Systems and methods for the automated positioning of pads and orienting of slot templates for the pads. The systems and methods also include automated adjustment of well path plans from a pad to selected well targets.

Historically, the positioning of onshore pads has involved a number of issues related to proper pad positioning. In the oil and gas industry, for example, proper positioning of onshore pads for oil and gas rigs requires consideration of surface topography and slope constraints. In addition, the orientation of slot templates, which are located on each pad and are used to organize the location of each well on the pad, must also be considered. Finally, each well path—sometimes referred to as a plan from the pad to a selected well target—must be considered.
For example, large scale onshore field development planning creates unique problems for oil and gas companies. Unconventional and tight gas pays generally contain large numbers of subsurface targets to exploit. A direct result is a large number of wells that must be planned and drilled from surface pads or sites, which are analogous to offshore platforms. In order to adequately plan for this, several objectives must be accomplished. The number and location of surface pads or sites required to complete the development is required, for example, which depends on the number of wells that will be drilled from each pad, the engineering constraints placed on the individual well paths (i.e. maximum reach, dogleg severity, inclination angle, etc.), the location of the subsurface targets and the topographic constraints—such as elevation and grade. Slot template geometry and the orientation for each pad also need to be defined. Slot templates generally involve very tight spacing between slots, which requires an understanding of the well paths that will originate from each slot so that collision risk between wells is minimized. And, well paths need to be assigned to the correct slot. Individual well paths may also need to be altered in order to minimize interference with other wells planned or drilled from the same, or different, slot template(s).
The main issue with each objective is the planning cycle time. Planning for 50 pads with 20 wells per pad (i.e. 1000 total wells) can be a tedious, iterative-process subject to trial and error. For instance, a pad is visually positioned over a grouping of targets by visualizing a topographic map. Elevation is eyeballed, estimated and used as the starting reference point elevation. Well locations for the proposed slot template geometry must then be calculated and each individual well path must be assigned to a slot and designed. During the well path design process, it may be determined that the site positioning just did not work due to well path constraints and the process is repeated over and over again until it is successful. At this time, each individual well path must be altered to minimize collision risks with other wells that will be drilled from the same or other sites. The aforementioned process would realistically take anywhere from 3-5 days for just one pad. Multiply this process by 50 and the length of time required becomes significant.
One method for determining platform placement that is most often used may be thought of as a "move and calculate footage" based method. In this method, a series of wellpath plans are created manually, one at a time, using dogleg, inclination, reach, and anti-collision as the planning criteria for the platform location. The cumulative measured depth traversed by the many wellpaths is summed and used as a measurement of the base case location.
Once the wellpaths are created, the well planner then moves the surface location of the base case platform a fixed distance, usually in one of the four compass directions, and recalculates the cumulative measured depth. If the cumulative measured depth decreases from the base case measurement, the well planner knows that there is a potential location which is "better" than the base case location. The planner then goes through many iterations moving the platform location by different distances and to different compass directions from the base case location looking for the best location based on the total calculated footage of the wellpaths that will be required to drill from the wells to the platform location.
The above-mentioned methodology has a number of drawbacks. For example, it is tedious, time consuming, and requires fixing the number of plans and targets to be reached. Using this methodology, it is not unusual for well planners to spend three to four weeks on just one project.
Other automated methods for platform placement use Monte-Carlo or random number based statistical calculations for platform placement and take into account producers vs. injectors, cost of processing facilities, and existing pipelines. They, however, do not take into account target weighting, which is addressed in U.S. Pat. No. 7,200,540. The '540 Patent, which is assigned to Landmark Graphics Corporation and is incorporated herein by reference, further addresses the need for a method that varies the number and locations of platforms and optimizes the targets used if the resultant platform set provides a plan that: a) reaches more targets; b) reaches the same number of targets with less distance; or c) reaches the same number of targets, but includes targets with higher weighting values based on the reservoir parameters. In short, the '540 Patent describes systems that implement methods for selecting a set of platform locations, determining additional platform locations, and determining an optimum location for each platform location in the set of platform locations.
The '540 Patent, however, does not address the need to utilize surface topography for automatically extracting pad elevations after positioning when working on large scale onshore field development planning, especially in mountainous regions. Additionally, the '540 Patent does not address the ability to update existing pad elevations using a surface grid or the ability to restrict the placement of pads based on slope constraints.
There is also a need, which is not met by the prior art and which will reduce the risk of collision, to optimize slot template orientations by aligning them on strike with the surface elevation model or rotating them based on the planned trajectories. Due to the tight spacing of slot templates, there is also a need to optimally assign plans to the proper slots and to stagger kick-offs and nudge individual plans.

Systems and methods for improved positioning of pads


A method and a packet data network for providing broadcast/multicast services (BCMCS) to a mobile terminal (MT). The method receives at a Dynamic Host Configuration Protocol (DHCP) server from the MT, for requesting an IP address of a primary BCMCS controller that serves the packet data network. The method retrieves the IP address of the primary BCMCS controller and responds to the MT with a response message from the DHCP server to the MT, the response message includes the IP address of the primary BCMCS controller. Next, the MT uses the IP address of the primary BCMCS controller and sends a Hyper Text Transfer Protocol (HTTP) request message from the MT to the primary BCMCS controller for requesting BCMCS services, the HTTP request message including a location information and an access type indicator of the MT. Afterwards, a list of available BCMCS programs is provided to the MT.

1. Field of the Invention
The invention relates to a method for providing packet data services to a user of a mobile terminal (MT).
2. Description of the Related Art
A user of a MT may subscribe to packet data services in a packet data network. In particular, the user may subscribe to receive broadcast/multicast service (BCMCS).
BCMCS services are intended to provide flexible and efficient mechanism to provide multimedia services to subscribers. One of the objectives for this service is to send the same information to multiple users. The transmitted information could be packet data such as text, voice and streaming media. As of today, a BCMCS controller delivers BCMCS services directly to the MT or via a packet data service node (PDSN). The PDSN is responsible for supporting authentication mechanisms and a configuration option to allow a terminal to receive Internet Protocol (IP) services such as VoIP (Voice over IP) and more generally voice/data multimedia over a wireless cellular network.
BCMCS subscription is associated with BCMCS programs provided by a BCMCS content provider (e.g. News Channel, Sports Channel), not the content (media type such as music, video, etc.). The subscriber selects a desired program and therefore selects the type of content he wishes to receive.
Furthermore, a transmission territory for each BCMCS program can be independently defined. BCMCS programs may be transmitted to all or selected zones of a packet data network. These zones constitute the transmission territory. The BCMCS programs may be received by all users or may be restricted to a group of subscribers via encryption.
The subscriber that wishes to receive BCMCS programs from a BCMCS capable network may discover the BCMCS controller that provides information of the available programs within the transmission territory where the subscriber is located. In particular, the subscriber may discover via its MT the BCMCS controller in the packet data network that provides the requested programs. Some solutions have tried to encompass the above problem.
A BCMCS controller may also be retrieved via mechanisms other then those provided by the BCMCS controller. These mechanisms may be via Wireless Access Protocol (WAP) or via Short Message Service (SMS) sent to the subscriber. Therefore, one of the existing solutions is to have only one BCMCS controller in the network and to provide an IP address that BCMCS controller to the MT via Internet.
Another solution allows only one BCMCS controller for a network and further populate during a PPP session establishment the IP address of the BCMCS controller. Alternatively, another solution could be to have multiple BCMCS controllers and further populate the corresponding IP addresses of these BCMCS controllers to the MTs located in the packet data network.
However, these solutions involve an amount of data that is not scalable in a packet data network and require that a Domain Name Server (DNS) application at the MT to be link layer agnostic for allowing a host such as the MT and a network to authenticate each other for network access to the MT. Consequently, this results in having a link breaks the IP layering rules for transmitting IP packets over specific link layer protocols. Therefore, there is a need to provide a solution for providing an IP address of a BCMCS controller to the MT in scalable way while maintaining the criteria of selecting a BCMCS controller for an MT without breaking the IP layer rules and in a way to be used for any access type.

Method for discovering a broadcast multicast services (BCMCS) controller in a packet data network


Provided are an apparatus and method for negotiating a frame offset between a Base Station (BS) and a Relay Station (RS) in a wireless communication system using a multi-hop relay scheme. A communication method of a superordinate station includes, upon detecting an initial access of an relay station, determining an offset value between a frame number used in the superordinate station and a frame number to be used in the relay station; generating a message including RS frame offset information corresponding to the offset value; and transmitting the generated message to the relay station. Accordingly, since the base station and the relay station share the frame offset, the base station can transmit a specific broadcast message in advance to the relay station by considering the frame offset, and the relay station can transmit data, which has to be transmitted in synchronization with the base station at the same time point or at the same frame number, to a Mobile Station (MS) at an exact time point.

