A method is described for decreasing bleed from an organic-based formulation comprising incorporating in the organic-based formulation an anti-bleed composition having (a) a monomer end-to-end distance of less than 12.2 angstroms or greater than 12.6 angstroms; (b) a ratio of formula weight to number of heavy atom bonds of 13 to 16 grams; (c) a ratio of formula weight to end-to-end distance of 18 to 22 grams/angstrom; (d) a ratio of heavy atoms to heavy atom bonds of 1 to 1.1; (e) a ratio of weight fraction of carbon to formula weight of 0.7 to 0.95; (f) a ratio of formula weight to number of carbon to carbon bonds of 14 to 20 grams; and/or (g) 1 to 2 heteroatoms.. Also described as an organic-based formulation is disclosed that comprises a filler, a resin and an organic-based formulation an anti-bleed composition having (a) a monomer end-to-end distance of less than 12.2 angstroms or greater than 12.6 angstroms; (b) a ratio of formula weight to number of heavy atom bonds of 13 to 16 grams; (c) a ratio of formula weight to end-to-end distance of 18 to 22 grams/angstrom; (d) a ratio of heavy atoms to heavy atom bonds of 1 to 1.1; (e) a ratio of weight fraction of carbon to formula weight of 0.7 to 0.95; (f) a ratio of formula weight to number of carbon to carbon bonds of 14 to 20 grams; and/or (g) 1 to 2 heteroatoms.

The present invention relates to reducing "bleed" from organic-based formulations and materials useful in semiconductor assemblies. More particularly, the present invention relates to reducing resin bleed from organic-based materials such as die attach adhesives used to bond semiconductor devices to a substrate, including such materials as used in connection with PC boards, multi-chip modules, and in controlled collapse bump technology. The present invention encompasses compounds that reduce bleed when added to organic-based formulations as well as a method for determining such compounds.
Organic-based materials, such as die attach polymeric materials, have gained increasing popularity, in part for their ability to accommodate larger die sizes and to facilitate processing at lower temperatures. However, problems with bonded semiconductor devices resulting from "bleedout", also referred to as "bleed" or "resin bleed", or separation of the resin vehicle from the polymer adhesive, sometimes occur from the monomer as well as any other small molecule present. Such problems are discussed in detail in an article entitled "An Experimental Study of Die Attach Polymer Bleedout in Ceramic Packages" by Michael R. Marks, et al., which was published in Thin Solid Films, vol. 252, p. 54-60 in 1994. As indicated in the article, in severe bleedout conditions, the resin wets the entire substrate to which the die is to be attached and may succeed in "wicking up" the ceramic sidewalls and contaminate wire bonding metalization. This may result in weak wire bondings by virtue of acting as an interdiffusional barrier at the joints. Consequently, producers of the packages typically desire little or no bleed, or controlled bleed with tight tolerances.
The article by Marks et al. suggests two methods to eliminate bleedout: surface energy reduction of the gold plating (on the substrate) and improvement in the cohesiveness of the polymer die attach material. The author suggests that bleedout may be eliminated by increasing the cohesiveness of the polymer matrix by increasing the intermolecular attractive energy through the presence of functional groups with high dipole moments in high concentrations. In particular, Marks et al. suggest that phenol-cured epoxy, polyamide and polycyanate were found to have good bleedout resistance, which was attributed to high dipole moments of epoxide and hydroxyl in phenol-cured epoxy.
Die attach adhesive formulations that may be rapidly cured have been disclosed in Nguyen, U.S. Pat. No. 5,150,195, issued Sep. 22, 1992, and Nguyen, U.S. Pat. No. 5,155,066, issued Oct. 13, 1992, the disclosures of which are expressly incorporated herein by reference. Rapidly curable adhesive formulations such as those disclosed in the aforementioned patents may contain a cyanate ester vehicle, curing catalysts such as alkylphenols, metal curing catalysts such as metal chelates, and fillers, which may be electrically and/or thermally conductive. Such cyanate ester-containing formulations are capable of being fully cured in less than five minutes at 200.degree. C., and often in about two minutes, or less, at 200.degree. C.
However, in addition to rapid curability, it is important for a die attach adhesive formulation to minimize bleed or "flash-off." These terms describe the excessive spreading of a resin on an attached substrate during curing, and in the case of a cyanate ester formulation, flashing-off of the monomer, which may result in the monomer being redeposited in the vicinity of the bonded area. The problems of bleed and flash-off are of special concern in continuous in-line fast-curing processes, i.e., continuous processes for the production of bonded semiconductor assemblies.
Theoretically, bleed is a predictable event using the spreading equation described by Marangoni in Tipographia dei fatelli Fusi, Pavia in 1865 and by W. F. Cooper and W. H. Nuttal in the Journal of Agricultural Sciences Vol. 7, p. 219 in 1915. Such equations predict that if the combined liquid and interfacial energies are higher than that of the substrate, spreading will not occur. However, in order to predict spreading, the surface energies of the liquid, the solid and the interface must be known.
As a practical matter, these quantities are difficult and time consuming to measure. Therefore, using energy effects as a predictive tool is burdensome, requiring extensive testing and calculation.
The present invention provides a method to reduce bleed or bleedout of the organic-based formulations used, for example, in semi-conductor devices, and to novel formulations exhibiting reduced resin bleed as well as a method of selecting compounds that may be added to such polymeric materials to reduce bleed.

Method of decreasing bleed from organic-based formulations and anti-bleed compostitions


Microporous membranes having supporting structures are disclosed. A microporous filtration membrane made of a polymeric material has an integral support, both the support and the membrane having substantially identical chemical composition. Preferred supported membranes of the present invention are made of polyvinylidene fluoride. At least part of the support is bonded to the surrounding microporous membrane to provide rigidity and chemical inertness. Methods of forming the supported microporous membranes are described, including a method that results in microporous membranes having unique structural and functional characteristics.

Conventional microporous membranes made from polymers (e.g. polycarbonate, polysulfones and polyvinylidene fluoride) are used to filter a wide variety of liquids and gases. Many polymeric membranes by themselves, however, have relatively poor mechanical properties. These membranes are fairly weak and may not maintain their integrity under normal handling. They will stretch when pulled and will shrink upon heating. They are also sensitive to folding and may crack at pleats that develop when folded. Furthermore, the mechanical assembly of unsupported polymeric membranes in devices frequently requires a thermoplastic component in order to seal the membrane at a seam or cap.
Where polymeric membranes are, however, structurally supported, the membranes typically are formed with an external, disposable mesh. This adds cost to the entire process and requires the additional step of removing the used membrane from the disposable mesh.
Another type of support is one in which a non-disposable, external support such as a polypropylene scrim or grid is laminated to the membrane.
Polymeric membranes are also made with internal supporting systems. In one membrane of this type, a nonwoven grid is incorporated into the polymer internally as the polymeric membrane is made. The grid and membrane are made of different materials. Nevertheless, polymeric membranes with internal supporting systems made of different materials can overcome only some of the problems associated with unsupported membranes. A serious problem encountered during production and use of supported membranes is that, under certain conditions, the external or internal grid can delaminate from the membrane. Because the materials of the grid and surrounding membrane are different, the thermal properties of the unit as a whole is poor because the grid and membrane have different rates of thermal expansion and contraction.


First and second clutches correspond to systems which include “first gear” and “second gear,” respectively. When the temperature of the first clutch at the time of start of the vehicle is lower than a first temperature, only the first clutch is used as a start clutch for driving the vehicle. When the temperature of the first clutch is not lower than the first temperature but is lower than a second temperature, both the first and second clutches are used as the start clutch. When the temperature of the first clutch is equal to or higher than the second temperature, only the second clutch is used as the start clutch. Thus, the higher the temperature of the first clutch, the smaller the load acting on the first clutch. When the temperature of the second clutch is high, engine torque is reduced, and a warning is issued.

1. Field of the Invention
The present invention relates to a power transmission control apparatus for a vehicle.
2. Description of the Related Art
As described in, for example, Japanese Patent Application Laid-Open (kokai) No. 2010-48416, there has been known a transmission which includes first and second input shafts for receiving power from an engine of a vehicle; an output shaft for outputting power to drive wheels of the vehicle; a first mechanism section which selectively establishes any one of some (odd gears including first gear) of all the gears to thereby form a power transmission system between the first input shaft and the output shaft; and a second mechanism section which selectively establishes any one of the remaining gears (even gears including second gear) to thereby form a power transmission system between the second input shaft and the output shaft.
This transmission includes first and second clutches in combination. The first clutch selectively achieves an engaged state so as to form a power transmission system between the output shaft of the engine and the first input shaft, or a disengaged state so as to cut off the power transmission system. The second clutch selectively achieves an engaged state so as to form a power transmission system between the output shaft of the engine and the second input shaft, or a disengaged state so as to cut off the power transmission system. A mechanism obtained through such a combination is called a "double clutch transmission (hereinafter also referred to as "DCT"). The first and second clutches are configured such that, by means of adjusting clutch stroke in an engaged state, the transmittable maximum torque (clutch torque) can be adjusted. In the following description, the system constituted by the first clutch, the first input shaft, and the first mechanism section will be referred to as the "first system," and the system constituted by the second clutch, the second input shaft, and the second mechanism section will be referred to as the "second system." An engaged state of each clutch in which slippage is involved will be referred to as a "half-engaged state," and an engaged state of each clutch in which no slippage is involved will be referred to as a "full-engaged state."
When the DCT is controlled, one gear to be achieved (hereinafter referred to as the "selected gear") is selected on the basis of a movement of a shift lever by a driver of the vehicle and/or travelling conditions of the vehicle. In the following description, of the first and second mechanism sections, the first and second clutches, the first and second input shafts, and the first and second systems, those corresponding to the selected gear will be referred to as the "selected mechanism section," the "selected clutch," the "selected input shaft," and the "selected system"; and those not corresponding to the selected gear will be referred to as the "unselected mechanism section," the "unselected clutch," the "unselected input shaft," and the "unselected system."
When a gear is selected, the selected clutch is controlled into an engaged state in a state in which the selected gear is established in the selected mechanism section, and the unselected clutch is controlled into a disengaged state. As a result, a power transmission system which has a speed reduction ratio for the selected gear is formed between the output shaft of the engine and the output shaft of the transmission via the selected system. Drive torque (engine torque) of the engine is transmitted to the drive wheels via the power transmission system, whereby the vehicle can be accelerated.
Meanwhile, in the unselected system, the unselected clutch is in a disengaged state. Accordingly, the unselected mechanism section can be caused to wait in a state in which a gear which is selected (may be selected) next is established. By making use of this, the following operation is enabled. Even in the case where a gear shift operation (upshift to a higher gear or downshift to a lower gear) results in reciprocal switching of the states of the first and second systems between the selected and unselected states, the engine torque can be continuously transmitted, without interruption, to the output shaft of the transmission (accordingly, to the drive wheels), through simultaneous execution of an "operation of bringing the engaged one of the first and second clutches into a disengaged state" and an "operation of bringing the disengaged one of the first and second clutches into an engaged state." As a result, gear shift shock can be reduced.

