Patent Publication Number: US-2003223247-A1

Title: Illumination device

Description:
[0001] This invention relates to illumination arrangements for use as a safety or decorative lighting.  
       [0002] There are many needs for illumination devices in the field of safety and decoration. However, typically unique devices have been devised for each application. For example, roadside warning devices typically comprise lights coupled to automotive systems for providing illumination for emergency repair, roadside warning lamps, flashlight type devices which may include colored lens for warning and safety purposes and so on.  
       [0003] Other differently configured arrangements are provided pedestrians during walking or jogging at night. Mostly, however, pedestrians use reflectors rather than illuminators which tend to be either too bulky for such use or too low an intensity to be useful. Steady state and flashing light devices also are provided, but in many diverse different configurations.  
       [0004] Traffic officers also use illumination devices which differ from the above devices in still different configurations.  
       [0005] Further, objects carried in vehicles sometimes may be too large for the trunk and a need is seen for providing an illumination device for such objects. Present illumination devices may or may not be readily adapted for such use depending upon the object configuration. Many other special applications for illumination devices are in need of practical convenient devices which are not always commercially available such as children scooters and bicycles, automotive hood, trunk and interior lighting, personal lighting devices, convenient, but highly visible devices for pedestrians, mood lighting devices, camping needs and so on.  
       [0006] A need is seen for a convenient bright to low light level lighting device that is easily adapted for all of the above uses and others without significant modification. A versatile lighting device that is useful in many different applications is presently believed unavailable commercially. The present invention is directed to providing a solution to this problem. A need is seen for a simple battery operated device that is portable and adaptable for personal safety or decorative applications with bright illumination as well as white or colored light. A single device that is versatile resolves the need for keeping a wide variety of illuminating devices on hand.  
       [0007] Some commercially available devices are not readily adaptable for many different possible needs, creating a void even though some such devices are at hand. For example, the common flashlight is used for many purposes, but it does not always serve the user in the best way. A flashlight might be used by pedestrians, but such devices provide focussed beams and may not always be seen by motorists. Specialty lights are available for bicycles and the like, but these too provide focussed beams not always visible to others. Also they may not be useful with other types of arrangements such as scooters, boats, bicycles or motorize vehicles and so on because of specific brackets provided for specific applications.  
       [0008] An illumination device according to an aspect of the present invention comprises a source of illumination and a solid elongated optical illumination transmitting element having a length defining a longitudinal axis between first and second ends, the element having a peripheral surface along the length between the ends, the element being coupled to the source such that the element conducts the illumination along the axis. A member is attached to a portion of the peripheral surface for causing the element to transmit illumination from the conducted illumination in an outward radial direction through the peripheral surface along the length between the ends. An electrical circuit illuminates the source of illumination.  
       [0009] Since the device is elongated and can be battery operated, it is portable and can be provided with colored light as well as steady state or flashing light as needed. The light by radiating outwardly from an elongated element provides broad radiation in different directions as compared to focussed beams provided by flashlights. This kind of device is readily seen at night from many directions and by providing a source of light of a given color and intensity it can be used for safety as well as decorative or mood purposes.  
       [0010] In one aspect, the member is arranged for providing enhanced reflection of the illumination in the radial direction. Preferably, the member is white. And more preferably, the member is a tape with an adhesive coating for adhering the member to the optical element.  
       [0011] In a further aspect, the element is optically transparent acrylic plastic and preferably is an optically transparent acrylic plastic rod having a given transverse geometric shape which in one aspect the rod is cylindrical and preferably the rod is circular cylindrical. More preferably, the rod has a half round shape in transverse section forming a semi-circular cylindrical peripheral surface and a planar peripheral surface on a side opposite the semi-circular cylindrical surface.  
       [0012] In a further aspect, an illumination reflecting member is attached to the planar surface and in a further aspect, the reflecting member is white tape.  
       [0013] In a further aspect, the element is a rod with a peripheral surface and the member is an illumination reflecting tape on a portion of the peripheral surface.  
       [0014] In a still further aspect, the device further includes a housing for securing the source, element and attached member and circuit thereto. Preferably, the housing has a window for permitting the transmission of the illumination in the outward radial direction.  
       [0015] In a further aspect the device includes attachment means for attaching the housing to an object and preferably, the attachment means is at least one strap.  
       [0016] In another aspect, the attachment means includes hook and loop fastening arrangements or an adhesive means for adheringly attaching the housing to the object.  
       [0017] In a still further aspect, the circuit includes means for causing the illumination to oscillate on and off.  
       [0018] In a further aspect, the element has at least one bore in each end arranged to receive the illumination source therein. Preferably, the illumination source is an LED (light emitting diode). Still other aspects are described in the following description. 
