An SRAM cell capable of enhancing the cell ratio and method of manufacturing the same are disclosed. The SRAM cell has pull-up devices, pull-down devices and access devices that interconnected at cell nodes, including : current reduction part for reducing current of the access devices, wherein the current reduction part is connected with the access devices and the cell nodes.

1. Field of the Invention
The present invention relates to a semiconductor memory device and method of manufacturing the same, and more particularly, to a static random access memory cell capable of enhancing the cell ratio and method of manufacturing the same.
2. Description of the Related Art
A semiconductor memory device is classified into a dynamic random access memory (DRAM) and a static random access memory (SRAM) according to its memorizing method. SRAM is particularly significant due to its high speed, low power consumption, and simple operation. In addition, unlike the DRAM, the SRAM has advantages of straight forward design as well as not having to regularly refresh stored data.
In general, SRAM cell includes two driving transistors which are the pull-down devices; two access devices; and two pull-up devices. The SRAM cell is further classified as a full CMOS cell, a high road resistor (HRL), or thin film transistor (TFT) cell according to the type of the pull-up devices used.
The full CMOS cell utilizes a P-channel bulk MOSFET as the pull-up device. The HRL cell utilizes a polysilicon having a high resistance value as the pull-up device, and The TFT cell utilizes P-channel polysilicon TFT as the pull-up device. Of the above-mentioned structures, the SRAM cell with the full CMOS cell structure has optimal operational device properties and can be fabricated with a simple process. It, however, has both NMOS and PMOS transistors in the unit cell, resulting in a large cell size. Therefore, it is applied to memory devices having a small capacitance. On the other hand, SRAM cells with the HRL cell and the TFT cell structures have relatively poor performance and is complicated in their fabrication. Because of their small cell size, however they are generally applied to semiconductor memory devices in cases of larger capacitance.
FIG. 1 is a conventional circuit diagram of an SRAM cell with full CMOS cell structure.
As shown in this diagram , sources of PMOS transistors Q1 and Q2 for use in pull-up devices are connected to VDD. Drains of the PMOS transistors Q1 and Q2 are respectively connected in series to drains of NMOS transistors Q3 and Q4 for use in pull-down devices at cell nodes N1 and N2. Sources of the NMOS transistors Q3 and Q4 are connected to VSS. Gates of the PMOS transistors Q1 and Q2 are respectively connected to gates of the NMOS transistors Q3 and Q4, and these connection points thereof are respectively cross-coupled with the cell nodes N1, N2. In NMOS transistors Q5 and Q6 for use in access devices, gates are connected to a word line W/L, sources are respectively connected to bit lines B/L1 and B/L2. Drains of NMOS transistors Q5 and Q6 are respectively connected to the drains of the NMOS transistors Q3 and Q4 at the cell nodes N1, N2.
In the above described SRAM cell, the NMOS transistors Q5 and Q6 are turned on by turning on the word line W/L, to store data in a HIGH state in the node N1 and data in a LOW state in the node N2. Data in a HIGH state is inputted to the bit line B/L1 and data in a LOW state is inputted to the bit line B/L2, so that the PMOS transistor Q1 and NMOS transistor Q4 are turned on, and PMOS transistor Q2 and NMOS transistor Q3 are turned off. Therefore, the node N1 becomes a HIGH state and the cell node N2 becomes a LOW state. Furthermore, although the word line W/L is turned off, the cell node N2 is latched to maintain a LOW state and the cell node N1 is maintained at a HIGH state. Accordingly, data is stored in the cell nodes N1 and N2 respectively.
FIG. 2 is a plan view of the SRAM cell illustrated in FIG. 1. Referring to FIG. 2 with cross reference to FIG.1, A1 and A2 are the active regions of the PMOS transistors Q1 and Q2 for use in pull-up devices, B1 and B2 are the active regions of the NMOS transistors Q3 and Q4 for use in pull-down devices and the NMOS transistors Q5 and Q6 for use in access devices. C1 to C6 are the contact regions. Here, C1 and C2 denote contact regions of cell nodes N1 and N2. C3 and C4 denote contact regions of sources of the NMOS transistors Q5 and Q6. C5 denotes contact regions of sources of the PMOS transistors Q1 and Q2, and C6 denotes contact regions of sources of the NMOS transistors Q3 and Q4. There are also provided word lines 34a, 34b, and 54.
Meanwhile, FIG. 3 is a sectional view of the active region B1 taken along line III-III' of FIG. 2, and illustrates the sectional structure of the NMOS transistor Q3 for use in pull-down devices and the NMOS transistor Q5 for use in access devices.
As illustrated in FIG. 3, the NMOS transistor Q3 for use in pull-down devices and the NMOS transistor Q5 for use in access devices include : a semiconductor substrate 1 having an active region B1 of the NMOS transistor Q3 for use in pull-down devices and the NMOS transistor Q5 for use in access devices defined by a field oxide layer 2; a gate oxide layer 3 formed on the substrate 1 between the field oxide layer 2 and gates 34a and 54; source regions 5a, 5c and a common drain region 5b formed in the active region B1 both sides of the gates 34a and 54; an intermediate insulating layer 6 formed on the overall surface of the substrate and having contact holes which expose predetermined portions of the source regions 5a, 5c and the drain region 5b; metal-interconnection layers 7a, 7b and 7c connected with the source regions 5a, 5c and the drain region 5b through the contact holes.
Meanwhile, one of the factors determining the characteristics of the SRAM is the current driving capability ratio of the pull-down device, which is the quotient of the current amount of the driving device divided by the current amount of the access device(I.sub.DSAT DRIVER TRANSISTOR /I.sub.DSAT ACCESS TRANSISTOR), otherwise known as cell ratio. A higher cell ratio results in improved performance of the SRAM. Therefore when the current amount of the pull-down device is large and the current amount access device is small, the performance of the SRAM cell is improved.
An operation of the SRAM related to the cell ratio is as follows. In case that the data in a low state is stored in the node N1 and the data in a high state is stored in the cell node N2, the voltage of the cell node N1 is determined by the current amount ratio of the NMOS transistors Q5 and Q6 for use in access devices and the NMOS transistors Q3 and Q4 for use in pull down devices. Accordingly, the node N1 is intended to maintain the low voltage with the increase of the current amount of the NMOS transistors Q3 and Q4, and with the decrease of the current amount of the NMOS transistors Q5 and Q6. If so, the voltage of the cell node N1 is not drastically changed from the low state when the NMOS transistors Q5 and Q6 are turned on during the reading operation, even though the voltage of the bit line B/L1 is changed. In case the voltage variation of the cell node N1 is small, the voltage of the cross-coupled cell node N2 is still maintained in the high state.
Therefore, conventionally, the cell ratio is controlled in a manner wherein the width of the NMOS transistor for use in access devices is reduced and its length is increased thereby increasing its current amount, and the width of the NMOS transistor for use in pull-down devices is increased and its length is reduced to thereby reduce its current amount. The width and length of the transistor, however, cannot be reduced below a predetermined level, and therefore there is a restriction in reducing the size of the cell to enhance the cell ratio.

Hyundai Electronics Industries Co., Ltd.


Foldable tent frame for coupling a tent cloth with the tent frame in an integral form is disclosed. Each of the foldable tent frame members for tension-supporting the tent cloth from all sides includes a plurality of rods each having protuberances on both ends thereof with an elliptical flat spring coupled with it, hinged straight joints each having a securing sleeve, and a hinged bent joint, so that the tent can be folded into a compact size so as to make it convenient to carry and store, and that the tent can be set up into a firm large tent in a simple manner by unfolding the frame. Further, the structure of the frame is simple, and the materials constituting the frame are strong. Further, the replacement of the components is easy, and the sleeve has holes for discharging foreign materials such as sands. Thus the tent is ensured of a convenience of use and structural safety.

