Ricoh Company, Ltd.

Hitachi, Ltd.

Katsumi Yamaguchi

Nobuo Sakuma

Tomohiro Nakajima

Norio Michiie

Susumu Imakawa

Makoto Hino

Seizo Suzuki

Kazuyuki Shimada

Nobuyuki Kaku

Shuichi Yamazaki

Tatsuya Ito

Yasuhiko Suzuki

Osamu Endo

Akira Shimura

Masaki Narita

Seizoh Suzuki

Satoru Ito

To provide an image display apparatus that is allowed to incorporate a panel module with excellent mechanical strength even if a screen is upsized and the apparatus is slimmed down. Strengthening units are mounted along a horizontal direction on canopies provided on an upper portion and a lower portion of a panel module constituting a display unit of a large-size, thin image display apparatus. Also, supporting members are mounted on the upper and lower strengthening units in such a manner that the supporting members bridge between the upper and lower strengthening units, so that a stand, or a chain or a string to be used when hanging the image display apparatus is mountable to the supporting members. This prevents direct application of external force to the panel module.

Display apparatus for displaying an image

A multiple beam scanning apparatus and a light source unit employed in the multiple beam scanning apparatus and a method of multiple beam scanning. A multiple beam scanning apparatus is realized which utilizes a multiple beam system in which four or more light beams are employed with comparatively low cost without making a light source unit, deflection medium, focusing optical system, etc. large sized. The light source unit employed in the multiple beam scanning apparatus includes m (m.gtoreq.2) pieces of semiconductor laser arrays respectively having n (n.gtoreq.2) light-emitting points. A multiple beam system is realized utilizing n-times multiple beams without making the light source unit large sized. Furthermore, another multiple beam system is realized utilizing m-times multiple beams and enabling making such a multiple beam system on further profitable conditions.

Multiple beam scanning apparatus and light source unit therefor

The current disclosure discloses methods of and systems for automatically adjusting or selecting a pitch between beams in a multi-beam scanning system. An array of light sources is mounted on a rotatable housing and emits light in a direction perpendicular to the rotational plane. The system or method measures a pitch on or near an intermediate image-forming surface. In response to the measured pitch, the scanning as well as sub-scanning pitch is automatically adjusted or selected by rotating a housing unit to maintain a desired pitch.

Multi-beam pitch adjustment system and method

A multi-beam light source device which can be used in an optical scanning device has less optical cross-talk and an improved stability in frequency response. The multi-beam light source device comprises a semiconductor laser array having a plurality of light emitting sources, a light receiving element array having a plurality of light receiving elements and a half mirror splitting a light beam emitted by the semiconductor laser array into at least two split light beams. A light converging unit is provided for converging one of the split light beams at a predetermined focal point. The light receiving element array is positioned at the focal point of the light converging unit for receiving the concentrated one of the split light beams. A controlling circuit is provided for controlling an output of the semiconductor laser array in accordance with the amount of light received by the light receiving element array. Optical cross-talk generated between the split light beams emitted by adjacent ones of the light emitting sources is suppressed by an optical cross-talk suppressing unit.

Multi-beam light source device and optical scanning apparatus using the

An optical recording apparatus comprises a laser diode array including a plurality of laser diodes for producing a plurality of laser beams in response to a drive signal indicative of an image, an optical system for scanning the laser beams on a surface of a photosensitive body, a beam splitting unit for splitting the laser beams produced by the laser diodes to form control laser beams; a driver for driving each of the laser diodes in the laser diode array, an optical detection unit provided for detecting the control laser beams, the optical detection unit including a plurality of photodetectors in correspondence to the laser diodes in the laser diode array in a one-to-one relationship, each of the photodetectors producing an output signal indicative of an optical power of the control laser beam incident thereto, and a control unit supplied with the output signals from the photodetectors in the optical detection unit for controlling the driver such that each of the laser diodes in the laser diode array produces the laser beam with a controlled optical power.

