A pair of CMOS image sensors is provided. One of the pair of CMOS image sensors is assigned as a master CMOS image sensor and the other is assigned as a slave CMOS image sensor. The slave CMOS image sensor is synchronized to the master CMOS image sensor during image data acquisition. In one embodiment, the master CMOS image sensor and the slave CMOS image sensor are connected to receive a control signal, which assigns the master CMOS image sensor as master and the slave CMOS image sensor as slave. In another embodiment, the master CMOS image sensor and slave CMOS image sensor are hardwired to assign the master and slave. In yet another embodiment, the data signals from the master CMOS image sensor and slave CMOS image sensor are interleaved.

Stereo imaging uses planar imagers to acquire three-dimensional information about a scene. To obtain the third dimension of depth, two planar imagers are offset by a distance to determine the relative position of objects in the scene. Two types of stereo cameras using conventional cameras with photochemical film as the imager are available. In one, a special offset optics system is used to create two images on a single frame of film by opening a single shutter. In the other, two independent offset cameras with coordinated shutters are used to simultaneously expose two frames of film. Conventional cameras present certain problems as stereo cameras, however. They are complicated, expensive mechanical devices and photochemical film requires the images to be developed and converted to digital data.
The development of charge-coupled device (CCD) image sensors has led to their use in stereo cameras. A CCD image sensor comprises a two-dimensional array of photodiodes which convert received light into a charge. For stereo imaging, two CCD image sensors offset by a distance collect two images using global electronic shutters to synchronize the images. The electronic image data is then read out sequentially. CCD image sensors are expensive in themselves and less than ideal for this application. CCD image sensors require substantial off-chip support circuitry, such as power supplies, device drivers, timing generation, and analog to digital conversion. In addition, CCD image sensors use large amounts of power, requiring large battery capacity in battery-powered devices. This makes CCD-based stereo cameras complicated and expensive.
It would be desirable to have a stereo imaging system and method of using the same that would overcome the above disadvantages.

Avago Technologies Sensor IP (Singapore) Pte. Ltd


A compound has the formula

Camptothecins are DNA topoisomerase I inhibitors now being used as anticancer drugs. Topotecan (tpt) and CPT-11 are the first two members in the camptothecin family to gain Food and Drug Administration full approval status (topotecan in 1996 as second-line therapy for advanced epithelial ovarian cancer, topotecan again in 1998 for the treatment of small cell lung cancer, CPT-11 in 1998 as first-line therapy for colon cancer). Several other analogs of the camptothecin family such as GI-147211C, DX8951f, 9-aminocamptothecin (9-AC) and 9-nitrocamptothecin are in various stages of pre-clinical and clinical evaluation. Each of the campothecins in clinical use undergoes relatively rapid hydrolysis in the bloodsteam resulting in a marked loss of anticancer activity. It is the key α-hydroxylactone pharmacophore within clinically relevant camptothecins that hydrolyzes at physiological pH to yield a biologically-inactive and potentially toxic hydroxy carboxylate form. Fassberg, J. and Stella, V. J., "A Kinetic and Mechanistic Study of the Hydrolysis of Camptothecin and Some Analogues", J. Pharm. Sci. 81: 676–684 (1992); Hertzberg, R. P., Caranfa, M. J., and Hecht, S. M., "On the Mechanism of Topoisomerase I Inhibition by Camptothecin: Evidence for Binding to an Enzyme-DNA Complex", Biochemistry 28: 4629–4638 (1989); Hsiang, Y-H., and Liu, L. F., "Identification of Mammalian DNA Topoisomerase I as an Intracellular Target of the Anticancer Drug Camptothecin", Cancer Res. 48: 1722–1726 (1988); and Jaxel, C., Kohn, K. W., Wani, M. C., Wall, M. E., and Pommier, Y., "Structure-Activity Study of Camptothecin Derivatives on Mammalian Topoisomerase I: Evidence for a Specific Receptor Site and a Relation to Antitumor Activity", Cancer Res. 49: 5077–5082 (1989). References set forth herein, including those set forth above, may facilitate understanding of the present invention. Inclusion of a reference herein is not intended to an does no constitute an admission that the reference is prior art with respect to the present invention.
The structures of camptothecin and some of its important analogs are shown below:

Recent research efforts have shown that agents such as 9-aminocamptothecin and camptothecin (cpt) display very poor stabilities in human blood due to high affinity binding interactions between their carboxylate forms and human serum albumin (HSA). Burke, T. G, Mi, Z., Jiang, Y., and Munshi, C. B. "The Important Role of Albumin in Determining the Relative Human Blood Stabilities of the Camptothecin Anticancer Drugs", Journal of Pharmaceutical Sciences, 84: 518–519 (1995); Burke, T. G. and Mi, Z. "The Structural Basis of Camptothecin Interactions with Human Serum Albumin: Impact on Drug Stability", Journal of Medicinal Chemistry, 37: 40–46 (1994); Mi, Z. and Burke, T. G., "Differential interactions of Camptothecin Lactone and Carboxylate Forms with Human Blood Components", Biochemistry, 33: 10325–10336 (1994); and Mi, Z., Malak, H., and Burke, T. G. "Reduced Albumin Binding Promotes the Stability and Activity of Topotecan in Human Blood", Biochemistry, 34: 13722–13728 (1995), the disclosures of which are incorporated herein by reference. Frequency-domain lifetime fluorometry experiments revealed that human serum albumin (HSA) preferentially binds camptothecin carboxylate with over a 100-fold higher affinity compared to camptothecin lactone. Mi, Z. and Burke, T. G. "Marked Interspecies Variations Concerning the Interactions of Camptothecin with Serum Albumins: A Frequency-Domain Fluorescence Spectroscopic Study", Biochemistry, 33: 12540–12545 (1994), the disclosure of which is incorporated herein by reference. This differential binding of carboxylate over lactone results in camptothecin and 9-AC opening more rapidly and completely in the presence of HSA than in the absence of the protein. In human plasma, pH 7.4 and 37° C., camptothecin and 9-AC both open rapidly and essentially completely to almost negligible 0.2% lactone levels at equilibrium. While the presence of HSA promotes lactone ring opening for camptothecin and 9-AC, red blood cells and lipid bilayers in general preferentially bind the electroneutral lactone forms of camptothecins over their respective negatively-charged carboxylate lactone forms. Burke, T. G., Staubus, A. E., Mishra, A. K., and Malak, H., "Liposomal Stabilization of Camptothecin's Lactone Ring", J. Am. Chem. Soc. 114: 8318–8319 (1992); and Burke, T. G., Mishra, A. K., Wani, M., and Wall, M., "Lipid Bilayer Partitioning and Stability of Camptothecin Drugs", Biochemistry, 32: 5352–5364 (1993), the disclosures of which are incorporated herein by reference. Drug interactions with erythrocytes thereby promote active lactone levels in blood.

