| JP61142663 | FLUORESCENT LAMP DEVICE |
| JP07065788 | FLAT FLUORESCENT LAMP |
| JP63299044 | FLUORESCENT LAMP FOR MANUSCRIPT LIGHTING |
KALECINSKI, Mariusz Miroslaw (Philips China Investment Co, ltdLane 888, Tian Lin Road, Shanghai 3, 20023, CN)
| CLAIMS: 1. A compact fluorescent lamp, comprising: a spiral compact fluorescent burner (110, 210); and an envelope (120, 320) for covering the burner (110, 210), the envelope (120, 320) having an opening (130) through which the burner (110, 210) can be placed in the envelope (120, 320); wherein the envelope (120, 320) is made of an elastic material enabling deformation of the envelope (120, 320); the diameter of the opening (130) is smaller than the largest diameter of the burner (110, 210) when the envelope (120, 320) is in an undeformed state; and the diameter of the opening (130) is larger than the largest diameter of the burner (110, 210) when the envelope (120, 320) is in a deformed state. 2. A compact fluorescent lamp as claimed in claim 1, wherein the opening (130) is adjacent to a shell (140) containing a driver of the compact fluorescent lamp. 3. A compact fluorescent lamp as claimed in claim 1, wherein the envelope (320) further covers a shell (140) containing a driver of the compact fluorescent lamp. 4. A compact fluorescent lamp as claimed in claim 1 , wherein the elastic material is silicone rubber. 5. A compact fluorescent lamp as claimed in claim 1, wherein the envelope (120, 320) is transparent or translucent. |
FIELD OF THE INVENTION
The invention relates to illumination, in particular to a compact fluorescent lamp.
BACKGROUND OF THE INVENTION
A compact fluorescent lamp (CFL), also known as a compact fluorescent light or energy saving light, is a type of fluorescent lamp. Compared to general service incandescent lamps giving the same amount of visible light, CFLs use less power and have a longer rated life.
Lighting company ClearLite has introduced a new ArmorLite CFL bulb with an unbreakable safety shell that prevents mercury in the bulb from escaping. The new ArmorLite bulb is basically a regular spiral fluorescent burner placed in a glass envelope inside a protective safety coating (i.e. the SX-4000 silicone skin), and it looks like an incandescent bulb. In the event of breakage, the new ArmorLite bulb will keep all the broken shards of glass as well as mercury safely inside the silicone skin.
SUMMARY OF THE INVENTION
The inventor of the present invention has recognized that there are some disadvantages to the new ArmorLite CFL described above.
Firstly, if the diameters of the different loops of the spiral burner vary greatly (for example, the profile of the spiral burner is substantially fusiform or conical with respect to the longitudinal axis of the burner), the shape of the glass envelope cannot match exactly with the profile of the spiral burner, because the burner needs to be placed in the glass envelope through an opening of the glass envelope and the largest diameter of the burner must be smaller than the diameter of the opening. Therefore, there will be a large space between the burner and the glass envelope, causing glass to be wasted. In addition, the size of the burner is limited by the size of the opening of the glass envelope, and it is difficult to improve the luminous flux per cubic meter. Secondly, although the glass envelope is coated with the silicone skin, the glass envelope is still breakable if the new ArmorLite CFL is struck with great force.
Based on the understanding of the prior art and the problems described above, it would be advantageous to reduce the space between the burner and the envelope of a CFL. It would also be desirable that the size of the burner is not limited by the size of the opening of the envelope. It would also be preferable to better protect the CFL from breakage.
To better address one or more of the above concerns, according to an embodiment of the invention, a compact fluorescent lamp is provided. The compact fluorescent lamp comprises: a spiral compact fluorescent burner; and
an envelope for covering the burner, the envelope having an opening through which the burner can be placed in the envelope; wherein
the envelope is made of an elastic material enabling deformation of the envelope;
the diameter of the opening is smaller than a largest diameter of the burner when the envelope is in an undeformed state; and
the diameter of the opening is larger than the largest diameter of the burner when the envelope is in a deformed state.
The elastic envelope can act as a crash cushion for the CFL, so that the burner in the envelope can be better protected against shattering. In addition, even if the largest diameter of the burner is larger than the diameter of the opening of the envelope in the undeformed state, the envelope can deform to enable the burner to be placed in the envelope through the opening of the envelope. In this way, the shape of the envelope can match exactly with the profile of the burner, and thus the space between the burner and the envelope can be small. Furthermore, for the same size of the envelope, a larger burner can be implemented and hence a higher luminous flux per cubic meter can be achieved.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
DESCRIPTION OF THE DRAWINGS The above and other objects and features of the present invention will become more apparent from the following detailed description considered in connection with the accompanying drawings, in which:
Fig. la depicts a schematic diagram of a CFL in accordance with an embodiment of the present invention;
Fig. lb depicts a schematic diagram of an undeformed envelope of an embodiment of the present invention;
Fig.lc depicts a schematic diagram of a deformed envelope of an embodiment of the present invention;
Fig.2 depicts a schematic diagram of a CFL in accordance with another embodiment of the present invention; and
Fig.3 depicts a schematic diagram of a CFL in accordance with a further embodiment of the present invention.
