power consumption of TFT LCD
summary
The power consumption of tft screen is composed of lcd panel, led backlit and touch screen, among which the power consumption of led backlit accounts for more than 90% of the whole tft screen, especially the high-brightness display module, in addition to the power consumption of led backlit, other accessories can neglect.
LCD display module’s application in all walks of life is becoming more and more widespread, when you start to design and plan products, or in the existing project to upgrade the use of different displays, in addition to the form factor needs attention, power consumption also needs special attention, especially different sizes of different resolutions of the display, their power consumption differences are relatively large. The main impact of LCD power consumption are size, resolution, brightness, display mode.
TFT LCD Module circuit
LCD Size
LCD size mainly affects the resolution and the size of the backlight, LCD power consumption is mainly from the backlight, most of the different sizes of products with different resolutions, but in some standard resolutions such as HD, FHD will appear the same products, such as 5-inch HD, 5.5-inch HD, 6-inch HD, etc.. Custom LCDs require higher costs, and choosing products that have been mass-produced is an economical and quick choice.
Resolution
The impact of resolution on the display is the transmittance, the higher the resolution of the same size LCD, the lower the transmittance, because the higher resolution LCD has more pixels in the same area, which means more lines blocking the light penetration. So when you replace the LCD with a higher resolution, you have to consider the increase in power consumption even if the brightness remains the same.
Driver IC circuit
BLU circuit
Brightness and other optical parameters
The brightness of an LCD is provided by the backlight. Higher brightness means more LED beads are needed, for example, a 5.5″ FHD LCD to achieve 260lux-300lux brightness, the matching backlight needs 14 LED beads, if higher brightness is needed more LED beads should be added. Color gamut is another parameter that affects the brightness, the higher the color gamut the lower the transmittance will be, also need more LED beads, power consumption will increase more.
Display mode
Different display modes of LCD monitors due to differences in working principles, so the power consumption in the same working state is also different, for example, TN display mode in the non-working state for white, so called normal white, while IPS display mode.in the non-working state for the black, so was for the normal black, when the two display modes of LCD monitors at the same time to display the black screen when there is a difference in power consumption.
conclusion
The main source of power consumption of the whole LCD is the backlight, the power consumption of individual LCD devices is actually not high, the logic power consumption of HD resolution display is 120mW, the logic power consumption of FHD resolution display is about 150mW, but the power consumption of the backlight matched with them is more than 800mW, if higher brightness is needed, then the power consumption of the backlight will further increase, so In the beginning of the product design to display the matching power supply circuit and power supply or battery.
