The frequency control and phase control of a voltage-controlled oscillator (50) of a phase-locked loop (100) comprise two current paths. The frequency control system comprises a filter (75) that converts pulse output current (i.sub.1) of a charge pump (70) generated by phase error signals (X.sub.1, X.sub.2) to a DC voltage, and a resistor (R.sub.1 or R.sub.2) that converts that voltage to DC current (i.sub.3), and the phase control system comprises a charge pump (80) that generates a pulse output current (i.sub.2) using the phase error signals (X.sub.1, X.sub.2). The frequency and phase of the oscillator output (V.sub.OUT) of the voltage-controlled oscillator (50) is controlled by a composite current i.sub.4, which is the sum of the DC current (i.sub.3) and the output current i.sub.2. Since it is possible to make the natural angular frequency proportional to the data transfer rate while the damping factor remains unchanged, by changing the value of the currents (i.sub.3, i.sub.2) through the switching of switches (SW.sub.1, SW.sub.2) when the data transfer rate of the input signal (S.sub.IN) changes, a phase-locking characteristic can be realized that accommodates a wide range of data transfer rates.

The invention generally relates to phase-locked loops that generate a clock synchronized in phase with an input signal and more particularly to improving phase-locked loops applicable to zone bit recording in hard disk systems, etc.
As shown in FIG. 4, prior art configurations widely used for phase-locked loops in data separators and frequency multiplier circuits for magnetic disk devices, etc., comprise, a phase comparator 10 which compares the phases of an input signal S.sub.IN, a reference signal, and an oscillator output V.sub.OUT (at oscillation frequency f.sub.OSC) of a voltage-controlled oscillator 40, and outputs first and second phase difference detection signals X.sub.1 and X.sub.2. A charge pump 20 supplies a charge/discharge current i (pulse output current) to a loop filter 30 capacitor C.sub.F which is based on the first and second phase difference detection signals X.sub.1 and X.sub.2. Loop filter 30 is a low pass filter (LPF) which is configured as a series circuit including resistor R.sub.F and capacitor C.sub.F, and voltage-controlled oscillator (VCO) 40 which generates oscillator output V.sub.OUT at oscillation frequency f.sub.OSC, which corresponds to a value for analog filter output voltage V.sub.F, which is used as a control input.
Voltage-controlled oscillator 40 generally comprises a voltage-current conversion circuit, which converts the control input voltage into a current, and a current-frequency conversion circuit which changes the frequency f.sub.OSC of oscillator output V.sub.OUT, according to the resulting output current. Oscillation frequency f.sub.OSC of voltage-controlled oscillator 40 may be input into phase comparator 10 using a prescribed divider. Phase comparator 10 is a digital phase comparator; e.g., configured from a pair of D-type flip-flops and a logic gate. Charge pump 20, as shown in FIG. 5, is a series circuit configured from a switching transistor 22 (p-type MOSFET) used for source current switching, which turns ON when first phase difference detection signal X.sub.1 is at a low level, a constant current source 24 used to generate source current; a switching transistor 26 (n-type MOSFET) used for sink current switching, which turns ON when second phase difference detection signal X.sub.2 is at a high level, and a constant current source 28 used to generate sink current.
When a phase difference occurs in oscillator output V.sub.OUT with respect to input signal S.sub.IN in a phase-locked loop having the above configuration, phase comparator 10 generates phase difference detection signals X.sub.1, X.sub.2. Charge pump 20 outputs source or sink current i using signals X.sub.1, X.sub.2, as shown in FIG. 6. Therefore, a voltage drop is generated across resistor R.sub.F of filter 30 and capacitor C.sub.F is charged and discharged by this pulse current. Since oscillation frequency f.sub.OSC of voltage-controlled oscillator 40 is varied by the value of the filter output voltage V.sub.F, the phase difference between oscillator output V.sub.OUT and input signal S.sub.IN becomes zero as time progresses.
During a time in which signals X.sub.1, X.sub.2 of each period are not generated, an integrated load is stored in capacitor C.sub.F, and, therefore, the output of voltage-controlled oscillator 40 is controlled by that charging voltage. Therefore, the charging voltage of capacitor C.sub.F for current i functions as a frequency control signal for the pull-in operation that matches oscillation frequency f.sub.OSC to the frequency of input signal S.sub.IN. The voltage drop in resistor R.sub.F for current i functions as a phase control signal for the lock-in operation since it controls the output phase of voltage-controlled oscillator 40, when error signals X.sub.1, X.sub.2 are generated.
Since this kind of phase-locked loop performs phase locking with respect to a specific input signal S.sub.IN which fluctuates within a narrow frequency range, the value of the electrical element of each circuit is optimized. These include, for example, the value of output current i of charge pump 20, the time constant of loop filter 30, and the conversion factor for the output frequency of the voltage-controlled oscillator 40 with respect to the input voltage. Therefore, in zone bit recording in a hard disk system, input signal S.sub.IN is generated, for example, at data transfer rates of four zones (f.sub.1 =8 MHz, f.sub.2 =10 MHz, f.sub.3 =12 MHz, f.sub.4 =14 MHz) in which the data transfer rate is switched, but since the frequency component for jitter also changes, it is necessary to perform an adjustment that optimizes the values of the above circuit elements at the points of change. More specifically, it is necessary to provide a plurality of loop filters with differing time constants, and to switch and connect to the optimum loop filter in synchronization with the switching of the frequency of the input signal.
The two equations below are important equations for describing the basic characteristics (phase difference characteristics) of a phase-locked loop that uses loop filter 30 as shown in FIG. 5. ##EQU1##
Here, w.sub.n is the natural angular frequency, z is the damping factor, K.sub.v is voltage frequency conversion factor of voltage-controlled oscillator 40, K.sub.c is the phase comparator conversion factor that matches phase comparator 10 and charge pump 20, C is the electrostatic capacitance of capacitor C.sub.F of loop filter 30, and R is the resistance value of resistor R.sub.F of loop filter 30. Natural angular frequency w.sub.n must change in proportion to the frequency for quick lock-in when the frequency (data transfer rate) of input signal S.sub.IN is high, but it is generally necessary to make damping factor z a constant value (e.g., 2.sup.-1/2 .apprxeq.0.7). This is important from the standpoint of the phase step response and peak shift margin characteristics of the phase-locked loop. Because of its circuit configuration, voltage-controlled oscillator 40 has fixed voltage frequency conversion factor K.sub.v, and, therefore, cannot be easily changed from outside the circuit. Therefore, when the data transfer rate is changed, w.sub.n can be made proportional to the data transfer rate while z remains constant by making K.sub.c proportional to the data transfer rate, making C inversely proportional to the data transfer rate and making R constant. Here, K.sub.c is generally displayed in radians and is given by i/2p. Therefore, if output current i is made proportional to the data transfer rate by switching the internal circuit, factor K.sub.c becomes proportional to the data transfer rate, and, therefore, current sources 24 and 28 must be configured as variable current sources.
However, the phase-locked loop described above which uses a filter comprising a resistor and a capacitor presents the following problems.
(1) When the data transfer rate is fast, output current i of charge pump 10 must be made large, the value of capacitor C.sub.F of filter 30 must be made small. By comparison, when the data transfer rate is slow, the voltage drop of resistor R.sub.F and the charge voltage of capacitor C.sub.F become extremely large when output current i is generated. For this reason, the dynamic range is narrow because output voltage V.sub.F of filter 30 is readily clipped by the power source voltage. Therefore, the higher the data transfer rate, the narrower the pull-in range.
(2) When the above phase-locked loop is configured as an integrated circuit (IC) chip, the following problems are encountered. That is, plural loop filters configured as series circuits of C and R must be attached externally to the IC chip, and selection of an optimum loop filter synchronized with the switching of the data transfer rate. But when output current i is supplied to external loop filter 30 from charge pump 20 built into the IC chip, the value of output current i must be large.
This is because a requisite parasitic capacitance is generated in the wiring path from the charge pump inside the IC to the external loop filter (output cell, bonding wire, lead frame, etc.) or in the opposite wiring path from the loop filter to the voltage-controlled oscillator 40 inside the IC. Therefore, charge pump 20 must generate a somewhat large output current in consideration of the amount of charge consumed by the parasitic capacitance. This output current must be made larger as its frequency range increases more than the low frequency range. This is because as the data transfer rate changes to a higher frequency range, the pulse duration of phase difference detection signals X.sub.1, X.sub.2 becomes shorter and the drive time of charge pump 20 becomes smaller; e.g., in the case of a 50 MHz input signal S.sub.IN, the drive time drops to less than 20 ns. Therefore, it is necessary to set the output current to a value with a larger margin in anticipation of the charge consumed by the parasitic capacitance. In order for the charge pump to generate this kind of large output current, it is necessary to use large MOS transistors to form current sources 24, 28 and to use large (gate width) switching transistors 22, 26 so that their ON resistance is small and current capacity is large.
This increased transistor size naturally promotes increased parasitic capacitance between the gate and the drain, and the so-called feed through effect of the gate signal extending to the output terminal becomes larger, resulting in waveform distortion due to disturbance of the rectangular waveform of the loop filter drive current. Also, since there is an increase in the gate capacitance accompanying the increased gate area, which is a natural result of the increased transistor size, a gate signal with a pulse duration of several nanoseconds is consumed by the gate capacitance, thus making the ON/OFF operation of the transistor difficult when a gate signal is impressed. When a switching speed of several nanoseconds becomes impossible, the resolution of phase locking becomes irregular. In other words, phase locking is poor within the high frequency range. Further, though a pulse type output current i is supplied to the external loop filter, the pulse type output current itself contains a considerable high frequency component, and, therefore, as the pulse duration becomes shorter, a wiring inductance component manifests itself, which greatly disturbs the output current waveform and tends to destabilize the input voltage of voltage-controlled oscillator 40, resulting in poor phase locking stability.
The invention solves the above problems. First, it offers a phase-locked loop capable of making the phase difference between the input signal and the output signal zero even when the frequency of the input signal, which is the reference signal, changes discretely or continuously. Secondly, it offers a phase-locked loop with a wide pull-in range even in phase-locking operations for input signals of any frequency. Thirdly, it offers a phase-locked loop with superior phase locking resolution, and phase locking in high frequency ranges while also having good phase-locking stability.

