A magnetic nerve stimulator system is comprised of a core constructed from a material having a high field saturation with a coil winding. A thyrister capacitive discharge circuit pulses the device. A rapidly changing magnetic field is guided by the core, preferably vanadium permendur. For task specific excitation of various nerve groups, specially constructed cores allow for excitation of nerves at deeper levels with higher efficiency than is possible with air-core stimulators. Among the applications possible with this invention are treatment of incontinence, rehabilitation of large muscle groups in the leg and arm, and excitation of abdominal wall muscle groups to aid in weight loss and metabolic rate increase. A C-shape is employed for focussing the stimulation as desired.

A nerve cell can be excited in a number of different ways, but one direct method is to increase the electrical charge within the nerve, thus increasing the membrane potential inside the nerve with respect to the surrounding extracellular fluid. One class of devices that falls under the umbrella of Functional Electrical Stimulation (FES) realizes the excitation of the nerves by directly injecting charges into the nerves via electrodes which are either placed on the skin or in vivo next to the nerve group of interest. The electric fields necessary for the charge transfer are simply impressed via the wires of the electrodes.
FES is accomplished through a mechanism which involves a half-cell reaction. Electrons flow in wires and ions flow in the body. At the electro-electrolytic interface, a half-cell reaction occurs to accomplish the electron-ion interchange. Unless this half-cell reaction is maintained in the reversible regime, necrosis will resultxe2x80x94partially because of the oxidation of the half-cell reaction and partially because of the chemical imbalance accompanied by it.
The advantage of FES is that the stimulation can usually be accomplished from extremely small electrodes with very modest current and voltage levels. The disadvantage however, is that it involves half-cell reactions. Most rehabilitation programs using FES place the electrodes directly on the skin. A conductive gel or buffering solution must be in place between the electrodes and the skin surface. Long term excitation of nerve or muscle tissue is often accompanied by skin irritation due to the current concentration at the electrode/skin interface. This problem is especially aggravated when larger excitation levels are required for more complete stimulation or recruitment of the nerve group.
By contrast, magnetic stimulation realizes the electric fields necessary for the charge transfer by induction. Rapidly changing magnetic fields induce electric fields in the biological tissue; when properly oriented, and when the proper magnitude is achieved, the magnetically induced electric field accomplishes the same result as realized by FES, that of transferring charge directly into the nerve to be excited. When the localized membrane potential inside the nerve rises with respect to its normal negative ambient level of approximately xe2x88x9290 millivolts (this level being sensitive to the type of nerve and local pH of the surrounding tissue), the nerve xe2x80x9cfires.xe2x80x9d
The present invention is especially targeted at applications that are not suited for the use of implanted electrodes. The invention is designed for non-invasive external stimulation of selected nerve or nerve groups, particularly in certain applications. In these applications, which include incontinence and rehabilitation of muscle groups as well as potential weight loss treatment, the desired excitation levels using FES often fall outside of what might be considered comfortable limits. That is, the electrical current that ideally would be injected through the skin to excite the muscle groups of interest often leads to some skin irritation with time. The invention can also be used even in applications where this is not the case, as the use of gels and direct electrode/skin placement is inconvenient and is often resisted by the patient.
As opposed to FES, magnetic excitation has the attractive feature of not requiring electrode skin contact. Thus, stimulation can be achieved through the clothing that is being worn. This overcomes the objection of inconvenience and preserves the patient""s dignity. Secondly, because there is no direct contact, stronger excitation levels can be realized without undue additional skin irritation. A contribution offered by the present invention is the ability to achieve higher levels of focusing of the magnetic field and thus stimulation within the patient. Commensurate with this greater level of focusing comes some flexibility in the number of possible applications that might be targeted. Also accompanying the focusing is a higher level of power efficiency. Typically, the devices being designed by the methods outlined in this invention reduce the magnetic reluctance path by a factor of two. This reluctance reduction translates into a diminution of the current by the same factor and a fourfold reduction in power loss.
Magnetic stimulation of neurons has been heavily investigated over the last decade. Almost all magnetic stimulation work has been done in vivo. The bulk of the magnetic stimulation work has been in the area of brain stimulation. Cohen has been a rather large contributor to this field of research (See e.g., T. Kujirai, M. Sato, J. Rothwell, and L. G. Cohen, xe2x80x9cThe Effects of Transcranial Magnetic Stimulation on Median Nerve Somatosensory Evoked Potentialsxe2x80x9d,Journal of Clinical Neurophysiology and Electro Encephalography, Vol. 89, No. 4, 1993, pps. 227-234.) This work has been accompanied by various other research efforts including that of Davey, et al. (See, K. R. Davey, C. H. Cheng, C. M. Epstein xe2x80x9cAn Alloy-Core Electromagnet for Transcranial Brain Stimulationxe2x80x9d, Journal of Clinical Neurophysiology, Volume 6, Number 4, 1989, p.354); and that of Epstein, et al. (See, Charles Epstein, Daniel Schwartzberg, Kent Davey, and David Sudderth, xe2x80x9cLocalizing the Site of Magnetic Brain Stimulation in Humansxe2x80x9d, Neurology, Volume 40, April 1990, pps. 666-670). The bulk of all magnetic stimulation research attempts to fire nerves in the central nervous system.
The present invention differs in a number of respects from previous research efforts. First, the present invention has primary applicability to the peripheral nervous system, although it can be employed to stimulate nerves in the central nervous system as well. Second, and more importantly, the previous nerve stimulation work is dominated almost exclusively by air core coils of various shapes and sizes. The present invention is directed to the use of a magnetic core, more specifically a permeable core having a high field saturation, with the most preferred material being vanadium permendur. Among the air core stimulators are circles, ovals, figure eights, and D shaped coils. The coils are normally excited by a capacitive discharge into the winding of the core of these coils. This exponentially decaying field has a time constant typically in the neighborhood of 100 microseconds. Typical target values for the magnetic field peak happen to be near two Tesla. J. A. Cadwell is perhaps the leader among those who are now using and marketing these air core stimulators. Among his primary patents is U.S. Pat No. 4,940,453 entitled xe2x80x9cMethod and Apparatus for Magnetically Stimulating Neuronsxe2x80x9d Jul. 10, 1990. There are a number of power supplies all of which operate on a basic capacitive type discharge into a number of air core coils which are sold with his units. Various shaped coils are being explored at this time. One such coil is a cap shaped device which fits over the motor cortex (K. Krus, L. Gugino, W. Levy, J. Cadwell, and B. Roth xe2x80x9cThe use of a cap shaped coil for transcranial stimulation of the motor cortexxe2x80x9d, Journal of Neurophysiology, Volume 10, Number 3, 1993, pages 353-362).
Some efforts are being given to various circuits used to fire these air core coils. H. Eton and R. Fisher offer one such alternative in their patent xe2x80x9cMagnetic Nerve Stimulatorxe2x80x9d U.S. Pat. No. 5,066,272 Nov. 19, 1991. They suggest the use of two capacitorsxe2x80x94one to capacitively discharge into the coil of interest, and a second to recover the charge from the inductive energy resident in the coil. The circuit used in the present invention accomplishes the same objective with a single capacitor.
Some stimulation research is being performed on the peripheral nervous system (See e.g., Paul Maccabee, V. Amassian, L. Eberle, and R. Cracco, xe2x80x9cMagnetic Coil Stimulation of Straight and Bent Amphibian and Mammalian Peripheral Nerve in vitro: Locus of Excitation,xe2x80x9d Journal of Physiology, Volume 460, January 1993, pages 201-219.) The bulk of Maccabee""s work is however targeted for cranial excitation. The applications of the present invention focus on the peripheral nervous system although it can be used on the central nervous system, as well.
An object of the present invention is to provide a magnetic nerve stimulator for exciting nerves of the peripheral nervous system.
A further object of the present invention is to provide a magnetic nerve stimulator for non-invasive stimulation of nerves within the peripheral nervous system.
A further object of the present invention is to provide a nerve stimulator for the production of magnetic fields of significant depth and focusability to stimulate deep nerves within a human.
A further object of the present invention is to provide a magnetic nerve stimulator which can produce magnetic fields which can be focused on internal peripheral nerves to effect non-invasive nerve stimulation.
A further object of the present invention is to provide a magnetic nerve stimulator for the treatment of bladder and urinary disorders.
A further object of the present invention is to provide magnetic nerve stimulators for the treatment of incontinence.
A further object of the present invention is to provide a magnetic nerve stimulator for muscle rehabilitation and/or conditioning.
A further object of the present invention is to provide a magnetic nerve stimulator for use in assisting with weight loss.
Further objects of the invention will become apparent in connection with the disclosure provided herein.