Camptothecin analogs and methods of preparation thereof

Abstract: A compound has the formula

Abstract: in racemic form, enantiomerically enriched form or enantiomerically pure form. R6 is preferably —Si(R8R9R10) or —(R7)Si(R8R9R10), wherein R7 is an alkylene group, an alkenylene group, or an alkynylene group; and R8, R9 and R10 are independently a C1-10 alkyl group, a C2-10 alkenyl group, a C2-10 alkynyl group, an aryl group or a —(CH2)NR11 group, wherein N is an integer within the range of 1 through 10 and R11 is a hydroxy group, alkoxy group, an amino group, an alkylamino group, a dialkylamino group, a halogen atom, a cyano group, —SRc or a nitro group. R1–R4 can be broadly substituted. R5 is preferably a C1-10 alkyl group, an alkenyl group, an alkynyl group, or a benzyl group. R13 is preferably H, F or —CH3. R16 is R16 is —C(O)Rf or H. The E-ring (the lactone ring) may be opened. A method of synthesis of compound (1) and intermediates in the synthesis thereof are provided.


The invention relates to a method for controlling the lean operation of an internal combustion engine, especially an internal combustion engine of a motor vehicle, provided with a nitrogen oxide storage catalyst. As claimed in the invention, in a first process step, to establish the instant of switching from the storage phase to the discharge phase, a switching operating point is determined at least from the integral value of the nitrogen oxide mass flow upstream and/or downstream of the storage catalyst. The respective switching operating point is compared in a second process step to a definable operating field which is optimized especially with respect to the fuel savings potential as a function of the load acceptance of the internal combustion engine, which is formed by a plurality of individual operating points for one new and one aged storage catalyst, for a switching operating point which is located within the operating field the engine control enabling lean operation and thus switching between the storage phase and the discharge phase of the nitrogen oxide storage catalyst, while the engine control dictates lambda operation of the internal combustion engine at which lambda is equal to 1 for a switching operating point which departs from the definable operating field.

