a multiplexer control signal sent from the drive pulse generation part 1702, to a plurality of source lines 1601 the display signal voltage and the non-display signal voltage outputted from the source driver 1703 by switching between the source lines in a time-sharing manner.
The gate driver 1704 supplies, in accordance with the control of a gate driver control signal sent from the drive pulse generation part 1702, an ON or OFF potential of the TFT 1603 on the gate line 1602 in synchronization with the output of the display signal voltage or non-display signal voltage from the source driver 1703.
A power supply part 1707 supplies a voltage having a desired polarity and voltage value to each function block in the manner indicated by the dotted lines.
The voltage that is applied to both ends of a liquid crystal cell, such as the pixel 1604 in the display region part 1705, is a difference between the voltage Vcom to be supplied to the counter electrode and the aforementioned display signal voltage or non-display signal voltage to be applied to each pixel 1604 via the source line 1601 and the TFT 1603, and this determines the transmittance of each pixel 1604.
Furthermore, the polarity of the voltage to be applied to both ends of a liquid crystal cell is defined based on whether the difference between the above-described voltage Vcom and the above-described display signal voltage or non-display signal voltage to be applied to each pixel 1604 is positive or negative, and thus is not simply defined by the voltage polarity of the above-described display signal voltage or non-display signal voltage. However, in the following description, for simplicity of description, the polarity of the voltage applied to both ends of a liquid crystal cell will be referred to as the polarity of the above-described display signal voltage or non-display signal voltage.
Such a driving method is similarly employed in both an OCB cell and a TN-type cell. The OCB cell, however, requires a unique driving, which is not required for the TN-type cell, at a start-up stage where an image display is started. The OCB cell has a bend alignment with which an image display can be performed, and a splay alignment with which an image display cannot be performed. To shift from a splay alignment to a bend alignment (hereinafter referred to as a "transition"), a unique driving is required, such as a high-voltage application for a certain time. Note that the driving related to this transition is not directly related to the present invention, and thus any further description is not provided herein.
The OCB cell has a problem in that even if a bend-alignment transition is obtained once by the aforementioned unique driving, if a voltage with a predetermined level or greater is not applied for at least a certain time, the bend alignment cannot be maintained, resulting in a return to a splay alignment (this phenomenon is hereinafter called a "reverse transition").
To suppress the occurrence of a reverse transition, it is known that a high voltage may be applied periodically, as described in Japanese Laid-Open Patent Publication No. 11-109921 and Journal of the Japanese Liquid Crystal Society (Nihon Ekisho Gakkaishi), Apr. 25, 1999 (Vol. 3. No. 2), pp. 99(17)–106(24). This high potential corresponds to the above-described non-display signal voltage. By periodically applying this non-display signal voltage by the driving, as will be described later, the occurrence of a reverse transition can be suppressed. It is common practice to use the maximum voltage of the above-described display signal voltage, which corresponds to a black display, as this non-display signal voltage in view of the effect of suppressing the occurrence of a reverse transition and the display quality. The driving that a high potential is periodically applied to suppress a reverse transition is hereinafter called "CR (Cyclic Resetting) driving".
Typical potential-transmittance curves for OCB are illustrated in FIG. 18.
In FIG. 18, a curve 1801 is a potential-transmittance curve in the case where a predetermined potential for preventing a reverse transition is not inserted, and a curve 1802 is a potential-transmittance curve in the case of CR driving where a predetermined potential for preventing a reverse transition is inserted. A potential 1803 is a critical potential Vth at which a reverse transition from a bend alignment to a splay alignment occurs in the case where a reverse transition is not prevented. A potential 1804 is a potential (white potential) when the transmittance is maximum, and a potential 1805 is a potential (black potential) when the transmittance is minimum. In the case where a reverse transition is not prevented, if the potential is Vth or lower, the alignment returns to a splay alignment, and thus an appropriate transmittance cannot be obtained. Therefore, driving with a potential of Vth or higher is required. In this case, however, as shown in the figure, the transmittance that corresponds to the potential 1803 is the maximum transmittance, and therefore a sufficient luminance cannot be obtained.
