Sharp Kabushiki Kaisha Corporation

Sharp Kabushiki Saisha

Keiji Sakai

Yukio Kurata

Tetsuo Ueyama

Yoshio Yoshida

Hiroyuki Yamamoto

Katsushige Masui

Takahiro Miyake

Renzaburo Miki

Kuniaki Okada

Osamu Miyazaki

Kazuhiro Tsuchida

Noboru Fujita

Naotaka Otsuka

Toshiyuki Tanaka

Yasuo Nakata

Yukio Watanabe

Kohji Minami

Masahiro Ikehara

Toshiya Nagahama

Katsuhiro Kubo

Masayasu Futagawa

Hiroshige Hirajima

Eiji Kurimoto

Kenji Nakanishi

Shohichi Fukutome

Yasuhiro Suto

Mitsuharu Yoshimoto

Hisashi Yamanaka

Hirotsugu Matoba

Tomohiko Okada

Hideyoshi Yamaoka

Kazunori Matsubara

Toshio Ishikawa

Yoshihisa Yamada

Takeshi Takayama

Sumito Nishioka

Fumio Kokubo

Renzaburou Miki

Kouji Minami

Kazuya Ikuta

Takuya Ishizaka

Hiroshige Makioka

A light source module of the present invention is configured such that there is a through hole () in one longitudinal end portion of a light guide () that constitutes a light guide plate, into which through hole () a positioning pin () for positioning an LED light source () and the light guide () fits. Further, a guide () is provided to the other end portion of the light guide (), which guide () restrains the light guide () in a direction of a short side but does not restrain the light guide () in a direction of a long side. This makes it possible to provide a light source module that can reduce warping and cracking caused by expansion of a light guide, and an electronic apparatus including the light source module.

Light source module and electronic apparatus provided with same

In a light source unit () serving as an embodiment of an illuminating apparatus, when P is a light-emitting element pitch [mm], and H is an optical axis distance [mm] between light-emitting elements () and an original (G), and when, in an illuminance cycle (T) representing repetition of bright and dark areas in a main scanning direction (X) on a light-irradiated face (Gs) of the original (G) caused by the light-emitting elements (), the light-emitting element pitch (P) and the optical axis distance (H) are set such that unevenness [%] (M) (=(LL)/L%]) obtained by dividing a value obtained by subtracting a minimum illuminance value (L) from a maximum illuminance value (L) by an average illuminance value (L) and an inter-unevenness distance [mm] (N) which is a half cycle of the illuminance cycle (T) satisfy the relation M&#x2266;N/2&#x2212;5.5, and more preferably, M&#x2266;N/2&#x2212;7.5.

Illuminating apparatus, image reading apparatus, and image forming apparatus

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. The tracking-use sub beams are arranged so as not to allow entering of a focusing-use main beam reflected off a non-targeted recording layer.

Optical pickup unit and optical pickup device having same and information writing/reading device having same

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 () and a hologram pattern (), even when the hologram pattern () 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 () are not irradiated with the reflected light from the one recording layer, but the reflected light is led to an axis vicinity portion () only. Accordingly, light reception by first and second TES light receiving portions () is prevented, accurate track position information and deviation information can be positively acquired, and troubles such as the objective lens () being driven beyond a movable range can be eliminated.

Splitting element, light emitter, and optical pickup apparatus

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 D, D, D, Dare 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 &#xb1; first-order diffracted light enter the light receiving domains D, D, D, D. With respect to the diffraction direction of the hologram, the auxiliary light receiving domains D, D(D, D) are provided on both sides of the light receiving domain D(D). Since signals are computed as: D&#x2212;(D+D); and D&#x2212;(D+D) with the internal connection, DC offsets can be canceled in RES signals (D+D, D+D) used in the DPP method.

Optical pickup device using polarizing hologram element and hologram laser therefor

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.

Light integration unit, optical pickup device using the unit, and optical disk device

An optical pickup converts a laser beam from a semiconductor laser () into a parallel ray with a collimator lens (), and divides it into a main beam (), a sub-beam (+1st order component) (), and a sub-beam (&#x2212;1st order component) () with a gradient multiple-division type phase difference grating (). After passing through a beam splitter (), an objective lens () condenses the light beams on a track () of an optical disc (), and the reflected light that has passed through the objective lensis reflected at the beam splitter () and is guided into optical detectors (A,B, andC) by a condensing lens (). 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.

Optical pickup

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.

Semiconductor laser device and optical pickup device

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.

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.

Apparatus for detecting the tilt of a light reflector relative to the optical axis of input light

A hologram laser unit to be used for performing recording and reproducing operations of information for an optical disk, includes a light source, a photodetector, and a hologram element which are formed integrally with each other. The hologram element includes: a first hologram for detecting information signals from the optical disk, the first hologram being provided in an area having an effective diameter corresponding to a numerical aperture suitable for the optical disk; and a second hologram for compensating for only a transmitted light amount of light traveling toward the optical disk from the light source, the second hologram being provided contiguously outside the first hologram.

Hologram laser unit and optical pickup device including the same

A light receiving element ( ) receiving return light from an optical disk has main light receiving sections ( ) and sub light receiving sections ( ). A focus error signal is found by computing (Sa&plus;Sf )&minus;(Sb&plus;Se), where Sa, Sb, Se, and Sf represent output signals of the light receiving sections ( ), respectively. Each of the sub light receiving sections ( ) has a smaller area than each of the main light receiving sections ( ) has. With the foregoing arrangement, upon access to a multilaminate optical disk in which distances between recording layers are small, respective focus error signals from the recording layers do not interfere with each other, and occurrence of an offset can be suppressed even in the case where an assembly error of the optical element or the like exists.

Optical pickup device

An objective lens driving apparatus includes a base, an objective lens for converging an optical beam on an optical disc while the optical disc is rotating, and a holding member for holding the objective lens. A first supporting mechanism elastically supports the holding member on the base in such a manner as to allow the holding member to be translated in a focusing direction which is substantially perpendicular to a surface of the optical disc and in a tracking direction which is substantially perpendicular to the focusing direction and parallel to a radial direction of the optical disc. A moving mechanism including a coil and a magnetic circuit for translates the holding member in the focusing direction and the tracking direction by a driving force generated by the coil and the magnetic circuit. A second supporting mechanism for visco-elastically supports the magnetic circuit on the base in such a manner as to translate the magnetic circuit in the focusing direction. The magnetic circuit is translated in an opposite direction to the translation direction of the holding member by a driving force acting oppositely to the driving force for translating the holding member in the focusing direction.

Objective lens driving apparatus and method including visco-elastic

A mode splitter and the magneto-optical pick-up device including the mode splitter. The mode splitter includes a tapered waveguide portion whose thickness gradually becomes thin so that a light of at least one mode can be cut off. An emission position of a light wave can be varied depending on its mode. In this mode splitter, the emission position of the light wave of each mode can be adjusted by changing a thickness of the tapered waveguide, thereby improving the degree of freedom in designing the device.

Magneto-optical disk pick-up device having mode splitter using cut off

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Nara, Japan

Keiji Sakai