In an optical recording medium in which marks are allowed to be written at grooves and information has been recorded beforehand in the form of prepits in a prepit area, the medium is constructed so that the groove width, Wg, the land width, Wl, and the prepit width, Wp, satisfy the relationships of either Wl less than Wg, and Wp less than Wg, or Wl greater than Wg, and Wp greater than Wg. Alternatively or additionally to the above, a sum of lengths of pit-presence portions in the prepit area is larger than a sum of lengths of pit-absence portions in the prepit area.

The present invention relates to recordable (once-writable) and rewritable information-recording media, and more particularly, to optical discs.
Recently, the densification of such optical discs, which are used as recording devices for computers, or package media for music and image information, has been advanced. In order to have precise, high-speed access to such high-density tracks, it is necessary to provide preformatted signals having address information to a recording surface of the optical disc, to and from which surface information is recorded and reproduced. Further, information that one does not want to erase can also be formed in advance as preformatted signals on the disc. Portions other than the preformatted portions are a recording area in which guide grooves referred to as simply xe2x80x98groovesxe2x80x99 are formed. In the groove area, namely, in the recording area, grooves that are concave portions and lands that are not concave portions exist.
FIGS. 5A and 5B show a disc of related art, and are a top view and a perspective view of the disc, respectively. In FIG. 5B, a cross section of the disc is also shown. Reference symbols xe2x80x98Gxe2x80x99 and xe2x80x98Lxe2x80x99 indicate a groove and a land, respectively. Reference symbol xe2x80x98PPxe2x80x99 indicates a prepit. Light 3 (typically, a laser beam) is condensed by a lens 2 and then incident through a substrate 1. Comparing the land with the groove, the groove is nearer to the lens 2.
A recording layer of a material represented by a magneto-optical material, a phase-change material or an organic dye material is formed (not shown in the figures) on the lands, grooves, and prepits. In the figures, a recording mark M is written in the groove. This is because better signals in quality are obtained when the information is written in the grooves than when written on the lands.
When recording/reproducing information onto/from the optical disc on which the guide grooves are formed as described above, tracking servo control is implemented by a push-pull method using a servo control signal called the xe2x80x98push-pull signalxe2x80x99 resulting from the diffraction of light at the grooves and prepits. A light beam (xe2x80x98beam spotxe2x80x99) condensed by the lens 2 tracks on the grooves and prepits.
Generally, the push-pull signal in the prepit area has a smaller amplitude than the push-pull signal in the groove area. The reason for that is as follows. The structure of the prepit area in which concave portions are spaced from each other is equivalent to the structure of a broken, or discontinuous groove. Therefore, in the prepit area, due to the discontinuity of the concave portions, the amount of diffraction of light is reduced accordingly on the average. This is why that the amplitude of the push-pull signal is smaller in the prepit area than in the groove area.
Accordingly, if the gain of the tracking servo control is adjusted so that it is suitable for the groove area, the amplitude of the push-pull signal in the prepit area becomes too small. Therefore, the gain of the tracking servo control is relatively small for the prepit area, and the control precision deteriorates. In contrast, if the gain of the tracking servo control is adapted to the prepit area, the amplitude of the push-pull signal in the groove area becomes excessively large. Thus, disadvantageously, oscillation occurs in the tracking servo system.
The present invention has been made in order to solve the above problems, and the object of the present invention is to provide a highly reliable optical recording medium with a prepit area wherein recording is implemented at least at grooves, and push-pull signals obtained in a groove area (recording area) and a prepit area have similar magnitudes so that precise tracking can be implemented without deterioration of control precision nor occurrence of oscillation of the tracking servo control system, whereby complication of the circuitry of a recording/reproducing device and the increase of the costs of such a device can be avoided.
In order to accomplish the above object, according to an aspect of the present invention, there is provided an optical recording medium, comprising a substrate having a recording area, composed at least of lands and grooves, and a prepit area in which information has been recorded beforehand in the form of prepits, the recording area being recordable at least at the grooves among the lands and grooves, the optical recording medium being constructed such that a width of each groove, Wg, a width of each land, Wl, and a width of each prepit, Wp, satisfy the following relationships of:
either Wl less than Wg, and Wp less than Wg, or Wl greater than Wg, and Wp greater than Wg.
With this arrangement, the amplitudes of the push-pull signals from the recording area (groove area) and the prepit area can be made equivalent to each other or little different from each other. Thus, it becomes possible to achieve accurate tracking servo control. Accordingly, there is an effect that it is possible to prevent the complication of the circuitry and the cost increase of a recording/reproducing apparatus for the optical recording medium.
According to another aspect of the present invention, there is provided an optical recording medium, comprising a substrate having a recording area, composed at least of lands and grooves, and a prepit area in which information has been recorded beforehand in the form of prepits, the recording area being recordable at least at the grooves among the lands and grooves,
wherein a sum of lengths of pit-presence portions in the prepit area is larger than a sum of lengths of pit-absence portions in the prepit area.
The inventor of this invention has found that by increasing duty of prepits (also referred to as simply xe2x80x98pitsxe2x80x99) which is calculated from (the sum of lengths of the pit-presence portions in the prepit area)/(the sum of lengths of the pit-presence portions and pit-absence portions in the prepit area), it is possible to increase the amplitude of the push-pull signal from the prepit area. The optical recording medium with this arrangement has duty of prepits of more than 50%. Thus, even if the prepit width is same as the groove width so that there is a difference in amplitude of the push-pull signal between the groove area and the prepit area, the difference can be decreased. As a result, it is possible to achieve accurate tracking servo control. Furthermore, because the same width can be used for the grooves and the prepits for the above reason, the optical recording medium can be simply fabricated.
The above characteristic features of the first and second aspects of the present invention may be combined so that not only the widths of the grooves and prepits but also the duty of prepits are changed. In this case, freedom is increased in designing the optical recording medium such that there is no difference or little difference between the amplitudes of the push-pull signals from the groove area and the prepit area.
Other objects, features and advantages of the present invention will be obvious from the following description.


Self-biased bipolar ring-oscillator phase-locked loops with a wide tuning range are disclosed. In a particular example, an apparatus to provide a phase-locked loop is described, comprising a voltage-controlled oscillator (VCO) to provide an output clock signal having a frequency, a quantizer, a phase-frequency detector to generate an adjustment signal, and a charge pump to modify the control voltage. The example VCO includes several ring-oscillator stages, where each ring-oscillator stage includes several gain stages to provide several output currents based on a comparison of a control voltage and several corresponding threshold voltages. The example quantizer includes several comparators to generate digital signals based on the output currents. The example charge pump modifies the control voltage based on the digital signals and the adjustment signal, and includes several switching elements to increase or decrease current to the charge pump based on the digital signals.

Phase-locked loop (PLL) circuits are used to generate clock signals having a fixed phase relationship with respect to a reference clock signal. Typical phase-locked loop circuits include a voltage-controlled oscillator (VCO), a loop filter, and a phase-frequency detector. The VCO generates a clock signal having a frequency that varies based on a control voltage, and the phase-frequency detector adjusts the control voltage via the loop filter based on a comparison of the phase relationship of the clock signal and the reference clock signal.
One type of VCO is a ring-oscillator VCO, in which an odd number of ring-oscillator stages are connected in series. Each stage inverts an input signal provided by a prior stage and passes the inverted input signal to a next ring-oscillator stage. The final ring-oscillator stage has an output signal that is provided as a clock signal and that is fed back to the input of the first ring-oscillator stage to form a loop. Due to alternating input voltages and gate delay, the clock signal from the ring-oscillator has a predictable frequency that is generally proportional to an input control voltage. In existing ring-oscillator VCO circuits, gain stages in each ring-oscillator stage function the same way, resulting in VCO circuits with limited tuning range and nonlinear frequency-control voltage relationships, which are undesirable features for a PLL circuit.

Self-biased bipolar ring-oscillator phase-locked loops with wide tuning range


A coaxial audio cable is provided having a core, braided inner and outer conductors, dielectric layer between the inner and outer conductor and a jacket surrounding the outer conductor. The inner conductor is disposed around the core at a braid angle of approximately eighteen degrees. The dielectric layer is wrapped around the braided inner conductor. The outer conductor is disposed around the dielectric layer at a braid angle of approximately thirty-eight degrees. The cable is designed to provide a 5:6 overall ratio between the number of strands in the inner conductor and the number of strands in the outer conductor. The inner and outer conductors of the coaxial audio cable are designed to have matching series impedances.