Liquid crystals represented by OCB and TN require so-called alternating-current driving. However, any specific configuration of such driving is not described in either the aforementioned Japanese Laid-Open Patent Publication No. 11-109921 or Journal of the Japanese Liquid Crystal Society, and thus what sort of alternating-current reversal should be performed cannot be identified from these references. Hence, as a conventional example, the CR driving performed by a combination of a line-by-line reversal and a frame-by-frame reversal, which is the most typical driving in a liquid crystal display device, is described with reference to FIGS. 19, 20, and 22.
FIG. 19 shows the configuration of the source driver 1703, the display region part 1705, and the multiplexer part 1706 of a conventional liquid crystal display device, shown in the aforementioned FIG. 17. Note that a group of source lines is indicated as "1901" and a group of gate lines is indicated as "1902".
For simplicity, FIG. 19 shows a portion that corresponds to the upper left portion of the multiplexer part 1706, including four source lines and eight gate lines, two outputs indicated by ST1 and ST2 as the output terminals of the source driver 1703, and switching elements in the multiplexer part 1706 only for the four source lines. For the remainder, the same configuration as above is repeated, and thus the illustration thereof is omitted.
As for the display region part 1705, "R", "G", and "B" shown in the pixels indicate color attributes of the pixels, the ensuing number indicates the row number (i.e., the row number of the gate lines) in the display region, and "+" or "−" indicates the voltage polarity that the liquid crystal cell holds in a given one screen.
Reference numeral 1903 indicate multiplexer control signals denoted as CTL0 and CTL1 respectively, and each signal is connected to the gate of each switching element in the multiplexer part 1706, as shown in the figure. The switching element in the multiplexer part 1706 is indicated by a two-digit number following "MP", and the first digit indicates the control signal number and the second digit indicates the number of the source line to which the switching element is connected. In addition, the source and drain of each switching element in the multiplexer part 1706 are connected to the source driver 1703 and a source line, respectively. Each of the outputs ST1 and ST2 of the source driver 1703 is divided in two, and is connected to adjacent source lines via the multiplexer part 1706.
FIG. 20 is a timing diagram illustrating the control performed by a conventional liquid crystal display device. Here, an exemplary operation in the case where N=4 is described. In the figure, SP1 and SP2 are a type of a source driver control signal and are control signals for controlling the polarity of the output voltage of the source driver 1703. In the HIGH period of SP1, the aforementioned display signal voltage or non-display signal voltage, in which ST1 has a positive polarity and ST2 has a negative polarity, is outputted. In the LOW period, a display signal voltage or non-display signal voltage, in which ST1 has a negative polarity and ST2 has a positive polarity, is outputted. SQ1 and SQ2 indicate the type and polarity of the output voltages of ST1 and ST2 of the source driver 1703 which are respectively controlled by the aforementioned SP1 and SP2. Here, "K" indicates the aforementioned non-display signal voltage, "R", "G", and "B" indicate the aforementioned display signal voltages each having a display color attribute, and "+" and "−" indicate the polarity of each voltage. The non-display signal voltage, indicated by "K", indicates the output voltage of the source driver 1703 with respect to a non-image signal that is inserted in the display signal voltage at a rate conversion of R=5/4=1.25 times speed in the signal conversion part 1701.
The "SWP" is another type of a source driver control signal, and is a signal for controlling the output timing of the source driver 1703. By the rise and fall of the SWP's HIGH and LOW logic (indicated by arrows in the figure), the source driver begins to produce an output.
In the HIGH period of CTL0, the switching elements MP10 and MP40 in the multiplexer part 1706 connected to the source lines S1 and S4, respectively, are electrically conducted, and consequently the output of ST1 is supplied to S1 and the output of ST2 is supplied to S4. Then, in the LOW period of CTL0, these supplies are interrupted. Similarly, in the HIGH period of CTL1, the switching elements MP21 and MP31 in the multiplexer part 1706 connected to the source lines S2 and S3, respectively, are electrically conducted, and consequently the output of ST1 is supplied to S2 and the output of ST2 is supplied to S3. Then, in the LOW period of CTL1, these supplies are interrupted.
