A flywheel/motor assembly is disclosed that comprises a motor housing having a sidewall and an end wall extending substantially perpendicularly from the sidewall. The end wall enclose a motor assembly having a rotatable shaft extending therefrom. The motor housing has at least one air flow opening therethrough. A flywheel is coupled to the shaft, and includes a pulley side and a motor side opposite the pulley side, wherein the motor side is aligned substantially with the end wall and does not extend over the sidewall. A plurality of vanes are associated with the flywheel, wherein adjacent vanes form channels therebetween. A ring is coupled to the plurality of vanes and at least partially encloses the channels and forms exhaust ports away from the shaft. Rotation of the flywheel draws air through the motor housing's openings into the channels and out the exhaust ports. The pulley side may include balancing bores for receiving balancing material to balance the finished assembly. An angular interference fit between the flywheel and motor shaft may also assist in balancing the finished assembly. A ventilation fan system may also be connected to the shaft at an end opposite the flywheel.

Flywheels are used with various types of motor-driven equipment. Their primary purpose is to provide an opposing and moderating force by its inertia to any fluctuation of speed in the machinery which it revolves. Some flywheels have integral vanes or blades to produce air flow through the motor assembly that rotates the flywheel. But if the integral vanes are improperly configured they may generate excessive noise. Indeed, motor applications may utilize a flywheel that has an open-vane design which allows the air to roll off the vane axially as the flywheel rotates causing turbulence and resulting in excessive noise. Most of the air that starts at the inner diameter of the vanes never makes it to the exhaust tip of the blades and as such, this type of design is considered to be very inefficient. Moreover, since there is no ring closing the front area of the fan, there is no capacity or ability to incorporate an eye seal.
One attempt at improving a flywheel assembly is disclosed in U.S. Pat. No. 6,695,581. This patent discloses a fan-flywheel-pulley assembly used in conjunction with an electric motor. The pulley extends axially from the flywheel and drives a belt as is commonly used on treadmill exercise equipment. The flywheel includes an outer circumferential flywheel surface partially forming a plurality of circumferentially spaced openings. The flywheel may include a baffle that extends circumferentially and in close proximity to a cylindrical wall unit of the motor from an inner diameter to an outer diameter to limit a gap between the baffle and the cylindrical wall unit. This assembly may also include a radial fan disposed within the flywheel including a plurality of blades extending at least from the flywheel inner diameter to the outer diameter, wherein each opening is positioned between each adjacent fan blade. This patent also discloses that the pulley, the flywheel, and the radial fan may be integrally formed.
Although this disclosed configuration is an improvement in the art, it is believed that configuring the flywheel to surround the motor housing with the radial fan disposed away from the motor housing still allows for air flow inefficiencies. It is believed that this is a result of the cooling air having to travel a further distance through the flywheel assembly. Moreover, the gap between the baffle and the motor housing allows for "parasitic" airflow which generates noise and reduces fan efficiency. In addition, the gap between the baffle and the motor housing allows for internal fan noise to be emitted therefrom.
Yet a further drawback of the known flywheel motor assemblies is attributed to the imbalance problems in coupling the flywheel to the motor's rotatable shaft. When the flywheel is in an imbalance condition, undue stress is placed on the motor during operation and after a period of time, causes excessive wear on the motor and generates vibration. This generates additional noise and, of course, adversely effects the operation of the associated machinery. Indeed, it is believed that the shaft configuration of known assemblies does not sufficiently control flywheel positioning after assembly. In most assemblies, the flywheel is contained axially by seating against a small annular ring on the shaft face. This configuration is believed to be insufficient for controlling and maintaining radial alignment. In order to overcome this system imbalance after assembly, the flywheel motor assembly must undergo a final balancing operation. As will be appreciated, this is a time-consuming operation and does not always ensure that a balanced condition is obtained.
Therefore, there is a need in the art for a more efficient flywheel/fan assembly that improves air flow through a motor housing, reduces noise and also provides improved balance quality.

Motor/flywheel assembly with shrouded radial cooling fan


An improved lubrication structure is provided in an engine by optimizing the structure for recovering scooped oil for enhanced oil recovery efficiency. The oil, which has been scooped up and scattered by the rotation of a clutch, is captured within a concave groove provided within a cylindrical inner surface of a case cover facing the clutch. The captured oil is smoothly guided from the concave groove to an oil receiver of a crankcase via a bent upper edge part of an oil guide plate. The recovered oil passes through dropping holes of a recovered oil path and is supplied to a gear engagement part of a transmission system located below the recovered oil path.

1. Field of the Invention
The present invention relates to a lubrication system and method for a powertrain assembly, and more particularly relates to improved technology for a lubrication system in which lubrication is performed by mechanically scooping up oil accumulated in the lower part of a crankcase, and distributing the scooped-up oil to internal components of the powertrain.
2. Background of the Invention
In Japanese Utility Model Publication No. Hei 05-33686, a known lubrication structure is described, for an engine having a clutch mounted on a main transmission drive shaft that rotates in conjunction with a crankshaft. In the known structure, oil accumulated in the lower part of a crankcase is scooped up by the rotation of a clutch. The scooped oil is then received by oil receivers provided on the inner walls of the crankcase and a clutch cover. The received oil is then supplied, via a flow path, to an oil chamber extending above a transmission system. The oil from the oil chamber drops onto a gear engagement part of the transmission system on the main shaft and a countershaft (a power take-off shaft) via dropping holes formed in the oil chamber, and thereby the gear engagement parts are lubricated. A lubrication structure of this type has been disclosed, for example, in Japanese Utility Model Publication No. Hei 05-33686.
The engine described in the Japanese Utility Model Publication No. Hei 05-33686 is configured in such a way that a crankshaft is movably supported in a crankcase. The rotation of the crankshaft is transmitted to a main transmission drive shaft via engagement of gears and a clutch, and the rotation of the main shaft is further transmitted to a power take-off shaft (a countershaft) via a transmission system.
A lubrication structure is provided in which oil accumulated in the bottom (lower part) of the crankcase is scooped up by the rotation of the above-described clutch mounted on the main shaft, and in which the scooped oil is used to lubricate gear engagement parts of the transmission systems on the main shaft and the countershaft.
More specifically, concerning the lubrication for the gear engagement portion of the transmission system, oil which has been scooped up by the above-described clutch is received by oil receivers provided on the inner walls of the crankcase and a clutch cover and the oil is supplied to an oil chamber via a path.
A portion of the oil supplied to the oil chamber is dropped from the oil chamber onto the gear engagement parts of the transmission systems on the main shaft and the countershaft via a falling hole. In addition, the remaining scooped oil is supplied to the countershaft via a communicating path.
The oil receiver in the lubrication structure described in Japanese Utility Model Publication No. Hei 05-33686, which receives oil scooped up by the rotation of the clutch, is directly formed on the inner walls of the crankcase and clutch cover in the form of a concavity or a groove, and is integrally formed with the case and cover. Accordingly, selection of a structure or shape which has a sufficient oil recovery function as an oil receiver is restricted. Thus, it is desirable to enhance the recovery efficiency of the scooped oil in an oil receiving structure where the oil receiver is formed integrally with a case and cover.
In consideration of the above-described problems, it is desired to provide an improved technology for a lubrication structure in an engine, in which oil accumulated in the bottom (lower part) of a crankcase is scooped up via a rotator rotating in the crankcase and the scooped oil is used to lubricate a gear engagement portion and the like in the crankcase. An improved lubrication technology is one which enhances the lubrication efficiency of the gear engagement portion and the like by enhancing the efficiency of recovering the scooped oil, and which can be provided at low price and with simple structure modification.

Lubrication system and method, and engine incorporating same


A substrate is used to fabricate a low-cost laser diode array. A substrate is machined from an electrically insulative material that is thermally conductive, or two substrates can be bonded together in which the top substrate is electrically as well as thermally conductive. The substrate thickness is slightly longer than the cavity length, and the width of the groove is wide enough to contain a bar and spring (which secures the laser bar firmly along one face of the groove). The spring also provides electrical continuity from the backside of the bar to the adjacent metalization layer on the laser bar substrate. Arrays containing one or more bars can be formed by creating many grooves at various spacings. Along the groove, many bars can be adjoined at the edges to provide parallel electrical conduction. This architecture allows precise and predictable registration of an array of laser bars to a self-aligned microlens array at low cost.

