JP2001215913A - Lighting circuit - Google Patents

Lighting circuit

Info

Publication number
JP2001215913A
JP2001215913A JP2000027099A JP2000027099A JP2001215913A JP 2001215913 A JP2001215913 A JP 2001215913A JP 2000027099 A JP2000027099 A JP 2000027099A JP 2000027099 A JP2000027099 A JP 2000027099A JP 2001215913 A JP2001215913 A JP 2001215913A
Authority
JP
Japan
Prior art keywords
circuit
light emitting
transistor
current
voltage
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.)
Pending
Application number
JP2000027099A
Other languages
Japanese (ja)
Inventor
Jun Takahashi
純 高橋
Tomoyuki Koga
智之 古賀
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.)
Toko Inc
Original Assignee
Toko Inc
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 Toko Inc filed Critical Toko Inc
Priority to JP2000027099A priority Critical patent/JP2001215913A/en
Publication of JP2001215913A publication Critical patent/JP2001215913A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/345—Current stabilisation; Maintaining constant current
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/37—Converter circuits
    • H05B45/3725—Switched mode power supply [SMPS]
    • H05B45/375—Switched mode power supply [SMPS] using buck topology
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/37—Converter circuits
    • H05B45/3725—Switched mode power supply [SMPS]
    • H05B45/38—Switched mode power supply [SMPS] using boost topology
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/395—Linear regulators
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/395—Linear regulators
    • H05B45/397—Current mirror circuits

Abstract

PROBLEM TO BE SOLVED: To provide a lighting circuit capable of making a constant current flow through light emitting diodes and the value of the current correctly and easily. SOLUTION: A constant current circuit 2 is connected in series with a light emitting unit 3 consisting of light emitting diodes LED11 to LED1n. The DC power is supplied from a converter circuit 1 to the series circuit of the light emitting unit 3 and the constant current circuit 2 while controlling its output voltage so that the voltage across terminals of the circuit 2 becomes constant. In constitution like this, a current i passing through the unit 3 and the circuit 2 is held at a constant value by the current stabilizing action of the inside of the circuit 2. As a result, the current passing through the unit 3 is hardly affected by ripples of the output voltage of the circuit 1 and ambient temperatures as compared with a case that a resistance R1 is used.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、発光ダイオードを
定電流で駆動し、発光ユニットを安定して点灯させるた
めの点灯回路の改良技術に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved lighting circuit for driving a light emitting diode with a constant current to stably light a light emitting unit.

【０００２】[0002]

【従来の技術】発光ダイオードを点灯させた時、その発
光輝度は電流の大きさに依存する。このため、発光ダイ
オードに安定して点灯させるには、発光ダイオードを定
電流にて駆動することが望ましい。図７には、発光ダイ
オードを定電流駆動するよう構成された点灯回路の、従
来の一例の回路図を示した。図７に示す回路は以下のよ
うな構成としている。チョークコイルＬ１の一端を電源
供給点（ＶＩＮ）に接続し、チョークコイルＬ１の他端
をＮＰＮ型のスイッチングトランジスタＱ１のコレクタ
に接続する。スイッチングトランジスタＱ１のコレクタ
にダイオードＤ１のアノードを接続し、ダイオードＤ１
のカソードをコンデンサＣ１を介してグランドに接続す
る。2. Description of the Related Art When a light emitting diode is turned on, its light emission luminance depends on the magnitude of current. Therefore, it is desirable to drive the light emitting diode with a constant current in order to stably light the light emitting diode. FIG. 7 is a circuit diagram of a conventional example of a lighting circuit configured to drive a light emitting diode at a constant current. The circuit shown in FIG. 7 has the following configuration. One end of the choke coil L1 is connected to a power supply point (V IN ), and the other end of the choke coil L1 is connected to the collector of an NPN-type switching transistor Q1. The anode of the diode D1 is connected to the collector of the switching transistor Q1.
Is connected to ground via a capacitor C1.

【０００３】スイッチングトランジスタＱ１のエミッタ
はグランドに接続し、ベースは制御回路ＤＲ１に接続す
る。制御回路ＤＲ１はさらに誤差増幅器ＥＡ１の出力側
と接続し、誤差増幅器ＥＡ１の２つある入力側のうちの
第１の入力側は基準電圧源Ｖ ｒｅｆを介してグランドに
接続する。このチョークコイルＬ１、スイッチングトラ
ンジスタＱ１、ダイオードＤ１、コンデンサＣ１、制御
回路ＤＲ１、誤差増幅器ＥＡ１および基準電圧源Ｖ
ｒｅｆによりコンバータ回路１ａが構成されている。複
数の発光ダイオードＬＥＤ１１〜ＬＥＤ１ｎを全て直列
に接続し、発光ユニット３を構成する。この発光ユニッ
ト３に抵抗Ｒ１を直列に接続し、この直列接続された発
光ユニット３と抵抗Ｒ１をコンバータ回路１ａのコンデ
ンサＣ１に対して並列に接続する。そして、発光ユニッ
ト３と抵抗Ｒ１の接続点を誤差増幅器ＥＡ１の２つある
入力側のうちの第２の入力側に接続する。The emitter of the switching transistor Q1
Is connected to the ground, and the base is connected to the control circuit DR1.
You. The control circuit DR1 is further connected to the output side of the error amplifier EA1.
Connected to the two input sides of the error amplifier EA1.
The first input is a reference voltage source V refThrough to the ground
Connecting. The choke coil L1 and the switching transformer
Transistor Q1, diode D1, capacitor C1, control
Circuit DR1, error amplifier EA1, and reference voltage source V
refForm a converter circuit 1a. Duplicate
Number of light emitting diodes LED11~ LED1nAll in series
To form the light-emitting unit 3. This light emitting unit
The resistor R1 is connected in series to the
The optical unit 3 and the resistor R1 are connected to the converter of the converter circuit 1a.
It is connected in parallel to the sensor C1. And the light emitting unit
There are two connection points of the error amplifier EA1
Connect to the second input side of the input side.

【０００４】以上のような構成の回路では、先ず、スイ
ッチングトランジスタＱ１が制御回路ＤＲ１からの駆動
信号に応じてオン、オフ動作を繰り返し、電流を断続す
る。スイッチングトランジスタＱ１がオン状態からオフ
状態に転換した時、チョークコイルＬ１に逆起電圧が発
生し、入力電圧ＶＩＮと逆起電圧による電圧値の高い合
成電圧がダイオードＤ１のアノードの位置に現れる。す
るとダイオードＤ１を介してコンデンサＣ１に充電電流
が流入し、コンデンサＣ１の端子間に入力電圧ＶＩＮよ
り高い電圧が出現する。このコンデンサＣ１の端子間電
圧がコンバータ回路１ａの出力電圧として直列接続され
た発光ユニット３と抵抗Ｒ１に供給される。これにより
発光ユニット３の各発光ダイオードＬＥＤ１１〜ＬＥＤ
１ｎに電流が流れ、各発光ダイオードＬＥＤ１１〜ＬＥ
Ｄ１ｎが点灯する。In the circuit configured as described above, first, the switching transistor Q1 repeats on / off operations in response to a drive signal from the control circuit DR1, and interrupts current. When the switching transistor Q1 changes from the on state to the off state, a back electromotive voltage is generated in the choke coil L1, and a composite voltage having a high voltage value due to the input voltage VIN and the back electromotive voltage appears at the anode position of the diode D1. Then, a charging current flows into the capacitor C1 via the diode D1, and a voltage higher than the input voltage VIN appears between the terminals of the capacitor C1. The voltage between the terminals of the capacitor C1 is supplied as the output voltage of the converter circuit 1a to the light emitting unit 3 and the resistor R1 connected in series. Thereby, each of the light emitting diodes LED 11 to LED 11 of the light emitting unit 3
1n, and the light emitting diodes LED 11 to LE 11
D 1n lights up.

【０００５】ここで図７の回路では、誤差増幅器ＥＡ１
の第１の入力側は基準電圧源Ｖｒｅ ｆを介してグランド
に接続されている。一方、誤差増幅器ＥＡ１の第２の入
力側は抵抗Ｒ１を介してグランドに接続された形となっ
ている。このため図７の回路のコンバータ回路１ａは、
抵抗Ｒ１の端子間電圧と基準電圧Ｖｒｅｆがほぼ等しく
なるよう、スイッチングトランジスタＱ１のオン、オフ
期間を変化させ、その出力電圧であるコンデンサＣ１の
端子間電圧を制御する。例えば、図７の回路が定常運転
状態に有り、抵抗Ｒ１の端子間電圧がほぼ基準電圧Ｖ
ｒｅｆに等しい電圧値に保持されているものとする。こ
の時、抵抗Ｒ１を流れる電流ＩＲは、ほぼ（Ｖｒｅｆ／
Ｒ１）で一定となる。発光ユニット３は抵抗Ｒ１に直列
接続されているため、発光ユニット３を流れる電流は抵
抗Ｒ１を流れる電流ＩＲと等しくなる。これにより、発
光ユニット３を構成する各発光ダイオードＬＥＤ１１〜
ＬＥＤ１ｎは定電流にて駆動されることになる。Here, in the circuit of FIG. 7, the error amplifier EA1
First input of which is connected to ground via a reference voltage source V re f. On the other hand, the second input side of the error amplifier EA1 is connected to the ground via the resistor R1. For this reason, the converter circuit 1a of the circuit of FIG.
The on / off period of the switching transistor Q1 is changed so that the voltage between the terminals of the resistor R1 and the reference voltage Vref become substantially equal, and the voltage between the terminals of the capacitor C1, which is the output voltage, is controlled. For example, the circuit of FIG. 7 is in a steady operation state, and the voltage between the terminals of the resistor R1 is substantially equal to the reference voltage V.
It is assumed that the voltage is maintained at a voltage value equal to ref . At this time, the current I R flowing through the resistor R1 is approximately (V ref /
R1) becomes constant. Since the light-emitting unit 3 are connected in series to the resistor R1, the current flowing through the light emitting unit 3 is equal to the current I R flowing through the resistor R1. Thereby, each of the light emitting diodes LED 11 to LED 11 to configure the light emitting unit 3 is formed.
The LED 1n is driven by a constant current.

【０００６】周知のように、発光ダイオードに電流を流
すと、その端子間には順方向電圧が現れる。複数個の発
光ダイオードを直列に接続すると、当然、発光ダイオー
ドを点灯するために発光ユニット３の両端に印加するべ
き電圧も高くなってしまう。しかし、実際に使用される
素子の耐圧性能や回路の絶縁などの観点からすると、コ
ンバータ回路１ａの出力電圧をあまり高い値にすること
は望ましくない。このため、数多くの発光ダイオードを
同時に点灯しなければならない場合には、図８に示すよ
うにｎ個の発光ダイオードを直列接続した発光ダイオー
ド列をｍ列配置し、発光ユニット３ａを形成する。これ
ならば、ｎ×ｍ個の発光ダイオードを点灯する際にも、
発光ユニット３ａに印加すべき電圧は発光ダイオードｎ
個の順方向電圧の合計値以上で済み、コンバータ回路１
ａの出力電圧の低電圧化を図ることができる。As is well known, when a current flows through a light emitting diode, a forward voltage appears between its terminals. When a plurality of light emitting diodes are connected in series, the voltage to be applied to both ends of the light emitting unit 3 for lighting the light emitting diodes naturally increases. However, it is not desirable to set the output voltage of the converter circuit 1a to a very high value from the viewpoint of the withstand voltage performance of the element actually used and the insulation of the circuit. Therefore, when many light emitting diodes must be turned on at the same time, as shown in FIG. 8, m light emitting diode rows in which n light emitting diodes are connected in series are arranged to form the light emitting unit 3a. In this case, when lighting n × m light emitting diodes,
The voltage to be applied to the light emitting unit 3a is a light emitting diode n
The converter circuit 1 needs to be equal to or more than the total value of
The output voltage of a can be reduced.

【０００７】なお、ｎ個の発光ダイオードを直列接続し
た発光ダイオード列をｍ列配置し、発光ユニット３ａを
形成した場合、第１列目から第ｍ列目の各発光ダイオー
ド列には、それぞれ抵抗Ｒ１〜Ｒｍが直列に接続され
る。そして、特定の発光ダイオード列と抵抗の接続点、
具体的には第１列目の発光ダイオード列ＬＥＤ１１〜Ｌ
ＥＤ１ｎと抵抗Ｒ１との接続点がコンバータ回路１ａの
誤差増幅器ＥＡ１の第２の入力側に接続されることにな
る。When m light emitting diode rows in which n light emitting diodes are connected in series are arranged to form a light emitting unit 3a, each of the first to m th light emitting diode rows has a resistance. R1 to Rm are connected in series. And a connection point between a specific light emitting diode row and a resistor,
Specifically, the light emitting diode rows LED 11 to L of the first row
The connection point between the ED 1n and the resistor R1 is connected to the second input side of the error amplifier EA1 of the converter circuit 1a.

