A filter assembly including a filter housing defining an interior chamber with an open end, a filter disposed within the interior chamber, and a cover removably positioned over the open end to enclose the interior chamber. The filter housing defines an axially-facing sealing surface spaced from the open end. The filter includes a filter element and a flange element, with the flange element having a hook-shaped lip portion defining an axially-facing groove adapted to securely retain an O-ring seal therein. The cover includes an axially-extending sidewall portion and a laterally-extending flange portion, with the sidewall portion defining an outward taper adapted to retain an O-ring seal thereon. A clamp is used to bias the cover into sealing engagement with the open end of the filter housing. The cover in turn biases the flange element of the filter into sealing engagement with the axially-facing sealing surface of the filter housing.

Various types and configurations of filter assemblies are used in the field of liquid filtration to remove solid materials or contaminants from a liquid flow. Filter assemblies typically include a removable/replaceable filter element, such as a bag or basket, disposed within a filter housing. The filter housing includes inlet and outlet ports that direct liquid flow into and out of the filter housing and through the filter element. Since the filter element must be periodically inspected, cleaned and/or replaced, the filter housing is usually equipped with a removable lid or cover. A significant concern regarding the design of these types of filter assemblies is the ease and timeliness in which the filter element can be accessed for maintenance. In most cases, access to the filter element requires by-passing or shutting off fluid flow to the filter assembly. It is therefore advantageous to minimize the time required to access, clean and/or replace the filter element to minimize system down time and to reduce maintenance costs.
Filter assemblies of the above-discussed type usually require a seal or gasket disposed between the filter element and the filter housing to provide a liquid-tight seal between the unfiltered liquid and the filtered liquid. A seal or gasket is also usually required to provide a liquid-tight seal between the main body of the filter housing and the filter housing lid. As discussed above, periodic maintenance of the filter assembly requires removal of the filter housing lid and typically requires complete removal of the filter element from the filter housing. During removal of the filter housing lid and the filter element, the seals or gaskets may become inadvertently or unintentionally dislodged from the filter assembly. As a result, the seals or gaskets may be lost or damaged. The seals or gaskets may also fall into the filter housing and/or the fluid outlet port, thereby requiring a time-consuming and potentially costly retrieval process to avoid contamination of the outlet fluid flow. Additionally, if the seals or gaskets become dislodged from the filter assembly, they must be reinstalled prior to start-up, thereby tending to increase maintenance time and associated labor costs.
Thus, there is a general need in the industry to a filter assembly having improved sealing features. The present invention satisfies this need and provides other benefits and advantages in a novel and unobvious manner.

Filter assembly having improved sealing features


A circuit (10) having multiple poles within an active frequency range employs a movable zero (66) to maintain stability in the circuit (10) under variable load conditions. A pole (62) created by a frequency compensation element (14) maintains a fixed frequency within the active frequency range of the circuit (10). In addition, a variable load impedance (36) coupled to the circuit (10) generates a load pole (64) within the active frequency range of the circuit (10) that changes frequency over time. As the load pole (64) changes frequency, the frequency of the movable zero (66) is adjusted to achieve an enhanced stability condition within the circuit (10). In one embodiment, the frequency of the movable zero (66) tracks the frequency of the load pole (64) as the load impedance (36) changes.

The invention relates generally to techniques for maintaining stability within an electrical circuit and, more particularly, to techniques for maintaining stability in a circuit under variable load conditions.
Some electrical circuitry is required to operate under a wide variety of different load conditions. For example, a voltage regulator circuit is typically required to maintain a regulated output voltage even when there is a widely varying load impedance coupled to the regulator. As can be appreciated, such circuitry must remain stable for all possible load conditions. The load impedance that is coupled to the circuitry can introduce a pole into the transfer function of the circuitry that is located within the active frequency range of the circuitry. In addition, the circuitry itself can also generate one or more poles that are within the active frequency range of the circuitry. For example, a frequency compensation capacitor within a circuit will often generate a dominant pole within the active frequency range of the circuit.
As is well known, the presence of two or more poles within the active frequency range of a circuit can lead to instability within the circuit unless additional measures are taken to prevent such instability. Typically, a zero is added to the transfer function of the circuitry to counteract the effect of having two poles within the active frequency range. The zero that is added to the transfer function will have a frequency that lies near that of one or both of the poles in a position that will prevent instability. In a circuit having a variable load impedance, however, the frequency of the load pole can vary greatly during normal circuit operation. Thus, while the fixed location of the zero may be optimal for some possible load conditions, it will generally be sub-optimal under other possible load conditions. Typically, the frequency of the zero will be chosen to provide optimal compensation for an intermediate load condition, thus compromising circuit stability under high and low load conditions.
Therefore, there is a need for a method and apparatus for maintaining the stability of a circuit under variable load conditions.

Method and apparatus for maintaining stability in a circuit under variable load conditions


An apparatus for determining a road-wheel vibration for an automotive vehicle comprises wheel-speed sensors for detecting wheel speeds of each of road wheels, and a control unit which is configured to be electrically connected to the wheel-speed sensors for processing a wheel-speed data signal detected from each of the wheel-speed sensors. The control unit comprises a wheel acceleration calculating section for calculating a wheel acceleration and a wheel deceleration of each of the road wheels based on the wheel-speed data signal, a wheel acceleration cycle calculating section for calculating a wheel acceleration cycle of each of the road wheels, a vehicle deceleration calculating section for calculating a vehicle deceleration, a vibration detecting section for detecting a road-wheel vibration of the road wheel based on at least the wheel acceleration cycle, and a vibration determining section for determining whether the road-wheel vibration is caused by a bad road surface condition, or the road-wheel vibration is caused by a drive-train vibration of the automotive vehicle, based on the vehicle deceleration.

