JPH062391U - LED drive circuit - Google Patents

LED drive circuit

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Publication number
JPH062391U
JPH062391U JP041567U JP4156792U JPH062391U JP H062391 U JPH062391 U JP H062391U JP 041567 U JP041567 U JP 041567U JP 4156792 U JP4156792 U JP 4156792U JP H062391 U JPH062391 U JP H062391U
Authority
JP
Japan
Prior art keywords
led
power supply
switching element
voltage
control circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP041567U
Other languages
Japanese (ja)
Other versions
JP2574853Y2 (en
Inventor
知男 白石
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seiwa Electric Mfg Co Ltd
Original Assignee
Seiwa Electric Mfg Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Seiwa Electric Mfg Co Ltd filed Critical Seiwa Electric Mfg Co Ltd
Priority to JP1992041567U priority Critical patent/JP2574853Y2/en
Publication of JPH062391U publication Critical patent/JPH062391U/en
Application granted granted Critical
Publication of JP2574853Y2 publication Critical patent/JP2574853Y2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

(57)【要約】 【目的】 マトリックス型に配列されたLED表示器を
時分割駆動するダイナミック式駆動装置において、装置
全体の消費電力を大幅に低減させること。 【構成】 時分割駆動される第一のスイッチング素子7
をNPN型トランジスタ又はNチャンネルFETで構成
し、表示データに従い駆動される第二のスイッチング素
子8を定電流ICで構成し、LED用電源9と、制御回
路用電源10を個別に設けるとともに、LED用電源9
の電圧を例えば3Vと、制御回路用電源10の電圧より
も低く設定したことを特徴とする。
(57) [Abstract] [Purpose] To drastically reduce the power consumption of the entire device in a dynamic driving device that drives LED displays arranged in a matrix type in a time division manner. [Configuration] First switching element 7 driven in time division
Is composed of an NPN type transistor or an N channel FET, the second switching element 8 driven according to display data is composed of a constant current IC, and an LED power source 9 and a control circuit power source 10 are individually provided and Power supply 9
Is set to be, for example, 3 V, which is lower than the voltage of the control circuit power supply 10, and is characterized in that.

Description

【考案の詳細な説明】[Detailed description of the device]

【0001】[0001]

【産業上の利用分野】[Industrial applications]

本考案は、LEDを使用したドットマトリックス表示器等の駆動回路に関する 。 The present invention relates to a drive circuit such as a dot matrix display using LEDs.

【0002】[0002]

【従来の技術】[Prior art]

ドットマトリックス型LED表示器のダイナミック式駆動装置は、図4に示す ように、数十万個にも及ぶLED(発光ダイオード)がマトリックス型に配列さ れた表示器1、その表示器1の各列のダイオードを同時にスイッチング制御する 走査(スキャンニング)用トランジスタ群2、その表示器1の各行のダイオード を同時にスイッチング制御するデータ用トランジスタ群3、上記トランジスタ群 2および3のグリッド電極に制御信号を与える制御回路4により構成される。 As shown in FIG. 4, a dynamic driving device of a dot matrix type LED display device includes a display device 1 in which hundreds of thousands of LEDs (light emitting diodes) are arranged in a matrix type, and each of the display devices 1. A scanning transistor group 2 for simultaneously switching-controlling diodes in a column, a data transistor group 3 for simultaneously switching-controlling diodes in each row of the display 1, a control signal to the grid electrodes of the transistor groups 2 and 3 The control circuit 4 is provided.

