Rev-matching techniques that do not require a gear position sensor or a clutch position sensor are provided for a manual transmission of a vehicle. The techniques include predicting an intent of a driver to shift gears of the manual transmission based on whether the vehicle is accelerating or decelerating; predicting a shift of the manual transmission from a current gear to a different target gear based on the predicted driver intent; and detecting a trigger condition indicative of the predicted shift of the manual transmission based on a position of a clutch pedal configured to control engagement/disengagement of a clutch of the manual transmission. In response to detecting the trigger condition, a torque request for the torque generating system is modified to obtain a modified torque request, and the torque generating system is controlled based on the modified torque request.

A manual transmission of a vehicle is operable by a driver and configured to transfer torque from a torque generating system (e.g., an engine) to a drivetrain. The driver selects a gear of the manual transmission and controls engagement/disengagement of a clutch of the manual transmission. When shifting from a current gear to a different target gear, a rotational speed of the torque generating system should be adjusted to be equal to or approximately equal to a rotational speed of an output shaft of the manual transmission in the target gear. This process is known as "rev-matching." If rev-matching is not performed, the vehicle could experience a jolt or other disturbance as the clutch engages due to the difference in rotational speeds, which could be uncomfortable for the driver. Because rev-matching is difficult for the driver to perform manually, there exist automatic rev-matching systems. These systems typically utilize at least one of a gear position sensor and a clutch position sensor to perform rev-matching. These sensors, however, increase costs of the vehicle. Thus, while such automatic rev-matching systems work for their intended purpose, there remains a need for improvement in the relevant art.

Rev-matching without gear or clutch position sensors


One or more firewalls are used to perform firewall functionality on packets based on the entry and exit accesses of each of the one or more firewalls being applied to a packet. For example, when firewalls are included in a router, the interfaces of the router are typically mapped to virtual firewalls and access thereof. Based on the determined routing of a particular packet, the firewalls to apply and their corresponding entry and exit accesses are identified. In order to decouple the application by the firewall itself of the security policies from the network topology and routing architecture (e.g., the network routing address information which is typically relied upon by current firewalls), the firewall functionality is defined based on the identified entry and exit accesses of a firewall, rather than based on network defined addresses, for example.

The communications industry is rapidly changing to adjust to emerging technologies and ever increasing customer demand. This customer demand for new applications and increased performance of existing applications is driving communications network and system providers to employ networks and systems having greater speed and capacity (e.g., greater bandwidth). In trying to achieve these goals, a common approach taken by many communications providers is to use packet switching technology. Increasingly, public and private communications networks are being built and expanded using various packet technologies, such as Internet Protocol (IP). Note, nothing described or referenced in this document is admitted as prior art to this application unless explicitly so stated.
Firewalls are currently used in networks to protect malicious and innocuous traffic from reaching different portions of the network. These firewalls can be standalone appliances or incorporated in packet switching devices (e.g., routers, switches, etc.). In either case, prior art systems may use physical and/or virtual firewalls. A physical firewall has physical interfaces on which packets are received and sent from and then the firewall functionality which acts on these packets. A virtual firewall has virtual interfaces (e.g., buffers, memory locations, other data structures) in which packets are available for processing by the firewall functionality. In other words, packets are virtually received when made available on the virtual interface, then processed by the firewall functionality, then virtually sent when forwarded or made available for processing by another part of the appliance (e.g., processed by a physical or virtual router). One way of looking at it is that a virtual firewall is an implementation/emulation of a physical firewall, much in the same manner that a computer system can emulate another one or more computer systems, or a router can emulate multiple routers—which is often referred to in the industry as multiple virtual routers. Additionally, just as multiple virtual routers can be implemented in a single router box, multiple virtual firewalls can be implemented in a single appliance.
For example, shown in FIG. 1 is a prior art conventional configuration of a network which includes a router with firewall 100 between a public Internet 110, a private enterprise network 120, and a publicly available portion 125 of the enterprise network. Firewall (100) prevents connections from being established between public Internet 110 and private enterprise network 120 that are initiated from public Internet 110, while allowing such connections if initiated from private enterprise network 120. Similarly, firewall (100) prevents connections from being established between publicly available portion 125 of the enterprise network and private enterprise network 120 that are initiated from publicly available portion 125 of the enterprise network, while allowing such connections if initiated from private enterprise network 120. Also, firewall 100 does not block connections between public Internet 110 and publicly available portion 125 of the enterprise network.
Current firewalls operate based on a knowledge of the topology of the network in which they are used in order to perform their functionality, and perform its functionality based on network addresses, such as, but not limited to, Internet Protocol (IP) and media access control (MAC) addresses. For example, in the configuration illustrated in FIG. 1, firewall router will receive and process routing information including routing updates in order to maintain its knowledge of the network topology. Thus, changes to the topology of the network require updates to the firewall, and the programming of the firewall functionality is based on a knowledge of these network addresses.

Packet firewalls of particular use in packet switching devices


A package for an optoelectronic device having an optical fiber in communication therewith. The parts of the package are generally of polymer material, preferably engineering thermoplastic, which is assembled to the fiber having the device mounted on a printed circuit board type material, FR4. The adhesion process of the individual parts of the package is done typically through a solvent bonding or an epoxy curing process that is done at room temperature, thereby eliminating the drawbacks of soldering at high temperature which has the attendant disadvantage of built in stress and thermal expansion resulting in misalignment of the individual parts. The related packaging technique greatly reduces the requirements of active alignment of the fiber to the device in the packaging of the device and fiber. Accordingly, the overall cost of the device is reduced by virtue of the reduced cost of the parts of the package as well as the process for fabrication of the package.

The present invention is related to U.S. Pat. No. 5,594,237, to Kulick et al., the disclosure of which is specifically incorporated herein by reference. Fiber to the Home (FTTH) is gaining a great deal of approval in the telecommunications industry, and accordingly there is a need to have a large quantity of optoelectronic devices to effect the communication to and from the home. However, as with most industries cost in the CATV industry is a great driver in the design of the components of the CATV market. While the devices used in the CATV industry may well have experience a reduction in cost, and an increase in performance, one of the major sources of cost in the industry is the required packaging of the devices. To this end packaging is often a substantial factor in the cost of the end product. To this end in the fiber to the home industry, where most packaging of photodetectors is in metal and particularly brass, the cost of the packaging is often proving to be prohibitive for large scale use, particularly to the individual home.
The standard practice for packaging of photodetectors and other optoelectronic devices has been to have a ceramic substrate having the device mounted thereon, and the ceramic substrate mounted in a metal, typically brass, housing. The various elements of the package are thereafter soldered and effect the package device thereby. The cost of the packaged device is driven generally by two factors, the cost of the individual parts and the cost of complex fabrication. The cost of the parts such as brass and a ceramic substrate, are generally much higher than alternatives, and the alignment as well as soldering techniques are generally complicated and thereby expensive. Accordingly what is needed is a packaged product that is lower in cost through the intrinsic cost of the individual parts, as well as lower in cost due to a much less complex packaging process.


A flat, flexible electrochemical cell is provided. The within invention describes various aspects of the flat, flexible electrochemical cell. A printed anode is provided that obviates the need for a discrete anode current collector, thereby reducing the size of the battery. An advantageous electrolyte is provided that enables the use of a metallic cathode current collector, thereby improving the performance of the battery. Printable gelled electrolytes and separators are provided, enabling the construction of both co-facial and co-planar batteries. Cell contacts are provided that reduce the potential for electrolyte creepage in the flat, flexible electrochemical cells of the within invention.

Flexible planar thin batteries utilizing lithium-based chemistries are known wherein the electrodes are formulated by the deposition of an active material film onto a substrate using various deposition techniques such as pulsed laser deposition, spin coating and sputtering. These techniques tend to require relatively costly and complex equipment and do not lend themselves to a high throughput inexpensive manufacturing process. Further, many devices requiring a power supply, such as novelty packaging and greeting cards augmented with audio and/or visual outputs, are manufactured on high speed web-based printing lines. Lithium-based technologies are not an attractive power source for such low cost per unit applications. The ability to produce both the device and the power supply in a single process presents opportunities for cost savings. There is therefore a need to develop an inexpensive electrochemical power supply that can be produced in a web-based process by stenciling, screen printing or other thick film application processes. As used herein, "print" and "printing" and "printable" refer to any such thick film application process whereby the layer produced is between 10 and 250 microns thick and includes both stenciling and screen printing processes.
It is therefore an object of the within invention to provide a printable zinc ink that can be printed directly onto a nonconductive substrate without the need for a distinct anode current collector.
It is a further object of the within invention to provide a printable zinc ink that can be printed directly onto a flexible nonconductive polymer substrate without the need for a distinct anode current collector.
It is a further object of the within invention to provide an electrochemical cell with a printed anode, a printed cathode current collector, a printed cathode and a printed separator/electrolyte.
It is a further object of the within invention to provide an electrochemical cell with a printed zinc anode, a printed manganese dioxide cathode and a printed metallic cathode current collector in an electrolyte comprising zinc chloride.
It is a further object of the within invention to provide an electrochemical cell with a printed zinc anode, a printed manganese dioxide cathode and a printed metallic cathode current collector in an electrolyte comprising zinc acetate.
It is a further object of the within invention to provide an electrochemical cell with an anode printed onto a first flexible polymer substrate, a cathode current collector printed onto a second flexible polymer substrate, a cathode printed directly onto the printed cathode current collector, wherein said first and second flexible polymer substrates are subsequently joined together to form a battery housing or package.
It is a further object of the within invention to provide an electrochemical cell with an anode and a cathode current collector both printed directly onto a first piece of nonconductive substrate material in a coplanar arrangement, a printed cathode printed directly onto the cathode current collector and where a second piece of substrate material is subsequently joined with the first together to form a battery housing or package.
It is a further object of the within invention to provide a carbon zinc electrochemical cell with at least one electrode printed onto a nonconductive substrate and a printable gelled polymer electrolyte that also functions as a separator.
It is a further object of the within invention to provide an alkaline electrochemical cell with at least one electrode printed onto a nonconductive substrate and a printable gelled polymer separator.
It is a further object of the within invention to provide an electrochemical cell with at least one electrode printed onto a nonconductive substrate, where said substrate forms a flexible battery housing or package and current flows between the interior of said package and the exterior of said package using discontinuous tabs in order to assure electrochemical compatibility between the external tab and the internal cell chemistry, to allow for a more robust external tab development and to reduce the potential for electrolyte leakage through the package or housing seal.
It is a further object of the within invention to provide a printable gelled zinc chloride electrolyte that is particularly suitable for use in cells having printed co-planar electrodes.
It is a further object of the within invention to provide a device powered by such a printed flexible battery and having one or more printed components.