1. Field of the Invention
This invention relates to an improvement of determining a road-wheel vibration of an automotive vehicle that is caused by a road surface condition, and especially, to an anti-skid braking system that executes a skid control procedure depending on the road-wheel vibration determined by a road-wheel vibration determining system.
2. Description of the Related Art
As is generally known, there have been proposed various anti-skid braking systems for automotive vehicles (hereinafter, referred to as xe2x80x9cABSxe2x80x9d) that prevent a skid of the road wheel during a braking in order to provide a maximum effective braking. The ABS executes a skid control by regulating a pressure of each wheel-brake cylinder mounted to each of the road wheels, depending on a pressure-reduction threshold that is calculated based on a wheel speed of each of the road wheels in a vehicle traveling condition. For instance, when the wheel speed becomes lower than a pressure-reduction threshold value, that is, the road wheel tends to be locked, the ABS executes a pressure-reduction procedure of the wheel-brake cylinder pressure. In contrast, when the wheel speed becomes higher than the pressure-reduction threshold value, the ABS executes a pressure build-up procedure so as to adjust the wheel speed toward the pressure-reduction threshold value. By repeating the pressure-reduction procedure and the pressure build-up procedure, a minimum braking distance can be provided. When skid control is executed in a bad road surface condition, the bad road surface condition causes a road-wheel vibration. Thus, if the ABS executes the skid control depending on the same pressure-reduction threshold value that is calculated in a normal road surface condition, the wheel speed fluctuates around the pressure-reduction threshold at a high-frequency that causes a frequent execution of the pressure-reduction procedure. Thereby, a braking distance tends to be long.
As a measure of the foregoing problem, there have been proposed another type of anti-skid braking system that sets the pressure-reduction threshold at a lower value as compared to a normal value set in the normal road surface condition when the bad road surface condition is determined. According to a conventional manner, the bad road surface condition is determined when the wheel speed cycle becomes lower than a predetermined value.
However, during the skid control, the road-wheel vibration is sometimes caused by a drive-train vibration. In this case, when the bad road surface condition is determined by the conventional manner, the drive-train vibration might be determined to be a road-wheel vibration that is caused by the bad road surface condition. Particularly, in a low coefficient of friction of the road surface condition (hereinafter, a coefficient of friction of the road surface is referred to as xe2x80x9cxcexcxe2x80x9d), if the pressure-reduction threshold is set at the lower value due to such determination, the pressure-reduction procedure tends to be executed late as a result of setting the pressure-reduction threshold at the lower value. Thereby, a skid of the road wheel might occur. Furthermore, since a range of a pressure-reduction volume and a pressure build-up volume tend to be large because of such late execution of the pressure-reduction procedure, a hunting of an execution of the skid control may occur.
A torque of an engine is transmitted from an engine to driving wheels via a drive shaft and a differential gear. When the ABS executes the pressure build-up procedure and the pressure-reduction procedure while the torque is accelerating the automotive vehicle, a phase shift of the torque is sometimes made due to a generation of an interference of the torque among the engine, the drive shaft, the differential gear and the driving wheel that causes a resonance of 6-7 Hz. Furthermore, in case of a four-wheel drive vehicle, which has a strong constraint force between a front axle and a rear axle, if an inverse phase of the torque is generated by an inverse timing of executing the pressure build-up procedure between the front axle and the rear axle, a torsional resonance is generated on the drive shaft.
In order to solve aforementioned problem, there has been proposed the another type of ABS having a vibration determining system that determines whether the road-wheel vibration is caused by the bad road surface condition, or the road-wheel vibration is caused by the drive-train vibration. One such vibration determining system is disclosed in a Japanese patent publication (koukai) No. 7-257347. According to the publication, the road-wheel vibration is detected based on a wheel acceleration cycle and a wheel acceleration amplitude, and then, the road-wheel vibration is determined whether the road-wheel vibration is caused by the bad road surface condition, or the road-wheel vibration is caused by the drive-train vibration based on a wheel acceleration. When the ABS determines that the road-wheel vibration is caused by the bad road surface condition, the ABS sets the pressure-reduction threshold at the lower value as compared to the normal value set in the normal road surface condition. Thereby, a tendency of the road wheel to be locked caused by the late execution of the pressure-reduction proceeding is avoided. When a drive-train vibration is identified, the pressure-reduction threshold is not changed.
However, since a change of the wheel speed varies in a bad road surface condition, the same wheel acceleration generated in a case where the drive-train vibration is causing the road-wheel vibration is sometimes made in the bad road surface condition. In this case, according to the conventional manner, since the road-wheel vibration is determined based on the wheel acceleration, the ABS determines that the road-wheel vibration is caused by the drive-train vibration, and thus, the pressure-reduction threshold is not changed. Thereby, an insufficient braking force may be made.
In case of the four-wheel drive vehicle, during a traveling in a four-wheel drive state, the ABS might determine that the road-wheel vibration is caused by the bad road surface condition, when the torsional resonance is generated on the drive shaft by a braking. As a result of such determination, the ABS sets the pressure-reduction threshold at the lower value, and the road wheel tends to be locked that causes an instability of the vehicle. Thereby, a late pressure-reduction procedure, which causes a tendency of the range of the pressure-reduction volume and the pressure build-up volume to be wide, is executed, and therefore, the hunting of the execution of the skid control that would encourage the drive-train vibration may occur. According to the related art disclosed in the publication, although the ABS sets the pressure-reduction threshold at the lower value when the bad road surface condition is determined, the minimum braking distance cannot be provided by simply setting the pressure-reduction threshold at the lower value. Moreover, although the ABS disclosed in the related art sets the pressure-reduction threshold at a higher value as compared to the normal value when the drive-train vibration is determined, the drive-train vibration cannot be inhibited due to a repeated execution of the pressure-reduction procedure and the pressure build-up procedure.
Accordingly, in view of above described problems, a principal object of the present invention is to provide an improved method of determining a road-wheel vibration and a method of executing an anti-skid control having a road-wheel vibration determining method, and an anti-skid control system using the same method, by which the road-wheel vibration is accurately determined, whether a bad road surface condition causes the road-wheel vibration or a drive-train vibration causes the road-wheel vibration.
Another object of the present invention is to provide an anti-skid braking system that provides a maximum effective braking with a minimum braking distance in a bad road surface condition.
Still another object of the present invention is to inhibit the drive-train vibration.
In order to achieve these and the other objects, a first aspect of the present invention provides a method of determining a road-wheel vibration that comprises the operations of detecting a wheel speed of each of road wheels, calculating a wheel acceleration and a wheel deceleration of each of the road wheels, calculating a wheel acceleration cycle of each of the road wheels, calculating a vehicle deceleration, detecting the road-wheel vibration based on the calculated wheel acceleration cycle, and determining whether the road-wheel vibration is caused by a bad road surface condition, or the road-wheel vibration is caused by a drive-train vibration, based on the calculated vehicle deceleration.
According to another aspect of the invention, a method of executing a skid control comprises the operations of detecting a wheel speed of each of road wheels, calculating a wheel acceleration and a wheel deceleration of each of the road wheels, calculating a wheel acceleration cycle of each of the road wheels, calculating a vehicle deceleration. Comparing the calculated wheel acceleration to a first predetermined value, and comparing the calculated wheel acceleration cycle to a second predetermined value, and in response to such comparisons, detecting a road-wheel vibration when the calculated wheel acceleration is larger than the first predetermined value, and when the calculated wheel acceleration cycle is smaller than the second predetermined value. Comparing the calculated vehicle deceleration to a third predetermined value, and in response to such comparison, determining that the road-wheel vibration is caused by a bad road surface condition when the calculated vehicle deceleration is larger than the third predetermined value, and that the road-wheel vibration is caused by a drive-train vibration when the calculated vehicle deceleration is smaller than the third predetermined value. Setting a pressure-reduction threshold depending on the operations of the detecting the road-wheel vibration and determining the road-wheel vibration. The operation of setting the pressure-reduction threshold sets the pressure-reduction threshold value at a lower value as compared to a normal road surface condition when the bad road surface condition is determined, and the operation of setting the pressure-reduction threshold sets the pressure-reduction threshold value at a higher value as compared to the normal road surface condition when the drive-train vibration is determined. And executing a skid control by regulating each wheel-brake cylinder pressure, the operation of executing the skid control executes a pressure build-up procedure, a pressure-reduction procedure, and a pressure-hold procedure depending on the pressure-reduction threshold set by said operation.
According to still another aspect of the invention, there is provided a road-wheel vibration determining system for an automotive vehicle that comprises wheel-speed sensors for detecting wheel speeds of each of road wheels, and a control unit that is configured to be electrically connected to the wheel-speed sensors for processing a wheel-speed data signal detected from each of the wheel-speed sensors. The control unit comprises a wheel acceleration calculating section for calculating a wheel acceleration and a wheel deceleration of each of the road wheels based on the wheel-speed data signal, a wheel acceleration cycle calculating section for calculating a wheel acceleration cycle of each of the road wheels, a vehicle deceleration calculating section for calculating a vehicle deceleration, a vibration detecting section for detecting a road-wheel vibration of the road wheel based on at least the wheel acceleration cycle, and a vibration determining section for determining whether the road-wheel vibration is caused by a bad road surface condition, or the road-wheel vibration is caused by a drive-train vibration of the automotive vehicle, based on the vehicle deceleration.
According to further aspect of the invention, an anti-skid braking system comprises wheel-speed sensors for detecting the wheel speed of each of road wheels, and a hydraulic brake unit for regulating wheel-brake cylinder pressure of wheel-brake cylinders mounted to each of the road wheels. The hydraulic brake unit is capable of forming a pressure build-up mode, a pressure-reduction mode, and a pressure-hold mode of each of the wheel-brake cylinders. There also is a control unit that is configured to be electrically connected to the wheel-speed sensors for processing a wheel-speed data signal detected from each of the wheel-speed sensors. The control unit comprises a wheel acceleration calculating section for calculating a wheel acceleration and a wheel deceleration of each of the road wheels based on the wheel-speed data signal, a wheel acceleration cycle calculating section for calculating a wheel acceleration cycle of each of the road wheels, a vehicle deceleration calculating section for calculating a vehicle deceleration, and a vibration detecting section for detecting a road-wheel vibration of the road wheel based on the wheel acceleration and the wheel acceleration cycle. The vibration detecting section detects the road-wheel vibration when the wheel acceleration is larger than a first predetermined value, and when the wheel acceleration cycle is smaller than a second predetermined value. There also is a vibration determining section for determining whether the road-wheel vibration is caused by a bad road surface condition, or the road-wheel vibration is caused by a drive-train vibration of the automotive vehicle. The vibration determining section determines that the road-wheel vibration is caused by the bad road surface condition when the vehicle deceleration is larger than a third predetermined value, and that the road-wheel vibration is caused by the drive-train vibration when the vehicle deceleration is smaller than the third predetermined value. There is a pressure-reduction threshold setting section for setting a pressure-reduction threshold depending on the road-wheel vibration detected and determined by the vibration detecting section and the vibration determining section. The pressure-reduction threshold setting section sets a pressure-reduction threshold value at a lower value, as compared to a normal road surface condition, when the bad road surface condition is determined by the vibration determining section, and the pressure-reduction threshold setting section sets the pressure-reduction threshold value at a higher value, as compared to the normal road surface condition, when the drive-train vibration is determined by the vibration determining section. Finally, there is a skid control section for preventing a skid of each of the road wheels by regulating each wheel-brake cylinder pressure. The skid control section executes a pressure build-up procedure, a pressure-reduction procedure, and a pressure-hold procedure depending on the pressure-reduction threshold set by the pressure-reduction threshold setting section.
According to still further aspect of the invention, an anti-skid braking system comprises wheel-speed sensors for detecting the wheel speed of each of the road wheels, and a hydraulic brake unit for regulating wheel-brake cylinder pressure of wheel-brake cylinders mounted to each of the road wheels. The hydraulic brake unit is capable of forming a pressure build-up mode, a pressure-reduction mode, and a pressure-hold mode of each of the wheel-brake cylinders. There also is a control unit that is configured to be electrically connected to the wheel-speed sensors for processing a wheel-speed data signal detected from each of the wheel-speed sensors. The control unit comprises a wheel acceleration calculating section for calculating a wheel acceleration and a wheel deceleration of each of the road wheels based on the wheel-speed data signal, a wheel acceleration cycle calculating section for calculating a wheel acceleration cycle of each of the road wheels, a vehicle deceleration calculating section for calculating a vehicle deceleration, and a vibration detecting section for detecting a road-wheel vibration of the road wheel based on the wheel acceleration and the wheel acceleration cycle. The vibration detecting section detects the road-wheel vibration when the wheel acceleration is larger than a first predetermined value, and when the wheel acceleration cycle is smaller than a second predetermined value. There is a vibration determining section for determining whether the road-wheel vibration is caused by a bad road surface condition, or the road-wheel vibration is caused by a drive-train vibration of the automotive vehicle. The vibration determining section determines that the road-wheel vibration is caused by the bad road surface condition when the vehicle deceleration is larger than a third predetermined value, and that the road-wheel vibration is caused by the drive-train vibration when the vehicle deceleration is smaller than the third predetermined value. There also is a pressure-reduction threshold setting section for setting a pressure-reduction threshold depending on the road-wheel vibration detected and determined by the vibration detecting section and the vibration determining section. The pressure-reduction threshold setting section sets a pressure-reduction threshold value at a lower value, as compared to a normal road surface condition, when the bad road surface condition is determined by the vibration determining section, and the pressure-reduction threshold setting section sets the pressure-reduction threshold value at a higher value, as compared to the normal road surface condition, when the drive-train vibration is determined by said vibration determining section. There is a skid control section for preventing a skid of each of the road wheels by regulating each wheel-brake cylinder pressure. The skid control section executes a pressure build-up procedure, a pressure-reduction procedure, and a pressure-hold procedure depending on the pressure-reduction threshold set by the pressure-reduction threshold setting section, and the skid control section prohibits the pressure build-up procedure within a predetermined period, at least right after an initial pressure-reduction procedure is executed, when the drive-train vibration is determined by the vibration determining section. The skid control section comprises a pressure build-up procedure control section for controlling the pressure build-up procedure. The pressure build-up procedure control section executes a gradual pressure build-up procedure after an initial pressure build-up procedure is executed, when said skid control section determines a further pressure build-up procedure is needed. There is a pressure-rising volume changing section for changing a pressure-rising volume depending on the road-wheel vibration detected and determined by the vibration detecting section and the vibration determining section. The pressure-rising volume changing section changes the pressure-rising volume at a higher value as compared to the normal road surface condition when the bad road surface condition is determined by the vibration determining section, and changes the pressure-rising volume at a lower value as compared to the normal road surface condition when the drive-train vibration is determined by said vibration determining section. The pressure-rising volume changing section changes the pressure-rising volume at least when the pressure build-up procedure control section executes the initial pressure build-up procedure. The pressure-rising volume changing section changes a pressure-rising period at a shorter value as compared to a normal pressure-rising period executed in the normal road surface condition when the pressure-rising volume changing section changes the pressure-rising volume at the higher value, and changes the pressure-rising period at a longer value as compared to the normal pressure-rising period when the pressure-rising volume changing section changes the pressure-rising volume at the lower value. Finally, there is a pressure-reduction volume changing section for changing a pressure-reduction volume depending on the road-wheel vibration detected and determined by the vibration detecting section and the vibration determining section. The pressure-reduction volume changing section changes the pressure-reduction volume at a lower value as compared to the normal road surface condition when the bad road surface condition is determined by the vibration determining section.

