JP2001035208A - Vehicle lamp using led - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with a current limiting resistor in a lamp comprising a plurality of LED connected between the LED and a power source or ground and also connected LEDs to each other by using a resistance wire as the wiring. SOLUTION: When an arbitrary point on the current inlet side of a positive- side wiring 8 is A, and an arbitrary point on the current outlet side of a ground wire 7 is B, the total length of the wirings 7 and 8 from A to B is the same for any LED. In LED 1, the length of the positive-side wiring 8 from point A to LED 1 is P1, the length of the ground wire 7 from LED 1 to point B is Q1, and the length of a resistance line from A to B is P1+Q1. In LED 2, the length of the positive-side wiring 8 from point A to LED 2 is P2, the length of the ground wire 7 from LED 2 to point B is Q2, and the length of the resistance wire from A to B is P2+Q2. The length of the resistance wire is equal to P1+Q1=P2+Q2, and for other LED 3 and LED 4, the currents carried to all the LED are equal to each other from similar principle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular lamp using an LED (Light Emitting Diode), for example, applied as a rear combination lamp.

[0002]

2. Description of the Related Art FIG. 7 shows a vehicle lamp 100 of this type. This vehicle lighting device 100 includes a plurality of LEDs 1, 1,.
Are connected by wiring. The LED 1 itself consumes less current than a lamp using a filament,
It has excellent features such as long service life, strong vibration, and low heat generation, and is widely used in vehicle lamps. However, since a single LED 1 has weaker light than a bulb-type lamp, it is used as a vehicle lamp. Are used in combination with a plurality of LEDs 1, 1,.

The LED 1 is an element that is turned on by current control, and has a large change in current with respect to a change in voltage, and has a variation in terminal voltage even with the same current. In the case of the vehicular lamp 100 driven by the constant voltage, a circuit is configured by combining a plurality of LEDs 1, 1,...

FIG. 6 shows a circuit example of a vehicle lamp 100 in which a plurality of LEDs 1, 1,... Are combined. In the illustrated example, a current limiting resistor 13 is connected to a series circuit of four LEDs 1, 1,..., And a series circuit of the LED 1 and the current limiting resistor 13 is combined in parallel. A current flows from the plus terminal to the LED 1 via the rectifying diode 14 and the current limiting resistor 13 so that each LED 1 is lit.

[0005]

As described above, in the circuit configuration in which the current limiting resistor 13 is connected in series with the LED 1, the nearby LED 1 is thermally damaged by the heat generated by the current limiting resistor 13, and the luminous intensity and the life are reduced. Easy to fall. Further, since heat is concentrated near the current limiting resistor 13, heat radiation is poor, and the entire LE
Affects D1. Furthermore, a printed circuit board is required to connect the current limiting resistor 13, which complicates the circuit configuration, and has a problem that the degree of freedom of the position of the LED 1 is small and the layout is limited.

The present invention has been made in view of the above points, and provides a vehicular lamp using an LED which eliminates the above-mentioned disadvantage by eliminating the need for a current limiting resistor by using a resistance wire for wiring. The purpose is to do.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of LEDs are used for each LED.
A vehicular lamp using an LED in which an ED is connected to a power source, a ground, and each LED by a wiring, wherein a resistance wire is used for the wiring.

Therefore, according to the first aspect of the present invention, since heat generation is dispersed by the resistance wire, the heat radiation is improved and the LE is improved.
The reliability and life of D are improved, and a printed circuit board for connecting a current limiting resistor is not required, thereby simplifying the circuit configuration.

According to a second aspect of the present invention, there is provided a vehicular lamp using the LED according to the first aspect, wherein an anode and a cathode of the LED are connected in parallel with a positive wire and a ground wire, respectively. The present invention is characterized in that the current inlet side of the positive side wiring and the current outlet side of the ground wire are located on mutually opposite sides.

Therefore, according to the present invention, the length of the resistance wire from any point on the current inlet side of the plus side wiring to any point on the current outlet side of the ground wire is the same for all LEDs. Thus, the current flowing through all the LEDs becomes equal.

