A method and system for information delivery of a computer system. The method includes the steps of storing a first data including a program and potentially reusable data on a storage medium of a computer system. In turn, a second data including control data is subsequently stored on the same storage medium as the first data. The contents of the control data is unknown at the time the first data was stored. The control data corresponds to a subset of the potentially reusable data. The program is executed and combines the control data and the potentially reusable data to create on the storage medium of the computer system a third data including newly indexed available information. Information is delivered by sending a plurality of transmissions where known data is sent in advance to minimize the subsequent delivery of unknown control data that becomes known based upon a future event.

As technology progresses in the digital age, there has been the continued challenge to serve the growing and changing information needs of society. Technology has constantly reinvented new ways of utilizing data by optimizing the space and time necessary for the storage, transfer, compilation, and arrangement of information. Methods of data delivery have included the compression and/or ciphering of data sent via floppy diskette, compact disc (CD-ROM), or e-mail and by receiving data from centralized sources such as the Internet, Bulletin Board System (BBS), or other on-line services.
A variety of recent advances in data delivery methods are known such as: metering the on-site usage of licensed software on fixed media; remote installation of software upgrades; and data on-demand services which offer novel ways for optimizing customized data distribution to subscribers. The common focus of these methods is splitting and recombining information in order to achieve more progressive solutions for data delivery. However, due to subscription data size and limited end user technology to support such information, the commercial data vendor in an effort to manage profit and control achieves delivery by maintaining an on-line centralized database where the subscriber uses a centralized information delivery program to download information from and have conditional access to.
Such centralized information delivery programs rely on a fairly extensive library of known desired data. As a result, new data with references not listed in the original library files are unknown to the subscriber. Thus, the reference libraries require frequent updates to remain current with the new data. If the information provider is lax in providing updates, or the subscriber is lax in obtaining and employing available updates, the centralized information delivery program may become obsolete within only a few months after installation. Furthermore, the centralization of information oftentimes results in placing greater demands on data search engines. For example, when querying from a centralized data source, substantially all of the data is searched by the search engine in order to perform retrievals. Such an exhaustive search may result in a longer period of time for the search engine to complete its task.
On-line databases, since their inception, have been the most desirable way to access information from large bodies of data. This was especially the case in the early 1980's when off-line desktop storage was at a premium and data transmission speed was slow. Lobby power helped influence the defining of boundaries between the government's mission of information dissemination and issues of competition with the private sector. The Reagan administration issued a proposal to prevent government agencies from providing on-line access, restricting the federal role of government to that of a wholesaler. Monopolies were forged with select commercial data vendors in the private sector to provide access to public information. Few could afford the expense of buying data up-front for the luxury and privacy of having unlimited searching and retrieval of this information off-line. As a result, searching and retrieval have been limited to either strictly on-line systems or strictly off-line systems. The introduction of CD-ROM, has allowed providers to distribute discs that contain summaries or abstracts of the full document, and reach a larger market at a better price. Although files with frequent updates are not best suited CD-ROM, this advance helped the subscriber search off-line and decide what documents were to be ordered. Compact discs have marked a clear beginning for a hybrid search and retrieval system to evolve and bring both together.
Such is the case in the area of patents. In exchange for disclosure of an invention, the issuance of a U.S. patent is a twenty year grant from the time filed by the government of a property right to the inventor to `exclude others from making, using, or selling the invention`, with the patentee losing rights to the invention upon expiration. Title 37 Code of Federal Regulations (CFR), Section 1.362(d) provides that maintenance fees may be paid without surcharge for the six-month period beginning three, seven, and eleven years after the date of issue of patents based on applications filed on or after Dec. 12, 1980. An additional six-month grace period is provided by 35 U.S.C. 41(b) and 37 CFR 1.362(e) for payment of the maintenance fee with the surcharge set forth in 37 CFR 1.20(h), as amended effective Dec. 16, 1991. If the maintenance fee is not paid in the patent requiring such payment the patent will expire on the fourth, eighth, or twelfth anniversary of the grant. Eleven years since the first premature patent expiration in December 1985, over 275,000 patents have prematurely expired and entered the public domain with an additional 1,000 patents prematurely expiring each week.
The most common use of patent information and an early step in assessing the patentability of an invention is to perform prior art searches of existing patents. To assist patent examiners, the Automated Patent System (APS) was implemented in April of 1984 by the U.S. Patent and Trademark Office (PTO) with over 400 million dollars of taxpayer money to provide sophisticated centralized on-line search capabilities. By accessing the APS database from a computer, an examiner can select patents for review based on the occurrence of specified words or phases, in particular combinations, in the document. The U.S. Congress has long recognized the importance of information dissemination to the PTO's mission. The PTO enabling legislation has several sections addressing information dissemination; the most relevant of these being the requirement that the PTO provide the public with direct access to its search systems. Consequently, the APS database has been available to the public in the PTO Public Search Room since 1990 and, initially on an experimental basis, in 14 of the 74 Patent and Trademark Depository Libraries since 1992.
Virtually all information concerning the content of U.S. patents offered by commercial data vendors is based on data furnished by the PTO. At present, the most prevalent mode of transferring data to the vendor community from the PTO is in the form of files on magnetic tape. For example, the PTO offers copies of the tapes that contain the text used as input in the building of the APS database. The premature expiration of a patent has never been a search requirement for the patent examiner. As a result, there has been no need for the PTO to incorporate this new reference information into the APS database. Currently, the APS database is the representation of the original library files of patent text data at the time of issuance and does not provide a data field for the premature expiration status of a patent. Even though this is the primary source of data provided for sale by the PTO, commercial data vendors in turn have not recognized the potentially unrealized value of premature expiration information.
It is the government's responsibility to publish what the public can not make, use, or sell. Aside from disclosure of the full patent document, the government also publishes the front page information of the patent document in the Official Gazette. The following is from Chapter 2575 of the Manual of Patent Examining Procedure (MPEP) Sixth Edition, Revision 1, September 1995.
A notice will appear in each issue of the Official Gazette which will indicate which patents have been granted 3, 7, and 11 years earlier, that the window period has opened, and that maintenance fee payments will now be accepted for those patents. Another Official Gazette notice published after expiration of the grace period will indicate any patent which has prematurely expired due to nonpayment of maintenance fees and any patents which have been reinstated. An annual compilation of such expirations and reinstatements will also be published.
This passage denotes the intention of the government to publish what the public can make, use, or sell. All patents prior to December 1985, expire seventeen years after being granted. For example, if it is the first week of the year 1996 and the public wanted to read what patents had just expired, one would look at the Official Gazette from the first week of 1979. Essentially a book published exactly seventeen years ago would be retrieved. For the first 195 years of the U.S. Patent System, there was no need to republish or compile expired patent information because it was previously published by default.
On Dec. 10, 1985, nearly 200 years since the first patent issued, the Official Gazette (OG) Notice had listed Pat. No. 4,291,808 to become the first patent ever to prematurely expire for failure to pay maintenance fees. Since then, the PTO has published weekly in the OG notices the patent numbers of the expiring patents. The release of the patent numbers only, limits the public to a manual, exhaustive, and inefficient cross-referenced retrieval of the newest patent documents that have prematurely expired, thereby creating for the first time a new need to compile this information. In 1990, the PTO released a series of CD-ROM subscription products including the Classification and Search Support Information System Bibliographic disc (CASSIS-BIB). This disc offers the search and retrieval of title-only patent information dating back to 1969. The subscriber can search for the status of a patent (withdrawn, reinstated, abandoned, or prematurely expired) and view the most current list of premature expired patents. Although the release of the CASSIS-BIB disc can help with the search of patent expirations and allows the subscriber the privacy and cost benefits of such a system, searching is limited to patent titles only, the disc is updated every two months and is not cost effective to update more frequently.
Because of significant changes in technology, revisions to the Office of Management and Budget (OMB) Circular A-130, and the passage of the Paperwork Reduction Act of 1995 (Public Law 104-13), public access has further expanded through a variety of programs administered by the PTO's Office of Information Dissemination to include the access of patent and trademark information made available via the Internet and PTO Bulletin Board System (PTO-BBS). Upon browsing Internet sites, patent servers at the Center for Networked Information Discovery and Retrieval (CNIDR), Community of Science, Chemical Abstracts Society (CAS), and IBM to name a few, have all neglected to allow searching for the expiration status of a patent. The IBM Patent Server has come closest to this accomplishment where on Jun. 4, 1997, a maintenance status field was integrated into the database which lists the status of a patent upon retrieval only, and is not yet a searchable field.
In November of 1994 the PTO established an on-line BBS. The PTO began to list exclusive files of premature expired patent numbers weekly and list master files of premature expired patent numbers every two months. The patent numbers are published in natural ascending order, and for more than ten years have been keyed in manually by the PTO. As a result, it is not uncommon to see occasional errors like the reversal of digits within the patent number based on an operator's manual entry. In 1995, the PTO added the release of the OG Notices on-line. In the OG Notice on Feb. 6, 1996, the PTO published the premature expired patent numbers for the week of Feb. 13, 1996 instead of the current week. On Mar. 12, 1996 the OG corrected the omission while the PTO-BBS did not. Since then, the exclusive files have been reported one week ahead of the OG Notices upon issue. The master list of premature expired patent numbers released on the PTO-BBS for Dec. 31, 1996 omitted about 6,000 premature expired patent numbers. This omission represents the eight and twelve year expirations since the previous master list on Oct. 31, 1996. This omission is in turn reflected in the December 1996 issue of the CASSIS-BIB CD-ROM. There were further omissions in the February 1997 issue and the CASSIS-BIB subscription disc does not remain corrected to this date. In May 1997, the PTO-BBS shut down due to a diminished user base and the increasing popularity of the Internet. The above inconsistencies indicate that there is no system for detecting error or omission that may be subject to manual labor or clerical errors. The issuance of the premature expired patent numbers by the PTO has now become questionable in regard to method, policy, and accuracy of its use.
The conditions of centralization first mentioned have allowed for industry to overlook novel solutions for the dissemination of newly available information. Accordingly, in light of the above, there is a strong need in the art for a novel system and method for updating information/reference files of a computer and/or computer system without putting the onus of updating on the subscriber so that an information program stored thereon is kept current. Moreover, there is a strong need to improve a system and method to optimize the search, retrieval, reporting, delivery, and update of master database information and newly available information for both on-line and off-line systems.