【０００８】[0008]

【発明が解決しようとする課題】図７の点灯回路は、コ
ンバータ回路１ａと、発光ユニット３に直列接続した抵
抗Ｒ１とにより、簡易な構成で発光ダイオードの定電流
駆動を実現している。ところで、図７では、コンバータ
回路１ａがスイッチングレギュレータの形態となってい
る。スイッチングレギュレータは、シリーズレギュレー
タに比べて回路の効率は高いものの、そのフィードバッ
ク制御作用とスイッチング動作の関係に起因して、出力
電圧にリップルを生じることが避けられない。このため
図７の回路では抵抗Ｒ１の両端に現れる電圧にリップル
が生じ、電圧のリップルに伴って発光ユニット３を流れ
る電流にもリップルが生じるといった問題があった。The lighting circuit of FIG. 7 realizes constant current driving of a light emitting diode with a simple configuration by a converter circuit 1a and a resistor R1 connected in series to the light emitting unit 3. By the way, in FIG. 7, the converter circuit 1a is in the form of a switching regulator. Although the switching regulator has higher circuit efficiency than the series regulator, it is unavoidable that the output voltage ripples due to the relationship between the feedback control action and the switching operation. For this reason, the circuit of FIG. 7 has a problem that a voltage appears at both ends of the resistor R1 and a ripple occurs in the current flowing through the light emitting unit 3 with the ripple of the voltage.

【０００９】また、発光ダイオード素子の製品毎の順方
向電圧のばらつきは、各種電子素子の特性値のばらつき
の中でも最も大きい部類に属する。このため、図８に示
すような構成として数多くの発光ダイオードを点灯させ
ようとした場合、各発光ダイオードＬＥＤ１１〜ＬＥＤ
ｍｎの順方向電圧値のばらつきによって、第１から第ｍ
の各発光ダイオード列の列毎の順方向電圧の合計値にも
大きなばらつきが生じる。こうなると、製品毎に第１列
から第ｍ列の各発光ダイオード列を流れる電流の値を厳
密に設定することは不可能となり、例えば、抵抗Ｒ１〜
Ｒｍの各抵抗値を同一に設定し、かつ、各列毎の発光ダ
イオードの直列数を同じにしても、第１列から第ｍ列の
各発光ダイオード列を流れる電流の値を全て同一にする
ことは困難であった。Also, the variation in the forward voltage of each product of the light emitting diode element belongs to the largest category among the variation in the characteristic value of various electronic elements. For this reason, in the case where a large number of light emitting diodes are to be turned on as shown in FIG. 8, each of the light emitting diodes LED 11 to LED 11
mn , the first to m-th
A large variation also occurs in the total value of the forward voltage of each light emitting diode column. In this case, it is impossible to strictly set the value of the current flowing through each of the first to m-th light emitting diode rows for each product.
Even when the resistance values of Rm are set to be the same and the number of light emitting diodes in each column is the same, the values of the currents flowing through the first to m-th light emitting diode columns are all the same. It was difficult.

【００１０】これに加え、周囲温度の変化などによって
発光ダイオードＬＥＤ１１〜ＬＥＤ ｍｎの順方向電圧の
値が変化すると、フィードバック制御がなされていない
第１列目以外の各発光ダイオード列を通過する電流の値
が本来の設定値から変化してしまう、などの問題もあっ
た。そこで本発明は、発光ダイオードに安定した電流を
流すことができ、しかもその電流値を正確かつ容易に設
定することが可能な点灯回路を提供することを目的とし
た。[0010] In addition to this, due to changes in the ambient temperature, etc.
Light emitting diode LED11~ LED mnOf the forward voltage
When the value changes, feedback control is not performed
The value of the current passing through each light-emitting diode row other than the first row
May change from the original setting value.
Was. Therefore, the present invention provides a stable current to the light emitting diode.
Flow, and the current value can be set accurately and easily.
The purpose is to provide a lighting circuit that can be set
Was.

【００１１】[0011]

【課題を解決するための手段】上記課題を解決するため
の本発明による点灯回路は、少なくとも１つの発光ダイ
オードからなる発光ユニットに対し、当該発光ダイオー
ドが点灯するのに必要な直流電力を供給する点灯回路に
おいて、発光ユニットに対して直列に接続される定電流
回路と、定電流回路の端子間電圧が一定になるよう出力
電圧を制御しながら、発光ユニットと定電流回路の直列
回路に直流電力を供給するコンバータ回路とを具備する
ことを特徴とする。A lighting circuit according to the present invention for solving the above problems supplies a light emitting unit comprising at least one light emitting diode with a DC power necessary for the light emitting diode to light up. In the lighting circuit, the DC power is applied to the series circuit of the light emitting unit and the constant current circuit while controlling the output voltage so that the voltage between the terminals of the constant current circuit connected in series to the light emitting unit and the constant current circuit becomes constant. And a converter circuit for supplying

【００１２】ここで具体的には、電流源と、電流源にそ
の主電流路が直列に接続された第１のトランジスタと、
発光ユニットにその主電流路が直列に接続され、第１の
トランジスタの制御端子にその制御端子が接続された第
２のトランジスタとによって定電流回路を構成する。あ
るいは、発光ユニットに直列接続された第３のトランジ
スタと、発光ユニットを流れる電流に応じて第３のトラ
ンジスタの導通状態を制御する誤差増幅器とによって定
電流回路を構成する。コンバータ回路については、定電
流回路の端子間電圧を、定電流回路が所定の値の電流を
安定して流すことのできるサチレーション電圧以上の電
圧値に保持するよう構成するものとする。Here, specifically, a current source, a first transistor having a main current path connected in series to the current source,
The light emitting unit has its main current path connected in series, and the control terminal of the first transistor and the second transistor whose control terminal is connected form a constant current circuit. Alternatively, a constant current circuit is configured by a third transistor connected in series to the light emitting unit and an error amplifier that controls a conduction state of the third transistor according to a current flowing through the light emitting unit. The converter circuit is configured to hold the voltage between terminals of the constant current circuit at a voltage value equal to or higher than a saturation voltage at which the constant current circuit can stably flow a predetermined current.

【００１３】[0013]

【発明の実施の形態】少なくとも１つの発光ダイオード
からなる発光ユニットに定電流回路を直列接続する。そ
して、当該発光ユニットと定電流回路の直列回路に対し
て、コンバータ回路から、定電流回路の端子間電圧が一
定になるよう出力電圧を制御しながら直流電力を供給す
る。ここで、駆動電圧供給点とグランドとの間に電流源
と第１のトランジスタの主電流路を直列接続し、第１の
トランジスタの主電流路の一端と制御端子とを接続す
る。第１のトランジスタの制御端子に第２のトランジス
タの制御端子を接続し、第２のトランジスタの主電流路
を発光ユニットと直列状態でコンバータ回路とグランド
との間に接続する。この電流源と第１および第２のトラ
ンジスタによって定電流回路を構成するものとする。コ
ンバータ回路についてはスイッチングレギュレータを使
用し、コンバータ回路の出力検出端子を発光ユニットと
定電流回路の接続点に接続する。DESCRIPTION OF THE PREFERRED EMBODIMENTS A constant current circuit is connected in series to a light emitting unit comprising at least one light emitting diode. Then, DC power is supplied from the converter circuit to the series circuit of the light emitting unit and the constant current circuit while controlling the output voltage so that the terminal voltage of the constant current circuit becomes constant. Here, the current source and the main current path of the first transistor are connected in series between the drive voltage supply point and the ground, and one end of the main current path of the first transistor is connected to the control terminal. The control terminal of the second transistor is connected to the control terminal of the first transistor, and the main current path of the second transistor is connected between the converter circuit and ground in series with the light emitting unit. It is assumed that a constant current circuit is constituted by this current source and the first and second transistors. A switching regulator is used for the converter circuit, and an output detection terminal of the converter circuit is connected to a connection point between the light emitting unit and the constant current circuit.

【００１４】別の実施の形態では、第３のトランジスタ
の主電流路と抵抗と発光ユニットを直列状態でコンバー
タ回路とグランドとの間に接続する。第３のトランジス
タの制御端子に誤差増幅器の出力側を接続し、誤差増幅
器の２つある入力側のうちの第１の入力側を前記抵抗の
第３のトランジスタ側の一端に接続する。誤差増幅器の
第２の入力側は前記抵抗の第３のトランジスタとは逆側
の他端に、基準電圧源を介して接続する。この第３のト
ランジスタ、誤差増幅器、抵抗および基準電圧源によっ
て定電流回路を構成するものとする。コンバータ回路に
ついてはスイッチングレギュレータを使用し、コンバー
タ回路の出力検出端子を発光ユニットと定電流回路の接
続点に接続する。In another embodiment, the main current path, the resistor and the light emitting unit of the third transistor are connected in series between the converter circuit and the ground. An output side of the error amplifier is connected to a control terminal of the third transistor, and a first input side of the two input sides of the error amplifier is connected to one end of the resistor on the third transistor side. The second input of the error amplifier is connected to the other end of the resistor opposite to the third transistor via a reference voltage source. It is assumed that a constant current circuit is formed by the third transistor, the error amplifier, the resistor, and the reference voltage source. A switching regulator is used for the converter circuit, and an output detection terminal of the converter circuit is connected to a connection point between the light emitting unit and the constant current circuit.

【００１５】さらに別の実施の形態では、ｎ×ｍ個の発
光ダイオードを各々ｎ個ずつ直列接続し、これによって
得られたｍ個の発光ダイオード列を並列に配置し、発光
ユニットを構成する。ここで、駆動電圧供給点とグラン
ドとの間に電流源と第１のトランジスタの主電流路を直
列接続し、第１のトランジスタの主電流路の一端と制御
端子とを接続する。第１のトランジスタの制御端子に対
し、発光ダイオード列と同数のｍ個の第２のトランジス
タのそれぞれの制御端子を接続する。この電流源と第１
のトランジスタ、ｍ個の第２のトランジスタによって定
電流回路を構成する。発光ユニットと定電流回路の、そ
れぞれ対応する発光ダイオード列と第２のトランジスタ
を各１づつ直列に接続し、こうして得られたｍ個の発光
ダイオード列と第２のトランジスタの直列回路をコンバ
ータ回路とグランドとの間に並列に接続する。コンバー
タ回路にはスイッチングレギュレータを使用し、コンバ
ータ回路の出力検出端子を所定の発光ダイオード列と第
２のトランジスタの接続点に接続する。In still another embodiment, n × m light emitting diodes are connected in series, n light emitting diodes each, and the m light emitting diode rows thus obtained are arranged in parallel to form a light emitting unit. Here, the current source and the main current path of the first transistor are connected in series between the drive voltage supply point and the ground, and one end of the main current path of the first transistor is connected to the control terminal. The control terminals of the m second transistors are connected to the control terminals of the first transistors in the same number as the number of light emitting diode arrays. This current source and the first
, And m second transistors constitute a constant current circuit. The light emitting unit and the constant current circuit of the corresponding light emitting diode row and the second transistor are connected one by one in series, and the m light emitting diode rows and the second transistor thus obtained are connected in series with the converter circuit. Connect in parallel with the ground. A switching regulator is used as the converter circuit, and an output detection terminal of the converter circuit is connected to a connection point between a predetermined light emitting diode row and the second transistor.

【００１６】[0016]

【実施例】本発明の点灯回路の基本概念は、電圧変化や
周囲温度変化が生じても流通電流の設定値が変化しない
安定度の高い電流の流通手段と、発光ダイオードと電流
の流通手段が動作する上で必要な電圧を確保すると同時
に、その電圧の安定化によって副次的に電流の安定化に
寄与する直流電力の供給手段とを組み合わせることにあ
る。図１はこの基本概念に基づく点灯回路を示してい
る。図１に示す点灯回路は、複数の発光ダイオードＬＥ
Ｄ１１〜ＬＥＤ１ｎからなる発光ユニット３に対して定
電流回路２を接続し、この発光ユニット３と定電流回路
２の直列回路に対してコンバータ回路１の出力端子ＯＵ
Ｔを接続する。発光ユニット３と定電流回路２の接続点
をコンバータ回路１の出力検出端子ＦＢに接続し、コン
バータ回路１の電源端子ＶＣＣとグランド端子ＧＮＤを
それぞれ電源供給点（ＶＩＮ）とグランドに接続した構
成となっている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic concept of the lighting circuit according to the present invention is that a current flowing means having a high stability in which a set value of a flowing current does not change even when a voltage change or an ambient temperature change occurs, and a light emitting diode and a current flowing means. The object of the present invention is to combine a DC power supply means which secures a voltage required for operation and which contributes to the stabilization of current by the stabilization of the voltage. FIG. 1 shows a lighting circuit based on this basic concept. The lighting circuit shown in FIG. 1 includes a plurality of light emitting diodes LE.
D 11 connects the constant current circuit 2 to the light-emitting unit 3 comprising a ~LED 1n, the output terminal OU of the converter circuit 1 to the series circuit of the light emitting unit 3 and the constant current circuit 2
Connect T. Connect the connection point of the light emitting unit 3 and the constant current circuit 2 to output detection terminal FB of the converter circuit 1, and connect the power terminal V CC and the ground terminal GND of the converter circuit 1, respectively power supply point and (V IN) to ground It has a configuration.

