Konica Minolta Opto, Inc.

Konica Minolta, Inc.

Konica-minolta Holdings, Inc.

Kazutaka Noguchi

Tohru Kimura

Yuichi Atarashi

Ryouta Ishikawa

Kazuki Matsui

Nobuyoshi Mori

Mamoru Terada

Takeshi Endo

Tetsuya Noda

Hiroshi Hatano

Hiroyuki Matsuda

Hiroaki Tanaka

Daisuke Tanahashi

Shigeru Yamasaki

A light scanning type object detecting device includes a mirror unit in which first and second mirror surfaces are formed so as to incline in respective directions intersecting with a rotation axis and to face each other with a predetermined angle, a light source; and a light receiving element. On the assumption that H represents a distance between an intersection point of extension lines of lateral sides and a bottom side in the first mirror surface, r represents a radius of a received light flux, h represents a distance between the center of the received light flux and the bottom side, and H' represents a distance between a top side and the bottom side, formulas (1) and (2) are satisfied.when&#x3c;0.4, 0.1&#x3c;&#x2264;()/&#x2003;&#x2003;(1)when&#x2265;0.4, 0.2&#x3c;&#x2264;()/&#x2003;&#x2003;(2)

Light scanning type object detecting device

Provided is an object detection device which unlikely causes vignetting of a beam reflected from a mirror surface during rotation, and fully ensures object detection performance A light projecting system and a light receiving system are disposed so that a larger one of the area of a region on a mirror surface occupied by a beam emitted from a semiconductor laser and the area of a region on the mirror surface occupied by a beam incident on a photodiode has a longer movement length on the mirror surface during rotation than a smaller one.

Optical-scanning-type object detection device having a mirror surface to be inclined in a direction crossing a rotation axis

A zoom lens includes, in an order from an object side, four groups of a positive group, a negative group, a positive group, and a negative group. For varying magnification from a wide-angle end to a telephoto end, the first group is configured to be moved toward the object side, the second group is configured to be moved toward an image side, the third group is configured to be moved toward the object side, and the fourth group is configured to be moved toward the object side, and conditional equations of &#x2212;0.63&#x3c;f/f&#x3c;&#x2212;0.25, &#x2212;10&#x3c;f/y'max &#x3c;&#x2212;3, and 6&#x3c;f/y&#x2032;max&#x3c;20 (f: the focal distance of the first group; f: the focal distance of the second group; y&#x2032;max: the maximum image height) are satisfied.

Zoom lens, imaging optical apparatus, and digital device

An optical information recording and reproducing apparatus relating to the invention employs a two-beam interference method. In the optical information recording and reproducing apparatus, a moving device moves an information recording medium between a recording and reproducing position and a retracting position, and a mirror moves together with the information recording medium. When the information recording medium moves to the recording and reproducing position, the mirror moves to a position which is displaced from the at least one of the reference beam and the information beam. When the information recording medium moves to the retracting position, the mirror moves to a position where the mirror can reflect the at least one of the reference beam and the information beam toward a detector for detecting a deviation of the at least one of the reference beam and the information beam.

Optical information recording and reproducing apparatus, and cartridge

An objective optical system according to the present invention is provided for use in an optical pickup apparatus for recording or reproducing information on an information recording surface of a first optical information recording medium using a first light flux emitted from a first light source. The objective optical system is provided with: a first lens with a positive refractive power including plastic; a second lens with a positive refractive power including plastic; and a first phase structure. A wavefront aberration change amount of the objective optical system when a wavelength of the first light flux changes, and a wavefront aberration change amount of the objective optical system when an ambient temperature of the objective optical system satisfy the predefined condition.

Objective optical system and optical pickup apparatus

The present invention provides an objective lens for optical pick-up devices in which the amount of change in the astigmatic aberration is small when there is a temperature distribution that is not circularly symmetric with respect to the optical axis within an objective lens constructed with at least two optical elements and which permits stable and high-speed information recording and reproduction with high-density optical disks, and to provide further an optical pick-up device provided with such an objective lens, and an optical information recording and/or reproducing apparatus employing such an optical pick-up device.

Objective lens for optical pick-up devices, optical pick-up devices, and optical information recording and/or reproducing apparatus

An objective optical system according to the present invention is provided for use in an optical pickup apparatus for recording or reproducing information on an information recording surface of a first optical information recording medium using a first light flux emitted from a first light source, and the objective system includes: a first lens with a positive reflective power including plastic; and a second lens with a positive refractive power including plastic. Opposite optical surfaces of the first lens are convex surfaces, and a refractive power of the first lens and a power of a whole system of the objective optical system satisfy the predefined condition.

An optical pickup device comprises a light source to emit a light flux having wavelength &#x3bb;; an objective lens including at least two plastic lenses of a first plastic lens having positive refractive power and a second plastic lens having positive refractive power, wherein the first plastic lens and the second plastic lens are arranged in this order from the light source side; and an actuator to drive the objective lens; wherein the objective lens satisfies the following expression (1-1):&#x2212;0.0004&#x3c;&#x394;3SA/(&#xb7;(1&#x2212;))&#x3c;0.0004&#x2003;&#x2003;(1-1)where &#x394;3SA (&#x3bb;RMS) represents a rate of change of a third order spherical aberration of the objective lens when the temperature of an entire body of the objective lens uniformly changes, f (mm) represents the focal length of the objective lens for the light flux having wavelength &#x3bb;, and m represents the magnification of the objective lens.

Optical pickup device, optical information recording and reproducing apparatus and objective lens

An optical system for use in an optical pickup apparatus has a chromatic aberration correcting element having plural ring-shaped zones divided with a stepped section in such a way that one of the neighboring ring-shaped zones located apart from the optical axis has a longer optical path than the other one located closer to the optical axis, and an objective lens having plural ring-shaped zones divided with a stepped section shaped in the optical axis direction in such a way that the stepped section causes a optical path difference between light fluxes having passed through the neighboring ring-shaped zones. The ring-shaped zonal structure of the chromatic aberration correcting element corrects a deviation of a focal point caused by the objective lens due to a wavelength fluctuation of an incident light flux coming into the optical system.

Growing community of inventors

Hachioji, Japan

Kazutaka Noguchi