Arrow detection system employing a sweeping laser beam

Claim 2

In a system for detecting the position of a projectile in either of two adjacent paths; a pair of reflectors disposed at opposite sides of the adjacent paths; an optical system between the paths including a light source, a rotatable mirror in the path of light emanating from the source disposed to sweep a beam of light across the projectile paths along the reflectors, and means for rotating the mirror; a pair of start photocells, one adjacent each of a respective one of said reflectors in the path of the sweep of the light beam and responsive to the passage of the beam to denote the beginning of the sweep across the projectile path; a mirror between the light source and the rotatable mirror constructed for passing light from the source to the rotatable mirror and having a reflective surface for receiving light from the rotatable mirror reflected from either of said reflectors; and an interrupt photocell disposed to receive light from the inclined mirror and responsive to the interruption of reflected light and the passage of a projectile along either of said paths to denote the angular position of the projectile relative to the photocell adjacent the reflector.

Claim 3

A combination as defined in claim 1 including a condensing lens between the inclined mirror and the interrupt photocell for concentrating reflected light on the interrupt photocell.

Claim 4

A combination as defined in claim 1 wherein the inclined mirror is totally reflective and has a central aperture for passing light from the source to the rotatable mirror.

Claim 5

A combination as defined in claim 3 wherein the light source is a laser unit for directing a laser beam through the aperture in the inclined mirror.

Claim 6

The combination as defined in claim 1 wherein each of said reflectors comprises a strip of material adapted to reflect substantially all light back toward the source throughout a wide range of angles of incidence at which the light strikes strip.

Claim 7

In a system for detecting the position of a projectile in either of a pair of adjacent paths and an associated penetrable target, a pair of adjacent reflective strips along one side of each path adjacent the corresponding target, adapted to reflect light back in the direction from which it comes, a single light source, a pair of optical systems interposed between the paths, one associated with each reflective strip associated with each path and spaced about said light source, and each including a rotatable mirror in the path of light emanating from the source and disposed to sweep a beam of light across the projectile paths and along the associated reflective strips, a start photocell at one end of each reflective strip in the path of the sweep of the associated light beam responsive to the beam to denote the beginning of the sweep of the beam, an inclined mirror between said light source and the associated rotatable mirror constructed to pass light from the source to the rotatable mirror and having a reflective surface for receiving light from the rotatable mirror reflected from the reflective strips, and a stop photocell associated with each inclined mirror to receive light therefrom and responsive to change in reflected light on passage of a projectile along either path to denote the angular position of the projectile relative to the associated start photocell.

Claim 8

In a system for detecting the position of a projectile in either of a pair of adjacent paths and an associated penetrable target, a pair of adjacent reflective strips along one side of each path adjacent the corresponding target, adapted to reflect light back in the direction from which it comes, a single light source, a pair of optical systems interposed between the paths, one associated with each reflective strip associated with each path and spaced about said light source, and each including a rotatable mirror in the path of light emanating from the source and disposed to sweep a beam of light across the projectile paths and along the associated reflective strips, a start photocell at one end of each reflective strip in the path of the sweep of the associated light beam responsive to the beam to denote the beginning of the sweep of the beam, an inclined mirror between said light source and the associated rotatable mirror constructed to pass light from the source to the rotatable mirror and having a reflective surface for receiving light from the rotatable mirror reflected from the reflective strips, and a stop photocell associated with each inclined mirror to receive light therefrom and responsive to change in reflected light on passage of a projectile along either path to denote the angular position of the projectile relative to the associated start photocell.

Claim 9

A combination as defined in claim 6 wherein each inclined mirror is totally reflective and has an aperture for passing light from the light source to the associated rotatable mirror.

Claim 10

A combination as defined in claim 2 wherein the light source comprises a laser unit for directing laser beams out opposite ends thereof in opposite directions through the associated apertures toward the rotating mirrors.

Claim 11

In an apparatus for detecting the locations of arrows passing through a pair of adjacent penetrable targets, an optical housing disposed between the targets, a source of A highly collimated beam of light in the housing, a rotatable mirror in the housing disposed to sweep a beam of light from the source across each target as the mirror rotates, a reflective strip alongside each target opposed to the optical housing for receiving light swept across the target and reflecting the light back toward the rotatable mirror, a start photocell adjacent one end of each strip in the path of the light to denote the beginning of the sweep along each strip, an inclined mirror between the light source and the rotatable mirror for passing light from the source to the rotatable mirror and having a reflective surface to reflect light from the rotatable mirror reflected from each strip, and a stop photocell disposed to receive light from the inclined mirror and responsive to the change in light on passage of an arrow to denote the angular position of the arrow relative to the start photocell.