【００１７】以上のような図１の点灯回路では、先ず、
コンバータ回路１が定電流回路２の端子間電圧が一定に
なるように出力電圧を制御する。定電流回路２は、リッ
プルによる変動が多少有るものの、安定化された電圧の
供給を受け、通過する電流ｉの値が一定になるよう電流
制御を行う。これにより発光ユニット３を通過する電流
は一定になり、各発光ダイオードＬＥＤ１１〜ＬＥＤ
１ｎは定電流駆動される。ここで、発光ユニット３と定
電流回路２を通過する電流ｉは定電流回路２の内部の電
流安定化作用により一定の値に保持される。このため発
光ユニット３を通過する電流は、抵抗Ｒ１を使用した時
に比べてコンバータ回路１の出力電圧のリップルや周囲
温度の影響をほとんど受けないものとなる。In the lighting circuit of FIG. 1 as described above, first,
Converter circuit 1 controls the output voltage so that the voltage between terminals of constant current circuit 2 becomes constant. The constant current circuit 2 receives the supply of the stabilized voltage although there is some fluctuation due to the ripple, and performs current control so that the value of the passing current i becomes constant. As a result, the current passing through the light emitting unit 3 becomes constant, and each of the light emitting diodes LED 11 to LED 11
1n is driven by a constant current. Here, the current i passing through the light emitting unit 3 and the constant current circuit 2 is kept at a constant value by the current stabilizing action inside the constant current circuit 2. Therefore, the current passing through the light emitting unit 3 is hardly affected by the ripple of the output voltage of the converter circuit 1 and the ambient temperature as compared with the case where the resistor R1 is used.

【００１８】図２は本発明の点灯回路の第１の実施例の
回路図であり、図１の概念をより具体化したものであ
る。すなわち、チョークコイルＬ１、スイッチングトラ
ンジスタＱ１、ダイオードＤ１、コンデンサＣ１、制御
回路ＤＲ１、誤差増幅器ＥＡ１および基準電圧源Ｖ
ｒｅｆにより、図７と同じコンバータ回路１ａを構成す
る。複数の発光ダイオードＬＥＤ１１〜ＬＥＤ１ｎを直
列に接続し、発光ユニット３を構成する。発光ユニット
３に定電流回路２ａを直列に接続し、この直列接続され
た発光ユニット３と定電流回路２ａをコンデンサＣ１に
対して並列に接続する。そして、発光ユニット３と定電
流回路２ａの接続点を、コンバータ回路１ａの出力検出
端子としての誤差増幅器ＥＡ１の第２の入力側に接続す
る。FIG. 2 shows a first embodiment of the lighting circuit according to the present invention.
FIG. 2 is a circuit diagram that further embodies the concept of FIG.
You. That is, the choke coil L1, the switching transformer
Transistor Q1, diode D1, capacitor C1, control
Circuit DR1, error amplifier EA1, and reference voltage source V
refForm the same converter circuit 1a as in FIG.
You. Multiple light emitting diode LED11~ LED1nDirectly
The light-emitting units 3 are connected to columns. Lighting unit
3 is connected in series with a constant current circuit 2a.
The light emitting unit 3 and the constant current circuit 2a to the capacitor C1
Connected in parallel. Then, the light emitting unit 3 and the constant current
The connection point of the flow circuit 2a is detected by the output of the converter circuit 1a.
Connected to the second input of the error amplifier EA1 as a terminal.
You.

【００１９】ここで定電流回路２ａについては以下のよ
うな回路構成とする。駆動電圧の供給点（ＶＤ）を電流
源ＣＳ１を介してＮＰＮ型のトランジスタＱ２のコレク
タに接続し、トランジスタＱ２のエミッタをグランドに
接続する。トランジスタＱ２のコレクタ、ベース間を短
絡し、トランジスタＱ２のベースにＮＰＮ型のトランジ
スタＱ３のベースを接続する。トランジスタＱ３のエミ
ッタをグランドに接続し、トランジスタＱ３のコレクタ
を発光ユニット３に接続する。このような構成の回路で
は、コンバータ回路１ａが動作し、コンデンサＣ１の端
子間電圧がコンバータ回路１ａの出力電圧として発光ユ
ニット３と定電流回路２ａの直列回路に供給される。な
お、コンバータ回路１ａの動作については図７の回路と
同じである。Here, the constant current circuit 2a has the following circuit configuration. The drive voltage supply point (V D ) is connected to the collector of the NPN transistor Q2 via the current source CS1, and the emitter of the transistor Q2 is connected to ground. The collector and base of the transistor Q2 are short-circuited, and the base of the transistor Q2 is connected to the base of an NPN transistor Q3. The emitter of the transistor Q3 is connected to the ground, and the collector of the transistor Q3 is connected to the light emitting unit 3. In the circuit having such a configuration, the converter circuit 1a operates, and the voltage between the terminals of the capacitor C1 is supplied to the series circuit of the light emitting unit 3 and the constant current circuit 2a as the output voltage of the converter circuit 1a. The operation of the converter circuit 1a is the same as that of the circuit of FIG.

【００２０】定電流回路２ａはトランジスタＱ２とＱ３
の接続構成によってカレントミラー定電流回路の形態と
なっている。このためトランジスタＱ３の主電流路に
は、トランジスタＱ２の主電流路を通過する電流と各ト
ランジスタＱ２とＱ３のエミッタ面積比によって決定さ
れる電流が流れる。トランジスタＱ２とＱ３のカレント
ミラー動作の結果として得られるこの電流は、周囲温度
やトランジスタＱ３のコレクタに印加される電圧の変動
に対して安定度の高いものとなる。勿論、コンバータ回
路１ａの出力電圧としてのコンデンサＣ１の端子間電圧
に多少のリップルが含まれていても電流の安定度にほと
んど影響は無い。したがって、発光ユニット３を構成す
る各発光ダイオードＬＥＤ１１〜ＬＥＤ１ｎは、トラン
ジスタＱ３の主電流路を通過する安定度の高い電流によ
って定電流駆動されることになる。The constant current circuit 2a includes transistors Q2 and Q3.
Is configured as a current mirror constant current circuit. Therefore, a current flowing through the main current path of the transistor Q2 and a current determined by the emitter area ratio of each transistor Q2 and Q3 flow through the main current path of the transistor Q3. This current, resulting from the current mirror operation of transistors Q2 and Q3, is highly stable with respect to ambient temperature and variations in the voltage applied to the collector of transistor Q3. Of course, even if the voltage between the terminals of the capacitor C1 as the output voltage of the converter circuit 1a includes some ripples, the stability of the current is hardly affected. Therefore, each of the light emitting diodes LED 11 to LED 1n constituting the light emitting unit 3 is driven at a constant current by a highly stable current passing through the main current path of the transistor Q3.

【００２１】図３には本発明の点灯回路の第２の実施例
の回路図を示した。図２に示す回路では、ｎ個全ての発
光ダイオードＬＥＤ１１〜ＬＥＤ１ｎを直列接続し、発
光ユニット３を構成していた。これに対して図３の回路
では、ｎ×ｍ個の発光ダイオードＬＥＤ１１〜ＬＥＤ
ｍｎをｎ個ずつ直列接続し、これによって得られたｍ個
の発光ダイオード列を並列に配置し、発光ユニット３ａ
を構成している。このような構成の発光ユニット３ａに
対応するため、図３の回路では、駆動電圧の供給点（Ｖ
Ｄ）に接続された電流源ＣＳ１と、電流源ＣＳ１にその
コレクタとベースとが接続されたＮＰＮ型のトランジス
タＱ１０と、トランジスタ１０のベースにそのベースが
接続されたｍ個のトランジスタＱ１１〜Ｑ１ｍによって
定電流回路２ｂを構成している。FIG. 3 is a circuit diagram of a lighting circuit according to a second embodiment of the present invention. In the circuit shown in FIG. 2, all the n light emitting diodes LED 11 to LED 1 n are connected in series to constitute the light emitting unit 3. On the other hand, in the circuit of FIG. 3, n × m light emitting diodes LED 11 to LED 11
mn are connected in series by n each, and the m light emitting diode rows obtained by this are arranged in parallel, and the light emitting unit 3a
Is composed. In order to support the light emitting unit 3a having such a configuration, in the circuit of FIG. 3, the drive voltage supply point (V
D ), a current source CS1 connected to the current source CS1, an NPN transistor Q10 having a collector and a base connected to the current source CS1, and m transistors Q11 to Q1m having a base connected to the base of the transistor 10. The constant current circuit 2b is configured.

【００２２】そして、例えば第１列目の発光ダイオード
列（ＬＥＤ１１〜ＬＥＤ１ｎ）にはトランジスタＱ１１
の主電流路を接続する、第２列目の発光ダイオード列
（ＬＥＤ２１〜ＬＥＤ２ｎ）にはトランジスタＱ１２の
主電流路を接続する、というように、発光ユニット３ａ
のｍ列有る発光ダイオード列のそれぞれに、１つづつ定
電流回路２ｂのトランジスタＱ１１〜Ｑ１ｍの主電流路
を接続する。このようにして接続された発光ユニット３
ａと定電流回路２ｂをコンバータ回路１ａのコンデンサ
Ｃ１に並列に接続する。第１列目の発光ダイオード列
（ＬＥＤ１１〜ＬＥＤ１ｎ）とトランジスタＱ１１の主
電流路の接続点を、コンバータ回路１ａ内に設けられた
誤差増幅器ＥＡ１の出力検出端子としての第２の入力側
に接続する。なお、コンバータ回路１ａの構成は図２、
図７の回路と同一とする。[0022] Then, for example, in the first column of the light emitting diode array (LED 11 ~LED 1n) transistor Q11
The main current path connecting, in the second row of light emitter diode array (LED 21 ~LED 2n) connecting the main current path of the transistor Q12, and so on, the light-emitting unit 3a of
The main current paths of the transistors Q11 to Q1m of the constant current circuit 2b are connected one by one to each of the m light emitting diode rows. Light emitting unit 3 connected in this way
a and the constant current circuit 2b are connected in parallel to the capacitor C1 of the converter circuit 1a. The connection point of the main current path of the first row of the light emitting diode line (LED 11 ~LED 1n) and transistors Q11, the second input of the output detecting terminal of the error amplifier EA1 provided in the converter circuit 1a Connecting. The configuration of the converter circuit 1a is shown in FIG.
It is the same as the circuit of FIG.

【００２３】このような図３の回路では、定電流回路２
ｂのトランジスタＱ１０とトランジスタＱ１１〜Ｑ１ｍ
がそれぞれカレントミラー回路を構成し、トランジスタ
Ｑ１１〜Ｑ１ｍの各主電流路にはカレントミラー動作に
よる安定度の高い電流が流れる。これに伴って発光ユニ
ット３ａを構成する第１から第ｍの各発光ダイオード列
にもカレントミラー動作による安定度の高い電流が流
れ、各発光ダイオードＬＥＤ１１〜ＬＥＤｍｎは定電流
駆動される。解決すべき課題の項の中でも述べているよ
うに、各発光ダイオードＬＥＤ１１〜ＬＥＤｍｎの順方
向電圧値のばらつきによって第１から第ｍの各発光ダイ
オード列の順方向電圧の合計値がかなり異なってしまう
ことがある。In the circuit shown in FIG. 3, the constant current circuit 2
b transistor Q10 and transistors Q11-Q1m
Constitute current mirror circuits, and a current having a high degree of stability due to the current mirror operation flows through each main current path of the transistors Q11 to Q1m. Current highly stable flow by the current mirror operation from the first constituting the light emitting unit 3a along with this to the light emitting diode rows of the m, the light-emitting diodes LED 11 ~LED mn is driven at a constant current. As described in the section of the problem to be solved, the total value of the forward voltage of each of the first to m-th light emitting diode columns is considerably different due to the variation of the forward voltage of each of the light emitting diodes LED 11 to LED mn. Sometimes.

