JP3469508B2 - Light emitting diode lighting circuit - Google Patents
Light emitting diode lighting circuitInfo
- Publication number
- JP3469508B2 JP3469508B2 JP21372699A JP21372699A JP3469508B2 JP 3469508 B2 JP3469508 B2 JP 3469508B2 JP 21372699 A JP21372699 A JP 21372699A JP 21372699 A JP21372699 A JP 21372699A JP 3469508 B2 JP3469508 B2 JP 3469508B2
- Authority
- JP
- Japan
- Prior art keywords
- light emitting
- emitting diode
- circuit
- voltage
- resistor
- 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.)
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- Circuit Arrangement For Electric Light Sources In General (AREA)
- Dc-Dc Converters (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、表示、照明に用い
られる発光ダイオードを高効率で点灯させるための技術
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for lighting a light emitting diode used for display and illumination with high efficiency.
【０００２】[0002]
【従来の技術】発光ダイオードは、電子機器の動作状態
を示すための表示ランプ、あるいは表示パネルの照明な
どに広く使用されている。発光ダイオードを点灯するに
は、従来、発光ダイオードと抵抗を直列に接続し、この
直列回路に電源から直接、電力を供給するという方法が
良く用いられていた。従来から広く使用されている赤色
系の発光ダイオードは、その順方向電圧が１．５Ｖ程度
である。このため、出力電圧が比較的低い電源でも、発
光ダイオードと抵抗の直列回路に電力を供給し、点灯す
ることが可能であった。2. Description of the Related Art A light emitting diode is widely used as a display lamp for indicating an operating state of electronic equipment or as an illumination of a display panel. In order to light the light emitting diode, conventionally, a method in which a light emitting diode and a resistor are connected in series and power is directly supplied from a power source to this series circuit has been often used. A red light emitting diode which has been widely used from the past has a forward voltage of about 1.5V. Therefore, even with a power source having a relatively low output voltage, it was possible to supply power to the series circuit of the light emitting diode and the resistor to illuminate.
【０００３】[0003]
【発明が解決しようとする課題】しかし、近年出現した
青色系および白色系の発光ダイオードは、従来のものよ
りも順方向電圧が高く、その値は３．５Ｖ以上である。
このため、青色系、白色系の発光ダイオードは、従来の
ように抵抗と直列に接続し、その直列回路に出力電圧の
低い電源から電力を供給して点灯することは難しくなっ
ている。そこで本発明は、発光ダイオードの順方向電圧
よりも出力電圧の低い電源を使用した場合でも、発光ダ
イオードを高効率かつ安定して点灯させようとするもの
である。However, the blue-based and white-based light-emitting diodes that have appeared in recent years have higher forward voltages than the conventional ones, and their values are 3.5 V or more.
For this reason, it is difficult to connect the blue-based and white-based light-emitting diodes in series with a resistor as in the conventional case, and to supply power to the series circuit from a power source with a low output voltage to illuminate it. Therefore, the present invention is intended to illuminate a light emitting diode with high efficiency and stability even when a power source whose output voltage is lower than the forward voltage of the light emitting diode is used.
