Abstract: An optical pickup device includes: a splitting section for splitting a beam; a light-receiving section for receiving the split beams. The light-receiving section includes: a tracking-use main light-receiving region and tracking-use sub light-receiving regions, and auxiliary light-receiving regions. Each of the auxiliary light-receiving regions receives only a light beam reflected off a recording layer other than a recording layer subjected to an information writing/reading process. A light-receiving area of each of the auxiliary light-receiving area is smaller than a light-receiving area of each tracking-use light-receiving region. Further, an optical pickup device includes: a splitting section for splitting a beam; and a light-receiving section for receiving the split beams. The light-receiving section includes a sub light-receiving regions for receiving tracking-use sub beams.

Abstract: In order to accurately measure a shape feature of a minute droplet arranged on a substrate by a simple method, with respect to the droplet, the substrate is perpendicularly irradiated with laser light to cause diffracted light fluxes generated during passage of the laser light through the droplet to interfere with each other, so that a diffraction pattern is obtained. The diffraction pattern formed on a screen of a detector as an image is picked up by an image pickup apparatus. The shape feature of the droplet is measured by using the resultant diffraction pattern and a refractive index of the droplet.

Abstract: An optical integrated unit includes a light-emitting portion for emitting a plurality of laser beams having different wavelengths, a wave plate, a polarization hologram element for diffracting a first laser beam emitted from a light source, and a non-polarization hologram element for diffracting a second laser beam emitted from a light source. Wave plate is formed to act as a ?/4 plate for the first laser beam and act as a ? plate or a ?/2 plate for the second laser beam.

Abstract: An object of the present invention is to attain stable tracking servo performance by suppressing an offset caused by a shift of an object lens or a tilt of a disk, despite the one-beam method which does not cause reduction in light quantity of the main beam. A diffraction grating is provided between a hologram and a light receiving section, and a diffraction efficiency of the diffraction grating is varied in a grating longitudinal direction. For example, if an incident light beam on the diffraction grating is shifted in the grating longitudinal direction, the quantity of received light in each light receiving section varies to cause offset. By performing tracking servo so as to cancel the change, it is possible to correct the offset, thereby attaining stable tracking servo performance.

Abstract: In a light-emitting section (2) for emitting semiconductor laser for CD (4) and semiconductor laser for DVD (5), a radiation angle width ?2 of the DVD semiconductor laser (5) is at least 1.3 times a radiation angle width ?1 of the CD semiconductor laser (4), said radiation angle width being defined as a width of an angle created by two straight lines, which extend respectively from a laser-emitting point to two points where a radiation intensity of laser becomes half of an intensity of the center of laser, which points reside within a plane parallel to a pn junction plane.

Abstract: A defect inspection apparatus includes an illumination optical unit for obliquely illuminating an object with a slit-like shaped laser, a first detection optical unit for detecting a first image formed by light reflected from the object by the illumination of the slit-like shaped laser and reflected in a first direction substantially normal to a surface of the object, a second detection optical unit for detecting a second image formed by light reflected from the object by the illumination of the slit-like shaped laser and reflected in a second direction inclined to the normal direction to the surface of the object, an image signal processing unit which processes a signal outputted from the first detection optical unit and a signal outputted from the second detection optical unit, and an output unit which outputs information processed by the image signal processing unit.

Abstract: A method for detecting defects on a specimen includes mounting a specimen on a table with which is movable, obliquely projecting a laser as a line onto a surface of the specimen, detecting with an image sensor an image of light formed by light reflected from the specimen and passed through a filter which blocks scattered light resulting from repetitive patterns formed on the specimen, processing a signal outputted from the image sensor to extract defects of the specimen, and a displaying information of defects extracted by the signal processor.

