Source: https://patents.google.com/patent/US20050105305A1/en
Timestamp: 2019-12-06 05:22:36
Document Index: 141932127

Matched Legal Cases: ['arts 109', 'art 109', 'arts 109', 'art 109', 'art 109', 'art 109', 'arts 109', 'art 109', 'art 109', 'arts 109']

US20050105305A1 - Drive system and AC conversion device - Google Patents
Drive system and AC conversion device Download PDF
US20050105305A1
US20050105305A1 US10/953,490 US95349004A US2005105305A1 US 20050105305 A1 US20050105305 A1 US 20050105305A1 US 95349004 A US95349004 A US 95349004A US 2005105305 A1 US2005105305 A1 US 2005105305A1
US10/953,490
US7315464B2 (en
Takeaki Ogawa
2003-10-03 Priority to JPP2003-346014 priority Critical
2003-10-03 Priority to JP2003346014 priority
2004-06-22 Priority to JP2004183809A priority patent/JP2005129004A/en
2004-06-22 Priority to JPP2004-183809 priority
2004-09-30 Application filed by Sharp Corp, Sharp Niigata Electronics Corp filed Critical Sharp Corp
2005-01-24 Assigned to SHARP KABUSHIKI KAISHA, SHARP NIIGATA ELECTRONICS CORPORATION reassignment SHARP KABUSHIKI KAISHA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: OGAWA, TAKEAKI, SAWADA, SHINICHI, TANAKA, NAOKI
2005-05-19 Publication of US20050105305A1 publication Critical patent/US20050105305A1/en
2008-01-01 Publication of US7315464B2 publication Critical patent/US7315464B2/en
238000006243 chemical reaction Methods 0 abstract claims description title 274
The DC conversion device 23 acquires commercial AC power, converts the commercial AC power into converted DC power having a predetermined voltage, and gives the converted DC power to the respective DC drive devices 24 a to 24 c. Note that, hereinafter, the respective DC drive devices 24 a to 24 c may be collectively referred to as the DC drive devices 24. The DC drive devices 24 are devices that are driven by converted DC power. The DC drive devices 24 are, for example, an image processing circuit 24 a, a liquid crystal driver 24 b, and a speaker 24 c. In this way, the AC conversion device 21 and the DC conversion device 23 serve as power supply devices that convert the supplied AC power and give the supplied AC power to the respective drive devices 22 and 24 a to 24 c.
In the case in which the liquid crystal display device 20 is a television receiver, the television receiver receives image data and voice data with a receiver. In addition, in the case in which the liquid crystal display apparatus 20 is a personal computer, the personal computer generates image data and voice data with a CPU (Central Processing Unit). In this way, the liquid crystal display apparatus 20 acquires image data, which should be displayed, and voice data with some acquiring means and gives the acquired image data to the image processing circuit 24 a. The image processing circuit 24 a generates a pixel signal according to the given image data. The pixel signal is generated for each pixel constituting an image represented by the image data. The image processing circuit 24 a is realized by, for example, an LSI (Large-Scale Integration).
One terminal 65 of the secondary winding 64 of the first transformer T1 is connected to one terminals 68 of primary windings 67 of the secondary transformers T2 and T3 by a fifth line 66. In addition, the other terminal 69 of the secondary winding 64 of the first transformer T1 is connected to the other terminals 71 of the primary windings 67 of the second transformers T2 and T3 by a sixth line 70. Note that, in FIG. 4, leakage inductances present in secondary windings 73 of the second transformers T2 and T3 are denoted by reference numeral 73 a.
In the case in which the plurality of second transformers T2 and T3 are provided, the fifth line 66 and the sixth line 70 are branched into a plurality of lines and connected to two terminals 68 and 71 of the primary windings 67 of the second transformers T2 and T3. In addition, in the fifth line 66, a branching point 130, where the fifth line 66 is branched, is formed according to the number of the second transformers T2 and T3.
The DC conversion device 23 subjects AC power given from the AC commercial power supply 25 to full-wave rectification with the rectifier 40. In addition, the DC conversion device 23 improves a power factor at the time when the AC power is converted into DC power subjected to the full-wave rectification with the power-factor improving circuit 42 and smoothes the AC power with the smoothing capacitor 41 and converts the AC power into DC power. Then, the DC conversion device 23 converts the DC power into high-frequency AC power with the second alternating power generating circuit 36 and transforms the high-frequency AC power with the third transformer T4. Then, the DC conversion device 23 converts the transformed AC power into DC power with the third DC power generating circuit 38 to generate desired converted DC power. Then, the DC conversion device 23 gives the generated converted DC power to the respective DC drive devices 24 a to 24 c.
