Electrons are directed from an electron emitter towards a magnetic recording medium to heat a recording portion of the magnetic recording medium and magnetic information is written by a magnetic recording head to the temperature-elevated recording portion. Otherwise, a magnetic head having a magnetic pole is used and the magnetic pole serves as an electron emitter as well. Alternatively, a space between the electron emitter and recording medium is made shorter smaller the mean free path of electrons in the atmosphere to considerably improve the recording density.

The present invention relates to a thermally-assisted recording and/or reproducing device, and more particularly, to an improved and novel thermally-assisted recording device capable of heating a magnetic or other kinds of recording media by electron beams to write and/or read data to the medium with an extremely high density.
Personal computer (PC) systems and audio and/or video (AV) systems require a peripheral storage unit which has a large capacity and also is inexpensive. Currently, most of such peripheral storage units are magnetic or optical recording devices. The magnetic recording devices include a fixed magnetic hard disc drive (HDD) and magnetic tape recording device. Many of the PC systems adopt an HDD and an optical disc drive or magnetic tape recording device. Generally, various data including OS (operating system) and other software are stored in the HDD to which random access is made, while the optical disc drive or magnetic tape recording device is used for long-term storage of important data. Conventionally, the AV systems for storage of a large amount of moving picture information use mainly the magnetic tape recording device as the peripheral storage unit. With the larger capacity of the recent HDD and optical recording device, however, it has become expected that the HDD and optical recording device are employed in the AV systems for their speedy accessibility which is not possible with the conventional magnetic tape recording device. The magnetic and optical recording devices for use in the PC systems and AV systems are required to have a larger capacity and higher speed and be more inexpensive. With the conventional peripheral storage units, however, it is said that problems will arise as in the following.
First, the magnetic recording device will be considered. The magnetic recording device to magnetically write and read information has constantly been evolved as a large capacity, high speed and inexpensive information storage means. Among others, the recent hard disc drive (HDD) has shown remarkable improvements. Specifically, as proved on the product level, its recording density is over 10 Gbpsi (gigabits per square inch), internal data transfer rate is over 100 Mbps (megabits per second) and price is as low as several yens/MB (megabytes). The high recording density of HDD is due to a combination of improvements of a plurality of elements such as signal processing technique, servo control mechanisms, head, medium, HID, etc. Recently, however, it has become apparent that the thermal agitation of the medium inhibits the higher density of HDD.
The high density of magnetic recording can be attained by making smaller the recording cell (recording bit) size. However, as the recording cell is made smaller, the signal magnetic field intensity from the medium is reduced. So, to assure a predetermined signal-to-noise ratio (S/N ratio), it is indispensable to reduce the medium noise. The medium noise is caused mainly by a disordered magnetic transition. The magnitude of the disorder is proportional to a magnetic transition unit of the medium. The magnetic medium uses a layer formed from polycrystalline particles (will be referred to as xe2x80x9cmultiparticle layerxe2x80x9d or xe2x80x9cmultiparticle mediumxe2x80x9d herein). In case a magnetic exchange interaction works between magnetic particles, the magnetic transition unit of the multiparticle layer is composed of a plurality of exchange-coupled magnetic particles.
Heretofore, when a medium is to have the recording density is several hundreds Mbpsi to several Gbpsi for example, the lower noise of the medium has been attained mainly by reducing the exchange interaction between the magnetic particles and making smaller the magnetic transition unit. In the latest magnetic medium of 10 Gbpsi in recording density, the magnetic transition unit is of only 2 or 3 magnetic particles. Thus, predictably, the magnetic transition unit will be reduced to only one magnetic particle in near future.
Therefore, to assure a predetermined S/N ratio by further reducing the magnetic transition unit, it is necessary to make smaller the size of the magnetic particles. Taking the volume of a magnetic particle as V, a magnetic energy the particle has can be expressed as KuV where Ku is an anisotropy energy density the particle has. When V is made smaller for a lower medium noise, KuV becomes smaller with a result that the thermal energy each particle has at a temperature near the room temperature will disturb information written in the medium, which is the xe2x80x9cthermal agitationxe2x80x9d referred to herein and has become the problem as mentioned above.
According to the analysis made by Sharrock et al., the ratio between magnetic energy and thermal energy of a particle, KuV/kT where k is Boltzman""s constant and t is absolute temperature, is required to be greater than 100 or so in order to keep the reliability of the record life. If the particle size is decreased for a lower medium noise with the anisotropy energy density Ku being maintained at (2 to 3)xc3x97106 erg/cc of the CoCr group alloy conventionally used as a magnetic layer in the recording medium, it will be difficult to assure a thermal agitation resistance.
More specifically, the multiparticle layer of Co, Cr, Ta and Pt used in the current magnetic recording medium has a Ku value of about (2 to 4)xc3x97106 erg/cc. With a particle size of 10 nmxcfx86-10 nmt or so, the magnetic energy of each particle will be under 100 times of the thermal energy each particle has at the room temperature and there will take place a noticeable destruction of written information due to the thermal agitation. Improvement of the medium material and increasing the anisotropy energy density Ku may look like an approach to the solution of the problem, but a larger value of Ku will be accompanied by a larger coercive force, which will make the information writing to the medium more difficult.
Recently, magnetic layer materials having a Ku value of more than 107 erg/cc such as CoPt, FePd, etc. have been attracting much attention from all the field of industries concerned. However, simply increasing the Ku value for compatibility between the small particle size and thermal agitation resistance will lead to another problem. The problem concerns the recording sensitivity. Specifically, as the Ku value of the magnetic layer of a medium is increased, the recording coercive force Hc0 of the medium (Hc0=Ku/Isb; Isb is a net magnetization of the magnetic layer of the medium) will increase and the necessary magnetic field for saturation recording increase proportionally to Hc0.
A recording magnetic field developed by a recording head and applied to the medium depends upon a current supplied to a recording coil as well as upon a recording magnetic pole material, magnetic pole shape, spacing, medium type, layer thickness, etc. Since the tip of the recording magnetic pole is reduced in size as the recording density is higher, however, the magnetic field developed by the recording head is limited in intensity.
Even a combination of a single-pole head which will develop a largest magnetic field and a vertical medium backed with a soft magnetic material for example can develop a magnetic field whose largest possible intensity is on the order of 10 kOe (Oe: oersted). On the other hand, to assure a sufficient thermal agitation resistance with a necessary particle size of about 5 nm for a future high-density, low-noise medium, it is necessary to use a magnetic layer material having a KU value of 107 erg/cc or more. In this case, however, since the magnetic field intensity necessary for write to the medium at a temperature approximate to the room temperature is over 10 kOe, no write to the medium is possible. Therefore, if the Ku value of the medium is simply increased, there will arise a problem of the write to the medium being impossible.
As having been described in the foregoing, in the magnetic recording using the conventional multiparticle medium, the lower noise, thermal agitation resistance and higher recording density are in a trade-off relation with each other, which is an essential factor upon which the limit of the recording density depends.
Secondly, the optical recording device will be considered. A high density of the optical recording basically depends upon the reduction of the size of a laser spot focused on an optical recording medium. Therefore, for a higher recording density with the optical recording device, a laser light used should be of a shorter wavelength or an objective lens used should have a higher numerical aperture (NA). However, use of a laser light having a shorter wavelength is limited by selection of a laser element material for use with the laser light and also by the spectral transmittances of the substrate of an optical disc and various optical elements included in the optical system of the optical recording device. Recently, there has been proposed a ultrahigh density optical recording using a near-field light (evanescent wave). For practical use of the near-field light, however, there are many problems to solve since the light spot size and light intensity on the medium are theoretically in a trade-off relation with each other.
Therefore, it is predicable that in organizing a future peripheral storage unit having a recording density of over Tb (terabits)/inch2, both the conventional magnetic and optical recording systems will encounter many difficulties.
Accordingly, the present invention has an object to overcome the above-mentioned drawbacks of the prior art by providing a magnetic recording device having a novel construction based on a different principle from that for the conventional magnetic recording devices and capable of recording at a dramatically high density.
The present invention has another object to provide an electron beam recording device capable of solving the thermal agitation problem in the magnetic recording and trade-off problem related to the near-field light used in the optical recording to break through the recording density limit of the conventional peripheral storage units.
The Inventors of the present invention propose a thermally-assisted magnetic recording device based on a novel concept to attain the above object. In this thermally-assisted magnetic recording device, magnetic particles so fine that noise therefrom is sufficiently small are used and a recording layer having a high anisotropy energy density (Ku) at a temperature near the room temperature is used to assure a thermal agitation resistance. In a medium having such a large Ku value, since the magnetic field intensity necessary for recording exceeds the intensity of a magnetic field developed by the recording head when the ambient temperature is near the room temperature, no recording is possible. However, by locally heating the recording medium by any means, the coercive force Hc0 of the temperature-elevated portion of the medium can be reduced to below the magnetic field intensity of the recording head to write information to the medium.
The recording medium may be heated by irradiating light beam to near the recording magnetic pole. By locally heating the medium with the light beam during recording, the Hc0 value of the temperature-elevated portion of the medium can be reduced to below the intensity of the magnetic field developed by the recording head, thereby permitting to write information to the medium.
