A slag powder and cement production system capable of utilizing slag immediately after generation as a byproduct of a primary manufacturing process to recover thermal energy of slag concurrently with preparation of slag for cement in a powdered form to maximize energy recovery from primary manufacturing process and to minimize energy consumption to transform slag into a slag powder. Preferably the heat removed from the liquid slag as it solidifies is recovered for useful work, such as sustaining the primary manufacturing process or co-located cement production process and/or electric power production preferably through a supercritical CO2 thermodynamic cycle operating through a heat exchanger less transfer of thermal energy from the slag.

With the rise of energy and transportation costs as well as increased concerns about greenhouse gas emissions, it is desirable to reduce the energy usage and carbon dioxide production associated with the manufacture of steel and cement, two of the quintessential construction materials of industrialized society, with the former used extensively in applications ranging from transportation to furniture. Current production techniques create steel and slag in one process with slag considered a waste byproduct having no meaningful value. A second and separate process is then utilized to grind the subsequently cooled slag for use as a filler with cement for the creation of a lower cost concrete. Locating both processes in a highly integrated manner at one industrial site such that the by-product of one is fed directly into the other minimizes a range of operating costs including the transport costs to a concrete plant. However, these previously separate processes can be modified such that the heat generated from the primary manufacturing process as embedded in the hot slag—which is typically wasted—is utilized to produce electricity (or mechanical shaft power) for sustaining both processes and for transmission, reducing the monetary cost and environmental impact of producing the materials while generating electricity that might otherwise come from the burning of fossil fuels. Thus, three industries—steel, cement, and power—can be impacted. Steel and cement are revolutionized, while the power industry is enhanced through the reduction of overall energy consumption and maximizing exergy efficiency on a kilowatt-hour basis.
Slag is the partially vitreous by-product of the smelting of metal ores. Its composition varies based on the ore being smelted, but it typically contains metal oxides and silicon dioxide. The smelting of iron ore in a blast furnace, an important step in the production of pure iron and steel, produces slag containing calcium oxide (CaO), silicon dioxide (SiO2), aluminum oxide (Al2O3), magnesium oxide (MgO), iron oxides (FeO and Fe2O3), manganese oxide (MnO), and elemental sulfur (S); steel furnace slag, produced as a by-product of iron processing in a basic oxygen furnace or scrap steel processing in an electric arc furnace, contains all of the same compounds as well as phosphorous pentoxide (P2O5) and elemental iron (Fe). The cooling process affects slag structure and properties. Air-cooled slag is predominantly crystalline and has little or no cementitious properties, making it suitable primarily as a mineral aggregate. On the other hand, quickly quenching molten slag (such as with water) produces granulated slag, which is glassy and exhibits hydraulic properties (i.e., it hardens due to hydration). Thus, ground granulated blast furnace slag (GGBFS) is often referred to as "slag cement", though the term can also be applied to mixtures of Portland cement and ground slag. Expanded slag is similar to GGBFS and is produced by treating molten blast furnace slag with controlled amounts of water, as currently known in the art, in various pit and machine processes, resulting in a material with cementitious properties between those of air-cooled slag and GGBFS dependent on the amount of crystallization.
Historically, slag was discarded as an essential waste of iron and steel production, at least until the beginning of the 19th century, when it became commonly used for construction in Europe. Since then, slag cement blends have demonstrated greater consistency, greater strength gains after setting, greater resistance to seawater and other chemical agents, reduced expansion, higher compressive and flexural strengths, and lower permeability compared to ordinary Portland cement (OPC). Because they are made of a recycled material, slag cements also reduce energy consumption and greenhouse gas emissions.
Olivine and serpentine are magnesium-iron minerals with the ability to adsorb (i.e., weakly bind) carbon dioxide (CO2) when heated to within a certain temperature window as known in the art. The carbonation reaction is an equilibrium reaction, such that the amount and rate of carbon dioxide adsorbed by the mineral is a function of both temperature and pressure. At supercritical pressures for carbon dioxide, a peak adsorption level occurs at approximately 200 degrees Celsius to 300 degrees Celsius, as known in the art. The carbon dioxide adsorption is an exothermic reaction. This unique property allows both minerals (olivine and/or serpentine, with the minerals in slag) to be utilized for carbon sequestration and/or carbon dioxide emissions avoidance respectively to combat global warming. By incorporating either or both of these minerals into a slag cement blend and heating the mixture during processing, the cement itself functions as a carbon dioxide reservoir, making the cement eco-friendly not only by recycling waste from steel production, but by allowing the removal and permanent storage (at least on a geological time line, as compared to "pumping" it into the ground) of additional carbon dioxide from the atmosphere.
WO 2006/123921 and US Patent No. US 2008/0168928 both titled "Concrete Composition Containing Atomized Steelmaking Slag And Concrete Blocks Using The Concrete Composition" by Oh et. al., discloses the production of atomized steel making slag balls to replace fine aggregates, preferably with a quantity greater than 30% replacement of known in the art fine aggregates. Furthermore, '921 utilizes slag balls created using "high-pressure gas mixed with water spray(ed)". The utilization of water (understood to become water vapour) in the quenching process is fundamentally different than the disclosed invention which is preferably void of water vapour.
Furthermore, and importantly, the resulting atomized steel slag balls are also differentiated from the disclosed invention as the slag balls are a non-reactant filler for fine aggregates. '921 also does not enable carbonated materials to be incorporated at high levels in the resulting cement or concrete.
WO 2007/145384 titled "A Method For Stabilizing Slag And Novel Materials Produced Thereby" by Oh et. al., discloses a converter (of slag) refining process that utilizes high-speed oxygen to remove carbon saturated in molten iron via an oxidation reaction. Typically lime is utilized to supplement the inherent CaO. In the conventional treatment, a large amount of water is sprayed. The resulting free CaO (a.k.a. free lime) tends to produce calcium hydroxide (Ca(OH)2) when it contacts the sprayed water, is not desired for traditional Portland cement. '384 provides a method to minimize the generation of free lime that reduces/eliminates instability of converter slag that is caused upon cooling. One provision is a method for stabilizing slag that comprises and is dependent on molten slag to fall; subsequent injection of high-pressure gas to the falling molten slag to separate the molten slag into fine droplets; and finally quenching the fine droplets with the injected gas and surrounding atmosphere. '384 not only prefers the rate of mass flow rate of the slag (Jslag) to massflow rate of the injected gas (Jslag) to be in the range of 0.4 to 1.7 but specifically does everything possible to ensure the mass flow ratios to not exceed 1.7. One method of '384 to limit the ratio is by preferably utilizing water mist to the slag behind the area of gas injection. '384 also utilizes carbon particles having a sphere-equivalent diameter in the range of 30 to 150 micron injected into the falling molten slag, along with the injected gas (assumed to be containing oxygen, as carbon requires the presence of oxygen in order to oxidize into carbon monoxide or carbon dioxide). '384 discloses "on the other hand, if a greatly smaller amount of slag than the amount of injected gas is discharged, a treatment time is extended and consumption of gas increases excessively, resulting in inefficient and uneconomical treatment. Accordingly, it is essential to set an appropriate rate of discharge amount of slag/amount of injected gas." Again, '384 does everything possible to avoid a mass flow ratio between slag and injected gas greater than 1.7, with specific concern of excessive consumption of gas. This is attributed to their energy consuming injected gas, as compared to the present disclosed invention that is net power producing.
'384 further limits the temperature to less than 1550 Celsius due to a "very fast linear velocity at an outlet of the nozzle, thus making it difficult to maintain desired quenching conditions suitable to restrict phase transformation". '384 does anticipate the inclusion of additive for subsequent exothermic oxidation reactions to increase the slag temperature prior to atomizing. '384 does anticipate an increase in surface area, but is limited to the surface of the resulting slag balls and by explicitly blowing carbon powder along with the gas. This method is suitable only in the presence of oxygen, as an injection gas void of oxygen would simply lead to the carbon powder remaining on the surface of the atomized slag ball thus actually reducing the effective slag exposed surface area and not adding any surface porosity. '384 does further anticipate the utilization of a high mass flow rate of the injected gas, beyond their invention, to increase the surface area by first the creation of smaller particle size (100 micron or less) with subsequent agglomeration to a size of 1 to 10 mm. '384 is net energy consuming, as significant energy is required to produce high-pressure injection gas. '384 requires the molten slag to fall, as the discharged gas from the high-pressure injection gas is not utilized for any other purpose, thus the only objective is for the resulting atomized stabilized slag to fall via gravity. '384 further selects the injection gas from air, nitrogen, argon and helium, all of which have approximately less than 1% carbon dioxide. '384 further views the optimal size of the stabilized slag above the range of 200 micron to 5 mm, as the resulting stabilized slag is simply a replacement for fine aggregates and not a chemical reactant. '384 expansion of injected gas is effectively non-contained, and the slag is falling. '384 has low heat transfer rate, as the gas approximately immediately expands to atmospheric pressure. The injection gas at atmospheric pressure has a relatively low density and a comparably low coefficient of heat transfer. '384 specifically avoids the formation of free lime, and the absence of CO2 limits the formation of carbonates. Furthermore, the formation of carbonates is an approximately slow process due at least in part due to the low pressure of discharge gas (i.e., expanded injection gas) and low concentration of CO2.
U.S. Pat. No. 6,803,016 titled "Device For Atomizing And Granulating Liquid Slags" by Edlinger discloses a jacketed atomizing method that advantageously may be operated in a manner that the propellant jet is fed under supercritical conditions so as to cause its rapid expansion after having left the nozzle, by which the propellant jet is accelerated to supersonic speed. '016 utilizes a jet of combustion off-gases and (water) vapor as the propellant jet while, furthermore, gaseous hydrocarbons are also advantageously used as said coolant. When using these media, it is ensured at a comparatively low pressure that supercritical conditions and hence under-expanded media are fed to the respective nozzle, whereupon a rapid and vigorous expansion will subsequently occur so as to attain the desired supersonic speeds. The condensation of water from a propellant jet comprised of combustion off-gases and water vapor at a substoichiometric combustion results directly in a reducing gas CO+H2, a balance of CO2 that may be reused as a burning gas, to prevent the reoxidation of the iron powder.
In '016 both of the jets are able to impinge at supersonic speed creating a rapid and intensive comminution that is reached with a cloud forming subsequently, in which rapid cooling under a simultaneous rapid volume increase takes place due to the chemical decomposition of the cooling gas. The hydrocarbons of the coolant emerging in the sense of arrow are thereby reacted to CO and H2, said reaction with vapor leading to a doubling of the volume; since both media can be fed supercritically and, therefore, expand rapidly upon emergence from the nozzles, in particular the Laval nozzles, intensive comminution work and, at the same time, rapid cooling of the liquid slag, which leaves the slag outlet opening as a tubular jacket, are ensured. The coolant comprises gaseous hydrocarbons; the propellant jet is fed to the nozzle mouth of the lance under supercritical pressure, and the coolant is fed to the coolant nozzles under supercritical pressure. '016 is fundamentally different from the present disclosed invention through the utilization of water (vapour), does not increase the surface area or porosity of the resulting slag powder, and is not a net energy producer but rather is a net energy consumer for the creation of the supercritical cooling gas.
U.S. Pat. No. 6,082,640 titled "Method For Granulating And Grinding Molten Material and Device For Carrying Out Said Method" by Edlinger discloses a process for granulating and comminuting molten material in which the slag melt is acted upon by compressed water and discharged together with the vapour formed.
The published paper titled "The Basic Study on the Preparation of Steel Slag Cement with Gas Quenching Steel Slag" by Yue Long et. al., strives to utilize traditional gas quenching as a method to reduce free lime (CaO) through size reduction and reduction of crystallization time through relatively rapid quenching. Long et. al., is otherwise traditional cement composition without promoting subsequent chemical reaction in the resulting concrete composition.
Another published paper titled "High volume limestone alkali-activated cement developed by design of experiment" by Alexander J. Moseson et. al., discloses a cement comprising ground granulated blast furnace slag, soda ash (sodium carbonate), and up to 68 wt. % granular limestone. Another approach to ecological cement is that of geopolymer or alkali-activated cement (AAC), which generally use no OPC. Their advantages over OPC may include: (i) drastically less CO2 production; (ii) longer life and better durability; (iii) better defense against chemical attack (e.g. chlorides, sulfates); (iv) rapid strength gain; (v) better performance in marine environments. Moseson et. al., utilized As noted above, four raw materials were used. The first was slag (GGBFS) (St. Lawrence Cement, Camden, N.J.) with a Blaine fineness of 498 m2/kg (as tested by the authors per ASTM C204-07 [29]). Xray Fluorescence (XRF) analysis of the GGBFS was carried out by Arkema, Inc. in King of Prussia, Pa. (Table 1). Second is sodium carbonate, Na2CO3 (Brenntag Pacific, Inc., Santa Fe Springs, Calif.). Third is granular limestone with a CaCO3 content of 89.3 wt. % and a MgCO3 content of 10.7 wt. % (Oldcastle Stone Products, Atlanta, Ga.). The cumulative particle size distribution of the latter is: 23%<75 lm, 48%<150 lm, 68%<300 lm, 100%<1000 lm. Fourth, tap water. Moseson et. al., utilizes standard slag powder as produced by the energy intensive process of grinding GGBFS. This is differentiated by the present invention disclosure as the GGBFS preparation process is energy intensive (consuming power), has traditional reactivity due to moderately low (less than 500 m2/kg) surface area thus requires a higher utilization of slag for an equivalent cement/concrete strength.
In another prior art solution, for the purposes of stabilizing converter slag and reducing the amount of CO2 down to a level satisfying environmental restrictions, slag stabilizing techniques have developed for transforming CaO in converter slag into CaC03 via carbonation using CO2 gas that is blown to the converter slag, as disclosed in: 7th Conference of the European Ceramic Society of 2001, p. 879 (T. Takahashi and M. Fukuhara) [Key Engineering Materials, vols. 206-213 (2002) p. 879; Adv. Cern. Res., 12 (2000) p. 97 (T. Isoo, T. Takahashi, N. Okamoto and M. Fukuhara; Am. Ceram. Soc. Bull., 80 (2001) p. 73 (T. Isoo, T. Takahashi and M. Fukuhara); and Materia Japan, 39 (2000) 7 p. 594 (M. Fukuhara and T. Takahashi). Stabilized slag resulting from the above techniques has been proved to be eco-friendly. However, actually, the conventional techniques have a complex necessity for various troublesome facilities and technical processes such as crushing, compression, molding, etc., which are required for the fabrication of large-sized slag blocks. Accordingly, it can be said that the conventional techniques are impractical and uneconomical.
From AT 406 262 B a method for spraying oxidic slags became known, in which liquid slag was ejected from a tundish via a tundish tube, wherein a lance was introduced into the liquid slag to inject a propellant gas and, in particular, water vapor. The tundish tube provided in the slag outlet of the tundish as illustrated in AT 506 262 B could also be designed in the manner of a Laval nozzle, whereby vapor flow velocities in the supersonic range were observed, too, both due to the supercritical conditions under which hot vapor or water vapor was supplied and due to the subsequent possibility of a rapid expansion. In that known device a slag melt having temperatures of between about 1300° and 1500° C. was, thus, ejected using hot vapor as a propellant, rapid cooling having been effected subsequently within the cooling chamber by the reaction of carbon or carbon carriers with water vapor and the slag heat to carbon monoxide and H2, thus providing reducing conditions.
Thus, a need exists for a system capable of producing steel, slag cement, and electric power simultaneously while reducing the greenhouse gas emissions and overall environmental impact of all associated processes.


