Circuit and method to prevent errors in recording

A circuit to prevent errors in recording in an optical recording and/or reproducing apparatus having a motor wherein data is recorded at a constant rate on a recording medium wobbled according to an input wobble signal having a predetermined frequency and is reproduced at a constant or a variable rate from the recording medium, the circuit comprising:

• a first detector to generate a detection pulse by determining whether a counted value, obtained by counting a number of cycles of the input wobble signal, using as a reference a system clock signal having a frequency higher than the predetermined frequency of the input wobble signal, is in a permissible range of a constant write rate;
• a second detector to generate a recording control signal to allow or prohibit a record operation after determining whether the detection pulse meets a predetermined lock condition or a predetermined unlock condition;
• a system clock generator to generate the system clock signal having the frequency higher than the predetermined frequency;
• a generator to generate a speed control signal required to control a rotation speed of the motor, by comparing a frequency of a frequency divided wobble clock signal and the frequency of the system clock signal, so that the rotation speed is at the constant rate to record and at the constant or the variable rate to reproduce;
• a selector to select one of the wobble clock signal and the system clock signal and to provide the selected signal as a write clock signal to the adaptive laser power controller;
• a wobble clock generator to generate a wobble clock signal using the input wobble signal;
• a wobble clock lock detector to determine whether the wobble clock signal is locked and to provide a wobble clock lock signal to the second detector;
• and
• a frequency divider to frequency divide the wobble clock signal and to provide the frequency divided signal to the first detector,
• wherein the optical recording and/or reproducing apparatus comprises:
• a high frequency amplifier to detect a reproducing signal and the input wobble signal having the predetermined frequency from a signal picked up from the recording medium by a pickup unit,
• a data processor to process the reproducing signal provided from the high frequency amplifier in a reproducing time and to process input data to record in a recording time,
• a servo controller to control the rotation speed of the motor, track servo and focus servo related to the rotation of the recording medium according to the reproducing signal related to the servo among reproducing signals provided from the data processor,
• an adaptive laser power controller to control a quantity of laser light so that a signal processed to record and provided from the data processor is stably recorded, and
• a microcomputer to allow or prohibit a recording operation according to the recording control signal, and to set the permissible range of the constant write rate, the predetermined lock condition and the predetermined unlock condition.