The present invention is a pod opener having an end effector which:                a. grips and releases a reticle supported above the base of a pod; and        b. while transferring the reticle between the base of the pod and an adjacent IC photolithography tool, reorients the reticle.In one embodiment, the pod opener reorients the reticle by rotating it about a single axis disposed substantially perpendicular to its patterned surface. In another embodiment, the present invention is a pod opener which while transferring the reticle between the base of the pod and an adjacent IC photolithography tool, in addition to effecting rotation substantially perpendicular to a reticle's patterned surface, also turns the reticle over so a patterned surface of the reticle is oriented for proper focus within the IC photolithography tool.

1. Field of the Invention
The present invention relates generally to the technical field of automated tools used for integrated circuit fabrication and, more particularly, to automated reticle handling tools.
2. Description of the Prior Art
Presently, conventional processes for manufacturing integrated circuits ("ICs") include a number of process steps in which a surface of a semiconductor wafer is first coated with a thin layer of a photo-resist material after which the photo-resist material is irradiated with short wavelength light to form a latent image of a pattern in the photo-resist layer. A subsequent processing step develops the latent image thereby leaving patterned photo-resist material on a wafer's surface. In processing a semiconductor wafer to fabricate ICs, the preceding procedure for establishing patterned photo-resist material on a wafer's surface may be repeated dozens of times. The pattern formed in the photo-resist layer on a wafer's surface generally differs for each of the dozens of photo-resist exposures performed during IC fabrication. Thus, fabricating a particular type of IC may require a dozen or more reticles each having a different pattern.
In irradiating photo-resist material, the short wavelength light used in forming the latent image passes first through a reticle before impinging upon the thin layer of photo-resist material. In general, reticles used in IC fabrication are made from a thick, planar, rectangularly or square shaped pieces of glass. The reticle is opaque in those areas of the pattern where the reticle blocks the short wavelength light from impinging upon the thin layer of photo-resist material. A reticle's opaque pattern is usually formed by a layer of patterned metal, e.g. chromium, coated on one surface of the piece of glass forming the reticle.
Because reticles are high precision optical devices, they are comparatively expensive. Presently each individual reticle can cost between $5,000.00 and $30,000.00 depending upon the size of the smallest feature in the pattern to be formed in the photo-resist layer on the wafer's surface. Consequently, a complete set of reticles needed for fabricating a single type of IC may cost several hundred thousand dollars. Correspondingly, the photolithography equipment which receives both the reticle and the wafer for exposing the photo-resist layer to short wavelength light is also comparatively expensive costing several million dollars.
A typical IC factory, commonly referred to as a "fab," may include several different models of photolithography equipment from different manufacturers, or different models of photolithography equipment from the same manufacturer. While these differing models of photolithography equipment will all accept the same reticles used in manufacturing a single type of IC, previously there existed no standard holder for a single reticle or cassette for holding a set of reticles while reticles are automatically loaded into and removed from the photolithography equipment. That is, individual photolithography equipment manufacturers have arbitrarily selected unique configurations for holders and cassettes which carry reticles while reticles are loaded into and removed from photolithography equipment. Thus, worldwide presently there are in daily use in IC fabs reticle holders and cassettes having dozens of different, incompatible configurations.
In an effort to standardize reticle cassettes among the products of various photolithography equipment manufacturers, the Semiconductor Equipment and Materials International ("SEMI") has adopted a standard, i.e. SEMI E100-0302, entitled "Specification for a Reticle SMIF Pod (RSP) Used to Transport and Store 6 Inch or 230 mm Reticles." The SEMI E100-0302 standard is hereby incorporated by reference. As implied by the name of the SEMI standard, the configuration of RSP is an adaptation of a previously existing Standard Mechanical InterFace ("SMIF") pod which is widely used in IC fabs for carrying 8-inch semiconductor wafers during wafer processing. While it appears likely that sometime in the future all photolithography equipment will accept the RSP for holding reticles while individual reticles are automatically loaded into and removed from the photolithography equipment, due to the presently existing large installed base of photolithography equipment such a situation is unlikely to occur in the immediately foreseeable future. Thus, for the foreseeable future a need will continue to exist for automatically moving reticles into and out of uniquely configured photolithography equipment.
Some photolithography tools used in patterning blank reticles accept and deliver cassettes which carry a number of reticles. Some IC fabrication photolithography tools, as contrasted with photolithography tools used in patterning blank reticles, provide storage within the tool for a relatively small inventory of reticles. Other IC fabrication photolithography tools are unable to store any reticles. However, whether an IC fabrication photolithography tool provides or lacks storage for an inventory of reticles, such tools are, in general, configured for receiving or delivering single reticles one at a time.
Because IC fabs store reticles in various differing ways when they are not being used for producing patterned photo-resist material on a wafer's surface, presently reticles are manually delivered to and received from IC fabrication photolithography tools. Manually exchanging reticles with IC fabrication photolithography tools insures that, regardless of how reticles are stored when they are not in use, they will be oriented properly in the tool for patterning photo-resist material on a wafer's surface.
As is well known to those skilled in the art of IC fabrication, contamination must be reduced as much as practicable, or even eliminated if possible, within an IC fab. For example, to reduce reticle contamination they may be stored with their patterned surface facing downward. However, proper focus within a photolithography tool may require reorienting the reticle's patterned surface. Properly designed equipment for automatically transferring reticles into and out of photolithography equipment which is capable of reorienting them can reduce or eliminate a possible source of contamination due to manual handling.
Devices used for exchanging with an IC processing tool cassettes which carry a number of semiconductor wafers have been used routinely for a number of years in IC fabs. U.S. Pat. Nos. 5,984,610 and 6,086,323 ("the '610 and '323 patents"), that are incorporated herein by reference, describe such equipment which is frequently identified by the name "pod opener." Pod openers such as those described in these patents exchange with an IC processing tool a cassette carrying a number of semiconductor wafers that are initially enclosed within a SMIF pod. In general, a pod opener accepts a sealed SMIF pod and then opens the pod to expose any wafer cassette carried therein while constantly maintaining an ultra-clean environment around the cassette. After the pod opener exposes the wafer cassette, a robotic arm having an end effector adapted for gripping the cassette exchanges the cassette with an IC processing tool. In general, the semiconductor wafers are oriented horizontally when the cassette is enclosed within the SMIF pod. For that reason, whenever possible IC processing tools are designed to exchange horizontally oriented, individual semiconductor wafers with the wafer cassette. However, depending upon requirements of particular IC processing tools, as described in U.S. Pat. No. 5,885,045 the robotic arm and end effector included in a pod opener may be adapted for reorienting the cassette so the semiconductor wafers are oriented vertically. However, conventional pod openers are not usually equipped for handling and reorienting individual silicon wafers.

End effector gripper arms having corner grippers which reorient reticle during transfer


Hardware not currently being used is re-oriented to a new purpose. Sensors on a personal communication device monitor the environment around the device. Based on an analysis of that monitoring, an appropriate visual message is shown on an outside display screen of the device. The visual message is targeted toward those around the device rather than to the device's user. In some embodiments, the monitoring devices include a camera and a microphone. Images taken by the camera are analyzed in an attempt to detect persons or objects around the user or to determine where the user is located. Captured speech is analyzed to determine topics of conversation. The results of these analyses are fed into a decision-making process that determines what visual messages would be appropriate. In one embodiment, the visual message is an advertisement.

A trend in personal communication devices (e.g., cellular telephones and personal digital assistants) is to make the devices more capable by adding more hardware. Cameras are common on these devices, as are multiple display screens. GPS receivers are becoming more common. Other devices for monitoring either the environment around the device (e.g., a thermometer) or for monitoring the user of the device (e.g., a heartbeat detector) have been proposed.
Useful as this additional hardware can be in particular situations, much of it is used only rarely. The cost of the hardware is paid for (directly or indirectly) by the user, but the hardware provides only a very limited return on that cost. Ready to perform, this hardware spends most of the time taking up space in the device, adding weight, cost, and operational complexity, and only occasionally providing a service to the device's user.

