LCD displays can be divided into Transmissive LCD, Reflective LCD, and Transflective LCD by the illumination methods.
1. Transmissive LCD
Transmissive LCD is the most common LCD screen, which requires a backlight as the light source and there is no reflective film at the back of the LCD screen.
Advantage: we can see the graphic and character on the screen very clearly if there is only little light. It is such a mature and cheap technology that 90% of LCD screens in the market are transmissive LCD display.
Disadvantage: we can’t see it clear if we are outdoor or there is a strong outside light. It completely relies on the backlight panel as the sole light source and the display effect can’t satisfy our requirement. Furthermore, if we are staring at the screen for too long when we’re watching a movie or playing video games, our eyes will get hurt, even weep.
A Demonstration Transmissive LCD
Transmissive LCD is suitable for indoor environments.
Let us try it indoors.
Second, turn on the LED panel light on the table, we can see the finger clearly.
First, we are only using some LED ceiling panel lights as the light source in our Laboratory and we can see our finger through the LCD.
Let us try it outdoors.
Under the strong sunlight, the letters on the screen become blurred.
2. Reflective LCD
Reflective LCD is the cheapest LCD screen because there is no backlight, which uses light from outside as the light source, such as sunshine or lamplight and there is a reflective film at the back of the LCD screen.
Advantage: we can see it very clear if we are under the sun or there is a strong outside light. We can see it for a very long time and our eyes never get hurt, just like reading a book or magazine because we use natural light.
Disadvantage: we can’t see anything if there is no outside light. It completely relies on light sources outside. More often than not, it is only displaying black and white and can’t meet our requirements in most situations.
A Demonstration Reflective LCD
Reflective LCD is suitable for both indoor and outdoor environments.
Let us try it indoors.
First, we are only using some LED ceiling panel lights as light sources in our Laboratory and we can’t see our finger through the LCD.
Second, turn on the LED panel light on the table, we still can’t see the finger clearly.
Third, turn on the LCD. We can see the letters on the screen clearly.
Let us try it outdoors.
Under the strong sunlight, the letters on the screen become very clear.
3. Transflective LCD
Transflective LCD is the best and most expensive LCD screen, which has a semi-reflective film at the back of the LCD screen. The front light can’t go through the semi-reflective film, but the backlight can go through it. Like sunglasses.
Advantage: it has the advantages of both transmissive LCD and reflective LCD. We not only can see it very clearly in the outdoor like the reflective LCD, but also can see it vividly when we are in a dark place like a transmissive LCD. We see the transflective LCD in the front as the reflective LCD because it can reflect the sunshine, but the LED backlight panel can also supply the light which can penetrate the semi-reflective film at the back of LCD screen.
Disadvantage: it is expensive. Although the technology of transflective LCD is very mature, the cost of semi-reflective film is expensive, it is only the high-class electronic products that would adopt it. It wouldn’t hurt our eyes as much as transmissive LCD, but it can’t protect our eyes as a reflective LCD, either.
A Demonstration Transflective LCD
Let us try it indoors without LED backlight.
Transflective LCD can display with or without LED Backlight and is suitable for both indoor and outdoor environments.
First, we are only using some LED ceiling panel lights as light sources in our Laboratory and we can see our finger through the LCD.
Second, turn on the LED panel light on the table, we can see the finger clearly.
Third, turn on the LCD, we can see the letters on the screen clearly.
Let us try it outdoors without LED backlight.
Fourth, under the strong sunlight, the letters on the screen become very clear.
Let us try it indoors with LED backlight.
Fifth, turn on the LCD and LED backlight, we can see the letters on the screen clearly.
Let us try it outdoors with LED backlight.
Sixth, under the strong sunlight, the letters on the screen become very clear.
