Optical system for obtaining separate and simultaneous near-infrared and visible light images

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION A quartz-halogen lamp 1 directs light into a light transmissive ring member 3 via fiber-optic bundle 5, which illuminates a given area 7 containing the aforesaid fastener 9.
Laser generator 11 produces an illuminated crosshair fiducial indicia in the near infrared region above 700 nm.
Such a fiducial image may be formed by a suitable mask(s) within the laser stripe generator.
The resulting illuminated crosshair is directed upon the surface of the aircraft component 7 via mirror 13 to perform the aforesaid function.
The area occupied by the crosshair image will be substantially smaller than the given area illuminated by the visible light ring 3.
The visible white light is reflected off of area 7, is reflected off of cold mirror 15 and is directed at the first electronic camera 19 via mirror 17.
The electronic camera is used to control the fastener removal operations.
On the other hand, the laser crosshair image passes through cold mirror 15 rather than being reflected therefrom, and is used by the second electronic camera 21 to perform the 3-D location function mentioned above.
The nature of a cold mirror, enabling it to transmit IR and reflect visible light, is known in the art.
See for example, page 311 of "Optics", Hecht/Zajak, Addison-Wesley, 1974.
A short-pass filter 23 is provided at the exit aperture of the quartz-halogen lamp 1 for blocking the transmission of near IR radiation above 700 nm.
Without this filter a considerable amount of full field illumination would pass through the cold mirror, defeating its purpose.
It should now be appreciated that the invention provides apparatus for simultaneously obtaining images of a laser pattern in the IR, and white light images of a floodlit view of a given area by employing a wavelength responsive optical component such as a cold mirror, in the optical paths of the first and second electronic cameras.
Since variations in the aforesaid apparatus will be apparent to the worker in the art, the scope of the invention is to be limited only by the terms of the following claims and art recognized equivalents thereof