The invention relates to a process for the preparation of pigment granules, which comprises adding a wax or a waxy polymer to an organic pigment during the finish in an organic or aqueous organic medium and spray-drying the aqueous suspension obtained after removal of the organic solvent by steam distillation or washing out with water.

The invention relates to a process for the preparation of an organic colorant composition in granular form, comprising wax-coated organic pigments.
When prepared, organic pigments are generally obtained in the form of powders. Powders comprise very small particles and therefore give rise to a great deal of dust. Dust development leads to the contamination of apparatuses, plants and products, so that expensive and time-consuming cleaning work has to be carried out especially when changing products. Consequently, the pigment processors require the provision of pigment forms which do not produce dust.
For use, pigments must be dispersed in the application medium. If the pigments are present as powder, the dispersing is generally effected with the introduction of a considerable amount of energy, for example for the use of twin-screw extruders in the coloring of plastics. Pigments which are present in a predispersed form are therefore advantageous for the application.
JP 10-251533 describes quinacridone pigments which are brought into a predispersed form by wax coating via an isobutanol finish. The wax-coated quinacridone pigments, which have a particle size of from about 0.05 to 0.3 xcexcm, are used in the form of a powder and thus have the disadvantage of developing dust.
DE-A1-29 40 156 and WO 92/07912 describe processes for the preparation of low-dust, free-flowing pigment granules by using a fluidized-bed method. Blowing air through the pigment powder produces a fluidized bed or fluidized pigment powder, which is sprayed with an aqueous solution, dispersion or emulsion of a granulating assistant.
In another process (DE 39 35 815 C2), the pigment is sprayed with a wax dispersion in a mixer-granulator. These processes have the disadvantage that the pigment is not present in a predispersed form advantageous for subsequent use, since the surface of the pigment particles is only incompletely coated with the wax or the assistant. In addition, it is not possible to fluidize every powder pigment to give a fluidized bed (Powder Technology 57, 127-133 (1989)), so that this method cannot be generally used.
Said processes have the disadvantage that either a predispersed but dust-producing pigment powder (JP 10-251 533) or pigment granules which do not produce dust but are not sufficiently predispersed are prepared. Moreover, the known processes for the preparation of a pigment form which does not produce dust start from prepared pigment powder and therefore give rise to additional operations, which increase the cost.
It is the object of the present invention to provide a process for the preparation of dustless, flowable and readily dispersible organic pigments, which requires no additional process steps compared with the preparation of the corresponding pigment powder.
It has been found that the disadvantages mentioned in the prior art are surprisingly overcome by spray-drying organic pigments which have been coated with a wax or polymer layer during a finish process to be carried out in the pigment preparation.
The present invention relates to a process for the preparation of readily dispersible pigment granules, which comprises adding a wax or waxy polymer to an organic pigment during the finish process in an organic or aqueous organic medium, removing the organic solvent of said organic or aqueous organic medium and spraydrying an aqueous suspension of the pigment. Said aqueous suspension may be obtained by steam distillation or washing out with water.
During the finish process, the pigment particles are brought into intimate contact with the wax or waxy polymer. After removal of the solvent by steam distillation, a sprayable aqueous solution is obtained. Nevertheless, it may be expedient to filter the suspension prior to the spray-drying and to remove any salts present by washing and to stir the press cake obtained by the filtration again to give a sprayable suspension. In an expedient procedure for washing out with water, the solid is filtered off and is washed solvent-free with water, and the press cake obtained thereby is diluted with water to give a sprayable suspension.
As a result of the spray-drying, on the one hand, granulation to a suitable particle size is achieved without the coating of the pigment particles with the wax or polymer, achieved during the solvent finish, being damaged. On the other hand, the drying and milling required in the preparation of pigment powders are avoided.
The pigment granules according to the invention have a mean particle diameter of from 0.05 to 5 mm. Granules having particle diameters in the range from 0.1 to 2 mm are particularly preferred. Owing to their generally spherical shape, the granules are flowable and hence readily meterable. Because of their size and weight, the granules produce very little dust.
Suitable organic pigments are, for example, azo pigments, such as monoazo, disazo, naphthol and metal complex pigments, as well as polycyclic pigments, such as isoindolinone and isoindoline pigments, anthanthrone, thioindigo, quinophthalone, anthraquinone, dioxazine, phthalocyanine, quinacridone, perylene, perinone, diketopyrrolopyrrole and azomethine pigments.
Waxes do not have a standard chemical definition and form a group of substances with identical or similar application properties, characterized by particular physical properties. Thus, the term xe2x80x9cwaxxe2x80x9d designates a number of natural or synthetically obtained substances which as a rule have the following properties: kneadable at 20xc2x0 C., solid to brittly hard, coarse to finely crystalline, translucent to opaque, but not glassy; melting without decomposition above 40xc2x0 C., relatively low viscosity and nonthread-drawing slightly above the melting point, highly temperature-dependent consistency and solubility, polishable under slight pressure (cf. Ullmanns Encyklopxc3xa4tdie der technischen Chemie [Ullmann""s Encyclopedia of Industrial Chemistry], Volume 24, 4th Edition, 1983, pages 1-49, Verlag Chemie, Weinheim and Rxc3x6mpps Chemie-Lexikon [Rxc3x6mpp""s Chemistry Lexicon], Volume 6, 8th Edition, 1988, page 463, Franck""sche Verlagshandlung).
Preferred waxes are: natural waxes, such as vegetable waxes, e.g. carnauba wax and candellila wax, and animal waxes, e.g. beeswax, modified natural waxes, such as, for example, paraffin waxes, microwaxes, semisynthetic waxes, such as, for example, montan ester waxes, or fully synthetic waxes, such as polyolefin waxes, e.g. polyethylene and polypropylene waxes, polyethylene glycol waxes, cycloolefin copolymer waxes, amide waxes, such as, for example, N,Nxe2x80x2-distearylethylenediamine, and chlorine- or fluorine-containing polyolefin waxes or polyethylene-polytetrafluoroethylene wax mixtures.
Polyolefin waxes and polyolefin waxes containing polar groups and formed by subsequent oxidation of the polyolefin wax, by a graft reaction with monomers containing carboxyl, carboxylic ester, carboxylic anhydride or hydroxyl groups or by copolymerization of an olefin and a monomer containing carboxyl, carboxylic ester, carboxylic anhydride or hydroxyl groups, are particularly preferred.
Suitable polymers are relatively high molecular weight compounds which have a waxy character and were preferably prepared by polycondensation or polyaddition processes, for example thermoplastic polyester, epoxide, styrene/acrylate copolymer, styrene/butadiene copolymer and cycloolefin copolymer resins, such as, for example, (copyright)Topas.
In order to have sufficient solubility at elevated temperature in organic solvents, the polymers generally have a number average molecular weight ({overscore (M)}n) of up to 20,000. Waxes having a number average molecular weight ({overscore (M)}n) of up to 10,000 are preferred, those having a number average molecular weight ({overscore (M)}n) of up to 5000 being particularly preferred. The drop point of the waxes used according to the invention or the softening temperature of the polymers is preferably in the range from 60 to 180xc2x0 C., particularly preferably in the range from 80 to 140xc2x0 C.
