The present invention provides a process for producing an epoxy resin molding material for semiconductor encapsulation, which is very low in voids generation; a molding material produced by the process; and a semiconductor device obtained by encapsulation with the molding material. That is, the present invention provides a process for producing an epoxy resin molding material for semiconductor encapsulation, which comprises premixing a composition containing at least an epoxy resin, a phenolic resin and an inorganic filler, then subjecting the resulting mixture to grinding by a grinder to obtain a powder having such a particle size distribution that the amount of particles having particle diameters of 250 xcexcm or more is 10% by weight or less, the amount of particles having particle diameters of 150 xcexcm to less than 250 xcexcm is 15% by weight or less, and the amount of particles having particle diameters of less than 150 xcexcm is 75% by weight or more, and thereafter subjecting the powder to melt kneading; a molding material produced by the process; and a semiconductor device obtained by encapsulation with the molding material.

The present invention relates to a process for producing an epoxy resin molding material low in voids generation during semiconductor encapsulation; a molding material produced by the process; and a semiconductor device obtained by encapsulation with the molding material.
For encapsulation of semiconductor elements such as IC, LSI and the like, epoxy resin molding materials, which are transfer-moldable, are widely used in view of the reliability and productivity of the encapsulation with these materials.
Epoxy resin molding materials are constituted by an epoxy resin, a phenolic resin, a curing accelerator, an inorganic filler, a releasing agent, a flame-retardant, a coupling agent, etc., and are generally produced by weighing individual raw materials by given amounts, premixing the raw materials using a stirrer and mixer such as Henschel mixer or the like, and then subjecting the resulting mixture to melt kneading using a hot kneader such as single-screw kneader, double-screw kneader, hot rolls, continuous kneader or the like to mix and disperse the raw materials uniformly.
Meanwhile, electronic appliances are becoming increasingly small, light and functional and, accordingly, the semiconductor packages used therein are becoming increasingly small, thin and narrow in pitch. In such a movement, epoxy resin molding materials used for semiconductor encapsulation are strongly required to have improved resistance to soldering heat and improved humidity resistance, since these resistances are relevant to the reliability of the semiconductor package obtained by encapsulation.
Hence, the amount of inorganic filler in epoxy resin molding material is being increased in order to reduce the stress and hygroscopicity of semiconductor package inside. However, this increase in amount of inorganic filler in epoxy resin molding material reduces the flowability of epoxy resin molding material during encapsulation and makes more serious the problems in molding such as deformation of lead frame, deformation of gold wire, generation of voids and the like.
As a countermeasure for the above, there is being continued an attempt of optimizing the shape and particle size distribution of inorganic filler, or an attempt of making very small the viscosity of resin components (e.g. epoxy resin and phenolic resin) at an encapsulation temperature to allow the resulting molding material to maintain a required flowability and have an improved chargeability. Nevertheless, the task of reducing voids is difficult to achieve and is becoming more and more important.
The voids of epoxy resin molding material are thought to be reduceable by increasing the degree of kneading of molding material during the step of melt kneading to increase the wettability between resin components and inorganic filler in molding material or the dispersibility of inorganic filler. However, increase in the degree of kneading during melt kneading step alone accelerates the curing of molding material by the heat applied in the step and, as a result, impairs the flowability of molding material.
Hence, there were disclosed a method which comprises selecting raw materials causing no curing in the step of premixing, melt-mixing them at a temperature higher than their melting or softening point, and then subjecting the resulting mixture to melt-kneading (e.g. JP-A-56-149454, JP-A-4-59863 and JP-A-3-195764); a method which comprises selecting an optimum hot kneader or optimum kneading conditions to minimize the proceeding of curing in the hot kneader and increase the wettability between resin components and inorganic filler in molding material or the dispersibility of inorganic filler (e.g. JP-A-9-52228); and so forth.
However, melt-mixing in the premixing step at a high temperature has restricted the raw materials usable; and selection of an optimum kneader or optimum kneading conditions alone has made it difficult to reduce voids generation stably.
Objects of the present invention are to provide a process for producing an epoxy resin molding material for semiconductor encapsulation, which is very low in voids generation; a molding material produced by the process; and a semiconductor device obtained by encapsulation with the molding material.
The present inventors made a research in view of the above situation. As a result, the present inventors newly found out that voids generation can be reduced remarkably by making raw materials into a finer and more homogeneous dispersion after their premixing but before their melt kneading. The present invention has been completed based on the finding.
The first aspect of the present invention lies in a process for producing an epoxy resin molding material for semiconductor encapsulation, which comprises premixing a composition containing at least an epoxy resin, a phenolic resin and an inorganic filler, then subjecting the resulting mixture to grinding by a grinder to obtain a powder having such a particle size distribution that the amount of particles having particle diameters of 250 xcexcm or more is 10% by weight or less, the amount of particles having particle diameters of 150 xcexcm to less than 250 xcexcm is 15% by weight or less, and the amount of particles having particle diameters of less than 150 xcexcm is 75% by weight or more, and thereafter subjecting the powder to melt kneading.
The second aspect of the present invention lies in a process for producing an epoxy resin molding material for semiconductor encapsulation, which comprises adding, to the composition set forth in the first aspect, at least one kind selected from a coupling agent, a curing accelerator, a flame retardant, a releasing agent, an ion-capturing agent, a coloring agent and a stress-reducing agent, premixing the resulting composition, then subjecting the resulting mixture to grinding by a grinder to obtain a powder having such a particle size distribution that the amount of particles having particle diameters of 250 xcexcm or more is 10% by weight or less, the amount of particles having particle diameters of 150 xcexcm to less than 250 xcexcm is 15% by weight or less, and the amount of particles having particle diameters of less than 150 xcexcm is 75% by weight or more, and thereafter subjecting the powder to melt kneading. In the first and second aspects, preferably the acetone-insoluble portion of the powder comprises particles having particle diameters of 212 xcexcm or more in an amount of 0.5% by weight or less.
The third aspect of the present invention lies in a process for producing an epoxy resin molding material for semiconductor encapsulation, which comprises adding, to the composition set forth in the first aspect, a coupling agent, a curing accelerator, a flame retardant, a releasing agent, an ion-capturing agent, a coloring agent and a stress-reducing agent, premixing the resulting composition, then subjecting the resulting mixture to grinding by a grinder to obtain a powder having such a particle size distribution that the amount of particles having particle diameters of 250 xcexcm or more is 10% by weight or less, the amount of particles having particle diameters of 150 xcexcm to less than 250 xcexcm is 15% by weight or less, and the amount of particles having particle diameters of less than 150 xcexcm is 75% by weight or more, and thereafter subjecting the powder to melt kneading.
The fourth aspect of the present invention lies in an epoxy resin molding material for semiconductor encapsulation, produced by a process according to any of the first to third aspects.
The fifth aspect of the present invention lies in a semiconductor device obtained by encapsulating semiconductor elements with an epoxy resin molding material set forth in the fourth aspect.
The present invention is described in detail below.
The epoxy resin used in the present invention has no particular restriction as to the kind as long as it has two or more epoxy groups in the molecule and it is solid at ambient temperature. There can be mentioned, for example, bisphenol type epoxy resin, biphenyl type epoxy resin, phenolic novolac type epoxy resin, cresol novolac type epoxy resin and alkyl-modified triphenolmethane type epoxy resin. These resins may be used singly or in admixture.
When there is used a crystalline epoxy resin such as biphenyl type epoxy resin or the like, the epoxy resin preferably has a melting point of 50 to 150xc2x0 C. When the melting point is less than 50xc2x0 C., the temperature of resin increases in premixing, owing to the heat generated by friction and the melting of resin begins, which may deteriorate workability strikingly and reduce productivity.
Meanwhile, when the melting point is more than 150xc2x0 C., melting of epoxy resin in melt-kneading step requires a very high temperature; consequently, it is difficult to suppress the proceeding of curing and it may be impossible to maintain the flowability of molding material at an appropriate level during encapsulation.
The melting point of a resin can be measured easily by an ordinary method of judging the melting point of the resin in glass capillary from its appearance, or by a method using a differential scanning calorimeter.
The phenolic resin used in the present invention has no restriction as to the kind as long as it is solid at ordinary temperature. There can be mentioned, for example, phenolic novolac resin, cresol novolac resin, dicyclopentadiene-modified phenolic resin, phenol aralkyl resin, naphthol aralkyl resin and terpene-modified phenolic resin. These resins can be used singly or in admixture.
The coupling agent used in the present invention has no particular restriction as to the kind, but is preferably a silane coupling agent such as xcex3-glycidoxypropyltrimethoxysilane, xcex3-aminopropyltrimethoxysilane, xcex3-mercaptopropyltrimethoxysilane, vinyltriethoxysilane or the like. The coupling agent used for surface treatment of inorganic filler is more preferably an amino-type silane coupling agent. These coupling agents may be used singly or in admixture. Even when there is used a surface-treated inorganic filler, a coupling agent may be added further in premixing.
The inorganic filler used in the present invention includes a fused silica powder, a crystalline silica powder, alumina, silicon nitride, etc. They may be used singly or in admixture.
