JP3294899B2 - Optical disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an LD-ROM (Laser
An optical disk device represented by an optical disk player (LD player) for reproducing a read-only disk such as a Disk-Read Only Memory and recording and reproducing a recordable disk such as an LDR (Laser Disk Recordable).

[0002]

2. Description of the Related Art Hitherto, there has been no so-called compatible type optical information reproducing apparatus capable of detecting the type of a disk and reproducing both a recordable disk and a read-only disk.

[0003] In general, an optical disk which can be freely recorded and reproduced by a user is a dye-metal type which can be written once,
And a rewritable magneto-optical type and a phase change type. Until now, such optical discs have been
(Compact Disk Recordable) only, but it is thought that a recordable / reproducible optical disc such as a high density recording / reproducing disc having different LDR (Laser Disk Recordsable) and recording / reproducing wavelength may appear in the near future. Also, OMD
D (Optical Memory Disk Drive), VDR (Video Di
There is also an optical disk such as a sk recorder that can record and reproduce data. In these cases, the optical disk is stored in a case in advance, and a hole for detecting the type of the disk is provided outside the case.

[0004]

However, in the case of a disk having no disk case, the conventional optical information reproducing apparatus cannot detect the type of the disk.
The user had to input the disc type in advance.

An object of the present invention is to provide an optical information reproducing apparatus capable of automatically detecting the type of a disc.

[0006]

According to the present invention, there is provided an optical disk apparatus capable of recording or reproducing information on or from an optical disk mounted thereon, comprising: a first light beam for recording or reproducing information on or from the optical disk; An optical pickup that irradiates the optical disc with a tilt sensor that irradiates the optical disc with a second light beam having a wavelength larger than the first light beam for detecting an inclination of the optical disc; A reflectance detector for detecting a reflectance of the optical disk with respect to a first light beam and the second light beam emitted by the tilt sensor; and an output indicating respective reflectances detected by the reflectance detector. Determine whether the optical disk is a read-only optical disk, a dye-based optical disk, or a phase-change optical disk based on a signal. That and a disk judging means.

[0007]

According to the configuration of the present invention, the optical disk is driven based on the output signal indicating the reflectance of the optical disk with respect to the first light beam irradiated by the optical pickup and the second light beam irradiated by the tilt sensor. It is determined whether the optical disk is a read-only optical disk, a dye-based optical disk, or a phase-change optical disk.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In the drawings, the same components are denoted by the same reference numerals.

FIG. 1 is a diagram showing a first embodiment of a disc reflectance detecting apparatus and a disc type judging circuit in an optical information reproducing apparatus according to the present invention. Here, light of three wavelengths is used as an example, and the reflectance of the disk with respect to the light of these three wavelengths is measured to determine the type of the disk. Two of the three wavelengths correspond to the DC output 1 of the optical pickup 3 for recording and reproducing optical information.
5 (780 nm) and the DC output 13 (950 nm) of one or both of the light receiving elements of the tilt sensor 2 for detecting the tilt of the disk. As a wavelength other than these two wavelengths (780 nm and 950 nm), 66
A 0 nm LED was used. Other types of wavelengths can be used depending on the type of disk.

In FIG. 1, one output signal of the tilt sensor 2 is amplified via an operational amplifier 7 and supplied to an output terminal 12 for detecting the inclination of the disk. The other output of the tilt sensor 2 is amplified via the operational amplifier 8 and supplied to the arithmetic circuit 17 as a DC output signal for detecting the type of the disk. Further, one output signal (each servo output signal and RF output signal) from the optical pickup 3 is amplified via the operational amplifier 9 and output from the output terminal 14.
The other output signal (the DC output signal for detecting the type of disk) is amplified by the operational amplifier 10 and supplied to the arithmetic circuit 17. Further, light from an LED (Light Emitting Diode) reflected by the disk 1 is transmitted to a PD (Passive Device).
Is supplied from the sensor 6 via the operational amplifier 11 to the arithmetic circuit 17 as a DC output signal for disc type detection.
As shown in FIG. 2, it is also possible to make the LED and the PD have an angle so that the reflected light on the disk surface is diffused and the reflected light from the disk can be efficiently incident on the PD. Each DC output signal proportional to the reflectance of light on the disk recording medium for each of the three wavelengths is input to the arithmetic circuit 17. The arithmetic circuit 17 calculates the reflectances of the three wavelengths of light on the recording medium from the DC output signals to, and output signals indicating these reflectances are supplied to the disk type detection circuit 18 to determine the type of each disk. Can be determined. The DC amplifier gain of each DC output can also be adjusted so that the reflectance can be directly compared.