【０００４】[0004]
【課題を解決するための手段】上記課題を解決するため
の本発明による発光ダイオード点灯回路は、直流入力と
グランドとの間にチョークコイルとスイッチング素子を
直列に接続し、チョークコイルとスイッチング素子との
接続点に発光ダイオード装置のアノード端子を接続し、
発光ダイオード装置のカソード端子をコンデンサと抵抗
の並列回路を介してグランドに接続する。あるいは、直
流入力とグランドとの間にトランスの１次コイルとスイ
ッチング素子を直列に接続し、トランスの２次コイルの
一端をグランドに接続し、２次コイルの他端を発光ダイ
オード装置のアノード端子に接続し、発光ダイオード装
置のカソード端子をコンデンサと抵抗の並列回路を介し
てグランドに接続する。ここで、発光ダイオード装置
は、１あるいはその順方向を統一して直列接続された２
以上の発光ダイオード素子を有し、抵抗の電圧を一定に
制御するフィードバック制御が行われることで当該発光
ダイオード装置の平均電流が一定に制御されることを特
徴とする。A light emitting diode lighting circuit according to the present invention for solving the above-mentioned problems includes a choke coil and a switching element connected in series between a DC input and a ground, and a choke coil and a switching element. Connect the anode terminal of the light emitting diode device to the connection point of
The cathode terminal of the light emitting diode device is connected to the ground through a parallel circuit of a capacitor and a resistor . Alternatively, the primary coil of the transformer and the switching element are connected in series between the DC input and the ground, one end of the secondary coil of the transformer is connected to the ground, and the other end of the secondary coil is the anode terminal of the light emitting diode device. The cathode terminal of the light emitting diode device is connected to the ground via a parallel circuit of a capacitor and a resistor . Here, the light emitting diode devices are connected in series in one or in the same forward direction.
It is characterized in that it has the above-mentioned light emitting diode element, and the average current of the light emitting diode device is controlled to be constant by performing feedback control for controlling the voltage of the resistance to be constant.
【０００５】[0005]
【発明の実施の形態】直流入力とグランドとの間にチョ
ークコイルとスイッチング素子を直列に接続する。その
チョークコイルとスイッチング素子の接続点から、少な
くとも一つの発光ダイオード素子からなる発光ダイオー
ドを介して、当該発光ダイオードのカソードに接続され
た負荷抵抗とコンデンサの並列回路に電流を供給する回
路構成とする。あるいは直流入力とグランドとの間にト
ランスの１次コイルとスイッチング素子を直列に接続す
る。そのトランスの２次コイルの他端から発光ダイオー
ドを介して発光ダイオードのカソードに接続された負荷
抵抗とコンデンサの並列回路に電流を供給する回路構成
とする。DETAILED DESCRIPTION OF THE INVENTION A choke coil and a switching element are connected in series between a DC input and a ground. From the connection point of the choke coil and the switching element, through a light emitting diode composed of at least one light emitting diode element, a circuit configuration is configured to supply a current to a parallel circuit of a load resistor and a capacitor connected to the cathode of the light emitting diode. . Alternatively, the primary coil of the transformer and the switching element are connected in series between the DC input and the ground. The circuit configuration is such that current is supplied from the other end of the secondary coil of the transformer to a parallel circuit of a load resistor and a capacitor connected to the cathode of the light emitting diode via the light emitting diode.
【０００６】そして、負荷抵抗の端子間電圧を一定にす
るフィードバック制御を行うことにより発光ダイオード
の平均電流を一定に制御し、その発光を安定して行わせ
る。ここで負荷抵抗の電圧は、損失を増加させないよう
にするため、発光ダイオードの順方向電圧より低くなる
ように設定する。Then, the average current of the light emitting diode is controlled to be constant by performing the feedback control to make the voltage between the terminals of the load resistor constant, and the light emission is stably performed. Here, the voltage of the load resistor is set to be lower than the forward voltage of the light emitting diode so as not to increase the loss.
【０００７】[0007]
【実施例】発光ダイオードを高効率かつ安定して点灯さ
せることを可能とする、本発明による発光ダイオード点
灯回路の第１の実施例を図１に示した。図１において、
Ｅは外部電源、１は発光ダイオード点灯回路の入力端子
を示している。入力端子１とグランドとの間にはチョー
クコイル２とスイッチング素子３が直列に接続され、ス
イッチング素子３の制御端子には制御回路４が接続され
る。チョークコイル２とスイッチング素子３の接続点に
発光ダイオード５のアノードが接続され、発光ダイオー
ド５のカソードはコンデンサ７と抵抗６の並列回路を介
してグランドに接続されている。抵抗６の発光ダイオー
ド側の一端は制御回路４に接続され、フィードバック制
御が行われるようになされている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a light emitting diode lighting circuit according to the present invention which enables a light emitting diode to be lit with high efficiency and stability is shown in FIG. In FIG.
