Identification of colors and wavelengths from the light coming from monitors and TVs displays using a homemade spectrograph

Abstract

The National Curricular Common Base (BNCC) sets a guideline for the Basic Education and the common educational background to be spread across all regions of Brazil. This document brings a set of recommendations highlighting the need to offer a contextualized education based on the development of skills and competences of the students. In face of this scenario, this work brings an experimental activity that teaches some objects of knowledge related to Physics of Waves, by means the study of the formation of color images on monitors, TVs and screens in general. This investigation starts from the analysis of the colors that comes from the light observed in the calibrated spectra from two different TVs: one LCD and another a LED display. The methodology involved the assembly of the experimental apparatus to obtain the spectra, the steps for the treatment of the spectra, in order to allow its calibration and, finally, the steps for the spectra calibration. As a result, we obtained calibrated spectra in the wavelength range of the colors of the LEDs used in the RGB system of the screens and from which we were able to determine their central wavelengths and wavelength bands. In this sense, this work composes a potentially significant learning material, correlating the contents of Physics with elements of the students' daily lives.