In the next generation communication system, also known as the 4th Generation (4G) mobile communication system, a cell has a significantly smaller radius in order to provide high-speed communication and to handle a large amount of call traffic. Currently, a wireless network is designed based on a centralized design. However, it is expected that the centralized design cannot apply to the 4G communication system. Therefore, the 4G communication system has to be controlled in a distribution manner and also has to be able to actively cope with changes in environments, for example, when a new base station (BS) is added. For the aforementioned reason, a self-configuration wireless network is required in the 4G communication system.
In order to realize the self-configuration wireless network required in the 4G communication system, a technique applied in an ad-hoc network is introduced in the wireless communication system. A representative example thereof is a multi-hop relay cellular network in which an ad-hoc multi-hop relay scheme is introduced in a cellular network which is constructed of a fixed BS.
FIG. 1 illustrates a structure of a conventional cellular network using a multi-hop relay scheme.
Referring to FIG. 1, a mobile station (MS) 110 included in a BS coverage area 101 is connected to a BS 100 with a direct link, and an MS 120 located out of the BS coverage area 101 and therefore having a poor channel state with the BS 100 is connected to the BS 100 via a relay station (RS) 130. In this case, since the RS 130 serves to relay a signal between the BS 100 and the MS 120, a BS-MS link, a BS-RS link, and an RS-MS link are formed. For example, when an MS is located in a cell edge of the BS 100 or in a shadow area suffering a serious shielding phenomenon due to buildings, the MS communicates with the BS 100 via the RS 130. As such, a high-speed data channel can be provided by using a multi-hop relay scheme in a cell edge region having a poor channel state, and it is also possible to expand a cell service area.
The broadband wireless access system generally provides an Internet service, a Voice over Internet Protocol (VoIP) service, a non-real time streaming service, etc. In addition, recently, a Multicast and Broadcast Service (MBS), which is a real-time broadcast service, was recognized as a new service. Advantageously, the MBS can provide bidirectional data communication and also support the same mobility as a Digital Multimedia Broadcasting (DMB) service. The MBS can provide a video broadcast service (e.g., news, soap opera, sports, etc.) and a data service (e.g., radio music broadcast, real time traffic information, etc.).
According to a service access method of an MS, the MBS is classified into two categories, that is, a single-BS access method and a multi-BS access method. In the single-BS access method, the MS receives an MBS service from one BS to which the MS is registered. In the multi-BS access method, the MB receives the MBS service simultaneously from two or more base stations.
FIG. 2 illustrates a multi-BS access method.
In the multi-BS access method, when an MS is located in an overlay area between a currently serving cell and a neighboring cell, a signal of the neighboring cell dose not act as noise caused by interference but acts as a signal gain resulted from radio frequency (RF) combining. This is a macro diversity effect. In order to obtain the macro diversity effect, the same signal is transmitted from a serving BS and a BS located in the neighboring cell. Therefore, to provide the MBS, all base stations and all relay stations exiting within a broadcast zone (i.e., MBS_ZONE) transmit the same signal.
When a BS has data (e.g., MBS data) to be transmitted at a specific time point, the BS considers a processing delay which occurs in an RS, and thus transmits the data to the RS before the specific time point. By doing so, even when the RS experiences the processing delay, for example, to analyze the received data or to allocate a bandwidth for retransmission, the BS and the RS can transmit the same data at the same time point.
For example, when the data is transmitted through two-hops, the BS transmits the data in advance by considering not only a first-hop RS but also a second-hop RS. In this case, in consideration of the processing delay occurring in the second-hop RS, the first-hop RS directly connected to the BS buffers the data, and transmits the data to the MS at a predetermined time point.
Meanwhile, the broadband wireless communication system may cause interference in UpLink (UL) communication when neighboring base stations use the same frame number at the same time point. For this reason, in order to increase a system capacity or coverage, the neighboring base stations need to use different frame numbers from one another. The same also apply to a system using a relay scheme. Hence, it is preferable that base stations and relay stations use different frame numbers at the same time point. In this case, if a frame number cannot be differentiated between a BS and an RS, a problem may occur in which a message to be transmitted at the same time point or at the same frame number is transmitted by the BS and the RS at a different time point or at a different frame number. Therefore, when the different frame number is used between the BS and the RS, there is a need for a signaling process capable of negotiating a frame offset between the BS and the RS.

Apparatus and method for negotiating frame offset between base station and relay station in broadband wireless communication system using multi-hop relay scheme


The present invention provides a detachable add-on card unit to a host system that combines mass storage capability and a processor on the same card. The card can receive data from the host, process the data, and store it in processed form, as well as the reverse process of retrieving stored data, processing it, and supplying it to the host. The non-volatile mass storage memory may contain program storage as well as card system data and user data. The end user of the card can program applications into the program storage. The combination of mass storage and a processor also adds to the capabilities of the on-card processor, allowing the card to store and execute programs. The present invention is able to provide a programmable add-on card unit to a host system. A number of applications can be stored in the card's mass storage and loaded as needed by the on-card micro-controller.

1. Field of the Invention
The present invention relates to digital media, and more particularly to digital media such as cards and modules and combinations. Particularly, the present invention relates to an add-on card unit detachably coupled to a host unit where the card unit contains mass data storage and is capable of providing additional processing power to the host unit.
2. Background Information
In recent years, there are a variety of add-on cards and modules developed for use in digital systems such as personal computers ("PC"). They have enjoyed a measure of success in various memory-intensive applications. Some of these memory add-on cards use flash memory, and are known as flash memory cards. Flash memory cards have become widely used for mass data storage applications, and are a popular alternative for conventional add-on card implemented non-volatile memory solutions such as rotating hard disks and battery-backed SRAM, especially for notebook computers, personal data assistants ("PDA"), and some high-end digital cameras. As an alternative to rotating hard disk PC cards, flash memory cards are more rugged and space efficient, are silent, consume less power, provide higher performance (in most cases), and provide a removable form-factor. As an alternative to battery-backed SRAM PC cards, flash memory cards typically offer higher-densities and lower cost per bit and are not as limited by reliability and temperature issues associated with batteries used in the battery-backed SRAM PC cards.
Generally, these memory cards perform only auxiliary storage functions for the host systems. In some cases, some simple data processing functions are performed in this card. There are currently various standards on these PC cards developed by different vendors. Each of these memory card standards defines a card type that is able to perform some storage functions. The following is a brief summary of various standards in the memory cards industry
Flash PC cards are compliant with the Personal Computer Memory Card International Association ("PCMCIA") standard. While flash PC cards can provide sufficient amounts of memory for a broad range of applications, they have not been widely accepted for use in applications such as mobile and portable electronics, or for use in applications having significant cost sensitivity. PC cards simply tend to be too large for many portable applications such as pagers, voice recorders, mobile telephones, and hand-held meters. In addition, PC cards are also too bulky and heavy for carrying in a pocket or wallet, as would be desirable for many consumer applications.
An example of a PC card that adds functionality to the host system is described in U.S. Pat. No. 6,047,342 of Depew. The device of this patent receives data from the host, operates on the data, and returns the processed data to the host. This system provides no mass storage on the card and stores the data being processed only in RAM for buffering purposes.
Compact flash card is a small format flash memory card that was initially announced by SanDisk Corporation in 1994. The compact card supports the IDE/ATA interface standard by means of an on-card ATA controller IC. Memory capacity of up to 256 Megabytes is currently available. Both 5 volt and 3.3 volt power supplies are supported. A compact flash card is interfaced to notebook computers and PDAs by inserting the card into a special PC card adapter.
Miniature card is a small format card that was initially announced by Intel Corporation in 1995. The miniature card supports a linear addressing range of up to 64 Megabytes of memory using a 16-bit data bus. The miniature card specification allows for flash, DRAM and ROM memory types. Both 5 volt and 3.3 volt power supplies are supported by the specification. A miniature card is interfaced to notebook computers and PDAs that support the standard PC card interface with a special PC card adapter. A miniature card specification is described in Miniature Card Specification, Release 1.0, February 1996, available from Intel Corporation of Santa Clara, Calif.
Solid state floppy disk card, or SSFDC, is a small format card initially announced by Toshiba Corporation in 1995. The SSFDC has 22 flat contact pads, some of which are I/O pads for both address and data input and output as well as for command inputs. The card specification is dedicated to byte serial NAND-type flash memory. The specification accommodates 5 volt or 3.3 volt power supplies. An SSFDC is interfaced to notebook computers and PDAs that have the standard PC card interface with a special PC card adapter. An illustrative device is type TC5816ADC, which is described in Preliminary TC5816ADC Data Sheet No. NV16030496, April 1996, available from Toshiba America Electronic Components, Inc. of Irvine, Calif. The device is said to be suitable for such applications as solid state file storage, voice recording, image file memory for still cameras, and other systems which require high capacity, non-volatile memory data storage
Siemens Components of Cupertino, Calif. has described a device known as MultiMediaCards, or MMC; see Portable Design, July 1996, p 23 et seq. The original MultiMediaCard package had 6 edge-mounted contact pads and users a serial bus. This format has been extended into a 7 pin format as described in "The MultiMediaCard System Specification" produced by the Technical Committee of the MultiMediaCard Association (MMCA). The specification accommodates a various range of voltage supply. The device is suitable for such applications as games, talking toys, automobile diagnostics, smart phones, PDAs (tailored operating systems or special programs), and notebooks through a PDA adapter. These cards provide mass non-volatile storage, but lack processing capabilities. The MultiMediaCard design has been further developed as the Secure Digital, or SD, card. This design adds additional data pins and security features to the MultiMediaCard package.
Integrated Circuit (IC) card format and the similar Identification (ID) card format, commonly known as smart cards, were introduced in the mid 1980's and have been standardized by the International Organization for Standardization, Identification Cards—Integrated Circuit Cards with Contacts, Part 1: Physical Characteristics, Document No. ISO 7816-2, May 1988; and International Organization for Standardization, Identification Cards—Integrated Circuit Cards with Contacts, Part 3: Electronic Signals and Transmission Protocols, Document No. ISO 7816-3, September 1989. Smart cards are credit card sized and typically contain a microcontroller with a small amount, on the order of a few kilobytes, of EEPROM memory. The cards are popular in Europe and are making inroads into the U.S. market. Primary application are smart telephone calling cards and stored value cards, the later application being promoted by credit card companies like Visa and MasterCard as a replacement for paper currency. Although these cards have some processing ability on the card, it is not available to the user and does not let the user add ability to the combined system. Any processing ability is fixed by the card's issuer along with the initial data prior to the user receiving the card. The smart card system does not execute any additional functions for the user and are just for the secured storage of data, either for security uses or for keeping a stored value, and the processing ability of the card is relegated to managing these functions based on the issuer's determination. This allows for a secure link only between the card and the host.
Another low memory capacity card format is known as the Subscriber Identification Module ("SIM"), which is used in conjunction with mobile telephones based on the Global System for Mobile Communication ("GSM") standard. The SIM specification is set forth in a publication of the European Telecommunication Standard Institute entitled European Digital Cellular Telecommunication System, Global System for Mobile Communications, Phase 2: Specification of Subscriber Identity Module—Mobile Equipment Interface, Document No. GSM 11.11 Reference (RE/SMG)—091111PR3, ICS 33.060.50 December 1995. SIMs offer only a very limited amount of memory, typically less than one kilobit. However, this small amount of memory is sufficient to provide a GSM mobile phone with secure identification of the GSM subscriber, and may also hold a small amount of data for call metering, phone number storage, and in some cases very short data messages (less than a few hundred bytes of data). The plug-in SIM typically is housed in a small hinged smart card connector similar to the type CCM03 available from ITT Cannon Corporation of Santa Ana, Calif. The small form factor allows the GSM SIM to be placed inside the phone as a plug-in module.
Other memory technologies have not been widely used in insertable/removable memory modules and cards because of their inherent shortcomings relative to such successful technologies such as flash memory. For example, battery-backed SRAM or DRAM memories require supplemental battery power when the main power is removed, while flash memory is non-volatile (no battery is needed) and is more reliable over temperature. Flash memory is available in higher densities and at lower cost/bit than SRAM and EEPROM memory, and is cost-competitive with DRAM memory.
In some cases, data processing is performed on the data before being transmitted to the PC card for storage. In these cases, data is processed in the host unit and then transmitted from the host unit to the card unit for storage. For example, data can be encrypted in the host and then the encrypted data is sent to the memory card for storage. Another example is data being compressed in the host and then sent to the memory card for storage.
FIG. 1 shows a conventional system having data processed by the host unit and then transmitted to the PC card for storage. As shown in the figure, the system comprises two units: a host unit 160 and a card unit 100, for example a standard MultiMediaCard or SD card. Generally, the host unit can be a consumer apparatus such as a cellular phone, a PDA, a Palm Pilot, or a personal computer. The host unit 160 comprises a processor 162 and other supporting components, such as a host memory 163, a timer 164, and a number of other standard elements not shown here. Furthermore, the host unit further comprises a card interface 161 for communicating with the card unit 100. The host interface 161 can be implemented using any of the above-mentioned protocols defined by the various manufacturers or associations.
As shown in FIG. 1, the card unit 100 generally comprises a host interface 141, memory storage and, in some cases, an on-card micro-controller. For the example shown, the host interface 141 of the card unit is used for communicating with the host unit 160. The on-card micro-controller 131 is used to control the loading of data from the host unit to the memory storage. In addition, the controller is designed for handling memory functions such as addressing and buffering. The controller 131 and host interface 141 are connected to the card bus 153, to which may also be connected some non-programmable ROM memory 123 for program storage and a RAM memory 121, usually volatile, that can act as a cache, as described for example in U.S. Pat. No. 5,418,752 and U.S. Pat. No. 5,172,338, which are both hereby incorporated by this reference. The mass storage memory 111, that will be FLASH memory on an MultiMediaCard or SD card, is not connected directly to the bus 153, but is instead connected through 155 to mass storage interface 115, which is in turn connected to bus 153. The mass storage interface 115 serves as a "non-linear" or "non-random" access interface for controlling the FLASH memory where data is stored in a non-linear fashion. The contents in the mass storage memory 111 can not be addressed randomly by the controller 131, or, more accurately, can only be accessible in blocks that are too large for the controller to utilize without first reading out and caching the whole block.
However, the system design as shown in FIG. 1 suffers from performance problems when data is required to be processed (e.g. compression/decompression and/or encryption/decryption) before being stored in the memory storage. The data processing usually requires intensive mathematical computation that can greatly degrade the performance of the processor in the host unit. Additionally, operating sequences stored on the card are in ROM 123. In a actual card, the physical size of the ROM 123 portion is relatively quite large and costly, so that the number of operating sequences that can be stored are restricted by the desire to minimize the amount of ROM.


