Note this article is namely written from the perceptive of a PM (passive matrix) OLED display.
Passive matrix OLEDs have been around since the 1980’s and now are considered a mainstream display technology with longer lifetimes, high brightness and lower unit and tooling costs associated with custom displays.
Discussion of the KEY parameters, such as:
- Mono color vs Full Color
- Overall Size: What are your physical limitations that the OLED will need to fit into?
- Resolution: How many pixels per inch do you require?
- Luminance: How bright does it need to be?
All these parameters can and will affect the price the OLED display, so understanding what you need can save you time and money.
Mono or Full Color
When you have decided that an OLED display is the right choice for your project, with it’s offering of a high contrast ratio, brightness and resolution, the next step is to decide whether mono color or multicolor will be needed.
If you selected mono color, note, that many OLED offer grayscale. What does that mean? Basically, it’s the variations from WHITE to BLACK in several levels. Typically, from 2 levels (WHITE(ON) /BLACK (OFF) through 16 levels, providing various shades of gray tones. Similarly, if you determine a full color display is needed, there are various amounts of colors offered, typically from 64k colors to 265k colors.
Size
The two sizes to most be concerned with, are the active area size and the panel size. The active area is the portion of the display that contains the pixels that will light to show your image. Panel size is the overall physical size that will be needed to fit within your product. In an OLED display, there typically is a border between the edge of the glass panel and the active area. This border is needed for the internal wiring for each of the pixels along with possibly mounting of the driver IC that controls the current to the pixels.
Resolution
This term indicated the size of the pixels. The smaller the individual pixel size, the higher the resolution of the display. How much resolution you may need will depend on what you actually want to show on the display. For example, if you want to show icons or symbols and fairly minimal text, you may only require low resolution, but if you plan to show video images or fairly intricate graphics with gray scale, you will need a higher resolution capability.
Luminance
Luminance or brightness, is sometimes the hardest parameter to quantify in the initial stages of product development. Since the OLED’s luminance comes from the type of organic material along with other structure elements, its important to share your application with the OLED supplier so they can guide you. In some cases, OLED suppliers can send you a standalone demo of the OLED being operated to its specifications. One example of understanding how much luminance you will need out of the display, is to indemnity if the OLED is going into a product that’s primary use is indoor or outdoor. Outdoor applications will require the luminance to be quite high to overcome the brightness of the sun without this consideration, the display may be unreadable.
Cost
All of the key parameters I have listed above, will impact the OLED display’s price. Most OLED suppliers can work with you to find a happy medium between what you need and what you can spend on the display.