A method for preparing isocyanates by the thermal decomposition of carbamates in the presence of a sintered oxide as catalyst under gaseous phase condition. The sintered oxide is composed of at least one element selected from the group consisting of boron, aluminum, silicon, tin, lead, antimony, zinc, yttrium, lanthanum, titanium, zirconium, niobium, tungsten, and iron. The sintered oxide may be composed of at least one element selected from the group consisting of phosphorus, alkali metal element, and alkaline earth metal element.

1. Field of the Invention
The present invention relates to a process for preparing isocyanates in high yield by the thermal decomposition of carbamates in the presence of a catalyst under gaseous phase condition. Isocyanates which have a superior reactivity are useful compounds that are extensively used as a raw material for urethanes, pharmaceuticals, pesticides, etc.
2. Description of the Prior Art
In the industrial field, isocyanates are prepared by reacting amines with phosgene. However, this process requires strongly toxic phosgene. Moreover, a large amount of hydrogen chloride by-products are produced, which corrode a reactor. Therefore, processes for preparing isocyanates without requiring phosgene are strongly demanded.
Among the processes, those by thermal decomposition of carbamates are most commonly proposed, which are roughly classified into two groups: processes carried out in the presence of a catalyst under liquid phase condition, and processes carried out in the presence of a catalyst under high temperature gaseous phase condition.
Examples of the disclosed processes by liquid phase reaction are as listed below: a process wherein a basic catalyst such as alkaline-earth metal and its inorganic compounds is used (Laid-open Japanese Patent application No.54-88201); a process wherein a heavy metal catalyst or heavy metal compounds catalyst is used in an inert solvent (Laid-open Japanese Patent application No.51-19721); a process wherein a metal compound catalyst of at least one element selected from the group consisting of Ib group, IIb group, IIIa group, IVa group, IVb group, Vb group, and VIII group is used in an inert solvent (Laid-open Japanese Patent application No.56-166160); a process wherein zinc chloride is used as a catalyst (Laid-open Japanese Patent application No.57-21356); a process wherein a compound of Tl, Sn, Sb, or Zr is used as a catalyst (Laid-open Japanese Patent application No.58-128354); a process carried out under reduced pressure wherein a metal simple substance or a metal compound of Mn, Mo, W, or Zn is used in a solvent with a high boiling point (Laid-open Japanese Patent application No.2-134355). However, since the catalysts used in these processes are homogeneously dissolved in a reaction solvent, a large amount of energy is required for separating out the catalyst from the decomposition products, and components of the catalyst may be included in the products. Moreover, when the above processes are adopted, the catalyst used in the reaction solvent is difficult to be recovered and re-utilized, and thus the catalyst must be treated as waste product.
For the effective processes to solve the above problems, the processes, wherein a solid solvent which is not dissolved in the reaction solvent under the reaction condition is used, have been proposed.
The disclosed processes are as listed below: a process wherein metal zinc, aluminum, titanium, iron, chromium, cobalt, or nickel is used in the form of enlarged surface area as a catalyst (Laid-open Japanese Patent application No.56-65857); a process wherein one element selected from the group consisting of copper group, zinc group, aluminum group, carbon group (excluding carbon), and titanium group is used in the form of simple substance, oxide, or sulfide (Laid-open Japanese Patent application No.57-158747); a process wherein one element selected from the group consisting of carbon group (excluding carbon), titanium group, vanadium group, and chromium group is used as a catalyst in the form of carbide or nitride (Laid-open Japanese Patent application No.57-158748), and a method wherein a catalyst including boron is adopted (Laid-open Japanese Patent application No.63-211256). However, in the above processes, the catalytic activities are low, and relatively large amounts of catalysts are required. Thus, a yield of isocyanates which is high enough for industrial use cannot be obtained through these processes. Moreover, a large amount of energy is required for separating out and recovering the solvent.
For the processes by gaseous phase reaction, for example, a process wherein thermal decomposition in a gaseous phase is carried out at a temperature in the range of 400.degree. C.-600.degree. C. in the presence of a Lewis acid catalyst (Laid-open Japanese Patent application No.46-17773) is disclosed. However, a large amount of polymeric by-products are produced through the process. Moreover, the thermal decomposition of the catalyst makes the life thereof shorter, and the reactor is corroded. The process also has the problem that the yield of the desired products is low. Another method is also disclosed wherein a reaction in a gaseous phase is carried out under reduced pressure in the presence of a gas permeant packing having a heat resisting property consisting of steel, brass, copper, zinc, aluminum, titanium, chromium, cobalt, nickel, carbon, or quartz (Laid-open Japanese Patent applications No.59-205352, No. 59-205353). The process also has the problem that the yield of the desired product is low. Moreover, since the reaction is carried out under reduced pressure at high temperature of 410.degree. C., high cost is required for the reactor.
As described, the processes for preparing isocyanates wherein solid acid or solid base is used as a catalyst for the thermal decomposition of carbamates under gaseous phase condition have been proposed. However, all of the above processes have the problems of low yield, and a large amount of polymeric by-products or urea compounds. Therefore, the catalyst for gaseous phase reaction for industrial use has not yet been introduced.

Process for preparing isocyanates using sintered oxides


The invention provides a quickly installed and preferably reusable flashing unit for use in roofing or cladding of a building. The flashing is constructed of stainless steel sheet metal for superior corrosion resistance and to withstand rough handling as old roofing material is scraped off the flashing surfaces to prepare it for reuse. The flashing is assembled along joints between assembled flashing components. Each joint includes a resilient gasket between opposing edges of adjacent flashing components. Clips join the components together and resiliently compress the gasket between opposing edges of the adjacent components. After assembly around stacks, openings, edges or other roofing discontinuities, the flashing is incorporated into the roofing in a conventional manner. The invention provides, in its broad aspect, a novel flashing unit for weatherproofing a discontinuity in an external weatherproof membrane, said flashing being assembled along at least one joint, a portion of said joint being covered by said membrane, said flashing comprising: first and second components, each component having an opposing edge disposed at a distance from the opposing edge of the other component, thus defining said joint; gasket means, abutting each said edge, for resiliently sealing said joint; and clamp means, for joining said components and for sealingly compressing said gasket between said opposing edges. Three variations of the gasket and clamp means are described herein.

Flashing is used throughout building construction to weatherproof roofing and other external building cladding membranes around discontinuities such as roof edges, juncture points with walls, around roof penetrations, such as pipes, supports for roof mounted equipment, and stacks which project through the roof.
Conventional flashing is constructed of thin sheet metal which is cut and assembled on site, or may be prefabricated for quick assembly on site. Typically, sheet metal flashing is assembled from components on the building site by spot welding, with snap lock joints, or with self-tapping screws. To complete the required weather seal, the flashing is soldered along exposed joints or sealed with caulking. A cap or counterflashing is assembled to around seal the penetrations at the top of the flashing.
The safe and proper installation of roofing, and other building weatherproofing membranes such as sheet metal external cladding, require favourable weather conditions. The high elevation and exposure to wind make safety a major concern. Wet weather makes surfaces slippery rendering such operations unsafe, introduces undesirable moisture into insulation etc., and impedes the proper bonding of adhesives and bitumen. Cold weather, snow or ice also make operations unsafe, and impractical in many cases. Strong winds lift roofing materials during installation and create safety hazards for workers. In general it is preferable to conduct operations in daylight. Accordingly, there are a limited number of months and limited days of those months where roofing or cladding operations may be carried out economically and safely, especially in northern climates.
As a consequence, the minimization of on site labour is a highly significant factor to achieve rapid installation during favourable weather conditions. Conventional methods of reducing on site labour include the prefabrication of standardized roofing and flashing components. The prefabricated flashing components can then be rapidly assembled on site, saving time and money.
Examples of such prefabricated roof flashing are described in the following prior art. U.S. Pat. No. 4,937,991 to Orth describes a stainless steel sheet metal split flashing that is prefabricated to fit around a pipe extending through a roof. The opposing edges of the prefabricated split flashing are quickly snap locked and lap spliced together on site. However, to complete the weatherproof sealing of the flashing it is necessary to solder the seams together in a conventional manner.
U.S. Pat. No. 280,085 to Sage describes a prefabricated split sheet metal flashing joined together along joints with C-shaped sliding sheet metal clips coacting with bent metal ridges on joint edges of the prefabricated flashing components. Again the only revealed means to seal such flashing is conventional soldering of the joints after assembly, or caulking. U.S. Pat. No. 1,072,199 to Wood and U.S. Pat. No. 3,368,369 to Miller describe similar prefabricated metal flashing assemblies with various interlocking joint features, but utilizing the conventional means of weatherproofing the joints.
A significant disadvantage of using conventional prefabricated flashing is that despite the elimination of on site cutting and fitting, the flashing is still sealed in a labour intensive manner, namely with soldering or caulking. Therefore, when favourable weather allows installation, the amount of labour required to complete the sealing necessary for a weatherproof installation of the flashing remains significant. As well, the level of skill remains high since skilled workers are relied upon to produce a critically important weatherproof seal in the flashing. If the soldering or caulking work is not of consistently high quality, leakage will occur resulting in costly repairs and reworking.
An additional disadvantage in use of conventional metal roof flashing is experienced during roofing repairs or complete reroofing. Conventional metal flashing is typically discarded during reroofing operations since the thin sheet metal is cut and distorted to remove it from the old roof. Although reuse and recycling are becoming more important, the best that can be done with conventional metal flashing after removal is to separate the different metals, such as copper, aluminium, galvanized or stainless steel, and sell them as scrap metal. If the volume of metal is not significant, even such recycling can be uneconomical and impractical. As a result, the old metal flashing is often simply removed and discarded during reroofing. New metal flashing is then installed with the new roof.
A typical flat roof for industrial or commercial buildings lasts about 10 to 15 years before leakage occurs and repairs increase to the point where complete replacement is the most economical solution. In contrast, most building components, and particularly sheet metal components, can have a much longer economical life of fifty or one hundred years if properly maintained. Roofing is also replaced in order to better insulate older buildings by installing rigid insulation on roof decks.
In the life span of a typical industrial or commercial building then, the periodic replacement of a roof, and in particular the removal and replacement of metal flashing can be a significant expense in building maintenance.
Prior to the present invention, reroofing has involved disposal of relatively expensive metal flashing and complete replacement. Since corrosion resistant metal is used such as cooper, aluminium, galvanized or stainless steel, the old metal flashing used is often in good serviceable condition when the bituminous roofing material has deteriorated. The soldering of conventional thin sheet metal flashing and coating with bitumen etc. during roofing makes it necessary to sacrifice metal flashing of good quality in order to replace the rest of the roof which has deteriorated. The waste of uncorroded material and cost of replacing flashing is substantial.
It will be understood that although this description of prior art and the invention is focused on use in built up bitumen roofing construction, the same considerations and scope of the invention relate to any waterproof membrane such as sheet metal wall cladding, or aluminium siding which also use sheet metal flashing assemblies. It will also be understood that the prior art and invention are not restricted to sheet metal flashing but also include spun or extruded aluminium, or molded plastic flashing.
It is desirable therefore to produce a prefabricated flashing which is quickly assembled and facilitates rapid completion of the weatherproof seal, while providing high reliability.
It is also desirable to produce metal flashing that can be reused in order to reduce costs during reroofing operations and to reduce the waste involved.


