WO1990014625A1 - Power source circuit - Google Patents
Power source circuit Download PDFInfo
- Publication number
- WO1990014625A1 WO1990014625A1 PCT/JP1990/000672 JP9000672W WO9014625A1 WO 1990014625 A1 WO1990014625 A1 WO 1990014625A1 JP 9000672 W JP9000672 W JP 9000672W WO 9014625 A1 WO9014625 A1 WO 9014625A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- circuit
- power supply
- voltage
- output
- mode control
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G05F5/00—Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
- G05F1/10—Regulating voltage or current
- G05F1/46—Regulating voltage or current wherein the variable actually regulated by the final control device is dc
- G05F1/56—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices
- G05F1/59—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices including plural semiconductor devices as final control devices for a single load
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
- G05F1/10—Regulating voltage or current
- G05F1/46—Regulating voltage or current wherein the variable actually regulated by the final control device is dc
- G05F1/62—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using bucking or boosting dc sources
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
- G09G2330/02—Details of power systems and of start or stop of display operation
Definitions
- the present invention relates to a power supply circuit that outputs a plurality of output voltages having different voltage values to a load, such as a power supply circuit used for a liquid crystal display device, and particularly to a measure to be taken when the power supply voltage drops.
- a conventional power supply circuit of a liquid crystal display circuit has a constant voltage circuit that sends out a constant output voltage regardless of the level of the power supply voltage, and a combination of different voltage values by stepping up and down the output voltage of the constant voltage circuit. It consists of a step-up / step-down circuit that sends out a number of output voltages, and the multiple output voltages are supplied to the LCD panel as drive voltages and driven.
- the conventional power supply circuit of the Kinzoku table circuit cannot maintain the LCD display quality with low power consumption over a wide power supply voltage range.
- the constant voltage circuit generates a 2 V liquid crystal drive voltage
- the buck-boost circuit uses this 2 V liquid crystal drive voltage as a reference
- the power supply voltage is set to 1 V. Until the power drops, the display quality of the liquid crystal panel is maintained, but the charge and discharge of the capacitor causes a large loss of electric current and increases the current consumption. There was a problem that the life of the battery was shortened. Disclosure of the invention
- the power supply circuit includes a constant voltage circuit that outputs a voltage corresponding to a predetermined mode control signal, and a constant voltage circuit that outputs an output voltage of the constant voltage circuit at a rate based on the predetermined mode control signal.
- a step-up / step-down circuit for stepping up or stepping down and sending out a plurality of different output voltages.
- the outputs of the constant voltage circuit and the Z or step-up / step-down circuit are supplied as a liquid crystal drive voltage to a load, for example, a liquid crystal drive circuit that drives a liquid crystal display panel.
- the power supply voltage judgment circuit compares the power supply voltage with a predetermined reference voltage, and outputs a mode control signal corresponding to the comparison result.
- the corresponding mode control signal is sent to the constant voltage circuit and the step-up / step-down circuit.
- the constant voltage circuit outputs a high voltage corresponding to the mode control signal, and the step-up / step-down circuit boosts or steps down the high output voltage at a predetermined ratio to output a plurality of voltages. .
- the constant voltage circuit If it is determined that the power supply voltage is low, the constant voltage circuit outputs a low voltage corresponding to the mode control signal at that time, and the buck-boost circuit outputs a low output voltage.
- the voltage is boosted or stepped down at a different rate from the above case to output a plurality of voltages. Then, the output of the whole of the constant voltage circuit and the step-up / step-down circuit at this time is the same as when it is determined that the power supply voltage is the same or higher.
- the heavy load detection circuit knows the load connected to the power supply in advance, so if a load that corresponds to a heavy load is driven, the mode corresponding to the drive Outputs control signal.
- the current consumption is a dog, and the voltage drop due to the internal resistance of the power supply, that is, the battery, becomes large, and the power supply voltage drops.
- the power supply voltage must be reduced before the power supply voltage actually decreases. Perform the same processing as when Therefore, in the present invention, the output of the constant voltage circuit is increased when the power supply voltage is high, and the constant voltage circuit is increased when the power supply voltage is low or a heavy load is driven.
