An arrangement for generating an array (one- or two-dimensional) of optical beams, or spots, is disclosed. The array is particularly useful in conjunction with an array of optically sensitive devices utilized in applications such as optical computing or photonic switching. The array generator includes an optical gain medium and a partially reflecting mirror disposed to form an externally modulated laser arrangement. A diffraction grating, such as a Dammann grating, is disposed in the signal path to form the required array of optical beams. A wavelength control element, including transparent and non-reflecting regions, may be disposed beyond the output of the diffraction grating to provide optical feedback for wavelength stabilization of the gain medium.

1. Technical Field
The present invention relates to an optical power source for array illumination and, more particularly, to an externally modulated laser configuration.
2. Description of the Prior Art
Many advanced photonic systems such as optical computing and free-space photonic switching are based upon arrays of symmetric self-electrooptic effect devices (S-SEEDs). In these systems, the S-SEEDs function as detectors, logic elements, or modulators. Each system relies on arrays of light beams (modulated by the S-SEED arrays) to transmit information between components of the system. One method for producing the required light beam array is discussed in an article entitled "Binary phase grating generating even numbered spot arrays" by R. L. Morrison et al. appearing in the 1989 Technical Digest of the Optical Society of America, Annual Meeting (Vol. 18). The Morrison et al. article describes the beam array generator as comprising a laser diode source and a spot array generator mechanism, such as a grating and appropriate lensing. In operation, a collimating lens is coupled to the output of the laser diode, followed by a grating for producing a diffraction pattern related to the size and periodicity of the grating, and a Fourier transform lens disposed a focal length above the plane associated with the location of the spot array at the output of the grating. The optical Fourier transform lens functions to change the wavelength-dependent diffraction pattern into a spatial array (one- or two-dimensional) of beams, or spots.
Unfortunately, the above-described array generator mechanism requires stringent tolerances on the laser wavelength, since the spatial displacement of the light spots is a function of wavelength. For example, if the wavelength is too short or too long, the spot spacing is either reduced or expanded, respectively, such that extreme spots are no longer aligned with the underlying photosensitive device (e.g., S-SEED, 1- or 2-dimensional opto-electronic integrated circuits, photodiodes, etc.). As array size grows, wavelength control becomes more critical. Additionally, the photo-sensitive area of a SEED is concentrated within each cell to improve its performance. Therefore, the beam array must not only be wavelength-controlled, but physically aligned within the photo-sensitive area of the receiving device.
As photonic-based systems increase in size and speed, the need for higher power sources grows accordingly. In particular, the operating speed of a digital system is determined by the energy required to switch the state of an individual logic device and the capacity of the power supply. One such digital system may comprise a photonic switch capable of handling over a thousand channels modulated at about 100 MHz (on each channel). Such a system may comprise several modules with at least one S-SEED devoted to each channel. Given a switching energy of approximately one pJ and an optical efficiency of about 10% (for relaying the light from the laser to the S-SEED array and then on to the next module), a laser of about 1000 mW power would be required for each module.
A need remains in the art, therefore, for a light source capable of generating a spot array which is stable with wavelength and provides sufficient power for photonic system applications.

Externally modulated laser source for array illumination


The invention is directed to a treatment fluid comprising electrolyzed water and an amine, and methods for producing and using same in the treatment of a gas or liquid containing a contaminant such as an acid gas or a sulphur compound.

In upstream oil and gas operations, hydrocarbon liquids and gases are typically produced with some contaminants, such as acid gases and sulphur compounds. Acid gases are gases which form acidic solutions when mixed with water, and typically include hydrogen sulphide and carbon dioxide. Hydrogen sulphide is a colorless, flammable, poisonous gas, having a characteristic foul odor of rotten eggs. It may be produced from the bacterial breakdown of organic proteinaceous matter from plants or animals, or by contact at high temperatures between elemental sulphur or certain sulphur-containing compounds and organic materials. Hydrogen sulphide may also be formed as an undesirable byproduct in various industrial processes such as, for example, the production of coke from sulphur-containing coal; the refining of sulphur-containing crude oils; the production of disulphide; the manufacture of viscose rayon; and the Kraft process for conversion of wood into wood pulp.
Hydrogen sulphide may also be a byproduct of wastewater from treatment plants or water from agricultural practices. Unpleasant odors from liquids used in janitorial processes, RV holding tanks, portable toilets and the like are typically attributed to hydrogen sulphide. Such foul odors may be eliminated if the emission of hydrogen sulphide could be controlled in some manner.
Natural gas or crude oil having high concentrations of hydrogen sulphide are known as "sour gas" and "sour crude" respectively. Hydrogen sulphide in sour gas and crude oil streams is separated during gas sweetening processes, such as the widely used amine process which requires a solution of water and an amine to remove carbon dioxide and several sulphur compounds.
Since hydrogen sulphide is toxic, it represents a significant threat to public safety and health, and has potential to cause serious health risks in the oil and gas, livestock, waste management, and janitorial industries. At 200 ppm, hydrogen sulphide is undetectable by smell, and a concentration greater than 200 ppm induces nausea and headaches. At 500 to 1000 ppm, hydrogen sulphide leads to unconsciousness, with death resulting within two to twenty minutes unless the victim is removed immediately from exposure.
Other contaminants of natural gas or crude oil include sulphur compounds such as mercaptans.
There is thus a need for a simple, economical and effective means of removing contaminants such as acid gases or sulphur compounds from hydrocarbons or other gases or liquids.

This patent is subject to a terminal disclaimer.

Electrolized water—amine compositions and methods of use


A tripod (1) for mounting a camera or the like is disclosed. The tripod (1) comprises a support (5) having three legs (40) which are moveably mounted at a proximal end about the support (5) and circumferentially equidistant from each other. The legs (40) are moveable between an expanded configuration to support the tripod (1) and a folded configuration when the legs (40) lie adjacent to each other. In order to retain the legs in the folded configuration, at least one leg (40) includes a magnet (11) spaced distally along the leg (40) from the support. Each of the other two legs (40) includes a further magnet (12) or a magnetically attracted portion to magnetically engage the magnet (11) and releasably retain the tripod (1) in the folded configuration.

Tripod mounts providing a stable support for a device such as a camera and the like are well known in the art. A typical mount has a hub or support to which the device is attached and three legs which are hingeably or otherwise attached to the support which legs, in the extended or expanded position enable the device to be maintained in an orientation sufficiently stable to allow operation of the device.
The legs are moveable between the extended position in which the support is stabilised and the retracted or folded position in which the legs are effectively parallel to each other, and which enables the tripod to be more easily transported. in the retracted position there is usually a need to secure the legs together in order to prevent their relative movement during transport, which movement could cause damage or make carriage difficult.
In a previous application by the Applicant, GB 2374529, the use of a strap, along with the disadvantages associated therewith, was described whereby a strap was utilised to bind together the legs. The invention itself disclosed in GB 2374529 comprised a mechanical latch to hold the legs together. The latch mechanism could be actuated by the user, using only one hand.
The latch mechanism disclosed has the disadvantage however, particularly given its usual location towards the foot of a tripod leg, of being easily contaminated with water and dirt ingress which can lead to wear and corrosion of the mechanism and eventually hinder its function. Furthermore, the tripod user may be required to adjust the configuration of the tripod leg via an upper locking mechanism; while simultaneously operating a lower latch mechanism for releasing or restraining the tripods legs. This simultaneous use of the lower latch mechanism is awkward and/or uncomfortable for the tripod user.
It is an object of the current invention to provide a means for securing together the legs of a tripod together which addresses the above problems.


A plasma etching apparatus capable of accurately controlling the voltage levels of the pins and the temperature of the device under test in the etching process. The apparatus includes: a radiator, located below the table on which the device under test is placed, for releasing heat from the table; and a thermoelectric cooling element, located between the table and the radiator, for controlling temperature of the device under test on the table. The apparatus may also includes: a detachable adaptor, fixedly mounted on the table, made by an electrically and thermally conductive material, and having at least one trapezoidal ridge with trapezoidal cross section having sloping sides inclined by an angle larger than an angle of the pins of the device under test, for holding the device under test on a top face of the trapezoidal ridge with the pins hanging along the sloping sides; and a detachable holder, fixedly attached to the adaptor over the device under test, and having an opening through which the plasmas are injected onto the device under test, for pressing down the device under test with respect to the adaptor.