S1P, S2P, etc., indicate the states of the potentials of the source lines, such as S1 and S2, resulting from the application of the aforementioned display signal voltage and non-display signal voltage to the source lines by the above-described signal voltage control. The symbols "K", "R", "G", "B", "+" and "−" mean the same as those described for SQ1 and SQ2. Note that the number following "K", "R", "G", or "B" indicates the row number of the gate lines.
T01 to T10 indicate one period (one cycle) of R-times speed driving in the case where N=4. When one horizontal period of an input image signal is indicated as 1H, the length of each period is equivalent to NH/(N+1), and 10 cycles are equivalent to 8H.
As for the flow of a signal voltage, for example, the non-display signal voltage of K+ of SQ1 present in the former part of the T01 period is outputted at the time of the rise of SWP at the beginning of this period, and then applied to the electric capacitances (all capacitances belonging to S1, such as, for example, the TFT 1603 and the stray capacitance 1606) of the source line S1 via the switching element MP10 in the multiplexer part 1706 which is electrically conducted while CTL0 is HIGH, whereby S1P takes a non-display signal voltage of the symbol "K+". In the latter part of T01, CTL0 becomes LOW and thus the switching element MP10 in the multiplexer part 1706 on the source line S1 is interrupted, whereby the non-display signal voltage of K+ remains on the source line S1 until the end of the T01 period. In the subsequent former part of the T02 period, the display signal voltage of R+ of SQ1 is applied to the source line S1 in a similar process, and the display signal voltage of R+ remains on the source line S1 until the end of the T02 period. Concurrently, during the period from the latter part of T01 to the former part of T03, the non-display signal voltage of K− on SQ1 and the subsequent display signal voltage of G− are each outputted at the time of the fall of SWP and applied to the source line S2, whereby these voltages each remain on the source line S2 for a predetermined period. Following this, the potential changes in the source lines S1 and S2 are repeated in a similar process for one cycle starting T01 and ending T10. The states of SQ2, S3P, and S4P are similar to the above.
The group of gate lines 1902, shown in FIG. 19, is driven by gate-line drive pulses which are generated by the gate driver 1704 upon receipt of gate driver control signals from the drive pulse generation part 1702. That is, the gate line drive pulses G1P, G2P, . . . , such as those shown in FIG. 21, are applied to the gate lines G1, G2, . . . , respectively. In the period when the ON potential of, for example, the pixel TFT 1603 is exceeded (e.g., the period of TKW and the subsequent high-potential period, shown in FIG. 21), the TFT 1603 of a corresponding pixel 1604 turns to an ON state, and the charging of the source line potential, shown in FIG. 20, (hereinafter referred to as "writing") is performed on the liquid crystal cell.
Here, an example of conventional driving is such that four gate lines G1 to G4 are simultaneously selected in the aforementioned TKW period (i.e., the period which lies 2KNH before T01, shown in FIG. 20, where K is a positive integer and N is 4 in this example), and a non-display signal voltage is written to all pixels on the gate lines G1 to G4. Further, in the time within 4H after a predetermined period {(2K−1)NH}, the display signal voltages of R, G, and B are sequentially written to the pixel cells on each of the gate lines G1 to G4. The subsequent four gate lines G5 to G8 repeat a similar operation after a 4H delay from the gate lines G1 to G4. At this point, the polarity of the potential of the source line is reversed, as shown in FIG. 20. This operation is performed over all gate lines and completed in one frame. As described above, all gate lines in the display region part 1705 are selected twice in one frame period, and a display signal voltage and a non-display signal voltage are each written to the pixels on each gate line once.
In the subsequent frame, in order to reverse the polarity of the pixel voltage, the phases of SP1 and SP2 are shifted 180 degrees. This is the CR driving method, described as a conventional example, which employs a one-column reversal, a four-line reversal, and a frame reversal.
For the control and output operation methods of the source driver, many known modes are available, but such methods are not directly related to the present invention. The same is true of the settings of the aforementioned TKW and the invariable K, which are gate drive conditions, and the setting of N for an R-times speed, a detailed operation, etc. Therefore, any further description thereof is not provided herein.
The display signal voltage and non-display signal voltage can be periodically written by the above-described operation. By appropriately providing the voltage of this non-display signal voltage, a reverse transition of an OCB liquid crystal cell can be prevented.
