How to Find the Right OLED Display in Our Offer?

When choosing an OLED display, it is important to pay attention to several parameters such as color of content, module type, voltage, and operating temperature. Below, we describe selected parameters of OLED displays.

OLED Display Colors

Monochromatic OLED displays dominate Unisystem's offer, featuring diodes in a single color, such as white, yellow, red, green, or blue (which defines the color of the displayed content). Monochromatic OLED displays can also combine different colors, resulting in a matrix composed of diodes in, for example, yellow and blue colors, allowing the creation of vertical or horizontal stripes in yellow and blue. In consumer applications, color OLED displays are commonly used. These displays use pixels composed of three sub-pixels—red, green, and blue (RGB model)—which, when combined, create different shades of colors. Such matrices are referred to as RGB OLED displays. Another variant is RGBW OLED (also known as White OLED). In RGBW OLED displays, each pixel consists of four sub-pixels—one for each primary color and an additional white sub-pixel. This modification significantly improves color reproduction quality.

Types of OLED Display Modules

OLED displays can be classified into three structural variants:

• COG (Chip-on-Glass) - with OLED diodes placed on the display glass. The COG variant is used when a smaller number of OLED diodes is needed but with higher image quality and smaller module size.
• COB (Chip-on-Board) - with OLED diodes placed on a PCB. The COB variant is used when a large number of OLED diodes are needed, or in applications where low production costs are a key requirement.
• COF (Chip-on-Film) - with OLED diodes placed on a flexible film. The COF variant provides better image quality and advanced features, which are particularly important in industrial applications.

Interfaces Used in OLED Displays

One of the factors in choosing the right OLED display is the interface, which determines how it communicates with the controlling device. Popular interfaces used in OLED displays include 6800 and 8080, CAN, I2C, and SPI. The 6800 interface is one of the oldest types and uses eight wires to transmit control signals and data. The 8080 interface is an advanced version of the 6800 interface and utilizes 16 wires, allowing for faster and more advanced communication. The CAN interface is a multi-master solution without a central unit. In this network, all devices monitor the network continuously and wait for an opportunity to transmit their own message. Data reaches all devices in the network while maintaining a specific order defined by unique identifiers assigned to each message (determining its priority). The I2C interface is a serial solution in which communication occurs bidirectionally. It is a multi-master bus, and information is transmitted in the form of one-byte packets. Each transmission has a designated start (START signal/bit) and end (STOP signal/bit). Between them, the master device sends a 7-bit address and then the read/write bits and relevant data to the target device. The SPI interface is a serial solution in which communication occurs bidirectionally. It is based on the "master/slave" model, although it is not a multi-master bus. Typically, only one master device is used, connected to several slave devices. Four lines are used for transmitting information. Learn more about the interfaces used for data transmission from our guides - part 1 and part 2.

Voltage in OLED Displays

The operating voltage in monochrome OLED displays is commonly defined at 3V, 3.3V, or 5V. In applications utilizing OLED solutions, it is important for the supply voltage to be precisely matched to the end device. Any changes in the voltage path require the use of additional electronic components, resulting in design modifications and affecting the final production cost of the device.

Operating Temperature of OLED Displays

Among the available display technologies on the market, OLED displays stand out for their wide operating temperature range (for almost all models, the operating temperature range is specified from -40 to 80°C). This allows them to be used in extremely low and high temperatures without the need for additional elements like fans or heaters.