To accomplish the objectives of the present invention, a magnetic nerve stimulator is provided herein which can be used to stimulate nerves without the need for surgery. Magnetic stimulation of peripheral nerves has the advantages of convenience and threshold variability over competing FES systems. An advance of the present invention over competing magnetic nerve stimulators is in the use of a highly saturable magnetic core, i.e. a permeable core of high field saturation, and in the design of the magnetic core stimulator itself.
In the preferred embodiment, the magnetic nerve stimulator is preferably constructed using a core of a magnetic or magnetizable material. A permeable material having a high field saturation is utilized, with the preferred core having a field saturation of at least 1.5 Tesla. Some suitable materials for the core include vanadium permendur, orthinol, metallic glasses (metglass), permalloy, supermalloy, powdered iron, and the silicon irons or silicon steels, in particular, 3% grain oriented steel (magnesil). Ferrite can also be used, although it is not preferred, due to the fact that it saturates at 0.5 T.
In accordance with the present invention, it is highly preferred that an open core be used. Toroidal cores are not preferred, as it is has been found that an open core can be more effectively utilized to focus the magnetic field produced by the stimulator, and as the suitability of toroidal cores have been found to be limited to invasive applications. By the term open core, an arc shaped core spanning an angle less than 360 degrees is intended. A 180 degree core is very convenient for using the material efficiently since two cores can be constructed from every mandrel. A core having a larger angle (e.g. 210-220 degrees) can also be used. These cores are more focussed, although they have a smaller penetration depth. Alternatively, cores of smaller or greater angles can be used in non-preferred embodiments.
In the current embodiments of the invention, it is an objective to xe2x80x9cfirexe2x80x9d a coil having approximately a 100 microsecond characteristic decay time, five (5) to fifty (50) times per second. The system must be reasonably efficient and reliable to fire at such a high repetition rate. Firing rates of 5 to 10 Hz are known to be effective for treating urinary stress incontinence using FES. Higher stimulation rates (e.g. fifty (50) Hz) have proved useful for treating irritative symptoms of urinary frequency and urgency. Sustained contractions occur above fifteen (15) Hz. As medical knowledge advances, various and as further research is conducted, other firing rates of higher or lower frequencies, or of particular excitation patterns, may prove useful in specific applications.
The exact stimulation frequency will be varied somewhat depending on the requirements of the application in need. Sometimes muscle groups will need to be excited for a five second period, followed by rest for a five second period and then be stimulated continuously for another five seconds and then rest again. While they are being stimulated, it is often desirable to have the muscle groups in a sustained contraction. This requirement dictates the necessity of continuing to pulse the cores at a repetition rate of 15 Hz. Because of the large currents involved during any given firing of the core, it is necessary to make the cores as efficient as possible. It is desirable to focus the magnetic field into the region targeted for stimulus to the exclusion of surrounding regions. The specially designed cores offered by this invention realize that focusability, whereas the air core coils used by the prior art do not.
With respect to the core configuration, the simplest core configuration of the present invention is that of a xe2x80x9cCxe2x80x9d shaped core. The span of the xe2x80x9cCxe2x80x9d must be carefully chosen; the span affects both the penetration depth and the magnitude of the field. Of additional importance is the construction of the core. The best cores are constructed from thin laminate materials having a high field saturation. A typical core can be wound using two mil stock of vanadium permendur. A long ribbon of such material is wound on a mandrel (e.g. a mandrel of wood or plastic) for the radius, thickness and depth desired. Each side of the ribbon is coated with a thin insulative coating to electrically isolate it from its neighbor. A generic core that might be used at various locations around the body can span an angle of approximately 180-220xc2x0. Once the ribbon has been wound on the mandrel to the desired dimensions, it is dipped in epoxy to freeze its position. Once the epoxy has cured, the mandrel is removed and the core cut for the span of angle desired. The cut will destroy the electrical isolation of adjacent laminations. Each cut must be finely ground so that it is smooth, and then a deep etch performed. The deep etch is performed by dipping each of the cut ends in an acid bath. This causes the cut ends to delaminate slightly, but maintains the electrical isolation of the laminations. Failure to perform this deep etch results in considerable eddy current loss and heating at the cut ends of the core. Following the deep etch, the ends are brushed with epoxy to maintain the shape and structural integrity of the core. The final step of the construction is to wind a coil of insulated wire about the core. A typical inductance for a core of this type is about 30 xcexcH. The present invention, however, may be practiced at other inductances or magnetic field strengths, as well.
In the simplest configuration, each core has only one winding. The winding is excited by an exponentially decaying pulse with a characteristic time of about 100 xcexcs. The actual signal has a ringing period of about that time within an envelope that is exponentially decaying so that only two to three cycles are ever witnessed by the coil current. The excitation is repeated on a period of about approximately 5-50 Hz. As stated above, the repetition cycle of these patterns will be varied according to the application. The circuit usually consists of a transformer which feeds into a full wave rectifier bridge. The bridge voltage charges the capacitor; the charge on the capacitor is triggered with a silicon control rectifier to drive current into the coil. The return charge coming back through the coil the second time is fed through the diode back into the capacitor to prepare the circuit for the second phase of excitation.
There are at least three important target applications for the present inventionxe2x80x94incontinence, muscle rehabilitation, and weight control treatment. For the treatment of incontinence, it is necessary to stimulate the pelvic floor muscles. Such a stimulation is achieved by concentrating and focusing magnetic flux directly up the vaginal cavity. One suitable core which is capable of realizing this objective is constructed by combining two individual xe2x80x9cCxe2x80x9d cores each spanning an angle of about 180xc2x0. The legs of the cores are brought together in a central region. The common central leg of the two xe2x80x9cCxe2x80x9d cores is wound by a coil and the return path for the flux is split between the two xe2x80x9cCxe2x80x9ds. The cores themselves fit proximally and distally under a chair which the patient sits on during treatment.
A second area of application is in the rehabilitation of muscles. The primary muscle groups targeted are the thigh, calf, biceps, and triceps. The geometry is similar for all these applications, and thus a cylindrical extension around the muscle is used. Although one solution for this problem is a simple xe2x80x9cCxe2x80x9d core and coil which is moved around by the discretion of the patient, an alternative stimulator resembles the tubular shape motors used in electromechanics to propel a secondary member down a tube. Here the geometry would necessarily require a hinged tubular shape having recesses or slots which would run azimuthally around the muscle group to be stimulated. The coils of the stimulator fits in these recesses or slots and the surrounding structure would again be a laminated vanadium composite. If the structure were fitted with two or three coils, they could be stimulated in a phased arrangement.
Such an excitation would have the effect of kneading the muscle tissue group along its longitudinal axis. This particular excitation pattern may be instrumental in more fully recruiting larger muscle groups such as the hamstring group in the leg. Full recruitment or stimulation of the nerve group would be advantageous to long term rehabilitation. Preliminary experiments with the device indicate that excitations at the frequencies mentioned accomplish exercise of the muscles at a higher efficiency and rate than could be accomplished through normal means.
Another area of application is that of assisting in weight loss management. As with muscle rehabilitation, one alternative is to simply use a handheld unit moved over multiple areas of the body. One group which can be particularly difficult to stimulate is the abdominal wall. An alternative method for realizing excitation of this group resembles a chest plate which can be secured to a patient or hinged to the side of a chair in which the patient sits. The chest plate contains a two or three phase arrangement of coils backed by the high field saturation cores constructed in the manner dictated above. The cores are spaced to drive the flux deeply within the abdominal muscle group. Both in muscle rehabilitation and in weight loss management, the phasing of the coils can be alternated with time to give the effect of a back and forth xe2x80x9ckneadingxe2x80x9d stimulation pattern. The rationale behind weight management is that the firing of these muscle groups requires the uptake of adenosine triphosphate; this energy expenditure is being artificially induced by the magnetic stimulator.
In summary, it is noted that there are a number of ways to more efficiently stimulate various muscle groups within the body. The key to these more efficient techniques revolves around using a thin laminate material of high magnetic field saturation to construct these cores and thereby drive and focus the flux into the regions desired. A simple xe2x80x9cCxe2x80x9d type core achieves a reluctance advantage of at least a factor of two over conventional cores. By using multiple cores connected at a center leg, a single focus site can be achieved with the return path disbursed in two or more areas so as to discourage excitation when the field is returned. In other applications, multiphased coils that actually enclose the tissue of interest can be excited so as to roll or knead muscle groups directionally with time. Certain wrapping applications may be more instrumental for higher recruitment of injured muscle groups.


