Using a liquid crystal light guide plate LED lighting, Hitachi lighting will launch new products

Figure 1: the LED lighting device

Hitachi lighting has developed a linear white LED lighting apparatus "LINESABER", will begin shipping from July 2008 (Figure 1). The luminous flux is 140lm when the rated input power is 7W and the rated input power is 5W 70lm. Through the application of liquid crystal panel backlight light guide plate technology used to be able to line a ray of uniform radiation. Compared with the fluorescent lamp, the utility model has the advantages of lower power consumption and smaller size. The company said, lighting apparatus using 10W fluorescent lamp at rated input power to average illuminance under 13W 199lx, and LINESABER 7W can obtain 208lx input average illumination, thus the power consumption reduced by about 1/2 (the distance from the source location, the illumination is 50cm the average 40cm value of the square area) (Figure 2).

Figure 2: comparison with fluorescent lamps

The external dimensions of LINESABER are 300mm * 16.8mm * 16.3mm. Compared with the use of fluorescent lamp, the packaging area reduced to about 1/3, height reduced to about 1/5, volume reduced to about 1/18. Rated life of 40 thousand hours, for the use of the same fluorescent lighting products of about 7 times. The utility model is mainly used for lighting lamps and lanterns, etc., which are mainly used for the irradiation of goods, etc., and a lighting device which is arranged on the steps and handrails, and is used in the place of the characteristics of the small shell.

Suggested retail price, 7W products for 27 thousand and 300 yen, 5W products for the yen of 24 thousand and 150. The price includes a circuit module for driving an LED illuminator with an AC power supply. Ordinary white light products for standard products, but also can be produced by a single increase in the color temperature of the day after the light color products and improve the red after the warm white products.

Use the light guide plate to solve all the problems

Figure 3: light guide plate structure

LINESABER biggest feature in technology is: both ends of the shell or end with white LED, the light emitted from the light guide plate will even spread to the entire surface of the shell, in order to make the light emitted and change the optical path from the surface of the shell (Fig. 3). The original linear LED lighting fixtures to arrange a number of white LED. Therefore, although it is linear but white LED is very obvious, it appears to be "a grain of a", it is difficult to equal irradiation, but also vulnerable to the white LED between the brightness and the impact of uneven color (Figure 4). Although the narrow spacing of white LED can alleviate these phenomena, but this will increase the cost of parts. The company said that by the end of the configuration of the white LED, the use of light guide plate homogeneous diffusion method can solve the problem.

Figure 4: the upper side of the original linear LED lighting appliances, the lower side of the product

In addition, the white LED packaging method which is arranged on the end face of the utility model has been put into operation, and the utility model has the advantages of high efficiency radiating to the metal shell. Specifically, the first is called the Heat Block object on the packaging of white LED, and then Heat Block embedded in the inner side of the metal shell (Figure 5). The heat dissipation area is enlarged by this method.

Figure 5: heat dissipation structure

Back to the LED lighting equipment equipped with white LED for the input power of 2.5W products. Hitachi Lighting is used from the general LED manufacturers to purchase products in the United States, estimated by the United States Philips Lumileds Lighting production. Hitachi Lighting said, LINESABER can be equipped with a number of manufacturers of white LED.

08 year will also add 1200mm products

Figure 6: products in development. Side for 1200mm products

Hitachi Lighting in the future will also change the length of the product line of additional products, and the product can change the light color. Online long term, the company is developing 600 ~ 1200mm products (Figure 6). When the line length is less than 600mm, the method can only be used to configure the white LED on one end face. Line less than 1200mm products can be used at both ends of the configuration of the white LED method. Change the color of the product will be equipped with the end of the red LED, green LED, blue LED integrated into a module LED. These products are scheduled to be listed in 2008.

Figure 7: trial produced LED package

For the red, green and blue LED is integrated into a module of LED, the Hitachi Lighting is the independent development of packaging technology. Intends to buy from the outside vendor LED chip packaging. The reason is to enter the LED chip 2W power, the need for low thermal resistance of the package. Has been developed to complete the thermal resistance of 4.5 /W package, the program eventually fell to /W () figure 7. The company said it has achieved success in achieving thermal resistance at 2.5 /W. It also said that the use of the white LED thermal resistance is about 8 /W.

Source: Nikkei BP