Displaying a message on a personal communication device


method of comparing a secondary oil recovery process with a tertiary oil recovery process, the secondary oil recovery process and the tertiary oil recovery process being applied to a substantially fluid-saturated porous medium containing an oil phase and an aqueous phase. The method comprising using relaxation time measurements in the calculation of a wettability index modification factor for the oil phase or the aqueous phase, thereby comparing the tertiary oil recovery process with the secondary oil recovery process.

In the oil and gas industry, gaining an understanding of the wettability characteristics or wetting condition of a hydrocarbon-bearing, subsurface formation (a "reservoir") may be particularly advantageous. For instance, this understanding may help in the optimisation of field development, since wettability may have an effect on reserve calculation and/or the dynamic behaviour of a reservoir.
Wettability may be defined as the tendency of one fluid to spread on or adhere to a solid surface in the presence of other immiscible fluids.
Thus, for example, wettability may describe the relative preference of a rock to be covered by a certain phase, e.g. water or oil. For example, a rock may be said to be water-wet if the rock has a much greater affinity for water than for oil. Thus, in the case of a water-wet porous rock containing water and oil phases within its pores, substantially all of the internal surface of the pores would be covered with a layer of water. In this case, the water may be termed the "wetting phase".
Conversely, in the case of an oil-wet porous rock, substantially all of the internal surface of the pores would be covered with a layer of oil. In this case, the oil may be termed the "wetting phase".
Similarly, a porous rock of mixed wettability may contain some pores which are water-wet and some which are oil-wet. Also, some regions of an individual pore may be water-wet, while others are oil-wet.
In practice, it will be appreciated that extreme water-wetness or oil-wetness is rare in oil-bearing reservoirs.
It should be appreciated, however, that for a two-phase fluid within a porous rock, the wetting phase will cover more pore surface area and have a stronger surface affinity with the pore walls than the non-wetting phase.
In fluid systems comprising a gaseous phase, e.g. gas-liquid systems, it may be safely assumed that gas is not the wetting phase.
The wettability of a porous rock will depend on the type of rock and will also be affected by any minerals present within the pores. For instance, clean sandstone or quartz may be extremely water-wet, while most rock formations of oil-bearing reservoirs typically may be of mixed-wettability. For a reservoir, wettability alteration from the original water wetting state to a mixed wetting state may have occurred after crude oil migrated into a reservoir trap and reduced the water saturation of the reservoir down to the connate water saturation over geological time. The reservoir wettability depends on crude oil composition, connate water chemistry, and mineralogy of the rock surface, as well as temperature, and pressure and saturation history of the reservoir. The initial fluid saturation distribution in an oil-bearing formation is dependent on the equilibrium between capillary forces and gravity forces at the reservoir scale and at the pore scale. The wetting state can vary with pore and pore-throat geometry. During the oil migration process, gravity is insufficient to overcome the large capillary pressure within micropores, and thus typically micropores remain fully connate water saturated, therefore retaining their original water-wet state. While large pores are often invaded by oil, a connate water film on the rock surfaces of the large pores usually remains. The wettability alteration within the large pores depends on the stability of this water film. In extreme conditions, the water film may be stable and fully coats the surface area of the large pores thereby keeping the oil phase from having direct contact with the pore surface. Thus over geological time, the large pores remain water-wet. Alternatively, the entire surface of the large pores may become coated by the oil phase such that the large pores are oil-wet. Typically, the large pore surfaces are partially in contact with both the water phase and the oil phase, and therefore have mixed-wetting characteristics.
Traditionally, wettability has been characterised in the laboratory using either the Amott or US Bureau of Mines (USBM) indices. However, the methods by which these indices are usually determined are intrusive and are very time consuming. Moreover, they cannot be readily transferred to the field.
It is known that nuclear magnetic resonance (NMR) techniques may be used to ascertain information regarding fluids contained within a porous medium. Advantageously, using NMR techniques offers a non-intrusive means for determining in-situ wettability of fluids in reservoir rocks, i.e., the NMR measurement process does not interfere with the fluid distribution within the pores of the rock. Hence, NMR techniques may be applied to monitor ongoing dynamic processes comprising wettability alteration, such as, ageing and secondary or tertiary oil recovery processes.
Proton (1H) NMR techniques may be particularly well suited for studies of fluids containing water and hydrocarbon phases, e.g. water and oil, within a porous medium.
NMR spectroscopy may be used to measure the spin-lattice (longitudinal) relaxation time (T1) and/or the spin-spin (transverse) relaxation time (T2) of the fluid. For instance, proton (1H) NMR spectroscopy measures the relaxation time for protons within the fluid. From these measurements it may be possible to elucidate certain information concerning the fluid and/or the porous medium.
For instance, core samples may be taken for subsequent analysis using land-based NMR equipment.
Alternatively, NMR logging tools may advantageously be deployed downhole. Such tools typically employ so-called low field spectroscopy.
However, NMR logging tools also suffer from certain drawbacks. For instance, they cannot be used in wellbores or sections thereof which are lined with metal casing. Also, current tools typically can only obtain information in the near-wellbore region, e.g. typically within a radial distance of about 4 inches (10 cm) from the wellbore. It is envisaged, however, that future generations of NMR logging tools may be able to obtain information relating to regions further from the wellbore.
Oil may be produced from a reservoir in a variety of stages, which may be classified as primary, secondary and tertiary stages.
In a primary oil recovery stage, the natural energy of the reservoir is sufficient to produce oil without any assistance. However only around 10 to 15 percent of the original oil in place of a reservoir is recovered during primary recovery.
In some reservoirs, however, the natural reservoir pressure may not be sufficient to drive oil unaided up a production well to the surface. Therefore, it may be necessary to artificially boost oil production. In this regard, it is known that oil production from a reservoir may be assisted by injection of immiscible fluids, such as water or gas, into the reservoir so as to maintain reservoir pressure, and/or to displace oil towards a production well. Injection of such immiscible fluids generally produces about 20 to 40 percent of the original oil in place.
Where the fluid is unmodified, typically seawater or other readily available water, this process may be classified as being a secondary oil recovery process (alternatively a secondary mode process). In general, such a secondary oil recovery process may be referred to as a water flood or water flooding.
Where the fluid has been treated in some way to modify its properties, this process may be classified as being a tertiary oil recovery process. For instance, tertiary recovery processes may include low salinity water flooding in which a source water such as seawater is treated to reduce its salinity prior to injection into the reservoir and processes in which the to-be-injected fluid comprises one or more specially chosen additives, e.g. chemicals and/or microbes. By appropriately modifying the injection fluid, tertiary oil recovery processes may be used to boost oil production from and/or extend the production life of a reservoir. Typically, tertiary oil recovery processes may displace oil from a reservoir which is not displaced by secondary oil recovery processes. Tertiary recovery processes may often be referred to as enhanced oil recovery (EOR) processes. The EOR techniques offer prospects for ultimate recovery of 30 to 60 percent, or more, of original oil in place.
During the production life of a reservoir different methods of oil recovery may be employed. For instance, initially the reservoir may be produced by a primary recovery method. However, after a while, the reservoir pressure may fall and it may become necessary to utilise secondary oil recovery processes. A period of secondary oil recovery may be followed by one of the EOR processes, in order to maximise production from the reservoir. Of course, the person skilled in the art will appreciate that other sequences are possible: for instance, it may be the case that the reservoir is never produced in primary recovery because the natural reservoir pressure is not high enough; alternatively or additionally, a period of EOR may be applied just after primary recovery, with this EOR process being referred to as a secondary mode EOR process. In contrast, an EOR process may be carried out after the completion of a secondary oil recovery process, with this EOR process being referred to as a tertiary mode EOR process.

BP EXPLORATION OPERATING COMPANY LIMITED


A position measurement apparatus for measuring a position of a mark includes an image capturing unit, a calculating unit which obtains variation in image data captured by the image capturing unit, and a setting unit which sets a parameter concerning a light receiving amount of the image capturing unit based on variations respectively obtained by the calculating unit with respect to a plurality of image data acquired by the image capturing unit at different light receiving amounts.

