Claims
- 1. An optical disc device comprising:a laser light source for radiating a laser light beam illuminated via an objective lens on a signal surface of an optical disc; return light detection means for detecting the reflected light radiated from the laser light source and reflected from the signal surface of said optical disc; disc discriminating means for discriminating the type of said optical disc based on a number of reflectivity peaks detected by said return light detection means in a sole focussing search operation for focussing said objective lens onto said signal surface, said number of reflectivity peaks corresponding to a same number of signal surfaces that said disc comprises; means for detecting tracking error signals of plural different types of different detection systems based on the detection output of said return light detection means; tracking means for displacing the objective lens along the radius of said optical disc responsive to said tracking error signals for tracking-controlling a laser spot of the laser light focussed on the signal surface of the optical disc; and controlling means for controlling operation of said optical disc device based on a discriminating output by said disc discriminating means.
- 2. The optical disc device of claim 1, wherein a first disc type is discriminated when only reflectivity peaks corresponding to two signal surfaces are detected in said sole focussing search operation.
- 3. The optical disc device of claim 2, wherein a second disc type is discriminated when only one reflectivity peak corresponding to a single signal surface of said disc is detected during said sole focussing search operation.
- 4. The optical disc device of claim 1, wherein a first disc type is discriminated when only one reflectivity peak corresponding to a single signal surface of said disc is detected during said sole focussing search operation.
- 5. A method of discriminating a loaded one of plural types of optical discs for data recording/reproduction using an optical disc device which includes a laser light source, a light detector, a processor, electrical discriminating circuitry, tracking servo and tracking error circuitry, comprising the steps of:radiating a laser light beam illuminated via an objective lens on a signal surface of an optical disc; detecting the radiated light reflected from a signal surface of said loaded optical disc; moving said objective lens in a sole focussing search operation for focussing said objective lens onto said signal surface such that a focal plane of said lens moves through all signal surfaces of said loaded optical disc; discriminating which of the plural types of said optical discs is the loaded one based on a number of reflectivity peaks detected in said sole focussing search operation, said number of reflectivity peaks corresponding to a same number of signal surfaces that said loaded disc comprises; controlling operation of said optical disc device based on discriminating output.
- 6. The method of claim 5, wherein a first disc type is discriminated in said discriminating step when two refelectively peaks corresponding to two signal surfaces are detected in said sole focussing search operation.
- 7. The method of claim 6, wherein a second disc type is discriminated in said discriminating step when only one reflectivity peak corresponding to a single surface of said disc is detected during said sole focussing search operation.
- 8. The method of claim 5, wherein a first disc type is said discriminated in said discriminating step when only one reflectively peak corresponding to a single surface of said disc is detected during said sole focussing search operation.
- 9. An optical disc device comprising:a laser light source for radiating a laser light beam illuminated via an objective lens on a signal surface of an optical disc; a detector for detecting the reflected light radiated from the laser light source and reflected from the signal surface of said optical disc; a discriminator circuit for discriminating the type of said optical disc based on a number of reflectivity peaks detected by said detector in a sole focussing search operation for focussing said objective lens onto said signal surface, said number of reflectivity peaks corresponding to a same number of signal surfaces that said disc comprises; a tracking circuit for detecting tracking error signals of plural different types of different detection systems based on the detection output of said detector; a tracking servo for displacing the objective lens along the radius of said optical disc responsive to said tracking error signals for tracking-controlling a laser spot of the laser light focussed on the signal surface of the optical disc; and a controller for controlling operation of said optical disc device based on a discriminating output by said discriminator circuit.
- 10. The optical disc device of claim 9, wherein a first disc type is discriminated when two reflectivity peaks corresponding to two signal surfaces are detected in said sole focussing search operation.
- 11. The optical disc device of claim 10, wherein a second disc type is discriminated when only one reflectively peak corresponding to a single signal surface of said disc is detected during said sole focussing search operation.
- 12. The optical disc device of claim 9, wherein a first disc type is discriminated when only one reflectively peak corresponding to single surface of said disc is detected during said sole focussing search operation.
