The present invention relates to the production of adenosine deaminase (ADA) deficient mice and the use of such mice as an animal model for dysfunctions associated with elevated adenosine levels. Also, provided by the present invention are methods of treating dysfunctions associated with elevated adenosine levels and methods of screening compounds for pharmaceutical activity in the treatment of dysfunctions associated with elevated adenosine levels.

1.1 Field of the Invention
The present invention provides adenosine deaminase (ADA) deficient mice. Also provided are methods of using the mice as an animal models for the analysis of physiological states that are sensative to disturbances in adenine nucleoside metabolism.
1.2 Description of Related Art
1.2.1 Adenosine Deaminase Deficiency
Genetic defects in purine metabolism in humans result in serious metabolic disorders, often with pronounced tissue-specific phenotypes (Blaese, 1995a). A striking example of this is adenosine deaminase (ADA) deficiency, which results in impaired lymphoid development and a severe combined immunodeficiency disease (SCID) (Hershfield and Mitchell, 1995).
ADA deficient SCID was the first of the inherited immunodeficiencies for which the underlying molecular defect was identified (Giblett et al., 1972); however, despite over 20 years of subsequent research, a satisfactory explanation for the lymphoid specificity of this metabolic disease has not emerged. This is largely due to the inaccessibility of human tissue for detailed phenotypic and metabolic analysis and the absence of an animal model which retains features of ADA deficiency in humans.
Additional interest in ADA deficiency stems from recent attempts to use novel therapeutic strategies, including enzyme therapy (Hershfield et al., 1993) and gene therapy (Bordingon et al., 1995; Blaese et al., 1995), to treat the condition in humans. Although the results of these therapeutic approaches are encouraging, unexpected outcomes have raised numerous important questions regarding the efficacy of specific treatment protocols (Hershfield et al., 1993; Blaese, 1995b). The pace with which new enzyme and gene therapy protocols can be tested would be greatly increased by the availability of an animal model for ADA deficiency.
The availability of a genetic animal model for ADA deficiency would make possible a wide range of biochemical and immunological experiments that are not permissible with humans.
Attempts to generate ADA deficient mice were initially reported by two groups (Wakamiya et al., 1995; Migchielsen et al., 1995), resulting in animals with independent sites of Ada gene disruption. However, these attempts did not lead to the production of viable ADA deficient mice. In each case a similar phenotype was observed. ADA deficient fetuses died perinatally due to severe liver damage (Wakamiya et al., 1995; Migchielsen et al., 1995). This phenotype was accompanied by profound disturbances in purine metabolism, including marked increases in the ADA substrates adenosine and 2'-deoxyadenosine.
2'-Deoxyadenosine is a cytotoxic metabolite that can kill cells through mechanisms that include disturbances in deoxynucleotide metabolism (Ullmann et al., 1978; Cohen et al., 1978) and the inhibition of cellular transmethylation reactions (Hershfield, 1979; Hershfield et al., 1979). ADA deficient fetuses exhibited evidence for both of these mechanisms of 2'-deoxyadenosine cytotoxicity, in that levels of the 2'-deoxyadenosine metabolite, dATP, were markedly elevated, and the enzyme S-adenosylhomocysteine (AdoHcy) hydrolase was inhibited (Wakamiya et al., 1995; Migchielsen et al., 1995). These metabolic disturbances are thought to contribute to the liver damage and subsequent death of ADA deficient fetuses.
Previous attempts by the inventors to produce mice that expressed ADA in the fetus but not in the neonatal mouse had failed (Blackburn et al., 1995). The strategy was to introduce an ADA transgene that would only be expressed in the placenta into heterozygous ADA knockout mice. The heterozygous transgenic mice could then be mated to yield homozygous ADA knockout mice that were able to develop because of the transgene provided ADA expression in the placenta. Viable mice were obtained by this strategy; however, the promoter used to express the transgene was not specific to the placenta and ADA expression was detected in the gastrointestinal tract of these animals, predominantly in the forestomach. Therefore, although ADA was not expressed in the lungs of these animals, ADA expression was present in the gut.
Disclosed herein is description of a mouse lacking post-partum ADA expression. This was acheived by creating a placenta specific promoter (Shi et al., 1997) and using this promoter in a transgene construct to express ADA. Indeed, the ADA deficient mice have immunodeficiencies similar to that of humans with ADA deficiency (Blackburn, 1998). Surprisingly and unexpectedly, the ADA deficient mice showed lung abnormalities. Upon extensive examination, the inventors were able to determine that the lung abnormalities in ADA deficient mice were reminiscent of those seen in asthma.
1.2.2 Asthma
Asthma is an inflammatory disease of the airways. In the U.S., 13% of children and 6% of adults suffer from asthma and 1% of health care cost are devoted to asthma treatment (Vogel 1997, Cochrane et al., 1996; Weiss et al., 1992). The disease is typified by the infiltration and activation of immune cells in the lung, followed by airway inflammation and obstruction (Vogel 1997). Many factors can trigger asthma, however, the mechanisms by which these triggers lead to airway inflammation and damage are not well understood. There is increasing evidence that asthma has its roots in early life (Barker 1992; Busse et al., 1995), but the mechanisms involved are not understood. Nor is it known how genetic and environmental influences interact to manifest asthma. Therefore, there is a need in the art for a model system with a predetermined genetic background that would allow testing of the influence of environmental factor on asthma development.
1.2.3 Animal Models and Asthma
Because of the limitations on the availability of human tissues, a number of animal models have been developed to better define the structural and functional consequences produced by environmental agents within the respiratory tract (Larsen and Colasurdo, 1997; Abraham and Baugh, 1995). While an ideal animal model should exhibit all the features of human asthma, there is general agreement that a single animal model does not exhibit all the functional and biological changes that would mimic the disease process seen in humans (Larsen and Colasurdo, 1997).
1.2.4 Adenosine Signaling in Asthma
Adenosine is a regulatory nucleoside that has the potential to be produced from all cells as a product of ATP catabolism (Arch and Newsholme, 1978). In mammalian tissues there exist two metabolic pathways through which adenosine can be generated: One is through the enzyme 5'-nucleotidase, which generates adenosine by enzymatic dephosphorylation of 5'-AMP (Zimmerman 1992). The other involves the hydrolysis of S-adenosylhomocysteine to adenosine and homocysteine (Schutz et al., 1981). Once generated, adenosine is freely transported in and out of cells through an ubiquitous nucleoside transporter (Arch and Newsholme, 1978) and serves as an extracellular signal. Inside the cell it is either deaminated to inosine by ADA (Blackburn and Kellems 1996) or is phosphorylated to AMP by adenosine kinase (Arch and Newsholme, 1978). Extracellular adenosine can bind to cell surface receptors to elicit a wide variety of cellular responses (Stiles 1992).
The regulatory actions of adenosine are mediated by several distinct membrane receptors that are classified as P1 purinergic receptors (Olah and Stiles 1995). Distinct subtypes of adenosine receptors have been identified on the basis of cDNA sequence and pharmacological profiles and are termed A1, A2a, A2b, and A3 adenosine receptors (Libert et al., 1989; Stehle et al., 1992; Pierce et al., 1992; Rivkees and Reppert, 1992; Fink et al., 1992; Zhou et a., 1992; Salvatore et al., 1993). Adenosine receptors are tightly coupled to effector enzymes by guanine nucleotide (G-protein) regulatory proteins (Stiles 1992; Olah and Stiles 1995), and each receptor subtype has a distinct affinity for adenosine and its structural congeners. Both A2 receptor subtypes couple to adenylate cyclase by stimulatory Gs-proteins and subsequently raise intracellular cAMP levels; in contrast, A1 and A3 receptors couple to inhibitory Gi-proteins and have the opposite effect (Olah and Stiles 1995). A1 and A3 receptors have also been shown to mediate the activation of potassium channels, inactivate calcium channels, stimulate or inhibit phosphatidylinositol turnover, inactivate phospholipase A2 or C, and inhibit chloride transport (Linden, 1991; Olah and Stiles 1995). Thus, adenosine signaling can have input into multiple intracellular signal transduction pathways. There is evidence that all four of these receptors are expressed in lung tissue and inflammatory cells and have all been implicated in participating in asthma (Dixon et al., 1996; Marquart 1997; Marquart et al., 1994).
Adenosine has been recognized as a potential signaling molecule in asthma (Holgate et al., 1992; Marquart 1997). Theophyline, an adenosine receptor antagonist, has been used in the treatment of asthma for decades (Barnes 1997). Adenosine is produced in response to tissue damage such as hypoxia (Arch and Newsholme, 1978) and has been shown to be released from hypoxic lung tissue (Mentzer et al., 1975), and to be elevated in bronchoalveolar lavage fluid (Driver et al., 1993) and blood (Mann et al., 1986) from asthma patients. Adenosine receptor expression increases in lung tissues from asthma patients (Richardson, 1997), and asthmatics are much more sensitive to exposure to adenosine than non-asthmatics (Cushley et al., 1983).
In vitro studies have shown that adenosine can enhance mediator release from human lung mast cells (Marquart et al., 1978), and adenosine itself can be released from stimulated mast cells (Marquart et al., 1984). Mast cell degranulation has been attributed to the A3 receptor (Reeves et al., 1997) and the A2b receptor has been implicated in IL-8 secretion from mast cells (Feoktistov and Biaggioni 1995). Adenosine also modulates pro-inflammatory events in eosinophils (Kohno et al., 1996; Walker 1996) and promotes macrophage differentiation (Najar et al. 1990). In addition, asthma induced in a rabbit model was prevented by preexposing the lungs to antisense oligonucleotides directed at blocking expression of the A1 receptor (Nyce and Metzer 1997).
Many of the known methods of treating asthma that are adenosine related focus on disrupting adenosine signalling through the receptors of the lung tissue. However, the present invention is the first to focus on lowering adenosine levels in an animal as a treatment for asthma. Surprisingly, the inventors were able to demonstrate that reduction of systemic adenosine levels alleviates asthma.
1.2.5 Adenosine and Deoxyadenosine Signaling in Severe Combined Immunodeficiency
ADA deficiency in humans is most often associated with a severe combined immunodeficiency (SCID) that is thought to arise from perturbations in signaling processes that result from the accumulation of the ADA substrates adenosine and deoxyadenosine (Hershfield and Mitchell, 1995). The exact mechanism through which accumulations in adenosine and/or deoxyadenosine lead to SCID are not know. Since the thymus and spleen, major immune organs, exhibit expression of adenosine receptors (Dixon et al., 1996), it is likely that adenosine signaling may be involved. Deoxyadenosine does not bind extracellular receptors, but has potent cytotoxic effects that are mediated through various intracellular pathways (Hershfield and Mitchell, 1995). Both adenosine and deoxyadenosine levels are elevated in the immune organs of the ADA deficient mice that are the topic of this invention 0Blackburn et al., 1998). In addition, these animals suffer from a combined immunodeficiency similar to that seen in ADA deficient humans. It is therefore likely that ADA deficient animals will serve as excellent models for determining how adenosine and deoxyadenosine signaling contribute to SCIDS, as well as serve as models for developing and testing therapies for the treatment of this disease, including enzyme therapy and gene therapy.
1.2.6 Adenosine Signaling in Other Physiological Systems
By generating animals that lack ADA, the enzyme responsible for controlling adenosine levels in tissues and cells, the inventors have created animals that exhibit systemic elevations in adenosine levels. It is therefore likely that these mice will prove useful in assessing the role of adenosine signaling in some if not all of these physiological systems. These systems include cardiovascular and vascular, neurologic, immunologic, renal, gastrointestinal, vascular, skeletal, and reproductive systems.