A cabinet capable of guiding light, which is used for detecting a biological sample strained with a fluorescent dye, includes a main body, at least one light source, and at least one light guiding structure. The main body has a sample table to place the biological sample. The at least one light source is provided on the main body and near the sample table, wherein the at least one light source provides light required to excite the fluorescent dye incorporated in the biological sample. The at least one light guiding structure is provided between the sample table and the at least one light source to refract the light provided by the at least one light source onto the sample table and the biological sample. Whereby, the biological sample is exposed to more light, and therefore the intensity of the light released from the biological sample is enhanced.

1. Technical Field
The present invention relates generally to bio-detection device, and more particularly to a cabinet which is capable of guiding light.
2. Description of Related Art
In the current field of biotechnology, fluorescence detection is a relative simple and most widely used method for detecting specific molecules in biological samples. In this method, particular fluorescent dyes such as Ethidium Bromide, SYPRO RUBY, and SYBR Green I are incorporated into biological samples. These fluorescent dyes can be excited by light of certain wavelengths to release visible light due to the effect of fluorescence resonance energy transfer (FRET). Therefore, researchers are able to perform certain naked eye observations in this way.
Ethidium Bromide is commonly used in early fluorescence detection, and this kind of fluorescent dyes has to be excited by ultraviolet rays in a dark room. Such experimental environment is harmful to researchers in the long term. Recent fluorescence detection typically takes SYPRO RUBY and SYBR Green I as fluorescent dyes, which can be excited by blue light in a normal laboratory. Researchers usually use blue light emitting diodes (LEDs) to provide the required blue light, and biological samples are placed on a dark background to make higher contrast for clearer observation.
However, the light released by fluorescent dyes is quite weak relative to the ambient light in a laboratory. One of the methods of increasing the intensity of the released light is to deploy more LEDs. In fact, such method only increases the area exposed under light, and is not really that helpful at enhancing the light intensity accepted by biological samples. Besides, a cabinet with more LEDs is clearly larger and heavier, and has higher cost.


A king pin is mounted in a hollow axle. An insert is force fit into each end of the hollow axle. The insert includes an aperture that aligns with an aperture in a wall of the hollow axle to provide a mount structure for the king pin. This mount structure thus provides a solid and reliable mount in a very simplified manner. The hollow axle and insert are also provided with draw key holes such that bolts may lock the king pin within the insert and the hollow axle.

This application relates to the use of a solid insert plug at an end of a hollow axle to provide a mount location for a king pin.
Hollow axles are known, and are utilized in vehicles to provide various benefits. The hollow axle provides a lightweight alternative to solid axles.
One challenge with a hollow axle is the provision of components at the end of the axle that are to be mounted to the axle. As an example, king pins are typically mounted at the end of axles for heavy vehicles, and provide a pivot axis for steering associated wheels.
One family of methods of forming hollow axles to have structure at their ends is disclosed in co-pending U.S. application Ser. No. 10/056,945. This application, invented by the inventor of the present application, discloses a family of methods of forming axles, and for attaching structure at the end of the axles. Among the structures that may be attached are various king pin mount structures.
Some of these methods may be cumbersome, and somewhat difficult to achieve in production. Thus, a simpler manner of providing a mount location for a king pin would be desirable.

Method of mounting a king pin at an end of a hollow axle


A practice device to enable children to simulate skateboarding in a safe manner so the children can practice sliding the practice device on a surface and balancing themselves on the device. The device comprises a center section, a front section and a rear section where the front and rear sections are at an angle to the center section and the bottom surface of the device is entirely smooth to facilitate the movement of the device on a surface. The upper surface of the device has a lowered interior area surrounded by a circumferential ridge.