Claim 12

In an apparatus for detecting the locations of arrows passing through a pair of adjacent penetrable targets, an optical housing disposed between the targets, a source of A highly collimated beam of light in the housing, a rotatable mirror in the housing disposed to sweep a beam of light from the source across each target as the mirror rotates, a reflective strip alongside each target opposed to the optical housing for receiving light swept across the target and reflecting the light back toward the rotatable mirror, a start photocell adjacent one end of each strip in the path of the light to denote the beginning of the sweep along each strip, an inclined mirror between the light source and the rotatable mirror for passing light from the source to the rotatable mirror and having a reflective surface to reflect light from the rotatable mirror reflected from each strip, and a stop photocell disposed to receive light from the inclined mirror and responsive to the change in light on passage of an arrow to denote the angular position of the arrow relative to the start photocell.

Claim 13

In an apparatus for detecting the locations of arrows passing through a pair of adjacent penetrable targets, an optical housing disposed between the targets, a source of light in the housing, a rotatable mirror in the housing disposed to sweep a beam of light from the source across each target as the mirror rotates, a reflective strip alongside each target opposed to the optical housing for receiving light swept across the target and reflecting the light back toward the rotatable mirror, a start photocell adjacent one end of each strip in the path of the light to denote the beginning of the sweep along each strip, an inclined mirror between the light source and the rotatable mirror for passing light from the source to the rotatable mirror and having a reflected surface to reflect light from the rotatable mirror reflected from each strip, a stop photocell disposed to receive light from the inclined mirror and responsive to the change in light on passage of an arrow to denote the angular position of the arrow relative to the start photocell, a second source of light in the housing, a second rotatable mirror in the housing disposed to sweep a beam of light from the second source across each target on rotation, a second reflective strip alongside each target adjacent the first recited strip for receiving light from the second source and reflecting the light back to the second rotatable mirror, a start photocell adjacent one end of each second reflective strip in the path of light from the second source to denote the beginning of the sweep along the strip, an inclined mirror between the second light source and the second rotatable mirror for passing light from the source to the rotatable mirror and having a reflective surface to reflect light from the rotatable mirror reflected from each second strip, and a second stop photocell disposed to receive light from the second inclined mirror and responsive to change in light on passage of an arrow to denote the angular position of the arrow relative to the start photocell.

Claim 14

In an apparatus for detecting the locations of arrows passing through a pair of adjacent penetrable targets, an optical housing disposed between the targets, a source of light in the housing, a rotatable mirror in the housing disposed to sweep a beam of light from the source across each target as the mirror rotates, a reflective strip alongside each target opposed to the optical housing for receiving light swept across the target and reflecting the light back toward the rotatable mirror, a start photocell adjacent one end of each strip in the path of the light to denote the beginning of the sweep along each strip, an inclined mirror between the light source and the rotatable mirror for passing light from the source to the rotatable mirror and having a reflected surface to reflect light from the rotatable mirror reflected from each strip, a stop photocell disposed to receive light from the inclined mirror and responsive to the change in light on passage of an arrow to denote the angular position of the arrow relative to the start photocell, a second source of light in the housing, a second rotatable mirror in the housing disposed to sweep a beam of light from the second source across each target on rotation, a second reflective strip alongside each target adjacent the first recited strip for receiving light from the second source and reflecting the light back to the second rotatable mirror, a start photocell adjacent one end of each second reflective strip in the path of light from the second source to denote the beginning of the sweep along the strip, an inclined mirror between the second light source and the second rotatable mirror for passing light from the source to the rotatable mirror and having a reflective surface to reflect light from the rotatable mirror reflected from each second strip, and a second stop photocell disposed to receive light from the second inclined mirror and responsive to change in light on passage of an arrow to denote the angular position of the arrow relative to the start photocell.

Claim 15

A combination as defined in claim 5, wherein the rotatable mirrors each have two reflective surfaces to sweep two successive beams of light on each revolution.

Claim 16

A combination as defined in claim 5, wherein the rotatable mirrors are disposed to sweep their beams in planes intersecting each other in the optical housing so that each mirror scans a forwardly disposed strip adjacent one target and a rearwardly disposed strip adjacent the other target.

Claim 17

A combination as defined in claim 7, wherein said light sources comprise a laser unit for directing laser beams coaxially out opposite ends thereof toward the rotatable mirrors.