Thermal Countermeasures for Compact, High-Performance Projectors
Projectors are being used in a diverse range of applications and environments that require them to be smaller yet more powerful and reliable. They have many more heat-generating parts than other common electronics. Simply adding more air-cooling fans would increase product size and noise, so Epson has developed different strategies for combating the heat generated by projectors.
From presentations to home theaters, projectors are used in a wide range of applications and in
a variety of environments such as offices, schools, and homes. They are also increasingly being used for
projection mapping and events, either outdoors or in smoky environments. Moreover, with the diversification of
video content over streaming and online distribution services, we are seeing projectors used in more places
than ever before.
As the environments in which they are used expand, projectors need to offer brighter pictures with higher resolution as well as better dust protection and reliability. Meanwhile, there is a strong demand for projectors that are smaller and quieter, which can come at the cost of brightness, resolution, and so forth. We have been working for years to address projector heating issues in order to achieve these technical requirements and goals.
Thermal countermeasures for HTPS panels
Epson fabricates its own high-temperature polysilicon liquid crystal TFT (HTPS) panels, the core devices in 3LCD projectors, and has worked to develop cooling systems and HTPS panels that can be efficiently cooled. For high brightness projectors, Epson uses a high-efficiency liquid cooling system to achieve excellent product reliability. For thin mobile projectors, Epson developed a space-saving heat sink that efficiently dissipates heat while keeping the projectors small enough to fit in a carrying case.
Epson's cooling system assures reliability for high brightness projectors
High brightness projectors are sometimes used in harsh, dusty environments. To protect the optical components against dust contamination, Epson seals the optical engine in a block. However, sealing the optical engine traps heat, so Epson developed a total liquid cooling system to efficiently cool the insides of these projectors. In this system, antifreeze is circulated inside the projector to collect the trapped heat and the heat produced by key devices such as the HTPS panels, phosphor wheel, and laser light source. This heat is exchanged with a radiator, which exhausts it to the outside of the projector. This system not only cools the inside of the sealed block but also improves the cooling efficiency of the entire product. The key devices are kept at the optimal temperatures, which also results in smaller products and lower noise.
For laser light source engines, which generate heat, a phosphor wheel that has excellent heat resistance is used to ensure long-term reliability.
The technical know-how for controlling heat is also applied to other devices such as power supplies, circuits, and projection lenses, contributing to higher performance and heat control for each device. Epson's total heat control efforts paved the way to outstanding reliability while helping to enable high brightness, high resolution, dust protection, miniaturization, and low noise.