The present invention discloses proteinaceous compounds that comprise at least a biologically active portion of a taipan natriuretic peptide (TNP) or a variant or derivative thereof. The invention also relates to the use of these compounds in methods for stimulating vasodilation, natriuresis, diuresis, renin-suppression, bactericidal activity, weight-loss or bone growth in a mammalian host. In specific embodiments, the compounds are useful in the treatment of congestive heart failure.

Natriuretic peptides (NPs) are known for their role in cardiovascular homeostasis, diuresis, natriuresis and vasodilation. They act in the body to oppose the activity of the renin-angiotensin system and enhance excretion of sodium and water. There are four known types of natriuretic peptides in humans: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), S-type natriuretic peptide (CNP) and dendroaspis natriuretic peptide (DNP). Isoforms of these occur in nature across species.
ANP is secreted by atrial myocytes in response to increased intravascular volume. Once it is in the circulation, its effects are primarily on the kidney, vascular tissue and adrenal gland, in which its actions lead to the excretion of sodium and water by the kidneys and a decrease in intravascular volume and blood pressure (Atlas et al., 1987, In Atrial Hormones and Other Natriuretic Factors, P. J. Mulrow et al., Eds, Am. Physiol. Soc., Bethesda, Md., pp. 53-76).
BNP is of myocardial cell origin and, like ANP, circulates in human plasma (de Bold et al., 1981, Life Science, 28(1): 89-94; Burnett et al., 1986, Science, 231(4742): 1145-1147). BNP is natriuretic, renin-inhibiting, vasodilating and lusitropic (Mukoyama et al., 1991, J. Clin. Invest., 87(4): 1402-1412; Yamamoto et al., 1996, Am. J. Physiol., 271(6 Pt 2):R1529-1534; Grantham et al., 1997, Natriuretic Peptides in Health and Disease, Samson W. K. 11e.r., eds, Humana Press, pp. 309-326).
CNP is of endothelial cell origin and functions as a vasodilating and growth-inhibiting peptide (Suga et al., 1992, J. Clin. Invest., 90(3): 1145-1149; Stingo et al., 1992, Am. J. Physiol., 262(1 Pt 2):H308-312; Koller et al., 1991, Science, 252(5002): 120-123).
DNP possesses structural similarity to ANP, BNP and CNP. It was originally found in the venom of Dendroaspis angusticeps and has been shown to vasorelax rodent aorta and isolated canine coronary arteries with potency comparable to that of ANP (Schweitz et al., 1992, J. Biol. Chem., 267: 13928-13932; Wenberg et al., 1997, Am. Coll. Cardiol., 29: 305a). Recently DNP immunoreactivity has been demonstrated in human circulation, and its plasma levels are elevated in congestive heart failure (CHF) (Schirger et al., 1999, Mayo Clin. Proc., 74: 126-130). A NP-like peptide, Lebetin 2 isoform alpha, was found in the venom of Vipera lepitera (Barbouche et al., 1996, FEBS Lett. 392:6-10). This peptide contains the consensus natriuretic peptide signature which indicates that it belongs to the same general family. Illustrative examples of known natriuretic peptides are given in Table 1.
Natriuretic peptides effect their biological role through three receptors: NPR-A, NPR-B and NPR-C. NPR-A and NPR-B have cytoplasmic guanylyl cyclase domains, which are activated upon ligand binding and lead to accumulation of intracellular cGMP. The tissue distribution of each receptor is different. While NPR-A is expressed in vasculature, kidney and adrenal glands, NPR-B is mainly expressed in the brain. NPR-C, is devoid of the kinase and cytoplasmic GC domains and is generally considered to be a clearance receptor for removing natriuretic peptides from the circulation, although other biological functions for it have been postulated (Murthy et al., 1999, J. Biol. Chem., 274(25): 17587-17592). U.S. Pat. Nos. 5,846,932 and 6,028,055 disclose potent ANP and BNP variants having decreased affinity for the human clearance or C-receptor (NPR-C). DNP has been shown to produce relaxation through both the NPR-A and NPR-C receptors.
ANP and BNP each bind to both NPR-A and NPR-C with high affinity, but only bind to NPR-B with low affinity, whereas CNP binds to NPR-B and NPR-C, but not appreciably to NPR-A (Potter L R and Hunter T, 2001, J. Biol. Chem. 276: 6057-6060). It is generally considered that the beneficial effects (natriuresis/diuresis or effects on renin/angiotensin system) of natriuretic peptides occur via the synthesis of the intracellular messenger cyclic-GMP (cGMP). NPRA is thought to be the primary ANP/BNP signaling molecule and has been suggested as the principal mediator of natriuretic peptide activities. Conclusive studies have determined that NPR-A is the only NP binding receptor that regulates natriuresis/diuresis and regulates the renin/angiotensin system (Kishimoto I, et al., 1996, Proc Natl Acad Sci USA 93: 6215-6219). In this study it was demonstrated that ANP does not bind to tissues from animals that are homozygous null mutants for NPR-A. These animals do not undergo natriuresis or diuresis in response to ANP and their aortic rings do not relax in response to that peptide. Shi et al. (2003, AJP—Renal 285:694-702) established that NPRA is critical in mediating the natriuresis, diuresis, and renal hemodynamic responses to acute blood volume expansion. From these studies it is apparent that, for a NP peptide to be of use in the treatment of CHF, it must act at the NPR-A receptor.
The ability for a NP to bind human NPR-A cannot be predicted from an analysis of primary sequence alone, nor can analysis of primary sequence predict the affinity with which a NP can bind to NPR-A. The sequences of both the hormones and their receptors vary across species. A consensus NP sequence has been identified for NPs but this is loosely defined and provides no information on whether the peptide acts as an NP, and no guidance as to whether the peptide is active at NPR-A in particular (and hence potentially useful for treating CHF), NPR-B and/or NPR-C. Schweitz et al. (1992 J. Biol. Chem. 267: 13928-13932) identified DNP as a ligand for NPR-A on the basis that the peptide relaxes aortic rings. In an early attempt to define features important for NPR-A binding, they proposed a conservative tripeptide sequence in the C-terminal part of the as then known natriuretic peptides consisting of (i) a small non-hydrophilic residue; (ii) a large hydrophobic residue and (iii) an arginine residue, as highlighted in FIG. 2. However, as is evident in later studies and in the present specification, this generalization does not hold and provides little guidance as to whether a natriuretic peptide has NPR-A activity, or otherwise.
ANP, BNP, CNP and DNP are synthesized from large precursors and the mature, active peptides have a 17-amino acid ring structure formed by an intramolecular disulfide linkage. In the human peptides, ten of these amino acids are identical, whereas the N-terminal head and C-terminal tail vary in both length and composition (see Kambayashi et al., 1990, FEBS Lett, 259: 341-345; Tawaragi et al., 1991, Biochem. Biophys. Res. Commun. 175: 645-651).
Due to their diverse actions on both the cardiovascular system and the kidney, ANP, BNP, CNP and DNP and their analogues have been the subject of great interest for developing novel therapeutics. For example, reference may be made to Lewicki et al. (U.S. Pat. Nos. 5,114,923, 4,804,650 and 4,757,048), Johnson et al. (U.S. Pat. No. 5,047,397), Johnson et al. (U.S. Pat. No. 4,935,492), and Wei et al. (U.S. Pat. No. 5,583,108). U.S. Pat. No. 5,583,108 discloses a chimera of ANP and CNP, termed vasonatrin peptide (VNP). VNP, which includes 22 amino acids of CNP and the 5 amino acids at the carboxy-terminus of ANP, has arterial and venous vasodilating and natriuretic effects. U.S. Pat. No. 6,407,211 discloses chimeric compounds comprising the C-terminal tail of DNP with the core ring structure of BNP or CNP.
The above natriuretic peptides and their analogues are known to be useful for treating a variety of different conditions including: edematous states such as congestive heart failure (CHF), nephrotic syndrome and hepatic cirrhosis; hypertension; pulmonary hypertension; and renal disorders as well as diseases such as renal failure due to ineffective renal perfusion or reduced glomerular filtrate rate; bacterial infections; weight loss; asthma; inflammatory-related diseases; erectile dysfunction; hypercholesterolemia; skeletal dysplasias and as a protectant for toxicity of anti-cancer drugs, as described for example in WO 2004/011498.
Typically, heart failure patients receive several chronic oral therapies, primarily including diuretics, angiotensin-converting enzyme (ACE) inhibitors, and beta-blockers. Often, these patients have an acute episode of CHF, requiring hospitalization. Following an acute episode, survivors are required to continue management of the chronic condition. The gold standard for the treatment of more advanced CHF is quadruple therapy with an ACE inhibitor (or an ARB), a beta-blocker, a diuretic and digoxin. However, each of these is associated with a number of deleterious side-effects such as neurohumoral activation, ototoxicity, hypokalemia, renal impairment and an increased risk of arrhythmic death. It has been observed that enhancement of the NP system may provide a better strategy to treat the sodium and water retention that increases cardiac preload leading to progressive cardiac dysfunction in CHF patients (Costello-Boerrigter et al., 2003, Medical Clinics of North America 87(2)). The therapeutic potential of the NPs is underscored by the role played by ANP and BNP in overcoming sodium retention in the early phase of CHF. As CHF evolves, the balance between the antinatriuretic-vasoconstrictive systems (i.e., RAAS, sympathetic nervous system, vasopressin and endothelin) and natriuretic-vasodilatory systems (i.e., NPs, nitrous oxide, prostaglandins and adrenomedulin), which has a profound effect on sodium and water homeostasis, moves towards the former system. The current hypothesis is that there is a state of relative deficiency of NP in CHF. Consequently, enhancement of NPs is considered a beneficial strategy either via administration of exogenous NPs, through agonists of NP-A, or by inhibition of the enzyme responsible for NP degradation, NEP 24.11. In tribute to the growing recognition of NP therapy, nesiritide citrate or Natrecor®, a BNP citrate salt, has been launched commercially for the intravenous treatment of acute CHF patients in the United States. A recombinant form of hANP, termed carperitide, has been launched in Japan for the same indication and is currently in clinical trials in the USA (Pharmaprojects, 2005).
An advantage of NPs over currently used diuretics is that they do not activate the RAAS system (which is associated with the progression of CHF). Furthermore, they inhibit the sympathetic nervous system (which is associated with heart failure progression, myocyte necrosis and apoptosis, and arrhythmias). It has been demonstrated that NPs exhibit fewer arrhythmic events, such as tachycardia. In trials, BNP was reported to be associated with less arrhythmic events than dobutamine (Burger et al., 2001, Am J Cardiol 88, 35-39). NPs and their derivatives can be administered alone or in combination with one or more of the following compounds: beta blockers, diuretics, ACE inhibitors, digoxin, spironolactone, anticoagulation and antiplatelet agents and angiotensin receptor blockers, as disclosed for example in WO03081246.
A disadvantage of NPs is that they are notoriously fragile in vivo, being degraded rapidly by neutral endopeptidases (NEPs) and through the clearance receptor (NPR-C), thus limiting their bioavailability. A corollary of this is that NPs, in particular Nesritide, is only useful in the treatment of acute CHF requiring intravenous infusion. To access the chronic CHF market, new stabilized NPs are sought. Such NPs have the requirements of significantly improved half lives so that more convenient routes of administration such as subcutaneous injection or oral administration can be adopted and with less frequent dosing than would be needed for current NP therapies such as ANP or BNP, both which have short half lives.
Attempts to increase resistance to proteolytic degradation of NPs through use of PEGylation and other conjugates (see, for example, WO2004/047871), resulted in improved resistance to trypsin, oral availability and in increased plasma levels as compared to native BNP in some examples. Interestingly, analysis of animal plasma assays for its lead compound reveal that their oral delivery technology is successful, in that the hBNP survives the GI tract and reaches the blood stream. However, once in the blood stream, it is degraded and cleared quite quickly (within 30 minutes the plasma levels of the compound are almost zero), demonstrating no superiority over Natrecor's 18 minute half-life. In short, hBNP is too unstable, and therefore not amenable to oral administration. An alternative approach is bioconjugation of the NP with blood components for example human serum albumin. This technology has been demonstrated to increase NP half life (see, for example, WO 2004011498). However, the corresponding large size of the resulting complex makes it unsuitable for most forms of administration. Additionally, it is not clear that the activated NP does not conjugate to other biological species in vivo with the consequence that regulatory and safety issues may arise. Other studies have targeted the stability of NPs by selecting for analogues that favor the NPR-A receptor over the NPR-C receptor (see, for example U.S. Pat. Nos. 6,028,055 and 5,846,932), thus reducing clearance mechanisms or by stabilizing the sequence against NEP protease digestion, for example by replacing the susceptible Phe with Cha. All these studies demonstrate the general amenability of NPs, without significant loss of activity, to substitution and derivatisation provided that the primary binding moieties are not disturbed.
DNP has been found to possess higher resistance to NEPs than previously known NPs, putatively due to its extended tail region. The tail region is roughly correlated to stability, with CNP, the least stable having the shortest tail. Indeed, the significantly higher potency of BNP over ANP in elevating cGMP levels in mice kidney is attributed to the greater stability of the former peptide. Correspondingly, there still exists a need for compounds with NP-like activity that are better able to withstand proteolytic enzyme attack, particularly that of NEP 24.11.
It is not possible to determine the stability of NP peptides from an examination of their primary sequences alone. The program "Peptide Cutter" available on the suite of protein analysis programs, Swissprot (http://us.expasy.org/sprot/) predicts that all known peptides have multiple regions of susceptibility to proteolytic attack. For instance, ANP is predicted to contain 59 cleavage sites for 12 enzymes, whereas BNP is predicted to contain 55 cleavage sites for a total of 13 enzymes. The peptides of the present invention are predicted to contain 59 cleavage sites for a total of 16 enzymes. Yet, as is demonstrated herein, these latter peptides are significantly more stable than their human counterparts.

