Kabushiki Kaisha Topcon

Topcon Corporation

Goro Iwasaki

Nobuyuki Nishita

Takeshi Ishida

Jumpei Kochi

Hiroyuki Nakabe

Satoshi Yanobe

Yosuke Okudaira

Masaki Kamiki

Shinji Yamaguchi

Eiji Takeuchi

The invention provides a tilt angle measuring device, which comprises a discoid container for including a liquid forming a free liquid surface, a light emitting source for allowing a detection light to enter the free liquid surface, a photodetector for receiving the detection light reflected on the free liquid surface and a signal processing unit for detecting a tilt of the free liquid surface based on a detection signal from the photodetector, wherein the signal processing unit sets a detection light storage time of the photodetector so that an error incidence rate of the detection signal is a predetermined value.

Tilt angle measuring device

The present invention provides a measuring device, which comprises a leveling unit, a measuring device main body provided on the leveling unit, a control unit, a first tilt angle measuring device for detecting a horizontality with high accuracy, and a second tilt angle measuring device for detecting a tilt angle in a wider range than a range of the first tilt angle measuring device and having a higher responsiveness than a responsiveness of the first tilt angle measuring device, wherein the control unit, the first tilt angle measuring device and the second tilt angle measuring device are provided in the measuring device main body and wherein the control unit drives the leveling unit based on a detection result of the second tilt angle measuring device, performs a rough leveling until a tilt angle detected by the second tilt angle measuring device reaches within a range in which the first tilt angle measuring device is capable of detecting and levels the measuring device main body horizontally based on a detection result of the first tilt angle measuring device.

Measuring device

The invention provides a surveying instrument comprising a frame unit rotatable in a horizontal direction, a telescope unit as mounted rotatably in a vertical direction on the frame unit, a driving unit for rotating and driving the frame unit and the telescope unit, a horizontal angle measuring unit for detecting a horizontal angle of the frame unit, a vertical angle measuring unit for detecting a vertical angle of the telescope unit and a control device, wherein the telescope unit has a telescope for sighting an object to be measured and a wide angle camera having a wider field angle than the telescope and for acquiring an image in a sighting direction, wherein the wide angle camera is set so that a sighting position of the sun is on a photodetection element and the sighting position of the sun is at a known position deviated from a field of view of the telescope, wherein the control device detects an image of the sun and a center of the image of the sun from an image acquired by the wide angle camera and controls the driving unit so that the center of the sun coincides with the sighting position of the sun, and is adapted to determine a true north based on a time moment, a horizontal angle, a vertical angle, a deviation between an optical axis of the telescope and the sighting position of the sun, and a latitude and a longitude of a position where the surveying instrument is installed, when the center of the image of the sun coincides with the sighting position of the sun.

Surveying instrument

The invention provides a surveying instrument, which comprises a control device having a reference clock signal generating unit for producing a reference clock signal. The control device produces a time signal to indicate a standard time from a signal acquired from the GNSS device, puts a time stamp on the time signal, associates the time signal with the reference clock signal, measures a horizontal angle at a moment when the telescope unit sights the sun and acquires an image signal, puts a time stamp on the image signal, calculates a standard time at a time of image acquisition, calculates an azimuth angle of the sun at the standard time based on a latitude and a longitude of a point where the surveying instrument is installed and a standard time at the time of image acquisition, and updates a horizontal angle by the azimuth angle.

The invention provides a surveying instrument, comprising a frame unit rotatable in a horizontal direction, a telescope unit as mounted rotatably in a vertical direction on the frame unit and further for sighting an object to be measured, a horizontal driving unit for rotating and driving the frame unit in a horizontal direction, a vertical driving unit for rotating the telescope unit in a vertical direction, a horizontal angle measuring unit for detecting a horizontal angle of the frame unit, a vertical angle measuring unit for detecting a vertical angle of the telescope unit and a control device, wherein the control device is adapted to calculate a solar altitude at a time moment by setting up coordinates of where the surveying instrument is installed and the time moment, and to make the telescope unit to set to the solar altitude as calculated by controlling the vertical driving unit, to control the horizontal driving unit, to execute searching of the sun by horizontally rotating the frame unit at the solar altitude as set up, to capture the sun, to sight the sun, to detect a horizontal angle under the sighted condition based on the horizontal angle measuring unit, and to survey a true north based on the horizontal angle as detected.

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Tokyo-to, Japan

Goro Iwasaki