The application claims priority to U.S. Provisional Application No. 60/592,509 filed Jul. 29, 2004, which is incorporated in its entirety herein.
1. Field of the Invention
The present invention relates to recessed light fixtures, more specifically to recessed light fixtures for use in medical facilities.
2. Description of Related Art
Recessed light fixtures are known, and are typically used when it is desirable to minimize the projection of the light fixture below the ceiling surface. Recessed light fixtures, as opposed to light fixtures that substantially extend below the ceiling surface, tend to be more aesthetically appealing and provide a cleaner look when installed. Thus, recessed light fixtures tend to be used in commercial settings such as offices and the like.
Some recessed light fixtures use a curved reflective surface mounted in a rectangular shaped housing. The light source or sources is/are mounted inside the housing near the curved surface and some type of diffuser is mounted below the light source so as to minimize the harsh effects of direct light. A common type of diffuser is a perforated shield. The combination of the diffuser and the curved reflective surface allow the light to exit the fixture in a more controlled and even manner so as to prevent unsightly bright or dark spots.
Another type of light fixture is a sealed light fixture for use in high abuse settings. Such sealed light fixtures are typically used in heavy commercial or industrial settings where the environment can be abusive to unsealed light fixtures because of moisture, dust and the like. These sealed fixtures tend to have a rectangular housing that is coupled to a plastic or glass diffuser. The diffuser is sealed along its edges to the fixture so that the light source and the internal components are protected from the surrounding environment. While functional, these light fixtures suffer from being relatively less attractive. Due to various constraints and different design considerations, the sealed light fixtures used in high abuse environments are designed so that the entire fixture extends below the ceiling and thus are more commonly used in situations where the ceiling is relatively high.
A second type of sealed fixture is used in a clean room setting. Clean rooms require a minimum amount of dirt and particles in the air and typically are kept clean via a laminar air flow that runs from the ceiling down to the floor. Light fixtures for use in clean rooms can be installed in the ceiling and often include a rectangular housing with a flange around the edge housing. The clean room light fixtures are recessed into the ceiling and sealed to the ceiling between the flange and the ceiling. A second seal is than provided between a plastic diffuser and the light fixture housing so that internal portion of the light fixture is sealed from the inside of the clean room. To avoid turbulence that allows the collection of dust or particles, these light fixtures use a flat diffuser that is close to flush with ceiling.
While the various light fixtures described above are effective in their respective environments, they are less suitable for use in a medical facility. What is needed is a light fixture that can provide some of the benefits provided by the above fixtures in a more aesthetically pleasing package while minimizing the cost of the fixture.
In an embodiment of the present invention, a light fixture is provided that has a concave-shaped structural reflector that also acts as the fixture enclosure. Two end caps are welded to the structural reflector so that the combination of the end caps and the structural reflector forms a rectangular like opening. Inside the opening a reflector is positioned longitudinally along the center of the rectangular opening. The reflector has a first optics area and a second optics area and a third optics area. Two high output linear light sources are mounted adjacent the first optics area. A first lower output linear light source is mounted adjacent the second optics area and a second lower output linear light source is mounted adjacent the third optics area. A curved diffuser is sealably mounted to the structural reflector so as to substantially seal the interior portion of the light fixture from dust accumulation. Preferably the curved diffuser has a smooth exterior surface so as to minimize dust and bacteria collection on the exterior surface and to facilitate easy cleaning of the diffuser.
The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which:
a is an illustration of a cutaway isometric view of the light fixture depicted in
b is an illustration of an alternative embodiment of the light fixture depicted in
c is an illustration of an alternative embodiment of the light fixture depicted in
a is an illustration of a partial cross-sectional view of an exemplary embodiment with the diffuser being installed.
b is an illustration of the embodiment depicted in
Light fixtures for use in medical facilities have requirements somewhat different than the requirements of a typical office. The requirements are even more unique when the light fixture is installed directly above the patient in a hospital room. In such a circumstance it is desirable that the light fixture provide an attractive appearance but be easy to clean so as to avoid or at least minimize the accumulation of dust and germs. In addition, it is desirable to have a light fixture that has at least two modes of operation, an ambient mode and an examination mode.
The structural reflector 20 and the end caps 22 and 23 are preferably die-formed out of a 20 gauge cold rolled steel alloy. The light fixture housing 11, once assembled, is preferably coated with a white reflective paint so as to provide a high level of reflectivity. In an embodiment, the coating is a polyester powder coat applied over a 5-stage process and the coating preferably has a reflectance of 94% or more.
In an embodiment, the diffuser 700 consists of a frosted acrylic configured to minimize visibility of the underlying linear light sources while maximizing the efficiency of the light fixture. For example, the diffuser could be made of an extruded, low brightness, DR acrylic.