Adenosine deaminase deficient transgenic mice and methods for the use thereof

Board of Regents, The University of Texas System


A class of Glycine B partial agonists is described for use for treatment of psychosis. Preferred Glycine B partial agonists include amino-isoxazolidone compounds such as D-cycloserine and its prodrugs.

There are many psychotic states for which therapeutic treatments are under investigation. Drugs which are currently available on the market are thought to act as antagonists at the dopaminergic receptors located in the Central Nervous System (CNS), examples of such drugs being haloperidol and chlorpromazine. These drugs typically induce long lasting and sometimes irreversible side-effects, such as tardive dyskinesia. Thus, the search for improvements in therapy for psychotic disorders has been directed to use of drugs with a different mode of action.
Phencyclidine [1-(-phenylcyclohexyl)piperidine; PCP] is a known general anesthetic and is in use as an animal tranquilizer. PCP is a potent psychotomimetic agent used frequently as a "street" drug. Widespread abuse of PCP has led to increased incidence of PCP-induced psychoses [C. V. Showalter et al, Amer. J Psychiat., 134, 1234 (1977)]. PCP abusers experience an apparent sensory isolation accompanied by a feeling of depersonalization which can be terrifying to the person. These subjective changes make PCP an appropriate drug model for study of schizophrenia. The most impressive evidence that PCP psychosis resembles schizophrenia is the fact that drug users have been mistaken by experienced psychiatrists for schizophrenics before obtaining the history of drug use [S. H. Snyder, Nature, 285, 355-356 (1980)].
PCP has been reported to modulate allosterically the NMDA receptor [P. Loo et al, Eur. J. Pharmacol., 123, 467-468 (1986)] and it has been speculated that the psychotomimetic activity of PCP is related to its antagonism of NMDA transmission [C. A. Tamminga et al, Synapse, 1, 497-504 (1987)]. Facilitation of NMDA transmission by action at the glycine modulatory site may antagonize the effect of an endogenous PCP-like ligand [R. Quirion et al, Peptides, 5, 967-973 (1984)].
Amino-oxazolidone compounds have been investigated for CNS effects. For example, the compound D-cycloserine, in its D- and L-isomer forms, has been evaluated for CNS effects in animals [O. Mayer et al, Arzneim. Forsch., 21(2), 298-303 (1971)]. These cycloserine isomers have also been evaluated for psychological and physiological effects in human subjects. For example, D-cycloserine when administered at 500 mg/day doses to healthy human subjects, appeared to stimulate slight sociability, but with depressed mental alertness [M. Vojtechovsky, Act. Nerv. Super., 7(3), 269 (1965)]. Also, D-cyloserine has been administered at 1000 to 1500 mg/day to healthy volunteers whose blood levels showed increased levels of monoamine oxidase enzyme activity [V. Vitek et al, Psychopharmacologia, 7(3), 203-219 (1965)].
D-cycloserine has been investigated as a therapeutic agent for mental disorders in clinical trials, wherein D-cycloserine was administered to mentally disturbed patients at doses of 500 mg. per day [G. E. Crane, Compr. Psychiat., 2, 51-53 (1961)]. In such clinical trials, improvements in depression, insomnia, anexoria or tension were found for some patients, while patients suffering from severe neurosis or psychosis responded poorly to such medication. Moreover, D-cycloserine has been used to exacerbate the symptoms of schizophrenia in an attempt to cure the ailment by symptom provocation [J. Simeon et al, Compr. Psychiat., 11, 80-88, (1970)].
It appears that D-cycloserine, at the dose levels used in these studies, is acting as an antagonist at the glycine site of the NMDA-PCP receptor complex mimicking the action of PCP by inducing psychosis.

Use of a Glycine B partial agonist as an antipsychotic


A solid correction material for covering writing or drawing errors on paper is disclosed. The correction material may be formed into a stick and housed in hollow body and is composed of: (a) 5-40 wt % of a thermoplastic synthetic resin, preferably a homo- or copolymer based on (meth)acrylic compounds; (b) 10-70 wt % of a pigment, preferably a titanium dioxide pigment; (c) 5-20 wt % of a mono- or polyvalent alcohol, preferably glycerin being preferred; (d) 5-30 wt % of carrier mixture composed of (i) a fatty acid with 12 to 32 carbon atoms or a salt of a fatty acid, with stearate being preferred, and (ii) at least one member selected from the group consisting of a polyolefin and an ester wax, possibly 5 to 15 wt % water; and (e) 0 to 10 wt % of conventional additives, such as defoaming agents, dyes, aroma substances, and preservatives. The correction material is solid at room temperature and has a viscosity between about 100 and about 150 cPa.s at 90.degree. C.

Writing errors on paper are conventionally corrected by covering the error with liquid correction agent containing a covering white pigment using an application means such as a brush, sponge, or brush flocked with a fuzzy covering. The liquid correction agent and application means are usually offered as a packaged unit. The liquid correction agent, however, typically forms a drop on the underside of the application means. Consequently, this drop of liquid correction agent is uncontrollably transferred to the paper and forms ugly "correction bumps" that are slow drying and difficult to overwrite. To overcome this problem, excess liquid correction agent is usually wiped away from the application means at the edge of a container opening. The wiped away liquid correction agent, however, quickly hardens at the edge of the container such that when the application means is subsequently wiped off, lumps of pigment or thickened liquid correction agent are transferred to the application means. The lumps of pigment or thickened liquid correction agent cause the liquid correction agent to be non-uniformly applied to the paper.
Prior liquid correction agents usually contain environmentally hazardous solvents and suspension agents. Solid components in liquid correction agents, however, tend to precipitate out of solution, which concomitantly shortens the shelf life of conventional liquid correction agents. Further, conventionally used solvents often dissolve ink or toner dyes in the area to be corrected either causing the dyes to color or smear the correction agent. As a result, clean covering of writing errors is virtually impossible. In addition, so-called reactive papers, such as NCR and thermosensitive papers, have an oily dye-developing layer that can be activated by solvents found in conventional liquid correction agents.
One replacement for liquid correction agents is a correction stick made of a solid correction material containing a covering pigment that is rubbed off on the correction area. Problems with prior correction sticks include poor adhesion to paper (JPLO 51-106523; JP 89-298704) or non-uniform application. JP 63-199777 discloses a correction material composed mainly of a white pigment, a waxy carrier, and a binder made of an ethylene-vinyl acetate-copolymer that rubs off and adheres to the paper. The disclosed correction material, however, ages quickly and after a short time, cannot be uniformly applied because ink flow or abrasion is adversely affected. As a result, the surface of the applied correction material is non-uniform and difficult to overwrite.


A urinal device is disclosed for the reception therein of a user's penis. The device includes a support worn by the user for supporting the device relative to the user. A collar is secured to the support for the reception therein of the user's penis. The arrangement is such that in use of the device, the user's penis is inserted through the collar. The collar has a first and a second end. A flexible tubular portion is provided for sealing the device relative to the user's penis, the tubular portion having a first and second extremity. The first extremity engages the first end of the collar and the second extremity sealingly cooperates with the user's penis. A collection device sealingly cooperates with the second end of the collar, the arrangement being such that in use of the device, the user's penis is sealingly supported by the tubular portion so that the user's penis is disposed within the collar.