Apparatus and method for determining a road-wheel vibration of automotive vehicle, and apparatus and method for anti-skid control using the same


The present invention relates to compounds trans (E) and cis (Z) stereoisomers of 4-t-butyl gabapentin of formula (11) and (12) and a process for the preparation of the said stereoisomers.

1. Technical Field
The present invention relates to stereo isomers (E) and (Z) of 4-t-butyl gabapentin and a process for the preparation of the said stereoisomers.
2. Background and Prior Art Reference
Gabapentin, (1-aminomethyl)cyclohexane-1-acetic acid is an antiepileptic drug, which has been found to have pain-relieving properties. Additionally, it is claimed to have anti-anxiety activity as also beneficial properties in treating neurodegenerative diseases like Alzheimer's. Gabapentin and its analogues are reported to exert their activity by binding to the alpha 2-delta sub unit of calcium channel.
WO 99114184 reports the synthesis of gabapentin analogues 3-methyl, 4-methyl and 3,5-dimethyl gabapentin and their biological activity. In all these analogues the aminomethyl group could preferentially occupy the equatorial position in the more stable conformation along with certain percentage in the axial position. However the exact conformation in which these bind to a receptor is not known. If the energy differences are not significant, binding with the aminomethyl group in the axial position cannot be ruled out. This document does not claim the report of t-butyl gabapentin specifically but covers it in a generic way.
The tertiary butyl group has been known as an anchoring substituent on the cyclohexane ring occupying exclusively the equatorial confirmation in the ring. Therefore, if one were to synthesize 1-aminomethyl cyclohexane-1-acetic acids with a 4-t-butyl group in cis or trans stereochemistry with respect to the aminomethyl group to obtain Z and E stereoisomer respectively it should be feasible to study better, the optimal conformation for good binding of 4-t-butyl gabapentin with the alpha 2 delta sub unit of the calcium channel.
However, prior art search revealed the report of 4-t-butyl gabapentin in documents U.S. Pat. No. 6,103,932 and WO 02100347 A2. U.S. Pat. No. 6,103,932 recites and claims 4-t-butyl gabapentin, and a pharmaceutically acceptable salts thereof or a prodrug thereof, while WO 2002100347A notes the use of t-butylgabapentin in the form of a prodrug without any example. The document also describes general synthetic methods for the preparation of alkyl gabapentin analogues having one or more alkyl substituents in the cyclohexane ring. There is no specific example describing the preparation of the compound 4-t-butylgabapentin. This patent also records the radio ligand-binding assay with the alpha 2 detla sub unit derived from porcine brain tissue giving an IC50 value of 200 micro M for 4-t-butyl gabapentin, again without stereochemistry, thus missing out a solution to the crucial and challenging issue of conformational identity in the native and bound states.
U.S. Pat. No. 6,103,932 describe various synthetic routes for the preparation gabapentin analogues where as WO 99114184 restricts itself to the use of a nitro methyl intermediate to obtain gabapentin analogues. In the former patent, two routes are employed: (a) an alkyl-substituted cyclohexanone is converted to a cyanocyclohexylidene acetic ester, which is treated with aqueous alcoholic sodium cyanide to 1-cyanocyclohexane acetic ester, which upon reduction gives an azaspirodecanone. Hydrolysis of the lactam with 1:1 HCl affords the alkyl substituted gabapentin hydrochloride. In the second route, an alkyl substituted cyclohexanone is treated with ethyl cyanoacetate and ammonia gas in methanol to afford a dicyano spiroglutarimide which is hydrolysed by hot concentrated sulphuric acid to an alkyl substituted cyclohexane-1,1-diacetic acid. The diacid is converted to the anhydride, which is opened up with methanol to give the half-ester acid. This is treated with ethyl chloroformate followed by sodium azide. Thermolysis of the acylazide gives an isocyanate which upon hydrolysis with concentrated hydrochloric acid yields the alkyl substituted gabapentin hydrochloride.
In WO 99114184, the method adopted is to add nitromethane to an alkyl substituted cyclohexylidene acetic ester, which upon catalytic reduction affords the alkyl-substituted azaspirodecanone. Hydrolysis with 6 N HCl and evaporation affords the alkyl substituted gabapentin hydrochloride.
U.S. Pat. No. 6,103,932 and PCT Int'l Application publication WO 99/14184 describe examples wherein the final products, gabapentin analogues are obtained only as hydrochloride salts. Thus, in order to establish the optimal conformation for the compound 4-t-butyl gabapentin, which can bind with the alpha2delta submit of the calcium channel, it is necessary to obtain cis and trans form of 4-t-butylgabapentin with high purity.
There are prior art references on gabapentin analogues with one or more methyl groups in the cyclohexane ring and publications on their binding activity. The ascertainment of the precise conformation in which the amino group in gabapentin binds to the alpha2delta subunit can have great significance in the design of newer analogues of gabapentin and more specifically alkyl gabapentin analogues. None of the prior art document reports cis and trans stereoisomers of 4-t-butylgabapentin and their process of preparation.

Gabapentin analogues and process thereof


According to the present invention, there are provided a method for heat treatment of silicon wafers wherein a silicon wafer is subjected to a heat treatment at a temperature of from 1000xc2x0 C. to the melting point of silicon in an inert gas atmosphere, and temperature decreasing in the heat treatment is performed in an atmosphere containing 1-60% by volume of hydrogen, a method for heat treatment of silicon wafers under a reducing atmosphere containing hydrogen by using a rapid heating and rapid cooling apparatus, wherein temperature decreasing rate from the maximum temperature in the heat treatment to 700xc2x0 C. is controlled to be 20xc2x0 C./sec or less, and a silicon wafer which has a crystal defect density of 1.0xc3x97104 defects/cm3 or more in a wafer bulk portion, a crystal defect density of 1.0xc3x97104 defects/cm3 or less in a wafer surface layer of a depth of 0.5 xcexcm from the surface, a crystal defect density of 0.15 defects/cm2 or less on a wafer surface and surface roughness of 1.0 nm or less in terms of the P-V value. By these, crystal defects in wafer surface layers can be reduced by a simple method with a small amount of hydrogen used without degrading microroughness of wafers.