An electro-optic device including an optical waveguide formed in an electro-optic material that propagates an optical signal along a first direction of propagation is described. The device also includes an electrical waveguide formed in the electro-optic material and positioned co-linear relative to the optical waveguide and in electromagnetic communication with the optical waveguide, where the electrical waveguide also propagates the electrical signal in the first direction of propagation. A compensation network is electrically coupled to the electrical waveguide at a junction and propagates the electrical signal in a second direction of propagation that is substantially non-co-linear with the first direction of propagation. In operation, the compensation network modifies at least one of a phase or an amplitude of the electrical signal at the junction relative to a phase or an amplitude of the accumulated modulation on the optical signal at the junction, respectively, and then returns the modified electrical signal to the electrical waveguide.

The invention relates generally to the field of optical modulation and, in particular, to methods and apparatus for high-speed external optical modulations.
Optical modulators impress or modulate RF (or microwave) electrical signals onto a light beam in order to generate a modulated optical beam that carries data. Modulators either directly modulate the optical beam as it is generated at the optical source or externally modulate the optical beam after it has been generated. Direct modulation is typically accomplished by modulating the drive current of the optical source. An integrated electro-absorptive modulator can modulate the optical intensity of light leaving the source as well.
External modulation can be accomplished by using an external modulator that is separate from the optical source. External modulation is advantageous because it can modulate signals over a very wide bandwidth. External modulators are typically voltage-controlled devices that include a traveling-wave electrode structure, which is positioned in close proximity to the optical waveguide. The electrode structure produces an electric field that overlaps the optical waveguide over a predetermined distance (the interaction length) and causes an electromagnetic interaction which modulates the optical signal.
Lithium niobate (LN) electro-optic external modulators are increasingly being used to modulate data on optical signals that are being transmitted at very high data rates and over long distances. Lithium niobate modulators are advantageous because they can modulate optical signal over a broad frequency range, they modulate optical signals with minimal optical frequency shift (frequency xe2x80x9cchirpxe2x80x9d), and they operate over a broad wavelength range. These features are particularly desirable for Dense Wavelength Division Multiplexing (DWDM) broadband optical communication systems that transmit optical signals with many optical wavelengths through a single optical fiber.
Modulators used for transmission at high speeds and over long distances must be efficient to avoid the use of expensive electronic amplifiers and digital drivers. In addition, modulators need to be compact in order to minimize the required space on the transmitter card.
Lithium niobate crystals have an inherent mismatch between the velocity of optical and electrical signals propagating through the crystal which impacts modulation efficiency. The RF propagation index is significantly higher than the optical refractive index of lithium niobate. That is, the lithium niobate crystal slows the RF signal relative to the optical signal so that it takes the RF signal a longer period of time to travel over the interaction distance. Thus, the RF signal becomes out-of-phase with or xe2x80x9cwalks offxe2x80x9d the optical signal. Consequently, the modulation becomes inefficient. The longer the interaction distance, the greater the inefficiency. Using a buffer layer can minimize velocity walk-off, however, the required interaction length is long.
FIG. 1 illustrates a top view of a prior art electro-optic device 10 that compensates for the velocity mismatch between the optical and electrical signals propagating through the device by using phase reversal sections that are co-linear with the optical waveguide. The device 10 includes an optical waveguide 12 and RF electrodes 14 that are positioned in zero degree phase sections 16 and in phase reversal sections 18. The phase reversal sections 18 periodically flip the RF electrodes 14 to either side of the optical waveguide 12 to produce a 180 degree phase shift in the RF signal relative to the optical signal. The RF electrodes 14 are positioned to alternate between the zero degree phase shift sections 16 and the 180 degree phase shift sections 18. The length of the zero degree phase shift sections 16 is chosen so that the RF signal xe2x80x9cwalks offxe2x80x9d the optical signal approximately 180 degrees before it is flipped 180 degrees in the phase reversal sections 18.
FIG. 2 illustrates a top view of a prior art electro-optic device 30 that compensates for the velocity mismatch between the optical and electrical signals propagating through the device 30 by using co-linear but intermittent interaction sections. The device 30 includes an optical waveguide 32 and RF electrodes 34 that are positioned to alternate between an interaction region 36 and a non-interaction region 38 relative to the optical waveguide 32. The length of the interaction region 36 is chosen so that the RF signal xe2x80x9cwalks offxe2x80x9d the optical signal by as much as 180 degrees of phase shift before it is routed away from the optical waveguide 32 in a co-linear direction and into the non-interaction region 38. The length of the non-interaction region 38 is chosen so that the RF signal becomes phase matched with the optical signal at the end of the non-interaction region 38.
One disadvantage of prior art electro-optic devices that compensate for the velocity mismatch between the optical and electrical signals propagating through the device is that they have relatively low modulation efficiency per unit length. This is because the phase of the RF signal is modified with co-linear sections that are positioned at intervals of 180 degrees. When the difference in phase between the RF and optical signals approaches 180 degrees, the incremental increase in modulation depth with incremental change in electrode length approaches zero. Therefore, the total length of the device must be increased in order to achieve the required modulation. Increasing the length of a lithium niobate device increases the size of the package containing it, which is undesirable, because of the limited space on the transmitter board. State-of-the-art DWDM systems have stringent space requirements due to their high channel count. In addition, more expensive and larger power supplies must be used because higher drive voltages are required.
It is therefore a principal object of this invention to provide an electro-optic device that includes a compensation network that modifies at least one of the phase or the amplitude of the electrical signal relative to the phase or amplitude of the accumulated modulation on the optical signal without introducing significant loss or decreasing the modulation efficiency. It is another principle object for such a compensation network to compensate for velocity mismatch between the electrical signal and the optical signal. It is another principle object for such a compensation network to compensate for the effects of external perturbations in the substrate of the modulator, such as the effects of temperature on a lithium niobate substrate. It is another principle object for such a compensation network to be removably attached to the device to facilitate modifying the frequency response of the device. It is yet another principle object of the present invention to construct a modulator with such a compensation network that is used in conjunction with prior art broadband modulator to form a combined modulator that is capable of producing bandwidth extension of the broadband modulator into the narrow band modulator region.
A principal discovery of the present invention is that an electro-optic device can be constructed with a compensation network that temporarily directs the electrical signal in a path that is in a non-co-linear direction relative to the direction of propagation of the optical signal and that such a compensation network has numerous advantages over the prior art. For example, such a compensation network can modify the phase of the electrical signal relative to the optical signal in order to minimize the effects of velocity mismatch, while introducing very low loss. Such a compensation network can also compensate for the effects of external perturbations on the electro-optic device. In one embodiment of the invention, such a compensation network is used to construct a modulator that provides more efficient modulation per unit length of electrode.
Accordingly, the present invention features an electro-optic device that includes an optical waveguide that is formed in an electro-optic material such as lithium niobate. The optical waveguide propagates an optical signal along a first direction of propagation. An electrical waveguide is also formed in the electro-optic material and is positioned co-linear relative to the optical waveguide and in electromagnetic communication with the optical waveguide. The electrical waveguide also propagates an electrical signal in the first direction of propagation.
In addition, the electro-optic device includes a compensation network that is electrically coupled to the electrical waveguide at a junction. The compensation network propagates the electrical signal in a second direction of propagation that is substantially non-co-linear with the first direction of propagation. In one embodiment, the compensation network includes at least one of an all-pass electrical network, an inductor-capacitor xe2x80x9cPixe2x80x9d network, traveling wave coupler, filter, and transmission line transformer.
The compensation network is designed to modify at least one of the phase or the amplitude of the electrical signal at the junction relative to the phase or the amplitude of the accumulated modulation on the optical signal at the junction, respectively, and then return the modified electrical signal to the electrical waveguide. The compensation network may be a time delay network or a phase delay network.
In one embodiment, the compensation network is a phase delay network that modifies the phase of the electrical signal so that an electro-optic response of the device is increased. In another embodiment, the compensation network is a phase delay network that modifies the phase of the electrical signal so that an electro-optic phase at the junction is substantially equal to an electro-optic phase at an input of the electrical waveguide.
In yet another embodiment, the compensation network is a phase delay network that modifies the phase of the electrical signal at the junction relative to the phase of the accumulated modulation on the optical signal at the junction by a predetermined delay that is variable over a range from zero to one hundred and eighty degrees. In this embodiment, the phase of the electrical signal at the junction relative to the phase of the accumulated modulation on the optical signal at the junction may be modified to be substantially one hundred and eighty degrees.
One advantage of the compensation network of the present invention is that the electrical loss per unit length can be designed to be significantly lower than the electrical loss per unit length of the electrical waveguide to minimize RF losses. Another advantage of the compensation network is that it may be removably attached to the electro-optic device so that it can be replaced by another compensation network with different characteristics. Another advantage of the compensation network is the temperature dependence of the compensation network can be made to be inversely proportional to the temperature dependence of the electro-optic material so as to compensate for temperature non-linearity in the electro-optic material.
The present invention also features an electro-optic modulator that includes a plurality of compensation networks. The optical waveguide is formed in an electro-optic material such as lithium niobate. The optical waveguide propagates an optical signal along a first direction of propagation. An electrical waveguide is formed in the electro-optic material and is positioned in a co-linear direction relative to the optical waveguide and in electromagnetic communication with the optical waveguide. The electrical waveguide also propagates an electrical signal in the first direction of propagation. Each of the plurality of compensation networks are electrically coupled to the electrical waveguide at one of a plurality of junctions. Each of the compensation networks propagates the electrical signal in a second direction of propagation that is substantially non-co-linear with the first direction of propagation.
In operation, each of the plurality of compensation networks modifies a phase of the electrical signal at a respective junction of the plurality of junctions relative to a phase of the accumulated modulation on the optical signal at the respective junction by a predetermined delay and then returns the modified electrical signal to the electrical waveguide. The predetermined delay is variable over a range from zero to one hundred and eighty degrees and, in one embodiment of the invention, the predetermined delay is substantially one hundred and eighty degrees. In another embodiment, each compensation network modifies the phase of the electrical signal at the respective junction relative to the phase of the accumulated modulation on the optical signal at the respective junction so that an electro-optic response of the device is increased.

External optical modulation using non-co-linear compensation networks


A resolver unit having a structure in which the axial length is shortened to prevent the magnetic coupling characteristic between the rotary and stationary sides from being impaired, a winding generates more magnetic fluxes, and multiplexing is easily conducted, and also a resolver using such a resolver unit are provided.

