CN1329888C - Optical disc drive system with constant angular speed for recording - Google Patents

Abstract

The invention provides a CD-ROM drive system, which is used for carrying out the recording work of a CD when the CD rotates at the same angular speed, and comprises a phase-locked loop, a phase-locked loop and a phase-locked loop, wherein the phase-locked loop is used for extracting the carrier frequency of a disturbance signal output by an optical read-write head; a clock synthesizer for generating a channel clock in accordance with the constant angular velocity operation according to the carrier frequency and the speed of rotation of an axial motor; a data encoder for encoding data inputted to the data encoder according to the channel clock to generate a data signal; and an optical pickup drive circuit for controlling the optical pickup to burn the optical disc according to the data signal.

Description

Optical disc drive system with constant angular speed for recording

technical field

The invention relates to an optical disc drive system, in particular to an optical disc drive system for constant angular velocity burning.

Background technique

Due to its low price, light size and weight, it can store a large amount of data, and has become one of the most commonly used data storage media in the modern information society. In particular, the research and development of writable optical discs allows users to write personal data into optical discs according to individual needs, making optical discs one of the most important portable personal storage media. How to make data access to writable optical discs more reliable and efficient has also become the focus of research and development in the modern information industry. However, the speed of the current CD burning machine is constantly increasing, and the speed has already increased by 30 to 40 times from the double speed when it was first developed. However, under high-speed burning, many problems will occur immediately.

When burning a CD-R or CD-RW disc, it is necessary to write data at an equal density, that is, the amount of written data per unit length must meet the specified value. So far, the writing method of CD-R or CD-RW burning machine is constant linear velocity writing mode (constant linear velocity); that is to control the axis motor (spindle motor), so that the optical read head relative to the disc The linear velocity of the chip is a fixed value, and the data is written into the disc with a fixed frequency relative to its linear velocity. But in view of the development of optical disc drives to high speed, the linear speed will be limited by the motor speed limit.

Therefore, another derived constant linear velocity is used in the current technology to enter high-speed operation. This technology is called zone-type constant linear velocity (Zone-CLV). That is, the disc is divided into several areas, and each area is assigned a certain linear speed double speed, and the double speed value increases from the inside to the outside. However, whenever a region with a different multiplier speed is crossed, the writing must be stopped, and the data will be written again when the axis motor is controlled to reach another fixed linear speed. During this process, the axis motor needs to be precisely controlled, and the technology of continuous writing is also a subject that is not easy to achieve.

Contents of the invention

Therefore, the main purpose of the present invention is to provide a set for burning optical discs in a constant angular velocity mode, so as to overcome the shortcomings of the high-speed optical disc burners in the prior art that are limited by the motor speed and the accuracy of the control circuit.

The present invention provides an optical disc drive system for burning an optical disc when the optical disc rotates at a constant angular velocity. The optical disc drive system includes a shaft motor for rotating the optical disc at a fixed rotational speed. ; An optical read-write head, used to access the data of the optical disc to generate a disturbance signal (wobble signal); a phase-locked loop, used to extract the carrier frequency of the disturbance signal from the disturbance signal output by the optical read-write head; A clock synthesizer (clock synthesizer), electrically connected to the phase-locked loop, is used to generate a channel clock (channelclock) conforming to constant angular velocity operation according to the carrier frequency output by the phase-locked loop; a data encoder is used to generate a channel clock according to the The channel clock output by the clock synthesizer encodes the data input to the data encoder to generate a data signal; and an optical read-write head drive circuit is connected to the optical read-write head for burning according to the optical disc drive system The write strategy and the data signal output by the data encoder control the optical read-write head to burn the optical disc.

Description of drawings

FIG. 1 is a schematic diagram of an optical disc drive system in the present invention.

Detailed ways

Please refer to FIG. 1 . FIG. 1 is a schematic diagram of an optical disc drive system 2 in the present invention. The CD player system 2 includes a master control terminal 4 , a first circuit 10 , a second circuit 40 , a third circuit 70 , a shaft motor 82 and a laser read/write head 84 . The second circuit 40 is used to drive the motor with a fixed frequency, and the first circuit 10 transmits the channel clock corresponding to the linear speed of the optical disc drive to the data encoder 72 in the third circuit 70 . The data encoder 72 is used to encode the external data from the master terminal 4 into a data type that can be burned by the optical disk drive system 2 according to the channel clock.

Please refer to the first circuit 10 in FIG. 1 again; the first circuit 10 includes a preamplifier 12 , a phase-locked loop 14 and a frequency synthesizer 16 . The pre-amplifier 12 is used to amplify the jitter signal from the laser head 84 for subsequent processing; and the jitter signal is then input into the phase-locked loop 14 . The jitter signal is a divergent spiral signal, which is an absolute time signal (ATIP, Absolute Time In Pre-groove) stored on the optical disc in the form of a frequency shift key. Also therefore, the carrier frequency of the dithering signal can be extracted by sending the signal into the phase-locked loop 14; the frequency is 22.05*n KHz, where n represents the linear multiplier speed of the optical disc drive, which can be a non-integer. And this data is sent into frequency synthesizer 16 immediately, purpose is to make frequency synthesizer 16 can produce the channel clock of 4.3218*n MHz; The n of this channel clock is identical with the n of dithering signal carrier frequency, and this channel clock is as above As mentioned above, it is used by the data encoder 72 as a reference clock when the data encoder 72 encodes, and it is also an important key to the medium angular velocity calculation of the present invention. Since the multiple speed n in the constant angular velocity operation will change with the displacement of the laser head 84, the channel clock constantly updated in real time will ensure that the data generated by the data encoder 72 can be correctly written into the optical disc.

