Magnetic domains in a thin magnetic film on information storage devices are aligned during manufacture of the device, preferably at the time the film is deposited onto a substrate by sputtering. A compact magnetic field generator generates a parallel magnetic field across the substrate with a magnet assembly that is not larger than approximately twice the size of the substrate or not larger than the sputtering target cathode assembly. The magnet assembly includes an interior magnet with poles at opposite ends of the substrate and two side magnets having pole pieces spaced by an air gap from the poles of the interior magnet. The interior magnet preferably includes a central magnet and two intermediate magnets, which share the same pole pieces as the central magnet. The interior magnets are located between the central magnet and the side magnets. The magnets, which are preferably electromagnets, are adjusted by varying the current therethrough, preferably by adjusting the current of the intermediate magnets, or by moving the pole pieces to adjust the gaps between those of the side and interior magnets, until the field is parallel to within one degree. Magnetic devices, such as read and write heads, are produced from products of the process.

The reading and writing of magnetic information and, more generally, the generation and sensing of discrete magnetic fields, is an art applicable to the recording and retrieving of digital information. In such applications, the increasing demands for higher information density on the recording media and for faster and more reliable transfer of information between read or write heads and magnetic storage media increase the need for devices that will provide high reading sensitivity, high information density, low noise and high speed switching. Such needs result in the imposition of requirements on the properties of magnetic materials used in the processes of information transfer between circuits and storage media. Generally, in such processes, it is better to use products that sense magnetic fields while interfering as little as possible with the magnetic field that is being sensed.
In magnetic read-write heads that are used in the recording and retrieval of digital information from magnetic discs or other such storage devices, the material used in the manufacture of the magnetic head provides a magnetically sensitive path through which magnetic flux must easily pass. Increased demands of industry for higher storage capacity and smaller devices, and thus higher storage information density and higher transfer rates, require better and more efficient magnetic materials for use in the reading and writing heads.
For example, with Giant Magneto-Resistive (GMR) devices such as those used as read heads for digital magnetic discs, sputter coated thin films of soft magnetic material are used for the sensing elements. In such elements, the size, shape, composition and magnetic orientation of the magnetic domains of this magnetic material affect the performance of the heads in facilitating high speed, high sensitivity switching through the creation and annihilation of domain walls. In such uses, alignment of the domains of the magnetic material with the magnetic fields being sensed increases the high speed, high sensitivity reading of information of the heads by, for example, reducing a phenomenon referred to as Barkhausen noise. One way to reduce this Barkhausen noise and to otherwise increase the sensitivity of the magnetic material film has been to provide a bias magnetic field to align the domains of the thin film of magnetic material on the head.
Demands for improved material films have resulted in demands to increase the degree of parallelism in the alignment of the magnetic domains, increasing the requirements for the parallelism of the fields used in aligning the domains to, for example, within one angular degree. In response to such demands, the domain alignment property has been typically controlled by placing a strong magnetic field in the vicinity of the manufactured substrate of which the devices are to be formed that have thereon the magnetic alloy layer, and then subjecting the substrate to post-processing in the form of heat treating or annealing in the presence of the magnetic field. Such treatment in the magnetic field causes the magnetic material domains to realign to achieve the desired magnetic orientation.
Magnetic structures used to generate the parallel magnetic fields for processing of the magnetic devices to align the domains generally produce a region in space at which the fields are sufficiently parallel. However, as distance increases from the center of the region, the magnetic field lines tend to diverge, resulting in insufficient parallelism of the field beyond a certain distance from the center. As a result, only a small substrate, or a small area on a substrate is exposed to a sufficiently parallel field to produce high quality devices. Such an area may be a two to four inch diameter area on a 6.times.6 inch wafer. Where, under present economic circumstances, the ultimate devices being manufactured from a single substrate may have a retail value of upward of one million U.S. dollars, and where, up to the time of the deposition of the magnetic film, the cost already incurred in processing the wafer may be several hundred thousand U.S. dollars, the ability to commercially use only a small wafer or small portion of a wafer, for example less than 30%, results in a substantial loss in potential product value. The size of the useful area of such a wafer can be increased by increasing the size of the portion of the field that is acceptably parallel. Increasing the size of the portion of the field that is acceptably parallel can be achieved by increasing the size of the biasing magnet structure. However, as the magnet is increased in size, the overall strength of the field diminishes since the saturation of the field in the magnet cannot be increased in proportion to magnet size.
Furthermore, providing the domain alignment in a post-processing step after the deposition of the magnetic film onto the substrate increases the cost of the devices and the time of the device production process. It accordingly would be desirable to subject the wafer to the bias magnetic field during the process by which the thin magnetic film is being deposited. However, in such deposition processes which are performed in vacuum processing machines which, for many reasons, are preferably limited in size, large magnets and magnetic field orienting devices are unacceptable and cannot be practically placed within or in operative relationship with the processing chambers of such machines.
Accordingly, there is an increasing need for a method and apparatus that will provide a sufficiently strong magnetic field having a high degree of parallelism, for example to within one angular degree, over a large substrate area, and that occupies a small space, preferably to fit within the confines of a thin film deposition apparatus.

Magnetic field generator, coating method and apparatus including same, and devices having coating aligned therewith


A method and a device for deploying a restraint system, which avoids false deployments at the least possible expense by using an acceleration sensor arrangement that includes two sensitivity axes oriented in different directions. An acceleration measured with respect to one of the two sensitivity axes is used for a plausibility check of a deployment decision, which is determined from an acceleration measured with respect to the other sensitivity axis. A trigger signal is only generated if a deployment decision signal and a plausibility signal are present at the inputs of an AND logic circuit at the same time.

The present invention relates to a method and device for deploying a restraint system in response to the impact of a motor vehicle against an obstacle. An acceleration sensor arrangement is included that has two sensitivity axes oriented in different directions, and an evaluation circuit generating a trigger signal for the restraint system from measured accelerations.
U.S. Pat. No. 5,202,831 describes that two acceleration sensors are provided for detecting front-end, rear-end, and lateral impacts. One of the two acceleration sensors has a sensitivity axis in the longitudinal direction of the motor vehicle and the other has a sensitivity axis in the transverse direction of the motor vehicle. Using a device of this type, it is possible to distinguish between a front-end or a rear-end impact and a lateral impact, so that the corresponding front-end or lateral airbags can be deployed.
One important goal in the design of restraint systems in a motor vehicle is to prevent a false deployment of airbags, i.e., depending on the direction of impact, only those airbags should be deployed that offer the vehicle passengers actual protection. To guard against a false deployment of restraint devices, it is conventional, as described in German Patent 195 14 082 to make the deployment depend not only on the response signal of an acceleration sensor, but rather to design the acceleration sensor arrangement in a redundant manner. Often, in addition to acceleration sensors, safety switches (safing or arming sensors) are used. As a result of the redundant design, the expense of the restraint system is increased in an undesirable manner.
An acceleration sensor system that is designed in a redundant manner is also known from European Patent 0 785 112 A1. In this context, two or three acceleration sensors are arranged in the rotor vehicle in different locations. The acceleration sensors are arranged so that their sensitivity axes are oriented parallel to each other. The sensitivity axes therefore all point in the same direction, so that all acceleration sensors react to an acceleration of the vehicle occuring in the direction of the common sensitivity axes. Finally, the reaction of one acceleration sensor is rendered plausible by the reaction of one or two other redundant acceleration sensors.
An acceleration sensor system that is designed in a redundant manner is described in European Patent No. 0785 112. In this sensor system, two or three acceleration sensors are arranged in the motor vehicle at different locations. The acceleration sensors are arranged such that their sensitivity axes are oriented parallel to each other. Therefore, the sensitivity axes all point in the same direction, so that all acceleration sensors react to an acceleration of the vehicle occurring in the direction of the common sensitivity axes. Finally, the reaction of one acceleration sensor is rendered plausible by the reaction of one or two other redundant acceleration sensors.
An object of the present invention is to provide a method and a device that provide high reliability with respect to false deployments of the restraint system at the least possible expense for the acceleration sensor arrangement.
The object is achieved by using an acceleration sensor arrangement that has two sensitivity axes oriented in different directions and by using the acceleration measured with respect to one of the two sensitivity axes in the plausibility check of a deployment decision. An evaluation circuit determines the deployment decision from the acceleration measured with respect to the other sensitivity axis. A trigger signal is only emitted when a deployment decision signal and a plausibility signal are present at the inputs of an AND logic circuit at the same time. The expense of the device according to the present invention is reduced in comparison to conventional devices because, using the acceleration sensors necessary for measuring the accelerations of the vehicle in the longitudinal and transverse directions, a reciprocal plausibility check is carried out, and therefore redundant acceleration sensors are not required.
Thus, given two acceleration sensor elements that have different sensitivity axes, a reciprocal plausibility check can be carried out.
It is possible to use three acceleration sensor elements, of which two have sensitivity axes oriented in the same direction and the third acceleration sensor element has a sensitivity axis oriented in a different direction. In this context, one of the two acceleration sensor elements that has sensitivity axes oriented in the same direction is brought to bear on the plausibility check of the third acceleration sensor element.
In order to be able to distinguish front-end or rear-end impacts and lateral impacts clearly from each other, it is advantageous that one sensitivity axis be oriented in the longitudinal direction and the other sensitivity axis be oriented in the transverse direction of the motor vehicle.
An acceleration sensor element arranged centrally in the motor vehicle that has a sensitivity axis in the transverse direction of the motor vehicle can be brought to bear, for the plausibility check, by one or a plurality of lateral impact sensors arranged on the periphery.
The plausibility check can be carried out as a threshold decision with respect to the amplitude, the gradient or the polarity of the measured acceleration or the integral of the measured acceleration.