1. Field of the Invention
The present invention relates to laser diodes and more specifically, it relates to a low cost laser diode array.
2. Description of Related Art
Laser diode arrays are used in a wide range of commercial, medical and military applications: materials processing (soldering, cutting, metal hardening), display technology/graphics, medical imaging (MRI) and surgical procedures (corneal shaping, tissue fusion, dermatology, photodynamic therapy), satellite communication, remote sensing, and laser isotope separation. In certain solid-state laser applications it is desirable to use laser diode arrays to optically excite, i.e., "pump," the crystal hosts. Diodes offer a narrow band of emission (reducing thermal lensing), compactness, high electrical efficiency and higher reliability as compared to flash lamps. Despite these numerous advantages, however, diode-pumped solid-state lasers (DSPSLs) have gained slow market acceptance due to the high cost associated with the laser diode array pumps. Significant diode array cost reductions would enable wide deployment of DPSSLs and new architectures to be realized that were previously cost prohibitive. In particular, low-cost diode arrays would bolster the inertial confinement fusion (ICF) and inertial fusion energy (IFE) programs that require low-repetition rate laser diode arrays in very high volumes.
Historically, much of the research and development in this area was devoted to solving diode material and fabrication issues in order to improve the yield and reliability of laser diodes. High quality InAlGaAs and InGaAsP laser diodes are now commercially available for pumping Nd:YAG at .about.810 nm. As much as 100 W/cm of peak power is possible under pulsed operation, and over 10,000 hours of continuous operation (CW) in commercial systems has been demonstrated at reduced power levels (20-30 W CW). Although these types of performance improvements have led to cost reductions in the past, there has not been a complementary improvement in the packaging technology, which is now limiting further cost reductions from being achieved.
To date, most packaging/heatsink schemes use a "rack and stack" architecture. In this method, individual laser bars are fabricated into sub-assemblies, and the sub-assemblies are then bonded together to produce larger two-dimensional arrays. Labor intensive steps associated with handling individual components prevents the production of arrays in large volume and in high yield. To alleviate this problem, a "monolithic" fabrication approach known as "bars-in-grooves" was proposed. This process was comercialized by Laser Diode Array Inc. and it represents the only "monolithic" technology that is commercially available today. There are trade offs associated with using a monolithic technique (e.g. by LDA Inc.) and the salient issues are discussed below.
The grooves must be deliberately over-sized to facilitate mounting the bars (as well as to allow for a range of diode bar thicknesses). Accurate final placement of the laser bar is therefore difficult to achieve as solder is used to fill in the void left by the over-sized grooves. This prohibits accurate collimation (tensing) of the laser diodes which is desirable in "high-brightness" applications that are often used in "end-pumped" geometries. More importantly, flowing solder around the bars can damage, or short-out bars which lowers yield and represents a serious liability to packaging costs of a completed array. Either that, or the strict process controls and/or lower yield of "suitable" bars that is necessary poses a cost penalty with this soldering technique. The following invention improves upon the limitations of the former "bars-in-grooves" method, while still benefiting from being a monolithic or quasi-monolithic approach. The placement of the laser diodes is well defined, and the soldering process can be extremely well controlled, or not used at all, which ensures a high yield that is crucial for a low-cost high yield production of laser diode arrays. It is emphasized that in the description by Karpinski et al. (U.S. Pat. No. 5,040,187), there is a method for flexing the substrate in order to facilitate loading laser bars. However, both the groove width and diode bar thickness would have to be controlled to such a high level of accuracy that this approach appears to be impractical. The present invention allows a practical implementation of a "solderless" contact because individual springs can accomodate any thickness variations of the individual components.

The Regents of the University of California


A surface of a compound semiconductor crystal of Group II-VI elements of Periodic Table can be cleaned to obtain a mirror surface suitable for epitaxial growth, without deteriorating the smoothness of the surface after etching. The feature of a method of cleaning a surface of the compound semiconductor crystal consists in using an etching solution consisting of an aqueous solution of a mixture of sulfuric acid and water in a proportion by volume of 1 to 10 parts of sulfuric acid to 1 part of water, saturated with potassium dichromate, etching the compound semiconductor crystal of Group II-VI elements of Periodic Table with the etching solution at a temperature within a range of 10 to 80.degree. C., and if necessary, washing with water at a temperature of from 10.degree. C. to the boiling point, methanol or isopropyl alcohol, or subjecting to ultrasonic washing or boiling washing in dichloromethane, trichloroethylene or acetone.

1. Field of the Invention
This invention relates to a method of cleaning a surface of a compound semiconductor crystal of Group II-VI elements of Periodic Table, such as ZnSe, ZnSSe, ZnS, ZnMgSe, ZnMgSSe, ZnTe, etc.
2. Description of the Related Art
It has hitherto been reported that ZnSe crystal is etched with an aqueous solution of NaOH or NH.sub.4 OH/H.sub.2 O.sub.2 or etched with a saturated solution of potassium dichromate in sulfuric acid at 90.degree. C. and treated with carbon disulfide, thereby cleaning the crystal surface (Cf. "J. Crystal Growth" 86 (1988), pp 324). Furthermore, it has been reported that ZnSe crystal is etched with a solution of bromine/methanol and subjected to ultrasonic washing in trichloroethylene (Cf. Japanese Patent Laid-Open Publication No. 18200/1984) and that ZnSe crystal is etched with a solution of sulfuric acid/ hydrogen peroxide/water and then cleaned with carbon disulfide to remove Se on the crystal surface (Cf. Japanese Patent Laid-Open Publication No. 109694/1993).
According to the above described cleaning methods, however, there arise disadvantages that the crystal surface is roughened, Se is deposited to be remarkably red, pits occur due to crystal defects, impurities such as Na, etc. in an etching solution remain and a clean, flat and mirror surface cannot be obtained. Thus, etching cannot be carried out in such a depth that a damage layer is removed. Consequently, an epitaxial thin film of high quality cannot be grown on a crystal obtained by the above described surface cleaning method.

Method of cleaning a surface of a compound semiconductor crystal of group II-VI elements of periodic table


An apparatus for expanding an existing repair sleeve in a steam generator to permit a new repair sleeve to be installed. The apparatus includes a variable cross-section elongated cylindrical capsule adapted to be positioned within the existing repair sleeve and an explosive charge inside the capsule whereby detonation of the charge expands the existing repair sleeve to permit the new repair sleeve to be installed. The variable cross-section of the capsule permits the explosive force to be "tuned" so that the existing tube expands evenly along its entire length, including the hard to expand ends of the existing sleeve, without overexpanding the tube. In the preferred embodiment, the apparatus includes a conduit attached to one end of the capsule and at least one sleeve position indicator associated with the conduit. The sleeve position indicator associated with the conduit may be a predetermined index mark on the outer surface of the conduit, a hard stop located between the conduit and the capsule or both.

(1) Field of the Invention
The present invention relates generally to an apparatus for repairing tubes of heat exchangers in a nuclear system and, more particularly, to an apparatus for expanding an existing repair sleeve in a steam generator to permit a new repair sleeve to be installed.
(2) Description of the Prior Art
The tubes of heat exchangers such as steam generators, oil coolers, reheaters or feedwater heat exchangers, in particular those of power plants, are subjected to high mechanical and thermal stresses as well as the corrosive action of the fluid which passes therethrough. The severity of the environment causes degradation of the tubes. The process of replacing tubes, particularly in power plants where down time must be limited, is both expensive and time consuming. Therefore, it is highly desirable to forestall replacement by repairing localized defects.
It is known to remove from service defective tubes by plugging them. However, plugging is only a limited remedy as it reduces the overall heat transfer surface area of the heat exchanger, and thereby materially reduces its efficiency.
Further, it is known to repair a localized tube defect by installing an inner sleeve which spans the defect. The sleeve is inserted through the end of the tube and thereafter attached near its ends to form a sealing engagement with the tube. Such expansion may be accomplished by mechanical rolling, hydraulic or explosive expansion. The sleeve can be welded into place by TIG, laser or explosive means.
A sleeve also may be used to repair a defective portion of a tube not at a tube sheet by expanding the sleeve into the tube to span the defect with a set of expansions on either side of the tube defect. In the free-span portion of the tube, where it is not backed by the tube sheet material, the risk of over expanding the tube is great if the expansion process is not tightly controlled. If an overexpansion occurs, the tube may crack either during the expansion operation or during the operation of the heat exchanger due to high stresses in the expanded region.
The acceptable leak rate between the sleeve and tube is an issue within all designs of heat exchangers. However, in radioactively contaminated heat exchangers, the leakage from the contaminated side of the tube to the clean side will result in the contamination of otherwise clean system components. In heat exchangers with dissimilar fluids on each side of the tube, such as an oil cooler, where one side of the tube is filled with water and the other with oil, leakage will result in the mixing of one fluid with the other, a potentially unacceptable situation that may result in damage to other system components. Finally, in pre-heater or feedwater heat exchangers, the leakage of fluid from one side of the tube to the other will result in the loss of efficiency of the unit. Based on the type of heat exchanger to be sleeved, an acceptable leak rate for the sleeve can be determined. In cases where the flow rate through the heat exchanger is high and the risk of contamination or damage to the system components is low, a higher leak rate may be acceptable.
In the past, once a tube was sleeved it was impossible to make another repair at the same location if the sleeve leaked. Worse still, if another leak occurred above the repair, there was no way to get a sleeve to the other leak. As a result the tube would have to be plugged. After too many tubes are plugged, the plant efficiency becomes so poor that the steam generators either must be replaced or the entire plant shutdown.
Other methods for addressing this problem have been proposed. These include the autogenous or filler weld repair of sleeves. These techniques can be very difficult to perform on degraded sleeves. Moreover, experience has shown that it is difficult to clean the area to be welded on degraded sleeves. Improper cleaning leads to problems with weld inclusions. Also, placing a sleeve within a sleeve has been proposed but the constriction that results would significantly degrade the performance of the tube.
Thus, there exists the need for an apparatus for expanding an existing repair sleeve to permit a new repair sleeve to be installed inside while, at the same time, reducing the possibility that the tube would be ruptured during the repair process.

Apparatus for repairing a steam generator tube


An internal combustion engine includes a cylinder having a cylinder inner surface, a cylinder head that cooperates with the cylinder inner surface to define a combustion chamber and has a head inner surface including an intake opening through which an intake gas is introduced into the combustion chamber, an intake valve that opens and closes the intake opening, an ignition plug provided on the cylinder head, and an intake drifting mechanism that causes the intake gas to drift toward an axis of the cylinder in the intake opening and generates a vortex flow in the combustion chamber. When the intake valve is opened, a minimum gap between the intake valve and the head inner surface is equal to or larger than a gap between the intake valve and the cylinder inner surface in a diametrical direction of the cylinder.

