The present invention relates to novel chimeric fibroblast growth factors (FGF) wherein the alanine at amino acid 3 and serine 5 of native human recombinant basic fibroblast growth factor are replaced with glutamic acid. The N-terminus sequence of the present chimeric FGFs identify homology with that of human acidic fibroblast growth factor. The mitogenic properties of the native human recombinant basic FGF are exhibited by the present chimeric FGFs, and they are efficiently expressed in E. coli at significantly greater yields that previously reported. Novel variants of this new glu.sup.3,5 basic fibroblast growth factor, such as those in which cysteine 78 and cysteine 96 are replaced, e.g., with serine or other amino acids, to produce stabilized versions of the glu.sup.3,5 basic FGF and eliminate disulfide scrambled forms, are also described.

The present invention relates to novel chimeric basic fibroblast growth factors and to the enhanced production of such factors (bFGF).
Polypeptide growth factors are hormone-like modulators of cell proliferation and differentiation. Growth factors are responsible for the regulation of a variety of physiological processes, including development, regeneration and wound repair.
In the course of study of these factors, a number have been identified on the basis of the ability of extracts from various tissues, such as brain, pituitary and hypothalamus, to stimulate the mitosis of cultured cells. Numerous shorthand names have been applied to active factors in these extracts, including epidermal growth factor, platelet-derived growth factor, nerve growth factor, hematopoietic growth factor and fibroblast growth factor.
Fibroblast growth factor (FGF) was first described by Gospodarowicz in 1974 (Nature 249: 123-127) as derived from bovine brain or pituitary tissue which was mitogenic for fibroblasts and endothelial cells. It was later noted that the primary mitogen from brain was different from that isolated from pituitary. These two factors were named acidic and basic FGF, respectively, because they had similar if not identical biological activities but differed in their isolectric points. Acidic and basic fibroblast growth factors (recently reviewed by Burgess, W. H., and Maciag, T. Ann. Rev. Biochem. 58: 575-606 (1989)) appear to be normal members of a family of heparin-binding growth factors that influence the general proliferation capacity of a majority of mesoderm- and neuroectoderm-derived cells (Gospodarowicz, D., et al., Nat. Cancer Inst. Mon. 48:109-130 (1978)), including endothelial cells, smooth muscle cells, adrenal cortex cells, prostatic and retina epithelial cells, oligodendrocytes, astrocytes, chrondocytes, myoblasts and osteoblasts (Burgess and Maciag, cited above at page 584). Although human melanocytes respond to the mitogenic influences of basic fibroblast growth factor but not acidic FGF most avian and mammalian cell types respond to both polypeptides (ibid.).
In addition to eliciting a mitogenic response that stimulates cell growth, fibroblast growth factors can stimulate a large number of cell types to respond in a non-mitogenic manner. These activities include promotion of cell migration into wound areas (chemotaxis), initiation of new blood vessel formation (angiogenesis), modulation of nerve regeneration (neurotropism), and stimulation or suppression of specific cellular protein expression, extracellular matrix production and cell survival important in the healing process (Burgess and Maciag, cited above, pages 584 to 588).
These properties, together with cell growth promoting action, provide a basis for using fibroblast growth factors in therapeutic approaches to accelerate wound healing and in prevention and therapeutic applications for thrombosis, artheriosclerosis, and the like. Thus, fibroblast growth factors have been suggested to promote the healing of tissue subjected to trauma (Davidson, J. M., et al. J. Cell Bio. 100:1219-1227 (1985)), to minimize myocardium damage in heart disease and surgery (U.S. Pat. Nos. 4,296,100 and 4,378,347 to Franco), and to increase neuronal survival and neurite extension (Walicke, P., et al., Proc. Nat. Acad. Sci. USA 83: 3012-3016 (1986)).
Complementary DNA clones encoding human acidic and human and bovine basic fibroblast growth factors have been isolated and sequenced, and the predicted amino acid sequences derived from the complementary DNAs agree with the structures determined by protein sequence analysis (summarized by Burgess and Maciag, cited above, at pages 580-581). The data predict acidic fibroblast growth factor (hereafter referred to as aFGF) to have 155 amino acids (ibid). The gene for basic fibroblast growth factor (hereafter referred to as bFGF) also codes for a 155 residue protein. For both aFGF and bFGF N-terminally truncated forms that exhibit full biologic activity including a 146-amino acid bFGF originally isolated and sequenced (Esch, F., et al, Proc. Nat. Acad. Sci. USA 82 6507-6511 (1985)) and a 131-amino acid form. Analysis of the structures demonstrates a 55% identity between aFGF and bFGF (Burgess and Maciag, cited above at page 581).
Basic fibroblast growth factor may be extracted from mammalian tissue, but this requires several steps even when heparin-linked affinity chromatography is employed (U.S. Pat. Nos. 4,785,079 and 4,902,782 to Gospodarowicz, et al.), and the 146-amino acid species is generally obtained if extraction is done in the absence of protease inhibitors (ibid., column 9, lines 29 to 32). Bovine and human basic fibroblast growth factor cDNA have been expressed in E. coli (Iwane, M., et al., Biochem. Biophys. Res. Commun. 146:470-477 (1987) and Squires, C. H., et al., J. Biol. Chem. 263:16297-16302 (1988)) and S. Cervisiae (Barr, P. J.. et al., J. Biol. Chem. 263: 16471-16478 (1988)). However, reported yields of product are low (see Eur. Pat. Ap. Pub. No. 228,449 to Esch, et al., page 18), and recombinant factors exhibit a marked tendency to undergo thiol-disulfide interchanges promoted by free thiol groups in the protein that result in the formation of disulfide scrambled species (Iwane, cited above).
A number of basic fibroblast growth factor analogues have been suggested. Muteins of bFGF having amino or carboxyl terminal amino acids deleted, amino acids added, cysteine substituted with a neutral amino acid such as serine, or aspartic acid, arginine, glycine, serine, or valine substituted with other acids have been suggested to have enhanced stability (Eur. Pat. Ap. Pub. No. 281,822 to Seno, et al., page 4, lines 1 to 3, and page 6, line 29 to page 7, line 19); the muteins comprise two or three additions, deletions or substitutions, with substitution of serine for cysteine the most preferred substitution (page 7, lines 18 to 23). Arakawa and Fox (Eur Pat. Ap. Pub. No. 320, 148) suggested replacing at least one, and more preferably two, of the cysteines found in natural bFGF with a different amino acid residue to yield a more stable analogue (page 4, lines 44 to 47); serine was illustrated in the Examples (page 13, lines 22 to 23), but alanine, aspartic acid and asparagine were also suggested (page 5, line 26 and page 13, line 25). Similarly, recombinant aFGFs having extraneous bond-forming cysteine replaced with serine, and oxidation-prone cysteine, methionine and tryptophan replaced with alanine, valine, leucine or isoleucine, to yield factors having enhanced or improved biological activity have also been suggested (Eur. Pat. Ap. Pub. No. 319,052 to Thomas Jnr and Linemeyer, page 17, lines 8 to 20).
A bFGF mutein lacking 7 to 46 amino acids from the carboxyl terminus and, optionally, having amino acids replacements was suggested to have improved stability while retaining activity in Eur. Pat. Ap. Pub. No. 326,907 to Seno, et al. (page 2, line 50 to page 3, line 4). Fiddes, et al, (Eur. Pat. Ap. Pub. No. 298723) suggested replacing basic or positively charged residues in the heparin binding domain encompassing residues 128 to 138 with neutral or negatively charged amino acids to produce forms of FGF having reduced heparin binding ability and enhanced potency (page 5, line 45, and page 5, line 54 to page 6, line 16). Bergonzoni, et al., suggested six analogues: 1) M1-bFGF, lacking residues 27 to 32; M2-bFGF, lacking residues 54 to 58; M3-bFGF, lacking residues 70 to 75; M4-bFGF, lacking residues 78 to 83; M5 -bFGF, lacking residues 110 to 120; M5a-bFGF, having the position 128 lysine and the position 129 arginine replaced with glutamine residues; and M6b-bFGF, having the positions 119 and 128 lysines and the positions 118 and 129 arginines replaced by glutamine residues (Eur. Pat. Ap. Pub. No. 363,675, column 6, line 48 to column 7, line 13).
However, new stable and active forms of fibroblast growth factors are increasingly sought to use in the therapies indicated hereinabove.


A signal processing apparatus for generating a noise cancellation signal in accordance with a noise signal includes an inverting circuit and a selecting circuit. The inverting circuit is employed for inverting a first signal to generate an inverted first signal. The selecting circuit is coupled to the inverting circuit, and employed for selecting one of the first signal and the inverted first signal as an output signal.