The invention relates to a method for controlling the lean operation of an internal combustion engine, especially an internal combustion engine of a motor vehicle, provided with a nitrogen oxide storage catalyst.
In current automotive engineering, spark ignition engines as internal combustion engines with direct gasoline injection instead of conventional intake pipe injection are preferred, since these internal combustion engines compared to conventional spark ignition engines have distinctly more dynamics, are superior with respect to torque and power, and at the same time facilitate a reduction of fuel consumption by up to 15%. This is made possible mainly by so-called stratified charging in the partial load range in which only in the area of the spark plug an ignitable mixture is necessary, while the remaining combustion space is filled with air. As a result, the engine can be operated unchoked; this leads to reduced charge changes. In addition, the direct gasoline injector benefits from reduced heat losses, since the air layers around the mixture cloud are insulated toward the cylinder and the cylinder head. Since conventional internal combustion engines, which work according to the intake manifold principle, can no longer be ignited at such a high air excess as is present in direct gasoline injection, in this stratified charging mode the fuel mixture is concentrated around the spark plug which is positioned centrally in the combustion space, while in the edge areas of the combustion space there is pure air. In order to be able to concentrate the fuel mixture around the central spark plug which is positioned in the combustion space, a concerted air flow in the combustion space is necessary, a so-called tumble flow. In the process, an intense, roller-shaped flow is formed in the combustion space and the fuel is injected only in the last third of the upward motion of the piston. By the combination of a concerted air flow and special geometry of the piston, which for example has for example a pronounced fuel and flow depression, the especially finely dispersed fuel is concentrated in a so-called "mixture ball" ideally around the spark plug and ignites reliably. The engine control provides for the respectively optimized adaptation of the injection parameters (point of injection time, fuel pressure).
These internal combustion engines can therefore be operated in lean operation for a correspondingly long time; this benefits fuel consumption overall, as has been described in the foregoing. This lean operation however entails the disadvantage that the nitrogen oxides (NOx) in lean exhaust cannot be reduced by a 3-way catalyst. In order to keep the nitrogen oxide emissions within the scope of prescribed limits, for example of the Euro-IV limit value, nitrogen oxide storage catalysts are generally used in conjunction with these internal combustion engines. These nitrogen oxide storage catalysts are operated such that the nitrogen oxides produced by the internal combustion engine in a first phase of operation as the lean operating phase are stored in the nitrogen oxide storage catalyst. This first operating phase or lean operating phase of the nitrogen oxide storage catalyst is also called the storage phase. As the length of the storage phase increases, the efficiency of the nitrogen oxide storage catalyst decreases; this leads to an increase of nitrogen oxide emissions downstream of the nitrogen oxide storage catalyst. The reduction in efficiency is caused by the increase in the nitrogen oxide fill level of the nitrogen oxide storage catalyst. The rise in nitrogen oxide emissions downstream of the nitrogen oxide storage catalyst can be monitored and after a definable threshold value is exceeded, a second operating phase of the nitrogen oxide storage catalyst, a so-called discharge phase, can be initiated. During this second operating phase, in the exhaust of the internal combustion engine a reducing agent is added which reduces the stored nitrogen oxides to nitrogen and oxygen. The reducing agent is generally a hydrocarbon (HC) and/or carbon monoxide (CO) which can be produced in the exhaust gas simply by a rich setting of the fuel/air mixture. Towards the end of the discharge phase, most of the stored nitrogen oxide is reduced and less and less of the reducing agent meets the nitrogen oxide which it can reduce to oxygen and nitrogen. Towards the end of the discharge phase the proportion of the reducing agent in the exhaust gas downstream of the nitrogen oxide storage catalyst therefore rises. By corresponding analysis of the exhaust downstream of the nitrogen oxide storage catalyst, for example by means of an oxygen sensor, the end of the discharge phase can then be initiated and it becomes possible to switch again to the lean operation phase. In the disclosed nitrogen oxide storage catalysts this switching is carried out at time intervals of for example 30 to 60 seconds, the regeneration, i.e., the discharge phase, lasting approximately 2 to 4 seconds.
The problem however is that in nitrogen oxide storage catalysts with increasing service life the storage capacity for nitrogen oxides decreases. This is due to the fact that mainly the sulfur contained in fuels leads to poisoning of the storage catalyst, i.e., to permanent deposition of sulfur in the storage catalyst which reduces the storage capacity for nitrogen oxides. The nitrogen oxides are stored in nitrogen oxide storage catalysts in the form of nitrates, while sulfur is stored in the form of sulfates. Since sulfates are chemically more stable than nitrates, the sulfate cannot decompose in nitrogen oxide regeneration. Only at catalyst temperatures above 650° C. under reducing conditions can sulfur be discharged. Such high catalyst temperatures are generally not reached however, especially in city traffic.
The generic WO 02/14658 A1 discloses a process for controlling lean operation of an internal combustion engine having a nitrogen oxide storage catalyst, in which the nitrogen oxides produced by the internal combustion engine in a first operating phase (lean operation) as the storage phase are stored for a specific storage time in the nitrogen oxide storage catalyst, and in which after the storage time expires, by a control device as the engine control at a specific switching instant for a specific discharge time switching to a second operating phase (rich operation) takes place as the discharge phase in which the nitrogen oxides which have been stored during the storage time are discharged from the nitrogen oxide storage catalyst. Furthermore, the nitrogen oxide mass flow upstream of the nitrogen oxide storage catalyst and/or the nitrogen oxide mass flow downstream of the nitrogen oxide storage catalyst are each integrated over the same time interval.
Specifically, here these integral values are put into a relative relationship to one another. Thus, in this process a quality factor will be determined which renders possible a conclusion about the storage capacity of the nitrogen oxide storage catalyst with respect to ageing of the catalyst by sulfur poisoning and thermal damage or the age-induced decrease of the storage capacity. In particular, in this process the degree of poisoning of the catalyst with sulfur will be determined and thus the sulfur content in the control device of the internal combustion engine will be corrected in order to optimize sulfur regeneration. By integration over the time interval, the effects of fluctuations and disruptions on the determined nitrogen oxide mass flow values will be reduced since, viewed over a specific time interval, a type of average value of the quality factor is obtained which will be more conclusive than the individual instantaneous values obtained at specific times. But in practical operation for nitrogen oxide storage catalysts in general such complex operating conditions prevail that the quality factor, in spite of the reference to a specific time interval, under certain circumstances does not adequately reproduce the actual state of the storage capacity of the nitrogen oxide storage catalyst. This can on the one hand have an adverse effect on fuel consumption, since for example a rich mixture is supplied too early. On the other hand, there is the danger that the savings potential by lean operation is so low that only a small advantage in fuel consumption can be gained. Since lean operation however leads to high nitrogen oxide emissions, in certain operating ranges the advantage in fuel consumption is not in a favorable ratio to the actual nitrogen oxide emissions. Discharge itself in this procedure will only take place when the modeled, stored nitrogen oxide mass has exceeded a specific boundary value.
Furthermore, in conjunction with operation of the nitrogen oxide storage catalyst, consideration of ageing, especially the ageing of sulfur poisoning, in the design of a nitrogen oxide storage catalyst is to be taken into consideration in order to ensure that the ageing of the catalyst over the intended service life of the catalyst leads to adherence to given exhaust boundary values with respect to nitrogen oxide emissions in an aged nitrogen oxide storage catalyst. In this respect, adapting the number of discharges to the amount of nitrogen oxide discharged per charging and discharging cycle is generally known such that at a storage capacity of the aged nitrogen oxide storage catalyst which has been reduced relative to a new nitrogen oxide storage catalyst the amount of nitrogen oxide released during the exhaust gas test time interval does not exceed the given exhaust boundary value. This amount of nitrogen oxide which is released per charging cycle for an aged storage catalyst is an absolute quantity and constitutes the absolute nitrogen oxide slip, i.e., that as soon as the storage catalyst is charged with this amount of nitrogen oxide, discharge takes place. This absolute nitrogen oxide slip as an established value applies both to the new and also the aged nitrogen oxide storage catalyst. Since a rich mixture of lambda quantity 1 is required per discharge, with an increasing number of discharges in the course of ageing of a storage catalyst the fuel consumption also rises compared to that of a new storage catalyst.

Method for controlling the lean operation of an internal combustion engine, especially an internal combustion engine of a motor vehicle, provided with a NOx storage catalyst


This disclosure describes, in part, systems and techniques for performing eye tracking. For instance, a system may include a first imaging device that generates first image data. The system may then analyze the first image data to determine a location of a face of a user. Using the location, the system may cause an actuator to move from a first position to a second position in order to direct a second imaging device towards the face of the user. While in the second position, the second imaging device may generate second image data representing at least the face of the user. The system may then analyze the second image data to determine a gaze direction of the user. In some instances, the first imaging device may include a first field of view (FOV) that is greater than a second FOV of the second imaging device.

