JPH07335941A - Non-polar LED - Google Patents

Abstract

(57) [Summary] [Construction] In an LED in which an anode A and a cathode K electrode are formed above and below a P-N junction of a semiconductor, and an LED chip PD1 for causing a current to flow therethrough to emit light is incorporated in a protective cover C. The circuit formed by the rectifying diode chips D1 to D4 and the LED chips PD1 and PD2 is built in the protective cover to eliminate the polarity of the LED. [Effect] It is not necessary for the user to carefully perform wiring and mounting work while paying attention to polarity, and workability is greatly improved. Also, when manufacturing a printed circuit board, LE
The design is easy because the polarity of D can be ignored. Also, since the manufacturer does not need the marking for displaying the polarity, the manufacturing cost can be reduced. Especially in the production of taping parts for automatic insertion, the productivity is greatly improved because the troublesome sorting process of sticking the LEDs with the same polarity on the tape and the confirmation work are eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED (light emitting diode), and more specifically, an LE that can be used without considering the polarity.
It is related to D.

[0002]

2. Description of the Related Art Conventionally, LEDs have been widely used as a display or a light source.

Generally, the former is used as a power source display for home electric appliances, sound, communication equipment, or the like, or the status display of equipment, and the latter is used as an optical sensor, a document reading light source of a copy machine, an LED array for writing, or the like. Used. As described above, LEDs used in various fields are mounted on a printed circuit board or an operation panel inside a device, and light emission is controlled according to each application.

FIG. 2 shows the appearance and internal structure of a general light emitting diode (LED) which has been conventionally used.

A semiconductor (PN junction) is formed on the electrode D in the figure.
The LED chip (not shown) is mounted. Further, the electrode D has an anode terminal T1 and a cathode terminal T2.
Are connected, and the whole is protected by a plastic protective cover C formed by an epoxy resin mold in order to increase the mechanical strength of the LED chip. A part of the lower edge of the protective cover C is cut off. This is a marking M for displaying the polarity of the LED, which is a polarized component, and the anode terminal T1 and cathode terminal T2.
There is also a polarity display by changing the length and diameter of.

As described above, since the LED has electrical polarity, it is necessary to connect + to the anode terminal and-to connect to the cathode terminal to emit light, as shown in FIG. 3, and the user depends on the above-mentioned polarity display for the LED. Are mounted in the correct direction and are wired.

[0007]

However, such a polar component may become inoperable if it is mistakenly connected in the opposite direction, or the element may be destroyed depending on the applied reverse voltage value. The user had to pay close attention to the polarities of the components when mounting and wiring, and the workability was extremely poor.

Further, when manufacturing a printed circuit board, the designer matches the polarities of the LEDs in consideration of the ease of mounting (unifies the mounting direction), which makes the pattern wiring complicated and causes a hard bug. However, silk-screen printing or the like indicating the mounting direction is also required on the substrate.

Also for the manufacturer side, the LED needs the polarity indication due to the above-mentioned notches and terminal lengths, so that the productivity is poor, and especially for the taping parts for automatic insertion shown in FIG. A labor-intensive process of aligning the polarities in the same direction and pasting them on the tape is required, and the confirmation work is required at the time of shipping, which also greatly affects the productivity.

The object of the present invention is to eliminate the drawbacks of such a polarized component and to simply mount it without considering its polarity.
It is to provide a non-polar LED that can be wired.

[0011]

In the present invention, the semiconductor P
In an LED in which an anode (A) electrode and a cathode (K) electrode are formed above and below the -N junction, and an LED chip that causes a current to flow therethrough to emit light is built in a protective cover (C),
In addition to the above LED chip (PD1), another LED chip (PD
2) Anti-parallel connection of both LED chips (PD1 PD2)
Is built in the protective cover (C).

As another method, four rectifying diode chips (D1, D2, D3, D4) are bridge-connected to form a diode bridge circuit (1), and the LED bridge is connected to the LED. The chip (PD1) is connected in parallel and built in the protective cover (C).

As still another method, a rectifying diode chip (D1) is connected in reverse parallel to the LED chip (PD1) to form a first diode circuit (2),
The second rectifier diode chip (D2) is connected in reverse parallel to the LED chip (PD2) other than the D chip (PD1) to form the second diode circuit (3), and the above two LEDs are provided.
The first and second diode circuits (2, 3) are connected in series so that the chips (PD1, PD2) face each other and are built in the protective cover (C).