1. Field of the Invention
The present invention relates generally to signal processing, and more particularly, to a signal processing apparatus for performing active noise control.
2. Description of the Prior Art
The concept of active noise control method is to generate an 'anti-noise', which has an amplitude that is substantially identical to a noise source in the environment, but is substantially opposite in phase to the noise source (in practice, the anti-noise may only be similar to the noise source in the low frequency part). By superposition of the sound wave, the noise source and the anti-noise destructively interfere with each other, thereby eliminating the noise. This technology is generally used in a variety of loudspeaker devices, such as headphones. When a user is listening to audio materials via a loudspeaker, the loudspeaker device simultaneously produces the anti-noise by mixing an audio signal corresponding to audio materials with a noise cancellation signal corresponding to the anti-noise. As a result, the user will not be aware of the noise, and the listening experience will be improved. Conventionally, active noise control technology can be implemented by the circuit shown in FIG. 1.
A conventional noise cancellation apparatus illustrated in FIG. 1 includes an acoustic-to-electric transducer 11 (e.g. a microphone), an analog-to-digital converter 12, a filtering circuit 13 and a digital-to-analog converter 14. The acoustic-to-electric transducer 11 is employed for recording noises in the environment, and uses piezoelectricity generation to generate an electrical analog noise signal. The analog-to-digital converter 12 converts the analog noise signal into a digitalized noise signal. The digitalized noise signal will be passed to the filtering circuit 13, which filters the digitalized noise signal based on a transfer function depending on how much of the noise is actually received by the user, to generate a noise cancellation signal which is used to destructively interfere with the noise. An output of the filtering circuit 13 may be further converted to an analog signal by the digital-to-analog converter 14. The analog signal will be processed by an electric-to-acoustic transducer 15 to generate an analog noise cancellation signal. The analog noise cancellation signal will be mixed with an audio signal intended for playback by a mixer 16. After mixing, the user will be unaware of noises in the environment while listening to the audio.
This circuit architecture has certain problems, however. For example, under the consideration of signal gain, the analog signal may be processed by more than one amplifying stage, which may include inverse amplifying stages, before being transmitted to the mixer 16 or the electric-to-acoustic transducer 15. This may cause the analog noise cancellation signal to be inverted twice, which will result in the signal constructively interfering with the noise. Since the purpose of the analog noise cancellation signal is to destructively interfere with the noise, the conventional noise cancellation apparatus is unable to resolve this problem.


An address comparator circuit includes a first determination unit suitable for activating a first control signal when a first address corresponding to a previous read command is identical with a second address corresponding to a current read command; a second determination unit suitable for activating a second control signal when the previous and current read commands are consecutively inputted to the address comparator circuit with an interval of a specific number of clocks or less; and a blocking signal generation unit suitable for generating a blocking signal that blocks data transmission between a memory array and an external device based on the first and the second control signals.

1. Field
Exemplary embodiments of the present invention relate to an address comparator circuit, a memory device including the same, and a memory system including the memory device.
2. Description of the Related Art
A memory device stores external data and outputs the stored data. The memory device includes data input/output (I/O) lines along which data is transmitted. The data I/O lines include a global I/O line that transfers data between a data I/O pad and memory banks and that is shared by the memory banks and local I/O lines included in the respective memory banks. The transfer of data in a memory device is described below.
FIG. 1 is a diagram schematically illustrating the data I/O path of a memory device.
A write operation in which external data is received is described. Data inputted through a data pad DQ is loaded onto a global I/O line GIO via a reception circuit 102. When a first bank 110 is selected, the data on the global I/O line GIO is loaded onto the local I/O line pair LIO_B0 and LIOb_B0 coupled to the first bank 110 by a write driver 112. The data loaded onto the local I/O line pair LIO_B0 and LIOb_B0 is written in a selected memory cell within the first bank 110. When the second bank 120 is selected, the data of the global I/O line GIO is loaded onto the local I/O line pair LIO_B1 and LIOb_B1 of the second bank 120 by the write driver 122 and then written in a selected memory cell within the second bank 120.
A read operation in which data is output by a memory device is described below. When the first bank 110 is selected, data stored in a selected memory cell within the first bank 110 is loaded onto the local I/O line pair LIO_B0 and LIOb_B0, and then loaded onto the global I/O line GIO amplified by an I/O sense amp 111. The data on the global I/O line GIO is output to the outside of the memory device by a transmission circuit 101. When the second bank 120 is selected, data stored in a selected memory cell within the second bank 120 is output to the outside of the memory device through the local I/O line pair LIO_B1 and LIOb_B1, an I/O sense amp 121, the global I/O line GIO, and the transmission circuit 101.
FIG. 2 is a diagram illustrating an active operation and a read operation of a word line and a bit line. FIG. 2 shows a problem occurring when the read operation is repeatedly performed on a single memory cell.
Referring to FIG. 2, at a first point of time 201, the word line WL is activated in response to an active command. When the word line WL is activated, the data of a memory cell corresponding to the word line WL is loaded onto a bit line pair BL and BLb. As shown in FIG. 2, a voltage level of the primary bit line BL is higher than that of the secondary bit line BLb due to charge sharing between the memory cell and the bit line pair BL and BLb. At a second point of time 202, a bit line sense amp is activated, and a small potential difference between the bit line pair BL and BLb is amplified by the bit line sense amp. As a result, the primary bit line BL has the same level as a core voltage VCORE, i.e., a voltage of a high level used in a cell region, and the secondary bit line BLb has the same level as a ground voltage VSS.
Third to fifth points of time 203 to 205 denote sections in each of which a read operation is performed in response to a read command. In the section in which the read operation is performed, the voltage level of the bit line pair BL and BLb is transferred to the local I/O line pair LIO and LIOb. That is, the local I/O line pair LIO and LIOb may be driven by the bit line pair BL and BLb. Accordingly, the voltage level of the primary bit line BL drops, and the voltage level of the secondary bit line BLb rises. The changed voltage level of the bit line pair BL and BLb recovers to the original level by a sense amp. When the above-described read operations are consecutively repeated during the sections denoted by the third to fifth points of time 203, 204, and 205 as shown in FIG. 2, the voltage level of the bit line pair BL and BLb does not recover to the original level and the voltage difference between the bit line pair BL and BLb is gradually reduced. As a result, the voltage levels of the bit line pair BL and BLb are reversed as shown in the last section denoted by the fifth point of time 205, which cause a read fail.
The consecutive repetition of read operations is frequently performed on the same memory cell while a memory device operates. Accordingly, there is a need to prevent fails that are attributable to the consecutive repetition of read operations on the same memory cell.

Address comparator circuit for generating transmission control signal, memory device and memory system including the same


Methods are provided for adaptive optimization of enhanced oil recovery project performance under uncertainty. Predictive physics-based reservoir simulation is used to estimate performance of the project. Input parameters of the model are divided into control variables and uncertain variables. The reservoir model is optimized to obtain values of control variables maximizing mean value of a chosen performance metric under initial uncertainty of formation and fluid properties. An efficient frontier can characterize dependence between the optimized mean value of the performance metric and its uncertainty expressed by the standard deviation. Global sensitivity analysis (GSA) is then applied to quantify and rank contributions from uncertain input parameters to the standard deviation of the optimized values of the performance metric. Additional measurements can be performed to reduce uncertainty in the high-ranking parameters. Constrained optimization of the model with reduced ranges of uncertain parameters is performed and a new efficient frontier is obtained.

Enhanced oil recovery allows for higher recovery efficiency which could not be achieved by traditional recovery mechanisms. An oilfield installation for EOR is seen in prior art FIG. 1 which shows an EOR installation 13 including an injection well 30 and a production well 38. During an EOR process, injection fluid 43 is injected through the injection well 30 into a reservoir formation 46 and establishes a fluid front 47 that moves through a rock matrix within the reservoir formation 46. The injection fluid 43 increases pressure within the reservoir formation, mobilizes bypassed oil and forces hydrocarbons toward the production well 38. The location of the fluid front 47 may be monitored by various means such as a monitoring well (not shown).
EOR performance is evaluated using prescribed performance metrics (e.g., incremental oil production, recovery factor, displacement efficiency, financial indicators of project profitability, etc.) computed by running a reservoir simulation. For example, EOR performance may be predicted using numerical simulations such as ECLIPSE (a trademark of Schlumberger), or a more specialized tool such as the one disclosed by U.S. Pat. No. 8,311,743 to Gurpinar entitled "Method for Generating an Estimation of Incremental Recovery From a Selected Enhanced Oil Recovery (EOR) Process" which is hereby incorporated by reference herein in its entirety. The tool receives inputs relating to the well locations, production/injection schedule, formation and fluid properties, selected EOR process etc., and provides a prediction of the EOR performance including total and incremental oil produced, recovery factor, displacement efficiency, etc.
In the presence of uncertainty in formation and fluid properties, optimal EOR strategies will result in inherently uncertain predictions of a prescribed performance metric. A standard approach to optimization under uncertainty is based on original Markovitz portfolio theory and more recently was tailored to oilfield applications with a modified definition of efficient frontier. See, U.S. Pat. No. 6,775,578 to B. Couet, et al. entitled "Optimization of Oil Well Production with Deference to Reservoir and Financial Uncertainty" which is hereby incorporated by reference herein in its entirety, and Raghuraman, B., et al., "Valuation of Technology and Information for Reservoir Risk Management," SPE 86568, SPE Reservoir Engineering, 6, No. 5, pp. 307-316, October 2003. These methods employ a mean-variance approach. Including sensitivity analysis in an optimization under uncertainty workflow is shown U.S. Patent Application Publication No. 2010/0185427 by P. Tilke et al. The sensitivity is defined for a figure of merit with respect to uncertain formation properties and computed using an experimental design approach. Value of information is then computed based on a mean-variance objective function related to a figure of merit.

Methods for adaptive optimization of enhanced oil recovery performance under uncertainty


A clamp for clamping a body structure in a patient. The clamp includes a flexible cable housed within a sheath. The cable and sheath extend between a clamp and a handle. The cable actuator. The cable extends through a sheath which is anchored at the clamp and the actuator for actuating jaws from a proximal end of the clamp. A malleable positioner is provided for positioning the clamp about the body structure.

