An electrochemical gas sensor cell is provided, the use of which permits quantitative measurement of volatile gas contaminants in an atmosphere being monitored. The cell comprises at least a first sensor electrode and a second counter electrode, on either side of an ion conductive electrolyte which may be immobilized in a matrix. The electrolyte may also be a solid electrolyte or a polymer electrolyte. The sensing electrode has a high surface area catalyst dispersed on a porous substrate, and is mounted in such a manner as to be exposed to the atmosphere which is to be sensed for gaseous contaminants, with the counter electrode being isolated from any exposure to that atmosphere. Generally, the electrodes are mounted in electrically conductive frames, sandwiching a third non-conductive frame member in which the ion conductive electrolyte is substantially located. The conductive frames may comprise electronically conductive materials such as conductive polymers, ceramics, nitrides, oxides and graphites. In an alternative embodiment, a further reference electrode may be mounted so as to be exposed to the electrolyte. The porous electrode may comprise a porous substrate or a base layer, a catalytically active metal, alloy, or metal oxide (usually a noble metal) dispersed in a high surface area form, carbon, and a polymeric hydrophobic binder.

In human inhabited environments, and in environments where other dangers such as explosion, fire or toxicity may occur, there is very often a requirement to test for gas contaminants which may create a health or safety hazard. In particular, there is an increasing demand for devices to monitor a specific-atmosphere--generally an enclosed volume--for toxic or flammable gases. Also, particularly where the atmosphere being monitored is inhabited by humans, there is a specific requirement for sensors having a rapid and reliable response to such contaminating gases as carbon monoxide, oxides of nitrogen, sulfur dioxide, hydrogen sulphide, carbon dioxide, hydrogen, phosphine, arsine, methanol, volatile hydrocarbons, and so on. Any such gas requires a specific sensor cell design, and in any given installation there may be several sensor cells of the present invention installed; each installed sensor cell having electrolytes and catalysts chosen for each of the sensor cells to be reactive to the presence of specific contaminating gases being tested for.
In some circumstances, the enclosed volume being monitored may be monitored only for one or two specific contaminating gases, which gases are the only likely gas contaminants to occur in such atmosphere being monitored. An example may be storage rooms where hazardous chemicals may be kept, or production facilities where hazardous materials are being released or are being used in the manufacture of other materials. In that case, the possible gas contaminants are known and specific cell systems may be designed accordingly.
To satisfy the requirement to be able to monitor for the presence of gas contaminants, it is not only necessary that sensor cells be provided that are capable of being economically produced and therefore readily purchased, it is also necessary that such sensor cells shall have a reasonably long active lifetime when installed in place. Moreover, particularly where it is necessary to monitor for toxic or flammable gases where there may be humans in the environment being monitored, or where there is a specific hazard, such sensors cells may be capable of detecting the presence of low concentrations of contaminant gases being tested for, so as to provide sufficient warning before the concentration of contaminant gas reaches dangerous levels.
The present invention provides gas sensor cells that have a catalytically active sensor electrode which is exposed to the atmosphere being monitored; where the sensor electrode is separated from a counter electrode which may also function as a reference electrode, or a counter electrode and a reference electrode, by a suitable ion conductive electrolyte. The nature of the electrolyte, and the manner in which it is retained in position, is discussed hereafter. It is important, however, that the sensor electrode must be sufficiently sensitive to low concentrations of gas contaminants in the atmosphere being tested, and examples of such electrodes are discussed hereafter.
The present invention provides a structure for the electrochemical gas sensor cells which is essentially of a sandwich-type construction, where the outer frame members secure the electrodes in place, and sandwich a third frame member between them in which all or at least a portion of the electrolyte is located. In the usual embodiments, the outer frame members are electrically conductive, so as to exhibit specific conductivity characteristics; and also so as to provide means for connecting external electrical measuring means (or, in yet another alternative embodiment, an external power source) directly to the sensor cell frame members. Moreover, the outer frame members of the electrochemical sensor cell of the present invention provide means for sealing the structure together, and thereby sealing means for the electrolyte chamber, as discussed hereafter. The third, intermediate, frame member is not electrically conductive, and it may be significantly thinner than the outer frame members.
Among the gases that may be tested for are gases and volatile substances as diverse as carbon monoxide, carbon dioxide, oxides of nitrogen, oxides of sulfur, hydrides of nitrogen such as ammonia and hydrazine, hydrides of phosphorus, sulfur, arsenic or boron, mercaptans, aldehydes, hydrogen, unsaturated and saturated hydrocarbon vapours, halocarbons and alcohols such as methanol. Indeed, in general a specific cell system can be devised using suitable catalysts and electrolytes to test for any toxic, combustible or flammable gas, or generally volatile substances which may be oxidizable. The enclosed volumes within which such gas contaminant monitoring may take place include those suggested above, and as well ordinary residential housing, parking garages of all sorts, vehicles, interiors of commercial or industrial buildings, hospitals, and mines.
Prior art devices have included various patented devices such as those described below; and in any event the prior art may generally be defined as comprising electrochemical sensors, ionization chamber sensors, photoelectric types of sensors, and metal oxide semiconductor devices. Most prior art sensors are solid stat or solid electrolyte, and may employ stabilized zirconia, yttria and tin oxides. However, any sensors that has heretofore been used for monitoring and/or controlling gas atmospheres has exhibited one or more of the following disadvantageous characteristics: (a) they most often have quite complex structures; (b) they very often must operate or can only operate at elevated temperatures (e.g. from 150.degree. C. to 600.degree. C.); (c) as well, or as a consequence of the above, they may require outside sources of electrical energy and/or heat to maintain their operating temperatures; (d) it follows that such devices may have long start-up or warm-up periods before reaching their operating characteristics; (e) moreover, nearly all prior art devices are costly to build and/or to operate; (f) and finally, the prior art devices are subject to deterioration over time, due to gas poisoning of their sensing systems and/or sensing elements.
Several specific prior art gas sensing elements or cells are as follows:
LaCONTI U.S. Pat. No. 4,025,412 describes a gas sensor which is capable of detecting oxidizable gases in air. The sensor cell is a laminated filter design, in which approximately ten components are used, placed on top of one another. The assembly is very expensive to produce, even in quantities, and the structure is susceptible to electrolyte leakage.
DEMPSEY et al, U.S. Pat. No. 4,227,984 provides a gas sensor having a solid polymer electrolyte, and being arranged so that a fixed potential difference between the reference and sensing electrodes is present at all times. The particular purpose of the Dempsey et al structure is to preclude the necessity for temperature compensation. DEMPSEY et al describe the use of noble metal and their alloys, or graphitic catalytic electrodes, whereby the catalyst particles are bonded to polymers such as PTFE. Thus, the electrodes comprise catalyst particles bonded to particles to a hydrophobic polymer, and as such they do not utilize a three dimensional sensing electrode active layer.
KITZELMANN et al, U.S. Pat. No. 4,394,239 teach an electrochemical sensor which is particularly adapted for detecting carbon monoxide. The electrochemical cell is enclosed in a plastic body, which serves only as a cell housing. Electrical connections are achieved by means of wires which are attached to the metal mesh embedded in the sensor and reference electrodes. Moreover, the acidic electrolyte is corrosive, thus expensive metals such as platinum have to be used as current collectors and electrical leads, resulting in increased costs. However, such metals are hydrophilic, which may result in electrolyte loss. KITZELMANN et al immobilize their electrolyte by forming a gel.
As to the KITZELMANN et al electrode, it is a sensing and counter electrode which contains platinum mesh as a current collector on the gas side. The platinum mesh contacts a carbon fleece, which has a layer of platinum black coated on it, and which contacts the immobilized electrolyte. The electrode-electrolyte-gas interface is a two dimensional zone which has an area substantially identical to the geometrical area of the electrode used. KITZELMANN et al make reference to conventional gas diffusion electrodes (col. 3, lines 1-8) which could require the sensing gas to be delivered into the sensing electrode under pressure, or which may be required to be rendered hydrophobic to avoid spilling of electrolyte.
VENKATASETTY, U.S. Pat. No. 4,522,690, in a structure intended particularly for sensing the presence of carbon monoxide, requires the use of a gelled aprotic organic non-aqueous electrolyte in which the contaminant gas to be detected is soluble together with platinum sensor and counter electrodes, and a silver reference electrode. VENKATASETTY utilizes a platinum film as the active part of the sensing electrode, and in the same manner as KITZELMANN et al, thus uses a two dimensional reaction-interface approach. Moreover, the VENKATASETTY structure is extremely expensive to produce, even in quantities.
HANDA et al, U.S. Pat. No. 4,543,273 teach a structure for sensing carbon monoxide, where a solid oxide electrolyte is used. The patent, however, relates particularly to the production of the sensing element, at very high temperatures (above 600.degree. C.). The sensor utilizes changes of conductivity of the sensing elements in the presence of gas contaminants so as to sense their concentration.
