WO2005124222A1 - Portable lighting system with adjustable focus - Google Patents

Abstract

A device for providing illumination comprises a housing (18) containing one or more batteries, an opening (24) in the housing fitted with a mounting disc (30) and an optic plate (36), and a cap (42) to secure the mounting disc to the optic plate. A light source is fixed to the mounting disc. The light emitted form the device can be focused to a beam through rotation of the optic plate (36). The device can serve as a portable light and ahas means for hanging the device so that it points down or against a vertical surface. The housing is shaped in such a way to position a flat solar panel fixed to the housing in an optimum angle for charging when mounted to a vertical surface.

Description

PORTABLE LIGHTING SYSTEM WITH ADJUSTABLE FOCUS CROSS REFERENCE TO RELATED APPLICATION This application claims benefit, under 35 U.S.C. § 119(e), of U.S. Provisional Patent Application No. 60/579,216, entitled "PORTABLE LIGHTING SYSTEM WITH ADJUSTABLE FOCUS," filed June 14, 2004, which is hereby incorporated by reference in its entirety.

BACKGROUND OF INVENTION 1.6 billion people in the world do not have access to electrical lighting. See for example, International Energy Agency (IEA) in Outlook 2002 (IEA, Paris 2002), chapter 13, which is hereby incorporated by reference in its entirety. In India alone, between 150 and 300 million people rely on the faint, smoky and unhealthy glow of simple kerosene lamps. Kerosene is inefficient and dangerous, leading to respiratory problems, accidental fires and burns. The lack of quality light impacts all areas of life, especially education. Kerosene lamps are a significant contributor to greenhouse gases, each lamp accounting for between 30kg and 250kg of carbon dioxide emissions every year. It has been estimated that fuel-based lighting is responsible for annual energy consumption of 77 billion liters of fuel worldwide (or 2800 petajoules, PJ), at a cost of 38 billion/year or $77 per household. This equates to 1.3 million barrels of oil per day, on a par with the total fuel production of Indonesia, Libya, or Quatar, or half that of prewar Iraq. See Mills, 2005, "The Spector of Fuel-Based Lighting," Science 308, pp. 1263, which is hereby incorporated by reference in its entirety. One alternative to kerosene lighting is a connection to a commercial electric grid. However, in remote areas of developing countries, the cost of extending the commercial grid is overwhelming. Another alternative is portable lighting (flashlights) using disposable batteries. These have the drawback of high cost for replacing batteries and a design that usually does not allow for a diffused or broad beam useful for ambient lighting. Other common alternatives are small solar-based lanterns consisting of a solar panel, rechargeable battery, housing, and Compact Fluorescent Light (CFL) tube. These devices are useful for ambient lighting of a single room, but the large size of the bulb makes focusing the light to a bright task lighting beam very difficult. These CFL lanterns typically require an amount of energy that demands a costly battery and solar panel, and this becomes unaffordable to villagers in unelectrified regions. Recent developments in white light emitting diode (LED) lighting have made solar powered lighting solutions competitive with kerosene. Current kerosene expenditure in India is between $1 and $3 per month for an average unelectrified home. This can amount to over 10% of household income. Using new solar powered LED lighting devices provides an economic payback to the customer within about one year while providing a much higher quality of light. These systems can be designed to use less power, thus decreasing overall component size and cost. The smaller size allows for a more portable system, and the geometry of the LED bulb lends itself easily to focusing with a lens or reflector for task lighting. The white-light emitting diode is distinguished by a continuing trend toward increasing light output, declining costs per unit of output, and rising efficiency. See for example, Schubert and Kim, 2005, Science 308, 1274, which is hereby incorporated by reference in its entirety. What is needed is a lighting system generating greater light output compared to kerosene at an equivalent or lower cost over time. The lighting device may be the only light source available in a remote home. Therefore, a very robust system allowing both portable and indoor use and both task and ambient lighting is desirable. SUMMARY OF INVENTION The current invention provides an improved solution to light systems by increasing the portability of the entire light and solar panel system, increasing the durability of the housing, protecting the electronics in a near waterproof enclosure, and increasing the utility of a home light system by adding a means to create a bright, focused task light. This requires a unique form and orientation of components and novel processes for manufacturing and assembly. An embodiment of the invention provides a means of creating a portable light system using a single housing to contain all electronics, including batteries, and in some cases to act as a mounting stand for a fully integrated solar module. When used as a mounting stand, the housing acts to position the panel at an optimum angle relative to the sun. Because the light is portable, it is to be expected this light will be used outdoors. In one embodiment, the solar module is integrated with the housing, and this will require the entire light unit to be placed under direct or near direct sunlight. While left outdoors or used outside at night, it is likely the weather may change and expose the system to rain. Many chemistries of rechargeable batteries are appropriate for use in this embodiment of the invention. Nickel metal hydride (NiMH) and nickel cadmium (NiCD) batteries can be configured in an arrangement of several cells to provide the battery voltage required for the number and type of light sources used as well as to provide the number of hours of use that is required from each full charge. The housing of the apparatus in accordance with one embodiment of the present invention provides improved weather resistance by using a manufacturing process that allows the complete housing to be formed from a single piece, thus eliminating the presence of parting lines and gaskets. The process used is blow molding, wherein a tool with a rigid cavity is opened to receive a length of an extruded tube of polymer. The tool is closed and the perimeter of the