AU2015100586B4 - Inflatable solar powered lamp - Google Patents

Abstract

A solar powered lamp is provided with flat ends and a translucent flexible housing, such that the housing can be inflated to form a free standing cylinder. A solar panel faces outward on one of the flat ends for recharging a low-profile rechargeable battery which, under the control of a printed circuit panel, powers an array of LEDs, which point into the lamp housing. Reflective surfaces, facing each other on opposite inside end walls of the lamp, maximize the diffusion of light from the LEDs. The lamp is a durable, portable, long light lighting solution for those who live off the electric power grid, victims of disaster, and the like. - 11 -

Description

INFLATABLE SOLAR POWERED LAMP BACKGROUND OF THE INVENTION Field of the Invention [0001] The invention is in the field of solar powered lighting devices. Description of the Related Art [0002] Patent publications US 2012/0120642 A (Shreshta) and US 2012/0224359 A (Chun) describe inflatable solar lights. The disclosed devices have an inconvenient shape and lack effective light-diffusing capabilities. [0003] It is desired to provide an inflatable, collapsible solar powered lamp, which can provide low cost lighting to people with unreliable access to electric power, including populations in the developing world and victims of disaster. Such lamp unit may also be used throughout the developed world as an energy-efficient, green portable lighting alternative. [0004] In providing such inflatable, collapsible solar powered lamp it would in particular be advantageous to devise a lamp with improved light diffusing capabilities, thus ameliorating or avoiding the problems with above identified prior art lamp units. - 1- SUMMARY OF THE INVENTION [0005] In accordance with one aspect of the present invention, there is provided a collapsible solar powered lantern, comprising: a collapsible lantern housing; a solar panel; a rechargeable lithium-ion battery; LED lights; and a circuit board; wherein the rechargeable battery is devised for recharging by laying the collapsible lantern housing in direct sunlight for 4 to 5 hours for complete charging. [0006] In accordance with a development of the above aspect, the invention also provides a collapsible solar powered lantern, comprising: a collapsible, translucent housing with flat circular end walls and a side wall; a valve for inflating the collapsible housing; a planar array of light emitting diodes (LEDs) arranged on a printed circuit board on one of the end walls; a rechargeable battery for powering the LEDs operatively connected to and preferably mounted to the printed circuit board; a solar panel adapted to recharge the rechargeable battery; a switch for powering the LEDs on and off; and at least one reflective surface at one of the flat circular end walls, wherein the reflective surface present at the LEDs-carrying end wall has apertures over the LEDs, the reflective surface(s) disposed to increase the diffused light from the lamp. -2- [0007] In accordance with a preferred embodiment of the invention, the solar powered lamp is provided with flat ends and a translucent flexible housing, such that the housing can be inflated to form a free standing cylinder. The solar panel faces outward on one of the flat ends for recharging the rechargeable battery, which in a preferred embodiment is a low-profile battery pack, under the control of the printed circuit panel, and serves to power the array of LEDs which are arranged to point into the lamp housing. Preferably, reflective surfaces are provided at both flat ends, facing each other on opposite inside end walls of the lamp, and maximize the diffusion of light from the LEDs. The lamp is a durable, portable, long light lighting solution for those who live off the electric power grid, victims of disaster, and the like. [0008] Preferred features of the invention are furthermore described and illustrated in the following detailed description of a preferred but not limiting embodiment of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIG. 1A is a perspective view of a solar powered lamp according to a preferred embodiment of the invention. [0010] FIG. 1B is a perspective view of the solar powered lamp of FIG. 1A from the bottom side. -3- [0011] FIG. 2 is an exploded view of the solar powered lamp of FIG. 1A. DETAILED DESCRIPTION OF THE INVENTION [0012] Referring to the embodiment of FIG. 1, collapsible housing 100 is made from a translucent, and preferably clear, plastic material such as polyvinylchloride (PVC), although the material used is not critical and another suitable translucent and flexible material, such as polyethylene, could be used. Housing 100 includes cylindrical side wall 14, flat circular top end wall 13, and flat circular bottom end wall 16. The flat end walls are sufficiently rigid to enable the lamp to form a free-standing cylinder when expanded. A handle 17, also preferably made out of the same flexible plastic material as the housing, permits the lamp to be attached easily to a wall or ceiling, or be to carried as the need arises. In the most preferred embodiments, a second handle 172 is provided on the opposite end wall 16, as shown in FIG. 1B. [0013] As shown in the exploded view of FIG. 2, top end wall 13 preferably includes an inner top 134 and outer top 132. Bottom end wall 16 includes inner bottom 162 and outer bottom 164. The inner and outer top (132, 134) are sealed to the side wall 14 and to each other to enclose top reflector 125 in water-tight fashion. It is generally preferable that the housing be sealed to an ingress protection level known as IP 67, which means protected against the ingress of dust and contaminants, and against the effects -4of temporary immersion in between 15 cm and 1 m of water for 30 minutes. Top reflector 125 has a reflective surface directly facing the LEDs 28 positioned on the bottom end wall and may be made out of PVC plated with a reflective coating, cardstock with a reflective coating, or other suitable material to provide stiffness to the housing end wall 13, and also to reflect light from the LEDs 28. [0014] A similar arrangement is provided on the bottom end wall 16, with bottom reflector 166 formed of a reflective-coated material. The bottom reflector is provided with apertures 44 positioned over the LED lights 28. Apertures 44 may be provided with a diffusive scrim material to close off the openings. [0015] LED lights 28 are in turn provided on a printed circuit board 200 on an end wall of the device. A rechargeable battery 40, adapted to power the LEDs, is provided on the printed circuit board 200 opposite a solar panel 202 (shown in FIG. 1B) adapted to recharge the rechargeable battery 40. The solar panel is exposed to the sunlight through the clear outer bottom 164 through an aperture in bottom frame 160. The printed circuit board is attached to bottom frame member 166 with double sided tape 220. [0016] A solar panel for use with the invention may be selected from those known in the art to be adapted to power a small LED array. A suitable -5solar panel is a polycrystalline 5V/130mA array with an open circuit voltage of 4.3 V, a short circuit current of about 3.5 A, and an optimum operating voltage of 2.6 V. Generally, when the solar panel is laid flat in direct sunlight, the rechargeable battery is completely charged in 4 to 8 hours, with sufficient charge to yield more than 6 hours of light and preferably more than 8 hours of light once fully charged. Although any number of LEDs may be used within the scope of the invention, 6 to 10 LEDs is preferable, and 8 is most preferred. The LEDs provide a 4000 mcd light source, sufficient to illuminate a 10 square foot area with usable lighting. In embodiments, multicolored LEDs may be used. Use of multicolor LEDs may be functional, such as red or yellow to indicate emergency condition, or decorative. [0017] The rechargeable battery 40 is preferably a lithium-ion polymer battery with a thin profile that can be readily incorporated onto a printed circuit board. In the most preferred embodiments, the rechargeable battery has a thickness of no more than about 5 mm, a standard capacity of 1000 mAh (which could be up to 200 mAh), and a nominal preferred operating voltage of 3.7 V (which could be lower). The illustrated planar array of LEDs consists of eight LEDs arranged in a circle and powered by the battery. In a preferred embodiment, each LED has a maximum operating current of 320 mA at 90 lumens (high power) and 220 mA at 70 lumens (low power). -6- [0018] The printed circuit board 200 controls the powering of the LEDs by the battery 40. A user activates a power switch 204 located on the exterior of the lamp to power the LEDs. In embodiments, the circuit board controls three levels of illumination: low power, high power and intermittent. The levels can be obtained by pressing the same power switch used to turn the device off and on. For example, the switch may be pressed once for low power, twice for high power, three times for intermittent, and four times to turn the device off. Sourcing a suitable such microchip for this purpose may be left to the skill of the ordinarily skilled artisan. [0019] The housing is collapsible and is preferably inflatable through a valve 123 through the top end wall 13. Apertures are provided in the top reflector and inner top into the interior of the housing so that the housing can be inflated, resulting in a low-cost, lightweight and durable lighting solution for those in need. [0020] The above description of the preferred embodiments is not to be deemed limiting of the invention, which is defined by the following claims. The foregoing description should provide the artisan of ordinary skill with sufficient information to practice variants of the embodiments described. Features and improvements described in connection with one embodiment may be -7combined with other embodiments without departing from the scope of the invention. -8 -