Chimeric proteins with natriuretic activity


An optical scanner emits a light beam in accordance with an image forming signal and deflects the light beam in a first direction. A scanned face is adapted to be scanned by the deflected light beam to form a scanning line while being moved in a second direction perpendicular to the first direction, thereby forming a latent image thereon. A virtual scanned face is defined as a plane including the scanning line and orthogonal to an optical axis of the optical scanner. The shape of a beam spot formed by the light beam incident on the virtual scanned face is approximated to an ellipse. The scanned face is inclined from the virtual scanned face so as to rotate about the scanning line, in accordance with an inclined angle of an major axis of the ellipse from the second direction on the virtual scanned face.

The present invention relates to an image forming apparatus and more particularly to an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer comprising an optical scanning device.
Referring to an optical scanning device to be used in an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer, Japanese Patent Publication No. 2002-365582A teaches conditions for correcting the torsion of a scanning beam (a torsion around the central axis of the beam) in a deflection optical system. Moreover, International Patent Publication No. 03/096101 teaches conditions for correcting the curvature of a scanning path.
However, the conditions for correcting the torsion of a scanning beam and the conditions for correcting the curvature of a scanning path are not coincident with each other in many cases. For this reason, it is necessary to properly balance the inclination of a scanning beam with the curvature of a scanning path in order to equilibrate with image forming characteristics and a lens coverage in an actual optical scanning device. In that case, the torsion of the scanning beam is not corrected perfectly. Alternatively, it is also possible to correct the curvature of a scanning path generated by an eccentrically provided or inclined optical face (a lens face or a reflection face) of a scanning optical system with the conditions taught in Japanese Patent Publication No. 2002-365582A. Also in that case, the torsion is generated on the beam.
When a scanning line obtained by the scanning optical system is included and a perpendicular plane to the optical axis of the scanning optical system is defined to be a virtual scanned face, the inclination of a beam spot formed on the virtual scanned face is more increased apart from a scanning center in a primary scanning direction when the torsion of the scanning beam is not corrected perfectly.
In the deflection optical system disclosed in the publications, incidence is carried out twice over a reflection face.
FIG. 12 shows such an optical system in which a deflector is constituted by a polygon mirror 10 having a plurality of reflection faces 11 (six faces in the drawing) on the side portion of a polyhedral cylinder and the reflection faces 11 are rotated around a rotary axis 12. Two fixed flat mirrors 13 and 14 are disposed so as to face one of the reflection faces 11 subjected to the light deflection. The fixed flat mirrors 13 and 14 are angled relative to each other while forming a gap 15 therebetween.
A light emitted from a light source 21 is converted into a parallel beam a0 through a lens 22. In a case where it is adopted an optical system for correcting a pyramidal angle error of the polygon mirror 10, the light beam emitted from the light source 21 is converted into a parallel light beam relative to a direction perpendicular to the rotation axis 12 of the polygon mirror 10 while being converted into a light beam to be focused in the vicinity of the reflection face 11 of the polygon mirror 10 relative to a direction parallel to the rotation axis 12 of the polygon mirror 10. The light beam a0 passes through the gap 15 between the fixed flat mirrors 13 and 14 and is incident on the reflection face 11 from obliquely below. A light beam a1 obtained by a first reflection through the reflection face 11 advances obliquely upward and is incident on the fixed flat mirror 13. A light beam a2 reflected by the fixed flat mirror 13 advances downward and is incident on the fixed flat mirror 14. A light beam a3 reflected by the fixed flat mirror 14 is incident on the reflection face 11 again. A light beam a4 obtained by a second reflection through the reflection face 11 passes through the gap 15 and advances obliquely upward, and is converted into a focused light beam through a scanning optical system 23 to be incident on a scanned face 24.
Since the reflection face 11 is rotated around the rotary axis 12, the focused light beam is moved at a rotating speed which is approximately four times as high as the rotating speed of the reflection face 11 to draw a scanning line b on the scanned face 24. With the rotation of the polygon mirror 10, the adjacent reflection faces 11 are sequentially subjected to the incident light beam a0. With the rotation of the polygon mirror 10, therefore, the scanning line b is sequentially drawn from one of ends to the other end in the same position on the scanned face 24. A member to be scanned on the scanned face 24 is moved at a constant speed in a perpendicular direction to the scanning line b, resulting in the execution of a raster scan in which the scanning line b is arranged at a constant pitch over the scanned member. When a plane including the central beam of the incident light beam a0 and parallel with the rotary axis 12 is defined as an incident plane, the two fixed flat mirrors 13 and 14 are provided perpendicularly to the incident plane.
It is apparent from the description in connection with FIGS. 19 to 21 in Japanese Patent Publication No. 2002-365582A that the same inclination of a beam spot is generated in a case where an optical system having an optical face provided eccentrically in a secondary scanning direction relative to an optical axis is used in place of the deflection optical system shown in FIG. 12.
In general, the scanned face (photosensitive face) of an electrophotographic printer is inclined relative to the optical axis of an optical scanning device such that the scanned face is rotated about a scanning line as a rotation axis. Such a provision is carried out in order to prevent a light beam reflected by the scanned face from returning to the optical scanning device to cause an unstable laser oscillation, or from being reflected by another optical component in the optical scanning device, thereby becoming ghost light irradiating the scanned face again. Moreover, an incident angle in the primary scanning direction of an incident beam is more increased apart from a scanning center, and the incidence is carried out with an angle in the primary and secondary scanning directions at the scanned face other than the scanning center. For example, even if there is no inclination of a beam spot over the virtual scanned face, the inclination of the beam spot is generated if the scanned face is provided with an inclination in the first and secondary scanning directions relative to the optical axis of the optical scanning device.
Based on a positional relationship between the optical scanning device and the scanned face, the inclinations of the beam spot which are caused by the two factors are combined. Consequently, a fluctuation in characteristics of a beam spot formed on the scanned face within the scanning range is more increased.


