Source: http://www.google.com/patents/US7502009?dq=5,884,272
Timestamp: 2014-09-02 12:08:23
Document Index: 532117786

Matched Legal Cases: ['art.\n5', 'art.\n17', 'art.\n18', 'art.\n35', 'art.\n36', 'art.\n39', 'art 130', 'art 130', 'Application No. 2003']

Patent US7502009 - Method and apparatus for controlling operation of lamps - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA device for controlling operation of lamps is provided. The device includes a power outputting part to provide a power voltage to a lamp array having at least one lamp; a temperature sensing part to detect a temperature of the lamp and to generate a temperature signal; and a controlling part to compare...http://www.google.com/patents/US7502009?utm_source=gb-gplus-sharePatent US7502009 - Method and apparatus for controlling operation of lampsAdvanced Patent SearchPublication numberUS7502009 B2Publication typeGrantApplication numberUS 10/916,691Publication dateMar 10, 2009Filing dateAug 11, 2004Priority dateAug 11, 2003Fee statusPaidAlso published asCN1580905A, CN100460955C, US20050078080Publication number10916691, 916691, US 7502009 B2, US 7502009B2, US-B2-7502009, US7502009 B2, US7502009B2InventorsSeock-Hwan Kang, Hyeong-Suk Yoo, Gi-Chang ParkOriginal AssigneeSamsung Electronics Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (12), Non-Patent Citations (1), Referenced by (5), Classifications (9), Legal Events (3) External Links: USPTO, USPTO Assignment, EspacenetMethod and apparatus for controlling operation of lampsUS 7502009 B2Abstract A device for controlling operation of lamps is provided. The device includes a power outputting part to provide a power voltage to a lamp array having at least one lamp; a temperature sensing part to detect a temperature of the lamp and to generate a temperature signal; and a controlling part to compare the temperature of the lamp with a threshold temperature to generate a first switching signal, in response to the temperature signal, and to output the first switching signal to the power outputting part to feedback control the temperature of the lamp.
a controlling part to compare the temperature of the lamp with a threshold temperature at which pinholes are generated to generate a first switching signal, in response to the temperature signal, and to output the first switching signal to the power outputting part to feedback control the temperature of the lamp.
2. The device of claim 1, wherein the controlling part generates the first switching signal to reduce the power voltage of the power outputting part, when the temperature of the lamp is within the threshold temperature.
3. The device of claim 1, wherein the controlling part generates the first switching signal to cut off the power voltage of the power outputting part, when the temperature of the lamp is higher than the threshold temperature.
4. The device of claim 1, further comprising a switching part to receive a direct current from an outside and to provide the direct current with the power outputting part, in response to the first switching signal from the controlling part.
5. The device of claim 4, wherein the switching part includes a transistor.
6. The device of claim 4, wherein the power outputting part includes:
7. The device of claim 6, wherein the output portion includes first to third coils, wherein the first coil receives the alternative current from the inductor, the second coil selectively activates the first and second transistors in response to the alternative current applied to the first coil, and the third coil induces the alternative current to have a high level and generates the power voltage with the high alternative current.
8. The device of claim 7, wherein the third coil has ends connected to both ends of the lamp to provide the power voltage to the lamp.
9. The device of claim 7, wherein the third coil has one end connected to either end of the lamp to provide the lamp with the power voltage, and the other end connected to a ground.
10. The device of claim 6, wherein the output portion includes first to fourth coils, wherein the first coil receives the alternative current from the inductor, the second coil selectively activates the first and second transistors in response to the alternative current applied to the first coil, and the third and fourth coils induce the alternative current to have a high level and generates the power voltage with the high alternative current, and wherein the third and fourth coils are connected to either end of the lamp, respectively.
11. The device of claim 6 wherein the power voltage has a first high alternative current applied to a first end of the lamp, and a second alternative current, which has a 180 degree phase difference from the first alternative current, applied to a second end of the lamp.
12. The device of claim 6, wherein the device further comprises a lamp current detector to detect the alternative current output from the input portion of the power outputting part, and
13. The device of claim 6, wherein the device further comprises a lamp current detector to detect the alternative current output from the output portion of the power outputting part, and
14. The device of claim 6, wherein the device further comprises a lamp current detector to detect current output from the lamp, and
15. The device of claim 6, wherein the lamp array includes a plurality of the lamps, and the device further comprises a lamp current detector to detect an average value of currents output from the lamps of the lamp array, and
16. The device of claim 4, further comprising a transistor driver to amplify the first switching signal output from the controlling part and to provide an amplified first switching signal to the switching part.
