An apparatus for providing a person with stimuli corresponding to an external operation on a sensor of a prosthetic device used in conjunction with a prosthetic or sensory impaired limb. A lower limb prosthesis includes sensors located in a prosthetic foot, contacts in the socket producing stimuli felt on the residual limb, and an electronic unit to adjust and control the magnitude of the stimuli. The sensors are either inductance-based or resistance-based. An upper limb prosthesis comprises a pressure sensor located in the thumb of a prosthetic hand, a vibrating motor generating sensations felt in the residual limb and an electronic circuit to control the vibrating motor and to adjust the intensity of the vibrations. An apparatus for a sensory impaired limb providing a sense of feel to a remote but unimpaired body part are constructed in a similar manner.

The present invention relates to devices for providing a person with a sense of feel in a prosthetic or sensory impaired limb.
The present invention is directed to a method for providing sensory perceptions in a sensor system of a prosthetic device. The method comprises sensing an external operation magnitude from a plurality of sensor groups, each sensor group sensing a fraction of the external operation magnitude. A plurality of sensory inputs from the sensor groups is generated in response to the external operation. An electrical input signal with a magnitude also is generated. The electrical input signal is controlled with the plurality of sensory inputs to create a plurality of sensory output signals collectively having a stimulus with a collective stimulus magnitude corresponding to the electrical input signal magnitude. Each sensory output signal has a fraction of the stimulus magnitude corresponding to the fraction of the external operation magnitude sensed by one of the sensor groups. Each of the sensory output signals is transmitted to a designated one of a plurality of contacts through a designated one of a plurality of channels.
Still further, the present invention comprises a sensory feedback system for use with a prosthetic device. The sensory feedback system comprises a power source that is adapted to transmit an electrical input signal. Included are a plurality of sensors each operable to create a sensory inputs in response to an external operation thereon. Further, the sensory feedback system comprises a plurality of contacts each adapted to receive a sensory output signal. The sensory feedback system includes a plurality of channels each connected to one of the plurality of contacts and adapted to carry one of the sensory output signals to the contact to which it is connected. The sensory feedback system also comprises a control and processing center adapted to receive the electrical input signal from the power source and to receive the sensory inputs from the pressure sensors, to control the electrical input signal by applying the sensory inputs to the electrical input signal to create the sensory output signals, and to transmit the sensory output signals to the contacts through the channels.
Further still, the present invention comprises a sensory feedback system for a prosthetic device. The sensory feedback system comprises a power source adapted to transmit an electrical power signal and an electrical input signal, a control and processing center adapted to receive the electrical input signal and to transmit a plurality of sensory output signals, and a plurality of contacts each adapted to receive a designated one of the sensory output signals. The sensory feedback system also comprises a plurality of inductance-based pressure sensors each adapted to receive the electrical power signal, to change the electrical power signal to a sensory input signal representing pressure applied thereto, and to transmit the sensory output signal therefrom. Also comprising the sensory feedback system is a sensor controller adapted to route the electrical power signal to each inductance-based pressure sensor and to return the sensory input signal from each inductance-based pressure sensor to the control and processing center. The control and processing center processes the sensory input signals and the electrical input signal to create a plurality of sensory output signals each representing the pressure applied to at least one of the inductance-based pressure sensors. In addition, the control and processing center transmits the sensory output signals to the contacts.
In another aspect, the present invention is directed to a lower limb prosthesis. The lower limb prosthesis includes a leg portion including a socket for receiving a residual limb of an amputee. A foot portion is attached to the leg portion. The foot portion having a sole, and a pressure sensor is positioned under the sole of the foot to provide an electrical resistance in proportional response to pressure against the sole of the foot. A power source is included to generate an electrical power signal, and an electrical power signal conductor is included to conduct the electrical power signal from the power source to the pressure sensor. A control and processing center also is included. The control and processing center is adapted to respond to the electrical resistance in the pressure sensor, whereby the power source is deactivated in response to electrical resistance in the pressure sensor which is greater than a selected level of electrical resistance and whereby the power source is activated in response to electrical resistance in the pressure sensor which is less than the selected level of resistance. A residual limb contact is included to transmit the electrical power signal to the residual limb. In addition, a channel is included to conduct a sensory output signal from the pressure sensor to the residual limb contact.
In yet another aspect, the present invention is directed to a lower prosthesis. The lower limb prosthesis comprises a leg portion including a socket for receiving the residual limb of an amputee. A foot portion is attached to the leg portion, the foot portion having a sole with a heel and a ball of the foot. A first pressure sensor is position under the ball of the foot adapted to provide an electrical resistance in proportion to pressure against the ball of the foot with respect to total pressure, and a second pressure sensor is positioned under the heel adapted to provide an electrical resistance in proportion to pressure against the heel with respect to total pressure. A power source is included to generate electrical current having a magnitude. An electrical current conductor is included to conduct electrical current from the power source to the first and second pressure sensors.
The lower limb prosthesis further comprises a first residual limb contact adapted to transmit electrical to a first location on the residual limb. A first channel conducts electrical current from the first pressure sensor to the first residual limb contact. A second residual limb contact is included to transmit electrical to a second location on the residual limb. A second channel conducts electrical current from the second pressure sensor to the second residual limb contact. The lower limb prosthesis further comprises a control and processing assembly adapted to create a first and second sensory output signal collectively having a stimulus with a collective stimulus magnitude corresponding to the electrical current magnitude. Each sensory output signal has a fraction of the stimulus magnitude corresponding to the fraction of the pressure sensed by the respective sensors with respect to the total pressure.
In still another aspect, the present invention comprises an upper limb prosthesis. The upper limb prosthesis includes an arm portion including a socket adapted to receive the residual limb of the amputee. A hand portion is attached to the arm portion, the hand portion having at least one digit. A power source generates an electrical current. A pressure sensor is installed in the at least one digit to receive the electrical current, to provide an electrical resistance to pressure on the at least one digit, and to emit, in response to the pressure, an electrical signal in proportion to the intensity of pressure on the at least one digit.
The upper limb prosthesis further comprises a control and processing center adapted to convert the electrical signal from the pressure sensor to a stimulus, to deactivate the transmission of the stimulus to the residual limb in response to a predetermined period of lack of muscle activity in the residual limb, and to activate the transmission of the stimulus in response to muscle activity in the residual limb. A residual limb contact is provided to receive the stimulus from the control and processing center and to transmit the stimulus to the residual limb.
The present invention is also directed to a system for providing sensory feedback to a person having a prosthetic device The system comprises a plurality of sensors. Each of the sensors is located at a respective area of the prosthetic device and has a sensor characteristic to define a plurality of sensor characteristics. Each of the sensor characteristics indicates a degree of exposure of the respective sensor to an external influence. The sensor characteristic of each of the sensors defines a sensor fraction of the total of the sensor characteristics.
The system further comprises a plurality of output elements, each of the output elements corresponding to one of the sensors and being in communication with a sensory-perceptive area of the person. The system also includes a control and processing center operatively connected to the sensors and to the output elements. The control and processing center produces a sensory output in each of the output elements to define a plurality of sensory outputs. The sensory output of each of the output elements defines an output fraction of the total of the sensory outputs. The output fraction is substantially equal to the sensor fraction of the corresponding sensor.

System and method for providing a sense of feel in a prosthetic or sensory impaired limb


A which winch can permit free-fall is disclosed, which includes a shaft adapted to be driven by a source of power, a first cone connected about the shaft to be driven therewith, and a second cone co-axial with the first cone and movable axially relative thereto. The second cone can be caused to assume one of two axial positions relative to the first cone, the arrangement being such that a rope or chain passing between the two cones can be driven by the winch when the second cone is in one of its two positions and can free-fall when the second cone is in the other of its two positions.

This invention relates to a rope winch and in particular to a winch which can permit ready free falling.
Winches of this type are particularly suitable for use as anchor winches as, when the anchor is to be lowered, the weight of the anchor can permit free falling of the rope or chain through the winch but, when the anchor is to be raised then the winch needs to be operative to raise the rope or chain.
The requirements of a winch of this type are firstly, when the winch is being used then the rope is firmly grasped or the chain is locked so there is little or no slipping, that for rope winches the winch whilst firmly grasping the rope does not damage this by undue compression, and in both cases, when the winch is released there is little obstruction to free falling.

Self-tailing winch with free-fall capacity


A boot needle roller bearing is designed to reduce friction between a flexible boot non-rotatably attached to a differential housing and a rotatable half-shaft. A plurality of rollers is retained axially between a first lip formed in the outer ring and a set of protrusions that are formed after installation of the rollers by bending prongs inwardly. The inner ring is retained axially between the protrusions and a second lip formed into the outer ring after installation of the inner ring.

