A method and apparatus for performing image reconstruction using data obtained by an N beam helical scan, the method including generating projection data arrays for each of the N rows in a CT detector, weighting the data arrays using a unique weighting function that including different weighting functions for a first detector row, a last detector row and the middle detector rows between the first and last detector rows thereby generating helical weighted arrays for each row, applying a half scan weight to each helical weighted array and using the half scan weighted arrays to generate a slice image.

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The present invention relates to multi-slice helical computerized tomography and more particularly to an algorithm, method and apparatus for using the same which increase the quality of resulting images by employing a new weighting algorithm.
In computerized tomography (CT) X-ray photon rays are directed through a region of interest (ROI within a patient toward a detector. Attenuated rays are detected by the detector, the amount of attenuation indicative of the make up (e.g. bone, flesh, air pocket, etc.) of the ROI through which the rays traversed. The attenuation data is then processed and back-projected according to a reconstruction algorithm to generate an image of the patient""s internal anatomy. Generally, the xe2x80x9cback projectionxe2x80x9d is performed in software but, as the name implies, is akin to physically projecting rays from many different angles within an image plane through the image plane, the values of rays passing through the same image voxels being combined in some manner to have a combined effect on the voxel in the resulting image. Hereinafter the data corresponding to rays which are back projected will be referred to as back projection rays.
During data acquisition, if a patient moves, artifacts can occur in the resulting image which often render images useless or difficult to use for diagnostics purposes. For this and other reasons, as in other imaging techniques, the CT industry is constantly trying to identify ways to reduce the duration of acquisition periods without reducing the quality of the data acquired.
In addition, because huge amounts of data are acquired during an acquisition period and the processing methods for image reconstruction from the gathered data are relatively complex, a huge number of calculations are required to process data and reconstruct an image. Because of the huge number of required calculations, the time required to process collected data and reconstruct an image is appreciable. For this reason the CT industry is also constantly searching for new processing methods and algorithms which can speed up the reconstruction process.
Various CT system features and procedures have been developed to increase data acquisition speed and to speed up the reconstruction process. Some of the more popular features and procedures including fan beam acquisition, simultaneous multiple slice acquisition, helical scanning and half-scanning. In fan beam acquisition the source is collimated into a thin fan beam which is directed at a detector on a side opposite a patient. In this manner, a complete fan beam projection data set is instantaneously generated for a beam angle defined by a central ray of the source fan beam. The source and detector are rotated about an image plane to collect data from all (e.g., typically 360 degrees) beam angles. Thereafter the collected data is used to reconstruct an image in the image plane. Thus, fan beam acquisition reduces acquisition period duration.
With respect to half-scanning, assuming a patient remains still during a data acquisition period, conjugate data acquisitions (i.e., data acquired along the same path from opposite directions) should be identical. In addition, using a fan beam, at least one ray can be directed through an image plane from every possible beam angle without having to perform a complete rotation about the patient.
For example, referring to FIG. 3, an annular gantry opening 70 is illustrated with a patient slice 42 disposed (support table not illustrated) therein and with respect to a Cartesian coordinate system where the Z-axis is into the Figure and defines a transport axis. A source 10 is illustrated in first, second, third and fourth positions as 90, 90xe2x80x2, 90xe2x80x3 and 90xe2x80x2xe2x80x3, respectively. When in the first position, source 10 generates a fan beam 40 which includes a central ray Rc and additional rays diverging therefrom along fan angles, the maximum fan angle being G. The beam angle xcex2 is defined as the angle formed by central ray Rc with respect to the vertical Y-axis.
When in the fourth position, source 10 generates a fan beam 40xe2x80x2xe2x80x3 which also includes a central ray (not illustrated) and rays diverging therefrom to form the fan beam. By rotating the source from the first to the fourth position in a clockwise direction data is collected at least once from every possible beam angle through slice 42 (i.e., the image plane). As known in the industry, data corresponding to every beam angle corresponding to a single image plane can be collected after a (xcfx80+2xcex93)2xcfx80 rotation about the patient. Because less than an entire rotation about the image plane is required to acquire the imaging data these acquisition methods and systems are generally referred to as partial-scan methods and systems and, more specifically, where data is collected during a minimal gantry rotation, the methods and systems are referred to as half-scan methods and systems. Thus, half-scan acquisition has been employed to reduce acquisition period duration in conjunction with single row detectors.
In addition, because relatively less data has to be processed in the case of half-scan imaging methods and systems to generate an image, half-scan methods and systems also have the advantage of potentially reducing data processing and reconstruction times.
As a result of the fan beam geometry of the x-ray source and the detector array, a half scan contains certain redundant data. This redundant data requires that the half scan data set be weighted with a xe2x80x9chalf scan weightingxe2x80x9d function so that the redundant data does not make a disproportionate contribution to the final image when incorporated with the non-redundant data. The weighting and reconstruction of images from a half scan data set are discussed in detail in xe2x80x9cOptimal Short Scan Convolution Reconstruction for Fanbeam CTxe2x80x9d, Dennis L. Parker, Medical Physics 9(2) March/April 1982.
While fan beams and half-scans have several advantages, often, during a diagnostics exercise a system user typically will not know the precise location within a patient of an object, cavity, etc. of interest to be imaged. For this reason, it is advantageous for a system user to be able to generate several cross sectional images in rapid succession by selecting different image/reconstruction planes. In these cases rapid data processing is extremely important to minimize delays between image generation so that a user does not lose her train of thought between image views.
Single slice detectors, fan beams and half-scans can be used to generate data in several different parallel image planes which, after data acquisition, can be used by a processor to generate an image anywhere between the image planes through interpolation/extrapolation procedures known in the art. For example, assume that during two data acquisition periods first and second data sets were acquired which correspond to first and second parallel acquisition planes, respectively, the planes separated by 0.25 inches. If a user selects an image plane for reconstructing an image which resides between the first and second acquisition planes, interpolation between data in the first and second sets can be used to estimate values of data corresponding to the selected image plane. For instance, assume that, among other rays, during the acquisition periods a first ray and a second ray were used to generate data in the first and second sets, respectively, and that the first and second rays were parallel (i.e. had the same beam and fan angles). In this case, by interpolating between the data acquired from the first and second rays generates an estimated value corresponding to a hypothetical back projection ray which is parallel to the first and second rays and which is within the image plane. By performing such interpolation to generate back projection rays for every beam and fan angle through the image plane a complete data set corresponding to the image plane is generated.
While such systems work, unfortunately, the acquisition time required to generate data corresponding to many image planes is excessive and inevitable patient movement often causes image artifacts.
One way to speed up data acquisition corresponding to several image planes is by employing a multi-row detector with a fan beam. In multi-row detector systems, a relatively thick fan beam is collimated and directed at a multi-row detector with a patient there between, each detector row in effect gathering data for a separate xe2x80x9cslicexe2x80x9d of the thick fan beam along the Z or translation axis perpendicular to a fan beam width.
After data acquisition an interface enables a system user to select an image plane from within the area corresponding to the collected data. The selected image plane is between the row centers of at least two adjacent detector rows. After image plane selection, a processor interpolates between data corresponding to adjacent rows to generate back projection rays corresponding to the selected image plane. When another image corresponding to a different image plane is desired, after selecting the plane, the processor again identifies an acquired data subset for interpolation, additional processing and back projection. Thus, multi-row detector systems further reduce data acquisition period duration where several image planes may be selected for reconstruction.
One limitation with multi-row detectors is that, during a single acquisition period, data can only be collected which corresponds to the detector thickness. To collect additional data corresponding to a greater patient volume, after one acquisition period corresponding to a first volume, the patient has to be moved along a translation axis until a second volume which is adjacent the first volume is between the source and detector. Thereafter a second acquisition process has to be performed. Similarly, to collect additional data corresponding to a third volume the patient has to be transported to another relative location with respect to the source and detector. Required translation without acquisition necessarily prolong the acquisition period and the additional acquisition time and aligning processes inevitably result in relative discomfort, additional patient movements and undesirable image artifacts.
Helical scanning systems have been developed so that data can be collected during a single acquisition period without halting patient translation during the acquisition period. In a helical scanning system, the source and detector array are mounted on opposing surfaces of an annular gantry and are rotated there around as a patient is transported at constant speed through the gantry. The X-ray beam sweeps a helical path through the patient, hence the nomenclature xe2x80x9chelical scanning systemxe2x80x9d. Data acquisition can be sped up by increasing operating pitch (i.e., table translation speed relative to gantry rotation rate).
Various combinations of the fan-beam, multi-slice, half-scan and helical scanning features have been combined to realize synergies and have been somewhat successful. For example, one system combines a multi-row fan beam detector and a fan beam source with a helical scanning procedure to rapidly acquire imaging data using a high pitch/high speed mode.
After high pitch helical data is acquired, the data is processed to generate back projection ray estimates and account for data nuances that are caused by the helical acquisition. The data processing typically includes application of a helical weighting function to the xe2x80x9cviewsxe2x80x9d (i.e., the data collected bat a specific gantry angle xcex2) collected by each detector row and then addition of the weighted views corresponding to identical gantry angles xcex2. The helical weighting functions are typically gantry angle xcex2 dependent. For instance, one exemplary helical weighting function is triangular having a value of one at a central gantry angle xcex2 that is aligned with a selected imaging plane and tapering off to zero at xcex2 angles on both sides of the central xcex2 angle corresponding to half the Z-axis distance between adjacent detector row center points. Thus, the helical weighting functions overlap. Rules are enforced such that the summation of the helical weighting function for all rows at a specific gantry angle xcex2 is one. Generally, after helical weights are applied, a weighted view from each side of a selected imaging plane are added to generate data corresponding to the imaging plane and a specific gantry angle xcex2.
Referring again to FIG. 3, in these high speed helical scanning systems, during acquisition data is acquired with source 10 at position 90, the source and detector are rotated (while data is collected) about gantry opening 70 as the patient 42 is transported there through. A processor collects data during transport and rotation from many different beam and fan angles. After source 10 rotates through a complete rotation and reaches position 90 again, additional data is gathered at that position. Because the patient 42 is transported along the Z axis during acquisition, while source 10 is at the same location 90 relative to opening 70 at the beginning and at the end of the rotation, the source and data collected are at a different Z location relative to patient 42. Hereinafter data collected for the same beam and fan angles but at different Z locations will be referred to as consecutively collected data.
To generate a slice image at a specific image plane, many interpolation techniques interpolate between consecutively collected data (i.e., data from source 10 at the same beam angle (e.g., position 90 in FIG. 3) and fan angle but at different Z (i.e., translation axis) locations). In other words, many interpolation techniques require data from more than a single source rotation to generate an image. In addition, because data from more than one rotation is required to interpolate, the data collection is relatively large and processing and reconstruction period durations are excessive. Moreover, where interpolation is between consecutively collected data, the resulting image has a xe2x80x9cthicknessxe2x80x9d characteristic which corresponds to a relatively thick patient volume which is unsuitable or at least not optimal for many diagnostic purposes.
Instead of using only interpolation to generate a slice image from a helical data set, some algorithms use data from a single half scan data set using interpolation at gantry angles where there is sufficient data to support interpolation and use extrapolation techniques at gantry angles where there is insufficient data to support interpolation. For instance, one such algorithm is described in U.S. Pat. No. 6,301,325 which issued on Oct. 9, 2001 and is entitled xe2x80x9cHalf-Scan Algorithm for use with a High Speed Multi-Row Fan Beam Helical Detectorxe2x80x9d and is commonly owned with the present invention.
Unfortunately there are several problems with extrapolation based algorithms. First, ideally only xe2x80x9cboundedxe2x80x9d data is used to generate an image where the term xe2x80x9cboundedxe2x80x9d is used to refer to data corresponding to views within a half scan gantry angle range xcex94xcex2. By limiting data used to generate an image to bounded data, generally, more accurate images that are true to the anatomical structures they purport to represent, are generated. Extrapolation is clearly an unbound process.
Second, extrapolation processes require additional views corresponding to the second and second to last detector rows (i.e., in an eight row detector the second and seventh detector rows) which complicate the computation process appreciably. To this end, extrapolation typically takes place at the ends of a half scan data range and requires helical weighting functions corresponding to the second row and the second to last row in each detector array to be extended and applied to additional views outside the normal weighting function range. For instance, in the case of an eight row detector, views collected by the seventh row are used for three purposes. First, some of the seventh row views are interpolated with sixth row views to generate interpolated views within the image plane for a sub-set of gantry angles. Second, some of the seventh row views are interpolated with eighth row views to generate interpolated views within the image plane for another subset of gantry angles. Third, additional seventh row views have to be extrapolated in conjunction with eighth row views to generate the extrapolated views required to generate an image. In addition to requiring additional calculations to apply weights to the additional row views, calculations are further complicated as special extended weighting functions have to be developed and applied by a processor.
For the reasons discussed above neither interpolation between data corresponding to more than one gantry rotation or extrapolation are optimal and therefore it would be advantageous to have an image generating algorithm that is computationally simple and accurate and that provides high quality images using a single half scan data set.
It has been recognized that different helical weighting functions can be applied to views corresponding to end detector rows in a multi-row CT detector and that a standard weighting function can be applied to each of the views corresponding to detector rows between the first and last rows (i.e., from the second to the second last row) to generate high quality images where the views used to generate the slice image correspond to a single half scan data acquisition. Importantly, using the inventive algorithm, interpolation between data from more than one gantry revolution is not necessary and extrapolation past bound data or row views can be avoided.
More specifically, where portions of helical weighting functions corresponding to adjacent detector rows overlap and therefore each helical function corresponding to an end detector row overlaps an adjacent helical function, the non-overlapping portions of each helical weighting function corresponding to each end detector row are set equal to one. After the helical weighting functions are applied to the row views, half scan weighting functions are then applied and relatively accurate images result.
These and other objects, advantages and aspects of the invention will become apparent from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention and reference is made therefore, to the claims herein for interpreting the scope of the invention.