     
    
    
     IN THE DRAWING  
     [0019]FIG. 1 is an isometric view of an illumination device according to an embodiment of the present invention;  
     [0020]FIG. 2 is an isometric exploded view of the device of the embodiment of FIG. 1;  
     [0021]FIG. 3 is an isometric view of the optical illumination element of the device of FIGS. 1 and 2;  
     [0022]FIG. 4 is a side elevation view of the device of FIG. 1;  
     [0023]FIG. 5 is a top plan view of the device of FIG. 1;  
     [0024]FIG. 6 is a bottom plan view of the device of FIG. 1;  
     [0025]FIG. 7 is a sectional elevation view of the embodiment of FIG. 5 taken at lines  7 - 7 ;  
     [0026]FIG. 8 is a side elevation view of a representative LED used in the device of FIG. 1;  
     [0027]FIG. 8 a  is a top plan view of the LED of FIG. 8;  
     [0028]FIG. 9 is a fragmented side elevation sectional view of the LED end portion of the light transmitting element of the embodiment of FIG. 1;  
     [0029]FIG. 10 is a top plan view of a printed circuit board assembly used in the device according to the embodiment of FIGS. 1 and 2;  
     [0030]FIGS. 11 and 12 are circuit diagrams useful with the devices of the embodiments of FIGS. 1 and 2; and  
     [0031]FIGS. 13 a ,  13   b  and  13   c  are end elevation views of different geometric shaped illumination transmitting elements according to the present invention wherein FIG. 13 b  is an end elevation view of the element of the embodiments of FIGS. 1 and 2 and wherein the FIG. 13 c  element is used with a single LED at each end and the elements of FIGS. 13 a  and  13   b  are used with dual LEDs at each end. 
    
    
     [0032] In FIG. 1, illumination device  2  comprises a housing  4  and an illumination transmitting element  6 . The element  6  is radially exposed to the ambient atmosphere through window  8  of the housing. Window  8  is an opening with no cover. The housing  4  comprises two mating halves  10  and  12 . The housing halves  10  and  12  are preferably injection molded thermoplastic material. The housing  4  is overall generally circular cylindrical in this embodiment but could be other geometric shapes as desired, e. g., square or rectangular in end view or polygon of any number of sides as desired.  
     [0033] In FIGS. 3 and 13 b , element  6  preferably comprises a half round opticallly transparent acrylic plastic rod having a circular semi-cylindrical convex surface  14  on one half surface of the rod and a planar surface  16  on the opposite side of the rod. Preferably, the rod is eight inches long in one embodiment, but may have other lengths to suit a given need. The rod surface  14  has a one inch (25.4 mm) diameter so that the distance d represents the diameter. The element  6  has planar end surfaces  18  and  20  at opposite first and second ends.  
     [0034] A pair of like spaced circular cylindrical bores  22  are formed in each end surface  18  and  20  normal to the end surface. The bores in this embodiment are preferably about 0.5 inches (13 mm) apart and about 0.08 inches (2 mm) from the surfaces  14  and  16 . The bores may be about 0.200 inches (5 mm) in diameter and about 0.356 inches (9 mm) deep. The bores should be smooth with no roughness so as to be optically clear into the element core from the bore surface to maximize light transmission therethrough. The bores  22  should be parallel to each other and to the longitudinal axis  24  of the element  6  and device  2 .  
     [0035] A preferably white tape strip  34 , FIG. 3, which may be opaque, is bonded to the flat surface  16  of the element  6 . The tape strip  34  acts as a reflector, and scatters incident axially transmitted illumination radiation along the element longitudinal axis in the radial directions  36  from the element  6 . The tape is made of paper and has one side coated with an adhesive. The other side is white and somewhat reflective. This side also is somewhat rough so as to scatter incident light such as the axial transmitted light in the element  6 . The tape in one form is available as PF14 Flat Back Premium from Intertape Company. The strip may be other colors, but it is believed that white reflects and scatters the maximum amount of illumination radially. Normally, the substantially all of the Illumination from the LEDs is transmitted by the element axially in direction  38  parallel to axis  24 . Relatively little radiation is emitted normal to the axis  24 . However, the strip  34  reflects and scatters the photons radially out of the element through the convex peripheral surface  14  with a minimum of loss (illumination remaining axially trapped in the element  6 ).  
     [0036] Using what is referred to as Super Bright LEDs from Sunled Corporation, a relatively bright light is radiated outwardly in the radial directions  36  providing good illumination for a variety of purposes as will be explained below. The amount of light radiated is a function of both the surface area of the element  6 , which due to its axial length, provides the desired amount of radiated light and the intensity of the LEDs. These are available at different intensity levels and colors as described below. The light is clear and bright and may be provided in different colors to suit a given application, e.g., red for warning, white for illuminations and other colors for decorative or mood lighting. Also, different colored LEDs may be provided coupled to a single element to provide different color hues not otherwise available in individual LEDs. Preferably, two LEDs at each element  6  end provides a bright light suitable for most purposes.  
