JPS6319902Y2 - - Google Patents
Info
- Publication number
- JPS6319902Y2 JPS6319902Y2 JP1981097500U JP9750081U JPS6319902Y2 JP S6319902 Y2 JPS6319902 Y2 JP S6319902Y2 JP 1981097500 U JP1981097500 U JP 1981097500U JP 9750081 U JP9750081 U JP 9750081U JP S6319902 Y2 JPS6319902 Y2 JP S6319902Y2
- Authority
- JP
- Japan
- Prior art keywords
- emitting diode
- temperature
- light emitting
- transistor
- drive current
- 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.)
- Expired
Links
- 230000005540 biological transmission Effects 0.000 description 3
- 230000006378 damage Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Landscapes
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
- Audible And Visible Signals (AREA)
Description
【考案の詳細な説明】
本考案は車両の発光ダイオード表示回路、特に
車室内に設けられ車両の所定の機能表示を行う発
光ダイオード表示回路に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light emitting diode display circuit for a vehicle, and particularly to a light emitting diode display circuit installed in a vehicle interior and displaying a predetermined function of the vehicle.
車両においては、所定の機能、例えば変速機の
シフト位置を表示するために発光ダイオードが用
いられているが、車室内は温度変化が激しいた
め、半導体素子である発光ダイオードの特性が温
度によつて変化するという問題がある。 Light-emitting diodes are used in vehicles to display certain functions, such as the shift position of a transmission, but due to the rapid temperature changes inside the vehicle, the characteristics of the light-emitting diode, which is a semiconductor element, vary depending on the temperature. The problem is that it changes.
すなわち、発光ダイオードは温度に対して正の
輝度特性を有し、このために、一定の輝度を得る
ためには、常温点灯時に高温点灯時よりも多くの
駆動電流を必要とする。したがつて、駆動電流値
を高温点灯時に合わせて設定すると、常温点灯時
には駆動電流が不足するので輝度が低下して視認
性が非常に悪化するという欠点があつた。一方、
駆動電流値を常温点灯時に合わせて設定すると、
高温点灯時には過大な駆動電流が流れるので発光
ダイオードが劣化、破壊するという欠点があつ
た。 That is, a light emitting diode has a brightness characteristic that is positive with respect to temperature, and therefore, in order to obtain a constant brightness, a larger drive current is required when the light emitting diode is lit at room temperature than when it is lit at a high temperature. Therefore, if the drive current value is set to match the high temperature lighting, there is a problem that the drive current is insufficient during the room temperature lighting, resulting in a decrease in brightness and extremely poor visibility. on the other hand,
If you set the drive current value to match the normal temperature lighting,
The drawback was that an excessive drive current flows during high-temperature lighting, causing the light emitting diode to deteriorate and be destroyed.
本考案は前記従来の課題に鑑み為されたもので
あり、その目的は、発光ダイオードに流れる駆動
電流を温度によつて制御して輝度をほぼ一定にす
るとともに発光ダイオードの劣化、破壊を防ぐこ
とができる車両の発光ダイオード表示回路を提供
することにある。 The present invention was developed in view of the above-mentioned conventional problems, and its purpose is to control the drive current flowing through the light emitting diode according to the temperature to keep the brightness almost constant, and to prevent deterioration and destruction of the light emitting diode. An object of the present invention is to provide a light emitting diode display circuit for a vehicle that can perform the following functions.