An inorganic filler surface-treated with a coupling agent may be used. This surface-treated inorganic filler may be used singly or in admixture of two or more kinds. There may be used a mixture of a surface-treated inorganic filler and a surface-non-treated inorganic filler. The amount of inorganic filler used is preferably 60 to 92% by weight based on total resin composition in view of the balance of moldability and reliability.
The curing accelerator used in the present invention can be a substance capable of accelerating the curing between epoxy group and phenolic hydroxyl group and can be one ordinarily used in a resin for semiconductor encapsulation.
There can be mentioned, for example, 1,8-diazabicyclo(5,4,0)undecene-7, triphenylphosphine and 2-methylimidazole. These may be used singly or in admixture.
The flame retardant used in the present invention can be exemplified by antimony oxides such as antimony trioxide, antimony pentoxide and the like; bromine compounds such as brominated epoxy resin and the like; metal compounds such as aluminum hydroxide, magnesium hydroxide, zinc borate and the like; phosphorus compounds such as phosphoric acid ester, red phosphorus and the like; and nitrogen compounds such as melamine and the like. However, the flame retardant is not restricted thereto.
The releasing agent used in the present invention can be exemplified by higher fatty acid esters such as carnauba, montanic acid ester and the like; higher fatty acids such as stearic acid, montanic acid and the like; higher fatty acid metal salts such as zinc stearate, calcium montanate and the like; higher fatty acid amides such as N-stearylstearamide, ethylenebisstearamide, m-xylylenebisstearamide and the like; and polyolefin compounds such as polyethylene, oxidized polyethylene and the like. The releasing agent is not restricted thereto.
The ion-capturing agent used in the present invention is a compound which can capture a cation (e.g. sodium ion or potassium ion) or an anion (e.g. chlorine ion or bromine ion) and which is added for prevention of corrosion of a semiconductor element. It can be exemplified by hydrotalcites, bismuth oxides and antimony pentoxide, but is not restricted thereto.
The coloring agent used in the present invention can be exemplified by carbon black and organic dyes and pigments such as azo compound, phthalocyanine compound and the like.
The stress-reducing agent used in the present invention is a low-elastic substance used in an epoxy resin composition to reduce the stress generated during molding of the composition or the stress generated during heating and cooling of the cured material of the composition. It can be exemplified by organic rubber components such as polybutadiene, acrylonitrile and the like, and silicone rubber components such as polydimethylsiloxane and the like; however, is not restricted thereto.
The main components used in the epoxy resin molding material of the present invention, such as epoxy resin, phenolic resin, inorganic filler and the like are premixed and then ground by a grinder, whereby these components of different nature are dispersed homogeneously owing to the effects of fine grinding and homogenization. The components such as flame retardant, releasing agent, ion-capturing agent, coloring agent, stress-reducing agent and the like are ordinarily used in the epoxy resin molding material composition each in a small amount of 5% by weight or less; however, these small amount components are dispersed homogeneously as well in the epoxy resin molding material composition because they are premixed and then ground by a grinder and, thereby, finely ground and homogenized.
The raw materials of epoxy resin molding material composition for semiconductor encapsulation, i.e. an epoxy resin, a phenolic resin, an inorganic filler, a flame retardant, a releasing agent, an ion-capturing agent, a coloring agent and a stress-reducing agent are premixed and then ground, whereby the epoxy resin, the phenolic resin, the agglomerates of raw materials, and the agglomerates generated in premixing are finely ground. As a result, a ground material (a powder) can be obtained which has such a particle size distribution that the amount of particles having particle diameters of 250 xcexcm or more is 10% by weight or less, the amount of particles having particle diameters of 150 xcexcm to less than 250 xcexcm is 15% by weight or less, and the amount of particles having particle diameters of less than 150 xcexcm is 75% by weight or more, and the acetone-insoluble portion of which comprises particles having particle diameters of 212 xcexcm or more in an amount of 0.5% by weight or less.
When in the particle size distribution, the amount of particles having particle diameters of 250 xcexcm or more is more than 10% by weight, the amount of particles having particle diameters of 150 xcexcm to less than 250 xcexcm is more than 15% by weight, and the amount of particles having particle diameters of less than 150 xcexcm is less than 75% by weight and when the acetone-insoluble portion of the powder comprises particles having particle diameters of 212 xcexcm or more in an amount of more than 0.5% by weight, no uniform dispersion is attained in melt kneading and, when the resulting molding material is used for encapsulation of semiconductor elements, the semiconductor device obtained has defects owing to the voids present in the molding material.
The particle size distribution of ground material was determined by using two kinds of sieves having a 250-xcexcm mesh and a 150-xcexcm mesh, a sample amount of 6 g/each time, and a powder tester produced by Hosokawa Micron K. K. (amplitude=1 mm, frequency=3,000 VPM, time=60 seconds).
The acetone insoluble portion of ground material was determined by placing 200 cc of acetone of purity of 99.5% or higher and 100 g of a ground material in a vessel, dissolving the ground material in the acetone at ordinary temperature using a vibrator (a shaker produced by Yamato K. K., frequency=3 Hz, vibration time=20 minutes), then passing the vessel content through a sieve having a mesh of 212 xcexcm, drying the insoluble portion remaining on the sieve and measuring its weight, and calculating the weight ratio of the insoluble portion.
In the premixing of the present invention, a composition consisting of given amounts of raw materials is uniformly mixed in a Henschel mixer or the like. Then, the premix is finely ground and homogenized by a grinder.
The grinder has no particular restriction as to the kind as long as it can produce a desired particle size distribution. There are preferably used a vibration ball mill, a closed multi-stage shear extruder, a continuous rotary ball mill, a batchwise rotary ball mill, a corundum mill, a jet mill, a roller mill, etc. A combination thereof may be used. A grinder with a cooling mechanism is preferred to prevent the resin from being melted or softened in the grinding.
The hot kneader used in the melt kneading of the present invention has no particular restriction as to the kind. There can be used a single-screw kneader including a co-kneader, a twin-screw kneader, a hot roll, a continuous kneader, a Banbury mixer, etc.
In encapsulating semiconductor elements with the epoxy resin molding material of the present invention to produce a semiconductor device, molding such as transfer molding, compression molding, injection molding or the like can be used for curing and molding.
The present invention is described specifically below by showing Examples and Comparative Examples. However, the present invention is in no way restricted to the following Examples. The following two kinds of basic compounding recipes were used.
1. Evaluation Methods of Ground Material
Acetone Insoluble Portion
In a vessel were placed 200 cc of acetone having a purity of 99.5% or more and 100 g of a ground material, and dissolution was allowed to take place at ordinary temperature using a vibrator (a shaker produced by Yamato K. K., frequency=3 Hz, vibration time=20 minutes). Then, the mixture in the vessel was passed through a sieve having a mesh of 212 xcexcm; the insoluble portion remaining on the sieve was dried and then weighed; then, the weight ratio of the insoluble portion in acetone was determined.
Particle Size Distribution
Particle size distribution was determined using a tester (a powder tester produced by Hosokawa Micron K. K., amplitude=1 mm, frequency=3,000 VPM, time=60 seconds, mesh of sieve=two kinds of 250 xcexcm and 150 xcexcm, sample quantity=6 g/each time).
A sample (produced by subjecting the ground material to compression molding at room temperature at 100 kg/hr for 60 seconds, curing the molded material at 100xc2x0 C. for 48 hours, encapsulating the cured material with an epoxy resin, polishing the resulting material, and vapor-depositing carbon on the polished material) was determined for the standard deviation of the distribution of silica strength by use an analyzer (an electronic probe microanalyzer made by Nihon Denshi K. K.), and the standard deviation was taken as a yardstick of the degree of dispersion of compounded components. Therefore, a larger value indicates that the dispersion of components is less uniform.
2. Evaluation Methods of Epoxy Resin Molding Material
Number of Voids
A semiconductor package 160 p QFP (body size=28 mmxc3x9728 mm, package thickness=3.6 mm, IC chip size=15 mmxc3x9715 mm) was produced by encapsulation. The number of voids having major axis lengths of 0.1 mm or more, remaining in the semiconductor package was observed using an ultrasonic flaw detector, and the number of voids per package was counted. The conditions of transfer molding (encapsulation), used for production of the semiconductor package were as follows: die temperature=175xc2x0 C., injection pressure=100 kg/cm , injection time=15 seconds, holding time=120 seconds, and material-preheating temperature=80xc2x0 C.
Flowability
The epoxy resin molding material for semiconductor encapsulation was measured for spiral flow, using a transfer molding machine provided with a die for spiral flow measurement, based on EMMI-I-66. The conditions of transfer molding were as follows: die temperature=175xc2x0 C., injection pressure=70 kg/cm2, and holding time for curing=120 seconds.
Degree of Dispersion of Composition Components
A sample (produced by subjecting the epoxy resin molding material for semiconductor encapsulation after melt kneading, to compression molding at 170xc2x0 C. at 30 kg/hr for 120 seconds, encapsulating the molded material with an epoxy resin, polishing the resulting material, and vapor-depositing carbon on the polished material) was determined for the standard deviation of the distribution of silica strength by use of an analyzer (an electronic probe microanalyzer made by Nihon Denshi K. K.), and the standard deviation was taken as a yardstick of the degree of dispersion of compounded components.

Method of producing epoxy for molding semiconductor device, molding material, and semiconductor device


A holding tool for fixing bearings contains: a fixer, a rotary bar, and a plurality of positioning paws. The fixer includes a threaded hole and plural slots, one end of an inner wall of each slot communicates with the threaded hole, and each positioning paw is mounted on each slot. The fixer also includes a plurality of springs, each being fixed on each slot and each positioning paw has a stepped abutting rib and a tilted guiding face. The rotary bar includes a screwing section for screwing with the threaded hole, and the rotary bar also includes a conical contacting segment formed on a first end thereof and inserting through the threaded hole, wherein the contacting segment abuts against the tilted guiding face, after the rotary bar is screwed, such that each positioning paw is pushed by the contacting segment to expand outwardly.