1. Field of the Invention
The present invention relates to the field of sporting goods and in particular, to skateboards. The present invention also relates to the field of practice devices which enable a child to learn how to use a skateboard.
2. Description of the Prior Art
In general, skateboards and other similar sporting goods such as skis are known in the prior art. The following 14 patents and published patent applications are the closest prior art of which the inventor is aware:
1. U.S. Pat. No. 3,655,211 issued to Bollettieri on Apr. 11, 1972 for "Double Bend Stave" (hereafter the "Bollettieri Patent");
2. U.S. Pat. No. 3,862,768 issued to England on Jan. 28, 1975 for "Rollable Fulcrum Balancing Board Recreational And Exercise Device Provided With non-Linear Stabilization Features" (hereafter the "England Patent");
3. U.S. Pat. No. 4,270,764 issued to Yamada on Jun. 2, 1981 for "Noisemaker For Skateboard" (hereafter the "Yamada Patent");
4. U.S. Pat. No. 5,044,250 issued to Beyer on Sep. 3, 1991 for "Drumstick With Sounding Pellets" (hereafter the "Beyer Patent");
5. U.S. Pat. No. 5,267,743 issued to Smisek on Dec. 7, 1993 for "Low Profile Skateboard" (hereafter the "Smisek Patent");
6. U.S. Pat. No. 5,460,558 issued to Woodstock on Oct. 24, 1995 for "Surfboard Foot Saddle" (hereafter the "Woodstock Patent");
7. United States Patent No. Des. 379,647 issued to Levinthal on Jun. 3, 1997 for "Pair Of Ski" (hereafter the "Levinthal Patent");
8. United States Patent No. Des. 417,250 issued to Colin on Nov. 30, 1999 for "Gliding Board" (hereafter the "Colin Patent");
9. U.S. Pat. No. 6,059,307 issued to Western on May 9, 2000 for "Skateboard Deck And Method For Making The Same" (hereafter the "Western Patent");
10. U.S. Pat. No. 6,290,249 B1 issued to Wolf on Sep. 18, 2001 for "Snow-Gliding Apparatus" (hereafter the "Wolf Patent");
11. United States Patent No. US D457,587 S issued to Wolf on May 21, 2002 for "Snow-Gliding Apparatus" (hereafter the "Wolf Patent");
12. United States Patent Application Publication No. US 2002/0121752 A1 by inventor Gille published on Sep. 5, 2002 for "Snowskate And Snow Scooter" (hereafter the "Gille Patent");
13. United States Patent Publication No. US 2003/017832 A1 by inventor Sachs published on Jan. 23, 2003 for "Recreational Balancing Apparatus" (hereafter the "Sachs Patent");
14. U.S. Pat. No. 6,543,769 B1 issued to Podoloff on Apr. 8, 2003 for "Snowboard Apparatus" (hereafter the "Podoloff Patent");
The Bollettieri Patent discloses staves which are used as skis on snow and water. The staves have substantially equal bends at their front and rear ends The device has several longitudinally extending grooves 17 which serve the purpose of skis.
The England Patent discloses a rollable fulcrum and essentially is a device which is in the shape of a Mexican sombrero hat having a ball in the center on which the individual balances. This patent shows an exercise type device.
The Yamada Patent discloses a noisemaker for use in conjunction with a skateboard but the noisemaking device does not consist of internal pebbles or sand within the structure of the device which makes noise as the device is moved across a carpet. This device basically creates noise through mechanical structures as illustrated.
The Beyer Patent is a drumstick with sound pellets.
The Smisek Patent is a low profile skateboard and the essential feature is having a recess to receive the wheels of the skateboard so that the skateboard rests much lower to the ground than conventional prior art skateboards. However, referring to FIG. 4 it can be seen that the skateboard has front and back ends that are put at an angle to the horizontal portion of the board and the angle, however, is substantially less than 45 degrees.
The Woodstock Patent discloses a surfboard having a foot saddle to prevent the surfer from sliding off the back end of the board. Specifically referring to Column 2, line 30, the patent states "The foot saddle 10 consists of a structure 22 for maintaining one foot 24 of a surfer 26 in a stationary position upon the deck near the tail end of the surfboard and help prevent the surfer's foot 24 from inadvertently sliding off the surfboard."
The Levinthal Patent discloses a design for a ski. The design which can best be seen in FIG. 5 in cross section shows having arcuately shaped extending upward front and rear ends and a generally upwardly extending arcuate shaped center section.
The Colin Patent is also a design patent for the shape of a gliding board.
The Western Patent discloses the concept of a skateboard deck and method for making the same. The patent does show the concept of having a horizontal center section and then having upwardly extending front and rear ends although the angle is only 18 degrees at one end and 15 degrees at the other end.
The Wolf Patent discloses a snow gliding apparatus which includes an elongated member having an intermediate portion positioned between a pair of upturned end portions. The end portions are rounded and do not have a sharp 45 degree angle. Further, there are a multiplicity of lower grooves 26 and 36.
The published Gille Patent Application discloses a snowskate and snow scooter.
The published Sachs Patent Application discloses a device which is a recreational balancing apparatus which comprises a frame defining a horizontal opening therein, and a balancing board mounted on a joint assembly.
The Podoloff Patent discloses a snowboard apparatus which is a simulator for snowboarding and skateboarding.
None of the prior art patents teach a simple effective device for enabling children to learn how to use a skateboard in a safe and secure manner. There is a significant need for such an invention.

Practice device to enable children to simulate skateboarding


Firmware updates for, e.g., thin client devices may be achieved in a seamless, non-disruptive manner using a two-stage firmware loader, including a base loader pre-installed on the device and a caching loader downloaded, by the base loader, from a firmware server and thereafter responsible for downloading and updating other firmware application packages.

Traditional personal computers (PCs) are being replaced with simpler devices in "mission-critical" environments such as healthcare. So-called terminal devices provide only basic presentation (display), networking, and device-redirection services (to support, for example, keyboard, mouse, audio, and USB devices) for server-based computing—i.e., architectures in which a sophisticated remote server supplies applications or even entire desktops to the terminal device. The user interacts with the server-provided functionality via "receiver" or "terminal-emulation" software (or firmware) running on the terminal device, ideally rendering the experience indistinguishable from using local applications running on a conventional PC. The trend favoring these "thin" or "zero" client devices is driven by the desire to eliminate data at the edge of a computer network where it is vulnerable to compromise; to centralize the management of computing resources on highly available hardware; and to simplify management and support of the endpoint devices.
Thin clients may utilize system-on-chip (SOC) designs, which allow hardware device vendors to incorporate all the necessary computing, display, networking, audio, video, and USB device capabilities into one low-cost integrated circuit capable of running directly from "firmware"—i.e., basic system-level programming—stored on non-volatile (e.g., flash) memory. Firmware delivered by the hardware vendor typically comprises the base operating system (such as LINUX, UNIX, RTOS, etc.) combined with specialized programming that facilitates interfacing with device components for display management, 2D/3D graphics, imaging, and audio-visual coder/decoders (codecs), and supports external devices attached by the user (e.g., via USB ports). Terminal-emulation programs furnished with the thin client support a rich user experience through remote interaction with applications actually executing on the back-end servers; these programs use networks protocols such as RDP (Remote Desktop Protocol), ICA (Independent Computing Architecture) or PCoIP (PC over IP).
Ideally, firmware delivered on a thin client device remains up-to-date for the life of the hardware with no need to "re-flash" (i.e., remotely replace the firmware via a computer network). This frees local information-technology (IT) support personnel from managing installed firmware. In reality, however, firmware is periodically updated to fix bugs or to support new features or devices. Moreover, for certain types of firmware applications, the ability to modify the firmware is desirable for the purposes of ensuring proper functioning and/or customizing the applications. This is especially relevant for user-authentication-service (UAS) firmware that runs on the SOC to validate a user's identity prior to launching the terminal-emulation program with the correct user credentials. Because the UAS firmware generates the user interface (UI), both intermediate resellers and end-user customers often seek to customize the UAS in order to promote their own corporate branding, e.g., to display a hospital's mission or corporate logo when the device is in its ready state waiting for a user to log on. This requires the firmware to be field-modified for each customer—an impossibility for device-provided firmware. In addition, since the UAS is the authentication point for the entire system (all the way to the server hosting the desktop and end-user applications), the integrity of the firmware should be verifiable at any time to ensure that it has not been compromised.
The hardware vendor that supplies the client device typically facilitates updating the firmware via a management console that broadcasts new firmware versions to customers (in accordance with the maintenance policy in effect) and manages their installation remotely. This procedure performs a complete update of the firmware while optionally preserving settings or personalization already applied. But it leaves the hardware vendor in charge of when these updates occur. Moreover, a full upgrade to the system firmware can impose a considerable amount of down time since the device is inoperable during the upgrade—and particularly in fast-paced environments such as healthcare facilities, such delays may not be tolerable.

Secure, non-disruptive firmware updating


A computer-implemented method for detecting automated spam programs designed to transmit unauthorized electronic mail via endpoint machines may comprise: 1) monitoring electronic-mail traffic on an endpoint machine, 2) identifying a computer program on the endpoint machine that is responsible for at least a portion of the electronic-mail traffic on the endpoint machine, 3) accessing at least one rule for determining, based on characteristics of the program, whether the program comprises a spam program, and then 4) determining, by applying the rule to the program, whether the program comprises a spam program. Corresponding systems and computer-readable media are also disclosed.

The number of unsolicited bulk emails (also known as "spam") transmitted via the Internet has grown consistently over the past decade, with some researchers estimating that more than 80% of email is spam. Spam emails annoy consumers, consume precious network bandwidth and resources, and, in some cases, may be used as a vehicle for committing fraud.
In analyzing the widespread problem of spurn, researchers have estimated that a majority of spam emails originate from spambots on unsuspecting consumer computer systems. A spambot is a malicious program that is delivered to vulnerable computers via exploits. Upon launching, the spambot waits for commands from a malicious programmer's command and control center. Upon receiving a command, the spambot uses the unsuspecting consumer's computer to generate and transmit spam emails as directed by the command and control center.
Researchers have estimated that there are over 10 million spambots in existence today. By using unsuspecting consumer's computers, malicious programmers are able to generate tremendous amounts of spam with minimal risk of detection. As such, the instant disclosure identifies a need for identifying and eliminating spam bets from unsuspecting consumer's computer systems.

