Touch Sensor Photosensor Contact Area Detection

The patent converts color data from RGB color space to HSV color space, which separates hue, saturation, and brightness components. This parameter transformation allows the system to focus on hue differences (which represent color changes due to finger contact) while being less sensitive to lighting variations (affecting brightness). The binarization process further transforms continuous color values into discrete categories, enhancing the distinction between contacted and non-contacted regions.

The patent replaces conventional touch detection mechanisms with an optical detection system using photosensors and image processing. Instead of relying on mechanical pressure sensors or capacitive changes, the system uses optical properties (color changes) of the finger to detect touch inputs, thereby eliminating malfunctions associated with mechanical wear and electrical interference.

The patent segments the color data processing into distinct stages: RGB to HSV conversion separates color attributes into independent components (hue, saturation, brightness), binarization divides the image into contacted and non-contacted regions, and noise filtering separates actual touch signals from spurious variations. This segmentation allows each processing stage to focus on specific aspects of touch detection, improving precision while managing complexity through modular processing.

The patent introduces HSV color space as an intermediary representation between the raw RGB sensor data and the final touch detection result. This intermediary format provides a more suitable framework for analyzing color changes due to finger contact, as the hue component directly reflects color variations while being independent of lighting intensity. The intermediary processing steps (conversion, binarization, filtering) act as mediators that transform complex raw data into reliable touch information.