The 3 colors of the R, G & B LEDs are optimally selected according to the color combination. With Panasonic LX-100's Mark mode, the built-in "Automatic optimal LED selection function" automatically selects the LED for the largest contrast (S / N ratio) between the mark and base (non-mark area) to ensure optimal sensing. For more stable detection, the sensor makes selections according to the contrast and not according to the reflected light variation between the mark and base (non-mark area). This sensing mode automatically selects a single color from the 3 RGB LEDs to achieve an ultra quick 45 μs response time. The automatic optimal LED selection function automatically selects the LED that is most suitable for the sensing. This function is perfect for ultra quick sensing. The Color mode on the LX-100 series utilizes all 3 RGB LEDs to determine the RGB ratio of the mark color. The built-in 12-bit A/D converter enables high precision 1/4,000-resolution judgments. The figure below is a graphic description of this process.