1. Field of the Invention
The present invention relates to a foldable tent frame for coupling a tent cloth with the tent frame in an integral form. In particular, the present invention relates to a foldable tent frame for tension-supporting the tent cloth from all sides, which includes a plurality of rods each having protuberances on both ends thereof with an elliptical flat spring coupled with it, hinged straight joints each having a securing sleeve, and a hinged bent joint, so that the tent can be folded into a compact size so as to make it convenient to carry and store, and that the tent can be unfolded into a firm large tent in a simple manner by unfolding the frame.
2. Description of the Prior Art
A typical conventional tent is disclosed in French Patent 2,422,777 and British Patent 2136845A, and this conventional tent has a plurality of frame members which are inserted into connecting devices, so that the tent can be installed to the desired height.
The tent of this type is economically advantageous. However, when the tent is disassembled, the separated frame members are liable to be lost, while when the tent is installed, all the joints of the frame members have to be assembled one by one. Consequently, time and efforts are much expended, and a severe inconvenience is encountered.
In an attempt to overcome the above disadvantages, another tent is disclosed in U.S. Pat. No. 4,074,682, and in this tent, the frame members are connected in the form of hinges.
In this conventional tent, there is no apprehension that the frame members are lost, and the tent can be speedily installed compared with the tent using the connecting devices.
In this tent however, its fixing posture is not secure. That is, if the tent receives a biased pressure by wind, the hinges of the frame members can be folded inwardly, with the result that the frame member may fall down. Thus there is a problem in the postural stability.
There is still another tent which is disclosed in U.S. Pat. No. 1,846,496. In this conventional tent, in order to more securely fix the hinge portion of the frame member, a sleeve is fitted to a hinge portion across two joining segments, and a fixing rod is fitted to it. Further, a lever having a ratchet on the sleeve is installed by means of a spring.
The structure of this tent is very complicated, and therefore, the production cost is raised. Further, the frame can be unfolded in a state with the lever pressed, and therefore, the unfolding manipulation is inconvenient. Further, during the use of the tent, the user may be injured, or the tent cloth or the user's cloth may be damaged.
Particularly, the upper folding portion of a frame member consists of a simple hinge, and therefore, its strength for supporting the ceiling of the tent is weak. Further, a separate securing device should be disposed at the crest portion for maintaining the frame members in the horizontal posture, thereby further making the frame structure complicated.
In an attempt to overcome the above described disadvantages of the foldable tent, there is disclosed still another tent in Korean Utility Model 39753 and U.S. Pat. No. 4,750,509 which were granted to the present applicant. In this conventional tent, a ratchet is installed on a hinge portion between frame member segments by means of a spring. Thus, if the frame members are unfolded, the ratchet is automatically engaged with an engaging piece of the frame member, thereby fixing the frame member in a straight form.
This tent ensures a folding convenience and a postural stability. Once the tent is installed, the frame members are not bent against a wind pressure, and the tent can never be collapsed. Particularly, the upper segment of a frame member forms a certain angle relative to the lower segment of the frame member owing to a bending of a connecting tube of the hinge. Therefore, the roof of the tent is firmly supported, and therefore, a separate device is not disposed on the crest portion of the tent.
However, the spring of the hinge portion is exposed, and therefore, it is aesthetically undesirable. Further, the bottom parts of the frame members support the tent cloth by being inserted into bands which are sewed to the tent cloth like in the previous methods. Therefore, the frame members are easily separated from the tent cloth during the folding of the tent, this being a problem.
In the above described conventional tents, the structure of the hinge portion is complicated, and therefore, the commodity value is degraded. Further, human fingers are liable to be caught into the gap of the spring of the ratchet, and the upper bent portions of the frame members are weak, with the result that the tent supporting strength is weak. Further, the bottom parts of the frame members are inserted into the bands which are sewed to the tent cloth, and therefore, if the tent is oscillated, the frame members are liable to depart from the bands.
Further, in the conventional foldable tents, the segments of the frame members are joined either by providing a joint and a rod in each of them through an injection molding, or are joined by means of pins. Therefore, during a repair or replacement of a frame member, the total frame has to be replaced together, and therefore, losses in time and economy are significant. Further, the conventional foldable tents use elastic frame members so as to form dome shaped tents, and therefore, the frame members are too weak to support a large sized tent such as a family cabin tent or sun shelter or screen shelter.

Foldable tent frame for coupling tent cloth with tent frame in integral form


In a linear ion trap in which an essentially quadrupole RF electrical field is generated between at least four rod-shaped electrodes, ions may be mass-selectively ejected orthogonally to the axis. An aspect of the invention comprises compensating for field irregularities along the axis of a linear ion trap, which result, at different ejection locations, in the ejection of ions of the same masses at slightly different times, by of measuring the ions that are ejected at the different ejection locations using a number of separate detectors, and correcting, after a mass calibration of each of the mass spectra, the time shifts of the various location-dependent mass spectra during their addition to a combined spectrum.

Linear ion traps are described in U.S. Pat. No. 5,420,425 to Bier et al. A particularly preferred embodiment, which is in fact applied in a successful commercial mass spectrometer, consists in assembling four hyperbolically shaped rods to create a very precise linear quadrupole system, making slots in two opposing rods, and mass-selectively ejecting the gas-cooled ions through the slots by radial resonant excitation. If the arrangement is perfectly symmetrical, the ions then emerge, during what is called a mass scan, uniformly (although in offset ion pulses, on account of the resonantly excited vibrations of the ion cloud) through the two slots in the opposing pole rods throughout the individual ion mass signals, and are measured by two flat detectors placed in front of the two slots. An ion trap of this type is shown schematically in FIG. 1, although only one of the detectors is visible.
In order to record a mass spectrum, a mass scan is required in which the operating parameters of the ion trap are changed in such a way that ions are ejected mass-selectively and mass-sequentially out of the ion trap and into the detectors where they are measured. "Mass" refers here, as is always the case in mass spectrometry, to the mass-to-charge ratio, m/z. The specialist knows several types of such mass scans, including, in particular, ejection by storage instability at the edge of the Mathieu stability diagram, and ejection of the ions by radial, resonant excitation by a dipolar RF excitation voltage. In the latter case, the resonant ejection can be supported by nonlinear resonances; this then permits particularly fast scan methods with high mass resolution, as described in U.S. Pat. No. 6,831,275. Ejection by nonlinear resonances also offers the advantage that the ions can be ejected on one side only, so that only one detector is required.
An advantage of linear ion traps over so-called three-dimensional ion traps, which consist of a ring electrode and two end cap electrodes, is that they are easier to fill and have a high capacity for ions. A disadvantage of this arrangement is the extraordinarily high precision necessary to give a constant form and intensity to the RF electrical field at every cross-section along the axis. The precision of the RF field is affected by disturbing effects at both ends of the pole rod system, disturbances at the ends of the slots, and, in particular, by the mechanical precision required for the shape and spacing of the pole rods.
Pole rods are usually used with an internal spacing of eight millimeters, that is to say an "inside radius" of four millimeters. If, at any point along the axis, this radius deviates from its specified value by as little as two micrometers, then ions with a mass of 2001 Daltons (or 1999 Daltons) are ejected instead of the desired 2000 Daltons. If ions with a mass of 1000 Daltons are to be ejected, then ions with a mass of 1000.5 Daltons (or 999.5 Daltons) are ejected at the location of the inaccuracy. This means that a mass spectrometer of this type does not offer usable resolution if it has such dimensional inaccuracies. The usable mass range is also limited, as a resolution of a single mass unit is no longer available above 2000 Daltons. In fact the mechanical precision required for the pole rods of a usable mass spectrometer is much less than a micrometer.
The requirement for a mechanical precision of well below one micrometer is, however, almost impossible to meet. Commercial mass spectrometers of this type are restricted to a mass range of 2000 Daltons, with a maximum resolution at the upper end of the mass range of about R equal to 4000, whereas commercial three-dimensional ion traps consisting of turned parts offer a mass range of 3000 Daltons along with a mass resolution of more than R equal to 10,000 at the upper end of the mass range. This difference is crucial for many applications, such as modern protein analysis.

Linear RF ion trap with high mass resolution


A object of the present invention is to provide an objective lens that two non spherical surfaces are combined and a numeral aperture is more than 0.7, and to provide an optical pick-up apparatus which can be used for an optical recording medium having high information recording density by using this objective lens.. There is disclosed that a first surface is a rotating ellipse surface (a cone constant k: -1.ltoreq.k<0), and curvature of the first surface, glass materials (refractive index) of a first lens 1 and a main plane interval d of the total of combination of two lenses are properly established to satisfy the fixed relational expression.

1. Field of the Invention
The present invention belongs to a mechanical field relating to an objective lens and a recording/reproducing apparatus for recording/reproducing an information signal to an optical recording medium such as an optical disc having the objective lens.
2. Description of the Related Art
Conventionally, an optical recording medium such as an optical disc is widely used due to mass-production and low cost for reserving data such as moving picture information, voice information, data for a computer. Recently, high density and large capacity is requested more and more because an information-oriented society is sharply progressing.
In order to improve recording density of the optical recording medium, both of a short wavelength of a flux of light for reading out an information signal and a high numeral aperture of an objective lens (using the objective lens having the high numeral aperture) for collecting the flux of light on the respective optical recording medium are effective.
The NA of the objective lens for so-called "a compact disc (CD)" (a digital optical disc for an audio signal or computer data) is 0.45, on one hand, the NA of the objective lens for so-called "a digital video disc (DVD)" (a digital optical disc for a video signal) the recording density of which is improved rather than "the compact disc" is 0.6.
The objective lens for these optical disc is formed as a non spherical single lens (a single ball non spherical lens) made of synthetic resin and glass materials.
"The digital video disc (DVD)" has a disc substrate which is 0.6 mm thick that is a half of the thickness of the disc substrate of "the compact disc" and an optical magnetic disc in order to reduce influence of comatic aberration due to a gradient of the disc.
In the oon spherical single lens having the numeral aperture (NA) higher than that used at present.
One of reasons is processing of metallic mold. That is to say, when the gradient of the surface of the lens is larger than 45 degrees as reference is vertical to an optical axis, it is hard to process the non spherical metallic mold due to a size of an end of a diamond cutting tool. Further, the sharper curvature is, the larger depth (called "sag") in the direction of the optical axis from the top of the lens to the outest circumference is, therefore, the cutting processing of the metallic mold is hard.
If the processing is possible, in an area that the numeral aperture (NA) is rather than 0.7 as an single lens, high degrees aberration correction higher than 7 degrees is essential. Further more free degrees of design are necessary for it. Though it is considered to make use of a higher degrees non spherical coefficient for correction it, it is hard to process and design, therefore, it is not an effective means.
Under these circumferences, though the non spherical lens the numeral aperture (NA) of which is more than 0.8 is reported as the design, there is no report that the lens the numeral aperture of which is larger than 0.7 is made as a single lens.
On the other hand, the lens having the high numeral aperture that the numeral aperture is larger than 0.7 used for a conventional microscope and so on is a combination lens including plural of spherical lenses for which plural kinds of glass materials are used. From an optical similarity between the microscope and an optical pick-up apparatus for the optical disc, it is easily considered to apply the same lens as that for the microscope for the optical lens of the respective pick-up lens. Further, at the dawn to make the optical lens practicable, the combination lenses including two groups of three spherical lenses were used.
However, these combination lenses are necessary to be precisely assembled, and unstable performance and high cost is inevitable.
This problem has been solved by the non spherical mold single lens. In the non spherical mold lens, not only it is possible to obtain the non spherical form having high precision, but also it is not necessary to assemble due to a single ball and it is possible to obtain sufficient tolerance to decentering and falling. However, in the non spherical mold single lens, as above mentioned, it is difficult to make the non spherical single lens having the numerical aperture (NA) higher than that used at present.

