A process for forming a semiconductor device comprises the steps of providing a semiconductor substrate assembly comprising a semiconductor wafer having an active area formed therein, a plurality of transistor gates each having a TEOS cap thereon and a pair of nitride spacers along each gate, a plurality of conductive plugs each contacting the wafer, and a BPSG layer overlying the transistor gates and contacting the active area. A portion of the BPSG layer is etched thereby exposing the TEOS caps. A portion of the BPSG layer remains on the active area after completion of the etch. Subsequently, a portion of the TEOS caps are removed to expose the transistor gates and a titanium silicide layer is formed simultaneously to contact the transistor gates and the plugs. An inventive structure resulting from the inventive process is also described.

Structures such as polycrystalline silicon (poly) plugs, interconnects, and transistor gates are commonly formed during the manufacture of semiconductor devices such as microprocessors, memory devices, and logic devices. To manufacture a plug, for example, a masked dielectric layer is formed over an underlying substrate assembly and an etch is completed to form a hole in the dielectric which exposes the underlying structure in the area where contact is to be made. A blanket poly layer is deposited over the dielectric layer which fills the hole in the dielectric layer and contacts the underlying structure. The poly is then removed from a planar surface of the dielectric, typically using a chemical mechanical polishing (CMP) process which leaves the plug formed within the dielectric layer. Interconnects and gates are typically formed by depositing a blanket layer of poly over a semiconductor substrate assembly, then masking and etching the layer.
As the sizes of the plugs and line widths decrease with improving manufacturing technology, the doped poly structure may provide excessive resistance and insufficient conductance. To reduce the resistance of a structure, a silicide layer is often formed underneath the plug or over the top of the plug, gate or interconnect. To form the silicide layer to enhance plug conductivity the silicide layer can be formed before formation of the plug. A titanium chemical vapor deposition (CVD) process results in titanium reacting with the exposed silicon wafer to form titanium silicide. An unreacted titanium metal layer will also form over any exposed dielectric layer which is then stripped. After stripping the unreacted titanium, the poly plugs are formed over the silicide layer as described above.
A silicide layer can also be formed over the plug, transistor gate or other interconnect after forming the blanket poly layer which forms the gate or interconnect. During a titanium CVD process similar to that described above for forming silicide under the plug, the titanium reacts with the polysilicon to form silicide on top of the poly layer, then the poly is masked and etched to define the line or plug.
U.S. Pat. No. 5,381,302 by Sandhu et al. and U.S. Pat. No. 5,198,384 by Dennison, each assigned to Micron Technology, Inc. and incorporated herein by reference in their entirety, describe a process for forming a silicide layer over a poly plug.
While the silicide layer interposed between the silicon wafer and the poly plug provides decreased resistance and increased conductance it can also provide a path for leakage between an adjacent transistor channel region and an active area, thereby increasing junction leakage. A process and structure which provides improved conductance and reduced resistance and which does not increase junction leakage would be desirable. It would be further desirable to provide a plug having a maximized amount of silicide formed thereon.

Low resistance semiconductor process and structures


A substantially spherical hand-held input device which provides manual data input for navigating a virtual environment and other kinds of user interface, includes a capacitive touch sensor responsive to touch events anywhere on its surface, the touch sensor including a propagation-enhancing portion so that gestural radio signals can be transmitted through the touch-sensitive surface of the input device to a computer system during use, the propagation-enhancing portion being in the form of a spiral-shaped conductor that is also used for capacitance-sensing, and a multi-touch array includes multiple spiral-shaped touch-sensing conductors to provide the propagation-enhancing portion, and the propagation-enhancing portion is a metamaterial at a transmission frequency of the gestural radio signals.

1. Field of the Invention
The present invention relates to transmitting data wirelessly, and in particular relates to transmitting data from within an enclosed touch sensing surface of an input device.
2. Description of the Related Art
The computer mouse revolutionized desktop computing, and the touch screen subsequently revolutionized mobile computing. These two types of input system highlight the importance of user input devices, and demonstrate their ability to transform advanced technologies from expensive scientific tools into low cost everyday items. In spite of diverse research efforts, there is no standard input device for navigating three-dimensional virtual environments. Virtual worlds are presented with increasingly high quality due to the decreasing cost of graphics processors, which are subject to Moore's law. Displays more than a meter across are commonplace consumer products. However, virtual environments displayed on them must be navigated using a joystick, or a mouse and keyboard, or using any one of several input technologies specialized for a particular application.
Examples of virtual environments include many kinds of computer games, three-sixty degree videos and photographs. Anyone with a web browser can, in theory, rotate, zoom and otherwise navigate these immersive experiences using a keyboard and mouse. However, this method of navigation is very cumbersome. Similarly, a smartphone can be used to view three-sixty videos by holding the device in the air and rotating it as if it were a virtual window. This viewing method is tolerable for a few tens of seconds, and serves primarily as a technology demonstrator.
One attempt to make virtual environments more comfortable is to use a virtual reality headset, which replaces most of the user's field of view with a pair of synthetic images, one for each eye. Head movements are tracked so that the images supplied to each eye are updated as if the user is actually in the virtual environment. Although the sense of immersion can be profound, it is easily broken when moving around the environment, due to the nature of input devices used to facilitate movement. Furthermore, a headset cuts the user off from their social environment, and may be uncomfortable to wear for extended periods of time. User movement in a virtual environment is known as locomotion, and the problem of locomotion in virtual reality (VR) is widely considered to be a fundamental obstacle to its wider adoption. However, more generally, user movement in any kind of three-dimensional virtual environment lacks a widely accepted universal input device analogous to the mouse or touch screen. This problem exists regardless the type of display system used.
In U.S. Pat. No. 6,891,527 B1 a hand-supported sphere is proposed as a universal input device. Passive acoustics are used to track the movement of a fingertip across the sphere's surface. The passive acoustic sensor aims to solve a particular problem: When using the sphere for input, it is rotated arbitrarily. Therefore, the entire surface must be activated uniformly for touch detection, otherwise a particular orientation would result in a user input gesture being impossible or difficult to detect. The touch-sensitive spherical surface encloses a radio transmitter that transmits gesture data to an external processing system. A resistive or capacitive touch-sensing matrix would act as a Faraday cage, attenuating or preventing radio transmissions from the input device being received. The passive acoustic system avoids this problem. However, passive acoustics relies on the sound created by a finger movement or tapping, and is limited in the vocabulary of gestures that can be detected.
Spherical input devices have been subsequently disclosed in US 2012/0154267 A1, US 2013/0027299 A1, US 2015/0054633 A1 US 2015/0097774 A1, WO 2007/077124 A1, and EP 3 190 483 A1. These documents describe freely-held spherical input devices that include one or more pressure sensors for detecting a force applied by squeezing the surface. The pressure sensors are sparsely located, avoiding the need to transmit radio signals through the conductive matrix of a resistive or capacitive touch sensor that fully covers the surface. However, squeezing is not as easy to do as touch, and these devices also have a relatively limited gestural vocabulary. In WO 2011/011898 A1 and https://lauralahti.com/The-Smartball, a freely held spherical input device is described, but these documents do not address the technical problem of providing a touch sensor that fully covers a spherical surface.
The potential of a spherical input device for universal input is significantly limited by the kinds of gestures that known systems can detect, especially compared to the sophisticated touch screen interactions, such as pinch and zoom, that most people are now familiar with.


The present invention relates to a method of detecting whether at least one die is centered about a thread held taught between two fixed points separated by a distance L, wherein:. the thread is excited into vibration; PA1 its frequency F of vibration is measured; PA1 the corresponding length 1 of vibrating chord between one of said fixed points referred to as a "reference" fixed point and another point referred to as a "contact" point is deduced therefrom; and PA1 length l is compared with length L and with the length of the segment of thread between said reference fixed point and said die, so as to deduce therefrom:. either that the thread is touching said die, if length l corresponds to the length of the segment, said contact point then being situated at said die; PA2 or else that the thread is not touching said die, if length l is equal to the length L between said two fixed points, in which case said die is properly centered, said contact point then coinciding with the other one of said fixed points.

In particular, the invention may be applied to manufacturing an optical fiber on a fiber-drawing lathe. It is known that the fiber is produced from a preform or fiber-drawing cone that is heated. The resulting fiber passes successively through two resin-coating dies so as to provide the fiber with a certain amount of strength. The fiber is then wound onto a capstan applying a certain amount of tension to the fiber. The fiber-manufacturing assembly is disposed vertically.
It is necessary for the two dies to be centered accurately on the fiber so that it is coated properly. If the fiber touches a die, the thickness of the coating is not properly uniform around the entire periphery of the fiber, and the rate of fiber breakage increases.
Currently, a laser is used for centering dies, but given the size of the dies, diffraction occurs and that method is not very satisfactory. The diameter of a helium-neon laser beam is about 0.8 mm, whereas the first die has a diameter of about 0.24 mm, and the second die has a diameter of about 0.32 mm. To avoid diffraction, the diameter of the hole needs to be three or four times the diameter of the light beam.
Another method used relies merely on operator skills, and often means that the alignment achieved is not repeatable.

Method of detecting whether at least one die is centered about a thread held taught between two fixed points


An improved process for manufacturing high-grade and high-quality graphite fibers by the steps of (a) heating carbon fibers from acrylic fibers in an initial heating zone while exposed to an atmosphere of inert gas having a maximum temperature from about 1700.degree. C. to 1900.degree. C., and (b) then heating the resulting fibers in a subsequent heating zone while exposed to an atmosphere of inert gas having a maximum temperature from 2300.degree. C. to 2700.degree. C.

