Principle of Operation of Resistive Touch Panels
Resistive touch panels, which are visually similar, are different solutions characterized not only by their operating principle but also by factors such as sensitivity, precision, resistance to damage, and light transmittance.
Touch panels are a universal term used to refer to the combination of displays, touch sensors, and glass. In our offering, we consistently provide two types of touch sensors: resistive (RTP) and capacitive (CTP) touch panels. Upon request, we can also provide solutions using other technologies, such as IR (infrared).
Below, we provide a characterization of resistive touch panels.
Characteristics of Resistive Touch Panels
Resistive touch panels operate based on the principle of detecting changes in resistance. They consist of two layers: a flexible top layer and a rigid bottom layer. Both layers are coated with layers of indium tin oxide (ITO) on their inner surfaces. When the screen is touched, the top and bottom layers come into physical contact, resulting in a point of contact and a change in resistance. This change in resistance is measured and processed into a touch point by the controller.
Resistive touch panels offer certain advantages, such as the ability to operate with any object (not limited to conductive objects) and the ability to function even with gloved hands. However, they may have lower sensitivity and require more pressure compared to capacitive touch panels.
It’s important to consider the specific requirements and intended use of the touch panel when selecting between resistive and capacitive options.
Principle of Operation of Resistive Touch Panels
In resistive touch panels, the determination of position is achieved by detecting changes in resistance. Resistive sensors consist of two layers: a flexible top layer and a rigid bottom layer. Both layers are coated with indium tin oxide (ITO) films on their inner surfaces. When the screen is touched, the top and bottom layers come into physical contact, creating a point of contact and resulting in a change in resistance. This change in resistance is measured and processed into a touch point by the controller.
How to Choose the Right Resistive Touch Panel from Our Offering
When selecting a touch panel, it’s important to consider several key parameters, such as:
- Requirements regarding size and aspect ratio of the display;
- Glass thickness, which affects the durability of the touch panel;
- Type of built-in controller.
Calibration of the Touch Panel
In addition to the basic parameters, it’s also important to consider factors present in the operating environment that may require calibration of the resistive touch panel (this is an additional service that can be provided in collaboration with the Unisystem team). In certain projects, enhancements such as the following can be implemented:
- Water rejection mode, which ensures proper operation of the touch panel in the presence of water on the screen surface;
- Palm rejection mode, which ensures proper operation of the touch panel when larger objects, such as the entire palm, come into contact with the screen;
- Noise detection or frequency hopping functions, which dynamically adjust the module’s operation to the prevailing environmental conditions. This functionality is particularly useful for handling frequent changes in the level and frequency of interference.
Finishing of the Touch Panel – Glass Customization
Attention is drawn to visually appealing devices, which prompts manufacturers to create solutions that undergo various modifications, such as edge painting of the glass.
Increasingly, designers are taking advantage of the possibilities offered by glass customization, which includes:
- Trimming of the glass;
- Cutting holes in the glass to accommodate necessary mechanical elements like buttons, switches, or knobs;
- Glass painting.
Learn more about designing custom touch solutions.