The amount and the type of the wax or polymer may vary depending on the field of use of the pigment granules, in particular to ensure compatibility with the application medium. In order to produce a defined property profile, it is also possible to use a mixture of at least two different waxes or polymers.
Expediently, the organic pigment is used in an amount of from 50 to 99% by weight, preferably from 60 to 95% by weight, and the wax or polymer in an amount of from 1 to 50% by weight, preferably from 5 to 40% by weight, based on the total weight of the pigment granules.
A person skilled in the art understands the term finish process as meaning an aftertreatment of the crude pigment formed in the synthesis, generally in the form of a water-moist press cake, of an aqueous pigment suspension or of a dry pigment, in a finish medium, for example in an organic solvent or a mixture of water and organic solvent, in order to produce a crystal form and/or crystal modification advantageous for the subsequent use. Expediently, a 2 to 30% strength by weight suspension of the crude pigment or crude pigment press cake in the finish medium is stirred, kneaded and/or refluxed, optionally with heating, with the addition of the wax or polymer.
The finish medium chosen is preferably that organic solvent or that mixture of water and inorganic solvent which partially or completely dissolves the wax or polymer used at the finish temperature and can be removed by steam distillation or washing out. Preferred solvents are aliphatic alcohols, such as, for example, n-butanol, isobutanol, n-octanol, isooctanol; aromatic hydrocarbons, such as, for example, benzene, toluene, xylene, cresol, chlorobenzene, 1,2-dichlorobenzene; esters, such as, for example, ethyl acetate, butyl acetate; ketones, such as, for example, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone; dipolar aprotic solvents, such as, for example, N-methylpyrrolidone, dimethyl sulfoxide or sulfolane. The finish temperatures may be, for example, in the range from 20 to 200xc2x0 C., preferably from 60 to 180xc2x0 C. The finish process expediently takes from 1 to 24 hours, preferably from 2 to 10 hours. It may be advantageous to carry out the finish process by a procedure in which first, for example, heating is effected for 1-10 hours to 60 to 200xc2x0 C., cooling is then effected to 100 to 20xc2x0 C. and the wax or polymer is added, and heating is then effected again to 60 to 200xc2x0 C. It is also possible to add the wax or polymer directly to the finish batch during the finish process, i.e. without intermediate cooling.
In the finish process, the usually lipophilic pigment is coated with the organic phase (solvent and wax/polymer). This procedure has the advantage that the pigment is present in finely divided form in the organic phase. Final covering of the pigment surface with wax/polymer is achieved by the removal of the solvent, which is done by steam distillation (temperature e.g. from 80 to 100xc2x0 C.) or by washing out with water on a filter, expediently at from 20 to 95xc2x0 C. An aqueous suspension of pigments coated with wax/polymer is then present. The suspension is, if required, adjusted to the desired concentration with water, expediently to a 5 to 30% strength by weight suspension of the pigment coated with wax/polymer, if required homogenized with the aid of a colloid mill or of a comparable unit and then spray-dried to give granules.
In some cases, the addition of a surfactant may be advantageous for optimum wetting of the pigment surface with the wax/polymer. Suitable surfactants are cationic surfactants, such as, for example, quaternary ammonium salts, long-chain alkylamines (in the neutral to slightly acidic pH range); anionic surfactants, such as, for example, carboxylic acids, sulfonic acids, sulfonic esters, such as, for example, sulfosuccinic esters, and salts thereof; amphoteric surfactants, such as, for example, betaines, and nonionic surfactants, such as, for example, sugar alkylates and acylates, ethoxylated sugar alkylates and acylates, glyceryl esters, polyethylene glycol esters, and ethoxylated fatty acids, fatty alcohol ethoxylates and fatty amine ethoxylates. The surfactant can be added before the finish or during the finish process.
Spray towers having an airless high-pressure nozzle or spray towers which carry out pelletizing (e.g. fluidized-bed spray-dryer) are suitable for the spray-drying. In the case of spray towers having an airless high-pressure nozzle, the suspension is sprayed in the form of relatively large drops and the water is evaporated. If the temperatures in the spray towers are above the drop point of the wax/polymer, the wax/polymer melts and levels to spherical granules having a smooth surface.
In the case of FSD spray towers, the suspension is sprayed to give a fine powder. The vigorous fluidization in the fluidized bed and the recirculation of the fine powder particles entrained by the exit air and deposited in an upstream cyclone ensure that the spray-drying takes place in a turbulent powder cloud. This gives rise to a dusting effect and, at tower temperatures above the drop point of the wax/polymer, the particles stick together to give raspberry-like granules. The residual moisture and the granulometry are controlled in the fluidized bed.
The gas inlet temperature in the spray tower is usually in the range from 180 to 300xc2x0 C., preferably from 190 to 280xc2x0 C., and the gas outlet temperature is in the range from 70 to 150xc2x0 C., preferably from 90 to 130xc2x0 C.
The granules can be used for coloring high molecular weight organic materials. These may be of natural or synthetic origin. They may be, for example, natural resins, drying oils or rubber. However, they may also be modified natural substances, such as, for example, chlorine rubber, cellulose derivatives, such as cellulose esters or cellulose ethers, and in particular fully synthetic organic polymers (plastics) which are prepared by polymerization, polycondensation or polyaddition. From the class consisting of the plastics prepared by polymerization, the following may be mentioned in particular: polyolefins, such as, for example, polyethylene, polyproylene, polyisobutylene, and substituted polyolefins, such as, for example, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetals, polyacrylonitrile, polyacrylic acid, polymethacrylic acid, polyacrylic esters and polymethacrylic esters or polybutadiene, and copolymers thereof. From the class consisting of the plastics prepared by polyaddition and polycondensation, the following may be mentioned: polyesters, polyamides, polyimides, polycarbonates, polyurethanes, polyethers, polyacetals, and the condensates of formaldehyde with phenols (phenoplast) and the condensates of formaldehyde with urea, thiourea and melamine (aminoplasts).
Said high molecular weight organic material may be present individually or as mixtures in the form of plastics materials or melts. It may also be present in the form of its monomers, which are polymerized after coloring.
The pigment granules according to the invention can be used in any ratio which is required for coloring the high molecular weight organic material, usually in amounts from 0.1 to 30% by weight, preferably from 1 to 20% by weight, based on the total weight of the pigmented high molecular weight organic material.
For coloring the high molecular weight organic material, the granules according to the invention may be used alone. For establishing different hues or color effects, it is also possible to add other colorants, such as, for example, white, colored or black pigments, and effect pigments to the high molecular weight organic material, in addition to the granules according to the invention.
The granules are highly concentrated colorants in which the pigments are present in a predispersed form, similar to a masterbatch. No major dispersing work need therefore be performed for coloring the high molecular weight organic material and, for example, thorough mixing of the granules according to the invention with the high molecular weight organic material in roll mills, mixers, other milling units or a singlescrew extruder is sufficient.