【００２４】しかしカレントミラー回路においては、第
２のトランジスタの主電流路を流れる電流は、第１と第
２のトランジスタのエミッタ面積の比率と、コレクタ、
エミッタ間が接続された第１のトランジスタの主電流路
を流れる電流の大きさによってほぼ決定される。ここ
で、図３中のトランジスタＱ１０が第１のトランジス
タ、トランジスタＱ１１〜Ｑ１ｍが第２のトランジスタ
に相当する。このため、各トランジスタＱ１１〜Ｑ１ｍ
の主電流路を通過するそれぞれの電流の値は、実質的
に、各発光ダイオード列の順方向電圧の合計値の影響を
受けない。その結果、各発光ダイオードＬＥＤ１１〜Ｌ
ＥＤｍｎの順方向電圧値にばらつきがあっても、トラン
ジスタＱ１０〜Ｑ１ｍと電流源ＣＳ１の設定次第で、容
易に希望する値に設定することが可能となる。However, in the current mirror circuit, the current flowing through the main current path of the second transistor depends on the ratio of the emitter area of the first and second transistors, the collector,
It is substantially determined by the magnitude of the current flowing through the main current path of the first transistor connected between the emitters. Here, the transistor Q10 in FIG. 3 corresponds to a first transistor, and the transistors Q11 to Q1m correspond to second transistors. Therefore, each of the transistors Q11 to Q1m
Are substantially not affected by the sum of the forward voltages of the respective light emitting diode arrays. As a result, each of the light emitting diodes LED 11 to L
Even if the forward voltage value of ED mn varies, it can be easily set to a desired value depending on the settings of the transistors Q10 to Q1m and the current source CS1.

【００２５】また、従来の回路では、その出力電圧、す
なわちコンデンサＣ１の端子間電圧を安定化し、間接的
に、第１から第ｍの各発光ダイオード列を通過する電流
の安定化を図っていた。このような間接的な電流の安定
化では、フィードバック制御がなされていない第１列目
以外の各発光ダイオード列を通過する電流の値が、各発
光ダイオードＬＥＤ１１〜ＬＥＤｍｎの順方向電圧の変
化に伴って変わってしまう、という問題があった。しか
し図３の回路では、第１から第ｍの各発光ダイオード列
を通過する電流の安定化は、各発光ダイオード列に直列
に接続されたトランジスタＱ１１〜Ｑ１ｍのカレントミ
ラー動作によって直接的に行われる。このため、仮に、
周囲温度の変化によって各発光ダイオードＬＥＤ１１〜
ＬＥＤｍ ｎの順方向電圧値が変化しても、フィードバッ
ク制御がなされていない第１列目以外の各発光ダイオー
ド列を通過する電流の値が変化するということは無くな
る。In the conventional circuit, the output voltage, that is, the voltage between the terminals of the capacitor C1 is stabilized, and indirectly, the current passing through the first to m-th light emitting diode arrays is stabilized. . In such a stabilization of such indirect current value of the current passing through each light emitting diode rows other than the first row of the feedback control is not made, the change of the forward voltage of each light-emitting diode LED 11 ~LED mn There is a problem that changes with the. However, in the circuit of FIG. 3, the stabilization of the current passing through each of the first to m-th LED rows is directly performed by the current mirror operation of the transistors Q11 to Q1m connected in series to each of the LED rows. . For this reason, temporarily
Each light-emitting diodes LED 11 ~ by changes in ambient temperature
Be varied forward voltage value of the LED m n, it is eliminated that the value of current passing through each light emitting diode rows other than the first row of the feedback control is not performed is changed.

【００２６】なお、図３の回路では、コンバータ回路１
ａのフィードバック制御は、定電流回路２ｂの端子間電
圧を、カレントミラー回路が安定的に動作できるサチレ
ーション電圧以上の値で安定化するために行われる。こ
の定電流回路２ｂの端子間電圧を安定化することにより
定電流回路２ｂでのカレントミラー動作がほぼ一定の状
態で行われるようにする。そして、入力電圧や各発光ダ
イオード列の列毎の順方向電圧の合計値が変化した場合
にも定電流回路２ｂの動作と各発光ダイオードＬＥＤ
１１〜ＬＥＤｍｎの発光状態が不安定化することを防止
する。話が前後するが、図２の回路もこれに同じであ
る。In the circuit of FIG. 3, the converter circuit 1
The feedback control a is performed to stabilize the voltage between the terminals of the constant current circuit 2b at a value equal to or higher than the saturation voltage at which the current mirror circuit can operate stably. By stabilizing the voltage between the terminals of the constant current circuit 2b, the current mirror operation in the constant current circuit 2b is performed in a substantially constant state. The operation of the constant current circuit 2b and the operation of each light emitting diode LED are performed even when the input voltage or the total value of the forward voltage of each light emitting diode column changes.
11 to prevent the emission state of the LED mn from becoming unstable. Before and after, the circuit of FIG. 2 is the same.

【００２７】図４には本発明の点灯回路の第３の実施例
の回路図を示した。この図４に示す回路は、チョークコ
イルＬ１、スイッチングトランジスタＱ１、ダイオード
Ｄ１、コンデンサＣ１、制御回路ＤＲ１、誤差増幅器Ｅ
Ａ１および基準電圧源Ｖｒｅｆによりコンバータ回路１
ｂを構成する。なお、図２、図７のコンバータ回路１ａ
では、誤差増幅器ＥＡ１の第１の入力側は基準電圧源Ｖ
ｒｅ ｆを介してグランドに接続されていた。これに対
し、図４のコンバータ回路１ｂでは、誤差増幅器ＥＡ１
の第１の入力側は基準電圧源Ｖｒｅｆを介してコンデン
サＣ１とダイオードＤ１の接続点に接続する。その他の
コンバータ回路１ｂの回路部分については図２、６のコ
ンバータ回路１ａと同一である。FIG. 4 is a circuit diagram of a lighting circuit according to a third embodiment of the present invention. The circuit shown in FIG. 4 includes a choke coil L1, a switching transistor Q1, a diode D1, a capacitor C1, a control circuit DR1, and an error amplifier E.
A1 and the reference voltage source Vref , the converter circuit 1
b. The converter circuit 1a shown in FIGS.
Then, the first input of the error amplifier EA1 is connected to the reference voltage source V
It had been connected to the ground via the re f. On the other hand, in the converter circuit 1b of FIG.
Is connected to the connection point of the capacitor C1 and the diode D1 via the reference voltage source Vref . The other circuit parts of the converter circuit 1b are the same as those of the converter circuit 1a of FIGS.

【００２８】複数の発光ダイオードＬＥＤ１１〜ＬＥＤ
１ｎを直列に接続し、発光ユニット３を構成する。発光
ユニット３に定電流回路２ｃを直列に接続し、この直列
接続された発光ユニット３と定電流回路２ｃを、発光ユ
ニット３がグランド側となるようにコンバータ回路１ｂ
のコンデンサＣ１に対して並列に接続する。ここで、コ
ンバータ回路１ｂのコンデンサＣ１とダイオードＤ１の
接続点にＰＮＰ型のトランジスタＱ４とＱ５の各エミッ
タを接続し、トランジスタＱ４とＱ５の各ベースを共通
接続する。トランジスタＱ４のコレクタは電流源ＣＳ２
を介してグランドに接続し、トランジスタＱ５のコレク
タは発光ユニット３に接続する。トランジスタＱ４のコ
レクタ、ベース間を接続し、このトランジスタＱ４、Ｑ
５および電流源ＣＳ２により定電流回路２ｃを構成す
る。A plurality of light emitting diodes LED 11 to LED
1n are connected in series to form the light emitting unit 3. A constant current circuit 2c is connected to the light emitting unit 3 in series, and the light emitting unit 3 and the constant current circuit 2c connected in series are connected to the converter circuit 1b so that the light emitting unit 3 is on the ground side.
Is connected in parallel to the capacitor C1. Here, the emitters of the PNP transistors Q4 and Q5 are connected to the connection point between the capacitor C1 and the diode D1 of the converter circuit 1b, and the bases of the transistors Q4 and Q5 are commonly connected. The collector of the transistor Q4 is a current source CS2
And the collector of the transistor Q5 is connected to the light emitting unit 3. The collector and the base of the transistor Q4 are connected, and the transistors Q4 and Q
5 and the current source CS2 constitute a constant current circuit 2c.

【００２９】この図４の回路は、実質的に、図２の回路
の発光ユニット３と定電流回路２ａの接続位置を逆にす
るよう構成したものであり、その概略の動作は図２の回
路とほぼ同じになる。そして、図４においても、発光ユ
ニット３を通過する電流の安定化は定電流回路２ｃのカ
レントミラー動作によって行われる。また、図４のコン
バータ回路１ｂのフィードバック制御は、定電流回路２
ｃの端子間電圧をカレントミラー回路のサチレーション
電圧以上の値で安定化するために行われる。ちなみに、
図４の回路では、発光ユニット３の一端がグランドに接
続された回路形態となっている。配線基板上ではグラン
ドの導体パターンは至る所に配置されている。このた
め、図４の回路は図２の回路に比べて発光ユニット３を
配線基板上に配置する上で自由度が高いという利点があ
る。The circuit shown in FIG. 4 is constructed so that the connection position between the light emitting unit 3 and the constant current circuit 2a in the circuit shown in FIG. 2 is substantially reversed. Is almost the same as In FIG. 4, the current passing through the light emitting unit 3 is stabilized by the current mirror operation of the constant current circuit 2c. The feedback control of the converter circuit 1b of FIG.
This is performed to stabilize the voltage between the terminals c at a value equal to or higher than the saturation voltage of the current mirror circuit. By the way,
The circuit in FIG. 4 has a circuit configuration in which one end of the light emitting unit 3 is connected to the ground. On the wiring board, ground conductor patterns are arranged everywhere. Therefore, the circuit of FIG. 4 has an advantage that the degree of freedom in arranging the light emitting unit 3 on the wiring board is higher than that of the circuit of FIG.

【００３０】図５には本発明の点灯回路の第４の実施例
の回路図を示した。今まで説明した図２から図４の中に
示されたコンバータ回路（１ａ、１ｂ）は昇圧チョッパ
型のコンバータの構成であった。これに対して図５のコ
ンバータ回路１ｃは降圧チョッパ型のコンバータの構成
となっている。すなわち、ＰＮＰ型のスイッチングトラ
ンジスタＱ６のエミッタを電源供給点（ＶＩＮ）に接続
し、そのコレクタをチョークコイルＬ２の一端に接続す
る。チョークコイルＬ２の一端には、アノードがグラン
ドに接続されたダイオードＤ２のカソードを接続し、チ
ョークコイルＬ２の他端には、他端がグランドに接続さ
れたコンデンサＣ２の一端を接続する。FIG. 5 is a circuit diagram of a lighting circuit according to a fourth embodiment of the present invention. The converter circuits (1a, 1b) shown in FIGS. 2 to 4 described so far have the configuration of a boost chopper type converter. On the other hand, the converter circuit 1c of FIG. 5 has a configuration of a step-down chopper type converter. That is, the emitter of the PNP-type switching transistor Q6 is connected to the power supply point (V IN ), and its collector is connected to one end of the choke coil L2. One end of the choke coil L2 is connected to the cathode of a diode D2 whose anode is connected to the ground, and the other end of the choke coil L2 is connected to one end of a capacitor C2 whose other end is connected to the ground.

【００３１】スイッチングトランジスタＱ６のベースは
制御回路ＤＲ２に接続する。制御回路ＤＲ２はさらに誤
差増幅器ＥＡ２の出力側と接続し、誤差増幅器ＥＡ２の
２つある入力側のうちの第１の入力側とグランドの間に
基準電圧源Ｖｒｅｆを接続する。このスイッチングトラ
ンジスタＱ６、チョークコイルＬ２、ダイオードＤ２、
コンデンサＣ２、制御回路ＤＲ２、誤差増幅器ＥＡ２お
よび基準電圧源Ｖｒｅ ｆによりコンバータ回路１ｃを構
成する。発光ユニット３と定電流回路２ａを直列に接続
し、この直列接続された発光ユニット３と定電流回路２
ａをコンデンサＣ２に対して並列に接続する。そして、
発光ユニット３と定電流回路２ａの接続点を誤差増幅器
ＥＡ２の２つある入力側のうちの第２の入力側に接続す
る。なお、発光ユニット３と定電流回路２ａの構成は図
２の回路と同一である。The base of the switching transistor Q6 is connected to the control circuit DR2. The control circuit DR2 further connects to the output side of the error amplifier EA2, and connects the reference voltage source Vref between the first input side of the two input sides of the error amplifier EA2 and ground. This switching transistor Q6, choke coil L2, diode D2,
Capacitor C2, the control circuit DR2, constituting the converter circuit 1c by an error amplifier EA2 and the reference voltage source V re f. The light emitting unit 3 and the constant current circuit 2a are connected in series, and the light emitting unit 3 and the constant current circuit 2
a is connected in parallel to the capacitor C2. And
The connection point between the light emitting unit 3 and the constant current circuit 2a is connected to the second input side of the two input sides of the error amplifier EA2. The configurations of the light emitting unit 3 and the constant current circuit 2a are the same as those of the circuit of FIG.