Various cardiovascular, neurosurgical, pulmonary, and other interventional procedures, including coronary artery bypass grafting, heart valve repair and replacement, septal defect repair, pulmonary thrombectomy, removal of atrial myxoma, patent foramen oval closure, treatment of aneurysms, myocardial drilling, electrophysiological mapping and ablation, angioplasty, atherectomy, correction of congenital defects, and other interventional procedures may require general anesthesia, cardiopulmonary bypass, and arrest of cardiac function. In order to arrest cardiac function, the heart and coronary blood vessels must be isolated from the remainder of the circulatory system. This serves several purposes. First, such isolation facilitates infusion of cardioplegic fluid into the coronary arteries to perfuse the myocardium and paralyze the heart without allowing the cardioplegic fluid to be distributed elsewhere in the patient's circulatory system. Second, such isolation facilitates use of a cardiopulmonary bypass system to maintain circulation of oxygenated blood throughout the circulatory system while the heart is stopped without allowing such blood to reach the coronary arteries and resuscitate the heart. Third, in cardiac procedures, such isolation creates a working space into which the flow of blood and other fluids can be controlled or prevented so as to create an optimum surgical environment.
Circulatory isolation of the heart and coronary blood vessels is usually accomplished by placing a mechanical cross-clamp externally on the ascending aorta downstream of the ostia of the coronary arteries, but upstream of the brachiocephalic artery so that oxygenated blood from the cardiopulmonary bypass system reaches the arms, neck, head, and remainder of the body. Using conventional techniques, the sternum is cut longitudinally (a median sternotomy) thereby providing access between opposing halves of the anterior portion of the rib cage to the heart and other thoracic vessels and organs. Alternatively, a lateral thoracotomy is formed, wherein a large incision is made between two ribs and the ribs are retracted apart. A portion of one or more ribs may be permanently removed to optimize access.
Through this large opening in the chest, a cross-clamp is placed externally on the ascending aorta thereby isolating the heart and coronary arteries from the remainder of the arterial system. Frequently, the aorta must be dissected away from adjacent tissue to facilitate placement of such a cross-clamp.
To arrest cardiac function, a catheter is introduced through the sternotomy or thoracotomy and inserted through a puncture in the aortic wall into the ascending aorta between the cross-clamp and the aortic valve. Cardioplegic fluid is infused through the catheter into the aortic root and coronary arteries to perfuse the myocardium. An additional catheter may be introduced into the coronary sinus for retrograde perfusion of the myocardium with cardioplegic fluid. In addition, the myocardium is sometimes cooled by irrigation with cold saline solution and/or application of ice or cold packs to the outside of the heart. Cardiac contractions will then cease.
In surgical procedures requiring a median sternotomy or other form of gross thoracotomy, the ascending aorta is accessible for placement of an external cross-clamp through the large opening in the chest. However, such open-chest surgery often entails weeks of hospitalization and months of recuperation time as well as pain and trauma suffered by the patient. Moreover, the average mortality rate associated with this type of procedure is about two to fifteen per cent for first-time surgery, and mortality and morbidity are significantly increased for reoperation.
New devices and methods are therefore desired to facilitate the performance of cardiac procedures such as heart valve repair and replacement, coronary artery bypass grafting, and the like, using minimally invasive techniques, eliminating the need for a gross thoracotomy. Such techniques are described in U.S. Pat. No. 5,452,733, and application Ser. No. 08/163,241 filed Dec. 6, 1993, now U.S. Pat. No. 5,571,215, which are assigned to the assignee of the present invention and are incorporated herein by reference. In those applications, methods and devices are described for performing coronary artery bypass grafting, heart valve repair and replacement, and other procedures through small incisions or cannulae positioned in the chest wall, obviating the need for a gross thoracotomy. One technique described for arresting the heart during such procedures involves the use of a catheter which is introduced into a peripheral artery such as a femoral artery and positioned in the ascending aorta. An expandable member at the distal end of the catheter is expanded within the ascending aorta to block blood flow therethrough. Cardioplegic fluid is then be infused into the aortic root and into the coronary arteries through a lumen in the catheter, and/or in a retrograde manner through a catheter positioned in the coronary sinus, paralyzing the myocardium.
While this endovascular technique for arresting the heart provides. significant advantages over conventional open-chest techniques, in some circumstances the use of an endovascular device for aortic partitioning may be undesirable. For example, in some cases the patient's femoral arteries and other vessels in which such a device could be introduced may not be suitable for such introduction, due to inadequate vessel diameter, vessel stenosis, vascular injury, or other conditions. In addition, where a number of endovascular cannulae are to be introduced to support cardiopulmonary bypass, retroperfusion of cardioplegic fluid, removal of blood from the heart, and other functions, a suitable arterial location for introduction of an endovascular aortic partitioning device may not be available. Further, it may be desirable to minimize the number of arterial punctures so as to reduce the risk of infection and other complications stemming from such punctures.
The present invention also provides an improved method and apparatus for clamping a patient's internal mammary artery for performing a coronary artery bypass procedure. In order to use a mammary arterial graft in a coronary artery bypass procedure, blood flow through the target mammary artery is temporarily stopped using a removable surgical clamp. In a conventional open-chest procedure, a relatively large, easy to handle clamp is applied by hand or with a forceps directly to the mammary artery through the large opening in the patient's chest provided by a median sternotomy. After the mammary artery is clamped, the mammary artery is ligated and divided at a location downstream from the clamp to create a free end which is connected to the coronary artery. After the grafting is complete, the clamp is removed by the surgeon, typically by hand or with the open forceps, to permit blood to flow through the mammary artery and into the coronary artery downstream of the blockage. As discussed above, gross thoracotomies used in conventional open heart surgery are highly traumatic to the patient and, therefore, new methods of performing surgery on the heart using minimally-invasive techniques have been recently developed. A further application of the present invention is for clamping the internal mammary artery for performing a coronary artery bypass procedure when performing minimally invasive heart surgery.


An improved portable golf cart enclosure design featuring a top and two sides that wrap around a typical golf cart to protect occupants from wind, rain and cold. The improved enclosure features a roll-on and roll-up design that improves the installation and removal task over traditional golf cart enclosures. Finally, this invention improves ingress and egress through a horizontal swing away magnetic door design.

This invention relates generally to the field of portable soft golf cart enclosures, specifically to a golf cart enclosure design that easily wraps over the permanent cart roof, around an installed front windshield and adapts to an accessible rear club cover canopy. This design is easier for a person to install, remove and prepare for storage. The invention features a unique door opening technique that quickly and reliably opens and closes to protect the passengers from wind, rain and cold, while also improving entry and exit convenience.
Golf cart enclosures are utilized today to protect the occupants from wind, rain and cold. The enclosures generally cover cart windshields and openings in front, sides and rear with vinyl, cloth or other materials.
Golf carts typically have a hard top roof to protect the occupants from the sunlight. Golf cart enclosures generally attach to or are supported by the cart roof and have side panels that are secured to the body of the cart
Golf cart enclosures today are one of two types. One type is installed semi-permanently and remains on throughout the cold weather season. The second type is portable and loosely shaped to fit most cart manufacturers. The portable enclosures tend to be either over-the-roof models with four sides or under-the-roof models with three sides.
Most portable patented golf cart enclosure products in the market today, are four sided and slip over the entire golf cart frame. This process typically requires two people to install and remove for storage and becomes more difficult in high wind conditions.
A second patented design has three sides and attaches under the cart roof using straps or rails. This design requires significant installation time and effort to make the necessary connections and is not intended to be portable.
A third patented design attaches to the roof front support bars and rear roof support bars and is easily removable after a installing a semi-permanent fitting on the front roof support bars.
Most enclosures use zippered openings that typically have a closed end at the top to ensure the zippers can be reliably opened and closed. This closed end results in a very small opening for ingress and egress. The zippers must accommodate different degrees of tension to accommodate the different sizes and shapes of golf cart models, which affects in zipper performance during closing and opening and usually causes zipper failure over time.
Most golf cart enclosures have doors or sides that unzip and roll-up during good weather to enable easier ingress and egress. This vertical roll-up process was implemented to allow for airflow during improved weather and to enable easier ingress and egress.
Golf cart zippers are inherently unreliable. Because zippers are mechanical, they are prone to break, snag and tear. Most portable enclosures when installed can stretch a door side, which adds tension on the zippers and contributes to door zipper failure. The zipper teeth can get out of alignment and fail. Zippers also tend to separate from material over time, due to shrinking, caused by tension and weather. In short, there is a high probability that zippers will jam or fail over time.
Most golf cart enclosures today are sold in a storage bag, which is usually sized and shaped to create a small compact package for shipment and sale. This approach makes it difficult to re-fold the enclosure and place it in the original bag. As a result, most owners dispense with using the storage bag.
Therefore, a small portable golf cart enclosure that is easier to install, remove, and pack for storage and provides an improved method of ingress and egress is desired and needed.

2-sided golf cart enclosure with magnetic door


A method and apparatus for tracking a location of an object or target in a 3D space. At least one target including unique sub-targets is attached to a vision object in the 3D space. A camera disposed in a 3D space, and coupled to a computing device captures a 2D image of a target. The camera computing device identifies the sub-targets of the target and transfers the sub-target data to a computing device associated with the camera which accesses a data base of target data to identify target an, using sub-target separation distances in the database to determine 3D location and orientation of the target. Another computing device transforms the 3D locations of the detected target in the camera coordinate system into a single 3D coordinate system for the 3D space. The 3D location of targets detected by multiple cameras of different computing devices maybe daisy chained together to convert the target location in the 3D coordinate systems of each computing device into a single 3D coordinate system.

