A scanning and data acquisition method and apparatus for three dimensional (3D) computerized tomography (CT) imaging of a region-of-interest (ROI) in an object, wherein image reconstruction processing is applied to a plurality of sets of cone beam projection data, each set being acquired on a detector at a corresponding plurality of scan path source positions. A first image reconstruction processing step comprises applying a mask to each set of the projection data to form masked data sets. The mask for each data set is formed by cone beam projections onto the plane of the detector of portions of the source scan path that are above and below the source position that acquired the data set being masked. The next image reconstruction processing step comprises ramp filtering of each masked data set along a plurality of parallel lines formed therein that are parallel with and in the direction of a parallel projection into the data set of a line that is tangent to the scan path at the source position that acquired that data set and in the direction of the next source position, to generate filtered data sets. Each filtered data set is then subjected to a weighted 3D backprojection into a 3D space, thereby reconstructing in a piecewise manner a 3D image of the ROI in the object.

1. Field of the Invention
The invention relates generally to image reconstruction in a cone beam imaging system having a radiation source scan path that encircles an object, and more specifically to the use of a simplified 3D backprojection image reconstruction technique in a cone beam imaging system.
2. Description of the Prior Art
A filtered backprojection (FBP) cone beam image reconstruction technique is described by Kudo, H. and Saito, T., in their article entitled "Derivation and Implementation of a Cone-Beam Reconstruction Algorithm for Nonplanar Orbits", IEEE Trans. Med. Imag., MI-13 (1994) 196-211, incorporated herein by reference.
Briefly, the FBP technique consists of the following steps at each cone beam view (i.e., at each position of the radiation source as it scans about the object, and at which an imaging detector acquires a corresponding set of projection data):
1. Compute a 1D projection (i.e., line integral) of the measured cone beam image acquired on a detector plane 1 at each of a plurality of angles .theta.. This step is illustrated by FIG. 1A for a given angle .theta..sub.1 of a plurality of angles .theta., where the projection 2 at coordinates (r,.theta.) comprises the integrated values of the cone beam image 4 on detector plane 1 along plurality of parallel lines L(r,.theta.) that are normal to angle .theta., each line L being at an incremental distance r from an origin O. Generally, if the detector plane 1 comprises an N by N array of pixels, then the number of angles .theta. is typically given by .pi.N/2. PA1 2. Filter each 1D projection in accordance with a d/dr filter, resulting in a new set of values at each of the r,.theta. coordinates, such as shown by filtered projection 6 for the angle .theta..sub.1 in FIG. 1A. PA1 3. Normalize the filtered projections with a normalization function M(r,.theta.). Normalization is needed to take into account the number of times the plane of integration Q(r,.theta.) which intersects the source position and the line L(r,.theta.), intersects the scan path, since the data developed at each scan path intersection creates a contribution to the image reconstruction on the plane Q(r,.theta.). PA1 4. Backproject the filtered projection 6 from each angle .theta. into a 2D object space 7 which coincides with the detector plane 1. This step is illustrated by FIG. 1B, wherein lines 8 spread the value from each r,.theta. coordinate into 2D space 7 in a direction normal to each .theta.. PA1 5. Perform a 1D d/dt filtering of the backprojection image formed in 2D space 7 by step 4. The 1D filtering is performed in the direction of the scan path, i.e., along lines 10, where t points in the direction of the scan path. PA1 6. Perform a weighted 3D backprojection of the resulting data in 2D space 7 (i.e., from each pixel in the detector) onto a plurality of sample points P in a 3D object volume 12. The density assigned to each point P is weighted by the inverse of the square of the distance between the point and the apparent x-ray source (see Equation (59) of the forenoted Kudo et al article).
The above prior art procedure will be referred to hereinafter as the 6-step process. It is assumed in this process that the entire cone beam image of the object is captured on the detector of the imaging system. Consider a plane Q(r,.theta.), which intersects the object, formed by the source and the line L(r,.theta.) on the detector at angle .theta. and at a distance r from the origin. Ignoring the function M(r, .theta.), the operations 1 through 6 compute the contribution to the reconstructed object density on the plane Q(r,.theta.) from the x-ray data illuminating the plane and its immediate vicinity. Since the 6-step process is detector driven, a contribution from the data illuminating the plane is computed every time the plane intersects the scan path and thus is illuminated by the x-ray beam. Consequently, the function M(r,.theta.) is used after the filter function in step 2 to normalize the results. Normalization is particularly undesirable since it requires pre-computing and storing a 2D array M(r,.theta.) for each source position along an imaging scan path. Since there are usually hundreds, if not thousands of source positions, this type of normalization is both computationally intensive and resource (computer memory) expensive. In the Kudo et al article, however, at page 203 it is noted that in the special case where the scan path is a circle, steps 1-5 can be simplified into a single convolution step, which essentially comprises ramp filtering the cone beam image in the direction of the scan path. This ramp filtering is equivalent to the well-known Feldkamp algorithm for a single circular orbit, such algorithm being described in particular detail in the article by L. A. Feldkamp, L. C. Davis, and J. W. Kress, entitled "Practical cone-beam algorithm" published in the J. Opt. Soc. Am. A. Vol. 1, 1984, pages 612-619 (see in particular the convolution function equations 15 and 16 at page 614, which describe the convolution function as: ##EQU1## incorporated by reference herein. The key to this simplification is that in the case of a circular scan path, the normalization function M(r,.theta.) is a constant, equal to 2. Consequently, the filtered projection at each r,.theta. that results after step 2, can merely be divided by 2 to compensate for the data redundancy.
It would be desirable to use this simplification for source scan paths other than a single circle, but the Kudo et al article does not provide any indication how this can be done, or that it is even possible.
Furthermore, since the above procedure assumes that the detector captures the entire cone beam image of the object at each view, it can not be applied to a cone beam imager having a short detector, i.e., one that only captures a portion of the cone beam image at each cone beam view. Thus, in its current form, the Kudo et al. FBP technique cannot be applied to a cone beam imager having a spiral scan path and employing a short detector.
It would be desirable to apply the Kudo et. al. image reconstruction processing simplification for a single circle scan imager, to a cone beam imaging system that not only has a spiral scan path, but also uses a short detector.

Simplified cone beam image reconstruction using 3D backprojection


An integrated device package includes a housing having a first opening and a second opening in fluid communication with an interior volume of the housing. A package substrate(s) has a first port and a second port. A first device die is mounted to the substrate(s) over the first port. A second device die is mounted to the substrate(s) over the second port. The substrate(s) is coupled to the housing to cover the first and second openings such that the first device die is disposed within the interior volume through the first opening and the second device die is disposed within the interior volume through the second opening.

1. Field of the Invention
The field relates generally to multi-port device packages, and, in particular, to microphone packages having multiple microphone device dies.
2. Description of the Related Art
Microphone packages are used in many types of electronic devices, such as mobile smartphones, tablet computing devices, medical devices (such as hearing aids), and various other applications. Various microphone device packages include a microphone device die coupled to a package substrate and enclosed within a package lid. The package typically includes a sound port configured to allow sound waves to pass from the outside environs to an interior of the package to interact with the microphone device die. A processor can also be mounted on the substrate to pre-process signals detected by the microphone device die. The lid and/or the substrate can enclose the microphone device die to protect the die from contamination and external forces, and can also act as a radio-frequency (RF) shield to prevent electromagnetic interference. Other types of packages can have similar ports for other types of communication, such as for pressure measurement or optical communication through the package housing.
Despite the widespread use of packages with ports for communication with housed device, there is a continuing effort to improve the functionality and manufacturability of such packages and assemblies.


The following disclosure comprises a medical autotransfusion and blood drainage reservoir for withdrawing blood from the site of an operation under vacuum. A walled reservoir is connected to the operation site and a vacuum is drawn therein to draw fluids from the operation site. Vacuum is provided by a piston pump connected to check valves. The check valves allow for movement of the piston pump in one direction to discharge air therefrom, and in the other direction to withdraw air from the reservoir. Alternatively a spring driven bellows can be used to draw a vacuum with attendant check valves. The inlet of blood flow is through a filter. Blood is then capable of flowing outwardly to be reinfused by autotransfusion or reinfusion at a later time. Vacuum indication means and bleed off valves are included for maintenance of a proper vacuum.

