CN1964590A - A drive method for square-wave voltage for flat lamp - Google Patents

A drive method for square-wave voltage for flat lamp Download PDF

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Publication number
CN1964590A
CN1964590A CN 200510115931 CN200510115931A CN1964590A CN 1964590 A CN1964590 A CN 1964590A CN 200510115931 CN200510115931 CN 200510115931 CN 200510115931 A CN200510115931 A CN 200510115931A CN 1964590 A CN1964590 A CN 1964590A
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CN
China
Prior art keywords
square
wave voltage
lamp body
driving method
voltage driving
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CN 200510115931
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Chinese (zh)
Inventor
洪金泉
黄秋凯
应建平
周清和
潘恭桐
樊雨心
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Delta Optoelectronics Inc
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HANLI PHOTOELECTRIC CO Ltd
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Priority to CN 200510115931 priority Critical patent/CN1964590A/en
Publication of CN1964590A publication Critical patent/CN1964590A/en
Pending legal-status Critical Current

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Abstract

The disclosed square wave voltage driving method for lamp used in panel display and common illumination comprises: using a power device to cut dc power into square wave voltage; lifting the rising and descending exterior edges of square wave voltage to the lighting value by a boost device; and providing an impulse current just breaking through the dielectric layer energy barrier of lamp.