1. Field of the Invention
The present invention relates to a plasma etching apparatus for carrying out a manufacturing process of plasma etching.
2. Description of the Background Art
A plastic mold opening device such as that disclosed in Japanese Patent Application Laid Open No. 63-296229 has been known conventionally for opening up a device under test such as an IC chip in order to enable the analysis of malfunctions.
In a case where a further detail analysis of the interior of the IC chip is required, it is necessary to remove the passivation film on a chip surface. By removing the passivation film, it becomes possible to carry out the analysis operation to identify electrically malfunctioning parts by using a probe connected with a curve tracer or an oscilloscope. Also, if it is possible to use an electron microscope, the state of voltage level of each part of the chip can be comprehended without a contact by taking an electron micrograph of the chip in an operating state, so that the malfunctioning parts can easily be identified.
In general the passivation film of the chip is made of a surface layer of silicon nitride (Si.sub.3 N.sub.4) film and an inner layer of phosphosilicate glass (PSG) film. As a method for removing such a passivation film, a wet method and a dry method have been known conventionally.
In the wet method, the phosphoric acid solution heated up to approximately 180.degree. is used for removing the silicon nitride film, and the buffered hydrofluoric acid (ammonium fluoride solution) at the room temperature is used for removing the phosphosilicate glass film.
In the dry method, the silicon nitride film is removed by the dry etching due to a mixed gas of carbon tetrafluoride (CF.sub.4) and oxygen in an isotropic plasma etching apparatus, and the phosphosilicate glass film is removed by the dry etching due to a mixed gas of carbon tetrafluoride (CF.sub.4) and hydrogen, or a gas of a compound having a smaller ratio of C and F such as C.sub.3 F.sub.8 in an anisotropic plasma etching apparatus.
The plasma etching apparatus used in the dry method has a table provided on a base, which functions as an electrode, and on which a device under test such as an IC chip to be applied with the etching process is placed, and a freely openable chamber lid having another electrode to cover the device under test from above is provided over the table. In this plasma etching apparatus, the etching process can be applied to the device under test by supplying a gas to the discharge chamber formed by the table and the chamber lid in a state in which the chamber lid is closed and the device under test is placed between two electrodes, and by causing the plasma generation between two electrodes.
Now, in such a conventional plasma etching apparatus, although the device under test is fixed on the table, the pins of the IC chip in mutually insulated state can lead to the damaging of the IC chip during the etching process due to the differences among the voltage levels produced on the pins, so that it is necessary to maintain the pins at the same voltage level. Conventionally, this has been achieved by providing holes or grooves with constant interval in correspondence with the pins such that the pins can be fitted into the holes or grooves in order to prevent the generation of the voltage level differences.
On the other hand, in order to prevent the deterioration of the reproduction capability of the IC chip due to the variations of the etching processed parts on the device under test caused by the temperature increase during the repeated application of the etching operations in the etching process, it is necessary to control the temperature of the device under test during the etching process. Conventionally, this has been achieved by providing a cooler below the table from which the cooled water is circulated around the table in order to control the temperature of the device under test. However, this method makes the size of the apparatus very large and the cost of the apparatus very expensive. Also, in order to circulate the cooled water, the piping around the table is required, but such a piping interfered with the operations to be performed around the table.

Plasma etching apparatus with accurate temperature and voltage level control on device under test


A spacer device for a product employs a plurality of elongated first channel structures interconnected by a plurality of interconnecting support structures. The first channel structures have a pair of sidewalls, a top wall, a bottom wall and a pair of endwalls defining a channel interior. The support structures interconnect the first channel structures at spaced locations to hold them in spaced apart relation to form a first lattice having a plurality of openings to permit air circulation. Preferably, a similar second lattice is employed and is inverted and joined with the first lattice to create an endless channel. The support structures on each of the lattices are positioned to enclose the channel interiors on the other of the lattices. The spacer device may also be configured as a container with the lattice openings eliminated so that the spacer device forms an enclosure to contain products. Foam or fluid may be used to fill the channel interiors, if desired.

The method for preserving perishable foods has changed in recent years. Early preservation methods included smoking, salting, drying or canning. Presently, the most common method of preserving food is freezing. A variety of different types of products can be frozen, such as yogurt, ice cream and butter, along with meat products such as pork products, chicken products and beef products. When frozen products are boxed and refrigerated, spacers are usually placed between the layers of boxes. Accordingly, the change in preservation techniques to freezing products has increased the use of the spacer in many industries including the meat industry. The greatest proportion of these spacers, that are in common use, are constructed substantially of wood. Wooden spacers or pallets, however, have certain disadvantages. Wooden pallets have sharp edges and corners which can cause tears in the boxes containing the frozen products. Similarly, the wood pallets may damage the boxes by snagging the boxes on protruding nails or staples used to keep the pallet together. Furthermore, wooden spacers are relatively thick and heavy to provide the required compression strength to support the heavy frozen products. Moreover, wood pallets tend to deteriorate rapidly due to wear, warpage and breakage, therefore requiring not only frequent repairs but also large maintenance expenses.
As the food industry becomes more regulated, additional disadvantages relating to the use of wood pallets have been recognized. A pallet that is made of wood is basically an insulating product and thus, increases the time required to freeze the boxed food products placed thereon. Where the freezing of meat is concerned, this delay can increase the likelihood of bacteria growth. Likewise, unless the pallets are pre-cooled, frozen products, e.g., ice cream, may melt due to the thermal capacity of the pallet. Furthermore, the FDA is now scrutinizing the use of wood pallets in the meat industry to determine whether these pallets should be eliminated altogether due to the fact that wood absorbs blood from meat that may leak through the box. If a wood pallet is stained with blood, the pallet must be buried or burned, neither of which is particularly an environmentally sound practice. As an alternative to the use of a wood pallet, the industry has recently turned to the use of metal spacers. Metal spacers compared to wooden spacers decrease the time to freeze the products placed thereon. However, metal spacers, like wood spacers, tend to be heavy to provide the necessary stability. In my co-pending application Ser. No. 07/705,281, a metal spacer device is shown that is stable and lightweight. However, like wood pallets, most metal pallets can deteriorate quickly due to use and can snag boxes on protruding rivet or pallet edges. Therefore, the industry has limited also developed plastic spacers. There has been only a varying degree of success for plastic spacers. One plastic spacer, which is formed of a lightweight plastic, is called an "egg crate". For most products, the "egg crate" spacer tends to be too fragile and too flexible, making it very difficult to lift or move the spacer without boxes falling off of the edges. Another type of plastic spacer in use is formed by a structural foam molding process. Unlike the "egg crate" spacer, this spacer is sturdy; however, it tends to be heavy and it breaks or shatters easily.
Thus, there remains a need in the industry for a stable spacer that is lightweight. Furthermore, the spacer should be formed of a material that does not absorb liquid material which can leak from the products. The industry further requires that the spacer be formed of environmentally-friendly material which is capable of facilitating the freezing or chilling of the product. To this end, the present invention has been constructed to provide a relatively lightweight and strong spacer. Furthermore, the construction of the present invention addresses the industries needs for a durable, cleanable, recyclable spacer. Additionally, the present invention is constructed of material that decreases the time required to freeze the product placed thereon.


A non-rotating and axially secured connection between an inner joint part of a constant velocity joint and a driveshaft has an inner joint part at its outer circumference with tracks for receiving torque-transmitting balls or tripod arms for sliding on rollers, as well as a central bore with inner teeth. The driveshaft is inserted into the bore and is provided with corresponding outer teeth. At the end of the inner joint part facing the shaft end, the bore, with its inner teeth, changes into a through-hole with a smaller diameter. At the end of the driveshaft in front of the outer teeth, a cylindrical portion is provided carrying an axial securing mechanism.

The invention relates to a non-rotating and axially secured connection between an inner joint part of a constant velocity joint. The inner joint part, at its outer circumference includes tracks for receiving torque-transmitting balls or tripod arms for sliding on rollers. Also, the inner joint part includes a central bore with inner teeth. A driveshaft, provided with corresponding outer teeth, is inserted into the bore. The invention also relates to a method of producing the inner joint part and the connection.
Connections of this type have so far been designed in such a way that the inner joint part is provided with a through-hole with continuous inner teeth. For this purpose, a pressing produced for the inner joint part by a non-chip-forming deformation operation is initially provided with opposed cup-shaped regions for the through-hole, whereupon the end wall located therebetween is roughly stamped out. Subsequently, the through-hole is produced by turning, and finally, in the bore prepared in such a way the teeth are produced by broaching. The free end of the respective shaft is provided with outer teeth which have approximately the same length as the inner teeth of the inner joint part and which are followed by a stop collar. An annular groove is produced at the end of the shaft. The inner joint part is slid onto the shaft end and axially secured thereon by means of a securing ring inserted into the annular groove. The outer teeth at the shaft end may be produced in a non-chip-forming way by curling. With this type of connection and the method of producing it, it is particularly disadvantageous that the operation of producing the inner teeth at the inner joint part takes place in three consecutive process stages. (See FIGS. 5a through 5f.)

Connection between inner joint part and driveshaft


A motor vehicle fuel pump including a tubular shell, an electric motor in the shell having an armature shaft rotatable about a longitudinal centerline of the shell, and a pump assembly at one end of the shell having a first rotatable element therein and a second element therein between the first rotatable element and the electric motor. A barrel-shaped driver in a cavity between the first and second rotatable elements includes drive lugs on each longitudinal end projecting into corresponding drive sockets in the first and second rotatable elements. Each drive lug has a rounded edge engaging a side of the corresponding drive socket such that the driver is effectively decoupled from the first and second rotatable elements except with respect to force reactions establishing torsional force couples on the rotatable elements in planes perpendicular to the longitudinal centerline of the shell. The armature shaft has a distal end defining a drive tang received in a correspondingly shaped cavity in the barrel-shaped driver.

A motor vehicle fuel pump described in U.S. Pat. No. 4,445,820 includes and electric motor and a pair of closed-vane regenerative turbine pumps. The electric motor has an armature shaft rotatable about a longitudinal centerline of the pump and each turbine pump has a disc-shaped impeller rotatable about the longitudinal centerline of the pump independently of the armature shaft. A driver attached to an end of the armature shaft has a pair of bifurcated arms extending serially through apertures in the impellers whereby the impellers are drivingly connected to the armature shaft. A motor vehicle fuel pump according to this invention includes a driver of improved construction relative to the driver in the aforesaid U.S. Pat. No. 4,445,820 for drivingly connecting an electric motor armature shaft to a pair of rotatable elements in the pump.


The described embodiments include a computing device that executes a broker application. The broker application performs a mediated data exchange to exchange data between a first sandboxed application and a second application. For example, the broker application can import data from the second application into the first sandboxed application. As another example, the broker application can export data from the first sandboxed application into the second application.

