OPTICAL DISC APPARATUS AND OPTICAL DISC DISCRIMINATING METHOD

Abstract

An optical disc apparatus includes an optical pickup which irradiates a first laser beam for reproducing a first DVD medium, or a second laser beam for reproducing a second DVD medium onto a installed optical disc, and receives the reflected light from the installed optical disc, a controller determines that the installed optical disc is the second DVD medium when a value by normalizing the amplitude of a RF signal generated from the reflected light with a coefficient is larger than first threshold value and smaller than a second threshold value, and the controller determines that the installed optical disc is the first DVD medium when the value is not larger than first threshold value and smaller than a second threshold value.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a block diagram showing a general configuration of an optical disc apparatus according to an embodiment of the present invention;

FIG. 2 is a flowchart to help explain the process of discriminating optical discs according to the embodiment;

FIG. 3 shows a SBAD signal and a focus error signal which are obtained when the optical disc is a CD;

FIG. 4 shows a SBAD signal and a focus error signal which are obtained when the optical disc is a DVD/HD DVD;

FIG. 5 shows an amplitude of A_n in the case of a read-only DVD-ROM or a recorded recording DVD medium;

FIG. 6 shows amplitude A_n in the case of a HD DVD; and

FIG. 7 shows amplitude A_n in the case of a unrecorded recording DVD medium.

Claims

1. An optical disc apparatus capable of installing a optical disc selected from a plurality of types of optical discs including a first Digital Versatile Disc (DVD) medium including a first track width, and a second Digital Versatile Disc (DVD) medium including a second track width is shorter than the first track width is installed, the optical disc apparatus comprising: a motor which rotates the installed optical disc;an optical pickup which irradiates a first laser beam for reproducing the first DVD medium, or a second laser beam for reproducing the second DVD medium onto the installed optical disc through an objective lens, and receives the reflected light from the installed optical disc;a moving mechanism which moves the optical pickup across the radius of the optical disc;a signal generating section which generates a focus error signal, a tracking error signal, and RF signal using the reflected light, and outputs the generated signals;a driving section which drives the optical pickup according to the focus error signal and the tracking error signal for performing to a focus control and a track positioning control; anda controller which controls the motor, the signal generating section, and the driving section,the controller controls the moving mechanism and moves the optical pickup at a position opposite to a predetermined area of the installed optical disc,the controller controls the optical pickup for irradiating the first laser beam onto the rotating installed optical disc,the controller controls the driving section and detects a amplitude of the RF signal when the first laser beam is focused on the predetermined area,the controller determines that the installed optical disc is the second DVD medium when a value by normalizing the amplitude of the RF signal with a coefficient is larger than first threshold value and smaller than a second threshold value, andthe controller determines that the installed optical disc is the first DVD medium when the value is not larger than first threshold value and smaller than a second threshold value.

2. The optical disc apparatus according to claim 1, wherein the controller controls the driving section for carrying out a focus search in state that the first laser beam is irradiated onto the predetermined area, and measures a distance from a surface of the installed optical disc to a recording layer of the installed optical disc and a reflectivity of the installed optical disc, and the coefficient is the reflectivity.

3. The optical disc apparatus according to claim 2, wherein the controller determines the installed optical disc as another optical disc when the measured distance is predetermined distance.

4. The optical disc apparatus according to claim 2, wherein the reflectivity is the amplitude of the focus error signal or a amplitude of an SBAD signal.

5. The optical disc apparatus according to claim 1, wherein the first DVD medium is a DVD-ROM or recording DVD medium, and the second DVD medium is a High-Definition Digital Versatile Disc (HD DVD).

