A network node (44) assists a user equipment (36) to perform positioning measurements on positioning signals (46) transmitted by one or more cells during respective positioning occasions of those cells. The node (44) selectively delays transmission of assistance data to the user equipment (36) as needed, based on defined uncertainty in one or more timing parameters, for the network node (44) to identify with certainty between which two consecutive positioning occasions of a reference cell the user equipment (36) will receive that assistance data. The node (44) correspondingly generates the assistance data to be transmitted to indicate positioning occasion timing for at least one cell relative to the latter of those two consecutive positioning occasions of the reference cell. Such calculation and transmission enables the user equipment (36) to be certain that the next reference cell positioning occasion occurring after its reception of the assistance data is the reference cell positioning occasion on which the assistance data is based.

The availability of several techniques and devices for identifying the geographical location of mobile device users has enabled a large variety of commercial and non-commercial services, such as navigation assistance, enhanced social networking, location-aware advertising, and location-aware emergency calls. However, different services may have different positioning accuracy requirements imposed by the application. In addition, some regulatory requirements on the positioning accuracy for basic emergency services exist in some countries, such as the FCC's E-911-related requirements in the United States.
In many environments, the position of a mobile device user can be accurately estimated by using positioning methods based on GPS (Global Positioning System) or other satellite-based system. Nowadays, wireless networks are often able to provide positioning-related assistance to mobile terminals (often referred to as user equipment, or UEs, or wireless terminals, mobile stations, or simply "mobiles") to improve the terminal's receiver sensitivity and GPS start-up performance. Several of these techniques are known as Assisted-GPS positioning, or A-GPS.
GPS or A-GPS receivers may not be available in all UE, however. Furthermore, GPS is known to fail in certain indoor environments and in urban "canyons" in the radio shadows caused by tall buildings. Complementary terrestrial positioning methods, such as one approach called Observed Time-Difference-of-Arrival (OTDOA), have therefore been standardized by the 3rd-Generation Partnership Project (3GPP) and are deployed in various wireless networks. In addition to OTDOA, the 3GPP standards for the so-called Long-Term Evolution (LTE) wireless system also specify methods, procedures and signalling support for techniques called Enhanced Cell ID (E-CID) and Assisted Global Navigation Satellite System (A-GNSS). Later, a network-based technique called Uplink Time-Difference-of-Arrival (UTDOA) may also be standardized for LTE.
Three key network elements for providing location services (LCS) in an LTE positioning architecture include the LCS Client, the LCS target and the LCS Server. The LCS Server is a physical or logical entity managing positioning for a LCS target device by collecting measurements and other location information, assisting the terminal in measurements when necessary, and estimating the LCS target location. A LCS Client is a software and/or hardware entity that interacts with a LCS Server for the purpose of obtaining location information for one or more LCS targets, i.e. the entities being positioned. LCS Clients may reside in the LCS targets themselves. An LCS Client sends a request to LCS Server to obtain location information, and LCS Server processes and serves the received requests and sends the positioning result and optionally a velocity estimate to the LCS Client.
Position calculation can be conducted, for example, by a UE or by a positioning server, such as an Enhanced Serving Mobile Location Center, E-SMLC, or Secure User Plan Location (SUPL) Location Platform (SLP) in LTE. The former approach corresponds to the UE-based positioning mode, whilst the latter corresponds to the UE-assisted positioning mode.
Two positioning protocols operating via the radio network exist in LTE, LTE Positioning Protocol (LPP) and LPP Annex (LPPa). The LPP is a point-to-point protocol between a LCS Server and a LCS target device, used in order to position the target device. LPP can be used both in the user and control plane, and multiple LPP procedures are allowed in series and/or in parallel thereby reducing latency. LPPa is a protocol between evolved Node B (eNodeB) and LCS Server specified only for control-plane positioning procedures, although it still can assist user-plane positioning by querying eNodeBs for information and eNodeB measurements. SUPL protocol is used as a transport for LPP in the user plane, LPP has also a possibility to convey LPP extension messages inside LPP messages, e.g. currently Open Mobiel Alliance (OMA) LPP extensions are being specified (LPPe) to allow e.g. for operator-specific assistance data or assistance data that cannot be provided with LPP or to support other position reporting formats or new positioning methods.
A high-level architecture of such an LTE system 10 is illustrated in FIG. 1. In FIG. 1, the system 10 includes a UE 12, a radio access network (RAN) 14, and a core network 16. The UE 12 comprises the LCS target. The core network 16 includes an E-SMLC 18 and/or an SLP 20, either of which may comprise the LCS Server. The control plane positioning protocols with the E-SMLC 14 as the terminating point include LPP, LPPa, and LCS-AP. The user plane positioning protocols with the SLP 16 as the terminating point include SUPL/LPP and SUPL. Although note shown, the SLP 20 may comprise two components, a SUPL Positioning Center (SPC) and a SUPL Location Center (SLC), which may also reside in different nodes. In an example implementation, the SPC has a proprietary interface with E-SMLC, and an Llp interface with the SLC. The SLC part of the SLP communicates with a P-GW (PDN-Gateway) 22 and an External LCS Client 24.
Additional positioning architecture elements may also be deployed to further enhance performance of specific positioning methods. For example, deploying radio beacons 26 is a cost-efficient solution which may significantly improve positioning performance indoors and also outdoors by allowing more accurate positioning, for example, with proximity location techniques.
To meet varying demands for different Location-Based Services (LBS), an LTE network will deploy a range of complementing methods characterized by different performance in different environments. Depending on where the measurements are conducted and where the final position is calculated, the methods can be UE-based, UE-assisted, or network-based, each with own advantages. The following methods are available in the LTE standard for both the control plane and the user plane: (1) Cell ID (CID), (2) UE-assisted and network-based E-CID, including network-based angle of arrival (AoA), (3) UE-based and UE-assisted A-GNSS (including A-GPS), and (4) UE-assisted OTDOA.
Several other techniques such as hybrid positioning, fingerprinting positioning and adaptive E-CID (AECID) do not require additional standardization and are therefore also possible with LTE. Furthermore, there may also be UE-based versions of the methods above, e.g. UE-based GNSS (e.g. GPS) or UE-based OTDOA, etc. There may also be some alternative positioning methods such as proximity based location. UTDOA may also be standardized in a later LTE release, since it is currently under discussion in 3GPP. Similar methods, which may have different names, also exist for radio-access technologies (RATs) other than LTE, such as CDMA, WCDMA or GSM.
With particular regard to the OTDOA positioning method, this method makes use of the measured timing of downlink signals received from multiple base stations (evolved NodeBs, or eNodeBs, in LTE) at the UE. The UE measures the timing of the received signals using assistance data received from the LCS server, and the resulting measurements are used to locate the UE in relation to the neighbouring eNodeBs.
More specifically, the UE measures the timing differences for downlink reference signals received from multiple distinct locations or neighboring cells. For each (measured) neighbor cell, the UE measures Reference Signal Time Difference (RSTD), which is a relative timing difference between the neighbor cell and a defined reference cell. The UE position estimate is then found as the intersection of hyperbolas corresponding to the measured RSTDs. At least three measurements from geographically dispersed base stations with a good geometry are needed to solve for two coordinates of the UE and the receiver clock bias. In order to solve for position, precise knowledge of the transmitter locations and transmit timing offset is needed.
To enable positioning in LTE and facilitate positioning measurements of a proper quality and for a sufficient number of distinct locations, new physical signals dedicated for positioning (positioning reference signals, or PRS) have been introduced and low-interference positioning subframes have been specified in 3GPP. Details are specified in 3GPP TS 36.211; as of February 2011, version 10.0.0 of this specification is available from http://www.3gpp.org.
PRS are transmitted from one antenna port of a base station according to a pre-defined pattern. A frequency shift, which is a function of Physical Cell Identity (PCI), can be applied to the specified PRS patterns to generate orthogonal patterns. The mapping of frequency shifts to PCT models an effective frequency reuse of six, which makes it possible to significantly reduce neighbor cell interference on the measured PRS and thus improve positioning measurements. Even though PRS have been specifically designed for positioning measurements and in general are characterized by better signal quality than other reference signals, the standard does not mandate using PRS. Other reference signals, e.g. cell-specific reference signals (CRS) could be used for positioning measurements, in principle.]
PRS are transmitted in pre-defined positioning sub-frames grouped by several consecutive sub-frames (NPRS), i.e., one positioning occasion. FIG. 2, for instance, shows an example where one positioning occasion includes PRS transmitted in NPRS=6 consecutive sub-frames. Positioning occasions occur periodically with a defined periodicity TPRS of N sub-frames, i.e., the time interval between two positioning occasions. The standardized periods TPRS are 160, 320, 640, and 1280 ms, and the standardized number of consecutive sub-frames NPRS may be 1, 2, 4, or 6
Information about such PRS and other information that will assist with positioning measurements is included in so-called assistance data. Different sets of assistance data are typically used for different methods. Regardless, the positioning assistance data is sent by the positioning server, or via some other node, to UEs or other radio nodes in order to assist with positioning measurements. For example, assistance data may be sent via LPP to an eNodeB for transmission to the UE. In this case, the transmission of assistance data may be transparent to the eNodeB and the Mobility Management Entity (MME). The assistance data may also be sent by the eNodeB via LPPa to a positioning server for further transfer to the UE. In some cases, the assistance data may be sent on request from a wireless device that needs to perform measurements. In other cases, the assistance data is sent in an unsolicited way.
In LTE, the assistance data may be requested and provided over LPP protocol by including requestAssistanceData and provideAssistanceData elements in the LPP message, respectively. The current LTE standard specifies the following structure for provideAssistanceData, which is illustrated in FIG. 3, where the commonIEsProvideAssistanceData information element (IE) is provided for future extensibility only and is not used so far. The LTE assistance data may thus be provided for A-GNSS and OTDOA. The EPDU-Sequence contains IEs that are defined externally to LPP by other organizations, which currently may only be used for OMA LPP extensions (LPPe).
Since for OTDOA positioning PRS signals from multiple distinct locations need to be measured, the UE receiver may have to deal with PRS that are much weaker than those received from the serving cell. Furthermore, without an approximate knowledge of when the measured signals are expected to arrive in time and what is the exact PRS pattern, the UE must perform signal search within a large window. This can impact the time and accuracy of the measurements as well as the UE complexity. To facilitate UE measurements, the network transmits assistance data to the UE, which includes, among other things, reference cell information, a neighbour cell list containing Physical Cell Identifiers (PCIs) of neighbour cells, the number of consecutive downlink subframes within a positioning occassion, PRS transmission bandwidth, frequency, etc.
In LPP, the OTDOA assistance data is provided within the Information Element (IE) OTDOA-ProvideAssistanceData, as shown in FIG. 4. Similar structures for OTDOA exist in LPPe.
The OTDOA assistance data includes information about the reference cell and neighbour cells for which OTDOA is to be determined. The neighbour cells may or may not be on the same frequency as the reference cell, and the reference cell may or may not be on the same frequency as the serving cell, and may or may not be the serving cell. Measurements that involve cells on a frequency different than the serving cell are inter-frequency measurements. Measurements on the same frequency as the serving cell are intra-frequency measurements. Different requirements apply for intra- and inter-frequency measurements.
For each cell in the assistance data, PRS information may be provided. The following information comprises the PRS information, according to 3GPP TS 36.355: PRS, bandwidth, PRS configuration index, the number NPRS of consecutive DL subfrarnes (1, 2, 4, or 6) where PRS are transmitted, and muting information, PRS configuration index for a cell, as specified in 3GPP TS 36.211, defines the offset of that cell's first PRS subframe from a reference time point (SFN=0, where SFN refers to System Frame Number), as well as the periodicity TPRS of that cell's positioning occasions.
PRS information, in particular PRS periodicity, may be cell-specific. The cell-specific nature of the PRS information may be attributable to different cells belonging to different systems, different cells having different PRS bandwidths (e.g., a smaller bandwidth may require more frequent PRS occasions), different cells having different traffic loads (e.g., to reduce PRS overhead and capacity loss when no data transmissions are allowed in PRS positioning occasions, less frequent PRS positioning occasions may be configured), or the like.
Furthermore, positioning occasions may be misaligned on purpose, e.g., due to network deployment issues. Such purposeful misalignment might exist, for instance, in a network with a mix of macro cells and low-power nodes (e.g., pica or femto nodes), since interference issues may be caused by that network deployment. In a synchronous, or at least subframe-aligned network, an alternative could be to configure more frequent PRS positioning occasions that are aligned for cells, but to configure muting to avoid PRS collisions with interfering neighbour cells. See, e.g., International Patent Application PCT/SE2010/050947.
Positioning occasion misalignment may also be attributable to inter-frequency RSTD measurements. More particularly, some UEs require measurement gaps in order to perform inter-frequency RTSD measurements. The measurement gaps are configured by an eNodeB upon an indication from a LIE. Measurement gaps need to be aligned with PRS positioning occasions of the measured cell. However, according to the standard, the measurement gaps cannot collide with PRS positioning occasions of the cells belonging to the serving carrier. Given that the PRS periodicity is a multiple of the measurement gap periodicity (40 ms, when inter-frequency RSTD measurements are configured), this means that PRS positioning occasions of a neighbour cell cannot collide with PRS positioning occasion of the reference cell. So, in networks supporting inter-frequency RSTD measurements, particularly with UEs using measurement gaps for inter-frequency measurements, PRS positioning occasions shall be misaligned between cells on the serving carrier and another carrier. This implicitly means that PRS positioning occasions shall be misaligned among all carriers that may appear in the same assistance data message for a UE, since different UEs may be served by different cells. Nonetheless, PRS positioning occasions will typically be fully or partially aligned in cells operating on the same frequency. However, there is no reason to require PRS positioning occasion to be the same on all frequencies.
In view of these different timing possibilities for PRS, assistance data provided to a UE assists the UE to determine at least the relationship between the timing of different PRS (e.g., relative to the timing of PRS for the reference cell). For example, the following parameters specified in 3GPP TS 36.355 may be used for determining the timing relation between PRS signals received in the first subframes of the positioning occasions of two cells: (a) slotNumberOffset; (b) prs-SubframeOffset; (c) expectedRSTD; (d) expectedRSTD-Uncertainty; (e) prs-Configurationindex. Then, based on muting information (prs-MutingInfo), the UE also can determine in which positioning occasions the LIE is supposed to measure.
Nonetheless, known approaches for employing assistance data remain insufficient for supporting cell-specific PRS configurations. Indeed, practical scenarios may arise where known approaches cause a UE to incorrectly determine the timing relation between a positioning occasion of one cell and a positioning occasion in another cell. Indeed, in such a scenario, one timing relation appears correct to the node generating the assistance data, and a different timing relation appears correct to the UE receiving the assistance data. This ambiguity in which timing relation is correct leads to the UE's incorrect determination.
Although the above problems have primarily been discussed in the context of certain wireless systems and certain positioning methods, these problems extend to other systems and other methods as well. Indeed, with Open Mobile Alliance (OMA) LPP extension (LPPe), the assistance data is enhanced with the possibility to assist a larger range of positioning methods. For example, the assistance data may also be provided for E-CID or other methods of other radio access technologies (RATs), e.g. OTDOA UTRA or E-OTD GSM, or other PLMN networks.