According to a third aspect of the present invention, there is provided a vehicular lamp using the LED according to the first or second aspect, wherein the plurality of LEDs are arranged on a substrate in a vertical and a column direction, and are arranged in adjacent columns. The anodes and the cathodes of the LEDs are arranged and mounted in a direction facing each other, and a common positive wiring and a ground wire are connected to the anode and the cathode, respectively.

Therefore, according to the third aspect of the present invention, the LE
The common wire for the plus side of D and the ground wire can be used.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The same members or those having the same functions as those in FIG. 6 are denoted by the same reference numerals.

FIG. 1 shows an example of an LED circuit of a vehicular lamp using the LED of the present invention, in which a series circuit of four LEDs 1 is connected in parallel. In the present invention, all of the wires connecting the LEDs 1, that is, the wires 2 from the power supply (not shown) to the LEDs 1 via the rectifying diodes 14, the wires 3 connecting the LEDs 1, the ground wires 4, and the like. In this configuration, a resistance wire is used, and the conventional current limiting resistor 13 is eliminated. As the LED 1, a four-leg type LED is used.

FIG. 2 shows an example in which a wiring 5 is also provided between the cathode and the anode of the LEDs 1 connected in series to form a matrix.

Note that the LED circuits shown in FIGS. 1 and 2 are merely examples, and any circuit that uses resistance wires for all the wires connecting the LEDs 1 can use any known number of LEDs 1 or a connection method. Such a circuit may be used.

FIG. 3 shows an LED vehicle lamp applied to a vehicle, and FIG. 5 shows an equivalent circuit thereof. On the substrate 6, three LEDs 1 are arranged vertically and four LEDs 1 are arranged horizontally (in a column direction), and are arranged and mounted in an orderly manner. In FIG. 3, the cathode 1b side is indicated by oblique lines for easy understanding.
Among the LEDs 1, the LED (L1) in the first row and the LED (L2) in the second row are arranged in a direction in which the cathode 1b side faces each other, and the LED (L2) in the second row and the LED in the third row are arranged.
(L3) is the direction in which the anodes 1a face each other. The anode 1a is connected to a common plus side (power supply side) wiring 8, and the cathode 1b is connected to a common ground line 7. That is, each LED 1 is configured to be connected one by one in parallel via the plus side wiring 8 and the ground wire 7 (see FIG. 5). It should be noted that also in the present embodiment, all the wirings 7, 8, 9, and
Needless to say, a resistance wire is used for 10. At this time, the resistance value can be set optimally by selecting the type and length of the resistance wires constituting the wirings 7, 8, 9, and 10, whereby the variation in current to the LED 1 is eliminated, and a stable operation is obtained. Can be

According to the above configuration, the length of the wiring (resistance wire) between any one point on the current inlet side (power supply side) and any one point on the current outlet side (earth side) is the same for all LEDs 1, 1,. Become uniform. This principle will be described with reference to FIG.

FIG. 4 is a view in which a portion of the LED (L1) in the first row of FIG. 3 is extracted.
The numbers 1, 2, LED3, LED3 and LED4 are given. Assuming that an arbitrary point on the current inlet side of the plus side wiring 8 is A and an arbitrary point on the current outlet side of the ground wire 7 is B, from A to B
The total length of wiring (resistance wire) 8 and 7 up to which LE
The same goes for D.

For example, in the LED 1, L
The length of the plus side wiring 8 leading to ED1 is P1, and LE
The length of the ground wire 7 from D1 to point B is Q1,
The length of the resistance line from B to B is P1 + Q1. In the LED 2, the length of the plus side wiring 8 from the point A to the LED 2 is P2, the length of the ground wire 7 from the LED 2 to the point B is Q2, and the length of the resistance line from A to B is That is, P2 + Q2. Resistance wire length = P1 +
Q1 = P2 + Q2 and other LED3, LED4
Is the same principle, and the length of the resistance line from A to B is the same for all LEDs. This means that all LEDs
Are equal to each other. this is,
As shown in FIGS. 3 to 5, the LEDs 1 are connected one by one in parallel with the plus side wiring 8 and the ground line 7, and the current inlet side (plus side) and the current outlet side (ground side) are opposite to each other. This is an effect due to the configuration in which they are positioned.