FIG. 1 illustrates a portion of a front wheel drive transmission, including a differential. The differential gearing is enclosed in a housing 10. The differential gearing divides the power between two half-shafts. One of the half-shafts 12 is shown in FIG. 1 while the other is not. Half-shaft 12 is joined to the differential gearing by a universal joint, specifically a constant velocity joint 14, such that the axis of rotation of the half-shaft can differ slightly from the axis of rotation of the differential side gear. A flexible boot 16 seals an opening of the housing 10 through which half-shaft 12 extends. The boot does not rotate with respect to the housing. One end of boot 16 is fixed to the housing. The other end of the boot is joined to the half-shaft 12 via a bearing 18.


An input device, such as a mouse, for a computer is provided which enables a user to quickly and accurately position the input device during poor lighting conditions and determine whether the computer is ON. The input device according to the present invention is also arranged to illuminate the area proximate the input device. The input device includes a housing and an illumination device that is supported by the housing. Illumination from the illumination device is visible when the input device is placed on a supporting surface.

The present invention relates to an illuminated computer input device. More specifically, the present invention relates to a computer input device including an illumination source for illuminating the proximate area and for indicating whether the computer is ON or OFF.
Modern computer systems are designed to receive input from a number of input devices including mice and trackballs. Both the mouse and the trackball control the cursor on a computer screen, and include keys for performing certain computer operations. Frequently, a mouse includes a ball mounted to the bottom of a housing. When the mouse is moved over a supporting surface, the ball movement is translated into distance and direction information, which is supplied to the computer. The cursor on the computer screen is moved in a direction and by an amount corresponding to the movement of the ball. The mouse may also include buttons or keys, which control particular operations on the computer. In another arrangement for the mouse, the mechanical ball tracking system is replaced with an optical tracking system to measure movement of the mouse with respect to the supporting surface.
A trackball device is also a common peripheral for computers and workstations. In a trackball device, the tracking ball is rotatably mounted to a part of the housing that is exposed when it is resting on a supporting surface. To operate the trackball device, the housing remains stationary on a supporting surface and the ball is moved relative to the housing by a user. Once again, the movement of the ball is translated to corresponding movement of the cursor on the computer screen. The trackball device typically includes buttons or keys, which control particular operations on the computer.
The conventional mouse may be difficult to efficiently use in conditions of low lighting or no lighting, since there is nothing to render the exact position of the mouse visible in these conditions. More particularly, in order to enhance the visibility of the information displayed on a computer screen and to reduce glare from the screen, computers are often operated in either low or no lighting conditions. Operations requiring the use of the mouse are typically performed periodically, therefore the user is frequently required to locate and orient the mouse to perform a particular operation. Although the mouse is usually arranged within reach of the user, it may be difficult to efficiently locate and orient the mouse with low or no lighting.
A similar problem exists with trackball devices. Users typically desire to locate the movable ball quickly without relying solely on tactile feedback. Accordingly, poor lighting conditions can make quick and accurate positioning of the user""s hand on the trackball device or locating the trackball device inefficient.
Difficulty in quick and accurate locating of a mouse and/or trackball device can be more significant when the input devices are being used with certain computer programs. For example, certain programs may require the user to move his or her hand between a keyboard and the computer input device hundreds of times. Any efficiency gained in these repetitive movements may increase the user""s efficiency with the program and may make such repetitive movements more tolerable.
Additionally, some computer users will accidentally turn off his or her computer monitor without turning off the central processing unit (CPU). When this occurs, there may be no indication that the CPU is still ON. While some CPUs may include a small light indicating that the system is ON, such a small light on the CPU may be difficult to see. As many CPUs are stored underneath desks, a small indicator light on a CPU may not serve as a casual, easily noticeable indicator providing information as to whether the system is ON or OFF.
Therefore, a mouse and a trackball device are needed which would enable a user to quickly and accurately locate and position the mouse and trackball device during conditions where there is reduced lighting or no lighting. Additionally, a device to provide an improved indication as to whether the computer is ON or OFF is also needed. The present invention was developed to accomplish these and other objectives.
Many computer communication systems, such as email programs, are currently used. Many of these programs have notification features. Typically, with a notification feature of the program in an active mode, the receipt of an email may cause an icon or user interface to appear on the display device or may cause the computer to produce an audible signal. However, such icons and visual indicators take up valuable display area, and both the visual and audible indicators can sometimes be annoying, even to the point where many users disable such features. Therefore, a notification system that is more desirable to certain users was also needed.
In view of the foregoing, the present invention provides an improved computer input device that eliminates the deficiencies of the prior art.
The present invention also provides an improved computer input device that enables a user to more efficiently and accurately locate the device during reduced lighting conditions or no lighting conditions.
The present invention further provides an improved computer input device that enables a user to more efficiently and accurately position his or her hand on the device during reduced lighting conditions or no lighting conditions.
Further, the present invention provides an improved computer input device that illuminates the area proximate the device.
The present invention also provides an improved computer input device that indicates whether the computer is ON or OFF.
According to one aspect, the invention provides a computer input device having a housing that is configured to interface with a human hand, and an illumination device. The illumination device is coupled to the housing and is visible when the housing is placed on a supporting surface.
According to another aspect of the present invention, a computer input device includes a housing configured to interface with a human hand, and an illumination device. The illumination device is coupled to the housing and is visible when the housing is placed on a supporting surface. The illumination device can be used to illuminate the area proximate the computer input device.
According to yet another aspect of the present invention, a computer input device is provided which includes a housing configured to interface with a human hand, and an illumination device, which is coupled to the housing and is visible when the housing is placed on a supporting surface, where the illumination device indicates whether the computer is ON or OFF.
These and other objects and features of the present invention will be apparent upon consideration of the following detailed description of preferred embodiments thereof, presented in connection with the following drawings in which like reference numerals identify like elements throughout.


A gauge (1) for checking radial dimensions of a workpiece (60), e.g. the diameter of a crankpin orbitally rotating during grinding operations, includes a casing, a V-shaped reference device (4) and a rod that can move within the casing (2) with respect to the reference device, an end of the rod projecting from the casing and carrying a feeler (20) for touching the surface of the workpiece to be checked and transmitting the movements of the feeler to a transducer (22). A sealing system for preventing coolant, dust or other foreign matter from getting inside the casing includes a pneumatic conduit (6) for allowing compressed air to be blown from inside the casing to outside, and an internal seal that—in the non-operative condition—seals the opening through which the rod projects from the casing. According to an advantageous embodiment, the seal is fastened into a bushing guiding the rod and cooperates with a surface of the rod in order to get the tightness.

Gauges having the above-mentioned features are known in the art. An example is shown in International patent application published with n. WO-A-9712724 that refers to a specific apparatus, for checking the diameter of crankpins during their orbital motion about a geometric axis. The gauge—that is part of the apparatus and is shown in FIGS. 6 and 7 of the international application—includes a V-shaped reference device that rests on the pin to be checked and a tubular guide casing. A transmission rod axially translates in the guide casing and carries a feeler that contacts the surface of the crankpin to be checked. The displacements of the rod are detected by a measuring device with an inductive transducer that includes a first part integral with the tubular casing and a second part integral to and movable with the transmission rod.
In the specific application that is shown in the above-mentioned international patent application, for checking a crankshaft being worked on a grinding machine, the fixed part of the gauge—including the tubular casing, the V-shaped reference device and a part of the inductive transducer—is coupled to a support system allowing the whole gauge to perform the displacements that are needed to keep the contact with the pin to be checked while the latter orbitally moves.
The tubular casing has an opening through which the end of the transmission rod carrying the feeler projects. A sealing device closes such opening in order to prevent coolant and other foreign matter that is present in the working environment from getting into the casing. More specifically, the sealing device is made up of a metal bellows having its ends fixed to the rod and the casing, respectively, that has also the function of preventing axial rotations between rod and casing, so preventing the feeler from undertaking improper angular positions.
As an alternative, known gauges include tubular external gaskets of different shape and/or material, e.g. made of rubber, arranged between the casing and the movable element carrying the feeler. These gaskets perform a sealing action but have no substantial role as far as anti-rotation is concerned.
The increasing demand for internal combustion engines featuring the utmost compactness leads to the production of components having smaller and smaller dimensions. One of such components is the crankshaft, that requires extremely accurate dimensional checkings.
It can be hard or impossible to use the apparatus shown in the above cited patent publication WO-A-9712724 for checking crankshafts featuring very small nominal dimensions. For instance, in case that the crankpin to be checked has extremely small length, it is necessary that consequently small be the thickness of the part of the gauge including the V-shaped reference device, the feeler, the corresponding ends of the rod and of the casing, and the sealing system. In fact such part of the gauge, during the checking operations, must be in touch with or very close to the surface of the pin, i.e. has to be arranged between the walls of the mutually facing cheeks at the ends of the pin. It is especially troublesome to reduce the dimensions of the sealing system when the available allowance is less e.g. than 8-10 mm. In fact, it is problematic to get metal bellows or different tubular gaskets featuring suitable transversal size, safe connection to both the mutually movable parts and right properties ensuring the needed characteristics as regards compliance and tightness.

