Asahi Kogaku Kogyo Kabushiki Kaisha

Pentax Corporation

Asahi Kogaku Kogyo K.k.

Shuji Yoneyama

Takayuki Ito

Sachio Hasushita

Ken Hirunuma

Tetsuya Abe

Koichi Maruyama

Ryota Ogawa

Shinya Suzuka

Moriyasu Kanai

Atsumi Kaneko

Gouji Funatsu

Nobutaka Minefuji

Hirofumi Matsuo

Ichiro Taguchi

Hidetaka Yokota

Takashi Enomoto

Takayuki Sensui

Isamu Hirai

Masami Shirai

Kiyoshi Kawano

A binocular telescope with a photographing function comprises a pair of telescopic optical systems, a photographing optical system, and a pair of reticle elements, on which reticles are formed. The reticle elements are provided in the telescopic optical systems for focusing the telescopic optical systems. The distance between the optical axes of the telescopic optical systems can be adjusted, so that the reticle images are fused. The shapes of the fused reticle images are geometrically non-coordinate with each other.

Binocular telescope with photographing function

A zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group, and a positive fourth lens group. Upon zooming, the second lens group moves from the object side to the image side, and the fourth lens group moves in order to compensate the move of the image plane. The fourth lens group includes sub-lens groups, wherein a first sub-lens group satisfies specific conditions. The first sub-lens group has an aspherical surface on at least the object-side surface thereof. The aspherical surface is formed so that the higher a height from the optical axis in a radial direction becomes the weaker the refractive power is, compared with a paraxial spherical surface.

Zoom lens system

In an optical viewer instrument with a photographing function, there is provided a telescopic lens system for observing objects, and a digital camera system including a solid-state image sensor and a photographing lens system associated with each other such that an object is formed as a photographed image on the solid-state image sensor through the photographing lens system. A manually-operable focussing mechanism is associated with the telescopic lens system and the photographing lens system such that the object is brought into focus through the telescopic lens system, and such that the object is brought into focus through the photographing lens system. Optical parameters are selected such that predetermined conditions are fulfilled, whereby the focussing of the telescopic lens system and the focusing of the photographing lens system can be suitably and properly performed by the focussing mechanism.

Optical viewer instrument with photographing function

A reference plate is situated on an optical axis of an eyepiece. The reference plate includes a first glass plate and a second glass plate. One surface of the first glass plate and one surface of the second glass plate are bonded. Cross hairs are formed on the bonded surface of the first glass plate by using a chromium plating and so on. A radius of curvature of the bonded surface accords with the field curvature of the sagittal image surface of the eyepiece.

Viewing device

In an optical viewer instrument with a photographing function, a telescopic lens system for observing an object and a digital camera system for photographing the object are housed in a casing. A manually-operable rotary wheel is rotatably provided in the casing such that a portion of the rotary wheel is exposed to the outside from the casing to bring the object into focus through the telescopic lens system. A display panel unit for displaying the object as a motion picture on a display screen thereof is mounted on the casing so as to be movable between a retracted position, where the display screen of the display panel unit is close to a wall surface of the casing, and a display position, where the display screen of the display panel unit is directed to the ocular-lens-system side of the telescopic lens system. The rotary wheel is arranged such that the exposed portion of the manually-operable rotary wheel is hidden behind the display panel unit when being at the retracted position.

A wide-angle zoom lens system includes a negative first lens group, a positive second lens group, a positive third lens group, a negative fourth lens group, and a positive fifth lens group. Upon zooming from the short to the long focal length extremities, the first lens group moves toward the image and thereafter moves toward the object, the distance between the first and second lens group decreases, the distance between the second and third lens groups decreases, the distance between the third and fourth lens groups increases, and the distance between the fourth and fifth lens groups decreases.

Wide-angle zoom lens system

A wide-angle zoom lens system includes a negative first lens group, a positive second lens group, and a positive third lens group, in this order from the object. Upon zooming from the short focal length extremity to the long focal length extremity, the distance between the first lens group and the second lens group decreases, and the distance between the second lens group and the third lens group decreases.

A viewing optical system includes an objective optical system and an eyepiece optical system. The objective optical system includes a positive first meniscus lens element having the convex surface facing toward the object, a positive second meniscus lens element having the convex surface facing toward the object, a negative third lens unit constituted by two negative lens elements, and a positive fourth lens element. The fourth lens constitutes an image-blur correcting optical system movable in a direction perpendicular to the optical axis. The viewing optical system satisfies the following conditions: 0.5<&verbar;tan 1&deg;/(&phgr; &minus;&phgr; )&verbar;<5 (mm) . . . (1) 0.5<SF <1.0 . . . (2) wherein &phgr; designates the combined power from the positive first meniscus lens element to the positive fourth lens element; &phgr; designates the combined power from the positive first meniscus lens element to the negative third lens unit; and SF designates the shape factor of the positive fourth lens element defined as SF &equals;(r &plus;r )/(r &minus;r ); r designates the radius of curvature of the object-side surface of the positive fourth lens element; and r2 designates the radius of curvature of the image-side surface of the positive fourth lens element.

Viewing optical system with an image-blur correcting optical system

An intermediate telephoto lens system includes a first lens group and a second lens group. The first lens group includes a first lens element, a second lens element, a third lens element, an aperture stop, cemented lens elements constituted by a fourth lens element and a fifth lens element, and a sixth lens element. The second lens group includes a seventh lens element and an eighth lens element. Upon focusing, only the first lens group moves along the optical axis. The intermediate telephoto lens system satisfies the following condition: (&ngr;&prime; &plus;&ngr;&prime; )/2>102 . . . (1); &ngr;&prime; : the dispersion ratio of the first lens element; &ngr;&prime; : the dispersion ratio of the second lens element; &ngr;&prime;&equals;(n &minus;1)/(n &minus;n ); n : the refractive index of the d-line for each lens element; n : the refractive index of the g-line for each lens element n the refractive index of the F-line for each lens element.

Intermediate telephoto lens system

A photographing lens system including a first lens group, a second lens group, and a third lens group. The negative second lens group is moved to the image, upon focusing. The positive first lens group includes a biconvex lens element, another biconvex lens element, and a biconcave lens element. The second lens group includes cemented lens elements constituted by a meniscus lens element having the concave surface facing toward the object and a biconcave lens element. The photographing lens system satisfies the following conditions: 0.020<dX/f<0.20 . . . (1); (n &plus;n )/2>1.52 . . . (2); (&ngr; )/2>55 . . . (3); wherein dX: the traveling distance of the second lens group; f: the focal length of the entire photographing lens system when an object at infinity is in an in-focus state; n : the refractive index of the d-line of the first lens group; n : the refractive index of the d-line of the second lens group; &ngr; : the Abbe number of the first lens group; and &ngr; : the Abbe number of the second lens group.

Growing community of inventors

Saitama, Japan

Shuji Yoneyama