The present invention relates to a method for heat treatment of silicon wafers, in particular, a method for heat treatment of silicon wafers that shows superior safety and can give silicon wafers of high quality.
As wafers for manufacturing semiconductor devices such as semiconductor integrated circuits, silicon wafers are mainly used. In such production of semiconductor devices, crystal defects which exist in wafer surface layers such as COPs (Crystal Originated Particles) can be mentioned as one of factors that degrade the yield. If such crystal defects exist in wafer surface layers, they may be a cause of degradation of electric characteristics of wafers. For example, in transistors of MOS structure, when high voltage is applied to a thermal oxide film formed on a wafer surface such as a gate oxide film, they may cause generation of dielectric breakdown of the oxide film.
As a further factor that worsens the yield of semiconductor device production, microroughness on wafer surfaces can be mentioned. It is known that microroughness that exists on wafer surfaces adversely affect carrier mobility directly under the gate oxide films (see Shinya Yamakawa, Hirai Ueno, Kenji Taniguchi, Chihiro Hamaguchi, Kazuo Miyatsuji, Umbert Ravaioli, J. Appl. Phys., 79, 911, 1995). In semiconductor devices, if degree of integration is increased, carrier mobility must correspondingly be increased. Moreover, with recent use of increasingly higher driving frequency of CPU, write time and read time of memories are required to be made higher. Therefore, it has come to be considered more important to make microroughness small in order to improve carrier mobility.
As a method for reducing crystal defects of silicon wafer surface layers, elimination of the defects by annealing heat treatment and so forth have been performed. A typical example thereof is high temperature hydrogen annealing. This method is a method for eliminating crystal defects by performing annealing heat treatment in a hydrogen atmosphere at a high temperature (see Japanese Patent Laid-open Publication (Kokai) No. 6-349839).
However, although a heat treatment in a hydrogen atmosphere can reduce crystal defects in wafer surface layers, it has a drawback that surfaces of wafers will be etched by the heat treatment. For example, when a heat treatment is performed at 1200xc2x0 C. for 60 minutes, about 0.5 xcexcm of silicon of wafer surface layers will be etched. For this reason, thickness of the portions of wafer surfaces with few crystal defects (defect-free layer) becomes small.
Furthermore, it is very dangerous to handle hydrogen gas at a high concentration at such a high temperature over a long period of time. Thus, it cannot be practically used without solving the problem of safety.
Therefore, there has also been proposed a method for eliminating crystal defects of wafer surface layers by performing a heat treatment using an inert gas such as argon for the atmosphere. However, although the crystal defects in wafer surface layers can be reduced by this method without etching wafer surface layers, it has a drawback that it worsens microroughness on wafer surfaces compared with that before the heat treatment.
In addition, there is also an abuse that local etching comes to be likely to occur due to the influence of a small amount of oxygen in the atmosphere, and thus haze is generated.
The term xe2x80x9chazexe2x80x9d used herein is an index of surface roughness, and means periodical waviness having a period of several to several tens of nanometers on the wafer surfaces. It is surface roughness that can be semi-quantitatively evaluated as a haze level of a whole wafer surface by scanning the whole wafer surface with a particle counter mainly utilizing a laser, and measuring strength of scattered reflection thereof.
Another method for avoiding the danger of hydrogen gas, there has also been contemplated a method utilizing a heat treatment with a hydrogen atmosphere and a heat treatment with an inert gas atmosphere such as argon in combination. This method comprises first performing a heat treatment of wafers in an inert gas atmosphere, and then performing a heat treatment of the wafers in a hydrogen atmosphere (see Japanese Patent Laid-open Publication No. 4-167433).
However, the heat treatment in an atmosphere containing hydrogen at the same temperature as the preceding heat treatment in an inert gas atmosphere will eventually etch wafer surfaces, and thus the defect-free layer thickness will become small.
Further, Japanese Patent Laid-open Publication No. 7-235507 discloses a method which comprises performing a heat treatment in an inert atmosphere, wherein hydrogen is introduced into the atmosphere during the temperature increasing or temperature decreasing period of the heat treatment. However, this method was accomplished with the purpose of preventing generation of slip dislocations in wafers by introducing hydrogen having heat conductivity higher than that of inert gas during the temperature increasing or temperature decreasing, and this method is not for eliminating crystal defects which exist in wafer surface layers or improving microroughness on wafer surfaces.
That is, this method simply comprises continuously introducing 1 liter/minute of hydrogen during the temperature increasing and decreasing, and an optimum composition of the heat treatment atmosphere during the temperature increasing and decreasing is unknown. Therefore, even if this method is used, the etching amount of the wafer surfaces may become large, or microroughness may be worsened. Thus, crystal defect density and surface roughness cannot be improved simultaneously.
As described above, among the conventional heat treatment methods, there are no method for reducing crystal defects of wafer surface layers without etching wafer surface layers and without degrading microroughness of wafers, with a little amount of hydrogen used. Therefore, it is desired to develop an effective method.
Furthermore, in the hydrogen annealing, the heat treatment is usually performed under a hydrogen gas atmosphere by increasing temperature at a temperature increasing rate of 1-10xc2x0 C./min, maintaining a temperature of from 950xc2x0 C. to the melting point of silicon for several hours, and then decreasing the temperature at a temperature decreasing rate of 2-5xc2x0 C./min (for example, Japanese Patent Publication (Kokoku) No. 5-18254 and Japanese Patent Laid-open Publication No. 6-295912). However, this heat treatment method has a drawback that the heat treatment requires a long period of time.
Therefore, it has been proposed a method for heat treatment using an apparatus for rapid heating and rapid cooling (Rapid Thermal Annealer, also abbreviated as xe2x80x9cRTA apparatusxe2x80x9d hereinafter) in order to shorten the heat treatment time etc. For example, in Japanese Patent Application No. 10-82606, the inventors of the present invention previously proposed a method for heat treatment of silicon wafers under a reducing atmosphere using an RTA apparatus, and proposed a method for heat treatment that can, in particular, reduce the COP density on surfaces of silicon wafers.
This method comprises a heat treatment of silicon wafers within a temperature range of from 1200xc2x0 C. to the melting point of silicon for 1-60 seconds under a reducing atmosphere. In this method, it is further preferred that 100% hydrogen or a mixed atmosphere of hydrogen and argon is used as the reducing atmosphere, and the heat treatment time is selected to be 1-30 seconds.
Further, it was found that COP density on surfaces of silicon wafers was markedly reduced and one of the electric characteristics, oxide dielectric breakdown voltage (Time Zero Dielectric Breakdown: TDDB), was also markedly improved by this method.
However, this method has a drawback that the aforementioned surface roughness on wafer surfaces after the heat treatment, called haze, may be degraded.
In addition, as mentioned above, it is known that surface roughness on wafer surfaces such as haze closely relates to performance and reliability of devices as a factor which greatly affects the electrical characteristics such as oxide dielectric breakdown voltage and carrier mobility (see Shinya Yamakawa et. al., J. Appl. Phys. 79, 911, 1996), and haze on wafer surfaces is considered a big problem.
Therefore, in Japanese Patent Application No. 10-176693, the inventors of the present invention proposed a method wherein the RTA heat treatment is performed with two or more divided steps as a method for solving that problem. In this method, a heat treatment of a preceding step is performed with the purpose of reduction of COPs, and a heat treatment of a subsequent step is performed in order to improve surface roughness on wafer surfaces such as haze.
Since this method can sufficiently improve haze while reducing COPs, it is a very useful method. However, because it requires performing two or more steps of high temperature heat treatments in an RTA apparatus, it has a drawback of complicated process steps. Such complicated process steps lead to increase of cost due to decrease of throughput. Therefore, it is desired to be further improved.
The present invention was accomplished in view of such problems as mentioned above, and an object of the present invention is to provide a method for heat treatment that can reduce crystal defects in wafer surface layers without etching wafer surface layers and without degrading microroughness on wafer surfaces with a small amount of hydrogen used.
Another object of the present invention is to provide a method for heat treatment of silicon wafers using a rapid heating and rapid cooling apparatus, which can reduce COPs and haze of wafer surfaces in a simpler manner.
In order to achieve the aforementioned objects, the present invention provides a method for heat treatment of silicon wafers, wherein a silicon wafer is subjected to a heat treatment at a temperature of from 1000xc2x0 C. to the melting point of silicon in an inert gas atmosphere, and temperature decreasing in the heat treatment is performed in an atmosphere containing 1-60% by volume of hydrogen.
Thus, by subjecting a silicon wafer to a heat treatment at temperature of from 1000xc2x0 C. to the melting point of silicon in an inert gas atmosphere, crystal defects of the wafer surface layer can be eliminated first. Then, by decreasing the temperature in an atmosphere containing 1-60% by volume of hydrogen during temperature decrease of the heat treatment, microroughness can be improved thanks to migration of silicon atoms on the wafer surface. In this method, since the amount of hydrogen gas used may be small, the safety of the heat treatment step can also be improved.
In the above method, the aforementioned inert gas atmosphere preferably consists of an argon atmosphere or an argon atmosphere containing 30% by volume or less of hydrogen.
This is because argon is easily handled, and even when it contains hydrogen, etching due to hydrogen contained in the atmosphere hardly occurs if its concentration is 30% by volume or less, and the effect of improving microroughness on the wafer surfaces will become higher to the contrary.
The present invention also provides a method for heat treatment of silicon wafers under a reducing atmosphere containing hydrogen by using a rapid heating and rapid cooling apparatus, wherein temperature decreasing rate from the maximum temperature in the heat treatment to 700xc2x0 C. is controlled to be 20xc2x0 C./sec or less.
By employing such a simple method as described above, i.e., only by using a temperature decreasing rate of 20xc2x0 C./sec or less from the maximum temperature in the heat treatment to 700xc2x0 C., in a method for heat treatment of silicon wafers using a rapid heating and rapid cooling apparatus, haze can be improved while COPs of the wafer surface are simultaneously reduced.
In the above method, it is preferred that the temperature decreasing rate in a region below 700xc2x0 C. in the heat treatment should be faster than the temperature decreasing rate from the maximum temperature to 700xc2x0 C.
By using a temperature decreasing rate in a region below 700xc2x0 C. in the heat treatment faster than the temperature decreasing rate in a region of from the maximum temperature to 700xc2x0 C. as described above, the whole heat treatment time can be shortened, and thus the efficiency of the heat treatment can further be improved.
In the above method, it is preferred that the aforementioned reducing atmosphere containing hydrogen should be 100% hydrogen or a mixed gas atmosphere of hydrogen with argon and/or nitrogen.
Such a heat treatment atmosphere can surely reduce COP density on the wafer surface and improve haze.
Moreover, in a silicon wafer subjected to the heat treatment by the aforementioned method of the present invention, COP density on the wafer surface is decreased and haze is made small by the simple method, and thus the electric characteristics of the silicon wafer such as oxide dielectric breakdown voltage and carrier mobility can be improved. Therefore, extremely useful silicon wafers of extremely high quality can be obtained with high productivity.
Specifically, for example, the silicon wafer can be a silicon wafer having a crystal defect density of 1.0xc3x97104 defects/cm3 or more in the wafer bulk portion, a crystal defect density of 1.0xc3x97104 defects/cm3 or less in the wafer surface layer of a depth of 0.5 xcexcm from the surface, a crystal defect density of 0.15 defects/cm2 or less on the wafer surface and surface roughness of 1.0 nm or less in terms of the P-V value.
The term xe2x80x9cwafer bulk portionxe2x80x9d used herein means a portion of wafer present at a depth exceeding 0.5 xcexcm from the wafer surface.
Thus, the silicon wafer of present invention can be a silicon wafer with a low crystal defect density of 1.0xc3x97104 defects/cm3 or less in the wafer surface layer of a depth of 0.5 xcexcm from the surface and less surface roughness of 1.0 nm or less in terms of the P-V value, even though it had a high crystal defect density during the growth of a silicon single crystal. In addition, since it contains crystal defects required for gettering of impurities such as heavy metals in the bulk portion, semiconductor devices showing superior oxide dielectric breakdown voltage characteristics and carrier mobility can be produced and the yield of the device production can be improved, if the devices are produced by using the silicon wafer of the present invention.
As explained above, according to the present invention, there can be obtained a silicon wafer having few crystal defects on the wafer surface, a large thickness of the defect-free wafer surface layer and less microroughness on the wafer surface by using a specifically defined optimum composition of the heat treatment atmosphere in a method of heat treatment of silicon wafers. Therefore, the yield of the device production can be improved. In addition, since it becomes possible to minimize the amount of hydrogen used by the method of the present invention, the safety of the heat treatment operation can be secured.
In addition, according to the present invention, a heat treatment having both effects for eliminating defects such as COPs on wafer surfaces and improving haze can be performed in an extremely simple manner by using an improved temperature decreasing rate of the heat treatment in a method for heat treatment of silicon wafers using a rapid heating and rapid cooling apparatus. Thus, it becomes possible to obtain silicon wafers of higher quality compared with conventional ones with lower cost in a simple manner.

