(Passive-Matrix Organic Light Emitting Diode).
Passive-Matrix OLED Displays are named by the passive drive construction for each pixel. The pixels illuminate with a row & column provide the necessary voltage differential and sufficient current to drive the pixel to illuminate. For a flat panel display with a resolution such as 128x64 pixels, this will require the display driver to multiplex both the logic and power both through the embedded display driver IC. The power will cycle and scan through all rows & columns with normal refresh frequency. This display is suitble for stable industrial products requiring small format displays under 3 inch diagonals. The resolution must be limited since power scales with size in a PMOLED drive system. This impacts the usable life of the PMOLED Display. For this reason, the focus of production is on smaller sizes and more modest resolutions. You will encouter these in various products like activity tracker wearables in the market. The displays are stable and offer industrial support.
The conceptual technology behind OLED displays originates back into the 1950's and 1960's. Original patents arrived in the mid 1970's and the first practical implementation in the late 1980's. The original 'large molecule' technology was the first to debut in production from Eastman Kodak. Later in the 1990's 'small molecule' technologies reached the market from Pioneer, TDK, and Samsung. The primary differences in the 'large' versus 'small' technologies is the manufacturing , patents, and other related processes.
PMOLED Displays have a number of advantages. The materials for making PMOLED require less overall materails than similar liquid crystal display (LCD) materials. Less materials provides the premise of lower material costs if equal demand and yield is acheived. Less materials also makes the displays thinner and lighter weight potentially than many simliar LCD dispalys with backlights. PMOLED displays are solid-state display technology, so the electrical, mechanical, and optical performance does not differ over fluctuation within the operating temperature range specified in the item.
Limiting factors for PMOLED Technology include sunlight performance which is difficult for any emissive display to compete with high intensity sunlight. The technology is suitable for some sunlight conditions, but under extensive sun it may be subjectively not compare well on this category. Displays that generate light will draw more power than some technologies that do not produce light through a backlight, such as reflective displays that utilize ambient lighting. PMOLED will not be able to be reflective in polarization, so compared to those technologies it will draw more power by comparision. PMOLED can be optimized to illuminate less pixels of the display to draw less power. The power is proportional to the number of illuminated pixels. On a color PMOLED offering, full "WHITE" emission will draw the most power with all red, green, and blue sub-pixels running at full intensity.
PMOLED Displays are able to claim industrial availablity and customization discussions for a reasonable cost within the industry and compared to other display technologies. The production lines making PMOLED offerings are smaller generation glass lines similar to those that make LCD or Glass-Glass Projective Capacitive Touch sensors. So, the capacity is availbale and stable. Due to these glass lines smaller generation substrate size and that the display drivers multiplex the power, it is ideal for the technology to focus on smaller sizes such as 0.4" to 3" digaonal size and maintain lower pixel resolutions. Higher resolution content and larger sizes benefit from Active-Matrix OLED Displays (AMOLED) which seperates out the power from the logic using thin film transistor construction. This is more efficient and stable for power supply to each pixel than multiplexed through the display driver with a duty cycle.