200849174 九、發明說明： 【發明所屬之技術領域】 尤其係一種用於液晶顯 本發明係關於一種背光模組 示器或液晶電視之背光模組。 【先前技術】200849174 IX. Description of the invention: [Technical field to which the invention pertains] In particular, the invention relates to a liquid crystal display. The invention relates to a backlight module or a backlight module of a liquid crystal television. [Prior Art]
由於顯示裝置採用之液晶 因此為達到顯示效果，需給液 以實現顯示功能，如背光模組 板提供輝度充分且分佈均勻之 顯示面板係非發光性元件， 晶顯示面板提供一光源裝置 ’其功能在於向液晶顯示面 背光源。 °月芩閱圖1 ’係一種先前技術背光模組之電路示竟 圖三該月光杈組包括一電源電路1〇及複數燈管u。每一 燈官11包括一高壓端及—低壓端。該電源電路1〇盥該 數燈管11之高壓端電連接，其為該複數燈管^提供交产 驅動電壓。該複數燈管n之低壓端接地。該複 二 為冷陰極螢光燈管。 明芩閱圖2 ’係該背光模組之複數燈管11之理想工作 、電壓示意圖。該理想工作電壓之波形為正弦波，其不包 直流電壓成份。 請參閱圖3及圖4,係該背光模組之複數燈管u之實 際工作電壓示意圖。圖3中’該工作電壓包括一直流電： 成份Va，其值大於0，將導致該複數燈管u之汞離子偏 向低壓端移動。圖4中’該工作電壓包括一直流電壓成份Because the liquid crystal used in the display device achieves the display effect, the liquid is required to realize the display function. For example, the backlight module board provides a display panel which is non-luminescent element with sufficient brightness and uniform distribution, and the crystal display panel provides a light source device. Backlight to the LCD display. Figure 1 is a circuit diagram of a prior art backlight module. The moonlight group includes a power circuit 1 and a plurality of lamps u. Each lamp official 11 includes a high voltage end and a low voltage end. The power circuit 1 is electrically connected to the high voltage end of the plurality of lamps 11, which provides a crossover driving voltage for the plurality of lamps. The low voltage end of the plurality of lamps n is grounded. The second is a cold cathode fluorescent lamp. Figure 2 shows the ideal operation and voltage diagram of the plurality of lamps 11 of the backlight module. The waveform of the ideal operating voltage is a sine wave, which does not include a DC voltage component. Please refer to FIG. 3 and FIG. 4 , which are schematic diagrams showing the actual working voltage of the plurality of lamps u of the backlight module. In Fig. 3, the operating voltage includes a constant current: the component Va, whose value is greater than 0, causes the mercury ions of the plurality of lamps to shift toward the low voltage end. In Figure 4, the operating voltage includes the DC voltage component.
Vb’其值小於〇’將導致該複數燈管11之汞離子偏向該複 數燈管11之高壓端移動。 由於該複數燈管11之實際工作電壓中包括一直流電 6 200849174 壓成份Va或Vb，其導致該複數燈管11之汞離子偏向該複 數燈管11之高壓端或低壓端移動。這將造成該複數燈管 • 11之汞離子聚集現象，破壞該複數燈管11之汞離子均勻 分布之狀態，影響該複數燈管11之發光均勻性，從而影響 該背光模組之發光均勻性並縮短該背光模組之壽命。 【發明内容】 有鑑於此，提供一種發光均勻度較高及壽命較長之背光 模組實為必需。 ^ 一種背光模組，其包括至少一第一燈管；一電源電路， 其為該第一燈管提供交流驅動電壓；一第一偵測電路，用於 偵測該第一燈管一端之直流電壓成份；及一第一直流補償電 路，其根據該第一偵測電路偵測之直流電壓成份為該第一燈 管之另一端提供一第一直流補償電壓。 一種背光模組，其包括至少一第一燈管；一電源電路， 其與該第一燈管之高壓端電連接，為該第一燈管提供交流驅 動電壓；一第一偵測電路，其輸入端與其中一第一燈管之高 C 壓端電連接，用於偵測該第一燈管高壓端之直流電壓成份； 及一第一直流補償電路，其輸入端與該第一偵測電路之輸出 端電連接，輸出端與該至少一第一燈管之低壓端電連接，為 該至少一第一燈管之低壓端提供一第一直流補償電壓。 相較於先前技術，由於前述背光模組包括一偵測電路及 一直流補償電路，該偵測電路偵測一燈管高壓端之直流電壓 成份，該直流補償電路根據該偵測電路偵測之直流電壓成份 為該複數燈管之低壓端提供直流補償電壓，使該複數燈管二 端之直流電壓差為0，避免該複數燈管之汞離子在直流電壓 7 200849174 作用下偏向燈管之某一端，提高了該複數燈管之發光均勻度 •及其壽命，從而提高了該背光模組之發光均勻性，延長了該 ‘背光模組之哥命。 【實施方式】 請參閱圖5,係本發明背光模組第一實施方式之電路 示意圖。該背光模組包括複數燈管21、一電源電路20、一 偵測電路22及一直流補償電路23。該背光模組為直下式 背光模組。 該複數燈管21平行排列，每一燈管21包括一高壓端 211及一低壓端212,該複數高壓端211位於同一端，該複 數低壓端212位於另一端。