Method and device for deploying a retaining system


A method of regulating the concentration of onium in a liquid onium poly(hydrogen fluoride) composition utilized in a hydrogen fluoride catalyzed alkylation reaction for a given level of total airborne hydrogen fluoride is disclosed. Also disclosed is a method of regulating the concentration of onium in the liquid onium poly(hydrogen fluoride) composition for a given level of RON. In one embodiment, the liquid onium poly(hydrogen fluoride composition is a mixture including pyridine and anhydrous hydrogen fluoride so as to give a pyridine poly(hydrogen fluoride) composition that is useful as a catalyst in the hydrogen fluoride catalyzed alkylation reaction.

1. Field of the Invention
The present invention is generally directed to a method of regulating the liquid onium poly(hydrogen fluoride) composition utilized in a hydrogen fluoride catalyzed alkylation reaction.
2. Background
The catalytic alkylation of an isoparaffin with an olefin to produce a branched paraffin is a commercially important process for producing high octane gasoline. In general, the process comprises the reaction of an isoparaffin such as isobutane with an olefin such as propylene, 1-butene, 2-butene or mixtures thereof in the presence of a liquid acid alkylation catalyst in a reaction zone. Reaction is followed by separation of the product and unreacted hydrocarbons from the liquid alkylation catalyst in a settling zone and purification of the alkylate product. If the isoparaffin is isobutane and the olefin is a butene, the alkylate product is isooctane. Alkylate product is used to enhance the octane number of automotive gasoline and aviation gasoline.
Strong mineral acids are particularly effective catalysts for this alkylation process. Anhydrous sulfuric and anhydrous hydrofluoric acid (hereafter, HF) are examples of two commonly used acid catalysts. Though effective, the volatility and destructive effect of super-heated, pressurized mineral acids on animal and human tissue are well known. In another study it was shown that a release of HF from an alkylation reactor would form a dense aerosol cloud that could travel several kilometers downwind and only slowly disperses.
One method of mitigating the potential danger of an accidental release of HF has been the development of containment systems that spray water or aqueous neutralizing agent upon the detection of a reactor leak. Such systems rely on detection technology and/or plant personnel to determine if a hazardous condition exists before activation of the spray system.
Another method of mitigating the potential danger of accidental release of HF is the proposed use of HF containing compositions in the HF alkylation reaction that lower the volatility of HF. One such method is disclosed in U.S. Pat. No. 5,073,674 to G. A. Olah in which liquid onium poly(hydrogen fluoride) complexes are suggested as being useful. One skilled in the art, however, should appreciate that actual practice of such a system will require a balance of chemical reactants, reaction conditions and environmental conditions in order to achieve a commercially viable sustained reaction process.

Method for optimizing hydrogen fluoride alxylation and increasing process safety


The present invention relates to compounds useful as inhibitors of voltage-gated sodium channels and calcium channels. The invention also provides pharmaceutically acceptable compositions comprising the compounds of the invention and methods of using the compositions in the treatment of various disorders.