Method and system for periodically updating data records having an expiry time


A voltage regulator includes an undervoltage detector having a charge transistor smaller than an output transistor of the voltage regulator, providing a detection path for fast response, compensating undervoltage without large control current when loading changes from light to heavy.

1. Field of the Invention
The invention relates to a voltage regulator, and in particular to a voltage regulator having fast response to abrupt load transients.
2. Description of the Related Art
FIG. 1 shows a voltage regulator as disclosed in U.S. Pat. No. 6,201,375. The voltage regulator 100 comprises an error amplifier 102, an output transistor (power NMOS transistor) 104, a feedback circuit comprising resistors R1 and R2, a comparator 106, a transistor (NMOS transistor) 108 and an output capacitor CL. The voltage source 105 is the input offset voltage VOFS of the comparator 106. The comparator 106 and the NMOS transistor 108 form a local load transient suppression loop which specially deals with a load condition while the voltage regulator 100 suffers from heavy load to light load. When loading of the voltage regulator 100 changes from heavy to light, the output regulated voltage VOUT suffers an abrupt rise (or overvoltage). Hence, the feedback voltage VFB is also increased. When the feedback voltage VFB exceeds the sum of the reference voltage VREF and the input offset voltage VOFS, the comparator 106 turns on the NMOS transistor 108 to sink currents, thereby reducing the overvoltage of the output regulated voltage VOUT. More particularly, when the output voltage VOUT exceeds the reference voltage VREF by a voltage
            V      OFS        ×                            R          1                +                  R          2                            R        1              ,the load transient suppression loop is activated to control the overvoltage of the output regulated voltage VOUT.
Generally, electronic systems adopting a voltage regulator are more sensitive to undervoltage of the regulated output voltage than overvoltage of the regulated output voltage. The voltage regulator suffers undervoltage of its output regulated voltage when its loading changes from light to heavy. For example, the output regulated output VOUT of the voltage regulator 100 is supplied to an electronic system (not shown in FIG. 1). When the electronic system is in a power-off or standby state, i.e. with a light load, the output transistor 104 outputs a considerably small current. When the electronic system switches to a power-on state, i.e. with a heavy load, the voltage regulator 100 must supply large current to the electronic system. However, the output transistor 104 cannot supply current suddenly to satisfy the large current requirement, and thus the voltage regulator 100 cannot respond rapidly enough to compensate the output undervoltage of the output regulated voltage VOUT.
Generally, in order to increase current supplied from the output transistor 104, the gate voltage of the output transistor 104 should be pulled up by the feedback loop path of the voltage regulator 100, through the feedback circuit (R1 and R2), the error amplifier 102 and the output transistor 104. Unfortunately, transient response of the feedback loop path is very slow due to compensation stability. In addition, the output transistor 104 (power NMOS transistor) is often large and thus has a large gate capacitance, resulting in speed limitation when charging the gate voltage of the output transistor 104. An added buffer stage with increased bias current may speed the response of the output transistor 104, but current consumption of the voltage regulator 100 is then increased and feedback loop delay still remains.

Voltage regulator having fast response to abrupt load transients


Data is collected related to motion of a vehicle. Based on the collected data, it may be determined that a threshold associated with motion sickness is exceeded. An adjustment for a component in the vehicle may be adjusted based at least in part on the collected data.

Many people experience motion sickness when riding in a vehicle. For example, bumpy or hilly roads, potholes, curves, stop-and-start motion, etc. may cause some people to experience motion sickness. Further, motion sickness may be caused and/or exacerbated for a vehicle occupant by other factors. For example, reading a book, viewing a video, and over-hot climate, etc., may induce or heighten feelings of dizziness, nausea, etc. Attempts to alleviate motion sickness may involve taking medication, not consuming media such as books or video, looking out a window at a distant point, etc. However, further mechanisms for addressing in-vehicle motion sickness are wanting.


A shoe cover for covering a shoe to present the look like the wearer is wearing a different pair of shoes. The shoe cover includes an upper piece configured to cover the shoe of a wearer, the upper piece sized to cover a specific shoe without being attached to the shoe while the shoe is worn. The shoe cover includes a sole piece coupled to a bottom of the upper piece and configured to grip surfaces as the wearer uses the shoe cover and a gripping insert secured within the cavity created of the upper piece to guard against slippage of the cover on the shoe with the intent of ensuring the safety of the wearer.

Shoes serve several purposes. The first is utilitarian. Shoes protect ones feet. The second is style. Having shoes that match outfits, or at least complement one's daily wardrobe, is very much a part of looking stylish. Given our present-day style consciousness, women are buying more shoes than even before. It is estimated by the ECommerce fashion industry that both women's shoe sales and accessory sales will double between 2018 and 2022, indicating women are increasingly interested in having their feet fashionably dressed.
Every woman wants a pair of classic pumps for dress and ballerina slippers (otherwise known as 'my flats') for shopping and general comfort. These popular styles are commonly bought in beige and/or black in order to coordinate with most of the clothes in their closets.
Shoes come not only in every size, but also at every price. Serviceable shoes exist at $25.00 and $2,500, and at all prices there between. Women mostly buy the shoes they can afford, and, very often these days, skimp somewhere in the budget to purchase that extra pair to match a special outfit.
There have been some patents granted for changing the appearance of shoes.
Lin (U.S. Pat. No. 6,349,486) reveals a sandal comprised of a sole and two straps. The straps can be exchanged using a complex fastening device embedded in the sole. Difficulties attendant upon the device exist in addition to the limitation of this application: two-strap sandals.
Bauer (U.S. Pat. No. 4,377,042) reveals a complicated athletic shoe with a removable out-sole. The shoe includes an upper portion designed to fit an individual foot and ankle of a particular wearer, and is permanently attached to the insole. The outsole and insole are connected together by mating hook and pile members. Bauer does not attach the upper portion directly the sole base without an insole. Its purpose is to serve the athlete, not the fashion conscious woman.
Hartung (U.S. Pat. No. 5,983,528) uses a fastening device (a zipper), which attaches the upper to the sole, and extends at least partially around the peripheral region of the sole to form a barrier between the joining device and the interior space of the shoe. It is a complicated and unsightly device.
Bailey (U.S. Pat. No. 4,887,369) uses fasteners for attaching the shoe top to the shoe bottom. This again poses the introduction of a third element—as do the others—which is a system that can fail as well as an additional expense. Costly fastening systems diminish the value of utilizing the footwear.
All of the above-mentioned patents represent systems with third element attachments that are neither fail-safe nor cost effective.


The present invention provides a displacement detection apparatus uses short scales and can provide a long measurable range comparable to a single long scale with a short bed length. The displacement detection apparatus includes a scale, a first head and a second head adapted to detect periodic analog signals of a plurality of different types, a first processing section and a second processing section that detects the first differential value and the second differential value between the immediately preceding positional data and the current positional data obtained by sampling the periodic analog signals of a plurality of different types, a switching section that selectively switches from the first differential value to the second differential value or vice versa, a scale position detection section that detects the scale getting to a predetermined position relative to the first head or a predetermined position relative to the second head, a switching control section that causes the switching section to switch from either of the differential values to the other in response to the detection of the scale getting to the predetermined position, and an addition section that adds the first differential value or the second differential value selectively switched by the switching control section and outputting it as positional information.