A conventional bearing is hit to push the bearing into a machine or a workpiece, but such a fixing manner exerts a hitting force on the bearing unevenly.
TW Patent No. 1294813 disclosed a conventional holding tool for fixing bearings containing a rotary bar, and the rotary bar includes a connecting shaft extending outwardly from one end thereof, wherein the connecting shaft has a coupling orifice defined thereon. The conventional holding tool also contains at least one pressing block of various diameters which is fitted with the rotary bar, wherein each pressing block has a through hole defined on a central position thereof, a first contacting portion, a first forcing rim, a second contacting portion, and a second forcing rim. The conventional holding tool further contains a connector for connecting with the rotary bar. Thereby, the first contacting portion, the first forcing rim, the second contacting portion, and the second forcing rim of each pressing block abut against an inner wall and a top end of the bearing to balance a hitting force on the bearing, such that the bearing is fixed in the coupling orifice of the connecting shaft. Moreover, the at least one pressing block has different diameters to match with bearings of various sizes.
Nevertheless, a specific diameter of each pressing block cooperates with a bearing of a same diameter as that of each pressing block, thus fixing the bearings of various sizes troublesomely as applying the at least one pressing block of different diameters.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.


A planter's caddy that can be rotated and moved to different locations by way of five casters having dual wheels. The casters are mounted on an underside of the caddy which consists and is constructed as one unit. The unit has a circular top surface that is slanting downwardly toward its periphery. The top surface also has a multiple of upstanding ribs thereon. Each of the ribs has a top edge. All of the top edges form a planar surface that is oriented in a horizontal plane relative to the slanting top surface. The upstanding ribs are radiating outwardly from a center of the top surface toward a periphery of the top surface. At the periphery there is downwardly depending skirt.

There are a large number of wheeled plant pots that can be moved from one location to another.
U.S. Pat. No. 1,859,352 discloses a plant support that is rotating on a stationary base but cannot be wheeled to different locations. The plant support operates on the wheel principle of a "Lazy Susan"
U.S. Pat. No. 3,528,676 illustrates a movable container for flower pots which can be wheeled to different locations. The flower pot is disposed on top of ribs 11 that provide a ventilation area under the pot and to collect water therein.
U.S. Pat. No. 5,094,031 shows a wheeled plant pot that can be moved to different locations by way of casters attached to a bottom of the caddie. The flower pot is merely supported by an upper surface of the dolly or caddy.
U.S. Pat. No. 5,321,909 discloses a plant pot support for protecting a substrate, that is, a floor on which the plant is to placed. There are a multiple of radiant ribs, among others, to form a space between a bottom of the container and the substrate.
U.S. Pat. No. 5,819,469 shows a support plate for flower pots in which water is stored and hidden between an upper plate element and a lower plate element. The plant support has casters thereon so that the caddy can be moved to different locations.
U.S. Pat. No. 6,128,854 illustrates a potted plant turntable that can be programmed to turn the turntable at various time intervals so that the plant can evenly be disposed to sunshine.
U.S. Pat. No. 6,128,853 discloses a ball wheeled planter consisting of a deep container to collect water therein.
U.S. Pat. No. 6,655,084 shows a planter caddy including a frame having a support surface. The frame has caster wheels thereon. A plastic tray includes four recessed pockets. The plastic tray is supported on the support surface of the frame and receives a potted plant thereon.


The invention provides a composition comprising methylphosphonic acid or a salt thereof for human consumption. The invention also provides a method for treating aging and/or improving health in a human. Methods of the invention involve providing or administering methylphosphonic acid or a salt thereof to a human in need thereof for consumption. The invention provides nutritional and pharmaceutical compositions and articles containing such compositions including, for example, a nutritional supplement, a beverage, a food substance, a prepackaged food or meal, or a nutraceutical, as well as a pharmaceutical.

It has been reported that physical decline associated with aging in humans occurs as early as the third decade of life. Body functions are believed to peak before age 30, which is then followed by a gradual and continuous decline. Besdine, R. W., Changes in the Body with Aging, MERCK MANUALS, Merck Sharp & Dohme Corp, 2018, available at www.merckmanuals.com/home/older-people%E2%80%99s-health-issues/the-aging-body/changes-in-the-body-with-aging (last visited Jun. 20, 2018).
Bone density in men and women, for example, begins to diminish from about age 30 and accelerates in women after menopause. Villa-Forte, Effects of Aging on the Musculoskeletal System, MERCK MANUALS, Merck Sharp & Dohme Corp, 2018, available at www.merckmanuals.com/home/bone,-joint,-and-muscle-disorders/biology-of-the-musculoskeletal-system/effects-of-aging-on-the-musculoskeletal-system (last visited Jun. 20, 2018). The decrease in bone density often leads to development of osteoporosis as the individual ages. The decrease in bone density is also accompanied by a similar and gradual loss of muscle mass and strength, which often leads to arthritis. See Villa-Forte.
Age-related loss of function occurs at the cellular level, as well as the level of the organs and body systems and affects not only the bones and muscles, but also the joints, body fat, the eyes, the ears, the mouth and nose, the skin, the brain and nervous system, the heart and blood vessels, the muscles involved in breathing, the lungs, the digestive system, the kidney and urinary tract, the reproductive system, the endocrine system, blood, and the immune system. See Besdine.
Thus, the decline in body functions has far reaching effects on individual health, sense of well-being, and quality of life.

This patent is subject to a terminal disclaimer.

Compositions and methods for treating aging and/or improving human health


A test board circuit for testing integrated circuit modules under stress conditions, such as temperature, humidity, and bias. The integrated circuit module under test is plugged into a test socket which is part of the test board circuit. Without protection electrical shorting between test socket contacts, either from improper plugging of the module under test or from the formation of conductive deposits on the socket contacts, causes erroneous results and can damage devices in the integrated circuit module under test. The test board circuit protects the devices in the integrated circuit module under test from damage due to shorting between test socket contacts and provides a voltage signal which can be used to detect when a short has occurred.

(1) Field of the Invention
This invention relates to stress testing of integrated circuit modules and more particularly to detecting test board malfunction and to protecting devices under test from damage due to test board malfunction.
(2) Description of the Related Art
U.S. Pat. No. 5,319,515 to Pryor et al. describes a circuit protection circuit which uses the base or gate of a switching transistor to sense overcurrents. When an overcurrent is experienced, a control transistor switches on causing the switching transistor to turn off. A shunt switching circuit to shunt the overcurrent across the load may also be used.
U.S. Pat. No. 4,597,025 to Rutchik et al. describes an alternating current, overload current sensing, remote power controller.
U.S. Pat. No. 5,457,391 to Shimizu et al. describes a load short state detection circuit.
The invention of this Patent Application uses a resistor network to detect shorting between adjacent contacts of a test socket used in stress testing of integrated circuit modules. The resistor network forms a protection circuit which protects the modules under test as well as indicates when a malfunction has occurred.

Test board circuit for detecting tester malfunction and protecting devices under test

Taiwan Semiconductor Manufacturing Company, Ltd.


In a two way cable system that includes a controller and a plurality of user terminals, a method of granting rights for upstream data transmission from the user terminals includes processing contention requests to generate contention grants and maintaining a list of connections, each connection having specified therefor a predetermined bit rate. The controller sends a downstream data stream to the user terminals and receives an upstream data stream from the user terminals. The downstream data stream includes a plurality of grant fields, and the upstream data stream includes upstream data slots and upstream control slots. The method further includes scheduling preemptive grants for upstream data slots using selected fields of the plurality of grant fields so as to provide preemptive grants for upstream data transport at a bit rate specified for each connection, sending to the user terminals a data transmission grant in a grant field of the plurality of grant fields for which a preemptive grant is scheduled, and sending to the user terminals a data transmission grant in a grant field of the plurality of grant fields in which a contention grant is pending and no preemptive grant is scheduled.