Power transmission control apparatus for vehicle


Apparatus (110, 180, 270, 330, or 360) either reforms a circumferential part (86) of a container body (11) radially outward to form a container body (64), or reforms a plurality of circumferentially-spaced parts (74) of the bottom recess portion (25) of a container body (11) radially outward to form a container body (62). The apparatus (110, 180, 270, 330, or 360) includes a body (158, 230, 288, 332, or 365) and has a tooling element attached thereto which may be a roller (172, 246, 302, or 350) or a swaging element (392). Means is included for providing relative transverse movement between the container body (11) and the tooling element (172, 246, 302, 346, or 392). Means (160, 222, 296, or 332) is provided for providing relative rotary movement between the container body (11) and the tooling element (172, 246, 302, or 346 ) in all embodiments except the apparatus ( 360 ) in which the bottom recess portion (25) is swaged. The method includes providing relative transverse movement between the container body (11) and the tooling element (172, 246, 302, 346, or 392), and in all embodiments except the one (360) in which reworking is achieved by swaging, relative rotary movement between the container body (11) and the tooling element (172, 246, 302, or 346) is provided.

1. Field of the Invention
The present invention relates generally to metal container bodies of the type having a seamless sidewall and a bottom formed integrally therewith. More particularly, the present invention relates to bottom contours that provide increased dome reversal pressure, that provide greater resistance to damage when dropped, that minimize or prevent growth in the height of a container in which the beverage is subjected to pasteurizing temperatures and/or extreme temperatures encountered in shipping and storage. Further, the present invention relates to apparatus and method for providing these improved bottom contours.
2. Description of the Related Art
There have been numerous container configurations of two-piece containers, that is, containers having a container body with an integral bottom wall at one end, and an open end that is configured to have a closure secured thereto. Container manufacturers package beverages of various types in these containers formed of either steel or aluminum alloys.
In the production of these container bodies, it is important that the body wall and bottom wall of the container be as thin as possible so that the container can be sold at a competitive price. Much work has been done on thinning the body wall.
Aside from seeking thin body wall structures, various bottom wall configurations have been investigated. An early attempt in seeking sufficient strength of the bottom wall was to form the same into a spherical dome configuration. This general configuration is shown in Dunn et al., U.S. Pat. No. 3,760,751, issued Sep. 25, 1973. The bottom wall is thereby provided with an inwardly concave dome or bottom recess portion which includes a large portion of the area of the bottom wall of the container body. This domed configuration provides increased strength and resists deformation of the bottom wall under increased internal pressure of the container with little change in the overall geometry of the bottom wall throughout the pressure range for which the container is designed.
The prior art that teaches domed bottoms also includes P. G. Stephan, U.S. Pat. No. 3,349,956, issued Oct. 31, 1967; Kneusel et al., U.S. Pat. No. 3,693,828, issued Sep. 26, 1972; Dunn et al., U.S. Pat. No. 3,730,383, issued May 1, 1973; Toukmanian, U.S. Pat. No. 3,904,069, issued Sep. 9, 1975; Lyu et al., U.S. Pat. No. 3,942,673, issued Mar. 9, 1976; Miller et al., U.S. Pat. No. 4,294,373, issued Oct. 13, 1981; McMillin, U.S. Pat. No. 4,834,256, issued May 30, 1989; Pulciani et al., U.S. Pat. No. 4,685,582, issued Aug. 11, 1987; and Pulciani, et al., U.S. Pat. No. 4,768,672, issued Sep. 6, 1988.
Patents which teach apparatus for forming container bodies with inwardly domed bottoms and/or which teach container bodies having inwardly domed bottoms, include Maeder et al., U.S. Pat. No 4,289,014, issued Sep. 15, 1981; Gombas, U.S. Pat. No. 4,341,321, issued Jul. 27, 1982; Elert et al., U.S. Pat. No. 4,372,143, issued Feb. 8, 1983; and Pulciani et al., U.S. Pat. No. 4,620,434, issued Nov. 4, 1986.
Of the above-mentioned patents, Lyu et al. teaches an inwardly domed bottom in which the shape of the domed bottom is ellipsoidal.
Stephan, in U.S. Pat. No. 3,349,956, teaches using a reduced diameter annular supporting portion with an inwardly domed bottom disposed intermediate of the reduced diameter annular supporting portion. Stephan also teaches stacking of the reduced diameter annular supporting portion inside the double-seamed top of another container.
Kneusel et al., in U.S. Pat. No. 3,693,828, teach a steel container body having a bottom portion which is frustoconically shaped to provide a reduced diameter annular supporting portion, and having an internally domed bottom that is disposed radially inwardly of the annular supporting portion. Various contours of the bottom are adjusted to provide more uniform coating of the interior bottom surface, including a reduced radius of the domed bottom.
Pulciani et al., in U.S. Pat. Nos. 4,685,582 and 4,768,672, instead of the frustoconical portion of Kneusel et al., teach a transition portion between the cylindrically shaped outer wall of the container body and the reduced diameter annular supporting portion that includes an upper annular arcuate portion that is convex with respect to the outside diameter of the container body and a lower annular arcuate portion that is concave with respect to the outside diameter of the container body.
McMillin, in U.S. Pat. No. 4,834,256, teaches a transitional portion between the cylindrically shaped outer wall of the container body and the reduced diameter annular supporting portion that is contoured to provide stable stacking for containers having a double-seamed top which is generally the same diameter as the cylindrical outer wall, as well as providing stable stacking for containers having double-seamed tops that are smaller than the cylindrical body. In this design, containers with reduced diameter tops stack inside the reduced diameter annular supporting portion; and containers with larger tops stack against this specially contoured transitional portion.
Supik, in U.S. Pat. No. 4,732,292, issued Mar. 22, 1988, teaches making indentations in the bottom of a container body that extend upwardly from the bottom. Various configurations of these indentations are shown. The indentations are said to increase the flexibility of the bottom and thereby prevent cracking of interior coatings when the containers are subjected to internal fluid pressures.
In U.S. Pat. No. 4,885,924, issued Dec. 12, 1989, which was disclosed in W.I.P.O. International Publication No. WO 83/02577 of Aug. 4, 1983, Claydon et al. teach apparatus for rolling the outer surface of the annular supporting portion radially inward, thereby reducing the radii of the annular supporting portion. The annular supporting portion is rolled inwardly to prevent inversion of the dome when the container is subjected to internal fluid pressures.
Various of the prior art patents, including Pulciani et al., U.S. Pat. No. 4,620,434, teach contours which are designed to increase the pressure at which fluid inside the container reverses the dome at the bottom of the container body. This pressure is called the static dome reversal pressure. In this patent, the contour of the transitional portion is given such great emphasis that the radius of the domed panel, though generally specified within a range, is not specified for the preferred embodiment.
However, it has been known that maximum values of static dome reversal pressure are achieved by increasing the curvature of the dome to an optimum value, and that further increases in the dome curvature result in decreases in static dome reversal pressures.
As mentioned earlier, one of the problems is obtaining a maximum dome reversal pressure for a given metal thickness. However, another problem is obtaining resistance to damage when a filled container is dropped onto a hard surface.
Present industry testing for drop resistance is called the cumulative drop height. As performed for tests reported herein, a filled container is dropped onto a steel plate from heights beginning at three inches and increasing by three inches for each successive drop. The drop height resistance is then the sum of all the distances at which the container is dropped, including the height at which the dome is reversed, or partially reversed. That is, the drop height resistance is the cumulative height at which the bottom contour is damaged sufficiently to preclude standing firmly upright on a flat surface.
In U.S. patent application 07/505,618 having common inventorship entity, and being of the same assignee as the present application, it was shown that decreasing the dome radius of the container body increases the cumulative drop height resistance and decreases the dome reversal pressure. Further, it was shown in this prior application that increasing the height of the inner wall increases the dome reversal pressure.
However, as the dome radius is decreased for a given dome height, the inner wall decreases in height. Therefore, for a given dome height, an increase in cumulate drop resistance, as achieved by a decrease in dome radius, results in a decrease in the height of the inner wall together with an attendant decrease in the dome reversal pressure.
Thus, one way to achieve a good combination of cumulative drop height and dome reversal pressure, is to increase the dome height, thereby allowing a reduction in dome radius while leaving an adequate wall height. However, there are limits to which the dome height can be increased while still maintaining standard diameter, height, and volume specifications.
An additional problem in beverage container design and manufacturing has been in maintaining containers within specifications, subsequent to a pasteurizing process, when filled beverage containers are stored at high ambient temperatures, and/or when they are exposed to sunlight.
This increase in height is caused by roll-out of the annular supporting portion as the internal fluid pressure on the domed portion applies a downward force to the circumferential inner wall, and the circumferential inner wall applies a downward force on the annular supporting portion.
An increase in the height of a beverage container causes jamming of the containers in filling and conveying equipment, and unevenness in stacking.
A large quantity of containers are manufactured annually and the producers thereof are always seeking to reduce the amount of metal utilized in making container bodies while still maintaining the same operating characteristics.
Because of the large quantities of container bodies manufactured, a small reduction in metal thickness, even of one ten thousandth of an inch, will result in a substantial reduction in material costs.