Shipboard wastewater undergoes treatment within an automatic system based on membrane bioreactor technology. Bacteria that are naturally present in the raw waste stream break down during treatment and consume organic material in the wastewater. Membranes in a bioreactor within which the wastewater is treated provide a physical barrier, retaining the bacteria and other solids while producing an effluent sufficiently clean to be discharged directly overboard. To ensure adequate treatment, a flow-through ultraviolet disinfection unit is employed in the system downstream of filtration. Inorganic and other non-biodegradable material that accumulates in the bioreactor with time is removed automatically to maintain the desired solids concentration in the bioreactor. Using selective control established through the operator interface, the system can be operated under automatic process/standby mode or maintenance mode, and sludge concentrate can be directed either overboard, to an onboard storage tank or to undergo further treatment within a concentration device or destruction within an incinerator for example, depending on the ship's equipment, location and operating conditions.

Marine vessels are presently required by Federal Regulations to have certified sanitation devices installed to hold or treat sewage. There are four general types of such sanitation devices categorized as "flow-through and discharge" devices and "non-flow-through" devices. The "flow-through and discharge" devices receive and treat sewage, producing an effluent that meets specified fecal coliform (FC) population and total suspended solids (TSS) limits. The "non-flow-through" devices are designed to collect and hold either sewage only, or a combination of graywater and sewage, depending on the system design, to enable the ship to transit restricted navigable waters. Graywater is defined as wastewater from showers, sinks, laundry, galley and scullery sources. No wastewater treatment is performed in the "non-flow-through" type of systems.
Both commercial and military vessels frequently travel to foreign ports which have discharge regulations that are so restrictive as to establish limits not only for TSS and FC, but also for biochemical oxygen demand (BOD). A reduction of BOD to specified limits can only be achieved through selected methods of treatment. It is therefore an important object of the present invention to provide a system for marine vessels including U.S. Navy ships that will collect and treat both graywater and sewage, producing a clean effluent that satisfies current and anticipated limits for BOD, TSS, and FC.

Marine vessel onboard wastewater treatment system

The United States of America as represented by the Secretary of the Navy


Provided are a method, system, and program for generating threshold values in a dither matrix. A dither matrix of threshold values is generated. The threshold values in the dither matrix are filtered to generate a filtered dither matrix of filtered dither values by performing for dither values in the dither matrix: determining a region of dither values in the dither matrix that surrounds the value being considered, wherein the dither values in the determined region comprise one of dither values in a first portion of the region within the dither matrix or a wrap around dither value in a second portion of the region that extends beyond the dither matrix; and using an offset value to determine one wrap around dither value, wherein repeated instances of the dither matrix are designed to be applied to an image by forming a tile pattern of the repeated instances of the matrix over the image pattern, and wherein the repeated instances of the matrix in the tile pattern are offset in one direction by the offset value; and performing an operation on the determined dither values in the region to determine a filtered value for the dither value being considered.

1. Field of the Invention
The present invention relates to a method, system, and program for generating threshold values in a dither matrix.
2. Description of the Related Art
Most printers today can print in only a limited number of colors. Digital halftoning is a technique for printing a picture (or more generally displaying it on some two-dimensional medium) using small dots of a limited number of colors such that it appears to consist of many colors or shades of grey when viewed from a proper distance. For example, a picture of black and white dots can appear to display grey levels when viewed from some distance.
A popular method for digital halftoning is accomplished using a dithering algorithm which generates a dither mask or array having threshold values. The pixel values in the image comprise one of many greyscale or color values. Each pixel value is compared to a corresponding threshold value in the dither mask to determine whether the halftone output for that pixel is "on" (i.e. a dot will be printed at that pixel, and this can be represented numerically as the halftone pixel having a value 1) or "off" (i.e. a dot will not be printed at that pixel, represented numerically as the halftone pixel with value 0). Dither arrays use periodic patterns of threshold values which can have an unpleasant rendering at certain gray levels.
Too much randomness in the design of a dither array blurs the image and yields unaesthetic results. Techniques have been developed to increase the effect of blue noise with low frequencies attenuated to improve the visual effect of the image, such as that described in U.S. Pat. Ser. No. 5,726,772. In halftoning, blue noise is the statistical model describing the ideal spatial and spectral characteristics of aperiodic dispersed-dot dither patterns to attempt to produce stochastic dither patterns of the same-sized dots distributed as homogeneously as possible. Stochastic or blue noise patterns have also been used to improve clustered periodic dither mask as described in U.S. Pat. Ser. No. 6,025,930.
A step in typical methods to generate a dither mask that increases the desirable effect of blue noise is the filtering operation, where the values in the dither mask or a halftone pattern obtained from a dither mask may be filtered, such that each pixel value in the array is calculated as a weighed average of values that surround the subject pixel value, as described in C. W. Wu, G. Thompson, M. Stanich, "A unified framework for digital halftoning and dither mask construction: variations on a theme and implementation issues (Focal Paper)," NIP 19: IS&T's International Conference on Digital Printing Technologies, New Orleans, La., 2003, pp. 793-796. As described in this paper, many algorithms for generating dither masks have this filtering operation in common. The rest of the algorithm can be different depending on the algorithm and the application. Since the image to be halftoned is generally much larger than the dither mask, FIG. 1 illustrates how, in the prior art, repeated instances of a dithering mask 2a, 2b, 2c, 2d are arranged in a tile pattern superimposed over an image to provide threshold values for the pixel values in the image to determine the output for the pixel values in the image. A filter region 4 is used to determine surrounding threshold values to a center pixel value, e.g., "88" in mask 2a that falls within the filter region 4, such that a weighted average of the surrounding values of "88" as defined in the filter region 4 are calculated to produce filtered threshold values for a filtered dither mask. If the filter region 4 extends beyond the mask 2a including the threshold pixel whose filtered value being calculated, then the threshold value outside of the region of the matrix wraps around to the other side of the matrix. For instance, the surrounding value in the filter region 4 below the cell having value "97" wraps around to the other side to provide the threshold value "17", which I shown in the instance of the dither mask 2c. These surrounding values in the portion of the filter region 4 that extend beyond the mask 2a are referred to as "wrap around values".
In prior art methods for generating stochastic or blue noise masks, the dither mask is tiled as shown in FIG. 1, i.e. the dither masks are arranged with the edges aligned with each other. This condition is especially necessary in implementations where a Fourier transform based method is used to perform the filtering or convolution operation. In this case, the wrap around corresponds to circular convolution which can be easily implemented in a computer algorithm using the Fast Fourier Transform.
There is a need in the art for improved techniques for generating and filtering dither masks to improve the visual effects of a printed or displayed image.

Generating threshold values in a dither matrix


In a window-integrated antenna in vehicles, the heating conductor field (3,4) is used for FM reception as well as for LMS reception. At least one decoupling element (6) is provided for LMS reception which has a high-frequency, but non-galvanic connection to the heating conductor field (3,4). The decoupling element (6) is situated in the heating conductor field, in particular between two adjacent heating conductors (3).

The heating field of the window is frequently used in vehicle antennas as the antenna structure. The heating field is provided for both FM and TV reception in U.S. Pat. No. 6,498,588 and in PCT Published International Application No. 99/66587. A conductor loop, which is not connected to the heating field, is additionally provided for LMS (long, medium, short wave) reception on the upper edge of the window.
A significant disadvantage of such a system is the necessity of a surface, e.g., in the upper area of the window, which, due to non-existing heating conductors, cannot be heated and therefore cannot be defrosted. The available heatable area is unacceptably small, particularly in passenger cars having small windows.
The heating conductors run essentially horizontally and essentially parallel to the metallic boundaries of the window. Interference in the vehicle electrical system, transferred by the heating current to the heating conductors acting as the antenna, must, as is known, be suppressed via modules having a high-resistance behavior at high frequencies when the antenna connection point is galvanically linked to the heating field. For FM reception, these modules are one core double chokes, for example, which are integrated into the heating current-supplying conductor segments and, as a rule, are situated at the heating current terminals of the heating field.
For LMS reception, this is a current-compensated toroidal core choke (AM blocking circuit) which is also situated in the heating current supply lead. This AM blocking circuit is a very cost-intensive module whose dead weight of approximately 200 g results in high mechanical stresses on the printed circuit board as well as the union points, and is thus to be valued extremely critical with respect to quality assurance. The vibrations, occurring during normal driving conditions, result in the fact that soldered joints are extremely stressed. In compact vehicles, this AM blocking circuit is frequently mounted in the tailgate, so that accelerations of approximately 50 g may occur when the tailgate is slammed shut and the module breaks off the union points.
In other vehicle antenna reception systems, the reception of LMS and diverse FM signals is implemented via conductor structures in one or multiple window panes which are for the most part situated in the immediate proximity of, but spatially separated from, one another. A significant disadvantage in such a system is the necessity of at least two, for the most part fixed, window panes which results in increased expenses for the manufacture of the panes, for the electronic design of connected, for the most part active circuit components, and for the assembly of appropriate circuit carriers.
Antenna systems are also known which form the antennas for LMS and FM reception from the galvanically contacted heating field. Here also, filter elements, which decouple the vehicle electrical system, are necessary for the antenna connection point and the heating conductor (European Published Patent Application No. 0 269 723 and European Published Patent Application No. 0 382 895).


The stability of attitude of a robot can be recovered by an ambulation control apparatus and an ambulation control method according to the invention if it is lost in the course of a gesture for which the upper limbs take a major role. The apparatus and the method obtain the pattern of movement of the entire body for walking by deriving the pattern of movement of the loins from an arbitrarily selected pattern of movement of the feet, the trajectory of the ZMP, the pattern of movement of the trunk and that of the upper limbs. Therefore, according to the invention, a robot can determine the gait of the lower limbs so as to realize a stable walk regardless if the robot is standing upright or walking. Particularly, if the robot is made to gesture, using the upper body half including the upper limbs and the trunk while standing upright, it can determine the gait of the lower limbs so as to make a stable walk in response to such a gait of the upper body half.

