A reflective film includes a polymeric layer and a reflective component. The polymeric layer includes a polyimide polymer, where the polyimide polymer has a backbone with at least one non-terminal phenyl group. A linkage is connected to the non-terminal phenyl group, where the linkage can be an amide linkage or an ester linkage. An oligomeric silsesquioxane compound is connected to the linkage through an organic substituent, where the oligomeric silsesquioxane is not incorporated into the polymer backbone.

1. Field of the Invention
The invention relates to a reflective film for thermal control, and more particularly to thermal control in high altitude environments.
2. Description of the Related Art
Polyimides are an important class of polymeric materials and are known for their superior performance characteristics. These characteristics include high glass transition temperatures, good mechanical strength, high Young's modulus, good UV durability, and excellent thermal stability. Most polyimides are comprised of relatively rigid molecular structures such as aromatic/cyclic moieties.
As a result of their favorable characteristics, polyimide compositions have become widely used in many industries, including the aerospace industry, the electronics industry and the telecommunications industry. In the electronics industry, polyimide compositions are used in applications such as forming protective and stress buffer coatings for semiconductors, dielectric layers for multilayer integrated circuits and multi-chip modules, high temperature solder masks, bonding layers for multilayer circuits, final passivating coatings on electronic devices, and the like. In addition, polyimide compositions may form dielectric films in electrical and electronic devices such as motors, capacitors, semiconductors, printed circuit boards and other structures. Polyimide compositions may also serve as an interlayer dielectric in both semiconductors and thin film multichip modules. The low dielectric constant, low stress, high modulus, and inherent ductility of polyimide compositions make them well suited for these multiple layer applications. Other uses for polyimide compositions include alignment and/or dielectric layers for displays, and as a structural layer in micromachining applications.
In the aerospace industry, polyimide compositions have been used for optical applications as reflective membranes. In application, a polyimide composition is secured by a metal (often aluminum, copper, or stainless steel) or composite (often graphite/epoxy or fiberglass) mounting fixture that secures the polyimide compositions. Such optical applications may be used in space, where the polyimide compositions and the mounting fixture are subject to repeated and drastic heating and cooling cycles in orbit as the structure is exposed to alternating periods of sunlight and shade. Satellites can remain in orbit for extended periods, so the materials used should survive as long as the satellite remains functional.
One important factor of a material in space is its service temperature. Generally, there are three types of heat transfer: conductive heat transfer where heat passes to or from a first object to a second object touching the first object; convective heat transfer where heat passes from a first object to a gas, such as the atmosphere; and radiant heat transfer, where heat passes to or from an object through electromagnetic radiation, such as infrared (IR) light. Radiant heat transfer controls the temperature of an object in space. Radiant heat transfer can also be significant for objects in high altitude environments, because the atmosphere for convective heat transfer is thin and no objects are present for conductive heat transfer. "High altitude environment" is defined to include altitudes above 20,000 feet, the stratospheric near-space environment, and space.
Polyimide polymers are subject to rapid degradation in a highly oxidizing environment, such as an oxygen plasma or atomic oxygen [AO], as are most hydrocarbon- and halocarbon-based polymers. AO is present in low earth orbit [LEO], so many spacecraft experience this highly oxidizing environment. The interactions between the oxidizing environment and the polymer material can erode and reduce the thickness of the polymer material. To protect from erosion, protective coatings including metals, metal oxides, ceramics, glasses, and other inorganic materials can be applied as surface treatments to polyimides subjected to the oxidizing environment.
While these coatings are effective at minimizing the oxidative degradation of the underlying material, they often experience cracking from thermal and mechanical stresses, mechanical abrasion, and debris impact. After cracking, the protective surface is compromised and the underlying polymeric material can be degraded from additional exposure to the oxidizing environment. Therefore, the availability of polymers which are able to resist AO degradation is very desirable.
Oligomeric silsesquioxanes [OS] can be incorporated into a polyimide matrix to improve the durability of polyimides in these environments. Polyimides with incorporated OS demonstrate excellent resistance to AO degradation prevalent in LEO environments. Polyimides with incorporated OS provide additional benefits as well. Polyhedral OS are referred to by the trademark POSS™, and are a common form of OS.
Rockets, aircraft, other lift engines, and lighter than air gases are often used to carry a cargo into space or other high altitude environments. Much of the total mass of a space rocket is the fuel used to propel the rocket into space, and the mass of any cargo carried into high altitude environments is limited. Cargo carried into high altitude environments is typically limited to a certain size and weight to fit within the confines and capabilities of the vehicle carrying the cargo. The cost per unit weight of delivering a vehicle, cargo, and payload into high altitude service is high, so many efforts are made to reduce the total weight. Reductions in the total volume occupied by the cargo are also beneficial. The various components of a vehicle, cargo, and/or payload should be able to withstand the harsh high altitude environment for the expected life. Reducing the cargo weight can save costs, or allow for additional components to be included with the vehicle. Efforts to find new materials or combinations of materials which can withstand the high altitude environment and which can reduce the weight and volume of the vehicle, cargo, and/or payload continue. Materials which can withstand high altitude environments may also be beneficial in other environments, such as certain industrial applications.


A multi-layered signage-lettering material containing a release or casting sheet layer with a pigmented display layer deposited on one side of the release sheet is described. The pigmented display layer is a coalesced film of at least one water-borne polymer of for example water-borne polyurethanes, water-borne acrylics, and mixtures thereof. Optionally, the coalesced film may be applied in multiple coats. The multi-layered material also includes an adhesive layer covering the surface of the pigmented display layer opposite the release sheet, and optionally, a removable protective layer covering the surface of the adhesive layer opposite the pigmented display layer. A method of fabricating the multi-layered signage-lettering material described above also is described. The method includes first depositing the pigmented display layer on the release or casting sheet. This is accomplished by first dispersing pigment in at least one water-borne polymer for example, water-borne polyurethanes, water-borne acrylics, and mixtures thereof. Additionally, functional additives may be added to improve flow, wetting, and foaming characteristics of the resultant mixture. The mixture is then made machine spreadable by adding water and/or a viscosity modifying agent. The mixture is then machine spread on the release sheet and the water is evaporated allowing for coalescence and film formation. A layer of adhesive is then applied to the surface of the pigmented display layer opposite the release sheet and optionally, on top of the adhesive, opposite the pigmented display layer, a removable protective layer is applied.

Lettering sets, including a pigmented plastic display layer backed by an adhesive layer, to be computer cut and retained in position on a transparent stripable release sheet, are familiarly used for applying athletes' names, numbers and team logos to their athletic garments. Three-layer lettering sets, using a pigmented polyvinyl chloride plastic lettering display sheet backed by a sheet of adhesive and having a transparent front release sheet, which aids in positioning on garments or other substrates, are described in U.S. Pat. Nos. 5,112,423 and 5,441,785 to Liebe. Outlines of lettering elements in mirror-image are cut starting through the adhesive sheet and through the lettering sheet, to and sometimes into but not through, the release sheet.
In another form, lettering sets are made with a pigmented polyvinyl chloride (PVC) display layer with an adhesive backing sheet but without the paper forward sheet on which the PVC was originally cast. The cutting proceeds in direct, not mirror-image, order, first through the pigmented layer and then through the adhesive layer. After the portion between the lettering outlines have been removed, a handling sheet, usually a transparent sheet whose surface is somewhat adherent, is pressed against the forward side of the lettering elements to lift them and position them in place on a garment or other substrate.
Polyvinyl chloride materials are inexpensive but require temperatures of about 320.degree. .F to form a film. PVC materials may contain solvents to aid in spreading and casting the display layer film. U.S. Pat. No. 5,312,645 suggests that a solvent-based polyurethane may be substituted for PVC to gain improved tensile strength, abrasion resistance and capacity for elongation. A film of a solvent-based polyurethane may be formed at a temperature necessary for solvent evaporation, which may be as low as ambient temperature.
A problem associated with solvent-based materials being used as pigmented display layers is that the choice of the material of the release or casting sheet is limited to materials that are resistant to the solvents used in the pigmented display layer and resistant to the temperature of the solvent evaporation process. Typically, paper and polyester release or casting sheets are used in the manufacture of lettering sets because of their resistance to solvent and heat distortion.
It would desirable to be able to use a release sheet that is more flexible than the typical paper or polyester release sheets. It also would be desirable to be provide a release sheet that is thin to achieve greater flexibility.

Multi-layered plastic lettering web and method of producing


A software activation system includes a sewing machine and at least one server connected via a network. The sewing machine acquires an authentication code corresponding to an activation target software that is at least one of a program and data not activated on the sewing machine, and transmits, to an authentication server included in the at least one server, an authentication request including the acquired authentication code. The server acquires an authentication key on the basis of the authentication request, when the authentication request is received by the first receiver; and transmits the acquired authentication key to the sewing machine. The sewing machine also receives the authentication key from the authentication server, determines whether the received authentication key satisfies a predetermined authentication condition, and activates the activation target software on the sewing machine when it is determined that the authentication key satisfies the predetermined condition.

The present disclosure relates to a software activation system including a sewing machine and a server connected via a network, a sewing machine, and a server.
In related art, a system is known in which a sewing machine and a server are connected via a network. In this system, for example, an authorized user can read an update program from a CD-ROM via a PC, and can execute the update program on a sewing machine connected to the PC. In this system, when the user inputs a sewing machine number and a unique CD key of the CD-ROM from a keyboard of the PC, the input sewing machine number and CD key are transmitted to a Web server. The Web server generates an authentication key through computation on the basis of the sewing machine number and the CD key, and transmits the authentication key to the PC. The user inputs the authentication key displayed on the PC to a touch panel of the sewing machine. The sewing machine computes the sewing machine number using reverse computation of the input authentication key, and when the computed sewing machine number matches the sewing machine number of the sewing machine itself, the sewing machine activates the update program.

