An amorphous inorganic ceramic material including silicon, carbon and oxygen is provided. In the ceramic material, the average elemental ratio between silicon, carbon and oxygen is represented by a compositional formula:SiCaOb wherein, a is a number that satisfies: 0.5≦a≦3.0, and b is a number that satisfies 0.5≦b≦4.0), the material has a siloxane skeleton formed of Si—O—Si bonds, and the hydrogen mass fraction is within a range from 0 to 1% by mass. The material exhibits excellent heat resistance, wettability with other materials, strength and elastic modulus, and is useful as a reinforcing material for composite materials, or as an exhaust gas filter material or the like.

1. Field of the Invention
The present invention relates to a novel amorphous inorganic ceramic material that exhibits excellent heat resistance and the like, and a method of producing such a material, as well as an inorganic fiber and an inorganic nonwoven fabric comprising the ceramic material, and methods of producing the fiber and fabric. Moreover, the present invention also relates to a composite material that comprises the inorganic fiber or inorganic nonwoven fabric as a reinforcing material.
2. Description of the Prior Art
Conventionally, glass fiber and carbon fiber are the most widely known reinforcing materials for composite materials. In particular, carbon fiber reinforced plastic (CFRP) exhibits superior levels of strength and elastic modulus to steel or glass fiber reinforced plastic (GFRP), and also offers superior mechanical properties.
However, in recent years, as a result of the demands to reduce the consumption of crude oil due to factors such as global warming caused by carbon dioxide and the sharp rise in the cost of crude oil, reductions in the weight of all manner of components is becoming necessary. If the quantity of CFRP or the like is reduced in order to meet these demands for weight reduction, then the strength of the resulting product tends to be unsatisfactory. In this manner, these reinforcing materials are unable to satisfy all the required properties.
Composite materials of carbon fiber and a light metal such as aluminum have been investigated as potential improvements to the situation described above, but the wetting properties of carbon fiber and a light metal are poor, and the light metal and carbon may undergo reaction at high temperatures, causing a deterioration in the strength.
On the other hand, the silicon-based fiber developed by Yajima et al. in 1975 exhibits favorable wetting with light metals, good heat resistance, and does not suffer from the problem of reaction between the light metal and the fiber at high temperatures causing a deterioration in the strength. Furthermore, methods in which a polycrystalline silicon carbide fiber is produced from an organopolysiloxane are also being investigated. However, a high temperature treatment of at least 1,600° C. is required to produce these types of fibers, and moreover, because these fibers contain phenyl groups, the Si/C elemental ratio is low, and the carbon loss ratio during heat treatment is high, meaning they face problems in terms of conserving resources, and from an economic perspective.
In recent years, methods have been proposed for preparing ultra fine silicon-based fibers by conducting fiber spinning of polymer blends. In these methods, two raw materials are used, namely a polycarbosilane that functions as a silicon precursor to the silicon-based fiber, and a resin that disappears by thermal decomposition as a matrix. Specifically, the silicon precursor is dispersed and mixed within the resin that disappears upon thermal decomposition, melt spinning is then conducted, and a heat treatment is then conducted. In the methods that use these raw materials, large quantities of hydrogen are generated during the production process, meaning safety can be problematic (patent references 1 and 2).
A method has also been proposed in which carbon fiber is reacted with silicon monoxide gas to generate silicon carbide fibers, and the resulting fibers are then subjected to heat treatment. This method requires a gaseous phase reaction to be conducted under conditions of reduced pressure and high temperature, meaning a simpler method would be more desirable (patent reference 3).
Exhaust gases discharged from vehicles and industrial machinery and the like cause atmospheric pollution, and are attracting considerable attention. Particularly in the case of diesel engine vehicles, the removal of NOx and suspended particulate matter comprised mainly of carbon is a significant issue.
Against this type of background, a large variety of different exhaust gas purification devices have been proposed. A typical exhaust gas purification device for a diesel engine is a structure in which a casing is provided partway along the exhaust pipe connected to the engine exhaust manifold, and a filter having very fine apertures formed therein is then disposed within this casing, but the material for this filter suffers from cracking caused by temperature fluctuations and dissolution loss (patent reference 4). In order to overcome these problems, exhaust gas purification devices that use either a metallic nonwoven fabric (patent reference 5) or a silicon carbide-based nonwoven fabric (patent reference 6) as the filter have also been proposed. However, because these materials are short fibers, the material strength tends to be low, and the methods are also extremely expensive due to raw material synthesis problems that require the synthesis of a polysilane from dimethyldichlorosilane, followed by the synthesis of a polycarbosilane or polytitanocarbosilane.
[Patent Reference 1] EP 0435065 A1
[Patent Reference 2] JP 2004-360115 A
[Patent Reference 3] JP 7-18520 A
[Patent Reference 4] JP 6-92753 A
[Patent Reference 5] U.S. Pat. No. 5,908,480
[Patent Reference 6] JP 2004-60096 A

Amorphous inorganic ceramic material and method of producing same


Brassica plants producing oils with a low alpha-linolenic acid content and methods for producing such plants are described.

Canola oil contains a relatively high (8%-10%) alpha-linolenic acid (ALA) content. This trienoic fatty acid is unstable and easily oxidized during cooking, which in turn creates off-flavors of the oil. It also develops off odors and rancid flavors during storage (Hawrysh, 1990, Stability of canola oil, Chapter 7, pp. 99-122 In: F. Shahidi, ed. Canola and Rapeseed: Production, Chemistry, Nutrition, and Processing Technology, Van Nostrand Reinhold, N.Y.). Reducing the ALA content level by hydrogenation increases oxidative stability of the oil. However, hydrogenation results in the production of trans fatty acids, which increases the risk for coronary heart disease when consumed. Although an oil's oxidative stability is not determined solely by fatty acid profile, a decrease in the ALA content of canola oils generally improves the stability of the oils.


The invention provides a method and system for fast scheduling using a work-conserving Round Robin strategy. The method and system select one of a plurality of queues of data packets for switching it to an output port in a current timeslot, for achieving work-conserving Round Robin scheduling. The method is based on a consideration range for each queue that is a set of queues having priority over the given queue. The method comprises the steps of generating a mask for a given queue for masking all queues outside a consideration range of the given queue and applying the mask and a queue ready flag for the given queue for determining if the given queue is to be selected in the current time slot.