Autotransfusion systems are now widely accepted. The reason why is that there is significant importance placed upon post operative blood collection and reinfusion. Consequently, various systems have been developed to incorporate the collection and reinfusion of blood into a patient's body.
Generally, the withdrawal of blood is under vacuum from an operation site. A preset suction is utilized to pull and drain blood from the operation site. In doing this, there is an effort to maintain red blood cells to protect them from potential hemolysis. Also, efforts are made to protect the tissue from being damaged at the operation site while at the same time insuring proper withdrawal of the blood from the site.
In order to effectuate this, various efforts have been attempted to withdraw the blood into a blood bag and then reinfuse it into a patient's body. The withdrawal is under vacuum which can be provided by a vacuum source such as the normal vacuum within a hospital environment. Such vacuum sources are usually provided through vacuum pumps connected to a series of pipes that can be accessed near a patient's bed or within an operating room procedural area. Also, it is known to drain wound or operation sites without the use of vacuum by merely allowing them to drain into a drainage tube on a gravity basis.
Most autotransfusion devices rely upon pulling blood from a wound or operation site that is suctioned directly into a holding area such as a blood bag or a reservoir. It is oftentimes filtered and mixed with an anti-coagulant and then reinfused directly from the same unit or from a blood bag.
The use of reinfused blood lowers the cost of transfusion from banked blood. This in turn lowers the expense to the patient. Additionally, problems such as typing, screening, risks such as AIDS or cross matching of banked blood is substantially eliminated if reinfused blood is transfused to the patient.
Such systems that are currently available are set forth in various patents. One of these patents is U.S. Pat. No. 4,573,992 entitled An Apparatus For Receiving and Reinfusing Blood by Guenter H. Marx assigned to Solco Basel AG. This particular device incorporates a concertina-like container which once filled is compressed to reinfuse the blood into a patient. In effect, it operates as an expansion chamber withdrawing the blood under vacuum, and then re-compressing the chamber for infusion. The device specifically lacks utility with respect to a constant vacuum source that can be used in adjacent relationship with it. It also lacks proper filters, and an overall configuration that can be adapted for use in an easy and facile manner during autotransfusion with respect to orthopedic operations.
A later development by the assignee of the foregoing patent incorporates an improved reservoir with an inherent vacuum source. However, it lacks a vacuum source and other features that make this invention functional and, capable of being implemented in a facile manner. For instance the vacuum source is a bulb, that when squeezed relies upon the resilience of the rubber in the bulb to expand and provide a vacuum. It furthermore does not provide a multiple displacement vacuum pump function as does this invention.
Another patent, namely U.S. Pat. No. 4,767,417 for a drainage device for collecting liquids from a body cavity assigned to Boehringer Laboratories incorporates a withdrawal system for withdrawing fluids from a wound or operation site. A particular vacuum maintenance regulation chamber is incorporated as well as a blood bag concept. However, in this particular case there is no integrated vacuum system as in the applicant's invention herein of the type necessary to perform an orthopedic autotransfusion function.
U.S. Pat. No. 4,744,785 entitled Autotransfusion System assigned to C. R. Bard sets forth a collection bottle that can be used for salvaging blood and reinfusing it. There is no inference as to an integrated vacuum system that can be utilized as that of the applicants herein.
From a reading of the literature and the general format of the prior art, it is believed that the applicants' invention sets forth an integrated vacuum system which is new and unobvious over the prior art.
The applicants' integrated vacuum system and reservoir as well as the entire autotransfusion system incorporates an integrated vacuum source in the form of a positive displacement manual piston pump. A wall vacuum access port is also provided as an alternative vacuum source. The integrated manual vacuum pump assures portability and a steady source of vacuum at the site through a displacement piston pump means which can be in the form of a syringe. The vacuum is regulated by a regulation system to be within the proper operational norms.
A bellows pump having a spring loaded interiorly expandable chamber with check valves can also serve as an alternative embodiment for this invention.
The invention further incorporates check valves in an arrangement for providing the vacuum and the exhaust by use of the integrated manual vacuum pump. The check valves are particularly adaptable and useful in their configuration and the circuit in which they have been placed.
Integrated filters in the reservoir are provided in order to filter the blood. The filter is emplaced with a pressed fitting and is entrapped on the top and bottom thereby, limiting the requirement for bonding.
A vacuum indicator is provided by this invention to visually indicate the amount of vacuum within the reservoir of the system. This is performed by a rubber bellows or other expandable device that moves an indicator with respect to a pre-established scale.
A filtered release valve and a vent is provided in order to establish a proper vacuum and relief when desired.
Further features include a quick disconnect means with a check valve as well as a blood bag attachment for using a blood bag in conjunction with the reservoir of the system. Also, injection and sampling ports are provided with the option of being able to inject or withdraw fluids such as anti-coagulants into the reservoir.
Based upon the foregoing advantages it is believed that this invention is a significant step over the prior art as to its form and functional features.


Methods for determining quantities of nucleic acid sequences in samples include the steps of amplifying a plurality of known quantities of a nucleic acid sequence in respective calibration samples and an unknown quantity of a nucleic acid sequence in a test sample, in parallel, during a time interval. These samples may be amplified using an isothermal amplification method such as Strand Displacement Amplification (SDA), or a thermal cycling amplification method such as Polymerase Chain Reaction (PCR), for example. Indicia of the quantities of a nucleic acid sequence being amplified in the calibration and test samples are then measured using conventional techniques, at measurement points in the time interval. Steps are then performed to determine for a first potential cutoff level, a corresponding first set of time points in the time interval at which the indicia of the quantities of a nucleic acid sequence being amplified in each of the calibration samples equal the first cutoff level. This step is then repeated for each of a number of different potential cutoff levels so that respective sets of time points in the time interval can be obtained for each potential cutoff level. According to a preferred aspect of the present invention, a step is then performed to determine, relative to a statistical criterion, which of the sets of points in the time interval better satisfies the statistical criterion against the known quantities of a nucleic acid sequence in the calibration samples. A quantity of a nucleic acid sequence in the test sample is then determined based on the set of points determined to better or best satisfy the statistical criterion. The accuracy of the determination can also be improved using a relatively large number of potential cutoff levels.