E is an external power source, and 1 is an input terminal of the light emitting diode lighting circuit. The choke coil 2 and the switching element 3 are connected in series between the input terminal 1 and the ground, and the control circuit 4 is connected to the control terminal of the switching element 3. The anode of the light emitting diode 5 is connected to the connection point between the choke coil 2 and the switching element 3, and the cathode of the light emitting diode 5 is connected to the ground via the parallel circuit of the capacitor 7 and the resistor 6. One end of the resistor 6 on the light emitting diode side is connected to the control circuit 4 so that feedback control is performed.
【０００８】図１に示す回路において、スイッチング素
子３が周期的なオン、オフ動作を行うと、スイッチング
素子がオフ状態の時、チョークコイル２とスイッチング
素子３の接続点にはチョークコイル２の逆起電力によ
り、電源Ｅから入力端子１に供給される入力電圧よりも
高い電圧が現れる。すると、チョークコイル２とスイッ
チング素子３の接続点から発光ダイオード５を通してコ
ンデンサ７と抵抗６の並列回路に電流が流れる。この
時、発光ダイオード５の端子間に順方向電圧が発生し、
発光ダイオード５が発光、点灯することになる。In the circuit shown in FIG. 1, when the switching element 3 is periodically turned on and off, when the switching element is in an off state, the choke coil 2 and the switching element 3 are connected to each other at a connection point opposite to the choke coil 2. Due to the electromotive force, a voltage higher than the input voltage supplied from the power source E to the input terminal 1 appears. Then, a current flows from the connection point between the choke coil 2 and the switching element 3 to the parallel circuit of the capacitor 7 and the resistor 6 through the light emitting diode 5. At this time, a forward voltage is generated between the terminals of the light emitting diode 5,
The light emitting diode 5 emits light and lights up.
【０００９】ここで、図１の回路はチョークコイル２の
逆起電力であるフライバック電圧を用いるので、コンデ
ンサ７と抵抗６の並列回路の両端に現れる電圧と発光ダ
イオード５の順方向電圧の和は入力電圧より高いという
条件が必要となる。例えば、外部電源Ｅがリチウム電池
で入力電圧が２．７〜４．２Ｖであるとする。これに対
し、発光ダイオード素子を１個用いた発光ダイオード５
の順方向電圧が３．５Ｖであるならば、実際に点灯回路
を構成した場合には、コンデンサ７と抵抗６の並列回路
の端子間電圧は０．７Ｖ以上に設定する必要がある。な
お、発光ダイオード素子を２個以上用いた時には並列回
路の端子間電圧を０．７Ｖ以上にするという制約は無く
なり、微小電圧でも良い。Since the circuit of FIG. 1 uses the flyback voltage which is the back electromotive force of the choke coil 2, the sum of the voltage appearing across the parallel circuit of the capacitor 7 and the resistor 6 and the forward voltage of the light emitting diode 5. Must be higher than the input voltage. For example, assume that the external power source E is a lithium battery and the input voltage is 2.7 to 4.2V. On the other hand, a light emitting diode 5 using one light emitting diode element
If the forward voltage is 3.5 V, the terminal voltage of the parallel circuit of the capacitor 7 and the resistor 6 must be set to 0.7 V or higher when the lighting circuit is actually configured. When two or more light emitting diode elements are used, there is no restriction that the inter-terminal voltage of the parallel circuit be 0.7 V or more, and a minute voltage may be used.