Network-side removal of positioning assistance ambiguity via selective delay of assistance data transmission


There is provided a process for producing beads for enantiomeric isomer resolution with a satisfactory separation efficiency. The beads for enantiomeric isomer resolution include a polysaccharide derivative, in which the polysaccharide derivative has a structure crosslinked at the 6-position hydroxy group of constituent units of the polysaccharide with a crosslinking agent. The process for producing the beads for enantiomeric isomer resolution includes: the step of adding dropwise an organic solvent solution of the polysaccharide derivative to a coagulation bath being stirred to thereby produce beads; the step of taking out the beads and then optionally drying the same after washing; and the step of reacting the beads with a crosslinking agent in an organic solvent to react at least part of the 6-position hydroxy groups in the constituent units of the polysaccharide with the crosslinking agent, thereby obtaining a reaction mixture containing beads having a crosslinked structure.

In recent years, the importance of an optically active compound has increased even more, and a process for selectively and efficiently producing a pure optically active chiral molecule from the viewpoint of research and development not only of pharmaceuticals but also of functional materials is indispensable.
The optical resolution by HPLC is developed as a process which can be used for both fractionation and microanalysis, and there has been progress in the development of various chiral fillers. Of those, a substance obtained by converting a polysaccharide which abundantly exists in nature, such as cellulose and amylose, to a phenylcarbamate derivative is widely used because such a substance has an excellent optical resolution ability to various kinds of racemates including pharmaceuticals, as a chiral stationary phase for HPLC.
In the chiral stationary phase using those polysaccharide derivatives, used as a filler is a derivative which is physically adsorbed on or chemically bonded to silica gel serving as a carrier. However, such a filler that is supported on silica gel in the above-mentioned manner cannot use, as an eluent, a solvent in which a polysaccharide derivative is swollen and/or dissolved. Further, the proportion of the polysaccharide derivative contained in the filler is small, and substantially, only the polysaccharide derivative on the surface of silica gel is used for optical resolution. Thus, in such a filler, there is room for improvement as a filler for fractionation.
JP-B-7-63622 discloses a separating agent formed of particles of 7 to 13 μm obtained by crushing and classifying polysaccharide derivatives in which 10% or more of hydroxyl groups were substituted with a carbamoyl group. Further, JP-B-7-63622 discloses, on page 2, column 4 that crosslinking may be performed as required, but there is no specific description.

Bead for enantiomeric isomer resolution and process for producing the same

National University Corporation, Nagoya University


Various implementations described herein refer to an integrated circuit having an array of bitcells coupled between at least one pair of bitlines including a first bitline and a second bitline that is a complement of the first bitline. The integrated circuit may include at least one pair of ancillary lines disposed adjacent to the at least one pair of bitlines, and the at least one pair of ancillary lines include a first ancillary line disposed adjacent to the first bitline and a second ancillary line disposed adjacent to the second bitline. The integrated circuit may include multiple pairs of passgates coupled between the at least one pair of bitlines and the at least one pair of ancillary lines.