1. Field of the Invention
This invention relates to a displacement detection apparatus for detecting the relative position of a moving apparatus, which may be a machine tool, an inspection apparatus or a semiconductor manufacturing system.
2. Description of the Related Art
Displacement detection apparatus for detecting the relative position of a moving apparatus, which may be a machine tool or a semiconductor manufacturing system, are known. Such a displacement detection apparatus comprises a scale on which a periodic signal having a constant wavelength is recorded in a predetermined direction with a fluctuating signal level, a head section for detecting the periodic signal recorded on the scale and a processing section for processing the periodic signal detected by the head section and outputting positional information. The scale and the head section are fitted to respective members of a movable section and a reference section that are adapted to move relative to each other. With the displacement detection apparatus, the head section detects the periodic signal whose signal level fluctuates on the scale in response to the relative movement of the two members and supplies the detected periodic signal to the processing section. The processing section by turn outputs positional information that indicates the relative positions of the relatively moving two members according to the periodic signal detected by the head section.
Known displacement detection apparatus include those having a single scale and a single head section. FIGS. 1A through 1D of the accompanying drawings schematically illustrate a known displacement detection apparatus mounted on a machine tool that is driven to move linearly. On the machine tool, the single head 100 of the displacement detection apparatus is arranged in a central part of a bed 101, which is a stationary member, and vis-à-vis a scale 102, which will be described in greater detail hereinafter. The scale 102 is arranged longitudinally under a table 103, which is a movable member adapted to move linearly either in the direction of arrow A from left L to right R or in the direction of arrow B from right R to left L, and vis-à-vis the head 100. The scale 102 and the head 100 may be a magnetic scale and a magnetic modulation type magnetic head or an optical scale and an optical head.
FIG. 1A illustrates a situation where the table 103 is moved relative to the head 101 in the direction of arrow B and the scale 102 is located at its left marginal position. The head 100 is located vis-à-vis the right side end of the scale 102. FIG. 1B illustrates a situation where the table 103 is moving in the direction of arrow A and located vis-à-vis a central part of the bed 101 and hence the scale 102 is also located vis-à-vis a central part of the bed 102. Accordingly, the head 100 is located vis-à-vis the middle point of the scale 102. FIG. 1C illustrates a situation where the table 103 is moved further relative to the head 101 in the direction of arrow A and the scale 102 is located at its right marginal position. The head 100 is located vis-à-vis the left side end of the scale 102. FIG. 1D illustrates a situation where the scale 102 is located at its left marginal position relative to the head 100 as overlapped on a situation where the scale 102 is located at its right marginal position relative to the head 100. The bed 101 has a length (bed length: BL) twice as long as the measurable length ML of the scale 102.
Japanese Patent Application Laid-open Publication No. 10-239105 (Patent Document 1) discloses a displacement detection apparatus that is a magnetic scale apparatus formed by lining a plurality of magnetic scales and adapted to take out phase modulation signals by means of a pair of integrally incorporated magnetic transducers.
FIG. 2 schematically illustrates a magnetic scale apparatus as disclosed in the Patent Document 1. Referring to FIG. 2, a magnetic scale substrate 110 carries thereon a magnetic scale 111 realized by using a magnetic medium formed on a strip-shaped plate and a signal having a constant wavelength λ is recorded on the magnetic scale 111. A magnetic transducer 112 formed by using a pair of magnetic modulation type magnetic heads is fitted to a bed and arranged vis-à-vis the magnetic scale 111.
Referring again to FIG. 2, another magnetic scale substrate 113 has a configuration similar to that of the magnetic scale substrate 110. A magnetic transducer 114 formed by using a pair of magnetic modulation type magnetic heads is fitted to a bed and arranged vis-à-vis the magnetic scale substrate 113. The two magnetic scale substrates 110 and 113 are linked to each other so as to be used as a long scale. The two magnetic transducers 112 and 114 are also integrated with each other to form a head section 115.
The pairs of magnetic heads of the two magnetic transducers 112 and 114 are supplied with an excitation signal from an excitation circuit 116. The pairs of magnetic heads of the two magnetic transducers 112 and 114 are connected respectively to a first detection circuit 117 and to a second detection circuit 118. Each of the first detection circuit 117 and the second detection circuit 118 detects the phase modulation signal taken out in response to the relative positional change of the corresponding magnetic transducer relative to the corresponding magnetic scale and carries out an interpolation process on the signal before outputting it. Output circuit 119 selectively outputs the output of one of the detection circuits to provide positional information.
FIG. 3 schematically illustrates the positional relationship of the scale substrates 110 and 113 and that of the magnetic transducers 114 and 112 of the head section 115 of the above described magnetic scale apparatus. Assume here that the head section 115 is moving rightward relative to the scale substrate 110. While both of the magnetic transducers 114 and 112 provide outputs in the illustrated position, the output of the magnetic transducer 112 is selected for use.
As the magnetic transducer 112 comes into the link section 120 of the two scale substrates 110 and 113, the output of the magnetic transducer 112 is reduced so that the output circuit 118 switches from the use of the output of the magnetic transducer 112 to the use of the output of the magnetic transducer 114.
As the two transducers move further and the magnetic transducer 114 comes into the link section 120, the output of the magnetic transducer 114 is reduced this time but the magnetic transducer 112 has already moved out of the link section 120 and recovered the output so that the output circuit 118 switches from the use of the output of the magnetic transducer 114 to the use of the output of the magnetic transducer 112.
In this way, the above described magnetic scale apparatus avoids signal degradation in the link section 120 by selecting the output of the transducer that is providing a good output.


A reproduced signal from a recording medium 1 is equalized at partial response (1, 0, -1) by a reproducing equalizer 3, and is converted into a reproduced and equalized signal. A clock reproducing circuit 4 issues a reproduced clock synchronized with the timing of data identification, and applies it to a phase adjusting circuit 5. A phase control signal generating circuit 6A detects a specific pattern from a reproduced digital signal issued from an A/D converter 7, and the advance or delay amount of phase of the reproduced clock is detected by the amplitude or distribution of the sampling value. This phase deviation amount is given to the phase adjusting circuit 5 as a phase control signal. The phase adjusting circuit 5 given a delayed clock to the A/D converter 7, and controls to A/D convert the reproduced signal at correct timing.

The present invention relates to a data decoding apparatus for reproducing signals from a recording medium such as a magnetic tape, and obtaining video data or audio data.
As means for recording a data row into a magnetic recording medium, and reproducing the recorded signals and decoding into a same data row as before recording, a partial response system (hereinafter called PR) has been known. This is intended to equalize the reproduced signals to have an intersymbol interference, and identify the data row before recording from the signal corresponding to the multilevel. Hereinafter, a data decoding method employing PR (1, 0, -1) of which frequency characteristic is close to the magnetic recording system, as a kind of partial response, is described below.
In a magnetic recording medium, a data row after precoder shown in FIG. 1 is recorded. For example, an input data row . . . 001010 . . . is converted into . . . 001000. . . by the precoder, and recorded. Supposing D to be a delay operation of bit period, the reproduced signal from the magnetic recording medium is reproduced and equalized so that the frequency characteristic through recording and reproducing may be 1-D.sup.2, that is, the level subtracting the signal level of two bits before from the present signal level. It means that the reproduced signal from the magnetic recording medium in which the impulse . . . 001000 . . . may be equalized to . . . 0010-10 . . . .
The signal after being reproduced and equalized is as shown in the eye-pattern in FIG. 2A, in which the reference signal level at the data identification timing is a signal corresponding to three values of -1, 0 and +1. By identifying the signal level corresponding to +1 or -1 to be data "1" and the one corresponding to level 0 to be data "0," the original data row is decoded. Data decoding by partial response is briefly described herein, and the detail is narrated in the reference (Eto, Mita, Doi: Digital video recording technology, Nikkan Kogyo Shimbunsha, pp. 36-38, pp. 46-48).
As shown in FIG. 2A, the opening width of the eye-pattern in the time axis direction in the partial response system is narrower than in the conventional integral detecting method shown in FIG. 2B. Accordingly, due to the effects of the temperature characteristic of the clock reproducing section, if the clock phase showing the detection timing is deviated, the error rate deteriorates significantly. Accordingly, in order to control so that the detection timing may be stably positioned in the center of the opening of the eye-pattern (hereinafter called the eye center), a magnetic recording apparatus is proposed in Japanese Laid-open Patent No. 7-192404. This is intended to detect the phase deviation of the clock from the specific pattern contained in the reproduced digital signal, and control by feedback.
However, the pull-in time of the clock phase of the specific pattern is proportional to the frequency of the specific pattern contained in the reproduced digital signal. Accordingly, in such magnetic recording apparatus, the frequency of occurrence of the specific pattern is enhanced, and the recorded signal is processed by encoding, so that the pull-in time of the clock phase is shortened. In this case, the ratio of the effective data contained in the recorded data is lowered.
Without encoding process for enhancing the frequency of occurrence of the specific pattern, the ratio of the effective data is not lowered, but the pull-in time of the clock phase is extended. As a result, it causes to prolong the reset time to restore the favorable error rate in the discontinuous portion of reproduced signal, such as the head changeover section in the digital VTR or drop-out section derived from the flaw on the recording medium. It is also possible that the specific pattern does not occur for a long period, and the clock phase is deviated in that period, and the error rate deteriorates.
FIG. 6 is an explanatory diagram showing the relation between the detection timing and the distribution of reproduced and equalized signal in the eyepattern. When the initial clock phase is largely deviated from the eye center at time indicated by broken line (a) in FIG. 6, the clock phase may not be pulled into the eye center, and if pulled in, it takes a considerably long time.
The invention is devised to improve the problems of such prior art, and it is hence an object thereof to realize a data decoding apparatus capable of adjusting automatically so that the detection timing of reproduced clock may always come to the eye enter, and obtaining data of low error rate always stably, and not requiring redundancy of recorded data.