【００１０】ところで、順方向電圧の高い発光ダイオー
ドを供給電圧の低い電源で駆動しようとする場合、図４
に示すように昇圧回路を介して発光ダイオードを点灯す
ることも考えられる。しかしこの場合、昇圧回路を構成
する整流ダイオードの順方向電圧は無用な損失を増加さ
せる原因となる。ところが、図１のような回路にて発光
ダイオード５を点灯すると、本来、整流ダイオードで発
生する無用な損失が発光のために利用され、発光対入力
電力の効率が向上する利点がある。By the way, when a light-emitting diode having a high forward voltage is to be driven by a power source having a low supply voltage, FIG.
It is also possible to turn on the light emitting diode via a booster circuit as shown in FIG. However, in this case, the forward voltage of the rectifying diode that constitutes the booster circuit causes unnecessary loss to increase. However, when the light emitting diode 5 is turned on in the circuit as shown in FIG. 1, there is an advantage that the useless loss originally generated in the rectifying diode is utilized for light emission, and the efficiency of light emission versus input power is improved.
【００１１】また、図１の回路では、抵抗６の端子間電
圧を一定にするためのパルス幅制御が制御回路４で行わ
れる。すると抵抗６で消費される電流、即ち発光ダイオ
ード５を通して流れる電流は一定となり、発光ダイオー
ド５の発光量が入力電圧に依存しないようにできるとい
った利点もある。なお、図１の回路において抵抗６は、
発光ダイオード５の電流を検出して一定にするという、
電流検出機能を有している。図２は図１の回路を流れる
電流の波形図であり、図１の回路が電流を一定に制御し
ている様子を示している。In the circuit of FIG. 1, the control circuit 4 controls the pulse width for keeping the voltage across the terminals of the resistor 6 constant. Then, the current consumed by the resistor 6, that is, the current flowing through the light emitting diode 5 becomes constant, and there is an advantage that the light emission amount of the light emitting diode 5 can be made independent of the input voltage. The resistor 6 in the circuit of FIG.
The current of the light emitting diode 5 is detected and made constant,
It has a current detection function. FIG. 2 is a waveform diagram of the current flowing through the circuit of FIG. 1, and shows how the circuit of FIG. 1 controls the current to be constant.
【００１２】図２の上段の電流波形ａ）は、外部電源Ｅ
から供給される入力電圧が比較的高い時にスイッチング
素子３を流れる電流（点線）と発光ダイオード５を流れ
る電流（実線）を示している。一方、下段の電流波形
ｂ）は入力電圧が比較的低いときの同じ電流を示してい
る。抵抗６を流れる電流は全て発光ダイオード５を経由
するため、斜線部の平均値であるＩａｖとなる。抵抗６
の端子間電圧は制御回路４により一定に制御されるため
抵抗６を流れる電流も一定に制御される。このため、電
流波形が入力電圧によって変化しようとも、発光ダイオ
ード５を流れる電流の平均値は同一のＩａｖとなる。こ
れは、発光ダイオード５の発光量が平均電流が一定とい
う範囲で一定となるということを示している。The current waveform a) in the upper part of FIG.
The current flowing through the switching element 3 (dotted line) and the current flowing through the light emitting diode 5 (solid line) are shown when the input voltage supplied from is relatively high. On the other hand, the lower current waveform b) shows the same current when the input voltage is relatively low. Since all the current flowing through the resistor 6 passes through the light emitting diode 5, the average value of the shaded portion is Iav. Resistance 6
Since the inter-terminal voltage of is controlled to be constant by the control circuit 4, the current flowing through the resistor 6 is also controlled to be constant. Therefore, even if the current waveform changes depending on the input voltage, the average value of the current flowing through the light emitting diode 5 is the same Iav. This indicates that the light emission amount of the light emitting diode 5 is constant in the range where the average current is constant.
