A drive system and a method of operating such a system are specified. The drive system comprises at least two drive groups having a plurality of drive controllers of controlled drives. The drive controllers of a drive group are synchronized via a drive bus by means of a local synchronization clock, and the local synchronization clocks are made equal to a global synchronization clock via a drive data network connecting the drive control means. The plant-wide synchronization of the drives via a global signal enables a drive system to be equipped with a virtually arbitrary number of drives. As a result of the fact that the desired values are preferably likewise transmitted synchronously, based on the global synchronization clock, between the drive control means via the drive data network, it is also the case that no time errors occur during the desired value transmission. The invention is preferably used for rotary printing machines.

1 . Field of the Invention
The invention relates to electric drive technology. It is based on a method of operating a drive system. Furthermore, the invention relates to a device for carrying out the method.
The fields of application of the invention are, for example, machine tools and rotary printing machines. A preferred application is rotary printing machines for printing newspapers, having a large number of individually driven printing cylinders and having flexible production capabilities.
2. Discussion of Background
A method and a device of the generic type is known from the text of the paper presented at the "Ifra" seminar, May 21 and 22, 1996, by Juha Kankainen, Honeywell Oy, Varkaus, Finland. Presented there is a shaftless drive system in which a plurality of drive groups are provided, each drive group comprising a drive control means and at least one drive. For its part, the drive comprises a drive controller and at least one motor. The drive controllers are connected to one another via a drive bus (in the document mentioned, designated "vertical SERCOS ring"). The drive control means (designated "process station") are connected via a dedicated drive data network in the form of a ring. The drive control means are connected to higher-order control units. According to the SERCOS standard, the drives are synchronized via a local synchronization clock.
A further concept for a shaftless drive system in the form of a rotary printing machine is disclosed by German Laid-Open Specification DE 42 14 394 A1. The rotary printing machine disclosed in this document constitutes a drive system which comprises at least two drive groups in the form of individually driven printing point groups. The drive groups have a drive control means and at least one drive, which is composed of a motor and a drive controller. The drive groups receive their position reference (master shaft) directly from the folding apparatus. The drive controllers of the drive groups are likewise connected via a drive bus. The drive control means are connected to one another via a data bus and to an operating and data processing unit. The predefinition of desired values and the administration of the printing point groups is carried out via this data bus.
The drive controllers of such a drive system enable torque control, speed control (rotational speed control) or position control (angular position control) of the driven shaft. In the case of high requirements for angular synchronism, such as there are, for example, in drive systems in machine tools and in printing machines, position controllers (angular position controllers) are preferably used.
The digital drive controllers are preferably equipped with fast digital signal processors. Such fast digital drive controllers can execute one control cycle, in the case of position control, in a very short computing time, preferably in 250 .mu.s or in a shorter cycle time.
In such drive systems, three-phase motors are preferably used. The electric drive power is supplied to the individual motor via a power electronic circuit, preferably having a frequency converter function. The power electronic circuit is driven by the digital drive controller.
The individual drives are equipped with highly accurate actual value transmitters, preferably optoelectronic position transmitters. The signal resolutions of such known, highly accurate actual value transmitters lie in the range of over 1,000,000 points per revolution (360.degree.). The practically useful measurement accuracies of the known actual value transmitters lie in the range of more than 100,000 points per revolution (360.degree.).
The actual value transmitter for the individual drive is often fitted to the motor shaft. However, arrangements are also known in which an actual value transmitter is fitted to the load driven by the motor. For example, in the case of printing machines it is advantageous to fit a high-resolution position transmitter at the torque-free end of the driven printing cylinder.
The decisive factor for high-precision synchronism of a plurality of position-controlled individual drives is the accurate synchronization of the drives via a common clock, and the cyclic supply thereto of position desired values in the predefined clock frame.
The common clock ensures that the individual drive controllers execute their position control functions exactly synchronously in time (at the same time) and in so doing evaluate the predefined position desired values in a time-consistent manner (at the same time).
Drive systems are known in which a number of individual drives are supplied with a common synchronization clock and with desired value data from a central drive control means via a fast drive bus.
The data transfer is preferably carried out according to the stipulations of the SERCOS standard. The SERCOS standard is a data interface agreed by several drive manufacturers, which supports the synchronization and the desired value transmission for the drives of a drive group.
With reference to the SERCOS standard, see: "Kurzubersicht der Produkte mit SERCOS-Interface" [Brief overview of products with a SERCOS interface], 2nd edition, October 1995, Fordergemeinschaft SERCOS interface e.V., Im Muhlefeld 28, D-53123 Bonn; or "SERCOS interface, Digitale Schnittstelle zur Kommunikation zwischen Steuerungen und Antrieben in numerisch gesteuerten Maschinen" [SERCOS interface, digital interface for communication between control means and drives in numerically controlled machines], Update 9/91, Fordergemeinschaft SERCOS interface e.V., Pelzstrasse 5, D-5305 Alfter/Bonn.
In this case, the drive bus is preferably implemented as a ring-like glass fiber connection. The data transmission is in this case controlled and coordinated by a central main station (bus master). The individual drives, connected to the ring-like data line, are substations, that is to say slaves, in the data transmission. The individual drives receive a common synchronization clock and their desired value data from the central drive control means via the drive bus. The central drive control means generates the common synchronization clock and calculates the desired values for the individual drives of the drive group. The drive control means in this case supplies, in short cycle times, in each case new desired values for the individual drive controllers. Preferred cycle times for the transmission of the common synchronization clock and for the calculation and the transmission of the desired values of the individual drives of a drive group are 62 .mu.s, 125 .mu.s, 250 .mu.s, 500 .mu.s, 1 ms, 2 ms, 3 ms, . . . 63 ms, 64 ms or 65 ms in the SERCOS standard.
Using drive systems of this type, quite high synchronization accuracies can be implemented between the drives of a drive group. Mechanical synchronization shafts and mechanical gear transmissions can be replaced by electronically synchronized groups of individual drives. Drive systems of this type, with electronic synchronization of the individual drives, thus enable electronic synchronization shafts and electronic gear transmission functions.
Using drive systems of this type; it is possible, for example, for rotary printing machines with individually driven printing cylinders to be implemented--without mechanical synchronization shafts (see, for example, the Laid-Open Specification mentioned at the beginning and the text of the paper).
Rotary printing machines for multicolor printing, having individually driven printing cylinders, place particularly high requirements on the angular synchronism of the individual drives. In the case of four-color printing, synchronization accuracies of the individual printing cylinders of the order of magnitude of 10 .mu.m are often required. In the case of a printing cylinder periphery of, for example, 1 m this means that a position measurement and position control with an accuracy of better than 100,000 points per cylinder revolution (360.degree.) must be carried out. In the case of printing speeds (paper web speeds) of more than 10 m/s, this moreover means that the time synchronization error between the individual drives of the cylinders printing on one paper web (according to the formula time=distance/speed=10 .mu.m/10 m/s=1 .mu.s) must be smaller than 1 .mu.s.
This means that the individual drive controllers, during their position control, have to be synchronized via the drive bus with a time accuracy of better than 1 .mu.s.