Phase-locked loop having frequency and phase control current pumps


A tool for clamping against the interior of a chimney flue having a scissors jack mechanism for adjustably clamping into various size chimneys. A seal plate for sliding over the shaft of the clamping device and for tightly sealing against the interior chimney flue walls. A cleaning brush mechanism affixed to the end of a tubular member, sized to slide over the clamping shaft for cleaning the interior of a chimney.

The present invention relates to a tool for cleaning and repairing chimneys; more specifically, the invention relates to a tool which provides access and a grasping mechanism for the inside of a chimney. The tool has utility and advantage for both cleaning the chimney interior and for replacing defective sections of chimney construction.
In the field of chimney cleaning it is typical to use a brush-like head attached to the end of a long handle; frequently the handle is assemblable in sections to permit access to the interior of a chimney from the exterior roof of a building. The chimney is cleaned by moving the brush-like head up and down inside the chimney, thereby permitting accumulations of dirt and other matter which cling to the chimney interior to fall through the bottom of the chimney. Naturally, precautions must be taken to provide a collection receptacle beneath the bottom of the chimney opening to collect the falling dirt and particulate matter to facilitate the clean-up process. Frequently, in a chimney above a fireplace opening it is necessary to seal the entire fireplace opening during the cleaning process in order to prevent dirt and dust from entering the room of the fireplace opening. Examples of chimney cleaning devices can be found with reference to U.S. Pat. Nos. 4,538,317, issued Sep. 3, 1985; 1,770,436, issued Jul. 30, 1930; 1,464,249, issued Aug. 7, 1923; and 1,066,688, issued Jul. 8, 1913.
In the field of chimney construction and repair, it is typical that chimneys are constructed with interior flues having sections stacked one atop another. Such flues may be made from cylindrical metallic sections or from rectangular masonry sections. In all cases, the lowermost section is supported above the firebox and additional sections are stacked vertically to the top of the chimney. If any particular section becomes corroded, cracked or damaged, the section may be replaced by first removing all sections above it, access being had from the top of the chimney, and then removing and replacing the defective section. The previously removed sections may then be replaced in their relative stacked positions to complete the repair job.
In both the foregoing circumstances it is desirable to utilize a tool which is capable of insertion downwardly through the top end opening of the chimney to permit convenient access into the chimney interior. It is necessary that the tool be capable of being lowered downwardly through the entire length of the chimney and that it be conveniently removable from the top of the chimney opening.


Methods and apparatus are provided for detecting data inconsistencies. Methods are disclosed for determining whether a set of conditional functional dependencies are consistent; determining a minimal cover of a set of conditional functional dependencies and detecting a violation of one or more conditional functional dependencies in a set of conditional functional dependencies. The conditional functional dependencies comprise one or more constraints that data in a database must satisfy including at least one pattern with data values.

Recent statistics reveals that "dirty" data costs businesses in the United States billions of dollars annually. It is also estimated that data cleaning, a labor-intensive and complex process, accounts fox 30%-80% of the development time in a typical data warehouse project. These statistics highlight the need for data-cleaning tools to automatically detect and effectively remove inconsistencies and errors in the data.
One of the most important questions in connection with data cleaning is how to model the consistency of the data, i.e., how to specify and determine whether the data is clean. This calls for appropriate application-specific integrity constraints to model the fundamental semantics of the data Commercially-available ETL (extraction, transformation, loading) tools typically have little built-in data cleaning capability, and a significant portion of the cleaning work has to still be done manually or by low-level programs that are difficult to write and maintain. A bulk of prior research has focused on the merge-purge problem for the elimination of approximate duplicates, or on detecting domain discrepancies and structural conflicts.
There has also been recent work on constraint repair that specifies the consistency of data in terms of constraints, and detects inconsistencies in the data as violations of the constraints. However, previous work on constraint repair is mostly based on traditional dependencies (e.g., functional and full dependencies), that were developed mainly for schema design, but are often insufficient to capture the semantics of the data.
A need exists for improved methods and apparatus for detecting data inconsistencies.

Methods and apparatus for capturing and detecting inconsistencies in relational data using conditional functional dependencies


A data communication method comprises the steps of transmitting, in a batch, measurement data necessary for measurement of electrical characteristics of a plurality of objects to be tested from a probing apparatus to a tester, prior to conducting a test of the electrical characteristics of the objects, the probing apparatus being connected to the tester and measuring the electrical characteristics of the objects, and transmitting, in a batch, measurement result data on two or more of the objects from the tester to the probing apparatus after the electrical characteristics of the two or more of the objects have been measured.

This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-319545, filed Nov. 10, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a data communication method and a data communication system. More particularly, this invention relates to a data communication method and a data communication system for data communication between a probing apparatus and a tester.
In a semiconductor device fabrication process, a great number of IC chips T are formed on a surface of a wafer W, as shown in FIG. 3. On the basis of results of tests of electrical characteristics of chips T on the wafer W, the chips T are screened and classified into good ones and defective ones. The tests are carried out using a probing apparatus, for example, as shown in FIG. 4. In FIG. 4, a tester 20 is connected to a probing apparatus 10 over a communication line 30. In the probing apparatus 10, chips T on a wafer W are electrically connected to the tester 20, and the tester 20 tests various electrical characteristics of the chips T.
The probing apparatus 10, as shown in FIG. 4, comprises a loading chamber 11 for feeding and prealigning a wafer W, and a probing chamber 12 for receiving the wafer W from the loading chamber 11 and testing electrical characteristics thereof. Within the probing chamber 12, there are provided a mainchuck 13 for supporting the wafer W, an aligning mechanism 14 for aligning the wafer W at a predetermined position, and a probe card 15. The probe card 15 has a plurality of probes 15A which are to be put in electrical contact with test electrodes of the chips T on the wafer W. The mainchuck 13 supporting the aligned wafer W is index-fed within the probing chamber 12. The electrical characteristics of each chip T are measured in every index-feed operation in each chip or in units of several chips. A test head 21 is disposed on a head plate 16 of the probing chamber 12. The test head 21 is electrically connected to the probe card 15.
Data communication is performed between the probing apparatus 10 (more specifically the test head 21) and the tester 20. For example, the probing apparatus 10 transmits to the tester 20 a measurement data signal indicative of the kind of a test for the wafer W placed on the mainchuck 13 (e.g. coordinates of positions of chips T on wafer W, the order of measurement, channel information on the number of chips to be tested at a time, the number of defective chips within a hatched region in FIG. 3 (i.e. the number of chips requiring no test) (hereinafter referred to as xe2x80x9con-wafer informationxe2x80x9d) as well as a measurement start signal. After measuring the electrical characteristics of each chip T, the tester 20 transmits measurement result data along with a measurement end signal to the probing apparatus 10.
As is shown in FIG. 4, the test head 21 and tester 20 are connected via GP-IB interface terminals and a cable (hereinafter referred to as xe2x80x9cGP-IB linexe2x80x9d) 30 which are adopted in ordinary measuring devices. The aforementioned data such as on-wafer information, channel information and measurement result information is transmitted between the test head 21 and tester 20 over the GP-IB line 30. In some cases, the probing apparatus 10 and tester 20 are connected via, e.g. a TTL interface and a cable (hereinafter referred to as xe2x80x9cTTL linexe2x80x9d).
With an increase in diameter of the wafer W and in integration density of chips T, the through-put has decreased more and more. Under the circumstances, it is very important to increase the speed of tests. The GP-IB line, which is currently used for general purposes, is advantageous in that a great deal of data can be transmitted at a time. However, it requires much time for communication, and high-speed communication cannot be achieved. Thus, the increase in through-put is limited. Specifically, each time the mainchuck supporting the wafer is shifted in an index-feeding manner, a measurement signal and a measurement start signal are transmitted between the probing apparatus 10 and tester 20. In addition, after the measurement is finished, measurement result data and a measurement end signal are transmitted between the probing apparatus 10 and tester 20. Where the transmission is effected over the GP-IB line 30, a time of 0.2 to 0.3 second, for instance, is needed to transmit the measurement signal and measurement result data between the tester 20 and probing apparatus 10 each time the wafer mainchuck is shifted in the indexfeeding manner. Because of this time, the through-put cannot be enhanced. On the other hand, the TTL line is suitable for high-speed data communication, but the amount of data to be transmitted is small (e.g. the data amount corresponding to 8 chips). Thus, the data for more than 8 chips cannot be transmitted.
The present invention aims at solving the above problems and transmitting a great deal of data, such as all measurement data and measurement result data relating to an object to be tested, in a batch at high speed.
The object of the present invention is to provide a data communication method and a data communication system capable of enhancing a through-put.
According to an aspect of the present invention, there is provided a data communication method for data communication in a probing apparatus connected to a tester and measuring electrical characteristics of a plurality of objects to be tested, comprising the steps of:
transmitting, in a batch, measurement data necessary for measurement of the electrical characteristics of the objects from the probing apparatus to the tester, prior to conducting a test of the electrical characteristics of the objects; and
transmitting, in a batch, measurement result data on two or more of the objects from the tester to the probing apparatus after the electrical characteristics of the two or more of the objects have been measured.
In this data communication method, it is preferable that the measurement data and the measurement result data are transmitted over an Ethernet.
In these data communication method, it is preferable that before and after the electrical characteristics of the two or more of the objects are measured, a predetermined signal is transmitted between the tester and the probing apparatus over at least one of a TTL interface line and a GP-IB line.
In these data communication method, it is preferable that a measurement start signal is transmitted from the probing apparatus to the tester over the TTL interface line before the electrical characteristics of the two or more of the objects are measured, and a measurement end signal is transmitted from the tester to the probing apparatus over the TTL interface line after the electrical characteristics of the two or more of the objects are measured.
According to another aspect of the invention, there is provided a data communication system between a probing apparatus and a tester, the data communication system comprising a network for transmitting, in a batch, measurement data necessary for measurement of electrical characteristics of a plurality of objects to be tested from the probing apparatus to the tester, and for transmitting, in a batch, measurement result data on the plurality of the objects from the tester to the probing apparatus.
In this data communication system, it is preferable that the network is an Ethernet.
It is preferable that these data communication system further comprise at least one of a TTL interface line and a GP-IB line over which a predetermined signal is transmitted between the tester and the probing apparatus before and after the electrical characteristics of the two or more of the objects are measured.
It is preferable that these data communication system further comprise a TTL interface line over which a measurement start signal is transmitted from the probing apparatus to the tester before the electrical characteristics of the two or more of the plurality of the objects are measured, and over which a measurement end signal is transmitted from the tester to the probing apparatus after the electrical characteristics of the two or more of the objects are measured.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.

