Hitachi Projection TV Repair

!±8± Hitachi Projection TV Repair

A television that is able to magnify a small image to a viewable screen from a video signal using a projector is called projection television. The image is projected to a much larger size by the use of a bright beam of light and a lens system. The television that uses a separate projector and placed in front of the screen is called front-projection television. The one that has a projector located inside the box projecting images from behind the screen is referred to as rear-projection television. There are several different kinds of projection televisions determined by the projector type, as well as how the image is created before projection. They can be categorized as follows:

LCD projector

For the liquid crystal display LCD projector to display images, light from the metal halide lamp is sent through a prism that divides this light into three poly silicone panels of red, blue and green signal components of the video. Individual pixels are opened allowing light to go through, or closed to stop the light as the polarized light goes through the panels that are made up of the polarizer, analyzer and LCD panel. A wide range of colors and shades in the image are produced through the combination of closing and opening of the pixels. To get an ideal color temperature and a broader color spectrum, metal halide lamps are used. Apart from giving a broad color spectrum, the metal halide lamps have the capability to emit a lot of light in a very small area.

CRT projector

By firing a beam of electrons onto a phosphor-coated screen, the small CRT projector is able to create an image just the same way a traditional CRT television does. There are several ways to arrange the CRT. One is by using a tube coated with three phosphor coatings i.e. blue red and green. The other is by spinning a color wheel in the case of a black and white tube. The last option is the using of three CRTs; one blue, one green, and one red.

Pros And Cons For CRT Projectors

The Hitachi projector television is made of a CRT type of projector which has its own advantages as well as disadvantages compared to other types of projectors such as LCD models. The CRT projector has the following advantages: the CRT projector is able to display varying resolutions since it's not restricted to fixed pixel resolutions. It also has the ability to get a great black level as well as contrast ratio. The CRT projector also happens to have longer life spans compared to LCD models and can achieve brilliant color reproduction. As much as CRT projectors have several advantages compared to their LCD counterparts, there are a few disadvantages too. These include: since CRT is phosphor-based it is prone to burn-in. Depth-wise, the CRT projector is quite large and heavy, and has focus problems unlike the LCD projector that is quite the opposite. Also, to maintain color and brightness balance the other two CRTs have to be replaced even if only one fails.

Pros And Cons For LCD Projectors

As far as the LCD projector is concerned, it is much smaller than the CRT projectors. It is also quite easy to replace or repair an LCD chip compared to the CRT and it's not prone to burn-in, unlike the CRT. The individual pixels are visible on the large screen making it look like the viewer is looking through the screen. There are high chances of defective pixels. It has fewer viewing angles than CRT.