Many devices have been manufactured for use by a patient suffering from incontinence. Most of the aforementioned devices include a collection bag for collecting the patient's urine and means for connecting the bag to the body of the user.
In the case of male patients, the prior art urinal devices usually include a connector arrangement through which the user's penis is inserted and a flexible collar which is intended to seal against the user's penis in order to inhibit leakage of urine therepast.
However, the aforementioned prior art devices do not consistently provide a waterproof seal. Furthermore, a patient having undergone surgery and suffering from the condition of retracting penis is presented with a serious problem with regard to sealing the unit against leakage.
More particularly, external urinal devices of the aforementioned type have been especially recommended for patients suffering from occasional or complete urinary incontinence. However, in operation such devices have not always been entirely satisfactory.
On the other hand, the device according to the present invention offers comfortable freedom of movement for the user without any embarrassment that would be occasioned by leakage from the unit.
The device according to the present invention is particularly useful for men suffering from the medical condition known as "retracting penis". The aforementioned prior art units have been inadequate in overcoming the problem of sealing and securing such device to the user thereof without subsequent leakage.
Additionally, the prior art arrangements suffer from the drawback of causing irritation to the skin. Also, such prior devices have caused a restriction of movement of the user.
The device according to the present invention is easily fitted to a male patient including those suffering from the condition known as retracting penis.
The device according to the present invention has a distinct advantage over the prior art arrangements in that such prior art devices require special clamps and the like in order to provide adequate sealing.
The device according to the present invention includes a collection device which is either directly connected to a collar or alternatively is connected to the collar by means of latex tubing. An adapter connects the tubing to a leg bag or the like depending on the level of the patient's incontinence.
The device according to the present invention includes a latex sheath which may be hygienically cleaned with soap and water.
Ideally, the patient would be provided with two units, one unit would be worn by the patient while the other unit is being washed and dried.
Therefore, it is a primary objective of the present invention to provide a urinary device that overcomes the aforementioned inadequacies of the prior art devices and which makes a considerable contribution to the medical art.
Other objects and advantages of the present invention will be readily apparent to those skilled in the art by reference to the detailed description contained hereinafter taken in conjunction with the annexed drawings.


A microscope objective comprising a first, second, third fourth and fifth lenses, in which the first lens is a positive lens, the second lens is a positive meniscus lens, the third lens is a negative lens, the fourth lens is a positive meniscus lens and the fifth lens is a positive lens, and satisfying the following conditions for which the number of lenses constituting the lens system is small, working distance is large and resolving power is extremely high.. (1) 0.14f<d3<05f PA1 (2) PA1 (3) 0.5<r.sub.4 /r.sub.3 <2.7 PA1 (4) 0.4d.sub.4 <d.sub.5 /n.sub.3 +d.sub.6 +d.sub.7 /n.sub.4 <2.5d.sub.4 PA1 (5) .nu..sub.3 <35, .nu..sub.1 >50, n.sub.1 >1.60. 0.28f<.vertline.r.sub.2 .vertline.<0.69f PA2 0.28f<.vertline.r.sub.8 .vertline.<0.69f

(a) Field of the Invention
The present invention relates to a microscope objective and, more particularly, to a microscope objective with low magnification.
(b) Description of the Prior Art
Known microscope objectives with low magnification have disadvantages that the number of lenses constituting the lens system becomes large and the working distance becomes short when it is attempted to obtain favourable flatness of image. Besides, for known microscope objectives, it is impossible to obtain really satisfactory resolving power. It is considered that the cause of unsatisfactory resolving power is that especially spherical aberration becomes large in the intermediate field angle.


Provided is an illuminating device that includes: first light guiding means (3) where light incident from one end surface is propagated inside to exit from the other end surface; illuminating optical system (1) that spatially separates a luminous flux from the other end surface of first light guiding means (3) into a plurality of luminous fluxes, and forms an optical image formed on the other end surface of first light guiding means (3) on display element (12); reflective polarizing plate (11) that is located between illuminating optical system (1) and display element (12), and transmits first polarized light while reflecting second polarized light different that is in polarized state from the first polarized light toward illuminating optical system (1); reflecting element (7) that is disposed at a position where the plurality of luminous fluxes are spatially separated, and that includes transmission regions through which the plurality of luminous fluxes are transmitted, and a reflecting film formed in a region other than the transmission regions to reflect light reflected by reflective polarizing plate (11) toward reflective polarizing plate (11); and phase plate (10) located between reflecting element (7) and reflective polarizing plate (11).

Patent Literatures 1 and 2 discuss a projector that uses a LED (Light Emitting Diode) as a light source for illuminating a DMD (Digital Micromirror Device) serving as a display element (Patent Literatures 1 and 2). The projector of this type is expected to reduce costs more than a projector that uses a white discharge lamp, and achieve performance including miniaturization, lower power consumption, and a wider color reproduction range.
There are also a projector that uses a single LCoS (Liquid Crystal on Silicon) element (Nonpatent Literature 1), and a projector that users three liquid crystal panels as display elements (Nonpatent Literatures 2 and 3).
In the liquid crystal projector, usually, a liquid crystal panel must be illuminated with polarized light. Generally, light from the LED is unpolarized light. Thus, when the LED is used as a light source for illuminating the liquid crystal panel, it is preferable that the light from the LED be converted into polarized light to increase light use efficiency.
For example, when a display panel is a TN liquid crystal (Twisted Nematic Liquid Crystal) panel, with respect to the unpolarized light from the LED which includes two linear polarized components which are orthogonal each other, one of linear polarized component is converted to be similar to the other polarized component. When efficiency of this polarizing conversion is low, the light use efficiency declines. When no polarizing conversion is carried out, about a half of the light is not used as illumination light.
In the projector described in Nonpatient Literature 1, a luminous flux from the LED that is the light source is roughly converted into parallel luminous fluxes by a light guiding member having a composite paraboloidal surface shape, which is referred to as a CPC reflector. The display panel is illuminated with the parallel luminous fluxes from the light guiding member.
A ¼ wavelength plate and a reflective polarizing plate are located in a traveling direction of the luminous flux from the light guiding member. For example, the polarizing plate transmits p-polarized light while reflecting s-polarized light. The s-polarized light reflected by the polarizing plate passes through the ¼ wavelength plate. The light (circular polarized light) passed through the ¼ wavelength plate returns to the LED to be reflected on a surface of the LED. The light reflected on the surface of the LED is converted parallel by the light guiding member, and then passes through the ¼ wavelength plate again.
A portion of the s-polarized light reflected by the polarizing plate, which has passed through the ¼ wavelength plate twice in the returning process to the LED and in the process of being reflected on the surface of the LED to travel toward the polarizing plate, is converted into p-polarized light.
In addition, there is an illuminating device discussed in Patent Literature 3. This illuminating device includes: a light source; a glass rod one end surface of which light from the light source enters; condensing means for condensing a luminous flux that has exited from the other end surface of the glass rod; and a PBS (Polarizing Beam Splitter) polarizing conversion array disposed at a position where the condensing means forms a plurality of light source images.
The PBS polarizing conversion array is formed by alternately arranging a first prism that includes a polarizing separation film formed to transmit the p-polarized light while reflecting the s-polarized light and a second prism that includes a reflecting film formed to reflect the light reflected by the polarizing separation film of the first prism in a traveling direction of the p-polarized light transmitted by the polarizing separation film. A ½ wavelength plate for converting the s-polarized light into p-polarized light is formed in an exit surface of the second prism. A light shielding plate is formed in a surface opposite the exit surface of the second prism. The condensing means is configured to form a light source image on an incident surface of the first prism.

Illuminating device and projection display device using the same


A chip card includes a body of electrically insulating layers, one of which carries an open loop antenna having two ends. The body is equipped with a cavity for housing a micromodule adapted for connection to the antenna by two terminals. The micromodule includes an insulating substrate carrying, on a first side, a semiconductor component, and on a second side, several electrical contact pads. Two of the contact pads are disposed in a strip running through a center region of the substrate. The terminals are connected to the two contact pads through the substrate, and the two pads are respectively connected to ends of the antenna.