Systems and methods for detecting automated spam programs designed to transmit unauthorized electronic mail via endpoint machines


A CMD (change moduation device) control circuit in an optical card reproducing apparatus comprises a data interval detector which detects a data pit interval from a binary valued signal from a binary value converter and from a row and a column addresses generated by a row address generator and a column address generator, respectively, during scanning of a CMD sensor with a row address generator and a column address generator, a track guide column address detector for detecting a column address of a track guide from the binary valued signal by scanning the CMD sensor, and a decoder for decoding a recorded data from the data pit intervals detected by the data interval detector. In this optical card reproducing apparatus, the decoding is carried out directly from the recorded data pit intervals without moving the optical card during the reproducing operation. Thus, accurate decoding or reproducing of the data can be achieved.

1. Field of the Invention
The present invention relates to an optical card reproducing apparatus for reproducing information recorded on an optical card with light, more specifically, to an optical card reproducing apparatus having a two-dimensional solid-state image sensing means comprising plural photoelectric conversion elements which are distributed two-dimensionally on a plane wherein any photoelectric conversion element can be specified by a first address in the X-direction and a second address in the Y-direction.
2. Statement of Related Art
In general, in a conventional way to read a sequence of pits recorded on an optical card, the card is moved in the direction of a track so as to scan a sequence of the pits one-dimensionally with a spot light, such as a laser beam, and the sequential data signals obtained by a detector are decoded.
As described in Japanese Patent Application Laid-Open No. 2-223064, in reproduction of data recorded by the self-clock modulation method, data is reproduced by reading each distance between data pits. A light beam emitted from a semiconductor laser is converged onto an optical card through an optical system, so that an optical spot is produced. The light beam is reflected by the surface of the optical card and detected by a photodiode.
The existence of pits can be detected by judging the amount of the reflected light, thus a pit detection signal is retrieved. In reproduction of signals recorded by the self-clock modulation method, the synchronizing signal is produced as a clock signal using a PLL or the like by extracting it from the pit detection signals. A decoded data is produced from the pit detection signals at the timing of the synchronizing signals. The pit detection signal is extracted sequentially from a recording medium moving in the direction of a track. Therefore, the detection rate of the pit detection signal depends on a driving speed of an electric motor for driving an optical card. Reading and writing of data are usually started when a specific pattern, so-called sync pattern, is detected from demodulation data.
Japanese Patent Application Laid-Open No. 2-141932 by the present applicant discloses an optical card reproducing apparatus wherein a plurality of tracks are read at the same time by applying one or more light beams to the plurality of tracks. In this optical card reproducing apparatus, data on each track is read by a detecting device or the like. One detecting device is assigned to each track and each detector works independently. Even in this optical card reproducing apparatus, as in that described above in Japanese Patent Application Laid-Open No. 2-223064, signals are detected in sequence and the detection rate also depends on a driving speed of an electric motor.
As described above, in a system wherein pits recorded on an optical card are scanned with a light beam by driving a card and detection signals are read sequentially, the driving of a card by an electric motor leads to a fluctuation in the moving speed of the card, and further leads to a fluctuation in the interval time between each pit detection signal. Therefore, even if pits were recorded at an accurate interval at the time of recording, fluctuations in the interval of pit signals would occur during reading signals due to fluctuations in driving speed. When such a fluctuation is too large or when a certain sudden signal fluctuation is added to the fluctuation in driving speed, an appropriate clock signal cannot be generated resulting in an inability to read data. Furthermore, failure in detection of a sync pattern results in an inability to determine when to start reading/writing data, thus it becomes unable to read/write data. That is, when there exists some dust or a defect on a track to be accessed, or when large fluctuations in signals exist due to fluctuations in speed because of back-and-forth movement of a card, a clock signal cannot be appropriately generated or a sync pattern cannot be detected. Thus there is a problem that it is impossible to read data.
In the case of a write-once medium such as an optical card, a decision is required whether the area to be recorded is a blank area or a used area before writing is carried out so as to assure that the data is going to be written in an area which is really blank. When an area turns out to be already previously written generally, the area will be skipped. Therefore, it is required to make an accurate decision of a blank (no-date is recorded) track.
If data was re-written by mistake in a recorded area (that is, duplication occurs in writing) in a writing process, it would become impossible not only to read the data recorded later but also the previously recorded data. Moreover, in a reading process, it is wasteful to decode duplicated signals unless duplication is judged.
As described above, in conventional technologies, pits recorded on an optical card are scanned with a light beam to read the pit signals sequentially. During this process for reading the signals sequentially, there is some probability that some disturbance causes wrong decision that a recorded track is taken as a blank track (no-data track), or that a duplicated track is taken as a normal track to make useless and inaccurate decoding.

Optical card reproducing apparatus for reproducing information with a two-dimensional solid-state imaging device


An acknowledged MBMS service in which a procedure for providing retransmissions of incorrectly received data blocks is performed, together with an outer coding of the data blocks to be transmitted to the MBMS MSs. A sequence of data blocks carrying information related to the MBMS service is encoded at a BSS (Base Station Sub-system) of the mobile network by an outer coding unit. After the outer coding, the resulting data block sequence is sent to the MBMS MSs. If a data block of the outer coded sequence is badly received by a number of MBMS MSs, corresponding negative acknowledgements (nacks) are sent by such MSs to the BSS. The MSs also notify the BSS, with a positive acknowledgement, if they succeed in outer code decoding the sequence of the MBMS carrying information data blocks, in spite of possible badly received data blocks. The BSS manages retransmissions of the nacked data blocks taking into account the positive acknowledgements related to the outer code decoding by disabling retransmission of nacked data blocks of a positively acknowledged sequence.

