Provided is a display device which includes: a display panel having a display screen on which an image is displayed; and a touch panel which is arranged on a display screen side of the display panel. The display panel includes: a first substrate; a second substrate which is arranged on a side closer to the touch panel than the first substrate; and a polarizer which is arranged on a touch panel side of the second substrate. The touch panel is formed larger than the polarizer and is laminated to the polarizer. An auxiliary member is arranged between the touch panel and a portion of the second substrate which is exposed from the polarizer.

1. Field of the Invention
The present invention relates to a display device with a touch panel.
2. Description of the Related Art
There has been known a display device with a touch panel which detects a position depressed by the finger, a dedicated-use pen or the like. Further, the display device is configured such that, for example, the touch panel is laminated to a display screen side of a display panel such as a liquid crystal display panel.
Further, as one of touch panel systems, there has been known a resistance-film-type touch panel. In the resistance-film-type touch panel, two substrates on which a transparent conductive film is formed respectively are laminated to each other by way of a large number of spacers so that an effective region where a depressed position can be detected is formed into a hollow space. There may be also a case where the touch panel is required to satisfy conditions such as being light-weighted or possessing impact resistance and hence, a film-like member may be also used as a substrate which constitutes a touch panel.
JP2009-30029 A discloses a polyester resin composition which has excellent flexibility (tensile elongation and impact resistance), excellent appearance of a molded product (surface gloss), excellent hydrolysis resistance, and excellent moldability (residence heat stability) while being a thermoplastic resin composition which is filled with inorganic fillers at high density and has highly densified ceramic-tone high-class material quality feeling.
JP2008-47026 A (U.S. Published Patent No. 2008/0042997 A1) discloses a touch panel having a curved shape. The touch panel having a curved shape comprises an upper film substrate and a lower film substrate. Each film substrate are formed from a transparent plastic film having a transparent electrically conductive polymer layer, an electrode, and a wiring pattern formed thereon.


Disclosed is a system and method for controlling Session Initiation Protocol (SIP)-specific event notification corresponding to an event subscription according to a preference of a subscriber. The system includes the subscriber requesting an event subscription through an event notification controller; a subscription target for notifying the subscriber of the event through the event notification controller in response to the event subscription request; and the event notification controller for controlling whether the event notification is forwarded to the subscriber according to the preference rules of the subscriber on event notifications. Accordingly, the event notifications to the subscriber can be effectively controlled according to the preference rules of the subscriber on event notifications, and it is possible to prevent the generation of unnecessary event notification that the subscriber does not desire.

1. Field of the Invention
The present invention relates to a system and a method for Session Initiation Protocol (SIP)-specific notification (i.e. SIP-based notification) corresponding to an event subscription. Particularly, the present invention relates to the improvement of a method for notification corresponding to an event subscription. Also, the present invention relates to the improvement of a system and a method for notifying a presence event in order to forward presence information in a presence system, by using the system and the method as described above.
2. Description of the Related Art
"SIP-Specific Event Notification" identified by RFC (Request for Comments) 3265 of IETF (Internet Engineering Task Force) describes a method for forwarding a state of a particular event by using an SIP SUBSCRIBE and an SIP NOTIFY.
FIG. 1 is a flow diagram illustrating an SIP-specific event notification (i.e. SIP-based event notification) method. Referring to FIG. 1, when a user desires to keep up with the latest information on the state of a particular event (i.e. the latest state information on a particular event), he/she subscribes to the relevant event as a subscriber. A subscription target having state information on the relevant event continues to notify the subscriber of the latest state information on the relevant event in response to a request of the subscriber.
FIG. 2 is a flow diagram illustrating a typical example of a signaling flow in the SIP-specific event notification method according to the RFC3265. As described above, the subscriber forwards a SUBSCRIBE request to the subscription target with respect to a event named "foo". The subscription target determines if the subscriber can subscribe to the "foo" event. When the subscriber requesting subscription to the "foo" event is authorized, a current state of the "foo" event that the subscription target knows of is forwarded to the subscriber by using a NOTIFY Subsequently, whenever a state of the "foo" event is updated, the most recently updated state of the "foo" event is forwarded to the subscriber by using a NOTIFY.
A presence service requests and forwards presence information by using the SIP-specific event notification technology as described above. To this end, "a Presence Event Package for the SIP" identified by RFC3856 defines a presence event package. Herein, the presence event becomes the presence information. Referring to FIG. 3, a watcher can request presence information of a presentity through a subscription to the presence event. The presence information of the presentity is forwarded to a presence server of the presentity (i.e. a presentity's presence server) which maintains the presence information of the presentity. Through a series of notifications of presence events, the presence server forwards the presence information of the presentity and updated presence information thereof to the watcher.
FIG. 4 is a flow diagram showing a typical example of a signaling flow of requesting and forwarding presence information by using a presence event package. In FIG. 4, the watcher, the presence server of the presentity, and the event correspond to the subscriber, the subscription target, and "foo" as illustrated in FIG. 2, respectively. Accordingly, as in the process illustrated in FIG. 2, the watcher makes a request for a subscription to the presence event to the presence server of the relevant presentity in order to receive the presence information of the presentity. The presence server of the relevant presentity authorizes the subscription request, and then continues to notify the watcher of the most recently updated presence information on the relevant presentity.
By expanding the scheme for providing a presence service on one presentity as described above, the watcher can simultaneously subscribe to presence services on multiple presentities. To this end, the watcher subscribes to a presence service on a presence list by using a Resource List Server (RLS). The term "presence list" refers to a set of multiple presentities. By subscribing to the presence service on the presence list, the watcher can simultaneously subscribe to presence information on the multiple presentities.
FIG. 5 is a flow diagram illustrating the process of subscribing to the presence service on the presence list. In FIG. 5, if the watcher requests a subscription to the presence list, the subscription request is forwarded to the RLS. The RLS resolves the relevant presence list, and subscribes to a presence service on each of the members on the presence list for the watcher. Thereafter, the RLS receives the presence of each presentity, aggregates the received presences, and simultaneously forwards the aggregated presences to the watcher. By doing this, without the need for a subscription to a presence service on each of the multiple presentities, the watcher can simultaneously obtain the presence information on the multiple presentities.
In the SIP-specific event notification technology as described above, whenever an event is updated, relevant notification is generated in order to forward the updated event. Accordingly, the requirements of a system need to become more sophisticated in order to forward and process each generated notification.
Especially, in the case of a presence service provided by using the presence event package, when considering multiplicity of the watchers and presentities and the fact that the presence information is frequently updated, a traffic load becomes unbearably high due to the notification of a presence event generated whenever the presence information on each presentity is updated.
As a result, there has been an urgent need for a scheme capable of effectively reducing the SIP-specific event notification, especially, a volume of the presence event notifications.

System and method for controlling SIP-specific event notification according to preference of subscriber


A thermal management system includes a refrigerant loop, a motor coolant loop, and a battery coolant loop. The refrigerant loop includes a first refrigerant main-line, a second refrigerant main-line, a first refrigerant branch, and a second refrigerant branch. The first refrigerant main-line includes a compressor, the second refrigerant main-line includes a cabin condenser, the first refrigerant branch includes a cabin evaporator, the second refrigerant branch includes a radiator. The first refrigerant main-line and the second refrigerant main-line selectively communicate with one of the first and second refrigerant branches. The battery coolant loop includes a coolant main-line, a first coolant branch connected to the cabin evaporator, a second coolant branch connected to the cabin condenser, and a third coolant branch. The coolant main-line selectively communicates with at least one of the first to third coolant branches. The battery coolant loop connects to the motor coolant loop in series or in parallel.

An electric vehicle operates by using a motor that receives electricity from a battery and outputs power. Electric vehicles discharge very little carbon dioxide and generate very little noise. The motor of the electric vehicle has energy efficiency higher than that of internal combustion engine.
However, a driving range of the electric vehicle is reduced in cold weather. Therefore, there is room for improvement in the art.

Thermal management system and electric vehicle having the same


An automotive sun visor including a visor member pivotably connectable adjacent a vehicle windshield and having a single viewing aperture defined by a frame connected around the perimeter of a hole formed through the visor member. The viewing aperture is positioned centrally nearer to the pivoted margin of the visor member and sized to allow the driver of the vehicle to observe a traffic signal through the viewing aperture. Various modification to the frame and the shape of the viewing aperture are also provided to further block observance of bright sunlight around a traffic signal.

