R&D and TECHNICAL SUPPORT ENGINEER
OLED (Organic Light Emitting Diode) is a technology offered as an alternative to LCDs. OLEDs are organic as they have a structure consisting of carbon and hydrogen. OLED LCDs don’t need a backlight. Each pixel can provide its own illumination. In other words, OLEDs use pixels with independent illumination, while LCDs have to use a background illumination. Since each pixel of the OLED LCDs has its own light source, it allows the image to appear at a much higher brightness when compared to normal LCDs. There is no need for hardware based contrast adjustment in OLEDs. The contrast of an LCD, whose contrast is adjusted in hardware with resistors, may deteriorate over time depending on the conditions of use. However, this doesn’t apply with OLEDs as their contrast is adjusted in software. OLED LCDs can be monochrome or multicolor. Monochrome OLED LCDs are called “passive matrix OLED” (PMOLED), and multicolor OLED LCDs are called “active matrix OLED” (AMOLED). OLED LCDs consume much lower power than regular LCDs. Backlight lighting on LCDs will provide maximum power consumption regardless of the image on the screen, but it is more efficient in terms of energy saving as it illuminates only the pixels that need to be used on an OLED LCD screen. That said, OLED LCDs are lighter than regular LCDs and have a minimum viewing angle of up to 160 degrees. OLED LCDs, which can usually operate in a wide temperature range from -40 degrees to +70 degrees, have a minimum service life of 50,000 hours. The areas of use of OLED LCDs are quite wide. They are used in many fields from automobile indicators to mobile phones, from medical devices to white goods or automation products, and include dynamic information screens.
“The contrast of an LCD, whose contrast is adjusted in hardware with resistors, may deteriorate over time depending on the conditions of use. However, this doesn’t apply with OLEDs as their contrast is adjusted in software.”
According to the graphics structure, OLED LCDs are divided into two. These are “character OLED LCDs” and “graphic OLED LCDs”. Winstar character OLED LCDs in Ozdisan Elektronik inventory are available in 2×8, 2×16, 4×20 sizes. For instance, a 2×16 OLED LCD has 2 rows and 16 columns. The characters in the control integration of the OLED LCD can be written to each of these rows and columns. According to the graphics structure, another type of OLED LCD is graphic OLED LCDs. Each pixel of the graphic OLED LCD can be controlled by the processor. In this way, any desired visual can be created on the OLED LCD screen. Graphic OLED LCDs can be in various pixels like 128×32, 128×64, 96×64, 128×32. For instance, a 128×64 OLED LCD has 128 pixels horizontally and 64 pixels vertically. OLED LCDs, which usually operate between 3V and 5V voltage values, can be in various colors like red, white, blue, green and amber. They can also be in more than one color on a single screen. There are also OLED LCDs with touch screen feature. The communication method used in OLED LCDs is parallel, spi or i2c. According to their physical structure, OLED LCDs are divided into three: COB (Chip On Board), COG (Chip On Glass) and COF (Chip On Flex or TAB). The chip and all the materials of a COB type OLED LCD are located on the PCB under the LCD glass. A user using a COB OLED LCD does not need to connect any external electronic components. The chip of the COG OLED LCDs is mounted on the LCD glass. All the electronic components needed by a user who uses a COG OLED LCD must be connected by the user from the outside. Even though the logic operating voltage of COG type OLED LCDs is, for instance 3V, the display operating voltage is at higher voltages, for instance 12V-13V. Therefore, LCD display driver integrations must be used. The chip of an OLED LCD with a COF or TAB physical structure is mounted on a flex cable. Some electronic components are also located on this flex cable.
