Abstract: A reproduction device, contains a rotatable operation disk part for performing an input related to reading of data stored in a memory and a capacitance sensor section for outputting a sensor value expressing a change of a capacitance according to depression of the rotatable operation disk part. The device also contains a storage part for storing a reference value corresponding to the sensor value obtained while the rotatable operation disk part is not depressed, and a control part for judging presence/absence of pressing on the rotatable operation disk part based on a vector quantity being a relative value obtained from a difference between the sensor value output from the capacitance sensor section and the reference value stored in the storage part.

Abstract: A portable object such as, in particular, a timepiece, including an electronic movement carried by a printed circuit (20), this electronic movement including a time base circuit, a frequency divider circuit powered by the time base, a control circuit (22) connected to the divider circuit and a display system controlled by the control circuit, this portable object also including at least one push-button (8, 10) including a head (26) and a stem (16) passing through the middle part (4) of a case (2) closed by a back cover (6), characterized in that the push-button stem (16) can be electrically connected to a data input (42, 44) of the control circuit (22) by pressing on the push-button (8, 10), so that it is possible, via this stem (16), to enter data into said control circuit (22), originating from an electronic unit (45) for transmitting and receiving digital data such as a personal computer or PC or to extract data contained in said portable object.

Abstract: A disc-like record carrier has a machine-readable information track in which is provided record carrier control information including the actual physical diameter of the carrier.

Abstract: A disc-like record carrier (1) has control information recorded. The control information comprises diameter information which is indicative of the diameter of the record carrier. An information recording and/or reading apparatus involves a drive structure for rotatingly driving the disc-like record carrier. The apparatus includes a control unit which adapts the loop gain of a control loop for controlling the number of revolutions per minute of the record carrier in dependence on the control information recorded on the record carrier.

Abstract: A planar shape characteristic measuring apparatus, and a planar shape characteristic measuring method, which can precisely and efficiently measure the characteristics relating to a surface shape of the measured surface of a disk such as a data recording surface of an optical disk including a laser Doppler speed meter which detects a perpendicular direction speed of a measured surface of a rotating disk; a tilt angle calculating unit which calculates a tilt angle in the rotational direction of an optical disk at each measuring position to a reference surface based on a linear speed at each measuring position detected by the laser Doppler speed meter and the detected perpendicular direction speed; a displacement calculating unit which calculates a perpendicular direction displacement of the optical disk at each measuring position; an acceleration calculating unit which calculates a perpendicular direction acceleration; and a tracking error calculating unit which calculates a tracking error which is predicted to

Abstract: A constant linear velocity control (CLV control) for controlling a spindle motor so as to set a linear velocity in a track circumferential direction to be constant and a constant angular velocity control (CAV control) for controlling the spindle motor so as to set a rotation of a medium to be constant are switched and controlled for a change in position in the radial direction of the medium of a pickup in accordance with a detection result of the medium loaded. In the switching control, selection information of the CLV control and the CAV control is previously registered in accordance with the kind of medium and the CLV control or the CAV control is selected in accordance with the corresponding selection information obtained from the detection result of the medium.

Abstract: The presence of a disk cartridge in a disk drive is detected by obtaining a measure of the load on the spindle motor of the disk drive and comparing that measure to a threshold value. The measure of load on the spindle motor may comprise (i) the time the spindle motor takes to spin-up to its full operating speed, (ii) the time the spindle motor takes to coast down to its operating speed from a first speed in excess of the operating speed, (iii) the voltage applied across the coils of the spindle motor, or (iv) the current drawn by the spindle motor.

Abstract: A disk drive capable of determining the diameter of the currently loaded disk in a short time without the use of additional attachments such as optical sensors. Servo gains are first set to permit rotation of a 12-cm CD, and the servo is turned on. The CD is rotated at a steady rotational speed regardless of its diameter. The servo is turned off when a sub-code synchronizing signal is detected from the CD. Acceleration pulses are generated to start accelerating the spindle motor simultaneously with the starting of a timer. The timer is stopped when the next sub-code synchronizing signal is detected, and the servo is again turned on. If the value on the timer is longer than a reference time, the loaded CD is found to be a 12-cm CD and the appropriate servo gains are set for the 12-cm CD; if the timer value is shorter than the reference time, the CD is found to be an 8-cm CD and the servo gains are set accordingly.