As can be appreciated, various known electrical components typically used in a linear light source fixture are required. These components are known in the art and, therefore, further discussion regarding the various electrical components is not required. The housing 11 may additionally include one or more holes suitable for the purpose of either accepting wires and/or for allowing various electrical components to be installed within or connected (either directly or indirectly) to the housing in a known manner.
As can be noted, the end caps 22 and 23 are preferably attached to the structural reflector 20 so that there is little or no gap between the end caps 22 and 23 and the structural reflector 20. Preferably the end caps 22 and 23 are welded to the structural reflector 20 so as to minimize any gap between the structural reflector 20 and the end caps 22 and 23. The minimizing of the gap between the end caps 22 and 23 and the structural reflector 20 has the benefit of reducing the visibility of dark lines within the fixture that might otherwise make the fixture appearance undesirable and/or unacceptable. Additionally, welding the end caps 22 and 23 to the structural reflector 20 can provide additional structural rigidity.
As depicted, the optical reflector 30 has a first optics area 40, a second optics area 41 and a third optics area 42. As depicted, optics area 40 is has three sides that provide a channel like appearance. In an exemplary embodiment, the light fixture is configured to accept two high output linear light sources such as a T5 high output bulb in lamp holders 51 and 52. Thus, in an exemplary embodiment, the primary function of the first optics area 40 is configured to provide reflectivity for the high output linear light sources. In such an exemplary embodiment, the lamp holders 54 and 55 can be configured to accept T8 bulbs. Thus, in such an exemplary embodiment, the primary function of the optics areas 41 and 42 are to provide reflectivity for the T8 bulbs installed in lamp holders 54 and 55. Typically, lamp holders are placed on both ends of a light source such as a T5 or T8 bulb. Thus, it is contemplated that a lamp holder corresponding to each of the lamp holders 51, 52, 54 and 55 may be included on the opposite end of the light fixture so that in operation the light sources can be securely installed and an electrical circuit is formed. In other words, the use of pairs of lamp holders is contemplated and can allow the lamp to be mounted on the light fixture housing 11 (
As can be appreciated, the use of a T5 high output bulb can be advantageous because of the relatively high light output levels of a T5 high output bulb as compared to more commonly used bulbs having lower levels of light output. In an exemplary embodiment, the use of two T5 high output bulbs in combination with two T8 bulbs provides sufficient illumination such that a physician can readily examine the patient. In such an embodiment there is little need for additional illumination, thus the physician typically will not have to use additional light sources during the examination.
Thus, a potential advantage of a preferred embodiment of the present invention is to provide sufficient light in the examination mode so as to eliminate secondary light sources. The reduction of secondary light sources has an obvious cost benefit. In addition, reducing the need for secondary light sources can be advantageous because there is typically limited space inside a patient's room, thus eliminating the need for secondary light fixtures can reduce the clutter and typically results in a more aesthetically pleasing environment for the patient. Naturally, a pleasing environment tends to aid in patient morale and can even improve patient recover time due to the positive psychological effects that a pleasing environment brings.
As depicted in
a illustrates a further close-up view of the light fixture depicted in
It should be further noted that while
A seal 81 is mounted on the bracket 80. For purposes of illustration the seal only extends along a portion of the mounting surface of the bracket 80. Preferably, however, the seal extends along most if not all of the entire surface of the bracket 80.
A rail 82 is mounted to the structural reflector 20 and preferably extends the longitudinal length of the light fixture. As depicted, there is a gap depicted between the rail 82 and the bracket 80. While it is preferable to minimize such gaps so as to maximize the sealing of the light fixture, such a gap may be useful to aid in the installation and removal of light bulbs in the fixture. As will be apparent to one of skill in the art, eliminating the gap requires a sufficient room to angle the light source so as to enable installation. Even with the gap it can be appreciated that the sealing is sufficient to substantially reduce the accumulation of dust and bacteria on an interior portion of the light fixture, the interior portion being the components and surfaces protected by the diffuser. As can be further appreciated, the rail 82 is approximate the optics area 42, thus, as depicted, the rail 82 is approximate the square portion 20b (
Turning to
c illustrates an alternative embodiment of the light fixture depicted in
Referring again to
As shown in
The diffuser 700 further includes interior surfaces 710, 712 and 714. As depicted, each of the interior surfaces 710, 712 and 714 include multiple linear prisms that extend the full longitudinal direction of the diffuser 700. For example, interior surface 710 includes linear prisms 720, 722 and 724. The linear prisms 720, 722 and 724 diffuse and distribute light from the light source more evenly and thus avoid the appearance of “hot spots,” or focused light, emanating from the fixture. In certain settings, it may be preferable to position the linear prisms on the exterior surfaces 704, 706 and 708 for reasons relating to optics and light transmission. However, in a preferred embodiment, the linear prisms 720, 722 and 724, if used, are positioned on the interior surfaces 710, 712 and 714 so that the outer surface is smooth, such that dust and contaminants do no accumulate on the diffuser and so that the diffuser is easier to clean.
