What is ALR projector screen？

An ALR (Ambient Light Rejecting) projector screen is designed to improve the quality of the image by rejecting or minimizing ambient light in a room. This type of screen helps ensure that the projector’s image remains clear, bright, and sharp, even when there is light in the room. It works by using a special coating or material that reflects only the light coming directly from the projector, while rejecting light coming from other sources (like overhead lighting or windows).

Here’s how ALR projector screen works and the core technology

The screen is engineered to reflect only the light from the projector and absorb or diffuse ambient light, which can wash out the image on a standard screen. By rejecting side or overhead light, the ALR screen enhances the contrast ratio, making dark scenes appear deeper and more vivid, even in well-lit rooms. And it’s especially useful in rooms with lots of ambient light, such as living rooms with windows or rooms with strong overhead lighting.

• The core technology lies in the screen’s optical structure: ALR screens use micro-layered optical coatings (e.g., sawtooth patterns or lenticular lenses) to direct projector light toward the viewer and scatter ambient light from other directions.
• For ultra-short-throw (UST) projectors, ALR screens often employ a “black grid” or “Fresnel” layer to reject ceiling light specifically (termed CLR, or Ceiling Light Rejecting). The ALR screentypically has a low gain (0.3–0.6), absorbing stray light rather than reflecting it broadly. This reduces hotspots and boosts contrast but narrows the optimal viewing angle (usually 160°–170°).