Na channels are central to the generation of action potentials in all excitable cells such as neurons and myocytes. They play key roles in excitable tissue including brain, smooth muscles of the gastrointestinal tract, skeletal muscle, the peripheral nervous system, spinal cord and airway. As such they play key roles in a variety of disease states such as epilepsy (See, Moulard, B. and D. Bertrand (2002) "Epilepsy and sodium channel blockers" Expert Opin. Ther. Patents 12(1): 85-91)), pain (See, Waxman, S. G., S. Dib-Hajj, et al. (1999) "Sodium channels and pain" Proc Natl Acad Sci USA 96(14): 7635-9 and Waxman, S. G., T. R. Cummins, et al. (2000) "Voltage-gated sodium channels and the molecular pathogenesis of pain: a review" J Rehabil Res Dev 37(5): 517-28), myotonia (See, Meola, G. and V. Sansone (2000) "Therapy in myotonic disorders and in muscle channelopathies" Neurol Sci 21(5): S953-61 and Mankodi, A. and C. A. Thornton (2002) "Myotonic syndromes" Curr Opin Neurol 15(5): 545-52), ataxia (See, Meisler, M. H., J. A. Kearney, et al. (2002) "Mutations of voltage-gated sodium channels in movement disorders and epilepsy" Novartis Found Symp 241: 72-81), multiple sclerosis (See, Black, J. A., S. Dib-Hajj, et al. (2000) "Sensory neuron-specific sodium channel SNS is abnormally expressed in the brains of mice with experimental allergic encephalomyelitis and humans with multiple sclerosis" Proc Natl Acad Sci USA 97(21): 11598-602, and Renganathan, M., M. Gelderblom, et al. (2003) "Expression of Na(v)1.8 sodium channels perturbs the firing patterns of cerebellar purkinje cells" Brain Res 959(2): 235-42), irritable bowel (See, Su, X., R. E. Wachtel, et al. (1999) "Capsaicin sensitivity and voltage-gated sodium currents in colon sensory neurons from rat dorsal root ganglia" Am J Physiol 277(6 Pt 1): G1180-8, and Laird, J. M., V. Souslova, et al. (2002) "Deficits in visceral pain and referred hyperalgesia in Nav1.8 (SNS/PN3)-null mice" J Neurosci 22(19): 8352-6), urinary incontinence and visceral pain (See, Yoshimura, N., S. Seki, et al. (2001) "The involvement of the tetrodotoxin-resistant sodium channel Na(v)1.8 (PN3/SNS) in a rat model of visceral pain" J Neurosci 21(21): 8690-6), as well as an array of psychiatry dysfunctions such as anxiety and depression (See, Hurley, S. C. (2002) "Lamotrigine update and its use in mood disorders" Ann Pharmacother 36(5): 860-73).
Voltage gated Na channels comprise a gene family consisting of 9 different subtypes (NaV1.1-NaV1.9). As shown in Table 1, these subtypes show tissue specific localization and functional differences (See, Goldin, A. L. (2001) "Resurgence of sodium channel research" Annu Rev Physiol 63: 871-94). Three members of the gene family (NaV1.8, 1.9, 1.5) are resistant to block by the well-known Na channel blocker TTX, demonstrating subtype specificity within this gene family. Mutational analysis has identified glutamate 387 as a critical residue for TTX binding (See, Noda, M., H. Suzuki, et al. (1989) "A single point mutation confers tetrodotoxin and saxitoxin insensitivity on the sodium channel II" FEBS Lett 259(1): 213-6).
TABLE 1NaisoformTissueTTX IC50IndicationsNaV1.1CNS, PNS10 nMPain, Epilepsy,soma ofneurodegenerationneuronsNaV1.2CNS, high in10 nMNeurodegenerationaxonsEpilepsyNaV1.3CNS,15 nMPainembryonic,injured nervesNaV1.4Skeletal25 nMMyotoniamuscleNaV1.5Heart 2 μMArrythmia,long QTNaV1.6CNS 6 nMPain, movement disorderswidespread,most abuntantNaV1.7PNS, DRG,25 nMPain, NeuroendocrineterminalsdisordersneuroendocrineNaV1.8PNS, small>50 μM  Painneurons inDRG &  TGNaV1.9PNS, small 1 μMPainneurons inDRG &  TGAbbreviations:CNS = central nervous system,PNS = peripheral nervous sytem,DRG = dorsal root ganglion,TG = Trigeminal ganglion
In general, voltage-gated sodium channels (NaVs) are responsible for initiating the rapid upstroke of action potentials in excitable tissue in nervous system, which transmit the electrical signals that compose and encode normal and aberrant pain sensations. Antagonists of NaV channels can attenuate these pain signals and are useful for treating a variety of pain conditions, including but not limited to acute, chronic, inflammatory, and neuropathic pain. Known NaV antagonists, such as TTX, lidocaine (See, Mao, J. and L. L. Chen (2000) "Systemic lidocaine for neuropathic pain relief" Pain 87(1): 7-17.) bupivacaine, phenyloin (See, Jensen, T. S. (2002) "Anticonvulsants in neuropathic pain: rationale and clinical evidence" Eur J Pain 6 (Suppl A): 61-8), lamotrigine (See, Rozen, T. D. (2001) "Antiepileptic drugs in the management of cluster headache and trigeminal neuralgia" Headache 41 Suppl 1: S25-32 and Jensen, T. S. (2002) "Anticonvulsants in neuropathic pain: rationale and clinical evidence" Eur J Pain 6 (Suppl A): 61-8.), and carbamazepine (See, Backonja, M. M. (2002) "Use of anticonvulsants for treatment of neuropathic pain" Neurology 59(5 Suppl 2): S14-7), have been shown to be useful attenuating pain in humans and animal models.
Hyperalgesia (extreme sensitivity to something painful) that develops in the presence of tissue injury or inflammation reflects, at least in part, an increase in the excitability of high-threshold primary afferent neurons innervating the site of injury. Voltage sensitive sodium channels activation is critical for the generation and propagation of neuronal action potentials. There is a growing body of evidence indicating that modulation of NaV currents is an endogenous mechanism used to control neuronal excitability (See, Goldin, A. L. (2001) "Resurgence of sodium channel research" Annu Rev Physiol 63: 871-94.). Several kinetically and pharmacologically distinct voltage-gated sodium channels are found in dorsal root ganglion (DRG) neurons. The TTX-resistant current is insensitive to micromolar concentrations of tetrodotoxin, and displays slow activation and inactivation kinetics and a more depolarized activation threshold when compared to other voltage-gated sodium channels. TTX-resistant sodium currents are primarily restricted to a subpopulation of sensory neurons likely to be involved in nociception. Specifically, TTX-resistant sodium currents are expressed almost exclusively in neurons that have a small cell-body diameter; and give rise to small-diameter slow-conducting axons and that are responsive to capsaicin. A large body of experimental evidence demonstrates that TTX-resistant sodium channels are expressed on C-fibers and are important in the transmission of nociceptive information to the spinal cord.
Intrathecal administration of antisense oligo-deoxynucleotides targeting a unique region of the TTX-resistant sodium channel (NaV1.8) resulted in a significant reduction in PGE2-induced hyperalgesia (See, Khasar, S. G., M. S. Gold, et al. (1998) "A tetrodotoxin-resistant sodium current mediates inflammatory pain in the rat" Neurosci Lett 256(1): 17-20). More recently, a knockout mouse line was generated by Wood and colleagues, which lacks functional NaV1.8. The mutation has an analgesic effect in tests assessing the animal's response to the inflammatory agent carrageenan (See, Akopian, A. N., V. Souslova, et al. (1999) "The tetrodotoxin-resistant sodium channel SNS has a specialized function in pain pathways" Nat Neurosci 2(6): 541-8.). In addition, deficit in both mechano- and thermoreception were observed in these animals. The analgesia shown by the Nav1.8 knockout mutants is consistent with observations about the role of TTX-resistant currents in nociception.
Immunohistochemical, in-situ hybridization and in-vitro electrophysiology experiments have all shown that the sodium channel NaV1.8 is selectively localized to the small sensory neurons of the dorsal root ganglion and trigeminal ganglion (See, Akopian, A. N., L. Sivilotti, et al. (1996) "A tetrodotoxin-resistant voltage-gated sodium channel expressed by sensory neurons" Nature 379(6562): 257-62.). The primary role of these neurons is the detection and transmission of nociceptive stimuli. Antisense and immunohistochemical evidence also supports a role for NaV1.8 in neuropathic pain (See, Lai, J., M. S. Gold, et al. (2002) "Inhibition of neuropathic pain by decreased expression of the tetrodotoxin-resistant sodium channel, NaV1.8" Pain 95(1-2): 143-52, and Lai, J., J. C. Hunter, et al. (2000) "Blockade of neuropathic pain by antisense targeting of tetrodotoxin-resistant sodium channels in sensory neurons" Methods Enzymol 314: 201-13.). NaV1.8 protein is upregulated along uninjured C-fibers adjacent to the nerve injury. Antisense treatment prevents the redistribution of NaV1.8 along the nerve and reverses neuropathic pain. Taken together the gene-knockout and antisense data support a role for NaV1.8 in the detection and transmission of inflammatory and neuropathic pain.
In neuropathic pain states there is a remodeling of Na channel distribution and subtype. In the injured nerve, expression of NaV1.8 and NaV1.9 are greatly reduced whereas expression of the TTX sensitive subunit NaV1.3 is 5-10 fold upregulated (See, Dib-Hajj, S. D., J. Fjell, et al. (1999) "Plasticity of sodium channel expression in DRG neurons in the chronic constriction injury model of neuropathic pain." Pain 83(3): 591-600.) The timecourse of the increase in NaV1.3 parallels the appearance of allodynia in animal models subsequent to nerve injury. The biophysics of the NaV1.3 channel is distinctive in that it shows very fast repriming after inactivation following an action potential. This allows for sustained rates of high firing as is often seen in the injured nerve (See, Cummins, T. R., F. Aglieco, et al. (2001) "Nav1.3 sodium channels: rapid repriming and slow closed-state inactivation display quantitative differences after expression in a mammalian cell line and in spinal sensory neurons" J Neurosci 21(16): 5952-61.). NaV1.3 is expressed in the central and peripheral systems of man. NaV1.9 is similar to NaV1.8 as it is selectively localized to small sensory neurons of the dorsal root ganglion and trigeminal ganglion (See, Fang, X., L. Djouhri, et al. (2002). "The presence and role of the tetrodotoxin-resistant sodium channel Na(v)1.9 (NaN) in nociceptive primary afferent neurons." J Neurosci 22(17): 7425-33.). It has a slow rate of inactivation and left-shifted voltage dependence for activation (See, Dib-Hajj, S., J. A. Black, et al. (2002) "NaN/Nav1.9: a sodium channel with unique properties" Trends Neurosci 25(5): 253-9.). These two biophysical properties allow NaV1.9 to play a role in establishing the resting membrane potential of nociceptive neurons. The resting membrane potential of NaV1.9 expressing cells is in the −55 to −50 mV range compared to −65 mV for most other peripheral and central neurons. This persistent depolarization is in large part due to the sustained low-level activation of NaV1.9 channels. This depolarization allows the neurons to more easily reach the threshold for firing action potentials in response to nociceptive stimuli. Compounds that block the NaV1.9 channel may play an important role in establishing the set point for detection of painful stimuli. In chronic pain states, nerve and nerve ending can become swollen and hypersensitive exhibiting high frequency action potential firing with mild or even no stimulation. These pathologic nerve swellings are termed neuromas and the primary Na channels expressed in them are NaV1.8 and NaV1.7 (See, Kretschmer, T., L. T. Happel, et al. (2002) "Accumulation of PN1 and PN3 sodium channels in painful human neuroma—evidence from immunocytochemistry" Acta Neurochir (Wien) 144(8): 803-10; discussion 810.). NaV1.6 and NaV1.7 are also expressed in dorsal root ganglion neurons and contribute to the small TTX sensitive component seen in these cells. NaV1.7 in particular my therefore be a potential pain target in addition to it's role in neuroendocrine excitability (See, Klugbauer, N., L. Lacinova, et al. (1995) "Structure and functional expression of a new member of the tetrodotoxin-sensitive voltage-activated sodium channel family from human neuroendocrine cells" Embo J 14(6): 1084-90).
NaV1.1 (See, Sugawara, T., E. Mazaki-Miyazaki, et al. (2001) "Nav1.1 mutations cause febrile seizures associated with afebrile partial seizures." Neurology 57(4): 703-5.) and NaV1.2 (See, Sugawara, T., Y. Tsurubuchi, et al. (2001) "A missense mutation of the Na+ channel alpha II subunit gene Na(v)1.2 in a patient with febrile and afebrile seizures causes channel dysfunction" Proc Natl Acad Sci USA 98(11): 6384-9) have been linked to epilepsy conditions including febrile seizures. There are over 9 genetic mutations in NaV1.1 associated with febrile seizures (See, Meisler, M. H., J. A. Kearney, et al. (2002) "Mutations of voltage-gated sodium channels in movement disorders and epilepsy" Novartis Found Symp 241: 72-81)
Antagonists for NaV1.5 have been developed and used to treat cardiac arrhythmias. A gene defect in NaV1.5 that produces a larger noninactivating component to the current has been linked to long QT in man and the orally available local anesthetic mexilitine has been used to treat this condition (See, Wang, D. W., K. Yazawa, et al. (1997) "Pharmacological targeting of long QT mutant sodium channels." J Clin Invest 99(7): 1714-20).
Several Na channel blockers are currently used or being tested in the clinic to treat epilepsy (See, Moulard, B. and D. Bertrand (2002) "Epilepsy and sodium channel blockers" Expert Opin. Ther. Patents 12(1): 85-91.); acute (See, Wiffen, P., S. Collins, et al. (2000) "Anticonvulsant drugs for acute and chronic pain" Cochrane Database Syst Rev 3), chronic (See, Wiffen, P., S. Collins, et al. (2000) "Anticonvulsant drugs for acute and chronic pain" Cochrane Database Syst Rev 3, and Guay, D. R. (2001) "Adjunctive agents in the management of chronic pain" Pharmacotherapy 21(9): 1070-81), inflammatory (See, Gold, M. S. (1999) "Tetrodotoxin-resistant Na+ currents and inflammatory hyperalgesia." Proc Natl Acad Sci USA 96(14): 7645-9), and neuropathic pain (See, Strichartz, G. R., Z. Zhou, et al. (2002) "Therapeutic concentrations of local anaesthetics unveil the potential role of sodium channels in neuropathic pain" Novartis Found Symp 241: 189-201, and Sandner-Kiesling, A., G. Rumpold Seitlinger, et al. (2002) "Lamotrigine monotherapy for control of neuralgia after nerve section" Acta Anaesthesiol Scand 46(10): 1261-4); cardiac arrhythmias (See, An, R. H., R. Bangalore, et al. (1996) "Lidocaine block of LQT-3 mutant human Na+ channels" Circ Res 79(1): 103-8, and Wang, D. W., K. Yazawa, et al. (1997) "Pharmacological targeting of long QT mutant sodium channels" J Clin Invest 99(7): 1714-20); neuroprotection (See, Taylor, C. P. and L. S, Narasimhan (1997) "Sodium channels and therapy of central nervous system diseases" Adv Pharmacol 39: 47-98) and as anesthetics (See, Strichartz, G. R., Z. Zhou, et al. (2002) "Therapeutic concentrations of local anaesthetics unveil the potential role of sodium channels in neuropathic pain." Novartis Found Symp 241: 189-201)
Calcium channels are membrane-spanning, multi-subunit proteins that allow Ca entry from the external milieu and concurrent depolarization of the cell's membrane potential. Traditionally calcium channels have been classified based on their functional characteristics such as low voltage or high voltage activated and their kinetics (L, T, N, P, Q). The ability to clone and express the calcium channel subunits has lead to an increased understanding of the channel composition that produces these functional responses. There are three primary subunit types that make up calcium channels—α1, α2δ, and β. The α1 is the subunit containing the channel pore and voltage sensor, α2 is primarily extracellular and is disulfide linked to the transmembrane δ subunit, β is nonglycosylated subunit found bound to the cytoplasmic region of the α1 subunit of the Ca channel. Currently the various calcium channel subtypes are believed to made up of the following specific subunits:
L-type, comprising subunits α1Cα1Dα1F, or α1S, α2δ and β3a
N-Type, comprising subunits α1B, α2δ, β1b
P-Type, comprising subunits α1A, α2δ, β4a
Q-Type, comprising subunits α1A (splice variant) α2δ, β4a
R-Type, comprising subunits α1E, α2δ, β1b
T-Type, comprising subunits α1G, α1H, or α1I
Calcium channels play a central role in neurotransmitter release. Ca influx into the presynaptic terminal of a nerve process binds to and produces a cascade of protein-protein interactions (syntaxin 1A, SNAP-25 and synaptotagmin) that ultimately ends with the fusion of a synaptic vesical and release of the neurotransmitter packet. Blockade of the presynaptic calcium channels reduces the influx of Ca and produces a cubic X3 decrease in neurotransmitter release.
The N type Ca channel (CaV2.2) is highly expressed at the presynaptic nerve terminals of the dorsal root ganglion as it forms a synapse with the dorsal horn neurons in lamina I and II. These neurons in turn have large numbers of N type Ca channels at their presynaptic terminals as they synapse onto second and third order neurons. This pathway is very important in relaying pain information to the brain.
Pain can be roughly divided into three different types: acute, inflammatory, and neuropathic. Acute pain serves an important protective function in keeping the organism safe from stimuli that may produce tissue damage. Severe thermal, mechanical, or chemical inputs have the potential to cause severe damage to the organism if unheeded. Acute pain serves to quickly remove the individual from the damaging environment. Acute pain by its very nature generally is short lasting and intense. Inflammatory pain on the other had may last for much longer periods of time and it's intensity is more graded. Inflammation may occur for many reasons including tissue damage, autoimmune response, and pathogen invasion. Inflammatory pain is mediated by an "inflammatory soup" that consists of substance P, histamines, acid, prostaglandin, bradykinin, CGRP, cytokines, ATP, and neurotransmitter release. The third class of pain is neuropathic and involves nerve damage that results in reorganization of neuronal proteins and circuits yielding a pathologic "sensitized" state that can produce chronic pain lasting for years. This type of pain provides no adaptive benefit and is particularly difficult to treat with existing therapies.
Pain, particularly neuropathic and intractable pain is a large unmet medical need. Millions of individuals suffer from severe pain that is not well controlled by current therapeutics. The current drugs used to treat pain include NSAIDS, COX2 inhibitors, opioids, tricyclic antidepressants, and anticonvulsants. Neuropathic pain has been particularly difficult to treat as it does not respond well to opiods until high doses are reached. Gabapentin is currently the favored therapeutic for the treatment of neuropathic pain although it works in only 60% of patients where it shows modest efficacy. The drug is however very safe and side effects are generally tolerable although sedation is an issue at higher doses.
The N type Ca channel has been validated in man by intrathecal infusion of the toxin Ziconotide for the treatment of intractable pain, cancer pain, opioid resistant pain, and neuropathic and severe pain. The toxin has an 85% success rate for the treatment of pain in humans with a greater potency than morphine. An orally available N type Ca channel antagonist would garner a much larger share of the pain market. Ziconotide causes mast cell degranulation and produces dose-dependent central side effects. These include dizziness, nystagmus, agitation, and dysmetria. There is also orthostatic hypotension in some patients at high doses. The primary risk for this target involves the CNS side effects seen with Ziconotide at high dosing. These include dizziness, nystagmus, agitation, and dysmetria. There is also orthostatic hypotension in some patients at high doses. It is believed that this may be due to Ziconotide induced mast cell degranulation and/or its effects on the sympathetic ganglion that like the dorsal root ganglion also expresses the N type Ca channel. Use-dependent compounds that block preferentially in the higher frequency range >10 Hz should be helpful in minimizing these potential side-effect issues. The firing rate in man of the sympathetic efferents is in the 0.3 Hz range. CNS neurons can fire at high frequencies but generally only do so in short bursts of action potentials. Even with the selectivity imparted by use-dependence intrinsic selectivity against the L type calcium channel is still necessary as it is involved in cardiac and vascular smooth muscle contraction.
Unfortunately, as described above, the efficacy of currently used sodium channel blockers and calcium channel blockers for the disease states described above has been to a large extent limited by a number of side effects. These side effects include various CNS disturbances such as blurred vision, dizziness, nausea, and sedation as well more potentially life threatening cardiac arrhythmias and cardiac failure. Accordingly, there remains a need to develop additional Na channel and Ca channel antagonists, preferably those with higher potency and fewer side effects.

