Projectors are one of the devices that are quite needed in today’s technological advances. Devices that can display images, videos, or presentations on a much larger size on a flat surface are needed for various interests.
These devices are much needed in the world of entertainment to display videos or watch together favorite soccer clubs in cafes. For presentation purposes, projectors are needed in the world of education and business.
But do you already know the history, workings, and types of projectors? In this article, we will review this device from the definition, history, workings, and types.
What is a Projector?
Simply put, a projector is an optical device that receives video or image signals from an external source and then displays them on a larger surface.
Projector technology has continued to evolve rapidly over time and now comes in many different types with advanced features such as 4K projection, automatic keystone correction, and wireless connectivity.
Modern products are also increasingly user-friendly and can easily connect to various devices, such as laptops, smartphones, or gaming consoles.
Today, the use of the technology is not limited to classrooms or meeting rooms, but also for various other purposes, such as watching movies at home or enjoying outdoor entertainment.
History
The first LCD projector was invented by scientist Gene Dolgrof from New York. He started his work in college in 1968 intending to create a video projector, and in his vision, he planned to create an LCD projector that was brighter than the 3-CRT projector.
To realize this idea, he used an element called a valve light to regulate the amount of light passing through it. After trying various materials, in 1971, he finally settled on liquid crystal as the light regulator.
His struggle continued until 1984 when he succeeded in obtaining “addressable” technology for liquid crystal displays (LCDs), which allowed him to create the world’s first LCD projector.
How it Works?
The operation of a projector begins with the generation of light and ends with the projection of the displayed image. High-intensity bulbs, LEDs, or laser diodes serve as internal light sources that emit intense light.
The light needed to illuminate this image is then split into the primary colors (red, green, and blue). This process is carried out by optical components such as dichroic filters or a high-speed rotating color wheel.
Next, the projector forms the image from the light that flows into its internal chip (such as an LCD panel or a DLP micro-mirror chip). This is where the incoming video signal, which forms the light, is converted into individual digital pixels.
The focused image passes through the projector’s lens, where the light is magnified and projected onto a screen or wall. This allows us to see a large, clear image.
The Types
Here are the different types of projectors that exist:
1. LCD (Liquid Crystal Display)
LCD projectors are an evolution of the older overhead projector (OHP) models. This type projects light through a liquid crystal panel to produce sharp, bright images with high color accuracy.
In everyday life, these devices are very popular. The projectors you often see in offices and classrooms are LCD projectors.
2. DLP (Digital Light Processing)
DLP projectors are equipped with a semiconductor chip (DMD). This chip uses millions of microscopic aluminum mirrors to reflect light.
This is what enables it to produce sharp contrast, response times measured in microseconds, and deep black levels. It is ideal for home theaters and action-packed sports broadcasts.
3. LCOS (Liquid Crystal on Silicon)
LCOS is a projector that combines the advantages of both LCD and DLP technologies in a single device. This type of device uses a reflective liquid crystal panel on a silicon backplane.
As a result, you’ll enjoy extremely high resolution and smooth, cinematic image quality. These devices are often used in high-end, premium displays.
4. Laser & LED Projectors
Laser and LED projectors do not use traditional lamps; instead, they use LED or solid-state laser light sources. This makes them last longer than other types of projectors.
These devices generate less heat and can last up to 20,000–30,000 hours without needing a lamp replacement, making them a cost-effective choice for long-term use.
Factors to Consider When Choosing
When setting up a display system for entertainment or professional use, another option to consider is a large-screen smart TV. However, you may choose a projector by considering the following operational factors:
- Giant Screen Size at a Lower Cost: Projectors offer a cinema-scale viewing experience at a lower cost.
- Reduced Eye Strain: By utilizing light reflected off a screen or wall, projectors make the viewing experience much more comfortable for the eyes.
- Space Flexibility and Portability: Their compact size and light weight make projectors easy to store or move between rooms or to outdoor locations.
Devices Must Be Certified
Modern projectors are often equipped with Bluetooth or Wi-Fi features that enable wireless connections from source devices. This is why they require type approval certification.
Without this certification, the devices cannot be sold or used in a country. This certification is a strict requirement for obtaining legal compliance.
It’s not just an administrative matter. Devices that have been tested and certified are guaranteed to be safe to use and free from interference during operation.
Certified devices usually bear a label from the relevant national regulatory authority on the device itself or its packaging. In Indonesia, this certification is regulated by the Directorate General of Digital Infrastructure (DJID).
Make sure the DJID logo is present on the telecommunications device you’re using—in this case, your projector. Using a certified device helps you avoid potential risks.