Graphite fibers are generally different from carbon fibers in respect of carbon content (purity), fiber structure and fiber characteristics, for example. Graphite fibers are much more useful and effective than carbon fibers when used in sports equipment such as fishing rods and golf club shafts which require high modulus, when used in electric components such as heaters which require high purity and low resistivity and when used for aerospace parts such as aircraft, rockets and the like which require oxidation resistivity and high precision. However, graphite fibers cost much more than carbon fibers and this high cost is largely a result of difficulties in manufacturing processability and productivity. An inert atmosphere is required for production of graphite fibers, and a higher temperature is used than for carbon fibers.
Efforts have been made to increase productivity in manufacturing graphite fibers. For example, it has been proposed to increase the temperature gradient and to shorten the residence time in the graphitizing furnace. However, this produces increased amounts of fuzz on the graphite fiber surfaces and occasionally causes breakage of the running fiber strands.
Also, these modifications tend to reduce the tensile strength of the fibers. Further, since the temperature of the inert atmosphere must be higher than that used for manufacturing carbon fibers, the wear and tear on the graphitizing furnace, particularly on its heating pipes, is very considerable. With such wear and tear due to exceedingly high temperatures, deviations from the desired temperature profile tend to increase very substantially and the furnace tube must be frequently changed. This seriously interferes with productivity and processability, and also consumes large amounts of energy, labor and materials.
With regard to such a graphitizing method, there are one-stage graphitizing methods such as disclosed in U.S. Pat. Nos. 3,700,511, 3,900,556, 3,954,950, 3,764,662 and British Pat. No. 1,215,005.
U.S. Pat. No. 3,700,511 shows a conventional graphitizing method for making a carbon fiber from a fiber which is first oxidized in the temperature range of from 1000.degree. C. to 1600.degree. C. and then successively pyrolyzed up to a temperature of 2500.degree. C. in a graphitizing zone.
U.S. Pat. No. 3,900,556 shows a process for preparing a graphite fiber by rapidly graphitizing an oxidized fiber in a short period of time, such as from 10 seconds to 60 seconds. However, according to this method, it is difficult to obtain as good a temperature profile as possible by this invention. Also, in a rapid graphitizing process, the oxidized fiber is heated very rapidly and develops excessive surface fuzz and tends to break off easily.
U.S. Pat. No. 3,900,556 also shows a rapid graphitizing method. However, the method is in respect to an oxidized fiber, and it uses a carbonizing and one-stage graphitizing procedure. By this method, it is difficult to obtain a small temperature gradient in the vicinity of 1700.degree. C. which is essential in order to obtain a good graphite fiber.
U.S. Pat. No. 3,764,662 discloses a method wherein oxidized fiber is heated at a temperature from 1300.degree. C. to 1800.degree. C. for at least an hour and then a graphite fiber is obtained by heating at a further temperature of from 2300.degree. C. to 3000.degree. C. for 30-90 seconds. However, this method is not practical for an industrial process because of the very long heating time in the first stage. Similarly, the procedure according to British Pat. No. 1,215,005 would not be practical as a commerical process. According to British Pat. No. 1,215,005 a graphite fiber is obtained by successively subjecting an organic fiber, through a first oxidizing furnace to a fourth graphitizing furnace. However, the heat increase rate from the second to the third furnace, which have a temperature range from 1000.degree. C. to 1700.degree. C., is very slow, i.e., 300.degree. C./hr. Also, the residence time in the furnace is very long, namely, from 30 minutes to 4 hours in the second furnace and a maximum of 3 hours in the third furnace. Moreover, the residence time in the temperature range of 2000.degree. C. or more in the fourth graphitizing furnace is also from 30 minutes to 2 hours. Overall, such a process would not be a practical industrial process.
It is an object of this invention to provide a stable method of manufacturing high grade and high quality graphite fibers from carbon fibers made from acrylic fibers, particularly, it is an object to manufacture graphite fibers which have a minimum of surface fuzz. Another object is to provide a process for shortening the heating zone. Another object of this invention is to provide a method of manufacturing graphite fibers in which the matter of changing parts such as furnace tubes and the like, can be easily carried out, wherein the life of the parts is lengthened, costs for energy, materials and labor are materially reduced.
These and other objects are attained by the present process by providing a graphitizing furnace which is divided into two zones and by utilizing specific temperature ranges.

Process for continuous graphitization of graphitizable precursor fibers


There is provided an information processing device including an operation history acquisition unit for acquiring operation history information in which an input operation of a learner terminal by a learner who uses learning content is associated with a time at which the input operation is acquired, and an acceptance ability estimation unit for estimating an acceptance ability of the learner with regard to the learning content based on the operation history information.

The present disclosure relates to an information processing device and an information processing method.
In recent years, electronic learning has become increasingly popular in learning. For example, learning materials such as textbooks are being provided in an electronic format. Thus, interaction such as a decision of correct and wrong answers to questions that was made between learners and teachers in former times is performed automatically by a computer in recent years, and interaction between learners and teachers through a communication line is becoming a common practice.
In such an electronically supported learning, techniques have been proposed for grasping in more detail the situation of students (learners) and for providing learning materials or exercises more appropriately according to the situation. These techniques are disclosed in Japanese Patent Application Laid-Open Publication Nos. 2011-7963, 2006-23506, and 2009-75469.

Information processing device and information processing method for estimation of acceptance ability


Disclosed embodiments provide systems, methods, and computer-readable storage media for stress testing a vehicle identification model by determining image quality parameters optimizing model confidence values. The embodiments comprise one or more memory devices storing instructions and one or more processors configured to execute instructions. The one or more processors perform operations comprising receiving a first set of images of the vehicle, wherein the images contain preset values for parameters comprising at least one of a rotation, a focus, a contrast, and a color. The system further analyzes the first set of images with an identification model and determining an initial identification confidence of the vehicle. The system further modifies the first set of images, compares the modified images to the first set of images, and determines whether the model should be modified based on at least the comparison.

Extant image recognition systems, such as classifiers, cascading classifiers, neural networks, convolutional neural networks, or the like are used to receive an image of an object and determine the identity of the object. These systems may achieve high accuracy (e.g., comparable to humans) when the received image contains high-quality attribute and pixel data. However, the accuracy of extant systems is decreased when low-quality images are used. This is due, in part, to conflicting classifications when different objects (such as a vehicle and a person, a kitten and a ball, or the like) are present within the image, and more importantly, a recognition system is unable to determine the differences in objects because of the quality of image attribute data.
In particular, such systems, which often comprise neural networks or convolutional neural networks, may detect a plurality of objects within an image, recognize classes of objects within the image, and assign several potential identifications of the classes based on confidence scores. However, such processes usually generate many (e.g., on the order of 1000 or more) identified classes, and a few adjustments to attributes of the image may significantly alter an identified class distribution of the process.
One solution for improving image recognition or object detection is "stress testing" such systems, that is, determining the impact of several attribute adjustments in a controlled manner by isolating a single attribute for a received and identified image, repeatedly adjusting the attribute from minor to extreme modifications, determining the recognition confidence (e.g. the object identification) for each adjustment, and repeating this process for each tested attribute. By doing so, it may be possible to build a baseline relating to image quality and attribute data. The data from stress testing may be used to create distribution and statistical analysis to further understand whether minor, or extreme, modifications improve the recognition systems so that image quality may be properly mitigated in future image object identification.
The present disclosure provides systems, methods, and devices to further improve the accuracy of such object recognition processes by stress testing image recognition models using modified images. By building a baseline and quality control parameters, the identification process is further able to account for image quality by modifying image attributes, such as rotation, focus, brightness, contrast, black/white, and color.

Systems and methods for quality assurance of image recognition model


Intelligent radio access technology sensing and selection are applied in a dynamic traffic steering network. Network characteristics and network policies are determined. A server sends network characteristics and network policies to user equipment devices. User equipment devices can determine a radio access technology to connect to based on network policies and network characteristics. Further, it can be determined how to select user equipment devices for connection to a radio access network via a radio access technology. User equipment devices can dynamically select a radio access network for connection based on real-time or near real-time radio access network conditions. A self-organizing network can monitor and determine radio access network conditions and the radio access network conditions can be sent to user equipment devices in given cellular broadcast area.

Wireless service providers are observing an exponential growth in mobile communications due to both an increase in consumer demand and commercial requirements. To ensure customer satisfaction, wireless service providers aim to deliver a high quality service at any location, to facilitate reliable and efficient mobile communications. Consumers can access a growing number of networks using a mobile device. These networks include, for example, 3G networks, 4G networks, long term evolution networks and Wi-Fi networks. These networks allow consumers to communicate voice, text, multimedia, and other data to and from other network entities, such as servers and other mobile devices.
The number of consumers accessing these networks and the amount of bandwidth used by consumers are rapidly increasing. With this rapid increase, mobile traffic is also increasing along the networks placing strain on networks and network resources. The strain can result in a bottleneck restricting data flow, such as at a cellular base station. When networks are strained, consumers can experience a diminished quality of service and become frustrated.

This patent is subject to a terminal disclaimer.