The above-described driving, however, is associated with the following problems resulting from the fact that the time the non-display signal voltage is applied to the source line from the source driver 1703 is split into the former and latter parts in each period of T01 or T06, or a period which exists 2KNH therebefore or thereafter, and resulting from the open state of the source line occurred during the interruption period of the multiplexer part 1706. The problems are described below with reference to FIGS. 22 and 23.
(a) of FIG. 22 illustrates the transitional state of the potential changes in source lines. The symbols shown in the figure. are the same as those shown in FIG. 20. For example, looking at SQ1, S1P, and S2P in the period T01, when K+ on SQ1 is applied to the source line S1 in the former part of T01, a potential change occurs in S1P in the forward direction (in the figure, the potential change in the forward direction is indicated by an upward arrow).
When K− on SQ1 is applied to the source line S2 in the latter part of T01, a potential change occurs in S2P in the reverse direction (in the figure, the potential change in the reverse direction is indicated by a downward arrow). In the period T06, those potential changes occur in the opposite directions to the above. Similar potential changes occur in SQ2, S3P, and S4P. In practice, even in other periods, potential changes occur resulting from the application of the display signal voltages of R, G, and B to each source line. However, as described above, the voltage value of the display signal voltage is equal to or lower than that of the non-display signal voltage, and changes in a slight degree in accordance with the content of a pixel signal, and thus the influence of such changes is small. Therefore, for simplicity of description, such an influence is not taken into consideration here.
Adjacent source lines are electrically coupled to each other by capacitances connected in series with each other with a TFT drain electrode disposed therebetween, such as, for example, a pair of C1R and C2L and a pair of C2R and C3L, shown in FIG. 16. In addition, each pixel is electrically coupled, by these stray capacitances, to source lines present on both sides of the pixel.
Therefore, the potential change in a source line may possibly exert a comparatively great influence on pixels present on the sides of the source line or on source lines present on the sides of the source line.
The OFF pixel in (b) of FIG. 22 is a pixel to which a display signal voltage or a non-display signal voltage has been written, but the subsequent display signal voltage or non-display signal voltage has not been written. In other words, the OFF pixel is a pixel in which the TFT 1603 is in an OFF state.
As shown in (b1) of FIG. 22, the change of K− in S2P in the latter part of T01 exerts as influence in the reverse direction on all OFF pixels present between the source lines S1 and S2.
In the figure, this is indicated as "influence on OFF pixels", and the polarity of such an influence is indicated by an arrow. In addition, in this period, the source line S1 is in an open state with respect to the multiplexer part 1706. Therefore, the source line S1 which is in an open state in this period receives a similar influence in the reverse direction from the aforementioned OFF pixel. In the figure, this is indicated as "influence on potentials of former open source lines", and the polarity of such an influence is indicated by an arrow. Similarly, the change of K+ in S3P in the latter part of T01 exerts the influence in the forward direction on all OFF pixels present between the source lines S3 and S4, and also exerts the influence in the forward direction on the source line S4 which is in an open state in this period. As for the OFF pixels present between the source lines S2 and S3, because S2P and S3P cause changes in directions opposite to each other, these influences counteract each other, and thus if C2R≈C3L, the influences on these OFF pixels are small. In the figure, a small influence on the OFF pixel is indicated by a black square. As for the OFF pixels present between the source lines S4 and S5, because there are no changes in S4P and S5P, no influence is exerted on the OFF pixels, and thus no particular symbol is provided in the figure.
Although the changes which occurred in the source lines S1 and S4 are superimposed on the write voltages of display signal voltages in the subsequent periods T02 to T05, their polarities are opposite to that of the display signal voltages written thereto, and thus the degree of the influence is evaluated as "−1" and the evaluation rating is provided in (b1) of FIG. 22.
The change of K+ in S1P and the change of K− in S4P in the former part of T01 exert an influence on the source lines S2 and S3 which are in an open state in this period, but immediately after this, the non-display signal voltages of K− and K+ are supplied to the source lines S2 and S3, and therefore such an influence is eliminated at this point and no influence is exerted on the writing of a display signal voltage in any period after T02. Thus, the evaluation ratings to the source lines S2 and S3 in (b1) of FIG. 22 result in "0".