Flexible thin printed battery and device and method of manufacturing same


Method and system for causing a powder sample in a sample holder to undergo at least one of three motions (vibration, rotation and translation) at a selected motion frequency in order to present several views of an individual grain of the sample. One or more measurements of diffraction, fluorescence, spectroscopic interaction, transmission, absorption and/or reflection can be made on the sample, using light in a selected wavelength region.

Many analytical instruments require a powder sample: to control the shape and/or volume of the specimen; to increase the surface area of the specimen; to increase the statistical representation of a specimen when samples are not homogeneous with regard to the characterized property; and/or to increase the statistical representation of the specimen spatial orientation when the properties being characterised are not equivalent in different viewing directions.
In one embodiment of the invention, the instrument is an X-ray diffraction apparatus, as the invention is particularly suited to X-ray instruments that utilize small X-ray beams, such as non-focused or miniature X-ray diffraction instruments.
The powder sample handling technique would also find application with instruments using techniques other than X-ray diffraction. Non restrictive examples of such application are listed herein:
X-ray fluorescence: the analysis consists in measuring the X-ray emission spectrum of the sample when the sample is irradiated by X-rays. If selected energies or white (continuous) X-rays are used to illuminate the sample, inner electrons shells of the constitutive atoms can be excited and emit X-ray radiation at characteristic wavelengths. Measuring the emission spectrum allows identifying the nature and abundance of the constitutive atoms. The powder handling system would be used to insert the sample in the analysis region and randomize the sample during analysis. This would enable complete automation of the analysis with no need to prepare pellets of the powder sample usually done.
Infrared absorption spectroscopy: the analysis consists in measuring the absorption (attenuation) of infrared light passing through a sample depending on the wavelength of the radiation. Chemical bonds in the sample can vibrate at particular frequencies (i.e. with particular energies) and consequently can absorb particular electromagnetic energies. As a consequence, measuring the energies (or wavelength) that are absorbed by a compound allows identification of chemical bounds and in turn identification of the compound. Powder samples are typically used and are ground to fine grain (<2 μm) to limit scattering of incident light. The sample is analyzed in a solid or liquid matrix for index matching. The powder handling technique could be applied to either dry sample, or preferably powders sample in suspension in an appropriate liquid. The sample handling technique would ease manual loading of the sample and enable automatic/robotic operation of the infrared spectrometer. It would also allow randomization of samples and analysis of large quantities of material, or analysis of a stream of material.
Raman spectroscopy of powder sample: Raman spectroscopy consists in the measurement of the wavelength of backscattered radiation of a sample illuminated by a monochromatic radiation usually produced by a laser. Identification of particular wavelength shifts (Raman shift) allows identification of the compound, based on its particular molecular vibrations and/or its crystalline vibrations. The powder handling system can be used in conjunction with a Raman spectrometer to allow automatic loading of powder in the spectrometer, randomize the sample during analysis, and analyze a larger quantity of powder that would be analyzed by conventional techniques.
Microscopic imaging of powder sample: The powder handling system would be used to load the sample in the imaging region of a microscope. Imaging can be done in reflection or transmission mode, on dry powders or with the sample placed in suspension in a liquid.
Imaging particle size analyzer: The powder sample is vibrated for insertion in the imaging region consisting of two windows separated with a distance of the order of the diameter of the largest grains of powder. The vibration amplitude is adjusted so that the grains of powder have a level of excitation spreading them apart. When the vibration is stopped, the grain motion stops. An image of the sample is then collected, in reflection or, preferably, in transmission mode, using a camera equipped with high magnification optics or mounted on a microscope. The image collected is transferred to a computer equipped with an image analysis software that characterizes the size and shape of the grains observed on the image. The sample is then vibrated to randomize the sample. Vibration is stopped and a new image is acquired. After analysis of a sufficient number of images, size and/or shape distributions of the sample are obtained by summing the data of individual image analysis.
However, one of the most demanding analytical techniques, with regard to preparation of powder sample for analysis, is XRD.
XRD, the most common technique for studying crystal structures, is applied in many fields such as geology for identifying minerals, material sciences for studying materials structures and quantifying structural strain, biochemistry for studying macromolecular structures and identifying pharmaceutical compounds, archaeology for investigating localities and processes of fabrication of artifacts, as well as many other applications.
XRD relies on the measurement of the angles at which crystalline matter constructively reflects X-rays from a set of atomic layers defined by the crystal structure. Each crystal structure has a set of possible reflections that occur when the crystal is appropriately oriented in an X-ray beam. Measuring all the possible reflections of a sample in an angular range allows determination of the sample crystalline structure, or the actual sample identification based on its crystalline structure.
Performing an XRD analysis requires exploring all the possible orientations of a crystal and measuring the conditions at which reflections occur within a practical angular range. One approach is to use a single crystal that is rotated in an X-ray beam to expose all possible orientations, but this is mechanically complex, and in terms of size for remote locations, is very impractical.
The most common approach of XRD, called powder diffraction, uses powder material, or solid polycrystalline material, to create a specimen that offers all possible crystalline orientations without requiring complex sample movement. It is assumed that the specimen is composed of a large number of crystals, identical in structure and oriented in all directions so that all of the possible orientations leading to the reflection of X-rays are statistically well represented. Quality powder diffraction data can only be obtained with fine grained powders (less than about 10 μm in diameter), because relatively fine grains such as these lead to a better statistical representation of the crystal orientation within the finite volume exposed to the incident radiation. This is the case for all powder diffraction instruments, but is particularly important for instruments for which the volume of material under X-ray illumination is very small, such as miniature instruments and instruments that are not based on focused/parafocused geometries. These instruments are very sensitive to the grain size of the powder, with the quality of the data being dramatically altered as the grain size increases.
Grinding the material down to an ideal grain size is sometimes impossible, and conditioning the sample for analysis is often time consuming and labor intensive. Further, for operation in remote or extreme environments, neither of these approaches are acceptable.

Powder handling device for analytical instruments

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration


A system and a method of using the system for reproducibly cutting a cove using a table saw are presented. The system comprises a first fence assembly and a fixturing means, where the fence assembly is rotatably affixed to the fixturing means, wherein the fixturing means can be releasably secured to the table of the table saw. The method comprises providing a blank molding, a table saw having a table and saw blade, and the cove system and releasably affixing the cove system to the table. The method further comprises setting a fence angle using the first fence assembly and setting a fence depth by adjusting the position of the fixturing means with respect to the table. The method finally comprises feeding the blank molding over the saw blade thereby cutting a cove in the blank molding.

A cove molding has a concave-profile and is often used at the junction of an interior wall and ceiling, on furniture, and for picture frames for art, though it is often used as a design element in various other applications. Because of its elegant look, cove molding is a favorite of architectural and other professional designers. However, the prior art methods of making a cove molding on a table saw requires complicated, and sometimes unsafe, set-ups which are difficult to reproduce if additional molding is needed at a later time. The most common prior art method involves clamping a board or other straight-edged material to the table saw with the blade raised to the cove final cut height and adjusting this fence's location by trial and error. The saw blade is then lowered to just above the saw table surface. Using the auxiliary fence to position the molding blank, the cove is formed by making multiple passes of the molding blank over the saw blade, each time raising the blade approximately 1/16″ until the final cove depth and width are achieved. In actual practice, the first problem encountered is the structure of the underside of a saw's table casting. Either it is cast as a ribbed item, or it may be cast with other features that impede secure clamping of the fence. Also, clamping at the front of the saw table must accommodate the variation from the top of the saw table to the top of the fence guide rail which is lower than the table top. Many older table saws use a round bar as the fence guide rail, which further complicates clamping by requiring a V-block and other fixturing. The back of many saw tables has little or no area sufficient for solid clamping of the trailing edge of the temporary fence. Also, any adjustment of the fence requires re-setting the clamping, blocking, and shimming at both the front and the back of the saw table.
To cut an open cove molding, where the cove is cut only on the front portion of the blade, involves a cumbersome process requiring lowering the blade, placing the fence above the blade, turning the saw on, raising the blade to the height of the cove cut, cutting through the fence in the process, and performing a test cove run. If further adjustment is required, all the steps must be repeated for each adjustment, and with each adjustment another cut is introduced to the fence. This cumbersome, time consuming process discourages most woodworkers. Additionally, reproducing a previously produced molding in the future requires going through all the above steps again.
Jigs utilizing a parallelogram design for producing straight housed coves of limited width and depth are commercially available. Within this narrow range such jigs perform reasonably well, but often in architectural and furniture crafts, open and housed profiles are required in a flat and vertical orientation, and often require matching inside and outside curved profiles in both horizontal and vertical orientations. Such commercially available jigs are not able to produce such coves. To achieve these alternative coves even in large industrial shops requires many different machines and specialized tooling, thus making them expensive and impractical.


