Projection unit including glass reflector with insulative cap member

• US 4,482,942 A
• Filed: 06/04/1984
• Issued: 11/13/1984
• Est. Priority Date: 03/30/1981
• Status: Expired due to Fees

• Current Assignee: GTE Products Corporation
• Original Assignee: GTE Products Corporation
• Inventors: Hough, Harold L., Blaisdell, Ronald G., Martenson, Richard B.
• Primary Examiner(s): Nelson, Peter A.
• Application Number:
  US06/616,797
• Time in Patent Office: 162 Days
• Field of Search: 362/350, 362/368, 362/375, 362/267, 362/296, 362/306, 362/310, 362/347, 362/365, 362/293, 362/307, 353/97, 315/76, 313/112, 313/113, 313/315, 313/317, 313/318
• US Class Current: 362/293
• CPC Class Codes: G03B 21/20 Lamp housings
• CPC Class Codes: G03B 21/2046 Positional adjustment of light sources

Abstract

An improved projection unit including a glass reflector having a forward reflecting portion which includes an internal substantially concave reflecting surface and an apex portion with an opening therein. An incandescent lamp is oriented such that its envelope portion is arranged relative to the reflecting surface of the reflector and its sealed end portion having a pair of spaced apart lead-in wires projecting therefrom is arranged within the reflector'"'"'s opening. An electrically insulative cap member is fixedly secured to an external surface of a glass reflector immediately adjacent the reflector'"'"'s rear opening. The cap member includes a pair of contacts spacedly located therein, each of these contacts being joined electrically to a respective one of the projecting lead-in wires from the incandescent lamp. In a further embodiment of the invention, a holder is provided for providing electrical connection between the projection system'"'"'s circuitry and the incandescent lamp.

Claims

1. A projection unit for being positioned within a holder adapted for being electrically connected to the electrical circuitry associated with a projection system, said projection unit comprising:

a glass reflector having a forward reflecting portion including an internal, substantially concave reflecting surface and an apex portion having an opening therein;

an incandescent lamp including an envelope portion having a filament structure therein and a sealed end portion adjacent said envelope portion and including a pair of spaced-apart lead-in wires projection therefrom, said incandescent lamp positioned within said glass reflector such that said envelope portion of said lamp is located substantially within said forward reflecting portion relative to said concave reflecting surface, and said sealed end portion of said lamp is located substantially within said rear opening within said apex portion; and

a plastic cap member for being positioned within said holder and including an aperture therein, said cap member being fixedly secured to an external surface of said reflecting portion of said glass reflector in an abutting manner immediately adjacent said opening within said apex portion such that said aperture of said plastic cap member is coaxially aligned with the optical axis of said glass reflector to thereby align said plastic cap member in a predetermined manner with said internal substantially concave reflecting surface of said reflector, said sealed end portion of said lamp being centrally disposed within said aperture of said plastic cap member in a fixed manner prior to said fixedly securing of said plastic cap member to said glass reflector and thereby oriented relative to the surfaces of said cap member which abut said glass reflector and also to said internal, substantially concave reflecting surface of said glass reflector so as to be precisely oriented with respect to said reflector, said cap member including a pair of electrical contacts spacedly located therein, each of said electrical contacts electrically connected to a respective one of said lead-in wires projecting from said sealed end portion of said incandescent lamp, said reflecting surface of said glass reflector including a dichroic coating thereon which enables infrared radiation to pass therethrough while reflecting visible light whereby heat from said lamp will pass through said reflecting portion of said reflector.

2. The projection unit according to claim 1 wherein said internal, substantially concave reflecting surface of said glass reflector is substantially ellipsoidal in configuration.

3. The projection unit according to claim 1 wherein said plastic material of said cap member is polyphenylene sulfide.

4. The projection unit according to claim 1 wherein said electrical contacts are spacedly positioned within said cap member on opposite sides thereof, said cap member further including a pair of slots located therein, each of said slots located within a respective one of said opposite sides adjacent a respective one of said electrical contacts, each of said lead-in wires projecting from said sealed end portion of said lamp being connected to said respective one of said contacts through one of said slots.

5. The projection unit according to claim 1 wherein said holder member includes a pair of spaced-apart contacts, each of said contacts electrically engaging a respective one of said contacts located within said cap member when said cap member is positioned within said holder member.

6. The projection unit according to claim 5 wherein said holder member includes an upstanding, substantially planar faceplate portion defining a channel therein and said glass reflector includes a substantially planar forward rim portion, said rim portion being slidably located within said channel when said cap member is positioned within said holder member.

7. The projection unit according to claim 6 wherein each of said contacts within said holder exerts a biasing force against each respective one of said contacts within said cap member when said cap member is positioned within said holder member, said force in turn biasing said rim portion of said glass reflector against said faceplate portion of said holder member.

8. The projection unit according to claim 5 wherein said holder member includes a rear upstanding portion defining a receiving slot therein, said insulative cap member further including means thereon for aligning said cap member within said receiving slot.

9. The projection unit according to claim 8 wherein said aligning means comprises at least one thin, elongated fin, said fin being inserted within said receiving slot when said cap member is positioned within said holder member.