Using the drive systems cited and the synchronization and the supply of desired values to the individual drives via a ring-like glass fiber connection, according to the SERCOS interface agreements, these requirements can be achieved only for drive groups having a limited number of individual drives.
As a result of the central common devices, drive control means and drive bus, there are specific bottlenecks and disadvantages, however, which have an increasingly negative effect with an increasing number of drives in the drive group. The most important limitations and disadvantages are the following:
With an increasing number of drives, as a rule the synchronization error of the data line increases. In the case of a ring-like glass fiber connection with data transmission functions, for example in accordance with the SERCOS interface agreements, the following is true for the growth of the synchronization error: In the case of each drive controller which is connected to the glass fiber ring, a time-discrete signal sampling is carried out at a specific sampling period, for example 30 ns. The binary signal reproduced in the receiver as a result of time-discrete sampling can thus jitter at most by the sampling period, for example 30 ns (on the time axis, with respect to the original signal in the transmitter). Thus, in each participant, that is to say drive, there is a time-sampling error which makes itself noticeable as jitter (time jitter) This sampling error (jitter) also refers to the common synchronization clock. The sampling error therefore manifests itself as a synchronization error. The sampled signal is used in the individual drive and--following appropriate regeneration of the signal--is also forwarded to the respective next drive controller in the glass fiber ring. Depending on the number of drives in the glass fiber ring, the synchronization errors (jitter) of the individual participants add up to an overall error. As an example, in the case of 33 drives in the glass fiber ring, each having a 30 ns sampling error, this results in an overall synchronization error of about 1 .mu.s.
With an increasing number of drives in the ring, the cycle time needed for the data transmission also increases. If, for example, a data transmission time of 250 .mu.s is needed per drive, then in the case of the connection of 32 drives to a ring, this means that the cycle time for the data transmission must be at least 8 ms. A rise in the cycle time for the transmission cycles also means longer time intervals between the individual synchronization clocks--in the example cited this is 8 ms. Between successive synchronization clocks of the ring, the local clock generators of the individual drives run freely--and wander (drift) more or less from one another, depending on the inaccuracy of the crystals used.
If the local clock generator of a drive is, for example, equipped with a crystal of a quality of 100 ppm (parts per million), then this clock generator may have a time deviation of (plus or minus) 0.8 .mu.s after 8 ms, because of its inaccuracy. The time deviation between two arbitrary drives, which is caused by the inaccuracy of the two local clock generators, is the sum of the inaccuracies of the two clock generators, for example (2*0.8 .mu.s)=1.6 .mu.s.
The wandering off (drifting) of the local clock generators of the individual drives between 2 successive synchronization clocks of the ring manifests itself as an additional synchronization error, since the individual drive controllers execute several control cycles during one data transmission cycle, of for example 8 ms.
In the case of a control cycle in the drive of, for example, 250 .mu.s and a data transmission cycle of, for example, 8 ms on the ring, the drive executes 32 control processes during one data transmission cycle. Only the first control process is in this case strictly synchronized with the synchronization clock of the ring. In the case of the following 31 interpolating control processes, the time control is carried out via the local clock generator of the drive. The inaccuracy of the local clock generators of the individual drives manifests itself as additional synchronization errors in the interpolating control processes.
With an increasing number of drives in the ring, the cycle time of the data transmission therefore increases, and hence the time interval of successive synchronization clocks, and with an increasing time interval between successive synchronization clocks, the wandering apart (drifting) of the local clock generators (crystals) of the individual--drives increases. Hence the synchronization error increases and the precision of the position control no longer achieves the required values.
The drive controllers connected to a fast drive bus obtain not only the common synchronization clock, but also the desired value data from the central drive control means, which is also the master during the data transmission. With an increasing number of drives, the time needed for the desired value calculations and desired value transmissions increases. With an increasing number of drives, the loading of the central drive control means increases as a result of the cyclic desired value calculations. The central drive means supplies the connected drives cyclically with new individual desired values and with a common synchronization clock. The cycle times for the desired value calculations and the common synchronization clock are preferably of the order of magnitude of 1 ms.
With an increasing number of connected drives, the time expenditure for the desired value calculations in the central drive control means increases. For example, given a computing time of 250 .mu.s for the desired values of one drive, and given 32 connected drives, the cycle time of the desired value calculations in the drive control means must be at least 8 ms. This constitutes an enormous computing load on the central drive control means which, for its part, once more limits the number of connected drives.
With an increasing number of drives, the effects of an individual error in the central drive control means or in the drive bus increase.
The ring-like glass fiber connection according to the SERCOS standard is not redundantly designed, and the drive control means, which is simultaneously the master in the data transmission, is also not redundantly designed. In the case of an error in the central drive control means, or in the case of an error in the drive bus, all the connected drives thus fail.
In industrial production plants it is often required to limit the effects of individual errors to a closely limited environment. An individual error in the electronics may lead to the failure of a specific functional unit but in no way to the failure of an entire production plant.
In printing machine construction, it is for example largely tolerated that an individual error in the drive electronics leads to the failure of one functional unit, for example of one printing unit having 8 printing cylinders. It is not tolerable for an error in the drive control means or in the drive bus to lead to the failure of an entire production plant, for example of an entire newspaper printing plant.
The number of drives to be connected to a drive control means and a drive bus should therefore preferably be limited to a specific number on availability grounds, so that failure of the drive bus or of the drive control means has effects only on one individual functional unit of an industrial plant, for example on one printing unit of a newspaper printing plant.
A centralized drive system having a central drive control means and a drive bus, to which all the drives to be operated in precise synchronism are connected, often does not correspond to the natural structure, functional distribution and module formation in large technical plants.
Industrial plants often comprise several self-contained functional units, which in each case contain all the associated mechanical and electrical functions.
Control systems and drive systems are therefore preferably structured, associated and distributed in accordance with the functional units of the industrial plant. This results in self-contained functional units which can be tested and commissioned simply and independently of one another. The interfaces between functional units which are delimited in this way are simple and comprehensible.
The advantages of a decentralized, distributed structure--capable of being adapted to the technical plant--of the control and of the drive system result in particular from the clearer system structure, simpler comprehensibility, better testability, closely delimited error effects. These advantages often lead to lower production costs, operating costs and maintenance costs.
In the case of newspaper printing presses, for example, the printing units, folding apparatus and reel carriers are preferably designed as self-contained functional units and are in each case equipped with dedicated, local control means and dedicated, local drive systems.
A centralized drive system having a central drive control means is a great obstacle to the implementation of technical plants having self-contained functional units and simple, clear interfaces.
The significant disadvantage of a central drive control means is that all the desired value data has to be led to the individual drives via the central drive control means. It is not possible for the local control means of a functional unit to communicate directly with the local drive control means of the functional unit, since there are no decentralized, local drive control means of functional units.