Process for the preparation of pigment granules


An articulating joint comprising a multi-cluster joint where every consecutive pair of links is interfaced by a gimbal, which offers rotation about two orthogonal axes within the same plane. Thus, the articulating joint comprises an alternating sequence of links and gimbals. Furthermore, there may be multiple cables attached to one or more of the links. As these cables are selectively pulled and released, one can achieve any desired articulation of the articulating joint. There may be a transmission member extending through the links and gimbals, parallel to the central longitudinal axis of the joint in its nominal non-articulated condition. This transmission member may be either a tension member that is pulled on (e.g. a cable or flexible pull rod) and that loads the articulating joint in compression, or the transmission member may be a flexible push rod that loads the articulating joint in tension.

A variety of articulating remote access tools (U.S. Pat. Nos. 5,330,502, 8,029,531 B2, U.S. application Ser. No. 13/865,790) have output articulation joints that include one or more of links, multi-links, or clusters which can be controlled by one or more tension members (e.g. articulation cables or articulation transmission cables). These particular combinations of links, clusters, components and tension members can be useful for the purpose of steering an end-effector (EE) for remote access and manipulation of an instrument, specifically a laparoscopic or endoscopic surgical instrument. Since these devices utilize articulating end-effector joints that are generally controlled by tension members (e.g. articulation cables), these devices can be articulated or manipulated via an articulation input generally present in the proximal region of the tool. For example, articulation or manipulation of an articulation input (performed manually or electromechanically) that is coupled with tension members/articulation transmission cables may lead to articulation of the end-effector via an output articulation joint/multi-link end-effector joint (U.S. Pat. No. 8,668,702). The end-effector may include many different embodiments and may not be limited to a pair of jaws. Other embodiments may be useful for holding and manipulation of needles, suture, tissue, cautery, ligation clip application, etc., or it may function in the form of a camera for steerable laparoscopic/endoscopic visualization and/or diagnostics. For any of these uses or other embodiments, articulating mechanisms can provide necessary degrees of freedom to help steer these end-effectors. As used herein, the terms "joint" and "mechanism" may be used equivalently. For minimally invasive surgical tools and procedures, and in particular laparoscopic and endoscopic procedures, an end-effector having an articulation joint may be necessary to provide highly dexterous and wrist-like motions similar to those of a surgeon's own wrist, but in a miniature size. This enhanced dexterity enables complex laparoscopic tasks, including needle driving along the curve of a suturing needle through various tissue planes, tissue dissection and retraction, knot tying, etc. In general, end-effector articulation joints may be positioned between an elongate member such as an instrument/tool shaft that provides the remote access, and an end-effector that provides some functionality such as holding, grasping, dissecting, shearing etc. In order to accomplish the tasks listed above, the end-effector articulation joint must offer certain rotational degrees of freedom (DoF) to the end-effector with respect to the instrument shaft. See, e.g., FIGS. 1A and 1B. These DoF include two orthogonal rotations, generally referred to as the pitch and yaw rotations. In some instances, the roll rotation is constrained by the end-effector articulation joint.
Typically, the articulation joint is controlled by a plurality of tension members, such as wires or cables (e.g. flexible steel or Nitinol wire, steel cable, etc.), which traverse through or make attachments to specific links within a multi-link end-effector articulation joint or route through a complex series of pulleys and various components of the articulation joint to the end-effector. These tensile members are used for articulation of the multi-link articulation joint and in general, may be referred as end-effector articulation transmission cable(s), or as end-effector articulation cable(s) or as articulation cables, or the like. These types of systems have been demonstrated in various embodiments but typically suffer from performance tradeoffs that occur within cable-based actuation of end-effector articulation joints. Cable driven end-effector articulation joints for minimally invasive surgical tools are most practical due to the size constraints imposed on these instrument types due to increasingly smaller access port diameters driven by the desire for reduced patient trauma during surgery resulting in better post-surgery recovery. However, a number of practical tradeoffs plague cable-based articulation mechanisms. End-effector articulation joints for various laparoscopic surgeries may need to provide a large angular range of rotation in all rotational directions (especially, pitch and yaw rotational directions) to the end-effector to provide adequate reach and work space. Once the end-effector has rotated in one direction, in many articulation joints the transmission path for articulating in the other direction may be altered. This may also be associated with an increment of tension in one or more cables that help in articulating multi-link articulation joints and reduction in tension or generation of slack in the opposite cable(s). This may lead to unnecessary slack generation and/or backlash in the end-effector articulation. Various other challenges in design of the articulation joints arise from the performance attributes that have to be met and the associated conflicting tradeoffs that arise from an engineering and design stand-point, as discussed below. Existing solutions have typically required a complex sequence of multiple pulleys and other components, resulting in a design that is not conducive to miniaturization (See, e.g., U.S. Pat. Nos. 8,540,748, 7,101,363, and 8,528,440). Other exemplary devices include US 2010/0030018, Peirs, et. al. (Peirs, J., Brussel, H., Reynaerts, D., Gersem, G., 2002, "A Flexible Distal Tip with Two Degrees of Freedom for Enhanced Dexterity in Endoscopic Robot Surgery", MME'02, The 13th Micromechanics Europe Workshop, Sinaia, Romania) and Simaan et al. (Simaan, N., Tayloer, R., Flint, P., 2004, "A Dexterous System for Laryngeal Surgery", Proceedings of the 2004 IEEE International Conference on Robotics & Automation, New Orleans, La.).
In a typical multi-link articulation joints, multiple links are joined together by two (or more) "articulation cables" per end-effector rotation and pass through holes (also referred to as articulation cable openings) on the periphery of the multiple links. See, e.g., FIGS. 2A and 2B). To achieve the desired large range of rotation, this design has to include multiple links. See, e.g., FIG. 3. The higher the number of links, the greater is the problem of cable slack and end-effector backlash. Further, a larger number of links in conjunction with a large jaw closure force (applied via high tension in end-effector actuation transmission cable) produces jumpiness or jerkiness at the end-effector as well as joint distortion (or S bending) due to a buckling-type phenomenon, described and illustrated below.
Large holding stiffness of the end-effector articulation joint and minimal backlash while holding an articulated orientation are typically necessary for precise control during use. In other words, once the input holds articulation cables "fixed" in a certain actuation (see FIG. 2A), the end-effector should also maintain a corresponding "fixed" articulated orientation. This provides the ability to push the end-effector against its surroundings, and also helps transmit force feedback from the distal tip of the tool back to the proximal aspect, sometimes through an input joint to a user's hand. However, in the multi-link end-effector design, the kinematics of deformation and compliance of the articulation cables is such that, for example, when the distal end link of the end-effector is articulated with respect to the base link of end-effector in one direction of rotation by tensioning an articulation cable or plurality of cables, slack gets developed on the opposed side cable 201 or plurality of cables (see FIG. 2B), and vice versa. Additional slack may arise due to cable stretch, wear, and assembly tolerances. This slack may lead to end-effector backlash and a loss in holding stiffness, as described, for example in international application PCT/US2016/025926 Apr. 4, 2016, titled "TENSION MANAGEMENT APPARATUS FOR CABLE-DRIVEN TRANSMISSION" and filed on Apr. 4, 2016, herein incorporated by reference in its entirety.
Typically, in applications (especially minimal invasive surgery tools) pertaining to holding an object in the end-effector and pushing/pulling it against or piercing it through the surroundings (e.g. holding and driving a needle through tissue), the grasping force applied by end-effector jaws should be high, especially when holding an object such as needle to prevent slipping or rotating in place. This can be achieved via a high tension in the end-effector actuation transmission cable (e.g. the jaw closure cable) that connects an input control at the input to the end-effector jaws. In general, end-effector actuation transmission cable may also be referred to as end-effector actuation cable, or as actuation cable, or as jaw closure cable, or end effector transmission cable or the like. However, when this cable is routed through the multi-link end-effector joint (as is desirable for low-diameter devices), the large tension in this cable produces a buckling type loading effect on the multi-link end-effector. This can potentially result in jerkiness of the end-effector during rotations (pitch, yaw and/or roll). This can also lead to joint distortion (S-bending), which is a consequence of the redundant local degrees of freedom associated with the multiple links of the articulation joint. Previous attempts to address this issue typically use multiple drive pulleys and cables per end-effector rotation direction, which adds considerably to the complexity, size, and cost of the overall tool design, defeating the goal of a creating a simple, low-cost, highly functional minimally invasive surgery (MIS) tool. Thus, there is a tradeoff between using a large number of end-effector links (to provide large range of rotational motion) versus using fewer links (to reduce the operational workspace volume of the tool and to minimize or reduce jerkiness, backlash, and cable slack and to allow large grasping force and holding stiffness).
The apparatuses (devices, tools, systems, mechanisms, etc.) and methods described herein may address the problems described above.