【００３２】このような構成とした図５の回路は、コン
バータ回路１ｃが降圧型のため、入力電圧ＶＩＮが発光
ユニット３を構成する発光ダイオードＬＥＤ１１〜ＬＥ
Ｄ１ ｎの順方向電圧の合計値よりもはるかに高い場合に
使用される。ここで、コンバータ回路１ｃは、スイッチ
ングトランジスタＱ６が制御回路ＤＲ２からの駆動信号
に応じてオン、オフ動作を繰り返し、電流を断続する。
トランジスタＱ６を通過したパルス状の電流を、チョー
クコイルＬ２とダイオードＤ２とコンデンサＣ２によっ
て平滑し、直流に変換する。この時、コンデンサＣ２の
端子間に生じた電圧をコンバータ回路１ｃの出力電圧と
して発光ユニット３と定電流回路２ａに供給する。In the circuit of FIG. 5 having such a configuration, since the converter circuit 1c is a step-down type, the input voltage VIN is equal to the light emitting diodes LED 11 to LE constituting the light emitting unit 3.
Used when it is much higher than the sum of the forward voltages of D 1 n . Here, in the converter circuit 1c, the switching transistor Q6 repeats the on / off operation in response to the drive signal from the control circuit DR2, and interrupts the current.
The pulse-shaped current passing through the transistor Q6 is smoothed by the choke coil L2, the diode D2, and the capacitor C2, and is converted into a direct current. At this time, the voltage generated between the terminals of the capacitor C2 is supplied to the light emitting unit 3 and the constant current circuit 2a as the output voltage of the converter circuit 1c.

【００３３】図２と図５の回路は、それぞれ定電流回路
２ａと発光ユニット３の回路構成が同一であるため、定
電流回路２ａの動作と作用も同じものとなる。したがっ
て、図５の回路においても発光ユニット３を通過する電
流の安定化は定電流回路２ａのカレントミラー動作によ
って行われる。また、図５のコンバータ回路１ｃのフィ
ードバック制御は、定電流回路２ａの端子間電圧をカレ
ントミラー回路のサチレーション電圧以上の値で安定化
するために行われることになる。Since the circuits of FIGS. 2 and 5 have the same circuit configuration of the constant current circuit 2a and the light emitting unit 3, respectively, the operation and operation of the constant current circuit 2a are the same. Therefore, also in the circuit of FIG. 5, the stabilization of the current passing through the light emitting unit 3 is performed by the current mirror operation of the constant current circuit 2a. The feedback control of the converter circuit 1c in FIG. 5 is performed to stabilize the voltage between the terminals of the constant current circuit 2a at a value equal to or higher than the saturation voltage of the current mirror circuit.

【００３４】図６には本発明の点灯回路の第５の実施例
の回路図を示した。図２から図６の各回路では、定電流
回路をカレントミラー回路を使用して構成していた。こ
れに対して図５の回路では、誤差増幅器ＥＡ３を使用し
て定電流回路２ｄを構成している。すなわち、発光ユニ
ット３にＮＰＮ型のトランジスタＱ７のコレクタを接続
し、トランジスタＱ７のエミッタを抵抗ＲＤを介してグ
ランドに接続する。誤差増幅器ＥＡ３を設け、誤差増幅
器ＥＡ３の出力側をトランジスタＱ７のベースに接続す
る。誤差増幅器ＥＡ３の２つある入力側のうちの第１の
入力側をトランジスタＱ７と抵抗ＲＤの接続点に接続
し、第２の入力側を基準電圧源Ｖｒｅｆ２を介してグラ
ンドに接続する。このトランジスタＱ７、抵抗ＲＤ、誤
差増幅器ＥＡ３および基準電圧源Ｖｒｅｆ２により、定
電流回路２ｄを構成する。なお、コンバータ回路１ａと
発光ユニット３については図２の回路と同じ構成であ
る。FIG. 6 is a circuit diagram of a lighting circuit according to a fifth embodiment of the present invention. In each of the circuits of FIGS. 2 to 6, the constant current circuit is configured using a current mirror circuit. On the other hand, in the circuit of FIG. 5, the constant current circuit 2d is configured using the error amplifier EA3. That is, the collector of the NPN transistor Q7 is connected to the light emitting unit 3, and the emitter of the transistor Q7 is connected to the ground via the resistor RD. An error amplifier EA3 is provided, and the output side of the error amplifier EA3 is connected to the base of the transistor Q7. A first input side of the two input sides of the error amplifier EA3 is connected to a connection point between the transistor Q7 and the resistor RD, and a second input side is connected to the ground via the reference voltage source Vref2 . The transistor Q7, resistors RD, the error amplifier EA3 and a reference voltage source V ref2, constitute a constant current circuit 2d. Note that the converter circuit 1a and the light emitting unit 3 have the same configuration as the circuit in FIG.

【００３５】このような構成とした図６の回路の場合、
定電流回路２ｄの内部では、抵抗ＲＤの端子間電圧がほ
ぼ基準電圧源Ｖｒｅｆ２の出力電圧と同じになるよう、
誤差増幅器ＥＡ３とトランジスタＱ７が動作する。ここ
で、抵抗ＲＤの端子間電圧がほぼ基準電圧源Ｖｒｅｆ２
の出力電圧と同じ値に一定に保たれれば、抵抗ＲＤおよ
びトランジスタＱ７の主電流路を通過する電流は一定と
なる。これにより、抵抗ＲＤ、トランジスタＱ７の主電
流路と直列接続の状態にある発光ユニット３を通過する
電流も一定となり、各発光ダイオードＬＥＤ１１〜ＬＥ
Ｄ１ｎは定電流にて駆動されることになる。なお、コン
バータ回路１ａのフィードバック制御は、今までの回路
と同様に、定電流回路２ｄの端子間電圧を、定電流回路
２ｄが安定した動作を行うことが可能なサチレーション
電圧以上の値で安定化するために行われる。In the case of the circuit of FIG. 6 having such a configuration,
Inside the constant current circuit 2d, the voltage between the terminals of the resistor RD is substantially equal to the output voltage of the reference voltage source Vref2 .
The error amplifier EA3 and the transistor Q7 operate. Here, the voltage between the terminals of the resistor RD is substantially equal to the reference voltage source V ref2.
, The current passing through the resistor RD and the main current path of the transistor Q7 becomes constant. As a result, the current passing through the light emitting unit 3 connected in series with the resistor RD and the main current path of the transistor Q7 is also constant, and each of the light emitting diodes LED 11 to LE 11
D 1n is driven by a constant current. In the feedback control of the converter circuit 1a, the voltage between the terminals of the constant current circuit 2d is stabilized at a value equal to or higher than the saturation voltage at which the constant current circuit 2d can perform a stable operation, as in the conventional circuits. Done to do so.

【００３６】以上の実施例の説明では、コンバータ回路
に非絶縁型のスイッチングレギュレータを使用した場合
を想定した。しかし、コンバータ回路にトランスによる
絶縁型のスイッチングレギュレータを使用しても良い。
また、各実施例の回路では、コンバータ回路が誤差増幅
器を有し、かつ他励式のものとなっている。しかし、誤
差増幅器ＥＡ１、ＥＡ２に代えてエラーコンパレータを
使用したコンバータ回路、あるいは自励式のコンバータ
回路をなど使用しても構わない。図２、３、４、５の回
路では、定電流回路を、第１のトランジスタ（Ｑ２、Ｑ
４、Ｑ１０）のコレクタ、ベース間を接続した最も基本
的なカレントミラー回路によって構成しているが、ウィ
ルソン型、電流増幅型など、他の形態のカレントミラー
回路によって構成しても良い。勿論、定電流回路を構成
するトランジスタにバイポーラ型以外のトランジスタ、
具体的にはＭＯＳＦＥＴ等、を使用しても構わない。In the above description of the embodiment, it is assumed that a non-insulated switching regulator is used for the converter circuit. However, an insulating switching regulator using a transformer may be used for the converter circuit.
In each of the circuits of the embodiments, the converter circuit has an error amplifier and is of a separately excited type. However, a converter circuit using an error comparator or a self-excited converter circuit may be used instead of the error amplifiers EA1 and EA2. In the circuits of FIGS. 2, 3, 4, and 5, the constant current circuit is connected to the first transistors (Q2, Q2).
4, Q10) is constituted by the most basic current mirror circuit connected between the collector and the base, but may be constituted by another form of current mirror circuit such as a Wilson type or a current amplification type. Of course, the transistors constituting the constant current circuit are not bipolar transistors,
Specifically, a MOSFET or the like may be used.

【００３７】図２、３、５において、定電流回路（２
ａ、２ｂ）を構成する電流源ＣＳ１の一端は駆動電源供
給点（ＶＤ）に接続することとしている。しかし、定電
流回路（２ａ、２ｂ）と発光ユニット（３、３ａ）の接
続点の電圧に高い安定度が得られる場合、電流源ＣＳ１
の一端は前記接続点に接続しても良い。そして図６にお
いては、定電流回路２ｄに誤差増幅器を用いた最も基本
的な定電流回路を使用している。しかし、温度特性を補
償した形態のものなど、その回路構成が図６と異なった
誤差増幅器型の定電流回路を使用しても良い。実施例と
して示した回路の変形は、本発明の要旨を変更しない範
囲であれば、当然、可能である。In FIGS. 2, 3, and 5, the constant current circuit (2
a, 2b), one end of the current source CS1 is connected to the drive power supply point (V D ). However, if high stability is obtained in the voltage at the connection point between the constant current circuits (2a, 2b) and the light emitting units (3, 3a), the current source CS1
May be connected to the connection point. In FIG. 6, the most basic constant current circuit using an error amplifier is used as the constant current circuit 2d. However, a constant current circuit of an error amplifier type having a circuit configuration different from that of FIG. Modifications of the circuit shown as the embodiment are naturally possible as long as the gist of the present invention is not changed.

【００３８】[0038]

【発明の効果】本発明による点灯回路は、少なくとも１
つの発光ダイオードからなる発光ユニットに定電流回路
を直列接続する。そして、当該発光ユニットと定電流回
路の直列回路に対して、コンバータ回路から、定電流回
路の端子間電圧が一定になるよう出力電圧を制御しなが
ら直流電力を供給する構成を特徴としている。このよう
な構成によれば、発光ユニットを構成する各発光ダイオ
ードは、定電流回路内の制御動作によって得られる安定
度の高い電流によって定電流駆動される。ここでコンバ
ータ回路は、定電流回路の端子間電圧を、その定電流回
路が安定して動作することが可能なサチレーション電圧
以上の値で安定化し、入力電圧や直列接続された発光ダ
イオードの順方向電圧の合計値の変化によって定電流回
路の動作と各発光ユニットの発光状態が不安定化するこ
とを防止する。The lighting circuit according to the present invention has at least one
A constant current circuit is connected in series to a light emitting unit including two light emitting diodes. Then, a DC power is supplied to the series circuit of the light emitting unit and the constant current circuit from the converter circuit while controlling the output voltage so that the voltage between the terminals of the constant current circuit becomes constant. According to such a configuration, each of the light emitting diodes constituting the light emitting unit is driven at a constant current by a highly stable current obtained by a control operation in the constant current circuit. Here, the converter circuit stabilizes the voltage between the terminals of the constant current circuit at a value equal to or higher than the saturation voltage at which the constant current circuit can operate stably, and adjusts the input voltage and the forward direction of the light emitting diodes connected in series. This prevents the operation of the constant current circuit and the light emitting state of each light emitting unit from becoming unstable due to a change in the total value of the voltages.

