JP4831237B2 - Optical disk drive and optical disk determination method - Google Patents

Description

  The present invention relates to an optical disc drive in which an optical disc such as a DVD-RW, a DVD + RW, a DVD-ROM or the like is mounted and a disc determination method therefor. Specifically, a plurality of frequency components corresponding to the groove wobble frequencies of a plurality of types of optical discs that can be recorded are extracted from signals corresponding to the groove wobble reproduced from the mounted optical disc, and the extracted plurality of frequency components are extracted. Based on this, it is determined whether or not the mounted optical disc is a recordable optical disc by determining whether or not the mounted optical disc is a recordable optical disc. This relates to the optical disk drive and the like.

  As DVD-type optical discs, there are recordable optical discs such as DVD-RW discs and DVD + RW discs, and there are read-only optical discs such as DVD-ROM discs. These DVD optical disks have a diameter of 12 cm and the same outer shape. As DVD-type optical disk drives, there are an optical disk recording / reproducing apparatus that performs recording and reproduction and an optical disk reproducing apparatus that performs only reproduction.

  There has also been proposed a disc discriminating device capable of discriminating four types of optical discs of CD, CD-R, DVD, and DVD-R with a single recording / reproducing device (see, for example, Patent Document 1). . The disc discriminating apparatus described in Patent Document 1 is an old generation optical disc, but includes two comparison circuits. When the disc to be discriminated is a CD-R when rotation control is performed at a CD-R linear velocity, 2 The output signals from one comparison circuit are both H level signals, but if the disc to be discriminated is a DVD-R, one comparison circuit will output an H level signal and the other comparison circuit will output an L level signal. I have to. The disc is discriminated by the pattern of the output signal level from the two comparison circuits.

JP 09-198779 A

  As described above, since the DVD-type optical disc has the same outer shape, several types of optical discs having different characteristics and the like are mounted on the above-described DVD-type optical disc recording / playback apparatus and optical disc playback apparatus. Therefore, the apparatus side needs to determine the mounted optical disk and handle the mounted optical disk based on the determination result.

  For example, if a recordable optical disc recorded with a copy-prohibited digital video signal ignoring copy-prohibition is installed, it is determined that the optical disc is a recordable optical disc and is recorded from the optical disc. The digital video signal is not reproduced.

  Therefore, an object of the present invention is to provide an optical disk drive or the like that can determine whether or not the loaded optical disk is a recordable optical disk in a short time.

  In order to solve the above-described problems and achieve the object of the present invention, the optical disk drive of the present invention has a groove wobble from a predetermined position in the radial direction of the optical disk in a state where the loaded optical disk is rotated at a predetermined rotation speed. Wobble signal reproducing means for reproducing the corresponding signal, and a plurality of filter means for extracting a plurality of frequency components corresponding to the frequency of the groove wobble of a plurality of types of recordable optical discs from the output signal of the wobble signal reproducing means, Detection means for detecting the frequency level of the output signals of the plurality of filter means and disk discriminating means for discriminating the mounted optical disc using the detection signals of the detection means.

  The detecting means detects the frequency level of the reference signal based on the output signals of the plurality of PLL circuit units to which the output signals of the plurality of filter means are respectively supplied as reference signals, and the reference signal detected by the detecting means When the frequency level is within the first range, the disc discriminating unit discriminates that the loaded optical disc is the first optical disc. In addition, when the frequency level of the reference signal detected by the detection unit is within the second range of frequencies, the disc determination unit determines that the loaded optical disc is the second optical disc. When the frequency level of the reference signal detected by the detection means is neither the frequency in the first range nor the frequency in the second range, the disk discrimination means uses the third optical disk as the loaded optical disk. Determine that there is.

  The optical disc discrimination method of the present invention includes a step of reproducing a signal corresponding to the groove wobble from a predetermined position in the radial direction of the optical disc in a state where the loaded optical disc is rotated at a predetermined rotational speed, Extracting a plurality of frequency components corresponding to the groove wobble frequencies of a plurality of types of recordable optical discs from the recorded signal, and detecting a frequency level output in the step of extracting the plurality of frequency components, And a step of discriminating the mounted optical disk using the detected frequency level.