Gauge for checking radial dimensions of mechanical pieces


A structure for mounting a Hall effect sensor, the structure including: a mounting bracket, a mounting plate, a left supporting column, a right supporting column, and a first supporting column. The left supporting column and the right supporting column are protruded upwards from top surfaces of two adjacent teeth at the inner side of a certain winding slot, respectively. The first supporting column is protruded upwards from the top surface of the circular yoke at the outer side of the winding slot. The mounting plate is disposed on top surfaces of the first supporting column, the left supporting column, and the right supporting column. The mounting bracket is installed at the bottom of the mounting plate. The Hall effect sensor is installed in the mounting bracket.

Field of the Invention
The invention relates to a structure for mounting a Hall effect sensor of a motor.
Description of the Related Art
Typically, a Hall effect sensor is installed on the control circuit board of a motor, and then the control circuit board is mounted on the end insulator of the stator assembly or the rear end cover of the motor. However, such installation is unreliable, the control circuit board is difficult to position, and the Hall effect sensor tends to detach from the control circuit board.

Structure for mounting hall effect sensor of motor


Ear implants for auricular tissue reconstruction in a patient are provided. The ear implant may be a tissue scaffold multicomponent assembly for reconstruction of auricular tissue. Thus, the assembly may include both a first and a second tissue scaffold component. Each comprises a biocompatible polymeric material having a plurality of open pores configured to support cell growth. The first tissue scaffold component defines a central void region and at least a portion of an outer ear framework of the patient after implantation. The second tissue scaffold component defines a base portion. After implantation into the patient, the second tissue scaffold component seats within the central void region of the first tissue scaffold component, so that the second tissue scaffold component is secured to the first tissue scaffold component. Methods for reconstructing auricular tissue in a patient using such ear implant tissue scaffolds are also provided.

This section provides background information related to the present disclosure which is not necessarily prior art.
Ear malformations are among the most difficult to reconstruct due to their complex geometry. Where an unsalvageable auricle arises due to trauma, oncologic resection, microtia, anotia, and the like, auricular tissue reconstruction poses one of the most technically challenging surgical procedures for reconstructive surgery. Children with facial deformities, including microtia and anotia, develop self-awareness at approximately 4 years of age and are targeted for developmentally harmful teasing and bullying. Many patients with congenital ear deformities suffer from visual impairment as well. The external ear is critical to provide support for prescription glasses, and thus a child may be further deprived of optimal vision. Patients with microtia frequently find that their glasses are poorly supported, rendering them useless to aid in vision. This poses the potential for deprivation of multiple senses and further isolation of the child. Failure to restore size, shape, and function to the ear can result in catastrophic psychosocial harm.
Currently available treatment options to treat ear defects include autogenous cartilage reconstruction, use of prostheses, including synthetic alloplastic prosthetics, or observation. Autogenous cartilage reconstruction involves carving an autogenous rib framework as foundational support for overlying soft tissue. In this procedure, a highly skilled surgeon carves an auricular cartilage framework for implantation. These techniques demand the highest level of surgical and artistic ability as they rely on freehand carving of autologous cartilage, much like carving a sculpture. Even in the best of hands, outcomes can be inconsistent and undesirable. This technique can further suffer from other limitations, including introducing multiple surgical sites to the patient (including a site to remove rib tissue, along with the implantation site), as well as being a highly complex surgery with only a limited number of surgeons available who can perform it.
The current commercially available synthetic implants may be formed of a rigid synthetic polymeric material, such as high density porous polyethylene, like the MEDPOR™ ear implant commercially available from Stryker Corp. Benefits of using a commercially available synthetic implant include avoiding donor site morbidity from rib harvesting and lower variability with the framework appearance, in that the technically demanding hand carving is not required for the framework. However, commercially available implants do not have customizable framework for patient-specific anatomy. Only a single available ear implant device is available to meet the needs of the wide range of pediatric and adult patients needing reconstruction. Furthermore, rates of fracture, exposure, extrusion, and infection of porous polyethylene are believed to be unacceptably high. Implants formed from rigid, synthetic material, like high density polyethylene in conventional prosthesis device designs, have a greater incidence of framework extrusion, dehiscence, and soft tissue necrosis than autogenous cartilage reconstruction. These complications frequently require subsequent operations and anesthetic exposures with associated risks to address these complications. Finally, synthetic implants, like the MEDPOR™ implant device, do not have the capacity for growth, nor do they serve as a platform for cell seeding or tissue ingrowth.
It would be desirable to provide an ear implant that serves as a tissue scaffold that can be used on a variety of patients, ranging from the very young to older adult patients, allowing for increased projection and scaffold expansion, along with the structural stability and ability to withstand contraction and distortion and experiencing fewer complications after implantation. It would also be desirable to provide procedures that use low cost, common surgical tools that can be employed by most surgeons and even implemented in a medical mission setting.

Ear tissue scaffold implant for auricular tissue reconstruction

THE REGENTS OF THE UNIVERSITY OF MICHIGAN


The present invention is directed to ultraviolet shielding composite fine particles having transparency in a visible light region include (a) matrix particles comprising an aggregate of primary particles having an average particle diameter of from 0.001 to 0.3 .mu.m, the aggregate being formed while the primary particles retain their shapes; and (b) daughter particles having an average particle diameter of from 0.001 to 0.1 .mu.m, the daughter particles being dispersed in and supported by the matrix particles. In the composite fine particles, the daughter particles have a smaller band gap energy than the particles constituting the matrix particles and are capable of absorbing ultraviolet light, and the resulting ultraviolet shielding composite fine particles have substantially no catalytic activity.