Apparatus and method for strengthening bottom of container


A car management system includes, for example, a second terminal generating first and second tokens in response to a request from a first terminal to use a vehicle, and sending the first token to the first terminal; and a third terminal authorizing the first terminal to use the vehicle by generating an access key that provides authority to use the vehicle using the first token and the second token in response to a request from the first terminal for the access key, and providing the generated access key to the first terminal.

1. Technical Field
The present disclosure relates generally to vehicles, and more particularly, to a car management system and method when a vehicle is shared among multiple users.
2. Description of the Related Art
Vehicle keys can be used to lock and unlock the vehicle, start the engine of the vehicle, and so forth. Typical keys for vehicles are physical keys that can lock or unlock the doors of the vehicle by being inserted into a key hole formed next to the door handle of the door, or to start or stop the engine by being inserted into a key hole formed inside the vehicle. Additionally, the use of remote-control typed keys using short range wireless communication, referred to as "smart keys," has been on the rise recently.
There may typically be multiple keys provided to a driver when a vehicle is purchased. Since there are regulations on reproduction of the car keys, if more keys are wanted, the reproduction of the keys needs to go through a separate, complicated authentication (certification) process.
If a single vehicle, e.g., a family car, is shared among several family members, the limitation on the number of keys for the vehicle may cause an inconvenience. Additionally, in a case of a car rental business with several customers, or a case of a business car that may be used by many people in a company, management of the keys for such cars becomes very difficult.


A sheet-form paper for separating portions produced by a portion control machine and dispensing from a paper feed system, each sheet of the sheet-form paper including a recess formed in at a side edge for receiving a male guide, and a slit extending inwardly from an edge of the recess for engaging a knife edge of the male guide. The slit extends from an innermost edge of the recess substantially perpendicular to the side edges of the sheet.

Various machines are used to produce portions in a portion control apparatus. In some of these portion control machines, sheet-form paper is used for separating the portions. These sheets are often dispensed from a paper feed system, which feeds the bottom-most sheet of paper from a vertical stack of individual sheets.
One type of portion control machine forms patties of material, such as ground meat. Originally, the patties were formed by hand but this involves human contact, which can involve unsanitary conditions, as well as a lack of uniformity in the weight, size and shape of the patties, and limitations on worker output.
Portion control machines for forming patties can overcame many of these short comings by producing patties in a sanitary manner that are substantially uniform in size, shape, and weight and can also result in a significant increase in per worker output.
A patty making machine typically includes a mechanism to dispense sheets of paper to be contacted with the patty to ensure separation of the patty from other patties or surfaces. These sheets prevent "sticking" between patties or portions thereof. The most commonly used type of sheet is made of paper coated with wax. Some dispensing mechanisms use rolls of paper that are cut or torn to a desired length. However, these rolls must be continuously replaced, which results in shut-down time for the patty making machine and interruption of the patty making process.
Other paper dispensing mechanisms utilize precut sheets of paper that have one or more holes in the paper. These sheets are stacked with the holes aligned and fitting over rods or pins from which the paper is torn during dispensing. However, requiring the rods to be threaded through the holes increases the difficulty in loading the paper. Further, cutting or tearing the paper can result in small fragments of paper being deposited upon the patty. The disadvantages associated with precut sheets of paper having holes to facilitate stacking the sheets has led to the use of a system wherein the sheets are provided with deformable elements, such as notches in the side edges of the sheets.
U.S. Pat. No. 5,137,172 shows a paper feed system suitable for use with a patty making machine to provide paper for separating the patties. A vertical stack of sheet-form paper is provided with a deformable element, such as a notch, on the side edge or edges. A paper hopper is adapted to receive and temporarily retail the stack of paper sheets and is adapted to dispense the sheets by feeding the bottom-most sheet of paper from the stack. A male guide associated with the inside surface of the paper hopper engages the deformable element on the side edge of the sheets. A proximal end of the male guide adjacent to where the paper is dispensed temporarily retains the paper sheets in such a manner that the bottom-most sheet is dispensed without tearing the paper. Essentially, the deformable elements, such as the notches, on the side edges of the sheets cause each individual sheet to be bent at an extreme angle when pulled past the male guide without tearing the paper.
Normally, the frictional force between the bottom-most sheet that is being dispensed and the next sheet in the stack is insufficient to pull the next sheet free from the guide, as it is not sufficient to overcome the "hold back" force resulting from the extreme bend required to free the paper from the guide. Accordingly, the next sheet is maintained within the paper hopper by its deformable element, and thus the paper should be dispensed only a single sheet at a time.
However, this required that the sheets be sufficiently stiff to provide adequate "hold back" force necessary to allow only a bottommost sheet to be pulled away. Nonetheless, problems still have been encountered with certain sheet-form paper stock wherein there still is a tendency to pull two sheets of paper at a time if the paper feed system is not adjusted properly. Adding a more severe bend to the deformed or notched paper to increase its "hold back" force might be considered a solution to this problem, but it has been found that there is a tendency to tear the paper if it must be deformed too severely.
Another problem with previous paper feed systems is that thinner sheets have a tendency to bow downwardly and fall out of the support means of the system. The feed mechanisms used to depose the separating sheets between the patties or portions require that the sheet be supported under two of its opposite edges. Specifically, the sheets are fed along a support means which normally includes a pair of side rails which support the two opposite side edge areas of the sheets. While supported, a patty or portion is deposited on top of a sheet which is then accelerated downward to the top of a stack below. Repeated positioning of additional sheets and subsequent depositing of the portions forms a stack of interleafed patties
Previously, thinner sheets, on the order of 0.002 inches thick could not be used because they had a tendency to fall down between the side support rails due to their own weight, even before a portion is deposited on the sheet. Therefore, "stiffer" interleaf sheets which would remain in position and did not fall out of the support rails during stacking were used.
An alternative solution was to provide a means for stiffening the sheets so that they do not fall through the support means, particularly providing a sheet without adding significant cost. In addition, the stiffening means can be used to reinforce deformable elements or notches at the side edges of the sheets to increase the "hold back" forces necessary to allow a bottommost sheet to be pulled away from the next sheet in a stack thereof.
However, these notches only provided improved support at the front and back portions of the sheet and did not provide improved support at the sides. As the paper was pulled forward, the paper would sag at the center and pull away from the sides, limiting the through put of the patty portion control machine and requiring the use of thicker, less flexible sheets.
Therefore, there remains a need for improved sheet-form paper that allows for thinner sheets without the inherent problems discussed above encountered when decreasing the thickness of the sheets.


A device is indicated for covering the aperture of an antenna having a parabolic reflector and an exciter. The cover is made of a rigid material. The cover includes a shield ring connected to the reflector and a plastic cover shaped like a flat or obtuse cone having a conical portion which closes the open end of the reflector. The wall of the conical portion of the cover forms an angle between 4.degree. and 6.degree. with a plane that is at a right angle to the axis of the shield ring.

1. Technical Field
The invention concerns a device for covering the aperture of an antenna which has a parabolic reflector and an exciter. A cover is made of a rigid material, whose outside diameter corresponds to the diameter of the reflector and is arched outward on the side that faces away from the reflector.
2. Description of the Prior Art
Covers are placed on antennas mainly to protect them from the effects of weather. Deposits of dirt, moisture and ice can unfavorably affect the transmission properties of antennas. Ice can furthermore add considerable weight to the antennas and can cause them mechanical damage.
In a known device according to DE 44 36 596 A1, a flexible foil is used on the outside of a rigid dielectric cover hood which arches outward, and is stretched over the antenna aperture with an outward inclining surface. The foil moves constantly when the wind blows on the antenna. This is to prevent frost deposits from accumulating. This device is costly to produce and costly to install. In case of necessity, the antenna and its exciter system can only be accessed by removing the foil and the cover hood.

Device for covering the aperture of an antenna


A steering safety mechanism for an automotive vehicle includes a steering shaft, a steering rack for turning a tire in response to rotation of the steering shaft, a steering motor for rotating the steering shaft or oscillating the steering rack leftward and rightward, and an electronic control unit for controlling the motor. The motor is rotated in a direction which limits rotation of the steering shaft in dependence upon vehicle velocity and steering angle, or vehicle velocity alone. This makes it possible to prevent the vehicle from skidding sideways and rolling over when the driver turns the steering wheel too sharply.

