Compact light source for fiber optics illumination

• US 5,341,275 A
• Filed: 01/22/1992
• Issued: 08/23/1994
• Est. Priority Date: 01/22/1992
• Status: Expired due to Fees

• Current Assignee: Abbas Ghandehari
• Original Assignee: Abbas Ghandehari
• Inventors: Ghandehari, Abbas
• Primary Examiner(s): Cole, Richard R.
• Assistant Examiner(s): Cariaso, Alan B.
• Application Number:
  US07/823,667
• Time in Patent Office: 944 Days
• Field of Search: 362/32, 362/294, 362/373, 362/293, 385/31, 385/27, 385/33, 385/39, 359/385
• US Class Current: 362/580
• CPC Class Codes: F21V 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/76 with essentially identical parallel planar fins or blades, e.g. with comb-like cross-section
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G02B 6/4296 coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers

Abstract

An apparatus is provided for illuminating a fiber optic cable. A light source projects an illuminating light beam through a cold mirror placed at approximately a 45° angle to the direction of the light beam, whereby a visible component of the light beam is reflected in a direction normal to the light beam while a heat component of the light beam is passed through the cold mirror. A heat sink absorbs the heat component of the light beam. A ventilation duct at the heat sink is also included to conduct convective heat away from the apparatus. A plano-convex lens focuses the light beam at a focal point in space. A conduit support is included to support the fiber optic cable in a position incident to the light beam. The support has a cone-shaped aperture positioned coaxially with a diverging cone of the light beam from the focal point, and receives the diverging cone therein such that the conduit, coaxially inserted into the cone-shaped aperture, accommodates the total diverging cone of the light beam thereon. A heat shield is positioned in the path of the light beam, the shield having an aperture for passing the light beam therethrough while absorbing heat therein. A variable bandpass filter is positioned at the focal point of the light beam for passing a specific color of light therethrough, and includes a plurality of discrete filter elements and a motor for positioning any of the elements in the path of the light beam. A variable density filter is positioned in the path of the light beam for controlling the amount of light passing therethrough to the conduit.

Claims

1. An illumination apparatus, comprising:

a light source for projecting an illuminating light beam, the light beam having broadband energy components including a heat component;

means for rejecting the heat component of the light beam;

means for focusing the light beam so that the beam passes through a point in space forming a diverging cone therefrom;

a conduit to receive the diverging cone for conducting the light beam;

means for supporting the conduit in a position incident to the light beam, the support means having a cone-shaped aperture, the aperture positioned coaxially with the diverging cone of the light beam such that the cone of the light beam is coincident with the cone-shaped aperture in direct congruence such that the conduit, coaxially inserted into the cone-shaped aperture, receives the total diverging cone of the light beam thereon.

2. The apparatus of claim 1 further including a heat shield positioned in the path of the light beam, between the focusing means and the conduit, the shield having an aperture for passing the light beam, the shield preventing stray and scattered light and heat from passing to the conduit.

3. The apparatus of claim 2 further including variable bandpass filter means positioned in the path of the light beam between the heat shield and the aperture for passing a single color of choice.

4. The apparatus of claim 3 further including heat rejection means coated on the filter in order to reflect incident heat.

5. The apparatus of claim 3 wherein the filter means includes a plurality of discrete filter elements, and further including a drive means for positioning any one of the elements in the path of the light beam.

6. The apparatus of claim 5 wherein each of the discrete filter elements are positionable at the focal point of the light beam, whereby the elements may be made arbitrarily small, yet provide efficient filtering of the light beam.

7. The apparatus of claim 1 further including a heat sink for absorbing, the heat component of the light beam and other heat generated by the light source, for natural convective cooling thereof.

8. An illumination apparatus, comprising:

a light source for projecting an illuminating light beam, the light beam having broadband energy components including a heat component;

a cold mirror for rejecting the heat component of the light beam, the cold mirror placed at an angle of 45 degrees to the direction of the light beam so that the visible components are reflected in a direction normal to the light beam while the heat component is passed through the cold mirror to be absorbed;

means for focussing the light beam so that the beam passes through a point in space and presents a diverging cone therefrom, the focusing means being a plano-convex lens;

a heat shield positioned in the path of the light beam, the shield having an aperture for passing the light beam;

a variable bandpass filter means positioned in the path of the light beam for passing a single color of choice;

a conduit to receive the diverging cone for conducting the light beam;

means for supporting the conduit in a position incident to the light beam, the support means having a cone-shaped aperture, the aperture positioned coaxially with the diverging cone of the light beam such that the cone of the light beam is coincident with the cone-shaped aperture in direct congruence such that the conduit, coaxially inserted into the cone-shaped aperture, receives the total diverging cone of the light beam thereon;

a heat sink for absorbing, the heat component of the light beam and other heat generated by the light source, the heat sink having vertical fins for natural upward convective cooling thereof.

9. An illumination apparatus, comprising:

a light source for projecting an illuminating light beam, the light beam having broadband energy components including a heat component;

a cold mirror for rejecting the heat component of the light beam, the cold mirror placed at an angle of 45 degrees to the direction of the light beam so that the visible components are reflected in a direction normal to the light beam while the heat component is passed through the cold mirror to be absorbed;

means for focussing the light beam so that the beam passes through a point in space and presents a diverging cone therefrom, the focusing means being a plano-convex lens;

a heat shield positioned in the path of the light beam, the shield having an aperture for passing the light beam;

a variable bandpass filter means positioned in the path of the light beam for passing a single color of choice;

a conduit to receive the diverging cone for conducting the light beam;

means for supporting the conduit in a position incident to the light beam, the support means having a cone-shaped aperture, the aperture positioned coaxially with the diverging cone of the light beam such that the cone of the light beam is coincident with the cone-shaped aperture in direct congruence such that the conduit, coaxially inserted into the cone-shaped aperture, receives the total diverging cone of the light beam thereon;

a heat sink for absorbing, the heat component of the light beam and other heat generated by the light source, the heat sink having vertical fins for natural upward convective cooling thereof;

at least one ventilation duct placed so as to conduct convective heat away from the apparatus.