The sunlight reaching the earth includes infrared light, visible light, and ultraviolet light, of which 5 to 6% is ultraviolet light. The ultraviolet light has short wavelengths, which are thus high-energy electromagnetic waves. Therefore, the ultraviolet light is known to decompose many kinds of materials and to damage living organisms.
Therefore, ultraviolet shielding agents are used for protecting skin from inflammation or skin cancer due to exposure of the skin to harmful ultraviolet light. For this purpose, the ultraviolet shielding agents are added to cosmetics. Also, they are used to prevent pigments from fading due to decomposition by ultraviolet light. For this purpose, the ultraviolet shielding agents are mixed with paints; however, this may cause unnatural skin whitening and a color change of paints. This can be prevented by increasing the transparency of such cosmetics or paints in the visible light region. Therefore, the ultraviolet light is desirably blocked while the transparency in the visible light region is maintained.
The ultraviolet shielding agent comprising organic compounds as effective ingredients prevents the transmission of the ultraviolet light on account of the above organic compounds which absorb the ultraviolet light. For example, an ultraviolet absorbent composition comprising substituted N,N'-bis-aromatic formamidines is known (Japanese Patent Examined Publication No. 61-09993). However, the organic ultraviolet shielding agents have the problem that although they can absorb the ultraviolet light, they are at the same time likely to be decomposed by the ultraviolet light, with the result of an undesirable lowering of the shielding ability over time. Regarding their application to cosmetics, the kinds and amounts of the ultraviolet shielding agents are restricted owing to deleterious effects caused on human bodies, and thus it is difficult to achieve a good shielding performance within a controlled range.
On the other hand, the ultraviolet shielding agent comprising an inorganic compound contains inorganic fine particles and prevents the transmission of ultraviolet light by the absorbing ability and the scattering ability of the composition. The inorganic ultraviolet shielding agent is superior to the organic ultraviolet shielding agent because the composition containing the inorganic ultraviolet shielding agent is not decomposed by the ultraviolet light with the passage of time and has little effects on the human body.
However, since the inorganic ultraviolet shielding agents are present in the form of particles, it is more difficult with inorganic ultraviolet shielding agents when compared with organic ultraviolet shielding agents to block the ultraviolet light while maintaining high transparency in the visible light region.
In order to possess an effective light shielding ability in the ultraviolet light region while maintaining high transparency in the visible light region (light wavelengths of from 400 to 800 nm), the composition has to be microgranulated to give ultrafine particles capable of being highly dispersed so as to increase the ultraviolet scattering ability. However, in the case of using ultrafine particles, dispersion stability problems may arise due to the aggregation of the ultrafine particles and the catalytic activities of the ultrafine particles.
In order to improve dispersibility, the ultrafine particle surfaces may be coated with other materials For example, skin cosmetics comprising an oily cosmetic base material and a hydrophobic titanium oxide powder are known (Japanese Patent Examined Publication No. 59-15885). However, a suitable solvent has to be selected depending upon the properties of the materials coated on the surface. Also, since the particles are still ultrafine, the aggregation of the ultrafine particles can only be lowered to a limited extent even if the surface treatment is conducted. In publications other than those mentioned above, there have been known cosmetics containing a powder obtainable by coating titanium oxide with a particular amount of mixed hydrates comprising silicate hydrates and aluminum hydrates, titanium oxide being nearly spherical or irregularly shaped and having an average particle diameter of from 30 to 70 nm, wherein the surface of the hydrate-coated titanium oxide is optionally further coated with a silicone oil (Japanese Patent Laid-Open No. 2-247109). However, since in this publication the above powder is obtained by drying and pulverization of the product obtained after coating with the mixed hydrates comprising silicate hydrates and aluminum hydrates or after coating the surface of the powder with the silicone oil, it is extremely difficult to pulverize the titanium oxide ultrafine particles to the size of the primary particles, because the titanium oxide ultrafine particles are aggregated showing a large particle diameter, so that the transparency and the ultraviolet shielding ability of the above obtained powder are lowered. Also, since fresh, uncoated surfaces appear after the pulverization process is carried out, the water-repellent ability or the oil-repellent ability of these surfaces is undesirably lowered. Such technological problems arise in maintaining the dispersibility of the ultrafine particles stable. Therefore, it is increasingly important to find a way to achieve a high dispersibility of the ultrafine particles and maintain it at that level.
Also, for the purposes of providing cosmetics comprising ultrafine particles wherein the ultrafine particles are easily and uniformly dispersed and the problem of the difficult handling of the ultrafine particles powder is eliminated, starting materials for cosmetics comprising metal oxide ultrafine particles having a particle diameter of not more than 0.1 .mu.m, a dispersion medium, and a dispersant, wherein the content of the ultrafine particles is not less than 10% by weight, have been known (Japanese Patent Laid-Open No. 6-239728) However, although the problems regarding the aggregation of the ultrafine particles and the deterioration of the dispersant, the dispersion medium, and cosmetics base materials caused by the catalytic activity of the metal oxide ultrafine particles have been known, they have neither been addressed nor solved in this publication. Moreover, the content of the metal oxide ultrafine particles in the starting materials for cosmetics is limited to not less than 10% by weight in order to control the amounts in the overall cosmetics in this publication. However, as long as the metal oxide ultrafine particles are uniformly and stably dispersed, the function of the metal oxide ultrafine particles is high, and the content of the metal oxide ultrafine particles needs not be limited to a minimum amount of 10% by weight in the starting materials for any kind of cosmetics.
Therefore, in order not to lower the ultraviolet scattering ability by the aggregation of the inorganic ultrafine particles, composites of the inorganic ultrafine particles are often formed with other relatively large carrier particles. For example, a thin flaky material dispersed with metal compound fine particles is known (Japanese Patent Laid-Open No. 63-126818). However, this publication does not disclose a specific construction of the fine particles for improving both the shielding ability in the ultraviolet light region and the transparency in the visible light region
Furthermore, composite fine particles comprising ultrafine particles dispersed in and supported by the solid material are proposed. Conventional ultraviolet shielding composite fine particles include, for example, a composite powder in which a fine particle powder, such as TiO.sub.2, is uniformly dispersed in plate particles of metal oxides, such as SiO.sub.2 (Japanese Patent Laid-Open No. 1-143821); and composite particles in which a zirconium oxide powder or an aluminum oxide powder is carried on a surface of the matrix particles comprising such materials as nylon resins, silicone resins, and silicon oxide, and a titanium oxide powder or a zinc oxide powder dispersed in an inner portion of the matrix particles (Japanese Patent Laid-Open No. 2-49717).
However, in order to use the above composite particles as ultraviolet shielding agents, the composite particles are usually dispersed in a medium in the actual environment. In this case, since the metal oxides, such as titanium oxide, contained in the composite particles have catalytic activity, the deterioration of the medium is likely to take place. Also, when the difference between the refractive index of the composite particles and that of the medium is large, light scattering takes place at an interface of the composite particles and the medium, thereby making both the transparency in the visible light region and the shielding ability in the ultraviolet light region poor. Although these problems need to be solved, they have not been considered in the above publications.
In order to suppress the catalytic activities of the ultrafine particles, methods for coating a surface of the ultrafine particles with various materials have been used. For example, Japanese Patent Laid-Open No. 5-70331 discloses the preparation of cosmetics comprising fine particle powder wherein a basic compound and at least one of a hydrocarbon compound having a boiling point of from 100 to 200.degree. C. and a silicone having a particular molecular structure are added during the production of titanium hydroxide which is obtainable by hydrolysis of a titanium alkoxide. However, in order to produce titanium hydroxide fine particle powder, the production process must comprise drying and pulverization processes, which results in a large particle diameter of the obtained titanium hydroxide fine particles. Thus, it is difficult for the particles to be highly effective in scattering ultraviolet light B (light wavelengths of from 280 to 320 nm), while maintaining high transparency of in the visible light region.
Also, the above publication has neither considered nor disclosed any method for producing ultrafine particles for the titanium hydroxide particles or methods for dispersing the ultrafine titanium hydroxide particles in cosmetics, in order to satisfy both high transparency in the visible light region and high shielding ability to the ultraviolet light. Moreover, in the ultraviolet shielding materials disclosed in this publication, titanium hydroxide or titanium oxide presumably absorbs the ultraviolet light B (light wavelengths of from 280 to 320 nm). This ultraviolet light B only penetrates the epidermis and a relatively upper layer of the dermis, causing sunburn or skin cancers. However, titanium hydroxide or titanium oxide does not at all absorb, light having wavelengths of from 350 to 400 nm, which are closer to those of the visible light of the ultraviolet light A (light wavelengths of from 320 to 400 nm). The ultraviolet light A reaches skin layers beyond the dermis, and produces suntan or fibrous modifications in the dermis. In other words, the ultraviolet absorbents disclosed in this publication mainly exhibit absorption of the ultraviolet light B by titanium hydroxide or titanium oxide, but their ultraviolet absorption effects are limited to a light wavelength of up to about 300 nm for an anatase-type titanium oxide and to a light wavelength of up to about 320 nm for a rutile-type titanium oxide.
Of the ultraviolet light reaching the earth, the energy proportion of the ultraviolet light A is about 15 times that of the ultraviolet light B. Therefore, in view of the above energy proportion of the ultraviolet lights A and B, it is important to shield both the ultraviolet light A as well as the ultraviolet light B, and simply shielding the ultraviolet light B is not sufficient. Moreover, it is becoming increasingly important to shield both the ultraviolet light B and the ultraviolet light A, while maintaining a high transparency in the visible light region. In particular, in the case where the ultraviolet light A is shielded, it is important to shield light wavelengths of from 350 to 400 nm, which are closer to light wavelengths of the visible light.
As mentioned above, in order to achieve an effective shielding ability in the ultraviolet light region which maintaining and high transparency in the visible light region, the ultraviolet shielding materials are made ultrafine so that they are present in a highly dispersed state. In order to further improve the transparency in the visible light region, it is important for the difference between the refractive indices of the ultraviolet shielding materials and those of surrounding media to be kept small. As the refractive index of the titania-containing composite powders disclosed in Japanese Patent Laid-Open Nos. 1-143821 and 6-116119 is limited to certain ranges determined by the compositional ratios of the components, the number of suitable dispersion media whose refractive index corresponds to the refractive index of the composite powder is inevitably limited as well. Therefore, great problems have been encountered in controlling the refractive index of the composite powder so as to match it with the refractive index of the dispersion medium used. Therefore, an effective means for solving these problems is in great demand.
Further, Japanese Patent Laid-Open No. 4-65312 is concerned with metal compound-containing porous silica bead, the production method thereof, and the powder deodorant produced. In this publication, the fine particles of the metal compounds having a primary particle diameter of from 0.001 to 0.3 .mu.m are contained in the porous silica bead in an amount of from 0.1 to 30% by weight, and the porous silica bead contain substantially no voids of not less than 0.3 .mu.m. In this case, when the fine particles of the metal compounds contained therein are suitably selected so as to have a refractive index close to the refractive index of silica (the refractive index being in the range of from 1.4 to 2.0), silica particles with further improved transparency can be obtained. However, the publication only discloses the range for the refractive index of the metal compound fine particles contained in the inner portion of the composite particles, but none of the total refractive index of the composite particles.
As explained above, in order to solve the problems inherent in the ultraviolet shielding agents comprising the ultrafine particles, several attempts have been made to use composites mainly comprising metal oxides. However, many of the compounds exhibiting good ultraviolet absorption properties, such as TiO.sub.2 and ZnO, have relatively high refractive indices, so that the composite fine particles incorporating these ultrafine particles have refractive indices notably higher than aqueous solutions, conventional organic solvents, polymers, etc. When the above composite fine particles are dispersed in a medium, the present inventors have found that light scattering in the visible light region takes place at the interface of the composite fine particles and the medium, whereby the transparency of the medium is drastically lowered. However, a technical method of controlling the refractive index of the ultraviolet shielding particle of the composite fine particles has not been proposed so far.
In the fields of resin fillers, fluorine-based inorganic compounds, such as MgF.sub.2 and CaF.sub.2, or fluorine-based organic polymeric compounds, such as polyethylene tetrafluoride, which are known as low-refractive index materials having high transparency, are added to powders, etc. as starting materials to lower their refractive indices.
For instance, Japanese Patent Laid-Open No. 4-85346 discloses a glass powder, used as a transparent inorganic powder for resin fillers, comprising metal oxides, such as SiO.sub.2, Al.sub.2 O.sub.3, B.sub.2 O.sub.3, BaO, SrO, ZnO, and MgO, and metal fluorides, the glass powder having a refractive index (n.sub.D) adjusted in the range of from 1.44 to 1.70. The publication discloses that since the glass powder has a high light transmittance and does not show strong alkalinity, the resins do not undergo any substantial modification, and are significantly stabilized in resin hardening. However, the publication merely discloses that a highly transparent inorganic powder for resin fillers is obtainable by changing the compositional ratio of the materials, and the above metal oxides, etc. are not present as particles in the final product powder owing to the high-temperature melting production, and this publication does not refer to the ultraviolet shielding ability. Further, this publication does not disclose that the composite fine particles comprise aggregates of two or more kinds of fine particles as in the present invention or that the composite fine particles have the compositional dependency with respect to an average refractive index of the composite fine particles.