The disclosure concerns the use of "rich colored transition sequences" (RCTS) together with multi camera optical tracking within a 3D space for control of computer applications or measurement and collection of 3D data.
It has always been a dream in the machine vision community to track objects in 3D with a multitude of cameras. There is no end to applications that could benefit from seamless multi-camera optical tracking: gaming, robotics, medical care, surgery, home control, etc. Moore's Law is driving the price point and capability of computers, cameras, and communication to a point where this may soon be possible. Some of the barriers to widespread adoption are addressed here.
Usually the assumption is made that all positions in a 3D volume need to be visible to at least two cameras at all times. This leads to a complex optimization problem especially when people can move around the space and occlude some of the cameras. Implicit in this is the need to synchronize all of the cameras with overlapping fields of view.
The associated computational and mathematical problems grow dramatically as the number of cameras increase. Photogrammetry using two cameras was never easy but it gets much tougher when three or more cameras are used on the same field of view especially when some cameras see the object from a different side and angle, and lighting changes as clouds pass by, and people pass in from of cameras. The burden on computers can be horrific.
This method and apparatus, together with the three previous patents of the inventor extensively disclose how targets of color can be used to build fast, robust and inexpensive machine vision interfaces. The next three paragraphs below are a brief and incomplete summary of these three patents where many of the relevant elements of the past work is discussed.
U.S. Pat. No. 8,064,691, explains how colored targets could be composed of rich colors that were far more reliable in variable lighting environments. The rich color method was fast and would greatly benefit when future cameras move beyond the three RGB sensors of today.
U.S. Pat. No. 8,526,717, discloses how the method is greatly enhanced when the transition boundary curves that separate rich colored patches are used for tracking. The transition curves that separate rich colors rarely occur in a given image and if search is limited to a relatively small number of ordered adjacent sets of curves of a given shape bounded by specific color pairs, we have a robust, fast tracking method that requires little computer memory. This can easily be implemented in hardware or software of a smart camera. An example of an everyday smart camera is an iPhone or iPad where a software app could perform many tasks.
U.S. patent application Ser. No. 14/014,936, explains how a sequence of sub-targets that are arrayed along a roughly straight line path can provide an almost unlimited number of IDs. These sequences act as a single target which can be used to detect, ID, locate, and orient a rigid object to which the sequence is attached. Further, this patent shows how multiple cameras and computers can gather location and orientation data about each sequence and applications can be constructed in a modular fashion such that a pair of lists can control a wide set of machine vision applications. This so called "see-this" and "do-that" lists are all that are needed to pick an app and guide it's action.

Implementation of multi-camera tracking applications using rich color transition curve target sequences


An improved clamp device having interchangeable quick release clamping members, said clamping members being moveable relative to the jaws of the device and being magnetic so as to retain the clamp device to a ferro-metallic work piece. The improvements allow increased flexibility of the device over traditionally configured clamps with regard to use of the device with difficult work pieces and environments. The interchangeable clamping members allow a single device to be used for multiple applications, thereby making the invention a low cost and convenient alternative to multiple special purpose tools, as well as permitting quick and inexpensive replacement of wear elements.

1. Technical Field
The invention relates generally to the field of hand tools. More specifically, the invention is directed to an improved magnetic clamp device suitable for use with difficult work pieces and environments.
2. Description of Prior Art
Clamps are well-known in the art. Vise-Grip™ brand locking pliers are an example. Such clamps include a handle mechanism, a clamping mechanism manipulated by the handle mechanism, and a locking mechanism suitable for retaining the clamping mechanism in a fixed position relative to a work piece. There many different known methods for implementing these basic structures, for which myriad patents have been issued. The great majority of these prior patents involve various improvements or modifications to the locking mechanisms. Others disclose locking pliers with internal springs to provide tension and a thumb catch for locking/unlocking the tool. Other patents disclose mechanisms for adjusting the angle of the jaws of the clamping mechanisms to accommodate different sizes of work pieces to be gripped. Yet other patents involve tools having jaws which move in relation to the handle mechanisms.
None of the disclosed prior art offers all of the functionality disclosed in the present invention. Moreover, the implementation of similar individual concepts in earlier patents differs significantly with the implementation of the present invention. Thus none of the disclosed prior art anticipates the present invention.
It is an objective of the present invention to provide a useful, improved clamp device with quick release interchangeable clamping members.
It is a further objective of the present invention to provide a useful, improved clamp device with clamping members moveable relative to the jaws to better accommodate work pieces.
It is a further objective of the present invention to provide a useful, improved clamp device with a magnetic clamping member to hold the device onto a ferro-metallic work piece.
It is a further objective of the present invention to provide a useful, improved clamp device with variously shaped clamping members suitable for use with difficutly situated work pieces.
Other objectives of the present invention will be readily apparent from the description that follows.


A spindle motor having a turntable is disclosed, the spindle motor including a rotating rotation shaft, a turn table coupled to the rotation shaft to rotate along with the rotation shaft, and formed at a central upper surface with an accommodation groove, and a torque enhancement member coupled to the rotation shaft, and arranged inside the accommodation groove of the turn table to enhance a rotational torque of the turn table by depressing the turn table.

Field of the Invention
The present disclosure relates to a spindle motor.
Description of Related Art
Generally, a spindle motor, one of disk rotating devices, is widely used as an optical disk drive (ODD) and a hard disk drive for rotating an optical disk and a metal disk at a very high speed.
The spindle motor for rotating an optical disk in the ODD at a high speed includes a rotation shaft, a turn table rotating with the rotation shaft, and a center cone inserted into the rotation shaft to center the disk.
The spindle motor thus configured is reduced in thickness of turn table by the center cone, thereby reducing a coupling force between the turn table and the rotation shaft. The reduction in coupling force between the turn table and the rotation shaft may tilt the turn table, generate a rotational run-out, or greatly reduce a rotational torque of the turn table, whereby various problems including a rotational slip of the turn table may disadvantageously generated.


There is provided an engineering change order (ECO) cell, which includes: a function circuit including at least one PMOS transistor with a P-diffusion layer and a first poly gate, at least one NMOS transistor with an N-diffusion layer and a second poly gate; a first power layer supplying the at least one PMOS transistor with a first power voltage; and a second power layer supplying the at least one NMOS transistor with a second power voltage. The first poly gate of the PMOS transistor is isolated from the second poly gate of the NMOS transistor.

1. Technical Field
The present invention relates to an engineering change order (ECO) cell and a method for arranging and routing the same.
2. Description of the Related Art
A standard cell type LSI design engineering is widely used as a layout design engineering for implementing a large scale integrated circuit (LSI) having high integration on a semiconductor substrate for a short period of time. In the standard cell type LSI design engineering, a small unit circuit, such as an inverter and a NAND gate, is prepared as the standard cell, and the standard cell is arranged in array form and is connected to each other to form the LSI.
Hereinafter, an ECO cell in accordance with the related art will be described in more detail with reference to the accompanying drawings.
FIG. 1 shows a layout of a standard cell type LSI in accordance with the related art, and FIG. 2 shows an inner pattern view of a standard cell in accordance with the related art.
As shown in FIG. 1, a plurality of cell arrays are arranged, and each of cell arrays is formed by a plurality of standard cell 1006 having the same width (in other words, depth in drawings) and is arranged in array form.
A routing channel 1801 is arranged between the neighboring standard cell arrays. An inner-cell connection unit 1802 for connection between standard cells is included in the same standard cell array and an inter-array connection unit 1803 for connection between standard cells is included in different standard cell arrays which are located on routing channel 1801.
An ECO cell is provided in a design based on the standard cell library
The ECO cell in accordance with the related art will be described in more detail with reference to FIG. 2.
As shown in FIG. 2, ECO cell 200 includes a VDD power layer 202 for a VDD power supply, an N-diffusion layer 205 for a pick-up and a first contact hole 204, which connects VDD power layer 202 with N-diffusion layer 205, in an N-well 201.
A lower side of ECO cell 200 includes a VSS power layer 211 for a VSS power supply, a P-diffusion layer 210 for a pick-up and a second contact hole 209, which connects VSS power layer 211 with P-diffusion layer 210, and has an N-diffusion layer 208 and a poly gate 206 for making an NMOS included in various circuits.
Here, the NMOS poly gate and the PMOS poly gate are formed to be a single body.
However, the ECO cell in accordance with the related art has a problem as described below.
As described above, in the case that the cell library is used in the ECO cell, since a size of the cell library is predetermined, the flexibility is limited in a place step of the standard cell. Moreover, since a junction capacitance of the transistor is increased, the performance of the cell library used in the ECO cell will not be good.
In detail, since the ECO cell library having a fixed width is adapted in a cell library layout and a grid based auto place and root (P&R) tool is adapted, the flexibility of a cell layout is lowered.
Moreover, a connection between the PMOS of the ECO cell and the gate electrode of the NMOS is limited to generate various logic functions.
Accordingly, it is limited to respond to a request of a designer.

Engineering change order cell and method for arranging and routing the same


A system and method of generating a set of circuit simulation data, applying data mining to for knowledge extraction from the data, and graphically presenting the extracted knowledge in a format that is easy to digest to a designer.