Matsushita Electric Industrial Co., Ltd.


This invention relates to novel reagent conjugates and a novel multi-step process for delivering active compounds to target analytes of interest in a patient for diagnostic and therapeutic purposes. According to the process, two novel reagents are bound to each other by linkage of the sequence-specific components they contain. The first reagent, which is comprised of a target recognition component and a first sequence-specific component, is introduced into the patient and allowed to achieve maximal localization on the target cells. The second reagent, which is comprised of an active compound component and a second sequence-specific component is then introduced into the patient, thereby forming a complex with the first reagent via the recognition and binding of the sequence-specific components of the two reagents to form the reagent conjugate of the invention. The active compound component is thereby efficiently and specifically delivered to the target analyte.

1. Field of the Invention
The present invention relates to novel reagents and methods which utilize a universal in vivo delivery system based on the use of polymer: polymer recognition and binding to deliver active compounds to target analytes for diagnostic and therapeutic purposes.
2. Brief Description of the Prior Art
Hormones (Varga, J. M., Asato, N., Lande, S, and Lerner, A. B. (1977) Nature 267: 56-58), lectins (Kitao, T. and Hattori, K. (1977) Nature 265: 81-82), and antibodies are among the reagents that have been employed as delivery agents in a variety of systems developed for the purpose of specifically delivering compounds to in vivo targets for diagnostic or therapeutic purposes. However, monoclonal antibodies are currently preferred. Recognition and delivery of therapeutic or diagnostic reagents using these antibodies has been accomplished through a single-step procedure in which the therapeutic or diagnostic reagent is directly conjugated to the monoclonal antibody. These conjugated monoclonal antibodies do not, however, represent a perfect delivery system. Monoclonal antibodies require a long period of time to reach equilibration with cell surface epitopes in vivo and may require up to several days to achieve optimal binding to a particular tissue (Primus, F. J., Wang, R. H., Goldenberg, D. M., et al. (1973) Cancer Res. 33: 2977-2982; Moshakis, V., McIlhinney, R. A. J., Raghavan, D., et al. (1981) Br. J. Cancer 44: 91-90). Thus, the use of monoclonal antibody delivery systems for radioimaging or therapeutic drug delivery, e.g., radioactively labeled monoclonal antibodies or drug-monoclonal antibody conjugates, may result in damage to untargeted tissues due to their lack of specificity and to the lengthy exposure times required. Clearance of these antibody conjugates may also result in some degree of kidney damage due to the large excess of these reagents that must be employed in order to achieve optimal results. In addition, the long equilibration period required for optimal monoclonal antibody binding precludes the use of short-lived radioisotopes in these delivery systems.
A major focus of current research has been to improve targeting of therapeutic or diagnostic reagents to internal target sites, such as to solid tumors or specific organs. One objective of this targeting is to enhance the effectiveness of these conjugated monoclonal antibody reagents by concentrating them at the target site, thereby minimizing their effects on non-target sites. For example, if a reagent is used for therapeutic purposes, such as to treat a solid tumor, improved targeting provides more effective dosing at the target site with fewer non-tumor related side effects. Similarly, where the reagent is a radionuclide used for radioimaging, improved targeting provides enhanced contrast between the target and background areas due to reduced background levels of the radionuclide. Another objective of this research has been to reduce the time required for delivery of the diagnostic or therapeutic reagent to target sites. This has been accomplished using a multi-step procedure in which antibody binding to target sites and reagent delivery are performed in separate steps. The advantage of such a procedure is that the targeting reagent can be allowed to equilibrate for a lengthy period of time without exposing the patient to a potentially harmful reagent. An equilibration period of one or more days will also result in greater specificity and lower backgrounds since excess targeting reagent is likely to be cleared during this period of time.
An example of a multi-step drug delivery procedure which has been used to deliver drugs to cells in vitro is disclosed in an article by Urdai and Hakomori (Urdai, D. L. and Hakomori S. I (1980) J. Biol. Chem. 255: 10509-10516). In this in vitro system, avidin was used as a bridge to link biotinylated, target-specific antibodies to either biotin-drug or biotin-drug-liposome drug carrier reagents.
Godfrey, et al. (Godfrey, W., Doe, B., Wallace, E. F., Bredt, B., and Wofsy, L. (1981) Experimental Cell Research 135: 137-45) also disclose the use of a biotin-avidin bridge to link antibodies to biotinylated drug-carrying liposomes or red blood cell ghosts in a similar multi-step in vitro assay for identifying specific types of cells.
Trubetskoy, et al. (Trubetskoy, V. S., Berdichevsky, V. R., Efremov, E. E., and Torchilin, V. P. (1987) Biochemical Pharmacology 36: 839-842) also recognized that a multi-step procedure results in a more effective delivery of therapeutic or diagnostic reagents to targets. The procedure they propose involves sequential administration of a targeting reagent, i.e., a biotinylated antibody which specifically recognizes and binds to the target site and which accumulates at the targeted tissue, followed by administration of avidin and a biotinylated liposome drug-carrying system which is capable of coupling specifically to the target-bound biotinylated antibody through the avidin bridge. The "bridge" molecules are defined by Trubetskoy as being bifunctional entities in that they have affinity for both the target binding reagent and the drug-carrying reagent. These "bridge" molecules can be "natural polyvalent macromolecules" which are "capable of binding two or more ligands, or synthetic conjugates obtained from molecules possessing two different types of affinty." In this paper the conjugate of the antibody, biotin, and avidin serves as the bridge between the target antigen and the biotinylated liposome, according to Trubetskoy. This system differs from one in which highly specific binding of arrays of like polymer units are used to link targeting and drug-carrying reagents.
In an alternate in vivo delivery system which employs biotin-avidin linkages, Goodwin, et al. (Goodwin, D. A., Meares, C. F., McCall, M. J. and McTigue, M., (1987) J. Nucl. Med. 28: 722) disclose a multi-step procedure wherein a conjugate comprised of streptavidin or avidin, a biotinylated EDTA chelate, and a radioactive metal (111In) is used to enhance the localization and delivery of the chelated metal isotope to the liver. This report further demonstrates the feasibility of using a lengthy equilibration period, i.e., 20-24 hours, for equilibration of the targeting entity, avidin, to the target tissue prior to addition of a biotinylated metal chelate complex. This system is further discussed in a subsequent publication by these workers (see, Goodwin, D. A. Meares. C. F., McCall, M. J. McTigue, M., Chaovapong, W., Levy, R. and Starnes, C. (1987) J. Nucl. Med. 28: 561), wherein the authors teach the use of a multi-step in vivo targeting system for mice in which monoclonal antibody-avidin conjugates are pre-equilibrated with target cells in vivo, then subsequently bound to biotinylated radioactive metal chelates prior to radioimaging. This paper also teaches the use of a clearing step with biotinylated human transferrin to remove excess monoclonal antibody-avidin conjugates from the blood. This system is more fully described in Eur. Pat. Pub. No. 0 251 494, published on Jan. 7, 1988, to Goodwin. D. A. Meares, C. and McCall, M. A drawback of this procedure is that high background levels result from the endogenous biotin present in the organism which can result in non-specific binding of the monoclonal antibody-avidin conjugate.
A different multi-step procedure which has been used to image murine tumors was disclosed by Goodwin, et al. (Goodwin, D. A., Meares, C. F., McCall, M. J., McTigue, M. and Chaovapong, W. (1988) J. Nucl. Med. 29: 226-234). In this procedure, antibody to a portion of a metal chelate complex was administered to mice and allowed to passively accumulate in the animal over a period of 20-24 hours. Excess antibody circulating in the blood was then removed by a brief chase with the antigen linked to human transferrin. Radioactively labeled chelate complexes were administered intravenously 1-3 hours before imaging. This procedure represents an improvement over previous radioimaging techniques because it allows for lengthy equilibration periods with a non-radioactive targeting agent, removal of excess targeting reagent, more rapid, specific, and efficient binding of chelated radioactive metals, and shorter periods of exposure to radioactive materials. However, its efficacy is reduced by the loss of antibody-bound chelated radioisotopes, since binding of these antibodies to metal chelates is very weak, resulting in weak signals and high background levels. Moreover, the antibodies are not specifically directed to a single organ, tissue, or cell type, further resulting in non-specific distribution of the radioactive chelate and high background levels.
The use of the above-described delivery systems for therapeutic or diagnostic reagents also presents a health hazard to the patient because high levels of such reagents must be used in these procedures. Thus, there is a need to develop a delivery system which exhibits high specificity for target sites, low background levels, and which also minimizes unnecessary exposure of patients to radioactive ions, or other hazardous materials.
A different type of bridging entity for use in a two-step universal in vitro system for detecting target analytes in a sample is taught in U.S. patent application Ser. No. 08/032,769, filed on Mar. 16, 1993, which is a continuation of U.S. patent application Ser. No. 07/607,787, filed on Oct. 26, 1990, now abandoned, which is a continuation of U.S. patent application Ser. No. 06/922,757, filed on Oct. 24, 1986, now abandoned, which is a Continuation Application of U.S. patent application Ser. No. 491,929, filed on May 5, 1983, now abandoned, both assigned to the instant assignee, which are incorporated by reference herein and made a part thereof. European Patent Application No. 84 10 5028.9-2110 was filed on May 4, 1984, based upon the priority document, U.S. patent application Ser. No. 06/491,929 (filed on May 5, 1983), and published as EP 0 128 332 A1 on Dec. 19, 1984. The European Patent Office issued a Communication under Rule 51(4) EPC on Aug. 20, 1994 indicating its intention to grant a patent thereon. In the first step of the process, a bridging reagent is administered and allowed to achieve binding equilibrium with the target. This reagent has two components. One of the components recognizes the target analyte. The other component is a polynucleotide that specifically recognizes and binds to a component in a second reagent. In the second step of the procedure, a signalling entity is added. This signalling entity also has two components. The polynucleotide component of the signalling entity binds rapidly and specifically to the complementary polynucleotide component of the first reagent, thereby forming a bridge between the two reagents of the invention. The other component of the second reagent is the signal generating compound of the reagent. Binding of the first reagent to the target, followed by binding of the two complementary polynucleotide portions of the first and second reagents to form the bridge, effectively delivers the signal generating compound to the target. In this reference sequence-specific polynucleotide components are used to rapidly and specifically link two reagents in a multi-step process for detection of target analytes in samples.
Thus, there is a need to develop an in vivo delivery system which exhibits high specificity for target sites, low background levels, and which also minimizes unnecessary exposure of patients to radioactive ions, or other hazardous materials. This type of targeted in vivo delivery system would represent a valuable tool for the diagnosis and treatment of a wide variety of disease states.

