Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Shusuke Ono

Hiroaki Okayama

Katsu Yamada

Kiyotaka Wasa

Yasuo Nakajima

Hisayuki Ii

Kazutake Boku

Michihiro Yamagata

Yasuhiro Tanaka

Yoshiharu Yamamoto

Osamu Yamazaki

Tsuneo Mitsuyu

Ryuichiro Kuga

Yoshiaki Hirao

Yoshitomi Nagaoka

Masayuki Yoneyama

Tomohiko Sasano

Tsuyoshi Kakimoto

Yoshito Miyatake

Motonobu Yoshikawa

Hiroyuki Asakura

Shigeru Hayakawa

Kenzo Ohji

Ritsuo Inaba

Keizo Ishiguro

Hiromichi Tanaka

Masaki Hirokoh

Rieko Hiramoto

Shinji Hataji

Provided from the object side are a first lens group () having a positive refracting power and fixed to the image plane, a second lens group () having a negative refracting power and a magnification varying action exhibited when moving along the optical axis, a third lens group () fixed to the image plane and having a positive refracting power, and a fourth lens group () movable along the optical axis so as to maintain the image plane moving with the movements of the second lens group () and of the object in a fixed position from a reference plane. Hence the movement of the image due to camera shake is corrected by moving the whole third lens group () vertically to the optical axis. The size is reduced and the aberrations are small because the whole groups whose optical performance is united are decentered.

Zoom lens, still image camera comprising the zoom lens, and video camera comprising the zoom lens

A device for calculating diffraction efficiencies of a diffraction lens divided into a plurality of regions, each region comprising at least one grating ring, comprises a first memory for storing information about diffraction efficiencies of the regions; a second memory for storing information about weights corresponding to the regions; and a first processor for retrieving information from the first and the second memory, and calculating diffraction efficiencies of the entire diffraction lens using the formula Thus, the diffraction efficiency of the diffraction lens can be calculated easily.

Device for calculating diffraction efficiencies of a diffraction lens, lens with grating element, and optical system for reading

A zoom lens is described that includes: a first lens group having positive refracting power and fixed with respect to an image plane; a second lens group having negative refracting power and varying power, wherein the power is varied by moving along an optical axis; a third lens group having positive refracting power and fixed with respect to the image plane; and a fourth lens group having: positive refracting power and moving along an optical axis so as to keep the image plane varied by movement of the second lens group and an object at a predetermined position from a reference surface. The first, second, third, and fourth lens groups are disposed from the object side to the image plane side in this order. The second lens group is composed of two negative lenses and one positive lens. The third lens group is composed of two positive lenses and one negative lens. The fourth lens group is composed of a positive lens. The second to fourth lens groups include at least one aspherical surface, respectively.

Zoom lens and video camera using the same

A zoom lens comprising, in the order of an increasing distance from an object; a fixed first lens group ( ) having a positive refractive power; a second lens group ( ) containing an aspherical surface, having a negative refractive power and being in charge of a variable power action by being moved; a fixed third lens group ( ) containing an aspherical surface and having a positive refractive power; and a fourth lens group ( ) containing an aspherical surface, having a positive refractive power and moving while following up a moving object point; wherein the surface on the image plane side of a lens positioned closest to the image plane in the third lens group ( ) has a concave plane having a strong refractive power with respect to the image plane and a relation, 2.0<L/CL <2.3, is satisfied when an effective aperture of a lens ( ) positioned closest to the object in the first group is CL and a distance from the lens ( ) to the image plane is L, whereby a high magnification, compact and wide-angle zoom lens having its aberration adequately corrected can be obtained with a simple configuration.

Zoom lens and video camera and electronic still camera using this

An optical system that can be used in an optical imaging system and displays good imaging performance with corrected chromatic aberration without increasing the number of lenses is provided by employing a lens surface with a diffractive effect. The optical system uses a lens with a concave incident surface and positive refractive power. A grating element surface 40 with positive refractive power is formed on at least one surface of the lens. The surface on which the grating element is formed is an aspherical surface with a radius of curvature that becomes bigger with increasing distance from the optical axis.

