What is an IPS Display?

Background

In today's digital world, display technology plays a crucial role in how we interact with our machines. Whether you're browsing on your smartphone, working on your laptop, editing photos on your monitor, or controlling an industrial device, the quality of the display significantly impacts your experience. Among the various display technologies available, IPS (In-Plane Switching) has emerged as one of the most popular and widely adopted options.

But what exactly is IPS technology? Why do manufacturers highlight it as a premium feature? And how does it compare to other display technologies on the market? If you've ever found yourself wondering about these questions while shopping for a new device, or when picking display solution for new embedded project, you're not alone.

IPS technology represents a significant advancement in LCD (Liquid Crystal Display) technology, offering superior color accuracy, wider viewing angles, and consistent image quality compared to older display technologies. Originally developed in the 1990s to address limitations in traditional LCD panels, IPS has evolved through multiple generations to become the preferred choice for professionals, electronic engineers, and increasingly, gamers.

What is IPS Display Technology?

IPS (In-Plane Switching) is a type of LCD (Liquid Crystal Display) panel technology that was developed to overcome the limitations of older TN (Twisted Nematic) displays. At its core, IPS is defined by the way liquid crystals are arranged and manipulated within the display panel.

In an IPS display, a layer of liquid crystals is sandwiched between two glass surfaces. The liquid crystal molecules are aligned parallel to these surfaces in predetermined directions (in-plane). When an electric field is applied, the molecules reorient while remaining essentially parallel to the surfaces, allowing light to pass through and create the image you see on screen.

This horizontal alignment of liquid crystals is the key innovation that sets IPS apart from other LCD technologies. By contrast, in TN panels, the liquid crystals twist and turn perpendicular to the display surface, which leads to limitations in viewing angles and color reproduction.

IPS technology belongs to the broader family of LCD displays, which also includes TN (Twisted Nematic) and VA (Vertical Alignment) panels. All LCD displays use liquid crystals to control light passage, but they differ in how these crystals are arranged and manipulated, resulting in different performance characteristics.

A Brief History of IPS LCD Technology

The journey of IPS technology began in the mid-1990s when display manufacturers were seeking solutions to address the limitations of TN panels, particularly their poor viewing angles and color reproduction. The fundamental concept of IPS was patented in 1974, involving inter-digitated electrodes on one glass substrate to produce an electric field parallel to the glass surfaces. However, practical implementation wasn't achieved until much later.

After thorough analysis and development, details of advantageous molecular arrangements were filed in Germany by Guenter Baur and colleagues, and patented in various countries including the US on January 9, 1990. The Fraunhofer Society in Freiburg, where the inventors worked, assigned these patents to Merck KGaA in Germany. Shortly thereafter, Hitachi of Japan further developed and refined the technology. In 1992, engineers at Hitachi worked out various practical details of IPS technology, including how to interconnect the thin-film transistor array as a matrix and avoid undesirable stray fields between pixels. Hitachi also improved viewing angle performance by optimizing electrode shapes, creating what became known as Super IPS.

The first commercial IPS displays appeared in 1996, marketed by Hitachi as "Super TFT." While these early IPS panels offered superior viewing angles and color reproduction compared to TN panels, they were also significantly more expensive and had slower response times, limiting their initial adoption.

Over the years, IPS technology has seen multiple generations of improvements:

• Super-IPS (S-IPS) - 1998: Improved color shift issues
• Advanced Super-IPS (AS-IPS) - 2002: Higher transmittance and improved contrast ratio
• IPS-Provectus (IPS-Pro) - 2004: Further enhanced contrast ratio
• Horizontal IPS (H-IPS) - 2007: Improved contrast by twisting electrode plane layout
• Enhanced IPS (E-IPS) - 2009: Wider aperture for light transmission, enabling lower-power backlights
• Professional IPS (P-IPS) - 2010: Offering 1.07 billion colors (30-bit color depth)
• Advanced High Performance IPS (AH-IPS) - 2011: Improved color accuracy, increased resolution, and greater light transmission

Today, IPS technology is widely used in displays for smartphones, tablets, monitors, and medical devices. Companies like BOE, Tianma have become major manufacturers of IPS panels, and the technology continues to evolve with innovations like Nano IPS, which uses nanoparticles to enhance color purity and range.