1. Field of the Invention
This invention relates generally to coaxial cables and in more particular to a coaxial cable having inner and outer conductors with matching series impedances for audio applications.
2. Description of the Prior Art
Coaxial cables for use in a variety of purposes are well known. Coaxial cables are made in three general types for different applications: flexible, semirigid or rigid. The more rigid the cable, the more predictable and stable its electrical properties. A few examples of such cables are U.S. Pat. No. 2,436,421 issued to Cork, U.S. Pat. No. 2,342,736 issued to Herzog et al., U.S. Pat. No. 1,781,092 issued to Affel et al., and U.S. Pat. No. 3,351,706 issued to Gnerre et al.
U.S. Pat. No. 1,781,092 to Affel discloses to a conducting system for transmitting with small attenuation a band of frequencies. The conducting system employs a circuit having concentric conductors of relatively large diameter, one acting as return for the other. The inner conductor is formed by spirally winding a plurality of wires about a suitable core, thus forming in effect a hollow conducting shell. Dielectric spacing washers are mounted upon the inner shell to form a support for the outer conductor. The outer conductor is formed by spirally winding a plurality of wires over the outer surfaces of the supporting washers to form an outer conducting shell. A waterproof covering then surround the entire surface of the outer conductor to protect the system from moisture.
U.S. Pat. No. 2,342,736 to Herzog et al. discloses to a wide-band radio cable of constant attenuation which is suitable for distortionless transmission up to a certain frequency value. The cable includes an internal conductor consisting of interlaced radio strands and is seated on a hemp-cord. The conductor is embedded in a plastic insulating compound. The outer conductor consists of interlaced radio strands and is mounted on the insulating compound surrounded with an insulating sheath.
U.S. Pat. No. 2,436,421 to Cork discloses to the transmission of electrical energy by electric cables of the concentric line type. The cable includes an inner conductor of drawn copper wire which is held centrally of a sheath of insulating material by a thread of the same material. The outer conductor consists of a braided sheath composed of strands of copper wire. The individual strands being insulated from each other by enamelling or shellac. The outer protective covering of the cable consists of a sheath of polyethylene.
U.S. Pat. No. 3,351,706 to Gnerre et al. discloses to a submarine coaxial cable consisting of a central metallic conductor embedded in a layer of dielectric material and with a braided conductor of wire strands located between an inner layer of solid dielectric and an outer layer of solid dielectric. Both conductors are copper or other highly conductive material and the dielectric layers are of a polyolefinic material.
The prior art fails to provide a coaxial cable having an inner and outer conductor having matching series impedances. By having matching series impedances, a superior signal can be transmitted by the cable. Such superior signal transmission is highly desirous for use with premium-quality sound systems. It is, therefore, to the effective resolution of the aforementioned problems and shortcomings that the present invention is directed.


A food serving device and method for keeping different food items separated prior to their consumption. The device harnesses gravitational flow to allow desirable or undesirable liquids to flow to a receiving compartment (20). In a preferred embodiment, a cereal bowl (10) maintains the crispness of cereal by keeping the cereal in a separate compartment (12) away from milk or other liquid which is kept in liquid reservoir compartment (26). Liquid from reservoir compartment (26) gravitates through channel (38) to the receiving compartment (20). Cereal is pulled toward the user from the cereal compartment (12) and falls into the awaiting liquid in the receiving compartment (20). Additionally, the cereal in the receiving compartment (20) is geographically confined to limit its dispersement so a spoon can be used to easily scoop out a portion of the cereal and the liquid.

1. Field of the Invention
This invention relates to food serving devices and methods. More particularly, it relates to a cereal bowl for maintaining the integrity of cereal throughout a meal and to a device that permits drainage of liquid.
2. Description of the Prior Art
Cereal, commonly eaten with milk products or substitutes, has a general tendency to become undesirably soggy from prolonged contact with liquid before it is consumed. As a result, many meals are not enjoyable and often times part of the meal is discarded because the user does not want to eat soggy cereal.
Inventors have created several types of bowls and devices to reduce this problem of soggy cereal. However, all of these devices possess drawbacks and none of them are commercially available.
For example, the device shown in U.S. Pat. No. 876,808 to Kinert (1908) has an elevated cereal compartment to keep the cereal up and out of the milk. This device must be tilted to gather the milk. U.S. Pat. No. 1,100,298 to Hass (1914) discloses a kitchen utensil for mixing mayonnaise dressing. U.S. Pat. No. 1,272,996 to Poschadel (1918) shows a divided dish for use with soup or ice cream. The apparatus disclosed in U.S. Pat. No. 1,520,402 to Clemans (1923) includes two compartments, one large and one small, with a low section in the wall between them to facilitate the transfer of cereal between them. U.S. Pat. No. 2,207,417 to Smith (1938) discloses a hopper feed cereal bowl having a tall, elongated shape. U.S. Pat. No. 2,843,287 to Finley (1954) and U.S. Pat. No. Des. 176,252 to Duncan (1955) disclose serving pieces having two compartments with a low section in the wall between them to facilitate the transfer of food between them. U.S. Pat. No. 4,069,940 to Naimoli (1978) discloses a bi-level device with a high quantity of parts involved. U.S. Pat. No. 4,351,444 to Majewski (1982) discloses a bowl with a costly additional item required to tilt the bowl, which increases the chances for spillage. U.S. Pat. No. Des. 283,096 to Uhrik (1986) shows a device having two compartments, one large and one small. U.S. Pat. No. Des. 298,898 to Roshau (1988) shows an elongated bi-level bowl. The device disclosed in U.S. Pat. No. Des. 305,846 to Griffith (1990) has a costly insert. Finally, U.S. Pat. No. 4,986,433 to Davis (1991) discloses a device with two bowls connected by an elongated chute.
Although all of the above mentioned inventions can be used to reduce the problem of cereal becoming soggy, they all suffer from drawbacks:
a) tilting required to gather the milk into a puddle for removal with a spoon;
b) cereal must be raked from a large flat surface;
c) large size, excessive weight, or an odd shape make some difficult to store;
d) some are inherently awkward;
e) many require that a small portion of cereal be placed in a large quantity of liquid. The cereal can then disperse due to a lack of confinement and must be pursued;
f) size, shape, or tilt require many to be abnormally large or else require the cereal and/or liquid to be replenished during the course of the meal due to inadequate or disproportionate volumes;
g) many are costly to produce due to the high quantity of parts;
h) the liquid and cereal are in different compartments and there is no way to measure their quantities in relationship to one another;
i) some enable a user to leisurely eat a bowl of cereal but do not assist in keeping the liquid cool over this extended duration;
j) some of these devices have uncommon shapes;
k) many of these would be difficult, if not impossible, to place in a modern dishwasher, especially for a family with several bowls needing cleaned at the same time.


A reciprocating saw has a tooth form that decreases the cutting time of the saw blade and extends the life of the saw blade. The tooth height is longer than conventional metal cutting reciprocating saws. Also, the tooth form has a larger gullet. The tooth rake angle remains substantially constant during the life of the saw blade.

The present invention relates to saw blades and, more particularly, to a tooth form for reciprocating saw blades.
Reciprocating saws are utilized to cut metallic and wooden materials. Ordinarily, when utilizing a reciprocating saw blade, the user generally looks at various aspects of the saw blade. When choosing a reciprocating saw blade, the user considers the expectant life of the saw blade; how many cuts before saw blade replacement occurs. Secondly, the user is concerned with the speed of the saw blade, how fast the saw blade cuts through the material. Next the user considers the durability of the saw blade; how long it will last under normal wear and tear. Finally, the user is concerned with the accuracy of the saw blade; how well will the saw blade follow its intended line of cut.
The present invention provides the art with a reciprocating saw blade utilized for cutting a metallic material. The saw blade increases the life of the saw blade as well as the speed of cut of the saw blade.
According to the present invention, a reciprocating saw blade comprises a rake cut face having a first end forming a tip and a second end being continuous with the first gullet. A relief face extends from the tip of the rake face and is continuous with a second gullet. The rake face defines a relief angle of between about 38° to about 42°. The rake face and the relief face define an included angle of about 45° to about 50°. The rake face has a desired tooth depth wherein the tooth depth is about 30% to 47% of the maximum gullet depth and about 18% to 26% of a pitch length. The first and second gullet have a radius of about 52% to 55% of the maximum gullet depth. Also, the rake face has an angle from about 0° to about 3°. The relief angle is about 40° and the included angle is about 50°.
According to a second aspect of the invention, reciprocating blade has a plurality of teeth comprising said teeth having a tooth form including a rake face with a first end forming a tip and a second end being continuously with the first gullet. A relief face extend from the tip of the rake face and is continuous with the second gullet. The relief face defines a relief angle of between about 38° to about 42°. The rake face and the relief face define an included angle from about 45° to 50°. The rake face has a desired tooth depth such that the tooth depth is about 30% to 47% of a maximum gullet depth and about 18% to 26% of the pitch depth. The saw blade includes set and unset teeth wherein the unset tooth is considered a raker tooth.
From the following detailed description taken in conjunction with the attached drawings and claims, other objects and advantages of the present invention will become apparent to those skilled in the art.

Tooth form design for reciprocating saw blade


The present invention relates to a method of treating insulin resistance or Syndrome X by administering a therapeutically effective amount of a somatostatin agonist or a pharmaceutical composition comprised of a somatostatin agonist to a patient suffering from insulin resistance or Syndrome X.