1. Technical Field of the Invention
The present invention relates to a resolver unit which detects a rotational position, and a resolver using it, and more particularly to a resolver unit which has transformer windings, and in which the axial length is shortened, and a resolver using it.
2. Description of the Related Art
FIG. 6 shows a related art resolver comprising transformer windings for a power supply.
FIG. 6 is a fragmentary sectional view of the related art resolver having a cylindrical stator assembly, and a rotor assembly which is placed coaxially with the cylindrical stator assembly.
In FIG. 6, the resolver 100 comprises the cylindrical stator assembly 101, the rotor assembly 102 which is placed coaxially with the stator assembly 101, and a transformer portion 103.
The transformer portion 103 has an inner core 104, and an outer core 105 which is placed coaxially with the inner core.
A stator portion has a structure in which the outer core 105 and the stator assembly 101 are axially built in a cylindrical housing 106.
A rotor portion has a structure in which the inner core 104 and the rotor assembly 102 are axially built in a shaft 107.
In the transformer portion 103, a winding of the inner core 104 is connected to a rotor winding of the rotor assembly 102 by a crossover wire. Winding portions of the resolver are coaxially placed. In order to prevent the shaft from being eccentric, therefore, two bearings 108 are placed with being axially separated from each other.
In the example shown in FIG. 6, the inner core 104, the rotor assembly 102, and the two bearings 108 are continuously disposed in the axial direction. Consequently, the axial length is prolonged, and the stator assembly 101 and the rotor assembly 102 which are cylindrically placed, and the inner core 104 and the outer core 105 have a complicated structure, thereby causing a problem that the whole resolver cannot be miniaturized.
In order to shorten the axial direction, therefore, a disk type resolver or a flat type resolver has been proposed (for example, JP-A-8-136211 and JP-A-5-010779, hereinafter referred to "JPA'211" and "JPA'779" respectively).
FIG. 7 is a sectional view of a related art flat type resolver which is described in below.
In FIG. 7, the stationary side has a stationary core 111 and a stationary sheet coil 113.
The stationary core 111 comprises a magnetic plate 112 which is made of a material having an excellent high-frequency iron loss characteristic, such as disk-like ferrite.
The stationary sheet coil 113 is fixed to a side face of the magnetic plate 112 by an adhesive agent or the like. In the stationary sheet coil 113, a primary winding 114 of a rotary transformer portion A, and a detection winding 115 of a signal generating portion B are formed from a flat plate-like conductor by a printed wiring produced with etching, printing, or a press work, and bonded to the front and rear faces of a disk-like insulating substrate made of polyimide. An insulating process using a polyimide resin or the like is applied over the surface of the conductor.
The rotary side has a rotary core 116 and a rotary sheet coil 118, and is fixed to a shaft 119. The rotary core 116 is a disk-like core which is opposed to the stationary core 111 via an air gap, and comprises a magnetic plate 117 in the same manner as the stationary core 111.
The rotary core 116 is fixed to the shaft 119 at the center, and supported via a bearing 121 by a bracket 120 fixed to the stationary core 111.
The rotary sheet coil 118 is fixed to a side face of the magnetic plate 117 by an adhesive agent or the like. In the rotary sheet coil 118, a secondary winding 122 of the rotary transformer portion A, and an exciting winding 123 of the signal generating portion B are similarly formed by a printed wiring, and bonded to the front and rear faces of a disk-like insulating substrate 124 made of polyimide. An insulating process using a polyimide resin or the like is applied over the surface of the conductor. In the case where the fixation of the stationary core 111 and the stationary sheet coil 113, and that of the rotary core 116 and the rotary sheet coil 118 are conducted by an adhesive agent, the adhesive agent has a thickness of about 25 μm, and hence the magnetic air gap is increased. This causes the power consumption to be increased.
The related art flat type resolver of FIG. 7 has the following problems.    (1) In the case where the fixation of the stationary core 111 and the stationary sheet coil 113, and that of the rotary core 116 and the rotary sheet coil 118 are conducted by an adhesive agent, the adhesive agent has a thickness of about 25 μm. Therefore, the stationary sheet coil 113 may be attached with being inclined with respect to the face of the stationary core 111 by a thick layer of the adhesive agent, or the rotary sheet coil 118 may be attached with being inclined with respect to the face of the rotary core 116 by a thick layer of the adhesive agent. In such a case, the gap between the rotary and stationary sides cannot be made uniform, and there is a problem in that the magnetic coupling characteristic between the rotary and stationary sides is distorted by a degree corresponding to the inclination.    (2) The surface of each conductor is provided with the insulating process using a polyimide resin or the like. Therefore, the thickness of the resin layer on the conductor causes the gap between the rotary and stationary sides not to be uniformly formed, and the axial length between the rotary and stationary sides is prolonged. Consequently, there is a problem in that the magnetic coupling characteristic between the rotary and stationary sides is impaired.    (3) The primary winding 114 of the rotary transformer portion A, and the detection winding 115 of the signal generating portion B are supported on the magnetic plate 112, and the secondary winding 122 of the rotary transformer portion A, and the exciting winding 123 of the signal generating portion B are supported on the magnetic plate 117. Magnetic members forming the magnetic path are restricted to only the magnetic plates 112 and 117 on the both sides.
Therefore, the distance from the winding on one side to the magnetic plate on the other side is relatively long. When the number of rotations is decreased and the output power of the transformer is reduced, consequently, magnetic fluxes crossing the magnetic plates 112 and 117 are hardly produced. Hence, a magnetic path which forms magnetic fluxes effectively interlinking with the secondary winding 122 and the detection winding 115 is insufficient, and leakage magnetic fluxes are increased.
Since each winding is formed from a flat plate-like conductor by a printed wiring produced with etching, printing, or a press work, the number of turns cannot be increased. Therefore, it is difficult to increase magnetic fluxes generated by the winding.
Consequently, it has been requested to develop a resolver in which the axial length is shortened so as not to impair the magnetic coupling characteristic between the rotary and stationary sides, and a winding generates a large number of magnetic fluxes. JP-A-57-052639 (hereinafter referred to "JPA'639" shows an example which serves as a reference.
FIG. 8 is a view showing the configuration of the example disclosed in JPA'639.
In a resolver 130 of FIG. 8, a rotary transformer 131 and a resolver body 132 are concentrically placed around a rotation shaft 133 with placing the rotary transformer in the inner side and the resolver body in the outer side, thereby reducing the thickness of the resolver 130. A rotor portion 134 of the rotary transformer 131 is fixed to the rotation shaft 133, and a stator portion 135 is fixed to an annular stator portion support member 138 which is inwardly projected from an end plate portion 137 of a case 136. A rotor portion 139 of the resolver body 132 is fixed to a rotor portion support member 140 which is supported integrally by the rotation shaft 133, and a stator portion 143 of the resolver body 132 is fixed to the case 136. The rotor portion support member 140 comprises a disk portion 141 fixed to the rotation shaft 133, and an annular portion 142 which is continuously disposed on the circumference of the disk portion 141.    (1) In the resolver of FIG. 8, in the direction from the center axis to the radially outer side, the rotor portion 134 of the rotary transformer 131 disposed on the rotation shaft 133, the stator portion 135 of the rotary transformer 131 disposed on the stator portion support member 138, the rotor portion 139 of the resolver body 132 disposed on the rotor portion support member 140, and the stator portion 143 of the resolver body 132 disposed on the case 136 are placed in this order. In this configuration, gaps are produced between the rotor portion 134 of the rotary transformer 131 and the stator portion 135, between the stator portion support member 138 and the rotor portion support member 140, and between the rotor portion 139 of the resolver body 132 and the stator portion 143. These gaps are hardly kept to respective appropriate values because the number of the gaps is large.    (2) In order to supply the electric power generated in the rotary transformer 131 to an exciting coil of the resolver body 132, a coil winding of the rotor portion 134 of the rotary transformer 131 is connected to that of the rotor portion 139 of the resolver body 132 by a crossover wire.    The crossover wire is extended along the rotor portion support member 140. Since the length of the crossover wire is large, the crossover wire is susceptible to the wind pressure during rotation, and also to vibrations during rotation. Therefore, damage such as breakage easily occurs in the crossover wire.    (3) In order to couple the rotor portion 139 of the resolver body 132 and the rotor portion 134 of the rotary transformer 131 in a predetermined relationship, the rotor portion 139 of the resolver body 132 is disposed on the rotor portion support member 140, the rotor portion 134 of the rotary transformer 131 is disposed on the rotation shaft 133, and the rotor portion support member 140 and the rotation shaft 133 are coupled together.