1. Field of the Invention
This invention relates to an ambulation control apparatus and an ambulation control method to be used for a robot having a structure adapted to behave like a living body with an enhanced level of reality. More particularly, the present invention relates to an ambulation control apparatus and an ambulation control method to be used for a bipedal ambulatory robot having a structure that mimics the bodily mechanism and the motion of an erect bipedal animal such as man or ape.
To be more accurate, the present invention relates to an ambulation control apparatus and an ambulation control method to be used for a bipedal ambulatory robot adapted to erect bipedalism and having the upper half of the body including the torso, the head and the arms mounted on the lower limbs. More particularly, it relates to an ambulation control apparatus and an ambulation control method to be used for a robot that mimics the motion of man including gestures with startling reality and walks on its two legs without losing balance.
2. Description of Related Art
A robot refers to a mechanical apparatus that moves like man, utilizing electric and/or magnetic effects. The word "robot" is believed to be originating from a Slavic word "ROBOTA (slave machine)". Robots became popular in Japan in the late nineteen sixties but many of them were industrial robots designed for the purpose of automation and manpower-saving in factories including manipulators and carrier robots.
As a result of massive research and development efforts in recent years in the field of bipedal ambulatory robots having a structure that resembles the bodily mechanism and the motion of an erect bipedal animal such as man or ape, robots are expected than ever to find practical applications. The bipedal ambulatory robot adapted to erect bipedalism has an advantage that it can softly walk, getting over an obstacle and stepping up and down a staircase without difficulty.
It should be noted here, however, that the research and development of bipedal ambulatory robot historically started from studies on various aspects of motion of lower limbs and was not directed to entire erect bipeds.
For instance, Japanese Patent Application Laid-Open No. 3-184782 discloses a joint applicable to a structure corresponding to from-the-torso-down of a bipedal ambulatory robot.
Japanese Patent Application Laid-Open No. 5-305579 discloses an ambulation control apparatus of a bipedal ambulatory robot. An ambulation control apparatus according to the above patent document is adapted to control a bipedal ambulatory robot in such a way that the ZMP (zero moment point) of the robot on the floor where the robot is walking agrees with a target position. The zero moment point is a point on the floor where the moment of the robot due to the reaction of the floor is equal to nil. However, it is clear from FIG. 1 of the above patent document that the torso 24 that gives rise to the moment is a sort of black box and the document proposes only lower limbs of a bipedal ambulatory robot and not an entire robot that mimics man.
However, to many researchers, obviously the ultimate object of research and development of bipedal ambulatory robots is realization of a structure that looks like and moves like man. To be more accurate, a bipedal ambulatory robot is a structure adapted to erect bipedalims and having lower limbs good for walking on its two feet, an upper half of the body including a torso, a head and arms (hereinafter to be referred to simply as upper limbs) and a trunk section linking the upper limbs and the lower limbs. A complete robot should be so controlled that it stands upright and walks and works on its two feet, moving the upper limbs, the lower limbs and the trunk section in a coordinated manner according to a predetermined priority scheme.
A bipedal ambulatory robot that simulates man in terms of motion and bodily structure is referred to as humanoid robot. A humanoid robot can support our daily lives in various scenes of living.
Bipedal ambulatory robots can be roughly categorized into those to be used for industry and those to be used for entertainment.
Robots for industrial applications are mostly designed to replace men in various different industrial scenes and do difficult works for men in the field of manufacturing, construction, power generation and so on. For example, robots of this category replace men in atomic power plants, thermal power plants, petrochemical plants and other plants for maintenance works and in manufacturing factories and sky-scraping buildings for various dangerous and difficult works. Thus, robots of this category are so designed and manufactured as to operate for a specific application or function in a specific way, although they walk on two feet. In other words, they are not required to have a structure that mimics the bodily mechanism and the motion of an erect bipedal animal such as man or ape. For instance, while they may show high degrees of freedom at a specific part of the body in order to work for a specific application by moving in a delicate way, the degrees of freedom of other parts of the body that are not directly related to the application such as head and waist may be left low. As a result, inevitably, such robots may move awkwardly and may not appear particularly agreeable.
On the other hand, robots for entertainment are more closely related to our daily lives rather than adapted to carry out difficult works and supporting our lives. In other words, robots of this category are designed to copy the physical mechanism of erect bipedalism of men and apes and move smoothly. As they are a sort of copies of erect mammals such as men and apes who are highly intelligent, they are preferably rich in expressions. In this sense, they are exactly humanoid robots.
In short, while robots for entertainment share the essential technologies with those for industrial applications, they are totally different from each other in terms of hardware mechanism, method of controlling motions and software configuration for achieving the ultimate object.
As well known, the human body has joints whose number exceeds several hundreds and hence shows several hundred degrees of freedom. While a robot preferably shows the same degrees of freedom if it mimics perfectly the behaviour of man, to achieve such high degrees of freedom is technologically highly difficult because a single degree of freedom requires the use of an actuator but a robot provided with hundreds of actuators is totally impractical in terms of manufacturing cost, weight and size. Additionally, a robot with high degrees of freedom requires a volume of computation that increases exponentially for controlling the position, action and balance.
To summarize, a humanoid robot has to be designed to emulate the bodily mechanism of man with limited degrees of freedom. Additionally, a robot for entertainment is required to behave like man and be rich in expressions with degrees of freedom far lower than the human body.
Additionally, while a bipedal ambulatory robot adapted to erect bipedalism can softly walk, getting over an obstacle and stepping up and down a staircase without difficulty, the operation of controlling its attitude and walk is difficult because its center of gravity is rather high. Particularly, a robot for entertainment should be so controlled for its attitude and stable walk that it remains rich in expressions.
Meanwhile, the "expression" of man or ape heavily relies on the motion of the upper limbs including the arms and the torso in terms of not only carrying out a work but also manifesting its feeling. Such a motion is referred to as "gesture".
In our daily lives, gestures appear almost constantly on our bodies while we are standing or walking or otherwise moving on our feet. Additionally, the center of gravity the entire body of a person moves significantly to give rise to the moment of inertia while he or she is gesturing. Men and apes are so created that they can keep on standing or walking by autonomously compensating the balance of the center of gravity and the moment of inertia.
On the other hand, a humanoid robot is required to be rich in expressions as pointed out above and hence gestures are indispensable to it. Therefore, the robot needs attitude control and stable walk control in response to a gesture for which the upper half of the body takes a major role.
A number of techniques have been proposed for controlling a bipedal ambulatory robot in terms of attitude and stable walk. However, most of the known techniques are those adapted to make the ZMP (zero moment point) of the robot where the moment of the robot due to the reaction of the floor is equal to nil agrees with a target position.
For example, Japanese Patent Application Laid-Open No. 5-305579 discloses a bipedal ambulatory robot that is controlled in such a way that the ZMP of the robot on the floor where the robot is walking agrees with a target position.
Additionally, the bipedal ambulatory robot of Japanese Patent Application Laid-Open No. 5-305581 is so configured that the ZMP is located in the inside of the supporting polyhedron or at a position separated from the ends of the supporting polyhedron of the robot by a predetermined margin when one of the feet of the robot touches down on or lifts off from the floor. With this arrangement, the robot can maintain its stability of walking if subjected to external disturbances because of its safety margin of a predetermined distance.
Japanese Patent Application Laid-Open No. 5-305583 also discloses a technique of controlling the walking speed of the bipedal ambulatory robot by way of ZMP target position. More specifically, the bipedal ambulatory robot of the above patent document uses preselected walk pattern data and the leg joints of the robot are so driven as to make the ZMP agree with a target position, while the inclination of the upper half of the body is detected, so that the rate of delivering the preselected walk pattern data is modified according to the detected value of inclination. As a result, if the robot rides on unexpected undulations of the floor and becomes forwardly inclined, the rate of delivering the preselected walk pattern data is raised to allow the robot to restore the proper attitude. Additionally, since the ZMP is so controlled as to agree with a target position, there arises no problem if the rate of delivering the preselected walk pattern data is modified when the robot is standing on its two feet.
Still additionally, the Japanese Patent Application Laid-Open No. 5-305585 discloses a technique of controlling the touch down position of either of the two feet of the bipedal ambulatory robot according to the target position of the ZMP. More specifically, the bipedal ambulatory robot of the above patent document either detects the discrepancy between the target position and the actually detected position of the ZMP and drives one or both of the legs to eliminate the discrepancy or detects the moment around the ZMP target position and drives the legs so as to make the detected moment equal to zero.
Furthermore, the Japanese Patent Application Laid-Open No. 5-305586 describes a technique of controlling the inclined attitude of the bipedal ambulatory robot by way of the ZMP target position. More specifically, the bipedal ambulatory robot of the above patent document detects the moment around the ZMP target position and, if any moment is detected, it drives the legs so as to make the detected moment equal to zero for stable walk.
Besides, known documents including "The Data Book of Bipedal Ambulatory Robots", (2nd edition), A General Study (A) Subsidized by the Ministry of Education, "A Study on Ambulation and Control of a Bipedal Ambulatory Robot", Research Group (February, 1986) and "The Development of a Bipedal Ambulatory Robot Adapted to Compensate the Tri-Axial Moment by a Motion of the Upper Limbs" (6th Symposium on Intelligent Moving Robots, May 21 and 22, 1992) describe bipedal ambulatory robots comprising at least upper limb joints for driving the upper limbs and a plurality of leg joints linked to the upper limbs and adapted to drive the leg joints for walking, wherein the gait of the upper limbs is determined on the basis of that of the lower limbs (and hence any instability of the attitude of the robot due to the motion of the legs is corrected by the gait of the upper limbs).
Thus, the above pointed out known techniques are not adapted to control the attitude and the stability of walking of the robot by taking motions where the upper limbs of the robot takes a major role into consideration. In other words, the above techniques are for recovering the stability of walking of a bipedal ambulatory robot by modifying the attitude of its upper limbs (and their motion that changes with time) when the robot can no longer keep on walking due to external disturbance. Differently stated, those techniques are intended to modify the attitude of the upper limbs of a robot where the lower limbs takes a major role in walking in order to correct their instability due to external disturbances so that the techniques neglect the expression of the upper limbs. Additionally, the techniques described in the above documents cannot recover the stability of attitude if it is lost in the course of a gesture for which the upper limbs take a major role.
In view of the above pointed out technological problems, it is therefore an object of the present invention to provide an ambulation control apparatus and an ambulation control method for effectively controlling a robot having a structure that is adapted to mimic the mechanism and the behaviour of a living body.
Another object of the present invention is to provide an ambulation control apparatus and an ambulation control method for effectively controlling a bipedal ambulatory robot having a structure that is adapted to mimic the mechanism and the behaviour of an erect biped such as man or ape.
Still another object of the present invention is to provide an ambulation control apparatus and an ambulation control method for effectively controlling an erect bipedal ambulatory robot having lower limbs adapted to erect bipedalism and amounted with an upper body half including a torso, a head and arms.
Still another object of the present invention is to provide an ambulation control apparatus and an ambulation control method for effectively controlling a robot so as to make it walk stably and keep on behaving like a man and being rich in expressions.
A further object of the present invention is to provide an ambulation control apparatus and an ambulation control method for effectively controlling an erect bipedal ambulatory robot having lower limbs adapted to erect bipedalism and amounted with an upper body half including a torso, a head and arms so as to make it recover the stability of attitude whenever the latter is lost due to an action of gesture or some other expression where the upper body half takes a major role.
A still further object of the present invention is to provide an ambulation control apparatus and an ambulation control method for effectively controlling an erect bipedal ambulatory robot so as to make it determine its gait of the lower limbs in response to that of the upper limbs (the term "gait" as used herein is a technical term of the industry referring to "time series changes of the angles of joints" and having a meaning substantially same as "pattern of movement").