Description

Be applied to the square-wave voltage driving method of flat lamp
Technical field
The present invention relates to a kind of square-wave voltage driving method that is applied to lamp body, the driving voltage that is particularly related to a kind of plane lamp sheet utilizes square-wave voltage or multistage ladder type square-wave voltage replaces the traditional strings wave voltage, the trigger voltage of the rising of this square-wave voltage or multistage ladder type square-wave voltage and decline leading edge is promoted to a modulating voltage, and drive current is a pulsed electric current, resulting from square-wave voltage rises and the decline leading edge, can effectively break through the dielectric layer energy barrier, to promote the square-wave voltage driving method of luminous efficiency, reduction plane lamp sheet working temperature.
Background technology
LCD is subject to liquid crystal can't be luminous voluntarily, so must adopt backlight (Backlight) to come as its luminous source, the present backlight that adopts mostly is many cathode fluorescent tubes greatly and forms, form a backlight module, for the line source that many fluorescent tubes are formed becomes a planar light source, backlight module must adopt thicker diffusion sheet, so that make line source can become planar light source uniformly, but the use of this diffusion sheet will make backlight module the problem that integral thickness increases and temperature rises occur.Have again, backlight module uses for a long time with high brightness, make the temperature of fluorescent tube remain on high temperature, to cause the light output of fluorescent tube to produce the phenomenon of quickening decay, more serious problem is the rate of decay difference of each fluorescent tube of multi-light tube backlight module, use for a long time, will form the uneven big problem of LCD brightness.Institute thinks and addresses this problem, and has researched and developed a kind of cold-cathode plane lamp and has done Backlight For Liquid Crystal Display Panels.
Please refer to Fig. 1, oscillogram for the driving voltage and the drive current of known cold-cathode plane lamp, wherein this driving voltage 11 and drive current 12 all come as its drive waveforms with the string ripple, but this drive waveforms can form great circulating current (Circulating Current), (not shown) when flowing through drive circuit and plane lamp sheet, to cause meaningless power loss, its shortcoming haves much room for improvement for luminous efficiency that reduces plane lamp sheet and the phenomenon that causes the backlight module heating.
Please refer to Fig. 2, oscillogram for the driving voltage and the drive current of another known cold-cathode plane lamp, its driving voltage 21 adopts unipolar pulse voltage system to drive, drive current 22 then is less pulse current, adopt single voltage to drive and will form the output of single direction light, the type of drive of this unipolar pulse voltage has following shortcoming:
(1) employed type of drive is the pulse voltage of fixed single polarity, increase along with the operating time, the free positive and negative ion that is produced of the inert gas molecule that lamp sheet inside, plane is filled can depend on, be deposited near the electrode, form electrolytic effect and accumulation wall electric charge (Wall Charge) effect, after two kinds of above-mentioned effects form, after must raising, driving voltage just can overcome this dielectric layer energy barrier, so just cause the problem that luminous efficiency reduces and plane lamp sheet temperature raises, but also produced the electric arc problem of unstable.
(2) problem supervened of above-mentioned dielectric layer energy barrier is the problem (driving voltage is usually greater than 2kV) that driving voltage need raise, thing followed problem is electromagnetic interference (ElectromagneticInterference, EMI) effect also increases, so this backlight module is difficult for by the associated electrical magnetic tester as EMI/EMC such as CE, FCC when operation.
Please refer to Fig. 3, be the oscillogram of the drive current of another known cold-cathode plane lamp, its drive current utilizes triple-frequency harmonics 32 injection modes (3 RdHarmonic Injection Method) mixes once main ripple 31 (sine wave), form a kind of synthetic waveform 33 near trapezoidal wave, this drive current has the shortcoming of systemic circulation electric current in the time of can improving the driving of string ripple, can reduce the working temperature of plane lamp sheet and then improve luminous efficiency, but still there is following shortcoming in this drive current:
(1) transformer that provided in the circuit is needed in addition control accurately, especially its leakage inductance and the formed resonance frequency of resonant capacitance that adds must accurately be three times a switching frequency, otherwise can't form this trapezoidal wave waveform.
Therefore (2) the formed synthetic trapezoidal wave waveform in the high-pressure side of its transformer will form transformer additional cycles electric current, so still have the problem of meaningless power loss, also must promote the driving voltage power of covering the loss, and the while electromagnetic interference effect is generation thereupon also.
All there is shortcoming in above-mentioned three kinds of known technologies, and the present invention is different from the type of drive of the sine wave of traditional cathode fluorescent tube and outer electrode cathode fluorescent tube, can improve the plane lamp sheet luminous efficiency of outer electrode mode.
Summary of the invention
The object of the present invention is to provide a kind of square-wave voltage driving method that is applied to lamp body, the driving voltage of its midplane lamp sheet utilizes square-wave voltage or multistage ladder type square-wave voltage replaces traditional string wave voltage, the trigger voltage of the rising of this square-wave voltage or multistage ladder type square-wave voltage and decline leading edge is promoted to a modulating voltage, and drive current is a pulsed electric current, resulting from square-wave voltage rises and the decline leading edge, can effectively break through the dielectric layer energy barrier, reach the purpose of the working temperature of bring to power, reduction plane lamp sheet.
To achieve these goals, the invention provides a kind of square-wave voltage driving method that is applied to lamp body, this lamp body refers to be applied to the lamp source of flat-panel screens and general lighting, as long as the lamp source of using dielectric layer energy barrier discharge mode, as outer electrode cold-cathode tube, plasma display panel, and using the plane lamp of outer electrode all to be suitable for the method, it comprises the following steps:
Provide a power device DC power supply to be cut into square-wave voltage;
Utilize one to boost that device rises square-wave voltage and the trigger voltage of decline leading edge is promoted to a modulating voltage; And