YAMAZOE et al, U.S. Pat. No. 4,718,992, describe a proton conductor gas sensor for the detection of hydrogen or carbon dioxide. In the sensing device, a pair of electrodes that are connected by a proton conductor are short circuited to cause protons to travel through the proton conductor. The difference in activity between the electrodes, or the difference in gas permeability between the electrode and the atmosphere, is used to detect various gas contaminants. The potential difference created within the proton conductor due to the proton movement is used as sensor output which is proportional to the concentration of the gas contaminant, and is relatively insensitive to humidity changes.
Co-pending application Ser. No. 07/513,441, referred to above, describes a novel sensor cell design where the cell is encapsulated. In that cell, conductive and non-conductive plastic materials are used from the sensor cell housing the plastic sensor cell is capable of making quantitative measurement of volatile gas contaminants at ambient temperatures below 100.degree. C.
In contradistinction to the above, the present invention provides sensitive electrochemical cells, and the electrodes for use therein, which will detect the presence of low concentrations of contaminating gases in air or other environments where they may be a possibility of dangerous or hazardous accumulations of such contaminating gases. These cells, and their electrodes, have the following advantageous characteristics: (a) the structure, and their production, are very simple; (b) they operate at various temperatures and do not require temperature control, nor do they require heaters to reach operating temperature; (c) they have a fast response time; (d) they have a high activity level, by which they may become active in the presence of very low concentrations of contaminating gas; (e) they are stable in their operation; (f) they have a long operating life; (g) and finally, they are inexpensive to produce.
The present invention provides an electrochemical gas sensor cell for quantitative measurement of gas contaminants in an atmosphere being monitored. In several of the preferred embodiments, the temperature of the gas atmosphere may be significantly higher than 100.degree. C. In any event, the gas sensor cells can be operated at temperatures up to the latent boiling or melting temperature of any of the sensor components being used. The gas sensor cell has a first sensor electrode mounted in a first frame member, a second counter electrode mounted in a second frame member, and a third frame member which contains an electrolyte chamber, where the first and second frame members are at opposite sides, respectively, of the third frame member which substantially contains the electrolyte. The manner in which the electrolyte is retained is such as to substantially accommodate changes in temperature or humidity of the atmosphere. Each of the first, second, and third frame members are formed of materials which are inert and impervious to the electrolyte. Those materials may be plastics, such as polypropylene, polyvinylidene difluoride, or acrylonitrile butadiene styrene (ABS), any of which may be filled with metals, carbon or graphite, or combinations thereof. Other suitable materials include ceramics which can be electrically non-conductive ceramics such as boron nitride, aluminum oxide, silica, or glass; or electrically conductive ceramics such as EBONEX.TM.--which is essentially Ti.sub.x O.sub.2x-1, where x=4 to 10 (usually x=4)--or other metal oxides, carbides, or sulfides, etc., may also be used.
At least the first sensor electrode, and optionally the second counter electrode is a porous electrode, with the first sensor electrode and optionally the second counter electrode having a catalyst dispersed thereon.
The sensor electrode is mounted in the first frame member so as to be exposed to the atmosphere being monitored, and the counter electrode is mounted in the second frame member so as to be isolated from any exposure to that atmosphere. Conductor means are associated with each of the first and second electrodes, and are connected to electrical measurement means and may also be optionally connected to additional electrical devices such as control or warning devices.
Thus, when the atmosphere being monitored contains a gas contaminant for which the catalyst on at least the sensor electrode and the electrolyte have been chosen to produce a change in the electrical characteristics of the sensor electrode with respect to the counter electrode in the presence of that gas contaminant, the electrical measurement means detects the change of electrical characteristic in such circumstances, the change of electrical characteristic being indicative of the presence of the gas contaminant being tested for. In that sense, the electrical characteristic may optionally provide a display of contaminant concentration, it may trigger a warning or control device, or it may be stored in a storage or memory device for later comparison and review. What that means is that electrical characteristic may be a potential which changes between the sensor electrode and the counter electrode, or the current flowing between those electrodes may change.
In an alternative embodiment, a reference electrode is located so as to be exposed to the electrolyte, and potentiometric measurement means are provided between the sensor electrode and the reference electrode, as well as the electrical measurement means being between the sensor electrode and the counter electrode.
The electrolyte may be immobilized by being absorbed in a matrix contained within the electrolyte chamber, or it may an ionically conductive solid polymer or ceramic electrolyte, or it may be a solid electrolyte capable of ionic motion within a solid lattice. Moreover, the electrolyte chamber may be in communication with an electrolyte reservoir which is formed within the third frame member, above the electrolyte chamber. Moreover, the electrolyte chamber may also extend into the first and second frame members.
Each of the first and second frame members may be electrically conductive plastics materials, or suitable polymer composites, or electrically conductive ceramics. The plastics materials of the frame members may be such as polypropylene, polyvinylidene difluoride, or acrylonitrile butadiene styrene (ABS), any of which may be filled with metal, carbon or graphite, or combinations thereof.
Other suitable stable and impervious polymers include polyvinyl chloride or acrylonitrile butadiene; suitable electrically conductive inert filler materials include titanium oxide, tungsten carbide and the like. Other inert conducting polymers may be such as those described in the Handbook of Conducting Plastics, Volumes 1 & 2, Marcel Dekker, 1986.
Certain suitable materials for use in the conductive frame member may be conductive ceramics such as EBONEX, (comprising Ti.sub.4 O.sub.7), other conductive titanium oxide compositions such as Ti.sub.5 O.sub.9 and TiO, other inert conductive metal oxides, i.e. Na.sub.2 WO.sub.3 carbides (e.g., WC, TiC, ZnC, Cr.sub.3 C.sub.2, etc.), sulfides (e.g., WS.sub.2, MoS.sub.2, etc.) borides and graphites, carbon and graphites, etc. as well as their mixtures such as TiC+C and doped materials.
In specific embodiments of the present invention, the second counter electrode may be exposed to a contained volume of cleaned or scrubbed air or other suitable gas which is substantially free of the gaseous contaminant being tested for. Moreover, in those circumstances the counter electrode is non-polarizable under ordinary operating conditions.
In a further embodiment of the present invention, the non-conducting polymer of the third frame member may have its surface plated with a suitable inert metal film such as gold, silver, platinum, or the like.
Potentiometric electric measurement means may be provided, whereby a change in the voltage developed between the sensor electrode and the counter electrode may be detected and measured. The electrical measurement means may also be amperiometric.
The catalyst, or the specific catalyst for each of the sensor electrode and optionally the counter electrode, is dispersed on the porous electrode substrate in such a manner as to have a high surface area. The catalyst of choice may be a high surface area noble metal supported or carbon, carbides, or other conductive substrates.
Still further, the present invention provides porous electrodes which may comprise at least one porous layer containing a catalytically active metal, alloy, or metal oxide--usually comprising at least one noble metal--carbon, and a polymeric hydrophobic binder. These electrodes may then be used in gas sensors according to the present invention, together with a stabilized liquid electrolyte or other suitable electrolyte; and are such that they may operate at ambient temperatures such as room temperature without the necessity for a prolonged start-up or warm-up period.
In the case of the electrolyte being a solid polymer or an ion conductive solid state material, an appropriate amount of electrolyte may be incorporated into the electrode during the fabrication process to facilitate "wetting" of the electrocatalyst. Alternatively, the finished electrode may be impregnated by the electrolyte in its liquid form--for example, DuPont NAFION.TM. dissolved in alcohol, or solid state salts in their molten form or dissolved in a suitable solvent. In any event, the objective is to create a three dimensional interface between the electrolyte, the electrocatalytically active sites, and the gas contaminant within the sensing electrode, so as to increase the sensitivity and reactivity of the sensing electrode based on the geometrical electrode surface area.
The present invention also provides methods for making the electrochemical gas sensor cell, where the assembly method may be such that the assembled frame members are exposed to heat at a temperature of less than about 400.degree. C. for a predetermined period of time, depending on the material being used. Indeed, particularly when plastic frame members are to be used, the methods of the present invention to provide the electrochemical gas sensor cell may be carried out at the relatively low processing temperature of about 165.degree. C., or they may carried out in an induction furnace; or when the surfaces of the frame members which face each other are coated with a titanium oxide powder, the assembly may take place using microwave technology.
Indeed, the electrochemical gas sensor cell of the present invention may be produced by injection moulding the exterior frame members around the other members of the cell which are already held in place within an injection mould.
In the case where at least one of the frame members is made entirely without the use of plastic materials--such as in the case of EBONEX conductive frame members--the sensor cell can be assembled by applying an inert adhesive such as a pressure sensitive adhesive onto the frame members to be joined. Then, the sensor cell can be assembled by merely applying slight pressure at room temperature to activate the pressure sensitive adhesive used. Of course other inert adhesives, epoxides, or hot melts can be utilized as well.
By all of the above, the present invention provides a low cost electrochemical gas sensor cell which may be arranged by the choice of suitable and specific catalysts and electrolytes to sense low concentrations of specific gases being tested for, and provide a rapid and reliable response in the presence of such gaseous or volatile contaminant.