An electronic component package for containing a plurality of electronic components. The package including structure that provides at least two configurations. In the first configuration, the package functions as a sufficiently rigid tray for supporting and protecting the plurality of components during storage, shipping and handling of the package. In the second configuration, the package functions as a flexible carrier tape for feeding the components into and through automated component handling and placement equipment. The structure includes package edges interconnected to and extending along a plurality of tray sections in which the components are housed. In one embodiment, the package edges connect to a cover to provide the first rigid tray configuration. In another embodiment, the package edges include flexible edge wings that rotate into position and are secured to provide the first rigid tray configuration.

This invention relates to packaging for electronic components, particularly to trays and tapes used for shipping, storage, automated feeding and pickup of electronic components.
There are numerous packaging formats currently available for electronic surface mount and leaded components, such as connectors, transformers, speakers, and integrated circuits (IC""s). These packaging formats include bulk packaging (placement in bags or bins), single or multi-lane tubes, paper tapes, standard EIA carrier pocket tapes, thermoformed trays, and injection molded trays (JEDEC standard, matrix trays, or gel packs). All of these current packaging methods have limitations relating to cost, usability with current automated loading, feeding or pick-and-place equipment, protection of the components, and/or lead time for adaptation to different component configurations. In addition, the ability to reuse and/or recycle the packaging are also issues of concern.
A need exists for electronic component packaging that: can be standardized; works with automated equipment that is available or easily modified; protects the components within the package during storage, shipping, and handling; and can be produced and used at a reasonable cost.
The present invention is an improved electronic component package. The package of the present invention, when in a first configuration, functions as a sufficiently rigid tray capable of supporting and protecting a plurality of electronic components housed within the package. With such rigid support, the electronic component package may be stacked, boxed, shipped, stored, transported and fed while still protecting the electronic components within compartments of the package. When in a second configuration, the package of the present invention functions as a flexible carrier tape capable of conforming to a radius when passed over a roller, such as a drive roller. With such flexibility, the package may be readily fed into and through automated component feeding and placement equipment.
The electronic component package includes a plurality of component-receiving tray sections having leading and trailing edges which are flexibly interconnected to one another. Each component-receiving tray section is open on a top side. Thus, the electronic component package functions as a flexible carrier tape that conforms to a radius when passed over a roller by flexing between the tray sections. The package also includes first and second package edges interconnected to and extending along the tray sections. The first and second package edges are removably connectable to a cover over the top side of the tray sections. The electronic component package is sufficiently rigid when covered to function as a tray that supports electronic components located within the plurality of component-receiving tray sections and protects the electronic components during handling and storage of the electronic component package. The first and second package edges include tape-to-tray structure that provide for the two configurations described above.
In one embodiment, the package edges cooperate with the cover to provide the first configuration of sufficient rigidity, and provide the second configuration of flexibility when not cooperating. In other embodiments, the package edges include flexible edge wings that rotate into position and are secured to provide the rigidity, but provide the flexibility when outwardly extended.

Electronic component package for standard and odd form components


The extermination of imported fireants is accomplished by a process in which water, heated to a temperature in the range of 200 212.degree. F., is applied by impulse inundation within the central core region of a fireant mound, initiated below ground level, continuing as the probe is inserted to a lowermost region, and thereafter continuing as the probe is withdrawn, and repeating the process from different angles and orientations.

1. Field of the Invention
The present invention relates to the problem of eradication of troublesome colonies of insects, and more particularly, to extermination of the species of imported fireants termed "Solenopsis invicta" and "Solenopsis richteri."
2. Background of the Prior Art
Imported fireants (order Hymenoptera, Family Fomicidae, species "Solenopsis invicta" and "Solenopsis richteri") are extraordinarily aggressive, destructive insects capable of significant environmental damage, as well as inflicting human and animal suffering in the parts of the country which they inhabit. Imported here accidentally from South America sometime before World War II, these terroristic insects have now spread at an alarming rate across some 216,000,000 acres of land in 15 Southern States. They are steadily migrating northward and eastward each year.
These seemingly indestructible insects have been responsible for an estimated 300,000,000 human stings a year, sometimes severe enough to result in death, particularly in young children and the elderly. Fireants show no fear and will savagely attack and kill any ground dwelling insect and have been known to kill animals as large as cows. Farmers have suffered great economic loss as a result of damaged farm equipment, mutilated crops, and lost livestock.
Relying on a phenomenal reproductive capacity, thousands of "worker ants" are born to a "queen" over just a few days. The worker ants then proceed to build large ant mounds with interconnecting tunnels. The mounds may be found in yards, school playgrounds, open fields, and along roadways, often in concentrations as high as 400 mounds per acre. The mounds range in size from a few inches to several feet in diameter, and sometimes extend to below ground depths of up to six feet. Lateral tunnels often radiate outwardly to an average of perhaps 75 feet and a maximum of 130 feet. These tunnels have entrances and exits to and from the surface which the fireants use in their foraging excursions.
Efforts at control have had only limited success. In the past efforts have concentrated mainly on the use of environmentally hazardous chemical pesticides and baits which are not target specific and which have detrimental ecological effects. In addition, chemical control has been limited in achieving lasting success because of the rapid reproduction and replenishment of fireant colonies.
In the patent literature, typical examples of techniques that confront the problem include U.S. Pat. No. 4,756,118, issued Jul. 12, 1988, to Charles W. Evans, II. The Evans patent discloses a high pressure, high temperature vaporizing system and an insertable probe or lance mechanism together with other associated elements. By these means thermal vapors or gases comprising principally insecticides and diluents are injected into the core of a mound while maintaining a high pressure and temperature. The theory is that dispersion of the insecticide gases will carry through the entire mound and a substantial part of the tunnel system, destroy the queen and all fireants with which the gases come in contact. However, this approach not only relies primarily on the killing power of the insecticide, with its attendant expense and ecological after effects, but presents inherent dangers in terms of the ranges of temperature (2210.degree. F.) and pressure (as high as 3000 psi) that are used. The volume of liquid delivered is kept low, because reliance is placed on the spread of the killing gases.
Other patents evidencing the state of the art include U.S. Pat. No. 4,160,336, issued to Query et al. Jul. 10, 1979. This proposes a technique in which a refrigerant and an insecticide are injected as an aerosol into the individual mounds. As with the Evans II patent, the usage of an insertible probe for dispersion of vapors is not an assured method of delivery, since a mound comprises a plurality of interior tunnels and galleries. In addition, if the probe is not fortunately positioned, the flow may be occluded and have very limited or only partial penetration. The same is true of the U.S. Pat. to Turner, No. 4,367,161, issued Jan. 20, 1987. This is a probe system that utilizes pressurized steam injection, employing a probe that is injected vertically downward into the mound within a proprietary doomed shield with a vent opening. The patent suggests that condensation of a portion of the injected steam into very hot water will aid in the extermination of target insects or animals, but it is evident that only a very limited amount of water can be delivered in this manner. The U.S. Pat. to Connelly, No. 4,815,234, issued Mar. 28, 1989 proposes a combination of mechanical destruction of the ant bed, combined with delivery of a stream of high temperature fluid, which might include water, to kill the fireants. However, fireants are extremely sensitive to disturbing influences, and at the onset of danger the ants transport the queen or queens to different areas. Thus, in an area where there is a substantial concentration of ant mounds, such mechanical disruption has a possibility of being ultimately effective only with the first mounds so treated.
It is evident therefore that a need exists for methods and apparatus which can operate effectively to destroy fireant populations using ecologically safe materials of low cost, overcoming the problems that have been encountered by the prior art.

Method and apparatus for extermination of imported fireants


A vehicle having a horizontal transport platform or bed with steps mounted within the horizontal platform. The vehicle comprises a horizontal platform supported three to four feet above ground by wheels. The platform is reinforced by longitudinal I-beams. In accordance with the present invention, a rectangular opening is provided at the rear of the platform. The opening is positioned between adjacent longitudinal I-beams. The opening contains one or more steps that descend from the level of the horizontal platform to just above ground level. The steps are within the perimeter of the platform. To maximize transport area on the horizontal platform, a cover is provided for the platform opening. The cover is attached by a hinge along one side of the rectangular opening in the horizontal platform.