Objective lens and recording/reproducing apparatus


A storage system and method are provided. The storage system may be for storing fluids, and include a first storage tank having an internal first volume defined by one or more exterior sides of the first storage tank being designed to have a super elliptical shape circumscribed by a rectangle or square so that the internal first volume is greater than an internal volume of a storage tank designed to have an elliptical or circular shape circumscribed by the rectangle or the square. The circumscribing rectangle may be a golden rectangle.

1. Field
One or more embodiments include one or more storage tanks with at least one side being designed to have a super elliptical, one or more embodiments include one or more storage tanks in a chemical system that are designed to have at least one side be super elliptical shaped, one or more embodiments include storage tanks designed to have at least one side be super elliptical shaped in a redox flow battery system, and one or more embodiments of such a redox flow battery system that include one or more strings of storage tanks designed to store electrolyte and have at least one side be super elliptical shaped for increased storage efficiency and improved self-support.
2. Description of the Related Art
Large outdoor storage tanks are usually made of steel and mounted on concrete pads. Large indoor chemical storage tanks are often made of stainless steel or polypropylene and may be mounted on a concrete floor or be rack mounted. Most large storage tanks are in the shape of a vertically mounted cylinder having a horizontal cross-sectional area in the shape of a circle. It is generally of advantage to keep the height of the tank to a minimum in order to minimize the fluid pressures near the bottom of the storage tank. It is also generally of advantage to reduce the ground or floor area occupied by the storage tank to reduce the real estate costs, balanced with a height of the storage tank and desired volume of fluid being stored.
Buildings are generally rectangular in shape and therefore typically have floors that are laid out in rectilinear patterns. Outdoor real estate is also generally laid out in rectilinear plots of ground. To make maximum use of available floor space or outdoor real estate it would be most efficient to use storage tanks that have a square or rectangular cross-section. However, because of internal fluid pressures, the lateral (or vertical) sides of large square or rectangular storage tanks would typically bulge outwards unless the storage tank walls were made exceptionally thick and rigid. Storage tanks are therefore generally made to have a circular cross-section to minimize the material requirements, as a circle cross-section provides substantial self-support for the storage tank typically counteracting such internal fluid pressures.
A circular cross-section tank resting on a rectangular floor layout occupies a square area of floor space. Thus, the floor area between the circular tank area and the circumscribed square floor area represents wasted floor space. For a circle or an ellipse this represents 21.5% of wasted floor space. This wasted space could be partly recovered by using a square (or rectangular) tank having rounded corners. Although this geometry would recover a significant portion of the wasted space between the circle and the square, it leaves the tank with long un-curved wall segments that must be reinforced to resist the internal fluid pressures.
The above discussion applies equally to circular cross-section tanks and their circumscribed squares, and to elliptical cross-section tanks and their circumscribed rectangles. Circles are a special case of the more general elliptical shape, so the discussions which follow will focus on elliptically shaped cross-section tanks, even though elliptical tanks are rather rare in tank designs.

Storage tanks using super ellipse geometries


Methods and systems for determining coil eccentricity of seismic sensors configured or designed for use in seismic signal detection. A direct electrical current is applied to a moving coil of a seismic sensor such that the moving coil is dislocated from a neutral position relative to the magnetic field in the seismic sensor. A predetermined indicator is measured and eccentricity of the coil (δ) relative to the center of the magnetic filed is determined using the predetermined indicator.

In the oil and gas industry seismic sensors are deployed at various locations, such as on the earth surface, in the sea, at the seabed, or in a borehole, to provide operationally significant subsurface structural and material information by measuring seismic signals reflected from changes in the subsurface structures. In this, seismic sensors are commonly used for purposes of obtaining useful data relating to acoustic impedance contrasts in subsurface structures.
In seismic signal detection, the vibrations in the earth resulting from a source of seismic energy are sensed at discrete locations by sensors, and the output of the sensors used to determine the structure of the underground formations. The source of seismic energy can be natural, such as earthquakes and other tectonic activity, subsidence, volcanic activity or the like, or man-made such as acoustic signals from surface or underground operations, or from deliberate operation of seismic sources at the surface or underground. For example, the sensed seismic signals may be direct signals that are derived from micro-seismicity induced by fracturing or reservoir collapse or alteration, or reflected signals that are derived from an artificial source of energy. Sensors fall into two main categories; hydrophones which sense the pressure field resulting from a seismic source, or geophones which sense vibration arising from a seismic source.
Typically, geophones are sensitive to vibrations of low or very low frequency. As depicted in FIG. 1B, a typical geophone 10 has one or more cylindrical moving coil 12 that is suspended by springs 20, 22 so as to be disposed around a magnet 15 having pole pieces 16, 18. The geophone 10 has a housing 24 and end caps 26. Each moving coil 12 is maintained at a neutral, rest position by the springs 20, 22, and is free to oscillate in a magnetic field of the magnet 15 from a centered position thereof. Springs 20, 22 are designed to maintain the coil 12 at a centered, equilibrium position relative to the magnetic field of the magnet 15. Note again FIG. 1B.
When the earth moves due to the seismic energy propagating either directly from the source or via an underground reflector, the geophone, which can be located at the earth's surface, in the sea or at the seabed, or on the wall of a borehole which penetrates the earth, moves with the particle motion caused by acoustic wave propagation. If the axis of the geophone is aligned with the direction of motion, however, the moving coil mounted on the spring inside the geophone stays in the same position causing relative motion of the coil with respect to the housing. When the coil moves in the magnetic field, a voltage is induced in the coil which can be output as a signal.
If the geophone is tilted, i.e., is moved away from the orientation that it is designed for, the moving coil is eccentered with respect to the magnetic field in the magnet. Note FIG. 1C. For example, as depicted in FIG. 1A, typically vertical geophones are used in land seismic survey operations. The spring to support the moving coil is pre-stressed to compensate for gravitational force so that the moving coil is centered in the geophone. However, the geophones are manually planted in the ground and may not be vertical. If such a geophone is tilted, the pre-stressed spring causes the moving coil to move in the upward direction relative to the neutral position of the coil in the vertical position of the geophone, as depicted in FIG. 1C. The neutral or rest position of the moving coil is designated in FIG. 1C as x0, and the displaced position due to tilt θ is designated as x. Eventually, if the amount of tilt is large, the moving coil hits an end cap of the geophone so that the geophone is no longer able to respond to the seismic vibrations.
Although FIG. 1A depicts exemplary land seismic with typical vertical geophones, it is also possible to use three-component geophones of the type discussed herein in connection with seabed and borehole seismic.
FIG. 1D illustrates graphically the relationships between tilt of a 10 Hz vertical geophone and the geophone response parameters So, Do, and fo using measured data. In this, as evident from FIG. 1D, if a vertical geophone is tilted from its vertical position the geophone response parameters So, Do, and fo change based on the amount of tilt.
In land seismic survey operations, seismic data are processed by assuming that all the geophones that are planted on the land surface are vertical. If seismic waves propagate in the upward direction, a tilted geophone will output signal that is altered due to tilt and reduced by an amount equal to cos(θ), where θ is measured from vertical—note FIG. 1C. As consequence, incorrect orientation of the geophones can cause misinterpretation of the formation properties, by changing the apparent amplitude of reflected waves.
In seabed seismic survey operations, an ocean bottom cable (OBC) is deployed from a boat to the seabed. Note FIGS. 2A and 2B. Seismic sensors are mounted on the side of the cable. After the cable is deployed in the sea, the orientation of the sensors may be horizontal, vertical or upside down. Gimbaled mountings may be used so that a sensor is always vertically oriented irrespective of how the sensor is deployed. Recently, three-component omni-tiltable geophones have been used in sensor packages with a tiltmeter or inclinometer. By knowing the orientation of the mounting of the three-component geophone, it is possible to rotate the axis of the seismic measurements. Ideally, a magnetometer may be employed to know the horizontal orientation of the sensor package so as to transpose the detected seismic signals in the physical earth coordinates to determine from which direction the seismic signals arrive at the seismic sensors.
In a borehole seismic survey, one or more geophone is deployed downhole in a borehole. Note FIGS. 3A and 3B. The trajectory of the borehole is usually known by independent measurement. If the length of the deploying cable is known, i.e., the along depth, it is possible to determine orientation and position of the downhole sensor package, i.e., azimuth, inclination, depth and horizontal departure from the well head. The information missing is the relative bearing of the sensor package. As used herein, "relative bearing" refers to the angle of sensor package orientation. The sensor package or sound is typically cylindrical and may rotate in the borehole, and the orientation of the two horizontal geophones will not be known. To identify the sensor orientation, it may be possible to deploy such downhole geophones with a gyroscope. Alternatively, a tiltmeter or inclinometer may be integrated with the downhole geophones to determine relative geophone bearing against the direction of gravity.
In addition to the issues discussed above, others arise during manufacturing and assembly of geophones. In this, during manufacture the geophone moving coil may not be properly centered around the magnetic field in the magnet. After assembly, it is not possible to see whether or not the moving coil is properly centered around the magnet so as to be at its desired neutral rest position.
Displacement of the moving coil from its neutral rest position during assembly of the geophone may lead to changes in the geophone response parameters and increase in harmonic distortion. The offset of the coil reduces the dynamic range of the geophone. In a worst case, the geophone moving coil may hit the top or the bottom of the housing and therefore not respond to seismic signals that are received by the geophone. In particular, a properly centered moving coil is highly important for low frequency geophones, such as seismometers, since the acceptable operating tilt range for such geophones is small, i.e., in the order of a few degrees. Such low frequency geophones or seismometers often use a built-in carpenter's level or eye bubble to guide installation of the devices; however, such eye bubble levels show only the tilt angle of the geophone or seismometer housing relative to gravity, but do not show the eccentricity of the moving coil without a built-in displacement sensor inside the geophone or seismometer.
As previously mentioned, in the past, gimbaled geophones have been employed to avoid tilt in the geophone. However, gimbaled geophones tend to be bulky and are more expensive due to the additional hardware that is required for the gimbaled structure. Geophones with tiltmeters and other tilt determining sensors are known in the art, but require additional hardware and are difficult to fit in the limited space that is typically available in seismic surveying operations. In addition, extra wiring is required for electrical connection. Since a geophone type device is a passive sensor, only a twisted wire cable is required to connect the geophone to a data acquisition system. Typically, in land, seabed, or borehole seismic acquisition operations many geophones are connected using multi-twisted pair cables. Extra wiring for built-in tilt sensors means that additional conductors must be added to the cables thereby increasing cable weight and cost, and the maintenance costs for the cables. In addition, larger connectors are required which poses a reliability issue. For seabed and borehole operations, any additional connectors or connections to the cable are perceived as unreliable due to a tendency to leak. Therefore, increased wiring is not a preferred approach in seismic operations.
For single seismic sensors having tilt accelerometers, the electronics may be located away from the sensors causing alignment errors between the seismic sensors and the tilt accelerometers. Such errors are difficult to control making the use of such configurations problematic.
Accordingly, it will be appreciated that there exists a desire to improve upon conventional methods and systems that use geophones in order to improve the accuracy of seismic measurements.
The limitations of conventional seismic sensor designs noted in the preceding are not intended to be exhaustive but rather are among many which may tend to reduce the effectiveness of previously known sensor mechanisms in field operation. The above should be sufficient, however, to demonstrate that sensor structures existing in the past will admit to worthwhile improvement.