Quantitative nucleic sequence analysis plays an increasingly important role in the fields of biological and medical research. For example, quantitative gene analysis has been used to determine the genome quantity of a particular gene, as in the case of the human HER-2 oncogene, which is amplified in approximately 30% of human breast cancers. D. J. Slamon et al., Science 235, 177-182 (1987). More recently, gene and genome quantitation have also been used in determining and monitoring the levels of human immunodeficiency virus (HIV) in a patient throughout the different phases of the HIV infection and disease. M. R. Furtado et al., J. Virol. 69, 2092-2100 (1995). It has been suggested that higher levels of circulating HIV and failure to effectively control virus replication after infection may be associated with a negative disease prognosis; in other words, there may be an association between virus level (HIV replication) and the pathogenesis of the disease. M. Paitak et al., Science 259, 1749-1754 (1993). Accordingly, an accurate determination of HIV nucleic acid levels early in an infection may serve as a useful tool in diagnosing illness, while the ability to correctly monitor the changing levels of viral nucleic acid in one patient throughout the course of an illness may provide clinicians with critical information regarding the effectiveness of treatment and progression of disease. Additionally, the determination of virion-associated HIV RNA levels in plasma represents a marker of viral replication with potential widespread applicability in assessment of the activity of antiretroviral therapy. Id.
Several methods have been described for the quantitative analysis of nucleic acid sequences. The polymerase chain reaction (PCR) and reverse-transcriptase PCR (RT-PCR) have permitted the analysis of small starting quantities of nucleic acid (i.e., as little as one cell equivalent). See, e.g., S. Edmands et al. 1994, PCR Methods Applic. 3, 317-19; I. R. Rodriguez et al. 1992, Nucleic Acids Res. 20, 3528. Early reports of quantitative PCR report quantitation of the PCR product, but do not measure the initial target sequence quantity. F. Ferre 1992, PCR Methods Applic. 2, 1-9. In general, these methods involve measuring PCR product at the end of temperature thermal cycling and relating this level to the starting DNA concentration. Unfortunately, the absolute amount of product generated does not always bear a consistent relationship to the amount of target sequence present at the initiation of the reaction, particularly for clinical specimens. Such an "endpoint" analysis reveals the presence or absence of starting nucleic acid, but generally does not provide an accurate measure of the number of DNA targets. Id. Both the kinetics and efficiency of amplification of a target sequence are dependent on the starting abundance of that sequence, and on the sequence match of the primers and target template, and may also be affected by inhibitors present in the specimen. In PCR analysis of RNA samples, variable efficiencies in both reverse transcription and amplification steps are potential sources of variability. For these reasons, comparison of the amount of specimen-derived PCR product to the amount of product from a separately amplified external control standard does not provide a rigorous basis for quantitation.
One specific approach to nucleic acid amplification is to measure PCR product quantity in the log phase of the reaction prior to the plateau. See, e.g., Kellogg et al. 1990, Anal. Biochem. 189, 202-208; S. Pang et al. 1990, Nature 343, 85-89. This method requires that each sample has equal input amounts of nucleic acid and that each sample under analysis amplifies with identical efficiency up to quantitative analysis. A gene sequence (contained in all samples at a relatively constant quantity) can be used for sample amplification efficiency normalization. However, using conventional methods of PCR detection and quantitation, it is extremely laborious to assure that all samples are analyzed during the log phase of the reaction, both for the target gene and the normalization gene.
Another method, quantitative competitive PCR (QC-PCR) has been developed and has also been used widely for PCR quantitation. See, e.g., P. D. Siebert and J. W Larrick 1992, Nature 359, 557-558; M. J. Piatak et al. 1993, BioTechniques 14, 70-81; X. Tan et al. 1994, Biochim. Biophys. Acta 1215, 157-162; L. Raeymaekers 1995, Genome Res. 5, 91-94. QC-PCR relies on the inclusion of a known amount of an internal control competitor in each reaction mixture. The efficiency of each reaction is normalized to the internal competitor. To obtain relative quantitation, the unknown target PCR product is compared with the known competitor PCR product, usually via gel electrophoresis. The relative amount of target-specific and competitor DNA is measured; this ratio is used to calculate the starting number of target templates. Basically, in this kind of analysis, the larger the ratio of target specific product to competitor specific product, the higher the starting DNA concentration. Success of a QC-PCR assay relies on the development of an internal control that amplifies with the same efficiency as the target molecule. However, the design of the competitor and the validation of amplification efficiencies require much effort. In the QC-PCR method of RNA quantitation, a competitive RNA template matched to the target sequence of interest, but different from it by virtue of an introduced internal deletion, is used in a competitive titration of the reverse transcription and PCR steps, providing stringent internal control. See, e.g., A. Rashtchian 1994, PCR Methods. Applic. 4, S83-S91. M. Clementi et al. 1993, PCR Methods Applic. 2, 191-196; M. Becker-Andre 1991, Meth. Molec. Cell. Biol. 2, 189-201; R. K. McCulloch et al. 1995, PCR Methods Applic. 4, 219-226. Increasing amounts of known copy numbers of competitive template are added to replication portions of the test specimen, and quantitation is based on determination of the relative (not absolute) amounts of the differently sized amplified products derived from the wild-type and competitive templates, after electrophoretic separation.
In addition to requiring time-consuming and burdensome downstream processing such as hybridization or gel electrophoresis, these assays are limited in dynamic range (i.e. sensitivity to a range of target nucleic acid concentrations). For example, in competitor assays, the sensitivity to template concentration differences may be compromised when either the target or added competitor DNA is greatly in excess of the other. The dynamic range of the assays that measure the amount of end product can also be limited in that the chosen number of cycles of some reactions may have reached a "plateau" level of product prior to other reactions. See, e.g., L. Raeymaekers, supra. Differences in starting template levels in these reactions may therefore not be well-reflected. Furthermore, small differences in the measured amount of product may result in widely varying estimates of the starting template concentration, leading to inaccuracies due to variable reaction conditions, variations in sampling, or the presence of inhibitors.
In an attempt to reduce the amount of post-amplification analysis required to determine initial nucleic acid quantity, additional methods have been developed to measure nucleic acid amplification in "real time." These methods generally take advantage of fluorescent labels (e.g., fluorescent dyes) that are able to indicate the amount of nucleic acid being amplified, and utilize the relationship between the number of cycles required to achieve a chosen level of fluorescence signal and the concentration of amplifiable targets present at the initiation of the PCR process. For example, European Patent Application No. 94112728 describes a quantitative assay for an amplifiable nucleic acid target sequence which correlates the number of temperature cycles required to reach a certain concentration of target sequence to the amount of target DNA present at the beginning at the PCR process. In this assay system, a set of reaction mixtures are prepared for amplification, with one preparation including an unknown concentration of target sequence and others containing known concentrations (standards) of the sequence. The reaction mixtures also contain a fluorescent dye that fluoresces when bound to double-stranded DNA. The reaction mixtures are thermally cycled in parallel for a number of cycles to achieve a sufficient amplification of the targets. The fluorescence emitted from the reaction mixtures is monitored in real time (i.e. as the amplification reactions occur), and the number of cycles necessary for each reaction mixture to fluoresce to a arbitrary intensity threshold (arbitrary fluorescent value, or AFV) is determined. The number of cycles necessary (CT) for the mixture of unknown nucleic acid to reach the AFV value is then compared to the number of cycles necessary for the known mixtures to reach the AFV value. This method relies on a direct correlation between the number of cycles necessary to achieve a given fluorescence intensity, and the logarithm of concentration of the nucleic acid targets. This relationship is thus used to obtain the initial quantity of target nucleic acid sequence in the mixture of unknown concentration. The method provides for the selection of an arbitrary threshold from which to measure numbers of amplification cycles, in that recorded amplification profiles (amplification curves) are analyzed to find an AFV in which to compare the unknown amplification profiles with the standard amplification profile. However, no particular significance is placed on the initial selection of the AFV or cutoff value, in that an exemplary AFV value is chosen to be in the middle of a range in which all the amplification curves are relatively straight (i.e. in transition from upward exponential amplification to downward curving to an asymptote). Moreover, similar results in nucleic acid quantitation are reported for a fairly broad range of AFV values. One shortcoming of this known method is that below an initial copy number of 10.sup.3 target sequence molecules, the method is unreliable in accurately determining initial concentration. Another shortcoming of this method is that it assumes that the shape of each amplification curve remains the same, regardless of whether or not it really does. Finally, only a few data points near the arbitrary cutoff value are taken to determine the initial target nucleic acid concentration.
C. A. Heid et al. 1996 (Genome Research 6, 986-994) and U. Gibson et al. 1996 (Genome Research 6, 995-1001) report methods of real-time quantitative PCR for DNA and RNA quantitation analysis, respectively. Both assays utilize dual-fluorescence reporter systems and are based on the use of the 5'-nuclease assay described by Holland et al. 1991, Proc. Natl. Acad. Sci. USA 88, 7276-7280. In these methods, a computer algorithm generates an amplification plot by comparing the amount of reporter dye emission with the number of amplification cycles that have occurred. The algorithm calculates the cycle (C.sub.T) at which each PCR amplification reaches an arbitrarily selected (i.e. usually 10 times the standard deviation of the baseline) threshold or cutoff. The relative fluorescent emission threshold is based on the baseline of the reporter dye emission during the first 10-15 amplification cycles. It was demonstrated that the calculated C.sub.T value is proportional to the number of target copies present in the sample. Thus, the C.sub.T value is found to be a quantitative measurement of the copies of the target found in any sample.
As indicated by the foregoing discussion, the prior art teaches that one way to perform quantitative analysis of real-time nucleic acid amplification is to select a number of readings just above and below a chosen cutoff level, fit a linear regression to these points, and solve for the "cycle number" at which the fitted line crosses the cutoff level. The selection of a cutoff level is accordingly somewhat arbitrary, as in selecting a cutoff level about 10 times that of a baseline value, or the maximum value of non-target containing samples, or a certain cutoff level above what has been considered acceptable "noise." One shortcoming of such a cutoff selection criteria is that if the cutoff value corresponds to a time point in the amplification during which the amplification rate is changing (i.e., early in the amplification), a linear fit to the data will be inappropriate.
It has heretofore not been appreciated that small differences in the selection of cutoff levels used in quantitation algorithms may have a substantial effect on the ultimate quality (i.e., accuracy) of quantitation. There remains a need to provide an objective and automatic method of selecting preferred cutoff values that will allow users of amplification methods to determine the initial concentrations of target nucleic acids more accurately and reliably than present methods. There also remains a need to provide for methods of determining dynamic cutoff levels that can be easily varied from one experiment or determination to another.

Method, apparatus and computer program products for determining quantities of nucleic acid sequences in samples


A backup volatile state retention circuit is provided with low leakage current for employment with a volatile memory circuit to store the value of the latter during power down of the volatile circuit or during power-down or inactivation of neighboring or peripheral circuits or due to the loss of power of any of these circuits. An example of such a volatile circuit is a memory circuit having volatile memory cells such as employed in dynamic memory core, in particular, a random access memory (RAM) in CMOS circuitry.

A. Technical Field
The present invention relates generally to digital circuit design, and more particularly, to the design of volatile circuits that contain volatile data states that may be lost without the continued application of applied power. An example of such a volatile circuits are digital memory circuits capable of retaining the data state of each memory cell during power-down periods in which the primary power source for the memory circuit is uncoupled from the memory circuit or, otherwise, interrupted or rendered inactive to the memory circuit. A particular example of such a memory circuit is a random access memory (RAM) circuit.
B. Background of the Invention
An ongoing trend to reduce the size of the components in integrated memory circuits is leading to geometries that enable the operation of memory circuits using a lowered power level of about 1.8 volts. Power at this level is typically provided from a conventional unregulated external power source of about 3.0 volt by an internal low drop out (hereinafter "LDO") power supply regulator. Nonetheless, when such low voltage devices are inactivated or turned off, such as for backup or standby, the leakage currents exhibited are substantially large compared to those in devices configured using earlier versions of CMOS technology that typically operate from an unregulated external power source of about 3.0 volts with lower leakage current.
In modern CMOS processes, adequately low standby currents cannot be achieved simply by making all circuit nodes in such a circuit design static because of excessive leakage currents in such smaller geometry devices when placed in an "off" or inactive state. Previous solutions to this problem have concentrated on employing analog circuit techniques to reduce such leakage current. Examples of these techniques are the employment, for example, of a reverse substrate bias and the interposition of much less leaky high voltage transistors in each leakage path, such as employing thicker gate oxide, deeper device junctions and the employment of larger dimension devices or transistor elements. These solutions are complex and do not guarantee the desired results.
What is needed is a way to provide for memory circuit backup of their volatile memory states of the newer lower voltage operating CMOS circuits using an approach that provides for lower leakage during periods of circuit power inactivation or turn-off. The approach here utilizes digital circuit state retention in the absence of circuit power.

Backup for volatile state retention in the absence of primary circuit power


A child swing includes a foldable support stand, a child seat and a locking device. The support stand includes two front support legs, two rear support legs, and two first coupling housings interconnecting the front and rear support legs such that the rear support legs can pivot toward the front support legs. Two swing arms are connected respectively and pivotally to the first coupling housings. Two second coupling housings are connected respectively and fixedly to lower ends of the swing arms. Two U-shaped support rods are connected to the second coupling housings, and are pivotable toward each other. The locking device locks the child seat releaseably on the U-shaped support rods.