FIG. 3 shows a circuit configuration of the arithmetic circuit 17 shown in FIG. Each DC output signal, and
Supplied to the inverting input terminal of the differential amplifier (21-26),
The reflectance of light of each wavelength is classified into three levels. Here, as an example, it was classified into three levels,
The number of classifications can be changed according to the type of disc to be handled.
Further, to the non-inverting input terminal of the comparator (21, 23, 25), is supplied with voltages V ₁ which defines the threshold to the non-inverting input terminal of the comparator (22, 24, 26), the threshold value the voltage V ₂ is supplied to define the. Each differential amplifier (21 and 22, 23 and 24, 25 and 26)
Are output from the disc reflectance determination circuits 27 and 2 respectively.
8 and 29, and each reflectance determination circuit (27, 28,
The output of 29) is supplied to the disc type detection circuit 18.

Next, the operation of the arithmetic circuit 17 will be described. For simplicity, only the processing operation of the DC output signal will be described, and the description of the DC output and the DC output will be omitted. Here, the voltage V ₁ is the threshold value when the light reflectance to the disk is 50%, and the voltage V 1
₂ is a threshold value when the light reflectance to the disk is 30%, and it is assumed that the magnitude of the DC output increases as the light reflectance increases. The signal magnitudes in the respective reflectance ranges are shown below. I) When the DC output signal is a detection signal indicating a reflectance of 0 to 30% [magnitude of the detection signal] <[voltage V ₂ ] <[voltage V ₁ ], and the outputs of the differential amplifiers 21 and 22 are Both + V
(High level), and these signal levels are supplied to the reflectance determination circuit 27. II) When the DC output signal is a detection signal indicating a reflectance of 30 to 50%: [voltage V ₂ ] <[magnitude of the detection signal] <[voltage V ₁ ], and the output of the differential amplifier 21 is + V ( high level),
The output of the differential amplifier 22 becomes -V (low level), and these signal levels are supplied to the reflectance determination circuit 27. III) When the DC output signal is a detection signal indicating a reflectance of 0 to 30%: [voltage V ₂ ] <[voltage V ₁ ] <[magnitude of detection signal], and the outputs of the differential amplifiers 21 and 22 are Together -V
(Low level), and these signal levels are supplied to the reflectance determination circuit 27. FIG.
According to the conversion table shown in FIG.
The three types of signals, Y and Z, are supplied to a disk type detection circuit 18. (Here, the division of the reflectance can be changed according to the situation.) The operations of the reflectance determination circuits 28 and 29 are the same as the operations of the reflectance detection circuit 27.

FIGS. 5 to 10 show the spectral reflectances of the six types of disks. FIG. 5 is a diagram showing the spectral reflectance with respect to the wavelength of an aluminum disk (read-only disk). As shown in FIG. 5, the DC output (output of the tilt sensor: wavelength 950)
nm), DC output (pickup output: wavelength 780)
nm) and DC output (LED output: wavelength 660n)
The spectral reflectances for m) are each in the range of 50-100%. Therefore, in the case of an aluminum disk, the reflectance determination circuits 27, 28 and 29 output signals Z and Z, respectively.
And Z are supplied to a disc type detection circuit 18.

FIG. 6 is a diagram showing the spectral reflectance with respect to the wavelength of a dye disk (write once). According to FIG.
C output (output of tilt sensor: wavelength 950 nm), D
The spectral reflectances for the C output (the output of the pickup: wavelength of 780 nm) and the DC output (the output of the LED: wavelength of 660 nm) are in the range of 50 to 100%, respectively.
-50%, and 0-30%. Therefore, in the case of a dye disk (write once), the signals Z, Y and X are supplied from the reflectance determination circuits 27, 28 and 29 to the disk type detection circuit 18, respectively.

FIG. 7 is a diagram showing the spectral reflectance with respect to the wavelength of the unrecorded phase change disk A. 7, the DC output (output of the tilt sensor: wavelength 950 nm), DC output (output of the pickup: wavelength 780 nm), and DC
The spectral reflectance with respect to the output (LED output: wavelength 660 nm) is in the range of 0 to 30%, 30 to 50%, and 50 to 100%, respectively. Therefore, in the case of the unrecorded phase change disk A, the reflectance determination circuits 27 and 28
And 29, the signals X, Y and Z are supplied to the disc type detecting circuit 18, respectively.

