For Oppo Glass,Oppo Find X3 Front Glass,Oppo Phone Screen Glass,Oppo Reno 5 Pro Glass Dongguan Jili Electronic Technology Co., Ltd. , https://www.jlglassoca.com
Japan's important flat panel exhibitions "FPD International 2009" and "Green Device 2009" were held at the Pacific Yokohama Convention and Exhibition Center from October 28 to 30, 2009. The hot spots displayed in these two exhibitions are also the products of the LED chips jointly displayed, which are LED backlights and LED lights for LCD TVs.
Korean manufacturers have actively promoted the thinning of LCD TVs by using LED backlights. This time, at the Samsung Electronics booth in South Korea, the 3.9mm thick "world's thinnest" (the company) 40 using edge-lit LED backlights was exhibited. panel.
In the United States and other places, LCD TVs using LED backlights have formed a market, Samsung Electronics currently holds about 90% of the global LED backlight market in the LCD TV market.
At the "FPD International 2009 Forum" seminar held at the same time, Samsung Electronics Tae Seok Jang (Deputy President of Component Solutions Business Unit of LCD Division) predicted that the LED backlight LCD TV market will achieve leap-forward development in the future. The annual output of 3.7 million units, 30 million units in 2010 and 68 million units in 2011 accounted for about 40% of the LCD TV market. The 2007 forecast suggests that such TVs accounted for 10% of the market in 2011.
With the development of the trend of thin-film LCD TVs, LED backlights have been fully adopted, and sales have gradually expanded. At present, in order to reduce the number of LED chips used in LED backlight sources, the use of edge-emitting type has an increasing trend, but this type has a problem of local dimming.
In addition, a light guide plate must be used to achieve a thinner backlight. Its function is to evenly distribute the LED light at one end to the entire backlight. That is to say, reducing the number of LED chips requires the addition of a light guide plate.
Transition to direct type
Due to the difficulty of local dimming and the high price of the light guide plate, the relevant person predicts that "the direct-type backlight that is placed directly below the screen will become the mainstream." Although the direct type is not conducive to thinning, local dimming can be realized as described above, thereby improving the image quality of the image displayed on the liquid crystal panel. Moreover, it is not necessary to use a relatively expensive light guide plate and microlens.
The premise of the transition to the direct type is the significant price reduction of LED chips. The reason why the edge-emitting type is widely used is that the direct type requires a large number of LED chips. If the output of the LED chip can surpass the past and the unit price of the chip is lowered, the direct type using multiple diffusing plates is more favorable for lowering the price than the edge emitting type using the light guide plate.
The low price dynamics of LED chips have become increasingly apparent. According to the prediction of university professors in the field of liquid crystal in Korea, "Samsung Electronics has begun to purchase MOCVD devices, and the number may be more than 200." In this regard, Samsung Electronics insiders did not disclose the detailed quantity, but did not deny that it will be transferred to mass production of LED chips: "With regard to MOCVD devices, we are adjusting the semiconductor technician configuration to enable the device to meet the market 2 to 3 years later. Prepare for demand."
In addition, in February 2009, Veeco Instruments announced the decision to supply LG Innotek with MOCVD devices for high-brightness LED manufacturing. Regarding the number of purchases, the university professor in the field of liquid crystal in Korea said: "There may be more than 100 units now."
For Taiwanese manufacturers, AU Optronics (AUO) purchased MOCVD devices for Lextar, the company's LED manufacturer. AUO also announced in the 2008 SID keynote speech: "Replace all notebook backlights to LEDs by 2011."
But even if the LED chip is reduced, the direct-type backlight still has a problem. An increase in the number of LED chips will change the mounting base plate and structure, resulting in an inverse increase in weight and thickness. Even if the thinning and energy saving are achieved, it is difficult to ensure "easy wall hanging" by increasing the weight of the product. Moreover, the difficulty of thinning is higher than that of the edge-emitting type.
For the above problem, the COB (chip on board) for mounting the LED chip directly on the printed substrate is more effective than the method in which the LED package is mounted on the printed substrate. The COB can arrange a large number of LED chips at small intervals, so that a single LED emits light closer to the surface light, which contributes to the thinning of the backlight. At this stage, this method is estimated to be the object of research by companies.
Synergistic effect of LEDs for backlights and LEDs for lighting
In addition, the above-mentioned LED manufacturers and panel manufacturers purchase MOCVD devices in large quantities in order not to simply increase the output of LED chips for backlights. It also shows great expectations for expanding the LED lighting market.
Today, the global lighting market is about 7 trillion yen. At the "Green Device 2009" seminar, the former Yamaguchi of the Nomura Research Institute said that as of 2009, the LED lighting market is about 150 billion yen, and will increase to about 500 billion yen in the next three years.
Although the LEDs for backlights and the LEDs for lighting are not the same, it can be said that Korean manufacturers are still working hard to apply the high-brightness technology developed for LEDs for backlights to LEDs for lighting, and expect them to work synergistically. effect. 