1. Field of the Invention
The present invention relates to an internal combustion engine with an ignition plug and a vehicle provided with the same.
2. Description of the Related Art
In spark ignition type internal combustion engines having an intake opening for suction of an air-fuel mixture and an exhaust opening for exhaust of combustion gases, it has been conventionally thought to be preferable to arrange an ignition plug around a center of a combustion chamber, that is, in the vicinity of a cylinder axis in order to improve the anti-knock property. Actually, however, parts other than an ignition plug are provided in an internal combustion engine, and an adequate anti-knock property cannot necessarily be obtained only by simply arranging an ignition plug in the vicinity of a cylinder axis while neglecting the layout of these other parts. It has been proposed to arrange an ignition plug to be offset toward an intake opening from a cylinder axis (see, for example, FIG. 7 of U.S. Pat. No. 5,027,761).
When an ignition plug is arranged offset toward an intake opening as in U.S. Pat. No. 5,027,761, a space on a side of the intake opening becomes smaller than the ignition plug on a cylinder head. As a result, when the amount of offset of the ignition plug toward the intake opening is large, the amount of open area of the intake opening must be decreased. When the open area of the intake opening is increased, however, a decrease in intake quantity is caused, so that a reduction in engine output occurs.

Internal combustion engine with ignition plug and vehicle provided with the same


A pair of pliers including a first plier element having a first handle portion and a first jaw portion defining a plurality of first protections. A deflected beam biasing element including a distal end is integrally formed with the first plier element. A second plier element includes a second handle portion, a second jaw portion defining a plurality of second projections, a contact surface having a first end and a second end, and a stop disposed proximate to the first end. A pivot element is provided to pivotally secure the first prier element to the second plier element so that relative pivoting movement of the first handle portion towards the second handle portion causes the first jaw portion to move towards the second jaw portion, the first end is disposed closer to the pivot pin than is the second end, and the distal end slidingly engages the contact surface. Force exerted by the finger portion against contact surface biases towards a normally open position with the first handle portion urged towards separation from the second handle portion, the first jaw portion urged towards separation from the second jaw portion, and the distal end urged towards the first end and bearing against the stop. Pivoting of the first handle portion towards the second handle portion causes the finger portion to deflect away from the pivot pin as the distal end slides towards the second end against biasing force. The position of the projections relative to the distal tips of the jaw portions, and the gaps between proximate pairs of the projections on the jaw portions can be selected to facilitate surrounding and subsequent gripping of a hub portion of a needle employed in a hypodermic syringe needle assembly.

1. Field of the Invention
The present Invention generally relates to pliers, and more particularly to pliers that include an element for biasing the pliers in an open position.
2. Description of the Prior Art
Pliers having a biasing element for urging the pliers towards an open position are well known, and are useful for grasping articles of preselected sizes and for repeatedly grasping similar articles. Generally, such pliers include plier components and a separate biasing element. Moreover, available pliers including elements biasing towards an open position generally do not limit the extent to which the pliers may be opened.
Despite the availability of such devices, there exists a need in the art for an improved pliers with biasing element that are capable of being used by the efforts of a single hand to pick up, grip, move, and release an object of a preselected size, yet limits the extent to which the pliers may be opened, and, In addition, are formed of a minimum number of components that are durable, inexpensive, and easily cleaned and maintained. There particularly exists a need in the art for an improved pliers particularly adapted for use in removing needles from hypodermic syringes.


A vehicle steering linkage includes an intermediate tube which extends across the vehicle between the steerable wheels of the vehicle. The intermediate tube transmits steering force from one steerable wheel of the vehicle to the steerable wheel on the opposite side of the vehicle. The ends of the intermediate tube are internally threaded and receive externally threaded portions of other parts of the vehicle steering linkage. A clamp placed around each threaded connection is tightened to prevent relative rotation between the threadedly interconnected parts. A plurality of retaining rings swaged on the intermediate tube locate the clamps axially on the intermediate tube. When the clamps are not tightened they can rotate freely on the intermediate tube between the retaining rings.

1. Technical Field
The present invention relates to a vehicle steering link assembly. In particular, the present invention relates to a vehicle steering link assembly which extends between two steerable wheels of a vehicle and which is adjustable in length.
2. Description of the Prior Art
Vehicle steering linkage connects the steering gear of a vehicle with the steerable wheels of the vehicle. The steering linkage includes one or more links which transmit steering force from the steering gear to the steerable wheels, to turn the steerable wheels in response to a driver input to the steering gear.
Medium to large trucks, such as Class 4 to Class 8 trucks, commonly employ a cross steer linkage. In a cross steer linkage, a drag link transmits steering force from the steering gear to the steerable wheel nearest the steering gear. A tie rod assembly including an intermediate tube extends across the vehicle from that steerable wheel to the steerable wheel on the opposite side of the vehicle. The intermediate tube transmits steering force to the steerable wheel on the opposite side of the vehicle.
In this known steering linkage, the ends of the intermediate tube commonly are internally threaded and receive externally threaded portions of parts attached to the steerable wheels. The threads on the opposite ends of the intermediate tube are of opposite hand. Thus, the overall length of the tie rod assembly is adjustable by rotation of the intermediate tube about its axis. This adjustment is used to set the toe of the steerable wheels of the vehicle.
It is common to employ a clamp placed around each threaded connection to prevent relative rotation between the intermediate tube and the threadedly connected parts once the vehicle toe is set. These clamps must be located axially a specific distance from the end of the intermediate tube in order to clamp properly. The clamps must also be free to rotate about the intermediate tube when loosened, so that the clamps may be set in a desired rotational position regardless of the rotational position of the intermediate tube, to avoid contact with other parts of the vehicle.
In a known method of making an intermediate tube for a medium to large truck such as a Class 4 to Class 8 truck, the end portions of a parent tube are reduced in diameter by swaging to a size selected to receive a vehicle part of a particular outer diameter. On each end portion, short beads of weld material are placed on the outer circumferential surface of the intermediate tube, on either side of the clamp location, to locate the clamp axially on the tube while still allowing the clamp to rotate. The beads of weld material extend circumferentially only for a small distance around the intermediate tube. This welding process adds a separate operation to the other operations needed in forming the tube, and is relatively expensive and time consuming. Thus, it is desirable to be able to locate the clamp axially on the intermediate tube in another manner.
U.S. Pat. No. 3,801,207 shows one manner of locating a clamp axially on a tubular member in a vehicle steering linkage. Several protuberances are stamped in a piece of sheet steel which is then curled into a tubular shape to form a turnbuckle. A clamp placed around a threaded connection between the turnbuckle and a tie rod end is tightened to prevent relative rotation between the threadedly interconnected parts. The protuberances stamped in the sheet steel are received in a channel in the clamp. The protuberances and the channel cooperate to block axial movement of the clamp relative to the turnbuckle. The clamp is rotatable on the turnbuckle.
On an intermediate tube for a medium to large truck, such as a Class 4 to Class 8 truck, it is not feasible to locate a clamp axially in the manner shown in U.S. Pat. No. 3,801,207. This is because an intermediate tube for such a vehicle is typically five feet or more in length, 11/4" or more in diameter, and has a wall thickness of up to 3/8". It is not feasible to stamp protuberances in such material, to cold form such a part, or to make a die set over five feet long to stamp and curl such a part.


A harness routing structure for a saddled vehicle includes a side body cover section, a center cover, a fuel tank having a fuel filler opening at an upper surface, and a refueling tray configured to be supported by the fuel tank, in the harness routing structure for a saddled vehicle used in the saddled vehicle having a straddling space disposed at an upper side of the center cover and through which a passenger passes his/her legs to ride the vehicle, a main harness extending from a front side of the straddling space to a rear side of the straddling space is routed below the center cover, is passed through a side of the refueling tray, and is routed between the side body cover section and the refueling tray.

In a low floor type motorcycle (a scooter type vehicle) disclosed in Patent Document 1, a fuel pump cover section is installed at an upper surface of a fuel tank disposed under a seat. Further, a clamp configured to fix a harness member is installed at a fuel pump cover section. In the vehicle, the harness member is fixed to a clamp and routed.
In addition, in the related art, the above-mentioned harness member is often routed in a state in which the harness member is supported along a vehicle body frame which has a high rigidity.

Harness routing structure for saddled vehicle


The invention pertains to an electro-optical connector module comprising a connection part, at least one optical transmitter circuit and/or optical receiver circuit and at least one electro-optical converter for respectively converting electrical signals into optical signals or vice versa. The module further comprises at least two substantially flat and substantially parallel electrically insulating sheets on which the transmitter circuit and/or receiver circuit and the converter are mounted. It is preferred that the connector module according, comprises at least one optical transmitter circuit, at least one optical receiver circuit and at least two electro-optical converters for respectively converting electrical signals into optical signals and vice versa, wherein the optical transmitter circuit and a first converter are mounted on a first sheet and the optical receiver circuit and a second converter are mounted on a second sheet.

The invention pertains to an electro-optical connector module comprising a connection part, such as a header or a receptacle for connection to a counterpart, at least one optical transmitter circuit and/or optical receiver circuit and at least one electro-optical converter for respectively converting electrical signals into optical signals or vice versa.
Such electro-optical connector modules are known from U.S. Pat. No. 4,149,072 and are more and more employed when high-rate transmissions (up to 10 Gbits/s) are required.
It is an object of the present invention to provide an improved electrical optical connector module of the kind described above.


A process for producing silicon-containing isocyanate compounds of the general formula II, comprising thermally induced decomposition of a silicon-containing carbamic ester of the general formula I at a pH of not higher than 8 in the presence of a catalyst of at least one metal or its compound.. General Formula I: ##STR1## General Formula II: ##STR2## wherein R.sup.1 to R.sup.6 and R.sup.8 each represent a hydrocarbon group, R.sup.7 represents an alkylene group having 1 to 8 carbon atoms, n, m and l represent an integer of 0 to 3 and m+n+l=3, and a, b and c represent integers of 0 to 3, 0 to 2, and 0 to 8, respectively.