Round Robin (RR) is a well-known strategy for scheduling multiple requests for a common resource, see e.g. "Operating Systems—a Modern Perspective" by G. Nutt, 2nd edition, published by Addison Wesley Higher, Jul. 18, 2001. If there are K contenders for a resource then RR allocates the resource to each of the contenders for a fixed duration (called time slice) at a time. When the time slice allocated to the current contender "i" is over, the resource is allocated to the next contender "i+1" and so on. The allocation of the resource is performed in a circular fashion. It is allocated to contender 1 first followed by 2 and so on. When the time slice for contender K is over, the resource is allocated to contender 1 again. At a given point in time, the contenders for a resource may or may not be ready for using the resource. If a resource is allocated to a contender when its turn arrives, irrespective of whether or not the contender is ready, the strategy is called non-work-conserving round robin; whereas if a resource is allocated to a contender if and only if it is ready, the strategy is called a work-conserving round robin.
RR has been used in a number of different situations including switching of data arriving at multiple queues to a common outgoing port. A typical implementation of such an RR strategy is based on the well-known priority encoder principle (also known as daisy chaining principle), see e.g. "Digital Design Principles and Practices 2nd Edition" by John F. Wakerly published in 1994 and 1990, Prentice-Hall, Inc. Englewood Cliffs, N.J. However the delay achieved with such an approach is directly proportional to the number of contenders. Thus the delay achieved with a high number of queues that are to be multiplexed to an outgoing port may become too high for use in a high-speed data switching system.

Fast work-conserving round robin scheduling


This invention is related to a self-service vision screening kiosk that allows individuals to screen their eyesight without assistance. The device includes subjective and/or objective tests via an interactive video and software program that measures visual acuity and contrast sensitivity. The invention is designed to provide a report with test results. The device and method may also provide a means for making referrals, scheduling appointments, ordering lenses, dispensing lenses and/or forwarding prescriptions to eye care professionals or lens manufacturers.

An estimated 164 million Americans require some form of vision correction. In 1999, only about 52 percent of persons needing vision correction purchased eyewear, leaving 48 percent, who purchased nothing.
The American Optometric Association recommends that a patient visit an optometrist every 1-2 years because eyesight can deteriorate slowly, making self-diagnosis difficult. Less than thirty percent of Americans that are age 40 and over realize the importance of regular eye exams. Two major reasons why consumers fail to visit their optometrist regularly are based upon convenience and belief that their vision remains static.
Additionally, some sectors of the general population are unable to participate in a typical exam performed in doctors' offices. For example, some consumers have special needs and may not comprehend the Snellen test. Other consumers, such as very young children may not be able to differentiate letters, numbers or other shapes used to diagnose vision defects. Other consumers may fear the expense of a lengthy eye exam in countries that require an exam for a vision correction prescription. Still consumers may experience a language barrier that makes a Snellen or refractive exam difficult or impossible.
Some countries do not require prescriptions for corrective lenses; however, individuals who do not know their sphere and cylinder corrections cannot accurately determine which lenses to order. Additionally, in some countries, eye care professionals may not be accessible to all individuals. In these countries, some individuals requiring vision correction may not have access to 1) methods to indicate the type and power of vision correction needed and 2) methods to obtain vision correction.

Automated vision screening apparatus and method


A rear facing light bar for a passenger vehicle comprises a housing shaped to define a rearwardly directed roof extension which increases in depth in the downstream direction. The housing is permanently attached to the vehicle and supports, behind an outer lens, a linear array of individually controllable lights which are rearwardly directed.

1. Field of the Invention
The present invention relates to the provision of a visual warning of the presence of a public safety vehicle to traffic which is following or overtaking that vehicle and, particularly, to improvements in and to warning light systems for employment on emergency vehicles. More specifically, this invention is directed to a rear-facing light bar, which spans substantially the entire width of a vehicle and includes a plurality of individually controllable light sources, and especially to a light bar which does not significantly increase the overall height or wind resistance of a vehicle on which it is installed. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
Attention attracting systems for increasing the visibility of police and other public service vehicles have long been known in the art. The most widely employed type of emergency vehicle visual warning system is the light bar. A typical light bar, as exemplified by the disclosures of U.S. Pat. Nos. 4,620,268 and 5,027,260, includes a plurality of light generators arranged on a support which spans from side-to-side, and either rests on or is spaced slightly above, the roof of the emergency vehicle. Light bars have the desirable ability to produce a wide variety of highly visible light radiation patterns. A light bar, however, possesses certain inherent disadvantages. Firstly, prior art light bars increase vehicle wind resistance and thus increase fuel consumption. Also, because of the turbulence created thereby, a conventional light bar will cause at least some increase in the ambient noise level and will thus have a negative effect on communications. Further, a light bar will increase vehicle height and this, in turn, may limit access to certain areas and/or present the possibility of damage to the light bar or property in situations where there is reduced overhead clearance. Perhaps most importantly, a light bar is a conspicuous addition to a vehicle and there are many situations where a law enforcement official does not wish his or her presence to be "announced" by a roof-mounted object, i.e., a light bar, when the warning lights on the vehicle are not energized.
The warning lights on an emergency vehicle, when energized, must unambiguously convey knowledge of the presence of that vehicle to on-coming traffic, to traffic being overtaken, to traffic approaching from the side at an intersection and to traffic which is following and/or overtaking the emergency vehicle, particularly when it is stopped. A light bar, because of its ability to project pulses of light which are directed forwardly, rearwardly and to the side of the vehicle on which it is installed, provides all of the necessary directional warnings. However, the warning of on-coming traffic and traffic which is being overtaken, as well as the warning of traffic which is moving at an acute or right angle to the path of an emergency vehicle, can be effectively accomplished by various combinations of grill or bumper mounted warning lights, headlight flashers, warning lights mounted inside the vehicle on the dash board, sun visors or rear-vision mirror and warning lights integrated with the externally mounted rear view mirrors such as disclosed in U.S. Pat. No. 5,660,457.
It is well known that traffic which is overtaking an emergency vehicle, particularly when the emergency vehicle is stationary, presents the greatest danger for a collision. Tail/back-up light flashers and rear bumper mounted warning lights, in part because such lights are located relatively close to the ground, do not provide as effective a warning to such overtaking traffic as is afforded by a conventional roof-mounted light bar. Additionally, such individual lights, even when operated in combination, do not have either the attention-attracting capability of or the ability to convey directional information possessed by a light bar which may house eight or more separately controllable high intensity light generators.
To summarize the foregoing discussion, there has been an unsatisfied demand for a rear-facing warning light system which would possess all of the advantages of the conventional light bar without the above-discussed disadvantages thereof.