1. Field of the Invention
The present invention relates to a mechanism to provide constant bit rate upstream data transport in a two way communication system (e.g., a cable TV system) that has a known contention based upstream data transport mechanism. In particular, the invention relates to a mechanism to provide the constant bit rate upstream data transport, such as for a telephone voice channel, in a way that is compatible with known contention based available bit rate upstream data transport mechanisms so that jitter requirements of the constant bit rate transmission are fulfilled while not adversely effecting the latency of the available bit rate upstream data transport.
2. Description of Related Art
The upstream channel of a cable system is expected to carry a variety of services ranging from CBR (Constant Bit Rate) to ABR (Available Bit Rate) as defined by the ATM Forum (Asynchronous Transfer Mode Forum). These two services have unique sets of quality of service requirements such as jitter. For the CBR services, bounded jitter is required but not for the ABR services. ABR performance is measured on the system response time where the access delay plays a key role. CBR and ABR data are also different on the prospects of the traffic patterns. CBR sources produce data in a constant rate fashion while the ABR sources are usually in the burst mode. In the shared upstream channel of the cable television (CATV) environment, the services can not be optimized by a single Medium Access Control (MAC) protocol due to the above differences. The contention based Medium Access Control algorithm has been shown as an appropriate protocol for the local area network (LAN) traffic to provide instant access but it can not provide a guaranteed access environment for CBR sources to achieve bounded jitter.
One family of the contention algorithms, Distributed Queue Random Access Protocol (DQRAP), which uses a separate field (other than the data field) for resolving collisions while the user data transmission is taking place at the same time has been proposed to optimize the system throughput for ABR traffic. DQRAP has shown 85% of utilization with reasonable average access delay. It falls short of providing guaranteed access in order to support CBR services.
What is needed is a priority preempt mechanism to support guaranteed access in a contention based media access protocol in order to optimize these two services in the same system.
Historically, guaranteed access is provided via a TDMA (time division multiple access) arrangement. However, the TDMA approach can only provide services of an integer multiplier of a base rate. For example, these services are possible, 16 Kbps, 32 Kbps, 48 Kbps, etc., if the base rate is 16 kbps. Any request between two layers results in bandwidth waste.
TDMA is based on a cyclic framing structure. Access to the media is usually restricted until the start of the next cycle. It can be a long time if the frame is large or the transmission rate is low.
Another scheme often employed for guaranteed performance is when a station is polled periodically and the station can indicate if there is information to send. Performance of the source data can be guaranteed but at a significant waste of bandwidth because of the need to send the poll to a station and the bandwidth wasted when the station has nothing to send.
A media access control mechanism such as DQRAP uses a separated fields called Control Mini-Slots (CMS) to resolve collided transmissions while actual data transmission occurs at the data slot. Several CMSs associated with a data slot form the basic transmission unit. A station with packets ready for transmission choose one of the CMSs randomly to gain the right to transmit. Those stations that have already obtained the transmission rights are scheduled in a virtual queue called TQ (each station knows the total number of waiting members and its position among them). The requesting stations are informed of the success of the access requests by feedback sent by the Central Controller on the downstream channel with what is called contention grants. DQRAP has shown good performance in terms of Utilization vs. Access Delays. It is difficult and expensive to implement a priority scheme during the contention phase without priority protection. DQRAP can not guarantee bounded jitter which is required in order to support CBR services.
XDQRAP (Extended Distributed Queue Random Access Protocol) is a Medium Access Control (MAC) protocol designed to satisfy a wide range of performances required by the services that the IEEE 802.14 network is expected to provide. It is a contention-based protocol that provides LAN type of traffic an instant access environment. With a central feedback mechanism that is a natural result of the tree-and-branch network topology, it seamlessly marries a reservation scheme to offer deterministic access for the Constant Bit Rate (CBR) services. The MAC was presented in the paper A proposal to Use XDQRAP for the IEEE 802.14 (IEEE 802.14/95-068) at Section 5 entitled Media Access Control incorporated herein by reference. Simulation results of the basic XDQRAP were presented in the paper Simulation of the Performance of XDQRAP under a Range of Conditions (IEEE 802.14/95-049) at Sections 2 and 3, pages 3 and 4 incorporated herein by reference.
In the XDQRAP model, the channel time is partitioned into a sequence of time slots. Each unit consists of a data field where the actual data transmissions takes place and a control field used for requesting data slots. The request field consists of two areas called Control Mini Slots (CMS). Stations with data to transmit follow a set of rules to put the transmission requests in one of the control mini slots. The contention resolution algorithm is a tree based approach since there are potentially more than one request in the same control mini slot. By taking advantage of the central feedback, XDQRAP keeps the newly arrived packets out of contention to achieve fast-coverage resolution cycle.
The status of the control mini-slots and the data slots are constantly monitored at the headend. Based on the information, the global queuing information is fed back to the network via the common downstream channel. An individual station, therefore, adjusts its local state-machine accordingly. The contention winning stations position themselves in the global transmission sequence. Stations that lose in the contention retry at the next scheduled time.
Voice and some video conferencing data streams require that data arrives at the receiver within a narrow window of time (i.e., minimum jitter). Having contention for data slots is thus not a good mechanism to use for Constant Bit Rate (CBR) data streams. What is needed is a mechanism whereby a station can be guaranteed to send data at fixed intervals without having to use the control mini-slots to request data slots.

Providing constant bit rate upstream data transport in a two way cable system by scheduling preemptive grants for upstream data slots using selected fields of a plurality of grant fields


A display section displays a speedometer having a substantially circular shape on an outer circumference of which a speed scale is provided. Then, that point on the outer circumference of the speedometer which indicates a speed at a moment is calculated. Further a speed that is attained at a given time period (e.g. 0.5 second) after the moment if the speed is increased at an acceleration at the moment is calculated. An arc-shaped pointer is displayed, the arc-shaped pointer passing (i) the calculated point of the speed scale, (ii) a middle point between the calculated point of the speed scale and a center of the speedometer, and (iii) the center of the speedometer. With this arrangement, a display device displaying the speedometer allows a driver to easily recognize the speed and an amount of a change therein (i.e. acceleration).

1. Field of the Invention
The present invention relates to a display device for displaying a value of a physical quantity and an extent of a change in the physical quantity, a vehicle provided with the display device, a method for displaying, a program for displaying, and a recording medium of the same.
2. Description of the Related Art
In general, a vehicle (transportation means) such as automobiles is provided with measuring sections for measuring a speed, a number of engine revolution (revolution speed), and the like, and meters such as a meter for speed (speedometer), a revolution speeder (tachometer), and the like.
Referring to reading of the meters, a driver can grasp a driving speed and the number of engine revolution (revolution speed) at a moment when the driver referred to the meters. This enables the driver to drive more appropriately.
Moreover, for example, Japanese Utility Model Publication, Jitsukaihei, 2-124559 (published on Oct. 15, 1990) discloses an acceleration display device, provided on a vehicle, so as to display acceleration measured by an acceleration sensor. The acceleration display device displays the acceleration in such a manner that an indicator extended in a radial direction from a center corresponds to an extent of the acceleration, where the center is an original point of coordinates.
A speedometer and tachometer, however, indicate a speed and revolution speed at the moment of reading: the speedometer and tachometer do not indicate extents of changes in the speed and the revolution speed. Therefore, the driver can grasp the extents of the changes, e.g., by feeling a change of scenery around a vehicle, a change in sound of engine, or other changes.
Moreover, in the art disclosed in Japanese Utility Model Publication No. 2-124559, the vehicle provided with the acceleration display device is provided with an acceleration meter (a display section for displaying the acceleration) in addition to the speedometer and tachometer.
This results in an increase in a number of the meters to be referred by the driver, thereby increasing a number of directions the driver looks to or a number of occasions the driver looks at any of the meters. This puts more burden on the driver and makes it difficult for the driver to recognize reading of each meter.

Display device, vehicle, method for displaying, program for displaying and recording medium of same


A wide variety of integrated circuit applications exist for boosted nodes, wherein a voltage is boosted above the power supply level. Typical uses include clock driver circuits in microprocessors, row lines in dynamic and static memory chips, and substrate bias generators. However, in the prior art, only n-channel transistors have been usable to boost nodes above the positive power supply level, to prevent forward-biasing the drain-to-substrate diode. The present invention allows a p-channel device source/drain region to be connected to a boosted node. This is accomplished by also boosting the voltage of the n-tub in which the device is formed, thereby allowing the p+ source/drain regions to be boosted without latch-up or other problems. Similarly, n-channel devices may be connected to nodes boosted more negative than V.sub.SS.

1. Field of the Invention
The present invention relates to an integrated circuit having a voltage boosted above a given power supply level.
2. Description of the Prior Art
In the design of integrated circuits, it is frequently desirable to boost the voltage on a circuit node to a value in excess of a power supply voltage. For example, in the case of 5 volt integrated circuits, a boosted level of about 6 to 7 volts is often generated. The boosted level is applied to the gates of transistors that serve as clock drivers, or row drivers in the case of static or dynamic memory chips. In this manner, the threshold voltage drop of the transistor, typically in the range of from 0.5 to 2 volts, is overcome by the boosted voltage, and a more robust clock or row voltage is obtained for improved circuit operation. In still another application, a substrate voltage is boosted by means of a so-called back gate bias generator. For example, a negative boost voltage has been used to bias a substrate to a voltage below V.sub.SS, typically to increase transistor thresholds and reduce circuit capacitance.
In prior-art boost circuits implemented in CMOS technology, an n-channel transistor was used for boosting positive voltages (above V.sub.DD), whereas a p-channel transistor was used for boosting negative voltages (below V.sub.SS). One example of n-channel boost circuitry used in a dynamic memory is shown in U.S. Pat. No. 4,649,523 coassigned herewith, with still other circuit types being possible. This use of n-channel devices connected to a boosted positive node prevents forward-biasing the junction between the source or drain region of the transistor and the semiconductor region in which it was formed. That is, a positive voltage on an n-type drain region reverse-biases the junction between the drain and the underlying p-type region. Otherwise, any forward-biased conduction between the drain and the underlying region could cause undesirable effects in the operation of the integrated circuit. For example, the conduction would load down the boost circuitry, wasting power. Also, the conduction could inject undesirable carriers into the underlying region, which could lead to latch-up in CMOS circuits. However, it is apparent that this restriction limits design freedom to the use of only one conductivity type source/drain region connected to a given type of boosted node.
The underlying region in which the source/drain regions are formed is often, but not necessarily, a "tub" (alternatively referred to as a "well") region that is doped separately than the rest of the substrate. Twin-tub CMOS processes are known in the art, wherein both the n-channel and p-channel devices are formed in tubs, being p-tubs and n-tubs respectively. Alternatively, single-tub CMOS processes are known, wherein only one type of device is formed in the tub, and the other type is formed in the surrounding substrate region. More recently, triple-tub processes have been used, whereby tubs having two different doping levels are used for one device type (typically the n-channel transistors), and another tub for the other device type (typically the p-channel transistors). In the prior art, an n-tub is usually electrically connected to the positive power supply voltage (V.sub.DD), whereas a p-tub is usually connected to the negative power supply voltage (V.sub.SS). Therefore, any voltage on a source/drain region of a p-channel device that is more than one diode voltage drop (about 0.6 volts) above V.sub.DD causes conduction to the n-tub. Similarly, any voltage on a source/drain region of an n-channel device more than one diode voltage drop below V.sub.SS causes conduction to the p-tub.