When a light beam from a conventional light source is used as a heat source, however, since the size of light spot is defined by the diffraction limit, an area of several hundreds of nm or more will be heated. Thus, use of such a light beam is not suitable for a future magnetic recording in which the track width will be 100 nm or less. Also, a near-field light may be used in order to limit the light beam to less than the diffraction limit. However, a near-field light emitted from a conventional light source cannot be used efficiently and the reduction in area of the temperature-elevated portion and light beam power are in a trade-off relation with each other, thus no sufficient heating can be assured in a recording at a high density.
That is, in the modality in which a far-field light is used as a heat source, the light spot size is defined by the diffraction limit, so no heating of a fine area is possible. On th other hand, the near-field light cannot be used with a high efficiency, and thus sufficient heating is difficult in a higher density of recording.
To avoid the above problem, the present invention uses an electron beam as a heat source.
Namely, the above object can be attained by providing a thermally-assisted magnetic recording device including, according to the present invention, an electron emission source of electron emitter and a magnetic recording head, electrons being directed from the electron emitter towards the magnetic recording medium to heat a recording portion of the magnetic recording medium and magnetic information being written to the temperature-elevated recording portion by the magnetic recording head applying the recording magnetic field to the magnetic recording medium. The electron beam can be limited very easily to a very fine spot size, whereby the recording density can considerably be improved.
In the above thermally-assisted magnetic recording device according to the present invention, the electron emitter can heat the magnetic recording medium so that the coercive force of the recording portion of the magnetic recording medium will be smaller than the intensity of the recording magnetic field developed at the recording portion by the magnetic recording head. Thus, positive recording is possible to a recording medium having a large coercive force.
Also in the above apparatus, the recording portion of the magnetic recording medium has a larger coercive force than the intensity of the magnetic field developed by the magnetic recording head, at the normal temperature. This magnetic recording medium is strong against the thermal agitation and the size of recording cells can be made rather smaller than the recording cell size in the conventional magnetic recording medium.
Further, in the above apparatus, there is provided a driving mechanism to move a recording surface of the magnetic recording medium in relation to the electron emitter and magnetic recording head, and after the magnetic recording medium is moved by the driving mechanism, the electron emitter will come nearer to a leading position in relation to the recording surface than the magnetic recording head. Thus, it is possible to positively elevate the temperature of the recording portion of the magnetic recording medium prior to recording.
Also in the above apparatus, the electron emitter includes a plurality of electron emitters disposed along the direction of the movement thereof by the driving mechanism. Thus, the recording portion of the magnetic recording medium can positively be heated.
Moreover in the above apparatus, there are formed on the magnetic recording medium a recording track parallel to the moving direction; the length Te of the electron emitter in the width direction of the recording track and length Tw of the magnetic recording head in the width direction of the recording track are in a relation of Te/2xe2x89xa6Twxe2x89xa62Te with each other.
Moreover in the above apparatus, the electron emitter emits electrons by field emission. Thus, fine electron beam can positively generated, and the electron emitter has an improved reliability and operating life.
Also in the above apparatus, the electron emitter is placed in a non-oxidizing atmosphere or depressurized atmosphere. Thus, the electron emitter has a further improved reliability and service life.
In the above respect, the oxygen partial pressure density X (in mols/cm3) and emission electron current density J (in A/cm2) of the electron emitter are in relations of Xxe2x89xa61.25xc3x971012xc3x97J and Jxe2x89xa6104 with each other.
In the thermally-assisted magnetic recording according to the present invention, an electron emitter is used as a heat source. The electron emitter may be any of various types such as field emission type, thermoelectronic emission type, photoemission type, tunnel electron emission type, etc. The xe2x80x9cfield emission typexe2x80x9d is such that by providing a high potential gradient (electric field) on an electron emission surface, electrons are directly emitted from the surface. The present invention adopts a field emission type electron emitter. In this case, since the electron emission area is on the order of 10 nm, an area of about 10 nm of the medium can easily be heated, thus the present invention can attain a resolution much better than that of the conventional method using the light beam. Also in case an electron emitter of the thermoelectronic emission type is used, however, the nearly same effect can be assured by converging the electron beam to a predetermined size.
Normally, the electron beam is used under a vacuum. However, taking in consideration the facts that the spacing between the magnetic head and medium is several tens of nm or less and this spacing will further be reduced in future and that the mean free path of electrons at 1 atm. is on the order of 150 nm which is sufficiently longer than the spacing between the magnetic head and medium, it can be said that emitted electron beam can be directed towards the medium with no collision. Namely, the electron emitter can be installed in a magnetic recording device which is to be used at normal atmospheric pressure.
Note that the mean free path of electrons depends upon the type of gas and electron energy. However, in case the gas used is a nitrogen being one of the major elements of air, the mean free path of electrons will be shortest even when the electron energy is 2 eV or so. The mean free path, in the nitrogen at atmospheric pressure, of the electron having the energy of 2 eV is 150 nm. Also, in case the gas used is oxygen being another major element, the mean free path of electrons is shortest when the electron energy is on the order of 20 eV. However, the mean free path is 300 nm or more, which is long enough as compared with the above-mentioned spacing.
Further, when the electron beam is used in a depressurized atmosphere according to the present invention, the probability of collision before an electron beam is incident upon the medium can be said to be rather low. Also, in case the gas used is an inert gas atmosphere according to the present invention, when it is a dry nitrogen, the mean free path of electrons is a minimum of 150 nm or so as in the above. When a rare gas such as Ne, Ar, Kr or Xe is used, the minimum value of mean free path of electrons at 1 atm. is 1000, 160, 130 or 94 nm, which is long enough as compared with the above spacing. The electrons can be incident upon the medium with little collision.
An inert gas atmosphere at a substantial atmospheric pressure should preferably be charged in the recording device for a longer service life of the electron emitter. When dry nitrogen is used as the inert gas, the mean free path of electrons is a minimum of 150 nm or so. Also when a rare gas such as Ne, Ar, Kr or Xe is used, the mean free path of electrons is long enough as in the above. In case, with the spacing between the magnetic head and medium being of several tens of nm, the electron beam can substantially work as under a vacuum. In this way, use of the dry nitrogen or rare gas atmosphere can permit a stable performance of the electron beam.
Also, the pressure of the atmosphere in which the electron beam is used may be near, higher or lower than 1 atm. However, a pressure of the atmosphere being at a substantial atmospheric pressure is convenient from the practical viewpoint.
On the assumption that the pressure inside the apparatus is P (in Torr), the minimum value of the mean free path of electrons at 1 atm. is xcexmin (in nm) and the spacing between the electron emitter and medium is d (in nm), the present invention should desirably meet the following condition:
d less than xcexminxc3x97(760/P)
The minimum value of mean free path of electrons xcexmin is defined to a mean free path over which there will take place no collision with a probability of 1/e (e is a base of natural logarithm) when the electron travels over the distance of xcexmin. That is, when the condition d less than xcexminxc3x97(760/P) is met, the electron will collide with molecules with a probability of about 63% in the course since it is emitted until incident upon the medium. More preferably, the following condition should be met:
d less than (⅓)xc3x97xcexminxc3x97(760/P)
When the above condition is met, the collision probability can be reduced to less than xc2xd. It is more desirable to use a coefficient of ⅕ in place of the coefficient of ⅓ in the above expression. With this coefficient, the collision probability can be reduced to so small a value as will not be inconvenient in practice.
The pressure P inside the apparatus falls within a substantial range of the atmospheric pressure. Within a range meeting the above condition, it may be selected depending upon whether a practical apparatus is feasible with the lower limit of the pressure P. If the pressure inside the apparatus is different from the atmospheric pressure or if the apparatus is charged with a gas different from the atmosphere, a hermetic enclosure is required.
In case the hermetic enclosure is used, the lower limit of the pressure P depends upon the mechanical strength of the enclosure as the case may be. In case of the conventional electron beam recording device under a vacuum, since the enclosure is applied with a pressure as high as 1 kg/cm2, it is not easy to assure a sufficient mechanical strength of the enclosure and also to maintain the vacuum state.
According to the present invention, however, the lower limit of the pressure P can be selected depending upon the practically allowable pressure to the enclosure and vacuum sealing of the enclosure. Since the lower limit of the pressure P should be considered in designing the enclosure, it cannot be fixed to a general value. However, a half or so of the atmospheric pressure may be reasonable. When the lower limit of the pressure P is higher than the half of the atmospheric pressure, the pressure applied to the enclosure will be 0.5 kg/cm2 or so and the sealed or hermetic extent of the enclosure may be a sealing provided by the ordinary aluminum sash for example.
The upper limit of the pressure P is basically defined by the above expression. The practical upper limit is double the atmospheric pressure or so based on the same consideration to the lower limit. The xe2x80x9csubstantial atmospheric pressurexe2x80x9d referred to herein is as having been described in the foregoing.
Now, the electron emitter of the field emission type will be considered. The electron emission area of this source depends in size upon the applied electric field and shape of the electron emitter. The size of the electron emission area is on the order of 10 nm when the electric field is 106 to 107 V/cm and the electron emitter has a sharpened or tapered shape obtained by a selective etching or whose end curvature is several tens of nm or less. This size is difficult to realize with a light beam and the electron emitter should preferably be applied to a future magnetic recording device in which recording cell size is several tens of nm. Emission current depends on the applied electric field. With an electric field of 106 to 107 V/cm, an emission current of about 10xe2x88x926 to 10xe2x88x924 can be obtained from an area of 10 nm in diameter.
Note that the emission current is nearly proportional to the square of the intensity of applied electric field according to the Fowler-Nordheim expression. Therefore, if the electric field intensity is 3.3xc3x97107 V/cm for example, the emission current can be 10xe2x88x923 A. Although an electric field intensity of 106 to 107 V/cm may seem to be very high, it will be suitably applicable to the magnetic recording device since the voltage to be applied between the electron emitter and medium is a maximum of several volts to several tens of V because the above spacing is several tens of nm.
