A sound-driving loudspeaker system is achieved with a simple structure and is capable of easily improving acoustic characteristics. The loudspeaker system emits sound by driving a diaphragm panel by an electromechanical acoustic transducer. The loudspeaker system includes a board, the diaphragm panel whose rim is fixedly attached to the board so as to form a space and which has a stiffness lower than that of the board, and the electromechanical acoustic transducer for emitting sound into the space. With this structure, the diaphragm panel is flexed to be vibrated by the sound emitted from the electromechanical acoustic transducer.

1. Field of the Invention
The present invention relates to a loudspeaker system and, more specifically, to a loudspeaker system in which a diaphragm panel is driven by an electromechanical acoustic transducer.
2. Description of the Background Art
Loudspeaker systems in which a diaphragm panel is driven by an electromechanical acoustic transducer have been suggested. One exemplary loudspeaker system employs a scheme in which an electromechanical transducer is directly attached to a diaphragm panel. In another example, a scheme is employed in which a diaphragm panel is acoustically vibrated by an electromechanical acoustic transducer via a space (such a scheme is hereinafter referred to as a sound-driving scheme). Here, the scheme in which the electromechanical transducer is directly attached to the diaphragm panel has several drawbacks. For example, in order to achieve required acoustic characteristics, there is a limitation of the location of the diaphragm panel to which the electromechanical transducer is attached. Therefore, in view of design flexibility of the loudspeaker system, the sound-driving scheme is more advantageous.
FIG. 14 is an illustration showing a basic configuration of a conventional loudspeaker system using the sound-driving scheme. In FIG. 14, 100 denotes a plate-like diaphragm panel. 101 denotes a suspension for supporting the outer rim of the diaphragm panel 100. 102 denotes a frame for fixing the outer rim of the suspension. 103 denotes an acoustic aperture provided on the bottom of the frame 102. 104 denotes an electromechanical acoustic transducer such as to cover the acoustic aperture 103. 105 denotes an enclosed space formed between the diaphragm panel 100 and the electromechanical acoustic transducer 104. In this loudspeaker system, the suspension 101 for supporting the outer rim of the diaphragm panel 100 causes the entire diaphragm panel 100 to perform a piston action for emitting sound. That is, sound emitted from the electromechanical acoustic transducer 104 is led to the enclosed space 105, where air is pressurized to cause the diaphragm panel 100 to vibrate, thereby emitting sound.
It is assumed herein that the diaphragm panel 100 performs a piston action in any frequency band. Under this assumption, an equivalent circuit of the loudspeaker system illustrated in FIG. 14 can be presented as illustrated in FIG. 15. In the equivalent circuit illustrated in FIG. 15, F denotes a driving force of the electromechanical acoustic transducer 104 (driver). Rme denotes a magnetic damping resistance. Cms denotes a compliance of components that support vibrating components of the driver. Mms denotes a mass of the vibrating components in the driver. Rms denotes a mechanical resistance associated with the supporting of the driver. Sd denotes an effective area of a diaphragm of the driver. Furthermore, Cab denotes an acoustic compliance of the enclosed space 105. Rab denotes an acoustic resistance of the enclosed space 105. Cmp denotes a compliance of the suspension 101. Rmp denotes a mechanical resistance of the suspension 101. Mmp denotes a mass of the diaphragm panel 100. Sp denotes an effective vibration area of a diaphragm portion composed of the diaphragm panel 100 and the suspension 101.
As can be known from the equivalent circuit illustrated in FIG. 15, an acoustic transformer is structured based on an area ratio of the effective area Sd of the diaphragm of the electromechanical acoustic transducer 104 with respect to the effective vibration area Sp of the diaphragm portion (Sd/Sp). Therefore, at the time of the operation of the loudspeaker system, an equivalent mass of the diaphragm portion with respect to the electromechanical acoustic transducer 104 is proportional to the square of the area ratio (Sd/Sp). Therefore, if an electromechanical acoustic transducer having a diaphragm area smaller than the diaphragm panel 100 is used, the equivalent mass of the diaphragm panel 100 is small. In this case, even if the diaphragm panel 100 having a large mass is used, the efficiency of the loudspeaker system itself is not degraded.
In the loudspeaker system illustrated in FIG. 14, if a height Tg of the enclosed space 105 is lowered, a reproduction limit frequency in the treble range can be increased. Here, the reproduction-limit frequency in the treble range is defined by the mass Mmp of the diaphragm panel 100 and the acoustic compliance Cab of the enclosed space 105. Also, the acoustic compliance Cab is defined by the capacity and height Tg of the enclosed space 105. Therefore, in order to increase the reproduction-limit frequency in the treble range, the height Tg is lowered, thereby decreasing the acoustic compliance Cab.
FIG. 16 is a graph showing sound pressure frequency characteristics predicted by the equivalent circuit illustrated in FIG. 15. In FIG. 16, the illustrated characteristics can be predicted when the height Tg of the enclosed space 105 is 0.2 (mm), 0.4 (mm), or 0.8 (mm). Conditions for the above prediction are as follows. That is, an electrodynamic loudspeaker whose effective diaphragm area is approximately φ16 (mm) in diameter is used as the electromechanical acoustic transducer 104. Also, a plate of 72 (mm) in height×51 (mm) in width×1 (mm) in thickness made of polycarbonate is used as the diaphragm panel 100. The suspension 101 for use is made of SBR (styrene-butadiene rubber) of 5 (mm) in width×50 (μm) in thickness. As evident from FIG. 16, since the reproduction limit frequency in the treble range is defined by the height Tg of the enclosed space 105, the height Tg has to be lowered in order to increase the reproduction limit frequency in the treble range.
In the above-mentioned conventional loudspeaker system using the sound-driving scheme, a suspension for supporting the outer rim of the diaphragm panel is required. This requirement makes the configuration of the loudspeaker system complicated. Furthermore, the complicated configuration makes it difficult to reduce the size of the loudspeaker system. Therefore, it is difficult to use the conventional loudspeaker system in devices such as portable terminals, which require downsizing and space-savings.
Furthermore, in the conventional loudspeaker system using the sound-driving scheme, it is difficult to improve acoustic characteristics in the bass and treble ranges simultaneously. That is, in the conventional scheme of driving the diaphragm panel by a piston action, the diaphragm panel is required to be high in stiffness and light in weight. However, there is a limitation in order to simultaneously satisfy both of high stiffness and light weight for achieving improvements in the acoustic characteristics. Details are described below.
Descriptions are made below to the fact that lowering the stiffness of the diaphragm panel reduces the sound pressure level. FIGS. 17 and 18 are illustrations showing the results obtained by measuring the characteristics of the loudspeaker system under the same conditions as those of FIG. 16. FIG. 17 is an illustration showing a vibration mode of the diaphragm panel of the conventional loudspeaker system at a frequency of 500 (Hz). FIG. 18 is a graph showing sound pressure frequency characteristics of the conventional loudspeaker system. In FIG. 17, the height Tg of the enclosed space 105 is 0.2 (mm).
FIG. 17 illustrates a vibration mode of the suspension 101 on which the outer rim of the diaphragm panel 100 is mounted. Here, white portions represent a large vibration. As evident from FIG. 17, most of the suspension 101 is greatly vibrated. On the other hand, the diaphragm panel 100 has the outer rim portion being greatly vibrated, and a center portion being slightly vibrated. Therefore, in a bass range at a frequency of 500 (Hz), a separated resonance occurs, that is, the outer rim of the diaphragm panel 100 is greatly vibrated. In other words, in FIG. 17, the diaphragm panel 100 does not perform a piston action, that is, the diaphragm panel is vibrated not as a whole. This is because the stiffness of the diaphragm panel 100 is low. This also means that the equivalent circuit illustrated in FIG. 15 is not applicable. As illustrated in FIG. 18, in practice, the separated resonance in the bass range occurring at the diaphragm panel 100 causes an increase of an acoustic impedance, that is, an acoustic load applied to the diaphragm. As a result, the velocity of the diaphragm is decreased, and the sound pressure level is also decreased. In FIG. 18, a solid line denotes actual measured values of the sound pressure frequency characteristics, while a dotted line denotes predicted values obtained by the equivalent circuit illustrated in FIG. 15. In FIG. 18, the sound pressure level of the measured values is lower than that of the values obtained by the equivalent circuit by approximately 10 (dB).
As described above, when the stiffness of the diaphragm panel is low, the sound pressure level in the bass range is also reduced. In order to solve this problem, the diaphragm panel requires a stiffness to some extent. One way to increase the stiffness of the diaphragm panel is, for example, to configure the diaphragm panel 100 so as to have a sandwich structure, that is, a structure with a core material sandwiched between surface materials attached thereto. Such a sandwich structure of the diaphragm panel 100, however, has several drawbacks. Particularly, the use of the surface materials increases the mass of the diaphragm panel 100, thereby disadvantageously lowering the sound pressure level in the treble range. Furthermore, the sandwich structure of the diaphragm panel 100 is rather a complicated structure, and also increases the thickness of the diaphragm panel 100.
As such, in the conventional sound-driving scheme of causing the entire diaphragm panel 100 to perform a piston action, the stiffness of the diaphragm panel 100 has to be increased in order to improve the sound pressure level in the bass range. In order to improve the treble sound pressure level, on the other hand, the weight of the diaphragm panel 100 has to be reduced. In practice, however, in view of the structure and material of the diaphragm panel, there is a limitation to simultaneous achievement of high stiffness and light weight. Therefore, in the conventional sound-driving scheme, it is difficult to simultaneously achieve improvement in the acoustic characteristics in both the bass and treble ranges.

