Abstract: An information recording device including a controller records information in a write-once optical disk group including one or a plurality of write-once optical disks. When recording new data, the controller calculates a residual quantity of an alternate area. The calculation of the residual quantity of the alternate area corresponds to a subtraction of a first consumption size and a second consumption size from a size of the alternate area of the write-once optical disk group. The first consumption size is a size of the alternate area already consumed when the data recorded in the write-once optical disk group was erased. The second consumption size is an estimated size of the alternate area to be consumed when the data recorded in the write-once optical disk group is erased. The controller records the new data when the residual quantity is greater than or equal to a third consumption size.

Abstract: An information recording device including a controller records information in a write-once optical disk group including one or a plurality of write-once optical disks. When recording new data, the controller calculates a residual quantity of an alternate area. The calculation of the residual quantity of the alternate area corresponds to a subtraction of a first consumption size and a second consumption size from a size of the alternate area of the write-once optical disk group. The first consumption size is a size of the alternate area already consumed when the data recorded in the write-once optical disk group was erased. The second consumption size is an estimated size of the alternate area to be consumed when the data recorded in the write-once optical disk group is erased. The controller records the new data when the residual quantity is greater than or equal to a third consumption size.

Abstract: A highly reliable optical pickup which is not likely to collide with an optical disk is provided. Relative positions of two objective lenses 100 and 101 (along a focus direction) on a lens holder 102 are determined so that, while the objective lens 101 having a longer working distance is focused on an optical disk 200, the objective lens 100 having a shorter working distance and a protective member 103 are at positions which are more distant from the optical disk 200 than a height h of a protrusion which is present in an inner peripheral region of the optical disk optical disk 200.

Abstract: An optical disk device of the present application includes: a turntable 30 including plural induction grooves 31a to 31h as concave portions radially extending from vicinity of a center of the turntable 30 and having open portions in an outer periphery of the turntable 30 and plural through-holes 32a to 32h penetrating bottom faces 33a to 33h on the vicinity of the center side of the plural induction grooves 31a to 31h and a top face of the turntable 30; and an outer rotor type spindle motor 35 provided with plural fins 36a to 36h as convex portions on a rotor on a side face thereof. The optical disk device of the present application utilizes an airflow generated by rotation of the rotor of the spindle motor 35 and the turntable 30 in conjunction therewith as a dust removing wind for removing dust attaching to an objective lens side area.

Abstract: An optical disk device of the present application includes: a turntable 30 including plural induction grooves 31a to 31h as concave portions radially extending from vicinity of a center of the turntable 30 and having open portions in an outer periphery of the turntable 30 and plural through-holes 32a to 32h penetrating bottom faces 33a to 33h on the vicinity of the center side of the plural induction grooves 31a to 31h and a top face of the turntable 30; and an outer rotor type spindle motor 35 provided with plural fins 36a to 36h as convex portions on a rotor on a side face thereof. The optical disk device of the present application utilizes an airflow generated by rotation of the rotor of the spindle motor 35 and the turntable 30 in conjunction therewith as a dust removing wind for removing dust attaching to an objective lens side area.

Abstract: An optical pickup device 11 according to the present invention includes: a light source 1 that emits a light beam; a condensing element 5 for condensing the light beam toward an information storage medium 14; and a protruding member 101, which comes closer to the information storage medium 14 than the condensing element 5 does when the condensing element 5 faces the information storage medium 14. The protruding member 101 is shaped so as to gradually protrude toward the information storage medium 14 in a tangential direction 21 of the information storage medium 14 rotating.

Abstract: A highly reliable optical pickup which is not likely to collide with an optical disk is provided. Relative positions of two objective lenses 100 and 101 (along a focus direction) on a lens holder 102 are determined so that, while the objective lens 101 having a longer working distance is focused on an optical disk 200, the objective lens 100 having a shorter working distance and a protective member 103 are at positions which are more distant from the optical disk 200 than a height h of a protrusion which is present in an inner peripheral region of the optical disk optical disk 200.