Medical devices having smoothly articulating multi-cluster joints


A method and system for integrated circuit optimization to improve performance and to reduce leakage power consumption of an integrated circuit (IC). The original IC includes a plurality of nominal cells, and each of the nominal cells includes a plurality of transistors. The method creates an optimized standard-cell library from a standard-cell library. The standard-cell library includes a plurality of nominal cells, and each of the nominal cells includes a plurality of transistors. Further, an optimized IC is generated by using the optimized standard-cell library from the original IC. The optimized IC has an improved performance and reduced leakage power characteristics, as compared to the original IC.

1. Field of the Invention
This invention relates in general to the design of integrated circuits (ICs), and in particular, to the optimization of standard-cell libraries used to synthesize and optimize ICs.
2. Description of the Related Art
In the design and manufacture of modern Integrated Circuits (ICs), as the transistor geometry has decreased with scaling, high power dissipation is a major concern to IC designers. Typically, leakage power, which is the power consumed by transistors when they are not actively switching, accounts for the major part of the total power consumption in ICs. It is estimated that leakage power accounts for over half of the total power consumption in the 65 nm IC fabrication process. Therefore, IC designers seek to improve the leakage power consumption of an IC without impacting its performance characteristics. In a modern IC design, pre-designed standard-cell libraries are stored in certain databases that provide the components from which an IC is synthesized and optimized. The leakage power consumption and the performance characteristics of the IC depend on the standard-cell library used. Therefore, integrated circuit optimization requires optimization of the standard-cell library.
Several circuit-optimization techniques have been developed to control the consumption of leakage power. Certain of these circuit-optimization techniques create an optimized IC by selectively replacing cells in an existing circuit. The cells are obtained from the standard-cell library. The leakage power and performance characteristics of the optimized IC depend on the quality of the optimizer and the cells available in the library. Some of these techniques are based on the fact that modifying (hereinafter referred to as 'biasing') the gate lengths of transistors by small amounts can reduce leakage power without significant penalties in timing, area or input capacitance, without extra manufacturing cost. Essentially, timing slack is traded off for leakage power. Such techniques, used in the past, assigned the same gate length to every transistor in a cell, which resulted in suboptimal utilization of the available timing slack. Further, assigning the same gate length does not take into account factors such as the difference in the mobility of electrons, which are the principal carriers in the NMOS transistors, and the mobility of holes, which are the principal carriers in the PMOS transistors. Other factors, such as the asymmetry of rise-time and fall-time slacks, are also ignored. Therefore, with respect to the previous techniques, it is possible to intelligently decrease the granularity of length assignment to improve timing-slack utilization.
Other existing leakage reduction techniques use multiple threshold voltage (Vth) libraries, where each cell has 2-3 different Vth variants. The variants are chosen for assignments to different paths, based on the available slack on the paths. These techniques require a separate masking step in the manufacturing process of the IC, for each different Vth. This makes such techniques expensive and limits the number of available threshold voltages to 2 or 3.
Therefore, there exists a need for a method and system that can selectively assign a bias to transistor parameters, such as the transistor gate-length and the threshold voltage of the individual transistors of the cells of a standard-cell library, to improve the leakage and performance of manufactured ICs.

Method and system for integrated circuit optimization by using an optimized standard-cell library


A self-aligned silicide method with Ti deposition, reaction, strip of TiN with selectivity to TiSi.sub.2 consisting of a water solution of H.sub.2 O.sub.2 with possible small amounts of NH.sub.4 OH, phase conversion anneal, and then strip of TiSi.sub.2 filaments with a water solution of H.sub.2 O.sub.2 plus NH.sub.4 OH.

The invention relates to electronic semiconductor devices, and, more particularly, to fabrication methods for such devices.
Semiconductor integrated circuits with high device density require minimum size structures such as short gates and shallow source/drain junctions for field effect transistors ("FET"s), small area emitters for bipolar transistors, and narrow interconnection lines between devices. Short gates and narrow interconnection lines lead to higher resistance for the typical polysilicon gates and first level interconnection lines, and this increases RC time delays and slows circuit operation.
One approach to reduce the resistance of polysilicon gates and interconnection lines uses a self-aligned titanium silicide on top of the polysilicon. The silicidation process first deposits a blanket film of titanium metal and then reacts the titanium with any underlying silicon in a nitrogen atmosphere. Lastly, the process removes the titanium nitride formed from the titanium which did not become silicide. For example, see U.S. Pat. No. 4,821,085.
The removal of titanium nitride in this self-aligned silicide process requires a very high selectivity with respect to removal of the titanium silicide, otherwise the titanium silicide will be thinned and lose the advantages of siliciding. The removal of titanium nitride with the standard basic SCl solution (12.5% ammonium hydroxide solution, 12.5% hydrogen peroxide solution, and 75% water) at room temperature has a selectivity with respect to titanium silicide of roughly 7.8 to 1. This low selectively presents problems in the known silicide processes.


A dual adjustable voltage regulator combining a DC--DC switching regulator with a linear regulator implemented on a single chip is disclosed. The invention provides switching circuitry that can select between a fixed output voltage level and a user-adjustable output voltage. The circuit further provides means to automatically detect and generate power supply voltage levels as required by the system.

The present invention relates in general to integrated circuits, and in particular to a circuit that provides two adjustable voltage regulators for systems having dual supply voltages.
The semiconductor industry continues to downsize device geometries with every new generation of devices. The smaller and higher density integrated circuit devices help reduce the cost of end products and facilitate manufacture of ever shrinking portable computing systems. A related and in some applications equally important performance consideration, is the power demands of a given device. Process and circuit designers continue to focus their efforts on developing circuits that take less silicon area and consume less power.
In the case of microprocessors, for example, previous generations were designed to operate with a single 5 volt power supply. For battery-operated portable applications where power consumption is more critical, microprocessors have been designed with core circuitry running at lower voltages of, for example, 3.3 volts while the interface circuitry runs at 5 volts. This power saving technique has been widely adopted in not only other (e.g., desktop) processor designs, but also in many other types of integrated circuits including memories and programmable logic. Accordingly, current generations of microprocessors are being designed with two power supplies, a first one at for example 3.3 volts, that powers the interface, and a second lower voltage at for example 2.8 volts that powers the core circuitry.
The requirement for two power supplies, however, poses a problem for the board designer. The silver box that supplies power to a processor mother-board typically provides only 5 and 12 volt power supply voltages. The output of the 5 volt power source must therefore be switched to generate two different voltages on the mother-board. This requires using voltage down converters that can generate lower voltages of for example 3.3 and 2.8 volts from the 5 volt source. This is further complicated by the fact that different microprocessors are designed to operate with different supply voltage levels. For example, the Intel P54 processor requires a 3.5 volt supply voltage, while the Intel P55C processor uses a dual supply arrangement with a 3.3 volt power supply for the interface and a 2.8 volt power supply for the core circuitry.
Furthermore, the electrical current requirements for two different supply voltages may differ substantially. The 3.3 volt supply, for example, provides power to the interface circuitry (I/Os) that typically runs at a lower frequency of, for example, approximately 60 to 70 MHz. The CPU core, on the other hand, is powered by the 2.8 volt supply that runs at frequencies ranging from, for example, 130 MHz to 200 MHz. These exemplary numbers roughly translate to electrical current requirements of about 1 to 3 Amperes for the 3.3 volt supply, versus 5 to 7 Amperes for the 2.8 volt supply. This demands different performance characteristics for a voltage regulator.
There is a need for an efficient and cost effective solution to providing voltage regulators for systems running with multiple different power supply voltages.