  If the detected frequency level is in the first range, it is determined that the loaded optical disc is the first optical disc, and the detected frequency level is in the second range. In some cases, it is determined that the mounted optical disk is the second optical disk. Further, when the detected frequency level is neither the frequency in the first range nor the frequency in the second range, it is determined that the mounted optical disk is the third optical disk.

  In the present invention, it is possible to mount a plurality of types of recordable optical discs and a read-only optical disc. When a recordable optical disc of a certain type is loaded, the signal corresponding to the reproduced groove wobble has a high level of the frequency component corresponding to the frequency of the groove wobble of the optical disc.

  For example, when an optical disk is driven to rotate at 1389 rpm and a signal is obtained by reproducing the position of a radius of 24 mm of the optical disk, the signal has a frequency component of about 140 kHz when a DVD-RW disk is mounted. When the DVD + RW disc is mounted, the level of the frequency component of about 810 kHz becomes large.

  A plurality of frequency components corresponding to the frequency of the groove wobble of a plurality of types of recordable optical discs are extracted from the signal corresponding to the groove wobble reproduced in this way. For example, when the plural types of recordable optical discs are DVD-RW discs and DVD + RW discs, a frequency component of about 140 kHz and a frequency component of about 810 kHz are extracted.

  Then, based on the plurality of extracted frequency components, it is determined whether or not the mounted optical disc is a recordable optical disc. In this case, when the level of any one of the plurality of frequency components is high, it can be seen that a recordable optical disc corresponding to the frequency component is loaded. Further, when none of the levels of the plurality of frequency components is high, it can be understood that none of the plural types of recordable optical disks is loaded.

  In this way, a plurality of frequency components corresponding to the groove wobble frequencies of a plurality of types of optical discs that can be recorded are extracted from a signal corresponding to the groove wobble reproduced from the mounted optical disc, and the plurality of extracted frequency components Based on the above, it can be determined in a short time and reliably whether or not the mounted optical disk is a recordable optical disk by determining whether or not the mounted optical disk is a recordable optical disk It becomes.

  According to the present invention, a plurality of frequency components corresponding to the frequency of the groove wobble of a plurality of types of optical discs that can be recorded are extracted from a signal corresponding to the groove wobble reproduced from the mounted optical disc, and a plurality of extracted plurality of frequency components are extracted. Based on the frequency component, it is determined whether or not the mounted optical disk is a recordable optical disk, and it can be determined in a short time and reliably whether or not the mounted optical disk is a recordable optical disk. .

It is a block diagram which shows the structure of a part of optical disk drive. It is a figure for demonstrating creation of a push pull signal. It is a block diagram which shows the structure of a wobble detection part. It is a figure which shows the output signal of a band pass filter at the time of mounting of each disc of DVD-RW, DVD + RW, and DVD-ROM. It is a block diagram which shows the other structure of a wobble detection part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a part of an optical disc drive 100 in which a DVD type optical disc can be mounted.

  The drive 100 includes a spindle motor 102 for rotationally driving a mounted optical disk 101, an optical pickup 103 including a semiconductor laser, an objective lens, a photodetector, and the like, and the optical pickup 103 is arranged in the radial direction (radial direction) of the optical disk 101. And a feed motor 104 for moving to (). In this case, the laser beam from the semiconductor laser that constitutes the optical pickup 103 is irradiated on the recording surface of the optical disc 101, and the reflected light (returned light) is irradiated on the photodetector that constitutes the optical pickup 103.

  The drive 100 also includes a controller 105 that controls the operation of the entire drive and a servo controller 106. The controller 105 is connected to a display unit 107 constituted by a liquid crystal display element and an operation key unit 108 provided with a plurality of operation keys. The servo controller 106 controls tracking and focus in the optical pickup 103 and controls the operation of the feed motor 104. Further, the servo controller 106 controls the rotation of the spindle motor 102, and the optical disk 101 is rotationally driven by CLV (Constant Linear Velocity) during recording and reproduction.

Further, the drive 100 processes an output signal of a photodetector constituting the optical pickup 103 to generate a reproduction RF signal S _RF , a focus error signal S _FE , a tracking error signal S _TE and a push-pull signal S _PP. have. Here, the focus error signal _SFE is created by the stigma method (astigmatism method). The tracking error signal _STE is created by the DPD method (phase difference method) during reproduction, and is created by the push-pull method during recording.

The focus error signal S _FE and the tracking error signal S _TE which are created by the RF amplifier 109 as is supplied to the servo controller 106, the servo controller 106, using these error signals, the optical pickup as described above The tracking and focus at 103 are controlled.

