Abstract: A distance measuring instrument having a sighting device is disclosed, which includes a transmitter for emitting an optical radiation, a receiving lens for the optical measurement radiation remitted or scattered by an object being measured, a receiver, located behind the receiving lens, for converting the optical radiation into electrical measurement signals, and a signal processing system for comparing the measurement signals with reference signals in order to determine from them the distance from the object being measured and to make the result available to the user. The sighting device includes a photoelectric picture-taking system, which is connected to an electronic display device, and an evaluation unit for forming the differential value for the pictures taken. The photoelectric picture-taking system of the sighting device and the electronic display device are disposed in a common housing which is equipped with a separate viewfinder lens for the photoelectric picture-taking system.

Abstract: The invention relates to an optical inclinometer, in which radiation is emitted form a radiation source. After passing through a receptacle containing at least one first medium, said radiation is reproduced in a camera. Information concerning the inclination of the inclinometer can be gathered from the position of the first medium, in particular a liquid level, in relation to the inclinometer or the camera. The recording of the position of the first medium by a camera permits the evaluation of a plurality of characteristics, in particular the form, dimension and position of a boundary layer.

Abstract: The invention relates to a method for measuring distances, based on the phase measurement of an optical measuring beam that is reflected or scattered by an object, on which the beam is sighted. According to said method, the measurement object is exposed to an optical measuring beam of modulated intensity emitted by a measuring device and is converted into electrical measurement signals. The signals are then compared with a reference signal that is generated from the detection and conversion of a portion of measuring light that has been guided on a known reference trajectory, in order to determine the distance between the measuring device and the measurement objet, based on the phase difference that has been determined. The emitted measuring beam is modulated in bursts and the measurement signal of the receiver is only evaluated during the active burst period. The invention also relates to devices for carrying out said method.

Abstract: In a method and a device for carrying frequency synthesis, in particular in a distance measuring device based on the principle of evaluating the change over time in the phase of an electromagnetic radiation emitted by a radiation source and remitted by an object aimed at, a frequency, which is preferably furnished by a quartz oscillator, is regulated in a ring oscillator with N delay elements (V1, V2, V3, . . . , VN) to a desired first high frequency (F), which is used as a mixer frequency or as a modulation frequency. The signals at the N delay elements (V1, V2, V3, . . . , VN) are delivered to a multiplexer, which is switched over with a cadence that is equivalent to 2*N times the frequency of the low-frequency measurement signal to be evaluated to produce a modulation frequency or mixer frequency.

Abstract: A distance measuring instrument having a sighting device is disclosed, which includes a transmitter for emitting an optical radiation, a receiving lens for the optical measurement radiation remitted or scattered by an object being measured, a receiver, located behind the receiving lens, for converting the optical radiation into electrical measurement signals, and a signal processing system for comparing the measurement signals with reference signals in order to determine from them the distance from the object being measured and to make the result available to the user. The sighting device includes a photoelectric picture-taking system, which is connected to an electronic display device, and an evaluation unit for forming the differential value for the pictures taken. The photoelectric picture-taking system of the sighting device and the electronic display device are disposed in a common housing which is equipped with a separate viewfinder lens for the photoelectric picture-taking system.

Abstract: A system for signal acquisition in a distance meter includes at least one photoelectric receiver that detects electromagnetic radiation that is high-frequency modulated via a modulation frequency and converts the same to high-frequency electrical signals (HF). A device is provided for transforming the high-frequency electrical signals (HF) supplied by the photoelectric receiver into low-frequency measuring signals (NF) that can be passed on to a signal-processing unit mounted downstream of the device. The device for transforming the high-frequency electrical signals (HF) supplied by the photoelectric receiver into low-frequency measuring signals (NF) can include at least one switch whose switching frequency is controlled by a control frequency (F) whose frequency is higher or lower than the modulation frequency by the amount of the low-frequency measuring signal.

Abstract: In a method and a device for carrying frequency synthesis, in particular in a distance measuring device based on the principle of evaluating the change over time in the phase of an electromagnetic radiation emitted by a radiation source and remitted by an object aimed at, a frequency, which is preferably furnished by a quartz oscillator, is regulated in a ring oscillator with N delay elements (V1, V2, V3, . . . , VN) to a desired first high frequency (F), which is used as a mixer frequency or as a modulation frequency. The signals at the N delay elements (V1, V2, V3, . . . , VN) are delivered to a multiplexer, which is switched over with a cadence that is equivalent to 2*N times the frequency of the low-frequency measurement signal to be evaluated. As a result, at the output of the multiplexer, a second high frequency (M) differing from the first high frequency (F) by the frequency of the low-frequency measurement signal is generated, which can be used as a modulation frequency or as a mixer frequency.