Abstract: An optical pickup converts a laser beam from a semiconductor laser (1) into a parallel ray with a collimator lens (2), and divides it into a main beam (30), a sub-beam (+1st order component) (31), and a sub-beam (?1st order component) (32) with a gradient multiple-division type phase difference grating (3). After passing through a beam splitter (4), an objective lens (5) condenses the light beams on a track (61) of an optical disc (6), and the reflected light that has passed through the objective lens 5 is reflected at the beam splitter (4) and is guided into optical detectors (8A, 8B, and 8C) by a condensing lens (7). Accordingly, in a tracking error signal detecting method using the push-pull signals of the main beam and sub-beams, an offset produced by an objective lens shift or a disc tilt can be cancelled at low cost without lowering the efficiency of using light.

Abstract: An object of the invention is to provide a splitter, a light emitter, and an optical pickup apparatus which can realize a stable track servo. Because of the structure of an optical system including an objective lens (27) and a hologram pattern (25), even when the hologram pattern (25) is irradiated with a reflected light from one recording layer other than another recording layer in a focused state, first and second TES splitting portions (35, 36) are not irradiated with the reflected light from the one recording layer, but the reflected light is led to an axis vicinity portion (38) only. Accordingly, light reception by first and second TES light receiving portions (45, 46) is prevented, accurate track position information and deviation information can be positively acquired, and troubles such as the objective lens (27) being driven beyond a movable range can be eliminated.

Abstract: In this semiconductor laser device, a polarization hologram transmits an outgoing beam directed from a semiconductor laser chip to an optical disk as a forward beam without diffracting the beam, and diffracts a backward beam of the laser beam, which is a return beam of the forward beam that has been reflected by the optical disk, so that the backward beam is deflected from a direction directed toward the semiconductor laser chip part and further directed toward first, second photoreception parts. Therefore, optical loss on the forward way from the semiconductor laser chip to the optical disk can be reduced, and return light to the semiconductor laser chip can be suppressed, so that a high-power, high-sensitivity semiconductor laser device can be realized.

Abstract: An optical pickup can be provided, the optical pickup being capable of recording and playback of a plurality of optical disks having different specs by using light beams of different wavelengths, and further being suitable for integrating the semiconductor lasers and light receiving elements into a single package, by including: first and second semiconductor lasers adjacently disposed; a three-beam diffraction grating for generating three beams for tracking control; a second hologram element for diffracting light of the second semiconductor laser to guide it to a photosensor; a complex polarization beam splitter (PBS) for reflecting only light from the first semiconductor laser; and a first hologram element for diffracting light of the first semiconductor laser to guide it to the photosensor.

Abstract: A defect inspection method includes radiating an illumination slit-shaped beam having lights substantially parallel to a longitudinal direction to a substrate having circuit patterns in a direction inclined at a predetermined gradient relative to the direction of a line normal to the substrate and inclined at a predetermined gradient on a surface with respect to a group of main straight lines of the circuit patterns with its longitudinal direction oriented almost perpendicularly to a direction of a movement of the substrate. Scattered light reflected by a defect such as a foreign particle existing on the illuminated substrate is received and converted into a detection signal by using an image sensor, and defect judging is effected of an extracted a signal indicating a defect such as a foreign particle on the basis of the detection signal output.

Abstract: A defect inspection method includes radiating an illumination slit-shaped beam having lights substantially parallel to a longitudinal direction to a substrate having circuit patterns in a direction inclined at a predetermined gradient relative to the direction of a line normal to the substrate and inclined at a predetermined gradient on a surface with respect to a group of main straight lines of the circuit patterns with its longitudinal direction oriented almost perpendicularly to a direction of a movement of the substrate. Scattered light reflected by a defect such as a foreign particle existing on the illuminated substrate is received and converted into a detection signal by using an image sensor, and defect judging is effected of an extracted a signal indicating a defect such as a foreign particle on the basis of the detection signal output.

Abstract: The object of the invention is to accurately detect the amount of tilt in the light reflector to the optical axis of an output light with a simple configuration. A tilt sensing apparatus includes a light reflector, a light source, a condensing unit for condensing an output light from the light source onto the light reflector, and a light sensing unit for sensing the reflected light from the light reflector. An optical device provided in the condensing unit for varying the light quantity of the transmitting light has first and second optical device strips that are formed at the positions of axial symmetry about the optical axis and have a predetermined shift in the direction of a straight line of connecting the axis of the light reflector to the condensed position where the light emitted from the light source is condensed onto the light reflector by the condensing unit.