In an exposure apparatus for semiconductor manufacture, and the like, as a method of detecting the position of the areas of a wafer to be exposed, there is one that discharges light having a predetermined wavelength using an alignment optical system and utilizes the results of the photoelectric conversion of the light reflected from an alignment mark for position detection. Below, a brief description is given of a conventional example of a semiconductor manufacturing exposure apparatus using this technology.
In the exposure apparatus shown in FIG. 5, R designates an original (hereinafter, also called a reticle), on which an electronic circuit pattern is formed, W designates a wafer that is an exposure substrate, and reference numeral 1 designates a projection optical system. In addition, S designates an alignment optical system, 2 designates an alignment illumination device, 3 designates a beam splitter, 4 and 5 designate image formation optical systems, 6 designates an image capturing unit, 7 designates an A/D conversion unit, 8 designates an integrating device, and 9 designates a position detecting unit. Reference numeral 10 designates a wavelength switching unit, 11 designates an XY stage movable in two dimensions, and 13 designates a stage control unit. The stage control unit 13 can position the XY stage at a predetermined position based on detection results of the position detecting unit 9. Reference numeral 14 designates an exposure illumination light source, which illuminates the reticle R. Here, in FIG. 5, although only the alignment optical system S that detects position in the X direction is shown, it is to be understood that, similarly, an alignment optical system for detecting position along the Y axis (a direction perpendicular to the surface of the paper on which the drawing is made) is also provided on the exposure apparatus. The exposure apparatus used for semiconductor manufacture shown in FIG. 5, after relative alignment of the reticle R and the wafer W, emits exposure light from the exposure illumination light source 14 and, through the projection optical system 1, projection-exposes the electronic circuit pattern formed on the reticle R onto the wafer placed on the XY stage 11.
Next, a description is given of a position detecting method of the above-described exposure apparatus. As an initial matter, first, the position of the XY stage is adjusted so that alignment marks WM on the wafer W can be seen in an image capturing screen of the image capturing unit 6. Next, non-exposure light is emitted from the alignment illumination device 2 and the wavelength switched by the wavelength switching unit. A light flux whose wavelength has been switched illuminates the alignment marks WM through the image formation optical system 4 and the beam splitter 3. The light flux reflected from the illuminated alignment marks WM passes through the beam splitter 3 and the image formation optical system 5 and forms an image of the alignment marks obtained from the reflection in an observation area (WP) on the image capturing surface of the image capturing device 6 (FIG. 2E). The image capturing device 6 photoelectrically converts the image of the alignment marks.
Thereafter, an output from the image capturing device 6 is converted into a two-dimensional digital sequence at the A/D conversion device 7. The integrating device 8 converts the two-dimensional signal that is the output of the A/D conversion device 7 into a one-dimensional digital signal sequence S1(x). After conversion to the one-dimensional digital signal sequence S1(x), the position detecting unit 9 detects the positions of the alignment marks WM.
The creation of the one-dimensional digital signal sequence S1(x) by the integrating device 8 necessitates (1) the photoelectric conversion in the image capturing unit 6, and the A/D conversion in the A/D conversion unit 7 must be carried out within the respective dynamic ranges, and (2) that the photodetection levels be sufficient for detection of the positions of the alignment marks WM by the image capturing unit 6. If these two conditions are satisfied, it is possible to carry out detection of the positions of the alignment marks accurately.
A position detection technique that can determined whether or not the image capture detection level is within a predetermined range, as well as that can enable image capturing of a mark at an appropriate photodetection level based on the results of that determination, is disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2003-092247.
However, in recent years, the density of semiconductors typified by the DRAM has continued to increase, as has the degree of accuracy required of alignment mark position detection. In order to adjust the photodetection level of the image capturing unit 6, one method adjusts the intensity of the illumination of the alignment illumination device using an ND filter, or the like, not shown, and another method adjusts the image capturing unit 6 photodetection time (that is, the charge storage time of a photoelectric conversion device such as a CCD). However, in a case in which a primary digital sequence S(x) is generated to obtain the S/N ratio of such a sequence S(x) after A/D conversion of the results of photoelectric conversion by the image capturing unit 6, the effects of optical noise caused by flickering of the light source of the alignment illumination device 2 and electrical noise from the image capturing unit 6 and the A/D conversion unit 7 mean that, even if adjustment is made so that the photodetection level is the same, the S/N ratio of the one-dimensional digital signal sequence S(x) varies due to the photodetection level or to the combination of the illumination intensity and the photodetection time. This means that, even with the same photodetection level, the alignment mark position detection accuracy fluctuates, and consequently, in some cases, there is a risk that the alignment mark position detection accuracy deteriorates, and it is possible that there are instances in which simply keeping the photodetection level within a predetermined tolerance is inadequate.


A method of forming a light sensor array includes tuning a resistance level of a plurality of resistors. The resistors are included in a light sensor array for use with a positron emissision tomography (PET) scanner system. The light sensor array includes detection circuits that each includes one of the resistors connected in series with an avalanche photodiode.

A variety of devices make use of use of a light sensor array. Examples of these devices include medical imaging devices such as positron emissision tomography (PET) scanners. The light sensor arrays employed in PET scanners has a plurality of pixels. Each of the pixels includes one or more detection circuits that each has a resistor connected in series with an avalanche photodiode. During operation of the device, each detection circuit provides an output signal in response to the avalanche photodiode in that detection circuit receiving a photon. As a result, the output signals from the detection circuits in a pixel can be used to determine the number of photons incident on the avalanche photodiodes in the pixel.
The resistors in the detection circuits of a single device can have a wide range of resistance values. However, the output signal provided by a detection circuit is dependent on the resistor in that detection circuit. Accordingly, the variation in resistor values can cause the output signals from different detection circuits to have a wide range of values. The variation in these output signals can result in an inaccurate determination in the number of photons that are received by the photodiodes in a pixel.
As a result, there is a need for improved light sensor arrays.


A first bypass pipe has one end connected to a main pipe extending from a compressor to an indoor heat exchanger, and its other end branched off into parts that are each connected to the main pipe on an inlet side of an outdoor heat exchanger, and a second bypass pipe has one end connected to an injection port communicating with the compression chamber of the compressor in which compression is taking place and its other end branched off into parts that are each connected to the main pipe on an outlet side of the outdoor heat exchangers. During a defrosting operation that removes frost on the outdoor heat exchangers, a part of the refrigerant discharged from the compressor is supplied from the first bypass pipe to the outdoor heat exchanger to be defrosted, and is then passed through the second bypass pipe and injected from the injection port of the compressor.

In heat pumps according to the related art, to remove frost n on an outdoor heat exchanger that serves as an evaporator during a heating operation, a defrosting operation is performed by reversing the refrigeration cycle. However, this defrosting method compromises indoor comfort because heating is stopped during the defrosting operation. Accordingly, as a technology that enables a simultaneous heating operation and defrosting operation, there is a heat pump in which an outdoor heat exchanger is divided into a plurality of parallel heat exchangers with reference to a refrigerant flow diversion path, and a bypass that bypasses a discharge gas from a compressor, and a solenoid opening and closing valve that controls the bypass state are provided in each of those parallel heat exchangers (see, for example, Patent Literature 1). In this heat pump, a part of the refrigerant from the compressor is caused to enter each bypass alternately, and each parallel heat exchanger is defrosted alternately, thereby allowing heating to be performed continuously without reversing the refrigeration cycle.


An apparatus for separating print stream data containing a plurality of primary documents and information concerning associated customers to receive the documents, wherein the apparatus receives customer preference data that allow separation of the print stream data into an electronic primary document print stream and a hard copy primary document print stream. The print stream separator further generates a second output for the customers that are to receive their primary documents by electronic delivery, where this second output contains information regarding which of a plurality of secondary documents the customer should receive with the primary document. The priorities of these secondary documents may be based upon specific customer preference data for the specific customer receiving his or her primary document. Priorities for these secondary documents can also be included in this second output. A method corresponding to this apparatus is also described.