As the minimum configuration for forming a resolver, a configuration where the case 136 in which the stator portions 135, 143 are disposed, and the rotor portion support member 140 in which the rotor portions 134, 139 are disposed, and the rotation shaft 133 are coupled together is required. Even when multiplexing is considered on the basis of the minimum configuration, such multiplexing is hardly realized because means for coupling the rotation shaft is problematic.


A hoop stress relief mechanism is disclosed for use on a rotary body to relieve stress caused by both thermal and centrifugal forces. The mechanism may consist of a J-shaped slot cut from the outer rim of the rotary body a distance inwardly toward the axis of rotation, the slot having a curve in its inward end that curves back towards the outer rim. The J-shaped slot may extend through the rotary body to join its two faces. The J-shaped slot may be fabricated by an electric discharge wire machine. The electric discharge wire machine may make multiple passes in order to smooth the bottom surface of the curved slot portion.

The present invention generally relates to articles of manufacture and methods of fabrication for mechanisms to relieve hoop stress in rotating bodies and, more specifically, to a J-slot modification to a rotating disk having integral cast blades such as those contained in a gas turbine engine.
Hoop stress is defined as a load measured in the direction of the circumference of a rotating body, the load being created by thermal gradients and centrifugal forces acting in a radial direction outwardly from the axis of rotation of the body. Such stress is particularly acute in the art of gas turbine engine design where the turbine disks may have integrally cast blades. Such turbine disks have been observed to develop fractures along the circumference of the disk during use.
A number of methods were devised to prevent such fractures. Initially a series of circumferential slots were fabricated into the outer edge of the disk and extending inwardly, the slots being produced using an electric discharge wire machine (EDM). The slots were observed to develop fractures at the inner end nearest the axis of rotation during use, so that a relief hole was drilled at the inner end of the slot to prevent further fracturing. The relief hole was observed to promote increased hot gas ingestion through the disk, so that a rivet or pin had to be inserted through the hole to block such gas ingestion.
This particular prior art hoop stress relief mechanism is shown in FIGS. 1 and 2. According to FIG. 1, a prior art hoop stress relief mechanism is shown as fabricated into a section of rotary body 100 with integral blades 110. A slot 120 may be cut into the rotary body 100 radially from an outer rim 130 to intersect with a hole 140. The slot 120 and hole 140 extend through the rotary body 100 so that the face 150 and the opposing face (not shown) of the rotary body 100 may be connected. A rivet 160 shown in phantom line may be inserted into the hole 140 and secured, so that hot gasses impacting face 150 may be prevented from flowing through the hole 140 to the opposing face of the rotary body 100. Fabrication of the prior art hoop stress relief mechanism as shown may comprise the steps of drilling hole 140 through face 150 of the rotary body 100, using an EDM to fabricate a continuous slot 120 from the outer rim 130 to the hole 140, and deburring and reaming the hole 140 so that any gouges in the walls of hole 140 may be prevented from serving as sites for fractures in the rotary body 100. Referring to FIG. 2, a plurality of prior art slots 120 and holes 140 are fabricated between blades 110 around the circumference of the rotary body 100 so that hoop stress may be reduced and evenly distributed about the entire circumference of the outer rim 130.
The method for fabricating this hoop stress relief mechanism involves a number of manufacturing steps. Referring to FIG. 1, the hole 140 must be first drilled through the rotary body 100 and then reamed to remove any objectionable grooves or defects in the hole walls that formed in the drilling process. Next, the slot 120 must be machined from the outer rim 130 of the rotary body 100 to intersect the hole 140. A rivet 160 must then be installed in the hole 140 to inhibit the flow of hot gasses through the hole 140 thus formed. These steps are used to fabricate the hole-and-slot configuration about the outer rim 130 of the rotary body 100, and then the rotary body 100 is spun and balanced. The rivets 160 must then be inspected after the spinning operation to ensure that they are still properly seated and not deformed by the centrifugal force generated by the spin operation.
However, there are a number of problems associated with this mechanism: First, the method of fabricating the hoop stress relief mechanism involves a detailed sequence of operations that must be precisely executed. This sequence consists of drilling a hole of exact proportions through the disk, reaming the hole to eliminate ridges and grooves within the walls of its bore, cutting an EDM slot from the rim of the disk to the hole, inserting a rivet through the hole to prevent hot gas ingestion from an adjacent space, and inspecting the rivet for correct installation and placement. This sequence is labor intensive, time consuming, and exacting, and thus expensive.
Second, the rivet inserted into the drilled hole is frequently dislodged by vibration, thermal shock, or mechanical means during use. The rivet thus released can cause downstream damage within the turbine. Also, hot gases may subsequently leak through the turbine disk and reduce engine efficiency.
A third problem is that rivets have varying tolerances, so that when installed, they present a balancing problem. As the turbine rotates more rapidly, rivets that are mismatched as to size, weight, or placement along the circumference of the disk start producing unacceptable vibration. Too much vibration can cause the entire turbine to fail.
A fourth problem is that there are variations between different tools used to fabricate the holes and slots, which must be accounted for. For example, in a test, 24 holes were drilled with a 0.120″ drill, reamed with a 0.128″ reamer, and finally finished by four 0.1315″ reamers (6 holes each) to determine if tool variation was significant. An analysis of variance of the surface finish as a function of the block (final reamer) yielded a p-value <0.05, that is, the confidence is greater than 95% (p-value is a statement of probability where confidence=1−p-value). This test showed that the reamer/tool is significant and influences the surface finish. Mean surface finish for each tool ranged from 9.8Ra to 25.9Ra. Therefore, hole-drilling quality is limited by tool variation and is a problem in production fabrication. Current hole drilling processes impart detrimental flaws to the inner diameter surface of the rivet hole; these flaws can serve as sites at which fractures are initiated.
A number of similar methods have been found in the prior art to relieve hoop stress in various engine parts. U.S. Pat. No. 3,781,125 teaches the use of a keyhole shaped slotted portion in the outer shroud structure of a nozzle vane structure for a gas turbine engine. The keyhole shaped slot reduces stress due to larger temperature gradients. A threaded sealing member, instead of a rivet, is inserted into the keyhole to restrict gas flow. However, this application is made for a non-rotating shroud, and not for a turbine disk, and therefore does not experience the same problems as would be experienced by a rapidly rotating turbine disk.
U.S. Pat. No. 4,536,932 teaches a method of forming a turbine disk having integral blades from a plate shaped forging preform A plurality of slots is formed between the integral blades, and the slots are then closed by the forging process. A rod or wire may be inserted at the base of each slot to increase the radius at the end of the slot. However, this process is amenable only to forging processes and does not address machining issues regarding the slot bases.
U.S. Pat. No. 5,071,313 teaches the use of T-shaped relief slots of a shroud body of a gas turbine engine. The relief slots are made in the outer portion of a non-rotating shroud for relief from thermal stress and not for centrifugal stress, where balancing and uniformity of the slots is a concern. The teaching is made for a non-rotating shroud, and not for a turbine disk, and therefore does not experience the same problems as would be experienced by a rapidly rotating turbine disk. The teaching does not discuss any considerations in the fabrication of the slots.
As can be seen, there is a need for a mechanism for relieving hoop stress in a rapidly rotating turbine disk structure, where the mechanism is simple to fabricate, does not allow excessive passage of hot gasses through the turbine disk, does not employ rivets which may become dislodged through use, and does not depend upon uniformity of the machining tools used to fabricate the mechanism.

