Optical head, an optical disk device and an integrated circuit

An optical head, comprising a light source, an objective lens for concentrating a laser beam emitted from the light source onto information tracks of an optical disk, and a light sensing device for sensing a luminous flux reflected by information tracks, wherein:

• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks, a first and a second partition lines symmetrically arranged with respect to the vertical dividing line while being distanced from the vertical dividing line, a third partition line arranged between the vertical dividing line and the first partition line, a fourth partition line symmetrically arranged with the third partition line with respect to the optical axis between the vertical dividing line and the second partition line,
• each of the first and second partition lines includes a pair of horizontal lines normal to the vertical dividing line, and an inner line connecting ends of the horizontal lines toward the vertical dividing line,
• each of the third and fourth partition lines includes a pair of horizontal lines normal to the vertical dividing line, and an inner line connecting ends of the horizontal lines toward the vertical dividing line,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line, a region at a side of the optical axis opposite from the third partition line being divided into an A5 region at a side toward the third partition line and a remaining A1 region by the first partition line, and a region at a side of the optical axis opposite from the fourth partition line being divided into a B5 region at a side toward the fourth partition line and a remaining B1 region by the second partition line,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A5 region and the B5 region are symmetrically arranged with respect to the vertical dividing line, and
• the optical head further comprises a tilt detector for detecting a relative tilt of the objective lens and the optical disk in accordance with a luminous energy incident on the luminous flux incident area of the light sensing device.

An optical head, comprising a light source, an objective lens for concentrating a laser beam emitted from the light source onto information tracks of an optical disk, and a light sensing device for sensing a luminous flux reflected by information tracks, wherein:

• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks, straight first and second horizontal dividing lines normal to the vertical dividing line and symmetrically arranged with respect to the optical axis, a third and a fourth horizontal dividing lines at a distance to and parallel with the horizontal dividing lines in one region partitioned by the vertical dividing line between the first and second horizontal dividing lines, a fifth and a sixth horizontal dividing lines at a distance to and parallel with the horizontal dividing lines in the other region partitioned by the vertical dividing line, a seventh and an eighth horizontal dividing lines arranged at sides of the first and second horizontal dividing lines opposite from the optical axis, in parallel with the first and second horizontal dividing lines and symmetrically with respect to the optical axis,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line between the first and second horizontal dividing lines,
• a region between the first and second horizontal dividing lines in the one region partitioned by the vertical dividing line is divided into an A1 region between the third and fourth horizontal dividing lines and remaining A7 regions,
• a region between the first and second horizontal dividing lines in the other region partitioned by the vertical dividing line is divided into a B1 region between the fifth and sixth horizontal dividing lines and remaining B7 regions,
• regions at sides of the seventh and eighth horizontal dividing lines opposite from the optical axis are defined as N2 regions,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A7 region and the B7 region are symmetrically arranged with respect to the vertical dividing line, and
• the optical head further comprises a tilt detector for detecting a relative tilt of the objective lens and the optical disk in accordance with a luminous energy incident on the luminous flux incident area of the light sensing device.

An optical head, comprising a light source, an objective lens for concentrating a laser beam emitted from the light source onto information tracks of an optical disk, and a light sensing device for sensing a luminous flux reflected by information tracks, wherein:

• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks;
• a pair of first horizontal dividing lines normal to the vertical dividing line and symmetrically arranged with respect to the vertical dividing line;
• a pair of second horizontal dividing lines parallel with the pair of first horizontal dividing lines and symmetrically arranged with respect to the vertical dividing line;
• a third and a fourth horizontal dividing lines at a distance to and parallel with the first and second horizontal dividing lines in one region partitioned by the vertical dividing line between the first and second horizontal dividing lines;
• a fifth and a sixth horizontal dividing lines at a distance to and parallel with the first and second horizontal dividing lines in the other region partitioned by the vertical dividing line between the first and second horizontal dividing lines;
• a first inner line extending in parallel with the vertical dividing line and connecting inner ends of the first horizontal dividing line at one side, the third horizontal dividing line, the fourth horizontal dividing line and the second horizontal dividing line at one side;
• a second inner line extending in parallel with the vertical dividing line and connecting inner ends the first horizontal dividing line at the other side, the fifth horizontal dividing line, the sixth horizontal dividing line and the second horizontal dividing line at the other side;
• and seventh and eighth horizontal dividing lines arranged at sides of the first and second horizontal dividing lines opposite from the optical axis, in parallel with the first and second horizontal dividing lines and symmetrically with respect to the optical axis,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line between the first and second inner lines,
• a region defined by the first horizontal dividing line, the second horizontal dividing line and the first inner line in the one region partitioned by the vertical dividing line is divided into an A1 region between the third and fourth horizontal dividing lines and remaining A7 regions,
• a region defined by the first horizontal dividing line, the second horizontal dividing line and the second inner line in the other region partitioned by the vertical dividing line is divided into a B1 region between the fifth and sixth horizontal dividing lines and remaining B7 regions,
• regions at sides of the seventh and eighth horizontal dividing lines opposite from the optical axis are defined as N2 regions,
• the pair of first horizontal dividing lines and the pair of second horizontal dividing lines are symmetrically arranged with respect to the optical axis,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A7 region and the B7 region are symmetrically arranged with respect to the vertical dividing line, and
• the optical head further comprises a tilt detector for detecting a relative tilt of the objective lens and the optical disk in accordance with a luminous energy incident on the luminous flux incident area of the light sensing device.

An optical disk device, comprising:

• an optical head including a light source, an objective lens for concentrating a laser beam emitted from the light source onto information tracks of an optical disk, and a light sensing device for sensing a luminous flux reflected by information tracks,
• an optical disk driver for driving the optical disk, and
• a controller for controlling the optical head and the optical disk driver,
• wherein:
• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks, straight first and second horizontal dividing lines normal to the vertical dividing line and symmetrically arranged with respect to the optical axis, a first and a second partition lines symmetrically arranged between the two horizontal dividing lines with respect to the vertical dividing line while being distanced from the vertical dividing line and the two horizontal dividing lines,
• each of the first and second partition lines includes a pair of horizontal lines parallel with the two horizontal dividing lines, and an inner line connecting ends of the horizontal lines toward the vertical dividing line,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line between the two horizontal dividing lines, one region partitioned between the two horizontal dividing lines by the vertical dividing line being divided into an A2 region at a side toward the optical axis and a remaining A1 region by the first partition line, and the other region partitioned between the two horizontal dividing lines by the vertical dividing line being divided into a B2 region at a side toward the optical axis and a remaining B1 region by the second partition line,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A2 region and the B2 region are symmetrically arranged with respect to the vertical dividing line, and
• the optical head further comprises a tilt detector for detecting a relative tilt of the objective lens and the optical disk in accordance with a luminous energy incident on the luminous flux incident area of the light sensing device.

An optical disk device, comprising:

• an optical head including a light source, an objective lens for concentrating a laser beam emitted from the light source onto information tracks of an optical disk, and a light sensing device for sensing a luminous flux reflected by information tracks,
• an optical disk driver for driving the optical disk, and
• a controller for controlling the optical head and the optical disk driver,
• wherein:
• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks, a first and a second partition lines symmetrically arranged with respect to the vertical dividing line while being distanced from the vertical dividing line, a third partition line arranged between the vertical dividing line and the first partition line, a fourth partition line symmetrically arranged with the third partition line with respect to the optical axis between the vertical dividing line and the second partition line,
• each of the first and second partition lines includes a pair of horizontal lines normal to the vertical dividing line, and an inner line connecting ends of the horizontal lines toward the vertical dividing line,
• each of the third and fourth partition lines includes a pair of horizontal lines normal to the vertical dividing line, and an inner line connecting ends of the horizontal lines toward the vertical dividing line,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line, a region at a side of the third partition line opposite from the optical axis being divided into an A5 region at a side toward the third partition line and a remaining A1 region by the first partition line, and a region at a side of the fourth partition line opposite from the optical axis being divided into a B5 region at a side toward the fourth partition line and a remaining B1 region by the second partition line,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A5 region and the B5 region are symmetrically arranged with respect to the vertical dividing line, and
• the optical head further comprises a tilt detector for detecting a relative tilt of the objective lens and the optical disk in accordance with a luminous energy incident on the luminous flux incident area of the light sensing device.