Data communication method and data communication system


A liquid leakage sensor, paper for detecting liquid leakage, and holder for detecting liquid leakage stably and reliably without being affected by bubbles when a large volume of liquid leaks at once. A liquid leakage sensor also has a tilt detection capability that does not use a test paper and can quickly and reliably detect liquid leakage even before the liquid contacts the case bottom.

1. Field of the Invention
The present invention relates to an improvement of a liquid leakage sensor for reliably detecting leakage of water, an acid solution, an alkaline solution, or other liquid that is electrically conductive, or leakage of alcohol, thinner, benzene, or other organic liquid that has dielectric properties, without being affected by bubbles.
2. Description of Related Art
Liquids are typically supplied through pipes to equipment in manufacturing plants. This requires the use of numerous joints and couplings to connect sections of pipe, and leakage of liquid from these joints is common. Depending on the type of liquid being used, regular manual inspection is required to check for leakage. Typical liquid leakage detection methods include conductive and volumetric techniques. Japanese Examined Patent Application Publication (kokoku) 4-70572 teaches a liquid leakage sensor technology for reliably detecting liquid leakage by emitting light from a light source to a filter that turns transparent when it absorbs liquid, producing a change in light transmitted or reflected by the filter when there is liquid leakage. This change in transmitted or reflected light is used to reliably detect liquid leakage.
FIG. 1A illustrates the principle of this conventional reflection type liquid leakage sensor 20. A test paper and case holder 4 of which the bottom 4a is coated black is fastened by a screw or other fastener 6 to floor 1, and a white test paper (or cloth or synthetic resin) 8 is placed flat over bottom 4a. The bottom 4a is also a reflector. A case 12 of which the bottom 12a is transparent or semi-transparent is inserted to holder 4. A light source 14, photodetector 16, and comparator or other detection means 18 are together housed inside the case 12 and connected by way of cable 26 to the outside of the case 12.
It should be noted that the case 12 also functions as a dustproof and water-resistant cover. However, to facilitate penetration of leaked liquid 2 to the reflection area 8b in the middle of paper 8, and shorten the liquid leakage detection time, a gap 10 is disposed between paper 8 and the case bottom 12a. This gap 10 is preferably no more than several millimeters in order to avoid contamination by dust and other foreign particulate, and to stably detect light reflected from paper 8 without also detecting external light noise. Replacing the paper 8 and installation are also made easier by constructing the filter so that the reflector 4a and case 12 are removable. It is also not generally possible to identify the source of liquid leakage. As a result, the paper 8 is also preferably round so as to respond more quickly to liquid leakage from any direction.
A liquid leakage sensor 20 thus comprised emits light 22 from the light source 14, which is typically an LED, infrared laser diode, or optical fiber, to continuously monitor white reflected light 24 from the paper 8 by means of photodetector 16. However, when leakage 2 occurs at the floor 1, leaked liquid 2 gradually penetrates from contact area 9 to the reflection area 8b of paper 8, and the contact area 9 of paper 8 turns from white to transparent due to liquid absorption. Because the reflector 4a below the paper 8 is black, the color of the paper 8 changes from white to black in the contact area 9. Light 22 from the light source 14 is thus absorbed by the reflector 4a, significantly reducing the amount of light 24 reflected to photodetector 16. The detection means 18 thus detects this change in reflected light, and senses liquid leakage.
The following problems not initially expected to occur with a conventional optical liquid leakage sensor as described above remain to be solved.
(A) When the holder bottom 4a is level to the floor 1 and the case bottom 12a is also substantially level, a high pressure line or large-diameter pipe bursts and a large volume of liquid leaks at once, the entire circumference of the bottom of case 12 is submerged in liquid at substantially the same time. When the leaked liquid 2 then penetrates gradually from the outside edge of the paper 8 toward the inside, the air in the gap 10 between holder bottom 4a and case bottom 12a becomes trapped (although part of the air escapes outside the case 12 as a bubble) in the center of the gap 10 and surrounded by the liquid. As shown in FIG. 1B, this bubble becomes trapped in the center of the reflection area 8b, preventing the reflection area 8b from turning transparent no matter how much time elapses. As a result, it is not possible to detect that a large volume of liquid has leaked.
(B) Large numbers of flat holders having a level bottom 4a are currently in use. Replacing each of the holders 4 fastened to floor 1 would require a massive amount of time, and is substantially impossible.
(C) In addition, paper 8 is a consumable and is thrown away each time liquid is detected. It is therefore preferable to be able to reuse the paper 8  less than  less than  or eliminate use of the paper 8 greater than  greater than .
It should also be noted that the advantages of the liquid leakage sensor using paper 8 as described above include a simple design, reliable operation, stability and resistance to tipping over because it is fastened to the floor by a screw or other fastener, and the ability to detect high viscosity liquids in a relatively short period of time. On the other hand, users that would like to simplify or eliminate the work involved with installing the holder on the floor and replacing the test paper would like a liquid leakage sensor that does not use such paper and does not require floor installation.
Various liquid leakage sensors that do not use such a test paper have been proposed. These typically emit light to the bottom of the case, and evaluate the presence of liquid leakage by means of the amount of reflected light. However, if the case bottom is tight to the floor, it is very difficult for high viscosity liquids to penetrate to the middle of the case bottom. This means that the gap between the floor and the case bottom must be at the smallest at least 2 to 4 mm, which is significantly greater than in a sensor using paper as described above, and liquid leakage detection is not possible unless a large amount of liquid leaks so that the case bottom contacts the liquid.
Furthermore, if the case bottom is directly exposed to the floor surface, detection will be easily affected by the color of the floor surface, and when leaked liquid penetrates the sensor area, a large amount of unnecessary reflected light from the floor surface will also be detected, creating operating errors. Detection of liquid leakage based only on the amount of reflected light thus becomes unstable.
In addition, if the case is simply placed on the floor without fastening it to the floor, there is the danger of the case rising off the floor and even falling over.
The present invention was therefore conceived with consideration for the above-noted problems. An object of the invention is therefore to provide a liquid leakage sensor, paper for detecting liquid leakage, and a holder for detecting liquid leakage whereby liquid leakage can be stably and reliably detected without leakage detection being affected by bubbles even when a large volume of liquid leaks at one time.
A further object of the present invention is to provide a liquid leakage sensor, paper for detecting liquid leakage, and a holder for detecting liquid leakage whereby leakage of volatile liquids presenting the danger of flammable explosion can be remotely, safely, and reliably detected while taking care to prevent explosion and without leakage detection being affected by bubbles even when a large volume of liquid leaks at one time.
A yet further object of the present invention is to provide a liquid leakage sensor having a tilt detection function that does not use paper and can reliably, quickly detect liquid leakage even when the leaked liquid does not contact the case bottom.
To achieve this object, the present invention relates to a liquid leakage sensor comprising a white test paper that is made transparent by absorption of leaked liquid; a paper holder for holding level a test paper placed therein with the bottom of the paper holder forming a reflector; a case inserted to this holder and having a transparent or semi-transparent bottom; a light source for emitting light to the test paper through the transparent or semi-transparent bottom; a photodetector for detecting light reflected from the holder bottom; and a detector for detecting liquid leakage based on data from the photodetector. The light source and photodetector are housed together inside the case. A gap is formed between the holder and case so that leaked liquid penetrates rapidly when leaked liquid contacts one edge of the paper.
To achieve the above object with a liquid leakage sensor thus comprised, an asymmetrical opening is formed asymmetrically to the reflection area in a middle part not including the outside edge and reflection area of the paper when the shape of the paper is circular or noncircular so that a bubble is not trapped in the reflection area of the paper that is detected by the photodetector when a large volume of liquid leaks at once.
The present invention also relates to a liquid leakage sensor having at least one reflection plane able to contact leaked liquid, a light source, and a photodetection means. In this case, the object of the invention is achieved by projecting light to the reflection plane from the light source; detecting light reflected from the reflection plane by a plurality of photodetection means; applying an operation to photodetection means output to determine a brightness pattern distribution of the reflected light at a specific period; and determining the presence of liquid leakage from variation in the brightness pattern distribution of the reflected light.
The invention further relates to a liquid leakage sensor having at least one reflection plane able to contact leaked liquid; a case having a transparent or semi-transparent bottom; a light source for emitting light; a first light transmitting means for guiding light emitted from said light source to said reflection plane through the transparent or semi-transparent case bottom; a second light transmitting means for detecting and transmitting reflected light from the reflection plane; and a photodetection means for detecting light from said second light transmitting means.
A liquid leakage sensor thus comprised achieves an object of the present invention by forming an optical path from an end of the first light transmitting means and an end of the second light transmitting means housed inside the case. The second light transmitting means has a plurality of light transmitting elements whereby light is transmitted so that reflected light photodetection positions can be mutually distinguished. Positions at which reflected light is detected by the plural photodetection elements are converted at the other end of the second light transmitting means to electrical signals so as to be mutually distinguishable. Output of the photodetection means is then processed to determine at a specific period a brightness pattern distribution of the reflected light. Presence of liquid leakage is then detected from change in the brightness pattern distribution of reflected light.
An object of the present invention is further achieved by means of liquid leakage sensor having a first liquid leakage sensor and a second liquid leakage sensor. The first liquid leakage sensor has a first detection means having at least two reflection planes able to contact leaked liquid formed with a gas layer or a leaked liquid permeation layer disposed therebetween in the direction of light transmission; at least two light sources and photodetection means disposed on the same side of each reflection plane; emitting light from a first light source at an incidence angle equal to or greater than a critical angle to a first reflection plane nearest said light source; detecting reflected light from said first reflection plane by means of a first photodetection means; and processing said photodetection means output to detect liquid leakage. The second liquid leakage sensor has a second detection means for emitting light from a second light source at an incidence angle less than said critical angle to a reflection plane other than said first reflection plane, detecting reflected light from a reflection plane other than said first reflection plane by means of a second photodetection means, and processing said photodetection means output to detect liquid leakage.
Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings.