One pulsed electric current is provided, and this pulsed electric current just can be broken through the dielectric layer energy barrier of lamp body.
Preferable, this device that boosts promotes the trigger voltage of square wave leading edge, and the square wave leading edge is formed a high-tension pulse.
Preferable, this power device square-wave voltage that DC power supply is cut into, this square-wave voltage also can be a multistage ladder type square-wave voltage.
Preferable, this pulsed electric current results from square-wave voltage and rises and the decline leading edge.
Following conjunction with figs. and specific embodiment elaborate to feature of the present invention, but not as a limitation of the invention.
Description of drawings
Fig. 1 is the driving voltage in known cold cathode lamp source and the oscillogram of drive current;
Fig. 2 is the driving voltage in another known cold cathode lamp source and the oscillogram of drive current;
Fig. 3 is the oscillogram of the drive current in another known cold cathode lamp source;
Fig. 4 is the waveform schematic diagram of driving voltage, drive current and the light output of cold-cathode plane lamp of the present invention;
Fig. 5 is the actual driving voltage of the present invention, current measurement oscillogram.
Wherein, Reference numeral:
11,21,41, driving voltage
12,22,42 drive currents
31 once main ripples
32 triple-frequency harmonics
33 synthetic waveforms
411 modulating voltages
412 keep voltage
421 discharging currents
422 no currents
The output of 43 light
51 actual driving voltages
52 actual drive currents
Embodiment
Please refer to Fig. 4, be the oscillogram that driving voltage, drive current and the light of cold-cathode plane lamp of the present invention are exported, wherein this driving voltage 41 includes some modulating voltages 411 and keeps voltage 412; This drive current 42 includes a discharging current 421 and no current 422; Drive current 42 has discharging current 421 zones and promptly forms light and export 43 zones.But the lamp body of the present invention's application implementation refers to be applied to the lamp source of flat-panel screens and general lighting, this lamp body refers to an outer electrode cathode fluorescent tube and mercury-free plane lamp sheet, wherein the mercury-free plane lamp sheet is the main device of using, and this flat-panel screens is a LCD, and this driving method comprises the following steps:
Provide a power device DC power supply to be cut into square-wave voltage or multistage ladder type square-wave voltage, this power device refers to an electronic device that tiny signal can be amplified, it is a metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor Field Effect Transistor, MOSFET), insulation utmost point bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) or a bipolarity junction transistor (Bipolar Junction Transistor, BJT);
Utilize one to boost that device rises square-wave voltage and the trigger voltage of decline leading edge is promoted to a modulating voltage, this device that boosts promotes the trigger voltage of square wave leading edge and refers to the square wave leading edge is formed a high-tension pulse, and this assembly that boosts is a high frequency transformer, autotransformer or coupling inductance; And
One pulsed electric current is provided, and this pulsed electric current results from square-wave voltage and rises and the decline leading edge, and the pulsed electric current just can be broken through the dielectric layer energy barrier of lamp body.
Please refer to Fig. 5, be the actual driving voltage waveform figure of the present invention, can find out among the figure that the driving voltage utilization of the present invention assembly that boosts promotes the trigger voltage of square wave leading edge and is meant the square wave leading edge is formed a high-tension pulse, and square-wave voltage is subjected to influence of harmonic, be actually a multistage ladder type square-wave voltage, its drive current is a pulsed electric current simultaneously, and its no current zone also is multistage ladder type, this pulsed electric current results from square-wave voltage and rises and the decline leading edge, and it just can break through the dielectric layer energy barrier of lamp body, and this figure can react the truth of the circuit that is applied to the mercury-free plane lamp sheet.
Principal character of the present invention and advantage (be mainly and be applied to the mercury-free plane lamp sheet) as described below:
(A) utilize power device or alternate manner is cut into square-wave voltage with DC power supply;
(B) utilize traditional high frequency transformer, autotransformer or coupling inductance that square-wave voltage is raised to a modulating voltage, for the use of lighting a lamp;
(C) light a lamp after, driving voltage is kept smooth high pressure or is descended slightly, but on the whole, driving voltage is kept square wave shaped voltage;
(D) drive current is the pulsed electric current, only has electric current to exist in driving voltage rising or drop edge;
(E) drive current is the pulsed electric current, is suitable for the plane lamp sheet of outer electrode mode, can significantly improve the low shortcoming of luminous efficiency that causes because of dielectric layer energy barrier (Dielectric Barrier); That is to say, the lamp source that driving voltage user wave voltage causes the pulsed drive electric current to be suitable for using dielectric layer energy barrier discharge (Dielectric Barrier Discharge) mode is as the plane lamp of outer electrode cold-cathode tube, plasma display panel and use outer electrode;
(F) driving voltage is kept square wave shaped voltage and is helped to light a lamp once more, because be stored in the driving voltage that the charge potential of dielectric layer can help to reduce the lamp sheet;
(G) user's wave tube voltage of the present invention is irrelevant with the size of some modulating voltage peace face lamp, uses so be fit to very much large scale.
By above-mentioned Fig. 4 and shown in Figure 5, principal character of the present invention as can be known utilizes square-wave voltage or multistage ladder type square-wave voltage to replace the traditional strings wave voltage for the driving voltage with plane lamp sheet, the trigger voltage of the rising of this square-wave voltage or multistage ladder type square-wave voltage and decline leading edge is promoted to a modulating voltage, and drive current is a pulsed electric current, resulting from square-wave voltage rises and the decline leading edge, can effectively break through the dielectric layer energy barrier, reach the purpose that promotes luminous efficiency, reduces plane lamp sheet working temperature, have the market competitiveness.
Certainly; the present invention also can have other various embodiments; under the situation that does not deviate from spirit of the present invention and essence thereof; those of ordinary skill in the art can make various corresponding changes and distortion according to the present invention, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