Optical system with grating element and imaging device using the same

Zoom lens system

A compact zoom lens comprising a small number of lenses, providing an aperture of about F1.4 and a zoom ration of about 14, with a full angle of view at the wide angle end of 64.degree. or wider. The zoom lens of the present invention comprises, aligned respectively from the object side, a fixed first lens group, comprising a lens with a negative refracting power, a lens with a positive refracting power, and a meniscus lens with a positive refracting power; a movable second lens group to provide zooming effect, comprising a lens with a negative refracting power, a biconcave lens with a negative refracting power, and a lens with a positive refracting power, with at least one surface of these lenses aspheric; a fixed third lens group with a positive refracting power, with at least one surface of these lenses aspheric; a fourth lens group, movable for compensating the position of the focal plane, with a positive refracting power, with at least one surface of the lenses aspheric. The below mentioned formula (1) is satisfied,

Zoom lens and video camera comprising the same

A plurality of types of ink having different wavelength characteristics are used for multiple printing of code information. When two or more types of ink are to be printed in an overlapping manner, in a region 8 in which one type of ink 4 and another type of ink 5 are printed in the overlapping manner, the ink 4 and the ink 5 are printed so as not to completely overlap each other by using a checkered pattern 9. As a result, the multiple printing can be performed without strict constraints on the wavelength characteristics of the ink.

Code sheet representing multiple code information and method for

The aspherical zoom lens of the invention includes sequentially from an object side: a first lens group which has a positive refractive power and is fixed relative to an image plane; a second lens group which has a negative refractive power and is movable on an optical axis of the aspherical zoom lens so as to have a magnification changing function; a third lens group which has a positive refractive power and is fixed relative to the image plane so as to have a light converging function; and a fourth lens group which has a positive refractive power and is movable on the optical axis so that the image plane displaceable in response to travel of the second lens group and movement of the object is fixed at a position spaced by a predetermined distance from a reference face. An air space is provided between the third and the fourth lens groups. When viewed sequentially from the object side, the first lens group includes a negative lens, a positive lens and a meniscus positive lens, the second lens group includes a meniscus negative lens, a double concave lens and a positive lens, the third lens group includes a single lens having at least one aspherical face and the fourth lens group includes a cemented doublet and a positive lens, at least one of which has at least one aspherical face.

Aspherical zoom lens

A wide-conversion lens for attachment to a master lens system consists of a bi-negative first lens in a object side and a bi-positive second lens in a master lens side, and in the second lens its radii of curvature of both surfaces are selected the same.

Wide-conversion lens and a zoom lens with it

A first lens group having a negative refracting power and a second lens group having a positive refracting power are arranged in order from the photographing object side. Zooming is performed by changing the aerial interval between the first and second lens groups, and both the first and second lens groups have one or more aspheric surfaces. The first lens group includes two negative lenses and a positive lens which are arranged in order from the object side, and the second lens group includes a positive lens, a cemented lens having a positive lens and a negative lens, and a positive lens which are arranged in order from the object side.

Wide-angel aspheric zoom lens

A two-dimensional optical low-pass filter includes an optical phase grating having a plurality of unitary grating periods on only one side of a grating plane. Each of the unitary grating periods includes at least two phase retardation structures spaced from each other, thereby providing phase retardation across the grating plane. The two phase retardation structures invariably have at least one non-continuous phase retardation configuration substantially in all directions on the grating plane.

Two-dimensional optical low-pass filter

In a wavelength-selective phase-grating type optical low-pass filter including at least a pair of adjacent first and second transparent layers, there is provided at least one adhesive layer through which a pair of adjacent first and second transparent layers stacked on each other in a phase grating form for generating a phase difference distribution on the boundary surface between the pair of adjacent first and second transparent layers. The optical low-pass filter satisfies the following conditions under a condition of 470 nm&lt;.lambda.&lt;580 nm: (a) No (.lambda.)=Ni (.lambda.), (b) .nu.d1&lt;.nu.d2 or .nu.d1&gt;.nu.d2, and (c) 0.9&lt; Np(.lambda.) / No(.lambda.)&lt; 1.1, where .lambda. is a wavelength of light passing through the optical low-pass filter, No (.lambda.) and Ni (.lambda.) are refractive indexes of the first and second transparent layers, respectively, at the wavelength .lambda., .nu.d1 and .nu.d2 are Abbe's numbers of the first and second transparent layers, respectively, No(.lambda.) is a refractive index of the adhesive layer at the wavelength .lambda., Np(.lambda.) is a refractive index of either one of the first and second transparent layers at the wavelength .lambda., thereby obtaining such low-pass effects as preventing decrease of an MTF value of the wavelength band of green.

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Takatsuki, Japan

Shusuke Ono