A method and system for storing and temporarily relocating a trash container so as to decongest a thoroughfare.

This invention relates generally to the field of refuse handling apparatus and methods. In a further and more specific aspect, the invention concerns an apparatus and method for storing and temporarily relocating a trash container.
The word "trash" refers to solid waste, garbage, refuse, recyclables or other physical objects and material that is unwanted by the person in possession. The phrase "trash container" means a structure enclosing a space that may be filled with trash, also referred to as a trash bin, refuse collection body, or similar terms. One particular type of a trash container is referred to as a trash "compactor" comprising a body that includes means for forcing loose refuse or trash into a smaller volume of greater density. The term "trash container" includes a standard (non-compaction) container and a compactor type of container. Typically, a trash compactor includes the container and a moving element, such as a piston, for compressing the loose refuse within the container; the piston may be operated by hydraulic fluid under pressure. The hydraulic pressure is produced by a power source such as an electrically operated motor that actuates a hydraulic pump so as to create a high pressure hydraulic fluid. Such power sources for compactor operation are well-known in the art.
In typical commercial refuse collection systems the compactor unit is adapted to be mounted on and transported by a suitable truck that can load and unload the compactor unit. In a typical collection cycle, a compactor unit that is filled to capacity will be loaded onto a truck where the compacted refuse is carried to a suitable refuse collection area, sometimes referred to as a garbage dump, where refuse is deposited and the emptied compactor unit may be taken back to the site where it was picked up or to another site in the event that a different truck had already placed an empty compactor unit at the pick-up site.
Efficient refuse collection requires that the trash container be large enough so as to make each vehicle trip efficient while still staying within the confines of the size of truck bodies that may be permitted on public thoroughfares. The word "thoroughfare" means an alley, street, roadway or other private or public surface for carrying motor vehicle traffic; the term 'thoroughfare level' means an area adjacent a thoroughfare that is at the same level as the thoroughfare and excludes areas below the thoroughfare level, such as a pit within or adjacent the thoroughfare. Thus, a typical trash container of the compactor type may have a width of approximately 10 feet, a height of 10 feet, and a length of between 15 and 25 feet.
The word "system" has its ordinary dictionary definition in this patent: a regularly interacting or interdependent group of items. In the context of the present invention, the system may comprise a trash container, a permanent source of hydraulic pressure, and in at least one of the embodiments of the invention, an opening in a building, including an apparatus for movably supporting a trash container from a storage position to a loading/unloading or temporary "relocated" position.
In urban areas, many city blocks include an alley between two rows of commercial or office buildings that are immediately adjacent the alley providing access to allow moving goods and equipment into and out of a building including, but not limited to, trash. Depending upon the density of the area, many of the buildings may be multi-storied and it is desirable to utilize as large a trash container as laws and regulations will allow because of the volume of trash and the desire to reduce transportation costs to the refuse collection area. Moreover, in many urban areas where alleys exist, the alleys are relatively narrow in width given current vehicle sizes because the alleys were constructed many years ago when vehicle sizes were smaller.
Because of the volume of refuse, and the size of an alley, it is highly desirable that refuse containers be proscribed from storage in any portion of the alley because such presence further creates congestion and inefficiency in collecting refuse as well as accommodating other service vendors who require ingress and egress to the building through the alley. It is also desirable to use a compactor type of refuse container so as to accommodate a large volume of trash by forcibly compressing loose trash into compact high density trash within the container. Accordingly, there is typically provided a high pressure hydraulic system as a source for producing compaction. It is an object of this invention in at least one of its embodiments to utilize the same high pressure source of hydraulic fluid for operating the compactor unit for the power required to move the apparatus for storing and temporarily relocating the compactor unit to facilitate loading/unloading on and from a transport vehicle.
Even in locations where congestion is not as great as in concentrated urban areas, or in areas where alleys are not common, for example in industrial parks, shopping malls, or other commercial or government facilities, it may be desirable to utilize standard or compaction type trash containers of substantial size and for aesthetic reasons, it may be desirable to locate the trash container where its presence is unobtrusive. In such applications, it is still desirable that the large compactor type of trash container be stored in an out-of-the-way location but can be repositioned or relocated to a second location within an alley, street, roadway, or thoroughfare where there is ready, though temporary, access for loading the container onto a refuse collection vehicle as previously described. By enabling the loading/unloading of the trash container in a public thoroughfare, where vehicle access is readily available, the trash depositor need not provide as much space on its private property as would be necessary for maneuvering a large vehicle into loading/unloading position.
It should be understood that the trash compactor units of the rough size described above, when fully loaded, may weigh many tons depending upon the type of refuse that is being collected and whether the container is a standard or compaction type of container. Thus, moving the trash container from a storage location where it is being filled over a period of time, to a loading position that provides ready access to the trash container transport vehicle, is no small task.
In summary, the apparatus and method of the present invention comprises an out-of-way storage location for receiving a trash container during periods of storage, a source of power, and a storage and relocation apparatus supporting the trash container that is moveable from the storage location to a location providing ready access for loading onto, and unloading from, a transportation vehicle.

System for storing and temporarily relocating a trash container


A magnetic recording and reproducing apparatus such as a disk drive has a phase locked loop circuit which is less susceptible to an effect of noise of a power supply and ground and reduces a clock jitter. The magnetic recording and reproducing apparatus is compatible to a constant density recording system without increasing a circuit scale and a power consumption and with a small number of IC pins. The phase locked loop circuit of the magnetic recording and reproducing apparatus is provided with two D/A converter circuits to drive a loop filter. It is also provided with a circuit for distributing a reference potential of a voltage controlled oscillator (VCO) and a center frequency of the VCO, a gain of the VCO and a current gain of the D/A converter circuit are changed in linked relation. A reference voltage source is provided such that a center point or one end of the loop filter is connected to the reference voltage eliminating the ground connection.

The present invention relates to a magnetic recording and reproducing apparatus, and more particularly to a phase locked loop circuit for generating a reproducing clock to read and reproduce data from a recording medium or generating a write clock for recording data.
A magnetic recording and reproducing apparatus, as shown in FIG. 9, generally comprises a magnetic recording medium 101 such as a magnetic disk, a magnetic head 118, a read/write (R/W) amplifier 102, a read signal processing circuit 103, a write signal processing circuit 104, a controller 105, a microprocessor or microcomputer 106, a servo control unit 107 and an interface unit (I/F) 108.
The read and write signal processing circuits may be implemented in various ways. As an example, in a partial response maximum likelihood (PRML) system, the read signal processing circuit comprises an AGC circuit 111, an analog-to-digital (A/D) converter circuit 112, a partial response (PR) equalizer circuit 113, a Viterbi encoder circuit 115, a demodulator circuit 116 and a phase locked loop (PLL) circuit 901.
The recording and reproducing of data in the magnetic recording apparatus are explained.
Recording data sent from a host to record it in the magnetic recording and reproducing apparatus is sent to the write signal processing circuit 104 through the I/F 108 and the controller 105, encoded to a recording code which fits to the recording medium and then written into the recording medium 101 by driving the magnetic head 118.
The data read from the magnetic recording medium 101 by the magnetic head 118 and the R/W amplifier 102 is applied to the read signal processing circuit 103, adjusted to a proper signal amplitude by the AGC circuit 111, and then converted from the analog signal to a digital signal by the A/D converter circuit 112 and it is equalized to exhibit a characteristic of a partial response inter-code interference between classes by the PR equalizer circuit 113. Then, it is decoded by the Viterbi detector circuit 115 and decoded to the original data from the recording code by the decoder circuit 116. The decoded data is sent to the host through the controller 105 and the I/F 108.
The positioning of the magnetic head 118 and the rotation of the magnetic recording medium 101 are controlled by the servo control unit 107 and the microcomputer 106. In a data surface servo system, a portion of the read data forms servo data and a servo data signal alll is outputted from the read signal processing circuit 103 and it is used to control the positioning of the magnetic head 118.
The phase locked loop circuit 901 generates a sampling clock a106 of the A/D converter 112 and comprises a phase detection circuit 921, a digital-to-analog (D/A) converter circuit 922, a loop filter 923 and a voltage controlled oscillator (VCO) 924.
The phase detection circuit 921 detects a phase error of the sampling timing from the output signal a101 of the PR equalizer circuit 113 and outputs control data a902. The D/A converter circuit 922 outputs an analog current a903 corresponding to the digital control data a902, and it is integrated and filtered by a loop filter a923 to produce an input control voltage to the VCO 924. In this manner, the VCO 924 is controlled to synchronize the sampling clock a106.
The electronic circuits shown in FIG. 9 including the phase locked loop circuit 901 are integrated in one chip and the loop filter 923 is an off-chip element. A white circle (.smallcircle.) of the loop filter 923 represents off-chip pins. In FIG. 9, it indicates that one pin is required for the loop filter 923.
On the other hand, in the magnetic disk drive, a constant density recording system is primarily used to improve the recording capacity and means to modify the characteristic of the phase locked loop circuit 901 accordingly is required. In FIG. 9, the microcomputer 106 performs the control and produces control signals s101 and s102.
The constant density recording system is disclosed in JP-A-3-205920 (hereinafter referred to as a prior art reference 1) and IEEE 1993 CICC article "A 3-5.5V CMOS 32 Mb/s Fully Integrated Read Channel for Disk Drives (hereinafter referred to as a prior art reference 2).
In the prior art reference 1, a circuit for switching a loop filter 1003 of a phase locked loop circuit 901 as shown in FIG. 10 is used as the means to cope with the constant density recording system.
On the other hand, in the prior art reference 2, a loop 1105 is formed into a full differential type as shown in FIG. 11 and it is driven by four D/A converter circuits 1101 1104 (which may be charge pumping circuits in the peak detection type signal processing). Inputs to the VCO 1106 are differential inputs and connected to the opposite ends of the loop filter 1105. In this system, current gains of the D/A converter circuits 1101.about.1104 may be changed to control a loop gain and an attenuation factor of the phase locked loop circuit 901.
In the magnetic disk drive, the effort to increase a data transfer rate has been attempted for those years and the clock frequency has been increased to 100 MHz, for example. As a result, a specification to a timing margin is severe and the phase locked loop circuit has to suppress a clock jitter as much as possible. However, as the processing speed of the circuit increases, noises of a power supply and ground (GND) of a circuit board of the disk drive tend to increase more and more and this causes the increase of the clock jitter. Particularly, in a small size magnetic disk drive of less than 2.5 inches, since a power is supplied from the system and not from a regulated power supply, the noise immunity of the power supply line is weak and the low impedance of the circuit board wiring is not sufficient to cope therewith. Thus, countermeasure by the circuit configuration is needed.
As for the GND noise, a potential difference between GND in the IC and GND of the circuit board of the disk drive should be noticed. As described above, the electronic circuits are integrated and the respective circuits operate with reference to the GND potential of the IC. Where a noise is included in the GND of the circuit board of the disk drive, the noise may be introduced into the IC through the off-chip element connected to the GND of the circuit board.
It is therefore an important problem to reduce the logic jitter for the noises of the power supply and GND of the circuit board which are more and more becoming prominent as the transfer rate and the miniaturization of the disk drive are increased.
For the electronic circuit including the read signal processing circuit 103 and the write signal processing circuit 104, the user request to reduce the cost and the power consumption is strong. In order to attain it, it is an important problem to reduce the circuit scale of the respective circuits as much as possible to reduce the power consumption, enhance the integration and suppress the number of pins as small as possible to allow the use of an inexpensive IC package.
As to the constant density recording system, the following problem is also encountered.
In the prior art reference 1, as shown in FIG. 10, one end of the loop filter 1003 is connected to the GND. As a result, an AC potential difference between the GND and the reference potential in the VCO appears as a noise which is introduced into the input signal to the VCO to cause the clock jitter. Further, as the precision of the attenuation factor is increased, the number of the off-chip resistors required increases more and more and the number of pins increases.
On the other hand, in the prior art reference 2, as shown in FIG. 11, the loop filter 1105 is of full differential type which is resistive to the GND and power supply noises. However, in this prior art system, four D/A converter circuits are necessary and the circuit scale and the power consumption increase.

