Scanning-type distance measurement device responsive to selected signals
First Claim
1. A scanning-type distance measurement device to measure distance to an object, comprising:
- a scanning light emitter to scan a beam of pulse light linearly;
a scanning position sensing device to detect a scanning position of said beam of pulse light and to output a position signal corresponding to the detected scanning position;
a photodetector device having a plurality of photodetector elements to receive portions of said beam of pulse light which are reflected from said object, said photodetector elements each outputting a beam signal;
a selective switch to select at least one of said photodetector elements and to output the beam signal corresponding to the selected at least one photodetector element; and
a control device to receive the position signal from said scanning position sensing device and the beam signal from said selective switch and to calculate a distance between said scanning-type distance measurement device and said object.
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Abstract
A scanning-type distance measurement device is responsive to selected signals to reduce interference due to stray light. An emitted beam of light is aimed to be reflected from an object and to a photodetector among a plurality of photodetectors which are positioned linearly or in two-dimensions. The outputs of the photodetectors are selected based on the position of the emitted beam of light, so that photodetectors which should not contribute to the reflected beam, based on the geometry of the emitted beam and the reflecting object, are ignored. This approach reduces the effects of stray noise from other light sources. The selection of the photodetectors is synchronized with a scanning light emitter generating the beam of light by a position signal and an angular signal so that the noise component in the output signal which is due to stray light can be kept to a minimum.
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Citations
29 Claims
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1. A scanning-type distance measurement device to measure distance to an object, comprising:
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a scanning light emitter to scan a beam of pulse light linearly; a scanning position sensing device to detect a scanning position of said beam of pulse light and to output a position signal corresponding to the detected scanning position; a photodetector device having a plurality of photodetector elements to receive portions of said beam of pulse light which are reflected from said object, said photodetector elements each outputting a beam signal; a selective switch to select at least one of said photodetector elements and to output the beam signal corresponding to the selected at least one photodetector element; and a control device to receive the position signal from said scanning position sensing device and the beam signal from said selective switch and to calculate a distance between said scanning-type distance measurement device and said object. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A scanning-type optical device to detect a scanning beam, reflected from an object, comprising:
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a scanning light emitter to scan a beam linearly; a scanning position sensing device to detect a scanning position of said beam and output a position signal; a photodetector device having a plurality of photodetector elements to receive said beam reflected from said object; a selective switch to select a beam signal from one of said photodetector elements and output said beam signal selectively; and a control device to receive said position signal from said scanning position sensing device and said beam signal from said selective switch for processing. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A scanning-type distance measurement device to measure distance to an object, comprising:
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a scanning light emitter to scan a beam of pulse light in two-dimensions; a scanning position sensing device to detect a scanning position of said beam of pulse light and to output a position signal; a scanning angular sensing device to detect a scanning angle of said beam of pulse light and to output an angular signal; a photodetector device having a plurality of photodetector elements to receive portions of said beam of pulse light reflected from the object and to output respective corresponding beam signals; a selective switch to select at least one of said photodetector elements and to output said corresponding beam signals selectively; and a control device to receive said position signal from said scanning position sensing device, said angular signal from said scanning angular sensing device, and said corresponding beam signals from said selective switch and to calculate a distance between said scanning-type distance measurement device and said object. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A scanning-type optical device to detect a scanning beam, reflected from an object, comprising:
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a scanning light emitter to scan a beam in two-dimensions; a scanning position sensing device to detect a scanning position of said beam and output a position signal; a scanning angular sensing device to detect a scanning angle of said beam and output an angular signal; a photodetector device having a plurality of photodetector elements to receive said beam reflected from said object; a selective switch to select a beam signal from one of said photodetector elements and output said beam signal selectively; and a control device to receive said position signal, said angular signal and said beam signal from said selective switch for processing. - View Dependent Claims (22, 23, 24, 25, 26)
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27. A method of determining a distance between objects, the method comprising the steps of:
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transmitting, from a first object, a sequence of light pulses targeted at a second object to be reflected from said second object to different positions on said first object; activating detectors at said different positions on said first object in a sequence determined by said sequence of light pulses transmitted; and measuring an amount of time between transmitting said sequence of light pulses and detection of a reflection thereof by the activated detectors, as indicative of said distance between said first and second objects. - View Dependent Claims (28, 29)
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Specification