Electrochemical gas sensor cells using three dimensional sensing electrodes


Resources associated with a communication system switch are monitored by storing information defining one or more resource groups. Each of the resource groups includes multiple identifiers, with each of the identifiers specifying at least one resource to be monitored. A client external to the switch is permitted to select at least one of the resource groups for monitoring. In response to selection of one of the groups by the client, monitoring of the corresponding resources is established on behalf of the client. The resource monitoring may be established, controlled and maintained by a telephony server coupled between the client and the switch. Such a telephony server can preserve monitoring for a resource group, independent of the requests of clients, in order to reduce the amount of execution time needed to set up and tear down monitors for client applications. This is particularly advantageous in call centers or in other client applications that involve monitoring large numbers of switch resources.

Examples of conventional communication system switches include private branch exchanges (PBXs) and automatic call distribution (ACD) systems. As is well known, such switches may be controlled via computer-telephony integration (CTI) applications running on computers internal or external to the corresponding enterprise communication platform. CTI applications are commonly used in call centers and other enterprise call processing contexts.
An important function of CTI applications in these contexts involves the monitoring of switch resources. For example, most CTI applications require information regarding dynamic telephony activity for specific enterprise communication platform resources, such as agent terminals and other system endpoints, ACD devices, etc. The CTI applications use this information to make most effective use of the monitored resources in processing incoming and outgoing calls. Current CTI application programming interfaces (APIs), such as Telephony Services Application Programming Interface (TSAPI), Java Telephony Application Programming Interface (JTAPI) and Telephony Application Program Interface (TAPI), and their associated protocols each provide a mechanism for a CTI application to request notification of any activity involving a particular telephony resource.
In a typical conventional resource monitoring arrangement, the CTI application first sets up a communication session with an enterprise communication platform, often through a corresponding gateway device. As part of this session, the CTI application supplies any required authentication information. The CTI application then sends a series of resource monitor requests, generally one request per resource on the targeted platform. Activity events involving the monitored telephony resources are communicated to the waiting application within the established session.
Unfortunately, there are a number of significant problems with the conventional resource monitoring approach described above. For example, the above-noted example CTI APIs typically require that resource monitoring requests be issued one at a time, resulting in an unduly complex arrangement when there are a large number of resources to monitor. Moreover, since each CTI application is responsible for generating its own individual resource monitoring requests, redundant lists of monitored resources may be present in different CTI applications, or one or more of the lists may be inconsistent with the actual resources present at any given time in the enterprise communication platform. Yet another problem is that the individual resource monitoring requests typically have to be regenerated each time a given CTI application is restarted, which can result in excessive execution time. As a more particular example, a CTI application running on a client machine may crash, in which case existing monitoring arrangements will be terminated and must be reestablished, at the cost of additional execution time.
Existing API function calls fail to provide an adequate solution to one or more of the problems identified above. These example function calls include the Genesys T-Library API call TRegisterAll, described in the T-Server 5.1.5 Developer's Guide, Chapter 3, "Feature Requests," p. 85, which registers a CTI application to receive events regarding all telephony "objects" associated with a given CTI link, and the JAIN™ Call Control (JCC) API call CreateEventFilterAddress*( ), described at http://java.sun.com/products/jain, which allows the specification of event filters.
Other similarly-deficient techniques are described in, for example, ECMA 269, Services for Computer Supported Telecommunications (CSTA) Phase III, Fourth Edition, June, 2000, http://www.ecma.ch, Sections 22.214.171.124.3, 184.108.40.206.5 and 126.96.36.199. See also ISO/IEC 18051:2000(E) International Standard, Information technology—Telecommunications and information exchange between systems—Services for Computer Supported Telecommunications Applications (CSTA) Phase III, Jul. 15, 2000.
As is apparent from the foregoing, a need exists for an improved approach to monitoring of switch resources via CTI applications or other monitoring mechanisms.

Method and apparatus for monitoring of switch resources using resource group definitions


A small hole diameter measuring apparatus including: a flow rate measurement section comprised of an automatic pressure control device which supplies a fluid to the inlet side of small holes in a plate while maintaining the outlet- and inlet-side pressures of the small holes in the critical state of the fluid and controlling the inlet-side pressure to a predetermined inlet-side pressure; a plate holding section comprised of a plate supporting device which rotatably holds the plate, and a test probe supporting device which supports a test probe so that the test probe is moved vertically and horizontally; and a control section comprised of a calculation and judgment part, which calculates the hole diameter during the supply of the fluid based upon the measured value of the flow rate from the flow rate measurement section, and an external output part, which outputs the calculated value to the outside.

1. Technical Field
The present invention relates to the measurement of the diameters of small holes formed in a substrate and more specifically relates to an improved system for the automatic measurement of the diameters of small holes formed in a plate such as the orifice diameter of a shower plate used for the disperse supply of a fluid (gas) in, for example, the vacuum chamber of a semiconductor manufacturing apparatus or the like. More concretely, the present invention relates to a small hole diameter measurement system for a plate in which the effective internal diameters of a plurality of small holes formed in a single plate can be automatically measured quickly and with high precision.
2. Description of the Related Art
In semiconductor manufacturing equipment and liquid crystal displays, due to an increase in the size of the materials that are treated, it is necessary to maintain in-plane uniformity. Accordingly, for example, in vacuum chambers used in semiconductor manufacture, a technique is generally practiced in which a plate having numerous small holes is disposed in the inside upper part of the chamber, and various treatment gases are supplied to the top of the material being treated (e.g., silicon wafer) via this plate.
A plate of this type is ordinarily formed from a stainless steel material, ceramic material or the like with a thickness of approximately 3 to 30 mm and an external diameter of approximately 100 mm to 300 mm. Approximately 20 to 100 small holes having a circular cross-sectional shape with an internal diameter of approximately 50 μm to 3000 μm are formed either regularly or irregularly in this plate.
The above-described small holes are formed by mechanical working or chemical working, and the working precision is restricted to a precision of ±1 μm (error dimension) or better.
Since the diameter of the small holes in the above-described plate is directly related to the amount of treatment gas that is caused to jet into the chamber, this diameter must be strictly controlled; and various techniques for this have been developed in the past.
Among these techniques, (a) a method in which compressed air is supplied from one end of the small holes, and the internal diameter of the small holes is detected from the variation in the air back pressure on the outlet side of the small holes (e.g., Japanese Patent Application Laid-Open (Kokai) No. 2003-65742), and (b) a method in which the diameter of the small holes is detected from the flow rate of the gas that flows through the small holes (e.g., Japanese National Patent Publication No. H4-502666), have attracted attention as techniques that can be adapted for practical use.
However, in the case of the method of (a) described above, the direct object of the method is the measurement of the internal diameter of a pipe-form body that has a relatively small diameter; accordingly, in cases where the object of measurement consists of small holes with a circular cross-sectional shape that are formed in a plate, since the length of the small holes is relatively short, the following problem arises: namely, the pressure on the outlet side of the small holes (back pressure) cannot be measured simply and with a high degree of precision.
Meanwhile, in the case of the latter method of (b), as shown in FIG. 8, an air current is caused to flow into the small holes that are the object of detection under critical conditions, the temperature of the air current is measured by a temperature detection device, the flow rate of the air is measured by a differential type flow meter, and the effective cross-sectional area of the small holes is calculated using the above-described measured value of the air flow rate and the above-described measured value of the air temperature.
In FIG. 8, the reference numeral 20 indicates a filter, 21 indicates a differential type flow rate measuring device in which numerous tube bodies 22 are combined side by side, 23 indicates the small holes that constitute the object of detection, 24 indicates a vacuum pump, 25 indicates a pressure gauge, and 26 indicates a thermometer.
In the measurement of the internal diameter of the small holes 23, first the air flow-through system is placed under so-called critical conditions by operating the vacuum pump 24 (P1/P2>2), the flow rate VE of the air that flows through the small holes 23 is measured by means of a differential type flow rate measuring device 21, and the air temperature T is measured.
The cross-sectional area A of the small holes is next calculated from the respective measured values using the following formula:A=K′·VE·[1−0.0017(T−20)]
wherein, K′ is a constant, VE is the measured value of the volumetric flow rate of the air, and T is the air temperature (° C.).
However, the method of (b) described above has a problem: a so-called differential type flow meter is used in which the volumetric flow rate VE of the air is calculated using the differential pressure ΔP of laminar flow regions that are formed by combining numerous tube bodies 22 side by side; accordingly, the construction of the flow meter itself becomes complicated, and it is difficult to measure the volumetric flow rate VE of the air with a high degree of precision.
Furthermore, in the method of (b) described above, the cross-sectional area A of the small holes 23 is calculated using a formula as described above. However, in cases where the length dimension of the small holes 23 is relatively long (e.g., 3 to 10 mm), and a plurality of areas where the cross-sectional area A varies are present in the longitudinal direction of the small holes, it becomes difficult to measure the cross-sectional area A of the small holes 23 accurately using the formula described above because of the effects of the viscosity of the air current and like, and it has been demonstrated that a large error is generated in verification tests conducted by the inventors of the present application.
Moreover, in the case of the method of (b), the replacement of the small holes 23 that constitute the object of inspection takes time and trouble; accordingly, if the object of inspection is numerous small holes formed in a plate, it is difficult to measure the internal diameter of the small holes efficiently and with a high degree of precision.
In addition, in the case of the method of (b), absolutely no consideration is given to the automatic replacement of the small holes 23 that constitute the object of inspection or the processing of the measured small hole diameter results (e.g., ascertaining the acceptability of the inspection results for the small hole diameters or transmission of the results of such evaluation); accordingly, such a method cannot easily be applied to actual semiconductor manufacturing plants.
Furthermore, it is difficult to control the flow rate of the gas that flows out of the small holes with a high degree of precision merely by controlling the internal diameter of the small holes. The reason for this is that the gas flow rate fluctuates greatly not only according to the internal diameter of the small holes, but also according to the degree of roundness, depth, presence or absence of a taper, and the like.