1. Field of the Invention
This invention relates generally to vehicle components, and more particularly to an improved driver's side sun visor structured to allow the driver of the vehicle to observe a traffic light signal as when at a standstill therefor absent sunlight glare.
2. Description of Prior Art
Virtually all motor vehicles are equipped with at least a driver's side sun visor which is pivotally connected along an upper longitudinal margin thereof adjacent the windshield of the vehicle. In its pivoted downward in-use position, the sun visor generally blocks a portion of incoming sunlight entering the vehicle through the front windshield, while simultaneously reducing the area for viewing oncoming sky and sunlight and traffic signals.
In most instances, the presence of the sun visor in its downwardly in-use position does not obstruct any useful traffic visibility required by the driver. However, overhead traffic light signals, especially as the vehicle approaches or is stopped at an intersection, may become obscured from the driver's line of sight when the sun visor is in use.
In such situations, the driver must bend forwardly so as to facilitate line of sight with the traffic signal or pivot the visor into its upper stored position. In such situations, however, this may subject the driver's eyes to the very bright sunlight which the sun visor is otherwise blocking.
In extreme circumstances such as during morning and evening commuter traffic, this deficiency is quite acute, leaving the driver to either be temporarily "sun blind" to view a traffic signal or to simply hope for the best by observing movement of adjacent traffic.
A number of devices in prior art have attempted to address this problem by either modifying or adding to existing sun visors in a fashion which restricts or blocks the amount of sunlight which is able to be viewed by the driver passing through the windshield.
Cramer, in U.S. Pat. No. 4,362,330 teaches a see-through automobile sun visor which includes a plurality of spaced slots formed through the visor member which may be made viewable therethrough or blocked based upon the selective positioning of a separate movable slotted member. However, the complexity of this device, coupled with the range of selective adjustability, tends to render this invention somewhat impractical.
A sun visor for automobiles is disclosed in U.S. Pat. No. 4,512,605 invented by Aschermann which teaches a sun visor slidable along a guide rail between a stored and an in-use position without being swiveled around a bearing.
Takahashi discloses a sun visor for automobiles in U.S. Pat. No. 4,726,620 wherein a perforated sheet having at least a portion thereof a large number of fine holes therethrough which render the visor somewhat "see-through".
Takahashi has also invented another such invention as shown in U.S. Pat. No. 4,890,875 which includes a transparent sheet having a surface on which a translucent sheet is attached formed of reticulated patterns forming fine through-holes.
Masi, in U.S. Pat. No. 3,445,135, teaches a perforated sun visor as an accessory to a conventional sun visor structured to be connected along the bottom of the sun visor.
The present invention is considerably simpler in construction and mode of use and design for the express purpose of only allowing limited viewability of traffic signals in close proximity to the vehicle. Variations of the invention further limit the viewable light surrounding a traffic light so that the driver may, by side to side head and eye movement, be totally blocked from having to view bright sunlight which surrounds the field of vision of the traffic signal while still having immediate sight access to the stop signal by appropriate head and eye movement.


A work piece holding arrangement (10) includes an array of engagement elements (12) for engaging a work piece. The arrangement (10) also includes an actuator (34) for moving a plurality of the engagement elements (12) into engagement with the work piece, and a deformable clamping member (26) to clamp the engagement elements (12). The clamping member (26) is deformable between a clamping condition in which at least some of the engagement elements (12) are engaged by the clamping member (26) and clamped in respective positions, and a non-clamping condition in which the engagement elements (12) can move.

During the manufacture of fan, turbine and compressor blades of a gas turbine engine, it is necessary to machine it to exact specifications. In order to effect this machining, the blades have to be held in position. This is currently carried out by tooling which clamps the aerodynamic surfaces of the blades to deform them to the shape of the tool. When the tooling releases the blade, it springs back to its original shape. This can be disadvantageous, because each blade requires its own special tool, and when the blades spring back to their original shape, this can change the position of machine features relative to the blades datum.


The system (10) of FIG. 1 uses fixedly-located master and slave smartphone devices (12, 14) to determine a player position of a player (20) within playing arena, such as a tennis court. The master device (12) makes a local determination of the speed of sound using an audible ping to the slave device displaced from the master device by a known distance. The slave device (14) also responds with a time stamp associated with the receipt of one or more pings. Correlation over successive RF-reported time stamps allows the master device (12) to assess, relative to its own internal reference clock, a time offset and drift for a local clock in the slave device (14). A RF connection to a communications circuit and sensor (18) arrangement located in a racket held by a player permits the master device (12) to assess a time offset and drift for a local clock associated with the sensor. The sensor (18) further includes a gyroscope, accelerometer and magnetometer that cooperate to record movement or orientation of the racket, and which information is uplink reported over the RF connection to the master device. When an amplitude or modelled sound profile for a “hit” event (24) is detected by both the master and slave devices (12, 14) and the hit event time-stamped by the devices in the system and reported to the master by the communications circuits of the racket and slave units, the master unit is able to triangulate the position of the hit event relative to known dimensions of the playing arena. Continuous reporting of movement of the racket relative to the previous hit event can therefore be displayed to show movement of the player around the court relative to detected sound events.

This invention relates, in general, to a tracking system and is particularly, but not exclusively, applicable to a mobile system and related method that monitors and analyses the relative movement of a person in a sporting arena. For example, the mobile system provides analysis of court position and relative movement of a player following the detected hitting of a tennis ball by the player's racket.

Tracking system and method for determining relative movement of a player within a playing arena


A single focus lens includes, in order from the object side: a diaphragm stop; and first and second lens components, each lens component being of positive refractive power and each having a convex surface on the object side at least near the optical axis. Each of the two lens components has two aspheric surfaces, may be a lens element, and preferably is made of plastic. The single focus lens may include no other lens elements and the diaphragm stop may be on the object side of the single focus lens. Specified on-axis conditions are satisfied in order to reduce aberrations and to make the single focus lens compact. Additionally, satisfying a condition related to the aspheric shapes of the lens components helps reduce aberrations.

In recent years, along with the popularization of personal computers into homes, digital still cameras (hereinafter referred to simply as digital cameras) that enable input of picture image information, such as photographed landscapes and portraits, into a personal computer are rapidly becoming more popular. Additionally, with enhancements in portable telephone functions, portable cameras that include compact imaging modules are rapidly becoming more popular. Additionally, including an imaging module in compact information terminal equipment, such as PDAs (Personal Digital Assistants), is becoming popular.
In such devices that include an imaging function, an image pickup element, such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), is used to provide the imaging function. Recently, advancements in the miniaturization of such image pickup elements have been rapidly increasing. This has resulted in a desire for the main body of such devices and other imaging equipment, such as the imaging lens system, to also be further miniaturized. Additionally, image pickup elements with a larger number of pixels in the same area have been developed in order to achieve higher image quality, which creates a demand for higher resolution lens systems that are still very compact. Japanese Laid-Open Patent Application 2000-258684 describes exemplary single focus imaging lenses for such devices that include only two lens elements.
As stated above, recent image pickup elements are smaller and provide more pixels in a given detector area, which helps meet demands of higher resolution and more compactness that are especially required in imaging lenses for digital cameras. Although considerations of small cost and compactness have been the main considerations for imaging lenses for compact information terminal equipment, such as portable telephones with cameras, such devices have been commercialized with megapixel detectors (detectors that detect one million or more pixels), indicating increasing demand for higher performance in these devices as well. Therefore, development of lens systems with a wide range of applications based on properly balancing considerations of cost, performance, and compactness is desired.
As imaging lenses for compact information terminal equipment having a large number of pixels, conventionally there has been developed a lens system having three lens components, each of which may be a lens element, with at least two lens elements being made of plastic, while the third lens element may be made of plastic or glass. However, in order to meet recent demands for greater miniaturization, a lens that uses a smaller number of lens components and lens elements, but which is equivalent in performance to these conventional lenses, is desired.
Although the lenses described in Japanese Laid-Open Patent Application 2000-258684, referenced above, each have a two-component, two element lens construction, which includes aspheric surfaces, a lens system that is even more compact and higher in performance than this is desired. Because the lateral color aberration tends to become especially large in compact imaging lenses, particularly desired is a single focus lens with well corrected lateral color.

This patent is subject to a terminal disclaimer.

Single focus lens including a front stop


In a method for the display of optical information in an application with a display in a motor vehicle, the information is available in a given format. The information format is changed by a data processing process based on control information. The information is displayed in a changed format on the application page.

In today's motor vehicles, there are a multiplicity of components which transmit information to the driver and which generate acoustical and optical signals, potentially distracting the driver and diverting his/her concentration from the road traffic. Besides the classic car radio where the driver can listen to traffic news, these include, for example, navigational systems having optical and acoustical route guidance, mobile telephones provided with hands-free kits, i.e., car phones, and multifunctional display units having changing graphical interfaces. For that reason, to display city maps, road maps, routes, and other optical information, a motor vehicle is provided with a color display of an appropriate size for displaying television and video images.
The Internet and intranet have become important instruments for quickly acquiring information and for using services. However, difficulties arise when displaying information from the net, i.e., from web sites, in motor vehicles, due to ergonomic reasons, since, for example, brightly illuminated video displays can produce glare for the driver during nighttime driving. However, Internet web sites are always displayed with the coloration predefined by the web site provider. This can result in the legibility and display of web sites not being compatible with some applications. This is because, at the present time, the colors of web sites are not adaptable, without running the risk that adapting another web site using the same method results in this web site no longer being readable, for example, because the text and background color are suddenly identical or similar, so that no contrast at all or only a very poor contrast is achieved.
For that reason, it is an object of the present invention to display information from the Internet or intranet on a motor vehicle display that may enable the driver to take in the information with the greatest possible certainty.