Non-insulin-dependent diabetes mellitus (NIDDM) is highly prevalent in the U.S. population, reaching 10-20% in people 50 years and older. This incidence is higher among certain ethnic groups (Harris, M. I., Diabetes Care 16:642-652 (1993)). The condition is associated in the early phase with obesity, especially visceral and middle obesity. The progression from obesity to non-insulin dependent diabetes is characterized by the gradual development of insulin resistance occurring at least 4-7 years before clinical diagnosis of NIDDM (Harris, M. I., Diabetes Care 16:642-652 (1993); Harris, M. I., et al., Diabetes Care 15:815-819 (1992)). Insulin resistance is defined as the decrease in the biological action of insulin on the classical insulin sensitive tissues, namely muscle and liver leading to a reduced uptake and utilization of glucose from the bloodstream. In response to the reduced actions of insulin, the mounting plasma glucose induces the pancreas to put out more insulin leading to a higher basal circulating levels of the hormone in the interprandial state. Thus, insulin resistance often presents as hyperinsulinemia (Bonner, G., J Cardiovascular Pharmacology 24(Suppl. 2):S39-S49) (1994)). Initially, the higher circulating levels of insulin compensate for the reduced sensitivity to the hormone. As the pancreas decompensates and becomes unable to keep up with the demand, a fragile metabolic state of impaired glucose tolerance results. In this state, the organism is unable to handle a high influx of glucose into the bloodstream, for example after a meal or to a glucose challenge. This typically demonstrated by the slow rate in normalizing plasma glucose after a meal compared to normal individuals. It is at this point that non-insulin-dependent diabetes is usually diagnosed.
The period of some 5-10 years proceeding the development of impaired glucose tolerance is thus associated with a number of hormonal imbalances, e.g., increased basal insulin and glucagon production, elevated adrenal corticoid secretion (Bjornstop, P., In: Current Topics in Diabetes Research, eds. Belfore, F., Bergman, R N, and Molinath, G M, Front Diabetes, Basel, Karger, 12:182-192 (1993)), giving rise to the characteristic enlargement of visceral fat mass, hypertension, insulin resistance, and hyperlipidemia.
The cluster of these metabolic abnormalities has been referred to as "Syndrome X", "Metabolic Syndrome", "insulin resistant syndrome", or "Plurimetabolic Syndrome" (Reaven, G. M., Diabetes 37:1595-1607 (1988); Branchi, R., et al., Diab. Nutr. Metab. 7:43-51 (1994)). The condition was also shown to be associated with an increased risk for atherosclerosis, and coronary heart disease (reviewed in Wajchenberg, B. L., et al., Diabetes/Metabolism Reviews 10:19-29 (1994); Reaven, G. M., J. Int. Med. 236(Suppl. 736) :134-22 (1994); Woods, J. E., Ann. Intern. Med. 13:81-90 (1939); Modan, A., et al., J. Clin. Invest. 75:809-817 (1985)). Although the causal relationship between the various metabolic components remains to be confirmed (Donahue, R. P., The Endocrinologist 4:112-116 (1994); Fontbonne, A., Circulation 88(4 Pt.1):1952-1953 (1993); Jarrett, R. J., Diabetologia 37:945-947 (1994); Reaven, G. M., et al., Diabetologia 37:948-952 (1994); McCarty, M. F., Medical Hypothesis 42:226-236 (1994); Feskens, E. J. M., et al., Arteriosclerosis and Thrombosis 14:1641-1647 (1994)), insulin resistance appears to play an important role (Requen, G. M., et al., N. Eng. J. Med. 334:374-381 (1996); Despres, J-P., et al., N. Engl. J. Med. 334:952-957 (1996); Wajchenberg, B. L., et al., Diabetes/Metabolism Rev. 10:19-29 (1994)). There are no approved or confirmed effective treatments for the "insulin resistant syndrome" or "Syndrome X". Emerging data suggest that a number of therapies currently approved for the management of NIDDM may alleviate insulin resistance, e.g., Metformin (DeFronzo, R. A., et al., N. Eng. J. Med. 333:541-549 (1995)), Troghtazone (Kumar, S., et al., Diabetologia 39:701-709 (1996).
There is preliminary evidence in humans that acute infusion of somatostatin in obese hyperinsulinemic hypertensive patients resulted in a transient decrease in mean arterial blood pressure (Carretta, R., et al., J. Hypertension 7(suppl 6) :S196-S197 (1989)). Although this study pointed to a potential role of somatostatin in the management of hypertension associated with obesity, hypertension is only one of the clinical outcomes in the constellation of abnormalities associated with Syndrome X (Wajchenberg, B. L., et al., Diabetes/Metabolism Rev. 10:19-29 (1994)). A role of insulin is also implicated in the study. The involvement of insulin remains controversial as an acute increase in plasma insulin after a meal is typically associated with a reduction in blood pressure. Also, prolonged maintenance of hyperinsulinemia in animals does not raise blood pressure (McCarty, M. F., Medical Hypothesis, 1994, 42, 226-236). Also, epidemiologic studies have not yielded a clear-cut association between hyperinsulinemia and the risk for coronary heart disease (Jarrett, R. S., Diabetologia 37:945-947 (1994); Giuliano, D., et al., J. Endocrinol. Invest. 17:391-396 (1991); Feskens, E. J. M., Arterioscler. Thromb. 14:1641-1647 (1994); Ohmori, S., et al., J. Hypertension 12:1191-1197 (1994); Reaven, G. M., Diabetologia 37:948-592 (1994)).
The effect of somatostatin is mediated by a family of five somatostatin receptor isotypes. The current invention identifies a salient role of somatostatin agonists (e.g., somatostatin type-5 agonists) for the management of insulin resistance and Syndrome X as well as the normalization of metabolic changes that could mitigate development of disorders associated with Syndrome X, i.e. hyperlipidemia, insulin resistance and hyperinsulinemia.

This patent is subject to a terminal disclaimer.

Somatostatin and somatostatin agonists for treating insulin insensitivity and Syndrome X

Societe de Conseils de Recherches et d'Applications Scientifiques, S.A.S.


Retroreflecting optical constructions are disclosed. A disclosed retroreflecting optical construction includes a retroreflecting layer that has a retroreflecting structured major surface, and an optical film that is disposed on the retroreflecting structured major surface of the retroreflecting layer. The optical film has an optical haze that is not less than about 30%. Substantial portions of each two neighboring major surfaces in the retroreflecting optical construction are in physical contact with each other.

Retroreflective sheetings reflect incident light back toward the originating light source. Retroreflective sheetings are commonly used in, for example, road signs, license plates, barricades and safety garments to improve or enhance their visibility in poor lighting conditions.
Cube corners are commonly used in retroreflective sheetings. Typically, a cube corner includes three mutually perpendicular optical faces that intersect at a single apex. Generally, light that is incident on a corner cube from a light source, is totally internally reflected from each of the three perpendicular cube corner optical faces, and is redirected back toward the light source. Presence of, for example, dirt, water and adhesive on the optical faces can prevent total internal reflection (TIR) and lead to a reduction in the retroreflected light intensity. As such, the air interface is typically protected by a sealing film, but such films typically reduce the total active area, which is the area over which retroreflection can occur. Metallized cube corners do not rely on TIR for retroreflecting light, but they are typically not white enough for daytime viewing of, for example, signing applications. Furthermore, the durability of the metal coatings may also be inadequate.


An adaptive technique for calibrating a disk drive based on real time measurements. The invention includes a sensor for measuring a performance characteristics of a disk drive, a control circuit for comparing the measured performance characteristics to reference characteristics, and memory for storing performance parameters. The performance parameters are updated when the measured performance characteristics differs from the reference characteristic by a predetermined value, and the processor performs drive operations in accordance with the updated performance parameters. In the specific embodiments, the performance characteristic include disk runout and seek settle performance. A calibration flag may be set in the interface processor in response to the comparison of the measured performance characteristics to reference characteristics. An interrupt flag may be set for interrupting the calibrating of the runout performance when a demand for data is received by the drive, and a calibration command may be issued, e.g., to a servo controller, in response to the setting of the calibration flag. In response to the comparison of the measured performance parameters, the seek velocity may be decreased if the seek settle performance is worse than a minimum seek settle reference value and increased if the seek settle performance is better than a maximum seek settle reference value.

1. Field of the Invention
This invention relates in general to a method and apparatus for calibrating disk drives, and more particularly, to a method and apparatus for adaptively calibrating disk drive performance based on real time performance monitoring.
2. Description of Related Art
Over the past several years, most hard drive manufacturers have migrated from purely analog recording technology to drives that use digital electronics. This new technology includes digital read channels which have at least doubled the amount of information that can be packed into an area on a hard drive platter. Further advances have produced even greater improvements in density. For example, read channels implementing partial-response maximum-likelihood digital signal processing allow greater data density by enabling the disk drive to filter out the noise associated with densely packed data. One such example is U.S. Pat. No. 5,220,466, issued to Coker et al., entitled "METHOD AND APPARATUS FOR DIGITAL FILTER CONTROL IN A PARTIAL RESPONSE MAXIMUM-LIKELIHOOD DISK DRIVE SYSTEM", assigned to the assignee of this application, and incorporated by reference herein, which discloses controlling a digital filter function included in a data path within gain and timing control loops of a PRML magnetic recording channel. Such improvements in density are necessary as desktop machines move to applications that employ such rich data types as voice and video.
One application which employs rich data types such as voice and video data is video-on-demand. Video on Demand (VoD) is an interactive multimedia system that works like cable television, except that the customer can select a movie from a large video database. Individual customers in an area are therefore able to watch different programs when they wish to, making the system a realization of the video rental shop brought into the home.
The customer can call on a range of services from video-on-demand applications. While watching movies on television, performing operations such as video selection, pause, rewinding, etc., can be selected as if using a video player. Typically, these commands are processed by the set-top-box and sent to the local server. The local server processes the request if possible. Otherwise, it relays the request to a video archive server.
Digital video/audio information can be compressed and stored on hard disk and advertised for users on the network. Multiple archive servers can simultaneously be running over the same network, depending on the bandwidth available. Implementing a cost-effective and efficient video server is one of the most demanding engineering hurdles to be overcome. Such a server should have the capacity to hold hundreds of Gigabytes (or perhaps Terabytes) of digital information and provide simultaneous access to several hundreds (or thousands) of subscribers in real-time, giving each one an appropriate bandwidth (usually on the order of 1.5-6 megabits per second (Mbps)).
The storage subsystem consists of control units, disk storage and an access mechanism. There are several techniques for increasing the performance by interleaving the digital data of a program on multiple disks. For example, striping involves interleaving portions of disk blocks on multiple disk drives. The aim here is to reduce the latency for block access by parallel reading of the complete block, while attaining high data reliability. Declustering, on the other hand, distributes blocks of files on several disks within the same disk drive, thus allowing parallel block access from the same file and increasing the rate of the video stream. The overall performance can also be enhanced by replicating files among the servers by considering the demand for a program, relative dispersion of subscribers and the access patterns (eg., time/day of peak access, average number of simultaneous viewers, etc.).
Nevertheless, the disk drives of these video servers require extensive calibration to meet the demands of the video-on-demand environment. However, since the interruption of the data stream to perform such functions is undesirable, normal calibration techniques present unique problems. For example, current files require periodic calibration due to thermal changes and other factors. This limit prevents the file from meeting the video-on-demand specification. Currently, video-on-demand users have to disable the periodic calibration function to meet the constant data stream demand of video-on-demand. Due to the lack of thermal calibration, however, file performance will be significantly degraded.
Further, current files have to be designed to function under extreme ends of environmental variations. Power supply and temperature changes are just two examples. To accommodate these changes, additional design compromises have to be made. Yet it is important that system performance is not interrupted or degraded by calibration operations.
It can be seen then that there is a need for a method and apparatus for adaptively calibrating disk drive performance based on real time performance monitoring.