Field
The described embodiments relate to computing devices. More specifically, the described embodiments relate to a mediated data exchange between sandboxed applications executing on a computing device.
Related Art
Some operating systems for computing devices support "sandboxing." Sandboxing is a technique that is used to prevent applications executing on a computing device from maliciously or mistakenly altering data (e.g., files) and/or misusing computational resources on the computing device. When "sandboxed," an application is permitted by the operating system to access only a limited set of resources in the computing device and is prevented from accessing data other than the application's own data. Thus, for example, in these computing devices, the application is allowed to freely access (i.e., read from, write to, delete, etc.) the application's own files, but the application is blocked by the operating system from accessing files belonging to other applications.
Although sandboxing is useful for preventing applications from maliciously or mistakenly altering data and/or misusing computational resources on the computing device, sandboxing significantly limits interactions between applications. For example, although being able to create and/or modify its own files, a sandboxed application is unable to communicate those files to another application or to receive files from another application. Placing such limits on the interactions for sandboxed applications can frustrate users, who are accustomed to non-sandboxed applications that can communicate freely. To avoid frustrating users, designers have provided workarounds to enable sandboxed applications to interact with other applications. For example, designers have added customized program code to one or both of the sandboxed application and the other application, as well as the operating system, to enable rudimentary interactions between a given sandboxed application and one other application. However, existing workarounds require that application program code and/or operating system code be modified on a case-by-case basis to enable the workarounds.
Throughout the figures and the description, like reference numerals refer to the same figure elements.

Mediated data exchange for sandboxed applications


In a textile-processing operation wherein a filament is displaced longitudinally continuously past a treatment station and a liquid is applied to the moving filament at the station, a supply of the liquid is held in a container spaced from the station and connected via a conduit to an applicator at the station. Space above the liquid in the container is filled with a gas that is devoid of free oxygen and that is in direct contact with the liquid. This gas above the liquid is pressurized in the container to controlledly force the liquid from the container through the conduit to the applicator at the station. The liquid is kept out of contact with oxygen until it actually has been applied to the filament. In fact the filament is passed over a small-diameter orifice formed in a guide and the liquid is forced from the orifice. The filament directly engages the guide at the orifice and covers the orifice so that the liquid does not contact the ambient air until after it is applied to the filament.

In many textile processes, for instance spinning and drawing, it is necessary to apply to a filament a process liquid that degrades rapidly when exposed to free oxygen or that can support bacterial life. Hence it is necessary in such processes to clean the equipment frequently and to work with small supplies of the processing liquid in order to ensure that it is used up before it spoils.

Protecting a textile process liquid before application to a filament


A positive resist composition based on a silicone polymer contains a photo acid generator which will decompose to generate an acid upon exposure to radiation. The silicone polymer includes hydroxybenzyl units wherein some OH groups are replaced by t-butoxycarbonyl, t-butoxycarbonylmethyl, trimethylsilyl or tetrahydropyranyl groups. In a first form, the photo acid generator is a specific onium salt having at least one phenyl group with a t-alkoxy, t-butoxycarbonyloxy or t-butoxycarbonylmethoxy substituent. In a second form, the composition further contains a nitrogenous compound. In a third form, the composition further contains a dissolution inhibitor in the form of a specific silicone compound. The composition is sensitive to high energy radiation and has high sensitivity and resolution.

1. Field of the Invention
This invention relates to a positive resist composition which is highly sensitive to high energy radiation such as deep-ultraviolet line, electron beam and X-ray, can be developed with alkaline aqueous solution to form a pattern, and is thus suitable for use in a fine patterning technique.
2. Prior Art
To comply with the LSI technology tending toward higher integration and higher speed, there were recently developed new resist materials which undergo acid-catalyzed chemical amplification. See Liu et al., J. Vac. Sci. Technol., Vol. B6, 379 (1988). Because of many advantages including a sensitivity at least comparable to conventional high-sensitivity resist materials, high resolution, and high dry etching resistance, the chemically amplified resist materials are regarded promising for deep-ultraviolet lithography. As to negative resists, a three-component chemically amplified resist material comprising a novolak resin, a melamine compound and a photo acid generator is commercially available from Shipley Co. under the trade name of SAL601ER7. At to positive resists, however, there have been commercially available no positive resist materials of the chemical amplification system. In the manufacture of LSIs, interconnection and gate formation can be managed using negative resists whereas the use of negative resists for contact hole formation obstructs fine processing due to fogging. There is a strong demand for high performance positive resist material.
In the past, Ito et al. developed a chemically amplified positive resist by adding an onium salt to a polyhydroxystyrene resin whose hydroxyl group is protected with a t-butoxycarbonyl (t-BOC) group, which is known as PBOCST. See Polymers in Electronics, ACS symposium Series No. 242, American Chemical Society, Washington D.C., 1984, page 11. Since the onium salt used therein contains antimony as a metal component, the PBOCST resist is not desirable from the standpoint of preventing contamination to the substrate.
Ueno et al. reported a deep-UV, chemically amplified positive resist based on poly(p-styreneoxytetrahydropyranyl) as having high sensitivity and high resolution. See No. 36 Applied Physics Society Related Joint Meeting, 1989, 1p-k-7. However, it was difficult to form a fine, high aspect ratio pattern at a high precision because of the mechanical strength thereof.
Many other reports have been made about such chemically amplified positive resist materials using novolak resins and polyhydroxystyrene as a base resin and being sensitive to deep-UV line, electron beam, and X-ray. All of them are single-layer resists. There still remain unsolved problems associated with substrate steps, standing wave resulting from optical reflection at the substrate, and difficulty to form high-aspect ratio patterns. These resist materials are unacceptable in practice.
The two-layer resist technique is recommended in order to form high-aspect ratio patterns on stepped substrates. To enable alkali development in the two-layer resist technique, silicone polymers having a hydrophilic group such as hydroxyl and carboxyl groups are required. Since the silicones having a hydroxyl group directly attached thereto, however, undergo crosslinking reaction in the presence of acid, it is difficult to apply such silanols to chemically amplified positive resist materials. While polyhydroxy-benzylsilsesquioxane is known as a stable alkali soluble silicone polymer, its derivatives obtained by protecting some hydroxyl groups with t-BOC form chemically amplified silicone system positive resist materials when combined with photo acid generators as disclosed in Japanese Patent Application Kokai (JP-A) No. 118651/1994 and SPIE, Vol. 19, 25 (1993), 377. However, silicone polymers are inadequate for fine patterning since they are less compatible with photo acid generators.
The above-mentioned resist materials also suffer from the problem of post-exposure delay (PED) inherently associated with chemically amplified positive resists. The PED problem is that after exposure, impurities such as amines and water in air diffuse into the resist film from its surface to create a distribution of impurities in the film. Because of the likelihood of acid being deactivated by such impurities at the surface, the pattern tends to have a "T-top" profile. There are available no silicone system positive resists which have solved the T-top problem associated with PED. There is a demand for a silicone system positive resist having high sensitivity and resolution.


Provided are genetically engineered cells comprising a neural stem cell and retroviral expression system in the neural stem cell, which is capable of expressing homeodomain transcription factor Nkx6.1 protein but does not express homeodomain transcription factor Irx3 protein or homeodomain transcription factor Nkx2.2 protein; which is capable of expressing homeodomain transcription factor Nkx6.1 protein and homeodomain transcription factor Irx3 protein; and which is capable of expressing homeodomain transcription factor Nkx2.2 protein or homeodomain transcription factor Nkx2.9 protein. Also provided are methods of generating such genetically engineered motor neurons, V2 neurons, and V3 neurons. Also provided are methods of treating subjects having a motor neuron injury or a motor neuron disease comprising implanting in injured/diseased neural tissue of the subject any of the provided genetically engineered cells, administering to such neural tissue retroviral expression systems which are capable of expressing the appropriate homeodomain protein(s), or transfecting neural stem cells with a retroviral vector, which is capable of expressing the required homeodomain transcription factor protein(s). Provided is a method of determining whether a chemical compound affects the generation of a motor neuron from a neural stem cell.

