BACKGROUND OF THE INVENTION [0002] CCFLs are known for their advantageous properties of low power and low temperature. Conventional CCFLs are formed as elongated linear light sources. In some embodiments, the configuration can be U shaped, circular or serpentine ("w"shaped). These CCFLs have been employed in devices such as back lights for LCD panels found in lap top computers or LCD monitors.

[0003] In these conventional usages, the goal has been uniform illumination over a predetermined square or rectangular area and the conventional CCFL designs have accomplished the goal in a straight forward fashion. However, these devices do not adequately concentrate illumination in a limited area such as is provided by certain incandescent or regular fluorescent illuminating devices.

[0004] There is a need for an illuminating device that provides concentrated illumination over a limited area while offering the advantageous low power and low temperature properties of a CCFL.

SUMMARY OF THE INVENTION [0005] According to a preferred embodiment of the present invention, a CCFL is wound in a conical spiral such that the light from each coil is minimally obstructed by an overlying coil. In the preferred embodiment, the base of the cone rests on a base member to provide an illuminating device that that is adapted to connect to a source of power.

[0006] In alternative embodiments, a reflector may be incorporated in the base member so that light that is directed toward the base of the cone is

returned and combined with the illumination that is normally directed toward the apex. Yet other embodiments could employ a parabolic reflector which can collect all back scattered light to redirect to an outward direction.

[0007] In yet another embodiment, the apex of the cone is adjacent to the base member. This configuration more closely resembles the standard reflector (PAR) bulb and could be adapted to fit into existing conical receptacles. A coaxial conical, reflector could be added to both further concentrate the light and to protect the fragile CCFL device.

[0008] In yet another embodiment, the CCFL device can be formed into a flat, wound spiral so that the lamp is essentially flat. A reflector could be placed on the base member to redirect all back scattered light toward the area of interest.

[0009] It is also possible to provide a CCFL that is wound in a helix with a plurality of coils. Since the amount of light generated is a function of length of the CCFL, it is contemplated that more than four coils would be required to assure adequate illumination.

[0010] In yet other embodiments, more than one conical spiral CCFL can be mounted coaxially to increase the illuminating power available from a limited area. Using coaxial conical spirals, virtually the entire area could be a light source. These lamp units can be provided with pin contacts or with screw in plug contacts to work in available incandescent sockets.

[0011] The novel features which are characteristic of the invention, both as to structure and method of operation thereof, together with further objects and advantages thereof, will be understood from the following description, considered in connection with the accompanying drawings, in which the preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only,. and they are not intended as a definition of the limits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIGURE 1 is a top perspective view of an illuminating device in accordance with a first embodiment of the present invention having a CCFL formed in a conical spiral; [0013] FIGURE 2 is a top view of the device of FIGURE 1 ; [0014] FIGURE 3 is a bottom perspective view of the device of FIGURE 1; [0015] FIGURE 4 is a side perspective view of a device in accordance with another embodiment of the present invention having a nested pair of conical spiral CCFLs that are coaxially aligned; [0016] FIGURE 5 is a perspective view of device in accordance with another embodiment of the present invention having a flat wound spiral CCFL; [0017] FIGURE 6 is a side perspective view of the device of FIGURE 5; [0018] FIGURE 7 is a side view of a device in accordance with another embodiment of the present invention having an inverted, conical spiral CCFL; . [0019] FIGURE 8 is a perspective view of the device of FIGURE 7 disposed in a reflective housing; and [0020] FIGURE 9 is a sectional view of the base member of the device of FIGURE 7 as viewed along lines 9-9.

DETAILED DESCRIPTION OF THE INVENTION [0021] Turning first to FIGURE 1, there is shown in perspective, an illuminating device 10 according to a preferred embodiment of the present invention. The device 10 includes a base member 12 that defines apertures 14,16 to accommodate the ends of a CCFL 18. As is well known, the CCFL 18 comprises an elongate tube 11 having first and second ends 13 and 15 in which electrodes 17 are disposed. The tube 11 is wound in a conical spiral with the apex of the cone at the top and the base of the cone resting on the base member 12.