Method and apparatus for adaptively calibrating disk drive performance based on real time performance monitoring

International Business Machines Corporation


Disclosed is a semiconductor memory device, in which the refresh period of a fail cell or cells is set so as to be shorter than that of the normal cells, comprises a control circuit for exercising control in such a manner that, if, when refreshing the cell of a first address, generated responsive to a refresh command, with an input control signal being of a first value, a second address, differing as to the value of a predetermined bit from the first address, is determined to correspond to a fail cell, based on the information ore-programmed in a refresh redundant ROM, the cell of the second address is refreshed, and also in such a manner that, if, with the input control signal of a second value, the second address, differing as to the value of a predetermined bit from the first address, is determined to correspond to a fail cell, based on the predetermined information, only the cell of the second address is refreshed, without refreshing the cell of the first address, generated responsive to the refresh command.

FIG. 8 shows the configuration of a conventional semiconductor memory device. In FIG. 8, a memory cell array 1 forms a memory array divided into a plural number of segments as relief units (redundancy units). In FIG. 8, the ROW and the COLUMN of the memory cell array are divided into four segments and into two segments, respectively. A ROW address, generated by a peripheral circuit 2, is supplied to a switch (multiplexer) 3, an output of which is supplied to a ROW pre-decoder 4 and to a redundancy X-decoder (XDEC) 5. When a command for write or read access to or from a memory cell is entered, a ROW address, as an access address, supplied from outside, is selected by the switch 3 and thence transmitted to a ROW pre-decoder 4 and to the redundancy XDEC 5.
When a CBR (auto) refresh command is entered, an internal ROW address (refresh address), counted up in a CBR (Cas Before Ras) counter 6, is selected by the switch 3, based on the CBR signal, generated in accordance with the refresh signal, and thence transmitted to the ROW pre-decoder 4 and to the redundancy XDEC 5.
Outputs X3 to X12 of the ROW pre-decoder 4 are supplied to an X-decoder 7 (XDEC) to select a main word line, whilst outputs X0 to X2 are supplied to the memory cell array 1 for use for selecting a sub-word line provided with a ratio of 8 per main word line.
The count value of the CBR counter 6 is counted up each time a CBR (auto) refresh command is entered.
When an output signal (internal ROW address) of the switch 3, supplied to the redundancy XDEC 5, coincides with a ROW redundancy address, programmed in the redundancy XDEC 5, a redundancy main word line, decoded by the redundancy XDEC 5, is selected in place of a main word line decoded by the X-decoder 7. Similarly, when a COLUMN address, supplied to a redundancy YDEC 18, coincides with a redundancy COLUMN address, programmed in the redundancy YDEC 18, the selected COLUMN line, decoded by a YDEC 9, is controlled to be not selected, whilst a selected redundancy COLUMN line, decoded by the redundancy YDEC 18, is selected. In FIG. 8, the input/output circuit 12 is used for writing and reading data to and from the cell array 1.
In a conventional process for relieving fail cells in a conventional semiconductor memory device, a memory cell array forms an array divided into a plural number of segments as relief units. When an output signal of the switch 3, supplied to the redundancy XDEC 5 (internal ROW address signal) of FIG. 8, coincides with a ROW redundancy address, as programmed in the redundancy XDEC 5, the main word line, decoded by the XDEC 7, is non-selected, while a redundancy main word line, decoded by the redundancy XDEC 5, is selected.
If, in the conventional relieving process for fail cells in the conventional semiconductor memory device, a redundancy circuit is already used up in a given segment, the semiconductor memory device cannot be relieved, because the redundancy circuit has already been used up, even though there are left usable redundancy circuits in the other segments. Thus, there arises the necessity for providing more redundancy cells, thus increasing the cost of a chip.
For example, there is disclosed in Patent Document 1 a semiconductor memory device which performs refreshing for specified cells having poor refresh characteristics more frequently than other cells to relieve the specified cell to reduce the chip area as well as to reduce the costs.
[Patent Document 1]
JP Patent Kokai Publication No. JP-A-4-10297 (from page 3 right upper column line 4 to page 4 right upper column line 12 and FIGS. 1 to 3)

Semiconductor memory device and test method therefor


The present invention provides for thin sheet wedges that comprise a mica matrix impregnated with a conductive resin. The mica matrix is composed of mica flakes. The thin sheet wedge has a semi-conductive property of 500–500,000 ohms per square. In one embodiment the thin sheet wedge further comprises at least one glass fiber layer. In a particular embodiment the glass fiber layer is a backing for the mica matrix. In another particular embodiment the glass fiber is interwoven with the mica matrix. The glass fiber layer may itself be impregnated with a conductive resin.

The armature of a power generator is made up of a magnetic iron core, referred to as a stator core, that guides the magnetic flux, and conductive windings that carry the current. The magnetic core is cylindrically shaped and made up of thousands of thin laminations of steel clamped together to make a solid structure. The core has axial slots for the conductive windings, and these windings form loops around arcs of the stator core. A loop is formed by a coil that includes the conducting wires insulated from the core so that the wires can maintain a voltage difference from coil to coil and from coil to core. The coils fit into the slots in the core. FIG. 1 illustrates one example of how a portion of the end of a stator core 20 may appear. This figure focuses on a cross section of one slot 28. As shown, the stator comprises many neighboring coils 26 aligned in unison around the shaft, though gaps 30 between the coils and the surrounding abutments are usually tough to avoid.
The insulated coil width must be slightly smaller than the width of the slot to allow the coil to be installed in the slot. Once the coil is installed, it must be tightened in the slot; therefore, side wedges are driven between the slot wall and the coil. Additionally springs and wedges are driven at the top of the slot to keep the coils radially tight in the slot. It is important that the coils are tight in the slot because movement can cause wear of the insulation. Electromagnetic forces that peak twice per cycle exist that would vibrate a loose coil radially. Weaker forces also exist that would vibrate a loose coil circumferentially.
Traditionally side wedges have been composed of the thin sheets of mica or semi-conducting glass epoxy wedges. Each with their own advantages. Mica has advantages in that it is strong yet flexible, and is resistant to the generator environment. Further, due to the flaky nature of mica sheets, if a thin sheet mica wedge begins to lose cohesion through delamination, it will actually expand, further tightening itself within the slot.
Despite the benefits of using thin sheet mica wedges, it has been found that the semi-conducting wedges improve generator performance by dissipating any surface charge from the wound coils. Since mica is such a good insulator, other materials were needed to make semi-conductive thin sheet wedges. One technique is to impregnate a laminated glass fabric with a conductive resin. However, the laminated glass is not as stiff as the mica, and does not make as strong a supportive wedge. Further, under the strong electrical and magnetic conditions of the generator, the resin impregnated glass breaks down; and unlike the mica that actually expands when delaminating, the organic matrix simply disintegrates leaving a loose fragile glass weave.
Efforts have been made to combine the semi-conductive nature of the resin impregnated glass with the strong support of the mica by inserting alternating wedges of the glass and mica. Unfortunately that produces a wedge matrix that is neither fully supportive nor properly semi-conductive.
What is needed is a thin sheet wedge that has the strength and durability of a mica sheet, while also exhibiting the semi-conductive properties of a resin impregnated glass sheet.

Thin sheet mica wedges with semi-conducting properties


A method includes providing at least one target bandwidth for bandwidth usage on an interconnect, the target bandwidth being for traffic associated with a traffic initiator. The method also includes measuring a served bandwidth and resetting the measuring of served bandwidth in response to an occurrence of an event.

1. Technical Field
Some embodiments relate to arrangements and methods to allocate target bandwidth, which may be used for quality of service management.
2. Description of the Related Art
Ever increasing demands are being placed on the performance of electronic circuitry. For example, consumers expect multimedia functionality on more and more consumer electronic devices. By way of example only, advance graphical user interfaces drive the demand for graphics processor units (GPU). HD (High definition) video demand for video acceleration is also putting an increased demand for performance on consumer electronic devices. There is a trend to provide 2D and 3D TV on an ever increasing number of consumer electronic devices.
In electronic devices, there may be two or more initiators which access one or more targets via a shared interconnect. Access to the interconnect is managed in order to provide a desired level quality of service for each of the initiators. Broadly, there are two types of quality of service management: static and dynamic. The quality of service management attempts to regulate bandwidth or latency of the initiators in order to meet the overall quality of service required by the system.


Flow capture device and method for removing cells from blood The current invention discloses a blood treating and/or purifying device for removing circulating pathogens, preferably pathogenic cells, more preferably circulating tumor cells from the blood of a patient, a method of producing such a device and method to treat cancer and other diseases caused by virus infection, bacterial infection and parasites infection as well as autoimmune disorders. The described method is an extracorporeal medical therapy, thus can be done also in a hemodialysis system. The current invention also describes a device and an in-situ production method of preparing the device to remove CTC and other pathogens i.e. virus, bacteria or parasites from the bloodstream.