     [0037] An LED (light emitting diode)  26  is inserted in each bore. The LED  26  has an illuminating portion  28  and a pair of electrical leads  30 . The portion  28  is inserted into the corresponding bore  22  of the element  6 , FIG. 3. The LEDs are commercially available, for example, from Sunled Corporation of Walnut, Calif. They preferably are 5 mm round with a flat on one side as shown in FIG. 8 a.    
     [0038] They are available as Super Bright lamps with maximum ratings of a reverse voltage V R  of about 5 volts, a forward current I F  of about 30 mA, a forward peak current I FP {fraction (1/10)} duty cycle of 0.1 ms pulse width of 160 mA, power P O  dissipation of 105 mW. The operating characteristics are typical forward voltage V F  (I F =20 mA) of 3.5 volts, a forward max voltage V F  of 4.0 volts and a reverse current (V R =5 volts) I R  of 10 uA. They have a luminous intensity of 2200 to 3100 mcd.  
     [0039] The LEDs are available from Sunled Corporation under catalog designation LCW53WD color white. The emitting material is GaN. Other LEDs are available under Sunled catalog designations LMY53x yellow color with intensity mcd of 100-500 diffused to 700-2500 water clear, LCB53WD blue GaN material 1200-3000 mcd intensity water clear, LCB12WD blue GaN material 120-2100 mcd, LBG53WE green InGaN material water clear with mcd 2800 to 4500. Still other LEDs are available with other characteristics according to a given need.  
     [0040] The device  2 , FIG. 2, includes, in addition to the housing halves  10  and  12  and element  6 , a printed circuit assembly  32  which includes a printed circuit board  40 , FIG. 10. The board  40  includes the components of either of FIGS. 11 and 12. The element  6  with the strip  34  attached by bonding by an adhesive coating on one surface of the strip is attached to the printed circuit board  40  by clamping the element between the printed circuit board  40  and the upper housing half  10 , FIG. 1. The board  40  and element  6  are clamped together by the housing  4 . The strip  34  has a single side adhesive for attachment to the element  6 . The surface of the strip  34  and adhesive coating together provide the optical qualities necessary to reflect the illumination in the radial directions  36 , FIG. 3. The strip, as noted above, may be obtained from Intertape company.  
     [0041] The circuit assembly  32  includes all of the electrical components to operate the device  2 . Such components will be described below in connection with the circuit diagrams of FIGS. 11 and 12.  
     [0042] The device  2 , FIG. 2, also includes a conventional 9 volt battery  42 . The battery  42  is connected to the circuitry by a conventional connector and strap arrangement  43 . The lower housing half  12  has a compartment  44  for the battery and enclosed by a cover  46 . The two housing halves  10  and  12  are attached by screws  48 . The two halves together form a generally cylindrical housing. The bottom half  12  is generally frusto-semi-circular cylindrical with a flattened surface  56  for mounting on a flat surface. The top half  10  has semi-cylindrical portions  10 ′ and  10 ″ spaced by the window  8 . The housing halves  10  and  12  have mating flanges  50  and  52 , respectively at one housing end.  
     [0043] The upper and lower housing halves  10  and  12  also have mating peripheral flanges  58  which surround the housing  4  on three sides. The flanges  58  have mating slots  64 . Two straps  66  and  68 , FIG. 1, carry hook and loop fasteners, such as Velcro fasteners, and pass through and are attached to the housing  4  via the slots  64 . The straps  66  and  68  attach the device  2  to bars and rods such as found on scooter and bicycle frames and so on, for example. The hook and loops enable one strap end to fasten to the other strap end in a known manner.  
     [0044] The housing halves also have stanchions  70 , FIG. 2, for receiving the various screws  48 . Overall, the housing  4  appears as an elongated wand with the illuminating element  6  exposed through the window  8 . The window  8  may optionally be enclosed by a clear plastic cover (not shown). The battery  42  end of the housing  4  has flat end surfaces  62 ,  62 ′, FIGS. 1 and 2.  