Here, as shown in FIG. 2 , a four-divided photodetector PD is used as the photodetector constituting the optical pickup 103. On this photodetector PD, a spot SP is formed by the return light from the optical disk 101. When the detection signal of the four photodiodes Da~Dd constituting the photodetector PD and Sa to Sd, the push-pull signal S _PP is obtained by the following calculation.

That is, the detection signals Sa and Sc are added by the adder 111 and the detection signals Sb and Sd are added by the adder 112. Then, the subtracter 113 subtracts the output signal of the adder 112 from the output signal of the adder 111 to obtain the push-pull signal _SPP .

  Returning to FIG. 1, the drive 100 also performs a series of analog signal processing such as binarized slices of the reproduction RF signal created by the RF amplifier unit 109 and subsequent generation of synchronization data by a PLL (Phase-Locked Loop). And a demodulation / ECC unit 109 that performs processing such as demodulation of the synchronization data (8/16 modulated data) generated by the read channel unit 108 and subsequent error correction. The output data of the demodulation / ECC unit 109 is supplied to a reproduction data processing system (not shown).

Further, the drive 100 transfers address information extracted by the read channel unit 115 from the reproduction RF signal _SRF to the controller 105, or processes the push-pull signal _SPP to obtain address information. The address processing unit 117 for transferring to the address 105 is provided.

The drive 100 includes a wobble detector 118 for detecting a wobble signal from the push-pull signal S _PP created by the RF amplifier unit 109. FIG. 3 shows the configuration of the wobble detection unit 118.

  The wobble detection unit 118 includes a bandpass filter 121 having a center frequency f1 of 140 kHz and a bandpass filter 122 having a center frequency f2 of 810 kHz.

When the optical disc 101 is a DVD-RW disc, when this optical disc 101 is driven to rotate at 1389 rpm, the frequency of the groove wobble at the radius of 24 mm of the optical disc 101 is about 140 kHz. Accordingly, the push-pull signal S _PP in this case, the level of frequency component of about 140kHz becomes large.

When the optical disc 101 is a DVD + RW disc, when the optical disc 101 is driven to rotate at 1389 rpm, the frequency of the groove wobble at a position of a radius of 24 mm of the optical disc 101 is about 810 kHz. Accordingly, the push-pull signal S _PP in this case, the level of frequency component of about 810kHz becomes large.

  The wobble detection unit 118 includes a level detection unit 123 that detects the amplitude level of the output signal SF1 of the bandpass filter 121, and a level detection unit 124 that detects the amplitude level of the output signal SF2 of the bandpass filter 122. ing. These level detectors 123 and 124 are constituted by, for example, a rectifying / smoothing circuit.

  The wobble detection unit 118 samples the output signal of the level detection unit 123 with a sample pulse SMP supplied from the controller 105 at a predetermined timing, and holds the sample value as a detection level LV1, A sample hold circuit 126 that samples the output signal of the level detection unit 124 with the above-described sample pulse SMP and holds the sample value as the detection level LV2.

  The wobble detection unit 118 converts the detection level LV1 held by the sample hold circuit 125 into a digital signal and supplies it to the controller 105, and the detection level LV2 held by the sample hold circuit 126. And an A / D converter 128 that converts the digital signal and supplies it to the controller 105.

  A disc determination operation in the optical disc drive 100 shown in FIG. 1 will be described. When the optical disk 101 is loaded, the controller 105 determines whether the optical disk 101 is a recordable disk, that is, a DVD-RW disk or a DVD + RW disk, or a reproduction-only disk, that is, a DVD-ROM disk. judge.

In this case, the controller 105 controls the servo controller 106, moves the optical pickup 103 to a position with a radius of 24 mm, rotates the optical disk 101 at 1389 rpm, causes the optical pickup 103 to emit a laser beam from the semiconductor laser, and further focuses And tracking servo. In this state, the push-pull signal S _PP to be created by the RF amplifier 109 is supplied to the wobble detecting section 118 (see FIG. 2). In the wobble detection unit 118, the push-pull signal _SPP is processed to generate detection levels LV1 and LV2, and the detection levels LV1 and LV2 are supplied to the controller 105.