- the output of the buck-boost circuit is reduced by lowering the output of the buck-boost circuit to make the voltage supplied to the load the same, so that the load is not affected by fluctuations in the power supply voltage. It can be driven stably.
- the constant voltage circuit outputs a low voltage only when the power supply voltage is lower than the reference voltage or when a heavy load is driven, and outputs a high voltage otherwise. As a result, it is possible to drive the load with low power consumption as a whole, and if a battery is used as the power supply, the life can be extended.
- FIG. 1 is a block diagram showing an example in which a power supply circuit according to one embodiment of the present invention is used as a power supply for driving a liquid crystal display panel.
- FIG. 2 is a circuit diagram of the constant voltage circuit of the embodiment.
- FIG. 3 is a circuit diagram of the step-up / step-down circuit of the embodiment.
- FIG. 4 is an operation explanatory diagram of the step-up / step-down circuit of FIG. BEST MODE FOR CARRYING OUT THE INVENTION
- the power supply circuit for driving the liquid crystal display panel shown in FIG. 1 is incorporated in a one-chip semiconductor 50, and the constant voltage circuit 1 outputs IV. It has a mode and a mode that outputs 2 V.
- the step-up / step-down circuit 2 has an external capacitor 6 for charging / discharging the electric charge to step-up / step-down the output 7 of the constant voltage circuit 1.
- the step-up / step-down circuit 2 steps down the output 7 of the constant voltage circuit 1 and outputs 1 V to the output terminal 8 to boost the output 7 of the constant voltage circuit 1.
- 3 V and 4 V are output to output terminals 10 and 11 respectively. At this time, 2 V of the same potential as the constant voltage circuit output 7 is output to the output terminal
- V indicates an absolute value.For example, when the positive electrode is set to the ground potential, it indicates a negative value.
- the buck-boost circuit 2 boosts the output 7 of the constant voltage circuit 1 and outputs 2 V and 3 V to the output terminals 9, 10, and 11, respectively. , 4 V are output, and 1 V having the same potential as the output 7 of the constant voltage circuit 1 is output to the output terminal 8.
- the power supply voltage determination circuit 3 determines whether the power supply voltage is higher or lower than 2 V.
- the power supply voltage determination circuit 3 divides the power supply voltage by resistors R 1 and R 2 as shown in the figure, and compares the divided potential with the reference voltage of the reference voltage generation circuit 31 by a comparison circuit 32. Compares and outputs the comparison result.
- the heavy load detection circuit 4 detects an operation when a heavy load circuit such as an external buzzer operates.
- the heavy load circuit is explained here.
- the CPU section 15 writes "1" to the D terminal of the buzzer control register 16 when the buzzer sounds at a predetermined load.
- This buzzer control register In the evening, the output opens AND gate 17, and the AND gate 17 outputs the buzzer clock signal 18.
- the buzzer clock signal 18 is normally at a frequency of 2 kHz to 8 kHz, and causes the piezoelectric buzzer 21 to ring through the buzzer driver 19 and the transistor 20. .
- the boost I le 22 connected in parallel to the piezoelectric buzzer 21 is the power supply voltage (V DD - V e S voltage) is the sound pressure of a piezoelectric flop The one 21 for cormorants or to One Do small Ku lower Then, the voltage applied to the piezoelectric buzzer 21 is increased by using the back electromotive force of the inductance to increase the sound pressure of the piezoelectric buzzer 21.
- V DD - V e S voltage the power supply voltage
- V DD - V e S voltage the sound pressure of a piezoelectric flop The one 21 for cormorants or to One Do small Ku lower
- the voltage applied to the piezoelectric buzzer 21 is increased by using the back electromotive force of the inductance to increase the sound pressure of the piezoelectric buzzer 21.
- a current of about mA flows when the internal impedance of the battery is high, such as when the battery is exhausted.
- the output voltage of the battery will drop due to the voltage drop caused by the im
- the liquid crystal power supply control means 5 is composed of an OR circuit, and obtains the OR of the output of the power supply voltage determination circuit 3 and the output of the heavy load detection circuit 4 and sends the mode control signal to the constant voltage circuit 1 and the step-up / step-down circuit. Output to circuit 2.
