TWI361022B - A driving system to control power supply to a ccfl - Google Patents
A driving system to control power supply to a ccfl Download PDFInfo
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- TWI361022B TWI361022B TW93120631A TW93120631A TWI361022B TW I361022 B TWI361022 B TW I361022B TW 93120631 A TW93120631 A TW 93120631A TW 93120631 A TW93120631 A TW 93120631A TW I361022 B TWI361022 B TW I361022B
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- cold cathode
- fluorescent lamp
- cathode fluorescent
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- 238000010586 diagram Methods 0.000 description 12
- 239000003990 capacitor Substances 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 241000254158 Lampyridae Species 0.000 description 1
- 241001646071 Prioneris Species 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
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- Circuit Arrangements For Discharge Lamps (AREA)
- Discharge-Lamp Control Circuits And Pulse- Feed Circuits (AREA)
Description
1361022 100年12月29日梭正替換頁 六、發明說明： 【發明所屬之技術領域】 _ 本發明係關於一種驅動系統’尤指一種適用於冷陰極螢 光燈之電源驅動系統。 【先前技術】 [0002] 螢光燈可廣泛應用於很多場合’尤多用於需照明之情形 ，且對電源供應要求不高之場合。其中一種螢光燈為冷 陰極螢光燈（Cold Cathode Fluorescent Lamp ’ CCFL)，可用於液晶顯示面板中，以作為背光源或肩邊 光源之用，該液晶顯示面板常用於筆記型電腦、網路瀏 覽器、某些工業用之自動控制裝置及娛樂等系統中。 [0003] 冷陰極螢光燈之燈管内填充有如氬（Arg〇n>、氙（ Xenon)等惰性氣體，藉由該冷陰極螢光燈啟動時激發惰 性氣體以形成電弧來產生電流，而使該冷陰極螢光燈發 光。該等惰性氣體之激發需藉由高壓交流電來驅動形成 ，故需設計專用之驅動電路，以將外部提供之低壓直流 電轉換成高壓交流電，而提供至該冷陰極螢光燈，以驅 動該螢光燈發光。 [0004] 如第一圖，係習知冷陰極螢光燈驅動系統示意圖。該驅 動系統10包含一電源供應器12、一CCFL驅動電路16、一 控制器14、一回授迴路18及一冷陰極螢光燈11。該電源 供應器12係由該控制器14控制，以提供一直流電壓V 至1361022 December 29th, 100th, the following is a replacement page. 6. Description of the Invention: [Technical Field of the Invention] The present invention relates to a drive system, particularly a power drive system suitable for a cold cathode fluorescent lamp. [Prior Art] [0002] Fluorescent lamps can be widely used in many occasions, especially in situations where lighting is required and where power supply requirements are not high. One of the fluorescent lamps is a Cold Cathode Fluorescent Lamp 'CCFL, which can be used in a liquid crystal display panel as a backlight or a shoulder light source. The liquid crystal display panel is often used in notebook computers and networks. In browsers, some industrial automation devices, and entertainment systems. [0003] A lamp of a cold cathode fluorescent lamp is filled with an inert gas such as argon (Arg〇n) or Xenon, and an inert gas is excited by the cold cathode fluorescent lamp to generate an electric arc to generate an electric current. The cold cathode fluorescent lamp is caused to emit light. The excitation of the inert gas needs to be driven by high voltage alternating current, so a special driving circuit is needed to convert the externally supplied low voltage direct current into high voltage alternating current to be supplied to the cold cathode. A fluorescent lamp is used to drive the fluorescent lamp to emit light. [0004] As shown in the first figure, there is a schematic diagram of a conventional cold cathode fluorescent lamp driving system. The driving system 10 includes a power supply 12, a CCFL driving circuit 16, and a a controller 14, a feedback loop 18 and a cold cathode fluorescent lamp 11. The power supply 12 is controlled by the controller 14 to provide a DC voltage V to
CC 該CCFL驅動電路16。該CCFL驅動電路16係一自我共振電 路’如已知之Royer電路，即為一自我震盪式直流變交流 轉換器。例如，該CCFL驅動電路16可包含一變壓器161 093120631 表單編號A0101 第4頁/共22頁 1003488304-0 1361022 |10°0年12月29日修正 、一第一與第二開關組31、S2及一開關控制電路163。該 變壓器1 61係具有主要線圈及次要線圈。該電源供應器12 係耦合至該變壓器161之主要線圈。該第一及第二開關組 、S2係連接在該變壓器之主要線圈及接地間，以分別 定義第一導通路徑及第二導通路徑。該開關控制電路163 ’係耦合至該第一開關組Si及第二開關組s2，用以控制 該第一開關組Si及第二開關組s2之交互導通，而以分別 形成該第一導通路徑及第二導通路徑。而該冷陰極螢光 燈11係經由電容C。耦合至該變壓器161之次要線圈。該回 授迴路18係耦合該冷陰極螢光燈11之負載，而以產生一 回授信號FB至該控制器14。該控制器14包含有一比較器 15及一脈寬調變電路π (pulse-Width Modulator， PWM )。該比較器丨5係接收該回授信號FB，並輸出一控 制信號CN至該脈寬調變電路17。該脈寬調變電路17用以 接收該控制信號CN，而調節輸入至該開關控制電路163之 時脈信號寬度，以經由該開關控制電路163控制該第一開 關及第二開關組8丨、S2之交互導通，而調整該變壓器161 輸出至該冷陰極螢光燈丨丨之交流電壓。 [0005] 如第二圖所示，該脈寬調變電路17調節脈寬之運作大致 如下：該脈寬調變電路17係由一時脈設定器24及一震盪 器22產生一具有脈寬為l之時脈信號，且藉由故變該脈寬 L之大小’以改變輸送至該冷陰極螢光燈η之交流電壓， 如此達到調節該冷陰極螢光燈11之明暗度。該時脈設定 器24係接收由該比較器15所輸出之控制信號CN，而以向 上平移或向下平移該直流信號線3〇來改變直流信號DC之 093120631 表單編號A0101 第5頁/共22頁 1003488304-0 1361022 100年12月29日修正替换頁 值。同時，該震盪器22係產生一具有固定頻率之三角波 34 (triangular wave)，該直流信號線30施加至該三 角波34上，以使該直流信號線30分別與每一三角波34之 上升沿25a、25c及下降沿25b形成交點，由此而定義出 該時脈信號之上升沿及下降沿，而以輸出該具有脈寬為L 之時脈信號36。