Ambulation control apparatus and ambulation control method of robot


To eliminate uneven luminance between columns, and along with this, to eliminate uneven luminance also among EL elements in several columns in an EL display device for performing matrix display, in a matrix type EL display device in which a scan voltage is sequentially applied to scan electrodes and EL elements are caused to electroluminesce by this scan voltage and a data voltage, a pulse width of the scan voltage is kept uniform, and together with this, a charging period for the EL elements is varied in accordance with a number of light emitting pixels in a line scanned and driven to eliminate uneven luminance between columns. Additionally, a holding period for holding a charging voltage is provided to alleviate differences in terminal voltages among the EL elements due to wiring resistance delay and to eliminate uneven luminance among the EL elements.

1. Field of the Invention
This invention relates to an EL display device which drives an EL element to emit light.
2. Description of Related Art
Various devices which have a plurality of scan electrodes and a plurality of data electrodes arranged in a matrix to perform display with an EL element of this type have previously been proposed. In such a matrix type display device, there is a problem where uneven luminance between columns occurs due to fluctuation in a number of pixels caused to emit light per column. The device disclosed in Japanese Unexamined Patent Publication No. Hei 7-48137 attempts to eliminate such uneven luminance by changing the pulse width of scan voltage.
However, because wiring resistance exists in scan electrodes, for the terminal voltage of the several pixels of a scan electrode, the predetermined voltage comes to be applied increasingly less as the pixel is located increasingly farther from the scan electrode terminal due to delay by wiring resistance. Because of this, even when pulse width of the scan voltage applied to the scan electrodes is controlled, as in the device described in the foregoing Japanese Unexamined Patent Publication No. Hei 7-48137, uneven luminance due to fluctuation in terminal voltage among pixels in several columns still cannot be eliminated. Delay due to wiring resistance exists even when aluminum is employed as the electrode material, and is even greater in the case of a transparent electrode composed of ITO, ZnO, or the like.
Further, to eliminate uneven luminance in each of several scan lines, the system described in Japanese Unexamined Patent Publication No. 7-48137 varies a scan signal period in accordance with a number of light-emitting pixels. This is done by controlling on and off states of switches in scan-side power supply circuits in that device to control the voltage supplied to scan-side transistors. In this case, voltages of 0 and 190 V are alternatingly applied on the line (hereinafter termed "power-supply line") connecting one of the switches to the scan-side transistors. Here, referring to "H" in FIG. 6 of Japanese Unexamined Patent Publication No. 7-48137, the time between the scan-side line (PT1) and the scan-side line (PT3) is 80 .mu.s (see PSC in the drawing), and so the cycle in which 0 V and 190 V are alternated is 12.5 kHz. When high voltage alternate in a short cycle, noise is generated, and there is a problem of interference with peripheral circuitry.

Electroluminescent display device having uniform display element column luminosity


A map provider and a data location provider provide information as to how the data pertaining to entities is stored in a database system and where the data is stored in the database system. A data accessing system uses the information to process requests to perform an operation on the data.

The present invention relates to database systems.
In conventional relational databases, all data are stored in named tables. The tables are described by their features. In other words, the rows of each table contain items of identical type, and the definitions of the columns of the table (i.e., the column names and the data types stored in the column) describe the attributes of each of the instances of the object. By identifying its name, its column names and the data types of the column contents, a table is completely described. Queries to a relational database are formulated in a query language. One such language is SQL (Structure Query Language) which is widely used in commercial relational database systems. The data types offered by SQL can be classified as character arrays (names), numbers, and data types related to date and time. Tables can be modified or combined by several operations of relational algebra such as the application of Boolean operators, projection (i.e. selection of columns) or the Cartesian product.
Relational databases offer several advantages. Database queries are based on a comparison of the table contents. Thus, no pointers are required in relational databases, and all relations are treated uniformly. Further, the tables are independent (they are not related by pointers), so it is easier to maintain dynamic data sets. The tables are easily expandable by simply adding new columns. Also, it is relatively easy to create user-specific views from relational databases.
There are, however, a number of disadvantages associated with relational databases as well. For example, access to data by reference to properties is not optimal in the classical relational data model. This can make such databases cumbersome in many applications.
Another recent technology for database systems is referred to as object oriented database systems. These systems offer more complex data types in order to overcome the restrictions of conventional relational databases. In the context of object oriented database models, an "object" includes both data and the functions (or methods) which can be applied to the object. Each object is a concrete instance of an object class defining the attributes and methods of all its instances. Each instance has its unique identifier by which it can be referred to in the database.
Object oriented databases operate under a number of principles. One such principle is referred to as inheritance. Inheritance means that new object classes can be derived from another class. The new classes inherit the attributes and methods of the other class (the super-class) and offer additional attributes and operations. An instance of the derived class is also an instance of the super-class. Therefore, the relation between a derived class and its super-class is referred to as the "isA" relation.
A second principle related to object oriented databases is referred to as "aggregation." Aggregation means that composite objects may be constructed as consisting of a set of elementary objects. A "container object" can communicate with the objects contained therein by their methods of the contained objects. The relation between the container object and its components is called a "partOf" relation because a component is a part of the container object.
Yet another principle related to object oriented databases is referred to as encapsulation. According to encapsulation, an application can only communicate with an object through messages. The operations provided by an object define the set of messages which can be understood by the object. No other operations can be applied to the object.
Another principle related to object oriented databases is referred to as polymorphism. Polymorphism means that derived classes may re-define methods of their super-classes.
Objects present a variety of advantages. For example, operations are an important part of objects. Because the implementations of the operations are hidden to an application, objects can be more easily used by application programs. Further, an object class can be provided as an abstract description for a wide variety of actual objects, and new classes can be derived from the base class. Thus, if an application knows the abstract description and using only the methods provided by, the application can still accommodate objects of the derived classes, because the objects in the derived classes inherit these methods. However, object oriented databases are not yet as widely used in commercial products as relational databases.
Yet another database technology attempts to combine the advantages of the wide acceptance of relational databases and the benefits of the object oriented paradigm. This technology is referred to as object-relational database systems. These databases employ a data model that attempts to add object oriented characteristics to tables. All persistent (database) information is still in tables, but some of the tabular entries can have richer data structure. These data structures are referred to as abstract data types (ADTs). An ADT is a data type that is constructed by combining basic alphanumeric data types. The support for abstract data types presents certain advantages. For example, the methods associated with the new data type can be used to index, store, and retrieve records based on the content of the new data type.
Some conventional object-relational databases support an extended form of SQL, sometimes referred to as ObjectSQL. The extensions are provided to support the object model (e.g., queries involving object attributes). However, these object-relational databases are still relational because the data is stored in tables of rows and columns, and SQL, with some extensions, is the language for data definition, manipulation, and query. Both the target of a query and the result of a query are still tables. The extended SQL language is often still the primary interface to the database. Therefore, there is no direct support of host object languages and their objects. This forces programmers to continue to translate between objects and tables.
Data pertaining to the operation of a business such as types of companies forming an enterprise, orders that the company receives from various customers, and what constitutes an order is hierarchical. As discussed above, relational systems for storing data, on the other hand, are tabular in nature, and consequently, do not directly represent hierarchies. Accordingly, object programming models do not represent the hierarchy of business data very well.