This invention relates to an effective steering safety mechanism which assures safety when the driver of an automotive vehicle turns the steering wheel of the vehicle suddenly and sharply.
In a known conventional power steering system, the force for turning the steering wheel is applied by the driver with an assist from a hydraulic or electric motor. Such a steering system adjusts the amount of power assist for the steering wheel in dependence upon vehicle velocity and steering angle, taking into account both steerability and safety. Power assist is applied for steering at low velocities in order to lighten the load on the driver when the steering wheel is turned. At high velocities, however, the power assist is limited in order to prevent a loss of stability that can be caused by a steering wheel that turns too lightly.
In the conventional power steering system, however, the chief aim is to provide the power assist in order to make it easier for the driver to turn the steering wheel for turns made at low velocity. No consideration is given to restricting steering or to positive application of a restoring force when the vehicle skids sideways due to centrifugal force or when the steering wheel is turned so sharply as to risk overturning the vehicle, both of these possibilities at high traveling velocities.
Recently, electric automobiles have been developed in which the front and rear wheels are capable of being steered up to an angle of 90.degree. by electric motors so that the vehicle can make small turns or travel in translational fashion. When the steering wheel is turned to sharply and suddenly in such a vehicle, there is the danger that the vehicle will skid sideways or roll over unless steering is restricted or a restoring force applied in a positive manner.


Integrated micro-valve is formed to control fluid flow and pressure. The valve converts supplied energy to mechanical energy through a means for energy conversion resident above a flexible wall or membrane. In one embodiment a sealed cavity contains a fluid that expands and contracts as it is heated or cooled, thus causing the flexible wall to move. Movement of this wall or membrane is used to move a valve element and dynamically control the opening or closing of a valve port over a predetermined range. Additional means for stiffening are added to the membrane to improve performance.

Micromachined integrated valves are known in the prior art. Examples of various embodiments of such normally open valves are given in U.S. Pat. Nos. 4,821,997 and 4,824,073 and 4,943,032 and 4,966,646; the disclosures of which are hereby incorporated by reference herein in their entirety.
U.S. Pat. Nos. 5,865,417 and 6,149,123 taught how to make a normally closed, micro-machined valve with a leak rate on the order of 1×10−9 scc-atm/sec or less of helium. U.S. Pat. No. 6,160,243 disclosed alternative methods of actuating micro-valves. U.S. Pat. Nos. 5,865,417 and 6,149,123 and 6,160,243 are included by reference herein in their entirety.
An integrated micro-valve, also commonly referred to as a microminiature valve, uses a thin flexible membrane with an actuator to move a valve element. In some embodiments, the flexible membrane is coupled to a cantilever element through a solid extension located on the membrane, as described in the referenced patents and shown in FIGS. 1 and 2, slightly modified from as presented in U.S. Pat. No. 6,149,123. Movement of the membrane 200 causes a cantilever element 300 to move and either open or close off valve seat 410. Port 400 is fluidically coupled to passageways serving as input 520 and output 510 channels. Element 210, typically referred to as a pedestal, is joined to cantilever 300 by an appropriate adhesive or other bonding technique. In FIG. 2 the membrane 200 is actuated and the cantilever 300 is now open. Element 415 is a compliant seat material meant to facilitate sealing against valve seat 410; typically this material is a Teflon-like material, either PTFE or derivatives thereof.
As previously disclosed, membrane 200 is typically 40 to 60 microns thick and of single crystal silicon. The burst strength of the membrane is quite sensitive to design considerations such as overall area and membrane thickness. Processing conditions such as etchants and etching conditions and other variables are also factors in membrane strength. As the inlet pressure in channel 520 increases the force required to open cantilever 300 increases; in addition, as the area of channel 400 increases the opening force also increases. Depending upon the actuation mechanism employed in region 130 of FIG. 1 membrane 200 may not expand outward uniformly; the membrane may expand in such a fashion that the cantilever remains unopened or insufficiently open to meet the design criteria.
The previously disclosed valves were not able to operate reliably above an, inlet pressure of 50 psig, pounds per square inch gauge, while delivering more than 10 slm, standard liters per minute, at an acceptable pressure drop. There is a need for a valve which can flow up to 20 slm at an inlet pressure of over 100 psig with an acceptable pressure drop.


An apparatus for controlling an opening angle of a throttle valve in an internal combustion engine. When an accelerator pedal is depressed by a vehicular driver, an accelerator drum attached onto an end wall of a main body of a single motor is rotated via an accelerator wire and the main body of the motor, a drive axle of the motor held with respect to the main body of the motor, and a rotation axle of the throttle valve are integrally rotated. When control is transferred from the above-described ordinary opening angle control state into a traction control state, the hold function of the motor is released and the motor is driven so as to reduce the opening angle of the throttle valve. It is possible to drive the motor so as to control the opening angle of the throttle valve, with the accelerator pedal released, to achieve an automatic cruise speed control and to drive the motor according to an accelerator pedal operating variable so that an arbitrary characteristic of the throttle valve opening angle control can be acheived.

1. Field of The Invention
The present invention relates generally to an apparatus for driving an engine throttle valve to control its opening angle applicable to an internal combustion engine.
2. Description of The Background Art
Recently, a control for a throttle valve of the internal combustion engine having multiple functions is generalized. The multiple functions are 1) a mere interlocking with an accelerator pedal depressed by an operator; 2) a traction control so as to reduce an opening angle of the throttle valve in order to reduce slips of vehicular tire wheels during a vehicular acceleration; and 3) an automatic cruise control such that a constant vehicular speed is maintained with the accelerator pedal open or not depressed. Simultaneously, a fail safe structure such that an overrun of the engine revolution is suppressed with the opening angle of the throttle valve held at a minimum position during a failure of the engine.
A Japanese Patent Application First Publication No. Showa 64-29633 published on Jan. 31, 1989 exemplifies a previously proposed throttle valve opening angle controlling apparatus in which the traction control is carried out.
In the disclosed Japanese Patent Application First Publication, an accelerator drum is rotated in a direction such that the opening operation of the throttle valve is enabled when the accelerator pedal is depressed. Then, the throttle valve is open which is engaged with the accelerator drum via a lever biased in the open direction of the throttle valve. During the traction control, the throttle valve is driven in a closed direction by means of a motor.
However, since, in the previously proposed throttle valve opening angle controlling apparatus, the motor can be driven only in the closed direction, another driving mechanism for the throttle valve becomes necessary when it is necessary to drive the throttle valve in the closed direction in addition to the open direction as in the case of the automatic cruise speed control.
In addition, in a case where the traction control is carried out, a structure of the throttle opening angle controlling apparatus becomes complex since the motor is used to close the throttle valve against a biasing force in the open direction of the lever. Furthermore, since the throttle valve is directly biased in the open direction, the throttle valve would open if a disengagement thereof from the acclerator pedal system occurs.

Apparatus for controlling opening angle of throttle valve in internal combustion engine

Japan Electronic Control Systems Co., Ltd.


A coil form for winding stator wire includes front and back coil forms which are designed to overcome the drawbacks of the known coil forms. The front coil form is adjustable between a first open position in which coils may be formed in a first series of sizes and a second closed position in which coils are formed in a second series of sizes. The adjustable front coil form allows tooling to be changed between even and odd winding form configurations without delays due to required set up time. The back coil winding form includes a tapered back surface which prevents coils from moving forward or unwinding before they are captured in a coil-receiving fork. This prevents coils from being received in an improper slot in the fork and allows the manufacture of a high quality product.

The present invention relates to the field of coil winding and, more particularly, to a coil winding form or holder on which wire coils may be wound in different lengths.
Various winding apparatus are known which are employed for winding sets of coils having different lengths and different pitches. A winding apparatus for winding these coils generally includes a rotatable coil winding flyer for winding coils of wire from a spool around a stepped coil holder or coil form. The coil holder is used to form coils of different lengths by winding on the different steps on the holder. As the wire coils are formed on the coil holder, the different length coils are moved from the coil holder onto a fork. The fork having coils of stator wire held between its teeth is inserted into an electric motor to introduce the stator wire to the motor.
In the winding of concentric stator wire coils it is necessary to wind the desired number of turns on each of the coil form steps and to move the flyer with respect to the coil form to space the coils or to move from one step to the next. A control means generally controls the winding of the coils determining the number and pitch of the coils to be wound on each of the levels of the coil form. An example of a coil winding apparatus and associated control means is shown in U.S. Pat. No. 4,046,175.
The differing number and size of the coils required for different stators, dictate the use of more than one coil form to achieve all the necessary sizes. However, switching between different coil forms is time consuming, delaying work, and reducing cell throughput. In order to reduce switching time, a plurality of coil forms can be mounted on a turret which is then rotated for winding on the different forms as shown in U.S. Pat. No. 3,851,682. However, a simpler and more compact solution to the need for multiple coil forms would be desirable.
As the coils are being wound on the coil form by rotation of the coil winding flyer around the coil form, they are dropped onto a hollow cylindrical fork with longitudinal slots. The fork is positioned to receive each of the coils in a particular set of slots. However, as the coils slide off the coil form onto the fork slack may occur in some of the coils which allows the coils to drop into an improper slot, or skip a tooth in the fork. The coils which have been collected on the fork are forced into the stator slots of a motor by the fork whose teeth fit into the stator slots in the motor. The presence of coils which have dropped into an improper slot in the fork and thus, end up in a wrong slot in the stator decreases the overall efficiency of the motor.


A pneumatic conveyor for granular materials which includes an apparatus for introducing the material into the entraining air stream. The apparatus includes a pressure vessel having means at its upper end for receiving allotments of material from an unpressurized source. Located within the vessel below the inlet is a feeder of the type having a hopper leading to reciprocating tray. The tray includes a plurality of inclined blades and provides a constant metered flow of the material between the blades to an outlet located adjacent the lower end of the pressure vessel. The lower end of the pressure vessel is connected to a transition throat leading directly to the conveying line through which passes the entraining air stream. The outlet of the feeder is spaced from the opening of the transition throat such that air pressure may pass about the exit and pressurize a lower portion of the pressure chamber outside of the feeder. The air pressure additionally passes through the material within the inside of the feeder to pressurize the upper portion of the pressure vessel. With this arrangement the pressure on each side of the material within the feeder is equal, allowing a normal gravity feed of the material through the hopper. The equalized pressures on the interior and exterior of the feeder aid in preventing damage to the feeder.