6. An optical disc apparatus capable of installing a optical disc selected from a plurality of types of optical discs including compact disc, a first Digital Versatile Disc (DVD) medium including a first track width, and a second Digital Versatile Disc (DVD) medium including a second track width is shorter than the first track width is installed, the optical disc apparatus comprising: a motor which rotates the installed optical discan optical pickup which irradiates a CD laser beam for reproducing the compact disc, a first laser beam for reproducing the first DVD medium, or a second laser beam for reproducing the second DVD medium onto the installed optical disc through an objective lens, and receives the reflected light from the installed optical disc;a moving mechanism which moves the optical pickup across the radius of the optical disc;a signal generating section which generates a focus error signal, a tracking error signal, and RF signal using the reflected light, and outputs the generated signals;a driving section which drives the optical pickup according to the focus error signal and the tracking error signal for performing to a focus control and a track positioning control; anda controller which controls the motor, the signal generating section, and the driving section,the controller controls the moving mechanism and moves the optical pickup at a position opposite to a predetermined area of the installed optical disc,the controller controls the optical pickup for irradiating the first laser beam onto the rotating installed optical disc,the controller carries out a focus search by controlling the driving section and driving the optical pickup, and measures a distance from a surface of the installed optical disc to a recording layer of the installed optical disc and a reflectivity of the installed optical disc,the controller determines that the installed optical disc is the compact disc when the measured distance is a predetermined distance,the controller controls the driving section and measures a amplitude of the RF signal in state that the first laser beam is focused on the predetermined area when the measured distance is not the predetermined distance,the controller determines that the installed optical disc as the second DVD medium when a value by normalizing the amplitude of the RF signal with a coefficient is larger than first threshold value and smaller than a second threshold value, andthe controller determines that the installed optical disc is the first DVD medium when the value is not larger than first threshold value and smaller than a second threshold value.

7. The optical disc apparatus according to claim 6, wherein the reflectivity is the amplitude of the focus error signal or a amplitude of an SBAD signal.

8. An optical disc discriminating method which discriminates a kind of an optical disc installed an optical disc apparatus capable of installing a optical disc selected from a plurality of types of optical discs including a first Digital Versatile Disc (DVD) medium including a first track width, and a second Digital Versatile Disc (DVD) medium including a second track width is shorter than the first track width is installed, the optical disc discriminating method comprising: moving a optical pickup at a position opposite to a predetermined area of the installed optical disc;irradiating a first laser beam for reproducing the first DVD medium onto the installed optical disc from the optical pickup;controlling the optical pickup according to a focus error signal and tracking error signal which are generated from a reflected light and measuring a amplitude of a RF signal generated from the reflected light in state that the first laser beam is focused on the predetermined area;determining the installed optical disc as the second DVD medium when a value by normalizing the amplitude of the RF signal with a coefficient is larger than first threshold value and smaller than a second threshold value; anddetermining the installed optical disc as the first DVD medium when the value is not larger than first threshold value and smaller than a second threshold value.

9. The optical disc discriminating method according to claim 8, further comprising: measuring a distance from a surface of the installed optical disc to a recording area of the installed optical disc and a reflectivity of the installed optical disc by carrying out a focus search; and wherein the coefficient is the reflectivity.

10. The optical disc discriminating method according to claim 8, further comprising: determining the installed optical disc as another optical disc when the measured distance is predetermined distance.

11. The optical disc discriminating method according to claim 9, wherein the reflectivity is the amplitude of the focus error signal or a amplitude of an SBAD signal.

12. The optical disc discriminating method according to claim 8, wherein the first DVD medium is a DVD-ROM or recording DVD medium, and the second DVD medium is a High-Definition Digital Versatile Disc (HD DVD).

13. An optical disc discriminating method which discriminates a kind of an optical disc installed an optical disc apparatus capable of installing a optical disc selected from a plurality of types of optical discs including a compact disc, a first DVD medium including a first track width, and a second DVD medium including a second track width is shorter than the first track width is installed, the optical disc discriminating method comprising: moving a optical pickup at a position opposite to a predetermined area of the installed optical disc;irradiating a first laser beam for reproducing the first DVD medium onto the installed optical disc from the optical pickup,controlling and driving the optical pickup according to a focus error signal and tracking error signal which are generated from a reflected light, and measuring a distance from a surface of the installed optical disc to a recording area of the installed optical disc and reflectivity of the installed optical disc by carrying out a focus search in state that the first laser beam is irradiated onto the predetermined area;determining the installed optical disc as the compact disc when the measured distance is predetermined distance;controlling and driving the optical pickup using the focus error signal and measuring a amplitude of a RF signal generated from the reflected light in state that the first laser beam is focused on the predetermined area, when the measured distance is not predetermined distance;determining the installed optical disc as the second DVD medium when a value by normalizing the amplitude of the RF signal with a coefficient is larger than first threshold value and smaller than a second threshold value; anddetermining the installed optical disc as the first DVD medium when the value is not larger than first threshold value and smaller than a second threshold value.

14. The optical disc discriminating method according to claim 13, wherein the reflectivity is the amplitude of the focus error signal or a amplitude of an SBAD signal.