該複數燈管21之低壓端212 電連接至該電源電路20之迴路端201。該電源電路20之 輸出端203與該複數燈管21之高壓端211電連接。該偵測 電路22之輸入端與某一燈管21之高壓端211電連接，該 偵測電路22之輸出端與該直流補償電路23之輸入端電連 接。該直流補償電路23之輸出端與該複數燈管21之低壓 端212電連接。 該電源電路20為該複數燈管21提供交流驅動電壓。 該偵測電路22用於偵測流過該被偵測之燈管21之直流電 壓成份。該直流補償電路23根據偵測之直流電壓成份為該 複數燈管21之低壓端212提供直流補償電壓。該複數燈管 21為冷陰極螢光燈管。 當該背光模組工作時，該偵測電路22偵測該燈管21 高壓端211之直流電壓成份。設該直流電壓成份為Vi，則 該直流補償電路23為該複數燈管21之低壓端212提供一 8 200849174 直流補償電壓Vo，且Vi = Vo，即該直流補償電壓v〇與該 偵測電路22偵測到之直流電壓成份Vi大小正負均相同。 如此，該直流補償電壓Vo補償該複數燈管21低壓端212 之直流電壓，使得該複數燈管21二端之直流電壓差為〇。 與先前技術相比，由於該背光模組包括一偵測電路22 ^ 一直流補償電路23,該偵測電路22偵測該燈管21高壓 端211之直流電壓成份，該直流補償電路23對該複數燈管 21低壓端212提供直流補償電壓，使該複數燈管21二端 之直流電壓差為〇’避免該複數燈管21之汞離子在直流電 作用下偏向該複數燈管21之某一端，提高了該複數燈管 21之發光均勻度及JL妻合 均w及… ^ 了該$光模組之發光 一^茶閱圖6,係本發明背光模組第二實施方式之電路 。該背光模組包括複數燈管31、—電源電路3〇、— ::偵：電路3:、一第二偵測電路-、-第-直流補償電 路33及一弟二直流補償電路％。 甩 5亥複數燈管31平杆排而丨 — 如及—低壓端312， j」母-燈管31包括-高壓端 數低壓端312位於另=:壓端311位於同一端，該複 電連接至該電源電路3G之第㈣數燈管31之低壓端312 之低壓端犯電連接至兮=路端親，該奇數燈管μ 該電源電路30之輪出端二，電路30之第二迴路端地。 電連接。 轉5亥複數燈管31之高壓端311 该第一该測電路 端311電連接，該第_ 32之輪入端與一偶數燈管31之高壓 偵測電路32之輸出端與該第一直流 9 200849174 ，補償電路33之輪入端電連接。該第 輪出端與該複數 直仙·補仏甩路33之 . ㈣一二偶數垃官31之低壓端312電連接。 °X —貞刿電路35之輸入端與一奇數严其Ή夕一厂 端3U電連接，該第二偵測 補償電路36之輪入姑+ h 〈翰“與邊弟一直流 輪出端與該複數;數二連3?。該第二直流補償電路％之 可數燈宫31之低壓端312電連接。 〜电"、书路30為該複數燈管31 ,:_管之交流艇動電壓之相位相反，即二 ί31與=㈣數燈管”之交流驅動電壓相“ 3 :★偵測電路32用於偵測該偶數燈管31高壓端 偵測電路32偵ίΐ直=補償電路33根據該第-低壓始川植 壓成份為該複數偶數燈管31之 壓鱼7第j供一第一直流補償電壓。該第一直流補償電 ^相Γ: 路％债測到之直流電壓成份大小正負 均相同:使該複數偶數燈管31二端之直流電壓差為〇。、 I 311=ΓΙ貞測電路35用於债測該奇數燈管31高廢端 壓成份。該第二直流補償電路36根據該第二 35㈣之直流電壓成份為該複數奇數燈管3 低壓端312捤供一篦-吉、、六、士、# 命 弟一直/爪補彳員電壓。該第二直流補償電 弟二㈣電路35 _到之直流電壓成份大小正負 均相同’使該複數奇數燈f31二端之直流電壓差為〇。、 該第-價測電路32與該第二偵測電路％相同。該第 -直流補償電路33與該第二直流補償電路％相同。 由於該電源電路30提供給該複數奇數燈管31與該複 數偶數燈管31之交流驅動電壓之相位相反，該複數奇數燈 10 200849174 f 31與該複數偶數燈管31之直流電壓成份 數燈管”及::數::一燈 捉t、置极補償電壓之方法， 本發明背光模組之燈管個數亦可為貝一 =ί:;=模組。該偵測電路亦 提供直流補償電壓。 t路為該燈官之南壓端 綜上所述，本發明確已符合發明專利之 式出惟，以上所述者僅為本發明之較佳實：方 安技i 圍並不以上述實施方式為限，舉凡熟習本 :廡γϊ人士棱依本發明之精神所作之等效修飾或變化， 白μ /函盍於以下申請專利範圍内。 【圖式簡單說明】 圖1係一種先前技術背光模組之電路示意圖。 =係圖1所示背光模組燈管之理想工；電壓示意圖。 ^ μ 4係®1所示背光模組燈管之實際工作電壓示意 _ 0 圖5係本發明背光模組第一實施方式之電路示意圖 圖6係本發明背光模組第二實施方式之電路示意圖 【主要元件符號說明】 電源電路 燈管 輪出端 迴路端 20、30 21、31 203 、 303 201 、 301 、 302 偵測電路 直流補償電路 高壓端 低壓端 22 、 32 、 35 23 、 33 、 36 211 、 311 212 、 312 11The value of Vb' is smaller than 〇', which causes the mercury ions of the plurality of lamps 11 to be biased toward the high voltage end of the plurality of lamps 11. Since the actual operating voltage of the plurality of lamps 11 includes a constant current 6 200849174 pressure component Va or Vb, the mercury ions of the plurality of lamps 11 are biased toward the high voltage or low pressure end of the plurality of lamps 11 . This will cause the mercury ion clustering phenomenon of the plurality of lamps to destroy the uniform distribution of the mercury ions of the plurality of lamps 11, affecting the uniformity of illumination of the plurality of lamps 11, thereby affecting the uniformity of illumination of the backlight module. And shorten the life of the backlight module. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide a backlight module having high illumination uniformity and long life. A backlight module comprising at least one first lamp; a power supply circuit for supplying an AC driving voltage to the first lamp; and a first detecting circuit for detecting a DC of the first lamp at one end a voltage component; and a first DC compensation circuit, wherein the first DC compensation voltage is provided to the other end of the first lamp according to the DC voltage component detected by the first detection circuit. A backlight module includes at least one first lamp tube; a power supply circuit electrically connected to the high voltage end of the first lamp tube to provide an AC driving voltage for the first lamp tube; and a first detecting circuit The input end is electrically connected to a high C voltage end of one of the first lamps for detecting a DC voltage component of the high voltage end of the first lamp; and a first DC compensation circuit having an input end and the first detection The output end of the measuring circuit is electrically connected, and the output end is electrically connected to the low voltage end of the at least one first lamp tube to provide a first DC compensation voltage for the low voltage end of the at least one first lamp tube. Compared with the prior art, the backlight module includes a detecting circuit and a DC compensation circuit, and the detecting circuit detects a DC voltage component of a high voltage end of the lamp, and the DC compensation circuit detects the DC voltage according to the detecting circuit. The DC voltage component provides a DC compensation voltage for the low voltage end of the plurality of lamps, so that the DC voltage difference between the two ends of the plurality of lamps is 0, and the mercury ions of the plurality of lamps are prevented from being biased toward the lamp under the action of the DC voltage 7 200849174 At one end, the uniformity of illumination of the plurality of lamps and the life thereof are improved, thereby improving the uniformity of illumination of the backlight module and prolonging the life of the backlight module. [Embodiment] Please refer to FIG. 5, which is a circuit diagram of a first embodiment of a backlight module of the present invention. The backlight module includes a plurality of lamps 21, a power circuit 20, a detecting circuit 22, and a DC compensation circuit 23. The backlight module is a direct type backlight module. The plurality of lamps 21 are arranged in parallel. Each of the lamps 21 includes a high voltage end 211 and a low pressure end 212. The plurality of high voltage ends 211 are located at the same end, and the plurality of low voltage ends 212 are located at the other end. The low voltage terminal 212 of the plurality of lamps 21 is electrically connected to the loop terminal 201 of the power circuit 20. The output terminal 203 of the power supply circuit 20 is electrically connected to the high voltage terminal 211 of the plurality of lamps 21. The input end of the detecting circuit 22 is electrically connected to the high voltage end 211 of a certain lamp tube 21. The output end of the detecting circuit 22 is electrically connected to the input end of the DC compensating circuit 23. The output of the DC compensation circuit 23 is electrically coupled to the low voltage terminal 212 of the plurality of lamps 21. The power supply circuit 20 supplies an alternating