Abstract: An optical read/write apparatus as an embodiment of the present invention includes: a light-splitting element configured to split a light beam emitted from a light source into multiple light beams including a write beam and a read beam; an optical system configured to converge the write and read beams onto the same track on an optical storage medium; a photodetector including a light receiving element configured to detect the read beam reflected from the optical storage medium and output an electrical signal; and a divider configured to generate a read signal by dividing the signal detected by the light receiving element by a signal that represents a write modulated component and that is obtained by detecting a part of the light beam emitted from the light source.

Abstract: An optical read/write apparatus as an embodiment of the present invention includes: a light-splitting element configured to split a light beam emitted from a light source into multiple light beams including a write beam and a read beam; an optical system configured to converge the write and read beams onto the same track on an optical storage medium; a photodetector including a light receiving element configured to detect the read beam reflected from the optical storage medium and output an electrical signal; and a divider configured to generate a read signal by dividing the signal detected by the light receiving element by a signal that represents a write modulated component and that is obtained by detecting a part of the light beam emitted from the light source.

Abstract: An optical read/write apparatus as an embodiment of the present invention includes: a light-splitting element configured to split a light beam emitted from a light source into multiple light beams including a write beam and a read beam; an optical system configured to converge the write and read beams onto the same track on an optical storage medium; a photodetector including a light receiving element configured to detect the read beam reflected from the optical storage medium and output an electrical signal; and a divider configured to generate a read signal by dividing the signal detected by the light receiving element by a signal that represents a write modulated component and that is obtained by detecting a part of the light beam emitted from the light source.

Abstract: An optical drive according to the present invention can write information on an optical disc, which includes a substrate on which a number of pre-pits (2) have been formed on its tracks (t1 to t8) and a recording film that is supported on the substrate. The optical drive includes an optical pickup, and a writing control section for controlling the optical pickup so that marks (3a, 3b) are recorded on the tracks (t1 to t8) so as to overlap with some of the pre-pits (2) and for making the optical pickup irradiate the recording film with a writing light beam. The recorded marks (3a, 3b) overlap with at least ten of the pre-pits (2).

Abstract: An optical disc drive according to the present invention includes an optical pickup and a writing control section for instructing the optical pickup to record a mark, representing the information to be written, on the optical disc. In recording the mark on the optical disc, the writing control section instructs the optical pickup to irradiate the same area on the optical disc with a light beam a plurality of times so that the mark is recorded in that repeatedly irradiated area.

Abstract: An optical disc drive according to the present invention can write information on an optical disc, which includes a substrate on which a number of pre-pits 2 have been formed on its tracks and a recording film that is supported on the substrate. The drive includes an optical pickup and a writing control section for controlling the optical pickup so that marks 3 are recorded so as to overlap with some of the pre-pits 2 on the tracks and for making the optical pickup irradiate the recording film with a writing light beam. The writing control section changes the interval of each pair of recorded marks that are adjacent to each other along the radius of the optical disc according to the optical power of the writing light beam. Thus, the optical disc drive of the present invention can record a mark on an optical disc on which pre-pits have already been formed even if the optical disc has a simplified structure.

Abstract: An optical disc drive according to the present invention writes information on an optical disc, which includes a substrate on which a number of pre-pits have been formed on its tracks and a recording film that is supported on the substrate. The optical disc drive includes a writing control section for instructing an optical pickup to record marks on the tracks by irradiating the recording film with a writing light beam. In accordance with information that defines, on the tracks, recordable areas Aa1 through Aa4 where the marks are recordable and pre-pit reading areas Ab1 through Ab4 where no marks are recordable, the writing control section controls the optical pickup so that the marks are recorded on at least some of the recordable areas. On the tracks on which the marks are recorded, each recordable area is shorter than any of the pre-pit reading areas.

Abstract: A thermal bonding conjugate fiber constituted from a first component comprising a polyester resin and a second component comprising a polyolefin resin with a melting point lower than that of the polyester resin by not less than 20° C., characterized in that a post-heat treatment bulk retention rate thereof is 20% or more when calculated by the following measurement method: Bulk retention rate=(H1 (mm)/H0 (mm))×100(%) (wherein H0 is the web height when a 0.1 g/cm2 load is applied to a web with a mass per unit area of 200 g/m2; and H1 is the web height after a heat treatment for 5 min at 145° C. when a 0.1 g/cm2 load is applied to that web).

Abstract: An optical drive according to the present invention can write information on an optical disc, which includes a substrate on which a number of pre-pits (2) have been formed on its tracks (t1 to t8) and a recording film that is supported on the substrate. The optical drive includes an optical pickup, and a writing control section for controlling the optical pickup so that marks (3a, 3b) are recorded on the tracks (t1 to t8) so as to overlap with some of the pre-pits (2) and for making the optical pickup irradiate the recording film with a writing light beam. The recorded marks (3a, 3b) overlap with at least ten of the pre-pits (2).

Abstract: An optical disc drive according to the present invention includes an optical pickup and a writing control section for instructing the optical pickup to record a mark, representing the information to be written, on the optical disc. In recording the mark on the optical disc, the writing control section instructs the optical pickup to irradiate the same area on the optical disc with a light beam a plurality of times so that the mark is recorded in that repeatedly irradiated area.

Abstract: An optical disc drive according to the present invention writes information on an optical disc, which includes a substrate on which a number of pre-pits have been formed on its tracks and a recording film that is supported on the substrate. The optical disc drive includes a writing control section for instructing an optical pickup to record marks on the tracks by irradiating the recording film with a writing light beam. In accordance with information that defines, on the tracks, recordable areas Aa1 through Aa4 where the marks are recordable and pre-pit reading areas Ab1 through Ab4 where no marks are recordable, the writing control section controls the optical pickup so that the marks are recorded on at least some of the recordable areas. On the tracks on which the marks are recorded, each recordable area is shorter than any of the pre-pit reading areas.