Electrostatic clamping devices and methods for reducing contamination to a workpiece coupled to an electrostatic clamping device are disclosed. According to an embodiment an electrostatic clamping device for coupling a workpiece comprises: an embossment portion on a surface of a body to contact the workpiece; and at least two electrodes within the body; wherein the two electrodes are separated by a separation portion below the embossment portion.

1. Technical Field
The present disclosure relates generally to integrated circuit processing, and more particularly, to electrostatic clamping devices for coupling a workpiece and methods for reducing workpiece contamination in the coupling.
2. Related Art
Electrostatic chucks are widely used to support/hold wafers for processing, e,g., ion implantation, in integrated circuit (IC) processing systems. An electrostatic chuck includes a chuck body having at least one electrode within the chuck body. When a voltage is applied to the electrodes, an electrical field is created adjacent to a surface of the chuck body such that a wafer can be clamped to the surface to be retained. The surface may include embossment portions, referred to as mesas, to support the wafer and to reduce physical contact with the wafer.
In the clamping, the backside of the clamped wafer has a physical contact with the chuck surface, e.g., mesas, of the electrostatic chuck. This contact may result an particles that contaminate the wafer and may contaminate the processing chambers of the wafer, which are generally referred to as backside particles. The contaminating backside particles usually damage devices manufactured from the wafer and cause yield losses.

Electrostatic chuck with separated electrodes

Varian Semiconductor Equipment Associates, Inc.


A multimedia system and method that provides easy universal text searching for non-technical users, is disclosed. A configuration of the multimedia system and method of the present invention also facilitates content delivery through multiple, independent, simultaneous feeds from a single source to two or more different destinations without impairing audio and/or video and/or data stream quality.

A variety of laser-readable discs are played in conventional single-disc or multiple-disc loading trays in an office, home or university environment. Examples of laser-readable discs generally include a compact disc (CD), CD-ROM, digital versatile disc (DVD), DVD-Audio, DVD-Video, DVD-ROM, and the like.
The technology that allowed multiple-disc loading is a carousel mechanism capable of holding several CDs or DVDs, for example. However, a major shortcoming of the carousel mechanism required only one disc to be played at a time. In addition, the mechanical switching from one disc to another was slow.
These shortcomings were solved by storing the contents of the discs onto a computer hard drive in order to allow more flexible access to the contents and to facilitate faster disc selection. However, applications of the hard drive technology were not without its accompanying drawbacks.
In one application, for instance, an MPEG compression scheme is employed to reduce the size of the data files stored on hard drives for faster music selection, for example. However, this compression scheme results in an audible reduction in sound quality. Moreover, this application has no DVD capability.
In another application where an MPEG compression scheme is not employed, in order to improve poor sound quality, flexible access to the contents on the hard drive became problematic because of searching capability drawbacks. Here again, this application is not capable of handling DVDs.
Accordingly, there is an increasing need to be able to provide students, faculty, staff, professionals and any variety of users, with a multi-media system that allows, in part, content delivery via multiple, simultaneous, independent feeds from a single source without impairment of audio/video quality.

Multi-media system and method for simultaneously delivering multi-media data to multiple destinations


A semiconductor component having at least one first contact structure for feeding in and/or leading away charge carriers in relation to the semiconductor component, which first contact structure has at least one contact-making point for electrically conductively connecting the first contact structure to an external terminal, and which first contact structure has at least one first-order branching point proceeding from the contact-making point, at which first-order branching point at least one first-order subsequent conduction track branches off. Each first-order subsequent conduction track has at least one second-order branching point, at which second-order branching point at least one second-order subsequent conduction track branches off, and the electrical through-conduction resistance of each second-order subsequent conduction track is higher than the electrical through-conduction resistance of the first-order subsequent conduction track connected to said second-order subsequent conduction track via a common second-order branching point.

The invention relates to a semiconductor component comprising at least one first contact structure for feeding in and/or leading away charge carriers in relation to the semiconductor component.
Semiconductor components are used for diverse applications, in particular in the embodiment as a transistor or a diode. The invention relates to such semiconductor components which comprise at least one first contact structure for feeding in and/or leading away charge carriers in relation to the semiconductor component. The contact structure is typically embodied as a metallic contact structure.
In this case, the metallic contact structure typically makes contact with one or a plurality of semiconductor layers, in particular one or a plurality of doped regions of the semiconductor layers. For electrically connecting the semiconductor component to further components and/or an external circuit, the contact structure has at least one contact-making point. It is known to produce an electrically conductive connection via such a contact-making point for example by means of bonding, via cell connectors, hot tips or other contacting methods.
In order to feed charge carriers to the semiconductor component or lead them away therefrom areally, comb-like metallic contact structures are known. The latter have approximately the shape of a comb by virtue of the fact that the contact structure has a plurality of successive first-order branching points proceeding from a contact-making point, at which first-order branching points in each case at least one metallic subsequent conduction track (the "fingers" of the comb) branches off. Such structures are known for example in the case of power transistors or in the case of photovoltaic solar cells.
Due to the rising demand for electrical power, growing energy costs and increasing environmental awareness, there is a need for optimized, cost-effective, highly efficient and reliable semiconductor components. Particularly in the case of transistors, higher switching frequencies and the reduction of power losses are desirable. An increase in efficiency is always striven for correspondingly in the case of photovoltaic solar cells, for example.

Semiconductor component comprising at least one contact structure for feeding in and/or leading away charge carriers

Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V.


In a mobile communication system, a data communication fixed station 3 and a voice communication fixed station 4 control a common service area, the connection between a mobile station 5 and the data communication fixed station 3 can be quickened. The data communication fixed station 3 notifies, sequentially, the voice communication fixed station 4 of channel informations (e.g., usable channels, traffic quantity). The voice communication fixed station 4 receives the channel information via a broadcast channel for voice communication, and broadcasts the channel information to the mobile stations. When the mobile station 5 is to execute packet communication with an ISDN 1 via the data communication fixed station 3, the mobile station 5 selects an appropriate channel among the channels broadcasted thereto, and notifies the data communication fixed station 3 of the selected channel. As such, since the mobile station 5 can determine the channel before the actual communication between the mobile station 5 and the data communication fixed station 3 takes place, the connection between the mobile station 5 and the data communication fixed station 3 can be quickened.