1. Field of the Invention
The present invention relates in general to pneumatic conveyor systems. In particular, the present invention relates to an improved apparatus for introducing granular, cylindrical or flake material, particularly for human consumption, into the airstream of a pneumatic conveying system.
2. Description of the Related Art
The advantages of pneumatic conveying systems have long been known. For example, pneumatic conveying systems have few moving parts, and thus are reliable and relatively efficient. Additionally, when used with food products intended for human consumption, the closed nature of the pneumatic conveying system assists in preventing contamination of the food product.
However, there are certain food products which have heretofore not been suitable for conveyance by pneumatic systems. In particular, ready-to-eat (RTE) cereals such as Rice Krispies.RTM., Cheerios.RTM., Fruit Loops.RTM. and corn flakes, and RTE cereal components such as cylindrical (or other shaped) marshmallow bits, have experienced unsatisfactory results during pneumatic conveyance. During such attempts it was found that the RTE cereal would bridge in the vessel holding the cereal for introduction to the airstream or plug the pneumatic conduit, impeding air and product flow. The continued provision of the entraining air up stream of the bridge would cause increased pressure in this area of the conduit, with the pressure finally reaching a sufficient level to force the material to unclog the conduit.
This unbridging of the material was rather violent, and was immediately followed by a period of higher than normal conveyance speed due to the higher than normal pressure. Both of these events caused unacceptable amounts of breakage of the material, resulting in fines. Such fines are undesirable because they tend to coat the cereal, reducing its luster, and additionally compact the density of the cereal to make weight-based packages appear to contain an insufficient amount of the product by reducing the volume per unit weight.
The present inventors have determined that a major cause for the bridging of the cereal within the conduit is fluctuations in the amount of material introduced into the pneumatic conveying system. For example, materials are mainly introduced into a pneumatic conveying system by one of two methods. In the first method batches of the material pass from an unpressurized hopper open to the atmosphere, through a baffle chamber or pressure lock, and finally into a second hopper open to the conveying air stream, and thus at an elevated pressure equal to that in the conveying conduit. The pressure lock maintains the pressure within the second vessel, and the conveying airstream is continuous. In the second method the material is placed in a vessel and the vessel is sealed. Thereafter the conveying air is activated to convey all material from the vessel, at which point the air is deactivated, and the vessel opened to receive new material. This procedure is repeated as required.
While such a pressurized vessel is necessary to maintain the required pressure within the conveying conduit, the introduction of the material into the airstream has heretofore been non-uniform.

Pneumatic conveyor for granular materials


A method of processing electron emitting devices for electron beam sources, wherein the electrons emitted from the electron beam source have an axial symmetric distribution of emitted electrons include determining a crystal axis direction of the crystal bar used as the material for the electron beam source, and cutting out chip material in such a manner that the longitudinal direction of the axis of the electron emitting device coincides with the crystal axis direction of the crystal bar. As a result, the emitted electrons becomes symmetrical to the axial direction, forming an axially symmetrical distribution, and a uniform electron irradiation on a specimen can be achieved in electron microscopes, electron beam inspection and measuring apparatus, electron lithography systems, and the like.

The present invention relates to an electron beam source for use in electron microscopes and electron beam inspection and measuring apparatus for evaluating and inspecting semiconductors integrated circuits, electron beam lithography systems for depicting circuit patterns on semiconductors, and the like. Particularly, the present invention relates to a method for processing materials of electron emitting devices for use in electron beam sources.
When a material for use in an electron beam source is manufactured, conventionally, the manufacturing has been mostly performed without regard to the to the crystal direction of the material. A method for obtaining a needle shaped electron emitting material having a curvature of equal to or less than 50 nm by forming a needle like end portion of a crystal rod or a crystal bar utilizing a cleavage plane, and subsequently performing an anisotropic etching has been disclosed in JP-A-5-101770 (1993). However, the prior art discloses a method for obtaining a field emission type cathode which is operable with the lowest voltage than ever before, and the prior art does not teach how to utilize the cleavage plane of the material in manufacturing.
FIGS. 2(a), 2(b), and 2c illustrate a conventional manufacturing method for an electron beam source. FIG. 2(a) is a plan view of a crystal bar, i.e., a material for manufacturing, FIG. 2(b) is a plan view and a side view of a chip base material 2 cut out from the crystal bar, and FIG. 2c is a plan view and a side view of a chip 3 cut out from the chip base material 2.
In accordance with FIG. 2(a), the crystal bar 1 has an axial direction 4 of its mechanical axis and an axial direction 5 of its crystal axis in the process of manufacturing, and the directions of the mechanical and crystal axes do not coincide each other. The end plane of the crystal bar 1 is tilted with respect to the axial direction 4 of the mechanical axis, and the end plane is a cleavage plane of the crystal. Conventionally, the chip base material 2 was cut out from the crystal bar 1 by cutting perpendicularly to the mechanical axis of the crystal bar 1 with a designated length, and the chip 3 was also cut out from the chip base material 2 in a manner that the longitudinal direction of the chip is the same as the mechanical direction 4 of the crystal bar 1. When the chip cut out in the manner described above is manufactured, the axial direction 4 of the chip 3 does not coincide with the crystal direction 5 of the chip 3.
FIG. 3 is a schematic side view of an electron emitting device 6 manufactured from the above chip 3, which is used by being attached to an electron beam source of the above-mentioned electron microscope, electron beam inspection and measuring apparatus, electron beam lithography system, and the like. The chip 3 is a rectangular solid as shown in FIG. 2(c), and the chip is manufactured into an electron emitting device 6 having a shape shown in FIG. 3. An end of the electron emitting devise 6 is formed as a hemispherical portion 61 for emitting electrons, and another end is a fixing portion for attaching to the electron beam source. The electron emitting device 6 is attached to the electron beam source so that the axial direction (shown by a one dot chain line) of the device coincides with the axial direction of the electron beam of the apparatus, and the electron beam is emitted from the hemispherical portion 61 of the electron beam emitting device 6 by applying a voltage.
In the above apparatus, not only the intensity and energy of the electron beam, but also uniformity of electron irradiation in a plane of the material, to which the electron beam is irradiated, must be controlled. When the electron emitting device 6 manufactured by the conventional method shown in FIG. 2 is used, the emitted electrons are not axially symmetrical to the axial direction 4, because the axial direction of the electron emitting device 6 does not coincide with the crystal direction 5. This results in a problem because the emitted electron distribution is not axially symmetrical.
FIG. 10 indicates a spread of an electron beam seen from the electron beam source when an electron beam is irradiated onto a specimen. For instance, in an electron beam lithography system, the size of the spread of the irradiated electron beam must be changed depending on the pattern to be depicted. The region A in FIG. 10 indicates the ordinary size of an irradiation field of the electron beam, and the region B indicates an extended field of the electron beam. When an electron emitting device 6 processed by the above conventional manufacturing method is used, the region B becomes not a circle but an ellipse, because the axial direction of the electron emitting device 6 does not coincide with the crystal direction 5. Accordingly, an effective region of beam for writing becomes a rectangle inscribed in the ellipse, which is smaller than a rectangle inscribed in a circle, as described in more detail below.

Method for processing electron beam sources


A measurement system used in conjunction with a conveyor includes a first sensor with a first transceiver and a second sensor with a second transceiver. The transceivers transmit a first light beam and a second light beam towards a movable portion of the conveyor. A control unit communicably coupled to the first sensor and the second sensor, wherein the control unit calculates a first distance between the first sensor and the movable portion based on the first sensor and a second distance between the second sensor and the movable portion based on the second sensor. The control unit determines a difference value between the first distance and the second distance; and stops the unloader in response to the difference value being above a predefined threshold value.

Trucks and trailers loaded with cargo, cartons and products move across the country to deliver products to commercial loading and unloading docks at stores, warehouses, and distribution centers. Trucks can have a trailer mounted on the truck, or can be of a tractor-semi trailer configuration. To lower overhead costs at retail stores, in-store product counts have been reduced, and products-in-transit now count as part of available store stock. Unloading trucks quickly at the unloading docks of warehouses and regional distribution centers has attained new prominence as a way to refill depleted stock.
Trucks are typically unloaded with forklifts if the loads are palletized and with manual labor if the products are stacked within the trucks. Unloading large truck shipments manually with human laborers can be physically difficult, and can be costly due to the time and labor involved. Consequently, a need exists for an improved unloading system that can unload bulk quantities of stacked cartons and cargo from truck trailers more quickly than human laborers and at a reduced cost.
Further, the unloaded cargos or cartons are proceeded to further steps of processing in the warehouses and distribution centers. Often, a conveyor may aid in receiving the unloaded cargos or cartons from the unloading system and move it into multiple stations in the warehouse or distribution center for further processing. Consequently, a need exists for an improved conveying system which could be used in conjunction with the unloading system for efficient unloading of cartons or cargos in an autonomous manner without any manual intervention.


A semiconductor film, which is located over a gate electrode for forming a channel region between a source electrode and a drain electrode, has a width greater than a width of the source electrode and a width of the drain electrode located over the gate electrode. Irregularities are formed in a width direction of the semiconductor film on both edge portions in the channel region.