Data recording and reproducing apparatus and phase locked loop circuit for use therein including D/A converters acting as charge pumps and a reference voltage source


The laser processing machine includes a beam oscillation mechanism that oscillates a beam spot on a surface of a sheet metal. The control device controls the beam oscillation mechanism so as to oscillate the beam spot with an oscillation component in a direction orthogonal to a cutting direction of the sheet metal in a non-holding region, in which a holding portion of the conveyance apparatus for conveying a product is not held, when cutting the product from the sheet metal by irradiating the sheet metal with the laser beam. The non-holding region is at least a part of a periphery of a protrusion portion of the product, or at least a part of a periphery of a recess forming region in which a recess of the product is formed.

Laser processing machines have been widely used to cut a sheet metal with a laser beam emitted from a laser oscillator, and to manufacture a product having a predetermined shape. The product cut by the laser processing machine may be conveyed by a conveyance apparatus. The conveyance apparatus conveys the products suck by a suction pad (see Patent Literature 1).

Laser processing machine and laser processing method


A receiver in an audio coding system receives a signal conveying frequency subband signals representing an audio signal. The subband signals are examined to assess one or more characteristics of the audio signal including temporal shape. Spectral components are synthesized having the one or more assessed characteristics, integrated with the subband signals and passed through a synthesis filterbank to generate an output signal.

Audio coding systems are used to encode an audio signal into an encoded signal that is suitable for transmission or storage, and then subsequently receive or retrieve the encoded signal and decode it to obtain a version of the original audio signal for playback. Perceptual audio coding systems attempt to encode an audio signal into an encoded signal that has lower information capacity requirements than the original audio signal, and then subsequently decode the encoded signal to provide an output that is perceptually indistinguishable from the original audio signal. One example of a perceptual audio coding system is described in the Advanced Television Systems Committee (ATSC) A/52A document entitled "Revision A to Digital Audio Compression (AC-3) Standard" published Aug. 20, 2001, which is referred to as Dolby Digital. Another example is described in Bosi et al., "ISO/IEC MPEG-2 Advanced Audio Coding." J. AES, vol. 45, no. 10, October 1997, pp. 789-814, which is referred to as Advanced Audio Coding (AAC). In these two coding systems, as well as in many other perceptual coding systems, a split-band transmitter applies an analysis filterbank to an audio signal to obtain spectral components that are arranged in groups or frequency bands, and encodes the spectral components according to psychoacoustic principles to generate an encoded signal. The band widths typically vary and are usually commensurate with widths of the so called critical bands of the human auditory system. A complementary split-band receiver receives decodes the encoded signal to recover spectral components and applies a synthesis filterbank to the decoded spectral components to obtain a replica of the original audio signal.
Perceptual coding systems can be used to reduce the information capacity requirements of an audio signal while preserving a subjective or perceived measure of audio quality so that an encoded representation of the audio signal can be conveyed through a communication channel using less bandwidth or stored on a recording medium using less space. Information capacity requirements are reduced by quantizing the spectral components. Quantization injects noise into the quantized signal, but perceptual audio coding systems generally use psychoacoustic models in an attempt to control the amplitude of quantization noise so that it is masked or rendered inaudible by spectral components in the signal.
Traditional perceptual coding techniques work reasonably well in audio coding systems that are allowed to transmit or record encoded signals having medium to high bit rates, but these techniques by themselves do not provide very good audio quality when the encoded signals are constrained to low bit rates. Other techniques have been used in conjunction with perceptual coding techniques in an attempt to provide high quality signals at very low bit rates.
One technique called "High-Frequency Regeneration" (HFR) is described in U.S. patent application publication number 2003-0187,663 A1, entitled "Broadband Frequency Translation for High Frequency Regeneration" by Truman, et al., published Oct. 2, 2003, which is incorporated herein by reference in its entirety. In an audio coding system that uses HFR, a transmitter excludes high-frequency components from the encoded signal and a receiver regenerates or synthesizes noise-like substitute components for the missing high-frequency components. The resulting signal provided at the output of the receiver generally is not perceptually identical to the original signal provided at the input to the transmitter but sophisticated regeneration techniques can provide an output signal that is a fairly good approximation of the original input signal having a much higher perceived quality that would otherwise be possible at low bit rates. In this context, high quality usually means a wide bandwidth and a low level of perceived noise.
Another synthesis technique called "Spectral Hole Filling" (SHF) is described in U.S. patent application publication number 2003-0233234 A1 entitled "Improved Audio Coding System Using Spectral Hole Filling" by Truman, et al., published Dec. 18, 2003, which is incorporated herein by reference in its entirety. According to this technique, a transmitter quantizes and encodes spectral components of an input signal in such a manner that bands of spectral components are omitted from the encoded signal. The bands of missing spectral components are referred to as spectral holes. A receiver synthesizes spectral components to fill the spectral holes. The SHF technique generally does not provide an output signal that is perceptually identical to the original input signal but it can improve the perceived quality of the output signal in systems that are constrained to operate with low bit rate encoded signals.
Techniques like HFR and SHF can provide an advantage in many situations but they do not work well in all situations. One situation that is particularly troublesome arises when an audio signal having a rapidly changing amplitude is encoded by a system that uses block transforms to implement the analysis and synthesis filterbanks. In this situation, audible noise-like components can be smeared across a period of time that corresponds to a transform block.
One technique that can be used to reduce the audible effects of time-smeared noise is to decrease the block length of the analysis and synthesis transforms for intervals of the input signal that are highly non-stationary. This technique works well in audio coding systems that are allowed to transmit or record encoded signals having medium to high bit rates, but it does not work as well in lower bit rate systems because the use of shorter blocks reduces the coding gain achieved by the transform.
In another technique, a transmitter modifies the input signal so that rapid changes in amplitude are removed or reduced prior to application of the analysis transform. The receiver reverses the effects of the modifications after application of the synthesis transform. Unfortunately, this technique obscures the true spectral characteristics of the input signal, thereby distorting information needed for effective perceptual coding, and because the transmitter must use part of the transmitted signal to convey parameters that the receiver needs to reverse the effects of the modifications.
In a third technique known as temporal noise shaping, a transmitter applies a prediction filter to the spectral components obtained from the analysis filterbank, conveys prediction errors and the predictive filter coefficients in the transmitted signal, and the receiver applies an inverse prediction filter to the prediction errors to recover the spectral components. This technique is undesirable in low bit rate systems because of the signal overhead needed to convey the predictive filter coefficients.

This patent is subject to a terminal disclaimer.