【００１３】なお、抵抗６の端子間に発生する電圧、即
ち、抵抗６の抵抗値と発光ダイオード５を流れる平均電
流の積を大きくとった方が図１の回路の構成では入力電
圧の範囲を広くすることが出来る。しかしこの電圧が高
いと、抵抗６における電力消費量が多くなり、点灯回路
全体の発光対入力電力の効率が低下する。この為、抵抗
６の端子間に発生する電圧は、発光ダイオードの順方向
電圧より充分低く設定されるよう点灯回路のフィードバ
ック制御を行うことが好ましい。In the circuit configuration of FIG. 1, the range of the input voltage is set to be larger by increasing the voltage generated between the terminals of the resistor 6, that is, the product of the resistance value of the resistor 6 and the average current flowing through the light emitting diode 5. Can be widened. However, when this voltage is high, the power consumption of the resistor 6 is increased, and the efficiency of light emission versus input power of the entire lighting circuit is reduced. Therefore, it is preferable to perform feedback control of the lighting circuit so that the voltage generated between the terminals of the resistor 6 is set sufficiently lower than the forward voltage of the light emitting diode.
【００１４】図３には本発明による発光ダイオード点灯
回路の第２の実施例を示した。図３に示す回路は図１の
回路のチョーク部をトランスで構成したものである。す
なわち、外部電源Ｅと接続される入力端子１とグランド
との間にトランス８の１次コイルとスイッチング素子３
が直列に接続され、スイッチング素子３の制御端子には
制御回路４が接続される。トランス８の２次コイルの一
端はグランドに接続され、他端は発光ダイオード５のア
ノードが接続される。発光ダイオード５のカソードはコ
ンデンサ７と抵抗６の並列回路を介してグランドに接続
され、抵抗６の発光ダイオード側の一端は制御回路４に
接続され、フィードバック制御が行われるようになされ
ている。FIG. 3 shows a second embodiment of the light emitting diode lighting circuit according to the present invention. The circuit shown in FIG. 3 is a circuit in which the choke portion of the circuit shown in FIG. 1 is composed of a transformer. That is, the primary coil of the transformer 8 and the switching element 3 are connected between the input terminal 1 connected to the external power source E and the ground.
Are connected in series, and the control circuit 4 is connected to the control terminal of the switching element 3. One end of the secondary coil of the transformer 8 is connected to the ground, and the other end thereof is connected to the anode of the light emitting diode 5. The cathode of the light emitting diode 5 is connected to the ground via the parallel circuit of the capacitor 7 and the resistor 6, and one end of the resistor 6 on the light emitting diode side is connected to the control circuit 4 so that feedback control is performed.
【００１５】この図３に示す回路各部の動作は、実質的
に図１に示す回路各部の動作と同じとなる。また、その
回路を流れる電流も利点も図１の回路と同じであり、そ
の説明は省略する。なお、図１の回路の場合、発光ダイ
オード５の順方向電圧、抵抗６とコンデンサ７の並列回
路の端子間電圧、入力電圧の三者間に一定の条件があっ
た。しかし図３の回路では、トランス８によって発光ダ
イオード５と入力端子１とが直流的に分離されるため、
この条件は無関係となる。このため、図３に示す回路
は、広い範囲の入力電圧に対して動作を行うことがで
き、その用途が拡大できる。入力条件に対しては図１の
回路よりも有利な構成例である。The operation of each part of the circuit shown in FIG. 3 is substantially the same as the operation of each part of the circuit shown in FIG. Further, the current flowing through the circuit and the advantage are the same as those of the circuit of FIG. 1, and the description thereof will be omitted. In the case of the circuit shown in FIG. 1, there are certain conditions among the forward voltage of the light emitting diode 5, the terminal voltage of the parallel circuit of the resistor 6 and the capacitor 7, and the input voltage. However, in the circuit of FIG. 3, since the transformer 8 separates the light emitting diode 5 and the input terminal 1 in terms of direct current,
This condition is irrelevant. Therefore, the circuit shown in FIG. 3 can operate for a wide range of input voltage, and its application can be expanded. This is a configuration example that is more advantageous than the circuit of FIG. 1 for input conditions.