1. Field of the Invention
This invention relates to a child swing, and more particularly to a child swing that has a child seat, which can be removed from a child swing frame to serve as a car seat.
2. Description of the Related Art
Referring to FIG. 1, a convertible child swing 1 disclosed in U.S. Pat. No. 5,562,548 is shown to include a support stand 11, a swing frame 12, a base 13 coupled to the swing frame 12, and a child seat 14 that can also function as a car seat. The swing frame 12 is connected pivotally to the support stand 11. The child seat 14 is disposed removably on the base 13. The base 13 includes two latch assemblies 131, each of which has a latch arm 132. The latch arms 132 are inserted respectively into slots (not shown) in the child seat 14 so as to retain the child seat 14 on the base 13. The latch assemblies 131 can be pivoted outwardly to disengage the latch arms 132 from the slots in the child seat 14 so as to allow for removal of the child seat 14 from the base 13. Although the child seat 14 can be removed for use as the car seat, the child swing 1 is not foldable and therefore is inconvenient to transport and store. Furthermore, because the latch assemblies 131 are disposed on the base 13, it is difficult to connect/disconnect the child seat 14 to/from the base 13.
Referring to FIGS. 2 and 3, a child swing 2 disclosed in U.S. Patent Application Publication No. 2004/0198512 is shown to include a support frame 21, a hanger arm 22 connected pivotally to the support frame 21, and a seat 23. The support frame 21 includes two housings 211, two front legs 212 connected respectively and fixedly to the housings 211, and two rear support legs 213. The seat 23 has a seat bottom 231 and a seat back 232. When it is desired to fold the child swing 2, the rear support legs 213 and the seat back 232 are pivoted respectively toward the front legs 212 and the seat bottom 231, as shown in FIG. 4. Although the child swing 2 is foldable, the seat 23 cannot function as a car seat.

Child swing with a child seat removable to serve as a car seat


A golf ball includes a solid core, an intermediate layer, and a cover having dimples formed therein. The core has a Shore D hardness at the surface of 30-48, the intermediate layer has a Shore D hardness of 53-60, and the cover has a higher Shore D hardness of 55-65. In the cover, 370 to 450 dimples of at least two types having different diameters and/or depths are distributed so as to cover at least 63% of the ball surface. The index Dst of the overall dimple surface area is at least 4. The golf ball provides significantly improved flight distance and a good feel by virtue of a good balance in hardness and optimized dimple characteristics.

1. Field of the Invention
The present invention relates to a golf ball comprising a solid core, an intermediate layer, and a cover having a multiplicity of dimples formed on its surface. More particularly, the invention relates to a golf ball having an optimum balance in hardness between the core, the intermediate layer and the cover, and having suitable dimple characteristics, thus presenting both a good feel when hit with a club and improved flight performance regardless of the club head speed.
2. Prior Art
With the rise in the golfing population in recent years, the attributes that golfers look for in a golf ball have become more diverse and individualized. The desire is especially strong for golf balls having greater flight distance and a better feel. This has led to numerous investigations on ball construction, dimple parameters and so forth.
For instance, golf balls having a variety of constructions are available today on the market, but the majority of commercial golf balls are either two-piece solid golf balls made of a rubber-based core and a cover composed of ionomer resin or the like, or thread-wound golf balls composed of a thread-wound core obtained by winding rubber thread about a solid or liquid center, and a cover formed over the core.
Most golfers of ordinary skill use two-piece golf balls because of their excellent flight performance and durability. However, these balls have a very hard feel, in addition to which the rapid separation of the ball from the head of the club results in poor control. For this reason, many professional golfers and skilled amateurs prefer using thread-wound balls to two-piece solid balls. Yet, although thread-wound golf balls have a superior feel and control, their distance and durability fall short of those for two-piece balls.
Thus, two-piece golf balls and thread-wound golf balls today provide mutually opposing features, and so golfers select which type of ball to use based on their level of skill and personal preference.
This situation has prompted efforts to achieve the feel of a thread-wound ball in a solid golf ball, as a result of which a number of soft two-piece solid golf balls have been proposed. A soft core is used to obtain such soft two-piece balls, but making the core softer lowers the resilience of the golf ball and compromises flight performance and durability. As a result, not only do these balls lack the excellent flight performance and durability characteristic of ordinary two-piece solid golf balls, they are often in fact unfit for actual use.
Furthermore, these golf balls have generally been made to serve the needs of high head speed players, such as the professional golfer and the skilled amateur golfer. When they are used by low head speed players such as beginners, seniors and ladies, they are unsatisfactory both in terms of distance and feel.
Numerous studies have also been done on dimple characteristics, such as the dimple shape (e.g., depth and diameter), dimple configuration, and various dimple parameters, but there remains considerable room for improvement. The increasingly diverse and individualized desires of golfers have yet to be fully met.


A variable polarization independent optical power splitter is disclosed. An input light beam “A” is split into two output light beams “M” and “N” where the optical power ratio of the two output light beams “M” and “N” is adjusted to a desired ratio by controlling a variable polarization rotator, e.g. a liquid crystal unit. The polarization components “P” and “S” of the input light beam “A” are separated in a first polarization separator, then processed through the variable polarization rotator, and a second polarization separator. The polarization independence of the power split is thus achieved through the stratagem of processing the “P” and “S” polarized components of the input light beam “A” separately, resulting in four light beams “H”, “I”, “L” and “K”, which are appropriately combined in the polarization combiner to yield the output light beams “M” and “N” having the desired optical power ratio “R”.

Optical power splitters are required in many types of optical communications networks, such as long haul networks, metropolitan networks, and access networks, as well as in optical multiplexers and switches of such networks.
Fused fiber couplers can be used as optical power splitters, and have been known for many years as described, for example in U.S. Pat. Nos. 4,666,234, 5,064,267, 6,031,948, and 6,643,433, and have also been used within more complex optical systems, see e.g. U.S. Pat. No. 6,031,948.
In modern fiber optic telecommunications, much reliance is being placed on the state of polarization of light signals. Typically the polarization of the signal is used to help direct the signal along the fiber optic network. Network components or devices which function based upon the polarization of the light signal include fiber optic polarization tunable filters, depolarizers, binary polarization switch/modulators, polarization division multiplexers and many other polarization related fiber optic components. Many of these devices require fiber optic variable polarization beam splitters and/or combiners.
A variable polarization beam splitter in which the optical power split ratio is dependent on the polarization state of the light beam, and where the power split ratio can be controlled by means of liquid crystal cells, is described in U.S. Pat. No. 5,740,288.
However, for applications where the polarization state of the light beam is not known, and where a variable power split ratio is required, the beam splitters described in any of the aforementioned patents are not suitable: either the power split ratio is fixed, or the splitter relies on the polarization state of the light beam. One such application where both capabilities, that is a variable power split ratio as well as polarization independence, are required is in fiber CATV broadcast networks. In such system, the service company usually has to deploy a number of optical power amplifier to make sure that each end user will get enough optical power. With a variable power splitter, the optical power could be variable deploy among these end users. In this way the power margin could be shared and many amplifiers could be saved. Because the power may be deployed close to end user side, and at many different locations, the input light beam polarization state is difficult to know, so that the polarization independence device becomes a key issue for such applications.
Consequently, it is necessary to develop a variable optical power splitter providing polarization independence.

Variable polarization independent optical power splitter


In at least one embodiment, an apparatus for providing resources from a plurality of on-board device nodes to a hot-plugged device node in a computer is provided. The apparatus comprises a resource manager configured to receive a resource request over a bus system indicative of a set of desired resources from the hot-plugged device node. The resource manager is further configured to probe a parent device and at least one upper level device node positioned above the parent device node for the set of desired resources. The resource manager is further configured to provide the set of desired resources from the parent device node and one or more nodes of the at least one upper level device node over the bus system for transmission to the hot-plugged device node to enable the hot-plugged device node to operate in the intended manner.

1. Technical Field
One or more embodiments of the present invention generally relate to a system and method for allocating resources for a hot-plugged device or for re-balancing resources for existing devices to support resources needed for the hot-plugged device.
2. Background Art
For Peripheral Component Interconnect (PCI) or PCI express (or PCIe) devices that are operably coupled to a PCI bus in a computer system, such devices may not function if these devices are not allocated proper resources. The resources may include input/output (I/O) addresses, memory addresses, bus numbers, etc. When a computer is powered on, a basic input/output system (BIOS) may allocate the resources for all on-board (or existing) devices and reserve a limited amount of resources for newly inserted devices (or hot-plugged devices).
In some cases, if the device is hot-plugged when the computer system is running, the system probes resource requirements requested by the hot-plugged device so that the system can allocate the identified resources from the existing devices for the hot-plugged device. At times, there may not be enough resources available from the existing devices that can be allocated to the hot-plugged device. In such cases, the hot-plugged device may not operate in the manner desired by the user.
On a Solaris® based computer system, the BIOS (or Open Boot program (OBP)) probes or programs the devices already coupled to the system and assigns such devices resources when the system is powered on. After which, an operating system (OS) boot code reads a configuration space for the devices one by one and collects the information of assigned resources and then calculates the various available resources. The properties which describe the various resources for each device are setup based on the information that is collected and calculated. After the properties for each device are established, a resource manager generates a global linked list so that available resources can be identified by a newly plugged or hot-plugged device. However, when a device is hot-plugged into the system and there are not enough resources available for such a device at the device's immediate parent node, conventional resource managers may fail the resource allocation. Further, the properties for each existing device that has resources allocated or given to the hot-plugged device may not be updated to reflect that such resources are now assigned to the hot-plugged device.

