Views: 234 Author: Wendy Publish Time: 2023-08-09 Origin: Site
We are all aware that a liquid crystal display is a passive display; it can only use ambient light. To show patterns or characters, relatively little energy is needed. LCD has become a superior display technology precisely because of its low power consumption and compactness.
A substance that is organic and has both liquid and solid qualities is the liquid crystal material used in liquid crystal displays. Although its rod-like structure is typically stacked in parallel in the liquid crystal cell, an electric field can vary the direction in which it is arranged.
When a voltage is applied to the electrodes, the LCD is in the "ON" state and the long axis direction of the liquid crystal molecules is in the "OFF" state. For positive TN-LCD, the LCD is in the "OFF" state when no voltage is applied to the electrodes, allowing light to pass through the LCD to be in a white state. When the LCD is oriented parallel to the electric field, light cannot pass through it and it is in a dark condition. Different patterns can be displayed by selectively applying a voltage to the electrodes.
Because the liquid crystal's twist angle is greater in negative STN-LCDs, the contrast ratio is better and the viewing angle is wider. Based on the birefringence principle, STN-LCD displays are produced. The font is blue, which turns into a yellow-green mode, and the dominant color is typically yellow-green. The basic color will become gray and mold into a gray color when a violet polarizer is used. The base color will almost become white when used with a polarizer and compensating film. At this point, STN transforms into FSTN, a black-and-white mode. The impact will be greater if the polarizer of the first three modes is rotated by 90 degrees to become a blue mode.
Positive and negative display types are the two types of displays that are typically available on TN LCD/STN screens. To demonstrate the distinctions between positive and negative liquid crystal displays, I'll utilize segment displays and PMOLED displays as examples today.
When the color of the content displayed on the LCD screen is darker than the background color, this is referred to as positive display. Examples include black characters on a gray-white background (FSTN) and black characters on a yellow-green background (yellow-green screen). These screens typically display better in direct sunlight.
A positive display has a bottom that is gray and white/green, characters that are black, and the color of the characters should be darker than the background. There is also a fairly easy way to tell a positive display from a negative display because most of the positive display characters are black. Just now, I made the point that this kind of screen has a nice display effect in the sun. The reason the sunlight is not easily impacted by the characters is precisely because they are black.
In a negative display, the presented content should be lighter in color than the background, for example, white text on a blue background (blue screen) or white text on a black background (VA segment code screen). Given the relative high contrast of these panels, an indoor display effect is necessary. more advantageous than positive.
The majority of the negative display characters are white in color because the LCD screen itself does not emit light; rather, the color of the negative display characters is the color printed by the backlight through the glass, and the backlight is white. This makes it relatively easy to distinguish between the two. The typed text is also white, hence a backlight is required for the negative display in order to show the message.
1. A positive display, with black numbers and letters at the bottom and white (the LCD screen's natural color), i.e., dark text against a light background. Examples include black characters on a gray or white backdrop and black characters on a yellow or green background (yellow/green screen).
2. Negative display: It has a black background with white (the LCD screen's natural color) numbers and letters displayed; in other words, it has light-colored characters on a dark background.Using white text on a black backdrop or white text against a blue background, for example.