In the present invention, a potable water treatment system and apparatus for purifying and treating potable water that is being transferred from a potable water source to a number of potable water user(s) via a potable water line is presented. Said potable water purification and treatment system and apparatus has a filter capable of filtering the potable water to an NTU of less than 0.10, removing TOC and disinfection by-products, as well as a chemical feed system which comprises a measuring device for measuring at least one of: the potable water flow and the potable water quality, at least one proportioning device for determining any amount(s) of chemical additives utilizing input(s) from the measuring device(s) and at least one chemical feed pump to transfer at least one chemical additive to the potable water, wherein at least a disinfectant is added to the potable water downstream of filtration. In addition to disinfectant addition, said potable water purification and treatment system and apparatus has the capability to add at least one of a: chelant, dispersant, oxidizer, metal coagulant, buffer and/or any combination therein. While the measuring device, proportioning device and/or chemical pump can be one unit, each can be separate or combined in any combination providing that the required chemical(s) and amount of chemical(s) is pumped or successfully transferred to the potable water. The method of operation of the potable water treatment system and apparatus is also presented.

A major issue with which potable water consumers (including, but not limited to residential, office, public and commercial buildings) have been faced is the ability to control at least one of: taste, odor, turbidity, bacterial and/or viral contamination, heavy metal contamination, hardness, mineral deposits and/or a combination of these water quality parameters form potable water sources. Calcium and/or magnesium exist in potable waters in the form of salts, which are normally soluble in the form of sulfates, carbonates, bicarbonates or chlorides. Often the soluble salts are ionized so that the water contains a relatively high concentration of calcium and/or magnesium ions. While waters can be classified according to hardness as soft water or hard water, the harder is the water the greater the amount of calcium and/or magnesium. In low hardness, soft, potable waters, the water is often acidic causing the corrosion of metal materials thereby placing soluble metal ions in the water, which are dangerous to health and reduce the life of metal materials.
Current technologies for mineral and/or metal removal involve distillation, lime-softening, cation exchange, water softening compounds and membrane filtration. By distillation, condensation of steam provides pure water, which has been evaporated from the mineral and metal ions. Distillation is very energy intensive; and, very pure water from distillation is not good for human health as water which is too low in mineral content will literally remove minerals from the human body into the bloodstream as the body absorbs the water. Lime softening plants are very expensive to build and to operate; therefore, these plants are not installed as often as needed. Cation exchange softening is performed, wherein sodium and/or potassium is exchanged for the mineral nutrient of calcium and/or magnesium. Cation exchange softeners cause an increase in the sodium or potassium content of the water and a near elimination of calcium and/or magnesium, which are both nutrients required for good health. Water softening compounds (e.g. sodium carbonate (washing soda), tri-sodium phosphate which is sold under various trade names, lime soda ash (sodium phosphate) and sodium silicate) which are used for softening potable water, also place sodium in the water; and under conditions of high concentration, can render the water highly alkaline, which is objectionable to human health. High amounts of alkalinity will also attack the fibers in clothes during washing. High amounts of alkalinity resulting from water softening compounds can render the water salty. Another technology, which has seen increased use is membrane filtration or reverse osmosis filtration. While effective, these systems are costly, require regular replacement and remove calcium and/or magnesium from the water to the point of the water not being good for human health, similar to distillation.
In addition to hardness, heavy metals contaminate potable water; heavy metals that contaminate may be but are not limited to: iron, copper, chromium, aluminum, manganese, zinc, cadmium, lead, tin, titanium, nickel, arsenic, silica, silicates and others. Contamination and the combination of contaminant(s) depend on the source of the potable water.
Heavy metal contamination is bad for human health and leads to staining and/or deposition on material surfaces. Metals and/or heavy metals can be measured in water by spectraphotometry. Contamination of potable water by metals, in the form of hardness and/or in the form of heavy metals, may deposit on the surface of materials. Deposition is dependent upon the water chemistry, yet is normally one of two types: scale deposits and sludge deposits. These deposits are often found on the inside of water lines and water heaters, as well as on the surface of materials which contact the water such as: glassware, tile, faucets and showerheads. Scale deposits are normally crystallized metal salts and sludge deposits are normally salts which have crystallized elsewhere consisting of discrete and usually non-uniform particles. Compared to other precipitation reactions, the crystallization of scale deposits is a slow reaction and, thus promotes the formation of a fairly well-defined, slow, in-place crystal growth, resulting in deposition of a hard, dense, glassy and highly insulating material.
Scale deposits can localize corrosion causing water lines and equipment to leak. After deposition has started, the deposits become bound to one another. Scale deposits often result in equipment replacement, such as water heaters, tile, glassware, piping, etc. Sludge deposits are not such a challenge; sludge deposits, though, are unsightly to the homeowner or potable water user.
Large scale water treatment facilities use coagulation and filtration to remove solids from water to make the water potable. While this is possible in surface water, solids are often not removed from well water. In any event, often surface water treatment does not adequately and effectively remove solids, as well as adequately remove solid forming or scale forming impurities from the water. Various chemical water treatments have been used to prevent and remove scale and sludge from water.
Years ago, phosphate control was introduced to minimize wide-spread calcium carbonate scaling throughout water lines by eliminating calcium carbonate scale formation in favor of a precipitate that could produce sludge. Inhibitors used to inhibit calcium and magnesium salt scale and the localized corrosion due to salt scale are: inorganic phosphate compounds, such as phosphoric acid, pyrophosphoric acid, hexametaphosphates, pyrophosphates, polypyrophosphates, polyhexametaphosphates and organic phosphoric compounds such as alkyl phosphates or phosphonates. An adequate inhibitor concentration can easily be determined by measuring the conductivity in the water, as chelated minerals and/or metals are not conductive. If insufficient water alkalinity is maintained, however, magnesium can combine with phosphate, forming magnesium phosphate, a particle with a surface charge that makes it very prone to adhere to materials, especially metal equipment. Further, use of the low molecular weight acid variants may lead to corrosion on metal surfaces and in high concentrations and/or at high temperatures (normally above 130° F.) all of these inhibitors can lead to the formation of phosphate and/or chloride salt scale, wherein the cation may be at least one of: calcium, magnesium, silica and/or a combination thereof. Potable water chemical treatments generally involve a chelating or precipitating agent such as soda ash, phosphoric acid, pyrophosphoric acid, sodium or potassium phosphate, sodium or potassium phosphate polymers (such as polyhexametaphosphates or polypyrophosphates, etc.) or organic phosphate polymers (such as sodium or potassium phosphonates) and/or a combination of these. However, high concentration or high temperature scale deposition is not solved in potable water with these inhibitors.
Industrially, in very high temperature applications, dispersants have been utilized to prevent the formation of scale and/or sludge from phosphate and/or chloride salts. These dispersants are normally derived upon acetate or acrylate chemistry. However, these chemicals have had sparing use in potable water treatment and have only been applied at the surface water treatment facility or in combination with membranes to limit membrane fouling, if used at all. Further, the use of phosphate inhibitor chemistry is infrequent in potable water.
The chemistry of using a phosphate to chelate calcium, magnesium and metals is well known. Alkalinity, hardness and temperature are the factors in using phosphates for chelation. Alkalinity or hardness can be measured with spectraphotometry. Municipalities have on an infrequent basis been adding a variety of phosphates and phosphate polymers to potable water for decades to control mineral and metal deposition. However, the goals of municipalities and the goals of potable water users are rather incongruent. Municipalities add phosphates and phosphate polymers to control corrosion and/or scaling in metal pipes of water lines and to control consumer complaints from mineral and/or metal deposition staining on clothing and plumbing fixtures. In recent years, some municipalities have begun to install concrete and plastic pipes for water lines and, thus, no longer add any phosphate polymers to the potable water. Again, even if municipalities would provide enough phosphate or phosphate polymer to potable water to prevent low temperature scale, at temperatures above 130° F., high temperature salt scale deposition will still occur. Municipalities do not add any dispersing agent(s) to prevent calcium, silicon, silica or magnesium phosphate build-up in hot water lines and equipment. As a result, potable water users often must pay additional expenses for at least one of: laundry, cleaning, plumbing, plumbing fixtures, bathroom fixtures, tile, glass, appliances and water heating equipment due to the formation of phosphate salt mineral deposits, wherein the cation is at least one of calcium, silica, magnesium and/or a combination thereof.
Further, NSF International analyzes the toxicity of chemical additives to drinking water, potable water, applications. Phosphates, dispersants, metal coagulants and disinfectants as well as any chemical, have a dosage limit in their application in potable water; therefore, the addition of phosphates, or any chemical for that matter, to a potable water stream must be regulated and proportioned to the water flow rate.
Turbidity is a critical parameter to human health in potable water. Turbidity is a measure of particle contamination, which is performed by sending and receiving light scatter through a sample of the water; turbidity is reported as NTU (Nephelometric Unit). Turbidity is used as a measure of bacterial, viral and/or animal contamination. Animal contamination can exist from species such as Cryptosporidium parvum and/or Giardia lamda; contamination from these animal species is of particular importance due to their known ability to cause waterborne disease. In particular, Cryptosporidium is the contaminant that made thousands sick in Milwaukee causing The U.S. EPA to re-evaluate the drinking water standards. Giardia is particularly common from animal feed lots, cattle and pigs. For the elderly, infants and/or those with weakened immune systems, infection can be fatal, as occurred to dozens in Milwaukee. Ninety-seven percent of surface water sources and most of the well water sources are known to be contaminated with animals and nearly all sources are contaminated with at least one of bacteria, virus and/or animal species. Research by The U.S. EPA has determined that an NTU of 0.10 or less reduces these contaminates by 4 to 6 log, as well as to concentrations which are of less concern and with which the human body can cope.
TOC and disinfection by-products are both critical parameters to human health. TOC is critical because TOC reacts with disinfectants to form disinfection by-products. Disinfection byproducts are carcinogenic and/or teratogenic, as well as toxic. TOC can be reliably measured in potable water by spectraphotometry. The U.S. EPA has regulations for the allowable concentration of TOC and of disinfection by-products in drinking water.
There are currently many Point-of-Use (POU) devices and Point-of-Entry (POE) devices known in the art of potable water purification. POU devices are designed, literally, for the point of use, a.k.a. a sink, refrigerator, washing machine, showerhead, etc. POE devices are designed for the point of entry into the building, a.k.a. the water line at entry. These devices have one common feature, a filter media. This filter media is made of carbon, cloth or of membrane construction and is sized so as to be rated in microns of porosity to determine particle filterability. However, these devices have another feature; these devices do nothing to control mineral or metal salt deposition. Further, these devices are a health risk to the potable water user since the disinfectant (which is normally chlorine, yet can be chloramine, bleach or chlorine dioxide) is removed by the filter media leaving the remaining section of pipe, equipment, plumbing, fixture or appliance available to biological and/or viral growth. Disinfectant concentration can easily be measured with spectraphotometry.
The present invention is the first potable water purification device, POU or POE, which provides the ability to maintain calcium and/or magnesium in the water while providing protection from scale and sludge deposition. The present invention is the first potable water purification device that filters the water while maintaining a disinfectant concentration in the water downstream of the filter media to control bacterial and viral growth.
In the prior art, devices and systems that have been used to add a chemical to potable water at potable water pressures resort to first passing the potable water into a reservoir and then dripping chemical additives in to the reservoir with a pump. Methods of application of such systems and devices can be relatively complex and costly and require very careful control. The present invention does not require passing of the potable water into a reservoir. In the present invention, the potable water can be purified and treated without using any complicated equipment. In a preferred embodiment, the chemical additive(s), which is at least a disinfectant, which can be combined with at least one of: an oxidizer, a chelant, a dispersant and/or a combination thereof is added to the water by using a measuring device, a proportioning device and a chemical pump. Thus, the potable water treatment system and apparatus is preferred particularly for the potable water users. The potable water users can obtain a filtered and disinfectant containing potable water, which: has been oxidized prior to filtration if necessary, chelated if necessary and dispersed if necessary, wherein the natural mineral ions are maintained in the water without an increase to the alkalinity of the water, thereby not creating water that can damage the skin, piping, fixtures, tile, water heating equipment or any material in contract with the water, nor create water which will reduce the mineral content of the human body or add sodium to the human body.