【0003】 従来の駆動回路は、LEDの端子電圧が2Vと低いため、LED点灯用電源回 路と制御回路4のための制御用電源回路を共通化し、1個の直流電源からLED 点灯回路および制御回路へ電源供給していた。すなわち、図4に示す通り、表示 器を構成するLED群1の各列のアノード電極を共通接続したリード線に走査用 トランジスタQS1、QS2、…QSmが接続され、LED群1の各行のカソード電極 を共通接続したリード線に、抵抗器5とデータ用トランジスタQD1、……QDnの 直列回路が接続され、走査用トランジスタ群QS およびデータ用トランジスタ群 QD の各グリード電極は制御回路2に接続されてオンオフ制御され、上記したす べての回路に対し1個の直流電源6から電源供給される。In the conventional drive circuit, since the LED terminal voltage is as low as 2 V, the LED lighting power supply circuit and the control power supply circuit for the control circuit 4 are shared, and the LED lighting circuit and the LED lighting circuit are connected from one DC power supply. Power was being supplied to the control circuit. That is, as shown in FIG. 4, the scanning transistors Q S1 , Q S2 , ... Q Sm are connected to the lead wires that are commonly connected to the anode electrodes of the respective columns of the LED group 1 constituting the display, and the rows of the LED group 1 are connected. A series circuit of a resistor 5 and data transistors Q D1 , ..., Q Dn is connected to a lead wire to which the cathode electrode of is commonly connected, and each greed electrode of the scanning transistor group Q S and the data transistor group Q D is It is connected to the control circuit 2 and is on / off controlled, and power is supplied from one DC power source 6 to all the circuits described above.

【0004】 上記した走査用トランジスタ群QS はPNP型トランジスタで構成され、デー タ用トランジスタ群QD は、NPN形トランジスタで構成され、直流電源6の電 圧は通常は5V程度である。The scanning transistor group Q S is composed of PNP type transistors, the data transistor group Q D is composed of NPN type transistors, and the voltage of the DC power source 6 is usually about 5V.

【0005】[0005]

【考案が解決しようとする課題】 パネル形LED表示装置は、例えば大きさが130cm×80cm、文字、数 字、記号等のユニット配列数40×25=1000ユニット、1ユニットの構成 ドット16×16=256ドットの場合、LEDの数は256,000個、行数 400、列数640となり、ダイナミック駆動方式における駆動用トランジスタ の数は400+640=1040個となる。The panel type LED display device has, for example, a size of 130 cm × 80 cm, the number of unit arrangements of characters, numbers, symbols, etc. 40 × 25 = 1000 units, 1 unit configuration dot 16 × 16 = 256 dots, the number of LEDs is 256,000, the number of rows is 400, and the number of columns is 640, and the number of driving transistors in the dynamic driving method is 400 + 640 = 1040.

【0006】 このような装置において、例えば走査用トランジスタのコレクタ電流は数Aに も達し、そのため、前段に大電流のドライバーを必要とする。更に電流制限用抵 抗7・・・7がデータ用トランジスタの数だけ設けられており、この抵抗による 損失が大きい。In such a device, for example, the collector current of a scanning transistor reaches several amperes, and therefore a large current driver is required in the preceding stage. Further, current limiting resistors 7 ... 7 are provided by the number of data transistors, and the loss due to this resistance is large.

【0007】 従って、電源容量が大きくなるとともに、装置全体の発熱量も大きくなり、強 力な放熱装置が必要になる。 そこで本考案は装置全体の消費電力を大幅に低減させたLED点灯回路の提供 を解決課題とする。Therefore, as the power supply capacity increases, the heat generation amount of the entire device also increases, and a strong heat dissipation device is required. Therefore, the present invention aims to provide an LED lighting circuit in which the power consumption of the entire device is significantly reduced.