Method for thermally annealing silicon wafer and silicon wafer


In a medical catheter, a cutting device is provided, which has a rotary cutting tool positioned at a front end of a tube and which is axially displaceable relative thereto between a working position and a rest position. Each position is defined by a stop. The cutting tool is mounted on a rigid shaft received in a bearing member which interacts with the stops.

The invention concerns a medical catheter with a cutting device on the front end to insert into blood vessels. The cutting device has a rotary cutting tool, which has a diameter of the tube. The rotary cutting tool is movable to the front and back, but only a certain distance before it is stopped.
By this well known catheter it is disadvantageous that the position of the cutting device in relation to the front end of the tube is not definitely determined by the application of the catheter; among other disadvantageous is that, in the scope of the curved catheter the power shaft and the tube are often displaced against each other in the curvature. A cutting device which is too far out of the tube could cause undesired damage for the consequences, particularly damage to the vessel.


In order to provide a racket with strung netting, more particularly a tennis or squash racket, comprising a frame (10) which delimits a striking area (11) formed by strings tautly strung in the frame (10), a handle (14) as well as a connection piece (13) connecting the handle (14) with the frame (10), wherein, within the region of the racket (100), in which the racket (100) undergoes a strong deflection when striking, a resiliently mounted addition material (16) is fitted, in which these undesirable effects are, at low costs, either very largely eliminated or at least substantially reduced and wherein the striking properties are improved at the same time, it is proposed that the addition material (16) be configured in a rod-like fashion, that the addition material be disposed with its rod axis at a right angle to the handle axis and so as to lie in the plane defined by the striking surface (11).

Such a racket is known e.g. in the form of a tennis racket from the DE-B2-25 64 028.
Rackets of the known type possess, within the striking surface, an area determined by the geometry of the frame and the tautness of the strings, the so-called "sweet spot". If in the course of the striking, the ball strikes within this area, it can be controlled and played in a reliable manner, in which case the deflections of the vibration system formed by arm, hand and racket and, with that, the strain on the arm and the hand of the player is comparatively light.
However, the conditions are different when the ball impinges upon the striking surface outside the sweet spot. If the point of impact diverges in the longitudinal axis of the racket from the sweet spot, strong flexural vibrations are started up in the arm-hand-racket system which impair the feel for the ball and the control of the ball and stress the player more strongly. If the point of impingement diverges laterally, i.e. transversally to the longitudinal axis of the racket, torsional vibrations are produced which are connected with the pertinent negative repercussions.
In order to reduce or avoid the vibrations of the racket which have a negative effect, many diversely constructed vibration damping systems have already been developed.
Thus, from the DE-A-27 21 715, a damping system for tennis rackets is known which is accommodated in the hollow frame of the racket and which is essentially comprised of a cord or a wire which, by way of example, is enclosed inside the hollow racket frame in a resilient embedment.
Furthermore, from the publications U.S. Pat. No. 4,948,131, GB 2,225,539 A, EP 171 033 A3 and the EP 32 306 B1, cylindrical vibration damping elements are known which are inserted into the frame vertically to the racket surface and which are, in part, also resiliently mounted.
Cylindrical damping elements which are mounted in other spatial directions in or on the frame, are likewise known from the EP 32 506 A1 and the GB 2,225,537 A.
Occasionally, also different solution proposals are to be found, as in the DE-A-23 38 534, in which damping elements are disclosed which are comprised of a material attached to an elastic pin that is provided on or in the handle, or of an elastic strand which is bent in the manner of a "U" and, inter alia, which is disposed in the triangle between racket and handle in such a way that the legs of the "U" are secured to the frame, while the bent portion is able to swing freely.
According to the EP 275 805 B1, tennis rackets also form part of the state of the art in which, between handle and striking surface, plates coated with an elastic material are fitted to the frame so as to damp vibrations.
However, these damping means have proved themselves to be disadvantageous for a number of reasons.
The known vibration damping systems compensate flexural vibrations only to an inadequate extent since the damping materials, by virtue of their disposition in the space relative to the racket, are able to execute corresponding compensatory vibrations only inadequately.
The damping devices likewise impose a strain on the striking hand by their additional weight, which makes itself clearly felt when playing over a longer period of time without it being possible to profitably make use of the additional weight for the stroke.
In addition, for almost all damping systems, structural steps are necessary on the racket frames which, in part, are very expensive so that relevant frame constructions have to be developed first which forces the production costs up unnecessarily and, moreover, very largely rule out a refitting of rackets already fabricated.
That is why it is the technical problem of the present invention to provide a racket of the type stated in the beginning, in which these undesirable effects are either eliminated to a large extent or at least greatly reduced at a modest cost, while the striking properties are improved at the same time.
The technical problem is resolved by means of the features characterized in the claim 1.


An adapter for interconnecting in fluid communication a first connection site and a beneficial agent container having a closure. The adapter includes a plate having first and second connection site sides. A wall extends from the plate from the second connection site side and constructed to surround only the closure. This allows containers having varying sized bodies to be received. A cannula structure is rigidly secured in the plate and defines a flow path extending through the plate. The adapter can be provided in an assembly with the beneficial agent contained or in a drug delivery system.