GE Medical Systems Global Technologies Company LLC


A carburetor valve control system for stabilizing engine warm-up operating conditions by automatically controlling the degree of opening of a throttle valve so as to be larger than a normal degree of opening for idling, without carrying out a special operation of appropriately strengthening the spring force of a governor spring. The carburetor throttle valve control system includes a throttle lever and a governor system coupled to the throttle lever. A choke return spring is connected to a choke lever, the choke return spring urging the choke lever to a choke valve closing side. An automatic choke system is disposed so as to face the choke lever. A throttle valve closure restricting member is provided between the throttle lever and the choke lever. During engine warming-up, when the spring force of a governor spring is adjusted to zero or a minimum, the choke lever restricts closing of the throttle valve via the throttle lever by means of the spring force of the choke return spring.

The present invention relates to an improvement of a carburetor throttle valve control system comprising a throttle lever for opening and closing a throttle valve of a carburetor; and a governor system coupled to the throttle lever. The governor system includes a governor spring that exerts a spring force on the throttle lever in a direction to open the throttle valve, the spring force being adjusted via an output control member by an operator; and a governor that, when an engine is running, exerts an output on the throttle lever in a direction to close the throttle valve, and increases the output in response to an increase in the rotational speed of the engine.

Carburetor throttle valve control system


An image forming apparatus having: a transfer section which transfers a toner image onto an intermediate transfer body or a transfer material to form an image thereon; a selection section for selecting one mode among a plurality of modes including a first mode for forming the image by using a plurality of colors including a first color and a second mode for forming the image by using less number of colors including the first color than that of the colors in the first mode; and a control section for controlling the transfer section in order that a transfer rate of a toner image of the first color in the second mode is larger than that of a toner image of the first color in the first mode when toner images are transferred onto the intermediate transfer body or the transfer material by the transfer section.

1. Field of the Invention
The present invention relates to an image forming apparatus capable of changing a color mode to a subtractive color mode and vice versa for use.
2. Description of the Related Art
Earlier, an image forming apparatus capable of changing a color mode to a subtractive color mode and vice versa for use on the occasion of transferring toner images from a plurality of image bearing bodies to an endless belt-like intermediate transfer body or to a transfer material carried on the endless belt-like intermediate transfer body together with it has had the following two problems.
a) Peeling discharges are generated when the endless belt-like intermediate transfer body or the transfer material is separated from the image bearing bodies after transfers owing to a change of a resistance value of the endless belt-like intermediate transfer body or the transfer material, or owing to a rise of an electric potential of toner layers produced by superposing toner images colored in a plurality of colors.
b) Toners transferred onto the endless belt-like intermediate transfer body or the transfer material are changed in their charges and polarities at the time of the transfer of the next color or the color after the next, and are re-transferred onto the image bearing bodies.
As measures for solving the problems, the following means have been tried generally: decreasing a toner mass of deposit, decreasing a toner quantity of charging, decreasing a resistivity of the endless belt-like intermediate transfer body, selecting a transfer output in which the above-mentioned problems are difficult to occur, or the like. There was also a trail of combining the several measures for preventing the occurrences of the phenomena described above in the case of superposing a plurality of color toners, ordinarily two or more color toners.
In addition, there is also an image forming apparatus disclosed in, for example, Japanese Patent Application Publication (Unexamined) No. Tokukaihei-11-249371. The image forming apparatus is a color image forming apparatus using four color toners. When only a black toner is used in case of forming a monochrome image by this image forming apparatus, the other three color image bearing bodies are not made to contact with an endless belt-like intermediate transfer body or a transfer material carried together with it. In this case, only the transfer of the black toner should be considered. However, because transfer outputs in this case are set to be the same as those in case of transferring the four color toners, the output level of the black toner remains small. Consequently, such the image forming apparatus has a defect of resulting in an insufficiently transferred image in a monochrome mode.
Moreover, in the subtractive color mode using two color toners, normally, four image bearing bodies ordinarily contact with the endless belt-like intermediate transfer body, and in such a state, only two color toners are used. Consequently, transfers from the image bearing bodies of the residual two colors are unnecessary. However, in this case, the following problem is produced. That is, when a transferring image (a toner image) on which the above-mentioned two color toners have been transferred passes transfer positions of the image bearing bodies of the residual two color toners, the toners on the endless belt-like intermediate transfer bodies are re-transferred on the residual two color toner image bearing bodies.
For example, a technique disclosed in Japanese Patent Application Publication (Unexamined) No. Tokukai-2000-98758 copes with such problems by arranging a transfer section to each of the four image bearing bodies through the endless belt-like intermediate transfer body, and by setting transfer outputs of two transfer sections at two end positions on the uppermost stream and the lowermost stream to be larger than transfer outputs of two transfer sections at two positions in the central part. Moreover, because the transfer outputs of the transfer sections at the two end positions are set to be larger in a plural color mode than those in a monochrome mode, re-transferring becomes inevitable and good results are not necessarily obtained.