This section is intended to provide information relevant to understanding the various technologies described herein. As the section's title implies, this is a discussion of related art that should in no way imply that it is prior art. Generally, related art may or may not be considered prior art. It should therefore be understood that any statement in this section should be read in this light, and not as any admission of prior art.
In modern memory design, poor resistance scaling has increasingly become a problem as the integrated circuit (IC) industry scales down feature density. One traditional method of improving resistance refers to adding additional higher metal line straps. While this can be effective in reducing resistance, it may increase capacitance. Therefore, this becomes a difficult problem for memory designers as resistance and capacitance do not scale down together. There can be a trade-off of lower resistance with higher capacitance or vice versa. High resistance impacts memory write margins and write performance, and high capacitance impacts memory read performance and read dynamic power.


The present invention is an alternative Fourier domain optical coherence system (FD-OCT) and its associated method. The system comprises a swept multi-wavelength laser, an optical interferometer and a multi-channel receiver. By employing a multi-wavelength laser, the sweeping range for each lasing wavelength is substantially reduced as compared to a pure swept single wavelength laser that needs to cover the same overall spectral range. The overall spectral interferogram is divided over the individual channels of the multi-channel receiver and can be re-constructed through processing of the data from each channel detector. In addition to a substantial increase in the speed of each axial scan, the cost of invented FD-OCT system can also be substantially less than that of a pure swept source OCT or a pure spectral domain OCT system.

1. Field of the Invention
The invention relates generally to optical coherence tomography (OCT) and in particular to Fourier domain optical coherence tomography.
2. Description of Related Art
Optical Coherence Tomography (OCT) is a technology for performing high-resolution cross sectional imaging that can provide images of tissue structure on the micron scale in situ and in real time. In recent years, it has been demonstrated that Fourier domain OCT (FD-OCT), which so far employs either a wavelength swept source and a single detector or a broadband source and an array spectrometer, has significant advantages in both speed and signal-to-noise ratio as compared to time domain OCT (TD-OCT). In TD-OCT, the optical path length between the sample and reference arms needs to be mechanically scanned. For example, patent application WO03062802 (EP1470410, CA2474331, US20050018201) is a hybrid time and spectral domain OCT system in which a broadband source is combined with sub-depth range mechanical optical path length scanning and parallel detection of a set of optical spectral bands. This design can increase the signal-to-noise ratio and at the same time reduce the mechanical scanning range. But mechanical scanning is still required and the A-scan speed is thus limited.
In both swept source OCT (SS-OCT) and spectrometer-based spectral domain OCT (SD-OCT), the optical path length difference between the sample and reference arm is not mechanically scanned, instead, a full axial scan (also called A-scan) is obtained in parallel for all points along the sample axial line within a short time determined by the wavelength sweep rate of the swept source (in SS-OCT) or the line scan rate of the line scan camera (in SD-OCT). As a result, the speed for each axial scan can be substantially increased as compared to the mechanical scanning speed of TD-OCT and this is especially beneficial for real-time imaging of movable biological samples such as the human eye. In addition, SD-OCT and SS-OCT can provide substantially greater signal-to-noise ratio relative to TD-OCT, as explained by Mitsui and others ("Dynamic Range of Optical Reflectometry with Spectral Interferometry." Japanese Journal of Applied Physics 38(10): 6133-6137). There are a number of patents as well as articles that either disclosed the basic concept of or discussed the advantages of Fourier domain OCT using either a swept single wavelength source combined with a single photodetector or a broadband source combined with an array spectrometer. Several of these articles and patents are listed separately under the REFERENCES section. These and other articles and patents cited are all incorporated herein as references of this invention.
However, these prior arts are based on purely employing either a swept single wavelength source combined with a single photodetector (thereafter called pure swept-source OCT or pure SS-OCT) or a broadband source combined with an array spectrometer, comprising an optical spectral dispersing element and an array of photodetectors (thereafter called pure spectral-domain OCT or pure SD-OCT). A pure SS-OCT or a pure SD-OCT system each has its advantages and disadvantages in terms of cost, speed, size, stability and other factors as will be elaborated shortly. Based on the advantages of FD-OCT and most importantly, the cost of currently available optical components, we describe an alternative FD-OCT system that not only retains the advantageous features of a pure SS-OCT and a pure SD-OCT, but also saves the cost of the overall system and increases the speed.
In order to fully appreciate the novel features of the present invention, let us first take a brief look at a pure SS-OCT system and a pure SD-OCT system. FIG. 1 shows the basic configuration of a pure SS-OCT system. Light from a tunable single wavelength laser 102 is split through a beam splitter or fiber coupler 104 into a reference arm 106 and a sample arm 108 of an interferometer and the interference signal is detected with a single high-speed photodetector 110. By sweeping the wavelength of the monochromatic source 102, the spectral interferogram of the OCT interferometer is recorded sequentially. The axial reflectance distribution of the sample is obtained by a Fourier transform of the sequentially acquired detector signal. The most advantageous feature of a pure SS-OCT system, compared to other FD-OCT systems, is its compactness and simplicity. For example, patent application US20050035295 and the article by Oh, W. Y. et al. ("Wide tuning range wavelength-swept laser with two semiconductor optical amplifiers." Photonics Technology Letters, IEEE 17(3): 678-680) disclosed a wavelength tuning source for SS-OCT that employs a continuously rotating optical arrangement for lasing wavelength selection. In this prior art, a single rotating polygon can be combined with two (or more) gratings and two (or more) optical amplifiers of different optical gain bandwidth to generate a combined wide band wavelength scanning light. The combined output can be synchronized because of the use of a single rotating polygon to provide a continuous linear wavelength tuning over a wide spectral range. However, the current price of a swept source that meets the specification requirement of a practical pure SS-OCT system is very high (see for example, Thorlab Inc. Product Catalog, Vol. 17, (2005) page 469) and in addition, the demonstrated wavelength sweep rate is limited to about 20 kHz (Oh, W. Y. et al. (2005). "Wide tuning range wavelength-swept laser with two semiconductor optical amplifiers." Photonics Technology Letters, IEEE 17(3): 678-680). Furthermore, commercial products currently having a high price tag are still in the stage of further development, whereas tunable semiconductor lasers developed for optical fiber communications either are step-tuned to fit the ITU grid (see for example, Amano, T. et al. (2005). "Optical frequency-domain reflectometry with a rapid wavelength-scanning superstructure-grating distributed Bragg reflector laser." Applied Optics 44(5): 808-816) or, if continuously tunable, are very slow (see for example, U.S. Pat. No. 6,847,661) and they do not meet the requirement for a pure SS-OCT system, such as the high wavelength sweeping rate (more than 20 kHz) and the broad spectral range to be covered (e.g. 25 to 200 nm).
FIG. 2 shows the basic configuration of a pure SD-OCT system. Its difference from a pure SS-OCT system is that instead of a wavelength swept laser and a single detector, a broadband source 202 is used and a grating 212 disperses the interfered optical wave to a photodetector array 214. The main disadvantage of a pure SD-OCT system is the bulky size of the spectrometer 216 and the output sensitivity of the spectrometer 216 to mechanical vibration and temperature change. One advantage is the relatively lower cost of the superluminescent diode (˜$1 k) that can be used as the source 202 and a Si (silicon) based line scan camera ($2 k˜$4 k) that can be used as the detector array 214. However, a Si based line scan camera has a limited wavelength response range from 0.25 to 1.1 μm. While this wavelength range is appropriate for some biological imaging applications, longer wavelengths are advantageous in many other applications. For example, melanin pigment and hemoglobin are less absorptive for wavelengths between 1 and 2 μm than for visible light. For OCT in the front portions of the human eye, wavelengths longer than 1 μm offer the advantage of higher illumination power without exceeding eye-safety limits, because water in the eye largely absorbs light of these wavelengths before it reaches the sensitive human retina. As Si cannot cover this wavelength range, InP or InGaAs based detector array appears to be the only practical alternative. Unfortunately, the current price of InP or InGaAs based photodetector array is very high and the line scan rate of these detector arrays is limited to 10 kHz range.
A need therefore exists for an alternative FD-OCT design that can take the speed advantage of FD-OCT without requiring a high-speed array detector, or a high-speed wide-range swept laser source.
The sweep range and sweep speed of a continuously tunable laser are generally limited by the swept filter acting as a tuning element. In addition, laser dynamics limits the sweep speed, especially for longer-cavity lasers. (See for example, Huber, R. et al. (2005). "Amplified, frequency swept lasers for frequency domain reflectometry and OCT imaging: design and scaling principles." Optics Express 13(9): 3513-3528).
Some examples of sweepable filters that can be used in tunable sources are: 1) piezoelectrically-driven Fabry-Perot filters, 2) unbalanced fiber-based Mach-Zehnder interferometers, 3) distributed Bragg reflectors (DBR), 4) distributed feed-back (DFB) in the gain medium of the laser itself, and 5) rotating gratings outside the laser cavity. For most filter types, especially the first four, smaller sweep ranges are more easily achieved than large sweep ranges. For example, a semiconductor-based DBR, tuned by carrier density, can change the refractive index by 1%, resulting in a tuning range of 1%. The desired tuning range for pure SS-OCT of biological samples is at least 25 nm, which is 2% of a typical laser wavelength of 1310 nm. Each of these filter types can be naturally adapted to pass several wavelengths simultaneously, because they are based on interference and can operate on multiple orders of interference simultaneously.
In this invention, a continuously swept multi-wavelength laser is combined with an optical multi-channel receiver. The multi-wavelength laser emits several optical frequencies or wavelengths simultaneously. This source covers a broad frequency range in a short time by sweeping the set of individual lasing frequencies so that each lasing frequency covers a portion of the full spectrum. The individual lasing optical frequencies are swept over a relatively small range between neighboring lasing frequencies. As a result, the cost of the FD-OCT system can be markedly reduced. The proposed continuously swept multi-wavelength laser can also be made at a low cost as it is only slightly different from standard tunable semiconductor lasers for telecom applications. An additional very beneficial feature of the invention is that the time required for each A-scan can now be substantially reduced, which means that the A-scan rate can be substantially increased relative to the single lasing wavelength swept-source. The individual lasing frequencies simultaneously excite the OCT interferometer, and a multi-channel optical receiver can separate and record the resulting interference signals from the individual optical frequencies. The required multi-channel receiver is now commercially available at a relatively low cost and the price is still continuously dropping as a result of the development for optical fiber telecom applications.