Ultraviolet shielding composite fine particles, method for producing the same, and cosmetics


An actual slip ratio of a wheel is estimated from a slip ratio speed of a wheel calculated according to a running state of a vehicle based on relationship between a slip ratio of the wheel of the vehicle and the slip ratio speed of the wheel set in advance. Typically, the actual slip ratio is estimated supposing that the slip ratio of the wheel calculated according to the running state of the vehicle, when a change rate of the slip ratio speed becomes larger than a predetermined value set in advance, is a reference slip ratio determined in advance according to the relationship between the slip ratio and the slip ratio speed set in advance. Therefore, it is possible to improve control accuracy when controlling a state of the vehicle by decreasing an effect of operation by a driver and a road surface, for example.

Patent literature 1 discloses as a conventional vehicle state calculating device or vehicle control device, an antilock brake control device of a vehicle, which calculates an estimated vehicle speed based on a wheel speed detected by wheel speed detecting means and wheel acceleration/deceleration calculated by wheel acceleration/deceleration calculating means, judges a slip ratio of a wheel based on the estimated vehicle speed and the wheel speed, and determines an operation control amount of brake fluid pressure adjusting means based on a result of judgment, for example.

Vehicle state calculating device and vehicle control device


A method and system are provided for preventing network service shutdowns resulting from denial of service (DOS) attacks. First, parameters are monitored corresponding to network elements carrying communication signal traffic in a communications network, and, based on the parameters, if a DOS attack is indicated, performing the following for each instance of communication signal traffic: accessing data structures for data relating to protected communication signal traffic, and, based on the data, determining if the communication signal traffic is designated as protected. Finally; based on the determination, cleaning and forwarding each protected communication signal to its respective destination.

Network infrastructures as well as customers of network service providers may be subject to any number of malicious attacks by hostile machines (attackers) designed to shutdown or damage network services. One common type of attack is a distributed denial of service (DDOS) or denial of service (DOS) attack. A DOS attack may encompass one of two common attack types. One type of a DOS attack involves an attacker sending a sufficiently large number of messages to a targeted IP address, such as a client of a network service provider. Another type of attack is more general in nature, and targets the core network of the network service provider, which, in turn, affects service to all clients of the service provider.
DOS attacks generally involve an attacker forging (spoofing) messages and sending the spoofed messages to a targeted destination. The targeted destination may be, for example, a router within the core network of the service provider or a customer of the service provider. With a sufficiently large number of spoofed messages, the targeted destination's services (e.g. phone and data services) may become clogged and rendered inoperable.
Many service providers offer to customers, in addition to network service, detection and mitigation service subscriptions to prevent interruptions in the customer's service due to malicious attacks. Detection services determine whether the subscribed customer or network core is experiencing a DOS attack. On the other hand, mitigation services separate good traffic from bad traffic and forwards the good traffic to the subscribed customers.
Detection service may be provided at the customer-end of the network, or in the core network of the service provider, such as at an incoming provider-edge (PE) router. Further, the detection service may be implemented as computer-readable medium or integrated as a part of the network architecture. At the customer-end of the network, detection service may employ an in-line tap and detector coupled to the service provider's network pathway. A tap may be, in one example, a passive splitter that siphons off a portion of the incoming traffic and directs the siphoned portion to a detector having a suitable bandwidth. The detector monitors the bandwidth usage of the service provider's network by the customer and, over time, determines if the bandwidth usage has increased beyond a certain threshold. This increased use may indicate a malicious attack is in progress. If the detector determines an attack is in progress, the traffic incoming to the customer is routed to a cleaning center. The cleaning center separates the bad traffic from the good traffic. The separation may be based upon information in the header portion of the incoming messages. The good traffic is then redirected to the customer, thus mitigating the malicious attack and minimizing downtime experienced by the customer due to the attack.
At the network core, detection service may employ monitoring tools for collecting information related a trend in the bandwidth usage that extends beyond a certain threshold, which indicates a malicious attack. The monitoring tools may comprise a stand-alone hardware element incorporated into the network architecture or computer-readable medium installed on an existing hardware element. Once the threshold is met, the network service provider shuts down all network elements and pathways in the core network affected by the malicious attack. The shutdown prevents damage and other adverse consequences to components in the core network and related customer-end network elements. Once the monitoring tools determine the malicious attack has subsided, the service provider re-opens all network elements previously shutdown.
One deficiency of the aforementioned detection services on the customer-end is the cost and efficiency of providing detection services for each individual subscribing customer. Further, another deficiency of providing the aforementioned detection services on the front-end provider-edge of the core network is that an outage of network service to all customers occur during the attack. Although a customer subscribes to detection and mitigation services offered by the network service provider, the service shutdown in response to the malicious attack may last about a few hours to a few days.
This background is provided as just that, background. The invention is defined by the claims below, and the listing of any problems or shortcomings of the prior art should not give rise to an inference that the invention is only to address these shortcomings.

Detecting and addressing network attacks


A method of stabilizing an electrolysis cell with a boundary, a liquid metal layer and an electrolyte layer having specific operational and geometric parameters, and comprises the steps of determining amplitude and frequency values for a desired external, time-varying and/or alternating magnetic field through wave reflection analysis on a theoretical wall whose parameters are representative of the cell wall's parameters; and imposing on said cell an external, time-varying and/or alternating magnetic field having substantially the same amplitude and frequency values determined in the wave reflection analysis so that the resultant magnetic field imposed on the cell tends to parametrically and dynamically desynchronize the occurrence of resonance instability near the cell's walls.