前記目的を達成するために、本考案は、車室内
に設けられ車両の所定の機能表示を行う発光ダイ
オードと、該発光ダイオードに供給される駆動電
流を温度によつて制御する温度補償回路とを含
み、温度補償回路は、温度によつて抵抗値が変化
する感温抵抗素子と、発光ダイオードに駆動電流
を供給し感温抵抗素子の抵抗値の変化によつて導
通度が変化するトランジスタと、トランジスタに
並列接続され発光ダイオードに底値駆動電流を供
給する抵抗素子とを有し、発光ダイオードに流れ
る駆動電流を温度によつて制御して輝度をほぼ一
定にするとともに温度が極端に上昇してトランジ
スタがオフした時に底値駆動電流を供給すること
を特徴とする。 In order to achieve the above object, the present invention includes a light emitting diode that is installed in the vehicle interior and displays a predetermined function of the vehicle, and a temperature compensation circuit that controls the drive current supplied to the light emitting diode according to the temperature. The temperature compensation circuit includes: a temperature-sensitive resistance element whose resistance value changes depending on the temperature; a transistor which supplies a drive current to the light-emitting diode and whose conductivity changes according to a change in the resistance value of the temperature-sensitive resistance element; It has a resistor element that is connected in parallel with the transistor and supplies a bottom-level drive current to the light-emitting diode.The drive current flowing through the light-emitting diode is controlled by temperature to keep the brightness almost constant, and when the temperature rises extremely, the transistor It is characterized by supplying a bottom-value drive current when the switch is turned off.
以下、図面に基づいて本考案の好適な実施例を
説明する。 Hereinafter, preferred embodiments of the present invention will be described based on the drawings.
図には、本考案に係る車両の発光ダイオード表
示回路が示されている。 The figure shows a light emitting diode display circuit for a vehicle according to the present invention.
図において、バツテリ１０からの電流は、駆動
電流を温度によつて制御する温度補償回路１４を
介して、発光ダイオード１２に供給される。ここ
で、発光ダイオード１２は、実施例において、車
室内に設けられ、変速機のシフト位置を示す例え
ば４個の発光ダイオード群から成り、図にはその
１つが示されている。そして、バツテリ１０と温
度補償回路１４との間にはヒユージブルリンク１
６とイグニツシヨンスイツチ１８が接続され、温
度補償回路１４と発光ダイオード１２との間には
抵抗２０が接続され、また、発光ダイオード１２
とバツテリ１０との間にはシフト位置検出スイツ
チ２２が接続されている。 In the figure, current from a battery 10 is supplied to a light emitting diode 12 via a temperature compensation circuit 14 that controls the drive current according to temperature. Here, in the embodiment, the light emitting diodes 12 are provided in the vehicle interior and consist of a group of, for example, four light emitting diodes that indicate the shift position of the transmission, one of which is shown in the figure. A fusible link 1 is connected between the battery 10 and the temperature compensation circuit 14.
6 and an ignition switch 18 are connected, a resistor 20 is connected between the temperature compensation circuit 14 and the light emitting diode 12, and a resistor 20 is connected between the temperature compensation circuit 14 and the light emitting diode 12.
A shift position detection switch 22 is connected between the switch and the battery 10.
温度補償回路１４は、温度によつて抵抗値が変
化する感温抵抗素子２４と、発光ダイオード１２
に駆動電流を供給し感温抵抗素子２４の抵抗値の
変化によつて導通度が変化するトランジスタ２６
と、トランジスタ２６の並列接続されトランジス
タ２６のオフ時に発光ダイオード１２に底値駆動
電流を供給する抵抗素子２８とを有している。そ
して、トランジスタ２６のベース端子は、抵抗３
０とテールランプ３２とを介してバツテリ１０の
負極に接続されている。 The temperature compensation circuit 14 includes a temperature sensitive resistance element 24 whose resistance value changes depending on the temperature, and a light emitting diode 12.
A transistor 26 whose conductivity changes according to a change in the resistance value of the temperature-sensitive resistance element 24.
and a resistive element 28 which is connected in parallel with the transistor 26 and supplies a bottom drive current to the light emitting diode 12 when the transistor 26 is off. The base terminal of the transistor 26 is connected to the resistor 3.
0 and the tail lamp 32 to the negative electrode of the battery 10.