Audio coding system using temporal shape of a decoded signal to adapt synthesized spectral components

Dolby Laboratories Licensing Corporation


A portable model and methods for simulating water treatment processes are presented. Included are a body of untreated drinking water, simulated sources of wastewater, and simulated drinking and wastewater treatment plants. In the simulated drinking water treatment plant, water is treated and stored for distribution though a simulated pipeline system. In the simulated wastewater treatment plant, simulated wastewater is filtered, settled, clarified, disinfected and discharged. The simulated wastewater may be transferred to the simulated wastewater treatment plant through a simulated sewage pipeline network. Simulated biosolids as a result of the wastewater treatment process may be stored or applied to land. The model may also simulate a storm drain system that diverts storm water to a water source or to the wastewater treatment plant. The materials used to simulate the various aspects and components are preferably non-toxic, non-poisonous and biodegradable in order to facilitate use with children and clean up.

1. Field of the Invention
The present invention relates generally to simulating and demonstrating water treatment. More particularly, the present invention involves simulation and demonstration of drinking water treatment and wastewater treatment and disposal.
2. Description of Related Art
The treatment of water, and in particular wastewater, generally involves chemical and biological processes which treat and remove physical, chemical, and biological contaminants. The results from these processes produce a treated and clean waste stream for discharge or recycling for environmental purposes, and solid waste (known as sludge) that can also be disposed or recycled.
The treatment of wastewater may occur on-site at the source using, for example, septic tanks or onsite treatment plants. Alternatively, the wastewater may be collected and transported via a pipeline network to a municipal treatment plant. Typically, the treatment of wastewater begins with the removal of solids from the waste stream. Next, a conversion process converts dissolved biological matter into a solid biological mass using water-borne bacteria. Once the biological solids are separated and removed, the treated water may undergo a chemical disinfection. This resultant treated water may subsequently be discharged or recycled back into the environment (e.g., bodies of water, wetlands, green ways, and the like). The segregated biological solids can receive additional treatment and neutralization prior to proper disposal or recycled.
Similarly, the treatment of raw water (e.g., groundwater, lake water, reservoirs, rain water, etc.) to produce drinking water also includes the removal of chemical and biological contaminants. For example, water pollutant sources such as chemicals, metal, bacteria, algae, viruses, fungi, and the like may be removed through various stages using filters, coagulation, flocculation, and membranes. Next, chemical processes may be performed to adjust the pH value, remove any taste or smell, and disinfect. After the treatment processes, the drinking water is stored and/or delivered to residential, commercial, and industrial areas.
Water treatment models are useful to demonstrate graphically sources of drinking water, treatment of water (e.g., drinking water and wastewater), the manipulation of water through pipeline networks, and the disposal of treated wastewater. The models are useful either as a simulation of water treatment processes, or as a teaching tool to create awareness and understanding of water treatment techniques, particularly in schools and other teaching environments. Prior water treatment models have not been effective in graphically showing sources of water, the treatment of wastewater and drinking water, and the disposal of treated wastewater. In addition, prior water treatment models have been cumbersome, unwieldy, and not portable.

Model and method for simulating water treatment


Unsaturated polyester resin-based compositions that are modified for unexpected improvement in uniform, low optical distortion and/or improved tint speed by the addition of one or more additives selected from an allylic ester and/or an acrylic monomer, together with an exotherm depressant, making the modified polyester resin-based composition commercially viable for casting ophthalmic lenses. The additive(s) and exotherm depressant are useful to modify the polyester for sufficient enhancement of optical distortion and/or tint speed such that any unsaturated polyester resin, capable of producing a clear, low color casting, will be improved sufficiently to provide a composition having the required properties for an ophthalmic lens.

Plastic materials have been used for the manufacture of ophthalmic lenses for many years. Plastics offer advantages to the patient over glass, most noticeably in their lower densities, allowing for a lighter lens, and greater impact strength. Conversely, plastic lenses can exhibit disadvantages: they tend to scratch more easily, have higher levels of chromatic aberration (lower ABBE values), and may distort at higher temperature processing conditions, due to lower glass transition (Tg) temperatures, resulting in "warped" lenses, or lenses with high levels of optical distortion. Additionally, plastic lenses usually have lower index of refraction values when compared to glass, which tends to require lenses of increased thickness and reduced cosmetic appeal. The standard "CR-39" type lens, made from diethylene glycol bis(allyl carbonate), has an index of refraction of 1.498.
Advances in technology have allowed improvements in plastic lens performance. Coatings have been developed which impart improved scratch resistance. Some plastics have relatively high ABBE values which are adequate for minimizing the effects of chromatic aberration. Improvements in machining and optical lens processing equipment and processes have permitted the use of materials having lower glass transition temperatures. Plastics with higher indices of refraction, and physical lens design improvements, have helped improve the cosmetic appeal of plastic lenses.
While these improvements have helped the plastic lens gain acceptance in the marketplace, to a point where plastic lenses constitute a majority of lens eyewear in the U.S., increasing expectations for performance have dictated that good ophthalmic lenses have the following characteristics:
Clarity and Color
Lenses which are "hazy" are obviously unacceptable to the patient. Color is also of concern both from the standpoint of having a "water-white" quality for best cosmetic appeal when the lens is first purchased, as well as maintenance of that color over time, e.g., being resistant to the effects of sun light, which over time can cause the lens to turn yellow.
Optical Distortion
Lack of optical distortion requires a material having a relatively high ABBE number such that chromatic aberration is minimized; and, more importantly, a material having excellent uniformity in composition such that the occurrence of visible "waves" is minimized.
Rapidly Tintability
Many ophthalmic lenses are manufactured in semi-finished form and shipped to optical laboratories where the prescription is "ground in". With ever increasing emphasis on short optical lab turn-around times, e.g., 1 hour service, the ability of the lens material to rapidly accept fashion tints is important. In the case of semi-finished lens products, the front surface of the lens may have a scratch resistant coating which does not accept tint. Thus, the only route for tinting to occur may be the parent lens material on the back surface. This material must be tintable.
High Index of Refraction and Low Density
The higher the index of refraction, the thinner the finished lens will be for a given design. This higher index, especially when combined with a relatively low density, will allow for the manufacture of "thinner and lighter" lens products.
Over the past several years, plastic ophthalmic lenses have been fabricated from a variety of materials including polycarbonate and polymethylmethacrylate, as well as polymerized allylic compounds, epoxies, and urethanes. The most common plastic ophthalmic lens, however, is made from diethylene glycol bis(allyl carbonate) often referred to as "CR-39" (a specific product manufactured by PPG Industries). As previously mentioned, this material has a refractive index of 1.498. It is easily processed in optical laboratories, is able to be manufactured with low optical distortion and is readily tinted by various commercially available tinting dyes.
The use of polyester materials to produce ophthalmic lenses has been previously disclosed in various U.S. patents. Examples of such disclosures are U.S. Pat. Nos. 3,391,224 and 3,513,224. U.S. Pat. No. 3,391,224 discloses a composition in which a polyester is combined with from 5 to 20 weight percent methyl methacrylate and less than 5 weight percent styrene to produce a thermosetting product which can be used to produce an ophthalmic lens. U.S. Pat. No. 3,513,224 discloses a composition in which 70 to 75 weight percent of a specific unsaturated polyester formed from the reaction of fumaric acid with triethylene glycol and 2,2-dimethyl-1,3-propanediol (otherwise known as neopentyl glycol) is combined with about 12 to 18 weight percent styrene and 8 to 12 weight percent ethylene glycol dimethacrylate. The styrene raises the index of refraction to approximately 1.52, and the ethylene glycol dimethacrylate reduces brittleness of the polymer.
A number of commercially available unsaturated polyester resins has been developed which are clear when cast and have a refractive index of approximately 1.56 (the high index being primarily attributable to the use of styrene as a cross-linking diluent monomer at a level of approximately 30 to 45 weight percent). The densities of the various polyester systems are also quite low (on the order of 1.25 grams/cc). These properties are superior to CR-39 (index of 1.498 and density of 1.32 grams/cc) with regard to the potential to make "thinner and lighter" lenses.
Polymerization of the polyester resin system can be carried out in a number of ways. Quite common is the use of a system promoted with a material such as cobalt octoate or cobalt naphthenate. When used with methyl ethyl ketone peroxide, the system can be cured near room temperature. Other free radical polymerization techniques also can be used, including thermal curing using peroxides or diazo compounds, as well as photoinitiated curing using compounds selected from the following classes of photoinitiators: benzoin ethers, benzophenones, thioxanthones, ketals, acetophenones, and phosphine oxides.
Polyester resins can be manufactured using different compositions to achieve a wide variety of physical properties (hard, soft, rigid, flexible, and the like). Typical commercial polyesters include those made from a variety of glycols and acids. Common glycols used in alkyd polyester synthesis include: ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, and the like. Common acids used include: phthalic anhydride, isophthalic acid, adipic acid, and the like, used in conjunction with maleic anhydride and/or fumaric acid to provide unsaturation for cross-linking, usually with styrene or other diluent monomers.
Resins made using phthalic anhydride are commonly called "ortho resins"; those made with isophthalic acid are commonly referred to as "iso resins". With respect to properties desirable for making ophthalmic lenses, typical iso resins which have good scratch resistance are generally quite slow to tint. Typical ortho resins, on the other hand, are generally more scratch-prone, but tint more readily. All of the unsaturated polyester resins have a propensity to polymerize somewhat non-uniformly causing internal optical distortion or visible "waves".
As previously mentioned, styrene is commonly used as a cross-linking diluent monomer with unsaturated polyester compositions. As the portion of styrene is increased, the index of refraction also increases. However, the presence of higher concentrations of styrene also tends to cause a higher degree of exotherm within the polymerizing composition leading to the formation of optical distortion within the lens. Improving optical uniformity (lowering optical distortion) and increasing tint speed in an unsaturated polyester resin-based ophthalmic lens composition, while maintaining a high index of refraction and color, therefore, is a formidable task.