The present invention relates to a chip card equipped with an open loop antenna, particularly a chip card of the so-called xe2x80x9cmixed connectionxe2x80x9d type, which will be defined below.
Within the framework of the invention, the term xe2x80x9ccardxe2x80x9d should be understood in its most general sense: smart card, xe2x80x9cchipxe2x80x9d Integrated Circuit (I.C.) card, card, etc.
In terms of the mode of communication with the outside world, there are two main categories of chip cards: chip cards with chip cards and contacts without contacts. In the second case, various methods can be used to establish communication between the card and the outside world. It is possible to use, in particular an optical coupling or an electromagnetic coupling by means of a spiral loop antenna. The invention relates to the second type of coupling.
The majority of chip cards are of the first type, i.e., contact cards. These chip cards are made from xe2x80x9cmicromodules,xe2x80x9d i.e. packages comprising a printed circuit or a metal grid having contacts to which integrated circuit componentsxe2x80x94memories, microprocessors, microcontrollers, etc.xe2x80x94are bonded and wired. These components are then protected by a coating resin in order to make the micromodules usable for the final mounting operation. The latter consists of bonding the micromodules into a plastic support comprising a cavity designed to receive this micromodule.
Cards of the second type, called xe2x80x9ccontactlessxe2x80x9d cards, are coupled with the outside environment by electromagnetic induction. The frequencies used are divided into two ranges: a low frequency range, the nominal frequency typically being 125 kHz, and a high frequency range, the nominal frequency typically being 13.56 MHz. For this purpose, an antenna is provided, which normally exists in the form of a spiral loop, connected by its ends to the aforementioned micromodule. In order to obtain adequate sensitivity, it is necessary to provide an antenna comprising about a hundred coils if working at low frequency and 2 to 3 coils if working at high frequency.
The current technologies used for the production of chip cards make it possible to integrate the aforementioned antennas into the material of the chip card, more precisely between two layers of plastic material. The coils are actually disposed on layers of plastic material of the xe2x80x9cPVCxe2x80x9d or xe2x80x9cPETxe2x80x9d type. The metal layers can be printed on the plastic (for example by serigraphy) or produced by depositing a metal lead, produced directly by thermal soldering on the plastic layer.
Finally, there are so-called xe2x80x9cmixedxe2x80x9d chip cards, which constitute the preferred field of application of the invention. This type of chip card has the advantage of allowing access both via xe2x80x9cconventionalxe2x80x9d contacts, which makes it possible to use them in standard readers, or by passing in proximity to suitable transmitting-receiving devices, the micromodules comprising a high-frequency interface. The term xe2x80x9creaderxe2x80x9d should be understood in a general sense, i.e. a device that allows the reading and/or writing of digital information in a chip card.
In the following, we will consider this preferred application, i.e. the case of xe2x80x9cmixedxe2x80x9d chip card.
Generally, chip cards are standardized and comply with certain standards, from both an electrical and a mechanical point of view, particularly the following standards:
ISO 7816 for contact chip cards
ISO 14443 for contactless proximity chip cards.
In the latter case, the frequency used is generally equal to 13.56 MHz, which reduces the size of the antenna, the latter comprising only two or three coils.
The availability of components for xe2x80x9cmixedxe2x80x9d chip cards has lead to the design of novel assembly processes. Keeping in mind that this type of component is mass produced, it is necessary for the final cost price to be as low as possible. Moreover, it is also necessary to obtain high reliability, as in the case of a conventional contact chip card.
For all these reasons, it is desirable to continue to use, insofar as possible, assembly processes and technologies of the prior art that have been tried and tested. Among these processes are the following, to give a non-exhaustive list:
the mounting of the semiconductor micromodule onto a substrate of the printed circuit type, equipped with galvanic contact pads;
the production of the plastic support of the chip card itself, by pressing a stack of layers of plastic material; and
the mounting by bonding of the micromodule into a cavity of the plastic support.
It is still necessary, however, to connect the semiconductor component or xe2x80x9cchipxe2x80x9d to the antenna, and more precisely to the ends of the antenna, which poses a specific problem. The connection is produced via connection pads that must be connected to the aforementioned ends.
In the prior art, it has been suggested that this connection be produced by means of a printed circuit that is two-sided, i.e. comprising metal tracks, for example made of copper, on both sides of an insulating substrate. The substrate in this case is a two-sided printed circuit. The solution has the drawback of a high cost. Because of this, it does not meet at least one of the requirements mentioned.
Furthermore, even if a high frequency is used (typically 13.56 MHz), the antenna is constituted by an open loop, generally comprising at least two or three coils. Therefore, at one point or another on the surface of the chip card, there is necessarily a crossing of two conductive tracks, directly over one another. It follows that it is necessary to provide an insulating area and a conductive xe2x80x9cbridgexe2x80x9d between two antenna sections.
The main object of the invention is to provide an optimized connection that makes it possible to connect the conductive pins of the micromodule of the chip card to the ends of the antenna. It makes it possible, in particular, to minimize the number of metal layers, either at the micromodule level or at the antenna level. It is preferably applied to chip cards of the xe2x80x9cmixedxe2x80x9d type.
For this reason, according to an essential characteristic of the invention, the active side of the substrate carrying the integrated semiconductor component, i.e. the contact pad side, is used to establish electrical connections between input/outputs of the component and coupling antenna terminations.
In a second embodiment, contact pads on the active side of the substrate are also used to establish electrical connections between antenna sections.
The subject of the invention is a chip card comprising a basic body of electrically insulating layers, the card carrying on one of its layers an open loop antenna having two ends, said body being equipped with a cavity housing a micromodule designed to be connected to said open loop antenna by two terminals, said micromodule comprising an electrically insulating substrate carrying, on a first side, a semiconductor component, and on a second side, several electrical contact pads, characterized in that two contact pads are disposed in a strip running through a center region of the substrate, said terminals respectively being connected to said two contact pads through said substrate, the two contact pads respectively being connected to the two ends of the antenna.
The invention also relates to a micromodule designed to be connected by two terminals to an open loop antenna outside the micromodule and having two ends, said micromodule comprising an electrically insulating substrate carrying, on a first side, a semiconductor component, and on a second side, several electrical contact pads, characterized in that two contact pads are disposed in a strip running through a center region of the substrate, said terminals respectively being connected to said two contact pads through said substrate, the two contact pads being designed to be respectively connected to the two ends of the antenna.
Finally, the invention relates to a method for producing a chip card comprising an antenna having two ends, from at least two layers of electrically insulating material, and from a micromodule comprising an electrically insulating substrate carrying, in a center region and on a first side, a semiconductor component, and in a peripheral region and on the first side or a second side, two contact pads connected to two antenna input/output terminals of the semiconductor component, the contact pads being disposed in such a way that once the micromodule is applied to the card, the two contact pads face said ends of the antenna, comprising the following steps:
preparing a first layer carrying said antenna on one side;
preparing a second layer having two through-holes disposed so that once the second layer is applied to the side of the first layer carrying the antenna, said holes face said ends of the antenna;
applying and attaching the second layer to the side of the first layer carrying the antenna;
applying the micromodule to the card so that its semiconductor component is housed in a center well formed in the card, and so that its peripheral region is housed in a peripheral well disposed around the center well;
connecting the contact pads of the micromodule and the ends of the antenna to one another.

Chip card equipped with a loop antenna, and associated micromodule


An apparatus for controlling hydraulically actuatable components of a blowout preventer stack assembly and a system for same. The apparatus comprises a blowout preventer stack including hydraulically actuatable components and a lower marine riser package coupled to the blowout preventer stack and including additional hydraulic components. The lower marine riser package includes a solenoid valve configured to control at least some of the components. The solenoid valve receives hydraulic fluid from a dedicated accumulator or accumulator bank configured to supply hydraulic fluid exclusively for use with the solenoid valve. A closed-loop hydraulic circuit is formed between the accumulator or accumulator bank and the solenoid valve.

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the presently described embodiments. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present embodiments. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
In order to meet consumer and industrial demand for natural resources, companies often invest significant amounts of time and money in finding and extracting oil, natural gas, and other subterranean resources from the earth. Particularly, once a desired subterranean resource such as oil or natural gas is discovered, drilling and production systems are often employed to access and extract the resource. These systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems generally include a wellhead assembly through which the resource is accessed or extracted. These wellhead assemblies may include a wide variety of components, such as various casings, valves, fluid conduits, and the like, that control drilling or extraction operations. Subsea wellhead assemblies typically include control pods that operate hydraulic components and manage flow through the assemblies.
This invention relates to a closed-loop solenoid pressure supply system for operating subsea hydraulically-actuatable devices such as valves, blowout preventers and hydraulically actuated wellhead connectors. Such devices require pressurized hydraulic fluid, typically operated up to 5,000 psi, for their operation. The disclosed closed-loop solenoid pressure supply system is used in the control of the flow of such pressurized hydraulic fluid.
Subsea hydraulic control systems typically consist of a group of hydraulic fluid accumulators, a control unit for operating solenoid valves which control hydraulic fluid supply, and high pressure lines or hoses which carry the hydraulic control fluid from the accumulator bottles to the control unit and on to the component to be operated, e.g., valve, blowout preventer, wellhead connector, and the like. Pressurized hydraulic control fluid is stored in the accumulator bottles at a desired operating pressure, e.g., 1500, 3000 psi, 4,500 psi. This hydraulic fluid is used throughout the subsea system. Typically, hydraulic fluid used in a control system is a mixture of mostly water and a concentrate fluid that provides lubricity and corrosion protection for proper operation of the valves in the system. Frequently, the control fluid is not properly maintained and will become contaminated due to bacteria growing in the system or lack of maintenance. It is widely accepted in the industry that fluid contamination is a wide spread problem that can lead to considerable non-productive time and, accordingly, lost revenue.
Solenoid valves disposed in the control pod are particularly susceptible to hydraulic fluid contamination. Because existing subsea systems use the same hydraulic fluid throughout the system, contamination of the hydraulic fluid exposes all components, including solenoid valves, to the contamination. Accordingly, it is desirable to have a control system with reduced contamination of solenoid valves disposed therein. The present invention relates to a closed-loop solenoid valve pressure supply system, wherein the solenoid valves have their own dedicated hydraulic fluid supply separate from the hydraulic fluid used for the rest of the system, i.e., the main hydraulic fluid supply. Because the solenoid valves have their own dedicated fluid supply in a closed-loop system, the fluid can be a high quality fluid that will not degrade over time and can be filtered to a high degree to protect the solenoid valves. By reducing contamination and increasing fluid quality, the life of each solenoid valve can be greatly extended.
The illustrated figures are only exemplary and are not intended to assert or imply any limitation with regard to the environment, architecture, design, or process in which different embodiments may be implemented.


A circuit (290) comprises an RC filter circuit (100), which comprises an ohmic resistor (112) and a capacitor (113). In addition, the circuit (290) comprises a compensation circuit (200), which is designed to provide a compensation current flow (192), which corresponds to a current flow (191) to a load (150).