In the development of a digital data delivery system, it is found that an analog to the physical generation of a printed document is advantageous for acceptance of an electronic version of the document for presentation to an end-user such as a customer receiving for instance, a bill from a company with which that customer does business. In many legacy computer systems, mainframe computers are used to generate print stream information in one of a plurality of formats, including the AFP file format. It is thus desirable to be able to use such a file format as the basis for generating electronic document in a digital document delivery system.
A print stream separator according to the present invention receives print stream data from an associated generator of such information, such as a legacy mainframe computer print stream output. Such information in a typical application may contain a plurality of customer bills for presentation to the customers of a particular company. Bill information and accompanying customer account information form at least part of this print stream. Such information in the past would generally be directed to a high speed, high volume printer in a particular file format such as the AFP file format for generation of the customer bills with insertion of one or more hard copy inserts, typically of an advertisement or informational nature. Such inserts are put into the customer""s bill based upon information concerning the identified customer as derived from a customer preference database and with the specific inserts being determined based upon a prioritization in view of information received from the customer preference database so as to maintain a certain weight limit for the hard copy mailing.
The present invention provides a print stream separator which receives the initial print stream data, as well as information from a customer preference database. The print stream separator then determines which documents are to be generated in electronic form and which are to be directed to a high speed, high volume printer, such that the data presented to the high speed, high volume is separate and distinct from the data sent for ultimate presentation and viewing in electronic form. Information within the customer preference file for each customer is the basis upon which a determination is made as to directing the print stream either to the high speed, high volume printer or to an electronic inserter for presentation in electronic form.
If the data is to be presented in electronic form, the print stream separator generates two outputs, a first output representing the customer primary document to be ultimately viewed by the customer, as well as an Electronic Mail Run Data File (EMRDF), which includes a header and fields containing information directed to that customer and the preference of inserts to be generated with the primary document for that customer. Both the electronic document print stream and the EMRDF document record for the customer are then presented to the electronic inserter, which in turn receives job setup data from an associated job setup application module, including information for links associated with particular inserts to be associated with the customer""s primary document. The electronic inserter generates an output print stream in an AFP file format containing the primary document information. The EMRDF file is communicated to the router instruction processor (RIP) and contains information regarding specific links for xe2x80x9cinsertsxe2x80x9d (secondary documents) which are to be associated with the primary document.
As more fully described in co-pending application Ser. No. 09/222,196 entitled System and Method for Presenting and Processing Documents on the Internet, filed on the same date herein, and assigned to the same assignee, the print data stream from the electronic inserter is presented to an interactive bill presentation server (IBPS), under the control of a bill processing server (BPS). The IBPS output is ultimately presented to a customer having access to a computer with an associated web browser so as to allow view of the primary document and the associated inserts. The customer can, after viewing the primary document (which typically would be in the nature of a bill), respond to the primary document (bill) such as to make payment thereof. This response information is processed by the overall digital document delivery system by means of the bill processor server which updates the customer""s account database such as to indicate payment of a bill or the like.

System and method for separating a print stream into an electronic document print stream and a physical document print stream


A light source can have a conversion element disposed at one end of an optical waveguide and a semiconductor light source disposed at the other end. The optical waveguide can include a heat-conducting layer at its end proximate the converter.

A component with a conversion element is known, for example, from WO 97/50132. It includes a semiconductor chip which in operation emits a primary radiation, and a luminescence-based conversion element by which a portion of the primary radiation is converted to light of another wavelength. The resulting visually perceptible radiation from the semiconductor light source is created by the superimposition of the primary radiation and the secondary or converted radiation, making it possible, in particular, to produce light sources that are capable of emitting white light. The radiation conversion produced in the conversion element in this case is based on luminescence or fluorescence.

Light source with conversion element and fiber optics


A method is executable on a Gateway which is capable of communicating with a Machine Device, a User Device and a Manager Device. The method comprise receiving, from the Manager Device, a first request, requesting for status information associated with the Machine Device, after which the Gateway is determining under which conditions to acquire the requested status information, and to send the acquired status information to the Manager Device. Next the Gateway is determining the relevant status information of the Machine Device, based on a response to a second request, requesting for updated data associated with the Machine Device, the second request being provided to the Machine Device from the Used Device, and the response being received from the Machine Device by the Gateway, after which a notification, comprising the determined status information, is provided from the Gateway to the Manager Device.

Constrained Application Protocol (CoAP) is a specialized web transfer protocol designed for handling Machine to Machine (M2M) applications in constrained nodes and constrained networks. CoAP provides a request response based architecture between endpoints, where communication is performed between entities, typically referred to as a CoAP Server and a CoAP Client, respectively, over User Datagram Protocol (UDP).
CoAP is designed to easily work along with Hypertext Transfer Protocol (HTTP) for integration with the current Web, while adding additional features, such as e.g. multicast support, very low overhead and simplicity for constrained environments. More information on CoAP can be found on http://tools.ietf.org/html/draft-ietf-core-coap-18.
One available extension to CoAP enables CoAP clients to observe available resources from CoAP servers, or in other words, CoAP servers are allowed to notify CoAP Clients of available resources, as can be seen in http://tools.ietf.org/html/draft-ietf-core-observe-12. This enables server-initiated communication in constrained networks using CoAP.
Open Mobile Alliance Device management Lightweight (OMA DM LW) is a light and compact device management protocol developed for M2M networks, which includes device management and service enablement for LWM2M enabled devices, as described in Lightweight Machine to Machine Technical Specification, Candidate Version 1.0—10 Dec. 2013, OMA-TS-LightweightM2M-V1_0-20131210-C in section 5.1-5.4. Being designed for constrained networks, OMA DM LW can run over both UDP and SMS bindings. This enables OMA DM LW to be applicable with any type of constrained device or network using CoAP.
The architecture of OMA DM LW is based on a client-server model, including both a LWM2M Server and a LWM2M Client, similar to CoAP. However, in OMA DM LW, the LWM2M Client runs in the constrained device to be controlled, while the LWM2M Server represents a node with some management capability, which may be either a Gateway (GW) or a network node. For typical Internet of Things (IoT) scenarios, it will be commonplace to have multiple clients, a few servers and several nodes acting as relays or proxies, where each of these nodes comprises both a client and a server side. In fact, very much like CoAP, the frontier between Server and Client can be fuzzy, since all LWM2M Clients are most likely also CoAP Servers and most LWM2M Servers should also be CoAP Clients.
OMA DM LW introduces a simple object based resource model for management, inherited from CoAP, to be used between LWM2M Server and LWM2M Client. In this model, each piece of information made available by a LWM2M Client is a Resource and Resources are logically organized into Objects. Hence, an object defines a grouping of Resources, for example Object ID 3 "Device" contains all the Resources used for device related information.
OMA DM LW provides several interfaces towards access objects, among which the "Information Reporting" is provided for error reporting. This interface allows LWM2M Servers to observe resources and to be notified whenever changes occur in a network, (very much following the publish/subscribe paradigm.)
Existing management solutions are usually composed the following entities:                Machine Devices (MDs): Devices, which can be constrained devices, comprising one or more sensors and/or actuators, where the device is running some management Agent (here the LWM2M protocol is used for this purpose) that have to provide information about what the sensors are sensing, as well as report management errors and other relevant issues. Sensors can also run the customary CoAP server to provide users access to readings.        Manager Device: An entity running a management application which is taking care of sending commands, updating firmware and other Objects of the MDs. In real deployments the Manager Device may also contain a LWM2M Server.        Gateway (GW): This entity is arranged between Agents and Manager Device, in case the MD is a constrained device which is not itself capable of providing adequate Internet connectivity. The GW is running a Resource Directory (RD) and possibly a cache of received messages, such as e.g. a Mirror Proxy (MP) towards its MDs. The GW runs some management protocol (LWM2M in this example) towards the Manager Device too. During the registration process of every MD (normally executed when bootstrapping the MD) the MD registers to the RD in the GW.        User: An end user which is capable of requesting for, and receiving the latest measurements of the MDs via a communication device which comprises a CoAP Client.
There are typically multiple Management operations that can be done on a sensor of an MD, such as e.g. upgrading of firmware, changing access control policies, changing security settings and setting alarms. In LWM2M there are specific Objects in each device to represent this type of information. This feature is inherited from CoAP Objects and resources; in fact LWM2M works in pretty much the same way as CoAP. The manager can use GET or PUT messages to retrieve or store information on any of these objects and set notifications by using the Observe command.
Another function that Manager Devices need for managing MDs is to be aware of whether the MDs are connected or not. This is especially true for large IoT deployments. However, just to keep track of the general status of various devices typically requires a lot of message overhead towards the Manager Device.
Despite the fact that both CoAP and LWM2M protocols are extremely similar they are currently not capable of communicating with each other. Management objects are used only for management purposes, while data plane objects, or resources, are only used for data or user plane information. In other words, while measurement information is provided to a CoAP Client, Management reports are provided to a LWM2M Server, which is not an ideal situation. More specifically, LWM2M runs on top of CoAP, where CoAP defines multiple messages and entities, such as e.g. RD and/or MP to facilitate communication with the user. With other protocols, such as e.g. HTTP or Simple Network Management Protocol (SNMP), you normally have a clear differentiation between data plane and control plane, but with CoAP and LWM2M all messages are encapsulated using CoAP.
This would normally mean that all entities using CoAP would be aware of each other and that the protocols would be optimized to send as few messages as possible. This is however not the case here.
Normally CoAP messages will be used for the data plane, e.g. for getting sensor readings, or resource discovery, and LWM2M for management commands, such as e.g. error reports. These two types of messages/commands will be running as different processes in the MDs, namely as user processes and manager processes, respectively.
This means that there will be a lot of overlapping of messages and message overhead. The fact that an MD is awake will for example be advertised twice, once for the user and once for the Manager Device.
When using standard LWM2M, the Manager Device can set a notification to be received when a specific MD is awake. The Manager Device can also poll the objects in an MD to become aware of if it is connected too. However, this is a highly inefficient procedure since every MD has to send one message, saying that it is awake every time it wakes up and, as a consequence, on each such occurrence, the Manager Device will receive one extra message per device. This clearly poses scalability problems, since, as the number of deployed MDs increases, there will be a need to deploy dedicated machines to aggregate and handle management information. It is also not far fetched that in the future management messages will get as large as data messages, which will increase the workload on all involved entities even further.

