Background and Field of the Invention

This invention relates to an electric light, a method of assembling an electric light and an ignition circuit housing assembly.

A fluorescent lamp is an application example of a discharge lamp and it is often preferred over an incandescent lamp because a fluorescent lamp consumes less electricity and thus saves energy. Conventionally, a fluorescent lamp comprises two opposing electrodes disposed within and at respective ends of an elongate sealed glass tube containing gas and works on the principle of passing electrons between the electrodes through the gas from one end to the other end of the tube to produce light. However, the brightness of a fluorescent lamp is dependent on the length of the tube and thus a fluorescent lamp is usually larger than an incandescent light bulb. Moreover, a fluorescent lamp requires a ballast to operate and this adds to the size of the fluorescent lamp.

In recent years, improvements have been made to reduce the size of the fluorescent lamp and Compact Fluorescent (CFL) tubes were developed. Such a tube comes in various shapes such as spiral shape or U-shape etc, so as to be as compact as possible while maintaining a certain level of brightness since the length of the tube is not reduced but oriented in a different manner. Also, the fluorescent lamp includes a base comprising a tube holder to support ends of 7 the fluorescent tube and for receiving an electronic ballast to ignite the tube. However, such an arrangement still results in a CFL of substantial size.

It is an object of the present invention to provide an electric light, a method of assembling an electric light and an ignition circuit housing assembly which addresses at least one of the disadvantages of the prior art and/or to provide the public with a useful choice.

Summary of the Invention

In a first specific expression of the invention, there is provided an electric light comprising a discharge lamp having an elongate light transmissible body; an ignition circuit arranged to be electrically connected to the discharge lamp and being received in an ignition circuit housing; wherein the elongate light transmissible body is configured to envelop at least part of the ignition circuit housing.

A discharge lamp (or arc lamp) produces light by using an electrical arc running through gas plasma and the terms are used broadly in this application to include high pressure arc lamps such as mercury vapour lamps, high pressure sodium arc lamps and metal haiide arc lamps etc, and low pressure arc lamps such as fluorescent lamps etc.

Since the elongate light transmissible body is configured to envelop at least part of the ignition circuit housing, this creates more space for the ignition circuit housing and thus, a cheaper ignition circuit or an ignition circuit with greater functionalities can be incorporated in the housing.

The discharge lamp may come in different shapes and sizes but preferably, the elongate light transmissible body is configured to form a spiral which envelops at least part of the ignition circuit housing. Advantageously, a conducting member of the ignition circuit is arranged to be accessible from outside the ignition circuit housing to enable the ignition circuit to be electrically connected to the discharge lamp. This enables a simpler assembling process and easier testing of the ignition circuit.

The conducting member of the ignition circuit may include two conductors. If the discharge lamp is a CCFL, then only one conductor may be required. Further, some special filaments may require three conductors.

The electric light may include two connection members arranged to connect to respective ends of the discharge lamp, the connection members being arranged on the sides of the ignition circuit housing. Each connection member may include a circular cavity for receiving the ends of the discharge lamp.

It is preferred that the connection members are integrally formed with the ignition circuit housing.

It is also envisaged that the ignition circuit housing includes a light source which may radiates omnidirectional light. In the alternative, the light source may be arranged to project a beam of light. If the light transmissible body forms a spiral, then, the beam of light is arranged to project through an upper opening of spiral. The light source may include an LED.

Preferably, the (secondary) light source has a different colour temperature from the discharge lamp and this is to create a different lighting impression. Indeed, having a secondary light source forms a second specific expression of the invention which provides an electric light comprising a discharge lamp having an elongate light transmissible body; an ignition circuit arranged to be electrically connected to the discharge lamp and which is received in an ignition circuit housing; and a further light source housed within the ignition circuit housing.

Preferably, the further light source has a different colour temperature as the discharge lamp. Alternatively, the further light source may be arranged to project a beam of light through the discharge lamp. If the elongate light transmissible body forms a spiral, then the spiral may envelop at least part of the ignition circuit housing.

In a third specific expression of the invention, there is provided an ignition circuit housing assembly for an electric light, the ignition circuit assembly comprising a base for connection to an electrical socket; an ignition circuit arranged to be electrically connected to a discharge lamp; an ignition circuit housing cooperating with the base to define an internal space for receiving the ignition circuit; wherein the electrical connection between the ignition circuit and the discharge lamp is located outside of the ignition circuit housing.

With the electrical connection between the discharge lamp and ignition circuit located outside of the ignition circuit housing, this simplifies the assembling process and reduces assembly time.

Preferably, the ignition circuit housing includes access apertures to enable conductors from the ignition circuit to project out of the ignition circuit housing. In this way, the ignition circuit may be tested easily and also prior to mounting the discharge lamp.

The ignition circuit housing may include connection means for attaching to ends of a discharge lamp.