【0008】[0008]

【課題を解決するための手段】[Means for Solving the Problems]

この課題を解決するための本考案のLED点灯回路は、マトリックス型に配列 されたLEDを、時分割駆動される第一のスイッチング素子と表示すべき表示デ ータに従い駆動される第二のスイッチング素子と直列に接続し、上記第一および 第二のスイッチング素子が同時に駆動されたときLEDが点灯するダイナミック 式点灯装置において、上記第一および第二のスイッチング素子とLEDの直列回 路へ電流を供給するLED点灯用電源を、上記第一および第二のスイッチング素 子を制御する制御回路の電源と個別に設けるとともに、上記点灯用電源の電圧を 制御回路用電源の電圧よりも低く設定し、上記第一のスイッチング素子をNPN 型トランジスタ又はNチャンネルFETで構成し、上記第二のスイッチング素子 を定電流ICで構成したことを特徴としている。 In order to solve this problem, the LED lighting circuit of the present invention comprises a matrix-type array of LEDs, a first switching element which is time-division driven, and a second switching element which is driven according to display data to be displayed. In a dynamic lighting device that is connected in series with an element and the LED is turned on when the first and second switching elements are simultaneously driven, a current is supplied to the series circuit of the first and second switching elements and the LED. The LED lighting power supply to be supplied is provided separately from the power supply for the control circuit that controls the first and second switching elements, and the voltage of the lighting power supply is set lower than the voltage of the control circuit power supply. The first switching element is an NPN type transistor or an N channel FET, and the second switching element is a constant current IC. Is characterized in that form was.

【0009】[0009]

【作用】 LEDのアノード迄に必要な電圧は、定電流ICの最低動作電圧を0.3V、 LEDの順方向電圧VF は高いものでも2.3V、合計2.6Vとなる。制御回 路の電圧を5.0Vとすれば走査用スイッチング素子がNPNトランジスタの場 合は、2.4VからVBE=0.8Vを差し引いた1.6Vがスイッチの制御電圧 として使用でき、また、スイッチング素子がFETの場合は2.4Vがスイッチ ングの制御電圧として使用できる。As for the voltage required up to the anode of the LED, the minimum operating voltage of the constant current IC is 0.3V and the forward voltage V F of the LED is 2.3V even if it is high, which is 2.6V in total. If the voltage of the control circuit is 5.0V and the scanning switching element is an NPN transistor, 1.6V obtained by subtracting V BE = 0.8V from 2.4V can be used as the control voltage of the switch. If the switching element is a FET, 2.4V can be used as the control voltage for switching.

【0010】 データ制御用となる第二のスイッチング素子として、NPN型トランジスタ又 はNチャンネルFETを出力部に有する定電流ICを用いているので、定電流I Cの出力電圧が小さくてすみ、従来必要とした限流用抵抗を用いていないことも あって、LED駆動回路の電源電圧を下げることが可能となった。As a second switching element for data control, a constant current IC having an NPN type transistor or an N channel FET in the output section is used, so that the output voltage of the constant current I C is small, Since the required current limiting resistor is not used, the power supply voltage of the LED drive circuit can be lowered.

【0011】[0011]

【実施例】【Example】

図1に本考案実施例の回路図を示す。表示器1は(m×n)個のLEDがm行 、n列のマトリック型に配列されたもので、行引出線S1,S2 …Sm にLEDの アノード電極が接続され、列引出線D1,2 …Dn にLEDのカソード電極が接 続されている。FIG. 1 shows a circuit diagram of an embodiment of the present invention. Indicator 1 is (m × n) pieces of LED are m rows, in which arranged in matrix-type and n columns, the anode electrode of the LED is connected to the row lead lines S 1, S 2 ... S m, column extraction The cathode electrode of the LED is connected to the lines D 1, D 2 ... D n .

【0012】 行引出線S1,S2 …Sm は第一のスイッチング素子群7に接続され、列引出線 D1,2 …Dn は抵抗を介することなく直接に第二のスイッチング素子群8に接 続され、これらのLED駆動回路にLED用電源9が接続される。これに対し制 御回路4には別個の制御回路用電源10が接続される。この制御回路用電源10 の電圧は従来通り5V程度であるのに比べ、LED用電源9の電圧は3V程度と 低い。The row leader lines S 1 , S 2 ... S m are connected to the first switching element group 7, and the column leader lines D 1, D 2 ... D n are directly connected to the second switching elements without a resistor. It is connected to the group 8 and the LED power supply 9 is connected to these LED drive circuits. On the other hand, a separate control circuit power source 10 is connected to the control circuit 4. The voltage of the control circuit power supply 10 is about 5V as in the conventional case, whereas the voltage of the LED power supply 9 is about 3V, which is low.