This patent is subject to a terminal disclaimer.

Loudspeaker system in which a diaphragm panel is driven by an electromechanical acoustic converter

Matsushita Electric Industrial Co., Ltd.


A one-piece stripper retainer for plastic cup shaped strippers with a universal snap-in design that can be used with both older style and newer style punch retainers. The stripper retainer incorporates an anti-rotation heel with a snug fit around a portion of the punch retainer body and clamps to the punch itself. In a second version, the stripper retainer also clamps to the punch itself but lacks the heel. In a third version, the stripper retainer bolts to the punch retainer with a separate threaded screw. In all three versions, the plastic stripper is locked in place by the snap-in feature without any additional clamping force.

The field of the invention pertains to punches and dies for forming holes and depressions in metals. In particular, the invention pertains to devices and accessories for preventing work pieces from adhering to punches during high-speed high production manufacturing.
Examples of modern punch retainers are shown in applicant's previous U.S. Pat. Nos. 5,357,835, 5,410,932 and Des. 351,395. Views of these punch retainers are also shown in FIGS. 1, 2, 8 and 9. Modern punches for certain applications utilize a polyurethane cup that fits over the punch and is attached to the punch retainer by a two-piece metal stripper retainer. The two-piece stripper retainer was developed to provide adequate axial support for the cup. Although inexpensively stamped from sheet steel, the two-piece stripper retainer does not rigidly and accurately retain the polyurethane cup to the punch retainer to the degree desired. In addition, the two-piece stripper retainer will not fit the industries' new smaller footprint ball-lock punch retainer for round shaped punches.


An alternator configured to acquire a motive force from an engine to generate electricity and a capacitor capable of storing therein the electricity generated by the alternator are provided. An electricity consumption amount required during learning is calculated, and a capacitor electricity amount is compared with the calculated electricity consumption amount, and when the capacitor electricity amount is equal to or less than the calculated electricity consumption amount, the alternator is operated to generate electricity until the capacitor electricity amount is increased beyond the calculated electricity consumption amount. On the other hand, when the capacitor electricity amount is greater than the calculated electricity consumption amount, or when the capacitor electricity amount is increased beyond the calculated electricity consumption amount according to electricity generation by the alternator, the learning is performed while using the capacitor electricity without performing electricity generation by the alternator.

Heretofore, along with the progress of automotive electronics, for example, fuel injection control such as fuel injection amount control and fuel injection timing control has been performed by an electronic control system mainly composed of a microprocessor. A characteristic of a fuel injection valve (a relationship between an assignable injection time period to the fuel injection valve and an actual injection amount) for use in the fuel injection control has a variation due to individual differences among fuel injection valves, aging, etc. In this connection, there has been known a technique of learning a characteristic of a fuel injection valve so as to figure out such a variation to contribute to enhancing reliability of engine control, as described in the following Patent Literature 1. Further, the following Patent Literature 2 describes a technique of detecting a rough idling state in which an engine speed during an idling operation of an internal combustion engine unstably fluctuates with respect to a target engine speed.
During learning of a characteristic of a fuel injection valve, it is preferable to maintain an engine in a no-load state. This is because, if a load is applied to the engine, it results in an increase in fuel injection amount, or an increase in torsion of a crankshaft, which is likely to cause deterioration in learning accuracy.
Meanwhile, an engine is equipped with an alternator serving as an electricity generation device configured to be driven by rotation of a crankshaft. The alternator has a large operating resistance (load), wherein the load unpredictable fluctuates depending on an electricity generation amount. Thus, it is desirable to prevent the alternator from being activated during execution of the learning. However, the alternator can be activated during execution of the learning, for the following reason. That is, a fuel injection valve as a target of the learning requires electricity for driving it. Further, a microprocessor for executing the learning also consumes electricity by itself. During execution of the learning, such electricity is supplied by discharging a battery as an electricity source, so that a state of charge (SOC) in the battery is lowered during execution of the learning. Excessive lowering of the SOC accelerates degradation of the battery. Thus, in order to prevent degradation of the battery, a control operation is effected to generate electricity by the alternator during execution of the learning to supply the generated electricity to the battery. For the above reason, the alternator is activated during execution of the learning.
When the alternator is activated during execution of the learning, an operation of the alternator causes an increase in load on the engine, wherein the load unpredictable fluctuates. As a result, the learning accuracy deteriorates.

Controller and control method for engines


An electronic bingo device for use in dispensing bingo cards and tracking the cards for bingo during play. The apparatus is equipped with a conventional computer hardware platform and software tailored to track a bingo game by use of a game key with memory for storing data representative of a set of bingo game data including winning patterns and wild cards used during each game. In addition, a player's allocation of bingo cards are stored on the game key. Bingo cards stored in the device corresponding to the number allocated are used for game play. As the player enters the numbers are called out in the bingo hall. The device monitors each card for bingo.

1. Field of the Invention
The present invention relates to a portable electronic game system and more particularly to a stand-alone electronic bingo game apparatus.
2. Description of the Related Art
Bingo is game of chance in which each player's chances of winning depends upon numbers drawn at random. Players compete in against other using bingo cards prepared with a design of five rows of five squares each for a total of 25 squares. The letters B-I-N-G-O is displayed above the grid, with each letter aligned with a vertical column of squares. A two-digit number generally from 1 to 99, but preferably from 1 to 75, appears in every square of the bingo card except the center square, which is designated as a free play. The game also uses a central source for generating random numbers. The random numbers are drawn from a pool of bingo balls. The number of balls corresponds to the range of numbers available on the bingo card. On each ball are found letters and numbers corresponding to those printed on the bingo cards. Each ball includes one letter from the word bingo and one number from the range of numbers printed on the bingo card. From a conventional air-ball machine or a box, a caller chooses numbers at random one ball at a time and announces the letter and number appearing on the ball. The players with numbers matching the number on the ball called, marks off the number being called using a ink marker called a "dauber". In the basic form of bingo, as soon as five numbers are covered in a straight line either vertically , horizontally or diagonally, the person with the covered numbers calls out "bingo!". Each player that attains "bingo" in a game wins a prize. At the end of each game players turn in their marked cards and must purchase new cards to play another round. Players generally have an opportunity to play more than one bingo card. Often players may attempt as may bingo cards as they have table space available with the idea that the more cards played increases the player's chances of winning bingo. Bingo cards are often sold prepackaged in groups of various denominations. Players can purchase these packaged cards as an added convenience.
With the growth in popularity for the bingo game, more challenging changes have added to the bingo game. First, the basic winning patterns of aligning five numbers on a card either horizontally, vertically or diagonally have been supplemented by a number of complex winning patterns. Some of these winning patterns are as follows:
Postage Stamp where winning numbers are found only in one corner of the array;
Four Corners where winning numbers are found in every corner of the array;
Small Diamond where four winning numbers are found encircling one cell in the array;
Block of Nine where winning numbers are found in a three by three array forming a block of nine numbers;
Crazy T where winning numbers are aligned in a horizontal line and a vertical line to form a "T" shape;
Large Diamond where winning numbers are aligned diagonally encircling a small diamond;
Small Picture Frame where eight winning numbers are found encircling one cell in the array; and
Crazy L where winning numbers are aligned in a vertical line and horizontal line to form an "L" shape.
In addition, some bingo halls are now using "wild numbers" to further add to the complexity of the game. The "wild numbers" are typically called out at the beginning of game play. A "wild number" is identified by the caller before it is drawn. The caller also identifies what characteristic will make the number wild. For example, if the number is even then all even numbers may be marked. Or for example, all numbers sharing the same first digit may also be declared as wild. Other, criteria may be used as well, but it is generally the bingo hall that determines the rules for each game.
Wild card numbers and the winning patterns generally change for each bingo game. In order to achieve "bingo" during any game, the players must know the rules and apply the rules properly during each called number in order to achieve bingo. A problem occurs with players accustomed to playing large numbers of bingo cards. The complexity of tracking several winning numbers for each game combined with the large number of cards played, often increases the chances that a players will miss a possible winning match.
Electronic bingo devices have been developed to help alleviate the problem of tracking large numbers of bingo cards over various patterns; however many of these devices are not well suited for complexities of game play available. While other devices which are well suited for such game play are complex and require computer operators to load the game information before use. One such device is disclosed in U.S. Pat. No. 4,747,600 issued to Richardson which describes a gaming board which includes a communications port used in an electronic bingo system. A computer operator transfers individual game player cards and winning pattern information to the gaming boards from a base station computer. This method has to be performed on each gaming board used in play. The result is added cost and labor to the bingo hall. Another problem with the electronic bingo system is that each game board must be individually connected to the base station in order to be connected. This causes added delay as each player must wait for the operator of the base station to configure their system. Thus, the need exists for a low cost, easy-to-use bingo device that is capable of adapting to the various levels of game play.


