Stage lighting fixture
A stage lighting fixture having: a casing having a closed first end and an open second end; 5 a light source housed inside the casing, close to the first end, and which emits a light beam along an optical axis; an optical assembly positioned to intercept the light beam, and having a focal point located between the light source and the optical assembly; and a reflector coupled to the light source; the reflector and the light source being designed and coupled to concentrate the light beam substantially at a work point substantially coincident with the focal point of the optical assembly; and the light source being defined by a short-arc lamp to project a light bar.
1. A stage lighting fixture for projecting a light bar comprising:
a casing having a first end and a second end;
a short-arc lamp, which is housed inside the casing ( 2 ), close to the first end ( 9 ), and emits a light beam;
a reflector ( 4 ), which is coupled to the short-arc lamp to direct the light beam along an optical axis; is shaped and spaced apart from the short-arc map to concentrate the light beam substantially at a work point (P L ) located along the optical axis; and
an output optical assembly ( 5 ), which is located at the second end of the casing, is configured to have a focal point (P F ) located along the optical axis, and is spaced apart from the short-arc lamp so that the focal point coincides with the work point.
2. A lighting fixture as claimed in claim 1 , wherein the short-arc lamp ( 3 ) comprises a bulb ( 11 ) containing two electrodes ( 12 ) connected to a power circuit ( 13 ) and spaced a first distance (D 1 ) apart.
3. A lighting fixture as claimed in claim 2 , wherein the first distance (D 1 ) between the electrodes ( 12 ) is less than roughly 2 mm.
4. A lighting fixture as claimed in claim 2 , wherein the first distance (D 1 ) between the electrodes ( 12 ) is roughly 1 mm.
5. A lighting fixture as claimed in claim 1 , wherein the reflector ( 4 ) has an outer edge ( 14 ); the work point (P L ) being located a second distance (D 2 ) from the outer edge ( 14 ) of the reflector ( 4 ).
6. A lighting fixture as claimed in claim 5 , wherein the second distance (D 2 ) is roughly 34.5 mm.
7. A lighting fixture as claimed in claim 1 , and comprising processing means ( 7 ) for processing the light beam; the processing means ( 7 ) being located between the light source ( 3 ) and the optical assembly ( 5 ).
8. A lighting fixture as claimed in claim 7 , wherein the processing means ( 7 ) comprise one or more light beam processing elements ( 18 ); at least one light beam processing element ( 18 ) being located substantially at the work point (P L ).
9. A lighting fixture as claimed in claim 7 , wherein the light beam processing elements ( 18 ) comprise at least a diffuser glass ( 22 ).
10. A lighting fixture as claimed in claim 7 , wherein the light beam processing elements ( 18 ) comprise at least a color assembly ( 20 ).
11. A lighting fixture as claimed in claim 7 , wherein the light beam processing elements ( 18 ) comprise at least a prismatic lens ( 23 ).
12. A lighting fixture as claimed in claim 7 , wherein the light beam processing elements ( 18 ) comprise at least a gobo assembly ( 21 ).
13. A lighting fixture as claimed in claim 12 , wherein the gobo assembly ( 21 ) comprises at least one disk ( 26 ) having a number of gobos ( 27 ) for intercepting the light beam; the gobo assembly ( 21 ) being positioned so that the gobo ( 27 ) in use is located substantially at the work point (P L ).
14. A lighting fixture as claimed in claim 1 , wherein the output optical assembly ( 5 ) is movable to adjust the position of the focal point (P F ).
15. A lighting fixture as claimed in claim 1 , wherein the output optical assembly ( 5 ) comprises a biconcave first lens (L 1 ).
16. A lighting fixture as claimed in claim 15 , wherein the output optical assembly ( 5 ) comprises a biconvex second lens (L 2 ) coupled to the biconcave first lens (L 1 ).
17. A lighting fixture as claimed in claim 16 , wherein the output optical assembly ( 5 ) comprises a biconvex third lens (L 3 ) located a third distance (D 3 ) from the biconvex second lens (L 2 ).
18. A lighting fixture as claimed in claim 17 , wherein the third distance (D 3 ) is roughly 1 mm.
19. A stage lighting fixture comprising:
a casing having a first end and a open second end;
a short-arc lamp, which is housed inside the casing ( 2 ), close to the first end ( 9 ), and emits a light beam;
a reflector ( 4 ), which is coupled to the short-arc lamp; to direct the light beam along an optical axis; is shaped and spaced apart from the short-arc lamp to concentrate the light beam substantially at a work point (P L ) located along the optical axis and
an output optical assembly ( 5 ), which is located at the second end of the casing, is configured to have a focal point (P F ) located along the optical axis, and is spaced apart from the short-arc lamp so that the focal point coincides with the work point
wherein the optical assembly ( 5 ) comprises at least one lens which is located at the open end ( 10 ) of the casing ( 2 ).
20. A stage lighting fixture comprising:
a casing having a closed first end and a open second end;
a short-arc lamp, which is housed inside the casing ( 2 ), close to the first end ( 9 ), and which emits a light beam;
a reflector ( 4 ), which is coupled to the short-arc lamp; to direct the light beam along an optical axis; is shaped and spaced apart from the short-arc lamp to concentrate the light beam substantially at a work point (P L ) located along the optical axis and
an output optical assembly ( 5 ), which is located at the second end of the casing, is configured to have a focal point (P F ) located along the optical axis, and is spaced apart from the short-arc lamp so that the focal point coincides with the work point
axis wherein the optical assembly ( 5 ) is the most downstream processing element along the optical axis.