Method of operating a drive system and device for carrying out the method


A resistance memory element includes an elementary body and opposing electrodes separated by at least a portion of the elementary body. The elementary body is preferably made of a strontium titanate-based semiconductor ceramic expressed by the formula: (Sr1−xAx)v(Ti1−yBy)wO3 (where A represents at least one element selected from the group consisting of Y and rare earth elements, and B represents at least one of Nb and Ta), and satisfies the relationships 0.001≦x+y≦0.02 (where 0≦x≦0.02 and 0≦y≦0.02) and 0.87≦v/W≦1.030. This semiconductor ceramic changes the switching voltage depending on, for example, the number of grain boundaries in the portion between the opposing electrodes.

1. Field of the Invention
The present invention relates to resistance memory elements, and particularly, to a resistance memory element including an elementary body made of a polycrystalline semiconductor ceramic.
2. Description of the Related Art
A resistance memory element includes an elementary body that can memorize resistance. This elementary body originally has, for example, a relatively high resistance. However, when at least a predetermined voltage is applied to the elementary body, the resistance is reduced and a low resistance state is maintained or memorized even after the applied voltage is removed. In contrast, when at least the predetermined voltage is applied in the opposite direction to the elementary body in a low resistance state, the resistance is increased and a high resistance state is maintained or memorized even after the voltage is removed.
Such a resistance memory element can switch between a high resistance state and a low resistance state by applying a voltage equal to or greater than a threshold in a positive direction or the opposite direction, and thus, can change and memorize the resistance. Such resistive switching enables the resistance memory element to function not only as a memory element, but also as a switching element.
A known resistance memory element is described in, for example, T. Fujii et al., "Hysteretic Current-Voltage Characteristics and Resistance Switching At An Epitaxial Oxide Schottky Junction SrRuO3/SrTi0.99Nb0.01O3", APPLIED PHYSICS LETTERS 86, 012107 (2005). In a resistance memory element described in this published article, an interface between different types of material, more specifically, the bonded interface between a monocrystalline substrate and a SrRuO3 thin film (monocrystalline thin film), is capable of memorizing resistances. This resistance memory element has a switching voltage not greater than about 3 V, and accordingly, switches at a relatively low voltage. The switching voltage refers to a voltage at which the resistance state is changed.
Many of the circuits in which a resistance memory element may be used are operated at a rated voltage of greater than about 3 V. When a resistance memory element as described in the above published article is used as a switching element with a relatively high driving voltage, the switching voltage must be greater than the rated voltage.
However, since the switching voltage of the resistance memory element of the above published article is not greater than about 3 V, the element may switch at the driving voltage. Thus, this element cannot be used as a switching element with a relatively high driving voltage.
If a switching element that switches at a voltage of, for example, at least about 30 V is produced, another resistor must be provided in series. In this instance, the switching voltage can be set to a relatively high voltage, but the power consumption is increased due to the additional resistor. In addition, the resistor disadvantageously reduces the variation of resistances switched.
Varistors are also relevant to the present invention. For example, Japanese Patent No. 2727626 discloses a multilayer varistor including a SrTiO3 elementary body including various elements and internal electrodes made primarily of Pd in the elementary body. In order to produce such a varistor, an element that functions as an acceptor is actively diffused or added and re-oxidation is performed to form a grain boundary barrier after a reduction treatment for forming semiconductor. When at least a predetermined voltage is applied to the varistor, the varistor changes into a low resistance state, but the state is not maintained or memorized and is returned to the initial state after the applied voltage is removed. Thus, the varistor is not a resistance memory element.