cavity pinches around the extruded tube and forms an air-tight seal. The interior space of the extruded tube is then filled with compressed air. The extruded tube stretches to fill the mold cavity. Once the polymer has cooled, the tool is opened and the part is removed from the tool cavity. Many readily available and inexpensive materials can be used, such as polypropylene (PP) or high density polyethylene (HDPE). These types of materials are also very tough and resist cracking that might result from impacts on the device (e.g., when it is dropped). A one-piece construction reduces cost and reduces the risk of incomplete sealing. This construction also provides improved durability through the use of soft plastic materials that are not brittle under impact. These are commonly used in the production of bottles and containers using the blow mold process. The optic plate in accordance with one embodiment of the invention allows the light to have dual beam settings. One is a diffused beam suitable for ambient settings, and the other is a focused beam suitable for task lighting or outdoor use. The beam is adjusted by rotating the optic plate relative to the housing. The optic plate is partially constrained by a mounting disc placed in the opening of the housing. The optic plate can be molded using common optically clear polymers such as polycarbonate. A seal around a moving part is generally difficult and can involve costly gaskets and seals. The housing cap in accordance with one embodiment of the invention uses rib features integrally formed into the cap to create seals with internal components and to protect the electronics from the outdoor elements. The cap snaps onto the neck of the housing opening and secures all internal components within the interior space of the housing. The cap can be molding using many common low density polymers such as low density polyethylene (LDPE). Materials such as LDPE are pliable and facilitate use in a snap-fit relationship. One embodiment of the present invention is a device comprising (i) a housing having an opening and an internal cavity, (ii) one or more batteries located within said internal cavity, (iii) a mounting disc attached to the housing within the opening, the mounting disc having an outer surface directed away from the housing, (iv) a light source mounted adjacent to the mounting disc, wherein the light source is in electrical communication with the one or more batteries and the light source is directed generally away from the outer surface, (v) an optic plate having a light-modifying section rotatably mounted to the mounting disc so that the optic place is rotatable between (a) a modifying orientation wherein a light from the light source is modified and (b) a non-modifying orientation wherein the light from the light source is not modified, and (vi) a cap secured to the housing around the opening, wherein the cap is sized and shaped to hold the optic plate and the mounting disc to the housing and wherein the cap facilitates rotation of the optic plate with respect to the housing. Some embodiments further comprise a slip seal located between the cap and the optic plate such that the slip seal facilitates a sealing rotation of the optic plate and the optic plate can be selectively rotated while maintaining a sealed condition. In some embodiments, the slip seal is integrally formed with the cap. Some embodiments further comprise a static seal between the cap and the mounting disc. In some embodiments, the static seal is comprised of a circumferential tapered protrusion integrally formed with the cap. In still further embodiments of the present invention, there is a static seal between the mounting disc and the housing. This static seal can be, for example, comprised of a circumferential tapered protrusion integrally formed with the mounting disc. In some embodiments, the cap includes (i) a slip seal integrally formed with said cap and forming a sealing relationship against the optic plate, wherein the slip seal allows the optic plate to rotate while maintaining the sealing relationship, (ii) a static seal forming a sealing relationship between the cap and the mounting disc, wherein the static seal is comprised of a circumferential tapered protrusion integrally formed with the cap, and (iii) a static seal forming a sealing relationship between the mounting disc and the housing, wherein the static seal is comprised of a circumferential tapered protrusion integrally formed with the mounting disc. in some embodiments, the light source is comprised of one or more light emitting diodes. In some embodiments, the housing and the cap provide an interlocking means that is shaped and configured to prevent rotation of the mounting disc relative to the housing while allowing rotation of the optic plate relative to the mounting disc. In some embodiments, the device further comprises a solar collecting device that is in electrical communication with said the or more batteries. In some instances, the solar collector device is fixed onto the housing. In some embodiments, the housing comprises a hanging means such as a hook. Further, in some embodiments, the housing further has an angled protrusion that supports the solar collector (the solar collector is mounted on all or a portion of the housing protrusion). In some embodiments, the angled protrusion angles the solar collector between 10 degrees and 35 degrees from the vertical. In some embodiments, the housing is configured to mate with a removably attachable positioning means such that a combination of the housing and the positioning means provides additional angular positioning of the solar collector. In some embodiments, the housing comprises a first half and a second half that oppose each other and that are joined together. In such embodiments, all or a portion of the mounting disc is optionally integrally formed in the first half, the second half or both the first half and the second half of the housing. In still other embodiments, the light source forms a thermally conductive interface with a heat dissipating device. This heat dissipating device can comprise a protrusion configured to extend through an opening in a printed circuit board, the surface of the protrusion forming a thermally conductive interface with the light source. Further areas of applicability of the present disclosure will become apparent from the following detailed description. It should be understood that the detailed description and various examples, while indicating various embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the following claims.

