DESC:FIELD OF INVENTION

[001] The present invention relates to a rechargeable luminescent emergency lighting system and a method of preparation thereof. Particularly, the present invention relates to an emergency lighting system and more particularly Lighting Signage having high light intensity.

BACKGROUND OF THE INVENTION

[002] Standard Emergency Escape LEDs Lighting devices and Emergency Escape Way Finder / directional signages are incorporated with battery backup as alternative to electrical supply in case of normal power cutoff and in emergency of any Fire incidence. For the places, where the electric supply fails and the battery backup also fails, then the existing emergency lights do not work.

[003] The Photo luminescent signage systems as per International Standards DIN 67510, ASTME2072-4 known in the prior art are based on the photo-luminescent pigments that get charged from sun light or artificial light. As of now such devices signages are widely used in making fire safety glow in dark directional signage for emergency exits, or used in wrist watches, table alarm clock, wall clocks etc. Such substances also known as phosphors absorb ultraviolet or visible light from a distance and get excited to a high energy state and emit energy in the form or light or radiation when these substances return to their normal state. While a fluorescent substance stops glowing as soon as the radiation causing excitation is removed, the phosphors keep glowing for a relatively longer durations. The intensity of glow in these substances, however, is very low and for less duration.

[004] The exiting technology has the following drawbacks:
(a) Emergency Lighting & signage with battery backup – for the emergency lighting and Fire safety signage battery is placed as a backup to give the alternative power source to emit the lights in case of any emergency during power failure, in such case these devices become costly and have recurring cost and very high probability of drain or failure of the battery.
(b) Photo Luminescent Safety Signage – Currently, the Photo luminescent signage are made with photo luminescent film or vinyl or rigid sheets, however it has limitation that it gives only glowing effect, which can be seen from close distance only because of its low intensity. Further, the prior known signage produce only glowing effect and cannot produce enough light so as to make the surrounding objects visible. Thus, the available signage cannot be construed to be the alterative of any emergency battery backup lighting devices.

[005] In view of the above problems associated with the state of the art, there is a need of a rechargeable luminescent Emergency lighting systems having capability of getting charged via artificial light source (such as led, bulb, or tub) upon very close lighting exposure. Further it should be able to provide a strong glowing effect for longer durations even in the absence of power supply and is able to emit light having high intensity.

OBJECTIVES OF THE INVENTION

[006] The primary objective of the present invention is to provide an emergency lighting lighting device/system and its method of preparation.

[007] Another objective of the present invention is to provide a rechargeable luminescent emergency lighting system getting charged via artificial light source (such as led, bulb, or tub) upon very close lighting exposure.

[008] Yet another objective of the present invention is to provide a diffuser for rechargeable luminescent emergency lighting device/system having strong glowing effect for longer durations even after power cut-off when supercharged in close proximity to the artificial light source.

[009] Another objective of the present invention is to provide a lighting diffuser capable of being moulded in various shapes and sizes such as a shell/ extrusion profile / sheets / flex and other dimensions or shapes to develop wide range of illumination in dark lighting solutions products (for ex lighting products, down lighter, signage, etc.).

[0010] Yet another objective of the present invention is to provide a photoluminescence lighting diffuser formed by mixing a predetermined amount of photoluminescence pigment into normal plastic or by coating photoluminescence material on clear plastic sheets in certain ratio to make various type of photoluminescence lighting diffuser sheets or shell or extrusion profile.

[0011] Another objective of the present invention is to provide the photoluminescence lighting diffuser as an energy efficient material for different lighting products emitting high intensity light or dark lighting solutions to improvise their energy efficiency.

[0012] Other objectives and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein, by way of illustration and example, the aspects of the present invention are disclosed.