A Multi-Source electronic lighting device for use as a signal or illuminator. Light is created by a plurality light emitting diode elements which are encapsulated in a light transmitting medium. A curved cylindrical lens is contoured to cooperate with the location of the light emitting diode elements to create a composite light beam with a controlled beam pattern which is elongated in a defined plane. The intensity of the projected light beam is maximized through the efficient collection of created light.

Typical of prior art for a wide angle lighting device would be a circular fresnel lens incandescent lamp combination as can be found on buoy lights used to navigate boats.
In these designs a fresnel or plano-convex lens is formed in the horizontal plane into a circular pattern. The lens is contoured in the vertical plane so that a single focal point is located at the center of the circular pattern. The incandescent lamp is positioned at that focal point resulting in a projected beam pattern which has a 360 degree beamwidth in the horizontal plane and minimal beamwidth in the vertical plane. in effect, the design collects light created by the incandescent source which is emitted at substantial angles above and below the horizontal plane and redirects this light into an intense beam in the horizontal plane. Since the incandescent lamp emits light in a substantially uniform spatial radiation pattern the light collected and projected by the lighting device is substantially uniform in all directions of the 360 degree horizontal beam.
This uniformity is necessary because the lighting device should be equally visible from all directions. Unfortunately, casting the lens usually creates a ridge or parting line on its surface and this parting line obstructs light passing through the lens. A second obstruction is created by wires which are used to support the filament of the incandescent lamp. Both of these obstructions tend to reduce the intensity of the projected beam at one or more locations of the 360 degree horizontal beamspread.
Another prior art design, such as described in U.S. Pat. No. 5,224,773 includes groups of light emitting diode (LED) lamps with lens top bodies assembled in circular formation with their individual concentrated light beams directed radially outward towards the circular lens. These LED lamp assemblies are used as substitutes for the incandescent lamp. These designs are inefficient because they do not collect sufficient percentages of the created light into the required beam pattern. Most of the created light is misdirected due to the bodies of the LED lamps. Also since there is only one focal point, the lens cannot properly redirect the light from each of the plurality of LED lamps.
Finally, these assemblies are enclosed in a chamber of air which has a low thermal conductivity and therefore abets their failure due to overheating.


The present invention discloses a via-hole etching method related to semiconductor manufacturing field, and the method overcomes the defects of an uncontrollable end point of a via-hole and an unfavorable profile-angle in a conventional via-hole etching method. The via-hole etching method includes: forming a structure for via-hole etching, includes: a low-temperature poly-silicon layer, a gate insulating layer, a gate metal layer and an interlayer insulating layer, which are sequentially formed on a substrate; forming a mask layer comprising a via-hole masking pattern on the structure for via-hole etching; by using a first etching process, etching the structure for via-hole etching to a first thickness of the gate insulating layer; by using a second etching process, etching the structure for via-hole etching to etch away the remaining thickness of the gate insulating layer, and uncovering the low-temperature poly-silicon layer; removing the mask layer to form a via-hole structure.

In recent years, as applications of display products become more widely, the studies for display technology also have become more deeply. As a new manufacturing process, LTPS (Low Temperature Poly-Silicon) technology utilizes an excimer laser annealing process to convert an amorphous silicon (a-Si) layer into a poly-silicon (poly-Si) thin film layer. Compared with an amorphous silicon material, a poly-silicon material has increased electron mobility by 100 times or more; therefore, the use of LTPS technology can achieve faster response time, higher resolution and better screen-display quality. Moreover, the use of LTPS technology can reduce integration circuits, simplify periphery of a display device, and implement a narrow-frame technique.
FIG. 1 presents an array-substrate intermediate structure employing LTPS, and as illustrated in FIG. 1, the intermediate structure comprises: a substrate 1, a low-temperature poly-silicon layer 2, a gate insulating layer 3, a gate metal layer 4, an interlayer insulating layer 5 and source-drain via-holes 6, etc. For preparation of the above-described array-substrate intermediate structure, via-holes as illustrated in FIG. 1 are formed, and typically, the etching for the via-holes is accomplished by dry etching or wet etching in a conventional etching method.

CHENGDU BOE OPTOELECTRONICS TECHNOLOGY CO., LTD.


A method and an apparatus for controlling a roll-back prevention device, in which the existence of an open vehicle door is detected and a stationary state of the vehicle is detected. In the present invention, if there is an open vehicle door at the time when a stationary state of the vehicle commences or during a stationary state of the vehicle, the roll-back prevention device will not be activated.

A method and an arrangement for holding a vehicle on an inclined roadway are known from German Published Patent Application No. 195 25 552. In that case, vehicle speed, brake pedal actuation, starting torque, operating state of the vehicle engine, actuation of a parking brake and activation of a holding system are determined. If the holding system has been activated and the speed of the vehicle is below a limit value, the brake force or the brake pressure will be maintained when the brake pedal is actuated and no starting torque is sensed. The brake force is increased when, with the engine switched off, neither the brake pedal nor the parking brake is actuated or when, with the engine switched on, neither actuation of the brake pedal nor a starting torque is detected. The brake force is reduced when, with the engine switched off and the brake pedal not actuated, the parking brake is applied or when, with the engine switched on, a starting torque is sensed. A warning signal can be triggered using a door contact and/or a seat contact.
The features in the preambles of the independent claims are taken from German Published Patent Application No. 195 25 552.

Method and device for controlling a roll-back prevention system


A method and apparatus is provided for forming a printed circuit board or other panel in which an array of vias are arranged in a desired connection grid within one or more layers of the board and then the board and vias are cut to form an edge of the board where a surface of the vias is exposed. The board may be orthogonally mounted on its edge to another thin circuit board or aperture sheet with the exposed surface of each via directly connected to such other board or sheet.

Many applications require the orthogonal, electrical connection of one printed circuit board to other thin circuit boards or aperture sheets suitable for microwave frequencies. Although a number of techniques have been employed in the past for connecting boards together, space considerations, cost and other factors present problems with their use. For example, one common type of connection for mounting two boards perpendicularly to one another involves the use of pin arrays and sockets. One of the boards carries a number of spaced pins and the second board mounts a socket which receives the pins when the two boards are connected together. SMT radio frequency connectors systems are generally similar in construction. Both of these connector systems are relatively large and expensive, and cannot be readily made to the tolerance requirements of many applications.
Flexible or "flex" circuits provide another option of mounting boards perpendicular to one another. Flex circuits are used in a wide variety of applications where an electrical circuit must bend around corners or be flexed during operation. In order to mount two boards perpendicularly to one another, a hard bend must be made in the flex circuit which is subject to fatigue at certain temperature cycles. Flex circuit are also difficult to assemble in many instances, especially in applications with very limited spacing between boards or other components.

Method and apparatus for electrically connecting printed circuit boards or other panels


A design for a wide input common mode voltage comparator is provided which reduces the delay between outputs from component comparators. The wide input common mode voltage comparator includes a first comparator configured to receive a differential input. The first comparator is further configured to accommodate high common mode voltages. The wide input common mode voltage comparator further includes a second comparator configured to receive the differential input. The first comparator is further configured to accommodate low common mode voltages. Additionally, the threshold voltages of the active devices within the comparator are between −100 to 100 mV. Furthermore, the wide input common mode voltage comparator includes a summing circuit configured to receive the outputs of the first and second comparators to create a single-ended output.

The present invention is directed to integrated circuits. More particularly, the invention provides a device and method for comparing voltages. Merely by way of example, the invention has been applied to an wide input common mode voltage comparator. But it would be recognized that the invention has a much broader range of applicability.
Integrated circuits or "ICs" have evolved from a handful of interconnected devices fabricated on a single chip of silicon to millions of devices. Current ICs provide performance and complexity far beyond what was originally imagined. In order to achieve improvements in complexity and circuit density (i.e., the number of devices capable of being packed onto a given chip area), the size of the smallest device feature, also known as the device "geometry", has become smaller with each generation of ICs. Semiconductor devices are now being fabricated with features less than a quarter of a micron across.
Increasing circuit density has not only improved the complexity and performance of ICs but has also provided lower cost parts to the consumer. An IC fabrication facility can cost hundreds of millions, or even billions, of dollars. Each fabrication facility will have a certain throughput of wafers, and each wafer will have a certain number of ICs on it. Therefore, by making the individual devices of an IC smaller, more devices may be fabricated on each wafer, thus increasing the output of the fabrication facility. Making devices smaller is very challenging, as a given process, device layout, and/or system design often work down to only a certain feature size.
An example of such a limit is the performance of a voltage comparator. For example, voltage comparators can be integrated within a variety of integrated circuits. Wide-input common mode voltage comparators often utilize two comparators, an NMOS comparator to accommodate high common mode voltages and a PMOS comparator to accommodate low common mode voltages. The outputs of the two comparators are combined together within a summing circuit to create a single-ended output. However a delay may occur between the outputs of the comparators as a result of the type of circuits used in the NMOS and PMOS comparators.
From the above, it is seen that an improved design for a wide-input common mode voltage comparator is desired.