Method and device for the display of information


Methods for analyzing sag in a section of a wellbore may utilize computational methods that produce sag profiles, which may be useful in performing further wellbore operations. The computational method may include inputs of at least one wellbore fluid property, at least one wellbore condition relating to a section of a wellbore, at least one operational parameter into a computational method, and any combination thereof. Further, the computational methods may include a mass balance analysis for individual elements of the meshed section of the wellbore.

The exemplary embodiments described herein relate to methods for analyzing sag in a section of a wellbore via computational methods and performing wellbore operations based on a sag profile produced from the computational methods.
The wellbore fluids used in many wellbore operations include weighting agents (e.g., particles having a density greater than the base fluid including barite, ilmenite, calcium carbonate, marble, and the like) to increase the density of the wellbore fluid. The density of a wellbore fluid effects the hydrostatic pressure in the wellbore, which, when properly matched with the pore pressure of the formation, maintains the formation fluids. If the hydrostatic pressure in the wellbore is too low, the formation fluids may flow uncontrollably to the surface, possibly causing a blowout. If the hydrostatic pressure in the wellbore is too high, the subterranean formation may fracture, which can lead to fluid loss and possibly wellbore collapse.
As used herein, the term "sag" refers to an inhomogeneity or gradation in density of a fluid resulting from particles in the fluid settling (e.g., under the influence of gravity or secondary flow). Sag can be exacerbated with elevated temperatures.
Oftentimes in a wellbore operation, the circulation of the wellbore fluids through the drill string and wellbore is halted such that the wellbore fluid becomes substantially static in the wellbore (e.g., drill string tripping). In some instances, a low shear condition that allows for sag may be encountered when circulation is slowed, when the circulation may be halted and the drill string may be rotating, or a hybrid thereof. As used herein, the term "low shear" refers to a circulation rate of less than about 100 ft/min or a drill string rotation rate of less than 100 rpm. Static or low shear wellbore fluids may allow the weighting agents to settle (i.e., sag). Sag may not occur throughout an entire wellbore, but its occurrence in even a small section of the wellbore can cause well control issues like kicks, lost circulation, stuck pipes, wellbore collapse, and possibly a blowout. For example, if the density of the wellbore fluid, and consequently hydrostatic pressure, are higher than the fracture gradient of the formation, the formation may fracture and cause a lost circulation well control issue. In another example, sag may lead to a portion of the wellbore fluid having a sufficiently high density for a pipe to get stuck therein. Unsticking the pipe can, in some instances, cease the wellbore operation and require expensive and time consuming methods. In yet another example, large density variations in the wellbore fluid from sag can result in wellbore collapse. In another example, in some instances the lower density portion of the sagged fluid may readily flow when circulation is resumed or increased and leave the higher density portion of the fluid in place, which is time consuming and expensive to remove. Each of these well control issues and potential remediation are expensive and time consuming.
Sag in wellbore fluids is exacerbated by higher temperatures and deviation in the wellbore. Therefore, the recent strides in extended reach drilling, which have resulted in highly deviated wellbores at greater depths where temperatures can be greater, increase the concern for and possible instances of sag related problems in the oil and gas industry.

Wellbore operations involving computational methods that produce sag profiles


A high frequency plug formed of a housing, a load board and a cable organizer is disclosed. The cable organizer has top, bottom, left and right guide grooves for guiding the four twisted pairs of the cable, and a vertical opening hole in communication between the top and bottom guide grooves to enhance cross talk between the pair of the third and sixth wires and the pair of the fourth and fifth wire, thereby achieving de-embedded effect and improving the transmission quality. The cable organizer is molded from plastic with conductive material or EMI/RFI shielding material, eliminating interference and improving the transmission quality.

1. Field of the Invention
The present invention relates to electric plugs and more particularly, to a high frequency plug, which is comprised of a housing, a load bar, and a cable organizer, wherein the cable organizer has top, bottom, left and right guide grooves for guiding the four twisted pairs of the cable and a vertical opening hole in communication between the top and bottom guide grooves to enhance cross talk between the pair of the third and sixth wires and the pair of the fourth and fifth wire, thereby achieving de-embedded effect and improving the transmission quality.
2. Description of the Related Art
In conventional high frequency plugs, the 8 wires (i.e., the 4 twisted pairs) may interfere with one another. High frequency plug manufacturers are trying hard to develop a high frequency plug that eliminates or significantly reduces interference.
FIG. 1 is a schematic view, partially in section, of a high frequency plug 6 according to the prior art before stamp of the holding down block 612 of the housing 61. FIG. 2 is a cross sectional view of FIG. 1. As illustrated, the twist pitch of the twisted pairs 74;75, 73;76, 71;72, 77;78 remains unchanged. However, when the holding down block 612 of the housing 61 is stamped against the cable 7, as shown in FIGS. 3 and 4, the bottom side 6121 of the holding down block 612 is pressed on the cable 7, causing deformation of the cable 7. At this time, the pitch among the twisted pairs 74;75, 73;76, 71;72, 77;78 is changed, affecting normal signal transmission.


A rat and wild animal catcher mainly comprise a cage having two lateral open ends each having a gate the top edge of which pivotly connects to the top grid of the cage and the bottom edge of which extends outward and downward toward the bottom grid of the cage. A step member inside the cage is pivotly connected to the bottom grid of the cage such that when a rat or wild animal enters the cage and touches the step member, the step member is subjected to a downward force and causes the up lifted gates to fall down at the same time and close the open ends of the cage to prevent the caught rat or wild animal from coming out of the cage.

To capture rats, people usually use a spring clamp plate which is positioned at where rats often pass by, such as foot of walls, corners, or shadowed places. To use the spring clamp plate, a spring clamp thereon must first be pulled open and fixed in place so that it can be actuated to spring back and catch the rat when a rat touches it. Such spring clamp plate has considerable killing force and is very dangerous even to small children or pets in the house if the spring clamp is not carefully fixed in place and is carelessly touched and actuated by child or pet playing around in the house. Moreover, a rat being caught by the tail or leg might very possibly struggle with all its strength which causes bleeding and even broken tail or leg of the rat, and inevitably causes environmental contamination. Therefore, such spring clamp plate has been gradually given up.
The cage presently adopted to catch rats can generally avoid the above-mentioned shortcomings. However, such cage usually has only one inlet and therefore must be positioned against a wall or wall corner with the inlet facing outward, allowing a rat to enter for the bait. As a result, the application of such cage is largely limited. Besides, such cage is usually less effective because the only one inlet very often alarms the rats.
It is therefore desirable to have a rat catcher which can be freely positioned with less limitation and is more effective in capturing the rats.


A tamper evident RFID circuit uses a fold section that forms a capacitive element when folded together.

A passive RFID circuit (transponder) generally consists of a tuned circuit, which often takes the form of a external antenna which receives both power and an information signal from the electromagnetic field emanated by a second system component (RFID reader), and a integrated circuit, which contains the microprocessor and memory components by which the transponder decodes and respond to an interrogation signal.

Tuned radio frequency identification (RFID) circuit used as a security device for wristbands and package security


A method and a related apparatus for diagnosing crosstalk within an optical pick-up unit by utilizing firmware. The method includes calculating a tracking driving signal and a focusing driving signal according to a tracking error signal and a focusing error signal respectively, adding a noise to the focusing driving signal to form a test focusing driving signal through executing firmware, driving an optical pick-up unit by the tracking driving signal and the test focusing driving signal, and diagnosing characteristics of the pick-up unit through observing the tracking error signal.