The present invention generally relates to delivery systems for delivering a beneficial agent to a patient. More specifically, the invention relates to means for attaching vials to connection sites.
Many drugs are mixed with a diluent before being delivered intravenously to a patient. The diluent may be, for example, a dextrose solution, a saline solution or even water. Many such drugs are supplied in powder form and packaged in glass vials or ampules. Other drugs, such as some used in chemotherapy, are packaged in glass vials or ampules in a liquid state.
Powdered drugs may be reconstituted in a well known manner, utilizing a syringe which is used to inject liquid into the vial for mixing, the syringe eventually withdrawing the mixed solution from the vial. When a drug must be diluted before delivery to a patient the drug is often injected into a container of diluent after it is reconstituted, where the container may be connected to an administration set for delivery to a patient. More specifically, the diluent is often packaged in glass bottles, or flexible plastic containers such as are sold under the names MINI-BAG.TM. and VIAFLEX.RTM. by Baxter Healthcare Corporation of Deerfield, Ill. These containers have administration ports for connection to an administration set which delivers the container contents from the container to the patient. The drug is typically added to the container through an injection site on the container.
Drugs may be packaged separately from the diluent for various reasons. One of the most important reasons is that many drugs do not retain their chemical and physical stability when mixed with a diluent and thus cannot be stored for any substantial period of time. Also, drugs are often packaged separately from the diluent because many firms which manufacture drugs are not engaged in the business of providing medical fluids in containers for intravenous delivery, and vice versa.
Therefore, a doctor, nurse, pharmacist or other medical personnel must mix the drug and diluent. This presents a number of problems. The reconstitution procedure is time consuming and requires an aseptic technique. The operator must provide the proper diluent and a syringe before beginning. Often the powdered drug is "caked" at the bottom of the vial. Thus, when liquid is injected into the vial from a syringe the surface area of contact between the liquid and the powdered drug may be quite small initially, thus making the mixing procedure even more time consuming.
Because of the limited vial volume, the increasing drug concentration in the diluent makes it harder to finish the reconstitution process. The operator may attempt to solve this by repeatedly injecting solution into the vial, mixing and withdrawing the solution. This technique requires additional injections and movement of the syringe which increase the likelihood of contamination. Also, it is sometimes difficult to get all of the drug and/or liquid out of the vial, thus increasing the time required to perform the reconstitution procedure.
The reconstitution procedure should be performed under preferably sterile conditions. In addition to such a requirement making the operator justifiably more cautious and consuming more time, sterile conditions are often hard to maintain. In some instances, a laminar flow hood may be required under which the reconstitution procedure is performed.
Some drugs, such as some chemotherapy drugs, are toxic. Exposure of the operator to the drugs during reconstitution may be dangerous, especially if the operator works with such drugs on a daily basis and is repeatedly exposed to them.
A further problem is that the reconstitution procedure provides a source of confusion as to which container contains which drug. The diluent container should be marked with the drug with which it has been injected and the name of the patient to whom it should be delivered.
After a drug is reconstituted and withdrawn into a syringe barrel, the drug may in some instances be injected immediately into the intravenous system of a patient. More typically, however, the reconstituted drug is injected from the syringe into a larger container of solution as discussed above, for connection to an intravenous administration set. This is because often the drug reconstituted in the syringe is still at a concentration so high as to cause local toxicity in the veins of a patient near the injection site where the needle pierces the skin. This may create severe vein irritation which may be medically harmful.
Additionally, even though the proper dose of medication is in the syringe, immediate injection into the patient's blood stream may create a condition of systemic toxicity wherein the level of drug concentration in the patient's entire blood stream is dangerously high. Yet another reason for not making the injection from the syringe directly into the patient is that it creates an additional injection site into the patient, which may be painful for the patient and provides another opportunity for infection.
For these reasons, the reconstituted drug is more typically injected into a diluent container.
A patient may typically be administered a dextrose or saline solution from a large volume parenteral container, for example, such as a one liter container, delivered through an administration set such as a CONTINUFLO.RTM. administration set sold by Baxter Healthcare Corporation. If the reconstituted drug were injected into the large volume parenteral container, delivery of the drug would usually be made over too long a time period. Often, these large volume fluids are delivered at very slow flow rates.
More typically, the reconstituted drug is injected into a small volume parenteral container, such as a fifty milliliter container sold by Baxter Healthcare Corporation. This MINIBAG.TM. container is hung at a higher elevation than the large volume parenteral container and is connected by a secondary administration set to an injection site on the primary administration set. Because it is maintained at a higher elevation, the reconstituted drug in the small volume container is delivered, after which fluid from the large volume container begins to flow once more. By utilizing a small volume container connected to an administration set for delivery of the drug or other beneficial agent instead of a direct syringe injection, the drug is delivered over a preferred time period that tends to minimize negative side effects.
U.S. Pat. No. 5,049,129 discloses a passive drug reconstitution and delivery system with liquid flowing through an administration set. A receptacle mounted in the administration set is adapted for receiving a cartridge containing a beneficial agent. Also disclosed are adapter means for connecting the cartridge or a vial and the receptacle and an air flask within the administration set. One adapter includes an enlarged vial end constructed to snap fit about the mouth of a standard vial and a hollow shell configured to engage the receptacle. A sliding plate is positioned within the hollow shell and includes two separate cannulas acting as flow path means, for creating fluid paths through the vial to ensure proper mixing of the beneficial agent within the vial.
U.S. Pat. Nos. 4,804,366 and 4,850,978 disclose drug delivery systems with other adapters designed for use in the cartridges of those systems in which the cannula structures are rigidly mounted. However, in the disclosed adapters, the outside diameter of the vials useable therein is limited as a function of the interior diameter of the adapter.


A semiconductor optical head structure for accessing storage locations on an optical storage medium, such as an optical disk, for writing, erasing, and reading of information, including tracking-error detection and focusing-error detection systems is taught. Both error detection systems are optically and electrically separated to avoid any mutual inter- ference of the error signals, and all optical elements of the optical head are integrated on one chip. The focusing-error signal is generated by deflecting a separate beam (20A) out of an optical head and focusing it onto the surface of an optical disk and detecting the reflected portion thereof. The separate readout and tracking-error signal is generated by employing a light beam which is focused on the center of the pits of a track and detecting the diffracted portion thereof. Focusing-errors can be reduced by actuating the head perpendicular to the disk using a coil. If a tracking-error is measured, the head can be moved using an actuator, until the error is minimized. The required optical head can be grown on a compound semiconductor material, such as GaAs, using planar fabrication technology.

Initialized by the vast increase in information that needs to be processed, optical storage systems have become more and more important particularly because of their high storage density per area which can be more than 10 times as high as that of systems utilizing a magnetic medium. Video disk, digital audio disk, digital information storage disk, etc. are some examples of memory systems employing optical storage media.
In most optical storage systems rotating optical disks are used on which the information is digitally stored in concentric circular tracks in an ordered, predefined manner to allow chronological fast reading and fast random access to desired blocks of data.
For reading, normally an optical head is used to scan the disk, moving disk and head relative to each other. The head focuses a light beam onto the storage surface and detects the reflected portion thereof. The reflected beam is then transformed into an electric output signal.
To reduce reading errors, to improve the signal to noise ratio (S/N ratio), and to avoid optical head damage it is necessary to control the distance and inclination between the head and the optical-storage medium. For this purpose focusing-error and tracking-error detection is required.
For writing, normally the same optical head can be used to emit short pulses of high laser power heating the optical storage medium, e.g. an optical phase change medium to above the melting point, thus leaving marks of different reflectifity.
Two of the main requirements of optical heads, also known as pickup devices, are compact size to allow high speed access, and accurate tracking and focusing to allow high density data storage.
Starting from the earlier systems that employ external light sources, single optical lenses and photodetectors, which are bulky and massive, the trend is towards semiconductor optical heads constructed with integrated optics using waveguides, light- sensitive elements, grating couplers and lasers, thus allowing a reduction of size and weight.
One important step in order to reduce size was the employment of grating couplers. Because they are not as well known as other elements which have been described in numerous articles and books, we have listed references relating to grating couplers and their applications that are representative of the state of the art and which include:
Article "Grating coupler for efficient exitation of optical guided waves in thin films," published in Appl. Phys. Lett., Vol. 16, June 1970, pp. 523-525, gives a funda- mental description of the grating coupler principle.
Article "Waveguide grating lenses for optical couplers," published in Applied Optics, Vol. 23, No. 11, June 1984, pp. 1749-1753 discloses a method of constructing chirped grating couplers using a computer and an electronic beam exposure system.
Article "Aberration characterizations of a focusing grating coupler in an integrated- optic disk pickup device," published in Applied Optics, Vol. 26, No. 22, November 1987, pp. 4777-4782 reports on theoretical calculations of ray and wave aberrations of a focusing grating coupler (FGC).
With respect to tracking and focusing, the following references are the closest prior art known to the applicant:
"An integrated-optic disk pickup device," published in IEEE Journal of Lightwave Technology, Vol. LT-4, No. 7, July 1986, pp. 913-917, is an article where a monolithic- integrated optical-disk pickup device is proposed. This pickup device is constructed with integrated optics and has been realized on a silicon substrate. The pickup device comprises a twin grating focusing beam splitter (TGFBS), a focusing grating coupler (FGC), a wave guide, and several photodiodes (PD) in a film waveguide layer. A laser beam diverging from a butt-coupled external laser diode is focused by the FGC into one point on an optical disk. The reflected wave is collected and split by the TGFBS. Four PD's receive the back-coupled wave, and external electronic devices have to be employed to separate readout, focusing- error, and tracking-error signals.
U.S. patent U.S. Pat. No. 4 760 568, "Optical information processing device," discloses an optical head device similar to the device described in the above cited reference. The inventor has placed the laser into a hollow to reduce stray beams emitted from the laser, which are injected into the photodetectors placed next to the laser.
These known systems are based on silicon-tech- nology which does not allow the integration of a laser. The employment of other semiconductor materials, such as Gallium arsenide (GaAs), allowing the fabrication of optical pickup devices with integrated laser-structures, has not been suggested in the art. Hitherto an external laser had to be fixed to the device.
Some of the problems, caused by the employment of a separate laser are energy loss of the laser beam which has to pass through the interface between laser and device, and stray beams caused by inhomogeneities. In addition, it is necessary to adjust the position of the external laser with high accuracy during pack- aging.
In order to provide high density there is a demand for accurate tracking and focusing, based on tracking-error and focusing-error detection systems. The tracking- and focusing-error detection system of the devices described in the references consists of a focusing grating coupler deflecting the beam emitted from an external laser, out from the device and focusing it to form a single spot used to obtain the readout, tracking-error, and focusing-error signals. The three signals are dependent on each other and a final separation of the signals requires complicated and complex analyser circuitry. In addition to the required complexity, there is the problem that complete decoupling of the signals is not possible without interference. The accuracy of these error detection systems is limited by these interferences.
Despite the fact that the devices known to the applicant still suffer from a number of deficiencies, no suggestion has yet been made to make use of compound semiconductor materials, as GaAs for example, allowing the integration of all optical elements. Furthermore the employment of waveguide networks and optical and electrical separation of the error detection systems has not been shown before.

International Business Machines Corporation


An approach is provided for generating web-based augmented reality application viewer. A web-based server application receives a request from a web client for visualization information associated with a web application that renders a perspective-based display. The web-based server application facilitates a processing of the request to execute the web application. One or more web-based server applications at one or more web-based servers cause a generation of one or more images, one or more sequences of the one or more images, or a combination thereof based, at least in part, on the execution of the web application, wherein the one or more images, the one or more sequences, or a combination thereof depict a rendering of a user interface of the web application. The one or more applications transmit the one or more images, the one or more sequences, or a combination thereof as the visualization information for presentation.