Such a DC conversion device 23 is realized by, for example, a switching power supply circuit. The switching power supply circuit takes root as a basic unit and has a function of supplying DC stabilized power from a commercial power supply. Note that, in accordance with a safety standard set in advance, conditions for insulation of a primary winding and a secondary winding are set for the third transformer T4 in advance. Therefore, the DC conversion device 23 can give DC power electrically insulated against the commercial power supply 25 to the respective DC drive devices 24 a to 24 c. In this way, the AC conversion device 21 of the invention is a device obtained by combining a power supply device and an inverter device for the discharge tubes 22 for lighting a backlight of the liquid crystal display apparatus 20.
Since the DC power supply path 102 and the AC power supply path 101 are provided separately, even if power consumption of the liquid crystal display apparatus 20 increases in accordance with an increase in size and an increase in number of the discharge tubes 22, it is possible to prevent power from concentrating on the DC conversion device 23. Therefore, even if power consumption of the discharge tubes 22 increases, it is unnecessary to increase allowable power of the DC conversion device 23 and the respective DC drive devices 24 a to 24 c, and it is possible to prevent an increase in size of the DC conversion device 23 and the respective DC drive devices 24 a to 24 c.
FIG. 6 is a block diagram showing a liquid crystal display apparatus 200 of a comparative example. In the liquid crystal display apparatus 200 of the comparative example, a first power supply path 201 for supplying power to the discharge tubes 22 and a second power supply path 202 for supplying power to the respective DC drive devices 24 a to 24 c are provided independently. In the liquid crystal display apparatus 200 of the comparative example, an electric power system is simply divided into two systems, and the DC conversion device 3 and the inverter device 4, which are the same as those in the related art, are provided in the first power supply path 201. In this case, although it is possible to prevent concentration of power on the DC conversion device 23 of the second power supply path 202, the same problems as those in the related art occur.
In the case in which a drive power for the discharge tubes 22 is set to 70 W, when it is assumed that power obtained by subtracting power supplied to the discharge tubes 22 from commercial AC power inputted from the commercial power supply 25 is internal loss power, the internal loss power is about 23 W in the liquid crystal display apparatus 200 of the comparative example. On the other hand, the internal loss power is about 15 W in the liquid crystal display apparatus 20 of the invention. Therefore, in the liquid crystal display apparatus 20 of the invention, it is possible to realize reduction in lost power of 8 W compared with the liquid crystal display apparatus 200 of the comparative example. For example, in a television having a large-sized liquid crystal monitor, drive power for the discharge tubes 22 is 60 to 100 W or more, and it is possible to attain the advantages of the invention sufficiently.
The leakage inductances 73 a are provided in the secondary windings 73 of the second transformers T2 and T3. Consequently, in the voltage converting unit 31, an L•C series resonance circuit is constituted by the leakage inductances 73 a and the capacitors for waveform rectification 80. In other words, low-pass filter circuit parts are constituted. Consequently, it is possible to attenuate a harmonic component of a current flowing in the seventh line 75 and the eighth line 78. Moreover, an electrostatic capacity of the capacitors 80 and an inductance value of the secondary windings 73 are set appropriately, whereby, even if the first alternating power generating circuit 33 outputs power of a rectangular waveform, it is possible to bring a waveform of an AC voltage given to the discharge tubes 22 close to a sine waveform. In addition, actually, parasitic capacities are present between the respective discharge tubes 22 and adjacent conductors. Therefore, even if the second connection lines 28 and the capacitors for waveform rectification are not provided, low-pass filters may be realized by the parasitic capacities and the leakage inductances 73 a.
The discharge tubes 22 are driven stably as AC voltage of a sine waveform is applied thereto. Therefore, the low-pass filters are constituted closer to the discharge tubes 22 as described above. Consequently, even if a harmonic component is superimposed from the first alternating power generating circuit 33 to the discharge tubes 22 and even if the first alternating power generating circuit 33 outputs alternating power of a rectangular waveform, it is possible to stabilize operations of the discharge tubes 22.
n≦V in ×T on×109/(2×S×ΔB m)
As shown in FIG. 7, the control IC IC1 adjusts the ON/OFF ratio of the switching element Tr1 on the basis of a potential difference between the two output terminals 53 and 56 of the first DC voltage generating circuit 32. Consequently, even in the case in which a voltage fluctuates in given AC power, the active filter circuit can output stable power. As shown in FIG. 8, for example, even if an effective value of a commercial voltage fluctuates at 100 to 240 Vrms, the active filter circuit can maintain a voltage of a DC current, which is outputted from the first DC voltage generating circuit 32 and given to the first alternating power generating circuit 33, at 380V. Note that it is possible to set a voltage, which the active filter circuit is capable of outputting, arbitrarily as long as the voltage is equal to or larger than a square root of an inputted commercial power supply voltage (commercial power supply voltage×{square root}2).