1. Field of the Invention
The present invention relates to a thin film transistor, a liquid crystal display using this thin film transistor, and a method of manufacturing the thin film transistor. More specifically, the present invention relates to a thin film transistor with improved on-current and channel length, a liquid crystal display using this thin film transistor, and a method of manufacturing this thin film transistor.
2. Description of the Related Art
Liquid crystal displays using thin film transistors (TFTs) as switching elements have widely spread. An inverted staggered structure is adopted in many amorphous silicon (a-Si) TFTs. While TFTs are classified into a channel protection type or a channel etch type, the channel etch type is the mainstream today in order to reduce the number of manufacturing steps.
Although a method of manufacturing a channel etch type TFT realizable by using five or six masks has been conventionally applied, a method of manufacturing a channel etch type TFT realizable by using four masks has been disclosed in order to further reduce the number of manufacturing steps.
For example, according to Japanese Laid-open Patent No. 2000-164886, the number of manufacturing steps is reduced by using a photosensitive film, which is formed thinly at a channel region of a TFT and formed thickly in source and drain electrode formation regions, while removing the photosensitive film in other regions, so as to isolate source and drain electrodes made of the same metal layer. Firstly, a conductive layer is formed on an insulating substrate, and the conductive layer is patterned to form a gate wiring by use of a first photomask while applying the photo-lithographic technique and the etching technique. A gate insulating film is formed on the gate wiring and a semiconductor layer, an n+ doped semiconductor layer, and source and drain metal layers are laminated. Subsequently, a photosensitive film is formed thickly on a source electrode formation region and on a drain electrode formation region and is formed thinly on a region between the source and the drain electrode formation regions by use of a second photomask and the photo-lithographic technique. Further, the source and drain metal layers, the n+ doped semiconductor layer, and the semiconductor layer are etched by using this photosensitive film as a mask to pattern the source and drain electrodes, the n+ doped semiconductor layer, and the semiconductor layer. At the same time as the etching of the n+ doped semiconductor layer and the semiconductor layer, the thickness of the photosensitive film is reduced by removing controlled amount of the thin photosensitive layer in the region between the source and the drain electrode formation regions.
The photosensitive film on the source and drain electrode formation regions is reduced in the thickness but still remains thereon. By etching the source and drain metal layers exposed between the source and drain electrode formation regions and further etching the n+ doped semiconductor layer between the source and drain electrode formation regions, the source and drain electrodes as well as the n+ doped semiconductor layer are patterned. Then, the photosensitive film is removed.
Next, a passivation layer is formed and then a contact hole is formed by use of a third photomask while applying the photo-lithographic technique and the etching technique. Subsequently, a transparent conductive film is formed and a pixel electrode is formed by use of a fourth photomask while applying the photo-lithographic technique and the etching technique.
Above mentioned photosensitive film will be described at photo-resist, hereafter.
Meanwhile, Japanese Laid-open Patent No. 2001-324725 discloses a photomask pattern, which is configured to form a photo-resist pattern thickly at source and drain electrode formation regions and to form the photo-resist pattern thinly at a region between the source and drain electrode formation regions. As shown in FIG. 1A, this photomask pattern includes two light shielding regions 111a for covering to form source and drain electrodes, and an narrow rectangular light shielding portion 112a disposed between the two light shielding regions 111a while respectively interposing slits 113a. Exposure is performed by use of the above-described photomask pattern. Based on the understanding that there arises a problem that there becomes non uniform in thickness a thin photo-resist pattern in a channel region between the source and drain electrode formation regions when using the above-described mask pattern, there is also disclosed a photomask pattern includes light shielding regions 111b having cut-off corners on both ends as shown in FIG. 1B, for example. A photo-resist pattern is formed by use of the above-described photomask pattern, and then a metal layer, an n+ a-Si layer, and an a-Si layer are etched to pattern source and drain electrodes, the a-Si layer, and the n+ a-Si layer. Thereafter, a thin portion of the photo-resist pattern between the source and drain electrode formation regions is removed. Further, the n+ a-Si layer and the a-Si layer are etched by using the separated photo-resist pattern as a mask.
Meanwhile, Japanese Laid-open Patent No. 2002-55364 also discloses photomask patterns in various shapes. For example, as shown in FIG. 2A, there is disclosed a photomask pattern including a plurality of narrow rectangular light shielding portions 112d arranged while interposing slits 113d between two light shielding regions 111d. When a thin film transistor is manufactured by use of this photomask pattern, a semiconductor film 104 above a gate electrode 102 and between a source electrode 106a and a drain electrode 106b, i.e. each endportion of a channel region in the semiconductor film 104, is formed in a bent manner due to a light interference phenomenon, as shown in FIG. 2C. In this specification, such end portions of a channel region of a TFT will be here in after referred to as both edge portions. When bending occurs in both edge portions of this semiconductor film 104, a path of an on-current of the TFT is also flexed. Accordingly, image quality of a liquid crystal display formed by arranging such TFTs in a matrix will be degraded. To prevent occurrence of the flexure on the both edge portions, there is also disclosed a technique to form a wide semiconductor film 104 as shown in FIG. 2D by use of a photomask pattern in the shape as shown in FIG. 2B, for example.
Moreover, Japanese Laid-open Patent No. 2002-57338 discloses that uniformity of the thickness of the thin photo-resist pattern for forming the channel region between the source and drain electrode formation regions is degraded by use of the above-described photomask pattern shown in FIG. 1A. In addition, this gazette also discloses problems that unevenness in the channel length among the TFTs is increased when using the photomask pattern as shown in FIG. 1A due to nonuniformity of the film thickness of the photo-resist pattern, and that display characteristic of a liquid crystal display is degraded as a consequence. To solve these problems, there is disclosed an improvement in the shape of light shielding regions 111c of the photomask pattern as shown in FIG. 1C.
Incidentally, each of these photomask patterns includes a light transparent portion, the light shielding region, and a semi-transparent region which is made up of a light transparent and light shielding pattern below resolution ability of an exposure apparatus. Light transmission amount of this semi-transparent region is susceptible to unevenness of the photomask pattern caused in manufacturing. For example, in the photomask pattern shown in FIG. 1B, each endportion of an aperture slit is formed wider than the center portion of the aperture slit, while width of a semi-transparent region is selected equal to or narrower than the resolution ability of the exposure apparatus. In particular, the influence of unevenness of the photomask pattern caused in manufacturing is more significant at the end portion as compared to the center of the aperture slit. Accordingly, the light transmission amount in the semi-transparent region is different between the center and the end portion of the aperture slit. Therefore, there is a problem that the thickness of the photo-resist pattern formed in the semi-transparent region becomes non uniform.
Meanwhile, in the photomask pattern shown in FIG. 2B, the semi-transparent portion inside the channel region includes the aperture slits and the light shielding regions which are longitudinally aligned, and the both edge portions on an upper part and on a lower part of the channel region include the aperture slits and the light shielding regions which are laterally aligned. If the dimensional accuracy of the photomask pattern in terms of the longitudinal direction is different from the dimensional accuracy in terms of the lateral direction, the thickness of the photo-resist pattern formed inside the channel region is different from the thickness of the photo-resist pattern formed on the both edge portions to be formed on the upper part and the lower part of the channel region. If the thickness of the photo-resist at a center portion of the channel region is different from the thickness of the photo-resist at the both edge portions thereof, expansion amounts of the channel length and a channel width fluctuate due to variation in an exposure amount, and it is therefore difficult to stabilize on-current characteristic of the TFT. For example, when the thickness of the photo-resist at the both edge portions becomes thinner than the thickness of the photo-resist at center portion of the channel region, the exposure amount most suitable for the channel length fluctuates and the on-current of the TFT is thereby reduced. On the contrary, when the thickness of the photo-resist at the both edge portions becomes thicker than the thickness of the photo-resist at center portion of the channel region, the on-current of the TFT is increased but it is necessary to secure a sufficient interval from the channel width to an end of a gate electrode. Accordingly, it is necessary to elongate a gate electrode. When this gate electrode is elongated, the area occupied by the TFT is spread while an aperture ratio is reduced. Therefore, it is preferable to set both dimensional accuracy in the longitudinal direction of the photomask pattern and in the lateral direction thereof to the same degree, and it is necessary to strictly manage the unevenness of the photomask in manufacturing.
In addition, when light is irradiated from a transparent insulating substrate side, an off-current of the TFT, i.e. a light leak current is increased when the light reaches the a-Si layer in the vicinity of the drain electrode without being shielded by the gate electrode. As shown in FIG. 2D, in the TFT formed by use of the photomask of FIG. 2B, each portion of the a-Si layer protruding beyond the drain electrode and located outside of the gate electrode contributes to generation of the leak current. Accordingly, the light leak current is further increased.
Meanwhile, in the mask pattern shown in FIG. 1C, aprotruded portion is formed in a narrow rectangular portion 112cin the vicinity of an end portion of the aperture slit 113c, while a width of the light transparent region is selected equal to or below the resolution ability of the exposure apparatus. However, the influence of the unevenness of the photomask pattern in manufacturing is larger at the protruded portion in the vicinity of the end portion of the aperture slit 113c than in the center portion thereof. Accordingly, a problem similar to the case using the mask pattern shown in FIG. 1B arises.

Thin film transistor, liquid crystal display using thin film transistor, and method of manufacturing thin film transistor


The present invention provides a method of manufacturing a single-electron transistor device (100). The method includes forming a thinned region (110) in a silicon substrate (105), the thinned region (110) offset by a non-selected region (115). The method also includes forming at least one quantum island (145) from the thinned region (110) by subjecting the thinned region (110) to an annealing process. The non-selected region (115) is aligned with the quantum island (145) and tunnel junctions (147) are formed between the quantum island (145) and the non-selected region (115). The present invention also includes a single-electron device (200), and a method of manufacturing an integrated circuit (300) that includes a single-electron device (305).