Software activation system, sewing machine, and server


A system and method is described for increasing effective integration time of an optical sensor including holding a first signal within each pixel cell, proportional to light integrated by the pixel cell over the previous frame period, generating a second signal within each pixel cell proportional to light integrated by the pixel cell over the current frame period, and summing the first signal and the second signal from each pixel, thereby producing an output signal representing the light integrated by each pixel over two frame periods. If saturation of pixel cells is possible, a further method of extending dynamic range is described including generating and storing a first signal in each pixel cell indicative of light integrated by the pixel cell over a long period, generating a second signal in each pixel cell indicative of light integrated by the pixel cell over a short period, and determining an output for each pixel as the first signal whenever the first signal is less than a threshold value, otherwise determining the output as the second signal. Also included are double correlated sampling for noise reduction, interlacing for increased integration time, and individual pixel reset for additional gains in dynamic range.

Optical sensors find a variety of uses, including satellite attitude sensors, video cameras and security systems. Many of these applications, such as a vehicle viewing system, are required to operate over an extensive range of conditions. For example, a wide intra-scene brightness range allows for viewing dimly lit night scenes even in the presence of glare from headlamps. A wide inter-scene brightness range allows for viewing scenes illuminated by bright sunlight as well as moonlight. Still further, frame rates must allow for displayed scenes to appear real-time.
Charge-coupled devices (CCDs) have often been the technology of choice. A CCD optical sensor operates as an analog shift register, passing charge developed in proportion to light incident on a pixel across adjacent pixels until the charge reaches an end pixel where it is processed. However cost, read-out rate limitations, requirements for high and multiple voltage levels, and support electronics integration incompatibilities have prohibited large-scale adaptation of CCDs into certain applications such as vehicle viewing systems.
Unlike CCDs, active pixel sensors (APSs) utilize at least one active element within each pixel to accomplish amplification, pixel selection, charge storage or a similar benefit. As such, APS devices have many of the benefits of CCDs including high sensitivity, high signal fidelity and large array formats. Because APS cells are accessed in a row-wise manner, the problems arising from transferring charge across pixel cells, as is done in CCD sensors, are alleviated. Additional comparisons between APS cells and other devices are presented in, for example, "Active Pixel Sensors: Are CCD's Dinosaurs?" in Proceedings of SPIE: Charge-Coupled Devices and Solid State Optical Sensors III, Vol. 30, pp. 2-14 (1993) by E. R. Fossum, which is hereby incorporated by reference.
One form of APS utilizes a photodiode p-n junction and a source-follower buffer in each pixel. However, photodiode devices typically suffer from high kTC, 1/f and fixed pattern noise, thereby limiting dynamic range.
An alternative APS design uses a metal-on-silicon (MOS) photogate to accumulate charge proportional to light incident during an integration period. The charge can be shifted to a sensing region for readout. The sensing region can also be reset, allowing a reference output indicative of noise levels. The reference can be subtracted from the integrated light value to implement correlated double sampling.
A photogate device presents several benefits. A first benefit is that photogates have a very low noise level compared to other devices such as photodiodes. This results in the need for less integration time to achieve a desired light sensitivity. A second benefit is that the photogate APS is compatible with standard CMOS manufacturing methods. This allows an APS array together with control and processing circuitry to be built on the same integrated circuit chip.
In order to accommodate wide intra-scene and inter-scene brightness levels, an increased dynamic range is required. This can be accomplished by increasing the integration time used by each pixel cell in the optical sensor. Traditionally, integration time has meant a corresponding increase in frame time. Since frame time determines the rate at which the output image is updated, increasing frame time may result in output images that no longer appear real-time.


To prevent the high-frequency characteristic from deteriorating due to a narrow track. A thin-film magnetic head of the present invention is produced by forming a lower shielding layer, a read gap layer holding an MR magnetosensitive element facing to an ABS plane, a shared pole layer serving as an upper shielding layer and a lower pole layer, and a write gap layer laminated in order on an insulating substrate, by forming a first flattening layer, a coil pattern layer, and a second flattening layer laminated in order on the write gap layer excluding the vicinity of the ABS plane, and by forming an upper pole layer on the write gap layer and second flattening layer nearby the ABS plane. Because magnetic easy axis of the upper pole layer along the ABS plane is oriented in the thickness direction of the upper pole layer, the high-frequency characteristic in the magnetization rotation mode is obtained.