Many systems use eye tracking in order to determine gaze directions of users. For instance, such as in vehicles, a system may use a camera installed in a vehicle to capture images of users located within the vehicle. The system may then analyze the images to determine at least the gaze direction of the user driving the vehicle. A vehicle control system may then use the gaze direction to determine if the user is paying attention to the road while driving the vehicle. If the user is not paying attention to the road, the vehicle control system may output a sound or other alert to the user.
In many situations, these systems have problems performing eye tracking to determine the gaze direction of the user. For example, such as in large environments like the passenger compartments of vehicles, the camera may require a wide-angle lens to capture images that represent the environment. As such, only a small portion of the images may represent the eyes of the user, which can cause problems for the system analyzing the images using eye tracking. For instance, the system may be unable to identify the eyes of the user using the images. To compensate for this problem, some systems use high-resolution cameras to capture the images. However, using high-resolution cameras may increase processing load, which may increase latency, power consumption, and/or heat generated by the system.

System for performing eye detection and/or tracking


A side plate of a casing includes bracket members and a surface member. Each of the bracket members includes three second coupling portions and a plate-shaped attachment portion provided integrally with the second coupling portions. A coupling pin is inserted into the second coupling portions. The surface member is joined to the plate-shaped attachment portion. The bracket member includes a step fitted to an end of the surface member. The plate-shaped attachment portion and the surface member are jointed at a spot welding section including spots in a zigzag pattern.

1. Field of the Invention
The present invention relates to a fuel cell stack including a box-shaped casing and a stack body provided in the casing. The stack body is formed by stacking a plurality of unit cells. Each of the unit cells includes an electrolyte electrode assembly and separators sandwiching the electrolyte electrode assembly. The electrolyte electrode assembly includes a pair of electrodes, and an electrolyte interposed between the electrodes.
2. Description of the Related Art
For example, a solid polymer fuel cell employs a membrane electrode assembly which includes an anode, a cathode, and an electrolyte membrane (electrolyte) interposed between the anode and the cathode. The electrolyte membrane is a polymer ion exchange membrane. The membrane electrode assembly and separators sandwiching the membrane electrode assembly make up a unit of a fuel cell (unit cell) for generating electricity.
In the fuel cell, a fuel gas such as a gas chiefly containing hydrogen (hereinafter also referred to as the "hydrogen-containing gas") is supplied to the anode. A gas chiefly containing oxygen or air (hereinafter also referred to as the "oxygen-containing gas") is supplied to the cathode. The catalyst of the anode induces a chemical reaction of the fuel gas to split the hydrogen molecule into hydrogen ions and electrons. The hydrogen ions move toward the cathode through the electrolyte membrane, and the electrons flow through an external circuit to the cathode, creating a DC electrical energy.
Generally, a predetermined number of, e.g., several tens to several hundreds of fuel cells are stacked together to form a fuel cell stack for achieving the desired level of electricity in power generation. Components of the fuel cell stack need to be tightened together reliably under pressure so that the internal resistance of the fuel cell does not increase, and the sealing performance for preventing leakage of reactant gases is maintained.
In this regard, for example, a fuel cell stack disclosed in Japanese Laid-Open Patent Publication No. 2002-298901 is known. The fuel cell stack includes a stack body formed by stacking a predetermined number of unit cells. Current collecting electrodes (terminal plates) are provided outside the stack body. Further, end plates are stacked on the outside of the terminal plates. The end plates are joined to the casing by hinge mechanisms. The casing includes a plurality of panels (side plates) provided on upper, lower, left, and right sides between the end plates.
Thus, in the conventional technique, the number of components is reduced effectively, and it is possible to use thin end plates. It is possible to reduce the size and the weight of the entire fuel cell stack easily.
In the conventional technique, for example, as shown in FIG. 7, at longitudinal opposite ends of a panel 1 of the casing, a plurality of cylindrical insertion portions 4a to 4c are provided. Coupling pins 3 of hinge mechanisms 2 are inserted in the insertion portions 4a to 4c at the opposite ends of the panel 1. At this time, typically, the insertion portions 4a to 4c are joined to the opposite ends of a surface member 5 of the panel 1 by laser welding or the like.
However, since the insertion portions 4a to 4c are joined to the ends of the surface member 5 individually, it is considerably difficult to form insertion holes 6a to 6c of the insertion portions 4a to 4c coaxially, i.e., in alignment with each other. If the insertion holes 6a to 6c are not in alignment with each other, the coupling pin 3 cannot be inserted into the insertion holes 6a to 6c. Thus, the assembling operation of the hinge mechanism 2 cannot be performed efficiently. Further, when a load is applied to the casing, a bending moment is applied to the panel 1, and the strength of the hinge mechanism 2 is lowered.

This patent is subject to a terminal disclaimer.


The present invention is directed to a method of detecting a neurodegenerative disease in a mammal by activating brain tissue of the mammal by application of radiation under conditions effective to promote a simultaneous multiphoton excitation of the brain tissue and to emit a fluorescence characteristic. The fluorescence characteristic is then compared to a standard fluorescence emitted by exciting healthy brain tissue of the mammal under the same conditions used to carry out the activating step. Brain tissue where the fluorescence characteristic differs from the standard fluorescence is identified as potentially having a neurodegenerative disease. Another aspect of the present invention is directed to a method of producing an image of brain tissue from a mammal by activating brain tissue of a mammal with radiation applied under conditions effective to promote a simultaneous multiphoton excitation of the brain tissue and to produce fluorescence. The fluorescence is then collected to produce an image of the brain tissue.

