Nowadays we see oled display being used everywhere be it the phones , TVs , laptops or PCs , smartwatches . They sure are better than old chunky CRT TV displays that were bulky and didn’t deliver the desired picture quality , with the introduction of the LCD and backlight LEDs the things sure got better with the chunkiness of the display gone but the picture quality still wasn’t what one desired of but with the release of the OLED display all these problems became a thing of past. OLED or organic light emitting diode were invented in 1987 by Ching Tang and Steven Van Slyke from Kodak but it was until 2004 when SONY released a OLED TV. In fact in CES 2019 , there were some innovative inventions that were released in the OLED domain with the companies trying to come up with foldable display and some exceptional picture quality.
TYPES OF OLED
Passive Matrix Oled (PMOLED)
Pmoleds have strips of cathode , anode and organic layer. The anode strips are perpendicular to cathode strips it is their intersection that makes a pixel . External circuitry applies current to the cathode and anode strips to decide which pixel to light up. They are used in MP3 players , cell phones etc.
Active Matrix Oled(AMOLED)
Amoleds have full layer of anode and cathode and organic molecules . The anode layer overlaps the TFT matrix array . The TFT array is the matrix circuitry that decides which pixel gets turned on form the image. Since they consume less electricity they are used in TV screens , BillBoards, Computer Monitors.
A Transparent Oled has all the components cathode, anode, substrate transparent and when off the display is 85 percent transparent. When switched ON the display allows the transfer of light in both the directions.
Top Emitting Oled
The Top Emitting Oled is have substrate that is either opaque or transparent . They are best suited for active matrix design . They are used in smartcards
They are substrate that made of flexible metallic foil , plastic . They are durable and are easier to replace in case of damage . They are used in smart clothing , GPS receivers , IC computers.
They are made of white light that is more uniform and energy efficient rather than fluorescent lights. They posses true color of incandescent lights
HOW OLEDs WORKS
FIG -1 SIZE OF A SINGLE PIXEL
FIG-2 RGB COLOR FILTERS INSIDE A PIXEL
FIG -3 CONVERTING EACH COLOR INTO BINARY
FIG -4 CROSS SECTION VIEW OF OLED
FIG-5 CHANGING THE ORIENTATION OF THE POLARIZER TO GENERATE DIFFERENT COLORS
FIG -6 ELECTRON HOLE PAIR COMBINATION TO GENERATE LIGHT
FIG – 7 DOPING OF SUBSTRATE TO GENERATE LIGHT OF VARIOUS WAVELENGTH
USE CASES OF OLED DISPLAY
HOW TO CONNECT THE DISPLAY WITH THE MICROCONTROLLER
WE WILL BE COVERING THE DETAILS ON HOW TO CREATE AN EMBEDDED DRIVER FOR THE DISPLAY IN THE NEXT BLOG . IN THIS WE’LL BE COVERING A BRIEF OVERVIEW OF THE 2 METHODS THAT CAN BE USED TO COMMUNICATE WITH THE DISPLAY.
Using I2C we’ll be communicating with the microcontroller by the help of SCL the clock pin that will keep the data transfer in synchronization and SDA the bus on which the data will be communicated.The speed in this case will be less but the no of pins required for communication is less and can be shared by other displays or sensors.
Overview So, hello guys, and welcome back to the Gettobyte Automotive Technology series of blogs. In today’s blog, we are