1. Field of the Invention
The present invention relates to an inductive-type thin-film magnetic head and a magnetic storage apparatus using the magnetic head.
2. Description of the Prior Art
The recording density of a hard disk drive has been remarkably improved. The recording density from 1990 downward tends to rise at an annual rate of approx. 60%. To improve the recording density of a hard disk drive, it is necessary to improve the recording track density by decreasing the track width of a magnetic head. Moreover, to improve the recording density, it is also important to improve the recording bit density. To improve the recording bit density, it is necessary to increase the coercive force (Hc) of a magnetic storage medium. Moreover, to write data in a high-Hc magnetic storage medium, an inductive recording head having a high recording capacity is necessary. Furthermore, to efficiently detect a signal output from a micro-scaled recording bit, an MR reproducing head is necessary. Therefore, an MR-inductive composite-type thin-film magnetic head constituted by combining an MR reproducing head with an inductive recording head is prospective for high-density recording.
FIG. 11 is a sectional view showing a conventional thin-film magnetic head. The thin-film magnetic head will be described below by referring to FIG. 11.
The conventional thin-film magnetic head 70 is produced by forming a lower shielding layer 74, a read gap layer 80 holding an MR magnetosensitive element 78 facing to an ABS plane 76, a shared pole layer 82 serving as an upper shielding layer and a lower pole layer, and a write gap layer 84 laminated in order on an insulating substrate 72; by forming a first flattening layer 86, a coil pattern layer 88, and a second flattening layer 90 laminated in order on the write gap layer 84 excluding the vicinity of the ABS plane 76; and by forming an upper pole layer 92 on the write gap layer 84, first flattening layer 86, and second flattening layer 90 nearby the ABS plane 76.
The shared pole layer 82 serves as an upper shielding layer for improving the reproducing resolution of an MR reproducing head and a lower pole layer of an inductive recording head. The MR magnetosensitive element 78 detects a signal magnetic field outputted from a not-illustrated magnetic storage medium facing to the ABS plane 76. The thickness of the write gap layer 84 serves as the gap of the inductive recording head. The first flattening layer 86 serves as the insulating base of the coil pattern layer 88 and the second flattening layer 90 smoothens the irregularity in height of the coil pattern layer 88. A portion on the write gap layer 84 nearby the ABS plane 76 where there is no first flattening layer 86 determines the gap depth D of an inductive recording head. A recording track width is determined by the front end portion width W (not illustrated) of the upper pole layer 92. The front end portion width W represents the width of the upper pole layer 92 along the ABS plane 76 (front end) in the direction vertical to the drawing plane, which is shown in FIG. 2 or the like.
To improve the recording capacity for high-density recording, it is preferable to set the gap depth D to a small value of approx. 1 [micron meter] or less. Moreover, to correspond to high-density recording, it is preferable to realize an upper pole layer 92 having a minimum front end portion width W. Furthermore, because a recording/reproducing data transfer rate is raised as a recording density (particularly, linear recording density) rises, a high speed recording capacity is required for a magnetic head for high-density recording.
Moreover, Japanese Patent Application Laid-Open No. 4-285711 discloses an invention for accurately forming a very-small-width magnetic-pole front end portion of a magnetic recording/reproducing thin-film magnetic head. Specifically, the front end portion of a lower magnetic pole and that of an upper magnetic pole are simultaneously formed on a lower magnetic-pole layer, gap layer, and upper magnetic-pole layer formed on a substrate through simultaneous ion etching by using a mask corresponding to the shape of a magnetic-pole front end portion. Then, a thin-film coil and an insulating film are formed to form the rear of an upper magnetic pole.
Furthermore, Japanese Patent Application Laid-Open No. 7-192222 discloses a thin-film magnetic head capable of effectuating a high-density recording/reproducing characteristic and an overwriting characteristic for data write. In this case, among gaps formed on a pole portion, a pole front end portion is formed into a narrow gap and the innermost side of the pole portion is formed into a wide gap g2.
Furthermore, Japanese Patent Application Laid-Open No. 9-237407 discloses a thin-film magnetic head capable of realizing higher density recording by reducing the number of magnetic fields generated at the lateral side of a magnetic pole and controlling the write spread and moreover, controlling the eddy-current loss when raising a recording frequency. In this case, the cross section of an upper magnetic pole is formed into a trapezoid and the major side is set so as to face a lower magnetic pole (upper shielding layer). Moreover, an upper magnetic pole is formed into a two-layer structure, the first layer of a lower magnetic pole is formed of a magnetic material having a large residual flux density, magnetic permeability, and resistivity (e.g. FeN, FeNZr, or FeNNb) and the second layer of it is formed of permalloy.
The first problem is that a pattern accuracy enough to decrease a gap depth D and a front end portion width W is not obtained. The first problem will be described below in detail using FIG. 1.
To form a necessary gap depth D, the first flattening layer 86, which defines the gap depth D, must be considerably nearing the ABS plane 76. Therefore, the conventional thin-film magnetic head 70 had the following problem in order to form a resist frame pattern (not illustrated) for forming the upper pole layer 92 through the frame plating method.
The first flattening layer 86, coil pattern layer 88, and second flattening layer 90 are laminated in order and then, a resist frame pattern is formed. In this case, a large height difference is formed between the write gap layer 84 and the second flattening layer 90 at the front end portion. Therefore, the film thickness of the resist frame pattern at the front end portion becomes 10 (micron meter) or more and thereby, the accuracy for forming a thin pattern through photo lithography process is deteriorated. Moreover, front end sides of the first flattening layer 86 and second flattening layer 90 are respectively formed like a curved surface. Therefore, light for exposure in photo lithography process reflects on the curved surface and thereby, the vicinity of the ABS plane 76 of the resist frame pattern is easily overexposed.
As a result, the resist frame pattern for forming the front end portion of the upper pole layer 92 has a large film thickness and it is partially overexposed. Thereby, a narrow track pattern cannot be obtained. Thus, to obtain a preferable gap depth D, it is difficult to obtain a preferable front end portion width W.
The second problem is that the high-frequency characteristic is deteriorated to decrease the front end portion width W, that is, the track width. The second problem is described below in detail.
FIGS. 12(a) and 12(b) are illustrations showing magnetic domains of magnetic thin films. FIG. 13 is a graph showing the frequency dependency of the magnetic permeability of a magnetic thin film. The second problem will be described below by referring to FIG. 11 to FIG. 13.
The frequency response of the recording/reproducing characteristic of the thin-film magnetic head 70 greatly depends on the shape of the recording-pole magnetic domain of the head 70. As shown in FIGS. 12(a) and 12(b), the magnetic permeability of a sheet-like magnetic thin film 100 greatly depends on the direction of magnetic easy axis 102 of the magnetic thin film 100 and the direction of an externally applied signal magnetic field 110. The magnetic domain structure in the magnetic thin film 100 has closure domain structure in which a magnetic domain 106a having a magnetizing direction 104a parallel with magnetic easy axis 102 occupies the most part and a triangular magnetic domain 106b having a magnetizing direction 104b vertical to magnetic easy axis 102 is adjacent to the magnetic domain 106a so that a magnetic field does not exit to the end of a magnetic thin-film pattern. The boundary between the magnetic domains 106a and 106b is a magnetic domain wall 108.
As shown in FIG. 12(a), the case in which magnetic easy axis 102 is perpendicular to the signal magnetic field 110 is referred to as xe2x80x9cmagnetization rotation mode.xe2x80x9d As shown in FIG. 12(b), the case in which magnetic easy axis 102 is parallel with the signal magnetic field 110 is referred to as xe2x80x9cmagnetic-domain-wall moving mode.xe2x80x9d As shown in FIG. 13, the magnetization rotation mode is superior to the magnetic domain wall mode in high-frequency characteristic by approx. order of two. This is because the rotational speed of magnetization is higher than the moving speed of a magnetic domain wall by order of two to three.
The above mentioned, a conventional-thin-film magnetic head is shown in FIG. 6.29 (p. 6.34) and FIG. 6.30 (p. 6.35) of xe2x80x9cMagnetic Recording Technology, Second Edition (issued in 1996)xe2x80x9d edited by C. D. Mee and E. D. Daniel, issued by MacGraw Hill, Inc., wherein a magnetic domain structure has a magnetic anisotropy vertical to a signal magnetic field and the magnetizing direction vertical to the signal magnetic field at the front end portion of a recording pole.
FIGS. 14(a) and 14(b) are illustrations showing the magnetic domain structure of a conventional thin-film magnetic head, in which FIG. 14(a) is a plan view and FIG. 14(b) is a front view. FIGS. 15(a) and 15(b) are illustrations showing the magnetic domain structure of a conventional thin-film magnetic head for narrow tracks, in which FIG. 15(a) is a plan view and FIG. 15(b) is a front view. The magnetic domain structures are described below by referring to FIGS. 11, 14, and 15.
As shown in FIGS. 14(a) and 14(b), in a thin-film magnetic head 70, magnetic domain structures of a shared pole layer 82 and an upper pole layer 92 are formed so that magnetic easy axis 102 is perpendicular to a signal magnetic field 110. Thereby, a magnetization rotation mode is realized.
As shown in FIGS. 15(a) and 15(b), however, when the recording track width decreases, a magnetizing direction is set along the pattern end at the front end portion of the upper pole layer 92 even if magnetic easy axis 102 is vertical to the signal magnetic field 110 in order to prevent the number of demagnetization fields at the pattern end from increasing. With the magnetic domain structure having the front end portion of the upper pole layer 92 described above, the response of magnetization for the signal magnetic field 110 becomes the magnetic-domain-wall moving mode and thereby, the high-frequency characteristic is deteriorated.
Therefore, it is an object of the present invention to provide a thin-film magnetic head capable of accurately decreasing a gap depth D and a front end portion width W without deteriorating any high-frequency characteristic due to decrease of a track width and to provide a magnetic storage apparatus using the thin-film magnetic head.
A thin-film magnetic head of the present invention is produced by forming a lower pole layer, a write gap layer, and an upper pole layer laminated in order along an ABS plane. Moreover, the upper pole layer is configured from a front end portion facing to the ABS plane and a yoke portion connected to the front end portion through a junction, magnetic easy axis of the front end portion on the ABS plane is oriented in the film thickness direction of the front end portion. Magnetic easy axis of the front end portion of the upper pole layer is vertical to a signal magnetic field because the axis is oriented in the film thickness direction of the front end portion. Therefore, the recording frequency response is dominated by the magnetization rotation mode.
The thin-film magnetic head in claim 2 is produced by forming a lower pole layer, a first flattening layer, a coil pattern layer, and a second flattening layer laminated in order on the write gap layer excluding the vicinity of an ABS plane, and by forming an upper pole layer on the write gap layer nearby the ABS plane. Moreover, the upper pole layer is configured from a front end portion facing to the ABS plane and a yoke portion connected to the front end portion through a junction, magnetic easy axis of the front end portion on the ABS plane is oriented in the film thickness direction of the front end portion, a concave portion is formed in the lower pole layer at a position separated from the ABS plane, the concave portion is filled with a nonmagnetic material, and the gap depth between the upper pole layer and the lower pole layer is determined by the concave portion.
The gap depth is determined not by the distance from the ABS plane to the front end of the first flattening layer but by the distance from the ABS plane to the margin of the concave portion. Because the concave portion is formed in a flat lower pole layer, no problem occurs in the photolithography process for forming the concave portion. Moreover, a resist frame pattern for forming the front end portion of the upper pole layer is not increased in film thickness or it is not overexposed because the first flattening layer can be sufficiently separated from the ABS plane. Therefore, it is possible to decrease the width of the front end portion of the upper pole layer. Even if decreasing the width, the frequency response for recording becomes the magnetization rotation mode because of the above reason.
The thin-film magnetic head in claim 3 is produced by forming a lower shielding layer, read gap layer holding an MR magnetosensitive element facing to an ABS plane, a shared pole layer serving as an upper shielding layer and a lower shielding layer, and write gap layer laminated in order on an insulating substrate, by forming a first flattening layer, a coil pattern layer, and a second flattening layer laminated in order on the write gap layer, and by forming an upper pole layer on the write gap layer at least nearby the ABS plane. Moreover, the upper pole layer is configured of a front end portion facing to the ABS plane and a yoke portion connected to the front end portion through a junction, magnetic easy axis of the front end portion on the ABS plane is oriented in the film thickness direction of the front end portion, a concave portion is formed on the shared pole layer at a position separated from the ABS plane, the concave portion is filled with a nonmagnetic material, and the gap depth between the upper pole layer and the lower pole layer is determined by the concave portion. That is, the thin-film magnetic head of claim 3 is an MR-inductive composite-type thin-film magnetic head constituted by combining an MR reproducing head with an inductive recording head.
Thin-film magnetic heads in claims 4 to 19 are respectively configured by restricting some of the components of the thin-film magnetic head in claim 1, 2, or 3. Magnetic storage apparatus in claims 20 to 25 are respectively configured by using the thin-film magnetic head in claim 1, 2, or 3.
The thin-film magnetic head in claim 4 uses the thin-film magnetic head in claim 3 in which the MR magnetosensitive element is the GMR type. The GMR magnetosensitive element is produced by forming of a Ta film (3 nm), an NiFe film (8 nm), a CoFe film (1 nm), a Cu film (2.5 nm), a CoFe film (3 nm), and NiMn film (30 nm) laminated in order on the lower shielding layer side. The MR magnetosensitive element has a magneto-resistance ratio of approx. 5% that is approx. two times larger than that of a conventional MR magnetosensitive component and therefore, suitable for a narrow-track high-density reproducing magnetic head.
As for the thin-film magnetic head in claim 5, the lower shielding layer of the thin-film magnetic head of claim 3 is formed through the sputtering method. The lower shielding layer, for example, is formed by forming an amorphous CoTaMo film through sputtering and heat-treating the film in an anisotropy-providing magnetic field at 350 [degrees centigrade], and then forming a shielding pattern shape through ion milling. When the lower shielding layer uses a sputtered film, the surface of the film is smoother than that of an NiFe film formed through the plating method because the crystal grain size is smaller than that of the NiFe film. Therefore, the characteristic of an MR magnetosensitive element formed on the lower shielding layer is improved.
The thin-film magnetic head in claim 6 uses the thin-film magnetic head in claim 1, 2, or 3 in which the front end portion of the upper pole layer is made of a material having a saturation flux density of at least 1.6 T or more. This type of the material includes a CoFeNi-based material having a saturation flux density of 1.8 T or more. Therefore, it is possible to compensate decrease in recording magnetic field strength generated due to decrease of a recording track width and realize a magnetic head suitable for narrow-track recording.
As for the thin-film magnetic head in claim 1, 2, or 3, the film thickness of the front end portion on the ABS plane is assumed as t and the front end portion width vertical to the film thickness t is assumed as W. An inequality of t greater than W is effectuated for the thin-film magnetic head of claim 7 and an inequality of t greater than 3 W is effectuated for the thin-film magnetic head of claim 8. When the inequality of t greater than W is effectuated, the shape anisotropy due to the difference between demagnetization fields is formed in the film thickness direction. To form magnetic easy axis due to the shape anisotropy in the film thickness direction, it is preferable that the inequality of t greater than 3 W is effectuated when considering an intrinsic magnetic anisotropy and a strain induction anisotropy due to a stress of a pole height lapping or the like.