Fourier domain optical coherence tomography employing a swept multi-wavelength laser and a multi-channel receiver


A device for matching the operation of a travelling unit in a construction vehicle is disclosed. The device reduces the required levering force of a travelling control pedal, easily controls the rotating force of an engine, and safely changes the engine output torque in accordance with both the levering stroke of the travelling control pedal and a travelling resistance. The device has a pressure reduction valve which is synchronized with a levering motion of a travelling control pedal in order to feed pilot fluid from a pilot pump to a direction select valve. A branch line is branched from a fluid line extending between the pressure reduction valve and the direction select valve. A hydraulic cylinder is connected to the branch line and selectively receives the pilot fluid through the branch line when the travelling control pedal is levered. A connection means is connected between a throttle lever of an engine and the hydraulic cylinder and moves the throttle lever of the engine in accordance with the displacement of the hydraulic cylinder, thereby controlling the number of revolutions of the engine.

1. Field of the Invention
The present invention relates, in general, to a device for matching the operation of a travelling unit in a construction vehicle and, more particularly, to a structural improvement in such a matching device for reducing the required levering force of a travelling control pedal, easily controlling the output power of an engine, and safely changing the engine output power and torque in accordance with both the levering stroke of the travelling control pedal and the travelling resistance, thereby effectively controlling the travelling unit during an operation of the construction vehicle.
2. Description of the Prior Art
A device, which simultaneously controls both a main hydraulic pump and an engine of a construction vehicle, such as a power excavator, by a levering stroke of a travelling control pedal, is known to those skilled in the art.
FIG. 1 shows the construction of the hydraulic system of a typical device for matching the travelling unit in a construction vehicle. As shown in FIG. 1, when both a travelling pedal 101 and a direction select valve 103 are handled by an operator during the operation of a construction vehicle, a pilot pressure output from a pilot pump 105 is applied to a directional control valve (travelling control valve) 109 associated with a travelling motor M through both a pressure reduction valve 107 and the direction select valve 103, thereby moving the spool of the travelling control valve 109 in either direction. Both the pressure reduction valve 107 and the direction select valve 103 are synchronized with a levering motion of the travelling pedal 101. When the spool of the travelling control valve 109 is moved in either direction by the pilot pressure, pressurized fluid output from a main hydraulic pump P is controllably fed to the travelling motor M through the valve 109, thus moving the construction vehicle to the front or back in accordance with a selected direction of the direction select valve 103.
In the above state, the levering force of the travelling pedal 101 is transmitted to a throttle lever 113 of an engine ENG through both a linkage 111 and a cable 115 thus increasing or reducing the number of revolutions of the engine ENG. The linkage 111 is coupled to the lower end of the travelling pedal 101, while the cable 115, extends from the linkage 111 to the throttle lever 113 of the engine ENG.
That is, the typical matching device controls both the travelling motor M and the engine ENG by a single levering motion of the travelling pedal 101.
However, the above matching device is problematic in that it has a complex construction, so that it is difficult to design and assemble. The complex construction increases the manufacturing cost and the complexity of the manufacturing process of the matching device. In addition, slack is generated in the linkage 111, so that it may fail to precisely control the engine ENG and travelling motor M.
In an effort to overcome the above problems, a device, which converts the levering stroke of the travelling pedal into a hydraulic force and moves the throttle lever of the engine using the hydraulic force, is known to those skilled in the art. Japanese U.M. Laid-open Publication No. Sho. 61-167440 (published on Oct. 17, 1986) and Korean U.M. Registration No. 95-06053 disclose examples of such a device.
In addition, Japanese U.M. Laid-open Publication No. Hei. 3-42855 discloses a device which has an improved construction and operational effect over those of the above Japanese and Korean devices. In the above-mentioned devices, a levering motion of a travelling pedal causes a secondary pressure, thereby directly controlling a travelling control valve, while a pump and engine are controlled by a signal operation means in response to the secondary pressure.
However, the above devices are problematic in that a slow return valve included in the devices is delicate to foreign substances, thereby often failing to return the travelling control valve to a neutral position. In the above state, the devices fail to stop the travelling unit due to a hydraulic resistance, thereby causing safety hazards even though the levering force is removed from the travelling pedal. In the above devices, the direction select valve must be returned to a neutral position when it is necessary to stop the travelling unit. That is, in order to stop the travelling unit, the direction select valve must be returned to the neutral position in order to return the pilot pressure of the travelling control valve to a return tank and to switch the travelling control valve into a neutral position. Therefore, the devices may cause safety hazards when the direction select valve is not controlled by an operator during the operation of a construction vehicle.

Device for matching the operation of travelling unit in construction vehicles

Volvo Construction Equipment Korea Co., Ltd.


A developing unit in an image forming apparatus includes a bearing unit, a first biasing device, a shaft member, and a second biasing device. The bearing unit rotatably supports the respective end portions of the developing roller and the magnetic roller. The first biasing device biases the bearing unit in a direction to cause the developing roller to move toward the image carrier. The shaft member causes the bearing unit to swing by moving in a front-back direction. The second biasing device biases the shaft member in a forward direction. A cover unit of the image forming apparatus presses the shaft member backward by pivoting from an open position to a closed position, and draws out the shaft member in the forward direction by pivoting from the closed position to the open position.

The present disclosure relates to an image forming apparatus and a developing unit.
An image forming apparatus based on electrophotography includes a photoconductor drum on which a toner image is formed, and a developing unit for supplying the toner to the photoconductor drum. The developing unit includes a developing roller disposed close to and parallel to the photoconductor drum.
The developing unit is removably installed in the main body of the image forming apparatus. However, since the developing roller is located close to the photoconductor drum as stated above, the developing roller may contact the photoconductor drum in a mounting or removing process of the developing unit.
Accordingly, some image forming apparatuses are configured to move the developing roller away from the photoconductor drum before the developing unit is removed from the main body (technique A).
According to the technique A, the developing unit includes a housing, a developing roller and a magnetic roller disposed parallel to each other, and a bearing unit rotatably supporting the respective end portions of the developing roller and the magnetic roller.
The bearing unit is disposed to swing about the axial center of the magnetic roller, together with the developing roller. The bearing unit is biased by a first spring, so that the developing roller is abutted against the photoconductor drum. An arm member is provided in the vicinity of the magnetic roller of the bearing unit.
The housing includes a shaft member movably extending in the axial direction of the magnetic roller. The shaft member is biased by a second spring so that an end portion sticks out from the housing. The shaft member reciprocally moves in contact with the arm member, so as to cause the arm member and the bearing unit to swing about the axial center of the magnetic roller.
The main body includes a holder unit on which the developing unit is mounted, and an openable cover unit located forward of the holder unit.
Upon closing the cover unit with the developing unit mounted on the holder unit, the end portion of the shaft member which has been sticking out is abutted against the rear face of the cover unit and made to retreat against the biasing force of the second spring. At this point, the arm member and the bearing unit are made to swing by the movement of the shaft member, and the developing roller is pressed and abutted against the photoconductor drum by the biasing force of the first spring.
Conversely, upon opening the cover unit the shaft member is allowed to stick out forward by the biasing force of the second spring. Because of such movement of the shaft member, the arm member and the bearing unit are made to swing against the biasing force of the first spring, and therefore the developing roller moves away from the photoconductor drum.


The present invention relates generally to molecular assemblies, more particularly to an assay for the detection of G-protein coupled receptor (GPCR) molecular assemblies and bead-based detection of ligand-GPCR complexes and to methods for identifying compounds as agonists, partial agonists or antagonists of the binding of G-protein coupled receptors to G-protein and for use of these compounds in the treatment of conditions or disease states in a mammalian subject or patient, including humans, where G-protein coupled receptor binding to G-protein is implicated.