Please refer to the second circuit 40 of Fig. 1 again; The second circuit 40 comprises a frequency generator 42 (frequency generator), a frequency comparator 44 (frequency comparator), a frequency divider 46 (frequency divider), a crystal oscillator 48 , a motor driving circuit 54 , a calculator 50 and a low-pass filter 52 . The frequency generator 42 is electrically connected to the shaft motor 82. The shaft motor 82 generates six pulses per revolution, and the frequency generator 42 generates a corresponding first signal as the rotation speed of the shaft motor 82 changes. Simultaneously, the quartz oscillator 48 produces a fixed frequency, which is then sent into the middle of the frequency divider 46 to generate a second signal, and the frequency of the second signal is the rotation frequency of the expected medium angular velocity operation; the second signal and the first signal are sent into Compare among the frequency comparator 44, the comparator 44 can send the comparison result of two signal frequencies to the calculator 50 of next stage to do processing; to the motor drive circuit 54 . The motor drive circuit 54 accelerates or decelerates the shaft motor 82 according to the input signal. This means that if the frequency of the second signal generated by the frequency divider 46, that is, the predetermined frequency corresponding to the axis motor 82 is higher than the current rotation frequency of the axis motor 82, the motor drive circuit 54 will accelerate the axis motor 82 On the contrary, the motor drive circuit 54 will slow down the rotational speed of the axial motor 82 .

Please refer to the third circuit 70 in FIG. 1 again; the third circuit 70 includes a data encoder 72 , a hardware 74 and a laser head drive circuit 76 . The data encoder 72 is electrically connected to the main control terminal 4 and the frequency synthesizer 16 of the first circuit 10, and it will continuously obtain the latest channel clock from the frequency synthesizer 16, so the data encoder 72 can constantly use the latest channel clock To encode the data input by the master control terminal 4 . The encoded data will be converted into an appropriate pulse train according to the data stored in the hardware 74, and the laser head 84 will be controlled by controlling the opening and closing of the laser head drive circuit 76. The operation of writing to the optical disc 86 is performed.

When the CD player system 2 is operating at a constant angular velocity, since the shaft motor 82 can be maintained at the same rotational speed, it does not need to be accelerated or decelerated according to the difference in the radius of rotation, thus greatly reducing the effort required to control the shaft motor 82 Accuracy, and this is also a major limitation of the axial motor 82 running at constant linear velocity. In addition, the burning speed of the optical disc player system 2 will also be able to maintain the highest speed because the shaft motor 82 can always maintain the highest burning efficiency.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the patent of the present invention.

Claims (8)

1. An optical disc drive system, which is used to burn the optical disc when the optical disc rotates at a constant angular velocity. The optical disc drive system includes: an axial motor for rotating the optical disc at a fixed rotational speed; An optical read-write head, used to access the data of the optical disc to generate a disturbance signal; A phase-locked loop, used to extract the carrier frequency of the disturbance signal from the disturbance signal output by the optical read-write head; A clock synthesizer, electrically connected to the phase-locked loop, used to generate a channel clock conforming to constant angular velocity operation according to the carrier frequency output by the phase-locked loop; a data encoder, used to encode the data input to the data encoder according to the channel clock output by the clock synthesizer to generate a data signal; and An optical read-write head drive circuit, connected to the optical read-write head, used to control the optical read-write head to burn the optical disc according to the burning parameters of the optical disc drive system and the data signal output by the data encoder; a frequency generator connected to the shaft motor for generating a first signal according to the rotation speed of the shaft motor; a quartz oscillator for generating a fixed clock; A frequency divider, connected to the crystal oscillator, is used to divide the input fixed clock to generate a second signal; a frequency comparator, connected to the frequency generator and the frequency divider, for comparing the first and second signals to generate a control signal; and A motor drive circuit is used to drive the axis motor to rotate the optical disc according to the control signal. 2. The optical disc drive system according to claim 1, further comprising a pre-amplifier connected to the optical pickup and the phase-locked loop for amplifying the disturbance signal output by the optical pickup . 3. The optical disc player system as claimed in claim 1, wherein it is an optical disc burner. 4. The optical disk drive system as claimed in claim 1, wherein the optical pickup is a laser pickup. 5. A method for making an optical disc drive system perform burning work when an optical disc rotates at a constant angular velocity, the method comprising: providing an axial motor for rotating the optical disc at a fixed rotational speed; providing an optical read/write head for accessing the data of the optical disc to generate a disturbance signal; providing a phase-locked loop for extracting the carrier frequency of the disturbance signal from the disturbance signal output by the optical read-write head; A clock synthesizer is provided, which is electrically connected to the phase-locked loop, and is used to generate a channel clock conforming to constant angular velocity operation according to the carrier frequency output by the phase-locked loop; providing a data encoder for encoding the data input to the data encoder according to the channel clock output by the clock synthesizer to generate a data signal; and Provide an optical read-write head drive circuit, connected to the optical read-write head, used to control the optical read-write head to burn the optical disc according to the burning parameters of the optical disc drive system and the data signal output by the data encoder; providing a frequency generator connected to the shaft motor for generating a first signal according to the rotation speed of the shaft motor; Provide a crystal oscillator for generating a fixed clock; providing a frequency divider, connected to the crystal oscillator, used to divide the input fixed clock to generate a second signal; providing a frequency comparator, connected to the frequency generator and the frequency divider, for comparing the first and second signals to generate a control signal; and A motor drive circuit is provided for driving the shaft motor to rotate the optical disc according to the control signal. 6. The method according to claim 5, further comprising using a pre-amplifier connected to the optical pickup and the phase-locked loop for amplifying the disturbance signal output by the optical pickup. 7. The method of claim 5, wherein the optical disc drive system is an optical disc burner. 8. The optical disk drive system as claimed in claim 1, wherein the optical pickup is a laser pickup.