Wide input common mode voltage comparator


Disclosed is an optical amplifier, wherein efficient optical amplification of signal light of 1.3 .mu.m band is made achievable by optically exiting a doped fiber doped with Pr (praseodymium) alone, or together with other rare earth element, or a similar optical waveguide arrangement, and then supplying the optical waveguide arrangement with the signal light.

1. Field of the Invention
The present invention relates to an optical amplifier capable of efficiently amplifying signal light of 1.3 .mu.m band.
An optical amplifier directly amplifying an optical signal as it is, without converting the optical signal into an electrical signal, is substantially bit rate-free and has such features that it facilitates construction of a large-capacity system and enables multiple channels to be amplified en bloc. Because of such features, intensive studies are being made in various research institutions on the optical amplifier as one of the key devices in the optical communication system for future. As one of the types of such optical amplifier, there is an optical fiber amplifier using a doped fiber, an optical fiber chiefly the core of which is doped with a rare earth element such as Er (erbium). The optical fiber amplifier has such excellent characteristics that it provides high gain, the gain is not dependent on polarization, it produces low noise, and it incurs little connection loss at its connection with an optical fiber as a transmission line. Hence, research on the development of an arrangement suitable for the wavelength of signal light to be amplified is being made in various fields.
1. Description of the Related Art
As an optical fiber amplifier for amplifying signal light of 1.5 .mu.m wavelength band, one using Er as the doping element is well known. This optical fiber amplifier has already reached a status as practicable device exhibiting low noise and highly efficient optical amplification. On the other hand, as an optical fiber amplifier for amplifying signal light of 1.3 .mu.m wavelength band, one using Nd (neodymium) as the doping element is being under development. However, since the fluorescence peak of Nd has a slightly longer wavelength than the 1.3 .mu.m wavelength band, there is a problem with the optical fiber amplifier using Nd as the doping element that a sufficient gain cannot be obtained. Further, it emits light in the vicinity of the wavelength 1.0 .mu.m and this adversely affects the stimulated emission of the 1.3 .mu.m wavelength band. Although there have been made such proposals as to shift the wavelength of the fluorescence peak toward the lower wavelength side by changing the composition of the glass forming the doped fiber or to remove the fluorescent light of 1.0 .mu.m wavelength band by inserting an optical coupler in the device, it is the present state that only a gain around 10 dB can be obtained from it.


This invention relates to toluate ester compositions and their use as solvent, plasticizers, extender and/or diluents in binder formulations, a method of producing such ester compositions, as well as polymer compositions containing such liquid ester compositions. The method of making toluate based esters by reacting methyl-p-toluate with ethylene glycol, diethylene or triethylene glycol, butanediol, etc. More particularly, this invention relates to the mono- or di-ester of methyl toluic acid with a diol containing 2 to 6 carbon atoms that are low viscosity liquids at 25° C. The most common polymer that employs plasticizer is polyvinyl chloride (PVC). Typical amounts of plasticizer in PVC are from about 3 wt. % to about 50 wt. %. Phenolic resins generally require solvents, diluents and/or extenders that reduce the volatility and viscosity of the resin, especially when it is used in building and automotive products. Typical amounts of solvent are from about 5 wt. % to about 65 wt. %.

1) Field of the Invention
This invention relates to liquid toluate-based ester compositions and their use as plasticizers, extenders or diluents in polymer formulations, a method of producing such ester compositions, as well as polymer compositions containing such liquid ester compositions. More particularly, this invention relates to the mono- or di-ester of methyl toluic acid with a diol containing 2 to 6 carbon atoms that are low viscosity liquids at 25° C. This invention also relates to the aforementioned esters modified with long chain hydrocarbon based extenders such as tall oil fatty acids or natural oils. The most common polymer that employs plasticizer is polyvinyl chloride (PVC). Typical amounts of plasticizer in PVC are from about 3 wt. % to about 50 wt. %. Phenolic resins generally require a hydrocarbon solvent/diluent/extenders that reduces the volatility and viscosity of the resin, especially when it is used in building or automotive products. Typical amounts of the aforementioned esters used as solvent/diluent/extender are from about 5 wt. % to about 65 wt. %.
2) Description of Prior Art
Esters derived from benzoic, substituted benzoic and toluic acid with aliphatic alcohols, and the methods for preparation, have been described in the prior art. These esters are primarily used as plasticizers for polymers to facilitate processing and increase flexibility and toughness. Homo- and co-polymers of polyvinyl chloride (PVC) account for the majority of the plasticizer usage. The most common plasticizer, dioctyl phthalate (DOP), has been the subject of negative environmental and toxicological studies and is a high cost additive. Benzoate plasticizers (dipropylene glycol dibenzoate, diethylene glycol dibenzoate) have been introduced as plasticizers but only have moderate compatibility with PVC.
U.S. Pat. No. 2,585,448 to Emerson et al. discloses mixtures of esters prepared by esterifying diols such as diethylene glycol, triethylene glycol with aromatic monocarboxylic acids such as benzoic acid and alkyl substituted benzoic acid. These esters are used as plasticizers.
U.S. Pat. No. 4,656,214 to Wickson discloses diesters having: 1) linear glycols containing from 2 to 8 carbon atoms, 2) a first carboxylic acid of the formula R1R2R3C(O)OH, and 3) a second carboxylic acid of the formula R5C(O)OH, wherein R1 and R2 are individually selected from alkyl containing from 1 to 4 carbon atoms, R3 is hydrogen or alkyl from 1 to 6 carbon atoms, R5 is selected from the group consisting of phenyl, mono- di- and trialkyl-substituted phenyl containing from 9 to 12 carbon atoms and —(CH2)nPh where Ph is phenyl and the value of n is from 1 to 6, inclusive. The esters contain from 16 to 19 carbon atoms and are useful as stain-resistant plasticizers for polyvinyl chloride.
U.S. Pat. No. 5,990,214 to Arendt et al. discloses liquid compositions of mixtures of esters derived from diethylene and triethylene glycol and benzoic or toluic acid. These esters are useful as plasticizers for PVC.
WO 02/083621 to Lang et al. discloses mixed esters prepared in a single step reaction from diols such as diethylene glycol, benzoic acid and an aliphatic acid such as lauric acid. These are liquid at room temperatures and are useful as plasticizers for PVC.
These ester compositions are still slightly volatile, and there is a need for ester compositions with lower volatility than commonly used materials such as dibutyl ester. Also these ester compositions are comparatively expensive and are still somewhat environmental sensitive and toxicological adverse. Thus there is a need for lower cost materials which are less environmentally sensitive and are not toxic.
Phenolic resins, including furan resins and phenolic urethanes, are used as binders for building products, wood products, insulation, foundry materials, abrasives and friction materials. In these formulations hydrocarbon solvents are used as diluents to reduce the viscosity of the phenolic resins. There is a need for diluents that have low volatility, or that can be incorporated into the resin, in order to reduce the Volatile Organic Compound (VOC) level. There is a need for diluents which produce low smoke in foundry applications.
U.S. Pat. No. 4,615,372 to Kopac et al describes a typical phenolic resin binder that contains 45-50 wt. % solvents, usually a mixture of aromatic hydrocarbons and moderately polar solvents.
U.S. Pat. No. 4,293,480 to Martin et al discloses a foundry binder based on a polyol, an isocyanate urethane polymer and a urethane catalyst. Again a polar solvent is used in this composition.
U.S. Pat. No. 6,291,550 to Chen et al discloses a solventless polyurethane no bake foundry binder, using polyether polyol, isocyanate and a urethane catalyst. In this invention, glycol such as triethylene glycol is used as a reactive diluent in the binder.
There is also a need for diluents and solvents that reduce the VOC level in other formulations such as paints, inks, elastomers, adhesives, foundry molding compositions, etc.
There is also a need for low viscosity dye carriers for textiles, polyurethanes, and paper applications which are more economical than existing carriers.

Toluate ester for use as reactive and non-reactive diluent in polymer applications


Provided is a linear motor, including a housing having a receiving space; a vibrator and a stator received therein; an elastic member suspending the vibrator in the housing; and a circuit board. The housing includes a bottom cover and a shell covering the bottom cover and enclosing the receiving space together with the bottom cover. The stator includes an iron core fixed in the housing, a yoke sleeved on the iron core, and first and second coils provided on two sides of the yoke. The second coil is provided between the yoke and the bottom cover. The circuit board is fixed to the bottom cover. The vibrator includes a magnet spaced apart from the stator. The iron core is provided with a groove formed by recessing inwardly from a surface thereof. A coil lead of the first coil passes through the groove to be electrically connected to the circuit board.

With the development of electronic technology, portable consumer electronic products such as mobile phones, handheld game consoles, navigation devices or handheld multimedia entertainment devices, etc., become more and more popular, which generally use vibration motors to do system feedback, such as call reminder, message reminder, navigation reminder of mobile phones, vibration feedback of the game console, etc.
A linear motor in the related art includes a housing having a receiving space, a vibrator, and a stator. The vibrator and the stator are received in the receiving space. The stator includes an iron core, a yoke sleeved on the iron core, a first coil and a second coil. The first coil and the second coil are respectively provided at two sides of the yoke. The vibrator includes a magnet spaced apart from the stator. A magnetic gap is formed between the iron core and the magnet. The first coil and the second coil are inserted into the magnetic gap.
However, with the linear motor of the related art, a coil lead of the first coil is connected to an external circuit after passing through the magnetic gap from outside of the first coil, thereby increasing the space required for the magnetic gap and reducing utilization rate of the space of the magnetic circuit.
Therefore, it is necessary to provide a new linear motor to solve the above drawbacks.


A ladder stabilizing assembly for extension ladders has two length adjustable legs attached to opposing sides of the ladder at substantially the midpoint of the working distance of the ladder and two length adjustable braces attached to opposing sides of the ladder near the bottom and are securely attached to the legs. Rods through the hollow rungs attach the legs and braces to the ladder. Heim joints at one end of each leg and brace attach securely to the rods and enable the legs and braces to pivot and swivel for optimum stability placement. The ladder and stabilizer function as a single unit with a wide four point base. The legs and braces are calibrated to assist in setting the ladder at the standard angle for safe use. The stabilizing assembly prevents the ladder from sliding, tipping or other movement and enables the user to work wearing a safety harness.

