How do straight tube lamps achieve high light transmittance and uniform, soft light, avoiding the glare of traditional LED bulbs?
Publish Time: 2025-11-27
In today's era of widespread LED lighting, straight tube lamps, as a mainstream replacement for traditional fluorescent lamps, are widely used in indoor spaces such as offices, schools, shopping malls, and hospitals. However, some early LED straight tube lamps, due to directly exposed bulbs or the use of inferior diffusion materials, often suffered from problems such as glare, uneven brightness, and severe flickering, affecting visual comfort and potentially causing eye fatigue and even headaches. Modern high-quality straight tube lamps—especially those employing a structure of transparent glass tube + PET coating + scientific optical design—achieve a perfect balance between high light transmittance and uniform, soft light through the synergy of multiple technologies, completely eliminating glare and providing users with a comfortable and healthy lighting experience like natural light.
The core breakthrough lies primarily in the composite optical system of the transparent glass tube and the PET (polyethylene terephthalate) coating. Unlike frosted plastic tubes, which suffer from excessive light scattering and luminous efficiency loss, high-purity transparent glass boasts a light transmittance of over 92%, maximizing the preservation of the original brightness of the LED light source. Furthermore, a microstructured PET optical film is precisely coated onto the inner or outer wall. This coating is not simply "frosted," but rather uses nanoscale microprisms or diffused particle arrays to perform secondary optical homogenization of the intense light emitted by the point-source LED light source. As light passes through the PET coating, it is refracted and scattered multiple times, transforming the originally concentrated light spot into a continuous, soft surface light source, effectively eliminating the graininess of the LED beads and localized high-brightness areas, achieving a "see the light, not the lamp" visual effect.
Secondly, optimized light source layout and driving circuitry further suppress glare. High-quality straight tube lamps typically employ a linear arrangement of high-density, low-power LED chips, coupled with a constant current driving power supply, ensuring consistent brightness and flicker-free operation for each LED bead. Simultaneously, a reasonable distance is maintained between the LED module and the inner wall of the glass tube to prevent direct light from shining into the eyes. Some high-end products also incorporate side-emitting or light-guide plate technology, allowing light to diffuse evenly from the sides of the tube wall instead of being projected directly forward. This significantly reduces the peak brightness (UGR – Uniform Glare Value) at vertical viewing angles, meeting the international comfort standard of UGR < 19 for office lighting.
Furthermore, the optical stability of glass far surpasses that of plastic. Ordinary PC or PS plastic lamp tubes are prone to yellowing and fogging after long-term use, resulting in a decrease in light transmittance of over 30% and irregular scattering due to surface aging, exacerbating visual discomfort. Sodium-calcium or borosilicate glass, on the other hand, is chemically stable, UV-resistant, and heat-resistant, exhibiting almost no color decay over its 50,000-hour lifespan, consistently maintaining high light transmittance and uniform light output. Combined with the anti-static treatment of the PET coating, it also reduces dust adhesion, maintaining cleanliness and brightness over the long term.
In practical applications, this design advantage significantly enhances the user experience: in open-plan offices, employees no longer suffer from overhead lighting interference when facing computer screens for extended periods; in classrooms, students do not squint when looking up at the blackboard due to glare; and in retail spaces, product colors are accurately reproduced without strong light spots obscuring details. More importantly, the high color rendering index (Ra≥90) and flicker-free characteristics make the light closer to natural sunlight, effectively relieving eye strain and protecting eye health.
Ultimately, a truly excellent LED straight tube lamp is not only "bright," but also "soft"; not just an energy-saving tool, but also a health partner. It uses the transparency of glass to hold the purity of light, and the intelligence of PET to tame the sharpness of light, delivering on its promise of comfort and quality through meticulous optical design. When a lamp can brighten a space without being glaring, and allow for focused work without fatigue, we know: good lighting should be this gentle.