RC filters are known which have a frequency-dependent filter curve. Such RC filters typically comprise an ohmic resistor and a capacitor. By suitable dimensioning of a resistance of the ohmic resistor and/or a capacitance of the capacitor, specific filter characteristics, such as in particular a specific filter curve, can be achieved. For example, a 3 dB point can be fixed.
However, such RC filters can have limitations. It may thus be possible, for example, for a finite input resistance of a load which is coupled to the RC filter as downstream stage to change the filter characteristics. Thus, in this scenario, a finite current can flow through the ohmic resistor of the RC filter in the case of a finite input resistance, which in turn causes a voltage drop across the resistor. Thus, a changed voltage drop can form across the capacitor, for example, as a result of which the filter characteristics can be changed. For example, in particular tolerances or drifts in the input resistance can have an influence on the filter characteristics in this way. The ohmic resistor can heat up.
Technologies are known for reducing such an influence of the downstream load on the RC filter. Firstly, it may be possible to use a resistor with comparatively small dimensions. In this case, the voltage which forms as a voltage drop across the ohmic resistor can be comparatively low. However, this may entail the disadvantage that it may be necessary for this purpose, in order to ensure the same filter curve of the RC filter circuit, to use a comparatively high capacitance of the capacitor. This can result in increased costs.
Technologies are also known in which an operational amplifier is used as buffer for the RC filter circuit. The operational amplifier has a comparatively high input resistance, for example in the gigaohms range. In this way, only a particularly low current can flow through the ohmic resistor of the RC filter circuit. However, such an operational amplifier often causes increased current consumption, an offset, increased signal noise, increased temperature drift and generally increased complexity.
Therefore, there is a need for improved circuits which provide a voltage filtered by an RC filter circuit to a load. In particular, there is a need for technologies which ensure stability of filter characteristics of the RC filter circuit even when there is a coupled load with a finite input resistance.


An inspection unit in which a probe card is united with a connection body via a vacuum chamber. It prevents flatness of tips of probes provided on the probe card from worsening when the probe card is united with a connection body by suction force (negative pressure) of the vacuum chamber. The inspection unit includes a probe card with probes on a first surface and a connection body united with a second surface of the probe card via a first vacuum chamber. The first chamber is formed with a plurality of chambers.

Conventionally, an energization test is performed on test objects, such as semiconductor integrated circuits, to determine whether or not the test objects are produced to the exact specification. An inspection device, to which an inspection unit provided with a probe card having probes which are pressed against respective electrodes of the test object is attached, is used in such an energization test. An inspection unit of this type is used to connect the electrodes of a test object to a tester electrically for inspection.
An inspection unit for use in such an energization test includes, a probe card having a plurality of probes to be brought into contact with a test object on a first surface, a pogo pin block located on the side of a second surface of the probe card, a wiring board located on the opposite side of the probe card with respect to the pogo pin block and electrically connected to the probes of the probe card via pogo pins extending through the pogo pin block, and a reference body located on the opposite side of the pogo pin block as a connection body with respect to the wiring board to prevent the probe card from being bent or distorted. The inspection unit is assembled by uniting the probe card, the pogo pin block, the wiring board, and the reference body, with fastening means.
The number of probes mounted on the probe card is at least several hundreds, and sometimes as many as several tens of thousands.
In the conventional probe described above, when inspection of a test object is repeated, an amount of protrusion from the probe card, i.e., height, is reduced due to wear or some other reason. Then, the worn probes cannot contact the corresponding electrodes of the test object.
The inspection unit cannot fulfill its full function as an inspection unit even when one probe does not contact the corresponding electrode of the test object due to wear or some other reason. In this case, the inspection unit must be replaced with a new one. However, the replacement of the entire inspection unit, including the pogo pin block, the wiring board, and the reference body, for wear of only one probe is such a waste considering efficient use of the component parts, and it places a significant economic burden on the user.
As a remedy, there is a test object inspection device in which the probe card is detachable from other constituent members of the inspection unit so that only the probe card, not the entire inspection unit, can be replaced (refer to Patent JP 2012-163410 A).
FIG. 1 of JP 2012-163410 A illustrates an inspection unit including the probe card supported by a card table at its periphery, the pogo pin block, the wiring board, and a performance board as the "reference body." In this inspection unit, the probe card is separable from the pogo pin block, the wiring board, and the performance board (reference body). The separable structure is as follows.
The probe card and the performance board (reference body) are united together by a suction force based on the negative pressure in a vacuum chamber formed therebetween. The probe card and the performance board (reference body) are united together when a negative pressure is created in the vacuum chamber, and the probe card and the performance board (reference body) become separable when the pressure in the vacuum chamber is returned to an atmospheric level.
The vacuum chamber is defined by a ring-shaped seal member provided between the probe card and the performance board (reference body). The seal member functions as a seal member when the probe card and the performance board (reference body) are brought into contact from a separated state. Then, when the space defined by the seal member, the probe card, and the performance board (reference body) is decompressed into a desired vacuum state (decompressed state) with a vacuum pump or the like, a vacuum chamber with a negative pressure is formed.
When the probe card and the performance board (reference body) is united together by the negative pressure, the relative position between the probe card and the performance board (reference body) is determined by an anchor (intermediate body) located between the probe card and the performance board.
When the probe card is replaced, the vacuum chamber is returned from the vacuum state to the atmospheric pressure, and the suction force created by the negative pressure disappears, making it possible to separate the probe card from the performance board (reference body). Therefore, the probe card can be replaced easily in the inspection unit.

Inspection unit, probe card, inspection device, and control system for inspection device


A fluid machinery comprises a helical mechanism provided with a cylinder, a roller eccentrically disposed inside the cylinder and formed with a helical groove and a blade member fitted in the helical groove, an electric motor unit connected to the helical mechanism through a rotational shaft, the roller, which eccentrically rotates, having an engagement portion engaged with a crank portion of the rotational shaft, and a pair of bearings disposed to both axial end portions of the cylinder so as to support the rotational shaft. The engagement portion of the roller and the bearings are formed with through holes for ventilation, respectively.

The present invention relates to a fluid machinery of a helical structure adapted to continuously deliver a fluid to be compressed in an axial direction thereof, and more particularly, relates to a fluid machinery provided with an air cooling system.
An indoor type air conditioner, a refrigerator, a freezing chamber such as freezing showcase or like is assembled with a freezing cycle or freezing system, and such freezing cycle is incorporated with a compressor for compressing a refrigerant or cooling medium. Such compressor includes a reciprocal type one or rotary type one, but in recent years, a helical type compressor utilizing a helical blade for a compressing mechanism has been developed.
One example including such helical type compressing mechanism is disclosed in Japanese Patent Laid-open (KOKAI) Publication HEI 11-132176, in which a lubricating oil for lubricating a sliding portion of the compressing mechanism is generally utilized for cooing a machinery chamber, motor or like.
However, for the purpose of using a freezing cycle utilizing the helical mechanism, it is not always desired to use the lubricating oil, and such requirement is not satisfied by the helical compressor disclosed in the above prior art publication. Hence, it has been desired to provide a fluid machinery having a compact structure capable of cooling the helical mechanism without utilizing any lubricating oil.
An object of the present invention is therefore to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a fluid machinery, which comprises:
a helical mechanism provided with a cylinder, a roller eccentrically disposed inside the cylinder and formed with a helical groove and a blade member fitted in the helical groove;
an electric motor unit operatively connected to the helical mechanism through a rotational shaft so as to drive the helical mechanism, said roller, which eccentrically rotates, having an engagement portion engaged with a crank portion of the rotational shaft; and
a pair of bearings disposed to both axial end portions of the cylinder so as to support the rotational shaft, the engagement portion of the roller and the bearings being formed with through holes for ventilation, respectively.
According to the fluid machinery of this aspect, the helical mechanism and the electric motor unit can be cooled by the air without utilizing lubricating oil or like cooling medium. Furthermore, the rotational shaft has a small eccentricity in comparison with the rotational shaft of a conventional reciprocal compressor, rotary compressor or like, so that the cylinder or like member can be made compact, thus providing a compact fluid machinery.
In preferred embodiments or examples of the above aspect, the fluid machinery further comprises a fan mounted to an axial end portion of the rotational shaft. The fan may be disposed on the side of the helical mechanism or on the side of the electric motor unit.
The cylinder is formed of an aluminium including material such as aluminium alloy.
The cylinder is provided, at an outer periphery thereof, with fins for heat radiation.
The helical groove has a pitch gradually reduced along an axial direction of the roller.
The helical groove has a pitch substantially equal along an axial direction of the roller.
The cylinder has an outer periphery to which fluid suction port and fluid exhaust port are formed for the fluid to be delivered by the helical mechanism.
The fluid machinery may further comprises a cylindrical case into which the helical mechanism and the electric motor unit are accommodated, the cylindrical case being provided with openings for ventilation formed to both axial end portions thereof.
The cylinder has an outer periphery secured to an inner periphery of the case so as to define a ventilation space therebetween. The outer periphery of the cylinder has a cross section of the shape substantially the same along an axial direction thereof.
According to such preferred embodiments, the location of the fan at the end portion of the rotational shaft allow the helical mechanism and the motor unit to be effectively cooled by air and to be aligned with the shaft, making possible to provide a compact structure of the fluid machinery.
Since the cylinder is formed from an aluminium including material, the heat radiation from the cylinder can be enhanced. This heat radiation will be further enhanced through the fins formed to the outer periphery of the cylinder.
Since the engagement portion of the roller of the helical mechanism and the main and counter bearings mounted on the rotational shaft to support the same are provided with the through holes for ventilation, the bearing, the roller and the helical blade of the helical mechanism can be effectively cooled.
Furthermore, in a case where the helical groove is formed to have a pitch gradually reduced along an axial direction of the roller, so that a small sized air-cooling helical compressor may be provided. Further, in a case where the helical groove has a pitch substantially equal along an axial direction of the roller, a small sized air-cooling helical pump may be provided.
Still furthermore, the fluid machinery may further comprises a cylindrical case into which the helical mechanism and the electric motor unit are accommodated with a space or gap therebetween, and the cylindrical case being is provided with openings for ventilation formed to both axial end portions thereof. In this example, the cylinder can be cooled more effectively.
The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.