That is, from the push-pull signal S _PP, the band-pass filter 121, the frequency component of about 140kHz is extracted. Then, the amplitude level of the output signal SF1 of the filter 121 is detected by the level detection unit 123, and the output signal of the level detection unit 123 is sampled by the sample hold circuit 125 to obtain the detection level LV1. The detection level LV 1 is converted into a digital signal by the A / D converter 127 and supplied to the controller 105.

Similarly, a frequency component of about 810 kHz is extracted from the push-pull signal _SPP by the band pass filter 122. The amplitude level of the output signal SF2 of the filter 122 is detected by the level detection unit 124, and the output signal of the level detection unit 124 is further sampled by the sample hold circuit 126 to obtain a detection level LV2. This detection level LV 2 is converted into a digital signal by the A / D converter 128 and supplied to the controller 105.

  In the controller 105, the mounted optical disc 101 is determined as follows using the detection levels LV1 and LV2. That is, when LV1> LV2 and LV1 is equal to or higher than a specified level, it is determined that the mounted optical disc 101 is a DVD-RW disc that is a recordable disc. Further, when LV2> LV1 and LV2 is equal to or higher than a specified level, it is determined that the mounted optical disk 101 is a DVD + RW disk that is a recordable disk. Further, when both LV1 and LV2 are lower than the prescribed level, it is determined that the mounted optical disk 101 is a DVD-ROM disk that is a reproduction-only disk. Such a determination result is displayed on, for example, the display unit 107 under the control of the controller 105 and notified to the user.

Here, if the DVD-RW disk is mounted as the optical disk 101, since the push-pull signal S _PP is the level of frequency component of about 140kHz becomes large, the output signal SF1 and the band pass filter 122 of the band-pass filter 121 The output signal SF2 is obtained as shown in FIG. 4A (for example, SF1 is 180 mVp-p, and SF2 is 30 mVp-p). Therefore, in this case, since LV1> LV2 and LV1 is equal to or higher than a specified level (the specified level is a level corresponding to, for example, 100 mVp-p), it is determined that a DVD-RW disc is mounted. It will be.

Also, if the DVD + RW disk is mounted as the optical disk 101, the push-pull signal S _PP is because the level of the frequency component of about 810kHz becomes large, the output signal of the output signal SF1 and the band pass filter 122 of the band-pass filter 121 SF2 Is obtained as shown in FIG. 4B (for example, SF1 is 30 mVp-p, and SF2 is 200 mVp-p). Therefore, in this case, since LV2> LV1 and LV2 exceeds the specified level, it is determined that the DVD + RW disc is mounted.

Moreover, if the DVD-ROM disk is mounted as the optical disk 101, the push-pull signal S _PP has to become as about 140kHz and about both the level of the frequency component of 810kHz is small, the output signal SF1 and the band of the band-pass filter 121 The output signal SF2 of the pass filter 122 is obtained as shown in FIG. 4C. Therefore, in this case, since both LV1 and LV2 are smaller than the specified level, it is determined that the DVD-ROM disc is loaded.

As described above, in the present embodiment, in the wobble detecting section 118, by the band-pass filter 121, extracted from the push-pull signal S _PP, DVD-RW disc, the frequency components of the groove wobbles of DVD + RW disc, respectively Is done. Then, the detection levels LV1 and LV2 corresponding to the amplitude levels of the extracted frequency components are supplied from the wobble detection unit 118 to the controller 105. Then, the controller 105 determines the mounted optical disk 101 based on the detection levels LV1 and LV2.

  Therefore, in the present embodiment, determination as to whether or not the mounted optical disk 101 is a DVD-RW disk and determination as to whether or not the mounted optical disk 101 is a DVD + RW disk are performed in parallel. It can be determined in a short time with certainty whether the optical disc 101 is a recordable optical disc (DVD-RW disc, DVD + RW disc). As a result, for example, even when a copy-prohibited digital video signal is recorded on a recordable disc ignoring copy-prohibition, this can be immediately determined.

  In the present embodiment, when the mounted optical disc 101 is a recordable optical disc, the type can be known at the same time. This can reduce the possibility of trying to record on an optical disc that cannot be handled by mistake.

  In the above-described embodiment, the wobble detection unit 118 is configured as shown in FIG. 3, but may be configured as shown in FIG. In FIG. 5, parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Similar to the wobble detection unit 118 shown in FIG. 3, the wobble detection unit 118 includes a bandpass filter 121 having a center frequency f1 of 140 kHz and a bandpass filter 122 having a center frequency f2 of 810 kHz.