A dithering torque control method that is useful for a semi-automated vehicle transmission facilitates accomplishing a desired condition in the transmission. The method is useful during an initial break torque function to relieve drive train torque so that a driver can move a manual shift lever from an engaged position to a transmission neutral position without using a clutch. The method is also useful for shifting a lever to move gearing components from a neutral position to a next desired gear. A dithering function is used to cyclically oscillate a current torque value about a target torque value that is associated with the desired transmission condition. An amplitude and period of the dithering function are determined based upon an overall gear ratio of the transmission. The dithering function begins at a point dependent on a torque value associated with the currently engaged gear. The dithering function continues until a known transmission condition is confirmed.

This invention generally relates to a method of controlling a change in a torque value of a semi-automated vehicle transmission system that oscillates a torque value about a target torque value.
Vehicle transmissions are well known and include automatic, manual and semi-automatic types. Each of the transmission types have advantages that make them suitable for various applications. Heavy duty vehicles typically include a manual or, more recently, a semi-automatic transmission. Semi-automatic transmissions of various types have been proposed. The basic principal is to assist a driver in performing a manually selected gear ratio change using a system that is at least partially automated. While such transmissions are becoming more readily useable, those skilled in the art are still trying to enhance and perfect current designs.
In conventional manual transmissions, to effect a gear change, the driver of the vehicle would manually operate a clutch and a gear shift lever. The clutch was used to disengage the output shaft of the engine from the input shaft of the transmission so that the driver would be able to move the transmission out of a current gear into a neutral position. To then re-engage a new gear, the driver would have to operate the clutch, move the lever and approximate a desired engine speed that would correspond to an appropriate torque for engaging the new gear. Traditionally, this has been a relatively difficult maneuver requiring a great degree of skill and experience.
One challenge facing a designer of a semi-automatic transmission system is to simplify the task of shifting gears and doing so in an efficient and effective manner. This invention provides an effective method for establishing conditions that simplify effecting a gear change in an efficient manner.

Torque dithering method for controlling a vehicle transmission


A recording medium (1) for hologram comprises a hologram recording layer (3) comprised of photo-polymer layer is formed on a base (2) comprised of colorless and transparent resin film, etc. and a protective layer (4) comprised of colorless and transparent resin film, etc. formed on the hologram recording layer (3). As such base (2) and protective layer (4), material having less double refraction is used. Optical axis of double refraction when such components are configured to be strip-shaped is allowed to be a direction of the longer side or a direction of the shorter side.

Holographic stereogram is prepared, e.g., by recording, in succession, onto single recording medium for hologram as strip-shaped or dot-shaped element hologram, a large number of pictures, as original picture, which are obtained by successively photographing object from different points of observation.
For example, in preparing holographic stereogram having parallax information only in the lateral direction, such an approach is employed as shown in FIG. 1 to first photograph in succession object 100 from different points of observation in the lateral direction to thereby obtain parallax picture train 101 consisting of plural pictures having parallax information in the lateral direction. It is to be noted that it is sufficient that such parallax picture train 101 is not picture obtained by actually photographing object, but may be, e.g., CAD (Computer Aided Design) picture or CG (Computer Graphics) picture generated by computer etc. Further, respective pictures 102 constituting this parallax picture train 101 are recorded in succession onto a recording medium 103 for hologram as strip-shaped element hologram in such a manner that they are successive in the lateral direction. Thus, holographic stereogram having parallax information in the lateral direction can be obtained.
In this holographic stereogram, since information of plural pictures 102 obtained by successively photographing object 100 from different points of observation in the lateral direction are recorded in succession in such a manner that they are successive in the lateral direction as strip-shaped element hologram, when observer looks at this holographic stereogram by the both eyes, two-dimensional picture images respectively imaged on his left and right eyes are different. Thus, the observer feels parallax so that three-dimensional picture image is reproduced.
Meanwhile, element holograms of the above-mentioned holographic stereogram are recorded onto recording medium for hologram using photosensitive material as recording material in a manner stated below. Namely, in recording element holograms onto the recording medium for hologram, laser beams of good coherence are branched, and one branched laser beam is irradiated in a manner perpendicular to one surface of the recording medium for hologram as projected image (object light) which has been configured to undergo two-dimensional picture modulation by picture display means, e.g., liquid crystal panel, etc. Further, the other branched laser beam is irradiated at a predetermined angle onto the other surface of the recording medium for hologram as reference light. Thus, interference patterns are formed as a change of refractive index or transmission factor at the photosensitive material of the recording medium for hologram so that element holograms are recorded.
As a recording medium for a hologram, there may be used, e.g., a recording medium of the type in which a hologram recording layer consisting of photosensitive material such as photo-polymer, etc. is configured to be put between the protective layer and the base. The object light and the reference light are irradiated in the state of linear polarization from one surface and the other surface of the hologram recording layer to form interference patterns to record element holograms. It is to be noted that the photosensitive material of the hologram recording layer is not limited to photo-polymer, but there may be used other photosensitive material, e.g., silver salt material or gelatin bichromate, etc.
As the protective layer and the base of such recording medium for hologram, the so-called optical material such as optically transparent resin or glass, etc. is used. Further, as such protective layer and base, there is exemplified, e.g., transparent resin plate of such as polycarbonate, polyolefin, PMMA (polymethyl methacrylate), etc. as described in the Japanese Patent Publication No. H6-214117. Furthermore, there are exemplified PMMA (polymethyl methacrylate), polycarbonate, polyolefin, diethylene glycol bisallyl carbonate, polystyrene, hard polyvinyl chloride, methylmethacrylate-styrene copolymer resin, styrene-acrylonitrile copolymer resin, and poly (4-methylpentene-1), etc., as described in the Japanese Patent Publication No. H10-119163. Further, Japanese Patent Publication No. 11-338336 discloses as examples silicon compositions, etc. of condensation reactive type, addition reactive type, non-solvent type, ultraviolet hardening type and electron beam hardening type, etc.
In addition, as structure of hologram recording medium including hologram recording layer consisting of photo-polymer layer serving as photosensitive material as described above, there are, as the structure already announced, "Stephen A. Zager and Andrew M. Weber, "Display holograms in Du Pont's Ommidex films", Proc. of SPIE, Vol. 1461 (1991) pages 58–67 [DuPont]", "T. J. Trout, W. J. Gambogi and S. H. Stevenson, "Photopolymer Materials for Color Holography", Proc. SPIE, Vol. 2577 (1995) pages 94–105", "Sylvia H. Stevenson, "DuPont multicolor holographic recording films", Proc. of SPIE, Vol. 3011 (1997)", "Masami Kawabata, Akihiko Sato, Iwao Sumiyosi and Toshihiro Kubota, "Photopolymer system and its application to a color hologram" Applied Optics, Vol. 33, No. 11 (Apr. 10, 1994) pages 2152–2156", etc.
However, optical materials having small difference between refractive indexes of double refraction are expensive. Further, according as double refraction becomes smaller or lesser, materials are limited, resulting in higher cost.
As described above, object light and reference light are incident on the hologram recording layer as linearly polarized light to form interference patterns. However, when there is double refraction characteristic (birefringence) in the base or the protective layer, plane of polarization becomes oblique or changes into elliptically polarized light when such light is passed (transmitted) through the base or the protective layer. For this reason, contrast of interference pattern within the hologram recording layer is lowered.
As a method of solving such a phenomenon, there is mentioned a method of reducing retardation which is one of index values of double refraction, i.e., reducing difference between refractive index in the direction in parallel to the optical axis and refractive index in the direction perpendicular to the optical axis as described in the Japanese Patent Publication No. H7-114329, for example.
However, optical materials having small difference between refractive indexes of doble refraction are expensive.; Further, according as double refraction becomes smaller or lesser, materials are limited, resulting in higher cost.
In addition, in development and fixing of photosensitive material such as silver salt material, gelatin bichromate, photo-polymer, etc. used in the hologram recording layer, development process and fixing process are carried out by acid/alkali, ultraviolet ray/visible ray/infrared ray, heat of high temperature or combination thereof, etc.
Under such circumstances, optical materials used in the protective layer and the base are also required to have various resistances or tolerances, e.g., chemicals resisting property such as acid resistance or alkali resistance, etc., water proof property such as moisture proof property or swelling proof property, etc., light proof property such as yellowing proof property, etc., weathering resistance property such as heat resistance property or yellowing resistance property, etc.
Accordingly, optical materials having less double refraction and provided with the above-mentioned resistances are limited and are therefore very expensive.

