Patent ID: 6909499

Claim:
A light source for an optical viewing device, said light source comprising: a lamp ( 1 ); at least one light sensor ( 3 a, 3 b ) for measuring an intensity of light delivered by said lamp ( 1 ) and generating an intensity signal representative of said measured light intensity; an electronic unit ( 4 ) connected to said at least one light sensor ( 3 a, 3 b ) for comparing said intensity signal to a predefined light reduction threshold value; and indicating means connected to said electronic unit ( 4 ) for providing an indication to a user ( 9 ) if said intensity signal is below said predefined light reduction threshold value, wherein said indicating means comprises an indication unit ( 12 ) on said optical viewing device, wherein said indication unit ( 12 ) provides a visible indication arranged to be reflected directly into an intermediate image of said optical viewing device ( 7 ) by a reflecting-in unit ( 8 ) of said optical viewing device ( 7 ).