FIG. 8 is a diagram showing the spectral reflectance with respect to the wavelength of the phase-change disk A after recording. 8, the DC output (output of tilt sensor: wavelength 950 nm), DC output (output of pickup: wavelength 780 nm), and DC output
The spectral reflectance with respect to the output (LED output: wavelength 660 nm) is in the range of 0 to 30%, 0 to 30%, and 30 to 50%, respectively. Therefore, in the case of the phase-change disk A after recording, the signals X, X and Y are supplied from the reflectance determination circuits 27, 28 and 29 to the disk type detection circuit 18, respectively.

FIG. 9 is a diagram showing the spectral reflectance with respect to the wavelength of the unrecorded phase change disk B. As shown in FIG. 9, the DC output (tilt sensor output: wavelength 950 nm), DC output (pickup output: wavelength 780 nm), and DC
The spectral reflectance with respect to the output (LED output: wavelength 660 nm) is in the range of 0 to 30%, 30 to 50%, and 30 to 50%, respectively. Therefore, in the case of the unrecorded phase change disk B, the signals X, Y and Y are supplied from the reflectance determination circuits 27, 28 and 29 to the disk type detection circuit 18, respectively.

FIG. 10 is a diagram showing the spectral reflectance with respect to the wavelength of the phase-change disk B after recording. According to FIG.
Output (tilt sensor output: wavelength 950 nm), DC
The spectral reflectances for output (pickup output: wavelength 780 nm) and DC output (LED output: wavelength 660 nm) are in the range of 30 to 50% and 0 to 30, respectively.
% And 30-50%. Therefore, in the case of the phase-change disk B after recording, the reflectance determination circuits 27 and 2
8 and 29, the signals Y, X and Y are supplied to the disc type detection circuit 18, respectively.

FIG. 11 summarizes the results of FIGS.
Shown in The disc type detection circuit 18 is, for example, as shown in FIG.
According to the disk classification conversion table shown in FIG.
7, the disc type is determined based on whether the output signal of the reflectance detection circuits 27, 28, and 29 is X, Y, or Z, and a signal indicating the disc type is transmitted to each servo system (focus servo). , Tracking servo).

As in the above embodiment, the type of the disc can be determined by using a two-color LED without using the outputs of the recording / reproducing pickup and the tilt sensor. In FIG.
FIG. 2 shows a plan view of a reflectance measuring apparatus when two sets of two-color LED and PD are used. In FIG. 12, two-color LEDs 30 and 3
1 emits light of different wavelengths from each other,
Is received by the light receiving element 32 and the two-color LE
The light from D31 is received by the light receiving element 33.
By using the reflectance measuring device having such a configuration, it is possible to measure the reflectance of light on a disk recording medium with respect to four wavelengths.

Further, in the above-described modified example, light of four wavelengths is generated by using two-color LEDs of different wavelengths, but light of different wavelengths can be generated by using a multicolor LED. FIG. 13 shows a configuration of a multicolor LED that generates light of three different wavelengths. In FIG. 13, LEDs of different wavelengths have a common cathode, and light of different wavelengths is generated by passing a current through each anode. Here, for example, three LEDs of different wavelengths are used, but L or more of four or more different wavelengths are used.
ED can also be used. Therefore, one multicolor L
Using the ED and one light receiving element, it is possible to measure the reflectance of light on a disk recording medium at several wavelengths.

Further, by dividing the light receiving element into multiple parts and attaching a band-pass filter for each wavelength to each of the divided parts,
It is also possible to completely separate the DC output level of light of each wavelength. FIG. 14 shows four divided light receiving elements each having a bandpass filter having a different wavelength. The light receiving element shown in FIG. 14 has four bandpass filters A, B, C, and D having different wavelengths, and a signal indicating the intensity of light transmitted through each of the filters is transmitted through an operational amplifier.
C output terminal.

In still another modification, the reflectance of a disk recording medium for each wavelength is measured by time division. FIG.
FIG. 5 shows an example. FIG. 15 shows the case where the reflectance of light from three LEDs is measured by one light receiving element. Here, the reflectance of light from each LED is measured every 100 msec. Specifically, the light receiving element has a length of 0 to 100 ms.
At ec, only the reflected light of LED1 is received, and a DC output indicating the reflectance is output. During 100 to 200 msec, only the reflected light of LED2 is received, and a DC output indicating the reflectance is output. In 300 msec, L
It receives only the reflected light of ED3 and outputs a DC output indicating its reflectance.