G protein coupled receptors (GPCRs) transmit extracellular signals into cells via intracellular G protein heterotrimers (1). Of currently marketed drugs, more than 30% modulate GPCRs (2). Only 10% of the 367 human endogenous ligand GPCRs are targeted by current drugs, leaving many future targets. Novel modes of defining the activity of ligands that bind to GPCRs could contribute to the treatment of human disease.
The response to epinephrine or adrenaline is a prototypic GPCR action. Equilibrium binding studies in frog erythrocyte membranes demonstrated homogeneous binding for antagonists, while agonists exhibited two states of agonist affinity (3). The ternary complex model of agonist, receptor, and G protein accounts for the ternary complex exhibiting a higher agonist affinity than the binary complex (4). Adenylyl cyclase assays define the intrinsic activity, or efficacy, for each compound. Receptors in the high affinity state range from 50% for agonists of the lowest intrinsic activity to 95% for full agonists, the percent correlated roughly with the intrinsic adenylyl cyclase activity of the agonist. The functional consequences of cellular ternary complex formation include the rapid binding of GTP to the Gα subunit, release of the receptor and the Gβγ dimer, and exposure of new Gα and Gβγ surfaces to interact with effectors such as adenylyl cyclase (5). Ternary complex formation for a series of agonists is expected to correlate with adenylyl cyclase activities. More detailed ternary complex formulations take into account the idea that receptors can exist in different activity states (6).
The present inventors have previously studied the formyl peptide receptor and its numerous fluorescent ligands. The solublilized receptor forms a high agonist affinity complex with G proteins and arresting. See, Bennett, et al., 2001 J. Biol. Chem. 276, 22453–22460; Bennett, et al., 2001, J. Biol. Chem. 276, 49195–49203; and Key, et al., 2001, J. Biol. Chem. 276, 49204–49212. Beads derivatized with chelated nickel bind hexahistidine-tagged G protein heterotrimers, and as shown by flow cytometry, form ternary complex with FPR constructs on G protein beads. The constructs included wild type receptor detected with fluorescent ligand, receptor-Gα fusion protein detected with fluorescent ligand, and receptor-GFP fusion protein detected with nonfluorescent ligand See, Simons, et al., 2003, Mol. Pharmacol. 64, 1227–1238. The technology demonstrated also includes one of the receptors for adrenaline, the beta 2 adrenergic receptor (β2AR), which was used in the form of a fusion protein with green fluorescent protein, the β2AR-GFP fusion protein. A well-known β2AR ligand was attached to beads, and the formation of ligand:receptor binary complexes was detected by increasing fluorescence of the beads, in a process analogous to affinity chromatography. As with the FPR-GFP, β2AR-GFP was able to bind cognate agonists to form agonist:receptor-GFP binary complexes, which in turn were able to bind to cognate hexahistidine-tagged G protein on chelated nickel beads to form ternary agonist:receptor-GFP:G protein complexes on chelated nickel beads. These complexes were also detected by increasing fluorescence of the beads.
The interactions of ligands with GPCRs have mainly been studied in membrane preparations with radiolabelled ligands (e.g., see references 3 and 4 for the β2AR), which are not amenable to high throughput screening. Therefore, appropriate tools in these areas have been limited and, in many situations, unsatisfactory. Thus, there is a need for a homogeneous, small volume bead-based approach compatible with high throughput flow cytometry, which would allow evaluation of G protein coupled receptor molecular assemblies. The present approach provides a general solution for addressing that need.

Multiplex analysis for high throughput discrimination of GPCR agonists and antagonists


The rivet gun has a barrel, a handle, an inflator, a piston assembly and at least one buffer device. The piston assembly has a piston rod and a piston head. The at least one buffer device is mounted in the piston head and has a housing, a valve stem and a buffer spring. The housing has an inserting hole and a side hole communicating with the inserting hole. The inserting hole has a valve opening. The valve stem is movably mounted in the valve opening. A valve part is formed on a lower end of the valve stem to selectively close the valve opening. The buffer spring is mounted around the valve stem. When the piston head moves upward, the buffer spring absorbs some momentum produced by the high pressure gas to mitigate shake caused by the high pressure gas directly hitting the piston head.

1. Field of the Invention
The present invention relates to a rivet gun and more particularly to a rivet gun having one or more buffer devices.
2. Description of Related Art
With reference to Taiwan patent application No. M400369, a rivet gun is used to rivet a rivet in two boards to fix the two boards together. A rivet usually has a head and a shaft connected to the head, and the shaft is usually longer than the head.
A rivet gun usually has a barrel, a handle, a trigger, an inflator and a piston assembly. The barrel has a rivet assembly mounted inside the barrel. The handle extends vertically and downwards from the barrel and has a gas channel formed in the handle. The trigger is mounted on the handle and connected to the gas channel. The inflator is mounted on a bottom of the handle and connected to the rivet assembly to actuate the rivet assembly by hydraulic pressure. In addition, the inflator can be connected to a high pressure gas source to inflate a high pressure gas into the barrel for ejecting a shaft of a rivet out of the barrel. The piston assembly is movably mounted in the inflator and has a piston rod and a piston head connected to the piston rod. A through hole is formed through the piston head through which an inserting tube is mounted. The inserting tube is connected to the bottom of the handle.
When the rivet gun is used to rivet a rivet, the rivet penetrates through two boards, and then the trigger is pulled. A head of the rivet abuts a front end of the barrel and is clamped by the rivet assembly. Meanwhile, the head of the rivet is pressed by the barrel and becomes T-shaped to fix the rivet on the boards. Simultaneously, the high pressure gas of the high pressure gas source is inflated into the barrel, a backward suction is formed and a section fractured from a shaft of the rivet is ejected out from a rear end of the barrel by the backward suction.
The piston head of the piston assembly of the rivet gun is disc-like and contacts an inner wall of the inflator in an air tight manner to divide an inner space of the inflator into an upper air chamber and a lower air chamber. However, the piston head is solid, thus, when the trigger is pulled for riveting, the high pressure gas inflates into the lower air chamber, such that the piston head moves upward. The piston head is suddenly pushed by the high pressure gas and shakes, and noise is produced by the piston head. On the contrary, when the riveting is finished, the piston head moves downward, but the lower air chamber still contains air, such that the piston head cannot move to a bottom of the inflator immediately.


A UE operating in a RAN may be configured to receive new radio, NR, radio resource control, RRC, messages from a secondary network node. The NR RRC messages may each contain a number that the secondary network node added to the NR RRC messages to indicate their respective order in a sequence which the NR RRC messages were sent by the secondary network node. The NR RRC messages may each contain parameters that the UE uses to configure its communications through a NR interface with the secondary network node. The UE may send NR RRC complete messages toward the secondary network node responsive to receipt of the NR RRC messages, wherein the NR RRC complete messages each contain an indication of the NR RRC message that was received. The UE may control the sending of the NR RRC complete messages to indicate to the secondary network node whether the NR RRC messages are received in an order that is the same as the sequence.