Ladder accidents are some of the most preventable in the building and construction industry. There have been a number of devices developed to prevent ladders from being displaced from their setting during use. Many of these attach to the sides of the ladder and provide lateral support. These devices are usually attached to the lower portion of the ladder rails and do not prevent slippage or bending due to weight bearing. Such lateral stabilizers are taught in U.S. Pat. Nos. 6,167,989; 4,147,231; 4,519,477; and 5,423,397.
A European Patent discloses a stabilizer for an extension ladder having laterally extendable side legs of fixed length that are attached to the upper end of the lower segment of an extension ladder with brackets affixed to the outside of the rails. The brackets are U-shaped and have a series of holes permitting the legs to be set at several points along the brackets. Lower braces are also fixed at one end to the ladder using U-shaped brackets that enable the braces to pivot and at the other end to the lower portion of each leg. This system provides only lateral support. (App. No. 84305669.8 to Ralston)
In U.S. Pat. No. 2,574,286, Rein teaches a ladder brace consisting of two backward facing horizontal struts, one end of each being bolted to the inside of the lower ends of each of the rails. The other end of each strut is pivotally connected to a longer support strut with slots along its upper end and a pivoted shoe at the bottom. The slots can be set by cooperation with the lowest rung of the ladder. The slot chosen determines the angle of lean of the ladder which may not conform to present safety standards. This system is not practical with long extension ladders. The supports of Rein are also situated too low on the ladder to provide real stability or to prevent any weight bearing distortion.
Hawkins, in U.S. Pat. No. 4,565,262, teaches a ladder assembly and stabilizer that can be added to an extension ladder using two posts passing through two of the hollow rungs. The upper post is placed near the top of the lower segment of the extension ladder and the lower post is placed near the midpoint of the lower segment. A leg is affixed to each side of the upper post in such a manner that the legs can extend laterally and to the back of the ladder. One of end of a telescoping strut is pivotally attached to each end of the lower post with its other end attached to the approximate midpoint of a leg by means of a hook. There are two cross struts or braces, also telescoping, attached at one end near the top of each leg and at the other end to the midpoint of the leg using the same hook. Each leg can be set at a different angle and the assembly can fold against the ladder rails for storage. Extensions at the end of each leg can be adjusted for uneven terrain. The hook connectors, though enabling a three-point connection, are open and do not appear sufficient to hold the system together under the stress of repeated use.
A ladder stabilizer for step ladders is described by Stewart in U.S. Pat. No. 4,964,488. Brackets are attached to the ladder rails at a point just below the foldable support strut of the ladder and at a point just below the bottom rung on each rail. A leg is attached to each upper bracket by hinges and a brace is similarly attached at one end to a lower bracket and at the other end to a leg. Neither the legs or the braces are adjustable. The hinges permit the legs to swing about an arc of 230° from the plane of the rails around to the front of the opposing rail. The legs cannot extend behind the ladder and appear to provide lateral support only.
Murrell discloses a safety extension ladder having ratcheted extendable legs for adjustment due to uneven terrain and a support system attached to the lower end of the first segment of the ladder. The support system is made up of outriggers having an upper leg and a lower leg that meet at a pivoted foot. The upper leg is pivotally attached below the midpoint of the lower segment of the ladder by means of a bracket bolted to the rail, and the lower leg is pivotally attached to a frame at the bottom of the ladder. The outriggers can rest on the ground at a range of angles as well as to the side and behind the ladder and can also be raised above the ground to support the ladder against a vertical surface. They fold for storage. The outriggers are not adjustable in length and are permanently attached to the ladder and fixed at its lower end. (U.S. Pat. No. 4,632,220)
The ladder stabilizer of Levi et al. as disclosed in U.S. Pat. No. 4,899,849 supports an extension ladder using two height adjustable legs set into U-shaped brackets attached to the outside of the upper end of each rail of the lower segment of the ladder. The brackets fix the angles of the legs at 45° back from the plane of the ladder rails. A brace on each side extends from about the midpoint of each rail to a leg. Neither the angle nor the lengths of the braces are adjustable, thus fixing the angle of incline of the ladder. The braces are located at too high a level to prevent the ladder from sliding backward from the vertical support structure. In a subsequent patent Levi et al. uses side braces attached near the bottom of the rails and a ratcheted leg extension that can be securely set in place to fix the length of the legs. The side braces are foldable but not length adjustable. (U.S. Pat. No. 4,949,809)
Hrincu uses a pivot bar passed through a hollow rung at about the midpoint of a straight non-extendable ladder. Brackets on each side of the pivot bar hold adjustable length legs that provide the support. Crossed struts further enforce the legs. Cords or wires prevent the legs from extending more than a fixed distance back from the ladder. This system appears to be very flimsy and the legs cannot move laterally. (U.S. Pat. No. 6,527,084)
All of the ladder stabilizers that are attached to the ladder by means of brackets bolted to the side rails require the drilling of holes into the rails to attach the brackets. These holes can weaken the rails and damage the integrity of the ladder thereby interfering with the manufacturer's requirements to comply with statutory safety specifications.
There is a need for a ladder stabilizing assembly for extension ladders that is fully adjustable both in the legs and the braces and one that does not require drilling holes into the rails. There is a need for a ladder stabilizing assembly that can be set at the proper angle for safety and can provide support for heavy loads that would cause an unsupported ladder to bend or distort. There is a need for a ladder stabilizing assembly that makes the ladder sufficiently stabile and tip proof so as to enable the user to wear a safety harness while working on the ladder.

Angle configuring stabilizing assembly for extension ladders


A multi-level cluster housing array held together by a skeletal framework formed of octahedron-tetrahedron components.

This invention relates to a framework for enclosing space and more particularly to an octahedron-tetrahedron truss (octet truss}inscribed one within each of a plurality of closely stacked spheres to form multi cluster housing.
The following terms used herein are defined as follows:
Octahedron--A polyhedron having eight equal equilateral triangular plane faces or sides but can be isosceles in form; may be skeletal, as when made of interconnected struts; or continuous, as when made of interlocking or interconnected sheets or plates; or partly skeletal and partly continuous.
Tetrahedron--A polyhedron having four equal equilateral triangular plane faces or sides but can be isosceles in form. Like the octahedron, it may be skeletal, continuous, or a combination of the skeletal and continuous forms.
Octahedron-tetrahedron system--An assemblage of octahedrons and tetrahedrons in face to face relationship. Thus when four tetrahedrons are grouped to define a larger tetrahedron, the resulting central space is an octahedron; together, these figures are comprised in a single, or "common" octahedron-tetrahedron system.
Framework--The frame of a structure for enclosing space, or the frame of a roof, wall or floor; used to distinguish from individual frame components of a roof, wall or floor, so as to denote the whole as distinguished from its parts.
The performance of any building frame is judged by the structural weight needed to shelter a given space. By constructing a frame formed of an octet truss configuration in a sphere, buildings can be erected that greatly reduce the compression components of the configuration over that found in the marketplace. Currently, heavy reinforced concrete compression members are used in multi-level buildings to hold up the structure with little thought being given to the use of tension members.
The disclosed octet truss for use in spheres results in a grid structure that substantially uniformly stresses all of the framework acting almost as a membrane in absorbing and distributing loads. The resulting structure of the disclosed trusses for multi-level cluster housing results in a spidery framework of many lightweight pieces, such as aluminum rods, tubes or extended sections which complement one another in the particular pattern of the finished assembly so as to provide an extremely favorable weight-strength ratio for withstanding high stresses.

Truss framing system for cluster multi-level housing


A tub support kit which can be dismantled and completely removed from the cargo tub of a wheeled vehicle such as a utility trailer or a pickup truck. The kit includes a frame structure which is adapted to rest upright at the rear end of the tub near a drop down tailgate. U-shaped support members extend out over the side walls of the tub and have their rear legs separably connected to the frame structure. Two berth bases overlie the support members and are releasably connected to the U-shaped support members and the frame structure to hold the assemblage together.

Many proposals have been made for converting the cargo tub of a wheeled vehicle into a sleeping facility. The rigid camper shell that is affixed over the tub of a pickup truck represents the simplest from of such proposals. But that approach affords very limited sleeping space--just the cargo space in the tub.
Hence, it has been proposed that the vehicle be modified to accommodate structures that can be erected and expanded to provide larger sleeping quarters. Examples of this type proposal can be found in the following United States patents:
U.S. Pat. No. 2,003,816, granted Jun. 4, 1935 to R. S. Allen, et al. for "Camp Trailer";
U.S. Pat. No. 2,481,230, granted Sep. 6, 1949 to W. B. MacDonald, Jr. for "Vehicle Trailer";
U.S. Pat. No. 4,113,301 granted Sep. 12, 1978 to W. D. Olmstead for "Compact Tent-Type Camping Trailer"; and
U.S. Pat. No. 5,462,330 granted Oct. 31, 1995 to Q. M. Brown for "Folding Camping/Cargo Trailer".
The arrangements disclosed in each of these patents require modification of the vehicle tub to accommodate camping structures. And in the case of the MacDonald, Jr., Olmstead and Brown patents the camping structure is permanently affixed to the vehicle tub significantly interfering with its use for hauling conventional cargo.
There continues to be a need for a camping kit which can be erected on the vehicle tub without modifying the tub and which is completely removable to permit use of the vehicle to haul cargo as originally intended.


