Abstract: A system and method of drawing a visible image on an optical disk are provided. The optical disk is rotated while a optical pickup irradiates a laser beam onto the optical disk to draw the visible image on the optical disk. The rotating state of the optical disk is detected. The optical pickup is fed in a radial direction of the optical disk. An irradiating position of the laser beam is controlled relative to the optical disk by fixing the laser beam in the radial direction of the optical disk during one rotation of the optical disk, and shifting the irradiating position of the laser beam by a first distance in the radial direction each time one rotation of the optical disk is detected. The optical pickup is fed in the radial direction by a second distance the optical disk has rotated a predetermined number of rotations.

Abstract: A phase difference detection circuit (270) and a gain adjusting circuit (280) are provided in an optical disc recording apparatus (200). When the phase difference detection circuit detects a phase difference between an ATIP synchronization signal and a recording synchronization signal, this phase difference detection circuit activates an internal counter (271). Then, when phase difference information including a result of a counting operation performed by the internal counter is outputted from the phase difference detection circuit to the gain adjusting circuit, the gain adjusting circuit suitably adjust the frequency division ratio of a (1/N)-frequency-divider (242) according to the received phase difference information. Thus, the phase of a recording clock signal to be supplied from a PLL circuit (240) to a data encoder (260) through a frequency divider (250) is controlled.

Abstract: A system and method of drawing a visible image on an optical disk are provided. The optical disk is rotated while a optical pickup irradiates a laser beam onto the optical disk to draw the visible image on the optical disk. The rotating state of the optical disk is detected. The optical pickup is fed in a radial direction of the optical disk. An irradiating position of the laser beam is controlled relative to the optical disk by fixing the laser beam in the radial direction of the optical disk during one rotation of the optical disk, and shifting the irradiating position of the laser beam by a first distance in the radial direction each time one rotation of the optical disk is detected. The optical pickup is fed in the radial direction by a second distance the optical disk has rotated a predetermined number of rotations.

Abstract: An optical disk apparatus records information by irradiating a laser beam from a pickup onto an optical disk. A scanning section scans the laser beam relative to the optical disk. A recording control section controls the scanning section to effect recording of information. A drawing control section is provided for controlling the pickup and the scanning section to effect drawing of a visible image on the optical disk according to image information, such that the laser beam is changed between a first intensity incapable of acting on the optical disk and a second intensity capable of acting on the optical disk. A servo section periodically detects the laser beam reflected back from the optical disk when the laser beam has the first intensity, and servo-controls the irradiating of the laser beam during the drawing of the visible image based on the detection of the laser beam.

Abstract: An optical disk recording and reproducing apparatus operates in a read mode for controlling a laser driver to maintain a laser power at a target read level so as to read a signal from an optical disk, and operates in a write mode for controlling the laser driver to alternate the laser power between a target write level and a target bottom level comparative with the target read level so as to write a signal into the optical disk. In the write mode, a value obtained by sampling and holding the bottom level is set as the target value of a bottom level, and a bottom level control signal is outputted according to a difference between this target value and the detected value of the bottom level. Thus, the laser power control can be performed without any errors being generated even if an offset has occurred in the detected bottom power. Thus, the bottom laser power can be maintained constant.

Abstract: An optical disk recording apparatus operates in a write mode for controlling a laser driver to alternate a laser power between a target write level and a target bottom level so as to write a signal at a constant density into an optical disk which is rotated at a constant angular velocity. A controller operates in the write mode for outputting a bottom level control signal according to a difference between an actual bottom level and the target bottom level.

Abstract: An optical disk apparatus records information by irradiating a laser beam from a pickup onto an optical disk. A scanning section scans the laser beam relative to the optical disk. A recording control section controls the scanning section to effect recording of information. A drawing control section is provided for controlling the pickup and the scanning section to effect drawing of a visible image on the optical disk according to image information, such that the laser beam is changed between a first intensity incapable of acting on the optical disk and a second intensity capable of acting on the optical disk. A servo section periodically detects the laser beam reflected back from the optical disk when the laser beam has the first intensity, and servo-controls the irradiating of the laser beam during the drawing of the visible image based on the detection of the laser beam.

Abstract: A phase difference detection circuit (270) and a gain adjusting circuit (280) are provided in an optical disc recording apparatus (200). When the phase difference detection circuit detects a phase difference between an ATIP synchronization signal and a recording synchronization signal, this phase difference detection circuit activates an internal counter (271). Then, when phase difference information including a result of a counting operation performed by the internal counter is outputted from the phase difference detection circuit to the gain adjusting circuit, the gain adjusting circuit suitably adjust the frequency division ratio of a (1/N)-frequency-divider (242) according to the received phase difference information. Thus, the phase of a recording clock signal to be supplied from a PLL circuit (240) to a data encoder (260) through a frequency divider (250) is controlled.

Abstract: An optical disk recording and reproducing apparatus operates in a read mode for controlling a laser driver to maintain a laser power at a target read level so as to read a signal from an optical disk, and operates in a write mode for controlling the laser driver to alternate the laser power between a target write level and a target bottom level comparative with the target read level so as to write a signal into the optical disk. In the write mode, a value obtained by sampling and holding the bottom level is set as the target value of a bottom level, and a bottom level control signal is outputted according to a difference between this target value and the detected value of the bottom level. Thus, the laser power control can be performed without any errors being generated even if an offset has occurred in the detected bottom power. Thus, the bottom laser power can be maintained constant.

Abstract: An optical disk recording apparatus operates in a write mode for controlling a laser driver to alternate a laser power between a target write level and a target bottom level so as to write a signal at a constant density into an optical disk which is rotated at a constant angular velocity. A controller operates in the write mode for outputting a bottom level control signal according to a difference between an actual bottom level and the target bottom level.

Abstract: EFM input signal is received via an EFM input interface. Recording-timing adjustment data is received via a computer interface from a computer and stored in a register. To obtain EFM output signal having its pulse duration controlled on the basis of the EFM input signal and the record-timing adjustment data, there are further provided a clock signal generation circuit for generating clock signal by a phase-locked-loop arrangement based on a crystal oscillator, a first pair of counter and comparator driven by the clock signal to determine the pulse duration of a signal to be written, a second pair of counter and comparator that is driven by the clock signal and responsive to the output from the comparator of the first pair to start counting so as to determine a pulse duration to be adjusted, and a flip flop that is reset by the output from the comparator to provide an EFM output signal having a controlled pulse duration.

Abstract: A system and method for minimizing time-base fluctuations in playing back an electrocardiogram recorded on one track of a multi-track magnetic tape with reference clock signals recorded on another track. A sampling circuit samples the recorded electrocardiogram in response to sampling pulses produced in response to the recorded reference clock signals, and the sampled electrocardiogram is stored in a memory. The stored signal is then read in response to timing pulses produced by a generator. The phase difference between the sampling and timing pulses is detected and maintained constant.