In LTE, the Radio Resource Control (RRC) protocol is used to configure/setup and maintain the radio connection between the user equipment (UE) and the enhanced NodeB (eNB). When the UE receives an RRC message from the eNB, it will apply the configuration (where the term "compile" refers to the application of the configuration to control communications), and if this succeeds the UE generates a RRC complete message that indicates the transaction ID of the message that triggered this response.
E-UTRAN supports Dual Connectivity (DC) operation whereby a multiple Rx/Tx UE in RRC_CONNECTED is configured to utilize radio resources provided by two distinct schedulers, located in two eNBs (radio base stations) connected via a non-ideal backhaul over the X2 interface (see 3GPP 36.300). "Non-ideal backhaul" implies that the transport of messages over the X2 interface between the nodes may be subject to both packet delays and losses.
eNBs involved in DC for a certain UE may assume two different roles: an eNB may either act as an MN (Master node), also referred to as Master eNB (MeNB) or as an SN (Secondary node), also referred to as Secondary eNB (SeNB). In DC a UE is connected to one MN and one SN.
In LTE DC, the radio protocol architecture that a particular bearer uses depends on how the bearer is setup. Three bearer types exist: MCG (Master Cell Group) bearer, SCG (Secondary Cell Group) bearer, and split bearers. RRC is located in the MN and SRBs (Signaling Radio Bearers) are always configured as MCG bearer type and therefore only use the radio resources of the MN. When a node acts as an SN, the LTE DC solution does not have any UE RRC context of that UE and all such signaling is handled by the MN.
FIG. 1 is a block diagram of a LTE system having a MN node 100 and a SN node 110, and illustrates the related DC User Plane (UP). The MN and SN nodes 100,110 include Packet Data Convergence Protocol (PDCP) modules 102, Radio Link Control (RLC) modules 104, and Media Access Control (MAC) modules 106. The PDCP module 102 of the MN node 100 handles the split bearer and communicates with a RLC module of the SN node 110.
FIGS. 2 to 4 show the UP and Control Plane (CP) architectures for LTE-New Radio (NR) tight interworking. In particular, FIG. 2 shows a MN node 200 and a SN node 210 configured for LTE-NR tight interworking, and illustrates the User Plane (UP). FIG. 3 shows a MN node 300 and a SN node 310 configured for split bearer for Control Plane in 5G. FIG. 4 shows a control plane architecture for LTE-NR tight interworking, and illustrates control flow between the modules.
The MN and SN nodes disclosed herein can apply various radio interface technologies. The MN node can apply e.g. LTE or New Radio interface (NR), and the SN node can also use either LTE or NR. Other technologies could also be used over the radio interface. The 3GPP technical report TR 38.304 includes various scenarios and combinations where the MN and SN are applying either NR, LTE or both.
For the first phase of 5G standardization and 5G deployment, the most likely scenario is that MN will apply LTE, and the SN will apply the New Radio interface currently being under standardization. The terms master eNB (MeNB) and Secondary NG Base Station (SgNB) are therefore used, without limitation, to refer to network nodes herein.
As already mentioned above, the DC approach introduced for 5G standardization includes a solution for split bearers for signaling radio bearers (SRBs), see FIGS. 3 and 4. The intent of introducing such "RRC diversity" is to enable, e.g., improved mobility robustness and improved message delivery between the infrastructure and the UE. For example, it is then possible to send a handover message or any other reconfiguration message over the best link, even if one of either the link or links to the MeNB (or SgNB) has deteriorated significantly. It is also possible to send duplicates of the same message over both MeNB and SgNB to achieve a better success-rate and faster delivery of the concerned message; in case the links are error prone. Such benefits of "RRC diversity" is not available in the current LTE DC solution, and 3GPP has therefore undertaken the challenge to enable such RRC diversity. Having RRC diversity may prove particularly important for ultra-reliable connections with low latency, often called URLLC (Ultra Reliable Low Latency Communication).
As can be seen in FIG. 4, RRC messages generated/transmitted from the master node (MN) 400 can be sent either via the MeNB, or relayed over an X2 interface to the SgNB 410. The messages received over the different paths in the UE 420 are then combined by the LTE PDCP and then forwarded to the LTE RRC receiving entity and processed further. In the uplink, the UE 420 generates LTE RRC messages that it may transmit either over the NR radio interface towards the SgNB 410 or via the MeNB node 400 using LTE technology. Messages received in the SgNB 410 are then forwarded over an X2 interface towards the MeNB node 400.
Another control signaling mechanism (in addition to direct SRB and split SRBs) in LTE-NR tight interworking is using embedded RRC also illustrated in FIG. 4. Embedded RRC is employed for two cases:                1. When direct SRB is not available and the SgNB has to configure the UE that affects only the NR leg.        2. The UE has to be configured with settings that affect both the NR and LTE legs (i.e. co-ordination is required), even if direct SRB is available.
For the first case, the SgNB sends the RRC message to the MeNB via the X2 interface, which the MeNB then embeds in its own RRC message and sends via SRB1 (which could be split or not). The UE will then be able to extract the embedded NR RRC message from the container MeNB RRC message and apply the configurations on the NR leg for communications with the SgNB. In the UL direction, the UE embeds the NR RRC messages in an LTE RRC message towards the MeNB, and the MeNB will extract the embedded NR RRC message from this and forwards it to the SgNB via the X2 interface.
For the second case, i.e. messages/configurations that require coordination between the MeNB and SgNB (e.g. inter-RAT measurement configurations, settings affecting buffer sizes which the UE has to allocate to the NR and LTE legs without exceeding the total buffering capability of the UE, etc.), the SgNB node can send the NR configurations, the MeNB and SgNB can negotiate the final configurations (as it affects the settings of both legs), and the MeNB sends the final configuration to the UE via an LTE RRC message.
Due to this possibility of sending RRC messages between the SgNB and UE via the two different paths, i.e. one path being an NR RRC message embedded in an LTE RRC message and sent via the MeNB and another path being an NR RRC message that is sent directly from/to the SgNB via direct SRB, a race condition problem could arise due to the out of order reception of messages sent via these two paths.

Methods and operations by network nodes and user equipments


A method of controlling an electric power steering system is provided. The method includes: determining a scale factor based on a handwheel position; applying the scale factor to a hand wheel torque value to scale the hand wheel torque value; and generating a corrected handwheel torque signal based on the scaled hand wheel torque value.

The subject invention relates to methods and systems for controlling harmonic pinion torque correction in steering systems.
Steering systems often have unwanted variations in the amount of steering torque that must be applied by a driver. One source is the phasing of the upper and lower cardan joints on an intermediate shaft. Cardan joints phasing imperfections will cause a cyclical variation in the steering torque applied by a driver that repeats every 180 degrees of the steering wheel. A goal in the design of any steering system is to eliminate, or at least minimize, unwanted steering torque variations that are felt by a driver. The best approach to eliminate these torque variations is to eliminate or minimize them at the source, however, due to various limitations and trade-offs, torque variations will always be present to some degree.
Accordingly, it is desirable to provide systems and methods for correcting torque variations.

Steering Solutions IP Holding Corporation


A head gimbal assembly comprising a slider having a read\write sensor; a suspension to load the slider; a micro-actuator; wherein the micro-actuator comprises a piezoelectric unit with two piezoelectric elements and a support base having a base to be coupled with the suspension physically, a moving plate to be coupled with the two piezoelectric elements, and a leading beam to connect with the base and the moving plate. Also disclosed is a micro-actuator comprising inter alia a piezoelectric unit with two piezoelectric elements. A method of forming a micro-actuator is also disclosed, which method comprising forming a piezoelectric unit having two piezoelectric elements; forming a support base having a base, a moving plate, and a leading beam to connect with the base and the moving plate; and bonding the piezoelectric unit to one side of the support base. Also disclosed is a method of forming a slider, a suspension and a micro-actuator.

Disk drives are information storage devices that use thin film magnetic media to store data. Referring to FIGS. 1a and 1b, a typical disk drive in prior art has a drive arm 104 with a slider 203 mounted thereon and a magnetic disk 101. The disk 101 is mounted on a spindle motor 102 which causes the disk 101 to spin and a voice-coil motor (VCM) (not shown) is provided for controlling the motion of the drive arm 104 with the slider 203 and thus controlling the slider 203 to move from track to track across the surface of the disk 101 to read data from or write data to the disk 101.
However, Because of the inherent tolerance (dynamic play) resulting from VCM that exists in the placement of the slider 203, the slider 203 can not attain a position fine adjustment.
To solve the above-mentioned problem, piezoelectric (PZT) micro-actuators are now utilized to modify the placement of the slider. That is, the PZT micro-actuator corrects the placement of the slider on a much smaller scale to compensate for the tolerance of VCM and the drive arm 104. It not only enables a smaller recording track width, but also increases the 'tracks per inch' (TPI) value and the surface recording density of the disk drive.
Referring to FIGS. 1c, 1d, a traditional PZT micro-actuator 205 has a ceramic U-shaped frame 297. The U-shaped frame 297 comprises two ceramic beams 207 with two PZT pieces (not shown) on each side thereof. The PZT micro-actuator 205 is physically coupled to a suspension 213, and there are three electrical connection balls 209 (gold ball bonding or solder bump bonding, GBB or SBB) to couple the micro-actuator 205 to the suspension traces 210 in one side of the ceramic beam 207. In addition, there are four balls 208 (GBB or SBB) to couple the slider 203 to the suspension 213 for electrical connection. FIG. 2 shows a detailed process of inserting the slider 203 into the micro-actuator 205. The slider 203 is bonded with the two ceramic beams 207 at two points 206 by epoxy dots 212 so as to make the motion of the slider 203 independent of the drive arm 104 (See FIG. 1a).
When power supply is applied through the suspension traces 210, the PZT micro-actuator 205 can expand or contract to cause the U-shaped frame 297 deform and then make the slider 203 rotate along a radial direction on the disk 101. Thus a position fine adjustment can be attained.
However, a head gimbal assembly (HGA) 277 (see FIG. 1c) with the micro-actuator 205 is very difficult to manufacture. First, inserting and bonding the slider 203 to the micro-actuator 205 is difficult. Secondly, the epoxy dot 212 is very difficult to control, if the length of the epoxy dot 212 is too long, it will affect the work performance of the micro-actuator 205, for example, the displacement is not enough; if the length of the epoxy dot 212 is too short, the bonding strength will not be enough and then the shock performance is poor. In addition, the height of the epoxy dot 212 is also difficult to control, if the epoxy dot 212 is too high, the epoxy dot 212 will stay on the front or back side of the slider 203. The epoxy dot 212 staying on the front side of the slider 203 will influence the slider 203 flying on the disk 101 and even damage the slider 203 or the disk 101; The epoxy dot 212 staying on the back side of the slider 203 will influence the GBB process of the slider 203.
Additionally, the micro-actuator 105 has an additional mass which not only influence the static performance, but also influence the dynamic performance of the suspension 213, such as the resonance performance, so as to reduce resonance frequency and increase the gain of the suspension 213.
Also, because the U-shaped frame 297 of the micro-actuator 205 is very brittle, it has a poor shock performance. In addition, it is also a big problem that there is no effective method to identify potential micro cracks of the U-shaped frame 297. Furthermore, due to the variations of voltage applied to the PZT micro-actuator, the back and forth bending of the brittle micro-actuator 205 will generate particles and influence the work performance of the micro-actuator 205.
In the manufacturing process of HGA 277, since the HGA 277 has a complex configuration, the slider 203 must tilt during the bonding of the slider 203 to the U-shaped frame 297, and the U-shaped frame 297 must tilt during the bonding of the U-shaped frame 297 with the slider 203 to the suspension 213. Both will influence the static attitude of the HGA 277 and accordingly increase the difficulty of manufacturing the HGA 277.
It is well known that polishing is a more effective and widely used cleaning method for the micro contamination in the air bearing surface (ABS) of the slider. However, this cleaning method cannot be used in the above-mentioned HGA 277 because it is easy to damage the U-shaped frame 297 of the micro-actuator 205.
Finally, since the slider 203 is supported by the ceramic U-shaped frame 297, it is difficult to ground the slider 203 and suspension to get an electro static discharge (ESD) protection. Also, it is a waste of energy that a bigger drive voltage (40V, AC p—p) is required for operate the PZT micro-actuator 205.
Hence it is desired to provide a micro-actuator, head gimbal assembly and manufacturing method thereof which can overcome the foregoing drawbacks of the prior art.