- the liquid crystal power supply control means 5 Output to 2 V
- the operation of the step-up / step-down circuit 2 is also set to the [IV step-down / 3 V, 4 V step-up] mode, and if it is determined that the power supply voltage is Is switched to 1 V, and the operation of the buck-boost circuit 2 is switched to the [2 V, 3 V, 4 V step-up] mode.
- the liquid crystal power supply control means 5 responds to the mode control signal output from the heavy load detection circuit 4 to operate the constant voltage circuit 1 during normal operation, that is, when not under heavy load. If the output is set to 2 V and the operation of the step-up / step-down circuit 2 is also set to the [IV step-down / 3 V, 4 V step-up] mode, and the output of the constant voltage circuit 1 is switched to IV during heavy load operation, At the same time, the operation of the step-up / step-down circuit 2 is switched to the [2 V, 3 V, 4 V step-up] mode.
- the liquid crystal drive circuit 12 inputs the liquid crystal drive voltages 1 V, 2 V, 3 V, and 4 V from the step-up / step-down circuit 2, and also inputs the image information 25 from the CPU unit 15, and based on the image information 25.
- the liquid crystal display signal 13 is output to the liquid crystal display panel 14 by appropriately selecting the liquid crystal drive voltage, and the liquid crystal display panel 14 displays an image based on the liquid crystal display signal 13.
- FIG. 2 is a circuit diagram showing an example of the constant voltage circuit 1.
- PM0S-FET101 is a depletion-type FET
- PM0S-FET102 is an enhancement-type FET.
- the reference voltage at the gun point 103 is output as a constant voltage with respect to V DD .
- the five MOS—FETs 104, 105, 106, 107, and 108 are op-amp differential amplifier circuits, and constitute a differential buffer circuit.
- the mode control signal HVLD 113 is a signal that controls the output mode of the constant voltage circuit 1.
- HVLD is LOW
- the reference voltage is amplified by the feedback resistors 109 and 110 and the reference voltage is amplified.
- Voltage is output as VL2 from terminal 112, and when HVLD is HIGH, a voltage of the same potential as the reference voltage is output as VL1 from terminal 111.
- FIG. 3 is a circuit diagram showing an example of the step-up / step-down circuit 2.
- the clock signal f IGH, click lock signal f B is LOW of Timing of A and f A is L 0 W, in the f n is HIGH of Timing of B, ⁇ -door run-scan-off of the electricity load
- the buck-boost operation is realized by changing the connection between the capacitors (212, 213, and 214 in Fig. 3) and the power supply terminals from V DD to VL4.
- HVLD is L 0 W
- V L 2 is stepped down by 1 Z 2 to V L 1,
- V L 2 is boosted by 1.5 times to increase V L 3
- V L 2 is boosted twice to increase V L 4
- V L 1 is boosted twice to increase V L 2
- V L 1 is boosted three times to V L 3
- V L 1 is boosted four times to V L 4
- connection state of the transfer capacitor in each mode is as shown in Fig. 4.
- the liquid crystal power supply control means 5 may control the liquid crystal power supply by directly receiving the output of the power supply voltage judgment circuit 3 or the output of the heavy load control circuit 4, or a micro computer. In this case, it may be controlled by software.