As shown in
As depicted, the diffuser 700 includes a pair of lips 730, 732 that extend longitudinally along the entire length of the diffuser 700. As shown in
The diffuser 700 is preferably constructed of a flexible material so that it can be flexed and bent to engage the light fixture as described above without cracking. Further details of the engagement of the lip 732 with the rail 82 are shown in
The diffuser is sealed to the structural reflector fixture along the length of the structural reflector 20 so that the outer solid surfaces 704, 706 and 708, as well as the engagement of the lips 730, 732 with the rails 82, 83, help prevent the flow of air, dust and impurities onto the light source and the inner portion of the fixture.
The diffuser 700 sealably mounts to the rails 82 and 83 and the bracket 80. The gasket 81 provides a sealing function between bracket 80 and diffuser 700. When installed, the diffuser 700 compresses the gasket 81, thus the gasket 81 also aids in providing a sealing force along the interface between the rails 82 and 83 and the diffuser 700. Preferably, the gasket 81 is made of closed cell foam.
In an embodiment, the dimensions of the light fixture are 5.25 inches high by 24 inches wide by 48 inches long. As can be readily appreciated by one of skill in the art, depending on the diffuser, the light sources, and the geometry of the reflective surfaces, the width and height can be adjusted. Naturally, the length can also be adjusted to meet the requirements of the particular user; preferably the length is such that a standard light source can be used with the recessed light fixture (i.e. the fixture is configured to accept a light source that is 2 feet long, 4 feet long, etc. . . . ).
In an exemplary embodiment, the light fixture 10 includes two modes, an ambient light mode and an examination mode. In an embodiment, providing power to the light fixture activates the ambient light mode, which provides power to the two T8 bulbs so as to provide a moderate light level on the surface below the light fixture. When the fixture is switched to examination mode, electrical power is additionally supplied to the two T5 high output bulbs, so that all four bulbs are illuminated. This substantially increases the level of light illuminating the surface below the light fixture so as to aid an individual examining a patient. Preferably, the area of increased illumination covers the majority of a patient situated below the light fixture.
In an exemplary embodiment using two T8 bulbs and two T5 high output bulbs, during ambient mode (which activates the two T8 bulbs) a 4 feet by 2 feet recessed light fixture provides between 35 and 43 foot-candles of illumination on a 4 feet by 2 feet area about 60 inches below the light fixture. When switched to examination mode (which activates all four bulbs), the same exemplary embodiment provides between 99 and 122 foot-candles of illumination on the same area at the same distance. As can be appreciated, the transition between ambient mode and examination mode could be accomplished more gradually via a known dimmer switch. Over time it is expected that the light output would gradually decrease depending on various environmental facts.
As can further be appreciated, the illumination over the entire length of the patient lying beneath the light fixture would be affected by a change between ambient and examination mode, however it is expected that the light level would tend to decrease as the distance from the light fixture increased. Positioning the light fixture over the expected center of the patient is expected to provide the most even light distribution, however it may be desirable to bias the placement of the light fixture so as to provide the maximum light where it is desired. Thus, a foot specialist might want to bias the light toward the patient's feet while an ear, nose and throat specialist might want to bias the light towards the patient's head.
a depicts a partial cross-sectional view of an exemplary embodiment with the diffuser about to be installed. The diffuser 700 is attached to the housing 11 (not shown) in-the following manner. First the one side, for example, the lip 730 of the diffuser 700 is attached to the rail 83.
Next, as depicted in
A partial cross-sectional view of an alternative embodiment of a light fixture 110 is depicted in
As depicted, the light fixture 110 includes an optics area 140. Lamp holders 151, 152 and 153 are mounted approximate the optics area 140 and are configured to accept light sources such as a T8 bulb. As depicted, a rail 182 and a rail 183 extend along both sides of an optics area 140. Thus, the diffuser 800 is configured to mount to the rails in a manner similar to that discussed above. A bracket and gasket, not shown, may be advantageously used to seal a portion of the ends of the diffuser 800 to the light fixture housing 111 in a manner similar to the bracket and gasket depicted in
In operation, power may be provided to all three bulbs receptors at the same time. Preferably all lamp holders are configured to accept the same type of bulb so that when a series of the light fixtures are installed along a hallway, for example, the light fixtures provide an attractive and relatively even light distribution that is easily maintained. The light fixtures can also be configured to have one or more modes of illumination; however, the cost of the fixture may be reduced if the light fixture is configured to provide a single mode of operation. Furthermore, in a hallway there may be less need for variations in light output.
While described in terms of mounting the fixture on the ceiling, it should be understood that the recessed light could also be mounted on a different surface such as a wall if so desired.
The present invention has been described in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.
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Number | Date | Country | |
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Number | Date | Country | |
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60592509 | Jul 2004 | US |