Battery free light emitting diode reflective dot gunsight

Abstract

A reflective dot gunsight is disclosed that includes a power generation unit utilizing a hand driven dynamo to provide power. This enables the gunsight to operate independently of the availability of suitable charged batteries, providing a critical advantage in sporting and combat situations. Failure of battery power at a critical moment is a major source of anxiety and forces many users away from the obvious advantages of lighted reflective dot sights. Battery failure can occur suddenly and without warning rendering the reflective dot sight useless. Even if spare batteries are carried, it takes several minutes to replace the battery. The LED lamp in the disclosed gunsight is powered by a non-removable supercapacitor that is charged by a hand cranked dynamo. A few seconds of cranking provides minutes of operation and the device can be recharged to full capacity at any time.

What is claimed is: 
     
         1 . A reflective dot gunsight, comprising:
 a housing;   a light source;   an objective lens and an eye lens, each of which is disposed within said housing and adapted to reflect light from said light source to an eye of a user;   wherein said objective lens is also disposed within said housing and adapted to reveal a target within a field of view of the gunsight;   a source of power coupled to power said light source; and   a power generator coupled to said power source.   
     
     
         2 . The reflective dot gunsight according to  claim 1 , wherein said light source comprises a light emitting diode (LED). 
     
     
         3 . The reflective dot gunsight according to  claim 2 , wherein said LED is adapted to project a dot which is viewable by said user. 
     
     
         4 . The reflective dot gunsight according to  claim 3 , wherein said projected dot is in the same focal plane as said target. 
     
     
         5 . The reflective dot gunsight according to  claim 1 , wherein said objective lens comprises a partially reflective lens. 
     
     
         6 . The reflective dot gunsight according to  claim 1 , wherein said eye lens comprises a partially reflective lens. 
     
     
         7 . The reflective dot gunsight according to  claim 1 , wherein said source of power comprises a supercapacitor. 
     
     
         8 . The reflective dot gunsight according to  claim 7 , wherein said supercapacitor comprises a single-cell supercapacitor. 
     
     
         9 . The reflective dot gunsight according to  claim 1 , wherein said power generator comprises:
 a hand crank;   a DC motor adapted to be used as a generator; and   a gear train between said hand crank and said DC motor, said gear train adapted to raise the rotational speed of said DC motor.   
     
     
         10 . The reflective dot gunsight according to  claim 9 , wherein said source of power comprises a single-cell supercapacitor. 
     
     
         11 . The reflective dot gunsight according to  claim 10 , wherein said DC motor is adapted to charge said supercapacitor. 
     
     
         12 . The reflective dot gunsight according to  claim 11 , further comprising a diode between said supercapacitor and said DC motor. 
     
     
         13 . The reflective dot gunsight according to  claim 11 , further comprising a boost and regulation circuit between said supercapacitor and said light source in order to maintain a constant current to said light source.