Ricoh Company, Ltd.

Other

Agency of Industrial Science and Technology

Toshihiko Baba

Hiroyoshi Funato

Shigeyoshi Misawa

Shigeaki Imai

Shigeru Ohuchida

Takashi Shibaguchi

Hiroshi Kobayashi

Tadashi Nakamura

Koji Masuda

Shuichi Suzuki

Mitsuru Nakajima

Hiroaki Fukuda

Kenichi Yoshimura

Magane Aoki

Haruhiko Machida

Tami Isobe

Kiyoshi Yokomori

Shigeru Oohchida

Yoshinobu Nakayama

Jun Akedo

Syunsuke Fujita

Yoshinori Hayashi

Kazuhiro Fujita

Yutaka Kaneko

Atsushi Sakai

Nobuo Kasahara

Masanori Kobayashi

Koichi Kudo

Hiroshi Koide

Kazunori Bannai

Makoto Hirakawa

Yasuhiro Nihei

Nobuo Sakuma

Yutaka Hayashi

Michiharu Abe

Atsushi Takaura

Takeshi Ueda

Hiroyuki Sugimoto

Kazuya Miyagaki

Hidemasa Suzuki

Junichi Kitabayashi

Daisuke Imaki

Ikuo Katoh

Yoshio Fukushima

Iwao Hamaguchi

Tsuyoshi Suzudo

Shunsuke Fujita

Motoaki Kawazu

Tomoyuki Yamaguchi

Nobuo Banba

Yoshimura Kenikenichi

A moving-member detecting device includes an image acquiring unit and a speed calculating unit. The image acquiring unit includes a light source configured to emit a light beam to a detecting position of a moving member; an area sensor configured to acquire image data of a one- or two-dimensional image; and an area-sensor control unit configured to acquire the image data. The image acquiring unit is configured to acquire pieces of image data of the moving member at first and second positions, respectively, in a moving direction of the moving member so as to acquire the piece of position image data for the second position when the moving member is at the second position after acquiring the piece of image data for the first position. The speed calculating unit is configured to calculate a moving speed of the moving member from the pieces of image data.

Moving-member detecting device and image forming apparatus

An object detection apparatus includes an incident optical system, which includes light source units and a combining unit combining light beams emitted from the light source units; a deflection unit including rotating reflection parts that deflect the light beams to scan and be irradiated on a predetermined range of an object; an imaging unit forming an image based on the light from the predetermined range of the object; and an optical detection unit detecting the object based on the light received via the imaging unit. Further the combining unit combines the light beams such that each of the combined light beams passes a single light path when projected onto a predetermined plane, and each of the light paths exists outside a region of the deflection unit when projected onto the first plane.

Object detection apparatus with detection based on reflected light or scattered light via an imaging unit

Disclosed is a laser radar device including a modulated light beam generator that emits light beams to a target, a photodetector that receives reflected light; a reflected light condenser that condenses the reflected light; a rotator that rotates around a rotation axis; and mirrors included in the rotator that scan the light beams, and guide the reflected light to the reflected light condenser, wherein an angular detection range in a vertical direction is divided into a plurality of layers, wherein mirror surfaces of the mirrors are tilted by corresponding tilt angles relative to the rotation axis, the tilt angles being different from each other, wherein the modulated light beam generator emits the light beams in the vertical direction, the light beams having different emission angles, and wherein a difference between the emission angles corresponds to the angular detection range of one layer in the vertical direction.

Laser radar device

A velocity detecting device includes an image-pattern acquiring unit that includes a laser light source and an area sensor that acquires a one-dimensional or a two-dimensional image. The image-pattern acquiring unit includes a lens between a moving member and the area sensor, irradiates a beam emitted from the laser light source to the moving member to make a scattering light of the moving member scattered from the moving member on the area sensor by using the lens, and acquires an image pattern at a predetermined time interval in association with movement of the moving member. A velocity calculating unit calculates the velocity of the moving member by computing the image pattern acquired by the image-pattern acquiring unit. The lens is a reduced optical system that projects a reduced object onto the area sensor.

Velocity detecting device and multi-color image forming apparatus

P-polarized light beam passing through an f&#x3b8; lens passes through a polarization beam splitter, is converted into S-polarized light beam by a quarter-wave plate and a reflecting mirror, re-enters the polarization beam splitter, and is reflected at the polarization beam splitter in the &#x2212;Z direction. An optical path of a light beam between a polygon mirror and the f&#x3b8; lens, between the f&#x3b8; lens and the polarization beam splitter, between the polarization beam splitter and the quarter-wave plate, between the quarter-wave plate and a reflecting mirror, between the reflecting mirror and the quarter-wave plate, and between the quarter-wave plate and the polarization beam splitter are in the same plane.

Optical scanning device and image forming apparatus

An optical scanning device including a light source, a deflection device to deflect a light beam from the light source, an image focus optical system to focus the light beam deflected by the deflection device on a scanned surface to form an image thereon and scan a surface by the light beam deflected by deflection device to form an image thereon, a light path switching device provided between the light source and the deflection device, which switches a light path of the light beam emitted from the light source to deflect the light beam on different timings such that the light beam scans different surfaces.

