US 8,077,582 B2 · Optical pickup, optical information recording method, and optical disc apparatus

Abstract

The recording accuracy of information on an optical disc is increased. An information optical system (150) of an optical disc apparatus (110) enables a semiconductor laser (3) to sequentially output specific peak light (LEP) and specific slope light (LES) as an information light beam (LM) and enables the correction lens (162) to change the divergence angle of the specific peak light (LEP) so that an absorption change area (RA) by the specific peak light (LEP) can be positioned at a far position in the recording layer (101). Thus, it is possible to form an energy concentration area (RE) by the specific slope light (LES) in the vicinity of a target position (QG), and the recording accuracy of information on the optical disc (100) can be increased.

Claims20

Dependent claims

An optical pickup comprising:

a semiconductor laser to sequentially emit, as laser light, specific peak light having first light intensity characteristics in a pulse shape and specific slope light having second light intensity characteristics in a slope shape, the specific slope light having a light intensity lower than the specific peak light and a wavelength differing from that of the specific peak light, when a driving pulse in a pulse shape and at a predetermined specific voltage is supplied;
a divergence angle differing unit to cause axes or divergence angles in the specific peak light and the specific slope light to differ from each other in accordance with the wavelength of the laser light;
and
an objective lens to form, in a recording layer of an optical disc, a recording mark by collecting the specific peak light so as to cause a first reaction to occur in a first area in a vicinity of a focal point thereof and thereafter by collecting the specific slope light at a same focus position as that of the specific peak light so as to cause a second reaction to occur in a second area in which the specific slope light is irradiated within the first area in which the first reaction has occurred.

1 more element

An optical pickup comprising:

a semiconductor laser to sequentially emit, as laser light, specific peak light having first light intensity characteristics in a pulse shape and specific slope light having second light intensity characteristics in a slope shape, the specific slope light having a light intensity lower than the specific peak light and a wavelength differing from that of the specific peak light, when a driving pulse in a pulse shape and at a predetermined specific voltage is supplied;
a divergence angle differing unit to cause divergence angles in the specific peak light and the specific slope light to differ from each other in accordance with the wavelength of the laser light;
and
an objective lens to form, in a recording layer of an optical disc, a recording mark by collecting the specific peak light so as to cause a first reaction to occur in a first area in a vicinity of a focal point thereof and thereafter by collecting the specific slope light at a same focus position as that of the specific peak light so as to cause a second reaction to occur in a second area in which the specific slope light is irradiated within the first area in which the first reaction has occurred,
wherein the divergence angle differing unit causes the divergence angles of the specific peak light and the specific slope light to differ from each other so that the first reaction is made to occur in a range containing the focal point of the specific slope light with a position away from the focal point being the center in the recording layer.

2 more elements

An optical pickup comprising:

a semiconductor laser to sequentially emit, as laser light, specific peak light having first light intensity characteristics in a pulse shape and specific slope light having second light intensity characteristics in a slope shape, the specific slope light having a light intensity lower than the specific peak light and a wavelength differing from that of the specific peak light, when a driving pulse in a pulse shape and at a predetermined specific voltage is supplied;
a divergence angle differing unit to cause divergence angles in the specific peak light and the specific slope light to differ from each other in accordance with the wavelength of the laser light;
and
an objective lens to form, in a recording layer of an optical disc, a recording mark by collecting the specific peak light so as to cause a first reaction to occur in a first area in a vicinity of a focal point and thereafter by collecting the specific slope light at the same focus position as that of the specific peak light so as to cause a second reaction to occur in a second area in which the first reaction has occurred.

1 more element

An optical disc apparatus comprising:

a semiconductor laser to sequentially emit, as laser light, specific peak light having first light intensity characteristics in a pulse shape and specific slope light having second light intensity characteristics in a slope shape, the specific slope light having a light intensity lower than the specific peak light and a wavelength differing from that of the specific peak light, when a driving pulse in a pulse shape and at a predetermined specific voltage is supplied;
a laser light separation unit to separate an optical axis of the specific peak light from the optical axis of the specific slope light in accordance with a wavelength of the laser light;
and
an objective lens to form, in a recording layer of an optical disc, a recording mark by collecting the specific peak light so as to cause a first reaction to occur in a first area in a vicinity of a focal point of the specific peak light and thereafter by collecting the specific slope light so as to cause a second reaction to occur in a portion in which the specific slope light is collected in the first area in which the first reaction has occurred,
wherein the laser light separation unit separates the optical axis of the specific peak light and the optical axis of the specific slope light from each other so that a light collection area of the specific slope light is made to partially overlap with the first area in which the first reaction has occurred in the recording layer.

2 more elements

Dependencies are inferred from the claim text.

Optical pickup, optical information recording method, and optical disc apparatus

Life of this patent

Optical pickup, optical information recording method, and optical disc apparatus

Life of this patent

Abstract

Claims20