JP5282751B2 - LED bulb - Google Patents

Description

  The present invention relates to improvements in LED bulbs.

LED bulbs are attracting attention from the viewpoints of power saving and durability. For example, in the existing incandescent lamp, the lifetime of the light emitting part is 1000 hours, for example, whereas the lifetime of the LED module is 40,000 hours.
However, in the LED light bulb, the AC of the commercial power supply must be rectified and smoothed to be converted into DC, and this DC must be applied to the LED module. A bridge circuit is used as means for rectifying alternating current, and an electrolytic capacitor is used as means for smoothing. Such a power supply circuit is built in the housing of the LED bulb. When a sufficient amount of light is extracted from the LED bulb, there is a large amount of heat generated from the LED module, and this heat affects the life of the electrolytic capacitor for smoothing. Despite the long life of the LED module, the thermal deterioration of the electrolytic capacitor is a cause of reducing the life of the LED bulb.
Therefore, conventionally, the housing of the LED bulb is formed of a heat dissipating material (aluminum alloy or the like) and fins are provided on the housing. Furthermore, it has been proposed to dispose an electrolytic capacitor that is likely to be thermally deteriorated in the base part of the housing (the furthest away from the LED module) (see Patent Document 1 and Patent Document 2).

JP 2000-106028 A JP 2009-206104 A

When the electrolytic capacitor of the power supply circuit is arranged in the base part, the electrolytic capacitor is separated from the LED module, so that the thermal influence from the LED module can be reduced.
However, when the installation location of the electrolytic capacitor, which is one element in the power supply circuit, is fixed, the arrangement of other elements (bridge circuit, resistor, etc.) is limited. Furthermore, restrictions are imposed on the wiring for the LED module and the base.

Under such restrictions, the inventor has intensively studied in order to optimize the arrangement of each element on the circuit board and the power supply lines (input lines and output lines) of the circuit board.
As a result, the inventors have arrived at the present invention described below. That is,
An LED bulb connected to an AC power source,
An LED module;
A housing part in which the LED module is disposed on one end side and a base is disposed on the other end side;
An input unit connected to the base, a bridge circuit, an electrolytic capacitor, and an output unit connected to the LED module, and a circuit board built in the housing unit,
The electrolytic capacitor is mounted on one end of the circuit board and is located in the base of the housing part, the bridge circuit is arranged on the other end side of the circuit board, and the input part is arranged on the bridge circuit side The output part is disposed on the electrolytic capacitor side,
The input unit and the base are connected by an input power line, the output unit and the LED module are connected by an output power line, and the input power line and the output power line are separated from the circuit board. An LED bulb characterized by that.

According to the first aspect of the present invention thus defined, since the electrolytic capacitor is disposed in the base of the housing portion, not only the thermal influence from the LED module is reduced, but also the bridge circuit side ( That is, there is an input section on the LED module side, and the input section and the base of the housing section are connected by an input power line, while the output section is on the other side of the electrolytic capacitor (that is, the base side). Connected by output power line.
In the circuit board, the input part is arranged on the LED module side (that is, the part far from the base of the connection destination), and the output part is arranged on the base side of the connection destination (that is, the part far from the LED module of the connection destination). Therefore, the input power supply line and the output power supply line cross each other.
It is also conceivable to pattern these input power lines and output power lines on a circuit board. However, since a large current flows through the power supply line, the pattern becomes relatively wide. On the other hand, the width of the internal space is limited due to a requirement for forming a heat radiation fin in the housing. Since the width of the circuit board built in such an internal space is also limited, it is difficult to cross a wide power supply line as a circuit pattern on the circuit board. Therefore, in the first aspect of the present invention, the input power supply line and the output power supply line are wired in the air. Since the casing is generally cylindrical, even if the width is narrow, there is a space when viewed three-dimensionally. Arranging the input power supply line and the output power supply line in the space improves the design freedom of the circuit board.

The second aspect of the present invention is defined as follows. That is,
In the LED light bulb defined in the first aspect, the input power supply line and the output power supply line are disposed on one side of the circuit board.
According to the LED bulb of the second aspect thus defined, the input power supply lines and the output power supply lines that cross each other are collected on one side of the circuit board. As a result, the input power supply line and the output power supply line wired in the air in a narrow space in the housing are collected in a compact manner, and interference with other elements can be reduced.

The third aspect of the present invention is defined as follows. That is,
In the prescribed LED light bulb according to the second aspect, the input power line is more rigid than the output power line.
By making one of the power supply lines integrated on one side of the circuit board higher in rigidity than that of the other, one power supply line becomes the core, making it easy to combine the two and stabilizing after the integration . Here, the front end of the input power line protrudes from the through hole of the base, and is then welded to the base. Therefore, if the rigidity of the input power supply line connecting the input unit and the base is increased (in other words, the input power supply line is not easily buckled), the tip of the input power supply line is attached when the circuit board is assembled to the housing. Is guided by the inner peripheral surface of the base and automatically protrudes from the through-hole of the base, facilitating the assembly work.

It is a front view of the LED bulb of embodiment of this invention. It is a longitudinal cross-sectional view of an LED bulb. It is a cross-sectional view similarly. It is a partial expanded sectional view of a nozzle | cap | die.