[0022] Approximately one half of the CCFL extends in an ascending spiral and the other half extends in a descending spiral, with the halves interlaced so as to maximize light production over the area of the spiral. As shown in the figures, the spiral has several courses, the number of courses being limited

only by the length of the CCFL 18 but preferably, there are greater than four courses.

[0023] To improve the illuminating characteristics, the base member 12 may be coated with a reflective material 20. Light directed away from the apex of the cone would then be reflected forward, adding to the available flux.

Although not shown, additional reflective surfaces could be provided generally extending in the axial direction from the base.

[0024] Generally, a helical spiral can be fabricated by heating the tubing until is pliable and forming the helix on a heated mandrel. The pitch of the helix will be determined by the diameter of the tubing. The goal, of course, is to provide a maximum of light flux over a limited area.

[0025] There are a variety of ways that the CCFL may be connected to a source of electrical power. The base member 12 could include a pair of socket assemblies for connecting with the electrodes 17 of the CCFL such as is disclosed in US patent application S. N. 10/437, 016 which is hereby incorporated by reference in its entirety. Alternatively, a suitable mount could be provided to accept the ends and electrodes of the CCFL device such as the various embodiments disclosed in US Patent 6,135, 620 which is hereby incorporated by reference in its entirety. The underside of the base member could include a candelabra base to fit a conventional light socket.

Alternatively, a bayonet fitting could be employed or a pair of prongs which will mate with an appropriate socket that is connected to a source of power.

Naturally, provision will be made for the electronic equipment, such as a driver, necessary to convert the available electrical power to power that is compatible with CCFL operation.

[0026] Referring to the device depicted in FIGURES 1 and 2, electrodes 17 of the CCFL 18 are connected (not shown) to electrical contacts 19 disposed on the base member 12. Base member 12 in turn may be connected, directly or indirectly by way of a driver, to a source of electrical power (not shown).

[0027] If the spiral, when viewed in the axial direction, as shown in FIGURE 2, has"dark"spaces between adjacent turns, the light flux can be

increased by the addition of a second CCFL 18'which can be coaxially positioned as shown in FIGURE 4.

[0028] Considering that the tubing is cylindrical, the light intensity would be greatest along the center line of the tubing and would diminish toward the edges. Therefore, a second tube, centered between adjacent coils, would add to the light flux and generally provide a more even radiant energy pattern over the area. As shown in FIGURE 4, the second CCFL 18'nests with the first CCFL 18 to create a brighter light source over a limited area.

[0029] In yet other embodiments not shown here, additional coaxial spirals can be added to nest to provide a plurality of nested CCFL spirals. With a plurality of spirals, the level of illumination can be increased substantially.

[0030] In FIGURES 5 and 6, an alternative embodiment of the device is one in which the CCFL spiral is disposed in a flat plane. This embodiment is useful in applications where the device can be mounted directly to a surface or only a shallow depression is available.

[0031] In FIGURES 7 to 8, another alternative embodiment of illuminating device is illustrated at 40 in which the apex of the conical spiral CCFL 42 is disposed at the base member 48 thus providing the appearance of an inverted cone. In this embodiment, the ends 44 and 46 of CCFL 42 extend from the base portion of the spiral to support, and to electrically connect, the CCFL 42 in known manner to the base member 48. Base member 48 is formed as a threaded socket member for connecting to a conventional power source as described in more detail below. As shown in FIGURE 8, a coaxial conical reflector 50 returns backwards directed radiation toward the"front"to increase the overall illumination provided by the device 40 [0032] Referring to FIGURE 9, base member 48 includes a driver 52 that is electrically connected with wires 54 to electrodes that are disposed in the ends 44 and 46 of the CCFL 42. Driver 52 is electrically connected with wires 56 and 58 to wall 60 and to end 62 of the base member 48. It will be understood by persons skilled in the art that this assembly may be modified to facilitate a bayonet fitting or a prong fitting with corresponding known socket connections to a power source.

[0033) It is to be understood that what has been described is a preferred embodiment to the invention. The invention nonetheless is susceptible to certain changes and alternative embodiments fully comprehended by the spirit of the invention as described above, and the scope of the claims set out below.