摘要:
An optical or magneto-optical disk storage which automatically adjusts a recording/reproducing level of a number of kinds of optical or magneto-optical disks having different recording/reproducing levels to an optimum recording/reproducing level. The optical or magneto-optical disk storage has an attenuator which applies a predetermined attenuation amount to a reproduced signal reproduced from an optical or magneto-optical disk so as to attenuate the reproduced signal, or intensity adjusting means for adjusting the intensity of a laser beam used for recording and/or reproducing. The optical or magneto-optical disk storage detects an amplitude of the reproduced signal and feed-back-controls the attenuation amount or intensity of the laser beam in accordance with the detected amplitude.
摘要:
When recording, reproducing or erasing data signal by illuminating a recording medium surface with a condensed light spot, a tracking sensor signal or a focusing sensor signal is detected from light reflected from the recording medium surface. The detected signal is subjected to current-to-voltage conversion, and the current-to-voltage conversion gain is switched by estimating reflected light power from the recording medium surface.
摘要:
An optical disc having a plurality of information tracks. Each information track having a data field including multiple data bytes and a servo field including a first servo byte having a pair of wobbled pits and a second servo byte having a clock pit. The byte length of at least one of the first or second servo bytes being longer than the byte lengths of the data bytes. The increased byte length providing for greater distance between the wobbled pits and the clock pit resulting in increased reliability in clock pit detection. An accessing apparatus for accessing such an optical disc including a phase-locked loop circuit with a frequency dividing ratio that varies in accordance with the various byte lengths.
摘要:
An optical disc having a plurality of information tracks, each information track having a servo field including a pair of wobbled pits and the clock pit. The distance between one of the wobbled pits and the clock pit in each servo field is selected so that the optical disc includes at least three different types of servo field. These different types of servo field appear in a predetermined sequence for every one or more contiguous information tracks. A transducing apparatus for tranducing such an optical disc has a direction detecting circuit for detecting the moving velocity of a movable portion of an optical head, and a speed detecting circuit for detecting the relative velocity of the movable portion.
摘要:
In an optical disk storage, the seek of an optical head is controlled so that the number of seek times cannot exceed a threshold number of times in a predetermined period or an accumulated seek period cannot exceed a threshold period in a predetermined period. Therefore, a wasteful power consumption and a rise in the internal temperature associated with the seek activity can be effectively prevented.
摘要:
An optical disc having a plurality of information tracks, each information track having a servo field including a pair of wobbled pits and a clock pit. The distance between one of the wobbled pits and the clock pit in each servo field is selected such that the optical disc includes at least three different types of servo field. These differnt types of servo field appear in a predetermined sequence for every one or more contiguous information tracks. A driving apparatus for driving such an optical disc has a direction detecting circuit for detecting the moving velocity of a movable portion of an optical head, and a speed detecting circuit for detecting the relative velocity of the movable portion.
摘要:
A recording medium drive apparatus has a first detector for detecting tracking information and a second detector for detecting focusing information when magnetization information and pit information recorded on an optical disc are reproduced and detected. This apparatus also comprises a preamplifier having the function of selecting by a control signal either a mode for adding and amplifying output signals of the first and second detectors by utilizing a predetermined gain or a mode for subtracting and amplifying those output signals by utilizing another predetermined gain, of unconditionally selecting the polarities of the added and subtracted amplification signals by means of the control signal, and of selectively outputting signals V.sub.i (i=1, 2, 3, 4).
摘要:
A disk apparatus comprising a controller receiving commands from a command input device and controlling an entire operation of the disk apparatus. The rotating control function is coupled to the controller for controlling the first motor. The pickupmotor control function is coupled to the controller for controlling the second motor. The pickup control function is coupled to the controller for controlling a focusing operation and a tracking operation of the pickup. And the signal processing function is coupled to the controller for processing a recording signal to be recorded on the disk-shaped recording medium and a reproduced signal read out therefrom. The controller is comprised function-stop function for determining whether or not any command is received from the command input device during a predetermined period of time in a state. The disk apparatus is maintained in a predetermined mode and for stopping predetermined function among the rotating control function, the pickup motor control function, the pickup control function, and the signal processing function when it is determined that no command is received from the command input device during the predetermined period.
摘要:
A binary data encoding process comprises the steps of separating a given binary data sequence at every two bits by a serial/parallel shift register (18), and converting the separated 2-bit data into a 3-bit code by using a logic circuit (19) and a parallel/serial shift register (20). A conversion pattern in the logic circuit (19) is exclusively determined based on the 2-bit data to be converted, 1-bit data immediately before and 2-bit data immediately after said 2-bit data, and a 3-bit code converted immediately before the conversion of said 2-bit data, wherein a succession of at least one but no more than seven "0" exists between an arbitrary "1" and the succeeding "1" in the converted 3-bit code sequence.
摘要:
A multichannel digital magnetic recording apparatus comprises a plurality (N) of modulating circuits (41 to 4N) and timing circuits (51 to 5N). Digital signals (Z1 to ZN) undergo modulation in the modulating circuits in accordance with a modulation system of a detection window Tw. The modulated signals (A1 to AN) are converted into pulse current trains by the timing circuits and then delayed such that the respective pulse currents do not occur simultaneously. Accordingly, a power capacity required of a voltage source for writing the signals by means of thin film magnetic heads (71 to 7N) is considerably decreased.