Alzheimer's Disease is a devastating illness affecting nearly 4 million Americans, costing the country billions of dollars in direct care, lost income, and—most importantly—costing untold anguish for millions of American families.
The disease symptoms start insidiously, with relatively non-specific signs and symptoms. Subtle memory loss, occasional word-finding difficulties, irritability and aggressiveness can all be signs of a disease process from a clinical perspective, that has already affected the brain substantially. Over the course of several years, the disease progresses to profound amnesia to the point where patients do not know themselves, or their family. Frequently this amnesia is accompanied by frustration and paranoia. Ultimately patients lose all ability to care for themselves—to dress themselves, to bathe, even to control their bowel and bladder. Their last years are frequently spent in a nursing home. As the average age of the population grows, the number of Alzheimer patients will explode because it is a strongly age-related illness.
While these clinical symptoms are going on, the changes in the brain are marked. By the time the very first clinical symptoms appear, there are innumerable microscopic deposits of a protein called amyloid ("A-beta" or "Aβ"), as well as changes in the brain cells themselves. As the disease progresses, the brain shrinks and losses as many as 50% of its cells.
Genetic risk factor analysis and molecular biology suggest strongly that it is the depositon of Aβ that is the critical aspect of this disease process. Seeing Aβ and neuronal change, neurofibrillary tangles, in the brain under the microscope provides a definitive diagnosis to a neuropathologist. However, these changes are far too small (100 times too small) to be seen by even the most sophisticated clinical imaging devices such as computerized tomography or magnetic resonance imaging.
The ability to detect amyloid deposition and neurofibrillary changes in neurons in vivo would provide a definitive diagnostic test for Alzheimer's Disease, and compares to quite non-specific clinical symptoms at the beginning of the disease process. Moreover, the ability to visualize and quantitate these changes would provide a definitive means of tracking progression of disease, and effectiveness of potential therapeutics.
The present invention is directed to overcoming the deficiencies in the prior art by providing a method of diagnostically detecting and imaging Alzheimer's Disease and other neurodegenerative diseases.

In vivo multiphoton diagnostic detection and imaging of a neurodegenerative disease


An adjustable trigger pressure archery release including a bayonet mounted trigger utilizing an actuator ramp to reduce trigger travel. The caliper jaws and cam profile combine to create an automatic closing action to close the release, whereby rearward pulling or squeezing movement of the trigger engages the caliper jaws to an open bow string or string loop apparatus receiving condition, and relaxing or releasing movement of the trigger closes the caliper jaws into a string retaining position. The release includes an independent mechanism for permitting adjustment of the trigger pressure force, without affecting trigger travel including frictional means of maintaining selected setting. The release head is universally adjustable or lockable relative to a wrist strap or similar mounting.

The present invention relates to a caliper-type bow string release for archery. Such bow string releases are used by the user applying his trigger finger to apply pressure to pull the trigger, opening the jaws for loading and relaxing tension on trigger, closing the jaws around the bowstring. Such systems allow the archer to maintain one grasping finger-hand position to load and fire release. Even though many previous styles of releases can be manipulated to load on to a bowstring, it can be awkward at best. For example, earlier releases do not rotate nor allow the user to adjust the actual trigger pressure force required to fire the release.
Archery enthusiasts have never had a release available that features caliper jaws with 360-degree selectable rotation, provided by sealed ball bearings. This rotation should be in front of the trigger, which eliminates the possibility of torque being applied to the bowstring and allows for unlimited hand anchoring options that are impossible with non-rotating releases. There is also a need for the ability to easily adjust without tools the trigger pressure force required in firing the release, which is completely independent from affecting trigger travel and does not aid in the closing of the locking mechanism. These features should be combined with affordability, accuracy, ease of use, and reliability. The release must be adaptable to any style of shooting, and must be easily loaded on to a string loop or similar device. The jaws of the release should be very small in profile. This enables it to be used on all rigid center-nocking devices without having to trim arrow nocks to use them. The caliper jaws should open widely to easily load directly on to a bowstring.
Earlier U.S. patents show devices with some similarities but also several deficiencies. Examples are U.S. Pat. Nos. 5,417,197; 5,564,407; 5,582,158. The Classic Caliper has automatic latching features. The present invention has no such feature or means to accomplish that but is loaded manually by actuating the trigger. These patents disclose a push-pull, rocking mode of trigger operation to fire the release. In contrast, the present invention employs a trigger utilizing a novel ramped trigger actuator to increase the throw of the sear components with minimum input from the trigger. This decreases trigger travel necessary to fire and gives the release the quick on the edge feel the shooters crave with very low trigger pressure required to fire the release.
Earlier designs disclose a cam actuator moveable between the jaws mounted on a stem, designed to maintain the jaws in a latched open condition. The cam actuator of the present invention is designed to do the opposite, that is, to close the jaws automatically. These designs include a cam and jaw that were designed having surfaces that define trigger force adjustment. These surfaces are sear elements relying on complex cam surfaces, contact angles and positional relationships to increase or decrease sliding frictional forces seen at the trigger. This repositioning of sear elements requires precise minuscule adjustments, being careful not to make large unwanted changes in trigger pressure force. This changing of sear element positions also allows the user to set the device into an unsafe condition mistakenly while trying to adjust trigger pressure forces. These changes are made by locating a small socket set screw installed in cylindrical member, insertion of a small hex wrench loosening socket set screw while maintaining the wrench in the socket of the set screw and rotating the head and jaws to new setting, tightening the set screw to complete adjustment, and hoping you have not turned anything in a wrong direction. Additionally these earlier designs do not allow the user to preview the trigger pressures force settings selected: one must simulate loading and firing the mechanism.
The present invention has separated the trigger pressure force adjustment means from the sear components. The user may now preview their setting by simple trigger pulling action. This design does not require one to simulate loading and firing the mechanism. Since sear components are not adjusted to achieve varied trigger pressure forces, the present invention cannot be adjusted into an unsafe condition by manipulating this mechanism. The design of the present invention provides the means to adjust trigger pressure by rotation of a dial with a minimum of two fingers, and this may be done with the same hand the release is installed on (shooting hand).

Adjustable trigger pressure archery release (stealth)


A caller ID call-back device that allows a user to automatically place telephone calls to selected directory numbers using several dialing plans. A user may select a dialing plan by selecting a first, second, or third dialing plan selection device. Selection of each dialing plan selection device causes the caller ID call-back device to automatically dial a received caller ID directory number using a particular dialing plan. The dialing plans typically include the last seven digits of the received directory number, all ten digits of the received directory number, and one plus all ten digits of the received directory number. The caller ID call-back device may also include a memory call-back selection device for automatically dialing a received caller ID directory number in accordance with a dialing plan indicator that was previously saved in association with the directory number. After the user selects a dialing plan to automatically place a telephone call to a received caller ID directory number, the caller ID call-back device may prompt the user the save the selected dialing plan in association with the received directory number. The user may also save other dialing plans in association with a stored directory number, such as an account code or a calling card code, which the caller ID call-back device automatically dials before dialing the associated directory number.