A semiconductor integrated circuit comprises a plurality of combinational logic components, a memory and a testing arrangement for configuring the memory prior to testing the combinational logic components using one or more scan chains. The arrangement includes a bit pattern generator for generating a predetermined bit pattern for writing to the memory, a switching arrangement for selectively switching the memory input to receive data from the combinational logic components or from the data generator. The switching arrangement and data generator are arranged to input the predetermined bit pattern to the memory prior to testing the integrated circuit.

1. Field of the Invention
The present invention relates to a full scan arrangement for testing digital circuits, in particular testing using scan chains with memory circuits.
2. Description of the Related Art
The testing of digital circuits using scan chains is well-known to those skilled in the art. In brief, a scan chain is a series of linked flip-flops which are arranged through areas of combinatorial logic on an integrated digital circuit. Each flip-flop receives an input from the previous flip-flop in the chain, and from the combinatorial logic through which the chain passes. At an input pin, a test pattern of logic 1's and 0's is input to the scan chain, and passes through the sequence of flip-flops and combinatorial logic to an output pin. The output sequence of logic 1's and 0's is changed from the input sequence by operation of the logic under test. The manner in which the sequence is changed is not important to determining whether the circuit is functioning correctly. The circuit can be determined to pass or fail the test by simply comparing the output sequence with the output sequence of a correctly functioning circuit.
To facilitate scanning, it is known to use software for automatic generation of the test sequences of logic 1's and 0's, known as test patterns, and to perform analysis. Such tools are known as Automatic Test Pattern Generation (ATPG) tools and are integral to full scan testing. A known example is Tetramax™ of Synopsys, Inc. Whilst this tool facilitates testing, on large chips the testing task is significant. On recent graphics chips designs there can be 170 scan chains with 2,600 flip-flops each. This results in excessive vector count and/or low test coverage.
We have appreciated the difficulty in testing integrated semiconductor circuits which contain one or more memory components.


This invention provides a data record/playback device that retrieves stored data by specifying user-input data, and makes the retrieving easier. The data record/playback device, having: user input unit for receiving user input from a user; user input detector for detecting the user input through the user input unit; consecutive data input unit for receiving consecutive data including at least one of audio data and image data; consecutive data storage for storing consecutive data received by the consecutive data input unit; state detector for detecting a state that includes at least one of circumstantial information and eventual information about a moment when the user input detector detects the user input; association data storage for storing association data that includes the user input detected by the user input detector, the state detected by the state detector, and the storage position where the consecutive data is stored in association with each other; and display unit for displaying the user input detected by the user input detector and the state detected by the state detector in association with each other in accordance with the association data stored in the association storage.

1. Field of Invention
This invention relates to a data display device that displays user input data and a data record/playback device that stores multimedia data with user input data and plays back or displays the stored user input data and the multimedia data in association with each other.
2. Description of Related Art
For recording important points of meetings, lectures, interviews, conversations using telephones or videophones, video image, and the like, a recordist commonly records them. For example, in a meeting, one of the participants of the meeting works as a recordist to record every statement from all participants or to record important items. However, since contents of a meeting or details of the story is not recollected from a note written in the meeting or the speaker name of a statement is not recorded, it is often difficult to make minutes after the meeting.
Conventionally, there have been proposed devices that use digital disks, digital still cameras, videotapes, semiconductor memory, and the like to store and playback data such as meetings, lectures, interviews, conversations using telephones, and videophones, as well as video images, images from monitoring cameras, and the like. Compared to having a reporter manually write down only the important points of the information to be recorded, the use of such data storage devices has the advantage of allowing voices and images to be recorded completely without omissions.
These devices can involve: recording digital signals sent via a computer network onto a storage medium; recording analog input signals from an video camera or a microphone directly to a storage medium; or encoding and converting such analog signals into digital signals.
However, when the method that records the whole meeting has no function to retrieve the recorded data, all contents of the recorded data should be played back to make minutes, that is, summarized contents of the meeting. Thus, it takes extremely long time to make minutes. In addition, these devices had a problem in that desired sections from the recorded voices or images could not be quickly searched.
To overcome this problem, tape recorders and videotape recorders have been proposed that allow easy searching of important sections by adding check-marks to important sections in the incoming audio signals or incoming image signals.
However, these check-marks only serve to specify the position of important sections. It is not possible to indicate which section of the audio signal or the image signal corresponds to each check-mark. Thus, all the audio or image signals that have been check-marked must be played back to determine the contents. Furthermore, it is also necessary to perform the awkward operation of pressing a button while someone is talking, thus distracting the user from the statement taking place.
For these reasons, there have been proposed devices in which audio signals or image signals that are input continuously are stored and played back so that they are associated with user-input data that has been entered via a pen or a keyboard by the user at selected points in time. By using such devices, the audio signal or the image signal can be recorded while the person making the recording performs pen or keyboard input in the same way that a reporter would take notes. By referring to the entered notes later, the portions of the audio or image signal to be played back can be easily selected and played back.
As this kind of art, for example, Japanese laid-open publication No. 7-226931 discloses a device that make a minutes creation work after the meeting effective by storing multimedia data entered by a meeting attendee in association with text data inputted by an recordist. By using this device, when one of the pieces of text data is selected after the meeting, the multimedia data associated with the selected text data can be easily retrieved. Thus, circumstances of the meeting can be reproduced from the meeting note written by the recordist.
For example, in Japanese laid-open publication number 7-182365, Japanese laid-open publication number 6-176171, Japanese laid-open publication number 6-343146, ACM CHI '94 Proceedings pgs. 58-64 ("Marquee: A Tool for Real-Time Video Logging") the subject matter of which are incorporated herein by reference, there are proposed devices wherein user-input data is associated with audio signals or image signals by using a time stamp. When the data is to be played back, a piece of user-input data displayed on a screen can be specified, and the audio signals or image signals recorded at the same time as the specified user-input data was recorded, can be played back.
In Japanese laid-open publication number 6-205151, the subject matter of which is incorporated herein by reference, there is disclosed a device that records audio signals or image signals while adding an index whenever user input has been interrupted for a fixed period of time. When playback is to be performed, user-input data displayed on a screen can be specified, and the audio signals or image signals from the index section corresponding to the specified user-input data is played back.
Further, Japanese laid-open publication number 7-110822 discloses a hypermedia device in which input data from the user and audio or image signals are associated with each other, and then are entered into the computer. Thus, this hypermedia device automatically creates a link between the user-input data and audio or image signals.
By using the devices disclosed in the aforementioned Japanese laid-open publication number 7-182365, 6-176171, 6-343146, 6-205151, 7-110822, and ACM CHI'94 Proceedings pgs. 58-64, the recordist can input data by using a pen or keyboard as if he wrote a note, and audio or image data are recorded. Thus, by referring to the inputted note (user-input data) later, a portion of the audio or image signals, which is desired to play back, can be easily selected and played back. This makes the creation of minutes efficient.
However, those conventional arts described above display only user-input data, such as pen data or a string entered from a keyboard, on the display screen. Data referring to the circumstances when the user-input data is entered is not displayed.
When minutes are created by selecting important points of a meeting from the recorded multimedia data and user-input data, and then editing them, if retrieval in the editing work can be performed easily and certainly by using only data displayed on a screen, retrieving work becomes much easier.
In the conventional arts described above, user-input data are displayed on a screen. When one of the displayed user-input data is specified, audio data or image data corresponding to the specified user-input data can be retrieved.
However, all the user-input data do not have the same priority. Also all the multimedia data that is recorded corresponding to the user-input data does not have the same priority. In addition, the priority of the multimedia data changes according to search condition during the editing.
Thus, the conventional arts described above simply display user-input data as a cue of retrieving. Therefore, it is difficult to know the priority or meaning of the user-input data from the display of the user-input data. Further, there is no cue to know the contents of the multimedia data that is stored corresponding to the user-input data.
Thus, in the retrieving of the conventional arts described above, the priority or meaning of each piece of the audio data or image data corresponding to each of the user-input data cannot be specified, unless audio data or image data corresponding to all the user-input data are played back. In other words, in the conventional art described above, a cue to retrieve audio data or image data is only the user-input data displayed on a screen. The user-input data is sometimes insufficient to retrieve a required audio or image data.
For example, when comments from a particular speaker is required to be played back, it is impossible to know which user-input data was recorded for a statement of the speaker, unless the user intentionally recorded the speaker who speaks at the point in time of user input. Thus, portions of audio data and portions of image data corresponding to user input data should be played back one after another, and their contents should be examined, in order to retrieve comments from the speaker.
Japanese Patent Laid-Open Hei.7-226931 described above disclose a method to store text data inputted by the user associated with the data identifying the speaker who speaks when the text is inputted. But the association therebetween is not displayed on the screen. Thus, the association between the user-input data and the comment of the speaker cannot be used during retrieving operation.
Japanese Patent Laid-Open Hei.7-182365 discloses a method for creating a series of image frames for each speaker, and a method for displaying a history of the time points of change of speakers and the speakers on the time axis. However, in the art disclosed by Japanese Patent Laid-Open Hei.7-182365, since these data are not displayed in association with user-input data, data that shows the association between the user-input data and the comment of speaker cannot be referred at the time of retrieving operation.
In addition, Japanese Patent Laid-Open Hei.7-182365 discloses a method for displaying a history of all time points of changes of speakers and the speakers on a screen. However, in a device that retrieves audio or image data by using user-input data as a cue, it is redundant to display a history of all time points of change of speakers. Since it makes display on a screen rather complicated, retrieving operation becomes difficult.