17. The device of claim 4, further comprising a diode connected between the switching part and the power outputting part to prevent a flow of a reverse current from the power outputting part to the switching part.
18. The device of claim 1, wherein the temperature sensing part includes at least one temperature detector adjacently disposed at either end or both ends of the lamp.
19. The device of claim 1, wherein the temperature sensing part includes at least one temperature detector making contact with either end or both ends of the lamp.
20. The device of claim 1, wherein the temperature sensing part includes at least one temperature detector disposed adjacent to the at least one lamp, and wherein the temperature sensing part generates the temperature signal indicating the temperature detected at the lamp.
21. The device of claim 1, wherein the temperature sensing part includes a thermister to detect the temperature of the lamp.
22. The device of claim 1, wherein the controlling part includes a pulse width modulator.
23. The device of claim 1, wherein the controlling part includes an on/off controller to activate the controlling part in response to an on/off signal from an outside.
24. The device of claim 1, further comprising a digital-to-analogue converter to convert a DIMM signal received from an outside into an analogue DIMM signal and to provide the controlling part with the analogue DIMM signal.
27. A backlight assembly, comprising:
28. The backlight assembly of claim 27, wherein the at least one lamp includes at least one of an external electrode fluorescent lamp (EEFL) and an external-internal electrode fluorescent lamp (EIFL); and
29. The backlight assembly of claim 27, wherein the lamp array include at least one cold cathode fluorescent lamp.
30. The backlight assembly of claim 27, wherein the lamp includes a pair of metal clips coupled to both ends of the lamp.
31. The backlight assembly of claim 30, wherein the temperature sensing part includes at least one temperature detector adjacent disposed to either end of the lamp, and wherein the temperature detector detects a temperature of the metal cap coupled to either end of the lamp and generate the temperature signal.
32. The backlight assembly of claim 27, wherein the temperature sensing part includes at least one temperature detector disposed adjacent to either end of the lamp to detect the temperature of the lamp and to generate the temperature signal.
33. The backlight assembly of claim 27, wherein the temperature sensing part includes at least one temperature detector making contact with either end of the lamp to detect the temperature of the lamp and to generate the temperature signal.
34. The backlight assembly of claim 27, wherein the device further includes a switching part to receive a direct current from an outside and to provide the power outputting part with the direct current, in response to the first switching signal from the controlling part.
35. The backlight assembly of claim 34, wherein the device further includes a transistor driver to amplify the first switching signal output from the controlling part and to output the amplified first switching signal to the switching part.
36. The backlight assembly of claim 34, wherein the power outputting part converts the direct current from the switching part into an alternative current, induces the alternative current to have a high level, and generates the power voltage with the high alternative current.
37. The backlight assembly of claim 36, wherein the power voltage has a first high alternative current applied to a first end of the lamp, and a second alternative current, which has a 180 degree phase difference from the first alternative current, applied to a second end of the lamp.
38. The backlight assembly of claim 27, wherein the device further includes a DAC to convert a digital DIMM signal received from an outside into an analogue DIMM signal and to output the analogue DIMM signal to the controlling part.
39. The backlight assembly of claim 27, wherein the device further includes a lamp current detector to detect current of to the lamp; and
40. The backlight assembly of claim 27, wherein the controlling part generates the first switching signal to reduce the power voltage of the power outputting part, when the temperature of the lamp is within the threshold temperature; and
41. The backlight assembly of claim 27, further comprising:
42. The backlight assembly of claim 27, wherein the backlight assembly includes a direct type backlight assembly.
a controlling part to compare the temperature of the lamp with a threshold temperature at which pinholes are generated to generate a first switching signal, in response to the temperature signal, and to output the switching signal to the power outputting part to feedback control the temperature of the lamp.
44. The liquid crystal display device of claim 43, wherein the lamp includes an external electrode at either end or both end of the lamp.
45. The liquid crystal display device of claim 43, wherein the lamp array includes a plurality of the lamps connected to each other in parallel.
46. The liquid crystal display device of claim 43, wherein the device further includes a switching part to receive a direct current from an outside and to provide the power outputting part with the direct current in response to the first switching signal.