Thin-film magnetic head and magnetic storage apparatus using the same


A machine for extinguishing fires, using materials that are excavated and thrown directly from the ground includes a brush cutting module with knives and lateral panels, an excavating module comprising a cutter with spikes, and a throwing module formed by a flywheel mounted on a rotary shaft and provided with radial blades, allowing the excavated material to be thrown through openings in the throwing module. The position of the openings can be adjusted and the excavated materials can be thrown in one direction or another.

Various types of autonomous machines used in extinguishing fires are known, i.e. having power means to operate, both for moving the machine and for actuating the different components of the machine to perform the brush cutting, excavation and throwing of ground, such that a specific type of machines include a front cutter bar for cutting bushes and trees, followed by a bulldozer to remove obstacles, and then a milling cutter for excavating and crushing the ground, leaving it "in situ", such that after said milling cutter there is arranged a harvesting knife for lifting up the excavated material, also having a chain or chains with buckets for loading and lifting up the excavated material collected by the aforementioned knife, said material reaching a rotary receiving hopper the function of which is to collect and deliver the material to a throwing-crushing element in correspondence with the rear part, wherein the throwing-crushing element has the purpose of throwing the material to the fire to be extinguished, having the particularity that this throwing-crushing element is mounted on a rotary platform.
In machines of this type, the throwing element has a single, fixed-size outlet opening, such that in order to throw the stream of material vertically, the throwing element itself moves, being powered laterally and made up of a single flywheel carrying the corresponding blades for crushing and throwing, and, in order to reach the horizontal angles, the platform on which the throwing element is fixed is used.
The type of machines referred to above are structurally complex, heavy and expensive, where the transmissions to the various hydraulic drive elements even further increase the cost of the assembly of the machine. Furthermore, the cutter bar, the milling cutter and the receiving hopper, with the throwing-crushing element, are linked with means for lifting up and lowering such components, for the purpose of trying to achieve the best and most effective functionality thereof, such that those lifting and lowering means undoubtedly affect the final cost of the machine, in addition making it more complex.


A device with a base housing part and two slidably suspended cover parts that can move in opposite directions between a retracted position in which they substantially abut one another and conceal an operating face and an extended position in which they do not conceal the operating face. At least one of the covers can also assume an intermediate position between the retracted position and the extended position in which in which a portion of the operating face is not concealed.

Mobile electronic devices with two housing parts that can be moved between a retracted position in which a keypad is concealed and an extended position in which the keypad is not concealed are known in the art.
There is often a need to protect the display of the mobile device from being scratched or damaged and there is also a need to check right away who is calling, but many times the user cannot take the call at that specific moment, but can call back later. This problem is the same for SMS and MMS and e-mail. There is also a need to have devices that look sophisticated and are relatively small in size, especially when they are carried and not in use.

Electronic device with movable housing parts


A method forms a helmet liner which during its formation is fitted to the head of the user, by forming an inflatable liner element of extensible sheet material approximately conforming to the shape of the interior surface of a helmet shell, providing the element with respective foam filling and vent passages, the vent passages serving to expel air from the liner as foam filling proceeds, mounting the liner element in the helmet on the head of the user, supplying foam to the foam filling passages to inflate the liner element, expel air therefrom and conform the element at an outer surface to the shape of the interior surface of the helmet shell and at an inner surface to the shape of the head of the user, allowing time for curing of the foam admitted to the liner element, and severing parts of the vent and foam filling passages projecting from the liner. The liner element can embrace a forehead portion only of the head of the user or a further element which embraces a rear part of the head can be added. In another form embodiment, the liner element may cover the crown, front and rear of the head of the user.

This invention relates to helmet liners and a method of making such liners which in their formation are fitted to the head of the user. In specialised helmets such as are employed, for example, by aircrew personnel the proper protection and comfort of the user dictates that the helmet is an accurate fit and that the closeness of the fit be accomplished by use of a shock absorbing liner which is tailored to the shape of the head of the user and to the interior of the helmet shell. References herein to the interior of the helmet shell are to be understood as referring to the inner surface of the shell or of a fixed impact absorbing lining material provided in the shell.


This disclosure describes, in part, techniques for establishing network-based data communications (e.g., voice calls, video calls, etc.) between a user device of a user and a remote device of another user, and transitioning the data communications to a different user device of the user based on various types of information. In some examples, the user devices may be located in one or more environments of the user, and the data communications may be transitioned between the user devices based, at least in part, on a location of the user in the environment(s) relative to the multiple devices. For instance, if a user device is performing data communications with the remote device, but it is determined that the user has moved into a closer proximity to another user device, the performance of the data communications may be transitioned to the other user device to which the user is in closer proximity.

As the capabilities of computing devices continue to evolve, many different ways have been introduced to allow users to interact with computing devices, such as through mechanical devices (e.g., keyboards, mice, etc.), touch screens, motion, and gesture. Many computing devices are now capable of receiving and responding to voice commands, including desktops, tablets, entertainment systems, and portable communication devices. Due to their usefulness, it may be the beginning of an emerging trend for users to place multiple voice-enabled devices throughout their homes to receive and respond to their voice commands in different locations in their homes. Having multiple voice-enabled devices placed throughout an environment increases the complexity of determining which voice-enabled device is to respond to a voice command or otherwise interact with a user. Provided herein are specific technical solutions for improving existing systems so they are more useful for users having multiple voice-enabled devices.

This patent is subject to a terminal disclaimer.

Selecting user device during communications session


Systems and methods of blocking phishing attempts in a computer network, including receiving a list of assets of the computer network, wherein each asset is associated with at least one computer network address, generating at least one address permutation on the at least one computer network address of each asset of the computer network, wherein the generated at least one address permutation is different from the address associated with each asset of the computer network, receiving a communication request at a gateway server of the computer network, determining a destination address of the communication request, comparing the determined destination address with the at least one address permutation, and when the determined destination address is the same as at least one address permutation, blocking the communication request at the gateway server.

Phishing attempts have become very common in recent years, where sensitive information (e.g., account details or passwords) are maliciously retrieved from users while disguising as a trustworthy entity. For instance, such attempts are typically carried out with email spoofing and/or direction of users to fake websites.
Some commercially available solutions employ a mechanism to detect phishing domains based on their similarity to a general concept of known phishing domains without considering the customer's original domains However, such general methods do not consider the original information of the potential target, for example the domains that the attacker attempts to disguise to.

System and method for blocking phishing attempts in computer networks


A plasma arc torch for cutting metal with the heat of a constricted arc and removing the molten material with a jet of hot ionized gases comprises a nozzle assembly in the torch includes a nozzle base and an insulator with a constricting orifice. The base and insulator are spaced from each other to form a flow path for a coolant such as water. An interference fit between the base and the insulator exerts a radially outward force on the insulator to enable the base and insulator to be assembled and disassembled with a pressing or pulling force in the approximate range of 0.3 to 16.0 pounds.

This invention relates generally to plasma jet cutting equipment, and more specifically to a novel and improved nozzle assembly suitable for use in plasma arc cutting torches.
In transferred arc plasma jet cutting equipment, a device, commonly referred to as a "torch", uses gas flow and heat generated by an electric arc to "cut" through a metallic workpiece. A direct current electrical arc and ionized gas, between an electrode (the cathode) located in the center of the torch and the workpiece (the anode), create a jet of hot plasma through a constricting nozzle located between the electrode and the workpiece. The jet has sufficient heat and force to slice through the struck portion of the workpiece.
Current state-of-the-art nozzles are constructed from an electrically conductive material, usually copper. Unfortunately, when significant electrical power is applied to the cutting operation, there can occur a phenomenon known as "double arcing", in which the plasma arc does not pass directly through the center of the nozzle orifice, but instead deflects to the nozzle wall before reaching the workpiece.
The most common technique for combating double arcing is to add a ceramic electrical insulator with an orifice between the nozzle and the workpiece. Present designs position the insulator slightly away from the nozzle to form a gap between the two components around the orifice. This provides a conduit for cutting shield gases and cooling gases or water to be introduced for such purposes as improving the quality of the plasma arc cut, cooling the nozzle to extend its life, and helping constrict the size of the cutting arc for deeper or better cuts. The size of the gap between the nozzle and insulator is a very important determinant to the quality of cut and useful lives of the nozzle and insulator. Popular designs in plasma arc torches therefore utilize a nozzle assembly of two or more components, including a copper nozzle base and a ceramic insulator. The gap between these components is carefully controlled. These designs also provide a flow path for injecting coolant water into the plasma orifice area.
To assure a good quality of cut, and a long life for the components, the orifices of the insulator and the nozzle base must remain concentric with each other at all times, and the thickness of the coolant water flow path, as determined by the gap between the nozzle base and insulator, must be maintained within very close tolerances. Heretofore, these requirements have been achieved either by permanently bonding the insulator to the nozzle base, with glue for instance, or by assembling the insulator to the nozzle base with additional components. Typically, these include a centering sleeve fitted around the outside of the insulator and nozzle base to assure concentricity, and a spacer fitted between the nozzle base and insulator to assure a proper gap for coolant water flow.
There are several significant disadvantages to the above described plasma torch nozzle assemblies. Where the nozzle assembly, the nozzle base and the insulator are permanently attached to one another, the nozzle base frequently wears out long before the insulator under normal cutting operations. On the other hand, material irregularities in the workpiece may cause the insulator to contact the workpiece accidentally and produce irreparable damage to the insulator without harming the nozzle base. In either case the torch operator must discard and replace the entire nozzle assembly. Consequently, more money is spent for replacements than is truly necessary.
In nozzle assemblies having additional detachable components, a significant disadvantage is the overall cost of producing and assembling the additional components. Also, where a centering sleeve is fitted around the outside of the insulator with an inwardly directed gripping force, it is directly in the flow path of the cooling water and therefore interferes with flow. The centering sleeve must therefore include water passage holes, gaps, notches or spaces, all of which add significantly to manufacturing costs. Another disadvantage in using additional components is the difficulty of reassembling them with the nozzle and insulator after the torch operator has replaced the worn or broken component. Replacing only one component of the assembly requires painstaking re-balancing of the various components upon each other in order to complete reassembly successfully. Consequently, more is expended at the outset to maintain a complete inventory of nozzle assemblies.

