Features and applications of OLED display.

- Dec 23, 2019-

Oled display screen is made of organic light-emitting diode (OLED). Because of its excellent characteristics of self-luminous, no backlight source, high contrast, thin thickness, wide angle of view and fast reaction speed, it can be used in flexible panel, wide temperature range, simple structure and process, etc., so it is considered to be a new application technology of the next generation planar display. 

Organic light-emitting diode (oled) displays are becoming more and more common, especially in mobile phones, media players and small entry-level televisions. Unlike standard liquid crystal displays, oled pixels are driven by current sources. To understand how and why the power supply of oled affects the quality of display picture, we must first understand the technology of oled display and the demand of power supply. This paper describes the latest oled display technology, discusses the main power supply demand and solutions, and also introduces the innovative power supply architecture for oled power supply demand. Backplane technology makes soft display high resolution color active matrix organic light emitting diode (amoled) display needs to adopt active matrix backplane, which uses active switch to switch each pixel. 

The amorphous silicon process of liquid crystal (lc) display is mature, which can supply low cost active matrix backplane and can be used in oled.. Many companies are developing an organic thin film transistor (otft) backplane process for soft displays, which can also be used in oled displays to achieve the launch of full-color soft displays. 


                                                                     0.96inch  OLED Display


Both standard and soft oled, need to use the same power supply and driving technology. In order to understand the oled technology, its function and its interaction with the power supply, it is necessary to deeply analyze the technology itself. OLED display is a kind of self-luminous display technology, which does not need any backlight at all. The material used by OLED belongs to the organic material suitable for chemical structure. Oled technology requires that the current control drive method oled has the same electrical characteristics as the standard light-emitting diode (led), and the brightness depends on the led current. To turn on and off oled and control oled current, the control circuit of thin film transistor (tft) is needed. Advanced energy-saving mode can achieve the same maximum efficiency as any battery-powered device, only when the converter operates at the highest efficiency of the overall load current range, which is particularly important for oled displays. 

OLED displays consume the maximum power when they are all white, and the current is relatively small for any other display color, because only white requires all red and green. The blue pixels are all bright. For example, a 2.7-inch display requires 80ma current to present an all-white image, but only 5ma current to display other icons or graphics. Therefore, oled power supply needs to achieve high converter efficiency for all load currents. In order to achieve such efficiency, it is necessary to use advanced energy-saving mode technology to reduce the load current in order to reduce the switching frequency of the converter. Because this is done by voltage controlled vibrator (vco), the possible emi problem can be minimized, and the minimum switching frequency can be controlled outside the audio range of the general 40khz, which can avoid the noise caused by ceramic input or output capacitors. This is particularly important when using such devices in mobile applications and simplifies the design process.