The continuing demand for increasing computational power and memory space is driving the miniaturization of integrated circuits. To sustain progress, miniaturization will soon be driven into the nanometer regime. Unfortunately, conventional devices cannot be scaled down straightforwardly because of problems caused by parasitic resistance, scattering and tunneling, among other things.
Single-electronics offer solutions to some of the problems arising from miniaturization. Single-electronic devices can be made from readily available materials and can use as little as one electron to define a logic state. Unlike conventional devices, single-electron devices show improved characteristics when their feature size is reduced. This follows from the fact that single-electron devices are based on quantum mechanical effects which are more pronounced at smaller dimensions. Single-electron devices also have low power consumption and therefore there are no energy restrictions to exploit the high integration densities that are possible with such devices.
The practical implementation of single-electronic devices has yet to be realized, in part because there is no practical process technology to mass produce nanometer-scale single-electron device structures. Additionally, no process exists for manufacturing single-electronic devices that can be readily combined with present procedures for manufacturing very large scale integrated circuits (VSLI). One reason for the lack of a practical process involves problems in the manufacture of quantum islands and their alignment with other device components.
Quantum islands are a central structural feature of all single-electron devices. Those skilled in the art are familiar with discrete electron tunneling and with other terms used to refer to the quantum island, such as a quantum dot, a grain, a particle or node. The term quantum island as used herein is defined as the structure between contacts, such as a source and drain electrodes. The structure of the quantum island must facilitate the movement of discrete electron tunneling from the source to the quantum island and from the quantum island to the drain.
Conventional methods for forming quantum islands are either impractical or incompatible with existing VSLI process technology. For instance, it is impractical to produce quantum islands in commercial numbers by scanning tunneling microscopy (STM) or atomic force microscopy (AFM). It is also problematic to form quantum islands by using lithographic procedures to select an area of silicon and then performing repeated cycles of etching and oxidation to define the island. The pitch between quantum islands formed in this manner is undesirably large (e.g., center to center distance of greater than 200 nanometers) because of the limits in resolution of existing lithographic technology.
Quantum islands formed by growing germanium, or depositing gold clusters, on silicon substrates suffer from alignment problems. That is, once gold or germanium quantum islands are formed on the substrate, it is very difficult to reproducibly align electrical contacts with the quantum island. This, in turn, makes it difficult to produce single-electron devices with reproducible performance characteristics, and to connect such devices to traditional device components, such as metal oxide semiconductors (MOS) devices.
Accordingly, what is needed in the art is a single-electron device and method of manufacturing thereof that overcomes the above-mentioned problems, and in particular allows for the production of quantum islands that can be easily and reproducibly aligned with contact electrodes.

Method to manufacture silicon quantum islands and single-electron devices


A method of operating a vehicle having a friction braking system and a regenerative braking system is presented here. The method determines a regenerative torque capacity, calculates a desired regenerative torque amount for the braking system, detects that the desired regenerative torque amount exceeds the regenerative torque capacity by at least a threshold amount, and controls actuation of the friction braking system in response to the detecting. Another operating method determines a coastdown torque capability of the vehicle, calculates a desired coastdown torque amount, detects that the desired coastdown torque amount exceeds the coastdown torque capability by at least a threshold amount, and controls actuation of the friction braking system in response to the detecting.

Automobile drivelines generally provide some level of deceleration when the driver releases the accelerator pedal. In conventional internal combustion vehicles with automatic and manual transmissions, this is a function of the transmission gear and the amount of engine drag, and is always present. In hybrid/electric vehicles, this is provided by regenerative braking torque used to recharge a battery, which provides power to a traction motor to propel the vehicle. In some vehicles, particularly hybrid/electric vehicles and vehicles with dual dry clutch transmissions, the amount of driveline deceleration can be reduced or unavailable depending on various parameters.
The popularity of hybrid electric, plug-in hybrid, and fully electric vehicles continues to increase over time. Accordingly, the prior art is replete with different systems, control technologies, and processes related to the operation of such vehicles. A hybrid electric vehicle (HEV) includes a rechargeable energy storage system (ESS) which is usually configured as a rechargeable battery or battery pack having a relatively high energy density. An HEV can also include a gasoline, diesel, or alternative fuel internal combustion engine. Other vehicle designs may employ a fuel cell and/or another power source in place of or in conjunction with an internal combustion engine in order to further reduce vehicle emissions and improve the operating range of the vehicle. A fully electric vehicle (EV) only includes an electric drive train, e.g., an electric motor and an ESS.
In certain HEV and EV designs, the drive wheels of the vehicle remain continuously connected to the driveline to enable regenerative braking capability, thus providing a relatively efficient means of capturing useful and otherwise wasted braking energy during coastdown and/or during active braking. As is known in the art, an electric motor/generator (MOGEN) can be selectively operated in such a manner as to allow the device to act as a generator during coastdown or an active regenerative braking event. When acting as a generator, the electric MOGEN recharges the ESS while applying a negative torque to the drive wheels and/or the drive shaft, thus electronically slowing the vehicle. The electric MOGEN likewise can be selectively operated as an electric motor, thus drawing stored electrical energy from the ESS as needed to propel the vehicle.
Regeneration during coastdown or active braking contributes to the deceleration of the vehicle. In this regard, negative coastdown regenerative torque can be applied to mimic the engine drag characteristics of a traditional non-electric vehicle. Moreover, negative braking regenerative torque can be applied as a function of brake pedal travel to mimic the characteristics of a standard vacuum-based hydraulic brake system. In practice, braking regenerative torque can be applied as an additive torque to the friction brake torque (which is generated in response to driver actuation of the brake pedal), which allows lower cost and complexity as opposed to fully-blended regenerative braking systems.
In certain situations, the vehicle may have little to no capacity to handle regenerative torque. For example, if the high voltage ESS is fully charged (or has a sufficiently high state of charge), then regenerative torque may be unavailable. As another example, during wheel slip conditions the regenerative braking system may be temporarily disabled to enable an automatic braking system, a traction control system, and/or other systems to immediately initiate and operate. Also cases in which multiple-mode hybrid transmissions shift between modes/gears. In other scenarios, it may not be possible to carry regenerative torque through a shifting operation (or it may be desirable to inhibit regenerative torque during shifting for various reasons, e.g., to reduce noise or vibration). When regenerative torque is unavailable for any reason, then the actual vehicle deceleration will be less than expected due to the loss of deceleration: the coastdown regenerative torque and the additive braking regenerative torque. The perceived difference in deceleration is a function of the normal levels of regenerative torque. For example, if the coastdown deceleration is calibrated to a higher level to allow one pedal driving, then the loss of regenerative torque will be more noticeable than if it were calibrated to a more traditional value in line with engine drag.
Similarly, in some non-hybrid vehicles such as vehicles with dual dry clutch transmissions, the deceleration from the driveline may be unavailable. In the case of dual dry clutch transmissions, the clutch may become overheated and will therefore be forced to open. The deceleration due to engine drag will then not be transmitted to the drive axle. In this case, the application of the friction brakes will restore the feeling of normal coastdown deceleration.
Accordingly, it is desirable to have a vehicle control system that addresses the scenarios mentioned above. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

Normalizing deceleration of a vehicle having a regenerative braking system


A sequence or array of electrochemical cells storing both digital and analog data. Both binary code and codes having a higher base may be stored in the memory device to increase information density. Such battery arrays could also provide power for the micro or nanodevice. Devices are microscale and nanoscale in size and utilize electrically conductive atomic force microscopy tips to record and read data stored in the device.