47. The liquid crystal display device of claim 46, wherein the power outputting part converts the direct current output from the switching part into an alternative current, induces the alternative current to have a high level, and generate the power voltage with the high alternative current, and wherein the power voltage is applied to either end or both ends of the lamp.
48. The liquid crystal display device of claim 43, wherein the device further includes a lamp current detector to detect current of the lamp; and
49. A method for controlling operation of lamps, comprising:
generating a first switching signal by comparing the temperature of the lamp with a threshold temperature at which pinholes are generated; and
50. The method of claim 49, wherein supplying a power voltage includes:
51. The method of claim 50, wherein supplying a power voltage further includes:
52. The method of claim 49, wherein the method further comprises detecting current of the lamp; and
53. The method of claim 49, wherein generating the first switching signal includes:
54. The method of claim 49, wherein feedback controlling the temperature of the lamp includes:
55. The method of claim 49, further comprising amplifying the first switching signal.
56. The method of claim 49, further comprising controlling the supplying of the power voltage in response to the first switching signal. Description
SUMMARY OF THE INVENTION The present invention provides a device and method to control the operation of lamps connected to each other in parallel, in which the temperature of the lamps is controlled lower than a threshold temperature on which pinholes are generated at the external electrodes of the lamps.
DETAILED DESCRIPTION OF THE INVENTION Hereinafter exemplary embodiments of the present invention will be described in detail with reference to the accompanied drawings.
FIG. 2 is a view illustrating a plasma distribution on an external electrode of EEFL in which first to third electric field lines EFL1 to EFL3 are indicated. The EEFL 12 includes a glass 12 a and an external electrode 12 b surrounding the glass 12 a. When a voltage higher than a threshold voltage of a capacitor is applied to the external electrode 12 b of the EEFL 12, an electric filed is intensively created at a narrow portion of a plasma sheath area 12 c according to the plasma sheath's distribution. A temperature is remarkably increased at the narrow sheath area. When the temperature at the narrow sheath area reaches the threshold temperature (Tg) of the glass 12 a, for example 500� C., pinholes are generated due to the pressure difference between inside and outside of the lamp 12. The higher the temperature is, the lower the electrical resistance of the glass is. Thus, a higher electrical charge at the lower resistance rapidly spreads out the pinholes into the entire external electrode 12 b to thereby break down insulation.
2.6 mm/
3.0 mm/
15 mm/
5 mm/
(diameter/length/thickness)
Capacitance of external
Threshold voltage [Vrms]
2516 V
(8.5 mA)
(9.7 mA)
(6.5 mA)
Threshold temperature [� C.]
As shown in TABLE 1, when the EEFL 12 has a diameter of 2.6 mm, the external electrode 12 b having a length of 15 mm and the glass 12 a having a thickness of 0.3 mm, pinholes are generated at an electrode capacitance of 17 pF, a threshold voltage of 2516 V and a temperature of 210� C. Alternatively, when the EEFL 12 has a diameter of 3.0 mm, the external electrode 12 b having a length of 15 mm and the glass 12 a having a thickness of 0.3 mm, pinholes are generated at an electrode capacitance of 20 pF, a threshold voltage of 2480 V and a temperature of 240� C. Alternatively, when the EEFL 12 has a diameter of 3.0 mm, the external electrode 12 b having a length of 15 mm and the glass 12 a having a thickness of 0.5 mm, pinholes are generated at an electrode capacitance of 11 pF, a threshold voltage of 3520 V and a temperature of 130� C.
The device 924 provides the first and second electrical powers to the plurality of lamps 921 a connected with each other in parallel. In addition, the device 924 controls the first and second electrical powers in accordance with the temperature detected by a temperature sensing part 130. The temperature sensing part 130 includes first and second temperature detectors 132 and 134 disposed adjacent to the lamps 921 a. Although FIG. 10 shows the temperature detectors 132 and 134 disposed adjacent to the both ends of a lamp 921 a, the temperature detectors 132 and 134 may be directly disposed on the both ends of the lamp 921 a or one temperature detector may be directly disposed on one end of the lamp 921 a. The bottom chassis 925 is formed into a hexahedral box of which an upper face is removed, and has a predetermined receiving space therein. The reflector 923 is disposed along inner surfaces of the receiving space, and the lamp unit 921 is disposed above the reflector 923 in parallel therewith. The light regulator 922 is disposed above the lamp unit 921 spaced apart by a predetermined distance.
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