1. Field of the Invention:
This invention relates to tractor trailer beds, truck beds and the like, and more particularly to a vehicle having a horizontal transport platform or bed with steps mounted within the horizontal platform.
2. Related Prior Art:
Horizontal transport platforms on vehicles are well-known. Examples of these include city trucks, the trailer portion of semi-trucks and various forms of tow behind trailers. In each of these cases, platform height is determined by wheel diameter. In some instances, wheel diameter may be on the order of four feet, in which instance the platform height exceeds four feet. These high platforms make it difficult to load and unload materials from the platform. In addition, as platform height increases, there is a danger of cars sliding under the rear of the platform and possibly decapitating the operator of the vehicle. Various solutions to these problems have been advanced in the prior art.
A first category of solutions involves external steps fixed permanently to the rear of the platform. U.S. Pat. No. 4,266,817 issued on May 12, 1981, to James L. Mason and entitled Rear Step Bumper; U.S. Pat. No. 2,660,454 issued on Nov. 24, 1953, to Counerilth and entitled Combined Rear Trailer Bumper and Step; U.S. Pat. No. 3,708,198 issued on Jan. 2, 1973, to Coons and entitled Convertible Trailer Porch and Camper; and Design Pat. No. 267,166 issued on Dec. 7, 1982, to Sambucetti et al and entitled Semi-Trailer all disclose external fixed steps. The steps are rigidly attached to the rear portion of a horizontal platform on, respectively, a pick-up truck bumper, a city truck, a trailer porch, and a trailer. Each of these patents disclose a means for providing access to an elevated transport platform, but require that the overall length of the vehicle be increased in order to provide this access.
A second category of prior art patents solve the problem of platform access without adding length to a transport platform. They do this by adding a retractable set of steps to the transport platform. The steps and the retraction thereof, however, are a complex and expensive addition to the platform. Examples of this teaching are U.S. Pat. No. 3,858,905 issued on Jan. 7, 1975, to Peebles and entitled Demountable Safety Ladder With Handrail; U.S. Pat. No. 2,779,525 issued on Jan. 29, 1957, to Vogel and entitled Truck Extension Ladder; U.S. Pat. No. 2,544,799 issued on Mar. 13, 1951, to McCann entitled Yielding Vehicle Step; and U.S. Pat. No. 7,591 issued on Aug. 27, 1850, to Burdett and entitled Carriage Step. Each of these patents disclose retractable steps in the rear portion of, respectively, a house trailer, a city delivery vehicle and a carriage. The problem with these steps is that they are expensive and difficult to manufacture, require labor each time they are used to retract and deploy them, and the steps can be damaged due to their flexible design.
There remains a need for providing access to transport platforms without increasing the length of the platform or the expense, complexity and labor associated with retractable steps.


An optical film fabrication method, an optical film and a head-mounted display are provided. The optical film fabrication method comprises: providing a substrate having a curved surface; dispensing a photo-alignment (PAM) layer on the curved surface of the substrate and exposing the PAM layer to spatially-uniformly polarized light; dispensing a birefringent material layer on the PAM layer; and curing the birefringent material layer to form a birefringent film on the curved surface. An optic axis orientation of birefringent material molecules in the birefringent film are spatially uniform across the birefringent film.

The present disclosure generally relates to head-mounted displays (HMDs) and, more particularly, relates to a method to fabricate waveplates on a curved surface and curved waveplates thereof to increase the freedom of lens design in HMDs.
Currently, head-mounted displays (HMD) for virtual-reality (VR) and/or augmented-reality (AR) and/or mixed-reality (MR) applications have design criteria to be compact and light weight, and have high resolution, large field of view (FOV), and small form factors. An HMD generally have a display element that generates image light that directly passes through a lens system to reach a user's eyes. The lens system includes multiple optical elements, such as lenses, waveplates, reflectors, etc., for focusing the image light to the user's eyes, among which waveplates such as quarter-waveplate or half-waveplates are often used as polarization management components in the lens system.
To produce a large FOV, optical elements in the lens system often require high optical curvature. However, traditional waveplates are often flat, and using such waveplates on the optical elements of high curvature is rather difficult due to challenges of laminating a flat film on a curved surface. The disclosed fabrication method and waveplates thereof are directed to solve one or more problems set forth above and other problems.

Waveplates on a curved surface and fabrication method thereof


A lamp (34) for a refrigerator or freezer cabinet is located forwardly and above a horizontal edge (38) of an access opening (16) to a storage space (12) for goods in the cabinet. The lamp (34) illuminates the space (12) through the access opening by means of a reflector (36). The reflector (36) includes a cylindrical part (52) having a semi-elliptical cross-sectional shape. A concave side of the cylindrical part (52) faces the access opening (16). The lamp has a filament (42) which shines in the shape of a line (44) running parallel to the edge (38) and through one (42) of the focal points of the ellipse. The other focal point (58) of the ellipse is located quite close to and outside the edge (38), so that the light from the filament (42) first is reflected by the cylindrical part (52) of the reflector (36) and then passes through the other focal point (58) on its way into the space (12).

The invention relates to a refrigerator or freezer cabinet with a lamp which, by means of a reflector with a cylindrical reflection surface, illuminates a storage space for goods in the cabinet, and wherein the lamp is arranged ahead of and above a horizontal edge of a vertical access opening to the space and illuminates the space through the access opening.
Such a cabinet is shown in U.S. Pat. No. 2,153,851. In the '851 patent, the reflector has an inverted-U cross-sectional shape. A tubular lamp, which is not specifically described in the '851 patent, is surrounded by the reflector. From FIG. 2 of the '851 patent, it appears that the reflector directs more light outside the access opening than in through the access opening.
Accordingly, there exists a need in the art for an improved illumination means for the space within the refrigerator cabinet.

Lighting arrangement at a refrigerator or freezer cabinet


Improved control for the separation of waste materials, or materials having waste components, is provided by the injection of air, or other gas bubbles, into a water-filled tank while simultaneously depositing the waste containing material to be separated onto the top of the water. This method is especially useful where both portions of some or all of the materials to be separated from each other have specific gravities greater than that of pure water. The rapidly rising air bubbles provide turbulence and buoyancy to materials that are slightly heavier than water, such as water-soaked organic products, but do not prevent heavier materials, such as sand and metals from sinking. An apparatus is described which allows for the removal of both the floating and sinking fractions from the floatation tank. The cleaner separation provided by this method increase the value of both fractions for a variety of beneficial uses including manufactured products, a renewable-resource fuel which will reduce the generation of greenhouse gases, chemical product feedstock and compost.