This patent is subject to a terminal disclaimer.

Quinazolines useful as modulators of ion channels


In a holographic surveillance system (10) for near real-time imaging of a target (15), a source of RF radiation directs a non-amplified reference beam of pulsed coherent RF electromagnetic radiation toward a target. An array of antennas (31) receives a reflected beam from the target together with a component of the reference beam so as to produce a signal representative of phase and amplitude data of received energy, and a processor (20) processes the signals so as to produce a holographic image for display on a display device coupled to the processor.

The need for a new and more versatile personnel inspection system in mass transportation centers has increased in recent years. Traditional inspection systems such as metal detectors and X-ray imaging systems, although capable of near real-time detection, have limitations and adverse effects in the detection of concealed targets. Limitations of metal detectors include the inabilities to (a) provide precise target location, (b) detect plastic concealed weapons, and (c) detect certain metals because of sensitivity variation for various metals. Limitations of X-ray imaging of personnel include radiological health effects. Consequently, holography has been under investigation as an alternative or complementary approach to personnel inspection.
Application of holography to the problem of personnel surveillance has been limited because of the inability to either (a) produce an image of sufficient resolution, or (b) produce an image in real-time, or (c) a combination of both. It is recognized that use of millimeter wave electromagnetic radiation is not a physiological health hazard and such radiation penetrates certain materials, including but not only clothing.
U.S. Pat. No. 5,455,590 (Collins et al.) published Oct. 3, 1995 entitled "Real-time holographic surveillance system" whose contents are incorporated herein by reference discloses a holographic apparatus for near real-time imaging of a target. The apparatus utilizes millimeter wave radiation having a frequency from about 1 to about 110 GHz and comprises:
(a) a holographic array having a plurality of low-gain, end-fire antenna units spaced apart from about 0.25 to about 1.5 wavelength, wherein each unit both sends and receives millimeter wave radiation. The units are connected by a plurality of electronic millimeter wave switches permitting sequential operation of the units, the array spaced apart from the target with a low f-number;
(b) a holographic transceiver system for operating the units and providing each unit with millimeter wave radiation source, then receiving high frequency millimeter wave radiation reflection from the target and collected by the unit, then making an analog oscillated reference signal, together with an analog reflected target signal;
(c) a real-to-imaginary converter for converting the analog oscillated reference signal and the analog reflected target signal to an analog real part of a hologram and an analog imaginary part of the hologram;
(d) an analog to digital converter for converting the analog real part and the analog imaginary part to corresponding digital parts; and
(e) a computer for applying a backward wave propagation algorithm that preserves the low f-number to the digital real and digital imaginary parts of the hologram to reconstruct a holographic image.
The apparatus disclosed by U.S. Pat. No. 5,455,590 requires a plurality of low-gain, edge-emitting antenna (known as end-fire) units. Furthermore, operational amplifiers are required to increase the gain of the RF in-phase "I" and quadrature "Q" signals, the gains of the operational amplifiers being set to match the maximum range of the analog to digital (A/D) converters. The antenna is scanned in an X-Y scanner to fill the aperture. Scanning may be mechanical or electrical. Electronic scanning is provided by transmitting and receiving a signal from an individual antenna unit in sequence one at a time in successive order. Electronic millimeter wave switches are used to direct signals to the antenna units.
It would therefore be desirable to provide an improved holographic surveillance system wherein at least some of the above-mentioned drawbacks are reduced or eliminated. Specifically, it would be an advantage to provide holographic surveillance system that permit direct detection with no need for RF amplification or mechanical scanning, thus achieving lower cost and faster imaging rate.

Video-rate holographic surveillance system


A method and processor for resolving a processing radar return data to determine a mechanical angle to a target relative to a radar array having a right antenna, an ambiguous antenna, and a left antenna. An LA linear relationship determining, based upon a characteristic number of LA wraps relative to the mechanical angle. Likewise, determining a RA linear relationship determines a characteristic number of RA wraps and a RL linear relationship determines a characteristic number of RL wraps relative to the mechanical angle. All permutations of LA wraps, RA wraps, and RL wraps are listed, and for each permutation, a truth relationship is determined. A look up table is populated with permutations where the truth relationship is true.

