Sharp Kabushiki Kaisha Corporation

Renzaburo Miki

Yukio Kurata

Keiji Sakai

Tetsuo Ueyama

Noboru Fujita

Yoshio Yoshida

Kuniaki Okada

Hiroyuki Yamamoto

Katsushige Masui

Hiroshige Hirajima

Kouji Minami

Naotaka Otsuka

Takahiro Miyake

Osamu Miyazaki

Fumio Kokubo

Hiroshige Makioka

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

Power from a focusing motor () is transmitted via a gear () to a focusing lead screw () so that a first lens holder () is moved in a direction of an optical axis. Power from a zooming motor () is transmitted via a gear () to a zooming lead screw () so that a second lens holder () is moved in the direction of the optical axis. The first and second lens holders (), the focusing and zooming lead screws (), the focusing and zooming motors (), and the gears () are contained in a housing (). The focusing motor () and the zooming motor () may be fixed to a gear case ().

Lens actuating device, camera module and portable electronic equipment

An opening direction of guide grooves formed in sub bearing portionsare different from an opening direction of guide grooves formed in the main bearing portions. Therefore, when the first, second lens holderscan easily be assembled to the main guide shaftand the sub guide shaftby one operation that after the fitting of the sub guide shaftinto the guide groove of the sub bearing portionin the first, second lens holder, the first, second lens holderis rotated and slid against the sub guide shaftso that the guide groove of the main bearing portionis fitted to the main guide shaftin Y direction.

Lens barrel assembly and assembling method therefor

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.

Optical pickup

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

An optical device includes: a first dielectric slab waveguide having an effective refractive index N.sub.1 ; a second dielectric slab waveguide having an effective refractive index N.sub.2 ; and a third dielectric slab waveguide having a length 1 and an effective refractive index N.sub.3, the third dielectric slab waveguide being formed between the first dielectric slab waveguide and the second dielectric slab waveguide so as to connect the first dielectric slab waveguide with the second dielectric slab waveguides optically; wherein the length I and the effective refractive index N.sub.3 substantially satisfy following equations; ##EQU1## where .lambda. is a free-space wavelength of light traveling in the optical device and the light travels from the first dielectric slab waveguide to the third dielectric slab waveguide at an incident angle .THETA. in a single mode.

Optical device having two optical waveguides connected and a method of

An optical integrated circuit is disclosed. The optical integrated circuit includes: a dielectric waveguide having at least a waveguide layer for transmitting light in a first direction; a first reflector for reflecting the light in a substantially opposite direction to the first direction, the first reflector being formed on an end face of the waveguide layer; a grating coupler having a grating for diffracting at least a part of the light in a second direction which is different from the first direction, the grating coupler being formed at a surface of the waveguide layer; and a light detector for detecting the diffracted light, the light detector being optically connected with the dielectric waveguide.

Growing community of inventors

Kyoto, Japan

Renzaburo Miki