【0013】 第一のスイッチング素子群7は、NPN型トランジスタ、或いはNチャンネル FETにより構成される。第二のスイッチング素子群8は定電流ICにより構成 される。The first switching element group 7 is composed of NPN type transistors or N channel FETs. The second switching element group 8 is composed of a constant current IC.

【0014】 図2に、第一のスイッチング素子としてNPN形トランジスタを用いたときの 1個のLEDに係る駆動回路を示す。1個のLED11のアノード電極AにNP N形トランジスタ12のエミッタが接続され、このトランジスタ12のコレクタ はLED用電源9のプラス端子に接続され、トランジスタ12のベースは制御回 路の一部を構成するドライブ用トランジスタ13の出力端に抵抗14を介して接 続され、このドライブ用トランジスタ13は制御回路用電源10により付勢され る。LED10のカソード電極Kは定電流IC8に接続される。FIG. 2 shows a drive circuit for one LED when an NPN transistor is used as the first switching element. The emitter of the NPN transistor 12 is connected to the anode electrode A of one LED 11, the collector of this transistor 12 is connected to the positive terminal of the LED power supply 9, and the base of the transistor 12 constitutes a part of the control circuit. Is connected to the output terminal of the driving transistor 13 via a resistor 14, and the driving transistor 13 is energized by the control circuit power supply 10. The cathode electrode K of the LED 10 is connected to the constant current IC8.

【0015】 図3に、第一のスイッチング素子としてN形FETを用いたときの1個のLE Dに係る駆動回路を示す。図2のNPN形トランジスタ12に代えて、Nチャン ネルFET15が接続されている。FIG. 3 shows a drive circuit for one LED when an N-type FET is used as the first switching element. An N-channel FET 15 is connected instead of the NPN type transistor 12 of FIG.

【0016】 これらの実施例において、制御回路用電源電圧が5Vのとき、第一のスイッチ ング素子がオンのときの電圧降下分0.5V、第二のスイッチング素子がオンの ときの電圧降下分0.3Vであるから、LED用電源電圧が2.8VあればLE Dに2Vの動作電圧がかかり、LEDを発光させるに十分である。In these embodiments, when the power supply voltage for the control circuit is 5 V, the voltage drop of 0.5 V when the first switching element is on, and the voltage drop of when the second switching element is on Since it is 0.3V, if the LED power supply voltage is 2.8V, an operating voltage of 2V is applied to the LED, which is sufficient to cause the LED to emit light.

【0017】[0017]

【考案の効果】[Effect of device]

従来例として挙げた256,000個のLEDを使用した表示パネルについて 、1ドットにつき赤、緑の2種LEDを用い、1個のLEDに20mAの電流が 供給され、その電源電圧が5V、時分割のデューティが1/16である場合の消費電 力を計算すると 20mA ×2(種) ×16×16×5V×1/16×1000=3.2KW となるのに対し、本考案によれば同じ場合について、 20mA ×2(種) ×16×16×2.8V×1/16×1000=1.79KW ですみ、従来に比べて約56%の電力消費となる。 Regarding the display panel using 256,000 LEDs mentioned as a conventional example, two kinds of LEDs of red and green are used for each dot, and a current of 20 mA is supplied to one LED, and the power supply voltage is 5V, When the power consumption when the division duty is 1/16 is calculated as 20mA × 2 (type) × 16 × 16 × 5V × 1/16 × 1000 = 3.2KW, the same according to the present invention. In the case, 20mA x 2 (type) x 16 x 16 x 2.8V x 1/16 x 1000 = 1.79KW, which is about 56% of the power consumption compared to the conventional case.