drive voltage to the plurality of lamps 21. The detecting circuit 22 is configured to detect a DC voltage component flowing through the detected lamp tube 21. The DC compensation circuit 23 provides a DC compensation voltage to the low voltage terminal 212 of the plurality of lamps 21 based on the detected DC voltage component. The plurality of lamps 21 are cold cathode fluorescent tubes. When the backlight module is in operation, the detecting circuit 22 detects the DC voltage component of the high voltage end 211 of the lamp tube 21. The DC compensation circuit 23 is provided with an 8 200849174 DC compensation voltage Vo for the low voltage terminal 212 of the plurality of lamps 21, and Vi = Vo, that is, the DC compensation voltage v〇 and the detection circuit 22 The detected DC voltage component Vi has the same positive and negative magnitude. Thus, the DC compensation voltage Vo compensates the DC voltage of the low voltage terminal 212 of the plurality of lamps 21 such that the DC voltage difference between the two ends of the plurality of lamps 21 is 〇. Compared with the prior art, the backlight module includes a detecting circuit 22 ^ a DC compensation circuit 23 , and the detecting circuit 22 detects a DC voltage component of the high voltage end 211 of the lamp tube 21 , and the DC compensation circuit 23 The low voltage terminal 212 of the plurality of lamps 21 provides a DC compensation voltage, so that the DC voltage difference between the two ends of the plurality of lamps 21 is 〇 'avoiding that the mercury ions of the plurality of lamps 21 are biased toward one end of the plurality of lamps 21 by the direct current. The illumination uniformity of the plurality of lamps 21 and the JL wife uniformity w and the improvement of the illumination of the light module are shown in Fig. 6. The circuit of the second embodiment of the backlight module of the present invention. The backlight module comprises a plurality of lamps 31, a power circuit 3, a :: detector circuit 3: a second detection circuit, a - DC compensation circuit 33, and a DC compensation circuit %.甩5 复 复 灯 31 31 31 31 31 丨 丨 丨 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 低压 低压The low voltage end of the low voltage terminal 312 of the (four)th lamp tube 31 of the power circuit 3G is electrically connected to the 兮=road end pro, the odd lamp tube μ, the wheel terminal 2 of the power circuit 30, and the second circuit of the circuit 30 End ground. Electrical connection. The first measuring circuit end 311 is electrically connected to the first detecting circuit end 311, and the output end of the high-voltage detecting circuit 32 of the even-numbered lamp tube 31 and the first straight Flow 9 200849174, the wheel-in terminal of the compensation circuit 33 is electrically connected. The first round of the exit is connected to the plurality of Zhixian·Buxi Road 33. (4) The low voltage end 312 of the one or two even number of the official 31 is electrically connected. The input end of the °X-贞刿 circuit 35 is electrically connected to an odd-numbered Ή Ή 一 一 一 一 一 一 一 一 一 , , , , + + + + + + + + + + + + + 翰 翰 翰The plural number; the number of two consecutive 3?. The second DC compensation circuit is counted as the low voltage end 312 of the lamp palace 31. 