Several related patents that have been issued in the past decades are:
U.S. Pat. No. 1,903,041 issued to Hall, et al., on Mar. 28, 1933 presents a water treatment process in a steam boiler, wherein a chemical containing a molecularly dehydrated phosphate radical is supplied to the boiler water and is then re-hydrated in the water to a condition of greater alkali-neutralizing capacity.
U.S. Pat. No. Re. 19,719 issued to Van Tuyl on Oct. 8, 1935 presents a process of softening water containing an alkaline-earth metal compound. The process comprises adding an alkali-earth metal phosphate which is water soluble and capable of sequestering calcium in a slightly ionized condition in an amount sufficient to effectively suppress the soap-consuming alkaline-earth metal ion concentration.
U.S. Pat. No. 2,142,515 issued to Joos on Jan. 3, 1939 presents a water softening method which comprises treating water in a reaction zone with lime and soda to reduce the hardness of the water. In a second reaction zone, the water is treated with tri-sodium phosphate and sodium hydroxide in proportions to provide in the treated water an excess of tri-sodium phosphate.
U.S. Pat. No. 2,304,850 issued to Rice on Dec. 15, 1942 presents a process of precipitating dissolved ions in well water. The process comprises adding to the water in the well, before it is exposed to air, molecularly dehydrated alkali-metal phosphate in a part per million concentration ratio to the ion concentration.
U.S. Pat. No. 2,596,943 issued to Sheen on May 13, 1952 presents a proportional feed system. The proportional feed system is an electric proportioning pump for supplying liquid to a system in response to electric circuit operation, comprising a solenoid adapted to be energized at intervals by the electric circuit operatively connected to the pump and controlling the extent and speed of operation of the pump and adjustable stop in the shock absorber for limiting the length of stroke of the pump.
U.S. Pat. No. 2,874,719 issued to Van Tuyl on Feb. 24, 1959 presents a device for feeding additives into a moving liquid. The device comprises a housing having an additive supply source, a first bore and a second bore being spaced from each other, an additive inlet channel leading from the additive supply source to the first bore, an additive outlet channel being offset laterally from said additive inlet channel, means in the second bore restricting the flow of liquid in the second bore, and, disposed between said additive inlet channel and said additive outlet channel, a valve assembly incorporating a check valve responsive to the flow of liquid in the second bore and a manually adjustable needle valve for controlling the rate of flow of the additive through said additive outlet channel into the second bore, one of the valves being disposed within the other.
U.S. Pat. No. 4,209,398 issued to Li, et al., on Jun. 24, 1980 presents a process for treating water to inhibit formation of scale and deposits on surfaces in contact with the water and to minimize corrosion of the surfaces. The process comprises mixing in the water an effective amount of water soluble polymer containing a structural unit that is derived from a monomer having an ethylenically unsaturated bond and having one or more carboxyl radicals, at least a part of said carboxyl radicals being modified, and one or more corrosion inhibitor compounds selected from the group consisting of inorganic phosphoric acids and water soluble salts therefore, phosphonic acids and water soluble salts thereof, organic phosphoric acids and water soluble salts thereof, organic phosphoric acid esters and water-soluble salts thereof and polyvalent metal salts, capable of being dissociated to polyvalent metal ions in water.
U.S. Pat. No. 4,442,009 issued to O'Leary, et al., on Apr. 10, 1984 presents a method for controlling scale formed from water soluble calcium, magnesium and iron impurities contained in boiler water. The method comprises adding to the water a chelant and water soluble salts thereof, a water soluble phosphate salt and a water soluble poly methacrylic acid or water soluble salt thereof.
U.S. Pat. No. 4,631,131 issued to Cuisia, et al., on Dec. 23, 1986 presents a method for inhibiting formation of scale in an aqueous steam generating boiler system. Said method comprises a chemical treatment consisting essentially of adding to the water in the boiler system scale-inhibiting amounts of a composition comprising a copolymer of maleic acid and alkyl sulfonic acid or a water soluble salt thereof, hydroxyl ethylidenel, 1-diphosphic acid or a water soluble salt thereof and a water soluble sodium phosphate hardness precipitating agent.
U.S. Pat. No. 4,640,793 issued to Persinski, et al., on Feb. 3, 1987 presents an admixture, and its use in inhibiting scale and corrosion in aqueous systems, comprising: (a) a water soluble polymer having a weight average molecular weight of less than 25,000 comprising an unsaturated carboxylic acid and an unsaturated sulfonic acid, or their salts, having a ratio of 1:20 to 20:1, and (b) at least one compound selected from the group consisting of water soluble polycarboxylates, phosphonates, phosphates, polyphosphates, metal salts and sulfonates. The Persinski patent presents chemical combinations which prevent scale and corrosion; however, the Persinski patent does not address potable water, drinking water, the filtration of potable water, the addition of disinfectants or an apparatus or a method of addition of a at least one of: chelants, dispersants and disinfectants to potable water. More specifically, Persinski does not at all address the importance of removing solids or metals from the water. Persinski specifically states, "The instant invention is also directed to a method of inhibiting the formation of insoluble alluvial, metal oxide and metal hydroxide deposits in an aqueous system . . . " As soluble compounds, metals are much more difficult to remove by filtration; therefore, under a worst case scenario Persinski presents technology which would be toxic in applications wherein heavy metal(s) are present in the drinking water. Under a best case scenario, Persinski presents technology which in drinking water would lead to the disinfectant oxidizing the soluble metal(s), which would lead to taste issues. In any event, Persinski presents a technology wherein the metals could not be removed or would be very difficult to remove. In contrast, an insoluble alluvia metal, a metal oxide or a metal hydroxide can be easily filtered. Further, a metal in its cationic valence state can be removed via many chemical mechanisms, most of which entail the use of sulfur.
U.S. Pat. No. 4,855,061 issued to Martin on Aug. 8, 1989 presents an apparatus for controlling a coagulant dosage rate. This apparatus includes a charge sensor located adjacent a coagulant pump for measuring the net electrical charge on coagulated water before water treatment and a turbidity meter for measuring the effluent turbidity after water treatment. While Martin discloses an apparatus to control a coagulant dosage, thereby controlling water turbidity, Martin does not address water scale, filtration or the addition of either a chelant, dispersant or a disinfectant. Lastly, Martin does not discuss the treatment of potable water. It is very unlikely that potable water would require a coagulant, as coagulants are added to raw waters, not to potable waters.
U.S. Pat. No. 5,254,264 issued to Armstrong on Oct. 19, 1993 presents a method of dispensing scaling inhibitors into a flow of low-pressure water by modifying the use of available air lubricators.
U.S. Pat. No. 5,178,768 issued to White, on Jan. 12, 1993 presents a mixed filter bed composition for purifying water for human consumption containing inorganic, organic and biological contaminants, said composition comprising: (a) from about 40% to about 80% by weight of carbonous sorbent; (b) from about 5% to about 20% by weight of activated alumina; (c) from about 5% to about 20% by weight of silica hydrogel; (d) from about 5% to about 20% by weight of zeolite; and (e) from about 0% to about 10% by weight of metallic components that generate metallic cations. While White discloses a novel filter media combination, White does not describe a method for controlling scale of sludge deposits in potable water. Most significantly, White does not disclose a method for adding a disinfectant to the water after filtration; the While filtration design leaves the water susceptible to bacterial and viral contamination after filtration. The only method around such a contamination issue with White would be to leave enough metallic cations in the water after filtration to eliminate biological or viral growth; such a design would leave the water outside of the heavy metals requirements as set forth by the U.S. EPA and/or NSF International, as such the water would be toxic and not be fit for human consumption. Further, White does not disclose an apparatus or method of chemical addition to potable drinking water.
U.S. Pat. No. 5,419,836 issued to Ray, et al., on May 30, 1995 presents a method for dispensing a plurality of additives into untreated ground water contained in a poultry watering system. The method comprises supplying untreated ground water contained in a poultry watering system, circulating the water, fluidly connecting a plurality of feed containers containing the plurality of additives to the water, the additives including a scale inhibitor and an oxidant, proportionately dispensing, in relationship to flow, the plurality of treatment additives using hydraulically operated pumps and filtering unwanted matter from the water. While it is obvious that Ray is the closest prior art to the invention, Ray does not provide a system of treatment that would be applicable to potable, drinking, water. Ray does not discuss the use of a dispersant when dispersants would be required in water heating applications; this only follows since the methods of Ray are for industrial and poultry applications. Further, Ray specifically states that "Feed pumps, such as hydraulic pumps, proportionally dispense the additives into the water stream. Then, a filter removes unwanted matter." Further, the figure associated with the Ray patent clearly shows the filter as the last piece of equipment. This method is not viable in drinking water, as the filter if at all capable of removing organics will also remove the oxidant or disinfectant, thereby leaving the water without a disinfectant and capable of contamination with bacteria and/or viruses downstream.
U.S. Pat. Nos. 5,575,919 issued to Santina on Nov. 19, 1996; 5,866,014 issued to Santina on Feb. 2, 1999; and 6,093,328 issued to Santina on Jul. 25, 2000 present that Arsenic and TOC are removed from drinking water or wastewaters by use of finely-divided metallic iron in the presence of powdered elemental sulfur or other sulfur compounds such as manganese sulfide, followed by an oxidation step. A premix may be produced for this process, by adding the iron, sulfur and oxidizing agent to water in a predetermined pH range. The iron and sulfur are mixed for a period of time dependent upon the temperature and pH of the water and the presence of complexing or sequestering minerals and organic acids in the water. An oxidizing agent is added to the mixture and agitating is continued. In a preferred embodiment the oxidizing agent is hydrogen peroxide. Water is decanted from the mixture after a sufficient reaction time, to produce a concentrated premix. This premix can be added to water intended for drinking or to industrial effluents containing toxic materials. Santina presents compositions, all of which contain an iron sponge, along with sulfides. While very good at removing Arsenic, these compositions will add soluble iron to the water and have the potential of adding sulfides to the water. Iron, while a nutrient can stain porcelain fixtures. Sulfides are odiferous with an odor threshold of a part per billion in air. Santina does not teach or suggest a method of controlling scale deposits, removing bacteria and viruses or adding a disinfectant.
U.S. Pat. No. 6,368,510 issued to Friot on Apr. 9, 2002 presents a method and apparatus for removing arsenic from water at point of entry or point of use particularly for residential application. The point of entry system comprises a first stage having a manganese greensand oxidizer to convert arsenite (As+3) present in the water to arsenate (As+5) and a second stage for passing the water through an anion exchange resin. Each stage includes a control head for automatic regeneration at a predetermined frequency. The manganese greensand is regenerated with a solution of potassium permanganate and the anion exchange resin is regenerated with a salt solution. An alternate embodiment for point of use application comprises a manganese greensand oxidizer cartridge to convert arsenite (As+3) to arsenate (As+5) followed by removal of the arsenate (As+5) with a reverse osmosis system.
U.S. Pat. No. 6,387,276 issued to Nikolaidis on May 14, 2002 presents a method for the remediation of arsenic, comprising providing an aqueous solution of inorganic arsenic species, and passing the solution of inorganic arsenic species over a substrate comprising zero valent iron under anaerobic conditions, thereby reducing the arsenic species and forming arsenic-metal co-precipitates. Preferably, the metal is iron in the form of iron filings, and a source of sulfate ions is also present, resulting in the precipitation of arseno-pyrites.
U.S. Pat. No. 6,461,535 issued to Esparza on Oct. 8, 2002 presents a method of Arsenic removal from water. The process includes (a) contacting a clay, a coagulant, and an oxidizer with water containing arsenic to form a coagulated colloidal mixture; (b) adsorbing the arsenic onto the coagulated colloidal mixture; and (c) separating the water from the coagulated colloidal mixture. The invention also provides a composition ready for use in removing arsenic from ground water to be used in remote areas. The composition includes an activated clay, a coagulant, and an oxidizer in predetermined proportions for efficient removal of arsenic from ground water. Esparza requires the use of a coagulant and clay, along with a method of removing the colloidal precipitates.
These registered patents do not take into account a method, a system or an apparatus for treating municipal potable water or well water for human consumption that is available for use by potable water using entities, wherein the water is: filtered with a carbon media to remove organic contaminants, filtered to less than 1 micron or less than 0.10 NTU to remove biological or viral contaminants, chelated with at least one of: calcium, magnesium, iron or manganese in combination with dispersing any chelated minerals and/or dispersing any mineral salts, removing any heavy metals and disinfecting the water, while performing any and all chemical additions proportionately to a concentration that is within NSF Guidelines.