Nozzle assembly for plasma arc cutting torch


A method for displaying temporal data on a portable device is presented. The method includes converting the temporal data to clock coordinates to generate a clock data set. In addition, the method includes presenting a clock plot representative of the clock data set on a dial of a clock. Systems and computer-readable medium that afford functionality of the type defined by this method are also contemplated in conjunction with the present technique.

This disclosure relates generally to clinical information systems, and more particularly, to systems and methods for displaying temporal data on small mobile devices.
Patient care has become increasingly complex with the widespread use of advanced technologies in routine care. Furthermore, healthcare providers are required to keep track of a staggering amount of information, and their failure to do so may have a detrimental effect on patient care. A solution to this problem may include a Clinical Information System (CIS). As will be appreciated, the CIS may be configured to aid in the acquisition, storage, manipulation, and distribution of clinical information throughout a caregiving facility like a hospital. In other words, the CIS may be employed to collect and store information associated with one or more patients in a caregiving facility. A clinician may then access the stored patient information to monitor a status of the patients and/or to make a diagnosis.
In certain situations, it may be desirable for the clinician to monitor temporal patient data outside the caregiving facility. Advances in digitization of data have allowed the patient data to be available to the clinician outside the caregiving facility. Vital clinical information, once confined to bedside monitors, is becoming easily available to caregivers, such as clinicians, at remote locations with the advent of CIS employing Web portals. In addition, clinicians today have access to patient data in their offices and/or homes. In other words, the clinician may access patient data from his/her home, office, or any other location that is remote from the caregiving facility. More recently, the patient data may also be accessed via a mobile device that has a relatively small display, where the mobile device may include a cell phone, a pager, a personal digital assistant (PDA), or the like.
Furthermore, in certain situations, it may also be desirable for the clinician to monitor temporal patient data outside the caregiving facility. As will be appreciated, the temporal patient data may be representative of patient data acquired over a period of time. For example, temporal clinical data may include patient data such as vital signs like heart rate (HR), blood pressure (BP), blood oxygenation level (SaO2), lab results, or infusion volumes. Moreover, temporal patient data like the heart rate and blood pressure are collected frequently on hospitalized patients and have traditionally been presented graphically as an X-Y time series plot on Clinical Information Systems, thereby allowing the clinician to monitor patient data over an extended period of time.
Moreover, it may also be desirable to view the temporal patient data outside the caregiving facility on a mobile device, such as a cell phone, a pager, or a PDA, for example. However, one of the biggest challenges of displaying temporal patient data on a mobile device, such as a PDA, is an effective display of the temporal patient data on a relatively small display of the PDA. Displaying the time-series data on screen of a PDA or a screen of a cell phone may be visually taxing or may require scrolling. In addition, visualization of temporal data on the display of a mobile device, such as a PDA, a cell phone, or a pager, may disadvantageously result in loss of granularity of data and/or resolution.
It may therefore be desirable to develop a design that allows efficient display of temporal data on a relatively small display of a mobile device. More particularly, there is a need for an approach for efficiently displaying low-density and/or high-density temporal data on small display devices, such as cell phones or personal digital assistants (PDAs), thereby enhancing clinical workflow as the clinician may easily visualize a snapshot of relevant patient data.

Method and system for enhanced display of temporal data on portable devices


Disclosed is a process for the reductive carbonylation of methanol to produce acetaldehyde. The process includes conducting the reaction to produce acetaldehyde in the presence of a catalyst comprising a complex composed of cobalt, an onium cation and iodide in a ratio of 1:2:4, a phosphine ligand, and a phosphonium iodide. The reductive carbonylation reaction produces a crude reductive carbonylation product substantially free of methyl iodide.

Cobalt can catalyze the formation of acetaldehyde from methanol, carbon monoxide, and hydrogen, a reaction known as methanol reductive carbonylation. For example, it was disclosed by Wender et al., Science, 113, (1951), 206-207, that a cobalt carbonyl catalyst system could be used. However, the product of the disclosed process was primarily ethanol, together with a small amount of acetaldehyde. It was later shown that the addition of iodide to a cobalt-containing catalyst system increased the amount of acetaldehyde produced. Iodide is typically added as a co-catalyst (also commonly referred to as a promoter) to the reaction in a form such as hydrogen iodide (a strong acid), methyl iodide, elemental iodide, or as an iodide salt such as lithium iodide or sodium iodide.
Addition of commonly-used industrial iodide co-catalysts in these reactions often leads to formation of dimethyl ether as well as free methyl iodide in the crude reductive carbonylation product. Methyl iodide is an undesirable co-product due to the difficulty in separating it from the aldehyde product as well as its toxicity. Current methanol reductive carbonylation processes carefully balance the amount of iodide containing compounds added to the reaction to obtain optimized reaction rate and conversion while limiting dimethyl ether and methyl iodide formation.
There is a need for an improved catalyst system which will allow reasonable reductive carbonylation reaction rates as well as little to no methyl iodide in the crude reductive carbonylation product. There is also a need for an inexpensive catalyst for the carbonylation of alcohol that can replace the typical rhodium catalyst or iridium/ruthenium catalyst while producing a substantially methyl iodide free crude reductive carbonylation product.

Methyl-Iodide-free carbonylation of methanol to acetaldehyde


A golf ball putter having a golf club assembly which includes a vertical member having a planar ball-striking surface integrally united with a horizontal sole member at substantially a right angle, a heel and toe balancing weight mounted on the rearward surface of the vertical member near the heel, a horizontal sight connected to the vertical member and supported by a vertical upright connected to the horizontal sole member and weight receiving apertures, included in the event the user prefers a personal "feel" to the putter, but the added weights shall not disturb the balance provided by the heel and toe balancing weight. The golf club assembly is controlled by a manipulating assembly including a hosel attached to an upper surface of the horizontal shoe member rearwardly of the center of gravity of the golf club assembly, a shaft is connected to the hosel and a hand grip is connected to the shaft.

Putting the golf ball into the hole or cup is an integral part of the game of golf and therefore a great deal of time and money has been spent on innovations to make the best putter. Some of the innovations appear to focus on the psychological aspect while others have a scientific basis and it is these that are more likely to provide improved performance on the part of individual golfers. While both alignment and force may be conscious acts of the golfer the aid to accurate sustained alignment and an improved potential for a true pendulum type motion are provided herein. Research in this area has revealed that when a pivotal putter shaft in a vertical position is attached to a putter head assembly at a point directly behind and rearward of the center of gravity of the putter head assembly the assembly will gravitate toward a point even with the pivot point. This initial tendency of the clubhead assembly to move rearward should facilitate accuracy for the duration of the backswing and the subsequent reversal in tendency to pull forward of the shaft, not only facilitates the downswing but greatly assists in overcoming the obvious disadvantage of rearweighted putters commonly found today by applying a predictable and accurate force toward a square face alignment position for the latter part of the backswing and for the duration of the downswing.
A search of the prior art has revealed U.S. Pat. Nos. 4,265,451, 4,325,553 and 4,898,387. U.S. Pat. No. "451" reveals a neck member above the club head which includes a heavy wedge-shaped portion extending forward of the ball-striking surface in the direction of desired golf ball travel. This configuration is deemed to pull as well as push the club head through the stroke. This club differs from applicants in that this device has its center of gravity in front of the ball striking surface while applicants device has its center of gravity rearwardly of the ball striking surface. U.S. Pat. No. "553" is designed and balanced so that the bulk of the effective mass of the putter is as far as possible from the center of the striking face while applicants device has its effective mass distributed in an obvious and even manner relative only to the one balancing weight and the hosel. U.S. Pat. No. "387" is directed to a putter club head having a maximum moment of inertia about the vertical axis of rotation at the center of mass between the heel and toe to resist twisting forces while applicants device operates effectively without massive weight placement producing a high moment of inertia due to applicants shaft attachment being directly rearward of the center of gravity of the club head assembly.