Periodic management stabilization for internet of things


A rotatable line spool for a fishing reel, the spool including a line-receiving surface defining an axis of rotation for the spool. The surface extends radially outwardly to define an axial boundary for line received on the spool and terminates in the radial direction at a radially outer rim spaced from the axis by a radial distance R. The outer rim extends outward from the line-receiving surface and terminates at a first annular surface spaced axially outward from the line-receiving surface. A flywheel mass extends radially inward from the outer rim and terminates at a radius R2 from the axis in the range of 55% to 85% of R. The mass extends axially outward from the line-receiving surface and terminates at a second annular surface that is spaced axially inward from the first annular surface by an axial distance X in the range of 0%-5% of the radial distance R.

Fishing reels having line spools that rotate as line is paid out are well known. One common form of such reels is known as a baitcast reel and utilizes a line spool that is mounted by roller bearings or bushings to rotate about an axis perpendicular to the length of the fishing rod to which it attaches.
Two desirable features for fishing reels are light weight and long casting ability. A lightweight reel is desirable because it is common for fishing equipment to be hand carried relatively long distances to remote lakes or streams and because it is common for the reel, in combination with a rod, to be held and manipulated for relatively long periods of time while in use. Long casting performance by a reel allows a fisherman to place a lure or bait at a point that is remote from the fisherman's physical location. This allows the fisherman the most options for placement of a lure or bait without having to relocate. Thus, there is a continuing desire for lighter weight and longer casting reels.
While the industry has been successful in providing lightweight reels and in providing reels that have long casting performance, the industry has been relatively unsuccessful in providing a reel that combines both of these desirable features. This is in part because line spools made of a relatively heavy material can provide a long casting performance, but tend to make a reel undesirably heavy; while line spools made from a relatively light material can provide lightweight reels, but tend not to provide long casting performance.


A system and method for providing error correction and detection in a memory system. The memory system includes a plurality of memory devices, and error detection and correction logic. The error detection and correction logic includes instructions for generating an error correction code (ECC) word that includes bits from two more of the memory devices and from different memory device transfers.

This invention relates generally to computer memory, and more particularly to providing error correction and detection in a memory system.
Contemporary high performance computing main memory systems utilize error correction codes (ECCs) to detect and correct occasional, random bit errors.
Historically, for memory devices up through double data rate three (DDR3), most memory errors in a memory subsystem or system could be classified as being related to one or more of memory cell faults (generally affecting a single bit), memory core errors (e.g. word line or bit line errors affecting multiple bits, etc.), I/O errors (affecting one I/O of a device), "chip kills" (affecting all I/Os of a device) or other faults due to interconnect or interface device faults, etc. Bit error rates due solely to I/O transfer failure (e.g. the inability to pass data between the memory device and the device to which the memory device is connected) was almost zero in a properly designed and tuned (e.g. proper driver strengths, terminations, wiring topologies, etc) system.
With the increased data rates that are expected with emerging technologies (such as DDR4 and beyond), the very high data rates are expected to result in a dramatic increase in failure rates due to the inability of the memory device to accurately communicate with the device(s) (e.g., a memory interface device or "MID") to which it is attached, given the reduced timing margins present at the high data rates. These new errors will be caused by several factors such as clock jitter, inter symbol interference (ISI), cross-talk (between adjacent and otherwise nearby lines), etc. Of those listed, clock jitter is expected to be a major component in the increased failure rates, comprising almost half of the total failure rate.
The referenced clock jitter simultaneously affects a multitude of devices which may be transferring data at the same time. As such, the bit error rate (BER) of the devices that are simultaneously transferring data has a much higher correlation than traditional memory device faults (cell, core, etc.), which are generally random in nature. For this reason, the existence of a communication interface fault, at a given point in time in a high speed memory interface, suggests that there is a high probability that one or more other pins that are simultaneously switching may also have an error at the same time. Further compounding the situation is the likelihood that the number of errors (e.g. including at least three or more independent errors) will exceed the capability of contemporary/available ECC schemes which are developed to detect random errors that have almost zero correlation between different pins or different devices.
One method of addressing this concern is through the use of a cyclic redundancy check (CRC) coding, however, this solution requires additional pins (adding cost overhead) and may dramatically affect overall memory performance due to the need to initiate one or more re-try operations until a successful transfer is completed. Unlike ECC, a CRC method does not result in real-time error correction. CRC results in only error detection.
Therefore, it is highly desirable to have an ECC coding structure and method to maximize coverage for multiple bit errors, such as those that will be present with the future high speed memory device interfaces, such that performance and reliability can be maximized with minimal pincount overhead.

System and method for providing error correction and detection in a memory system

International Business Machines Corporation


A flow guiding mechanism with flow channel adjusting function is suitable to a heat dissipating module and an electronic device with an interface card. The flow guiding mechanism includes a supporting component, at least one ventilative structure and a plurality of sheltering components. The interface card is assembled with the supporting component in an assembly direction. The ventilative structure includes a plurality of openings, and the plurality of openings is formed on the supporting component in the assembly direction. The plurality of sheltering components is rotatably disposed on the supporting component. One of the plurality of sheltering components covers a corresponding opening of the plurality of openings while the interface card does not contact the foresaid sheltering component, and the interface card rotates the foresaid sheltering component relative to the supporting component to expose the corresponding opening while the interface card is assembled with the supporting component.

