KR19990004486A - Method and apparatus for discriminating type of optical recording medium - Google Patents

Abstract

The present invention relates to a method for determining the type of optical recording medium and an apparatus thereof.

The method for determining the type of optical recording medium of the present invention includes a first step of setting the intensity of a light beam to be irradiated on the optical recording medium, a second step of detecting the intensity of the light beam reflected from the optical disc, and the detected reflected light beam. And a third step of determining the type of the optical recording medium by comparing the intensity and the intensity of the reference light beam.

Description

Method for determining type of optical recording medium and apparatus therefor

The present invention relates to a method for reproducing an optical recording medium and an apparatus thereof, and more particularly to a method for determining the type of an optical recording medium and an apparatus thereof.

At present, a read-only compact disc (hereinafter referred to as a CD), which is a kind of optical recording medium, is rapidly spreading. In addition, the demand for recordable compact discs (hereinafter referred to as CD-Rs) and rewritable discs (CD-RWs) is gradually increasing. The reflectances of the above optical recording media have different characteristics from each other. For example, the reflection of the CD is 70% or more, the CD-R is 65% or more, and the CD-RW is 15-25%. As a result, the current drive device with a multiread function is spurring research and development to determine various disk types and to have an optimal RF level. In particular, the drive unit of a CD-RW disc should support the use of a regular CD disc and a CD-R, CD-RW disc. The drive unit of a DVD-RAW disc should support a DVD-ROM disc and a regular CD, CD-R, CD. -RW discs must also be supported. However, the current multi-lead driver device cannot compensate for the change in the RF level according to the reflectance of the disk, which causes a bad regeneration characteristic during data reproduction.

A disc type classification method according to the prior art will be described with reference to FIG. 1.

1 is a flowchart illustrating a disk type discrimination method according to the prior art. The disk type discrimination method according to the prior art in the configuration of FIG. 1 includes an S1 step of turning on a laser diode (hereinafter referred to as LD); S2 step of setting lead power and S3 step of raising the lens. The LD is turned on because the APC (Auto Power Control; APC) circuit of the data player supplies the read power to the LD output.

After setting the initial lead power, the lens is raised by raising the actuator.

Also, the S4 step of determining whether or not FOK (Focus OK) is generated, and the lead power value of the disc set close to the lead power at that time after checking the lead power when FOK occurs, selects the type of optical disc. S5 step for discriminating, and S6 step for performing S2 step to S4 step by increasing lead power when FOK does not occur. The light beam projected from the LD reaches the disk surface via the lens, and when the light beam reflected from the disk surface is detected in the LD receiver, a FOK signal is generated. When the FOK signal is generated, the disc type determination is finished, and the current read power is checked to reproduce the data. On the other hand, if the initial read power setting is incorrect, the FOK signal is not generated. Therefore, the read power is increased to repeat the steps S2 to S4.

However, the above disc type discrimination method takes a long time to determine the disc, and the accurate lead power setting according to the sensitivity of the disc may be inaccurate, and the change of the RF level according to the reflectance of the disc may not be compensated. Therefore, it is pointed out that the regeneration characteristics worsen during data reproduction.

Accordingly, it is an object of the present invention to provide a method and apparatus for determining the type of optical recording medium which can improve the playback performance of a system by performing the focus search operation in the smallest number of times to speed up disc type determination.

In addition, another object of the present invention to provide a method and apparatus for adjusting the RF level that can improve the playback performance of the system can monitor the RF level (Adjust the exact RF level).

1 is a flowchart illustrating a type discrimination method of an optical recording medium according to the prior art.

2 shows the movement of the actuator.

3 is a step control waveform diagram of lead power;

4 is an RF waveform diagram according to the type of optical recording medium.

Fig. 5 is a block diagram of the type discriminating apparatus of the optical recording medium of the present invention.

Fig. 6 is a flowchart illustrating the type discrimination method of the optical recording medium of the present invention.