A three-dimensional universal unit includes multiple identically configured assembly units, each having a central unit body, arms that can rotate relative to the unit body, the arms extending from the unit body in three orthogonal axes and having a connecting mechanism at the end of each arm. The assembly unit also has an information processing unit for controlling a motor in the unit body, an assembly unit operation, a rotary drive transmission system for transmitting arm drive motion from the motor, and a drive transmission system for engaging and disengaging the connecting mechanisms. Each connecting mechanism can mechanically connect with a connecting mechanism of another assembly unit and includes a communication device for exchanging information between information processing units of connected assembly units.

1. Field of the Invention
The present invention relates to a universal unit for automatically configuring three-dimensional structures of a desired shape using only internally incorporated mechanisms. More particularly, the invention relates to a three-dimensional universal unit that can be used to configure automatically three-dimensional structures of a required shape such as three-dimensional structures located in extreme environments such as space, by making, breaking and reconfiguring connections among a plurality of identically structured assembly units without external assistance.
2. Description of the Related Art
In structures formed by connecting together many identical assembly units, changing the connective configuration, breaking connections and reconfiguring the assembly units, connecting, disconnecting and reconfiguring assembly units are normally made with the assistance of an external force. However, in extreme environments such as in outer space as well as in restricted spaces and the like where such an external helping force is not readily obtainable, such connection, disconnection and reconfiguration are difficult. Concerning this technical problem, multifunctional modules for mechanical configurations are disclosed in U.S. Pat. No. 5,452,199.
Structures formed by these modules are two-dimensional in shape. The modules each have an information processor and use electro-magnets to form connections with other modules, change the positions of connections, break connections by generating repulsive force. This capability enables the overall two-dimensional shape of a structure to be changed by sequentially changing connective relationships among neighboring modules. Thus, a structure of a desired two-dimensional shape can be formed by starting out from a desired two-dimensional connective configuration and changing the connective relationships. However, the ability to change two-dimensional shapes has very limited applicability. Instead, what is generally required is the ability to form desired three-dimensional structural configurations.
An object of the present invention is to provide a three-dimensional universal unit for forming three-dimensional structures in a desired shape. This object is accomplished by a plurality of assembly units that are able automatically to connect together as well as disconnect and reconfigure connections to self-assemble into the required three-dimensional structure.

Universal unit for automatically configuring three-dimensional structures of a desired shape

Agency of Industrial Science & Technology, Ministry of International Trade & Industry


The disclosure relates to a synchronously playing method and device of a media file, and a storage medium, the method includes: creating a media source object corresponding to a playing window in a webpage through a player embedded into the webpage; adding different tracks in the fragmented media file into the same source buffer object in the media source object; transmitting a virtual address taking the media source object as a data source to a media element of the webpage; calling the media element to parse the media source object associated with the virtual address, and reading the tracks in the source buffer object of the associated media source object, and decoding and playing the tracks.

The Moving Picture Experts Group (MPEG)-4 format is a widely used box format that can store video data and audio data in a variety of encoding modes.
A player embedded in a browser plays contents by using media elements of a Hyper Text Markup Language (HTML) 5 of the browser. The player plays a media file through a webpage of the browser or a webpage of an application (APP) embedded into a browser kernel. However, the related technology is inadequate for supporting the playing of the media file, so a problem that videos and audios are asynchronous occurs in the play process.

Synchronously playing method and device of media file, and storage medium

Beijing Bytedance Network Technology Co., Ltd.


The invention relates to a device for controlling the temperature of objects, especially for drying or cooling objects, said device comprising a housing containing at least two tempering units which are arranged in a functionally parallel manner. Each tempering unit comprises a tunnel-type usable space in which tempered air is applied to the objects. Said objects can be displaced through the usable spaces by means of a respective transport system. According to the invention, the at least two tempering units are superimposed in the housing essentially above the same base surface.

The invention relates to an apparatus for thermally conditioning objects, in particular vehicle bodies, comprising
a housing;
at least two thermally conditioning facilities which are arranged parallel in their operation, are accommodated in the housing and each comprise
ba) a tunnel-like useful space, in which the objects can be impinged by thermally conditioned air;
bb) a conveying system, by which the objects can be moved through the useful space.
The term "thermally conditioning" is used in the present case as a generic term for all ways in which the temperature of the air by which objects are to be impinged is adjusted to a specific value. Thus, "thermally conditioning" can mean, for example, "heating", which is of importance particularly when the apparatus is designed as a drier. However, "thermally conditioning" can also be "cooling" if the objects are to be brought to a lower temperature.
Apparatuses of the type mentioned at the outset are known from the market in the automotive industry, where painted vehicle bodies or body components are to be dried or cooled. To increase the drying or cooling capacity, a plurality of parallel-arranged thermally conditioning facilities, i.e. drying or cooling facilities, are frequently employed, these being guided either in each case as "individual tubes" through separate housings or, lying one beside the other, through one and the same housing. However, the space requirement of these known apparatuses is relatively high.

Device for controlling the temperature of objects


A well completion process for improved cement placement in a horizontal wellbore where a fluid is circulated down the wellbore for conditioning and cleaning it. Afterwards, a production tube containing centralizers is positioned centrally within the wellbore. Next, a "spacer fluid" is circulated within an annulus formed by the space between the tube and the wellbore so as to clean the annulus out. Subsequently, a cement having a density greater than the spacer fluid is pumped into the annulus. Thereafter, a light weight cement is pumped into the annulus thereby overriding the heavier cement and removing voids in the annulus resulting in more efficient cement placement.

With advances in drilling technology, it is currently possible to drill horizontal wellbores deep into hydrocarbon producing reservoirs. There are many advantages to a horizontal well completion including extending contact with a producing formation thereby facilitating drainage and production of the reservoir.
Although horizontal wellbores allow more contact with the producing formation, one encounters some difficulties in well completions associated with horizontal wellbores not commonly dealt with in vertical wells. One area of concern in well completions is the inability to effectively cement voids along the horizontal section during a cementing operation. Effective cementing of the tubing to the wellbore is routinely accomplished in vertical wellbores. However, in horizontal wellbores and severely inclined wellbores, i.e. those having an angle of deviation greater than about 45.degree., cementing is much more difficult. Therefore, the efficiency of zone isolation diminishes considerably.
In oil and gas well completions it is imperative to effectively isolate the oil or gas bearing formation from other zones in the wellbore. This is most frequently accomplished by cementing the production casing in place and then perforating the wellbore in the production horizon to allow hydrocarbon flow into the wellbore. With effective cementing, flow up the outside of the production casing is eliminated and the oil and/or gas producing zone is effectively isolated.
Often a failure of the cementing operation occurs in horizontal wellbores because the density of the cement does not allow sufficient displacement of drilling mud and other residue from the tubing/wellbore annulus, thereby resulting in channeling of cement and improper tubing or pipe/formation bonding.
Therefore, what is needed is a method for improving the effectiveness of the cementing operation in deviated or horizontal wellbores which allows the removal of void spaces in the horizontal section due to incomplete displacement of wellbore materials and the effects of gravity on high density cement.