Method for in vivo delivery of active compounds using reagent conjugate


A winding core with improved beam and hoop strength and diminished friability and method for manufacturing such a core are provided, the winding core comprising: an extruded wood fiber core member; and at least one preformed paper shell member having a split seam parallel to its major axis, the shell being adhered to an exterior surface of the extruded wood fiber core member and a secondary shell of wooden staves.

Wood fiber cores are used to support rolls of various materials. Its limited beam strength and durability, however, have hindered its adoption in some industries like industrial belt winding, were the significant weight of the material wound about a core has traditionally been considered to require a steel core. Such steel cores are custom welded geographically close to the place where they will be used since they are bulky and awkward to transport. They are thus very costly.
Other industries, like light weight high tech non-woven materials have rejected such cores due to the friability of the wood fiber material. Dislodged material may damage the non-woven textile.
What is needed, therefore, are techniques for producing a light weight, non-friable, industrial core with a smooth exterior and high beam strength.

This patent is subject to a terminal disclaimer.


An OFDM receiver includes a demodulator unit being coupled to a received signal for demodulating both an in-phase (I) component and a quadrature-phase (Q) component of the received signal; a serial to parallel unit for converting the output of the demodulator to a plurality of parallel paths, each path corresponding to a particular tone and having a plurality of time-domain samples; a fast Fourier transform circuit for generating frequency domain samples from the time-domain samples; and a equalization and I-Q mismatch correction circuit being coupled to the fast Fourier transform circuit for performing both frequency domain equalization and I-Q mismatch correction on at least one frequency domain sample being output by the fast Fourier transform circuit.

1. Field of the Invention
The invention relates to a wireless communication system, and more particularly, to a receiver of the wireless communication system.
2. Description of the Prior Art
Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier transmission scheme used in high-speed data communications (e.g., both the IEEE 802.11a and 802.11g wireless LAN standards use OFDM). An OFDM transmitter utilizes a plurality of tones, also known as sub-carriers, which are sinusoidal waves and are orthogonal to one another. Each tone carries a certain bit-load of information using a certain modulation scheme, such as binary phase shift key (BPSK) that carries 1-bit of information, quadrature phase shift key (QPSK) that is also known as 4-QAM and carries 2-bits of information, 16-points quadrature amplitude modulation (16-QAM) that carries 4-bits of information, 64-points quadrature amplitude modulation (64-QAM) that carries 6-bits of information, and so on.
FIG. 1 shows a block diagram of a typical OFDM transmitter 100. In FIG. 1, N tones are utilized for transmission (labeled 0 to N−1). The input serial data is buffered and converted into N parallel data, labeled 0 to N−1 according to the respective bit at the serial in, parallel out (SIPO) buffer 101. A BPSK/QPSK/QAM mapper 102 encodes each of the N parallel data paths into a respective complex number, which represents the in-phase and quadrature components for its respective tone. An N-points Inverse Fast Fourier Transform (IFFT) module 104 is used to generate N time-domain complex samples (labeled 0 to N−1). The last NGI samples of the IFFT output are pre-pended to the beginning of the IFFT output. This process is referred to as "circular prefix" and is used to form a guard interval. Note that the guard interval is used to provide a time-domain buffer between adjacent OFDM symbols so as to improve the receiver's immunity to ISI (inter-symbol interference). The resultant (N+NGI) samples form an OFDM symbol, consisting of the superposition of N tones in time domain, each tone carrying its respective information. These samples are converted into serial time-domain samples in the subsequent parallel in, serial out (PISO) buffer 108.
The (N+NGI) serial time-domain samples are complex data, which can be separated into an in-phase component (real part) and a quadrature-phase component (imaginary part). Both components are converted to an analog signal at their respective digital-analog converter (DAC) 112, 118, resulting in an in-phase signal I(t) and a quadrature signal Q(t). A local oscillator (not shown) generates a quadrature carrier pair, cos(wt) and −sin(wt), which are used to modulate I(t) and Q(t), respectively. The resultant RF signals are summed, amplified, and transmitted to the receiver via the channel, which could be either a wireless medium or a transmission line.
FIG. 2 shows a block diagram of a typical OFDM receiver 200. As shown in FIG. 2, the received signal is amplified by a low noise amplifier 202, separated into I-path and Q-path, and then demodulated by a quadrature carrier pair (i.e., cos(wt) and −sin(wt)). Low pass filtering (LPF) is performed on both the in-phase and quadrature-phase paths to provide an anti-aliasing function before the I-Q signals are converted into digital samples by a pair of analog to digital converters (ADCs) 208, 214. The serial time domain samples obtained from the ADCs 208, 214 form a sequence of serial complex samples. The serial complex samples are buffered and converted by a SIPO 220 into (N+NGI) parallel samples, labeled 0 to (N+NGI−1) in FIG. 2. The guard interval samples are removed, resulting in N complex samples, again labeled 0 to (N−1). A subsequent N-points Fast Fourier Transform (FFT) 224 generates N frequency domain samples from the N time-domain samples. The frequency domain samples are adjusted in both magnitude and phase by a subsequent frequency-domain equalizer (FEQ) 226 to compensate for the amplitude change and phase shift caused by the channel on a per-tone basis. A per-tone decision on each of the N FEQ outputs is made in the subsequent BPSK/QPSK/QAM demapper 228, resulting in N parallel data paths, where each data path carries a certain bit-load of information. The N parallel data are then converted into serial data by a subsequent PISO 230.
In practice, the OFDM receiver 200 suffers from a phenomenon known as the quadrature mismatch (or I-Q mismatch) problem. As shown in FIG. 3, the quadrature carrier pair generated by a local oscillator 300 within the receiver exhibits a slight phase mismatch. Therefore, instead of generating cos(wt) and −sin(wt) differing perfectly by 90 degrees, the local oscillator 300 generates cos(wt) and −sin(wt+δ). The circuit blocks on the I-path (LPF1 206 and ADC1 208) will also be slightly different from those on the Q-path (LPF2 212 and ADC2 214), as they are all subject to limited component tolerances. These differences and the non 90 degree phase difference both result in I-Q mismatch. To account for the I-Q mismatch, some compensation needs to be performed within the receiver 200.
FIG. 4 shows a typical I-Q mismatch correction circuit 400 according to a first correction scheme of the related art. An amplitude mismatch estimate block 404 is used to estimate the amplitude mismatch between the I and Q paths and to accordingly adjust the gain of one of the paths (e.g., the Q-path in this example) to thereby compensate for the amplitude mismatch. A phase mismatch estimate block 406 is used to estimate the phase mismatch between the I and Q paths and to accordingly adjust the delay on one of the quadrature carrier pair (e.g., again the Q-path in this example) to thereby compensate for the phase mismatch.
FIG. 5 shows another I-Q mismatch correction circuit 500 according to a second correction scheme of the related art. In this circuit 500, instead of physically adjusting the phase of the quadrature carrier pair, both the amplitude mismatch A and the phase mismatch a are estimated. One path (e.g., the Q-path in this example) is scaled by a factor of G2=1/[A×cos(a)] to correct the slight amplitude reduction due to amplitude and phase mismatch, and the cross coupling contribution from this path (i.e., the coupling factor of G2=tan(a) is subtracted from the other path (i.e., the I-path in this example). In doing so, the distortion due to phase mismatch, which is basically I-Q coupling, is removed.
However, the prior art I-Q mismatch correction schemes of FIG. 4 and FIG. 5 have the drawback that they cannot effectively correct I-Q mismatch if the mismatch is frequency dependent. Frequency dependency of the I-Q mismatch problem is particularly pronounced in wide-band applications where the circuit elements need to process a wide range of frequency components. Therefore, an improved method of correcting I-Q mismatch in an OFDM receiver would be desirable.