假定將該直流信號線30向上升高，即由 相互之交點形成脈寬更窄之時脈信號，則使該冷陰極螢 光燈11變暗，而若將該直流信號線30向下降低，即由相 互之交點形成脈寬更寬之時脈信號，而使該冷陰極螢光 燈11變亮。因此，上述之回授迴路以產生回授信號FB， 例如表徵流經該冷陰極螢光燈11之電流信號，並以輸入 至該比較器15，甴比較器15將該回授信號FB與一參考值 REF進行比較處理，該參考值REF可為冷陰極螢光燈11之 預設明暗度，並以根據該比較差值而輸出控制信號CN， 藉由該控制信號CN之控制而使該直流信號線30作上下之 移動，如此之回授控制使該冷陰極螢光燈11調整至預設 之亮度。 [0006] 類似之冷陰極螢光燈驅動系統可參見美國專利第 6, 501，234、6, 396, 722號，台灣專利公告第423204、 502928及485701號等。該等冷陰極螢光燈驅動系統中回 授信號FB及控制信號CN等皆為類比信號以作為驅動控制 信號。然，因類比信號較易受到外界之影響，如各個冷 陰極螢光燈間之特性差異、LCD機械結構上之不同、操作 溫度上之變化及供應電源有波動等影響，而使其控制效 果達不到預期之效果。而且，以類比信號作為控制信號 093120631 表單编號A0101 第6頁/共22頁 1003488304-0 I361Q22 I 100年.12月29日梭正_^頁 之驅動系統，通常不能適應現代高端之數位電子裝置， 如計算機等進行進一步處理，其僅能有限地控制冷陰極 螢光燈之使用狀態，如僅控制單一冷陰極螢光燈在一定 期間之亮和暗狀態等。如若控制一個以上冷陰極螢光燈 ’與之匹配之電路設計將更趨複雜，亦更耗費生產之成 本’且不易適應性地根據需要來設定不同之控制操作， 如控制一俩以上冷陰極螢光燈之亮、暗或亮暗時間長短 及亮暗程度等各種不同情形。 [0007] 而另一方面，上述之冷陰極螢光燈驅動系統一般係在一 電路板上搭建達成各個功能之分離元件所構成，而未將 各個功能加以集成或模組化，如此將佔用電路板之較大 面積，惟與現今微型化時代，以節省更多布設空間來容 納更多功能元件之情形相背道而驰〇且，該驅動裝置之 生產’係因需在該電路板上組裝大量之分離元件，而將 耗費大量之時間、人力及物力，遂大大提高該等驅動系 統之生產成本。 [0008] 因此，實有必要提供一種冷陰極螢光燈電源驅動系統， 以數位化驅動冷陰極螢光燈，而以有效減少佔用電路板 之空間並降低該驅動電路板之生產成本下，使冷陰極螢 光燈達到所需之使用狀況。 【發明内容】 [0009] 為克服上述之缺點及其他之目的，本發明之一目的在於 提供一種冷陰極螢光燈電源驅動系統，以數位化驅動冷 陰極螢光燈，而使冷陰極螢光燈達到預設之使用狀況。 本發明之二目的在於提供一種冷陰極螢光燈電源驅動系 093120631 表單編號A0101 第7頁/共22頁 1003488304-0 [0010] 1361022 100年.12月29日梭正替換頁 統，係以集成化該驅動系統，而大大降低該驅動系統之 生產成本。 [0011] 本發明之三目的在於提供一種冷陰極螢光燈電源驅動系 統，係以集成化該驅動系統，而大大減少該驅動系統電 路板之佔設空間。 [0012] 本發明之冷陰極螢光燈電源驅動系統，係包括一冷陰極 螢光燈，一電壓供應電路，一感測電路及一回授控制器 。其中，電壓供應電路提供一電壓至一冷陰極螢光燈， 該電壓供應電路包括變壓器單元、複數開關組及開關控 制電路，該開關控制電路包含若干驅動器，耦合至該複 數開關組。該感測電路包括一感測阻抗，係感測流經該 冷陰極螢光燈之電流，形成一回授信號。該回授控制器 包括一類比數位轉換器，一數位控制電路及一時脈產生 電路。其中，類比數位轉換器用於接收該回授信號，並 將該回授信號轉換生成一數位式回授信號。數位控制電 路，包括一比較器及一控制單元，該比較器係用以比較 由該類比數位轉換器所輸出之數位式回授信號及一參考 信號，而以輸出一比較信號。該控制單元，係以接收該 比較信號，而輸出一數位調制信號。該時脈產生電路， 包括一正弦波產生器、一三角波產生器、一乘法器、一 調制器及一時鐘產生器，該乘法器係以接收該數位調制 信號及正弦波產生器產生的一正弦波信號，並輸出幅值 已調節的正弦波信號；該調制器係以接收由該乘法器輸 出之幅值已調節之正弦波信號及三角波產生器產生的一 三角波信號，根據該正弦波信號及該三角波信號產生一 093120631 表單編號A0101 第8頁/共22頁 1003488304-0 1361022 100年.12月29日核正齊換頁 脈寬可調的第一時脈信號，該時鐘產生器用於產生一第 二時脈信號，與該調制器輸出之第一時脈信號共同輸入 至該開關控制電路，並由該時鐘產生器進行時序之控制 ，而使與該驅動器連接之複數開關組以預定方式交互導 通，以調整該電壓供應電路輸出至該冷陰極螢光燈之電 壓。如此調整輸入至該冷陰極螢光燈之交流電壓，使該 冷陰極螢光燈達至預期之使用狀態，如需要可以設定單 一冷陰極螢光燈在不同期間内達成不同之發光程度，或 多個冷陰極螢光燈之不同運作狀況等。 [0013] 本發明之優點在於，該冷陰極螢光燈電源驅動系統以數 位化控制冷陰極螢光燈之運作狀況，且該用以數位控制 之控制器係集成在一晶片中，以減少該冷陰極螢光燈數 位驅動系統之電路板佔設空間外，更降低其生產成本。 【實施方式】 [0014} 如第三圖所示，係為本發明冷陰極螢光燈電源驅動系統 之電路圖。其中，圖中僅繪示單個冷陰極螢光燈，亦不 受限於多個冷陰極螢光燈以適當方式設置，如在使用冷 陰極螢光燈之大型面板（CCFL Panel)中。且，本發明 之電源驅動系統也可應用於類似於冷陰極螢光燈之負載 中，及其他合適之特定用途中，在此並非有所限制。 [0015] 該冷陰極螢光燈電源驅動系統40包括一電壓供應電路42 、一感測電路44、一回授控制器46及一冷陰極螢光燈41 〇 [0016] 093120631 該電壓供應電路42用以輸入一直流電壓V ，並經由該回CC The CCFL drive circuit 16. The CCFL drive circuit 16 is a self-resonant circuit, such as the known Royer circuit, which is a self-oscillating DC-to-AC converter. For example, the CCFL driving circuit 16 can include a transformer 161 093120631 Form No. A0101 Page 4 / Total 22 pages 1003488304-0 1361022 | 10° 0 December 29 correction, a first and second switch group 31, S2 and A switch control circuit 163. The transformer 1 61 has a primary coil and a secondary coil. The power supply 12 is coupled to the primary coil of the transformer 161. The first and second switch groups S2 are connected between the main coil of the transformer and the ground to define a first conduction path and a second conduction path, respectively. The switch control circuit 163' is coupled to the first switch group Si and the second switch group s2 for controlling the mutual conduction of the first switch group Si and the second switch group s2 to form the first conductive path respectively. And a second conduction path. The cold cathode fluorescent lamp 11 is passed through a capacitor C. A secondary coil coupled to the transformer 161. The feedback loop 18 couples the load of the cold cathode fluorescent lamp 11 to generate a feedback signal FB to the controller 14. The controller 14 includes a comparator 15 and a pulse width modulation circuit π (pulse-Width Modulator, PWM). The comparator 丨5 receives the feedback signal FB and outputs a control signal CN to the pulse width modulation circuit 17. The pulse width modulation circuit 17 is configured to receive the control signal CN and adjust a clock signal width input to the switch control circuit 163 to control the first switch and the second switch group 8 via the switch control circuit 163. The interaction of S2 is turned on, and the AC voltage outputted by the transformer 161 to the cold cathode fluorescent