Potable water treatment system and apparatus


A novel food processing system for dividing a flow of food items into a plurality of streams, gently and quickly transporting the food items along a flume of fluid propelled by eductors to several slicers, transversely slicing the food items at a controlled rate to maximize yield, washing the slices, transporting the slices and controllably distributing the slices onto a conveyor for further processing. In accordance with one embodiment of the present invention, the food processing system comprises an oversized-product separator, a segmented cutter, a mass-flow/spreading conveyor, a diverter stage, an eductor stage, a dewatering stage, a starch removal stage, a slicer infeed conveyor, at least one transverse slicer, and a slice spreader. In a preferred embodiment, cutting losses are decreased by minimizing slicing speeds.

1. Technical Field
The present invention relates to a system for processing food items to form slices. More specifically, this invention relates to hydraulically transporting food items with the use of an eductor, reducing the size of large items using a segmented cutter, maximizing cutting efficiency by controlling velocities and mass flow rates, slicing food items with a transverse slicer, controlling slicing velocities to optimize performance, and controllably spreading the resulting slices upon a conveyor for further processing.
2. Description of Related Art
The commercial process of processing produce such as vegetables, tubers, nuts, and fruit requires sized reduction of large volumes of food stuffs. The present invention will be described in terms of transporting and slicing potatoes to make potato chips. However, as those skilled in the art will appreciate, the present invention can be employed for a wide variety of uses other than making potato chips.
Prior art industrial-sized potato slicing systems typically use centrifugal slicers to cut potatoes into slices, which can be used to make products such as potato chips, or dishes such as scalloped potatoes and au gratin potatoes. A centrifugal slicer, such as the Urschel Model Continuous Cut ("CC") Slicer, manufactured by Urschel Laboratories, Inc., comprises several upright blades arranged in a ring around a central impeller or rotary disk. FIG. 6 of U.S. Pat. No. 5,694,824, granted to Jacko et al., for example, shows one such prior art centrifugal slicer. As potatoes are fed into the slicer, the rotating impeller or disk initially throws potatoes against the blades and then pushes the potatoes across the blades, thereby shaving slices from the potatoes.
Centrifugal-type slicers, however, have several drawbacks. One such drawback is reduced yield due to high slicing velocities. In order for centrifugal slicers to work properly, a minimum amount of rotational speed is required to create the centrifugal force necessary to force the potatoes against the cutting surfaces. As a result of the relatively high slicing and impact speeds, centrifugal slicers (or cutters) generally produce a considerable amount of waste and scrap. For example, a potato can be damaged when it is thrown against the slicer walls between blades, as well as when a blade merely nicks the surface but fails to remove a slice. Furthermore, the high slicing speeds cause a significant amount of potato cell damage. A potato's starch-containing cells are viscoelastic, which means that the more quickly pressure is applied during slicing, the more brittle the cell walls become. Thus, the number of potato cells damaged per slice increases as the slicing speed increases. When potato cells break, the contained starch is released, resulting in reduced product yield. As much as 16% by weight of the potato feed can be lost to waste, scraps, and cell damage when using centrifugal slicers.
A second drawback of centrifugal-type slicers is the undesirable level of cracking that such slicers can impart in the slices. Because the viscoelastic potato cells become more brittle with increased blade impact speed, the slices become more likely to crack as the impact speed increases. Such cracking undesirably increases the occurrence of slice fold-overs and the amount of oil-uptake.
In addition, centrifugal slicers can only accommodate round chipping potatoes and cannot accommodate large elongated potatoes. Elongated potatoes tend to plug centrifugal slicers. Elongated potatoes also tend to lay sideways in such slicers, which undesirably increases variability in slice thickness. Moreover, centrifugal slicers create undesirably shaped, oblong potato chips when supplied with normal elongated potatoes. FIGS. 1a and 1b show examples of slices produced when a centrifugal slicer is supplied with a round potato 110 versus an elongated potato 140. A centrifugal slicer will slice a round chipping potato 110 into round slices with ridges 130 or without ridges 120, depending upon whether the slicer's blade edges are corrugated. In contrast, a centrifugal slicer will slice an elongated potato 140 lengthwise into oblong slices with or without ridges 160, 150, depending on whether the blade edges are corrugated. While some variation in slice or chip shape is acceptable, slices or chips having extreme aspect ratios (ratio of length to width) may be undesirable in some circumstances. Thus, elongated potatoes are generally not used in centrifugal slicers because of the potentially undesirable oblong-shaped slices they produce.
Although several non-centrifugal-type cutters exist for processing potatoes, few of them relate specifically to creating potato slices suitable for products such as potato chips. For example, U.S. Pat. Nos. 5,394,793, and 5,343,791, granted to Julian et. al., disclose rotating cutting head assemblies for cutting singular potatoes into helical strips. As the spiral cutting heads rotate, they make continuous helical bores through singular potatoes, thus making helical strips. The devices disclosed in the '793 and '791 patents, however, are not suitable for cutting potato slices.
A few potato slicer systems use horizontal discs with blades to slice potatoes. For example, U.S. Pat. No. 4,706,556, granted to Wallace et al., discloses a horizontal slicing disc with an inclined potato feeding tube. Wallace et al. teach that the potatoes must be individually removed from a washer drum and deposited into the slicer's feed tube. Prior to the current invention, however, there has been no automated slicing system for maximizing cutting efficiency and product yield. More specifically, there has been no automated system for controlling the feed rate of the potatoes to a transverse slicer and slicing the potatoes at an automatically controlled and reduced slicing speed.
Many prior-art slicing systems transport potatoes from one place to another by propelling them with an impeller-type food pump such as the Single Port Impeller Pump manufactured by the Cornell Pump Company. A significant number of the potatoes, however, are damaged as the potatoes travel through the pump and are struck by the rotating impeller. Furthermore, impeller-type food pumps draw a significant amount of energy and can therefore be expensive to operate. The cost of periodically replacing the impellers due to wear and tear also adds to the operating and maintenance costs. Other slicing systems, with the use of a venturi, accelerate a flow of solid food items and water through a set of stationary blades. For example, U.S. Pat. No. 5,390,590, granted to Mendenhall, discloses both concepts. Mendenhall discloses a hydraulic cutter in which a centrifugal food pump sends potatoes and water through a venturi tube, which in turn accelerates the potatoes through a grid of stationary blades. Slicing systems such as that disclosed in Mendenhall, however, relate to processes for making french fries and are not suitable for making potato chips or other products using potato slices. Prior to this invention, few potato slicing systems have used an eductor/venturi system to gently transport potatoes in a non-destructive manner throughout a process for making slices. Furthermore, no prior art slicing system has used a plurality of diverters to divide a stream of food items into several independently controlled streams, gently fed such food items into and propelled such streams through a manifold of several independently controlled eductors.
Prior art potato processing systems use potato halvers, such as Grove Dale Corporation's Auto Halver, to reduce the size of potatoes that are too large for processing. These potato halvers cut potatoes cross-wise along the short axis to reduce the overall length of oversized potatoes by half. Such halvers, however, are not suitable in potato slicing systems in which potatoes are cut into transverse slices, since such cutters do not reduce the diameter of potato pieces in the minor dimension.
Another problem encountered with prior art methods and devices is that the resulting potato slices often undesirably clump together as they exit the slicers and are moved downstream for further processing. Slice clumping prevents the slices from being evenly distributed upon a conveyor. Slice clumping also hinders the slices from being properly baked, toasted, or fried.
Resulting potato slices often contain slicing scraps, loose starch and other undesirable fines that are desirably removed from the slices before further processing. Prior art slicing systems typically remove loose starch, slicing scraps and fines by transporting slices to, and processing them through, a separate washing unit. Thus, there is a need for a simplified method for removing loose starch and slicing scraps.
Consequently, a need exists for a food processing system that can slice food items such as potatoes with less waste and scrap, as well as accommodate a wider variety of food shapes. More specifically, such a system should process potatoes with a relatively slower slicing speed and accommodate both round and oblong potatoes by slicing potatoes transversely. Such a system should also reduce oversized potatoes by slicing them lengthwise into smaller-diameter segments. The novel system should transport potatoes and potato segments in a flume of fluid towards at least one slicer with the use of an eductor/venturi system that gently propels potatoes in a non-destructive manner. Once cut, the system should transport the slices in a flume of fluid for further processing. Such a flume of fluid should also wash away loose starch, remove slicing scraps and remove undesirable fines from the slices. In addition, such a slicing system should prevent slice clumping and controllably distribute slices upon a conveyor leading to the next processing unit operation. Such a system should preferably be automated, but it should also be amenable to manual operation if desired.


Resource Unit (RU) allocation in mesh networks is provided via identifying devices engaged in wireless communication over a shared channel in a mesh network, the devices including a first Access Point (AP), a second AP in wireless communication with the first AP via a first backhaul connection, and a third AP in wireless communication with the first AP via a second backhaul connection; determining a first demand for bandwidth in the shared channel over the first backhaul connection and a second demand for bandwidth over the second backhaul connection; and assigning RUs to the first backhaul connection based on the first demand relative to a total bandwidth demand within the shared channel and to the second backhaul connection based on the second demand relative to the total bandwidth demand the shared channel, wherein the total bandwidth demand includes the first demand and the second demand.

In a mesh network, several devices share one channel and contend for access to the shared channel so that only one device transmits signals at any given time. This can lead to build-up of data in the buffers of the devices, especially in the devices that are given lower priority in contention or that receive data from multiple devices. Accordingly, various bottlenecks for traffic flow can develop at one or more Access Points (APs) in the mesh network, particularly as the size and the complexity of the mesh network grows.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially used in other embodiments without specific recitation.

Resource unit allocation in mesh networks


An integrated circuit (“IC”) assembly includes an IC die with a metallization layer on a top surface thereof. A plurality of lead wires are bonded at first end portions thereof to the metallization layer. A conductive layer is attached to the metallization layer and covers the first ends of the lead wires.

Semiconductor devices, to be useful, must be electrically connected to one another or to other electronic devices or to interconnect boards such as printed circuit boards and carrier boards. Leadframes made from conductive metal such as copper, silver or gold are often used to electrically connect the semiconductor device to other electronic devices. One popular and flexible method of connecting semiconductors devices to leadframes and/or other electronics is wire bonding. Bondwires usually consist of aluminum, copper or gold. Bond wire diameters typically range from about 15 μm to several hundred micrometers in high-power applications. There are two basic types of wire bonding—ball bonding and wedge bonding.
Ball bonding usually uses a combination of heat, pressure and ultrasonic energy. In ball bonding, a small molten ball is formed at the end of the bondwire by application of a high voltage charge through a tool holding and dispensing the wire known as a capillary. This ball is placed in contact with the electrical contact surface of a chip that is usually copper or aluminum. A combination of heat, pressure and ultrasonic energy is then applied which creates a weld between the ball and the metal surface that it contacts. The ball bond is sometimes referred to as the first bond because it is usually the first bond made in wire bonding of an IC chip/die to a leadframe.
In a die leadframe interconnection, the type of wire bond that is generally used to connect the second end of the bond wire to the leadframe is a called a wedge bond or sometimes second bond. It is formed by crushing the end of the bondwire between the leadframe or other metal surface and the tip of the capillary tool.
A leadframe often forms part of the electrical connection between a semiconductor device and other electronics. In some cases the die and bond wires connecting it to a leadframe are encapsulated within a hard protective shell that is typically formed by a molding operation. One or more surfaces of lead portions of the leadframe are not covered by the protective shell and may be electrically and mechanically connected to external circuits. The combination of an integrated circuit ("IC") die, leadframe, bond wires and encapsulating material is generally referred to as an integrated circuit package (IC package). There are various types of IC packages. The difference between IC packages is primarily determined by how the lead portions of the leadframe are exposed, the configuration and number of the exposed lead portions, how the package is mounted and the size or shape of the package. For example below is a list of so called "flat packages" that are commercially available:                Flatpack, early metal/ceramic case with flat leads        CFP: Ceramic Flat Pack        CQFP: ceramic quad flat-pack, similar to PQFP        BQFP: Bumpered Quad Flat Pack        DFN: Dual Flat Pack, No Lead
ETQFP: Exposed Thin Quad Flat Package
PQFN: power quad flat-pack, no-leads, with exposed die-pad[s] for heatsinking                PQFP: Plastic quad flat package        LQFP: Low-profile Quad Flat Package        QFN: Quad Flat No Leads, also called micro lead frame (MLF).        Quad Flat Package: (QFP)        MQFP—Metric Quad Flat Pack, a QFP with metric pin distribution        HVQFN: Heat-sink very-thin quad flat-pack no-leads        SIDEBRAZE        TQFP: Thin Quad Flat Pack        TQFN: Thin Quad Flat No-Lead        VQFB: Very-thin Quad Flat Pack
Even though IC packages are available in an assortment of types and sizes, certain features thereof such as, for example, wire bond connections between an IC die and a leadframe, have remained essentially the same from package to package.

This patent is subject to a terminal disclaimer.

Integrated circuit (“IC”) assembly includes an IC die with a top metallization layer and a conductive epoxy layer applied to the top metallization layer


A wireless device and system employs a two-dimensional (2-D) Trellis code that can be applied to Quadrature Phase Shift Keying (QPSK) and higher order Quadrature Amplitude Modulation (QAM) constellations. The Trellis codes employed have optimal Euclidean distance properties for QPSK constellations, and have very good Euclidean distance properties for higher-order QAM constellations. The Trellis codes are suited for transmission systems that adopt multi-mode QPSK and QAM constellations with different data rates since the same Trellis code can be applied to all modulation formats and the same decoder can be used at the receiver for all modulation formats. Modulation formats include QPSK, 8-QAM, 16-QAM, 32-QAM, and 64-QAM and may be extended to even higher order modulations formats.