Claims (5)

1. An inflatable solar powered lamp, comprising: a collapsible, translucent housing having flat end walls and a side wall, each end wall including an outer end wall, an inner end wall and a panel between the outer and inner end wall; a valve for inflating the housing; a printed circuit board on one end wall comprising a planar array of light emitting diodes (LEDs); a reflective surface with apertures over the LEDs; a rechargeable battery attached to the printed circuit board powering the LEDs; a solar panel opposite the LEDs on the circuit board adapted to recharge the rechargeable battery; wherein the circuit board is operatively connected to the rechargeable battery, the LEDs, the solar panel and a switch for powering the LEDs on and off.

2. The solar powered lamp according to Claim 1, wherein the flat end walls have curved edges. -9 -

3. The solar powered lamp according to Claim 1 or 2, wherein the housing side wall is made of a translucent, polyvinylchloride material sealed to be water-tight.

4. The solar powered lamp according to Claim 1, 2 or 3, wherein the battery is a lithium ion polymer battery pack having a thickness less than 5 mm, a capacity of up to 2000 mAh and a nominal operating voltage of up to 3.7 V, and wherein the planar array of LEDs consists of up to ten LEDs, optionally arranged in a circle and powered by the battery, each LED having a maximum operating current of 320 mA at 90 lumens.

5. The solar powered lamp according to any one of Claims 1 to 4, further comprising one or two handles attached to one or both flat ends, as the case may be, at least one of said handles configured to provide a ceiling attachment for hanging the lamp. - 10 -