Mobile telephony networks were initially conceived for enabling voice communications, similarly to the wired, Public Switched Telephone Networks (PSTNs), but between mobile users. Mobile telephony networks have experienced an enormous spread, especially after the introduction of second-generation mobile cellular networks, and particularly digital mobile cellular networks such as those complying with the Global System for Mobile communications (GSM) standard (and its United States and Japanese corresponding systems).
The services offered by these cellular networks in addition to plain voice communications have rapidly increased in number and quality; just to cite a few examples, Short Messaging System (SMS) and Multimedia Messaging System (MMS) services, and Internet connectivity services have been made available in the last few years.
Similarly to the PSTNs, second-generation cellular networks are switched-circuit networks; this greatly limits the bandwidth that can be allocated for a given user, especially in second-generation mobile networks. On the contrary, data communications networks such as computer networks and, among them, the Internet, adopt packet switching schemes, which allow much higher data transfer rates.
Some solutions have been proposed to overcome the limitations of conventional, switched-circuit cellular networks such as the GSM networks, so as to enable users of mobile terminals efficiently exploiting services offered through the Internet. One of the solutions that is acquiring a significant popularity is the General Packet Radio Service (shortly, GPRS). The GPRS is a digital mobile phone technology compatible with GSM networks (actually, built on the existing GSM network architecture) that enables data transfer at a speed higher than that allowed by pure GSM. Essentially, the GPRS can be viewed as a GSM add-up that supports and enables packet-based data communication. Although third-generation wireless communications systems such as those complying with the Universal Mobile Telecommunication System (UMTS) are more promising in terms of data transfer rates, the GPRS is a ready-at-hand solution for enhancing the data exchange capabilities of already existing GSM networks.
In GPRS communications networks the information content is usually transferred in a point-to-point (p-t-p) modality (or unicast modality), upon activation of a session between a GPRS mobile phone (or mobile station) and a service provider connected to a packet data network, e.g. a server connected to the Internet; the activation of such a session involves the setting up of logic connections between the server and the GPRS mobile phone. In such a p-t-p communication mode, the radio resources to be allocated for the exchange of data between the ground GPRS network and the GPRS mobile stations depend on the number of different mobile stations simultaneously exploiting the GPRS services, even if the same GPRS service is being exploited by two or more mobile station users at the same time. Clearly, this limits the possibility of simultaneously accessing available GPRS services by several users, unless the radio resources are oversized.
Thus, it is desirable to have the possibility of delivering information contents related to a same GPRS service exploitable by two or more users at a time through a point-to-multipoint (p-t-M) modality, so as to save the amount of allocated resources.
In this respect, the 3GPP (3rd Generation Partnership Project) is discussing the implementation, in the GERAN (GSM/EDGE Radio Access Network) framework, of a new kind of service, named MBMS (Multimedia Broadcast/Multicast Service).
Basically, MBMS targets simultaneous distribution of information content (e.g. multimedia content) to more than one user from a single serving base station over a common radio resource.
A general problem related to a service exploiting a p-t-M modality, such as MBMS, is to provide a satisfying and reliable service at least for most users.
In this respect, a first approach followed by 3GPP was not to guarantee reception of MBMS at RAN (Radio Access Network) level: see 3GPP Technical Report TR 25.992 V6.0.0 (2003-09). According to this Technical Report, MBMS should not support individual retransmissions at the radio link layer, nor should it support retransmissions based on feedback from individual subscribers at the radio level.
In more recent submissions made at GERAN Meetings #18 and #19, some proposals have been made in order to provide the network with suitable procedures adapted to lowering the loss rate of the p-t-M transmission, or at least to derive information on the quality of service perceived by the users.
Document Tdoc G2-040286 ("Common Feedback Channel for MBMS delivery"), submitted by Siemens at the GERAN WG2 #18 bis Meeting, held in Phoenix, Ariz., U.S.A. from Mar. 22 to Mar. 26, 2004, discloses definition of a Common Feedback CHannel (CFCH) intended to be used as a feedback channel, where negative acknowledgments (nack) are sent as access bursts at precise times. More specifically, according to the proponents, feedback messages are sent by all interested Mobile Stations (MSs) as access bursts on the CFCH at a precise time: if a MS does not decode the RLC (Radio Link Control) block transmitted at time t, it will send an access burst at time t+Δt; if a MS successfully decodes the RLC block transmitted at time t, nothing is transmitted on the feedback channel at time t+Δt. The consequence is that, if an access burst is detected at time t+Δt, the network realizes that the block transmitted at time t has not been received (at least) by one MS.
Document Tdoc GP-040724 ("Draft CR to TS 43.246: Outer Coding in the RLC for MBMS"), submitted by Siemens at the GERAN #19 Meeting, held in Cancun, Mexico, from Apr. 19 to Apr. 23, 2004, discloses the use of outer coding using Reed-Solomon codes at the RLC layer for MBMS. According to this document, in the BSS (Base Station Subsystem) an outer coding unit is located between the LLC frame segmentation and the RLC/MAC block buffer, and before block headers (including the BSN, Block Sequence Number) are added to each LLC segment. For a code (n,k), the outer coding unit generates (n−k) parity blocks from k systematic blocks. The headers are then added to each segment sequentially starting with BSN=0. In the MS (Mobile Station), the received RLC/MAC blocks are passed, sequentially, to the outer coding unit together with the BSN. After decoding, the parity blocks are discarded and only the systematic blocks reassembled into LLC frames, which are then passed to the LLC layer.
Document Tdoc GP-041006 ("Draft CR to TS 43.246: User feedback using the CFCH"), submitted by Siemens at the GERAN #19 Meeting, held in Cancun, Mexico, from Apr. 19 to Apr. 23, 2004, discloses an outer coding and a feedback channel used together. In particular, the disclosed feedback channel is the CFCH (see above). In the document, it is disclosed that if outer coding at the RLC layer is used, it is not necessary to send a negative acknowledgement for every RLC block in error. According to the proposal, when outer coding and a feedback channel are used together, systematic and parity blocks are prepared at transmitting side. Then only the systematic ones are initially sent, while the parity ones are used to provide additional redundancy only once a negative acknowledgement is received.
In particular, for a code (n,k) the outer coding unit                generates n−k parity blocks from k systematic blocks        assigns BSNs to the n RLC blocks, with the following rule:                    systematic blocks will be assigned BSN=(M·n, . . . , M·n+k−1)            parity blocks will be assigned BSN=(M·n+k, . . . , M·n+n−1)where M is the outer code block number starting from zero.
Then only (M·n, . . . , M·n+k−1) blocks are initially transmitted, while parity ones are sent only upon feedback reception. Every time a negative acknowledgement—referred to the reception of the systematic blocks—is received, p parity blocks (M·n+k, . . . , M·n+k+p−1) are transmitted (where p is a divisor of n−k). If a further nack is received—referred to the first p parity blocks—other p parity blocks (M·n+k+p, . . . , M·n+k+2·p−1) are sent and so on, until no nack is received or all the n−k parity blocks have been sent.
At the receiving side, every MS will send a negative acknowledgement in the following cases:    1. every time the detection of the header of an RLC/MAC block (with its BSN) fails.    2. when, after detecting (from the BSN) the outer code block number M and outer code segment i (i=1, . . . , n), the MS computes the number of still expected blocks (LastM−i) and realizes that the following condition is true(number of already received RLC blocks)M+(LastM−i)<k             where LastM is the last expected outer code segment for outer code block number M, and is equal to k during the transmission of the k systematic blocks, to k+p during the transmission of the initial p parity blocks, to k+2·p . . . .
Once a nack for block M is sent, a flag is internally set, and no other nack for the same outer code block can be sent during the transmission of the current set of blocks (k systematic, first p parity, second p parity ones, etc.).
Document Tdoc GP-040964 ("MBMS p-t-m channel with feedback"), submitted by Ericsson at the GERAN #19 Meeting, held in Cancun, Mexico, from Apr. 19 to Apr. 23, 2004, discloses a proposal for p-t-M with feedback. In such proposal, the MBMS service still uses unacknowledged transmission in the delivery of the MBMS data, but the network can poll for Packet Downlink Ack/Nack reports similar to the RLC acknowledged mode. In particular, the MSs are allocated a number of DL (Downlink) timeslots, e.g. 4. All MSs are allocated the same DL timeslots. The MSs are also allocated an UL (Uplink) timeslot. One of the DL timeslots is the "main" timeslot on which polling requests are sent. MSs are polled for Ack/Nack reports with their unique MS ID. The MS should receive blocks that have a valid MS ID in the TFI (Temporary Flow Identifier) field (a subset of the TFI: e.g. those match 0xxxx). The MBMS MS will first look at the first bit of the TFI. If that is set to 1, the MBMS MS will ignore the block. If it is set to 0, it will receive the block. The MS will also look at the four last bits of the TFI to see if it matches the MS's MS ID. If so, it will send an ACK/NACK report in the UL block indicated by the RRBP.
Document Tdoc GP-040877 ("Proposal for MS counting, addressing and RLC/MAC Ack/Nack management in MBMS"), submitted by Telecom Italia at the GERAN #19 Meeting, held in Cancun, Mexico, from Apr. 19 to Apr. 23, 2004, discloses methods for counting, addressing the MSs and managing the RLC/MAC Ack/Nack in MBMS. According to the proposal, in order to guarantee an adequate perception of the service from the users' point of view, the RLC/MAC mode of operation has to be an acknowledged one. Since all the MSs involved in the specified MBMS are multiplexed on the same timeslots on the DL and addressed via the same TFI, a further identifier for addressing a specific MS is needed, named MFI (Mobile Flow Identity), a new field to be included, when needed, in the extended RLC header of an RLC/MAC block. The global (TFI+MFI) identifier allows the BSS to address a specific MS among those involved in the specified MBMS session. A MS addressed via (TFI+MFI) sends a Packet Downlink Ack/Nack, including its MFI, in order to let the BSS detect the correct identity of the responding MS. The BSS processes all the Packet Downlink Ack/Nack messages received within a request period from all the MSs, in order to manage retransmissions of data blocks. The retransmissions on the BSS side may be performed according to an exhaustive algorithm, in which all the radio blocks referred to as Nacked in any received Packet Downlink Ack/Nack are retransmitted, or to a selective algorithm, based on the overall number of Nacked radio blocks, on a threshold relevant to the percentage of MSs requesting the retransmission of a specific radio block and on the MFI of the MSs requesting the retransmissions.

Method and system for efficient distribution of multicast services in a mobile network


A signal driver circuit having an adjustable output voltage for a high-logic level output signal. The signal driver circuit includes a signal driver configured to output a first logic level signal having a first voltage and output a second logic level signal having a second voltage according to an input signal. A voltage controlled voltage supply coupled to the signal driver provides the first voltage for the first logic level signal. The magnitude of the first voltage provided by the voltage controlled voltage supply is based on a bias voltage. A bias voltage generator can be coupled to the voltage controlled voltage supply to provide the bias voltage.

Many of today's electronic systems are portable and provide users with mobility and ease of transport. Laptops, cellular phones, digital cameras, portable gaming systems, handheld GPS receivers, are just a few examples of portable electronic systems. All of these systems have become increasingly lighter and smaller in form factor, while at the same time, however, these systems have ever greater performance than their predecessors. The increased performance typically has come at the expense of greater power consumption. Since these systems rely on battery power, system designers make an effort to design systems for low power consumption so that the systems can be operated for a greater length of time before replacing or recharging the battery.
As part of the effort to design lower power electronic systems, system designers build these systems utilize components and circuitry that operate with lower power consumption. An example is to include a memory system that has low power consumption since today's electronic systems nearly universally include memory systems for storing data that are used during operation. The tradeoff between operating at lower power while maintaining or improving performance is a difficult one since greater memory capacity or improved speed typically come at the cost of additional circuitry, which translates into additional power consumption. As a result, memory system designers are continually looking for creative solutions to improve power consumption, but at the same time, without compromising performance.

Signal driver circuit having adjustable output voltage for a high logic level output signal


A small first level cache and large second level cache support a central processor in accessing necessary data for processing. The second level cache holds tag address words each having two status bits V and R. The V bit indicates validity/invalidity status while the R bit informs the second level cache of the validity/invalidity status of the corresponding address in the first level cache. As a result of the status information between the two caches, the spy-snoop operation and invalidation operation cycles are minimized as to the use required of the processor bus, enabling higher efficiency processor operations. Utilization is made of a smart-fill algorithm which selects the address locations for placement of new data in a second level cache for a Write operation and after a Read-Miss by analyzing the status values (V,R) for each address in order to minimize the overwriting of valid cache data.