1. Technical Field of the Invention
This invention relates generally to wireless communications; and more particularly to low power high data rate communications.
2. Description of Related Art
Communication technologies that link electronic devices are well known in the art. Some communication technologies link electronic devices via networks. Examples of such networks include wired computer networks, wireless computer networks, wired telephone networks, wireless telephone networks, and satellite communication networks, among other networks. Within such communication networks, a network infrastructure couples electronic devices to one another.
The need for wireless networking has been addressed by various standards bodies that promulgate interworking standards. One such standards body promulgated the IEEE 802.11 standard that defines a wireless LAN. In a typical 802.11 wireless LAN, a wired backbone couples to one or more wireless access points (WAPs) that wirelessly connect to many computers or other electronic devices that contain wireless interfaces. IEEE 802.11 networks have achieved significant success in servicing wireless communication needs for portable computers, portable data terminals, and other wireless devices that transmit and receive data. However, IEEE 802.11 networks lack high data rate and Quality of Service (QOS) features to support multimedia communications.
Wireless personal area networks "WPAN" enable short-range "ad-hoc" connectivity among portable consumer electronics and communications devices but do not require the infrastructure needed for an 802.11 network. The coverage area for a WPAN is generally within a 10-meter radius. The term "ad-hoc" connectivity refers to both the ability for a device to assume either master or slave functionality and the ease in which devices may join or leave an existing network.
The Bluetooth radio system has emerged as the first technology addressing WPAN applications with its salient features of low power consumption, small package size, and low cost. Raw data rates for Bluetooth devices are limited to 1 Mbps, although the actual throughput is about half of the raw data rate. A Bluetooth communication link supports up to three voice channels with very limited additional bandwidth for bursty data traffic. However, Bluetooth communication links cannot support the data transfer requirements of portable consumer electronics devices that transmit and receive multimedia data, e.g., high quality video applications, audio applications, and multi-megabyte file transfers for music and image files.
To support higher data rates in wireless systems, higher order modulations are often employed, e.g., 8-QAM, 16-QAM, 32-QAM, 64-QAM, 128-QAM, etc. However, higher order modulations are susceptible to fading and interference, particularly at the low transmission powers employed in WPAN applications. Thus, to provide flexibility in operation, multiple constellation sizes are typically supported within wireless systems of this type. Larger constellations are used for higher quality channels while smaller constellations are used for lower quality channels.
Forward Error Correction (FEC) is commonly included in wireless systems. The usually employed Reed Solomon block codes add non-information-carrying parity bytes to the transmitted data bytes. In the absence of errors FEC reduces the actual data throughput for a given channel bit rate. However, when errors occur, the capability of correcting errors up to a certain extent decreases the number of required retransmissions thereby increasing the effective data throughput.
While FEC schemes operate on hard-quantized bits and/or bytes, it is desirable to provide an "inner" coded modulation scheme that is more specifically designed to deal with non-binary modulation symbols and noisy received signals. Trellis Coded Modulation (TCM) is a commonly employed inner coding scheme. Further, because the quality of wireless channels changes over time, it is desirable to vary constellation sizes depending on channel conditions. In a WPAN system, for example, each wireless device must therefore support TCM with a plurality of constellation sizes. In order to minimize complexity, it is desirable to use one common TCM scheme for all constellation sizes. This scheme should provide optimal performance for each constellation, which means that for a given number of code states and a given constellation, no other scheme should exist with better performance than the common scheme. Well known TCM schemes are optimal for all types of Quadrature Amplitude Modulation (QAM), but not simultaneously also for Quadrature Phase Shift Keying (QPSK).

Optimal trellis code design for QPSK and higher order quadrature amplitude modulations


An ultrasonic actuator according to an embodiment of the present invention includes: a stator generating a rotational driving force in accordance with a driving signal having a train pulse, which is used, for example, an AF mechanism; and a rotor converting the rotational driving force into actual movement. In the thus-structured ultrasonic actuator of the present invention, the driving signal is obtained by removing a predetermined number of pulses from the pulse train upon deceleration, and the remaining number of consecutive pulses is set to at least 2 or 4 or more.