Method for improving cement placement in horizontal wells


A tag for concealing in an object for providing antitheft protection and identification, and a system for incorporating the tag, include in one embodiment a magnetic antitheft element, and an identification code including a pattern of first and second segments of wires of high thermal conductivity situated at right angles to the antitheft element and in intimate thermal contact with the antitheft element. The length of the first segments is longer than the length of the second segments.

Systems are known for the prevention of theft of articles, e.g., books from libraries and products from stores, which generally comprise a marker element attached to the article and instruments adapted to sense a signal produced by the marker upon its passage through an interrogation zone. Typically the marker is a magnetic wire or strip and the interrogation zone is provided by transmitter antenna coils which generate an alternating magnetic interrogation field in the zone. The marker is driven into and out of saturation which disturbs the alternating magnetic interrogation field and produces alternating magnetic fields at frequencies which are harmonics of the alternating magnetic interrogation field. The harmonics are detected by receiver antenna coils, which are frequently housed in the same structure as the transmitter coils, which in turn are processed by electronic processing means to produce alarm signals.
On a more sophisticated level, for retail tagging, tagging used in the road/air-freight package industry, and pallet tagging in manufacturing processes, a tag (also known as an "identification tag", "marker" or "label") is useful for identifying a product or article in detail. Such tags include bar code labels and radio frequency tags based on silicon memory and logic circuits (also known as RFID tags). By providing the tag with a sufficient number of bits and interrogating the tag, the tag can provide information such as what the product is, when it was manufactured, its price, and whether the product has been properly passed through a check-out counter or kiosk. Tags can also be used to identify a variety of other animate and inanimate objects too numerous to mention. Identifying a product via an RFID tag may hasten a new type of checkout system for the retail industry giving rise to a so-called "no-wait checkout".
The present technology used for magnetic tags which are widely used for anti-theft purposes has several drawbacks when extended to multibit capabilities including that relatively large sized markers result. In addition, there are problems due to the method of the tag's operation which prevents them from being solidly embedded. An example of a large multi-bit marker is the tag of Pettigrew et al., U.S. Pat. No. 4,940,966. Pettigrew et al. describe a tag having a limited number of bits which includes a plurality of soft magnetic strips mounted on a substrate, biased by adjacent strips of hard magnetic material. Typical spacing between strips is on the order of one centimeter with some strip lengths greater than 4 cm. Here, each element or strip defining a bit must have dimensions that differ from one another in order to give them a distinct characteristic, here being a unique hysteresis curve.
The magnetic multibit tag described by Dames and Hyde (U.S. Pat. No. 5,420,569) uses magneto-mechanical coupling to cause resonances characterized by planar dimensional changes and enhanced magnetization of the strip elements. This tag is both large and has the disadvantage that the strip needs to be free-standing in order to resonate and therefore cannot be embedded.
The systems described above all have the capability of being interrogated remotely. In addition, there are means for storing many bits of information per unit area using magnetic stripes on items like credit cards. However, this type of storage device requires either direct or very close proximity of the reading head to the object and can be easily tampered with by use of a hard magnet. Furthermore, magnetic stripes cannot serve as a remotely sensed antitheft device.
There is a widespread problem with theft in many industries, e.g., in the computer industry where there is theft of both computer parts and components and entire computers. The theft is difficult to detect and if recovered after the theft, the recovered items are difficult if not impossible to identify. Thus, what is needed in addition to an anti-theft device is a means to identify the owner along with important data such as the warranty date. It is therefore important to 1) provide a means for preventing theft by concealing a type of sensor that can sound an alarm to an externally located receiver and 2) provide a set of elements that yield a code upon local interrogation, the elements being concealed and personalized to permit identification of the object should it be stolen and recovered.

Anti-theft and identification devices for concealing in articles


According to an embodiment, a signal processing device includes an integrator, a first analog-to-digital converter, and a histogram creator. The integrator is configured to integrate an electrical charge corresponding to electromagnetic waves. The first analog-to-digital converter is configured to perform an analog-to-digital conversion operation that generates digital data of the electrical charge using an integration output from the integrator, on a parallel with an integration operation performed by the integrator. The histogram creator is configured to create a histogram that represents an energy distribution of the electromagnetic waves, from the digital data generated by the first analog-to-digital converter.

These days, a photon counting computed tomography (CT) device is known in which a detector that implements the photon counting technique is used. Unlike an integral-type detector, a detector implementing the photon counting technique outputs signals that enable individual counting of X-ray photons that have passed through a test subject. Hence, in a photon counting CT device, it becomes possible to reconstruct X-ray CT images having a high signal-to-noise ratio (SN ratio).
Besides, the signals output by a detector implementing the photon counting technique can be used in measuring (differentiating) the energy of the X-ray photons. Hence, in a photon counting CT device, imaging can be done by dividing projection data, which is collected by bombarding X-rays of one type of X-ray tube voltage, into a plurality of energy components.
As a detector implementing the photon counting technique, an "indirect-conversion-type detector" is known in which the incident X-ray photons are temporarily converted into a visible light (a scintillator light) using a scintillator and then the scintillator light is converted into electrical signals (an electrical charge) using an optical sensor such as a photomultiplier tube. Herein, the optical sensor individually detects each scintillator photon obtained by conversion of radiation by the scintillator, and then detects the radiation falling on the scintillator and measures the energy of that radiation.
In recent years, development of silicon-based photomultipliers is being actively pursued. Moreover, there has been development regarding weak-light detection systems such as a detector that implements the photon counting technique using a scintillator and a photomultiplier. In that regard, further development is being carried out with the aim of enhancing the performance.
In a conventional weak-light detection system, the electrical charge that is output from a photomultiplier is integrated by an integrated circuit for a predetermined period of time and is converted into a voltage. Then, the voltage is subjected to sampling/holding and AD conversion (analog-to-digital conversion) in that order. Subsequently, digital signal processing is performed with respect to the obtained digital signals and a histogram is created.
In such a conventional weak-light detection system, the count rate of the electrical charge (i.e., the count rate of the scintillation photons) is limited due to the AD conversion time. In order to achieve a high count rate, it is desirable to implement a high-speed AD conversion method such as the flash method. However, since a high-speed AD conversion method such as the flash method requires a lot of comparators, it leads to an increase in the circuit area and the power consumption. Hence, in the present situation, it is difficult to implement a high-speed AD conversion method.
Particularly, in a photon counting CT device, the count rate of the X-rays falling on a scintillator is estimated to be, for example, about 108 cps (counts per second). For that reason, there is a demand for the development of a reading circuit capable of measuring high-speed and high-energy data at a high resolution in a simultaneous manner in a few hundred channels. However, as described earlier, a high-speed AD conversion method such as the flash method requires a lot of comparators, thereby leading to an increase in the circuit area and the power consumption. Hence, it is difficult to implement a high-speed AD conversion method. Consequently, using the currently available reading circuits, it is difficult to perform measurement in a simultaneous manner in a few hundred channels.

