Fujinon Corporation

Fujifilm Corporation

Fuji Photo Optical Co., Ltd.

Yu Kitahara

Toshiaki Katsuma

Masao Mori

Tetsuya Ori

Yoko Yamamoto

Taro Asami

Makoto Oomura

Hiromitsu Yamakawa

Takeshi Kamiya

Ryoko Otomo

Provided are an imaging lens, which is a wide-angle imaging lens and is capable of satisfactorily correcting various aberrations, and an imaging apparatus which includes this imaging lens. The imaging lens consists of, in order from an object side: a first lens Lthat has a negative refractive power; a second lens Lthat has a negative refractive power; a third lens Lthat has a positive refractive power; a fourth lens Lthat has a negative refractive power; a fifth lens Lthat has a positive refractive power; a sixth lens Lthat has a positive refractive power; and a seventh lens Lthat has a negative refractive power. The following conditional expression (1) is satisfied.&#x2212;2&#x3c;12&#x3c;&#x2212;1.47&#x2003;&#x2003;(1)

Imaging lens and imaging apparatus

An imaging lens consists of, in order from the object side, a negative first lens, a positive second lens, a positive third lens, a negative fourth lens, a positive fifth lens, and a positive sixth lens. The imaging lens satisfies the condition expressions below:1/&#x3c;&#x2212;1.68&#x2003;&#x2003;(1-2),&#x2212;0.7&#x3c;4/&#x2003;&#x2003;(2),&#x2212;0.6&#x3c;(3+4)/(3&#x2212;4)&#x3c;2.2&#x2003;&#x2003;(11-2), and0.5&#x3c;2/3&#x3c;4.0&#x2003;&#x2003;(12),where f1 to f4 are focal lengths of the first to the fourth lenses, f is a focal length of the entire system, R3 is a radius of curvature of the object-side surface of the second lens, and R4 is a radius of curvature of the image-side surface of the second lens.

An imaging lens substantially consists of negative first lens, positive second lens, negative third lens, positive fourth lens, positive fifth lens, and negative sixth lens in this order from an object side. At least one of second lens through sixth lens satisfies the following conditional expression (1), and the imaging lens, as a whole, satisfies the following conditional expression (2):(1/&#x3c4;)&#xd7;()&#x3c;0&#x2003;&#x2003;(1); and&#x3a3;(1/&#x3c4;)&#xd7;()&#x3c;0 (=1 through 6)&#x2003;&#x2003;(2).

An image pickup lens having a four lens configuration in which a bi-concave first lens, a bi-convex second lens, a bi-concave third lens, and a positive fourth lens are disposed in this order from an object side. Here, at least one of the first, second, third, and fourth lenses has an aspherical surface on each side. The image pickup lens satisfies Conditional Expression (1) given below when a refractive index of the second lens with respect to d-line is taken as Nd2.1.6&#x3c;2&#x2003;&#x2003;(1)

Image pickup lens and image pickup apparatus

An objective lens for converging light emitted from a light source onto an optical recording medium to record and reproduce information consists of a single lens that has at least one aspheric surface. The following conditional expressions (1) and (2) are satisfied:&#x2212;0.90&#x3c;&#x3c;&#x2212;0.45&#x2003;&#x2003;(1)0.70&#x3c;&#x3c;1.40&#x2003;&#x2003;(2)where Rdenotes a radius of curvature (mm) of a light source side surface near an optical axis,

Objective lens, optical pickup device, and optical recording/reproducing apparatus

Disclosed is an imaging lens capable of improving weatherability, reducing performance degradation, and obtaining an optical performance excellent across a wide wavelength region from the visible wavelength region to the near-infrared wavelength region. An imaging lens for forming an image of visible and near-infrared light includes, in order from the object side: a front group that has a positive power; an aperture stop; and a rear group that has a negative power. In the imaging lens, the rear group includes a negative meniscus lens that is disposed closer to the object side and has a surface convex toward the object side, and a biconvex lens that is disposed closer to the image side. In addition, all the lenses constituting the imaging lens are single lenses.