また、温度補償回路１４のトランジスタ２６の
ベース・エミツタ間には、トランジスタ２６をオ
フ動作させるためのリレースイツチ３４及びテー
ルランプヒユーズ３６が接続されており、リレー
スイツチ３４はテールランプスイツチ３８によつ
てオンオフ制御されている。 Further, a relay switch 34 and a tail lamp fuse 36 are connected between the base and emitter of the transistor 26 of the temperature compensation circuit 14 for turning off the transistor 26, and the relay switch 34 is controlled to turn on and off by the tail lamp switch 38. has been done.
本考案に係る車両の発光ダイオード表示回路は
以上の構成から成り、以下その作用を説明する。 The light emitting diode display circuit for a vehicle according to the present invention has the above configuration, and its operation will be explained below.
イグニツシヨンスイツチ１８がオン動作される
と、バツテリ１０からヒユージブルリンク１６、
イグニツシヨンスイツチ１８、感温抵抗素子２
４、抵抗３０、テールランプ３２を通つてバイア
ス電流が流れ、このときトランジスタ２６にI1な
るベース電流が流れる。このとき、変速機が該当
するシフト位置に切り替えられると、シフト位置
検出スイツチ２２がオン状態となり、トランジス
タ２６がオン作動して、トランジスタ２６のエミ
ツタ・コレクタ間に抵抗２０、発光ダイオード１
２の経路で駆動電流I2が流れる。 When the ignition switch 18 is turned on, the fusible link 16 is connected to the battery 10.
Ignition switch 18, temperature sensitive resistance element 2
4. A bias current flows through the resistor 30 and the tail lamp 32, and at this time, a base current I1 flows through the transistor 26. At this time, when the transmission is switched to the corresponding shift position, the shift position detection switch 22 is turned on, the transistor 26 is turned on, and the resistor 20 and the light emitting diode 1 are connected between the emitter and collector of the transistor 26.
The drive current I 2 flows through the second path.
以上のようにして、発光ダイオード１２へはト
ランジスタ２６を介して点灯駆動電流が供給され
るが、このときの駆動電流I2の大きさはトランジ
スタ２６の導通度によつて制御されており、本考
案では、この導通度がトランジスタ２６のエミツ
タ・ベース間に接続された感温抵抗素子２４によ
つて所望の温度特性を有するように設定され、こ
の結果、車室内の温度変化に従つて駆動電流I2を
変化させ、発光ダイオード１２に常に最適な電流
が供給されることとなる。 As described above, the lighting drive current is supplied to the light emitting diode 12 via the transistor 26, but the magnitude of the drive current I2 at this time is controlled by the degree of conductivity of the transistor 26, and the actual In the invention, this degree of conductivity is set to have a desired temperature characteristic by the temperature-sensitive resistance element 24 connected between the emitter and base of the transistor 26, and as a result, the drive current changes according to temperature changes in the vehicle interior. By changing I 2 , an optimum current is always supplied to the light emitting diode 12.
通常の場合、温度補償回路１４の感温抵抗素子
２４は常温で発光ダイオード１２へ最適な電流が
供給される特性に選択されている。 Normally, the temperature-sensitive resistance element 24 of the temperature compensation circuit 14 is selected to have a characteristic that allows an optimum current to be supplied to the light-emitting diode 12 at room temperature.
そして、車室内の温度が上昇すると、感温抵抗
素子２４の抵抗値が低くなり、ベース電位P1の
電位が高くなる。したがつて、トランジスタ２６
のエミツタ・ベース電流が小さくなり導通度が低
下し、駆動電流I2の値も低くなるので、高温点灯
時に、発光ダイオード１２には過大な電流が流れ
ることなく、発光ダイオード１２の劣化、破壊を
防止できる。 Then, when the temperature inside the vehicle increases, the resistance value of the temperature-sensitive resistance element 24 decreases, and the potential of the base potential P1 increases. Therefore, transistor 26
The emitter-base current becomes smaller, the degree of conductivity is lowered, and the value of the drive current I2 is also lowered, so that an excessive current does not flow through the light-emitting diode 12 during high-temperature lighting, thereby preventing deterioration or destruction of the light-emitting diode 12. It can be prevented.