Recently, it has been shown that a mobile communication system may include a plurality of systems for covering identical service areas. For example, a TDMA voice communication system for transmitting voice signals and a TDMA packet communication system for data communication may be provided for the identical service areas. If the plurality of systems are provided for the identical areas in the conventional mobile communication system, communication requests from the mobile stations are notified by the individual systems. Meanwhile, the mobile stations, which are provided with a plurality of receivers corresponding to the systems, receive communication requests from the systems individually, and enjoy communication services from the systems respectively.
As described above, if the mobile station in the conventional mobile communication system is to enjoy communication services from the plurality of systems, the mobile station may by provided with a plurality of receivers corresponding to the systems so as to receive communication requests from the systems, simultaneously. Such a situation is problematical by causing difficulty of miniaturization of the mobile station, and by causing enlargement of power consumption.
The problems described above may occur similarly concerning the level measuring channels utilized for the plurality of systems. The details are the following. A fixed station, in a mobile communication system coming under the minimum zone structure TDMA system, is generally provided with a level measuring channel having a constant transmission power in all slots. The mobile station measures reception field levels of a plurality of level measuring channels and visits the zone corresponding to the channel having the highest electrical field power level.
Incidentally, it is difficult to determine the zone to be visited by measuring electrical field power levels of ordinary traffic channels in place of the level measuring channel. The reason is that transmission power control for varying transmission power is executed, with respect to every mobile station (i.e., every TDMA slot), in order to reduce interference with other zones, so that the zone cannot be determined simply by the reception field levels of the traffic channels.
However, since the master and slave systems are provided with independent level measuring channels in the conventional technique, which causes difficulty such as miniaturization of the mobile station and enlargement of power consumption. Furthermore, communication quality is reduced due to increasing of interference for traffic channels in other zones, the channels having the same frequency of the level measuring channel.

Mobile communication systems sharing a control channel


An imaging lens includes first to sixth lens elements arranged from an object side to an image side in the given order. Through designs of surfaces of the lens elements and relevant lens parameters, a short system length of the imaging lens may be achieved while maintaining good optical performance.

In recent years, as use of portable electronic devices (e.g., mobile phones and digital cameras) becomes ubiquitous, much effort has been put into reducing dimensions of portable electronic devices. Moreover, as dimensions of charged coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) based optical sensors are reduced, dimensions of imaging lenses for use with the optical sensors must be correspondingly reduced without significantly compromising optical performance. However, the most important characteristics of imaging lenses are imaging quality and size.
U.S. Pat. No. 8,477,431 discloses a relatively long conventional imaging lens that includes six lens elements, where both of the object-side surface and the image-side surface of the third lens element have a concave portion in a vicinity of a periphery of the third lens element. This design easily leads to a substantially undersized/small field of view which makes it difficult to comply with increasingly stringent design requirements.
Reducing the system length of the imaging lens while maintaining satisfactory optical performance is always a goal in the industry.

Imaging lens, and electronic apparatus including the same


A drainage catheter for selective positioning within the human vasculature which includes a catheter body defining separate pressure and discharge lumens. A connector means at a proximal end of the catheter connects the pressure channel to a source of liquid under pressure. An inlet opening is positioned in the side of the catheter adjacent the distal end thereof and communicates with the discharge channel. The pressure channel extends from the proximal end distally forward of the inlet opening and then curves rearwardly to join the discharge channel at said inlet opening. The pressure channel is shaped to form a spray nozzle to direct pressurized fluid in the pressure channel across said inlet opening and into the discharge channel to create a suction adjacent the inlet opening. A preformed distal tip portion extends from the distal end of the drainage catheter. The preformed tip portion is formed of a material having the characteristic of retaining a plastic memory and is preformed into a curved configuration for selective positioning.

1. Field of the Invention
The present invention relates to a drainage catheter which may be inserted into a human vessel for removing blood clots, plaque and other such debris.
2. Description of the Prior Art
Prior art drainage catheters have included a pressure channel which extends along the length of the catheter and which forms a tongue at the distal end of the catheter, which in turn curves back to a discharge channel. A spray nozzle is formed at the tip of the tongue to deliver a liquid jet of fluid. For removing liquids or solid particles, the discharge channel may be connected to a suction pump, or alternatively may just empty into a collection reservoir. The jet of fluid which is delivered by the spray nozzle is used for breaking up, or crushing, solid particles and for removing the solid particles, or deposits, from the vessels of the body.
The present invention has for its object a drainage catheter system of the type described above which can be introduced into blood vessels and which may be selectively positioned to a desired location without damaging the vascular system. Specifically, the catheter of this invention may be used without the usual difficulty which is encountered in positioning the distal tip of the catheter associated with prior drainage catheter systems.


An ion analyzing apparatus for analyzing the composition of an object includes a chamber maintained under a vacuum, a support for supporting a plurality of objects disposed in the chamber, and a drive unit that selects one of the supported objects and rotates the selected object. An ion generator irradiates the rotating object with primary ions. A detector detects secondary ions emitted from the rotating object. An analyzer analyzes the secondary ions. A transfer device is connected to the supporter. The transfer device rotates the support or moves the support linearly in a horizontal direction to place an object at a predetermined position at which the object is selected and rotated by the drive unit.

1. Field of the Invention
The present invention relates to the analyzing of an object to determine a composition of a layer of the object. More particularly, the present invention relates to a method of and apparatus for analyzing ions in a layer of an object using secondary ion mass spectrometry.
2. Description of the Related Art
Semiconductor devices having a high degree of integration and which operate reliably at a high speed have been developed to process massive amounts of data in a short amount of time. In general, such highly integrated semiconductor devices are fabricated by performing various processes on a semiconductor substrate. These processes include, for example, a process of forming a layer on the substrate, an ion implantation process, an etching process, and a process for forming a wiring pattern on the substrate. Ultimately, though, the semiconductor devices must be analyzed to detect for processing failures or the like.
One apparatus for analyzing an object, such as a semiconductor device, is a secondary ion mass spectrometer (SIMS). The SIMS irradiates first ions having a kinetic energy of about 0.5 keV to about 20 keV onto a surface of the object such as a semiconductor device to break the bonds between the atoms or molecules of a material that makes up the surface of the object. The breaking of the bonds by the first ions is referred to as a sputtering. Thus, it can be said that the material is broken down into elementary particles by an elementary or a molecular unit by the sputtering. These particles are partially ionized to create secondary ions. The secondary ions are then supplied to an ion analyzer. The ion analyzer classifies the secondary ions according to their energy or mass to determine the composition of the material.
A SIMS may be used to perform a mass spectrum inspection, a depth profiling inspection, an ion imaging inspection and a quantification inspection of an object. The mass spectrum inspection determines the numbers of different types of secondary ions according to the ratio of the mass of each secondary ion to the electric charge of the secondary ion, to thereby provide a representation of the kinds of atoms in and composition of the surface of the object. The numbers of the secondary ions are counted at a rate of above about 1 count/sec. to about 109 counts/sec. Accordingly, the numbers of the secondary ions are provided on a logarithmic scale. Also, the masses of the secondary ions detected using the mass spectrum inspection method are about 1 atomic mass unit (amu) to about 300 amu. Accordingly, the mass spectrum inspection method can also be used to determine the molecules, particle clusters and isotopes making up the material of the object.
The depth profiling inspection discriminates particular ions from among the secondary ions. Intensity levels of the selected ions are measured over time to determine a distribution of the selected ions over the depth of the object.
The ion imaging inspection correlates the secondary ions to the positions at which they were generated, and measures the intensities of the secondary ions. For example, the ion imaging inspection scans the object with ions having a diameter of about 1 μm, and measure intensities of the secondary ions produced during the scan. The ion imaging inspection thus determines the distribution of the secondary ions across the surface of the object.
The quantification inspection simultaneously analyzes the object and a standard object under same conditions. The standard object is fabricated by an ion implantation process so that it has ions in a concentration and at a depth which are known. A comparison between the standard object and the object being analyzed is used to obtain the concentration and depth of particles making up the object under analysis.
When used to carry out the inspection methods described above, a SIMS has a good deal of sensitivity and a wide detection range. That is, a SIMS can be used to detect infinitesimally small particles in amounts of parts per million to parts per billion. Additionally, a SIMS can detect every element in the Periodic Table, and even the isotopes thereof.
In addition, a SIMS has the ability to perform a depth profiling of about 4 nm and a line scanning of about 200 nm. Accordingly, a SIMS is useful for detecting impurities in a semiconductor device. However, certain phenomena such as a surface effect, an interface effect, an electric charge effect, and a mass interference effect, can limit the effectiveness of the SIMS when applied to detecting impurities in a semiconductor device.
The surface effect is a phenomenon in which the profile of the surface due to first ions are implanted into the surface of the object and into contaminants on the surface of the object.
The profile of the surface displayed as a result differs from that actually exhibited by the surface. The interface effect is a phenomenon in which the locations of an interface in the object are inaccurately displayed due to a number of factors such as the surface roughness of the object, variations in the first ions, and contaminants.
The electric charge effect is a phenomenon in which charges accumulate on the surface of the object due to a collision of the first ions, and the generation of the secondary ions. The mass interference effect is a phenomenon in which a single atomic ion interferes with a molecular ion and a multiple charged ion.
It has thus been proposed to rotate the object during its analysis as a way to lessen the effects of the above-described phenomena on the inspection method carried out by a SIMS. When a rotating object is irradiated with the first ions, the sputtering rates of the atoms in the object vary so that minute impurities contained in the object can be detected. Accordingly, a composition of the object can be precisely analyzed.
FIG. 1 is a graph showing an analysis of a semiconductor device using a conventional analyzing method. FIG. 2 is a graph showing an analysis of a semiconductor device using a conventional rotation analyzing method in which the semiconductor device is rotated. The semiconductor device includes a silicon layer, a titanium layer formed on the silicon layer, and a gold layer formed on the titanium layer.
A surface of the semiconductor device was irradiated with primary ions. The primary ions etched the surface of the semiconductor device. Thus, the particles detected over time corresponded to the layers of the semiconductor device in a depth-wise direction of the semiconductor device, respectively. Particles of gold, titanium and silicon layer were detected over time, as shown in FIGS. 1 and 2.
However, the interfaces of the layers were detected imprecisely in the results of the method shown in FIG. 1. In particular, the gold layer was detected in a range A and the titanium layer was detected in a range B that overlapped range A to a great extent. Thus, the gold layer infiltrated the titanium layer. Also, the results showed that the titanium layer infiltrated the silicon layer.
On the contrary, in the method shown in FIG. 2, after about 900 seconds, that is a range A′, the gold layer was not detected. After about 1,100 seconds, that is in a range B′, the titanium layer was not detected. Thus, as these results show, the method of analyzing a rotating object can determine the composition of a semiconductor device with better accuracy than a method of analyzing the semiconductor device while it is stationary.
However, analyzing a plurality of objects using a conventional SIMS is difficult. When a single object having a diameter of about 80 mm is disposed on a stage in an ion chamber of the SIMS, it is relatively easy to rotate the object by rotating the stage about its center. However, it becomes more difficult to control the rotation of the stage the larger the stage becomes. Therefore, when a large number of objects are disposed on a stage in the chamber of the SIMS, rotating the objects is problematic because the stage must be large enough to accommodate all of the objects. Furthermore, the object under analysis on the rotating stage might not be accurately irradiated with the primary ions. As a result, although the object is analyzed while it is rotated, the accuracy of the analysis can be expected to be poor.
Furthermore, various conditions are created in the ion chamber to facilitate the analysis of an object. Therefore, when objects are placed one-by-one in the ion chamber and analyzed, the atmosphere within the ion analysis chamber must be checked and often adjusted each time. Accordingly, a large amount of time is required for analyzing the objects which adds which to the overall costs associated with the analyzing process.