System and method for device resource allocation and re-balance


A liquid crystal display device according to an embodiment of the present invention a includes: a gate line on a substrate; a data line crossing the gate line to define a pixel area; a thin film transistor connected to the gate line and the data line; a semiconductor pattern extended from the thin film transistor to overlap along the data line; a gate insulating pattern that overlaps along the semiconductor pattern to insulate the gate line and the data line; a pixel electrode in the pixel area spaced apart from the gate line and the data line and connected to the thin film transistor; and a passivation film formed in an area where the pixel electrode is not present to form a border with the pixel electrode.

1. Field of the Invention
The present invention relates to a thin film transistor substrate applied to a display device and a fabricating method thereof, and more particularly to a thin film transistor substrate that may be fabricated using a simplified process, and a fabricating method thereof.
2. Discussion of the Related Art
A liquid crystal display device controls light transmittance of a liquid crystal having dielectric anisotropy using an electric field, thereby displaying a picture. The liquid crystal display includes a liquid crystal display panel for displaying a picture through a liquid crystal cell matrix, and a drive circuit for driving the liquid crystal display panel.
Referring to FIG. 1, a liquid crystal display panel of the related art includes a color filter substrate 10 and a thin film transistor substrate 20 that are bonded together with a liquid crystal 24 therebetween.
The color filter substrate 10 includes a black matrix 4, a color filter 6 and a common electrode 8 that are sequentially formed on an upper glass substrate 2. The black matrix 4 is formed on the upper glass substrate 2 in a matrix shape. The black matrix 4 divides areas of the upper glass substrate 2 into a plurality of cell areas where the color filter 6 is to be formed, and prevents a light interference between adjacent cells and an external light reflection. The color filter 6 is formed to be divided into red R, green G, and blue B in the cell areas divided by the black matrix 4 to transmit red, green, and blue light, respectively. The common electrode 8 supplies a common voltage Vcom, that becomes a standard when driving the liquid crystal 24, to a transparent conductive layer that is formed on the entire surface of the color filter 6. In order to level the color filter 6, an overcoat layer (not shown) might be further formed between the color filter 6 and the common electrode 8.
The thin film transistor substrate 20 includes a pixel electrode 22 and a thin film transistor 18 formed in each cell area defined by the crossing of a gate line 14 and a data line 16 on a lower glass substrate 12. The thin film transistor 18 supplies a data signal from the data line 16 to the pixel electrode 22 in response to a gate signal from the gate line 12. The pixel electrode 22 formed of a transparent conductive layer supplies the data signal from the thin film transistor 18, thereby driving a liquid crystal 24.
The liquid crystal having dielectric anisotropy rotates in accordance with an electric field formed by a common voltage Vcom of a common electrode 8 and the data signal of the pixel electrode 22 to control a light transmittance, thereby realizing gray levels.
The liquid crystal display panel further includes a spacer (not shown) to maintain a fixed cell gap between the color filter substrate 10 and the thin film transistor substrate 20.
The color filter substrate 10 and thin film transistor substrate 20 of the liquid crystal display panel are formed by use of a plurality of mask processes. One mask process includes a plurality of processes such as thin film depositing (coating), cleaning, photolithography (hereinafter, referred to as "photo process"), etching, photo-resist stripping, inspecting, etc.
Specially, the thin film transistor substrate includes a semiconductor process and requires a plurality of mask processes, thus its manufacturing process is complicated thus increasing the manufacturing unit price of the liquid crystal display panel. Accordingly, the thin film transistor substrate has been developed to reduce the number of mask processes.

Liquid crystal display device and method for fabricating the same


An image forming device includes a table for storing link service function information that indicates a function necessary for providing the link service among functions installed in a computer for each link service, a computer status check portion for checking a function of the computer that is available at present, a provision appropriateness determination portion for determining whether or not each link service can be provided at present in accordance with the link service function information and the check result, and a screen display process portion for displaying identification information of the link service that is determined to be able to be provided.

1. Field of the Invention
The present invention relates to an image processor such as an MFP that is connected to other devices via a network and a method for controlling the image processor.
2. Description of the Prior Art
An image processor called a multifunction device or an MFP (Multi Function Peripherals) that is equipped with various functions including a copy, a scanner and a fax has become commonplace. Recently, in particular, a new type image processor is coming into widespread use that has more functions including a network printer and a document server by connecting to computers such as a personal computer via a network.
In addition, along with improvement of a CPU performance and a large capacity of storage devices available at a low cost, it has become easy to realize the entire or a part of control process for the image processing or each unit by software. Thus, extension of functions of the image processor has become easier than before, and a new function can be added easily after the image processor has appeared in the market.
Along with these developments, some methods for
Along with these developments, some methods for using the image processor more conveniently have been proposed.
Japanese unexamined patent publication No. 2003-67159 teaches a method in which plural copying machines are connected with a host computer via a network. The host computer stores data of places where the plural copying machines are placed. When the host computer receives a network search signal from a copying machine, the host computer sends the data of places where the plural copying machines are placed to the copying machine that issued the network search signal for so that the data are displayed. Thus, the user can find other copying machine easily when a copying machine that is regularly used by the user is out of order.
Japanese unexamined patent publication No. 2002-202946 teaches a method for managing a digital image processor that realizes an extended function by installing function program cards that respectively store function programs such as a copy function or a printer function. According to this method, when a power is supplied, the function program card and a hardware module embedded in the digital image processor are detected automatically so that an installation state of the functions is displayed. When a certain operation is performed, the display of the installation state is canceled and abnormal start up process is executed. Thus, the user can check that a desired function program and hardware are set before the normal starting up process.
In addition, another method is also proposed in which a function of the image processor and a function of the computer such as a personal computer are combined so as to provide a service to a user. For example, a service is proposed for storing an image file of a scanned image in a predetermined folder of the computer by linking a scan function of the image processor with a file management function of the computer. It is expected that various services in combination of functions of both devices will be proposed in the future.
However, according to the conventional methods described in the above-mentioned documents, a user cannot know whether the above-mentioned linking services are available or not at the present even though the user can see the state of the image processor.

Image processor and method for controlling the same

Konica Minolta Business Technologies, Inc.


The present invention discloses a metal oxide semiconductor (MOS) device and a method for operating an array structure comprising the same devices. The MOS device of the present invention comprises a device layer; an ion-implanted layer formed on the device layer and providing the source, the drain and the channel; and a gate structure formed on the ion-implanted layer. Via applying a bias voltage to the gate, the carrier density in the channel region is different from that in the source region or the drain region; thereby, the MOS device of the present invention can undertake programming, erasing and reading activities. The present invention can simplify the MOS device fabrication process, reduce the operating voltage, and promote the integration density of a 2-dimensional or 3-dimensional MOS device array.

1. Field of the Invention
The present invention relates to a semiconductor device, particularly to a MOS (Metal Oxide Semiconductor) device and a method for operating an array structure comprising the same devices.
2. Description of the Related Art
The prosperous development of communication and network is attributed to the fast advancing IC technology. The advance of IC technology is motivated by the persistent dimensional reduction, which decreases power consumption, increases switching speed, promotes integration density, and upgrades performance (such as the performance of data storage, logic operation, and signal processing). For a logic device, high operation speed relies on a sufficient saturation drain current and a low gate capacitance, and low power consumption relies on a further lower leakage current.
For a MOS (Metal Oxide Semiconductor) device, the size thereof is 3-dimensionally reduced. As shown in FIG. 1, a conventional MOS device comprises a substrate 10 having a source 102, a drain 104 and a channel 101 thereinside, a gate dielectric layer 12 formed over the substrate 10 and a gate layer 14 formed over the gate dielectric layer 12. For a MOS device, all structural factors influence the performance. Therefore, in addition to the length, width and height of the entire structure, the thickness of the gate dielectric layer 12, the junction depths of the source 102 and the drain 104, etc., also influence the performance of the MOS device. Via reducing the length and width of a MOS device, the integration density is promoted. Besides, decreasing the length of the channel 101 can increases the efficiency of driving power because the required driving current is inversely proportional to the length of the channel 101. The bottleneck of the MOS device fabrication process is primarily in photolithography. As the electric characteristics required by the source 102 and the drain 104 is different from that required by the channel 101, the conventional MOS device fabrication process is pretty complicated. The diffusion problem between the channel 101 and the source 102/drain 104 usually degrades the miniaturization capability. Due to the electric characteristics of the channel 101, the source 102 and the drain 104, a conventional MOS device has an inversion layer 141, which is below the gate and implements the reading activities of the device. However, an induced current, which inactivates the electric characteristics of the MOS device, is created when carriers drift across the inversion layer 141. The short-channel effect and the narrow-channel effect on a MOS device also need to be overcome. Modifying the sectional structural factors, such as decreasing the junction depth and the thickness of the gate dielectric layer 12, increasing the concentration of the implanted ions of the substrate 10, etc., is usually used to reduce the influence of the short-channel effect.
In the conventional technology, the abovementioned decreasing the junction depth and increasing the implanted-ion concentration of the substrate are realized via the means of ion implantation. To reach the specified depth, the ions should be accelerated to a sufficient speed. The concentration of the implanted ion can be precisely controlled via process parameters.
In the current MOS devices, different ions with different concentrations are respectively implanted into different regions of the substrate to prevent from the problems caused by the miniaturization of a MOS device. However, device miniaturization also makes the ion-implanted regions and the spacing between the ion-implanted regions become smaller. Thus, the structure of the overall MOS device becomes more complicated, which results in a higher process complexity and a lower device precision.
Refer to FIG. 2. A U.S. Pat. No. 6,704,253 disclosed a memory device, wherein a plurality of layers is formed over the substrate 20. The layers between two conduction layers 21 and 25 form a memory unit, including a semiconductor layer 22, a dielectric storage layer 26, a lightly-doped layer 23 and a heavily-doped layer 24. However, in addition to the complicated multi-layer structure, the layers must be further separately etched to obtain specified patterns. Therefore, the conventional memory device has a very complicated fabrication process and needs higher material and fabrication costs.
Accordingly, the present invention proposes a metal oxide semiconductor device and a method for operating the same to solve the abovementioned problems.