lamp is adjusted. As shown in the second figure, the pulse width modulation circuit 17 adjusts the pulse width as follows: the pulse width modulation circuit 17 is generated by a clock setter 24 and an oscillator 22. The clock signal having a width of 1 is changed, and the magnitude of the pulse width L is changed to change the alternating voltage supplied to the cold cathode fluorescent lamp η, thereby adjusting the brightness of the cold cathode fluorescent lamp 11. The clock setter 24 receives the control signal CN outputted by the comparator 15 and shifts the DC signal line 3〇 to translate upward or downward to change the DC signal DC 093120631 Form No. A0101 Page 5 of 22 Page 1003488304-0 1361022 December 29, 100 Corrected the replacement page value. At the same time, the oscillator 22 generates a triangular wave 34 having a fixed frequency, and the DC signal line 30 is applied to the triangular wave 34 such that the DC signal line 30 and the rising edge 25a of each triangular wave 34 are respectively 25c and the falling edge 25b form an intersection point, thereby defining a rising edge and a falling edge of the clock signal, and outputting the clock signal 36 having a pulse width L. Assuming that the DC signal line 30 is raised upward, that is, a clock signal having a narrower pulse width is formed by the intersection point of each other, the cold cathode fluorescent lamp 11 is darkened, and if the DC signal line 30 is lowered downward, That is, the clock signal having a wider pulse width is formed by the intersection point of each other, and the cold cathode fluorescent lamp 11 is brightened. Therefore, the feedback loop described above generates a feedback signal FB, for example, a current signal flowing through the cold cathode fluorescent lamp 11, and is input to the comparator 15, and the comparator 15 outputs the feedback signal FB The reference value REF is compared, and the reference value REF may be a preset brightness of the cold cathode fluorescent lamp 11, and the control signal CN is output according to the comparison difference, and the DC is controlled by the control signal CN. The signal line 30 is moved up and down, and the feedback control causes the cold cathode fluorescent lamp 11 to be adjusted to a preset brightness. [0006] A similar cold cathode fluorescent lamp drive system can be found in U.S. Patent Nos. 6,501,234, 6,396,722, Taiwan Patent Publication Nos. 423,204, 502,928 and 485, 701. In the cold cathode fluorescent lamp driving system, the feedback signal FB and the control signal CN are analog signals as driving control signals. However, because the analog signal is more susceptible to external influences, such as the difference in characteristics between the various cold cathode fluorescent lamps, the difference in the mechanical structure of the LCD, the change in operating temperature, and the fluctuation of the power supply, the control effect is up to Less than expected. Moreover, the analog signal is used as the control signal 093120631 Form No. A0101 Page 6 / Total 22 Page 1003488304-0 I361Q22 I 100 years. December 29th, the drive system of the shuttle is usually unable to adapt to the modern high-end digital electronic device. For further processing, such as a computer, it can only control the state of use of the cold cathode fluorescent lamp with limited control, such as controlling only the light and dark states of a single cold cathode fluorescent lamp for a certain period of time. If more than one cold cathode fluorescent lamp is controlled, the matching circuit design will become more complicated and costly to produce. It is not easy to adapt to different control operations according to needs, such as controlling more than one cold cathode firefly. Light, dark or bright and dark time and brightness and other various situations. [0007] On the other hand, the above-mentioned cold cathode fluorescent lamp driving system generally comprises a separate component built on a circuit board to achieve various functions, and the functions are not integrated or modularized, so that the circuit is occupied. The larger area of the board, but in contrast to the current miniaturization era, in the case of saving more layout space to accommodate more functional components, the production of the drive unit is required to assemble a large number of separations on the board. Components, which will