Explanation of symbols for the main parts of the drawings

2: control unit 4: digital-to-analog converter

6: LD driver 8: RF level meter

10: RF amplifier 12: optical recording medium

In order to achieve the above object, there is provided a method of determining the type of optical recording medium of the present invention, comprising: a first step of setting a lead power indicating an intensity of a light beam to be irradiated onto an optical recording medium; and detecting the intensity of the light beam reflected from the optical disc. And a third step of comparing the detected intensity of the reflected light beam with the intensity of the reference light beam to determine the type of the optical recording medium.

In addition, in order to achieve the above object, an apparatus for determining the type of optical recording medium of the present invention includes: a control unit for monitoring the high frequency signal level detected by the optical recording medium to set an appropriate lead power and to determine the type of the optical recording medium; A digital-to-analog converter for converting the digital lead power set by the controller to the analog lead power, and a lead-to-power converter connected to the digital-to-analog converter for switching from the digital-to-analog converter to drive the laser diode It is provided with a laser diode driver for.

In addition, in order to achieve the above object, the high frequency signal level adjusting method of the present invention comprises a first step of adjusting a lead power indicative of the intensity of a light beam to be irradiated to an optical recording medium; The second step of detecting the high frequency signal level, the third step of determining whether the high frequency signal level detected in the second step and the reference high frequency signal match, and the high frequency signal level and the reference high frequency signal level detected in the third step If not, a fourth step of adjusting the high frequency signal level by repeating the first to third steps.

In addition, in order to achieve the above object, the high frequency signal level adjusting apparatus of the present invention includes a high frequency signal amplifier for generating and amplifying a high frequency signal by receiving a light beam reflected from the surface of the optical recording medium, and a high frequency signal amplifier for A high frequency signal level meter unit for monitoring the level of the high frequency signal generated by the high frequency signal amplifier and a high frequency signal level meter to monitor the high frequency signal level to set an appropriate lead power and to adjust the high frequency signal level. It is provided with a control unit for the following.

Other objects and features of the present invention other than the above object will become apparent from the description of the embodiments with reference to the accompanying drawings.

With reference to Figures 2 to 6 will be described a preferred embodiment of the present invention.

FIG. 5 is a block diagram of a disk type discriminating apparatus according to the present invention. In the configuration of FIG. 5, the disk type discriminating apparatus according to the present invention receives a light beam reflected from the surface of the optical recording medium 12. An RF amplifier 10 for generating and amplifying an RF pattern, and an RF level connected to the RF amplifier 10 to convert the level of an analog RF signal generated by the RF amplifier 10 into a digital RF signal The meter unit 8 is provided. The RF amplifier 10 of the data player converts and reproduces the reproduced data from an optical beam into an electrical form (ie, an RF signal), and then amplifies the analog-to-digital converter (Analog-Digital Conveter) of the RF level meter unit 8. Output). The ADC converts the RF signal into a square wave by performing an analog-to-digital conversion of the RF signal. The waveform of the RF signal according to the type of optical recording medium detected by the RF amplifier 10 is shown in FIG.

In addition, the controller 2 is connected between the RF level meter unit 8 and a digital-analog converter (hereinafter referred to as DAC) to monitor the RF level and set an appropriate lead power, and the controller DAC 4 connected between (2) and LD driver 6 for converting the digital lead power set by the controller 2 into analog lead power, and connected to the DAC 4 to the DAC 4 An LD driver 6 for driving the LD by converting the converted lead power into LD is provided. The RF level signal of the RF level meter unit 8 is input to the controller 2 and feeds back to the controller 2 the result of the previous stage read power set by the controller 2. The controller 2 compares the RF level signal with the target RF signal and sets and outputs an appropriate read power according to the type of the disc. In addition, the DAC 4 converts the digital lead power transmitted from the control unit 2 into analog lead power and outputs it to the LD driver 6. At this time, the LD driving unit 6 drives the LD by switching the lead power converted into analog to LD.

6 is a diagram showing a flow chart of the method for discriminating the kind of the disk according to the present invention.