Optical recording apparatus capable of controlling optical power of

A scanning optical system has a light source for emitting a light beam; a condenser lens for changing the light beam from the light source to a parallel light beam; a connection holding member for supporting the light source and the condenser lens; a deflector for deflecting an approximately parallel light beam transmitted from the condenser lens at an equiangular velocity; and a lens for optical scanning for scanning a scanned face at an approximately equal speed while converging the light beam deflected by the deflector and forming an image in the shape of a spot on the scanned face, the lens for optical scanning being formed by a plastic material for optics. This scanning optical system is constructed such that a coefficient of linear expansion of the connection holding member, a focal length of the condenser lens, a focal length, a refractive index and a coefficient of linear expansion of the lens for optical scanning, and a change in refractive index of the lens for optical scanning with respect to the change in environmental temperature satisfy a predetermined condition. Another condition using other parameters with respect to the lens optical system may be set.

Scanning optical system

An optical scanning system includes a light source, a coupling lens, a polygon mirror, an f.theta. lens, and a barrel toroidal lens. The barrel toroidal lens includes a barrel toroidal surface in which the radius of curvature thereof measured in the sub-scanning direction decreases with an increased distance from the optical axis of the barrel toroidal lens in a direction parallel to the main scanning direction.

Optical scanning system

A scanning optical system for use in a light scanner including a light deflector for deflecting a light beam to scan a surface is disposed between the light deflector and the scanned surface. The scanning optical system focuses the defelcted light beam onto the scanned surface and keeps the scanned surface and a light beam deflecting point in substantially conjugate relationship in an auxiliary scanning direction for thereby correcting facet errors of the light deflector. The scanning optical system has a saddle-shaped convex toroidal surface having a radius of curvature in a cross section along the auxiliary scanning direction, the radius of curvature being progressively greater in a direction away from the optical axis of the scanning optical system. The scanning optical system satisfies the following condition:

A semiconductor laser source unit includes a semiconductor laser chip emitting a laser beam, a base member supporting the semiconductor laser chip, and a protection cover mounted on the base member so as to seal the semiconductor laser chip. The protection cover has a lid portion formed at an end thereof and an opening at an opposed end thereof facing the base member. The lid portion has a window. The semiconductor laser source unit also has a single aspherical lens fastened to the lid portion of the protection cover so as to cover the window formed in the lid portion. The single aspherical lens collimates the laser beam emitted from the semiconductor laser chip.

Semiconductor laser source unit

A light beam scanning device has a light source, a condenser optical system, a light beam deflector, and a light beam scanning lens. The light source radiates a light beam which is converted by the condenser optical system. The convergent light beam is then deflected at a constant angular velocity by the light beam deflector. The light beam scanning lens comprises a single lens, and the convergent light beam deflected by the light beam deflector is applied to the light beam scanning lens. The light beam scanning lens places the path of movement, caused by the light beam deflector, of a naturally focused spot where the convergent light beam converged by the condenser optical system is focused, and the scanned surface in substantially conjugate relationship. The light beam scanning lens also scans the scanned surface with the light beam at an approximately constant velocity. Between the light beam scanning lens and the scanned surface, there may be disposed a correcting optical system for correcting curvature of field in an auxiliary scanning direction, or a correcting optical system for correcting curvatures of field in main and auxiliary scanning directions.

Light beam scanning lens and light beam scanning device

A laser beam from a laser beam source is applied via a collimator lens to a rotating light deflector, deflected by the light deflector, and applied via an f.theta. lens to a surface to scan the same. The f.theta. lens comprises a single-element lens with its f.theta. characteristics well corrected. To correct the curvature of field by the f.theta. lens, the collimator lens is vibrated in simple harmonic motion along the optical axis thereof, or the laser beam source is vibrated in simple harmonic motion along the optical axis of the collimator lens, in synchronism with the scanning of the surface with the laser beam.

Growing community of inventors

Yokohama, Japan

Katsumi Yamaguchi