Orthogonal frequency division multiplexing (OFDM) receiver capable of correcting in-phase and quadrature-phase mismatch and method thereof


A system, mobile device, backend server, and RFID toll module work in cooperation to automatically pay vehicular tolls to a toll agency that operates toll stations along roadways travelled by the user of the mobile device. Upon approaching a toll station the mobile device enables the RFID toll module. The toll reader at the toll station transmits a toll reader signal that is received by the RFID toll module, which responds by transmitting a unique identifier. The unique identifier is associated with the mobile device at a toll account maintained by a toll service backend server. Upon completion of a toll transaction, the RFID toll module indicates the transaction to the mobile device, which forwards toll transaction information to the toll service backend server for payment from the toll account to the toll agency.

Tollways and tollbooths, such as are commonly used on turnpike highways and other toll roads, are used to collect tolls to pay for road maintenance and other costs associated with the toll road. While in the past, and to some extent it is still the case, drivers were forced to stop and pay with currency at each toll plaza, it is increasingly common to use electronic toll collection that allows drivers to simply drive through a toll plaza at ordinary speed. In some automated toll systems, a radio transponder, that can be active or passive, and is located in the vehicle, is read by a radio signal as the vehicle passes under a gantry in a toll plaza. The toll plazas are often operated by a toll agency, which may be a private agency or a government agency. Some examples of toll agencies include SunPass and EZ-Pass. The transponder, typically being mounted in a vehicle, allows for little flexibility when one changes vehicles or is using a rental car. A transponder also lacks the ability to be secured so as to prevent toll fraud or allow tolls in case the vehicle (or transponder) is stolen.
The United States Department of Transportation (USDOT) released an Intelligent Transportation Systems (ITS) Strategic Research Plan for 2010-2014 at the end of 2009. The ITS (its.dot.gov) website discloses the plan as assuming government investment of upwards of $100 million per year for five years. The tolling industry handles its customer base in a somewhat parochial way. In actuality, anyone using public roadways may be seen as a customer. Each tolling facility tracks customers for data such as account information, volume and frequency of trips and where these customers reside. However, the existing agencies do little to incentivize customers to increase user usage of toll agency services. Marketing and rewards programs are rarely used. Therefore, toll agencies focus on reducing costs while increasing reliability of technology solutions (such as ISO 18000 6C reader tag protocol for interoperability), greater efficiencies in logging individuals highway use, and better quality imaging technologies (such as high-definition), to collect delinquent fees from toll evaders, are seeking improved systems.
Current toll options include RFID Tags and Readers, and Transponders used by Toll Companies like EZPass and SunPass, from providers such as Kapsch lack interoperability. The US government issued a mandate for interoperability among various state tolling systems by 2016, accompanied by a plan to distribute and share revenues between the plethora of companies and agencies. A less-desirable default option has been the Toll-by-Plate system, where, rather than having a transponder, the gantry at a toll plaza captures an image of the vehicle's license plate and charges the toll to the owner or registered user associated with the license plate number. However, this system is not sufficiently accurate nor convenient; visibility may often be obscured with obstacles, highway gridlock, and weather, and costs are typically higher than with a more targeted system. Customers unaware of the Toll-by-Plate operation who have not established an account with the agency will typically be charged somewhat punitive charges in addition to the toll.
Accordingly, there is a need for a method and apparatus for an automated tolling system that provide the toll account owner more flexibility and security in tolling, and which preserves the accuracy and reliability of conventional automated tolling systems.

Method and apparatus for providing a toll service and flexible toll device


The invention is directed to a housing for a high-pressure cleaning apparatus for accommodating a high-pressure pump, drive motor and other components of the apparatus coacting therewith. The apparatus is equipped with a cleaning lance which is held on the housing. The housing includes a trough-like lower housing half having a base wall adapted to support the pump and the motor and a trough-like upper housing half for closing off and covering the lower housing. The upper housing half has a top wall defining an outer side facing away from said base wall and a carrying handle is disposed on this outer side to enable an operator to carry the apparatus. The carrying handle is configured as a holder for holding the cleaning lance.

High-pressure cleaning apparatus of the kind referred to above, which have a lower power, are used to an ever increasing extent by individual consumers. These apparatus are intended to be small, compact and configured so that they can be easily manipulated. A suitable holder for the cleaning lance is desirable in order to permit storing the lance during work interruptions and without danger of causing damage. Also, accessory parts such as cleaning brushes, bottles containing cleaning agents or the like should be accommodated so that they can be conveniently grasped by the operator.

Housing for a high-pressure cleaning apparatus


A method of operating a flying capacitor multilevel converter having a direct current link and a plurality of phase legs each having a plurality of flying capacitors includes employing redundant states to balance flying capacitor voltages by charging or discharging flying capacitors. The redundant states are employed by obtaining a load current of the flying capacitor multilevel converter. If a load current value is lower than a threshold value then a capacitor current of a phase terminal capacitor is utilized to determine redundant states else a load current direction is utilized to determine the redundant states.

Embodiments of invention relates to multilevel converters and more specifically to a system and method for voltage balancing in multilevel converters.
Multilevel converters are generally used in high power industrial applications such as variable speed drive (VSD) systems or in energy conversion applications such as a solar (or photovoltaic) power generation systems, wind turbine generators and high voltage direct current (HVDC) transmission systems. One example of a multi-level converter is a flying capacitor (FC) multilevel converter. The flying capacitor multilevel converter includes a number of capacitors referred to as flying capacitors. The flying capacitors are charged to various voltage levels and by changing switching states the flying capacitors and a dc source are connected in different ways and produce various line-to-neutral output voltages.
Voltage balancing of flying capacitors is a challenge when operating the flying capacitor multilevel converter. Flying capacitors voltage unbalance (i.e., unequal voltages across flying capacitors) may overstress the capacitors and switching devices and cause over voltage and under voltage trips during the operation of the converter. Flying capacitors voltage unbalance also causes an increase in output voltage total harmonic distortion (THD) and may cause the control loop to become unstable.
One of the known solutions utilized to balance voltages of flying capacitors uses additional balancing circuitry. However, the balancing circuitry adds cost, losses, volume to the flying capacitor multilevel converter and also needs to be designed carefully.
Therefore, it is desirable to provide a method and a system that will address the foregoing issues.

Voltage balancing system and method for multilevel converters


A photoelectronic device and an avalanche self-quenching process for a photoelectronic device are described. The photoelectronic device comprises a nanoscale semiconductor multiplication region and a nanoscale doped semiconductor quenching structure including a depletion region and an undepletion region. The photoelectronic device can act as a single photon detector or a single carrier multiplier. The avalanche self-quenching process allows electrical field reduction in the multiplication region by movement of the multiplication carriers, thus quenching the avalanche.