1. The Field of the Invention
The invention relates to liquid metal electrolyte systems and is especially, though not exclusively, applicable to improving the efficiency and reducing the operating costs of modern-day aluminium reduction cells.
2. The Relevant Technology
The invention will be exemplified, and will subsequently be described and illustrated in this present specification, with reference to aluminium reduction or smelting.
Modern aluminium production plants consume huge amounts of electricity.
Virtually all of them operate by reducing alumina in electrolysis cells or, as they are called, pots. In practise a commercial aluminium smelting plant will consist of several hundred such pots and will operate on a continuous production basis.
There are two remarkable features of this process. First, it has remained virtually unchanged for over a century since it was first successfully developed (and indeed it is still universally known as the Hall-Héroult process after the two scientists who first independently discovered it). Second, the amount of energy consumed by the process is quite staggering.
It has been estimated that the modern-day production of aluminium consumes about two percent of all electricity generated worldwide (!) and yet much of this energy is absorbed in overcoming resistive losses in the poorly conductive highly resistive electrolyte layer of each individual smelting cell. The primary electrical driving current can be of low voltage but must be of relatively enormous amperage in order for the process to work, given these drawbacks, and it follows that any modification which enables that current, the electrolyte thickness, or both, to be reduced at all would indeed produce reductions in energy consumption which could truly be described as significant in relation to those needed without the modification today.
Efforts have been made, naturally, to overcome this problem but the main limiting factor is that, if the electrolyte thickness is reduced beyond a certain critical level, instabilities begin to occur at the interface between the liquid electrolyte and the liquid aluminium. These instabilities, which manifest themselves as a sloshing of the liquids within the cell, have been the subject of intensive research for some 20 years or more. In effect, these are interfacial gravity waves, modified by the external magnetic fields which pervade the cell and when a certain stability threshold is exceeded, these waves can grow by absorbing energy from the ambient electric and magnetic fields.
The good news is that the wave period is measured in minutes and its growth rate in hours, and so the problem ought to be susceptible to some controlled solution. The real problem is that once such a wave takes hold, it can disrupt the electrolysis to such an extent that the cell must be withdrawn from operation. In an extreme case, it could destroy the entire cell.
Previously proposed means for trying to eliminate these instabilities include:                Placing baffles in the aluminium to break up the long-wavelength waves whilst relying on friction to dissipate the short-wavelength components.        Have a sloping cathode block so that the aluminium continually drains away.        Destroy the standing waves by placing hydraulic energy absorbers at the edges of the cell.        Tilt the anode in harmony with the wave so that the electrolyte layer remains almost uniform and thus one eliminates the perturbation in current.
The first of these prior proposals remains simplistically attractive but both it and the second one are limited by the need to find, in practical environments, a material which survives the chemically aggressive environment in a smelting cell. The second option has another difficulty in that thin aluminium layers will not properly wet the cathode and this cannot easily or cheaply be overcome. Whilst the third option is self-explanatory, the most recent research has concentrated on the final one but as far as is known, no practical embodiment has yet emerged.
Furthermore, a paper published by Elsevier Science dated 12 Nov. 2001 by authors A. Lukyanov, G. El and S. Molokov, is deemed to be relevant to the present application as it defines the general background of the mechanism of instability, however primarily in the context of determining the reflection coefficient rather than proposing a practical solution for controlling instability in a cell as is one of the objectives of the present application.
In summary, despite the length of time the problem has been around, and the importance of modern aluminium production to the progress of industrialised society as a whole in an era when, paradoxically, conservation of energy is becoming more urgent than ever, instability of aluminium reduction cells remains the central and unsolved problem in the industry at large.
The Inventive Concept
The applicants are proposing a modification of existing current-driven liquid metal electrolyte systems (of which an aluminium reduction cell is the obvious but not limiting example) which starts from a point quite different from any of those outlined above—but which could, we believe, be used in any appropriate combination with some, all, or any of the prior proposals outlined above.
In essence, we impose on such a system an additional, external, magnetic field whose design and operating parameters are so chosen as to enable the electrolyte thickness to be reduced significantly in relation to those needed without the modification. By doing this, we address the very source of the instability, which happens due to the interaction of the currents induced by the interface motion with the external magnetic field.
Based on our understanding of the fundamental mechanism governing the instability, we believe it to be possible that, with appropriately designed coils, a ring current around the cell inducing an automating magnetic field will stabilise the cell to an appreciable if not total extent.
Thus, rather than trying to understand fully all the processes happening inside the cell we effectively suppress the fluctuations by imposing a suitably powerful and time-dependent magnetic field around it. A modern aluminium (or any other metal) reduction cell is a complex and highly optimised device. There are a multitude of supple physical and chemical processes occurring within such a cell and many of them will inevitably interact. A small change in any one parameter could well have quite unexpected consequences and these may or may not be either inter-related or predictable at all. The size alone of the primary driving current makes it almost impractical to try to make relatively small adjustments to any one aspect of cell operation—for example, the "anode-tilt" approach exemplified in the fourth prior proposal outlined previously—with any real guarantee of even partial success.
We by contrast take an overview and we believe that, with appropriate design and with the ability to adjust the controlling parameters (i.e. field amplitude, frequency, and constant background) we are more likely to achieve real suppression of instability in a practical format within the foreseeable future.
In a subsidiary aspect, the magnetic field applied is essentially a vertical magnetic field. In this direction, significant effect on instability in liquid metal electrolyte occurs which allows the thickness of electrolyte itself to be reduced below levels at which conventionally instability would occur.
In a further subsidiary aspect, the magnetic field is dependent on an amplitude and frequency whose values are approximated through wave reflection analysis on an infinite wall. This is advantageous as it allows an appropriate magnetic field to be rapidly determined rather than relying on the skilled man to determine an adequate field through more extensive analysis.

Stabilisation of liquid metal electrolyte systems


A nutritional or dietary supplement composition that strengthens and promotes a general eye health benefit for aging adults, including retinal health through the prevention, stabilization, reversal and/or treatment of visual acuity loss by reducing the risk of developing late stage or advanced age-related macular degeneration in persons with early age-related macular degeneration. The nutritional or dietary supplement composition may likewise reduce the risk of vision loss associated with the development of cataracts.

Macular degeneration associated with age is the leading cause of severe visual acuity loss in the United States and Western Europe in persons aged 55 years old or older. The cause of macular degeneration is unknown.
Many nutritional supplements are currently on the market for vision support, including those under the following brand names: Xanthalin, Xantha View, Vision Essentials, Occulo Nutrients, Vision Defense 14, Eye Shield, Eye Rite, Macular Degeneration, and Occuplex w/Lutein (among others). U.S. Pat. Nos. 7,842,722, 7,267,830, 6,649,195, 660,297 provide a few examples.
Previously-available supplements comprise different formulations from the present invention. Moreover, the present formulation provides surprising results compared to the other vision-related nutritional supplements.

Nutritional supplements for eye health and related methods


The present invention is a replacement gunstock assembly for rifles. The assembly comprises a stock body with a uniform mounting structure and one of a series of adapters made to accept the mounting structure and then mount, in turn, on a given rifle platform. Also disclosed is attachment structure for holding the stock body and adapter together, specifically a pair of plates and a set of bores in the modules through which a pair of bolts pass and other interfacing surface geometry.

The present invention is a replacement gunstock for various rifle platforms. It should be noted, that while technically not rifles, the invention may be practiced with other long guns, like shot guns, and the term "rifle" should be read to include any type of personal long gun. Replacement stocks are known in the prior art and are usually made for one particular rifle platform, e.g either the M16/AR15, AK-47, FAL or other existing platforms. However, replacement stocks made for one of these platforms are usually not made for another. As such, adapters are occasionally made to convert one type of stock to fit on another. These adapters typically become a weak point on the rifle or create extra length which makes a rifle more cumbersome. The factor causing these drawbacks is simple, a replacement stock is made and then an adapter is made to accommodate platforms other than the one for which it was created. No replacement stock on the market is made with universal use on rifle platforms in mind.
The present invention represents a departure from the prior art in that the gunstock of the present invention is actually designed from the onset as being used on all platforms. As such it is specially structured to interface with an adapter which is likewise structured for enhanced strength and adaptability to a given platform. The resultant gunstock is therefore stronger, has a better interface with the platform and more ergonomically desirable than replacement gunstocks on the market.


A wheelchair ramp structure is arranged to include first and second U-shaped tracks hingedly mounted relative to one another cooperative and parallel to third and fourth U-shaped tracks, wherein the first and third U-shaped tracks include an adjusting connector link directed therebetween to provide for adjustment and maintaining such adjustment in a spatial relationship of the first and second tracks relative to the third and fourth tracks. The first and second tracks are arranged for hinged mounting relative to one another, as well as the third and fourth tracks permitting ease of storage of the organization during periods of non-use.

1. Field of the Invention
The field of invention relates to wheelchair ramp structure, and more particularly pertains to a new and improved wheelchair ramp apparatus wherein the same is directed to the ease of positioning and mounting relative to a vehicle relative to a vehicle relative to loading and unloading a wheelchair structure thereto.
2. Description of the Prior Art
Wheelchair ramp structure of various types is indicated in the prior art such as exemplified by the U.S. Pat. Nos. 4,528,711; 4,912,796; 3,874,527; as well as U.S. Pat. No. 5,033,146.
The instant invention attempts to overcome deficiencies of the prior art by providing for wheelchair ramp structure arranged for compact storage, as well as maintaining proper positioning and capturing of a wheelchair within U-shaped track structure and in this respect, the present invention substantially fulfills this need.


A multi-media data display device for displaying a plurality of multi-media data items on a display screen is provided. Each of the multi-media data items has geometric data and attributive data defined by positional information in an n-dimensional space. The multi-media data display device includes: a view area setting section for setting a view area from a multi-media data space, in which the plurality of multi-media data items exist, based on access position information having a predetermined dimension, the view area having been selected as including at least one of the plurality of multi-media data items as an object to be displayed, the access position information having been produced within the multi-media data display device or provided from the outside of the multi-media data display device, and a display control section for independently controlling, based on the access position information, a display style of an individual one of the plurality of multi-media data items existing within the selected view area when the individual multi-media data item is displayed on the display screen.