A chair having a skeletal frame and a pliable seat and backrest having first and second superposed and interconnected fabrics. The first and second fabrics have looped fabric portions that define opposite side edges of the fabrics. Each of the looped fabric portions in the first fabric contains an elongate flexible member. The skeletal frame has a pair of elongate members that support the seat and backrest. The elongate members on the chair frame have lengthwise extending passageways and longitudinal slots for receiving the looped fabric portions of the first fabric and the elongate flexible members to secure the seat and backrest to the chair frame. The looped fabric portions of the second fabric overlie the elongate members and looped fabric portions of the first fabric to enhance the appearance of the chair. The first fabric substantially supports the tensile forces imposed on the seat and backrest by the weight of a person seated in the chair. The second fabric may be decorated with a printed pattern.

Chairs of the type generally intended for recreational or outdoor use may be made in many different styles using a variety of materials designed to withstand the rigors of such use. Often, these chairs have skeletal frames made of metal tubing, wood, plastic or some other rigid material that can endure the hardships of prolonged exposure to weather and which is durable enough to withstand relatively heavy use. It is also generally desirable that the chair frame be lightweight for easy mobility, yet it must have sufficient rigidity to support the weight of a seated person.
The skeletal chair frame generally defines and supports a seat and backrest that is made of a material adapted to provide a comfortable seating area. Unfortunately, many materials that are well suited for providing a comfortable seating area and which would render adequate service if used in indoor conditions are prone to rapid deterioration from prolonged exposure to ambient conditions. For example, sunlight may cause degradation of some synthetic materials such as vinyl or other plastics, causing them to lose their strength and appearance. Moisture from precipitation or high humidity may cause rot or may promote mildew. Wide daily and seasonal temperature swings cause expansion and contraction of the materials, and freezing temperatures may cause further damage from ice formation.
Prior to the present invention, recreational seating has generally been fabricated in three primary styles which are capable of withstanding the severe demands described above. Many chairs have a seat and backrest formed of multiple straps of material that are stretched laterally across the chair frame. Chairs of this type are colloquially known in the industry as "strap chairs." The strap material used to form the seat of these chairs may be made of solid lengths of pliable vinyl or of relatively narrow segments of webbed material woven from synthetic fibers. Strap chairs have a distinctive appearance due to the plurality of straps extending across the frame and the interstices left open between adjacent straps. Although strap chairs are generally durable, inexpensive to manufacture and light in weight, the seat and backrest cannot readily be decorated with a unitary design as the successive straps are distinct from each other.
A second type of chair uses cushions as the seat and backrest. Chairs of this sort are generally known as "cushion chairs." These cushions are of a conventional type having an outer shell made of a woven or sheet material that surrounds an interior layer of padding material. One cushion may be used as the seat and another cushion as the backrest, or a single cushion may be used as both the seat and backrest.
The cushions are supported from beneath by the chair frame, which must have straps, metal plates, bars or the like extending beneath the seat and behind the backrest to support the cushion. Usually, the cushion rests independently on the chair frame and can be easily removed from the frame for storage inside. Because the padding material is encased within a layer of sheet or woven material, cushions are readily adapted for surface decoration. However, cushion chairs are generally heavier and more expensive to manufacture than strap chairs due to the more complex frame construction necessary to underlie the cushion.
A third type of recreational seating is known as the "sling chair." Sling chairs have a skeletal frame that is commonly made of extruded metal tubing that is assembled into a rigid frame that defines the lateral edges of a seating area. Sections of tubing having channels formed therein are positioned along the lateral sides of the seating area, generally within the exterior confines of the frame. In sling chairs, the seat and backrest are formed by a relatively heavy web of material that is tautly stretched across the lateral sides of the frame. Generally, the lateral edges of the webbed sling material are securely fastened to the chair frame by means of acrylic rods held within hemmed pockets formed in the edges of the sling material. These rods and the hemmed portions containing them are retained within the channels formed by the tubing.
Sling seats have an attractive, modern appearance, are lightweight and may be relatively inexpensive to construct. However, because the sling seating must withstand relatively high tensile forces in order to support the weight of a person seated in the chair, the sling fabric is generally made of a relatively heavy woven material. The sling fabric must also withstand prolonged expose to outdoor conditions. Commonly, the material of choice is a relatively rough weave of vinyl or a blend of vinyl and acrylic monofilament fibers. These fabrics are not readily susceptible to application of pleasing printed designs such as a floral pattern or the like. Sling seating has a relatively rough surface and lacks any cushioning material to enhance the comfort of a person seated on the chair. Also, the joinder of the seat and backrest fabric and the chair frame is readily visible and may present an unfinished appearance.
In light of the aforementioned deficiencies, it is an object of the present invention to provide a new sling chair that has a smooth seating surface which may be imprinted with a decorative pattern.
Another object of the present invention is to provide a sling chair that has a layer of cushioning material to increase the comfort of a person seated on the chair.
A further object of the present invention is to provide a sling chair in which the joinder between the seat and backrest and the chair frame is not readily visible so as to present a pleasing, finished appearance.
Yet another object of the present invention is to provide a lightweight recreational chair having padding and a surface which may be imprinted with a decorative pattern that will withstand the rigors of recreational use.


An improved multistage intelligent database search method includes (1) a prefilter that uses a precomputed index to compute a list of most “promising” records that serves as input to the original multistage search method, resulting in dramatically faster response time; (2) a revised polygraph weighting scheme correcting an erroneous weighting scheme in the original method; (3) a method for providing visualization of character matching strength to users using the bipartite graphs computed by the multistage method; (4) a technique for complementing direct search of textual data with search of a phonetic version of the same data, in such a way that the results can be combined; and (5) several smaller improvements that further refine search quality, deal more effectively with multilingual data and Asian character sets, and make the multistage method a practical and more efficient technique for searching document repositories.

