led filament bulb development tendency
The larger the bulb, the smaller the light decay, which is proportional to the evaporation of tungsten deposition to block the light output. Inflatable bulbs, because they partially block the evaporation of tungsten filaments, have less light decay.
If the incandescent lamp is made of the same filament and is made in different sized foam bulbs, the light bulb at the same time is relatively smaller than the small bulb shell. In addition, bulbs that are filled with large glass bulbs also have a large internal space. Gas convection has a relatively large heat-dissipating area to the glass bulb. The temperature of a relatively small glass bulb is much lower, the filament temperature is also relatively low, and the luminous efficiency is low. The evaporation rate is also low, so the light decay is small. However, the same filament in the large glass bulb has much lower luminous efficacy than the small bulb. Therefore, when the filament design is designed separately, it has little significance in practical production.