Method and apparatus for detecting temporal changes in an object
First Claim
1. Apparatus for detecting intensity changes between a first and a second time, at selected spatial locations of an object, comprising:
- a light sensitive target;
means disposed between said object and said target for focusing light from each of said selected spatial locations of said object on respective associated first regions of said target at said first time, and on respective associated second regions of said target at said second time; and
means for comparing the light focused on the first and second target regions associated with at least one of said selected spatial locations of said object to detect said changes.
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Abstract
Temporal changes in an object are detected by focusing light from preselected spatial locations of the object on associated first and second regions of a light sensitive target at first and second times, respectively, and by comparing the light intensity focused on the regions. The focusing apparatus includes a Ronchi grating located at an image plane between the object and a light sensitive target. At the first time, light from the object passes through the clear portions of the grating to illuminate alternate parallel stripes on the target, while at the second time, the light passing through the clear portions is shifted to illuminate the regions between the first parallel stripes. The target is then scanned, and information from associated stripes is compared to detect changes. In one embodiment, the shaft can be brought about by the use of a birefringent crystal and polarized light; alternatively, a beam splitter and a shutter arrangement can be used.
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Citations
21 Claims
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1. Apparatus for detecting intensity changes between a first and a second time, at selected spatial locations of an object, comprising:
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a light sensitive target; means disposed between said object and said target for focusing light from each of said selected spatial locations of said object on respective associated first regions of said target at said first time, and on respective associated second regions of said target at said second time; and means for comparing the light focused on the first and second target regions associated with at least one of said selected spatial locations of said object to detect said changes. - View Dependent Claims (2, 3, 4, 5, 6)
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7. Apparatus for detecting temporal intensity changes in a portion of an object comprising:
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a light sensitive target; first means for forming an image of said object portion on first and second regions of said target at first and second times, respectively; and second means for comparing said image on said first and second regions to detect said changes. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. Apparatus for detecting intensity changes at a plurality of spatial locations of an object between first and second times, comprising:
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a light sensitive target; first means for focusing an image of said spatial locations on first regions of said target at said first time; said first means including second means for shifting light travelling from said object to said target so as to focus light from said spatial locations on second regions of said target at said second time, said first and second regions being alternate stripes on said target; third means for sequentially scanning said stripes to develop a composite signal alternately containing first and second data representative of the light intensity of said preselected spatial locations of said object at said first and second times, respectively; and fourth means for comparing said first and second data to detect said changes. - View Dependent Claims (15)
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16. Apparatus for detecting intensity changes which occur in selected spatial locations of an object between first and second times, said apparatus including:
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a light sensitive target; means for filtering light reflected from said object so as to illuminate, at said first time, first alternate parallel regions of said target; means for shifting light passing through said filtering means so as to illuminate, at said second time, second alternate parallel regions of said target, said second regions being interlaced between said first regions; means for scanning said target in a direction perpendicular to said regions to generate a signal alternately indicative of the intensity of particular ones of said spatial locations at said first and second times; and means for comparing said alternate indications to detect and changes. - View Dependent Claims (17, 18)
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19. Apparatus for detecting changes in an object comprising:
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first means including parallel opaque spaced apart stripes for filtering portions of light reflected by said object and for transmitting the remaining portions of said light; a light sensitive target for receiving said light at a first time t1, said light illuminating a first series of parallel spaced apart regions of said target; means for shifting said remaining portions of said light at a second time t2, said light illuminating a second series of parallel spaced apart regions of said target each of which corresponds to and is interleaved between ones of said first series of regions; and means for comparing corresponding ones of said first and second regions to detect said changes.
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20. A method of detecting intensity changes between a first and a second time, at selected spatial locations of an object, comprising the steps of:
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(1) focusing a real image of said object on a grating having alternate clear and opaque lines formed thereon, whereby light from said selected spatial locations passes through said clear lines; (2) focusing said light passing through said clear lines on respective first regions of a light sensitive target at said first time and on respective second regions of said target at said second time; and (3) comparing the light focused on the first and second target regions associated with at least one of said selected spatial locations to detect said changes. - View Dependent Claims (21)
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Specification