An optical disk device, comprising:

• an optical head including a light source, an objective lens for concentrating a laser beam emitted from the light source onto information tracks of an optical disk, and a light sensing device for sensing a luminous flux reflected by information tracks,
• an optical disk driver for driving the optical disk, and
• a controller for controlling the optical head and the optical disk driver,
• wherein:
• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks, straight first and second horizontal dividing lines normal to the vertical dividing line and symmetrically arranged with respect to the optical axis, a third and a fourth horizontal dividing lines at a distance to and parallel with the horizontal dividing lines in one region partitioned by the vertical dividing line between the first and second horizontal dividing lines, a fifth and a sixth horizontal dividing lines at a distance to and parallel with the horizontal dividing lines in the other region partitioned by the vertical dividing line between the first and second horizontal dividing lines, a seventh and an eighth horizontal dividing lines arranged at sides of the first and second horizontal dividing lines opposite from the optical axis, in parallel with the first and second horizontal dividing lines and symmetrically with respect to the optical axis,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line between the first and second horizontal dividing lines,
• a region between the first and second horizontal dividing lines in the one region partitioned by the vertical dividing line is divided into an A1 region between the third and fourth horizontal dividing lines and remaining A7 regions,
• a region between the first and second horizontal dividing lines in the other region partitioned by the vertical dividing line is divided into a B1 region between the fifth and sixth horizontal dividing lines and remaining B7 regions,
• regions at sides of the seventh and eighth horizontal dividing lines opposite from the optical axis are defined as N2 regions,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A7 region and the B7 region are symmetrically arranged with respect to the vertical dividing line, and
• the optical head further comprises a tilt detector for detecting a relative tilt of the objective lens and the optical disk in accordance with a luminous energy incident on the luminous flux incident area of the light sensing device.

An optical disk device, comprising:

• an optical head including a light source, an objective lens for concentrating a laser beam emitted from the light source onto information tracks of an optical disk, and a light sensing device for sensing a luminous flux reflected by information tracks,
• an optical disk driver for driving the optical disk, and
• a controller for controlling the optical head and the optical disk driver,
• wherein:
• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks;
• a pair of first horizontal dividing lines normal to the vertical dividing line and symmetrically arranged with respect to the vertical dividing line;
• a pair of second horizontal dividing lines parallel with the pair of first horizontal dividing lines and symmetrically arranged with respect to the vertical dividing line;
• a third and a fourth horizontal dividing lines at a distance to and parallel with the first and second horizontal dividing lines in one region partitioned by the vertical dividing line between the first and second horizontal dividing lines;
• a fifth and a sixth horizontal dividing lines at a distance to and parallel with the first and second horizontal dividing lines in the other region partitioned by the vertical dividing line between the first and second horizontal dividing lines;
• a first inner line extending in parallel with the vertical dividing line and connecting inner ends of the first horizontal dividing line at one side, the third horizontal dividing line, the fourth horizontal dividing line and the second horizontal dividing line at one side;
• a second inner line extending in parallel with the vertical dividing line and connecting inner ends the first horizontal dividing line at the other side, the fifth horizontal dividing line, the sixth horizontal dividing line and the second horizontal dividing line at the other side;
• and seventh and eighth horizontal dividing lines arranged at sides of the first and second horizontal dividing lines opposite from the optical axis, in parallel with the first and second horizontal dividing lines and symmetrically with respect to the optical axis,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line between the first and second inner lines,
• a region defined by the first horizontal dividing line, the second horizontal dividing line and the first inner line in the one region partitioned by the vertical dividing line is divided into an A1 region between the third and fourth horizontal dividing lines and remaining A7 regions,
• a region defined by the first horizontal dividing line, the second horizontal dividing line and the second inner line in the other region partitioned by the vertical dividing line is divided into a B1 region between the fifth and sixth horizontal dividing lines and remaining B7 regions,
• regions at sides of the seventh and eighth horizontal dividing lines opposite from the optical axis are defined as N2 regions,
• the pair of first horizontal dividing lines and the pair of second horizontal dividing lines are symmetrically arranged with respect to the optical axis,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A7 region and the B7 region are symmetrically arranged with respect to the vertical dividing line, and
• the optical head further comprises a tilt detector for detecting a relative tilt of the objective lens and the optical disk in accordance with a luminous energy incident on the luminous flux incident area of the light sensing device.