Micro-actuator, head gimbal assembly and manufacturing method thereof


An electromechanically actuated vehicle brake having a hydraulically and/or mechanically actuated piston and at least one spindle-nut-arrangement. The invention further relates to a piston. To prevent unnecessary play, vibration, noises between adjacent components it is proposed that in the area of a coupling between the spindle-nut-arrangement and the piston at least one compensating element be provided, which prevents unwanted component oscillations.

Electromechanically actuated vehicle brakes are fundamentally known. Aimed at providing an efficient wheel brake of compact and lightweight construction, an electromechanical actuator comprises an electric motor and a multistage transmission, which serves to gear down an electromotive rotational drive movement from an electric motor of relatively lightweight and compact design, and to convert this geared-down rotational drive movement into the required translational movement in order to generate braking forces. To this end, the transmission comprises a spindle-nut-arrangement, which translates the rotational movement into a translational movement. For this purpose, the electromechanical actuator is attached on a single side to a stub axle-shaped brake housing, which accommodates one or more translationally displaceable pistons on the actuator side. The brake housing is arranged so that it is displaceable in relation to a carrier fixed to the vehicle. Utilizing the reaction forces whilst performing a relative displacement of the brake housing means that a single electromechanical actuator of low weight is in principle sufficient to apply brake linings arranged on both sides of a brake disk to friction surfaces of the brake disk by means of opposing translational movements, and with the required application force of approximately 1800 Newton.
It is often not fully appreciated in this context that for various reasons (application forces, temperature, fouling, operating reliability, weight, wear, ventilation capacity and many other influencing variables of a usual load spectrum) the demands placed on an electrically and hydraulically actuated motor vehicle brake are exceptional in the extreme and also subject to constraints in terms of the acceptable costs. In this context it must also be remembered, in particular, that a wheel brake cannot be regarded as a completely inelastic, rigid construction, but that when subjected to high stress-loading an elastic material behavior is inevitable, that relative changes in the position of adjacent components in relation to one another have to be catered for, and that modified, possibly wider geometrical and positional tolerances may be necessary.
In the case of so-called combined hydraulically and electromechanically actuated vehicle brakes performing an electromechanical parking brake function there is the further special feature that energy for actuation of the brake may be generated both electromechanically, hydraulically, or by a combination of these methods. For this reason, in a force flux between the spindle-nut-arrangement and the piston a releasable coupling is provided, which allows a purely hydraulic actuation without damaging or having a negative reactive effect on the spindle-nut-arrangement.
Known electromechanical parking brakes may have the following problems. Under unfavorable conditions in which the actuator travel is extended (thermal expansion, worn friction pairings or the like), rattling noises can be generated when running over rough roads. It has been determined through analysis that some of the causes of such rattling noises are to be sought primarily in the area of the components of the electromechanical actuators. This is because the dimensioning of inevitable geometrical and positional tolerances, clearance fits, particularly of a movement in a radial direction between components of the electromechanical actuators on the one hand and the piston on the other, are a source of these noise problems. A further finding was that the effects prompting complaints result in particular from oscillation phenomena in the area of a coupling between the spindle-nut-arrangement and the piston.

Electromechanically actuated vehicle brake having an improved piston


The invention is a method for detecting failures in an analyzer for conducting clinical assays. Potential errors that can result in assay failures in an analyzer are identified, as are their potential sources. The probability that an error source so identified will result in a clinically significant error is also determined. Available potential detection measures corresponding to the source of potential errors are identified with a combination of such measures selected and implemented based on their probability of detecting such errors within an acceptable limit with a concomitant low probability of the false detection of an assay failure. Each of the measures selected are functionally independent of others chosen to address the source of the error and are not subject to the same inherent means of failed detection. Applications of the method in a clinical analyzer are also presented.