Next, the mechanism of heating of the medium by electron beam will be described. When a voltage of 10 V is applied (with the spacing being 10 nm and field intensity being 107 V/cm), an emission current of 10xe2x88x924 A will provide a power of 10xe2x88x923 W. When a voltage of 33 V is applied (with the spacing being 10 nm and field intensity being 3.3xc3x97107 V/c), an emission current of 10xe2x88x923 A will provide a power of 3.3xc3x9710xe2x88x922 W. When this power is applied to a square area on the medium, whose one side is 10 nm long, the power density will be 109 W/cm2 or 3.3xc3x971010 W/cm2. When 10 m/s is used as a practical linear velocity (moving speed of the medium in the direction of the recording track) in the magnetic disc drive, the medium takes a time of 1 ns for passing by the heated area of 10 nm. Therefore, the energy density applied to the square area whose one side is 10 nm long will be 1 J/cm2 or 33 J/cm2. It will be considered herebelow whether this value is adequate for heating the medium.
As an example of the heating mechanism using an electron beam, there is available a heating mechanism in which the electron beam behaves as de Broglie wave to heat the medium. The de Broglie wave is on the order of 0.4 nm when the electron energy is 10 V while it is about 0.2 nm when the electron energy is 33 V. Namely, it is equal to the atom size, so a lattice vibration (heating) can be generated. Alternatively, there may be available a mechanism in which an electron beam having such an energy is incident upon the medium to oscillate and excite the plasmon, and an energy emitted when the plasmon-oscillated electron and positive hole in pair are recombined is given to a phonon, namely, to a lattice to induce a lattice vibration, that is, a heat.
The power density or energy density necessary for heating the medium can be considered to be nearly equal to that used with the optical disc. So, if the above power density 109 W/cm2 or 3.3xc3x971010 W/cm2, or energy density 1 J/cm2 or 33 J/cm2, is equal to or larger than the power density or energy density used with the optical disc, the medium can be heated sufficiently with the electron beam. In a common phase-change disc, for example, a linear velocity of 6 m/s, full width at half maximum (FWHM) of 0.6 xcexcm of the light spot and a recording power of 10 mW will permit to heat this medium to a higher temperature than its melting point (600xc2x0 C.). Since the medium takes a time of 100 ns for passing by the full width at half maximum and the area of the light spot is 0.28xc3x9710xe2x88x928 cm2, the power density will be 3.5xc3x97106 W/cm2 and energy density will be 0.35 J/cm2. Therefore, it can be said that the medium can sufficiently be heated by the plasmon oscillation with a energy density of 1 JIcm2.
In addition, there can take place a Joule-heating mechanism in which the electron beam causes a current to flow through the medium which is thus heated by the Joule-heating. This mechanism will coexist with the above-mentioned plasmon-oscillation heating mechanism. Comparison with the power density used with the optical disc will lead to the understanding of the reason why the Joule-heating mechanism is suitable for heating the medium. Specifically, when a current of 10xe2x88x924 A or 10xe2x88x923 A is supplied to a square area whose one side is 10 nm long of the medium in the direction of the layer thickness, the heating power will be Rxc3x9710xe2x88x928 W or Rxc3x9710xe2x88x926 W where R is a resistance of the medium. When the resistivity of a magnetic recording medium or magneto-optical recording medium is (5 to 6)xc3x9710xe2x88x926 xcexa9cm, the area of current path is 10xe2x88x9212 cm2 (10 nm square) and the current path length, namely, magnetic layer thickness is 2xc3x9710xe2x88x926 cm (20 nm), the resistance of the medium will be 10 Q or so. Therefore, the heating power will be 10xe2x88x927 W or 10xe2x88x925 W. Division of this heating power by the heated area of 10xe2x88x9212 cm2) provides 105 W/cm2 or 107 W/cm2. Since the time of current supply is different from the time of electron beam incidence, the Joule-heating mechanism should be considered by comparison in power density, not in energy density. Thus, it can be said that the current of 10xe2x88x924 A will be somewhat insufficient, but 10xe2x88x923 A will enable a sufficient Joule heating.
Actually, there will take place together, as mentioned above, the process in which the medium is heated by the plasmon oscillation and excitation and the process in which the medium is heated by the Joule heating due to the current supply to the medium. In any of the above processes, the power density and energy density are sufficient. Therefore, any of these heating mechanisms may be selected for use in the thermally-assisted magnetic recording device according to the present invention.
The thermally-assisted magnetic recording head according to the present invention should preferably be embodied as a one in which an electron emitter and recording magnetic pole are disposed in this order from the downstream (leading) side in the direction of the medium movement. Owing to this arrangement, a recording magnetic field can be applied to the medium at a position where Hc0 has become sufficiently low immediately after the medium is heated by the electron beam. The distance between the electron beam incident position and recording magnetic field-applied position depends upon the thermal response of the medium as well, but should preferably be 100 nm or less, and more preferably be several tens of nm or less.
For a higher efficiency of the heating, a plurality of electron emitters in the electron emitter should be disposed in the direction of the recording track. The size of the heated area should preferably be nearly equal to the width of the recording track to enable a uniformmagnetic transition over the trackwidth. Also the track width Te of the electron emitter, and track width Tw of the recording head should desirably meet the condition of Te/2xe2x89xa6Twxe2x89xa62Te.
The inside of the ordinary magnetic disc drive communicates with the ambient atmosphere. When the electron beam is to be used in an atmosphere containing oxygen and moisture, consideration should be given to the life of the electron emitter as well as to the mean free path of electrons. At atmospheric pressure, air molecules or water molecules in the atmosphere will be adsorbed by the electron emitter and will possibly shorten the service light of the latter. Different from the conventional thermal emission type electron beam emitter and photo emission type electron beam emitter, the field emission type electron beam emitter having actively been researched and developed recently is extremely resistant against adsorbed molecules. When carbon (C) is used as a material for the electron emitter, the latter will be less influenced by the oxidation. For a practically long service life of the electron emitter, however, the densities of the gas atmosphere near the emitters, especially, the densities of oxygen, water and their dissociated species, and the frequency of their incidence upon the emitters, should be kept low.
The Inventors of the present invention made many experiments mainly on STM (scanning tunneling microscopy) emitter, and found from the experiment result a emitter-surrounding atmosphere required for obtaining a field emission current stably. As will further be described later concerning the embodiments of the present invention, the Inventor of the present invention found that it depends upon the emitter material how the emitter-surrounding atmosphere should be and that also when silicon (Si) on which a surface oxide film is easy to develop was used, electrons could be emitted stably if the density X (mols/cm3) of oxygen molecules in the emitter-surrounding atmosphere and current density J (in A/cm2) of electrons emitted from the emitter met the condition of Xxe2x89xa61.25xc3x971012xc3x97J with Jxe2x89xa7104. The definition of the range of J as in the above condition is intended to present a necessary range of J for significantly heating the medium. There will be no sense in defining an emission current with which no significant heating will take place or a relation between X and J which would be when the emitter stops operating.
When the emitter stops operating, a natural oxide layer or a physical adsorption layer will develop on the emitter surface. When the above defined condition in the present invention is met, such layers will easily desorb the emitter surface due to the following operation of the emitter. The above definition of the relation between X and J in the present invention is intended to present a condition under which so long as an emission current capable of significantly heating the medium is supplied, the tip of the emitter will not be deteriorated due to attack by oxygen. The relation between X and J has a physical meaning that while a hundred electrons are being emitted from the emitter, one oxygen molecule will be incident upon the emitter surface. With such an extent of the incidence of oxygen molecule, heating of the emitter surface by the electron emission, etc. will allow the incident oxygen to re-desorb the emitter surface which will thus not be deteriorated, which is one of the findings of the above Inventors"" experiments.
As having been described in the foregoing, according to the present invention, a low-noise multiparticle medium formed from very fine particles, necessary for a high density magnetic write and read, can be made to have a sufficiently high resistance against the thermal agitation at a temperature near the room temperature, and the coercive force of the medium, that is, a necessary magnetic field for a magnetic transition, is reduced by incidence of an electron beam upon a portion of the medium to which a recording magnetic field is applied, to thereby enabling a practical recording head to attain a high speed of recording.
Also, according to the present invention, an electron emitter and write and read elements are formed integrally with each other to provide a compact and lightweight thermally-assisted magnetic recording head, which will enable a high speed seek operation and inexpensive head and drive.
Further, according to the present invention, it is possible to improve to a practical level the service life of the electron emitter of a thermally-assisted magnetic recording device in which a medium is heated by a high resolution, high efficiency electron emitter, the coercive force of the heated portion of the medium is reduced and a recording magnetic field is applied to the portion whose coercive force has thus been reduced, thereby recording information to the medium.
On the other hand, according to the present invention, a magnetic pole or magnetic yoke can also be used as an electron emitter, thereby enabling a magnetic write and read with a further high recording density.
Also according to the present invention, an electron emitter having an extremely superior recording resolution to that of the light beam or magnetic recording head used in the conventional magnetic recording device, can be used to write information to a medium. Thus, according to the present invention, there can provided a practical magnetic recording device in which information can be recorded with a considerably improved density and an electron beam recording can be done in the atmosphere, which is impossible with the conventional electron beam recording.
That is, according to the present invention, there can be provided a thermally-assisted magnetic recording device realizing a new concept that information can be recorded with a drastically higher density than with the conventional recording device. Thus the present invention is very advantageous in the field of art.
These objects and other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention when taken in conjunction with the accompanying drawings. It should be noted that the present invention is not limited to the embodiments but can freely be modified without departing from the scope and spirit thereof defined in the claims given later.