車室内の温度がさらに上昇すると、ベース電位
P1の電位がトランジスタ２６のオン作動電圧よ
りも高くなるので、トランジタ２６はオフ作動状
態となる場合が生ずる。しかしながら、本考案に
おいては、トランジスタ２６と並列に抵抗素子２
８が接続されているため、バツテリ１０からは、
底値駆動電流I3が抵抗素子２８、抵抗２０、発光
ダイオード１２の経路で流れる。このときの底値
駆動電流I3は、低い値に設定されているので高温
時にも発光ダイオード１２に損傷を与えることが
ない。 As the temperature inside the vehicle increases further, the base potential
Since the potential of P 1 becomes higher than the on-operation voltage of transistor 26, the transistor 26 may be in the off-operation state. However, in the present invention, the resistor 26 is connected in parallel with the transistor 26.
Since 8 is connected, from battery 10,
The bottom value drive current I 3 flows through the resistance element 28 , the resistor 20 , and the light emitting diode 12 . Since the bottom value drive current I3 at this time is set to a low value, the light emitting diode 12 will not be damaged even at high temperatures.
以上のように、本考案によれば、発光ダイオー
ドに流れる駆動電流を温度によつて制御して輝度
をほぼ一定にすることができる。 As described above, according to the present invention, the drive current flowing through the light emitting diode can be controlled depending on the temperature, so that the brightness can be made almost constant.
また、本実施例では、ベース回路にテールラン
プ３２が設けられており、夜間走行時には発光ダ
イオード１２の駆動電流を所定の低い値に変更す
ることを特徴とする。夜間走行時に、テールラン
プスイツチ３８をオン動作するとリレースイツチ
３４がオン動作し、テールランプ３２が点灯す
る。このとき、接続点P2の電位はバツテリ１０
の電位まで上昇する。したがつて、トランジスタ
２６がオフ状態となる。しかしながら、このとき
も底値駆動電流I3が発光ダイオード１２に流れ、
発光ダイオード１２の点灯が確保される。従つ
て、夜間走行時には発光ダイオード１２を減光し
た状態で点灯することができ、運転者にまぶしさ
を与えることがない。 Further, this embodiment is characterized in that a tail lamp 32 is provided in the base circuit, and the driving current of the light emitting diode 12 is changed to a predetermined low value during night driving. When the tail lamp switch 38 is turned on during night driving, the relay switch 34 is turned on and the tail lamp 32 is turned on. At this time, the potential of the connection point P2 is 10
The potential rises to . Therefore, transistor 26 is turned off. However, at this time as well, the bottom drive current I3 flows to the light emitting diode 12,
Lighting of the light emitting diode 12 is ensured. Therefore, when driving at night, the light emitting diode 12 can be turned on in a dimmed state, and the driver will not be dazzled.
以上説明したように、本考案に係る車両の発光
ダイオード表示回路によれば、発光ダイオードに
流れる駆動電流を温度によつて制御して輝度をほ
ぼ一定にし、発光ダイオードの劣化、破壊を防止
することができるとともに、夜間走行時に発光ダ
イオードの表示を減光することができる。 As explained above, according to the light emitting diode display circuit for a vehicle according to the present invention, the drive current flowing through the light emitting diode is controlled by temperature to keep the brightness almost constant, thereby preventing deterioration and destruction of the light emitting diode. It is also possible to dim the light emitting diode display when driving at night.
図は本考案に係る車両の発光ダイオード表示回
路の回路図である。
各図中同一部材には同一符号を付し、１２……
発光ダイオード、１４……温度補償回路、２４…
…感温抵抗素子、２６……トランジスタ、２８…
…抵抗素子、３４……リレースイツチ、３８……
テールランプスイツチ、I2……駆動電流、I3……
底値駆動電流。
The figure is a circuit diagram of a light emitting diode display circuit for a vehicle according to the present invention. Identical members in each figure are given the same reference numerals, and 12...