Method and apparatus for analyzing the composition of an object


A self-repairing and self-sealing waterproof membrane, for insulating built structures subjected to hydrostatic pressure, includes a first layer of hermetic polymeric material, which covers a second layer of water-expanding polymeric material, in which additives of polymeric and/or mineral origin are added, arranged in contact with the concrete surface of the structure. The second layer includes a plurality of sublayers which are contiguous and have different expanding actions and mechanical characteristics. The membrane has substantially the shape of a continuous flat sheet, which gives the membrane the appearance of a uniform film, having a thickness between 0.2 and 5.0 mm and being composed of one or more of the following polymers: TPE, TPO, TPU, EVA, EPDM, EPM, HDPE, MDPE, LDPE, PE, PVC and other elastomeric or polymeric polymers, containing optional additions of fillers and other ingredients to give the article the necessary requirements of workability, mechanical strength, and durability.

Membranes of several kinds, adapted to insulate in theory the walls of a built structure in order to avoid water infiltrations are known in the construction sector.
Currently it is known to provide building structures by arranging mutually side by side a plurality of construction segments, usually made of reinforced concrete, which can be prefabricated and installed in place after their production, or obtained directly in place by means of concrete castings into appropriate formwork.
In order to stop water infiltrations which tend to rise from the ground in the interspace or channel defined between each pair of contiguous segments, it is known to spread between them appropriate resins, which once hardened constitute a barrier to such water infiltrations.
However, these resins suffer a drawback: once they have hardened, they in fact have a limited mechanical strength and are therefore often subject to breakage due to the mutual movements that occur between the segments that are connected to them and are due for example to the different thermal expansions to which said segments are subjected or to the settling movements of the ground.
Furthermore, since these resins can be used only if the two segments are very close to each other, they cannot be used to provide earthquake-resistant buildings; earthquake-resistance standards in fact, in order to avoid in case of an earthquake the phenomenon of hammering between two contiguous constructive segments, set high values for the minimum distance allowed between them, which therefore do not allow the use of these resins of the known type.
In the case of segments obtained directly in place, in order to limit water infiltrations it is also known to arrange, transversely to the interspace or channel defined between two contiguous segments, metallic sheets or strips of PVC (polyvinyl chloride) that have a generally approximately rectangular plan shape and are embedded, with their longitudinal ends, in the two segments at the time of their provision, so as to blend them and thus constitute a water infiltration barrier.
However, these sheets and strips of a known type suffer a drawback; in particular the metallic ones, but also the ones made of PVC, can in fact be deformed elastically only by a small extent and therefore are unable to follow the considerable dimensional variations of the channel defined between the two segments, which are due for example to the different thermal expansions thereof or to any movements of the ground; due to these dimensional variations, the sheets and strips can therefore crack and/or break easily, thus allowing the passage of water.
As a partial solution to this drawback, strips of plastic material are known the central region of which is tubular or bulb-shaped in order to facilitate the elastic deformations of said strip in the direction of the axis that joins the two segments; during the mutual movements of the two constructive segments blended by the strip, the central region of said strip can thus undergo elastic deformations even of a considerable extent and can therefore follow, without the danger of breaking, the dimensional variations of the channel defined between said segments.
Both this second type of strip and the ones described previously, however, suffer a drawback: for the purpose of fixing to the segments, which occurs in place during concrete casting, appropriate shapes are required the application of which is awkward and requires a long execution time.
Moreover, these solutions of a known type do not lend themselves to be used if the segments are prefabricated, since the strips cannot be fixed to them.
Moreover, in order to close completely the channel defined between two segments it is often necessary to mutually blend a plurality of strips arranged so as to be longitudinally aligned with each other; the connection between two contiguous strips occurs by mutually heat-sealing, for example by blowing air at high temperature or by means of an adapted heat-sealing plate, two transverse ends of the two strips, and this is awkward and dangerous and requires a long time and a certain skill on the part of the installation technician. Moreover, this heat-sealing cannot be performed in the presence of water in the channel defined between the two constructive segments.
Moreover, depending on the distance of the segments to be blended, on the pressure of the water to which they are subjected, and on the extent of the mutual movements provided for them, it may be necessary to use strips having different shapes and dimensions; it is therefore necessary to have a vast range of strips of different shapes and dimensions, and this has a negative effect on production, storage and transport costs thereof.
EP 0278419 is also known which discloses a waterproof membrane composed of a layer of clay, preferably bentonite, that is capable of swelling and is interposed between a layer of supporting felt and a covering layer preferably constituted by felt material.
All three layers are mutually assembled mechanically by tacking.
This membrane of a known type provides a waterproof sealing element in which both the supporting layer and the covering layer remain connected in a fixed manner during and after the expansion of the clay layer, so as to ensure a more compact packing of the expanded clay particles.
This known type of membrane, which is used mainly for sealing soils and landfills, is not devoid of drawbacks, which include the fact that in the case of reinforced concrete structures the layer of felt in contact with the concrete is unlikely to be saturated by the expanding material, allowing potential infiltrations of water that can occur between the concrete and the felt layer.
This drawback is observed in particular in the regions of overlap between two contiguous membranes, thus making said membrane completely ineffective.
US 20110197427A1 is also known which discloses a hermetic membrane which comprises a bather layer, a composite layer arranged on one side of the barrier layer, and a sealant, which is arranged in a mesh-like configuration between the composite layer and the barrier layer.
The composite layer is arranged directly in contact with the liquid concrete.
If a water leak through the barrier layer occurs, the sealant mesh should hinder or prevent the propagation of the infiltration to the contiguous surfaces, limiting the region affected by the damage and making it easy to locate and repair.
A first drawback that can be observed in the background art consists in the installation method of the hermetic membrane, which must be performed before the concrete castings so as to allow the liquid concrete to impregnate the composite layer; accordingly, this solution cannot be applied to already hardened concrete surfaces.
A second drawback that can be observed in the background art relates to the region of overlap of the sheets: in this region, the portion of the composite layer cannot be reached by the liquid concrete and therefore cannot be impregnated by it; a region of possible permeation of water, which would not be hindered in its propagation, is thus created.
A further drawback is due to the intermittence of the sealant layer, which does not ensure continuity in the sealing of the interface with the concrete, allowing again the propagation of water through the porosities of the concrete.
US20130022779A1 is also known which claims a sheet for use in the building sector for sealing holes, which comprises a flat sheet body that has at least one elastic sealing layer that is formed at least partially with a material that has sufficient elasticity and resilience, when the sealing layer is penetrated by a fixing element, to produce a sealing closure in an opening formed by the penetration of the fixing device.
Several alternatives are proposed for solving the problem of the insulation of walls against water infiltrations and multilayer systems are indicated in particular in which the body is a multilayer composite that has at least one membrane layer and at least one protective layer in addition to the sealing layer, or a layer of a closed-cell elastic foam, or a layer containing a viscoelastic gel, or microcapsules containing adhesives, or at least one adhesive, a sealant, a fluid resin and a material that expands when exposed to water or air, or a single- or two-component adhesive.
All these solutions are not ideal, since water can seep in any case due to the pressures involved.
This drawback can be observed more in overlap regions, which in order to avoid causing infiltrations must be sealed appropriately since they are not suitable for autonomous sealing.
Furthermore, in case of breakage of the membrane the infiltration might reach the concrete-membrane interface and allow the migration of the water along said membrane, thus spreading to the surrounding surfaces.
EP2151317B1 is also known which discloses a waterproof membrane, particularly for insulating built structures subjected to hydrostatic pressure, which comprises a first layer of water-expanding waterproof material that is adapted to cover the outer surface of at least one wall to be insulated of a built structure and a second layer of fibrous material that covers the first layer on the opposite side with respect to the wall to be insulated, and a plurality of filaments of the second layer that cross from side to side the first layer and can be embedded in the wall to be insulated from the mechanical grip of the first layer to the wall to be insulated.
This solution, also, suffers some small drawbacks, among which we note difficulty in achieving the mechanical coupling of the waterproof layer made of water-expanding rubber with a fibrous layer in which the filaments of said fibrous layer cross from side to side the waterproof rubber layer.
It has in fact been observed that water might diffuse through said filaments due to the expansion of the water-expanding rubber, which is unable/insufficient to stop the flow of water.
JP2003166179A is also known which discloses a membrane composed of a moisture-expanding sheet that comprises a nonwoven fabric, characterized by a draining structure, and a layer of bentonite in powder form.
This known art suffers the following drawbacks: the nonwoven fabric has a structure that is not waterproof and combination with bentonite, which is a natural clay, creates an expansion that is proportional to the absorption of water, which causes loss of the waterproofing capacity of the membrane as the expansion increases.
Moreover, in this membrane of the known type the components act separately, each for its own characteristics, without therefore cooperating to create a single amalgamation that is adapted to oppose the passage of water.
EP0606700 is also known which discloses a method for manufacturing a water barrier fabric that is composed of an upper mesh or sheet and a lower mesh or sheet, made of cardboard, glass fiber, fabric, waterproof polymeric sheet material, rope, mesh or other reinforcement, water barrier or stiffening material, which are identical or different and are incorporated within the water barrier fabric during manufacture in any desired combination.
In particular, an article can be manufactured that is composed of a central part made of material in powder or granular form, such as bentonite clay, which incorporates fibers and is arranged between the upper mesh or sheet and the lower mesh or sheet.
An article can also be manufactured which is instead composed of a material in powder or granular form, such as bentonite clay, which is arranged both above the upper sheet or mesh and in a central portion of the article, between the upper sheet or mesh and the lower sheet or mesh.
An article can also be manufactured which is instead composed of a material in powder or granular form, such as bentonite clay, which is incorporated within the lower half of the article and within a lower part of the central portion of the article between the lower mesh or sheet and the upper mesh or sheet.
In this article of a known type also the components act separately, each for its own characteristics, without therefore cooperating to create a single amalgamation that is adapted to oppose the passage of water.
Another drawback observed in this article resides in that the outer layer of fibers in the article or the external bentonite clay layer in the article, if it is in contact with the concrete, is unlikely to be saturated by the expanding material, allowing potential infiltrations of water that can occur between the concrete and the layer of fibers or bentonite.