Liquid leakage sensor, paper for detecting liquid leakage, and holder for detecting liquid leakage


A segmented stretch waveform for wide band high duty cycle tracking application. The waveform is divided into multiples of two spaced segments as the tracking range closes. Target returns received during spaced segments are combined to correspond to the complete waveform; and range is determined in accordance with the combined waveform. Tracking range can be varied without changing bandwidth, FM slope, duty cycle or processing time.

1. Field of Invention
The present invention relates to a radar system and related method; and more particularly to a radar system and method, having the ability to vary the tracking range.
A continuous wave radar (CW) and a high pulse repetition frequency (PRF) radar are similar in that a high PRF in its basic form is a CW radar pulsed on and off at a high rate, such as several hundred kilohertz, for example; and the receiver is protected from direct transmitter leakage by a switch which is opened during the transmit period. However, in practice high PRF pulse Doppler (PD) radars are far more complex and are more effective against low flying aircraft in a heavy clutter background, in that they can discriminate more effectively between ground clutter and moving targets on a Doppler frequency basis. High average power can also be transmitted in that such system typically have approximately a 50% transmission duty factor; that is, the duration of the waveform is approximately the same as the interpulse period.
A linear FM waveform which is generated and compressed by a compression filter is sometimes referred to as a chirp waveform and is relatively simple to generate. Stretching and compression of a linear FM waveform is accomplished to retain the detection capability of a waveform of long duration while at the same time retaining the range resolution of a short pulse. A stretched waveform is generated actively by oscillator tuning a digital synthesis; and is demodulated by the first local oscillator and processed via Fast Fourier Transform. The waveform is generated from a narrow linear FM waveform by changing the relative phases of the frequency components of the waveform by a filter that distorts the phase; thus producing a stretch waveform, which is the waveform that is transmitted. The received echo is processed in a compression filter that readjusts the relative phases of the frequency components so that a narrow linear FM chirp signal is received.
One ranging method used with CW and high PRF PD radar is multiple PRF ranging which uses a moderate duty factor of one tenth or less and multiple range gated receivers. The receivers are sequentially opened for a period equal to the transmitted pulse width. A target will fall in only one or two receiver channels, which is an ambiguous range measurement; and ambiguity is resolved by cycling through several PRF's.
Another method of ranging a CW or high PRF PD radar is accomplished by applying linear frequency modulation (FM) to the microwave oscillator of the system for a short period during each transmit cycle. This application of FM modulates both the transmitted frequency and receiver local oscillator frequency, which produces a frequency or Doppler shift in the return signal that is range dependent. Thus, target signal frequency is the sum of the range frequency and Doppler frequency. By comparing with the target signal frequency when no FM is applied, the range component can be computed and displayed.
In a typical CW or high PRF linear FM Doppler radar system, a stretched waveform of a bandwidth .DELTA.F is transmitted during a time period .DELTA.T. During the receive cycle, the FM is removed by an identical .DELTA.F, .DELTA.T from the return signal. The target range where a radar return falls that is synchronous with the sweep time .DELTA.T generates a CW signal of duration .DELTA.T at an intermediate center frequency F0. Thus, the range resolution is proportional to the reciprocal of the bandwidth .DELTA.F in accordance with the following equation. ##EQU1##
Where;
K1=system processor FFT Weight widening PA1 K2=widening due to return signal nonsynchronous with sweep, PA1 dR=range resolution, PA1 .DELTA.F=transmit bandwidth. PA1 c=Velocity of light
The minimum range is determined by the transmit time .DELTA.T. Thus, varying the tracking range can be achieved by varying .DELTA.T while retaining .DELTA.F at the same value. If the tracking range is to be reduced, the resolution dR in equation 1.0 remains constant, but the FM slope is increased given a constant receiver IF bandwidth. This, however creates a waveform synthesis problem. It is difficult to reduce .DELTA.T by an appreciable factor, and still sweep the relatively wide .DELTA.F bandwidths usually required. If constant range coverage were required, a varying IF bandwidth and digital sampling rate change would be necessary, which is cumbersome. Such a stretch system also limits the minimum range resolution and requires an increase in the slope of the FM waveform.

Radar system and method having variable tracking range


A non-volatile one time programmable memory cell couples in series a two terminal fuse and a three terminal antifuse. The non-volatile one time programmable memory cell includes a memory cell write enable node and a memory cell output node. The non-volatile one time programmable memory cell includes fuse having a first node and a second node, and an antifuse having a trigger node, a first node, and a second node. The trigger node is coupled to the memory cell write enable node. The first node of the antifuse and the second node of the fuse are coupled to the memory cell output node. First and second voltages appearing at the memory cell output node are indicative of first and second binary states of the memory cell. A plurality of such memory cells can be included in a non-volatile programmable memory array. A non-volatile programmable memory cell capable of re-programming is also included.

An integrated circuit memory cell is a circuit capable of storing a predetermined number of logic states, most often two logic states. Based on a capacity of retaining or not retaining a memory state under no power conditions, memory cells can be classified as non-volatile or volatile. In particular, a non-volatile (NV) memory cell is capable of retaining its memory state when powered off. In contrast, a volatile memory loses its memory state when powered off.
All integrated circuit non-volatile programmable memory cells include an alterable element that can be altered from a first condition to a second condition, and which retains its second condition even when power is turned off.
The above-described alteration of the alterable element from the first condition to the second condition is usually referred to as programming the memory cell. In some arrangements, the programming is achieved when the alterable element is subjected to specific voltage, current, or voltage-current (power) condition by means of additional supporting circuitry (i.e., a driver). One time programmable non-volatile memory cells (OTP NV) are a type of non-volatile programmable memory cells, for which programming is not reversible.
In a conventional non-volatile programmable memory array having a plurality of non-volatile programmable memory cells, each memory cell has a particular address location, and therefore requires an address decoder circuit plus a write driver circuit and also a read sensing circuit in order to uniquely program (i.e., write) to or read from a respective memory cell.
In some arrangements, address decoding circuits and read sensing circuits can be shared among memory cells. However, write driver circuits are usually not shared among memory cells, and therefore, each memory cell in a memory array has its own write driver circuit. Write driver circuits are known to be physically large, as they are required to have low source resistances at high current levels. Being physically large, write driver circuits tend to limit the number of non-volatile programmable memory cells that can be fabricated into a memory array in an integrated circuit.
In some conventional non-volatile programmable memory arrays having a plurality of non-volatile programmable memory cells, a state of each memory cell, programmed or unprogrammed, is sensed by a respective read sensing circuit.
State detection margin error, power consumption, access time, and silicon area constraints are all tradeoffs that affect the design of read sensing circuits. The requirement for read sensing circuits also tends to limit the number of non-volatile programmable memory cells that can be fabricated in an integrated circuit.
In addition, many types of non-volatile programmable memory cells draw a different amount of current depending upon their logic state. Thus, a conventional non-volatile programmable memory array having a plurality of non-volatile programmable memory cells can draw different amounts of current depending upon the states of memory cells within the memory array and how it is accessed or read. For some electronic systems, this variation may be undesirable.
It would be desirable to have a non-volatile programmable memory cell and an associated non-volatile programmable memory array that can be fabricated with a conventional integrated circuit process and that can achieve a high density of non-volatile programmable memory cells but with a low operational power consumption and a high noise margin state detection.