Dynamic steering of traffic across radio access networks


A method for processing a substrate disposed in a substrate processing chamber to modify the contour of a trench formed on the substrate. The substrate processing chamber is the type that has a coil and a plasma generation system including a source power system operatively coupled to the coil and a bias power system operatively coupled to the substrate process chamber. The method includes transferring the substrate into the substrate process chamber. Thereafter, the substrate is exposed to a plasma formed from a first process gas consisting essentially of a sputtering agent by applying RF energy from the source power system to the coil. The plasma is biased toward the substrate by applying bias power to the substrate process chamber. Thereafter, the substrate is exposed to a plasma formed from a second process gas without applying bias power or applying minimal bias power to the substrate process chamber.

The present invention relates to a process and apparatus for etching silicon. More specifically, the present invention relates to trench etching and to forming trench structures in a silicon substrate.
Trench etching is a common procedure in the semiconductor fabrication process. The trenches are etched into a silicon substrate to form structures such as vertical transistors, isolation trenches, capacitors and others found in integrated circuits. Trenches are generally etched by forming a patterned photoresist on the surface of the substrate and then etching the exposed parts of the substrate. One or more layers of material are formed over the trench, as required, depending on the structure desired.
Referring to FIG. 1, as explained above, one use of a trench is for the formation of a vertical transistor 50. The transistor includes a trench 52, a gate oxide 54 formed over trench 52, and a polysilicon layer 56 deposited over the gate oxide and filling the trench. A drain region 58 is provided at a portion of substrate 51 adjacent to the top corners of the trench. A source region 60 is provided at a portion of substrate 51 adjacent to the bottom of corners of the trench. A channel 62 is formed between the source and drain regions to electrically couple the two regions when a voltage is applied to polysilicon 56.
Trench 52 may be formed using either wet etch techniques or dry etch techniques. Currently, dry etch techniques, particularly anisotropic methods, are generally used to form a trench with a high aspect ratio. The aspect ratio refers to a ratio of trench height to trench width. An anisotropic etch technique generally involves accelerating ions toward the substrate to etch the exposed portions of the substrate. The ions are accelerated vertically so the etching is done mostly in a vertical direction. The trench formed using such a method tends to have sharp top and bottom corners 64 and 66. The electrical field intensity at the corners increases proportionally with the sharpness of the corners. Therefore, sharp corners 64 and 66 lower the breakdown voltage of transistor 50, i.e., the maximum voltage that can be safely handled by a transistor without oxide breakdown.
In addition, ion bombardment from the anisotropic etching process may damage the outer silicon surface of the trench (e.g., outer 50-100 angstrom). For example, ion bombardment may leave the surfaces of the trench walls with numerous tiny craters, i.e., uneven surfaces. The bombardment also dislodges silicon atoms from the crystal structure and damages the crystal structure, which alters the electrical properties of the silicon substrate.
Therefore, semiconductor manufacturers generally desire to round the corners of a trench and repair the damaged outer surfaces before filling the trench and completing the formation of an integrated circuit. This process conventionally involves using at least two different etching chambers, for example, a capacitance-type etcher, and a microwave downstream etcher. The capacitance-type etcher ignites a plasma within its process chamber and uses ion bombardment to round the top corners. Then the substrate is transferred to a microwave downstream etcher. The microwave downstream etcher ignites a plasma remote from the process chamber. Radicals from the remote plasma are flowed into the process chamber to isotropically etch the trench. This isotropic etch simultaneously rounds the bottom corners and removes the damaged outer surfaces from the trench sidewalls. The top comers are further rounded during this isotropic etching.
While the conventional method works well for some processes, improvements to the process are desirable. First, the conventional process requires the use of two or more different etch chambers to modify the contour of a trench. Also, since the process simultaneously rounds the bottom corners and removes the damaged outer surfaces, these steps cannot be independently controlled. Accordingly, there is a need for an etch method which allows the contour of a trench to be modified in a single chamber and which performs the top corner rounding, bottom corner rounding, and damaged outer surface removal steps separately.
The present invention provides an improved method for modifying the contour of a trench formed on a substrate. The method rounds the top corners of the trench and performs additional trench contouring in a single chamber. The additional trench contouring includes either or both rounding the bottom corners of the trench and removing damaged outer surfaces of the trench. The method of the present invention performs each of the trench contour modification steps independently in a sequential, in-situ process that allows the contour of a trench to be tailored to a particular process. The present invention is particularly useful for the formation of high-aspect-ratio trenches in a semiconductor fabrication process.
In one embodiment of the present invention, a substrate disposed in a substrate processing chamber is etched to modify the contour of a trench formed on the substrate. The substrate processing chamber is the type that has a coil and a plasma generation system including a source power system operatively coupled to the coil and a bias power system operatively coupled to the substrate process chamber. The substrate is transferred into the substrate process chamber. The substrate is then exposed to a plasma formed from a first process gas consisting essentially of a sputtering agent by applying RF energy from the source power system to the coil. The plasma is biased toward the substrate by applying bias power to the substrate process chamber. Thereafter, the substrate is exposed to a plasma formed from a second process gas without applying bias power or applying minimal bias power to the substrate process chamber.
In another embodiment of the present invention, a substrate disposed in a substrate processing chamber is etched to modify the contour of a trench formed on the substrate. The substrate processing chamber includes a bias power system operatively coupled to the substrate process chamber. The substrate is transferred into the substrate process chamber. A first plasma is ignited from a first process gas consisting essentially of a sputtering agent. The substrate is exposed to ions and electrons dissociated in the first plasma, and the plasma is biased toward the substrate by applying bias power to the substrate process chamber. Thereafter, a second plasma is ignited from a second process gas having a halogen source, and the substrate is exposed to ions and radicals dissociated in the second plasma without applying bias power or applying minimal biasing power to the substrate process chamber. The first and second plasmas can be formed remote from the substrate processing chamber or can be formed within the chamber.
Yet in another embodiment of the present invention, a substrate is etched to form a trench thereon. A photoresist layer is patterned on the substrate to define a location for the trench. The substrate is etched to form the trench. The photoresist layer is stripped from the substrate. The substrate is transferred into a substrate processing chamber having a plasma generation system with separate controls that can independently adjust source power and bias power. The substrate is processed by flowing a first gas consisting essentially of a sputtering agent into the chamber to form a first plasma from the first gas and etching the substrate with the first plasma by applying both source power and bias power. Thereafter, a second gas including a halogen source is flowed into the substrate process chamber to form a second plasma from the second gas. The substrate is etched with the second plasma by lowering or grounding the bias power being applied to the chamber.
These and other embodiments of the present invention, as well as its advantages and features, are described in more detail in conjunction with the text below and attached figures.

Method for rounding corners and removing damaged outer surfaces of a trench


This application discloses a novel process to synthesize 2-(Quinolin-5yo)-4,5-Disubstituted-Azole derivatives, which may be used, for example, as PDE IV inhibitor compounds in pharmaceutical preparations.

As described in Published international application WO 2005/116009 A1 (the '009 publication) and published U.S. patent application no. 2006/0106062 (the '062 publication), each of which was filed on May 16, 2005 (the '009 publication), and each of which is incorporated herein in its entirety by reference, 2-(Quinolin-5-yl)-4,5 Disubstituted-Azole derivatives (Formula I) which have pharmaceutical activity as PDE-4 inhibitor compounds.
wherein:
X is O or S
R1 is H, alkyl, cycloalkyl, cycloalkyl(C1-C4)alkyl-, —CH2F, —CHF2, —CF3, —C(O)alkyl or —C(O)NR18R19;
R2 is —OR* or —N(R7)(R8), wherein R* is linear, branched, or cyclic alkyl or substituted linear, branched, or cyclic alkyl, and R7 and R8 are defined herein below;
R3 and R4 are independently selected from the group consisting of H, alkyl, hydroxyalkyl and —C(O)Oalkyl;
R5a and R6b are independently selected from the group consisting of H, alkyl, hydroxyalkyl, alkoxyalkyl, mercaptoalkyl, —CH2F, —CHF2, —CF3, —C(O)OH, —C(O)Oalkyl and —C(O)NR43R44;
t is 1 or 2;
R7 is H, alkyl, alkenyl, hydroxyalkyl, cycloalkyl, alkoxyalkyl, aminoalkyl, (R17-phenyl)alkyl or —CH2—C(O)—O-alkyl;
R8 is H, alkyl, alkenyl, alkoxy, alkoxyalkyl, hydroxyalkyl, dihydroxyalkyl, alkyl-NR18R19, cyanoalkyl, R23-heteroaryl, R23-heteroarylalkyl, (R36-heterocycloalkyl)alkyl, R17-phenyl, (R17-phenyl)alkyl, R7-naphthyl, (R17-naphthyl)alkyl, R17-benzyloxy, -alkyl-C(O)—NR18R19, -alkyl-C(O)—N(R30)—(R23-heteroaryl), -alkyl-C(O)—N(R30)-(cycloalkyl), -alkyl-C(O)—(R36-heterocycloalkyl); -alkyl-N(R30)—C(O)Oalkyl, -alkyl-N(R30)—C(O)—NR18R19, -alkyl-N(R30)—C(O)alkyl, -alkyl-N(R30)—C(O)-(fluoroalkyl), -alkyl-N(R30)—C(O)—(R39-cycloalkyl), -alkyl-N(R30)—C(O)—(R17-phenyl), -alkyl-N(R30)—C(O)—(R23-heteroaryl), -alkyl-N(R30)—C(O)-alkylene-(R23-heteroaryl), -alkyl-NH—SO2—NR18R19, -alkyl-N(R30)—(R17-phenyl), -alkyl-N(R30)—(R23-heteroaryl), -alkyl-O—(R17-phenyl), -alkyl-O—(R23-heteroaryl), -alkyl-N(R30)—SO2-alkyl, R45-hydroxyalkyl, dihydroxyalkyl substituted by R17-benzyloxy, dihydroxyalkyl substituted by R17-phenyl, alkoxyalkyl substituted by R17-phenyl, (R17-phenyl)alkyl substituted by —CO2alkyl, (R17-phenyl)alkyl substituted by —C(O)NH2, alkyl substituted by (R23-heteroaryl) and —C(O)NR37R38, R12-cycloalkyl, (R12-cycloalkyl)alkyl,