1. Field of the Invention
The present invention relates to a process for producing silicon-containing isocyanate compounds by the thermally induced decomposition of urethane compounds which are carbamic esters containing silicon and at least one alkoxysilyl group or one siloxane unit.
2. Description of the Related Art
An isocyanate group has a high reactivity and reacts with an organic functional group having an active hydrogen such as a hydroxyl group, a primary or secondary amino group or a carboxylic acid group to form a urethane bond or a urea bond. Therefore, an organic polysiloxane having an isocyanate group introduced into the organic compounds is useful as a silicone modifier for organic compounds having an active hydrogen. Processes for efficiently producing the polysiloxanes containing an isocyanate group were proposed (see Japanese Patent Laid-Open No. 6-228161 (1994).
On the other hand, an alkoxysilyl group is also highly active, and polysiloxanes having such a functional group are useful as the silicone modifier. Further, it is known to use these polysiloxanes as a moisture curing agent, etc. Therefore, a silicon compound having an isocyanate group and at least one alkoxysilyl group in the organic compounds is highly valuable in the alkoxysilane modification of an active hydrogen-containing organic compound.
The isocyanate compounds are usually produced by phosgenation on an industrial scale. However, when a polysiloxane containing an amino group is reacted with phosgene, the intended polysiloxane-containing isocyanate compound cannot be obtained, since the siloxane bond is decomposed by hydrochloric acid formed as a by-product in the prior art. Also, when an alkoxysilylalkylamine having an alkoxy-silicon bond is reacted with phosgene, the bond between the alkoxy and silicon is decomposed by hydrochloric acid formed as a by-product. Additionally, an alcohol thus formed reacts with the isocyanate to lower the yield of the intended alkoxysilyl group-containing isocyanate compound, drastically. On the other hand, Japanese Patent Publication No. 5-8713 (1993) discloses a process wherein the reaction of alkoxysilylalkylamine with phosgene is carried out in the presence of a tertiary amine to neutralize hydrochloric acid formed as a by-product.
However, this phosgenation process has problems both in handling highly toxic phosgene and in the treatment of hydrochloric acid, which is formed as a by-product in the process and easily corrodes the apparatus. Under these circumstances, investigations were made for the purpose of developing an industrial process to be employed in place of the above-described process. For example, a process wherein a carbamatoorganosilane is gasified and then this compound is decomposed by heating in a gas phase is disclosed in Japanese Patent Laid-Open No. 7-258273 (1995). However, undesirable decomposition of this compound per se might occur in addition to the intended thermally induced decomposition, or side reactions such as the polymerization of the formed isocyanate might occur, since a considerably high heat is applied to the carbamatoorganosilane for the gasification thereof.
U.S. Pat. No. 3,607,901 discloses a process for producing silicon-containing isocyanate compounds. Although .gamma.-isocyanatopropyltrimethoxysilane is obtained by the thermally induced decomposition in Example 2 given in the specification, the yield of this product is only as low as 72.9%. It is pointed out that this process has another problem that since cyclic silyl carbamate formed as a by-product has a boiling point close to that of the intended product, the purification of the product is quite difficult.
Although various processes for producing isocyanate compounds containing silicon and an alkoxysilyl group were proposed as described above, these processes are those using highly toxic phosgene or vapor phase processes easily allowing undesirable side reactions in the gasification of the starting material. Thus, these known processes cannot provide the intended product with a high purity in a high yield and usually has economical advantages.

Process for producing silicon-containing isocyanate compound


The present invention provides compositions and methods for inducing an immune response in a subject. In particular, the present invention provides compositions comprising immunostimulatory ligands (ISL) and methods of inducing an immune response in a subject therewith. Compositions and methods of the present invention find use in, among other things, clinical (e.g. therapeutic and preventative medicine (e.g., vaccination)) and research applications.

Recent evidence indicates that two newly identified subsets of T lymphocytes, regulatory T (Treg) cells and IL-17-producing T helper (Th17), are playing reciprocal roles in immune responses. Treg cells act as suppressors of the immune response against tumors and infectious pathogens (Wilczynski et al. Front Biosci. 2008 Jan. 1; 13:2275-89.; Rouse & Suvas. J. Immunol. 2004 Aug. 15; 173(4):2211-5.; herein incorporated by reference in their entireties). Among various molecular mechanisms involved in Treg expansion, is the tolerogenic enzyme indoleamine 2,3 dioxygenase (IDO). This key enzyme has been shown to be involved in both tumor- and pathogen associated tolerance (Munn & Mellor. J Clin Invest. 2007 May; 117(5):1147-54.; Popov & Schultze. J Mol Med. 2008 February; 86(2):145-60).; herein incorporated by reference in their entireties). The role of Th17 cells in cancer has been less well characterized, however cytokine, IL-17, has been shown to increase recruitment of macrophages to tumor sites and stimulate generation of cytotoxic T cells, indicating that Th17 cells play an anti-tumor role (Kolls & Lindén. Immunity. 2004 October; 21(4):467-76.; herein incorporated by reference in its entirety). The evidence for the involvement of Th17 cells in anti-infection immune responses is abundant. There are strong indications that Th17 cells, their key cytokine, IL-17, as well as the Th17-expanding cytokine, IL-23, all play important roles in protection against pathogens (Jin et al. Autoimmunity. 2008 March; 41(2):154-62.; herein incorporated by reference in its entirety).
Attempts have been made in the past to inhibit Treg cells to improve immune response. Because Treg cells express high affinity IL-2 receptors (CD25), experiments using anti-CD25 antibodies, or IL-2 conjugated with toxins have been carried out in various experimental tumor models and in human trials with mixed results (Schabowsky et al. Curr Opin Investig Drugs. 2007 December; 8(12):1002-8.; herein incorporated by reference in its entirety). Similarly, depleting Treg cells by anti-CD25 antibodies failed to improve protective immunity against BCG in mice (Quinn et al. Eur J. Immunol. 2008 March; 38(3):695-705.; herein incorporated by reference in its entirety). Other immune stimulating approaches, using antibodies against CTLA-4 or GITR have been unsuccessful (Schabowsky et al. Curr Opin Investig Drugs. 2007 December; 8(12):1002-8.; herein incorporated by reference in its entirety). Thus, taken together, current strategies to inhibit Treg suffer from significant pitfalls.
Immunotherapy is an appealing anti-cancer treatment strategy. However, despite the fact that tumor cells express many immunogenic antigens, the immune system often fails to recognize or respond to them. This occurs because cancer cells utilize mechanisms that render the immune system tolerant, thereby evading immune recognition and/or eradication (Zou. Nat. Rev Cancer. 2005 April; 5(4):263-74; herein incorporated by reference in its entirety). Similarly, many pathogens have evolved sophisticated strategies to manipulate and evade their host immune system (Rouse. J Immunol. 2004 Aug. 15; 173(4):2211-5; herein incorporated by reference in its entirety). Consequently, attempts to establish preventive or therapeutic immunity using conventional immunization protocols have often met with disappointing results (Orme. J Leukoc Biol. 2001 July; 70(1):1-10.; Guinn et al. Mol. Ther. 2007 June; 15(6):1065-71; herein incorporated by reference in their entireties).
There have been no meaningful attempts to investigate the therapeutic utility of Th17 stimulation against tumors. In infectious diseases, on the other hand, there has been progress. The growing realization that the IL-23/Th17 axis is critical in both primary protective response and vaccination (Khader & Cooper. Cytokine 2008 February; 41(2):79-83.; herein incorporated by reference in its entirety), has prompted IL-23 gene transfer experiments in mice (Happel et al. Infect Immun. 2005 September; 73(9):5782-8.; Wozniak et al. Infect Immun. 2006 January; 74(1):557-65.; herein incorporated by reference in their entireties). The results have indeed confirmed that the IL-23 gene product can act as an adjuvant during BCG vaccination; however, while these findings are encouraging, the feasibility of mass administration of genes or their recombinant products is questionable, given the cost involved, the possibility of triggering neutralizing antibodies or allergic responses and lingering concerns about the safety of gene delivery.

Compositions and methods for inducing an immune response

THE REGENTS OF THE UNIVERSITY OF MICHIGAN


Provided are a circuit and method for sampling a valid command using a valid address window extended for a high-speed operation in a double pumped address scheme memory device. A method for extending the valid address window includes: inputting a valid command signal and a first address signal at the first cycle of a clock signal; inputting a second address signal at the second cycle of the clock signal; generating a decoded command signal and extended first and second internal address signals respectively in response to the command signal and the address signals; and latching and decoding the extended first and second internal address signals in response to the decoded command signal.