Non-volatile programmable memory cell and memory array


A photographing apparatus includes a photographing plan memory for setting photographing conditions based on a predetermined photographing plan, a vibration sensor for detecting vibration caused by an explosion of a balloon serving as a photographic subject, and a trigger generating circuit for taking in the timing of detection by the vibration sensor as a trigger. The above photographing plan is prepared beforehand for changing from low-speed photography to high-speed photography in response to the trigger, and changing from high-speed photography to low-speed photography after acquiring “40 frames”. With this plan, the low-speed photography is adopted before and after the balloon explosion, an amount of photographic data tends to be small. Photographs may be taken out within limited photographic data, even with a limited memory capacity. At a moment of balloon explosion, rapid variations due to the explosion may be photographed by high-speed photography with high accuracy.

(1) Field of the Invention
This invention relates to a photographic apparatus such as a video camera, and a photographic method using this apparatus. More particularly, the invention relates to a photographic technique for use in scientific measurement concerning fast moving bodies such as rockets, explosion, turbulence, electric discharge, movement of microbes under a microscope, and signal transfer of the brain and nervous system.
(2) Description of the Related Art
A conventional high-speed photographic apparatus (high-speed video camera) has fixed photographing intervals, i.e. a fixed photographing speed, when performing a series of photographic operations. At a moment a phenomenon occurs with a photographic subject, the occurrence varies rapidly. It is therefore desirable to photograph the photographic subject at short intervals, i.e. at high speed, in order to secure detailed results. On the other hand, before or after the occurrence of a phenomenon, variations are slow. It is desirable to photograph the photographic subject at relatively long intervals, i.e. at low speed. The term "photographing interval" used in this specification represents time per unit frame (the unit being seconds per frame). The "photographing speed" represents the number of frames per unit time (the unit being frames per second). That is, the photographing speed is the inverse of the photographing interval.
(I) However, with a high-speed camera having a fixed photographing speed, short photographing intervals resulting in an increased amount of photographic data, or a limited memory capacity, makes a whole series of photographic operations impossible. Conversely, long photographing intervals will result in a failure to photograph rapid variations.
(II) When obtaining image information for checking variations occurring with a photographic subject in greater details, that is when obtaining image information for a plurality of frames in a unit photographing time, as shown in the timing chart of FIG. 1, a light source is driven a plurality of times (three times in FIG. 1) to illuminate the photographic subject within one exposure time t1. In this case, it is necessary to use a special laser light as the light source in order to illuminate the subject at minute intervals with high accuracy.
Since the unit photographing time and exposure time are fixed for a series of photographic operations, that is since one exposure is carried out within the exposure time, image information cannot be obtained to reflect variations occurring with the photographic subject with high accuracy. When photographing an explosion accompanied by self-flashing, for example, rapid variations accompanied by flashing take place at a moment of occurrence of the phenomenon. Therefore, an exposure time for avoiding halation due to an excessive quantity of light entering the device is taken into account, and a short unit exposure time is set. However, after the occurrence of the phenomenon, photography is continued with the same conditions despite a reduction in the quantity of light by flashing and a slackening in the variations of the phenomenon. Consequently, dynamic images all clear from beginning to end cannot be obtained based on a series of image information obtained.
When obtaining image information for a plurality of frames in a unit photographing time, a multiple exposure is carried out by driving the light source a plurality of times during one exposure within the unit photographing time. Thus, all the image information obtained from one exposure is displayed in superimposition on one image. As a result, it is difficult to distinguish and check image information on the dynamic image.
Since the conventional apparatus has the unit photographing time and exposure time remaining fixed for a series of photographic operations, it is a complicated operation to set optimal conditions for photographing a photographic subject, with an additional drawback of increased cost. That is, in order to obtain clear image information, duplication experiment must be carried out by varying the exposure time a plurality of times before production photography.

Photographic apparatus and photographic method using same


A protective endcap for use with a triaxial cable connector. The endcap is sized to fit about a mating end of the triaxial connector. A pair of protective boots for use with coaxial cable connectors. Each protective boot includes an interior space for receiving a triaxial cable connector. Each interior space includes ridges for engaging grooves about the connector. Each boot includes a mating circumferential lip about a connector end. Each boot includes a tapered cable end with an opening for a cable from a connector to extend through from the interior space. A triaxial cable connector assembly including a connector, a protective boot and an endcap. The connector is positioned within an interior opening of the boot with ridges of an inner wall of the opening engaging grooves of the connector. A cable extending from the connector extends through a cable end of the boot. A mating end of the connector is adjacent a connector end of the boot. The endcap is mounted about the mating end of the connector and includes a circumferential lip which engages a mating circumferential lip of boot.

Broadcast communications equipment communicate electrical signals via triaxial cables which are well known. A variety of triaxial cable connectors of different styles and formats are known as well. Examples of such cables and connectors may be found in U.S. Pat. Nos. 5,967,852; 6,109,963; 6,539,161; and 6,665,484.
These known triaxial cable connectors are fairly durable and resistant to contamination when mated to a corresponding connector. However, it is desirable to improve the resistance to impact and to intrusion of contaminants for mated pairs of connectors.
It is also desirable to provide a device for covering the mating ends of triaxial cable connectors when the connectors are not mated with another connector. These triaxial cable connectors may be covered by a protective boot and improvements to these protective boots are desirable. Protection of bulkhead mounted triaxial connectors which are not mounted to cables is also desirable.


A supplemental oxygen assembly for a vehicle can include a container and a flow assembly attached to and/or configured to be contained within the container in a stowed position and to extend from the container in a deployed position. The flow assembly can be configured to be connected to an oxygen supply to supply oxygen to a person in the deployed position. The supplemental oxygen assembly can include an extension device connected to the flow assembly. The extension device can be configured to extend or allow extension of the flow assembly toward an aisle of the vehicle to aid the flow assembly in being reached from or moveable toward an aisle of the vehicle by a person in the aisle.

In certain vehicles having supplemental oxygen assemblies, a crew member may have difficulty reaching an oxygen mask in an emergency where there are privacy barriers and/or other distance issues from an aisle to a location where the oxygen mask drops out. In some cases, regulations require certain access limits are met assuming a certain sized crew member. In view of this, traditional vehicles must limit the size/width of the passenger seating areas, and/or must limit the privacy features available in order to comply.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved supplemental oxygen assemblies. The present disclosure provides a solution for this need.


An apparatus and a method for detecting cardiac atrial fibrillation events in an EKG signal. The method comprises the steps of detecting a portion of an EKG signal comprising cardiac beats; measuring the duration of a gap in the detected portion of the EKG signal; and computing two or more inter-beat intervals. The computed interval is outputted if the gap in the portion of the EKG signal is not more than a fraction alpha of the computed interval. The method further includes the steps of computing the variance of the inter-beat intervals and classifying the portions of the EKG signal as indicative of an atrial fibrillation event. During classification, the inter-beat interval variance of the portion of the EKG signal that exceeds a pre-determined value V is indicative of an atrial fibrillation event. The method further includes discarding portions of the EKG signal classified as indicative of atrial fibrillation if said portions have a duration less than a pre-determined threshold S and annotating the EKG signal. The non-discarded portions of the EKG signals having inter-beat variances that exceed V are annotated as atrial fibrillation events.

Continuous physiological monitoring can play a crucial role in finding and treating asymptomatic pathologies in patients before they become life threatening. Examples of useful physiological data that can be collected and analyzed include electrocardiograms (EKG), blood oxygen levels, weight, blood pressure and many others.
In a typical continuous monitoring system, patients wear devices that collect data of interest continuously and the data is aggregated and transmitted to a remote host for further analysis. Settings like this are of particular interest for diseases like Atrial Fibrillation (Afib) which are both asymptomatic and intermittent. Continuous monitoring using wearable EKG's can provide the information necessary to diagnose and treat the disease.
Unfortunately, in the typical monitoring environment, a variety of factors conspire to reduce the quality of the signal. Noise due to patient mobility, packet loss due to wireless problems, aggregating device buffer overruns and other problems result in losing some fraction of the data being collected by the device. There is a need in a method and a device for detecting atrial fibrillation events in a signal transmitted in a lossy data stream.

Method and apparatus for improving the accuracy of atrial fibrillation detection in lossy data systems

Hewlett-Packard Development Company, L.P.


Provided area carbon nanotube composite material obtained by treating a mixture including carbon nanotubes, at least one carbon compound other than carbon nanotubes and a dispersion medium under a sub-critical or super-critical condition of 50-400 atm, and a method for producing the same. More particularly, the method for producing a carbon nanotube composite material, includes: introducing a mixture including carbon nanotubes, at least one carbon compound other than carbon nanotubes and a dispersion medium into a preheating unit under a pressure of 1-400 atm to preheat the mixture; treating the preheated mixture under a sub-critical or super-critical condition of 50-400 atm; cooling and depressurizing the resultant product to 0-1000 C and 1-10 atm; and recovering the cooled and depressurized product. Provided also is an apparatus for producing a carbon nanotube composite material in a continuous manner.