Konica Minolta Business Technologies, Inc.


A semiconductor wafer fabrication system that includes at least a track system and a scanner system compensates for deviations from nominal periodicity in the scanner system by dynamically introducing time delays when such deviations are detected. Preferably prior art static wait states are also introduced into the wafer recipe to reduce probability of resource conflicts. The resultant semiconductor wafer fabrication system can enjoy enhanced wafer throughput in that synchronization of wafer flow is maintained, despite such deviations.

Modern integrated circuits (ICs) are fabricated on semiconductor wafers that are mass produced in fabrication sites. The fabrications sites (or "fabs") employ various types of automatic equipment that must function to very exacting and carefully controlled operating parameters. FIG. 1 depicts some of the process steps or modules found in a generic fab system 10. System 10 may be thought of as a track system 20 that comprises a variety of production modules, and a scanner (or stepper) system 30. Track system 20 typically operates synchronously under control of a computer system 40 that, among other tasks, outputs a track system clock signal (TRACK CLOCK). By synchronously it is meant that wafers are moved in the track system 20 responsive to the track clock signal.
The wafers under production are made available for input to the scanner system 30 responsive to the track clock signal. However scanner system 30 receives the wafers and outputs scanner system-completed wafers responsive to its internal scanner system clock (SCANNER CLOCK). Understandably much attention is given in the prior art to trying to synchronize the track clock and the scanner clock to reduce dead-time in moving and processing wafers through the overall fabrication system. But to achieve good synchronization between the track clock and the scanner clock, the timing in the scanner system must exhibit a substantially consistent periodicity. But in practice, exposure procedures within the scanner system can exhibit,a timing deviation from nominal periodicity, which deviation or variability hampers clock synchronization.
Exemplary modules within track system 20 are shown in FIG. 1. At the upper left region of FIG. 1, a sequence of wafers are input to system 20. A chill plate module 50 typically is used to stabilize the wafer temperature by about 1° C. to room temperature before the wafers enter a spin coater 60 where a film of polymer photoresist is placed on the upper surface of the wafer. In some processes, at step 60 an anti-reflection coating may first be deposited upon the upper wafer surface and the wafer then baked (e.g., module or step 70) and then returned to the spin coater 60 for deposition of photo resist. As modern photolithography seeks to define smaller and smaller feature size using shorter wavelength light, ultraviolet reflectivity becomes a greater problem, and thus the use of anti-reflection layer(s).
Eventually the wafer is passed by a robotic unit 140 to a bake plate 70 where the film of photoresist is hardened and excess solvents are driven out of the wafer with heat. A subsequent chill plate process 80 cools the wafers to a stabilized room temperature. Upon receipt of a track clock signal issued by computer system 40, the wafer under process is then sent out of the thus-described portion of track system 20 and is available for input to the stepper/scanner system 30. Stepper/scanner system 30 will accept the wafer in question responsive to a signal from the scanner clock. Within system 30 various lithographic techniques may be carried out upon the wafer in question. At module or step 90, the wafer is subjected to a post-exposure bake (PEB), using a PEB bake plate, and then to a chill plate 100, that returns the wafer to a stabilized ambient room temperature. A developer module stage 110 typically follows, during which the latent lithographic image that was formed within the stepper/scanner module 30 is developed in the polymer film on the wafer upper surface. In a positive tone image, the portions of the photoresist exposed to light will become soluble and dissolve away in solution to expose desired regions of the wafer structure. A bake plate step 120 follows to dry and harden the wafer surface. An etcher module 130 then follows, and the thus-processed wafer is returned to a chill plate, e.g., module 50. Several of the steps or stages shown in FIG. 1 may be repeated for the same wafer dozens of time, depending upon the specifics of the processes involved (e.g., the "recipe". Typically devices shown generically as robotic arms 140 may be used to mechanically move wafers from one module to another.
In practice the rate at which track system 20 can send wafers for input to stepper/scanner system 30 may not coincide with the rate at which stepper/scanner system 30 is ready to receive ("R2R") new wafers. Similarly, the time when scanner system 30 is ready to send ("R2S") wafers back into track system 20 may not coincide with the moment at which track system 20 is ready to receive wafers for further processing. In some prior art systems 10, buffers such as 150 may be included to add time to processing of wafers within system 20. One or more buffers or buffer functions may be used in system 10 to absorb what would otherwise be disturbances to the time flow of wafers. A buffer may be a physical entity, for example a module used as a temporary storage site to hold excess wafers longer than needed for processing at that station, perhaps a dedicated buffer station, or a robotic arm temporarily used as a storage site for wafers.
By way of example, assume that responsive to timing of the track clock signal chill plate 80 is ready to send wafers into the stepper/scanner system 30 sooner than the stepper/scanner clock allows system 30 to be ready. When it is known that stepper/scanner system 30 is ready to receive wafers, the robotic arm 140 can load wafers into system 30, taking them if necessary from a buffer 150.
Understandably having to provide extra robotic arms and/or buffers to try to improve the output timing of track system 20 is not an optimum solution to the problem of enabling a better timing match between system 20 and system 30. There can be time conflicts within system 10 between modules competing for access to a given module, and it can be necessary to try to force time matching between wafers sent out of system 20, and wafers received into system 30, and then wafers exiting system 30 back into track system 20. But providing buffers 150 and/or additional robotic type mechanisms 140 to try to smooth out system flow requires additional cost and additional floor space within the fab, and will actually reduce wafer throughput.
One prior art solution to helping resolve resource conflicts within track system 20 is described in U.S. Pat. No. 6,418,356 (July 2002) to H. Oh, inventor herein. In the '356 patent, conflicts for transportation resources (e.g., robotic mechanism) are resolved by selectively adding "wait" time to modules that can tolerate such wait states without substantially degrading on-wafer production results associated with track system 20. Applicant incorporates herein by reference U.S. Pat. No. 6,418,356.
But even if track system resource conflicts can be resolved, deviations from nominal timing in the associated scanner system can degrade overall fabrication system performance. What is needed is a method of compensating for such scanner system timing deviations such that the timing match between the ready to send (R2S) state of the track system and the ready to receive (R2R) state of the stepper/scanner lithographic system is maintained.
The present invention provides such compensation for time deviations in a scanner system.

Method and system to compensate for scanner system timing variability in a semiconductor wafer fabrication system


Preferred techniques for transmitting on-demand data files include transmitting a first data stream in response to a first client request, and a new data stream in response to a subsequent second client request. The second client may snoop increasing amounts data from the first data stream, thereby decreasing the second client's reliance on the second data stream until the client has merged with the first data stream, at which time transmission of the second data stream will be discontinued. Alternatively, a patch data stream may be broadcast to the second client having a bandwidth less than that of the first data stream. The second client, in addition to receiving the second data stream real-time, will record data from a patch data stream until the second client has merged with the first data stream, at which time transmission of the second data stream and patch data stream will be discontinued.

The present invention relates to methods of transmitting program data files, or "streaming data", such as video or audio files, to multiple users at arbitrary delivery times within a delivery period and as selected by the users. In particular, the present invention provides a method of reducing the bandwidth or other costs associated with transmitting such data at different delivery times to multiple users.
Program data files, or "streaming data," is data that a user will process sequentially as it is received during a transmission. Examples of streaming data are video and audio programs, including movies, television shows, news clips, product advertisements, medical or recreational information, or education programs. This list of examples is not exhaustive. As implied by the examples, though, there is an application "playback rate" that imposes timeliness constraints on the delivery of data so that the application can make continuous progress through the data once it has reached a critical point (e.g., the display of a frame) on some initial segment of it. It should be recognized that the term "video program" as used below is meant to be inclusive of a variety of circumstances, including, for example, an independent entity such as a movie or television show, a piece of a more complex multimedia presentation, or a single layer of a program that has been encoded using base and enhancement layers.
"On-demand delivery" of streaming data is the delivery of streaming data beginning at a delivery time occurring substantially at the time of a user request for the data. For example in a video on-demand (VOD) system, a customer might be able to view a video program beginning at any time.
In order to reduce the costs of storage and distribution, "programs" of streaming data may be stored at and transmitted from a central server (which may consist of one or more machines) to a large number of users or clients via phone lines, cable, broadcast radio, satellite links or other media. For a popular program, many new requests will arrive at the central server during a delivery period.
On-demand delivery may be provided by making a separate transmission of data to each client when the client request arrives. This approach is simple and works with standard receiving device but has the disadvantage of requiring a large number of transmission channels, one for each new client. The transmission capacity of the server and the intervening communications medium (phone lines, cable, etc.) is termed "bandwidth" referring generally to the amount of data that can be transmitted in a given time interval. For this simple scheme of providing on-demand delivery of streaming data, the server bandwidth required to serve the clients increases linearly with the number of clients and thus does not scale well to large numbers of clients.

Method for efficient, on-demand data streaming


The invention pertains to a method for manufacturing a rotary anode assembly for an X-ray tube. According to the invention, a base element made of graphite is joined in a first step as a blank with excess dimensions to a shaft by material bonding. Then the further processing of the rotary anode assembly takes place by mechanical machining to nearly final-form dimensions and by application of the focal track coating, wherein the axis of rotation of the shaft is utilized as the reference for the performance of the mechanical machining.

