With the continuous progress of technology, there are many types of touch screen on the market, with different performance, how to choose the right touch screen according to the actual needs has become a key issue. So, which parameters to understand when choosing a touch screen?
Touch screen products, based on their technical principles, can be divided into three main categories:
The first is resistive technology touch screen. These products consist of two layers of transparent metal oxide (ITO) film and a conductive layer. When the touch screen is pressed, the two layers of ITO film will contact and form a current, so as to accurately locate the touch position. Resistive technology touch screen is affordable, anti-interference ability, very suitable for industrial environments. However, it has a slightly lower light transmittance, is prone to wear and tear, and does not support multi-touch.
Next is the surface acoustic wave technology touch screen. It works through a set of transmitters and receivers that transmit and receive high-frequency surface acoustic waves along the edge of the touch screen. When the touch screen is touched, the sound waves will be partially absorbed to determine the touch position. Such products have high light transmission, long life and support multi-touch. However, they are relatively expensive, susceptible to dust and water droplets, and not suitable for environments with water vapor or oil.
Finally, there is the capacitive technology touch screen. It uses a glass screen covered with a transparent conductive material to form a capacitor. When a conductive object (e.g. a finger) is approached, the capacitance value of the capacitor is altered to accurately determine the location of the touch. Such products are sensitive to touch, support multi-touch and scratch-resistant, very suitable for high-end consumer products. However, they are the most expensive, require a dedicated stylus, and are not suitable for gloves or static environments.
When selecting a touch screen, several factors need to be considered to ensure that the selected product can meet the specific needs of the project. The following are a few crucial parameters:
1. Size and resolution
Size: The size of the touch screen directly affects the portability and operating space of the device. Choosing the right size requires consideration of the application scenario, user habits, and the overall size and design of the device. For example, handheld devices tend to be smaller to ensure portability, while industrial control panels may require a larger size to facilitate operation.
Resolution: Resolution determines the number of pixels on the screen and directly affects the clarity and detail of the image. Higher resolution touchscreens provide a more detailed display, which is especially important in scenarios where complex graphics or detailed content needs to be displayed.
2. Touch technology
As mentioned earlier, the choice of touch technology is directly related to the performance and experience of the touch screen. Resistive for simple operation, cost-sensitive applications; capacitive is more suitable for high precision, fast response and multi-touch occasions. In addition, it is also necessary to consider whether the need for waterproof and dustproof, scratch resistance and other special properties, which may affect the choice of touch technology.
3. Transmittance and Brightness
Transmittance: Especially for outdoor use, a high transmittance touch screen can ensure that there is still good visibility under bright light. Generally speaking, the light transmission rate of capacitive touch screen is better than resistive.
Brightness: The brightness of the screen determines the readability of the screen content under different lighting conditions. Higher brightness screens are better suited for outdoor or bright light environments, while lower brightness settings help save energy and extend battery life.
4. Durability and Longevity
Durability: This includes characteristics such as scratch resistance, impact resistance, and chemical resistance. For industrial use or frequently operated devices, it is critical to select a touch screen with high durability.
Lifespan: Usually measured in terms of number of touches, such as millions of touches without failure. A long-life touch screen reduces maintenance costs and improves the overall reliability of the equipment.
5. Response time and sensitivity
Response time: refers to the time from the user's touch to the screen to the system to respond. A shorter response time provides a smoother operating experience, especially important in games, graphics and other applications that require rapid feedback.
Sensitivity: Determines the touch screen's ability to sense light touches. A highly sensitive touch screen can more accurately capture the user's intent and reduce misuse.
6. Power Consumption
Power consumption directly affects the battery life and operating cost of the device. A low power consumption touch screen design is especially important for portable devices and systems that require long periods of continuous operation. When choosing, you need to balance performance and power consumption to find the optimal balance.
7. Interface and Compatibility
Interface: The connection between the touch screen and the controller (e.g. USB, I2C, SPI, etc.) needs to be matched with the host interface to ensure the stability and speed of data transmission.
Compatibility: including operating system compatibility, driver support, etc.. Ensure that the touch screen can be seamlessly integrated into the existing system, reducing the difficulty of development and debugging.
8. Cost and budget
Cost is a factor that cannot be ignored in any purchasing decision. The price of a touch screen varies depending on brand, technology, size and other factors. When selecting a model, it is necessary to make comprehensive consideration based on the project's budget and long-term operating costs, and choose the most cost-effective program.
9. Environmental and Climatic Conditions
Consider the environmental conditions in which the touchscreen will be deployed, such as temperature, humidity, electromagnetic interference, etc. In extreme environments, it may be necessary to select a touch screen with special protective measures, such as explosion-proof, waterproof, dust-proof and other higher level products.
Touch screen selection requires comprehensive consideration of size, resolution, touch technology, expansion and compatibility, environmental adaptability and other parameters and other aspects. According to the specific application scenarios and needs to choose the right touch screen model and brand is crucial.