How to Read 0.2x0.2mm Code on The OLED Cover Glass

Since its introduction, OLED (Organic Light Emitting Diode) screen technology for smartphones has attracted significant attention and quickly gained prominence in the mobile industry. Compared to traditional LCD (Liquid Crystal Display), OLED offers higher contrast, faster response times, wider viewing angles, and lower power consumption. OLED screens consist of a series of organic light-emitting materials that emit light and form images when electrically stimulated. Each pixel can emit light independently, allowing OLED screens to achieve true blacks and more vibrant colors.   The development of OLED screens for smartphones can be traced back to early small-sized displays and gradually expanded into the realm of mobile devices. Initially, due to technological limitations and high costs, OLED screens were only used in high-end phones. However, with technological advancements and reduced production costs, OLED screens have become increasingly popular and have become the mainstream choice for mid-range and low-end smartphones.

OLED screens typically consist of the following layers:

• Cover Glass

• Touch Sensor/Barrier Layer

• Encapsulation Glass

• Backplane

However, did you know that some high-end OLED manufacturers require a QR code to be engraved on each component to track and manage the production and assembly process? This QR code contains information about the manufacturer and the manufacturing date. Today, we would like to share a success story of a customer where an OLED manufacturer approached us to provide a reliable decoding solution to read a 0.2mmx0.2mm two dimensional code marked on the OLED cover glass.

Challenge

The size of the 0.2mmx0.2mm two dimensional code is extremely small, making it challenging for conventional code readers and algorithms to capture and decode. Additionally, the two dimensional code is marked on transparent cover glass bu laser printed, and the refraction and reflection of light can reduce the contrast, resulting in blurred boundaries and details of the code.

Project Overview

• Industry: Electronics

• Application: Reading 0.2mmx0.2mm two dimensional code on OLED cover glass

• Challenge: Extermely small size code, transparent cover glass, low contrast

HEROJE Solution

To overcome these challenges, it is necessary to utilize specially designed high-resolution code readers, highly sensitive image processing algorithms, and optical systems, combined with appropriate light sources and contrast enhancement techniques. This combination of technologies can enhance the ability to capture small two dimensional codes, improve decoding accuracy, and enhance resistance to interference, thus achieving reliable reading rates.

For this project, HEROJE developed a customized HRX series fixed-mount intelligent code reader, which plays a crucial role. It integrates AI algorithms, a quad-core processor, high-resolution CMOS sensor, and interchangeable lens design. By pairing it with a 130mm telecentric lens and an external ring light source, the two dimensional codes can be magnified proportionally and the contrast can be enhanced, thereby achieving reliable two dimensional code reading.