Transmission line presence sensor

Claim 2

In combination: passageway surface means having a principal direction of passage, dielectric substrate means having surface means substantially coplanar with said passageway surface means, signal generator means for supplying pulse signals, transmission line energy coupling means excited by said pulse signals comprising first and second transmission line conductor means of finite length spaced apart in substantially parallel relation on said substrate surface means and lying substantially transverse of said principal direction, said coupling means having a predetermined coupling characteristic alterable according to the proximity of an object overlying at least a portion of said coupling means, receiver means for receiving presence detection signals propagating on said second conductor means, utilization means, and gating means for passing said received presence detection signals to said utilization means while rejecting spurious signals arising adjacent the ends of said conductors of finite length.

Claim 3

Variable transmission line energy coupling object presence detector means having a predetermined energy coupling characteristic comprising: dielectric substrate means having surface means adapted to be placed in substantially coplanar relation with passageway surface means, first and second substantially parallel planar transmission line conductor means at said dielectric surface means, said substrate means and said conductor means being so constructed and arranged as to respond to said object when overlying at least a portion of said coupling means by a change in the degree of energy coupling between said conductor means, and means responsive to said change.

Claim 4

Variable transmission line energy coupling object presence detector means having a predetermined energy coupling characteristic comprising: dielectric substrate means having surface means adapted to be placed in substantially coplanar relation with passageway surface means, first and second substantially parallel planar transmission line conductor means at said dielectric surface means, said substrate means and said conductor means being so constructed and arranged as to respond to said object when overlying at least a portion of said coupling means by a change in the degree of energy coupling between said conductor means, and means responsive to said change.

Claim 5

Apparatus as described in claim 2 wherein said dielectric substrate means is adapted to be placed on said passageway surface means.

Claim 6

Apparatus as described in claim 2 wherein said dielectric substrate means is placed within a recess in said passageway surface means.

Claim 7

Variable transmission line energy-coupling object-weight-detection means having a predetermined energy coupling characteristic comprising: dielectric substrate means having surface means, first and second substantially parallel planar transmission line conductor means at said dielectric surface means, flexible dielectric sheet means overlying said conductor means, platform means overlying said dielectric sheet means, said platform means having contact means for contacting said flexible sheet means, pulse generator means for exciting said first conductor means, receiver means responsive to signals coupled to said second conductor means in the presence of said object, and utilization means responsive to said receiver means.

Claim 8

Variable transmission line energy-coupling object-weight-detection means having a predetermined energy coupling characteristic comprising: dielectric substrate means having surface means, first and second substantially parallel planar transmission line conductor means at said dielectric surface means, flexible dielectric sheet means overlying said conductor means, platform means overlying said dielectric sheet means, said platform means having contact means for contacting said flexible sheet means, pulse generator means for exciting said first conductor means, receiver means responsive to signals coupled to said second conductor means in the presence of said object, and utilization means responsive to said receiver means.

Claim 9

Variable transmission line energy coupling object presence detector means having a predetermined energy coupling characteristic comprising: dielectric substrate means having surface means adapted to be placed in substantially coplanar relation with passageway surface means, first and second substantially parallel planar transmission line conductor means at said dielectric surface means. said substrate means and said conductor means being so constructed and arranged as to respond to said object when overlying at least a portion of said coupling means by a change in the degree of energy coupling between said conductor means, means responsive to said change, flexible layer means underlying said conductor means within said dielectric means, and dielectric sheet means overlying said conductor means, said flexible layer means being adapted to be reversibly compressed for permitting reversible variation of the amount of dielectric material oF said dielectric substrate lying between said conductor means.

Claim 10

Variable transmission line energy coupling object presence detector means having a predetermined energy coupling characteristic comprising: dielectric substrate means having surface means adapted to be placed in substantially coplanar relation with passageway surface means, first and second substantially parallel planar transmission line conductor means at said dielectric surface means. said substrate means and said conductor means being so constructed and arranged as to respond to said object when overlying at least a portion of said coupling means by a change in the degree of energy coupling between said conductor means, means responsive to said change, flexible layer means underlying said conductor means within said dielectric means, and dielectric sheet means overlying said conductor means, said flexible layer means being adapted to be reversibly compressed for permitting reversible variation of the amount of dielectric material oF said dielectric substrate lying between said conductor means.