1. Field of the Invention
The present invention relates to microscale and nanoscale arrays of electrochemical cells and batteries for computer and nanodevice memory and power supply. Specifically, the present invention relates to a two-dimensional array of electrochemical cells or batteries that may be used to store both digital and analog information. Techniques for both read-only and read-and-write memory storage are disclosed.
2. Prior Art
Nanotechnology is a rapidly expanding field. The desire for miniaturization of electronics, assays and memory devices stems from many factors. Smaller devices require less material, thereby reducing production costs. Because the distances between points are shorter, nanoscale circuitry operates much more quickly than larger circuit boards. Information stored in very small devices may be accessed and read very quickly. Smaller devices are also less cumbersome and more easily transported.
The extremely high speed and small volume of microscale and nanoscale memory devices make them highly desirable. This has led to research into a variety of methods to form extremely small memory storage devices.
Atomic force microscopy (AFM) cantilever tips have become a common tool in nanotechnology. AFM tips were originally developed in order to study surface topography of a material at the molecular level. Changes in the surface of as little as a few tenths of nanometers (Angstroms) may be discerned utilizing AFM tips. When an electric current is applied to an AFM tip it may also be used for scanning tunneling microscopy (STM). This also provides for nanometer scale readings of a surface's topography.
AFM tips have found a variety of other uses. They may be used to move individual atoms about a surface to create a variety of structures on the atomic level. AFM tips have also been used to puncture holes into a surface. For example, IBM has developed a method of using AFM tips to form patterns on a pliable surface (See, for example: W. P. King, T. W. Kenny, K. E. Goodson, G. C. M. Despont, U. Durig, H. Rothuizen, G. K. Binnig, P. Vettiger, Applied Physics Letters, 78, 1300 (2001); E. Gorchowski and R. F. Hoyt, IEEE Trans. Magn. 32, 1850 (1996); D. A. Thompson and J. S. Best, IBM J. Res. Dev. 44, 311 (2000)). The surface has a thin layer of a material having a relatively low melting point. An AFM tip is heated to a temperature above the surface's melting point and is applied to the surface. The tip melts a cavity into the surface. This device is used to store data in binary code. When a non-heated tip is run across a series of holes, a hole may serve as a "1" while portions of the material that are not punctured serve as a "0". One disadvantage of the IBM technique is that it is difficult and time consuming to effectively remove a single data point. Another disadvantage is that it is difficult to effectively erase stored data completely. The more data is stored and erased on a surface, the more convoluted the surface becomes and eventually no longer performs adequately. Another disadvantage is that this technique may only store digital, binary data.
Nanoscale batteries have also been of interest as means for supplying nanoscale devices. Thin-film rechargeable batteries with active layers of 1-10 μm have been of interest since the 1980s, and previous studies have dealt almost exclusively with thin film work (See, for example: J. B. Bates, G. R. Gruzalski, M. J. Dudney, C. F. Lick, H.-h. Yu, and s. D. Jones, Solid State Technology, 36, No 7, 59, 1993). Thin-film microbatteries have been made by a deposition technique using a metallic lithium electrode layer with a solid Li3PO4 electrolyte. However, these batteries have lateral dimensions greater than a centimeter and produced current densities of only 8.3 μA/cm2 at an output voltage of approximately 4 V. A microbattery using a Ni/Zn electrode couple with an aqueous KOH electrolyte has also been developed (See, for example: L. G. Salmon, R. A. Barksdale, B. R. Beachem, R. M. LaFollette, J. N. Harb, J. d. Holladay, and P. H. Humble, "Development of Rechargeable Microbatteries for Autonomous MEMS Applications," in Solid-State Sensor and Actuator Workshop (Transducer Research Foundation, Inc. Hilton Head, S.C., 1998) pp 338-341). Once again, fabrication involves a deposition process for the two electrodes, with a polymer layer that is later removed to form the electrolyte cavity. These planar microbatteries were 200 μm×200 μm and had capacities of 200-200 mC/cm2 at current densities of 10-20 mA/cm2 with an operating voltage of 1.5 V. A carbon-based rechargeable lithium microbattery has been contemplated, but the progress in fabricating the electrode microstructure has been slow. This technology is based on photoresist technology commonly used in the semiconductor industry and electrodes are to be made from arrays of microelectrodes having diameters as small as 5 μm (See, for example: Kinoshita, K., Song, X., Kim, J., Inaba, M., Kim, J., Journal of Power Sources 82, 170 1999). The majority of the most recent papers on microbatteries follow these trends by describing systems where very thin films of electrolyte material were used to construct the battery, or by discussing the potential for these films to be used in batteries. The actual size of the batteries based on the electrode structure is much greater than the nanometer scale. (Levasseur, A., Vinatier, P., Gonbeau, D., Bull. Mater. Sci. 22 (3), 607 (1999); Han, K. S., Tsurimoto, S., Yoshimura, M., Solid State Ionics 121 (1-4), 229 (1999); Park, Y., Kim, J. G., Kim, M. K., Chung, H. T., Um, W. S., Kim, M. H., Kim, H. G., J. Power Sources 76 (1), 41 (1998); N. C. Li, C. J. Patrissi, G. G. Che, and C. R. Martin, J. Electrochem. Soc., 147, 2044 (2000); N. C. Li, C. R. Martin, and B. Scrosati, Electrochem. And Solid State Lett., 3, 316 (2000))
Additional attempts have been made to fabricate micro and nanobattery components and systems taking advantage of nanoscale technology and assembly. Nanoscale electrode systems have been made using a template synthesis method. Systems composed of LiMn2O4, SnO2, TiS2, sol-gel V2O5 materials, and carbon tubes have been used to make nanoscale electrode materials that typically show higher capacities, lower resistance, and lower susceptibility to slow electron-transfer kinetics than standard electrode configurations (V. M. Cepad, J. C. Hulteen, G. Che, K. B. Jirage, B. B. Lakshmi, E. R. Fisher, and C. R. Martin, Chem. Mater. 9, 1065 (1997); C. J. Patrissi and C. R. Martin, 146, 3176 (1999); G. G. Che, B. B. Lakshmi, E. R. Fisher, and C. R. Martin, Nature 393, 346 (1998); S. V. Batty, T. Richardson, F. B. Dias, J. P. Voss, P. V. Wright, and G. Ungar, Thin Solid Films, 284-285, 530 (1996); Y. Zheng, F. B. Dias, P. V. Wright, G. Ungar, D. Bhatt, S. V. Batty, and T. Richardson, Electochim. Acta, 43, 1633 (1998)). Langmuir-Blodgett films have been made that have ion-conducting layers that have the potential to be used as electrolytes in nanobattery systems. Self-assembly mechanisms may also be used to construct a high energy density rechargeable lithium ion batteries by using a layer-by-layer self-assembly of poly(diallyldimethyl-ammonium chloride), graphite oxide nanoplatelets and polyethylene oxide on indium tin oxide with a lithium wire as a counter electrode. Systems with 10 self-assembled layers have high specific capacities ranging from 1100 to 1200 mAH/g. (J. H. Fendler, J. Dispersion. Sci. Tech., 20, 13 (1999); S. Vorrey and D. Teeters, Electrochimica Acta, 48, 2137 (2003); A. L. Layson, Shailesh Gadad, Dale Teeters, Electrochimica Acta, 48, 2207 (2003)).
Assignee is the owner of U.S. Pat. No. 6,586,133 for "Nano-Battery Systems" which is incorporated herein by reference, and which discloses a process of providing a membrane with a plurality of pores, filling the membrane pores with an electrolyte, and capping the filled pores with electrodes.
The use of AFM tips for fabrication and data storage has evolved separately from the techniques being developed for making nanoscale batteries. Nothing in the prior art has contemplated the use of arrays of miniaturized batteries to store data at a very small scale.
It is therefore desirable to develop a nanoscale storage device that may be erased and rewritten several times without deteriorating.
It is also desirable to develop a nanoscale memory device capable of storing analog information.
It is also desirable to provide a nanoscale memory device that uses and electronic charge or current to store both erasable and permanent information.

Charged arrays of micro and nanoscale electrochemical cells and batteries for computer and nanodevice memory and power supply


The ability to switch at will between amperometric measurements and potentiometric measurements provides great flexibility in performing analyses of unknowns. Apparatus and methods can provide such switching to collect data from an electrochemical cell. The cell may contain a reagent disposed to measure glucose in human blood.

Electrochemical reactions may be used to measure quantities and concentrations in solutions.
FIG. 1 is a schematic diagram of an electrochemical interface apparatus, also known as a potentiostat, for a standard three-electrode configuration. Electrochemical cell 39 has a reference electrode 37, a counter electrode 36, and a working electrode 38. The cell 39 contains a substance being analyzed as well as a reagent selected for its utility. The reagent forms part of an electrochemical reaction. It will be appreciated that there are other circuits that can accomplish the functions described here, and that this is only one embodiment thereof.
A voltage is applied to the cell at 36, based upon a voltage input provided at input 34. This voltage at 34 is defined relative to a ground potential 40. In some embodiments this is a known voltage. More generally, in a three-electrode system, the voltage at 36 assumes whatever value is needed to make sure that the potential difference between 37 and 38 is substantially equal to the potential difference between 34 and 40.
Amplifier 35, preferably an operational amplifier, is used to provide gain as needed and to provide isolation between the input 34 and the electrodes 36 and 37. In the arrangement of FIG. 1 the gain is a unity voltage gain and the chief function of the amplifier 35 is to provide a high-impedance input at 34 and to provide sufficient drive to work with whatever impedance is encountered at electrode 36.
As the electrochemical reaction goes forward, current flows. Working electrode 38 carries such current. A selector 31 selects a resistor from a resistor bank 30, to select a current range for measurement of this current. Amplifier 32, preferably an operational amplifier, forms part of a circuit by which an output voltage at 33 is indicative of the current through the electrode 38. The output voltage at 33 is proportional to the product of the current at 38 and the selected resistor.
In one example, blood such as human blood is introduced into the cell. A reagent in the cell contributes to a chemical reaction involving blood glucose. A constant and known voltage at 34 is maintained. The output voltage at 33 is logged and the logged data are analyzed to arrive at a measurement of the total current that flowed during a defined measurement interval. (Typically this interval is such that the reaction is carried out to completion, although in some embodiments the desired measurements may be made without a need for the reaction to be carried out to completion.) In this way the glucose level in the blood may be measured.
As will be discussed below, the input at 34 may preferably be other than constant. For example it may be preferable that the input at 34 be a waveform selected to optimize certain measurements. The analog output of a digital to analog converter may be desirably connected at input 34, for example.
The measurement just described may be termed an "amperometric" measurement, a term chosen to connote that current through the reaction cell is what is being measured.
In some measurement situations it is possible to combine the counter electrode and the reference electrode as shown in FIG. 2, into a single electrode 41.
One example of a prior art circuit is that shown in German patent application DE 41 00 727 A1 published Jul. 16, 1992 and entitled "Analytisches Verfahren für Enzymelektrodensensoren." That circuit, however, does not, apparently, perform an amperometric measurement upon the reaction cell. That circuit appears to perform voltage readings, and an integrated function of voltage, with respect to a reference electrode of a cell (relative to a working electrode of the cell) and not with respect to a counter electrode (relative to the working electrode of the cell).
In this circuit the measured potential is a function of (among other things) the concentration of an analyte. Stating the same point in different terms, this circuit does not and cannot yield a signal that is independent of concentration of the analyte.

This patent is subject to a terminal disclaimer.

Measuring device and methods for use therewith