After the LD is turned on, the lens is raised (steps S11 to S12). The LD driver 6 turns on the LD to transmit the light beam to the surface of the optical recording medium, and at the same time, the actuator descends to the initial position. The lens is also lowered and then the lens is raised by raising the actuator. The movement of the actuator at this time is shown in FIG.

In step S13, the lead power is set. The initial lead power is set to have the reflectance and lead power of the CD-RW having the most reflectance. For example, the reflectivity of a CD-RW is 15-25%, and the lead power is about 1.0mW. The waveform of the lead power is a stepped waveform at intervals of ΔmW as shown in FIG. In step S14, it is determined whether the FOK signal is generated.

The FOK signal indicates that more than a certain amount of light is reflected on the disk. If the FOK signal does not occur in the step S14, after repeating the steps S13 to S14 for a predetermined time, if the FOK signal does not occur, it is determined that there is no optical recording medium and the data reproduction ends. Step) The initially set lead power is larger than the recording power of CD-R and general CD. For example, the lead power of a CD-R is 0.7 mW, and the lead power of a general CD is 0.5 mW. Therefore, the initial lead power has a sufficient amount of light to determine the presence or absence of the optical recording medium. In this state, the FOK signal does not occur, meaning that the optical recording medium is not mounted. However, after a predetermined time has passed after checking the generation of the FOK signal by setting the lead power for a predetermined time to maintain the stability of the system. It is determined that there is no optical recording medium and data reproduction is terminated. When the FOK signal is generated in step S14, the RF level meter is read. (S16 step) When the FOK signal is generated, the control unit 2 reads the RF level at that time from the RF level meter unit 8. In step S17, it is determined whether the target RF level matches the RF level read in step S16. The controller 2 compares the target RF level with the read RF level and determines whether the two data match each other. If the target RF level and the read RF level do not match in step S17, the steps S13 to S17 are repeated. (S18 step) The control unit 2 generates a read power ΔmW when the two data do not match. The RF level may be monitored by repeatedly repeating the steps S13 to S17 until the target RF level and the read RF level coincide with each other. If the target RF level and the read RF level match at step S17, the lead power at that time is checked to determine the type of disc and the RF level is adjusted (steps S19 to S21). The control unit 2 controls the target RF level. When the RF level and the read RF level coincide with each other, the type of the disc can be determined by the read power value at that time.

When the lead power value is 0.5 mW, the optical recording medium at that time is determined as a general compact disc (CD). When the lead power value is 0.7 mW, a compact disc (CD-R) capable of recording the optical recording medium at that time If the read power value is 1.0 mW, the optical recording medium at that time is determined as a rewritable compact disc (CD-RW). In step S22, it is determined whether wobble is formed from the information of the curved surface wobbled on the optical recording medium. If no wobble is formed in the optical recording medium in step S22, the optical recording medium at this time is determined to be a CD. (S23 step) When the wobble is formed in the optical recording medium in step S22, it is determined whether data is to be repeatedly recorded from the special information of the ATIP (Absolute Time In Pregroove) of the optical recording medium. In the case where the data is not repeatedly recorded in the step S24, the optical recording medium is determined as CD-R. In the case where the data is repeatedly recorded in the S24 step, the optical recording medium is determined as the CD-RW. do. (S25 step to S26 step)

As described above, the disc type discrimination / RF level adjusting method and the apparatus of the present invention can perform the focus search operation in the smallest number of times to quickly determine the disc type, and monitor the RF level to accurately measure the RF. By adjusting the level, you can reliably support the multilead function of the optical disc drive unit.