Fluid machinery having a helical mechanism with through holes for ventilation


An object of the present invention is to provide an ion milling apparatus capable of processing deposits attached to an ion gun and an ion milling method capable of processing deposits attached to an ion gun. The ion milling apparatus includes gas injection means for injecting a gas toward the ion gun, and the gas injection means included in the ion milling apparatus moves the deposits attached to the ion gun by injecting the gas toward the inside of the ion gun.

An ion milling method is known as one of methods for preparing a section of a sample for a purpose of analyzing by a scanning electron microscope.
An ion milling apparatus which performs the ion milling method is configured to include a sample chamber, an ion gun, a sample stage, a vacuum evacuation mechanism, and the like.
Examples of the ion gun which can be applied to the ion milling apparatus include, for example, a Penning-discharge-type ion gun. In PTL 1, an ion gun is disclosed for a purpose of decreasing an amount of sputtered particles which are deposited on an anode. The ion gun includes a first chamber, and an ion generation unit which generates ions by ionization of a gas in the first chamber. The ion generation unit includes an anode which is provided in the first chamber, a first cathode which is provided so as to face the first chamber and emits electrons, a gas supply unit which supplies a gas to the first chamber, and a magnetic field generation unit which generates a magnetic field in the first chamber. The electrons emitted by the first cathode are turned by the magnetic field generated by the magnetic field generation unit, and the turned electrons come into collision with the gas supplied by the gas supply unit, thereby generating the ions in the first chamber. An ion source with irregularities is provided in a first region of the front surface of the first cathode that faces the first chamber.

Ion milling apparatus and ion milling method


A method and a circuit arrangement for two-line comb filtering a sampled and digitized composite color signal are disclosed wherein, depending on the similarity status determined by means of a display area (27) via a local and temporal gradient analysis, the respective type of luma/chroma separation, namely two-line combing, combing up, combing down, or simple decoding, and the respective proportion of combing and simple decoding in the luma and chroma output signals (LO-21, CO-21) are determined for each pixel.

1. Field of the Invention
The present invention relates to a method of and a circuit arrangement for processing color video signals, particularly NTSC color television signals.
2. Brief Description of the Prior Art
In the NTSC standard, the phase of the chroma signal is reversed on successive horizontal lines and, thus, inverted. This condition lends itself to comb filtering to separate the luminance components from the chrominance components. For the sake of simplicity, luminance will hereinafter be referred to as "luma" and chrominance as "chroma". In comb filtering, successive horizontal lines of the video signal are added and subtracted together. The addition provides the luma signal component (the chroma components are oppositely phased and are thus cancelled in the addition), and the subtraction provides the chroma signal component (the luma components are cancelled in the subtraction because thev are always in phase). Comb filtering produces high-quality separation of the chroma and luma signals except where there are significant changes in the luma or chroma signal from line to line. In those cases, comb filtering introduces distortions and artifacts because of the dissimilar information that is being combined.
In color signal processing without comb filtering, hereinafter referred to as "simple decoding", the luma-chroma compbsite signal is passed through a selective color sub-carrier frequency trap (=color trap) to obtain the luma component, and through a chroma bandpass filter to cbtain the chroma component. The 3.58-MHz color trap destroys luma resolution in that frequency range. The band-pass filter, which has a mid-frequency of 3.58 MHz, also passes luma components which mix with the chroma components, thus creating untrue colors. The benefit of comb filtering is that luma resolution is not reduced in the vicinity of the color subcarrier frequency, and that color decoding is not disturbed by luma components. On the pther hand, comb filtering of video signals which have significant vertical transitions, particularly color transitions, produce various artifacts that can be very disconcerting to a viewer.
A certain remedy for these disturbing effects is provided by the well-known "two-line comb filter", which combines the video signals from three horizontal lines, e.g., the line of concern and one line above and one line below. In that two-line comb filter, luma/chroma separation by comb filtering is effected only when there are no vertical transitions present. If vertical transitions exceed a predetermined level, e.g., a noise threshold, no signal combing is performed. The prior art circuit samples vertically aligned pixels from the line above and the line below, and compares the sample values with a reference value formed from the sample values of horizontally aligned pixels. It then makes a decision as to whether to "two-line comb" (upper and lower horizontal lines with the center horizontal line) or to simple decode the video signal. The sampled video display area includes seven video pixels; five adjacent pixels on the horizontal line being processed, one pixel on the line above, and one pixel on the line below. The comparison is performed essentially only with the chroma component of the pixels, because the video signal was previously filtered by means of a chroma bandpass filter.
The decision to either two-line comb process or to simple decode is based upon comparing the differences between the two vertically aligned pixels in the upper and lower lines and the difference between the end pixels of the horizontally aligned pixels (=line). The prior art circuit thus covers only the two main directions in the vicinity of the pixel to be processed. The system lacks, for example, any diagonal comparisons of pixels and is consequently limited in its ability to determine when comb processing is desirable. Consequently, the prior art system often introduces undesirable artifacts into the video display since proper combing operation does not occur at many critical situations where the line at the center is different from the two upper and lower lines. Further, the prior art circuit is highly noise-sensitive since the noise threshold is fixed and not adaptive to the incoming video signal.

Two-line comb filtering with spatial mixing


There is provided a method for producing an aqueous dispersion of fluorine-containing seed polymer (B) particles, comprising a step for preparing an aqueous dispersion of fluorine-containing polymer (A) particles by polymerizing monomer comprising at least one fluoroolefin in an aqueous dispersion in the presence of a compound (1) represented by the formula: CH2═CHCH2—O—R, wherein R is a hydrocarbon group which may have an oxygen atom, a nitrogen atom and/or a polar group, and (II) a step for seed-polymerizing ethylenically unsaturated monomer with the fluorine-containing polymer (A) particles in the aqueous dispersion of the fluorine-containing polymer (A) particles. The production method is the method for producing an aqueous dispersion of fluorine-containing seed polymer particles and assures a low foamability and gives an excellent gloss of an obtained coating film and excellent adhesion to a substrate when the fluorine-containing seed polymer particles are used as a coating film forming component of a coating composition.

Fluorine-containing polymers have excellent chemical resistance, solvent resistance, heat resistance and antifouling property and thus have been used as a starting material of various products utilizing these properties in various industrial fields such as automobile industry, semiconductor industry, chemical industry and coatings.
The production of these fluorine-containing polymers has been performed by an emulsion polymerization, a suspension polymerization or a solution polymerization of a fluoroolefin. Generally, a surfactant is used in the emulsion polymerization method, and as the amount of the surfactant to be used increases, the number of polymer particles formed in the initial period of the emulsion polymerization increases. As a result, the polymerizing speed becomes fast and the production efficiency of the fluorine-containing polymer improves. However, the use of a large amount of surfactant tends to decrease various properties such as water resistance of the obtained fluorine-containing polymer. Therefore, the development of the production method which can perform a polymerization efficiently in the presence of a small amount of surfactant and does not have a bad influence on various properties of the fluorine-containing polymer has been desired.
In such circumstances, a production method of a fluorine-containing polymer in which a surfactant of a straight chain aliphatic sulfonates is used, in order to replace an expensive ammonium perfluorooctanoate which is generally used in the emulsion polymerization of a fluorine-containing polymer, is proposed (Patent Document 1). However, this method has a problem that the number of generated particles is small.
Further, a production method using an alkyl phosphoric acid or an ester thereof (Patent Documents 2 and 3) and a method using a compound in which a phosphoric acid, a sulfonic acid, a carboxylic acid or the like is bonded to a quaternary carbon atom (Patent Document 4) are proposed as a method using a non-fluorine-containing surfactant.
However, in the case of using an alkyl phosphoric acid or an ester thereof, the method is not always enough in terms of the number of generated particles, a polymerizing speed, a molecular weight of the obtained polymer, a polymer concentration of an aqueous dispersion, a polymerizing temperature, a polymerizing pressure and the like. Also, in the method using a compound in which a phosphoric acid, a sulfonic acid, a carboxylic acid or the like is bonded to a quaternary carbon atom, a further increase of generated particles is desired.
On the other hand, fluorine-containing materials are expensive, and the amount to be used thereof is tried to be decreased. One example is a method of seed-polymerizing ethylenically unsaturated monomer such as an acrylic acid with fluorine-containing polymer particles (Patent Document 5).

Method for producing aqueous dispersion of fluorine-containing seed polymer particles and aqueous coating composition and coated article thereof


The nacelle of the aircraft is purged and the sidewall of the vector nozzles of the gas turbine engine in the nacelle is cooled by utilizing the engine fan air to drive ejector pumps mounted in series flow relationship, a rectangular mixing zone and a diffuser with a rectangular cross section and a step in the exhaust nozzle gaspath. This results in minimizing the amount of fan air for driving the system and enhancing engine thrust and enhanced sidewall cooling because the temperature of the mixed air is lower than heretofore known systems.