Hereinafter, an LED bulb according to an embodiment of the present invention will be described.
The LED bulb 1 according to the embodiment includes a housing unit 10 and a translucent cover 50 as shown in FIG. The housing part 10 includes a cylindrical outer cylinder part 11, a resin case 13 inserted into the corresponding part 11, and a base 15 attached to the distal end side of the resin case 13.
The outer cylinder portion 11 is formed of a metal material (aluminum alloy) having high thermal conductivity, and fins 12 are provided upright on the peripheral surface of the outer cylinder portion 11 to improve heat dissipation efficiency.
The resin case 13 is made of a synthetic resin (fluororesin, polyamide, etc.) having high insulation and heat resistance, and the large diameter portion thereof is fitted to the inner peripheral surface of the outer cylinder portion 11 without any gap (see FIG. 2). A base 15 is fitted into the small diameter portion of the resin case 13. A groove 14 into which a circuit board 20 described later is inserted is formed on the inner periphery of the resin case 13.
The base 15 has a shape that can be screwed into a general socket, and a through hole 16 is formed at the center thereof. The input power line 31 is inserted through this through hole.

Reference numeral 20 denotes a circuit board inserted into the resin case 13. The peripheral edge of the circuit board 20 is inserted into a groove 14 formed on the inner peripheral surface of the resin case 13. The circuit board 20 is made of a heat resistant resin such as polyamide. Various elements constituting the power supply circuit of the LED module 51 are mounted on the circuit board 20. In the power supply circuit, a bridge circuit 21 for rectifying an input alternating current and an electrolytic capacitor 22 for smoothing the bridge circuit 21 are arranged in the direction of current flow. Accordingly, the input unit 24 to which AC power is input in the circuit board 20 is disposed near the bridge circuit 21, and the output unit 25 that applies a direct current to the LED module 51 is disposed near the electrolytic capacitor 22.
In this example, the electrolytic capacitor 22 is disposed at one end of the circuit board 20 and is disposed inside the base 15 in the housing unit 10. Thereby, the longest distance can be taken between the electrolytic capacitor 22 and the LED module 51, and the thermal influence from the LED module 51 on the electrolytic capacitor 22 can be minimized.

As a result, as is apparent from FIG. 2, the input unit 24 is located far from the base 15, and similarly, the output unit 25 is located far from the LED module 51.
In this example, the input power line 31 is suspended between the input unit 24 and the base 15. That is, the input power supply line 31 is fixed only at both ends thereof, and the other part is in a state of floating from the circuit board 21. Here, the input power line 31 includes a pair of cords 31-1, 31-2 (see FIG. 3). When assembled, the cord 31-1 passes through the through hole 16 of the base 15 in the state of FIG. 2 is drawn from between the base 15 and the resin case 13.
An output power line 33 is suspended between the output unit 25 and the LED module 51. That is, the input power supply line 31 is fixed only at both ends thereof, and the other part is in a state of floating from the circuit board 21. The output power line 33 includes a pair of cords 33-1 and 33-3.

Since the input unit 24 is far from the base 15 that is the connection destination and close to the LED module 51, the output unit 25 is also far from the LED module 51 that is the connection destination and close to the base 15. The input power supply line 31 and the output power supply line 33 cross each other.
At this time, since the input unit 24 and the output unit 25 are arranged so as to be biased to one side in the circuit board 20, the input power supply line 31 and the output power supply line 33 can be easily bundled.
Further, by making the input power supply line 31 thicker than the output power supply line 33 and increasing its rigidity, the input power supply line becomes a core, and the work of bundling them together (bundling work) becomes easy. Furthermore, although it is necessary to make the front end of the input power supply line 31 protrude from the through hole 16 of the base 15, it is easy to make the input power line 31 protrude by increasing its rigidity (ie, buckling resistance). That is, when the input power supply line 31 and the output power supply line 33 are attached and the circuit board 20 is inserted from the large diameter side of the casing 10 in a state where the input power supply line 31 and the output power supply line 33 are combined, the input power supply line 31 is biased to one side. However, the tip is guided by the inner peripheral surface of the base 15 due to its rigidity, and the through hole 16 at the tip of the base 15 is automatically inserted. Since the output power supply line 33 has a reduced rigidity, it does not hinder the front end of the input power supply line 31 from being automatically guided to the through hole 16.
From the viewpoint of work efficiency, the tip of the input power supply line 31 is first soldered to the base 15, and then the tip of the output power supply line 33 is soldered to the LED module 51. The handling becomes easy by keeping the rigidity low.
In this example, the type (diameter) of the cord used for the input power supply line 31 is AWG22 (0.64 mm), and the type (diameter) of the cord used for the output power supply line 33 is AWG28 (0.32 mm).

The translucent cover 50 is formed of a cloudy material (glass or synthetic resin). Reference numeral 53 denotes a partition plate that closes the large-diameter side opening of the housing 10 and fixes the LED module 51 at the center thereof.
The LED module 51 includes a single or a plurality of LEDs. The LED can be of any light emitting color, but is preferably a white light emitting LED.

  The present invention is not limited to the description of the embodiments and examples of the invention described above. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.

Claims (3)

An LED bulb connected to an AC power source,
An LED module;
A housing part in which the LED module is disposed on one end side and a base is disposed on the other end side;
An input unit connected to the base, a bridge circuit, an electrolytic capacitor, and an output unit connected to the LED module, and a circuit board built in the housing unit,
The electrolytic capacitor is mounted on one end of the circuit board and is located in the base of the housing part, the bridge circuit is arranged on the other end side of the circuit board, and the input part is arranged on the bridge circuit side The output part is disposed on the electrolytic capacitor side,
The input unit and the base are connected by an input power line, the output unit and the LED module are connected by an output power line, and the input power line and the output power line are separated from the circuit board. An LED bulb characterized by that.   The LED light bulb according to claim 1, wherein the input power line and the output power line are disposed on one side of the circuit board.   The LED light bulb according to claim 2, wherein the input power line has higher rigidity than the output power line.

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