【００１６】[0016]
【発明の効果】以上に説明したように本発明による発光
ダイオード点灯回路は、チョークコイルとスイッチング
素子の接続点、あるいは１次コイルにスイッチング素子
が接続されたトランスの２次コイルの他端から、発光ダ
イオードを介して、発光ダイオードのカソードに接続さ
れた抵抗とコンデンサの並列回路に電流を供給する回路
構成と、抵抗の両端の電圧を一定に制御することにより
発光ダイオードを流れる電流の平均値を一定に制御する
といった制御動作を特徴としている。このような本発明
によれば、順方向電圧が点灯回路入力電圧よりも高い場
合でも、発光ダイオードを効率良く、しかも入力電圧が
変動しても一定の電流で安定して点灯することができ
る。殊に、順方向電圧の高い青色系、白色系の発光ダイ
オードが、低い電圧の電源で点灯可能となる。As described above, in the light emitting diode lighting circuit according to the present invention, from the connection point between the choke coil and the switching element or the other end of the secondary coil of the transformer in which the switching element is connected to the primary coil, Through the light emitting diode, the circuit configuration that supplies the current to the parallel circuit of the resistor and the capacitor connected to the cathode of the light emitting diode, and the average value of the current flowing through the light emitting diode is controlled by controlling the voltage across the resistor constant. It features a control operation such as constant control. According to the present invention as described above, even when the forward voltage is higher than the lighting circuit input voltage, it is possible to efficiently light the light emitting diode and to stably light the light emitting diode with a constant current even when the input voltage changes. In particular, blue-based and white-based light-emitting diodes having a high forward voltage can be turned on by a low-voltage power supply.
【図１】 本発明による発光ダイオード点灯回路の第１
の実施例の回路図。FIG. 1 is a first circuit diagram of a light emitting diode lighting circuit according to the present invention.
2 is a circuit diagram of the embodiment.
【図２】 図１に示す回路を流れる電流の波形図。FIG. 2 is a waveform diagram of a current flowing through the circuit shown in FIG.
【図３】 本発明による発光ダイオード点灯回路の第２
の実施例の回路図。FIG. 3 is a second circuit diagram of a light emitting diode lighting circuit according to the present invention.
2 is a circuit diagram of the embodiment.
【図４】 一般的な昇圧回路を使用した場合の発光ダイ
オード点灯回路の例。FIG. 4 shows an example of a light emitting diode lighting circuit when a general booster circuit is used.
Ｅ：外部電源 １：入力端子 ２：チョークコ
イル ３：スイッチング素子 ４：制御回路
５：発光ダイオード ６：抵抗（負荷として
の） ７：コンデンサE: External power supply 1: Input terminal 2: Choke coil 3: Switching element 4: Control circuit
5: Light emitting diode 6: Resistor (as load) 7: Capacitor
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平11−68161（ＪＰ，Ａ) 特開 平８−79984（ＪＰ，Ａ) 特開 平６−133540（ＪＰ，Ａ) 特開 平４−320107（ＪＰ，Ａ) 特開 平11−67471（ＪＰ，Ａ) 特開 平９−74224（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H02M 3/155 H05B 37/02 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-11-68161 (JP, A) JP-A-8-79984 (JP, A) JP-A-6-133540 (JP, A) JP-A-4- 320107 (JP, A) JP 11-67471 (JP, A) JP 9-74224 (JP, A) (58) Fields investigated (Int.Cl. 7 , DB name) H02M 3/155 H05B 37 / 02
Claims (4)
イルとスイッチング素子を直列に接続し、該チョークコ
イルと該スイッチング素子との接続点に発光ダイオード
装置のアノード端子を接続し、該発光ダイオード装置の
カソード端子をコンデンサと抵抗の並列回路を介してグ
ランドに接続し、該抵抗の電圧を一定にするフィードバ
ック制御を行うことにより該発光ダイオード装置の平均
電流を一定に制御することを特徴とする発光ダイオード
点灯回路。1. A light emitting diode device, wherein a choke coil and a switching element are connected in series between a DC input and a ground, and an anode terminal of the light emitting diode device is connected to a connection point between the choke coil and the switching element. The cathode terminal of is connected to the ground via a parallel circuit of a capacitor and a resistor , and the voltage of the resistor is kept constant.