1. Field of the Invention
The present invention relates to a method and a related apparatus for diagnosing an optical disk drive. In particular, the present invention discloses a method and a related apparatus for diagnosing crosstalk within an optical pick-up unit by utilizing firmware of the optical disk drive.
2. Description of the Prior Art
Please refer to FIG. 1, which is a block diagram of a prior art optical disk drive 10. The optical disk drive 10 is used for reading data stored on an optical disk 11. The optical disk drive 10 has an optical pick-up unit (OPU) 12, a spindle motor 14, a motor controller 16, a focusing controller 18, a tracking controller 20, a microprocessor 22, a servo system 24, and a signal converter 26. The OPU 12 emits a laser Li with a predetermined wavelength and predetermined power to the optical disk 11. It is well-known that spiral track 28 is formed on the optical disk 11. In addition, the track 28 records a plurality of lands and pits with different lengths for storing eight-to-fourteen modulation (EFM) data. For example, the land corresponds to the low logic value "0", and the pit corresponds to the high logic value "1". In addition, when the laser Li spots the pits and lands on the track 28, the laser Li is modulated by the pits and lands to generate a reflecting laser Lr. The magnitude of the reflecting laser Lr generated from the laser Li spotting the land is greater than the magnitude of the reflecting laser Lr generated from the laser Li spotting the pit. Therefore, the OPU 12 is capable of detecting the reflecting laser Lr to generate a corresponding analog electric signal EFMa. Then, the signal converter 26 transforms the analog electric signal EFMa into a digital electric signal EFMd. In the end, the microprocessor 22 decodes the received digital electric signal EFMd to obtain wanted data DATA stored on the optical disk 11.
In addition, when the optical disk 11 is loaded into the optical disk drive 10, the microprocessor 22 drives the motor controller 16 to adjust rotation speed associated with a spindle of the spindle motor 14, and the microprocessor 22 also drives the servo system 24 to control the position of the OPU 12 corresponding to the optical disk 11. As mentioned above, the OPU 12 adopts the optical means to retrieve the data recorded by the track 28. Therefore, if the laser Li cannot be precisely focused on the track 28, the electric signal EFMa generated from the OPU 12 contains erroneous information. Similarly, if the laser Li forms a spot on the optical disk 11, and the location of the spot is deviated from the target track 28, the electric signal EFMa generated from the OPU 12 contains incorrect information. Therefore, when the OPU 12 is operating, the OPU 12 generates a focusing error signal FEO and a tracking error signal TEO. Then, the focusing controller 18 calculates a focusing driving signal FOO to the servo system 24 according to the focusing error signal FEO, and the tracking controller 20 calculates a tracking driving signal TRO to the servo system 24 according to the tracking error signal TEO. Thus, the servo system 24 is capable of moving the OPU 12 vertically for adjusting a vertical gap between the OPU 12 and the optical disk 11 through the focusing driving signal FOO, and is capable of moving the OPU 12 horizontally for adjusting a horizontal displacement of the OPU 12 above the optical disk 11 through the tracking driving signal TRO.
From the above description, it is understood that the focusing operation and the tracking operation for the OPU 12 greatly affect accuracy of the final electric signal EFMa. If the signal quality of the electric signal EFMa is bad, the wanted data DATA cannot be correctly obtained even if the microprocessor 22 enables an error correction mechanism. Therefore, the OPU 12 has to accurately generate the focusing error signal FEO and the tracking error signal TEO. Otherwise, the focusing controller 18 and the tracking controller 20 are unable to figure out the wanted tracking driving signal TRO and the focus driving signal FOO. In other words, the servo system 24 cannot move the OPU 12 to a correct position for retrieving data recorded on the track 28 of the optical disk 11.
Before the optical disk drives 10 leave the factory, component characteristic of the OPU 12 need to be carefully tested to filter out optical disk drives 10 having abnormal OPUs 12. Please refer to FIG. 2, which is a diagram of a prior art optical disk drive diagnosing system 40. The diagnosing system 40 includes the optical disk drive 10 shown in FIG. 1, a dynamic signal analyzer 42 (HP35670A for example), and a mixer 44. The optical disk drive 10 shown in FIG. 2 only contains the OPU 12, the focusing controller 18, the tracking controller 20, and the servo system 24 for simplicity. Input ports A, B of the dynamic signal analyzer 42 are respectively connected to the OPU 12 and the focusing controller 18. That is, the tracking error signal TEO outputted from the OPU 12 is passed to the input port A of the dynamic signal analyzer, and the focusing driving signal FOO calculated by the focusing controller 18 is delivered to the input port B of the dynamic signal analyzer 42. In addition, an output port C of the dynamic signal analyzer 42 outputs a testing signal TEST to the mixer 44. The testing signal TEST functions as a noise to interfere with the focusing driving signal FOO calculated by the focusing controller 18. As shown in FIG. 2, the mixer 44 finally mixes the focusing driving signal FOO and the testing signal TEST, and outputs a test focusing driving signal FOO″ to the servo system 24. The testing signal TEST generated from the dynamic signal analyzer 42 is used for simulating a noise, and is generally a sine wave with a frequency gradually increased from an initial value toward a target value. At the same time, the test focusing driving signal FOO″ influenced by the testing signal TEST is inputted into the servo system 24. Then, the servo system 24 adjusts a vertical gap between the OPU 12 and the target track 28 of the optical disk 11 according to the test focusing driving signal FOO″. With an appropriate adjustment, the laser emitted from the OPU 12 is capable of focusing on the track 28 of the optical disk 11. When the frequency of the testing signal TEST varies from the initial value toward the target value for affecting the focusing driving signal FOO, a user can use the tracking error signal TEO and the focusing driving signal FOO respectively received at input ports A, B of the dynamic signal analyzer 42 for analyzing a frequency response associated with the focusing driving signal FOO and the tracking error signal TEO.
Please refer to FIG. 3 in conjunction with FIG. 4. FIG. 3 is a first frequency response diagram associated with the focusing driving signal FOO and the tracking error signal TEO, and FIG. 4 is a second frequency response diagram associated with the focusing driving signal FOO and the tracking error signal TEO. In FIG. 3 and FIG. 4, the horizontal axis stands for the frequency, and the vertical axis stands for the gain. The response curve L2 shown in FIG. 4 corresponds to a standard OPU 12, and the response curve L1 shown in FIG. 3 corresponds to a flawed OPU 12. It is obvious that when the frequency of the testing signal TEST is greater than 10 KHz, the gains corresponding to the response curve L1 are greatly deviated from the gains corresponding to the response curve L2. Taking the frequency F for example, the gain, which corresponds to the frequency F, is equal to 25 through the response curve L1. However, the gain, which corresponds to the frequency F, is equal to 45 through the response curve L2. In other words, the crosstalk inherent to the flawed OPU 12 seriously affects the tracking error signal TEO and the focusing error signal FEO. Therefore, the tracking error signal TEO generated from the OPU 12 is introduced to the focusing error signal FEO generated from the OPU 12, and the unwanted interference couples with the focusing error signal FEO. Similarly, the focusing error signal FEO generated from the OPU 12 is introduced to the tracking error signal TEO generated from the OPU 12, and the unwanted interference couples with the tracking error signal TEO. The OPU 12 with serious crosstalk effect can be filtered out through observing the frequency response associated with the focusing driving signal FOO and the tracking error signal TEO or observing the frequency response associated with the tracking driving signal TRO and the focusing error signal FEO.
In order to diagnose characteristics of the OPU 12, a tester needs an external dynamic signal analyzer 42 and an external mixer 44 shown in FIG. 2. In addition, the dynamic signal analyzer 42 needs to be connected to the OPU 12 and the focusing controller 18, and the mixer 44 needs to be connected to the dynamic signal analyzer 42, the focusing controller 18, and the servo system 24. Concerning the optical disk drivers 10 waiting to be tested, the complicated connection shown in FIG. 2 is repeatedly established for diagnosing the characteristic of the OPU 12 within each optical disk driver 10. When mass production of the optical disk drive 10 begins, the prior art quality assurance (QA) procedure greatly slows actual yield of the optical disk drive 10 owing to the above-mentioned complicated testing mechanism.

Method and related apparatus for diagnosing crosstalk within an optical pick-up unit by utilizing firmware


A video bit stream with pictures comprising inter-coded content can be decoded upon receiving a channel start or file seek instruction. Pictures for beginning decoding and display of the bit stream can be selected based at least in part on one or more tuning parameters that set a preference between a latency of beginning to display video and possible defects in the displayed video. In some embodiments, to implement decoding upon a channel start or file seek, one or more types of data are generated for one or more pictures. For example, picture order counts are generated for pictures after a channel start or file seek operation. As another example, a decoder generates a frame number value that triggers re-initialization of a reference picture buffer before decoding after a channel start or file seek operation.

Digital media, such as video, is sometimes encoded such that a current portion of the encoded media refers to another portion of the encoded media. As an example of inter-picture coding, parts of a current video picture are sometimes encoded by reference to other video pictures that were previously encoded and decoded. The previously encoded/decoded pictures are termed reference pictures. Thus, decoding the current portion depends (to at least some degree) on information in the other portion.
In some cases, the other portion of the encoded media may be partially or completely unavailable. In such cases, it can be difficult or impossible to accurately decode the current portion. Such a situation can arise, for example, when encoded video is delivered over a network connection, and a user switches between channels of video (examples of channel start operations). Or, such a situation can arise, for example, when a user plays back a video file and moves forward or backward in the video (examples of file seek operations). In these scenarios, dependencies of a current video picture on unavailable reference pictures can result in failure of decoding. This can show up as missing blocks on the screen ("macroblocking") or other corruptions in one or more displayed pictures.

Implementing channel start and file seek for decoder


An apparatus and method for forming a three-dimensional object within a block of transparent material by using a laser beam. This is useful in the field of rapid prototype manufacturing (RPM) in which a computer-generated CAD file defining an object may be converted directly to the described object. A CAD surface model is sliced and the data from the sliced model used as input to a numerically controlled machine. Because only the surface of the volume being cut from the solid block must be scanned by the laser beam, this process is much faster than other RPM manufacturing techniques where a laser beam must scan every point inside the shape being formed. Objects having complex geometries and/or hollow interiors may readily be formed using the disclosed apparatus and method.

