Focus jump control apparatus of a player for multilayer recording disc

A focus jump control apparatus comprising:

• reading means for irradiating read light to a disc having information recording surfaces formed on at least two layers, respectively;
• a focusing servo loop for allowing an optimum light converging position of said read light to trace said recording surface in accordance with a focusing error signal generated based on return light from said disc by using a focusing actuator for displacing the optimum light converging position of said read light in the optical axial direction;
• a tracking servo loop for allowing the optimum light converging position of said read light to trace tracks formed on said disc;
• and
• loop opening/closing control means for opening said focusing servo loop in response to an instruction and for closing said focusing servo loop when a movement of the optimum light converging position of said read light from one of said recording surfaces to the other is finished, wherein a closed state of said tracking servo loop is maintained for a predetermined period of time until a first timing during the movement of the optimum light converging position of said read light, and said tracking servo loop is opened subsequently.

A focus jump control apparatus comprising:

• reading means for irradiating read light to a disc having information recording surfaces formed on at least two layers, respectively;
• a focusing servo loop for allowing an optimum light converging position of said read light to trace said recording surface in accordance with a focusing error signal generated based on return light from said disc by using a focusing actuator for displacing the optimum light converging position of said read light in the optical axial direction;
• a tracking servo loop for allowing the optimum light converging position of said read light to trace tracks formed on said disc;
• and
• selecting means for selecting either one of a tracking servo continuation type focus jumping operation and a tracking servo temporary intermittent type focus jumping operation as an operation to be executed in a jumping mode,
• wherein said tracking servo continuation type focus jumping operation is the operation for opening said focusing servo loop in response to an instruction, for closing said focusing servo loop when a movement of the optimum light converging position of said read light from one of said recording surfaces to the other is finished, and for maintaining the closing state of said tracking servo loop during the movement of the optimum light converging position of said read light, and
• said tracking servo temporary intermittent type focus jumping operation is the operation for opening said focusing servo loop in response to an instruction, for closing said focusing servo loop when the movement of the optimum light converging position of said read light from one of said recording surfaces to the other is finished, for maintaining the closing state of said tracking servo loop for a predetermined period of time until a first timing during the movement of the optimum light converging position of said read light, and for subsequently opening said tracking servo loop.