Data display device and data record/playback device displaying consecutive data and user input in association with each other


A system for the automated dilution and delivery of mixtures of diluent and liquid samples to a particle counter comprises a container positioning member for receiving and retaining congruent sample containers with a volume of liquid sample therein. An automated diluent pumping mechanism draws a respective volume of a diluent from a diluent source and introduces the diluent into the each sample container for mixing with the unknown volume of liquid sample within each sample container to together form a mixture that is substantially equal to a pre-determined threshold volume. A mixer agitates the mixture in the sample containers. An automated mixture pumping mechanism sequentially draws a respective volume of mixture from the sample containers and delivers the drawn volume of the mixture to the optical particle counter for testing.

It is common to quantitatively measure the size and concentration of particulate contaminates in liquids, such as new and used oils, in order to determine various characteristics of the liquids. In samples of used oil, for instance, there are both "hard particles" that are targeted for measurement in terms of size and concentration, and similarly-sized "soft particles" that inhibit the accurate measurement of the hard particles. The presence of soft particles in a liquid sample is known to significantly elevate particle counts to the point where their presence compromises the validity of the count data obtained. It has been found, however, that the addition of a suitable diluent to oil samples, can substantially eliminate the interference of soft practices in obtaining accurate hard particle count data.
Hard particles in oil include without limitation, dirt and metal fragments, which have a serious impact on the life of equipment by accelerating wear and erosion. Such hard particles originate from a variety of sources, including generation from within an operating fluid system, ingress into the operating fluid system, or contamination that may occur during the storage and handling of new oils. Typically, "soft particles" include certain additives or additive by-products that are semi-insoluble or insoluble in oil, and other similar materials that are not known to directly increase wear and erosion within an operating system, such as, for example, air bubbles and water bubbles.
The measurement of such contaminants is particularly important in order to identify the potential problems with samples of new or used oils, to determine the characteristics of various types of new or used oils, and also to determine whether engines and/or machinery are introducing metal particles into used oil. More particularly, particle count results can be used to aid in assessing the capability of the filtration system responsible for cleaning oil or other fluid, determining if off-line recirculating filtration is needed to clean up the fluid system, or aiding in the decision of whether or not a fluid change is required. An abnormal particle count may trigger concerns of these possibilities, which can be confirmed by additional testing.
Fundamentally, in order to permit the calculation of useful and relevant data related to particles found in fluids, such as oil, the quantity of various sizes of contaminants needs to be determined. It is well known that in order to be useful, such measurement requires quantitative guidelines in order to meaningfully present the results. Accordingly, various standards are used for testing and reporting fluid cleanliness. Two such standards include the SAE Aerospace Standard (AS) and the ISO Code System. It has been found useful to group particle sizes into coded ranges in order to permit ready handling and manipulation of the data. The following table illustrates one such standard of measurement as per the SAE Aerospace Standard (AS) system, with the codes for each range given in the left-most column.
Cleanliness Classes for DifferentialParticle Counts (particles/100 ml)Size6 μm (c)14 μm(c)21 μm(c)38 μm(c)totototoCode14 μm(c)21 μm(c)38 μm(c)70 μm(c)>70 μm(c)0012622410025044820150089163121000178326132000356631124400071212622458000142525345861600028505069016732000570010121803286400011400202536064912800022800405072012810256000456008100144025611512000912001620028805121210240001824003240057601024
It is well known to use automated optical particle counters to quantitatively measure the size and concentration of particulate contaminants in samples of fluids, such as new and used oil. Commonly, such optical particle counters perform analysis based on the light extinction principle, using a laser beam passing through a liquid sample. Such optical particle counters are capable of recording the size and number of particles as they pass across a detector, and such equipment typically includes a sampling apparatus that automatically delivers a pre-determined volume of liquid specimen at a controlled flow rate to the optical sensing cell of the optical particle counter. Examples of prior art optical particle counters are taught in, amongst others, U.S. Pat. No. 5,426,501 (Hokanson et al.) issued Jun. 20, 1995, and U.S. Pat. No. 5,172,004 (Furuya) issued Dec. 15, 1992. Indeed, tests performed by such automated optical particle counters are considered by many to be the single most important test for oil analysis.
There are various well-known problems associated with the use of optical particle counters to test liquid samples, especially samples of oil. One of the two most fundamental problems is that of particle co-incidence. Particle co-incidence occurs when more than one particle is present in the optical sensing cell of the optical particle counter at the same time and a "large" particle is falsely detected rather than two (or more) smaller ones. It is well known that particle co-incidence causes inaccurate counting of the "hard particles" due to the presence of other type of particles, such as the "soft particles" in the liquid sample. Soft particles cause false high counts of particles in their size category, thus yielding false counts and an over-estimation of contamination levels across all sizes. Dilution of samples with a suitable diluent can reduce the probability of particle co-incidence.
Particle co-incidence can also occur due to the existence of air bubbles in the oil, thereby causing false positive readings. Bubbles can be caused by overly vigorous mixing or agitation of a liquid sample, which mixing may be necessary as part of the test procedure. Further, suspended or free water in the oil will generally be counted as particles.
Another fundamental problem associated with the use of optical particle counters to test liquid samples is that of the proper flow of high viscosity liquid samples. The forces required in order to develop the necessary pressure to rapidly achieve the required flow rate of the liquid samples through the optical sensing cell becomes quite significant, and even prohibitive. For this reason, it is extremely difficult to properly and accurately test high viscosity liquid samples in an optical particle counter without sample dilution using a suitable diluent.
In spite of the above stated advantages of using diluted oil samples for testing with optical particle counters, the vast majority of such testing is still carried out on undiluted samples where the oil sample to be tested is taken directly from a sample bottle without dilution. In such cases, a mechanically controlled syringe is typically used to draw up a measured volume of the liquid sample and inject it directly into the inlet port of the optical sensing cell of the optical particle counter. Alternatively, a sampling tube connected to the optical sensing cell inlet is lowered into the sample bottle. Pressure is used to force the liquid sample through the optical sensing cell of the optical particle counter. Samples are typically processed one by one (i.e., not in a batch process), with the optical sensing cell and feeding tubes being cleaned with solvent between tested samples.
Where liquid sample to be tested by optical particle counting are to be diluted prior to such testing in the prior art, it is common to manually measure and mix known quantities of the liquid sample and of a suitable diluent prior to testing. More specifically, a laboratory pipette is often used to manually draw a quantity of liquid from each sample bottle, as measured against volume markings on the pipette, and to inject this drawn quantity of liquid sample from the pipette into a sample container. This process is then repeated by pipette for adding a measured volume of a suitable diluent to the sample container. The two volumes are then summed for purposes of use in any subsequent calculations required to convert raw particle counts taken from a sample into standardized volumetric particle counts.
Although manual pipetting is accurate, it has a number of significant drawbacks associated with it, particularly where carried out repetitively for a high number of liquid samples to be subsequently presented for testing by an optical particle counter. These problems include, without limitation: i) pipetting is labour intensive (i.e., time consuming) for the operator carrying out the procedure; ii) pipetting is tedious for the operator carrying out the procedure; iii) the preparation of test samples cannot be performed outside of normal laboratory operation hours without special (and typically more expensive) arrangements being made to staff the test facility with appropriate laboratory personnel; and, iv) operators carrying out the pipetting procedure for large numbers of test samples are susceptible to repetitive strain injuries.
In order to improve and standardize methods for optical particle counting utilizing diluted liquid samples, ASTM International of West Conshohocken, Pa., USA has developed and published a test protocol known as ASTM-D7647 and entitled "Test Method for Automatic Particle Counting of Lubricating and Hydraulic Fluids Using Dilution Techniques to Eliminate the Contribution of Water and Interfering Soft Particles by Light Extinction". ASTM-D7647 prescribes a standardized testing methodology that requires the use of a diluent to dilute the original samples to specified ratios of oil to diluent, prior to optical particle counting readings taking place. It has been found that the ASTM-D7647 test protocol notably addresses the particle count inaccuracy issues caused by particle coincidence and soft particles (as discussed above), especially where high viscosity liquids are being tested. Accordingly, the erroneous contribution of soft particles to the particle size cumulative count is substantially negated by the ASTM-D7647 methodology. The quality of particle count data is significantly improved on many samples as the effects of known interference are removed. The present invention discloses and claims, in its simplest non-limiting terms, a system for the automatic dilution and delivery of a plurality of liquid test samples to an optical particle counter for batch testing of diluted liquid samples according to ASTM-D7647 in a more accurate and efficient manner than has been possible with prior art sample handling equipment and methodologies.
In spite of the fact that ASTM-D7647 test protocol provides significantly more accurate automated optical particle counts than earlier testing methods, it has not gained widespread commercial acceptance. This lack of widespread commercial acceptance is thought in large part to stem from the fact that while the injection of the test sample into the optical sensing cell and the reading of particle counts by the optical sensing cell may be substantially automated through the use of existing equipment, the preparation and presentation of the test samples, including the addition of the aforesaid diluent (by prior art manual pipetting techniques), has not been significantly automated to date, and remains extremely labour intensive. In other words, the testing of diluted oil samples using the ASTM-D7647 protocol is presently known to be used only with manual sample presentation procedures, which include pipetting, as aforesaid, with all of the attendant problems and difficulties previously mentioned. As such, while ASTM-D7647 is able to obtain improved particle count results over earlier testing methodologies which do not involve the addition of a diluent to the original sample volume to be tested, the prior art drawbacks associated with pipetting, represent an ongoing limitation to its widespread commercial acceptance, particularly in light of the fact that the number of pipetting operations per sample tested has necessarily been doubled over prior methodologies not utilizing sample dilution.
Apart from manual pipetting of samples and diluent as discussed above, there is presently no known apparatus, system, or method for reliably automating the dilution and delivery of liquid samples of oils and hydraulic fluids to an optical particle counter, in accordance with the ASTM-D7647 test protocol.
It is therefore an object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter in compliance with the ASTM-D7647 testing protocol.
It is a further object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter in a manner that eliminates the need for manual pipetting of the liquid samples or of any diluents added to such liquid samples before such testing.
It is a further object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, wherein presentation of such mixtures for automated testing is less labour-intensive than with known prior art equipment and methods used for this purpose.
It is yet another object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, wherein The system permits for much more prompt and uniform presentation of such mixtures for testing on a batch process basis.
It is still an object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, wherein The system precludes the operator performing the preparation of such mixtures from becoming unduly fatigued or from incurring repetitive strain injuries.
It is also an object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, wherein The system permits comparable testing accuracy to prior art manual dilution methods that use a pipette.
It is yet another object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, which apparatus permits an accurate automated determination of the volume of the liquid sample and of any diluent required to be added to said sample in order to provide for automated filling of each said test container to a standard test volume prior to commencement of said automated testing.
It is yet another object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, which apparatus permits automated dilution of the liquid samples to be tested, especially new and used oils, in the higher viscosity ranges.
It is yet another object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, the construction of which apparatus is relatively simple, compact, and economical.
It is yet another object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, which system saves the time and expense of manual sample presentation methods which make uses of pipetting, and which presents the mixtures in an ordered array, so as to allow automated testing of the presented liquid samples without the need for additional manual manipulation or supervision of the mixtures during said automated testing, thereby permitting such testing to run outside of normal laboratory operational hours.
It is yet another object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, which system maximizes the effective capacity of operators by freeing them from the need for manual pipetting of liquid samples.
It is yet another object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, which apparatus precludes operators from experiencing repetitive strain injuries by reason of the elimination of pipetting tasks associated with such presentation in the prior art.
It is yet another object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, which system permits the dilution and delivery of a plurality of mixtures of diluent and liquid samples contained in congruent sample containers to an optical particle counter, in accordance with the ASTM-D7647 test protocol.
It is yet another object of the present invention to provide an improved system for reliably automating the dilution and delivery of a plurality of mixtures of diluent and liquid samples respectively disposed in an equal plurality of congruent sample containers to an optical particle counter, which system facilitates and promotes the adoption of the ASTM-D7647 test method on a more widespread commercial scale.

