Lighting device with narrow light emitting area
A lighting device contains light-emitting elements and has an elongated shape. The lighting device has a housing that has reflective side walls extending in a longitudinal direction of the housing; a cavity formed between the reflective side walls; and light-emitting elements arranged at least partially along the longitudinal direction relative to each other in the cavity. An opening of the cavity forms a light-emitting area, A width of the cavity expands from the light-emitting elements towards the opening at least in sections. A reflective element covers at least a section of the opening and reflects a part of light emitted from the light-emitting elements towards the cavity and reduces a width of the light-emitting area compared to a width of the opening.
1. A lighting device comprising:
a housing, the housing comprising:
reflective side walls extending in a longitudinal direction of the housing;
a cavity formed between the reflective side walls, an opening of the cavity forming a light-emitting area of the lighting device; and
light-emitting elements arranged at least partially along a longitudinal direction relative to each other in the cavity, a width of the cavity expanding from the light-emitting elements towards the opening at least in sections; and
a reflective element integral with the housing and covering at least a section of the opening, the reflective element configured to reflect a part of light emitted from the light-emitting elements towards the cavity, the reflective element configured to reduce a width of the light-emitting area compared to a width of the opening and having a reflectivity that decreases from an edge region of the opening to a central region of the opening.
2. The lighting device of claim 1 , wherein the reflective element forms a slit-shaped light-emitting area on the opening.
3. The lighting device of claim 1 , wherein:
the reflective element has side surfaces, and
the reflective element is configured to reflect the part of light emitted from the light-emitting elements towards the cavity by means of total internal reflection on the side surfaces.
4. The lighting device according to claim 3 , wherein the side surfaces for total internal reflection taper from the opening towards the light-emitting area at least in sections.
5. The lighting device of claim 1 , wherein the cavity is at least partially filled with a transparent filler material.
6. The lighting device of claim 1 , wherein at least part of the housing is flexible.
7. The lighting device of claim 1 , wherein the reflective element is flexible.
8. A lighting device comprising:
a housing, the housing comprising:
reflective side walls extending in a longitudinal direction of the housing;
a cavity formed between the reflective side walls, an opening of the cavity forming a light-emitting area of the lighting device; and
light-emitting elements arranged at least partially along a longitudinal direction relative to each other in the cavity, a width of the cavity expanding from the light-emitting elements towards the opening at least in sections;
a mechanical fixture; and
a reflective element covering at least a section of the opening, the reflective element configured to reflect a part of light emitted from the light-emitting elements towards the cavity, the reflective element configured to reduce a width of the light-emitting area compared to a width of the opening, the reflective element formed on the mechanical fixture separate from the housing.
9. The lighting device of claim 8 , wherein the reflective element forms a slit-shaped light-emitting area on the opening.
10. The lighting device of claim 8 , wherein the reflective element has a reflectivity that decreases from an edge region of the opening to a central region of the opening.
11. The lighting device of claim 8 , wherein:
the reflective element has side surfaces, and
the reflective element is configured to reflect the part of light emitted from the light-emitting elements towards the cavity by means of total internal reflection on the side surfaces.
12. The lighting device according to claim 11 , wherein the side surfaces for total internal reflection taper from the opening towards the light-emitting area at least in sections.
13. The lighting device of claim 8 , wherein the cavity is at least partially filled with a transparent filler material.
14. The lighting device of claim 8 , wherein at least part of the housing is flexible.
15. The lighting device of claim 8 , wherein the reflective element is flexible.
16. A method for producing a lighting device, the method comprising:
providing a housing, the housing comprising:
reflective side walls extending in a longitudinal direction of the housing,
a cavity formed between the reflective side walls, an opening of the cavity forming a light-emitting area of the lighting device, and
light-emitting elements arranged at least partially along a longitudinal direction relative to each other in the cavity, a width of the cavity expanding from the light-emitting elements towards the opening at least in sections;
covering at least a section of the opening with a reflective element, the reflective element configured to reflect a part of light emitted from the light-emitting elements towards the cavity, the reflective element configured to reduce a width of the light-emitting area compared to a width of the opening, the reflective element being at least one of moulded or filled on the opening; and
bending the housing into a predetermined shape and inserting the housing into a mechanical fixture.
17. A method for producing a lighting device, the method comprising:
providing a housing, the housing comprising:
reflective side walls extending in a longitudinal direction of the housing,
a cavity formed between the reflective side walls, an opening of the cavity forming a light-emitting area of the lighting device, and
light-emitting elements arranged at least partially along a longitudinal direction relative to each other in the cavity, a width of the cavity expanding from the light-emitting elements towards the opening at least in sections,
covering at least a section of the opening with a reflective element, the reflective element configured to reflect a part of light emitted from the light-emitting elements towards the cavity, the reflective element configured to reduce a width of the light-emitting area compared to a width of the opening; and
bending the housing into a predetermined shape and inserting the housing into a mechanical fixture, the reflective element formed on the mechanical fixture.
18. The method of claim 17 , wherein the reflective element has a reflectivity that decreases from an edge region of the opening to a central region of the opening.
19. The method of claim 17 , wherein:
the reflective element has side surfaces,
the reflective element is configured to reflect the part of light emitted from the light-emitting elements towards the cavity by means of total internal reflection on the side surfaces, and
the side surfaces for total internal reflection taper from the opening towards the light-emitting area at least in sections.