Thermally-assisted magnetic recording and reproducing device having an electron beam thermal source


Disclosed is a manufacture method of the thin film transistor array, comprising depositing a first transparent conductive layer and a first metal layer to perform patterning for forming a common electrode, a gate electrode and a transparent electrode array; depositing an insulating layer, an active layer, an ohmic contact layer and a second metal layer to perform patterning for forming a source and a drain; depositing a second transparent conductive layer to perform patterning for forming a source contact layer, a drain contact layer and a pixel electrode array connected to the drain contact layer. The present invention simplifies the manufacture process, saves the cost and time for the manufacture.

1. Field of the Invention
The present invention generally relates to a semiconductor manufacture field, and more particularly to a manufacture method of a thin film transistor array substrate.
2. Description of Prior Art
LCD (Liquid crystal display) panel is one of the main components of a LCD. The present TFT-LCD panel provides advantages of low power consumption, small size structure and no radiation and therefore is widely applied in a liquid crystal display.
TFT-LCD comprises a thin film transistor array substrate and a color film substrate which the liquid crystal is positioned therebetween. Mainly, the manufacture of the thin film transistor array substrate is proceeded by performing photo-mask processes to form the necessary patterns for forming thin film transistor elements and the corresponding layout. Several photo-mask processes are required to complete the manufacture of the thin film transistor array substrate because the thin film transistor elements and layout on the glass substrate comprises multiple layers. Through developments and improvements of the technologies, a skill of forming an IPS (In-Plane switching) type LCD with four photo-mask processes has been proposed and achieved today.
FIG. 1 depicts a planar construction diagram of a thin film transistor array substrate of an IPS type LCD according to prior art. FIG. 2 depicts a sectional view diagram along the III-III′ line and the IV-IV′ line shown in FIG. 1.
Please refer to FIG. 1 and FIG. 2 for illustrating the skill of forming an IPS (In-Plane switching) type LCD with four photo-mask processes. First, a conductive metal layer is deposited on a lower substrate 80 and a scan line 81 and a gate electrode 81a is formed by performing patterning to the conductive metal layer. A common line 81b is formed at the same time as the scan line 81 is formed. Multiple transparent electrodes 81c are connected to the common line 81b. After that, an insulating layer 82 is deposited over the entire surface of the lower substrate 80 comprising the scan line 81. A semiconductive layer is formed on the insulating layer 82 and then patterning is performed to form an active layer 83 on the gate electrode 81a. Then, another conductive metal layer is deposited over the entire surface of the lower substrate 80 which the active layer 83 has been formed thereon and then patterning is performed to form data lines 84_1, 84_2, 84_3 and 84_4. Meanwhile, a source 84a and a drain 84b are formed at the same time. A protective layer 85 is deposited over the entire surface of the lower substrate 80 and a contact hole is configurated to reveal the drain 84b. Last, a transparent conductive metal is deposited on the protective layer 85 and patterning is conducted to the transparent conductive metal to form a pixel electrode 87 contacting the drains 84b via the contact hole 86. At the same time while the pixel electrode 87 is formed, a storage capacitor 88 is formed on the protective layer 85 above the common line 81b.
As aforementioned, the skill of forming an IPS (In-Plane switching) type LCD with four photo-mask processes remains the complexity, the manufacture difficulty and higher manufacture cost and the manufacture difficulty level is increased. Consequently, there is a need to provide a manufacture method of a thin film transistor array substrate for solving the existing problems in prior arts.

Manufacture method of thin film transistor array substrate

Shenzhen China Star Optoelectronics Technology Co., Ltd.


Electronic circuit for dimension-measuring device with magneto-resistive electrodes supplying at least one feed voltage for feeding a network of magneto-resistive electrodes and a measuring circuit comprising two differential inputs connected to the network. The measuring circuit uses a rough counter and a fine interpolation circuit for determining from the two sinusoidal input signals received the position of the sensor along the scale. The feed circuit periodically reduces the supplied electric feed voltage so as to temporarily lessen the dissipation of energy in the magneto-resistive electrodes.

The present invention concerns a dimension-measuring device with magneto-resistive electrodes, and a method for measuring dimensions by means of such a device.
Electronic devices for measuring length or angular position in industry for example must generally satisfy several partially contradictory requirements. They must furnish sufficient precision and resolution and be usable in environments subject to vibrations or to pollution such as dust, oil or humidity. Also expected of such sensors are easy integration into small-size apparatus, without significant adjustment or adaptation, high-speed measurement and low power consumption at the lowest possible cost.
Different types of measuring devices, based upon different physical principles, have been developed to satisfy these various requirements. In particular, measuring systems utilizing capacitance variations caused by the movement of a sensor opposite a scale have been used abundantly in portable devices such as calipers for example. These devices must be kept clean enough to function and are thus poorly adapted to operating in an environment that is humid or subject to the spraying of lubricant or cutting oil for example. Devices for measuring length based upon the principle of magneto-resistive electrodes have been proposed, for example in patent document DE4233331 (IMO), that offer much greater resistance to soiling. The device described in this document comprises a sensor provided with a network of magneto-resistive electrodes connected so as to define two Wheatstone bridges. The sensor is mounted on a slide and can be moved opposite a magnetized scale with a magnetization period xcex. Movement of the sensor opposite the scale causes a modification of the magnetic field applied on the various magneto-resistive electrodes of the sensor and thus a change in their resistance. By applying a voltage to the Wheatstone bridges, one gathers at their outputs an electric signal being a periodic function of the position of the sensor along the scale.
The two Wheatstone bridges are constituted of four magneto-resistive electrodes phase-shifted by xcex/2. The corresponding electrodes of each bridge occupy positions phase-shifted by xcex/4. The electrodes of the two measuring bridges are intermixed. The aforementioned document further suggests the use of barberpole structures, which allow the direction of the current vector I to be modified. As the resistance of a magneto-resistive electrode is a function of the angle between the magnetization vector and the current vector, the barberpole structures make it possible to control the direction and amplitude of the variation in resistance of the electrodes caused by the movement of the sensor.
Each branch of the Wheatstone bridge is constituted of a single magneto-resistive electrode whose width must be sufficient to react to the relatively small magnetic fields generated by the scale. The resistance of the branches of the bridge is thus reduced, and substantial currents circulate across the measuring bridges. The power consumption of this device is consequently high.
The patent document U.S. Pat. No. 5,386,642 (Heidenhain) describes a sensor in which the electrodes are organized into measuring bridges, each branch of which is constituted of several magneto-resistive electrodes of the same phase and connected in series. The resistance of the branches of the bridge is thus greater, which allows the power consumption to be appreciably reduced. However, the consumption of this type of sensor remains too high to contemplate its use in electrically autonomous apparatus, for example in portable precision calipers.
The patent document JP-01-212313-A describes an electronic circuit capable of being used in a dimension-measuring device with magneto-resistive electrode, in which the magneto-resistive electrodes are fed with continuous power supplies.
The patent document JP-A-61-173113 describes a new way of connecting the magneto-resistive electrodes in a device for measuring angular dimension, in order to reduce the power consumption. The reduction in consumption is due to a particular connection of the electrodes.
Document EP0924491, the content of which is hereby incorporated by reference, describes an electronic circuit for a dimension-measuring device of the magneto-resistive type, in which the feeding of the measuring bridges is periodically reduced or interrupted, so as to lessen the dissipation of energy in the magneto-resistive electrodes. By feeding the measuring bridges with a cycle ratio of 1/n, it is thus possible to divide by n the electric consumption in the electrodes.
This circuit also describes a standby-mode circuit enabling the electric consumption to be reduced when the device is not used. In stand-by mode, the display and circuit controller are switched off, the reading of the measurement is thus impossible. These components are then reactivated when a movement of the sensor is detected by means of the magneto-resistive electrodes that must remain under tension.
The standby mode described in EP0924491 is thus not very advantageous, since the device in standby is unusable for displaying measurements but nevertheless continues to use considerably current for feeding the magneto-resistive electrodes.
An aim of this invention is to realize a measuring device with magneto-resistive electrodes different from the prior-art devices and having an electric consumption that is equal or lower.
In particular, an aim of the present invention is to realize a portable measuring such as a battery-powered slide caliper.
According to the invention, these aims are achieved by means of a circuit having the elements of the independent claim, alternative embodiments being furthermore indicated in the dependent claims.