Recording medium for hologram, hologram recording apparatus and hologram recording method


A method of switching taps of an on-load tap changer includes providing a main finger, a first side finger including a first solid state switch and a second side finger including a second solid state switch. The main finger, the first side finger and the second side finger are utilized to provide a connection between the taps and a power terminal of the on-load tap changer. The method also includes triggering the on-load tap changer to shift the fingers from a first tap to a second tap of the on-load tap changer when a tap change signal is received and utilizing the first solid state switch and the second solid state switch to commutate a current during the tap change operation.

Embodiments of the system relate generally to a field of voltage regulation and more specifically to an on-load tap changer for power delivery.
Conventionally, electricity is generated in large-scale power plants that are connected to a transmission grid through step up transformers. Electrical power is transmitted over a transmission system over long distances at very high voltages. At distribution substations the voltage is stepped down and power is supplied to different loads within a distribution grid. Voltage regulation in the distribution grid is typically achieved either through On-Load Tap Changing (OLTC) transformers or voltage regulators. Capacitor banks are also widely used in many utilities to support the voltage in distribution grids, where voltage variations are mainly caused by slow variation of loads connected to the distribution system. The increasing share of intermittent and highly variable renewable energy generation connected at distribution level leads to larger and more frequent voltage fluctuations in distribution grids, which requires more flexibility in network voltage regulation. As a consequence, on-load tap changers in distribution grids with large amount of renewable energy generation are being utilized more intensively and extensively.
On-load tap changers have been widely used for power transformers and voltage regulators for many years. Several types of on-load tap changers, both mechanical and electronic, are available in the market. Mechanical on-load tap changers allow for in-service operation, but have demanding mechanical requirements. Each tap changing operation of mechanical tap changers leads to a certain amount of arcing between tap contacts and moving finger contacts. Arcing leads to slow deterioration of the transformer oil and the wear of the mechanical contacts. The lifetime of a mechanical tap changer is hence limited by the number of tap changing operations. Conventional on-load tap changers have nevertheless relatively long lifetime of 15-20 years. This is mainly due to the relatively low number of tap changing operations required to regulate the voltage variations due to load variations. However, due to larger and faster voltage fluctuations in distribution networks caused by the increasing share of distributed renewable energy sources, on-load tap changers are required to switch much more often than before. This leads to much higher maintenance requirements and limited lifetime.
The main drawback of mechanical on-load tap changers is unavoidable arcing between the tap contacts and the moving finger contacts when a tap is changed. Purely electronic on-load tap changers on the other hand do not have any moving finger contacts. Each tap contact is connected to the load through a solid-state electronic switch. The tap position is selected by switching on the corresponding electronic switch (i.e. conducting), while all other switches are switched off (i.e. not conducting). Changing from one tap position to the other is carried out by commutating the current from one electronic switch to the next. The current commutation and tap change is therefore achieved without arcing due to the typically very fast switching capabilities of solid-state switches. Although electronic on-load tap changers are highly flexible and can operate arc-free and would therefore substantially reduce maintenance requirements as compared to mechanical on-load tap changers, they also have certain disadvantages. The main disadvantage is the cost of electronic switches, also because an electronic switch is required for each tap position, which further increases the cost when large number of taps is needed. The second disadvantage is the higher losses of electronic switches compared to mechanical contacts.
Therefore, there still exists a need for an economically more viable as well as technically reliable and efficient alternative solutions for on-load tap changers.


It is an object of the present invention to provide a light-emitting substance which is resistant to repetition of an oxidation reaction. It is another object of the invention to provide a light-emitting element which is resistant to repetition of a reduction reaction. An aspect of the present invention is an anthracene derivative represented by a general formula (1). In the general formula (1), R1 represents hydrogen or an alkyl group having 1 to 4 carbon atoms; R2 represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms, which may have a substituent or no substituent; Ph1 represents a phenyl group, which may have a substituent or no substituent; and X1 represents an arylene group having 6 to 15 carbon atoms.

In recent years, many of light-emitting elements used for displays and the like have a structure in which a layer containing a light-emitting substance is sandwiched between a pair of electrodes. Such light-emitting elements emit light when excitons which are formed by recombination of electrons injected from one electrodes and holes injected from the other electrodes return to a ground state.
In the field of light-emitting elements, in order to obtain a light-emitting element having high light-emitting efficiency and high chromaticity or a light-emitting element in which optical quenching and the like can be prevented, various researches about substances which become materials for manufacturing such a light-emitting element have been carried out.
For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-131541) discloses a material for an organic EL element having high light-emitting efficiency and long lifetime.
Further, in a light-emitting element, current flows between electrodes by transportation of holes or electrons. In this case, a light-emitting substance which has received holes or electrons or the like, or, a light-emitting substance which has been oxidized or reduced or the like sometimes does not return to a neutral state and is changed into a substance having a different property. When such changes of the property of the light-emitting substance are accumulated, a characteristic of the light-emitting element may also be changed.
Therefore, development has been demanded on a light-emitting substance of which a property is difficult to be changed due to oxidation or reduction.