Since the structure of carbon nanotubes (CNTs) was found in 1991 for the first time, intensive studies about the synthesis, physical properties and application of CNTs have been conducted. In addition, it was found that CNTs are produced upon the addition of a transition metal, such as Fe, Ni or Co, during electric discharge. Since a substantial amount of samples was made by laser evaporation in 1996, studies of CNTs have been raging. Such CNTs have a hollow tube-like shape wound spherically at a graphite surface with a nano-scaled diameter. Herein, depending on the angle and structure of such winding of the graphite surface, CNTs are characterized electrically as conductors or semiconductors. Further, CNTs are classified, depending on the number of graphite walls, into single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), thin multi-walled carbon nanotubes, multi-walled carbon nanotubes (MWCNTs) and roped carbon nanotubes.
In particular, CNTs have excellent mechanical strength and elasticity, are chemically stable and eco-friendly, and show electrically conductive or semiconductive properties. In addition, CNTs have a diameter of 1 nm to several tens nanometers and a length of several micrometers to several tens micrometers. Therefore, CNTs have an aspect ratio of about 1,000 and thus are larger than any known materials. Further, CNTs have a very large specific surface area, and thus have been spotlighted as an advanced material leading the 21st century in the fields of next-generation information electronical materials, high-efficiency energy materials, highly functional composite materials and eco-friendly materials.
Such CNTs are used currently as conductive and reinforcing materials not only in polymers but also in other matrix materials, such as ceramic, metal, etc. Under these circumstances, active studies of CNTs for use in such applications have been made currently. Particularly, many attempts have been made to obtain highly conductive composite materials as high-added value materials by mixing CNTs with other materials in order to overcome the problems of high cost of original materials (CNTs) used alone and poor dispersibility thereof, when using CNTs as materials for improving certain physical properties, including conductivity, in matrix materials, such as polymers.
Korean Patent No. 706652 discloses an electrically conductive thermoplastic resin composition, including 80-99 parts by weight of a thermoplastic resin; 0.1-10 parts by weight of CNTs; and 0.1-10 parts by weight of organic nanoclay.
In addition, Korean Patent Laid-Open No. 2006-52657 discloses a composition, including: 99.6-10 parts by weight of a thermoplastic resin; 0-50 parts by weight of at least one rubber-elastomer; 0.2-10.0 parts by weight of carbon nanofibrils; 0.2-10.0 parts by weight of at least one microparticulate carbon compound, preferably carbon black or graphite powder; and 0-50 parts by weight of at least one filler and/or reinforcing agent.
However, the above compositions still have problems in that CNTs are not dispersed well in a matrix so that they realize maximized functions, and the intermiscibility of the resultant composite materials is too low to form electroconductive flow. Thus, to obtain a desired degree of conductivity, an undesirably large amount of CNTs and composite materials is used, resulting in degradation of the physical properties of the matrix.

Blending improvement carbon-composite having carbon-nanotube and its continuous manufacturing method and apparatus


The invention relates to a digital bus interface for an operating device for a lighting means comprising: a transmitting branch and a receiving branch, wherein the receiving branch has a current source (Q90, Q95, R90, R91), which can be fed from a bus that carries voltage in the idle state, wherein the current source supplies at least the transmitting branch with energy and the transmitting branch has an optocoupler (U91), wherein an electrical energy store (C95) is provided in the receiving branch, which electrical energy store is charged by the current source and discharges via a resistor (100) in series with the secondary side of the optocoupler (U91) of the transmitting branch.

An interface for DALI control signals which comprises a transmitting channel and a receiving channel both of which can be operated with a common current source is known from DE 10 2009 016 904 B4. The circuit according to the prior art is shown in FIG. 1.
In the known circuit, corresponding optocouplers U2, U1, which each form part of a branch for transmitting or respectively receiving, are provided both for the reception of DALI signals and also for the transmission of DALI signals. Both branches are fed from the common current source Q2, Q3, R3, R4. The circuit further comprises an energy store, which is illustrated in FIG. 1 as the capacitor C2.
The known interface is designed for a communication according to the DALI standard in which a specified DC-voltage is present on the lines in the case of an inactive bus. This specified DC-voltage is reduced respectively only in the case of a signal communication, while the constant DC-voltage is again present when no signals are being communicated.
According to the prior art, the capacitor C2 is charged by the DC-voltage present in the bus. This is meaningful here because, if a signal communication according to the DALI standard is taking place, precisely the voltage present in the bus falls to (logical) zero or respectively to the voltage which is defined for the low-level voltage. This can be detected directly in the return channel (transmitting branch) of the circuit.
"Return channel" relates to the channel away from the interface as the channel for the transmitting mode of the interface. The "transmitting branch" is accordingly the signal path of the interface used for the transmission of signals.
However, if signals according to a protocol in which the voltage is zero (or very low by comparison with the DALI standard) in the non-operating state of the bus are received by the interface instead of DALI signals, the known interface may then not be suitable for this. An example for such a standard is the so-called DSI standard.
The reason for this is that, by contrast with the DALI standard, according to the DSI standard, no voltage or respectively a low voltage is present in the case of an inactive bus (the "low level", that is, the low value for the transmission of a first logical state, for example, 0, is specified at <6.5 V). The voltage in the bus is raised only in the case of a transmission of a DSI signal.
Consequently, if a DSI signal arrives at the terminal for the operating device, that is, at the secondary side of the known interface, the voltage jumps abruptly from the value for the first logical state, for example, < 6.5 V, to a specified DC-voltage, for example, 10-15 V (high-level, that is, the voltage value which is interpreted as the second logical value, for example, 1). It is now.necessary for the incoming signal to be detected immediately in order to guarantee a reliable detection of the DSI signal. In the case of DSI, the transmission takes place with a Manchester coding, that is, one data bit is transmitted through a change from low-level to high-level (logical 0) or respectively a change from high-level to low-level (logical 1).
However, in this context, the capacitor C2 from the known circuit acts in a disturbing manner, because the falling edge (logical 1) or respectively the first bit of the DSI signal cannot be reliably detected by the known interface.
This is because, after adopting the high-level (for approximately 833 μs), the capacitor C2 is partially charged as a result of the 2 mA input current source. In the case of a decline of the bus voltage to below 6.5 V, the capacitor C2 is further charged. In consequence, current also flows in the optocoupler U2 of the receiving branch, and the first logical state (for example, 1) cannot therefore be detected at the optocoupler output of the optocoupler U2 immediately after falling below 6.5 V. The capacitor C2 is in fact still partially charged even after the undercutting of the low-level and, in the non-charged or partially charged state, bridges the Zener diode Z1, which otherwise immediately interrupts the current flow in the optocoupler U2 when the Zener voltage (low level) is undercut.

Interface having an improved transmitting branch


This invention discloses an entertainment system for providing entertainment to a user thereof, the system including an entertainment source for providing entertainment in a distributable form, entertainment distribution apparatus for distributing the entertainment and a plurality of entertainment delivery units, each entertainment delivery unit including receiving apparatus for receiving the entertainment from the entertainment source via the entertainment distribution apparatus, wherein at least one of the plurality of entertainment delivery units includes personalization apparatus adapted to receive a removable personalization element including personalization information, and the at least one of the plurality of entertainment units personalizes the entertainment based on the personalization information, and the personalization information includes at least one of the following: entertainment preference information; gaming information; and telecommunications information.

Multi-user entertainment systems, particularly those intended for use within an enclosed area such as a building or a vehicle, particularly an airplane, are well-known in the art. Such entertainment systems and components useful therein are described, for example, in the following US patents:
U.S. Pat. No. 4,835,604 to Kondo et al.;
U.S. Pat. No. 4,896,209 to Matsuzaki et al.;
U.S. Pat. No. 4,887,152 to Matsuzaki et al.;
U.S. Pat. No. 4,866,515 to Tagawa et al.;
U.S. Pat. No. 4,584,603 to Harrison;
U.S. Pat. No. 5,539,657 to Utsumi et al.;
U.S. Pat. No. 4,428,078 to Kuo;
U.S. Pat. No. 5,289,272 to Rabowsky et al.;
U.S. Pat. No. 5,220,419 to Sklar et al.;
U.S. Pat. No. 5,214,505 to Rabowsky et al.;
U.S. Pat. No. 4,958,381 to Toyoshima;
U.S. Pat. No. 4,521,021 to Dixon;
U.S. Pat. No. 4,647,980 to Steventon et al.;
U.S. Pat. No. 4,008,369 to Theurer et al.;
U.S. Pat. No. 4,920,432 to Eggers et al.;
U.S. Pat. No. 5,051,822 to Rhoades;
U.S. Pat. No. 4,247,106 to Jeffers et al.;
U.S. Pat. No. 3,997,718 to Ricketts et al.;
U.S. Pat. No. 4,057,829 to Moorehead;
U.S. Pat. No. 4,591,906 to Morales-Garza et al.;
U.S. Pat. No. 4,554,579 to Citta;
U.S. Pat. No. 4,513,315, to Dekker et al.
A direct broadcast TV satellite system for use in aircraft is described in "Direct Broadcast Satellite TV For Airborne Applications", by Hughes-Avicom International, Inc., copyright 1996.
An in-flight entertainment system called Mitsubishi TD 120 is described in a brochure by Mitsubishi Electronics America, Inc., entitled "Making Digital Entertainment Fly", copyright 1996.
Non-program uses of subscriber television are described in U.S. Pat. Nos. 5,539,450 and 5,592,212 to Handelman.
The disclosures of all references mentioned above and throughout the present specification are hereby incorporated herein by reference.


This invention relates to a method for testing a plastic sleeve for use with an image cylinder or a blanket cylinder in an electrophotographic process.

