Damage to the DMD chip will cause black spots, white spots or snowflakes in the projector image, which need to be replaced to solve. The price is more than 400 and less than 1,000 (ordinary models). The core of the DLP rear projection is the DMD chip, which is only the size of a matchbox and is densely arranged with 800,000 to 1 million small mirrors, and each small mirror can be independently turned 10 degrees in the direction of positive and negative, and can be turned 65,000 times per second. The light source is reflected through these small mirrors to form an image directly on the screen. Therefore, DLP projection technology abandons the optical convergence in the traditional sense, can change the focus at will, and it is very convenient to adjust, and its optical path is quite simple, and the volume is smaller. As a result, the body of a DLP rear-projection TV can be made correspondingly thinner. The volume is no longer huge, greatly reducing the placement space, and the energy consumption is also reduced a lot. From the price point of view, the popular single-chip DMD technology in DLP is also in line with the affordability of ordinary users compared with liquid crystal display. General three-tube back projection TV inevitably produces X-ray radiation, but DLP's DMD chip itself uses the principle of digital optical reflection, will not emit X-rays, can protect the health of the viewer. At present, the market on the radio and television and LG have this product, Samsung and Thomson similar products will also be listed.