1. Field of the Invention
This invention relates to methods of database searching, and more particularly to improvements to a highly error-tolerant yet time-efficient search method based on bipartite weighted matching.
2. Description of Related Art
Inexact or "fuzzy" string comparison methods based on bipartite matching are highly appropriate for finding matches to users'queries in a database, despite errors and irregularities that often occur in both queries and database records. Given the massive growth in both the quantity and availability of information on the world Internet, and the dependence of corporations, government agencies, and other institutions on accurate information retrieval, a pressing need exists for efficient database search methods that are highly error-tolerant, and that also function well on the vast quantity of "semi-structured" (loosely formatted) textual data that is available to users of the Internet and corporate intranets.
Such an error-tolerant database search method is the subject of U.S. Pat. No. 5,978,797 by Peter N. Yianilos, assigned to NEC Corporation, Inc., entitled "Multistage Intelligent String Comparison Method." The heart of that invention is a software function that compares two text strings, and returns a numerical indication of their similarity. To approximate a more "human" notion of similarity than other approaches to inexact comparison, this function utilizes a bipartite matching method to compute a measure of similarity between the two strings. String comparison using bipartite matching is disclosed in U.S. Pat. No. 5,841,958 by Samuel R. Buss and Peter N. Yianilos, assigned to NEC Corporation, Inc. U.S. Pat. No. 5,978,797 discloses the application of bipartite matching-based string comparison to database search, in which the similarity of each database string to a query is computed based on an optimal weighted bipartite matching of characters and polygraphs (short contiguous stretches of characters) common to both database record and query.
This "multistage" search method operates on a database consisting of records, each of which is viewed simply as a string characters, and compares each record with a query consisting of a simple free-form expression of what the user is looking for. The comparison process occurs in three stages, in which the earlier stages are the most time-efficient and eliminate many database records from further consideration. The final output is a list of database records ranked by their numerical "similarity" to the query. The multistage approach, which applies increasingly stringent and computationally intensive versions of bipartite matching to smaller and smaller sets of records, makes it possible to compare the query with thousands or hundreds of thousands of database records while still delivering acceptable response time. The result is that in almost all cases, the output list of database records is the same list that would be produced by applying the final and most discerning (but slowest) process stage to the entire database.
A number of weaknesses and unexploited potentialities are associated with the original multistage database search method disclosed in U.S. Pat. No. 5,978,797:
ORIGINAL METHOD WAS NOT SCALABLE TO LARGE DATABASES. A major weakness of the original method is that it must examine every character of every record in a database in order to determine a list of records most similar to a query. The original method is thus time-efficient only for small to medium-sized databases, consisting of tens or hundreds of thousands of records. The method is not scalable to large databases.
ORIGINAL METHOD DID NOT TAKE ADVANTAGE OF THE BIPARTITE GRAPH TO PROVIDE VISUAL FEEDBACK TO THE USER. The original method used the total cost of the bipartite matching of characters and polygraphs between query and database record as a measure of their similarity. This is a single number, which suffices for the ranking of records in the output list. However, the bipartite graph that is computed by the final filter stage contains information that can be used to provide sophisticated feedback to the user regarding the "matching strength" of each character in a database record.
ORIGINAL METHOD WRONGLY WEIGHTED MATCHING POLYGRAPHS OF DIFFERENT LENGTHS. The three stages of the multistage method compute bipartite matchings of single characters and polygraphs common to a query and a database record. Since a matching 6-graph (stretch of 6 characters) is clearly more significant than a matching 3-graph or 2-graph or 1-graph (single character), the original method adopted a weighting scheme that weighted matching polygraphs in direct proportion to their length. This approach was mistaken, and frequently resulted in a poor similarity ranking.
A more correct analysis of bipartite matching of polygraphs shows that longer polygraphs naturally receive greater weight in the overall matching due to the greater number of shorter polygraphs they contain, which are also included in the matching.
This natural weighting effect due to polygraph inclusion is already so pronounced that a correct weighting scheme should seek to attenuate it, not further magnify it, as did the original method. Under the original weighting scheme, database records containing many short matching polygraphs but no very long ones, tended to be strongly outranked by records that happened to contain a single long matching polygraph. This frequently resulted in clearly less-similar records (in the judgment of a human being) outranking more-similar records.
ORIGINAL METHOD INCORPORATED NO KNOWLEDGE OF CHARACTER PHONETICS. Bipartite matching operating directly on English or other natural-language strings does not capture points of similarity that depend upon knowledge of character phonetics, e.g., that in English "ph" usually represents the same sound as "f". While a typographic error in a query or database record generally substitutes an unrelated symbol for the correct one, misspellings often substitute a symbol (or symbols) that sound equivalent to the correct symbol. The original method incorporated no such language-specific phonetic knowledge, which frequently resulted in degraded search quality.
In summary, the original multistage search method does not scale to large databases, does not exploit the bipartite graph to provide any visual feedback to the user on which characters match his query, employed a faulty character and polygraph weighting scheme, and does not capture points of similarity with a query that depend on a knowledge of phonetics.

Multistage intelligent database search method


A compressor or expander has a variable-volume chamber with a heat exchanger located inside the chamber. The heat exchanger can have a helical structure and may be connected between walls of the chamber that move relative to one another during compression or expansion. The heat exchanger comprises a passage containing a heat exchange fluid. The heat exchange fluid may add heat to or remove heat from a gas being expanded or compressed. Embodiments may provide isothermal or near isothermal compression or expansion.

Gases are compressed for a wide range of applications. For example, compressed gases may be used to store energy, run tools or other pneumatic equipment, provide compact storage of gases, provide conditions to promote chemical reactions and the like. Refrigeration systems and heat pumps also typically include compressors for compressing gases. As air (or any other gas) is compressed, work is being done on the gas. Conservation of energy dictates the energy from the work cannot be lost. In adiabatic compression (adiabatic means there is no heat flow in or out of the system) a significant proportion of the energy from the work done to compress the gas goes into increasing the gas temperature. The end result is hot, compressed gas. Most current technologies for gas compression perform compression that is adiabatic or nearly so.
Many gases behave to a good approximation as ideal gases which obey the ideal gas law:PV=nRT  (1)where P is pressure, V is volume, n is the number of molecules of gas, R is a constant and T is the temperature. When a gas is compressed under adiabatic conditions (no heat flows into or out of the gas during compression) the entropy of the gas remains constant. Therefore, for an ideal gas under adiabatic compression PVγ is constant, where γ is the heat capacity ratio for the gas and so, for an ideal gas, T∝1/V(γ−1), γ generally has a value in excess of 1 so that a decrease in volume, as occurs when a gas is compressed, results in a corresponding increase in the gas temperature. For dry air, γ has a value of about 1.4.
The heating which results from adiabatic compression can lead to inefficiencies because hot compressed gas typically loses heat to its environment. Where a gas is compressed adiabatically, allowed to cool to ambient temperature and subsequently allowed to expand to do work the amount of energy taken to compress the gas is typically about twice the amount of work done. Consequently the overall efficiency of such a round trip compression expansion is only about 50%.
Various attempts have been made to provide compressors that operate on an isothermal cycle. In isothermal compression, the gas being compressed is cooled as it is compressed so that the temperature of the gas remains essentially constant. Such systems have not been widely adopted.

Isothermal machines, systems and methods


A 4-wheel drive vehicle has a driving force control method in which a portion of a driving force for front wheels is distributed to rear wheels through clutches. In a 4-wheel drive state in which a driving force T.sub.p is distributed to rear wheels, for example, if the vehicle is turned leftwards to generate a difference W.sub.R -W.sub.L between left and right rear wheel speeds, it is ensured that a driving force T.sub.R distributed to the right rear wheel, which is an outer wheel during turning of the vehicle, is larger than a driving force T.sub.L distributed to the left rear wheel, which is an inner wheel during turning of the vehicle, thereby providing an enhancement in turning performance. As the difference W.sub.R -W.sub.L between the left and right rear wheel speeds is increased as a result of decreasing of the turning radius of the vehicle, the driving force T.sub.P (=T.sub.L +T.sub.R) distributed to the rear wheels is decreased to avoid an increase in travel resistance. Thus, it is possible to prevent the occurrence of problems such as a deterioration of specific fuel consumption, an abnormal sound generated in a drive system and an increase in the load of the drive system due to an increase in travel resistance during turning of the vehicle.

1. Field of the Invention
The present invention relates to a driving force control method in a 4-wheel drive vehicle in which the driving force of an engine is transmitted directly to one of the front and rear wheels (that is, the main driving wheels) and through driving force varying means to the other of the front and rear wheels (that is, the auxiliary driving wheels).
2. Description of the Related Art
A driving force control method in a 4-wheel drive vehicle, in which a portion of a driving force for front wheels driven by an engine is distributed to left and right rear wheels at a predetermined ratio, is conventionally known and has already been proposed in Japanese Patent Application No. 7-295762 by the present applicant.
In the above known driving force control method, if the front wheel speed is higher than the rear wheel speed as a result of slipping of the front wheel at the starting of the vehicle or during sudden acceleration of the vehicle, a portion of the driving force for the front wheel is distributed to the left and right rear wheels to bring the vehicle into its 4-wheel drive state. If a speed difference is generated between left and right rear wheel speeds by turning of the vehicle, it is ensured that the amount of driving force distributed to outer wheels during turning of the vehicle is larger than the amount of driving force distributed to inner wheels during turning of the vehicle, thereby providing an enhancement in turning performance.
If a larger amount of driving force is distributed to the rear wheels when such vehicle is being turned in its 4-wheel drive state, the travel resistance is increased and hence, there is a possibility that problems occur such as a deterioration of specific fuel consumption, an abnormal sound generated in the drive system, an increase in load of the drive system and the like.

Driving force control method in 4-wheel drive vehicle


The present invention is an attenuated mutant strain of Streptococcus pneumonia that has a mutation in the FtsY gene. Vaccines, kits and methods for protecting a subject against Streptococcus pneumonia disease or colonization using the attenuated mutant strain are also provided.

