Color Recognition Theory by using Low cost sensor and Controller

1) Suggest Usage

    For all low cost Electronic Toys with color reorganization up to 12 difference color.  Apply in Doll, educational toys, color learning etc.

2) Suggest microcontroller

    8 bit embedded controller with Large Rom, LCD drive and high operation speed.

3) Basic Theory

    By reflection of 3 difference color lights (Red, Green and Blue) and measuring their feedback light intensity by a light sensor.   Difference color of the surface will reflect difference intensity of color light.  For example, a pure blue almost only reflect blue light and reflect nothing for Red and Green light.

Basically, the printing color is combined with basic 'YELLOW',  'MAGENTA' and 'CYAN'.  Yellow has good reflection of  Red and Green light.  Magenta has good reflection of Red and Blue, Cyan has good reflection of Blue and Green.  The reflection will be in ratio of the density of the printing itself.  It also depend on the reflection light intensity.  Certainly, we also need to consider the sensor specification.  Normally, photo sensor have high sensitivity to Red and lower to Blue.  It need the adjustment and modification using both hardware and software programming.

4) Detection Head 

   5)  Header Basic Requirement

- The header is either a square or a circle tube using black plastic.  All the LEDs and photo transistor is located inside the tube and facing at an angle toward the surface. Minimum X and Y dimension is around 12mm Minimum Y (height) is around 30mm.

   6) A more detail application using  KB controller