1. Field of the Invention
The present invention relates to an ultrasonic actuator used in an autofocus (AF) mechanism incorporated in, for example, an optical device, and to a driving method of the ultrasonic actuator.
2. Description of Related Art
Existing cameras such as a film camera and a digital camera incorporate a lens driver for automatically driving a lens, and various kinds of lens drivers have been hitherto developed. FIG. 1 shows a conventional lens driver using a stepping motor.
As shown in FIG. 1, a conventional lens driver 900 has a zoom mechanism adjusting a focal distance (zoom factor) and an autofocus mechanism automatically adjusting the focus of a lens. These mechanisms are provided with stepping motors 901 and 902, and gears 903 and 904 are mounted to motor shafts of the stepping motors 901 and 902 respectively. The lenses 905 and 906 as a zoom lens and an autofocus lens incorporate gear holders 907 and 908, and gears 903 and 904 are fitted in these gear holders. In the conventional lens driver 900, the motors 901 and 902 of the zoom mechanism and the autofocus mechanism are rotated to drive the lenses 905 and 906. The lenses 905 and 906 are axially supported to a lens holding shaft 909.
Recent compact terminals such as a cell phone or a mobile terminal are equipped with a camera. Hence, there arises a need to downsize the camera, and a size and position of a motor of the lens driver are important factors in size reduction. The conventional lens driver using the stepping motor requires a pair of expensive stepping motors for both of the zoom mechanism and the autofocus mechanism. In addition, there is a limitation on size reduction of the stepping motor itself. From the viewpoint of component arrangement as well, size reduction in actuator is limited. If the components are arranged with intent to reduce a size, the number of components for transmitting a torque from the stepping motor increases, and each mechanism is complicated. Thus, the conventional lens driver using a stepping motor has limitations in size reduction as well as costs high.
To that end, from the purpose of downsizing the lens driver, there has been developed a lens driver using an ultrasonic actuator, not a stepping motor (see Japanese Unexamined Patent Publication No. 2003-33054, Japanese Unexamined Patent Publication No. 2002-303775, and Japanese Unexamined Patent Publication No. 9-298890, for instance). For example, a lens driver as disclosed in Japanese Unexamined Patent Publication No. 2003-33054 drives one lens using a single ultrasonic actuator. In contrast, plural lenses may be also individually driven by plural ultrasonic actuators. In this case as well, a pair of ultrasonic actuators are provided to both of the zoom mechanism and the autofocus mechanism similar to the lens driver using a pair of stepping motors. A lens driver using plural ultrasonic actuators is more expensive than a lens driver using a single ultrasonic actuator, similar to the lens driver using plural stepping motors, and its structure is complicated, so there is a limitation on size reduction.
Here, the ultrasonic actuator is an actuator based on a novel operating principle, not based on an electromagnetic operation as the conventional principle of driving the motor, and is used in a camera lens driver and a medical microactuator. A driving power source of the ultrasonic motor is a piezoelectric vibrator. There are two types of piezoelectric vibrators: a resonant type and a nonresonant type. The resonant type piezoelectric vibrator is used for the ultrasonic actuator of the present invention. There have been known two types of resonant type piezoelectric vibrators: a standing wave type the vibration node of which is not moved, and a traveling wave type the vibration node and loop of which are moved at sound velocity. These two types are based on one-dimensional reciprocating vibrations of a vibrator the gravity center of which is fixed. In addition, there have been utilized a standing wave vibrator that makes a two-dimensional reciprocating motion along the circumference of the cylindrical vibrator the gravity center of which is fixed, based on bending vibrations. Among these, the standing wave makes a reciprocating motion, not moves in one direction. The traveling wave moves in one direction, and can be utilized as a driving force. However, existing traveling wave vibrators are structured such that one of the original positive and negative phases of a standing wave is removed into a traveling wave, so its generation efficiency is low.
On the other hand, the piezoelectric actuator is a revolving resonator that can generate a reciprocal rotational torque at a single-phase alternating voltage, and save vibrating power Q times higher than excitation power (Q is larger than 1,000) and hold the power with as high efficiency as 99.9% or more. The revolving resonator is a torque resonator that means a resonator where electrostriction revolves, in other words, an element called a piezoelectric actuator which generates a torque with the highest efficiency. This element is mistaken for a kind of traveling wave vibrator in some cases. Upon resonance, the vibration loop makes one rotation every cycle along the circumference in sync with an excitation voltage, while the vibration node is not in a vibrating medium and revolves together with the center of gravity of the vibrator. Since the node is not moved, it cannot be of course regarded as a traveling wave, nor a wavemotion. It is, so to speak, a vortex. The vortex is a two-dimensional torque generated through rotation in a combined mode of a circumferential rotation mode and radial rotation mode. If having a cylindrical shape, the resonator is a three-dimensional resonator where an axial rotation mode can be readily combined with these two modes, so three-dimensional mode rotation occurs, and three-dimensional torque of various directions is generated on the entire surface of the piezoelectric actuator, as disclosed in the publication below. The revolving torque is generated with an asymmetric mode for applying voltages of opposite polarities between opposing electrodes A and C and between opposing electrodes B and D. As a result, the gravity center revolves around its center, and the outer circumference of a circle is eccentrically moves like a hula hoop. Then, the piezoelectric actuator moves on spiral trajectories. In this way, the revolving torque is generated.
Japanese Unexamined Patent Publication No. 2002-303775 discloses a structural example of the ultrasonic motor. FIG. 2 is a schematic perspective view of the ultrasonic motor as disclosed in Japanese Unexamined Patent Publication No. 2002-303775. The ultrasonic motor includes a cylindrical piezoelectric ceramic stator 11 and a ring-shaped rotor 12 that is brought into close contact with a rear edge of the stator. Four divided electrodes, electrodes 111, 112, 113, and 114, are formed on the outer peripheral surface of the cylindrical stator 11, and a common electrode (not shown) is formed throughout the inner peripheral surface.
As shown in a schematic diagram of FIG. 3A, alternating driving signals A, B, C, and D that are out of phase are applied to the electrodes 111, 112, 113, and 114. Further, the inner-peripheral-surface electrode of the cylindrical stator 11 is kept at a floating or ground potential (midpoint potential) As shown in FIGS. 3A and 3B, there is a phase shift of 90 degrees between the driving signals A and B, B and C, C and D, and D and A. Accordingly, there is a phase shift of 180 degrees between the driving signal A and the driving signal C and between the driving signal B and the driving signal D. If excited with the voltage asymmetrical with respect to the axis of the cylinder, every portion of the piezoelectric element would expand and contract in accordance with a corresponding voltage level. However, circumferential force acts in adjacent portions, resulting in occurrence of rotation in a combined mode of a radial rotation mode and a circumferential rotation mode. This causes spiral movement. If such spiral movement occurs, resonant phenomenon that the center of gravity moves around its center occurs, and the turning radius is resonance-amplified. In this way, the piezoelectric actuator can directly excite rotation, and strong revolving torque is uniformly generated in the peripheral surface. As for a cylindrical stator, a torque is generated throughout the entire surface, and strong revolving torque perpendicular to the diameter is generated especially at the end surface. The rotational torque can be directly turned into the rotational force of the rotor 12 that is brought into pressure contact with the stator 11.
Referring now to a graph of FIG. 5, a relation between a load current and a drive frequency in an example of the conventional ultrasonic motor is described. If a frequency is decreased from a rotation stop point higher than a resonance frequency of the piezoelectric actuator (piezoelectric element) of the stator 11, the load current is maximized at a predetermined frequency. At this time, the largest torque is obtained. If the frequency is a little lowered from the frequency where the load current is maximized, the ultrasonic motor reaches a resonance step-out point, with the result that the load current abruptly decreases to stop the rotation. Next, in the case of increasing the frequency from the step-out point up to a resonance demodulation point, the load current abruptly increases to resume the rotation. If further increased, the frequency reaches a stop point. It is a feature of non-linear resonance that the step-out point and the demodulation point are not at the same frequency level, the history of change is obtained through frequency sweep, and a current jump phenomenon occurs.
