Maxell, Ltd.

Hitachi Maxell, Limited

Hitachi Maxwell, Ltd.

Masaki Yamazaki

Takashi Sugiyama

Akito Sakemoto

Tsuyoshi Maro

Hiroyasu Otsubo

Akihiko Soya

An imaging lens is provided with: a first lens with negative power; a second lens with negative power; a third lens with positive power; and a fourth lens with positive power. The cemented fourth lens is formed from an object side lens with negative power and an image side lens with positive power. The thickness of a resin adhesive layer that bonds the object side lens and the image side lens is 20 &#x3bc;m or greater on the optical axis, and when SgH is the amount of sag in the image side lens surface of the object side lens and SgH is the amount of sag in the object side lens surface of the image side lens. The bonding operation is easy without damage occurring to the cemented surfaces, with a design that takes into account thickness of the resin adhesive layer; therefore various forms of aberration can be corrected.

Imaging lens and imaging device

An imaging lens is formed from a first group lens having negative power, a second group lens having positive power, a third group lens having negative power, and a fourth group lens having positive power, disposed in order from the subject side to the image side. Letting f be the focal distance for the entire lens system and ff2 the focal distance for the second group lens, 1.0&#x2264;ff2/f&#x2264;2.0 is satisfied; therefore, the entire length of the lens system can be kept short and image curvature can be suppressed. In addition, each of the subject side lens surfaces and the image side lens surfaces for the second group lens, third group lens, and fourth group lens are provided with aspherical surface shapes; therefore, the imaging lens is constituted to be bright.

Wide-angle lens and imaging device

An imaging lens is provided with: a first lens with negative power; a second lens with negative power; a third lens with positive power; and a fourth lens with positive power. The cemented fourth lens is formed from an object side lens with negative power and an image side lens with positive power. The thickness of a resin adhesive layer that bonds the object side lens and the image side lens is 20 &#x3bc;m or greater on the optical axis, and when Sg1H is the amount of sag in the image side lens surface of the object side lens and Sg2H is the amount of sag in the object side lens surface of the image side lens. The bonding operation is easy without damage occurring to the cemented surfaces, with a design that takes into account thickness of the resin adhesive layer; therefore various forms of aberration can be corrected.

A biometric information acquisition apparatus includes: a light guide that guides a light beam through a plurality of light reflective surfaces; and an image pickup unit that receives the light beam output from the light guide and captures a subject image. The light guide includes an input surface that receives the subject image and is provided at a front surface side; a first light reflective surface that is opposed to the input surface and is provided at a back surface side; and a second light reflective surface that extends in a thickness direction of the light guide. A subject image can be acquired within a desired range by employing the light guide, while suppressing an increase in size of the biometric information acquisition apparatus.

Biometric information acquisition apparatus, biometric authentication apparatus, light guide, and image acquisition apparatus

An imaging module for biometrics authentication comprises: a light source irradiating a living body with light capable of passing through the living body; a prism having an incidence surface including an incidence area for taking in light emerging from the living body, two or more reflecting surfaces for reflecting the light taken in through the incidence area, and an outlet surface for outputting the light reflected by the reflecting surfaces; and a camera module including a lens for focusing the light emerging from the outlet surface of the prism and an image pickup device for converting the light focused thereon by the lens into an electric signal and outputting the electric signal.

Growing community of inventors

Osaka, Japan

Masaki Yamazaki