Abstract: The invention relates to a method for measuring distances, based on the phase measurement of an optical measuring beam that is reflected or scattered by an object, on which the beam is sighted. According to said method, the measurement object is exposed to an optical measuring beam of modulated intensity emitted by a measuring device and is converted into electrical measurement signals. The signals are then compared with a reference signal that is generated from the detection and conversion of a portion of measuring light that has been guided on a known reference trajectory, in order to determine the distance between the measuring device and the measurement objet, based on the phase difference that has been determined. The emitted measuring beam is modulated in bursts and the measurement signal of the receiver is only evaluated during the active burst period. The invention also relates to devices for carrying out said method.

Abstract: A system for signal acquisition in a distance meter includes at least one photoelectric receiver that detects electromagnetic radiation that is high-frequency modulated via a modulation frequency and converts the same to high-frequency electrical signals (HF). A device is provided for transforming the high-frequency electrical signals (HF) supplied by the photoelectric receiver into low-frequency measuring signals (NF) that can be passed on to a signal-processing unit mounted downstream of the device. The device for transforming the high-frequency electrical signals (HF) supplied by the photoelectric receiver into low-frequency measuring signals (NF) can include at least one switch whose switching frequency is controlled by a control frequency (F) whose frequency is higher or lower than the modulation frequency by the amount of the low-frequency measuring signal.

Abstract: A transmitter emits high-frequency modulated optical radiation which is reflected by an object and is received by a measurement receiver. Part of the transmitter radiation is decoupled as reference radiation and guided via a calibration path to a reference receiver whose electrical signals are fed to a frequency mixer. The frequency mixer and avalanche photodiodes acting as measurement receivers of the measuring radiation are interconnected directly via an electrical connection line upon which a mixer frequency acts. As a result thereof, optoelectronic calibration which completely compensates for the temperature-dependent phase shifts of the avalanche photodiodes is possible. Additionally, the phase shifts generated in the reference and receiver signals by the temperature drifts of the transmitter compensate one another. The overall accuracy of the distance measurement can be increased, particularly for short measuring times and immediately after the apparatus has been switched on.

Abstract: A device for measuring distance with a visible measuring beam (11) generated by a semiconductor laser (10), has a collimator object lens (12) to collimate the measuring beam towards the optical axis (13) of the collimator object lens (12), an arrangement to modulate the measuring radiation, a reception object lens (15) to receive and image the measuring beam reflected from a distant object (16) on a receiver, a switchable beam deflection device (28) to generate an internal reference path between the semiconductor laser (10) and the receiver and an electronic evaluation device (25) to find and display the distance measured from the object. According to the invention, the receiver contains a light guide (17') with a downstream opto-electronic transducer (24), in which the light guide inlet surface (17) is arranged in the imaging plane of the reception object lens (15) for long distances from the object and can be controllably moved (18') from this position (18) transversely to the optical axis (14).

Abstract: A device for measuring distance with a visible measuring beam (11) generated by a semiconductor laser (10), a collimator object lens (12) to collimate the measuring beam towards the optical axis (13) of the collimator object lens (12), a radiation arrangement to modulate the measuring radiation, a reception object lens (15) to receive and image the measuring beam reflected from a distant object (16) on a receiver, a switchable beam deflection device (28) to generate an internal reference path between the semiconductor laser (10) and the receiver and an electronic evaluation device (25) to find and display the distance measured from the object. According to the invention, the receiver contains a light guide (17') with a downstream opto-electronic transducer (24), in which the light guide inlet surface (17) is arranged in the imaging plane of the reception object lens (15) for long distances from the object and can be controllably moved (18') from this position (18) transversely to the optical axis (14).

Abstract: Apparatus for measuring the time delay between pulse signals, particularly in conjunction with electro-optical range finders. A coarse measurement counter counts the output of a reference oscillator, while a fine measurement interpolator determines the residual time at the start and finish of a measuring interval. Both residual times are successively determined by the same fine measurement interpolator. A delay circuit only supplies the pulse transmitter with the trigger signal when the interpolation for the start signal in the interpolator is ended. An adjustable series of test pulses is produces by a clock generator, in order to form the average value from such a series of measurements in a logic circuit. Preferably, the clock generator is synchronized with the reference oscillator, which ensures the formation of a mean value with a narrow range of errors.

Abstract: An apparatus for measuring the delay time interval between electrical pulse signals, particularly in conjunction with electrooptical range finders. A coarse measuring counter counts clock pulses from a quartz oscillator during the interval and a fine measuring interpolator determines the residual time from the end of the interval to the next clock pulse. Residual time at the start of the measuring interval is avoided by exactly synchronizating the start of measurement with a timing pulse front (n+2) of the quartz oscillator.