  The wobble detection unit 118 also includes a binarization circuit 131 that binarizes the output signal SF1 of the bandpass filter 121, a binarization circuit 131 that binarizes the output signal SF2 of the bandpass filter 131, and 2 A frequency signal FO1 is generated using the binarized signal from the binarization circuit 131 as a reference signal, and the binarized signal from the PLL circuit 133 that supplies the frequency signal FO1 to the controller 105 and the binarization circuit 132 is a reference signal. And a PLL circuit 134 that generates the frequency signal FO2 and supplies the frequency signal FO2 to the controller 105.

When performing the determination operation of the mounted optical disk 101, the wobble detecting section 118, the push-pull signal S _PP is processed, the frequency signal FO1, FO2 is generated, the frequency signal FO1, FO2 is supplied to the controller 105 The

That is, from the push-pull signal S _PP, the band-pass filter 121, the frequency component of about 140kHz is extracted. The output signal SF1 of the filter 121 is binarized by the binarization circuit 131, and the binarization signal from the binarization circuit 131 is supplied to the PLL circuit 133 as a reference signal. The frequency signal FO1 output from the PLL circuit 133 is supplied to the controller 105.

  In this case, when the level of the frequency component of about 140 kHz in the output signal SF1 of the band pass filter 121 is large, the binarized signal supplied to the PLL circuit 133 has a single frequency of about 140 kHz, and is used as the frequency signal FO1. A frequency signal of about 140 kHz is obtained. On the other hand, when the level of the frequency component of about 140 kHz in the output signal SF1 of the bandpass filter 121 is small, the binarized signal supplied to the PLL circuit 133 for the noise component has a single frequency of about 140 kHz. The frequency signal of about 140 kHz cannot be obtained as the frequency signal FO1.

Similarly, a frequency component of about 810 kHz is extracted from the push-pull signal _SPP by the band pass filter 122. The output signal SF1 of the filter 122 is binarized by the binarization circuit 132, and the binarization signal from the binarization circuit 132 is supplied to the PLL circuit 134 as a reference signal. The frequency signal FO2 output from the PLL circuit 134 is supplied to the controller 105.

  In this case, when the level of the frequency component of about 810 kHz in the output signal SF1 of the band pass filter 122 is large, the binarized signal supplied to the PLL circuit 134 has a single frequency of about 810 kHz, and the frequency signal FO2 A frequency signal of about 810 kHz is obtained. On the other hand, when the level of the frequency component of about 810 kHz in the output signal SF2 of the band pass filter 122 is small, the binarized signal supplied to the PLL circuit 134 due to the noise component has a single frequency of about 810 kHz. In other words, a frequency signal of about 810 kHz cannot be obtained as the frequency signal FO2.

  In the controller 105, the mounted optical disc 101 is determined as follows using the frequency signals FO1 and FO2. That is, when the frequency signal FO1 is a frequency signal of about 140 kHz, it is determined that the loaded optical disc 101 is a DVD-RW disc that is a recordable disc. When the frequency signal FO2 is a frequency signal of about 810 kHz, it is determined that the mounted optical disc 101 is a DVD + RW disc that is a recordable disc. Further, when the frequency signal FO1 is not a frequency signal of about 140 kHz and the frequency signal FO2 is not a frequency signal of about 810 kHz, it is determined that the mounted optical disk 101 is a DVD-ROM disk that is a reproduction-only disk. .

  The controller 105 determines the frequency of the frequency signals FO1 and FO2 by counting the period of the frequency signals FO1 and FO2 using, for example, a crystal precision clock. For example, when the period of the frequency signal FO2 is counted with a clock of 100 MHz, if the count is in the range of 118 to 129, the frequency of the frequency signal FO2 is 775.2 kHz to 847.5 kHz and within ± 5% of 810 kHz Therefore, the controller 105 determines that the frequency of the frequency signal FO2 is about 810 kHz. The width of ± 5% is considered in consideration of the difference in the measurement location, rotation speed, etc. of the optical disc 101. Although detailed numerical values are not shown, a width of ± 5% is similarly given when determining the frequency of the frequency signal FO1.