Small hole diameter automatic measuring apparatus, small hole diameter measurement method, and shower plate manufacturing method


A method of supervising a plurality of displaced devices includes having each device emit a supervisory signal that is detectable by a designated unit. Indicia can be included indicative that an intervening message has been sent from a respective device. The designated unit can respond to missing, expected supervisory signals as well as unreceived messages.

Various types of monitoring systems such as fire or gas alarm systems, built-in control systems, security systems and the like carry out functions which preferably can be relied on to provide warnings relative to developing conditions which are in need of attention. It has been recognized that it is desirable to supervise the function of the components of such systems to minimize the likelihood that one or more portions of such systems might fail and not give any indication thereof. For example, where the systems are configured as networks of devices, it would be desirable to know if any transmitted messages were not received, or, if a respective device or devices had malfunctioned in some way. It would also be desirable to incorporate supervision capabilities which can be carried out automatically on an ongoing basis without substantially adding to the cost or complexity of such systems.

Systems and methods of deterministic annunciation


A device for regulating a flow of electric current and its manufacturing method are provided. The device includes metal-insulator-semiconductor source-drain contacts forming Schottky barrier or Schottky-like junctions to the semiconductor substrate. The device includes an interfacial layer between the semiconductor substrate and a metal source and/or drain electrode, thereby dynamically adjusting a Schottky barrier height by applying different bias conditions. The dynamic Schottky barrier modulation provides increased electric current for low drain bias conditions, reducing the sub-linear turn-on characteristic of Schottky barrier MOSFET devices and improving device performance.

One type of transistor known in the art is a Schottky-barrier metal oxide semiconductor field effect transistor (Schottky-barrier MOSFET or SBMOS). As shown in FIG. 1, the SB-MOS device 100 comprises a semiconductor substrate 110 in which a source electrode 120 and a drain electrode 125 electrode are formed, separated by a channel region 140 having channel dopants. The channel region 140 is the current-carrying region of the substrate 110. For purposes of the present invention, the channel region 140 in the semiconductor substrate extends vertically below the gate insulator 150 to a boundary approximately aligned with the bottom edge of the source 120 and bottom edge of the drain 125 electrodes. The channel dopant concentration profile typically has a maximum concentration 115, which is below the source 120 and drain 125 electrodes, and thus outside of the channel region 140. For the purpose of the present invention, channel dopants are not constrained to be provided exclusively within the channel region 140, but may be found in regions substantially outside of the channel region 140.
For a SB-MOS device at least one of the source 120 or the drain 125 contacts is composed partially or fully of a metal silicide. Because at least one of the source 120 or the drain 125 contacts is composed in part of a metal, they form Schottky or Schottky-like contacts 130,135 with the substrate 110 and the channel region 140. A Schottky contact is defined as a contact formed by the intimate contact between a metal and a semiconductor, and a Schottky-like contact is defined as a contact formed by the close proximity of a semiconductor and a metal. The Schottky contacts or Schottky-like contacts or junctions 130, 135 may be provided by forming the source 120 or the drain 125 from a metal silicide. The channel length is defined as the distance from the source 120 contact to the drain 125 contact, laterally across the channel region 140.
The Schottky or Schottky-like contacts 130, 135 are located in an area adjacent to the channel region 140 formed between the source 120 and drain 125. An insulating layer 150 is located on top of the channel region 140. The insulating layer 150 is composed of a material such as silicon dioxide. The channel region 140 extends vertically from the insulating layer 150 to the bottom of the source 120 and drain 125 electrodes. A gate electrode 160 is positioned on top of the insulating layer 150, and a thin insulating layer 170 surrounds the gate electrode 160. The thin insulating layer 170 is also known as the spacer. The gate electrode 160 may be doped poly silicon. The source 120 and drain 125 electrodes may extend laterally below the spacer 170 and gate electrode 160. A field oxide 190 electrically isolates devices from one another. An exemplary Schottky-barrier device is disclosed in Spinnaker's U.S. Pat. No. 6,303,479.
Another type of MOSFET transistor known in the art is a conventional impurity-doped source-drain transistor or conventional MOSFET. This device is similar to the SB-MOS device shown in FIG. 1. The key difference is that the metal source-drain regions 120,125 of the SB-MOS are replaced with impurity doping in the semiconductor substrate for the conventional MOSFET.
One of the important performance characteristics for a MOSFET device is the drive current (Id), which is the electrical current from source to drain when the applied source voltage (Vs) is grounded, and the gate (Vg) and drain (Vd) are biased at the supply voltage (Vdd). Drive current is one of the important parameters that determines circuit performance. For example, the switching speed of a transistor scales as Id, so that higher drive current devices switch faster, thereby providing higher performance integrated circuits.
FIG. 2 shows the relationship of drive current (Id) 232 for varying gate voltage (Vg) and drain voltage (Vd) 231 for a SB-MOS and a conventional MOSFET. One characteristic of SB-MOS device Id-Vd curves is the sub-linear shape for low Vd 231, as shown by the solid lines 210,215,220,225,230. Each of the Id-Vd curves 210,215,220,225,230 has a different Vg. The Id-Vd profile at low Vd is known as the turn-on characteristic. Conventional MOSFET transistor technologies have a linear Id-Vd turn-on characteristic at low Vd, as shown by the dashed lines 235,240,245,250,255 in FIG. 2. Each of the Id-Vd curves 235,240,245,250,255 has a different Vg. The sub-linear Id-Vd turn-on characteristic of the SB-MOS device increases as the channel length decreases and can potentially reduce transistor performance, possibly reducing the effective switching speed of the device for example. Sub-linear turn-on has been observed in the literature and referenced as a reason why SB-MOS devices will not be of practicable use in integrated circuits (B. Winstead et al., IEEE Transactions on Electron Devices, 2000, pp. 1241-1246). Industry literature consistently teaches that the Schottky barrier height φb should be reduced or made less than zero in order to minimize the sub-linear turn-on phenomenon and thus to make SB-MOS device performance competitive with alternative MOSFET device technologies (J. Kedzierski et al., IEDM, 2000, pp. 57-60; E. Dubois et al., Solid State Electronics, 2002, pp. 997-1004; J. Guo et al., IEEE Transaction on Electron Devices, 2002, pp. 1897-1902; K. Ikeda et al., IEEE Electronic Device Letters, 2002, pp. 670-672; M. Tao et al., Applied Physics Letters, 2003, pp. 2593-2595).
There is a need in the industry for teaching a SB-MOS device and method of fabrication that provides a means for improving the turn-on characteristic thereby providing improved performance.

Dynamic Schottky barrier MOSFET device and method of manufacture


A system for identifying and determining the orientation and location of multiple objects includes a camera and a mechanism for permitting the camera to scan a scene containing the objects. Objects in the moving scene are identified by optical filtering. Filters representing each of the objects to be identified are stored in a digital image memory, from which they are retrieved as needed, Fourier transformed, and loaded into a spatial light modulator to form a matched filter for an input image modulated and transformed laser beam.

1. Field of the Invention
This invention relates to a system for identifying objects in a combined circularly scanned image and determining their location and orientation.
2. Description of the Related Art
A variety of optical and electronic image processing techniques have been developed for the purpose of automatically identifying objects in an image. Optical techniques are especially suitable for use in applications requiring real time processing of a large amount of image information. The filters and lenses used in such systems transform entire images at the speed of light, in contrast to purely electronic image processing systems which generally process image information serially, pixel by pixel.
A device known as the "spatial light modulator" (SLM) has recently become available for use in converting electronic information into optical form, using a coherent light beam as a carrier of the information. The SLM is essentially a filter whose optical characteristics are varied in response to an electrical input signal. This allows conversion of information from electronic to optical form, in a manner which optimizes the different advantages of electronic and optical systems in a combined electronic and optical image processing system.
Identification of objects in an image involves the process known as "matched filtering". This process is based upon a correlation function produced by taking the inverse Fourier transform of the Fourier transforms of an input image and a complex conjugate reference image. Various lens systems are currently available for performing the Fourier transform of image information contained in a coherent beam of light. Comparison of the images is accomplished by combining the Fourier transforms of each image. The resulting "correlation spots" are an indication of the degree of correlation between the two images. This type of optical matched filtering system is useful for comparing input images with a limited number of matched filters, but because the references images are conventionally stored in optical form, the system is much less useful in applications involving a greater number of reference images. These applications include parts retrieval systems, autonomous guidance and artificial intelligence systems for land, air and space vehicles, and surveillance systems.