1. Field of Invention
This invention relates to the separation of waste ingredients from a mixture of materials, including, but not limited to, mixtures of waste materials, specifically by aerating the mixture in a water-filled floatation container.
2. Description of Prior Art
Prior to about 1960, the disposal of waste material was of little concern to the public at large. Household garbage was dumped at any out-of-the-way spot on land that was not needed for some other purpose. Leaves and other yard wastes were simply burned at the generation site or in the street, instead of being composted. Apartment building operators in large cities simply burned their garbage in an incinerator located in the building. Both the soot and the odors were very noticeable. However, over the past thirty-five years, the generation of waste materials has been viewed as both a costly disposal nuisance and as an opportunity to recover some value from reuse of the waste materials. The incentive to find uses for the components of waste has been further enhanced by recognition that when all or a portion of a waste material can be used again, added value is also gained by avoiding the alternative cost of disposal. The most effective uses of the waste ingredients contained in mixed waste materials, such as Municipal Solid Waste (MSW), require that at least a partial separation of these waste materials be effected. For example, even if the primary reuse of the ingredients is as fuel for the purpose of generating energy, a better result is achieved if a large portion of the non-combustables and water are removed prior to the remainder being used as fuel. Where the ingredients of a waste mixture are to be reused for the same or another similar beneficial use, the value of the separated components are increased in accordance with the completeness of the separation. For example, metals designated for recycling should be free from other contaminants and, likewise, fibers which are to be reconstituted to new higher-value paper-like products need to be cleaner than when the same fibrous materials are used as raw fuel products. Also, the more completely that individual ingredients can be separated from mixed waste materials, the lower the disposal cost of residuals. For example, even though non-metallic inorganic waste material, such as sand and grit, may have a low intrinsic value, if that material can be made free of prutricables and organic material in general, it can be used for low-cost construction fill, rather than having to incur the alternative higher cost of sanitary landfill disposal. It is understood that landfills are not permanent disposal options. Many old landfills are leaking toxic materials to the groundwater, which has required that they be excavated and processed a second time for disposal. Thus it can be seen that there is an economic incentive to develop and employ improved methods of separating waste materials. This incentive has been increasing at a rapid rate in recent years, because disposal costs to sanitary landfills and mass-burn incinerators have increased disproportionately to the general economy, due primarily to more stringent environmental regulations.
A comprehensive review of past art, from publications and from patents that have been granted, shows that a wide range of methods have been employed for the separation and removal of waste materials from mixed wastes, including but not limited to Municipal Solid Waste (MSW). These methods can be categorized as follows: 1) manual separation, 2) screening, either before or after comminution, 3) contact with an upwardly moving air stream, 4) electromagnetic and optical, and 5) floatation in a liquid medium, including water. These methods have been employed both singularly and as systems which combine two or more methods.
In addition to the manual separations performed by MSW generators (i.e. the general population) through the mandatory curbside recycling programs, many commercial systems also rely on manual separation as the primary method of MSW processing for the recovery of specific ingredients. For example, U.S. Pat. No. 4,859,211 to Moore discloses a process in which MSW is manually sorted to separate materials of different value and degrees of contamination, including a portion which is processed to produce a fuel pellet. Likewise, U.S. Pat. No. 5,250,100 to Armbristor discloses a manual sorting technique wherein a large portion of the separated waste is directed to a composting operation. Manual sorting can provide very clean separations if performed at the source by the individual generators; however, this method causes high collection costs and places unnecessary burdens on the population. Manual separations of wastes after they have been co-rmingled (allowed to mix) are very labor intensive, generally expensive, viewed by some as a demeaning activity, and are not very effective in dealing with the removal of cross contamination (i.e. providing clean products).
The application of physical screening to effect MSW ingredient separation is based on experience that the non-combustable ingredients in MSW tend to be of smaller physical size than combustables. For example a piece of glass or dirt is usually smaller than a sheet of newspaper or cardboard. Therefore, if after the application of some mechanical action to expose the components of bagged material, the entire MSW is screened, the fraction which is composed of larger sized pieces will have a lower non-combustible content than the other fraction. The fraction containing the larger components can then be further processed to produce a refuse derived fuel (RDF) or some other beneficial use. For example, U.S. Pat. No. 5,101,977 to Roman discloses a multiple screening approach to MSW separation. Likewise, U.S. Pat. No. 4,479,581 to Kelyman, U.S. Pat. No. 4,561,860 to Gulley et. al., and U.S. Pat. No. 4,778,116 to Mayberry all disclose mechanical screening as a key component of their MSW processing systems. While it is true that selective screening will generally result in two fractions with different ratios of combustible to non-combustible fractions than the starting composition, unless further processing is employed, both portions separated by the screening method are generally only useful for low value applications, such as low-quality (dirty) fuel and compost.
Many of the largest commercial MSW separation operations have utilized some sort of air floatation apparatus for the separation of useable ingredients. For example U.S. Pat. No. 3,524,594 to Anderson et al, U.S. Pat. No. 3,738,483 to MacKenzie, U.S. Pat. No. 3,836,085 to Brown, U.S. Pat. No. 3,925,198 to Eckoffet al, U.S. Pat. No. 4,070,203 to Nollet, U.S. Pat. No. 4,210,527 to Patterson et al, and U.S. Pat. No. 4,264,352 to Houser all disclose apparatuses that use an upward flow of air to separate the ingredients of mixed waste into two or more portions. This method is very effective for some separations, such as separating a chunk of glass or a heavy metal object from lighter materials, such as paper and plastic items. The two principal disadvantages of air-float separation (where the objective is specifically to separate organic from inorganic materials) are that this method 1) does not effectively prevent buoyant inorganics, such as aluminum foil, and imbedded dirt from being carried along with the desired organic-rich portion, and 2) the heavier particle inorganic residue portion has a high organic content which makes it unsuitable for such applications as construction fill.
Electro-magnetic devices are commonly used to separate metals from mixed waste. Iron and most grades of steel can be extracted from a mixture of materials with a conventional magnet. Following the removal of magnetic materials, other electrically conductive material, such as aluminum, copper and non-magnetic stainless steel, can be removed using an eddy-current separator. These devices are very effective in removing metal from mixtures of other materials; however, they have no effect on the separation of non-conductive materials, such as the removal of sand and glass from paper, plastic and other organic wastes. These electromagnetic devices are usually used in combination with other separation methods. For example, U.S. Pat. No. 5,341,935 to Djerf et al and U.S. Pat. No. 5,387,267 to Warf disclose magnet separation followed by eddy current separation to remove metals from mixtures of waste materials. Optical scanners have been used, with apparent limited success, to separate glass from other mineral materials.
A summary of the commercial application of the above referenced approaches to waste separation methods has been provided by the U.S. Department of Energy in a Argonne National Laboratory publication, Practical Applications of Sizing, Separation, Homogenization and Densification Equipment in the Refuse-Derived Fuel (RDF) Industry, Oscar O. Ohlsson, et. al., presented at the AIChE 1992 Summer National Meeting, August, 1992.
Floatation in liquids, including water, is one of the oldest recorded methods of separating materials having different specific gravities. For example, U.S. Pat. No. 1,298,577 to Sawyer et al in 1919 discloses the separation of gold from sand using a device that allows heavier gold to settle out of a moving water stream, in which the sand remains suspended. Likewise, U.S. Pat. No. 1,548,971 to Ziska in 1925 discloses the separation of rocks from wood chips by using an apparatus which subjects the mixture of wood chips and foreign particles, such as rocks and nails, to an upward flow of water. The inventor, Ziska, specifically notes in his patent that an upward flow of water is necessary to prevent water-soaked wood chips from sinking along with the foreign particles that are being removed from the bottom of the floatation apparatus. Since the granting of U.S. Pat. No. 3,159,353 to Atwater in 1964, there have been numerous patents issued which describe modified approaches to the separation of mixed waste materials using liquid floatation methods. Examples of U.S. Patents, which employ water floatation to separate the ingredients in Municipal Solid Waste, include U.S. Pat. No. 3,568,839 to Dunlea, U.S. Pat. No. 3,597,308 to Brooks, U.S. Pat. No. 3,897,215 to Davidson et al, U.S. Pat. No. 4,250,023 to Samis et al, and U.S. Pat. No. 5,387,267 to Warf. In each of these cases the stated objective is to obtain a complete separation of organic material, including paper, textiles, wood, plastic and food waste from inorganic materials, such as metals, glass, sand and dirt in order to produce a low ash content fuel or compost material. However, unlike Ziska in his method for cleaning wood chips, none of these disclosures, with the exception of Brooks, recognize that most fibrous organic materials will also sink in water (when they become water-soaked) along with many types of plastic, unless some method of increased buoyancy is provided. Brooks recognizes three specific gravity categories associated with float separation in water; however, he uses a screw device rather than an upward flow of water to increase the buoyancy of organic materials having a higher specific gravity than that of water. Warf, on the other hand, asserts that all organic materials in mixed waste float while the inorganic materials sink, which is not usually the case. The incomplete separation, which results from traditional water-floatation methods, will both reduce the total recovery of useful organic materials and cause the sunken inorganic residue to be contaminated by organic material, such that it may require expensive landfill disposal rather than beneficial construction fill use.
Another approach to the use of water to separate fibrous organic materials, such as paper, from undesirable inorganic material is to first comminute or disintegrate the fibrous material by the high-speed wet shearing action of a hydro-pulper. The disintegrated material, along with only small particles of grit, are extracted in slurry form through the small holes of a perforated plate in the bottom of the hydro-pulper. Most of the remaining grit in the paper slurry can then be removed by conventional liquid cyclones. These liquid cyclones separate high specific gravity particles from the remaining mixture of water and lower specific gravity materials. If the hydro-pulper feed contains materials that do not disintegrate by the wet shearing action, such as the metals, plastic and glass (such as found in MSW), these materials will not pass through the perforated plate of the hydro-pulper and are periodically removed from the main chamber of the hydro-pulper. This method of separating waste materials was first disclosed in U.S. Pat. No. 3,549,092 by Baxter and assigned to the Black Clawson Company. Subsequently several other patents disclosing modifications and improvements of this method have been granted and assigned to the Black Clawson Company. These include: U.S. Pat. Nos. 3,595,488 and RE28,677 to Blakey et al. and 3,945,575, RE29,156, and 4,049,391 to Marsh. U.S. Pat. No. 4,026,678 to Livingston also includes hydro-pulping as a part of a process to produce fuel pellets. Commercial operation of this method by the Black Clawson Company is described in a 1974 EPA publication Recovering Resources from Solid Waste Using Wet Processing, EPA 530/SW-47d and on pages 225, 226 and 305 of the book Solid Waste: Engineering Principles and Management Issues, authored by George Tchobanoglous, et al, and published by McGraw Hill in 1977. The use of a hydro-pulper as a first step in a waste separation process is also described in a magazine article, "The Next Generation of Waste-to-Energy", Solid Waste Technologies, pg. 40, September/October 1997. It can be noted from these literature references that in the commercial application of this wet comminution method, no separation of waste materials was employed prior to the waste material being fed to the hydro-pulper. The fiber separated from Municipal Solid Waste (MSW) by this process in the Black Clawson commercial demonstration operation was used primarily as the paper mat foundation for asphalt roofing shingles. By using multiple liquid cyclones after the hydro-pulping, a very clean, low-ash fiber was produced. However, because there was no separation of abrasive materials, such as glass and metals, prior to the hydro-pulping operation, reduced capacity and high maintenance costs of the hydro-pulper were incurred. A hydro-pulper operates like a giant under-the-sink garbage disposal, which can be progressively damaged by including hard materials, such as glass and metal, with the food waste.

System for separating waste materials by enhanced water floatation


A variable gain amplifier includes a Gilbert cell multiplier cell having a pair of bipolar input transistors and a pair of bipolar output transistors. A bias circuit provides a first bias current to the input transistors and a second bias current to the output transistors, the ratio of the second to the first bias current determining the gain of the multiplier cell. The bias circuit couples the first and second bias currents to the emitters of the input and output transistors and references these currents to ground, which provides excellent supply rejection. Additionally, high beta immunity is achieved by increasing the ratio of the second bias current to the first bias current by subtracting a current from the first bias current substantially equal to the base currents of the output transistors.