or R7 and R8 and the nitrogen to which they are attached together form a ring system selected from the group consisting of

p is 0 or 1;
q is 0 or 1;
the dotted line represents an optional double bond;
R9 is H, halo, alkyl, cycloalkyl, —CH2F, —CHF2 or CF3;
R10, R11, and R13 are independently selected from the group consisting of H and halo;
R12 is 1-3 substituents independently selected from the group consisting of H, alkyl, hydroxy, alkoxy, hydroxyalkyl, alkoxyalkyl, —C(O)Oalkyl, —(CH2)n—N(R30)—C(O)-cycloalkyl, —(CH2)n—N(R30)—C(O)alkyl, —(CH2)n—N(R30)—C(O)Oalkyl, —(CH2)n—N(R30)—(R23-heteroaryl), —(CH2)n—N(R30)—C(O)—NR18R19 and —(CH2)n—C(O)—NR18R19;
R14 is 1 or 2 substituents independently selected from the group consisting of H, OH, halo, alkyl, alkoxy, hydroxyalkyl, alkoxyalkyl, —CF3, CN, R17-phenyl, (R17-phenyl)alkyl, —NR18R19, alkyl-NR18R19, —(CH2)n—C(O)OH, —(CH2)n—C(O)Oalkyl, —(CH2)n—C(O)alkyl, —(CH2)n—C(O)(R35-phenyl), —(CH2)n—C(O)(R23-heteroaryl), —(CH2)n—C(O)NR18R19, —(CH2)n—C(O)N(R30)—(CH2)—(R23-heteroaryl), —(CH2)n—N(R30)—C(O)alkyl, —(CH2)n—N(R30)—C(O)-(fluoroalkyl), —(CH2)n—N(R30)—C(O)-(cycloalkyl), —(CH2)n—N(R30)—C(O)(R35-phenyl), —(CH2)n—N(R30)—C(O)(R23-heteroaryl), —(CH2)n—N(R30)C(O)NR18R19, —(CH2)n—N(R30)—C(O)Oalkyl, —(CH2)n—N(R30)cycloalkyl, —(CH2)n—N(R30)(R17-phenyl), —(CH2)n—N(R30)(R23-heteroaryl), —(CH2)n—N(R18)SO2alkyl, —(CH2)n—N(R20)SO2—(R17-phenyl), —(CH2)n—N(R30)SO2—CF3, —CH2S(O)0-2(R35-phenyl), —(CH2)n—OC(O)N(R23)alkyl, R23-heteroaryl, (R23-heteroaryl)alkyl, (R23-heteroaryl)oxy, (R23-heteroaryl)amino, —CH(OH)—(R17-phenyl), —CH(OH)—(R23-heteroaryl), —C(═NOR30)—(R17-phenyl), —C(═NOR30)—(R23-heteroaryl), morpholinyl, thiomorpholinyl,

w is 0 or 1;
or two R14 substituents and the carbon to which they are both attached form —C(═NOR30)— or —C(O)—;
each n is independently 0, 1, 2 or 3;
R15 is H, alkyl, cycloalkyl, (cycloalkyl)alkyl, hydroxyalkyl, alkoxyalkyl, —C(O)Oalkyl, —C(O)O(R30-cycloalkyl), -alkyl-C(O)O-alkyl, —C(O)O-alkylene-(R35-phenyl), R17-phenyl, (R17-phenyl)alkyl, —CH—(R17-phenyl)2, R23-heteroaryl, —(CH2)n—C(O)NR18R19, —SO2-alkyl, —SO2-cycloalkyl, —SO2—CF3, —SO2—(R35-phenyl), —SO2—NR18R19, —C(O)alkyl, —C(O)-(fluoroalkyl), —C(O)—C(CH3)(CF3)2, —C(O)—(R17-phenyl), —C(O)—(R23-heteroaryl), —C(O)-hydroxyalkyl, —C(O)-alkoxyalkyl, —C(O)—(R39-cycloalkyl), —C(O)-alkylene-(R17-phenyl), —C(O)-alkylene-(R23-heteroaryl), —C(O)-alkylene-S—C(O)alkyl, —C(═S)—(R17-phenyl), hydroxyalkyl substituted by R17-phenyl, hydroxyalkyl substituted by R23-heteroaryl, alkoxyalkyl substituted by R17-phenyl, alkoxyalkyl substituted by R23-heteroaryl,
wherein z is 0, 1 or 2;
R16 is 1 to 4 substituents independently selected from the group consisting of H, alkyl, R17-phenyl, (R17-phenyl)alkyl, (R23-heteroaryl)alkyl, hydroxyalkyl, alkoxyalkyl and —C(O)Oalkyl, or two R16 groups and the carbon to which they are both attached form —C(O)—;
R17 represents 1 to 3 substituents replacing a hydrogen on a phenyl moiety, each of which is independently selected from the group consisting of halo, alkyl, cycloalkyl, —OH, hydroxyalkyl, alkoxy, —CN, —CF3, —OCF3, —OCHF2,
—OCH2F, —C(O)OH, —C(O)Oalkyl, —C(O)O—(R35-phenyl), —C(O)alkyl, —C(O)—(R35-phenyl), —SOalkyl, —SO2alkyl, —SO2—CF3, alkylthio, —NR43R44, -alkyl-NR43R44 and heteroaryl; or two R17 substituents on adjacent carbon atoms together form —O—CH2—O—, —O—(CH2)2—O—, —(CH2)2—O— or —O—CH2—O—CH2—;
R18 and R19 are independently selected from the group consisting of H, alkyl, hydroxyalkyl, alkoxyalkyl, R17-phenyl and (R17-phenyl)alkyl;
R20 is H, alkyl, or cycloalkyl;
R22 is 1 to 4 substituents independently selected from the group consisting of H, alkyl, hydroxy, alkoxy, halo, —CF3, —NH2 and R35-phenyl;
R23 is 1 to 4 substituents independently selected from the group consisting of H, alkyl, hydroxy, alkoxy, halo, —CF3, —NR18R19, —CN, —C(O)Oalkyl, —NHSO2-alkyl and R35-phenyl;
R24 is H, OH or alkoxy; or when the optional double bond is present, R24 and the adjacent carbon atom form the double bond;
R25 is H or R35 phenyl;
R27 is 1 to 3 substituents independently selected from the group consisting of H, halo, OH, alkyl, alkoxy, hydroxyalkyl, alkoxyalkyl, —CF3, —CN, —C(O)OH,
—C(O)Oalkyl, —C(O)N(R30)(R18), —C(O)—(R36-heterocycloalkyl), R17-phenyl, (R17-phenyl)-alkyl, R23-heteroaryl, (R23-heteroaryl)alkyl, (R23-heteroaryl)oxy, (R23-heteroaryl)amino NR18R19, NR18R19-alkyl, —(CH2)n—N(R30)—C(O)alkyl, —(CH2)n—N(R30)—C(O)-(fluoroalkyl), —(CH2)n—N(R30)—C(O)alkoxyalkyl, —(CH2)n—N(R30)—C(O)(cycloalkyl), —(CH2)n—N(R30)—(R23-heteroaryl), —(CH2)n—N(R30)—C(O)—(R23-heteroaryl), —(CH2)n—N(R30)—C(O)O-alkyl, —(CH2)n—N(R30)—C(O)O—(CF3-alkyl), —(CH2)n—N(R30)—C(O)O—(R39-cycloalkyl), —(CH2)n—N(R30)—C(O)O-alkylene-cycloalkyl, —(CH2)n—N(R30)—C(O)—N(R30)(R20), —(CH2)n—N(R30)—SO2-alkyl, —(CH2)n—N(R30)—SO2—CF3, —(CH2)n—N(R30)—SO2—N(R30)2 and

or two R27 groups and the carbon to which they are both attached form —C(═NOR30)— or —C(O)—;
R28 is H, alkyl, R35-benzyl or -alkyl-C(O)O-alkyl;
R29 is alkyl, —C(O)Oalkyl, —C(O)alkyl, —C(O)cycloalkyl, —C(O)—(R17-phenyl), —C(O)—(R23-heteroaryl), —SO2-alkyl, —SO2—(R35-phenyl), —C(O)NR18R19, R35-phenyl, (R35-phenyl)alkyl or R23-heteroaryl;
R30 is independently selected from the group consisting of H, alkyl and R35-benzyl;
R31 is H, alkyl, R35-benzyl or phenoxyalkyl;
R33 is H, OH or alkoxy;
R34 is H, alkyl, hydroxyalkyl, alkoxyalkyl or —C(O)Oalkyl;
R35 is 1 to 3 substituents independently selected from the group consisting of H, halo, alkyl, OH, —CF3 and alkoxy;
R36 is 1 or 2 substituents independently selected from the group consisting of H, alkyl, R17-phenyl, alkoxyalkyl and —C(O)Oalkyl; or two R36 groups and the carbon to which they are both attached form —C(═NOR30)— or —C(O)—;
R37 and R38 are independently selected from the group consisting of H and alkyl, or R37 and R38 together are —(CH2)3— or —(CH2)4—, and together with the nitrogen to which they are attached, form a ring;
R39 is H, OH, alkyl, alkoxy, or CF3;
R40 is —OR30 or —NHC(O)alkyl;
R41 is H or —SO2alkyl;
R42 is —(CH2)n—(R35-phenyl), —(CH2)n—(R23-heteroaryl), —C(O)Oalkyl or —C(O)alkyl;
R43 and R44 are independently selected from the group consisting of H and alkyl; and
R45 is 1 or 2 substituents independently selected from the group consisting of halo, alkoxyalkyl, —CO2alkyl, R17-phenyl, R23-heteroaryl and cycloalkyl.
Compounds of Formula I can be prepared using synthesis procedures and synthetic schemes described in the above-referenced published applications, for example, on pages 25 to 32 of the '009 publication, and exemplified throughout the '062 and '009 publications. One example is the synthetic scheme shown on pages 26 to 28 of the '009 publication, summarized below as Scheme I.