Acute otitis media (AOM) is one of the most common infectious diseases of children and the most common infection for which antibiotics are prescribed in the United States (Daly, et al. (1999) Pediatrics 103:1158-1166; McCaig, et al. (2002) JAMA 287:3096-3102). Streptococcus pneumoniae remains one of the most prevalent causes of AOM even after the advent of the heptavalent conjugate vaccine (Coker, et al. (2010) JAMA 304:2161-2169). Vaccination is viewed as a critical method of prevention but has been largely unsuccessful in changing the incidence of AOM. The 23-valent polysaccharide vaccine does not elicit antibodies in children under age 2 and is not protective against AOM in any age group. The heptavalent conjugate pneumococcal vaccine (PREVNAR) is highly protective against invasive disease from birth but again fails to significantly impact the rate of AOM (Eskola, et al. (2001) N. Engl. J. Med. 344:403-409). The high effect of AOM on children's medical care and the absence of effective preventive intervention indicates that new vaccine concepts are urgently needed.
Otitis media caused by S. pneumoniae is a significant medical burden in children. Although the advent of the pneumococcal polyvalent conjugate vaccine PREVNAR (PCV7) has decreased the overall burden of pneumococcal disease, the suboptimal mucosal immune response elicited by this vaccine does not provide effective protection. Even with vaccination, AOM is the leading cause of pediatric physician visits and is responsible for a majority of the antibiotics prescribed to young children (Daly, et al. (1999) supra; McCaig, et al. (2002) supra). Furthermore, as is the risk with all polysaccharide capsule-based vaccines, the risk of an increasing burden of non-vaccine serotypes remains problematic and quickly emerges (Block, et al. (2004) Pediatr. Infect. Dis. J. 23:829-833; Eskola, et al. (2001) supra). This underscores the importance of development of new vaccination strategies that would confer cross-serotype protection as well as a greater understanding of host mucosal immunity.
Studies in animal models have demonstrated that the intranasal route of vaccination is particularly effective at inducing immune responses in the nasal passage and middle ear for protection against AOM (Sabirov & Metzger (2006) Vaccine 24:5584-5592). Further, application of live, attenuated S. pneumoniae mediates a potent, serotype-independent mucosal and humoral immune response that was protective against subsequent invasive challenge (Roche, et al. (2007) Infect. Immun. 75:2469-2475). These studies suggest that a vaccine effective against AOM should optimally be live, attenuated, and be given intranasally. However, these vaccines may not be optimal because they were generated by deleting several important, highly immunogenic virulence factors, which are currently being developed as components of protein-based vaccines against S. pneumoniae. Therefore, there is a need in the art for alternative vaccines for the prevention of pneumococcal disease.


A cooling and gas dehumidifying system comprising a cooling circuit in which a thermal fluid is circulated. The system further comprises a cooling arrangement arranged in the cooling circuit and configured to cool the thermal fluid flowing therethrough. A consumer gives up heat energy to the thermal fluid flowing through the cooling circuit. A gas dehumidifier having a heat exchanger arrangement is configured to be thermally coupled in a gas dehumidifying operating state with the thermal fluid flowing through the cooling circuit downstream of the cooling arrangement and having a first temperature, and thereby give up heat energy to the thermal fluid, and to be thermally coupled in a de-icing operating state with the thermal fluid flowing through the cooling circuit downstream of the consumer and having a second temperature, and thereby absorb heat energy from the thermal fluid, the second temperature being higher than the first temperature.

In regenerative fuel cell systems, a fuel cell serves to convert hydrogen and oxygen into water and thereby generate electric current. An electrolyzer located downstream of the fuel cell splits the water produced by the fuel cell into the gases hydrogen and oxygen again. These gases are then fed back into the fuel cell, where they are again used to generate current. During operation, the fuel cell and the electrolyzer must be cooled. Therefore, in a regenerative fuel cell system, the fuel cell and the electrolyzer are arranged in a cooling circuit in which a thermal fluid is circulated. As the thermal fluid flows through the fuel cell and the electrolyzer, it absorbs heat energy. Cooling of the thermal fluid takes place in a cooling arrangement arranged in the cooling circuit.
In order to achieve high efficiency of the fuel cell, the gases fed to the fuel cell must have a particularly high degree of dryness, that is to say a very low water content (ideally a water content equal to zero). Therefore, regenerative fuel cells are conventionally equipped with a gas dehumidifier which serves to dehumidify the gases used for current generation in the fuel cell before they are fed into the fuel cell. When gases are dried or dehumidified, the temperature of the gas is lowered so that it falls below the dew point of water. The water contained in the gas can thereby be deposited as condensation water. The further the temperature is lowered, the dryer the gas becomes. Cooling of the gas is conventionally carried out by means of a corresponding heat exchanger which extracts heat energy from the gas.
A particularly high degree of dryness is achieved when the gas to be dried is cooled in the gas dehumidifier to below the freezing point of water. However, this has the result that the water that has condensed out freezes in the heat exchanger, for example on a cold wall of the heat exchanger or in the form of ice crystals which are precipitated from the gas. However, the deposition of ice crystals in the heat exchanger results in increasing narrowing of the flow cross section of the heat exchanger. Furthermore, the layers of ice growing on the walls of the heat exchanger increasingly reduce the performance of the heat exchanger. It is therefore necessary when operating a gas dehumidifier to regularly de-ice the heat exchanger of the gas dehumidifier. In most cases, this is carried out by heating the heat exchanger. For example, a cooling air stream can be replaced by a hot air stream which heats the wall of the heat exchanger on which a layer of ice has formed, so that the ice is melted.

Cooling and gas dehumidifying system, transport means, and method for operating a cooling and gas dehumidifying system


According to one embodiment, an apparatus includes a first processing unit operating according to a first clock, a second processing unit operating according to a second clock running separately from the first clock, and a synchronization controller coupled to the first communication unit and the second communication unit. The synchronization controller is configured to (i) cause the first communication unit to generate a first indication of time at which the first processing unit transmits a signal to the second processing unit, according to the first clock, (ii) cause the second processing unit to generate a second indication of time at which the second processing unit receives the signal, according to the second clock, and (iii) determine an offset between the first clock and the second clock based on the first indication of time and the second indication of time.

The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
When communication devices exchange data over wired or wireless communication channels, the medium through which the data propagates, as well as processing at intermediate or endpoint communication devices, introduce various propagation delays to the data exchange. For example, an Ethernet link connecting a pair of communication devices typically delays a communication frame by several microseconds, and the propagation delay generally depends on the length of the Ethernet link. On the other hand, a network router that receives a frame, processes the received frame, and further transmits the frame can introduce a much longer delay, typically measured in milliseconds.
Some communication protocols specify techniques for transmitting time stamp information for data units. However, a transmitting device and a receiving device may have clocks that were started at different times and that run at different rates. Accordingly, standards have been developed to allow communication devices to exchange timing and synchronization information. In particular, the Institute for Electrical and Electronics Engineers (IEEE) 802.1AS Standard specifies a protocol and procedures for synchronizing Local Area Networks (LANs). Today, Ethernet ports are synchronized using the IEEE 802.1AS Standard and the IEEE 802.3af ("Power over Ethernet") Standard. As another example, wireless ports are synchronized using the IEEE 802.1AS Standard and the IEEE 802.11v Standard, which specifies configuration techniques for client devices connected to wireless networks.

Method and apparatus for communicating time information between time aware devices


In an apparatus for generating and managing production processing structure in a production management system of a factory, the structure of factory made up of the names or other identifiers of process points obtained by subdividing the factory production line is hierarchically registered in the storage device of the management computer (server; S200), the terminal computers and devices used in production are registered as terminal devices (S202), and tasks (from among tasks generated in advance and stored in the disk of the management computer) for achieving the operation or processing to be implemented at the process points are selected for each process point and registered in the order of execution (S204), while linking the terminal devices with definition information that correlates them, once the terminal computers are activated, the registered tasks are executed by the management computer (server) based on the definition information thus registered, so that the production record information is accumulated, production instructions are distributed to the devices based on the accumulated production record information, such that the product is produced. With this, the number of man-hours and the costs of developing the production management system in building a factory can be significantly reduced, and the turnaround time can be shortened.

Factories are often built rapidly in the manufacturing industry to accommodate expanded production. However, since the processing at individual process points has been conventionally developed on a case-by-case basis according to the production process of the factory newly built, this has led to overlapping of development costs. This has been the same when updating the production management system of an existing factory.
In view of this drawback, a technique is disclosed in Japanese Laid-open Patent Application No. 9-267239 relating to the management of product information, wherein the technique is proposed for the comprehensive, waste-free management of information concerning the production or manufacture of products and parts (components).
However, this prior art merely proposes designing process points for producing a product and generating an operational standard, and makes no suggestions on generation and management of production processing structure in the factory production management system.