FIG. 3A illustrates a basic picture of a computing system which includes a Central Processing Module 10, an Input/Output Module or Modules 50, and a Main System Memory Module 40 all interconnected by dual redundant system busses 22a and 22b. This configuration might be considered typical of a general computer system.
FIG. 3B is an illustration of the Central Processing Module (CPM) pathway with a cache memory module 19 added in order to enhance system performance. Whenever the processor 14 needs data from main memory 40, the cache memory unit 19 is the first line of resource for this data. An efficient cache design will, on average, contain the requested processor information about 90% of the time. If the cache memory 19 does not have the required information in its latest, most valid state, then the data must be accessed from the system Main Memory 40 over some system bus mechanism such as the processor bus 14b and the dual redundant system busses 22a, 22b. In this latter situation requiring main memory access, this, of course, involves a longer period of time and thus slows down the processor operation than if the processor were able to immediately retrieve the requested data from the cache memory 19 via the processor bus 14b.
FIG. 3C shows the elements of the Central Processing Module 10 in greater detail. Here, the processor 14 connects to the processor bus 14b, while the processor 14 itself has its own first level cache 19c1, but then can also access, via processor bus 14b, the second level cache module 19c2. The processor bus 14b also connects through a unit designated the Data Path Array 20, if there is a requirement for access to the system busses over to main memory. Here, the cache memory module 19 of FIG. 3B is illustrated as two separate units. The first unit designated the first level cache 19c1 is shown internally to the processor 14. The second level cache module 19c2 is shown connected to the processor bus 14b.
In order to gain higher system performance, multi or double-levels of cache are often used. When the processor 14 needs memory data, the first level cache 19c1 is the first resource that the processor 14 will seek. If the first level cache 19c1 does not have the information requested, then the processor will access the second level cache 19c2 to try to see if the requested data is available. Finally, if neither one of the cache units have the data needed, then of course, a much slower cycle of action is required for the processor to access main system memory in order to get the required data. Typically, the first level cache unit 19c1 is quite small and may even be integrated into a processing chip. Then typically, the second level cache 19c2 is larger in storage capacity and will be often external to the processor unit 14 as indicated in FIG. 3C.
Also seen in FIG. 3C is a unit called the "Snoop Logic 23s". This logic monitors both system busses 22a and 22b for any operation that may modify data in any one of the memory locations, that is to say, this is typical of write-type operations. The snoop block 23s captures the address values for all of these system bus operations (writes), queues them up, and passes them on to the second level cache 19c2 at a convenient time for subsequent use or investigation. The snooping (or spying) function is necessary to assure data coherency in the cache structures. When the cache investigates each of the addresses that have been queued within it, it checks the cache tag unit to see if the cache currently contains a valid version of that particular memory address. If it does not contain a valid version, then that particular queued address is discarded. If the cache unit does contain a copy of the queued address, then the cache will operate an "invalidation" operation where it marks, in its cache tag unit, that locational address as "invalid".
With the multiple levels (2 levels) of cache structures as shown in FIG. 3C, there is an additional complication in regard to the "invalidation cycle process" which is added. In this case, it is necessary for the first level cache tag unit in 19c1 to also investigate each of the queued spy address values as well as the second level cache 19c2. This necessitates the transfer of all queued address values on the processor bus 14b up to and over to the processor first level cache 19c1. Thus, this requires and becomes a significant amount of extra traffic on the processor bus 14b. When the processor bus 14b is busy carrying an invalidation address, the processor 14 cannot use the bus for its real processing operations. The present system and method presents a method to reduce the processor bus traffic on bus 14b, due to invalidations, and thus to increase the amount of work that the processor can get done and increase its efficiency.
FIG. 3D is an expanded view of the second level cache memory, 19c2, design to show the operative elements of a cache memory module. The processor bus 14b is made of two subordinate busses indicated as the address bus 14ba and the data bus 14bd. The cache module is shown operatively as having three major block units. These units include a Tag RAM 19ta, a Data RAM unit 19da, and a Cache Control block unit 16cc. The Cache Control unit 16cc is actually a part of the programmable array logic, Control PAL 16 which was previously seen in FIG. 3C. The Tag RAM block in all cache designs, holds the addresses, (indexes) of the data contained within the cache at any particular moment. The Tag addresses in 19ta provide the means by which comparisons of requested processor address values can be made with the held address values in the Tag RAM 19ta. When a match occurs, this is called a cache "hit", because it indicates that the cache does indeed contain valid data for that particular specified address.
The Data RAM block 19da is the storage area for all of the data held within the cache module at any particular moment. These type of Data RAMs are generally expansive and very fast operating devices which can return data to the processor on "cache hit" conditions. The Cache Control block unit 16cc, is used to monitor the Tag RAM "hit" condition, and further controls the reading out of the Data RAMs 19da. When a Tag "miss" condition occurs (i.e., not a "hit"), then this Cache Control block controls the writing into the Data RAMS 19da of any data received subsequently from the main memory 40.

Processor bus traffic optimization system for multi-level cache utilizing reflection status bit to indicate data inclusion in a higher level cache


In accordance with an aspect of the invention, a method is provided for fabricating a semiconductor chip including a trench capacitor. In such method, a monocrystalline semiconductor region can be etched in a vertical direction through an opening in a dielectric layer to form a trench exposing a rough surface of monocrystalline semiconductor material. The trench has an initial lateral dimension in a first direction transverse to the vertical direction. The semiconductor material exposed at the surface of the trench then is etched in a crystallographic orientation-dependent manner to expose a multiplicity of crystal facets of the semiconductor material at the trench surface. A dopant-containing liner may then be deposited to line the surface of the trench and a temperature of the substrate then be elevated to drive a dopant from the dopant-containing liner into the semiconductor region adjacent to the surface. During such step, typically a portion of the semiconductor material exposed at the wall is oxidized. At least some of the oxidized portion is removed to expose a wall of an enlarged trench, along which wall a dielectric layer and conductive material are formed in order to form a trench capacitor.

1. Field of the Invention
The present invention relates to semiconductor devices and their manufacture, and more specifically to a structure and method of making a semiconductor chip having a trench capacitor.
2. Description of the Related Art
One of the challenges of fabricating capacitors within the active device regions of semiconductor chips is to obtain sufficient capacitance while minimizing the area of the active semiconductor device layer occupied by the capacitor. One known way to reduce the semiconductor device area occupied by the capacitor is to use a trench capacitor. A trench capacitor has length extending in a vertically downward direction with respect to the semiconductor device layer, so that the long dimension of the trench capacitor extends out of the plane in which the semiconductor device layer extends.
A known way of increasing capacitance is to form the trench capacitor using a "bottle" process. In such process, first a relatively narrow trench is formed that extends through the active semiconductor device layer. Then, subsequent processing applied to a lower portion of the trench underlying the active semiconductor device layer to enlarge the lower portion of the trench, thus forming a capacitor having a larger surface area and capacitance.
Still further improvements in the fabrication and structure of a trench capacitor would be desirable.

Bottle-shaped trench capacitor with enhanced capacitance

International Business Machines Corporation


In the manufacture of a battery cell, a shear thinning cathode material that has been mixed to a homogeneous state is transported to an extrusion opening while being subjected to a non-decreasing shear stress. The shear thinning cathode material is extruded onto a conductive substrate material at a constant rate. An electrolyte material is applied over the shear thinning cathode material, and an anode material is applied over the electrolyte material.

1. FIELD OF THE INVENTION
The present invention relates to an apparatus and method for extruding and, more particularly, to an apparatus and method for extruding a shear thinning material.
2. STATE OF THE ART
In recent years, workers in the battery art have begun to understand and recognize the advantages of batteries manufactured from laminates including solid polymer electrolytes and sheet-like anodes and cathodes over conventional liquid electrolyte batteries. The advantages include lower battery weights than batteries that employ liquid electrolytes, longer service life, relatively high power densities, relatively high specific energies, and the elimination of the danger associated with batteries containing spillable liquid electrolytes such as acids. Until recently, commercial use of such batteries was limited by, among other things, the inability of such batteries to operate effectively except at relatively high temperatures.
More recently, however, laminate batteries using polymer electrolytes have been developed which possess good performance characteristics at or below room temperature. For example, in U.S. Pat. No. 4,925,751 to Shackle et al., a battery cell is described having good performance characteristics across a broad range of temperatures, including room temperature. The battery cell utilizes a current collector, such as a sheet of conductive metal foil, upon which is coated a thin layer, generally between 25 and 250 microns, of a cathode material.
The cathode material described, for example, in U.S. Pat. No. 4,925,751 to Shackle et al., is formed from a mixture of active cathodic material (usually a V.sub.3 O.sub.8 or a V.sub.6 O.sub.13 material), a conductive filler material (usually carbon particles), and an ionically conductive electrolyte material. In practice, such cathode material is paste-like in consistency and coating on the current collector is performed by conventional coating techniques such as a doctor blade or an extrusion method. The cathode material exhibits non-Newtonian fluid characteristics. Particularly, the cathode material is a shear thinning material, i.e., its viscosity decreases as the material is subjected to increasing shear stress. In still other words, the flow resistance of such materials decrease as shear increases. Apparatuses and methods for extruding a shear thinning cathode material must, therefore, be designed to accommodate this fluid characteristic.
In conventional mixing and extruding systems, a material is mixed to a homogeneous state and then is transported by a positive displacement pumping mechanism. The positive displacement pumping mechanisms typically transport the material under pressure through a narrow conduit to a reservoir having a larger cross-sectional area than the conduit. From the reservoir, the material is extruded through an extruder nozzle. In such systems, even if the rate of transport of the homogeneous material is somewhat irregular, the reservoir provides a consistent rate of extrusion.
Where, however, a shear thinning material is being mixed and extruded in such an apparatus, transport of the shear thinning material is substantially stopped when the material ceases to be under constant or increasing shear, i.e., when the homogeneous shear thinning material is expanded into the larger volume of the reservoir. In production of laminate batteries, it is necessary to achieve a constant thickness electrode laminate layer on a substrate to attain acceptable results in a battery and, consequently, a shear thinning electrode material must be extruded onto a substrate at a substantially constant rate. It is, therefore, desirable to provide an apparatus and method for mixing and extruding a shear thinning electrode material for a laminate battery in which electrode material is mixed to a homogeneous state and then transported while undergoing a constant or increasing shear to a point of extrusion such that it is extruded at a constant rate.

Apparatus and method for extruding shear thinning material


Methods, apparatus, systems, and articles of manufacture to monitor health information of a valve are disclosed. An example system includes a field device in a process control network to monitor a valve, and a valve health monitor to be communicatively coupled to the field device to obtain operational health information from the field device when the valve is commanded to move from a first position to a second position, the first position opposite the second position, identify a condition of the valve based on the operational health information, and send an alert via the process control network based on the condition of the valve.