Light emitting diode, 14...Temperature compensation circuit, 24...
...Temperature-sensitive resistance element, 26...Transistor, 28...
...Resistance element, 34... Relay switch, 38...
Tail lamp switch, I 2 ... Drive current, I 3 ...
Bottom drive current.
Claims (1)
う発光ダイオードと、該発光ダイオードに供給
される駆動電流を温度によつて制御する温度補
償回路とを含み、温度補償回路は、温度によつ
て抵抗値が変化する感温抵抗素子と、発光ダイ
オードに駆動電流を供給し感温抵抗素子の抵抗
値の変化によつて導通度が変化するトランジス
タと、トランジスタに並列接続され発光ダイオ
ードに底値駆動電流を供給する抵抗素子とを有
し、発光ダイオードに流れる駆動電流を温度に
よつて制御して輝度をほぼ一定にするとともに
温度が極端に上昇してトランジスタがオフした
時に底値駆動電流を供給することを特徴とする
車両の発光ダイオード表示回路。 (2) 実用新案登録請求の範囲(1)記載の回路におい
て、温度補償回路内のトランジスタと並列接続
され夜間走行時にオン作動されるスイツチを有
し、該スイツチのオン時にトランジスタがオフ
となり抵抗素子から発光ダイオードに底値駆動
電流を供給して発光ダイオードの輝度を低下さ
せることを特徴とする車両の発光ダイオード表
示回路。[Scope of Claim for Utility Model Registration] (1) Includes a light emitting diode installed in the vehicle interior and displaying a predetermined function of the vehicle, and a temperature compensation circuit controlling the drive current supplied to the light emitting diode according to temperature. The temperature compensation circuit consists of a temperature-sensitive resistance element whose resistance value changes depending on the temperature, a transistor that supplies a drive current to the light-emitting diode and whose conductivity changes according to the change in the resistance value of the temperature-sensitive resistance element, and a transistor. The drive current flowing through the light emitting diode is controlled by temperature to keep the brightness almost constant, and when the temperature rises extremely, the transistor A light emitting diode display circuit for a vehicle, characterized in that it supplies a bottom value driving current when turned off. (2) The circuit described in claim (1) for utility model registration has a switch that is connected in parallel with the transistor in the temperature compensation circuit and is turned on when driving at night, and when the switch is turned on, the transistor is turned off and the resistor element is turned on. A light emitting diode display circuit for a vehicle, characterized in that the luminance of the light emitting diode is reduced by supplying a bottom value driving current to the light emitting diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1981097500U JPS585085U (en) | 1981-06-30 | 1981-06-30 | Vehicle light emitting diode display circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1981097500U JPS585085U (en) | 1981-06-30 | 1981-06-30 | Vehicle light emitting diode display circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS585085U JPS585085U (en) | 1983-01-13 |
| JPS6319902Y2 true JPS6319902Y2 (en) | 1988-06-02 |
Family
ID=29892303
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1981097500U Granted JPS585085U (en) | 1981-06-30 | 1981-06-30 | Vehicle light emitting diode display circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS585085U (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101646290B (en) * | 2008-08-06 | 2012-10-31 | 夏普株式会社 | Led drive circuit |
| JP2011009474A (en) * | 2009-06-25 | 2011-01-13 | Panasonic Electric Works Co Ltd | Light emitting diode driving apparatus, and luminaire, lighting device for vehicle interiors and lighting device for vehicles employing the same |
| JP5881346B2 (en) * | 2011-09-15 | 2016-03-09 | 三菱電機照明株式会社 | Constant current circuit and LED driving constant current circuit |
| JP2016106418A (en) * | 2016-02-02 | 2016-06-16 | 三菱電機照明株式会社 | Constant current circuit and light-emitting diode driving constant current circuit |
-
1981
- 1981-06-30 JP JP1981097500U patent/JPS585085U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS585085U (en) | 1983-01-13 |
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