Industry info - Surface Capacitive vs Projected Capacitive Touchscreens. Which Is Your Best Choice?
Time:2023-02-18
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There are two different types in capacitive touch technology: surface capacitive and projected capacitive touchscreens. Although, they both work by detecting changes in capacitance, a few noticeable differences would enable you to decide whether you should get surface capacitive or projected capacitive touchscreens for your applications.
1. SURFACE CAPACITIVE TOUCHSCREENS
Surface capacitive touchscreen sensors include a transparent conductive layer on a glass substrate under a protective silicate layer. The controller interface applies a high-frequency signal to an electrode at each corner of the conductive layer, resulting in the formation of a uniform electrostatic field. When a touch event happens on the screen, it creates capacitive coupling with a resistance to the ground, dissipating the signal, and the change in signal at each corner is measured to locate the touch-point.
Advantages:
a. Suitable for large size monitors;
b. High resolution and high response speed;
c. Doesn’t get affected by moist, dust, or grease.
Disadvantages:
a. Conductive coating is susceptible to scratches and abrasions;
b. Doesn’t support multi-touch.
2. PROJECTED CAPACITIVE TOUCHSCREENS
Similar to surface capacitive, projected capacitive touchscreens also detect touch commands by measuring capacitance. However, the difference is in the construction. PCAP touchscreen sensors have two vertical layers of conductive coatings that form vertical and horizontal patterned tracks behind a glass top layer. When a finger nears the glass screen it changes the mutual capacitance between the horizontal and vertical patterned tracks. The controller scans each cell of the horizontal and vertical grid with a high frequency signal, identifying any changes in mutual capacitance between adjacent cells as touch locations.
Advantages:
a. Suitable for smartphone, laptop etc;
b. Long live and high durability;
c. Excellent optical property;
d. Supports multi-touch, thus supports various elaborate inputs.
Disadvantages:
a. Susceptible to electrical noise due to its detection mechanism;
b. High processing cost.
Both surface capacitive and projected capacitive touchscreens have their own distinctive features and are best suited for a variety of applications. However, it is completely your preference to select the touchscreens as per your specific requirements.