Imaging lens and image pickup apparatus

An objective lens consists of a single lens element, and has a light source side surface formed into a convex surface having a large curvature and an optical recording medium side surface has a small curvature. The both surfaces are aspheric surfaces. Also, the objective lens satisfies the following expressions (1) to (3):0.7&#x3c;NA&#x3c;0.98&#x2003;&#x2003;(1)0.70&#x3c;&#x3c;1.40&#x2003;&#x2003;(2)0.48&#x3c;X&#x3c;0.55&#x2003;&#x2003;(3).where NA denotes a numerical aperture of the objective lens on an optical recording medium side,

Objective lens, optical pickup device having the same, and recording and/or reproducing apparatus for optical recording medium, equipped with the optical pickup device

An imaging lens includes, in order from an object side, a positive first lens group, a stop, and a positive second lens group. The first lens group includes, in order from the object side, a first lens, which is a negative meniscus lens having a convex object-side surface, and a second lens having a positive power and including a convex image-side surface. The second lens group includes, in order from the object side, a third lens having a negative power and including a concave object-side surface, a fourth lens having a positive power and including a convex image-side surface, a fifth lens, which is a biconvex lens, and a sixth lens, which is a meniscus lens having a negative power and including a convex surface facing an image side. Each of the first to sixth lenses is a single spherical glass lens.

Imaging lens and imaging apparatus using imaging lens

An objective lens consists of a single lens element. A light source side surface is formed into a convex surface having a large curvature, and an optical recording medium side surface has a small curvature. The both surfaces are formed into aspheric surfaces. Also, the objective lens satisfies the following expressions (1) to (3):0.70&#x3c;NA&#x3c;0.98&#x2003;&#x2003;(1)0.70&#x3c;d/f&#x3c;3.00&#x2003;&#x2003;(2)0.50&#x3c;&#x3c;0.80&#x2003;&#x2003;(3)

An objective lens for converging light emitted from a light source on an optical recording medium to record and reproduce information consists of a single lens having at least one aspheric surface. The following conditional expressions (1) to (3) are satisfied:&#x2266;1.75&#x2003;&#x2003;(1)0.5&#x3c;&#x3c;0.6&#x2003;&#x2003;(2)0.8&#x3c;/()&#x3c;1.0&#x2003;&#x2003;(3)where

An imaging lens includes, in order from an object side, a first lens having a negative power and including a concave image-side surface, a second lens having a positive power, a stop, a third negative lens, which is a biconcave lens, a fourth lens having a positive power, and a fifth lens having a positive power and including a convex image-side surface. The imaging lens satisfies the following conditional expressions:0.18&#x3c;(4+5)/&#x3c;0.44, and0.18&#x3c;1/where f denotes a focal length of an entire lens system, Ddenotes a thickness of a center of the first lens, Ddenotes a distance from an image-side surface of the second lens to the stop on an optical axis, and Ddenotes a distance from the stop to an object-side surface of the third lens on the optical axis.

An imaging lens includes, in order from an object side, a first lens group having a positive power, an aperture diaphragm, and a second lens group having a positive or negative power. The first lens group includes, in order from the object side, a first lens which is a biconcave lens, a second lens that has a positive power and includes a convex image-side surface, and a third lens that has a positive power and includes a convex object-side surface. The second lens group includes, in order from the object side, a fourth lens that has a negative power and includes a concave image-side surface, and a fifth lens which is a biconvex lens. Each of the first to fifth lenses is a single spherical glass lens.

An objective optical system is formed of a diffractive optical element with a diffractive surface formed on a virtual plane and an objective lens for focusing three collimated light beams of three different wavelengths at three different numerical apertures onto desired positions of three different recording media with substrates that include different thicknesses, such as an AOD, a DVD, and a CD, that introduce different amounts of spherical aberration in the focused beams. The objective optical system provides compensating spherical aberration to the three light beams by varying the distance between the diffractive optical element and the objective lens with the recording medium being used. The objective optical system focuses second-order diffracted light of one wavelength and first-order diffracted light of the other two wavelengths. An optical pickup device includes the objective optical system, the recording media, and a light source that provides the three light beams.

Objective optical system and optical pickup device using it

The imaging lens system includes a negative first lens disposed on a most object side, having a concave surface directed toward the object side and having a meniscus shape, a cemented lens LC disposed on a most image side and having a convex surface on its most object side, and an aperture diaphragm disposed just in front of the object side of the cemented lens. The system satisfies the following conditional expressions:0.05&#x3c;(2&#x2212;1)/(1+2)&#x3c;0.251 &#x2212;2 &#x3e;15where

Imaging lens system and imaging apparatus

A color image readout lens comprises, in order from an object side: a first group comprising a positive lens convex toward the object side and a biconcave negative lens; a stop; a second group comprising one diffractive optical element that has at least one flat surface and has a diffractive structure formed on the flat surface; and a third group comprising a biconvex positive lens and a negative lens concave toward the object side.

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Saitama, Japan

Yu Kitahara