A system for dispensing and filtering fluid is disclosed, in which the fluid flow path is substantially vertical from the fluid inlet through fluid dispense. Substantially all wetted surfaces are Teflon® or some similar non-contaminating fluid, for applications such as cleanroom processes. A valve and a filter chamber are incorporated into a pump head to simplify the flow path and reduce potential contamination points. Preferred methods, and chips or other microelectronic devices fabricated from the apparatus or methods, are also disclosed.

This invention relates to a pumping system useful in dispensing fluids, especially those that are expensive, viscous, high purity, and/or sensitive to molecular shear. The invention also relates to microelectronic components such as silicon chips and wafers, microelectronic substrates, and circuits fabricated by such pumping systems and methods, including the potentially improved quality and yield of such products achievable with the invention as compared to prior art systems.
General aspects of the relevant background of the invention are discussed in prior U.S. Pat. Nos. 5,167,837; 5,772,899; and 5,516,429. Among other things, the invention has numerous applications, but is especially useful in the microelectronics industry. The trend in that industry continues to be to squeeze greater quantities of circuitry onto smaller substrates. Circuit geometries continue to shrink, the use of expensive materials continues, and the corresponding need for decontaminated "cleanroom" environments and equipment for manufacturing, filtering, and processing continues and even increases. Perhaps as importantly, the need for improved yield of final product continues, for economic and other reasons.
The equipment and methods of the aforementioned U.S. Pat. Nos. 5,167,837; 5,772,899; and 5,516,429 addresses many situations and applications very well. The present invention is directed to further improvements in that technology, as well as potential applications of such improvements in unrelated technologies.
Among other things, further simplification and upright orientation of the flow path for the processed fluids through a pumping and dispensing system can reduce the risk of contamination, air entrapment, or similar concerns, while providing similar or improved reliability and precise control for desired filtration, dispense, and other handling of the process fluids. Further manufacturing and design improvements in the instant invention allow the entire process fluid flow path to be coated or machined from Teflon® or some similar non-contaminating material, further reducing the likelihood of any contamination problems.
As indicated above, many problems were addressed and solved by the aforementioned U.S. Pat. Nos. 5,167,837, 5,516,429, and 5,772,899. Among other things, those devices introduced a diaphragm-type fluid dispense system which, in certain embodiments, included two separate computer-controlled pumps to dispense precise amounts of fluid. However, the preferred embodiments in those patents show the process fluid traveling in a somewhat meandering path through the pump system. In certain applications, that path does not afford optimal venting for any contaminating air bubbles that may become entrapped in the fluid or the system. For example, some small amount of air bubbles may be unavoidably introduced when the source fluid container is periodically changed, even if no re-priming is required. Portions of the flow path that are metal or otherwise relatively potentially contaminating result in some risk (however small) of corresponding undesirable contamination of the fluid.
As indicated in those prior patents, such bubbles or contaminants could potentially compromise the end product to some degree in some small percentage of applications. Alternatively, such bubbles or contaminants might require some period of "flushing" bubbles from the system upon changing the source fluid container, for example, or might otherwise compromise the accuracy of the fluid dispense system (again, in a small percentage of applications and situations). Although those prior patents and inventions function well in that regard and are a dramatic advance over the prior art before them, and although those prior patents can be readily adapted to deal with the aforementioned potential problems, the instant invention provides improvements in that regard.
Other benefits derive from simplifying the flow path of the fluid. By simplifying and reducing the number of components involved in the system, assembly and maintenance can be correspondingly simplified. Perhaps more importantly, the number of connection points, seals, fittings, and related potential leak-spots can be reduced, thereby directly reducing the risk of contamination, air-entrainment, or similar problems. Additionally, reducing and realigning the fluid flow path can reduce the size of the "footprint" for the housing of the system and otherwise make the system more compact as compared to prior art systems, thereby correspondingly reducing valuable factory space for the users of the pump system.

Apparatus and methods for pumping high viscosity fluids


Disclosed is a multiport SRAM cell. The cell state may be switched by controlling the potential on a single bit line only. A true dual port SRAM cell (in which the two ports may be accessed nearly simultaneously without needing peripheral arbitration logic) employs two cross-coupled inverters, two bit lines, two word lines, and two access transistors. The SRAM cells employ internal "pseudo inverters" that can be independently powered on and off. By powering one of them off during the write operation, the internal conflict associated with changing the value of a stored bit is avoided. Each pseudo inverter may be powered on and off via a pseudo ground or a pseudo Vdd line which controls the potential to locations where ground or Vdd are normally supplied to CMOS inverters.

The present invention relates to dual-port static random access memory (SRAM) cells. More particularly, the invention relates to dual-port SRAM cells having mono-bit line operation on each port and inverters coupled to local pseudo-ground lines.
Dual Port SRAMs ("DPSRAMs") find widespread use in the electronics industry. Conventional DPSRAMs employ either an 8-transistor cell or a 6-transistor cell. Each has its own advantages and disadvantages. Generally, 6-transistor cells are compact but they operate more slowly. The 8-transistor cells operate faster (they are true dual port cells employing a separate word line for each port), but they occupy more space.
Conventional 6-transistor DPSRAMs require only four N channel transistors, two P channel transistors, and two metal bit lines running on top of the cell. A conventional 6-transistor DPSRAM is illustrated in FIG. 1. It operates as follows.
In standby mode, an SRAM cell 2 statically holds a bit value on two cross-coupled CMOS inverters 4 and 6. The output of inverter 4 feeds the input of inverter 6 and the output of inverter 6 feeds the input of inverter 4. Thus, a first logical bit value is held on the left side of cell 2 and the complementary value is held on the right side of the cell. During standby ode, no information is being read from or written cell 2. Thus, access to the cell is blocked. This is accomplished by holding two NMOS access transistors 8 and 10 in a non-conductive state. One source/drain diffusion of transistor 8 is connected to the left port of cell 2 and one source/drain diffusion of transistor 10 is connected to the right port of cell 2. The other source/drain diffusion transistor 8 is connected to a bit line 14 and the other source/drain diffusion of transistor 10 is connected to a bit line 16. In addition, a word line 12 is connected to the gates of both access transistors 8 and 10 and thereby controls the gate potential of both of these transistors. During standby mode, the potential on a word line 12 is held below the threshold voltage of NMOS transistors 8 and 10.
During read mode, bit lines 14 and 16 are initially precharged to an intermediate potential such as Vdd/2, for example. Then, access transistors 8 and 10 are switched on by applying a potential above the threshold voltage to word line 12. At that point, the voltage on the bit lines changes to reflect the value stored on cross-coupled inverters 4 and 6. Assume, for example, that the left side of the cross-coupled inverters has a "high" value ("1") and the right side has a "low" value ("0"). In that case, when access transistors 8 and 10 are turned on, the potential on bit line 16 drops from Vdd/2 to approximately 0. Concurrently, the potential on bit line 14 increases from Vdd/2 to a higher value. That higher value is not quite Vdd ("1"). Rather, because of the body effect associated with NMOS transistor 8, the potential on bit line 14 increases to at most Vdd-Vt. Vt is the threshold voltage of NMOS transistor 8.
While word line 1 is set of Vdd (or other value over the threshold voltage of the NMOS transistors), a sense amplifier detects and compares the voltages on bit lines 14 and 16. From this comparison, it can determine what value is stored on cell 2.
During the write operation, bit lines 14 and 16 are set at complementary voltages. For example, if bit line 14 is set to a high voltage, bit line 16 is set to a low voltage, or vice versa. Assuming for the moment that the cell is storing the low value on the left side and a high value on the right side and that a new value is to be written in which the low value is on the left side and the high value is on the right side, than a low value (0) is applied to bit line 14 and a high value (Vdd) is applied to bit line 16. Then, word line 12 is set to Vdd so that access transistors 8 and 10 are switched on. On the left side of cell 2, the 0 is transferred to the cross-coupled inverters essentially at the level of 0. On the right side, however, the value of Vdd (high) is not transferred at that level. Rather, the transfer potential will at most be Vdd-Vt because of the body effect as explained above.
Because the system is attempting to switch the state of the cross-coupled inverters 4 and 6, a conflict arises, at least temporarily, within cell 2. Specifically, because the output of inverter 4 is held at 0, it is difficult to switch the value on the right side of the cell to Vdd, especially given that the level transferred from bit line 16 is only Vdd-Vt. The problem is compounded because of the high static noise margins employed to keep the values on SRAM cells stable. Because of these effects, it is virtually impossible to switch the state of the right side of cross-coupled inverters 4 and 6 from low to high by simply applying a high value to bit line 16. The solution is to force a 0 (low) on the other side of the memory cell. As two complementary values (high and low) are written into the cell, two complementary bit lines are necessary to make the operations possible. To effect the transition, bit lines 16 and 14 must "push and pull" at the same time.
In this 6-transistor cell, it is impossible to use two ports at the same time as they share a word line and bit lines. That is, both bit lines and the word line must participate in any read or write operation. Thus, the ports must be selected one after the other, thereby reducing the available speed by a factor of 2. Further such access requires peripheral arbitration logic in order to handle the different selections. Such extra logic complicates the device design.
A standard 8-transistor DPSRAM cell 21 is depicted in FIG. 2. Such cells are commonly used in FIFOs and other applications. Cell 21 includes cross-coupled inverters 23 and 25 arranged in the same manner as inverters 4 and 6 in cell 2. This cell includes two "true" ports. A first port is controlled by a word line 27 in conjunction with bit lines 29 and 31. Word line 27 controls the gates of two NMOS access transistors 33 and 35. A second port is controlled by a word line 37 and bit lines 39 and 41. Word line 37 controls the potential on the gates of two NMOS access transistors 43 and 45. As shown, access transistors 33 and 35 of the first port are arranged at opposite sides of cell 21 and NMOS access transistors 43 and 45 of the second port are also arranged at opposite sides of the cell.
In operation, cell 21 acts much like cell 2, except that because it is controlled by two "true" ports, each with its own compliment of a word line, two bit lines, and two access transistors, it can be accessed through each port nearly simultaneously. In stand-by mode, word lines 27 and 37 are held at a low level. During read or write through the first port, word line 27 is set to a high level (e.g., Vdd). During a read operation through the first port, bit lines 29 and 31 are precharged to Vdd/2 and then, after word line 27 is set high, their outputs are ready by an SRAM sensing circuit and compared. During a write operation, cross-coupled inverters 23 and 25 are pushed and pulled simultaneously by applying complementary values on bit lines 29 and 31 while word line 27 is held high. The second port operates in essentially the same manner. During read, bit lines 39 and 41 are precharged to Vdd/2. Then, when word line 37 is set high, the values on word lines 39 and 41 (now affected by the internal value stored on the cross-coupled inverters) are compared by a sensing circuit. Finally, during the write operation through the second port, complementary values are applied to bit lines 39 and 41 while word line 37 is set high.
While this 8-transistor cell has found wide application, its major problem is the large are that it occupies. It requires six N channel transistors, two P channel transistors, and four metal bit lines running on top of the cell.
Other multiport cells have the same issues. In fact, they can be even more difficult to implement because, in general, the static noise margin is intentionally increased to compensate for the effects of additional access modes. So large cell size becomes the only known option.
For the above reasons an improved high density SRAM is needed.