As is well known in aircraft technology, it is abundantly important to prevent gasses escaping from the aircraft engine from migrating into the nacelle and accumulating to the point where the gasses would combust and either cause fires or explosions. It is customary to purge the nacelle so as to avoid such occurrences. Current techniques for purging the nacelle is to locate a pump adjacent to the exhaust nozzle or at the front of the nacelle and purge the air that is contained in the nacelle through exhaust ports located at the tail end of the aircraft. Obviously, this entails pressurizing the stagnated gasses to assure that the proper exhaust flow is maintained throughout the operating envelope of the aircraft. The increase in pressure requires larger pumping apparatus resulting in heavier support structure that is necessary to attain the structural integrity of the aircraft and the engine parts which increases overall system weight and hence, incurs an engine operating performance deficit.
One type of pump heretofore utilized for this purpose is an ejector pump that utilizes fan discharge air as the primary fluid and dumps the entrained nacelle air directly overboard. The use of fan air for this purpose and in this manner penalizes engine performance as the fan air would otherwise be used for generating thrust.
Also well known in this technology is that there is concern in expending the cooling air after it has accomplished its cooling and ventilating functions. Ideally, it is desirable to dump the spent air into the gas path without incurring a penalty or more importantly to utilize any remaining energy in the spent air to augment the engine's thrust. It is also important in this technology to pump nacelle cooling air at flow rates and pressures sufficient to be entrained into the nozzle gaspath flow for sidewall cooling. Typically, one of two sources have heretofore been utilized for sidewall cooling. One of the sources is the fan air which is at a pressure higher than required to drive the flow and is also at relatively high temperatures which results in poor cooling and as mentioned above comes at the expense of engine performance. When fan air is used for cooling, the pressure must be throttled to minimize delta pressure (.DELTA.P) across the cooling liner. Thus, the energy that is used to raise the pressure of the fan air is essentially wasted when the pressure is reduced back to the required level. The other source is the ambient air that is entrained in the nacelle which has sufficiently low temperatures that would provide efficient cooling, but its pressure is too low for it to penetrate into the engine's gas path and flow therein.
We have found that we can obviate the problems enumerated in the above paragraphs and obtain sufficient sidewall cooling and nacelle purging without unduly sacrificing engine performance. The invention contemplates a supersonic jet pump using two ejectors in series that minimizes utilization of fan air and maximizes use of ambient air to attain sufficient flows at the required pressure level and including means for discretely dumping the cooling air in the gaspath.

Nacelle air pump for vector nozzles for aircraft


Patch preparations for percutaneous adsorption with the use of supports showing appropriate strength as a patch support, which are excellent in drug barrier characteristics, compatibility with the skin, ODT effects and handling characteristics and can sustain these specific properties in a stable state over a prolonged period of time, thus ensuring good percutaneous absorption of drugs. In these patch preparation, use is made as the support of polyester film/nonwoven vinylon fabric laminates showing an elongation percentage of at least 5% and a tensile cutting load of at least 0.5 kg/10 mm, when measured by the test method specified in JIS K6732. In particular, the thickness of the polyester film constituting the laminate supports ranges from 1.5 to 6.0 .mu.m and the unit weight of the nonwoven vinylon fabric ranges from 3 to 12 g/m.sup.2.

The backing for the conventional plasters for percutaneous absorption may be polyvinyl chloride film; olefin films such as polyethylene and polypropylene; polyurethane film; polyester/polyethylene-vinyl acetate copolymer (EVA) laminated film; EVA/non-woven fabric (rayon) laminated film or non-woven fabric of polyester/polyester laminated film, and these are very thin.
These backings except for polyester/EVA laminated film are used to produce the plaster for the active ingredient having systemic effect such as isosorbide dinitarate and amyl nitrite which possess the characteristic of sublimation and fugacity. However, there are same cases that the active ingredient in the adhesive base material is absorbed by the backing, and diffused from the adhesive base material. Therefore, the plasters have to be stored in sealed condition. However, during the storage, the active ingredient contained in the adhesive base material may decrease by diffusing and absorbed to the container. As a result, the stable drug releasing from the adhesive layer may not be obtained.
On the other hand, to prevent diffusion and absorption of the active ingredient to the backing, the polyester/EVA laminated film can be used to the backing of the plasters. However, because the close, adhesion to the skin is expected, the plaster must be laminated in thin layered composition preferably having thickness from 15 to 40 .mu.m. Therefore, the plaster using the polyester/EVA laminated film as backing has same problems of the curl caused by static electricity and internal stress when applied to the skin.
To overcome these disadvantages, it has been proposed to use the backing which is laminated with polyester film and non-woven fabric of polyester (Japanese Patent Publication No. Hei 5-309128). Nevertheless, even in the case of using the proposed backing, there are still same disadvantages. For example, in the case of containing the oily absorption accelerant, such as oleic acid, isopropyl myristate or crotamiton in the adhesive base material, these oily substance may be absorbed to the non-woven fabric of polyester. Therefore, the releasing capability of the active ingredient from the adhesive base material decreases as the time passes by. Additionally, the plaster may be torn when the polyester film is thin (i.e. less than 1.5 .mu.m), and the unit weight of non-woven fabric of polyester is less than 6 g/m.sup.2. As a result, the backing for the plaster satisfied all expectations has not been available.

Patch preparations for percutaneous absorption


A box-like cigarette pack has an innerframe which initially extends upward into what is normally a cutout in the front of the innerframe. This extension may then continue over the top of the cigarettes in the pack. The innerframe is weakened along the line which normally defines the cutout. When the consumer first opens the pack, he or she can remove the innerframe extension by tearing or separating along this line of weakening. Thereafter, the pack is like a normal pack. Additional information can be printed on the removable portion or portions of the innerframe. If provided, the portion which initially extends over the cigarette tops is a convenient size for use as a coupon or the like.

This invention relates to cigarette packs, and more particularly to cigarette packs in the form of boxes.
Cigarette packs in the form of boxes are extremely well known. One of the most popular forms of such boxes has a cardboard outer member which includes a lower main portion in which the cigarettes stand vertically. The upper portion is a cardboard lid which is often (although not always) hinged to the back of the main portion so that the upper ends of the cigarettes are exposed when the lid is tipped back. Such boxes typically have a cardboard innerframe inside the main portion and which extends up from the main portion under the lid to provide some interference with the lid as it opens and closes. This interference helps to keep the lid firmly and neatly closed and reduces the risk that the lid will open accidentally. The cigarettes may be wrapped in aluminum foil inside the outer member and the innerframe.
Cigarette packs of the foregoing type are relatively small and strong. The visible exterior surfaces are needed for brand-identifying information, contents specifications, warning labels, etc. There is therefore no room on the outside of the pack for additional information such as promotional coupons, and even if such additional information could be put on the outside of the pack, it would be difficult for the consumer to free that information (such as a coupon) from the pack. Placing coupons or other information separately in the pack is disadvantageous because it necessitates additional processing steps and production equipment, because it may not be noticed by the consumer, etc.
It is therefore an object of this invention to provide a cigarette pack having additional surface areas which can be used for a coupon or other information.
It is another object of this invention to provide a cigarette pack including additional information area which cannot be overlooked by the consumer, but which can be easily removed and either saved or discarded as desired.
It is still another object of this invention to provide a cigarette pack having an additional but removable information area, which pack functions as a standard pack after the additional information area is removed.

Cigarette pack with partly removable innerframe


A portable window wiper for attachment to a vehicle door to reciprocally clear moisture from an adjacent window. The wiper includes a housing having a bracket projecting therefrom which may be inserted between a base of the window and an adjoining portion of the vehicle door. An electric motor in selective communication with a vehicle lighter socket reciprocates a wiper arm across the window. A wiper blade is pivotally mounted to the wiper arm to effect the cleaning and clearing of the window surface. The device permits the driver of a truck vehicle or the like to see the side view mirrors clearly during forward operation and backing of the vehicle.

1. Field of the Invention
The present invention relates to wipers and more particularly pertains to a portable vehicle window wiper for attachment to a vehicle door to reciprocally clear moisture from an adjacent window.
2. Description of the Prior Art
The use of wipers is known in the prior art. More specifically, wipers heretofore devised and utilized for the purpose of clearing moisture from a section of glass material are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
For example, a windshield wiper assembly is illustrated in U.S. Pat. No. 5,068,942 which consists of an endless belt positioned beneath a windshield with the belt extending substantially the length of the windshield and supporting a wiper mounted to an inner side of the belt. A drive is provided for continuously rotating the belt to cause a blade held by the mounting to rapidly move back and forth across the entire windshield.
Another patent of interest is U.S. Pat. No. 4,527,301 which teaches a side view mirror truck windshield wiper for extended side view mirrors on trucks or the like. The windshield wiper utilizes a pneumatic cylinder supported on a wiper support frame to effect a reciprocal movement of a wiper blade connected thereto. The wiper support frame is connected with the mirror in a co-planar relation and may be used as a handle to adjust the mirror as the mirror and wiper support frame are secured together as a unit.
Other known prior art wipers include U.S. Pat. No. 4,736,485; U.S. Pat. No. 5,140,241; and Design U.S. Pat. No. 331,556.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a portable window wiper for attachment to a vehicle door to reciprocally clear moisture from an adjacent window that includes a housing having a bracket projecting therefrom which may be inserted between a base of the window and an adjoining portion of the vehicle door, with an electric motor operable to reciprocate a wiper arm and its associated windshield wiping blade across the window.
In these respects, the portable vehicle window wiper according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of reciprocally cleaning and clearing moisture from an adjacent window.


A turbine shroud adapted for use in a gas turbine engine includes an attachment feature and a body. The attachment feature and the body are constructed of ceramic matrix composite materials. In an illustrative embodiment, the ceramic matrix composite materials form a blade track segment.

Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine and may provide thrust in some applications.
Compressors and turbines typically include alternating stages of static vane assemblies and rotating wheel assemblies. The rotating wheel assemblies include disks carrying blades around their outer edges. When the rotating wheel assemblies turn, tips of the blades move along blade tracks included in static shrouds that are arranged around the rotating wheel assemblies. Such static shrouds may be coupled to an engine case that surrounds the compressor, the combustor, and the turbine.
Some shrouds positioned in the turbine may be exposed to high temperatures from products of the combustion reaction in the combustor. Such shrouds sometimes include blade track segments made of ceramic matrix composite materials designed to withstand very high temperatures.

Ceramic matrix composite blade track segments

Rolls-Royce High Temperature Composites Inc.

Rolls-Royce North American Technologies Inc.


A method for a Mobile Mobility Entity (MME) to carry out mutual authentication with a group of Machine Type Communication (MTC) devices includes receiving group-related authentication data from a leader, transmitting the received information and an identification number of the MME, to a HSS, receiving from the HSS a random value, an Authentication Vector and information of group members, broadcasting the random value and the first authentication token to the MTC device group based on information received from the HSS, receiving from the leader a leader authentication response that the leader generates by using a local master key value calculated by using the first secret key value, authenticating the leader by comparing the leader authentication response with a leader authentication value received from the HSS, and authenticating members within the MTC device group according to the leader authentication result.

Field of the Invention
The present invention is related to a mutual authentication method with a network and a system using the method; and more particularly, a method for a group leader to carry out mutual authentication with a network in Machine-Type Communication (MTC) and a system using the method.
Discussion of the Related Art
Machine-to-Machine (M2M) communication enables millions of machines to communicate with devices in the surroundings of the machines through wired or wireless connection. Multitude of new applications within tracking, monitoring, maintenance, and security categories are emerging as M2M communication comes into reality. Similar to M2M communication, the 3rd Generation Partnership Project (3GPP) defines the communication between devices and ordinary things which does not involve human intervention as Machine Type Communication (MTC), and standardization for the communication method is being carried out. The 3GPP defines group-based MTC features for the purpose of managing a plurality of MTC terminals in an efficient manner, but backgrounds of and policies for introducing MTC groups are mentioned only briefly without in-depth discussion thereof.
In particular, a method for using delegation-based authentication is one of the methods studied in an attempt to reduce requirements of authentication signaling which cause many problems when MTC communication is performed. In this method, an authentication server authenticates a device by signaling its own authentication signal that can be verified by a serving network. The device does not require other method for accessing the authentication server than receiving the aforementioned authentication signal. However, such a kind of method requires a public key infrastructure and thus suffers a problem since it is not compatible with current secret key systems.
In another method, devices are grouped and serving networks are allowed to have a group leader. A leader, on behalf of all of the MTC devices, authenticates itself to the network. Dynamic Group Based And Key Agreement (DGBAKA) and Group-based AKA (G-AKA) are two security protocols for authenticating a group of MTC devices. Due to the grouping model, the aforementioned two protocols can reduce communication costs in a network. However, since the two protocols define a procedure for authentication among a group leader and group members in a more or less inefficient manner, the overall complexity of a system is increased as the number of MTC devices becomes large.
EAP-based Group Authentication (EG-AKA) and Secure and Efficient (SE) AKA are group AKA protocols for LTE networks. The overall delay of a current AKA with respect to a single user is large due to a round-trip delay of the authentication server within a core network to and from a backend. To alleviate the delay, the EG-AKA and the SE-AKA have been designed to reduce the number of access to the authentication server. In other words, only the first member within a group is required to perform handshake with the authentication server for authentication. The other members are authenticated by a gateway located close to the authentication server. Since a single group key is shared among group members, a member can overhear private communication of other members. Taking this fact into consideration, these protocols enable forward and backward secrecy of Elliptic Curve Diffie-Hellman (ECDH). However, it should be noted that the protocols above adopt asymmetric key encryption to protect privacy of devices. Therefore, the ECDH and asymmetric encryption may not be appropriate for those MTC devices in a lack of resources.
In other words, the conventional methods are unable to completely solve the problem of congestion and overload in authentication signaling in the LTE or LTE-Advanced (LTE-A) network, and until recently, it was not clear whether signaling traffic among MTC devices had been managed in a productive manner.

Mutual authentication method and system with network in machine type communication

Research & Business Foundation Sungkyunkwan University


An aluminum-nickel-chromium (Al-Ni-Cr) layer used as an interconnect within a semiconductor device is disclosed. The Al-Ni-Cr layer has about 0.1-0.5 weight percent nickel and about 0.02-0.1 weight percent chromium. Usually, the nickel or chromium concentrations are no greater than 0.5 weight percent. The layer is resistant to electromigration and corrosion. The low nickel and chromium concentrations allow the layer to be deposited and patterned similar to most aluminum-based layers.

Aluminum is widely used for interconnects in semiconductor devices. However, aluminum has been found to be susceptible to a number of problems that may lead to device failure. Component densities (number of components per substrate area within an integrated circuit) typically are becoming higher as the size of components within a semiconductor device become smaller. The higher component density typically causes higher current densities in conductive layers when the device is operating. The higher current density generally results in an increase of device failure because of electromigration, which is a current-induced mass transport that is a function of current density and temperature of the device. Pure aluminum has problems with electromigration. In addition to electromigration, corrosion of the aluminum is a problem and is usually caused by chlorine exposure to the aluminum in an ambient including water, such as air exposure of an aluminum layer immediate following a dry etching step using chlorine-containing chemistry.
In an attempt to solve the problems discussed above, an element, such as silicon (Si), copper (Cu), nickel (Ni), or chromium (Cr) has been added to aluminum to form alloys. In reality, these alloys either do not solve all of the problems previously discussed or cause other problems. Electromigration is typically measured in terms of median-time-to-fail (MTTF) for a given current density and temperature. At a current density of about 4.times.10.sup.6 amperes per square centimeter and a temperature of about 175 degrees Celsius, the MTTF for Al-Cr is reported to be about 830 hours and that of Al-Ni is reported to be only about 300 hours.
In addition, many aluminum alloys do not etch similar to aluminum and require aggressive processing conditions that may attack other portions of the semiconductor device, such as silicon dioxide. Therefore, new process steps may need to be developed. Also, when the concentrations of some of the elements in the aluminum alloy become too high, the resistance of the conductive layer may be too high.

Process for forming a conductive layer for semiconductor devices


The present invention relates to 3-(cis-2,6-dimethylpiperidino)sydnone imine salts of the general formula I ##STR1## in which X denotes H.sub.2 PO.sub.4 or ##STR2## processes for their preparation and their use.

1. Field of the Invention
The present invention relates to 3-(cis-2,6-dimethylpiperidino)sydnone iminium dihydrogen phosphate and hydrogen tartrate, processes for their preparation and their use.
2. Discussion of the Prior Art
3-(2,6-Dimethylpiperidino)sydnone imine hydrochloride and its pharmacological properties have already been described in EP-B 327,808. However, it has the disadvantage that, on standing, it absorbs water under the influence of atmospheric humidity. The amount of absorbed water here is dependent on the temperature and the relative atmospheric humidity.
The hydrochloride is thus barely utilisable for the standardisation of pharmaceutical preparations, for which precisely defined amounts of active compound are prescribed by the legislature. The stability of pharmaceutical preparation forms, such as, for example, tablets, is also not conferred.
The object of the present invention is to bring the active compound into a non-hygroscopic form which fulfils the pharmaceutical requirements.

Salts of 3-(cis-2,6-dimethylpiperidino) sydnone imine


An exemplary voltage correction circuit includes a high-pass filter coupled with an integrated load, and an active clamp coupled with the high-pass filter in a closed-loop feedback arrangement. The high-pass filter includes an impedance network having a frequency response defining a lower frequency boundary of a passband of the voltage correction circuit, and the active clamp has a frequency response defining an upper frequency boundary of the passband of the voltage correction circuit. The active clamp is adapted to receive an input voltage proportional to a load transient within the passband and to generate an output current of the voltage correction circuit that cancels the effects of the load transient. A loop gain of the voltage correction circuit is greater than or equal to one within the passband and is less than one for frequencies lower than the lower frequency boundary and higher than the upper frequency boundary.

Voltage regulators are ubiquitously used in electronic circuitry and electronic systems and are critical in maintaining the voltage of a power source within acceptable limits; that is, a voltage regulator is necessary to keep voltages within a prescribed range that can be tolerated by the electronic circuitry or system using that voltage. Voltage regulators are used in electronic equipment in which excessive variations in voltage would be detrimental. For example, electronic voltage regulators are found in devices such as computer power supplies where they stabilize the direct current (DC) voltages used by the processor and other circuit components.
There are various categories of voltage regulators, each class having a characteristic circuit architecture and application. Active regulators represent one category of voltage regulators that employ at least one active component, such as a transistor or operational amplifier, and include linear regulators, switching regulators and silicon controlled rectifier (SCR) regulators. Moreover, within these categories, there are often sub-categories of voltage regulator topologies. For example, linear regulators are often classified into series regulators and shunt regulators.
Switching regulators are one common type of voltage regulator. In simple terms, switching regulators rapidly switch a series element on and off, with a duty cycle of the switch controlling how much charge is transferred to a load connected to the regulator. This duty cycle is controlled by a feedback mechanism similar to the feedback scheme used in a linear regulator. Because the series element is either fully conducting or switched off, it dissipates almost no power, thus giving the switching regulator its characteristic high efficiency compared to, for example, linear regulators. One disadvantage of switching regulators, however, is that they require an inductor that acts as an energy storage element, which when integrated on a die, consumes substantial area and requires additional semiconductor process layers.

Integrated voltage correction using active bandpass clamp