The North America Numbering Plan (NANP) specifies a 10-digit format for directory numbers, which are more commonly referred to as telephone numbers. The NANP is an integrated plan for assigning directory numbers throughout the United States (including Puerto Rico and the U.S. Virgin Islands), Canada, Bermuda, Anguilla, Antigua, Bahamas, Barbados, British Virgin Islands, Cayamn Islands, Dominica, Dominican Republic, Grenada, Jamacia, Monteserrat, St. Kitts & Nevis, St. Lucia, St. Vincent, Turks & Cicos Islands, and Trinidad & Tobago.
A directory number is typically designated as NPA-NXX-XXXX, where the first three digits are the Numbering Plan Area (NPA) code, which is more commonly referred to as the area code. The next seven digits, designated as NXX-XXXX, are a terminating destination code. The first three digits of the terminating destination code, designated as NXX, are the central office code, also called the prefix or exchange. The last four digits of the terminating destination code, designated as XXXX, are a line, station, or subscriber code. The digits designated as "N" may be any number 2 through 9 and the digits designated as "X" may be any number 0 through 9.
In the NANP as originally implemented, area codes were limited to the format NO/1X. That is, the first digit of the area code could be any number 2 through 9, the second digit of the area code could be either a 1 or a 0, and the third digit of the area code could be any number 0 through 9. This NO/1X format, which provided for a maximum of 160 area codes, was changed as of Jan. 1, 1995 due to a projected shortage of area codes. The new area code format, NXX, allows the second digit of the area code to be any number 0 through 9. The new area code format increased the number of permissible area codes by 640, to a total of 800 available area codes. For more information relating to the NANP, see the 1996 annual status report to the industry on Numbering Plan Area (NPA) codes, published on Jan. 30, 1996 as Bellcore Letter IL-96/01-016, which is incorporated by reference.
This increase in the number of available area codes has allowed many geographic areas to add new area codes in anticipation of increased directory number requirements. Although some subscribers may find the assignment of new area codes to be somewhat inconvenient, the administrators of the NANP have no choice but to add a new area code when nearly all of the directory numbers available under an existing area code have been assigned. Moreover, adding area codes provides local telephone service providers with additional flexibility for implementing billing and dialing plan alternatives for their subscribers. The number of area codes in use in North America, therefore, will likely continue to increase for the foreseeable future.
A distinction should be understood between the numbering plan, which is described above, and what is referred to as a dialing plan. The number plan, which refers to the assignment of directory numbers, is consistent throughout the NANP area and conforms to international numbering standards. A dialing plan, on the other hand, refers to the sequence of digits that a user must dial to place a telephone call from a particular originating station. For many years, only two dialing plans were required in the NANP: a non-toll or local telephone call (i.e., a telephone call to a directory number within the originating station's home area code) was placed by dialing the desired 7-digit terminating destination code; and an "InterLata" long distance or toll telephone call was placed using an 11-digit dialing plan (i.e., by dialing the digit one plus the desired 10-digit directory number). But in recent years, a third, 10-digit dialing plan has been adopted in many locations. This 10-digit dialing plan may not applied consistently across the NANP area and, therefore, can cause confusion in the telephone-using population.
The use of 10-digit dialing plans are not consistent across the NANP area because state or other local regulatory agencies generally determine dialing plans at the local level. As a result, demographic anomalies are often reflected in dialing plans that vary somewhat from location to location. In particular, localities that are close to or straddle area code boundaries may mandate 7-digit dialing zones that encompass portions of two or more area codes. This occurs frequently because area code boundaries often follow state or other political boundaries whereas communities often develop at the confluence of several political subdivisions.
For these multi-area-code communities, regulators may require a 7-digit dialing zone that includes parts of several area codes. Local regulatory requirements may also produce a dialing plan that includes a 7-digit dialing zone and a 10-digit dialing zone within the same area code. In this situation, therefore, a dialed area code is not always sufficient to determine the appropriate dialing plan. Rather, subscribers must learn or look-up the dialing plan on a per-directory-number basis.
Furthermore, area codes are often assigned by splitting a region into two area codes that serve two distinct, usually adjacent, geographic regions.
Alternatively, a new area code may be assigned by overlaying a new area code over an existing area code in the same geographic region. When this happens, a large number of terminating destinations that were formerly in a subscriber's home area code may suddenly become part of a foreign area code. Although the local telephone service provider typically allows non-toll telephone calls between these two area codes, across-area-code telephone calls typically require a 10-digit dialing plan, whereas within-area-code telephone calls typically require a 7-digit dialing plan.
For example, the 404 area code for the Atlanta, Ga. region was recently divided into a 404 area code and a 770 area code. As a result, a 7-digit dialing plan may be used to place a telephone call from a 404 directory number to a 404 directory number, whereas a 10-digit or 11-digit dialing plan must be used to place a telephone call from a 404 directory number to a 770 directory number. An InterLata telephone call from either the 404 area code or the 770 area code requires an 11-digit dialing plan including the digit one plus the desired 10-digit directory number. It should be noted that a toll telephone call may be InterLata or IntraLata. For instance, an IntraLata telephone call from the 404 area code to the 770 area code could be a non-toll (i.e., 10-digit) or a toll (i.e., 11-digit) telephone call depending on the distance between the originating and terminating stations.
Generally stated, the continuing increase in the number of area codes will likely be accompanied by a continuing increase in new 10-digit dialing plans. As a result, a significant number of long-time telephone service subscribers, many of whom are used to using only two dialing plans, will have to learn to use a third, 10-digit dialing plan for the first time. This will lead to increased levels of confusion in the telephone-using population and a corresponding increase in the number of dialing-plan-related service calls that must be handled by local telephone service providers.
To make matters worse, many telephone users have come to rely on caller ID call-back devices to place telephone calls to received directory numbers. These devices typically receive the full 10-digit originating directory number, without any preceding dialed digits, regardless of the dialing plan used to place the in-coming telephone call. Therefore, a caller ID call-back device must be configured to dial the correct dialing plan to place an out-going telephone call to the received caller ID directory number. This typically requires the device to be programmed to accommodate the various dialing plans for a particular location. But pre-programming each caller ID call-back device to accommodate a particular set of dialing plans is complicated by the fact that dialing plans depend on the location of use and can change in an unpredictable manner. Therefore, some prior art caller ID call-back devices are user-programmable.
For example, caller ID call-back devices having two dialing plan selection devices--one for a local (e.g., 7-digit or 10-digit dialing plan) and a second for a long distance (e.g., 11-digit dialing plan)--have been in use for a number of years. These devices may typically be programmed with area codes that require a 7-digit dialing plan and/or a 10-digit dialing plan for local calls, in order to accommodate 7-digit, 10-digit, and 11-digit dialing plans using only two dialing plan selection devices. This allows these devices to be programmed to operate properly in many locations. But because these devices rely on area codes to determine dialing plans, they cannot be programmed to operate properly for all directory numbers in locations in which more than one dialing plan is required to place telephone calls to directory numbers within the same area code.
Moreover, some users will inevitably fail to program their caller ID call-back devices properly. For example, a user may purchase a caller ID call-back device and initially program the device to operate in a particular location. The user may later move the caller ID call-back device to a new location. In many cases, the caller ID call-back device must be reprogrammed to operate properly in the new location. If the user has lost or discarded the instruction manual, the user may have to place a service call to the local telephone service provider or the manufacturer of the caller ID call-back device to determine how to reprogram the device. Therefore, disseminating a large number of caller ID call-back devices with two dialing plan selection devices can be expected to cause a significant number of service calls.
There is, therefore, a need for a caller ID call-back device that is intuitively easy to understand. There is a further need for a caller ID call-back device that does not have to be programmed to properly dial selected directory numbers using three different dialing plans.