Hoop stress relief mechanism for gas turbine engines


The object is to provide a water/oil repellent composition which can simultaneously perform a water/oil treatment and a polishing treatment to leather products such as leather shoes, etc., by using one water/oil repellent composition, and can also exert excellent water/oil repellent effect and excellent polishing effect. It is constituted so that microcapsules, in which a polishing agent is encapsulated, are dispersed in a water/oil repellent agent.

The present invention relates a water/oil repellent composition, more particularly to a water/oil repellent composition containing microcapsules in which a polishing agent is encapsulated. When the water/oil repellent composition of the present invention is used in a waterproofing treatment of leather products such as leather, etc., a water/oil repellent agent can permeates through leather to exert satisfactory water repellency and oil repellency. Also, when the leather surface is polished by using a dry cloth after permeation of the water/oil repellent agent and further drying, excellent gloss, i.e. polishing effect can be exerted.
To impart the water repellency and oil repellency to leather products, a method of dissolving a water/oil repellent component such as fluororesin, etc. in a solvent, applying the resultant on leather, followed by drying to evaporate the solvent has generally been used, heretofore. To further improve the resulting water repellency and oil repellency in such a water/oil repellent composition, various compositions have been suggested. For example, the present applicant has suggested a composition for treating leather, a woven fabric and a cellulose material to impart high water/oil repellency to them, comprising (i) a fluorochemical compound represented by the formula: RF-Q-A [wherein Rf represents a fluoro aliphatic portion, A represents an aliphatic portion and Q represents an organic group] and (ii) a vehicle, in Japanese Patent Publication No. 2516889. When this water/oil repellent composition is used in the treatment of leather, not only durable water/oil repellency is imparted to leather, but also there can be obtained such an effect that an adverse effect is not exerted on appearance, touch, hand feeling and other desirable qualities of leather.
To exert the polishing effect in leather products such as leather shoes, etc. various polishing agents such as solid wax, paste, emulsion, etc. have hitherto been suggested. In case of all these conventional polishing agents, the polishing effect is obtained by directly applying them on the leather surface and polishing the leather surface using a drying cloth.
Furthermore, a method used exclusively to simultaneously exert the water/oil repellent effect and polishing effect in the leather products includes a method of using a two-component composition, i.e. a method of applying a solvent water/oil repellent agent product first, drying and wiping it by using a cloth and then applying a polishing agent and polishing by using a dry cloth. In this method, an operation of two steps is essential and long labor hour is required. Therefore, it is desired to provide a water/oil repellent agent product capable of treating in one step.
As the water/oil repellent agent product capable of treating in one step, a product obtained by directly adding silicone oil to the water/oil repellent composition is placed on the market. However, sufficient effect can not be obtained in view of the polishing effect and a further improvement is desired.
An object of the present invention is to solve the above problems of the prior art, and to provide a water/oil repellent composition which can simultaneously perform a water/oil treatment and a polishing treatment to leather products such as leather shoes, etc., by using one water/oil repellent composition, and can also exert excellent water/oil repellent effect and excellent polishing effect without requiring long time in the treatment.
The present inventors have intensively studied to accomplish the above object. As a result, the present inventors have found that the expected effect can be accomplished by dispersing microcapsules, in which a polishing agent is encapsulated, in a water/oil repellent agent in a water/oil repellent composition containing the water/oil repellent agent as a main component.
As described above, the water/oil repellent composition of the present invention contains a water/oil repellent agent as a main component, particularly characterized in that microcapsules, in which a polishing agent is encapsulated, are uniformly dispersed in the water/oil repellent agent.
In the present invention, since the encapsulized polishing agent is dispersed in the water/oil repellent agent, it is possible to avoid the following disadvantages caused by directly dispersing the polishing agent in the water/oil repellent agent. That is, when the water/oil repellent agent permeates through leather, the polishing agent permeates through leather, simultaneously, and it becomes impossible to apply a sufficient amount of the polishing agent on the leather surface. Accordingly, the polishing effect can not be expected. And besides, the polishing agent penetrated through leather, together with the water/oil repellent agent, inhibits the water/oil repellency. Furthermore, when the amount of the polishing agent in the composition added increases, the phase separation occurs. When the phase separation has occurred, it becomes impossible to uniformly apply the composition to the leather products any longer.
Accordingly, the microcapsules, in which the polishing agent is encapsulated, used in the water/oil repellent composition according to the present invention are not specifically limited, as far as the above disadvantages are avoided. That is, the polishing agent-encapsulated microcapsules are not specifically limited as far as the polishing agent encapsulated in the microcapsules does not elute in a solvent contained in the water/oil repellent composition and a protective film of the microcapsules is stable in the solvent. For example, the protective film constituting the microcapsules is preferably a film of a polycondensate formed by polymerization, more preferably a film of a polycondensate such as aminoplast resin, etc. Among these films, a urea-formaldehyde condensate can be advantageously used. The polishing agent-encapsulated microcapsules can be formed by utilizing a publicly known encapsulization technique.
The polishing agent to be encapsulated in the microcapsules includes normal polishing agents, and is not specifically limited as far as the polishing effect is exerted. Taking the process of encapsulization into consideration, it is necessary that the polishing agent must be oil-soluble. Preferred examples thereof include paraffin wax, silicone oil, wax, natural fats and oils, but are not limited thereto. Such a polishing agent is normally used in the amount of 50 to 99% by weight based on the total weight of the microcapsules.
The shape and size of the microcapsules vary widely, but is preferably spherical. The size, particularly diameter (outer diameter of the protective film) is normally within the range from 50 to 2500 xcexcm, preferably from 100 to 1500 xcexcm. When the size of the microcapsules is too large, the microcapsules are broken only by applying a small pressure and the contents come out inadvertently. On the other hand, when the size is too small, the strength of the film is too strong and, therefore, the contents can not come out only by applying a moderate pressure. When the size of the microcapsules is too large or too small, uniform dispersion of the microcapsules can not be accomplished.
The polishing agent-encapsulated microcapsules are used in the water/oil repellent composition in the amount which satisfies the amount of the polishing agent required in single application of the water/oil repellent composition, or which secures to apply a desirable amount of the polishing agent on the leather products.
Furthermore, according to the present inventors"" knowledge, the water/oil repellent agent used as the main component is preferably thickened so as to accomplish uniform dispersion of the microcapsules in the water/oil repellent composition. Examples of a suitable thickening means include use of dispersing agents such as thickener, etc., in combination. Examples of a suitable thickener include a polymer compound, which is soluble in the solvent or can be swollen in the solvent, and a compound, which can form a pseudo-network by ion bonding, for example, mixture of a polyvalent metal and an alkyl acidic phosphate, but are not limited thereto.
The water/oil repellent agent, in which the polishing agent-encapsulated microcapsules are dispersed, is not specifically limited as far as the water/oil repellent agent can dissolve in the solvent and does not cause an adverse effect such as discoloration, etc. when applying on leather and, furthermore, sufficient water/oil repellency can be imparted. Examples of a suitable water/oil repellent agent include fluorine-contained acrylic copolymer, reaction product of fluorine-contained alcohol and fatty acid, perfluoroethylene oxide multimer, etc. Such a water/oil repellent agent is normally used in the state of being dissolved in an organic solvent. Examples of a suitable organic solvent include chlorinated hydrocarbon such as tetrachloroethane, trichloroethane, etc., hydrocarbon solvent such as isoparaffin hydrocarbon, etc., alcohols such as isopropyl alcohol, etc., ketones such as methyl ethyl ketone, etc., or a mixture thereof.
The water/oil repellent composition of the present invention may contain additives, which are normally used, such as softeners, antioxidants, nutrients, perfumes, antibacterial agents, antifungal substances, deodorants, etc., if necessary, in addition to the water/oil repellent agent as the main component and polishing agent-encapsulated microcapsules. The amount of these additional active components and additives added can vary widely according to the desired results.
The water/oil repellent composition of the present invention can be applied by various procedures when using in the treatment of leather products such as leather shoes, etc. For example, a preferred procedure is shown below. First, the water/oil repellent composition is applied on the surface of the leather product to permeate the water/oil repellent component through leather. In this applying operation, an applying means such as brush, etc. may be used. Alternatively, an applying means (e.g. sponge, etc.) attached to the top portion of a vessel containing the water/oil repellent composition may be preferably used. As a result of permeation of the water/oil repellent composition, excellent water/oil repellency can be imparted to leather. At this stage, almost all of the polishing agent-containing microcapsules in the water/oil repellent composition are remained on the leather surface. After the solvent is evaporated or dried, the polishing agent-containing microcapsules remained on the leather surface are broken by rubbing with a dry cloth to release the encapsulated polishing agent on the leather surface. At the same time, by rubbing the released polishing agent with the same dry cloth as that used in the previous operation, remarkable gloss can be imparted to the leather surface.
The present invention will be described in more detail with reference to the following examples. It will be appreciated that the present invention is not limited to the following examples.