An integrated circuit for deriving a tilt signal corresponding to a relative tilt of an objective lens and an optical disk in accordance with a signal from a light sensing device of an optical head for concentrating a laser beam emitted from a light source onto information tracks of the optical disk by means of the objective lens and sensing a luminous flux reflected by the information tracks by means of the light sensing device,

• wherein:
• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks, straight first and second horizontal dividing lines normal to the vertical dividing line and symmetrically arranged with respect to the optical axis, a first and a second partition lines symmetrically arranged between the two horizontal dividing lines with respect to the vertical dividing line while being distanced from the vertical dividing line and the two horizontal dividing lines,
• each of the first and second partition lines includes a pair of horizontal lines parallel with the two horizontal dividing lines, and an inner line connecting ends of the horizontal lines toward the vertical dividing line,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line between the two horizontal dividing lines, one region partitioned between the two horizontal dividing lines by the vertical dividing line being divided into an A2 region at a side toward the optical axis and a remaining A1 region by the first partition line, and the other region partitioned between the two horizontal dividing lines by the vertical dividing line being divided into a B2 region at a side toward the optical axis and a remaining B1 region by the second partition line,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A2 region and the B2 region are symmetrically arranged with respect to the vertical dividing line, and
• a difference signal between a first difference signal, which is a difference signal between a signal obtained from the A1 region of the light sensing device and a signal obtained from the B1 region of the light sensing device, and a second difference signal, which is a difference signal between a signal obtained from the A2 region of the light sensing device and a signal obtained from the B2 region of the light sensing device, is generated after multiplying at least one of the first and second difference signals by a specified weight coefficient, and the tilt signal is derived in accordance with the generated difference signal.

An integrated circuit for deriving a tilt signal corresponding to a relative tilt of an objective lens and an optical disk in accordance with a signal from a light sensing device of an optical head for concentrating a laser beam emitted from a light source onto information tracks of the optical disk by means of the objective lens and sensing a luminous flux reflected by the information tracks by means of the light sensing device,

• wherein:
• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks, a first and a second partition lines symmetrically arranged with respect to the vertical dividing line while being distanced from the vertical dividing line, a third partition line arranged between the vertical dividing line and the first partition line, a fourth partition line symmetrically arranged with the third partition line with respect to the optical axis between the vertical dividing line and the second partition line,
• each of the first and second partition lines includes a pair of horizontal lines normal to the vertical dividing line, and an inner line connecting ends of the horizontal lines toward the vertical dividing line,
• each of the third and fourth partition lines includes a pair of horizontal lines normal to the vertical dividing line, and an inner line connecting ends of the horizontal lines toward the vertical dividing line,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line, a region at a side of the third partition line opposite from the optical axis being divided into an A5 region at a side toward the third partition line and a remaining A1 region by the first partition line, and a region at a side of the fourth partition line opposite from the optical axis being divided into a B5 region at a side toward the fourth partition line and a remaining B1 region by the second partition line,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A5 region and the B5 region are symmetrically arranged with respect to the vertical dividing line, and
• a difference signal between a first difference signal, which is a difference signal between a signal obtained from the A1 region of the light sensing device and a signal obtained from the B1 region of the light sensing device, and a second difference signal, which is a difference signal between a signal obtained from the A5 region of the light sensing device and a signal obtained from the B5 region of the light sensing device, is generated after multiplying at least one of the first and second difference signals by a specified weight coefficient, and the tilt signal is derived in accordance with the generated difference signal.

An integrated circuit for deriving a tilt signal corresponding to a relative tilt of an objective lens and an optical disk in accordance with a signal from a light sensing device of an optical head for concentrating a laser beam emitted from a light source onto information tracks of the optical disk by means of the objective lens and sensing a luminous flux reflected by the information tracks by means of the light sensing device,

