Optical disk apparatus, control method, control program and information storage medium

1. An optical disc apparatus capable of reading out information stored in an optical disc medium of a first type and another optical disc medium of a second type, said optical disc apparatus comprising:

an optical pickup radiating

light having a first wavelength provided for said optical disc medium of said first type and

light having a second wavelength which is smaller than said first wavelength and provided for said optical disc medium of said second type;

a signal outputting section outputting an output signal according to reflected light obtained as a result of reflection on said optical disc medium of light radiated by said optical pickup; and

a type determination section requesting said optical pickup to radiate light having said first wavelength to an object optical disc medium serving as an object of type determination to acquire an output signal output by said signal outputting section and determining the type of said object optical disc medium based on the number of detected peaks appearing in said acquired output signal output by said signal outputting section while moving said optical pickup in a direction to said object optical disc medium;

wherein while moving said optical pickup in a direction approaching said object optical disc medium, said type determination section requests said optical pickup to radiate light having said first wavelength to said object optical disc medium to acquire an output signal output by said signal outputting section and determines the type of optical disc medium based on comparing a peak initially appearing in said acquired output signal to a first predetermined threshold value and a second predetermined threshold value, the second predetermined threshold value being substantially greater than the first predetermined threshold value.

2. The optical disc apparatus according to claim 1 wherein, while moving said optical pickup in a direction approaching said object optical disc medium, said type determination section requests said optical pickup to radiate light having said first wavelength to said object optical disc medium to acquire an output signal output by said signal outputting section and determines that said object optical disc medium is an optical disc medium of said second type if a peak initially appearing in said acquired output signal is equal to or greater than a predetermined threshold value.

3. The optical disc apparatus according to claim 1 wherein,

while moving said optical pickup in a direction to said object optical disc medium, said type determination section requests said optical pickup to radiate light having said second wavelength to said object optical disc medium to acquire an output signal output by said signal outputting section; and

if two reflected signals, which include

a reflected signal reflected by a medium surface of said object optical disc medium and

a reflected signal reflected by a signal surface of said object optical disc medium,

can be detected from said acquired output signal, said type determination section determines the type of said object optical disc medium on the basis of said two reflected signals, or

if said two reflected signals cannot be detected from said acquired output signal, said type determination section determines the type of said object optical disc medium on the basis of the number of peaks appearing on an output signal acquired by said type determination section by radiating light having said first wavelength.

4. The optical disc apparatus according to claim 1 , wherein determining the type of said object optical disc medium based on the number of detected peaks includes determining the type of said object optical disc medium based on whether two peaks are detected or only one peak is detected.

5. The optical disc apparatus according to claim 4 , wherein determining the type of said object optical disc medium based on the number of detected peaks includes determining that the type of said object optical disc medium is the first type, based on the detection of two peaks.

6. The optical disc apparatus according to claim 4 , wherein determining the type of said object optical disc medium based on the number of detected peaks includes determining that the type of said object optical disc medium is the second type, based on the detection of only one peak.

7. The optical disc apparatus according to claim 1 , wherein determining the type of optical disc medium based on comparing a peak initially appearing in said acquired output signal to a first predetermined threshold value and a second predetermined threshold value includes determining that the initially appearing peak is equal to or greater than the first predetermined threshold value and less than the second predetermined threshold value.

8. The optical disc apparatus according to claim 1 , wherein determining the type of optical disc medium based on comparing a peak initially appearing in said acquired output signal to a first predetermined threshold value and a second predetermined threshold value includes determining that the initially appearing peak is equal to or greater than the second predetermined threshold value.

9. A control method of an optical disc apparatus which is capable of reading out information stored in an optical disc medium of a first type and another optical disc medium of a second type and includes

an optical pickup radiating light having a first wavelength provided for said optical disc medium of said first type and light having a second wavelength which is smaller than said first wavelength and provided for said optical disc medium of said second type; and

a signal outputting section outputting an output signal according to reflected light obtained as a result of reflection on said optical disc medium of light radiated by said optical pickup,

said method comprising:

requesting said optical pickup to radiate light having said first wavelength to an object optical disc medium serving as an object of type determination to acquire an output signal output by said signal outputting section while moving said optical pickup in a direction to said object optical disc medium; and

determining the type of said object optical disc medium based on the number of detected peaks appearing in said acquired output signal;

wherein said method comprises, while moving said optical pickup in a direction approaching said object optical disc medium, requesting said optical pickup to radiate light having said first wavelength to said object optical disc medium to acquire an output signal output by said signal outputting section and determining the type of optical disc medium based on comparing a peak initially appearing in said acquired output signal to a first predetermined threshold value and a second predetermined threshold value, the second predetermined threshold value being substantially greater than the first predetermined threshold value.

10. A microprocessor operating under the control of an executable program for controlling an optical disc apparatus which is capable of reading out information stored in an optical disc medium of a first type and another optical disc medium of a second type and includes

an optical pickup radiating light having a first wavelength provided for said optical disc medium of said first type and light having a second wavelength which is smaller than said first wavelength and provided for said optical disc medium of said second type; and

a signal outputting section outputting an output signal according to reflected light obtained as a result of reflection on said optical disc medium of light radiated by said optical pickup,

said program for a computer comprising:

requesting said optical pickup to radiate light having said first wavelength to an object optical disc medium serving as an object of type determination to acquire an output signal output by said signal outputting section while moving said optical pickup in a direction to said object optical disc medium; and

determining the type of said object optical disc medium based on the number of detected peaks appearing in said acquired output signal;

wherein said program comprises, while moving said optical pickup in a direction approaching said object optical disc medium, requesting said optical pickup to radiate light having said first wavelength to said object optical disc medium to acquire an output signal output by said signal outputting section and determining the type of optical disc medium based on comparing a peak initially appearing in said acquired output signal to a first predetermined threshold value and a second predetermined threshold value, the second predetermined threshold value being substantially greater than the first predetermined threshold value.

11. A non-transitory information storage medium which can be read by a computer and is used for storing a program for controlling an optical disc apparatus which is capable of reading out information stored in an optical disc medium of a first type and another optical disc medium of a second type and includes

an optical pickup radiating light having a first wavelength provided for said optical disc medium of said first type and light having a second wavelength which is smaller than said first wavelength and provided for said optical disc medium of said second type; and

a signal outputting section outputting an output signal according to reflected light obtained as a result of reflection on said optical disc medium of light radiated by said optical pickup,

said program for the computer comprising:

requesting said optical pickup to radiate light having said first wavelength to an object optical disc medium serving as an object of type determination to acquire an output signal output by said signal outputting section while moving said optical pickup in a direction to said object optical disc medium; and

determining the type of said object optical disc medium based on the number of detected peaks appearing in said acquired output signal;

wherein said program comprises, while moving said optical pickup in a direction approaching said object optical disc medium, requesting said optical pickup to radiate light having said first wavelength to said object optical disc medium to acquire an output signal output by said signal outputting section and determining the type of optical disc medium based on comparing a peak initially appearing in said acquired output signal to a first predetermined threshold value and a second predetermined threshold value, the second predetermined threshold value being substantially greater than the first predetermined threshold value.