Service providers (e.g., wireless, cellular, etc.) and device manufacturers are continually challenged to deliver value and convenience to consumers by, for example, providing compelling network services. In particular, these services can include location and navigation services on a mobile device (e.g., a smartphone). For example, mobile devices may include a display, location-based sensors (e.g., Global Positioning System (GPS) receivers), camera, and a processor, along with access to network-based databases of information. In addition, such devices can be programmed to provide a virtual view of geographic places or points of interest (POIs) and other objects via methods such as augmented reality, virtual reality, three-dimensional mapping, and/or other similar perspective displays. However, obtaining and processing the required information suitable for viewing in a user device requires significant processing power and resources. Accordingly, service providers and device manufacturers face significant technical challenges for enabling applications and services that support perspective-based displays to present POIs or other objects so that users can more easily request, receive and view an augmented reality presentation. These challenges can be particularly acute on mobile devices where display, computing, memory, and/or other resources may be limited.

Method and apparatus for web-based augmented reality application viewer


An electronic camera includes an image sensor having an imaging surface for capturing an object scene through a focus lens. When the object scene captured by the imaging surface includes a face portion of a human, a CPU designates, as a focal-point search area a first imaging area for covering an outline of the face portion. The CPU also designates, as a frequency-component detection area, a second imaging area that is smaller than the first imaging area and is for capturing an inner side of the outline of the face portion. Subsequently, the CPU obtains a high-frequency AF evaluation value and a mid-frequency AF evaluation value detected corresponding to the frequency-component detection area, and designates, as a lens moving range, a range different depending upon a relative ratio between the high-frequency AF evaluation value and the mid-frequency AF evaluation value. Thereafter, the CPU moves the focus lens within a designated range, and references a partial image generated on the imaging surface in a manner to correspond to the focal-point search area so as to search a focal point for the face portion.

1. Field of the Invention
The present invention relates to an electronic camera. More particularly, the present invention relates to an electronic camera that changes a distance from an optical lens to an imaging surface so as to adjust a focal point to a specific object.
2. Description of the Related Art
According to one example of this type of a camera, when a face of a human is photographed, a partial area including an outline of a face region is designated as a focal-point detection area. A position of a focusing lens is so controlled that a focal-point evaluation value calculated from an image within the focal-point detection area reaches a maximum. However, in the above-described camera, a moving range of the focusing lens is not changed depending upon a focusing degree at this current point. As a result, there is a possibility that focusing control takes time.

Electronic camera that adjusts a distance from an optical lens to an imaging surface so as to search the focal point


A perimeter security system for maintaining an object relative to a predefined boundary includes a plurality of water displacement devices configured to output fluid and to control a pressure of the outputted fluid when the object is within a first predetermined distance from the boundary. The system further includes a plurality of light sources configured to emit light toward the object when the object is within a second predetermined distance from the boundary. The system additionally includes an auditory system configured to emit an audible output when the object is within a third predetermined distance from the boundary, and a visual sensor configured to obtain images or video of at least a portion of the predetermined boundary and to transmit the images or video to a location other than the predefined boundary.

Perimeter security systems are known for use in a wide variety of applications, including for counterterrorism and border security. Generally speaking, perimeter security systems include drawbacks such as being unwieldy and stationary. Such systems serve as passive defenses rather than play a role in proactive response management. Moreover, such systems are typically standalone and not integrated with other aspects of emergency response management.

System and method for perimeter security


A vibration wave driving device comprises a vibrator having an electromechanical conversion device, a supporting member for supporting the vibrator, and a driven member brought into contact with a part of the vibrator driven frictionally by vibration excited in the vibrator: the supporting member comprising a vibration portion vibrating together with the vibrator, a fixation portion for fixing the supporting member, and a support portion for connecting the vibration portion with the fixation portion and supporting the vibrator; and the support portion being comprised of a laminate of sheets.

1. Field of the Invention
The present invention relates to a vibration wave driving device (typically, a vibration wave motor). In particular, the present invention relates to a vibration wave motor which is characterized by its supporting structure.
The present invention relates also to a structure of a vibration wave driving device, in particular to a structure which does not cause creak or a like noise.
2. Related Background Art
Various types of vibration wave driving devices, typically ultrasonic motors (vibration wave motors) are known, including rotary types and linear types.
The vibration wave driving device comprises, as basic structural elements, an elastic member constituting a vibrator, an electromechanical conversion device (or a magneto-stricting element), a supporter for supporting the vibrator, a driven member driven frictionally by contact with a part of the vibrator, a pressure-applying unit, and a bearing guide.
FIGS. 8A and 8B illustrate a constitution of a conventional linear type vibration wave motor (U.S. Pat. No. 7,432,633). FIG. 8A is a front view and FIG. 8B is a side view thereof.
Piezo-electric element 15 in a horizontally long rectangular shape is held by holder 19, energized by blade spring 20 toward driven member 17, and brought into contact with driven member 17 by driving contacts 16.
Holder 19 has side walls 22 for holding piezo-electric element 15 in the Y-direction, holder base 23, and pin 18 in a cylindrical shape projecting in the Y-direction from side wall 22.
Pin 18, which is nearly circular cylindrical, supports piezoelectric element 15 to be rotatable around pin 18 to follow smoothly the movement of driven member 17.
On application of an alternate electric field to piezoelectric element 15 by a power source and a power applying means not shown in the drawing, the vibrator containing piezo-electric element 15 is excited in a bending oscillation mode in the X-Z plane, and in a stretching mode in the X-direction simultaneously to move drive contacts 16 in an ellipsoidal movement. As the result, driven member 17 in contact with driving contact 16 is driven by blade spring 20 frictionally in the X-direction.
In the above conventional vibration wave motor, although the linear bearing guide is not shown in the drawing, with the parts upper from piezo-electric element 15 (members 15-23) fixed, the driven member 17 is guided to move only in the X-direction (in the direction of the driving force).
Such a driving system employing a linear type vibration wave motor is advantageous in that the construction is simple in comparison with the conventional driving system which converts the rotational movement of an electromagnetic motor into linear movement, and that the positioning accuracy can be improved by direct driving.
U.S. Pat. No. 7,425,770 discloses a linear type of vibration wave motor employing a magnetic force for pressure application.
Various types of ultrasonic motors are known, including rotary type ones and linear type ones.
The ultrasonic motors are classified roughly by the driving principle into stationary wave type ones and progressive wave type ones. The stationary wave type vibrator forms a stationary wave as a driving vibration mode by superposition of a bending vibration and a stretching vibration excited simultaneously. On the other hand, the progressive type vibrator forms similarly a progressive wave by superposition of a plurality of stationary wave vibrations.
Japanese Patent Application Laid-Open No. 2006-271143 discloses a progressive wave type of ultrasonic motor having the structure illustrated in FIG. 22.
In FIG. 22, the ultrasonic motor comprises vibrator 101 having piezo-electric member 102 and an elastic member 103, and moving member 105 in pressure contact with the driving face of elastic member 103. Flange 103c at the inner periphery of vibrator 101 is held and fixed between supporting members 106a, 106b to enable driving of moving member 105.
Moving member 105 is joined to shaft 108 with interposition of buffering member 107 like a rubber, and pressure spring 109 and output gear 110 fixed to shaft 108 apply a pressure to the frictional face between moving member 105 and vibrator 101.
The ultrasonic motor having such a structure is capable of outputting a larger torque at a lower speed with generation of less noise.
Japanese Patent Application Laid-Open No. 2001-268949 discloses an ultrasonic motor which has disk-shaped vibrator 113 supported at the center by support member 114 as illustrated in FIG. 23.
In this ultrasonic motor, the vibrator 113 is comprised of a combination of elastic member 111 and piezo-electric element 112, and vibrates in a vibration mode of primary vibration in the radial direction, in which the center of the disk becomes the center of the vibration and the outermost periphery of the disk becomes the loop. Therefore in this constitution, the node of the vibration, namely the center of the disk, is fixed not to prevent the vibration of the vibrator.    (Patent Document 1) JP-A 2006-211839; U.S. Pat. No. 7,432,633    (Patent Document 2) JP-A 2006-340443; U.S. Pat. No. 7,425,770    (Patent Document 3) JP-A 2006-271143    (Patent Document 4) JP-A 2001-268949
In the aforementioned U.S. Pat. No. 7,432,633, the support portion is comprised of pin 18, holding member 19 engaging with the pin to control the position and direction of the vibrator, and blade spring 20. The vibrator is pressed against driven member 17, whereby the position and the direction of the vibrator are controlled. This results in a larger thickness of the device, and is not suitable for miniaturization of the entire motor.
This structure contains no damping member within the combination of the vibrator, holding member, and blade spring. Therefore, a slight leakage of vibration of the vibrator or an undesired vibration transmitted from the friction part during the driving tends to cause an abnormal noise like a creak disadvantageously.
The above-mentioned conventional ultrasonic motors have problems as below.
In the ultrasonic motor described in Japanese Patent Application Laid-Open No. 2006-271143, the vibration member is made of a less-damping material owing to the characteristic driving principle of utilizing the vibration and friction. Further, the friction material is selected which has a high frictional coefficient, which tends to cause undesired vibration and noises.
Such phenomena become remarkable in cost down of the vibrator or the moving member owing to lowering of the face precision of the sliding face.
This prevents simultaneous achievement of improvement of the function such as the low noise and the low cost.
To overcome the above disadvantages, a damping rubber is attached on the back face of the vibrator (on the joint face to a flexible substrate). However, the damping rubber damps simultaneously the driving vibration of the vibrator to lower the motor efficiency disadvantageously.
Further, the ultrasonic motor disclosed in the above Japanese Patent Application Laid-Open No. 2001-268949 has also shortcomings of occurrence of creak or a like noise by stick slippage at a sliding portion, or a like cause.
To solve the above problems, the present invention intends to provide a vibration wave driving device having a simplified and thinned supporting structure to miniaturize the device and to lower the production cost.
The present invention intends also a vibration wave driving device which damps effectively undesired vibration excited in the sliding face without damping the driving vibration of the vibrator and prevents occurrence of creak or a like noise.


