Today, touch panels are widely used in our daily lives, everywhere from smart homes, medical devices to industrial control equipment. The light transmission of a touch screen, as one of the most important parameters for measuring its performance, directly affects the user experience and the overall performance of the device.
Light transmittance is the percentage of the amount of light penetrating into the touch screen versus the amount of ambient light. It is a physical measure of the ability of light through the medium, taking the value range of 0 to 100%. The higher the transmittance, the better the light transmission of the touch screen, and the clearer the visual effect. However, due to light reflection, light absorption, light scattering and other factors, the light transmission rate of any transparent material can not reach 100%, the current highest light transmission rate is only about 95%.
1. Transmittance is affected by a variety of factors, mainly including the material, structure, manufacturing process and environmental factors of the touch screen. The following is a detailed introduction of some of the main influencing factors:
1.1 Material Selection: The substrate and conductive coating material of the touch screen have a direct impact on the light transmittance. For example, glass is a high light transmittance material, but when the light passes through, it will lose part of the light due to reflection and scattering. In addition, the thickness, uniformity, and transparency of the conductive coating also affects light transmission.
1.2. structural design: the structural design of the touch screen is also an important factor affecting the light transmittance. Although the multi-layer composite film structure improves the durability and sensitivity of the touch screen, but may also lead to a decrease in light transmission. Therefore, the structural design needs to weigh a variety of factors to find the optimal balance between light transmission and performance.
1.3. Manufacturing process: The manufacturing process of the touch screen, such as the way the coating is applied, curing temperature and time, etc., will have an impact on the light transmittance. Fine manufacturing process can ensure that the conductive coating is uniform, thin and transparent, thus improving the light transmission rate.
1.4. Screen surface treatment: anti-glare, anti-reflection and other treatment technologies on the surface of the touch screen can reduce the reflection and scattering of light on the surface of the screen, thereby improving light transmission.
2. The mainstream touch screen types on the market today include resistive touch screen, capacitive touch screen, surface acoustic wave touch screen and infrared touch screen. Their light transmittance varies, the following will be introduced separately:
2.1. resistive touch screen: resistive touch screen usually has a multi-layer structure, including the base layer, conductive layer and protective layer. Since these additional layers increase the reflection and scattering of light, the light transmission rate of resistive touch screens is relatively low. A typical resistive screen has a light transmission of about 75%.
2.2. Capacitive Touch Screen: Capacitive touch screens usually use glass as the substrate and a transparent conductive coating on its surface. Compared to resistive touch screens, capacitive touch screens have a higher light transmission rate. A new generation of capacitive touchscreens can have a light transmission rate of 91.5% or higher. However, it should be noted that some businesses may exaggerate their light transmission data, so consumers need to be careful to identify when buying.
2.3. Infrared touch screen: Infrared touch screen detects and localizes the user's touch by means of a matrix of infrared rays densely distributed in the X and Y directions. Since infrared rays have little effect on light transmission, infrared touch panels have a relatively high light transmission rate. However, the resolution and stability of infrared touch screen may be affected by ambient light and interference.
2.4. Surface Acoustic Wave Touch Screen: Surface Acoustic Wave Touch Screen utilizes the principle that ultrasonic waves propagate on the surface of the touch screen when they are interfered by the touch to realize the touch function. Its structure includes the transmitter, receiver and touch screen surface. Due to the relatively simple structure and no conductive layer, surface acoustic wave touch screen light transmission is usually high, can reach more than 92%.
3. As one of the important performance indicators of the touch screen, light transmission rate is of great significance in practical applications. The following are some of the importance of light transmission rate in practical applications:
3.1. User experience: a high light transmittance touch screen can provide clearer, more vivid images and better color reproduction, thus enhancing the user's visual experience. This is especially important for users who need to view the screen for long periods of time, such as users of cell phones, tablets and laptops.
3.2. Energy efficiency and energy saving: A high transmittance touch screen can reduce the brightness of the screen backlight, thus reducing the energy consumption of the device. This is especially important for mobile devices because they usually rely on battery power, and reducing energy consumption can extend the life of the device.
3.3. Adapt to different environments: A touchscreen with high light transmission can better adapt to different environmental conditions. For example, in direct sunlight, high light transmission touch screen can provide a clearer display, reduce reflections and glare; in low-temperature environments, high light transmission touch screen can reduce the problem of electrostatic dust adsorption, improve the reliability and stability of the device.
4. In order to improve the light transmittance of the touch screen, you can start from the following aspects:
4.1. Optimize the choice of materials: Selecting transparent plastic materials with high light transmittance as the substrate of the touch screen can significantly improve the light transmittance.
4.2. Improve structural design: By simplifying the structural design of the touch screen and reducing the use of multi-layer composite films, light scattering and absorption can be reduced and light transmittance can be improved.
4.3. Enhancement of manufacturing process: By adopting a fine manufacturing process and reducing errors and defects in the manufacturing process, the light transmittance and flatness of the touch screen can be improved.
4.4. Enhance the environmental adaptability: by improving the sealing performance and dustproof performance of the touch screen, reduce the impact of environmental factors on the light transmittance and improve the reliability and stability of the touch screen.
To summarize, light transmission is an important performance indicator of the touch screen, which is affected by a variety of factors such as material selection, manufacturing process and screen surface treatment. The transmittance of different types of touch screens varies, and high transmittance can enhance user experience, reduce energy consumption and improve outdoor readability. Therefore, various factors need to be considered to optimize the light transmission performance during the design and manufacturing process of touch panels.