Claims (14)

1, a kind of square-wave voltage driving method that is applied to lamp body, this lamp body refers to be applied to the lamp source of flat-panel screens and general lighting, it is characterized in that, comprises the following steps:
Provide a power device that DC power supply is cut into square-wave voltage;
Utilize one to boost that device rises square-wave voltage and the trigger voltage of decline leading edge is promoted to a modulating voltage; And
One pulsed electric current is provided, and this pulsed electric current just can be broken through the dielectric layer energy barrier of lamp body.
2, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that this lamp body refers to a cathode fluorescent tube.
3, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that, this lamp body refers to a plane lamp sheet.
4, the square-wave voltage driving method that is applied to lamp body according to claim 3 is characterized in that, this plane lamp sheet refers to a mercury-free plane lamp sheet.
5, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that this lamp body refers to a plasma display panel.
6, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that, this device that boosts refers to a high frequency transformer.
7, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that, this device that boosts refers to an autotransformer.
8, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that, this device that boosts refers to a coupling inductance.
9, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that, this power device refers to an electronic device that tiny signal can be amplified.
According to claim 1 or the described square-wave voltage driving method that is applied to lamp body of claim 9, it is characterized in that 10, this power device refers to a metal oxide semiconductor field effect transistor, insulation utmost point bipolar transistor or a bipolarity junction transistor.
11, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that, this flat-panel screens is LCD or plasma display panel.
12, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that, this device that boosts promotes the trigger voltage of square wave leading edge and is meant the square wave leading edge is formed a high-tension pulse.
13, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that, this power device also can be a multistage ladder type square-wave voltage with the square-wave voltage that DC power supply was cut into.
14, the square-wave voltage driving method that is applied to lamp body according to claim 1 is characterized in that, this pulsed electric current results from square-wave voltage and rises and the decline leading edge.
CN 200510115931 2005-11-11 2005-11-11 A drive method for square-wave voltage for flat lamp Pending CN1964590A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 200510115931 CN1964590A (en) 2005-11-11 2005-11-11 A drive method for square-wave voltage for flat lamp

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 200510115931 CN1964590A (en) 2005-11-11 2005-11-11 A drive method for square-wave voltage for flat lamp

Publications (1)

Publication Number Publication Date
CN1964590A true CN1964590A (en) 2007-05-16

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN 200510115931 Pending CN1964590A (en) 2005-11-11 2005-11-11 A drive method for square-wave voltage for flat lamp

Country Status (1)

Country Link
CN (1) CN1964590A (en)

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Owner name: TAIDA ELECTRONIC INDUSTRY CO LTD

Free format text: FORMER OWNER: HANLI OPTOELECTRONICS CO., LTD.

Effective date: 20070727

C41 Transfer of patent application or patent right or utility model
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Address after: Taipei City, Taiwan, China

Applicant after: Delta Optoelectronics Inc.

Address before: Hsinchu, Taiwan, China

Applicant before: Hanli Photoelectric Co., Ltd.

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Open date: 20070516