Compounds of Formula I of particular interest include the compounds having the structure of Formulae IXaa and IXab (below),

Processes for preparing these compounds are described in, for example, published US patent application No. 2006/0106062 A1, published May 18, 2006 (the above-described '062 publication). In particular, the '062 publication describes a batch process for the preparation of the compound of Formula IXaa on pages 83 to 86 (preparative Examples 5 to 7, in preparation of the example compound 26-347, which is illustrated on page 193) and a process for the preparation of the compound of Formula IXab on pages 380 to 382 (preparative Examples 8 to 11 in preparation of the example compound 38-8, which is illustrated on page 383), each of which process is incorporated by reference herein in its entirety, and each of which is next described in further detail.
In addition, the compound of Formula IXab has been prepared in accordance with Scheme Ia.

With reference to Scheme Ia, preparation of the tri substituted oxazole of Formula Ia2-ester, by treatment of the compound of Formula Ia1 with the acid halide of Formula Ib1, or its related acid (Ia2-acid) prepared by hydrolyzing the ester functional group of the oxazole of Formula Ia2-ester, provides a product which contains high levels of unwanted side reaction products and shows poor utilization of the starting materials.
In the same manner, the compound of Formula IXaa can be prepared in accordance with Scheme Iaa, as described in the above-reference '009 publication beginning on page 145, Example 8 therein, and with reference to synthesis schemes on pages 26 and 27 therein.

As will be appreciated from the foregoing, a key step in the synthesis of PDE IV compounds of Formula I is illustrated in Scheme Ib (below), and shown in Step 2 in any of Synthesis Schemes I, Ia, and Iaa, which is the formation of an oxazole ring by acylating a quinolinyl intermediate compound, with reference to Scheme Ib, compound 10, using an acid fluoride acylating reagent (11) to provide the oxazoline-substituted quinoline compound (IV).

As described in the '009 publication, and illustrated in Scheme Ic, below, the acid fluoride acylating reagents (11), for example, with reference to Scheme Iaa, step 2, the compound of Formula 18a, wherein R3 and R5 are hydrogen, R4 is t-BOC, and R6 is t-butoxymethyl-, that are necessary to prepare these critical intermediates in accordance with these schemes are themselves prepared by treating the corresponding acid with toxic, unstable cyuranic fluoride (9), as illustrated in Scheme Ic.

As will be appreciated, when the acylating reagent is to be provided from an acid which contains functional groups that may be sensitive to unwanted side reactions under the conditions used to prepare the acylating reagent or under the acylation conditions, the sensitive functionality is converted to a protecting group before the fluorination and/or subsequent acylation reactions are carried out. This method requires handling of a hazardous and toxic reagent, the cyuranic fluoride. In addition to being a hazardous material, cyuranic fluoride is not available in lot quantities of a size suitable for commercial scale preparation of the acid fluoride intermediate.

Process and intermediates for the synthesis of 2-(quinolin-5-yl)-4,5 disubstituted-azole derivatives


Low-cost assay test strip readers enable creation of profiles of analyte reactions detected on an assay test strip utilizing a simple detector fixedly mounted to a body of the reader. The detector may be a single detector, such as a photodetector, which detects an optical signal at a single point. The assay test strip is inserted and/or removed from the test strip reader and the detector detects the optical elements of the strip during such insertion and/or removal. The movement of the test strip with respect to the body enables the detector to scan a length of the test strip, thereby generating a profile of optical signals representing analyte reactions along a one-dimensional portion of the test strip. The reader may convert the detected profile into a displayable indication of analyte concentrations for diagnostic purposes.

Assay test kits are currently available for testing a wide variety of medical and environmental conditions or compounds, such as for testing for the existence of a hormone, a metabolite, a toxin, or a pathogen-derived antigen. Most commonly these tests are used to enable medical diagnostics in the home testing context, the point of care testing context, or the laboratory context. For example, lateral flow tests rely on a form of immunoassay in which the test sample flows along a solid substrate via capillary action. Some tests are designed to make a quantitative determination, but in many circumstances the tests are designed to return or indicate a positive/negative qualitative indication. Examples of assays which enable such qualitative analysis include blood typing, most types of urinalysis, pregnancy tests, and AIDS tests. For these tests, with proper illumination, a visually observable indicator such as the presence of agglutination or a color change may indicate the result of the test.
Such assay-based tests can generally be divided into two categories. A first category includes assay-based tests in which, after the test sample flows along the solid substrate as noted above, the results of the tests (such as the colored or visible lines resulting from the test) are displayed or made visible to a human interpreter of the test. For example, a home pregnancy test may display one or more lines, wherein the perception by the human interpreter of a designated quantity of lines (such as two lines) indicates a positive outcome of the test (e.g., that the person taking the test is pregnant). Such tests can be inexpensive, but can also result in operator error or uncertainty by the human interpreter of the tests.
A second category of assay-based tests are tests which can be read by one or more opto-electronic assay readers. In such situations, a conventional assay strip-based test is read and/or analyzed by one or more opto-electronic devices. Such opto-electronic devices may utilize an optical detection technique to determine the concentration of particular analytes on the assay strip. These opto-electronic readers can vary in terms of the technology utilized to detect the results of the test. Generally, however, these opto-electronic devices are more expensive than their human-interpretable counterparts.
A first type of opto-electronic reader can include imaging-based opto-electronic readers. In such imaging-based readers, an array of detectors, such as a camera or other image detector, captures an image of a two-dimensional portion of the assay strip. For example, an image detector may include a CMOS or CCD image sensor which includes at least one semiconductor having a plurality of circuits that convert detected light to voltages. In such image sensors, circuitry on a silicon chip converts the voltages indicative of detected light into digital data representative of the sensed image. The device then applies known image processing algorithms to the captured image to accommodate certain imaging artifacts, such as mechanical tolerance artifacts or spatial non-uniformity artifacts. After the algorithms are applied, the circuitry analyzes the sensed image and outputs data indicative of a result. Such devices can also be modified to perform multiplexed tests, wherein a plurality of different portions of the assay strip are analyzed in the same test, and a result is determined based on each of the analyzed portions of the strip.
Known imaging-based readers suffer from certain drawbacks. Specifically, the cost associated with the optical detector and the supporting electronics required to analyze the image captured by the optical detector, such as a micro-controller with image processing capability, can be relatively high, and can prevent broad implementations of a consumer-based product utilizing such opto-electronic readers.
A second type of opto-electronic reader can include photodiode based opto-electronic readers. In such readers, one or more detectors of the reader is implemented as a photodiode, such as a PIN-diode, in which the amount of electricity flowing through the diode varies proportionately to the amount of optical signal detected, are used to collect data indicative of a representation of the results of the test as indicated visually by the assay strip. Corresponding circuitry implements one or more algorithms to analyze the amount of electricity flowing in the PIN-diode, and thus outputs or otherwise indicates the results of the assay test.
Photodiode-based readers also suffer from certain similar drawbacks to those discussed above with respect to imagers. While the circuitry required to drive known photodiode-based readers may be simpler than the circuitry required to drive similar imagers, and such readers may therefore be more cost effective than corresponding imagers, known photodiode-based readers suffer from drawbacks relating to their lack of scalability. Particularly, photodiode-based readers do not provide spatial information. For example, certain known PIN-based readers cannot differentiate between a plurality of visible lines on an assay strip. Other photodiode-based readers can differentiate between (and monitor) a plurality of different analyte regions on an assay strip only by including a plurality of immovable detectors in the form of a plurality of photodiode-diodes, with one detector corresponding to each potentially detected line. The cost and logistical issues associated with incorporating a plurality of photodiode-diodes in a single reader can thus be disadvantageous. Moreover, an existing reader with a plurality of detectors, implemented as a plurality of photodiode-diodes, may be limited to only analyzing assay test strips that detect the presence of certain types of analytes based on the static positions of the analyte regions, and thus based on the static positions of the detectors.
One known photodiode-based reader is implemented as the Clearblue® digital pregnancy test kit, manufactured and sold by SPD Swiss Precision Diagnostic. In this embodiment, two separate detectors (specifically, two separate PIN-diode based detectors) are positioned adjacent to a position associated with a control line and a test line, The qualitative result of the test (i.e., whether the provider of the sample for the test is pregnant), is based on which of these lines are visible following applying biological fluid to the assay test strip. Thus, while a plurality of lines of an assay test strip can be detected, the device is limited to tests which have analyte regions corresponding to the fixed positions of the photodiode detectors. Additional test lines require additional photodiode detectors, and thus are associated with additional costs and require development of different reader components.
To overcome the limitations of known photodiode-based readers attributable to the inability of such readers to simultaneously monitor a plurality of different portions of an assay test strip, certain known readers implement a single detector mounted on an electro-mechanical scanning mechanism. During testing, the scanning mechanism moves the photodiode of the reader across a stationary assay strip and provides a profile of an optical response representing analyte reactions along a one-dimensional portion of that assay strip. Most high-end commercial systems available today that utilize photodiode to monitor a plurality of different analytes contained in a single assay strip rely on such electro-mechanical scanning technology, wherein the scanner is driven by a stepper motor or other appropriate type of motor. However, such systems also suffer from certain drawbacks relating to the scanning apparatus' reliance on the stepper-motor. Such systems can be large, making portability difficult, and can be expensive, with costs ranging from two-thousand dollars to three-thousand dollars and upward.
Thus, it is desirable to create a portable, low-cost, stand-alone assay test strip reader which utilizes a single detector (or array of detectors) to detect the presence of a plurality of different analyte regions on the assay test strip without regard for the pattern of the analyte regions on the assay test strip.