1. Field of the Invention
The present invention relates to a semiconductor memory device, and more particularly, to a circuit and method for sampling a valid command using an extended valid address window in a double pumped address scheme memory device.
2. Description of the Related Art
As the capacity of a memory device increases, the number of address signals for addressing memory cells increases. The address signals are provided to the memory device through address pins. In a synchronous memory device such as SRAM, command signals CMD and address signals ADDRs are input in synchronization with a clock signal CLK to the memory device, as shown in FIG. 1. The command signals CMD include signals /RAS, /CAS, /CS and /WE and the address signals ADDRs are, for example, 12 address signals A0 through A11.
To input the address signals A0 through A11 to the memory device, the 12 address signals are connected to the memory device through routing of a system board. The number of address pins of the memory device can be reduced from 12 (A0 through A11) to 6 (A0 through A5) in a double pumped address scheme. This simplifies system board design. Furthermore, internal power of a chip can be stabilized by using a power pad instead of an address pad removed due to the decrease in the number of address signal lines. Accordingly, the double pumped address scheme was developed.
In the double pumped address scheme, a valid command CMD and a first address ADDR1 are input at the first rising edge of a clock signal CLK and a second address ADDR2 is input at the second rising edge of the clock signal CLK, as shown in FIG. 2. In addition, a valid command is input at the first rising edge of the clock signal CLK and an invalid command is input at the second rising edge of the clock signal CLK. The 12 address signals A0 through A11 are divided into two groups and respectively set to the first address ADDR1 and the second address ADDR2. For example, the 6 address signals A0 through A5 are set to the first address ADDR1 and the 6 address signals A6 through A11 are set to the second address ADDR2.
FIG. 3 is a block diagram of a conventional double pumped address scheme memory device 300. Referring to FIG. 3, the memory device 300 includes a clock buffer 310, an address buffer 320, a command buffer 330, and an address latch circuit 340.
The clock buffer 310 receives an external clock signal CLK and generates a first internal clock signal CLK1. The address buffer 320 receives address signals ADDRs in response to the first internal clock signal CLK1 and outputs first and second internal address signals TAFi and TASi. The command buffer 330 receives command signals CMD in response to the internal clock signal CLK1 and generates a second internal clock signal PCLKD and internal command signals TCAS/TRAS/TCS/TWE. The address latch circuit 340 receives the internal command signals TCAS/TRAS/TCS/TWE and the first and second internal address signals TAFi and TASi in response to the second internal clock signal PCLKD and generates a row address RAi and a column address CAi.
FIG. 4 is a block diagram of the address buffer 320. Referring to FIG. 4, the address buffer 320 includes an input buffer 410 receiving the address signals ADDRs, an input sampler 420 sampling the output signal of the input buffer 410 in response to the first internal clock signal CLK1 and generating a clocked address signal C_ADDR, a delay 430 delaying the first internal clock signal CLK1, and a flip-flop 440 receiving the clocked address signal C_ADDR in response to the delayed first internal clock signal CLK1_D. The output signal of the input sampler 420 corresponds to the second internal address signal TAFi and the output signal of the flip-flop 440 corresponds to the first internal address signal TAFi.
FIG. 5 is a block diagram of the command buffer 330 and the address latch circuit 340. Referring to FIG. 5, the command buffer 330 includes an input buffer 510 receiving the command signal CMD, an input sampler 520 sampling the output signal of the input buffer 510 in response to the first internal clock signal CLK1, a first delay 530 delaying the first internal clock signal CLK1, a second delay delaying the first internal clock signal CLK1 to generate the second internal clock signal PCLKD, and a flip-flop 550 receiving the output signal of the input sampler 520 in response to the delayed first internal clock signal CLK1_D and generating the internal command signals TCAS/TRAS/TCS/TWE.
The address latch circuit 340 includes a command decoder 560 decoding the internal command signals TCAS/TRAS/TCS/TWE in response to the second internal clock signal CLK2 and generating a decoded command signal D_CMD, an address decoder 570 receiving the first and second internal address signals TAFi and TASi and generating decoded first and second internal address signals D_TAFi and D_TASi in response to the second internal clock signal PCLKD, and a latch 580 receiving the decoded first and second internal address signals D_TAFi and D_TASi and generating the row address RAi and column address CAi in response to the decoded command signal D_CMD.
FIG. 6 is a timing diagram for explaining the operation of the memory device 300 of FIG. 3. Referring to FIG. 3, the command signal CMD and a first address signal AF1 are input at the first rising edge C1 of the external clock signal CLK and a second address signal AS1 is input at the second rising edge C2. The internal command signal and the first and second internal address signals TAFi and TASi are generated at the third rising edge C3 of the external clock signal CLK. The second internal clock signal PCLKD is generated being delayed from the external clock signal CLK by a predetermined time. The decoded first and second internal address signals D_TAFi and D_TASi are generated in response to the internal clock signal PCLKD, and the decoded command signal D_CMD is generated. The decoded first and second internal address signals D_TAFi and D_TASi are latched in response to the decoded command signal D_CMD and the row address RAi and the column address CAi are generated.
The row address RAi and the column address CAi can be stably generated only when the decoded command signal D_CMD is generated within the window of the decoded first and second internal address signals D_TAFi and D_TASi. As shown in FIG. 6, the valid address window of the decoded first and second internal address signals D_TAFi and D_TASi corresponds to one clock cycle of the external clock signal CLK.
However, the first and second internal address signals TAFi and TASi input to the address decoder 570 have a skew between them in order to generate the decoded first and second internal address signals D_TAFi and D_TASi. Furthermore, the valid address window of the decoded first and second internal address signals D_TAFi and D_TASi becomes narrower as the operating frequency of the memory device 300 increases. Accordingly, a margin between the first and second internal address signals D_TAFi and D_TASi and the decoded command signal D_CMD is insufficient.

Circuit and method for sampling valid command using extended valid address window in double pumped address scheme memory device


The present invention relates to a system and method for enhanced phone-based collaboration (EPC), which enables users to quickly and easily enhance an ongoing phone call with a variety of interpersonal real-time two-way communications (IRTC).

Remote inter-personal real-time two-way communication (IRTC) became possible with the invention of the telephone over 100 years ago. Since then, due to technological progress, other forms of IRTC became possible. Currently, the most popular forms of IRTC include wireline and wireless telephony, audio/video conferencing, instant messaging, application sharing, desktop display sharing, whiteboard sharing, networked gaming and co-browsing. While different forms of the IRTC penetrated different markets, it is fair to say that generally telephony is pervasive in most business and personal activities while all the other forms of IRTC have a significantly smaller market penetration than telephony.
While telephony is currently the most ubiquitous and easy to use form of IRTC, end users would benefit by being able to augment a telephone conversation with other forms of IRTC. For example, during a phone conversation with a manager, a sales rep may want to jointly review and modify slides which will be presented at an upcoming client meeting. In another example, while a residential PC user talks to a software troubleshooting service representative, the user may want to add desktop sharing to the phone call in progress. In yet another example, two friends may want to jointly step through their vacation pictures while talking on the phone about recent vacations.
In all of these scenarios, communicating parties start with a simple phone call and then, as appropriate, add other forms of IRTC. As noted, currently the most common form of inter-personal real-time two-way communication is a wireline/wireless phone conversation where telephone parties use one of the following devices: a POTS phone, a PBX/CENTREX phone or a mobile phone. Other forms of IRTC, such as video conferencing, instant messaging, PC-based application sharing, desktop display sharing, whiteboard sharing, networked gaming and co-browsing, are becoming increasingly popular, but require the use of appropriate end-user devices, e.g. networked PCs, PDA's, notepads or advanced mobile phones.
One problem is that most IRTC interactions start with a regular phone call and there is no easy way to add other forms of IRTC to the phone call in progress. For example, in the scenario where a sales rep calls a manager to chat about an upcoming customer meeting and during the conversation the two decide to jointly review/update presentation slides, both of the parties must have access to networked PCs in order to collaborate on the presentation. However, in a typical environment it is not easy to establish joint editing of slides. Rather, this type of collaboration is generally done completely independently from the phone call in progress. The two collaboration participants must agree on using the same collaboration application, and then establish the collaboration session, typically using a completely separate addressing schema and collaboration session establishment signaling. The complexity associated with this operation is enough to discourage all but the most technically inclined end users.
In another example, similar difficulties arise when two friends while talking on the phone about their recent vacations would like to jointly view sets of vacation pictures. In a still further example, a house seller and real estate attorney lawyer having a phone conversation about the results of a home inspection decide to jointly prepare a response to the buyer's long list of repair requests. As with the above examples, there is no easy way to add collaborative document viewing and editing.
In particular, upon user A and user B agreeing to enhance the phone call, they must also agree on which software product will be used to enhance the phone call. This decision may require a technical savvy of network, firewall/NAT infrastructure that affects many of the existing software products. Some of the known choices include T.120 clients such as NetMeeting, IM products such as Yahoo! Windows Messenger, etc., and existing web conferencing solutions such as DCL Meeting Server, WebEx, etc.
To utilize these software products, users must have access to the software, which may require purchasing the software, software installation and establishing a billing agreement between the users and the service provider. Then the collaboration session must be established. This is accomplished by setting up the enhanced session manually using tools provided by the corresponding product, exchanging the information required to connect to the session and manually entering the information in the corresponding application. Such information may include IP addresses (NetMeeting or other T.120 clients), subscription IDs (IM products), and Conference Server URL with tokens such as conference key, and password (web conferencing solutions).
Exchanging the information necessary for entering the collaboration may further entail the web conference providers sending the information by e-mail distribution. While this procedure is viable for conferences scheduled in advance, this approach lacks real time characteristics required for ad-hoc spontaneous call enhancement.
Many of the current methods of enhancing the phone call are cumbersome and are not practical unless both users already subscribe to the same service and have already installed the corresponding software. Even if software installation and service subscription are not issues, the collaboration setup process involves many manual steps that diminish both usefulness and accessibility.
The manual process requires, at minimum, the users to perform session signaling twice: first using phones and phone numbers, then using PC based collaboration application and it's proprietary session signaling and addressing. However simple the application signaling is, it requires effort and needs to be learned by the users.
Therefore, there remains a need in the art for improvements in the technology of enhanced phone-based collaboration.