1. Field of the Disclosure
The present disclosure relates to an electronic device having heat dissipating function, and more particularly, to a flow guiding mechanism with flow channel adjusting function and a related heat dissipating module and an electronic device having the flow guiding mechanism.
2. Description of the Prior Art
Operational efficiency and function of an electronic product are increased with the advanced technology, and the electronic product usually has a plurality of expansion cards to conform to application demand. Heat generated by the computer device is accordingly increased since an amount of the expansion card increases and operational efficiency of the expansion card is enhanced. The computer device includes a fan unit disposed inside the casing to generate flow to cool the expansion card, so as to dissipate the heat generated by the computer device and to prevent the computer device from crash. The conventional expansion card includes a full-height expansion card and a half-height expansion card according to its dimension. A height of the half-height expansion card is lower than a height of the full-height expansion card. When the full-height expansion card and the half-height expansion card are arranged on the circuit board in parallel, a gap is formed by height difference, which exists between an upper edge of the half-height expansion card and a lateral side of the full-height expansion card, the flow from the fan unit mostly passes through the gap, and temperature of the half-height expansion card cannot be effectively decreased.
There are several conventional solutions applied to overcome overheat of the half-height expansion card. One of the conventional solutions increases rotation speed of the fan unit to compensate loss of the heat dissipating efficiency because due to flow bypass; however, the foresaid solution has drawbacks of energy waste and expensive cost, and the flow results in turbulence inside the gap to decrease heat dissipating efficiency. Besides, the flow of the fan unit can be applied to flow over a plurality of expansion cards for cooling, the flow still flows over empty space without the expansion card and cannot be applied to other heat generating components.

Flow guiding mechanism and related heat dissipating module and electronic device having the flow guiding mechanism


The invention refers to sea rescue, in particular, to an individual wearable buoyant apparatuses that may be used on beaches, in emergency situations, and on vessels as an individual lifesaver for self-rescue in water, affordable and easy to use for everyone. The rescue wristband consists of elastic inflatable buoyant camera, tightly rolled and compactly packed into a pocket running along the wristband perimeter. System for filling in the chamber is designed as gas generator device emitted the required volume of carbonic gas as result of chemical reaction chemical components safe for human, startup of filling system initiates by hand compression or by excessive pressure of definite depth. If the chamber is filled in with gas, it expands from the pocket and forms C-shape form and can be designed in various versions.

A device for sea rescue is known that contains an inflatable element that comprises a belt with a buckle and a vessel with compressed gas connected to an end of the inflatable element and containing a wall that separates the volumes of the vessel and the inflatable element and the design of the wall includes a destructible part (Russian patent No. 2094299, class B63C 9/15, published on 27 Oct. 1997).
Another device for sea rescue is known that contains rescue bracelet that comprises inflatable elastic buoyant camera tightly rolled and placed into a pocket running along the wristband perimeter, system of gas filling in camera, look for example, as balloon with compressed gas and mechanism for start of system of gas filling, equipped by exhaust cord. Buoyant camera is designed to became C-shape form being filled, came unfolded and featured by length adjusted fastener (Russian patent No. 126312, class B63C9/08 (2006.01), published on 27 Mar. 2013).
Disadvantages of this lifesaver are that it can be filled by compressed gas from balloon and safety of this system is suffering from external impact, for example, direct sun radiation exposes to explode it due excessive overheat. So, balloon should be manufactured with thick-wall shell for safety purposes.
The objective of the invention was to create a more comfortable, cheap and safe individual lifesaver that would be compact and small weight with more high level of safety when it is used in comparison with known technical solution.

Life saving wristband (variants) and gas-generator (variants)


A hyperspectral imaging system and a method are described herein for providing a hyperspectral image of an area of a remote object. In one aspect, the hyperspectral imaging system includes a fore optic with optics for acquiring and projecting an image from a remote object, a scannable slit mechanism with a plurality of slits for receiving the projected image, where the projected image simultaneously illuminates two or more of the plurality of slits, a spectrometer for receiving and dispersing images passing through the two or more simultaneously-illuminated slits, and a two-dimensional image sensor for recording images received from the spectrometer, where the images received from different slits are recorded on different sets of detection elements of the two-dimensional image sensor.

A spectrometer is a device which receives a light signal as an input and produces as an output a light signal which is spread out in space according to the different wavelength components, or colors, of the input light signal. A detector attached to the spectrometer analyzes the output signal, called the spectrum, to quantify the amount of each wavelength component which is present in the input signal. One specific type of spectrometer is known as an Offner spectrometer which can be used to produce images of a remote object over a contiguous range of narrow spectral bands. This type of imaging is known as hyperspectral imaging and has recently emerged as an important part of the military/aerospace solution to airborne and spaceborne reconnaissance and remote sensing. Basically, the hyperspectral imaging system utilizes an Offner spectrometer and an advanced data processing technology to produce imagery with embedded spectral signature data. This signature data is useful in a wide-variety of applications such as target designation/recognition, missile plume identification and mine detection (for example). In addition, the hyperspectral imaging system can be used in a wide-variety of commercial applications such as cancer detection, environmental monitoring, agricultural monitoring and mineral exploration.
A conventional hyperspectral imaging system includes a fore optic for receiving an image from a remote object. The fore optic focuses the image onto a fixed slit. The slit transmits a slice of the image (line of light, trimmed image) to a spectrometer (e.g. prism, diffraction grating), which disperses the light according to wavelength and directs it to a two-dimensional image sensor (e.g. FPA detector) for recording.
One of the limitations of conventional hyperspectral imaging systems is the time required to acquire a two-dimensional image of a scene over a wide area. The limitation is a consequence of the basic design of conventional hyperspectral imaging systems. Conventional systems include a single fore optic and a single fixed slit for receiving and transmitting images to the spectrometer for dispersion and detection. A single fixed slit limits imaging to a single line of light from the remote object, which means that only a limited area of the remote object can be imaged at a time. In addition, a hyperspectral imaging system with a fixed slit is limited to filling only those pixels on the image sensor that correspond to the narrow line image defined by the fixed slit. Commercially-available image sensors typically have a much greater number of pixels than is needed to detect the dispersed light corresponding to the slice of the remote object that is transmitted as the line image originating from the fixed slit. Poor pixel utilization makes image collection inefficient.
To improve the spatial field coverage at a particular resolution, prior art systems may aggregate multiple conventional hyperspectral imaging systems. Multiple hyperspectral imaging systems can be positioned side-by-side such that the linear fields of view of each system are contiguous and imaging of contiguous slices of the remote object can occur in parallel to improve collection efficiency. This solution, however, is impractical for many applications due to the space, weight, and power constraints, as well as the costs of the multiple detectors, coolers, spectrometers, and other components needed for implementation.
There are currently two techniques for extending the hyperspectral imaging capacity of a single hyperspectral device from a single line of light (single slice) of the remote object to a two-dimensional area (multiple slices) of the remote object. The first technique involves moving the entire hyperspectral imaging system in a direction perpendicular to the fixed slit and synchronizing the image taking with that motion to obtain the hyperspectral image of a wide area of the remote object. This technique is often called the "push broom" method. The second technique involves placing a rotating mirror in front of the imaging lens of the fore optic and synchronizing image collection with the motion of the mirror to obtain the hyperspectral image of an area of the remote object.
One of the primary issues encountered in generating a hyperspectral image using the above approaches is the time required to generate a complete image. In either the push broom or rotating mirror methods, a single line of spatial image data passes through the slit and is spectrally interrogated. To sample additional line images (slices) of the scene, the field of view visible in the slit must be systematically moved to adjacent lines of the image (either by adjustment of the scanning mirror, or translation of the imager relative to the object being interrogated), and the process must be repeated until the complete scene is generated line by line. Given the desired high spatial resolution of the images, this method requires hundreds if not thousands of individual line scans to be taken one at a time and combined into a master two-dimensional image.
Although traditional hyperspectral imaging system and traditional techniques for obtaining the hyperspectral image of an area of the remote object may work well in some applications, it is desirable to develop new hyperspectral imaging systems that can be used to obtain the hyperspectral images, especially 2D or areal images, of the remote object. It is particularly desirable to develop hyperspectral imaging systems that are compact, lightweight, and capable of quickly providing an areal image of a scene over a wide area.

Hyperspectral imaging systems and methods for imaging a remote object


A cement restrictor is provided for creating a fixed obstruction within a bone. An exemplary cement restrictor includes a member or body that is expandable or transitionable from a first diameter to a second diameter.