In recent years, process control systems, like those used in chemical, petroleum, and/or other processes, have grown progressively more complex with the proliferation of field devices that include more processing power than their predecessors. Current generation process control systems include a greater number and variety of field devices or instruments for measuring and/or controlling different aspects of a process control environment. In addition to utilizing field devices to monitor and/or control core processes, field devices have been increasingly used for peripheral tasks such as prognostic health monitoring.
Process control systems in which field devices fail during operation can experience increased periods of downtime. Field device failure during operation can also create hazardous operating conditions if the failed field devices provide erroneous or inaccurate data to the process control system. The consequences of failed field devices (e.g., motors, sensors, valves, etc.) that provide electronic feedback to controllers can be mitigated by performing a controlled shut down of the process equipment or by bypassing the inputs of the failed field devices to corresponding controller algorithms.
Field devices within the process control system may be located in difficult environments such as areas with extreme vibration, high pressure, and/or wide temperature ranges that may cause accelerated failure. With the implementation of increasingly powerful field devices, process control systems can monitor the prognostic health of the field devices in these difficult environments. Monitoring field devices using peripheral algorithmic routines can be used to predict potential failures and enable technicians to replace the potentially faulty field devices during periodic maintenance as opposed to halting operation of the system to replace field devices.

Methods and apparatus to monitor health information of a valve


The present invention pertains to transgenic plants comprising nucleic acid molecules comprising nucleotide sequences that encode RAR1 proteins involved in disease resistance, and the RAR1 polypeptides. The invention particularly relates to methods of altering the expressing nucleic acid molecules encoding RAR1 proteins in transgenic plants to alter the level disease resistance, and to transgenic plants, progeny and seed therefrom, having altered enhanced disease resistance. The invention further relates to methods of enhancing expression of R resistance genes, disease resistance signal transduction genes, genes involved in mediating disease resistance or involved in the synthesis of molecules mediating disease resistance. The invention also relates to methods of regulating the expression of other coding sequences of interest by increasing the expression of the nucleic acid molecules of the invention.

Crops are biological monocultures under severe disease pressure from pathogenic bacteria, fungi and viruses. Cereal crops are the primary source of food for humans and their animals. The yield loss due to cereal plant diseases varies by crop, season and locale, but is estimated to exceed $100 billion worldwide (Brears and Ryals (1994) Agro-Food-Industry Hi-Tech Jul./Aug. 10–13). Two major approaches to solve the problem are pesticide applications and the use of resistant germplasm. The source of this resistant is often wild species related to the crop plant (exotics), and such genes are introduced into new crop cultivars by laborious and time-consuming genetic backcrossing, to retain the favorable characteristics of the crop parent.
Effective genetic disease resistance in plants is governed by resistance (R) genes. Historically, introgressed exotic germplasm conferring disease resistance has been found to contain novel plant R genes. Plant R genes confer resistance to pathogen races bearing a cognate avirulence (avr) gene. The absence of either member of a cognate R/avr gene pair can result in disease. There are multiple R/avr cognate gene pairs in the plant and the pathogen, respectively, varying in the strength of the defense response they elicit.
The RAR1 gene of barley functions in disease resistance mediated by a subset of R genes (Peterhansel et al. (1997) Plant Cell 9: 1397–1409). RAR1 has been cloned and encodes a protein with two novel Zn-binding (named CHORD) domains (Shirasu et al. (1999) Cell 99:355–366). This group also reported highly conserved RAR1 homologs in humans, Caenorhabitis elegans, Drosophila melanogaster, as well as in the model dicot Arabidopsis thaliana.
Given the high degree of genomic synteny between cereals (Devos and Gale (2000) Plant Cell 12: 637–646), we reasoned that a full-length rice RAR1 gene should both exist and function in disease resistance in that species. Using our proprietary rice genomic database, a single rice RAR1 cDNA was cloned. The gene functions in mediating resistance by a subset of R genes in response to certain pathogen races. Over-expression of RAR1 confers enhanced disease resistance by mechanisms which are currently unclear.

Transgenic plants compromising nucleic acid molecules encoding RAR1 disease resistance proteins and uses thereof


A hydraulic wrench is provided of minimum external dimensions and yet constructed in a manner to be capable of exerting relatively high torsional forces. The wrench is constructed to be driven by a hydraulically reciprocal piston carrying a rack gear thereon with the rack gear meshed with a reciprocal sector gear having a pawl pivotally supported therefrom for driving a ratchet-type power wheel of the wrench. The wrench is provided with a variably positionable and reversable reaction bar or abutment assembly on the end thereof remote from the power wheel and the wrench further includes a secondary deactivatable ratchet pawl for preventing reverse rotation of the main ratchet-type drive wheel of the wrench.

1. Field of the Invention
This invention relates to a hydraulic wrench utilizing a reciprocal driven rack gear to oscillate a pinion gear segment including a one way driving connection with a ratchet gear through a pawl pivotally supported from the pinion gear segment, the hydraulic wrench being constructed of minimum dimensions for maximum power and including structure by which the wrench may be utilized to reversely drive a bolt or nut. Further the wrench is equipped with a variably positionable reactionary force abutment to facilitate ease in utilization of the hydraulic wrench.
2. Description of Related Art
Various different forms of hydraulic wrenches including some of the general structural and operational features of the instant invention heretofore have been provided such as those disclosed in U.S. Pat. Nos. 3,972,242, 3,930,776, 4,266,444, 4,336,727, 4,794,825, 5,090,273 and 5,097,730. However, these previously known forms of hydraulic wrenches and other similar devices do not include or suggest the overall combination of structural and operational features included int he instant invention.


A battery monitoring system includes a current sensor and a voltage sensor coupled to a battery cell. It also includes a microcontroller that opportunistically computes many estimates of the cell's ohmic resistance and filters these estimates to arrive at a stable value. Each estimate is traditionally computed from a delta change in voltage divided by delta change in current measured before and after a significant change in current magnitude. An improvement in accuracy of each resistance estimate is achieved by only computing an estimate if the rate of change of voltage and the rate of change of current exhibited by the values making up the delta voltage and delta current are tightly consistent and of the same polarity. This approach significantly minimizes errors induced in estimates not preselected in this manner by the different and also asynchronous sample rates of the cell's voltage and current.

Referring to FIG. 2, an equivalent circuit model 60 used in representing an electrical response of a battery cell 12 to a flowing current is illustrated. One of the main elements of the equivalent circuit model 60 is the DC resistance value R0 (also referred to as an "ohmic resistance value" herein) of the resistor 80. Pursuant to Ohm's Law, the voltage drop across the resistor 80 is a function of current through the resistor 80 times the resistance value of the resistor 80. This voltage drop, and associated i2R power loss, is power that is unavailable to the intended application of the battery call 70. At the beginning of life of the battery cell, the ohmic resistance value R0 is at a respective lowest value. However, aging of the battery cell, due to calendar age and current throughput, results in a growing value of R0. Thus, one of the tasks of a microcontroller is to continuously monitor/estimate the growing value of R0 because of its major impact on the ability of the system to deliver power.
Estimation of R0 is based on Ohm's Law Vvoltage=Icurrent*Rresistance.
Referring to FIGS. 3 and 4, an exemplary current curve 250 and an exemplary voltage curve 260 are illustrated. With a value of 0 amps current at times t=0 (e.g., time=0-25 milliseconds in FIGS. 3 and 4), a voltage drop across resistor 80 is 0 volts so the Open Circuit Voltage at the +/−terminals is effectively the same as that of the battery cell itself. An instantaneous change in current at t=25 milliseconds, due to the connection of a load at the battery cell terminals at t=1 (e.g., time t=25 milliseconds in FIGS. 3 and 4), will cause the voltage at the terminals to drop by the value=>Icurrent*Rresistance. This value can be determined by the difference between the Open Circuit Voltage (OCV)=Vt=0 and the new voltage at the terminals Vt=1.
Knowing these values, the voltage drop across resistor 80 is equal to (Vt=1−Vt=0) or ΔV and the value of current through resistor 80 or It=1 then R0 can be determined as R0=ΔV/It=1.
More generally, at any time t, R0=ΔV/ΔI
where ΔV=Vt=(i)−Vt=(i-1)                 ΔI=It=(i)−It=(i-1); and i>=1
This form of Ohm's Law expression is a mathematically correct relationship. However, there are practical limitations to applying this in a real time embedded software system. The expression R0=ΔV/ΔI is only ideally true for instantaneous measurements of cell voltage immediately following changes in current.
At any amount of time Δt>0 (after the change in the value of current I), the dynamic aspects of the Equivalent Circuit Model (R1, R2, R3, C1, C2, C3) also impact the relationship between the current I and the cell voltage measured at the terminals.
If Δt is significant, then the relationship R0=ΔV/ΔI is no longer valid.
The practical difficulty in computing R0=Vt=(i)−Vt=(i-1)/It=(i)−It=(i-1), where the time Δt between the acquisition of the value Vt=(i-1) after the acquisition of the value It=(i-1) and also the time Δt between the acquisition of the value Vt=(i) after the acquisition of the value It=(i) are both at near 0 values, is the fact that the hardware and software processes involved all take non-zero amounts of time. These actual analog values of voltage and current must be acquired by the hardware, converted from analog to digital form in the hardware, the digital form of these values must be input into the computer software's domain, then these values are passed to the software processes that compute the R0 estimates.
In addition to the non-zero amount of time involved in these steps, the steps themselves are often executed at different frequencies. The collection of values of current may take place at one rate, such as 200 times per second (200 Hz). The collection of values of cell voltages may take place at a different rate, such as 10 Hz. Finally, the computation of estimations of R0 values make take place at yet another rate—for example 5 Hz.
In addition to these current and cell voltage timing synchronization issues, each of the signal's values include error components due to inherent electrical noise in the hardware sensors that are used to acquire samples of current and cell voltage for each cell.
A battery monitoring system needs to have an accurate understanding of the R0 ohmic resistance values of each battery cell in a battery pack. The inventor herein has recognized that in order to gain this knowledge, a battery monitoring system will frequently compute estimates of the R0 values of each battery cell and smooth the results of these estimates using a smoothing filter or slew rate limiter in order to diminish or cancel out the effects of the various types of noise-related errors in these estimates—with the assumption that the errors are basically Gaussian in nature (e.g., as likely to be inaccurately over estimating as inaccurately underestimating the R0 values). Further, the inventor has conceived a battery monitoring system that identifies and selects good candidate current and cell voltage pairs for use in R0 estimate calculations, and filtering out current and cell voltage pairs that have identifiable synchronization and electrical-noise related errors, to obtain a filtered ohmic resistance value.