Polyester resin-based high index ophthalmic lenses having improved optical uniformity and/or tintability


Disclosed are a method and a device for providing content-related information of a multimedia service. The method comprises the steps of: transmitting a signaling message comprising schedule information and delivery type information of a media content to be serviced; receiving, from at least one terminal, at least one report message comprising identification information and transfer type information of the media content; and transmitting an updated signaling message on the basis of the at least one report message received from the at least one terminal receiving the media content.

According to explosive growth of wired and wireless internets, various types of internet televisions (TVs) will be meaningful part of everyday life in the future. It is expected that mobile video traffic will account for considerable amount of total mobile data traffic in the future according to rapid increase of mobile data traffic. In this case, mobile data traffic is also increased significantly at certain times, a problem that watch through a smart phone is not smoothly provided may occur.
As a demand for a real-time live broadcasting service through mobile terminals increases, a service provider needs to develop a related supplementary service, and there is a need for a scheme of effectively managing mobile traffic at the same time. An enhanced Multimedia Broadcast and Multicast Service (eMBMS) as a technology for Long Term Evolution (LTE) broadcast has been proposed as one of solutions for this. The LTE broadcast may use an LTE frequency as it is and adopt a multicast transmission scheme to decrease traffic load, and may support various new services such as an area-based advertisement, a content business, and/or the like as well as a mobile broadcasting. Like this, a ground wave broadcasting, and/or the like as well as the mobile broadcasting transmits a main content and various supplementary information through various transmission channels such as a broadband channel, a Wifi channel, and/or the like as well as an existing ground wave channel, so various new services may be provided. However, at this time, it is also important to decrease traffic load.
An existing streaming scheme which transmits a media content using a hyper text transfer protocol (HTTP) generates media resource identification information which provides a location of a media source along with meta data of the media content upon generating the media content. For example, when a media content of 10 minutes is converted to an HTTP-based file format for streaming through an internet, media resource identification information indicating a content server which provides the media content of 10 minutes is included in meta data of the media content in a form of a uniform resource locator (URL), and the meta data is transmitted to a receiver. After receiving the meta data, the receiver requests transmission of a media content for a streaming service which a user wants from an HTTP-based content server based on the media resource identification information (e.g., a URL) stored at the meta data.
This existing streaming scheme has various problems in an actual real-time streaming environment. For example, media resource identification information (i.e., a URL) used in an HTTP scheme does not indicate an actual address (e.g., an IP address) of a content server, so a receiver needs to transmit request for searching the actual address of the content server to a domain name system (DNS) server in order to access the content server, and delay occurs due to this.
Further, in an existing streaming service, an address of a content server is maintained for a determined file duration, real-time update on media resource identification information according to dynamic channel change is impossible, so it is difficult for a receiver to adapt to dynamic channel change within one program while receiving a corresponding streaming service.
Finally, it needs to detect the number of users who use each media content channel to perform resource allocation suitable for the number of users for effective network management when a service of a multicast scheme is provided, however, it is difficult to detect the number of users who access a corresponding channel to use a service in an existing streaming service.

Method and device for providing content-related information of multimedia service


A cushion standard shield system to remove and deflect residue, dirt, debris, and soil from a cushion bearing hanger, or cushion standard, portion of a disk gang type agricultural implement is provided. The cushion standard shield system includes a mounting bracket supported by a common axle which carries multiple disk blades of the disk gang. A blade assembly is mounted to an upright portion of the mounting bracket, and is positioned generally behind and above the axle, behind the cushion standard. The blade assembly includes one or more plate member with arcuate lateral edges. The radii of the arcuate lateral edges correspond closely in magnitude to the radii of the concave and convex surfaces of the disk blades. The plate members are laterally adjustable with respect to each other, whereby the width dimension of blade assembly is variable to accommodate different axial spacing widths of adjacent disk blades.

Agricultural soil preparation equipment typically includes a disk configuration, commonly referred to as a disk or disk harrow, to be used for breaking up and smoothing the surface of cultivated fields in preparation for planting. In addition to planting preparation, disk harrows are increasing in popularity as a necessary implement for crop residue management. Modem plant varieties produce relatively higher yields, are physically and structurally tougher, and leave behind relatively more residue than previously. The disk harrow is usually drawn by a tractor or other source of motor power; multiple disk gangs are often employed in a single disk harrow. In disk harrows which incorporate multiple disk gangs, a forward disk gang initially cuts residue or breaks up lumps and clods, and a rear disk gang reduces the residue of dirt fragments to a still smaller size and smoothes the ground. Accordingly, the residue is reduced in size and mixed with the dirt or soil, which increases its decomposition or breakdown rate.
Typical disk harrows include a main frame with several disk gang assemblies suspended therefrom. The disk gangs are generally mounted at an angle with respect to the forward direction of travel. Each of the disk gangs includes a plurality of equally spaced disk blades mounted on an axle for rotation about a common axis. The axle is supported by a series of C-shaped spring elements, i.e. cushion standards, configured to allow the disk gangs to flex with the contour of the landscape as the agricultural implement is drawn by the tow vehicle. In addition to providing articulation to accommodate terrain variations, the cushion standards serve a protective function for the implement. In particular, the cushion standards absorb energy associated with various shock loads, impacts, collisions and other harsh occurrences, which occur, e.g., when the implement encounters rocks or other obstructions during use.
In wet weather or in heavy, sticky soil conditions, earth tends to cling to the disk blades. In order to smooth the ground properly, it is desirable that this earth be removed frequently or even continuously. Otherwise, the accumulation of soil and residue adhering to the disks can adversely affect disk operation. To eliminate the accumulation of soil and residue, scraper devices have been developed to keep the surfaces of the disks, near their circumferences, clear of the soil and residue.
U.S. Pat. No. 4,127,179 discloses a scraper mechanism for a disk gang harrow. The scraper mechanism includes a scraper blade supported from a mounting bracket fixedly attached to a toolbar of an agricultural implement to be towed. The scraper blade is generally aligned in a downward direction so as to bias against the disk blade. An axle of the disk gang passes through bearing assemblies which are suspended and supported by bearing-support arms that extend down from the toolbar. The scraper blades are rigidly supported to the toolbar and likewise tend to bounce in relation to the disk gang. Also, the vertically aligned scraper blades tend to yield and break from miscellaneous forces (e.g., contact with debris flow caused by cutting action of the disk blade) associated with operation in the field. When the mounting bracket or fastener breaks, the scraper arm and attached scraper blade are usually lost in the field. Also, soil and residue flow tend to be carried from the rear of the rotating blades to up and forward over the top of the disk gang spools and be trapped behind the disk gang cushion standard and on the top of the gang bearing assembly. When this happens, the soil and residue mixture can be compacted between the disk blades and the cushion standard and prevent the proper operation of the disk gang.
As shown and described in copending and commonly assigned U.S. application Ser. No. 11/096,400, filed on Apr. 01, 2005 and published on Oct. 12, 2006 as U.S. publication number 2006/0225901, other, more desirable, disk scraping configurations have been developed. The scraper system includes scraper blades which are mounted to a bracket which is, in turn, mounted to the disk gang axle. Deflector plates are fixedly mounted at the cushion standards.


Disclosed is a circuit to provide protection from an over voltage signal. The circuit protects against load dumps or positive transients applied to any electronic unit. The circuit isolates the protected circuitry from the transient voltage by two ways. The circuit limits the current flow and clamping the voltage using a small package zener diode. Additionally, the circuit causes a specific voltage drop between the applied transient and the protected circuit.

The present invention relates to a high voltage protection circuit as it is used in electronic systems that may be exposed to sudden high voltage spikes. The circuit may be used to protect electronic devices that operate on a relative low voltage but are subject to sudden peak voltages. For example, in an electronic brake system (EBS) of a vehicle, circuitry is designed to operate at or below 40 volts. However, when a load dump or positive transient occurs, the voltage applied to components may greatly exceed the maximum voltage causing failure.
One circuit arrangement for overload protection is shown by U.S. Pat. No. 6,556,401 (Loewen et al.). The overload protection circuit includes a third circuit path. The third circuit path is between the first circuit path and a connection of a field-effect transistor which is coupled to the second input connection, and includes the source/drain path of a second field-effect transistor. The third circuit path is completed if an overload occurs between the first and the second input connection. The gate connection of a field-effect transistor is connected to a potential in the first circuit path between the first input connection. The first output connection, and the gate connection of the second field-effect transistor is connected to a potential in the second circuit path between the second output connection and that connection of the first field-effect transistor which is coupled to the second output connection. However, this system is ineffective in protecting against spikes caused by a load dump or positive transient occurrence.
A second circuit arrangement for overload protection is shown by U.S. Pat. No. 6,411,481 (Seubert). A switch and load are connected in series between the terminals of a voltage source. The switch is triggered to release the current flow in the load if the voltage exceeds a threshold value. This device suffers from needing extra switches causing extra costs and size to the system.
It is therefore an object of the current invention to suggest a circuit design that protects from large voltage spikes, yet is inexpensive to make and small in size. It is a further object of the invention to provide adequate protection with minimal additional components that can be used with current production electronic circuits.


The invention relates to a tourbillon mechanism comprising at least one platform, a balance arranged on the face of the platform(s), an escapement mechanism being arranged on the other face.

