What Is a Touch Switch?
A touch switch is a switch that is turned on and off by touching the screen with a user’s finger or pen.
Various detection methods are available, such as capacitive, resistive, and infrared, and are used according to the application. Compared to buttons and keys, switches can be placed on a flat surface and are superior in design, so they are widely used in operation panels of AV equipment and industrial equipment, and in operating units of public equipment.
It was also a pioneer in touch operation even before the appearance of touch-operated products such as smartphones and tablets. Recently, smaller and thinner touch switches are required to accommodate the miniaturization of mobile devices and the IoT.
In the development of touch switches, reliability and cost performance, as well as improved operability, have become important factors.
Uses of Touch Switches
Touch switches that we often see in our daily lives are mainly intended for human operation. Examples include pushbuttons for electrical appliances in homes, elevators in shopping malls, and automatic doors. Recently, capacitive touch switches that are activated simply by touching the screen, such as smartphones and touch panels, are becoming the mainstream.
Touch switches are also widely used inside industrial robots and machine tools. At hazardous sites such as factories, they also serve as safety devices to prevent workers from entering or being pinched and to detect damage to tools.
Principle of Touch Switches
As the name suggests, touch switches are operated by touching. The most appropriate type of touch switch should be selected according to the operating environment and purpose.
1. Capacitive Touch Switch
Capacitive touch switches utilize the fact that the human body is a conductor of electricity. When a finger approaches the surface of the switch, the capacitance changes, and the switch turns on or off by detecting this change. This technology is often used in touch screens for smartphones and tablets.
2. Resistive Touch Switches
Resistive touch switches have two conductive layers with an insulating layer in between. When the user touches the surface, the two conductive layers come into contact and an electric current flows. The change in this current is detected and the operation of the switch is controlled.
3. Infrared Type Touch Switch
Infrared touch switches use an infrared sensor to detect the proximity of the user’s hand or finger. The sensor emits infrared light and detects the reflected light. As the hand or finger approaches, the amount and angle of the reflected light changes, and the switch operates based on this change.
Types of Touch Switches
Touch switches are used in many situations, and their range of application is expanding every day. However, not all touch switches are the same.
It is important to select the most appropriate type depending on the specific application and environment.
1. Low Power Type
This is a touch switch with extremely low power consumption. Suitable for battery-powered portable devices.
2. High Durability Type
This type can maintain high performance for a long period of time. Often used in industrial applications and public facilities.
3. Multi-Point Type
This type of touch switch can detect multiple touch points simultaneously. Often seen in smartphones and gaming devices.
4. Other
Types that operate stably even in environments with a lot of moisture or dirt are useful in kitchen appliances and medical equipment. Some types can also be customized for specific applications or special environments. They are used in multifunctional operation panels and special industrial applications.