Circularly scanned electronically addressed optical correlator


A method of communications channel coding gain optimization using combined ISI cancellation and turbo decoding is provided. Log-likelihood ratio probabilities with extrinsic values are computed from previous iterations of turbo decoding and used to compute the soft-decision values of channel symbols. The soft-decision values are then used to perform intersymbol interference cancellation and generate refined channel log-likelihood ratio probabilities for the next iteration of turbo decoding.

I. Field of the Invention
The present invention relates to the field of information coding for communications systems, and more specifically to intersymbol interference cancellation and turbo coding.
II. Background
Transmission of digital data is inherently prone to noise and interference, which may introduce errors into the transmitted data. Error detection schemes have been suggested to determine as reliably as possible whether errors have been introduced into the transmitted data. For example, it is common to transmit data in packets and add to each packet a cyclic redundancy check (CRC) field, for example of a length of sixteen bits, which carries a checksum of the data of the packet.
When a receiver receives the data, the receiver calculates the same checksum on the received data and verifies whether the result of the calculation is identical to the checksum in the CRC field.
When the transmitted data is not used in real time, it is possible to request retransmission of erroneous data when errors are detected. However, reducing the transmission errors at the receiver reduces such requests, improving the efficiency of transmission. Moreover, when the transmission is performed in real time, such as, e.g., in telephone lines, cellular phones, remote video systems, etc., it is not possible to request retransmission.
Various forward error correction (FEC) coding techniques have been introduced to allow receivers of digital data to correctly determine the transmitted data even when errors may have occurred during transmission. For example, convolutional codes introduce redundancy into the transmitted data such that each bit is dependent on earlier bits in the sequence. Thus, when errors occur, the receiver can still deduce the original data by tracing back possible sequences in the received data. Moreover, the coded transmitted data may be packed into data packets.
To further improve the performance of a transmission channel, some coding schemes include interleavers, which rearrange the order of the coded bits in the packet. Thus, when interference destroys some adjacent bits during transmission, the effect of the interference is spread out over the entire original packet and can more readily be overcome by the decoding process. Other improvements may include multiple-component codes that encode the packet more than once, in parallel or in series. For example, it is known in the art to employ concatenated coding, and error correction methods that use at least two convolutional coders serially or in parallel. Such parallel encoding is commonly referred to as turbo coding.
For multiple-component codes, optimal decoding is often a very complex task, and may require large periods of time not usually available for real time decoding. Iterative decoding techniques have been developed to overcome this problem. Rather than determining immediately whether received bits are zero or one, the receiver assigns each bit a value on a multilevel scale representative of the probability that the bit is one. A common scale of such probabilities, referred to as log-likelihood ratio (LLR), represents each bit by a real number or, more commonly, an integer in some range, e.g., {−32,31}. A value of 31 signifies that the transmitted bit was a zero with very high probability, and a value of −32 signifies that the transmitted bit was a one, with very high probability. A value of zero indicates that the logical bit value is indeterminate.
Data represented on the multilevel scale is referred to as "soft data," and iterative decoding is usually soft-in/soft-out, i.e., the decoding process receives a sequence of inputs corresponding to probabilities for the bit values and provides as output corrected probabilities, taking into account constraints of the code. Generally, a decoder that performs iterative decoding uses soft data from former iterations to decode the soft data read by the receiver. During iterative decoding of multiple-component codes, the decoder uses results from decoding of one code to improve the decoding of the second code. When serial encoders are used, two decoders may be used serially for this purpose. When parallel encoders are used, as in turbo coding, two corresponding decoders may conveniently be used in parallel for this purpose. Such iterative decoding is carried out for a plurality of iterations until it is believed that the soft data closely represents the transmitted data. Those bits that have a probability indicating that they are closer to one (for example, between 0 and 31 on the scale described above) are assigned binary zero, and the remaining bits are assigned binary one.
"Turbo coding" represents an important advancement in the area of FEC. There are many variants of turbo coding, but most types of turbo coding use multiple encoding steps separated by interleaving steps combined with the use of iterative decoding. This combination provides previously unavailable performance with respect to noise tolerance in a communications system. Namely, turbo coding allows communications at levels of energy-per-bit per noise power spectral density (Eb/N0) that were previously unacceptable using the existing forward error correction techniques.
Many communications systems use forward error correction techniques and therefore would benefit from the use of turbo coding. For example, turbo codes could improve the performance of wireless satellite links, in which the limited downlink transmit power of the satellite necessitates receiver systems that can operate at low Eb/N0 levels.
Digital wireless telecommunication systems, such as, e.g., digital cellular and PCS telephone systems, also use forward error correction. For example, the Telecommunications Industry Association has promulgated the over-the-air interface standard TIA/EIA Interim Standard 95, and its derivatives, such as, e.g., IS-95B (hereinafter referred to collectively as IS-95), which define a digital wireless communications system that uses convolutional encoding to provide coding gain to increase the capacity of the system. A system and method for processing radio-frequency (RF) signals substantially in accordance with the use of the IS-95 standard is described in U.S. Pat. No. 5,103,459, which is assigned to the assignee of the present invention and fully incorporated herein by reference.
Transmission of digital data is also inherently prone to errors caused by intersymbol interference (ISI). ISI is a common impairment introduced by the communication channel. To obtain reasonable bandwidth efficiency, the channel bandwidth is usually selected to be comparable to the channel (modulation) symbol rate. As a result, the channel impulse response must span more than one channel symbol. Hence, in addition to the component of the desired symbol, the sampled received signal usually contains contributions from multiple channel data symbols adjacent to the desired symbol. The interference caused by the adjacent symbols to the desired data symbol is called ISI. Multipath of a communication channel also introduces ISI.
If the aliased frequency spectrum of the received signal sampled at the symbol interval is a constant, ISI in the sampled received signal will be eliminated. Thus, one method to correct ISI is passing the received signal through a linear filter such that the sampled signal spectrum becomes a constant. Such a filter is conventionally called a linear equalizer. Methods known in the art for correcting ISI are known as equalization techniques. Well known equalizer techniques include the linear equalizer, decision feedback equalizer (DFE), and maximum likelihood sequence estimation (MLSE) equalizer.
It is well known that an optimal receiver front end that maximizes the received signal-to-noise ratio is a matched filter (MF) front end. If there is no ISI at the output of the matched filter, the receiver can achieve the optimum performance, called MF bound, over channels with additive Gaussian noise. Unfortunately, a matched filter usually also introduces ISI. As a result, an equalizer is usually needed to follow the MF front-end. If an equalizer is needed, the receiver will always have an inferior performance compared to the MF bound.
If the previous and future symbols of the current desired symbol are known, it is possible to attain the MF bound performance by subtracting out the ISI caused by these symbols. This technique is called ISI cancellation. Unfortunately, these symbols are usually not known and the ISI cancellation can only be implemented by using the estimates of these symbols. Thus, conventional ISI cancellation techniques are usually far from optimal, and even inferior to other equalization techniques.
There is an ongoing drive in the communications industry to continually improve coding gains. It has been found that combined maximum a posteriori (MAP) algorithms and turbo decoding outperforms ISI cancellation equalization techniques. However, the combined MAP and turbo decoding approach of improving coding gains is very complex, with the complexity of implementation increasing exponentially in relation to the number of channel taps, and according to the configuration of the channel symbol constellation.
It would be advantageous to attain the performance of combined MAP and turbo decoding techniques in a more simply realized manner by optimizing ISI cancellation techniques. ISI cancellation can be optimized by combining ISI cancellation with turbo decoding. Thus, there is a need for a reduced complexity combined turbo decoding and ISI cancellation method of improving communication channel coding gains, which can be simply realized.

Method and apparatus for combined soft-decision based interference cancellation and decoding


A host system used in combination with a driving apparatus for recording information on an information recording medium and reading information recorded on the information recording medium. The host system includes an instruction generation section for generating an instruction including designation information designating an operation type of an operation to be performed by the driving apparatus, and advanced notice information indicating whether the operation type of an operation immediately subsequent to the operation designated by the designation information is the same as the operation type of the operation designated by the designation information; and an output section for outputting the instruction to the driving apparatus. The operation type is either one of a recording operation of recording information on the information recording medium or a reading operation of reading information recorded on the information recording medium.