Measuring device with magneto-resistive electrodes, and measuring method


A product in the form of a segmented strip includes tabs to assist in dispensing individual segments from the strip. Segments of the strip are separated by lines of perforations running transverse to the strip. A tab of sufficient size to be easily grasped is adhesively secured to the strip across the line of perforations. The tab is positioned so that less than half of the area of the tab is disposed on the segment that is the first to be dispensed. The majority of the surface of the tab is disposed on a segment that will be subsequently dispensed. When the first segment is dispensed, the tab is retained on the next segment since the adhered surface on the next segment is greater. The exposed portion of the tab may then be readily located and grasped when the next segment is to be dispensed.

1. Field of the Invention
This invention relates generally to the field of product packaging. More specifically, the invention relates to a pull-tab to assist in dispensing a product comprising a segment of an elongated strip, which may be packaged in a roll.
2. Background
Conventional self-adhesive bandages are typically packaged individually in a paper wrapper. Frequently, it is difficult to remove the bandage from the paper wrapper, remove the release liner from the adhesive and apply the bandage, especially in urgent care situations. A roll dispenser for self-adhesive bandages has been proposed to make the process of dispensing and applying a bandage more convenient. An example of such a dispenser is shown and described in U.S. Pat. No. 5,782,786.
A problem with adhesive bandages dispensed from a roll, which is a problem shared by many other products dispensed in a similar manner, is locating and grasping the end of the roll in order to dispense the next bandage. Typically, the consumer must feel around the circumference of the roll to locate the end of the roll and then lift the end with a fingernail. Various tab arrangements have been proposed in a context of other products to facilitate finding and lifting the end of a rolled adhesive product. Such arrangements are shown, for example, in U.S. Pat. Nos. 4,512,462; 4,727,616 and 6,014,788.
The present invention provides an improved tab to assist in dispensing a product from a segmented strip of such products. Segments of the strip are separated by lines of perforations running transverse to the strip. A tab of sufficient size to be easily grasped is adhesively secured to the strip across the line of perforations. The tab is positioned so that less than half of the area of the tab is disposed on the segment that is the first to be dispensed. The majority of the surface of the tab is disposed on a segment that will be subsequently dispensed. When the first segment is dispensed, the tab is retained on the next segment since the adhered surface on the next segment is greater. The exposed portion of the tab may then be readily located and grasped when the next segment is to be dispensed.


A method of treating an aqueous solution comprises forming a treatment stream comprising a condensable material. The treatment stream is introduced to an aqueous solution comprising water and a solute to fractionally precipitate the solute out of the aqueous solution and form a solids stream comprising the solute and an aqueous liquid stream comprising at least one solute-depleted solution of the water and the condensable material. The condensable material of at least a portion of the aqueous liquid stream is separated from the water of the at least a portion of the aqueous liquid stream to at least partially reform the treatment stream and form an aqueous liquid product stream depleted in the solute. Aqueous solution treatment systems and additional methods of treating an aqueous solution are also described.

Current and emerging industries are anticipated to require intensification of water usage, which demands obtaining more water from existing water withdrawals. The more intensely water is used, the higher the total dissolved solids (TDS) in the resulting byproducts (e.g., byproduct brine). Brine disposal, in particular, is often about 80 percent of the cost for many water treatment processes that create brines exceeding regulatory TDS discharge limits. Conventional disposal pathways for waste brine include deep well injection or landfilling solids after water has been removed using a crystallizer or evaporation pond. However, crystallizers and evaporation ponds often suffer from energy inefficiencies and significant footprint and maintenance requirements. In addition, it is unlikely that current commercial TDS removal or concentration technologies, including those used for more dilute conditions, can be significantly enhanced to meet an aggressive levelized cost of water (LCOW) treatment needed for wide scale deployment of zero liquid discharge (ZLD) processes.
Accordingly, there is a need for new aqueous solution treatment systems and processes that are fundamentally different than conventional technologies.

Methods and systems for treating an aqueous solution


A tester for in situ testing of a plurality of circuit breakers having a range of rated currents and multiple trip functions, includes a plurality of power resistors of known impedance, an electronic switch associated with each power resistor connecting the resistor in series with the load terminal of the circuit breaker under test, and a controller that turns on a number of the switches selected to collectively draw through the associated power resistors a test current that is a function of the rated current and sufficient to trip the circuit breaker within a selected time window. Turn on of the electronic switches is also controlled to generate a current waveform appropriate for the trip function being tested. In a self test mode, the value of each of the power resistors is verified as being within limits.

1. Field of the Invention
This invention relates to equipment for testing in situ the trip functions of circuit breakers which may have a range of rated currents and more than one trip function.
2. Background Information
Circuit breakers in some applications are tested periodically to assure reliability. This is particularly so in aircraft electrical systems. It is preferable that the circuit breakers be tested in their installed state. The job is made more difficult by the high density of these very small circuit breakers and the fact in any one aircraft system, the breakers can have a range of current ratings. Furthermore, aircraft circuit breakers are now being offered with multiple trip functions.
There is a need for an improved circuit breaker tester that is portable for use in situ testing of circuit breakers, and particularly, installations with circuit breakers having a range of current ratings and even multiple protection functions.
This need and others are satisfied by the invention which is directed to a tester for testing a plurality of circuit breakers each having a designated rated current within a range of rated currents. The tester includes a plurality of load elements each having a known fixed impedance. An electronic switch associated with each load element when turned on connects the associated load element in series with the load terminal of a circuit breaker under test and in parallel with any other load elements connected in series with the load element. A controller turns on a number of the electronic switches selected to collectively draw through the associated load elements a combined test current selected as a function of the designated load current for the circuit breaker under test and sufficient to trip the circuit breaker. The controller turns on the electronic switches in a pattern that draws current through the circuit breaker under test at an amplitude appropriate for the rated current of that circuit breaker and with a waveform appropriate for the protection function being tested. For example, for testing circuit breakers having a delayed trip function and an arc fault function, the controller turns on a first number of the electronic switches for the delayed trip function and a second number of the electronic switches for the arc fault protection function thereby providing separate reference values for the two different trip functions. For circuit breakers in ac electrical systems, the controller can turn on the appropriate number of electronic switches on just some half cycles to test the arc fault protection function, for instance, in the case where the circuit breaker detects arc faults by recognizing gaps in current due to the arcing. In a preferred embodiment of the invention, the controller includes a full wave rectifier so that the current through the load elements is dc. In this case, a zero crossing detector synchronizes turning on of the electronic switches with half cycles of the ac.
The controller includes an indicator means indicating the results of the test. Preferably, the controller includes a power supply connected to the line terminal of the circuit breaker under test so that the indicator is an electrically energized indicator which will operate even with the circuit breaker tripped. The controller also monitors the voltage on the load terminal and includes an arming means which is only activated when the voltage on the load terminal is not substantially zero, indicating that the circuit breaker to be tested is closed.
The controller includes means for indicating test failure if the circuit breaker under test does not trip within a selected time window, beginning a predetermined time after the test is initiated. This includes means indicating failure when the voltage on the load terminal of the circuit breaker under test goes to substantially zero before the selected time window opens or the voltage on the load terminal remains sufficient to indicate that the circuit breaker is still closed after the selected time window closes.
The controller also has a test mode for testing the tester. This includes means testing the impedance of the load elements. The self-testing means includes means checking that the voltage on the load terminal of the circuit breaker under test is not substantially zero, means sequentially turning on one electronic switch at a time, and means checking that the voltage across the associated load element remains within a selected range.

Tester for a plurality of circuit breakers having a range of rated currents and multiple trip functions


Computerized eyewear and corresponding methods measure a wearer's heart rate using a first optical sensor and a second optical sensor at least partially embedded in an eyewear temple. The first optical sensor transmits a first signal to a temple of the wearer and the second optical sensor transmits a second signal to the temple of the wearer. Reflections of the first signal are used to measure a raw heart rate delta and reflections of the second signal are used to measure a noise delta. The raw heart rate delta and the noise delta are used to determine a measured heart rate of the wearer of the computerized eyewear.

Heart rate detection and monitoring is an important process for many individuals. Heart rate monitoring can be desirable for both medical and fitness purposes. Individuals with medical issues related to the heart need to closely monitor their heart rates to ensure that the results do not fall outside of a prescribed range. Similarly, many individuals wear heart monitors while working out or participating in sports. Doing so allows the individual to alter their activity to optimize their heart rate for providing the maximum physical fitness benefits, as well as or alternatively to avoid over-stressing their heart.
There are many types of heart rate monitors available to consumers. Most are very bulky and cumbersome. For example, many conventional heart rate monitors include a strap that must be accurately placed around the individual's chest and worn during monitoring. The strap communicates wirelessly with a separate device that is typically worn on the individual's wrist, e.g., interfacing with a watch or bike computer. These types of devices are uncomfortable and require multiple components to be worn or used by the individual.
Other conventional heart rate monitors attempt to utilize photodiodes and LEDs that contact a person's skin (e.g., mounted on a rear side of a watch or device worn on a person's wrist) to measure the light absorption in the blood flowing through the wrist. Because these types of monitors require continuous skin contact, these measurements are often inaccurate as the device bounces around, moves, or encounters sweat or dirt.
Accordingly, there is a need for improved systems and methods that address these and other needs.