A hole transport layer in an organic electroluminescent device is made of a material containing at least a ditriphenylaminestyryl derivative expressed by the general formula: ##STR1## where A is selected from the group consisting of substituted and non-substituted alkylidene groups, cycloalkylidene groups, oxygen atom, sulfur atom, amino groups; where Ar.sup.1, Ar.sup.3, Ar.sup.4 and Ar.sup.5 are selected from the group consisting of substituted and non-substituted arylene groups; where Ar.sup.2 and Ar.sup.6 are one selected from the group consisting of substituted aryl groups and non-substituted aryl groups; and where X and Y are substituted groups expressed by the formula: ##STR2## where Ar.sup.7 and Ar.sup.8 are selected from the group consisting of substituted aryl groups and non-substituted aryl groups; and where R.sup.1 is one selected from the group consisting of hydrogen atom, halogen atom, hydroxyl groups, substituted and non-substituted amino groups, substituted and non-substituted alkoxy groups, substituted and non-substituted alkyl groups having 1-6 carbon atoms.

The present invention relates to an organic thin film electro-luminescence device and an organic thin film electro-luminescence device having pixels arranged in a matrix.
The organic thin film electro-luminescence device has an anode, a cathode and a light emission layer. Holes are supplied from the anode and injected into the light emission layer. Electrons are supplied from the cathode and injected into the light emission layer. As a result, there appears, in the light emission layer, recombinations of the injected electrons and holes. The recombinations of the electrons and holes cause energy-excited states which results in light emissions. The energy-excited states are dependent upon the materials contained in the light emission layer. The organic thin film electro-luminescence device is designed so that an organic light emission layer, showing a strong luminance, is sandwiched between the anode and the cathode. However, depending upon the material constituting the light emission layer, various design modifications of the material constituting the hole transport layer of the organic thin film electroluminescent device are required to obtain optimal luminance efficiency, durability and driving stability. It has been disclosed in the prior art that the organic thin film electroluminescent device, having a hole transport layer and an electron transport layer, is effective in improving luminance efficiency and a driving stability. Further more, doping of guest molecules into the organic emission layer is also effective to improve luminance efficiency and driving stability. In Applied Physics Letters, Vol. 51(12), 21 Sep. 1987, Tang and VanSlyke reported that an organic thin film electroluminescent device exhibited a luminance of over 1000 cd/m.sup.2 and a maximum luminance efficiency of 1.51 m/W at a driving voltage of less than 10 V. Tang and VanSlyke teach that it is possible to develop an organic thin film electroluminescent device that is driven to high brightness at a low voltage, and that the efficiency of the device is dependent upon both the materials and structural features. Namely, it is important that the light emission layer is made of tris(8-hydroxyquinolinolate)aluminum, and further that the hole transport layer placed between the anode and the light emission layer is made of derivatives of triphenyldiamine. The hole transport layer of the derivatives of triphenyldiamine improves the efficiency of the injection of holes into the light emission layer and also determines the probability of the injections of electrons into the light emission layer. As a result, the efficiency in the generation of excitons in the light emission layer is improved. The hole transport layer of the derivatives of triphenyldiamine contributes to confine the generated excitons in the light emission layer.
The improvement of the hole transport layer may not only provide an improvement in the luminance efficiency but may also ensure the driving stability of the above device. It has been proposed that double hole transport layers provide a significant improvement in durability. In this regard, the U.S. Pat. No. 4,720,432 discloses the following. A hole injection layer of a porphyrin system is provided on the anode. A hole transport layer made of derivatives of triphenyldiamine is provided on the hole injection layer. The organic thin film electroluminescience device, having those structures, exhibited a continuous luminance for about 500 hours at an injection current of 5 mA/cm.sup.2 at a voltage of 7.2 V. In the other device without the above structural modifications, the driving voltage is generally around 6V.
In Applied Physics Letters, Vol. 65, p. 807, 1994, Shirota et al. reported as follows. There are provided two hole transport layers. The first hole transport layer, in contact with the anode, is made of -conjugated starburst molecule, 4,4',4'-tris(3-methylphenyl-phenylamino)triphenylamine. The second hole transport layer, in contact with the light emission layer, is made of N,N'-diphenyl-N,N'bis(3-methylphenyl)-1,1'-biphenyl!-4,4'-diamine. The combination of those materials may cause the light emission layer of tris(8-hydroxyquinolinolate)aluminum to exhibit a high luminance efficiency. It was confirmed that an initial luminance is 300 cd/m.sup.2 and a half-value period is 300 hours at the constant current driving. The second hole transport layer of N,N'-diphenyl-N,N'bis(3-methylphenyl)-1,1'-biphenyl!-4,4'-diamine, provided between the hole transport layer of the -conjugated starburst molecule and the light emission layer, forms a gentle slope barrier, that holes will experience in the injection into the light emission layer. The gentle slop barrier improves the efficiency of the injection of holes into the light emission layer, which, in turn, improves luminance efficiency. In summary, the hole transport layer made of -conjugated starburst molecule, 4,4',4'-tris(3-methylphenyl-pheny-lamino)triphenylamine contributes to driving stability. The second hole transport layer made of N,N'-diphenyl-N,N'bis(3-methylphenyl)-1,1'-biphenyl!-4,4'-diamine may contribute rising the efficiency of hole injection, or the efficiency of the luminance.
In Polymer Preprints Japan, Vol. 42, p. 615, 1993, Ito et al. report other electroluminescent device as follows. First and second hole transport layers are in turn provided on an indium-tin-oxide substrate. The first hole transport layer is made of a lyphosphazenpolymer, having as side chains copper phthalocyanine and triphenylamine. The second hole transport layer is made of N,N'-diphenyl-N,N'bis(3-methylphenyl)-1,1'-biphenyl!-4,4'-diamine. A light emission layer is provided on the second hole transport layer, wherein the light emission layer is made of tris(8-hydroxyquinolinolate)aluminum doped with quinacridone. After this device was placed in a room for two months, it was continuously driven by a constant current. The device exhibited an initial luminance of 587 cd/m.sup.2 and a half-value period of 166 hours.
In order to develop the organic thin film electroluminescent device, it is important not only to improve the materials for the device, but also to improve the structure of the device. One of the important issues of the device, to be solved by the development, is how to realize a multiple color display with a possible low cost.
One of the organic thin film electroluminescent devices having high fine matrix type display is disclosed in the Japanese laid-open patent application No. 5-253866. The disclosed organic thin film electroluminescent device has a driving circuit, which includes novel thin films transistors serving as switches. This device may suppress the deterioration in the degree of the luminance, caused by a high duty ratio of pulses for driving the device. This means that the organic thin film electroluminescent device, having an increased number of the pixels, may be driven without the deterioration of the degree of luminance.
As described above, the development of the organic thin film electroluminescent device spreads over the improvements of the materials, the structure and the driving performance.
The organic thin film electroluminescent devices described above are designed to be continuously driven by the constant currents. This causes the following problems. First one is a relatively large reduction in intensity of the luminance after a long time passes, thereby the voltage level necessary for the luminance is increased and the luminance efficiency is dropped. As the long time passes, there becomes apparent a variation in intensity of the luminance of the device. One of the cuses of those undesirable phenomenon's is in a crystallization of the material constituting the hole transport layer of the device. The crystallization is caused by heat generated in driving the device. The crystallization is also caused by having a long time pass. The crystallization causes electric field to be applied but not uniformly on the layers between the anode and the cathode. This results in a difficulty in achieving the uniform luminances of individual pixels of the device.
From the above description, it can been seen that, in order to settle the above problems, it is necessary to prevent the crystallization of the material constituting the hole transport layer of the device. It has been proposed by Tsuruoka et al. that a bis-triphenylaminestyryl compound is used as a material of the hole transport layer of the organic thin film electroluminescent device because the bis-triphenylaminestyryl compound possesses a high hole mobility and a high glass-transition temperature. The glass-transition temperature is defined as a temperature, over which the crystallization appears. The high glass-transition temperature may prevent the crystallization, due to the heat generation, of the material constituting the hole transport layer. The high hole mobility is one important factor for causing a high efficiency of injection of holes into the light emission layer. These are reported by Tsuruoka et al. in Japan Chemical Society, 1994. The hole transport layer is so provided as to be in contact with the anode. The emission layer is provided between the hole transport layer and the cathode. This device, when driven at the constant current, exhibits the luminance, characterized by almost the same half-value period as the well known device, having the hole transport layer made of N,N'-diphenyl-N,N'bis(3-methylphenyl)-1,1'-biphenyl!-4,4'-diamine. The above device reported by Turuoka et al. exhibits the luminance at a half intensity, per a unit current-density, of the luminance intensity of the above well known device. The cause of the small intensity of luminance per a unit current-density is in the facts that excitons generated in the light emission layer are quenched but not blocked by the hole transport layer, and that some of the electrons injected in the light emission layer tend to move to the anode side without exhibiting the recombination with holes in the light emission layer.
Accordingly, it would be important for the organic thin film electroluminescent device to ensure a high efficiency of transport of holes in the hole transport layer. It is also important to ensure a high efficiency of injections of holes into the light emission layer. It is further important to secure a sufficiently high degree of confinement, in the light emission layer, of the excitons, generated in the emission layer, and electrons. The sufficiently high degree of confinement of the excitons and electrons ensures a high probability of recombination of the holes and electrons in the light emission layer. It is moreover important to select the optimum material for the hole transport layer, in consideration of the preventions of any crystallization of the material due to the heat generated by the driving of the device.

Organic thin film electroluminescent device