A camera is provided that includes a first panel including a plurality of lens units to capture an image, the lens units being disposed at one side of the first panel; a second panel that is rotatably connected to one edge of the first panel so that the first panel and the second panel rotate relative to each other between a first position contacting the one side of the first panel and a second position contacting the other side of the second panel; and an electronic mirror display unit to display an image if a signal is applied to the electronic mirror display unit and to reflect light if a signal is not applied to the electronic mirror display unit, the electronic mirror display unit being disposed at one side of the second panel corresponding to the one side of the first panel at the first position.

1. Field of the Invention
The invention relates to a camera, and more particularly, to a camera with a multi-function display that may perform various functions, such as a mirror function, a display function, and the like.
2. Description of the Related Art
Cameras that may capture still images or moving images include a display that may display an image of a subject to be captured or a captured image.
Korean Patent Application Publication No. 2005-0014561 discloses a camera with a rotating display. Thus, a user may observe the display from several angles. However, accommodation grooves need to be formed in a main body of the camera so as to install the display to be rotatable. Accordingly, the arrangement of components and a design of this camera are limited.


A pourable, plastic-bound explosive charge has a crystalline explosive substance embedded in a polymer matrix which includes a binder, a softener and a metal powder. The metal powder which is added in a proportion of 0.1 to 10 weight % has substantially spherical grains and is one or more of the following materials: vanadium, niobium, tantalum, chromium, molybdenum or tungsten.

This application claims the priority of German Application No. 100 58 705.4 filed Nov. 25, 2000, which is incorporated herein by reference.
This invention relates to pourable, plastic-bound explosive charges and a method of making the same, wherein a crystalline explosive material is embedded in a polymer matrix composed of a binder, a softener and further auxiliary substances.
Plastic-bound explosive charges have, despite their high efficiency, a relatively elevated insensitivity. They are composed of reaction polymers in which, prior to setting, crystalline explosive substances such as octogen, hexogen, pentaerythrite tetranitrate and the like are included. The polymer proportion is approximately 10-20 weight %.
It is a difficulty involving the manufacture of plastic-bound explosive charges that with the increase of the proportion of the explosive material, the viscosity of the mixture may increase to such an extent that pouring such a mixture is not possible. The theoretical limit for a pourable mixture lies at 92 weight %. It has been nevertheless found that the practical limit for a pourable mixture is at approximately 90 weight %. Further, explosive charges having a solid material proportion of such an extent are pourable only when the grain size of the explosive substance crystals used for the charge is within a predetermined diametral range; thus, as a result, a relatively cost-intensive sifting of the grains by screening has been necessary.
As discussed on pages 9 and 185 in the work entitled xe2x80x9cExplosive Substancesxe2x80x9d authored by J. Kxc3x6hler and R. Meyer (7th Edition, Weinheim, Basel, Cambridge, N.Y., VCH 1991), it is known to add aluminum powder to plastic-bound explosive charges. Such an addition results in a significant increase of calories by virtue of the intense heat generated by aluminum oxide. The cited work, however, is mute concerning an improvement of the viscosity of the explosive charge.

Pourable, plastic-bound explosive charges and method of making the same


A series topology is provided for the magnetic-field-generating coil and storage capacitor in the circuitry driving the coil of an MRI system. The coil and capacitor thus form a series resonant circuit that can deliver a sinusoidal current through the coil at a resonant frequency. A power source and switch are connected in series with the coil and capacitor, and current flow to the coil is initiated and interrupted by closing and opening the switch.

This invention relates to producing modulated gradient fields in magnetic resonance imaging (MRI) systems.
A variety of modulated gradient field waveforms are known to be useful in MRI systems. Some MRI systems, such as those disclosed in Rzedzian U.S. Pat. No. 4,628,264, produce a sinusoidally varying gradient field by sinusoidally driving a circuit comprising the gradient coil connected in parallel with a capacitor. The desired current is realized by selecting a capacitor/coil combination with a resonant frequency corresponding to the desired gradient field frequency, and driving the coil at that frequency with a sinusoidal voltage source. In this way, the voltage source supplies only a small fraction (1/Q, where Q is the quality factor of the resonant capacitor/coil circuit) of the coil current. The majority of the coil current comes from the resonant discharge of the capacitor.
Other MRI systems produce a steady gradient field by driving the gradient coil with a pulse of constant amplitude. The leading and trailing edges of these pulses rise and fall gradually, consistent with limits on the rate at which the current through the gradient coil can be changed. For example, trapezoidal pulses of coil current are often used.

Circuitry for driving field-generating coil of magnetic resonance imaging system


A generic device driver simulator having the knowledge of the device specific behavior moved out of simulator program code is disclosed. The generic device driver simulator includes a generic device driver for supporting application functions without device specific coding included therein, a database including device specific models of device drivers supported by the generic device driver and an interpreter for controlling the generic device driver according to the definitions of functions and data structures in the database. The generic device driver simulator also includes a watcher for defining watchpoints, the watchpoints identifying types of calls from the application. The watcher displays information when a watchpoint is triggered by a call from the application. The interpreter includes an input script for each device function or for multiple device functions that are supported by the generic device driver. The watcher supports the execution of an input script in the interpreter in response to a watchpoint being triggered.

1. Field of the Invention
This invention relates in general to a application verification, and more particularly to a generic device driver simulator for aiding in the development of applications.
2. Description of Related Art
An operating system executes on the various microprocessors, and serves as the interface between the various application programs and the hardware of the computer system. The operating system communicates with the various peripheral devices via input/output (I/O) control programs referred to as device drivers. A device driver acts as an interface between the operating system and the corresponding peripheral device. The device driver provides control commands to activate the peripheral device and to check the device status to determine when it is ready for a data transfer. The device driver also performs error checking when transfers are occurring to ensure that the transfer has completed successfully. Further, the device driver responds when the peripheral device indicates completion of the control commands.
To write a device driver program, a detailed knowledge of the peripheral device is required. Consequently, device drivers are typically provided by manufacturers of the peripheral device. In many instances, the actual peripheral device hardware may not be available while the device driver is being developed by the manufacturer. As a result, actual testing and any debugging changes that need to be made must wait until the actual hardware becomes available. However, this increases the development time for the application software.
It is possible to develop device specific simulators. However, developing and maintaining a device specific simulator can be cost prohibitive. The simulator is often as complex as the device itself because it encapsulates all knowledge of the device behavior. This results in high initial development cost, high maintenance cost, and difficulty keeping simulation in sync with real device.
It can be seen then that there is a need for a generic device driver simulator.
It can also be seen then that there is a need for a device driver simulator that has the knowledge of the device specific behavior moved out of simulator program code.

Generic device driver simulator and method


The present disclosure provides a method and a receiver for detecting synchronization in a Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system. The receiver includes a reception unit that receives a synchronization signal including an interference signal from at least one adjacent cell; and a synchronization detector that cancels the interference signal included in the synchronization signal based on a serial interference cancellation, and detects the synchronization based on the synchronization signal, from which the interference signal is canceled.

1. Field of the Disclosure
The present disclosure relates generally to detecting synchronization in a wireless communication system, and more particularly, to a method and an apparatus for detecting synchronization in a Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system.
2. Description of the Related Art
TD-SCDMA technology is obtained by combining Time Division Duplexing (TDD) and Time Division Multiple Access (TDMA) technology with Synchronous CDMA technology. Accordingly, TD-SCDMA technology has unique advantages, such as flexible frequency allocation, implementation of a low-priced transmitter/receiver, evolution of a network from Global System for Mobile communications (GSM), and the like, as compared with other 3G technologies such as Wideband Code Division Multiple Access (WCDMA) and CDMA2000.
In CDMA, which is robust against multipath fading and interference, cells can be distinguished from each other by using a midamble code and a chip-level scramble code. A midamble code is a channel training sequence used for channel estimation, whereas a chip-level scramble code is used to scramble transmission code symbols so that transmission symbols may be close to white Gaussian noise.
Also, when a TD-SCDMA system is an intra-frequency network, cell recognition or synchronization detection may be implemented by SYNC_DL (a downlink synchronization code) in a downlink pilot time slot and midamble codes. Further, users of different cells can be recognized by a scramble code and a midamble code.
However, when intra-frequency interference exists in a TD-SCDMA system, the TD-SCDMA system uses a SYNC_DL (the downlink synchronization code) in the downlink pilot time slot, a midamble code, and the like, which may be interfered with by other adjacent cells.
In other words, in an environment in which multiple cells use an identical frequency, while a synchronization code transmitted through a midamble code and a pilot time slot is broadcast by a serving cell and adjacent cells, the relevant cell may be affected by other midamble codes or synchronization codes broadcast by the adjacent cells.
A receiver may independently estimate a channel and detect synchronization by using signals received from multiple adjacent cells. Such a method for estimating a channel and detecting synchronization may cause interference to the estimated channel response signal and the synchronization detection signal. In the worst case, due to the interference, the receiver may fail to detect the synchronization.

Receiver and method for detecting synchronization in wireless communication system