A semiconductor device and method of forming a patterned conductive layer on a semiconductor substrate are provided so as to prevent fluorine substance outflow from a fluorinated silicate glass (FSG) layer thereon and simultaneously so as to suppress back reflection of light waves into a photoresist layer during photolithographic processing. The substrate is coated in turn with a conductive layer, a dielectric (e.g., silicon dioxide) liner, a FSG layer, a silicon oxynitride layer preventing fluorine substance outflow therethrough from the FSG layer and also forming an antireflective coating (ARC), and a photoresist layer. The photoresist layer is exposed and developed to uncover pattern portions of the underlying silicon oxynitride layer. The uncovered pattern portions of the silicon oxynitride ARC layer and corresponding underlying portions of the FSG layer and dielectric liner are then removed, e.g., by a single dry etching step, to expose pattern portions of the conductive layer for metallization. Upon metallization, the substrate is provided with a combination of the FSG layer and silicon oxynitride layer, in which the silicon oxynitride layer prevents fluorine substance outflow therethrough from the underlying FSG layer to an overlying conductive layer.

In the fabrication of microelectronic semiconductor devices on a wafer substrate, such as silicon, to form an integrated circuit (IC), various metal layers and insulation layers are deposited thereon in selective sequence. The insulation layers, e.g., of silicon dioxide, silicon oxynitride (Sio.sub.x N.sub.y), fluorinated silicate glass (FSG), also called fluorinated silicon oxide, spin-on glass (SOG), etc., serve as electrical insulation between metal layers, e.g., intermetal dielectric (IMD) layers, as protective layers, as gap filling layers to achieve planarization (layer flatness) in the wafer substrate, and the like, as the case may be. The individual layers are deposited by conventional technique such as plasma enhanced chemical vapor deposition (PECVD), atmospheric pressure CVD, etc.
Typically, a first level metal layer, e.g., disposed on a silicon substrate containing devices, is separated by one or more insulation layers from a second level metal layer thereabove. This in turn may be separated by one or more further insulation layers from a third level metal layer thereabove, etc. These metal layers are interconnected by metallization through vias or small holes or apertures etched in the intervening insulation layers.
For this purpose, the stacked layers undergo photolithographic processing to provide a pattern thereon consonant with the IC design, e.g., to form vias. The top layer on the wafer substrate is covered with a photoresist layer of photo-reactive polymeric material for patterning via a mask. Light such as visible or ultraviolet (UV) light is directed through the mask onto the photoresist layer to expose it in the mask pattern. The polymeric material of the photoresist layer is transparent to the light yet photo-reactive to change its chemical properties, i.e., by photo-initiated reaction, thereby permitting its patterning.
An antireflective coating (ARC) layer such as an organic ARC layer, e.g., of light absorbing polymer, such as polyimide, is usually provided at the top portion of the wafer substrate to minimize reflection of light back to the photoresist layer for more uniform processing.
The photoresist may be of negative or positive type. In a negative photoresist, the exposed (polymerized) areas become insoluble while the unexposed (unpolymerized) areas dissolve in a later applied developer liquid. In a positive photoresist, the exposed (degraded) soluble areas dissolve in the developer liquid while the unexposed (insoluble) areas remain. In both instances, the photoresist material remaining on the wafer substrate forms the pattern to serve as a mask for etching in turn of the pertinent layers.
Where a layer material is of different physical and chemical characteristics from that of adjacent layers, its etching process is also different therefrom, e.g., in forming vias in dielectric layers to connect neighboring level metal layers. The etching is desirably anisotropic (high rate vertical direction etching and low rate or inhibited horizontal direction etching), as distinguished from isotropic (etching the exposed surfaces equally in all directions), for providing an etched structure of uniform vertical wall geometry or profile. Etching may be effected by wet etching (solution) or dry etching (plasma etching or reactive ion etching) technique, depending on the physical and chemical characteristics of the material being etched and of the neighboring material.
For maximizing the integration (connection) of device components in the available area on the wafer substrate to fit more components in the same area, increasing miniaturization is required. As narrower metal lines and closer pitch dimensions are needed to achieve increasingly dense packing of the components, they become more vulnerable to defects at the minute tolerances involved. This has become apparent as IC miniaturization has increased to what is now called very large scale integration (VLSI) at sub-quarter micron (0.25 micron, i.e., 250 nanometer (nm) or 2,500 angstrom), or less, dimensions.
By comparison, visible light has a wavelength spectrum of 400-700 nm (4,000-7,000 angstroms), and UV light has a wavelength spectrum of 100-400 nm (1,000-4,000 angstroms). Generally, mid UV (MUV) light has a wavelength of about 365 nm, while deep UV (DUV) light has a wavelength of about 248 nm or less.
At sub-quarter micron sizes, the desired high aspect ratios (depth to width) associated with photolithographic processing to form apertures or windows, fine conductive lines, etc., in various layers of the wafer substrate, require very strict tolerances to prevent undesired defects such as touching of closely spaced apart components that can cause short circuiting, etc.
During travel of the mask patterned incident light from the radiation source through the photo-reactive polymeric material of the photoresist layer, it is progressively absorbed as it photo-initiates reaction in the exposed pattern areas. As some incident light reaching the ARC layer is not absorbed thereby, but rather is reflected and scattered back into the photoresist layer, there is interference with the incident light and formation of standing waves.
Contaminants that are incompatible with the photoreactive polymeric material can migrate into the photoresist layer from the ARC layer or other vicinal layer. These contaminants can poison the photoresist layer, e.g., undergo interfering reactions therewith, causing non-uniformity of the reaction therein by extraneous chemical interaction with the polymeric material. This is commonly called photoresist poisoning.
These influences lead to formation of a photoresist footing where a positive photoresist is used, or of a photoresist pinching where a negative photoresist is used. Specifically, upon development, the exposed pattern areas of the photoresist layer have a photoresist profile or structure with non-uniform (non-vertical) side walls. After etching, the photoresist footing or photoresist pinching problem leads to imperfect transfer of the photoresist pattern to the underlying layer or layers, and ultimately limits the minimum spatial resolution since the etched structure is imprecise compared to the desired IC design.
FSG (fluorinated silicate glass) is one of the favorable low dielectric materials used for intermetal dielectric (IMD) application in sub-half micron (0.5 micron) semiconductor fabrication technology in connection with metallization techniques before so-called back end of the line operations (between metallization and sale). To deposit FSG, for example, either high density plasma (HDP) chemical vapor deposition (CVD) or plasma enhanced chemical vapor deposition (PECVD) is commonly used.
The dielectric constant achievable for FSG is about 3.3 depending on the fluorine concentration in the FSG film and the precursor used to deposit the FSG film. A higher fluorine concentration usually provides a lower dielectric constant. However, a higher fluorine concentration makes the film unstable because free fluorine tends to diffuse or migrate out of the film to adjacent layers in the IC.
Out diffusion of fluorine substances (including fluorine itself and attendant self-generating contaminant compounds thereof with other contaminating precursor constituents) from FSG can create bubbles that collect at interfaces with metal layers, resulting in metal peeling problems due to corrosion or poisoning, and the like. In many cases, FSG use is combined with post plasma treatment, e.g., plasma treatment using oxygen and nitrogen or nitrous oxide (N.sub.2 O), or the inclusion of a silicon dioxide cap layer to minimize fluorine substance out diffusion. However, fluorine substances, including fluorine itself, will diffuse well into silicon dioxide films and the diffusion length (penetration depth) thereof can be in excess of several thousand angstroms.
While the matter is not fully understood at this time, it is believed that contaminants such as hydrogen and nitrogen remain as precursor constituents in silicon dioxide based layers consequent their deposition, e.g., by PECVD technique, using silane (SiH.sub.4) in the presence of oxygen, nitrogen, nitrous oxide, and the like. In the presence of fluorine, it is considered that self-generating contaminant compounds thereof are formed with attendant hydrogen and/or nitrogen and/or other species that remain as contaminating precursor constituents. It is believed that fluorine and such self-generating contaminant compounds out diffuse to collect at a vicinal metal layer interface to cause such corrosion or poisoning and metal peeling problems.
As used in the specification and claims, the term "fluorine substance" contemplates fluorine-containing substances including both free fluorine itself and attendant self-generating contaminant compounds thereof with other contaminating precursor constituents such as hydrogen and nitrogen (i.e., fluorine-containing contaminant compounds).
A typical semiconductor fabrication technique using FSG as a low dielectric material for IMD application includes the steps of:
(1) metal layer deposition and patterning on a wafer substrate; PA1 (2) silicon dioxide liner deposition on the metal layer; PA1 (3) FSG layer deposition on the silicon dioxide liner; PA1 (4) silicon dioxide cap layer deposition on the FSG layer; PA1 (5) chemical mechanical polishing (CMP) of the silicon dioxide cap layer; PA1 (6) post CMP additional silicon dioxide cap layer deposition on the polished silicon dioxide cap layer (or post plasma treatment); PA1 (7) organic ARC layer deposition on the additional silicon dioxide cap layer (or plasma treated layer); PA1 (8) photoresist layer deposition on the organic ARC layer and photolithographic exposure and development; PA1 (9) organic ARC layer open etching; and PA1 (10) dielectric layer contact etching.
It is desirable to have an arrangement of FSG as an IMD in a semiconductor device in which out diffusion of fluorine substances is prevented so as to avoid metal peeling problems, especially if this is attained essentially without increasing the manufacturing costs.

Silicon oxynitride cap for fluorinated silicate glass film in intermetal dielectric semiconductor fabrication


Tank fittings are provided. A tank fitting has a coupling. The coupling includes a flange disposed between a first end and a second end of the coupling. External threads are disposed between the flange and the first end. A gasket is disposed on the coupling between the flange and the first end of the coupling so as to abut the flange. The tank fitting also includes a nut that is threadably attachable to the external threads of the coupling.