1. Field of the Invention
The invention relates to a method of manufacture of a rotary anode assembly for an X-ray tube, and more particularly to a method wherein the base element consists of graphite or some other carbon based or ceramic material and the focal track is applied by a coating process.
2. Description of the Related Art
As a general rule, rotary anodes for X-ray tubes consist of a disk-shaped base element with an annular focal track coating of a high-melting-point metal or alloy, which generates the desired X-radiation by electron bombardment of the focal track coating.
The center area of the base element is connected to a cylindrical hollow metal shaft which is in turn connected to a rotor as the drive element of the rotary anode.
Rotary anode assemblies with a metal disk as the supporting base element usually have a central through-hole in the finish-machined rotary anode base element, into which the shaft is inserted and mechanically connected by a threaded fastening. In this way, a secure, sufficiently stable connection of these two mechanical components is achieved.
Rotary anodes must be accelerated in operation to a very high circumferential velocity within an extremely short period of time. For this reason, and particularly for large rotary anode dimensions, as required, in particular, for computer tomography, the heavy metal base elements are often replaced by those made of graphite or some other highly heat-resistant material based on carbon or ceramics with a lower specific gravity.
The advantage of the lower specific gravity of these materials as compared to metals with a comparable thermal capacity, however, is often accompanied by the disadvantage of lower strength, which can have a negative effect, in particular, regarding the connection between the rotary anode base element and the shaft.
Thus it is particularly disadvantageous that rotary anodes of low-density but weaker materials tend to burst when the base element is provided with a central through-hole for mechanical connection to the shaft. Such a connection of rotary anode and shaft is described, for instance, in U.S. Pat. No. 4,276,493. In order to eliminate this disadvantage, particularly when graphite is used as the base element, there have been suggestions to connect the shaft to the base element by soldering, without a through hole.
DE 24 25 082 A1, for instance, describes connecting rotary anode base elements to hollow shafts by welding and/or soldering. Among others, the connection of a base element made of graphite to the shaft is described. For the connection, the finish-machined base element with the focal track applied is inserted by a central cylindrical projection formed onto the bottom side into the tubular shaft and then the end of the projection is welded to the inside wall of the shaft. The formed projection, however, is not suitable to the material for strength reasons, even with large transition radii between base element and projection. Due to notch effects, material cracks can result, which can bring about a failure of the rotary anode in operation.
According to another example, in which the finish-coated and machined rotary anode base element with an end that is closed or expanded like a collar is butt-soldered to the tubular shaft, it is necessary to provide at least a centering aid in the form of a central depression in the rotary anode base element. Since the solder must be inserted between the contact surfaces in this type of soldering, a lateral displacement or tilting of the rotary anode base element with respect to the longitudinal axis of the shaft can often occur upon liquefaction of the solder during the soldering process, despite the centering aid. This leads to an eccentricity of the rotary anode in the radial or axial direction, which must be compensated for by mechanical machining after the soldering process. The compensation for an eccentricity in the axial direction is particularly costly for rotary anodes with a focal track applied by a coating process, since the coating must be applied to a corresponding excess dimension in order to permit a subsequent compensation of the eccentricity without the focal track becoming too thin at any one point. Since the material of the focal track is expensive, and the coating processes are inherently cost-intensive, any necessity to increase the layer thickness is a serious defect. Additionally, differing thicknesses of the focal track coating on the rotary anode cause a differing roughening behavior of the focal track, which is likewise undesired for usage.
For these reasons, it is desired to produce rotary anodes of highly heat-resistant materials with good strength such as, in particular, graphite, with a focal track coating applied by a coating process and without a central through-hole of the rotary anode base element.

Method for manufacturing a rotary anode assembly


The present invention concerns a tension member feeding device for feeding a tension member into a channel in a construction element. The feeding device comprises: tension member feeder and a resistance or speed detector. The feeding device is arranged to stop feeding of the tension member once the resistance or speed detector detects that the tension member meets a given resistance.

Tension members, such as prestressing tendons, are used to overcome concrete's natural weakness in tension. The method of prestressing concrete is used to produce beams, floors or bridges with a longer span than is practical with ordinary reinforced concrete. This method has also been extended to large civil work structures like tanks, dams and nuclear containments. Traditional reinforced concrete is based on the use of steel reinforcement bars (rebars) inside poured concrete. Prestressing tendons, generally composed of tensile cables made of high strength steel strands or rods, are used to provide a clamping force which produces a compressive stress on the concrete member to offset the tensile stress that the concrete member would otherwise experience due to an applied load.
The prestressing tendons are generally made up of a plurality of wires, bars or strands, the strands being further made up of several twisted metal wires. Known strands used in prestressing tendons are generally made up of metallic wires, for example steel wires. In some applications these wires are twisted together, and are coated with a protective filler and wrapped in a protective sheath of polymeric material, which may be extruded around the bundle of twisted-together wires.
Prestressed concrete can generally be accomplished in three ways: pre-tensioned concrete, and bonded or unbonded post-tensioned concrete.
Prestressed concrete by pretensioning is obtained by casting concrete around already tensioned tendons. This method produces a good bond between the concrete and tendon, with concrete protecting the tendon from corrosion and allowing for direct transfer of tension. The cured concrete can then adhere and bond to the tendons, and when the tension is released, the compressive stress is transferred to the concrete by bond. However, this method requires stout anchoring points between which the tendon is to be stretched, and the tendons are usually in a straight line. No ducts are needed for the tendons.
Prestressed concrete by applying the method of bonded post-tensioned concrete comprises applying compression after pouring concrete and the curing process (in situ). The concrete is cast around a plastic or steel duct (often curved). In follow the area where otherwise tension would occur in the concrete element. A set of tendons is fed through the duct, and the concrete is poured. The tendons may also be fed after pouring the concrete. Once the concrete has hardened, the tendons are tensioned by e.g. hydraulic jacks that react against the concrete member itself. When the tendons have stretched sufficiently, according to the design specifications, they are wedged in position so that the tension is maintained after the jacks are removed and the pressure is transferred to the concrete through the anchoring elements. Finally the duct is then filled with a hardening protective filler such as grout to protect the tendons from corrosion and to provide bond. This method is commonly used to create monolithic slabs for building construction and in the construction of various types of bridges.
Unbonded post-tensioned concrete differs from bonded post-tensioning by providing tendons with permanent freedom of movement relative to the concrete. To achieve this, according to one solution each individual tendon or strand is coated with a layer of grease (usually lithium-based) and covered by a plastic sheathing formed in an extrusion process. These coated and sheathed tendons are either placed directly inside the concrete or alternatively inside a duct which is finally filled with a hardening protective filler such as grout. Alternatively, non-coated and non-sheathed tendons (same as for bonded post-tensioned concrete above) may be installed inside the duct which then may be filled with a flexible protective filler such as grease or wax to prevent bond.
In post-tensioning methods, difficulties often arise when feeding tension members into a duct. The feeding operation is generally done by feeding devices specifically designed for this purpose. When tension members are individually fed into a duct, then they are generally pushed by the feeding device, also known as a strand pusher. The ducts can be very long and curved. Especially in these situations the tension member can get blocked inside the duct. This can be very problematic, especially if there is a protective sheathing around the tension member. In this case, the feeding device can damage the protective sheathing when trying to push the blocked tension member further into the duct. Tension members with a damaged sheathing are prone to corrosion before the filling of the duct with a protective filler is completed. Furthermore, the damaged sheathing may make it impossible to replace these tension members later. If the protective sheathing gets damaged, then often the whole tension member feeding operation has to be started again with a tension member having an undamaged protective sheathing.
It is the object of the present invention to overcome the problems identified above related to the feeding of tension members into ducts.


A method of simulating volumetric 3D display, includes: acquiring a display variable of a virtual display screen in a volumetric 3D display simulation space, the virtual display screen comprising a plurality of stereo pixels, the display variable comprising a voxel parameter of the plurality of stereo pixels, and the voxel parameter comprising a size in a first direction of the plurality of stereo pixels, a size in a second direction of the plurality of stereo pixels, and a size in a third direction of the plurality of stereo pixels; determining a display state parameter of a first stereo pixel of the plurality of stereo pixels for an object to be displayed according to the display variable; and simulating display of the object to be displayed according to the display state parameter. A computer-readable storage medium and a volumetric 3D display simulation apparatus are further provided.

In the field of 3D display, the volumetric three-dimensional (3D) display technology is an important research direction. The principle of the volumetric 3D display technology is to rotate a three-dimensional (2D) display panel around a fixed axis so as to obtain a 3D display space by sweeping. Corresponding images are displayed at different positions in the 3D display space, and the effect of true 3D display is achieved due to the visual persistence effect of the human eye.
In order to evaluate the effect of volumetric 3D display in advance, so as to obtain manufacturing parameters of volumetric 3D display devices, a simulation environment may be built based on Open Graphics Library (OpenGL). The computer simulates a 3D model to be displayed in volumetric 3D, performs voxelization on the 3D model, and displays data with an ideal stereo pixel point at a stereo pixel position.
However, it is difficult to obtain a display effect close to reality through the simulation of ideal stereo pixel points, which makes the degree of simulation and the efficiency of debugging parameters of the volumetric 3D display poor.

Method, device, apparatus and computer readable storage medium of simulating volumetric 3D display

Beijing BOE Optoelectronics Technology Co., Ltd.