The switching elements Tr2 and Tr3 are connected to the respective branched parts 109 a and 109 b of the fifteenth line 109 in series. In an ON state, one switching element Tr2 brings the corresponding branched part 109 a of the fifteenth line 109 into a connected state to short-circuit the other input terminal 57 and one both-end output terminal 59 connected to the branched parts 109 a. In an OFF state, one switching element Tr2 brings the corresponding branched part 109 a of the fifteenth line 109 into a blocked state to open the other input terminal 57 and one both-end output terminal 59 connected to the branched part 109 a. The same holds true for the other switching element Tr3. That is, In an ON state, the other switching element Tr3 brings the corresponding branched part 109 b of the fifteenth line 109 into a connected state to short-circuit the other input terminal 57 and the other both-end output terminal 60 connected to the branched parts 109 b. In an OFF state, the other switching element Tr3 brings the corresponding branched part 109 b of the fifteenth line 109 into a blocked state to open the other input terminal 57 and the other both-end output terminal 60 connected to the branched part 109 b.
The first alternating power generating circuit 33 has a fourth connection line 111 that connects the branched parts 109 a and 109 b of the fifteenth line 109 in a position closer to the output terminal than the respective switching elements Tr2 and Tr3. The capacitor C2 is interposed in the fourth connection line 111 and is connected to the fourth connection line 111 in series. The control IC IC2 associates the two switching elements Tr2 and Tr3 with each other to adjust an ON/OFF ratio thereof such that a predetermined frequency is obtained. When the control IC IC2 brings one of the two switching elements Tr2 and Tr3 into an ON state, the control IC IC2 brings the other into an OFF state. Note that the control IC IC1 for power-factor improving circuit and the control IC IC2 for the first alternating power generating circuit are provided independently from each other.
In this embodiment, the bypass line 95 is connected to a position that is apart from one end portion by a distance obtained by dividing the coil-like portion of the primary winding 61 of the first transformer T1 into four. In other words, the tap for connecting the bypass line is provided in a position apart from one end portion of the primary winding 61 by ¼ of a dimension in a winding stacking direction of the primary winding 61. Consequently, it is possible to lower a potential difference at both ends of the inductor for current superimposition 97 and to reduce a size of the inductor for current superimposition 97 as much as possible.
2. The drive system of claim 1, wherein the voltage converting unit includes:
3. The drive system of claim 1, wherein the voltage converting unit is realized by a single transformer for transforming a voltage of alternating power generated by the alternating power generating circuit for AC conversion and generating converted AC power electrically insulated against an AC power supply.
4. The drive system of claim 1, wherein the DC conversion device includes:
5. The drive system of claim 1, wherein the DC conversion device includes:
6. The drive system of claim 1, wherein the voltage converting unit includes:
7. The drive system of claim 1, wherein the voltage converting unit further has a filter circuit part for attenuating a harmonic component of frequency components included in the AC power outputted from the frequency converting unit.
8. The drive system of claim 1, wherein the voltage converting unit includes:
9. The drive system of claim 1, wherein the frequency converting unit further has a power-factor improving circuit for improving a power factor at the time when the supplied AC power is converted into DC power by the DC power generating circuit for AC conversion.
10. The drive system of claim 1, wherein the drive system is a liquid crystal display apparatus that is given AC power and drives discharge tubes.