Claim 11

Variable transmission line energy coupling object presence detector means having a predetermined energy coupling characteristic comprising: dielectric substrate means having surface means adapted to be placed in substantially coplanar relation with passageway surface means, first and second substantially parallel planar transmission line conductor means at said dielectric surface means, said substrate means surface means including a recessed portion between said conductor means, flexible dielectric sheet means overlying said conductor means, said flexible sheet means being adapted to be reversibly flexed into said recessed portion of said surface means, said substrate means and said conductor means being so constructed and arranged as to respond to said object when overlying at least a portion of said coupling means by a change in the degree of energy coupling between said conductor means, and means responsive to said change.

Claim 12

Variable transmission line energy coupling object presence detector means having a predetermined energy coupling characteristic comprising: dielectric substrate means having surface means adapted to be placed in substantially coplanar relation with passageway surface means, first and second substantially parallel planar transmission line conductor means at said dielectric surface means, said substrate means surface means including a recessed portion between said conductor means, flexible dielectric sheet means overlying said conductor means, said flexible sheet means being adapted to be reversibly flexed into said recessed portion of said surface means, said substrate means and said conductor means being so constructed and arranged as to respond to said object when overlying at least a portion of said coupling means by a change in the degree of energy coupling between said conductor means, and means responsive to said change.

Claim 13

Presence detector means for detecting the presence of an object comprising: first and second transmission lines having a common directionally coupling region for coupling high frequency signals from said first to said second transmission line in the presence of said object, said first transmission line having input port means and first absorber means at opposite ends of said directionally coupling region, said second transmission line having output port means and second absorber means at opposite ends of said directionally coupling region, signal generator means for supplying high frequency signals at said input port means, receiver means for receiving presence detection signals at said output port means, utilization means, and gating means responsive to said signal generator means for passing said received presence detection signals to said utilization means while rejecting spurious signals caused by any impedance mismatch at said input port means, said output port means, or said first or second absorber means.

Claim 14

Presence detector means for detecting the presence of an object comprising: first and second transmission lines having a common directionally coupling region for coupling high frequency signals from said first to said second transmission line in the presence of said object, said first transmission line having input port means and first absorber means at opposite ends of said directionally coupling region, said second transmission line having output port means and second absorber means at opposite ends of said directionally coupling region, signal generator means for supplying high frequency signals at said input port means, receiver means for receiving presence detection signals at said output port means, utilization means, and gating means responsive to said signal generator means for passing said received presence detection signals to said utilization means while rejecting spurious signals caused by any impedance mismatch at said input port means, said output port means, or said first or second absorber means.

Claim 15

Apparatus as described in claim 8 further including: dielectric substrate means having a substantially planar surface, said first and second transmission lines being affixed to said planar surface.

Claim 16

Apparatus as described in claim 9 wherein said planar surface of said dielectric substrate means lies substantially in the plane of passageway surface means for forming a substantially coplanar extension of said passageway surface means.

Claim 17

Apparatus as described in claim 8 wherein said signal generator means comprises pulse generator means.

Claim 18

Apparatus as described in claim 11 wherein said pulse generator means is adapted to generate a train of base-band subnanosecond electromagnetic pulses.

Claim 19

Apparatus as described in claim 11 wherein said receiver means is adapted to respond to pulse signals.

Claim 20

Apparatus as described in claim 13 wherein said receiver means is adapted to respond to the receipt of base-band subnanosecond electromagnetic pulses.

Claim 21

Apparatus as described in claim 10 wherein said gating means is operated in synchronism with said pulse generator means.

Claim 22

Apparatus as described in claim 8 wherein said utilization means comprises alarm means.

Claim 23

Apparatus as described in claim 8 wherein said utilization means includes visual display means.

Claim 24

Apparatus as described in claim 8 wherein said utilization means includes control means adapted to control controllable means.