Software tools are frequently used in the design of analog, mixed-signal and custom digital circuits. In front-end design for yield, designers choose device sizes such that the maximum possible percentage of manufactured chips meets all specifications (i.e., such the yield is maximized). The designer may have aims to improve performance as well (i.e. have more aggressive specifications). In order to effectively design such circuits, designers need insight into the design. Specifically, the designers need insight into how topology choice, device sizes, and layout affect performances and yield of the circuits in question. Current techniques to provide this insight include: examination of circuit schematics, manual derivation of modeling equations, and circuit simulation. These techniques typically divide the problem into the creation of data on which an analysis can be based, and on the visualization used to represent the data.
The data is often created using simulations making use of circuit simulation/analysis tools such as SPICE. The datasets generated can be generated in one of many possible ways. Examples of such common ways follow. The data set can be based on evaluating the performance of a single design point (e.g., device sizes), single random point (e.g., as drawn from a probability density function that approximates manufacturing variations), and single environmental point (e.g., specific setting for temperature & load). Alternatively, the data can be based on single or nested sweeps across design variables of a given circuit design to provide a better data set with which to work. A single sweep might be: sweep across a set of values v1, . . . , vi, . . . vN for a specific design variable with every other design variable fixed. Following this, a simulation is performed at {design point i, the "nominal" random point, a "typical" environmental point} to output a set waveforms and of performance values, such as measures of power consumption and gain. This provides a data set that can be used in multiple ways as will be described below. A nested sweep might be: outer sweep is across a set of values v1, . . . , vi, . . . vN for a specific design variable with every other design variable fixed; then for each design point, there is an inner sweep across a set of user-defined environmental points pi, . . . , pj, . . . pM. This is followed by a simulation done at that {design point i, nominal random point, environmental point j} to obtain corresponding output performance values. Alternatively, for a given design point, a "Monte Carlo" simulation can be performed as follows: at a given design point, for each of a set or random points drawn from a probability density function, for each of a set of user defined environmental corners, simulate and extract performance values. Sensitivity analysis can also be performed about a design point, random point or environmental point by causing slight perturbations in corresponding design variables, random variables, and environmental variables respectively.
The data obtained is typically presented to the designer as either raw data or in a simple data aggregation. A more "raw" form (i.e., less-processed form) of the data might be a waveform, for example of a voltage vs. time, which would be output from a single {design point, random point, environmental point} in a transient analysis. Or, if the dataset is the result of a sweep of a design variable at N different values, then there may be N waveforms overlaid on a same plot. An example of slightly more processed data is to have a performance value (e.g., power consumption) presented as a function of a design variable, i.e., the result of a sweep across that the given design variable. The results of a nested sweep where an outer sweep has values of a design variable and an inner sweep has environmental points could be a plot of "worst case performance" versus design variable values, where "worst case performance" for a design point is the worst of all performance values across environmental points extracted for that design point. The results of a Monte Carlo simulation might be analyzed by estimating yield, as the percentage of random points that are feasible, where a random point is feasible only if all its worst-case-performances (across environmental points) met all performance specifications. Another more visual way to analyze Monte Carlo results would be in a 2d scatter plot, where each axis is for a worst-case-performance such as worst-case gain and worst-case power consumption. Then there is one point drawn on the scatter plot for each random point. Such a scatter plot is useful to visually identify correlations among performances.
These visualization methods are suitable for a small set of data, which results in a requirement to constrain the number of variables that can be adjusted, the range of the variables, and the depth of nesting. If such limitations are not imposed, the number of possible plots presented quickly becomes overwhelming for the designer. In modern designs, there are a large number of design elements where each element may have many design and random variables associated with it. This means that there can be a huge number of variables. For example, 10 random variables per device, and 100 devices, means 1000 random variables. Moreover, these variables can be nonlinearly coupled: for example, 1000 variables could have about 1,000,000 possible couplings. Despite this, the designer wants to, somehow, get insights into how to design the circuit. To try to understand the whole space of possible variables and their relations is an extremely complex task for a human Even if a dataset to describe a given could be generated via the traditional sweeps, etc., that dataset would be so huge that it would be unusable for human analysis. One possibility to provide the designer with a more compact data set is to limit the number and range of variables to be adjusted. This results in a manageable data set, and allows a certain degree of design optimization, but it requires some prior insight into which variables to limit. Therefore, the chance for optimality is lost and, there is a risk that important information will not be presented to the designer.
One problem faced by designers is that there is typically a complicated nonlinear relation from each component's design and random variables to each performance characteristic, and ultimately to yield. For example, not every component that has an effect on the performance characteristics of a design will have an effect on the yield of the manufacturing process. Without a tool to provide information identifying which elements have an effect on yield, designers may make performance-changing modifications without realizing any gain in yield.
Another problem faced by designers occurs when none of the topologies tried are able to meet target performances and yield. The designer may have even tried to apply an automated performance/yield optimizer to get the best possible designs, but to no avail. In this case, the designer may need to design a new topology. There are no industrially scalable automated topology design approaches, so topology design must be manual. Topology design requires deep insight into design and the issues related to past topologies, i.e., knowledge of why prior topologies that were tried did not work. A tool that provides information such as relative impacts of design variables and random variables on past topologies would be invaluable information to the designer as they try new topologies. Furthermore, such a tool would also be very useful in the new candidate topology designs that the designer attempts, to learn what its particular issues are.
Another problem is that the person who does the front-end design (e.g., topology selection or design, sizing) is often not the same person who does layout design. If they are different people, then the person doing the front-end design will have far more insight into the relative importance of variables/devices on performance (and to a lesser extent, yield) because that is where their training lies. But the person doing the layout design may still need to make changes, to resolve layout-related yield issues, parasitic issues, and more. Unfortunately, when they make changes to the design they may inadvertently affect the performance or the yield of the circuit, without realizing it. Further, even if they did notice the problem, they would not necessarily have the insight to know what they can and cannot change.
To improve the insight that designers have into their circuits, it would be very useful to have a mechanism to determine how much each individual device affects yield and/or performance; and to have that info across a range of design space broader than sensitivity analysis (which is by definition local). Further, a mechanism to determine the interactions between components and how they affect performance and/or yield would be very useful. It would also be very useful to know this information not only on a component-by-component basis, but also at the level of design variables (e.g., width), random variables (e.g., oxide thickness of a given device), and environmental variables (e.g., power supply voltage, load resistance, temperature, etc.).
Therefore, it is desirable to provide a tool for extracting and presenting information to a designer to convey how individual elements (devices or variables) can affect the performance and/or yield of an electrical circuit design. This desired tool should be able to perform on an element-by-element basis, or by taking into account coupling between elements. Furthermore, it is desirable to provide a general means for the designer to gain insight by extracting knowledge from circuit simulation data, including: identifying causal variable dependencies of circuit variables (and thus circuit devices too); identifying interesting clusters of circuit simulation data (e.g. clusters of metric values); reducing dimensionality into human-viewable dimensions; and visually representing the extracted knowledge.

Data-mining-based knowledge extraction and visualization of analog/mixed-signal/custom digital circuit design flow


A method and apparatus for driving an electro-luminescence display panel capable of preventing an initial blinking phenomenon occurring at a power application is disclosed. In the method, a first electrode of the EL cell and a ground voltage source are opened during a first period from a turn-on time of a power source to shut off a current path of the EL cells. Then, the first electrode of the pixel matrix and the ground voltage source is shorted during a second period to form a current path such that the EL cells are light-emitted in accordance with a data supplied to the pixel matrix.

1. Field of the Invention
This invention relates to an electro-luminescence display (ELD), and more particularly to a method and apparatus for driving an electro-luminescence display panel that is capable of preventing an initial blinking phenomenon occurring at a power application.
2. Description of the Related Art
Recently, there have been highlighted various flat panel display devices reduced in weight and bulk that is capable of eliminating disadvantages of a cathode ray tube (CRT). Such flat panel display devices include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) and an electro-luminescence (EL) display panel, etc.
The EL display panel of these display devices is a self-luminous device capable of light-emitting a phosphorous material by a re-combination of electrons with holes. The EL display panel is largely classified into an inorganic EL device using an inorganic compound as the phosphorous material and an organic EL device using an organic compound as it. Since such an EL display panel has many advantages of a low-voltage driving, a self-luminescence, a thin film type, a wide viewing angle, a fast response speed, and a high contrast, etc., it has been expected as a post-generation display device.
Generally, the organic EL device is comprised of an electron injection layer, an electron carrier layer, a light-emitting layer, a hole carrier layer and a hole injection layer that are sequentially disposed between a cathode and an anode. In such an organic EL device, if a desired voltage is applied between the cathode and the anode, electrons generated from the cathode are moved, via the electron injection layer and the electron carrier layer, into the light-emitting layer while holes generated from the anode are moved, via the hole injection layer and the hole carrier layer, into the light-emitting layer. Thus, the light-emitting layer emits a light by a re-combination of electrons and holes fed from the electron carrier layer and the hole carrier layer, respectively.
As shown in FIG. 1, an active matrix type EL display panel employing such an organic EL device includes a pixel matrix 20 having sub-pixels 28 arranged at each area defined by each intersection between gate lines GL and data lines DL, a gate driver 22 for driving the gate lines GL of the pixel matrix 20, a data driver 24 for driving the data lines DL of the pixel matrix 20, and a power supply 32 and a ground voltage source GND connected to the pixel matrix 20.
The gate driver 22 applies scanning pulses to sequentially drive the gate lines GL.
The data driver 24 supplies R, G and B data signals to each data line DL whenever the scanning pulse is applied. At this time, the data driver 24 converts digital data inputted from the exterior thereof into analog data signals. For instance, the data driver 24 voltage-divides a gamma reference voltage inputted from the exterior thereof into a plurality of gamma voltage levels, and selects the gamma voltage level corresponding to the input digital data to apply it as an analog data signal.
One pixel is implemented by a combination of the R, G and B sub-pixels 28. If the scanning pulse is applied to the gate line GL, then each of the R, G and B sub-pixels 28 receive a data signal from the data line DL to generate a light corresponding to the data signal. To this end, as shown in FIG. 2, each of the R, G and B sub-pixels 28 includes an EL cell OEL having a cathode connected to the ground voltage source GND, and a cell driver 30 connected to the gate line GL and the data line DL to control a current amount fed to an anode of the EL cell OEL from a power line PL, thereby driving the EL cell OEL.
The cell driver 30 includes a switching thin film transistor T1 having a gate terminal connected to the gate line GL, a source terminal connected to the data line DL and a drain terminal connected to a node N1, a driving thin film transistor T2 having a gate terminal connected to the node N1, a source terminal connected to the power line PL and a drain terminal connected to the EL cell OEL, and a storage capacitor C connected between the power line PL and the node N1.
If the scanning pulse is applied to the gate line GL, then the switching thin film transistor T1 is turned on to thereby apply a data signal supplied to the data line DL, via the node N1, to the gate terminal of the driving thin film transistor T2. At this time, the storage capacitor C charges a difference voltage between a driving voltage VDD supplied via the power line PL and the data signal supplied to the node N1. The driving thin film transistor T2 controls a current amount I fed from the power line PL to the EL cell OEL in response to a voltage supplied to the node N1, thereby controlling a light-emitting amount of the EL cell OEL. Further, when the switching thin film transistor T1 is turned off, the driving thin film transistor T2 supplies a constant current I until a data signal at the next frame is applied by a voltage charged in the storage capacitor C, thereby keeping a light-emission of the EL cell OEL.
In the conventional EL display panel having the above-mentioned configuration, as the power supply 32 is turned on, an initial driving voltage VDD is supplied to the pixel matrix 20 prior to an application of the data signal from the data driver 24. For this reason, since the EL cells OEL forms a current path by the initial driving voltage VDD suddenly supplied to the pixel matrix 20, there is raised a problem in that an initial blinking phenomenon occurs.

