Abstract:
A light emitting device for simulating neon light and method for doing the same. The light emitting device includes an elongated container having a combination of fluorescent pigment and phosphorescent pigment embedded therein. The light emitting device further includes a plurality of light emitting diodes aligned within the container. Finally, the light emitting device includes electrical means for providing electricity to the plurality of diodes.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention relates in general to lighting equipment. More particularly, this invention relates to a device and method that combine light emitting diodes (LEDs) with fluorescent and phosphorescent pigment to simulate neon light.  
         [0003]     2. Description of the Related Art  
         [0004]     Neon lights have been used for numerous years. They are made of long, narrow glass tubes and come in a variety of shapes. The tube of a neon light can spell out a word, for example.  
         [0005]     Inside the glass tube of a neon light, there is a gas such as neon, argon or krypton at low pressure. Both ends of the tube have metal electrodes. When a high voltage is applied to the electrodes, the neon gas ionizes, and electrons flow through the gas. These electrons excite the neon atoms and cause them to emit visible light. Neon emits red light when energized in this way. Other gases emit colors such as blue, green, yellow and white when energized.  
         [0006]     Neon lights are typically used in commercial applications such as advertising signs, information displays and backlights. They are generally chosen for their neon affect, or soft glow that demands the viewer&#39;s attention.  
         [0007]     Neon lights have numerous drawbacks. They are fragile, high voltage, and high energy devices. Neon lights are also monochromatic and do not have an after glow when electrical power is removed. In addition, they have inconsistent life patterns and require licensed tradesmen for installation and replacement.  
         [0008]     Therefore, the need arises for a lighting device that produces the attention demanding impact of neon but avoids the drawbacks associated with neon lighting.  
         [0009]     In U.S. Pat. No. 6,361,186, Slayden simulates neon light by using light emitting diodes as a light source and a milky clear polyethylene as a diffuser of the light. However, Slayden does not use fluorescent and phosphorescent pigment in the diffuser. The subject invention exposes a tube containing fluorescent and phosphorescent pigment to ultraviolet LEDs to simulate the soft glow of neon light.  
       SUMMARY OF THE INVENTION  
       [0010]     Accordingly, one object of the present invention is to provide a light emitting device that simulates neon light.  
         [0011]     A second object of the invention is to provide a light emitting device that is durable, low voltage and energy efficient.  
         [0012]     A third object of the invention is to provide a light emitting device that is chromatically versatile and continues to glow when electrical power is removed.  
         [0013]     A fourth object of the invention is to provide a light emitting device that has a long life, and is easy to install and maintain.  
         [0014]     To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a light emitting device for simulating neon light and method for doing the same. The light emitting device includes an elongated container having a combination of fluorescent pigment and phosphorescent pigment embedded therein. The light emitting device further includes a plurality of light emitting diodes aligned within the container. Finally, the light emitting device includes electrical means for providing electricity to the plurality of diodes.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a perspective view of a tube used in accordance with the present invention.  
         [0016]      FIG. 2  is a perspective view of a circuit board with LEDs used in accordance with the present invention.  
         [0017]      FIG. 3  is a perspective view of a preferred embodiment of the present invention.  
         [0018]      FIG. 4  is a cross-sectional view of a preferred embodiment of the present invention.  
         [0019]      FIG. 5  is a side view of the LEDs&#39; positions relative to the tube in a preferred embodiment of the present invention.  
         [0020]      FIG. 6  is a side view of the LEDs&#39; positions relative to the tube in an alternative embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     Referring now to  FIG. 1 , a perspective view of a tube used in accordance with the present invention is shown. Tube  10  is comprised of a clear carrier mix such as plastic or another similar material. The cross-section of tube  10  can be formed in different shapes, including round, oval, square, rectangle, hexagon and octagon. Tube  10  can also assume different shapes longitudinally, for example, to spell a word. Tube  10  has fluorescent and phosphorescent pigments embedded within it.  
         [0022]     Fluorescent pigment is a material made from metallic oxide with rare earth additives. Fluorescent pigment has the property of absorbing ultra-violet light of 360 nm wavelength and immediately emitting visible light. Fluorescent pigment comes in many colors. The pigment can be cast molded, ejection molded, or extrusion molded with different pigment volume to achieve different colors and intensities of color.  
         [0023]     Phosphorescent pigment is a powder that continues to radiate visible light after being energized. Electrons of phosphorescent pigment that orbit atoms or molecules absorb energy through collision with photons during excitation. Excess energy is emitted as photons of visible light at a later time. This phosphorescent pigment can be cast, extrusion or ejection molded into tube  10 .  