[0024]

An optical disk device according to the present invention is an optical disk device capable of recording or reproducing information on or from an optical disk mounted thereon, wherein a first light beam for recording or reproducing information on or from the optical disk is applied to the optical disk. An optical pickup for irradiating, a tilt sensor for irradiating the optical disk with a second light beam having a wavelength larger than the first light beam for detecting a tilt of the optical disk, and a first light for irradiating the optical pickup A reflectance detector for detecting a reflectance of the optical disk with respect to the beam and the second light beam emitted by the tilt sensor; and an output signal indicating the respective reflectance detected by the reflectance detector. The optical disk is a read-only optical disk,
A disk determining unit for determining whether the optical disk is a dye-based optical disk or a phase-change optical disk. This allows
The optical disk device can determine whether the mounted optical disk is a read-only optical disk, a dye-based optical disk, or a phase-change optical disk, using only the optical pickup and the tilt sensor. Further, when the type of the disc is determined in this way, optimization of each servo (focus servo, tracking servo) gain, and in the case of a recordable optical disc, determination of the optimum recording power and the optimum recording duty can be performed. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a disk reflectance detection apparatus and a disk type determination circuit in an optical disk apparatus according to the present invention.

FIG. 2 is a diagram showing a reflectance measuring device using an LED.

FIG. 3 is a circuit diagram showing a configuration of an arithmetic circuit 17.

FIG. 4 is a diagram illustrating a conversion table of an output signal with respect to an input signal of the reflectance detection circuit.

FIG. 5 is a diagram showing the spectral reflectance of an aluminum disk (read-only disk).

FIG. 6 is a diagram showing the spectral reflectance with respect to the wavelength of a dye disk (write once).

FIG. 7 is a diagram showing a spectral reflectance with respect to a wavelength of an unrecorded phase change disk A.

FIG. 8 is a diagram showing a spectral reflectance with respect to a wavelength of a phase-change disk A after recording.

FIG. 9 is a diagram showing a spectral reflectance with respect to a wavelength of an unrecorded phase change disk C.

FIG. 10 is a diagram showing a spectral reflectance with respect to a wavelength of a phase-change disk C after recording.

FIG. 11 is a diagram showing a disc classification conversion table of a disc type detection circuit.

FIG. 12 is a plan view of a reflectance measuring device when a two-color LED is used.

FIG. 13 shows a multicolor LE for generating light of three different wavelengths.
FIG. 3 is a diagram showing a configuration of D.

FIG. 14 is a diagram illustrating four-divided light receiving elements each having a band-pass filter having a different wavelength.

FIG. 15 is an explanatory diagram of a method of measuring a disk recording medium reflectance for each wavelength by time division.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk 2 ... Tilt sensor 3 ... Optical pickup 4 ... LED 5 ... PD 6 ... Reflectance measuring device 7, 8, 9, 10, 11 ... Op amp 12 ... Tilt sensor output 13 ... DC output 14 ... Each servo RF output 15 ... DC output 16 ... DC output 17 ... Operation circuit 18 ... Disc type detection circuit 19 ... Each servo system

Claims (3)

(57) [Claims] An optical disk device capable of recording or reproducing information on or from an optical disk mounted thereon, a first optical disk for recording or reproducing information on or from the optical disk.
Optical pickup for irradiating the optical disk with a light beam
And the first optical beam for detecting the tilt of the optical disk.
The second optical beam having a wavelength larger than the
A first light beam irradiated by the optical pickup;
With respect to the second light beam emitted by the tilt sensor
A reflectance detector means for detecting a reflectance of the optical disk, indicating the reflectance of each of said reflectance detector means detects
The optical disc is read-only optical disc based on the output signal.
Disk, dye-based optical disk or phase change optical disk
Optical disc apparatus characterized by and a disk judging means for judging whether. 2. The first light beam having a wavelength smaller than that of the first light beam.
A light emitting element for irradiating the optical disk with the light beam of No. 3
In addition, the reflectivity detecting means is capable of detecting the front of the third light beam.
2. The optical disk device according to claim 1 , wherein the reflectance of the optical disk is detected . 3. The apparatus according to claim 2, wherein the disc determination unit is configured to detect the reflectance.
The first light beam and the second light beam detected by the
The optical disk with respect to the beam and the third light beam.
Based on the output signal indicating the reflectivity, the optical disc is replayed.
Raw optical disk, dye-based optical disk, unrecorded phase change type
The optical disk device according to claim 2, wherein the optical disk device determines whether the optical disk is an optical disk or a phase-change optical disk after recording .