• wherein:
• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks, straight first and second horizontal dividing lines normal to the vertical dividing line and symmetrically arranged with respect to the optical axis, a third and a fourth horizontal dividing lines at a distance to and parallel with the horizontal dividing lines in one region partitioned by the vertical dividing line between the first and second horizontal dividing lines a fifth and a sixth horizontal dividing lines at a distance to and parallel with the horizontal dividing lines in the other region partitioned by the vertical dividing line between the first and second horizontal dividing lines, a seventh and an eighth horizontal dividing lines arranged at sides of the first and second horizontal dividing lines opposite from the optical axis, in parallel with the first and second horizontal dividing lines and symmetrically with respect to the optical axis,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line between the first and second horizontal dividing lines,
• a region between the first and second horizontal dividing lines in the one region partitioned by the vertical dividing line is divided into an A1 region between the third and fourth horizontal dividing lines and remaining A7 regions,
• a region between the first and second horizontal dividing lines in the other region partitioned by the vertical dividing line is divided into a B1 region between the fifth and sixth horizontal dividing lines and remaining B7 regions,
• regions at sides of the seventh and eighth horizontal dividing lines opposite from the optical axis are defined as N2 regions,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A7 region and the B7 region are symmetrically arranged with respect to the vertical dividing line, and
• a difference signal between a first difference signal, which is a difference signal between a signal obtained from the A1 region of the light sensing device and a signal obtained from the B1 region of the light sensing device, and a second difference signal, which is a difference signal between a signal obtained from the A7 region of the light sensing device and a signal obtained from the B7 region of the light sensing device, is generated after multiplying at least one of the first and second difference signals by a specified weight coefficient, and the tilt signal is derived in accordance with the generated difference signal.

An integrated circuit for deriving a tilt signal corresponding to a relative tilt of an objective lens and an optical disk in accordance with a signal from a light sensing device of an optical head for concentrating a laser beam emitted from a light source onto information tracks of the optical disk by means of the objective lens and sensing a luminous flux reflected by the information tracks by means of the light sensing device,

• wherein:
• the light sensing device includes a luminous flux incident area divided into a plurality of regions by a straight vertical dividing line passing an optical axis of the objective lens and parallel with a direction tangent to the information tracks;
• a pair of first horizontal dividing lines normal to the vertical dividing line and symmetrically arranged with respect to the vertical dividing line;
• a pair of second horizontal dividing lines parallel with the pair of first horizontal dividing lines and symmetrically arranged with respect to the vertical dividing line;
• a third and a fourth horizontal dividing lines at a distance to and parallel with the first and second horizontal dividing lines in one region partitioned by the vertical dividing line between the first and second horizontal dividing lines;
• a fifth and a sixth horizontal dividing lines at a distance to and parallel with the first and second horizontal dividing lines in the other region partitioned by the vertical dividing line between the first and second horizontal dividing lines;
• a first inner line extending in parallel with the vertical dividing line and connecting inner ends of the first horizontal dividing line at one side, the third horizontal dividing line, the fourth horizontal dividing line and the second horizontal dividing line at one side;
• a second inner line extending in parallel with the vertical dividing line and connecting inner ends the first horizontal dividing line at the other side, the fifth horizontal dividing line, the sixth horizontal dividing line and the second horizontal dividing line at the other side;
• and seventh and eighth horizontal dividing lines arranged at sides of the first and second horizontal dividing lines opposite from the optical axis, in parallel with the first and second horizontal dividing lines and symmetrically with respect to the optical axis,
• the luminous flux incident area further includes an N region crossing over the vertical dividing line between the first and second inner lines,
• a region defined by the first horizontal dividing line, the second horizontal dividing line and the first inner line in the one region partitioned by the vertical dividing line is divided into an A1 region between the third and fourth horizontal dividing lines and remaining A7 regions,
• a region defined by the first horizontal dividing line, the second horizontal dividing line and the second inner line in the other region partitioned by the vertical dividing line is divided into a B1 region between the fifth and sixth horizontal dividing lines and remaining B7 regions,
• regions at sides of the seventh and eighth horizontal dividing lines opposite from the optical axis are defined as N2 regions,
• the pair of first horizontal dividing lines and the pair of second horizontal dividing lines are symmetrically arranged with respect to the optical axis,
• the A1 region and the B1 region are symmetrically arranged with respect to the vertical dividing line,
• the A7 region and the B7 region are symmetrically arranged with respect to the vertical dividing line, and
• a difference signal between a first difference signal, which is a difference signal between a signal obtained from the A1 region of the light sensing device and a signal obtained from the B1 region of the light sensing device, and a second difference signal, which is a difference signal between a signal obtained from the A7 region of the light sensing device and a signal obtained from the B7 region of the light sensing device, is generated after multiplying at least one of the first and second difference signals by a specified weight coefficient, and the tilt signal is derived in accordance with the generated difference signal.