Signal processing device and signal processing method


A process for the recovery of a perfluorosulphonic acid ionomer from a component comprising a perfluorosulphonic acid ionomer is disclosed, the process comprising immersing the component comprising the perfluorosulphonic acid ionomer in a solvent comprising an aliphatic diol and heating. Also disclosed is the use of the recovered perfluorosulphonic acid ionomer, for example in to prepared a proton conducting membrane or a catalyst ink.

A fuel cell is an electrochemical cell comprising two electrodes separated by an electrolyte. A fuel, e.g. hydrogen, an alcohol such as methanol or ethanol, or formic acid, is supplied to the anode and an oxidant, e.g. oxygen or air, is supplied to the cathode. Electrochemical reactions occur at the electrodes, and the chemical energy of the fuel and the oxidant is converted to electrical energy and heat. Electrocatalysts are used to promote the electrochemical oxidation of the fuel at the anode and the electrochemical reduction of oxygen at the cathode.
Fuel cells are usually classified according to the nature of the electrolyte employed. Often the electrolyte is a solid polymeric membrane, in which the membrane is electronically insulating but ionically conducting. In the proton exchange membrane fuel cell (PEMFC) (which also includes the direct methanol fuel cell (DMFC)) the membrane is proton conducting, and protons, produced at the anode, are transported across the membrane to the cathode, where they combine with oxygen to form water.
A principal component of the PEMFC is the membrane electrode assembly (MEA), which is essentially composed of five layers. The central layer is the proton conducting membrane. On either side of the proton conducting membrane there is an electrocatalyst layer, containing an electrocatalyst designed for the specific electrolytic reaction. Finally, adjacent to each electrocatalyst layer there is a gas diffusion layer (GDL). The GDL must allow the reactants to reach the electrocatalyst layer and must conduct the electric current that is generated by the electrochemical reactions. Therefore, the GDL must be porous and electrically conducting.
The electrocatalyst layers generally comprise an electrocatalyst comprising a metal or an alloy suitable for the fuel oxidation or oxygen reduction reaction, depending on whether the layer is to be used at the anode or cathode. The electrocatalyst is typically based on platinum or platinum alloyed with one or more other metals. The platinum or platinum alloy catalyst can be in the form of unsupported nanoparticles (such as metal blacks or other unsupported particulate metal powders), or can be deposited as higher surface area particles onto a conductive carbon substrate or other conductive material (a supported catalyst), or can also be in the form of an extended thin film material, such as those disclosed in, for example, WO2013/144631A1.
The electrocatalyst layers also generally comprise a proton conducting material, such as a proton conducting ionomer, to aid transfer of protons from the anode catalyst to the membrane and from the membrane to the cathode catalyst.
Conventional proton conducting membranes used in PEMFCs are generally formed from perfluorinated sulphonic acid (PFSA) ionomers and the membranes formed from these ionomers are sold under the trade names Nafion® (DuPont), Aquivion® (Solvay Specialty Polymers), Flemion® (Asahi Glass KK) and Aciplex® (Asahi Kasei). Alternatively, the proton conducting membrane may be based on a sulphonated hydrocarbon membrane such as those available from FuMA-Tech GmbH as the fumapem® P, E or K series of products, JSR Corporation, Toyobo Corporation, and others.
The proton conducting membrane may be a composite membrane, wherein the membrane contains other materials that confer properties such as mechanical strength. For example, the membrane may contain a porous reinforcing material, such as an expanded polytetrafluoroethylene (e-PTFE) material.
The proton conducting membrane may also comprise one or more components which assist the chemical durability of the membrane, for example a hydrogen peroxide decomposition catalyst, a radical scavenger etc.
Conventionally, the MEA can be constructed by a number of methods outlined hereinafter:
(i) The electrocatalyst layer may be applied to the GDL to form a gas diffusion electrode (GDE). A GDE is placed on each side of an ion-conducting membrane and laminated together to form the five-layer MEA;
(ii) The electrocatalyst layer may be applied to both faces of the proton conducting membrane to form a catalyst coated membrane (CCM). Subsequently, a GDL is applied to each face of the CCM.
(iii) An MEA can be formed from an ion-conducting membrane coated on one side with an electrocatalyst layer, a GDL adjacent to that electrocatalyst layer, and a GDE on the other side of the proton conducting membrane.
Typically, tens or hundreds of MEAs are required to provide enough power for most applications, so multiple MEAs are assembled to make up a fuel cell stack. Field flow plates are used to separate the MEAs. The plates perform several functions: supplying the reactants to the MEAs; removing products; providing electrical connections; and providing physical support.


A screw insertion instrument includes a housing, a knob, a drive shaft, and a screw alignment post. The housing includes a proximal portion and a distal portion, and the proximal portion includes a proximal body portion defining a channel extending longitudinally therethrough along a longitudinal axis of the housing. The knob is coupled to the proximal portion of the housing and defines an aperture therethrough that is aligned with the longitudinal axis of the housing. The drive shaft extends through the aperture of the knob and the proximal portion of the housing. The screw alignment post is coupled to the distal portion of the housing and is aligned with the longitudinal axis of the housing.

