How is the transmittance of an open frame touch monitor measured?
Release Time : 2025-12-01
Light transmittance is a core indicator of the optical performance of an open-frame touch monitor, directly determining the screen's clarity, color reproduction, and user visual comfort. Essentially, light transmittance is the ability of light to pass through a medium, specifically expressed as the percentage of luminous flux transmitted through a transparent or translucent body compared to the incident luminous flux. For open-frame touch monitors, this indicator is not only affected by material properties but also closely related to structural design, coating processes, and environmental adaptability, requiring comprehensive multi-dimensional evaluation to ensure performance meets standards.
From a materials perspective, open-frame touch monitors typically consist of multiple layers, including a glass cover, a touch layer, and a display module. The material and processing technology of the glass cover significantly impact light transmittance. For example, using high-purity optical glass combined with ion-exchange strengthening technology can reduce light absorption while maintaining structural strength; while the optical anti-reflective film deposited on the surface can reduce reflectivity through interference principles, further improving light transmission efficiency. The choice of materials for the touch layer is equally crucial. For capacitive touch modules using transparent conductive oxides (such as ITO) or metal mesh technology, a balance between conductivity and light transmittance must be struck to avoid light scattering or absorption due to excessively thick film layers or high mesh density.
Coating processes are another important means of optimizing light transmittance. Open-frame touch monitors often need to cope with strong light environments, so their surfaces are coated with anti-reflective (AR) and anti-glare (AG) films. The AR film uses a multi-layer optical film design to cancel out reflected light, thereby reducing interface reflection loss; the AG film uses microstructures to scatter surface light, avoiding glare interference caused by specular reflection. The synergistic effect of these two coatings significantly improves the readability of the display under complex lighting conditions while maintaining high light transmittance. Furthermore, some high-end products employ nanoscale coating technology to further refine optical path control, achieving dual optimization of light transmittance and visual comfort.
The impact of structural design on light transmittance is also significant. Open-frame designs typically need to balance heat dissipation, electromagnetic shielding, and optical performance, thus requiring precise optical simulation to optimize the internal structure. For example, reducing unnecessary metal bracket obstruction, adopting a narrow bezel design to expand the viewing area, and reducing interlayer interface reflection through air layers or optical adhesive filling can all effectively improve light transmission efficiency. Furthermore, modular design must ensure optical compatibility between components to avoid light deflection or absorption due to assembly errors, thereby maintaining the stability of overall light transmittance.
Environmental adaptability is a crucial dimension for measuring the light transmittance of an open frame touch monitor. In real-world use, monitors may face extreme environments such as high temperature, high humidity, and salt spray. These factors can lead to material aging, coating peeling, or structural deformation, thus affecting light transmittance. Therefore, environmental testing is necessary to verify its long-term stability. For example, damp heat testing can detect whether the coating blisters or peels off in high humidity environments, while thermal cycling testing can assess the impact of temperature changes on material transmittance. Only products that pass rigorous environmental testing can ensure consistently high light transmittance display performance in complex application scenarios.
Light transmittance measurement requires specialized equipment and standardized procedures. A spectrophotometer is a universally used measurement tool in the industry. It accurately calculates transmittance by emitting light of a specific wavelength and detecting the intensity of the light after it penetrates the sample. During testing, variables such as ambient light and the angle of incidence must be strictly controlled to ensure data accuracy. Furthermore, indicators such as brightness uniformity and color uniformity must be considered to comprehensively evaluate the optical performance of the display. For example, if the transmittance of a particular area of the screen is too low, it may lead to uneven brightness or color difference, affecting the user experience.
The transmittance of an open frame touch monitor needs to be comprehensively evaluated from multiple dimensions, including materials, coatings, structure, environmental adaptability, and measurement methods. By optimizing material selection, coating processes, and structural design, and through rigorous environmental testing and precise measurement, the monitor can maintain high transmittance while also ensuring durability and visual comfort, thus meeting the needs of high-end applications such as industrial control, medical equipment, and public information displays.