Abstract: A method of discerning an optical disk in a compact disk drive which includes the steps of moving an optical pick-up device to a table of contents (TOC) region of an optical disk to perform a focusing operation for reading data from the optical disk, and discerning whether an optical disk is loaded on a turntable of the compact disk drive. When the optical disk is loaded in the compact disk drive, the loaded optical disk is rotatably driven by a spindle motor. The time necessary for the rotating speed of the optical disk to reach a predetermined speed is counted, and the counted time is then compared with a predetermined time to determine whether the optical disk is one of a first type having, for example, a eight centimeters diameter and a second type having, for example, a twelve centimeters diameter. If the counted time is less than the predetermined time, the loaded optical disk is determined as a eight centimeters disk. If, on the other hand, the counted time is not less than the predetermined time, i.e.

Abstract: A semiconductor memory device includes first and second MOS transistors connecting a pair of data lines with a specific potential supplying node. A power transmitting circuit couples the specific potential supplying node with a power supply circuit of an equalizing potential after said first and second switching elements are made conductive. The power transmitting circuit isolates the specific potential supplying node from the power supply circuit when the equalization begins. As an alternative to the power transmitting circuit, a supplying circuit may be connected to supply a precharge potential to the specific potential supplying node when the equalization begins, and supply an equalizing potential to the specific potential supplying node when the switching elements are both turned on.

Abstract: An object of this invention is to provide a disk player in which a plurality of disks different in diameter are driven, and can be identified with high accuracy. Disclosed is the disk player, a digital signal processing section applies to a CPU a synchronization signal which is raised to high level when the frequency of a detection signal outputted by a laser pickup reaches a predetermined value which permits a data reading operation, and a sense signal which is raised to high level when the frequency of the detection signal is shifted from a predetermined frequency. The CPU operates to rotate a spindle motor, and to brake the latter when the synchronization signal is raised to high level. The CPU further operates to detect a period of time which lapses from the time instant the motor is braked until the sense signal is fallen to low level, and to identify the loaded disk from the period of time thus detected.

Abstract: An apparatus for rotationally driving an optical disk in an optical disk recording and/or reproducing apparatus capable of recording or reproducing signals from disks having different sizes includes a spindle motor for rotationally driving a disk, a servo unit for controlling the rotation of the spindle motor, and a control unit for detecting an activation response state of the spindle motor upon starting, and switching a gain of the servo unit on the basis of the detection result.

Abstract: A rotation control system for disk player in which the player detects the size of a disk housed in the player, varies the starting torque to be given to the disk motor in response to the detected size, and controls the disk motor so as to require substantially the same length of time before a prescribed rotational frequency is attained, irrespective of the size of the disk.

Abstract: A front loading disk player has an insertion slot for receiving variable sizes of disks to be played. As the disk is inserted it encounters pinch rollers on the free ends of pivoting arms. The pressure on the pinch rollers is sensed causing the arms and their support members to move transversely of the insertion direction to open up and accommodate the diameter of the specific disk while still pinching the edge of the disk. When the disk reaches a certain stage of insertion where the central portion is past the insertion slot, the pinch rollers, arms and support members take over and pull the disk all the way into the disk player and place the disk on a turntable.

Abstract: In a compatible recording and reproducing apparatus which is capable of recording and reproducing information on both a video disk and a digital audio disk, a relative angle between an optical axis of a laser beam emitted from a pickup and the disk is adjusted so as to be suitable for the disk loaded on the apparatus. Further, the movement of the pickup in the radial direction of the disk is regulated in accordance with the difference in the outer diameter of the two kinds of disks. A problem due to the difference of the track pitch in the two kinds of disks is solved by moving the pickup in a direction perpendicular to a radial direction of the disk. In addition, an objective lens for focusing the laser beam on the disk is selected within a predetermined range of an effective numerical aperture in order to simplify an optical system of the apparatus.

Abstract: In a disk size detecting circuit, the size of a disk is determined according to the speed of a motor adapted to rotate the disk and the angle through which motor has rotated after the start thereof. A counter, which is reset with the signal which starts the operation of the motor, counts pulses indicative of the amount of rotation of the motor. A rotational speed detector circuit, which may take the form of a frequency-to-voltage converter followed by a voltage comparator or a frequency counter followed by a digital comparator, produces a signal indicating the rotational speed of the motor. The output of the counter and the output of the rotational speed detector are applied to a circuit which discriminates the size of the disk according to the two signals.