BRIEF DESCRIPTION OF DRAWINGS The present invention will become more fully understood from the detailed description and the accompanying drawings.

FIG. 1 is a perspective view of the lighting device assembly in accordance with one embodiment of the invention. FIG. 2 is a perspective view of the lighting device in accordance with one embodiment of the invention with components expanded to view internal regions.

FIG. 3 is a cross-sectional view of one embodiment of the invention illustrating the components expanded in the assembly.

FIG. 4 is a cross-sectional view of one embodiment of the invention illustrating the components in the mating positions. FIG 5 is a cut-away view of the cap showing the interlocking features constraining rotation of the disc relative to the housing in accordance with one embodiment of the invention.

FIG 6a is a side view showing a device in accordance with an embodiment of the invention in a hanging position against a vertical surface creating an angle between the solar panel and horizontal of 10 and 35 degrees.

FIG 6b is a side view showing a device in accordance with one embodiment of the invention and a removably attached positioning device in a hanging position against a vertical surface.

FIG 7a is a perspective view of the light source attached to the heat dissipating device in accordance with one embodiment of the invention. FIG 7b is a cross-sectional view of the present invention illustrating the protrusion of the heat dissipating device contacting the light source.

DETAILED DESCRIPTION The following description of various embodiments is merely exemplary in nature and is in no way intended to limit the application or uses. With reference to Figure 1, a lighting system with adjustable focus 10 (system) is shown. System 10 includes a through hole 12 located within housing 18. Through hole 12 forms a handle 14 for use when carrying system 10 as a portable light. Hanging device 16 is fixed to housing 18 for use when hanging system 10 from a hook on a wall or ceiling. Open end 20 of housing 18 is fitted with internal electronic components allowing light to be emitted from surface 22. With reference to Figure 2, opening 24 in housing 18 provides access to internal cavity 26. Battery pack 28 is positioned within internal cavity 26. Many chemistries of rechargeable batteries are appropriate for use in this embodiment of the invention. Nickel metal hydride (NiMH) and nickel cadmium (NiCD) batteries can be configured in an arrangement of several cells to provide the battery voltage required for the number and type of light sources used as well as to provide the number of hours of use that is required from each full charge. Mounting disc 30 is removably attached within opening 24 such that outer surface 32 is directed away from housing 18. The light source 34 is positioned adjacent to mounting disc 30 in such a way as to direct light away from outer surface 32. An optic plate 36 is rotatably mounted to mounting disc 30 and has a light-modifying section 38 and a non-modifying section 40. Optic plate 36 is rotated into a light modifying orientation when light modifying section 32 is directly adjacent light to source 34 and is in a non-modifying orientation when non-modifying section 40 is directly adjacent to light source 34. Cap 42 is secured to housing 18 and holds optic plate 36 and mounting disc 30 in place. With reference to Figure 3, cap 42 includes a slip seal 44 integrally formed with cap 42 thereby forming a sealing relationship with optic plate 36 while allowing rotation between a modifying and non-modifying orientation. Cap 42 further includes tapered protrusion 46 integrally formed with cap 42 and forming a sealing relationship with mounting disc 30. Mounting disc 30 includes tapered protrusion 48 forming a sealing relationship with opening 24 of housing 18. The cross-sectional view of Fig. 4 shows slip seal contact region 50 between slip seal 44 and optic plate 36. Fig. 4 further illustrates static seal contact region 52 between tapered protrusion 46 on cap 42 and the mounting disc 30 in accordance with one embodiment of the present invention. Static seal contact region 54 is also shown between tapered protrusion 48 and housing 18. Figure 5 is oriented to show an interlocking means between cap 42 and housing 18 in which axial rib 56 is formed onto the exterior surface 62 of housing 18.

Axial rib 56 is positioned between a first axial rib 58 and second axial rib 60 formed onto the interior surface 66 of cap 42. Axial rib 64 is formed onto the perimeter surface 68 of mounting disc 30 and is positioned between axial rib 58 and axial rib 60. This interlocking means serves to prevent rotation of the mounting disc 30 relative to housing 18 while allowing rotation of optic plate 36 relative to housing 18. As shown in Figure 6a, solar collector 70 is shown fixed onto housing 18.