1. Field of the Invention
The present invention relates to a method for laser cutting. More particularly, the invention comprises a novel method for cutting three-dimensional (3-D) objects from solid blocks by inner cutting. The method is particularly useful for rapidly producing prototypes of solid or hollow shell objects.
Globalization and requirements for customization have brought intensive competition to into the manufacturing field. The requirements for upgrades to existing products as well as the rapid introduction of new products in a competitive market has placed great stress on product developers. To maintain their competitive edge, manufacturers have been forced to seek better ways to create evaluation prototypes of proposed design changes to exiting products as well as totally new products. In recent years, design efforts have been focused on the use of Computer Aided Design (CAD) systems. Methods for directly converting CAD output files into prototypes are very desirable and have been eagerly sought. Starting in the late 1980s, a new field of endeavor, Rapid Prototyping Manufacturing (RPM) first appeared in the United States. The essence of RPM methods is to allow direct conversion of CAD system outputs directly into solid prototypes. One method for accomplishing this process is to xe2x80x9cgrowxe2x80x9d the prototype thereby eliminating the need for molds, fixtures, jigs, fixtures, or other specialized machining equipment. The solid models resulting from this process may then be observed, evaluated, and/or tested. In addition, the solid prototypes may be turned into xe2x80x9chardxe2x80x9d (e.g., metal) parts by precision casting or other similar processes.
There are many different prototyping methods currently available for use. These may be divided into two broad categories. The first involves growing a solid shape by adding material, bit-by-bit in a controlled manner. Examples of this class of method included stereo lithography using a Stereo Lithographic Apparatus (SLA), Selective Laser Sintering (SLS) and Fused-Deposition Modeling (FDM). The second category involves adding materials in thin layers to form the desired shape. These methods are best represented by the Laminated Object Manufacturing (LOM) technique.
In stereo lithography, a CAD 3-D model is first sliced into thin layers using software well known to those skilled in the 3-D modeling arts. A laser beam at an appropriate wavelength is controlled to selectively scan the surface of a pool of photosensitive resin. The result is that the laser beam cures and solidifies the surface layer of the resin on a platform in accordance with the shape of the defined slice of the model currently being processed. The process starts with the bottom layer and, after a layer is defined and cured, the platform is incrementally lowered, the platform travel being defined by the thickness of the computer-generated layers. This allows the liquid resin in the pool to cover the solidifying layer. These process steps are repeated until the desired three-dimensional object is complete.
This process differs from the inventive prototyping process in that while the laser beam scans only the surface of the material being formed into an object, in effect, every point within the volume of the solid being produced must ultimately be scanned. This requires a relatively long time to accomplish and uses large amounts of electrical energy. The inventive process, on the other hand, must only trace the contour of the required solid within a solid volume from which the prototype object is being formed. This requires significantly less time and uses much less energy. RPM is currently a vigorously researched field because it still promises shorting development cycles.
Currently used rapid prototyping technologies have the following limitations: First, process times are deemed excessively long. To make a relatively large part with complex geometry can take a few days to a whole week. The reason for this low productivity lies in the volume scan characteristic of methods of the prior art which require the laser beams to scan every point inside the shape being formed. Typically, the focal point of a laser beam is around 0.1 mm or less. Consequently, the total scanning path will be very long contributing to the long processing time and high-energy consumption.
Second, prototype part precision is usually compromised. Cured layers are prone to warp, especially when in large parts. Also, the contraction of resin during laser curing process in the SLA method as well as possible paper distortion after absorbing moisture in the LOM method may seriously affect the precision of the finished parts.
Third, the necessary equipment required to practice the methods of the prior art are is usually quite complex. All of the rapid prototyping methods described hereinabove invariably require a moving platform which must be specially designed, thus adding to the investment in equipment.
Forth, the complexity of the shapes which may be created using prior art methods is limited. The inner-cutting method of the present invention can, however, follow very intricate geometries in a single surface scan, and is even able to cut out an enclosed shell inside another enclosed shell.
2. Discussion of the Related Art
U.S. Pat. No. 3,715,734 for MEMORY STORAGE DEVICE AND METHOD OF MAKING SAME, issued Feb. 6, 1973 to Jack Fajans, teaches a method whereby a laser may selectively carbonize spots within a block of polymethylmethacrylate. The carbonized spots so formed may later be xe2x80x9creadxe2x80x9d as binary data. FAJANS teaches no method for cleaving a three-dimensional object from within a block of suitable material by means of a dilated, suitably focused laser beam.
Several United States patents have been issued which address the use of a laser to physically change an interior point within a solid which is transparent to the wavelength of the laser. For example, U.S. Pat. No. 4,092,518 for METHOD OF DECORATING A TRANSPARENT PLASTIC MATERIAL ARTICLE BY MEANS OF A LASER BEAM, issued May 30, 1978 to Rene"" Remy Merard; U.S. Pat. No. 5,575,936 for PROCESS AND APPARATUS FOR ETCHING AN IMAGE WITHIN A SOLID ARTICLE, issued Nov. 19, 1996 to Boris Goldfarb; U.S. Pat. No. 5,637,244 for METHOD AND APPARATUS FOR CREATING AN IMAGE BY A PULSED LASER BEAM INSIDE A TRANSPARENT MATERIAL, issued Jun. 10, 1997 to Alexander I. Erokhin; U.S. Pat. No. 5,786,560 for 3-DIMENSIONAL MICROMACHINING WITH FEMTOSECOND LASER PULSES, issued Jul. 28, 1998 to Abdelkrim Tatah, et al.; and U.S. Pat. No. 5,886,318 for METHOD FOR LASER-ASSISTED IMAGE FORMATION IN TRANSPARENT OBJECTS, issued Mar. 23, 1999 to Anatoly Valentinovich Vasiliev, all teach methods for forming a viewable image inside a solid piece of a transparent material. However, none of these patents teaches or suggests a method for forming a three-dimensional, solid or hollow shell shape within a block of transparent material. The instant invention, on the other hand, teaches an apparatus and method whereby a solid object may be completely formed inside a block of a suitable transparent material.
U.S. Pat. No. 4,546,231 for CREATION OF A PARTING ZONE IN A CRYSTAL STRUCTURE, issued Oct. 8, 1985 to Herbert D. Gresser, et al. teaches the use of a laser beam to create a parting zone in a crystalline material such as diamond. An energy-transmissive window is first prepared on the outside of the crystal. This window transmits the energy of a laser beam to successive damage zones, typically adjacent one another whereby the crystal structure is destroyed. The crystal may then easily be fractured along the parting zone created by the successive damage zones. In contradistinction, the instant invention provides for the formation of a solid, three-dimensional object totally within a block of transparent material. There is no reliance on the material being crystalline. The inventive formation process relies upon carbonization of a series of sites within the transparent material which define the surface of the desired three-dimensional object being formed.
U.S. Pat. No. 5,247,923 for METHOD OF FORMING A DIAMOND DRILL BIT ELEMENT USING LASER TRIMMING, issued Sep. 28, 1993 to Maurice P. Lebourg, teaches a method similar to that of GRESSER, et al. described hereinabove. Desired cut lines within a diamond crystal are identified and selectively removed leaving a series of truncated conical structures, eventually, after successive cuts, resulting in a drill bit having a predetermined shape. Unlike the apparatus and method of the present invention, no internal, three-dimensional shape is formed in a solid block of non-crystalline material.
None of the above inventions and patents, taken either singly or in combination, is, however, seen to anticipate or suggest the instant invention as claimed.
The present invention relates to an apparatus and method for forming a solid, three-dimensional object within a block of transparent material by means of a laser beam. This invention is particularly useful in the field of rapid prototype manufacturing (RPM) wherein a computer-generated CAD file defining an object may be converted directly to the described object using the inventive method. Because only the surface of the volume being cut from the solid block must be scanned by the laser beam, the inventive process is much faster than other RPM manufacturing techniques, such as SLA or SLS, wherein a laser beam is required to scan every point inside the shape being formed. This saves large amounts of time and electrical energy over methods of the prior art. In addition, parts having complex geometries and/or part having hollow shells may readily be formed.
Accordingly, it is a principal object of the invention to provide a rapid prototyping method for forming a three-dimensional object within a block of transparent material using a laser beam.
It is another object of the invention to provide a rapid prototyping method using a laser beam wherein all cutting is accomplished in a single scan of the surface of the object being formed.
It is a further object of the invention to provide a rapid prototyping method using a laser beam which can quickly form the desired part using minimum energy.
Still another object of the invention is to provide a rapid prototyping method using a laser beam which requires a relatively small capital investment.
An additional object of the invention is to provide a rapid prototyping method using a laser beam which can produce objects having complex geometries.
It is again an object of the invention to provide a rapid prototyping method using a laser beam which can produce hollow objects.
It is a still further object of the invention to provide a rapid prototyping method using a laser beam which avoids forming the desired object from individual layers of material such as the LOM method, or by accumulating material bit-by-bit, such as the SLA or SLS methods of rapid prototyping.
It is yet another object of the invention to provide a rapid prototyping method using a laser beam which forms object having high strength and good mechanical stability.
It is an additional object of the invention to provide a rapid prototyping method using a laser beam which may be practiced in conjunction with standard numerically-controlled machine tools, such as milling machines and lathes with added laser beam generators and optical systems.
It is another object of the invention to provide a rapid prototyping method using a laser beam wherein the desired part is formed directly from a computer-aided design (CAD) file.
It is an additional object of the invention to provide a rapid prototyping method which can simultaneously forms both positive and negative prototype molds during a single scan.
It is yet another object of the invention to provide a rapid prototyping method which provides an easy correction of focal point location differences caused by the refractive index of the bulk material being machined.
It is a still further object of the invention to provide a rapid prototyping method using a laser beam which is inexpensive to implement and operate and which may be easily used.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.

