Types of Monochrome LCDs
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1/11/2026
What are Monochrome LCDs
Monochrome or mono LCDs are actually not limited to 2 colors, sometimes they can be multicolor using screen printing or backlighting color changes, they can even be fully color displays (CSTN). Strictly speaking, we should be passive LCDs which means 1) There is NO transistor (TFT) at each pixel. 2) Pixels are controlled only by row (COM) and column (SEG) electrodes.
Full color LCD so beautiful, why mono LCDs still exist?
There are some irreplaceable use cases for monochrome LCDs, such as ultra-low power consumption; long service life; outdoor / strong sunlight environments; Industrial and medical-grade reliability; cost-sensitive, large-scale mass production; simple information that must be displayed clearly. Some applications are Induction cookers, calculators, electricity meters, car audio systems, thermostats, digital calipers, air-conditioner remote controls, air-conditioner fans, thermometers, blood pressure monitors, chargers, electronic scales, card payment terminals, digital instruments, fuel dispensers, digital voltage testers, water meters, rice cookers, safes, water heaters, massagers, stepper machines, radios, digital clocks, fax machines, etc.
Types of Monochrome LCDs
1. TN LCD
TN LCD (Twisted Nematic Liquid Crystal Display) is one of the earliest and most widely used LCD technologies. In a TN panel, liquid crystal molecules are twisted by about 90 degrees between two glass substrates. When no voltage is applied, light can pass through the twisted structure; when voltage is applied, the molecules untwist, blocking or modulating the light to produce images.
Advantages
- Fast response time → very suitable for gaming and motion-heavy applications
- Low manufacturing cost → cheaper than STN and VA panels
- Low power consumption → efficient for battery-powered devices
- Mature technology → high yield and wide availability
Disadvantages
- Narrow viewing angles → color and contrast shift noticeably when viewed off-axis compared with STN LCD
- Poor color reproduction → limited color depth and accuracy
- Lower contrast ratio compared with STN and VA panels
TN Color is normally black character on gray background or white on black background. With printed color, it can show fixed position colors.
2. HTN LCD
HTN presents High Twisted Nematic. liquid crystal molecules are twisted by about 110 degrees between two glass substrates. It is also Low cost only around 5% higher than TN LCD. Its viewing angle and contrast are a little bit better compared with TN LCD. It has color of black on yellowish background.
3. STN LCD
STN LCD (Super Twisted Nematic Liquid Crystal Display) is an enhanced version of TN LCD. In STN panels, the liquid crystal molecules are twisted by a larger angle (typically 180–270 degrees) compared to TN (~90°). This increased twist improves contrast and multiplexing capability, making STN suitable for displays with more segments or pixels.
Advantages
- Lower power consumption → ideal for battery-powered devices
- Better contrast and viewing angle than TN LCD
- Supports higher multiplexing → suitable for displays with dot matrix
- Low Power Consumption compared with TFT LCDs
- Better Sunlight Readable compared with TFT LCDs
- Low cost compared to TFT LCDs
- Wide operating temperature range → good for industrial applications
Disadvantages
- Slow response time → compared with TN LCD
- Limited viewing angles → compared with TFT LCds
- Poor color performance → often monochrome or limited-color (yellow-green, blue-white)
- Lower resolution and brightness compared to TFT LCD
4. FSTN LCD
FSTN LCD (Film Super Twisted Nematic Liquid Crystal Display) is an improved version of STN LCD. It adds a compensation film to the STN structure to correct phase retardation and color distortion, resulting in better contrast and more neutral display colors (typically black-and-white).
Advantages
- Higher contrast than STN LCD
- True black-and-white display (less color tint than STN)
- Lower power consumption → suitable for battery-powered devices
- Wide operating temperature range → good for industrial and outdoor use
- Low cost compared with TFT LCD
- Full Color Display by adding color filter (CSTN: Color STN)
Disadvantages
- Slow response time → Compared with TN LCD
- Limited viewing angles compared to TFT LCD
- Mainly monochrome → not suitable for color-rich applications
5. Colors of STN and FSTN LCDs
- Yellow Green STN (Dark Blue Characters on Yellow Green Background)
- Blue STN (White Characters on Blue Background)
- Gray STN (Blue Characters on Gray Background)
- Positive FSTN (Black Characters on Gray Background)
- Negative FSTN (White Characters on Black Background)
- FFSTN (Double Compensation Film, Better Contrast Compared with Negative FSTN)
6. LED Backlight and STN LCD matching table
7. VTN LCD
VTN has other names such as VATN, PMVA, GDV , IBN. All means Vertical Alignment.
For more information about VTN, please refer to https://www.orientdisplay.com/vtn/.