Generation/management apparatus of production processing structure in factory production management system


A connector which is capable of preventing crosstalk from occurring when a plurality of pairs of differential signal transmission contacts are arranged in a horizontal row. A housing holds a plurality of connector modules with a gap between adjacent ones thereof. Each connector module is comprised of a plate-shaped holding member, a plurality of first signal contacts held on one surface of the holding member, and a plurality of second signal contacts held on the other surface of the holding member. Positions of the respective first signal contacts of the plurality of connector modules, and positions of associated ones of the second signal contacts of the connector modules are made approximately coincident with each other in the direction of the height of the housing, respectively.

1. Field of the Invention
This invention relates to a connector, and more particularly to a connector suitable for transmission of differential signals.
2. Description of the Related Art
Conventionally, there has been proposed a connector assembly provided with a header and a receptacle (see e.g. Japanese PCT application translation Publication No. 2005-516375).
The header includes a header-side insulating housing, a plurality of pairs of header contacts, and a plurality of ground shield contacts. The header-side insulating housing has a base portion and a pair of side walls. The base portion is substantially plate-shaped. The pair of side walls are each substantially plate-shaped, and are connected to side portions of the base portion.
The plurality of pairs of header contacts form a plurality of pairs of differential signal transmission contacts, and are arranged in matrix on the base portion of the header-side insulating housing. Each header contact includes a connecting portion and a contact portion. The connecting portion is connected to a first circuit board, which forms one object to be connected.
The plurality of ground shield contacts are arranged on the base portion of the header-side insulating housing such that they are each adjacent to associated ones of the pairs of header contacts, respectively. Each ground shield contact includes a plate portion and a connecting portion. The plate portion is opposed to an associated one of the pairs of header contacts. The connecting portion is connected to a ground of the first circuit board.
The receptacle includes a receptacle-side insulating housing and a plurality of module terminals.
The receptacle-side insulating housing is substantially in the form of a casing, and includes a plurality of slots. The slots receive the module terminals whereby the module terminals are held by the receptacle-side insulating housing.
The module terminals each include an overmolded portion, a plurality of pairs of receptacle contacts, and a shield.
The overmolded portion includes a pair of insulating layers and a front edge. The pair of insulating layers are each substantially plate-shaped, and are opposed to each other with a space therebetween. The front edge is connected to front ends of the pair of insulating layers. In the front edge, openings are formed at equally-spaced intervals.
Each receptacle contact includes a contact portion, a press-fit portion, and an intermediate portion. The contact portion is formed at one end of the receptacle contact, and protrudes from the overmolded portion via an associated one of the openings formed in the front edge of the overmolded portion, until the contact portion comes into contact with an associated one of the pairs of header contacts of the header. The press-fit portion is press-fitted into a through hole of a second circuit board, which is the other object to be connected, and is connected to the second circuit board. The intermediate portion connects the contact portion and the press-fit portion. The intermediate portion is accommodated in the space of the overmolded portion.
The shield is substantially plate-shaped, and includes contact portions. The contact portions are each brought into contact with a plate portion of an associated one of the ground shield contacts of the header. The shield is mounted on an outer surface of one of the insulating layers of the overmolded portion.
When the receptacle-side insulating housing that holds the module terminals of the receptacle mounted on the second circuit board is inserted into the header-side insulating housing of the header mounted on the first circuit board, the contact portions of the receptacle contacts of the module terminals are brought into contact with the associated contact portions of the header contacts, and contact portions of the shields of the module terminals are brought into contact with the associated plate portions of the ground shield contacts of the header. As a consequence, signal transmission lines of the first circuit board, and signal transmission lines of the second circuit board are connected by the header contacts and the receptacle contacts, and the grounds of the first circuit board and grounds of the second circuit board are connected by the ground shield contacts and shield contacts.
According to the above-described connector, in the module terminals, the plurality of pairs of receptacle contacts, which form the plurality of pairs of differential signal transmission contacts, are arranged along the direction of the height of the receptacle-side insulating housing (direction parallel to the direction of the thickness of the second circuit board on which the module terminals are mounted). That is, the differential signal transmission contacts that form pairs are arranged in so-called vertical rows. However, when the pairs of differential signal transmission contacts are arranged in vertical rows, there arise problems such as generation of a skew and miss matching of differential impedance. Therefore, when differential signals are transmitted in a high frequency band, it is more advantageous to arrange the receptacle contacts, which form pairs of differential signal transmission contacts, along the direction of arrangement of the module terminals (arrange them in so-called horizontal rows).
To arrange the pairs of differential signal transmission contacts in horizontal rows, it is required to eliminate the shields of the module terminals. However, if the shields are eliminated, a gap is formed between each pair of differential signal transmission contacts, which weakens the connection between the pair of differential signal transmission contacts, whereby the degree of togetherness thereof makes no difference from the degree of togetherness of each differential signal transmission contact as one of each pair and each differential signal transmission contact as one of each another pair adjacent to the pair in the horizontal row. This causes crosstalk between one pair of differential signal transmission contacts and another pair of differential signal transmission contacts adjacent to the one pair.

Connector having a plurality of connector modules and a housing that holds said plurality of connector modules with a gap between adjacent ones thereof

Japan Aviation Electronics Industry Limited


A monitoring service receives, from a variety of hardware components of a set of computer systems, binary signals indicative of operation of these components. The monitoring service determines, based at least in part on these signals, a set of beat frequencies for pairings of hardware components of the set of computer systems. The monitoring service uses this set of beat frequencies, as well as information included in a profile for the set of computer systems, to determine whether there is any indication of anomalous behavior in operation of the set of computer systems. If so, the monitoring service generates one or more alerts indicating the anomalous behavior.

Monitoring services often evaluate data from a variety of computer systems and hardware components of these computer systems to identify anomalous signals that may serve to indicate an issue with these computer systems or hardware components. However, identifying anomalous signals from a large amount of data obtained from these computer systems and hardware components presents various challenges. For instance, for modern monitoring services, it may be difficult to determine which data streams are important, how they relate to each other, and determine what in the data streams indicate an anomaly. Additionally, in order to reduce the impact of these anomalies, the monitoring services need to be able to identify anomalies in an expeditious manner.

Computer systems monitoring using beat frequency analysis


A biCMOS device including a bipolar transistor and a Polysilicon/Insulator/Polysilicon (PIP) capacitor is disclosed. A biCMOS device may have a relatively low series resistance at a bipolar transistor. A bipolar transistor may have a desirable amplification rate.

A biCMOS device may have high speed, low power consumption, and high integration. A biCMOS device is a device (e.g. a chip) that includes both a bipolar transistor and a CMOS transistor. A biCMOS device may have low-power consumption characteristics and high-integration characteristics of CMOS transistors and high-speed switching characteristics and a high-current driving capabilities of bipolar transistors.
There is a variety of bipolar transistor manufacturing methods suitable for the biCMOS technology. These methods may be optimized to be compatible with CMOS transistor manufacturing methods, while maintaining high-speed switching characteristics and high-current driving capabilities. It may be desirable to integrate a Polysilicon/Insulator/Polysilicon (PIP) capacitor on a biCMOS device adjacent to a bipolar transistor. Integrating both a bipolar transistor and a PIP capacitor on a biCMOS device may be accomplished by a high-integration technique.
Example FIGS. 1A to 1D are cross-sectional views illustrating a method of manufacturing a biCMOS device having a bipolar transistor and a PIP capacitor. As illustrated in FIG. 1A, P-type semiconductor substrate 10 may include PIP capacitor region A and bipolar transistor region B. Semiconductor substrate 10 may include buried layer 12 (e.g. doped with an N-type material) formed in bipolar transistor region B. An epitaxial layer (not shown) may be formed on buried layer 12. First well region 14a (e.g. doped with N-type material) and second well region 14b (e.g. doped with P-type material) may be formed adjacent to each other within a epitaxial layer (not shown).
Field insulating layer 16 may be formed over surfaces of PIP capacitor region A and bipolar transistor region B. First polysilicon layer 18 may be formed over field insulating layer 16. A photoresist layer (not shown) may be formed over first polysilicon layer 18. Mask pattern 19 (e.g. for ion implantation) may be formed from a photoresist layer.
As illustrated in FIG. 1B, an ion implantation process using the mask pattern 19 may be performed by implanting ions into exposed areas of first polysilicon layer 18 to form doped first polysilicon layer 18a. As illustrated in FIG. 1C, mask pattern 19 may be stripped. First polysilicon layer 18 may be patterned so that only doped first polysilicon layer 18a remains. First polysilicon layer 18a may become a lower electrode of a PIP capacitor. Capacitor dielectric layer 20 and upper electrode 22 may be sequentially formed on doped first polysilicon layer 18a.
As illustrated in FIG. 1D, collector region 28 may be formed by doping a region of first well region 14a with N-type material. Emitter region 26 may be formed by doping a region of second well region 14b with N-type material. Base region 24 may be formed by doping a region of second well region 14b with P-type material. Base region 24 and emitter region 26 may be isolated from each other. Buried layer 12 and first well region 14a may work with collector region 28 in a bipolar transistor. Second well region 14b may work with base region 24.
A biCMOS device (e.g. a chip including a CMOS transistor and a bipolar transistor) may include the structure illustrated in FIGS. 1A through 1D. The concentration of N-type material in first well region 14a may be relatively low compared to a device that does not integrate CMOS transistors with bipolar transistors. Accordingly, it may be difficult to form a bipolar transistor having an adequate high amplification rate if the series resistance of collector region 28 is relatively high.