Rapid prototyping method using 3-D laser inner cutting

East-one block 67-202, Huazhong University of Science and Technology


A storage device comprising a modulation encoder and decoder, an error-correction encoder and decoder, and a metric computation module. The modulation encoder and decoder provide a modulation code for data stored on the storage device. The error-correction encoder and decoder provide an error-correcting code for data to be written on the storage device. The metric computation module is coupled with the modulation decoder to compute conditional probabilities using recovered read-back channel parameters of the storage device.

A wide variety of data storage devices are used today. Some examples include magnetic recording devices such as hard disk drives (HDD) and digital linear tapes (DLT), and optical storage devices such as compact disks (CD) and digital versatile disks (DVD). Based on the developments of the atomic force microscope (AFM), new probe based storage concepts have been introduced over the past few years. Probes having a nanoscale tip have been used for modifying the topography and for scanning an appropriate storage medium. Data are written as sequences of symbols represented by topographical marks, such as indentation marks and non-indentation marks. The tips comprise apexes with a radius in the nanometer range, and the indentation marks have a comparable diameter, for example, a diameter in the range of 20 to 30 nm or even smaller. Hence, these data storage concepts promise ultra-high storage area density.
A storage device for storing data based on the AFM principle is disclosed in "The millipede—more than 1,000 tips for future AFM data storage" by P. Vettiger et al., IBM Journal Research Development, Vol. 44, No. 3, March 2000. The storage device has a read function and a write function based on the mechanical scanning of a storage medium with an array of probes each having a tip. For this purpose, the probes comprise cantilevers that carry the sharp tips on their end sections. Symbols are represented by indentation marks and non-indentation marks in a polymer layer. The probes respond to these topographic changes while they scan the surface of the polymer medium.
Indentation marks are formed on the polymer medium by thermomechanical recording. Writing of an indentation mark is achieved by applying a voltage pulse across two of the cantilever terminals to heat a write heater and tip and, simultaneously, another voltage pulse to the substrate of the polymer medium to create a local force between tip and medium. As a result, a nanometer-sized indentation is formed on the medium, representing an encoded '1' symbol. The absence of an indentation at the position of a topographical mark represents an encoded '0' symbol.
Reading is also accomplished by a thermomechanical concept. A voltage is applied across two of the cantilever terminals, so that a read heater heats up to a temperature that is not high enough to soften the polymer layer as is necessary for writing. The thermal sensing is based on the fact that the thermal conductance between the probe and the storage medium changes when the probe tip is moving in an indentation, as the heat transport is in this case more efficient. As a consequence of this, the temperature of the cantilever decreases and hence also its resistance decreases. This change of resistance is then measured and determines the read-back signal. Reading and also writing the marks is accomplished by moving each probe relative to the storage medium along a line representing a track. The amplitude of a read-back signal is defined as the difference in magnitude between a read-back signal sample that is obtained when the tip of the probe is exactly at an indentation center, and a sample obtained when the tip of the probe is at an indentation-free area of the storage medium, while the probe moves along a track center line. This is also disclosed in "Millipede—a MEMS based Scanning-Probe Data-Storage System", by E. Eleftheriou et al., IEEE Transactions on Magnetics 39(2), March 2003, pp. 938-945, and in "Signal Processing for Probe Storage," by H. Pozidis et al., Proceedings of International Conference on Acoustics, Speech and Signal Processing, Philadelphia, Pa., Mar. 19-23, 2005, pp. 745-748.
The reliability of data retrieval in data storage devices may be improved by employing modulation codes to constrain the sequences that are written on the storage medium. The most popular modulation codes used in conventional data storage devices are the run length limited (RLL) codes. RLL codes are characterized by two parameters, d and k, whereby '1' symbols are constrained to be separated by at least d and at most k '0' symbols. It is customary to refer to RLL codes as (d, k)-constrained codes. Writing at least d '0's between '1's allows to increase the linear recording density by mitigating intersymbol interference, whereas limiting to k the maximum number of consecutive '0's ensures that feedback is provided sufficiently often for timing recovery and gain control loops.
Further, the process of recording and subsequent retrieval of data is likely to introduce errors in the recovered data. These errors are typically related to electronics noise, imperfections in the storage medium surface, and non-ideal recovery of channel parameters during the write and read processes. Errors in the recovered data are corrected using error-correcting codes (ECC). Error-correcting codes add redundancy to the information bits during the encoding operation. This redundancy can be used to correct errors in the recovered data during read operations. Some commonly used ECC for data storage applications are the low-density parity-check (LDPC) codes and the Reed-Solomon (RS) codes. Various decoding algorithms for LDPC codes for practical implementations are known. One such decoding algorithm is disclosed in "Reduced-Complexity Decoding of LDPC Codes", by J. Chen et al., IEEE Transactions on Communications 53(8), August 2005, pp. 1288-1299. To enhance error-correction capabilities and capacity of the device, ECC is usually implemented jointly with data interleaving and RLL (d,k) coding. In this case it is customary to refer to the ECC as the outer code and to the RLL code as the inner code. The data-retrieval process involves making binary hard (threshold) decisions on the read-back channel-output signals, using the detected binary symbols to decode the (d,k) sequences, deinterleaving the (d,k)-decoder binary output symbols to get channel-output codewords for error-correction, and finally decoding the codewords to retrieve the user information bits.
Besides electronics noise and media noise, other impairments that are present in the read-back signal of a recording channel are, for example, random fluctuations of the read-back signal amplitude, and direct-current (DC) offset of the read-back signal. Further, random fluctuations of the time instants at which pulses are applied for writing information on the storage medium, or at which sampling of the read-back signal for conversion from the analog domain to the digital domain takes place, further impair the quality of the read-back signal. The phenomenon of random fluctuations in the timing of the write and read processes is usually known as jitter. In the data-retrieval process described above, making binary hard decisions leads to non-recoverable loss of information. Moreover, hard-decision decoding of the RLL (d, k) sequences introduces error propagation. Furthermore, a hard-decision scheme does not allow iterative soft decoding of an outer error-correcting code. However, conventional soft decoding techniques, as for example proposed for modulation codes in HDD, do not take into account in the decoding process the presence of such channel impairments as jitter, gain fluctuations, offsets, and nonlinear distortion. Timing recovery, gain adjustment, and offset compensation are performed prior to decoding, and the statistical description of related read-back channel impairments is not exploited. A further drawback of the conventional schemes when applied to a probe storage device is that, in the presence of channel impairments such as random variations in read-back signal amplitude, random variations in sampling instants (jitter), and residual DC offset, the probability of a binary decision error when reading a '1' may be significantly larger than the probability of a binary decision error when reading a '0'.
Thus, there is a need for a decoder for the inner code, to obtain near-optimum soft decoding in the presence of random channel impairments without increasing the number of states in the inner decoder, and hence without increasing decoder complexity.

Method of retrieving data from a storage device using a recovered read-back parameter

International Business Machines Corporation


An apparatus and method for demagnetizing a write head of a disc drive. Under control of a clock oscillator, synthetic demagnetizing pulses are generated and applied to a writer-driver bridge. Also under control of the clock oscillator, a write current produced by the writer-driver bridge incorporates the demagnetizing pulses and ramps down to about zero. The train of demagnetizing pulses and the write current ramp down demagnetizes the head, reducing write head magnetic bias that may influence the proximate read head of the disc drive head.