The same reference numerals are used to denote similar parts throughout the Figures.
DETAILED DESCRIPTION
Fig. la depicts a schematic diagram of a CFL in accordance with an embodiment of the present invention.
According to an embodiment of the invention, a CFL is provided.
Referring to Fig. la, the CFL comprises a spiral compact fluorescent burner 110. The burner 110 can also be called a tube. The burner 110 is filled with a gas (such as mercury vapor).
An electrical current flows through the gas and then causes it to emit ultraviolet light. The ultraviolet light then excites a phosphor coating on the inside of the burner 110, causing it to emit visible light. The profile of the burner with respect to the longitudinal axis of the burner can have many kinds of shapes. For example, the profile of the burner 110 shown in Fig. la is substantially cylindrical.
The CFL further comprises an envelope 120 for covering the burner 110. The envelope 120 has an opening 130 and the burner 110 can be placed in the envelope 120 through the opening 130. The envelope can have many kinds of shapes. For example, the shape of the envelope matches with the profile of the burner. In another example, the shape of the envelope is spherical. Depending on the requirements for the appearance of the CFL, the envelope can be transparent or translucent. The opening of the envelope can have many kinds of shapes. Preferably, the shape of the opening is circular.
The envelope 120 is made of an elastic material, enabling deformation of the envelope 120. When forces are applied to the envelope 120, the envelope 120 can deform. The deformation is elastic deformation and is reversible. When forces are no longer applied to the envelope 120, the envelope 120 can return to its original shape. The elastic material can be many kinds of material. For example, the elastic material is silicone rubber or thermoplastic rubber. The elastic envelope can act as a crash cushion for the CFL, so that the burner in the envelope can be better protected against shattering.
Preferably, the elastic material is made of liquid silicone rubber (LSR), so that the envelope can have a high temperature resistance (up to 230 degrees centigrade), a high elongation percentage (100% to 700%) and a high visible light transparency. Alternatively, the elastic material can be colored.
Fig. lb depicts a schematic diagram of an undeformed envelope of an embodiment of the present invention. Referring to Fig. lb, the envelope 120 is in an undeformed state (i.e. no force is applied to the envelope 120), and the diameter Dl of the opening 130 is smaller than the largest diameter DO of the burner 110. The largest diameter of the burner 110 is the maximum width of the burner's shadow projected on a plane vertical to the longitudinal axis of the spiral burner 110.
Fig.lc depicts a schematic diagram of a deformed envelope of an embodiment of the present invention. Referring to Fig.lc, the envelope 120 is in a deformed state (i.e. forces are applied to the envelope 120), and the diameter D2 of the opening 130 is larger than the largest diameter DO of the burner 110. In other words, the elongation percentage of the elastic material is higher than the ratio between the largest diameter of the burner and the diameter of the opening of envelope in the undeformed state.
In this way, even if the largest diameter of the burner is larger than the diameter of the opening of the envelope in the undeformed state, the envelope can deform to enable the burner to be placed in the envelope through the opening of the envelope. Therefore, the shape of the envelope can match exactly with the profile of the burner, and hence the space between the burner and the envelope can be small. Furthermore, for the same size of the envelope, a larger burner can be implemented and thus a higher luminous flux per cubic meter can be achieved.
As shown in Fig. la, the opening 130 is adjacent to a shell 140 containing a driver (not shown) of the CFL. In other words, the opening 130 is connected with an edge of the shell 140. The shell can be made of many kinds of materials, such as plastic or glass, etc. The driver is configured for driving the burner 110. The driver can be implemented in many ways. For example, the driver comprises a ballast. In another example, the driver comprises a ballast and a starter. Preferably, the driver comprises a base 150 adapted for coupling with an electrical light socket (not shown).
Fig.2 depicts a schematic diagram of a CFL in accordance with another embodiment of the present invention.
Referring to Fig.2, the profile of burner 210 with respect to the longitudinal axis of the burner 210 is substantially fusiform. This means that (?) when the envelope 120 is in an undef ormed state, the diameter D4 of the opening 130 is smaller than the largest diameter D3 of the burner 210. And when the envelope 120 is in a deformed state (not shown), the diameter of the opening 130 is larger than the largest diameter D3 of the burner 210.
Fig.3 depicts a schematic diagram of a CFL in accordance with a further embodiment of the present invention.
Referring to Fig.3, the envelope 320 further covers the shell 140 containing the driver (not shown) of the CFL. When the shell is made of breakable materials (such as plastic or glass), the envelope 320 made of an elastic material is shatter-proof. In this way, the CFL is completely shatter-proof and users can be better protected. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed in a limiting sense. The word "comprising" does not exclude the presence of elements or steps not listed in a claim or in the description. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. In the apparatus claims enumerating several units, several of these units can be embodied by one and the same item of hardware or software.
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