BiCMOS device and method of manufacturing a biCMOS device


A platinum film orientation-controlled to (111), (200) and/or (220) is provided by depositing the platinum film under an atmosphere containing an oxygen component such as O2, O3, N2O , N2+O2, or mixtures thereof as well as an inert gas (Ar, Ne, Kr, or Xe) on a substrate heated to a temperature ranged from room temperature to 700xc2x0 C., and annealing to remove the gases introduced into the platinum film during the deposition thereof. The platinum film formed in this process has excellent electrical conductivity (resistivity is lower than 15 xcexcxcexa9-cm), good enough adhesion strength to be used for electronic devices, and does not show hillocks, voids or pinholes.

This application claims priority from commonly-assigned Republic of Korea Application Serial No. P97-17209 (filed May 6, 1997) and Serial No. P97-17211 (filed May 6, 1997).
The present invention relates to a technique for depositing a platinum film, which is used as a bottom electrode for memory cells or film sensors, and to a method of manufacturing such a film, particularly to a platinum film, which is deposited under an atmosphere containing an oxygen component (O2, O3, O2+N2, N2O, or mixtures thereof) together with an inert gas (Ar, Ne, Kr or Xe) so that its orientation and microstructure can be controlled, and to an electronic device comprising such a platinum film as an electrode and a method of manufacturing the electronic device. In the below description, oxygen component means O2, O3, O2+N2, N2O, or mixtures thereof. More particularly, the present invention relates to a technique improving characteristics of a platinum film in the course of manufacturing the platinum film used as a bottom electrode, wherein a preferred orientation of the platinum film is controlled toward a predetermined direction(s) and the platinum film is controlled to have a microstructure without any defects such as hillocks, pinholes and pores to be sufficiently useful as an electrode for memory cells, or ferroelectric sensor devices.
Semiconducting, dielectric, ferroelectric, superconductive and magnetic ceramic materials, used in electronic devices tend to become thinner in line with the trends of miniaturization, high-density integration and functional elevation of electronic ceramic parts or devices. Therefore, thin film type ceramic parts have been widely used in electronic industries. The substrates used for thin film type ceramic parts can be classified into three types. The first type comprises single crystal silicon generally referred to as silicon wafers. The second type comprises the other single crystals such as MgO, SrTiO3 or Al2O3. The third type comprises polycrystal materials such as alumina or diamond. Among them, silicon wafers have been widely used in the conventional manufacturing processes of various types of electronic devices such as memory devices, or sensor devices.
Polysilicon has been widely used as a bottom electrode material in the conventional memory cells without any critical problems. However, it is generally accepted that polysilicon cannot be used any more as a bottom electrode to manufacture DRAMs (Dynamic Random Access Memories) with over 1 Gigabit and FRAMs (Ferroelectric Random Access Memories) which is a new type of non-volatile memory, because high dielectric or ferroelectric oxide thin films such as perovskite structure oxides, bismuth-layered perovskite structure oxides, tungsten-bronze type structure oxide, ReMnO3 (Re: rare-earth element), and BaMF4 (M: Mn, Co, Ni, Mg, Zn), are used on FRAMs, on DRAM devices requiring high degree of integration over 1 Gigabit, or around the core part of all types of oxide thin film sensors or actuators. That is, forming such high-dielectric oxide films requires an oxidation atmosphere and high temperature (higher than 500xc2x0 C.), which may cause problems relating to the polysilicon. For example, if polysilicon is employed as the bottom electrode in a DRAM cell using high-dielectric material for a capacitor, serious problems may occur due to oxidation of the polysilicon under the high temperature (over 500xc2x0 C.) and oxidation atmosphere during formation of the high-dielectric oxide thin films. For this reason, platinum is being investigated for use in place of polysilicon as an electrode of a memory cell employing a high-dielectric or ferroelectric oxide, because platinum is stable under high temperature and an oxidation atmosphere.
However, depositing platinum thin films by means of conventional methods has been known to pose a number of problems. First, the interface between an insulating oxide layer and the platinum layer does not allow chemical bonding, thereby weakening the adhesion strength between the platinum film and the substrate. One of the attempts that has been made to solve this problem is using an adhesion layer between a platinum layer and an insulating oxide layer. A thin film composed of any one or two of Ta, Ti, TiN or W has been formed on an insulating oxide layer before depositing a platinum thin film so that the thin film composed of any one or two of Ta, Ti, TiN or W serves as an adhesion layer between the insulating oxide layer and the platinum film.
However, employment of this method is known to not only complicate the process of forming a bottom electrode but also generate additional problems. In particular, oxygen gas introduced during the post-annealing or high-dielectric/ferroelectric oxide film depositing process can diffuse through voids formed between grain boundaries in the platinum film. Because the grains of the platinum films deposited by conventional processes have vertical columnar structures with inter-columnar voids, oxygen introduced from the above-mentioned process can easily diffuse through the platinum film to the adhesion layer. The oxygen gas diffused through the platinum film then oxidizes the adhesion layer and forms an oxidized insulation layer such as TiO2 and Ta2O5 between the substrate and the platinum film. Consequently, the function of the platinum film as an electrode can become deteriorated or even lost. In particular, if the adhesion layer is formed from TiN, N2 gas is produced while an oxidized layer of TiO2 is formed on the surface of TiN layer, and the N2 gas can cause the platinum film to expand and become released from adhesion layer. This phenomenon is known as xe2x80x9cbuckling.xe2x80x9d
In a conventional depositing method of a platinum thin film, hillocks, pinholes or pores are formed on the platinum film after annealing treatment or deposition of an oxide film. These hillocks, pinholes or buckling cause either shorting of the circuits or heterogeneity of a high dielectric or ferroelectric oxide layer.
Because of these problems, the use of oxide conductors such as IrO2, RuO2, LSCO, YBCO, etc., and platinum-oxide hybrid structures such as IrO2/Pt, RuO2/Pt, LSCO/Pt, YBCO/Pt, etc., as a bottom electrode have been investigated. However, when the former is used as the bottom electrode, the surface is not smooth enough and/or leakage currents increase. Furthermore, in the latter case, the manufacturing processes become complicated.
A solution for these disadvantages of conventional arts was addressed in two Korean patent applications (Serial Nos. 94-31618 filed Nov. 26, 1994 and 95-40450 filed Nov. 8, 1995) in the name of the present applicants. It is well known that oxygen may be contained in the depositing atmosphere when employing an insulating thin film on a substrate. The working effect of the two inventions addressed in said Korean applications filed in the name of the present applicants suggests a new technique. According to these inventions, a platinum thin film is deposited on an insulating oxide layer on a silicon wafer in two steps. The first step is to form a platinum thin film containing oxygen, as opposed to platinum, under an oxygen-containing atmosphere. The second step is to form a platinum layer on the Pt films formed at the first step under an inert gas atmosphere. The gases incorporated in the film during the first step are removed by annealing the film to a temperature higher than the decomposition temperatures of platinum oxides (PtO2: higher than 450xc2x0 C., PtO: higher than 550xc2x0 C.). Through this annealing process, the oxygen contained in the platinum film during the deposition thereof is removed and the remaining platinum film becomes stable. As a result, an adhesion layer is not required and thus problems related to the adhesion layer are solved.
According to the description in said Korean applications, xe2x80x9can oxygen containing gaseous atmospherexe2x80x9d means a mixture of inert gas (Ar, Kr, Xe, or Ne) with either oxygen or ozone gas mixture, or a gas mixture containing oxygen. xe2x80x9cA platinum thin film containing oxygenxe2x80x9d means that oxygen is contained in the platinum layer, partially forming a platinum oxide, and partially forming an amorphous phase in the platinum layer.
In addition to the aforementioned disadvantages in the conventional arts, there still remains another unresolved problem that crystallographic orientations of platinum thin films are uncontrollable. It is well known that the properties of anisotropic crystals depend on their crystallographic orientations. The crystallographic orientations of oxide films formed on bottom electrodes depend on the crystallographic orientations of the bottom electrodes. Therefore, it is believed that controlling the preferred orientation of bottom electrodes is very important in controlling the preferred orientation of oxide films in order to have films with desirable physical properties.
It is expected in the pertinent technical field that, if a platinum thin film employed as a bottom electrode is deposited with a preferred (200) orientation, a ferroelectric oxide thin film, which is formed on the platinum thin film, could be mostly oriented to one direction (for example, c-axis). On the account of this preferred orientation, the working efficiency of the electronic device is expected to significantly increase, and its fatigue effect is expected to decrease.
It is known that a platinum thin film, which is deposited on an insulating oxide layer by the conventional methods, generally has a preferred (111) orientation. This is due to the fact that the plane with the minimum surface energy in metals with face centered cubic (FCC) structure is (111) and, considering only the surface energy at the depositing, the film is most stable if oriented toward (111).
Conventional methods for forming preferred orientation-controlled platinum films that have been suggested have limitations. One of such conventional methods is forming the platinum film on a single crystal substrate of the materials such as MgO, NaCl, KBr, SrTiO3, Al2O3, and LaAlO3. However, such a method not only is complicated in its process and incurs high unit costs for single-crystalline substrates but also is incompatible with the state-of-the art in manufacturing silicon-integrated circuits. Other conventional methods have formed orientation-controlled platinum films by depositing platinum on a glass substrate not on a silicon wafer, or by using a specially designed sputtering equipment which has an xe2x80x9cauxiliary electrodexe2x80x9d in order to deposit platinum film on silicon substrates. However, it has been reported that orientation-controlled platinum films deposited on glassy substrates have high resistivity (18 to 30 xcexcxcexa9-cm) since oxygen, which was introduced during the deposition thereof, has remained within the platinum films even after annealing for 10 days. Therefore, it has been thought to be difficult and impractical to apply this process to real manufacturing practices, due to the annealing condition.
It is seen from the above that the alternative and improved methods for forming preferred orientation-controlled platinum films onto silicon wafers as well as other substrates are needed. It is desirable that such methods be compatible with silicon-integrated circuit technology in some applications. It is also desirable that such preferred orientation-controlled platinum films have minimized pinholes, pores or hillocks in order to provide improved device performance.
The aforementioned drawbacks have been resolved by the invention disclosed in Korean Patent Application No. 96-7663 filed on Mar. 21, 1996 (corresponding U.S. application Ser. No. 08/688,521, filed Jul. 30, 1996) by the present applicants"" technology of depositing a platinum film having a preferred (200) orientation on a silicon wafer under an atmosphere containing oxygen. According to that invention, platinum thin films deposited on a silicon wafer with an insulating oxide layer have good adhesion strength and a preferred (200) orientation.
Therefore, to date, there has been no report of desirable results with depositing a platinum film on a silicon substrate in such a manner that the platinum film has a microstructure that can be controlled; an orientation that can be controlled to (111), (200), or (220); and an excellent conductivity desirable for application to DRAM, FRAM or sensor devices.
It is therefore an objective of the present invention to provide a method of manufacturing a platinum film, the orientation and microstructure of which can be controlled irrespective of the employment of an adhesion layer formed thereon, and such platinum film manufactured thereby.
It is still another objective of the present invention to provide a method of manufacturing an electronic device comprising an orientation-controlled platinum film and an electronic device manufactured thereby.
According to one aspect of the present invention to achieve the above objectives, the present invention provides a method of forming a platinum film on a substrate. The method includes the steps of: providing a substrate; depositing platinum on an upper surface of the substrate under an inert gas atmosphere containing an oxygen component (O2, O3, N2+O2, N2O, or mixtures thereof) to deposit a platinum film containing oxygen; and annealing the platinum film containing the oxygen component at a temperature between 450xc2x0 C. to 1,000xc2x0 C. which is higher than the decomposition temperatures of the platinum oxides to remove the gases incorporated into the platinum films during the deposition. Orientation of such a platinum film can be controlled by changing at least one of the following parameters: the partial pressure ratio of the oxygen component to the entire gas containing the inert gas and oxygen component, the temperature of the substrate during the deposition, and the annealing conditions. The platinum film can be formed through two or more deposition steps, according to specific embodiments.
In accordance with the present invention, the platinum film may be deposited by employing any one of the following methods: direct current or radio frequency (DC/RF) magnetron sputtering, DC/RF sputtering, metal organic chemical vapor deposition, partially ionized beam deposition, vacuum evaporation, laser ablation, and electroplating.
In other embodiments, the method forming a platinum film described above can be applied to a process for manufacturing an electronic device by forming a high-dielectric or ferroelectric oxide film on the platinum film. In this case, for example, the platinum film functions as a bottom electrode. Depending on types of electronic devices to which the film is applied, a functional intermediate film (such as an insulation layer, a conductive plug, an adhesion layer, or a diffusion barrier layer) may be provided between the platinum film and the substrate, according to various specific embodiments. In accordance with other specific embodiments, the present invention provides an electronic device with preferable characteristics required for memory cells or sensor devices.
The present invention along with its features and advantages will now be explained in detail with reference to the attached drawings illustrating preferred embodiments of the present invention.

