Constructing a capacitive sensor using springs 4

Figure 7 shows a circular spring used for standard buttons. The manufacturing process of this circular spring button is very simple, and the central space can be utilized for backlighting or other purposes. Figure 8 displays a circular spring with higher sensitivity. When the cover layer contacts and presses down the spring, the wider end retracts, forming a solid-state sensor. This not only enhances sensing sensitivity but also allows for the use of thicker cover layers.

A better way to construct the slider is to use rectangular springs (see Figure 9). When several rectangular springs are arranged in a row, they can more effectively cover the slider's sensing area. Additionally, the width of rectangular springs is smaller than that of circular springs, allowing for the construction of sliders with more spring sensors.  diode

The slider composed of springs, as mentioned earlier, exhibits a higher lateral sensitivity. This sensitivity is an advantage in slider applications. When the overlay layer is thick and interpolation is used, under the same conditions of fragment quantity and overlay thickness, the slider composed of springs demonstrates better linearity compared to the solid-state conductive slider.

Due to the frequent overlap of electric fields among adjacent fragments, the signal distribution of spring slider fragments exhibits greater deviation. When employing the centroid algorithm, the smaller the deviation in electric field distribution between different fragments, the better the linearity of contact position calculation. Figure 12 displays the interpolation linearity of conventional sliders and spring sliders under identical overlayer thickness conditions. The figure demonstrates that the spring slider exhibits superior linearity.  diode