1. Field of the Invention
The present invention relates to a multi-media data display device, and more specifically to a multi-media display device for defining the display styles of an individual object to be displayed by a function in a one-dimensional or multi-dimensional data space in which multi-media data associated with the object exist and displaying the individual object by independently varying the display styles thereof based on the positional coordinates in the data space.
2. Description of the Related Art
First, three-dimensional viewing commonly used for multi-media data display processing will be briefly described.
Three-dimensional viewing is a process for displaying an individual solid-state display object on a two-dimensional display screen of a display device based on the geometric data specifying the individual object. The geometric data is represented by the positional coordinates of the object in a three-dimensional space.
FIG. 15 is a chart diagrammatically illustrating the process flow executed in the three-dimensional viewing.
As shown in FIG. 15, the three-dimensional viewing roughly includes the following four process steps: a clipping process step (Step S11) with respect to a view volume; a projection process step (Step S12) onto a projection plane; a transformation process step for obtaining a viewport at the normalized coordinates (Step S13); and a transformation process step (Step S14) for obtaining the coordinates for a physical (display) device. Hereinafter, the processes executed in the respective process steps S11 through S14 will be described.
The clipping process step S11 executed with respect to a view volume is a process for specifying,a three-dimensional visible field based on predetermined conditions when the location of a view point and a viewing direction are set (in this specification, the "view point" means a point from which viewer's eyes are turned onto an object and the "viewing direction" means a direction in which the viewer's eyes are turned onto the object). A view volume is selectively defined from such a three-dimensional visible field.
The projection process step S12 is a process step for transforming the points composing an individual object existing within the view volume into the points on a two-dimensional view coordinate space Hv (i.e., a projection plane).
Hereinafter, these process steps will be specifically described.
FIG. 16 is a diagram for illustrating the clipping process with respect to the view volume and the projection process for the objects existing within the view volume. FIG. 16 shows a three-dimensional space in which a plurality of objects exist (such a space will also be referred to as an "object space"). Herein, a "projection" is a process for transforming the points composing a solid-state object in a three-dimensional space into the points on a two-dimensional view coordinate space (i.e., a projection plane).
In FIG. 16, "3D" refers to a three-dimensional viewing coordinate system including x-, y- and z-coordinates and corresponding to the two-dimensional display screen (hereinafter, simply referred to as a "screen") of a physical (display) device. In this 3D coordinate system, the x-axis direction corresponds to a direction extending to the right of the screen, the y-axis direction corresponds to a direction extending to the top of the screen and the z-axis direction corresponds to a direction extending to the depth of the screen. Herein, the coordinates of a view point Ps within the viewing coordinate system (i.e., data access coordinates to be described later) are assumed to specify the coordinates (x0, y0, z0) of the origin of the 3D viewing coordinate system, and the direction in which a viewer looks from the view point Ps into the viewing coordinate system (hereinafter, such a direction will be referred to as a "viewing direction") is assumed to be the z-axis direction of the 3D viewing coordinate system and be represented by a direction vector w (i.e., a data access vector to be described later).
In FIG. 16, when the viewer looks from the view point Ps into the screen along the direction indicated by the direction vector w, five objects OB1 to OB5 are located within a visible field Rs and two more objects OB6 and OB7 are located outside of the visible field Rs. Herein, the visible field Rs is a pyramidshaped spatial domain defined by the one-dot chains in FIG. 16. Since the respective objects OB1 to OB7 exist within the 3D viewing coordinate system, the geometric data specifying an individual object are given by the (x, y, z) coordinates of the points composing the individual object.
In the three-dimensional viewing process, all the objects included within the visible field Rs are not to be displayed. Rather, a process for setting an area including the desired objects to be displayed is required to be performed. Such a process is the above-mentioned clipping process with respect to the view volume in the process step S11.
More specifically, a boundary plane Hf (or a front clipping plane) closer to the viewer and another boundary plane Hb (or a rear clipping plane) more distant from the viewer are set, while assuming the view point Ps as a reference point such that both planes are vertical to the viewing direction indicated by the direction vector w. Then, the objects OB2 to OB4 included within the spatial domain Rv (hereinafter, such a specified domain of the view volume will be referred to as a "view area") interposed between the two clipping planes Hf and Hb within the visible field Rs are selected as the objects to be displayed. It should be noted that the objects OB1 and OB5 are certainly included within the visible field Rs but are excluded from the view area Rv and located outside the view area Rv. Thus, in this case, the objects OB1 and OB5 are not selected as objects to be displayed.
A center projection process producing visual effects similar to those produced by a photographing system or a visual sensing system of a man may be suitably employed as the projection process as one of the process steps of the three-dimensional viewing. Hereinafter, such a center projection will be described.
In this center projection process, first, the view point Ps is assumed to be the center of projection in the visible field Rs shown in FIG. 16. Next, a projection plane (or a view plane) Hv which is distant from the center of projection Ps by a predetermined distance and is vertical to the z-axis is defined. Then, the objects OB2 to OB4 located within the view area Rv are projected onto the projection plane Hv. In other words, this is a process for transforming the points composing the three-dimensional objects OB2 to OB4 located within the view area Rv into the points on a two-dimensional viewing coordinate space (i.e., the projection plane) Hv. This process is accomplished based on a proportional calculation using the specific distances from the center of projection Ps to the points composing the individual object and the distance from the center of projection Ps to the view plane Hv.
Next, the processes executed in the process steps S13 and S14 will be described.
FIG. 17 is a diagram illustrating a process for transforming a point (or a pixel) Phv on the projection plane (or the view coordinate plane) Hv into a pixel Phd on a display screen of a physical device via a point Phs within a viewport Vp on a normalized coordinate plane Hs in the three-dimensional viewing process.
As shown in FIG. 17, first, in the process step S13, a point Phv on the projection plane (or the view coordinate plane) Hv is transformed into a point Phs within the viewport Vp on the normalized coordinate plane Hs. Herein, the viewport Vp is a zone defined as a part of the normalized coordinate plane Hs and has the same aspect ratio as that of the projection plane Hv.
Next, in the process step S14, the point Phs on the normalized coordinate plane Hs is transformed into a point Phd on a physical device coordinate plane Hd, which corresponds to the screen of a display device.
The coordinate transformations performed as the process steps S13 and S14 establishes a correspondence between a point (i.e., the pixel Phv) which has been projected onto the view coordinate plane (or the projection plane) as an integral part of a resulting solid-state object (i.e., a 3D object) and one of the points (i.e., the pixel Phd) composing the display screen of the display device. As a result, a 3D object (or an object having geometric data given by coordinates in a three-dimensional space) can be displayed on the display screen of (the 2D display) of the display device.
Hereinafter, a conventional multi-media data display method for effectively performing a display process on three-dimensional graphics (J. D. Folley, A. van Dam, "Computer Graphics Principles and Practice", 2nd edition, Addison-Wesley Publishers Co., pp. 727-728, 1990) will be briefly described.
Such a method is called a "depth cuing" for controlling the display of graphics. The depth cuing is generally used for effectively enhancing the perspective perception of an object. This is a method for enhancing the perspective perception of an object to be displayed by setting the display color depth of the object depending upon the distance from the view point Ps to the view area where the object is located in the three-dimensional viewing process such that the more distant object is displayed in the lighter color.
Such a depth cuing method controls the display styles of an object based on the view parameters. Thus, the data of the object to be displayed such as geometric data and attributive data is not directly associated with the display control by means of the depth cuing.
As described above, in accordance with a conventional multi-media data display control method, a display control is performed primarily based on a view control, i.e., by setting the visual appearance (or the display styles) of an object in accordance with an individual view area. It is noted that a view area in a three-dimensional space exactly corresponds to the finder of a camera. Thus, controlling an object in accordance with the individual view area corresponds to controlling the imaging state of an object to be photographed based on the light incident from the object by providing a filter for the lens of the camera.
Accordingly, in a conventional display control method, the visual appearance of all the objects located within the view area is determined by the parameters (or the variables) of the view area and the geometric data and the attributive data specifying the objects. For example, if the view point moves, then all the objects (including important ones and unimportant ones) within a view area becomes smaller (or the color thereof becomes lighter) or larger (or the color thereof becomes deeper).
Next, a navigation system will be described as an exemplary specific application of a conventional display control method using the depth cuing.
FIG. 18 is a block diagram illustrating a conventional navigation system. As shown in FIG. 18, the conventional car navigation system includes a car navigator apparatus 500 and a display 540. The car navigator apparatus 500 includes: an object database 530 in which the data of all the objects OB1 through OBn to be displayed by this system are stored; a view variation detector 520 for detecting the variation in view parameters; and a display controller 510 for controlling the display of the objects on the display 540 based on the data stored in the object database 530 in response to the detection output of the view variation detector 520.
In the object database 530, an ID table for all objects 530a (hereinafter, such a table will be simply referred to as an "ID table"), on which the basic data D1 to Dn including the geometric data specifying the shapes and the positions of all the objects OB1 through OBn to be displayed and the attributive data specifying various attributes thereof such as a color are written so as to correspond to all the objects OB1 through OBn, is stored.
The view variation detector 520 includes a view point movement detection section 521 for detecting the movement of the view point position (i.e., in this case, the movement of a car) and a viewing direction detection section 522 for detecting the variation of the viewing direction (i.e., in this case, the variation of the travelling direction of the car).
