摘要:
Provided are a focus search apparatus and method for performing a focus search after moving an optical pickup to a focus-on point according to a signal output from a sine wave generator so that a stable and smooth focus search is performed. In the focus search method, a sine wave is generated in response to a focus search command. The focus search is performed using an optical pickup in response to the sine wave. The optical pickup is driven in response to an amplitude of the sine wave during the focus search and in response to a filtered focus error signal during a focus servo.
摘要:
Provided are an apparatus and method for detecting a type of an optical disc inserted into an optical disc system and/or adjusting a track balance in the optical disc system by detecting voltages of a focus error signal and a tracking error signal. For detecting a type of an optical disc inserted into an optical disc system, the apparatus comprising: an analog-to-digital converter that converts a focus error signal into n-bit voltage data; and a duty measurer that compares the n-bit voltage data with a positive noise voltage level and a negative noise voltage level, upcounts by a predetermined value if the n-bit voltage data is higher than the positive noise voltage level or lower than the negative voltage level, and outputs the upcounted result as a duty of the focus error signal.
摘要:
A brake signal generating circuit and method for improving the efficiency of a lens brake in an optical disc reproducing system are provided. The brake signal generating circuit includes: a brake signal generator which receives a mirror signal that detects the track movement of a main beam and generates a first brake signal or a second brake signal for selecting predetermined operation mode signals in response to a first brake selection signal; a first operation mode generator which generates a processing value of the gain and phase of a tracking error as a first operation mode signal in response to a predetermined first control signal; a second operation mode generator which generates a correction value of a tracking loop offset as a second operation mode signal in response to a second control signal; a third operation mode generator which generates a value obtained by multiplying a value of the first operation mode signal by a predetermined value K1, where K1 is a non-zero real number, as a third operation mode signal; a fourth operation mode generator which generates as a fourth operation mode signal a value obtained by subtracting the value of the first operation mode signal from a value of the second operation mode signal, multiplying the result of the subtraction by the predetermined value K1, and adding the value of the second operation mode signal to the product; a fifth operation mode generator which generates a predetermined reference voltage as a fifth operation mode signal; and a switch unit which outputs one of the first through fifth operation mode signals in response to the first or second brake signal and second through fourth brake selection signals. The amount of braking is inverted in accordance with the amount of error in a track deviation direction and multiplied by a gain factor to improve the brake efficiency. In addition, the settling time after a track jump is reduced, the data access can be faster, and the unstable state, for example, due to track skipping, can return to the original stable state quickly.
摘要:
Method and apparatus for controlling the light power of an optical disk system, and optical disk system having the same are provided. The optical disk system includes a microcontroller for controlling the operation of the optical disk system, a light power adjusting apparatus for generating a light quantity control signal for controlling the quantity of light emitted from the optical disk, and an optical pickup device for adjusting the quantity of light emitted from the optical disk in response to the light quantity control signal. The method includes the steps of converting E and F beam signals used for generating a tracking error signal into the form of voltage and synthesizing the converted E and F beam signals to obtain a tracking sum signal; maintaining the light power of the light emitting diode when the level of the tracking sum signal is the same as that of a reference signal; decreasing the light power of the light emitting diode, corresponding to the difference between the tracking sum signal and the reference signal, when the level of the travel sum signal is higher than that of the reference signal; and increasing the light power of the light emitting diode, corresponding to the difference between the tracking sum signal and the reference signal, when the level of the travel sum signal is lower than that of the reference signal. The progress of the method returns back to the stop of obtaining a tracking sum signal after increasing or decreasing the light power. Accordingly, the quantity of light reflected from the an optical disk can be constantly maintained.
摘要:
A method and an apparatus for precisely controlling the rotation speed of a spindle motor in an optical system according to a given condition are provided. The method involves counting in response to a clock signal widths of first and second logic states of an input signal, which varies with rotation speed of the spindle motor, when an operation control command is issued, comparing a predetermined reference value with a count value for one check cycle, and outputting the comparison result; and controlling the constant linear velocity of the spindle motor in response to the comparison result.
摘要:
An optical disk reading apparatus and method compensate for errors in the full period of an EFM signal. An RF amplifier converts an optical signal reflected from an optical disk into an analog electrical signal. A signal converter converts the analog signal into a digital signal which is modulated to provide an EFM signal. A full period compensating portion compensates for full period errors in the EFM signal and outputs the error compensated EFM signal. An error correcting portion corrects the errors of the compensated EFM signal using an error correction code. Image quality is improved by removing the full period errors.
摘要:
An apparatus and method for digitally detecting a tracking error signal using multiple phase clocks. The apparatus includes a phase extractor receiving four divided outputs in response to light reflected from an optical disk and extracting four divided phases, respectively, a phase difference detector detecting phase differences between two phases among the four divided phases, a multiple phase clock generator generating a plurality of phase clocks in response to a predetermined clock signal, a phase error detector counting phase differences in response to each of the plurality of phase clocks, summing the counted phase differences, and detecting a phase error, and a tracking error output unit detecting the tracking error signal in response to the phase error and outputting the detected tracking error signal.
摘要:
An apparatus for and a method of detecting a wobble signal in accordance with a time shift includes comparing a basic wobble signal with reference levels to detect pulses representing the time shift in an analog fashion, and digitally determining a code value for the basic wobble signal on the basis of the widths of the pulses using a channel clock signal and a wobble clock signal. The determined code value is accumulated and serves as a basis on which final wobble data is produced.
摘要:
An automatic gain controller includes a voltage control gain amplifier amplifying input signals in response to a control voltage and producing output signals. A level detector detects peak and bottom levels of the output signals of the voltage control gain amplifier, and an analog-digital converter (ADC) converts the detected peak and bottom levels into digital signals. A peak detector detects a digital peak in response to a difference between the digital peak level and digital bottom level, and a voltage controller compares the digital peak and a reference voltage, and controls the control voltage.
摘要:
An apparatus and method for digitally detecting a tracking error signal using multiple phase clocks. The apparatus includes a phase extractor receiving four divided outputs in response to light reflected from an optical disk and extracting four divided phases, respectively, a phase difference detector detecting phase differences between two phases among the four divided phases, a multiple phase clock generator generating a plurality of phase clocks in response to a predetermined clock signal, a phase error detector counting phase differences in response to each of the plurality of phase clocks, summing the counted phase differences, and detecting a phase error, and a tracking error output unit detecting the tracking error signal in response to the phase error and outputting the detected tracking error signal.