In many developing tissues, the generation of distinct cell types is initiated by the action of extracellular signals provided by local organizing centers. Certain signals have the additional feature of directing distinct cell fates at different threshold concentrations, and thus function as morphogens (Wolpert, 1969). In Drosophila, the patterning of embryonic segments and imaginal discs involves the graded signaling activities of the Hedgehog, Wingless and TGFβ-related proteins (Lawrence and Struhl, 1996). In vertebrate embryos the specification of mesodermal cell types has similarly been suggested to depend on the graded signaling activity of members of the TGFβ family (Smith, 1995; McDowell and Gurdon, 1999). The generation of cell pattern through morphogen signaling demands an effective means of converting graded extracellular activities into all-or-none distinctions in cell fate. But the mechanisms used to achieve such conversions have been poorly defined, particularly in vertebrate tissues.
In the developing vertebrate nervous system, Sonic hedgehog (Shh) appears to function as a gradient signal. The secretion of Shh by the notochord and floor plate controls the specification of ventral cell types (Marti et al., 1995; Roelink et al., 1995; Chiang et al., 1996; Ericson et al., 1996). Five distinct classes of ventral neurons can be generated in vitro in response to progressive two-to-three fold changes in extracellular Shh concentration (Ericson et al., 1997a, b). Moreover, the position at which each of these neuronal classes is generated in vivo is predicted by the concentration of Shh required for their induction in vitro: neurons generated in progressively more ventral regions of the neural tube require correspondingly higher concentrations of Shh for their induction (Ericson et al., 1997a). These observations have led to the view that the position that ventral progenitor cells occupy within a ventral-to-dorsal gradient of extracellular Shh activity directs their differentiation into specific neuronal subtypes (Ericson et al., 1997b).
In turn, these findings have focused attention on the steps by which graded Shh signaling directs the diversification of neural progenitor cells. Several homeodomain proteins, Pax7, Pax3, Pax6, Dbx1, Dbx2 and Nkx2.2, are expressed by ventral progenitor cells and their expression is regulated by Shh signaling (Goulding et al., 1993; Ericson et al., 1996; Ericson et al., 1997a; Briscoe et al., 1999; Pierani et al., 1999). Moreover, the pattern of generation of certain ventral neuronal subtypes is perturbed in mice carrying mutations in these Pax genes and in the Nkx2.2 gene (Ericson et al., 1997a; Mansouri and Gruss, 1998; (Briscoe et al., 1999), supporting the view that homeodomain proteins expressed by ventral progenitor cells regulate neuronal subtype identity. However, two important aspects of the link between Shh signaling and neuronal identity remain obscure. First, it is unclear how the presumed extracellular gradient of Shh activity results in stable and sharply delineated domains of homeodomain protein expression within ventral progenitor cells. Second, the spatial information provided by the homeodomain proteins characterized to date is insufficient to explain the diversity of neuronal subtypes generated at different dorsoventral positions.
In the first series of experiments these two issues are addressed. It is show first that the homeodomain proteins Nkx6.1 and Irx3 are expressed by progenitor cells in discrete domains of the ventral neural tube and are regulated by graded Shh signaling. The differential expression of five class I (Shh-repressed) proteins, Pax7, Irx3, Dbx1, Dbx2 and Pax6, and two class II (Shh-induced) proteins, Nkx6.1 and Nkx2.2, subdivides the ventral neural tube into five cardinal progenitor domains. Misexpression of individual proteins in the neural tube in vivo in these experiments provides evidence that cross-repressive interactions between class I and class II proteins establish individual progenitor domains and maintain their sharp boundaries, suggesting a mechanism by which graded Shh signals are converted into all-or-none distinctions in progenitor cell identity. In addition, the experiments show that the spatial patterns of expression of Nkx6.1, Irx3 and Nkx2.2 are sufficient to direct both the position and fate of three neuronal subtypes generated in ventral third of the neural tube. These findings suggest a model of ventral neuronal patterning that may provide insight into how extracellular signals are interpreted during the patterning of other vertebrate tissues.
Distinct classes of neurons are generated at defined positions in the ventral neural tube in response to a gradient of Sonic Hedgehog (Shh) activity. A set of homeodomain transcription factors expressed by neural progenitors act as intermediaries in Shh-dependent neural patterning. These homeodomain factors fall into two classes: class I proteins are repressed by Shh and class II proteins require Shh signaling for their expression. The profile of class I and class II protein expression defines five progenitor domains, each of which generates a distinct class of post-mitotic neurons. Cross-repressive interactions between class I and class II proteins appear to refine and maintain these progenitor domains. The combinatorial expression of three of these proteins—Nkx6.1, Nkx2.2 and Irx3—specifies the identity of three classes of neurons generated in the ventral third of the neural tube.
Sonic hedgehog (Shh) signaling has a critical role in the control of neuronal fate in the ventral half of the vertebrate central nervous system (CNS). The genetic programs activated in Shh-responsive progenitor cells, however, remain poorly defined. To test whether members of the Nkx class of homeobox genes have a prominent role in the specification of ventral cell types the second series of experiments examined patterns of neurogenesis in mice carrying a targeted mutation in the Nkx class homeobox gene Nkx6.1. In Nkx6.1 mutants there is a dorsal-to-ventral switch in the identity of progenitor cells and in the fate of post-mitotic neurons. At many axial levels there is a complete block in the generation of V2 interneurons and motor neurons and a compensatory ventral expansion in the domain of generation of V1 neurons. These studies support the idea that an Nkx gene code controls regional pattern and neuronal fate in the ventral region of the mammalian CNS.

Homeodomain protein code specifying progenitor cell identify and neuronal fate in the ventral neural tube

The Trustees of Columbia University in the City of New York


A wireless device receives a frame including a first Resource Unit (RU) allocation subfield including resource information for a first frequency area and indicating a first number of user fields in a first channel that correspond to the first frequency area, and a second RU allocation subfield including resource information for a second frequency area and indicating of a second number of user fields in a second channel that correspond to the second frequency area. When the first and second frequency areas are a same RU, the wireless device determines, using both the RU allocation subfields, a number of users allocated to the same RU. A wireless device generates and transmits a frame including first and second RU allocation subfields as described above. When the first and second frequency area are a same RU, both the RU allocation subfields indicates a number of users allocated to the same RU.

1. Technical Field
The technology described herein relates generally to wireless networking. More particularly, the technology relates to Multi-User Multiple-Input-Multiple-Output (MU-MIMO) and Orthogonal Frequency Division Multiple Access (OFDMA) communications in a wireless network.
2. Description of the Related Art
Wireless LAN (WLAN) devices are currently being deployed in diverse environments. Some of these environments have large numbers of access points (APs) and non-AP stations in geographically limited areas. In addition, WLAN devices are increasingly required to support a variety of applications such as video, cloud access, and offloading. In particular, video traffic is expected to be the dominant type of traffic in many high efficiency WLAN deployments. With the real-time requirements of some of these applications, WLAN users demand improved performance in delivering their applications, including improved power consumption for battery-operated devices.
A WLAN is being standardized by the IEEE (Institute of Electrical and Electronics Engineers) Part 11 under the name of "Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications." A series of standards have been adopted as the WLAN evolved, including IEEE Std 802.11™-2012 (March 2012) (IEEE 802.11n). The IEEE Std 802.11 was subsequently amended by IEEE Std 802.11ae™-2012, IEEE Std 802.11aa™-2012, IEEE Std 802.11ad™-2012, and IEEE Std 802.11ac™-2013 (IEEE 802.11ac).
Recently, an amendment focused on providing a High Efficiency (HE) WLAN in high-density scenarios is being developed by the IEEE 802.11ax task group. The 802.11ax amendment focuses on improving metrics that reflect user experience, such as average per station throughput, the 5th percentile of per station throughput of a group of stations, and area throughput. Improvements may be made to support environments such as wireless corporate offices, outdoor hotspots, dense residential apartments, and stadiums.
An HE WLAN supports Down-Link (DL) and Up-Link (UL) Multi-User (MU) transmissions such as MU Orthogonal Frequency Division Multiple Access (MU OFDMA) transmission, Multi-User Multi-Input-Multi-Output (MU MIMO) transmissions, and MU transmissions that use both OFDMA and MU-MIMO. Collectively, transmissions using OFDMA, MU-MIMO, or both are referred to herein as MU transmissions.
MU communication as define herein are distinguished from other transmissions, such as broadcast transmissions, by the allocation in the MU communication of only a portion of the channel (such as a sub-channel in an OFDMA communication, one or more spatial streams in an MU-MIMO communication, or one or more spatial streams of a sub-channel in a communication using both OFDMA and MU-MIMO) to a particular communication.
Each of MU frames transmitted by the stations using OFDMA may include a first portion transmitted across an entire bandwidth of a wireless channel and one or more second portions transmitted to or by respective stations using respective portions of the bandwidth of and respective spatial streams of the wireless channel. The respective second portions of the MU OFDMA frames are each transmitted using one or more spatial streams of respective bandwidths (that is, respective subchannels) allocated exclusively to each second portion. The information on which bandwidths, which spatial streams, or both that are allocated to which stations in the second portion of the frame may be communicated to the stations using an HE Signal-B (HE-SIG-B) field included in a first portion of the MU OFDMA frame or in a preceding frame, such as a trigger frame.
An AP may allocate respective bandwidths, respective spatial streams, or both to each of one or more stations participating in an MU communication. Each allocation must then be communicated to the respective station.

Resource allocation indication for multi-user multiple-input-multiple-output (MU-MIMO) orthogonal frequency division multiple access (OFDMA) communication


An electrically powered hammer comprising a hollow spindle within which spindle is reciprocatingly mounted a piston, a ram, a beatpiece having an increased external diameter mid-portion and located within the spindle between the ram and the tool or bit, a two part sleeve arrangement located within the spindle and including an increased internal diameter mid-portion for receiving the increased external diameter portion of the beatpiece and a reduced internal diameter forward and rearward portion for guiding the forward and rearward ends respectively of the beatpiece and where the sleeve arrangement includes a forward sleeve and a rearward sleeve which are both guided with tight radial tolerances and with a slight axial play within and by the spindle and the forward axial movement of the forward sleeve is limited by a reduced diameter portion of the spindle and the forward axial movement of the rearward sleeve is limited by the forward sleeve.