Self-repairing and self-sealing waterproof membrane, for insulating built structures subjected to hydrostatic pressure


An apparatus and method for two-dimensional wavelength beam combining of a plurality of laser sources. In one embodiment, an external cavity multi-wavelength laser comprises an array of laser gain elements, two optical transform lenses, two dispersive elements, an imaging system, a deflective array, and an output coupler. First and second optical transform lenses spatially overlap optical beams in first and second dimensions forming regions of overlap at the first and second dispersive elements. The deflective array comprises a plurality of mirrors wherein each mirror deflects and rearranges the optical beams from a common row. The dispersive elements introduce wavelength discrimination that when combined with the output coupler, provide the required feedback gain. The output coupler creates a single output port for the plurality of external optical cavities established in unison with the plurality of laser emitters. The output coupler transmits a multi-wavelength output beam comprising spatially overlapped coaxial optical beams.

The present invention relates generally to the field of lasers and in particular to methods and apparatus for configuring two-dimensional multi-wavelength laser source arrays into composite coaxial beams having higher laser power.
Laser systems that use multiple laser sources or multiple laser gain medium, are utilized in a variety of applications including cutting, machining, welding, material processing, laser pumping, fiber optic communications, free-space communications, illumination, imaging and numerous medical procedures. Many of these applications can be significantly benefitted with higher laser power. In support of achieving higher laser power, the input energy is typically increased. However, simply increasing the input energy may introduce additional thermal management considerations. For example, thermal conditions and heat load within the laser gain medium typically contribute to internal aberrations and corresponding beam quality reductions in the emitted radiation. Additionally, unaddressed internal heating may also lead to internal damage of the laser components themselves. In general, issues like these place practical limits on the achievable laser power for a given laser system design approach. In many cases the most cost effective method for further power scaling is achieved by combining the optical outputs from more than one laser or laser gain medium.
The ability to focus a laser beam into a small spot is generally characterized by its beam quality which is in part, a measure of its usefulness in a many applications. Ideally, laser power scaling through beam combining of multiple laser sources or multiple laser gain medium would be done in a manner that minimizes the reduction in the beam quality of the combined beam. When considered in combination, both laser power and laser beam quality contribute to what is typically termed beam brightness. When either or both laser beam power and laser beam quality are improved, the brightness of the laser beam is said to be improved. Beam brightness, being a measure of the combination of the power and focusability of a laser beam, is a fundamental measure of a laser beam's overall utility in many high power applications.
Historically, many methods have been used to advance the above objectives with varying degrees of success. These methods can be organized into three broad categories of design approaches, namely coherent, incoherent and polarization approaches. Methods characterized by coherent approaches have the ability to power scale significantly but require a high degree of mutual coherence between the laser sources. They generally employ real time beam phasing techniques between the laser sources or laser gain medium that are complex and costly to implement. Polarization approaches are simple to implement but, by themselves, do not scale beyond a factor of two, one for each available polarization. There are many approaches that do not use either mutual coherence or polarization to combine beams. These fall within the category of incoherent approaches. In general, incoherent approaches are easier to implement then coherent approaches.
One of the simplest incoherent approaches employs side-by-side beam combining whereby the laser sources or laser gain medium are arranged side-by-side, propagate nominally parallel to one another, are not overlapping or coaxial, and are not phased to each other. This incoherent side-by-side combined beam can be focused but does not produce an optimal focused spot for the given diameter of the side-by-side combined beam. In this case, the beam quality is said to be reduced. Incoherent approaches that both power scale and also maintain good beam quality generally employ specified and unique wavelengths for each laser source or laser gain medium as a fundamental aspect in the combining process. This technique is often called wavelength or spectral beam combining. Examples of components often employed in these systems are dispersive prisms, dialectic wavelength filters, volume Bragg gratings, and diffraction gratings. Naturally, this approach leads to combined beams having many wavelengths, or put another way, a large laser linewidth. In some laser applications, having a large laser linewidth may not be a desirable feature, but for many other laser applications, a large laser linewidth may be inconsequential and may even be advantageous in still other laser applications.
Within the prior art, two dispersive methods of wavelength beam combining employing angular dispersion have been disclosed that achieve the challenging task of combining two-dimensional laser emitter arrays while maintaining beam quality. In both of these dispersive methods, a plurality of wavelength dependent dispersive elements are used sequentially in two essentially orthogonal directions to combine the two-dimensional array of beams into a single composite beam. In the first method, the orthogonal dispersive elements include a first-order diffraction grating or prism and an Echelle diffraction grating operating in several high diffracting orders simultaneously. In a second method, the orthogonal dispersive elements include a first-order diffraction grating or prism and a first-order diffraction grating stack made up of a plurality of individual first-order diffraction gratings each having a different amount of angular dispersion. An example of a two-dimensional wavelength beam combining system that includes the use of high-order Echelle gratings is disclosed in U.S. Pat. No. 6,327,292 to Sanchez-Rubio et al. filed on Jun. 21, 1999. Two different examples of two-dimensional wavelength beam combining systems employing the use of a first-order diffraction grating stack are disclosed in U.S. Pat. No. 8,179,594 to Tidwell et al. filed on Jun. 30, 2008 and U.S. Patent Application No. US 2011/0222574 A1 to Chann et al. filed on Mar. 9, 2010.

Two-dimensional laser system employing two dispersive elements


Proposed is a flame-retardant heat-curable flowable epoxy resin composition suitable for use in case potting of film capacitors exhibiting very little settling of the particulate ingredients in storage and excellent impregnability in case potting as well as excellent flame retardancy, moisture resistance and tracking resistance of the composition after curing. The composition comprises, as a uniform blend:. (a) 100 parts by weight of a bisphenol-based epoxy resin which is liquid at a temperature of working in case potting; PA1 (b) from 10 to 40 parts by weight of an alkyleneglycol diglycidyl ether or cycloalkyleneglycol diglycidyl ether; PA1 (c) from 80 to 120 parts by weight of a polycarboxylic acid anhydride; PA1 (d) from 4 to 20 parts by weight of a powder of red phosphorus; and PA1 (e) from 100 to 200 parts by weight of a powder of hydrated alumina which characteristically is a combination of (e1) from 80 to 95% by weight of a first powder of hydrated alumina having an average particle diameter in the range from 10 to 25 .mu.m and (e2) from 20 to 5% by weight of a second powder of hydrated alumina having an average particle diameter not exceeding 2 .mu.m.

