LCD projector using LCD light gates. This is the simplest system, making it one of the most common and affordable for home theaters and business use. Its most common problem is a visible screen door or pixelation effect, although recent advances have reduced the severity of this effect.
DLP projector using Texas Instruments DLP technology. This uses one, two, or three called digital micromirror devices (DMDs).
LED projectors use one of the above mentioned technologies for image creation, with a difference that they use an array of Light Emitting Diodes as the light source, negating the need for lamp replacement.
Hybrid LED and Laser diode system developed by Casio. Uses a combination of Light Emitting Diodes and 445 nm laser diodes as the light source, while image is processed with DLP (DMD) chip.
Laser diode, projectors have been developed by Microvision and Aaxa Technologies. Microvision laser projectors use Microvision's patented laser beam-steering technology, whereas Aaxa Technologies uses laser diodes + LCoS.