An electronics module includes a base and a cover connected to the base. The base includes a recess adapted to receive an associated mounting rail. At least one fixed rail constraining tab is located adjacent a first edge of the recess and is adapted to engage a first flange of the associated mounting rail. First and/or second latch arms are located adjacent a second edge of the recess that is opposite the first edge of the recess. The first and second latch arms are connected to a fixed portion of the second edge and project outwardly relative to opposite lateral sides of the fixed portion. Each of the first and second latch arms includes a rail capture tab. The first and second latch arms are selectively movable resiliently to and from latched and unlatched positions, wherein the rail capture tabs of the first and second latch arms project beyond the fixed portion of the second edge and into the recess when the first and second latch arms are located in their respective latched positions, and wherein the rail capture tabs of the first and second latch arms are withdrawn relative to the fixed portion of the second edge when the first and second latch arms are located in their respective unlatched positions. The cover or other portion of the module defines first and second receiving locations that receive and retain portions of the first and second latch arms when the first and second latch arms are located in their respective latched positions.

It is known to provide an electronics module with an attachment feature for releasably securing the module to a DIN rail, which is an industry standard mounting structure. Known DIN rail attachment features include one or more latches that are manufactured separately from the electronics module and that are movably connected to the module. After being assembled to the module, such latches are manually slidable or otherwise movable between an unlatched position, for connecting/disconnecting the module to/from the DIN rail, and a latched position for fixedly securing the module to the DIN rail. This type of attachment feature is generally effective, but requires the latch(es) to be separately constructed (e.g., injection molded) and then assembled to the module, which increases product cost. In other prior devices, the electronics module includes a base, and a latch is connected to the base as a one-piece molded polymeric construction, wherein one or more flexible webs or members interconnect the latch to the base and accommodate movement of the latch between its unlatched and latched positions. These above-mentioned prior attachment features have not provided sufficient redundant latching, have not provided enough resistance to unlatching in harsh conditions and/or have otherwise been deemed suboptimal.
In light of the foregoing, a need has been identified for an electronics module including an improved DIN rail attachment feature that is defined as a one-piece construction with a base of the module and that provides for redundant latching, superior latching strength, ease of use, and other desirable features and advantages.

Integrated DIN rail attachment feature for superior attachment


A plasma display panel, one of flat panel display device, having improved electrical connections and the driving method thereof are disclosed. The plasma display panel and the driving method thereof have the advantage of diminishing the number of the high voltage driving ICs of high price by effectively constituting the connections of the discharge electrodes to diminish the number of the driving circuits. In addition, since the total scan electrodes are divided into two blocks, and are driven sequentially and alternately from a block to another, the influence of crosstalks by the leakage of the space charge may be diminished by disposing scan electrodes concurrently impressed with voltage signals to be relatively far apart.