Method and apparatus for driving electro-luminescence display panel


A structural panel for use in building structures or in the formation, finish or decoration thereof includes an outer sheet and a connector sheet with a plurality of collapsible or compressible dividers therebetween. The panel in a rest condition is expanded and of a desired thickness for final use but can be compressed into a relatively thin thickness or profile for shipping purposes. The panel is very lightweight but structurally strong and can be selectively bent in one transverse direction if desired. The panel can be easily cut or formed into any predetermined size or shape.

1. Field of the Invention
A structural panel which finds particular uses as a ceiling panel or wall panel, includes an outer sheet having a plurality of spaced dividers protruding from one face thereof and a connecting sheet, or the like, parallel to and spaced from the outer sheet connecting the dividers together along their sides distal the outer sheet. The dividers are compressible for at least some period of time when pressure is applied thereto to reduce the thickness of the panel when desired, for example, for shipping purposes.
2. Description of the Relevant Art
Structural panels used in the finish or decoration of building structures have taken numerous forms from drywall to decorative or acoustical ceiling panels. While such panels obviously have different characteristics, the panels have had numerous shortcomings, such as from a weight standpoint, a shipping standpoint, a lack of aesthetic or acoustical variety, and the like.
Some of these panels are used, for example, in drop ceiling systems wherein a gridwork of inverted T-shaped support members define rectangular openings in which acoustical panels or the like are placed. Such acoustical panels are typically rigid in nature and somewhat brittle. As a result, they are difficult to insert or remove from the supporting gridwork and in many cases are easily damaged during such process. Further, the ceiling panels are relatively heavy and are of a fixed thickness so that their shipping dimensions are the same as their installation dimensions. Due in part to their weight and bulk during shipping, the cost per square foot of such panels is relatively high.
Drywall is also relatively heavy, difficult to work with and has a shipping size identical to that of its installation size. The shipping cost for drywall is, therefore, also relatively high.
It will be appreciated from the above that structural panels used in the construction, finish and decoration of building structures suffer numerous shortcomings. A panel that would overcome such shortcomings would, therefore, be desirable.

Compressible structural panel with end clip


After a via hole (102) to connect a lower wiring (101) and an upper wiring not shown is formed in an insulating film (103) using an etching stopper film (104) and a hard mask (105), a base film (106) made from Ta is formed over the insulating film (103) so as to cover an inner wall of the via hole (102) by a one-step low-power bias sputtering method of the present invention. Thus, the base film (106) with a thin and uniform film thickness covering a region from an inner wall surface of the via hole (102) to the insulating film (103) is obtained. This makes it possible to form the base film thin and uniformly over the inner wall surface, that is, from a sidewall surface to a bottom surface, of the opening without causing any disadvantage in terms of wiring formation by relatively simple steps, thereby realizing a highly reliable ultra-fine wiring structure.

With high integration of a semiconductor element and a reduction in chip size, finer wiring and multilayered wiring are acceleratingly promoted. In a logic device having such a multilayer wiring structure, wiring delay is becoming one of factors governing device signal delay. The device signal delay is proportional to the product of wiring resistance and wiring capacity, and hence, to improve wiring delay, reductions in wiring resistance and wiring capacity are important.
To reduce the wiring resistance, the formation of wiring with Cu which is low-resistance metal as a material is studied. Since it is very difficult to form wiring by patterning Cu, a so-called damascene method in which an opening which becomes a wiring trench or a connection hole (via hole) is formed in an insulating film and filled with Cu to form the wiring is worked out.
When Cu wiring is formed by the damascene method, a step of forming a base film which covers an inner wall of the opening before Cu is deposited is included, mainly in order to prevent Cu from diffusing into the insulating film. Refractory metal such as Ta or W used as a material for the base film is generally high resistant, but in recent years when finer wiring is promoted, it is indispensable to reduce the resistance value of the base film from a matter of wiring resistance. In particular, in the case of an ultra-fine wiring layer containing a via hole with a diameter of 0.1 μm and a wiring with a width of 0.1 μm, it is necessary to thin the base film as much as possible in order to reduce wiring resistance and contact resistance, and hence the technology for forming a base film thin and uniformly over an inner wall of a wiring trench or a via hole is desired.
A CVD method is first thought of as a method for forming such a base film. As far as the formation of the thin and uniform base film is concerned, it is thought that the use of the CVD method is advantageous, but the CVD method has a big problem in compatibility with and adhesiveness to a low dielectric constant insulating material which is expected as a material for the insulating film in which the opening is formed, and the application of this method is difficult in the present circumstances. A sputtering method is superior in the aforementioned compatibility and adhesiveness to the CVD method, whereby the use of the sputtering method for the formation of the base film is considered to be suitable.
At present, as sputtering technology used for forming the base film, there are a long throw sputtering method in which the distance between a substrate and a target is set longer than normal, a bias sputtering method in which a film is formed while a bias voltage is applied to a substrate, a multistep sputtering method in which two or more steps of sputtering as a combination of sputter deposition and sputter etching are performed, and so on.
However, under the present circumstances, even if the aforementioned various sputtering methods are used, the base film cannot be formed thin and uniformly over an inner wall surface, that is, from a side wall surface to a bottom surface, of the wiring trench or the via hole.
Specifically, part of a process of forming wiring containing a base film is shown in FIG. 1A to FIG. 3.
Here, for example, when a via hole 102 to connect a lower wiring 101 and an upper wiring not shown is formed in an interlayer insulating film 103 using an etching stopper film 104 and a hard mask 105, a Ta base film 106 is formed over the interlayer insulating film 103 so as to cover an inner wall of the via hole 102 by a sputtering method, and thereafter Cu 107 is deposited so as to be embedded in the via hole 102 by a plating method. Here, FIG. 1A shows a case where a long throw sputtering method is used as the sputtering method when the base film 106 is formed, FIG. 1B shows a case where a bias sputtering method is used, FIG. 2 shows a case where a multistep sputtering method (1) is used, and FIG. 3 shows a case where a multistep sputtering method (2) is used.
The Case of the Long Throw Sputtering Method
In the example of FIG. 1A, when a semiconductor substrate with a diameter of 200 mm is used, the method is carried out under the condition that the target power is between 10 kW and 20 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 0 W and 300 W. When a semiconductor substrate with a diameter of 300 mm is used, the method is carried out under the condition that the target power is between 20 kW and 40 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 0 W and 500 W.
In this case, Ta is thickly deposited over a bottom portion of the via hole 102 and a portion (field portion) other than the via hole 102 of the interlayer insulating film 103, whereas scarce Ta is deposited over a sidewall surface of the via hole 102, and as a result, due to insufficient coverage of the sidewall surface, poor embedding, for example, a void 108 occurs in the Cu 107 formed by plating.
The Case of the Bias Sputtering Method
In the example of FIG. 1B, when a semiconductor substrate with a diameter of 200 mm is used, the method is carried out under the condition that the target power is between 10 kW and 25 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 300 W and 600 W. When a semiconductor substrate with a diameter of 300 mm is used, the method is carried out under the condition that the target power is between 20 kW and 40 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 500 W and 1200 W.
In this case, excessive Ta is deposited not only over the bottom surface of the via hole 102 but also in the vicinity of a rim portion of the via hole 102 (a so-called overhang is formed). This causes poor embedding, for example, the void 108 on the side wall surface of the via hole 102 and a seam 109 in the vicinity of the entrance of the via hole 102 to the Cu 107.
The Case of the Multistep Sputtering Method (1)
In the example of FIG. 2, when a semiconductor substrate with a diameter of 200 mm is used, in a first step, long throw sputtering is carried out under the condition that the target power is between 10 kW and 25 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 0 W and 300 W, and in a second step, bias sputtering is carried out under the condition that the target power is between 10 kW and 25 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 300 W and 600 W. When a semiconductor substrate with a diameter of 300 mm is used, in a first step, long throw sputtering is carried out under the condition that the target power is between 20 kW and 40 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 0 W and 500 W, and in a second step, bias sputtering is carried out under the condition that the target power is between 20 kW and 40 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 500 W and 1200 W.
In this case, a portion over the bottom surface of the via hole 102 of the base film 106 is formed thick and the embedding property of Cu is relatively good, but an overhang caused by excessive deposition of Ta in the vicinity of the rim portion of the via hole 102 is formed, and thereby the thickness of the base film 106 becomes nonuniform.
The Case of the Multistep Sputtering Method (2)
In the example of FIG. 3, when a semiconductor substrate with a diameter of 200 mm is used, in a first step, long throw sputtering is carried out under the condition that the target power is between 10 kW and 25 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 0 W and 300 W, and in a second step, Ar resputtering is carried out under the condition that the target power is between 0.1 kW and 0.4 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 300 W and 600 W. When a semiconductor substrate with a diameter of 300 mm is used, in a first step, long throw sputtering is carried out under the condition that the target power is between 20 kW and 40 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 0 W and 500 W, and in a second step, Ar resputtering is carried out under the condition that the target power is between 0.1 kW and 0.5 kW, the pressure is 4×10−2 Pa, and the substrate bias power is between 500 W and 1200 W.
As shown by the arrows A, Ta deposited over the bottom surface of the via hole 102 in the first step adheres again to a side surface of the via hole 102 to make up a shortage of Ta over the side surface in the second step, but as shown by the arrow B, if an etching factor is strong, Ta becomes insufficient over the bottom surface of the via hole 102, which brings about a state in which hardly any Ta is deposited over the bottom surface. When positional displacement occurs between the lower wiring 101 and the via hole 102 due to this, for example, Cu deposited by plating diffuses into the interlayer insulating film 103. Furthermore, the seam 109 occurs in the vicinity of the entrance of the via hole 102 because of the formation of the overhang caused by the excessive deposition of Ta in the vicinity of the rim portion of the via hole 102.
The comparison of field portion film thicknesses, sidewall surface coverages, overhangs, via hole bottom surfaces, and embedding properties among the aforementioned long throw sputtering method, bias sputtering method, and multistep sputtering methods (1) and (2) will be shown in the following Table 1.
TABLE 1FieldFilmSidewallViaEmbeddingThicknessCoverageOverhangBottomPropertyLong ThrowThickThinSmallThickSidewallSputteringVoid Tendsto OccurOne-stepThickSlightlySlightlySlightlySeam/SideBiasThinLargeThinWall VoidsputteringOccurMultistepThickSlightlySlightlyThickRelativelysputteringThickLargeGood(1)EmbeddingMultistepThinThickLargeAlmostSeam TendsSputteringNothingto Occur(2)
Even if the various sputtering methods are used as just described, it is very difficult to form the basic film with a uniform film thickness in the opening. There is also a disadvantage that to control the film forming state of the base film, the multistep method with three or more steps needs to be adopted, which causes complication of a film forming process thereof, resulting in an increase in the time required for the process. This causes an increase in target power consumption, an increase in particles produced at the time of film formation, and a deterioration in throughput, which leads to a considerably thick deposition over the field portion while the necessary amount of film is formed in the opening. The base film deposited over the field portion needs to be removed by polishing in a chemical mechanical polishing (CMP) process, but the base film too thick leads to a deterioration in throughput in the CMP process and furthermore exerts a bad influence on the capability of the entire manufacturing line. Moreover, CMP of the base film has mechanical polishing as a strong factor, and hence flaws such as scratches tend to occur, which may contribute to a reduction in the yield of wiring formation.
(Patent Document 1)
Japanese Patent Application No. 2002-318674