Integrated circuit having a boosted node


Disclosed is volumetric display arrangement for representing content of an image at different focal distances in a view of real-world environment. The volumetric display arrangement includes at least one image projection unit operable to project multiple depth planes of the image, at least one electro-optical unit comprising two or more optical diffuser elements arranged parallel to each other, the at least one electro-optical unit being positioned to receive the projected multiple depth planes of the image thereon and configured to independently display one of the projected multiple depth planes of the image at one of the two or more optical diffuser elements at a given instant of time, and an optical combiner positioned with respect to the at least one electro-optical unit to combine the view of real-world environment with the independently displayed multiple depth planes of the image in the at least one electro-optical unit.

With the advancements in technology, three-dimensional (3D) content visualization has gained popularity in the recent years as information, data, objects, models and so forth visualized in three-dimensional (3D) format are effectively perceived and retained by the human brain. Therefore, three-dimensional imagery is used in the fields of education (for example, to show three-dimensional models to students at schools and colleges), civil engineering, air traffic control management (for example, to model airspace surrounding an airport), architecture, medicine, research and science, military and defence (for example, to depict topographical models of battlefields), and the like.
Several techniques have been developed to present three-dimensional (3D) imagery. Typically, two-dimensional displays such as Liquid Crystal Display (LCDs), diode-based displays and the like are employed to present graphical content such as images, videos and so forth in a three-dimensional (3D) format. However, such techniques of representing three-dimensional images on two-dimensional displays fail to present physical depth cues which are essential for a realistic representation of three-dimensional images and thus limiting the perception and spatial awareness of viewers viewing content on such displays. Furthermore, to realistically represent three-dimensional objects and scenes, modern three-dimensional display technologies such as stereoscopic displays, including head-mounted displays, helmet-mounted displays and the like are employed. However, such techniques are also associated with multiple problems. Currently, techniques employing stereoscopic displays utilize conventional 2D imaging solutions allowing presenting only psychological depth cues and limited physical depth cues to imitate depth and thus cannot correctly drive accommodation and convergence. Thus, these depth-sensing mechanisms, which naturally are linked, become decoupled, which can cause unpleasant sensations to the viewer and thus limit the viewing time, and can also cause human errors based on inadequate decision making due to incorrectly or imprecisely perceived 3D information.
Therefore, in the light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks associated with conventional techniques employed for presenting three-dimensional imagery including representation of not just psychological depth cues but also correct physical depth cues.

Volumetric display arrangement and a method for representing content of an image


A method and apparatus adapted to cool a circuit board in a rack-mountable housing includes transferring heat from a heat source on the board to a primary heat storage medium positioned at an edge of the board or within a rack-mountable housing using at least one heat pipe, transferring heat from the primary heat storage medium to a secondary heat storage medium positioned in the rack-mountable housing through contacting surfaces of the primary and secondary heat storage mediums, transferring heat from the secondary heat storage medium to a heat exchanger, which may be positioned within the rack-mountable housing, using at least one heat pipe, and cooling the heat exchanger. A method and apparatus adapted to cool a printed circuit board includes transferring heat from a heat source on the board to a heat exchanger positioned in the rack-mountable housing using at least one heat pipe, and cooling the heat exchanger.

1. Field of the Invention
The present invention relates to methods of cooling printed circuit boards in an enclosure, and more particularly relates to cooling blade servers in a rack-mounted enclosure using heat transfer through surface contact and forced air.
2. Description of the Related Art
A blade server is a single circuit board populated with components, such as processors, memory, and network connections that are usually found on multiple boards. Blade servers are designed to slide into enclosures. Blade servers are more cost-efficient, smaller, and consume less power than traditional rack-based servers.
Current blade server designers face many design challenges. One of the key challenges is minimizing overall design costs. Another is keeping blade server electronic components cool and within their operating specifications. Yet another is maintaining accessibility (easy removal and reattachment) of the individual blade server from a housing unit. A successful blade server design must address these critical issues, that is, heat, accessibility, and costs.
A popular cost-saving blade server design approach utilizes Commercial Off-the-Shelf (COTS) products, such as the industry standard MicroATX, ATX, BTX, EATX form-factor motherboards. Unfortunately, the COTS design approach has many inherent design deficiencies. In reality, most COTS motherboards are not designed to fit into slim-style, height-restricted blade enclosures. Rather, they are designed for spacious computer enclosures with plenty of headroom for the component cooling devices. In addition, utilizing COTS motherboards in blade server designs hinders blade accessibility due to non-uniform I/O connector height. Nevertheless, COTS motherboards are readily available and can be purchased cheaply on the market. The cost saving is a very compelling reason for blade designers to utilize COTS motherboards in their blade server designs.

Method and apparatus for cooling a blade server


A method and system for injecting a pulsed radio frequency signal into a fluid-containing system in order to create and propagate an electromagnetic field throughout the fluid-containing system. The electromagnetic field may be used to prevent the formation and build-up of scale in the fluid-containing system and/or to prevent the proliferation of bacteria within the fluid-containing system. The method and system may also be used to inject a pulsed radio frequency signal at a number of points in a fluid-containing system, or to inject a pulsed radio frequency signal to a number of independent fluid-containing systems.

The present invention generally relates to a method and a system for treating a fluid-containing system in order to resist the formation and build-up of scale deposits.
Scale is the build-up of mineral salt deposits on internal surfaces of fluid-containing equipment, such as pipes. In particular, calcium and magnesium, which are commonly contained in water, are heavily involved in the formation of scale.
Scale is formed when mineral ions present in a fluid reach conditions at which they change phases from liquid to solid. Ions present in a fluid require energy to begin the process of forming a solid. Formation of a solid on an existing surface, such as the internal surface of a pipe, requires less energy. Accordingly, it is on the surfaces of pipes and other equipment with which the fluid comes into contact that mineral ions most frequently undergo their phase change to solids. The solids form on, and adhere to, these surfaces, creating scale.
When scale builds up in a pipe or other conduit, it alters the flow of the fluid. By decreasing the volume of fluid that flows through a pipe, scale requires pumps and other industrial equipment to use more energy in order to transport the same volume of fluid. Scale may also increase pressure in a pipe, which can cause leaks and breakages. Because heat provides energy to fuel the ions' phase change to solid, scale build-up on heated equipment, such as steam boilers and heat exchangers, is especially problematic. Scale formation on these devices may lead to reduced heat transmission, higher fuel usage, and even local overheating and failure. The build-up of scale also may have a number of indirect effects, such as providing a location for bacteria to build up in the fluid-containing system and interacting with soap to prevent cleaning of the fluid-containing system.
A number of methods to resist scale formation and build-up are known in the art. For instance, chemical solutions have been introduced into fluid-containing systems. The use of chemical solutions, however, is undesirable both because it requires constant replenishment and because it contaminates the fluid. Accordingly, a number of physical water treatment methods have been identified. One physical water treatment method involves positioning electrodes in the fluid-containing system. However, as the electrodes erode, they lose their effectiveness and need to be replaced. Another method involves the positioning of magnets in direct contact with the fluid. However, the magnets collect magnetic debris which, itself, can obstruct the pipe.
Another method of physical water treatment involves the creation of an electromagnetic field, either exteriorly and/or interiorly of a piping system. An electromagnetic signal prevents the formation and build-up of scale by providing energy to the ions, causing them to undergo a phase shift to a solid state within the fluid. Accordingly, the ions stick to each other, rather than to the internal surfaces of pipes and other equipment. As such, they continue to flow through the fluid-containing system and do not build up in the fluid-containing system.
This method of treatment is disclosed, for example, in U.S. Pat. No. 5,514,283. There, an electromagnetic field is created in a fluid-containing system in different ways. One method involves a primary winding of electrical wire, to which an energizing means is connected, and a secondary winding of electrical wire. The primary and secondary windings are separated by a ferrite core. The secondary winding has a pair of terminals, which are placed in electrical contact with a fluid-containing conduit at axially spaced-apart contact zones. A conductive path extends along the conduit between the two contact zones, creating a low voltage, high current signal between the terminals. The high current generates an electromagnetic field that propagates along the conduit in both directions from the contact zones. In another method, a ferrite core is coiled co-axially or spirally around the conduit in a manner so as to extend through a primary winding of electrical wire. In this method, the electromagnetic field is achieved by making the pipe itself and/or the fluid therein serve as the secondary winding.
In many applications of physical water treatment involving an electromagnetic field, it is necessary to have the electromagnetic field freely propagate throughout the fluid-containing system. However, the propagation of an electromagnetic field across large distances in a fluid-containing system has often been difficult and/or impossible to achieve with known methods and devices. For instance, piping configurations in the fluid-containing system create hidden return paths which effectively force the electromagnetic field to a loop, leaving significant portions of the system untreated.

Method and system for injecting RF signal into a fluid-containing system


An RF jack and plug assembly provides 360.degree. of contact with a strong mechanical bond between the two parts. The jack has molded and stamped interrelated parts that predeterminedly position the parts for simple and accurate assembly. The construction provides positive electrical contact and long life for the contact elements with complete RF shielding.