More than 90% of cancer deaths are due to metastases reported by the Viovy group in the Curie Institute [Autebert, J., et al., Microfluidic: an innovative tool for efficient cell sorting. Methods, 2012. 57(3): p. 297-307.] a well-known center of cancer research. While the entire tumorigenesis progress is not fully understood, it is strongly suggested that cells spreading from the primary tumor play a key role to initiate the metastatic process. Thus, in this patent application, circulating tumor cells (CTC) are defined as cells escaped from the primary tumor and circulating in the cardiovascular system. Tumor proliferation and invasion elevates the concentration of regular and irregular metabolites in the serum, which may alter and possibly inhibits the normal function of the entire human homoeostasis. One of the most abundant members of such tumor metabolites (also referred to as cytokines) is the tumor necrosis factor (TNF). Parallel removal of CTCs and their metabolites could alleviate the metastatic process and improve the patients' quality of life in conjunction with prolonged life expectancy.
Several attempts have been made to remove pathogens and in particular circulating cancer cells from blood stream of a patient.
Several authors applied extracorporeal deterioration of circulating cells For example, in U.S. Pat. No. 8,057,418 B2, [Korbling, M., et al., Devices and methods for extracorporeal ablation of circulating cells. 2011] an extracorporeal continuous flow pathway accesses the patient's blood to apply an external energy source to the blood at an ex vivo ablation device to result in the damage or death of the target cells. In U.S. Pat. No. 9,526,823 B2 [Yoshioka, S., Cell treatment device, cell treatment cartridge and body fluid treatment system. 2010] a complex cell treatment device is describe which allows cell dispersion liquid including cancer cells to pass therethrough to cause at least the cancer cells to be subjected to at least one of a physical, chemical action and a biologically activating action.
Some authors apply filtering out the cancer cells by some physical means like a membrane. For example, in US2014074007A1 [McNeil, Gary L, 2014] blood is separated with various filters.
GB2479536(A) [Lacy-Colson, Jon, Apheresis device and related methods 2011] describe in theory an apheresis filtration device for selective capture of circulating tumor cell from a patient's blood wherein the CTCs are captured to a solid support. However, no actual experiment has been carried out.
Gaitas, Angelo and Kim, Gwangseong [Chemically Modified Plastic Tube for High Volume Removal and Collection of Circulating Tumor Cells. PLoS ONE 10(7): e0133194. doi:10.1371/journal.pone.0133194] and in US2015121808A1 use a commercially available and chemically modified tube to selectively capture circulating tumor cells (CTCs) from the blood stream by immobilizing human anti-EpCAM antibodies on the tube's interior surface and were able to capture or entrap about 85% of cancer cells from suspension and 44% of cancer cells from spiked whole blood. The authors notify that the reduction in capture efficiency confirms the existing complications in CTC capturing in blood. They found that anti-coagulants can significantly interfere with the binding of EpCAM antibody to the targeted cancer cells.


System and method for improving performance of digital wireless communications systems in the presence of interferers. A preferred embodiment comprises generating a list of hypotheses from a list of known interferers and timing offsets, receiving a signal transmitted over-the-air, computing an error variance for each hypothesis, and selecting the hypothesis with the lowest error variance. The hypothesis can then be used to extract data from the received signal.

Interference is a major source of concern for the designers of wireless communications networks. Interference can reduce the overall performance of the communications system and if severe enough, cause the communications system to fail altogether. Interference can come from other electrical and electronic devices operating in the general vicinity and from other devices in the same communications network which are transmitting in the same (or adjacent) frequency band.
Interference from other devices in the same communications network can become a problem as designers of the communication network attempt to increase network capacity. For example, one way to increase network capacity is to increase frequency reuse, i.e., allow devices that are relatively close to one another to transmit in the same frequency band. In cellular communications networks, adjacent cell sites typically do not operate in the same frequency bands. However, through cell site sectoring, frequency reuse can be increased, therefore increasing network capacity. Unfortunately, when devices, which are close to one another, transmit in the same frequency band or in adjacent frequency bands, interference can occur. When devices transmit within the same frequency band, co-channel interference can occur, while adjacent channel interference can occur if devices transmit in adjacent bands if sufficient inter-band spacing is not provided.
In a GSM (Global System for Mobile Telephony) wireless communications system, for example, information is transmitted in bursts, wherein each burst may consist of two packets of data bits with a 26 bit mid-amble in between the two bursts. According to the GSM technical standards, one of eight possible training sequence codes (TSC) can be used as the mid-amble. In GSM communications systems, attempts to increase system capacity have resulted in increased co-channel and adjacent channel interference. Several attempts to reduce interference have been proposed. Most of the prior art relies on using at least two antennas at the receiver to suppress interference. However, due to cost reasons there is generally only one antenna in GSM handsets. With a single antenna at the receiver, one single antenna interference cancellation (SAIC) technique is to use the joint MLSE receiver.
A disadvantage of the prior art is that the complexity of the receiver can become very high. For example if the conventional receiver requires a 16-state Viterbi demodulator, then a joint MLSE which suppresses one interferer would require 256-states, which is a 16-fold increase in complexity.

Interferer detection and channel estimation for wireless communications networks


A forced puller includes a central seat having a threaded hole centrally defined therein and extending therethrough. The central seat has two opposite sides each having a rod perpendicularly extending therefrom relative to an axis of the threaded hole. Two hook members are respectively slidably mounted to a corresponding one of the two rods. Each hook member is formed with a hook engaged to a workpiece that is purposed to be detached. A main threaded rod is screwed through the threaded hole in the central seat. The main threaded rod has a polygonal head formed on a first end thereof for user to forcefully rotate the main threaded rod and a push portion is formed on a second end of the main threaded rod to securely and longitudinally abut against the workpiece after rotating the main threaded rod.

1. Field of the Invention
The present invention relates to puller, and more particularly to a forced puller that has a simple structure and is stably operated.
2. Description of Related Art
A conventional forced puller in accordance with the prior art shown in FIG. 8 comprises central seat (1) having a threaded hole (1a) centrally defined therein and extending therethrough. The central seat (1) has two opposite sides each having a rod (1) perpendicularly extending therefrom relative to an axis of the threaded hole (1a). Two hook members (2) are respectively pivotally mounted to a corresponding one of the two rods (1b) and correspond to each other. Each hook member (2) has a through hole (2a) laterally defined therein for pivotally received the corresponding rod (1b). Each hook member (2) includes a slot (2b) longitudinally defined therein and extending therethrough, and a hook (2c) extending from a distal end of each of the two hook members (2), wherein the two hooks (2c) are faced each other. A position seat (3) is mounted between the two hook members (2). The position seat (3) has a through hole (3a) centrally defined therein and co-axially aligning with the threaded hole (1a). The position seat (3) has two opposite sides each having a threaded rod (3b) perpendicularly extending therefrom relative to the through hole (3a). Each threaded rod (3b) extending through a corresponding one of the two slots (2b). Each threaded rod (3b) has a nut (3c) screwed thereon for positioning the position seat (3) after the threaded rod (3b) extending the corresponding slot (2b). A main threaded rod (4) is screwed through the threaded hole (1a) in the central seat (1). The main threaded rod (4) includes a polygonal head formed on a first end thereof for user to easily rotate the main threaded rod (4), a thread formed on an outer periphery of the main threaded rod (4) for coupling with the threaded hole (1a) and a operating portion (4c) formed on a second end of the main threaded rod (4) for longitudinally pushing the workpiece. The upper portion of each of the two hook members (2) is pivotally mounted to the corresponding rod (1b) and the middle portion of each of the two hook members (2) is positioned by the position seat (3). However, the two hook members (2) are unavoidably swayed during being operated. In addition, the slot (2b) will reduce the strength of the structure of each of the two hook members (2).
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional forced puller.


Systems and methods for controlling a fluid lens in a data collection device. One or more micropump control systems are used to control one or more fluid lenses. The micropump control systems are used to change volume and/or pressure within the fluid lens system, changing the radius of curvature of the lens.

In brief, a fluid lens comprises an interface between two fluids having dissimilar optical indices. The shape of the interface can be changed by the application of external forces so that light passing across the interface can be directed to propagate in desired directions. As a result, the optical characteristics of a fluid lens, such as whether the lens operates as a diverging lens or as a converging lens, and its focal length, can be changed in response to the applied forces.
Fluid lens technology that employs electrical signals to control the operation of the fluid lens has been described variously in U.S. Pat. No. 2,062,468 to Matz, U.S. Pat. No. 6,399,954 to Berge et al., U.S. Pat. No. 6,449,081 to Onuki et al., U.S. Pat. No. 6,702,483 to Tsuboi et al., and U.S. Pat. No. 6,806,988 to Onuki et al., in U.S. Patent Application Publication Nos. 2004/0218283 by Nagaoka et al., 2004/0228003 by Takeyama et al., and 2005/0002113 by Berge, as well as in several international patent documents including WO 99/18456, WO 00/58763 and WO 03/069380.
Additional methods of controlling the operation of fluid lenses include the use of liquid crystal material (U.S. Pat. No. 6,437,925 to Nishioka), the application of pressure (U.S. Pat. No. 6,081,388 to Widl), the use of elastomeric materials in reconfigurable lenses (U.S. Pat. No. 4,514,048 to Rogers), the uses of micro-electromechanical systems (also known by the acronym "MEMS") (U.S. Pat. No. 6,747,806 to Gelbart), the use of stack-type piezoelectric actuators to vary the focus of the lens member to compensate for temperature fluctuations (U.S. Pat. No. 6,188,526 to Sasaya et al.), the use of piezoelectric material to deform a variable focus lens (Japanese Patent No. JP2002243918), and the use of piezoelectric element in contact with a fluid such that the element changes dimensions in response to changes in voltage, changing the fluid pressure and altering the radius of curvature of an associated transparent membrane (GB Patent 1,327,503); the disclosures of the foregoing are hereby incorporated in their entireties herein.
There is a need for improved systems and methods for using fluid lenses in present day systems.
In the drawings, while every effort has been made to use like numerals to indicate like parts throughout the various views, the right is reserved to make corrections should errors become apparent.


