Konica Minolta Opto, Inc.

Yayoi Eguro

Daisuke Tanahashi

Yuichi Atarashi

Takeshi Kojima

Nobuyoshi Mori

Takashi Nozaki

Tatsuo Ohta

Hiroyuki Hattori

Kazuhiro Wada

Hajime Kobayashi

Yoshiharu Masaki

Fumiaki Yoshida

Kazuhiko Ishikawa

A scanning optical system is provided with a light source device (), a deflection optical system () that deflects the light flux from the light source device () to carry our a scan in a main-scanning direction (y), and a scanning and image-forming optical system () that forms the light flux deflected by the deflection optical system () into an image on a scanning surface (H). The scanning and image-forming optical system () includes at least a first lens (). The scanning optical system satisfies a predetermined condition relating to a numerical aperture of a light flux entering the deflection optical system () in a sub-scanning direction (z), and a distance between the deflection optical system () and the first lens (). The first lens () is a plastic lens made of a predetermined resin as a base material.

Scanning optical system, optical scanning device, and image forming device

An imaging lens good in mass-productivity, compact, low in manufacturing cost, good in aberration performance is provided by effectively correcting aberrations without greatly varying the variation of the thickness of a curing resin. An imaging device having such an imaging lens and a portable terminal are also provided. A third lens (L) has a flat surface on the object side, a convex surface near the optical axis on the image side, and a concave aspheric surface around the peripheral portion within the region where a light beam passes. Therefore, it is possible to reduce the other optical aberrations such as distortion and simultaneously to design the imaging lens so that the astigmatism takes on a maximum value at the outermost portion. Hence, the resolutions at low to middle image heights are high. In addition, such a shape does not cause a large variation of the thickness of the third lens (L) from the region along the axis to the periphery. Therefore, the thickness of the third lens (L) can be small, and the material cost can be reduced.

Scan optical system, light scan device, and image formation device

A production method of an objective lens for optical pickup apparatus having a numerical aperture NA of image side of 0.80 to 0.90 is disclosed. The method includes steps of molding resin composition containing copolymer of &#x3b1;-olefin and a cyclic olefin represented by Formula (I) or (II) to form lens shape, and thermally processing the molded product under a condition at a temperature between Tg &#x2212;45&#xb0; C. and Tg &#x2212;15&#xb0; C. for 12 to 168 hours, wherein the Formula (I) and (II) is detailed in the specification.

Optical element and optical pickup apparatus

An optical element includes: an element body including a resin containing a polymer having an alicyclic structure. The optical element is treated by one of heat treatment and wet-heat treatment for 15 hours or longer at a temperature lower by 10&#xb0; C. to 30&#xb0; C. than a glass transition temperature of the resin after being formed by injecting the resin in a mold. The optical element body has a length along an optical axis of the optical element in a range of 0.5 to 3 mm, and a length in a perpendicular direction to the optical axis in a range of 3 to 5 mm.

Optical element and producing method

An optical element for use in an optical pickup apparatus includes a substrate made of resin; an antireflection layer coating the substrate and having a low refractive index layer and a high refractive index layer,

An optical element used in a bidirectional optical communication module used for bidirectional optical fiber communication by a wavelength multiplex system, comprising a diffraction grating of binary structure prepared by molding, wherein a taper is formed at a portion of the diffraction grating where light entering the diffraction grating is intercepted by a convex part of the binary structure of the diffraction grating.

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Hachioji, Japan

Yayoi Eguro