Color Sensors and Detectors: A Comprehensive Overview

This page delves into the basics of color sensors and detectors, exploring how they convert light signals into a measurable form.

What is a Sensor?

A sensor is a device that converts one form of energy into another. The sensed value can be directly indicated to a human or indirectly read with the help of an Analog to Digital Converter (ADC) and a display unit.

Color Sensors: Identifying Colors

A color sensor is specifically designed for color sensing. This capability is valuable for color identification or sorting objects by their distinct colors.

Typically, color sensors operate based on the principle of identifying the wavelength of light. Color identification is usually performed within the visible light spectrum, which ranges from 380 nm to 780 nm.

Table 1: Color vs. Wavelength

Color Detectors: Building the Circuit

A color detector is a circuit built using components such as:

• Light Dependent Resistor (LDR) or Photo Diode
• Basic LEDs (Red, Green, Blue)
• Analog to Digital Converter
• Display Unit
• Micro-controller unit

The design and complexity of color detectors are tailored to specific application requirements.

Modern Color Sensors: Integrated IR Filtering

Many modern color sensors incorporate a built-in Infrared (IR) blocking filter. This filter minimizes the influence of unwanted IR light signals from sources like sunlight and other ambient light. The inclusion of an IR filter leads to more accurate color measurements.

Color Sensor Vendors and Models

The following table showcases some popular vendors and their color sensor models, along with key specifications:

Table 2: Color Sensor Vendors