Hanging device 16 is shown coupled to hanger 72. Hanger 72 is fixed to vertical surface

74 of structure 76. With further reference to Figure 6a, housing 18 is shaped to position solar collector 70 at an angle to the horizon appropriate for efficient collecting of solar energy when in a hanging relationship to vertical surface 74. A horizontal solar collector is defined as being at zero degrees. A solar panel in a fixed position year-round is typically tilted down from horizontal at an angle approximately equal to the geographic latitude (measured from the equator). The angle will generally range from 10 to 35 degrees. With reference to Figure 6b, a removably attachable positioning means 78 is mated with housing 18 to provide additional angular positions while in a hanging relationship with hanger 72. With reference to Figures 7a and 7b, light source 34 forms a thermally conductive interface with heat dissipating device 80 at contact area 82. Contact area 82 is formed from one surface of protrusion 84 formed into heat dissipating device 80 contacting with the adjacent surface of light source 34. The protrusion 84 is sized to extend through an opening 88 in printed circuit board 86. All references cited herein are incorporated herein by reference in their entirety and for all purposes to the same extent as if each individual publication or patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety for all purposes. Many modifications and variations of this invention can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. The specific embodiments described herein are offered by way of example only, and the invention is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

What is claimed is:

1. A device comprising: a housing having an opening and an internal cavity; one or more batteries located within said internal cavity; a mounting disc attached to said housing within said opening, said mounting disc having an outer surface directed away from said housing; a light source mounted adjacent to said mounting disc, wherein said light source is in electrical communication with said one or more batteries and said light source is directed generally away from said outer surface; an optic plate having a light-modifying section rotatably mounted to said mounting disc so that said optic place is rotatable between (i) a modifying orientation wherein a light from said light source is modified and (ii) a non-modifying orientation wherein said light from said light source is not modified; and a cap secured to said housing around said opening, wherein said cap is sized and shaped to hold said optic plate and said mounting disc to said housing and wherein said cap facilitates rotation of said optic plate with respect to said housing.

2. The device of claim 1, further comprising a slip seal located between said cap and said optic plate, wherein said slip seal facilitates a sealing rotation of said optic plate so that said optic plate can be selectively rotated while maintaining a sealed condition.

3. The device of claim 2, wherein said slip seal is integrally formed with said cap.

4. The device of claim 1, further comprising a static seal between said cap and said mounting disc.

5. The device of claim 4, wherein said static seal is comprised of a circumferential tapered protrusion integrally formed with said cap.

6. The device of claim 1, further comprising a static seal between said mounting disc and said housing.

7. The device of claim 6, wherein said static seal is comprised of a circumferential tapered protrusion integrally formed with said mounting disc.

8. The device of claim 1, wherein said cap includes: a slip seal integrally formed with said cap forming a sealing relationship against said optic plate, wherein said slip seal allows said optic plate to rotate while maintaining said sealing relationship; a static seal forming a sealing relationship between said cap and said mounting disc, wherein said static seal is comprised of a circumferential tapered protrusion integrally formed with said cap; and a static seal forming a sealing relationship between said mounting disc and said housing, wherein said static seal is comprised of a circumferential tapered protrusion integrally formed with said mounting disc.

9. A device of claim 1, wherein said light source is comprised of one or more light emitting diodes.

10. The device of claim 1, wherein said housing and said cap provide an interlocking means that is shaped and configured to prevent rotation of said mounting disc relative to said housing while allowing rotation of said optic plate relative to said mounting disc.

11. The device of claim 1, the device further comprising a solar collecting device that is in electrical communication with said one or more batteries.

12. The device of claim 11, wherein said solar collector device is fixed onto said housing.

13. The device of claim 1, wherein said housing comprises a hanging means.

14. The device of claim 1 wherein said housing further comprises an angled protrusion and wherein said solar collector is mounted on said angled protrusion.

15. The device of claim 14 wherein said angled protrusion angles said solar collector between 10 degrees and 35 degrees from the horizontal.

16. The device of claim 15 wherein said housing is configured to mate with a removably attachable positioning means, wherein a combination of said housing and said positioning means provides additional angular positioning of said solar collector.

17. The device of claim 1 wherein said housing comprises a first half and a second half that oppose each other and that are joined together.

18. The device of claim 17 wherein all or a portion of said mounting disc is integrally formed in said first half, said second half or both said first half and said second half of said housing.

19. The device of claim 1 wherein said light source forms a thermally conductive interface with a heat dissipating device.

20. The device of claim 19 wherein said heat dissipating device comprises a protrusion configured to extend through an opening in a printed circuit board, the surface of said protrusion forming a thermally conductive interface with said light source.