Metal oxide semiconductor device and method for operating an array structure comprising the same devices


A device to determine the contrast sensitivity of an individual's visual system by means of a series of tests in a measurement session, comprising a means for producing real time digital images, corresponding to modulated visual stimuli; and a display means for presenting said images to an individual's eye, wherein said stimuli may be modulated around an average stimulus in any direction of the color space and may be configured in their spatial and temporal characteristics for each measurement session. Said stimuli are usually chosen in the cardinal directions of the color space and respond to a sinusoidal grid pattern with spatial and temporal modulation, and with a two dimensional gaussian envelope.

Visual information travels from the retina to the primary visual cortex or striatum following two parallel paths referred to as magnocellular and parvocellular ways. These ways have their origin in the ganglionar cells called M and P, respectively. 75% of magnocellular way cells (referred to as MX) are linearly responsible whereas 25% of said cells (referred to as My) are nonlinear. All the parvocellular cells are linearly responsible.
There is much evidence proving that the detection of a purely chromatic contrast pattern, whether it be red-green or blue-yellow, is mediated by cells with spectral opponency belonging to the parvocellular way. Therefore, this way would be revealed as the physiological support for detection of chromatic contrasts in the whole space-time domain. Detection of an achromatic contrast pattern is much more controversial, although some studies point to the magnocellular way as the physiological support for detection of chromatic contrasts in the corner of low spatial frequencies and high temporal frequencies within the space-time domain.
A large variety of pathologies result from major injuries in one of these ways, and possibly in both. The origin of the pathology can be found in the retina, in the optic nerve, chiasma or any other site in the visual ways and even in visual cortex. Whatever the extent and the magnitude of the damage caused, it has been proven that contrast sensitivity on the damaged way will be altered. In any case, it is important to know which pathologies impair the Magno, which the Parvo, and which both, and in each case, which is the most suitable strategy for detecting a reduction in sensitivity on the damaged way or ways.
From the above it follows that when only the Magno is damaged by a pathology, a reduction of sensitivity in the visual system should be revealed by using an achromatic pattern of low spatial frequencies and high temporal frequencies. Nevertheless, an injury in the Parvo will result in a reduction of sensitivity in an wide set of spatial-temporal conditions with achromatic patterns and in any spatial-temporal conditions with modulated isoluminant patterns in any directions of the space color, specifically, the cardinal directions of the red-green or blue-yellow mechanisms. It has been not sufficiently proven which of the predictable reductions is primary in the progress of the pathology nor which is the one of highest magnitude. It also has not been sufficiently proven what deterioration is primary and more significant when both Magno and Parvo visual ways are injured by pathology. On the other hand, it is well known that the possibilities of making a good patient diagnosis are significantly enhanced if scanning of the whole retina and not only of the fovea is performed, that is, if what in the clinical language is referred to as campimetry is performed. In its more traditional form, campimetry consists of measuring, at each position of the field of sight, the threshold luminance so that a simple white circular spot can be detected on a background with a certain luminance, also white. However, in this type of campimetry, sensitivity losses are detected when a significant amount of ganglionar cells, for example in glaucoma, have already been damaged.
In recent years, notable efforts have been made to improve expectations in campimetric scanning. In the technique referred to as SWAP (Short Wavelength Automated Perimetry) a threshold is determined for detecting a blue circular spot on a yellow background. It has been shown that the detection of a spectral stimulus of a certain wavelength on a white background is mediated by ganglionar cells that are more sensitive for that wavelength. Blue spot campimetry improves the results that would be obtained traditionally with white on white campimetry. But a yellow background will increase the probability that the blue stimulus is detected by the blue-yellow channel. Although SWAP has substantially improved the features of the campimetries on a white background, is not still a technique free of problems. For example, it is well known that the response of a chromatic or achromatic mechanism is not isolated by an incremental paradigm (that is, a stimulus represented on a background), since it simultaneously entails a variation in the luminance and a variation in the color.
On the other hand, it has been proposed that the detection of a sinusoidal achromatic pattern in space and time with suitable frequencies may be capable of isolating the response of magnocellular way cells. These cells are affected, like the cells with blue-yellow opponency, by different pathologies, including glaucoma. If spatial frequency is particularly low and temporal frequency is particularly high, the pattern is perceived as if spatial frequency was twice as much as it actually is. It has been suggested that this phenomenon, referred to as frequency doubling, is attributable to My cells' nonlinear behavior. The technique related to frequency doubling observation is referred to as FDT (Frequency Doubling Technology).
US patent U.S. Pat. No. 5,065,767 discloses a method according to which a patient is presented a sinusoidal grid pattern which contrast is modulated to a frequency ranging from 10 to 50 Hz. The patient initially observes a spatial frequency doubling in this grid. Contrast resistance is gradually being reduced until a threshold value is reached at which the patient stops observing the frequency doubling. In patients with glaucoma this threshold can be as much as twice the contrast an observer considered as normal would need.
On the other hand, U.S. Pat. Nos. 6,068,377 and 6,227,668 provide methods that expand upon the above idea, in the sense that the frequency doubling would also occur with any pattern where the color palette consists of mixtures of complementary colors, particularly, blue and yellow mixtures. The pattern must be periodic in space and time and, as in the achromatic frequency doubling, spatial frequency must be low (not greater than 5 cycles/degree) and temporal frequency must be high (not smaller than 7 cycles/seconds). My cells are probably also responsible for this phenomenon, so a stimulus capable of producing a chromatic frequency doubling would a priori gather a number of potentially useful conditions for evaluating of problems that simultaneously involve deteriorations in Magno cells and Parvo cells with blue-yellow opponency. Nevertheless, it has not been proven at the moment that this type of campimetry is more effective than campimetry based upon achromatic frequency doubling.
Also with regard to frequency doubling, PCT application WO 95/29627 discloses a method that includes measuring, for different areas of a patient's field of sight, the minimum contrast with which this patient can still perceive an achromatic frequency doubling. This method detects early damage caused in the retina by glaucoma that affects only one part of the patient's field of sight.
In any case, a combination of two more tests may improve the early diagnosis of ocular pathologies, because some tests can detect before others the same sight defects caused by different pathologies. For example, sometimes an optic neuropathy may be identified earlier by means of stereophotographies than by detecting a sensitivity loss; or, on the contrary, a sensitivity loss is often detected in glaucoma first by SWAP or FDT tests. In any case, both SWAP and FDT, with some advantage for FDT, is revealed to be quite effective as early indicators of sensitivity loss in glaucoma.

Device and method to determine the contrast sensitivity of an individual's visual system


A crystal thin film is adopted as a specimen for measurement. A change in the contrast of crystal lattice fringes is measured under a condition that a diffracted wave and other wave are caused to interfere with each other. Thus, an information transfer limit of a transmission electron microscope can be measured quantitatively. Since the measurement is performed with a condition for interference restricted, the information transfer limit of the transmission electron microscope can be quantitatively assessed.

