Information recording medium, and method and apparatus for recording a signal thereon

A method of recording a signal on a disc-shaped information recording medium comprising a plurality of recording layers on and from which an information signal and a test signal can be optically recorded and reproduced while a laser beam emitted from an optical pickup is applied to the recording layers through one side of the medium, the recording layers including a first recording layer and a second recording layer which is remoter from the optical pickup than the first recording layer is, the method comprising the steps of:

• a) modulating the laser beam in accordance with the test signal;
• b) allowing the modulated laser beam to scan the first recording layer along a first scanning direction and scan the second recording layer along a second scanning direction opposite to the first scanning direction, and thereby recording the test signal on the first recording layer and the second recording layer in a manner such that the first recording layer and the second recording layer will have respective optical recording test areas storing the recorded test signal, and the optical recording test areas will be out of overlap as viewed in a direction of propagation of the modulated laser beam, and that the first recording layer and the second recording layer will have a gap region which is located between the optical recording test areas as viewed in the direction of propagation of the modulated laser beam, and which is void of the recorded test signal.

A method of recording a signal on a disc-shaped information recording medium comprising a plurality of recording layers on and from which an information signal and a test signal can be optically recorded and reproduced while a laser beam emitted from an optical pickup is applied to the recording layers through one side of the medium, the recording layers including a first recording layer and a second recording layer which is remoter from the optical pickup than the first recording layer is, the method comprising the steps of:

• a) modulating the laser beam in accordance with the test signal;
• b) applying the modulated laser beam to the first recording layer and the second recording layer and thereby recording the test signal on the first recording layer and the second recording layer in a manner such that the first recording layer and the second recording layer will have respective optical recording test areas storing the recorded test signal, and the optical recording test areas will be out of overlap as viewed in a direction of propagation of the modulated laser beam, and that the first recording layer and the second recording layer will have a gap region which is located between the optical recording test areas as viewed in the direction of propagation of the modulated laser beam, and which is void of the recorded test signal;
• c) reproducing the test signal from the optical recording test area in the first recording layer;
• d) deciding a first optimum power value of a laser beam for signal recording on the first recording layer in response to the test signal reproduced from the optical recording test area in the first recording layer;
• e) reproducing the test signal from the optical recording test area in the second recording layer;
• f) deciding a second optimum power value of a laser beam for signal recording on the second recording layer in response to the test signal reproduced from the optical recording test area in the second recording layer;
• g) recording first data on the first recording layer by using a laser beam having the decided first optimum power value;
• and
• h) recording second data on the second recording layer by using a laser beam having the decided second optimum power value.

A disc-shaped information recording medium comprising:

• a laminate of a plurality of recording layers on and from which an information signal can be optically recorded and reproduced, the recording layers including a first recording layer (L0) and a second recording layer (L1);
• data areas provided in the first recording layer (L0) and the second recording layer (L1) respectively, the information signal being optically recordable on the data areas through the use of a laser beam;
• recording management areas provided in the first recording layer (L0) and the second recording layer (L1) respectively and located inward of the data areas, the recording management areas being for management of recording;
• optical recording test areas provided in the first recording layer (L0) and the second recording layer (L1) respectively and being out of overlap with each other as viewed in a direction perpendicular to the recording layers, a test signal being recordable on the optical test areas for deciding optimum power values of the laser beam;
• a BCA area provided in the first recording layer (L0), management information for recording or reproduction being previously recorded on the BCA area as a bar code;
• and
• a control data area provided in the first recording layer (L0) for control of recording or reproduction.