Working Principles of Different Projectors

23.07.2020 0 iCODIS Official

Projector, also known as an optical device, is a device that can project images or videos onto a curtain and can play corresponding video signals through different interfaces with computers, VCD, DVD, BD, game machines, DV, etc. Projectors are currently widely used in homes, offices, schools, and entertainment venues. There are different types of projectors, such as CRT, LCD, DLP,  depending on their working methods. And as they become more and more popular, many people shop projectors online.


As an imaging device, it is the earliest and most widely used display technology. This projector can decompose the input signal source into R (red), G (green) and B (blue), and then display them on the screen of CRT tubes. The fluorescent powder can be amplified and converged by the light-emitting system under the action of high voltage to display color images on the large screen.


Projector uses the photoelectric effect of liquid crystal, that is, the arrangement of liquid crystal molecules changes under the action of the electric field, which affects the light transmittance or reflectivity of its liquid crystal unit projector, thus affecting its optical properties and producing images of different gray levels and colors. LCD projectors are the mainstream products in the projector market due to their good color restoration, resolution up to SXGA standard, small size, lightweight and portability.


DLP uses DMD(Digital Micromirror Device) as a light valve imaging device. A DLP computer board consists of an analog-to-digital decoder, a memory chip, an image processor, and several digital signal processors (DSP). All text images pass-through this board to generate a digital signal. After processing, the digital signal is transferred to DMD, the heart of the DLP system. After passing through a high-speed rotating three-color lens, the light beam is projected onto DMD and then projected onto a large screen through an optical lens to complete image projection.

Working Principles of Different Projectors