Wiring structure forming method and semiconductor device


An escalator with a high speed inclined section, includes link mechanisms, each of which has a first link with a first end rotatably connected to a step link roller shaft, and a second link, a first end of which is rotatably connected to a middle portion of the first link and a second end of which is rotatably connected to a step link roller shaft of an adjacent step. A rotatable auxiliary roller is located at a second end of the first link.

1. Field of the Invention
This invention relates to an escalator with a high speed inclined section in which the steps move faster in the intermediate inclined section than in the upper and lower landing sections.
2. Description of the Related Art
Nowadays, a large number of escalators of great height are installed in subway stations or the like. In an escalator of this type, the passenger is obliged to stand on a step for a long period of time, which is often rather uncomfortable. In view of this, a high-speed escalator has been developed. However, in such a high-speed escalator, there is a limitation regarding the traveling speed from the viewpoint of allowing the passengers to get off and on safely.
In view of this, there has been proposed an escalator with a high speed inclined section in which the steps move faster in the intermediate inclined section than in the upper and lower landing sections, whereby it is possible to shorten the traveling time for the passenger. An example of an escalator with a high speed inclined section is disclosed in Japanese Patent Application Laid-Open No. Sho 51-116586.
FIG. 5 is a schematic side view of an example of a conventional escalator with a high speed inclined section. In the drawing, a main frame 1 is provided with a plurality of steps 2 connected together in an endless fashion. The steps 2 are driven by a drive unit 3 to be circulated. The main frame 1 is provided with a pair of main tracks 4 forming a loop track for the steps 2, a pair of trailing tracks 5 for controlling the attitude of the steps 2, and a pair of auxiliary tracks 6 for varying the gap between adjacent steps 2.
The loop track for the steps 2 formed by the main tracks 4 have a forward track section, a return track section, an upper reversing section F, and a lower reversing section I. The forward track section of the loop track includes a horizontal upper landing section (upper horizontal section) A, an upper curved section B, an intermediate inclined section (fixed inclination section) C of a fixed inclination angle, a lower curved section D, a horizontal lower landing section (lower horizontal section) E, an upper transition section G, and a lower transition section H.
The intermediate inclined section C is situated between the upper landing section A and the lower landing section E. The upper curved section B is situated between the upper landing section A and the intermediate inclined section C. The lower curved section D is situated between the lower landing section E and the intermediate inclined section C. The upper transition section G is situated between the upper landing section A and the upper reversing section F. The lower transition section H is situated between the lower landing section E and the lower reversing section I.
Above the steps 2 of the upper and lower landing sections A and E, there are arranged a pair of landing plates 22a and 22b. The landing plates 22a and 22b are arranged in the floor portions of the upper and lower landing sections A and E so as to cover the steps 2. Arranged upright above the main frame 1 are a pair of moving handrail devices 23. The moving handrail devices 23 are arranged on either side of the steps 2 with respect to the width direction thereof.
FIG. 6 is a side view showing the portion around the upper landing section A of FIG. 5. Each step 2 has a tread 7 for carrying a passenger, a riser 8 formed by bending the lower end portion of the tread 7, a step link roller shaft 9, a pair of step link rollers 10 rotatable around the step link roller shaft 9, a trailing roller shaft 11, and a pair of trailing rollers 12 rotatable around the trailing roller shaft 11. The step link rollers 10 roll on the main tracks 4. The trailing rollers 12 roll on the trailing tracks 5.
The step link roller shafts 9 of adjacent steps 2 are connected to each other by a pair of link mechanisms (bending links) 13. Each link mechanism 13 has first through fifth links 14 through 18.
One end portion of the first link 14 is rotatably connected to the step link roller shaft 9. The other end portion of the first link 14 is rotatably connected to the middle portion of the third link 16 through a shaft 19. One end portion of the second link 15 is rotatably connected to the step link roller shaft 9 of the adjacent step 2. The other end portion of the second link 15 is rotatably connected to the middle portion of the third link 16 through the shaft 19.
One end portion of the fourth link 17 is rotatably connected to the middle portion of the first link 14. One end portion of the fifth link 18 is rotatably connected to the middle portion of the second link 15. The other end portions of the fourth and fifth links 17 and 18 are connected to one end portion of the third link 16 through a slide shaft 20.
Provided in one end portion of the third link 16 is a guide groove 16a for guiding the sliding of the slide shaft 20 in the longitudinal direction of the third link 16. Provided at the other end of the third link 16 is a rotatable auxiliary roller 21. The auxiliary roller 21 is guided by the auxiliary track 6.
When the auxiliary roller 21 is guided by the auxiliary track 6, the shape of the link mechanism 13 is changed and extends and retracts, and the distance between the step link roller shafts 9, that is, the distance between the adjacent steps 2, is varied. In other words, the line of the auxiliary track 6 is designed so that the distance between the adjacent steps 2 varies.
Next, the operation of this conventional escalator will be described. The speed of the steps 2 is varied by varying the distance between the step link roller shafts 9 of the adjacent steps 2. That is, the distance between the step link roller shafts 9 is larger in the intermediate inclined section C than in the upper and lower landing sections A and E where passengers get on or off, whereby the steps 2 move faster in the intermediate inclined section C than in the upper and lower landing sections A and E.
The first, second, fourth, and fifth links 14, 15, 17, and 18 form a so-called pantograph type quadruple link mechanism, and the angle made by the first and second links 14 and 15, with the third link 16 being an axis of symmetry, can be increased or decreased, whereby it is possible to vary the distance between the step link roller shafts 9 connected to the first and second links 14 and 15.
That is, when the distance between the main track 4 and the auxiliary track 6 is diminished, the link mechanism 13 operates like the framework of an umbrella when it is opened, and the distance between the step link roller shafts 9 of the adjacent steps 2 increases.
In the intermediate inclined section C shown in FIG. 5, the distance between the main track 4 and the auxiliary track 6 is minimum, and the distance between the step link roller shafts 9 of the adjacent steps 2 is maximum. Thus, the speed of the steps 2 is maximum. In this condition, the first and second links 14 and 15 are arranged substantially in a straight line.
Further, in the escalator with a high speed inclined section in which the distance between the steps 2 increases in the intermediate inclined section C, the riser 8 downwardly protrudes so as to fill the opening between the adjacent treads 7. When reversing the steps 2 having the risers 8 of this configuration in the reversing sections F and I, the steps 2 will interfere with each other, unless the distance between the steps 2 is increased. Thus, in the reversing sections F and I, the distance between the steps 2 is increased. Accordingly, in the transition sections G and H, an operation to expand the link mechanism 13 is conducted.
However, in the conventional escalator with a high speed inclined section constructed as described above, it is necessary to provide a large number of bearing portions in the link mechanism 13, and the influence of play due to production errors, wear, etc. of the bearing portions is great, so that there is a danger of the distance between the step link roller shafts 9 becoming too large or, conversely, the adjacent steps 2 interfering with each other.
Further, in the conventional escalator with a high speed inclined section, when the operation to expand the link mechanism 13 is conducted in the transition sections G and H, the third link 16 protrudes beyond the height of the landing plates 22a and 22b. Thus, in an area where the moving handrail device 23 is directly above the link mechanism 13, it is impossible to perform the operation to expand the link mechanism 13. Thus, as shown, for example, in FIG. 7, the distance between the steps 2 starts to increase at a position well on the inner side rather than at an end portion 22c of the landing plate 22a and 22b. As a result, the length of the upper landing section A and that of the lower landing section E become rather large, so that the size of the escalator is rather large.
Further, in the conventional escalator with a high speed inclined section, the auxiliary track 6 exhibits a smooth arcuate configuration in the upper curved section B and the lower curved section D. Thus, the change in the difference in height between the adjacent steps 2 is not completed in the upper curved section B and the lower curved section D, and the change in the difference in height continues in the upper landing section A, the lower landing section E, or the intermediate inclined section C. Thus, as shown, for example, in FIG. 8, the sectional configuration of the riser 8 is discontinuous and bent in the direction of inclination of the intermediate inclined section C; it cannot be formed in a continuous plane or curve, resulting in an increase in production costs.