Also, as shown in FIG.
(L1) and the second row of LEDs (L2) are arranged in a direction in which the cathode 1b side faces each other, and the second row of LEDs (L2) and the third row of LEDs (L3) are arranged in a direction in which the anode 1a side faces each other. By doing so, the ground line 7 and the plus side wiring 8 can be shared, the circuit configuration is simple, and the wiring space is small.

As described above, in this embodiment, since the resistance wires are used for the wirings 7, 8, 9, and 10, the current limiting resistor 13 which is conventionally indispensable is not required.
The connection of the current limiting resistor also eliminates the need for a printed circuit board, simplifies the circuit configuration, and disperses the heat generated by the resistance wires, thereby improving heat dissipation and improving the reliability and life of the LED. .

[0023]

As described in detail above, according to the first aspect of the present invention, since the resistance wire is used for the wiring, the current limiting resistance is not required, and the heat is distributed by the resistance wire of the wiring. ,
The heat dissipation is improved, and the reliability and life of the LED are improved.

Further, a printed circuit board for connecting the current limiting resistor becomes unnecessary, and the circuit configuration is simplified. In addition, by selecting the type and length of the resistance wire, the resistance value can be set optimally, whereby the variation of the current with respect to the LED is eliminated, and a stable operation can be obtained.

According to the second aspect of the present invention, the LE
The anode and the cathode of D are connected in parallel with the plus side wiring and the ground wire, respectively, and the current inlet side of the plus side wiring and the current outlet side of the ground wire are taken on opposite sides. In addition to the effect, the length of the resistance wire from any point on the current inlet side of the plus side wiring to any point on the current outlet side of the ground wire becomes the same for all LEDs, and as a result, the current flowing through all the LEDs Becomes even.

According to the third aspect of the present invention, the anodes and the cathodes of the LEDs in the adjacent rows are arranged in directions facing each other, and the anode and the cathode are connected to a common positive wiring and a ground line. In addition to the effects of the first and second aspects of the present invention, the positive wiring and the ground wire of the LED can be shared, the circuit configuration is simplified, and the common positive wiring and the ground wire are uniform. Heat dispersion becomes possible.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an example of an LED circuit of a vehicle lamp using the LED of the present invention.

FIG. 2 is a circuit diagram showing another example of an LED circuit of a vehicle lamp using the LED of the present invention.

FIG. 3 is an LED module diagram showing an embodiment of a vehicular lamp using the LED of the present invention.

FIG. 4 is a view showing a part of the LED module diagram of FIG. 3;

FIG. 5 is an equivalent circuit diagram of the LED module diagram of FIG. 3;

FIG. 6 is a conventional LED circuit diagram.

FIG. 7 is a front view of a main part of a vehicular lamp using a general LED.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LED 1a Anode 1b Cathode 2, 3, 5 Wiring 6 Substrate 7, 10 Ground wire (wiring) 8, 9 Positive wiring (wiring)

Claims (3)

[Claims] 1. An LE comprising a plurality of LEDs, wherein each LED is connected to a power source and a ground and between the LEDs by wiring.
A vehicular lamp using D, wherein a resistance wire is used for the wiring. 2. An anode and a cathode of the LED are connected in parallel with a positive wire and a ground wire, respectively, and a current inlet side of the positive wire and a current outlet side of the ground wire are located on opposite sides of each other. The vehicular lamp using the LED according to claim 1, wherein the vehicular lamp is configured as described above. 3. A plurality of LEDs are arranged in a vertical and column direction on a substrate, and anodes and cathodes of LEDs in adjacent rows are arranged and mounted in directions facing each other. 3. A vehicular lamp using an LED according to claim 1, wherein a common positive wiring and a ground wire are connected to the respective sides.