Assay reader operable to scan a test strip


Disclosed are various embodiments of a weight scale with differential display. A first weight is determined for a user from a weight sensor. The first weight is stored in a memory. A second weight is determined for the user from the weight sensor. A difference is determined between the first weight and the second weight. The difference is communicated to the user through an output device.

The body weight or body mass of a person has many important health implications. Depending on his or her body weight, a person may be classified as, for example, severely underweight, underweight, normal weight, overweight, obese, or morbidly obese. Some of these categories are associated with greatly increased health risks. How much one weighs also can affect how society views the person and how the person views himself or herself. Thus, millions of people are currently seeking to lose body weight, each with an eye toward losing a certain number of pounds by diet and/or exercise.
Weight scales allow users to track weight gain or loss by allowing users to determine their current body weight, which may then be manually compared with the results of previous weighings. Additionally, weight scales allow users the ability to track their progress with a finer granularity than with mere physical appearance or how clothes fit.


A current mirror compensation circuit is disclosed herein which automatically adjusts the operating conditions of a current mirror so as to compensate for the voltage dependent current characteristics of a current load which a current mirror output is intended to match. In one embodiment, this compensation circuit compares a voltage level at the output of a current source with a voltage level at a corresponding node in the current programming portion of a current mirror. If a difference in these voltages is detected, the compensation circuit adjusts the current flow through the current programming portion of the current mirror to be equal to the output current through the current source. Therefore, since the current mirror output portion mirrors the current through the programming position, the currents through the output portion will match the current through the current source.

In an earlier patent application, Ser. No. 07/506,418, now U.S. Pat. No. 5,063,343, entitled "Current Pump Structure," a current matching circuit is disclosed similar to that shown in FIG. 1. This circuit of FIG. 1 consists of an output current source comprising transistor Q1 and resistor R1, a current mirror output portion comprising switchable transistors Q2 and Q3, and a current mirror programming portion comprising the circuitry within dashed-outline 12.
Basically, the current mirror of FIG. 1 operates to generate the same current through current mirror output transistors Q2 and Q3 (assuming diodes D1 and D2 are off) as is being generated through transistor Q5 by providing a same gate-source voltage to each of transistors Q2, Q3, and Q5. The current source comprising transistor Q4 and resistor R4 is used to match the output current source. In this way, ideally, the current supplied to output terminal 10 through transistors Q1 and R1 will be equal to the current sunk through either transistor Q2 or transistor Q3. By controlling diodes D1 and D2 to conduct or not conduct, a plus current, a minus current, or a zero current may be generated at output terminal 10.
This current matching circuit of FIG. 1 operates adequately for most purposes. However, for non-ideal output current sources, the current supplied to output terminal 10 will change as the voltage on terminal 10 increases. For example, when the depletion mode transistor Q1 is fabricated using Gallium Arsenide (GaAs) technology, the current flow through transistor Q1 is undesirably varied by a change in voltage at the source of transistor Q1 due to a change in voltage on output terminal 10. This effect on the current flow through transistor Q1 due to a change in voltage at the source of transistor Q1 is called backgating.
Backgating is a voltage related phenomena occurring in GaAs devices, which is similar to the body effect found in MOS devices. A negative bias on the substrate with respect to the source depletes the channel under a gate 5 further, such that a more positive potential is required on the gate to invert the channel and turn the device ON. The effect is a positive increase in the device threshold voltage V.sub.T necessary to the turn on the device.
In the depletion mode transistor Q1 of FIG. 1, serving as a current source, the drain voltage is fixed, and the gate and source nodes move with respect to ground and the substrate (tied to ground). Therefore, when the source voltage moves due to a change in voltage on output terminal 10, the current outputted by transistor Q1 will no longer match the current being sunk by either transistor Q2 or Q3.
As another example, MOS designers would experience the same problem (called body effect) if they used NMOS devices for VCC anchored current sources.
Thus, current source circuits (such as transistor Q1 and resistor R1) using GaAs or NMOS devices may undesirably produce an output current which varies with a change in an output voltage.
What is needed is a compensation circuit for a current mirror (such as the current mirror comprising transistors Q2 and Q3) which causes the current mirror to generate a current output which mirrors the voltage dependent behavior of a current load (such as the current source comprising transistor Q1 and resistor R1) which the current mirror output is intended to match.


A method for regulating sample surface charge has been proposed in this invention. The processes of applying a charged particle beam to a first area and applying a flood energized beam gun with gaseous molecules to a second area are executed in the method when the sample is in both continuous and Leap & Scan movements. The second area is located at a predetermined distance from the first area behind or ahead of the first area being scanned with respect to the movement of the sample. Thus, the surface of the sample may be regulated.

1. Field of the Invention
The present invention relates to a method for regulating scanning sample surface charge regulation during wafer inspection or review.
2. Background of the Related Art
Integrated circuit fabrication process uses various types of techniques, such as etching, deposition, and photolithography. Defects often introduced during those processes. Thus, semiconductor integrated circuit need to be inspected and defect need to be reviewed during the fabrication. Regulation of charging status on wafer surface is often needed for charged particle beam inspection and review tools.
Unbalanced charging on wafer surface can adversely affect subsequent fabrication, inspection or defect review processes. To reduce the adverse effects, a conventional pre-charging technique has been developed for SEM defect inspection and review. The pre-charging technique uses a flood gun to create strong and equalized charging on a substrate and its associated structure. The charging can reduce or eliminate the non-uniform distribution of electrostatic charges generated prior to and/or during the e-beam inspection or defect review. But the pre-charging technique may result in image distortions in gray scale, reduced image sensitivity and resolution, and time-dependent location-related differences due to non-uniform charge leakage.
Additionally, to reduce the adverse effect on fabrication or inspection processes, some conventional techniques have been developed to remove electrical charges. These conventional techniques include ionizer radiation and ultraviolet (UV) illumination. The ionizer radiation generates ionized air or gas molecules under the primary electron beam to neutralize electrostatic charges on wafer surface. But the ionizer air/gas under the primary electron beam can (1) lower image resolution and (2) hurt the high vacuum environment in primary beam column. Another conventional technique uses UV illumination. However, the irradiated semiconductor substrate often includes grounded conductive traces and the UV illumination technique usually cannot effectively neutralize electric charges far away from conductive traces.
Hence it is highly desirable to improve techniques for removing and neutralizing electrical charges on wafer surface, especially for e-beam wafer/photo mask inspection and defect review tools.

Method for regulating scanning sample surface charge in continuous and leap-and-scan scanning mode imaging process


An identification tag which includes a channel for receiving the base of a crimp pin assembly and wherein the channel is defined by opposing flanges having a slot therebetween through which portions of the pin assembly extend and wherein protrusions are provided adjacent the flanges for preventing the removal of the pin assembly once it is seated within the channel.

1. Field of the Invention
This invention is generally related to identification tags and badges of a type which are designed to be worn on an individual's clothing by securing the tag or badge using a lockable crimp pin or safety pin which is attached to the body of the tag. More specifically, the invention is directed to tags and badges which are formed of a molded plastic material and which include an integrally molded channel along the rear surface thereof in which the base of a crimp pin is slidably received to thereby securely lock the pin to the tag or badge.
2. History of the Related Art
Most conventional tags, badges, buttons or the like, are attached to an area of an article of clothing or wearing apparel such as a pocket or lapel by using safety or double lock crimp pins which are mounted to such items. The pins are designed to extend through a portion of cloth with the tip of the pin thereafter being retained from withdrawal or displacement by a U-shaped catch formed either integrally with the pin or extending from the body of the tag or badge. Unfortunately, most pins are mounted to tags and badges in such a manner that the pins are easily separated therefrom thereby destroying the usefulness of the tags and badges for future use.
U.S. Pat. No. 1,626,133 to Day discloses a badge having a cellulose body which is bent to provide front and rear panels having spaced openings therein through which portions of a safety or double lock crimp pin extend. There is nothing within the structure to retain the pin rigidly with respect to the cellulose material and therefore the pin may pivot relative to the material and may be easily displaced by pulling the pin relative to the body of the badge. Another type of badge or button design for attaching to wearing apparel is disclosed in U.S. Pat. No. 1,765,325, also to Day. In this patent a license or other object is designed to be mounted between a front portion and rear removable portion of a badge. A safety pin member may be positioned between the front and rear portions and is retained by frictionally engaging the rear portion of the badge within an annular flange which extends along the periphery of the front portion of the badge. The pin may be removed by frictionally disengaging the rear portion from the front portion and thus the pin can accidently be misplaced if the portions are accidently separated. Modifications of the button or badge are disclosed in U.S. Pat. Nos. 1,785,186, also to Day and United States patent 1,867,964 to Bott.
A different type of badge is disclosed in U.S. Pat. No. 214,296 to Draper et al. In Draper, the front of the badge has rearwardly extending flanges which slidingly receive a rear or back plate having a slot and an opening therein with the pin assembly being carried by the back plate. As with other prior art identification tags and badges, if the back plate is slidingly moved with respect to the front plate the pin assembly may be easily disengaged and accidently misplaced. A somewhat similar arrangement is shown in U.S. Pat. No. 2,357,231 to Sleeper, wherein the rear of the badge is slidingly received within the front portion of the badge and wherein the pin assembly is mounted through openings in the rear portion of the badge.
Another means of mounting a pin assembly to a badge is disclosed in U.S. Pat. No. 4,869,004 to Maloney. In this patent, the base portion of the pin assembly is adhesively secured to the back portion of the badge. Unfortunately, such adhesive arrangements do not adequately secure the pin assembly relative to the badge and the pin assembly can be easily removed from the badge.
Further examples of identification badges or display buttons and the like are disclosed in U.S. Pat. Nos. 2,232,060 to Foster; 3,559,318 to Sitzberger; and 4,021,575 to Kruger et al.