A varifocal optical system includes a substantially circular membrane deposited on a substrate, and a ring-shaped PZT thin film deposited on the outer portion of the circular membrane. The membrane may be a MEMS-micromachined membrane, made of thermal oxide, polysilicon, ZrO2 and SiO2. The membrane is initially in a buckled state, and may function as a mirror or a lens. Application of an electric voltage between an inner and outer electrode on the piezoelectric thin film induces a lateral strain on the PZT thin film, thereby altering the curvature of the membrane, and thus its focal length. Focal length tuning speeds as high as 1 MHz have been demonstrated. Tuning ranges of several hundred microns have been attained. The varifocal optical system can be used in many applications that require rapid focal length tuning, such as optical switching, scanning confocal microscopy, and vibration compensation in optical storage disks.

There is a growing demand for optical elements having tunable focal lengths, including adaptive optics systems. For example, adaptive optics technology is used in astronomy in order to overcome significant limitations in the image quality of telescopes, caused by atmospheric turbulence. Also, most optical systems have defects in construction or factors in their environment that prevent them from operating optimally. These defects can be continually measured and automatically corrected by adaptive optics systems, which typically include deformable mirrors whose focal lengths can be changed.
At present, methods and systems that are known in the art for actively changing the focal length of an optical system include at least the following three categories. The first category includes large-scale deformable-optics devices. In these devices, the minor surface is composed of many pixels, each of which has a curvature or angle of inclination that can be altered through an applied voltage to a bulk piezoelectric actuator. The thickness of the deformable portion of each pixel is relatively large, and thus large forces are required and slow speeds are typical. The second category includes electrostatically actuated devices. These devices consist of large membranes suspended over an array of independently controlled electrodes. Voltages applied to these electrodes generate forces on the portion of the membrane in close proximity to the electrodes, causing deflection of the membranes. The shape of the membrane, and thus its curvature and focal length, are determined by the cumulative affects of the electrostatic forces generated by the applied voltages. A third mechanism that provides adaptive focusing uses a lens that translates mechanically along the optical axis, relative to other lenses in the path, thus changing the focal length. These systems have been demonstrated in both macro- and MEMS (microelectromechanical systems) scales. Canon has demonstrated relatively high speeds (approximately 100 Hz bandwidth) with large-aperture lenses, using patented ultrasonic motors that translate one of the optics components within a compound lens along the optical axis. There are also MEMS-based versions which use thin-film piezoelectric cantilevers or similar structures, to move the optical component along the optical axis relative to a static focusing element.
The prior art methods described above suffer from a number of disadvantages. Regarding the first category of devices described above, the capability of current large-scale deformable-optics devices is limited by the large stiffness in typical macro- or mini-mirrors. This stiffness is caused by the appreciable thickness of the actuator and mirror layers. Much larger changes in focal length could potentially be achieved if this stiffness is reduced.
As for electrostatically actuated devices, such devices must avoid electrostatic pull-in onto a planar electrode, in order to maintain a constant curvature for the focusing element. As a result, gaps may be large and forces small. Small electrostatic forces necessitate the use of relatively compliant membranes for the mirrors, which thus limits their mechanical bandwidth. In addition, the non-linear forces generated by the non-uniform gap typically present in such devices will result in non-uniform bending of the plate. The multi-electrode schemes used to compensate for this distortion add additional complexity, particularly when curvature uniformity is required over a large tuning range.
Among mechanically actuated devices, the macroscale systems are typically slow because of the mass of the components. The MEMS versions have a maximum achievable change in focal length that is generally small (typically less than 10 μm), and thus the application is limited to fine tuning.
While piezo-actuated micro-mirrors have been used in conjunction with macro-scale lenses to achieve focusing devices, high-speed micro-lenses with tunable focal lengths have not yet been implemented. A high-speed deformable focusing element could provide new capabilities in numerous applications, such as optical switching, optical storage disks, and scanning confocal microscopy.
For these reasons, there is a need for a system and method that allows for high speed tuning of focal lengths of optical elements (such as mirrors and lenses) over a wide tuning range, and which do not suffer from the advantages described above. In particular, there is a need for high-speed micro-lenses with tunable focal lengths.

High speed piezoelectric optical system with tunable focal length

The Charles Stark Draper Laboratory, Inc.


An apparatus for skinning a squirrel that is easily manufactured, portable, quick and in which the apparatus can be mounted to a variety of surfaces. The apparatus comprises a base plate connected to toggle clamp in which the toggle clamp is engaged to press two metal tubes tightly together. The base plate is bent at an angle and secured to a stationary object. The tail of the squirrel is placed in the apparatus in between the two metal tubes and the toggle clamp is engaged to secure the tail. The skin is pulled from the uncut skin of the tail thereby removing the skin from the body in two pieces of skin.

The present invention relates to animal butchering and, more specifically to squirrel skinning and cleaning. The present invention is an apparatus for holding a squirrel while it is being skinned.
Devices for this purpose in the prior art generally involve impaling the squirrel to hold it for skinning or cleaning, which is potentially hazardous. Examples are U.S. Pat. Nos. 3,137,030 to Varner and 4,094,041 to Steed. Other devices use two or more parts for gripping the animal such as in U.S. Pat. Nos. 3,568,243 to Hines; 3,570,049 to Muckelrath; 3,945,083 to Heightshoe; 4,506,411 to Ivy; and 4,543,688 to Barchus. These devices are relatively large and bulky and are not easily transported with the hunter and multi-part devices are expensive to manufacture. Other devices, such as in U.S. Pat. Nos. 4,625,363 to Watson and 7,163,452 to Taylor, hold the squirrel by the chest, legs, or neck.
It is well known that when a squirrel is manually skinned without the aid of a device, one must first start by pulling the hair away from a spot just above where the tail joins the body and make a cut that leaves a strip of skin uncut at the top edge of the tail. The tail must remain firmly attached to the body and is used as leverage to complete the skinning of the squirrel. Generally, the foot is placed on the tail and held against the ground throughout the skinning process. The present invention holds the squirrel firmly in place by the tail, the grip traditionally used in manually skinning a squirrel, instead of by the chest, legs, or head used in the prior art inventions. The strip of cut skin of the squirrel is pulled in an upward motion, thereby removing the skin from the body. One advantage of the present invention is that it eliminates the need to step on the tail and bend over to complete the skinning process. Further, the present invention is easily manufactured, portable, and can be mounted on a variety of objects.


A light assembly including a socket, a housing, and a mounting member. The socket is connected to the mounting member, which is pivotably secured to the housing and constructed to allow rotation of the socket, and thereby a lighting element engaged with the housing, relative to the housing.

A light fixture typically includes one or more sockets, each of which is supported by the body or housing of the light fixture and electrically connected to a power supply. A lighting element, commonly known as a lamp or light bulb, is engaged with the socket such that when the light fixture is switched ON, power is communicated through the socket to illuminate the lighting element. In many light fixture configurations, the lighting element is positioned within or surrounded by a housing, shade, or reflector, which are configured to direct the light from the lighting element in accordance with the application and/or intended utilization of the light source. For example, a reflector may be positioned about the lighting element in an application in which light emitted from the lighting element is intended to be directed in a common direction. In another example, a housing may be positioned about the lighting element in an application such as a sconce or the like, in which it is desired to obscure the lighting element from certain directions within the room in which the fixture is mounted, and to direct light from the lighting element in an upward direction.
In designing a light fixture, the areas of the fixture adjacent the lighting element must be configured so as to enable replacement of the lighting element. This design criterion creates a certain amount of dead space about the lighting element, since the lighting element is initially engaged with the socket and is then moved inwardly into the socket such that a portion of the area originally occupied by the lighting element is empty when the lighting element is fully engaged with the socket. This necessarily reduces the efficiency of the light fixture, i.e. the number of lumens that can be produced from a fixture of a given size. While the light fixture can be designed to minimize the amount of this dead space, the surfaces of the light fixture adjacent the lighting element simply must be positioned so as not to unduly interfere with the replacement of the lighting element. This problem is compounded in light fixtures that include multiple lighting elements, since the fixture must be designed with a sufficient amount of dead space about each lighting element to enable the lighting elements to be removed and replaced.
It would therefore be desirable to have a light fixture assembly and method of connecting a lighting element to a light fixture that provides enhanced access to the lighting element without interfering with adjacent lighting elements and/or the surfaces of the housing about the lighting element.


Apparatus for storing items within vehicle compartments are provided and include cover panels that are pivotally secured to cargo compartment walls and are movable between a closed position covering a storage area and an open position substantially transverse to the wall allowing access to the storage area. One or more additional panels may be provided that are movable between respective stored positions and operative positions.