[0014]

[Operation] In the first configuration, in which two LED chips are connected in anti-parallel, when a + voltage is applied to the terminal (T1), L
The ED chip (PD1) emits light, and the LED chip (PD2)
) Does not emit light. Conversely, when a + voltage is applied to the terminal (T2), the LED chip (PD2) emits light and the LED chip (PD1) does not emit light.

Further, four rectifying diode chips (D1,
Connect D2, D3, D4) to a bridge and connect it to the LED
In the second configuration in which the chips (PD1) are connected in parallel, even if a + voltage is applied to the terminal (T1), the terminal (T2)
), The LED chip (PD1) emits light even if a + voltage is applied.

Further, a diode circuit (2) formed by connecting an LED chip (PD1) to a rectifying diode chip (D1) in anti-parallel and similarly connecting an LED chip (PD2) to an rectifying diode chip (D2) in anti-parallel. In the third configuration in which the diode circuit (3) thus formed is connected in series, when the + voltage is applied to the terminal (T1), the LED chip (PD1) emits light and the LED chip (PD2) does not emit light. Conversely, when a + voltage is applied to the terminal (T2), the LED chip (PD2) emits light and the LED chip (PD1) does not emit light.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a circuit (one-dot chain line frame) built in a protective cover C according to the present invention, in which each element is mounted on an electrode D in the protective cover C. These are circuits for making the LED non-polarized, and details thereof will be described below.

FIG. 1 (a) shows a first embodiment of the present invention, in which an LED chip PD1 and another LED chip PD2 are reversed so that the anode A or the cathode K of both chips are in opposite directions. The structure is such that the two LED chips PD1 and PD2 are connected in parallel and the protective cover C is built therein.
Here, as the protective cover C, there are various types such as one molded with an epoxy resin, one having a can seal (protective can) with a chip, and one covered with a plastic case.

FIG. 1 (b) shows a second embodiment,
This is a structure in which four rectifying diode chips D1 to D4 are bridge-connected to form a diode bridge circuit 1 and an LED chip PD1 is connected in parallel with the diode bridge circuit 1 and built in a protective cover C.

FIG. 1 (c) shows a third embodiment of the LE.
The rectifying diode chip D1 is connected in anti-parallel to the D chip PD1 to form the diode circuit 2, and similarly, the rectifying diode chip D2 is connected in anti-parallel to the LED chip PD2 to form the diode circuit 3, and two LED chips PD1 are formed. ,
This is a structure in which the diode circuits 2 and 3 are connected in series so that the anode and cathode of PD2 face each other and are built in the protective cover C. Also, T1 and T shown in FIG.
Reference numeral 2 is a voltage application terminal for lighting the LED, which is the anode terminal T1 or the cathode terminal T2 shown in FIG.
Is equivalent to.

The internal structure of the LED according to the present invention has been described above, and its operation will be described below.

According to the above-described first embodiment, + is applied to the terminal T1.
When a voltage is applied, the LED chip PD1 is forward biased and a forward current flows and the LED chip PD1 emits light, but at this time, the LED chip PD2 is reverse biased and does not emit light. Conversely, if a + voltage is applied to terminal T2,
Since the LED chip PD2 is forward biased, the LED chip PD2 emits light and the LED chip PD1 does not emit light.

In the second embodiment, when a + voltage is applied to the terminal T1, a current flows through the rectifying diode chip D1 to the LED chip PD1 to the rectifying diode chip D4 to the terminal T2, and the LED chip PD1 emits light. Conversely, terminal T2
When + voltage is applied to the rectifier diode chip D3 ~
A current flows through the LED chip PD1 to the rectifying diode chip D2 to the terminal T1 and the LED chip PD1 emits light.

In addition, in the third embodiment, when a + voltage is applied to the terminal T1, a current flows through the LED chip PD1 to the rectifying diode chip D2 to the terminal T2, and the LED chip PD1.
Emits light. In this case, the LED chip PD2 is reverse biased and does not emit light. On the contrary, when + voltage is applied to the terminal T2, the LED chip PD2 ~ the rectifying diode chip D1 ~
A current flows through the terminal T1 and the LED chip PD2 emits light. In this case, the LED chip PD1 is reverse biased and does not emit light.