A metal enclosure (5) is provided on a mobile phone. The mobile phone includes the enclosure, a rear cover (4), and an electronic component assembly. The enclosure is formed as a single piece, and comprises a top wall (51), a bottom wall (54), and a periphery wall (53) between the top and bottom walls. The walls cooperatively define an opening (57) at a rear end of the enclosure. The electronic component assembly is received in the enclosure, and the rear cover covers the opening. The mobile phone is thus completed. Because the enclosure has no joints, it is strong enough to withstand considerable shock. In addition, it provides excellent protection from EMI. Furthermore, it has a smooth attractive appearance.

1. Field of the Invention
The present invention relates to enclosures for portable electronic devices, and particularly to a one-piece metal enclosure for a portable electronic device and a method for forming the enclosure.
2. Related Art
With constant development of information technology, portable electronic devices such as mobile phones and personal digital assistants (PDAs) have become very popular. These devices each have an enclosure for accommodating and supporting electronic components therein. The enclosure can be made of plastic material or metallic material. Plastic material has many advantages such as low weight, low cost, ease of manufacture, and corrosion-resistance. However, plastic material is relatively fragile, and does not provide good protection from electromagnetic interference (EMI).
An enclosure made of metallic material is strong and provides superior EMI protection. A conventional metal enclosure comprises a front cover and a rear base that are connected together at mechanical joints. Gaps are defined between the cover and the base, which reduce EMI protection. In addition, the cover and the base are liable to be dislodged from each other when the enclosure is subjected to shock. Furthermore, assembly of the cover and the base is unduly laborious. A conventional metal enclosure is disclosed in U.S. Pat. No. 6,229,993. The enclosure includes a front cover and a rear base which are joined at overlapping portions thereof. A skirt portion around a periphery of the front cover is shaped to receive and overlap a peripheral edge of the rear base, to thereby form the enclosure. However, a small gap still exists between the front cover and the rear base.
An improved enclosure that overcomes the above-mentioned problems of the related art is desired.

Metal enclosure for portable electronic device


The invention relates to an electrically programmable memory cell comprising a memory transistor having a source and a drain zone and also a storage electrode and a control electrode, and a selection transistor having a source and a drain zone and also a control electrode, the drain zones of the storage and selection transistors being electrically conductively connected to one another. In this case, the drain zone of the selection transistor has a connection zone and an intermediate zone doped more weakly than the connection zone, the intermediate zone being arranged between the connection zone and a channel zone of the selection transistor and serving, during the programming operation, for taking up a programming voltage and thus for protecting a control electrode insulation layer of the selection transistor.

The present invention relates to an electrically programmable memory cell and to a method for programming and a method for reading from such a memory cell.
Memory cells of this type, which are also referred to as EEPROM memory cells (EEPROM=Electrically Erasable Programmable Read Only Memory), are sufficiently known.
The basic function of such an EEPROM memory cell is described for example in "Everything a System Engineer Needs to Know About Serial EEPROM Endurance", AN537, Microchip Technology Inc., 1992, pages 8–15 and 8–16.
FIG. 1 illustrates the fundamental construction of such a memory cell, with a memory transistor Ts′ and a selection transistor Ta′, at the semiconductor level (FIG. 1a) and in the equivalent circuit diagram (FIG. 1b). The basic principle of such a memory cell is based on the alteration of the threshold voltage of the memory transistor Ts′ by electrical charge being stored on a storage electrode 41′ of the memory transistor, said storage electrode being arranged in floating fashion. Depending on the memory state/programming state, when a read voltage is applied to a control electrode 44′, a conducting channel forms in a channel zone of the memory transistor between a drain zone 30′ and a source zone 20′. Said memory state can be read out by applying a voltage between the drain zone 30′ and the source zone 20′ and detecting the presence of a current flow between these connections.
In order to be able to read out the memory state of just one specific memory cell in a memory matrix having a multiplicity of identical memory cells, each memory cell has a selection transistor Ta′. The drain-source path of each memory cell is connected in series with the drain-source path of the memory transistor Ts′, and the gate electrode Ga′ of which is usually connected to a word line of the memory matrix, as will be explained below. At the semiconductor level, the drain zone of the memory transistor and the source zone of the selection transistor are usually formed jointly by the semiconductor zone 30′, which is arranged at a distance from the source zone 20′ of the memory transistor Ts′ and at a distance from the drain zone 60′ of the selection transistor Ta′. These drain and source zones 20′, 30′, 60′ are arranged jointly in a complementarily doped semiconductor layer 10′, which forms the body zone of the memory transistor Ts′ and of the selection transistor Ta′.
The programming of the memory transistor Ts′ is based on the tunnel effect. For this purpose, the insulation layer between the storage electrode 41′ and the semiconductor layer is formed in sections as tunnel insulation layer 45′, which, upon application of a sufficiently large voltage, enables a "tunneling" of charge carriers from the semiconductor body to the storage electrode 41′. In the case of the component in accordance with FIG. 1, said tunnel insulation layer 45′ is formed between the drain zone 30′ and that section of the storage electrode 41′, which lies above said drain zone 30′. This memory cell is programmed by application of a positive programming voltage between the drain zone 30′ and the control electrode Gs′ of the memory transistor. Customary programming voltages are in the region of 20 V. When such a programming voltage is applied, electrons tunnel from the drain zone 30′ to the storage electrode 41′. The storage electrode 41′ is thereby charged negatively, as a result of which the threshold voltage of the memory transistor shifts toward higher values. In order to "erase" the memory cell, the programming voltage with an opposite sign is applied between drain 30′ and control gate Gs′ in order to discharge the storage electrode 41′. In order to read from the memory cell, a read voltage is applied between the control gate Gs′ and the source connection Ss′, said read voltage being chosen such that the memory transistor turns off in the programmed state when the read voltage is present and turns on in the erased state when the read voltage is present.
In the case of the memory cell explained, the selection transistor Ta′ is required in order to apply the programming voltage required for programming the memory cell to the drain zone 30′ of the memory transistor Ts′ during the programming operation. Said programming voltage cannot be applied directly between drain 30′ and gate Gs′ of the memory transistor Ts′, but rather is applied between the drain connection 60′, Da′ of the selection transistor Ta′ and the gate Gs′, 44′ of the memory transistor Ts′, the selection transistor Ta′ being turned on by application of a drive voltage corresponding approximately to the programming voltage. Driving of the selection transistor Ta′ with a drive voltage of the order of magnitude of the programming voltage ensures that the selection transistor Ta′ is turned on throughout the programming operation.
The construction of a memory matrix has a plurality of such memory cells is explained below with reference to FIG. 2. FIG. 2 illustrates a memory matrix having only four memory cells Z11′, Z12′, Z21′, Z22′, of which two are in each case connected to a common word line WL1′, WL2′ and two are in each case connected to a common bit line pair BL1A′, BL1B′ and BL2A′, BL2B′. The memory cells have in each case a memory transistor T11s′, T112s′, T21s′, T22s′ and in each case a selection transistor T11a′, T12a′, T21a′, T22a′. The gate connections of the selection transistors T11a′–T22a′ of a row of the memory matrix are in each case connected to a common word line WL1′, WL2′, the drain connections of the selection transistors T11a′–T22a′ of a column of the memory matrix are in each case connected to a first bit line BL1A′, BL2A′ of the bit line pair and the source connections of the memory transistors T11s′–T22s′ of a column of the memory matrix are in each case connected to a second bit line BL1B′, BL2B′ of the bit line pair. Moreover, the control electrodes of the memory transistors T11s′–T22s′ of a row of the memory matrix are in each case connected to a programming and read line PL1′, PL2′.
The programming and read-out operation for a cell of this memory matrix is explained below on the basis of the memory cell Z11′, the selection transistor of which is connected to the word line WL1′ and the memory transistor T11s′ of which and which are assigned the bit line pair BL1A′, BL1B′. The drain connection of the selection transistor T11a′ of this cell Z11′ is connected to the first bit line BL1A′ and the source connection of the memory transistor T11s′ is connected to the second bit line BL1B′. For programming the memory cell, a programming voltage is applied between the programming and read line PL1′ and the first bit line BL1A′. The word line WL1′ is likewise connected to the programming voltage. In order to prevent programming of the memory cell Z12′ connected to the same programming and read line PL1′, the first bit line BL2A′ of this column of the memory matrix is biased such that approximately half of the programming voltage present at the memory transistor T11s′ of the first memory cell Z11′ is then present at the memory transistor T12s′ of said cell. The further word line of the memory matrix WL2′ is connected to a potential at which the selection transistors connected to this word line turn off, in order to prevent programming of the memory cell Z21′ connected to the same bit line as the first memory cell Z11′.
In order to read out the memory state of a specific memory cell, for example the memory cell Z11′, suitable read potentials are applied to the word line WL1′ and the programming and read line PL1′ of said cell. Moreover, a voltage is applied between the first bit line BL1A′ and the second bit line BL1B′ by connecting the first bit line BL1A′ to a positive potential, for example, and the second bit line BL1B′, via a further read transistor T1′, to reference potential GND, for example. Not specifically illustrated in FIG. 2 is a detector circuit that identifies changes in the potential of the first bit line BL1A′. Such a change occurs depending on the memory state of the memory transistor T11s′, that is to say depending on whether the memory transistor T11s′ turns on or turns off when the read voltage is applied.
In the case of the memory cell explained previously, a control voltage corresponding to the programming voltage of the memory transistor is applied to the selection transistor Ta′ during the programming operation. The gate insulation layer 70′ of said selection transistor Ta′ must be suitably dimensioned for this in order to withstand this voltage which is very high in comparison with the customary drive voltage of the selection transistor. The dielectric strength of this selection transistor lies above the dielectric strength of the gate insulation layers of components which are fabricated for example in a BCD technology (BCD technology=bipolar-CMOS-DMOS technology). Although the fundamental structure of an EEPROM memory cell could also be realized in BCD technology, the problem exists in this case, however, that additional complicated method steps would be required in order to fabricate a high-voltage-proof gate insulation layer of the selection transistor that withstands the programming voltage.