1. Field of the Invention
This invention relates to electric hammers having an air cushion hammering mechanism.
2. Description of the Related Art
Such hammers will normally have a housing and a hollow cylindrical spindle mounted in the housing. The spindle allows insertion of the shank of a tool or bit, for example a drill bit or a chisel bit, into the front end thereof so that it is retained in the front end of the spindle with a degree of axial movement. The spindle may be a single cylindrical part or may be made of two or more cylindrical parts, which together form the hammer spindle. For example, a front part of the spindle may be formed as a separate tool holder body for retaining the tool or bit. The hammer is normally provided with an impact mechanism comprising a motor that drives a piston, which may be a hollow piston, to reciprocate within the spindle. The piston reciprocatingly drives a ram by means of an air cushion located between the piston and the ram. The impacts from the ram are transmitted to the tool or bit of the hammer via a beatpiece located within the spindle.
Some hammers can be employed in combination impact and drilling mode in which the spindle, or a forwardmost part of the spindle, and hence the bit inserted therein, will be caused to rotate at the same time as the bit is struck by the beat piece.
When the hammer is to be used the forward end of a tool or bit is pressed against a workpiece, which urges the tool or bit rearwardly within the hammer spindle. The tool or bit in turn urges the beatpiece rearwardly into its operating position in which the rearward end of the beatpiece is located within the reciprocating path of the ram. In the operating position the beatpiece receives repeated impacts from the ram. When the hammer is in use, the forward impact from the ram is transmitted through the beatpiece to the bit or tool and through the bit or tool to the workpiece. A reflected impact is reflected from the workpiece and is transmitted through the bit or tool to the beatpiece. This reflected, or reverse impact must be absorbed within the structure of the hammer in such a way that the reverse impacts do not over time destroy the hammer and so that the reverse impacts are not transmitted to the end user.
When the user takes the tool or bit of the hammer away from the workpiece, the next forward impact of the ram on the beatpiece urges the beatpiece forwardly into its idle mode position. The beatpiece can move forwardly and stay forwardly because the tool or bit is no longer urging it rearwardly, because the tool or bit also assumes a forward idle mode position. Because the beatpiece does not now offer much resistive force against the ram, the ram also moves into a forward idle mode position. In the idle mode position of the ram, the air cushion is vented and so any further reciprocation of the piston has no effect on the ram. This forward movement of the components on entry into idle mode generates the greatest impact forces on the structure of the hammer, in particular on the hammer spindle. This is because the forward impact force of these parts on entry into idle mode is not transferred to the workpiece, but has to be absorbed by structure of the hammer itself. Thus, the number of idle strikes, ie. the number of reciprocations of the ram, beatpiece and tool or bit, when the bit or tool is removed from the workpiece need to be minimised in order to minimise the number of high impact force idle strikes that have to be absorbed by the structure of the hammer. This is generally achieved by catching the ram and/or the beatpiece in their idle mode positions so that they cannot slip rearwardly to cause the ram to move into a position in which the air cushion is closed and the ram and thus the beatpiece begin to reciprocate again.
In order for the maximum impact to be transmitted from the ram to the tool or bit, via the beatpiece, the beatpiece must be co-axial with the spindle. Thus, high efficiency is achieved if the reciprocating movement of the beatpiece within the spindle is guided to ensure good axial alignment with the axis of the spindle.
Hammers are necessarily operated in very dusty and dirty environments. If dust gets into the spindle of the hammer it can cause abrasion between the reciprocating parts and, in particular, can cause seals between the ram and the spindle to become worn. Wearing of the seal around the ram will cause the air cushion to deteriorate, which will eventually lead to impacts occurring between the beatpiece and the ram which can seriously damage the hammer. Therefore, a further issue in the longevity of the working life of a hammer is its sealing against dust. The reciprocation of parts within the spindle can draw dust rearwardly inside the hammer spindle, where damage can be caused.
Attempts to solve these problems have been made and examples of the resulting hammer arrangements are known from U.S. Pat. No. 4,476,941 and DE196 21 610.
The arrangement in U.S. Pat. No. 4,476,941 has a complicated multi-part spindle arrangement with a first sleeve for guiding a rearward reduced diameter portion of the beatpiece, which sleeve extends from the inside to the outside of the spindle, between two spindle parts. The impact of the beatpiece on entry into idle mode is absorbed by a second sleeve, located forward of the first and within a different one of the spindle parts. The second sleeve also guides a forward increased diameter portion of the beatpiece. The arrangement in U.S. Pat. No. 4,476,941 has a problem with dust ingress, in particular during periods when a tool or bit is removed from the tool holder of the hammer, into the portion of the forward sleeve where the beatpiece is guided. This problem is exacerbated by the pumping nature of the increased diameter portion of the beatpiece which is guided within the second sleeve. The small amount of axial support for the first sleeve which is mounted between spindle parts, along with usual tolerance limitations for component parts could lead to a reduced accuracy of axial guiding of the beatpiece by the sleeves. The design in U.S. Pat. No. 4,476,941 results in a complicated multi-part spindle, beatpiece guiding and damping structure, with the associated assembly problems and cost implications.
The arrangement in DE196 21 610 overcomes some of the problems discussed above, but still has the disadvantage of a relatively complex three part spindle arrangement, having sleeves for beatpiece guiding mounted and guided in different spindle parts. Again the usual tolerance issues between spindle parts can reduce the accuracy with which the beatpiece is guided and complicates the sealing of dust from the inside of the spindle. Again the design in DE196 21 610 has a complicated multi-part spindle, beatpiece guiding and damping structure, with the associated assembly problems and cost implications.


Multi-functional practice and training apparatus for use by skateboarders, skaters, bicyclists and the like. According to a preferred embodiment, the system comprises the combination of a board with a fulcrum member that are operative to assume at least three practice modes, namely: 1) a ramp mode whereby the fulcrum is placed at one end of the board and creates an upward slope for use in riding or jumping over objects; 2) a seesaw mode whereby the board is pivotally mounted upon the fulcrum and provides a platform surface upon which the user can rock back and forth while standing or riding thereon; and 3) a rigid rail structure whereby the fulcrum defines a rail for use in xe2x80x9cgrinding.xe2x80x9d

(Not Applicable)
(Not Applicable)
Skateboarding, in-line skating and stunt bicycling are well-known activities enjoyed by millions of individuals worldwide. In this regard, such activities are not only fun, but are also great forms of exercise and serve to develop balance and coordination.
Such activities, however, are often very difficult to master and require tremendous amounts of time and effort before a skater or rider can become proficient. The balance and coordination necessary to master skateboarding, in-line skating and the like is typically of exceptional importance insofar as such activities can become very dangerous, and often involve tricks and stunts that could lead to serious and permanent injury if attempted by individuals lacking the requisite levels of skill. For example, skateboarding typically involves jumping over stationary objects at relatively high speeds, as well as gliding across rigid surfaces, such as cement curbs and the like and referred to as xe2x80x9cgrinding.xe2x80x9d Skateboarding, in-line skating, and stunt bicycling also typically involve jumping off ramps and the like to thus become xe2x80x9cairborne.xe2x80x9d
While safety equipment such as helmets, elbow pads, and knee pads, can offer protection against falls and accidents, there is still lacking any method by which a skateboarder or skater can practice his or her skills or otherwise become proficient in mastering the basic maneuvers required for such activities. In this regard, except for a few isolated areas where skateboard parks and the like are available, skateboarders, skaters and the like must typically resort to practicing in parking lots, neighborhoods and city streets, which not only cause a tremendous amount of nuisance to resident and business owners, but can also cause substantial property damage. Practicing in such areas can also increase the number and risk of accidents related to such activities by increasing the possibility a given skateboarder or skater will run into or be hit by a vehicle or other stationary or moving object (e.g., lampposts, mailboxes, pedestrians, other skateboarders, etc.). Indeed, the nuisance associated with skateboarding and skating has caused a number of communities to pass laws banning such activities. Furthermore, many businesses and residents have placed physical barriers, such as caps and mounts bored into concrete, which prevent skateboarders from grinding or otherwise practicing thereon.
Even to the extent skateboard parks and the like offer a place where skateboarders and skaters can attempt to practice their skills, such facilities are few in number and typically overcrowded. There is also a substantial difficulty for most skateboarders and skaters, which are typically adolescents that are unable to drive, to access such facilities.
Accordingly, there is a substantial need in the art for a system by which a skateboarder, skater or bicyclist can easily and readily access and practice a variety of maneuvers on-site. There is a further need for such a system that is versatile and operative to assume different configurations to thus enable a variety of skills to be practiced. Still further, there is a need in the art for such a system that is space-efficient, exceptionally durable, easy to utilize, inexpensive to manufacture, and readily capable of being used with virtually all types of skateboards, skates, stunt/mountain bikes, scooters, and the like.
The present invention specifically addresses and alleviates the above-identified deficiencies in the art. In this regard, the present invention is directed to a system for training and practicing skateboarding, skating and stunt/off-road bicycling skills. The present invention may be used for other wheeled vehicles, such as scooters and the like.
According to the preferred embodiment. The system comprises the combination of a flat board/platform member supported by a stationary fulcrum. The platform defines a first upper surface upon which the vehicle can ride across, and an underside portion having at least one and preferably two socket members affixed thereto. The socket members are designed to engage with the fulcrum, and preferably include a first socket member disposed centrally underneath the board and across the width thereof, and a second socket member extending across the width of the board underneath a respective end thereof. The fulcrum member preferably comprises the combination of a base member with an upwardly extending ball element engageable with a respective one of the sockets formed on the underneath portion of the board platform such that when interconnected to one another, a ball and socket joint is formed. It is contemplated, however, that alternative board and fulcrum arrangements may be utilized in the practice of the present invention.
The arrangement between the board and fulcrum are such that the system of the present invention may take a variety of modes to thus enable a variety of skills to be practiced. In this respect, it is contemplated that the systems of the present invention may take at least three modes, namely, a first mode whereby the board and fulcrum serve to define a ramp member to thus enable skateboarders, riders and the like to practice jumps and to leap over objects. To achieve that end, the fulcrum is attachable to the socket disposed upon a respective end of the board. In a second mode, the board and fulcrum are interconnected to one another via the centrally disposed socket to thus enable the board to see-saw back and forth. In this regard, the fulcrum member engages with the centrally-disposed socket to thus enable the board to see-saw back and forth while the rider stands thereupon. In a third configuration, the board may be rigidly affixed to the fulcrum along the centrally disposed socket thereof to define a rigid t-shape. In such configuration, the platform surface can serve as either an object for skateboarders and skaters to jump over or, alternatively, provide a ridge-like surface to enable skateboarders to practice grinding. In an alternative configuration, the fulcrum itself may be utilized for grinding. In this latter configuration, the fulcrum may be formed as an elongate member defined by a base and upwardly extending ball member. Preferably, such elongate fulcrum may be configured such that the upwardly extending ball member may be set at an incline relative level ground to thus enable skateboarders to practice grinding on inclines.
In all embodiments of the present invention, the system may be fabricated from exceptionally durable materials that can withstand vigorous impact, including durable plastics, metal, wood and the like, as well as combinations thereof. It is further contemplated that the fulcrum component may include a variable height adjustment mechanism to thus enable the board/platform to be selectively set at a desired height for a given mode.
The present invention thus provides a multi-purpose system for facilitating the training and practice for skateboarders, skaters, bicyclist and the like that can easily and readily be utilized to practice a wide variety of skills.
The present invention further provides a system that is operative to function in at least three (3) different modes, namely, a ramp, a see-saw, and a grinding rail surface to thus enable multiple skills to be practice by skateboarders.
The present invention further provides a system that is of simple construction, inexpensive to manufacture, easy to use, and may be utilized for a wide variety of wheeled vehicles, including but not limited to skateboards, in-line skates, bicycles, scooters, and the like.
The present invention still further provides a system that enables skateboarders, skaters, bicyclists, and the like to practice skills to develop balance and coordination that does not require such individuals to utilize private or public land, cause nuisance to business owners or home owners, does not violate most city ordinances, does not require the use of a skateboard park facility, and can be utilized virtually everywhere.