SUMMARY OF THE INVENTION

[0013] The present invention relates to a rechargeable luminescent emergency lighting device/system and a method of preparation thereof. The lighting device/system comprises of a translucent plastic diffuser to provide uniform lighting. The present invention particularly provides a photo luminescent diffuser. The present invention also provides a method of preparation of photo luminescent diffuser by incorporating the photo-luminescent pigment into translucent plastic. Such diffusers may be made in different shapes and sizes and placed in close proximity to the artificial light source. Photoluminescence pigment component in the diffuser component gets super charged in multiple X due to its very close lighting translucent exposure. As a result, numerous glow in dark lighting solutions made in the form of a range of products provides lighting for longer durations even without any electricity.

BRIEF DESCRIPTION OF DRAWINGS

[0014] A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when taken in conjunction with the detailed description thereof and in which:

[0015] Figure 1 illustrates a photoluminescence diffuser.

[0016] Figure 2 illustrates a photoluminescence diffuser with LED lighting source.

[0017] Figure 3 illustrates an example of photoluminescence diffuser product.

DETAILED DESCRIPTION OF THE INVENTION

[0018] The following detailed description and embodiments set forth herein below are merely exemplary out of the wide variety and arrangement of instructions which can be employed with the present invention. The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. All the features disclosed in this specification may be replaced by similar other or alternative features performing similar or same or equivalent purposes. Thus, unless expressly stated otherwise, they all are within the scope of the present invention.

[0019] Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0020] The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention.

[0021] It is to be understood that the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise.

[0022] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps, or components but does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof.

[0023] The present invention relates to a rechargeable luminescent emergency lighting system. Particularly, the present invention relates to a photo luminescent lighting diffuser and a method of preparation thereof. The photo luminescent lighting diffuser device/system may be charged either from artificial light source. Particularly, the photo-luminescent lighting diffuser device is a supercharging photoluminescence mixed translucent milky white plastic (lighting diffuser sheet/shell/extrusion profile). The said lighting diffuser sheet replace the normal plastic translucent diffuser sheet used in various LED Lighting products (i.e., LED Bulb, down lighter, LED Batten, outdoor Lighting Signage etc.) to provide long term glowing effect.

[0024] Figure 1 illustrates a photoluminescence diffuser 100. The upper part 110 is an artificial light source. In an embodiment, the artificial light source may include an array of plurality of Light Emitting Diodes (LEDs). The lower part 120 is a photo photoluminescence diffuser (diffuser sheet). Figure 2 illustrates a photoluminescence diffuser with LED lighting source. In a preferred embodiment, the diffuser sheet or shell or extrusion profile may be prepared by mixing photoluminescence pigment in certain ratio in available normal plastic component or sheet to obtain various types of lighting diffuser sheet or shell or extrusion profile. photoluminescence pigment component in the diffuser sheet is super charged in multiple X due to its very close lighting translucent exposure. The novel photoluminescence diffuser of the present invention provides light of higher intensity and glows as any other normal light or outdoor lighting products. Further, the diffuser keeps on emitting light when the light source is removed, or the power supply cuts off. The illumination of the diffuser sheet is of higher intensity even in the absence of the light source. The intensity remains stronger for at least 2-3 hours and thereafter it starts diminishing and the glow remains for some more time. The novel diffuser according to the present invention is very useful in illumination of public places, lifts, basement parking, tunnels, high rise building, offices, factories, Fire emergency, and light countdown in heavy rain, earthquake, or any type of emergency etc. The present invention may be implemented to manufacture or produce different types of photoluminescence diffuser products that may include LED bulbs for personal or industrial use. For example, Figure 3 illustrates an example of photoluminescence diffuser product.

[0025] The present invention also provides a process of preparation of the photo-luminescent diffuser. The lighting diffuser may be prepared by any one of the following processes:
(a) Coating Process,
(b) Sheet Casting Process,
(c) Extrusion Process, and
(d) Mold Cavity Dia Casting

[0026] (a) Coating Process: The coating process may be selected from any of the following processes:
(i) Silk Print Coating Process or
(ii) Anilox Cells Roller Coating Process.