Abstract: An apparatus for detecting defects on a specimen including am illumination optical unit which obliquely projects a laser onto a region which is longer in one direction than in a direction transverse to said one direction on a surface of a specimen, a table unit which mounts said specimen and which is movable, a detection optical unit which detects with an image sensor an image of light formed by light reflected from said specimen in both directions of the one direction and the direction transverse and which reflected light in both directions is formed on said image sensor while said table is moving, a signal processor which processes a signal outputted from said image sensor of said detection optical unit to extract defects of said specimen. A display unit which displays information of defects extracted by said signal processor.

Abstract: A defect inspection method includes radiating an illumination slit-shaped beam having lights substantially parallel to a longitudinal direction to a substrate having circuit patterns in a direction inclined at a predetermined gradient relative to the direction of a line normal to the substrate and inclined at a predetermined gradient on a surface with respect to a group of main straight lines of the circuit patterns with its longitudinal direction oriented almost perpendicularly to a direction of a movement of the substrate. Scattered light reflected by a defect such as a foreign particle existing on the illuminated substrate is received and converted into a detection signal by using an image sensor, and defect judging is effected of an extracted a signal indicating a defect such as a foreign particle on the basis of the detection signal output.

Abstract: A focus error detecting device which can realize stable focus servo without causing a deterioration in the quality of a signal, is provided. The focus error detecting device outputs a reflected light detection result by an optical recording medium to control a distance between an objective lens and the optical recording medium. With respect to the focus error detecting device, between the objective lens and two split light-receiving segments, is provided a hologram element for bending an optical path so that part of light reflected by the optical recording medium enters the two split light-receiving segments, and splitting a light beam of reflected light entering the two split light-receiving segments into a plurality of parts.

Abstract: An optical pickup converts a laser beam from a semiconductor laser (1) into a parallel ray with a collimator lens (2), and divides it into a main beam (30), a sub-beam (+1st order component) (31), and a sub-beam (?1st order component) (32) with a gradient multiple-division type phase difference grating (3). After passing through a beam splitter (4), an objective lens (5) condenses the light beams on a track (61) of an optical disc (6), and the reflected light that has passed through the objective lens 5 is reflected at the beam splitter (4) and is guided into optical detectors (8A, 8B, and 8C) by a condensing lens (7). Accordingly, in a tracking error signal detecting method using the push-pull signals of the main beam and sub-beams, an offset produced by an objective lens shift or a disc tilt can be cancelled at low cost without lowering the efficiency of using light.

Abstract: An optical pickup can be provided, the optical pickup being capable of recording and playback of a plurality of optical disks having different specs by using light beams of different wavelengths, and further being suitable for integrating the semiconductor lasers and light receiving elements into a single package, by including: first and second semiconductor lasers adjacently disposed; a three-beam diffraction grating for generating three beams for tracking control; a second hologram element for diffracting light of the second semiconductor laser to guide it to a photosensor; a complex polarization beam splitter (PBS) for reflecting only light from the first semiconductor laser; and a first hologram element for diffracting light of the first semiconductor laser to guide it to the photosensor.

Abstract: To read information from a target information recording surface reliably by canceling DC offsets in tracking-signal detection signals is provided. In effecting tracking servo by 3-beam method, auxiliary light receiving domains D3—1, D3—2, D8—1, D8—2 are provided. The auxiliary light receiving domain receives images formed by the light returned from a different information recording surface from the one targeted for reading. Sub beams of ± first-order diffracted light enter the light receiving domains D3, D8, D1, D10. With respect to the diffraction direction of the hologram, the auxiliary light receiving domains D3—1, D3—2 (D8?1, D8—2) are provided on both sides of the light receiving domain D3 (D8). Since signals are computed as: D8-(D8—1+D8—2); and D3-(D3—1+D3—2) with the internal connection, DC offsets can be canceled in RES signals (D1+D3, D8+D10) used in the DPP method.