To elaborate, as shown in FIG. 6, in the case of increasing a frequency from a lower level, the ultrasonic motor is kept at rest at a frequency lower than the resonance frequency (recovery frequency). The ultrasonic motor rotates if the frequency exceeds the recovery frequency. The ultrasonic motor stops rotating if the frequency reaches the rotation stop point. In contrast, in the case of decreasing the frequency from a higher level, the ultrasonic motor does not stop rotation even at the frequency beyond the recovery frequency, and stops at the step-out point.
To that end, a resonance frequency of the piezoelectric actuator and a current amount are measured beforehand, and an appropriate driving signal is input to the piezoelectric actuator based on the data. As shown in FIG. 7, operating characteristics of the ultrasonic motor are such that the resonance frequency f0 is shifted to the frequency f1 or f2 due to various factors such as heat generated upon motor driving. Therefore, an amount of current flowing through the piezoelectric actuator at a predetermined frequency is changed, so even if driving signals of constant frequency are input all the time, it is difficult to keep a stationary state. To overcome this problem, reported is a method of feeding back a drive current from the ultrasonic motor, controlling a frequency of the driving signal to an appropriate level, and keeping the maximum current (peak current) (see Japanese Unexamined Patent Publication No. 2002-359988, for instance).
Further, even if a feed-back control on a frequency of the driving signal is executed, the ultrasonic motor has nonlinear characteristics, so there is a fear that the frequency reaches the step-out point to stop the motor rotation. Thus, the ultrasonic motor can be driven while kept in a stable state for a certain amount of time but can be hardly driven while kept in a stable state for a long period. Further, a resonance frequency slightly varies among piezoelectric actuators, so it is difficult to set a single resonance frequency that enables stable operations of many piezoelectric actuators. Furthermore, the piezoelectric actuator has hysteresis characteristic. Therefore, if the same piezoelectric actuators are used, the resonance frequency is changed.
As described above, a frequency history band from the step-out point to the demodulation point is an unstable range as shown in FIG. 5, and is inappropriate as a drive area. A frequency band from the demodulation point to the stop point is appropriate for driving. The frequency history band is unique to a nonlinear resonator in which as resonance amplitude increases to some degrees, saturation phenomenon suddenly occurs, Q drops, and a heat loss occurs. Therefore, the bandwidth varies depending on a frequency sweep speed. On the other hand, the demodulation point is a frequency where the ultrasonic motor returns from a non-oscillation state, that is, a non-heat-generating state to a resonant state, so stable frequency measurement values can be easily obtained. In practice, if the ultrasonic motor is excited to keep a resonant state with a constant frequency around the demodulation point, the resonance frequency is shifted to a higher band due to heat generation, and an exciting frequency is shifted to a history band lower than the demodulation frequency. Finally, the loss of synchronism occurs, and heat generation is stopped. If the ultrasonic actuator is held in this state for a predetermined period, the demodulation frequency corresponds to the exciting frequency due to temperature drop resulting from heat radiation. Then, the ultrasonic actuator jumps to the resonant state. If the exciting frequency is adjusted, a frequency where a jump to the loss of synchronism/demodulation is repeated at regular intervals is found. This frequency is a lower limit of a stable drive area, and a band from the lower limit to the stop point is the stable drive area.
The thus-structured ultrasonic motor has a function of a high-definition stepping motor. In order to obtain various actuators using this motor, it is necessary to lower the motor rpm, that is, decelerate the motor without impairing the high mobility. As conceivable measures for reducing the motor rpm, there is a method of reducing the rpm using a gear or the like in a motor mechanism. However, this method involves a fear that the high mobility is impaired, and the size is increased because of its structure. In particular, this method is insufficient for an application that requires size reduction and high definition, such as an AF actuator.
Further, as conceivable methods of electrically reducing the motor rpm, there is a method of changing the driving signal. However, nonlinearity is high, so a linear response cannot be expected, and controllability is low. For reducing the rpm under constant voltage conditions, there is a method of shifting a driving signal frequency to a lower level in a drive frequency range. This method shifts a frequency to a higher level to reduce a vibration energy generated in the piezoelectric element to reduce an energy transmitted to the rotor to thereby reduce the motor rpm, and thus involves a problem in that a drive torque as well as the rpm reduces along with the reduction in transmitted energy, and it is impossible to change only the rpm under constant output torque conditions.

Ultrasonic actuator, driving method of the ultrasonic actuator, lens driver, and portable device


To improve a depletion transistor provided between a control terminal of an output transistor and an output terminal coupled to a load not to enter a conductive state when the output transistor is in the conductive state. The output transistor is served as a source follower. Control voltages which controlling the conductive state/nonconductive state of the depletion transistor are supplied to both a control terminal (gate) and a substrate terminal (back gate) of the depletion transistor.

1. Field of the Invention
The present invention relates to a semiconductor output circuit, and more particularly, to a semiconductor output circuit which controls power supply to a load.
2. Description of the Related Art
As a semiconductor output circuit using a source follower output transistor for supplying power to a load, for example, there is a circuit disclosed in Japanese Unexamined Patent Application Publication No. Hei 06-188710, which is equivalent to U.S. Pat. No. 5,352,932 (hereinafter, referred to as Tihanyi). The above-mentioned semiconductor output circuit is basically structured by coupling as a source follower an output transistor between a power supply line and an output terminal being coupled with a load, and controlling a conductive state/nonconductive state of the output transistor to control power supply to the load.
In particular, the output transistor is shifted from the conductive state to the nonconductive state by coupling a depletion transistor between the gate and the source of the output transistor.
However, the inventor has noticed the following problem inherent in the output transistor. In the output circuit disclosed in Tihanyi, the source and the substrate terminal (back gate) of the depletion transistor are commonly coupled. In the case where the output transistor is in the conductive state, the depletion transistor is required to be in the nonconductive state, but in some cases, is in the conductive state.
In other words, when the output transistor is in the conductive state, the gate of the depletion transistor is supplied with a ground potential, whereas a source potential of the output transistor, which is nearly equal to a power supply potential, appears on the source thereof. As a result, the voltage applied between the gate and the source of the depletion transistor is in the state exceeding a so-called cut-off voltage, and accordingly, the depletion transistor enters the nonconductive state.
In the output circuit disclosed in Tihanyi, because the conductive state/nonconductive state of the depletion transistor is controlled using the power supply voltage (for example, battery voltage), a device having a higher breakdown voltage is required. A drain current (leak current) with respect to the voltage applied between the gate and the source is compared between a depletion transistor having a higher breakdown voltage and a depletion transistor having a lower breakdown voltage. As a result, it is revealed that in the depletion transistor having a higher breakdown voltage, compared with the depletion transistor having a lower breakdown voltage, the drain current (leak current) hovers at high level in the state of having a value larger by one digit or more (does not drop) and is not completely cut off (does not enter the nonconductive state) even when the voltage applied between the gate and the source is reduced.


A steam cooking system for cooking foods such as a light Chinese dish called as dim sum with steam comprises a steam generator disposed outside a guestroom of a restaurant, a cooking chamber formed adjacent to each of tables in the guestroom, and a steam line extending from the steam generator to at least one steam outlet formed in a bottom of the cooking chamber. A valve is provided in the steam line at the vicinity of the steam outlet to be switchable between an open position of supplying steam into the cooking chamber and a close position of stopping the supply of steam. A control unit controls the valve to keep the valve at the open position for a cooking time period determined according to a menu to be cooked with steam. An exhausting unit is formed at a top of the cooking chamber to exhaust used steam from the cooking chamber to the outside of the guestroom. In this system, guests can enjoy the steam cooking operation at the guest's table by themselves and tasting the steam-cooked foods at an optimum tasting temperature.