Arthroplasty procedures, such as a total hip replacement, can require the removal of the femoral head and neck, followed by implantation of an artificial hip stem into a reamed portion of the femoral medullary canal. Some hip arthroplasty procedures call for the use of bone cement to secure the hip stem within the medullary canal. For procedures that call for cement, it is generally undesirable to allow the cement to infiltrate the medullary canal to an uncontrolled depth and volume. Therefore, a hip arthroplasty procedure can include the step of placing an obstruction within the medullary canal in an attempt to restrict or block the flow of cement.
Not infrequently, the obstruction is merely a partially hardened or cured ball of cement placed into the canal and held in place by friction fit with the wall of the canal. This makeshift obstruction is easily dislodged by the distal end of the hip stem if the cement ball is not inserted deep enough into the canal. Additionally, the ball of cement is readily displaced when pressurized cement is added to the medullary canal to bind the stem in place. If the cement ball is fractured and/or if it falls beyond a narrow central region of the femur known as the isthmus, the pressurized cement does not properly infiltrate the bone and air pockets or pores are created in the cement. The imperfection laden hardened cement thus provides a poor interlock with the bone and stem and it is susceptible to cracking. Poor mechanical interlock and cement failure causes the stem to loosen. This undesirable occurrence often requires that the joint be replaced in a procedure known as a revision.
Revision surgery and/or procedures requiring a "long" hip stem are especially problematic with an application that calls for pressurized cement. Specifically, the distal end of a revision stem ultimately extends further into the medullary canal than an original "normal" stem because additional bone is cut-away during removal of the original stem in preparation to prepare for implantation of the revision stem, or poor quality bone stock forces a larger stem to be used to secure the stem more distally in the canal to reach better quality bone to achieve implant stability. Whereas the distal end of the original stem may extend to a point before or above the isthmus, and thus above the ball of cement, the distal end of the revision stem may extend beyond the isthmus.
Structures other than cement balls are also known for creating a blockage within a medullary canal. For example, FIG. 1 illustrates a known device 10 including a tapered body 12 having a first end 14, a second end 16, and fins 18 that extend radially from the body. Each fin 18 is resilient and can be flexed toward the first end 14 or the second end 16 of the body 12 as shown in the illustration by dashed lines. Although it is possible to maintain one or more fins 18 in a flexed condition by applying pressure to the fin(s) or placing them in a confined space to elastically deform them, once the pressure is relieved or the device is removed from confinement, the fin(s) will always return to their original position unless they have been plastically deformed. Thus, the fins 18 and the device 10 can be described as only having a single stable state.
In use, a single stable state device 10 can be well suited to the tasks of creating a blockage within a reamed medullary canal 20 above an isthmus region 22 as shown in FIG. 2. It will be noted that the fins 18 are deformed different amounts depending on where they are within the tapered medullary canal 20. The body 12 and the fins 18 can have a thickness such that even when the fins are fully compressed against the body, the device 10 is broader than the isthmus 22 to prevent the device from being readily pushed beyond the isthmus. Thus, in a typical pressurized cement application, the pressurization of the cement does not dislodge the device.
By contrast with an above-the-isthmus application, the device 10 is totally unsuited for beyond-the-isthmus applications as shown in FIG. 3. Specifically, once some of the fins 18 of the device 10 move beyond the isthmus, there is less and less mechanical interlock with the bone and even the application of low pressure causes the plug to be dislodged. Were the device 10 to be deliberately passed beyond the isthmus and then pulled back up into the narrow passage as shown in FIG. 4, the flexed fins 18 would urge the device down and away from the isthmus.

Cement restrictor including shape memory material


An optical disk drive in which changes in rotational speed are achieved under closed loop control, avoiding significant undershoots or overshoots in speed, increasing access time and reducing power. The speed control is suitable for use in a CLV system, in an CAV/CLV scheme, or in any system in which the speed of the disk must be changed at various times. Feedback from the motor, rather than data read from the disk, determines and controls motor speed during all search operations. The disk motor servo determines the desired motor speed for a target track through a speed profile table. The speed profile table can be designed to accommodate a combination of CAV mode and CLV mode of operation such that the disk drive system can run at the maximum data transfer rate permitted by the data processing electronics, or to minimize power consumption. Through closed loop control, the system ensures that the speed of the motor is quickly and accurately changed to the desired speed, typically by the time the optical pickup reaches a target track during a search operation. The closed loop control also allows the disk drive system to be designed for a lower tolerance level and still achieve jitter-free control. Thus the data rate can be increased due to the lower tolerance required. The access time is minimized because the CD-DSP can begin retrieving data as soon as the target track is reached, since the optical disk will generally already at the desired speed.