- a D-type flip-flop circuit is used as the heavy load detection circuit 4, but other types of flip-flop circuits are used. It may be a flip-flop circuit, or a flip-flop constituting the buzzer control register 16 of one buzzer circuit. Industrial applicability where the flip-flop circuit can be used as it is
- the power supply circuit according to the present invention is not limited to a power supply circuit for a liquid crystal display device, but is also applicable if it is necessary to output a multi-valued voltage by a combination of a constant voltage circuit and a step-up / step-down circuit. Applies to.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Radar, Positioning & Navigation (AREA)
- Automation & Control Theory (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Computer Hardware Design (AREA)
- Theoretical Computer Science (AREA)
- Liquid Crystal Display Device Control (AREA)
- Dc-Dc Converters (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
- Direct Current Feeding And Distribution (AREA)
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE69023751T DE69023751T2 (de) | 1989-05-26 | 1990-05-25 | Leistungsquellenschaltung. |
JP2507640A JP2973231B2 (ja) | 1989-05-26 | 1990-05-25 | 電源回路 |
EP90907485A EP0434841B1 (en) | 1989-05-26 | 1990-05-25 | Power source circuit |
HK124497A HK124497A (en) | 1989-05-26 | 1997-06-26 | Power source circuit |
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1/133019 | 1989-05-26 | ||
JP13302089 | 1989-05-26 | ||
JP1/133020 | 1989-05-26 | ||
JP13301989 | 1989-05-26 | ||
JP2/122606 | 1990-05-11 | ||
JP12260690 | 1990-05-11 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1990014625A1 true WO1990014625A1 (en) | 1990-11-29 |
Family
ID=27314478
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1990/000672 WO1990014625A1 (en) | 1989-05-26 | 1990-05-25 | Power source circuit |
Country Status (6)
Country | Link |
---|---|
US (1) | US5323171A (ja) |
EP (1) | EP0434841B1 (ja) |
KR (1) | KR0151839B1 (ja) |
DE (1) | DE69023751T2 (ja) |
HK (1) | HK124497A (ja) |
WO (1) | WO1990014625A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006166581A (ja) * | 2004-12-07 | 2006-06-22 | Seiko Epson Corp | 電源装置 |
Families Citing this family (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5815133A (en) * | 1992-11-17 | 1998-09-29 | Canon Kabushiki Kaisha | Display apparatus |
JP3144166B2 (ja) * | 1992-11-25 | 2001-03-12 | ソニー株式会社 | 低振幅入力レベル変換回路 |
US7068264B2 (en) | 1993-11-19 | 2006-06-27 | Hitachi, Ltd. | Flat display panel having internal power supply circuit for reducing power consumption |
GB2285164B (en) * | 1993-12-22 | 1997-12-10 | Seiko Epson Corp | Liquid-crystal display system and power supply method |
TW277111B (ja) * | 1994-04-20 | 1996-06-01 | Hitachi Seisakusyo Kk | |
US5949397A (en) * | 1994-08-16 | 1999-09-07 | Semiconductor Energy Laboratory Co., Ltd. | Peripheral driver circuit of Liquid crystal electro-optical device |
JPH0895682A (ja) * | 1994-09-29 | 1996-04-12 | Canon Inc | 電子機器 |
KR0147491B1 (ko) * | 1995-05-17 | 1998-12-01 | 김주용 | 엘씨디 전원 순차 제어장치 |
EP0762376A3 (en) * | 1995-08-09 | 1997-11-12 | Sanyo Electric Co. Ltd | Drive circuit for a liquid crystal display device |
KR0154799B1 (ko) * | 1995-09-29 | 1998-12-15 | 김광호 | 킥백전압을 감소시킨 박막 트랜지스터 액정 표시장치의 구동장치 |
JPH1114961A (ja) * | 1997-04-28 | 1999-01-22 | Toshiba Microelectron Corp | 液晶駆動用回路 |
JP3887093B2 (ja) * | 1998-01-29 | 2007-02-28 | 株式会社 沖マイクロデザイン | 表示装置 |
JP3412131B2 (ja) | 1998-06-23 | 2003-06-03 | 株式会社日立製作所 | 液晶表示装置 |
