Abstract: According to a first aspect of the invention, digital image data are recorded in the form of compressed codewords with check information and flags. The flags indicate codewords containing uncorrected errors. Each time the data are copied, error detection and correction are performed and the flags are updated to indicate any new uncorrectable errors that are detected. The flags can be used for error concealment, to avoid error miscorrection, and to permit the check information to be regenerated each time the data are copied. According to a second aspect of the invention, when image data are copied, the same check information is used to perform error detection and correction twice. Flags identifying uncorrected errors can be transferred from the first error-detecting-and-correcting process to the second.

Abstract: A magnetic recording and reproducing apparatus for recording and reproducing plural types of data signals respectively different in data rate, and capable of completely eliminating noise when reproducing data signals of high data rate or low data rate at slower or faster speed than normal speed.

Abstract: Codewords with CDS=0 are mapped in corresponding relationship to datawords, and codewords with CDS>0 and codewords with CDS<0 are paired together and mapped in corresponding relationship to the remaining datawords, and further, codewords with CDS.noteq.0, left unmapped, are mapped in corresponding relationship to the datawords to which the codewords with CDS=0 have been mapped, thus reducing the probability of occurrence of codewords with large DSV in absolute value terms and thereby achieving a further suppression of low-frequency components. Based on the least significant bit of the codeword corresponding to the last dataword and on the current and next datawords, a codeword corresponding to the current dataword is selected, thus realizing high-density recording with good overwrite characteristics.

Abstract: The specification discloses a recording and reproducing apparatus for dividing a video signal of one field into a plurality of segments and recording the video signal onto a plurality of tracks on a recording mediuim. By the recording and reproducing apparatus, an additional period is inserted between the adjoining segments. Further, the signal included in one of the adjoining segments is used as a signal of the additional period.

Abstract: A control apparatus of a transistor motor comprises an addition reference setting circuit (203), a positive voltage addition circuit (204 and 207), a negative voltage addition circuit (205), and a positive/negative voltage addition circuit (202). The addition reference setting circuit (203) is adapted to produce reference values VC and VD. The addition is made of the magnitude of the positive-going component with respect to the reference value VC out of the peak values of the feedback voltages (VU, VV and VW) in the positive voltage addition circuit, whereby the output VAA is provided. Addition is also made of the magnitude of the negative going component with respect to the reference value VD out of the peak values of the feedback voltages in the negative voltage addition circuit, whereby the output VB is provided. The above described outputs VAA and VB are added to each other in the positive/negative voltage addition circuit, whereby the output VE is provided.

Abstract: A plurality of slots are disposed at equal angular intervals on one portion of a circular ring-shaped field magnet fixed to a motor's rotor to run radially of the magnet. Alternatively, short rods made of a soft magnetic material may extend radially outwards from the lateral surface of the magnet to form the slots between them. Three magnetic sensor elements are disposed at equal angular intervals of 120 degrees on a motor's stator to face successively the slots during the rotation of the rotor.

Abstract: A method and machine for use in hydrostatic extrusion wherein a portion of an elastic-plastic viscous pressure medium is introduced into the rear portion of a container, with the rear end thereof being sealed in a fluid tight fashion. The pressure medium being of such a nature that it has a high viscosity and cannot flow by itself. Subsequently, a billet is charged into the container and then a die is mounted in the container at the forward end thereof. The aforesaid pressure medium is caused to fill around the outer circumferential surface of the billet. In this respect, a high pressure seal is provided for the junctions between the die and the forward end of the container and between the die and the forward end of the billet before the pressure medium flows out of the container in a practically negligible small amount, immediately after which a pressure stem is pushed into the container from the rear end thereof, thus proceeding with the hydrostatic extrusion.

Abstract: A hydrostatic extrusion method and apparatus for the extrusion of tubes is disclosed wherein the simplified structure of the nose or tip portion of the billet and the cooperating surfaces of the die defining the die cavity and those of the mandrel facilitate an improved initial sealing among the associated surfaces of the die, billet and mandrel. Such an initial sealing is effected between such interfaces of the members and billet at a point which is located substantially rearwardly from the position at which the actual extrusion to the final tubular configuration occurs between the bearing portion of the die and the cooperating sizing portion of the mandrel. Such structure and method permits the extrusion of tubes having walls of asymmetric or non-circular configurations in cross section, even those of complex configurations.

Abstract: A method and machine for use in hydrostatic extrusion wherein a portion of an elastic-plastic viscous pressure medium is introduced into the rear portion of a container, with the rear end thereof being sealed in a fluid tight fashion. The pressure medium being of such a nature that it has a high viscosity and cannot flow by itself. Subsequently, a billet is charged into the container and then a die is mounted in the container at the forward end thereof. The aforesaid pressure medium is caused to fill around the outer circumferential surface of the billet. In this respect, a high pressure seal is provided for the junctions between the die and the forward end of the container and between the die and the forward end of the billet before the pressure medium flows out of the container in a practically negligible small amount, immediately after which a pressure stem is pushed into the container from the rear end thereof, thus proceeding with the hydrostatic extrusion.