Pulse radar altimeters demonstrate superior altitude accuracy due to their inherent leading edge return signal tracking capability. The pulse radar altimeter transmits a pulse of radio frequency (RF) energy, and a return echo is received and tracked using a tracking system.
In a typical pulsed radio altimeter application, one to two radar strip antennas are mounted side by side on the underside of an aircraft, with their long axes oriented along the X-axis of the vehicle. In an unambiguous interferometric altimeter system a third antenna, referred to as the ambiguity antenna, is added. Referring to FIG. 1, an ambiguous antenna 6 serves as the transmitter, and all three antennas 4, 6, and 8 serve as receivers. The radar system tracks the closest ground returns by closing a control loop on the leading edge of a reflected radar pulse 13 received by the ambiguous antenna 6. The two outer antennas 4, 8 are used, in conjunction with the ambiguous antenna, to determine the cross-track angle of the first ground return. Cross-track angle θ is the angle between the vertical axis in the aircraft body frame and the object being detected also referred to as the mechanical angle.
The three radar antennas, 4, 6, 8, are arranged side-by-side, with the center 6 antenna closer to the left antenna 4 than to the right antenna 8. While in this non-limiting embodiment, the center antenna 6 is closer to the left antenna 4 rather than the right antenna 8, but, in fact, the only requirement is that the spacing between the antennas is not equal. These antennas 4, 6, 8 represent the baseline of a triangulation system that measures the electrical phase angle φ for the reflected radar pulse 13 from a target 11 between each pair of antennas: left antenna 4 to ambiguous antenna 6 (also referred to as "L-A"), left antenna 4 to right antenna 8 ("L-R"), and center antenna 6 to right antenna 8 ("A-R"). The relationship between the measured electrical phase angle φ and the cross-track (or 'mechanical') angle θ of the return, as measured from the antenna centerline, is determined by the wavelength of the radar signal and the separation of the two antennas in each pair. For any given return each pair of antennas will detect a different phase angle, due to the differing separations of the antennas.
Along with the three antennas, three processing channels, referred to below as left, right and ambiguous respectively, each include a receiver, a data acquisition device, range gate, and a filter. Use of the three antenna system, along with the processing described herein, provides a solution to the ambiguous detected angle of the nearest object. The ambiguous detected angle is due to the spacing of the antennas being greater than the transmitted RF frequency wavelength. By receiving three returns, the processing system using a phase comparison process is able to determine an unambiguous location of the nearest object on the ground.
During the phase comparison portion of the time interval, the Doppler filters of the left, right and ambiguous channels are set to select a swath (shown in the nonlimiting exemplar depicted in FIG. 1 as ranging from a −40 to +40 degrees relative to a vertical) below aircraft. A phase processor compares the phase difference between R1 and RA, R2 and RA, and R1 and R2 (as set forth in U.S. Pat. No. 6,856,279, incorporated by this reference) once the return signals are received. As illustrated in FIG. 1, the exact range differences ΦLA, ΦRA, and ΦLR are from phase differences and simple trigonometry relations are used to determine the exact crosstrack distance to the target 11 in aircraft body coordinates.
As illustrated in FIG. 1, after the range differences ΦLA, ΦRA, and ΦLR are determined and knowing the antenna separations SLA and SAR, and measured range R1, then the crosstrack distance (Y) and vertical distance (Z) can also be computed in aircraft body coordinates. It is important that the precise location of target 11 in each swath is determined so correlation can be made with the electronic maps which will accurately locate the aircraft on the electronic map. For example, at typical high speed aircraft cruising velocities, a radar, configured with reasonably sized Doppler filters, has swath widths of approximately 10 feet at 5000 feet altitude. The resulting incidence angle indicating the bearing of the target relative to a line normal to the surface of the center antenna 6 will then be on the order of less than 3 degrees. Basic trigonometry relations show that even with a typical error (for example 1%) on the radar range gate measured distance R1, (50 feet at 5000 feet altitude), knowing the precise antenna separation 50, and precise range differences ΦLA, ΦRA, and ΦLR, the crosstrack distance (Y) will be precise due to the very small incidence angle encountered.
Due to the geometry of the system it is possible for the electrical phase angle representing the phase difference between pairs of antennas to exceed 360 degrees, so that a radar return far from the antenna centerline may have the same electrical phase angle as a return that is nearer to the antenna centerline. This produces ambiguity when trying to determine mechanical angle when only electrical phase angle is known. For example, with a 1-foot separation between antennas L and R and a 4.3 GHz radar signal (wavelength=0.2291 feet), the electrical phase angle will increase from 0 to +180 degrees as the ground return moves from a mechanical angle of 0 degrees (straight below the aircraft) to an angle of 6.55 degrees. As the mechanical angle increases, the electrical phase angle will wrap back to 0 degrees at a mechanical angle of 13.1 degrees. Therefore, with a 2-antenna system it would be impossible to tell the difference between a ground return directly below the aircraft and a ground return 13.1 degrees to either side of the aircraft.
As the prior art process is currently executed, the solution of the probable location of the target requires a great deal of calculation. For each first spacing, for example ΦLA, the other two angles have to be checked requiring a calculation of ΦLR and ΦAR to check for convergence. As such, the calculation times are a function of the product of each of the possible solutions for each antenna separation. Processing time becomes extremely expensive, either in terms of performance or raw cost. The immense processing overhead the system portrayed in FIG. 1 generates is demonstrated by selection of real numbers.
In a non-limiting example depicted in FIG. 2, the L-A antenna separation is taken to be 4 inches, and the A-R antenna separation is taken to be 8 inches, then the L-R antenna separation is the sum of the distances, 12 inches. Assuming an exemplary RF frequency of 4.3 GHz, and an antenna beamwidth of 80 degrees, in order to unambiguously determine the mechanical angle of the ground return over the range −40 to +40 degrees, the 13 elements result in 75 possible combinations of electrical phase wraps, when we take one element from each of the 3 rows. The mechanical angle ranges over approximately 80 degrees. Because electrical angles are really phase measurements relative to the RF frequency, phase can wrap through a number of complete cycles such that triangulation may be based upon on angle θ′ which is equal to either the original θ or the original θ plus or minus a integral multiple of 360 degrees.
A well known relationship exists to generate the possible locations at which the electrical angle φ to the mechanical angle θ. FIG. 2 shows the generation of all possible combinations relating the mechanical angles θ to the electrical angles φ. (Numeric superscripts are used not to denote squares and cubes but rather variable names such that θ3 expresses the third possible value for θ and not the value θ raised to the third power). The combinatorial mathematics shows that seventy five possible combinations exist as to the combinations of mechanical and electrical angles resulting from the exemplary dimensions of the model shown in FIG. 1.
Processors according to the prior art perform a brute-force search of all 75 possible combinations in order to find the correct solution. First, the mechanical angle for all 13 elements of exemplary array of three antennas is computed. Then, each of the 75 possible combinations of antenna pairs (one element from each of the 3 rows in FIG. 2) is considered. The variance of the three selected mechanical angles is computed for each of the 75 combinations. The combination that has the lowest computed variance is taken to be the correct solution. Finally, the weighted average of the three computed mechanical angle values is computed. In this way the mechanical phase angle is determined from the electrical phase angles unambiguously.
What is needed in the art is a processor and a method for removing those of the solutions that are inherently nonconvergent so as to remove the inherent overhead of performing those calculations and checking their meaning against the situation in order to lighten the processing burden.

Method and processor for reduced ambiguity resolution matrix for interferometric angle determination


Systems and methods are provided for collaborative communication between a virtual healthcare assistant and a plurality of care providers. In one example, a system includes a display and a computing device operably coupled to the display and storing instructions executable to output, to the display, a public communication thread including communication among two or more care providers monitoring a patient and a virtual healthcare assistant, the public communication thread specific to the patient and responsive to a request from a first care provider of the two or more care providers, output, to the display, a private communication thread including communication only between the first care provider and the virtual healthcare assistant, the private communication thread specific to the patient.

Acute care of patients in a hospital or other medical facility may be carried out with multiple care providers per patient and may include multiple patient monitoring devices monitoring each patient. Thus, to ensure a rapid response should a patient's condition deteriorate, near-continuous monitoring of the output from the multiple monitoring devices may be necessary. Further, coordination of patient care among all the care providers may be complicated or time-consuming, further stretching care provider resources. Additionally, the presentation of patient medical information to the care providers may require multiple time-consuming and cumbersome requests or searches for information.

Systems and methods for public and private communication threads


Congestion caused by a large number of IGMP requests sent from set top boxes at channel switching is prevented in an optical line terminal (OLT). An IGMP processing section in the OLT has a delayed data generation threshold and a delayed data transmission threshold. When the number of ONTS participating in a multicast group is increased, the OLT generates a delayed multicast group for video data. The delayed multicast group having a few second delay accommodates a new user. With this, the end time of a highly popular program and a commercial start time are shifted among users to prevent, in the OLT, congestion caused by IGMP requests sent for channel switching at an identical time point.

