Abstract: A digital pen includes a light emitting element configured to emit a light ray of a specific wavelength region; a pen tip configured to emit the light ray on a writing surface; a sensor configured to output information indicative of whether the pen tip contacts the writing surface; a controller configured to detect if the pen tip contacts the writing surface based on the information from the sensor; and a holding mechanism configured to hold pressure applied onto the sensor to be constant, through an elastic force of an elastic body. The controller determines that the pen tip contacts the writing surface when the sensor is free from the pressure, thereby dissolving a problem of an uncomfortable feeling for a user, which is caused by the fact that the track written by the digital pen is not immediately reflected on a screen.

Abstract: A uniformity correction signal generating apparatus includes a horizontal address signal generating unit and a vertical address signal generating unit for generating address signals (X) and (Y, y) having one-to-one correspondence to a position on a display screen of a display unit, respectively. Upper and lower adjacent lattice point data are read out from an E.sup.2 PROM on the basis of the address signals X and Y. Interpolated correction data are obtained on the basis of the upper and lower lattice point data and vertical lower address coordinates y. The apparatus is suitable for an auto-scan type display unit and can correct the uniformity for gradation and focus by using the inexpensive E.sup.2 PROM without need of a large capacity expensive E.sup.2 PROM.

Abstract: A focus yoke used for an electromagnetically focused CRT display comprises: a cylindrical permanent magnet unit which is disposed around a neck portion of a CRT and is spaced from the circumference of the neck portion; a core unit which defines a toroidal space together with the cylindrical magnet unit for substantially surrounding the neck portion, the core unit forming a magnetic path to guide magnetic lines of force generated by the cylindrical magnet unit; a dynamic focus winding unit disposed in the toroidal space; and a winding unit disposed externally of said toroidal space for eliminating an undesired magnetic field of an inverse polarity generated due to the cylindrical magnet unit.

Abstract: Electric charges are stored on a capacitor and then the charges are discharged so that a sawtooth wave for use in a convergence correction circuit for a display or the like is generated. When the sawtooth wave is used for a multi-scan display, the charge period is varied according as the scanning frequency varies, and as a result, a phase error is produced in the parabolic wave obtained by squaring the sawtooth wave. To eliminate the phase error, it is adapted such that the discharging current from the capacitor is passed through a coil and, in addition, the period as the reciprocal of the resonant frequency of the resonance circuit formed of the coil and the capacitor is set to be virtually double the discharge period.

Abstract: A disk playback device includes a magazine for several disks and trays for supporting the disks, a magazine housing for the magazine, a disk playback section for playing back data recorded on a disk and a tray transport section for transporting a tray, supporting a selected disk, between the magazine and the playback section. In one embodiment, the playback device includes a disk guide for securely placing a played back disk onto its associated tray. In another embodiment, the playback device includes a disk guide for guiding disks of various diameters. In another embodiment, the playback device includes an optical detecting element for detecting whether a tray contains a disk. In another embodiment, the playback device includes a switch for detecting whether a magazine has been inserted and locked in the magazine housing. In another embodiment, the playback device includes a guide mechanism for securely guiding a disk clamper to a selected disk for playback.

Abstract: A disk reproduction apparatus of the type capable of being displaced from a horizontal attitude to a vertical attitude or vice versa includes an outer casing; a support frame disposed inside the outer casing in a floating manner and loaded with a magazine in which a compact disk is mounted; a vibration proof mechanism disposed between the corresponding side surfaces of the outer casing and the support frame; and a pickup device disposed above the compact disk, and being movable and adapted to read the information recorded on the compact disk. The vibration proof mechanism includes a support, such as a rotating plate, pivotally secured to the side surface of the outer casing, and a spring having one end engaged with the pivotal rotating plate and the other end secured to the side surface, opposing to the side surface of the outer casing, of the support frame. Several vibration proof mechanisms may be disposed on both side surfaces of the outer casing and the support frame.

Abstract: Compensating arrangements compensate for variations in load which a disk magazine places on a drive motor. In a first arrangement, a cam slot of a predetermined spiral configuration receives driving force from a drive motor and translates the same to: an end-range force from an initial portion of the cam slot which causes the selected tray to rotate at a first speed; an intermediate-range force from a middle portion which causes the selected tray to rotate at a second speed which is higher than the first speed; and, an end-range force from a final portion which causes the selected tray portion to rotate at a third speed which is lower than the second speed.

Abstract: A convergence correction circuit according to the present invention has a phased locked loop including a programmable counter. The programmable counter has programmable count start and end points. The output of the programmable counter is supplied to a memory storing convergence distortion correcting data therein. As the horizontal screen size is increased, a value closer to the lower limit 0 of the start point as compared with that taken when the horizontal size is small is set as the count start point of the programmable counter, and a value closer to the upper limit (2.sup.7 -1) of the end point as compared with that taken when the horizontal size is small is set as the count end point. In accordance with the horizontal screen size, the count start and end points of the programmable counter are changed. Correct convergence correction is performed even if the horizontal screen size is changed.

Abstract: The present invention relates to a miss convergence compensating circuit of a projection type display. The projection type display is provided with three projection tubes for red, green and blue colors and a color image is obtained by combining three colors from three projection tubes on a screen. When such projection tubes are arranged slant to the screen, miss convergence is generated on the screen. A convergence yoke for auxiliary deflection of electron beam is generally provided in order to compensate for such miss convergence, but this convergence yoke has the deflection sensitivity which is worse than that of deflection yoke. Therefore, the present invention contributes to compensate for miss convergence using the deflection yokes. For this purpose, at least two deflection coils are provided with a transformer coupling which allow the compensating currents corresponding to the miss convergence compensating signals to flow.

Abstract: A convergence apparatus in which a sawtooth wave signal having a horizontal period is modulated by a sawtooth wave signal having a vertical period and supplied to a convergence coil to correct misconvergence of rasters on the projection screen, characterized in that the sawtooth wave signal having the horizontal period is derived by integrating a pulse advanced in phase as compared with the flyback pulse by a PPL circuit and hence the distortion of the sawtooth wave signal having the horizontal period exists within a horizontal blanking period.

Abstract: An automatic disc player including a housing having an elongated slot through which a disc is to be inserted, playback means accommodated within the housing and including a turntable to carry a disc during playback operation, disc carrier means to convey the disc toward a predetermined position with respect to the turntable after the disc is inserted through the slot in the housing, and disc clamp means to move the disc correctly to the predetermined position after the disc is conveyed toward the predetermined position by the disc carrier means, wherein the disc clamp means comprises a support member movable between a release position remoter from the turntable and a disc clamp position closer to the turntable, and a disc clamping member which is rotatably supported on the support member through an elliptical opening formed in the support member and which is cooperative with the turntable for having a disc clamped between the turntable and the disc clamping member when the support member is in the disc clamp