1. Field of the Invention
The present invention relates to a plasma display panel and the driving method thereof, and more particularly, to a plasma display panel, one of flat panel display devices, having improved electrical connections and the driving method thereof.
2. Description of the Related Art
Generally, to display an image on a flat panel display device, a matrix driving method is utilized. In this method, a pair of electrodes are sequentially selected among a plurality of scan electrodes arranged in the same horizontal direction as the scanning direction of a video signal and a plurality of address electrodes arranged in the vertical direction, and on the cross point of the pair of the electrodes, a video signal of a pixel can be displayed. In addition, two types of steps are required to display images on a flat panel display device. One step is an addressing step to sequentially address each one of pixels of the display panel, and the other one is a sustaining discharge step to display a video signal for a certain period of time at the corresponding pixel. In the plasma display panel, the two types of steps are carried out by selecting a pair of horizontal and vertical electrodes, and by establishing a negative glow discharge within a discharge space filled with a gas between the two electrodes. In other words, after a pair of scan electrodes and an address electrode are selected according to the sync pulses of a video signal, and a pulse voltage is impressed at least one of the electrodes to establish a gas discharge at the selected pixel, a pulse voltage is impressed across the scan electrodes to achieve a sustaining discharge, and therefore the video signal is transformed to a light signal and is displayed at the selected pixel.
The structural types of the plasma display panels are classified into a facing discharge type and a surface discharge type according to arrangement configurations of discharge electrodes, the driving types of the plasma display panels are classified into an AC driving type and a DC type according to whether the polarity of the voltage impressed for sustaining discharges is varying with the passage of time or not.
FIG. 1a shows a basic structure of a general DC type facing discharge plasma display panel, and FIG. 1b shows a basic structure of a general AC type surface discharge plasma display panel. As shown in FIGS. 1a and 1b, the DC type facing discharge plasma display panel, and the AC type surface discharge plasma display panel are respectively provided with discharge spaces 5 and 15 between front glass substrates 1 and 11 and back glass substrates 7 and 17. In the DC type plasma display panel, since a scan electrode 2 and an address electrode 6 are directly exposed to the discharge space 5, the flow of electrons supplied by a cathode is the energy source sustaining a discharge. In the AC type plasma display panel, since the scan electrodes 12 are embedded in a dielectric layer 13, they are electrically isolated from the discharge space 15. In this case, the discharge is sustained by the well-known wall charge effect. In addition, the AC type plasma display panels are classified into a facing discharge type and a surface discharge type according to the disposition of electrodes establishing discharges.
In the facing discharge plasma display panel, a pixel is addressed by the address electrode 6 on the back substrate 7 and the scan electrode 2 on the front substrate 1 which are disposed to face each other and to be orthogonal to each other and are addressed according to sync pulses of the video signal, and the discharge occurs and is sustained in the discharge space between the electrodes 2 and 6. In the surface discharge plasma display panel, a pair of the scan electrodes 12 formed on the front substrate 11 to be parallel to each other and the address electrode 16 formed on the back substrate 17 to be orthogonal with respect to the electrodes 2 and 6 are provided. In this panel, an address discharge occurs-between the address electrode 16 and the scan electrodes 12, and then a sustaining discharge to display a video signal occurs between two scan electrodes 12, namely, an X electrodes 12a and an Y electrodes 12b. Further, each type may employ 3 electrode structure, 4 electrode structure and so on including a plurality of scan electrodes and/or address electrodes in order to easily establish the discharge.
FIG. 2 shows a schematic exploded perspective view of an AC type 3 electrode surface discharge plasma display panel which is commercially available. An address electrode 16 and a pair of scan electrodes 12 to be orthogonal with respect to the address electrode 16 are disposed at both sides of a corresponding point of a discharge space 15. Partition walls 18 have roles to define discharge spaces 15 and to prevent cross talks between neighbor pixels from occurring by blocking space charges created during a discharge period and ultraviolet rays. To make a plasma display panel capable of displaying color images as a color display device, fluorescent materials 19 which can be excited by ultraviolet rays radiated during a discharge period and respectively emit visible light rays of red, blue, and green colors are respectively coated on the inside surfaces of the discharge spaces sequentially and repeatedly.
Such a plasma display panel coated with the fluorescent materials has to exhibit gray scale to achieve a preferable performance of a color image display device, and a gray scale exhibition method in which a image frame is divided into a plurality of subfields and the panel is driven in a time-division manner is currently utilized. FIG. 3 shows a diagram to explain a gray scale exhibition method of a general AC type plasma display panel. As shown in FIG. 3, the gray scale exhibition method of the AC type plasma display panel employs a method in which a image frame is divided into 4 subfields operated in a time-division manner and 24=16 gray scale can be displayed. The operation period of each subfield consist of respective one of address periods A1 to A4 and respective one of sustaining discharge periods S1 to S4, the fact that the brightness perceived by human eyes is directly proportional to the relative duration of the sustaining discharge period is utilized to exhibit the gray scale. In other words, since the sustaining discharge periods S1 to S4 of a first subfield SF1 to a fourth subfield SF4 are in the ratio 1:2:4:8, combinational periods of each sustaining discharge period such as 0, 1 (1T), 2 (2T), 3 (1T+2T), 4 (4T), 5 (1T+4T), 6 (2T+4T), 7 (1T+2T+4T), 8 (8T), 9 (1T+8T), 10 (2T+8T), 11 (3T+8T), 12 (4T+8T), 13 (1T+4T+8T), 14 (2T+4T+8T), 15 (1T+2T+4T+8T) are possible and therefor 16 level gray scale can be displayed. For example, in order to display level 6 of the gray scale in a certain pixel, the second subfield 2T and the third subfield 4T have to be addressed, and in order to display level 15 of the gray scale, all of the first, second, third and fourth subfields have to be addressed.
FIG. 4 shows a diagram of an electrode connection scheme of an AC type 3 electrode surface discharge plasma display panel to realize the gray scale exhibition method as described above. As shown in FIG. 4, X electrodes 12a of scan electrodes 12 are connected to a common line, and accordingly a voltage signal of the same waveform including a sustaining discharge pulse is impressed to all the X electrodes 12a. Therefore, as a scan signal of the scan electrodes 12 is impressed to an Y electrode, an address discharge occurs between the Y electrode 12b and an address electrode 6, and then as a sustaining discharge pulse is impressed across the Y electrode 12b and the X electrodes, the display discharge is sustained. The waveforms of driving signals respectively impressed to the electrodes connected as described above are shown in FIG. 5.
In FIG. 5, A represents a driving signal to be impressed to each address electrode, X represents a driving signal to be impressed to each common electrode, i.e., X electrode 12a, and Y1 to Y480 represent driving signals respectively to be impressed to Y electrodes 12b. During a total erase period A11, in order to display an exact level of the gray scale, a total erase pulse 22a is impressed to the X electrode 12a to establish a strong discharge, and consequently a wall charge created by the previous discharge is erased, as shown in FIG. 6a, to make the following operation of subfields properly be carried out (the first step). During a total write period A12 and a total erase period A13, in order to lower an address pulse voltage, a total write pulse 23 is impressed to the Y electrode 12b and a total erase pulse 22b is impressed to the X electrode 12a to respectively establish a total write discharge and a total erase discharge, as shown in FIG. 6b and 6c, to control the amount of the wall charge within a charge space 15 (the second and third steps). During an address period A14, a selective 30 charge by an address pulse (a data pulse) 21 across an address electrode 16 and the scan electrode 12b which are orthogonal with respect to each other effects an operation to write, as shown in FIG. 6d, electrically coded information at a selected position of the plasma display panel (the fourth step). During sustaining discharge period S1, a sustaining discharge by a continuous sustaining discharge pulse 25 sustains a display discharge for a given period to display image information on an actual panel.
As described above, in the driving method of the AC type plasma display panel the electrodes of which are connected as shown in FIG. 4, since independent signals are inputted respectively to the Y electrodes 12b and the address electrodes 16 for address discharges as described above and display discharges to display image signals, each electrode requires a separate driving circuit. For example, a plasma display panel having 640xc3x97480 pixels requires one X electrode driving circuit and 480 Y electrode driving circuits, a total of 481 driving circuits for the scan electrodes. Usually, the driving circuit consists of an integrated circuit device incorporated with electronic circuit devices having at least one switch, and the integrated circuit device is referred to as a driver IC. The driver IC requires a high voltage due to the discharge characteristics, and especially since driver ICs used in the X and Y electrodes for display discharges requires a high voltage of about 200 V, it is required to use driver lCs of a very high price. Currently, since the price of the driving circuit portion forms a great part of the total cost of a plasma display panel, it is a decisive obstacles in the commercial success of the plasma display panel. To enhance the marketability of the plasma display panel, it is most important that the number of the driving circuit devices is reduced to lower the cost and the power consumption of the plasma display panel.
To solve the above problem, it is an objective of the present invention to provide a plasma display device having a reduced number of driving circuits for electrodes and a driving method thereof.
Accordingly, to achieve the above objective, there is provided an mxc3x97n matrix plasma display panel having m pairs of scan electrodes having m sustaining electrodes Y1, Y2, . . . , Ym and m common electrodes X1, X2, . . . , Xm which are arranged alternately and in parallel, and n data electrodes arranged to be orthogonal with respect to the m pairs of scan electrodes, wherein while the sustaining electrodes Y1, Y2, . . . , Ym are divided into i groups of electrodes and electrodes in each group are connected to a common line to form i groups of commonly connected Y electrodes, YY1, YY2, . . . , YYi, and the common electrodes X1, X2, . . . , Xm are divided into j groups of electrodes and electrodes in each group are connected to a common line to form j groups of commonly connected X electrodes, XX1, XX2, . . . , XXj, the scan electrodes are connected so that only one pair of an X electrode and an Y electrode among the i group of commonly connected Y electrodes, YY1, YY2, . . . , YYi and the j groups of commonly connected X electrodes, XX1, XX2, . . . , XXj may be arranged to neighbor with each other.
In the present invention, it is preferable that the number of scan electrodes, m, the number of groups of commonly connected Y electrodes, i, and the number of groups of commonly connected X electrodes, j, are in the relation of m=ixc3x97j, and when the number of the sustaining electrodes respectively connected to the groups of the commonly connected Y electrodes YY1, YY2, . . . , YYi is p and the number of the common electrodes respectively connected to the groups of the commonly connected X electrodes XX1, XX2, . . . , XXj is q, the scan electrodes are connected so that p, q, the number of groups of commonly connected Y electrodes, i, and the number of groups of commonly connected X electrodes, j are in the relation of i=q and j=p,) and the first group of the commonly connected Y electrodes, YY1 consists of electrodes Y1, Y2, . . . , Yp commonly connected thereto, the second group of the commonly connected Y electrodes, YY2 consists of electrodes Yp+1, Yp+2, . . . , Y2p commonly connected thereto, the third group of the commonly connected Y electrodes, YY3 consists of electrodes Y2p+1, Y2p+2, . . . , Y3p commonly connected thereto, and similarly, the ith group of the commonly connected Y electrodes YYi consists of electrodes Y(ixe2x88x921)p+1, Y(ixe2x88x921)p+2, . . . , Yip commonly connected thereto, and the first group of the commonly connected X electrodes, XX1 consists of electrodes X1, X1+j, X1+2j, . . . , X1+(qxe2x88x921)j commonly connected thereto, the second group of the commonly connected X electrodes, XX2 consists of electrodes X2, X2+j, X2+2j, . . . , X2+(qxe2x88x921)j commonly connected thereto, the third group of the commonly connected X electrodes, XX3 consists of electrodes X3, X3+j, X3+2j, . . . , X3+(qxe2x88x921)j commonly connected thereto, and similarly, jth group of the commonly connected X electrodes, XXj consists of electrodes Xj, X2j, X3j, . . . , Xqj commonly connected thereto.
Further, in the present invention, it is preferable that when k is an integer, the mxc3x97n matrix plasma display panel consists of kmxe2x80x2xc3x97n matrix having k display units of mxe2x80x2xc3x97n matrix arranged; each of the k display units having the same electrode connection schemes has ixe2x80x2 sustaining electrode groups in each group of which one or pxe2x80x2 neighboring sustaining electrodes are connected to each other; and when, in the k display units, a first display unit is expressed by subgroups of commonly connected Yxe2x80x2(1) electrodes, YYxe2x80x21(1), YYxe2x80x22(1), . . . , YYxe2x80x2ixe2x80x2(1), a second display unit is expressed by subgroups of commonly connected Yxe2x80x2(1) electrodes, YYxe2x80x21(2), YYxe2x80x22(2), . . . , YYxe2x80x2ixe2x80x2(1), and similarly, a kth display unit is expressed by subgroups of commonly connected Yxe2x80x2(k) electrodes, YYxe2x80x21(2), YYxe2x80x22(2), . . . , Yxe2x80x2ixe2x80x2(k), while the groups of commonly connected Y electrodes, YY1, YY2, . . . , YYi of the mxc3x97n matrix, each are expressed by respective subgroups, among the subgroups of the k display unit, a first group YY1 consists of subgroups YYxe2x80x21(1), YYxe2x80x21(2), . . . , YYxe2x80x21(k) commonly connected thereto, among the subgroups of the k display unit, a second group YY2 consists of subgroups Yxe2x80x22(1), Yxe2x80x22(2), . . . , YYxe2x80x22(k) commonly connected thereto, and similarly, among the subgroups of the k display unit, a ith group YYi consists of subgroups Yxe2x80x2i(1), YYxe2x80x2i(2), . . . , YYxe2x80x2i(k) commonly connected thereto.
Furthermore, in the present invention, it is preferable that in the k display units of mxe2x80x2xc3x97n matrix, the subgroups YYxe2x80x21(1), YYxe2x80x21(2), . . . , YYxe2x80x21(k) each consists of Y1, Y2, . . . , Ypxe2x80x2 commonly connected thereto, the subgroups YYxe2x80x22(1), YYxe2x80x22(2), . . . , YYxe2x80x22(k) each consists of Ypxe2x80x2+1, Ypxe2x80x2+2, Ypxe2x80x2+3, . . . , Y2pxe2x80x2 commonly connected thereto, the subgroups YYxe2x80x23(1), YYxe2x80x23(2), . . . , YYxe2x80x23(k) each consists of Y2pxe2x80x2+1, Y2pxe2x80x2+2, Y2pxe2x80x2+3, . . . , Y3pxe2x80x2 commonly connected thereto, and similarly, the subgroups Yxe2x80x2ixe2x80x2(1), YYxe2x80x2ixe2x80x2(2), . . . , YYxe2x80x2ixe2x80x2(k) each consists of Y(ixe2x80x2xe2x88x921)pxe2x80x2+1, Y(ixe2x80x2xe2x88x921)pxe2x80x2+2, Y(ixe2x80x2)pxe2x80x2+3, . . . , Yixe2x80x2pxe2x80x2 commonly connected thereto; and when the number of common electrodes respectively connected to the groups of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x21, XXxe2x80x22, . . . , XXxe2x80x2jxe2x80x2 of the k display units of mxe2x80x2xc3x97n matrix is qxe2x80x2, the first group of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x21 consists of electrodes X1, X1+jxe2x80x2, X1+2jxe2x80x2, . . . , X1+(qxe2x80x2xe2x88x921)jxe2x80x2 commonly connected thereto, the second group of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x22 consists of electrodes X2, X2+jxe2x80x2, X2+2jxe2x80x2, . . . , X2+(qxe2x80x2xe2x88x921)jxe2x80x2 commonly connected thereto, the third group of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x23 consists of electrodes X3, X3+jxe2x80x2, X3+2jxe2x80x2, . . . , X3+(qxe2x80x2xe2x88x921)jxe2x80x2 commonly connected thereto, and similarly, jth group of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x2jxe2x80x2 consists of electrodes Xjxe2x80x2, X2jxe2x80x2, X3j , . . . , Xqxe2x80x2jxe2x80x2 commonly connected thereto, and thus the common electrodes are grouped so that the groups of the commonly connected Xxe2x80x2 electrodes in same order of each display unit may be sequentially or alternately driven.
