Automatic lawn mower
First Claim
1. Guidance apparatus for a self-propelled mower comprising:
- first sensor means, including several photosensitive receptors and light source means for directing light towards said receptors, for producing output signals associated with each said receptor dependent upon the light received by each said receptor;
first comparator means for comparing predetermined combinations of said output signals and for producing comparator output signals dependent upon said comparisons; and
control means for producing guidance signals for a self-propelled mowing apparatus in response to the content of said comparator output signals, said photosensitive receptors being in an array whose principal dimension is essentially transverse to the normal direction of travel of the mower, the path of light from said light source means to said receptors being such that the presence of a substance to be mowed in the vicinity of one of said receptors affects the amount of light received by said receptor, said control means and said first comparator means including means responsive to said several receptors for detecting a boundary between mowed and unmowed vegetation.
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Accused Products
Abstract
An automatic lawn mower operable to cut about the periphery of a lawn, moving inwardly, and automatically shutting off at the conclusion of the cutting operation. A cut border is placed about the periphery of the lawn to be mowed and also about any obstacles within the area. The mower utilizes an array of light sensitive resistors and a columnized light source to detect the transition between cut and uncut grass in order to track in an irregularly shaped spiral to the center of the lawn. A portion of the sensor system provides for proper guidance of the mower around the cut perimeter of any obstacles in the cutting area. The mower may utilize an array of light sensitive resistors, a columnized light source and actuated light reflectors to detect the transition between cut and uncut grass in order to track in an irregularly shaped spiral to the center of the lawn.
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Citations
30 Claims
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1. Guidance apparatus for a self-propelled mower comprising:
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first sensor means, including several photosensitive receptors and light source means for directing light towards said receptors, for producing output signals associated with each said receptor dependent upon the light received by each said receptor; first comparator means for comparing predetermined combinations of said output signals and for producing comparator output signals dependent upon said comparisons; and control means for producing guidance signals for a self-propelled mowing apparatus in response to the content of said comparator output signals, said photosensitive receptors being in an array whose principal dimension is essentially transverse to the normal direction of travel of the mower, the path of light from said light source means to said receptors being such that the presence of a substance to be mowed in the vicinity of one of said receptors affects the amount of light received by said receptor, said control means and said first comparator means including means responsive to said several receptors for detecting a boundary between mowed and unmowed vegetation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. Guidance apparatus for a self-propelled mower comprising:
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first sensor means for detecting a differential of vegetation height of a first boundary of a mowing area; second sensor means for detecting a differential of vegetation height at a second boundary of a mowing area; and control means for producing guidance signals for a self-propelled mower suitable for use in tracking either said first or second boundary in response to detection of a differential of vegetation height by said second sensor means when said first sensor means does not detect a boundary but said second sensor means does detect a boundary and by said first sensor means when said first sensor means does detect a boundary. - View Dependent Claims (19)
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20. Guidance apparatus for a self-propelled mower comprising:
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first sensor means positioned to the side of the mower in its normal direction of travel nearest the outer boundary of a mowing area; second sensor means positioned to the side of the mower in its normal direction of travel farthest from the outer boundary of a mowing area; multiple detector means within each of said first and second sensor means, said detector means including detectors positioned to monitor an assigned area of vegetation within its path, said detectors positioned in an array whose principal sensing dimension is essentially transverse to the normal direction of travel of the mower, each of said detectors including means for producing a detector output signal dependant upon the vegetation height within its path; comparator means for producing comparisons of predetermined combinations of said detector output signals and for producing comparator output signals dependent upon said comparisons, said comparator means coupled to said first and second sensor means; processing means for converting comparator output signals to control signals, said processing means coupled to said first and second sensor means, said processing means including means for providing a status indication signal of the presence of a vegetation height differential within the monitored areas of the detectors within an array, said processing means also including means for providing a location indication signal dependent upon the location of transition of vegetation heights within the monitored areas of said detectors; and control means for producing guidance signals for a self-propelled mower from the status indication signal and the location indication signal of said processing means.
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22. Guidance apparatus for a self-propelled vehicle comprising:
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sensor means including a plurality of switches in an array whose principal dimension is essentially transverse to the normal direction of travel of the vehicle, said sensor means operable to produce output signals associated with each switch dependent upon the closed or open status of said switch; a plurality of actuator means each for controlling the closed or open status of one of said plurality of switches dependent upon the height of vegetation within its path; comparator means operable to produce comparisons of predetermined combinations of said output signals and for producing comparator output signals dependant upon said comparisons; and control means operable to produce guidance signals for a self-propelled vehicle in response to the content of said comparator output signals. - View Dependent Claims (21, 23, 24, 25, 26, 27)
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28. Guidance apparatus for a self-propelled mower comprising:
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sensor means, including several detectors positioned in an array whose principal sensing dimension is essentially transverse to the normal direction of travel of the mower, each of said detectors positioned to monitor an assigned area of vegetation within its path, each of said detectors producing a detector output signal dependent upon the vegetation height within its path; comparator means operable to produce comparisons of predetermined combinations of said detector output signals and for producing comparator output signals dependent upon said comparisons; processing means for converting comparator output signals to control signals, said processing means providing a status indication signal of the presence of a vegetation height differential within the monitored areas of the detectors within the array, said processing means also providing a location indication signal dependent upon the location of transition of vegetation heights within the monitored areas of the detectors; control means for producing guidance signals for a self-propelled mower from the status indication signal and the location indication signal of the processing means. - View Dependent Claims (29, 30)
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Specification