LCD vs Plasma Screens

How Plasma Screens work?

Plasma monitors work much like CRT monitors, but instead of using a single CRT surface coated with phosphors, they use a flat, lightweight surface covered with a matrix of tiny glass bubbles, each containing the gas-like substance, plasma, and having a phosphor coating. Each of the "pixels" in this matrix is actually comprised of three sub-pixels, corresponding to the colors red, green and blue.

In a CRT monitor, an electron beam is fired from the rear of the long picture tube, hitting the phosphors on the front surface which makes them glow. Complex circuitry and high voltage deflections coils are required to aim, focus and move the beam to create an entire image.

Plasma displays eliminate the need for high voltage deflection coils and the long neck of a CRT. In a flat plasma monitor, a digitally controlled electric current flows through the appropriate parts of the matrix, causing the plasma inside the bubbles to give off ultraviolet rays. These rays in turn cause the bubbles' phosphor coatings to glow the appropriate color.

How LCD Screens Work?

LCD monitors use liquid crystal display (LCD) technology, making it far different from the ordinary CRT monitor. An LCD is a thin and flat display device composed of pixels arrayed in front of a light source or reflector.

LCDs, in turn, use liquid crystals, which were first discovered in 1888. These crystals are actually liquid chemicals that align perfectly when subjected to electrical fields; when they're properly aligned, they allow light to pass through them. LCDs use this property by using electrical currents to align the crystals and allow varying levels of light to pass through and create the desired images and colors.

To be more technical, the liquid crystals are sandwiched between two pieces of polarized glass ("substrate"). The fluorescent light source, also known as the backlight, emanates light that passes through the first substrate. The electrical currents then cause the crystals to align, allow varying levels of light to pass through to the second substrate. The end result is a crisp, vivid screen perfect for numerous audio visual projects.