Samsung struggles to develop QD display
By Lee Jong-joon Approval 2020.02.10 16:06
After ordering inkjet printing equipment to Semes,
continue to test blue OLED light source stack
Samsung Display has been struggling to develop the quantum dot (QD) display, which is being prepared for next year, until recently. The final decision is still to be made on the key specifications of the QD inkjet printing equipment and the large blue organic light emitting diode (OLED) device configuration.
Semes, which won an order for inkjet printing equipment for QD display pixel processing, is adjusting key specifications of the equipment. Samsung Display decided to receive all of its inkjet printing equipment from Samsung Electronics' subsidiary, Semes. The decision was made after evaluating both the inkjet printing equipment of Catiba, USA, which is considered as the leader in Semes and inkjet printing equipment.
However, after several weeks of equipment development, there was a problem of clogged inkjet printing nozzles. Semes plans to complete the adjustment of inkjet printing equipment specifications this month to resolve the nozzle clogging. Samsung Display has been testing inkjet printing equipment at Semes since the end of 2018.
An official in the equipment industry said, "There was no big problem when we were evaluated with Cativa." "Samsung Display seems to have changed the QD ink after selecting the equipment." "After changing QD ink, the problem-solving process will be a barrier to competitors."
The industry believes that it will be decided in the first half of this year how many layers (stack, stack) of blue OLED light sources, which are considered core technologies, together with inkjet printing equipment. A senior official from the material company said, "We are testing from 2 stacks to 4 stacks with 3 stacks as a base." "Brightness and production cost will be considered comprehensively."
QD displays use blue light from OLED devices as a light source. Blue light is converted from QD pixels (light conversion) to red or green. The converted red (R), green (G) and blue (B) of the existing light source are combined to form an RGB subpixel. In this process, the brightness of the light source gradually decreases.
The more blue OLED stacks are stacked, the higher the brightness and lifespan will be, but the production cost will increase. At CES 2020 this year, Samsung Display exhibited a sample of 4K resolution 65-inch QD display. At that time, there was an evaluation that the black expression appeared a little, and it was interpreted that the circular polarizer for OLED was not attached because of the brightness.
The circular polarizer for OLED greatly reduces the reflected light caused by external light, but also reduces the brightness of the internal display. An official in the field of display said, “It is difficult to produce black light when using a self-luminous device. If it is turned off, it is most likely due to reflection by external light.”
www.thelec.kr/news/articleView.html?idxno=4964 Text zur Anzeige gekürzt. Gesamten Beitrag anzeigen »