consume a lot of time, manpower and material resources, greatly increase the production cost of these drive systems. [0008] Therefore, it is necessary to provide a cold cathode fluorescent lamp power supply driving system to digitally drive a cold cathode fluorescent lamp to effectively reduce the space occupied by the circuit board and reduce the production cost of the driving circuit board. Cold cathode fluorescent lamps achieve the desired conditions of use. SUMMARY OF THE INVENTION [0009] In order to overcome the above disadvantages and other objects, an object of the present invention is to provide a cold cathode fluorescent lamp power supply driving system for digitally driving a cold cathode fluorescent lamp to enable cold cathode fluorescent light. The lamp reaches the preset usage condition. A second object of the present invention is to provide a cold cathode fluorescent lamp power supply system 093120631 Form No. A0101 Page 7 / Total 22 Page 1003488304-0 [0010] 1361022 100. On December 29, the shuttle is replacing the page system, with integration The drive system is reduced, and the production cost of the drive system is greatly reduced. [0011] A third object of the present invention is to provide a cold cathode fluorescent lamp power supply driving system that integrates the driving system and greatly reduces the space occupied by the circuit board of the driving system. [0012] The cold cathode fluorescent lamp power supply driving system of the present invention comprises a cold cathode fluorescent lamp, a voltage supply circuit, a sensing circuit and a feedback controller. Wherein, the voltage supply circuit provides a voltage to a cold cathode fluorescent lamp, the voltage supply circuit comprising a transformer unit, a plurality of switch groups and a switch control circuit, the switch control circuit comprising a plurality of drivers coupled to the plurality of switch groups. The sensing circuit includes a sensing impedance that senses a current flowing through the cold cathode fluorescent lamp to form a feedback signal. The feedback controller includes an analog-to-digital converter, a digital control circuit and a clock generation circuit. The analog digital converter is configured to receive the feedback signal and convert the feedback signal to generate a digital feedback signal. The digital control circuit includes a comparator and a control unit for comparing the digital feedback signal and a reference signal output by the analog converter to output a comparison signal. The control unit receives the comparison signal and outputs a digital modulated signal. The clock generation circuit includes a sine wave generator, a triangular wave generator, a multiplier, a modulator, and a clock generator, the multiplier is configured to receive the digital modulated signal and a sine generated by the sine wave generator a wave signal, and outputting a sine wave signal whose amplitude is adjusted; the modulator is configured to receive a sine wave signal whose amplitude is adjusted by the multiplier and a triangular wave signal generated by a triangular wave generator, according to the sine wave signal and The triangular wave signal generates a 093120631 form number A0101 page 8 / total 22 page 1003488304-0 1361022 100 years. December 29th, the first clock signal of the page pulse width adjustable, the clock generator is used to generate a first The second clock signal is input to the switch control circuit together with the first clock signal outputted by the modulator, and is controlled by the clock generator to perform timing control, so that the plurality of switch groups connected to the driver are mutually conductive in a predetermined manner. To adjust the voltage output from the voltage supply circuit to the cold cathode fluorescent lamp. Adjusting the AC voltage input to the cold cathode fluorescent lamp in such a manner that the cold cathode fluorescent lamp reaches the intended use state, and if necessary, a single cold cathode fluorescent lamp can be set to achieve different illumination levels in different periods, or more Different operating conditions of a cold cathode fluorescent lamp. [0013] An advantage of the present invention is that the cold cathode fluorescent lamp power supply driving system controls the operation state of the cold cathode fluorescent lamp digitally, and the controller for