Adaptors are often used to connect piping within tanks, such as septic tanks, to external piping. For some septic-tank applications, an adaptor is used to connect piping within the septic tank, such as an internal baffle, e.g., a sanitary-tee fitting, to external piping. One method for connecting a sanitary-tee fitting to an external pipe involves disposing a flexible grommet in a hole in septic tank and pressing a pipe through the grommet so that the grommet seals around the pipe. The pipe is then connected to the external pipe and the sanitary-tee fitting. One problem with this configuration is that the pipe is not held secure within the grommet so that shifting earth or the like can damage the grommet and/or break the seal between the pipe and grommet, leading to leaks of septic tank contents.
Another method for connecting a sanitary-tee fitting to an external pipe involves a sanitary-tee fitting having a flange and a pipe stub extending from the flange. A gasket is disposed around a hole in the tank for forming a seal between the flange and the tank. The flange is aligned with the gasket and fastened to the tank so that the pipe stub passes through the hole and the flange compresses the gasket. A flexible coupling, e.g., of rubber or the like, is then disposed over the pipe stub of the sanitary-tee fitting and over the external pipe to interconnect the sanitary-tee fitting and the external pipe. One problem with this is that the flexible coupling allows the external pipe to move, e.g., due to shifting earth or the like. This causes the sanitary-tee fitting to deflect, which can cause the gasket to leak.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternatives for connecting piping within tanks to external piping.


A fastening element for friction welding onto a planar workpiece includes a nut head, a through-bore extending at least locally within the nut head, a friction welding face on one end side of the nut head, and a cutting device for introducing a drilled hole into the workpiece on the one end side of the nut head having the friction welding face.

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
DE 196 42 331 A1 describes a friction welding method with which a welded connection is established between an anchor bolt and an anchor rail. For this friction welding process, the anchor bolt has a concentric annular ring on one end side. With this annular ring, the anchor bolt is set on a surface of the anchor rail and is pressed with a contact force against the surface. A rotation apparatus rotates the anchor bolt, whereupon the resulting friction heat causes at least partial melting of the annular ring and/or of the surface of the anchor rail. The subsequent cooling process and the associated solidification of the melts establishes the friction-welded connection between the anchor bolt and the anchor rail.
DE 10 2004 034 496 A1 discloses a fastening element designed as a friction welding nut which is welded to a planar sheet-metal part through a friction welding procedure. The friction welding nut comprises a nut body with a threaded bore and an end side designed as a friction welding face. In order to establish the friction-welded connection, the friction welding face is pressed against the surface of the sheet-metal part and the friction welding nut is rotated. This friction welding nut makes it possible to provide, on the sheet-metal part, a one-sided screw connection for attaching a further component.
US 2004/0247380 A1 discloses a fastening element designed as a press nut to be pressed into a planar sheet-metal part. This press nut comprises a nut head with a threaded bore and a conical shaft element adjoining the nut head. For pressing the press nut into the sheet-metal part, the press nut is positioned on a surface of the sheet-metal part and an anvil for the press nut is positioned on the opposite side of the sheet-metal part. As the press nut and the anvil are pressed together, the shaft element is pressed into the sheet-metal part and a through-hole is punched into the sheet-metal part. The conical configuration of the shaft element with a notched outer contour means that the press nut is held in the stamped hole such that it cannot rotate. The stamped hole permits access from both sides to the press nut pressed into the sheet-metal part, but a press connection of this kind has a lower tensile strength than a friction-welded connection. Moreover, the pressing procedure requires an additional anvil.
In view of the prior art described, there is room for improvement in the field of fastening elements to be attached to a workpiece.

Fastening element for friction welding and method for friction welding a fastening element onto a planar workpiece


The present invention provides waterborne crosslinkable polymer compositions encompassing (A) functional latex polymers containing at least one pendant ethylenically unsaturated functional group, (B) a silicon hydride compound containing at least two reactive hydrogen atoms, and (C) a catalyst suitable to attain a crosslinked film.

The present invention relates to crosslinkable waterborne polymer compositions suitable for coatings. In particular, the present invention relates to waterborne compositions encompassing a functional latex polymer containing an ethylenically unsaturated moiety, a silicon hydride material and a catalyst suitable for reaction of the silicon hydride with the functional latex polymer.
The increased awareness of the effects of volatile organic solvents on the environment is causing a re-evaluation of the use of solvents in coatings. As a result, many coatings manufacturers are switching from organic to water based coatings systems. The typical strategy used to produce waterborne coatings which form hard, tough films, has been to produce an emulsion polymer with a glass transition temperature (Tg) above room temperature and plasticize this polymer with a solvent to lower the Tg of the polymer and thereby reduce the film formation temperature of the latex. The solvents used to lower the glass transition temperature of the polymer are known in the industry as coalescing aids. The coalescing aids present in a typical thermoplastic paint composition increase the volatile organic content (VOC) of the paint.
An alternative way of producing a coating having hardness and toughness properties is to produce a latex with a Tg below room temperature which is capable of forming a film at room temperature, and then crosslinking the film to give film toughness and solvent resistance properties. In the published literature, there are many examples of curing chemistries that have been applied to solvent based systems. However, chemistries suitable for solvent based systems are not always applicable to waterborne systems.
The application of hydrosilation reactions in crosslinking silicon polymer systems is well known in the literature. An article published by Batch et al. in Rubber Chem. Technol., 64(2), 218-33 (1991) describes the hydrosilation reaction as applied to silicon systems. Also a review of this technology can be found in Silicone Rubber in Powder Form, Swanson, Leicht & Wegener, Amer. Chemical Society, Rubber Div., October 1974. Applications of this chemistry to non-silicon systems is limited.
EP Application 94109495.5 discloses a curable resin composition containing a homo- or copolymer of an organohydrogenpolysiloxane macromonomer, an allyl group containing polymer and a hydrosilation catalyst. The above patent, however, teaches melamine resin compositions which are not waterborne and does not refer to the use of hydrosilation chemistry in curing waterborne latex polymers.
U.S. Pat. No. 5,321,082 describes curable resin compositions comprising a polymer having a plurality of alkenyl groups, an organohydrogenpolysiloxane, a polymer having a plurality of alkenyl groups and a hydrosilation catalyst. This patent does not refer to compositions that cure waterborne latex polymers.
U.S. Pat. No. 4,962,165, refers to a process for making silicon-containing polymer particles by a suspension polymerization. The polymer particles of this patent are prepared by polymerization of functionalized silicon-containing material, containing at least one copolymerizable functional group per siloxane chain. The functionalized siloxane-containing material is then suspension polymerized to form crosslinked silicon rubber particles. The functionalized siloxane-containing material of this patent may alternatively be copolymerized with active surfactants by suspension polymerization or coated or encapsulated with other copolymerizable unsaturated monomers, as by an emulsion copolymerization, after the silicon-containing material has been crosslinked to modify the surface properties of the siloxane-containing material. The '165 patent however, does not use hydrosilation reactions as a method of controlling crosslinking reactions since the particles in the patent are pre-crosslinked.
EP 0 702 068 A1 Application refers to a method of forming multilayer coatings on a substrate such as automobile bodies. The method of EP 0 702 068 A1 Application comprises the steps of applying a pigmented basecoat composition onto the substrate, applying a clear topcoat composition onto the basecoat and curing both coats individually or simultaneously. The clear topcoat composition comprises a resin having pluralities of both hydrosilyl groups and alkenyl groups in the molecule, or a blend of resins having a plurality of hydrosilyl groups in the molecule with a resin having a plurality of alkenyl groups in the molecule. In addition the method of the EP 0 702 068 A1 Application requires a catalytically effective amount of a hydrosilylation catalyst. None of the compositions are waterborne latex polymers.
EP 0 602 933 A2 refers to a hydrosilylative composition comprising an acrylic polyester or epoxy resin having at least two alkenyl or alkynyl groups in a molecule, and an organic silicon compound having at least two hydrogen atoms each directly attached to a silicon atom in a molecule, a hydrosilylation catalyst, and at least one of an organic iron compound and an organic aluminum compound. None of the compositions are waterborne latex polymers.
EP 0 566 095 A1 and corresponding U.S. Pat. No. 5,321,082 refer to a curable resin composition containing a polymer having a plurality of alkenyl groups, and organohydrogenpolysiloxane having a plurality of hydrosilyl groups, a polymer having a plurality of alkynyl groups, and a hydrosilylation catalyst. The composition of the patents is stable at room temperature but is crosslinkable at an elevated temperature. None of the compositions are waterborne latex polymers.
EP 0 450 844 A2 refers to a curable resin composition which comprises an organic resin containing at least two alkenyl groups per molecule and having a specific molecular weight, and organohydrogen polysiloxane containing no less than two Si--H bonds per molecule and a platinum catalyst. The organic resin is preferably chosen from at least one of acrylic, polyester and epoxy resins. The compositions of this patent can be cured at low temperatures without shrinking to give a product having good water resistance, chemical resistance and recoatability. None of the compositions are waterborne latex polymers.
U.S. Pat. No. 5,539,073 describes the production of waterborne polymers that contain pendant allyl groups. The patent further describes the oxidative cure of such latexes with metal driers, but does not teach the use of hydrosilation reactions.
The prior art does not disclose any waterborne crosslinkable polymer compositions which may be cured using a hydrosilation reaction. Thus, there still exists a need for waterborne polymer compositions suitable for crosslinking by hydrosilation, without the use of coalescing agents or other compounds contributing to the volatile organic content (VOC).

Waterborne silicon hydride crosslinkable latex compositions and methods of preparing the same


A method for scheduling tasks includes receiving input that was acquired using one or more data collection devices, and scheduling one or more input tasks on one or more computing resources of a network, predicting one or more first tasks based in part on the input, assigning one or more placeholder tasks for the one or more predicted first tasks to the one or more computing resources based in part on a topology of the network, receiving one or more updates including an attribute of the one or more first tasks to be executed as input tasks are executed, modifying the one or more placeholder tasks based on the attribute of the one or more first tasks to be executed, and scheduling the one or more first tasks on the one or more computing resources by matching the one or more first tasks to the one or more placeholder tasks.

