Kabushiki Kaisha Topcon

Topcon Corporation

Tokyo Kogaku Kikai Kabushiki Kaisha

Masahiro Ohishi

Fumio Ohtomo

Hiroshi Koizumi

Masayuki Momiuchi

Yoshiaki Goto

Yoshikatsu Tokuda

Masaaki Yabe

Mitsuru Kanokogi

Isao Minegishi

Akinobu Sugiura

Kaoru Kumagai

Hitoshi Shimizu

Kazuaki Kimura

Ken-ichiro Yoshino

Ikuo Ishinabe

Yasutaka Katayama

Yuichi Yoshimura

Naoto Miki

Toshikazu Adegawa

Masaki Takanashi

Michio Waki

Kazushige Koshikawa

Kazuhiro Shida

Hisao O Tsuka

Hitoshi Sadachika

Katsumi Yanai

Takeshige Saito

An electro-optical distance meter comprises a light source for emitting a distance measuring light, a distance measuring optical system for leading a distance measuring light to a photodetector, an internal reference optical system for leading a part of the distance measuring light as an internal reference light to the photodetector, and an arithmetic processing unit for performing a distance measurement based on light receiving results of the distance measuring light and the internal reference light, wherein the internal reference optical system comprises a condenser lens, a scattering plate for scattering the internal reference light and for forming a secondary light source, and an optical fiber for leading the internal reference light to the photodetector and the internal reference optical system is constituted in such a manner that a light component of the internal reference light emitted from an arbitrary point within a whole surface of the secondary light source enters the optical fiber.

Electro-optical distance meter

Provided is a surveying instrument including a light emitting section for emitting distance measuring light having an intensity distribution in which an intensity is high at the center and it became lower as approaching the periphery, a light receiving section for receiving the distance measuring light via a measurement object; and a distance-measurement optical system for guiding the light to the light receiving section via the measurement object. The surveying instrument performs a prism-mode and non-prism-mode measurements. The optical system includes an aperture diaphragm arranged in a distance-measurement optical path during the prism-mode-measurement. An opening of the aperture diaphragm has widths of greater than 0 and not greater than 0.5 times the full width at half maximum of the intensity distribution in a cross-section of non-prism-distance-measurement beam in the horizontal and vertical direction.

Surveying instrument

Provided is a scanning laser ophthalmoscope capable of accurately superposing multiple photographed images. The scanning laser ophthalmoscope comprises an image generating unit that generates first images based on the light reflected from first laser light and second images based on the light reflected from second laser light. An associating unit associates the first images and the second images based on the first laser light and the second laser light parallelly scanned by the scanning unit. A displacement calculating unit calculates displacements between images regarding multiple first images. The position matching unit matches the positions of multiple second images based on the processing results from the associating unit and the displacements. The superposing unit superposes the multiple second images that have undergone the position matching. The display unit displays an image obtained by superposing the multiple second images.

Scanning ophthalmic imaging apparatus

The present invention provides an electro-optical distance measurement, wherein a light from a light source () is projected toward an object to be measured (), a reflection light reflected by the object to be measured is received at a photodetection unit (), the light from the light source is received by the photodetection unit as an inner light via an inner optical path (), and a distance to the object to be measured is measured according to the result of photodetection of the reflection light and the inner light of the photodetection unit, and wherein a correction information is acquired based on the inner light, the acquired correction information is stored, a correction value is obtained from the correction information based on the reflection light and the inner light, and a distance is calculated from the correction value and the result of photodetection of the reflection light and the inner light.

Electro-optical distance measuring method and electro-optical distance measuring device

A distance measuring apparatus and method that enable high-precision and high-speed measurement by canceling variations of a delay circuit in the apparatus are provided. Pulsed light is branched into first and second reference light, and transmitted measurement light, and the difference in detection time among the first reference light along a first path with no optical variations, the second reference light along a second path with an optical delay, and received measurement light from an object to be measured is measured. The received measurement light and the first reference light are temporally separate, distance is calculated from the difference in detection time between the received measurement light and the first reference light. When the received measurement light and the first reference light are not temporally separate, distance is calculated from a difference in detection time between the first reference light and the second reference light and a difference in detection time between the received measurement light and the second reference light.

Distance measuring apparatus and distance measuring method

A distance measuring device measures a distance from a phase difference of beaten down processing signals even when fluctuations occur in a frequency of an oscillator. The distance measuring device includes a laser unit, a dividing device, a reference light receiving unit, and a measuring light receiving unit. The distance measuring device further includes an oscillator, a first mixer, a second mixer, a fourth filter, a fifth filter, a third mixer, a sixth filter, a second filter, a phase difference measuring unit, and a distance measuring unit. The phase difference measuring unit measures a phase difference of the two beat signals extracted by the sixth filter and the second filter. The distance measuring unit measures a distance based on the phase difference measured by the phase difference measuring unit.