The photomultiplier tube (PMT) has dominated the area of single photon counting and single photon detection for many years. While possessing the desired photon counting functionality, i.e., outputting an explicit pulse upon reception of one single photon, a PMT is substantially bulky because of its vacuum tube nature. Besides, wavelength coverage and quantum efficiency of a PMT are both low. These drawbacks, plus low counting rate, high voltage and limited lifetime, make it impossible or very difficult to employ a PMT in many advanced areas, such as high speed photon counting, photon counting imaging, large format and spatially resolved photon and article detection, and space missions.
Geiger mode avalanche photodiodes (GAPDs) have also been employed for single photon counting. However, two major drawbacks, i.e., low speed/low counting rate and a requirement for external quenching, have severely inhibited advanced applications using Geiger mode avalanche photodiodes.
In particular, afterpulsing is an effect that substantially restrains the photon counting rate of a GAPD. Afterpulsing refers to a series of avalanche events triggered by the carriers that were generated in previous avalanche events, captured by the traps located at the vicinity of the avalanche region and then liberated again by these traps. The probability for afterpulsing to occur after detection of a signal photon is correlated to the amount of the traps located in the high field region and also the excess voltage, i.e., the amount of the bias above the breakdown voltage.
The time period needed for the afterpulsing probability to drop to below an acceptable level, which is known as the deadtime of the photon counting detector, normally ranges between microseconds and milliseconds. In order to prevent the afterpulses from being erroneously counted, photon counting should be blocked for a duration, which is named as reset time, after detection of a signal photon.
The upper portion of FIG. 1 shows a sequence 102 of photons incident into a gated GAPD. The lower portion of FIG. 1 shows the photon counting output 104 as a consequence of the photon events counted 106. Since the afterpulsing effect has high probability to occur in a certain time period or deadtime 108 after detection of a photon 110, photon incidency events 112, 114, 116 during the deadtime period are blocked or gated from counting, see reset time 118. As a result, the repeating rate of the photon counting is restricted by the magnitude of the deadtime.
Low avalanche initiation probability (AIP), which is general in GAPDs, leads to low quantum efficiency because the effective quantum efficiency is the product of AIP and the inner quantum efficiency. Avalanche initiation probability refers to the probability of a photoelectron to trigger an avalanche event in a GAPD detector. High avalanche initiation probability needs ideally uniform junction and multiplication region in the GAPD. Any artifacts, which include edge effect, defects and junction curvature, will lead to an "early breakdown" at a specific location and hence significantly reduce the probability for photogenerated carriers at other locations to trigger avalanche events there, leading to low AIP. Moreover, a GAPD pixel in an imaging array will suffer from a more severe AIP problem because its structure has to compromise with the processing technology.
More importantly, a Geiger mode avalanche photodiode (GAPD) requires an external quenching circuit to stop each of the avalanche events occurred inside it for otherwise the device will be burned out by the avalanching current. Because a GAPD pixel will become inactive after capture of one photon and the operation to reset the inactive pixels through the external quenching circuits is slow, a GAPD imager cannot recognize a scene unless the photon flux is very low, Leading to a very low dynamic range.
Passive and active quenching are the two quenching techniques currently available. Their typical circuits are schematically illustrated in FIG. 2 and FIG. 3. As discussed below, passive quenching is intrinsically slow because of the RC effect originated from the required high value of the quenching resistor. On the other hand, in view of chip area and power consumption requirements, active quenching does not suit array applications.
In particular, FIG. 2 shows a traditional Geiger mode Avalanche photodiode (GAPD) 202 in series with a passive quenching resistor 204. Once an avalanche effect occurs in the GAPD device 202, the high value of the resistor 204 will lead to a drop of the voltage across the GAPD 202 to below its breakdown voltage, hence quenching the avalanche process. A possible value for resistor 204 is 100 kΩ. Such high value of the resistor 204 results in a slow quenching process and even slower reset process, as also illustrated by the output waveform 206.
FIG. 3 shows a GAPD 302 with an active quenching circuit 304. While high speed can be achieved with the help of the quenching circuit 304, additional power consumption and space (or chip area, in the case of integrated circuits) will be required to implement this measure. For this reason, active quenching does not suit a GAPD imaging array. To exclude an erroneous counting of pulses resulting from the afterpulsing effect, a gating function 306 is incorporated in the quenching circuit 304 to prevent photon counting for a certain period after a real photon count. This, however, means that the afterpulsing effect will degrade the speed performance of a GAPD, even in the presence of a high speed quenching circuit.
There have been efforts to construct a "solid-state photomultiplier" (Christopher Stapels et al. "Solid-State Photomultiplier in CMOS Technology for Gamma-Ray Detection and Imaging Applications" Nuclear Science Symposium Conference Record, 2005 IEEE Volume 5, 23-29 Oct. 2005 Page(s): 2775-2779). However, such photomultiplier is an integrated detector array with one traditional GAPD and one passive quenching resistor at each pixel.
So-called "reach-through" structures are also known in the art. FIG. 4 shows the structure (upper portion of the figure) and the electric field bias profiles at different levels (lower portion of the figure) of such reach-through structure. This structure has been widely used in various avalanche photodiodes built on different semiconductor materials.
By inserting a layer 404 of p type reach-through structure beneath a multiplication region 406 in a structure also comprising a cathode 408, an anode 410, and an absorption region 412, high field will be restricted in the multiplication region 406 sandwiched between the cathode 408 and the reach-through structure 404. This will eliminate the probability for an avalanche event to occur outside the multiplication region 406. As the bias increases, the reach-through structure 404 will be fully depleted first and then the depletion region will penetrate into the absorption region 412, followed by breakdown occurring in the multiplication region 406.
The term "nanoscale" is used throughout the present disclosure to describe the lateral structural feature of all the component parts of the device according to the present disclosure that are contained in a pillar structure. In order to reflect the specific dimensional feature of the detector, the implication of the term "nanoscale" through the present disclosure is a little bit different from its usual meaning. In particular, throughout the present disclosure the term "nanoscale" will refer to a dimension ranging from 1-2,000 nm, and a nano-pillar will mean a pillar structure with a "nanoscale" diameter.

Single photon detection with self-quenching multiplication


A low-noise amplifier includes a first amplification device. The first amplification device includes a control terminal, a first terminal, and a second terminal. The low-noise amplifier also includes a feedback circuit in communication with the control terminal and the first terminal. The feedback circuit compares a voltage, corresponding to an output current associated with the first terminal, with a predetermined reference voltage to generate a bias signal applied to the control terminal for biasing the low-noise amplifier.

1. Field of the Invention
The present invention relates to integrated circuits. More particularly, the present invention relates to an active bias circuit for low-noise amplifiers.
2. Background Information
Typically, in low-noise amplifiers (LNAs) and the like, it is desirable to reduce the contribution of noise from any component as much as possible. In bipolar circuitry, for example, a bias current is applied to the base of the transistor that comprises the LNA. However, due to process variations, temperature, and the like, the β of the transistor can vary by a factor of two, three, four or more. As a result of such varying transistor characteristics, the level of the bias current required to be applied to the transistor will change, resulting in a varying control of the gain of the LNA. Thus, under different conditions and varying transistor characteristics, the gain of the LNA can vary, which in most applications is unacceptable.
To address this problem, passive circuitry can be used to control the bias current applied to the transistor. For example, a diode device can be connected to the base electrode of the transistor. Such a diode device has an impedance proportional to I/Gm. For a 50Ω incoming signal, such an impedance can be too low, which can result in significant signal attenuation. In addition, any noise generated by the diode device and current sources connected to it will be transferred to and affect the rest of the LNA circuit.
Consequently, a biasing scheme is needed that is independent of process variations, temperature, variations in the β of the transistor, and other like transistor characteristics.

Active bias circuit for low-noise amplifiers


A method for securely connecting a software defined radio (SDR) to a server through a network is presented. A request to download a radio configuration (R-CFG) file is sent from the SDR device to the server. A determination is made that the R-CFG file is configured to control a plurality of radio frequency parameters for the SDR device solely within levels permitted by a regulatory agency. The R-CFG is then downloaded to the SDR device.

A significant demand exists for mobile devices capable of communicating in any wireless standard such as code division multiple access (CDMA) or global system for mobile communications (GSM). A software defined radio (SDR) device exemplifies such a device.
In a SDR device, functions that were formerly carried out solely in hardware, such as the generation of the transmitted radio signal and the tuning of the received radio signal, are controlled by software. Because these functions are controlled by software, the radio is programmable, allowing it to transmit and to receive over a wide range of frequencies and to emulate virtually any desired transmission format. Accordingly, instead of discarding the SDR device when a technological advance occurs, the SDR device merely requires downloading a software upgrade referred to as a radio configuration (R-CFG) file to accommodate this change.
There are several disadvantages associated with the present method for dynamically loading a R-CFG onto a SDR device. First, an inefficient amount of messaging occurs between the SDR device and a server of a SDR device manufacturer during the process of loading the R-CFG onto the SDR device. Second, a lack of security exists to prevent downloading malicious code onto the SDR device. Third, the present method lacks an automatic method of ensuring that a R-CFG does not exceed a permitted operating parameter (e.g., the frequency, the modulation type, the output power, and the maximum field strength) associated with the SDR device. It is therefore desirable to have a system or a method that overcomes these disadvantages.

System for inhibiting installing a radio configuration file onto a software defined radio device unless the file is compatible with the device

Matsushita Electric Industrial Co., Ltd.


A guiding system for a sliding door, especially a motor vehicle, comprising a sliding rail (5) with an upper cover (6) and a lower edge (7) arranged opposite the upper cover (6), and a roller element (101) which is guided in the sliding rail (5) and comprises a roller element housing (102) is presented. Three rollers (103, 104) are rotatably fixed to the roller element housing (102), two rollers (103) extending along the upper cover (6) of the sliding rail (5) and the third roller (104) extending along the lower edge (7). The invention creates one such guiding system in such a way that there is no play, it operates quietly, and has a taut system characteristic. To this end, a spring element (109) is fixed to the roller element housing (102), said spring element pressing on of the first two roller (103) and the third roller (104) against the sliding rail (5).