The pixels to which a display signal voltage have been written in T02 remain as OFF pixels after T03 until a non-display signal voltage is written in the next frame. The influence exerted on these pixels from source lines in the meantime is discussed now. Note that such an influence is a repetition of the influence of the periods D to F, shown in FIG. 22, and therefore the degree of the influence is evaluated in these periods.
(b2) of FIG. 22 schematically illustrates the changes in the source lines S1 to S4 caused by the non-display signal voltage during the periods D to F. As shown in the figure, no influence is exerted on the OFF pixels on average during these periods, and thus the evaluation ratings to the source lines S1 to S4 result in "0".
The influence on the pixels for one frame resulting from the writing of a non-display signal voltage is expressed as a sum of the evaluation ratings indicated in (b1) of FIG. 22 and (b2) of FIG. 22. That is, as shown in (b3) of FIG. 22, it can be seen that in the pixels on a source line Sj, which corresponds to j=4i−3 or j=4i, where i=1, 2, 3 . . . , the transmittance becomes higher than the originally intended value (i.e., the luminance is increased). FIG. 23 is a schematic diagram illustrating display images. (a) of FIG. 23 shows the example where the pixels of R, G, and B are operated at an original constant luminance. In this case, an image is obtained which has no display non-uniformity when viewed from an appropriate visual distance, such as that shown in (b) of FIG. 23. In the aforementioned conventional example, however, as the result of an influence such as that shown in (b3) of FIG. 22, the actual image shown in (c1) of FIG. 23 is obtained, based on which a visual image, such as that shown in (c2) of FIG. 23, is obtained. That is, in a conventional example, there is a problem in that vertical lines, such as those shown in (c2) of FIG. 23, are visually recognized by a viewer.
Moreover, in the case of column reverse driving of a conventional example, a voltage range of K+ to K− is required for the source line voltage, and the maximum value of the display signal voltage is equal to or substantially equal to the non-display signal voltage. Therefore, for example, when SQ1 changes from K+ to K− in the period T01 in FIG. 20, or when SQ1 changes from K− to R+ between the periods T01 and T02, an output capability (i.e., slew rate) which is sufficiently great to support short cycles of SP1 and SP2 is required. For this reason, in a conventional case, the charging capability of the source line, i.e., the pixel writing capability, is insufficient sometimes, thereby causing degradation of the display quality of an image.
Stated otherwise, conventionally, an extremely high-cost source driver is required.
Furthermore, a reverse transition in liquid crystal cells of R, G, and B must be prevented with one type of non-display signal for CR driving, and thus there is a limit to the improvement in display quality.
In particular, because recent liquid crystal panels are increased in size and have higher definition, the number of source lines and the number of pixels are increased and stray capacitances are increased because the source line and the pixel become closer to each other. Thus, there is a tendency to worsen the aforementioned interference problem and to cause an insufficient charging time of pixels.
Accordingly, an object of the present invention is to provide a liquid crystal display device capable of displaying high-quality images, by solving the foregoing problems.

Matsushita Electric Industrial Co., Ltd.


Embodiments described herein provide an apparatus for improving deposition uniformity by improving plasma profile using a tri-cut chamber liner. The apparatus also includes a lid assembly having a split process stack for reducing downtime and a bottom heater support for more efficient heating of chamber walls.

Field
Embodiments of the present invention generally relate to an apparatus and method for processing substrates. More particularly, embodiments of the present invention relate to a plasma processing chamber used for dielectric deposition.
Description of the Related Art
Plasma processing, such as plasma enhanced chemical vapor deposition (PECVD), is used to deposit materials, such as blanket dielectric films on substrates, such as semiconductor wafers. A challenge for current plasma processing chambers and processes includes controlling deposition uniformity. A particular challenge includes asymmetries in process volume related to pumping and slit valve geometries and long planned maintenance (PM) downtime exceeding eight hours.
Accordingly, there is a need for an apparatus and process for improving uniformity and reducing PM downtime.

Chamber design for semiconductor processing