To assembly the ignition circuit housing assembly and a discharge lamp, the method includes attaching the discharge lamp to the ignition circuit housing assembly, and electrically connecting the discharge lamp to the ignition circuit, wherein the electrical connection is located outside of the ignition circuit housing.

To form the electrical connection, it is preferred to solder conductors of the ignition circuit and conductors of the discharge lamp. However, other forms of electrical connection is envisaged. The electric light may include an energy saving lamp or in the form of a CFL (Compact Fluorescent Lamp) or CCFL.

Brief Description of the Drawings

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which,

Figure 1 is a perspective view of an electric light having a spiral shape fluorescent lamp that surrounds an ignition circuit housing, according to a preferred embodiment of the invention;

Figure 2 is a side view of the electric light of Figure 1 ;

Figure 3 is a close-up enlarged view of the ignition circuit housing of Figure 1 , not showing the spiral shape fluorescent lamp; Figure 4 is another view of the ignition circuit of Figure 3 with two side connectors detached to reveal the conductors of an ignition circuit;

Figure 5 is a close-up view of the conductors of the ignition circuit of Figure 4 showing how the conductors make contact with corresponding conducting elements of the fluorescent lamp; and Figures 6 and 7 (with fluorescent lamp attached) show variations of the ignition circuit housing of Figure 3.

Detailed Description of the Preferred Embodiment Figures 1 and 2 show an electric light 100 in the form of a Compact Fluorescent Light (CFL) according to a preferred embodiment of the present invention. The CFL 100 comprises a discharge lamp in the form of a spiral shape fluorescent lamp 102, an ignition circuit housing 104 arranged to be electrically connected to the fluorescent lamp 102 and a base 106 connected to the ignition circuit housing 104. The base 106 includes a conductive screw cap 108 with a threaded body and a central electrical contact 110. The configuration of the conductive screw cap 108 and the central electrical contact 110 is to enable the CFL 100 to be secured to a standard light bulb socket without modification.

It would be appreciated that the fluorescent lamp 102 forms a spiral 112 having a longitudinal axis that envelops or surrounds at least part of the ignition circuit housing 104. Figure 3 shows the ignition circuit housing 104 and the base 106, without the fluorescent lamp 102. The ignition circuit housing 104 cooperates with the base 106 to define an internal space for housing an ignition circuit (not shown) such as a ballast.

The ignition circuit housing 104 has a main cylindrical body 114 and a hemispheric end cap 116 arranged to enclose the main cylindrical body 114. The main cylindrical body 114 is arranged to be screwed to the base 106 similarly the end cap 116 is also screwed to the main cylindrical body 114. The main cylindrical body 114 includes two access apertures 118,120 formed on its sides to allow two conductors 122,124 of the ignition circuit to project through each aperture 118,120, as shown in Figures 4 and 5. Adjacent each aperture 118,120 is a connection member in the form of a circular channel 126,128 that is integrally formed with the main cylindrical body 114.

The circular channels 126,128 are identical and thus, only one channel 126 is described. The channel 126 is open at both ends with a first end 126a adapted to receive an end portion 130 (and likewise the other channel 128 is arranged to receive a second end portion) of the fluorescent lamp 102. The end portion 130 of the fluorescent lamp 102 includes two projecting elongate conducting elements 134 (and similarly conducting elements 136 are also present in the second end portion, although not shown) and these conducting elements 134 are arranged to make electrical contact with corresponding conductors 122 of the ignition circuit. The electrical contact is shown clearly in Figure 5 so that the fluorescent lamp 102 is electrically connected to the ignition circuit. It should be appreciated that the electrical connection is formed outside or external of the ignition circuit housing 104. Connectors 136,138 are used to cover up the access apertures 118,120 so that a nice finish is achieved. The connectors 136,138 include catch elements 136a,136b,138a,138b that catch onto correspond grooves formed on the inside surfaces of the channels 126,128 and the cylindrical body 114.

The configuration of the CFL 100 of the present invention enables ease of production, assembling and testing. For example, an intermediate assembly comprising the ignition circuit, ignition circuit housing 104 and the base 106 (i.e. what is shown in Figure 2) may be assembled by a third party or from a process separate from that for the fluorescent lamp. Since the conductors 122,124 are accessible via the access apertures 118,120, this allows the intermediate assembly to be tested, for example at the third party site or by incoming quality control before the fluorescent lamp 102 is mounted.

To assemble the intermediate assembly and the fluorescent lamp 102, the end portions 130 (only one end portion is shown in the drawings) of the fluorescent lamp 102 are inserted into the respective channel 126,128. The connectors 136,138 are removed or detached from the body of the ignition circuit housing 104 so that the conducting elements 134,136 and/or the conductors 122,124 may be adjusted so that they make electrical contact with each other. The entire CFL may also be tested at this stage.