A method of controlling a display of a screen is provided. The method includes selecting a first image and a second image, selecting a masking pattern including at least one first area and at least one second area, measuring an inclination of the electronic device, and determining a part of the first image displayed in a screen corresponding to the at least one first area and a part of the second image displayed in a screen corresponding to the at least one second area, based on the measured inclination of the electronic device, and outputting the determined parts of the first image and the second image on a display unit.

In recent years, various electronic devices for convenience for users have been used. With the recent development of digital technologies, various portable electronic devices, such as mobile communication terminals, personal digital assistants (PDAs), electronic notes, smartphones, tablet personal computers (PCs), and smart watches, which can process communication and personal information processing while the users carry them, have been distributed.
The portable electronic device may include a display, such as a touch screen, in which an input function and an output function are combined such that the user can easily carry it. The portable electronic device may include displays of various sizes according to a function or purpose thereof.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.

Electronic device and method of controlling display of screen thereof


An occupancy sensor device has a sensor and a fastener. The sensor has a body and a connector. The body has a detector and a lens. The lens covers the detector. The connector is formed on the body. The fastener is connected securely to the connector of the sensor. When the occupancy sensor device is installed on a light, the connector is mounted through a sensor hole of a light cover first, and the fastener is connected securely to the connector. Then the installation is completed and the sensor device is mounted securely on the light cover. Because the sensor has the connector directly formed on the body and the connector can be connected securely to the fastener, the sensor device is easily mounted on various kinds of lights regardless of the structure of the base.

1. Field of the Invention
The present invention relates to an occupancy sensor device, especially to an occupancy sensor device that can be assembled with various types of light fixture.
2. Description of the Prior Arts
A conventional light is usually controlled its on and off status by operating the manual switch, but the switch is not always hygienic such that contacting the switch may contaminate the user's hand. For example, germs may gather on the switch and pass to the user's hand upon multiple users' contacts. Thus, lighting fixture with an occupancy sensor built-in is introduced for actuating the light without operating the switch.
With reference to FIG. 6, the conventional lighting fixture with an occupancy sensor has a base 91, a lighting element, a light cover 92 and a sensor 93. The lighting element, such as a light bulb or a light tube, is mounted on the base 91. The light cover 92 is mounted on the base 91, covers the lighting element and has a sensor hole 921. Since the sensor 93 cannot be fixed by itself, the most common way to fasten the sensor 93 is to mount the sensor 93 securely on the base 91. The sensor 93 protrudes through the sensor hole 921 of the light cover 92 for detection. When the sensor 93 detects any person approaching, the sensor 93 provides signals to the lighting element and then the lighting element is turned on. After the person leaves the range of detection of the sensor 93, the lighting element is turned off automatically to save energy. Therefore, the user can turn on or off the light without touching anything. Besides, turning the light off automatically also saves energy.
The sensor 93 is mounted securely on the base 91 by welding or screwing. The base 91 has some through holes or threaded holes. However, the sensors 93 and the bases 91 of different brands may have different installation standards. For example, the position of threaded holes or the distances between the threaded holes may be different in the bases 91 of different brands. Therefore, if the sensor 93 is broken, the user must buy a new sensor 93 with totally the same installation standard so that the new sensor 93 could be mounted on the base 91, which causes inconvenience. Furthermore, if the sensor 93 of the specific installation standard is out of production, the user has to buy a new base 91 to replace the original and unbroken base 91 as well, which further wastes money and is not eco-friendly.
To overcome the shortcomings, the present invention provides an occupancy sensor device design for fixture integration and a light with the same to mitigate or obviate the aforementioned problems.

Occupancy sensor device design for fixture integration and a light with the same


A method of forming a VNW SRAM device with a vertical cross-couple/PD/PU contact landed on a PD/PU gate and a bottom nRX and pRX interface and the resulting device are provided. Embodiments include forming a first and a second bottom nRX and pRX over an NW upon a p-sub, the pRX formed between the nRX; forming fins over the first nRX, the first pRX, the second pRX, and over the second nRX; forming a first GAA perpendicular to and over the second pRX and nRX, a second GAA perpendicular to and over the first nRX and pRX, a third GAA perpendicular to and over a portion the first nRX, and a fourth GAA perpendicular to and over a portion of the second nRX; and forming a first and a second metal gate contact on the first GAA, nRX, and pRX and on the second GAA, pRX, and nRX, respectively.

Cell scaling is of critical importance to continued improvement of complementary metal-oxide-semiconductor (CMOS) technology. A VFET is a promising device to enable device scaling beyond the 5 nm technology node. To achieve the requisite small SRAM cell, vertical nanowire (VNW) contacts are employed. However, forming vertical cross-couple gate contacts at this scale poses a number of known process and structural challenges.
A need therefore exists for methodology enabling formation of a cross-couple/pull down (PD) transistor/pullup (PU) transistor contact to achieve a small SRAM cell without the known process and structural challenges and the resulting device.

VNW SRAM with trinity cross-couple PD/PU contact and method for producing the same


An optical module includes a photoelectric conversion element optically connected to an optical fiber, a plate-shaped substrate mounting the photoelectric conversion element, coupling members fixed to both end portions of the substrate so as to sandwich the photoelectric conversion element, and a cover member coupled to the substrate by the coupling members so as to cover at least a portion of the substrate.

1. Field of the Invention
The invention relates to an optical module which transmits signals through an optical fiber, and a signal transmission medium using the optical module.
2. Description of the Related Art
An optical module is known which is provided with a photoelectric conversion element for converting electrical energy into optical energy and vise versa, and transmits or receives signals through an optical fiber (see JP-A-2008-9333).
JP-A-2008-9333 discloses an optical interconnection module provided with an optical device transmitting or receiving light to or from an optical fiber, a flexible substrate mounting the optical device and a shielding case formed of a sheet metal to house the flexible substrate and the optical device, wherein the flexible substrate is folded along an inner surface of a sidewall of the shielding case such that the optical device faces an end face of the optical fiber.

Optical module and signal transmission medium


In a method of manufacturing a semiconductor device, a first photoresist layer is applied on a polycrystalline silicon layer formed on a semiconductor substrate. The first photoresist layer is then patterned and cured with UV rays. The polycrystalline silicon layer is etched, using the first photoresist layer as a mask, to form a gate electrode and a resistive film of the polycrystalline silicon layer. A second photoresist layer is applied on the cured first photoresist layer and patterned to form an opening portion exposing the first photoresist layer. Impurities are ion implanted through the opening portion in the polycrystalline silicon layer. The channeling of impurities implanted during the ion implantation is suppressed by the cured first photoresist layer.