[0027] Silk Print Coating Process – straight/flat Photoluminescence diffuser sheets are prepared by silk printing coating process and various products are prepared therefrom for example downlighter, 2x2 grid lights and all type of outdoor/indoor LED lighting signage. The silk print coating process comprises the following steps:
a) preparing Photoluminescence paste;
b) deeply cleaning the clear Acrylic / PVC / PP /HIPS sheets;
c) preparing the liquid Photoluminescence paste Coating by U shape squeeze rubber on 20 number silk mesh;
d) passing the sheet from IR Dryer and Hot air dryer conveyor belt;
e) collecting the sheet from corner and further dry it on racks in totally dust free chambers / environment for 8 hours;
f) cutting the photoluminescence diffuser sheet as per the required size; and
g) fixing the Photoluminescence diffuser sheet part in front of LED such that the photo luminescent coated side of the sheet should be facing the LED panel/modules.

[0028] Anilox Cells Roller Coating Process - straight / flat Photoluminescence diffuser sheets are prepared from Anilox Cell Roller coating process for preparing various applications for example downlighter, 2x2 grid lights, tiles & all type of outdoor/indoor LED lighting signage. The anilox cells roller coating process comprises the following steps:
a) preparing liquid Photoluminescence paste;
b) deeply cleaning the clear Acrylic / PVC / PP /HIPS sheets;
c) preparing the liquid Photo luminescent Paste Coating by Anilox Cell Roller coating production line for 24-36 micron thickness;
d) passing the sheet from IR Dryer and Hot air dryer conveyor belt;
e) collecting the Sheet from corner and further drying it on racks in totally dust free chambers / environment for 8 hr;
f) cutting the photoluminescence diffuser sheet as per the required size; and
g) fixing the Photoluminescence diffuser sheet part in front of LED such that the photo luminescent coated side of the sheet should be facing the LED panel/modules.

[0029] (b) Sheet Casting Process: a photoluminescence diffuser sheet by casting process is ideal for large Lighting diffusers wherein some type of bending or shape is required by post heat bending process or by thermoforming process. The sheet casting process comprises the following steps:
a) preparing liquid mixer of MMA (methyl methacrylate monomer ) with photoluminescence pigment;
b) sealing all four-side border with small liquid fitting space in center of toughened Glass;
c) fixing well/sandwich other glass to make cavity for required thickness;
d) pouring the liquid mix in Fix well/sandwich cavity of glass;
e) boiling the casted mold followed by high temperature steam chamber;
f) preparing natural Dry from 6-8 hr;
g) bending or shaping as per the desired Lighting Diffuser by post heat bending process or by thermoforming process;
h) fixing the Photoluminescence diffuser sheet part in front of LED such that the photo luminescent coated side of the sheet should be facing the LED panel/modules.

[0030] (c) Extrusion Process: Photoluminescence Diffuser profile by extrusion process can be prepared. The major Photo luminescent Diffuser profile application can be for LED Tube Light / battens, aluminum profiles LED lighting solutions.
a) preparing the desired profile shape Die as per Extrusion machine;
b) preparing the mix batch of Photoluminescence master batch with PP or PVC, PC granules;
c) pouring the mixture in Extrusion hooper;
d) cutting the extruded photoluminescence diffuser profile as per required length; and
e) fixing the Photoluminescence diffuser profile in assembly of LED Tube Light / battens, aluminum profiles LED lighting solutions.

[0031] (d) Mold Cavity Dia Casting – a Mold Die Casted Photoluminescence diffuser shell is prepared for making LED Bulbs, lamp, Lantern or any small size lighting products.
a) preparing the desired shape Die for molding;
b) preparing the Mix batch of Photoluminescence master batch with PP or PVC, PC granules;
c) pouring the mixture in molding machine hooper; and
d) fixing the Photoluminescence diffuser shell in assembly of LED bulb/lamp/lantern etc.

[0032] In an embodiment, the photo luminescent pigment is selected from the commercially available pigments. The photo luminescent pigment may be a strontium aluminate based pigment. However, any long lasting photo luminescent pigment may be used for the present invention.