Monoclonal antibodies to Prox1 of vertebrates (pfam05044.5; NM_002763.3) and two continuous cell lines for their production are disclosed. These antibodies are particularly useful in immunoassays to detect the presence of Prox1 protein in vertebrate tissues and cells.

In 1975, it was reported that individual, normal antibody-secreting cells could be fused with myeloma cells to produce continuous cell lines which stably secreted monoclonal antibodies (G. Kohler et al. (1975) "Continuous cultures of fused cells secreting antibody of predefined specificity", Nature 256: 495-497). Since then, numerous publications and patents have described the production and use of monoclonal antibodies to diverse antigens. See the following reviews for more details. (E. M. Yoo et al. (2002) "Myeloma expression systems", Journal of Immunological Methods 261: 1-20; P. N. Nelson et al. (2000) "Monoclonal Antibodies", Molecular Pathology 53: 111-117).
In monoclonal antibody production, each hybridoma cell synthesizes a homogeneous or monoclonal immunoglobulin population that represents one of many antibodies which are produced by the spleen of the immunized animals used to create the hybridoma cell. For example, U.S. Pat. No. 5,055,405 discloses the production of hybridoma cell lines which produce antibodies against the periodontal pathogen, Treponema denticola. And U.S. Pat. No. 6,818,215 discloses the production of hybridoma cell lines which produce antibodies against senescent cell-derived inhibitors of DNA synthesis. The present invention discloses antibodies specific to Prox1 from diverse vertebrate species.
Mouse Prox1 was first identified in 1993 as a vertebrate gene related to the Drosophila protein Prospero (G. Oliver, et al. (1993) "Prox1, a Prospero-related homeobox gene expressed during murine development", Mechanisms of Development 44: 3-16). Subsequently, Prox1 genes were found in diverse vertebrates including chicken, human and newts. Deletion of the Prox1 gene from the mouse genome showed that it was essential for development of the eye, liver, and lymphatic system (J. T. Wigle et al. (1999) "Prox1 function is crucial for mouse lens-fiber elongation", Nat. Genet. 21: 318-322). Rabbit polyclonal antibodies specific to human Prox1 were developed and used to detect this protein in the developing eye (M. K. Duncan et al. (2002) "Prox1 is differentially localized during lens development", Mech. Dev. 112: 195-198). Subsequently, Prox1 was shown to be an excellent marker to differentiate lymphatic vessels from blood vessels in vivo (Y. K. Hong et al. (2002) "Prox1 is a master control gene in the program specifying lymphatic endothelial cell fate", Dev. Dyn. 225: 351-357). Since many cancers metastasize to lymph nodes, some investigators have reported the presence of lymphatic vessels as predictive of the ability of a tumor to metastasize.
Prox1 is the vertebrate homolog of Prospero, a divergent homeodomain protein important for neuroblast fate determination and photoreceptor development in Drosophila (C. Q. Doe et al. (1991) "The Prospero gene specifies cell fates in the Drosophila central nervous system", Cell 65: 451-464; B. Hassan et al. (1997) "Prospero is a panneural transcription factor that modulates homeodomain protein activity", Proc. Natl. Acad. Sci. USA 94: 10991-10996; T. Cook et al. (2003) "Distinction between color photoreceptor cell fates is controlled by Prospero in Drosophila", Dev. Cell 4: 853-864). Human Prox1 is a 736 amino acid protein containing an N-terminal nuclear localization signal, three nuclear receptor boxes, a nuclear export signal and a highly conserved C-terminus containing the divergent homeodomain and the novel Prospero domain (T. R. Burglin (1994) "A Caehorhabditis elegans homologue defines a novel domain", Trends Biochem. Sci. 19: 70-71; S. I. Tomarev et al. (1998) "Characterization of the mouse Prox1 gene", Biochem. Biophys. Res. Commun. 248: 684-689; J. Qin et al. (2004) "Prospero-related homeobox (Prox1) is a corepressor of human liver receptor homolog-1 and suppresses the transcription of the cholesterol 7-alpha-hydroxylase gene", Mol. Endocrinol. 18: 2424-2439). Prox1 is highly expressed in lens fiber cells (M. K. Duncan et al. (2002) "Prox1 is differentially localized during lens development", Mech. Dev. 112: 195-198) and Prox1 null mice are defective in lens fiber cell elongation (J. T. Wigle et al. (1999) "Prox1 function is crucial for mouse lens-fibre elongation", Nat. Genet. 21: 318-322) and the differentiation of retinal horizontal cells (M. A. Dyer et al. (2003) "Prox1 function controls progenitor cell proliferation and horizontal cell genesis in the mammalian retina", Nat. Genet. 34: 53-58). In this context, Prox1 functions as a transcription factor and has been shown to transactivate both the chicken βB1- and mouse γF-crystallin promoters (J. Lengler et al. (2001) "Antagonistic action of six3 and prox1 at the gamma-crystallin promoter", Nucleic Acids Res. 29: 515-526; W. Cui et al. (2004) "Mafs, Prox1 and Pax6 can regulate chicken beta B1-crystallin gene expression", J. Biol. Chem. 279: 11088-11095).
While Prox1 is critical for eye development, the correct dosage of this protein is essential for embryogenesis since heterozygous Prox 1 null mice die shortly after birth on most genetic backgrounds while homozygous Prox1 nulls die at 14.5 dpc (J. T. Wigle et al. (1999) "Prox1 function is crucial for mouse lens-fibre elongation", Nat. Genet. 21: 318-322; J. T. Wigle et al. (1999) "Prox1 function is required for the development of the murine lymphatic system", Cell 98: 769-778). Analysis of these animals has shown that Prox1 is essential for the delamination of hepatocytes from the liver bud into the surrounding mesenchyme which is necessary for normal liver development (B. Sosa-Pineda et al. (2000) "Hepatocyte migration during liver development requires Prox1", Nat. Genet. 25: 254-255). Expression studies have shown Prox1 to be one of the earliest molecular markers of liver/pancreatic fated ventral foregut endoderm (Z. Burke et al. (2002) "Prox1 is an early specific marker for the developing liver and pancreas in the mammalian foregut endoderm", Mech. Dev. 118: 147-155). Prox1 expression is maintained in hepatoblasts and hepatocytes throughout development and is highly upregulated in transformed hepatoma cell lines (J. Dudas et al. (2004) "The homeobox transcription factor Prox1 is highly conserved in embryonic hepatoblasts and in adult and transformed hepatocytes, but is absent from bile duct epithelium", Anat. Embryol. (Berl) 208: 359-366). Prox1 interacts with liver receptor homolog-1 (LRH-1), a transcription factor essential for the expression of enzymes important for bile acid synthesis, repressing LRH-1 transcriptional activity by impairing its binding to DNA (J. Qin et al. (2004) "Prospero-related homeobox (Prox1) is a corepressor of human liver receptor homolog-1 and suppresses the transcription of the cholesterol 7-alpha-hydroxylase gene", Mol. Endocrinol. 18: 2424-2439).
Prox 1 is also a key player in the formation of the lymphatic system (Y. K. Hong et al. (2002) "Prox1 is a master control gene in the program specifying lymphatic endothelial cell fate", Dev. Dyn. 225: 351-357). Expression of Prox1 in a subpopulation of venous endothelial cells is one of the first indications that lymphangiogenesis has been initiated and cells biased to a lymphatic phenotype (J. T. Wigle et al. (2002) "An essential role for Prox1 in the induction of the lymphatic endothelial cell phenotype", Embo. J 21: 1505-1513). Prox1 null mice do not develop lymphatics due to arrested endothelial budding from the primary vascular network (J. T. Wigle et al. (1999) "Prox1 function is required for the development of the murine lymphatic system", Cell 98: 769-778). Overexpression of Prox1 can reprogram blood vascular endothelial cells into lymphatic endothelial cells confirming the central role of Prox1 in lymphatic specification (T. V. Petrova et al. (2002) "Lymphatic endothelial reprogramming of vascular endothelial cells by the Prox-1 homeobox transcription factor", Embo J. 21: 4593-4599). Immunostaining of lymphatic tissues from healthy human adults and lymphedema patients with Prox1 polyclonal antibodies showed that Prox1 is a reliable and highly specific marker for lymphatic endothelial cells in normal and pathologic human tissues (J. Wilting et al. (2002) "The transcription factor Prox1 is a marker for lymphatic endothelial cells in normal and diseased human tissues", Faseb J. 16: 1271-1273; J. S. Reis-Filho et al. (2003) "Lymphangiogenesis in tumors: what do we know?", Microsc. Res. Tech. 60: 171-180; I. Van der Auwera et al. (2004) "Increased angiogenesis and lymphangiogenesis in inflammatory versus noninflammatory breast cancer by real-time reverse transcriptase-PCR gene expression quantification", Clin. Cancer Res. 10: 7965-7971; M. A. Al-Rawi et al. (2005) "Lymphangiogenesis and its role in cancer", Histol. Histopathol. 20: 283-298). However, the routine use of Prox1 staining in the clinic to identify lymphatics in biopsy specimens is impeded by the lack of highly standardized and reproducible anti-Prox1 monoclonal antibodies. In accordance with the invention, anti-Prox1 monoclonal antibodies are provided that can be used for Prox1 immunodetection in diverse vertebrates from humans to reptiles.