- 13. An optical disc device comprising:a laser light source for radiating a laser light beam illuminated via an objective lens on a signal surface of an optical disc; return light detection means for detecting the reflected light radiated from the laser light source and reflected from the signal surface of said optical disc; disc discriminating means for discriminating the type of said optical disc based on a number of reflectivity peaks detected by said return light detection means in a sole focussing search operation, said number of reflectivity peaks corresponding to a same number of signal surfaces that said disc comprises; means for detecting tracking error signals of plural different types of different detection systems based on the detection output of said return light detection means; tracking means for displacing the objective lens along the radius of said optical disc responsive to said tracking error signals for tracking-controlling a laser spot of the laser light focussed on the signal surface of the optical disc; and controlling means for controlling operation of said optical disc device based on a discriminating output by said disc discriminating means, wherein a first disc type is discriminated when two reflectivity peaks corresponding to two signal surfaces are detected in said sole focussing search operation.
- 14. The optical disc device of claim 13, wherein a second disc type is discriminated when only one reflectivity peak corresponding to a single signal surface of said disc is detected during said sole focussing search operation.
- 15. The optical disc device of claim 13, wherein a first disc type is discriminated when only one reflectivity peak corresponding to a single signal surface of said disc is detected during said sole focussing search operation.
- 16. A method of discriminating a loaded one of plural types of optical discs for data recording/reproduction using an optical disc device which includes a laser light source, a light detector, a processor, electrical discriminating circuitry, tracking servo and tracking error circuitry, comprising the steps of:radiating a laser light bean illuminated via an objective lens on a signal surface of an optical disc; detecting the radiated light reflected from a signal surface of said loaded optical disc; moving said objective lens in a sole focussing search operation such that a focal plane of said lens moves through all signal surfaces of said loaded optical disc; discriminating which of the plural types of said optical discs is the loaded one based on a number of reflectivity peaks detected in said sole focussing search operation, said number of reflectivity peaks corresponding to a same number of signal surfaces that said loaded disc comprises; controlling operation of said optical disc device based on discriminating output, wherein a first disc type is discriminated in said discriminating step when two reflectivity peaks corresponding to two signal surfaces are detected in said sole focussing search operation.
- 17. The method of claim 16, wherein a second disc type is discriminated in said discriminating step when only one reflectivity peak corresponding to a single signal surface of said disc is detected during said sole focussing search operation.
- 18. The method of claim 16, wherein a first disc type is discriminated in said discriminating step when only one reflectivity peak corresponding to a single signal surface of said disc is detected during said sole focussing search operation.
- 19. An optical disc device comprising:a laser light source for radiating a laser light beam illuminated via an objective lens on a signal surface of an optical disc; a detector for detecting the reflected light radiated from the laser light source and reflected from the signal surface of said optical disc; a discriminator circuit for discriminating the type of said optical disc based on a number of reflectivity peaks detected by said detector in a sole focussing search operation, said number of reflectivity peaks corresponding to a same number of signal surfaces that said disc comprises; a tracking circuit for detecting tracking error signals of plural different types of different detection systems based on the detection output of said detector; a tracking servo for displacing the objective lens along the radius of said optical disc responsive to said tracking error signals for tracking-controlling a laser spot of the laser light focussed on the signal surface of the optical disc; and a controller for controlling operation of said optical disc device based on a discriminating output by said discriminator circuit, wherein a first disc type is discriminated when two reflectivity peaks corresponding to two signal surfaces are detected in said sole focussing search operation.
- 20. The optical disc device of claim 19, wherein a second disc type is discriminated when only one reflectivity peak corresponding to a single signal surface of said disc is detected during said sole focussing search operation.
- 21. The optical disc device of claim 19, wherein a first disc type is discriminated when only one reflectivity peak corresponding to a single signal surface of said disc is detected during said sole focussing search operation.
Priority Claims (1)
Number |
Date |
Country |
Kind |
P09-014777 |
Jan 1997 |
JP |
|
Parent Case Info
This is a divisional of application Ser. No. 09/003,933, filed Jan. 7, 1998, now U.S. Pat. No. 6,147,941.
US Referenced Citations (4)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0745982 A2 |
Dec 1996 |
EP |
0766234 A1 |
Apr 1997 |
EP |
2304226 A |
Mar 1997 |
GB |
Non-Patent Literature Citations (1)
Entry |
Patent Abstracts of Japan, JP 8-83465, published Mar. 26, 1996, Sony Corporation. |