Next, the conductors 122,124 and the conducting elements 134,136 are soldered to ensure permanent electrical contact before the connectors 136,138 are snapped to the body of the ignition circuit housing 104. Adhesive may be applied to the boundary between the connectors 136,138 and the body of the ignition circuit housing 104 and the channels 126,128 and the respective portions of the fluorescent lamp 102 if it is necessary to hold these parts in a more secure manner together.

As it can be appreciated, the configuration of the ignition circuit housing and the fluorescent lamp provides a simpler assembling process since the fluorescent lamp need only be coupled near the end of the assembling process. This also results in a much easier dissembling process, for example, at the end of the life cycle of the fluorescent lamp 102, this can be separated from the ignition circuit housing 104 (and ignition circuit) and base assembly for recycling.

Since the ignition circuit housing 104 is disposed within the space created by the spiral 112 of the fluorescent lamp 102, this makes use of the redundant space. As a result, a more compact form factor is achieved and light output may be optimised. With such an arrangement, the size of the ballast is no longer constrained by the size of the base 106 which usually requires smaller components to form the ballast and this leads to higher cost. Thus, larger and less expensive components may be used to make the ballast in view of the extra space created by the ignition circuit housing 104 that is surrounded by the spiral of the fluorescent lamp 102. With the extra space, additional electrical and electronic circuitries may be included to add more functions to the CFLs and if necessary, the height or length of the ignition circuit housing 104 may be extended to create more space.

As mentioned above, the arrangement of the fluorescent lamp and the ignition circuit housing enables more functions to be added and examples of these will now be described.

In the described embodiment, the hemispheric end cap 116 is opaque but the hemispheric end cap 116 may be light transmissible. A second light source may be incorporated within the ignition circuit housing 104 and this enables two different lighting effects. It is envisaged that the second light source may have a different colour temperature as the fluorescent lamp 102 and the contrast between the colour temperatures may be used to create a more natural dimming impression which is absent from CFLs. To elaborate, when incandescent lamps dim, the colour of light generated changes in a natural manner, similar to the effect of the setting sun. However, when CFLs dim, the light colour remains constant and thus, does not create a natural effect. Having a second light source which has a different colour temperature thus allows the capability to create contrasting light effects to make CFLs dim naturally. Preferably, the second light source has a warmer colour than the light from the fluorescent lamp 102 but any colour light, such as blue or red etc, may be used. It is also preferred that this light source is controllable separately and independently from the fluorescent lamp, and also to generate different light output levels. Of course, the use of a second light source in the ignition circuit housing 104 need not be necessarily combined with the spiral fluorescent lamp 102 and it is not necessary that the spiral fluorescent lamp 102 envelops the ignition circuit housing 104.

The second light source may also be in the form of two LEDs (Light Emitting Diodes), which are arranged within an ignition circuit housing 104' having a cylindrical body 114', both of which are similar to what is shown in Figure 3. The LEDs and controlled by an LED ballast (not shown). Each LED may be arranged to project a beam of light which may of a different colour from the fluorescent lamp 102' (for example, red or blue colour etc). In this case, the end cap 116' is generally opaque except for two circular light transmissible apertures 300 (or whatever desired shape) such as that shown in Figures 7, and the locations of the apertures 300 are such as to enable the beams of light from the LEDs to project through the openings of the upper helix of the fluorescent lamp 102', as shown in Figure 6. In use, the LEDs thus create "down lights", if mounted to the ceiling, that have a different effect from the light produced by the fluorescent lamp 102'. Just like the second light source, it is preferred that the LEDs can be controlled separately so that they can generate different light output levels, and which one to turn on and off.

The described embodiment should not be construed as limitative. For example, it should be apparent that the present invention also covers other types of discharge lamps for example, compact fluorescent lights (CFL), mercury vapour arc lamps and high pressure arc lamps, not just to a fluorescent lamp. Further, the fluorescent lamp may be in other shapes and sizes and not necessary spiral shape although this shape is able to achieve great space savings and light output optimization. For example, if the fluorescent lamp is an inverted U-shape, then the ignition circuit housing may be disposed within the space created by the inverter U. In the described embodiment, the ignition circuit housing 104 has a generally cylindrical body with a hemispheric end cap 116 but it is envisaged that the housing 104 and the end cap 116 may be in other shapes. Likewise, the base 106 may be in other shapes and sizes with the screw cap 110 replaced by other electrical connection means adapted to connect the electric light 100 to other types of light sockets (eg. pin types).

Also, the electric light 100 uses a ballast as an example of an ignition circuit 14 but other suitable ignition circuits may be used to ignite the discharge lamp. Also, the ballast may be electronic, electrical or magnetic ballast. Also, in the case of a second light source which are LEDs, a ballast to drive the LEDs may not be necessary if, for example, an insulated light source such as an insulated cap LED is used. Further, the second light source may have a different colour temperature as the discharge lamp but it is also envisaged that the second light source may have the same colour temperature as the discharge lamp to enhance the light output.

Having now fully described the invention, it should be apparent to one of ordinary skill in the art that many modifications can be made hereto without departing from the scope as claimed.