A method and system for utilizing an interlocking dissimilar metal component in the formation of a hard disk drive is disclosed. The method provides a hard disk drive component having at least one interlocking dissimilar metal component, the at least one interlocking dissimilar metal component having at least two dissimilar metals on a single side. The interlocking dissimilar metal component is utilized to provide a similar materials weld location for coupling two dissimilar metals to a single side surface of the at least one interlocking dissimilar metal hard disk drive component.

Hard disk drives are used in almost all computer system operations. In fact, most computing systems are not operational without some type of hard disk drive to store the most basic computing information such as the boot operation, the operating system, the applications, and the like. In general, the hard disk drive is a device which may or may not be removable, but without which the computing system will generally not operate.
The basic hard disk drive model was established approximately 50 years ago and resembles a phonograph. That is, the hard drive model includes a hard storage disk that spins at a standard rotational speed. An actuator moves a magnetic read/write head over the disk. The actuator arm carries a head gimbal assembly (HGA) that includes a slider and a suspension with a nose portion for directly contacting a ramp used during the load and unload cycles for a load/unload drive. The slider carries a head assembly that includes a magnetic read/write transducer or head for reading/writing information to or from any desired location on the disk.
In operation, the hard disk is rotated at a set speed via a spindle motor assembly having a central drive hub. Additionally, there are tracks evenly spaced at known intervals across the disk. When a request for a read of a specific portion or track is received, the hard disk aligns the head, via the arm, over the specific track location and the head reads the information from the disk. In the same manner, when a request for a write of a specific portion or track is received, the hard disk aligns the head, via the arm, over the specific track location and the head writes the information to the disk.
Over the years, the disk and the head have undergone great reductions in their size. Much of the refinement has been driven by consumer demand for smaller and more portable hard drives such as those used in personal digital assistants (PDAs), MP3 players, and the like. For example, the original hard disk drive had a disk diameter of 24 inches. Modern hard disk drives are much smaller and include disk diameters 3.5 to 1 inches (and even smaller 0.8 inch). Advances in magnetic recording are also primary reasons for the reduction in size.
However, as the size of hard disk drives are reduced, the methods used for assembling the components within the hard disk drive and attaching components of the hard disk drive are quickly reaching there design limitations. For example, the suspension portion of the head gimbal assembly is stainless steel while the arm is aluminum. Presently, these dissimilar metals, e.g., the arm and suspension, are swaged together due to the inability of welding dissimilar metals. However, because of the overall reduction in component size, the swaging is no longer as reliable as it was when the components were bigger and more surface area was available. In some cases, the swaging of the smaller components results in distortions to the mount plate resulting in deleterious gram loading and static attitude changes at the head. Moreover, the dynamic flutter is also increased.
Solutions to the swaging issue brought on by component size reduction include adhesive bonding or modification of component make-up such as forming the arm from stainless steel. However, adhesive bonding is not re-workable and if it is incorrectly applied the parts are no longer usable and must be scrapped. This is an expensive solution. Additionally, the formation of the components from different materials, e.g., an aluminum arm, significantly degrades dynamic performance of the components.

Utilizing an interlocking dissimilar metal component in the formation of a hard disk drive

Hitachi Global Storage Technologies Netherlands B.V.


An article carrier which permits ice to be added to the carrier after removing the top to cool the contents. The carrier is formed from a paperboard blank having a waterproof interior surface. The end and side panels are connected by gusset panels, the end portions of which are adapted to be in nonadhered face-to-face relationship. When the top panel of the carrier is removed, these portions of the gusset panels are relaxed, allowing the side and end panels to pivot out about their foldable connection to the bottom panel for a limited distance to expand the interior of the carrier while maintaining the carrier in watertight condition.

There are many different designs of carriers used for transporting beverage containers, but none provides space to introduce cooling means directly into the carrier. Instead, it is necessary when picnicking or traveling to put the beverage containers in a cooler, such as an ice chest, in order to chill the contents. Although this is a conventional customary routine, it is nevertheless a cumbersome one, requiring room to be made in a vehicle for the cooler and requiring the heavy cooler to be carried to the picnicking area.
It would be much more convenient to be able to chill the contents of beverage containers by adding ice directly to the container carrier itself. In such a small confined space, a minimal amount of ice would be required to chill and maintain the chilled temperature of the containers. Because the area required for one or more carriers is much less than the room normally taken up by a cooler, the task of transporting cool beverages to their final destination would be greatly simplified.
Although such a method of cooling beverage containers in place would be much preferred over conventional methods, beverage container carriers of current design are not capable of receiving ice while the containers are still in the carrier. Basket-style carriers and open-ended wrap-around style carriers by definition are not suited for this function since they do not provide an enclosed area for receiving both containers and ice. Neither are conventional fully enclosed sleeve-type carriers capable of holding both beverage containers and ice because the normally tight fit of the beverage containers does not leave enough room for ice to be introduced into the carrier. What would be desirable is an enclosed watertight carrier which has the ability to be expanded to a size capable of holding ice in addition to the packaged beverage containers. It is an object of the present invention to provide a carrier which can function in this ideal manner.


An apparatus for controlling provision of power to a load by a plurality of generating devices in a plurality of phased signals during a first operating condition includes: (a) a sensing unit coupled with the load for presenting an indicator relating to load current; and (b) a control unit coupled with the sensing unit for receiving the indicator and coupled with the plurality of generating devices. The control unit presents a first control signal in response to the indicator indicating a second operating condition. The control unit presents a second control signal in response to the indicator indicating a third operating condition. The generating devices respond to the first control signal to substantially simultaneously provide the power to the load. The generating devices respond to the second control signal to substantially provide no power to the load.

The present invention is directed to electrical power supply devices, and especially to electrical power supply devices generating power using a plurality of generating units operating in a plurality of phases.
One design parameter involved in designing a power supply apparatus is the amount of capacitance one desires or needs at the output of converters providing current to the load. Capacitance may occupy significant area in implementing circuitry, such as power supply circuitry. The amount of capacitance required is at least partially dependent upon the amount of ripple current presented by the power supply device to the load. One benefit of reducing output capacitance is that the power supply apparatus may be configured using less board space and consequently be a smaller portion of a product in which it is employed. In today's marketplace with its emphasis on smaller more compact products, such a reduction in size is beneficial.
Multiphase DC-DC power supply apparatuses, especially multiphase power supply apparatuses embodied in multiphase converter apparatuses, have evolved to deliver more current to a load that is achievable using a single phase converter apparatus. Multiphase DC-DC apparatuses contribute other attributes as well such as, by way of example and not by way of limitation, increasing frequency of output ripple current from the power supply apparatus. Such reducing of output ripple current may permit some reduction in size of output capacitance for the power supply apparatus.
However, at least some capacitance is usually necessary for a power supply apparatus because ripple currents produced by inductors in the apparatus generally remain and must be accommodated. Capacitance at the output of a power supply apparatus also permits holding output voltages in regulation between the time a step increase in the load occurs and the time the control loop of the power supply apparatus can respond to the step load increase.
There is a need for an apparatus and method for controlling provision of power to a load by a plurality of generating devices such as a multiphase power supply apparatus that can efficiently respond to a step increase in a load yet minimize capacitance required at the power supply output.

Providing power to a load by controlling a plurality of generating devices


A magnetic head having a pair of magnetic core halves integrally bonded to each other, each magnetic core half being formed by a single-crystal ferrite piece and a polycrystal ferrite piece bonded together to constitute a junction ferrite, with a magnetic gap being defined between abutting surfaces of the magnetic core halves. The single-crystal ferrite pieces are arranged towards the abutting surfaces of the magnetic core halves and the polycrystal ferrite pieces are arranged on the opposite side of the abutting surfaces with respect to the single-crystal ferrite pieces. Preferably, the surface of the single-crystal ferrite piece having sliding contact with the magnetic recording medium, the gap surface of the single-crystal ferrite piece and the surface of the single-crystal ferrite piece corresponding to the lateral surface of the magnetic head are the (211) plane, (111) plane and the (110) plane, respectively. The directions of the <100>crystal axes within the plane (100) are symmetrical to each other on both sides of the magnetic gap. The magnetic head is low in sliding noise and superior in electro-magnetic conversion characteristics. In addition, the magnetic recording medium is superior in abrasion characteristics since the partial advancing abrasion is prohibited from occurring on its surface configured to have sliding contact with the magnetic recording medium.