Anthracene derivative, and light-emitting element, light-emitting device, and electronic appliance using the same

Semiconductor Energy Laboratory Co., Ltd.


Vibration or the like is prevented for long-term use by normalizing, with operation continuing, a tread of a crawler belt link through grinding in an early stage where uneven wear such as corrugated wear occurs. With a crawler belt of a crawler vehicle wound, an abrasive plate for grinding the tread of the crawler belt link is disposed to contact the tread. While the crawler vehicle does normal traveling work, the abrasive plate corrects the tread of the crawler belt link for the uneven wear. The vibration of a vehicle body can thus be prevented during travel with no uneven wear produced.

In a conventional crawler structure of a crawler type work vehicle, a traveling crawler belt is formed of crawler belt links wound endlessly between a sprocket and an idler that are disposed in respective rear and front positions of a main frame. This crawler belt is held by a plurality of track rollers on a ground-contact side, is held by carrier rollers on a non-ground-contact side to maintain uniform tension and is driven by being wound around a sprocket member of the sprocket.
In such a crawler structure, when a tread of the crawler belt link is in rolling contact with the track roller, the carrier roller or the idler during travel, the tread wears down unevenly, thus showing corrugated wear. Such uneven wear is caused, for example, during travel on soft ground G as shown in FIG. 13(a). Since soft ground G easily causes sinking, earth and sand easily adhere to the crawler belt. The earth and sand adhere between tread 51 of crawler belt link 50 and idler 55, thus causing the wear when tread 51 slides in surface D of contact with idler 55. Moreover, as shown in FIG. 13(b), when ground G is soft enough to easily cause sinking as in the above case, the earth and sand adhere to respective ends of treads 51 of crawler belt links 50 at track roller 56, thus causing the wear during slide. Briefly speaking, traveling on the soft ground quite often causes the part contacting idler 55 or track roller 56 to show severe partial wear because crawler belt 52 sinks easily, and consequently, tread 51 of crawler belt link 50 shows corrugated wear 53 as illustrated in FIG. 13(c). A high degree of corrugated wear results in vibration of a vehicle body during travel on a stable hard road, and when the corrugated wear becomes noticeable, noise is caused, thus adversely affecting an environment. Accordingly, the link must be replaced when tread 51 of crawler belt link 50 shows the severe corrugated wear, and such replacement reduces cost efficiency.
For solving the problem of wear of the crawler belt link, no concrete means is proposed. A known measure against the wear of the crawler belt link is disclosed, for example, in Japanese Utility Model Unexamined Publication No. H01-125286. According to this publication, a flange of the track roller is ground according to wear of the tread of a track link (crawler belt link) at the track roller. The flange is thus prevented from contacting a connecting pin boss of the track link, whereby the use of the crawler belt link is extended.
However, the measure disclosed in Japanese Utility Model Unexamined Publication No. H01-125286 is not a technique adapted to solve the problem that is addressed by the present invention because this measure is based on the assumption that the link shows overall wear. This measure solves problem that only the initial flange maintains its size as a result of the tread showing the wear at the roller where relative wear is caused, by grinding the flange according to the wear of the tread. As described earlier, no measure against the corrugated wear or uneven wear of the crawler belt link is found, so that there is no other choice but to replace the link. Accordingly, the reduction of running costs remains unattained under present circumstances.
In view of such circumstances, the present invention aims to provide a crawler belt link grinding system and a crawler structure including the grinding system that allow a tread to withstand long-term use by normalizing, with operation continuing, the tread through grinding in an early stage where uneven wear such as corrugated wear occurs.

Crawler belt link grinding system and crawler structure


A foldable rod assembly includes first and second rods of predetermined dimensions and having connecting ends with pivot holes, and a coupler unit for coupling pivotally the connecting ends. The coupler unit includes two elongate plates respectively having right and left longitudinal sides, upper and lower transverse sides, and upper and lower pivot holes disposed in symmetry to a middle line between the transverse sides. A blocking member extends transversely from the right longitudinal side proximate to the upper transverse side. Two protrusions extend from the left longitudinal side parallel to the blocking members respectively and proximate to the transverse sides. Two pins are inserted into the pivot holes of the elongate plates and the connecting ends of the first and second rods when the elongate plates are opposed to each other with a first transverse distance defined therebetween which is slightly larger than the predetermined dimension of the rods while one of the elongate plates is turned 180 degrees relative to the middle line so that the blocking members are located in a plane defined by the right longitudinal sides of the elongate plates at a diagonal position. The protrusions of the elongate plates define a second transverse distance which is smaller than the predetermined dimensions for sliding retention by the connecting ends when the latter are folded about the pin members.

1. Field of the Invention
The invention relates to a rod assembly, more particularly to a foldable rod assembly for use in a detachable closet such that the closet can be folded into a suitcase.
2. Description of the Related Art
A conventional foldable rod assembly includes a first rod, a second rod, and a coupler unit. Each of the first and second rods has a connecting end of predetermined dimension provided with a pivot through hole which extends in a direction transverse thereto. The coupler unit includes an elongated piece having left and right longitudinal sides, upper and lower transverse sides, upper and lower pivot holes which are disposed in symmetry to a middle line between the upper and lower transverse sides, and a tubular sleeve member movably disposed on the elongated piece. The sleeve member has a longitudinal length greater than that of the elongated piece. A pair of pinmembers extend into the pivot through holes of the connecting ends of the first and second rods and into the upper and lower pivot holes of the elongated piece such that the connecting ends of the first and second rods are pivotable relative to each other. The tubular sleeve member is sleeved on one of the first and second rods prior to pivotal connection of the connecting ends of the first and second rods on the elongated piece. The sleeve member has upper and lower portions threadedly fastened to the first and second rods so as to enclose the connecting ends and the elongated piece therein, thereby retaining the first and second rods in a straight line.
A drawback of the conventional rod assembly resides in that, during storage, the tubular sleeve member must be unfastened from the first and second rods to permit folding of the connecting ends thereof relative to each other. Since several tubular sleeve members are needed to interconnect several pairs of the first and second rods in the conventional foldable rod assembly, it takes a considerably long time to disassemble the sleeve members from the first and second rods during folding, which accordingly inconveniences the user.

1F, No. 12, Lane 106, Sec. 3, Min-Chuan E. Road


Systems and methods enhancing loudspeaker audio performance in thin devices, such as mobile computing platforms and/or communication handsets. In some embodiments, a laminate panel including a dielectric membrane and one or more conductive traces forming an inductive loop suitable wireless charging and/or near field communication (NFC) element is employed as a loudspeaker driven at audio frequencies. In some embodiments, the laminate panel is driven with one or more piezoelectric element. In some embodiments, the laminate panel is of a stiffness and mass to provide a frequency response distinct from that of integrated micro-speakers for a 2.1 audio solution with wider bandwidth than is possible with micro-speakers employing back-side cavities. In some embodiments, the frequency spectrum spanned by the laminate panel loudspeaker enables a tweeter design lacking back-side cavities for smaller device form factor. In some ultra-small form factors, micro-speakers may be eliminated from the platform with the laminate panel providing the only loudspeaker diaphragm for the mobile platform.