digital control is integrated in a wafer to reduce the The circuit board of the cold cathode fluorescent lamp digital driving system occupies space, which further reduces the production cost. [Embodiment] [0014] As shown in the third figure, it is a circuit diagram of a cold cathode fluorescent lamp power supply driving system of the present invention. In the drawings, only a single cold cathode fluorescent lamp is shown, and is not limited to a plurality of cold cathode fluorescent lamps, such as in a large panel (CCFL Panel) using a cold cathode fluorescent lamp. Moreover, the power drive system of the present invention can also be applied to a load similar to a cold cathode fluorescent lamp, and other suitable specific uses, which are not limited herein. [0015] The cold cathode fluorescent lamp power supply driving system 40 includes a voltage supply circuit 42, a sensing circuit 44, a feedback controller 46, and a cold cathode fluorescent lamp 41. [0016] 093120631 The voltage supply circuit 42 Used to input the DC voltage V and pass the back
CC 授控制器46之控制，而輸出一交流電壓V +至該冷陰極 out 表單編號A0101 第9頁/共22頁 1003488304-0 1361022 100年.12月29日修正替_頁 螢光燈41 ’該電壓供應電路42可以採用自我共振電路， 如已知之Royer電路，或其他合適之驅動電路，以將該直 流輸入電壓vcc轉換成交流輸出電壓^例如，本發明 之該電壓供應電路42可包括變壓器單元421、複數開關組 423及開關控制電路425。該開關控制電路425包括驅動 器1^、D2 ’搞合至該複數開關組423，藉由控制該驅動器 Di、D2，使其中一些開關導通之時另—些開關處於關斷 狀態。該變壓器單元421具有主要線圈及次要線圈，該複 數開關組423及直流輸入電壓V耦合至該主要線圈，該 冷陰極螢光燈41耦合至該次要線圈。需注意的是，該電 壓供應電路42之變壓器單元421、複數開關組423及開關 控制電路425之間可根據需要以適當方式設置，且其中之 變壓器單元421及複數開關組423數目並非有所限制，且 該複數開關組423可為MOSFETs電晶體、BJT電晶體、或 兩者之混合類型及其他合適之開關。 [0017] 该感測電路44係包含一感測阻抗，如本實施例中之電阻 Rs ’抑或電容等，其係電跨接於該冷陰極螢光燈41，以 感測與該冷陰極螢光燈41之使用狀態相關之值，如感測 流經該冷陰極螢光燈41之實際電流，且經由該感測阻抗The CC is controlled by the controller 46, and outputs an AC voltage V + to the cold cathode out Form No. A0101 Page 9 / Total 22 pages 1003488304-0 1361022 100 years. December 29 correction for the _ page fluorescent lamp 41 ' The voltage supply circuit 42 can employ a self-resonant circuit, such as a known Royer circuit, or other suitable drive circuit to convert the DC input voltage vcc into an AC output voltage. For example, the voltage supply circuit 42 of the present invention can include a transformer. Unit 421, complex switch group 423, and switch control circuit 425. The switch control circuit 425 includes drivers 1^, D2' engaged to the complex switch block 423. By controlling the drivers Di, D2, some of the switches are turned "on" while the other switches are in the off state. The transformer unit 421 has a primary coil and a secondary coil, the complex switch bank 423 and a DC input voltage V coupled to the primary coil, the cold cathode fluorescent lamp 41 being coupled to the secondary coil. It should be noted that the transformer unit 421, the complex switch group 423 and the switch control circuit 425 of the voltage supply circuit 42 can be set in an appropriate manner as needed, and the number of the transformer unit 421 and the plurality of switch groups 423 is not limited. And the complex switch group 423 can be a MOSFETs transistor, a BJT transistor, or a hybrid type of the two and other suitable switches. [0017] The sensing circuit 44 includes a sensing impedance, such as the resistor Rs' or the capacitor in the embodiment, which is electrically connected to the cold cathode fluorescent lamp 41 to sense and the cold cathode fluorescent The value associated with the state of use of the light lamp 41, such as sensing the actual current flowing through the cold cathode fluorescent lamp 41, and via the sensing impedance
Rs而成為一感測電壓V ，並以該感測電壓v 作Λ sense sense ^ 回授信號而輸入至該回授控制器46。 [0018] 如此’本發明中該回授控制器46接收由該感測電路44傳 來之信號’而調整該電壓供應電路42輸出至該冷陰極螢 光燈41之交流電壓。本發明之該回授控制器46，其可集 成在一晶片中’也可將其中部分之功能元件加以模組化 093120631 表單編號A0101 第10頁/共22頁 1003488304-0 1361022 [0019] [0020] [0021] [0022] 100年:12月29日梭正_頁 ，以下將具體描述該回授控制器46。 該回授控制器46可包含一類比數位轉換器45 ' —數位控 制電路47及一時脈產生電路49。 該類比數位轉換器45用以接收如該感測電路44所傳來之 類比感測電壓V ncp，並將該類比感測電壓V 予以鳕 sense sense J Λ ^ 換，而以產生一數位回饋信號FB，並以輸入至該數位控 制電路47 » 該數位控制電路47可包括一比較器472及一控制單元474 。該比較器472係接收該數位回饋信號FB及一參考信號 REF ’並由該比較器472將比較結果輸入至該控制單元 474。其中，該參考信號REF表示與該冷陰極螢光燈ο之 使用狀態相關之預期值，如需流經該冷陰極螢光燈41之 預設電流等。其中，該參考信號REF可由人工根據經驗及 需要而設定為合適值，或由内部可程式化控制器提供， 抑或經由外部裝置提供，且該參考信號REF之值可根據不 同之負載特性及其他情形而加p變化，如各冷陰極螢光 燈41之特性差異等β此外，若該冷陰極螢光燈電源驅動 系統40係設置有保護電路（未圖示），則該比較器472可 接收另一參考信號REF’ ，該參考信號REF，係定義為該 冷陰極螢光燈電源驅動系統4〇所允許流過之最大電流或 最小電流，在此不加詳述^ 在理想狀態下，該數位回饋信號FB係等於該參考信號REF 。