The RF connector jack assembly which is the preferred embodiment of the present invention is a miniature device designed to allow a coaxial cable to interconnect from one printed circuit board to another or to an external device. This is accomplished by interconnecting the jack to a mating plug which mounts on a printed circuit board. An RF signal can then be transmitted from the board to another board via the coaxial cable. The RF connector jack sub-assembly consists of an outer housing/contact, a dielectric support, and an inner contact. This sub-assembly is then terminated to a coaxial cable to form the final connector jack assembly. An example of one such subassembly and corresponding plug assembly is illustrated in U.S. Pat. No. 5,078,621 issued Jan. 7, 1992 to Nishi Kawa et al.


Embodiments improve the ability of users of a social networking system to search for information that is likely to be relevant to them by learning and/or applying a search context associated with selector components used to search for objects of the social networking system. The search context is specific to the use of an individual selector and thus need not be as general as the context of an entire page or set of pages in which selectors can be embedded. The social networking system may learn the context of a selector by monitoring user selections from prior search results performed using the selector.

The present invention generally relates to the field of computer data storage and retrieval, and more specifically, to performing searches for objects within a social networking system.
Modern computing systems store vast amounts of data, and as a consequence it has become increasingly important to provide users with effective ways to locate information that is relevant to their interests. One area in which a large amount of information is involved is social networking. Social networking systems allow users to designate other users as friends (or otherwise connect to or form relationships with other users), contribute and interact with media items, use applications, join groups, list and confirm attendance at events, create pages, and perform other tasks that facilitate social interaction. Since each of these tasks may involve various data objects, social networking systems are good examples of the demand for systems that help users locate relevant information from within a large set of information tracked or otherwise used by the system.
Searches for information on a social networking system sometimes take place within a particular context. For example, users might specify some searches from within a data search area located on a page about restaurants. Although it might be helpful to customize a search to result in, or emphasize, objects particularly relevant to the context (e.g., restaurants), the search functionality currently available on social networking systems typically does not include a way to determine what the search context is, nor to take that search context into account when performing a search. This makes locating information of particular relevance to a given search more challenging.

Context-based object retrieval in a social networking system


A surface layer of an electrophotographic photosensitive member contains (α) a particular siloxane-modified resin, (β) a particular compound, and a charge transporting substance. (β) is at least one compound selected from the group consisting of hexanol, heptanol, cyclohexanol, benzyl alcohol, ethylene glycol, 1,4-butanediol, 1,5-pentanediol, diethylene glycol, diethylene glycol ethyl methyl ether, ethylene carbonate, propylene carbonate, nitrobenzene, pyrrolidone, N-methylpyrrolidone, methyl benzoate, ethyl benzoate, benzyl acetate, ethyl 3-ethoxypropionate, acetophenone, methyl salicylate, dimethyl phthalate, and sulfolane.

1. Field of the Invention
The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus.
2. Description of the Related Art
Electrophotographic photosensitive members for use in electrophotographic apparatuses often contain an organic photoconductive substance (a charge generating substance). While an electrophotographic apparatus forms images, electrical and mechanical external forces, such as those utilized in charging, exposure, development, transfer, and cleaning, are directly applied to an electrophotographic photosensitive member of the electrophotographic apparatus. Thus, the electrophotographic photosensitive member must be resistant to such electrical and mechanical external forces. The electrophotographic photosensitive member also should have a surface that can reduce friction (increase lubricity) against a contact member (such as a cleaning blade).
In order to increase lubricity, Japanese Patent Laid-Open No. 2008-195905 and No. 2006-328416 propose a method for introducing a particular siloxane-modified polycarbonate resin (having a siloxane structure) into a surface layer of an electrophotographic photosensitive member. Japanese Patent Laid-Open No. 2009-84556 proposes a method for introducing a particular siloxane-modified polyester resin into a surface layer.
As a result of investigations, however, the present inventors found that a siloxane material and a charge transporting substance in a surface layer of an electrophotographic photosensitive member tend to induce ghosts. More specifically, a portion of an output image irradiated with light during pre-rotation tends to have a high density (a positive ghost).
When a particular siloxane-modified polycarbonate resin or siloxane-modified polyester resin disclosed in Japanese Patent Laid-Open No. 2008-195905, No. 2006-328416, and No. 2009-84556 is used, there is room for improvement in reducing occurrence of ghost images during repeated use of an electrophotographic photosensitive member.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus


An output buffer has a series circuit connected between a first and a second power supply terminal, which circuit is formed by a first n-channel MOSFET whose gate receives a first output data control signal and a second n-channel MOSFET whose gate receives a second output data control signal. The output buffer further has a third N-channel MOSFET connected between a bonding pad and a common junction node defined by the first and second N-channel MOSFETs. The third N-channel MOSFET has a gate connected to the first power supply terminal so that it is controlled to be always in a conductive state. The output buffer is effectively increased or enhanced in its resistance against electrostatic breakdown.

1. Field of the Invention
The present invention relates to an output buffer in a semiconductor integrated circuit device, and more particularly to an output buffer in which resistance against electrostatic breakdown is enhanced or improved.
2. Description of the Related Art
A conventional output buffer of the kind to which the present invention relates is shown in FIG. 1A. The conventional output buffer has a series circuit connected between a power supply terminal V.sub.CC and a ground terminal V.sub.SS, which is formed by an n-channel MOS field effect transistor (hereinafter referred to as "MOSFET") M11 receiving at its gate a first output data control signal D11 and an n-channel MOSFET 712 receiving at its gate a second output data control signal D12. A common junction node X1 defined between these two n-channel MOSFETs M11 and M12 is connected to a bonding pad PAD which is connected with an output terminal of the semiconductor integrated circuit device.
Next, the operation of the above described output buffer will be explained.
When the first output data control signal D11 is at a high level and the second output data control signal D12 is at a low level, the n-channel MOSFET M11 turns to a conductive state and the n-channel MOSFET M12 turns to a non-conductive state, so that the data outputted by the n-channel MOSFET M11 becomes a high level. On the contrary, when the first output data control signal D11 is at a low level and the second output data control signal D12 is at a high level, the n-channel MOSFET M11 turns to its non-conductive state and the n-channel MOSFET M12 turns to its conductive state, so that the data outputted by the n-channel MOSFET M12 becomes a low level.
However, in semiconductor integrated circuit devices for which minitualization is being advanced, to prevent degradation by the hot carrier in the element, the devices are being formed with a lightly doped drain (LDD) structure. In other words, in this type of MOSFETs, as shown in FIG. 2, a gate electrode 203 is formed on a p-type semiconductor substrate 201 with a gate silicon dioxide layer 202 being disposed therebetween, and there are formed at both sides of the gate electrode 203 a drain region constituted by an n.sup.+ -diffusion layer 204 and an n.sup.- -diffusion layer 205, and a source region constituted by an n.sup.+ -diffusion layer 206 and an n.sup.- -diffusion layer 207.
The above mentioned conventional output buffer had a disadvantage in that, because it was made with the LDD structure MOSFETs, its resistance against electrostatic breakdown was insufficient.
In an LDD structure MOSFET as shown in FIG. 2, if a high voltage is applied to the drain thereof, avalanche breakdown occurs in the vicinity of the gate electrode of the drain electrode, that is, at the n.sup.- -diffusion layer 205, and holes are injected into the p-type semiconductor substrate 201. As a result, the potential of the semiconductor substrate 201 rises, the region between the source region (n.sup.+ -diffusion layer 206 and n.sup.- -diffusion layer 207) and the semiconductor substrate 201 becomes biased in the forward direction, and electrons are injected into the substrate 201 from the source region. As a result, the MOSFET operates in a state near negative-resistance and excessive current flows in the n.sup.- -diffusion layer 205 forming the drain region, and this drain region is destroyed by heat due to the high resistance value of this diffusion layer.
To cope with this, as shown in FIG. 1B, there is a method in which a resistor element R is connected between the junction node X1 of the MOSFETs M11, M12 and the bonding PAD to enhance the resistance against electrostatic breakdown, but to attain the required resistance against the electrostatic breakdown, a resistor having a high resistance value must be used, and in this case, the current drivability of the output buffer is reduced, and the lowering of the operation speed becomes a problem.

Output buffer having high resistance against electrostatic breakdown


A new computerized tracking system, IndeliTrak, that incorporates the state-of-the-art technologies including cell phones, GPS, Internet, and scanners to gather and distribute up-to-the-minute tracking data with little effort. As an example, a courier carries a mobile phone that is attached to a barcode scanner and programmed with IndeliTrak's tracking software. The mobile phone enables the courier to log in, retrieve his service schedule, verify each service location, log arrival/departure time, scan packages for pickup and delivery, and sign off. Scanned data are stored on the phone and transmitted to a customized IndeliTrak database. End users can track the packages via IndeliTrak's browser-based user interface almost instantaneously. IndeliTrak does not require unique package identifications (IDs) or barcodes. Acceptable IDs include radio frequency identification (RFID) tags, non-serialized barcodes, electronic product codes (EPCs), etc. The same ID code can be reused daily.