System and method for automated dilution and delivery of liquid samples to an optical particle counter


A method for fabricating the control gate and floating gate of a flash memory cell. An active area is firstly formed on a semiconductor substrate, followed by the formation of a first insulating layer, a first conductive layer and a first masking layer. A first opening is then formed by partially removing the first masking layer, and a floating gate oxide layer is formed by oxidation. The remaining first masking layer is removed, followed by forming a sacrificial layer, which is then partially removed to define a second opening. The remaining sacrificial layer is used as a hard mask to partially remove the first conductive layer and the first insulating layer to form a third opening. A second insulating layer is formed to fill the third opening to form an insulating plug. Part of the first conductive layer and the first insulating layer are removed to form a floating gate, followed by forming a third insulating layer and a second conductive layer. The insulating plug is then used as stop layer to remove part of the second conductive layer and third insulating layer to form a control gate.

1. Field of the Invention
The present invention relates to a method for fabricating a flash memory cell. In particular, the invention involves the formation of control gate and floating gate of a flash memory cell.
2. Description of the Prior Art
Complementary metal oxide semiconductor (CMOS) memory is generally categorized into two groups: random access memory (RAM) and read only memory (ROM). RAM is a volatile memory, wherein the stored data disappears when power is off. On the contrary, turning off power does not affect the stored data in a ROM.
In the past few years, market share of ROM has been continuously expanding, and the type attracting the most attention has been flash memory. The fact that a single memory cell is electrically programmable and multiple memory cell blocks are electrically erasable allows flexible and convenient application that are superior to electrically programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM) and programmable read only memory (PROM). Furthermore, fabricating flash memory is cost effective. Having the above advantages, flash memory has been widely applied in consumer electronic products, such as digital cameras, digital video cameras, mobile phones, notebooks, personal stereos and personal digital assistant (PDA).
Since portability of these electrical consumer products is strongly prioritized by consumers, the size of the products must be minimal. As a result, capacity of flash memory must increase, and functions must be maximized while sizes thereof are continuously minimized. Having an increased amount of access data, capacity of memory cells has been enhanced from 4 to 256 MB, and even 1 G byte will become the market trend in the near future. Masks are essential in conventional processes for fabricating flash memory, even for the most critical process of floating gate and control gate.
Conventional process for a split gate flash memory cell is further explained with references to FIGS. 1Axcx9c1G. In FIG. 1A, a p-type silicon substrate 100 is thermal oxidized by local oxidation (LOCOS) to form a field isolation region (not shown). An active area is then formed by separating the field isolation region. Next, a first gate insulating layer 110 is formed on the surface of the substrate 100 within the active area using silicon oxide. Polysilicon is then formed by chemical vapor deposition on the first gate insulating layer 110, followed by doping with suitable dopants to form a first conductive layer 115. Then, a first masking layer 120 is formed using silicon nitride on the first conductive layer 115.
In FIG. 1B, photolithography and etching are performed to remove part of the first masking layer 120, thus defining a first opening 125 and exposing the first conductive layer 115. The remaining first masking layer is represented by 120xe2x80x2. Oxidation is then performed to transform the exposed first conductive layer 115 to an oxide, which is represented by a first insulating layer 130.
Next, in FIG. 1C, isotropic etching is carried out to remove the remaining first masking layer 120xe2x80x2.
The first insulating layer 130 is then used as hard mask to perform anisotropic etching, as shown in FIG. 1D, where part of the first conductive layer 115 and the first insulating layer 110 are removed. The first conductive layer 115 and the first insulating layer 110 underneath the first insulating layer 130 remain and the substrate 100 is exposed. The remaining first conductive layer 115 thus forms a floating gate 140, and the remaining first insulating layer 110 forms a first gate insulating layer 132.
Oxidation or chemical vapor deposition (CVD) is then carried out to form a silicon oxide as the second insulating layer 145, which covers the substrate 100 and surface of the first insulating layer 130 and sidewalls of the floating gate 140 and the first gate insulating layer 132, as shown in FIG. 1E.
Next, chemical vapor deposition is performed to deposit a layer of polysilicon as the conductive layer covering the second insulating layer 145. The conductive layer is then doped with dopant to become conductive, which is represented by the second conductive layer 150, as shown in FIG. 1F.
Photolithography and etching are then accomplished to remove part of the second conductive layer 150 and the second insulating layer 145. The remaining second conductive layer 150 is the control gate 170, and the remaining second insulating layer 145 forms the second gate insulating layer 175. The fabrication of control gate and floating gate are completed at this stage.
Due to the rapid advancement of the integration of memory, the sizes of all elements must be continuously decreased to achieve high integration. Conventional fabrication of flash memory relies upon masks for define sizes and positions of elements, but limitations of mask alignment. causes problems for finer line width, where alignments are difficult. Even tiny misalignment causes shorts for semiconductor elements. Consequently, devices cannot function properly as designed.
Fabrication of memory involves many steps, and production cycles usually last for weeks, even months. Electrical defects are usually not found until later stages. Therefore, when defects caused by misalignment are detected, a great quantity of partially completed products with defects are on the process line, which causes serious losses. Hence, it is the best to be able to handle defects in advance.
In order to overcome the above problems, the invention uses a self-alignment process to form an insulating plug between two floating gates, thus defining the position to form a control gate. This results in easy control of the process and sizes of the control gates and avoids the influence of line width. The length at the bottom of the control gate is consequently assured, which improves the conventional fabrication of flash memory. By having this insulating plug, disagreement among lengths of control gates caused by misalignment when forming control gates is avoided, thus the characteristics of flash memory are improved. The method provided in this invention is useful in fabricating highly-integrated flash memory, wherein defects caused by misalignment in conventional processes are avoided.
The present invention provides a method for fabricating control gate and floating gate of a memory cell, which comprises the following steps: providing a semiconductor substrate; forming a field insulating layer on the surface of the semiconductor substrate to define an active area; forming a first insulating layer on the substrate within the active area; forming a first conductive layer on the first insulating layer; forming a masking layer on the first conductive layer; removing part of the first masking layer to define a first opening and to expose the surface of the first conductive layer; forming a first gate insulating layer on the exposed surface of the first conductive layer by oxidation; removing part of the first masking layer to expose the surface of the first conductive layer; forming a sacrificial layer on the first conductive layer to cover the first gate insulating layer; removing the sacrificial layer between the neighboring first gate insulating layers within the active area to define a second opening and to expose surfaces of the first conductive layer and part of the first gate insulating layer; using the remaining sacrificial layer and the first gate insulating layer as a hard mask to remove the first conductive layer and the first insulating layer within the second opening to form another opening and to expose the surface of the substrate, wherein the opening together with the second opening form a third opening; forming a second insulating layer on surface of the remaining sacrificial layer to fill the third opening; using the remaining sacrificial layer as stop layer to remove the second insulating layer remains on the surface of the sacrificial layer without removing the part within the third opening, which forms an isolating plug; removing the remaining sacrificial layer to expose the remaining first conductive layer and a partial surface of the first gate insulating layer; using the first gate insulating layer and the insulating plug as a hard mask to remove the first conductive layer and the first insulating layer not covered by the first gate isolating layer and the isolating plug, wherein the remaining first conductive layer forms a floating gate and the remaining first insulating layer forms the second gate insulating layer; forming a third insulating layer on surface of the substrate to cover the surface of the first gate insulating layer, the surface and sidewalls of the insulating plug and the sidewalls of the floating gate and the second gate insulating layer; forming a second conductive layer on the surface of the third insulating layer; and using the isolating plug as stop layer to remove part of the second conductive layer and the third insulating layer to expose the the surface of the top part of the insulating plug and the surface of the substrate, wherein the remaining second conductive layer forms a control gate and the remaining third insulating layer forms a tunneling oxide.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings, given by way of illustration only and thus not intended to be limitative of the present invention.

Method for fabricating control gate and floating gate of a flash memory cell


A variable gain amplifying circuit, which applies a resistor ladder to obtain a more precise gain, is disclosed. The amplifying circuit includes an input, an operational amplifier (op-amp), a resistor unit and a feedback resistor. The feedback resistor is coupled between an output and an inverting input of the op-amp. The resistor unit includes at least one resistor ladder. The resistor unit further includes a switching unit for controlling whether the at least one resistor ladder is coupled between the input of the amplifying circuit and the inverting input of the op-amp. A differential amplifying circuit for more precise gain adjustment is also disclosed.

(a). Field of the Invention
The present invention relates in general to an electronic circuit, and more particularly to an amplifying circuit with a variable gain.
(b). Description of the Prior Arts
In modem circuit design, it is often necessary to provide the signal amplifying function with high accuracy. For example, in a common modulation mechanism for wireless communication, I/Q signals are used in phase modulation or frequency modulation. However, as long as the amplitude of the I/Q signals has a slight mismatch, the constellation diagram of the signals would be damaged, and the bit error rate (BER) of the communication system would also be increased. Thus, an amplifier with a highly precise gain is needed to accurately control the amplitude of the I/Q signals.
The gain drift of a conventional open-loop amplifier is rather large, so it cannot meet the requirement of highly precise gain. It is also difficult for a common closed-loop amplifier to precisely control its gain. FIG. 1 is a circuit diagram of a conventional closed-loop amplifier, which includes an operational amplifier (op-amp) 10, a resistor R1 coupled between the input of the whole circuit and the inverting input of the op-amp 10, and a feedback resistor R2 coupled between the output of the whole circuit and the inverting input of the op-amp 10. Vin and Vout are the input voltage and output voltage respectively. Since the properties of negative feedback and "virtual short", the gain (Vout /Vin) of the amplifying circuit in FIG. 1 can be derived as −R2/R1. By adjusting the resistor values of R1 and R2, a required gain is obtained. However, if a highly precise gain is required, e.g. 1.001, then the gain accuracy may be easily affected by a slight error of the resistor values of R1 and R2 since the difference between the values of R1 and R2 is rather small (e.g. R1=1 k ohm, R2=(1 k+1) ohm). In particular, when the amplifying circuit of FIG. 1 is implemented on an integrated circuit (IC), it is more difficult to achieve a highly precise gain since the factors of temperature, manufacturing process, supply voltage drift, etc. cannot be completely controlled.


A pilot-actuated, pressure-compensated flow and directional control valve assembly (11) is provided in which a main valve spool (95) is positioned in response to a pressure differential between a pilot chamber (119) and a reaction chamber (117). Flow of fluid from an inlet port (29) is controlled by means of a pilot valve assembly (97), into the pilot chamber (119), while fluid flows out of the pilot chamber (119) through a fixed orifice (67) to a pump load sense port (61). The main valve spool (95) acts as an inlet compensator. If the pressure at a load L is above inlet pressure, the main valve spool (95) acts as an inlet check, preventing reverse flow. If there is a higher load pressure at another load circuit in the system, such as a steering valve S, there will be an increase in pressure in the reaction chamber (117), thus closing off the main spool (95), reducing the flow from the inlet port (29) to the work port (47), and giving more priority to the steering valve S. If a priority circuit demands more flow at a lower pressure than the pump can provide to both circuits, the main spool (95) closes in an attempt to maintain a margin pressure which insures that the priority circuit gets the flow it needs.