然而，若該數位回饋信號FB與該參考信號ref不相等， 則由該比較器472產生一比較信號CMP (compared 093120631 表單編號A0101 第11頁/共22頁 1003488304-0 1361022 100年12月29日修正替换頁 value)，即其間之差異值輪入至該控制單元474。該控 制單兀474可主要根據該比較器472所輸出之比較信號值 CMP ’而輸出合適之數位調制信號A (AmpHtude)至該 時脈產生電路49。因此’藉由該比較器472產生之比較信 號CMP ’以確定所需調制之幅度a，而使該時脈產生電路 49產生-合脈寬之時脈信號，以調整輸人至該電壓供 應電路42之電壓’以了將進—步詳細描述。 [0023] 5玄時脈產生電路49係包括—正弦波產生器繼（Sign waveform generator)、一三角波產生器494 (Saw_ tooth generator)、一乘法器496及一調制器498。該 正弦波產生器492係產生一正弦波'n (' =Sin6> )。該 乘法器496之輸入端係同時接收該數位調制信號A及該正 弦波Vin，而在輸出端輸出幅值已調變之正弦波。若上述 之比較信號CMP指示該控制單元輸出為八，則經由該乘法Rs becomes a sensing voltage V, and is input to the feedback controller 46 with the sensing voltage v as a sense sense ^ feedback signal. [0018] Thus, in the present invention, the feedback controller 46 receives the signal transmitted by the sensing circuit 44 and adjusts the AC voltage outputted by the voltage supply circuit 42 to the cold cathode fluorescent lamp 41. The feedback controller 46 of the present invention can be integrated into a wafer. 'A part of the functional components can also be modularized 093120631 Form No. A0101 Page 10 / Total 22 Page 1003488304-0 1361022 [0019] [0020 [0022] [0022] 100 years: December 29th, the feedback controller 46 will be specifically described below. The feedback controller 46 can include an analog to digital converter 45' - a digital control circuit 47 and a clock generation circuit 49. The analog-to-digital converter 45 is configured to receive the analog sense voltage V ncp sent by the sensing circuit 44 and convert the analog sense voltage V by sense sense J Λ ^ to generate a digital feedback signal. FB, and input to the digital control circuit 47 » The digital control circuit 47 can include a comparator 472 and a control unit 474. The comparator 472 receives the digital feedback signal FB and a reference signal REF ' and inputs the comparison result to the control unit 474 by the comparator 472. Here, the reference signal REF indicates an expected value associated with the state of use of the cold cathode fluorescent lamp ο, a predetermined current to flow through the cold cathode fluorescent lamp 41, and the like. Wherein, the reference signal REF can be manually set according to experience and needs to be a suitable value, or provided by an internal programmable controller, or provided by an external device, and the value of the reference signal REF can be different according to different load characteristics and other situations. Further, if p is changed, such as a difference in characteristics of each of the cold cathode fluorescent lamps 41, etc., if the cold cathode fluorescent lamp power supply driving system 40 is provided with a protection circuit (not shown), the comparator 472 can receive another A reference signal REF', which is defined as the maximum current or minimum current allowed by the cold cathode fluorescent lamp power supply driving system 4〇, is not detailed here ^ In an ideal state, the digit The feedback signal FB is equal to the reference signal REF. However, if the digital feedback signal FB is not equal to the reference signal ref, a comparison signal CMP is generated by the comparator 472 (compared 093120631 Form No. A0101 Page 11 / Total 22 Page 1003488304-0 1361022 December 29, 100 The replacement page value is corrected, that is, the difference value therebetween is rounded to the control unit 474. The control unit 474 can output a suitable digital modulation signal A (AmpHtude) to the clock generation circuit 49 based mainly on the comparison signal value CMP' output from the comparator 472. Therefore, the comparison signal CMP' generated by the comparator 472 determines the amplitude a of the desired modulation, and causes the clock generation circuit 49 to generate a clock signal of the pulse width to adjust the input to the voltage supply circuit. The voltage of 42 will be described in detail. [0023] The 5th clock generation circuit 49 includes a sine wave generator (Sign waveform generator), a triangle wave generator 494 (Saw_tooth generator), a multiplier 496, and a modulator 498. The sine wave generator 492 generates a sine wave 'n (' = Sin6>). The input end of the multiplier 496 receives the digital modulated signal A and the sine wave Vin at the same time, and outputs a sine wave whose amplitude has been modulated at the output end. If the comparison signal CMP indicates that the control unit output is eight, then the multiplication is performed.