[0033] In an embodiment, the photo luminescent pigment paste is prepared by adding the organic/inorganic solvent depending on the choice of the pigment.

[0034] The advantages of the system of the present invention are discussed herein:
• In case the electrical supply fails or if the electrical supply is not available, diffuser would supply light without any charging (either through power supply or battery) requirement.
• The diffuser provides at least 1 to 3 hour independent light supply even without the power supply and therefore are energy efficient.
• The diffuser gets charged via artificial light source (such as but not limited to LED, bulb, or tub) upon very close lighting exposure and provides strong glowing effect for longer durations after power cut-off which is non-conventional Lighting source.
• The diffuser capable of being molded in various shapes and sizes such as but not limited to a shell/ extrusion profile / sheets / flex and other dimensions or shapes to develop big range of Glow in Dark Lighting Solutions products. The various glow in dark lighting solutions products can be Emergency Egress Lighting Signage, LED Bulb, Down lighter, LED Batten, Zero volt night lamp, Outdoor Advertising Lighting Signage, Night clubs disco party lights and the like.
• The glow in dark lighting products prepared according to the present invention can be directly charged by on grid solar power system through charging the photo luminescent diffuser in day time by Led lighting devices and can emit in nights for few hours even the sunset without battery storage system or on off grid solar system.

[0035] While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.
,CLAIMS:WE CLAIM:

1. A system for rechargeable luminescent emergency lighting comprising:
a light emitting source configured to emit light when connected to a power source;
a diffuser sheet with a photoluminescence pigment material comprises:
• a first surface exposed to receive light from the light emitting source and
• a second surface is configured to distribute light from the light emitting source to open environment, a the second source is further configured to provide illumination when the light emitting source is not connected to a power source.

2. The system as claimed in claim 1, wherein the light emitting source comprises one or more Light Emitting Diodes (LED).

3. The system as claimed in claim 1, wherein the diffuser sheet is a moldable plastic sheet including Acrylic polymer, Polyvinyl Chloride (PVC), Polypropylene (PP), High Impact Polystyrene (HIPS) diffused with a photoluminescence pigment material and the photoluminescence pigment material is a strontium aluminate based pigment.

4. A method for producing a photo-luminescent diffuser sheet for rechargeable luminescent emergency lighting system by coating process, comprising the steps of:
cleaning the diffuser sheet and applying a photoluminescence pigment material a first side of the diffuser sheet;
curing the diffuser sheet with photoluminescence pigment material through an thermal dryer on a conveyor belt; and
drying the photo-luminescent diffuser sheet in a dust free environment.

5. The method as claimed in claim 5, wherein the photo-luminescent diffuser sheet for rechargeable luminescent emergency lighting system is placed in the dust free environment for at least 8 hours.

6. A method for producing a photo-luminescent diffuser sheet for rechargeable luminescent emergency lighting system by casting process, comprising the steps of:
preparing a composition of a monomer and a photoluminescence pigment material;
pouring the composition in a casted mold having a cavity;
boiling the casted mold and further providing heat in a high temperature steam chamber;
drying the casted mold in a dry environment; and
providing heat to allow bending of the to the photo-luminescent diffuser sheet in a desired shape.

7. The method as claimed in claim 7, wherein the casted mold is allowed to dry for at least 6 to 8 hours.

8. A method for producing a photoluminescence diffuser profile for rechargeable luminescent emergency lighting system by extrusion process, comprising the steps of:
preparing a die of desired shape;
preparing a mixture of a photoluminescence pigment material and granules of polymer;
pouring the mixture in an extrusion hooper; and
cutting the extruded photoluminescence diffuser profile as per required length.
9. The method as claimed in claim 4 & 6, wherein the diffuser sheet is a moldable plastic sheet including Acrylic polymer, Polyvinyl Chloride (PVC), Polypropylene (PP), High Impact Polystyrene (HIPS), the photoluminescence pigment material is a strontium aluminate based pigment.