Olympus Corporation

Olympus Optical Company, Ltd.

Olympus Imaging Corporation

Nippondenso Co., Ltd.

Noriyuki Iyama

Shinichi Mihara

Nobuyuki Watanabe

Yuko Kobayashi

Fumiyuki Shiratani

Hiroyuki Minakata

Yuji Miyauchi

Takanori Yamanashi

Katsuhiro Takada

Atsujiro Ishii

Ayami Imamura

Nobuyoshi Toyohara

Ken Kawamata

Joji Sakamoto

Kazuyoshi Sumiya

Fumito Orii

Kazuyuki Hosokawa

Toshihide Takechi

An imaging optical system consists of, in order from its object side, a front lens group of negative refracting power, and a rear lens group of positive refracting power. A lens component is defined by a lens body having only two surfaces: an object side surface and an image side surface in contact with air on an optical axis. The front lens group comprises, in order from its object side, a first lens component concave on its image side and having negative refracting power, and a second lens component concave on its image side and having negative refracting power. The rear lens group comprises, in order from its object side, a third lens component convex on its object side and having positive refracting power, and a fourth lens component having positive refracting power. The sum of the total number of lens components in the front lens group and the total number of lens components in the rear lens group is 4. The third component comprises a plastic positive lens that includes an aspheric surface and satisfies the following conditions (1-1) and (1-2):19&#x3c;&#x3bd;3&#x3c;29&#x2003;&#x2003;(1-1)1.59&#x3c;n3&#x3c;1.80&#x2003;&#x2003;(1-2)where &#x3bd;is the Abbe constant of the plastic positive lens in the third lens component, and nis the d-line refractive index of the plastic positive lens in the third lens component.

Imaging optical system, and imaging apparatus incorporating the same

An imaging apparatus has the function of an optical zoom which optically converts the magnification of an image and the function of an electronic zoom which changes the size of an image by electrical signal processing. The function of the electronic zoom at least operates when the optical zoom is not set at the telephoto end. A total magnification is determined by changing magnification by the optical zoom and changing magnification by the electronic zoom. A pixel count sof an electronic imaging device, a pixel count sof a rectangle including the pixels on an imaging device which are used by the electronic zoom, and a pixel count sof an output satisfy sssor sss

Imaging apparatus

An imaging apparatus comprises an optical magnification changing mechanism which optically changes a magnification of an image, and an electronic magnification changing mechanism which reduces or expands a magnification with respect to image data by signal processing, the imaging apparatus providing a magnification-changed image according to a predetermined magnification based on the optical magnification changing mechanism and the electronic magnification changing mechanism. The optical magnification changing mechanism has at least two magnifications W and T (W&#x3c;T) which are discrete each other, and has a switching mechanism which, when a predetermined magnification M (W&#x3c;M&#x3c;T) has been set, switches an image obtained by the magnification W and an expanding conversion using the electronic magnification changing mechanism and an image obtained by the magnification T and a reducing conversion using the electronic magnification changing mechanism.

A zoom optical system that comprising: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a third lens unit having a positive refractive power which are arranged in order from an object side, a space between the lens units being changed to perform variation of magnification, the first lens unit includes a negative lens, the second lens unit includes a positive lens and a negative lens in order from the object side, the third lens unit includes a positive lens, and an electronic equipment provided with the zoom optical system.

Zoom optical system and electronic equipment using the same

An imaging optical system includes in order from an object side thereof: a front lens unit having a negative refracting power, an aperture stop, and a rear lens unit having a positive refracting power. The front lens unit includes in order from the object side, a first lens having a negative refracting power. The rear lens unit includes in order from the object side, a second lens which is a positive lens, a third lens which is a negative lens, and a fourth lens which is a positive lens. The imaging optical system satisfies conditional expressions (1) and (2): 1.6&#x3c;|f|/F&#x3c;5 . . . (1); 1.2&#x3c;f/F&#x3c;5 . . . (2); where Fdenotes a focal length of the overall imaging optical system, fdenotes a focal length of the front lens unit, and fdenotes a focal length of the rear lens unit.

Imaging optical system and image pickup apparatus using the same

An image forming optical system comprises, in order from an object side, a front lens group having negative refracting power, and a rear lens group having positive refracting power, wherein said front group comprises, in order from the object side, a first lens element having the negative refracting power, and a second lens element of a meniscus form having a convex surface directed toward an image side; wherein said first lens element has an aspherical surface that is a concave surface directed toward the object side in the vicinity of the optical axis, and negative refracting power at a position on the aspherical surface becomes weak as a distance between the position and the optical axis becomes large, and a surface directed toward the image side that is concave at least in the vicinity of the optical axis; and further the following conditions (1) and (2) are satisfied:1.0&#x3c;|&#x3c;10&#x2003;&#x2003;(1)1.0&#x3c;&#x3c;10&#x2003;&#x2003;(2)where Fis a focal length of the whole optical system, fis a focal length of said front group, and fis a focal length of said rear group.