Apparatus and method of forming preferred orientation-controlled platinum film using oxygen


A surgical trocar access sheath having a laterally expandable retention mechanism for percutaneous insertion through a body cavity wall. The expandable retention mechanism is positioned about the distal end of the sheath for retaining the access sheath within the body cavity. The access sheath has an inner elongated member cannula and an outer elongated member tube having a slick surface for ready insertion through a puncture site. The laterally expandable retention mechanism includes a plurality of strips extending and formed longitudinally in the outer tube. The retention mechanism has an expanded state and a retracted state. In the expanded state, the longitudinal strips extend radially from the outer elongated member tube to engage the interior surface of the body cavity wall. The expandable retention mechanism is actuated by sliding an actuating mechanism hub attached to the distal end of the outer elongated member tube against another hub fixedly attached to the inner elongated member cannula. To insert or retract the access sheath through the cavity wall of a patient, the physician squeezes the actuating mechanism hub against the fixed hub to collapse the longitudinal strips against the surface of the inner elongated member cannula. Once inserted, the actuating mechanism is released to expand the retention mechanism.

A number of trocar access sheaths are presently available for puncturing the abdominal wall and inserting the sheath into an insufflated body cavity such as the peritoneal cavity. After insertion into the insufflated cavity, the trocar is removed from the passageway of the access sheath and an insufflation line connected to a side port extending laterally from a hub attached to the proximal end of the sheath. An endoscope is commonly inserted through the sheath to provide viewing of the insufflated peritoneal cavity. Additional access sheaths are placed through the abdominal wall to provide further access for other endoscopic surgical instruments. During the surgical procedure, the penetration and position of the endoscope is typically adjusted within the cavity to provide different viewing angles. Various endoscopic surgical instruments are inserted through other access sheaths to manipulate the organs and tissue within the cavity. During the surgical procedure, these endoscopic surgical instruments are often inserted and removed many times from the peritoneal cavity through the access sheaths. During insertion and removal, the access sheaths are inadvertently forced further into the cavity or pulled through the puncture site. A problem with inadvertent removal is the subsequent reinsertion of the sheath into the body cavity through the puncture site. In addition, insufflating gas commonly escapes through the puncture site. Should a large amount of the insufflating gas escape, the reinsertion of the access sheath with a trocar presents the risk of perforating an organ such as a bowel which contaminates the surgical field along with requiring suturing of the perforated tissue.
Suprapubic bladder catheters and gastrostomy feeding tubes in a related field typically utilize a balloon retention cuff about the proximal end thereof to prevent the tube from being inadvertently removed through the abdominal wall. However, the incorporation of a balloon cuff about the distal end of a trocar access sheath presents additional material which must be inserted through the puncture site. Furthermore, additional space consuming lumens must be incorporated into the access sheath to provide inflation and maintenance of the balloon cuff in an expanded state. These inflation lumens or lines add further bulk to the diameter of the access sheath which is clearly undesirable.