It has the advantage of improving performance.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (13)

A method of determining the type of optical recording medium for reproducing information of an optical recording medium, comprising: a first step of setting an intensity of a light beam to be irradiated on the optical recording medium; A second step of detecting the intensity of the light beam reflected from the optical disc; And determining the type of the optical recording medium by comparing the detected intensity of the reflected light beam with the intensity of the reference light beam. The method of claim 1, further comprising repeating the first to third steps when the intensity of the reflected light beam detected in the third step does not match the intensity of the reference light beam. A method for determining the type of optical recording medium. 2. The method of claim 1, wherein after determining the type of the optical recording medium by comparing the intensity of the reflected light beam with the intensity of the reference light beam in the third step, whether the wobble is formed from information on the wobbled curved surface of the optical recording medium. And determining the type of optical recording medium. 4. The method of claim 3, further comprising the step of discriminating the optical recording medium as a compact disc (CD) when the wobble is not formed in the optical recording medium in the step of determining whether the wobble is formed. A method of determining the type of optical recording medium to be used. The method of claim 4, further comprising determining whether data is to be repeatedly recorded from the special information stored in the groove of the optical recording medium when the wobble is formed on the optical recording medium in determining whether the wobble is formed. A method for discriminating the type of optical recording medium. A compact disc (CD-R) capable of recording an optical recording medium at this time when data is not repeatedly recorded on the optical recording medium in the step of determining whether the optical recording medium is to be repeatedly recorded. Judging by; Determining whether the optical recording medium is to be rewritable, if the data is repeatedly recorded on the optical recording medium, and determining the optical recording medium as a rewritable compact disc (CD-RW). A method for discriminating the type of optical recording medium. The radio frequency signal according to claim 1, wherein the third step of determining the type of the optical recording medium comprises converting the intensity of the reflected light beam into a high frequency signal level at that time and converting the intensity of a reference light beam into a reference high frequency signal level. Determining whether the level coincides with the reference high frequency signal level; And determining the type of the optical recording medium by the read power value indicating the intensity of the light beam when the high frequency signal level and the reference high frequency signal level coincide with each other. 8. The method of claim 7, wherein the step of determining the type of the optical recording medium comprises: determining the optical recording medium at that time as a general compact disc (CD) when the read power value is 0.5 mW; When the lead power value is 0.7 mW, discriminating the optical recording medium at that time as a recordable compact disc (CD-R); And determining the optical recording medium as a rewritable compact disc (CD-RW) when the read power value is 1.0 mW. An apparatus for determining the type of an optical recording medium for reproducing information of an optical recording medium, comprising: monitoring a high frequency signal level detected by the optical recording medium to appropriately set a lead power value indicating an intensity of a light beam to be irradiated onto the optical recording medium. A control unit for determining the type of optical recording medium; A digital-to-analog converter connected to the control unit for converting the digital lead power set by the control unit into analog lead power; And a laser diode driver connected to the digital-analog converter for converting and driving the lead power converted by the digital-analog converter into a laser diode. A method of forming a high frequency signal level for reproducing information of an optical recording medium, comprising: a first step of adjusting a read power value indicating an intensity of a light beam to be irradiated onto the optical recording medium; from a light beam reflected from the optical recording medium; Detecting a high frequency signal level at that time; A third step of determining whether the high frequency signal level detected in the second step and the reference high frequency signal match each other; And a fourth step of adjusting the high frequency signal level by repeating the first to third steps when the high frequency signal level detected in the third step and the reference high frequency preference level do not coincide with each other. How to adjust signal level. The method of claim 10, wherein the second step of detecting a high frequency signal level from the reflected light beam comprises: converting the light beam reflected from the surface of the optical recording medium into a high frequency signal; converting the high frequency signal into an analog-digital conversion; And detecting the high frequency signal level. A high frequency signal level adjusting apparatus for reproducing information of an optical recording medium, comprising: a high frequency signal amplifier for generating and amplifying a high frequency signal by receiving a light beam reflected from a surface of the optical recording medium; A high frequency signal level meter unit connected to the high frequency signal amplifier to monitor a level of the high frequency signal generated by the high frequency signal amplifier; And a control unit connected to the high frequency signal level meter to monitor a high frequency signal level to set an appropriate lead power and to adjust a high frequency signal level. The apparatus of claim 12, wherein the high frequency signal level meter unit comprises an analog-digital converter for converting a high frequency signal into a square wave by performing analog-to-digital conversion on the high frequency signal generated by the high frequency signal amplifying unit. High frequency signal level adjuster.