1. Field of the Invention
The present invention relates to communication systems, optical line terminals (OLTs), and congestion control methods, and more particularly, to a communication system, an optical line terminal, and a congestion control method for preventing Internet group management protocol (IGMP) requests generated when video service viewing users switch the channels, from congesting in the optical line terminal in a passive optical network (PON).
2. Description of the Related Art
To transmit and receive large-size data and image signals through communication networks, the networks have been improved to have a higher rate and a wider band. PONs, which are defined by "Gigabit-capable passive optical network (GPON)", Recommendation G. 984, Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T), and other rules, have been introduced.
FIG. 1 shows the structure of a network in a PON system.
The network in the PON system includes, for example, a video service provider 17, an Internet service provider 18, a voice service provider 19, a router 16-1, an OLT 10, a core optical fiber 11, an optical splitter 12, a plurality of local optical fibers 13, optical network terminals (ONTs) 14-1 to 14-3, and terminals 15-1 to 15-3.
As shown in FIG. 1, for example, in the PON system, an upstream (service-provider-side) communication network is connected to the OLT 10 through the router 16-1; and the ONTs 14-1 to 14-3, which accommodate a plurality of subscriber terminals, are connected to the OLT 10 through a PON which includes the core optical fiber 11, the optical splitter 12, and the plurality of local optical fibers 13. The upstream network includes, for example, the video service provider 17, the Internet service provider 18, and the voice service provider 19. The ONTs 14-1 to 14-3 are respectively connected to the terminals 15-1 to 15-3 (such as set top boxes (STBs), telephones, and PCs).
Client data (such as video data sent by the video service provider 17, data sent by the Internet service provider 18, and voice calls and other service data for general subscribers sent by the voice service provider 19) is mainly transferred between the OLT 10 and the ONTs 14-1 to 14-3 (this part is also called a PON zone).
As broader bands have been used, IP multicast technologies, which distribute an identical content, such as video data, to a specified large number of users efficiently, have attracted attention. As such a technology, IGMP, recommended by the Internet Engineering Task Force (IETF), has been widely spread. In IGMP, a router that supports multicast (hereinafter also called a multicast router), such as the router 16-1, manages subscriber terminals, such as the ONTs 14-1 to 14-3, serving as members of each multicast group in a connection network and distributes identical data to a specified large number of subscriber terminals in each multicast group.
FIG. 2 is a sequence diagram for IGMP requests and video data stream in video multicast.
In multicast distribution using IGMP, an STB serving as a subscriber terminal uses IGMP to send a join request (IGMP join) 21 or a leave request (IGMP leave) 26 (these requests may be called just IGMP requests) for joining or leaving from a multicast group to a multicast router or to a video server; multicast group management apparatuses, such as an ONT, an OLT, and the multicast router, manage joins 22-1 to 22-3 to the multicast group and leaves 27-1 to 27-3 from the multicast group; and various types of multicast data is sent from a data distribution apparatus, such as a video server, only to the members (user terminals) participating in the multicast group with the members of the multicast group held at the multicast group management apparatuses being referenced.

Communication system, optical line terminal, and congestion control method


A semiconductor wafer according to the present embodiment includes a plurality of semiconductor chip regions and a division region. The plurality of semiconductor chip regions have a semiconductor element. The division region is provided between the semiconductor chip regions adjacent to each other. A first stacked body is provided on the division region. The first stacked body is configured with a plurality of first material films and a plurality of second material films alternately stacked.

A laser dicing technique is a method using a laser to modify the inside of a semiconductor wafer to cleave the semiconductor wafer from a modified portion as the starting point. However, since a cleavage that spreads from the modified portion has low straightness, a material film located on a dicing line of the semiconductor wafer is not divided in straight, so that a division line may meander. After the modification with the laser, when the semiconductor wafer is thinned in a polish process, the division line of the material film may further curve largely, so that a crack may reach a device region inside a semiconductor chip.

Semiconductor substrate and semiconductor device


An electronic apparatus has a display area of comparatively small surface area and is provided with a function selecting key unit for instructing execution of a plural number of data file preparing functions available on the electronic apparatus. A tablet is disposed on the display panel and the preset areas for display panel and tablet are provided as the display area. The tablet is provided with an input surface on which orthogonal coordinates are set in advance and outputs signals indicating the coordinate position instructed by a preset input pen. Image data including a group of coordinate points set on the input surface is prepared. When the input pen indicates pasting instruction, the data file specified by the pasting instruction is read out and displayed.

1. Field of the Invention
The present invention relates to a portable electronic apparatus having a function of preparing a plurality of data files and provided with means for inputting and displaying data.
2. Description of the Related Art
An electronic apparatus such as a personal computer, a word processor, etc. is provided with data file preparing means for preparing data files according to predetermined forms. For example, forms for preparing telephone directories, schedules, reports, handwritten memos, etc. are stored in the memory in advance and data files based on the respective forms are prepared. Moreover, with a view to improving conveniences of an electronic appapratus, the apparatus is provided with a so-called pasting function for inserting a data file prepared according to the form of a telephone directory in a data file prepared according to the form of a schedule, for example. The data file submitted to pasting is displayed, for example, on means for displaying provided on the electronic apparatus.
FIG. 35 is a plan view indicating an example of a display image 121 which appears when a data file submitted to pasting is displayed. It shows an example of a display image in the case where a data file named "Fax transmission" is prepared according to the form for preparing reports and a data file named "Guide map" prepared according to the form for preparing handwritten memos is pasted in that data file. The data file "FAX transmission" is composed of character data such as character codes, etc. while the data file "Guide map" is constituted by image data such as manually inputted map, etc. It is difficult to prepare such character data and image data with a single data file preparing means and, therefore, separate data files are prepared by using separate data file preparing means and then insertion of data is made with a pasting function as mentioned above.
On an electronic apparatus provided with a comparatively large screen such as a personal computer, a word processor, etc., a display image 121 in which the display image 123 of the data file "Guide map" is inserted in the display image 122 of the data file "FAX transmission" is displayed as shown in the drawing. The data file submitted to pasting is newly stored in the memory as a single data file.
Moreover, an electronic apparatus provided with a comparatively large screen such as a personal computer, a word processor and the like is provided with means for inputting data such as a keyboard, etc. and input is made from a plurality of keys provided on the keyboard. On the other hand, on a portable electronic apparatus such as a electronic pocket notebook, etc., inputting means such as a tablet, a touch panel, or the like are provided by accumulation on top of the displaying means instead of the keyboard to miniaturize the apparatus. A plurality of images (hereinafter referred to as "keys") corresponding to the kinds of processes performed by the apparatus are displayed on the displaying means, and the operator carries out inputting by touching the input surface of the inputting means corresponding to the keys with a given input pen. When the input surface of the inputting means corresponding to the displayed keys is touched by the input pen, the touched position is detected and the process corresponding to the displayed key including the touched position is executed.
Furthermore, some types of electronic apparatus using a tablet, a touch panel or the like, enable input of handwritten characters. Characters inputted in handwriting are once stored as image data, recognized as characters according to a prescribed procedure and then stored in memory as a code indicating recognized characters. An example of such electronic apparatus is disclosed, for example in Japanese Unexamined Patent Publication JPA 4-96886 (1992).
On an electronic apparatus provided with a comparatively small screen, it is difficult to make displays similar to those of a large electronic apparatus from the viewpoint of visibility, etc. and, for that reason, a display image displayed on a large electronic apparatus is split for showing. The same is true with the display of a data file submitted to pasting as mentioned above and the display image 121 as shown in FIG. 35 is displayed in a state of being split into several areas. For example, in the case where only the display image 122 of the data file "Guide map" is displayed here, a data file prepared by using another data file preparing means is displayed in spite of the fact that the data file preparing means for preparing reports is being executed. This spoils the consistency of display and produces an inconvenience that the operator just looks at the display image but cannot recognize the data file preparing means under execution, thus leading to a problem of poor operability of the electronic apparatus.
Moreover, on an electronic apparatus using tablet or touch panel, there are cases where the keys displayed on the displaying means are fixed and that the displayed keys are unnecessary depending on the content of execution of the electronic apparatus. If any unnecessary keys are displayed, the visibility drops because the display area available for the indication of data other than keys is reduced. In addition, it also causes a problem of reduced display area for each key, remarkably spoiling the operability of the electronic apparatus.
Furthermore, given as methods for recognizing characters are a method that characters are input one by one and the individual characters are recognized each time when they are input and a method that inputting all characters are input and then the characters in specified areas are recognized. With the former, in which individual characters are recognized each time when they are input, it is difficult to continuously input characters. Though continuous input of characters is possible if they are stored only as image data, complicated data processing becomes necessary for utilizing such image data with some other function. On the other hand, the latter enables continuous input of characters and Japanese Unexamined Patent Publication 4-96886 (1992) corresponds to the latter. The official gazette describes an example of recognition of characters made by specifying the area for each character after inputting all characters. In this example, there is an inconvenience that the area for recognition of characters must be specified for each character. It also produces another inconvenience that no recognition of characters can be made if the area specified for the input characters is improper.

Display of data files indicated by pasting instructing data indicating pasting of a data file in a displayed data file


A column and beam joint system is used to make possible the construction of a large tower such as an electrical transmission tower, which has at least three and probably four corner legs or columns which are interconnected and supported by a lattice structure of cross members. The columns have specialized channels extending substantially their full lengths and the cross members have specialized locking ends which lock into retaining structure defined in the channels, permitting braces to be inserted and locked in place at any selected point along the channel. A technique for connecting a cross member brace between a column and another cross member is also disclosed. All of the principle parts of the tower are pultruded composites which are either used in their longitudinally extended form or sectioned as required by the application. The entire tower can thus be formed of pultruded composites without the use of metal fasteners or connecting structure, enabling the tower to be made smaller and more compact, thus reducing induced EMF around the base of the tower.