The present invention relates generally to vehicles and, more particularly, to cargo management apparatus for use within vehicles.
Motor vehicles are typically provided with a cargo storage compartment of some type. For example, sedan-style automobiles are conventionally equipped with a trunk. Sport/utility and mini-van vehicles, in which there are two or more rows of seating, are conventionally provided with a cargo storage area behind the last row of seating.
Items carried within vehicle cargo storage areas are often free to move about during vehicle operation, which may be undesirable. Cargo netting may be used to restrain items from movement within vehicle cargo storage compartments. While such netting may adequately restrain items from movement, cargo netting may require the use of two hands to hold the cargo netting back while placing items therewithin, which may be cumbersome.
Various devices are known for dividing vehicle storage compartments to prevent movement of items stored therein. For example, U.S. Pat. No. 6,027,155 to Wisniewski et al. describes a storage system for a vehicle cargo compartment that includes a cover that is removably attached to the floor of the cargo compartment and that is configured to rotate between open and closed positions. U.S. Pat. No. 5,669,537 to Saleem et al. describes a storage unit that extends between, and connects to, vehicle panels of a vehicle storage area. U.S. Pat. No. 5,501,384 to Wisniewski describes a storage system for a vehicle that includes a molded bin and a cover pivotally secured to the bin.
Unfortunately, these devices are somewhat complex and bulky and are not adapted to be compactly stored within the cargo storage area of a vehicle. Moreover, in automotive vehicles such as sport/utility vehicles and mini-vans, cargo storage space maybe somewhat limited. Accordingly, a need exists for a cargo storage device that can securely retain items within a cargo storage area during operation of a vehicle and that can be easily stored in an out-of-the-way location when not needed, and without requiring that the storage device be removed from the cargo storage area. In addition, a need exists to maximize the efficiency and utilization of existing cargo storage space without intruding on passenger space.
In view of the above discussion, an apparatus for storing items within vehicle compartments is provided and includes a cover panel that is pivotally secured to a cargo compartment wall and is movable about a substantially vertical axis between a closed position covering a storage area and an open position substantially transverse to the wall allowing access to the storage area. According to embodiments of the present invention, a second panel may be provided that is pivotally secured to the cover panel that is movable between a stored position in adjacent, face-to-face relationship with the cover panel and an operative position disposed substantially transverse to the cover panel and in overlying, face-to-face relationship with the floor. According to embodiments of the present invention, a third panel may be provided that is pivotally secured to the second panel and that is movable between a stored position wherein the third panel is in adjacent, face-to-face relationship with the second panel and an operative position wherein the third panel is substantially parallel with the second panel and in overlying, face-to-face relationship with the floor.
According to embodiments of the present invention, a fourth panel may be provided that is pivotally secured to the third panel and that is movable between a stored position in adjacent, face-to-face relationship with the third panel and an operative position adjacent to and substantially parallel with the cover panel when the cover panel is in its operative position. According to embodiments of the present invention, an extension panel may be provided that is slidably secured to the cover panel and that is movable from a stored position in adjacent, face-to-face relationship with the cover panel and an extended position substantially parallel with the cover panel.
According to embodiments of the present invention, one or more projections may be provided that extend from one or more of the various panels and that are configured to support articles suspended therefrom.

Integrated storage apparatus for vehicle cargo compartments


Disclosed herein are novel contact sensors. The contact sensors disclosed herein include a conductive composite material formed of a polymer and a conductive filler. In one particular aspect, the composite materials can include less than about 10 wt % conductive filler. Thus, the composite material of the contact sensors can have physical characteristics essentially identical to the polymer, while being electrically conductive with the electrical resistance proportional to the load on the sensor. The sensors can provide real time dynamic contact information for joint members under conditions expected during use. In one particular aspect, the sensor can be used to properly balance the knee ligaments in a total knee replacement surgery.

1. Field of the Invention
This invention relates to contact sensors, and more particularly to contact sensors for accurately measuring surface contact data at a junction between two members.
2. Description of the Related Art
Contact sensors have been used to gather information concerning contact or near-contact between two surfaces in medical applications, such as dentistry, podiatry, and in the development of prostheses, as well as in industrial applications, such as determinations of load and uniformity of pressure between mating surfaces and development of bearings and gaskets. In general, these sensors include pressure-sensitive films designed to be placed between mating surfaces. These film sensors, while generally suitable for examining static contact characteristics between two generally flat surfaces, have presented many difficulties in other situations. For example, when examining contact data between more complex surfaces, including, for example, surfaces with complex curvatures, for example, it can be difficult to conform the films to fit the surfaces without degrading the sensor's performance.
More serious problems exist with these materials as well. For example, film-based contact sensor devices and methods introduce a foreign material having some thickness between the mating surfaces, which can change the contact characteristic of the junction and overestimate the contact areas between the two surfaces. Moreover, the ability to examine real time, dynamic contact characteristics is practically non-existent with these types of sensors.
A better understanding of the contact conditions at joints and junctions could lead to reduced wear in materials, better fit between mating surfaces, and longer life expectancy for machined parts. For example, one of the leading causes of failure in total joint replacement prostheses is loosening of the implant induced by wear debris particles worn from the polymeric bearing component. A better understanding of the contact conditions between the joint components would lead to reduced implant wear and longer implant life.
A leading cause of wear and revision in prosthetics such as knee implants, hip implants and shoulder implants is less than optimum implant alignment. In a Total Knee Arthroplasty (TKA) procedure, for example, current instrument design for resection of bone limits the alignment of the femoral and tibial resections to average values for varus/valgus flexion/extension and external/internal rotation. Additionally, surgeons often use visual landmarks or "rules of thumb" for alignment which can be misleading due to anatomical variability. While the success rate of the TKA procedure has improved tremendously over the past several decades, revision is still required in a significant number of these cases. About 22,000 of these replacements must be revised each year and even more revisions are predicted for other joint revision surgeries.
In a conventional TKA procedure, in order to correctly balance the forces on each side of the implant after the bone resection has been made, the surgeon performs a procedure known as soft tissue balancing, or ligament balancing, where the collateral ligaments of the knee are partially incised to even out the forces. Releasing some of the soft tissue points can change the balance of the knee; however, the multiple options can be confusing for many surgeons. In revision TKA, for example, many of the visual landmarks are no longer present, making alignment and restoration of the joint line difficult. This is one of the most difficult parts of the surgery to reproduce, and currently available products are not sufficient to effectively assist surgeons with this procedure.
These difficulties frequently cause surgeons to unknowingly create TKA misalignment, which is the leading cause of early failure, and which results in pain and suffering for the patient and increases the risks associated with a second surgery to replace the failed joint. Studies have shown that the most sensitive alignment is the varus/valgus tilt of the tibial insert, with an alignment error of as small as 3 degrees being sufficient to cause premature failure of the implant. In a study where the forces on each side of the implant were measured intra-operatively, over 70% were misaligned in the varus/valgus direction.
Accordingly, there is a need in the pertinent art for improved implant selection, positioning, and design, as well as a better understanding of the in vivo forces of the components of the implant as they relate to each other, the bone, and the surrounding soft tissue structures. There is also a need in the pertinent art for improvement in the mechanical and wear characteristics of knee prostheses such that the prostheses may be expected to last a lifetime. There is a further need in the pertinent art for tools with which physicians can perform diagnostics, during surgery, on prostheses implanted within a patient. There is still a further need in the pertinent art for devices, methods and protocols for joint and bone alignment and tracking for preliminary tests during joint replacement surgery.

Contact sensors and methods for making same


The present invention relates to a semiconductor structure and a method for manufacturing the same. A semiconductor structure comprises: a semiconductor substrate; a first insulating material layer, a first conductive material layer, a second insulating material layer, a second conductive material layer and an insulating buried layer formed in sequence on the semiconductor substrate; a semiconductor layer bonded on the insulating buried layer; transistors formed on the semiconductor layer, the channel regions of the transistors each being formed in the semiconductor layer and each having a back-gate formed from the second conductive material layer; a dielectric layer covering the semiconductor layer and the transistors; isolation structures for at least electrically isolating each transistor from its adjacent transistors, the top of the isolation structures being flush with or slightly higher than the upper surface of the semiconductor layer, and the bottom of the isolation structures being in the second insulating material layer; and a conductive contact running through the dielectric layer and extending down into the first conductive material layer.

Generally, an integrated circuit (IC) includes a combination of NMOS (n type Metal-Oxide-Semiconductor) transistors and PMOS (p type Metal-Oxide-Semiconductor) transistors formed on a substrate. In order to increase the efficiency of the very large scale integrated circuits and to reduce the manufacturing costs, a continuous trend is to reduce the feature size of the device, especially the length of the gate. However, the reduction in the length of the gate will result in short-channel effects, thus degrading the performances of the semiconductor device and the whole integrated circuit.
The SOI (Silicon-On-Insulator) technique is to introduce a buried oxide layer (BOX) between the top layer silicon and the substrate. The existence of the buried oxide layer enables a complete dielectric isolation between elements in the integrated circuit, so the SOI-CMOS integrated circuit substantially avoids the parasitic latch-up effect in the bulk silicon CMOS circuit. Meanwhile, in the complete depletion type SOI device, short-channel effects are small, a shallow junction can be naturally formed, and the leakage is small. Therefore, the complete depletion SOI-MOSFET having an ultrathin SOI and dual gates have attracted wide attention. In order to adjust the threshold voltage and to suppress the short-channel effects, a ground plane, which is sometimes used for connecting to the semiconductor layer, is formed under the ultrathin oxide buried layer in the SOI-MOSFET device, and the ground plane is made to have a low resistance so as to form a back-gate structure of the transistor. However, according to conventional methods, in order to connect the ground planes of the NMOSFET and PMOSFET to the respective voltage sources, extra contacts and interconnections are needed, resulting in an increase in the area occupied by the device.
Hence, there is a need for an improved method to connect the ground planes of the NMOSFET and PMOSFET to the respective voltage sources to reduce the area occupied by the device.

Semiconductor structure and method for manufacturing the same

Institute of Microelectronics, Chinese Academy of Sciences


Feed dispenser for feeding birds, comprising a dispenser tray (1) having a center section (2) which is raised relative to the bottom surface (3). The raised center section interacts with a downpipe (7) in such a way that a supplied volume of feed (8) is distributed over the bottom surface of the dispenser tray. The center section of the dispenser tray is joined to the bottom surface which blends into a rising outwardly directed side wall (4). The side wall ends in an outer edge. The dispenser tray comprises at least two steep wall sections in the side wall at different height levels relative to the bottom surface. The steep wall sections extend in a direction parallel to the outer edge. In the vertical direction, the side wall has a top (4c) and a bottom half (4d). The bottom half comprises at least two steep wall sections.