Guiding systems of the as-cited type for sliding doors for vehicles and motor vehicles are known from the prior art. Guiding systems of this type have the disadvantage that the rolling elements in the guide rails have play and are thus not guided accurately, the operation rather causing undesired noise and not providing a taut system characteristic.
Guiding systems are known in which the runner rails are arranged either on the vehicle body or in the door and the rolling elements are correspondingly arranged in an opposite manner on the door or the vehicle body, for example on the door pillar.
DE 100 45 589 A 1 describes a guiding system for a sliding door in which a runner device arranged on the inside of the sliding door is guided in a guide rail fastened to the outer wall of the vehicle body. In this case, a horizontally mounted support roller of the runner device rests on the flat lower termination of the guide rail. Two vertically mounted guide rollers of the runner device are supported on the guide rail guide part which runs parallel to the rear wall, the guide part and rear wall being connected by means of a downwardly open V-shaped covering part. The sliding door system has a safety device, which functions by means of predetermined fracturing points, to prevent deformation as a result of accidents.
EP 1 153 198 A 1 describes a guiding system for a sliding door of a motor vehicle which comprises an upper runner rail and a lower runner rail. A rolling element designed as a carriage is guided in the lower runner rail, the rolling element having a plurality of upper and lower rollers, which respectively run along against an upper cover and a lower termination of the runner rail. In particular, two carriages each have two rollers with their axes horizontal and two rollers with their axes perpendicular to the current direction of movement of the carriage. Correspondingly, the upper runner rail has an upper carriage, to which upper and lower rollers are fastened and these respectively run along against the upper and lower duct section. The upper runner rail and the lower runner rail each have a C-shaped section, the upper runner rail however being arranged at 90° in relation to the lower runner rail. It is disadvantageous that the arrangement is susceptible to noisy operation, the rollers not being guided in an entirely accurate and taut manner. It is also disadvantageous that the rollers which are subject to wear over time lose contact with the runner rails and must then be adjusted by hand, which is complex, in order be able to lessen the noise of operation.
DE 6 806 861 U describes a guiding system for a sliding door of a motor vehicle which comprises an upperrunner rail and a lower runner rail. A first roller and a second roller are guided in the upper runner rail. The axes of the two rollers are connected permanently to a door but not to one another, so that the two rollers are not part of a rolling element, for example of a carriage. The first roller lies, in a closed position, in a first depression and the second roller in a second depression. If the door is moved, the first roller should in particular be prevented from running into the second depression which is assigned to the second roll, for which purpose a cylindrical axle bush is provided on the first roller and said axle bush interacts with an edge at the position of the second depression such that the axle bush is guided by the edge and the first roller does not run into the second depression. The arrangement in particular does not ensure that all of the rollers are in contact with an upper cover (upper rail) or a lower termination (lower rail) at all times. It is disadvantageous that the rollers have play which cannot be suppressed, so that operation of the sliding door is noisy.
DE 848 763 describes a guiding system for a sliding door of a motor vehicle, a first roller designed as a first guide roller and a second roller designed as a second guide roller being guided in a runner rail, which rollers are mounted on the two short arms of a T-shaped support lever. The long arm of the T-shaped support lever is fastened to the door by means of a bearing block. The two guide rollers are rotatable about a rotating pin. The lever arm of the support lever is loaded by a spring element in the form of a preloaded compression spring, the counterbearing of which is arranged in the bearing block. The compression spring loads the lever arm, and thus the two rollers which can be pivoted about the rotating pin, in such a way that the two rollers are constantly in contact with the limbs of the runner rails of U-shaped section. It is disadvantageous that the compression spring is fixedly connected to the door by means of the bearing block, and hence in particular cannot move with the two rollers along the runner rail. It is also disadvantageous that the overall construction is complex and is visually difficult to conceal. The construction relates in particular to the clamping of guide rollers, hence of rollers whose rotational axis is vertical, while the subject matter of the application is support rollers whose rotational axis is horizontal and in this case perpendicular to the instantaneous direction of movement of the respective rollers.
DE 196 34 369 C1 describes a guiding system for a sliding door of a motor vehicle which comprises a runner rail in which two rollers are guided, the rolling axes of which are horizontal and perpendicular to the instantaneous direction of movement. The two rollers are fastened to a rolling element designed as a carriage. The two rollers both run against a lower termination of the guide rail. A closing roller with a perpendicular rolling axis is also attached to the carriage, which closing roller engages in a closing groove. It is disadvantageous that the carriage in the runner rail has play so that it is not guided in a secure and taut manner.
DE 835 718 B describes a mounting for rolling elements, in particular of spheres and cylindrical rollers, which are guided along a runner rail and are held in a further rail, the bearing rail. The rolling elements designed as cylindrical rollers are supported by means of a perforated tape and loaded by means of springs. It is disadvantageous that the rolling elements have play which cannot be eliminated and which directly prevents a taut guidance of the sliding door. It is also disadvantageous that the arrangement is of very complex design.


A driver for a DC-to-DC converter that may utilize a flyback or buck-boost converter circuit. The driver includes a driver circuit and an interface circuit. The interface circuit has a sensor sensing an input voltage from a DC supply and generating a sensor signal to a driver selector. The driver selector compares the sensor signal to a comparison voltage to determine the type of converter circuit and then transmits a selector signal to a driver circuit where it is used to control one or more of the components of the driver circuit, such as the logic circuit which is used for driving the converter to regulate the converter output. The sensor includes a sense resistor along with a current-sense amplifier, which is adapted for connection to a high side or a low side of a power supply while still producing a substantially equivalent output voltage or sensor signal.

1. Field of the Invention
The present invention relates generally to voltage converters, and more particularly, to a driver with a smart or adaptive interface that allows the driver to be used in varied direct current (DC) to direct-current (DC) converters utilizing differing types or configurations of converter circuits, such as buck-boost and flyback DC-to-DC converter circuits, without modification of the driver.
2. Relevant Background
Direct-current (DC) to direct-current (DC) converters are well known in the field of electronics. DC-to-DC converters are typically employed to convert from one DC voltage level to another DC voltage level. They are used in a variety of environments. For example, DC-to-DC converters are used to provide a supply voltage to microprocessors and other logic devices and are also used in many electronic systems to provide supply voltage, such as in a disk drive where the converter supplies a desired voltage to a voice coil motor and spindle motors. The voltage source may be a battery, such as in a notebook or handheld computer or electronic device, or some other power source that provides a DC voltage, such as 1 to 36 V. The DC-to-DC converter functions to convert this supply or input voltage to one or more regulated output DC voltages required by the load, i.e., the microprocessor, the motor driver, and the like. For example, many logic devices on integrated circuits (ICs) work on 1.2, 3.6, and 5 V supplies from a converter while the power source supplies 12 V or other supply voltage. The DC-to-DC converter may be provided as part of an integrated circuit (IC) such as on an IC with a microprocessor or on a separate IC or provided as part of a standard circuit in other applications.
There are a variety of DC-to-DC converters designs, such as pulse-width modulated (PWM) converters and pulse-frequency modulated (PFM) converters, but generally each of the DC-to-DC converters includes a converter circuit and a driver. The converter circuit converts the input or supply voltage into a desired output or load voltage. The driver functions to provide control signals to the converter circuit to regulate the output or load voltage produced by the converter circuit. There are presently numerous converter circuits utilized in DC-to-DC converters. Two common converter circuits are labeled flyback converters and buck-boost converters based on their functioning and the arrangement of their circuit components. Other converters circuits include boost converters and buck converters.
To drive these converters, a driver is designed that includes a variety of circuitry and components. For example, a common implementation of a driver includes blocks or devices to generate a reference voltage for use in regulating the output of the converter circuit, a feedback to sample the converter circuit output, a circuit for generating an error signal based on the reference voltage and the feedback signal, a modulator for modulating the output based on the error signal (such as a pulse-width modulator in a PWM converter), additional control components (e.g., a component for limiting the maximum duty cycle of the modulator signal, a current limitation device for limiting the current of a transistor in the converter circuit, and a voltage lock out circuit for switching on and off circuits in the driver based on the level of the input power), and a logic circuit for combining the signals of the other components and providing a drive signal to the converter circuit to regulate the converter circuits output.
To design or create a DC-to-DC converter, a driver is paired with one of the converter circuit types. In some cases, the driver is manufactured separately from the converter circuit, e.g., in two separate ICs. However, a driver is typically configured to drive a single type of converter circuit and cannot be used in multiple converter applications. For example, a driver may be designed and manufactured for use or pairing with a buck-boost converter circuit that includes a P-channel switching transistor. In other words, the driver is configured to provide a drive or output signal to drive this particular type of transistor. Without modification, this specially configured driver cannot be used with a flyback converter circuit, which includes an N-channel switching transistor. Presently, this problem is addressed by designing and manufacturing a unique driver for each of the converter circuits and by combining these differing drivers with the differing converter circuits to manufacture DC-to-DC converters. Redesigning the drivers for different types of converter circuits results in undesirable and often, unacceptable increased engineering and manufacturing costs associated with the produced DC-to-DC converters.
Hence, there remains a need for a driver for DC-to-DC converters that is compatible with more than one converter circuit type and is thus interchangeable. Preferably, such a driver would be able to interface with different converter circuits with minimal or no modification, would be relatively easy to produce with low associated costs with known existing manufacturing capabilities, and would be readily accepted by the electronics industry as providing effective control and/or regulation of the output of the converter circuit.

Driver for DC-to-DC converter with controller interface