The present invention relates to a novel epoxy resin composition or, more particularly, to a heat-curable flame-retardant epoxy resin composition suitable for case potting of film capacitors.
It is an established technology that a film capacitor roll encased in a plastic casing is impregnated with a heat-curable flowable resin composition such as an epoxy resin-based composition followed by heating to effect curing of the resin composition so as to complete a film capacitor with the plastic casing to serve as a protective envelope while it is important that the heat-curable resin composition is flame retardant as highly as possible as an inherent requirement for electric parts.
One of flame-retardant epoxy resin compositions of a typical formulation in the prior art and suitable for such an application comprises an epoxy resin, polycarboxylic acid anhydride as the curing agent, red phosphorus powder and powder of hydrated alumina as is disclosed in Japanese Patent Kokai 54-93044, 59-98123, 62-27420, 64-29463 and elsewhere. It is taught in Japanese Patent Kokai 60-115620, 61-176626, 61-276816, 62-7720 and 1-198658 and in Japanese Patent Publication 5-19806 that a flowable epoxy resin composition used for impregnation and encapsulation of various kinds of electronic parts such as flyback transformers, coils, capacitors and diodes can be imparted with improved impregnability and decrease in sedimentation or separation of particulate ingredients during storage of the liquid composition when the powder of hydrated alumina contained therein has a specific particle size distribution.
The above described improvement relative to the impregnating behavior and settling of the particulate ingredients such as hydrated alumina powders accomplished in the prior art epoxy resin compositions is still not very satisfactory for a flame-retardant epoxy resin-based composition used for case potting of film capacitors because the epoxy resin composition for case potting of film capacitors is required to exhibit, in addition to the requirement for complete absence of settling of particulate ingredients, excellent behavior of impregnation not only to completely spread over the surface of the capacitor roll but also to completely and uniformly fill up any smallest interstices such as the interlayer spaces of the film layers and voids in the plastic casing to the very corners.

Flame-retardant epoxy resin composition for case potting of film capacitors


A belt splicer (80) for butt-welding conveyor belts with longitudinal walls and methods for splicing belts. The belt splicer (82, 83) has bridges supporting belt clamps (88) above clamp jaws (12, 13). The bridges are attached at opposite ends to the corresponding jaws. Slots (96) along intermediate spans of the bridges allow the belt clamps to be adjustable positioned along the bridges. Adjacent belt clamps can be positioned with a space between them to accommodate the walls.

The invention relates generally to splicing tools for thermally joining the butt ends of plastic conveyor belts and, more particularly, to splicing tools that have position-adjustable clamps for firmly holding conveyor belts having longitudinal walls in place during splicing.
Splicing presses are used to weld the butt ends of two thermoplastic conveyor belt sections together. Conventional presses include a pair of clamps, each of which holds one of the two belt sections. The clamps, which extend across the entire width of the belt sections, firmly hold the sections with the butt ends facing each other across a gap. A heating wand is moved into the gap, and the two clamps close until the butt ends of the belt sections contact opposite sides of the heating wand. As soon as the butt ends are softened or melted sufficiently by the wand's heat, the clamps are retracted so that the wand may be removed. Then the clamps are moved toward each other until the softened or melted butt ends meet. The clamps hold the butt ends together as the joint at their interface cools.
Although splicing presses as described work well with belts that have a flat outer surface, they do not work well with belts having vertical walls, such as corrugated sidewalls, that extend along the length of the belt.

Bridge splicer and method of splicing conveyor belts


An apparatus and method are disclosed for converting XML data to a destination encoding format. A receive module receives a request for bytes of XML data in a destination encoding format streamed from a source XML file. A transfer module transfers the requested bytes from a byte conversion buffer to a request buffer in response to the request and the byte conversion buffer having at least the requested bytes. A conversion module, in response to the byte conversion buffer lacking the requested quantity of bytes, transfers part of the requested bytes to the request buffer, fetches input bytes from an XML file, stores the bytes in a receive buffer, transfers the input bytes through a byte-to-character converter to a character conversion buffer, transfers the characters through a character-to-byte converter to the byte conversion buffer, and transfers enough bytes to the request buffer to satisfy the request.

1. Field of the Invention
This invention relates to Extended Markup Language ("XML") data conversion and more particularly relates to XML data conversion from one encoding format to another while streaming a portion of an XML data file.
2. Description of the Related Art
The default encoding for an XML document is the 8-bit Unicode Transformation Format ("UTF-8"). Nevertheless, XML data can use various kinds of encoding representations. In particular, while an XML document can be stored in UTF-8 encoding in a remote database, it can also be saved in a region specific encoding on a local file system. Transferring an XML document encoded in UTF-8 from a remote database to a local file system in a region-specific encoding format requires conversion of the XML document from one encoding to another.
Encoding conversion utilities, also known as transcoders, may be used to facilitate the conversion process. However, typical transcoders require an XML document to be completely available before conversion begins. This may not be a problem when an XML document is relatively small in size. In such case, an entire XML document can be transferred from the remote database and then converted into the region specific encoding on the local system. Problems arise when the XML document is large in size and the local system is constrained in memory, bandwidth, and/or storage resources. Transferring large XML documents from a remote database may cause the local system to run out of memory. Advanced databases provide streaming materialization of large XML documents allowing data to be requested on an as-needed basis. This helps local systems avoid being bombarded with a large amount of data. Unfortunately, typical transcoders do not provide necessary interoperability with streaming materialization from databases.
Conversion using Java causes other problems. One issue is that in Java there is no support for direct conversion between any two arbitrary encoding representations. An intermediate character representation is necessary to convert from one encoding representation to another. For example, an XML document in UTF-8 encoding must first be converted into a character representation, which then can be converted into a region specific encoding format.
From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method for converting streamed XML data, representing only a portion of an XML document, from one encoding format to another using Java. Beneficially, such an apparatus, system, and method would be request driven and would use available Java converters.

Apparatus, system, and method for incremental encoding conversion of XML data using Java

International Business Machines Corporation


A solid-state image sensor includes a plurality of light-receiving elements arranged in a light-receiving area, and a plurality of micro-lenses corresponding to the light-receiving elements, and has a flattening film formed on the plurality of the micro-lenses. At a center of the light-receiving area, the micro-lenses are placed in positions directly above corresponding photodiodes, and placed in positions which are progressively offset from positions directly above the corresponding photodiodes, towards a center of the light receiving area, as micro-lenses are located farther from the center of the light-receiving area.

(1) Field of the Invention
The present invention relates to a solid-state image sensor including micro-lenses for a plurality of light-receiving elements formed on a semiconductor substrate, and a manufacturing method thereof.
(2) Description of the Related Art
In recent years, miniaturization of cameras is progressing along with increase in pixel count of solid-state image sensors.
With digital still cameras and camera-equipped mobile phones, a shortening of an exit pupil distance is progressing following the miniaturization of cameras. At this point, exit pupil refers to a virtual image of a lens (or stop) as seen from a light-receiving area, and exit pupil distance refers to a distance between the light-receiving area and a lens (refer to FIG. 18).
FIG. 18 illustrates a cross-section diagram of a camera portion of a mobile phone. A lens 110 is installed on a frame 111 of the mobile phone, and a CCD image sensor 112 is provided in an interior of the mobile phone. A distance between the lens 110 and the CCD image sensor 112 is an exit pupil distance D. Although incidence of light around a center of the light-receiving area is perpendicular, a periphery of the light-receiving area is limited to incidence of, not perpendicular, but oblique light.
FIG. 1 is a cross-section diagram illustrating a physical relationship of light-receiving elements and micro-lenses in an existing solid-state image sensor for facilitating shortening of an exit pupil distance. Light rays from a light source in the diagram represent incident light from a lens. The left side of the diagram represents a cross-section of a central portion of valid pixels making up a light-receiving area, and the right side represents a cross section of a peripheral portion of valid pixels making up the light-receiving area. As shown on the left side of the diagram, an in-layer lens 3, a color filter 5, and a micro-lens 7 are formed directly above a light-receiving element 1, in a central portion of the light-receiving area. Whereas in a peripheral portion of the light-receiving area, the in-layer lens 3, the color filter 5, and the micro-lens 7, are formed above the light-receiving element 1, offset towards a center of the light-receiving area, as shown in the right side of the diagram. In this manner, an existing solid-state image sensor forms a micro-lens in an offset position above a light-receiving element in a CCD image sensor light-receiving area, as a countermeasure for shortening of exit pupil distance. With this, an improvement of a light-collection rate for incident oblique light in the peripheral portion of the light-receiving area is promoted.
Furthermore, in a solid-state image sensor disclosed in official publication of Japanese Laid-Open Patent Application No. 06-326284, a transparent film with a lower refractive index than micro-lens material is provided, and deterioration of sensitivity upon lens stop release is minimized.
However, according to existing technology mentioned above, the shortening of exit pupil distance in response to slimming of mobile phone cameras and digital still cameras is reaching its threshold. For example, if the shortening of exit pupil distance should progress further with regard to the configuration in FIG. 1, the light-receiving elements will no longer be able to perform light-collection as intended, as shown in FIG. 2, and a problem of shading arises due to lack of sensitivity in the peripheral portion of the light-receiving area. In other words, from a center of an image, sensitivity deteriorates as a periphery of the image is neared, and a deterioration of image quality arises in which darkening worsens towards the periphery of the image.
In addition, due to the shortening of exit pupil distance, it is necessary to perform mask alignment with greater precision during a micro-lens formation process to form micro-lenses that are offset in appropriate positions for a case in FIG. 2 as well, and position alignment is becoming difficult in terms of design and production.
Furthermore, although deterioration of sensitivity upon lens stop release is reduced in the solid-state image sensor disclosed in official publication of Japanese Laid-Open Patent Application No. 06-326284, the same problem exists with regard to the shortening of exit pupil distance.

Solid-state image sensor, manufacturing method for solid-state image sensor, and camera

Matsushita Electric Industrial Co., Ltd.