Image forming optical system

An imaging apparatus comprises an optical magnification changing mechanism which optically changes a magnification of an image, and an electronic magnification change mechanism which reduces or expands a magnification with respect to image data by signal processing. The optical magnification changing mechanism is configured so that a magnification is discrete and a focal position changes together with a focal distance. The electronic magnification change mechanism carries out an interpolation process such that the number of pixels is increased with respect to a predetermined region of read image data during an expanding process, and carried out a process for discretely sampling a wide region as compared with a readout region obtained by the sampling provided when no magnification conversion is made, during a reducing process, thereby offsetting a change of the focal position in the optical magnification changing mechanism.

An optical system includes a plurality of optical elements having finite refractive power and an electronic imaging device disposed at an image side of the optical system. At least one of the plurality of optical elements is made of resin, and an infrared-cut coating is applied to at least one face of the optical element that is made of resin.

Optical filter, method of manufacturing optical filter, optical system, and imaging apparatus

The invention relates to an electronic image pickup system that enables a wide image-pickup, and ensures that even when an image is printed, sufficient image quality and clearness are obtained from the center to as far as the margin of the image and the image of a subject is depicted with a sense of extension. The electronic image pickup system comprises an image-formation optical systemfor forming an image of a subject and an electronic image pickup devicelocated on an image side of the image-formation optical system for obtaining image information on the image. The angle between the farthest-off-axis chief ray incident on the farthest off-axis site on an image pickup plane of the electronic image pickup device and an axial chief ray incident on the center of the image pickup plane satisfies condition (1) for determining the angle of view suitable to obtain the sense to extension demanded for landscape photography and sharpness all over the image and condition (2) for allowing a light bundle incident on the image pickup device to be substantially vertically incident on the image pickup plane. The image pickup devicesatisfies condition (3) for determining the effective number of pixels on the image pickup device or the maximum number of recording pixels by signal processing.

Image pickup system

The invention has for its object to use a zoom system that comprises a reduced number of lens elements, is compact and simplified, and has high image-formation capability, thereby achieving thorough size reductions in video cameras or digital cameras. A zoom lens for use on an image pickup system comprises a first lens group Gnegative power comprising an aspheric negative lens element and a positive lens element, a second lens group Gcomprising a positive single lens element, a positive doublet wherein a positive and a negative lens element are cemented together in this order and which is in a meniscus form convex toward an object side of the zoom lens and a positive single lens element, wherein two or more surfaces except the cementing surface of the doublet are each defined by an aspheric surface, and a third lens group Gcomprising one positive lens component. For zooming from the wide-angle end to the telephoto end of the zoom lens, the second lens group Gmoves only toward the object side of the zoom lens, and the third lens group Gmoves in a locus different from that of the second lens group G. For focusing, the third lens group Gmoves. Condition (1) for the shape factor of the object side-positive lens element in the second lens group Gand condition (2) for the magnification of the second lens group Gare satisfied.

A zoom lens system for compact cameras comprising a first positive lens unit, a second positive lens unit and a third negative lens unit: the first lens unit comprising at least a positive lens component which is disposed on the object side, and a negative meniscus lens component which is disposed on the image side of the positive lens component and has a concave surface on the image side. The zoom lens system is configured to perform zooming by varying an airspace reserved between the first lens unit and the second lens unit as well as an airspace reserved between the second lens unit and the third lens unit, and has a high zoom ratio and high optical performance.

Zoom lens system

A zoom lens system for use on compact cameras, which has a high zoom ratio, is provided at a minimum cost. The zoom lens system comprises a first positive lens group G1, a second positive lens group G2 and a third negative lens group G3 with a focal length of the system varied with changes in spacings between the lens groups. The first lens group G1 comprises one positive lens and one negative lens, and the third lens group G3 consists of one negative plastic lens. The zoom lens system satisfies

The invention relates to a zoom lens system which, albeit having a zoom ratio as high as about 3.4, is quite well corrected for aberrations from the wide-angle to telephoto end thereof, and comprises a very reduced number of lenses involved. The zoom lens system comprises a plurality of lens groups (G1 and G2) with spaces therebetween, wherein at least one of said spaces is varied for zooming. The lens group G2 having negative refracting power is located nearest to the image surface side of the system, and includes at least one lens having positive refracting power, which is made of a gradient index lens having a refractive index varying in a direction perpendicular to the optical axis of the system. This gradient index lens has an aspheric surface on at least one side, and at least one lens having negative refracting power is located on the image surface side with respect to that gradient index lens.

A camera having a focus detecting optical system includes a quick-return mirror having the function of splitting the optical path of a light beam coming from a photographic lens into two so that one is reflected and the other is transmitted, a submirror attached to the quick-return mirror, and an imaging plane disposed at a position of an imaging surface of the photographic lens. The focus detecting optical system including a field mask, a condenser lens placed close to a preset imaging plane equivalent to the imaging plane of the photographic lens, a photoelectric converting element array, and a reimaging optical system for re-forming an image formed by the photographic lens on the photoelectric converting element array. An aspect ratio AR of the imaging plane satisfies the following condition: 0.4&lt;AR&lt;0.63.

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Hachioji, Japan

Noriyuki Iyama