1. Field of the Invention
The invention relates generally to gain control circuits of the type having a transconductance multiplier circuit biased by a bias circuit. More particularly, the invention concerns a variable gain amplifier ("VGA") with high beta immunity and supply voltage rejection suited for low voltage applications.
2. Description of the Prior Art
Gain control circuits are generally known and have widespread used in the electronic arts. With the increasing popularity of mobile and hand held computing and/or communicating devices, such as cell phones, laptop computers, and personal digital assistants, there is an increased need for gain control circuits which can withstand the supply voltage variations which commonly occur in battery operated devices. Additionally, in order to reduce power consumption, it is desirable for such gain control circuits to operate with low supply voltages, such as on the order of 3.5-5 volts.
Of particular usefulness are gain control circuits which allow the gain to be varied continuously. FIG. 1 shows a known circuit in the form of a bipolar Variable Gain Amplifier (VGA), which employs a Gilbert cell multiplier circuit 100. This circuit is known from the text: B. Gilbert, Analog IC Design, The Current-Mode Approach, Chapter 2 (United Kingdom 1990). The Gilbert multiplier circuit 100 (FIG. 1(a)) includes a pair of differentially coupled input transistors Q1A, Q1B and a pair of differentially coupled output transistors Q2A, Q2B. The collectors of the transistors are coupled to a supply 10. A differential input signal current is supplied to the bases of the two input transistors via the two input terminals 2 and 3. Each of the input transistors has a common base/collector and thereby function as diodes to convert the input current into a voltage at their respective bases/collectors. This voltage is then reconverted into a current at the output terminals 4 and 5 by the output transistors Q2A and Q2B. The emitters of the input transistors Q1A, Q1B are biased by a first bias current 2*I1 while the emitters of the output transistors Q2A, Q2B are biased by a second bias current 2*I2, both supplied by the bias circuit of FIG. 1(b).
The bias circuit of FIG. 1(b) includes a first current mirror consisting of the current mirror transistors Q3, Q4. The collector of the transistor Q3 serves as the input of the first current mirror 110, and is fed by a current source 101. The output of the current mirror 110 is coupled to the collector of the transistor Q4, and is related to the current provided by the current source 101, by a factor N, the current mirror ratio. Similarly, the second bias current is output by a second current mirror 120 consisting of the current mirror transistors Q5, Q6 fed by a second current source 102.
For this Gilbert cell, it is known from the above-mentioned text that the current gain between the common base/collector terminals of the input transistors Q1A, Q1B (the differential input current) and the collectors of the output transistors Q2A, Q2B (the differential output current), equals the ratio of the collector bias currents of the input and output transistors. Assuming infinite .beta.'s, this leads to the following current gain A.sub.i between the input and output terminals ##EQU1## where i.sub.out and i.sub.in, are the differential output and input currents, I.sub.c2 is the sum of the collector currents of the transistors Q2A, Q2B, and I.sub.c1 is the sum of the collector currents of the input transistors Q1A, Q1B. Similarly I.sub.e2 and I.sub.e1 are the sum of the emitter currents of the output and input transistors, respectively. Note that the right hand equality also holds for non-infinite .beta.'s. .beta. is defined as the common collector/base current amplification factor of a bipolar transistor.
The relative simplicity of the Gilbert cell in FIG. 1 and its predictable control characteristic have made the circuit a popular choice in bipolar intermediate frequency (IF) VGA circuits.
An important disadvantage surfaces, however, with real transistors that have non-infinite .beta.'s. Especially at high gain settings, the base currents of the output transistors Q2A, Q2B can result in a deviation from the gain predicted by Eq. 1. This is due to the fact that the base currents of the output transistors Q2A and Q2B are taken from the-input signal, which effectively lowers the actual signal current available at the collectors of the input transistors Q1A and Q1B. The total small-signal base current that is drained away from the input at each side of the circuit equals the sum of the base currents of the input transistors ("ib1") and the sum of the base output transistors ("ib2"). To first order, the sum of the base currents of the input transistors Q1A and Q1B is i.sub.in /.beta., while the sum for the output transistor Q2A and Q2B is A.sub.i i.sub.in /.beta.. Therefore, the total signal current directed away from the collectors of Q1A and Q1B is i.sub.in (1+A.sub.i)/.beta., and the total gain A.sub.i,.beta. becomes ##EQU2## By defining the desired gain setting A.sub.i,d ##EQU3## we can approximate Eq. 2 by ##EQU4## Assuming a current gain .beta. of 50 and a gain setting A.sub.i =A.sub.i,d of 10, the resulting gain A.sub.i,.beta. becomes 7.8, which amounts to a gain error of 22% between the actual gain and the desired gain setting A.sub.i,d.
It is an object of the invention to provide a gain control circuit with less error between the actual gain of the circuit and the ideal gain, as indicated by the ratio of the bias current of the output and input transistors.
It is another object of the invention to provide such a circuit while maintaining high supply voltage rejection.
It is yet another object of the invention to provide such a circuit suitable for low voltage operation.

Low voltage, beta immune variable gain amplifier with high supply voltage rejection

Philips Electronics North America Corporation


A process for fabricating an MOS device specifically a DRAM device, featuring passivation of defects in regions of a semiconductor substrate wherein defects left unpassivated can deleteriously influence data retention time, has been developed. A high density plasma dry etching procedure used to define the DRAM conductive gate electrode can create unwanted defects in a region near the surface of uncovered portions of the semiconductor substrate during the high density plasma procedure over etch cycle. Implantation of a group V element such as arsenic can be used to passivate the unwanted plasma etch defects, thus reducing the risk of defect related device leakage phenomena. However to insure the group V implanted species remain at or near the semiconductor surface for optimum defect passivation, the group V element implantation procedure is performed after all high temperature DRAM fabrication steps, such as selective oxidation for creation of oxide spacers on the sides of the conductive gate electrode, have been completed. A slow diffusing implanted arsenic ion is the optimum candidate for passivation while faster diffusing group V elements such as phosphorous are not as attractive for defect passivation.

(1) Field of the Invention
The present invention relates to methods of fabricating semiconductor devices, and more specifically to a method for passivating defects on a semiconductor substrate wherein the defects are a result of plasma etching procedures.
(2) Description of Prior Art
Dynamic Random Access Memory (DRAM) devices require specific elements to retain induced charge for significant periods of DRAM operation. The ability of the DRAM elements to retain charge, or data retention time, is strongly influenced by the perfection or defect density of the portion of semiconductor substrate used for DRAM stored charge elements. Unwanted defects in portions of the semiconductor substrate will result in charge leakage, low retention time, and thus poor device yield and performance. Unfortunately several semiconductor device fabrication procedures can create defects in semiconductor substrates thus challenging the ability to fabricate efficient DRAM devices. Plasma dry etching processes such as reactive ion etching (RIE), specifically high density plasma procedures performed to define many critical features in scaled down (smaller geometries) semiconductor devices, can result in damage in the form of defect generation at semiconductor substrate. These defects lead to unsaturated chemical bonds at the semiconductor surface promoting charge leakage from storage elements of a DRAM device. The data retention time loss or charge leakage mechanisms suffered by DRAM devices can be in the form of junction leakage and defect assisted gate induced drain leakage (GIDL).
The present invention will feature passivation of the surface defects caused by high density plasma etching procedures via introduction of a passivating dopant at the semiconductor surface performed after high temperature fabrication procedures have already been executed thus maintaining the passivating dopant at or near the surface of the semiconductor substrate. Numerous attempts at improving data retention time have focused on semiconductor substrate defect reduction, however most of these works involve major and costly process or design modification. Prior art such as Schmitt et al U.S. Pat. No. 4,332,627, as well as Colombo et al US Pat. No. US2004/0127000 A1, teach methods of eliminating process induced defects via use of high temperature anneals after arsenic processing, however these prior art result in arsenic being driven into the semiconductor substrate away from the top surface where plasma etch induced defects are formed. Other prior art such as Cote et al U.S. Pat. No. 6,483,172 B1, Yamaguchi et al U.S. Pat. No. 6,709,906 B2, Fowler U.S. Pat. No. 3,849,204, Solomon et al U.S. Pat. No. 6,803,266 B2, Derycke US Pat. No. US2004/0104406 A1, and Grasser et al U.S. Pat. No. 4,835,006, disclose various processes and procedures for reduction of semiconductor defects, however none of these features of the present invention in which surface defects are reduced via use of specific group V elements introduced at a point in the fabrication process wherein all high temperature procedures have already been performed.

Method for passivation of plasma etch defects in DRAM devices


A suture retaining device in the form of a frusto-conical button having parallel upper and lower planar surfaces which are connected together by a conical surface. The button is provided with a recessed chamber for substantially completely accommodating one or more suture knots. At least one hole is formed in the button leading from the recessed chamber to the lower planar surface, and at least one hole is formed in said button leading from the recessed chamber to the conical surface.