Noting that sound is created by the fluctuation of air pressure caused by the movement and/or vibration of a given object, the impact of loudspeaker size on loudspeaker performance is clear. It is also apparent that with the trend toward slim/thin form factors in mobile computing platforms, such as smart phones and other mobile/wearable devices, it is increasingly difficult for device manufacturers to design loudspeaker solutions. The size of loudspeakers that fit inside modern mobile devices are simply too small to move large volumes of air. As a result, loudspeaker performance in mobile devices has stagnated or even degraded in recent years.
FIG. 1A illustrates a mobile computing device assembly 101, which includes a chassis 102 and a pair of micro-speakers 105 affixed to chassis 102. A display, microprocessor and other integrated circuitry, as well as a battery may be installed into assembly 101 in any conventional manner. During device operation, loudspeaker membrane movement within micro-speaker 105 is to generate audio output 115. Micro-speaker(s) 105 is driven to provide monaural or stereo output. Micro-speakers 105 are typically tuned to a resonance frequency that enables greater loudness or sound pressures. FIG. 1A further illustrates a conventional micro-speaker design employing a back-side cavity 110, also known as an "air spring" which reinforces the micro-speaker sensitivity (loudness). The back-side cavity encloses a back-side of the loudspeaker membrane opposite a front cavity through which the sound is outlet. The size of the back-side cavity is a function of the micro-speaker design and desired frequency response. Often, a third, or more, of a micro-speaker volume is occupied by the back-side cavity. To accommodate the micro-speaker with back-side cavity, a device design may either increase chassis length (e.g., y-dimension) or chassis thickness (e.g., z-dimension).
FIG. 1B illustrates a frequency response 120 typical of a mobile computing device employing the micro-speaker design illustrated in FIG. 1A. Sensitivity at a distance from the source of 10 cm is shown for a 2V. (500 mW) drive signal. Frequency response 120 has a peak at a resonance frequency of around 1 kHz associated with the back-side cavity, and another peak at a resonance frequency of around 4-5 kHz associated with front-side acoustics. While sound pressure is significant at the micro-speaker resonance frequencies, perceived loudness rolls off rapidly within a few hundred Hertz on either side of the resonance frequencies for a narrow band output perceived by the human auditory system as "thin" sounding. Such a perception impedes a user's enjoyment of hands-free calls, audio/video (A/V) playback, and gaming.
To facilitate a continued shrinking of mobile device platform dimensions, loudspeaker performance may continue to decline until loudspeaker integration is discontinued, at which point device users will be required to rely exclusively on ear buds, or other auxiliary audio speakers. Loudspeaker solutions that can augment existing micro-speaker designs to achieve greater audio performance, or replace existing micro-speaker designs to enable more flexibility in device form factor and scalability are therefore advantageous.

Loudspeaker with laminate panel for mobile computing platforms


A method is provided for operating a medical imaging X-ray device. The method records an earlier individual image of a series of images of a patient using a recording facility. The location of a medical component is identified, and the medical component is localized in the earlier individual image using a computing facility. A subregion of the earlier individual image is specified, determined by the position of the medical component localized in the earlier individual image and with the localized medical component represented. A later individual image is recorded and the medical component is localized in the later individual image. The later individual image is displayed, the later individual image averaged exclusively region-specifically in the region of the medical component with the subregion of the earlier individual image. Method acts are repeated with the displayed individual image as the earlier individual image to enhance visibility of the medical component.

With X-ray based medical imaging, the following simple relationship applies: the greater the dose invested, the better the quality of an X-ray image because there is reduced image noise with a higher dose. Numerous surgical interventions require good visibility of a medical component in a patient's body (e.g., a vessel support device, known as a stent) for successful therapy (e.g., cardiovascular therapy). Here, good visibility is characterized by high contrast, low noise and good resolution of the X-ray image. During such interventions, it is necessary to ensure that the medical component (e.g., the stent) is positioned correctly relative to other stents and/or side branches from a vessel and that the stent is correctly deployed. To verify this, it is generally also necessary to administer a contrast agent. It may also be necessary to identify any damaged elements of the medical component (e.g., a broken stent) to enable suitable measures to be taken.
The best way of enhancing the visibility of a medical component during a surgical intervention in moving body regions is to create a corresponding X-ray image in a short time and with a corresponding high dose. For example, optimally, the recording time for an X-ray image or X-ray recording during a cardiologic intervention is less than 6 milliseconds because the stent is moved by the beating of the heart. Consequently, longer recording times are associated with motion unsharpness and visibility of the stent is impaired. However, the power of X-rays is limited and it is not possible to achieve the dose required for good visibility in such short radiation pulses of less than 6 milliseconds.
One way to enhance visibility, even in this kind of situation with a moving medical component, is to identify markers (e.g., so-called balloon markers of the medical component, such as stent balloon markers) in the individual X-ray images of a series of X-ray images or a film of this kind and to register the images in the series to one another on a marker-pair basis (e.g., to assign respective image points of the images representing the same balloon markers to one another and then to average the images). For example, the registration of the individual images may take place by affine transformation. One precondition for the best way of carrying out this method is for the balloon markers to be positioned approximately at the start and end of the stent for which visibility is to be enhanced and for there to be no relative movement, or only a slight relative movement, between the markers and the medical component (e.g., the stent) during the series in the scene. The resulting image may then be further optimized with suitable image processing routines so that the medical component is visible against a smooth background. This method is known and described in numerous patents (e.g., U.S. Pat. No. 8,311,308B2 or U.S. Pat. No. 8,433,115B2) and inter alia integrated in current Siemens products as "Clear Stent" or "Clear Stent Live".
With the Clear Stent method, first, a series of images including individual images is recorded with corresponding markers and the medical component, the balloon markers and the stent. When the recording is finished, an algorithm evaluates the individual images using the method described and generates a static result image. This procedure is sometimes too slow for surgical interventions because the physician has to wait for the duration of the recording time plus the algorithm calculation time before commencing or continuing the therapy.
In the Clear Stent Live method, to speed up the method, first, a number of individual images is recorded in an initial phase 1 (e.g., over one second or 10-15 individual images). The markers are identified (e.g., by a statistical analysis of the individual images recorded in phase 1) in a subsequent further phase 2. As soon as the markers have been successfully identified and localized, a third phase 3 is started. In this subsequent phase 3, the current individual image is continuously sent to the algorithm (e.g., during the ongoing recording), and the algorithm calculates, based on the result of phase 2, the coordinates of the markers, and hence the stent, in this current individual image to be displayed. Finally, all subsequently recorded individual images are spatially registered directly or indirectly via the identified and localized markers on the first individual image from phase 3 and time averaging (e.g., floating or recursive averaging) of the individual images registered to one another is performed.
As a result of the registration of the individual images to one another, averaging is performed using the image points representing the same object, namely the stent as a medical component and the marker pairs as markers and the parts of the patient (e.g., vessels). It is also additionally possible to optimize the section of the displayed image (e.g., the so-called windowing of the image), and to perform edge enhancement for better visibility of the stent. The result is a motion-stabilized scene relative to the marker pair, and hence the stent, in the environment of the marker pair with enhanced image quality. However, image parts at a greater distance to the marker pair are less sharp with this method. Unlike the method described above, this method provides images in real time so that the physician receives immediate optical feedback on an action (e.g., a displacement of the stent). The disadvantage is that parts of the image are blurred and the movements of the physician are depicted inversely because the movements are depicted relative to the stationary marker pair.

Method for operating an X-ray device with enhanced depiction of a medical component