BellSouth Intellectual Property Corporation


A method for making low-resistance contacts between polysilicon and metal silicide on semiconductor integrated circuits is described. The method is particularly useful for making low contact resistance (R.sub.c) between the tungsten polycide word lines and the access (pass) transistors (FETs) on DRAMs. A first polysilicon/first silicide (polycide) layer is patterned to form a first polycide conducting layer for the FET gate electrodes. A dielectric layer is deposited over the patterned first polycide layer, and contact openings are anisotropically plasma etched in the dielectric layer to the surface of the first silicide layer. A second doped polysilicon layer is deposited on the substrate and over and in the contact openings contacting the first silicide layer. Prior to depositing a second silicide layer, a high-temperature rapid thermal process (RTP) or annealing is carried out to alter the second polysilicon/first silicide interface to reduce the contact resistance (about 10 ohms). This RTP eliminates the need for overetching the first silicide in the contact holes, as commonly practiced in the prior art. A second silicide layer is deposited and the second silicide/polysilicon (second polycide) is patterned to form the next level of interconnections, such as the word lines for the array of DRAM cells.

(1.) Field of the Invention
The present invention relates to a method for making low-resistance contacts between polysilicon and metal silicide for multilevel interconnections on semiconductor integrated circuits. More particularly, the method relates to forming low-resistance contacts using a rapid thermal process (RTP), thereby eliminating the need to overetch the contact holes to remove the silicide between interconnecting polycide layers.
(2.) Description of the Prior Art
Continuing advances in high-resolution photolithography and anisotropic plasma etching have reduced the minimum feature sizes of semiconductor devices. For example, the current minimum feature size of the gate electrodes for field effect transistor semiconductor devices is sub-half-micromenter (.mu.m) (about 0.35 .mu.m or less). These reduced feature sizes require smaller contact holes that lead to higher contact resistance (R.sub.c). For example, current contact hole feature sizes are now typically much less than 0.5 micrometer (.mu.m), and to make contacts to the FET gate electrodes, the contacts must be less than 0.35 .mu.m in width or diameter. The increase in this parasitic resistance in series with circuit devices, such as field effect transistors (FETs), degrades the circuit performance and therefore is undesirable. A further concern is the wide distribution in contact resistance (R.sub.c) that can occur over the large number of contact holes that are simultaneously etched, and is also very undesirable.
It is common practice in the semiconductor industry to interconnect the semiconductor devices by using multilayers of patterned heavily doped polysilicon having a top silicide layer, commonly referred to as polycide layers, and by metal layers to form the integrated circuits. Because of electrical device characteristics and temperature considerations, it is desirable to form the gate electrodes for FETs and the next level of electrical interconnections contacting the gate electrodes from a first and second level of patterned polycide layers, respectively. An InterLevel Dielectric (ILD) layer, hereafter referred to as simply a dielectric layer, is used between the patterned polycide layers to electrically insulate the various levels of patterned polycide layers. Contact holes are formed in the dielectric layer to electrically interconnect the first and second polycide layers. On Ultra Large Scale Integration (ULSI), the number of contacts now well exceeds a million, and it is important to have consistently low and tight distributions of the contact resistance (R.sub.c).
The problem of high contact resistance is of particular concern between the two patterned tungsten polycide (silicide (WSi.sub.2)/polysilicon) layers used to form the gate electrodes of the pass transistors (FETS) and the word lines for the dynamic random access memory (DRAM) and other integrated circuits, such as static random access memory (SRAM), microprocessors, and the like.
Unfortunately, when the contact holes are etched in the dielectric layer to the first polycide layer, it is difficult to form consistently low contact resistance. For example, contacts having minimum feature sizes of 0.5 .mu.m or less can have contact resistance that varies from as low as 100 ohms to values exceeding 2000 ohms. Furthermore, interface treatments, such as plasma etching in a gas mixture containing CH.sub.4 and O.sub.2 to treat the tungsten silicide surface, are not effective, even when portions of the top surface of the first silicide layer are removed. Also, implant doping of the tungsten silicide layer in the contact holes does not provide consistently low contact resistance. One method of consistently reducing the contact resistance is to completely remove the first silicide layer in the contact holes. However, it would be desirable to avoid overetching the contact holes and removing completely the first silicide layer to the first polysilicon layer.
Several methods of forming polycide structures are described in the literature, but do not address the contact resistance problem. For example, Moslehi, U. S. Pat. No. 5,322,809, teaches a method for making self-aligned silicide on the source/drain and FET gate electrode of different thickness, but does not address the high-resistance contact problem between polycide levels. Kapoor, U. S. Pat. No. 5,498,558, shows a method of forming a floating electrode structure for EPROM applications, and completes the structure by forming contacts of doped polysilicon or tungsten to the source/drain and control gate electrode. However, the gate electrode is polysilicon and not polycide, and therefore would not experience the high contact resistance problem. Redwine, U. S. Pat. No. 5,109,258 teaches a method for making memory cells by selective oxidation of polysilicon, and uses a platinum silicide layer on the gate to provide low resistance, but does not address the problem of high contact resistance as commonly experienced with the refractory metals, such as tungsten. Mutsaers et al., U.S. Pat. No. 5,399,235, teach a method for making two levels of aluminum conducting tracks, and would not be concerned or address high contact resistance between polycide layers.
Therefore, there is still a need in the semiconductor industry to reduce the contact resistance between tungsten polycide layers, while avoiding the necessity of removing the first silicide in the contact holes.