〜Electric", the book road 30 is the plural lamp tube 31, :_ tube exchange boat The phase of the dynamic voltage is opposite, that is, the AC driving voltage of the two lamps and the number of lamps is "3: ★ detection circuit 32 is used to detect the even-numbered lamp tube 31 high-voltage detection circuit 32 to detect the straight line = compensation circuit 33 according to the first-low pressure zechuan irrigating component is the first dc compensation voltage of the squid 7 of the plurality of lamps 31. The first DC compensation circuit Γ: the road% debt is measured The DC voltage component has the same positive and negative magnitudes: the DC voltage difference between the two ends of the plurality of even lamps 31 is 〇, and the I 311=test circuit 35 is used to measure the high waste end pressure component of the odd lamp 31. The DC compensation circuit 36 is based on the DC voltage component of the second 35 (four) for the plurality of odd-numbered lamps 3 low-voltage end 312 for a 篦-吉,, 六,士,# The brother has been / claw to compensate the voltage. The second DC compensation electric brother two (four) circuit 35 _ to the DC voltage component size is the same positive and negative 'make the complex odd-numbered lamp f31 two-terminal DC voltage difference is 〇., the first - The price measurement circuit 32 is the same as the second detection circuit %. The first DC compensation circuit 33 is identical to the second DC compensation circuit %. Since the power supply circuit 30 is provided to the plurality of odd lamps 31 and the complex even lamps The phase of the alternating current driving voltage of 31 is opposite, the complex odd-numbered lamp 10 200849174 f 31 and the plurality of even-numbered lamps 31 have a DC voltage component number of lamps "and:: number:: a lamp to capture t, the pole to compensate the voltage method, The number of the lamps of the backlight module of the present invention may also be a Bieyi=ί:;= module. The detection circuit also provides a DC compensation voltage. The road is the south end of the lamp officer, and the present invention has indeed met the formula of the invention patent. The above is only the preferred embodiment of the invention: Fangan Technology is not implemented as described above. The method is limited to the equivalent modifications or variations made by the 庑γϊ person in accordance with the spirit of the present invention, and the white μ/function is within the scope of the following patent application. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of a prior art backlight module. = ideal for the backlight module lamp shown in Figure 1. Voltage diagram. ^ FIG. 5 is a circuit diagram of a first embodiment of a backlight module of the present invention. FIG. 6 is a circuit diagram of a second embodiment of the backlight module of the present invention. [Main component symbol description] Power circuit lamp tube output circuit end 20, 30 21, 31 203, 303 201, 301, 302 detection circuit DC compensation circuit high voltage end low voltage end 22, 32, 35 23, 33, 36 211 , 311 212, 312 11