In addition, to achieve the above objective, there is provided an mxc3x97n matrix plasma display panel having mxe2x80x3+2 scan electrodes and n data electrodes, wherein the 2 outmost electrodes at the one side among themxe2x80x3+2 scan electrodes are provided as preliminary discharge electrodes; while the mxe2x80x3 scan electrodes consist of pairs of mxe2x80x3 sustaining electrodes Y1, Y2, . . . , Ymxe2x80x3 and mxe2x80x3 common electrodes X1, X2, . . . , Xmxe2x80x3, the sustaining electrodes are divided into i groups of commonly connected Y electrodes (Y1, Y2, . . . , Yp), (Yp+1, Yp+2, . . . , Y2p), . . . , (Ymxe2x80x3xe2x88x92p+1, Ymxe2x80x3xe2x88x92p+2, . . . , Ymxe2x80x3), each group consisting of p neighboring electrodes commonly connected thereto, and the common electrodes are divided into j groups of commonly connected X electrodes, (X1, X1+j, X1+2j, . . . , Xmxe2x80x3xe2x88x92j+1), (X2, X2+j, X2+2j, . . . , Xmxe2x80x3xe2x88x92j+2), . . . , (Xj, X2j, X3j, . . . , Xmxe2x80x3), each group consisting of q electrodes commonly connected thereto which each are at (j+1)th position from j common electrodes at one side.
In the present invention, it is preferable that the number of scan electrodes, mxe2x80x3, the number of groups of commonly connected Y electrodes, i, and the number of groups of commonly connected X electrodes, j, are in the relation of mxe2x80x3=ixc3x97j and when the number of the sustaining electrodes respectively connected to the groups of the commonly connected Y electrodes YY1, YY2, . . . , YYi is p and the number of the common electrodes respectively connected to the groups of the commonly connected X electrodes XX1, XX2, . . . , XXj is q, the scan electrodes are connected so that p, q, the number of groups of commonly connected Y electrodes, i, and the number of groups of commonly connected X electrodes, j are in the relation of i=q and j=p. Alternatively, it is preferable that the number of scan electrodes, mxe2x80x3, the number of groups of commonly connected Y electrodes, i, and the number of groups of commonly connected X electrodes, j, are in the relation of mxe2x80x3=ixc3x97j, when k is an integer, a mxe2x80x3xc3x97n plasma display portion of the (mxe2x80x3+2)xc3x97n matrix plasma display panel consists of kmxe2x80x2xc3x97n matrix having k display units of mxe2x80x2xc3x97n matrix arranged; each of the k display units having the same electrode connection schemes has ixe2x80x2 sustaining electrode groups in each group of which one or pxe2x80x2 neighboring sustaining electrodes are connected to each other; and when, in the k display units, a first display unit is expressed by subgroups of commonly connected Yxe2x80x2(1) electrodes, YYxe2x80x21(1), YYxe2x80x22(1), . . . , YYxe2x80x2ixe2x80x2(1), a second display unit is expressed by subgroups of commonly connected Yxe2x80x2(1) electrodes, YYxe2x80x21(2), YYxe2x80x22(2), . . . , YYxe2x80x2ixe2x80x2(2), and similarly, a kth display unit is expressed by subgroups of commonly connected Yxe2x80x2(k) electrodes, YYxe2x80x21(k), YYxe2x80x22(k), . . . , YYxe2x80x2ixe2x80x2(k), while the groups of commonly connected Y electrodes, YY1, YY2, . . . , YYi of the mxc3x97n matrix, each are expressed by respective subgroups, among the subgroups of the k display unit, a first group YY1 consists of subgroups YYxe2x80x21(1), YYxe2x80x21(2), . . . , YYxe2x80x21(k) commonly connected thereto, among the subgroups of the k display unit, a second group YY2 consists of subgroups YYxe2x80x22(1), YYxe2x80x22(2), . . . , YYxe2x80x22(k) commonly connected thereto, and similarly, among the subgroups of the k display unit, a ith group YYi consists of subgroups YYxe2x80x2k(1), YYxe2x80x2k(2), . . . , YYxe2x80x2k(k) commonly connected thereto. Also, in the k display units of mxe2x80x2xc3x97n matrix, the subgroups YYxe2x80x21(1), YYxe2x80x21(2), . . . , YYxe2x80x21(k) each consists of Y1, Y2, . . . , Ypxe2x80x2 commonly connected thereto, the subgroups YYxe2x80x22(1), YYxe2x80x22(2), . . . , YYxe2x80x22(k) each consists of Ypxe2x80x2+1, Ypxe2x80x2+2, Ypxe2x80x2+3, . . . , Y2pxe2x80x2 commonly connected thereto, the subgroups YY3xe2x80x2(1), YY3xe2x80x2(2), . . . , YY3xe2x80x2(k) each consists of Y2pxe2x80x2+1, Y2pxe2x80x2+2, Y2pxe2x80x2+3, . . . , Y3pxe2x80x2 commonly connected thereto, and similarly, the subgroups YYxe2x80x2ixe2x80x2(1), YYxe2x80x2ixe2x80x2(2), . . . , YYxe2x80x2ixe2x80x2(k) each consists of Y(ixe2x80x2xe2x88x921)pxe2x80x2+1, Y(ixe2x80x2xe2x88x921)pxe2x80x2+2, Y(ixe2x80x2xe2x88x921)pxe2x80x2+3, . . . , Yixe2x80x2pxe2x80x2 commonly connected thereto; and when the number of common electrodes respectively connected to the groups of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x21, XXxe2x80x22, . . . , XXxe2x80x2j of the k display units of mxe2x80x2xc3x97n matrix is qxe2x80x2, the first group of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x21 consists of electrodes X1, X1+jxe2x80x2, X1+2j, . . . , X1+(qxe2x80x2xe2x88x921)jxe2x80x2 commonly connected thereto, the second group of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x22 consists of electrodes X2, X2+jxe2x80x2, X2+2jxe2x80x2, . . . , X2+(qxe2x80x2xe2x88x921)jxe2x80x2 commonly connected thereto, the third group of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x23 consists of electrodes X3, X3+jxe2x80x2, X3+2jxe2x80x2, . . . , X3+(qxe2x80x2xe2x88x921)jxe2x80x2 commonly connected thereto, and similarly, ith group of the commonly connected Xxe2x80x2 electrodes, XXxe2x80x2jxe2x80x2 consists of electrodes Xjxe2x80x2, X2jxe2x80x2, X3jxe2x80x2, . . . , Xqxe2x80x2jxe2x80x2 commonly connected thereto, and thus the common electrodes are grouped so that the groups of the commonly connected Xxe2x80x2 electrodes in same order of each display unit may be simultaneously driven by the same driving signal.
Further, in the present invention, it is preferable that when p=k=2, and the sustaining electrodes of the first display unit and the sustaining electrodes of the second display unit are respectively identified and represented by Y1, Y2, Y3, . . . , Yixe2x80x2 and Yixe2x80x2+1, Yixe2x80x2+2, Yixe2x80x2+3, . . . , Y2ixe2x80x2, the first group of the commonly connected Y electrodes, YY1 consists of electrodes Y1 and Yixe2x80x2+1 commonly connected thereto, the second group of the commonly connected Y electrodes, YY2 consists of electrodes Y2 and Yixe2x80x2+2 commonly connected thereto, the third group of the commonly connected Y electrodes, YY3 consists of electrodes Y3 and Yixe2x80x2+3 commonly connected thereto, and similarly, the ith group of the commonly connected Y electrodes YYi consists of electrodes Yixe2x80x2 and Y2ixe2x80x2 commonly connected thereto; and while the number of groups of commonly connected X electrodes, j must be an even number, the first group of the commonly connected X electrodes, XX1 consists of electrodes X1, X5, X2mxe2x80x2xe2x88x924, and X2mxe2x80x2 commonly connected thereto, the second group of the commonly connected X electrodes, XX2 consists of electrodes X2, X6, X2mxe2x80x2xe2x88x925, and X2mxe2x80x2xe2x88x921 commonly connected thereto, the third group of the commonly connected X electrodes, XX3 consists of electrodes X3, X7, X2mxe2x80x2xe2x88x926, X2mxe2x80x2xe2x88x922 commonly connected thereto, and similarly, jth group of the commonly connected X electrodes, XXj consists of electrodes Xj, Xj+4r, X2mxe2x80x2xe2x88x92j+1xe2x88x924r, X2mxe2x80x2j+1 commonly connected thereto where r is a quotient obtained by dividing j by 4.
In addition, to achieve the above objective, there is provided a driving method of an mxc3x97n plasma display panel having m pairs of scan electrodes having m sustaining electrodes Y1, Y2, . . . , Ym and m common electrodes X1, X2, . . . , Xm which are arranged alternately and in parallel, and n data electrodes arranged to be orthogonal with respect to the m pairs of scan electrodes, where while the sustaining electrodes Y1, Y2, . . . , Ym are divided into i groups of electrodes and electrodes in each group are connected to a common line to form i groups of commonly connected Y electrodes, YY1, YY2, . . . , YYi, and the common electrodes X1, X2, . . . , Xm are divided into j groups of electrodes and electrodes in each group are connected to a common line to form j groups of commonly connected X electrodes, XX1, XX2, . . . , XXj, the scan electrodes are connected so that only one pair of an X electrode and an Y electrode among the i group of commonly connected Y electrodes, YY1, YY2, . . . , YYi and the j groups of commonly connected X electrodes, XX1, XX2, . . . , XXj may be arranged to neighbor with each other, wherein the driving method includes: an initialization step of completely erasing a wall charge created at subfield during a previous step; and an address discharge step of selecting and priming a pixel corresponding to image information, wherein the address discharge step includes the steps of: impressing sequentially to the groups of commonly connected X electrodes first pulses having an amplitude of a second voltage with reference to a first voltage of a reference voltage impressed to the scan electrodes, and a width smaller than that of the driving signal pulse of the data electrodes; and impressing sequentially to the groups of commonly connected Y electrodes second pulses having an amplitude of a third voltage having a polarity opposite to that of the second voltage with reference to a first voltage and a width of the period for which the first pulses are impressed once respectively to all the groups of commonly connected X electrodes.
In the present invention, it is preferable that while each pulse of the driving signal of the data electrodes is impressed later, with delay of a predetermined time, than each first pulse, the pulse of the driving signal of the data electrodes is impressed within at least 10 xcexc sec after the second pulses is divided by the same width of the first pulses and is impressed to the groups of commonly connected Y electrodes during the same period to correspond to each of the first pulses.
Further, in the present invention, it is preferable that in the address discharge step, a barrier voltage which has the same polarity of the first pulses and is lower than the second voltage is impressed between the first pulses impressed sequentially to each of the groups of commonly connected X electrodes, and it is also preferable that a sustaining discharge stabilizing pulse of a fourth voltage having a width narrower than that of sustaining discharge pulse is periodically impressed to the data electrodes during the sustaining discharge period.
In addition, to achieve the above objective, there is provided another driving method of an mxc3x97n matrix plasma display panel where an mxc3x97n matrix plasma display panel having m pairs of scan electrodes having m sustaining electrodes Y1, Y2, . . . , Ym and m common electrodes X1, X2, . . . , Xm arranged alternately and in parallel, and n data electrodes arranged to be orthogonal with respect to the m pairs of scan electrodes, is an 2mxe2x80x2xc3x97n matrix plasma display panel having 2 display units arranged each consist of mxe2x80x2 pairs of scan electrodes having mxe2x80x2 sustaining electrodes Y1, Y2, . . . , Ymxe2x80x2 and mxe2x80x2 common electrodes X1, X2, . . . , Xmxe2x80x2 arranged alternately and in parallel; when sustaining electrodes and common electrodes of a first display unit of the 2 display units are expressed by Y1, Y2, . . . , Ymxe2x80x2, and X1, X2, . . . , Xmxe2x80x2, respectively and sustaining electrodes and common electrodes of a second display unit are expressed by Ymxe2x80x2+1, Ymxe2x80x2+2, . . . , Y2mxe2x80x2, and Xmxe2x80x2+1, Xmxe2x80x2+2, . . . , X2mxe2x80x2, while the sustaining electrodes of the 2 display unit are connected to each other to form groups of commonly connected Y electrodes YY1, YY2, YY3, . . . , YYi, respectively, a first group of commonly connected Y electrodes, YY1 consists of Y1 and Ymxe2x80x2+1 commonly connected thereto, a second group of the commonly connected Y electrodes, YY2 consists of electrodes Y2 and Ymxe2x80x2+2 commonly connected thereto, a third group of the commonly connected Y electrodes, YY3 consists of electrodes Y3 and Ymxe2x80x2+3 commonly connected thereto, and similarly, the ith group of the commonly connected Y electrodes YYi consists of electrodes Ymxe2x80x2 and Y2mxe2x80x2 commonly connected thereto, and while the common electrodes of the 2 display unit are connected to each other to form groups of commonly connected X electrodes XX1, XX2, XX3, . . . , XXi, respectively, the number of the groups of commonly connected X electrodes, j, must an even number, a first group of the commonly connected X electrodes, XX1 consists of electrodes X1, X5, X2mxe2x80x2xe2x88x924, and X2mxe2x80x2 commonly connected thereto, a second group of the commonly connected X electrodes, XX2 consists of electrodes X2, X6, X2mxe2x80x2xe2x88x925, and X2mxe2x80x2xe2x88x921 commonly connected thereto, a third group of the commonly connected X electrodes, XX3 consists of electrodes X3, X7, X2mxe2x80x2xe2x88x926, X2mxe2x80x2xe2x88x922 commonly connected thereto, and similarly, jth group of the commonly connected X electrodes, XXj consists of electrodes Xj, Xj+4r, X2mxe2x80x2j+1xe2x88x924r, X2mxe2x80x2j+1 commonly connected thereto where r is a quotient obtained by dividing j by 4, wherein the driving method includes: an initialization step of completely erasing a wall charge created at subfield during a previous step; and an address discharge step of selecting and priming a pixel corresponding to image information, wherein the address discharge step includes the steps of: impressing alternately in sequential order and in reverse order of XX1, XXj, XX2, XX(jxe2x88x921), XX3, XX(jxe2x88x922), . . . to the groups of commonly connected X electrodes first pulses having an amplitude of a second voltage with reference to a first voltage of a reference voltage impressed to the scan electrodes, and a width smaller than that of the driving signal pulses of the data electrodes; and impressing sequentially to the groups of commonly connected Y electrodes second pulses having an amplitude of a third voltage having an polarity opposite to that of the second voltage with reference to a first voltage and a width of the period for which the first pulses are impressed once respectively to the 2 groups of commonly connected X electrodes.
In the present invention, it is preferable that wherein a sustaining discharge stabilizing pulse of a fourth voltage having a width narrower than that of sustaining discharge pulse is periodically impressed to the data electrodes during the sustaining discharge period.
In addition, to achieve the above objective, there is provided still another driving method of a plasma display panel having mxe2x80x3+2 scan electrodes and n data electrodes, where while among an mxc3x97n matrix plasma display panel having mxe2x80x3 +2 scan electrodes and n data electrodes, the 2 outmost electrodes at the one side among the mxe2x80x3+2 scan electrodes are provided as preliminary discharge electrodes, and while the mxe2x80x3 scan electrodes consist of pairs of mxe2x80x3 sustaining electrodes Y1, Y2, . . . , Ymxe2x80x3 and mxe2x80x3 common electrodes X1, X2, . . . , Xmxe2x80x3, the sustaining electrodes are divided into i groups of commonly connected Y electrodes (Y1, Y2, . . . , Yp), (Yp+1, Yp+2, . . . , Y2p), . . . , (Ymxe2x80x3xe2x88x92p+1, Ymxe2x80x3xe2x88x92p+2, . . . , Ymxe2x80x3), each group consisting of p neighboring electrodes commonly connected thereto, and the common electrodes are divided into j groups of commonly connected X electrodes, (X1, X1+j, X1+2j, . . . , Xmxe2x80x3j+1), (X2, X2+j, X2+2j, . . . , Xmxe2x80x2j+2), . . . , (Xj, X2j, X3j, . . . , Xmxe2x80x3), each group consisting of q electrodes commonly connected thereto which each are at (j+1)th position from j common electrodes at one side, wherein the driving method includes: an initialization step of completely erasing a wall charge created at subfield during a previous step; a step of impressing to the 2 preliminary discharge electrodes preliminary discharge pulses having a amplitude and a width same as those of the voltage of the initialization step utilizing the scan electrodes and a polarity opposite to that of it; and an address discharge step of selecting and priming a pixel corresponding to image information, wherein the address discharge step includes steps of: impressing sequentially to the groups of commonly connected X electrodes first pulses having an amplitude of a second voltage with reference to a first voltage of a reference voltage impressed to the scan electrodes, and a width smaller than that of the driving signal pulses of the data electrodes; and impressing sequentially to the groups of commonly connected Y electrodes second pulses having an amplitude of a third voltage having a polarity opposite to that of the second voltage with reference to a first voltage and a width of the period for which the first pulses are impressed once respectively to all the groups of commonly connected X electrodes.
In the present invention, it is preferable that each pulse of the driving signal of the data electrodes is impressed later, with delay of a predetermined time, than each first pulse, it is preferable that the second pulse which is divided by the same width of the first pulses and is impressed to the groups of commonly connected Y electrodes during the same period to correspond to each of the first pulses, it is preferable that total erase pulses impressed respectively to the groups of commonly connected X electrodes in the initialization step are impressed to them to be overlapped in the width of the preliminary discharge pulse for a certain period, it is preferable that in the address discharge step, a barrier voltage which has the same polarity of the first pulses and is lower than the second voltage is impressed between the first pulses impressed sequentially to each of the groups of commonly connected X electrodes, and it is preferable that a sustaining discharge stabilizing pulse of a fourth voltage having a width narrower than that of sustaining discharge pulse is periodically impressed to the data electrodes during the sustaining discharge period.