Electrically programmable memory cell and methods for programming and reading from such a memory cell


There is disclosed a method for producing polymer articles having highly functionalized surfaces excellent in biocompatibility, by irradiating the surfaces of a polymer article with an ultraviolet laser beam in a solution containing a biopolymer. According to this method, a polymer article that has surfaces with biocompatibility, can be produced.

The processing of the surfaces of organic materials represented by polymer materials, for example, using an excimer laser that oscillates high-intensity pulsed light in the ultraviolet region, is under active study as precision surface processing and precision surface machining of organic materials, from both basic and application points of view.
On the other hand, to improve the biocompatibility of the surfaces of polymer articles used for artificial internal organs, sensors, etc., in the medical field is an important subject for improvement of the lifetime and reliability of implant-type artificial internal organs and implant-type sensors. Various investigations have been made so far, but under present conditions, practically endurable effective processing techniques have not yet been found. This is because various properties needed for artificial internal organs and sensors, such as mechanical strength (toughness) and durability, tend to be incompatible with biocompatibility. That is, polymer materials excellent in biocompatibility (e.g. biopolymers) are often low in mechanical toughness and cannot be used as articles. On the other hand, polymer materials excellent as articles are inferior in biocompatibility and therefore cannot be implanted as medical materials in the body for a long period of time.
Accordingly, under present conditions, materials having both properties to a certain extent are currently used, tentatively. Under these conditions, a conceivable method for improving biocompatibility of the surfaces of polymer articles is to chemically coat the surfaces of an article excellent in mechanical toughness with a substance excellent in biocompatibility. Since biocompatibility depends on surface properties, by coating the surface thinly with a substance excellent in biocompatibility through chemical bonds between the surface and the substance, the biocompatibility of an article can be improved without detriment to the other properties of the article.
Kaetsu reported a method for immobilizing polysaccharides on the surfaces of a polymer article by irradiating the polymer article with light from an ultraviolet lamp in an aqueous solution of a mixture of polysaccharides and a photopolymerization initiator, to initiate a crosslinking reaction by the initiator (Nucl. Instr. and Meth. in Phys. Res., Vol. B105, p 294 (1995)). This method is successful in immobilizing polysaccharides that are one type of biopolymers excellent in biocompatibility on the surfaces of an article, to improve the biocompatibility of the surfaces of the article. However, since, in this method, the crosslinking reaction by the photopolymerization initiator takes place randomly in solution, the thickness of the film of the polysaccharides immobilized on the article surfaces becomes increased, leading to the disadvantages that the mechanical properties of the article are lowered, and that the photopolymerization initiator inevitably remains in the modification layer as impurities.
The present inventors proposed methods for effectively modifying the surfaces of a polymer article by ultraviolet laser processing (JP-A-4-183873 ("JP-A" means unexamined published Japanese patent application), JP-B-7-5775 ("JP-B" means examined Japanese patent publication), and JP-B-7-5777). With these methods, it is found out that, for instance, since active species are produced on the surfaces of an article by irradiation with a laser, an organic compound having a functional group, such as an azide group, a vinyl group, and an acetylene group, can be introduced on the surfaces of the article, to react with the active species on the surface, so that the organic compound can be immobilized through chemical bonds on the article surfaces irradiated with the laser beam. According to these methods, an organic compound, different from those constituting the article can be immobilized onto the surface of the article, without using photopolymerization initiators that will become an impurity.

Method for producing polymer articles with a modified surface

Director-General of Agency of Industrial Science and Technology


A processor associated with a vehicle receives sensor data from a plurality of sensors in the vehicle. Each sensor is configured to measure a different parameter of a driver of the vehicle. The processor applies a model to the received sensor data, which when applied causes the processor to output a determination, based on the parameters of the driver, of attentiveness of the driver to driving the vehicle. Responsive to the determination indicating the driver is not attentive to driving the vehicle, the processor causes the vehicle to output an alert to the driver or to automatically control a driving function of the vehicle.

One key challenge facing the proliferation of self-driving vehicles (e.g., the transition from level 2 to level 5 cars) is the requirement that drivers continually pay attention to the road, traffic, and their surroundings even when the vehicle is in autonomous mode. Drivers can easily spoof current systems for verifying and monitoring passenger physical attention as they today rely predominantly on pressure and other sensors in the steering wheel. For example, drivers can simply place a water bottle or other object on the steering wheel to indicate to the attention-monitoring system that they are "paying attention." This lack of attention can lead to safety hazards ranging from trivial to catastrophic and potentially fatal.
Accordingly, there is a need for improved systems and methods for verifying and monitoring car passenger physical attention that are not easily spoofed.

Systems and methods for verifying and monitoring driver physical attention


A circuit and a method for generating a random number are provided. The circuit for generating the random number includes an analog-to-digital converter and a controller. The analog-to-digital converter sequentially generates a plurality of digital data in response to an analog signal. The controller utilizes an estimation procedure to sequentially analyze a variation trend of the plurality of digital data in a time sequence or extract components of the plurality of digital data within a preset frequency band. In addition, the controller generates a true random number based on a result of the estimation procedure.

1. Field of the Invention
The present invention relates to a circuit and a method for generating a random number, and more particularly, to a circuit and a method for generating a random number based on an output of an analog-to-digital converter.
2. Description of Related Art
With vigorous development of computer information and cloud technology, increasingly importance has been attached to data security. In particular, security and confidentiality of data transmission have attracted special attention. Data confidentiality during transmission is closely related to encryption and decryption theory that is used. In general, data encryption and decryption usually uses a key as an operator for data scrambling or an operator for data recovery. Besides, the key used in a system must be generated through an irregular random number.
Accordingly, common electronic devices with the encryption and decryption function must have a random number generator for generating a random number which is used to generate the key for encryption and decryption. However, the disposition of the random number generator necessarily increases the hardware space and manufacturing cost of the electronic device. Therefore, simplifying the circuit architecture of the random number generator to reduce the manufacturing cost and hardware space of the electronic device has become an important subject in designing the random number generator.

Circuit and method for generating random number


A method and apparatus are provided for sending a data packet through a network. The network has public and private realms separated by an interface device. A client in the private realm performs the method. The method includes determining if a destination address of the data packet corresponds to the private realm or to the public realm and retrieving a source address for the client based on the destination address of the packet. The method also includes assigning a retrieved address to be the source address of the data packet.

A computer network may include a private realm and a public realm. The private realm contains computers sharing a private addressing scheme known only to the computers in that private realm. The public realm contains computers sharing a public addressing scheme known to all computers in the network, whether public or private. A packet may be sent between computers on the public and private realms through an interface device, such as a gateway.
Like reference symbols in the various drawings indicate like elements.

Assigning a source address to a data packet based on the destination of the data packet