Hybridoma cell lines and monoclonal antibodies recognizing Prox1


A medical image processing apparatus including: a diagnosis aid information generation section to generate diagnosis aid information by analyzing a medical image; a diagnosis aid information generation selection section to select whether to generate the diagnosis aid information, based on accessory information of the medical image; and an image output section to output the medical image and/or the generated diagnosis aid information to an image output apparatus.

1. Field of the Invention
The present invention relates to a medical image processing apparatus which is capable of generating and outputting the corresponding diagnosis aid information by analyzing a medical image.
2. Description of Related Art
A conventional system for aiding a doctor to diagnose is already known, wherein the diagnosis aid information such as a detection result of the abnormal shadow candidates is added to the medical image which is used for screening, and outputted to a CRT monitor, an LED, or the like. For example, a technique is disclosed which switches the image output destination corresponding to the detection result of the abnormal shadow candidates (e.g. refer to JP-Tokukai-2000-342559).
The medical image and diagnosis aid information vary in output format and image output apparatus (e.g. a monitor, an image recording apparatus) with the individual diagnosis purpose as well as the image usage. However, the conventional approach suffers from being too complicated in that it requires a user, according to the individual diagnosis purpose as well as the image usage, to specify the output destination of the medical image and the diagnosis aid information, and the output format.


A platinum/Rhodium resistance thermal probe is used as an active device which acts both as a highly localized heat source and as a detector to perform localized differential calorimetry, by thermally inducing and detecting events such as glass transitions, meltings, recystallizations and thermal decomposition within volumes of material estimated at a few xcexcm3. Furthermore, the probe is used to image variations in thermal conductivity and diffusivity, to perform depth profiling and sub-surface imaging. The maximum depth of the sample that is imaged is controlled by generating and detecting evanescent temperature waves in the sample.

1. Field of the Invention
The present invention relates to determining thermal properties of materials using a miniaturized resistive thermal probe. More particularly, the present invention relates to performing localized thermal analysis experiments whereby calorimetric information is obtained from a volume of materials on the order of a few cubic microns, whereas in conventional bulk calorimetry data is obtained from volumes of material on the order of a few cubic millimeters. The present invention also relates to modulating the temperature of a thermal probe to generate evanescent thermal waves in a material to thereby generate sub-surface images.
2. Background of the Invention
Several methods for the non-destructive characterization of solids make use of thermal excitation. Any local disruption of the structure that results in a change in density, specific heat, or thermal conductivity may be detected by some type of thermal probexe2x80x94often with higher sensitivity than by the use of optical, X-ray, or electron-microscope techniques. Many of these techniques use an intensity-modulated energy source to excite a sample. That is, the intensity of the energy source used to excite the sample is made to vary with time. Induced scattered evanescent thermal waves are then detected by, for example, monitoring the surface temperature of the sample. When a scanning mechanism is also incorporated, it is then possible to achieve spatial thermal mapping. Subsurface imaging can be performed within the depth of penetration of the thermal wave.
Most conventional methods of thermal imaging employ an energy beam that emerges from a small source and spreads out according to the rules of diffraction. The extent of this spreading is normally governed by the wavelength associated with the energy flux. However, if the sample is within the xe2x80x9cnear-fieldxe2x80x9d region, i.e., significantly less than one wavelength away from the source, then a greatly reduced beam diameter can be achieved. In this case, the beam diameter is not much larger than the size of the source itself.
This principle is applied in Scanning Probe Microscopy whereby a sharp probe is brought in close proximity to the surface of a sample. Some probe/sample interaction takes place. This interaction is monitored as the probe is scanned over the surface. An image contrast is then computer-generated. The image contrast represents variations of some property (e.g., physical, mechanical, chemical) of the sample across the scanned area. One such scanning probe microscope is the Atomic Force Microscope (AFM). In conventional AFM, the height of a probe above the surface being scanned is controlled by a feedback system, that keeps the force between the probe and the surface of the sample constant. The probe height is monitored, and provides the data that is used to create image contrast which represents the topography of the scanned area.
Near-field thermal imaging is described by C. C. Williams and H. K. Wickramasinghe in Photoacoustic and Photothermal Phenomena, P. Hess and J. Peltzl (eds.), p. 364 (1988). In their device, the probe is a specially made coaxial tip that forms a fine thermocouple junction. This probe provides a spatial resolution on the order of tens of millimeters. The sample is either heated using a laser or the probe, or the sample is heated electrically. The feedback system maintains the probe temperature constant (instead of maintaining the force constant), by varying the probe height as necessary.
In xe2x80x9cThermal Imaging Using the Atomic Force Microscope,xe2x80x9d Appl. Phys. Lett., vol. 62, pp. 2501-3 (1993), Majumdar, et al. describe a technique for thermal imaging that uses a simpler design of thermocouple tip, than that disclosed by Williams and Wickramasinghe. Majundar, et al. implemented standard atomic force microscopy feedback to maintain tip/sample contact. R. B. Dinwiddie, R. J. Pylkki and P. E. West xe2x80x9cThermal Conductivity Contrast Imaging with a Scanning Thermal Microscope,xe2x80x9d Thermal Conductivity 22, T. W. Tong (ed.) (1994), describe the use of a probe in the form of a tiny platinum resistance thermometer. U.S. Pat. No. 5,441,343 to Pylkki et al., which is incorporated herein by reference, discloses the thermal sensing probe for use with a scanning probe microscope, in which the contact force of the probe is maintained at a constant level as the probe is scanned across the surface of the sample.
In those studies, the samples were generally probed at a constant (ac or dc) amplitude of either surface temperature or heat flow. Thus changes in the thermal properties of materials, such as heat capacity or thermal conductivity, were not investigated. This is because the temperature of the sample was not raised by a sufficient amount for a change in the sample""s thermal properties to be detected.
Bulk thermal analysis techniques have been developed to study such changes in the thermal properties of materials. Modulated temperature differential scanning microscopy (MDSC) and spatially-resolved modulated differential scanning calorimetry (SR-MDSC) are described in U.S. Pat. No. 5,224,775 (""775 patent) and U.S. Pat. No. 5,248,199, respectively, which are both incorporated herein by reference. A conventional heat flux differential scanning calorimeter (DSC) measures the heat flow into and out of a sample with respect to a reference. Both sample and reference are usually subjected to a linear temperature/time ramp. In one implementation of MDSC, a sinusoidal modulation is superimposed on the underlying heating ramp to generate a corresponding sinusoidal response in the heat flow signal. This results in two measurements of heat capacity, an underlying linear long-period measurement due to the underlying heating ramp and a higher-frequency cyclic measurement due to the superimposed sinusoidal modulation. For many systems the cyclic measurement xe2x80x9cseesxe2x80x9d only the reversible heat capacity associated with molecular vibrations, e.g., glass transitions, whereas the underlying measurement also sees endotherms and exotherms associated with kinetically-controlled events such as recrystallization cure reactions or the loss of volatile materials.
The present invention is a new analytical technique which makes calorimetric measurements on a localized scale. Data obtained from the measurement can be used to generate contrast in our image of the thermal properties of the sample on a localized scale. In addition, by subjecting the sample to an oscillating program, images of the sample at a depth below the surface can be made. The depth corresponds to the frequency of the applied oscillatory temperature.
The present invention applies modulated temperature differential scanning calorimetry, as described in U.S. Pat. No. 5,224,755 to Reading, et al. (""775 patent), which has been conventionally used to perform bulk thermal analysis experiments of a sample material, to microscopic thermal analysis of a sample material using two highly miniaturized resistive probes, developed by the Topometrix Corporation (U.S. Pat. No. 5,441,343 to Pylkki et al. (""343 patent)), in a differential configuration. A sample probe attached to a Scanning Probe Microscope is positioned at a desired location on the surface within the field of view. Localized calorimetry is then performed at that position by inducing and detecting localized phase transitions. This is achieved by ramping the temperature of the probe by passing an electrical current through the probe. A small temperature oscillation is superimposed to that temperature ramp by adding a modulated component to current the probe current. By scanning over the surface of the sample, contrast can be developed corresponding to particular locations on the sample to create an image of the thermal properties of the sample at particular locations.
A second embodiment of the present invention allows for sub-surface imaging thermal microscopy to be performed by modulating the temperature of the probe. This is done by passing a modulated current through it, thus generating thermal waves within the sample. The depth of penetration of these waves is frequency dependent, such that the thermal properties of a sample can be probed as a function of depth below the surface.
The probe, developed by the Topometrix Corporation, is an elongated loop of Wollaston wire, shaped in the form of a canteliver whose end forms the resistive element. The resistance of that element varies with temperature. Conversely, its temperature can be set by passing a current of appropriate value through it. A mirror is attached across the loop allowing for the contact force of the element on the sample to be held constant, as in conventional atomic force microscopy, while the probe is scanned across the surface of the sample.
In the two embodiments of the present invention, the probe is used as a highly localized heat source by passing a current through it. The temperature of the probe is either constant, or is variable as a function of time. As the probe is brought close to the surface of a sample, heat will flow from the probe to the sample. The amount of heat flowing will vary according to various properties of the sample at the location under the probe. This varying heat flow causes the temperature of the resistive element to change, thereby changing its resistance. A feedback circuit is preferably used to sense the change in the probe resistance (and therefore its temperature) and increase the amount of current flowing through the probe to bring it back to its original resistance value (and therefore to its set temperature). A differential signal is then monitored, either directly or through a lock-in amplifier. The differential signal is used to either (1) produce localized analysis plots of amplitude and phase data versus temperature that provide calorimetric information at a specific position on the sample, or (2) construct an image whose contrasts represent variations in thermal conductivity and/or diffusivity across a scanned area. In the second case, the time-varying current through the resistive elements generates thermal waves in the sample. The modulation frequency of the time-varying current is functionally related to the depth below the surface of the sample at which an image of the sample is desired. A sub-surface image is thus generated. The depth of material below the sample surface that is contributing to the image can be controlled by suitably choosing the temperature modulation frequency. As described in Almond, et al., xe2x80x9cPhotothermal Science and Techniques,xe2x80x9d page 15, Chapman and Hall (London 1996), which is hereby incorporated by reference in its entirety, the penetration depth is proportional to the square root of the thermal diffusivity of the sample divided by the frequency of the applied temperature wave.
A first object of the present invention is to provide localized differential thermal analysis at the micron level, such that events such as glass transitions and meltings can be induced in a highly spatially localized manner and identified.
A second object of the present invention is to use scanning thermal microscopy to obtain sub-surface images of solids, in which the image contrast is due to variations in thermal diffusivity within a given controllable depth.
Another object of the present invention is to use a highly miniaturized resistive thermal probe as a highly localized source of heat, such that it can be used to produce highly localized phase transitions at the surface of samples.
Another object of the invention is to use modulated differential scanning calorimetric signals to produce a high-frequency temperature modulation in a probe used for sensing the thermal properties of materials at different depths below the surface.
Another object of the present invention is to provide an apparatus which can, for a sample containing different regions subject to either reversible or irreversible changes with temperature, produce thermal images showing contrast based upon the reversing and nonreversing nature of the heat flow, respectively.
These and other objects of the present invention are described in greater detail in the detailed description of the invention, the appended drawings and the attached claims.