1. Field of the Invention
The present invention relates to a steam cooking system for restaurant, which can be used to cook foods such as a light Chinese dish called as dim sum with steam, and particularly is characterized in that guests can carry out a steam cooking at the guest's table in the restaurant to enjoy the steam cooking by themselves and tasting the steamed foods.
2. Disclosure of the Prior Art
In Chinese restaurants of the past, when guests order a light meal, e.g., dim sum, the dim sum placed in a set of baskets is cooked with steam at a kitchen separated from a guestroom and then waitress or waiter carries the steamed dim sum to the guest's table in the guestroom.
However, when the kitchen is sufficiently spaced from the guest's table, the baskets having the steamed dim sum therein will get cold during a carrying time period of the baskets from the kitchen to the table. For example, the baskets will get cold to such a degree that the waitress can handle the baskets at the table without burn. As a result, the decrease of the basket temperature may bring a deviation from an optimum tasting temperature of the steamed dim sum.


In one embodiment, a semiconductor memory cell (10) having a trench (24) and access transistor (54) formed in a well region (20). The trench (24) substantially contains an inverter (60) which is electrically coupled to ground and power signals by buried layers (12, 18) in the substrate (11). The inverter (60) has a toroidal, shared-gate electrode (40) which electrically controls a driver transistor (32) in the wall (26) of the trench (24), and a thin-film load transistor (42) in the central portion of the trench (24). A portion of the toroidal, shared gate electrode extends to an adjacent well region (20') and contacts well region (20') at cell node (13'). A ground signal is provided to load transistor (42) at the bottom surface (28) of the trench (42). A supply signal is provided by a buried layer (18) which is integral with driver transistor (32).

As semiconductor devices become smaller, it becomes necessary to arrange individual components within a device such that minimal separation distances are achieved. The need to design compact component arrangements occurs most significantly in memory devices. Because of the large number of components needed to fabricate a typical dynamic-random-access-memory device (DRAM), or static-random-access-memory device (SRAM), the components must be arranged compactly if the overall device dimensions are not to become excessively large. This problem is especially critical in SRAM devices where a typical individual memory cell contains as many as six separate components.
One technique for reducing memory cell dimensions is to place a number of the components in a trench structure, which is sunk into the substrate. Components, such as resistors, capacitors, transistors, and the like, are packed into the trench leaving the remaining active surface area of the cell available for the formation of additional memory cell components. However, as memory devices continue to become more and more complex, there is a need to further reduce the size of the trench itself. This is necessary to allow the placement of even more memory cells in a given area of substrate surface. Because components such as transistors have a certain minimum number of functional components, i.e. a gate electrode, a source and drain region, and the like, new design techniques are needed to pack these components into an even smaller trench.
Even with careful component design and the integration of a trench structure into the memory cell, additional surface area is still necessary for remaining components. For example, active surface regions of the cell must be made available for the interconnection of leads providing supply and ground voltages to the cell. Simple down-sizing of interconnect components can only be pursued to the limit of the line-width definition capability of the manufacturing process. Once the line-width definition limits are reached, new design methodology must be employed if further reduction in memory cell area is to be achieved. Accordingly, a need existed for a new cell design which maximizes the utilization of available space inside the trench, and further reduces the amount of active surface area necessary for the formation of a ULSI semiconductor memory device.

Semiconductor memory cell having a trench structure


Disclosed is a vacuum breaker having further enhanced reliability. The vacuum breaker comprises: a main body having a water inlet (26, 41), a water outlet (34, 48), a water passage (30, 44) for fluidically connecting the water inlet and the water outlet, and a first ambient-air intake port (36, 50) and a second ambient-air intake port (37, 49) for allowing the water passage to fluidically communicate with ambient air therethrough; a first valve element (28, 42); and a second valve element (32, 46) disposed downstream of the first valve element. The first valve element is designed to be movable between a first position allowing the water inlet to fluidically communicate with a zone of the water passage between the first and second valve elements, when water is permitted to pass through the water passage, and a second position allowing the first ambient-air intake port to fluidically communicate with the zone of the water passage between the first and second valve elements, when water is inhibited from passing through the water passage. The second valve element is designed to be movable between a first position allowing the zone of the water passage between the first and second valve elements to fluidically communicate with the water outlet, when water is permitted to pass through the water passage, and a second position allowing the second ambient-air intake port to fluidically communicate with the water outlet, when water is inhibited from passing through the water passage.

Recent years, a water closet of a type designed to be fluidically connected directly to a water system, such as a city water line, and fed with flushing water directly from the water system has come into wide use. In this type of water closet, a water system and a line for supplying flushing water to a bowl are in direct fluid communication with one another through a water-feed valve. Therefore, there is a conceivable risk that a negative pressure generated in the water system from some cause, such as cut-off of water, causes a backflow of flushing water from the water closet to the water system. In order to avoid such a risk, this type of water closet is equipped with a vacuum beaker for eliminating the backflow. Japanese Patent Laid-Open Publication No. 2001-182122 discloses a flushing-water feed device provided with a vacuum breaker disposed on a downstream side of a water-feed valve so as to eliminate such a backflow. This vacuum breaker is operable, when water is permitted to pass through the water-feed valve (in a flow state), to provide fluid communication between the water-feed valve and a flushing-water supply line to a water closet, and, when water is inhibited from passing through the water-feed valve (in a non-flow state), to open the flushing-water supply line to ambient air. In the water closet equipped with this vacuum breaker, the flushing-water supply line is opened to ambient air in the non-flow state, and, in the event that a negative pressure is generated in the water system, the ambient air is taken into the water system to eliminate the risk of backflow of flushing water from the supply line to the water system.
Patent Publication 1: Japanese Patent Laid-Open Publication No. 2001-182122

Vacuum breaker, and water-feed valve assembly and water closet provided therewith


The invention discloses an herbal extract of treating liver cancer, wherein a method of producing the herbal extract comprising the steps of: blending Antrodia cinnamomea, Rhinacanthus nasutus and Phellinus linteus and obtaining a mixture, wherein the weight percentages of Antrodia cinnamomea, Rhinacanthus nasutus and Phellinus linteus are 33.4 to 60%, 20 to 33.4% and 20 to 33.4% by weight of the mixture, respectively; soaking the mixture with a 95% ethanol solution with a weight-volume percentage being 50%, followed by extracting at 50 to 80° C.; and concentrating the extracted product to obtain the herbal extract. The invention also discloses a method of treating liver cancer.

1. Field of the Invention
The present invention generally relates to an herbal extract and, more particularly, to an herbal extract extracting from a mixture containing Antrodia cinnamomea, Rhinacanthus nasutus and Phellinus linteus. The present invention further relates to a method of treating liver cancer.
2. Description of the Related Art
According to Health Promotion Administration, Ministry of Health and Welfare in Taiwan, liver cancer is the second leading causes of cancer death in Taiwan and a total of 7,000 deaths are reported every year. The major reason is the prevalence of chronic hepatitis B and hepatitis C, which eventually causes cirrhosis or liver cancer.
Conventional treatment of liver cancer includes surgical resection and liver transplantation. Moreover, patients without qualification for a liver transplant have to choose an alternative treatment, such as radiofrequency ablation. However, radiofrequency ablation is a high cost treatment, has a higher possibility of causing complication, and is only suitable for small tumors (<2 cm).
Antrodia cinnamomea, a fungus indigenous to Taiwan, grows on decayed Cinnamomum kanehirai. Antrodia cinnamomea is rich in active ingredients such as triterpenes and superoxide dismutases and commonly used for liver protection.
Antrodia cinnamomea belongs to herbs with cold property and shows effect on removing free radicals and mitigating inflammation. However, a long-term application of Antrodia cinnamomea may excessively remove free radicals, resulting in a cold constitution with reduced immunity.
Rhinacanthus nasutus shows effects on reliving internal heat production and detoxication. Phellinus linteus contains polysaccharides as major active ingredients, which is capable of activating immunity system and improving immunity.
In light of this, it is necessary to provide an herbal extract and a method of treating liver cancer.

Herbal extract and a method of treating liver cancer


A method and an apparatus for driving a sensorless DC motor having a bridge-type inductance detecting circuit. The method of driving a sensorless DC motor including a rotor having Y-winding phase coils and a plurality of magnetic poles comprises the steps of applying an alternating current voltage signal to bridge circuits coupled to the phase coils, respectively, inputting an output voltage signal of each bridge circuit as an inductance detecting signal of each phase coil, amplifying the inputted inductance detecting signal of each phase coil, comparing a value of the amplified inductance detecting signal of each phase coil to each other, and determining an initial position of the rotor for rotating the rotor, the phase coils except for a phase coil having a maximum inductance detecting signal being magnetized at the initial position. By the method, the initial position of the rotor can be precisely detected even when the rotor is rotated at a low speed or in a stop state, so the motor is reliably driven.