Method for making low-resistance contacts between polysilicon and metal silicide on semiconductor integrated circuits

Vanguard International Semiconductor Corporation


An optical fibre device based on the Raman effect comprises a first optical source to provide light at a first wavelength, and a holey optical fibre which receives the light from the first optical source such that optical gain or loss is provided at a second wavelength by the effect of Raman scattering within the fibre. For optical gain, the second wavelength is longer than the first wavelength, and the device can be operated as an amplifier, or as a laser if optical feedback is provided. For optical loss, the second wavelength is shorter than the first, and the device may be used as an optical modulator. The fibre may be fabricated from pure silica, although other undoped or doped materials may alternatively be used to tailor properties of the fibre such as gain spectrum, bandwidth, power handling capability and mode propagation.

The present invention relates to optical fibre-based devices which utilise Raman scattering. In particular, the devices include optical amplifiers, optical modulators and lasers.
The capability of silica optical fibres to carry large amounts of information over long repeaterless spans in telecommunications systems makes lightwave communications very attractive. Numerous channels at different wavelengths can be multiplexed on the same fibre to maximise the use of the available bandwidth. Higher transmission powers and/or lower loss fibres can increase system margins.
A device commonly used to compensate for the losses in fibre is the erbium-doped fibre amplifier (EDFA). This is based on silica fibre doped with erbium, which, when pumped with light of a suitable wavelength, provides optical gain and hence amplification of optical signals passing through the fibre. The properties of erbium mean that the bandwidth of the available gain is approximately 30 to 40 nm around 1550 nm. This places a severe limitation on the bandwidth of the telecommunications system as a whole, because only optical signals within this wavelength range can be adequately transmitted.
Also, attempts to fully utilise the capabilities of silica fibres for telecommunications applications tend to be limited by nonlinear interactions between information-bearing optical signals travelling in the fibre, and the fibre itself. These optical nonlinearities can lead to distortion, excess attenuation and interference of the optical signals, resulting in system degradations. There are many nonlinear optical effects in fused silica fibres, each of which have unique properties. Generally, these nonlinear effects can be divided into two categories. The first relates to elastic phenomena. In an optical fiber the core in which the optical signals travel has a specific refractive index that determines how fast light travels through it. However, depending upon the intensity of light travelling in the core, this refractive index can change. This intensity-dependence of the refractive index is called the Kerr effect. It can cause self-phase modulation (SPM) of a signal, whereby light at one wavelength channel can broaden out spectrally onto adjacent wavelength channels through its own self action within the medium. It can also cause cross-phase modulation (XPM), whereby several different wavelengths in a WDM system can cause each other to spectrally broaden and spread out. Finally, it can result in four-wave mixing (FWM), in which two or more signal wavelengths can interact to create a new wavelength. A second category of nonlinear effects results from stimulated inelastic scattering, in which energy is exchanged between the electromagnetic field and the dielectric medium. Effects in this category are stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS), which are related to the excitation of vibrational modes of silica. The main difference between the two is that optical phonons participate in SRS while acoustic phonons participate in SBS.
Many nonlinear effects can be problematic for telecommunications systems. However, SRS can be used for optical amplification, as an alternative to EDFAs.
The Raman effect is described quantum-mechanically as a scattering of an incident photon by a molecule to a lower frequency photon while at the same time the molecule makes a transition between vibrational modes. SRS occurs when the incident photons are contained in a very intense pump wave. This results in very high Raman gain such that much of the pump energy is transferred to light at the lower frequency, called the Stokes wave. This nonlinear process can turn optical fibers into broadband Raman amplifiers [1], Raman lasers [2] and also SRS-based modulators [3]. On the other hand, it can also limit the performance of multichannel lightwave systems by transferring energy from one channel to red-shifted neighbouring channels.
A Raman amplifier provides an attractive and convenient choice of broadband optical amplifier due to the fact that the bandwidth of the gain can be tuned by simply changing the pump wavelength. The gain can be tailored to a desired communications wavelength, hence overcoming the drawback of the narrow gain bandwidth capabilities of EDFAs. Thus, particular interest in Raman amplifiers lies in the optical communication bands (short (S) band and long (L) band) outside the conventional EDFA gain window (C band). Moreover, by pumping such amplifiers with a combination of different pump wavelengths it is possible to further extend and shape the available gain bandwidth.
A problem with the Raman amplifier is that it requires a high power pump laser. However, the recent availability of high power lasers (typically ˜b 5 W) in the 1400 nm region makes Raman amplification in the desired S. C and L bands possible. A further drawback of the Raman amplifier is the need for long lengths of fibre (˜10 km), which increases the bulk and cost of these devices.
It is thus desired to provide an optical fibre amplifier which addresses the disadvantages of known devices, in particular problems relating to fibre length and limited bandwidth.

Optical fibre-based devices utilising the Raman effect