         [0024]     Summarizing  FIG. 1 , tube  10  can be formed into different shapes because it is comprised of plastic or another similar material. Tube  10  is also durable and does not shatter easily. In addition, the fluorescent pigment radiates visible light while tube  10  is energized by an ultraviolet light source. Finally, the phosphorescent pigment allows for continued display of visible light even when ultraviolet light is no longer provided to tube  10 .  
         [0025]     With reference to  FIG. 2 , a perspective view of a circuit board  20  with LEDs  22  used in accordance with the present invention is shown. Circuit board  20  includes a substrate  21  with circuit pads  23 . LEDs  22  are small light bulbs that fit easily into circuit pads  23 . Circuit board  20  is shaped to fit within tube  10 , and may be formed as a flexible strip. Energy is provided to circuit board  20  via connection points  24 .  
         [0026]     Unlike ordinary incandescent bulbs, LEDs  22  do not have a filament that will burn out, and do not get especially hot. LEDs  22  are illuminated solely by the movement of electrons in a semiconductor material, and last just as long as a standard transistor. In addition to having long life, LEDs  22  are energy-efficient and low voltage devices.  
         [0027]     Still referring to  FIG. 2 , LEDs  22  emit ultraviolet light. Although solid state devices can emit different colors of light, ultraviolet light has a wavelength best suited for energizing fluorescent and phosphorescent pigments in accordance with the present invention.  
         [0028]     Referring now to  FIG. 3 , a perspective view of a preferred embodiment of the present invention is shown. In the preferred embodiment, circuit board  20  is positioned within tube  10  to create a light emitting device that simulates the soft glow of neon light. The use of plastic or another similar material for tube  10  allows tube  10  to be formed in different shapes and to securely contain circuit board  20 . In addition, a soft clear silicone or solid urethane (not pictured) may be used to fill tube  10 . The inner fill holds circuit board  20  for display purposes and when tube  10  is being shaped. The use of solid state circuitry as the light source facilitates installation and maintenance of the light emitting device.  
         [0029]     When power is supplied to circuit board  20  via connection points  24 , LEDs  22  emit ultraviolet light that energizes tube  10 . Because the fluorescent and phosphorescent pigments emit visible light when energized, tube  10  will glow brightly, giving off the affect of neon. When the power is turned off, the phosphorescent pigment provides for continued glowing of tube  10 .  
         [0030]     With reference to  FIG. 4 , a cross-sectional view of a preferred embodiment of the present invention is shown. In this embodiment, the cross-sectional shape is circular. However, the cross-section may be oval, square, rectangular, hexagonal, octagonal, etc.  
         [0031]     Tube  10  has multiple layers  40 ,  41  and  42  and is comprised of a clear carrier mix such as plastic or another similar material. Different ratios of fluorescence and phosphorescence within layers  40 ,  41  and  42  are used to produce different colors and intensities within the visible spectrum of light. In one embodiment, the layers alternate between having fluorescent pigment and phosphorescent pigment.  
         [0032]     In the preferred embodiment, tube  10  consists of multiple layers  40 ,  41  and  42 . In an alternative embodiment, tube  10  consists of a single layer with the fluorescent and phosphorescent pigment combining to form a single layer tube.  
         [0033]     When power is supplied to connection points  24  and through LEDs  22  to produce ultraviolet light, the fluorescent and phosphorescent pigments are excited, and tube  10  emits the desired color and intensity of light. When power is no longer supplied to connection points  24 , the phosphorescent pigment still continues to emit light.  
         [0034]     Referring now to  FIG. 5 , a side view of the LEDs&#39; positions relative to the tube in a preferred embodiment of the present invention is shown. In this embodiment, LEDs  22  emit light at a projection angle of 120°. LEDs  22  are spaced apart from each other so as to minimize overlap of ultraviolet light. The distance between substrate  21  and the top of tube  10  is approximately ¾″. This configuration of LEDs  22  and tube  10  minimizes energy use, allows for uniform lighting of tube  10  and produces the soft glow of neon light.  
         [0035]     With reference to  FIG. 6 , a side view of the LEDs&#39; positions relative to the tube in an alternative embodiment of the present invention is shown. In this embodiment, LEDs  22  emit light at a projection angle of 160°. LEDs  22  are spaced apart from each other so as to minimize overlap of ultraviolet light. The distance between substrate  21  and the top of tube  10  is approximately ½″. This configuration of LEDs  22  and tube  10  minimizes energy use, allows for uniform lighting of tube  10  and produces the soft glow of neon light.  
         [0036]     Other embodiments of the invention will appear to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples to be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.