JP3584830B2 (ja) | 1999-03-30 | 2004-11-04 | セイコーエプソン株式会社 | 半導体装置並びにそれを用いた液晶装置及び電子機器 |
TWI277057B (en) * | 2000-10-23 | 2007-03-21 | Semiconductor Energy Lab | Display device |
US6927753B2 (en) | 2000-11-07 | 2005-08-09 | Semiconductor Energy Laboratory Co., Ltd. | Display device |
KR100456987B1 (ko) * | 2001-04-10 | 2004-11-10 | 가부시키가이샤 히타치세이사쿠쇼 | 표시 데이터를 표시하기 위한 표시 장치 및 표시 구동 장치 |
KR100438968B1 (ko) * | 2001-12-31 | 2004-07-03 | 엘지.필립스 엘시디 주식회사 | 액정 패널의 전원공급 장치 |
KR100486281B1 (ko) * | 2002-11-16 | 2005-04-29 | 삼성전자주식회사 | 소비전력을 줄이는 에스티엔(Super TvistNematic) 액정 표시 장치 구동 회로 |
JP4530709B2 (ja) * | 2004-04-21 | 2010-08-25 | Hoya株式会社 | 一定電圧を供給可能な電源回路 |
KR100539264B1 (ko) * | 2004-05-15 | 2005-12-27 | 삼성전자주식회사 | 전원 전압 제거 감지 회로 및 디스플레이 장치 |
JP4686222B2 (ja) * | 2005-03-17 | 2011-05-25 | 株式会社東芝 | 半導体装置 |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
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JPS63277470A (ja) * | 1987-05-06 | 1988-11-15 | Fuji Electric Co Ltd | 発電システム |
Family Cites Families (12)
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US4015420A (en) * | 1976-05-03 | 1977-04-05 | Hughes Aircraft Company | Battery select circuitry and level translator for a digital watch |
JPS5643575A (en) * | 1979-09-18 | 1981-04-22 | Seiko Instr & Electronics Ltd | Electronic clock |
JPS5658746A (en) * | 1979-10-19 | 1981-05-21 | Casio Computer Co Ltd | Power source supply system |
JPS56125683A (en) * | 1980-03-10 | 1981-10-02 | Ricoh Elemex Corp | Power source device for electronic watch |
JPS56153885A (en) * | 1980-04-30 | 1981-11-28 | Nec Corp | Transistor circuit |
JPS576384A (en) * | 1980-06-13 | 1982-01-13 | Hitachi Ltd | Power source circuit and electronic watch using this |
JPS5731333A (en) * | 1980-07-31 | 1982-02-19 | Suwa Seikosha Kk | Power source circuit system |
US4371269A (en) * | 1980-09-09 | 1983-02-01 | Bulova Watch Co., Inc. | D-C Voltage converter for a wristwatch |
JPS57211087A (en) * | 1981-06-22 | 1982-12-24 | Seiko Instr & Electronics Ltd | Boosting circuit of electronic timepiece element |
JPS5938558A (ja) * | 1982-08-25 | 1984-03-02 | Matsushita Electric Works Ltd | 貯湯槽 |
JP2549098B2 (ja) * | 1986-07-08 | 1996-10-30 | 株式会社東芝 | 電子会議システムの伝送制御装置 |
JPS6327747A (ja) * | 1986-07-21 | 1988-02-05 | Takigawa Kogyo Kk | 磁気探傷機オフライン較正装置 |
-
1990
- 1990-05-25 KR KR1019910700072A patent/KR0151839B1/ko not_active IP Right Cessation
- 1990-05-25 EP EP90907485A patent/EP0434841B1/en not_active Expired - Lifetime
- 1990-05-25 WO PCT/JP1990/000672 patent/WO1990014625A1/ja active IP Right Grant
- 1990-05-25 DE DE69023751T patent/DE69023751T2/de not_active Expired - Fee Related
-
1993
- 1993-09-10 US US08/119,884 patent/US5323171A/en not_active Expired - Lifetime
-
1997
- 1997-06-26 HK HK124497A patent/HK124497A/xx not_active IP Right Cessation
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63277470A (ja) * | 1987-05-06 | 1988-11-15 | Fuji Electric Co Ltd | 発電システム |
Non-Patent Citations (1)
Title |
---|
See also references of EP0434841A4 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006166581A (ja) * | 2004-12-07 | 2006-06-22 | Seiko Epson Corp | 電源装置 |
Also Published As
Publication number | Publication date |
---|---|
KR0151839B1 (ko) | 1998-12-15 |
KR920701892A (ko) | 1992-08-12 |
DE69023751D1 (de) | 1996-01-04 |
EP0434841B1 (en) | 1995-11-22 |
EP0434841A4 (en) | 1992-12-09 |
EP0434841A1 (en) | 1991-07-03 |
US5323171A (en) | 1994-06-21 |
DE69023751T2 (de) | 1996-06-20 |
HK124497A (en) | 1997-09-12 |
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