Method and apparatus for performing localized thermal analysis and sub-surface imaging by scanning thermal microscopy


A handwriting device includes a supporting device using two supporting arms. Each of the supporting arms is an elongated plate, includes a sliding end and an opposite pivoting end, and further includes an engaging surface. The sliding ends of the supporting arms are slidably engaged in two respective sliding channels defined in a supporting base. A cutout is defined in the engaging surface at the pivoting ends. A through hole is defined at each of the pivoting ends where the cutout is formed. The through holes of the supporting arms are aligned with each other. The supporting arms are rotatably connected with each other via a threaded bolt passing through the through holes of the supporting arms. As such, the height of a camera module supported by the supporting arms can be adjusted.

1. Technical Field
The present disclosure relates to supports and, particularly, to a support device for a camera of a handwriting device and the handwriting device. The support device and the camera can be folded when the camera is not in use.
2. Description of Related Art
Currently, a handwriting device using a camera to acquire writing of a pen (i.e., a stylus) on a board has been proposed. In the handwriting device, the camera is supported above the board, typically by a holding arm perpendicularly extending upwards from a side of the board, and aimed at the board to capture images of the entire board. This holding arm and the camera add substantially to the size of the handwriting device, making the handwriting device cumbersome when the handwriting device is not in use and difficult to be packed up and/or transported.
Therefore, it is desirable to provide a support device for a camera of a handwriting device and the handwriting device, which can overcome the above-mentioned problems.

Foldable support device for camera of handwriting device and handwriting device having same


When misses occur in an instruction cache, prefetching techniques are used that minimize miss rates, memory access bandwidth, and power use. One of the prefetching techniques operates when a miss occurs. A notification that a fetch address missed in an instruction cache is received. The fetch address that caused the miss is analyzed to determine an attribute of the fetch address and based on the attribute a line of instructions is prefetched. The attribute may indicate that the fetch address is a target address of a non-sequential operation. Another attribute may indicate that the fetch address is a target address of a non-sequential operation and the target address is more than X % into a cache line. A further attribute may indicate that the fetch address is an even address in the instruction cache. Such attributes may be combined to determine whether to prefetch.

Many portable products, such as cell phones, laptop computers, personal data assistants (PDAs) or the like, utilize a processor executing programs, such as, communication and multimedia programs. The processing system for such products includes a processor and memory complex for storing instructions and data. Large capacity main memory commonly has slow access times as compared to the processor cycle time. As a consequence, the memory complex is conventionally organized in a hierarchy based on capacity and performance of cache memories, with the highest performance and lowest capacity cache located closest to the processor. For example, a level 1 instruction cache and a level 1 data cache would generally be directly attached to the processor. While a level 2 unified cache is connected to the level 1 (L1) instruction and data caches. Further, a system memory is connected to the level 2 (L2) unified cache. The level 1 instruction cache commonly operates at the processor speed and the level 2 unified cache operates slower than the level 1 cache, but has a faster access time than that of the system memory. Alternative memory organizations abound, for example, memory hierarchies having a level 3 cache in addition to an L1 and an L2 cache. Another memory organization may use only a level 1 cache and a system memory.
One of the principles behind why a memory hierarchy for instruction caches can be used is that instructions tend to be accessed from sequential locations in memory. By having caches hold the most recently used sections of code, processors may execute at a higher performance level. Since programs also contain branch, call, and return type instructions, and support other non sequential operations such as interrupts, the principle of sequential locality may be maintained only for relatively short sections of code. Due to such non-sequential operations, an instruction fetch to an instruction cache may miss, causing the instruction fetch to be applied to the next higher memory level that operates with a higher memory capacity and slower access time. A miss may cause the processor to stall awaiting the instruction. In order to keep processor performance high, cache miss rates should be low.
An instruction cache is generally constructed with a plurality of instructions located at a single address in the instruction cache. This plurality of instructions is generally called a cache line or simply a line. A miss may occur on an instruction access anywhere in a cache line. When a miss occurs, rather than just fetching the needed instruction, the rest of the cache line, from the missed instruction to the end of the cache line, may also be fetched. In some systems, this technique of prefetching is further extended to always prefetch the rest of the cache line and the next cache line on a miss. This conventional technique of always prefetching the next cache line is based on an assumption that the next cache line contains instructions that will shortly be needed. This presumption of use of instructions in the next cache line remains valid even if, for example, a conditional branch is encountered in the line and the condition causes the branch to fall through to the next sequential instruction. By always prefetching the next cache line, misses may be reduced.
The locality principle of sequential access of instructions of course fails at some point in a program and misses do occur due to non-sequential operations caused by branches, calls and returns, or the like. A miss due to a sequential access may also occur, for example, when an instruction is fetched at the end of a cache line, and the next sequential instruction, which should reside in the next sequential instruction cache line, is not resident in the cache. A miss due to a non-sequential access may occur, for example, when a branch instruction is encountered and the branch causes the program address to change to a new location and the instruction at the new location is not resident in the cache. The conventional technique of always prefetching the next cache line fetches instructions that may not be used and consequently causes unnecessary loss of memory access bandwidth, increased power use, and lower processor performance.

Apparatus and methods for low-complexity instruction prefetch system


A terminal device is provided with a first casing, configured to accommodate the display part of the terminal device; a second casing, configured to accommodate the computation part and the heat dissipation part of the terminal device; a first shaft, provided on one side of the second casing, configured to be connected to the first casing and the second casing, with the first casing being able to rotate clockwise or counterclockwise around the axis of the first shaft; and a touch sensing unit, connected to the first shaft and configured to detect touch inputs from the user, wherein the touch sensing unit is provided between the first casing and the second casing and rotates clockwise or counterclockwise around the first shaft.

Nowadays, with the development of the touch technology, more and more terminal devices, such as notebooks, have touch functions. For example, some notebooks have keyboards and touch screens, thereby allowing users to input with keyboards or by touching. However, the costs of the notebooks described above are high. Further, in some notebooks, a touch screens is also provided on the host portion (body) of the notebook and a virtual keyboard is displayed on the touch screen so as to enable the user to input with the soft keyboard by way of touch. However, since two display screens are provided in the above-described notebook, it is difficult to control the thickness of the notebook, and the two display screens are bound to increase the cost and power consumption of the notebook.


A method and apparatus for variably enabling interaction across a USB interconnect between a host and a peripheral device capable of performing a plurality of functions including enabling selection and execution of a vendor-specific support software supporting peripheral devices of a specific vendor by sending a first identification data to the host indicating that the peripheral device is of the same specific vendor and indicating that the peripheral device performs at least one of the functions indicated to be supported by the vendor-specific support software, awaiting receipt of an indication from the host of a selected subset of the plurality of the functions of the peripheral device that are to be enabled, simulating a detachment from and attachment to the host; and enabling the vendor-specific support software to again be selected and executed by sending a second identification data to the host indicating that the peripheral device is of the same specific vendor and indicating that the peripheral device performs the selected subset of functions.