     [0045] In FIG. 11, the operating circuit  72  comprises the 9 volt battery  42  having its positive terminal connected to series connected LEDs L 1  and L 3  through resistor R 3 . The LEDs are connected to ground via FET transistor M 1  collector and emitter terminals  76  and  78 . The junction between resistor R 3  and the battery  42  is connected to operate inverting amplifier A 1  of Schmitt trigger circuit  82  which provides an oscillating signal to the control electrode  75  of transistor M 1 . Circuit  82  comprises three series connected inverting amplifiers A 1 , A 2  and A 3  of an integrated circuit chip supplied as part number CD 40106 BCM of Motorola and available from distributors DigiKey or FAI. The output of the circuit  82  amplifier A 1  is supplied to the common terminal connected to wiper  84  of switch S 1  and to the control electrode of transistor M 1 . Switch S 1  has three terminals  80 ,  81  and  85  which are selectively connected to the common terminal of wiper  84 . Terminals  80  and  81  are respectively coupled to the input of amplifier A 3  through respective resistors R 1  and R 2  and to ground through capacitor C. Terminal  85  is open to turn the circuit off.  
     [0046] Resistor R 1  may have a value of 2 K ohms, resistor R 2  may have a value of 200 K ohms, and resistor R 3  may have a value of 36 ohms {fraction (1/4 )} watt. Capacitor C may have a value of 1 uF, 10 V min.  
     [0047] In operation, with the switch S 1  in the position shown, resistor R 2  is in circuit, the transistor M 1  is conductive via the collector-emitter path lighting the LEDs L 1  and L 3  so as to appear to be a steady state continuous mode light. When the switch S 1  is switched to place the resistor R 1  in circuit, the transistor M 1  remains conductive and the LEDs L 1  and L 3  light intermittently in a flashing mode. The LEDs are turned off when the wiper  84  is switched to terminal  85 . The switch S 1  is operated externally the housing  4 , FIG. 1.  
     [0048] The circuit  86  of FIG. 12 is substantially identical to the circuit  82  of FIG. 11 and has the same value components as the circuit of FIG. 11 except for resistor R 1  which has a value of about  75  ohms, and which components are connected in the same fashion. A further exception is that the circuit  86  has four LEDs L 1 , L 2 , L 3  and L 4  in circuit as compared to the two LEDs of the circuit  82 . LED L 1  and L 3  are series connected as in the prior circuit, but that series connection is connected in parallel with the series connection of LEDs L 2  and L 4  in this circuit. This parallel network of LEDs, which all preferably have the same electrical characteristics and the same color or, in the alternative, different colors as desired, is connected between resistor R 3  and the transistor M 1  collector terminal. All other components of the two circuits are the same as well as their connections. The LED  1  and LED  2  are at one end of the element  6  and the LED  3  and LED  4  are at the other opposite end of the element  6 . The circuit  86  is shown with the wiper  84  connected to resistor R 2  in the steady state continuously lit mode of the LEDs. When switched to connect R 1  in circuit, the LEDs flash on and off in the intermittent flashing mode. The frequency of the flashes may be set by using components of selected values in a known manner. Different component values may be provided in the circuit in parallel with switches (not shown) for varying the flashing frequency. Connecting switch S 1  wiper  84  to terminal  85  shuts the LEDs off.  
     [0049] The light from the LEDs normally transmits axially in the optical element  6  of the devices with negligible transmission radially. The light impinges on the member  34  white or off white somewhat reflective surface and is scattered and reflected generally away from the optical axis  24  radially outwardly from the element  6  through the element outer surface. The light is scattered in about a 180° arc and provides bright illumination in such directions. Such non-focussed light is visible to a much greater degree than focussed light such as in flash lights or light devices that use parabolic reflectors and the like.  
     [0050] The straps  66 , FIG. 2, permit the device  2  to be attached to scooters, bicycles, wheelchairs, a persons clothing such as belts and the like and numerous other objects about which the straps can be wrapped or to which Velcro type fasteners can be secured. For example, the straps can be attached to other hook and loop devices that are commercially available and easily attached to, e.g., with adhesives as provided on such hook and loop materials as commercially provided, many different objects such as clothing, automobile interiors, and trunk and hood interiors, pedestrian clothing, auto exteriors for roadside warning, marker lights for bulky items carried on vehicles at night, camping and directional indicators for help applications, dental, hospital and other locations for mood lighting, boating indicators, hazard warning lighting and so on. The element  6  may preferably be about eight inches long, but may be other lengths depending upon a given implementation. The light given off is bright and can be colorful for providing visibility and immediate recognition at night in many directions. While batteries are provided, the circuitry may also be connected to power adapter transformers if desired for more permanent installations. For example, the lights may be used as stair and side walk markers or lawn decorative lighting as desired, attached to trees or any other use where light is required. The devices  2  are flexible in utility and in colors employed, yet are inexpensive to operate and maintain while providing long life.  
     [0051] It will occur to one of ordinary skill that various modifications may be made to the disclosed embodiments which are given by way of illustration and not limitation as described above by way of example. It is intended that the scope of the invention is as defined by the appended claims.