The invention relates to analyzers for conducting a range of clinical assays.
Automated analyzers are a fixture in the clinical laboratory. Assays that used to require significant manual human involvement are now handled largely by loading samples into an analyzer, programming the analyzer to conduct the desired tests, and waiting for results. The range of analyzers and methodologies in use is large. Some examples include spectrophotometric absorbance assay such as end-point reaction analysis and rate of reaction analysis, turbidimetric assays, nephelometric assays, radiative energy attenuation assays (such as those described in U.S. Pat. Nos. 4,496,293 and 4,743,561 and incorporated herein by reference), ion capture assays, colorimetric assays, fluorometric assays, electrochemical detection systems, potentiometric detection systems, and immunoassays. Some or all of these techniques can be done with classic wet chemistries; ion-specific electrode analysis (ISE); thin film formatted "dry" chemistries; bead and tube formats or microtiter plates; and the use of magnetic particles. U.S. Pat. No. 5,885,530 provides a description useful for understanding the operation of a typical automated analyzer for conducting immunoassays in a bead and tube format and is incorporated herein by reference.
Despite the array of different analyzer types and assay methodologies, most analyzers share several common characteristics and design features. Obviously, some measurement is taken on a sample. This requires that the sample be placed in a form appropriate to the measurement technique. Thus, a sample manipulation system or mechanism is found in most analyzers. In wet chemistry devices, sample is generally placed in a sample vessel such as a cup or tube in the analyzer so that aliquots can be dispersed to reaction cuvettes or some other reaction vessel. A probe or proboscis using appropriate fluidics such as a pumps, valves, liquid transfer lines such as pipes and tubing, and driven by pressure or vacuum are often used to meter and transfer a predetermined quantity of sample from the sample vessel to the reaction vessel. The sample probe or proboscis or a different probe or proboscis is also often required to deliver diluent to the reaction vessel particularly where a relatively large amount of analyte is expected or found in the sample. A wash solution and process are generally needed to clean a nondisposable metering probe. Here too, fluidics are necessary to accurately meter and deliver wash solutions and diluents.
In addition to sample preparation and delivery, the action taken on the sample that manifests a measurement often requires dispensing a reagent, substrate, or other substance that combines with the sample to create some noticeable event such as florescence or absorbance of light. Several different substances are frequently combined with the sample to attain the detectable event. This is particularly the case with immunoassays since they often require multiple reagents and wash steps. Reagent manipulation systems or mechanisms accomplish this. Generally, these metering systems require a wash process to avoid carryover. Once, again, fluidics are generally a central feature in the conduct of these operations.
Other common systems elements include measurement modules that include some source of stimulation together with some mechanism for detecting the stimulation. These schemes include, for example, monochromatic light sources and calorimeters, reflectometers, polarimeters, and luminometers. Most modem automated analyzers also have sophisticated data processing systems to monitor analyzer operations and report out the data generated. Numerous subsystems such as reagent cooler systems, incubators, and sample and reagent conveyor systems are also frequently found within each of the major systems categories already described.
An assay failure, as the term is used in this specification, occurs when an assay result is obtained that is believable yet unacceptably inaccurate and if used as the sole source of clinical data would result in an improper clinical choice (i.e., treatment). Inaccuracies or a loss of precision can occur as a result of an almost endless list of factors such as mechanical noise or even inefficient programming protocols. Most of these are relatively easy to address. However, with analyte concentrations often measured in the μg/dL, ng/dL, or even MlU/L range, special attention must be paid to sample and reagent manipulation systems and those supporting systems and subsystems that affect the sample and reagent manipulation systems. The sample and reagent manipulation systems require the accurate and precise transport of small volumes of liquids and thus generally incorporate extraordinarily thin tubing and vessels such as those found in sample and reagent probes. Most instruments require the simultaneous and integrated operation of several unique fluid delivery systems, each one of which is dependent on numerous parts of the hardware/software system working correctly. Some parts of these hardware/software systems have failure modes that may occur at a low level of probability. A defect or clog in such a probe can result in wildly erratic and inaccurate results and thus be responsible for assay failures. Likewise, a defective washing protocol can lead to carryover errors that give false readings for a large number of assay results involving a large number of samples. This can be caused by adherence of dispensed fluid to the delivery vessel (e.g., probe or proboscis). Alternatively, where the vessel contacts reagent or diluent it can lead to over diluted and thus under reported results. Entrainment of air or other fluids to a dispensed fluid can cause the volume of the dispensed fluid to be below specification since a portion of the volume attributed to the dispensed fluid is actually the entrained fluid.
One method of ameliorating failures is through the detection of system errors. Once detected, unacceptable results can be appropriately dealt with or discarded and can prevent an improper clinical choice. The instrument can be made to provide an error message, discard unreliable results, cease further processing of a sample assay, perform an additional or confirmatory assay, or conduct further instrument diagnostics by virtue of mechanical/hardware systems or by software driven protocols for dealing with the errors. For example, liquid level sensors are frequently used to detect whether sample volume dispensed into a cuvette is sufficient to conduct an assay. The volume of cuvette contents is then incorporated into an algorithm within the system software. If it falls below a predetermined level, the algorithm instructs the instrument not to continue the assay and to generate a message indicating that the sample volume is insufficient to conduct the test requested for that sample.
Indeed, given enough effort, it is often possible to consider a range of possible detection schemes to attack targeted failure modes. Within a given set of possible detection schemes various degrees of robustness or probability of detecting the failure mode will be available. Setting the detection threshold high enough to catch all failures will likely catch many non-failures. This is a serious system reliability and cost concern. In an emergency room environment, failure to report a result promptly can put the patient at risk. Thus, a dilemma can arise in which failure modes can be determined as well as a range of possible detection schemes for each of the failure modes yet implementation of each detection mode is also unacceptable. Selecting the proper combination of failure detection modes to reduce failure rates to an acceptable level with a concomitant low level of risk that an acceptable result will not be discarded is thus a formidable challenge.
U.S. Pat. No. 5,646,049 describes a system of scheduling operations in an automated analyzer. Sources of carryover and contamination are analyzed and addressed by sequencing various steps (e.g., pipetting and wash steps) in the analysis scheme to minimize their impact. The software establishes a matrix to identify when carryover or contamination is likely, based upon preceding and succeeding pipetting steps scheduled by the scheduler software. The apparatus and method, based upon values from the matrix corresponding to the preceding and succeeding pipetting steps, causes the analytical system to respond with appropriate wash characteristics to eliminate the possibility of undesirable carryover or contamination when they appear likely. The matrix identifies whether or not a step is likely to introduce an error such as carryover. There is no quantification of the probability that such an error will occur and the probability that the error will have particular clinical significance or the extent of the error. In other words, potential error sources are addressed as individual events and not as having a compounding effect.
Under the FDA's Quality System Regulations for Medical Devices, developers of diagnostic equipment must go through a process to identify and rank potential system hazards, assess probability and severity, mitigate the high level hazards and quantify the new level of the mitigated risk. Hazard Analysis and Failure Modes and Effects Criticality Analysis are tool commonly used in the industry. Redesign of the system may be able to reduce the probability of a risk to a level where the possibility of occurrence is extremely remote. Often, it is necessary to add systems to detect the occurrence of the failure and prevent the reporting of the result associated with that occurrence.
The typical practice in the diagnostic industry is to design a detection system to detect a specific failure mode. Occasionally, the detection system may detect multiple failure modes, but that situation is more by good fortune rather than by intent. If the effect of a failure mode is an assay failure as defined earlier, the detection system must be tuned to a very high level of effectiveness. This tuning usually leads to serious difficulties.
Firstly, the detection system may cause potentially good results to be discarded. A population of the parameter being monitored, e.g. distance, volume, voltage, will likely exhibit a normal, Gaussian distribution with the aim point for the parameter, hopefully, at the center of the distribution. In a typical system, the parameter could vary around the set point by plus or minus 3 or 4 standard deviations without negatively effecting the final result. The detection system will also have some inherent measurement error or noise, such that repeated measurements of the same parameter will also form a normal distribution with the center of the distribution, hopefully, at the desired detection limit for the parameter. In almost all cases, the detection system must perform its function without effecting the parameter. For instance, volume measurements must take place without contaminating the fluid, temperature measurements must not alter the temperature of the object being monitored. Also, the detection system must work within timing and cost constraints of the instrument. The net effect of these limitations is that the measurement error may be significantly higher than may be desired. In other words, the normal curve represented by the detection system is wide. When the placement of the detection limit relative to the parameter set point causes the two normal distributions to overlap, the area under the intersection of the curves represents the cases where parameters that could yield valid results will be discarded by the detection system. The cost of achieving a high level of effectiveness for the detection system is a high number of discarded good results.
Secondly, the cumulative effect of multiple detection systems with respect to false positives, i.e. discarded good results, is additive. The more detection systems within a diagnostic instrument, the higher the number of false positives. If each significant failure mode had a separate detection system, the total number of detection systems would be high. In many cases, a detection system for a particular failure mode would require additional hardware. This adds more cost and further-degrades instrument reliability.
Thirdly, another consideration is the cost of developing highly effective detection systems. For example to verify that a detection system has achieved a effectiveness of 99.9% or better, a run of more than 4600 tests must be free of any of the errors being evaluated. Preferably, this test should be performed on multiple instruments. Verifying higher levels of effectiveness can become impractical in terms of time and cost.
It can be seen that it would be highly desirable to achieve high detection effectiveness by some other way than by attacking each failure mode individually.
The accuracy and precision of automated clinical analyzers can be improved by considering the cooperative effects of improvements in the sample and reagent manipulation systems and implementing those improvements in the components of those systems. Such an approach would also suggest new operations to reduce errors where the optimization of existing processes (e.g., probe wash steps) would not reduce the probability or extent of an error to the required degree. It would also suggest such new operations where the probability or extent of multiple errors could be better addressed by a nonexistent operation.

Failure detection in automated clinical analyzers


A device to semi-permanently attach suction cup mounts that previously lost functionality is provided. Further, the device provides attachment without marring a mounting surface, or substrate. The present invention consists of a thin barrier preferably metal foil of circular shape with a pressure sensitive adhesive on one side. An additional adhesive is provided to apply between the barrier assembly and a suction cup. This structural barrier assembly provides a cost effective way to make use of nonfunctioning suction cup mounts or mounted devices without replacing the mount or device.

1. Field of Invention
The present invention relates generally to suction cups and, more particularly, to a device that retains suction cup attachments in a semi-permanent manor.
2. Prior Art
Suction cups can be found in nature on animals such and octopuses and squids. Artificial suction cups may have been created and used by humans as far back as the 3rd century, BC. Suction cups for use in temporarily securing devices are well known in the art. A portable bracket made use of a suction base in around 1882. See U.S. Pat. No. 276,336 (Baumeister). A hook attached to a suction cup was conceived in around 1888. See U.S. Pat. No. 435,752 (Intersoll). In around 1931, they were put to use holding notes in place. See U.S. Pat. No. 1,839,694 (Nelson and Bahr). Although suction cups have varied throughout history, the basic modern shape is an axisymmetric disc with a concave lower surface and a convex upper surface. A boss of some sort is usually molded into the center of the convex side to provide an attachment point. To improve the holding strength or duration of the suction cup's adherence, variations on this design have been tried. See U.S. Pat. No. 2,055,397 (Zaiger). Non-invasive attachments to rough surfaces such as automobile dashboards have also been attempted through the use of adding gels to the bottom surface of the cup. See U.S. Pat. No. 7,690,609 (Akai). Other designs have tried to mitigate air entering the envelope between the lower concave and mounting surfaces by storing a mild sealing agent within suction cup and having it flow onto contact edges of the disc as it is being affixed to a surface. See U.S. Pat. No. 1,859,893 (Ritz-Woller). Still other designs of suction cups exist that contain un-activated adhesive within the boss. Once activated, the adhesive bonds the bottom of the cup to a mating surface for a permanent bond. The mechanics of holding the cup in place by means of suction is only required while the adhesive is setting. This idea of using a suction cup to temporarily hold an adhesive fastener while curing may have use in industrial applications, although permanent bonding of a suction cup or suction fastener is inappropriate if the mounting surface is to be undamaged. See U.S. Pat. No. 2,432,719 (Braun), U.S. Pat. No. 2,451,194 (Braun) and U.S. Pat. No. 5,044,852 (Sweeney).
Suction cups made of modern elastomer or rubber have been used successfully to attach a variety of components to smooth surfaces in the households and vehicles. When these suction cups are newly manufactured, their strength and duration of attachment is adequate for many lightweight mounting applications. However, the performance of all suction cups diminishes with their age. Contact surfaces become scratched and their shapes become distorted. After a certain amount of degradation, they become completely useless.
3. Objects and Advantages
It is possible to permanently attach a worn out suction cup devices using an appropriate adhesive, however, damage will occur to the substrate or mounting surface. One solution to this problem, and the object of this invention, is an intermediate barrier to which a worn out suction cup can be bonded. This barrier is then attached to a desired surface using a semi-permanent, pressure sensitive adhesive. The barrier is flexible enough to conform to the bottom side of the suction cup as well as smoothly lay against a mounting surface. The edge of this barrier extends radially outward, well beyond the edge of the compressed suction cup to mitigate peel. The major advantage of this solution is that it restores the function of a worn out suction cup or suction cup mount without damaging the mounting surface. It will work to attach a suction mount to any smooth surface that that does not need frequent removal. The barrier device can be made and sold for a much lower cost than purchasing a replacement suction cup mount.
Applicant's assignee manufactures kits to semi-permanently affix worn out suction cup mounted products using a barrier and liquid and pressure sensitive adhesives. For many applications where frequent removal of the suction cup mount is not needed, this can be a cost-effective means to utilize old mounts, saving countless from entering landfills.