This invention relates to a magnetic head employed for e.g., a video tape recorder. More particularly, it relates to such magnetic head having improved abrasion resistance.
In FIG. 1, there is shown a magnetic head made up of a pair of magnetic core halves 33m, 33n bonded to each other with a magnetic gap g3 defined between abutting surfaces of the magnetic core halves 33m, 33n. The magnetic core halves 33m, 33n are formed by bonding single-crystal ferrite pieces 31m, 31n and polycrystal ferrite pieces 32m, 32n to each other to form a junction ferrite. The magnetic head thus formed has its upper most portion, that is a surface configured for having sliding contact with a magnetic recording medium, constituted by the single-crystal ferrite pieces 31m, 31n, while having its lower most portion, that is its bottom surface, constituted by the polycrystal ferrite pieces 32m, 32n.
With the above-described magnetic head, the magnetic gap g3 formed at the junction portion of the magnetic core halves 33m, 33n and the top of the surfaces of the single-crystal ferrite pieces 31m, 31n on which slides the magnetic recording medium, referred to hereinafter as an R-TOP, are designed to be coincident with each other, so that the magnetic recording medium will be contacted with the magnetic head at the site of the magnetic gap g3.
This type of the magnetic head is effective to reduce the sliding noise since the single-crystal ferrite pieces 31m, 31n are of a small volume and the polycrystal ferrite pieces 32m, 32n take up a major portion of the volume of the magnetic head.
In addition, with such magnetic head, superior electro-magnetic conversion characteristics may be realized by selecting the orientation of the atomic plane of the single-crystal ferrite pieces 31m, 31n so that a surface 31a of the magnetic head on which slides the magnetic recording medium is the (211) plane, the gap surface defined by the abutting surfaces of the magnetic core halves is the (111) plane and the lateral surface 31c corresponding to the lateral surface of the magnetic head is the (110) plane, and by setting the direction A3 of the <100>crystal axis of the single-crystal ferrite piece 31m so as to be symmetrical with respect to the direction A4 of the <100>crystal axis of the opposite-side single-crystal ferrite piece 31n on both sides of the magnetic gap g3.
However, if the direction A3 of the <100>crystal axis of the single-crystal ferrite piece 31m is set so as to be symmetrical with respect to the direction A4 of the <100>crystal axis of the single-crystal ferrite piece 31n on both sides of the magnetic gap g3, as shown in Figs.2 and 3, partial advancing abrasion of the magnetic core half 33m differs from that of the opposite side magnetic core half since the angle of the crystal axis of the single-crystal ferrite core 31m with respect to the sliding direction B of the magnetic recording medium differs from that of the opposite side single-crystal ferrite core 31n, as a result of which partial advancing abrasion, that is an abrasion advancing non-uniformly for the magnetic core halves 33m, 33n, is produced.
If such partial advancing abrasion is produced, a so-called R-TOP offset T is incurred between the position R of the R-TOP and the position G of the magnetic gap g3, as shown in FIGS. 2 and 3, so that the position G of the magnetic gap g3 becomes non-coincident with the position R of the R-TOP thus deteriorating abutting contact between the magnetic recording medium and the magnetic head. That is, the contact position between the magnetic recording medium and the magnetic head is an offset position R due to the partial advancing wear, so that the magnetic recording medium cannot be contacted with the magnetic head at the site of the magnetic gap g3.


The invention discloses a handy battery charger comprising a body including upper and lower hollow cases that assemble together to form a receptacle for dry cells, said upper and lower cases having an opening at one end; a first connector with a plurality of connecting pins mounted on the opening, configured to be selectively connected to a second connector disposed at the bottom portion of a cellular phone to supply the output voltage from the dry cells to the cellular phone; a couple of resilient binding clips arranged at opposite ends of the first connector to prevent accidental release of the first connector from the second connector, wherein each of the resilient binding clips includes a hook at an upper end and a pivot axle part at a lower end, the hook having a protrusion extending in a direction to engage the second connector, said pivot axle part being bent in a direction perpendicular to the protrusion of the hook and disposed within a pivot groove formed in the body; and a plurality of positive and negative coil terminals to arrange the dry cells in series electrical connection and to supply the output voltage of the dry cells to the first connector, thereby providing the cellular phone with the dry cells in the recharged state at any time and achieving the cellular phone to be in a continuous use state.

The present invention relates to a handy battery charger for cellular phones, and more specifically, a handy battery charger to supply power to a cellular phone in case an indoor charger using alternating current or a vehicular charger is not available or the battery of the cellular phone is run out and needs a rapid charger.
Cellular phones are widely used. A spare auxiliary battery is often used by the user to replace the original cellular phone battery in the event of battery discharge or failure. If the auxiliary battery is not available, the cellular phone with the discharged battery must be recharged with an exterior charger or hands-free vehicle kit charger.
In order to continuously use a cellular phone, a user should keep a charged auxiliary battery at all times for the cellular phone. However, there is a tendency to only use the battery integral with the cellular phone because it causes user inconvenience to carry an additional auxiliary battery. Further, to carry the auxiliary battery may cause an unintentional short circuit of the recharging terminal of the auxiliary battery, resulting in discharge.
Limited use of the charger according to the place in recharging the cellular phone battery often brings about the battery discharge. Otherwise, the cellular phone should be in a standby state until the charger completes recharging operation.
Since a conventional charger generally utilizes an alternative current source, 110Vxcx9cV220V, designed for indoor or public use, it becomes difficult to recharge the battery at the outdoor place without an alternating current source. In a vehicle, power of 12xcx9c24V direct current is utilized to recharge the battery, but this often necessitates ignition of the vehicle and maintaining the charger and cellular phone inside the car.
The present invention is derived to solve the above conventional problems, and has an object to provide a handy battery charger for cellular phones, wherein dry cells are held in the charger body to readily recharge the cellular phone battery at any time regardless of the place.
In order to accomplish the above objects, there is provided a handy battery charger for cellular phones, comprising: a body including upper and lower hollow cases that assemble together to form a receptacle for dry cells, the upper and lower cases having an opening at one end; a connector with a plurality of connecting pins mounted on the opening, configured to be selectively connected to the connector disposed at the bottom portion of a cellular phone to supply the output voltage from the cells to the cellular phone; a couple of resilient binding clips arranged at the opposite ends of the connector to prevent accidental release from the connector, wherein each of the resilient binding clips includes a hook at an upper end and a pivot axle part at a lower end, the hook having a protrusion extending in a part at a lower end, the hook having a protrusion extending in a direction to engage the second connector, said pivot axle part being bent in a direction perpendicular to the protrusion of the hook and disposed within a pivot groove formed in the body; and a plurality of positive and negative coil terminals to arrange the dry cells in series electrical connection and to supply the output voltage of the dry cells to the first connector.
Therefore, the user can advantageously recharge the battery of the cellular phone by connecting the connector at the bottom side of the cellular phone to the handy battery charger of the present invention, thereby allowing the cellular phone to be in a continuous use state.

Handy battery charger for cellular phones

#3-303 Shindong-a apt., 5-426 (21/5) Mansu-dong, Namdong-gu

Na 1-101, Samwoo-villa, 77-8 (26/7) Yeockchon-dong, Eunpyung-gu


Connecting ends on a hose piece comprising several metal layers, in particular a strip wound metal hose piece, are produced by fixing the overlapping metal layers of a hose of larger length or of an endless hose in the region of the point of separation through welding and subsequently cutting off the hose piece from the longer hose or the endless hose. For simple and inexpensive fixing of the metal layers in the region of the point of separation, a welding seam is generated which extends through at least part of the periphery of the hose or about its entire periphery, using roller seam welding. The hose piece can subsequently be separated along the welding seam obtained in this manner, e.g. along its central line, thereby ensuring permanent and reliable fixing of the metal layers in the region of the connecting end.

The invention concerns a method for producing connecting ends on a hose piece having several metal layers, in particular, a strip wound metal hose piece, by fixing the overlapping metal layers of a hose having a larger length or of an endless hose in the region of the point of separation through welding to subsequently separate the hose piece from the longer hose or the endless hose. The invention also concerns a hose piece, in particular, a strip wound metal hose piece which comprises several metal layers and at least one connecting end in the region of which at least regions of the overlapping metal layers are welded together.
Hoses of this type comprising overlapping metal layers are used, in particular in the form of annular or helically strip wound hoses, as conduit elements in exhaust pipes of automotive vehicles. Due to their above-mentioned construction, they can accommodate certain length variations, as well as the bending and twisting which usually occur during operation of automotive vehicles, e.g. due to thermal expansion or vibration.
These conduit elements are manufactured, in particular, through helical winding of one or more layers of a metal strip. The positive connection of the neighboring regions of the strip or layers is effected through U-shaped profiles or folds. The production lines for such hoses are either endless or produce at least hose sections having a length of several meters.
For further processing, the strip wound hoses must be cut to a desired length. This separating process may not be effected by merely cutting perpendicularly to the hose axis, since fixation of neighboring layers would be partially destroyed and the strip end would burst open due to its internal tension leading to sharp tips or triangular protrusions at the strip end. Should a hose piece have such burst-open connecting ends, it cannot be further processed and must be rejected. Later fixing of the burst-opened metal layers in the region of the burst-open connecting ends is, in particular, not possible in practice, since the metal layers are exposed to bending loads.
In order to fix the connecting ends before separating off a hose piece from the longer hose or from an endless hose, the metal layers of the hose are conventionally fixed only mechanically in the region of the connecting ends (EP 1 281 904 A2). This may be effected through pressing, embossing, imprinting etc., of at least regions thereof. This requires, however, relatively expensive tools which must also be adapted to the respective hose geometry. Moreover, permanent fixing of the metal layers which would allow, in particular, later widening of the hose piece in the region of the connecting ends as is required for adjustment to the pipe diameter of neighboring pipe elements, is not possible in practice.
DE 44 11 246 A1 and EP 0 674 964 A1 describe a method for producing connecting ends on metal hoses of the above-mentioned type by laser welding a large number of welding points in the form of a stitch seam to fix the metal layers of an endless hose in the region of the subsequently produced connecting ends. Subsequent separation of the hose piece is effected by laser beam cutting.
One disadvantage is the substantial splashing during the required point welding of very oily and coated metal strips which can soil the processing optics and gas conduits. Moreover, two neighboring approximately parallel stitch seams or, at considerably reduced speed, one stitched seam must be produced, having a relatively large welding point diameter. This process is time consuming and therefore expensive. If the welding points have similar separations, there is always the fundamental risk that small residual triangular protrusions or nubs are formed after subsequent cutting off of the hose piece. The welded stitch seam at the terminating end of the strip wound hose tends to tear during a subsequent widening or calibration process leading to incomplete fixation in the region of the connecting ends. This can produce rejects, or at least considerably aggravate handling of such a hose piece. Subsequent widening or calibrating processes often produce breaks at the welded stitch seams in the longitudinal direction of the hose piece, which may extend over one or even more windings of the metal layers of the hose.
DE 198 51 173 C1 discloses a further method and a device for producing connecting ends on metal hoses of the above-mentioned type. The metal layers of the hose are also fixed by laser welding before the separating process, wherein a laser beam is guided continuously over the entire periphery of the hose piece thereby superposing a cyclic motion which subtends a finite angle with respect to the peripheral direction of the hose piece to produce the welding seam and generate an approximately sinusoidal or saw-tooth-shaped welding seam. This permits more effective and faster fixing of the metal layers in the region of the connecting ends of the hose piece and effectively prevents extensive splashing which occurs, in particular, during point welding. It however, also bears the danger that one or more metal layers are torn in the region of the connecting ends, in particular, during later widening or calibration processes of a hose piece produced in this manner.
It is therefore the underlying purpose of the invention to provide a simple and inexpensive method of the above-mentioned type which eliminates the described disadvantages and permits, in particular, perfect and load-resistant connection of the metal layers of the produced hose piece in the region of the connecting ends. The invention also concerns a hose piece produced in this manner.

