LCD (liquid crystal display) screens are ubiquitous today, found in everything from phones and tablets to TVs and computer monitors. Two of the most common types of LCD screens are TFT (thin film transistor) LCD and IPS (in-plane switching) LCD. But which one is better?
How TFT LCD and IPS LCD screens work
To understand the differences between TFT and IPS, we first need to understand how LCD screens work in general. LCD screens contain a backlight, a panel of liquid crystals, and polarizing filters. The liquid crystals can be twisted to block out light and create dark pixels or untwisted to allow light to pass through and create light pixels. The polarizing filters ensure the light coming through is aligned properly.
In a standard LCD screen, each pixel is controlled by a transistor that tells it whether to twist or untwist. TFT LCD improves on this design by dedicating a thin film transistor to each subpixel (red, green, and blue). This gives TFT LCD screens faster refresh rates, better color accuracy, and higher contrast ratios. However, the liquid crystals still have a narrow viewing angle.
IPS LCD was designed to solve the viewing angle problem. It reorients the liquid crystals so they run parallel to the panel rather than perpendicular, allowing light to pass through evenly from all angles. This comes at the cost of lower contrast ratios and brightness compared to standard TFT LCD.
TFT vs IPS – Visual quality
When comparing visual quality, IPS generally provides better viewing angles, while TFT offers better contrast ratios and brightness. Here’s a more in-depth look at how they compare:
Viewing angles
IPS LCD has much wider viewing angles than TFT LCD. The liquid crystals align parallel to the panel rather than perpendicular, so the image looks consistent from nearly 180 degrees. TFT LCD can suffer from color shifting and contrast reduction at viewing angles wider than 60 degrees.
Color accuracy
IPS displays provide better color accuracy overall. The liquid crystals are evenly aligned so the wavelengths pass through cleanly. With TFT LCD, the liquid crystals twist unevenly, resulting in some color shifting and distortion at wider viewing angles.
Contrast ratio
TFT LCD screens have higher contrast ratios than IPS, often around 3000:1 versus 1000:1. The liquid crystals in a TFT screen can twist completely perpendicular to block all light. IPS crystals only tilt, so some light bleeds through even in dark pixels.
Brightness
Similarly, TFT LCD screens can get significantly brighter than IPS, by up to 30%. When crystals are fully perpendicular, the pixels get truly black, increasing the screen’s dynamic range. IPS pixels never get fully black due to light bleed, so the maximum brightness is lower.
Refresh rate
TFT LCDs used to have faster refresh rates, but modern IPS displays have largely caught up. Many current IPS screens match the 120-144 Hz rates of high-end TFT displays. That said, TFT may still have an advantage for high-end gaming monitors pushing 165+ Hz refresh rates.
Backlight bleed
IPS displays are more prone to backlight bleed, where light leaks through the panel around the edges or corners. The liquid crystal alignment allows some light to pass through even when twisted. However, manufacturers have minimized this issue so it is rarely noticeable on modern IPS panels.
TFT vs IPS for different uses
Given their different strengths and weaknesses, TFT and IPS LCD screens are better suited for some uses than others:
Smartphones
Most smartphones today use IPS LCD screens due to their wide viewing angles, color accuracy, and energy efficiency. People often look at their phones off-angle, so IPS provides a better experience. The lower brightness is less of an issue on small screens.
Tablets
Tablets also commonly use IPS LCD panels. Viewing angles are important for sharing a tablet screen. IPS provides excellent color reproduction for viewing photos and videos. The brightness is less crucial on a small, battery-powered device.
Computer monitors
IPS dominates the computer monitor market as well. Professionals who need color accuracy for photo, video, or graphic design work overwhelmingly prefer IPS panels. For general office work and web browsing, IPS viewing angles provide a better experience.
Gaming monitors
Gamers are split between IPS and TFT LCD. IPS provides better colors and viewing angles. But TFT LCD can get brighter with higher contrast for atmospheric horror or space games. For fast-paced competitive gamers, TN panel TFT screens offer the highest refresh rates.