【００３９】また、発光ユニットを通過する電流は、抵
抗を使用する従来の回路に比べてコンバータ回路の出力
電圧のリップルの影響をほとんど受けないものとなる。
そして、発光ダイオードを１列当たりｎ個直列接続して
それを並列にｍ列配置して発光ユニットを構成した場
合、各発光ダイオードの順方向電圧値にばらつきがあっ
ても、定電流回路を構成する素子の特性値の設定次第
で、容易かつ正確に希望する値に設定することが可能と
なる。また、周囲温度の変化によって各発光ダイオード
の特性値が変化しても、フィードバック制御がなされて
いない第１列目以外の各発光ダイオード列を通過する電
流の値が変化するということも無くなる。従って、本発
明によれば、発光ダイオードに安定した電流を流すこと
ができ、しかもその電流値を正確かつ容易に設定できる
点灯回路が提供できる。The current passing through the light emitting unit is hardly affected by the ripple of the output voltage of the converter circuit as compared with the conventional circuit using a resistor.
When n light emitting diodes are connected in series per row and arranged in m rows in parallel to form a light emitting unit, a constant current circuit is formed even if the forward voltage value of each light emitting diode varies. Depending on the setting of the characteristic value of the element, the desired value can be easily and accurately set to a desired value. Further, even if the characteristic value of each light emitting diode changes due to a change in the ambient temperature, the value of the current passing through each light emitting diode row other than the first row in which the feedback control is not performed does not change. Therefore, according to the present invention, it is possible to provide a lighting circuit that allows a stable current to flow through the light emitting diode and that can set the current value accurately and easily.

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

【図１】 本発明の基本概念に基づく点灯回路のブロッ
ク図。FIG. 1 is a block diagram of a lighting circuit based on a basic concept of the present invention.

【図２】 本発明による点灯回路の第１の実施例の回路
図。FIG. 2 is a circuit diagram of a lighting circuit according to a first embodiment of the present invention.

【図３】 本発明による点灯回路の第２の実施例の回路
図。FIG. 3 is a circuit diagram of a lighting circuit according to a second embodiment of the present invention.

【図４】 本発明による点灯回路の第３の実施例の回路
図。FIG. 4 is a circuit diagram of a third embodiment of the lighting circuit according to the present invention.

【図５】 本発明による点灯回路の第４の実施例の回路
図。FIG. 5 is a circuit diagram of a fourth embodiment of the lighting circuit according to the present invention.

【図６】 本発明による点灯回路の第５の実施例の回路
図。FIG. 6 is a circuit diagram of a lighting circuit according to a fifth embodiment of the present invention.

【図７】 従来の一例の点灯回路の回路図。FIG. 7 is a circuit diagram of an example of a conventional lighting circuit.

【図８】 発光ダイオードの数が多い場合における発光
ユニットの構成と、発光ユニットと抵抗の接続構成を示
す回路図。FIG. 8 is a circuit diagram showing a configuration of a light emitting unit in a case where the number of light emitting diodes is large, and a connection configuration of a light emitting unit and a resistor.

【符号の説明】[Explanation of symbols]

１：コンバータ回路 １ａ〜１ｃ：コンバータ回路
（具体回路） ２：定電流回路 ２ａ〜２ｄ：
定電流回路（具体回路） ３、３ａ：発光ユニット
ＣＳ１、ＣＳ２：電流源 Ｑ２、Ｑ１０：ト
ランジスタ（第１のトランジスタ） Ｑ３、Ｑ１１
〜Ｑ１ｍ：トランジスタ（第２のトランジスタ）
（ＶＩＮ）：電源供給点 （ＶＤ）：駆動電圧供給
点1: Converter circuit 1a to 1c: Converter circuit (specific circuit) 2: Constant current circuit 2a to 2d:
Constant current circuit (specific circuit) 3, 3a: light emitting unit CS1, CS2: current source Q2, Q10: transistor (first transistor) Q3, Q11
To Q1m: transistor (second transistor)
(V IN ): Power supply point (V D ): Drive voltage supply point

フロントページの続き Ｆターム(参考） 3K073 AA12 AA25 AA75 BA09 CG02 CJ17 5C080 AA07 BB03 CC07 DD20 DD30 FF03 FF08 HH14 JJ03 KK52 5F041 BB10 BB23 BB24 BB26 BB32 5H730 AA02 AA14 AS02 BB14 DD02 DD21 DD26 EE18 FD31 FF15 FG01 Continued on the front page F-term (reference) 3K073 AA12 AA25 AA75 BA09 CG02 CJ17 5C080 AA07 BB03 CC07 DD20 DD30 FF03 FF08 HH14 JJ03 KK52 5F041 BB10 BB23 BB24 BB26 BB32 5H730 AA02 AA15 BB21 BB14 DD02

Claims (6)

【特許請求の範囲】[Claims] 【請求項１】 少なくとも１つの発光ダイオードからな
る発光ユニットに対し、該発光ダイオードが点灯するの
に必要な直流電力を供給する点灯回路において、 該発光ユニットに対して直列に接続される定電流回路
と、 該定電流回路の端子間電圧が一定になるよう出力電圧を
制御しながら、該発光ユニットと該定電流回路の直列回
路に直流電力を供給するコンバータ回路とを具備するこ
とを特徴とする点灯回路。1. A lighting circuit for supplying, to a light emitting unit comprising at least one light emitting diode, DC power required for lighting the light emitting diode, a constant current circuit connected in series to the light emitting unit And a converter circuit for supplying DC power to a series circuit of the light emitting unit and the constant current circuit while controlling an output voltage so that a voltage between terminals of the constant current circuit becomes constant. Lighting circuit. 【請求項２】 前記定電流回路は、 電流源と、 該電流源にその主電流路が直列に接続された第１のトラ
ンジスタと、 前記発光ユニットにその主電流路が直列に接続され、該
第１のトランジスタの制御端子にその制御端子が接続さ
れた第２のトランジスタとを具備することを特徴とす
る、請求項１に記載した点灯回路。2. The constant current circuit, comprising: a current source; a first transistor having a main current path connected in series to the current source; and a main current path connected in series to the light emitting unit; The lighting circuit according to claim 1, further comprising a second transistor having a control terminal connected to the control terminal of the first transistor. 【請求項３】 前記定電流回路は、 前記発光ユニットに直列接続された第３のトランジスタ
と、 該発光ユニットを流れる電流に応じて該第３のトランジ
スタの導通状態を制御する誤差増幅器とを具備すること
を特徴とする、請求項１に記載した点灯回路。3. The constant current circuit includes: a third transistor connected in series to the light emitting unit; and an error amplifier that controls a conduction state of the third transistor in accordance with a current flowing through the light emitting unit. The lighting circuit according to claim 1, wherein: 【請求項４】 前記コンバータ回路は、前記定電流回路
の端子間電圧を、該定電流回路が所定の大きさの電流を
安定的に流すことができるサチレーション電圧以上の電
圧値に保持することを特徴とする、請求項１から請求項
３のいずれかに記載した点灯回路。4. The converter circuit holds the voltage between terminals of the constant current circuit at a voltage value equal to or higher than a saturation voltage at which the constant current circuit can stably flow a current of a predetermined magnitude. The lighting circuit according to any one of claims 1 to 3, characterized in that: 【請求項５】 複数の発光ダイオードを直列接続してな
るダイオード列を複数並設した発光ユニットに対して、
該発光ダイオードが点灯するのに必要な直流電力を供給
する点灯回路において、 電流源と、該電流源にその主電流路が直列に接続された
第１のトランジスタと、該発光ユニットの各ダイオード
列にそれぞれ主電流路が接続され、該第１のトランジス
タの制御端子に各制御端子が接続された複数個の第２の
トランジスタとを有する定電流回路と、 所定のダイオード列と第２のトランジスタの接続点の電
圧を検出し、該所定の第２のトランジスタの主電流路の
端子間電圧が一定になるよう出力電圧を制御しながら、
それぞれのダイオード列と第２のトランジスタの直列回
路に直流電力を供給するコンバータ回路とを具備するこ
とを特徴とする点灯回路。5. A light emitting unit in which a plurality of diode rows formed by connecting a plurality of light emitting diodes in series are arranged in parallel.
In a lighting circuit for supplying DC power required for lighting the light emitting diode, a current source, a first transistor having a main current path connected in series to the current source, and each diode row of the light emitting unit A constant current circuit having a plurality of second transistors each having a main current path connected to each of the control terminals of the first transistor and a control terminal connected to each of the control terminals; While detecting the voltage at the connection point and controlling the output voltage so that the voltage between the terminals of the main current path of the predetermined second transistor becomes constant,
A lighting circuit, comprising: a converter circuit that supplies DC power to a series circuit of each diode row and a second transistor. 【請求項６】 前記コンバータ回路は、前記所定の第２
のトランジスタの主電流路の端子間電圧を、該所定の第
２のトランジスタが所定の大きさの電流を安定して流す
ことのできるサチレーション電圧以上の電圧値に保持す
ることを特徴とする、請求項５に記載した点灯回路。6. The converter circuit according to claim 1, wherein
The terminal voltage of the main current path of the transistor is maintained at a voltage value equal to or higher than a saturation voltage at which the predetermined second transistor can stably flow a current of a predetermined magnitude. Item 6. The lighting circuit according to Item 5.
JP2000027099A 2000-02-04 2000-02-04 Lighting circuit Pending JP2001215913A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000027099A JP2001215913A (en) 2000-02-04 2000-02-04 Lighting circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000027099A JP2001215913A (en) 2000-02-04 2000-02-04 Lighting circuit

Publications (1)

Publication Number Publication Date
JP2001215913A true JP2001215913A (en) 2001-08-10

Family

ID=18552733

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2000027099A Pending JP2001215913A (en) 2000-02-04 2000-02-04 Lighting circuit

Country Status (1)

Country Link
JP (1) JP2001215913A (en)