A method for monitoring operation of a plant via a plurality of sensors includes: a) determining respective temporal waveforms of measurement values recordable with the sensors during normal operation of the plant, b) determining dependencies between the determined temporal waveforms of the measurement values, c) recording respective temporal waveforms of measurement values with the sensors during the operating mode to be monitored of the plant, and d) deciding whether a fault is present in the operating mode to be monitored of the plant by evaluating the recorded temporal waveforms on the basis of the determined dependencies.

The disclosure relates to a method and an arrangement for monitoring an operation of a plant, in particular an industrial production plant.
In order to monitor industrial plants, it is known to measure a wide range of parameters, such as a temperature. If, for example, a measured parameter exceeds a set limit value, the plant can be automatically shut down to protect against damage. In such monitoring processes, however, it is often difficult to reliably distinguish between critical situations in which, for example, a shutdown is necessary, and non-critical situations in which no action is required.
On this basis, the object of the disclosure is to solve, or at least reduce, the technical problems described in connection with the technology of the prior art. In particular, a method and an arrangement for monitoring operation of a plant will be presented, which can be used to distinguish between critical and non-critical situations particularly reliably.

Method and arrangement for monitoring an operation of a plant


A wireless handheld device is disclosed that includes a device housing, a wireless transmitter, such as a short range wireless transmitter, a local display and a housing motion detector that is operative to detect motion of the housing, for example, relative to a surface or other reference point, and outputs graphic user interface control information for transmission by the wireless transmitter to an external device. In one embodiment, a wireless pointing device is operably coupled with a wireless handheld device such as a cell phone or any other suitable wireless handheld device that includes a short range wireless transmitter and/or transceiver to remotely control operation of a graphic user interface for an external device. The housing motion detector utilizes the battery power of the wireless handheld device as its sole source of power or as an auxiliary source of power.

Wireless mice are known which employ, for example, an optical or infrared sensor that senses movement of the wireless mouse on a surface, such as a table, and wirelessly communicates pointing device control information such as cursor location information or menu selection information to a short range wireless receiver in a laptop device or other device. Such wireless mice provide many advantages but can run out of battery power. The device may then be recharged through a USB port with the laptop device or through an AC wall socket or other suitable power source.
Wireless handheld devices such as cell phones and cell phones combined with other functions such as email and Internet access are also known (such as the Blackberry® type device or other suitable devices). Such devices employ a display for displaying information to a user and also employ a pointing device such as a mouse or track wheel which is used to control a graphic user interface such as controlling cursor movement and/or menu selection on a local display. Such devices may employ a pointing device such as a touch pad, tracking wheel, or other conventional mouse that detects the movement of a user's finger relative to a touch pad or movement of a tracking wheel relative to a fixed point in the housing of the handheld device. However, such local pointing devices do not typically control a GUI on a remote device.
It would be desirable to have a wireless pointing device that would couple with or be integrated with a wireless handheld device to receive additional battery power for the wireless pointing device and/or to provide GUI control of an external device to the handheld device.

Wireless handheld device and method with remote GUI control


A method for forming a liquid crystal display incorporating a first substrate having switching elements and electrodes connected to the elements, a second substrate, a sealing member, and a liquid crystal material wherein during manufacturing the electrodes are grounded to the device for forming the sealing member and then the sealing member is formed on the first substrate.

1. Field of the Invention
This invention relates to a liquid crystal display and more particularly to injecting liquid crystal material and sealing while preventing damage to transistors, etc. from static electricity in an active matrix type liquid crystal display.
2. Description of the Prior Art
For the past several years, liquid crystal displays have been growing in use, for example, in word processors, televisions, etc., as a display means suitable for smaller size and lighter weight devices.
Recently, the display in these instruments has a great demand for larger picture and higher picture quality, and demands for commercialization of the active matrix type liquid crystal display, in which a larger area and higher density are possible are increasing.
However, since such active matrix type liquid crystal displays of larger area and higher density are being researched and developed based on the conventional small-sized low-density liquid crystal display, various problems are caused by these differences.
Problems in manufacturing are shown below as examples.
FIG. 8 is a manufacturing process diagram of the prior art of a liquid crystal cell of a conventional active matrix type liquid crystal display. A manufacturing process will be described with reference to FIG. 8 which shows steps a through m.
First, in step a, two glass substrates for composing the active matrix liquid crystal display are washed.
Then, in step b, a molecule-orienting film is formed on each of the glass substrates, and in step c, an orientation treatment such as a rubbing method is applied on the surfaces.
Then, in steps d and e, a gap potion and a sealing portion to seal liquid crystal material and formed, and in step f, a glass substrate with an electrode provided for every picture element thereof, and a glass substrate provided with a transparent electrode on one surface, are connected through a common electrode.
These two glass substrates are stacked together, in step g, and in step h are heated and pressurized under specified conditions to harden the sealing portion.
FIG. 9 shows a half-finished product which has been processed through such steps a to h.
In FIG. 9, 1 designates a glass substrate with many electrodes 2 formed vertically and horizontally, and 3 designates a glass substrate with a transparent electrode formed thereon. Reference numeral 4 represents a sealing section and 5 represents a shorting ring. The shorting ring 5 shorts signal portions and gate portions of switching transistors formed on the glass substrate 1 to prevent the switching transistors from being damped by static electricity produced in each of the above manufacturing steps.
As shown by broken lines in FIG. 10, the shorting ring 5 connected to an outer edge portion of the glass substrate 1 is cut off together with the outer edge portion of the glass substrate 1 itself. This step is called a scribing step and is shown as step i in FIG. 8.
Then, as shown in FIG. 11, glass substrate 1 and 3 are placed nearly perpendicularly to the liquid crystal surface in a boat 7, where a liquid crystal material 6 accumulates. Liquid crystal injection port 8, provided at the corner of the glass substrates 1 and 3 stacked together, is immersed to inject the liquid crystal material into the space between the glass substrates 1, 3 as shown as step j in FIG. 8.
After the liquid injection port 8 has been sealed in step k, this part is washed shown in FIG. 8 as step 1, and finally a polarizer is attached as shown in FIG. 8, step m.
In such a manufacturing process, shorting ring 5 is intentionally used to prevent the switching transistors from being damaged due to the static electricity. However, before injection of the liquid crystal material, it is necessary, for facilitating the immersion of the substrate into the boat 7 by decreasing the area of glass substrate 1 and for removing the corner section of the glass substrate which is heavily stained, to scribe the glass substrate in the position where the shorting ring is connected. That is, in the steps after scribing step i, the shorting ring is removed and the signal portions and the gate portion of the switching transistors become insulated. For this reason, in the steps thereafter (step (j) and after), if static electricity is produced, the switching transistors can be damaged. For example, a polarizer has a protective film attached to its surface before being attached to the substrate, but the protective film 9, shown in FIG. 12, must be peeled off after the polarizer has been attached in step m of FIG. 8. This can produce a large quantity of static electricity which may cause the switching transistors to be defective. In such a manufacturing process, in step j the liquid crystal material is injected by a so-called perpendicular method. Because when liquid crystal injection port 8 is immersed, not only liquid crystal injection port 8, but also the whole corner section of glass substrates 1 and 3 around port 8 are immersed, the oil, dust, etc. attached to the corner section of glass substrates 1 and 3 are dissolved in the liquid crystal material accumulated in boat 7, and liquid crystal material 6 becomes gradually contaminated and deteriorates with use. Therefore liquid crystal material 6 must be replaced after being used to some degree. In addition, since the whole corner section of glass substrates 1 and 3 is immersed in liquid crystal material 6, some part of liquid crystal material 6, instead of being injected into the space between the glass substrates through liquid crystal injection port 8, sticks to the surface of the corner section of glass substrates 1 and 3. Thus, in such a manufacturing process, a large quantity of liquid crystal material 6 is lost by contamination, deterioration, or sticking to useless portions of glass substrates 1 and 3.
Manufacturing such a large-area and high-density active matrix type liquid crystal display by the conventional method produces static electricity that can damage the switching transistors. In addition, there is a problem of a large quantity of liquid crystal material being lost uselessly by contamination and deterioration or sticking to the useless sections.

Method for forming a liquid crystal display with a sealing member

International Business Machines Corporation


A fluid-filled vibration damping device wherein two mutually spaced-apart mounting members are connected by an elastic body, which cooperate with an elastic wall member to partially define a pressure-receiving chamber, and a flexible diaphragm partially defines an equilibrium chamber on one side and a working air chamber on the other side. These chambers are filled with the non-compressible fluid and held in fluid communication with each other through the orifice passage. A negative pressure-regulating device applies different negative pressure to the working air chamber depending upon frequencies of vibration to be damped, so that a spring constant of the elastic wall member is changed corresponding to the vibration to be damped, thereby controlling a damping characteristics of the damping device.