In electrophotographic processes requiring an image cylinder and a blanket cylinder to produce electrophotographic copies, the image cylinder typically receives a uniform charge, an image-wise charge reduction, and a toner coating on the resultant image area, and then transfers the toner image to a blanket cylinder. The blanket cylinder transfers the toner image to a substrate, such as paper or the like, which passes via a web between the blanket cylinder and a back pressure roller to transfer the toner image to the substrate with the substrate thereafter being fused, as well known to the art.
In such processes, the image cylinder has a cylinder that typically includes a mandrel, which may be of aluminum, steel or any other suitably durable metal or conductive plastic of a suitable thickness to produce a noncompliant member that may be about 10 millimeters (mm) in thickness. The mandrel may include reinforcing structure internally and includes a very smooth, low out-of-round tolerance exterior. The image cylinder includes a mandrel and a sleeve positioned over the outside of the mandrel and is used for production and transfer of the images to the blanket cylinder. The mandrel also includes bearings connected to each of its ends for positioning it in an electrophotographic copying machine and has an air inlet into an interior of the mandrel for an air discharge through a plurality of holes placed around one end of the mandrel near a tapered end of the mandrel.
The blanket cylinder has a cylinder that typically includes a mandrel, which may be of aluminum, steel or any other suitably durable metal or conductive plastic of a suitable thickness to produce a noncompliant member that may be about 10 millimeters (mm) in thickness. The mandrel may include reinforcing structure internally and includes a very smooth, low out-of-round tolerance exterior. The blanket cylinder includes a mandrel and a sleeve positioned over the outside of the mandrel and is used for transfer of the images from the blanket cylinder to a substrate. The mandrel also includes bearings connected to each of its ends for positioning it in an electrophotographic copying machine and has an air inlet into an interior of the mandrel for an air discharge through a plurality of holes placed around one end of the mandrel near a tapered end of the mandrel.
The sleeves have been produced by use of a metal core, which is typically a noncompliant metal member, such as nickel or the like, which is produced by plating. The core must be seamless and must provide a very low variation surface outer diameter. The plastic layer is then positioned around the outside of the metal core, the metal core is mounted on a mandrel or the like, and the plastic layer is machined to a desired thickness. Recently processes have been proposed that do not require a core. Additional exterior coatings have been applied to the sleeves by techniques such as ring coating and the like. The completed sleeve will have an internal diameter slightly less than the outer diameter of the mandrel upon which it is to be placed. This interference fit allows the sleeve to be firmly positioned on the outside of the mandrel after it is installed. The sleeve must have a smooth exterior and a closely controlled wall thickness.
The sleeve is typically installed by urging it toward and onto the tapered end section of the mandrel while air is ejected through the holes at the end of the mandrel near the tapered section. The air injection permits the positioning of the sleeve on the mandrel by an air bearing technique as known to those skilled in the art. The interference fit between the sleeve and the mandrel is accomplished and the sleeve is retained snugly and firmly in position on the outside of the mandrel. The outside of the mandrel, including the sleeve, must have an outside diameter variation within a range of about ±12.5 microns. This close tolerance is necessary to ensure accurate receipt of images from the image cylinder and transmission of the images to the substrate by the blanket cylinder.
There are various other specific requirements for the blanket cylinder and it has been previously considered necessary to meet these other requirements as well as those discussed above by the use of a metal core in the sleeve. This is a relatively expensive, time-consuming step and the cores are relatively expensive. As a result, a continued effort has been directed to the development of methods for producing sleeves more economically that will meet the demanding requirements for the blanket cylinder sleeves.

Method for testing a plastic sleeve for an image cylinder or a blanket cylinder


A trigger operated dispensing device for the discharge of fluids, particularly in a spray. The device comprises a housing including a trigger, which actuates a flexible pump. The flexible pump has an inlet accepting the fluid and an outlet end through which the fluid passes going to the discharge. The flexible pump, preferably of bellows type, is situated in line with and just adjacent to the discharge wherein rotational motion of the trigger results in rotational compression of the pump chamber. In a particularly preferred embodiment, the flexible pump further includes mechanical structure for imparting a radial momentum to the fluid prior to discharge.

Dispensing devices for discharging fluid from a supply container, particularly in a spray, are widely known in the prior art. These fluid dispensers traditionally utilize a piston and cylinder as the pump chamber and a spring to provide the piston return force. They include a means for checking the flow of fluid into and out of the pump chamber and a means for discharging the fluid, preferably in a spray. Channels are incorporated into the dispensing device housing to provide a path for the fluid to and from the pump chamber. Examples of such dispensing devices are found in U.S. Pat. Nos. 4,153,203 (Tada) and 4,819,835 (Tasaki). One drawback to such dispensing devices is the great amount of friction between the piston and the cylinder due to the telescopic fit required to maintain a fluid tight seal. This friction, in conjunction with binding of the piston in the cylinder, are sources of energy loss, thereby increasing the required overall energy to dispense the fluid and the required spring energy to return the piston. In addition, the use of the dispenser housing to provide fluid channeling results in a complex part to manufacture. This, in conjunction with the many parts that go into a fluid dispenser of this type, increases the cost of the dispenser.
U.S. Pat. Nos. 3,973,700 (Schmidt), 4,225,061 (Blake), 4,260,079 (Cary), and 4,489,861 (Saito) reveal dispensing devices that utilize a flexible pump, specifically a bellows, to replace the function of the piston, cylinder and return spring. The use of such a flexible pump is substantially free of friction and binding losses associated with the piston and cylinder. However, these dispensing devices still utilize the dispenser housing to channel the fluid. In addition, little attempt is made to reduce the total number of parts in the dispenser assembly. Therefore complexity and cost are similar to the afore mentioned piston and cylinder dispensing devices.
Still other fluid dispensing devices utilize a diaphragm or bladder as the flexible pump. Examples of such are found in U.S. Pat. Nos. 3,749,290 (Micallef), 4,155,487 (Blake), and 4,310,107 (Wesner). These devices are substantially free of friction and binding losses associated with a piston and cylinder. However, these devices also utilize the housing for channeling the fluid, thereby increasing the complexity and cost of that part.
U.S. Pat. Nos. 4,898,307 (Tiramani) and 5,114,052 (Tiramani) reveal a dispensing device that utilizes a flexible pump, specifically a bellows, wherein a fluid channel is formed from the fluid supply container to the discharge nozzle by means of a dip tube and an integrally formed bellows and discharge tube. The bellows is positioned perpendicular to the discharge orifice and in line with the dip tube and as such must have coupling means with the dispensing device's trigger lever arm so as to transfer the rotational motion of the lever arm into translational compression of the bellows. The discharge tube is required to couple the bellows portion with the discharge nozzle and is positioned in line with and adjacent to the discharge nozzle. As such, the discharge tube must be bent 90 degrees with respect to the bellows in the assembled fluid dispensing device. Although this dispensing device eliminates the fluid channeling from the device's housing, the requirement of having to couple the bellows pump with the discharge nozzle through a discharge tube which must be bent 90 degrees with respect to the bellows in assembly makes for a costly and complicated part. In addition, the discharge tube is additional pressure drop between the bellows and the discharge nozzle. Further, since the discharge tube is formed integral with the bellows, it is made of the same resilient material. Dispensing devices of this type may store flow energy within the discharge tube thereby causing the discharge nozzle to dribble or not have clean flow cutoff.
Other prior art devices simplify the fluid channel by positioning the flexible pump in line with and adjacent to the discharge orifice. Examples of such fluid dispensers, utilizing a bellows as the flexible pump, are found in U.S. Pat. Nos. 2,774,518 (Greene), 3,124,275 (Lake), and 4,732,549 (von Schuckmann). These fluid dispensers provide means for a fluid channel comprising a dip tube, a bellows pump and a nozzle actuator. However, these fluid dispensing devices require direct coupling means between the displacement motion of the nozzle actuator and the compression of the flexible pump, wherein no mechanical advantage or lever action is provided. This is a drawback when the fluid dispenser is used to discharge higher viscosity fluids or fluids in a spray where high pressure losses are present. In addition, these fluid dispensing devices have discharge orifices that move with the motion of the nozzle actuator, thereby increasing the difficulty of depositing fluid with precision.
U.S. Pat. No. 4,101,057 (LoMaglio) discloses a dispensing device that utilizes a flexible pump, specifically a bladder, wherein the bladder is positioned in line with and directly adjacent to the nozzle discharge orifice. A coupling means is provided between a trigger and the bladder so that rotational motion of the trigger lever arm results in compression of the bladder. However, in order to complete the fluid path from supply container to discharge orifice, the dispenser incorporates channeling into the housing, thereby increasing the cost and complexity of that part.

Trigger operated fluid dispensing device


A tool for tightening and loosening a security nut and the security nut associated with the aforementioned tool that allow easy tightening of the security nut, makes it difficult to remove the security nut when using ordinary tools, and makes it easy to remove the security nut if the dedicated tool is used. The security-nut tightening tool used for screwing and tightening the conical, trapezoidal security nut onto a bolt comprises a hollow section that covers and seats the tapered outer surface of the security nut, a rotation grip section that protrudes above the hollow section, a head female-thread section that is linked to a hollow space along the axis of the rotation grip section and screws onto the bolt, an inner tapered surface that is fixed to the inner wall surface of the tool and has the same slope angle as the tapered outer surface and an elastic friction part.

