会社のニュース Monochrome PMOLED in Sunlight: White, Blue, Yellow, or Green – Which Performs Best for Industrial HMIs?

Introduction

For engineers designing industrial human-machine interfaces (HMIs), outdoor equipment, or portable devices, display readability under bright sunlight is a critical challenge. Monochrome PMOLEDs offer excellent contrast and low power consumption, but color selection significantly impacts visibility in high-ambient-light conditions. This article explores the visual performance of white, blue, yellow, and green monochrome OLEDs in sunlight, backed by optical science and real-world application insights.

The Science of Sunlight Readability

Sunlight contains broad-spectrum visible light, which can wash out displays through reflection and glare. Readability depends on:

1. Luminance Contrast: The difference between emitted light and reflected ambient light.

2. Spectral Sensitivity: The human eye’s sensitivity to wavelengths under varying lighting.

3. Color Perception: Psychological and physiological responses to different hues.

According to CIE 1931 color space studies, the human eye peaks in sensitivity at 555 nm (green-yellow) under photopic (daylight) conditions. This explains why certain colors perform better outdoors.

Comparing Monochrome OLED Colors in Sunlight

Based on the SFOM312YZ7-25664WBYG-01 specifications—which offers white, blue, yellow, and green color options—here’s how each performs:

1. Yellow PMOLED

• Wavelength Range: ~570–590 nm, close to peak daylight sensitivity.

• Advantages: High perceived brightness, reduced eye strain, and excellent contrast against blue skies or natural backgrounds.

• Best For: Automotive dashboards, marine instruments, and outdoor metering devices.

2. Green PMOLED

• Wavelength: ~520–560 nm, also near peak photopic sensitivity.

• Advantages: Energy-efficient, high luminance with lower current draw, and strong contrast in most environments.

• Best For: Medical devices, industrial controllers, and battery-powered portable tools.

3. Blue PMOLED

• Wavelength: ~450–495 nm, shorter wavelength, lower photopic sensitivity.

• Challenges: Requires higher luminance to achieve similar perceived brightness, may appear dimmer in direct sunlight.

• Best For: Indoor or low-ambient-light aesthetic applications.

4. White PMOLED

• Broad Spectrum: Mimics full-spectrum light, but can blend with ambient white light.

• Considerations: Offers neutral aesthetics but may require higher brightness settings outdoors, impacting power efficiency.

• Best For: General-purpose HMIs where color consistency is key.

How Saef Technology Limited’s 3.12-inch PMOLED Optimizes Sunlight Readability

The SFOM312YZ7-25664WBYG-01 from Saef Technology Limited is engineered for challenging environments:

• High Luminance: Typical 140 cd/m² (up to 170 cd/m² customizable) ensures visibility even under 10,000 lux sunlight.

• 16 Gray Scales: Enables subtle contrast adjustments to combat glare.

• Wide Viewing Angle (160°): Consistent readability from multiple orientations.

• Robust Design: Operating temperature range of -40°C to +80°C suits outdoor and industrial use.

Enhancing HMI Design with Integrated Touch Solutions

While the base PMOLED module is display-only, Saef Technology Limited offers customizable touch screen overlays (CTP/RTP) to create fully interactive HMIs. For sunlight-readable touch interfaces, we recommend:

• Matte or Anti-Glare Touch Overlays: Reduce reflections without compromising touch sensitivity.

• High-Brightness Backing: Pair with yellow or green PMOLEDs for optimal outdoor usability.

• Sealed Solutions: IP-rated integration for dust- and moisture-prone environments.

Practical Recommendations for Engineers

1. Prioritize Yellow or Green for high-ambient-light applications to leverage human visual sensitivity.

2. Adjust Contrast via SSD1322 Driver IC: Use the built-in 256-step contrast control (Command C1h) to fine-tune for lighting conditions.

3. Consider Optical Bonding: Reduce internal reflections by bonding the PMOLED to a touch panel or cover lens.

4. Test in Real Conditions: Validate with ambient light sensors or under simulated sunlight (10,000+ lux).

Conclusion

For industrial HMIs exposed to sunlight, yellow or green monochrome PMOLEDs provide superior readability due to their alignment with human photopic response. The 3.12-inch SFOM312YZ7-25664WBYG-01 from Saef Technology Limited delivers these color options alongside high brightness, wide temperature tolerance, and customizable touch integration—making it an ideal choice for rugged, outdoor-capable designs.

Ready to optimize your display for sunlight readability? Contact our engineering team for tailored PMOLED and touch screen solutions.

Call to Action:
Explore the full specifications of the SFOM312YZ7-25664WBYG-01 Specification.pdf PMOLED or request a sunlight-readability sample kit via www.saefdisplay.com.