(1) Field of the Invention
The present invention relates to a technique for assessing the performance of a transmission electron microscope or a method for measuring an information transfer limit that is a major factor for determining a spatial resolution offered by an electron microscope, and a transmission electron microscope to which the measuring method is adapted.
(2) Description of the Related Art
In transmission electron microscopes, a resolution is the most important index of performance. The resolution falls into multiple different definitions such as a point resolution, a lattice resolution, and an information transfer limit that are conventionally used for different purposes.
Among the definitions, the point resolution refers to a resolution that provides a limit to which the structure of an observational entity such as an atomic structure in a specimen can be visualized correctly. When it says that the structure can be visualized correctly, it means that the changes in the phase and amplitude of an electron beam occurring when the electron beam passes through a specimen can be correctly reproduced on an image formation plane. If we observe an entity smaller than the point resolution, the phase of an electron beam cannot be correctly reproduced due mainly to spherical aberration caused by an objective lens. Consequently, the point resolution is the direct index of performance from the viewpoint of observing the structure of an observational entity.
In contrast, the information transfer limit refers to a limit of a resolution determined when the contrast of an electron beam (that is, a difference in the intensity=|amplitude|2 of an electron beam) is damped due to the incoherency of the electron beam caused by energy dispersion or angular dispersion.
In normal electron microscopes, the point resolution is larger than the information transfer limit. Therefore, when a specimen is observed using an electron beam that provides a spatial frequency equal to or larger than the information transfer limit, any contrast is manifested in a micrograph according to a degree of scattering (that is, information on a specimen) caused by the specimen. However, when a specimen is observed using an electron beam that provides a spatial frequency equal to or smaller than the point resolution, since the phase of the electron beam is not correctly reproduced, an image formed does not always correctly reflect the structure of an observational entity. For example, a structure that should appear in black may appear in white.
What explicitly indicates the relationship between an observational entity and an image is a phase contrast transfer function described in, for example, "Principles and Usage of High-resolution Electron Microscope" by Shigeo Horiuchi (1988, Kyoritsu Shuppan Co., Ltd., ISBN 4-320-07123-9, P. 146). FIG. 1A shows an example. Parameters employed are an accelerating voltage that is set to 200 kV, a degree of electron beam energy dispersion that is set to 2×10−6, a spherical aberration coefficient Cs that is set to 1.5 mm, a chromatic aberration coefficient Cc that is set to 2.5 mm, a focal spread Δ in the direction of the optical axis of an electron microscope caused by the chromatic aberration which is set to 8.3 nm, a degree of angular dispersion γ of an electron beam that is set to 1.0×10−5 rad, and a defocus length df that is set to +73.5 nm.
The axis of abscissas of the graph indicates a spatial frequency u equivalent to the size of an observational object, and the axis of ordinates indicates an amplitude with the amplitude of an incident electron beam regarded as 1. A curve 1a represents a phase contrast transfer function that reflects even an adverse effect of spherical aberration, and vibrates to signify that when the spatial frequency u is higher than about 4.0 nm−1, reproduction of a phase becomes incomplete. Namely, in this example, the spatial frequency u associated with a point resolution is 4.0 nm−1, and the point resolution ds is 0.25 nm.
On the other hand, as for contrast damping phenomena derived from energy dispersion of an electron beam and angular dispersion thereof respectively, as seen from a damping curve 2a and a damping curve 3a, the former contrast damping derived from energy dispersion is dominant. Namely, even when the imperfection in a phase expressed by the curve 1a is ignored, as the structure of an observational entity gets smaller, a contrast damps. On the contrast damping curve 2a expressing the contrast damping derived from energy dispersion and the contrast damping curve 3a expressing the contrast damping derived from angular dispersion, a point at which the amplitude assumes a certain defined value (for example, 1/e where e denotes the base of a natural logarithm) shall be defined to indicate the information transfer limit. In the example of the graph, the spatial frequency u associated with the information transfer limit is 4.1 nm−1, and a resolution of the information transfer limit dc is 0.24 nm. As mentioned above, in a conventional electron microscope, ds>dc is established. A substantial resolution offered by the electron microscope is represented by the point resolution.
In the late 1990's, a spherical aberration corrector employing a multipole electron lens was put to practical use. When a phase shift caused by spherical aberration can be corrected, the relationship between the values of a point resolution and an information transfer limit may sometimes be reversed to be ds<dc. In this case, the information transfer limit substantially determines a resolution to be offered by an electron microscope. FIG. 1B introduces an example of a phase contrast transfer function defined under the condition. A curve 1b represents a phase contrast transfer function that reflects even an adverse effect of a spherical aberration. Compared with FIG. 1A, the spherical aberration coefficient Cs is corrected to be 15×10−3 mm, and the defocus length df is set to +15.0 nm. Since the spherical aberration coefficient Cs is corrected, even when the spatial frequency u is so high as to exceed 5 nm−1, a phase can be correctly reproduced. Moreover, unlike the curve 1a shown in FIG. 1A, the curve 1b does not vibrate relative to even high spatial frequencies. The spatial frequency u associated with a point resolution is 5.6 nm−1, and the point resolution ds is equal to 0.18 nm.
On the other hand, since the spherical aberration alone is corrected, a damping curve 2b expressing contrast damping derived from energy dispersion does not change from the curve 2a shown in FIG. 1A. Consequently, an information transfer limit is the same as the one in the case in FIG. 1A where the spherical aberration is not corrected. The spatial frequency u associated with the information transfer limit is 4.1 nm−1, and the information transfer limit dc is 0.24 nm. Consequently, ds<dc is established. In this case, a resolution offered by an electron microscope is substantially restricted by the information transfer limit. Hereinafter, if the practical use of a transmission electron microscope with an aberration corrector further prevails, the information transfer limit will be presumably noted as an index of performance determining a resolution.
Methods for measuring an information transfer limit of a transmission electron microscope includes a method of observing an amorphous thin film, which is made of carbon, germanium, or tungsten, by setting an electron microscope at a high magnification, and producing a diffractgram (that is, a light-diffracted image of a micrograph or a Fourier-transformed image thereof). Since the amorphous thin film has a random structure, it is thought to include structures exhibiting various spatial frequencies (that is, having various sizes). Namely, When the amorphous thin film is observed using the electron microscope, a spatial frequency serving as a limit of the spatial frequencies exhibited by structures correctly reflected on a formed electron micrograph is inspected.
FIG. 2A shows an example of measurement based on a diffractgram produced by a field-emission transmission electron microscope to which an accelerating voltage of 1 MV is applied. In the diffractgram, a pattern of numerous rings appears. The ring pattern is associated with the fluctuation in an amplitude plotted as the vibration of the curve 1a representing the phase contrast transfer function in FIG. 1A. Namely, it can be said that an effective signal can be sensed while being discriminated from a background such as noise within a range of frequencies within which the rings are seen. Consequently, an information transfer limit can be estimated as a frequency limit to which the rings are discerned. In the example shown in FIG. 2A, the information transfer limit is about 0.1 nm.
The merit of the method lies in that an information transfer limit can be grasped two-dimensionally. Not only the information transfer limit but also an adverse effect such as aberrations caused by a lens, mechanical vibrations, or electromagnetic noise can be discerned. For example, when a lens causes astigmatism, a circular ring pattern in a diffractgram is shown to warp in the azimuth of the astigmatism. Moreover, if the mechanical vibrations occur, the pattern decays anisotropically to reflect the directivity of the vibrations.
As an extension of the method, there is a method of observing the same position in an amorphous thin film multiple times, checking a cross-correlation between images or the dependency on a spatial frequency, and estimating an information transfer limit. Specifically, a micrograph of the same position in an amorphous thin film is double exposed on the same film with the film slightly shifted, and a diffractgram (Fourier-transformed pattern) of images resulting from the double exposure is produced. If the double-exposure images have a correlation, Young fringes being spaced by a distance corresponding to a magnitude of parallel shift, by which the film is shifted for exposures, would appear in the diffractgram.
FIG. 2B shows an example of measurement (cited from "Breaking the spherical and chromatic aberration barrier in transmission electron miscroscopy" by B. Freitag, S. Kujawa, P. M. Mul, J. Ringnaldar, and P. C. Tiemeijer (Ultramicroscopy, Vol. 102, 2005, p. 209214). A pattern of parallel stripes running from right obliquely up to left obliquely down is called Young fringes. Double-exposure images have a correlation within a range of spatial frequencies within which the Young fringes are discerned. In other words, an effective signal is considered to be sensed within the range of spatial frequencies. Consequently, an information transfer limit can be estimated. In the example shown in FIG. 2B, the information transfer limit is estimated as a limit of the range of spatial frequencies within which the fringes are discerned, that is, approximately 0.07 nm.
The measuring method does not depend on a pattern (the rings in FIG. 2A) that derives from aberrations caused by an objective lens, but can assess a specimen on the basis of the correlation between two micrographs. The measuring method is therefore suitable for assessment of an information transfer limit of a transmission electron microscope that includes a spherical aberration corrector and has the spherical aberration, which is caused by an objective lens, corrected. In reality, FIG. 2B shows the pattern formed by an electron microscope which has aberrations corrected and to which an accelerating voltage of 300 kV is applied. A ring pattern stemming from spherical aberration caused by an objective lens and being seen in FIG. 2A does not appear because the aberration has been corrected. In other words, the method adopted in the case shown in FIG. 2A cannot measure an information transfer limit of the aberration-corrected electron microscope.
The two techniques are such that an amorphous thin film is observed using an electron microscope in order to determine an information transfer limit of the electron microscope. Chromatic aberration and spherical aberration caused by an objective lens are major factors that determine an information transfer limit according to the energy dispersion and angular dispersion of an electron beam. FIG. 3 schematically shows the relationship among a specimen, the objective lens, and an enlarged image. An electron beam 4 perpendicularly incident on a specimen surface of an amorphous thin film 5 along the optical axis 30 of an electron microscope becomes a transmitted wave g0, which has been transmitted by the amorphous thin film 5 that is a specimen to be observed, or scatters to become diffracted waves gk (where k denotes ±1, ±2, ±3, etc.). An image is formed on an (enlarged) image plane 8 by an objective lens 7.
In FIG. 1A and FIG. 1B, the damping curves 2a and 2b that represent contrast damping derived from energy dispersion of an electron beam and that are used to determine an information transfer limit are plotted to express a fading rate of the amplitude of an electron beam on the image formation plane 8 in relation to the spatial frequency U with the amplitude on the specimen surface of the amorphous thin film 5 as a reference. Once the amplitudes of the electron beam attained on the specimen surface of the amorphous thin film 5 and the image formation plane 8 respectively are known, a damping curve can be plotted and an information transfer limit can be determined. The amplitude on the image plane 8 can be measured because the electron beam can be observed as an enlarged image on the image plane. However, the value of the amplitude of the electron beam coming out of the specimen surface of the amorphous thin film 5 before passing through the objective lens is generally unknown.
As preconditions for use of the amorphous thin film 5, the structure of the amorphous thin film should be regarded as a random structure, and the distribution of spatial frequencies u should be regarded as being nearly continuous and uniform over a range of frequencies concerned (for example, from 1 nm−1 to 0.1 nm−1). The diffraction angle 2β of an electron beam on a specimen and the spatial frequency u have a relationship of 2β=λu where λ denotes the wavelength of the electron beam.
Consequently, as illustratively shown in FIG. 3, the diffracted waves gk (where k denotes ±1, ±2, ±3, etc.) work like conical homogeneous continuous light, which has the light source thereof placed on a specimen surface, over an angular range that defines an area where the spatial frequencies u are regarded as being uniform, and that ends with the objective lens 7. As long as the amplitude on the side of a specimen is regarded as being constant, the diffractgram shown in FIG. 2A expresses a phase contrast transfer function as it is.
The above approximation is merely established qualitatively at a low level. In reality, even when an amorphous thin film is employed, the image thereof has a specific distribution of spatial frequencies that is not uniform because of the radii of constituent atoms. Over an area where the spatial frequencies u exceed 0.1 nm−1, a scattering amplitude is known to rapidly fade because there is a limit to the scattering ability of constituent atoms to whatever of many atomic species the atoms belong. In other words, even when the diffractgram shown in FIG. 2A or the Young fringes shown in FIG. 2B are used to measure a contrast damping rate, the damping rate is not determined with an information transfer limit but with a variance in the quality of the amorphous thin film over a domain of frequencies equal to or larger than 0.1 nm−1 that should be noted in the future. There is therefore a high possibility that the information transfer limit dependent on an objective lens may be incorrectly assessed.
Further, the quality of the amorphous thin film 5 adopted as a specimen to be observed counts a lot inferably from the above description. For appropriate measurement, a homogeneous film having a film thickness of several tens of nanometers or less is needed. Moreover, an internal environment of an electron microscope such as contamination of a specimen largely affects measurement. For the appropriate measurement, preparation of a specimen and maintenance of an observational environment have to be achieved carefully.
As described in relation to the related art, an information transfer limit is expected to increase the significance as an index of performance of a transmission electron microscope that determines a resolution. In the past, a diffractram expressing an amorphous thin film is produced in order to estimate a phase contrast transfer function. However, as mentioned above, the result of measurement performed according to the conventional method largely depends on the quality of the amorphous thin film to be observed. Over a domain of resolutions that are equal to or smaller than 0.1 nm and that have come to be attainable in practice because an aberration correction technology has been put to practical use, the possibility that correct assessment cannot be achieved because there is a limit to homogeneity in the quality of the amorphous thin film gets higher.