The spinal column is a complex system of bones and connective tissues that provide support for the human body and protection for the spinal cord and nerves. The adult spine includes an upper portion and a lower portion. The upper portion contains twenty-four discrete bones, which are subdivided into three areas including seven cervical vertebrae, twelve thoracic vertebrae, and five lumbar vertebrae. The lower portion includes the sacral and coccygeal bones. The cylindrical shaped bones, called vertebral bodies, progressively increase in size from the upper portion downwards to the lower portion.
An intervertebral disc along with two posterior facet joints cushion and dampen the various translational and rotational forces exerted upon the spinal column. The intervertebral disc is a spacer located between two vertebral bodies. The facets provide stability to the posterior portion of adjacent vertebrae. The spinal cord is housed in the canal of the vertebral bodies. It is protected posteriorly by the lamina. The lamina is a curved surface with three main protrusions. Two transverse processes extend laterally from the lamina, while the spinous process extends caudally and posteriorly. The vertebral bodies and lamina are connected by a bone bridge called the pedicle.
The spine is a flexible structure capable of a large range of motion. There are various disorders, diseases, and types of injury, which restrict the range of motion of the spine or interfere with important elements of the nervous system. The problems include, but are not limited to, scoliosis, kyphosis, excessive lordosis, spondylolisthesis, slipped or ruptured disc, degenerative disc disease, vertebral body fracture, and tumors. Persons suffering from any of the above conditions typically experience extreme and/or debilitating pain, and often times diminished nerve function. These conditions and their treatments can be further complicated if the patient is suffering from osteoporosis, or bone tissue thinning and loss of bone density.
Spinal fixation apparatuses are widely employed in surgical processes for correcting spinal injuries and diseases. When the disc has degenerated to the point of requiring removal, there are a variety of interbody implants that are utilized to take the place of the disc. These include interbody spacers, metal cages, and cadaver and human bone implants. In order to facilitate stabilizing the spine and keeping the interbody implant in position, other spinal fixation apparatuses are commonly employed, such as bone screws and spinal rods to connect the interbody implant with the cranial and caudal vertebrae. In complex spine cases, such as scoliosis, and minimally invasive surgical procedures, it is often challenging to insert bone screws and align them with a spinal rod.
Therefore, a need exists for a system that easily and reliably implants a bone screw and captures a spinal rod for complete reduction of the spinal rod into a saddle of the bone screw.

Surgical system for bone screw insertion and rod reduction


In a magnetic resonance imaging apparatus, an RF pulse is applied to a subject placed in a static magnetic field, a plurality of gradient magnetic fields are applied, and induced nuclear magnetic resonance signal (echo signal) is received by means of a RF receiving coil unit composed of two or more RF receiving coils. A parallel MRI method is applied to echo signals acquired by reducing the echoes per blade of a propeller MRI method so as to remove the artifact to produce a reconstructed image. The reconstructed image is subjected to inverse Fourier transform to return it to the echo signals in a measurement space corresponding to the blade. The echo signals are girded in an arbitrarily predetermined coordinate system for image and combined. Such a processing is conducted for the echo signals of all the blades. A final image is reconstructed using the echo signals after the image creation in the coordinate system for image.

For an MRI apparatus, the Cartesian sampling method for taking samples along trajectories parallel to the orthogonal coordinate axis of the k-space is often used as a scheme for acquiring echo signals on the k-space needed for image reconstruction. However, a method referred to as non-Cartesian sampling for taking samples along trajectories that are not parallel to the orthogonal coordinate axis of the k-space has been receiving attention in recent years, and one example is the PROPELLER sampling method (reference: Yasushi Watabe et al, "Atarasii Ragiaru Sucan: PROPELLER-hou", INNERVISION (17•9) 29-31, 2002)
According to the PROPELLER sampling method, a unit region (hereinafter, referred to as the blade) comprising plural parallel trajectories having the origin of the k-space in between is given as one unit, and echo signals corresponding to almost the entire region of the k-space are measured by rotating blades about the origin of the k-space. Within each blade, plural echo signals are acquired by applying a phase encoding pulse as with normal measurements by the Cartesian sampling method.
Also, the parallel imaging method is used as a technique for shortening an imaging time needed for the MRI apparatus. According to the parallel imaging method, a multiple receiver coil formed by combining plural high-frequency receiver coil units (hereinafter, referred to as RF receiver coils) having local, inhomogeneous sensitivity distributions that differ from coil to coil is used, and echo signals at each RF receiver coil are measured by skipping phase encoding steps. Then, aliasing artifacts occurring on respective reconstructed images are removed using sensitivity distribution data of each RF receiver coil. This can reduce the number of echoes needed to reconstruct a single image, which can in turn shorten an imaging time by reducing the repetition number of times of the pulse sequence.
However, when the parallel imaging method is applied to the PROPELLER sampling method as above, it is necessary to remove aliasing artifacts by applying the generalized aliasing artifact development algorithm to the data of the entire k-space that has been measured by skipping, and this need extends a computation time considerably.
The reference cited above is silent about the application of the parallel imaging method to the PROPELLER sampling method and the problems arising in such a case as discussed above.

Magnetic resonance imaging method and apparatus


To provide a transmission apparatus and a communication system that transmit a plurality of transmission signals riding on different interfering transmission beams, separate and receive the transmission signal at the receiving side, and estimate the original transmission signal by maximum likelihood estimation based on the correlation among the received signals. A transmission apparatus which encodes the transmission signal by an encoding means to generate at least two transmission signals S1 and S2, modulates the signals to the carrier frequencies, weights them and supplies them to the antenna elements, and controls the weights to transmit the modulated output signals by beams partially overlapping each other in space. A reception apparatus which separates and receives the transmission signals by a channel adaptive antenna to receive at least two received signals RS1 and RS2 and estimates the original transmission signal using maximum likelihood estimation, for example, a Viterbi decoding algorithm, based on the correlation between the received signals so as to reduce the error rate of the received signal and realize an improvement of the quality of communication.

In recent years, in mobile communication, there has been a demand for efficient communication in both space and time from the viewpoint of dealing with different communication capacities between uplinks and downlinks, that is, so-called non-symmetrical channels, the simplification of hardware at the mobile station side, and the improvement of the efficiency of utilization of the frequency. Particularly, in view of the adoption of W-CDMA (wide band code division multiple access) as a wireless access scheme for the next generation mobile communication system IMT2000, transmission diversity using a plurality of antenna elements, adaptive antenna arrays using a plurality of antenna elements, and other systems have been proposed as powerful technologies for increasing the capacities of the W-CDMA system.
However, in the prior art described above, there has been almost no study relating to the correlation of the transmission signals due to the interference among beams in the case of transmission by a plurality of transmission beam at the transmitting side. Further, the correlation of the transmission signals due to the interference among beams has not been utilized actively to improve the communication efficiency and to improve the quality of communication. Thus, in the case of transmitting and receiving signals by forming a plurality of beams, that is, so-called space diversity, the interference among beams has almost always been suppressed as much as possible to suppress interference and the correlation of transmission signals has not been utilized effectively.