A disc drive storage system 10, illustrated in FIG. 1, comprises a disc 12 further comprising a magnetic material for storing information in the form of binary bits for later retrieval and processing by a computer or processing device. Information is written to the disc 12 by magnetizing magnetic domains within the magnetic material to represent a binary zero or a binary one. The domains retain the magnetization for later retrieval during a disc read operation.
A spindle motor 13 rotates the disc 12 (typically at speeds up to 10,000 revolutions per minute) allowing a read/write head 14 to write or read data as the read/write head 14 flies over an upper surface of the disc 12. The read/write head 14 is affixed to an actuator and suspension arm 16 controlled by a voice coil motor 18 for moving the suspension arm 16 across the upper surface of the disc 12 along an arc extending between a disc circumference 24 and a hub 26. The physical features of the suspension arm 16 cause the read/write head 14 to 'fly' very close to the disc upper surface, as head-to-disc contact is undesired.
Certain head embodiments conventionally comprise two separate transducing elements (not shown in FIG. 1), an inductive writer and a magnetoresistive (MR) reader. Earlier-generation heads utilize a single inductive transducer for both reading and writing. The present application, in the interest of clarity, assumes use of a dual-element head, however the invention is not limited in application to a dual-element head embodiment.
The disc 12 comprises a plurality of concentric tracks 30 (typically 20,000 per radial inch) for interlaced storage of binary-encoded user data in fields 32 and head location data in servo bursts 34. The servo bursts 34 (typically 200 per disc track), which are radially contiguous across the disc 12 and equally-spaced circumferentially along each track, provide feedback information to the read/write head 14 for accurately controlling head position along the track (referred to as track following) and for moving the read/write head 14 rapidly and accurately between tracks (referred to as track accessing).
To write data to the disc 12, the voice coil motor 18 moves the suspension arm 16 to a desired radial position above the surface of the disc 12. The disc 12 is rotated to move a circumferential region to be written under the read/write head 14. Write current is supplied to a coil (magnetically coupled to a magnetically permeable core) of the head's inductive writer to induce a magnetic field in the core. The magnetic field extends from the core across an air gap between the read/write head 14 and the disc 12 to magnetize a small region of magnetic domains to store the data bit. The direction of the magnetic field produced by the head, and thus the direction of the magnetic domains, is dependent on the direction of current flow through the head.
During a data read or a servo read operation, the suspension arm 16 is moved while the disc 12 is rotated to position the read/write head 14 above a magnetized region to be read. A DC (direct current) bias voltage of 0 volts to about 0.3V is supplied to the read/write head 14. The magnetized disc region changes a resistance of the magnetoresistive element in the read/write head 14, generating an output signal comprising a relatively small AC (alternating current) voltage imposed on the DC bias voltage.
The output signal is supplied to a read circuit 40A of a preamplifier 40. From the read circuit 40A, servo data is supplied to a servo read circuit 42A of a recording channel 42; read data bits are supplied to a data read circuit 42B. The servo read operations are interlaced with either a data read or a data write operation, as the servo feedback information is required during both operations to maintain proper position of the read/write head 14. Due to the low signal levels and high-frequency components in the read output signal, the preamplifier 40 is conventionally mounted proximate the read/write head 14, commonly on a circuit board constructed from flexible material.
As is conventional in the art, the preamplifier 40 further comprises a serial port configuration control register 40C that communicates with a controller 54 over a conductor 41 for providing control signals to the configuration control register 40C for establishing operating parameters of the preamplifier 40.
A servo logic circuit 50 receives processed and demodulated servo data from the servo read circuit 42A and translates this information into a format acceptable to a servo DSP (digital signal processing) processor 52 that executes servo control algorithms to control head position and movement according to head location commands received from the controller 54. Control commands supplied by the servo DSP processor 52 are delivered to a voice coil motor power amplifier 56 that in turn controls the voice coil motor 18 to drive the read/write head 14 in a closed feedback loop to maintain the desired head position on the disc 12. A spindle motor power amplifier 57 receives command signals from the servo DSP processor 52 to maintain the spindle speed at typically about 10,000 RPM.
During data read operations, the data read circuit 42B of the recording channel 42 delivers read data to the controller 54 over a buss 62. The controller 54 performs error detection and correction on the read data prior to supplying the data to a user interface, such as an interface to a computer or data processing device (e.g., SATA, SCSI, SAS, PCMCIA interfaces).
To write data to the disc 12, the controller 54 receives data to be written from the user interface for formatting and adding error detection/correction information. The processed data are supplied over a buss 64 to a data write circuit 42C of the recording channel 42. A write gate signal is also supplied by the controller 54 to the data write circuit 42C; from the data write circuit 42C the write gate signal is supplied to the write circuit 40B of the preamplifier 40. The data write circuit 42C also provides a write data signal, that represents the data bits to be written to the disc 12, to the data write circuit 40B. When the write gate signal is asserted, the preamplifier 40 is activated for write mode operation, during which the write circuit 40B causes current supplied to the write element of the read/write head 14 to alternate (i.e., change direction) under influence of the write data signal (representing the data bits to be written to the disc 12) between a positive state (to write a '1', for example) and a negative state (to write a '0', for example). The write current magnetizes the disc 12 to store the data bits. As is known by those skilled in the art, the designation of a positive state as a data '1' and a negative state as a data '0' is arbitrary and can be reversed. As will be described below, deassertion of the write gate signal initiates the demagnetize function according to the teachings of the present invention.
The recording channel 42 further comprises a servo-write circuit 42D that in response to signals received from the servo DSP processor 52, generates servo information for writing onto the disc 12 via the preamplifier write circuit 40B. The servo write circuit 42D is typically active only during manufacture of the disc drive to write servo information 34 on the disc 12.
To increase storage capacity, a disc drive may comprise a plurality of stacked parallel discs 12. A read/write head is associated with each disc to write data to and read user data and servo data from a top and bottom surface of each disc.
Ideally, upon conclusion of a write operation, the inductive write element of the read/write head 14 should not influence the head's MR read element during a subsequent read operation. In practice, however, if the write current in the write element ceases abruptly at the end of a write operation, the inductive writer tends to retain remnant magnetization within its ferromagnetic core, thus creating a residual magnetic field. Due to the proximate location of the MR read element and the inductive write element within the read/write head 14, the remnant magnetization can undesirably bias the read element, possibly distorting the read signal and causing errors in read bits. Demagnetizing (degaussing) the write element after a write operation reduces the remnant magnetization.
A further motivation for demagnetizing the write element is the need to avoid data erasure from the disk 12 by stray magnetic fields. In modern high-density recording, the small bit-cell sizes in the disc 12 are susceptible to thermal agitation. Over many revolutions of the disc, the presence of the residual field within the write element can hasten collapse of the bit-cell magnetization, causing data loss.
To reduce the remnant magnetization, it is desired to demagnetize the inductive writer of the read/write head 14 after a data write operation. This process, also referred to as degaussing, is accomplished by repetitively alternating the head current polarity, causing the inductive write element to switch between a north and a south magnetic pole, while decaying the head current to zero. The switching is accomplished by applying a series of bursts or transitions having a duration T (where T=1/(data frequency)) to the inductive write element. Switching the current direction in a controlled manner over a predefined number of magnetic pole transitions and decaying the head current from its full value (i.e., the current value during a write operation) to zero during the transitions causes the write element to execute successively smaller loops of its MH curve (i.e., the hysteresis curve relating the magnetic field (H) to the magnetization (M)), causing the remnant magnetization to decay to nearly zero. In its effect on the core domain structure of the writer head, the degauss process is analogous to an annealing operation.
Possible implementations of the demagnetizing operation include an analog approach using programmable analog time constants (i.e., time constants derived from resistor/capacitor (RC) components or current-charged capacitors) to provide the head current ramp down. Such an approach requires a synchronizing element to synchronize the current ramp down interval with the bursts or transitions, and is therefore sensitive to on-chip component values that determine the analog time constants. Known degaussing implementations are also limited in their ability to provide an arbitrary shape to the decay profile of the write current during the ramp down interval.

Method and apparatus for write head demagnetization


A transmitter comprising a noise signal generator, a summing element configured to generate a signal as a sum of an output of the noise signal generator and a transmit data signal, and a transmit driver configured to generate an output signal based on the sum. Also, a method of calibrating a signal-to-noise ratio (SNR) for a transmitter comprising transmitting a first signal comprising a data signal with no noise signal, capturing the first signal, transmitting a second signal comprising a noise signal, wherein both an amplitude and a phase of the noise signal have been adjusted by a gain and phase control element, capturing the second signal, and determining the SNR corresponding to the captured first signal and the captured second signal, wherein the transmitter transmits the second signal using a transmit driver.

Bit Error Ratio (BER) is a metric used to evaluate transmission system quality in communications equipment. Communications equipment may be manufactured with a target BER, referring to the BER under the worst-case noise conditions. Since it is desirable for equipment to be manufactured with a noise margin, which is the additional noise required beyond a nominal noise power level to reach the target BER, it is desirable for equipment to be tested in noise conditions that have noise greater than that in the worst-case operating noise environment.
In conventional controlled tests of communications equipment, a data signal is transmitted from a piece of communications equipment and a noise signal may be added to the data signal prior to reception to generate a noisy signal. The noisy signal may be received and the BER measured. The process of adding the noise signal in such a scenario may change the channel seen by the data signal relative to what the equipment would experience in the field. For relatively low speed data, the changes to the channel caused by controlled tests have a negligible effect on the BER as compared with the additive noise.
However, it may not be practical to measure the effects of additive noise in very high speed systems, e.g., systems faster than several gigabits per second (Gbps), and thus, the test scenario described above for testing noise margin has not been popular in the industry for very high speed systems. This is mainly because any noise injection circuitry itself causes additional impairments to the channel such as increasing loss, reflections, and uncontrolled crosstalk and Electromagnetic Interference (EMI). The BER due to these impairments may be significant relative to the BER due to additive noise. Also, an accurate noise margin test is difficult because any added noise level is not easy to control. And finally, there may be no physical space available for auxiliary devices for controlled noise generation once equipment is built for high-density backplanes. Despite these difficulties, there have been noise tolerance tests conducted in laboratories on specially built test boards, but significant differences between the noise environments of the test boards in a lab and the actual deployed systems in the field have rendered the results from such lab testing ineffective for use in accurate product qualifications. Therefore, there is a need for efficient and accurate noise margin tests for systems with data rates over several Gbps.

Controlled noise injection in transmitter for noise margin testing


One example of a test board includes first and second communication ports configured for communication with a master device and a DUT, respectively. A bit error rate tester of the test board is arranged for communication with the master device and with the DUT by way of the first and second communication ports, respectively, and the bit error rate tester includes at least one IC whose maximum data rate is temperature sensitive. Finally, the test board includes a temperature control system arranged to control the IC temperature so that a maximum data rate of the IC can be adjusted through the use of thermal effects.