1. Field of the Invention
The present invention relates to a host system and a driving apparatus included in an information recording and reproduction apparatus in which the driving apparatus records information on an information recording medium and reads information recorded on an information recording medium, and the host system outputs an instruction to the driving apparatus; an information recording and reading method for the host system; and information recording and reading method for the driving apparatus. In particular, the present invention relates to a host system and a driving apparatus for shortening a recording processing time period required for recording information on the information recording medium and a reading processing time period required for reading information from the information recording medium; an information recording and reading method for the host system; and an information recording and reading method for the driving apparatus.
2. Description of the Related Art
Information recording and reproduction apparatuses capable of recording information and reproducing recorded information are well known. An information recording and reproduction apparatus includes a driving apparatus for recording information on an information recording medium and reading information recorded on the information recording medium, and a host system for outputting an instruction to the driving apparatus. The host system outputs a command, to the driving apparatus, including an instruction for recording information on an information recording medium or an instruction for reading information recorded on the information recording medium for the purpose of reproducing the information.
FIG. 14 schematically shows a conventional information recording and reproduction apparatus 1400. The information recording and reproduction apparatus 1400 includes a host system 1410 and a driving apparatus 1420. The host system 1410 is connected to the driving apparatus 1420 through a connection bus 1430.
The host system 1410 includes a user input section 1442 for receiving an input from a user, an information input section 1444 for receiving information to be recorded on an information recording medium 1470 included in the driving apparatus 1420 from an external device, an instruction generation section 1446 for generating an instruction designating a type of operation to be performed by the driving apparatus 1420, an input/output section 1448 for outputting information to the driving apparatus 1420 and receiving information from the driving apparatus 1420, and a reproduction section 1456 for reproducing information. The input/output section 1448 includes an output section 1450 for outputting information to the driving apparatus 1420 and an input section 1452 for receiving information from the driving apparatus 1420.
The driving apparatus 1420 includes an input/output section 1466 for receiving information from the host system 1410 and outputting information to the host system 1410, and a recording and reading section 1468 for recording information on the information recording medium 1470 and reading information recorded on the information recording medium 1470. The input/output section 1466 includes an output section 1462 for outputting information to the host system 1410 and an input section 1464 for receiving information from the host system 1410.
The conventional information recording and reproduction apparatus 1400 operates as follows.
When the user needs information to be recorded, the user instructs the user input section 1442 to record the information on the information recording medium 1470. Based on the instruction from the user input section 1442, the instruction generation section 1446 generates an instruction designating the type of operation to be performed by the driving apparatus 1420, i.e., an operation of recording the information on the information recording medium 1470. The output section 1450 outputs a command including the instruction generated by the instruction generation section 1446 to the driving apparatus 1420.
When the user needs information recorded on the information recording medium 1470 to be reproduced, the user instructs the user input section 1442 to reproduce the information recorded on the information recording medium 1470. Based on the instruction from the user input section 1442, the instruction generation section 1446 generates an instruction designating the type of operation to be performed by the driving apparatus 1420, i.e., an operation of reading the information recorded on the information recording medium 1470. The output section 1450 outputs a command including the instruction generated by the instruction generation section 1446 to the driving apparatus 1420. The recording and reading section 1468 of the driving apparatus 1420 reads the information recorded on the information recording medium 1470 based on an instruction from the host system 1410. The input section 1452 of the host system 1410 receives the information read by the driving apparatus 1420 and the reproduction section 1456 reproduces the information.
FIG. 15 shows a flowchart 1500 illustrating an operation of the driving apparatus 1420 of the conventional information recording and reproduction apparatus 1400. The above-described operation of the information recording and reproduction apparatus 1400 will be described with reference to the flowchart 1500.
In step 1502, the input section 1464 of the driving apparatus 1420 receives a command which is output from the output section 1450 of the host system 1410 and interprets the command. The command includes an instruction designating the type of operation to be performed by the recording and reading section 1468 of the driving apparatus 1420, i.e., an operation of recording information on the information recording medium 1470 or an operation of reading information from the information recording medium 1470.
In step 1504, the recording and reading section 1468 starts positioning for the operation designated by the instruction. Positioning is conducted for preparing the recording and reading section 1468 for performing the operation designated by the instruction. When, for example, the type of operation designated by the instruction is for recording information on the information recording medium 1470, the recording and reading section 1468 performs positioning for recording the information at a prescribed address of the information recording medium 1470. When the type of operation designated by the instruction is for reading information recorded on the recording medium 1470, the recording and reading section 1468 performs positioning for reading the information from a prescribed address of the information recording medium 1470.
After the positioning is finished, in step 1506, the recording and reading section 1468 performs the operation designated by the instruction. When the type of operation designated by the instruction is for recording information on the information recording medium 1470, the recording and reading section 1468 records the information at the prescribed address of the information recording medium 1470. When the type of operation designated by the instruction is for reading information recorded on the recording medium 1470, the recording and reading section 1468 reads the information from the prescribed address of the information recording medium 1470.
After the operation designated by the instruction is finished, in step 1508, the output section 1462 of the driving apparatus 1420 outputs a notification indicating that the operation designated by the instruction is completed to the host system 1410 through the connection bus 1430.
The host system 1410 receives the notification indicating that the operation designated by the instruction is completed from the driving apparatus 1420 and, when necessary, outputs the next instruction to the driving apparatus 1420.
In this specification, the term "operation processing" is defined to include the step of interpreting a command including an instruction from the host system, the step of performing the positioning for the operation designated by the instruction, the step of performing the operation designated by the instruction, and the step of outputting a notification indicating the operation designated by the instruction is completed. The term "reading processing" is defined to include the step of interpreting a command including an instruction from the host system for reading information, the step of performing the positioning for the reading operation, the step of performing the reading operation, and the step of outputting a notification indicating the reading operation is completed. The term "recording processing" is defined to include the step of interpreting a command including an instruction from the host system for recording information, the step of performing the positioning for the recording operation, the step of performing the recording operation, and the step of outputting a notification indicating the recording operation is completed.
The conventional information recording and reproduction apparatus 1400 was developed with an assumption that a recording operation of information and a reading operation of information are performed at different times.
Recently, however, information recording and reproduction apparatuses are required to perform a recording operation of information and a reading operation of information concurrently, so that the user can reproduce one program while recording another program, or the user can record one program while reproduce a part of the same program which was broadcast several minutes before.
The recording and reading section 1468 of the driving apparatus 1420 of the conventional information recording and reproduction apparatus 1400 shown in FIG. 14 cannot record information on the information recording medium 1470 and read information recorded on the information recording medium 1470 concurrently. Therefore, when concurrent recording and reproduction of information is required, the recording and reading section 1468 alternately record information on the information recording medium 1470 and read information recorded on the information recording medium 1470.
FIG. 16 shows a flowchart 1600 illustrating an operation of the driving apparatus 1420 of the information recording and reproduction apparatus 1400 performing a process of recording information, reading information, and then recording another piece of information.
When concurrent recording and reproduction of information is requested, the output section 1450 of the host system 1410 sequentially outputs, to the driving apparatus 1420, a first command including an instruction for performing first recording processing 1610 (a first operation), a second command including an instruction for performing reading processing 1620 (a second operation) and a third command including an instruction for performing second recording processing 1630 (a third operation).
First recording processing 1610 is started as the first operation.
With reference to FIG. 16, in step 1612 of the first recording processing 1610, the input section 1464 of the driving apparatus 1420 receives the first command from the output section 1450 of the host system 1410 and interprets the command. The first command includes the instruction for performing the first recording processing 1610.
In step 1614, the recording and reading section 1468 of the driving apparatus 1420 performs positioning for recording the information on the information recording medium 1470.
After the positioning is finished, in step 1616, the recording and reading section 1468 records the information on the information recording medium 1470.
After the recording and reading section 1468 records the information on the information recording medium 1470, in step 1618, the output section 1462 of the driving apparatus 1420 outputs a notification indicating that the recording operation is completed to the host system 1410 through the connection bus 1430. At this point, the first recording processing 1610 is completed.
Then, the reading processing 1620 is started as the second operation.
In step 1622 of the reading processing 1620, the input section 1464 of the driving apparatus 1420 receives the second command from the output section 1450 of the host system 1410 and interprets the command. The second command includes the instruction for performing the reading processing 1620.
In step 1624, the recording and reading section 1468 of the driving apparatus 1420 performs positioning for reading the information recorded on the information recording medium 1470.
After the positioning is finished, in step 1626, the recording and reading section 1468 reads the information recorded on the information recording medium 1470.
After the recording and reading section 1468 reads the information recorded on the information recording medium 1470, in step 1628, the output section 1462 of the driving apparatus 1420 outputs a notification indicating that the reading operation is completed to the host system 1410 through the connection bus 1430. At this point, the reading processing 1620 is completed.
Then, the second recording processing 1630 is started as the third operation.
In step 1632 of the recording processing 1630, the input section 1464 of the driving apparatus 1420 receives the third command from the output section 1450 of the host system 1410 and interprets the command. The third command includes the instruction for performing the second recording processing 1630.
In step 1634, the recording and reading section 1468 of the driving apparatus 1420 performs positioning for recording the information recorded on the information recording medium 1470.
After the positioning is finished, in step 1636, the recording and reading section 1468 records the information on the information recording medium 1470.
After the recording and reading section 1468 records the information on the information recording medium 1470, in step 1638, the output section 1462 of the driving apparatus 1420 outputs a notification indicating that the recording operation is completed to the host system 1410 through the connection bus 1430. At this point, the second recording processing 1630 is completed.
As shown in FIG. 16, the information recording and reproduction apparatus 1400 performs the operation processing for recording or reading information in repetition.
The speed of recording processing and reproduction processing can be increased by shortening the operation processing time. In that case, concurrent recording and reproduction of even high bit rate (high density) information can be property performed.