Distance measuring device

In measuring a certain time lag between generations of two pulse signals, a time lag measuring device prevents errors in measurement results even with an error in two reference signals for measuring the time lag. The device measures a time lag between a start signal Mand a stop signal Mand includes a reference signal generating sectiongenerating two reference signals S, Shaving a phase difference &#x3c0;/2, and an amplitude detecting sectiondetects amplitudes A, Aand A, Aof the reference signals S, Sat generation timings for the start signal Mand the stop signal M, a phase difference detecting sectioncalculating a phase _ of the reference signals S according to each set of the amplitudes (A, A) and (A, A), and a correcting sectioncorrecting the calculated phase using correction data for error correction in the reference signals S, S

Time lag measuring device, distance measuring apparatus and distance measuring method

A surveying instrument and a surveying method for further minimizing a measurement error when the surveying instrument casts a light to a measuring object and receives the reflected light and measures a delay time or a distance. A reference pulse light r and a measurement pulse light oare received as a received light signal by a light receiving section, and a damping signal SU is formed from the received light signals r, o, and an amplification rate of a minute level signal in the proximity of a zero cross point Qof the damping signal SU is greatly amplified, and timing signals r', o&#x2032; are formed by using an amplified signal. Therefore, the measurement error can be minimized.

Surveying instrument and surveying method

A time difference measuring device can accurately measure a time difference between two pulse signals generated with a predetermined time difference by measuring the two pulse signals by one measurement. The time difference measuring device measures a time difference between a start signal (M) and a stop signal (M). The device has a reference signal generation unit () for generating two reference signals (S, S) having a &#x3c0;/2 phase difference. According to corresponding amplitude values (A, A) and (A, A) of the reference signals (S, S) at each generation timing of the start signal (M) and the stop signal (M), a phase difference detection unit () calculates a phase difference &#x394;&#x3b8; (=&#x3b8;stop&#x2212;&#x3b8;start) between the generation timings of the pulse signals (M, M). According to the detected phase difference &#x394;&#x3b8; and the cycle (Ts) of the reference signals (SS), a time difference calculation unit () calculates the generation time difference &#x394;t between the pulse signals (m, M).

Time difference measuring device, measuring method, distance measuring device, and distance measuring method

To provide a surveying instrument for measuring difference in required time of light or distance to an object to be measured while covering a wide dynamic range without adjusting light amount. A light pulse emanating from a light emitting sectionis divided into a reference light cast to a reference light path Fand a measurement light cast to a measurement light path Fthrough which the measurement light travels to and is reflected back from the object to be measured. These two light beams are received with a light receiving section. With a multiplex reflection optical fiber Mpinterposed in the middle of the measurement light path F, the measurement light comes out as a row of multiplex light pulses attenuating successively in light amount at a constant rate. From this row of pulses, a measurement light of approximately the same in received light level as the reference light may be selected. Based on the selected measurement light and the reference light, the difference between the time required for the measurement light traveling through the measurement light path Fand the time required for the reference light traveling through the reference light path F, or the distance to the object to be measured, is measured.

A distance measuring method for performing distance measurement by projecting a distance measuring light to an object to be measured and by receiving a reflected light, comprising: a step of projecting for scanning the distance measuring light which has at least one luminous flux with a predetermined spreading angle; a step of emitting the light by pulsed light emission at least two times during a period when the luminous flux traverses the object to be measured; a step of measuring a distance by receiving the reflected light at least two times; and a step of averaging the results of the distance measurement.

Distance measuring method and distance measuring device

A distance measuring system, which comprises a control arithmetic unit , a light emitting unit for emitting a measuring light beam and a photodetection unit for receiving a reflection light beam from an object to be measured, the system being used for measuring a distance by receiving the reflection light beam from the object to be measured, wherein the control arithmetic unit compares a signal based on the photodetection amount of the reflection light from the object to be measured as well as a result of the distance measurement with reference data prestored in the control arithmetic unit relating to the reflection of the object to be measured, and judges whether the object to be measured is a prism or a natural object based on a result of the comparison.

Distance measuring system

A measuring system comprises a light projecting unit for projecting a distance measuring light, a distance measuring optical unit for projecting the distance measuring light to an object to be measured and for receiving the reflected distance measuring light from the object to be measured, a photodetection unit for receiving the reflected distance measuring light from the distance measuring optical unit, and a distance measuring circuit for calculating a distance to the object to be measured based on a photodetection signal from the photodetection unit, wherein the light projecting unit comprises a mixing means for mixing the distance measuring light, and the distance measuring optical unit comprises an optical path switching means for switching over the distance measuring light to an outer optical path or to an inner reference optical path and for allowing the photodetection unit to receive the light, and a light amount adjusting means for adjusting a light amount of the distance measuring light received by the photodetection unit, wherein at least one of the mixing means, the optical switching means, and the light amount adjusting means comprises a hollow type motors and as a driving source, and a hollow of the motor is an optical path.

Measuring system

The present invention provides a distance measuring device for measuring a distance, comprising a light emitting unit for emitting a measuring light beam toward an object to be measured, and a photodetection unit for receiving a reflected measuring light beam reflected from the object to be measured, wherein said distance measuring device comprises a gain control unit for changing photodetection sensitivity of said photodetection unit by a bias voltage and a light amount switching unit for variably changing a light amount of the light emitting element which emits the light beam toward the photodetection unit.

Distance measuring device and method for adjusting photodetection unit of distance measuring device

An optical pulse observing device enables the clear observation of indirect laser light of pulse laser light. The optical pulse observing device to be used by a user for observing pulse illumination light directly or indirectly, includes an optical shutter means that operates for alternate opening and closing in synchronism with periodic pulses of the pulse laser light so as to open only during the duration of pulses of the pulse laser light to pass pulse laser light and external light.

Growing community of inventors

Tokyo, Japan

Masahiro Ohishi