器之運算，該正弦波之幅值調高至A倍，為v , (V in in ，=ASin0);反之，若該比較信號CMp指示該控制單元 輸出為1/A，則經由該乘法器之運算，該正弦波之幅值減 少至 1/A倍，為Vin’， （Vin，，=1/A Sir^)。該三 角波產生器494可由一具有適當時間常數之電容，以產生 一固定頻率之三角波vm(未圖示）。或者，如第三圖所 示，該三角波產生器494係包括一時鐘產生器495，由該 時鐘產生器495產生方波且經積分器（未圖示）而形成該 三角波Vm。該時鐘產生器495可控制該正弦波產生器492The operation of the sine wave is increased to A times, which is v, (V in in , =ASin0); conversely, if the comparison signal CMp indicates that the control unit output is 1/A, then the multiplier is passed. In the operation, the amplitude of the sine wave is reduced to 1/A times, which is Vin', (Vin,, = 1/A Sir^). The triangular wave generator 494 can be a capacitor having an appropriate time constant to generate a fixed frequency triangular wave vm (not shown). Alternatively, as shown in the third figure, the triangular wave generator 494 includes a clock generator 495 which generates a square wave and forms the triangular wave Vm via an integrator (not shown). The clock generator 495 can control the sine wave generator 492
，使所產生之正弦波V與該時鐘產生器495之三角波V 111 m 具有相同之固定頻率。此外’該時鐘產生器495將產生之 093120631 表單编號A0101 第12頁/共22頁 1003488304-0 1361022 100年.12月29日按正替換頁 時脈信號經由一時脈時序控制電路（未圖示），而與該 調制器498之輸出端共同輸入至該開關控制電路425，如 第三圖所示之驅動器D2，以控制輸入至該驅動器\ 、D2之時脈信號之時序，使複數開關組423以預定方式交 互導通。且該時鐘產生器495抑可為其他外部之時鐘產生 器，在所不限。 [0024] 該調制器498可包含一比較器（未圖示），用以接收該三 角波信號V及由該乘法器496輸入之幅值已調變之正弦波 m ，以輸出脈寬已調制之時脈信號，藉由脈寬之變化，而 調整輸入至該冷陰極螢光燈41之交流電壓。 [0025] 該時脈產生電路49調節脈寬之運作大致如第四（a) - (c )圖所示：The generated sine wave V has the same fixed frequency as the triangular wave V 111 m of the clock generator 495. In addition, the clock generator 495 will generate 093120631 form number A0101 page 12 / total 22 pages 1003488304-0 1361022 100 years. December 29th according to the positive replacement page clock signal via a clock timing control circuit (not shown And input to the switch control circuit 425 together with the output of the modulator 498, such as the driver D2 shown in the third figure, to control the timing of the clock signals input to the drivers \, D2, so that the plurality of switch groups 423 is interactively turned on in a predetermined manner. Moreover, the clock generator 495 can be other external clock generators, and is not limited thereto. [0024] The modulator 498 can include a comparator (not shown) for receiving the triangular wave signal V and the amplitude modulated sine wave m input by the multiplier 496 to output a pulse width modulated The clock signal adjusts the AC voltage input to the cold cathode fluorescent lamp 41 by the change of the pulse width. [0025] The operation of the clock generation circuit 49 to adjust the pulse width is substantially as shown in the fourth (a) - (c) diagram:
[0026] 如第四（a)圖中，該三角波產生器494產生一三角波V m ，而該正弦波產生器492產生正弦波V.並施加至該三角 in 波V上。假定正弦波V.之值大於三角波V時，係定義時 m in m 脈信號V。值為1，而在該正弦波V.值小於或等於該三角 a in 波V時，係定義該時脈信號L值為0 (亦可相反定義上 m α 述之假定），則該正弦波V.依次與該三角波V形成交點 in m a、b、c、d等，以形成如第四（a)圖以二進制0、1進行 編碼之第一時脈信號。 [0027] 如第四（b)圖中，當該正弦波改變為V. ’ （V. ’ in in = ASin0)，即該正弦波曲線向上平移，該正弦波V. ’ in 與該三角波V所得一系列新交點a ’ 、b ’ 、c ’ 、d ’等 m 而形成以二進制〇、1進行編碼之第二時脈信號，且相對 093120631 表單編號Α0101 第13頁/共22頁 1003488304-0 1361022 __ 100年.12月29日按正替«頁 之脈寬已變寬，例如b’與C’兩點間之相對距離已變大 。同樣，如第四（c)圖中，該正弦波減至V. ’ ’ ( inAs shown in the fourth (a) diagram, the triangular wave generator 494 generates a triangular wave V m which is generated by the sine wave generator 492 and applied to the triangular in wave V. Assuming that the value of the sine wave V. is greater than the triangular wave V, the m in m pulse signal V is defined. The value is 1, and when the V. value of the sine wave is less than or equal to the triangle a in wave V, the value of the clock signal L is defined as 0 (may also define the assumption of m α described above), then the sine wave V. sequentially forms an intersection with the triangular wave V in ma, b, c, d, etc. to form a first clock signal encoded as a binary 0, 1 as in the fourth (a) diagram. [0027] As in the fourth (b) diagram, when the sine wave is changed to V. ' (V. ' in in = ASin0), that is, the sine wave curve is translated upward, the sine wave V. 'in and the triangular wave V A series of new intersections a ' , b ' , c ' , d ', etc. m are formed to form a second clock signal encoded by binary 〇, 1 and relative to 093120631 Form No. 101 0101 Page 13 / Total 22 Page 1003488304-0 1361022 __ 100 years. On December 29th, the pulse width of the page has been widened. For example, the relative distance between the two points b' and C' has become larger. Similarly, as in the fourth (c) diagram, the sine wave is reduced to V. ’ ’ (in