TVs
Most LED LCD TVs use either IPS or VA (vertical alignment) panels. VA panels offer a middle ground with better contrast than IPS but not as good viewing angles as IPS. For large TVs where people view straight on, IPS viewing angles are less crucial than contrast and brightness.
Cost comparison
In general, IPS LCD panels are more expensive to produce than TFT TN panels. Here are a few reasons why:
- IPS manufacturing requires more precision to evenly align the liquid crystals.
- IPS screens require specialized doping chemicals not used in TN TFT LCDs.
- The additional light bleed reduces IPS yields compared to TFT LCD.
As a result of the more complex manufacturing process, IPS screens come at a 10-30% premium in most products. However, costs have dropped steadily so IPS is highly affordable in smartphones and mid-range devices.
Here is a comparison of IPS vs TFT LCD screen prices for equivalent products:
| Product | IPS Price | TFT Price |
|---|---|---|
| 27″ monitor | $180 | $150 |
| 50″ TV | $380 | $330 |
| Smartphone | $200 | $180 |
Power consumption
One advantage of IPS LCD is lower power consumption, especially compared to older CCFL backlit TFT screens. IPS panels require about 10-15% less energy to achieve the same brightness levels. However, with modern LED backlighting, the gap in power efficiency has narrowed between IPS and TFT.
Here’s how the power consumption compares for equivalent monitor sizes and resolutions:
| Monitor Type | Size | Resolution | Power Use |
|---|---|---|---|
| IPS LCD | 27″ | 2560 x 1440 | 28W |
| TFT LCD | 27″ | 2560 x 1440 | 32W |
| IPS LCD | 24″ | 1920 x 1080 | 22W |
| TFT LCD | 24″ | 1920 x 1080 | 25W |
Lifespan and durability
IPS LCD panels tend to have a longer lifespan than TFT LCDs. There are a few reasons for this:
- The liquid crystals in IPS screens degrade more slowly over time.
- IPS pixels require lower voltages to switch states, putting less stress on components.
- IPS displays are less prone to image burn-in or retention issues.
Under normal conditions, a quality IPS monitor can last over 50,000 hours vs 30,000 hours for a TFT monitor. That translates to over 15 years of 8-hour daily use before IPS brightness degrades to 50%.
As for physical durability, both TFT and IPS LCD panels can withstand reasonable shock and vibration. TFT displays may be slightly more vulnerable to damage from pressure due to the perpendicular crystal alignment. But overall durability depends more on the materials and construction of the screen.
Input lag
Input lag refers to the delay between an input like a mouse click and the display reacting with the corresponding change. This is critical for gaming, as lower input lag provides a more responsive feel.
Overall, TFT LCD displays tend to have lower input lag than IPS, thanks to their simpler pixel structure. However, with proper panel optimization, modern IPS monitors can nearly match TFT input lag while maintaining their superior color and viewing angles.
Here are typical input lag figures for IPS vs TFT LCD screens:
| Panel Type | Input Lag |
|---|---|
| TN TFT LCD | 5-10 ms |
| IPS LCD | 10-15 ms |
Screen tearing
Screen tearing occurs when the display’s refresh rate fails to sync perfectly with the graphical frame rate. This results in part of two different frames being displayed simultaneously, creating a torn look.
IPS panels are more prone to screen tearing because of their higher pixel response times. Slow response times mean pixels can’t transition from one frame to the next quickly enough to avoid tearing. Gamers who play at high frame rates may notice this issue more on IPS.
That said, the IPS response time gap has narrowed with panel improvements. Using adaptive sync technology like AMD FreeSync or Nvidia G-Sync also largely eliminates tearing on modern IPS monitors.
Conclusion
While IPS LCD and TFT LCD use different display technologies, both can produce excellent image quality. IPS panels offer better viewing angles, color accuracy and response times for most applications. But TFT displays provide higher brightness and refresh rates preferred by some gamers.
In the end, choosing between IPS or TFT comes down to the intended use. For smartphones, tablets, and non-gaming PC monitors, IPS is likely the better choice for most people. But TFT still delivers advantages in certain gaming scenarios. Thankfully panel improvements have narrowed the gaps between IPS and TFT, so buyers can expect great visuals from either modern display.