Illumination – Light source and modifier – Adjustable or repositionable modifier
Reexamination Certificate
2001-02-05
2003-05-13
O'Shea, Sandra (Department: 2875)
Illumination
Light source and modifier
Adjustable or repositionable modifier
C362S295000, C362S322000, C362S346000
Reexamination Certificate
active
06561678
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to lighting fixtures and, more particularly, to lighting fixtures providing indirect light or luminance. Still more particularly, the present invention relates to variable focus indirect lighting fixtures.
BACKGROUND ART
Indirect lighting is widely recognized as the best type of lighting as it provides even illumination without the glare of direct illumination from the light source. Indirect lighting which resembles lumination from a skylight is the most desirable type of lighting. The benefit of indirect lighting is that the source of light, i.e., the point of lumination, is never visible. It is similar to the illumination received on a cloudy day where the sun is not visible. The lack of glare is one of the prime benefits of indirect lighting. The even distribution of the lighting is also a major benefit.
Indirect lighting through skylights can be focused on a specific area by the size of the skylight and the distance between the roof and the ceiling where the skylight is located. The ability to control indirect lighting to cover the space to be illuminated or the task area to be illuminated is not available through the use of commercially available lighting fixtures. Thus, there is a need in the art for an indirect lighting fixture control.
A prior approach to solving the problem of providing indirect lighting for indoor recessed lighting environments is a recessed, indirect lighting fixture, e.g., the Atrium fixture available from Eclairage Axis Lighting Inc.
FIG. 1
is a perspective view of the recessed, indirect lighting fixture of the prior art.
A recessed, indirect lighting fixture
10
is mounted in a typical office environment ceiling
12
. The ceiling
12
includes support beams
14
supporting ceiling panels
16
in a typical grid arrangement. These support beams
14
are normally suspended from an office space ceiling (not shown) via support wires (not shown). The lighting fixture
10
rests on, or is attached to, support beams
14
and fully covers an opening
15
in ceiling
12
of the same size as ceiling panel
16
. Typical ceiling panel
16
dimensions are either two foot square or two feet by four feet.
The lighting fixture
10
includes a light source
18
mounted above ceiling
12
on opposite interior sides of the fixture
10
and substantially vertically aligned over the support beam
14
. The light source
18
, e.g., a fluorescent light tube, is partially surrounded by a channel
20
, e.g., an aluminum extruded channel, extending coextensive with the opening
15
in the ceiling
12
for the fixture
10
. The channel
20
is generally U-shaped and directs light from light source
18
toward a concave surface
21
formed by a curved reflector
22
forming a portion of the top surface of fixture
10
.
Two curved reflectors
22
are joined together at common edges along a centerline of fixture
10
to form an upper side of the fixture. A single piece of material having two curved portions may be used in place of two separate pieces being joined. The transversely extending ends of the fixture
10
not having light source
18
have a substantially vertical end wall
24
connected to each of the curved reflectors
24
along a top edge and rest on, or are attached to, a transverse beam support
14
a
along a lower edge thereof.
Using the above-described lighting fixture
10
, light is transmitted from light source
18
toward the concave surface
21
of curved reflector
22
. The light reflects off concave surface
21
and passes through opening
15
to illuminate the office space below ceiling
12
. As depicted in the side view of fixture
10
in
FIG. 2
, the angle of light distribution
26
using the recessed, indirect lighting fixture described above is approximately one hundred fifty (150) degrees. Thus, the fixture
10
provides a uniform light distribution over a large angle. However, there are many situations where a uniform distribution of light is needed only in a specific location, e.g., conference rooms, television studios, football or basketball arenas. In these situations, it is desirable to have more light on a specific subject or location, e.g., players on the basketball court or documents being read at a conference table, and fixture
10
is not able to focus the light as required. Therefore, there is a need in the art for a focussed indirect lighting fixture.
Further, certain applications of indirect lighting require different focus settings at different times. For instance, if a person is making a presentation in a conference room the lighting should be focussed on the presenter and the presentation, i.e., a narrow focus; however, if a discussion is occurring at the conference table, the lighting should be focussed on the table and any documents at the table, i.e., a broader focus. A typical solution for multiple levels of lighting focus is to use multiple differing light fixtures, e.g., recessed fluorescent lighting for a broader focus and incandescent directional lighting for narrow focus. Thus, there is a need in the art for a variable focus indirect lighting fixture.
The current practice in lighting is to use uplighting on suspended fixtures using the ceiling as the reflector. This practice is extremely inefficient and impractical and creates hot spots on the ceiling without controlling where the light is to be directed.
Current practice and currently available products on the market are all fixture designs with the lamps and reflectors being set with no adjustability or variation available either from the factory or in the field at the fixture. A field adjustable lighting fixture is particularly suited to television studios or video conferencing rooms. In television studios, the trend is toward the use of fluorescent lighting because such lighting provides a more uniform lumination lacking hot spots at a more comfortable cooler temperature, i.e., the person or persons under the light are not subjected to heat from the lights. The use of variable focus direct lighting fixtures has long been used in theater and television studios to control the beam spread of the luminaires.
Television studios have long used skrims or diffusers over either incandescent or fluorescent fixtures to soften the effect of the light source. Unfortunately, this has resulted in fires from the very hot incandescent lamps and a loss of light intensity when used with fluorescent lamps. A variable focus indirect lighting fixture would allow open aperture fixtures to efficiently disperse light over a controllable area with no glare and no direct light. Therefore, there is a need in the art for a variable focus indirect lighting fixture for use in television studios, video conference rooms, and theaters.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a variable focus indirect lighting fixture.
Another object of the present invention is to provide a variable focus indirect lighting fixture for use in television studios, video conference rooms, and theaters.
The above-described objects are achieved by a variable focus indirect lighting fixture. The lighting fixture has a pair of first reflectors with each reflector arranged to substantially surround a light source, and a second variable focus reflector positioned in front of the first reflectors. Each of the first reflectors has an opening arranged to direct lumination from the light source. The second reflector is positioned in front of each opening of the pair of first reflectors and arranged to receive and reflect the lumination from each light source passing through each opening of the pair of first reflectors. The second reflector has a pair of inner, concave surfaces arranged such that each inner surface faces a respective opening of the first reflectors and is arranged to receive and reflect the lumination from the respective light source passing through the opening of each of the first reflectors. The inner surfaces are aligned along a center line of the second reflector between the pair of first reflectors. The center li
Lowe Hauptman & Gilman & Berner LLP
Neils Peggy A.
O'Shea Sandra
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