Host system, driving apparatus, information recording and reading method for the host system, and information recording and reading method for the driving apparatus

Matsushita Electric Industrial Co., Ltd.


A load detecting sensor includes a first member, a second member, and an optical fiber. The first member has a groove having a bottom portion and a column portion which defines the groove. The second member covers the groove of the first member so that a surrounded space is formed. The optical fiber is arranged in the surrounded space. At least one of the first member and the second member is made of an elastic body. The surrounded space is deformable when load is applied to at least one of the first and the second members. When load is applied to at least one of the first and the second members, the deformation of the optical fiber is caused following the deformation of the surrounded space. Hereby, the load detecting sensor, which can decrease the manufacturing cost and increase the detecting sensitivity by the optical fiber, can be obtained.

Conventional collision detecting sensors are disclosed in JP-A-2006-105973 (Reference 1) corresponding to EP 1795878A1 and in JP-A-2005-249680 (Reference 2) corresponding to US 2005/0193830 A1. The collision detecting sensor of Reference 1 includes an optical fiber and a corrugated plate, which are covered by a mold rubber. The collision detecting sensor of Reference 2 includes a concave holding member, a corrugated member arranged at the bottom of the holding member, an optical fiber arranged inside the concave holding member, and a counterpart member arranged so as to space from the holding member and the optical fiber at the initial state.
However, the sensor of Reference 1 needs to reshape the mold rubber by the press work after the mold rubber is extruded. If the mold rubber is pressed with the optical fiber is set in advance, the optical fiber may be broken. Therefore, for example, the mold rubber is pressed with a metal rod is set in advance, and after the metal rod is removed, the optical fiber needs to be inserted into a hole in which the metal rod was filled. Therefore, the manufacturing cost becomes high in the constitution that the optical fiber is covered by the mold rubber.
On the other hand, the sensor of Reference 2 can resolve the problem of the manufacturing cost since a mold rubber such as Reference 1 is not used. As described in Reference 2, the optical fiber is easily broken. According to Reference 2, when the excessive impact force is generated, since the impact is not transmitted to the optical fiber, the breakage of the optical fiber can be avoided. However, even though the impact force is small, when the optical fiber is pressed by the highly-rigid member directly, the optical fiber may be broken. To solve this problem, an outer surface of the optical fiber is covered by an elastic member such as a rubber. However, by the elastic force of the rubber which is attached to the outer surface of the optical fiber, the pressing force by the corrugated member is likely to be decreased and the sensitivity of the optical fiber is decreased.

Load detecting sensor and collision detecting sensor using the same


Provided is a storage system in which a transaction of a database is quiesced, a pair of a first volume and a second volume is split so as to make settings to allow an access to be made only to the database in the first volume, the transaction is then released from the quiescent state, a sparse space is specified in the database stored in the second volume, only the specified sparse space in the second volume is partially reorganized, and the contents of the partially reorganized second volume are copied to the first volume such that the first volume and the second volume are resynchronized with each other to form the pair again.

This invention relates to a storage system for operating a database, in particular, a reorganization method of a database.
Conventionally, a database management system (DBMS) for managing a database is designed to increase database responsiveness. A storage area of a storage system or the like is designed such that a storage area of a database is not changed frequently, so as to avoid complex management as much as possible. Therefore, in the storage area of a database, "fragment" is gradually caused with the elapse of operating time. The term "fragment" means generation of a fragmented space, an uncollected area, or imbalance in a space management structure. The fragment in the storage area degrades database responsiveness (I/O performance or search performance) leading to an inducement for unexpected use of the storage area.
In order to eliminate the fragment in the storage area, DBMS is generally provided with dedicated software. The software eliminates the fragmentation, collects the uncollected area, and balances the space management structure on the storage area of the database, so as to change the storage area into an ideal state without any fragment. This processing is called "reorganization".
An administrator of the DBMS is required to regularly implement the reorganization using reorganization software so as to eliminate the degradation of database responsiveness and the unexpected use of the storage area.
As regards such reorganization, there has been known a storage system, for example, in which data in a reorganization source is transferred to a reorganization destination storage system so as to reorganize a database in the reorganization destination. After the data has been reorganized in the reorganization destination, update occurred in the reorganization source during the reorganization is applied to the reorganization destination so as to switch the data to be used by the DBMS to the reorganization destination (for example, "Online database reorganization function", issued by Hitachi Ltd., searched on Apr. 10, 2005, on the Internet, which can be located with the listing hitachi.co.jp/Prod/comp/soft1/4vsp/products/dbr.html>).
Moreover, the amount of data has been increasing in databases in recent years. Accordingly, the reorganization of all data needs a long processing time. Therefore, there has been known a storage system in which reorganization is implemented only for the data in a storage area designated by an administrator or the like (for example, "IBS Parallel Reorganization", issued by IBM, searched on Apr. 10, 2005, on the Internet under the listing of 6.ibm.com/jp/domino02/NewAIS/aisextr.nsf/ByLetterNO/DBA04099?OpenDocument&ExpandSection=1>). In other words, data is divided to be stored into a plurality of storage areas, and only the data in a storage area designated by an administrator or the like is reorganized.

Reorganization method of database and a database reorganization system


Scrolling of a large number of list items can be supported without degradation in performance. Instead of continually moving list items into an actively laid out representation of the list items, list items can be moved in and out of the actively laid out representation as scrolling progresses. Management of the actively laid out representation can be performed transparently to a user to maintain the impression that the total list is present. List items can be grouped into page units, which can be managed to keep a constant number of page units present in the actively laid out representation. Further enhancements can be accomplished by storing some list items remotely.

Lists of information are pervasive in modern computing. Such lists can present information for any of a variety of reasons related to business computing, social networking, or the like. And, given the increasing availability of storage space and computing power, the size of such lists can grow to large proportions. For example, it is not unusual to have a list with thousands, hundreds of thousands, or even more items. While storing such lists is typically not a problem, presenting them is.
It is well known to display only part of a list and allow a user to scroll within the list to see additional content. However, the mechanisms for doing so were typically not designed to handle very large lists. For example, in a web scenario, items on a web page are typically stored as part of a Document Object Model ("DOM"). Because recurring processing is performed on items the DOM, if the DOM contains a large number of items, resources can be consumed to the point where presentation of the list becomes nonresponsive, slow, or freezes. There is therefore room for improvement.


An optical disc drive apparatus includes: a laser beam source; a collector device disposed as facing a disc that can record a signal, which collects a laser beam emitted from the laser beam source onto the disc; a record processing module which records the signal on the disc through the collector device while modulating laser power of the laser beam source; a reflecting light level detecting module which receives the reflecting light when the signal is recorded and detects a level of the reflecting light; a laser power control module which controls the laser power when the signal is recorded based on the detected level of the reflecting light; a tilt control module which controls a tilt angle between the disc and the collector device based on the detected level of the reflecting light; and a switching module which switches between control of the laser power and the tilt angle.

1. Field of the Invention
The present invention relates to an optical disc drive apparatus which can record a signal, and a signal recording method of the same.
2. Description of the Related Art
In recent years, writable optical discs such as CD±R, DVD±R, DVD±RW, and Blu-ray disc are commercially available. In an optical disc apparatus which can meet these optical discs, for example, there is an optical disc apparatus (for example, see Patent Reference 1) which sets a skew target value based on the signal level of an RF playback signal acquired in signal recording to perform skew control (or, it is referred to as tilt control, but hereinafter, it is referred to as tilt because they have the same meanings). However, the RF signal level (the level of a light reflecting from a pit) in the section for detection during recording is varied not only by the change in the tilt angle but also by irregularities in a recording film and temperature change. More specifically, even though the disc is written at the same recording power, the pit is not formed in the same shape because of irregularities in the recording film and temperature change.
In order to solve such problems, under present circumstances, a technique is generally used which is called running OPC (Optimum Power. Control) (hereinafter, it is referred to as ROPC) (for example, see Patent Reference 2). In an ROPC system, the laser recording power is controlled in real time by monitoring the level of a reflecting light so that the level of the reflecting light is made constant. More specifically, for example, suppose a disc is written at a certain level of recording power, or a certain level of multi-pulse power. In the midway of the process, when it is detected that the level of the reflecting light is dropped, which is caused by irregularities in the recording film, for example, the ROPC system performs control so that the recording power is reduced because the pit shape is too deep.
Patent Reference 1: JP-A-2000-331364 (Paragraph [0054] and FIG. 4)
Patent Reference 2: JP-A-2002-288831 (Paragraph [0008])

Optical disc drive apparatus and signal recording method


An air flow channel is used to direct cooling air towards a lamp reflector. The air flow channel has an outer housing and a guider. The outer housing is positioned at the outlet of blower, which is designed to dissipate heat from the lamp reflector. The guider, which is mounted at the side of the outer housing, has an upper slanted surface, a lower slanted surface and a side slanted surface. The air flow is divided into three individual air flows towards the lamp reflector by means of the three slanted surfaces.