Transmission apparatus, transmission method, communication system, and method of same


A belt device that is provided with an endless belt having a projection on an inner surface of the endless belt, the projection extending parallel to a running direction of the endless belt; and a support roller having a guide member that contacts the projection, the support roller supporting the endless belt so as to run the endless belt, wherein the guide member is separately provided from the support roller and nonrotatably supported between the support roller and the projection.

1. Field of Invention
The invention relates to a belt device that supports an endless belt with a support roller so as to run, and an image forming apparatus provided with the belt device.
2. Description of Related Art
There exists an image forming apparatus that includes a belt device that transports a recording medium on an endless belt inside the image forming apparatus. As disclosed in, for example, Japanese Laid-Open Patent Publication No. 2001-163424, a belt device includes a protrusion that is provided on an inner surface of an endless belt. The protrusion extends along a running direction of the endless belt to prevent the endless belt from being out of position while the endless belt is running.
However, in the belt device, the protrusion formed on the endless belt runs onto a support roller supporting the endless belt while the endless belt is running. To solve such a problem, the belt device disclosed in Japanese Laid-Open Patent Publication No. 2001-163424 includes a rotating member that has a tapered surface and is disposed concentrically with the support roller and is provided between the protrusion and the support roller. As the tapered surface of the rotating member contacts the protrusion, meandering of the endless belt is restricted and the protrusion is prevented from running onto the support roller.
In the belt device, meandering of the endless belt while the belt is running under normal conditions is restricted by the rotating member having the tapered surface. However, when an external force is applied to the endless belt, the protrusion runs onto the rotating member along the tapered surface of the rotating member while the rotating member is being rotated. Thus, the protrusion readily runs onto the rotating member.


A sleeve bearing comprising two thrust-bearing parts wherein one thrust-bearing part surrounds the other. The two thrust-bearing parts extend essentially parallel to one axis and are braced against each other by a resilient member made of rubber elastic material. The resilient member defines at least one pair of fluid-filled chambers which are connected by at least one damping opening and are arranged so that they diametrically oppose one another. The chambers are bounded in the axial direction on both sides by end walls, which are elastically deformable in one partial area. Each end wall has a rigid zone which resists deformation. At one end of each fluid chamber, the rigid zone of the end wall extends to the inner thrust-bearing part, and at the other end of each fluid chamber, the rigid zone of the end wall extends to the outer thrust-bearing part.

The present invention relates generally to a sleeve bearing comprising two thrust-bearing parts, wherein one thrust-bearing part surrounds the other. The two thrust-bearing parts extend essentially parallel to one axis and are braced against each other by a resilient member made of rubber elastic material. The resilient member defines at least one pair of fluid-filled chambers, wherein the chambers are connected by at least one damping opening and are arranged so that they diametrically oppose one another. The chambers are bounded in the axial direction on both sides by end walls, which are elastically deformable in one partial area.
A sleeve bearing with hydraulic damping is disclosed by the European Patent Office application 0 009 120. It comprises a number of pairs of fluid-filled chambers, wherein the chambers are arranged on mutually opposing sides of a plane through the axis of the bearing and one behind another along the direction of the axis. The chambers are in fluid communication with one another through damping openings, which are independent of one another. In this manner, vibrations which are introduced at right angles to the axis and vibrations which are introduced parallel to the axis are able to be damped effectively. However, manufacturing such a sleeve bearing entails a considerable expenditure.

Hydraulic damper elastomeric body having alternating rigid and deformable wall sections


Provided is a projection-type image display apparatus in which dust collected on a filter can be removed more efficiently. The projection-type image display apparatus includes an image projection section configured to generate and project an image, a cabinet section that houses the image projection section in an interior and is provided with at least one or more air inlets, a passage section through which outside air taken in from the air inlet flows, a filter section provided in the passage section, an impact application section that strikes the filter section, and a control section that controls the impact application section so as to strike the filter section at a timing when the filter section vibrating by striking of the impact application section is moving toward the impact application section.

A projection-type image display apparatus (what is called a projector) in which light emitted from a light source is modulated by a display element and the light after modulation is enlarged and projected on a projection surface by a projection optical system is known as an example of display apparatuses.
In such a projection-type image display apparatus, a mechanism that takes in air from the outside is provided in order to cool optical members included in the optical system, the light source, and the display element. Further, in the air intake mechanism, a filter that collects dust is provided at an air intake port or an air passage in order to prevent dust from entering the interior of the projection-type image display apparatus due to air intake.
Here, in a case where the filter that collects dust is used for a long period of time, the filter undergoes clogging due to collected dust, and the resistance to the flow of intake air (what is called the pressure loss) is increased. In such a case, in the projection-type image display apparatus, the flow rate of air taken in from the outside is reduced, and hence cooling efficiency for each configuration of the interior is reduced.
Thus, for example, Patent Literature 1 below discloses a projection-type video display apparatus in which the clogging of a filter is suppressed by applying vibration to the filter by means of a vibration application section and shaking off dust collected on the filter.

Projection-type image display apparatus, filter apparatus, control apparatus, and control method


The present invention is directed to a method and apparatus for sharing content between a content source device and a remote device. The content source device is connected to a mobile device that communicates with the remote device using a wireless network. The mobile device is used to facilitate the sharing of content with the remote device. The content shared with the remote device is formatted for its use by either the content source device or the mobile device. The present invention is directed to a wireless content sharing system that may include a content source device that supplies the content, a mobile device to facilitate the sharing of content, and a remote device to receive the content.

Wireless communications devices are continually evolving toward higher data rates. While the basis until recently has been approximately 9.6 Kbps for circuit switched connections, the rates are increasing rapidly. Packet switched connections such as Global Packet Radio Service (GPRS) can lead to 28.8 Kbps or higher. With newer technologies such as Enhanced Data rates for Global Evolution (EDGE) and the Universal Mobile Telecommunications System (UMTS) data rates will evolve through 384 Kbps and continue upwards.
With these higher data rates, it becomes possible using wireless communications devices to send and receive many types of content such as web pages, images, music, voice, text, graphics, software, audio, video, or multimedia. The concept of a wireless Internet becomes attractive as does streaming audio, video, multimedia, and other information with these higher data rate equipped communications devices.
What is needed is a method and apparatus that will allow a user having a wireless communications device to take advantage of these higher data rates to share content located on a device such as a personal computer or laptop with another user having a wireless communications device.

