Illumination – Revolving
Reexamination Certificate
1999-09-09
2001-05-29
O'Shea, Sandra (Department: 2875)
Illumination
Revolving
C362S027000, C362S269000, C362S295000
Reexamination Certificate
active
06238054
ABSTRACT:
The invention relates to a lighting apparatus for display back-lighting.
PRIOR ART
Such a lighting apparatus has been disclosed, for example, by European laid-open Specification EP 0 607 453 A1. This specification describes a display back-lighting which comprises an essentially rectangular, translucent panel and an L-shaped fluorescent lamp. The fluorescent lamp rests on two edges of the translucent panel. Both legs of the L of the lamp are provided with a screen designed as a reflector.
DESCRIPTION OF THE INVENTION
The object of the invention is to provide a lighting apparatus, especially a display back-lighting, with a continuously variable brightness.
The lighting apparatus according to the invention possesses at least one electric lamp and a translucent, light-diffusing panel having at least one edge extending in a straight line, along which the at least one electric lamp is arranged and is fixed by means of a mounting. The at least one electric lamp is, according to the invention, designed as an aperture lamp having a cylindrical lamp envelope which is mounted in the mounting to rotate about its cylindrical axis. Furthermore, the lighting apparatus advantageously possesses a light absorber, which absorbs the light emitted by the at least one aperture lamp and not input into the light-diffusing panel. By rotation of the at least one aperture lamp about its axis, the quantity of light input into the light-diffusing panel can be continuously varied and the brightness of the lighting apparatus set accordingly. Maximum brightness is obtained if the aperture of the aperture lamp faces the edge of the light-diffusing panel with its entire width. By rotation of the at least one aperture lamp, the effective width of the aperture is reduced and the light input into the light-diffusing panel is reduced in accordance with the angle of rotation. The light absorber absorbs the fraction of the light emitted by the at least one aperture lamp which is not input into the light-diffusing panel.
Advantageously, the lighting apparatus according to the invention possesses an operating unit provided with a dimmer circuit for the at least one electric lamp. As a result, the lighting apparatus according to the invention can be dimmed not only mechanically but also electrically and an even finer gradation of brightness achieved. The mounting of the at least one electric lamp is advantageously designed as a tube enclosing the lamp and moulded onto the at least one edge extending in a straight line. In this case, the light absorber advantageously consists of an opaque coating of the tubular mounting. The light absorber may, however, also advantageously be designed as an opaque screen for the at least one electric lamp, which is for example snapped onto the lamp envelope or otherwise fixed to the lamp or to the diffusing panel. The width of the aperture of the at least one aperture lamp is advantageously matched to the thickness of the light-diffusing panel, in order to ensure minimal radiation of light in directions other than towards the panel edge. Advantageously, the lighting apparatus according to the invention is equipped with a rotary apparatus for rotating the at least one lamp about its axis and with a setting wheel for actuating the rotary apparatus. The setting wheel is advantageously additionally linked to the dimmer circuit. As a result, the lighting apparatus is simultaneously dimmed mechanically and electrically.
According to the particularly preferred example of embodiment of the invention, the lighting apparatus possesses a light-diffusing panel with two mutually opposite edges extending in a straight line, along each of which an aperture lamp is arranged. As a result, a uniform distribution of brightness over the light-diffusing panel is achieved. The rotary apparatus is preferably connected to the two aperture lamps in a manner such that the actuation of the setting wheel triggers a simultaneous rotary movement of the two lamps in opposite directions about their respective axes.
REFERENCES:
patent: 2721256 (1955-10-01), Duhon
patent: 3399476 (1968-09-01), Davis
patent: 4244130 (1981-01-01), Frois
patent: 5309338 (1994-05-01), Liu
patent: 5499165 (1996-03-01), Holmes, Jr.
patent: 5645337 (1997-07-01), Gleckman
patent: 5779339 (1998-07-01), Konishi et al.
patent: 6050704 (2000-04-01), Park
patent: 0 607 453 A1 (1994-07-01), None
patent: 451969 (1949-10-01), None
patent: 6-186433 (1994-07-01), None
Clark Robert F.
Neils Peggy C
O'Shea Sandra
Patent-Treuhand-Gesellschaft fuer elektrishe Gluehlampen mbH
LandOfFree
Dimmable lighting apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dimmable lighting apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dimmable lighting apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2524926