Computerized tracking systems are currently in use by many courier companies. For example, Comet Tracker from ActSoft, Inc. of Tampa, Fla. utilizes cellular phones equipped with the Global Positioning System (GPS) transceivers to track personnel movements. SmartTrax from Vertrax, Inc. of New Haven, Conn. utilizes vehicles equipped with the GPS transceivers to track vehicle movements. As a separate software package, Vertrax also offers SmartDrops for mapping, routing, and delivery planning.
A key difference between existing systems and the present invention, hereinafter referred to as IndeliTrak™, is that IndeliTrak provides a full courier solution and requires very few additional steps for tracking packages, taking particular advantages of the capabilities of today's wireless communications technologies, for example, cellular phones, GPS, wireless Internet connectivity, infrared (IR) code readers or laser barcode scanners, and radio frequency identification (RFID) tags.
IndeliTrak's proprietary software seamlessly incorporates these technologies to enable field personnel, e.g., a driver, to obtain and provide tracking data naturally with very little effort beyond what is needed for the actual delivery. For example, route stops are digitally made available in real time to the drivers. Automatic verification ensures the delivery of all planned packages. The pocket size and form factor of a phone-scanner mobile unit allows the driver to easily carry the unit while carrying packages. In an embodiment, a basic Indelitrak mobile unit is a GPS- and Internet-enabled mobile phone programmed with IndeliTrak proprietary software and attached with an IR barcode reader. The mobile unit enables its user to access, in real time, the IndeliTrak server over a wireless Internet connection.
As an example, a driver gathers data upon package pickup or delivery via the mobile unit. The gathered data are immediately stored on the phone and uploaded wirelessly over the Internet to the IndeliTrak server and stored in the IndeliTrak database. The IndeliTrak server has a browser-based user interface that promptly shows the uploaded data to courier customers and managers having access thereto.
A core technology of IndeliTrak is how packages are scanned into the system. Unlike conventional computerized tracking systems, IndeliTrak does not require fully unique package IDs or barcodes. The ability of IndeliTrak to eliminate this requirement while maintaining system integrity contributes to the robustness of IndeliTrak. Moreover, the same barcode can be reused daily. This is a resource-saving advantage as envelopes and/or bags can be recycled without replacing the barcode tag. The only limitation is that duplicate barcodes cannot be part of the same individual pickup or delivery. The IndeliTrak object-oriented based software accepts just about any and all IDs, whether unique or not, without any a priori knowledge or prior coordination. Acceptable IDs include, but not limited to, radio frequency identification (RFID) tags, barcodes generated by a customer, electronic product code (EPC) from the bottom of a tissue box, etc. In this way, IndeliTrak administrators and customers alike are able to find and track each transaction and individual packages without having to know the package IDs. The elimination of long unique ID strings concatenated from multiple data sources has the additional advantage of alleviating the low-bandwidth requirements of the mobile phones.
The IndeliTrak system is optimized for same-day, route-based deliveries. However, it is flexible and can be readily implemented to work in most any courier services. In practice, IndeliTrak drivers are happy to adopt the system because it makes their job much easier and more productive. The latter contributes to higher pay because they are able to deliver more packages in the same or shorter time frame. The overall system is characterized by its high efficiency, accuracy, responsiveness, flexibility, minimal learning curve, and labor-saving features.
Other objects and advantages of the present invention will become apparent to one skilled in the art upon reading and understanding the preferred embodiments described below with reference to the following drawings.


A procedure and frame structure for Wi-Fi sensing is described. An aspect of the disclosure provides a method of sensing. Such the method includes sending, by an initiating station (STA) to a plurality of responder STAs, a sensing request comprising a sensing announcement frame indicating identifiers (ID) of the plurality of responder STAs. Such a method further includes receiving, by the initiating STA from the plurality of responder STAs, one or more responses based on the sensing request. In some embodiments, the announcement frame further indicates resource unit assignments for receiving acknowledgements from the plurality of responder STAs. In some embodiments, the method further includes receiving, by the initiating STA from the plurality of responder STAs, the acknowledgements indicating a willingness to participate in the sensing procedure.

Channel state information (CSI) was introduced in 802.11n and 802.11ac in the context of multiple-input and multiple-output (MIMO).
CSI may reflect the wireless signal propagation characteristics for a link from a transmitter to a receiver at certain carrier frequencies. CSI measurements may include information when wireless signals transmit through surrounding objects and humans in time, frequency, and spatial domains. Accordingly, the use of CSI measurements for wireless sensing applications has been proposed. However, there is an ongoing need for a suitable frame structure for doing so. Further, format of CSI information, which may be used by legacy devices, may not be compatible with feedback information that may be required for sensing purposes. In addition, feedback information that may be received in 802.11n may have a format different from that of 802.11ac, which further limits processing such feedback information for sensing purposes.
Therefore, there is a need for a system and methods for a procedure and frame structure for Wi-Fi sensing that obviates or mitigates one or more limitations of the prior art.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.


The present invention relates to prognostic methods which are useful in medicine, particularly cancer chemotherapy. The object of the invention to provide a method for assessing GST-pi expression levels in fixed or fixed and paraffin embedded tissues and prognosticate the probable resistance or sensitivity of a patient's tumor to treatment with platinum-based therapies by examination of the amount of GST-pi mRNA in a patient's tumor cells and comparing it to a predetermined threshold expression level. More specifically, the invention provides to oligonucleotide primer pair GST-piand methods comprising their use for detecting levels of GST-pi mRNA.

Cancer arises when a normal cell undergoes neoplastic transformation and becomes a malignant cell. Transformed (malignant) cells escape normal physiologic controls specifying cell phenotype and restraining cell proliferation. Transformed cells in an individual's body thus proliferate, forming a tumor. When a tumor is found, the clinical objective is to destroy malignant cells selectively while mitigating any harm caused to normal cells in the individual undergoing treatment.
Chemotherapy is based on the use of drugs that are selectively toxic (cytotoxic) to cancer cells. Several general classes of chemotherapeutic drugs have been developed, including drugs that interfere with nucleic acid synthesis, protein synthesis, and other vital metabolic processes. These generally are referred to as antimetabolite drugs. Other classes of chemotherapeutic drugs inflict damage on cellular DNA. Drugs of these classes generally are referred to as genotoxic. Susceptibility of an individual neoplasm to a desired chemotherapeutic drug or combination of drugs often, however, can be accurately assessed only after a trial period of treatment. The time invested in an unsuccessful trial period poses a significant risk in the clinical management of aggressive malignancies.
The repair of damage to cellular DNA is an important biological process carried out by a cell's enzymatic DNA repair machinery. Unrepaired lesions in a cell's genome can impede DNA replication, impair the replication fidelity of newly synthesized DNA and/or hinder the expression of genes needed for cell survival. Thus, genotoxic drugs generally are considered more toxic to actively dividing cells that engage in DNA synthesis than to quiescent, nondividing cells. Normal cells of many body tissues are quiescent and commit infrequently to re-enter the cell cycle and divide. Greater time between rounds of cell division generally is afforded for the repair of DNA damage in normal cells inflicted by chemotherapeutic genotoxins. As a result, some selectivity is achieved for the killing of cancer cells. Many treatment regimens reflect attempts to improve selectivity for cancer cells by coadministering chemotherapeutic drugs belonging to two or more of these general classes.
Because effective chemotherapy in solid tumors usually requires a combination of agents, the identification and quantification of determinants of resistance or sensitivity to each single drug has become an important tool to design individual combination chemotherapy.
Two widely used genotoxic anticancer drugs that have been shown to damage cellular DNA are cisplatin (DDP) and carboplatin. Cisplatin and/or carboplatin currently are used in the treatment of selected, diverse neoplasms of epithelial and mesenchymal origin, including carcinomas and sarcomas of the respiratory, gastrointestinal and reproductive tracts, of the central nervous system, and of squamous origin in the head and neck. Cisplatin in combination with other agents is currently preferred for the management of testicular carcinoma, and in many instances produces a lasting remission. (Loehrer et al.,1984,100 Ann. Int. Med. 704). Cisplatin (DDP) disrupts DNA structure through formation of intrastrand adducts. Resistance to platinum agents such as DDP has been attributed to enhanced tolerance to platinum adducts, decreased drug accumulation, or enhanced DNA repair. Although resistance to DDP is multifactoral, alterations in DNA repair mechanisms probably play a significant role.
The glutathione-S-transferase (GST) family of proteins is involved in detoxification of cytotoxic drugs. By catalyzing the conjugation of toxic and carcinogenic electrophilic molecules with glutathione the GST enzymes protect cellular macromolecules from damage (Boyer et al., Preparation, characterization and properties of glutathione S-transferases. In: Zakim D, Vessey D (eds.) Biochemical Pharmacology and Toxicology. New York, N.Y.: John Wiley and Sons, 1985.). A certain isomeric type of these proteins, the glutathione S-transferase Pi (GST-pi, also to be interchangeably refered to as GSTP1 or GST-π herein) is widely expressed in human epithelial tissues and has been demonstrated to be over-expressed in several tumors (Terrier et al., Am J Pathol 1990; 137: 845–853; Moscow et al., Cancer Res 1989; 49: 1422–1428). Increased GST-pi levels have been found in drug resistant tumors, although the exact mechanism remains unclear (Tsuchida et al., Crit Rev Biochem Mol Biol 1992; 27: 337–384). Previous studies have suggested that low expression of GST protein (not mRNA) is associated with response to platinum-based chemotherapy (Nishimura et al., Cancer. Clin Cancer Res 1996; 2:1859–1865; Tominaga, et al., Am. J. Gastro. 94:1664–1668, 1999; Kase, et al., Acta Cytologia. 42: 1397–1402, 1998). However, these studies did not measure quantitative gene expression, but used a semi-quantitative immunohistochemical staining method to measure protein levels. However, quantitative GST-pi gene expression measurements are needed to achieve a very effective prognostication.
Most pathological samples are routinely fixed and paraffin-embedded (FPE) to allow for histological analysis and subsequent archival storage. Thus, most biopsy tissue samples are not useful for analysis of gene expression because such studies require a high integrity of RNA so that an accurate measure of gene expression can be made. Currently, gene expression levels can be only qualitatively monitored in such fixed and embedded samples by using immunohistochemical staining to monitor protein expression levels.
Until now, quantitative gene expression studies including those of GST-pi expression have been limited to reverse transcriptase polymerase chain reaction (RT-PCR) amplification of RNA from fresh or frozen tissue.
The use of frozen tissue by health care professionals poses substantial inconveniences. Rapid biopsy delivery to avoid tissue and subsequent mRNA degradation is the primary concern when planning any RNA-based quantitative genetic marker assay. The health care professional performing the biopsy, must hastily deliver the tissue sample to a facility equipped to perform an RNA extraction protocol immediately upon tissue sample receipt. If no such facility is available, the clinician must promptly freeze the sample in order to prevent mRNA degradation. In order for the diagnostic facility to perform a useful RNA extraction protocol prior to tissue and RNA degradation, the tissue sample must remain frozen until it reaches the diagnostic facility, however far away that may be. Maintenance of frozen tissue integrity during transport using specialized couriers equipped with liquid nitrogen and dry ice, comes only at a great expense.
Routine biopsies generally comprise a heterogenous mix of stromal and tumorous tissue. Unlike with fresh or frozen tissue, FPE biopsy tissue samples are readily microdissected and separated into stromal and tumor tissue and therefore, offer an advantage over the use of fresh or frozen tissue. However, isolation of RNA from fixed tissue, and especially fixed and paraffin embedded tissue, results in highly degraded RNA, which is generally not applicable to gene expression studies.
A number of techniques exist for the purification of RNA from biological samples, but none is reliable for isolation of RNA from FPE samples. For example, Chomczynski (U.S. Pat. No. 5,346,994) describes a method for purifying RNA from tissues based on a liquid phase separation using phenol and guanidine isothiocyanate. A biological sample is homogenized in an aqueous solution of phenol and guanidine isothiocyanate and the homogenate thereafter mixed with chloroform. Following centrifugation, the homogenate separates into an organic phase, an interphase and an aqueous phase. Proteins are sequestered in the organic phase, DNA in the interphase, and RNA in the aqueous phase. RNA can be precipitated from the aqueous phase. Unfortunately, this method is not applicable to fixed and paraffin-embedded (FPE) tissue samples.
Other known techniques for isolating RNA typically utilize either guanidine salts or phenol extraction, as described for example in Sambrook, J. et al., (1989) at pp. 7.3–7.24, and in Ausubel, F. M. et al., (1994) at pp. 4.0.3–4.4.7. Again, none of the known methods provides reproducible quantitative results in the isolation of RNA from paraffin-embedded tissue samples.
Techniques for the isolation of RNA from paraffin-embedded tissues are thus particularly needed for the study of gene expression in tumor tissues, since expression levels of certain receptors or enzymes can be used to determine the likelihood of success of a particular treatment.
There is a need for a method of quantifying GST-pi mRNA from paraffinized tissue in order to provide an early prognosis for proposed genotoxic cancer therapies. As a result, there has been a concerted yet unsuccessful effort in the art to obtain a quantification of GST-pi expression in fixed and paraffinized (FPE) tissue. Accordingly, it is the object of the invention to provide a method for assessing GST-pi levels in tissues fixed and paraffin-embedded (FPE) and prognosticate the probable resistance of a patient's tumor to treatment with DNA damaging agents, creating the type of lesions in DNA that are created by DNA platinating agents, by examination of the amount of GST-pi mRNA in a patient's tumor cells and comparing it to a predetermined threshold expression level.