Method and apparatus for sharing content with a remote device using a wireless network


Ophthalmic surgical blades are manufactured from either a crystalline or polycrystalline material, preferably in the form of a wafer. The method comprises preparing the crystalline or polycrystalline wafers by mounting them and machining trenches into the wafers. Methods for machining the trenches, which form the bevel blade surfaces, include a diamond blade saw, laser system, ultrasonic machine, a hot forge press and a router. The wafers are then placed in an etchant solution which isotropically etches the wafers in a uniform manner, such that layers of crystalline or polycrystalline material are removed uniformly, producing single, double or multiple bevel blades. Nearly any bevel angle can be machined into the wafer which remains after etching. The resulting radii of the blade edges is 5-500 nm, which is the same caliber as a diamond edged blade, but manufactured at a fraction of the cost. The ophthalmic surgical blades can be used for cataract and refractive surgical procedures, as well as microsurgical, biological and non-medical, non-biological purposes.

1. Field of the Invention
The invention relates to ophthalmic and other types of surgical and non-surgical use blades. More particularly, the invention relates ophthalmic, micro-surgical and non-surgical blades manufactured from silicon and other crystalline materials.
2. Description of the Related Art
Existing surgical blades are manufactured via several different methodologies, each method having its own peculiar advantages and disadvantages. The most common method of manufacture is to mechanically grind stainless steel. The blade is subsequently honed (through a variety of different methods such as ultrasonic slurrying, mechanical abrasion and lapping) or is electrochemically polished to achieve a sharp edge. The advantage of these methods is that they are proven, economical processes to make disposable blades in high volume. The greatest disadvantage of these processes is that the edge quality is variable, in that achieving superior sharpness consistency is still a challenge. This is primarily due to the inherent limitations of the process itself. Blade edge radii can range from 30 nm to 1000 nm.
A relatively new method of blade manufacture employs coining of the stainless steel in lieu of grinding. The blade is subsequently electrochemically polished to achieve a sharp edge. This process has been found to be more economical than the grinding method. It has also been found to produce blades with better sharpness consistency. The disadvantage of this method is that the sharpness consistency is still less than that achieved by the diamond blade manufacturing process. The use of metal blades in soft tissue surgery is prevalent today due to their disposable cost and their improved quality.
Diamond blades are the gold standard in sharpness in many surgical markets, especially in the ophthalmic surgery market. Diamond blades are known to be able to cleanly cut soft tissue with minimal tissue resistance. The use of diamond blades is also desired due to their consistent sharpness, cut after cut. Most high-volume surgeons will use diamond blades since the ultimate sharpness and sharpness variability of metal blades is inferior to that of diamond. The manufacturing process used to make diamond blades employs a lapping process to achieve an exquisitely sharp and consistent edge radius. The resultant blade edge radii range from 5 nm to 30 nm. The disadvantage of this process is that it is slow and as a direct result, the cost to manufacture such diamond blades ranges from $500 to $5000. Therefore, these blades are sold for reuse applications. This process is currently used on other, less hard materials, such as rubies and sapphires, to achieve the same sharpness at a lesser cost. However, while less expensive than diamonds, ruby and/or sapphire surgical quality blades still suffer from the disadvantage that the cost of manufacture is relatively high, ranging from $50 to $500, and their edges only last through about two hundred cases. Therefore, these blades are sold for reuse and limited reuse applications.
There have been a few proposals for the manufacture of surgical blades using silicon. However, in one form or another, these processes are limited in their ability to manufacture blades in various configurations and at a disposable cost. Many of the prior proposals are based on anisotropic etching of silicon. The anisotropic etching process is one where the etching is highly directional, with different etch rates in different directions. This process can produce a sharp cutting edge. However, due to the nature of the process, it is limited by the blade shapes and included bevel angles that can be attained. Wet bulk anisotropic etching processes, such as those employing potassium hydroxide (KOH), ethylene-diamine/pyrcatechol (EDP) and trimethyl-2-hydroxethylammonium hydroxide (TMAH) baths, etch along a particular crystalline plane to achieve a sharp edge. This plane, typically the (111) plane in silicon <100>, is angled 54.7° from the surface plane in the silicon wafers. This creates a blade with an included bevel angle of 54.7°, which has been found to be clinically unacceptable in most surgical applications as too obtuse. This application is even worse when this technique is applied to making double bevel blades, for the included bevel angle is 109.4°. The process is further limited to the blade profiles that it can produce. The etch planes are arranged 90° to each other in the wafer. Therefore, only blades with rectangular profiles can be produced.
Thus, a need exists to manufacture blades that address the shortcomings of the methods discussed above. The system and method of the present invention can make blades with the sharpness of diamond blades at the disposable cost of the stainless steel methods. In addition, the system and method of the present invention can produce blades in high volume and with tight process control. Further, the system and method of the present invention can produce surgical and various other types of blades with both linear and non-linear blade bevels.

This patent is subject to a terminal disclaimer.

Silicon blades for surgical and non-surgical use


A delay locked loop (DLL) is provided. Within this DLL is a watchdog circuit that determines whether harmonic lock is present. Based on this measurement, the watchdog circuit can provide adjustments to the DLL so as to change the length of the delay of the delay line to bring it within a predetermined range.

Referring to FIG. 1 of the drawings, the reference numeral 100 generally designates a conventional DLL. DLL 100 generally comprises a phase detector (PD) 102, a charge pump 104, a loop filter 106, and a delay line 108 (which includes a set of buffers 110-1 to 110-n). In operation, DLL 100 is supposed to lock so that total delay D of the delay line 108 is approximately equal to period of the reference clock signal REF. Lock is achieved with the help of PD 102; however, PD 102 is generally limited to operating under the condition that the delay D is between 0 and twice the period of the reference clock signal REF. If delay D is outside of this range, DLL 100 can potentially to lock to other multiples of the period of the reference clock signal REF (harmonic lock) and can cause functional failure. Thus, there is a need for a circuit to generally ensure that the delay remains in a predetermined range.
An example of another conventional DLL is U.S. Pat. No. 6,977,605.

Simplified, extendable, edge-based watchdog for DLL