In the case of the first embodiment described above, one L
While the ED chip is forward-biased and emits light, the other LED chip is reverse-biased, but it is necessary to consider that the LED generally has a low reverse voltage and is easily destroyed. In order to prevent the destruction of the LED due to this reverse voltage, L
FIG. 5 shows an example in which a rectifying diode chip is connected in series to an ED chip.

The operation of the non-polar LED in each configuration has been described above. However, when the LED is forward biased, it is necessary to insert an appropriate resistor in series in order to limit the forward current flowing through the element. Is omitted here.

As described above, by mounting each circuit described above on the existing LED chip, the LED can emit light regardless of the polarity of the voltage applied between the terminals T1 and T2. In other words, the LED of the present invention does not need to have the same polarity as the conventional product, and can be freely mounted and wired. Since the light emitting chips and rectifying diode chips necessary for that are mounted on the electrodes D inside the protective cover C, the size of the LED is the same as the conventional product,
Moreover, the mark M for displaying the polarity, which was required in the conventional product, is not necessary at all.

[0028]

As described above, according to the present invention, L
Rectifier diode chip and LED in the protective cover of ED
Since the circuit configured by the chip is built in and the polarity of the LED is eliminated, there is no trouble such as malfunctioning and destruction of the element by connecting in reverse as in the conventional product. Therefore, it is not necessary for the user to carefully perform wiring and mounting work while paying attention to the polarity, and workability is greatly improved. When manufacturing a printed circuit board, LE
Since the polarity of D can be ignored, the design is easy, and the pattern wiring is simplified, so that malfunctions due to pattern mistakes and the like can be improved.

Further, since the manufacturer does not need the marking for displaying the polarity, the manufacturing cost can be reduced. Especially in the production of taping parts for automatic insertion, the productivity is greatly improved because the troublesome sorting process of sticking the LEDs with the same polarity on the tape and the confirmation work are eliminated.

[Brief description of drawings]

FIG. 1 is a diagram showing an internal circuit of a non-polar LED according to the present invention.

FIG. 2 is a diagram showing the appearance and internal structure of a conventional LED.

FIG. 3 is a diagram showing an internal circuit of a conventional LED.

FIG. 4 is a diagram showing a taped LED.

5 is a diagram showing an internal circuit of a non-polar LED different from that in FIG.

[Explanation of symbols]

 1 Diode bridge circuit 2, 3 Diode circuit D1, D2, D3, D4 Rectifying diode chip PD1, PD2 LED chip A Anode K Cathode D Electrode C Protective cover

Claims (3)

[Claims] 1. A protective cover (C) is provided with an LED chip (PD1) having an anode (A) electrode and a cathode (K) electrode formed above and below a P-N junction portion of a semiconductor and emitting a current through the electrode. In the LED consisting of the above, the above LED chip (PD1) is replaced with another LED chip (PD
2) are connected in anti-parallel and both LED chips (PD1, PD2
) Is incorporated in the above-mentioned protective cover (C). 2. A protective cover (C) is provided with an LED chip (PD1) having an anode (A) electrode and a cathode (K) electrode formed above and below a P-N junction of a semiconductor and emitting an electric current through the anode (A). In the LED consisting of four rectifying diode chips (D1, D2, D3, D4
) Bridge connection diode bridge circuit (1)
To form the LE in the diode bridge circuit (1).
A non-polar LED in which a D chip (PD1) is connected in parallel and built in the protective cover (C). 3. An anode (A) and cathode (K) electrodes are formed above and below a P-N junction of a semiconductor, and an LED chip (PD1) that causes a current to flow therethrough to emit light is built in a protective cover (C). In the LED, the first diode circuit (2) is formed by connecting the LED chip (PD1) and the rectifying diode chip (D1) in antiparallel.
LED different from the above LED chip (PD1)
Another rectifier diode chip (D2) to the chip (PD2)
Are connected in anti-parallel to form a second diode circuit (3), and the first and second diode circuits (2, 3) are connected so that the two LED chips (PD1, PD2) face each other. A non-polar LED which is connected in series and built in the protective cover (C).