The first patent application referenced above dealt with the use of pultruded composites generally with the construction of an electrical transmission tower. In the background of that disclosure is detailed the advantages of using pultruded composites as a replacement for steel in such a tower. These advantages result from physical, chemical, dielectric and electromagnetic properties of composite materials, which as used here refer to glass fibers woven into cloth which is drawn through a resin bath of polyester, vinylester, epoxy, or a thermoplastic such as polypropolene or polycarbonate, and then a die. A multiple-ply schedule is virtually always used.
The physical properties of composites that make it advantageous for use in electrical transmission towers are relatively high strength-to-weight ratio. However, it's low modulus of elasticity relative to steel requires that vertical support members and other structures be designed more creatively than is necessary with steel to mitigate the tendency of columns to buckle. Properly designed however, the tower structure is as strong or stronger than a tower of the same weight or cost made from steel.
Chemically, composites will resist corrosion and bacterial action indefinitely. They can be tailor-made to virtually any specifications depending on the application. Resistance to saltwater, ultraviolet light and virtually any destructive force can be designed into the composite.
The tower disclosed could be used for microwave, radio, or even windmill support, however, it is from the dielectric and electromagnetic perspectives that composites provide the greatest attraction in high voltage power line transmission towers. The high dielectric strength of glass composites and their low electrical conductivity make them much safer for repairmen, especially if the weather is inclement. When steel towers are maintained, there is a constant danger of flashover from a transmission wire to the steel tower structure. Wire grounding to the tower body may also be caused by a conductor being thrown across a tower structure in a storm. The steel construction aggravates many of the safety problems inherent in supporting high voltage power lines in the range of 115 kv. and higher.
An additional and unexpected advantage of composites over steel lies in the ability to bring the wires closer together due to the absence of the grounded conductive steel frame. Because the wires are out of phase with regard to the next closest wire or wires, the different phases will act to partially cancel out the electromagnetic field of adjacent wires and reduce the EMF at ground level. The closer the wires are together, the more cancellation of out-of-phase wires is exhibited.
By reducing EMF by bringing the conductors closer together, the tower can be made substantially smaller, with the highest conductors being substantially closer to the ground. This compaction reduces the widths of the right-of-way that must be purchased by the power authority to install the transmission towers. Currently, right-of-way purchase represents one of the major financial obstacles to electrical service expansion. This not only includes installation of new transmission lines but increasing the power capabilities of older lines. If a wider right-of-way must be purchased for a higher voltage transmission line due to ground level EMF regulations or just engineering standards, the cost may be prohibitive. However, using the tower described in this disclosure, of the same voltage class as the prior steel tower, a higher power transmission level can be achieved without expanding the right-of-way.
As discussed in one of the parent patents to this invention, the principal perennial problem with composites when used as structural members lies in the difficulty of forming joints. Steel is drilled, bolted and requires little imagination. Two steel beams or braces drilled and bolted together, or welded together, define a strong joint if done properly. The same techniques applied to composites will sever the continuous fibers which give the longitudinal fiber material its strength, and greatly weaken the structure at the joints. Therefore, steel is much simpler to use and currently structural engineers had steel construction emphasized in engineering school and in their professions and are generally entrenched in steel.
The need has thus presented itself to develop virtually innumerable new techniques for joining structural members of various sizes and configurations to withstand compression, sheer, and tension forces.
Although in the prototype stage substitution of composite structural members is more expensive than merely replicating steel configurations of the past, once the design has been perfected, pultrusion machines can run day and night with very little supervision, producing continuous elongated members having surprisingly complex cross-sections. Because the pultrusion process in its present state cannot create pultrusions of diverging or otherwise changing cross sectional configurations over the length of the piece, and thus cannot be strengthened at joint areas in the pultrusion process, connecting members together presents a challenge requiring considerable creativity.
The second-mentioned parent case to this invention tackled the problem of joining members of a large tower by the use of specially configured corner columns having slots which received specially designed cross members. That general concept is followed in this disclosure. The parent application used the low modulus of elasticity inherent in composite construction to create an internal slot or channel in the main support columns with deflecting detentes which received inserted ends of cross members having a mating detente configuration. When the cross members were inserted into the main slots of the columns, they locked in place. The column itself had internal partitions which yielded or expanded to admit the ends of the cross members.
In the instant disclosure, it has been determined that for the integrity and maximized strength of the columns, which will take the compressive loads of the tower, the columns should not define structural parts which yield to the insertion of cross members.

Bifurcated column joint system for electrical transmission tower


A cooling device controller for controlling a cooling device is provided. The cooling device controller includes: a capacitor for supplying an output voltage through a first terminal; a first switch between a first input terminal and the first terminal of the capacitor; a predetermined reference voltage applied to the first input terminal; a second switch between a second input terminal and the first terminal of the capacitor, wherein a temperature-sensing voltage is applied to the second input terminal, the temperature-sensing voltage varying according to a first sensed temperature; and a switch controller to receive a first voltage waveform having a duty ratio, the duty ratio dependent on a second sensed temperature, wherein the switch controller is operable to turn on and off the first switch and the second switch according to the duty ratio.

(a) Field of the Invention
The present invention relates to a pulse width modulation decoder and a cooling device controller.
In particular, the present invention relates to a circuit for controlling a cooling device with a predetermined temperature appropriate for a system.
(b) Description of the Related Art
As personal computer systems have developed to have higher clock rates, clock frequencies for the systems have also increased and the systems' heat generation has become an important issue. As the clock frequency becomes higher, ICs such as a CPU and a memory generate much heat and they may be abnormally operated or be burned without suitable cooling.
Many systems use a cooling fan, which cools the system by circulating the air. The fan sends the system'heated air outside and supplies cold air in its place.
However, the cooling fan generates noise because of the turbulent air flow and the friction of the bearings. If the cooling fan is operated at fixed revolutions per minute (rpm), then for extended intervals it provides more cooling than necessary, accompanied by excess noise. Hence, many systems control the operational rpm of the cooling fan according to the temperature. Some of these systems use thermistors to reduce costs.
A thermistor changes its electrical resistance according to temperature. Accordingly, thermistors are classified as NTC thermistors (Negative Temperature Coefficient Thermistors) whose electrical resistance decreases as the temperature increases, and PTC thermistors (Positive Temperature Coefficient Thermistors) whose electrical resistance increases as the temperature increases.
Even when the temperature is sensed by using a thermistor and the rpm of the cooling fan is controlled accordingly, it is not easy to appropriately control the rpm of the cooling fan because of the nonlinear dependence of the thermistor'resistance on the temperature and the nonlinearly of temperature sensing caused by the thermistor peripheral circuits. Most of the systems control the rpm of the cooling fan to be greater than necessary, thus consuming excessive power and generating excessive noise.

Apparatus for controlling cooling device and cooling system


A heddle shaft (1) has shaft rods (2, 3), which are embodied as profile bodies (12) having at least one hollow chamber (14). The shaft rods (2, 3) are joined together by lateral bracing posts (4, 5) and at least one center connector (11). For securing the latter, retaining pieces (23) are disposed in the hollow chambers and are accessible through windows (22). The retaining pieces (23) are preferably glued into the hollow chamber (14) and have one or more threaded bores for securing the center connector (11) by means of screws (37).

So-called heddle shafts are used for shedding in power looms. The heddle shafts are formed by a frame that is essentially rectangular in a front elevation view and whose upper and lower long, longitudinal edges are each formed by one shaft rod. Laterally, the shaft rods are joined by lateral bracing posts. The shaft rods are often formed by hollow chamber profiles. Heddle support rails that support the heddles are secured to the shaft rods. Each heddle has at least one yarn eyelet, through which a warp thread is guided. For shedding, the heddle shafts are moved up and down in rapid succession. For wide weaving widths, the result is very long shaft rods, which tend to sagging, as a function of the weaving speed (number of revolutions). To reduce such sagging and above all to avoid different sagging of different shaft rods, besides the lateral bracing posts, center connectors are occasionally used to join the shaft rods together. Such center connectors are struts that with their ends join the two shaft rods.
For instance, a heddle shaft with this kind of center connector is known from German Published, Examined Patent Disclosure DE-AS 26 20 778. The shaft rod comprises sheet-metal profiles, with a filler core between them, for instance of hard plastic foam, honeycomblike material, or a lightweight type of wood. The filler material is glued to the sheet-metal profiles. In order also to create a possible way of inserting the center connector, a free space between the sheet-metal profiles is filled with a rubber body, which is joined in firmly adhering fashion, for instance glued, to the flat sheet-metal profiles. An extension of a profile rail is retained in the rubber body, and with a widened head, this extension retains a so-called slide element that is also thrust into the interstice between the two sheet-metal profiles. Screws are inserted into this slide element and hold the center connector, here called an intermediate strut.
From Swiss Patent CH 547 366, a heddle shaft with an adjustable center connector is also known. Here the heddle shaft is formed by a hollow chamber profile, which in the region of the center connector may have a window oriented toward the respective other shaft rod. A retaining piece is disposed in the interior of the hollow chamber profile and is joined to the side walls of the hollow chamber profile.
This arrangement is not optimized for maximum weaving speeds.
From German Patent DE 32 20 710 C2, a heddle shaft is known with shaft rods which each, on their respective side toward the heddle support rail, have a narrow chamber for receiving a clamping piece. The chamber is accessible toward the heddle support rail through a window. A clamping piece inserted into the chamber acts here as an abutment for the center connector.
The transmission of force between the center connector and the shaft rod takes place in a relatively small space. Moreover, the embodiment of a longitudinally continuous chamber for the clamping piece requires increased consumption of material and thus results in a considerable mass for the shaft rod.
A shaft rod also embodied as a hollow profile is found in German Patent DBP 1083759. For attaching a plurality of center connectors, each shaft rod is provided, on its opening toward the heddle support rail, with an opening through which a suitable retaining piece disposed in the interior is accessible. The retaining piece has threaded bores for receiving screws, which retain the center connector.
With this as the point of departure, it is the object of the invention to create a heddle shaft which is especially suitable for high-speed power looms.


A method and system are disclosed for remotely storing information for initializing a configurable network device at a direct server in the network. The information for initializing the configurable network device is automatically retrieved and used by the network device to self-initialize after the network address of the directory server is provided. Included in the information in some embodiments are the network addresses of a policy server and an authentication server, thereby allowing the network device to automatically retrieve policy information and authentication information as needed. Remote storage of substantially all information used to setup and run the network device substantially reduces the effort needed to backup or change information for large distributed networks including numerous configurable network devices.