1. The Field of the Invention
The present invention relates generally to systems, methods, and devices for high speed data transmission. More particularly, embodiments of the present invention concern systems, methods, and devices for increasing the data transmission rate of electronic devices.
2. Related Technology
Computer and data communications networks proliferate in a variety of technological, business, and other environments due to an increase in the performance of computer and network equipment and an increased demand for communication bandwidth. Communications networks, such as wide area networks ("WANs"), local area networks ("LANs"), metropolitan area networks ("MANs"), and storage area networks ("SANs") allow increased productivity and utilization of distributed computers or stations through the sharing of resources and the efficient transfer of data and other information.
As the demand for and use of computer and data communications networks increases, the demand for improved network capabilities also increases. For example, communications networks with increased data transmission rates are in high demand. Technological, commercial, and industrial enterprises place a premium on the ability to transmit and receive information across communications networks at the highest possible rates. Therefore, developments in communications network technology, including developments in electrical devices used in a communications network, are extremely valuable.
In order to provide devices with increased performance capabilities, methods for improving the performance of network devices are continually evolving and improving. One way in which the performance of electrical devices used in communications networks can be improved is by cooling the devices. Manufacturers of electrical devices cool the electrical devices so that the temperature of the device falls within a temperature range known to correspond to relative improvements in the performance of the device. Such cooling may increase the data transmission rate for electrical devices used in communications networks, and thereby contribute to enhancement of the performance of such networks.
The method of increasing the data transmission rate of electrical devices by cooling the temperature of the devices to a temperature within a certain range has proven effective and has therefore gained wide acceptance. Correspondingly, industrial standards and ranges for temperatures to be used in networks concerned with high data transmission rates have been developed. For example, one industrial range of temperatures corresponding to high data transmission rates in integrated circuits is approximately −40° C. to +85° C., while a commercial range is approximately 0° C. to 70° C. By ensuring that the temperature of electrical devices remain within an appropriate recommended range, the data transmission rate of the device can be enhanced.
However, while cooling electrical devices to temperatures within a recommended range enhance the performance of the electrical device, there remains an interest in achieving yet further increases in data transmission rates of electrical and optoelectronic devices.

Temperature control in an integrated circuit


Inexpensive stainless steel and inexpensive and high strength stainless steel which has excellent hydrogen environment embrittlement resistance even if used in a hydrogen resistant environment in over 40 MPa high pressure hydrogen gas or a hydrogen resistant environment in liquid hydrogen, characterized by containing, by mass %, C: 0.1% or less, Si: 0.4 to 1.5%, Mn: 8 to 11%, Cr: 15 to 17%, Ni: 5 to 8%, Cu: 1 to 4%, and N: 0.01 to less than 0.15% and having a balance of Fe and unavoidable impurities, having a volume rate of δ-ferrite of 10% or less, and having a long axis of δ-ferrite before annealing of 0.04 to 0.1 mm.

In recent years, from the viewpoint of global warming, to suppress the exhaust of room temperature effect gases (CO2, NOx, and SOx), progress has been made in development of technology which uses hydrogen as energy. In the past, when storing hydrogen as high pressure hydrogen gas, thick-walled Cr—Mo steel tanks have been filled with hydrogen gas up to about pressures of about 40 MPa.
However, tanks made of such Cr—Mo steel fall in fatigue strength due to fluctuations in inside pressure and penetration by hydrogen due to repeated filling and release of high pressure hydrogen, so the wall thickness must be made 30 mm or so. The weight therefore builds up. For this reason, the increase in weight and increase in size of the equipment become serious issues.
The existing JIS standard SUS316-based austenite stainless steel (hereinafter referred to as "SUS316 steel") has a hydrogen embrittlement resistance under a high pressure hydrogen gas environment which is better than other steel for structural use, for example, carbon steel, including the above Cr—Mo steel, and JIS standard SUS304-based austenite stainless steel (hereinafter referred to as "SUS304 steel"), so is being used for piping materials or high pressure hydrogen fuel tank liners of fuel cell vehicles as well.
SUS316 steel is stainless steel which contains expensive Ni: 10% or more and Mo: 2% or more. For this reason, SUS316 steel has major problems in general applicability and economy (cost).
Further, to store and transport a large amount of hydrogen gas, making the pressure of the hydrogen gas a high pressure of over 40 MPa and making active use of liquid hydrogen may be mentioned. Regarding the increase in pressure, for example, to use piping made of SUS316 steel in an over 40 MPa high pressure hydrogen gas environment, the point has been raised that it would be necessary to increase the currently 3 mm wall thickness piping to over 6 mm thickness or the piping would not be able to withstand use strength-wise.
For ultralow temperature use of liquid hydrogen, in the past, austenitic SUS304 steel or SUS316 steel has been used. For liquid hydrogen containers as well, low temperature hydrogen gas embrittlement has to be considered at the top layer part where the liquid hydrogen becomes vapor, so it is preferable to use SUS316 which is excellent in hydrogen embrittlement resistance.
Further, in recent years, in advance of the introduction of fuel cell vehicles, progress has been made in official building of prototypes of hydrogen stations and running of proving tests. Hydrogen stations which store large amounts of hydrogen as liquid hydrogen and which can raise the liquid hydrogen in pressure and supply it as over 70 MPa high pressure hydrogen gas are also in the proving stage. As the world moves to commercial use and popularization of such hydrogen stations, the need for an inexpensive metal material reduced in Ni and Mo and an inexpensive and high strength metal material which are able to be used in both hydrogen environments of high pressure hydrogen gas and liquid hydrogen has been becoming stronger.
In the past, high nitrogen-content austenitic stainless steel has been known as stainless steel for high pressure hydrogen gas use which is raised in material strength.
For example, PLT 1 discloses stainless steel for high pressure hydrogen gas use which contains N: 0.1 to 0.5%, Cr: 22 to 30%, Ni: 17 to 30%, Mn: 3 to 30%, and any of V, Ti, Zr, and Hf and which satisfies 5Cr+3.4Mn≦500N and containers and equipment comprised of that steel.
Furthermore, PLT 2 discloses stainless steel for high pressure hydrogen gas use which contains N: 0.1 to 0.5%, Cr: 15 to 22%, Ni: 5 to 20%, Mn: 7 to 30%, and any of V, Ti, Zr, and Hf and which satisfies 2.5Cr+3.4Mn≦300N and containers and equipment comprised of that steel.
The stainless steels which are disclosed in these PLT 1 and PLT 2 are directed to higher Cr and higher Ni compared with SUS316 steel. In the stainless steel which is disclosed in PLT 2 with a relatively small content of alloy elements as well, substantially the amount of Cr is over 17%, the amount of N is over 0.25%, and Ni, Mn, Mo, Nb, etc. are contained making it high alloy steel.
PLT 3 discloses a pressure vessel and pipe for piping use which are excellent in hydrogen environment embrittlement resistance and stress corrosion cracking resistance and which can be used for 70 MPa or more high pressure hydrogen gas without depending on a larger wall thickness and larger diameter. The steel which is used for these pressure vessel and pipe for piping use is comprised of a composition of ingredients of Cr: 15 to 20%, Ni: 8 to 17%, Si: 1.3 to 3.5%, Mn: 3.5% or less, and N: 0.2% or less.
PLT 4 discloses austenitic stainless steel welded pipe which is suitable for transport of 40 MPa or so high pressure hydrogen which is made of stainless steel containing Cr: 14 to 28%, Ni: 6 to 20%, Si: 4% or less, Mn: 3% or less, and N, 0.25% or less.
The stainless steels which are disclosed in PLT 3 and PLT 4 feature addition of Si and reduction of Mn and contain Ni in amounts of substantially 9 to 15% or about the same as or more than SUS316 steel.
The inventors proposed in PLT 5 austenitic high Mn stainless steel which has workability which enables cold working, deep drawing, and other press forming by a high working rate and is maintained in nonmagnetic property without formation of strain-induced martensite even after working. This stainless steel has trace amounts of Ni: 6% or less and Mo: 0.3% or more added and is remarkably superior in economy compared with SUS316 steel.
Furthermore, the inventors proposed in PLT 6 an austenitic high Mn stainless steel for high pressure hydrogen gas use which is intended for application in low temperature hydrogen gas environments and is inexpensive or both inexpensive and high in strength. This austenitic high Mn stainless steel pursues thorough reduction of alloying and as a result recommends addition of Cr: less than 15%, Ni: 6% or less, N: 0.01 to 0.4%, and a 0.35% trace amount of Mo and defines a parameter Md30 of austenite stability of −120 to 20 in range.
However, this austenitic high Mn stainless steel not only does not consider high pressure hydrogen gas, but also does not consider adaptation to a liquid hydrogen environment. The material properties under the ultralow temperature of liquid hydrogen are unknown.
Therefore, as explained above, no inexpensive stainless steel or inexpensive and high strength stainless steel which can be used in both hydrogen environments of over 40 MPa high pressure hydrogen gas and liquid hydrogen has yet appeared.

Austenitic high Mn stainless steel and method production of same and member using that steel

Nippon Steel & Sumikin Stainless Steel Corporation