1. Field of the Invention
The present invention relates to a method and an apparatus for driving a sensorless DC motor having a bridge-type inductance detecting circuit, and more particularly, to a method and an apparatus for driving a sensorless DC motor having a bridge-type inductance detecting circuit which detects an inductance based on a relative position of a phase-coil with respect to a magnetic rotor thereby determining a rotor position.
2. Description of the Prior Art
A video cassette recorder (VCR) includes a capstan motor and a head drum motor. Conventionally, in order to drive those motors, it is required to determine the rotor position by using sensors such as a HALL sensor or an optical sensor in such a manner that a phase curve applied to motors can be controlled according to the rotor position. However, the conventional method requires a space for installing sensors. In addition, the sensors are so expensive that the cost of an article is increased.
Recently, a sensorless motor has become widely used for overcoming the above problems.
In the conventional sensorless motor, as disclosed in U.S. Pat. No. 5,235,264, a rotor's commutation is determined by detecting a back electromotive force (BEMF) induced into the phase coil thereby determining the magnetic rotor's position.
The back electromotive force induced into the coil is in proportion to a rotational velocity of the rotor. Therefore, if the rotor is rotated at a lower speed or in a stop-state, detecting the back electromotive force is very difficult. Accordingly, the method using the back electromotive force requires the rotor to rotate over a predetermined speed so as to sufficiently detect the back electromotive force, otherwise, the commutation of the rotor is unstably controlled.

Method and apparatus for driving a sensorless DC motor having a bridge-type inductance detecting circuit


This invention relates to a light guide lens adapted for guiding light emitted from a light emitting element. The light guide lens includes a base portion disposed on a light axis (L) and including a light incident surface, and a light guide portion surrounding the light axis (L) and disposed on the periphery of the base portion. The light guide portion includes an inner peripheral edge connected to the base portion, an outer peripheral edge opposite to the inner peripheral edge, and at least one light control unit connecting the inner and outer peripheral edges and having first and second light guide sections so as to form a varied light pattern.

1. Field of the Invention
The invention relates to a lens, more particularly to a light guide lens adapted for guiding light emitted from a light emitting element.
2. Description of the Related Art
in recent years, a light emitting diode (LED) serving as a light source is popularly used in a vehicular light. Light emitted from the LED is primarily guided by a light guide lens to direct outward. A structural design of the light guide lens determines distribution of a light pattern. Referring to FIG. 1, U.S. Pat. No. 7,270,454 B2 discloses a conventional vehicular lamp that includes a light emitting member 11 and a bowl-shaped lens 12. The lens 12 includes a direct light control unit 121, and a reflected light control, unit 122 surrounding the direct light control unit 121. The reflected light control unit 122 has an uneven front surface 123 and an uneven rear surface 124 opposite to the uneven front surface 123 so that the bowl-shaped configuration of the lens 12 is composed of a plurality of rings that are interleaved with each other. The rings have irregular sections and different sectional dimensions. As a result, the light emitted from the light-emitting member 11 toward the direct light control unit 121 tends to directly pass through the direct light control unit 121 and exit therefrom. The light emitted from the light emitting member 11 toward the reflected light control unit 122 tends to be reflected by the rear surface 124 toward the uneven front surface 123. The optical projection pattern produced by this disclosure includes a plurality of annular bright stripes and annular dim stripes interleaved with each other.
Aside from vehicular lamps, other illumination devices, such as lighting devices, signal light devices, decorative lighting devices, advertising light boxes, etc., used either indoor or outdoor also require a light guide lens to complement a light emitting device for emphasizing the profile of the illumination device. In order to meet the diverse needs of customers, a light guide lens with an innovative structure with, a distinct light guide function is provided.


The invention pertains to novel insecticidal compounds derived from Bacillus thuringiensis strains. Nucleotide sequences encoding a Cry2Ae protein and truncated fragments thereof are provided. Further provided are recombinant hosts expressing such proteins, particularly plant cells, plants and seeds and methods of using the recombinant hosts for controlling insects, particularly Lepidoptera.

(i) Field of the Invention
The present invention relates to new nucleic acid sequences, particularly DNA sequences, encoding insecticidal proteins produced by Bacillus thuringiensis strains. Particularly, new nucleic acid sequences, particularly DNA sequences encoding proteins designated as Cry2Ae, Cry2Af and Cry2Ag are provided which are useful to protect plants from insect damage. Also included herein are micro-organisms and plants transformed with a nucleic acid sequence, particularly a DNA sequence, encoding at least one of the newly isolated Cry2A proteins.
(ii) Description of Related Art
Bacillus thuringiensis (abbreviated herein as "Bt") is well known for its specific toxicity to insect pests, and has been used since almost a century to control insect pests of plants. In more recent years, transgenic plants expressing Bt proteins were made which were found to successfully control insect damage on plants (e.g., Vaeck et al., 1987, Jansens et al., 1997).
Despite the isolation of quite a number of insecticidal Bt genes, the search for new genes encoding insecticidal proteins continues. Indeed, insecticidal Bt proteins are known to have a relatively narrow target insect range compared to chemical insecticides. Also, having multiple toxins to the same target insect species allows the use of proteins having different modes of action so that insect resistance development can be prevented or delayed. And, insecticidal Bt proteins with different amino acid sequences have different levels of insecticidal efficacy against specific insects, making it desirable to have several different insecticidal proteins available in order to be able to control the relevant insect pests of different crop plants.
Previously, several types of Cry2A-proteins were identified (see Crickmore et al., 1998, incorporated herein by reference).
The new Cry2Ae protein of this invention has the highest amino acid sequence identity to the Cry2Aa1 protein (Donovan et al., GenBank accession number M31738), but still differs in about 9 percent of its amino acid sequence.
The closest sequence identity to the Cry2Af protein was found in the Cry2Ab1 protein (Widner and Whiteley, GenBank accession number M23724), but both proteins still differ in about 5 percent of their amino acid sequence.
The closest sequence identity to the Cry2Ag protein was found in the Cry2Ac1 protein (Wu et al., GenBank accession number X57252), but both proteins still differ in about 20 percent of their amino acid sequence.
Further known Cry2A proteins include the Cry2Ad1 protein (Choi et al., 1999), and other Cry2Aa, Cry2Ab, and Cry2Ac proteins (Crickmore et al., 1998). Cry2A-like proteins and DNA sequences encoding them are also shown in U.S. Pat. No. 5,338,544, in published PCT patent application WO 00/26371 and in published PCT patent application WO 98/40490.
Expression of Cry2A-type proteins in plants has been described, e.g., in Kota et al. (1999) and in published PCT patent application WO 00/26371.


A monitor with a large screen is provided at the back of the camera. In the recording mode, a preview image or a captured image is displayed in a part of the monitor where there is little possibility of being covered by the hand of the operator. In the reproducing mode, a reproduced image is displayed on substantially the entire screen of the monitor. A touch panel is provided over the monitor, and operation buttons such as a zoom operation button and an exposure correcting button are displayed on a part of the monitor where no image is displayed in the recording mode. Therefore, the part of the monitor can also be used as a camera operational part.

1. Field of the Invention
This invention relates generally to a camera with a monitor, and more particularly to a camera with a monitor, which is applicable to an electronic camera that is provided with a thin monitor such as a liquid crystal display.
2. Description of Related Art
Some electronic cameras such as a digital camera are provided with a monitor such as a liquid crystal display (LCD) at the back thereof, which shows a preview image, which is a captured image before recording, and a recorded image thereon. A wide variety of electronic cameras have been developed: for example, an electronic still camera that can function as a cellular phone (Japanese Patent Provisional Publication No. 9-37129) and an electronic camera that can function as an electronic datebook (Japanese Patent Provisional Publication No. 7-23259). These cameras are also provided with the LCD monitor.
The electronic cameras have quickly become smaller, but at the same time, a larger LCD monitor has become desirable in order to show an image dynamic or having punch thereon.
If the LCD monitor has a large screen covering a large part of the camera, it is necessary to reduce the size of a grip, which is held by a hand of an operator of the camera. Thus, it is difficult for the operator to hold the camera. If the hand holding the camera covers the screen of the LCD monitor, it is impossible to see the entire image.


The present invention provides a carbon composite material diminished in anisotropy and comprising a carbon film and a resin, a forming material comprising the carbon film and the resin for producing the composite material, and a process for producing the carbon film.

Carbon fibers, which are lightweight and have properties such as high strength and high elastic modulus, have heretofore been used in carbon fiber-reinforced plastics. Already known as such carbon fiber-reinforced plastics are carbon composite materials which comprise carbon fibers arranged in unidirection and embedded in a matrix resin, for example, in a thermosetting resin or thermoplastic resin. These composite materials have a high strength axially of the carbon fibers. However, the strength (.sigma.T) in a direction orthogonal to the axial direction of the carbon fibers is dependent largely on the bond strength between the carbon fibers and the matrix resin, and is small and therefore differs greatly from the axial strength (.sigma.L), hence there is the problem that the material is great in so-called anisotropy (i.e., .sigma.L/.sigma.T). In other words, the composite material has a very high strength in the direction of the orientation of the fibers but has a relatively considerably low strength transverse to the orientation of the fibers. Accordingly, attempts have been made to diminish the anisotropy. For example, so-called unidirectionally reinforced sheets wherein fibers are arranged in parallel in one direction are superposed at varying angles to give an improved strength in a direction perpendicular to the orientation of fibers, or a fabric of carbon fibers is used to afford an improved strength in the direction perpendicular to the orientation of the fibers.
Further more, if the carbon fiber content in the above carbon composite material is adjusted to 70 vol. % or more in an attempt to impart a more improved strength to the material, voids will occur, resulting in a still lower strength in the direction orthogonal to the axes of the carbon fibers and eventually impairing the overall strength of the composite material. It is therefore difficult in the conventional carbon composite material to increase the proportion of carbon fibers for improving the strength, and to diminish anisotropy.
Accordingly, an object of the present invention is to provide a carbon composite material which is low in resin content and which nevertheless has a high mechanical strength and diminished anisotropy.
Another object of the invention is to provide a forming material for giving a carbon composite material which has such excellent characteristics and which is less likely to have voids and excellent in uniformity even when having a low resin content.

Carbon composite material incorporating carbon film, forming material and process for producing the carbon film