The display controller 510 includes a data storage section 511 for temporarily storing therein the basic data of the objects to be displayed at a point in time when the car is at a predetermined location and on the point of proceeding in a predetermined direction. In the data storage section 511, a display object table (hereinafter, simply referred to as an "S table") 511a for writing thereon the basic data of the objects so as to correspond to the respective objects has been formed. The display controller 510 further includes a data retrieving section 512 for reading out the basic data of the objects included within the view area Rv (see FIG. 16), i.e., the basic data of the objects to be displayed in accordance with the currently detected location and travelling direction of the car, from the ID table 530a of the object database 530 in accordance with the location of the view point detected by the view point movement detection section 521 and the viewing direction detected by the viewing direction detection section 522, and then writing the basic data onto the S table 511a of the data storage section 511.
The display controller 510 further includes a display data calculation section 513 for calculating the display data I' from the basic data D stored in the S table 511a in accordance with the location and the travelling direction of the car which have been detected by the view variation detector 520, and also includes a display control section 514 for controlling the display of the objects on the display 540 based on the display data I' calculated by the display data calculation section 513.
Next, the operation of the car navigation system will be described.
In this case, a road sign OB2 indicating a speed limit of 100 km/h (hereinafter, simply referred to as a "speed-limit sign") and a road sign OB5 indicating no parking (hereinafter, simply referred to as a "no-parking sign") are employed as the objects to be displayed. A display control operation performed by the car navigation system for displaying these road signs OB2 and OB5 as objects on the display 540 will be described below. FIG. 19 shows the road signs OB2 and OB5 which are displayed on the display 540 in various sizes along the movement of the car and a graph .alpha..sub.0 showing the relationship between the normalized sizes of these road signs and the locations of the car.
In the graph shown in FIG. 19, the axis of the ordinates indicates the size .rho. of the road sign object displayed on the display screen, while the axis of the abscissas indicates the distance x from the reference location (i.e., the origin of the coordinate system) and the current location of the travelling car.
As shown in FIG. 19, when the car is located far away from the spot where the road signs OB2 and OB5 are disposed, these road sign objects are displayed in such small sizes that the sign objects OB2.sub.1 and OB5.sub.1 at this point in time are hardly visible to a viewer. However, as the car comes closer to the spot (i.e., x=2.0) where these road signs are disposed, the sizes of these road sign objects displayed on the display screen gradually increase, i.e., OB2.sub.1 .fwdarw.OB2.sub.2 .fwdarw.OB2.sup.S, and OB5.sub.1 .fwdarw.OB5.sub.2 .fwdarw.OB5.sub.S. Finally, once the car has passed the spot in question, the road sign objects are no longer displayed on the display screen. That is to say, OB2 become OB2.sub.0 and OB5 becomes OB5.sub.0.
Next, a display process for varying the display styles of the road sign objects on the display screen in accordance with the movement of the car will be described.
FIG. 20 is a flow chart illustrating this process flow.
In Step S1, the data retrieving section 512 waits for the movement of the view point position or the variation of the viewing direction to be detected by the view variation detector 520. When the movement of the view point position or the variation of the viewing direction is detected, the data retrieving section 512 updates the S table 511a in the display controller 510.
More specifically, the data retrieving section 512 retrieves the basic data of the objects OB2 and OB5 which have been included within the view area at the point in time from the ID table 530a of the object database 530, writes the basic data onto the S table 511a in the display controller 510 and then eliminates the basic data of the objects which have been excluded from the view area at the point in time from the S table 511a (Step S2).
In the case of performing the display control of the road signs as described with reference to FIG. 19, when the car reaches the location where x=1, the basic data D2 and D5 of the speed-limit sign object OB2 and the no-parking sign object OB5 are written onto the S table 511a as the objects which have been included within the view area and the basic data of the other objects are eliminated from the S table 511a.
Next, the display data calculation section 513 calculates the display data I'2 and I'5 of the objects OB2 and OB5 stored in the S table 511a of the data storage section 511 based on the basic data D2 and D5 thereof, in response to the detection output of the view variation detector 520 (Step S3). More specifically, the display data calculation section 513 determines whether or not there are any objects in the S table 511a of the storage section 511 which are yet to be processed for calculating the display data based on the basic data. If there are any objects in question, then the display data calculation section 513 temporarily retrieves the basic data D of the objects from the S table 511a (Step S3a), produces the display data I' by processing the basic data D by predetermined arithmetic processing (Step S3b) and then writes the display data I' onto the S table 511a. When there no longer exist in the S table 511a any objects yet to be processed for calculating the display data I' based on the basic data D, the display control section 514 provides the display data I'2 and I'5 of the respective objects OB2 and OB5 stored in the S table 511a to the display 540 (Step S4).
As a result, the objects OB2 and OB5 are displayed on the display 540 in accordance with the outputs of the view variation detector 520 at the point in time, i.e., the current location and travelling direction of the car.
For example, in the case of performing the display control of the speed-limit sign object OB2 and the no-parking sign object OB5 shown FIG. 19, the road sign objects OB2 and OB5 are displayed on the display 540 in the variable sizes (i.e., OB2.sub.1 .fwdarw.OB2.sub.2 .fwdarw.OB2.sub.S .fwdarw.OB2.sub.0 and OB5.sub.1 .fwdarw.OB5.sub.2 .fwdarw.OB5.sub.S .fwdarw.OB5.sub.0) corresponding to the outputs of the view variation detector 520, i.e., the locations and travelling directions of the car.
Thereafter, it is determined whether or not the display control is to be continued (Step S5). If it is to be continued, the process by the display controller 510 returns to Step S1. On the other hand, if it is not to be continued, the display controller 510 ends the process.
However, when a display control is performed in accordance with a conventional depth cuing method as in the above-described navigation system, the display styles of an object on the display screen are determined depending upon the view variables, e.g., where the view point is located.
In other words, in accordance with the conventional technologies, a display control corresponding to a specific view area determined by the location of the view point and the like is commonly performed with respect to the objects to be displayed. Thus, it is impossible to independently control the display styles of the individual objects on the display screen.
Therefore, in accordance with the conventional technologies, since the depth cuing control must be performed on the basis of the view area, an independent depth cuing control cannot be applied to an individual object in a specific view area. Consequently, in the example shown in FIG. 19, it is impossible to independently control the display styles (or the display sizes) of the speed-limit sign object OB2 and the no-parking sign object OB5. This means that it is very difficult to simultaneously display a large quantity of multi-media data (or objects) effectively.
In order to eliminate such a disadvantage, a method has been developed for independently controlling the display styles of a plurality of objects displayed on the display screen. According to this suggested method, not only basic data but also a flag are set for each object. Even when an object is located within a view area, it is determined based on the value of the flag thereof whether or not the object is to be displayed.
Hereinafter, such a method will be specifically described as being applied to a case where an object to be displayed is a road sign.
In this case, flags associated with the temperature are set with respect to the individual objects to be displayed. For example, if the objects to be displayed are a speed-limit sign, a no-parking sign and "Slippery when wet" sign (hereinafter, simply referred to as a "slip-sign"), the flag of the slip-sign object is assumed to be "1" when the temperature is 0.degree. C. or lower and to be "0" when the temperature is higher than 0.degree. C. The flags of the other road sign objects are assumed to be always "1" irrespective of the temperature.
For example, assuming that the car is now located at a position within a view area where all of the speed-limit sign, no-parking sign and slip-sign objects exist, all the road sign objects are automatically displayed in the case of the above-described conventional depth cuing control method unless the flags have been set. However, in the case where the flag corresponding to the temperature has been set, when the temperature is higher than 0.degree. C., the value of the flag associated with the slip-sign object is "0", so that only the speed-limit sign object and the no-parking sign object are displayed on the display screen.
However, in this method, the flag set for an object is not defined by a continuous function with respect to the temperature. Generally speaking, in a display control method using such a flag, it is not defined by a continuous function with respect to three-dimensional spatial coordinates and other variables whether or not an object existing in a view area is visible (hereinafter, referred to as "object visibility"). For example, when a flag associated with the object visibility is set, if an object is located within a view area, only the visibility of the object is acknowledged, but the display style of the object is invariable. Thus, since such a flag-based display control is a discontinuous one where the flag has only two values of "0" and "1", it is impossible to continuously vary the display styles of an object directly in accordance with the parameters (including the three-dimensional spatial coordinates thereof) and other variables in a view area.
To sum up, in a conventional multi-media data display device, since the display style (or the visual appearance) of an object on a display screen of a display device is controlled based on the relationship between the basic data of the object (i.e., the geometric data and the attributive data specifying the object) and the parameters in the view area, such a device can perform nothing but a very simple display control in accordance with an individual view area.
On the other hand, even in a display control method based on the logical operations of a flag or the like which has been set for an object, as well as the relationship between the basic data and the parameters in a view area, the independent display control for the individual objects is nothing but a discontinuous simple one relying only on the visibility of each of the objects which is represented as one of the two flag values of "0" and "1". Thus, in accordance with such a conventional method, it is impossible to smoothly and flexibly control the display styles of a plurality of objects displayed on the display screen on an object basis.