11. An AC conversion device provided in the drive system of claim 1.
12. An AC conversion device for acquiring AC power from an AC power supply and converting the supplied AC power into converted AC power having a predetermined frequency and a predetermined voltage, the AC conversion device comprising:
US10/953,490 2003-10-03 2004-09-30 Drive system and AC conversion device Active 2025-08-17 US7315464B2 (en)
JPP2003-346014 2003-10-03
JP2003346014 2003-10-03
JP2004183809A JP2005129004A (en) 2003-10-03 2004-06-22 Driving system and a.c. converter
JPP2004-183809 2004-06-22
US20050105305A1 true US20050105305A1 (en) 2005-05-19
US7315464B2 US7315464B2 (en) 2008-01-01
ID=34575890
US10/953,490 Active 2025-08-17 US7315464B2 (en) 2003-10-03 2004-09-30 Drive system and AC conversion device
US (1) US7315464B2 (en)
JP (1) JP2005129004A (en)
CN (1) CN1606395B (en)
US20080303447A1 (en) * 2007-03-20 2008-12-11 Rohm Co., Ltd. Inverter apparatus
JP2010148348A (en) * 2008-12-16 2010-07-01 General Electric Co <Ge> System and method of providing power converter
US20100321369A1 (en) * 2008-02-20 2010-12-23 Sharp Kabushiki Kaisha Backlight device and display equipped with the device
US20120248980A1 (en) * 2011-03-28 2012-10-04 Delta Electronics, Inc. Multi-output electronic ballast
CN103034272A (en) * 2012-12-11 2013-04-10 瑞安市工泰电器有限公司 Electricity intelligent measuring and controlling device
EP2632036A1 (en) * 2012-02-24 2013-08-28 Moxtek, Inc. Small size power supply
US9413247B2 (en) 2013-07-10 2016-08-09 Osram Gmbh Signal transmission method and related device
US20170070163A1 (en) * 2015-09-03 2017-03-09 Majid Pahlevaninezhad High efficiency inverter for distributed generation
JP4811036B2 (en) * 2006-02-02 2011-11-09 富士電機株式会社 PWM control circuit for power converter
CN101060740B (en) 2006-04-21 2011-03-23 鸿富锦精密工业（深圳）有限公司;鸿海精密工业股份有限公司 Discharge lamp drive device
US20080049461A1 (en) * 2006-08-23 2008-02-28 &Zippy Technology Corp. Power supply having multiple power output
JP2008117550A (en) * 2006-11-01 2008-05-22 Matsushita Electric Ind Co Ltd Power supply device for driving high-voltage discharge tube, and liquid crystal display unit using the same
JP5132989B2 (en) * 2007-05-21 2013-01-30 株式会社三社電機製作所 Power supply device for arc generating load
JP2009099388A (en) * 2007-10-17 2009-05-07 Minebea Co Ltd Discharge lamp lighting device
CN101826803B (en) 2009-03-06 2012-09-05 中华映管股份有限公司 Independent power supply module of liquid crystal display
CN101833929B (en) * 2010-05-11 2012-07-11 福建捷联电子有限公司 Single-string LED lamp tube push-pull type direct-current high-voltage drive circuit of liquid-crystal display
JP5929667B2 (en) * 2012-09-25 2016-06-08 富士ゼロックス株式会社 Image forming apparatus and bias power supply apparatus
KR101278125B1 (en) * 2013-05-07 2013-06-25 이상철 Dimming control apparatus using sensing of volts alternating current in power line communication
US6600273B2 (en) * 2000-12-23 2003-07-29 Samsung Electro-Mechanics Co., Ltd. High-power electronic ballast for fluorescent lamp
JPS635996B2 (en) 1979-12-19 1988-02-06 Toshiba Electric Equip
DE3132943A1 (en) 1981-08-20 1983-03-03 Licentia Gmbh Tuning system for high-frequency receiving geraete
JPH05137326A (en) 1991-11-11 1993-06-01 Nec Corp Flyback type switching regulator
DE69307427T2 (en) 1992-08-20 1997-07-17 Philips Electronics Nv Verschaltgerät for a lamp
JPH06197555A (en) 1992-12-25 1994-07-15 Taiyo Yuden Co Ltd Lamp turn-on circuit
JP3513515B2 (en) 1996-06-11 2004-03-31 シャープ新潟電子工業株式会社 CCFL drive circuit
JP3273161B2 (en) 1996-06-11 2002-04-08 シャープ新潟電子工業株式会社 Load driving circuit
JP3513613B2 (en) 1998-06-27 2004-03-31 ハリソン東芝ライティング株式会社 Backlight for a discharge lamp lighting device
JP4313016B2 (en) 2002-10-09 2009-08-12 シャープ新潟電子工業株式会社 Switching power supply
2004-06-22 JP JP2004183809A patent/JP2005129004A/en active Pending
2004-09-30 US US10/953,490 patent/US7315464B2/en active Active
2004-09-30 CN CN 200410095103 patent/CN1606395B/en active IP Right Grant
US9935562B2 (en) * 2015-09-03 2018-04-03 Sparq Systems Inc. High efficiency inverter for distributed generation
CN1606395B (en) 2010-06-09
JP2005129004A (en) 2005-05-19
US7315464B2 (en) 2008-01-01
CN1606395A (en) 2005-04-13
US7250726B2 (en) 2007-07-31 Systems and methods for a transformer configuration with a tree topology for current balancing in gas discharge lamps
EP0498651A2 (en) 1992-08-12 High power factor power supply
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAWADA, SHINICHI;OGAWA, TAKEAKI;TANAKA, NAOKI;REEL/FRAME:016202/0689