Abstract: A method for growing a silicon crystal by a Czochralsky method, wherein, let a pulling speed be V (mm/min) and an average value of an in-crystal temperature gradient in a pulling axis direction within a temperature range, a silicon melting point to 1350° C., be G (° C./mm), V/G ranges from 0.16 to 0.18 mm2/° C. min between a crystal center position and a crystal outer periphery position, and a ratio G outer/G center of an average value G of an in-crystal temperature gradient in a pulling axis direction within a temperature range, a silicon melting point to 1350° C., at a crystal outer surface to that at a crystal center is set to up to 1.10 to thereby obtain a high-quality perfect crystal silicon wafer. Such a perfect crystal silicon wafer, wherein an oxygen concentration is controlled to up to 13×1017 atoms/cm3, an initial heat treatment temperature is at least up to 500° C. and a temperature is raised at up to 1° C./min at least within 700 to 900° C.

Abstract: There are provided a system for manufacturing a single-crystal ingot which is equipped with a cooler for cooling the single-crystal ingot being pulled and is capable of forming a tail without involvement of excessive heating of a crucible, as well as to a method for controlling the system. In a system for manufacturing a single-crystal ingot having a cooler for cooling a single-crystal ingot which is being pulled from molten raw material (called a single-crystal pulled ingot), when a tail of the single-crystal pulled ingot is formed, the cooler is moved away from the solid/melt interface between the single-crystal ingot and the molten raw material, to thereby reduce the power dissipated by the system. In the system, the cooler is moved upward after the end of a product area of the single-crystal ingot has been cooled until it passes through a grown-in defect temperature range.

Abstract: A method and apparatus for winding synthetic fibers is disclosed. According to the invention, a yarn is wound around a bobbin without winding a tail bunch, at a high successful bobbin-to-bobbin yarn transfer rate for a variety of yarn properties, i.e. different in thickness, lubricant used, etc., while inhibiting the loosening of the yarn tail into single fibers and stably and easily forming a proper yarn tail length. Tail bunch removing work is not required and the winding process is stabilized. A yarn is wound around an empty bobbin using a yarn winding apparatus composed of a traverse fulcrum guide, a traverse device, a contact pressure roller, two spindles, a moving device for moving the spindles, and a yarn transfer device for introducing the yarn into a yarn holding portion for holding the yarn.

Abstract: The cooling speed of the portion near the rear part of a single-crystal body and passing through the defect-forming temperature zone is kept the same as that of the front portion of the single-crystal body. Namely, the heater is kept in operation while pulling the single crystal silicon subsequent to forming the tail of the single crystal silicon and the cooling speed throughout the whole single-crystal body in the defect-forming temperature zone is kept below 15.degree. C./min (levels A and B). Furthermore, the length of the tail is preset in the process of pulling the single crystal silicon so that the single-crystal body cools down slowly while passing through the defect-forming temperature zone (level C).

Abstract: A method for fabricating a semiconductor single crystal by the MCZ method by which it is possible to pull large diameter and heavy semiconductor single crystals without breaking the contraction portion, is provided.In the contracting step, change the shape of the crystal growth interface by making the range of the temperature fluctuation caused by convection in the vicinity of the melt surface more than 5.degree. C. so as to eliminate the dislocation in the contracted portion. When a transverse magnetic field is applied by magnets 6,6, the magnetic field intensity is set below 2000 Gauss to properly change the shape of the crystal growth interface to form the contracted portion 10. Thus,even though the diameter of the contracted portion 10 is larger than normal, free dislocation is achieved. After the dislocation is eliminated, the magnetic field intensity is recovered and shoulder 11 is formed.

Abstract: In ultrasonic imaging method/system, a deep interior portion of a biological body under medical examination can be scanned by blood-flow image scanning beams with a wide view field.

Abstract: An ultrasonic imaging apparatus comprises an ultrasonic transducer for propagating ultrasonic beams to a subject, and converting echo beams reflected from the subject into an echo signal, a focus switch circuit for setting a plurality of focal depths, and a focus control circuit for outputting delay signals corresponding to the focal depths set by the focus switch circuit. The focus control circuit changes the delay signals corresponding to the preset focus depths to signals corresponding to the focus depths that are located within a display range, especially when the ultrasonic image is enlarged and shifted with at least one of the preset focus depths out of the display range.

Abstract: An ultrasonic imaging apparatus includes an ultrasonic transducer having a matrix of a plurality of ultrasonic transducer elements, and a transmitter/receiver circuit for driving the ultrasonic transducer elements with delay control so that the ultrasonic transducer selectively generates ultrasonic beams in X and Y scanning directions. A marker is set in a tomographic image obtained by scanning a subject in the X direction. The subject is scanned in the Y direction along the marker. A section image corresponding to the marker is output.

Abstract: An ultrasonic imaging arrangement. The arrangement includes a probe having an array of oscillators for emitting ultrasonic waves toward an object to be tomographically imaged, a first converter, a line memory group including a plurality of line memories, a write zoom operation unit, a frame memory, read zoom operation unit and a second converter. Echo signals reflected from the object are converted into digital signals as ultrasonic data. The ultrasonic data are stored in the line memory group, and are stored in the frame memory after processing operations in the write zoom operation unit. The read zoom operation unit then reads the data from the frame memory and, if necessary, processes that data. The second converter converts the processed data into video signals and a tomography image of the object is displayed according to the video signals.