The invention relates to a tourbillon, or a tourbillon module, as well as a clockwork with a tourbillon mechanism, according to the preamble of the independent patent claims.
So-called "tourbillon" clockworks are known from the state of the art, with which the balance is arranged on a rotary stand. In contrast to a conventional clockwork, with such a clockwork, a rotational movement about the same balance axis or about a rotation axis parallel to the balance axis is superimposed on the pendulum movement of the balance, with the aim of statistically compensating inaccuracies which are dependent on the position.
Conventional tourbillon designs are classed as flying, semi-flying or conventional. The differences of the individual manners of design are based on the arrangement of the bearings which serve for the mounting of the rotary stand and the balance. A good overview with regard to the different tourbillons may be deduced from the book "Das Tourbillon" by Reinhard Meis, 1993, Callway publishing house, Munich.
With a so-called flying tourbillon design, the balance and the escapement mechanism (as a rule lever escapement) is mounted on the rotary stand. With non-flying or semi-flying tourbillons, the arbor (axle) of the balance (balance arbor), completely or at least on one side, is mounted outside the rotary stand. With all known tourbillon designs, the balance and the escapement mechanism are arranged on the same side of the platform of the rotary stand, which leads to a one-sided concentration of weight, having a certain negative influence on the clockwork accuracy of the watch/clock. A further disadvantage lies in the fact that due to the construction manner which is often convoluted, the assembly and the maintenance of the tourbillon are difficult to accomplish. In particular with flying tourbillons, the balance arbor has a limited length, which has a negative effect on the loading of the bearings.


An ophthalmoscope includes a housing (12) in which there are arranged an observing unit and a light source between which there are/is arranged a diaphragm and/or a filter device that can be set via a swivel lever device (16, 17) mounted outside on the housing (12). The swivel lever device (16, 17) can be locked in respective latch stages by a locking device (41).

1. Field of the Invention
The invention relates to an ophthalmoscope having a housing in which there are arranged an observing unit and an illuminating unit between which there are/is arranged diaphragm means and/or filter means that can be set via a swivel lever means mounted outside on the housing.
2. Description of the Background Art
U.S. Pat. No. 4,684,227 discloses a generic binocular ophthalmoscope in whose lower housing part an observing unit is arranged by means of which an examiner can examine through a patient's pupil. An illuminating unit with a light source is accommodated in the upper housing part. An adjustable diaphragm is arranged between the light source and the observing unit. Also provided is a filter means by means of which optical filters can be moved into the illuminating path between the illuminating source and the observing unit. For the purpose of setting the diaphragm and the optical filters, there is respectively mounted on the side of the housing swivel lever means that comprises a rotary element, arranged in a bearing opening, on the outside of which a swivel lever is fastened. The swivel levers are kinematically connected to a mechanism for setting the diaphragm and/or the optical filters.
The swivel lever means are mounted in a freely rotatable fashion in the bearing openings. As a rule, ophthalmoscopes are used by a single investigator who prefers a specific setting of the diaphragms and/or the optical filters. Other settings are carried out only rarely. Since the swivel lever means are supported in a freely rotatable fashion, the diaphragm or the optical filters are, however, displaced when the swivel levers are lightly touched, and this quickly comes about during improper handling. It is then necessary to reset the diaphragm and filters.


Oxidation protection of a titanium-based alloy is provided with improved fatigue properties by a titanium aluminide coating of between 2 to 12 microns by diffusing the Al into the Ti at a temperature below the melting point of the Al. The coating is gas deposited and protects the titanium-based alloys from oxidation at high temperature utilization.

The present invention relates to heat exchangers. More specifically, the present invention relates to oxidation protection of titanium-based heat exchangers, with improved fatigue properties.
Certain heat exchangers used in aircraft environmental control systems are exposed to temperatures exceeding 400° C. These heat exchangers are typically made of stainless steel or nickel based alloys such as Inconnel, which can withstand the high temperatures.
It would be desirable to use titanium heat exchangers instead of stainless steel heat exchangers. Titanium and its alloys have a lightweight and can provide a weight reduction of up to 40% over comparable stainless steel heat exchangers. The weight reduction results in better fuel efficiency and lower aircraft operating costs.
However, titanium is not used for high temperature heat exchanger applications because the titanium exhibits a propensity to rapidly oxidize, (over a couple of hours), at the required operating temperatures. Oxidation of titanium results in a reduction in ductility and then strength, and a deterioration in structural integrity. Repeated thermal cycling at temperatures between ambient temperature and around 400° C. (and higher) causes the titanium to crack. Cross contamination of fluids can occur and lead to life-threatening conditions.
Accordingly, it has been proposed to provide an oxidation protective coating to the exposed titanium-based surfaces of the heat exchanger. The coating may be a titanium aluminide coating. The coatings and thermal cycles are compatible with the titanium alloy and also the brazes used to join the Ti. It also provides protection to the braze, which can be more prone to oxidation than the Ti. Oxidation of the braze would enbrittel the joint and lead to oxidation of the Ti. Not only does the titanium aluminide provide oxidation protection, but it is able to withstand the different thermal stresses due to thermal cycling set up by either titanium or a braze clad titanium, because of their good bonding to the base titanium and braze plus their high strength. The braze and titanium have different coefficients of thermal expansion so locally at the junction between braze clad and titanium the coating may be subject to high strains and stresses. In addition, the coatings do not reduce the heat exchanger efficiency by reducing the gas flow through the passageways. Neither do they reduce the heat transfer though the titanium; i.e. they do not thermally insulate the titanium that they protect from oxidation.
Moreover, the coatings maintain adequate strength and ductility in the titanium, which allows the heat exchanger to handle structural forces occurring in high temperature heat transfer applications.
In many vehicles and especially in an aircraft there are high pressures and temperature cycling and vibrations from the surrounding environment (e.g., the aircraft engine on which the heat exchanger is attached). The protective coating must therefore also maintain adequate fatigue properties in the material it is protecting. It is however well known that most coatings reduce the fatigue life of material they are protecting. For instance, anodizing of aluminum is a well-known method of protecting aluminum, but it also reduces the fatigue life of the aluminum. This is usually referred to as the fatigue debit. For most coatings there is a need and desire to reduce the magnitude of this fatigue debit and ideally to eliminate it.
The TiAl protective coatings for titanium also have a fatigue debit and as would be expected there is a desire to reduce this debit. Especially as aircraft heat exchangers are usually used in an environment, which is subjected to high fatigue loads, there is a need therefore to improve the fatigue characteristic of the coating and reduce the debit it has on the fatigue properties of the Ti.

Elevated temperature oxidation protection coatings for titanium alloys and methods of preparing the same


A light diffusion control member includes a first light diffusion control layer and a second light diffusion control layer. The first light diffusion control layer and the second light diffusion control layer each has a regular internal structure that includes a plurality of regions having a relatively high refractive index in a region having a relatively low refractive index. The first light diffusion control layer and the second light diffusion control layer are laminated so that an angle between two respective vectors determined based on the regular internal structure in the first light diffusion control layer and the second light diffusion control layer is more than 0° and 90° or less.

Display bodies such as liquid crystal display devices, organic electroluminescence (EL) displays, and electronic paper include those classified into reflective display bodies including reflective layers. In such reflective display bodies, the display surface of a reflective display body is generally illuminated by a light source such as an indoor light or the sun and/or a light source provided on the display surface side of the display body, and light from these light sources is reflected by the reflective layer into reflected light, which enables good visibility of the display.
When using the reflective display body, the positional relationship between the light source and the viewer is usually not fixed due to the use of an external light source. This may result in a problems in that, depending on the position of the light source, insufficient light reaches the viewer to deteriorate the visibility and the entire display body cannot be illuminated brightly. To solve such a problem, it is conceivable to incorporate a light diffusion plate into the display body. However, simply incorporating a general light diffusion plate may lead to another problem in that the diffusivity necessary for good visibility cannot be sufficiently obtained and, if attempting to achieve high diffusion, light loss due to stray light or backscattering occurs to impair the image clarity. From the viewpoint of solving these problems, in the reflective display bodies, it is considered that a light diffusion control layer that can transmit and diffuse the incident light within a predetermined incident angle range in a strong and low light loss state is provided between the surface on the viewer side and the reflective layer (Patent Document 1, for example). The existence of the above light diffusion control layer allows the light reflected from the reflective layer to be moderately diffused, and the deterioration in the visibility depending on the position of the light source can thus be reduced.
It is also considered to stack two or more of the above-described light diffusion control layers. For example, Patent Document 2 discloses a light diffusion control member including two light diffusion control layers. In particular, Patent Document 2 discloses an example of the light diffusion control member in which two light diffusion control layers are laminated so that the directional characteristics of transmitted and diffused light are opposite to each other.

Light diffusion control member and reflective display body


An optical display panel which provides improved viewing contrast for front projection applications, and a method of producing a stacked optical waveguide panel for front projection applications, are disclosed. The optical panel includes a plurality of stacked optical waveguides, wherein each waveguide has a back face and an outlet face at opposing ends of each waveguide, and wherein each waveguide is formed of a core between an opposing pair of cladding layers, and at least one reflector connected to the back face of at least one waveguide, wherein the at least one reflector receives image light incident through at least one waveguide from the outlet face, and wherein the at least one reflector redirects the image light back through the at least one waveguide out of the outlet face. In the preferred embodiment, the outlet face is rendered black by inclusion of black within or between cladding layers. The method includes stacking a plurality of clear strips of plastic, placing a double sided, dark colored adhesive between each strip of plastic, pressing the stack, forming, at two opposite ends of the stack, a back face and an outlet face, and connecting at least one reflector to the back face.