In a piano which is enabled to provide performance using electronic sound source as well as normal piano play, the proposed piano is such a piano where there is no difference of balance between the normal piano play and the play using electronic sound source. When key is moved in an electronic sound source mode, CPU detects a number n of the key (S110), detects a time lag .DELTA. T between the timings at which blockage is caused between light emitting elements and light receiving elements of both key sensors (S120), and calculates a velocity V according to the time lag .DELTA. T (S130). Then, performance data is prepared according to these key depression information, at the performance data preparation routine (S140), and a delay time Td corresponding to the velocity V is determined by using a delay time determination table (S150). Subsequently, it is determined whether the delay time Td has elapsed (S160). When it has elapsed, the performance data is outputted to the electronic sound source (S170). As a result, sound is created, with the delay time Td, according to the key depression intensity as an interval after the key depression.

Such a piano has been proposed which has an electronic sound source combined with acoustic piano. This realizes performance using the electronic sound source as well as normal piano play.
In the stated kind of piano it is known to provide a mechanism which prevents the action caused by key depression from being transmitted to hammers such that normal play sound that would be otherwise created by striking strings (hereinafter referred to as string striking-sound) is eliminated during performance using electronic sound source. Thus, string striking-sound is not generated during the performance using electronic sound source.
During the performance using electronic sound source, stepped shutters and first and second key sensors, provided below keys and on the main body of a piano, respectively, serve as detection means for detecting actions related to key depression and key release. The first and second key sensors are comprised of a pair of a light emitting element and light receiving element. When there is a blockage between these elements, on-signal is generated. When a key is depressed, the stepped shutter first eclipses the light path of the first key sensor, and then, with a specified interval of time, eclipses the light path of the second key sensor. The timing and the time lag of such light path blockage at the first and second key sensors are detected by control means operating to control electronic sound source. The control means then prepares, according to control program, performance data in the form of control signal and sends it to the electronic sound source. Consequently, play sound is generated at the electronic sound source.
According to the described prior art, the output of the performance data by the control means toward the electronic sound source is simultaneous to the on-signal at the second key sensor. Therefore, once the light path is blocked at the second key sensor, sound goes off immediately after at the electronic sound source.
However, the string striking-sound generated when the piano is played as a normal piano is caused by the kinetic energy of key depression which is transmitted to a hammer and causes it to strike a string. Since such process takes a substantial time period, there is a difference between the sound emission, or note-on, timing of the string striking-sound during normal piano play and that of the sound generated at the electronic sound source, thereby leading to an imbalance of created performance as a whole between the normal piano play and a play using electronic sound source. As a result, a player feels awkward when he plays using one of the sound source after using the other sound source.


An image detection method is disclosed wherein local edge information within an image is utilized for accurately detecting lines and curves of the images. The method can more accurately determine the location and orientation of a pattern and thus provides more reliable image match for pattern detection. A detector is trained off-line with example images resulting in a stored template generated by recording a test pattern similar to a pattern to be tested; anchor lines are identified within said template. Long lines are detected in subsequent test patterns using the disclosed method. The template is rotated and shifted before matching it to the test pattern so that anchor lines align with long lines detected within the test pattern. The template and test pattern are then compared to determine whether there is a match. The system comprises a microprocessor is programmed to facilitate the training of a detector off-line with example images which are scanned into said system wherein a template is generated by recording an image pattern of said example images similar to a test pattern to be detected. The microprocessor identifies anchor lines within the template. It detects the long lines using the disclosed line detection method; rotates and shifts the template before matching it to the test pattern so that anchor lines align with lines which are detected within said test pattern; and compares the template to the test pattern to determine whether said anchor lines exist within said test pattern.

This invention is generally related to electronic image recognition techniques and, more particularly, to an electronic image detection method wherein local edge information is utilized for detecting lines and curves.
A fundamental problem in electronic image recognition is line detection, or more generally, curve detection. In many applications, we want to find lines or other simple curves in a complex image or document. In a pre-scan image lines might be detected to decide where the edges of a paper document are. Within a document text lines may be used to estimate the skew angle of the document. Also, line and other simple curve detection often serves as the first step for complex object detection, as the contour of a complex object can always be decomposed into simple curves.
One example application of line detection is currency detection. The ability to detect currency patterns in an image can be useful in color copier machines or scanners for the purpose of preventing counterfeiting. The challenge of incorporating such a method in current copier or scanning technology lies in the difficulty with detecting images in a rotation or shift invariant manner. Specifically, the pattern could be of any orientation and at any location of the image. The orientation and the location of the image can be relatively simple to estimate using the line detection techniques.
Examples of skew angle identification and correction can be found in the following patents:
U.S. Pat. No. 5,528,387 to Kelly et al., issued Jun. 18, 1996, which teaches electronic image registration in a scanner. In particular, the edge data of a document is detected and skew angle calculated. The image is then rotated based upon the skew angle and non-image areas are filled using an image generation feature.
U.S. Pat. No. 4,922,350 to Rombola et al., issued May 1, 1990, discloses a two-pass scanning apparatus for detecting the size and position of an original document on a scanner platen. Image signals captured on a first scan are employed to determine boundaries and a best-fit magnification so that the image may be fed to a recording sheet using image signals generated on a subsequent scanning pass.
U.S. Pat. No. 5,253,765 to Moorehead et al, issued Oct. 19, 1003, teaches a system for sorting randomly sized objects (e.g. mushrooms). Invariant moments are employed, utilizing the complete pixel information for all pixels within the border of a captured image, to extract information about the mushroom size and orientation.
U.S. Pat. No. 5,220,398 to Horn et al. teaches an analog VLSI microchip that uses moments to determine the position and orientation of an object in a scene.
In xe2x80x9cInvariant Fitting of Planar Objects by Primitives,xe2x80x9d published in 1996 IEEE Proceedings of ICPR ""96, pp. 508-512 Voss et al, teach a method of pattern recognition using primitives such as triangles, rectangles, circles, ellipses, superquadratics, etc. The authors further describe a technique for describing the primitives using moments in a normalized manner; resulting in a decrease in the numerical effort.
In xe2x80x9cManaging and Representing Image Workflow in Prepress Applications,xe2x80x9d Technical Association of the Graphic Arts (TAGA) Vol. 1, 1995 Proceedings, pp. 373-385, Venable et al. teach the use of structured images to manage prepress workflow.
The Hough Transform, is probably the most important and most widely-used algorithm for curve detection. The Hough Transform utilizes global feature information (sets of points belonging to a given curve) efficiently. However, prior applications totally ignore local information. This disclosure proposes to improve the Hough Transform by exploiting local information within images and documents. For each detected point a local edge direction is first estimated. This can be done by many standard methods such as that described by A. Rosenfeld and A. C. Kak in an article entitled xe2x80x9cDigital Picture Processingxe2x80x9d, Academic Press, Inc., where a Sobel operator is used for gray images. The orientation of the estimated local edge controls the accumulation process in the Hough Transform. The disclosed method requires less computation and is more reliable in detection.
The counterfeit detection art includes methods that rely on point detection during recognition. As disclosed in U.S. Pat. No. 5,533,144 to Fan, entitled xe2x80x9cAnti-counterfeit pattern detector and methodxe2x80x9d, an anti-counterfeit detector and method identifies whether a platen image portion to be photocopied contains one or several note patterns. With the 144 method, the detection is performed in a rotation and shift invariant manner. Specifically, the pattern can be of any orientation and at any location of the image and can be embedded in any complicated image background. The image to be tested is processed block by block. Each block is examined to see if it contains an xe2x80x9canchor pointxe2x80x9d by applying an edge detection and orientation estimation procedure. For a potential anchor point, a matching procedure is then performed against stored templates to decide whether the pre-selected monetary note patterns are valid once detected.
Other pattern detection methods are presented by the following patents:
U.S. Pat. No. 4,153,897 Yasuda, et. al. Issued May 8, 1979
U.S. Pat. No. 5,216,724 Suzuki, et. al. Issued Jun. 1, 1993
U.S. Pat. No. 5,291,243 Hecknam, et. al. Issued Mar. 1, 1994
Yasuda et al. discloses a pattern recognition system where similarities between unknown and standard patterns are identified. Similarities are detected at first in respective shifting conditions where the unknown and standard patterns are relatively shifted from each other over the first limited extent, including the condition without shift. The maximum value of these similarities is then detected. The similarities are further detected in respective shifting conditions where the unknown and standard patterns are relatively shifted from each other over the second extent larger than the first limited extent, when the shifting condition which gave the maximum value is that without relative shift.
Suzuki et al. discloses an apparatus for image reading or processing that can precisely identify a particular pattern, such as banknotes or securities. A detecting unit detects positional information of an original image and a discriminating unit extracts pattern data from a certain part of the original image to discriminate whether the original image is the predetermined image based on the similarity between the pattern data and the predetermined pattern.
Heckman et al. discloses a system for printing security documents which have copy detection or tamper resistance in plural colors with a single pass electronic printer. A validating signature has two intermixed color halftone patterns with halftone density gradients varying across the signature in opposite directions, but different from the background.
All of the references cited herein are incorporated by reference for their teachings.
In order to more reliably and efficiently detect lines and curves, an electronic image detection method is now disclosed wherein local edge information is utilized. A currency detection method and system based on the disclosed line detection method is also presented.
With the presented method, the local edge information is applied to improve the line detection; the orientation of the local edge controls the accumulation process in Hough Transform.
With the presented currency detection method, a detector is trained off-line with example images resulting in a template generated by recording a test pattern similar to an image pattern to be tested; anchor lines are identified within the template; the long lines are detected during the testing using the disclosed line detection method; the template is rotated and shifted before matching the template to the test pattern so that the anchor lines align with long lines detected within the test pattern; and the template and the test pattern are compared to determine whether there is a match.
The method can be carried out in a system having a microprocessor programmed to carry out the above steps of the method. The system""s microprocessor facilitates the training of a detector off-line with example images which are scanned into the system wherein a template is generated by recording an image pattern of the example images (patterns) similar to a test pattern to be detected. The microprocessor identifies anchor lines within the template; detects long lines during testing using the disclosed line detection method; rotates and shifts the template before matching the template to the test patterns so that the anchor lines align with long lines which may be detected within the test pattern, and compares the template to the test pattern to determine whether the anchor lines exist within the test pattern.
Other objects, advantages, and salient features of the invention will become apparent from the detailed description which, taken in conjunction with the drawings, disclose the preferred embodiments of the invention.