Method for measuring information transfer limit in transmission electron microscope, and transmission electron microscope using the same


A metrology device determines the position of a machine component relative to a datum along three linear and three rotational axes. The metrology device has a pair of support structures connected by six legs that are each disposed at an angle with respect to the next adjacent leg. One of the support structures can be connected to the datum and the other can be connected to the machine component. A sensor cooperates with each leg to sense the actuation of that leg as the support structures move relative to one another. The combination of signals provided by the legs can be used to track movement of the machine component relative to the datum.

A variety of metrology devices are used with machines, such as machine tools or robotic machines, to discover errors in positioning of a moveable device, e.g., a tool that interacts with a workpiece. For example, in U.S. Pat. No. 5,489,168 a system is disclosed that is permanently attached to a six-axis machine tool to verify position of the tool being used, independently of the sensor system on the machine's actuator legs. This allows an operator or controller to determine errors in the positions indicated to the machine's control system, and to compensate for those errors Conventionally, the accuracy of a machine, such as a machine tool, has been verified by machining sample parts that are then mounted to a coordinate measuring machine (CMM) which probes select locations on the workpiece to determine deviation from the desired part parameters. If errors exist, the machine tool can be adjusted to compensate for those errors. Many other machines, such as robotic arms, also require verification of positional accuracy of the tool or other object to ensure precision and accuracy of operation. Some of these machines are able to move an object with six degrees of freedom as defined by the standard linear axes, x, y and z as well as the standard rotational axes a, b and c. Therefore, a six-axis metrology device is necessary to verify the accuracy of the machines movement along all six axes.
In some situations, a CMM having an arm constructed of pivotable and rotatable serial links is used to determine errors in positioning of, for instance a tool. Sensors are used to indicate the movement of each serial link relative to the next adjacent link, and the combination of signals can be used to track the movement along all six axes of one end of the arm relative to a datum at its opposite end. One problem with this type of system is that any errors in the CMM itself are additive due to the serial linking of moveable components. It would be advantageous to have the sensors connected in parallel rather than serially to provide an averaging of errors rather than an adding of errors in the device itself. Such a device could be used to verify the accuracy of the CMM arm or, in appropriate cases, to replace the CMM arm.
In many applications, it also would be advantageous to have a six-axis metrology device that could be connected to the machine to discover any errors in the positioning of the machine's moveable component, e.g., tool and then disconnected and removed prior to operation of the machine. In the case of a machine tool, for example, this would permit the accuracy of the machine and its control system to be tested prior to machining sample parts for verification of dimensions on a CMM. It would also obviate the need for constructing a permanent metrology device with each machine.
Furthermore, regardless of whether the metrology device is permanently or removably mounted to the machine being tested, telescopic sensor legs, such as those disclosed in the '168 patent, are sometimes vulnerable to static friction. The inherent nature of telescopic components requires that a certain amount of stick, sometimes known as stiction, must be overcome when movement first occurs. Some precise measurement operations, particularly in applications where the movement of the metrology device is repeatedly started and stopped, would benefit from reduced stiction.
The present invention addresses the foregoing drawbacks of existing metrology devices and methods of determining positional errors in machines.

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A display may have an array of pixels arranged in rows and columns. The pixels may be organic light-emitting diode pixels that each include an organic light-emitting diode and thin-film transistor circuitry for controlling the diode or may be other suitable display pixels. The pixels may form an active area of the display that displays images. Display driver circuitry may be provided in an inactive border area of the display. The display may include vertical gate lines. The display may also include data lines. The data lines may include vertical data line portions and orthogonal horizontal data line portions coupled to the vertical data line portions with vias. During operation, data from the display driver circuitry may be provided to rows of the pixels using the data lines while the vertical gate lines supply control signals to columns of the pixels.

This relates generally to electronic devices, and more particularly, to electronic devices with displays.
Electronic devices often include displays. For example, cellular telephones and portable computers often include displays for presenting information to a user.
Displays contain arrays of pixels for presenting images to users. Date lines that extend vertically through the display are associated with columns of the pixels. Control lines called gate lines that extend horizontally through the display are associated with rows of the pixels. The gate lines are used in controlling the loading of the data from the data lines into the pixels. Gate line driver circuitry along the left and right edges of the display is used in supplying gate line signals to the gate lines.
For aesthetic reasons and to save space in an electronic device, it may be desirable to reduce the size of the borders of a display and to create displays that are otherwise not constrained by the locations of display driver circuitry. The presence of driver circuitry along the edges of the display limits the minimum achievable border size for a display and restricts display layout. If care is not taken, a display will have larger inactive borders than desired.

Display having vertically driven gate and data paths


A venous access port assembly (10) having a housing (12), a septum (14), a discharge stem (16) at a distal end thereof for connection to a catheter (50), and an interior chamber (18). The housing includes a pair of recesses (28) along both sides thereof between the distal end and a proximal port end (24), where the recesses facilitate pushing the assembly by the practitioner into a subcutaneous pocket (104) of a patient (100) for implantation into the pocket.

Infusion ports for the infusion and/or withdrawal of fluids from a patient are well-known, secured to the proximal end of an implanted catheter. These ports are typically used for drug infusion or small amounts of blood withdrawal, where large flows of fluid are not required. The ports are assemblies of a needle-impenetrable housing with a discharge port in fluid communication with the catheter and the reservoir within the port housing, and provide a subcutaneous self-sealing septum that defines an access site for multiple needle sticks through the covering skin tissue of the patient, through the septum and into the reservoir, without the need to continuously search for new access sites. An example of such a port is disclosed in U.S. Patent Publication No. US 2007/0270770.
Such a venous access port assembly is implanted subcutaneously in the patient, and the catheter affixed thereto is inserted into the vasculature of the patient. For subcutaneous implanting of the assembly, a pocket is surgically created by the practitioner under the skin of the patient adjacent the incision into the blood vessel where the catheter enters the vessel. Some such ports are known to be provided with shovel-like protuberances on their proximal ends, opposite the discharge port, that assist in creating the subcutaneous pocket when urged into the incision into the skin in a direction away from the incision into the blood vessel through which the catheter enters the blood vessel.
It is desired to provide a venous access port that is easy to insert into the subcutaneous pocket.

Venous access port assembly with push surfaces