Escalator with high speed inclined section


Electrode elements directly heat water and with an electric current controller that is controlled by the heated water volume, which structurally enables immediate production of high temperature steam. The innovations of the invention here include: the utilization of an electric current controller than can be set at a certain value so that an electromagnetic water input valve is switched on or off at an appropriate time, which permits the maintaining of a fixed volume of water inside the water container and as such, the water inside the water container is not only prevented from overflowing, but at the same time forms an electric field with the electrode elements and is subsequently directly heated and thereby enables the production of high temperature steam in an extremely short period of time. Furthermore, the steam output port is designed with a pressure relief valve and a flow adjustment valve such that the high temperature steam produced rapidly escapes or is released in large volume safely and stably, which effectively ensures greater ease, convenience, multifunctionality and safety.

The use of steam is extremely widespread and commonplace, with examples including power generation, cooking, ironing clothes, humidity adjustment and even medical treatment, therapeutics (such as steam baths) and so on. As for the conventional methods of supplying steam, the majority rely on a combustible fuel (such as wood, coal, gasoline and natural gas, etc.) or electrical heating, whereby water is first heated. However, regardless of whether a fuel or electrical means of heating water are employed, and although the heat source is in close proximity to the liquid being heated, the heat must travel through a medium (such as a water container or metal heating tubes), which is essentially indirect heating. Therefore, in addition to the shortcomings of poor heating efficiency and the wasting of energy resources, a certain amount of preheating time is required before the water being heated reaches a high temperature and it is therefore virtually impossible to produce steam in a predictable short period of time. In terms of practical usage, such approaches have disadvantages such as wasted time, inconvenience and low efficiency. Furthermore, when a user fails to notice that all the water in the water container has evaporated, and the fuel or electrical power source continues to provide heat, the drawback is not only a waste of energy, but the aforesaid water container, heating tubes and other heating components become damaged or a hazardous situation may result.

Electrode-type steam production device with automatically controlled water inlet and outlet valves


A laser radar system according to the present invention includes: a light source to output light having a first frequency in a first period and light having a second frequency in a second period; an optical splitter to split the lights, outputted from the light source, into signal light and local oscillator light; an optical modulator to modulate the signal light into pulsed light; an optical antenna to output the pulsed light into space and to receive, as reception light, the scattered light from a target; an optical heterodyne receiver to perform heterodyne detection on the reception light by using the local oscillator light; and a measurement unit to measure the distance to the target or the movement characteristics of the target by using the reception signal detected by the optical heterodyne receiver, wherein the optical heterodyne receiver performs the heterodyne detection on the first frequency of the reception light by using the second frequency of the local oscillator light. With this configuration, a large amount of frequency shift can be provided between the signal light and the local oscillator light, and thus, the distance to the target can be measured with high resolution by using short pulsed-light.

In a laser radar system which sends and receives laser light to and from a target for measuring the distance to the target, a direct detection method in which an intensity-modulated signal is received or a heterodyne detection method capable of receiving a signal with high sensitivity has been used.
In the conventional direct detection method, there has been a problem in that the thermal noise is dominant and it degrades the reception sensitivity. In a configuration in which heterodyne detection on pulsed light is performed for high-sensitivity reception (for example, Patent Document 1), a modulator is required to shift a frequency of transmission light or local oscillator light, bringing difficulties in downsizing or integration. Also, there is a disclosure of a laser radar system which performs heterodyne detection using intensity-modulated signal light (for example, Patent Document 2). In the disclosed technology, the frequency of the intensity-modulated signal is equivalent to Doppler frequency; therefore, it is difficult to apply the technology to pulsed light.
In a laser radar system of a pulse type, the pulse width of the pulse signals determines the resolution of the distance measurement. In order to perform heterodyne detection on the pulse signals, a frequency difference between the signal light and the local oscillator light has to be provided so as to be able to cope with the pulse signals.


A system and method for making and using a reconfigurable composite part mandrel operable in the manufacture of composite parts. The system may comprise an assembly fixture, a generic mandrel, a reconfigurable simulated skin, a reconfigurable frame portion, and state-changing material operable to harden into a desired configuration for forming a particular composite part. The method of forming and using the reconfigurable composite part mandrel may comprise: inserting the simulated skin within the assembly fixture, inserting or assembling the frame portion within the assembly fixture; inserting the generic mandrel into the assembly fixture; filling a cavity between the generic mandrel and the assembly fixture with the state-changing mixture to encapsulate the frame portion; hardening the state-changing mixture; and removing the assembly fixture and the simulated skin.

1. Field
The present invention relates to a system and method for manufacturing composite parts using a reconfigurable fuselage mandrel. More particularly, the present invention relates to a system having an assembly fixture, a generic mandrel, a reconfigurable simulated skin, a reconfigurable frame portion, and state-changing material operable to harden into a desired configuration for forming a particular composite part.
2. Related Art
In the manufacturing of composite parts, such as those used in aircrafts, permanent tooling is generally used to create the proper templates or molds to form the composite parts of a given size, shape, and configuration. The permanent tooling can be costly and time-consuming to make and especially to modify.
One type of permanent tooling used in the fabrication of composite parts is a mandrel. Most mandrels are machined from solid pieces of material such as aluminum or cast into a fixed shape and cannot be easily reconfigured. For example, in the manufacturing of an aircraft fuselage, a frame portion may be locked into a particular configuration as dictated by the permanent tooling. Therefore, if another frame configuration is desired, a different permanent tool has to be made.
Accordingly, there is a need for an improved system and method for forming reconfigurable and inexpensive tooling for the manufacture of composite parts that overcomes the limitations of the prior art.


A dual unit to gently and user adjustably support a user's head from slumping either too much forward or too much to either side while allowing proper air circulation for user comfort when the user is in an upright position with the unit releaseably held to a chair back is disclosed.

There is a large amount of prior art indicating the perceived need for a properly designed portable support pillow for one to sleep in an upright position while traveling and, particularly with asthma sufferers while at home. It is known in the Medical profession that sound healthful sleep in the upright position requires comfortable support of the head and neck to prevent undue lateral or forward or backward flexure. Since coach class airline seats only recline about four inches prevention of undue forward flexure is a necessity in a properly designed portable travel pillow. To allow for user comfort in use side support for a user's head should allow for air circulation around the ears and neck and minimize perspiration of the head. The pillow should have a washable covering, be adaptable to fit many different styles of airline, bus, train, or auto seats as well as to fit many living room chairs and should be foldable to a relatively small package for easy portability.
The subject invention fulfills all these needs. We find no prior art to fulfill all these needs.


A stator includes a plurality of stator elements, each stator element comprising a c-shaped core having two poles. Each pole of each stator element is secured to a pole of an adjacent stator element by a bridge formed of a non-magnetic material molded onto the poles.

The stator of a four-pole electrical machine may comprise two c-shaped cores arranged on opposite sides of the rotor. In employing c-shaped cores, a relatively high fill-factor may be achieved for the stator. Additionally, winding the coils onto the cores is generally easier in comparison to that for a single-piece core.
The air gap between the rotor and the stator is ideally as small as possible so as to reduce reluctance. On the other hand, the air gap must be sufficiently large such that, at the tolerance limit, the rotor is free to rotate without contacting the stator. Tolerances in the alignment of the two stator cores generally mean that a larger air gap is required in comparison to a single-piece core.