Light-emitting diode superior for illumination in terms of color rendering, whereas one cannot appreciate the color of red or green objects illuminated only by the yellow (and remaining blue) wavelengths from the YAG phosphor. The first white LEDs were expensive and inefficient. However, the light output of LEDs has increased exponentially, with a doubling occurring approximately every 36 months since the 1960s (similar to Moore's law). The latest research and development has been propagated by Japanese manufacturers such as Panasonic, Nichia, etc. and later by Korean and Chinese factories and investment such as: Samsung, Solstice, Kingsun, and countless others. This trend is
LED filament LED filament An LED filament light bulb is an LED lamp which is designed to resemble a traditional incandescent light bulb with visible filaments, for aesthetic and light distribution purposes. It produces its light by LED filaments, multi-diode structures that resemble the filament of an incandescent light bulb. They are designed as drop-in replacements for conventional clear incandescent bulbs used in decorative light fixtures, such as table lamps, pendant lights, chandeliers, and bulb-based candelabras. They have the appearance of traditional incandescent bulbs but the higher efficiency of light emitting diodes (LEDs). A LED filament type design light bulb was produced