Asahi Seimitsu Kabushiki Kaisha

Pentax Corporation

Pentax Precision Co., Ltd.

Shunichiro Wakamiya

Homu Takayama

Masakazu Yamagata

Yoichi Kojima

Tatsuo Gotoh

Masami Shirai

Masayuki Arai

Kenji Kaneko

Eijiroh Tada

Takayasu Shishido

Toru Shikano

A surveying instrument includes a sighting telescope having an objective lens and an eyepiece; an erecting optical system functioning so that an image formed by said objective lens is viewed as an erect image through the eyepiece; and a light shield device, positioned in an optical path extending from an incident surface of the erecting optical system to an exit surface of the erecting optical system, for preventing an off-field light bundle which is incident on the erecting optical system from reaching the eyepiece.

Surveying instrument

An integral transmitter-receiver optical communication apparatus, including: a transmitter-receiver device including: a transmitter having a laser source for emitting a laser beam modulated in accordance with a transmission information signal, a receiver having a position detecting sensor and a light receiving element each of which receives a complementing modulated laser beam transmitted from a complementing transmitter, and a beam splitting device for splitting the modulated laser beam and the complementing modulated laser beam into two separate laser beams; a telescopic optical system for transmitting the modulated laser beam emitted by the laser source, and for receiving the complementing modulated laser beam transmitted from the complementing transmitter, the telescopic optical system including a first afocal optical system; a light beam deflecting device positioned between the telescopic optical system and the transmitter-receiver device, wherein the light beam deflecting device is controlled in accordance with a signal output from the position detecting sensor; and a second afocal optical system positioned between the light deflecting device and the transmitter-receiver device.

Integral transmitter-receiver optical communication apparatus and a crosstalk preventive device therefor

A surveying instrument includes a sighting telescope for sighting an object; an optical distance meter which includes a light-transmitting optical system for transmitting a measuring light toward the object via the sighting telescope, a light-receiving optical system for receiving light reflected by the object, and a light-receiving element which receives the measuring light reflected by the object and received by the light-receiving optical system; and a light shield mask positioned on an optical axis between the eyepiece and the light-receiving element to cut off incoming rays from the eyepiece.

Surveying instrument having an optical distance meter

Disclosed is an integral transmitter-receiver optical communication apparatus, including: a transmitter-receiver device which includes: a transmitter having a laser source for emitting a laser beam modulated in accordance with a transmission information signal, a receiver having a position detecting sensor and a light receiving element which receive a complementing modulated laser beam transmitted from a complementing transmitter, and a beam splitting device for splitting the modulated laser beam and the complementing modulated laser beam which are incident thereon as two separate laser beams; a telescopic optical system for transmitting the modulated laser beam emitted by the laser source and for receiving the complementing modulated laser beam transmitted from the complementing transmitter; and a light beam deflecting device positioned between the telescopic optical system and the transmitter-receiver device, wherein the light beam deflecting device is controlled in accordance with a signal output from the position detecting sensor.

Integral transmitter-receiver optical communication apparatus

An optical axis correcting system includes a first afocal optical system, an optical deflector which corrects the deviation of an optical axis of light incident upon the first optical system, a second afocal optical system, and a light convergent optical system. The optical axis correcting system satisfies (1) 3.60&lt;.vertline.fp(I)/fN(I).vertline.&lt;5.30, (2) 1.00&lt;.vertline.fp(II)/fN(II).vertline.&lt;2.41, and (3) 0.12 &lt;r1 (II)/f&lt;0.23, wherein fp(I) represents the focal length of a positive lens group of the first optical system, fN(I) represents the focal length of a single negative lens element of the first optical system, fp(II) represents the focal length of a positive lens group of the second optical system, fN(II) represents the focal length of a negative lens group of the second optical system, r1(II) represents the radius of curvature of the surface oif a positive lens element of the second afocal optical system closest to the optical deflector, and f represents the focal length of the whole optical system.

Optical axis correcting system

In a concentric ND filter in which multi-layered circular ND filter elements whose diameter is decreased stepwise toward the uppermost layer from the lowermost layer are concentrically provided on a first transparent substrate, a surrounding space of the concentrically multi-layered ND filter elements defined by and between the surface of the transparent substrate and the surface of the central ND filter layer of the smallest diameter is filled with a transparent adhesive.

Growing community of inventors

Saitama, Japan

Shunichiro Wakamiya