Here, if the DVD-RW disk is mounted as the optical disk 101, since the push-pull signal S _PP is the level of frequency component of about 140kHz becomes large, the output signal SF1 and the band pass filter 122 of the band-pass filter 121 The output signal SF2 is obtained as shown in FIG. 4A. Therefore, in this case, since the frequency signal FO1 is a frequency signal of about 140 kHz, it is determined that the DVD-RW disc is loaded.

Also, if the DVD + RW disk is mounted as the optical disk 101, the push-pull signal S _PP is because the level of the frequency component of about 810kHz becomes large, the output signal of the output signal SF1 and the band pass filter 122 of the band-pass filter 121 SF2 Is obtained as shown in FIG. 4B. Therefore, in this case, since the frequency signal FO2 is a frequency signal of about 810 kHz, it is determined that the DVD + RW disc is loaded.

Moreover, if the DVD-ROM disk is mounted as the optical disk 101, the push-pull signal S _PP is about 140kHz and about one, and therefore the level of the frequency component of 810kHz is small, the output signal SF1 and the band pass filter of the band-pass filter 121 The output signal SF2 122 is obtained as shown in FIG. 4C. Therefore, in this case, the frequency signal FO1 does not become a frequency signal of about 140 kHz, and the frequency signal FO2 does not become a frequency signal of about 810 kHz, and it is determined that the DVD-ROM disc is mounted. .

  In the above-described embodiment, two types of recordable optical discs (DVD-RW, DVD + RW) are determined in parallel. Similarly, a plurality of recordable optical discs are determined in parallel. Can be determined. In this case, however, the plurality of types of optical disks need to have different groove wobble frequencies.

  In the above-described embodiment, the present invention is applied to the DVD-type optical disk drive 100. However, the present invention is naturally applicable to a CD-type optical disk drive or the like.

DESCRIPTION OF SYMBOLS 100 ... Optical disk drive, 101 ... Optical disk, 103 ... Optical pick-up, 105 ... Controller, 106 ... Servo controller, 107 ... Display part, 109 ... RF amplifier part, 115. ..Read channel section, 116 ... demodulation / ECC section, 117 ... address processing section, 118 ... wobble detection section, 121,122 ... band pass filter, 123,124 ... level detection section , 125, 126 ... sample hold circuit, 127, 128 ... A / D converter, 131, 132 ... binarization circuit, 133, 134 ... PLL circuit

Claims (2)

Wobble signal reproducing means for reproducing a signal corresponding to the groove wobble from a predetermined position in the radial direction of the optical disk in a state where the mounted optical disk is rotated at a predetermined rotation speed;
A plurality of filter means for extracting a plurality of frequency components corresponding to the frequency of the groove wobble of a plurality of types of recordable optical discs from an output signal of the wobble signal reproducing means;
Detecting means for detecting the frequency level of the output signals of the plurality of filter means;
Disc discriminating means for discriminating the mounted optical disc using a detection signal of the detecting means,
The detection means detects the frequency level of the reference signal based on the output signals of a plurality of PLL circuit units to which the output signals of the plurality of filter means are respectively supplied as reference signals.
When the frequency level of the reference signal detected by the detecting means is a frequency in the first range, the disc discriminating unit discriminates that the loaded optical disc is the first optical disc,
When the frequency level of the reference signal detected by the detection means is a frequency in the second range, the disc discrimination means discriminates the loaded optical disc as a second optical disc,
When the frequency level of the reference signal detected by the detection means is neither the frequency in the first range nor the frequency in the second range, the disc discrimination means sets the loaded optical disc to the first level. An optical disk drive that discriminates that the optical disk is a third optical disk. A step of reproducing a signal corresponding to the groove wobble from a predetermined position in the radial direction of the optical disk in a state where the mounted optical disk is rotated at a predetermined rotation speed;
Extracting a plurality of frequency components corresponding to the frequency of the groove wobble of each of the recordable optical discs from the reproduced signal,
Detecting a frequency level output in the step of extracting the plurality of frequency components;
Using the detected frequency level to discriminate the mounted optical disc, and
When the detected frequency level is a frequency in the first range, it is determined that the mounted optical disc is the first optical disc,
When the detected frequency level is a frequency in the second range, it is determined that the mounted optical disk is a second optical disk,
An optical disc discrimination method, wherein when the detected frequency level is neither the frequency in the first range nor the frequency in the second range, the loaded optical disc is discriminated as a third optical disc.

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