Many devices are currently available for use in effecting surgical attachments, particularly in attaching objects to bone.
In some procedures, for example, a hole is first drilled in a bone, and then a suture anchor is deployed in the hole, with a suture element trailing from the suture anchor and extending out of the bone. Tissue or other objects may then be secured to the bone using the suture. In some cases the suture may extend completely around the tissue or other object which is being attached to the bone; in other cases the suture may be passed through the tissue or other object and then tied off on the far side of the tissue or object so as to effect attachment. In the case where the suture extends through the tissue or other object and is tied off on the far side thereof, various types of washers or buttons have been proposed to facilitate attachment. These washers or buttons rest against the outer surface of the tissue or other object, and improve the connection between the suture and the tissue or object.
The need for such secure attachment is particularly critical in connection with reapproximating bone of any type to another bone. This type of procedure is exemplified in applications such as joining the fibula to the tibia bone in ankle surgery, or as applied to a shoulder operation. In the case of acromioclavicular and coracoclavicular suture fixations, for example, several holes are drilled in the clavicle above the coracoid. A suture is passed beneath the base of the coracoid and superiorly through the two holes in the clavicle. Another suture is attached to the acromioclavicular ligament and then attached to the clavicle. The joint is then reduced and the sutures are tied off. Sutures such as mattress sutures may be placed in any ruptured coracoclavicular ligaments and also tied off. In addition, the ligaments may be joined to the bone by the same technique.
This procedure is significantly improved by the use of suture anchors, which can be recessed into the coracoid and the suture extended superiorly through only a single hole in the clavicle. This eliminates the need to place a suture exteriorly of the coracoid and thereby removes the possibility of the suture subsequently eroding because of motion in the shoulder.
Even with this improved procedure, however, there still remains the necessity of tying off the suture. As indicated above, conventional surgical buttons, washers or other suture retaining devices may be used, where the suture is pulled through the retaining device and tension then applied to the tissue before the suture is tied off.
One such type of suture retaining device is shown in U.S. Pat. No. 4,741,330 issued May 3, 1988 to Hayhurst. As taught in this patent, the suture retaining device is a button of resilient material having slits formed therein which cross at the center of the button, in order to create pointed bendable flaps. The suture is inserted through the center of the button and the flaps are resiliently deformed away from the plane of the button, toward the direction of movement of the suture. Thereafter, the button is urged toward the surface of the tissue which is to be joined to a bone and, after tension is applied to the suture while pushing against the button, the suture is tied off so as to hold the tissue securely against the bone.
In another type of retaining device, as exemplified by U.S. Pat. No. 4,669,473 issued Jun. 2, 1987 to Richards et al., the suture (or filament) is provided with a plurality of conically shaped ribs along its length. The ribs are formed so that the larger end of each rib faces toward the tissue or bone. Such ribs allow an associated flexible washer to be slid over the suture (or filament) and over the ribs in the direction of the tissue or bone, yet prevent the washer from slipping backward over a conically shaped rib once it has passed that rib. In this manner the washer can be brought to bear against the tissue and held there by the nearest conical rib.
In all of the known prior art suture retaining devices, there remains the drawback that the buttons or washers, as well as the suture knots, are left protruding above the superior tissue or bone surface at the conclusion of the procedure. As a result, the buttons and/or knots may cause trauma to a patient when the joint or body part is thereafter subjected to movement.
It is, therefore, one object of the present invention to provide a suture retaining device which permits the suture knot to be recessed below the top surface of the tissue or bone element which is being approximated to another bone using suture.
Another object of the present invention is to provide a suture retaining device which is itself capable of being disposed below the superior surface of the tissue or bone element which is being approximated to another bone using suture.
Still another object of the present invention is to provide a suture retaining device for use with a suture anchor, wherein both the suture knot customarily employed in tying off the suture, as well as the retaining device itself, are both embedded below the tissue or bone surface.
A further object of the present invention is to provide a suture retaining device which permits ligaments to be transversely attached to a bone by means of a side hole or holes formed in the suture retaining device.
A still further object of the present invention is to provide a suture retaining device for use in fixedly holding ligament graft material within a bone tunnel.
And another object of the present invention is to provide a suture retaining device which may be used with at least one length of suture to approximate an object to an anatomical structure.


A light emitting diode (LED) dimming module includes an energy storage circuit, a load interface circuit, and a switch circuit. The energy storage circuit provides a substantially continuous current in response to a converter current. The load interface circuit provides a modulated load current in response to the continuous current. The switch circuit, which is operatively coupled to the load interface circuit, switches in accordance with a duty cycle. The modulated load current is based on the duty cycle.

Light emitting diode (LED) lighting technology is becoming more widely used due to having a longer lifespan, fewer hazards, and increased visual appeal compared to compact fluorescent lamp (CFL) or other types of lamps. Wide applications of LEDs for lighting, televisions, monitoring panels and/or other applications increasingly requires dimming.
There are different categories of dimming for lighting applications. In one type of dimming for lighting applications, a TRIAC dimmer circuit removes a portion of the ac input voltage to limit the amount of voltage and current supplied to lamp. This is known as phase dimming because it is often convenient to designate the position of the missing voltage in terms of a fraction of the period of the ac input voltage measured in degrees. In general, the ac input voltage is a sinusoidal waveform and the period of the ac input voltage is referred to as a full line cycle. As such, half the period of the ac input voltage is referred to as a half line cycle. An entire period has 360 degrees, and a half line cycle has 180 degrees. Typically, the phase angle is a measure of how many degrees (from a reference of zero degrees) of each half line cycle the dimmer circuit removes. As such, removal of half the ac input voltage in a half line cycle by the TRIAC dimmer circuit corresponds to a phase angle of 90 degrees. In another example, removal of a quarter of the ac input voltage in a half line cycle may correspond to a phase angle of 45 degrees.
Although phase angle dimming works well with incandescent lamps that receive the altered ac line voltage directly, it typically creates problems for LED lamps driven by a switching power converter. Conventional regulated switching power converters are typically designed to ignore distortions of the ac input voltage and deliver a constant regulated output until a low input voltage causes them to shut off. As such, conventional regulated switching power converters cannot dim LED lamps. Unless a power converter for an LED lamp is specially designed to recognize and respond to the voltage from a TRIAC dimmer circuit in a desirable way, a TRIAC dimmer can produce unacceptable results such as flickering of the LED lamp.
Another difficulty in using TRIAC dimming circuits with LED lamps comes from a characteristic of the TRIAC itself. A TRIAC is a semiconductor component that behaves as a controlled ac switch. In other words, it behaves as an open switch to an ac voltage until it receives a trigger signal at a control terminal, which causes the switch to close. The switch remains closed as long as the current through the switch is above a value referred to as the holding current. Most incandescent lamps use more than enough current from the ac power source to allow reliable and consistent operation of a TRIAC. However, the low current used by efficient power converters to drive LED lamps may not provide enough current to keep a TRIAC conducting for the expected portion of the ac line period. Therefore, conventional power converter controller designs rely on a dummy load, sometimes called a bleeder circuit, to take enough extra current from the input of the power converter to keep the TRIAC conducting.
In addition, the sharply increasing input voltage when the TRIAC fires during each half line cycle causes inrush input current ringing which may reverse several times during the half line cycle. During these current reversals, the TRIAC may prematurely turn off and cause flickering in the LED lamp. A series resistor damper may then be utilized to slow down the charging of the input capacitor, and dampen the input current ringing and prevent voltage overshoot of the input capacitor. In general, the damper circuit is external from the integrated circuit of the power converter controller and is implemented with a resistor coupled at the input of the power converter. However, use of the damper resistor and the dummy load degrades the overall efficiency of the system.
Some LED drivers use analog dimming to adjust LED brightness levels. Analog dimming adjusts brightness by changing forward current of the LEDs. For example, if an LED is at full brightness with 20 mA of forward current, then 25% brightness can be achieved by driving the LED with 5 mA of forward current. While this dimming scheme works well for lower end displays, the color of the LEDs shifts with changes in forward current, which is undesirable.
Other LED drivers use digital dimming such a pulse width modulation (PWM) to periodically switch between a determined current (e.g., logical high) and a substantially zero current (e.g., logical low) flow through the LED. This technique can adjust LED brightness while maintaining color quality. However, this technique requires a high frequency to prevent flickering that may be detectable by human eyes and/or cause digital noise, which is undesirable.
As such, a method and apparatus is desirable to overcome one or more of the aforementioned disadvantages.

LED dimming circuit for switched dimming


A electronic package is constituted of a compliant multi-layered circuit board or printed circuit board package, particularly for use in ball grid array (BGA) applications wherein two or possibly greater numbers of naturally spaced sub-composites are equipped with electronic circuitry which is interconnected through the intermediary of conductive adhesives. Pursuant to a method of producing, no other mechanical connection is provided intermediate these spaced sub-composites except, possibly, along the periphery of the structure thereof, where a molded plastic seal may be provided in order to form a protection against the ingress environmental or external influences. The unfilled void, space or interspatial volume which is present between the spaced sub-composite facilitates the deformation in shear of the conductive adhesive interconnections, such as epoxy resins or the like, with extremely little constraint of the various components.