Optical scanning device

An optical delay element including a photonic crystal line defect optical waveguide is disclosed that has a large group refractive index and has small or nearly constant wavelength dispersion of the group refractive index in a wide wavelength region for practical use. The optical delay element includes a line defect optical waveguide formed in a photonic crystal structure, and the volume of the line defect optical waveguide is less than the volume of a single line defect optical waveguide. Thereby, the waveguide band of the line defect optical waveguide has two zero points in the third order dispersion curve of the line defect optical waveguide, and the sign of the third order dispersion curve is inverted near the zero points. Therefore, the waveguide band of the line defect optical waveguide is modified, and this enables expansion of the wavelength region having a large group refractive index, small wavelength dispersion of the group refractive index, and small wavelength dispersion of the speed of optical pulses.

Optical delay element

An optical pickup apparatus used in an optical data recording/reproducing apparatus for reading/reproducing data on an optical recording medium, including a light source, a diffracting device configured to transmit a light beam and to diffract a light beam reflected from the optical recording medium, an optical device having a reflecting portion and a transmitting portion configured to reflect one part of the light beam emitted from the light source and to transmit another part of the light beam to the optical recording medium and from the optical recording medium, and a photodetecting device to detect the light beam from the optical recording medium for signal light detection, and the light beam reflected by the reflecting portion of the optical device for monitor light detection of the light source.

Optical pickup apparatus, optical data recording/reproducing apparatus, and optical data recording/reproducing method

A polarization diffraction grating includes two media having different orientation states arranged alternately and cyclically, wherein each boundary between the media forms an oblique rectangular shape.

Diffraction grating, light source unit applying the same therein, and optical head device employing the same

Optical apparatus for recording/reproducing and reading/reproducing data on an optical recording medium, and method for using same

An optical pickup unit includes a light source of semiconductor laser chips of different light-emission wavelengths; a plurality of holograms placed between the light source and an optical recording medium, the holograms including at least one non-polarization hologram having a substantially uniform diffraction efficiency irrespective of the direction of polarization of incident light and at least one polarization hologram having a diffraction efficiency varying depending on the direction of polarization of incident light; and a wave plate provided between the optical recording medium and the polarization hologram. The returning beam of a light beam emitted from a selected one of the semiconductor laser chips is diffracted by the corresponding one of said holograms to be received by a light-receiving element. The wave plate turns the direction of polarization of the returning beam to a different direction from that of the emitted light beam.

Optical pickup unit and optical disk drive for accurate and stable information recording and reproduction

In an optical pickup method and device of the present invention, a grating unit separates a light beam, emitted by a light source, into a 0th order diffracted beam and 1st order diffracted beams. An objective lens focuses the diffracted beams, sent from the grating unit, onto a recording surface of an optical recording medium through a transparent substrate of the medium, so that a main spot is formed on the recording surface by the 0th order diffracted beam and sub-spots, interposing the main spot therebetween, are formed on the recording surface by the 1st order diffracted beams. A reflection beam detector receives reflection beams from the main spot and the sub-spots of the medium to generate detection signals from the received reflection beams. A control unit changes a pattern of the beams incident to the objective lens to correct a spherical aberration due to a deviation of a thickness of the substrate of the medium, and moves the grating unit relative to the light source to cancel shifting of sub-spot positions on the recording surface due to the spherical aberration correction, in order to generate a proper tracking error signal.

Optical pickup method, optical pickup device, and optical information processing apparatus adapted with spherical aberration correction for sub-spot tracking control

An optical pickup apparatus includes first and second light sources which selectively emit one of first and second light beams, the first and second light beams being different in wavelength, the wavelengths of the first and second light beams being appropriate for accessing first and second optical disks respectively. A coupling lens converts a corresponding one of the first and second light beams into a collimated beam. An objective lens forms a light spot on a corresponding one of the first and second optical disks by focusing the collimated beam. A holographic optical element receives a reflection beam of the light spot from one of the first and second optical disks and provides holographic effects on the reflection beam so as to diffract the reflection beam in predetermined diffracting directions depending on the wavelength of the reflection beam. A photodetector receives the reflection beam from the holographic optical element at light receiving areas and outputs signals indicative of respective intensities of the received reflection beam at the light receiving areas, so that a focusing error signal and a tracking error signal are generated based on the signals.

Optical pickup apparatus having improved holographic optical element and photodetector

Optical pickup apparatus having improved holographic optical element and

An optical head which records data onto an optical data recording medium and reproduces the data therefrom includes a laser light source, a collimator lens, an objective lens, a light splitting device arranged between the laser light source and the objective lens, for splitting the emitted light from the laser light and a reflected light from the optical data recording medium. A diffraction grating is provided to which only the reflected light split at the light splitting device is incident to, and which leads the reflected light split at the optical element onto a photo-detector. Thereby, an optical head of high effectiveness in utilization of light and low cost can be obtained.

Optical head with forward and reflected light beams propagating through

Growing community of inventors

Chigasaki, Japan

Hiroyoshi Funato