The present disclosure is related generally to filters for fluorescent lighting tubes. In particular, a removable sleeve for filtering various wavelengths of the electromagnetic spectrum emitted by fluorescent lights.
Fluorescent tubes produce light that creates little heat, consumes minimal power and provides an even distribution of illumination. In several areas of the lighting industry, it is often desirable to alter the color of the light produced by a fluorescent tube. Typically, plastic filters of various color coatings are used to accomplish these alterations.
Additionally, specific coatings can be added to the filter that blocks ultraviolet light produced by the fluorescent tube. Ultraviolet light can damage objects in a similar manner that sunlight damages skin. Blocking ultraviolet light produced by the fluorescent tube is especially desirable when lighting museum collections and other valuable objects.
Many different colors of a plastic or polyester film are available to alter the color of any lighting fixture including a fluorescent tube. See Apollo Design Technology's web page http://www.internetapollo.com/products/productline.aspx?pl_id=8. This flat translucent or transparent polymeric film, known to those familiar with the art, is called gel. This name most likely refers back to the early days of theater when a gelatin material was used to manufacture color filters for stage lighting.
One of the challenges encountered is how to attach a flat gel material to fluorescent lights, which are usually long, slender tubes of glass. Several products have been designed to aid in the process of adding colored gel to fluorescent tubes. See the product named “Super Tube” at www.gamonline.com by Great America Lighting. See also http://www.internetapollo.com/products/productline.aspx?pl_id=33 by Apollo Design Technology, Inc.
The drawback of the aforementioned products is that the fluorescent tube must be removed from the fixture in order to place the colored sleeve over the tube. This becomes a labor intensive when more than a few fixtures must be colored.
Another approach to adding color to fluorescent tubes is disclosed in U.S. Pat. No. 6,511,204, which discloses an elongated polycarbonate configured to fit over a fluorescent tube and sleeve adapted to receive a colored film sheet for altering the light output characteristics of the fluorescent tube. One drawback with this product is that a semi rigid polycarbonate tube must be clipped over the fluorescent lamp. Subjecting a long tube of thin glass to this additional pressure could create a safety issue during installation. Additionally, even greater pressures are added when the colored sleeve is removed from the fluorescent tube. This could lead to the tube falling to the floor or even shattering overhead.
The present disclosure is for a filter for a fluorescent lighting tube. The filter includes a sheet of polymeric material having fold lines scribed thereon, defining a number of sections. The sections allow the filter to be positioned about and secured to a fluorescent tube without removal of the tube from its mounting fixture. The filter of the present disclosure may filter color, ultraviolet light, or other wavelengths of the electromagnetic spectrum.
While the present disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, embodiments with the understanding that the present description is to be considered an exemplification of the principles of the disclosure and is not intended to be exhaustive or to limit the disclosure to the details of construction and the arrangements of components set forth in the following description and illustrated in the drawings.
Referring to
Filter 10 includes a number of sections. The exemplary embodiment is shown as having four sections, A, B, C, and T. The width of each section is determined based upon the diameter X of the intended fluorescent tube 2. Each section is sized such that filter 10 when expanded, as shown in
For example, in the exemplary embodiment of the filter 10 having four sections, the filter 10 is configured such that when expanded and disposed about a fluorescent tube 2 the four sections allow the polymeric film to take on a triangular cross-section around the fluorescent tube. The length of a side of an equilateral triangle is related to the diameter of a circle inscribed therein by the formula:
wherein C is the length of the triangle side and X is the diameter of the inscribed circle. Thus, the width of section C should be greater than 1.73X. To allow folding of the filter, as shown in
Each section is separated by fold line 14, 16, 18. Each fold line may be a region of reduced film thickness, for example a scribe line. In the exemplary embodiment, after the polymeric film 12 is cut to size, fold lines 14, 16, and 18 are laser scribed into the polymeric film. Polymeric film 12, of the type employed in the filter of the present disclosure may have a thickness on the order of 0.003 inch. Fold lines 14, 16, 18 may be scribed by removing approximately 0.0015 inch of material from polymeric film 12 at the desired locations, or approximately half the film thickness. As should be apparent to one of skill in the art, any scribing method is appropriate and the present disclosure should not be construed as being limited to laser scribing the fold lines. However, laser scribing does result in the benefit of producing a line that is invisible on the face of the film 12.
Scribing film 12, only slightly changes the natural memory of the film material. When the filter 10 is configured in an expanded arrangement, as shown in
An alternative embodiment as shown in
Thermal or ultrasonic welds 24, 26, 28, 30 may also be located on the fold lines 14, 16, 18, 20 (respectively) as shown in
Sections A, B, C and D can vary in width. This feature allows the filter 10 to be collapsed into the shape illustrated in the folded end views of
The filter 10 of the present disclosure is configured to form a triangular cross section, however, the filter may have more or fewer sides and still be within the scope of this disclosure. Referring to
This application claims the benefit of priority under 35 U.S.C. §119 to U.S. Provisional Patent Application Ser. No. 60/987,810 filed on Nov. 14, 2007.
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2820918 | Aronstein | Jan 1958 | A |
3418651 | Jacobson | Dec 1968 | A |
4642086 | Howarth, Jr. | Feb 1987 | A |
5121312 | Hyland et al. | Jun 1992 | A |
5571280 | Lehrer | Nov 1996 | A |
6511204 | Emmel et al. | Jan 2003 | B2 |
20070091619 | Lee | Apr 2007 | A1 |
Number | Date | Country | |
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20090129091 A1 | May 2009 | US |
Number | Date | Country | |
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60987810 | Nov 2007 | US |