Abstract: An optical disc drive according to the present invention can write information on an optical disc, which includes a substrate on which a number of pre-pits 2 have been formed on its tracks and a recording film that is supported on the substrate. The drive includes an optical pickup and a writing control section for controlling the optical pickup so that marks 3 are recorded so as to overlap with some of the pre-pits 2 on the tracks and for making the optical pickup irradiate the recording film with a writing light beam. The writing control section changes the interval of each pair of recorded marks that are adjacent to each other along the radius of the optical disc according to the optical power of the writing light beam. Thus, the optical disc drive of the present invention can record a mark on an optical disc on which pre-pits have already been formed even if the optical disc has a simplified structure.

Abstract: An optical disk apparatus includes: an optical pickup unit for reading out information recorded on an optical disk; a demodulation circuit for demodulating digital data from an output signal of the optical pickup unit; and a controller for performing a servo control based on the output signal of the optical pickup unit. When performing a focus/tracking control in a recess and a protrusion of a guide groove of the optical disk, the controller obtains a focus control gain difference between the recess and the protrusion by comparing focus offsets with respect to variations in amplitudes of signals from the optical disk for the recess and the protrusion, respectively.

Abstract: An optical disc drive includes: at least one light source; an objective lens configured to focus the light that has been emitted from the at least one light source; a chromatic aberration compensation element, which is arranged on an optical path between the at least one light source and the objective lens in order to compensate for chromatic aberration that has been produced by the objective lens; and an actuator configured to change a position of the objective lens. The actuator changes the position of the objective lens in a tracking direction by a magnitude of an offset, which is determined by a variation in wavelength of the light to be produced when the power of the light emitted from the at least one light source changes.

Abstract: An optical disk apparatus according to the present invention includes: a rotation driving section on which an optical disk is to be mounted and which drives the optical disk so as to be rotated; a light source; an objective lens for converging light from the light source onto an optical disk mounted on the rotation driving section; a photodetector having at least two detection sections for detecting reflected light, from the optical disk, of the light; and an error signal generation section for deriving a difference signal and a sum signal of respective outputs from the two detection sections of the photodetector, adjusting an offset in at least the sum signal among the difference signal and the sum signal, and thereafter dividing the difference signal by the sum signal whose offset has been adjusted to generate a position error signal of the objective lens.

Abstract: A thermal bonding conjugate fiber constituted from a first component comprising a polyester resin and a second component comprising a polyolefin resin with a melting point lower than that of the polyester resin by not less than 20° C., characterized in that a post-heat treatment bulk retention rate thereof is 20% or more when calculated by the following measurement method: Bulk retention rate=(H1 (mm)2/H0 (mm))×100 (%) (wherein H0 is the web height when a 0.1 g/cm2 load is applied to a web with a mass per unit area of 200 g/m2; and H1 is the web height after a heat treatment for 5 min at 145° C. when a 0.1 g/cm2 load is applied to that web).

Abstract: An optical disk apparatus including: a light source; an objective lens for converging light emitted from the light source toward an optical disk; a first photodetection device for detecting reflected light from the optical disk and outputting a first signal; a signal processing section for receiving the first signal and generating a signal containing information recorded on the optical disk; a second photodetection device for detecting a portion of the light emitted from the light source and outputting a second signal; a light source driving section for receiving the second signal, and based on the second signal, driving the light source so that output power of the light source equals a target value; and an amplitude fluctuation detection section for detecting an amplitude fluctuation amount of the second signal, and if the amplitude fluctuation amount exceeds a predetermined value, changing driving characteristics of the light source driving section.

Abstract: An optical pickup device according to the present invention includes: first and second light sources that are driven selectively and that emit blue and red light beams, respectively; an optical element for splitting the blue and red light beams emitted into main and sub-blue beams and main and sub-red beams, respectively; first and second photodetectors that receive the main and sub-blue beams reflected from the optical disc, thereby outputting electrical signals; and third and fourth photodetectors that receive the main and sub-red beams reflected from the optical disc, thereby outputting electrical signals. A dead zone that outputs no electrical signal representing the intensity of the light received is provided for respective parts of the second and fourth photodetectors.

Abstract: An optical disk apparatus according to the present invention includes: a rotation driving section on which an optical disk is to be mounted and which drives the optical disk so as to be rotated; a light source; an objective lens for converging light from the light source onto an optical disk mounted on the rotation driving section; a photodetector having at least two detection sections for detecting reflected light, from the optical disk, of the light; and an error signal generation section for deriving a difference signal and a sum signal of respective outputs from the two detection sections of the photodetector, adjusting an offset in at least the sum signal among the difference signal and the sum signal, and thereafter dividing the difference signal by the sum signal whose offset has been adjusted to generate a position error signal of the objective lens.

Abstract: Light emitted from alight source (5) is reflected by the reflection film of a polarized beam-splitter (6), passes through collimating lens (7) and a mirror (8) to reach a convergence lens (9). The convergence lens (9) forms a light spot on an information medium (1) having a visual information layer (4). Reflected light which is reflected by the visual information layer (4) passes through the convergence lens (9), the mirror (8), and the collimating lens (7), transmits through the reflection film of the polarized beam-splitter (6), passes through a half mirror (14) to reach a second light detector (13). The second light detector (13) detects an FE signal for the visual information layer (4) and feeds back the detected signal to an LPC circuit, thereby restricting power fluctuation due to surface deflection.