Control of the light emitting diode device by
A light-emitting diode lighting circuit, which is characterized by controlling a constant current .
１次コイルとスイッチング素子を直列に接続し、該トラ
ンスの２次コイルの一端をグランドに接続し、該２次コ
イルの他端を発光ダイオード装置のアノード端子に接続
し、該発光ダイオード装置のカソード端子をコンデンサ
と抵抗の並列回路を介してグランドに接続し、該抵抗の
電圧を一定にするフィードバック制御を行うことにより
該発光ダイオード装置の平均電流を一定に制御すること
を特徴とする発光ダイオード点灯回路。2. A primary coil of a transformer and a switching element are connected in series between a DC input and a ground, one end of a secondary coil of the transformer is connected to ground, and the other end of the secondary coil emits light. was connected to the anode terminal of the diode device, connect the cathode terminal of the light emitting diode device to the ground through a parallel circuit of a resistor and a capacitor, the said resistor
By performing feedback control to keep the voltage constant
A light emitting diode lighting circuit, wherein an average current of the light emitting diode device is controlled to be constant .
順方向電圧より低くなるように制御が行われることを特
徴とする、請求項１あるいは請求項２に記載した発光ダ
イオード点灯回路。 3. The voltage of said load is of a light emitting diode device.
The control is performed so that it is lower than the forward voltage.
The light emitting device according to claim 1 or 2,
Iodo lighting circuit.
は、その順方向を統一して直列接続された２以上の発光
ダイオード素子を有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発光ダイオード点灯回
路。 4. The number of the light emitting diode device is one or
Emits two or more lights that are connected in series by unifying their forward directions.
The device according to claim 1, further comprising a diode element.
4. A light emitting diode lighting time according to claim 3.
Road.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21372699A JP3469508B2 (en) | 1999-07-28 | 1999-07-28 | Light emitting diode lighting circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21372699A JP3469508B2 (en) | 1999-07-28 | 1999-07-28 | Light emitting diode lighting circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001045747A JP2001045747A (en) | 2001-02-16 |
| JP3469508B2 true JP3469508B2 (en) | 2003-11-25 |
Family
ID=16643991
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21372699A Expired - Fee Related JP3469508B2 (en) | 1999-07-28 | 1999-07-28 | Light emitting diode lighting circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3469508B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4177022B2 (en) * | 2002-05-07 | 2008-11-05 | ローム株式会社 | LIGHT EMITTING ELEMENT DRIVE DEVICE AND ELECTRONIC DEVICE HAVING LIGHT EMITTING ELEMENT |
| JP2004136719A (en) * | 2002-10-15 | 2004-05-13 | Koito Mfg Co Ltd | Lighting circuit |
| DE10356608B4 (en) * | 2002-12-03 | 2017-09-28 | Philips Lighting North America Corporation | Lighting arrangement and liquid crystal display |
| JP4001856B2 (en) * | 2003-10-30 | 2007-10-31 | ローム株式会社 | LIGHT EMITTING ELEMENT DRIVE DEVICE, DISPLAY MODULE HAVING LIGHT EMITTING ELEMENT DRIVE DEVICE, AND ELECTRONIC DEVICE HAVING DISPLAY MODULE |
| JP4170924B2 (en) * | 2004-01-23 | 2008-10-22 | 株式会社小糸製作所 | Vehicle lighting |
| JP4646110B2 (en) * | 2004-10-22 | 2011-03-09 | 株式会社中川研究所 | Power source and lighting device for semiconductor light emitting device |
-
1999
- 1999-07-28 JP JP21372699A patent/JP3469508B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2001045747A (en) | 2001-02-16 |
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