【図面の簡単な説明】[Brief description of drawings]

【図1】は、本考案の実施例を示す回路図である。FIG. 1 is a circuit diagram showing an embodiment of the present invention.

【図2】は、図1の第一のスイッチング素子が、NPN
形トランジスタであるときの1個のLEDに係る駆動回
路図である。
FIG. 2 is a diagram showing that the first switching element of FIG.
It is a drive circuit diagram which concerns on one LED when it is a shape transistor.

【図3】は、図1の第一のスイッチング素子が、Nチャ
ネルFETであるときの1個のLEDに係る駆動回路図
である。
FIG. 3 is a drive circuit diagram of one LED when the first switching element of FIG. 1 is an N-channel FET.

【図4】は、従来例を示す回路図である。FIG. 4 is a circuit diagram showing a conventional example.

【符号の説明】[Explanation of symbols]

1・・・表示器 7・・・第一のスイッチング素子 8・・・第二のスイッチング素子 9・・・LED用電源 10・・制御回路用電源 11・・LED 12・・NPN形トランジスタ 15・・NチャンネルFET 1 ... Indicator 7 ... First switching element 8 ... Second switching element 9 ... LED power supply 10 ... Control circuit power supply 11 ... LED 12 ... NPN transistor 15 ...・ N-channel FET

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 【請求項1】 マトリックス型に配列されたLEDを、
時分割駆動される第一のスイッチング素子と表示すべき
表示データに従い駆動される第二のスイッチング素子と
直列に接続し、上記第一および第二のスイッチング素子
が同時に駆動されたときLEDが点灯するダイナミック
式駆動装置において、上記第一および第二のスイッチン
グ素子とLEDの直列回路へ電流を供給するLED用電
源を、上記第一および第二のスイッチング素子を制御す
る制御回路の電源と個別に設けるとともに、上記LED
用電源の電圧を制御回路用電源の電圧よりも低く設定
し、上記第一のスイッチング素子をNPN型トランジス
タ又はNチャンネルFETで構成し、上記第二のスイッ
チング素子を定電流ICで構成したことを特徴とするL
ED駆動回路。
1. LEDs arranged in a matrix form,
The first switching element driven in time division and the second switching element driven in accordance with the display data to be displayed are connected in series, and the LED is turned on when the first and second switching elements are simultaneously driven. In the dynamic driving device, an LED power supply for supplying a current to the series circuit of the first and second switching elements and the LED is separately provided from a power supply of a control circuit for controlling the first and second switching elements. Together with the above LED
The voltage of the power supply for power supply is set lower than the voltage of the power supply for control circuit, the first switching element is configured by an NPN transistor or an N channel FET, and the second switching element is configured by a constant current IC. Characteristic L
ED drive circuit.
JP1992041567U 1992-06-17 1992-06-17 LED drive circuit Expired - Fee Related JP2574853Y2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1992041567U JP2574853Y2 (en) 1992-06-17 1992-06-17 LED drive circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1992041567U JP2574853Y2 (en) 1992-06-17 1992-06-17 LED drive circuit

Publications (2)

Publication Number Publication Date
JPH062391U true JPH062391U (en) 1994-01-14
JP2574853Y2 JP2574853Y2 (en) 1998-06-18

Family

ID=12612027

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1992041567U Expired - Fee Related JP2574853Y2 (en) 1992-06-17 1992-06-17 LED drive circuit

Country Status (1)

Country Link
JP (1) JP2574853Y2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8896516B2 (en) 2007-07-06 2014-11-25 Nlt Technologies, Ltd. Light emission control circuit, light emission control method, flat illuminating device, and liquid crystal display device having the same device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8896516B2 (en) 2007-07-06 2014-11-25 Nlt Technologies, Ltd. Light emission control circuit, light emission control method, flat illuminating device, and liquid crystal display device having the same device

Also Published As

Publication number Publication date
JP2574853Y2 (en) 1998-06-18

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