Line and curve detection using local information


A laundry treating apparatus comprising a cabinet including a laundry introduction port, a door to open and close the introduction port, a hinge unit configuring a first rotating axis and a second rotating axis, the hinge unit including a first shaft and a second shaft configuring the first rotating axis and a third shaft and a fourth shaft configuring the second rotating axis, and a rotating shaft shifting unit that rotatably fastens the door to any one of the first rotating axis and the second rotating axis, the rotating shaft shifting unit including a first shifting unit and a second shifting unit selectively and rotatably fastening the fourth shaft to the cabinet. The fourth shaft includes a protrusion protruding toward the second shifting unit, and a fourth side flat surface is formed on the protrusion and supports the second shifting unit by establishing surface contact with the second shifting unit.

Laundry treating apparatuses include washing apparatuses having only a washing function, drying apparatuses having only a drying function, and washing-and-drying apparatuses having both the washing function and the drying function. The washing apparatus and the washing-and-drying apparatus may include a tub being provided inside a cabinet, and a drum being rotatably provided inside the tub, and the drying apparatus may include a drum being rotatably provided inside a cabinet.
Generally, an introduction port, which is configured to allow laundry to be placed therein, is formed at a front portion of a main body of the laundry treating apparatus, and a door allowing the introduction port to be opened and closed is installed in the laundry treating apparatus. Additionally, when the door faces into the front portion of the laundry treating apparatus, the door may open and close the introduction port while rotating along a horizontal direction (i.e., left-and-right direction) or a vertical direction (i.e., up-and-down direction).
A structure that can open and close the introduction port of the washing apparatus by horizontally or vertically rotating the door in accordance with a user's selection has already been disclosed earlier. This is shown, for example, in Korean Patent Application No. 10-2011-0139295.
In such opening and closing structure of the door, when a rotating shaft of the door is configured as a horizontal rotating shaft or a vertical rotating shaft, a rotating shaft shifting unit, which is provided on the door, rotatably fastens (or fixes) any one of the horizontal rotating shaft and the vertical rotating shaft, which is selected by the user.
In case the user configures the horizontal rotating shaft (i.e., in case the user intends to rotate the door along the horizontal direction), the rotating shaft shifting unit is coupled to a hinge, which is installed at a lower portion of the door, so as to rotatably support the door.
At this, a problem may occur in that the rotating shaft shifting unit (i.e., one end of the rotating shaft shifting unit) cannot bear the weight of the door and becomes bent. Additionally, a problem may also occur in that, as the opening and closing of the door is repeated, the bent state or damage of the rotating shaft shifting unit may worsen.
Additionally, multiple hinge shafts are provided on the door in order to allow the door to be rotated in multiple directions (e.g., two directions). Among the multiple hinge shafts, some of the hinge shafts shall be configured to be capable of rotatably fastening the door to a cabinet of the laundry treating apparatus in accordance with the rotating direction of the door, or some of the hinge shafts shall be configured to allow the door to be detached from the cabinet. Generally, the hinge shaft is provided on the door, and a hinge shaft detachable part configured to attach or detach the hinge shaft is provided on the cabinet.
More specifically, in accordance with the rotating direction of the door, the hinge shaft configuring a rotating shaft shall be rotatably fastened to the hinge shaft detachable part, and the hinge shaft that does not configure a rotating shaft shall be removed (or detached) from the hinge shaft detachable part.
However, in accordance with the rotating direction of the door, which is configured by the user, a problem may occur in that the hinge shaft configuring the rotating shaft may be detached from the hinge shaft detachable part during the rotation of the door.
For example, in case the user wishes to rotate the door along the vertical direction (i.e., the up-and-down direction), the hinge shaft rotating the door is horizontally provided on a lower portion of the door. For example, a total of two hinge shafts may be provided, wherein each hinge shaft may be provided on each corner area of the door at the lower portion of the door. One of such two hinge shafts shall be detached from the hinge shaft detachable part, when the door is being rotated along the horizontal direction (i.e., left-and-right direction).
However, during the rotation of the door along the horizontal direction (i.e., left-and-right direction), a problem may occur in that anyone of the two hinge shafts that are intended to rotatably fix (or fasten) the door to the cabinet may be detached from the hinge shaft detachable part during the rotation of the door. In this case, another problem may follow in that the entire door may be detached from the cabinet.


Equipment and methods for aligning the antennas of two transceivers of a point-to-point wireless millimeter wave communications link and keeping them aligned. Each of two communicating antennas is equipped with a telescopic camera connected to a processor programmed to recognize landscape images. The processors are programmed to remember the pattern of the landscape as it appears when the antennas are aligned. Each of the cameras then view the landscape periodically or continuously and if the landscape in view changes by more than a predetermined amount a signal is provided to indicate a misalignment. An operator can then take corrective action or alternatively the antenna system can be configured for remote or automatic realignment based of feedback from the camera. In a preferred embodiment, the antennas are initially aligned by substituting a narrow band oscillator power source for the signal transmitting electronics associated with a first antenna and a power detector is substituted for the signal receiving electronics of associated with a second antenna.