The present invention relates to directional control valves, and more particularly, to such valves which are both pressure-compensated and pilot-operated.
The present invention is especially suited for use with proportional flow control valves, and will be described in connection therewith. By "proportional", it is meant that changes in the output flow of fluid from the control valve to the motor which is being controlled are generally proportional to changes in the input, which may be a mechanical input movement or an electromagnetic input, etc.
As will be described in greater detail subsequently, the present invention may be utilized advantageously in a four-way, three- or four-position directional and flow control valve, or in a three-way, three-position directional and flow control valve. For simplicity of illustration, the invention will be described in connection with a three-position, three-way valve. In most commercial directional and flow control valves, various added features are considered desirable, or perhaps even necessary, for the valve to be functionally satisfactory, one example of such an added feature would be the provision of inlet check valves, so that a load under high pressure cannot cause a back-flow (or reverse flow) from the load back through the valve and out the inlet port.
Pilot-operated flow control valves of the type to which the present invention relates are known, generally, from U.S. Pat. Nos. 2,526,709 and 2,600,348. In such pilot-operated valves, there is a main valve spool which is capable of controlling both direction and quantity of fluid flow from an inlet port to a work port. The position of the main valve spool is determined by a pilot pressure which results from movement of a pilot spool disposed slidably within the main valve spool. Movement of the pilot spool communicates pilot pressure to the appropriate end of the main valve spool to move the main valve spool to the desired position. In such pilot-operated valves, the relationship of the main valve spool to the pilot spool is simply that of a "follow-up", i.e., subsequent to movement of the pilot spool, the main valve spool follows the pilot spool until the main valve spool is again in a "neutral" position relative to the pilot spool. Typically, the only factor which determines the position of the main valve spool is the position of the pilot spool.
A typical pressure-compensated directional flow control valve is illustrated and described in U.S. Pat. No. 3,602,243, assigned to the assignee of the present invention and incorporated herein by reference. In such valves, there is typically a main valve spool, normally manually actuated, and a separate pressure-compensating valve section, the function of which is to regulate the flow from the inlet to the main valve spool to maintain a constant pressure differential across the main valve spool, regardless of the rate of fluid flow through the main valve spool. The pressure compensating valve typically includes a pressure-compensating spool which is positioned in response to the differential between inlet pressure and the pressure downstream of the main valve spool.
The addition of pressure compensation capability to a typical directional flow control valve adds substantially to the complexity of the valve section, requiring several additional "cores" in the valve housing casting, and a substantial amount of additional machining of the bore in which the pressure compensating spool is disposed. In addition, the pressure compensating spool itself, and any associated biasing springs, etc., represent a further added manufacturing cost.
If a particular directional flow control valve, whether pilot-operated, or pressure-compensated, is to be used in connection with a load sensing system, it is typically necessary to include within the system a load sensing priority flow control valve. The function of such a valve is to direct the appropriate amount of flow to a priority load circuit, while directing the remainder of the flow to an auxiliary load circuit. As is well known to those skilled in the art, typical load sensing priority flow control valves also add substantially to the cost and complexity of a typical hydraulic circuit.

Flow control valve with pilot operation and pressure compensation


The invention provides an apparatus including (a) a frame having a boundary plane; (b) a flow chamber supported by the frame, the flow chamber placed a distance from the boundary plane; (c) a radiation source, the radiation source directed away from the flow chamber and away from the exterior side of the boundary plane, and (d) a first reflective surface placed to direct a radiation beam in a path crossing the boundary plane to the flow chamber; (e) one or more reflective surfaces placed to direct a radiation beam from the radiation source to the first reflective surface, the path from the radiation source to the flow chamber being at least 1.5 times the distance from the flow chamber to the boundary plane.

This invention relates generally to separation of particles from mixtures and, more specifically, to flow cytometers for analyzing and sorting biological particles.
Flow cytometry is a valuable method for the analysis and isolation of biological particles such as cells and constituent molecules. As such it has a wide range of diagnostic and therapeutic applications. The method utilizes a fluid stream to linearly segregate particles such that they can pass, single file, through a detection apparatus. Individual cells can be distinguished according to their location in the fluid stream and the presence of detectable markers. Thus, a flow cytometer can be used to produce a diagnostic profile of a population of biological particles. For example, flow cytometry has been used to measure the decline or maintenance of immune cells during the course of treatment for HIV infection and to determine the presence or absence of tumor cells for prognosis and diagnosis of cancer patients.
Isolation of biological particles has been achieved by adding a sorting or collection capability to flow cytometers. Particles in a segregated stream, detected as having one or more desired characteristics, are individually isolated from the sample stream by mechanical or electrical removal. This method of flow sorting has been used to separate sperm bearing X and Y chromosomes for animal breeding, to sort chromosomes for genetic analysis, to isolate cells bearing specific antigens and to identify new organisms from complex biological populations.
Biological particles isolated by flow sorting can be used for a variety of diagnostic or therapeutic applications. However, impurities that co-fractionate with a biological particle of interest in a flow sorting method can produce false results in a diagnostic assay or can have adverse consequences in a therapeutic procedure. Thus, flow sorting methods often require decontamination procedures to remove unwanted residual materials between sample applications. One method of decontaminating a flow system is to flush or purge the devices that come into contact with sample. Such methods can be time consuming and costly and are often incomplete.
Currently, flow cytometers are bulky instruments that occupy large amounts of valuable laboratory and clinic space. Reduction in flow cytometer size has previously come at the expense of functionality or performance. One approach that has been used to minimize the space required for flow cytometry has been to design the instruments to replace multiple components with alternative components that are interchangeable. For example, multilaser flow cytometers have been made more compact by replacing multiple lasers and their optical paths with a single optical path through which different lasers can be separately directed. In this format a single laser is used while alternative lasers can be omitted or stored at a separate location. A disadvantage of this approach is that interchanging components can be time consuming, thereby reducing the throughput of the instrument or precluding the full range of analyses available for a single sample.
Thus, there exists a need for a flow cytometer that can be efficiently decontaminated. A need also exists for a flow cytometer having a variety of functions available in a compact format. The present invention satisfies these needs and provides related advantages as well.

Apparatus for analyzing and sorting biological particles


A method and system for controlling secondary assemblies of a motor vehicle, the motor vehicle having at least one deactivatable secondary assembly which generates a loss torque are provided. The method includes determining the current total loss torque acting on the drive train, determining the deactivation dead time of the at least one deactivatable secondary assembly, estimating the total loss torque resulting after passage of the deactivation dead time, and deactivating the at least one deactivatable secondary assembly if a predefined maximum torque threshold is exceeded by the estimated total loss torque.

The present invention relates to a method for controlling accessories of a motor vehicle, which act via a loss torque on the drivetrain of the motor vehicle.
Currently, vehicles are equipped, in regard to comfort and security, with ever more and/or ever larger accessories (a.k.a., secondary assemblies) such as the air-conditioning system (air-conditioning compressor), generator, power steering pumps, pumps for chassis stabilization, or the like. All of the secondary assemblies act indirectly or directly as producers of loss torques acting on the drivetrain, in that, because of their operation, in addition to the pure engine drive torque to be applied by the drive unit (e.g., internal combustion engine and/or electric motor) to accelerate the motor vehicle or solely to maintain idle operation without activated secondary assemblies, they load the drive unit with additional torque to be produced (so-called loss torque) for their own operation. In particular, in lower-power motors, the problem thus arises that the drive unit may not meet (or provide) the particular demanded total torque in every operating state. In this meaning, the torque converter of an automatic transmission also acts as a secondary assembly generating a loss torque.
The present invention is based on the object of specifying a method for controlling secondary assemblies of a motor vehicle, which act on the drivetrain of the motor vehicle via a loss torque, which ensures operation of the drive unit in conformity with demand in all operating states of the drive unit, and in particular prevents startup weakening or undesired snapping off (stopping) of the drive unit during idle operation.
The object is achieved according to the present invention by a method for controlling secondary assemblies of a motor vehicle including at least one deactivatable secondary assembly which generates a loss torque. By ascertaining and subsequently monitoring a total loss torque to be expected and possibly deactivating a deactivatable secondary assembly as a function of the monitoring result, secure operation of the drive unit in conformance with demand is ensured in every operating state. To ascertain the fictive total loss torque to be expected, the deactivation dead time (required time which passes from the instant of the deactivation command until the actual beginning of the deactivation procedure) of at least one deactivatable secondary assembly which generates a loss torque (referred to below as a deactivatable secondary assembly) is ascertained. If multiple deactivatable secondary assemblies are provided, at least the shortest deactivation dead time is ascertained. The deactivation dead time may be read out from a stored table of the deactivation dead times for all deactivatable secondary assemblies or from a memory area in the deactivatable secondary assembly itself.
Starting from the currently existing total loss torque (sum of the currently applied loss torques of all (active) secondary assemblies), it is then ascertained what fictive total loss torque (current total loss torque+loss torque of all (active) secondary assemblies after passage of the deactivation dead time of a secondary assembly potentially to be deactivated) would result after passage of the deactivation dead time used as a basis. The fictive total loss torque is estimated, for example, by calculating which torque may be absorbed at most by all participating secondary assemblies upon passage of the deactivation dead time. For this purpose, the currently absorbed torque, the maximum absorbable torque, and the maximum torque gradient are advantageously ascertained for every (active) secondary assembly. Finally, the ascertained total loss torque to be expected is compared to a predefined torque threshold (monitoring) and if the threshold is reached or exceeded, the secondary assembly whose deactivation dead time was used for ascertaining the loss torques of all secondary assemblies is deactivated (shut down).
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Method for controlling accessories of a motor vehicle