1. Field of Invention
The invention relates to a cooling device and, in particular, to an air flow channel.
2. Description of the Prior Art
FIG. 1 shows the cooling method for a conventional projector lamp. Normally, a blower 800 directly blows cooling air into the lamp reflector 700, taking away heat generated by the projector lamp 500. The cooling places of the projector lamp 500 are mainly the high-temperature points above and below the filament 510, the soldering point 520, and the end points 530. Each high-temperature point has to be controlled within a certain temperature range. Aside from the projector lamp 500, the lamp reflector 700 has to be cooled below a predetermined temperature in order to prevent the lamp reflector from breaking. Using the conventional cooling method on the projector lamp 500, the cooling air has a directly impact on the projector lamp 500 instead of cooling each of the high-temperature points according to the required temperature ranges. Moreover, the cooling air first flows by the end point 530, the soldering point 520, and the filament 510 and absorbs their heat before reaching the bottom of the lamp reflector 700. However, these high-temperature points have temperatures higher than the bottom of the lamp reflector 700. The cooling air after absorbing heat from them is very difficult to further cool down the bottom of the lamp reflector 700. If one solves the problem by increasing the fan speed, the temperatures are those high-temperature points will be lowered too much out of the required ranges. This method of first cooling down the high-temperature points with higher temperatures before cooling down the lamp reflector has the drawback that when the temperature of the lamp reflector becomes too high, adjusting the fan speed to lower the temperature of the lamp reflector will render the temperature of the filament out of the specific range. This makes the temperature control very difficult.
As described, the prior art results in non-uniform cooling on different parts of the projector lamp 500 and the lamp reflector 700 or cannot cool the system in such a way that the projector lamp 500 and the lamp reflector 700 fall right within the desired temperature ranges. These effects will affect the performance and lifetime of the projector lamp and the lamp reflector. Thus, it is desirable to provide a better cooling system.


A phased-array antenna having either a corporate or series feed network advantageously includes a phase-shifter array comprised of mechanical phase shifters for beam steering. In some embodiments, the phase-shifter array includes a plurality of phase-shifting slabs each of which includes a phase-shifting member advantageously comprised of a dielectric material. When placed in electromagnetic fields generated by signals propagating through different regions of a transmission line, the phase-shifting members affect the phase of such signals. In some embodiments, the plurality of phase-shifting slabs are mechanically linked by a rigid linkage that is driven by a single driving mechanism. In those embodiments, the phase-shifting slabs and incorporated phase-shifting members in the phase-shifter array are moved in unison, relative to the transmission line, causing a shift in the relative phases of a multiplicity of signals, thereby steering the antenna beam. Each phase-shifting slab in the phase-shifter array also advantageously incorporates at least one impedance-matching member that decreases or eliminates a step change in impedance between air-suspended and dielectric-loaded regions of a transmission line over the full phase-shifting range of the phase-shifting members. Due the reduced incidence of impedance mismatch, phase shifters used in conjunction with the present antenna may be comprised of materials having a relatively high dielectric constant. Using relatively high-dielectric-constant materials results in relatively small phase shifters for a given phase shifting range, or a relatively large phase-shifting range for a given phase shifter size. The phase-shifter array is advantageously readily compatible with flat-panel antenna arrays with little or no modification required to the feed network due to the phase shifter array.

There has been explosive growth in the area of wireless communications. A few years ago, the sight of a person speaking into a cellular phone was a curiosity; now it is commonplace. Communication via cellular phones is supported by wireless telecommunications systems. Such systems service a particular geographic area that is partitioned into a number of spatially-distinct areas called "cells." Each cell usually has an irregular shape (though idealized as a hexagon) that depends on terrain topography. Typically, each cell contains a base station, which includes, among other equipment, radios and antennas that the base station uses to communicate with the wireless terminals (e.g., cellular phones) in that cell.
The antenna used for transmitting signals from a base station is typically a linear phased-array antenna. A phased-array antenna is a directive antenna having several individual, suitably-spaced radiating antennas, or elements. The response of each radiating element is a function of the specific phase and amplitude of a signal applied to the element. The phased array generates a radiation pattern ("beam") characterized by a main lobe and side lobes that is determined by the collective action of all the radiating elements in the array.
It may be desirable, at times, to adjust the geographic coverage of a particular base station. This can be accomplished changing the azimuth ("beam steering") or elevation ("beam tilting") or both (henceforth "beam steering"), of the beam generated by a base station's transmit antenna.
The beam generated by a linear phased-array antenna can be tilted by mechanically rotating the entire antenna array, or by employing a progressive element-to-element phase shift. The two different approaches are not equivalent in terms of their effect on an antenna's radiation pattern. Down tilting via progressive phase shift results in a decrease in peak gain efficiency while the azimuth radiation pattern stays the same. On the other hand, mechanical down tilting can significantly distort the azimuth radiation pattern when projected on the ground-level coverage zone within a cell. Moreover, while progressive phase shifting provides the ability to beam "shape," mechanical down tilting does not. For the foregoing reasons, it is generally preferable to use phase shifting rather than mechanical down tilting.
Progressive phase shift can be accomplished using phase shifters. Most conventional phase shifters suffer from various drawbacks that makes implementation into phase arrays problematic. For example, some conventional phase shifters, such as switchable delay lines and ferrites, are large (and expensive). Integrating such large-sized phase shifters into phased-array antennas often requires modification of the feed network. Other conventional phase shifters, such as solid-state hybrid-coupled-diode phase shifters and thin-film ferrites, disadvantageously exhibit substantial nonlinearity. Moreover, solid-state hybrid-coupled-diode phase shifters have high insertion loss requiring that amplifiers be used at the top of a base station tower to increase signal levels. At the high power levels required for transmission, such amplifiers are heavy, big and expensive. While at the lower power levels characterizing "receive" operation, such amplifiers are considerably smaller and less expensive, it is still generally undesirable to have such active RF electronics at the top of a tower. Still other conventional phase shifters, such as "sliding contact shifters," suffer from corrosion and electrical contact problems over time. In one implementation of a sliding-contact phase shifter, coaxial lines "telescope" into or out of one another such that the line length of the phase shifter, and hence the phase imparted thereby, is changed.
Thus, there is a need for a steerable phased-array antenna having a phase-shifter array that avoids the drawbacks of the prior art and is readily implemented into antenna feed networks without substantial modifications thereto due to the size, weight, etc., of the phase-shifting array.

Steerable phased-array antenna with series feed network


This invention provides an image processing apparatus capable of allowing a user to easily confirm the display contents of a bulletin board without reducing operability if the user should confirm a message by the bulletin board function in authentication processing; a method of controlling the same; and a program. To accomplish this, in the image processing apparatus, an authentication processing unit acquires message information from a storage unit. When the message information is acquired, an authentication screen to execute authentication processing is displayed on a display unit together with the message information. If no message information is acquired, the authentication screen to execute authentication processing is displayed on the display unit.

1. Field of the Invention
The present invention relates to an image processing apparatus having a user authentication function and a bulletin board function.
2. Description of the Related Art
An image processing apparatus described in Japanese Patent No. 4124930 supports a bulletin board function of displaying, on a display unit, message information received from outside of the apparatus. Using this function enables the display of a predetermined message on the operation screen and allows the user to be notified of, for example, the timing of maintenance of the image processing apparatus. Some image processing apparatuses support an authentication function of performing user authentication and display a waiting screen for user authentication.
However, the related art has problems, to be described below. In the related art, the bulletin board function and the authentication function are independent functions. When the user is caused to confirm a message by the bulletin board function at the timing of authentication processing, operability is reduced. For example, to display the authentication screen after the bulletin board has been closed, an operation to display the authentication screen before the authentication operation is necessary, resulting in reduced operability. When displaying the bulletin board after authentication processing, too, an operation corresponding to one screen is needed before the normal operation, and again operability is reduced.
User authentication includes, for example, IC card authentication that requires no operation via the display screen. When the user is caused to confirm a message by the bulletin board function at the timing of authentication using an IC card, a possibility for confirming the message on the bulletin board by the user is very low.

Image processing apparatus, method of controlling the same, and storage medium