Dual port SRAM cell having pseudo ground line or pseudo power line


An input image is enhanced to include spatial frequency components having frequencies higher than those in an input image. To this end, an edge map is generated from the input image using a high band pass filtering technique. An enhancing map is subsequently generated from the edge map, with the enhanced map having spatial frequencies exceeding an initial maximum spatial frequency of the input image. The enhanced map is generated by applying a non-linear operator to the edge map in a manner which preserves the phase transitions of the edges of the input image. The enhanced map is added to the input image to achieve a resulting image having spatial frequencies greater than those in the input image. Simplicity of computations and ease of implementation allow for image sharpening after enlargement and for real-time applications such as videophones, advanced definition television, zooming, and restoration of old motion pictures.

1. Origin of the Invention
The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 USC .sctn. 202) in which the Contractor has elected to retain title.
2. Field of the Invention
The invention relates to signal processing techniques, and more specifically to techniques for the enhancement of edges in a temporal signal containing information in one or more dimensions. The edge enhancing techniques taught herein are advantageously applied to television, and other, related applications.
3. General Description of Related Art
A wide variety of techniques have been developed for processing and filtering signals, particularly signals representing two-dimensional images. In particular, many image processing techniques are provided for enhancing the clarity of a blurred image. An image may appear blurred for a number of reasons. An original sharp image may be blurred during transmission due to noise or other factors. In other circumstances, the original image is itself insufficiently clear and techniques are employed to sharpen the original image. Even in circumstances where an image is not actually blurred, the image may appear blurred due to human visual perception considerations.
If an image is blurred or degraded by a well-understood process, such as shot noise occurring during transmission, the image can usually be enhanced by developing a model of the source of degradation, then reconstructing the original image using the model. However, in many circumstances, a source of degradation of the image cannot be modeled and, hence, the image cannot be faithfully reconstructed.
In many circumstances, a blurred or perceptually blurry image may be enhanced, by enhancing high frequency spatial components of the image. For example, high frequency components are usually degraded more significantly during transmission than low frequency components. Hence, enhancement of high frequency components may be effective in compensating for high frequency components lost during transmission. Moreover, as will be described in more detail below, because of human visual perception considerations, an image having enhanced high frequency components simply appears sharper than an image without enhanced high frequency components.
Accordingly, various image processing techniques have been developed for modifying or supplementing the high spatial frequency components of an image, either for the purpose of providing a perceptually clearer image or for compensating for degradation in an image caused during transmission.
In the following, several such image processing techniques are summarized and general visual perceptual considerations are described. Although the following discussion is primarily directed to two dimensional time-varying or "temporal" signals, the techniques are, unless otherwise noted, generally applicable to n-dimensional information components defined by applied temporal signals that have been sampled and converted to sample streams with level-values which define the information. For optical image processing n equals two, and the information component is a visual image.
4. Perception Considerations
It has been found that the human visual system appears to compute a primitive spatial-frequency decomposition of luminous images, by partitioning spatial frequency information into a number of contiguous, overlapping spatial-frequency bands. Each band is roughly an octave wide and the center frequency of each band differs from its neighbors by roughly a factor of two. Research suggests that there are approximately seven bands of "channels" that span the 0.5 to 60 cycle/degree spatial-frequency range of the human visual system. The importance of these findings is that spatial frequency information more than a factor of two away from other spatial frequency information will be independently processed by the human visual system.
An important parameter of a signal processing scheme is the highest spatial frequency of interest f.sub.0. In general, the selection of f.sub.0 is based on the desired application. When the temporal signal has two dimensions and the signal defines a visual image, selection of f.sub.0 is based on human visual perception considerations. Thus, if the highest spatial frequency of interest of the image is not greater than f.sub.0, the highest frequency band will cover the octave from f.sub.0 /2 to f.sub.0 (having a center frequency at 3f.sub.0 /4); the next-to-highest frequency band will cover the octave from f.sub.0 /4 to f.sub.0 /2 (having a center frequency at 3f.sub.0 /8), and so on.
It has been further found that the spatial-frequency processing that occurs in the human visual system is localized in space. Thus, the signals within each spatial-frequency channel are computed over small sub-regions of the image. These sub-regions overlap each other and are roughly two cycles wide at a particular frequency.
If a sine wave grating image is employed as a test pattern, it is found that the threshold contrast-sensitivity function for the sine wave grating image rolls-off rapidly as the spatial frequency of the sine wave grating image is increased. That is, high spatial frequencies require high contrast to be seen (.apprxeq.20% at 30 cycle/degree) but lower spatial frequencies require relatively low contrast to be seen (.apprxeq.0.2% at 3 cycle/degree).
It has been found that the ability of the human visual system to detect a change in the contrast of a sine wave grating image that is above threshold also is better at lower spatial frequencies than at higher spatial frequencies. Specifically, an average human subject, in order to correctly discriminate a changing contrast 75% of the time, requires roughly a 12% change in contrast for a 3 cycle/degree sine wave grating, but requires a 30% change in contrast for a 30 cycle/degree grating.
The perceived inherent sharpness of an image depends on the ratio of the maximum present spatial frequency of interest f.sub.0 to the solid angle of view subtended by the image with respect to the human eye. This solid angle equals approximately the area of the image divided by the viewer's distance from the image.
When an image is expanded (or enlarged) e.g. by a linear factor of two, its two-dimensional area is expanded by a factor of four. Expansion is accomplished by inserting additional pixels (or samples) in the picture. Typically the newly inserted samples are assigned level-values that are calculated to be the averages of the level-values of their neighboring samples, and the spatial frequencies are accordingly halved. Therefore, the ratio of the maximum frequency of interest f.sub.0 to the viewing angle is accordingly degraded, unless the viewer "steps back", i.e. increases the distance from the image by the same linear factor that the image was expanded by. This would decrease the solid angle and restore the perceived inherent sharpness of the image. Consequently, an image resulting from an expansion without more processing appears to a stationary viewer as having less inherent sharpness than the original, i.e., the image appears blurred. Stated otherwise, enlargement without more processing leads to an image lacking concomitant information in the higher spatial frequency bands.
5. The Burt Pyramid Algorithm for Spatial Frequency Analysis
One example of a technique for enhancing images is the Burt Pyramid Algorithm (developed by Peter J. Burt). The Burt Pyramid Algorithm permits an original high-resolution image to be synthesized from component sub-spectra images without the introduction of spurious spatial frequencies due to aliasing. The Burt Pyramid Algorithm is particularly well-suited for both analyzing a spatial frequency spectrum of images and for synthesizing an image from its analyzed sub-spectra.
The term "pyramid" as used herein, generally relates to the successive reduction in the spatial frequency bandwidth and sample density of each of the hierarchy of component images in going from the highest octave component image to the lowest octave component image.
One example of a technique for enhancing images is the Burt Pyramid algorithm. The Burt Pyramid Algorithm uses particular sampling techniques for analyzing a relatively high resolution original image into a hierarchy of N (where N is a plural integer) separate component images (in which each component image is a Laplacian image comprised of a different octave of the spatial frequencies of the original image) plus a remnant Gaussian image (which is comprised of all the spatial frequencies of the original image below the lowest octave component Laplacian image).
In the following the input image is referred to as G.sub.0, the LPF versions are labeled G.sub.1 through G.sub.N with decreasing resolutions and the corresponding edge maps are labeled L.sub.0 through L.sub.N respectively.
A stage of Burt Pyramid analysis is shown in FIG. 1. An input image (denoted as G.sub.0) is input, then convolved and decimated using a convolution filter 102, to produce a filtered decimated image G.sub.1. Sub-sampling is also generally referred to as "decimating".
The convolution filter 102 is a low pass filter that exhibits spatially localized, gradual roll-off characteristics, rather than "brick wall" roll-off characteristics. More specifically, each of the low pass filters employed by a Burt Pyramid analyzer meets each of the following two constraints. First, each of these filters employs a localized, symmetric kernel weighting function composed of at least three multiplier coefficients. Second, the multiplier coefficients of the kernel weighting function provide equal contribution; that is, all nodes at a given level contribute the same total weight to nodes at the next higher level. In the case of a three-tap filter, this means that the respective values of the three weighting multiplier coefficients of the kernel function of the filter in each dimension are respectively 0.25, 0.5, and 0.25. In the case of a five-tap filter, the values of the five weighting multiplier coefficients of the kernel function of the filter in each dimension are respectively (0.25-p/2), 0.25, p, 0.25, and (0.25-p/2), where p has a positive value.