Bayerische Motoren Werke Aktiengesellschaft


A one piece shower stall is disclosed. The shower stall includes a generally horizontal base portion and a side wall portion that is unitarily interconnected to and extends upwardly from the base portion. The side wall portion terminates in an upper ledge having a generally horizontal upper surface that is sufficiently wide to support at least one of an outer wall covering and a shower door mechanism. A raised rim portion is unitarily interconnected to and surrounds the ledge. The rim portion includes a generally vertical surface for engaging at least one of an outer wall covering and a shower door mechanism and a continuous, generally horizontal surface that extends outwardly from the vertical surface to a periphery of the shower stall for supporting an inner wall covering.

While it is desirable to build shower stalls and bath tubs of constructions that are as strong as possible, and are as free as possible from the leaking of water, it is desirable to eliminate the possibilities of the leaking of water all together.
So many complaints have been raised to the fact that shower bases and tubs leak water around their upper edge where they contact other building materials that your applicant devoted his attention to this problem, and has succeeded in overcoming the leaks.

Cultured marble shower stall with raised edge


An uncured composite member is formed over a mandrel having a contour using a flexible compactor. Forming is performed outwardly from the apex of the contour.

1. Field
The present disclosure generally relates to processes for manufacturing composite structures, and deals more particularly with compaction of composite laminate stringers on contoured mandrel surfaces.
2. Background
Elongate composite members such as stringers used in the aircraft industry may be contoured in one or more planes along their length to conform to the curvature of a structure such as a fuselage skin. Contouring of a stringer may be accomplished using a compactor to compact an uncured stringer layup against contoured surfaces of a mandrel, such as a cure tool. Flexible compactors have been developed which flex or bend, allowing them to conform to contoured tool surfaces during the compaction process.
Depending on the degree of tool contour, the uncured stinger layup may develop wrinkles as it is being compacted against the tool, particularly near the center of curvature or greatest contour of the tool. This wrinkling occurs as a result of bending of the layers of composite material nearest the contoured tool surface, placing them in compression. Compression of the material in this manner causes excess material to accumulate and bunch into wrinkles. Wrinkling may have an undesired effect on the performance of the cured stringer.
Accordingly, there is a need for a method of compacting uncured composite members, such as stringers, on contoured tools, which controls material wrinkling. There is also a need for a method of compacting a stringer on a cure tool using a flexible compactor that reduces the size of the wrinkles while distributing the wrinkles generally uniformly along the length of the stringer.

Compacting uncured composite members on contoured mandrel surfaces


The present invention relates to a novel process for the synthesis of (per)fluoropolyether polymers, to certain novel (per)fluoropolyether polymers. The present invention also relates to the use of the (per)fluoropolyether polymers thus obtained as intermediate compounds for the manufacture of further polymers suitable for use as lubricants, notably for magnetic recording media (MRM).

Among fluorinated polymers, (per)fluoropolyether polymers (PFPEs) are well-known and of great interest for their chemical and physical properties, which make them particularly interesting as lubricants.
Several synthesis of PFPEs polymers have been disclosed in the art. The first synthesis of unspecified perfluorinated polyether mixtures was reported in 1953, when an oily product was obtained in the course of photoligomerization of hexafluoropropene. Since then, a number of different perfluorinated polyethers have been synthesized and described in literature. (ALLEN, Geoffrey, et al. COMPREHENSIVE POLYMER SCIENCE—Second supplement. Edited by SIR ALLEN, Geoffrey, et al. Elsevier Science, 1996. ISBN 0080427081. p. 347-388).
For example, the catalytic polymerization of perfluoroepoxides, such as notably hexafluoropropylene oxide (HFPO), firstly disclosed by Du Pont researchers, led to a product commercially available under the trade name Krytox®, which has a backbone comprising recurring units of formula —[CF(CF3)CF2O]y-. Then, Montedison researchers disclosed the photochemical oxidation of perfluoro-olefins, such as tetrafluoroethylene and hexafluoropropene, which led to a product commercially available under the trade name Fomblin®, which has a backbone comprising randomly distributed recurring units of formula —[(CF2O)m(CF2CF(R)O)n]— wherein R if —F or —CF3. Another synthesis, which involved the ring opening polymerisation of partially fluorinated oxetanes followed by fluorination, was disclosed by Daikin Company and led to a product commercially available under the trade name Demnum®, which has a backbone comprising recurring units of formula —(CF2CF2CF2O)p-.
The main difference between the (per)fluoropolyether polymers known in the art resides in the fact that Krytox® polymers and Demnum® polymers are homopolymers characterized by an ordered structure, which comprises only one type of recurring unit, i.e. —[CF(CF3)CF2O]y- and —(CF2CF2CF2O)p-, respectively. Differently, Fomblin® polymers are copolymers characterized by the presence of two or more recurring units having a different formula and being randomly (or statistically) distributed along the backbone chain. This random (or statistical) distribution of the recurring units is due to the manufacturing process, that is based on photochemical oxidation. However, the random distribution of the recurring units could led to a backbone chain comprising multiple consecutive recurring units having one carbon atoms (i.e., of formula —CF2O—), which on the one hand increase the flexibility of the polymer backbone but on the other hand constitute a weak point in the polymer backbone, as they are more easily attacked by metals and/or Lewis acids.
The polymerization of fluorinated vinyl ether alcohols, followed by fluorination of the intermediate partially-fluorinated structure, was disclosed by FEIRING, Andrew E. Synthesis of New Fluoropolymers: Tailoring Macromolecular Properties with FLuorinated Substituents. Journal of Macromolecular Science. 1994, vol. A31, no. 11, p. 1657-1673. However, the first approach described in this article starts from a partially fluorinated compound bearing within the same molecule both the hydroxy group and vinyl ether group (i.e., CF2═CFOCF2CF(CF3)OCF2CF2CH2OH), such that final polymer has a backbone comprising only one recurring unit of formula —(CF2CF2OCF2CF(CF3)OCF2CF2CF2O)n-. Another approach described in this article comprises the reaction between the compound mentioned above of formula CF2═CFOCF2CF(CF3)OCF2CF2CH2OH and a partially fluorinated diol (for example of formula HOCH2(CF2)3CH2OH) to provide telechelic macrodiols to be used for the production of further copolymers, such as for example those described in U.S. Pat. No. 5,185,421 (E.I. DU PONT DE NEMOURS AND COMPANY) and by YANG, S., et al. Novel fluorine-containing anionic aqueous polyurethane. Journal of Macromolecular Science. 1993, vol. 30, p. 241-252.
EP 3 059 265 (3M Innovative Properties Company) discloses curable fluoropolymer containing repeating units derived from VDF and TFE and at least one other fluorinated comonomer and further containing —CF2CH2I end groups and branching sites derived from one or more perfluorinated bisolefinic ether(s) used as modifier(s).
Nevertheless, no method has been made available which would enable synthesising with high yields and convenient manner partially (HFPE) and fully fluorinated polyether (PFPE) polymers containing cyclic structures in their main backbone.
Actually, the presence of a plurality of cyclic structures in the backbone of partially (HFPE) and fully fluorinated polyether (PFPE) polymers is an interesting structural feature for modifying chain mobility and confer to the resulting materials increased configurational stiffness, which would be particularly beneficial for improving certain advantageous properties, including notably their ability to perform as lubricants under severe conditions.