The disclosure of Japanese Patent Application No. 2000-214108 filed on Jul. 14, 2000 including the specification, drawings and abstract is incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates in general to a fluid-filled vibration-damping device, which exhibits a vibration damping or isolating effect based on flows or resonance of a non-compressible fluid contained therein. More particularly, the present invention is concerned with a novel fluid-filled vibration damping device which has a plurality of orifice passages tuned to respective different frequency bands of input vibrations and exhibits an excellent vibration damping effect with respect to the input vibrations having different frequencies or over a wide frequency range, based on the flows of the non-compressible fluid through these orifice passages.
2. Discussion of the Related Art
As one type of a vibration damper interposed between two members of a vibration system so as to connect these two members in a vibration damping manner or mount one of these members on the other member in a vibration damping manner, there is known, as disclosed in JP-U-61-190051, for example, a fluid-filled vibration damping device which includes: a first and a second mounting member that are disposed in mutually spaced-apart relationship with each other; an elastic body elastically connecting the first and second mounting members and partially defining a pressure-receiving chamber filled with a non-compressible fluid; and an easily deformable flexible diaphragm partially defining an equilibrium chamber filled with the non-compressible fluid and held in fluid communication with the pressure-receiving chamber through a first orifice passage. Such a known fluid-filled vibration-damping device is capable of exhibiting an excellent vibration damping effect based on resonance of the fluid flowing through the first orifice passage, which effect would not be achieved by only the elasticity of the elastic body. Therefore, the fluid-filled vibration-damping device is preferably usable as an engine mount for an automotive vehicle, for example.
Generally, the vibration damping or isolating effect of the known fluid-filled vibration damping device based on the flows or resonance of the fluid is exhibited with respect to only the particular input vibrations over a limited frequency range to which the first orifice passage is tuned. In particular, when the frequency of the input vibration is higher than the frequency band to which the first orifice passage is tuned, a resistance to flow of the fluid through the first orifice passage tends to be increased, making it difficult for the device to exhibit a satisfactory damping effect based on the fluid flows through the first orifice passage. In this case, the fluid-filled vibration-damping device exhibits a high dynamic spring constant, resulting in significant deterioration of the vibration damping characteristics.
To cope with this drawback, there is proposed another structure of the fluid-filled vibration damping device wherein the pressure-receiving chamber is partially defined by an elastically displaceable elastic wall member, as disclosed in JP-A-2-129427, for example. In this structure, the elastic wall member is displaced at a suitable frequency so that a periodic pressure change generated in the pressure-receiving chamber upon application of the higher frequency vibrations is reduced or absorbed, for preventing or minimizing an excessive increase in the dynamic spring constant of the device. There is also proposed yet another structure, as disclosed in JP-A-7-71506, wherein a partition member is disposed within the pressure-receiving chamber so as to divide the pressure-receiving chamber into two sections, namely a primary fluid chamber partially defined by the elastic body and a auxiliary fluid chamber partially defined by the elastic wall member, and a second orifice passage is formed for fluid communication between the primary and auxiliary fluid chambers. In this structure, the vibration damping device exhibits a low dynamic spring constant and an accordingly high vibration isolating effect based on flows of the fluid through the second orifice passage, upon application of high-frequency vibrations.
However, even in the provision of the elastic wall member or the second orifice passage, as described above, the fluid-filled vibration damping device still suffers from significant increase in the dynamic spring constant when the frequency of the input vibration is higher than the frequency band to which the elastic wall member or the second orifice passage is tuned, resulting in significant deterioration of the vibration damping characteristics of the device with respect to the higher frequency vibrations. Thus, the known fluid-filled vibration damping device suffers from significant difficulty in exhibiting an excellent vibration damping or isolating effect with respect to the input vibrations over a sufficiently wide frequency range.
It is therefore an object of the present invention to provide a fluid-filled vibration damping device which is novel in construction and which is capable of exhibiting an excellent vibration damping or isolating effect based on flows or resonance of a non-compressible fluid contained therein, with respect to input vibrations over a sufficiently wide frequency range.
The above and other objects of this invention may be attained according to the following modes of the invention. Each of these modes of the invention is numbered like the appended claims and depends from the other mode or modes, where appropriate, to indicate possible combinations of elements or technical features of the invention. It is to be understood that the principle of the invention is not limited to those modes of the invention and combinations of the technical features, but may otherwise be recognized based on the thought of the present invention that disclosed in the whole specification and drawings or that may be recognized by those skilled in the art in the light of the disclosure in the whole specification and drawings.
(1) A fluid-filled vibration damping device comprising: a first and a second mounting member which are spaced apart from each other; an elastic body elastically connecting the first and second mounting members and partially defining a pressure-receiving chamber, the pressure-receiving chamber being filled with a non-compressible fluid whose pressure is changed upon application of a vibrational load between the first and second mounting members; an easily deformable flexible diaphragm partially defining an equilibrium chamber on one of opposite sides thereof, the equilibrium chamber being filled with the non-compressible fluid and has a volume easily variable; a first orifice passage for fluid communication between the pressure-receiving chamber and the equilibrium chamber; an elastic wall member being elastically displaceable and partially defining the pressure-receiving chamber; a restricting member disposed on one of opposite sides of the elastic wall member which is remote from the pressure-receiving chamber, the elastic wall member being elastically pressed to the restricting member; a working air chamber partially defined by the other side of the flexible diaphragm remote from the equilibrium chamber; and a negative pressure-regulating device adapted to apply different negative pressures to the working air chamber, depending upon frequencies of vibrations to be damped.
In the above-indicated mode (1) of the present invention, the pressure of the fluid within the pressure-receiving chamber is varied due to the elastic deformation of the elastic body, upon application of vibrational loads between the first and second mounting members. (a) Upon application of the vibrational loads over a low frequency band, the fluid is forced to flow through the first orifice passage between the pressure-receiving chamber and the equilibrium chamber, based on the fluid pressure difference between the pressure-receiving chamber and the equilibrium chamber, whereby the vibration damping device exhibits a high vibration damping effect with respect to the low frequency vibrations based on the resonance of the fluid flowing through the first orifice passage. (b) Upon application of the vibrational loads over a frequency band which is higher than the frequency band to which the first orifice passage is tuned, the fluid is forced to flow within the pressure-receiving chamber based on the elastic deformation of the elastic wall member, while the first orifice passage is substantially closed, whereby the vibration damping device exhibits a high vibrational isolating effect with respect to the relatively higher frequency vibrations, based on the resonance of the fluid flowing within the pressure-receiving chamber.
When the negative pressure is applied to the working air chamber, the flexible diaphragm is attracted to the side of the working air chamber, resulting in a reduced fluid pressure in the equilibrium chamber. The reduced pressure in the equilibrium chamber is transmitted to the pressure-receiving chamber through the first orifice passage, whereby the elastic wall member partially defining the pressure-receiving chamber is attracted to the side of the pressure-receiving chamber owing to its elastic deformation. Namely, the reduced fluid pressure applied to the elastic wall member acts to displace the elastic wall member in a direction remote from the restricting member against the elastic force of the elastic wall member in a direction toward the restricting member. This results in elastic deformation and displacement of the elastic wall member in the direction remote from the restricting member. In this condition, the elastic wall member is likely to be elastically deformable without being restricted by the restricting member. Thus, the spring constant of the elastic wall member is decreased, leading to a low wall spring stiffness of the pressure-receiving chamber. In this respect, the wall spring stiffness of the pressure-receiving chamber should be interpreted to mean an amount of fluid pressure change in the pressure-receiving chamber required to change a volume of the pressure-receiving chamber by a unit volume.
The application of the negative pressure to the working air chamber causes the decrease of the spring constant of the elastic wall member, so that the resonance frequency of the fluid flowing within the pressure-receiving chamber due to the elastic deformation of the elastic wall member shifts to the more lower frequency band. In the present fluid-filled vibration-damping device, therefore, the resonance frequencies of the fluid flowing within the pressure-receiving chamber can be changed by alternately turning ON and OFF the application of the negative pressure to the working air chamber, or alternatively by suitably regulating the level of the negative pressure applied to the working air chamber. Thus, the fluid-filled vibration-damping device can exhibit an excellent vibration damping or isolating effect with respect to vibrations over the different frequency bands.
In the fluid-filled vibration damping device constructed according to the present mode (1), the negative pressure applied to the working air chamber is not particularly limited, provided the negative pressure force is large enough to attract the elastic wall member to the side of the pressure-receiving chamber against the elastic force of the elastic wall member in the direction toward the restricting member, for thereby changing the wall spring stiffness of the pressure-receiving chamber. For instance, the working air chamber may be alternately exposed to the atmosphere and the negative pressure having a predetermined constant value.
Alternatively, the working air chamber is exposed to the negative pressure whose value is varied gradually or continuously. Further, the elastic wall member, partially defining the pressure-receiving chamber may be selected from a rubber plate member made of rubber material overall, or a canvas-reinforced or a rigid-material reinforced rubber plate member, for example. The elastic wall member may otherwise be formed of a combination of a rigid movable plate made of metal or synthetic resin materials and an elastic support fixed to the peripheral portion of the rigid movable plate for elastically support the rigid movable plate.
(2) A fluid-filled vibration damping device according to the above-indicated mode (1), wherein at least one of the elastic wall member and the restricting member has an abutting projection projecting therefrom toward the other of the elastic wall member and the restricting member, the elastic wall member being partially pressed to the restriction member at the abutting projection.
In this mode (2), the abutting part of the elastic wall member with respect to the restricting member is limited to the abutting projection. Therefore, the elastic wall member is likely to be elastically deformable at the part other than the abutting part, where the elastic wall member is not pressed to the restricting member, resulting in stability of the elastic deformation characteristics of the elastic wall member, and a resultant stability of the vibration damping characteristics of the damping device. Thus, the fluid-filled vibration-damping device of this mode (2) can exhibit a desired damping effect with high stability.
In this mode (2), at least one of the abutting parts of the elastic wall member and the restricting member is made of an elastic body, preferably. This arrangement is effective to reduce an impact noise upon collision of these abutting parts of the elastic wall member and the restricting member. It is also possible to provide a plurality of abutting projections between the elastic wall member and the restricting member. These abutting projections have different heights so that these abutting projections are sequentially brought into abutting contact with the elastic wall member or the restricting member, depending upon the level of the negative pressure applied to the working air chamber. This arrangement makes it possible to gradually change the elastic characteristics of the elastic wall member with high clarity and stability, depending upon the level of the negative pressure applied to the working air chamber. Preferably, each abutting projection is an annular member coaxially disposed about the center axis of the elastic wall member. The annular member extends continuously or discontinuously in its circumferential direction. The annular abutting projection ensures a stability of the elastic deformation of the elastic wall member with the each abutting projection held in abutting contact with the elastic wall member or the restricting member, leading to a resultant stability of the spring characteristics of elastic wall member.
(3) A fluid-filled vibration damping device according to the above-indicated mode (1) or (2), further comprising: a partition member which is adapted to divide the pressure-receiving chamber into a primary fluid chamber partially defined by the elastic body and an auxiliary fluid chamber partially defined by the elastic wall member; and a second orifice passage for fluid communication between the primary fluid chamber and the auxiliary fluid chamber, the second orifice passage being tuned to a frequency band which is higher than the frequency band to which the first orifice passage is tuned. In this mode (3) of the invention, the second orifice passage is formed within the pressure-receiving chamber for clearly defining the fluid passage through which the fluid flows within the pressure-receiving chamber upon application of the vibrational loads between the first and second mounting members. The presence of the second orifice passage facilitates flows of the fluid within the pressure-receiving chamber. The length and cross sectional area of the second orifice passage is suitably dimensioned so that the fluid-filled vibration damping device can exhibit an excellent vibration damping or isolating effect with respect to input vibrations over the specific frequency range.
(4) A fluid-filled vibration damping device according to the above-indicated modes (3), wherein one of the first and second mounting members is attached to a power unit of the vehicle, and the other of the first and second mounting members is attached to a body of the vehicle, such that the power unit is mounted on the body of the vehicle in a vibration damping fashion, the first orifice passage being tuned to a frequency band corresponding to that of engine shakes, the second orifice passage being tuned to a frequency band corresponding to a booming noise with the elastic wall member pressed to the restricting member, while being tuned to a frequency band corresponding to engine idling vibrations with the working air chamber exposed to the negative pressure.
In this mode (4), the vibration damping device is capable of exhibiting high damping effect with respect to vibrations required to damp in the vehicle, namely, the engine shakes and booming noises generated during running of the vehicle, and the engine idling vibrations generated during idling of the engine of the vehicle. While the negative pressure is applied to the working air chamber so that the vibration damping device exhibit a desired damping effect with respect to the engine idling vibrations, the negative pressure having a relatively high level is available from the air intake system of the engine, when the engine is in the engine idling mode. Thus, the vibration-damping device of this mode (4) effectively utilizes this high negative pressure to effectively control the damping effect thereof.
(5) A fluid-filled vibration damping device according to any one of the above-indicated modes (1)-(4), wherein the elastic wall member partially defines an interior space on the other side thereof remote from the pressure-receiving chamber, the interior space permitting an displacement of the elastic wall member and being exposed to the atmosphere through a communication hole.
In this mode (5) of the invention, the interior space partially defined by the elastic wall member is exposed to the atmosphere. This arrangement permits a stable displacement of the elastic wall member based on the negative pressure, which is applied to the working air chamber and acts on the elastic wall member via the non-compressible fluid filling the pressure-receiving chamber. Namely, the interior space exposed to the atmosphere is effective to prevent occurrence of a negative pressure within the interior space upon displacement of the elastic wall member, so that the elastic wall member is desirably displaced by applying the suitably regulated negative pressure to the working air chamber, without adverse influence of the occurrence of the negative pressure in the interior space. According to this mode (5) of the invention, the state or attitude of the elastic wall member may be desirably and effectively controlled by applying the suitably regulated negative pressure to the working air chamber. In addition, the interior space that is always exposed to the atmosphere is effective to reduce or prevent variation in temperature in the interior space, thereby eliminating or reducing possibility of undesirably variation in elastic characteristics of the elastic wall member and in the damping characteristics of the device, due to the temperature variation.
(6) A fluid-filled vibration damping device according to any one of the above-indicated modes (1)-(5), further comprising a pressure detecting device for detecting a pressure value of the non-compressible fluid, wherein the negative pressure applied to the working air chamber is corrected based on the pressure value detected by the pressure detecting device.
In this mode (6), the pressure of the fluid filled within he device is detected as a measurement. The obtained measurement is compared with the target value. Based on the difference between the obtained measurement and the target value, the negative pressure value applied to the working air chamber is controlled in a feedback fashion so that the negative pressure applied to the working air chamber has a target pressure value. This permits stabilized application of the negative pressure to the working air chamber and the elastic wall member, even if the negative pressure in the vacuum source varies. Thus, the vibration-damping device of the present mode (6) can exhibit desired vibration damping characteristics with high stability.
(7) A fluid-filled vibration damping device according to any one of the above-indicated modes (1)-(6), wherein the second mounting member includes a recess open to the first mounting member and a partition wall disposed within the recess such that the partition wall is located in an intermediate portion of the recess as seen in a depth direction of the recess, so as to fluid-tightly divide an interior space of the recess into a bottom-side space and an open-side pocket, the flexible diaphragm being disposed in the bottom-side space such that the flexible diaphragm fluid-tightly divide the bottom-side space into the equilibrium chamber and the working air chamber formed on the opposite sides of the flexible diaphragm, the elastic body elastically connecting the first mounting member and an open end portion of the open-side pocket of the second mounting member so that the open end portion of the open-side pocket is fluid-tightly closed by the elastic body, the elastic wall member being disposed in the bottom side of an interior space of the open-side pocket such that a peripheral portion of the elastic wall member is supported by an inner wall surface of the open-side pocket, while being pressed onto the partition wall, the pressure-receiving chamber being partially defined by and formed between the elastic body and the elastic wall member.
In this mode (7), the second mounting member has the above-indicated specific structure, namely has the recess. The recess of the second mounting member is effective to arrange the pressure-receiving chamber, equilibrium chamber, the working air chamber and the elastic wall member therein. This makes it possible to construct a desired fluid-filled vibration-damping device with a reduced number of component members and with a simple structure. While the space for installing an engine mount in a vehicle is limited, the present mode (7) permits to provide an engine mount with a compact size.