Cited By (83)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003215534A (en) * 2002-01-23 2003-07-30 Seiko Epson Corp Backlight control device for liquid crystal display
WO2003096436A1 (en) * 2002-05-07 2003-11-20 Rohm Co., Ltd. Light emitting element drive device and electronic device having light emitting element
FR2845328A1 (en) * 2002-10-08 2004-04-09 Koito Mfg Co Ltd Multi-function lamp for motor vehicles, uses switch-mode control of transistor supplying light source to determine light output to suit particular motor vehicle lamp application
JP2005010779A (en) * 2003-06-20 2005-01-13 Samsung Electronics Co Ltd High-efficiency power supply apparatus for display panel driving system and designing method thereof
US6847169B2 (en) 2002-10-08 2005-01-25 Koito Manufacturing Co., Ltd. Lighting circuit
JP2005027432A (en) * 2003-07-02 2005-01-27 Toko Inc Switching constant current power supply unit
US6867557B2 (en) 2002-10-08 2005-03-15 Koito Manufacturing Co., Ltd. Lighting circuit
JP2005073352A (en) * 2003-08-22 2005-03-17 Toko Inc Switching-type constant current power supply
US6876153B2 (en) 2002-10-15 2005-04-05 Koito Manufacturing Co., Ltd. Switching regulator circuit and vehicular lamp
JP2005136157A (en) * 2003-10-30 2005-05-26 Rohm Co Ltd Light emitting element driving device, display module having same driving device, and electronic device having same module
US6930472B2 (en) 2002-10-15 2005-08-16 Koito Manufacturing Co., Ltd. Switching regulator circuit
US6989635B2 (en) 2002-10-01 2006-01-24 Koito Manufacturing Co., Ltd. Vehicular lamp with current limiting circuit
WO2006018923A1 (en) * 2004-08-17 2006-02-23 Rohm Co., Ltd Power supply apparatus
US7034607B2 (en) 2003-04-28 2006-04-25 Toko Kabushiki Kaisha Switching constant-current power device
WO2006059500A1 (en) * 2004-12-03 2006-06-08 Rohm Co., Ltd Power supply device, light emitting device using such power supply device, and electronic device
JP2006185942A (en) * 2004-12-24 2006-07-13 Toshiba Matsushita Display Technology Co Ltd Surface light source controller
US7081708B2 (en) 2002-10-15 2006-07-25 Koito Manufacturing Co., Ltd. Lighting circuit
JP2006228529A (en) * 2005-02-16 2006-08-31 Matsushita Electric Works Ltd Illumination apparatus
US7106037B2 (en) 2003-07-02 2006-09-12 Toko, Inc. Switching-type constant current power supply device
JP2006301027A (en) * 2005-04-15 2006-11-02 Avix Inc Color sequential led driving circuit
JP2006303214A (en) * 2005-04-21 2006-11-02 Sony Corp Led drive
JP2006320194A (en) * 2006-07-31 2006-11-24 Ricoh Co Ltd Power-supply circuit
JP2006345691A (en) * 2006-07-31 2006-12-21 Ricoh Co Ltd Charge pumping circuit
JP2007005014A (en) * 2005-06-21 2007-01-11 Toshiba Matsushita Display Technology Co Ltd Illumination device and liquid crystal display device
JP2007082347A (en) * 2005-09-15 2007-03-29 Ricoh Co Ltd Anomalous connection detection circuit and driving device equipped with anomalous connection detection circuit
JP2007086778A (en) * 2005-09-16 2007-04-05 Samsung Electronics Co Ltd Display device
JP2007095907A (en) * 2005-09-28 2007-04-12 Ricoh Co Ltd Driving circuit and electronic apparatus using the same
JP2007129862A (en) * 2005-11-07 2007-05-24 Rohm Co Ltd Power supply unit
JP2007236095A (en) * 2006-02-28 2007-09-13 Ccs Inc Power supply for led and light irradiation apparatus
US7301284B2 (en) 2004-09-17 2007-11-27 Koito Manufacturing Co., Ltd. Lighting control circuit for vehicle lighting equipment
JP2007318983A (en) * 2006-05-24 2007-12-06 Power Integrations Inc Method and arrangement for supplying power to light emitting diode array
JP2007328535A (en) * 2006-06-07 2007-12-20 Rohm Co Ltd Power supply device, and electronic device using the same
US7322718B2 (en) 2003-01-27 2008-01-29 Matsushita Electric Industrial Co., Ltd. Multichip LED lighting device
JP2008509649A (en) * 2004-08-09 2008-03-27 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Power converter, integrated circuit including power converter, device including power converter, and power conversion method
US7388560B2 (en) 2003-08-29 2008-06-17 Rohm Co., Ltd. Power supply apparatus
JP2008533967A (en) * 2005-03-18 2008-08-21 オーストリアマイクロシステムス アーゲー Voltage converter apparatus and method for supplying voltage to electrical load
JP2008533966A (en) * 2005-03-18 2008-08-21 オーストリアマイクロシステムス アーゲー Voltage converter apparatus and method for supplying voltage to electrical load
JP2008192625A (en) * 2008-04-17 2008-08-21 Koito Mfg Co Ltd Lighting circuit
JP2008295009A (en) * 2007-05-22 2008-12-04 Renyo Handotai Kofun Yugenkoshi Constant current driving circuit
JP2008300208A (en) * 2007-05-31 2008-12-11 Toshiba Lighting & Technology Corp Luminaire
JP2009004788A (en) * 2007-06-21 2009-01-08 Dongbu Hitek Co Ltd Light emitting diode driving circuit
JP2009016280A (en) * 2007-07-06 2009-01-22 Nec Lcd Technologies Ltd Light emission control circuit, light emission control method, surface lighting apparatus, and liquid crystal display device with the surface lighting apparatus
US7541785B2 (en) 2003-07-07 2009-06-02 Rohm Co., Ltd. Load driving device and portable apparatus utilizing such driving device
JP2009290183A (en) * 2008-05-30 2009-12-10 Green Solution Technology Inc Light emitting diode driving circuit and controller thereof
KR100935055B1 (en) 2007-12-10 2009-12-31 산켄덴키 가부시키가이샤 Light emitting device driving device and electronic device using the device
JP2010055843A (en) * 2008-08-26 2010-03-11 Panasonic Electric Works Co Ltd Illumination lighting device, lighting system and luminaire
JP2010086826A (en) * 2008-09-30 2010-04-15 Kyocera Corp Light source device and display
JP2010119200A (en) * 2008-11-12 2010-05-27 Yamatake Corp Current output circuit
US7741788B2 (en) 2007-02-22 2010-06-22 Koito Manufacturing Co., Ltd. Light emitting apparatus with current limiting
US7800567B2 (en) 2006-03-20 2010-09-21 Stanley Electric Co., Ltd. LED drive circuit
JP2010225891A (en) * 2009-03-24 2010-10-07 Rohm Co Ltd Semiconductor device and electronic apparatus with the same
JP2010241347A (en) * 2009-04-08 2010-10-28 Koito Mfg Co Ltd Lighting fixture for vehicle
WO2010131889A2 (en) * 2009-05-11 2010-11-18 전자부품연구원 Light-emitting diode driving circuit and driving method
JP2010541012A (en) * 2007-10-05 2010-12-24 ケンブリッジ ディスプレイ テクノロジー リミテッド Dynamic adaptation of power supply voltage for current driven EL display
KR101029359B1 (en) 2004-08-05 2011-04-13 리니어 테크놀러지 코포레이션 Circuitry and methodology for driving multiple light emitting devices
WO2011052834A1 (en) * 2009-10-26 2011-05-05 (주)에어텍시스템 Constant-current-drive led module device
JP2011515027A (en) * 2008-03-12 2011-05-12 フリースケール セミコンダクター インコーポレイテッド LED driver with dynamic power management
KR101047027B1 (en) * 2009-10-26 2011-07-06 주식회사 에어텍시스템 Constant Current Driving Unidirectional LED Module Device
KR101047800B1 (en) * 2009-05-08 2011-07-07 엘지이노텍 주식회사 Power Supply for Light Emitting Diode
JP2011145928A (en) * 2010-01-15 2011-07-28 Sharp Corp Power source control system
JP4753885B2 (en) * 2004-02-11 2011-08-24 バガット、ピーター Lighting control apparatus and related control method
JP2011171230A (en) * 2010-02-22 2011-09-01 Panasonic Electric Works Co Ltd Led lighting circuit
KR101068075B1 (en) 2011-06-30 2011-09-28 (주)블루싸이언스 Current control apparatus for leds
JP2011199024A (en) * 2010-03-19 2011-10-06 Toshiba Lighting & Technology Corp Led lighting device
JP2012059839A (en) * 2010-09-07 2012-03-22 Rohm Co Ltd Drive circuit of light emitting element, light emitting device using the same, and electronic device
US8258706B2 (en) 2008-10-09 2012-09-04 Sharp Kabushiki Kaisha LED drive circuit, LED illumination component, LED illumination device, and LED illumination system
JP2013016518A (en) * 2005-11-18 2013-01-24 Cree Inc Solid state lighting panels with variable voltage boost current sources
US8400079B2 (en) 2010-02-05 2013-03-19 Sharp Kabushiki Kaisha LED drive circuit, dimming device, LED illumination fixture, LED illumination device, and LED illumination system
US8432103B2 (en) 2009-10-26 2013-04-30 Sharp Kabushiki Kaisha LED drive circuit, LED illumination fixture, LED illumination device, and LED illumination system
WO2013085158A1 (en) * 2011-12-05 2013-06-13 (주)알에프세미 Alternating current direct-coupled type light-emitting diode lighting apparatus
US8519680B2 (en) 2003-07-07 2013-08-27 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
US8698420B2 (en) 2009-03-06 2014-04-15 Sharp Kabushiki Kaisha LED drive circuit, LED lamp, LED lighting appliance, and LED lighting system
JP2014086689A (en) * 2012-10-26 2014-05-12 Rohm Co Ltd Control circuit for light-emitting device, light-emitting device using the same, and electronic apparatus
US8742681B2 (en) 2009-11-09 2014-06-03 Toshiba Lighting & Technology Corporation LED lighting device, illuminating device and power supply therefore having a normally-on type switching element
CN103889132A (en) * 2014-04-17 2014-06-25 南宁桂格精工科技有限公司 Constant flow source circuit of automobile headlamp
JP2014142350A (en) * 2008-05-23 2014-08-07 Fisher Controls International Llc Optical isolator multi-voltage detection circuit
CN104080247A (en) * 2009-11-09 2014-10-01 东芝照明技术株式会社 Integrated circuit, power supply device and illuminating device
US8941331B2 (en) 2005-11-18 2015-01-27 Cree, Inc. Solid state lighting panels with variable voltage boost current sources
JP2016100164A (en) * 2014-11-20 2016-05-30 パナソニックＩｐマネジメント株式会社 Lighting device and illumination equipment using the same
CN106160434A (en) * 2016-07-22 2016-11-23 矽力杰半导体技术(杭州)有限公司 Ripple Suppression method, circuit and apply its load driving circuits
CN109377938A (en) * 2018-11-16 2019-02-22 上海得倍电子技术有限公司 A kind of constant-current control device of LED display
US10734896B2 (en) 2003-07-07 2020-08-04 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
AT17755U1 (en) * 2017-06-22 2023-01-15 Tridonic Gmbh & Co Kg Single stage converter circuit arrangement with linear regulator