1. Field of the Invention
The present invention is directed generally to a planar optical display, and, more particularly, to a high contrast front projection display panel and a method of making a high contrast front projection display panel.
2. Description of the Background
Video display screens typically use cathode ray tubes (CRTs) for projecting an image onto the outlet face of the screen. A typical screen of this type has a width to height ratio of 4:3 with 525 vertical lines of resolution. An electron beam must be scanned both horizontally and vertically on the screen to form a number of pixels, which collectively form the image. Conventional cathode ray tubes have a practical limit in size and are relatively deep to accommodate the required electron gun. Larger screen televisions are available which typically include various forms of image projection for increasing the screen image size. However, such screens may experience limited viewing angle, limited resolution, decreased brightness, and decreased contrast, particularly in display screens using front projections. This is, in part, due to the use of white screens to allow the screen to reflect the front projection back to the user. Thus, because the screen is white, the darkest black level that can be displayed is "screen white", the color of the screen when the projection is off, due to the fact that black light cannot be projected. Consequently, the projection must be either on, or off, to produce white, or black, respectively. Thus, where black is viewed on a front screen projection system, the viewer is actually seeing the white of the background, i.e the absence of projected light, which the human eye sees as black in the context of the white light projected elsewhere on the background, meaning that the presence of the optical spectrum projected onto the white background forms a "whiter than white" color, which the eye sees as white. This is the reason that a room must be darkened in order for a viewer to see black on a front projection screen.
Optical panels can be created using a plurality of stacked waveguides, and may be rendered black using at least one black cladding layer between transparent cores of the waveguides. The cladding layers disclosed therein have a lower index of refraction than the waveguide cores for effectuating substantial internal reflection of the image light channeled through the cores, and thereby improve contrast, i.e. thereby improve the appearance of black images on a screen. Such optical panel displays have typically been operated in a rear projection mode.
Therefore, the need exists for a display panel that allows for front projection, while also providing the appearance of a black screen to improve viewing contrast and to eliminate the need to dim lights in order to allow a viewer to see black images.

High contrast front projection display panel and a method of making a high contrast front projection display panel


A variety of processes for certifying the reporting of advertising impressions provided via video games are described. These certification processes optionally take advantage of automated techniques for verifying that when advertising data is provided a corresponding advertisement is provided within the video game. In addition, as software patches are often provided for video games, a recommended process for certifying patched software is also described. Reporting data associated with advertising impressions provided from uncertified video games is considered suspect and optionally discarded.

Broadcast television has given rise to many related and ancillary industries. One such industry is the advertising industry. Advertising for television is a specialized industry that relies on past and present data to establish a value for advertisements displayed during a broadcast event. In order to support this advertising model, an entire industry exists to gather and analyse metrics of television viewership.
To this end, audiences are polled relative to their television viewing and statistics relating to viewership are determined. Similarly, each broadcast event such as a television show, television movie, a sporting event, etc., is reviewed to determine the advertisements within those broadcast events. Thus, the actual advertising content and the statistically analysed viewership are independently determined and verified by an organization to determine the metrics used to establish a value for advertisements. These metrics are typically referred to as "audited metrics" as their correctness is asserted by an independent metrics organization that asserts that it has verified the correctness thereof. One such metrics organization is the Nielsen Media Research™, which provides Nielsen® ratings that are, for the most part, audited.
A new medium into which advertising is now being inserted is the medium of video games. As a first generation of in-game advertisements, static product placements—product placements programmed into the game and that remain in the game each time it is played—were used. These first generation advertisements have metrics associated therewith calculated and gathered in a fashion similar to those for television viewership.
Presently, a next generation in game advertisement is being deployed. According thereto, product placements are inserted within video games dynamically such that each time a game is played, different advertisements may appear therein. Unfortunately, existing methods of determining metrics are not suited to function with these next generation in game advertisements. Problematically, the video games are not similar when played—different advertisements may be displayed in each; the video games are not played at a consistent time; and the video games are not played consistently by each player.
It would be advantageous to provide a method of determining metrics for next generation in game advertisements.

Method and system supporting audited reporting of advertising impressions from video games


The present invention provides, inter alia, convergent processes for preparing eptifibatide that involve coupling a 2-6 eptifibatide fragment to an activated cysteinamide residue to form a 2-7 eptifibatide fragment, attaching a mercaptopropionic acid residue to the 2-7 eptifibatide fragment through disulfide bond formation, coupling the peptide intramolecularly, and removing the protecting group, to form eptifibatide. The invention further provides products produced by the described processes, novel compounds that can be used as synthetic intermediates for the preparation of eptifibatide, and novel compounds that are structurally similar to eptifibatide.

Eptifibatide is a highly specific cyclic heptapeptide antagonist of the platelet glycoprotein IIb/IIIa. It is a short-acting parenteral antithrombotic agent that is used during percutaneous coronary interventions for the treatment of unstable angina and as an adjunct to thrombolytic agents for the treatment of acute myocardial infarction. See, for example, Phillips et al., Journal of Biological Chemistry (1993), 268(2), 1066-73; and Scarborough, American Heart Journal (1999), 138(6, Pt. 1), 1093-1104. Eptifibatide is also administered to patients undergoing balloon angioplasty, a procedure for which over 1.0 million people in the U.S. are candidates annually.
Eptifibatide is believed to work by inhibiting platelet aggregation, specifically, by blocking the platelet receptor GP IIb-IIIa. The aggregation of platelets can obstruct blood supply to the heart, causing unstable angina and, possibly, myocardial infarction (heart attack). The effects of eptifibatide are specific to platelets, avoiding interference with other normal cardiovascular processes, and the effects can be reversed when eptifibatide use is discontinued.
Eptifibatide is marketed in the U.S. under the trademark INTEGRILIN®, and is used to treat patients with acute coronary syndrome (unstable angina and non-Q-wave MI), including patients who are to be managed medically and those undergoing percutaneous coronary intervention ("PCI"). Eptifibatide is also indicated for use at the time of percutaneous coronary interventions, including procedures involving intracoronary stenting.
Many reported synthetic approaches to eptifibatide have employed known techniques of solid-phase peptide synthesis as described, for example, in U.S. Pat. Nos. 5,318,899; 5,686,570 and 5,747,447. A commercial-scale, liquid phase process was also reported at the 1999 IBC Conference on Peptide Technologies, "Peptisyntha's Method of Producing GMP Peptides on an Industrial Scale". The commercial process is a convergent synthesis involving the separate preparation of two fragments: Mpa-Har-Gly and Asp-Trp-Pro. The coupling of these two fragments provides six of the seven residues needed for eptifibatide. The last residue attached is an S-trityl-protected cysteinamide as described, for example, in U.S. Pat. No. 5,506,362. After removal of the S-trityl protecting groups (on the cysteinamide and mercaptopropionyl residues), ring closure is then achieved by disulfide bond formation. Crude eptifibatide obtained by the commercial process has a reported purity of about 80%. Two column chromatography steps improve the purity to greater than 99%.
Liquid-phase synthesis has generally been viewed as more feasible than solid-phase synthesis for the large-scale manufacture of eptifibatide. However, solubility issues and the generation of complex reaction mixtures present challenges for large-scale liquid phase processes. Complex reaction mixtures, for example, make purification of the product more difficult. Ways exist to overcome these problems, such as the use of persilylated amino acids and phase transfer reagents, as described, for example, in U.S. Pat. No. 4,954,616, and extensive chromatographic purification, but such means add to the cost of the overall process.
A need thus exists for alternative processes for the manufacture of eptifibatide.


A temperature-compensated capacitor device has ferroelectric properties and includes a ferroelectric capacitor using a ferroelectric material such as a metal oxide ferroelectric material, a negative-temperature-variable capacitor using a negative-temperature-coefficient-of-capacitance material such as a metal oxide paraelectric material, and an electrical series connection between the negative-temperature-variable capacitor and the ferroelectric capacitor. The temperature-compensated capacitor device may be formed as an integrated layered structure, or as separate capacitors with a discrete electrical connection therebetween.

Ferroelectric materials are used in a variety of applications. One such application is a ferroelectric capacitor used in a nonvolatile, random access memory whose information is retained even after a power loss. A ferroelectric material is one whose physical state changes upon the application of an electrical field, in a manner analogous with the change undergone by ferromagnetic materials to which a magnetic field is applied. A memory cell may be constructed based upon the hysteresis effects associated with the physical state change. The ferroelectric material has the advantages that its physical state is controlled by the application of a voltage rather than a magnetic field, a measurable state is retained after a power loss, and small-size memory elements may be constructed by microelectronics fabrication techniques, resulting in memory elements that consume little power.
One difficulty with using ferroelectric materials in some applications of interest, such as ferroelectric nonvolatile memory, is that some of the material properties such as permittivity change substantially over relatively narrow temperature ranges. These properties change so greatly, in some cases more than 100 percent over a temperature range of less than 100° C., that the associate read/write electronics can be quite difficult to design and implement.
Ferroelectric materials such as barium titanate, strontium titanate, calcium titanate, calcium stannate, and calcium zirconate are also used to produce discrete ceramic capacitors. For the discrete capacitor application, the material composition is varied to provide a relatively high permittivity over a specified temperature range. While these devices are optimized to provide a relatively constant capacitance value over a specified temperature range, they are not useful to non-volatile memory applications due to their lack of a remnant polarization component which can be used for information storage.
There exists a need for an improved approach to the design of electronic circuits that utilize ferroelectric properties, to reduce the effects of temperature variations. The present invention fulfills this need, and further provides related advantages.

Temperature-compensated ferroelectric capacitor device, and its fabrication