1. Field
The disclosure relates generally to USB hosts and peripheral devices, and more particularly, to apparatus and method for manipulating the support provided for USB by an operating system that is executed by a processor of a host to enable varying degrees of functionality in interactions between the host and a peripheral device attached to the host via USB interconnect.
2. Background Information
A number of years, ago, a group of computer and computer peripheral manufacturers formed an industry association to create a new digital interface for interconnecting various electronic devices. This new digital interface became and is widely known as USB (Universal Serial Bus). USB is a point-to-point interface in which there is a distinct master device (commonly referred to as a "host") and a distinct slave device (commonly referred to as a "peripheral device"). USB is most commonly used to connect one or more peripheral devices (e.g., scanners, cameras, printers and removable media drives) to a single host device (usually, a computer system such as a personal computer).
USB permits electronic devices to be attached to each other, automatically configured upon detection of their attachment, and detached from each other while still in operation. In other words, USB provides "hot-plugging" support that includes automatic configuration. To facilitate this, specifications were drafted for minimum requirements for a protocol for the automatic configuration and for support to be provided by an operating system executed by a processor of the host for "on-the-fly" changes of peripheral devices, in addition to specifications for the hardware interface.
Upon attachment of a peripheral device to a host, the host requests and the peripheral device provides identification data, including a vendor identity code and one or more device class codes. Vendors of peripheral devices for USB are assigned identity codes to allow their products to be distinguished from those of other vendors. A number of device class codes are defined for USB with each device class code specifying a function that a peripheral device may be capable of performing, such as the human interface device class (e.g., keyboards, mice and joysticks), the printing device class (e.g., dot matrix printers, ink jet printers and color printers), the scanning device class (e.g., flatbed scanners), and the mass storage device class (e.g., hard disk drives, removable media drives and flash memory devices). A peripheral device may be capable of performing multiple functions, and therefore, would provide multiple device class codes in the identification information sent to the host.
The identification data is used by an operating system executed by a processor of the host to select one or more pieces of support software from whatever pieces of support software are loaded onto the host to support interactions between the host and the peripheral device to allow the host to make use of the functions specified by the peripheral device in its identification data. To aid the selection of pieces of support software, each piece of support software carries data that at least partially mirrors the types of information provided by identification data from a peripheral device. A piece of vendor-specific support software supports only the peripheral devices of a specific vendor and provides the operating system with a vendor identity code specifying that vendor, whereas generic support software is not limited to supporting only the peripheral devices of a specific vendor. Both vendor-specific and generic support software further provide the operating system with device class codes specifying what peripheral device functions are supported by the support software. It should be noted that it is possible for a piece of support software, whether vendor-specific or generic, to supports only a single peripheral device function or to support multiple functions. It is also possible that a piece of support software supports only a subset of the functions specified by device class codes of the identification data of a given peripheral device such that multiple pieces of support software must be selected to support all of the functions of that peripheral device.
In selecting support software to support interactions with each peripheral device attached to the host, the operating system endeavors to achieve the best fit between each peripheral device and whatever support software is loaded on the host. It is generally accepted that the best possible fit is achieved by matching a given peripheral device with vendor-specific support software that is of the same vendor and that supports all of the functions specified by the device class codes in the identification data supplied by that peripheral device (whether this is with a single piece of vendor-specific support software, or multiple pieces). This is based on the presumption that the vendor of a given peripheral device will be in the best position to provide software that best supports it. However, where either there is no vendor-specific support software specifying that vendor, or there is insufficient vendor-specific support software to support all of the functions of the given peripheral device, then the operating system may choose generic support software to support some or all of the functions of that peripheral device. However, if there proves not to be either vendor-specific or generic support software present to support all of the functions specified by a given peripheral device by the device class codes of its identification data, then the operating system presents the user with a request to load the missing support software onto the host.
Since the introduction of USB circa 1995, various trends have arisen in how computers or other electronic devices functioning as hosts to one or more attached peripheral devices are employed by their users, such as which vendors' peripheral devices and/or which peripheral device functions are more widely desired. Since it is generally not practical for a vendor of an electronic device functioning as a host to provide all known pieces of support software for all peripheral devices already loaded on those electronic devices, such vendors often attempt to anticipate which peripheral devices or peripheral device functions (i.e., which classes of peripheral device) are most likely to be desired by users, and to load onto their products a subset of support software sufficient to support those users. The result has been that some functions that a peripheral device may provide may be very widely supported with the necessary support software already being loaded onto the vast majority of hosts by their vendors such that few users are ever presented with a request to load software for such functions. However, this leaves other functions that a peripheral device may provide with less certainty in the availability of software support. Most users of computer systems or other electronic devices functioning as hosts to one or more attached devices will find themselves asked to load support software at some point.
Although many users of computer systems or other electronic devices functioning as hosts to one or more attached peripheral devices will understand the meaning of a request presented to them to load supporting software, many other users will not. Furthermore, actually satisfying such a request often entails a search for the requested software, either by searching for a storage medium (such as a CD) that accompanied the peripheral device when purchased or by searching for a website from which the requested software may be downloaded. Although operating systems making requests for support software to be loaded by a user is arguably the logic result of the necessary support software not already being loaded on a host, and is in fact the current conventional result, due to the inconvenience caused to both savvy and not-so-savvy users, this result is not seen as being entirely satisfactory.
Similar numerals refer to similar parts throughout the specification.

This patent is subject to a terminal disclaimer.

Method and apparatus for variably enabling USB interaction


Integrated circuits and methods for deactivating user circuit operation with one or more wide channel sensing transistors biased to an on condition for exposure to total ionizing dose and then to an off condition for measurement and comparison of a leakage current or threshold voltage parameter to a predetermined reference, and a deactivation circuit selectively disables operation of the user circuit if the sensed parameter is greater than or equal to the reference.

Continuing performance improvements and scaling of semiconductor devices has generally resulted in operational capabilities in excess of minimum requirements for extraterrestrial applications such as satellites in which higher levels of radiation are experienced. However, devices capable of operating in high radiation environments may be subject to usage regulations established for satellite operation, such as International Traffic in Arms Regulations (ITAR), despite being designed for other uses. Such radiation hardened (rad-hard) products are typically regulated if they satisfy all performance criteria set forth in the ITAR regulations. One ITAR criteria relates to total ionizing dose (TID) which is characterized in terms of cumulative absorbed dose as a measure of deposited ionizing radiation energy per unit mass, such as joules per kilogram or rads. Commercializing potentially rad-hard devices in certain countries may involve obtaining export licenses or costly product testing and sorting to verify unsuitability for satellite operation, and such costs may inhibit the ability to export such products. Accordingly, improved integrated circuit designs and methods are desirable to ensure that ordinary products designed for non-satellite usage do not qualify for export restrictions per ITAR regulations.

Integrated circuit with automatic total ionizing dose (TID) exposure deactivation


The invention provides a phase lock loop (PLL) in a controller of an optical disk system and methods therefor. According to a preferred embodiment of the invention, the PLL comprises a write phase detector, a read phase detector, and a common read/write module shared by the write and read phase detectors. Further according to the invention, the common read/write module comprises a read/write mode selector coupled to the write and read phase detectors, a charge pump coupled to the mode selector, a loop filter coupled to the charge pump, and a voltage control oscillator (VCO) coupled to the loop filter.

1. Field of the Invention
The invention generally relates to optical disk systems and more particularly to a phase lock loop for a controller in an optical disk system and methods therefor.
2. Description of the Related Art
Optical disk systems such as digital versatile disk (DVD), compact disk (CD), DVD-ROM (digital video disk read only memory), DVD−RW, DVD+RW (digital video disk rewritable), CD-ROM and CD-RW are widely used in the art as the storage medium for data. Data are physically stored in the form of pits and lands patterned in a track on the disk. The tracks formed in a spiral line from the inner radius of the disk extending to the outer edge thereof. A pit is a location on the disk where data are recorded by creating a depression on the surface of the disk with respect to the lands. The lands are the areas between the pits in the tangential direction. When storing information on the disk, the length of the pits and lands are controlled according to a predetermined encoding format, such as eight-to-fourteen modulation (EFM). There are other encoding formats in the art suitable for patterning the puts and lands. EFM reduces errors by minimizing the number of zero-to-one and one-to-zero transitions where small pits are avoided. To retrieve information from the disk, light from a laser beam is directed onto the track where the light beam is reflected back to a photo-sensor. Because of different reflectivity in the pits and lands, the amount of reflected light changes at the transitions therebetween. The encoded pattern for the pits and lands modulates the reflected light beam. As the photo-sensor receives the reflected light beam, and outputs a modulated signal that is proportional to the energy of the light in the reflected light beam. In EFM, the data signal includes no less than two zeros and no more than ten zeros between logical transitions at the pit edges. A zero is indicated by no change in the energy of the reflected beam for at least two clock periods. A one is indicated by a change in the energy of the reflected light beam, i.e., a pit edge. Applying EFM, a pit or land includes a length corresponding to the amount of time for at least two and up to ten clock periods where a corresponding voltage is accordingly output.
In EFM encoding, the number of clock periods having a digital value of one should be equal to the number of clock periods having a digital value of zero over a period of time. A clock signal is derived from the digital data signal by a phase lock loop (PLL) in a controller of the optical disk. Provided that the clock includes a clock period T, the EFM signal has digital values of ones and zeroes for integer multiples of the clock period T. A PLL is provided in the controller for each functionality in operating the disk (such as reading and writing information). The PLL ensures proper clock speed in the EFM encoding. For multiple functionalities, such design requirements become cumbersome and inefficient in the art. Significant shortcomings include restrictions in the size and cost of implementation for the controller design of the optical disk.
Thus, there is a general need in the art for an optimally and efficiently designed controller for an optical disk, and more particularly, an optimally and efficiently designed PLL for the controller in an optical disk and associated methods therefor that overcome at least the aforementioned shortcomings in the art.

Phase lock loop for a controller in an optical disk system and methods therefor