Cited By (123)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003215534A (en) * 2002-01-23 2003-07-30 Seiko Epson Corp Backlight control device for liquid crystal display
WO2003096436A1 (en) * 2002-05-07 2003-11-20 Rohm Co., Ltd. Light emitting element drive device and electronic device having light emitting element
US6822403B2 (en) 2002-05-07 2004-11-23 Rohm Co., Ltd. Light emitting element drive device and electronic device having light emitting element
US6989635B2 (en) 2002-10-01 2006-01-24 Koito Manufacturing Co., Ltd. Vehicular lamp with current limiting circuit
DE10346695B4 (en) * 2002-10-08 2008-08-07 Koito Manufacturing Co., Ltd. vehicle light
US6847169B2 (en) 2002-10-08 2005-01-25 Koito Manufacturing Co., Ltd. Lighting circuit
US6867557B2 (en) 2002-10-08 2005-03-15 Koito Manufacturing Co., Ltd. Lighting circuit
US6873111B2 (en) 2002-10-08 2005-03-29 Koito Manufacturing Co., Ltd. Vehicular lamp
FR2845328A1 (en) * 2002-10-08 2004-04-09 Koito Mfg Co Ltd Multi-function lamp for motor vehicles, uses switch-mode control of transistor supplying light source to determine light output to suit particular motor vehicle lamp application
DE10347743B4 (en) * 2002-10-15 2010-05-27 Koito Manufacturing Co., Ltd. lighting circuit
US7081708B2 (en) 2002-10-15 2006-07-25 Koito Manufacturing Co., Ltd. Lighting circuit
US6876153B2 (en) 2002-10-15 2005-04-05 Koito Manufacturing Co., Ltd. Switching regulator circuit and vehicular lamp
US6930472B2 (en) 2002-10-15 2005-08-16 Koito Manufacturing Co., Ltd. Switching regulator circuit
US7322718B2 (en) 2003-01-27 2008-01-29 Matsushita Electric Industrial Co., Ltd. Multichip LED lighting device
US7034607B2 (en) 2003-04-28 2006-04-25 Toko Kabushiki Kaisha Switching constant-current power device
JP2005010779A (en) * 2003-06-20 2005-01-13 Samsung Electronics Co Ltd High-efficiency power supply apparatus for display panel driving system and designing method thereof
US7106037B2 (en) 2003-07-02 2006-09-12 Toko, Inc. Switching-type constant current power supply device
JP2005027432A (en) * 2003-07-02 2005-01-27 Toko Inc Switching constant current power supply unit
US7944189B2 (en) 2003-07-07 2011-05-17 Rohm Co., Ltd. Load driving device and portable apparatus utilizing such driving device
US11487310B2 (en) 2003-07-07 2022-11-01 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
US8836295B2 (en) 2003-07-07 2014-09-16 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
US9526138B2 (en) 2003-07-07 2016-12-20 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
US10103625B2 (en) 2003-07-07 2018-10-16 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
US8242756B2 (en) 2003-07-07 2012-08-14 Rohm Co., Ltd. Load driving device and portable apparatus utilizing such driving device
US8519680B2 (en) 2003-07-07 2013-08-27 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
US9960677B2 (en) 2003-07-07 2018-05-01 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
US10734896B2 (en) 2003-07-07 2020-08-04 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
US10396659B2 (en) 2003-07-07 2019-08-27 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
US7541785B2 (en) 2003-07-07 2009-06-02 Rohm Co., Ltd. Load driving device and portable apparatus utilizing such driving device
US9526139B2 (en) 2003-07-07 2016-12-20 Rohm Co., Ltd. Load driving device, and lighting apparatus and liquid crystal display device using the same
JP2005073352A (en) * 2003-08-22 2005-03-17 Toko Inc Switching-type constant current power supply
US7388560B2 (en) 2003-08-29 2008-06-17 Rohm Co., Ltd. Power supply apparatus
JP2005136157A (en) * 2003-10-30 2005-05-26 Rohm Co Ltd Light emitting element driving device, display module having same driving device, and electronic device having same module
JP4753885B2 (en) * 2004-02-11 2011-08-24 バガット、ピーター Lighting control apparatus and related control method
KR101029359B1 (en) 2004-08-05 2011-04-13 리니어 테크놀러지 코포레이션 Circuitry and methodology for driving multiple light emitting devices
US7952335B2 (en) 2004-08-09 2011-05-31 St-Ericsson Sa Power converter and method for power conversion
JP2008509649A (en) * 2004-08-09 2008-03-27 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Power converter, integrated circuit including power converter, device including power converter, and power conversion method
EP1788695A1 (en) * 2004-08-17 2007-05-23 Rohm Co., Ltd. Power supply apparatus
JPWO2006018923A1 (en) * 2004-08-17 2008-05-01 ローム株式会社 Power supply
EP1788695A4 (en) * 2004-08-17 2010-01-27 Rohm Co Ltd Power supply apparatus
WO2006018923A1 (en) * 2004-08-17 2006-02-23 Rohm Co., Ltd Power supply apparatus
JP4510022B2 (en) * 2004-08-17 2010-07-21 ローム株式会社 Power supply device and electronic device using the same
US7301284B2 (en) 2004-09-17 2007-11-27 Koito Manufacturing Co., Ltd. Lighting control circuit for vehicle lighting equipment
US7948299B2 (en) 2004-12-03 2011-05-24 Rohm Co., Ltd. Power supply apparatus
WO2006059500A1 (en) * 2004-12-03 2006-06-08 Rohm Co., Ltd Power supply device, light emitting device using such power supply device, and electronic device
US7521912B2 (en) 2004-12-03 2009-04-21 Rohm Co., Ltd. Power supply apparatus
JP2006185942A (en) * 2004-12-24 2006-07-13 Toshiba Matsushita Display Technology Co Ltd Surface light source controller
JP2006228529A (en) * 2005-02-16 2006-08-31 Matsushita Electric Works Ltd Illumination apparatus
US7898188B2 (en) 2005-03-18 2011-03-01 Austriamicrosystems Ag Arrangement provided with a voltage converter for supplying voltage to an electrical charge and associated method
JP4777413B2 (en) * 2005-03-18 2011-09-21 オーストリアマイクロシステムス アーゲー Voltage converter apparatus and method for supplying voltage to electrical load
JP2008533966A (en) * 2005-03-18 2008-08-21 オーストリアマイクロシステムス アーゲー Voltage converter apparatus and method for supplying voltage to electrical load
JP4777412B2 (en) * 2005-03-18 2011-09-21 オーストリアマイクロシステムス アーゲー Voltage converter apparatus and method for supplying voltage to electrical load
JP2008533967A (en) * 2005-03-18 2008-08-21 オーストリアマイクロシステムス アーゲー Voltage converter apparatus and method for supplying voltage to electrical load
JP2006301027A (en) * 2005-04-15 2006-11-02 Avix Inc Color sequential led driving circuit
JP2006303214A (en) * 2005-04-21 2006-11-02 Sony Corp Led drive
JP2007005014A (en) * 2005-06-21 2007-01-11 Toshiba Matsushita Display Technology Co Ltd Illumination device and liquid crystal display device
JP2007082347A (en) * 2005-09-15 2007-03-29 Ricoh Co Ltd Anomalous connection detection circuit and driving device equipped with anomalous connection detection circuit
JP4731257B2 (en) * 2005-09-15 2011-07-20 株式会社リコー Abnormal connection detection circuit and drive device provided with abnormal connection detection circuit
JP4663606B2 (en) * 2005-09-16 2011-04-06 三星電子株式会社 Display device
JP2007086778A (en) * 2005-09-16 2007-04-05 Samsung Electronics Co Ltd Display device
JP2007095907A (en) * 2005-09-28 2007-04-12 Ricoh Co Ltd Driving circuit and electronic apparatus using the same
JP2007129862A (en) * 2005-11-07 2007-05-24 Rohm Co Ltd Power supply unit
US8941331B2 (en) 2005-11-18 2015-01-27 Cree, Inc. Solid state lighting panels with variable voltage boost current sources
JP2013016518A (en) * 2005-11-18 2013-01-24 Cree Inc Solid state lighting panels with variable voltage boost current sources
JP2007236095A (en) * 2006-02-28 2007-09-13 Ccs Inc Power supply for led and light irradiation apparatus
US7800567B2 (en) 2006-03-20 2010-09-21 Stanley Electric Co., Ltd. LED drive circuit
JP2007318983A (en) * 2006-05-24 2007-12-06 Power Integrations Inc Method and arrangement for supplying power to light emitting diode array
JP2007328535A (en) * 2006-06-07 2007-12-20 Rohm Co Ltd Power supply device, and electronic device using the same
JP2006345691A (en) * 2006-07-31 2006-12-21 Ricoh Co Ltd Charge pumping circuit
JP4718389B2 (en) * 2006-07-31 2011-07-06 株式会社リコー Semiconductor device
JP2006320194A (en) * 2006-07-31 2006-11-24 Ricoh Co Ltd Power-supply circuit
US7741788B2 (en) 2007-02-22 2010-06-22 Koito Manufacturing Co., Ltd. Light emitting apparatus with current limiting
JP2008295009A (en) * 2007-05-22 2008-12-04 Renyo Handotai Kofun Yugenkoshi Constant current driving circuit
US7961158B2 (en) 2007-05-22 2011-06-14 Ite Tech. Inc. Constant-current driving circuit
JP4577525B2 (en) * 2007-05-31 2010-11-10 東芝ライテック株式会社 Lighting device
JP2008300208A (en) * 2007-05-31 2008-12-11 Toshiba Lighting & Technology Corp Luminaire
JP2009004788A (en) * 2007-06-21 2009-01-08 Dongbu Hitek Co Ltd Light emitting diode driving circuit
JP2009016280A (en) * 2007-07-06 2009-01-22 Nec Lcd Technologies Ltd Light emission control circuit, light emission control method, surface lighting apparatus, and liquid crystal display device with the surface lighting apparatus
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
JP2010541012A (en) * 2007-10-05 2010-12-24 ケンブリッジ ディスプレイ テクノロジー リミテッド Dynamic adaptation of power supply voltage for current driven EL display
KR100935055B1 (en) 2007-12-10 2009-12-31 산켄덴키 가부시키가이샤 Light emitting device driving device and electronic device using the device
JP2011515027A (en) * 2008-03-12 2011-05-12 フリースケール セミコンダクター インコーポレイテッド LED driver with dynamic power management
JP4647674B2 (en) * 2008-04-17 2011-03-09 株式会社小糸製作所 Lighting circuit
JP2008192625A (en) * 2008-04-17 2008-08-21 Koito Mfg Co Ltd Lighting circuit
JP2014142350A (en) * 2008-05-23 2014-08-07 Fisher Controls International Llc Optical isolator multi-voltage detection circuit
JP2009290183A (en) * 2008-05-30 2009-12-10 Green Solution Technology Inc Light emitting diode driving circuit and controller thereof
TWI400989B (en) * 2008-05-30 2013-07-01 Green Solution Technology Inc Light emitting diode driving circuit and controller thereof
JP2010055843A (en) * 2008-08-26 2010-03-11 Panasonic Electric Works Co Ltd Illumination lighting device, lighting system and luminaire
JP2010086826A (en) * 2008-09-30 2010-04-15 Kyocera Corp Light source device and display
US8258706B2 (en) 2008-10-09 2012-09-04 Sharp Kabushiki Kaisha LED drive circuit, LED illumination component, LED illumination device, and LED illumination system
US8810135B2 (en) 2008-10-09 2014-08-19 Sharp Kabushiki Kaisha LED drive circuit, LED illumination component, LED illumination device, and LED illumination system
JP2010119200A (en) * 2008-11-12 2010-05-27 Yamatake Corp Current output circuit
US8698420B2 (en) 2009-03-06 2014-04-15 Sharp Kabushiki Kaisha LED drive circuit, LED lamp, LED lighting appliance, and LED lighting system
JP2010225891A (en) * 2009-03-24 2010-10-07 Rohm Co Ltd Semiconductor device and electronic apparatus with the same
JP2010241347A (en) * 2009-04-08 2010-10-28 Koito Mfg Co Ltd Lighting fixture for vehicle
KR101047800B1 (en) * 2009-05-08 2011-07-07 엘지이노텍 주식회사 Power Supply for Light Emitting Diode
WO2010131889A2 (en) * 2009-05-11 2010-11-18 전자부품연구원 Light-emitting diode driving circuit and driving method
WO2010131889A3 (en) * 2009-05-11 2011-01-27 전자부품연구원 Light-emitting diode driving circuit and driving method
KR101028587B1 (en) 2009-05-11 2011-04-12 전자부품연구원 Circuit and method for driving Light Emitting DiodeLED
KR101047027B1 (en) * 2009-10-26 2011-07-06 주식회사 에어텍시스템 Constant Current Driving Unidirectional LED Module Device
US8872434B2 (en) 2009-10-26 2014-10-28 Airtec System Co., Ltd. Constant-current-drive LED module device
US8432103B2 (en) 2009-10-26 2013-04-30 Sharp Kabushiki Kaisha LED drive circuit, LED illumination fixture, LED illumination device, and LED illumination system
WO2011052834A1 (en) * 2009-10-26 2011-05-05 (주)에어텍시스템 Constant-current-drive led module device
US9392655B2 (en) 2009-11-09 2016-07-12 Toshiba Lighting & Technology Corporation LED lighting device and illuminating device
US8742681B2 (en) 2009-11-09 2014-06-03 Toshiba Lighting & Technology Corporation LED lighting device, illuminating device and power supply therefore having a normally-on type switching element
US9155143B2 (en) 2009-11-09 2015-10-06 Toshiba Lighting & Technology Corporation LED lighting device and illuminating device
CN104080247A (en) * 2009-11-09 2014-10-01 东芝照明技术株式会社 Integrated circuit, power supply device and illuminating device
JP2011145928A (en) * 2010-01-15 2011-07-28 Sharp Corp Power source control system
US8400079B2 (en) 2010-02-05 2013-03-19 Sharp Kabushiki Kaisha LED drive circuit, dimming device, LED illumination fixture, LED illumination device, and LED illumination system
JP2011171230A (en) * 2010-02-22 2011-09-01 Panasonic Electric Works Co Ltd Led lighting circuit
JP2011199024A (en) * 2010-03-19 2011-10-06 Toshiba Lighting & Technology Corp Led lighting device
JP2012059839A (en) * 2010-09-07 2012-03-22 Rohm Co Ltd Drive circuit of light emitting element, light emitting device using the same, and electronic device
KR101068075B1 (en) 2011-06-30 2011-09-28 (주)블루싸이언스 Current control apparatus for leds
WO2013085158A1 (en) * 2011-12-05 2013-06-13 (주)알에프세미 Alternating current direct-coupled type light-emitting diode lighting apparatus
JP2014086689A (en) * 2012-10-26 2014-05-12 Rohm Co Ltd Control circuit for light-emitting device, light-emitting device using the same, and electronic apparatus
CN103889132A (en) * 2014-04-17 2014-06-25 南宁桂格精工科技有限公司 Constant flow source circuit of automobile headlamp
JP2016100164A (en) * 2014-11-20 2016-05-30 パナソニックＩｐマネジメント株式会社 Lighting device and illumination equipment using the same
CN105636260A (en) * 2014-11-20 2016-06-01 松下知识产权经营株式会社 Lighting device and lighting fixture using same
CN106160434B (en) * 2016-07-22 2020-05-15 矽力杰半导体技术(杭州)有限公司 Ripple wave suppression method and circuit and load driving circuit applying same
CN106160434A (en) * 2016-07-22 2016-11-23 矽力杰半导体技术(杭州)有限公司 Ripple Suppression method, circuit and apply its load driving circuits
AT17755U1 (en) * 2017-06-22 2023-01-15 Tridonic Gmbh & Co Kg Single stage converter circuit arrangement with linear regulator
CN109377938A (en) * 2018-11-16 2019-02-22 上海得倍电子技术有限公司 A kind of constant-current control device of LED display
CN109377938B (en) * 2018-11-16 2023-08-08 上海得倍电子技术有限公司 Constant current control device of LED display screen

Similar Documents

Publication Publication Date Title
JP2001215913A (en) Lighting circuit
JP4950631B2 (en) Method and apparatus for supplying power to a light emitting diode array
JP5239138B2 (en) LED lighting device
US7646153B2 (en) Switching regulator
KR101315078B1 (en) Led lighting device
US7235954B2 (en) Load driving device and portable apparatus utilizing such driving device
JP4945918B2 (en) LED drive device
JP4199202B2 (en) Power supply device and lighting device
US8742689B2 (en) Light emitting diode driving apparatus
US7652462B2 (en) Constant current regulator with current sensing circuit loop
JP2002203988A (en) Light emitting element driving circuit
JP2005033853A (en) Loading driver and portable apparatus
JP2003100472A (en) Driving equipment for light emitting diode
JP5962017B2 (en) Light emitting element driving device
JP2006237519A (en) Drive circuit and current controlling method
US20060152875A1 (en) Overcurrent protection device
JP3739768B2 (en) Load drive device and portable device
JP2002064223A (en) Drive circuit of semiconductor light-emitting diode
JP2002369507A (en) Switching power unit
JP4800648B2 (en) Constant current drive circuit
JPH05129665A (en) Led drive circuit
JP6256830B2 (en) Lighting device
JP2002369506A (en) Current drive circuit
JP6436226B2 (en) Light emitting load driving device and light emitting device
JPS646552Y2 (en)

Legal Events

Date Code Title Description
A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20050802

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20050930

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20060214