By Bob Wudeck
BenQ

Sealed IP5X Certified Laser engines are the best answer to long-term projector life.

According to Futuresource, in 2022, sales of laser projectors in North America surpassed those of replaceable lamp projectors. But while laser projectors eliminate the cost and hassle of replacement lamps, they can be more vulnerable to long-term damage from dust than lamp projectors. For laser projectors — there are three areas to consider when choosing the right model for you:

• How dust can damage laser projector internal components
• Why dust can reduce the brightness and sharpness of the image
• New dustproof technology that can protect your projector from dust contamination

No classroom or boardroom is immune to dust pollution, and filters typically only reduce the amount of dust. According to the EPA website Air Trends, which tracks various types of airborne pollution, indoor dust varies in both size and intensity throughout the United States.

How Dust Can Damage Laser Projectors

While most electronic products sold today have been engineered to withstand a certain amount of dust, it can be a real problem with laser projectors due to the nature of laser light that may shorten the life expectancy of your laser projector.

What is “Molten Goo?”

Although dust can can be controlled with filters in lamp-based projectors, the high temperature of laser light inside a projector creates a bigger problem if dust happens to get inside the critical components of the projector. Here’s why.
When a laser beam strikes a dust particle, it transfers its photon energy to the dust, often vaporizing it and expelling it into the projector. As the dust begins to cool and transform back to a solid — it is essentially microscopic “molten goo” that is floating around in the projector. Eventually, the dust finds a landing place where it can cool down — but if it is on the lens or an exposed metal part, it could damage the projector. Over time, these little specks can add up and create problems.

Why Dust Can Reduce the Brightness and Sharpness of the Image

Dust accumulation inside a lamp or laser projector can create image quality and other problems. For example, if dust accumulates on a component that is creating the image, such as a polarizer, lens or LCD panel, it can create a “dust blob” that blocks the pixels and distorts the image. Projector manufactures can use several techniques to avoid this such as paper filters, or more advanced technologies such as magnetic hall sensors.

What Is a Dust-Proof Projector?

Rather than using paper filters, which require regular cleaning and still can allow some dust inside the projector, engineers realized that laser projectors need to be completely protected from dust to ensure that the image would look perfect every time it was turned on.

There were two major engineering issues in sealing a laser engine. The first is identifying and sealing every possible dust ingress point in the projector light engine. For a typical projector, there are typically a dozen or so locations that are susceptible to dust entry that needs to be sealed.

The second issue is cooling. Once the projector is sealed, it then needs to be properly cooled to ensure that it won’t overheat during use. Similar to ultra thin notebooks, a modern sealed laser projector uses metallurgical cooling techniques such as copper heat pipes to move heat from the interior sealed section of the projector rather than having to blow air directly onto the different optical components.

IP5X Testing and Certification

The best sealed projectors are certified using the industry standard IP5X dust test. This is the same test used by the Apple Watch to make absolutely sure that it is dustproof. This test uses different sizes of standardize dust particles and complicated dust chambers to test all the ingress points of the projector.