The input image G.sub.0 is delayed by a delay element 104. The filtered decimated image G.sub.1 is re-expanded and interpolated by an expansion and interpolation filter 108. The expanded and interpolated G.sub.1 is subtracted from the delayed G.sub.0 by a subtraction element 106 to produce L.sub.0, the first order edge map, also known as Laplacian. It is noteworthy that there are many ways a Laplacian can be computed. The term "Laplacian" does not inherently signify a particular method of derivation.
The filtered decimated image G.sub.1 is subsequently input to a second stage, that is similar to the first, to produce G.sub.2 and L.sub.1, etc. Iteration continues until a desired number of pyramid levels is achieved.
The Burt Pyramid algorithm may further employ a synthesis component, that works in reverse to reconstruct the original image G.sub.0 from the remnant sampled signal G.sub.N and the Laplacian sub-spectra sampled signals L.sub.0, . . . , L.sub.N-1.
The reconstruction process involves adding to a given LPF (the remnant) version of the image, G.sub.N, the band pass images, L.sub.j (j=N-1, . . . , 0), thus reconstructing the Gaussian pyramid, level by level, up to the original input image, G.sub.0. This is a recursive process as in equation (1): EQU G.sub.j =L.sub.j +G.sub.j+1 :j=N-1, . . . , 0 (1)
where G.sub.j+1 is expanded, via interpolation, to the G.sub.j image size prior to the addition process.
Typically, the Burt Pyramid algorithm is implemented by computer in non-real time. Non-real time implementation of the Burt Pyramid algorithm by computer processing is particularly effective in processing fixed image information, such as a photograph. However, it is not particularly effective when applied to a stream of successively-occurring images continually changing in time (e.g., successive video frames of a television picture), unless special computation means are used, such as special purpose integrated circuits.
6. The Filter-Subtract-Decimate Algorithm for Spatial Frequency Analysis
An alternative to the Burt Algorithm was achieved by a Filter-Subtract-Decimate (FSD) Hierarchical Pyramid described in U.S. Pat. No. 4,718,104.
A stage of the FSD pyramid analysis component is shown in FIG. 2. As can be seen from FIG. 2, the FSD technique includes similar functional components to that of the Burt Pyramid algorithm of FIG. 1. In particular, an input image G.sub.0 is filtered by a convolution filter 202. The input image G.sub.0 is also delayed by a delay element 204, and the output image from convolution filter 202 is subtracted from a delayed version of input image G.sub.0 by subtraction element 206 to produce an edge map L.sub.0.
For an input signal comprising a sample stream of certain samples carrying information, the FSD analyzing technique involves convolving the image at every sample location with a symmetrical, localized, equal-contribution, low pass filter, n-dimensional kernel function having a low-pass transmission characteristic to derive a convolved sample stream. The convolved sample stream includes filtered samples that individually correspond to each of some of the certain samples of the input stream. The level-value of each of the filtered samples is subtracted from the level-value of that individual certain sample with which it corresponds, to derive an edge map L.sub.0. Edge map L.sub.0 comprises a first output sample stream that includes information-component samples corresponding to the input certain samples that define the band pass sub-spectrum with the particular relatively high sample density.
Unlike the Burt algorithm, convolution filter 202 of the FSD technique does not include a decimation element. Rather, a separate decimation element 205 is provided for receiving the output from convolution filter 202. Decimation element 205 operates to produce G.sub.1. Hence, decimation of the convolved image need not be performed prior to the subtraction for the delayed input image. As a result, re-expansion and interpolation before subtraction are not necessary, as required in Burt Pyramid algorithm, to construct the edge map. Therefore, the separation of the decimation element from the convolution element represents a principal improvement in diminishing the required processing time of the FSD technique of the Burt Pyramid algorithm.
In all stages of the FSD algorithm, the convolved sample stream is decimated to derive a second output sample stream that includes information-component samples corresponding to only a given sub-multiple of the certain samples that define the remnant sub-spectrum with a relatively lower sample density in each dimension than the particular relatively high sample density.
Operation of the FSD algorithm as illustrated in FIG. 2 results in the generation of a Laplacian pyramid. The Laplacian pyramid consists of band pass filtered (BPF) versions of the input image, with each stage of the pyramid constructed by the subtraction of two corresponding adjacent levels of the Gaussian pyramid. The Laplacian pyramid can also be viewed as a difference-of-Gaussians (DOG) pyramid, where the DOG kernel, which is a good approximation to the Laplacian operator, is convolved with the input at every sample location to produce corresponding edge maps.
It has been shown that the Laplacian pyramid forms a complete representation of the image for spatial frequencies ranging from 0 to a preselected maximum frequency of interest f.sub.0. Therefore, with the pyramid representation, complete reconstruction of the original image is enabled, for spatial frequencies up to f.sub.0.
In general, pyramidal filtering schemes, such as the Burt Pyramid algorithm and the FSD algorithm, exploit some of the perceptual considerations noted above to provide reasonably effective filtering for certain applications, particularly non-real time applications. However, pyramid algorithms, such as those described above, typically require a large amount of computations which limit the effectiveness for real-time applications, particularly those wherein a visual image changes with time, such as a television image. Some of these limitations are presently overcome by a pyramid chip available from David Sarnoff Laboratories.
7. Image Sharpening by Enhancing Existing High Frequencies
The prior art concentrates mostly on enhancing existing high spatial frequencies of a given input image. However, the addition of high frequencies to such images requires increased data handling for processing. Different enhancement schemes will result in images that are formally different from the original.
Enhancing existing high frequencies is performed by convolving the input image with masks, the masks having a basic high pass filter characteristic, or derivative function filter characteristic. Such a technique is high boost filtering, as described in Digital Image Processing by Rafael C. Gonzalez and Richard E. Woods, 1992, pp. 195-201, by Addison Wesley.
"Unsharp masking" (or high frequency emphasis method) is another general technique of sharpening an image by enhancing its existing high frequencies. Unsharp masking is implemented by creating a low pass filtered version of the input image and then subtracting it from the input image to create a high pass filtered version of the image. A fraction of this high pass filtered version is subsequently added to the image. Even though this approach yields reasonably good results in many cases, some undesired noise is generated in the dark regions of images, and often the enhanced images are not visually pleasing.
Subsequent techniques replace the high pass filter step with a non-linear filter, and repeat the technique of adding a version of the image to the original image. Examples of such techniques are suggested by Mitra, as explained in the next section.
8. Mitra Image Enhancement Techniques
An image enhancement scheme proposed by Mitra et al. (S. K. Mitra, H. Li, I. Lin and T. Yu, "A New Class of Nonlinear Filters for Image Enhancement," ICASSP 91, M5.1, pp. 2525-2528, 1991) can be seen in FIG. 3a. A filtered version of the input image is calculated and added back to the input image.
Filtering is performed in three stages. First, an adjustable DC bias and the input image are input in the input ports of adder 310. The output of the adder is connected to the input of the second nonlinear filtering stage 340.
The second nonlinear filtering stage 340 produces a result that is biased either in the vertical and horizontal directions, or along the diagonal directions-with the latter chosen as giving better performance. The output of the nonlinear filtering stage 340 is connected to the input of the third filtering stage 350.
The third filtering stage 350 adds a non-linearity via a multiplication of the highpass filter by the local mean. The third filtering stage 350 formally produces a mapping. The mapping function can be seen in FIG. 3b. Horizontal axis 352 signifies the level-value of the input pixel, and vertical axis 358 signifies the level-value of the respective output pixel. The mapping line 354 suggests what level-values of output pixels are returned for what level-values of input pixels.
The mapping line 354 has the effect of adding less of the high-frequency components to the dark regions and more to the brighter ones, and can be desirable for a smoother perception of the enhanced result.
The procedure thus outlined has the undesirable effect of shifting the phase (i.e., the Zero Crossing (ZC) of the second derivative) towards the brighter region, thereby causing edges to appear slightly shifted, resulting in reduced fidelity to the input image. Further, aliasing in the output image is introduced.
9. Related Art Summary
The foregoing summarized a number of prior art image processing techniques particularly adapted for enhancing or sharpening two dimensional visual images. Although the various techniques have proven to be reasonably effective for certain applications, there is room for improvement, particularly in the fidelity of the enhanced output images with respect to time varying input images. In particular, conventional pyramid filtering techniques such as the Burt pyramid algorithm and the FSD algorithm are too computationally intensive to be effective for real time applications, unless custom made pyramid chips are used. Furthermore, the conventional pyramid techniques do not allow for the addition of spatial frequencies higher than those contained in the image being processed. As such, the conventional pyramid techniques do not fully exploit certain visual perceptual considerations, such as the perception that an image with higher spatial frequencies is a more faithful representation of a true image, regardless of the actual fidelity of the image.
The Mitra technique is somewhat more effective for sharpening an image but does not provide a resulting image with fidelity to the edges of the input image, and introduces aliasing.
As can be appreciated, it would be desirable to provide an improved image filtering technique, which can be applied to sharpen images with fidelity to the edges and no aliasing, and ideally also in real time to sharpen time varying images.
Further, since image expansion results in blurring, it would be desirable to provide an improved image filtering technique to sharpen expanded images.

Image enhancement by non-linear extrapolation in frequency space