Fluid-filled vibration damping device having pressure receiving chamber whose spring stiffness is controllable


The present invention relates to a device for reading from and/or writing to optical recording media (1) having an optical scanner (2) for scanning the recording medium (1) by means of a light beam (3) and for generating scanning signals (HF) from the reflected beam (3), a data slicer (5) for converting a scanning signal (HF) output by the optical scanner (2) into a binary signal (HF″), an averaging unit (6) for forming an average value (M) from the scanning signal (HF, HF″) as input signal of the data slicer (5), and a control unit (14) for changing a parameter (T, OF) of the averaging unit (6). The object of the present invention is to propose a device of this type and also a suitable method therefor in which the average value (M) can be adapted to disturbances during the scanning of the recording medium. According to the invention, this is achieved by virtue of the fact that the control unit (14) has a unit (8, 10) for outputting a comparison value (S, HFN) and a comparator (7, 11) for comparing the average value (M) with this comparison value (S, HFN), and triggers a chance in the parameter (T, OF) in the event of the comparison value exceeded or undershot.

A device of this type is disclosed in EP-A-800 163. In this device, an average value is formed from the scanning signal and serves as input signal of the data slicer. A control unit serves to change the time constant for the averaging process when a great change occurs in the analogue scanning signal, caused by boundaries of different areas of data tracks on the recording medium. The known device may be regarded as having the disadvantage that although an adaptation of the average value in the case of a transition from one type of data area to another takes place more rapidly than without a change in the time constant, an adaptation of the average value is nonetheless restricted to this type of transition.

Device for reading from or writing to optical recording media having a control unit for a data slicer