1. Field of the Invention
The present invention relates to electronic packages consisting of compliant multi-layered circuit boards or printed circuit cards for plastic ball grid array (PBGA) applications, and in particular, may relate to different types of ball grid array packages which are designed to reduce the effects of differential thermal expansions to which PBGA packages are subjected. Moreover, the invention is also adapted to provide a method of manufacturing such types of compliant multi-layered circuit boards or printed circuit cards of this type.
In the technology, electronic packages, such as PBGA packages or TBGA (tape ball grid array) packages are presently utilized in order to form reliable interconnections between semiconductor chips which are supported on printed circuit cards or boards. Generally, the flexibility of the tape of the tape ball grid array renders it possible to accommodate large differences in thermal strains which are encountered between a semiconductor chip ordinarily possessing a coefficient of thermal expansion (CTE) of approximately 3 ppm/xc2x0C., and a printed circuit card, normally possessing a typical CTE of approximately 17 ppm/xc2x0C. Nevertheless, this accommodation is only possible with a depopulated ball grid array (BGA), inasmuch as provision must be made for a free or open area between the edge of the semiconductor chip and the innermost row of balls, which can be easily deformed in order to be able to absorb the thermally-induced strain. As a result, the number of inputs and outputs (I/O""s) which can be provided in such an electronic package are essentially limited in quantity.
Basically, PBGA electronic packages each possess multiple dielectric layers and are relatively thick and rigid in their overall and assembled construction. Consequently, any bending of the package which is encountered due to the rigid nature of the coupling or interconnections between the essentially laminated substrate or circuitized carrier and semiconductor chip results in a premature failure of the BGA interconnections. Moreover, the constraint of the carrier or substrate by the semiconductor chip also reduces its effective coefficient of thermal expansion (CTE), thereby resulting in the formation of a shear strain in the BGA and consequent early fatigue of the electronic package, leading up to its failure. Additionally, the differential expansion between the semiconductor chip and the circuitized carrier or substrate can also produce fatigue of any C4 interconnections (control collapse chip interconnections) which are present in flip-chip applications.
In view of the above-mentioned problems, PBGA packages have been proposed in the technology, which incorporate dielectric layers possessing a very low shear stiffness, and wherein examples of the materials which may be employed included such as PTFE (polytetrafluoroethylene) and silicone. However, both of these dielectric materials present technological processing challenges; and moreover, silicone is subject to a very high out-of-plane degree of expansion, which due to its high bulk modulus and the degree of constraint of the components, can also lead to premature failure of plated through-holes (PTH""s) which are formed in the electronic package.
Heretofore, compliant layers have been proposed as a solution which is intended to reduce the effects of differential thermal expansion on C4 connect and BGA service life expectancy in PBGA electronic packages. Consequently, the intent has been to attain a reduction in the stiffness of a layer by reducing its modulus or, alternatively by using a material which deforms plastically under a low stress. PTH""s and vias which have been formed in the electronic packages reduce this compliance to some degree and accordingly may also be subject to an early fatigue failure. The moduli and yield strengths of these materials are relatively low when compared with glass-epoxy prepreg or other materials which are employed for dielectric layers; for example, 70 MPa vs. 5 GPa.
Moreover, conductive epoxies have also been used for the purpose of connecting sub-composites or layers of a multi-layer electronic package; however, voids or open volumes or spaces have not been intentionally formed in the resultant assembly. A second, nonconductive adhesive has normally been employed as an insulator between the layers of the sub-composites, and wherein a continuous layer of material between the sub-composites is considered to be desirable in the technology inasmuch as a lamination process is carried out under a relatively high pressure.
Thus, in essence, the technology has addressed itself with only limited success at this time in overcoming the disadvantages and shortcomings encountered in the constructions of electronic packages of this type.
2. Discussion of the Prior Art
Hansen, et al. U.S. Pat. No. 5,672,400 discloses an electronic assembly with semi-crystalline copolymer adhesive wherein layers of first and second substrates are interconnected electrically through a semi-crystalline copolymer adhesive composition, such as in the form of a film. The interconnecting film completely fills out the interspace between the two surfaces of the substrates layers carrying the electronic circuits and is deemed to be subject to the disadvantages described hereinabove with regard to early failure of the BGA electronic package due to encountered bending strains and stresses.
Gaynes, et al. U.S. Pat. No. 5,478,700 discloses a method of applying bonding agents to a pad and/or interconnection sites in the manufacture of electrical circuits using a bonding agent injection head. Although this particular structure is generally quite satisfactory in use, it does not specifically address itself to a construction and method of producing electronic packages constituted of compliant multi-layer circuit boards or printed cards for PBGA applications in the unique a manner as disclosed by the present invention.
Basavanhally, U.S. Pat. No. 5,221,417 discloses a conductive adhesive film manufacturing technique for multilayered electronic packages, wherein a film completely fills the interspace between first and second conductor arrays located on the facing surfaces of separate spaced substrate structures of the electronic package.
Nakamura, et al. U.S. Pat. No. 5,041,183 discloses a method for the preparation of a hot-melt adhesive interconnector utilized in electronic packages, wherein a type of film containing conductive adhesive spots is positioned intermediate separate substrate layers so as to completely fill the interspaces thereof.
Finally, Matsumoto, et al. U.S. Pat. No. 4,692,843 discloses a multi-layered printed wiring board wherein spaces are provided in order to separate discrete layers of a substrate. This type of circuit board structure is relatively complex, and moreover does not address itself to the problems solved by the present invention in the provision of a compliant multi-layered circuit board for PBGA utilization.
Accordingly, pursuant to the present invention, there is provided an electronic package constituted of a compliant multi-layered circuit board or printed circuit board package, particularly for use in ball grid array (BGA) applications wherein two or possibly greater numbers of naturally spaced sub-composites are equipped with electronic circuitry which is interconnected through the intermediary of conductive adhesives. No other mechanical connection is provided intermediate these spaced sub-composites except, possibly, along the periphery of the structure thereof, where a molded plastic seal may be provided in order to form a protection against the ingress environmental or external influences. Basically, an important aspect of the present invention resides in that the unfilled void, space or interspatial volume which is present between the spaced sub-composite facilitates the deformation in shear of the conductive adhesive interconnections, such as epoxy resins or the like, with extremely little constraint of the various components.
Through the presence of unfilled spaces being provide between or among the spaced, layers of the sub-composites of the electronic package, the shear stiffness which is encountered can be materially reduced. For example, 200 micron diameter epoxy interconnections at a pitch of 350 microns spaced between the layers of the sub-composites would reduce shear stiffness by approximately 75%, as elucidated in further detail hereinbelow.
Accordingly, it is a primary object of the invention to provide a compliant multi-layered circuit board or printed circuit card which incorporates at least two spaced sub-composites or circuitized substrates incorporating unfilled interspaces therebetween so as to enable shear deformation of the electrical interconnections thereof under only very limited conditions of constraint.
Another object of the present invention is to provide a compliant multi-layer electronic package of the type described with interconnections adapted for PBGA applications, to which there is imparted an enhanced flexibility through the intermediary of spaced sub-composites of the electronic package providing for unfilled interspaces between the individual composite layers mounting the electronic circuitry.
Another object of the present invention is to provide a method of forming compliant multi-layered circuit boards or printed circuit cards of the type described herein, which enhances the service life of the electronic package by reducing the shear stiffness thereof through a novel multilayered spaced construction of increased flexibility.

Compliant multi-layered circuit board for PBGA applications

International Business Machines Corporation


A touch sensor integrated type display includes a display panel including a touch screen having touch sensors, a data driving circuit for driving data lines of the display panel, and a timing controller for generating a control signal for controlling a potential of an output terminal of the data driving circuit in vertical blank periods between adjacent vertical periods. The control signal selectively floats source output channels of the data driving circuit or selectively sets a potential of the source output channels to a predetermined voltage in the vertical blank periods.

A touch screen has replaced button switches as a user input device in order to provide light weight and a thin profile to household appliances and electronic devices. The touch screen is a device configured such that a user directly touches the screen without the use of other input devices and input information. Touch screens are now being used in the cellular phone market and have been widely used in most IT products.
The touch screen used in a display device includes a plurality of touch sensors and may be attached to a display panel of the display device. The touch screen may be classified into a resistive type touch screen, a capacitive type touch screen, an electromagnetic type touch screen, etc. based on its touch recognition manner. The capacitive type touch screen, which senses a position having changes in a capacitance and senses a touched portion, has been widely used.
As shown in FIGS. 1 and 2, a capacitive type touch screen includes a plurality of Tx electrode lines T1 to Tn, a plurality of Rx electrode lines R1 to Rm crossing the Tx electrode lines T1 to Tn, and a plurality of touch sensors formed at crossings of the Tx electrode lines T1 to Tn and the Rx electrode lines R1 to Rm, where m and n are a natural number. Each of the touch sensors is implemented as a mutual capacitor Cm. When a user touches the capacitive type touch screen with his or her finger, etc., an electric field between Tx and Rx electrodes of the mutual capacitor Cm is blocked. Hence, the amount of charge of the mutual capacitor Cm decreases. The touch sensors sense changes in the charge amount of the mutual capacitor Cm before and after a touch operation. For this, a charge voltage of the mutual capacitor Cm is readout to a readout integrated circuit (ROIC) through the Rx electrode lines R1 to Rm when a touch driving pulse is supplied to the Tx electrode lines T1 to Tn.
A display panel of a display device includes a plurality of data lines D1 to Dm to which a data voltage is applied. The Rx electrode lines R1 to Rm extend in the same direction as an extending direction of the data lines D1 to Dm and may partially overlap the data lines D1 to Dm. In this instance, the Rx electrode lines R1 to Rm and the data lines D1 to Dm, which partially overlap each other, are coupled to a parasitic capacitance Crx between the lines R1 to Rm and D1 to Dm.
Changes in a potential of the data lines D1 to Dm affect a potential of the Rx electrode lines R1 to Rm because of the parasitic capacitance Crx, thereby leading to a coupling noise. The coupling noise is mixed in a touch signal and thus greatly reduces a touch performance of the touch screen. As the coupling noise increases, a sensing value obtained by the touch screen may be excessively distorted. Hence, an undesired touch result may be obtained. Accordingly, a method for increasing a sampling rate (defined by the number of sampling operations per unit of time, for example, during one touch frame period) of sensing voltages readout by the touch sensors may be considered, so as to reduce the coupling noise. However, in this instance, the power consumption of the ROIC also increases.

Touch sensor integrated type display and method for driving the same