Distributed networks, including local area networks (LANs), wide area networks (WANs), metropolitan area networks (MANs), and the Internet, for example, are comprised of "nodes" interconnected by various transmission media. The term nodes refers broadly to a wide range of network devices such as: (a) computers and workstations; (b) switching devices, including bridges, multi-layer switches, and routers; and (c) special purpose devices including file servers and directory serves, for example. Many of these devices require numerous pieces of information in order to complete some form of set up procedure and make the device operational. This information, collectively referred to herein as device-specific setup (DSS) information or DSS data herein, required to make the device operational varies depending on the function of the device and its complexity.
The DSS information used by a switch generally includes information in traps, VLAN assignments, spanning tree information, routing tables, ATM circuit setup, and network management commands, for example. Being device-specific, the DSS generally differs from one device to the next. In a switch, for example, the DSS includes a listing of adjacent devices operatively coupled to the switch—including the make and model and port information—which is unique for each switch in the network. In modern switches, substantially all DSS data necessary to make a switch operational is retained at the switch in an information base in local memory. This DSS information is provided as input when the switch is installed and brought online.
In addition to the DSS information, a switch may also require various shared resources, including policy information and authentication information, for example. Policy information may include quality-of-service assignments, and authorization information generally includes account names, passwords, and access rights that restrict access to a network device such as a switch. The policy and authentication information is sometimes stored in one or more central databases referred to herein as shared resource servers. In particular, policy information is stored in a policy server while authorization information is stored at an authorization server. The shared resource servers generally maintain policy and authentication information for a multiplicity of devices.
There are four main problems with approaches presently known in the art. First, all the DSS information must be fed to each network device upon initialization of the device. This typically requires that the network administrator manually enter the information at the switch and or download the DSS information to the switch. This procedure must be repeated for each configurable device in the network, which is both labor intensive and susceptible to human error. Consider, for example a network including 100 switches which all use a common authentication server. After the authentication files are set up, each one of the 100 switches must be issued a set of commands instructing it to direct authentication information queries to the authentication server. While such commands are supported by various management protocols including the Simple Network Management Protocol (SNMP), the command that may differ from one switch to the next. As such, the network administrator may need to be familiar with the multiplicity of commands necessary to properly manage the devices.
The second problem is that modification of the network device configuration is extremely burdensome. To designate a new authentication server, for example, a set of commands informing each switch of the new authentication must be issued to each of the 100 switches. To compound the difficulty, one or more of those switches may be down or unreachable, making it necessary for the administrator to return to and update any previously-unavailable switch once it becomes reachable. Changing the policy server presents a similar level of difficulty.
Third, generating a backing up copy of DSS information for a large network is also overly burdensome. A back up copy of the DSS information must generally be acquired for every switch individually. There are presently no known procedures for simultaneously backing up substantially all the DSS information for a plurality of switches.
Fourth, designing and coding a network management system (NMS) to control or otherwise interface with a plurality of switches having different configuration requirements, different software installations, and different interfaces is unnecessarily difficult. To be useful, for example, a conventional NMS must be designed to support a large number of devices, whether or not those devices are in the client's subnet or are presently under the management of the NMS.
There is therefore a need for a system for conveniently storing, downloading, accessing, modifying, and backing up large quantities of DSS information for at least one managed network device.


A display substrate and a driving method thereof are provided. The display substrate includes a base substrate containing a monocrystalline silicon layer, a thickness of the monocrystalline silicon layer being less than that of the base substrate; an array circuit layer, disposed on the base substrate and including a plurality of transistors, each of which has an active layer inside the monocrystalline silicon layer; and a plurality of light-emitting elements, located at a side of the array circuit layer away from the base substrate. The array circuit layer includes a scan driving circuit, a data driving circuit and a plurality of pixel sub-circuits, and the plurality of pixel sub-circuits are connected to the plurality of light-emitting elements, respectively, to form a plurality of sub-pixels.

With an increasingly high need among customers for audio and video electronics products, the development of high-resolution and high-quality display devices has become a trend among manufacturers.
Due to its advantages such as self-illumination, high brightness, wide viewing angle, fast response time, and allowance to manufacture R, G and B full-color components, AMOLED has been regarded as one important next-generation display panel technology. In current markets, there have been audio panels and mobile phones employing small and medium size AMOLED as display panels, and it is expected that application of AMOLED can be expanded to other fields, especially the large-area display panels including mobile products, notebook computers, monitors, wall-hanging TV, etc.
The AMOLED technologies have transitioned from amorphous silicon thin film transistor (TFT) glass substrates to polycrystalline silicon thin film transistor glass substrates, and especially to low-temperature polycrystalline silicon thin film transistor glass substrates, currently the mainstream technology. The "low temperature" refers to a fabrication process temperature of below 600° C. During this process, excimer lasers are employed as a heat source; after passing through the projection system, laser beams with uniform energy distribution are produced, which project on the glass substrate with an amorphous-silicon structure. Atoms of the amorphous silicon thin film are rearranged upon absorption of the laser energy, so as to form a polysilicon structure with reduced defects, which has a high electron mobility of 50-300 cm2/v-sec.
As such, the thin film transistor components can be manufactured to be smaller, resulting in increased aperture ratio, improved light transmittance of the panel, and reduced power consumption. Therefor compared with the amorphous silicon technology, a low-temperature polycrystalline silicon thin film transistor display has a carrier mobility rate of more than a hundred times, has a lower power consumption, a higher brightness, and a higher resolution, and is also lighter, thinner, smaller, of higher quality, and easier to implement integration of the driving circuit module.
As for the integration of the driving circuit module as mentioned above, a scan (gate) drive circuit, or a scan (gate) driver, is integrated at a glass substrate along with a TFT array, through a process called GOA (Gate driver On Array) or GOP (Gate driver On Panel).
The GOA technology integrates scan drive circuit into an array substrate, to thereby remove the need for a dedicated scan drive integrated circuit. As such, GOA technology can potentially save materials, simplify manufacturing processes, and reduce manufacturing cost.

Display substrate and driving method thereof

ORDOS YUANSHENG OPTOELECTRONICS CO., LTD.


A device for measuring the displacement of a movable object includes a stationary light source that produces an incident light beam. A target feature, attached to, or integral with, the object, reflects the incident light beam and forms a first image of the light source in close proximity of the target feature. An imaging lens receives the reflected light beam and reforms the first image of the light source as a second image on the photodetector. The photodetector, spaced from the object, receives the reflected light beam and, in response thereto, produces an electric signal having a characteristic (such as amplitude) which is proportional to a received location on the photodetector of the second image and which represents a position of the object. The target feature includes a curved surface that reflects the light beam such that a small, point-like or line-like first image of the light source is formed and reformed as a second image on the photodetector. The displacement sensor device is particularly useful in a disk drive servo system application. The target feature is formed by ruling a groove within a surface of the object.

There is a great need in many applications to monitor the positions of a movable object relative to a desired position or positions. For example, it is desirable in disk drive servo systems to accurately detect the positions of a rotatable read/write head arm, relative to desired, known positions, so that the head arm can be moved into alignment with desired radial track locations on a disk to enable the read/write head to read from and write to such locations. Position sensing devices are devices aimed at providing such position detection. Displacement sensors are position sensing devices that monitor the positions of a movable object by repeatedly measuring the displacements of the object from a desired location.
Examples of conventional displacement sensors include capacitance gage devices, fiber-optic proximity sensors and optical sensors, such as interferometric sensors used commonly in disk drive servo systems. Many of the prior art displacement sensors either are incapable of achieving the degree of resolution (the smallest measurable displacement) required by certain applications (such as disk drive servo systems) or require expensive and/or complex circuitry and hardware to achieve such resolution. To achieve high resolution, certain displacement sensors require, for example, a precise and powerful laser light source or extremely close proximity between the sensing element and movable object, rendering such devices expensive and difficult to implement. Thus, a balance must be struck between device performance and simplicity.
U.S. Pat. No. 5,315,372 to Tsai describes a prior art disk drive servo system that employs an optical displacement sensor. The Tsai device includes a light source and a photodetector array attached, at spaced-apart locations, to a rotatable master arm, located externally of the disk drive. A reflector is attached to a rotatable read/write head arm at a location between the read/write head and the axis of rotation of the arm. During operation, the master arm first is aligned accurately with a desired radial track location on the disk using an interferometric device. Then, the displacement sensor operates to determine the position of the head arm relative to the master arm so that the head arm can be moved into alignment with the master arm.
The light source of the displacement sensor produces an incident light beam that is reflected by the reflector onto the photodetector array. The position on the photodetector array to which the light beam is reflected depends on the relative radial positions of the head and master arms. Each photodetector element of the array produces an electric signal having an amplitude proportional to the intensity of the received light. The signals produced by the array, thus, represent the relative radial positions of the head and master arms. Processing circuitry receives and decodes the signals output by the array to determine the relative head arm position and accordingly controls a motor to rotate the head arm until it is properly aligned.
The device disclosed in the Tsai patent suffers from a number of drawbacks. While the Tsai device is relatively structurally simple and fairly inexpensive to implement, it is burdensome to operate. The Tsai device requires a pre-knowledge of each master arm and relative head arm position in order to accurately interpret the electric signals produced by the photodetector array. Also, due to the significant spacing between the reflector and the read/write head on the head arm and, due also to the dual axes of rotation of the head arm and master arm, performance accuracy is sacrificed severely. Further, the displacement sensor of Tsai aims to monitor radial movements (those caused by rotations about the axis) of the head arm relative to the master arm. Because the reflector reflects the incident beam directly onto the photodetector, spaced significantly from the reflector, the sensor is sensitive not only to radial movements of the head arm but also to angular movements of the reflector. Thus, the precise angular orientation of the reflector on the head arm is crucial to precise operation. Any angular movements of the reflector with respect to the head arm may cause false measurements to occur.
A general object of the present invention to provide a method for forming a target feature employed within a simple, yet accurate, optical displacement sensor.

Displacement sensor and method for producing target feature thereof