Wireless communications links, using portions of the electromagnetic spectrum, are well known. Most such wireless communication at least in terms of data transmitted is one way, point to multi-point, which includes commercial radio and television. However there are many examples of point-to-point wireless communication. Mobile telephone systems that have recently become very popular are examples of low-data-rate, point-to-point communication. Microwave transmitters on telephone system trunk lines are another example of prior art, point-to-point wireless communication at much higher data rates. The prior art includes a few examples of point-to-point laser communication at infrared and visible wavelengths.
The need for faster (i.e., higher volume per unit time) information transmission is growing rapidly. Today and into the foreseeable future transmission of information is and will be digital with volume measured in bits per second. To transmit a typical telephone conversation digitally utilizes about 5,000 bits per second (5 Kbits per second). Typical personal computer modems connected to the Internet operate at, for example, 56 Kbits per second. Music can be transmitted point to point in real time with good quality using mp3 technology at digital data rates of 64 Kbits per second. Video can be transmitted in real time at data rates of about 5 million bits per second (5 Mbits per second). Broadcast quality video is typically at 45 or 90 Mbps. Companies (such as telephone and cable companies) providing point-to-point communication services build trunk lines to serve as parts of communication links for their point-to-point customers. These trunk lines typically carry hundreds or thousands of messages simultaneously using multiplexing techniques. Thus, high volume trunk lines must be able to transmit in the gigabit (billion bits, Gbits, per second) range. Most modem trunk lines utilize fiber optic lines. A typical fiber optic line can carry about 2 to 10 Gbits per second and many separate fibers can be included in a trunk line so that fiber optic trunk lines can be designed and constructed to carry any volume of information desired virtually without limit. However, the construction of fiber optic trunk lines is expensive (sometimes very expensive) and the design and the construction of these lines can often take many months especially if the route is over private property or produces environmental controversy. Often the expected revenue from the potential users of a particular trunk line under consideration does not justify the cost of the fiber optic trunk line. Digital microwave communication has been available since the mid-1970""s. Service in the 18-23 GHz radio spectrum is called xe2x80x9cshort-haul microwavexe2x80x9d providing point-to-point service operating between 2 and 7 miles and supporting between four to eight T1 links (each at 1.544 Mbps). Recently, microwave systems operation in the 11 to 38 GHz band have reportedly been designed to transmit at rates up to 155 Mbps (which is a standard transmit frequency known as xe2x80x9cOC-3 Standardxe2x80x9d) using high order modulation schemes.
Bandwidth-efficient modulation schemes allow, as a general rule, transmission of data at rates of 1 to 10 bits per Hz of available bandwidth in spectral ranges including radio wave lengths to microwave wavelengths. Data transmission requirements of 1 to tens of Gbps thus would require hundreds of MHz of available bandwidth for transmission. Equitable sharing of the frequency spectrum between radio, television, telephone, emergency services, military and other services typically limits specific frequency band allocations to about 10% fractional bandwidth (i.e., range of frequencies equal to about 10% of center frequency). AM radio, at almost 100% fractional bandwidth (550 to 1650 GHz) is an anomaly; FM radio, at 20% fractional bandwidth, is also atypical compared to more recent frequency allocations, which rarely exceed 10% fractional bandwidth.
Reliability typically required for wireless data transmission is very high, consistent with that required for hardwired links including fiber optics. Typical specifications for error rates are less than one bit in ten billion (10xe2x88x9210 bit-error rates), and link availability of 99.999% (5 minutes of down time per year). This necessitates all-weather link operability, in fog and snow, and at rain rates up to 100 mm/hour in many areas.
In conjunction with the above availability requirements, weather-related attenuation limits the useful range of wireless data transmission at all wavelengths shorter than the very long radio waves. Typical ranges in a heavy rainstorm for optical links (i.e., laser communication links) are 100 meters and for microwave links, 10,000 meters.
Atmospheric attenuation of electromagnetic radiation increases generally with frequency in the microwave and millimeter-wave bands. However, excitation of rotational transitions in oxygen and water vapor molecules absorbs radiation preferentially in bands near 60 and 118 GHz (oxygen) and near 23 and 183 GHz (water vapor). Rain, which attenuates through large-angle scattering, increases monotonically with frequency from 3 to nearly 200 GHz. At the higher, millimeter-wave frequencies, (i.e., 30 GHz to 300 GHz corresponding to wavelengths of 1.0 millimeter to 1.0 centimeter) where available bandwidth is highest, rain attenuation in very bad weather limits reliable wireless link performance to distances of 1 mile or less. At microwave frequencies near and below 10 GHz, link distances to 10 miles can be achieved even in heavy rain with high reliability, but the available bandwidth is much lower.
High frequency, large antennas are typically designed to produce very narrow beams which must be very accurately aligned. Because of the narrow beams, both transmit and receive antennas must be precisely pointed at each other. Gimbals for these antennas are typically designed with two pointing angles; therefore, the process of aligning two antennas is essentially a 4 dimensional search. Since the antennas of the instant invention (such as a four-foot diameter antenna) can have narrow beams in the range of 0.15 degrees or less and are capable of thousands of discrete positions in each dimension, there are an extremely large number of four-dimensional alignments over which to search. As will be shown below, a complete search of this four-dimensional space could theoretically consume many years.
Therefore, what is needed are equipment and methods for aligning a wireless data link having very narrow beam widths and keeping them aligned.
The present invention provides equipment and methods for aligning the antennas of a point-to-point wireless millimeter wave communications link and keeping them aligned. Each of two communicating antennas is equipped with a telescopic camera connected to a processor programmed to recognize landscape images. The processors are programmed to remember the pattern of the landscape as it appears when the antennas are aligned. Each of the cameras then view the landscape periodically or continuously and if the landscape in view changes by more than a predetermined amount a signal is provided to indicate a misalignment. An operator can then take corrective action or alternatively the antenna system can be configured for remote or automatic realignment based of feedback from the camera. In a preferred embodiment, the antennas are initially aligned by substituting a narrow band oscillator power source for the signal transmitting electronics associated with a first antenna and a power detector is substituted for the signal receiving electronics of associated with a second antenna. In preferred embodiments after a first alignment procedure is performed, the procedure is repeated with an oscillator power source connected to the second antenna and a power detector connected to the first antenna. In other preferred embodiments the antennas are pre-aligned using a signaling mirror, a narrow beam searchlight, or laser. After the antennas are aligned the transceiver electronics are reconnected. In preferred embodiments the communication link operates within the 92 to 95 GHz portion of the millimeter spectrum and provides data transmission rates in excess of 155 Mbps. A first transceiver transmits at a first bandwidth and receives at a second bandwidth both within the above spectral range. A second transceiver transmits at the second bandwidth and receives at the first bandwidth. The transceivers are equipped with antennas providing beam divergence small enough to ensure efficient spatial and directional partitioning of the data channels so that an almost unlimited number of transceivers will be able to simultaneously use the same spectrum. Antennas and rigid support towers are described to maintain beam directional stability to less than one-half the half-power beam width. In a preferred embodiment the first and second spectral ranges are 92.3-93.2 GHz and 94.1-95.0 GHz and the half power beam width is about 0.15 degrees or less.

Narrow beamwidth communication link with alignment camera


A technique for quantifying the effect of plasma/etching during the formation of MOS transistors avoids the problems of prior techniques. A modified MOS capacitor 40 comprising a dielectric 12 separating a conductive plate 18 having a conductive sidewall 24 from a conductive substrate 10 is formed using the same or similar steps as a MOS transistor. Dielectric layer 12, such as oxide, is formed over a portion of conductive substrate 10. Conductive capacitor plate 18 is formed over a portion of the dielectric layer 12 using a plasma etch to remove unwanted material. After forming capacitor plate 18, the area of capacitor plate 18 is modified to encompass a peripheral oxide region 20. The modification consists of placing a conductive sidewall 24 of the same material as capacitor plate 18 or of other conductive materials around the periphery of capacitor plate 18. Electrical characterization is performed on modified MOS capacitor 40 yielding information about damage to the oxide in peripheral region 24 caused by the plasma etch. Modified MOS capacitor 40 can be used to compare plasma chemistries, detect oxide trenching, detect etchant loading and determine the effect of process hardware changes, for example. It can especially account for oxide loss in tight geometry features and in regimes where optical measurement techniques are unreliable.

1. Field of the Invention
This invention relates to semiconductor integrated circuits and more specifically relates to quantifying the effect of plasma etching on, and during the formation of, MOS devices.
2. Brief Description of the Prior Art
During the manufacture of an integrated circuit, layers of material are formed by deposition on a substrate and then etchants are used to remove unwanted portions of each layer. The material layers may be deposited by sputtering, evaporation or growth, and the etchant may be a liquid or a plasma. Typically, the deposition and etch steps are selectively repeated successively to form transistors, interconnections, and other selected components of the integrated circuit. While a layer is being etched, an underlying, previously deposited layer may be damaged or otherwise deleteriously affected.
An MOS transistor, formed as described above, may comprise a thin gate oxide separating and insulating a conductive gate from a semiconductive channel region. Damage to the gate oxide layer during plasma etch of the gate may cause a voltage breakdown in the gate oxide when the MOS transistor is operated. Several techniques have been used to attempt to detect damage to oxide layers using devices such as Schottky barriers, capacitors and transistors. However, none of these techniques directly addresses detection of damage to the oxide at the periphery of a MOS transistor gate.
The primary damage caused by etching a conductive layer to form the gate is usually weakened gate dielectric at the periphery of the gate, oxide thinning over wider areas of the gate oxide beyond the periphery of the gate, and "trenching" of the gate oxide at the periphery of the gate or in areas beyond the periphery of the gate. Microtrenches are formed when the etching process removes all of the oxide from a small area or "punches through" the oxide to expose the silicon substrate. The process engineer is interested in detecting and minimizing damage to the gate oxide in order to improve reliability and performance of the MOS device.
Currently, the process engineer has limited means to detect damage to gate oxide layers, such as (a) breakdown measurements on blanket wafers (unpatterned wafers) to detect damage to the oxide layer resulting from general exposure to the etchant, (b) optical photometry measurements of surface index of refraction to detect damage to the oxide layer in patterned wafers, and (c) electron microscopy (SEM/TEM) cross sections to visually determine trenching. Breakdown measurements on a blanket wafer determine if damage to the oxide has occurred anywhere on the wafer, but does not specifically evaluate damage around the edges of an etched structure. Photometry measures the surface index of refraction, and damage to the oxide layer may be inferred from the results, but areas between device structures cannot be adequately resolved. Electron microscopy requires cross-sectioning the integrated circuit, so only damage to the oxide located along the cross-section will be detected. These techniques provide, at best, rough damage estimates and are inadequate for evaluating advanced small geometry processes due to a general lack of sensitivity and an inability to resolve areas between tightly spaced devices, in the case of photometry. Additionally, they are of little use for monitoring a production process since they require special test wafers or rely on destructive testing of a wafer.
It is accordingly a goal of the present invention to provide a means for detecting damage to gate oxide due to plasma etching that is applicable to the evaluation of new processes for forming small geometry integrated circuits as well as to processes which are currently being used for production of integrated circuits.
Other goals and advantages will be apparent to those of ordinary skill in the art having reference to the following figures and specification.

Apparatus and method for detecting defects in insulative layers of MOS active devices