1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a method of manufacturing an ion-implanted impurity layer with respect to a pattern of a polycrystalline silicon layer in a self-alignment manner.
2. Description of the Related Art
Self-alignment formation of impurity layers with respect to a pattern of a polycrystalline silicon layer is used for, for example, forming impurity layers of source/drain regions of transistors in manufacturing of conventional MOS transistors, which includes the following steps.
First, as illustrated in FIG. 2A, for example, an element isolation insulating film 12 and a gate insulating film 13 are formed on a silicon substrate 11. Subsequently, a polycrystalline silicon layer 14 is formed on the entire surface of the silicon substrate 11, and photoresist is then applied thereon. The resultant is exposed with a photomask corresponding to patterning of the polycrystalline silicon layer 14, to thereby form a first photoresist layer 15.
Next, as illustrated in FIG. 2B, the polycrystalline silicon layer 14 is removed by etching with the first photoresist layer 15 being a mask material, to thereby form gate electrodes 14-1 and 14-2 and a resistor 14-3 of the polycrystalline silicon layer 14, and wiring is formed. The first photoresist layer 15 is thereafter removed.
Next, as illustrated in FIG. 2C, a second photoresist layer 16 is patterned so that a source and a drain of a MOS transistor including a desired electrode, for example, the gate electrode 14-1 may be formed in desired regions. Source/drain impurity layers 17 are then selectively formed by ion implantation.
At this time, the opening portion of the second photoresist layer 16, through which ion implantation of impurities is performed, is formed not only above the desired source/drain regions of the MOS transistor, but also above the gate electrode 14-1. Thus, the gate electrode 14-1 functions as a mask for ion implantation, thereby enabling the source/drain impurity layers 17 to be formed to the gate electrode 14-1 in a self-alignment manner.
Manufacturing MOS transistors through those steps has the following advantages.
(1) It is not necessary to take misalignment between source/drain impurity layers and gate electrodes in photoresist pattern processing into consideration, and hence transistors can be miniaturized.
(2) It is not necessary to form a photoresist pattern for source/drain impurity layers needlessly finely, and hence at least the source/drain impurity layers can be formed more easily.
As described above, such a MOS transistor is formed that includes the source/drain impurity layers formed to the gate electrode pattern of the polycrystalline silicon layer in a self-alignment manner.
In addition, as illustrated in FIG. 2D, as needed, the above-mentioned step of FIG. 2C is repeatedly performed on desired regions in a MOS transistor including, for example, the gate electrode 14-2 as its electrode, to thereby form source/drain impurity layers 18 so that a plurality of kinds of MOS transistors can be formed.
MOS transistors including source/drain impurity layers formed in a self-alignment manner and methods of manufacturing the MOS transistor are well known. For example, in Seigo Kishino, "Basic VLSI material and process", Ohmsha, Ltd., Dec. 25, 1987, pp. 11-12, there is disclosed a method of forming a source/drain impurity layer of a MOS transistor through the above-mentioned steps.
However, the following problems are found in the method of manufacturing a MOS transistor disclosed in Seigo Kishino, "Basic VLSI material and process", Ohmsha, Ltd., Dec. 25, 1987, pp. 11-12.
A polycrystalline silicon layer, which is generally used as gate electrodes of transistors, is formed of an aggregate of single crystal grains. Thus, due to a channeling phenomenon in which implanted impurities pass through gaps between grains during ion implantation of source/drain impurities, impurities penetrate gate electrodes formed of a polycrystalline silicon layer, with the result that the impurities are also implanted into channel regions of transistors, which are formed in a silicon substrate and located below the gate electrodes.
This is a cause of greatly varying impurity concentrations of the channel regions, each of which is one important factor for determining a threshold of the transistor, and thus hinders stable transistor performance.

Method of manufacturing a semiconductor device


A solid lubricant application procedure is combined in-line with a steel strip processing method which comprises processing steps upstream and downstream of the lubricant application procedure. The latter comprises applying the lubricant material in molten form or as a solution and may include temperature adjusting steps both upstream and downstream of the lubricant material-applying step. The space for incorporating the lubricant application procedure into the steel strip processing line is limited. The strip speed in the lubricant application procedure is synchronized with the strip speed normally attained in the steel strip processing method in the absence of an in-line lubricant application procedure. The steps of the lubricant application procedure are constrained to accommodate the space limits and strip speed synchronization requirement imposed on the lubricant application procedure when it is combined in-line with the steel strip processing method.

The present invention relates generally to the application of a solid lubricant on steel strip and more particularly to the combination of a lubricant application procedure in-line with a method for processing steel strip.
When a steel strip is subjected to a fabricating operation, such as stamping or drawing, it is desirable for the steel strip to have a film of lubricant thereon, as that facilitates the fabricating operation. Generally, the lubricant film can be either solid or liquid, but solid lubricant films have advantages over liquid films, and solid lubricant films are preferred.
When a solid lubricant is applied to steel strip, the lubricant is applied in the form of a liquid, either in molten form or as a solution. The solid lubricant application procedure can be in-line or external. In-line application refers to application during processing of the steel strip in the steel mill, as distinguished from external application in which the solid lubricant is applied at an external processing line separate and apart from a steel mill processing line. External application requires transportation and handling (and the equipment and manpower associated therewith) over and above that employed with in-line processing, thereby substantially increasing the time, effort and money involved.
There are certain problems which must be overcome should one attempt to retrofit existing steel mill strip processing lines to incorporate in-line application of solid lubricant. One cannot merely incorporate a conventional external application procedure into an existing steel mill processing line. This is because a conventional external application line can occupy a relatively large amount of space which is not available in existing steel mill strip processing lines. Moreover, in existing steel mill strip processing lines, the steel strip moves along the processing line at a relatively rapid speed, and in-line solid lubricant application equipment desirably should be synchronized to operate at the same speed. A solid lubricant application procedure not only incorporates the step of applying the solid lubricant to the surface of the steel strip, but also it generally incorporates a thermal treatment step for the steel strip either upstream or downstream of the solid lubricant-applying step, or both. In-line application of solid lubricant requires incorporating all of these processing steps (and the equipment for performing them) into the steel mill strip processing line, while (1) accommodating those steps and equipment to the space limitations in the steel mill strip processing line, (2) synchronizing the speed of the lubricant application procedure to the relatively rapid speed at which the steel mill strip processing line is operated and (3) allowing enough flexibility in the design of the solid lubricant application equipment to accommodate both hot melt and solution-based solid film lubricants.
Examples of solid lubricants for steel strip and of procedures for applying the solid lubricant are described in Coduti, et al., U.S. Pat. No. 4,999,241 (wax type solid lubricant), Robbins, et al., U.S. Pat. No. 5,151,297 (acrylic polymer solid lubricant) and Sech U.S. Pat. No. 4,753,743 (wax type solid lubricant); the disclosures in all of these U.S. patents are incorporated herein by reference.
The Coduti, et al. patent teaches preheating a steel strip to which a wax lubricant is to be applied in molten form; the strip preheat temperature is 5.degree. to 10.degree. F. above the melting point of the wax. (The melting point for wax lubricants is typically in the range 120.degree.-150.degree. F. (49.degree.-66.degree. C.)). The higher the strip preheat temperature, the more difficult it is to accommodate the strip preheating step (and any subsequent cooling step) (a) to the space limitations in the steel strip processing line and (b) to the strip speed synchronizing requirement, imposed upon the lubricant application procedure when one attempts to combine that procedure in-line with a method for processing steel strip in an existing strip processing line.

In-line application of solid lubricant to steel strip


A cup lid for use with a beverage cup comprising a peripheral flange to fit over a cup rim and a central portion containing a reclosable access closure flap selectively movable between an open and closed position having a pull tab formed on one end portion thereof and a hinge formed on the opposite end portion thereof and a first retainer element such that when the reclosable access closure flap is moved from the closed position to the open position the reclosable access closure flap engages the first retainer element to releasably retain the reclosable access closure flap in the open position.

1. Field of the Invention
A cup lid comprising a reclosable access closure flap selectively movable between a closed and open position and a first retainer element disposed to engage the reclosable access closure flap when in the open position to releasably retain the reclosable access closure flap in the open position.
2. Description of the Prior Art
Cuplike containers for coffee, soft drinks or other beverages often are provided with lids to cover the contents before and during use. Such lids may thermally insulate the contents and assist to exclude dust, hair, insects, leaves or other contaminants. Lids to cover such contents usually are flanged peripherally to fit down over the cup rim, which is often rolled or beaded to retain the lid securely but removably. Simple or multiple recessing of one or more regions of laminar lids is commonly practiced for structural reinforcement of what otherwise would be too flexible for the desired use.
Consumers often prefer to access the contents with minimal disruption of the lid so as to maintain such protection as long as desired. Hence, such lids often include openable access closures, whether integrally formed or added thereonto. Such access closures often include part of the flange that mates the lid to the cup rim.
Because throw away items pollute the environment, the popularity of non-removable access closures is increasing. However, some captive closures have the disadvantage of being obtrusive when open, or failing to stay shut when reclosed. Favored are access closures, integral with the lid, that stay open when opened and stay shut whenever reclosed. Reclosable access closures with various means for holding them in a fully open position are disclosed in various prior art.
U.S. Pat. No. 4,322,015 discloses a pair of tear impressions that define an access strip therebetween. After assembly of the lid on a container, the access strip is pulled back from the rim of the lid along the tear impressions to create ready access to the contents. The access strip may be reclosed to the container to prevent spillage during transport or motion of the container and further to preserve the thermal state of the contents
U.S. Pat. No. 4,473,167 teaches a polymeric container lid comprising a reclosable access strip defined between a pair of spaced apart tear impressions extending inwardly from the edge of the lid into the central portion thereof and a self-forming hinge element for the access strip together with a hold-open retainer by which the access strip can be releasably retained in the open condition.
U.S. Pat. No. 3,994,411 shows a lid for drink cups including a drinking flap of limited circumferential extent that may be pivotally opened and closed. The drinking flap may initially be defined by frangible lateral edges in the lid and may be held in the open position by the pull tab on the flap being inserted in a slit for a straw orifice.
U.S. Pat. No. 4,202,459 teaches a disposable cup cover including a separable pie shaped mouth piece which a user can bend out of the way in order to drink from the cup with an edge that will mate with a slot and to hold the mouth piece until it is desired to close the cover again.
U.S. Pat. No. 4,741,450 discloses a lid for a drinking cup or other container wherein the lid has a restricted opening through which the contents of the container may be drunk while leaving the lid in position to prevent spillage. The opening is covered by a flap which may be integral with the lid and separated therefrom by break or tear lines. The flap when folded back on the hinged line opposite the rim of the lid to reveal the opening, is automatically caught against the outer surface of the lid away from the opening so that it will not interfere with drinking from the cup and so that any reason for tearing off the flap and discarding it separately from the cup is removed.
An additional example of the prior art is found in U.S. Pat. No. 4,629,088 and U.S. Pat. No. 4,738,373.