Compact disks (CD), a type of optical disk, are widely used to store digital data of an audio signal or music information. The music is reproduced from the CD through a compact disk player. Optical disks have been adopted to store a variety of digital data besides audio signals. For instance, a CD-DA is used to store digital audio information; a CD-V is used to store video information such as movies, video clips and Keraoki. Another commonly recognized application of the optical disk in the data processing industry is the CD-ROM. The CD-ROM is a read-only data storage medium used in personal computers for storing digitized information such as large text databases and application programs. CD-ROMs are especially suitable for multimedia applications because of its voluminous storage capability, durability, and low cost. Although the traditional optical disk is a read-only medium used for data reproduction only, optical disks capable of both recording and reproduction have been developed. The CD-R and CD-E are both read/write optical storage mediums. An optical disk drive is used to record or reproduce the digital data onto or from these optical disks.
FIG. 1 shows a simplified block diagram of a typical prior art optical disk drive system used to reproduce data from a CD-ROM. In optical disk drive system 10, CD-ROM disk 12 is rotated by spindle motor 14; optical pickup unit 20 (denoted OPU in FIG. 1) reads the data stored on CD-ROM 12; feed motor (or "sled motor") 22 changes the radial position of optical pickup unit 20; microprocessor controller 40 and a collection of servo and control circuitry command disk drive 10 to perform the desired operations. CD-DSP 30 is a digital signal processor which descrambles the signal read from CD-ROM 12 by optical pickup unit 20 and provides, via CD-ROM controller 39, the digital output data via bus 44 to host computer 50. CD-ROM controller 39 is typically an ATAPI/IDE or SCSI based device, as is well known in the personal computer field.
A CD-ROM disk stores data in the form of pits and lands patterned in radial tracks. The tracks are formed in one spiral line extending from the inner radius of the disk to the outer edge. Unlike typical magnetic disk storage media which stores data in concentric tracks in which data density is more sparse at the outer edge of the disk, CD-ROM records data at a uniform density over its entire surface, that is the same high density of data is stored at an outer track as at an inner track. The uniform density storage pattern accounts for its large data storage capacity over that of the magnetic disk storage media. To facilitate data access in a uniform density storage pattern, the CD-ROM disk is designed to rotate at a constant linear velocity (CLV). In the CLV mode, the rotational speed of the disk varies according to the location of the track to be read so that a constant linear speed is maintained between the disk and the optical pickup unit. Maintaining a constant linear speed between the disk and the optical pickup at all locations on the disk means that the data transfer rate also remains constant at all locations, enabling a uniform density of data to be stored over the entire surface of the disk. In contrast, the magnetic disk storage media are designed to rotate at a constant angular velocity (CAV) where the rotational speed of the disk is kept constant. When operated in a CAV mode, the linear velocity of the disk relative to the optical pickup increases linearly as the read head approaches the outer track. The first CAV mode magnetic disk drives required that the amount of data recorded in a given angular rotation be kept the same throughout the disk. Therefore, the average data transfer rate will increase linearly as the optical pickup travels from the inner radius to the outer edge of the CD-ROM. More modern magnetic disk drives using CAV also use zone bit recording to improve storage capacity by increasing data density per angle of disk rotation as track location increases in distance from the center of the disk.
The advantage of high storage capacity of the CLV mode is offset by the longer access time required to reach a target track in a search operation as compared to the CAV mode. In the CLV mode, the time required to change the rotational speed of the disk whenever different tracks are accessed increases the access time significantly. When a CD-ROM is operated at 1.times. speed (representing the CD-ROM data transfer rate standard of 150 Kbytes/second), the rotational speed of the disk must change from approximately 500 rpm (rotations per minute) when an inner track is to be accessed to approximately 216 rpm when an outer track is to be accessed. In order to provide acceptable and jitter free performance, robust electronics are used in CD-ROM drives which allow reading data from a track when the spindle motor has reached its proper speed associated with that track, within a margin of .+-.50%. This allows reading of the desired track to occur somewhat sooner, and allows the final speed adjustments for that track to be made under closed loop control during the read operation. Since the data rate will not be correct when the motor speed is not correct, the electronics must be robust to allow for this improper data rate. To accommodate the frequent adjustments in rotational speed, a complex high performance, and thus expensive, spindle motor is required. The motor must be capable of generating more power, or producing more torque to reach a target speed quickly, and overcoming more friction. This is particularly true as CD-ROM operation speed increases. Today, it is common to run CD-ROMs at 8.times. speed or higher. At 8.times. speed, the rotational speed of the CD-ROM changes from near 4000 rpm at the inner track to about 1728 rpm at the outer track. At this rapid rotation rate, effective control of the speed of the motor becomes critical, especially for reducing the access time in a search operation. Furthermore, as CD-ROM speed increases, the design of the CD-DSP becomes increasingly difficult of the .+-.50% speed tolerance is to still be achieved. This .+-.50% guardband also limits the data rate possible under proper motor speed.
Conventional optical disk drive systems use open loop control of the motor speed in search operations and closed loop control during normal play or track following. In an open loop control, the spindle motor is driven in a kick and brake manner for changing the rotational speed as illustrated in FIG. 2. FIG. 2 shows a family of curves representing the rotational speed of the motor as a function of the radius of the optical disk. Curves 60, 62 and 64 depict the increase in rotational speed with respect to increasing CD-ROM speed from 8.times. to 16.times., when the CD-ROM is operated in a CLV mode across a variety of radiuses. When a track closer to the circumference of the disk is to be assessed, such as when the optical pickup must move from point A to point B, the motor must reduce the rotational speed of the disk. Therefore, a brake operation is initiated to decelerate the motor. Due to the presence of back EMF at the motor, it takes longer to accelerate the motor than to decelerate it a given change in rpm. Thus, the brake operation is typically terminated when the rotational speed is still above desired value, as indicated by point B1 in FIG. 2. Then, the rotational speed is further reduced to the desired value in fine increments by subsequent brake operations, until CD DSP 30 is able to synchronize with the sub-code bits stored on the desired track (typically when the speed reaches .+-.50% of the proper speed, due to the large tolerances built into the data recovery electronics), at which time closed loop speed control is used, based on the sub-code sync signal. It is highly undesirable to reduce the rotational speed too much as shown by point B2 because the motor must then be accelerated to the desired value at B by one or more kick operations, increasing the access time significantly. The converse is true when a track closer to the disk center is to be accessed, as illustrated by points C and D. The spindle motor must be accelerated as the optical pickup moves towards the center of the disk. The desired procedure is to accelerate the motor to above the desired value (i.e. to point D2) and then decelerate it in fine increments by subsequent brake operations to the desired speed (point D). This open loop control system is problematic because both time and power are wasted because the motor speed adjustments must be made with unavoidable overshoots and undershoots.
Contrary to the CLV mode, the CAV mode is characterized by very fast access time, i.e. the time required to move the optical pickup radially to a desired track and establish valid reading of data from that track at a tolerable spindle motor speed. Because the rotational speed is kept constant, the optical pickup can immediately retrieve disk data when the target track is reached. CAV mode operates without the added delay of waiting for the spindle motor speed to settle to the correct rpm.
In order to improve the data rate and access time of an optical disk drive under certain circumstances, various operating modes other than simply CLV have been suggested. FIG. 3-1 shows a graph depicting, in relative terms, the rotational speed and resulting data rate in a CLV mode of operation, as tracks are read from the inner diameter to the outer diameter of the CD-ROM. Since it is a CLV system, the rotational speed S1 decreases from the inner diameter to the outer diameter of the CD-ROM, and the data rate remains substantially constant. The substantially constant data rate makes for relatively simple data recovery circuitry, although as previously described the fact that a different rotational speed S1 is required for different tracks results in delays in access time as track changes are made.
Another prior art system, such as described in U.S. Pat. No. 5,388,085, uses a modified CAV (MCAV) method wherein the disk is rotated at a constant angular velocity while the data transfer rate is varied according to the radial position of the track accessed. FIG. 3-2 depicts this constant angular velocity as curve S2, and the resulting data rate D2 which increases proportionally from the inner diameter to the outer diameter of the CD-ROM.
A more commonly used approach involves a combined CAV/CLV scheme where the optical drive operates in a CAV mode at the inner tracks and switches to a CLV mode at the outer tracks. FIG. 3--3 is a graphical representation of the rotational speed profile, and the resulting data rate, of such a CAV/CLV system. As shown in FIG. 3--3, the constant angular velocity at the inner diameter tracks, as depicted by curve S3, is limited by the rotational speed of the drive motor and related mechanical components. At a certain point, the data rate is limited by the electronic components in the data recovery circuitry, resulting in a maximum data rate, as depicted by curve D3. In order to not increase the data rate further, at this point, the CD-ROM is operated in a CLV mode, with the rotational speed decreasing as tracks closer to the outer diameter of the CD-ROM are read. Although the CAV/CLV scheme has a lower data transfer rate at the inner tracks due to the maximum rotational speed of the motor, and related mechanical constraints due to vibration, etc., the resulting in overall system performance is acceptable and greater than the data transfer rate under CLV control over the entire CD-ROM since the need for motor speed adjustments within the CAV operating portion of the curves of FIG. 3--3 is precluded.
U.S. Pat. No. 5,521,895 describes a system in which normal data reading is performed under CLV control, and changes in rotational speed are achieved by increasing the speed to a fixed CAV speed and subsequently decelerating to the speed necessary to continue the CLV operation at the new track location.
To reap the maximum benefit of a CAV/CLV operation scheme, there is still a need to have accurate control of the angular velocity of the motor, since as depicted in FIG. 3--3, rotational speed adjustments are needed when changing tracks within the CLV portion of curve S3, or changing between the CAV and CLV portions of curve S3. Note that it is common to break the CLV portion of curve S3 into a plurality of zones (not shown) so that the CLV portion of the curve is not truly linear, but rather is approximated in a stair-step fashion. Nonetheless, there are a number of discreet motor speed values within the CLV portion of curve S3, necessitating changes in the motor speed when reading tracks within different zones.
Today's disk drive systems are required to provide for a +/-50% tolerance in order to meet the jitter-free control requirement. That is, the optical pickup must be able to read data even if the rotational speed is +/-50% of the target speed. The large tolerance level imposes design constraints on the disk drive electronics. It is desirable to reduce the tolerance level so as to remove unnecessary design constraints, particularly as the speed of the CD-ROMs increase to 8.times. and greater. In order to maintain proper control of the motor speed, there is a need to monitor the actual rotational speed of the motor. Current disk drive systems rely on reading a subcode sync signal from the disk which indicates the linear velocity of the track being read, and thus motor speed. This method depends on the optical pickup unit being able to accurately read the subcode sync signal from the CD-ROM and the CD-DSP (FIG. 1) being able to quickly descramble the signal. This sub-code is formed of 98 bits, with one frame of data stored on the CD-ROM containing one of the bits forming the sub-code. Thus, 98 frames of data must be read in order to obtain the 98 bits forming the sub-code. This method is time consuming and becomes increasingly inaccurate as CD-ROM speed increases. Thus, it is desirable to have some other method of monitoring the spindle motor speed.
Regardless of the method used in the prior art for selecting the desired rotational speed associated with each track on a CD-ROM being read, changes in rotational speed are performed in open loop fashion, using kick and brake operations. As previously described, in the more sophisticated prior art systems, care is taken not to undershoot a desired rotational speed, since acceleration is more time and power consuming than deceleration. Thus, by virtue of this open loop control, and the successive brakes required to fine tune the deceleration to achieve the desired rotational speed, changes in rotational speed are time consuming, thereby having a deleterious effect on the access time of CD-ROMs.

Optical disk motor servo and method for closed loop speed control