Uninterrupted Learning Through Long-Lasting Projection. The World's No.1 DLP brand BenQ leads the way with futureproof interactive projectors, featuring innovative BlueCoreTM laser technology and superior dustproofing design for superb picture quality and maintenance-free operation. Maximizing education investment and collaborative learning with short throw projection, BenQ LX820ST / LW820ST utilize the unparalleled qualities of a laser light source to achieve optimized performance, long-lasting reliability, energy efficiency and environmentally friendly choice for the leading school. BenQ BlueCoreTM Laser Technology Laser Technology for Pure Color Powerful BlueCore laser projectors employ dual color wheel systems to unleash outstanding color performance by increasing color ratios and purity of RGBY color, greatly enhancing color saturation and brilliancy at the same lumen output of lamp-based projectors to deliver superior viewing experiences. Superior Bright Precision-Aligned High-Output Laser Source Zero-deviation alignment of BlueCore laser diodes boost luminous flux into the light tunnel, improving light efficacy to 3,600 lumens. Superior Performance Secondary Yellow-Infused Color Wheel Dual synchronized BlueCore color wheels utilize an additive yellow segment, stimulating precise RGBY spectra for optimal chromatic performance. Superior DurabilityHermetically Sealed DLP Chip Comprising over two million micromirrors that reflect pure light through the color wheel, the DLP chip is hermetically sealed to resist heat for over 100,000 hours without degradation. Superior Dustproofing Design to Prolong Projector Lifespan BenQ LW820ST is designed with Dust GuardTM technology including sealed laser modules to protect the laser bank. This lock-and-key design hermetically seals the laser engine from dust* to prolong projector lifespan. Dust chamber test standard: JIS Class IP5X Sealed Engine for Laser Light Source With a fully enclosed laser light source and an innovative sealed engine design powered by BenQ Dust GuardTM technology, BlueCore education projectors guarantee 20,000 hours of maintenance-free operation to prevent extra expenses on lamp replacement and maintenance. The laser light source resists brightness decay, making BenQ laser education projectors highly stable while ensuring high brightness performance through years of usage. Anti-Dust Accumulation Sensor Resists Dust Buildup Incorporating color wheel sensors with an ingenious anti-dust accumulation feature, LW820ST prolongs optimal performance by rejecting dust which can accumulate on traditional sensors to block the IR signal and cause flickering, abnormal colors, or even shutdown. Brilliant Display of Lecture Content LW820ST's powerful BlueCoreTM laser projection utilizes a dual color wheel system to produce outstanding color performance by increasing color ratios and purity of RGBY colors, greatly enhancing color saturation and brilliancy at the same lumen output of lamp-based projectors to deliver superior viewing experiences.