Method for producing connecting ends on metal tubes and tube piece comprising such connecting ends

IWKA Balg- u. Kompensatoren-Technologie GmbH


An article carrier having bottom, top, side and end walls interconnected to form an enclosure of rectilinear configuration and having a pair of spaced apart hand hole openings formed in the top wall includes a reinforcing strip secured to the inner surface of the top wall and between the hand hole openings. End extensions which may or may not be adhered project from each end of the reinforcing strip and are folded into flat face contacting relation with the end walls respectively and are secured thereto. The fold lines between the end extensions and the cooperating end edges of the reinforcing strip are debossed so as to protrude inwardly and mate with a complementary embossed area which is encased by torque relief slits thereby reducing the tension along the outer surfaces of the fold lines between the top wall and the end walls so as effectively to strengthen the load bearing elements of the carrier top wall.

U. S. Pat. No. 2,849,112 issued Aug. 26, 1958 discloses a can carrier of the wrap around type in which the can chimes both top and bottom are arranged so as to reside in slits formed in the top and bottom edges of both side walls. Chimed cans under adverse conditions may tear the end corners of the carrier and thus effectively destroy the package. A pair of spaced scores are formed astride an inwardly folded panel and form embossments which reinforce the carrier at the upper and lower corners thereof at both ends of the carrier.
U. S. Pat. No. 2,872,036 issued Feb. 3, 1959 discloses a paperboard wrap around carrier for cans having inwardly folded reinforcing strips disposed about the end edges of the carrier and in which parallel double score lines are formed at the carrier corners which are out of alignment with the packaged can chimes and which thereby serve to strengthen the carrier.
U. S. Pat. No. 2,933,867 issued Apr. 26, 1960 includes an incidental disclosure of short slits formed at the top and bottom end corners of the carrier which serve to prevent tearing of the carrier structure due to the fact that these small slits are disposed in transverse relation to the carrier corners and close to the ends of the wrapper both top and bottom.


Multiple banks associated with a multiple set associative cache are stored in a single chip, reducing the number of SRAMs required. Certain status information for the second level (L2) cache is stored with the status information of the first level cache. This enhances the speed of operations by avoiding a status look-up and modification in the L2 cache during a write operation. In addition, the L2 cache tag address and status bits are stored in a portion of one bank of the L2 data RAMs, further reducing the number of SRAMs required. Finally, the present invention also provides local read-write storage for use by the processor by reserving a number of L2 cache lines.

The present invention relates to cache memory in a system having first and second level caches, and in particular relates to the storing of tag address and status information for the cache.
Many computer systems today use multiple cache memories to speed up retrieval of data. Such a system will typically have an array of DRAM chips for the main memory. The microprocessor chip itself can have a small, on-chip cache memory which is quickly accessed. This is referred to as a first level (L1) cache. In addition, a second level cache (L2), which is bigger than the microprocessor on-chip cache, is also used. This is typically a cache memory of SRAM chips, which are faster than the DRAM chips, but also more expensive than the DRAMs.
Both cache memories will contain a subset of what is in main memory. The first level cache will be a subset of what is in the second level cache. In operation, the microprocessor will first look in the first level cache, and then the second level cache before going to main memory. To maintain consistency in the caches, when data is written into the first level cache, the corresponding entry in the second level cache and eventually main memory needs to be updated as well. It is desirable to optimize the timing for these updates.
Since the cache is smaller than main memory, multiple main memory locations may be mapped into the same cache location. The cache entries must contain not only the relevant data, but also enough information ("tag address and status" bits) about the address associated with the data to be unambiguous. Hence, the cache must be wider than the data stored in it. To improve the cache "hit ratio", it is also desirable for the caches to be set associative, i.e., a particular location in memory may be stored in multiple locations ("sets") in the cache. The width of the cache (and the number of SRAMs used to implement the cache) doubles or quadruples for a 2- or 4-way set associative cache, respectively, compared to a 1-way set associative ("direct mapped") cache. It is desirable to reduce the number of SRAMs required to implement a cache from both cost and electrical performance reasons.

Set-associative cache memory utilizing a single bank of physical memory


In one embodiment of the invention, a method for protecting a content addressable memory is disclosed. The method includes storing a marker bit associated with each data block stored in a random access memory (RAM), states of the marker bit representing whether the data block was recently read from the RAM or recently written into the RAM; receiving a client address pointing to a starting address of a data block stored in the RAM; comparing the client address against one or more addresses stored in a content addressable memory (CAM) to determine a hit indicating the client address was stored in the CAM or a miss indicating the client address was not stored in the CAM; and in response to a miss, the method further includes checking a state of the marker bit associated with the data block pointed to by the client address.

A semiconductor memory may experience a hard error or a soft error. A hard error occurs when a read writeable semiconductor memory cell becomes stuck at one logical state and will not change to another logical state to store a data bit. A soft error occurs when the stored logical state of a read writeable semiconductor memory cell is upset and changes, such as from logical one to logical zero or from logical zero to logical one.
A soft error may be due to alpha particles, released from cosmic ray impacts for example, that upset the electronic charges representing the logical state stored in a memory cell. Alternatively, a soft error may be due to inadvertent decay in the electronic charges stored in a memory cell, such as from the age and decay of materials used in the manufacture of memory. A soft error may alternatively occur from electrical noise in a circuit coupled into a memory cell to alter the stored charges therein. In any case, the memory cell is usually not damaged and can be rewritten (referred to as scrubbed) to store the proper charge and logic state of data again.
There are different kinds of semiconductor memory with different kinds of semiconductor memory cells. Content addressable memory (CAM), also referred to as associative memory, is a type of semiconductor memory that functionally differs from a random access memory (RAM), such as a static random access memory (SRAM) or a dynamic random access memory (DRAM). With decreased transistor sizes due to semiconductor manufacturing improvements, more recently designed CAMs have greater capacities and have become less expensive to integrate into an integrated circuit. Thus, CAMs have become more popular to use as a component in integrated circuits. However, smaller transistor sizes and lower power supplies have made memory cells, such as those found in CAMs, more susceptible to soft errors.
With a RAM, in the case of a read operation, a memory address is provided to the RAM to read data out from memory locations therein associated with the supplied memory address. In the case of a write operation, a memory address is provided to the RAM to write data into memory locations therein associated with the supplied memory address.
With a CAM, data (e.g., address into another memory) may be randomly stored into lines of its memory locations (CAM lines) similar to a database. Like a search on a database, it is desirable to know if certain given data is stored in the CAM and if so, what CAM lines match the certain given data. The address of the CAM lines that match, referred to as a tag or pointer, often points to further information in a different memory. For example, a client supplies a word of data (a "client data word") that may or may not be stored in the CAM. The CAM searches throughout the words of data stored into the CAM lines for the client data word. If the client data word is found stored in the CAM, referred to as a hit, one or more addresses where the client data word is found are returned to the client. If the client data word is not found stored in the CAM, referred to as a miss, a miss signal is generated by the CAM.
The longer period of time that data is stored in a memory cell, the greater the probability it may experience a soft error. If a memory cell is refreshed periodically with new or rewritten data, the probability it experiences a soft error is less. In a CAM, data may be stored in the memory cells of CAM lines for a long period of time such that it may be more susceptible to soft errors. Furthermore, a greater storage capacity or size of a memory, increases the probability it may experience a soft error. Thus, larger CAMs may be more susceptible to soft errors.
The way in which CAMs function—stored data in all CAM lines is compared to a certain given data—makes it difficult to detect a changed bit due to soft error. If a soft error occurs in a CAM, a false miss or false hit may be generated which is undesirable. A false miss is particularly problematic, because the pointer provided by the CAM address is lost. A false hit is less problematic because it is easier to detect a false pointer provided by a false match in a CAM.
It is desirable to improve the control and operation of CAMs such that false misses can be detected in order to reduce failure rates and improve reliability of the overall systems that include CAMs.

Soft error protection for content addressable memory