10. The projection unit according to claim 9 wherein the number of said fins is two, each of said fins extending from said cap member on opposing sides thereof.

11. The projection unit according to claim 1 wherein said internal substantially concave reflecting surface of said glass reflector is substantially parabolic in configuration.

12. The projection unit according to claim 1 wherein said plastic cap member includes a pair of semi-circular grooves within the surface thereof which abuts said glass reflector, said fixed securement of said plastic cap member to said glass reflector being accomplished using a quantity of sealing cement located substantially within said grooves.

13. A projection unit for being positioned within a holder adapted for being electrically connected to the electrical circuitry associated with a projection system, said projection unit comprising:

a glass reflector having a forward reflecting portion including an internal, substantially concave reflecting surface and an extending neck portion having an opening therein;

an incandescent lamp including an envelope portion having a filament structure therein and a sealed end portion adjacent said envelope portion and including a pair of spaced-apart lead-in wires projecting therefrom, said incandescent lamp positioned within said glass reflector such that said envelope portion of said lamp is located substantially within said forward reflecting portion relative to said concave reflecting surface, and said sealed end portion of said lamp is located substantially within said opening within said extending neck portion;

a plastic cap member for being positioned within said holder and including an aperture therein, said plastic cap member being fixedly secured to an external surface of said reflecting portion of said glass reflector in an abutting manner immediately adjacent said opening within said extending neck portion such that said aperture of said plastic cap member is coaxially aligned with the optical axis of said glass reflector to thereby align said plastic cap member in a predetermined manner with said internal, substantially concave reflecting surface of said reflector, said sealed end portion of said lamp being centrally disposed within said opening within said extending neck portion of said reflector in a fixed manner prior to said fixedly securing of said plastic cap member to said reflecting portion of said glass reflector such that said lamp will be oriented relative to said external surface of said reflector, said plastic cap member thereby being precisely oriented with respect to both said reflector and said lamp during said fixedly securing of said cap member to said reflector, said cap member including a pair of electrical contacts spacedly located therein, each of said electrical contacts electrically connected to a respective one of said lead-in wires projecting from said sealed end portion of said incandescent lamp, said reflecting surface of said glass reflector including a dichroic coating thereon which enables infrared radiation to pass therethrough while reflecting visible light whereby heat from said lamp will pass through said reflecting portion of said reflector.

14. The projection unit according to claim 13 wherein said external surface of said glass reflector having said insulative cap member secured thereto is substantially flat, said surface oriented at a predetermined angle with respect to said optical axis of said reflector.

15. The projection unit according to claim 14 wherein said predetermined angle is within the range of from about 50 degrees to about 70 degrees.

16. The projection unit according to claim 14 wherein the surface of said plastic cap member which abuts said external surface of said glass reflector is also flat to thereby assure both positive engagement and alignment between said cap and reflector members during said fixed securement.

17. The projection unit according to claim 16 wherein said cap member is secured to said external surface of said glass reflector using a sealing cement, said flat surface of said cap member including a pair of semi-circular grooves located therein, said sealing cement located within said grooves.

18. The projection unit according to claim 13 wherein said extending neck portion of said reflector includes a pair of protuberance portions thereon and said plastic cap member includes a pair of channels therein, each of said protuberance portions being aligned with and located within a respective one of said channels during said fixed securement of said plastic cap member to said reflector.

19. The projection unit according to claim 13 wherein said internal, substantially concave reflecting surface of said glass reflector is substantially ellipsoidal in configuration.

20. The projection unit according to claim 13 wherein said plastic material of said cap member is polyphenylene sulfide.

21. The projection unit according to claim 13 wherein said electrical contacts are spacedly positioned within said cap member on opposite sides thereof, said cap member further including a pair of slots located therein, each of said slots located within a respective one of said opposite sides adjacent a respective one of said electrical contacts, each of said lead-in wires projecting from said sealed end portion of said lamp being connected to said respective one of said contacts through one of said slots.

22. The projection unit according to claim 13 wherein said holder member includes a pair of spaced-apart contacts, each of said contacts electrically engaging a respective one of said contacts located within said cap member when said cap member is positioned within said holder member.

23. The projection unit according to claim 22 wherein said holder member includes an upstanding, substantially planar faceplate portion defining a channel therein and said glass reflector includes a substantially planar forward rim portion, said rim portion being slidably located within said channel when said cap member is positioned within said holder member.

24. The projection unit according to claim 23 wherein each of said contacts within said holder exerts a biasing force against each respective one of said contacts within said cap member when said cap member is positioned within said holder member, said force in turn biasing said rim portion of said glass reflector against said faceplate portion of said holder member.

25. The projection unit according to claim 22 wherein said holder member includes a rear upstanding portion defining a receiving slot therein, said insulative cap member further including means thereon for aligning said cap member within said receiving slot.

26. The projection unit according to claim 25 wherein said aligning means comprises at least one thin, elongated fin, said fin being inserted within said receiving slot when said cap member is positioned within said holder member.

27. The projection unit according to claim 26 wherein the number of said fins is two, each of said fins extending from said cap member on opposing sides thereof.

28. The projection unit according to claim 13 wherein said internal, substantially concave reflecting surface of said glass reflector is substantially parabolic in configuration.