Price keeps dropping 2,000 yen LED bulb listed

Around 2000 yen, even cheaper LED bulbs have appeared.

By installing multiple small LEDs to improve heat dissipation, a low-priced resin backplane can be used.

Use a low-cost configuration that takes into account ease of assembly.

In June 2009 , Sharp launched LED bulbs with a price of around 4,000 yen. Companies competed to follow each Other and promoted low prices at one stroke. After just over a December 2009 about half a year, the price is only about 2000 yen LED bulb began to have listed.

One of them is the "Luminous" series (hereinafter referred to as Luminous bulbs) jointly developed by Doosan Electric (Headquarters: Echizen City, Fukui Prefecture) and Doshisha and listed on December 14 , 2009 (Figure 1 ( a )). ). Power consumption is 6.6W , total luminous flux is 420lm (white), equivalent to 60W incandescent lamp is 2480 yen (tax included), consumption is 4.7W , total luminous flux is 310lm (white), The equivalent of a 40W incandescent lamp is priced at 1980 yen (tax included). In addition, on December 22 , Otsuka Chamber of Commerce listed the "Lumidas-CL" series of LED bulbs developed by FAWOO Technology in South Korea for 2380 yen (tax included) (Fig. 1 ( b )). The series includes products that replace 20 to 30W incandescent bulbs with a power consumption of 5W and a total luminous flux of 292lm (white).

In the "Luminous bulbs " jointly developed by Haddon Motor and Doshisha , the price of a 40W incandescent lamp was 1,980 yen, which greatly reduced the price ( a ). The LED bulb "Lumidas-CL" produced by FAWOO Technology, which is marketed by the Osaka Trade Association, is characterized by its elongated shape, which dissipates heat from the inside of the air vent penetrating through the central part of the heat sink ( b ).

Equipped with dozens of LED packages

Critical "to 1980 yen as the goal to promote development" (Doshisha Business omnibus Minister lifestyle lifestyle merchandise, director of the main underground) Luminous light bulb to achieve the low-cost bulb that comes with a lot of small LED package (Figure 2). The equivalent of 60W incandescent lamps is equipped with 40 LED packages, and the equivalent of 40W incandescent lamps is equipped with 34 LED packages.

In the past, many manufacturers used LED packages with input power of 1W in LED bulbs. The Luminous bulb is equipped with a hundred and a few dozen mW LED packages. Although the number of packages that need to be equipped increases, “ the total cost of LED packages is reduced ” ( Doshisha ). However, to install a large number of LED packages, it is difficult to reduce the area of ​​the mounting base plate. In order to make LED light bulbs suitable for existing lighting fixtures, many manufacturers have controlled the diameter of LED bulbs to be less than 60 mm like incandescent bulbs, but Luminous bulbs have increased by 4 mm to 64 mm .

In the equivalent of 60W incandescent lamps, 40 small LED packages are installed. The heat of the mounting base plate can be transmitted to the heat sink via the metal plate.

The use of small LED packages also helps improve heat dissipation. Since the small heat source is dispersed on the LED board, there is no place where the concentration of temperature rises, and the temperature of the board easily becomes uniform.

Luminous bulbs' LED mounting bases use metal baseplates in products that are equivalent to 60W incandescent lamps, and resin baseplates rather than metal baseplates are used in products equivalent to 40W incandescent lamps. "Although the thermal conductivity is relatively good, but not necessary to use the expensive metal plate (with a small amount of the LED package, a small amount of heat) of the product" (Doshisha). The equivalent of a 40W incandescent lamp uses a low-cost substrate that also makes a significant contribution to the price of less than 2,000 yen.

Ring configuration LED

Lumidas-CL also uses a large number of methods with a small LED package just like Luminous bulbs. The number of equipment is 20 . In addition, a low-cost structure that takes into consideration ease of assembly has also been adopted. For example, a snap-fit ​​( SnapFit ) is used in the assembly of the resin case, and the connection between the LED mounting board, the power supply circuit board, and the lamp socket is performed by soldering. Methods. In addition, the Korean LED lighting safety standard certification has been obtained.

A three- layer structure of a lens, a mirror, and a heat sink, respectively, from the outside is used as the hollow shape with a narrowed tip. The LED package is mounted on an annular bottom plate and then mounted at the base of the heat sink.

The appearance of the slender shape is unique, at first glance it will feel that there is no heat sink, but in fact the heat sink is embedded in the central part of the bulb (Figure 3 ). A three- layer structure consisting of a lens, a mirror, and a heat sink, respectively, from the outside is used, and an annular LED mounting base plate is attached to the base of the heat sink (near the base).

The surface of the lens has holes, and air can enter and exit between the through holes in the central part of the heat sink and the outside. In other words, Lumidas-CL employs a structure that dissipates heat from the inside of the through hole of the heat sink. In addition, in order to facilitate the circulation of air, a notch is provided in the bottom plate of the power supply circuit arranged below the heat sink, and a slit is provided in the resin case under the bulb. In this way, air can circulate up and down inside the bulb.