Plasma display panel and driving method thereof


Bookmark information indicative of a time corresponding to a given time series data piece for a predetermined time, state transition information indicative of a state of the time series data piece for the predetermined time, and the time series data piece are loaded in a database. The state transition information has one of a value indicative of an online state, a value indicative of a loading state, and a value indicative of a state in which data in the data area is empty. The time series data pieces for the predetermined times are loaded in a plurality of data areas of the database in sequence of times. In accordance with a data deletion request, state transition information corresponding to a data piece of information corresponding to a data piece of interest is set to a value indicating that the data piece of interest is empty.

The present invention relates to a time series database processing system, of an especially ultra-large scale, for storing data pieces serving as updating detailed information in a sequence of time series in a database and for controlling addition/deletion/retrieval of data.
When data pieces are loaded on a database of a large scale and a specified data piece is retrieved from the database, an index is generally applied. Indexing is effective when an item serving as a key during retrieval can be specified. The indexing is a contrivance in which specified key items of a database are collected, a pointer is provided over the key items to take the form of a balanced tree (B tree), and the tree can be traced at a high speed up to a location corresponding to a leaf of the tree in accordance with information indicating which range a key of a specified value lies in. "An Introduction to Database Systems, 3.4 Indexing" by C. J. Date, Addison-Wesley, 1986, pp. 68-77 teaches a contrivance in which information corresponding to storage locations of all data items can be obtained for all the data items. If the database is for about million cases or events, there occurs no problem. But in a database of an ultra-large scale for billion cases or trillion cases, however, the maintenance of index per se swells, and especially, keys which are added in time series fashion may not be handled well.
When data pieces are added in time series fashion, the indexing grows in a direction in which time increases, as shown in FIG. 1. Further, from the standpoint of deletion, it is known that as deletion of indices for which a constant time has expired proceeds, data pieces remain at only one side portion of the indexing tree and values of items are lost in spite of the existence of nodes on the other side portion, thereby placing the indexing in very inefficient condition. In such an event, it is necessary that the indexing be reconstructed by a technique called reorganization to delete wasteful areas in the indexing and promote the efficiency. But in the time series database of ultra-large scale, this is not practical because work far exceeding the permissible range is required.
A utility for data loading uses a technique for writing data directly to a physical area of a database and therefore, with this utility, data can be written at a high speed. However, the utility for high-speed data loading generally inhibits direct data writing to the physical area during data loading from a conflicting area at other retrieval or updating access. In other words, data loading shall compulsorily be executed while inhibiting access to a specified table for retrieval/updating or a part of a table for retrieval/updating. This forces retrieval of the database to be once stopped each time that time series data is loaded, which can be on a daily basis. In a database of ultra-large scale, it takes one day or more for retrieval per se in some applications. In that case, data loading cannot be permitted unless retrieval is stopped, leading to fatal inconvenience. To avoid such situations, data can be added through usual data insertion operation without resorting to data loading, but in this case the performance is degraded by approximately by one order as compared to data loading of a physical writing type. Besides, locking must be acquired for concealing data during addition, largely affecting the performance of operation for retrieval of all cases or events in the database.
In order to delete a data piece in the database for which a constant time has expired, the data piece is typically required to be retrieved, and even in the case of an index, the time consumed in comparison to that for inserting data piece by piece is significant. In the absence of index, all data pieces are retrieved for the purpose of deleting a data piece of interest and consequently, in the database of ultra-large scale, it takes one day or more to operate only the deletion processing and practically, the time series database cannot be materialized.
Thus, for the deletion of data for which a constant time has expired, time exceeding that for retrieval of all pieces of data is consumed in the absence of an index but conversely, in the presence of an index, indexing is updated during deletion, leading to an operation which consumes much time as in the case of data insertion. Accordingly, it is practically difficult to realize daily data deletion for the database which takes one day or more to retrieve all data pieces.

Data structure in database, database system for managing database and database managing method and system