Such feed dispensers are for example known from EP-0421553, BE-08701293, EP-0626133 or EP-0483963. EP-0421553 shows a feed dispenser which is intended to provide feed for birds roaming freely inside a space in breeding farms. A complete feed distribution system generally comprises a storage device for a large volume of feed and a pipe conveyor system in which typically large numbers of feed dispensers are arranged at regular intervals along feed conveyor pipes. In this way, feed can be transferred from the storage device to various feed points. The feed conveyor pipes are generally arranged at a fixed distance with respect to one another within the space.
The feed dispenser illustrated has a dish-shaped pan on which the feed is offered to the birds. The dish-shaped pan has a raised outer edge. The outer edge of the dish-shaped pan is attached to a snap ring of a grating with the aid of a click-fit connection. The grating comprises a number of curved bars. The space between the bars forms a feeding position and offers the birds access to the feed in the dish-shaped pan. A conical centre section of the dish-shaped pan interacts with a downpipe which is situated above the centre section. There is an opening between the downpipe and the conical centre section of the dish-shaped pan through which the feed is conveyed from the feed conveyor pipe via the downpipe into the dish-shaped pan. In this manner, the feed is distributed evenly over the dish-shaped pan. In many cases, the feed is in powder form or granule form and contains a mixture of ingredients.
A drawback of the known feed dispenser is that the birds are able to sift various ingredients from the feed. For good growth and resistance against disease, it is important that the birds are fed a balanced mixture of ingredients. However, when various ingredients are offered to the birds at the same time in a mixture, the birds will have a preference for certain ingredients. The ingredients which are valued less are taken from the feed mixture and moved. This sifting out is observed particularly with laying-hens.
As a result of this sifting out, the birds will eat less diverse feed which is disadvantageous for the growth of the birds. This will lead to differences with regard to growth within the group of birds as not every animal receives feed of identical composition. Some animals will grow more quickly than others as these animals have a preference for growth-enhancing ingredients contained in the feed mixture. As a result of sifting the feed, the growth of other animals will lag behind. Consequently, the growth of the animals is not uniform throughout the entire group of birds.
In addition, sifting through the feed leads to more differences within the group of birds, such as differences in the state of health and the quality of the eggs. It will be clear that sifting is a phenomenon which is undesirable for a breeder.
During sifting, the ingredients from the feed mixture are removed from the opening between the downpipe and the conical centre section of the dish-shaped pan, so that fresh feed falls onto the dish-shaped pan again. The ingredients which are less popular with the birds accumulate as a result of the feed which is offered in the dish-shaped pan being moved to the outermost peripheral edge near the peripheral edge of the dish-shaped pan.
The displaced feed then presents a second disadvantage. The feed which is close to the peripheral edge of the dish-shaped pan is spilled over the peripheral edge more quickly. Spilled feed usually falls through a grating and is thus no longer eaten, resulting in economic damage to the breeding farm. In addition, the spilled feed forms a possible source of moulds and bacteria. Spilled feed is no longer fresh and may, if this is still eaten by the birds, negatively affect the well-being of the animal.


An apparatus and method are provided for sending a first data packet comprising a Quality of Service (QoS) data flow identifier indicating a QoS data flow which the first data packet belongs to, and a data flow sequence number indicating a position of the first data packet in a sequence of the QoS data flow. A second data packet that is a duplicative of the first data packet is sent in a second QoS data flow, and has a sequence number that is incremented from that of the first data packet. The duplicative packets are transmitted via a first tunnel for transmitting the first QoS flow and a second tunnel for transmitting the second QoS flow. Reliability of such data transmission may therefore be improved. The duplication and sequencing may be implemented in the downlink and/or uplink direction.

Reliability of successful data transmission can be improved by sending a duplicate of an original data packet as well as the original data packet to a target device in a network. Such data transmission techniques include redundant data transmission. Nevertheless there may still be problems if an original data packet or its duplicate is not sent to or received properly at the target device.

Sending a duplicate of an original data packet to a target device in a network


The air tool hook is comprised of a pair of connection fittings for compressed fluids with a first connection on one end of the fitting for connecting a compressed air line and a second connection on the other end of the fitting for attaching a pneumatic tool to the compressed air line, a manifold, wherein one end of the manifold is attached to a side of the fitting and a hole is bored through the other end of the manifold, a hook with one end shaped for hanging the hook and the other end, a straight shaft, sized and shaped to be placed through the hole of the manifold, grooves cut into the shaft, retaining clips attaching the shaft to the manifold, whereby the clips are placed into the grooves of the shaft on either side of the hole, the first and second connections are rotatable, and the hook and shaft are rotatable with respect to the manifold, whereby the air line, the pneumatic tool and the hook are able to rotate independently.

This invention relates generally to a pneumatic tool hook that is comprised of an assembly of components that are designed to be placed in line with a compressed air source at one end and a pneumatic tool at the other end with a hook assembly attached to the air line and tool so a tool user can attach the tool and the air line to a hanging appendage for ease of use, safety and ease of access to the tool for the user. The air tool hook or tool hook is situated near the tool and is connected to the compressed air source with various types of connections used with compressed air tools and compressed air lines and known to those skilled in the art. Typically a quick disconnect component with a shaft connects the air line to the tool with compressed air passing through the interior of the shaft and means for connecting the tool hook in line with the compressed air and tool. The shaft body has an appendage herein called the manifold that is perpendicularly connected to the shaft or compressed air line and the manifold is the link between the air line and a hook or similar type device used to hang the line and tool. The hook is used to attach the tool to the top of a ladder or structural frame or other available hanger, such as a hook, clamp, hole or other available object. The hook can be used to support the air line, pneumatic tool or both when a user needs to put down the tool and is not in a place to lay the tool on the ground or other surface. The independent swiveling action of the hook on the manifold with respect to the air line and pneumatic tool make this innovation unique and improves the safety and efficiency for users or pneumatic tools. The universal nature of the air tool hook allows the user to quickly and efficiently substitute various tools while using the same tool hook.
The use of a hook for pneumatic tools is known in the prior art. U.S. Pat. No. 7,231,990 "Limit Structure for a Hook of a Pneumatic Tool" to Lai discloses a hanger and a loop assembly for placement on a pneumatic tool; U.S. Pat. No. 6,010,103, "Hook for Air Guns and Air Nailers", to Ashwort discloses an "L" type hook with a hole on one end of the bent hook for attaching to the compressed air line and pneumatic tool; and U.S. Pat. No. 7,306,052 "Multi-Position Utility Hook Assembly for Tool", to Vahabi-Nejad et al., which discloses a hook assembly that is made part of a power tool including pneumatic tools.
The various hooking devices described and claimed in the prior art have several limitations that the present invention is able to overcome. One limitation found in the prior art is the inability to quickly switch the various pneumatic tools between the various jobs at a construction site without removing the hooking device either on the tool or on the pneumatic line. The present invention provides an inline hooking assembly that allows for quick switching of pneumatic tools from the compressed air while leaving in place the tool hook.
Another limitation of the prior art is the lack of versatility for the various pneumatic tools used at a construction site. The present invention is able to be used with a wide variety of pneumatic tools and provides an easy means for switching between the various tools. The present invention allows the user to attach a pneumatic tool onto the compressed air line and adjust the center of mass of the tool as the tool is hung on any available object or surface structurally capable of supporting the air line and tool, such as a ladder rung. For example, some tools have a center of mass that is not centrally located within the dimensions of the tool, like a tool that has an appendage or weighted on one side or end of the tool. The present invention allows the worker to adjust the location of the hook with respect to the compressed air line such that the center of mass for any particular tool permits the user to safely hang the tool and minimized any swing or sway once it is hung up.
Another limitation of the prior art is the aspect in which the tools are hung. Some of the hooking devices limit how the tool can be hung, such as bottom down, top down, handle down, handle up or other various positions that make hanging the tool unsafe or awkward for retrieval. When a worker is reaching or grabbing for a tool, the worker may be limited in their movement or restricted in their ability to move. The worker would like to be able to hang the tool and then be able to reach for the tool in the safest and easiest manner. The prior art provides for placements of hooking devices without the ability to adjust or change the way in which a worker could hang the tool when not in use. The present invention allows the worker to set the hook either toward or away from the tool and adjustments of the hook allow for the tools center of mass to be balanced at the best or better position for the worker's safety and ease of use. For example, a particular tool may be hung such that the handle of the tool is located on the underside of the tool and therefore the hook is best place away from the handle if the worker is grabbing or reaching for the tool from above or below the workers arms. If the tool is to be hung above the worker the hook can be placed toward the tool and the handle is easier to grab. The placement of the hook either toward or away from the tool can be changed depending on how the worker is grabbing or reaching for the tool.
Another limitation of the prior art is the limited means for attaching a hooking device for the various types of pneumatic tools. There is a variety of connecting devices or fittings for pneumatic tools and each type of fitting requires a different type of connection. The present invention allows for a variety of connection fittings to be used with the air hook and allows for switching the connection depending upon the type of fitting on the particular tool or air line fitting.