Method and apparatus to locate lost golf balls

Abstract

A method is disclosed that assists a golf player in finding golf balls that have been lost. The method relies on the presence of materials in the golf ball that emit light at a second wavelength when illuminated by light at a first wavelength. Implementations of such a ball-finding device are disclosed that use blue or near-UV illumination light to create emission at somewhat longer wavelengths. Unlike prior art that uses UV illumination, the disclosed devices do not require proximity to the ball to enhance visual detection of the same.

1 . An apparatus for detecting an object, the apparatus comprising: 
 a light source adapted to emit a beam of light at wavelengths absorbed by the object or a coating thereon;    a detector adapted to detect light at wavelengths fluoresced by the object or coating thereon;    a processor adapted to determine the presence of an object from the light detected by the detector; and    on oscillator to modulate the light source;    wherein the processor includes a mixer, which receives the modulation signal from the oscillator, and a signal from the detector.    
   
   
       2 . The apparatus as claimed in  claim 1 , further including a driver circuit.  
   
   
       3 . The apparatus as claimed in  claim 2 , wherein the processor further includes a low-pass filter which is adapted to pass signals of a significant magnitude if a coherent signal averaged over time is present.  
   
   
       4 . The apparatus as claimed in  claim 3 , wherein the processor further includes a threshold detector, which compares the signal from the low-pass filter with a predetermined threshold, and sends a signal to an indicator if the signal exceeds the threshold, to indicate the presence of a ball.  
   
   
       5 . The apparatus as claimed in  claim 1 , wherein the modulation will be in the frequency range 10 Hz to 100 MHz.  
   
   
       6 . A method for locating lost objects, the objects having a coating which absorbs light at one wavelength, and fluoresces at a second wavelength; the method consisting in the steps of: 
 providing a bead of light having a wavelength absorbed by the coating on the object;    detecting light of wavelengths fluoresced by the object to be located; and    determining from the light detected the presence or otherwise of the object.    
   
   
       7 . The apparatus as claimed in  claim 1 , wherein the processor further includes a low-pass filter which is adapted to pass signals of a significant magnitude if a coherent signal averaged over time is present.  
   
   
       8 . The apparatus as claimed in  claim 7 , wherein the processor further includes a threshold detector, which compares the signal from the low-pass filter with a predetermined threshold, and sends a signal to an indicator if the signal exceeds the threshold, to indicate the presence of a ball.