1. Field of the Invention
The present invention is related to tools which are used for tightening and loosening uniquely formed nuts, such as tapered nuts, for the purpose of preventing crimes and, in particular, tools for tightening and loosening a conical, trapezoidal shaped security nut, and to the security nut associated with the tools.
2. Description of the Prior Art
The traditional head of the bolt and the nut, which are used for tightening, are typically hexagonal or multiple-sided in shape so that an ordinary person can tighten them using a tool easily available in the open market, such as a spanner or a monkey wrench. Therefore, pranks and crimes have begun to occur more frequently, such as removing the tightening section of a railroad as a prank or stealing an automatic vending machine by removing the fasteners.
To resolve these problems, Japanese Patent Publication #2000-205225 (to Tokkai), for example, discloses bolts and nuts that cannot easily be loosened or removed by an ordinary person. The head of the bolt and the nut are shaped as a multi-sided or non-arcing outer rim, while the surface of the outer rim is sloped and flared from the top toward the bottom. If these bolts and nuts are tightened using the special tightening tool that has a sloped wall in order to make contact with the sloped surface of the bolt or the nut, then these bolts and nuts cannot be removed using an ordinary tool available in the open market because ordinary tools cannot grip the sloped outer rim, and therefore crime can be prevented from occurring.
In the invention described in the aforementioned publication, the rotational torque for tightening is transmitted only by engaging the sloped wall of the dedicated tightening tool with the sloped surface of the bolt and nut. Therefore, in order for the bolt and nut to engage the dedicated tightening tool, the outer rims of the bolt and nut must be shaped as multi-sided or non-arcing. However, it is preferable to make the shape a conical trapezoid because this shape is most difficult to rotate and thus the most effective in terms of crime prevention. However, with the conical trapezoid shape there is a problem in which the aforementioned dedicated tightening tool cannot be engaged, meaning that the bolt and nut cannot be rotated. Moreover, a complex manufacturing process is required for production of the multi-sided shape, which is impractical due to the high costs of labor and production.
Even though security has to be improved, sometimes the nuts and bolts must be removed, such as when there is a need to relocate an automatic vending machine. When removing the nuts, much greater torque is required for loosening than tightening. However, the process of removal has never been considered in the design of the nuts or in regard to the dedicated tightening tool described in the aforementioned publication. Thus there is a problem in which the removal of nuts is quite difficult due to poor torque transmittal.
Furthermore, to improve security it must be difficult to remove the nuts using other common tools such as pliers, in addition to a spanner or a monkey wrench, both of which are commonly used to tighten and loosen ordinary nuts.
What is thus desired is to provide a dedicated tool for tightening the security nut, a tool for loosening the security nut, a tool for tightening/loosening the security nut, and the security nut associated with these tools that will allow easy tightening of the security nut, make it difficult to remove the security nut when using ordinary tools, and making it easy to remove the security nut if the dedicated tool is used.

Security nut and tool associated therewith


The invention relates to an image processing device (1, 48, 51) including: several image signal inputs (2-9) for receiving a respective image input signal, the signals being unsynchronized; at least one image signal output (23-26) for emitting at least one image output signal; a combiner (22) for combining the different image input signals to form the image output signal; several synchronizers (14-21), which are respectively connected downstream of the image signal inputs (2-9) and which synchronize the unsynchronized image input signals; and several distorters or rectifiers for distorting or rectifying the individual image input signals before they are combined to form the image output signal. According to the invention, the distorters or rectifiers are formed by the individual synchronizers (14-21) and the image input signals are distorted or rectified independently of one another by one or more synchronizers (14-21). The invention also relates to an associated operating method.

The invention relates to an image processing device and to an associated operating method.
In video systems and digital graphics systems, often different graphics signals have to be combined with one another to form a single graphics signal. This is the case for example when an object has been recorded in front of a so-called blue screen and must subsequently be blended into a background image, which has been recorded separately and is provided as a separate graphics signal.
Furthermore, it is known to perform geometry correction when combining a plurality of different graphics signals. This may be useful for example when the combined graphics signal is projected onto a curved projection surface or else in order to compensate any optical errors of the visualization device. In order to prevent a distorted image impression, the combined graphics signal may then be distorted in order to compensate the curvature of the projection surface.
It is also known to perform brightness or color correction when projecting or displaying graphics signals. This is useful for example when a plurality of projectors or screens is to generate a uniform overall image. In order to prevent different color rendering, the graphics signals may be distorted in terms of their color or brightness values so as to compensate any differences between the visualization devices.
However, one disadvantage of the known graphics systems for combining different graphics signals is the fact that they receive synchronized graphics signals on the input side. In practice, however, the graphics signals to be combined with one another are often asynchronous, which makes it more difficult to combine them using the known graphics systems or requires specially synchronized graphics systems.
Ulrich Schmidt: "Professionelle Videotechnik", Springer-Verlag (2000), page 483, FIG. 8.71 discloses an image processing device, which can receive different, unsynchronized image input signals on the input side and only then synchronizes them, whereupon the synchronized image input signals are then combined by means of a combiner to form an image output signal. This known image processing device therefore advantageously makes it possible to combine unsynchronized image input signals.
The use of so-called frame synchronizers for synchronizing unsynchronized image input signals is also known for example from "Ausbildungshandbuch audiovisuelle Medienberufe", Vol. 2, Hüthig-Verlag (2003), Section 220.127.116.11, pages 360-361.
Further image processing devices are known from:                Shawky, M.; Bonnet, S.; Favad, S.; Crubille, P.: "A Computing Platform and its Tools for Feature Extraction from On-Vehicle Image Sequences", IEEE Intelligent Transportation Systems Conference, 2000, Dearborn, Mich., USA, 1-3 Oct. 2000, Conference Proceedings, pp. 39-45.        DE 103 14 105 A1        DD 228 136 A1        LYNX Technik AG: "Series 3000 MiniModules. Product Catalog", company publication, S3000MM Ver 1.0., Weiterstadt: LYNX, 2003        LI, Kai; CHEN, Han; CHEN, Yuqun et al.: "Building and Using a Scalable Display Wall System", IEEE Computer Graphics and Applications, Vol. 20, No. 4, July/August 2000, pp. 29-37.        ALLARD, Jeremie; GOURANTON, Valerie; LECOINTRE, Loick et al.: "Neff Juggler and SoftGenLock: Running VR Juggler with Active Stereo and Multiple Displays on a Commodity Computer Cluster", IEEE Virtual Reality Conference 2002, VR'02, Orlando, Fla., USA, 24-28 Mar. 2002.
However, one disadvantage with the above-described known image processing devices is the unsatisfactory image quality when a plurality of unsynchronized image input signals are combined with one another and then geometrically distorted or rectified.
The task of the invention is therefore to provide an image processing device and an associated operating method which gives an improved image quality when combining a plurality of image input signals and carrying out geometric distortion or rectification.
This task is solved by the features of the invention.

Image processing device and associated operating method

Max-Planck-Gesellschaft zur Foerderung der Wissenschaften e.V.


In a method for operating an automation system having a first central unit and a second central unit connected with one another for communication and several automation devices connected for communication to the second central unit, information relating to a plurality of communication channels arranged between the second central unit and a respective automation device is compiled in a communication data record, and information relating to communication relationships with the plurality of communication channels and the respective automation device that can be accessed via the plurality of communication channels is automatically transmitted to the first central unit, based on a communication data record.

The present invention relates to a method for operating an automation system, in particular a distributed automation system.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
The term "automation device" includes all devices, facilities or systems, in other words in addition for instance to controllers, such as programmable logic controllers, process computers, (industrial) computers, decentralized peripherals, operating and observation devices and suchlike also drive or other aggregate controllers, frequency converters and similar, as are or can be used to control, regulate and/or monitor technological processes, for instance for shaping or transporting material, energy or information etc., wherein energy is expended or converted in particular by way of suitable technical facilities, like for instance sensors or actuators.
In an automation solution having a central unit and several automation devices connected thereto for communication purposes, depending on the type and number of connected automation devices, a significant complexity of the resulting automation system is produced. This complexity increases again when different types of connection, in other words different communication media and/or different communication protocols are used to connect the automation devices. By way of example, reference is made here to a situation in which the respective automation devices are connected to three different networks, e.g. Profibus, Profibus Integrated and Profinet etc.
The aforementioned complexity increases again when an additional central unit (first central unit), which is to access the automation devices connected to the other central unit (second central unit), is connected to the central unit mentioned by way of example for communication purposes. Project planning of the communication relationships and communication paths/transport channels/communication channels, subsequently referred to in summary as communication channel, must then take place between the second central unit and at least the automation devices relevant to the first central unit and also to the first central unit, so that the effort involved in the project planning of the second central unit is repeated or at least essentially repeated for the first central unit. In addition, repetition of such project planning is prone to error and any errors which might occur in such cases can only be found with difficulty.
It would therefore be desirable and advantageous to obviate prior art shortcomings and to provide an improved method for operating an automation system having at least two central units and a plurality of automation devices connected to the second central unit, in which the aforementioned disadvantages are eliminated, or their adverse effects are at least reduced.

Method for operating an automation system


A reconfigurable image suppressing receiver includes a front-end amplifier, a first multi-mode circuit, a second multi-mode circuit, a wideband combining transformer, and a controller. The front-end amplifier is configured to receive a radio frequency (RF) signal from an antenna and adjust a gain of the RF signal. The first multi-mode circuit is configured to mix a first instance of the RF signal with an in-phase local oscillator signal to generate an in-phase intermediate frequency (IF) signal. The second multi-mode circuit is configured to mix a second instance of the RF signal with a quadrature local oscillator signal to generate a quadrature IF signal. The wideband combining transformer is configured to combine the in-phase IF signal and the quadrature IF signal to generate a combined IF signal. The controller is configured to adjust one or more tunable parameters associated with the combined IF signal.

As a result of RF mixing, a signal and its image may be simultaneously detected by a receiver. Consequently, a receiver with poor image rejection may suffer from higher levels of interference than one with better image rejection. Thus, there is a need for high performance image rejection capability in radio receivers that are used for sensitive communications applications (e.g., for aircraft-to-aircraft, aircraft-to-ground, and/or critical mission communications).

Reconfigurable wideband image suppressing receiver