Method of determining a chemotherapeutic regimen based on glutathione-s transferase pi expression


In a digital TV broadcast signal receiver connected to a multi-directional antenna called smart antenna, even when a user reshuffles a channel frequently, it is aimed to shorten a time delay between channel choice by the user and switching operation of the multi-directional antenna for switching signal receiving direction. Initially, sensitivities of TV broadcast signals of all receivable channels in all signal receiving directions are measured and measurement results are memorized in a memory. A signal receiving direction, in which a number of receivable channels is the largest, is decided as an optimum signal receiving direction with respect to each receivable channel. Even when the channel is reshuffled among these receivable channels, it is no need to switch the signal receiving direction of the multi-directional antenna. Consequently, the time for switching the signal receiving direction of the multi-directional antenna can be reduced even when the channels are reshuffled frequently.

1. Field of the Invention
The present invention relates to a digital television (TV) broadcast signal receiver that can receive digital television broadcast signals such as ATSC (Advanced television systems Committee).
2. Description of the Related Art
In the North American Continent where an ATSC digital television broadcast (it is abbreviated to a hereinafter digital TV broadcast) is performed, plains are dotted with metropolises, so that various digital TV broadcast signals broadcasted in the suburbs of each metropolis can be received at other cities or the halfway point of the cities. In consideration from a user who receives the TV broadcast signals, since many TV broadcast signals are transmitted in various directions, it is necessary to regulate a direction of an antenna in an orientation to a TV broadcasting station from which a program which he wants to watch is delivered. Therefore, a multi-directional antenna such as a smart antenna is put into practical use.
As described in Japanese Laid-Open Patent Publication No. 10-233969, the TV broadcast signal receiver is generally set preferentially to receive a channel with a higher sensitivity of a TV broadcast signal. In Japanese Laid-open Patent Publication No. 2002-335458, a digital TV broadcast signal receiver displays numbers of receivable channels in different colors corresponding to sensitivities of TV broadcast signals, for visually indicating signal receiving conditions to the user. In Japanese Laid-Open Patent Publication No. 2002-353832, field strength of received TV broadcast signals and error rates of digital data are used to set a receive direction of an antenna in a digital TV broadcast receiver. In Japanese Laid-Open Patent Publication No. 2000-269786, which relates to FM broadcasting, in an area having many broadcast stations channels with low noise broadcast signals are selected, and in another area having a few broadcast stations, the conditions for noise of the broadcast signals is sweetened in order to increase a number of channels selectable.
According to the EIA-909 technical standard, it is provided that a smart antenna has sixteen signal receiving directions in respective directions where a circle is divided into sixteen. A digital TV broadcast signal receiver in compliance with the EIA-909 technical standard can adjust the signal receiving direction of the multi-directional antenna such as the smart antenna in all sixteen signal receiving directions.
By the way, there are many types of the multi-directional antenna, for example, a type for rotating an antenna with a motor for switching the signal receiving direction, or a type with a plurality of antennas and electronic switches in which a signal receiving direction is switched by switching on and off of the electronic switches. A term necessary for switching the signal receiving direction of the multi-directional antenna due to switching on and off of the electronic switches is approximately 10 ms extent with no relation in model. In contrast, a term necessary for switching the signal receiving direction of the multi-directional antenna in which the antenna is rotated with the motor is uneven in a range from 100 ms to 200 ms extent due to power of the motor and angle of rotation of the antenna. When the digital TV broadcast signal receiver has no function for distinguishing the kinds of the connected multi-directional antennas or for setting a term for switching the signal receiving direction optionally, the term for switching the signal receiving direction of the digital TV broadcast signal receiver is set to the longest term necessary for switching the signal receiving direction of the multi-directional antenna among the ones available in the market.
In general, a direction having the highest sensitivity of the TV broadcast signal among the directions in which the TV broadcast signal can be received is defined as an optimum signal receiving direction with respect to each channel. Then, the switching operation of the TV broadcast signal receiver is performed whenever a user chooses a channel so that the signal receiving direction of the multi-directional antenna is switched to the optimum signal receiving direction of the channel which is selected by the user. While a term for switching the signal receiving direction of the digital TV broadcast signal receiver, no image is displayed on a monitor screen, and the switching of the channel will be delayed. Especially when the user reshuffles the channel frequently, the switching operation of the signal receiving direction of the multi-directional antenna cannot catch up with the channel reshuffling operation, and it causes the irritation of the user.

Digital television broadcast signal receiver


An mileage communication system for a vehicle, such as a trailer, is disclosed. Mileage data is communicated to a processor by a sensor. The processor calculates cumulative mileage and encodes the mileage data into a code, such as an ON-OFF code, that is capable of being communicated to an output device. The vehicle operator may activate a user interface that is capable of generating a request signal to be sent to the processor. Upon receipt of the request signal, the processor communicates the code to the output device. In response to the code from the processor, the output device communicates a visual or audible signal, such as an ON-OFF signal, that is capable of being received by the vehicle operator or other user. The signal corresponds to the cumulative mileage data.

The invention relates in general to an electronic odometer for a trailer. More specifically, the invention provides a device and method for communicating odometer data to a vehicle user by controlling an output device with an ON-OFF code signal.
Cumulative mileage information for a trailer may be used to track the need for scheduled maintenance on the trailer. On a tractor, it is relatively common for the vehicle to have a numerical odometer which displays cumulative mileage to the user. On trailers, however, such numerical odometers are not often available.
An odometer function is presently incorporated into the electronic control units (ECU) of many antilock braking systems (ABS) intended for use on heavy duty tractors and trailers. The trailer-mounted ABS ECU can be used to provide odometer mileage information. To display the cumulative mileage from the trailer ABS ECU, however, the user must connect the trailer ABS ECU to an off diagnostic tool having a multi-character alpha-numeric display. With such conventional systems, the cumulative mileage for a trailer cannot be displayed without an off-board diagnostic tool.