Abstract: An annular groove portion is formed between portions corresponding to groove portions and thereafter the groove portions are formed while the annular groove is pressed. Consequently, since the stress produced due to a plastic deformation in forming the groove portions can be absorbed by the annular groove having a smaller rigidity than the groove portions, no undesirable plastic deformation of the groove portions occurs and hence the accuracy of the finished size of the multi-stage pulley can be improved. Furthermore, the capital investment in groove forming rollers can be reduced and the manufacturing cost of the multi-stage pulley can be reduced.

Abstract: The manufacturing cost of a multi-stage pulley is reduced without coaxially arranging a plurality of groove forming sections. While a portion between groove sections 103 is being pushed by a pushing roller 204, the groove sections 103 are successively formed. While a portion of workpiece W2 pushed by a groove forming roller 206 to form one groove section 103a and a portion of workpiece W2 pushed by a groove forming roller 207 to form the other groove section 103b are being shifted from each other in the circumferential direction, one groove section (103a) and the other groove section (103b) are simultaneously formed. Due to the foregoing, when the groove sections 103 are formed, it is possible to prevent the deformation of the groove section 103 and the groove section 103 which is adjacent to it. Accordingly, it is possible to enhance the yield of the multi-stage pulley 100 without coaxially arranging a plurality of groove forming sections.

Abstract: An annular groove portion is formed between portions corresponding to groove portions and thereafter the groove portions are formed while the annular groove is pressed. Consequently, since the stress produced due to a plastic deformation in forming the groove portions can be absorbed by the annular groove having a smaller rigidity than the groove portions, no undesirable plastic deformation of the groove portions occurs and hence the accuracy of the finished size of the multi-stage pulley can be improved. Furthermore, the capital investment in groove forming rollers can be reduced and the manufacturing cost of the multi-stage pulley can be reduced.

Abstract: In forming a multi-grooved V pulley by roll forming, a preliminary forming method is disclosed for preventing the occurrence of a top roll accompanied by a crack along each annular ridge of the pulley. A preliminary form roller is pressed against an annular material to fabricate a preliminary form having, in a sectional view, a corrugation including linear flat root portions and ridges alternating with them on the bottom surface of a wide annular groove. Next, a finish form roller having a plurality of annular V-shaped protrusions is pressed against the linear flat root portions of the preliminary form to thereby finish roll the preliminary form. The forward end of each V-shaped protrusion is kept off from the slopes of the corrugation ridges, and therefore is not broken under a bending moment.

Abstract: A coordinate input apparatus of the present invention in which operation is switchable from an image pickup mode for displaying on a display apparatus an image of an object for image-taking to a coordinate input mode for inputting coordinates at a location indicated by a point indicator and vice versa, so that when the coordinate input mode is set, the duration of scanning by an image pickup element is controlled shorter than that in the case of the image pickup mode being set, whereby the duration required for image pickup during coordinate input mode operation can be reduced and speedy processing can be achieved for coordinate inputting, and which is provided with an image processing circuit for optimum image processing with respect to image signals for images taken, so that images taken in short image pickup duration during coordinate input mode can be prevented from deterioration.

Abstract: In an image pickup apparatus according to the present invention, a rotary scanning mirror (2) is rotated to sense the image of an original (10) by a linear image sensor (4), which in turn outputs picture signals to be stored in a frame memory (5), so that the image of the original (10) is displayed on a display unit (6) on the basis of the stored picture signals. A light pen (9) specifies a scanned range of the image displayed on the display unit (6) and a controller (8) indicates rotation angles of the rotary scanning mirror (2) on the basis of position signals from the light pen (9) to specify the scanned range while varying the step size of the rotary scanning mirror (2) thereby to vary resolution. Thus, a noted region in the original (10) can be easily image-sensed in high resolution.

Abstract: A band compression apparatus for transmitting a video signal having three color component signals sampled at a sampling frequency of 2Fs and a gradation of N bits per picture element by a transmission path of a gradation of N bits per sample and a sample transmission frequency 2Fs includes a prefilter for restricting the band of each color component signal; a sub-sample circuit for compressing the respective band restricted color component signal to a sampling frequency Fs; a signal separation switching circuit for separating data of 3n bits comprising the upper n bits of the sub-sampled color component signals3n=2N+k (k<N)into two main signals as transmission samples of N bits and a fraction signal of k bits; a fraction signal storage RAM for storing one line video signal portions of said fraction signal; and a signal outputting switching circuit for outputting said stored fraction signal to the transmission path by time compressing the same into a signal of N bits as a first transmission sample during th