Task management in distributed computing is the process by which scheduling and recording of processing tasks is done. A processing task is a quantity of work or responsibility that may be assigned to one or more computing devices. In turn, the devices execute code and/or otherwise apply an algorithm to perform a given processing task. For example, in a seismic context, noise may be attenuated in shot gathers by applying noise mitigation algorithms. Processing tasks in this type of application may thus include applying the noise attenuation algorithms to the data, sorting the data into shot gathers, applying algorithms to individual shot gathers, starting processes on compute nodes that apply algorithms to process shot gathers, writing shot gathers with noise attention applied to disk, etc. A distributed scheduling engine may orchestrate scheduling one or more of these tasks during the execution of the parallel job.
For complex processing sequences, there may be processing tasks derived from other processing tasks. For example, the first processing task may be to read the data into memory, the second processing task may be to sort the data, and the next sequence of processing tasks may be to apply noise attenuation algorithms to each shot gather in the sorted data. The tasks to apply the noise attenuation algorithms are derived from the task to sort the data. In this example, a single processing task is used to derive several processing tasks.
For more complex processing scenarios, some processing tasks may be derived from one or more input tasks. For example, if a processing sequence were extended to include resorting shot gathers to common image point gathers, applying algorithms to correct for the effects of signal propagation as a function of offset, and summing traces in a common image point gather to produce output traces, many shot tasks may correspond to a single common image processing task.

Seismic processing task predictive scheduler


The present invention provides for microporous ceramic materials having a surface area in excess of 70 m.sup.2 /gm and an open microporous cell structure wherein the micropores have a mean width of less than 20 Angstroms and wherein said microporous structure comprises a volume of greater than about 0.03 cm.sup.3 /gm of the ceramic. The invention also provides for a preceramic composite intermediate composition comprising a mixture of a ceramic precursor and finely divided silicon carbide or silicon nitride, whose pyrolysis product in inert atmosphere or in an ammonia atmosphere at temperatures of up to less than about 1100.degree. C. gives rise to the microporous ceramics of the invention. Also provided is a process for the preparation of the microporous ceramics of the invention involving pyrolysis of the ceramic intermediate under controlled conditions of heating up to temperatures of less than 1100.degree. C. to form a microporous ceramic product.

1. Field of the Invention
The present invention relates to open pore, microporous ceramic materials and their method of manufacture.
2. Description of Related Art
Porous materials play a particularly important role in a number of chemical processing industries and applications. Separations based on membranes are critical in such fields as chemical recovery, purification and dehumidification. Porous oxides (e.g., clays, silica, alumina and zeolite) are the materials of choice as catalysts or catalyst supports in chemical and petroleum processing reactions such as hydrocracking, hydrodesulfurization, reforming, and polymerization.
With respect to membrane technology, inorganic membranes offer a number of advantages over polymeric membranes which are typically limited to uses at temperatures below about 250.degree. C. These include: i) higher operating temperatures, ii) greater structural integrity and hence the ability to withstand higher pressure differentials and backflushing, and iii) improved resistance to corrosion. Porous oxide (e.g., aluminum oxide) and carbon membranes offer some of these characteristics, but advanced materials are still required for improved strength, toughness, structural integrity, temperature stability, water and oxygen resistance, thermal shock resistance, molecular selectivity to small molecules and gases, and high flux.
Similar considerations apply to clay and metal oxide type catalysts or catalyst supports, particularly as relates to stability and thermal shock resistance at temperatures above about 500.degree. C.
Ceramic materials of the Si--C, Si--N, Si--C--N, Si--B--C, Si--BN, Al--N, Si--Al--N, B--Al--N and related types appear to offer many of the properties set forth above. However, the solgel synthesis methods typically used to prepare porous oxide membranes or catalyst supports are incompatible with the preparation of ceramics of the type described above because of the need to use water in their preparation. Sintering or reactive sintering of these ceramics likewise produces materials with pore sizes of from about 0.1 to about 1000 microns which are non-uniform and generally too large for effective molecular separation and other uses described above. Chemical vapor deposition can produce microporous ceramic layers, but this tends to be an expensive, high temperature process with limited ability to tailor complex ceramic compositions.
Recently, researchers have discovered improved methods for preparing ceramics using ceramic precursors as starting materials. A ceramic precursor is a material, a chemical compound, oligomer or polymer, which upon pyrolysis in an inert atmosphere and at high temperatures, e.g., above about 200-400.degree. C., preferably above 700-1000.degree. C., will undergo cleavage of chemical bonds liberating such species as hydrogen, organic compounds and the like, depending upon the maximum pyrolysis temperature. The resulting decomposition product is typically an amorphous ceramic containing Si--C bonds (silicon carbide), Si--N bonds (silicon nitride) or other bond structures which will vary as a function of the identity of the ceramic precursor, e.g., Si--C--N, Si--N--B, B--N, Al--N and other bond structures, as well as combinations of these structures. Crystallization of these amorphous ceramic products usually requires even higher temperatures in the range of 1200-1600.degree. C.
The pyrolysis of various ceramic precursors, e.g., polycarbosilanes, polysilanes, polycarbosiloxanes, polysilazanes, and like materials at temperatures of 1200.degree. C. and higher to produce ceramic products, e.g., silicon carbide and/or silicon nitride, is disclosed, for example, in M. Peuckert et al, "Ceramics from Organometallic Polymers", Adv. Mater. 2, 398-404 (1990).
During pyrolysis, preceramic precursors such as described above liberate various gaseous decomposition species such as hydrogen and organic compounds, including methane, higher molecular weight hydrocarbon molecules, and lower molecular weight precursor fragments. These gases tend to coalesce within the preceramic matrix as they form, resulting in a bulking or swelling to form a voluminous mass of low bulk density. These entrained gases can also lead to the formation of smaller gas bubbles within the developing ceramic mass as the preceramic precursor crosslinks and hardens, resulting in a reduced density ceramic having a mesoporous or macroporous closed-cell structure, without development of a significant amount of open celled micropores.
Where dense, non-porous ceramic materials are sought using ceramic precursors yielding high gas volumes, it is often necessary to conduct the pyrolysis over a very long period of time with very gradual incremental temperature increases and/or under vacuum to assist in removal of these gaseous species at temperatures where they are formed.


A unique method has been developed which can show the presence of fractures in an Earth formation as a mappable attribute. This method uses the frequency spectra derived from P-wave seismic data over a pair of specific time windows above and below a seismic horizon or reflector of interest to infer the presence or absence of these geologic fractures based on an attenuation of high frequencies. The method produces a parameter value (t*) which is proportional to the shift in frequency spectra amplitudes (i.e., energy) from higher frequencies to lower frequencies, that is, from a time-window above a horizon or reflector of interest to a time-window below the horizon or reflector of interest.

The subject matter of the present invention relates to a method and apparatus responsive to a plurality of seismic data for generating a map illustrating data representative of a frequency shift of a plurality of seismic signals when said seismic signals propagate through a layer of fractured rock in an Earth formation.
Geologic formations containing fractures are an important source of hydrocarbon accumulations and an interesting target for geophysical exploration. The presence of fractures in a geologic formation will act as a high-cut filter with respect to the seismic wave that is propagating through the layer of fractured rock in the Earth formation. This produces a measurable and mappable change in the frequency spectra of the seismic signal propagating above the fractured zone compared to the frequency spectra of the seismic signal propagating below the fractured zone.

Method and apparatus for detecting fractures using frequency data derived from seismic data


A light signal detecting circuit which receives via a light detector light radiated from a laser diode oscillated as a multimode by a high frequency driving signal and reflected from an optical disk, amplifies a current signal proportional to the amount of the received light to a light detecting signal and outputs the signal, further includes a phase sensitive detector for selectively outputting from the current signal only a signal component having the same frequency and phase as the high frequency driving signal for driving said laser diode. Accordingly, a signal component with different frequency and phase from the output of laser diode is intercepted, and only a signal component with the same frequency and phase as the output of laser diode is detected.

The present invention relates to an optical disk player, and more particularly to a light signal detecting circuit for a magnetooptical disk player.
In general, a magnetooptical disk player reproduces recorded information by irradiating laser beam focused in a minute spot with the diameter of about 1 .mu.m onto the magnetooptical disk, then detecting the information recorded in the magnetization direction of magnetooptical material by converting the information to the rotation of polarized surface according to Kerr or Faraday effect that explains the interaction between light and magnetization.
Referring to FIG. 1, such magnetooptical disk player irradiates laser beam from a semiconductor laser diode 2 onto a magnetooptical disk 6, and detects light reflected from the magnetooptical disk by converting the rotation variation of the polarized surface to light intensity variation by an analyzer such as polarizing beam splitter (PBS). In other words, a differential light detector detects the difference of light intensity between polarized component passing through the PBS and polarized component reflected from the PBS to output reproduced data signal. Accordingly, since the conventional magnetooptical disk player detects a signal by S/N ratio, the improvement of the S/N ratio means the improvement of reproduction efficiency. As shown in FIG. 2, the magnetooptical disk player has light intensity noise of semiconductor, short noise of light detector caused by PN junction, and thermal noise of signal amplifier, which are problems to solve.
The light intensity noise of semiconductor laser has a close relation with an oscillate mode of laser. Thus, recently, a single mode semiconductor laser diode is driven by a high frequency signal of hundreds of MHz so as to operate the diode as a multimode diode which reduces the semiconductor laser noise. However, since the short noise of light detector is relatively greater than the thermal noise of signal amplifier, a finally output S/N value is greatly affected by the short noise.