Transmittance is a metric measuring the residual intensity of light after passing through a touchscreen, expressed as a percentage. A higher value indicates better light transmission, resulting in brighter and clearer display images.
1. Basic Range of Touchscreen Transmittance
Influenced by factors such as materials, manufacturing processes, and design, touchscreen transmittance typically ranges between 70% and 95%. Significant variations in light transmission performance exist across different screen types and structures.
Resistive Touchscreens
As an early technology, resistive screens rely on pressure sensing for operation. Their relatively simple structure generally achieves transmittance above 80%. However, they exhibit limitations in multi-touch capabilities and responsiveness, leading to gradual replacement by capacitive screens.
Capacitive Touchscreens
One of the current mainstream touch technologies, capacitive screens detect touch by sensing the human body's electric field. They offer advantages such as fast response times and support for multi-touch. Their light transmittance generally ranges between 85% and 92%, with specific performance influenced by thickness, coating, and manufacturing processes.
OLED Transparent Touchscreens
As an emerging technology, OLED screens possess self-emissive properties, achieving light transmittance exceeding 70% while delivering high-contrast displays. They clearly reveal background objects in commercial displays and similar scenarios, offering outstanding visual effects.
Other Touchscreen Types
Infrared and ultrasonic touchscreens typically have light transmittance between 70% and 90%, with specific values influenced by sensor layout and operating principles.
2. Key Factors Affecting Light Transmittance
Materials
Glass offers high light transmittance and hardness but carries higher costs; plastics are cost-effective yet exhibit weaker light transmission and hardness; film materials are lightweight and flexible, though their light transmission performance represents a compromise.
Processing and Design
Surface coatings, film deposition techniques, and screen thickness control all impact light transmission. Superior manufacturing processes minimize light loss. Additionally, design factors like bezel width and screen size alter the path and area of light transmission.
Operating Environment
Temperature, humidity, and lighting conditions may temporarily affect transmittance—e.g., material expansion at high temperatures or surface condensation due to moisture.
3. Feasible Methods to Enhance Light Transmission
Select high-transmittance materials, such as optical-grade glass or high-transmittance plastics;
Optimize coating and film deposition processes to enhance surface light transmission;
Rationally design screen structure and dimensions to improve light incidence and exit paths;
Control ambient temperature and humidity to prevent external conditions from interfering with screen performance.
Transmittance is a critical parameter determining touchscreen display quality. Screens employing different technological approaches exhibit distinct characteristics in light transmission performance. Through material optimization, process upgrades, and structural refinements, transmittance can be effectively enhanced, thereby improving the visual experience. With ongoing technological advancements, the light transmission capabilities of future touchscreens are expected to continue improving, delivering greater enhancements to the display performance of electronic devices.