Vin’ ’ =1/A Sin0 )時，形成另一脈寬變窄且以數位化 表示之時脈信號。此外，可藉由該正弦波信號與該三角 波信號之適當變化以調制該時脈信號之寬度外，抑可調 制該時脈信號之數量及分布規則等。 [0028] 如此，可由該時脈產生電路49調變該時脈信號，並輸入 至該開關控制電路425，如驅動器D1% D2，並由内部或外 部之時鐘產生器495進行時序之控制，而使與驅動器1^、 D2連接之複數開關組423交互導通，以調整輸入至該冷陰 極螢光燈41之交流電壓。 [0029] 由上所述，藉由該回授控制器46之控制，使該時脈產生 電路49產生已數位化(之時脈信號。且經由上述之時脈信 號數位化處理後，可介入各種計算機程式中之數位邏輯 運算，以進行更多類型之複雜控制，如對單一冷陰極螢 光燈在不同期間之亮暗狀態進行控制；或在其他一些實 施例中，係感測多個冷陰極螢光燈之各種使用狀態，而 分別或同時控制各個冷陰極螢光燈達至所需之運作狀態 ，以達預期之多元化控制。 [0030] 综上所述，本發明符合發明專利要件，爰依法提出專利 申請。惟，以上所述者僅為本發明之較佳實施例，舉凡 熟悉本案技藝之人士，在援依本發明精神所作之等效修 飾或變化，皆應包含於以下之申請專利範圍内。 【圖式簡單說明】 [0031] 第一圖係為習知冷陰極螢光燈驅動系統示意圖。 093120631 表單编號A0101 第14頁/共22頁 1003488304-0 1361022 100年.12月29日按正_頁 [0032] 第二圖係為第一圖中脈寬調變電路之波形信號產生示意 圖。 [0033] 第三圖係為本發明冷陰極螢光燈電源驅動系統之電路圖 〇 [0034] 第四（a) - (c)圖係為第三圖中時脈產生電路之波形信 號產生示意圖。 [0035] 【主要元件符號說明】 冷陰極螢光燈電源驅動系統：40 [0036] 數位控制電路：47 [0037] 陰極螢光燈：41 [0038] 比較器：472 [0039] 電壓供應電路：42 [0040] 控制單元：474 [0041] 變壓器單元：421 [0042] 時脈產生電路：49 [0043] 複數開關組：423 [0044] 正弦波產生器：492 [0045] 開關控制電路：425 [0046] 三角波產生器：494 [0047] 感測電路：44 [0048] 時鐘產生器：495 093120631 表單編號A0101 第15頁/共22頁 . 1003488304-0 1361022 100年12月29日核正替^頁 [0049] 回授控制器：46 [0050] 乘法器：496 [0051] 類比數位轉換器：45 [0052] 調制器：498 1003488304-0 093120631 表單编號A0101 .第16頁/共22頁When Vin' =1 = A Sin0 ), another clock signal whose pulse width is narrowed and which is represented by digitization is formed. In addition, the sinusoidal signal and the appropriate change of the triangular wave signal can be used to modulate the width of the clock signal, and the number and distribution rules of the clock signal can be adjusted. [0028] Thus, the clock signal can be modulated by the clock generation circuit 49 and input to the switch control circuit 425, such as the driver D1% D2, and controlled by the internal or external clock generator 495, and The plurality of switch groups 423 connected to the drivers 1^, D2 are alternately turned on to adjust the AC voltage input to the cold cathode fluorescent lamp 41. [0029] As described above, the clock generation circuit 49 generates the digitalized clock signal by the control of the feedback controller 46, and can be intervened after the clock signal is digitized by the above-described clock signal. Digital logic operations in various computer programs to perform more types of complex control, such as controlling the brightness of a single cold cathode fluorescent lamp during different periods; or in other embodiments, sensing multiple cold Various states of use of the cathode fluorescent lamp, and each of the cold cathode fluorescent lamps are controlled separately or simultaneously to achieve the desired operational state to achieve the desired diversified control. [0030] In summary, the present invention complies with the invention patent requirements 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 Within the scope of patent application. [Simplified illustration] [0031] The first figure is a schematic diagram of a conventional cold cathode fluorescent lamp driving system. 093120631 Form No. A0101 Page 14 of 22 1003488304-0 1 361022 100. December 29, according to the positive page [0032] The second figure is the waveform signal generation diagram of the pulse width modulation circuit in the first figure. [0033] The third figure is the cold cathode fluorescent light of the present invention. Circuit diagram of lamp power supply drive system [0034] The fourth (a) - (c) diagram is a schematic diagram of the waveform signal generation of the clock generation circuit in the third figure. [0035] [Main component symbol description] Cold cathode fluorescent lamp Power drive system: 40 [0036] Digital control circuit: 47 [0037] Cathode fluorescent lamp: 41 [0038] Comparator: 472 [0039] Voltage supply circuit: 42 [0040] Control unit: 474 [0041] Transformer unit: 421 [0042] Clock generation circuit: 49 [0043] Complex switch group: 423 [0044] Sine wave generator: 492 [0045] Switch control circuit: 425 [0046] Triangle wave generator: 494 [0047] Sensing circuit: 44 [0048] Clock Generator: 495 093120631 Form No. A0101 Page 15 of 22. 1003488304-0 1361022 December 29, 100 Nuclear Replacement Page [0049] Feedback Controller: 46 [0050] Multiplier :496 [0051] Analog to digital converter: 45 [0052] Modulator: 498 1003488304-0 093120631 Form No. A0101 . Page 16 of 22
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW93120631A TWI361022B (en) | 2004-07-09 | 2004-07-09 | A driving system to control power supply to a ccfl |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW93120631A TWI361022B (en) | 2004-07-09 | 2004-07-09 | A driving system to control power supply to a ccfl |
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| TW200603681A TW200603681A (en) | 2006-01-16 |
| TWI361022B true TWI361022B (en) | 2012-03-21 |
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| TW93120631A TWI361022B (en) | 2004-07-09 | 2004-07-09 | A driving system to control power supply to a ccfl |
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