Display Module Variations
LCDs come in various display modes. The two that are most commonly used are STN and FSTN. STN (super-twisted neumatic) displays provide more contrast than TN (twisted neumatic) displays by twisting the crystal molecules from 180 to 270 degrees. FSTN (filtered super-twisted neumatic) displays use a film compensating layer between the STN display and the rear polarizer. This adds sharpness and better contrast to the display.
Positive Type: Positive type displays provide an image with dark pixels on a light background. Ambient light or a backlight can be used for this type of display. The background is the same color as the backlight.
Negative Type: Negative type displays provide an image with light pixels on a dark background. The backlight must be used for this type of display. The active pixels are the same color as the backlight.
Transflective Transflective polarizers have both reflecting and transmitting properties and offer the most versatile viewing characteristics. They can be viewed in direct sunlight and when combined with a backlight in low light conditions.
Transmissive Transmissive LCDs always require a backlight and provide the highest brightness display. They are best suited for applications where direct sunlight viewing is not involved.
Reflective Reflective polarizers are used in high ambient light environments or whenever sufficient power is not available to drive the backlight.