How IPS Technology Works

To understand how IPS technology works, we first need to grasp the fundamentals of LCD displays in general. All TFT LCD displays share certain common elements and principles, with the specific implementation varying between different panel types.

LCD Fundamentals

At the most basic level, an LCD display consists of several key components:

• Backlight: This is the light source behind the screen, typically using LED (Light Emitting Diode) technology in modern displays. The backlight provides a constant source of white light that will eventually form the image you see.
• Polarizing Filters: These are special films that only allow light waves oriented in a specific direction to pass through. LCD displays typically have two polarizing filters with perpendicular orientations.
• Liquid Crystal Layer: This is a thin layer containing liquid crystal molecules suspended in a fluid. Liquid crystals are special materials that can maintain a parallel shape and act as both a solid and liquid.
• Color Filters: These are red, green, and blue (RGB) filters that give each pixel its color.
• TFT (Thin-Film Transistor) Array: This is a grid of tiny transistors that control each pixel individually.

The basic operation of TFT LCD display can be thought of as a window with adjustable blinds. The backlight is like the sun shining behind the blinds, and the liquid crystals act as the blinds that can open and close to control how much light passes through. For detail understanding of what is TFT LCD, please take a look at this post.

How In-Plane Switching Works in LCD Displays

What makes IPS technology special is how the liquid crystals are arranged and how they respond to electrical signals. Below is how it works:

• Initial Alignment: In an IPS panel, the liquid crystals are initially aligned parallel to the panel surface (horizontally) and in the same direction. This alignment blocks light from passing through the second polarizing filter, resulting in a black pixel when no voltage is applied.
• Electric Field Application: When a voltage is applied to a pixel, an electric field is created parallel to the panel surface (in-plane). This field causes the liquid crystals to rotate while remaining in the horizontal plane.
• Light Transmission: As the liquid crystals rotate, they change the polarization of the light passing through them. This allows some light to pass through the second polarizing filter, creating a visible pixel.
• Color Production: The light then passes through red, green, or blue color filters, producing the colored pixels you see on screen.
• Brightness Control: By varying the voltage applied to each pixel, the display can control how much the liquid crystals rotate, which in turn controls how much light passes through and thus the brightness of each pixel.

The key innovation in IPS technology is that the electric field is applied parallel to the panel surface, causing the liquid crystals to rotate while remaining in the same plane. This is in contrast to TN panels, where the electric field causes the liquid crystals to twist and stand up perpendicular to the panel surface.

This horizontal rotation of liquid crystals in IPS panels is what enables the wider viewing angles and better color reproduction that IPS displays are known for. Since the liquid crystals remain parallel to the surface, the optical properties of the display remain more consistent when viewed from different angles.

IPS vs. Other Display Technologies

To truly appreciate the advantages and limitations of IPS technology, it's helpful to compare it with other common display technologies. Each technology has its own set of strengths and weaknesses, making them suitable for different applications and user preferences.

IPS vs. TN Displays: Key Differences

TN panels were the first widely adopted LCD technology and remain common today, especially in budget displays and gaming monitors.

Technical Differences: - In TN panels, liquid crystals twist perpendicular to the display surface when voltage is applied - IPS panels keep liquid crystals parallel to the surface, rotating them horizontally - TN panels typically use 6-bit color depth (with dithering to simulate 8-bit), while IPS panels commonly use true 8-bit or even 10-bit color.

Performance Comparison: - Viewing Angles: IPS significantly outperforms TN, offering up to 178° viewing angles compared to TN's typical 160° horizontal and much narrower vertical angles.

Color Accuracy: IPS delivers superior color reproduction and accuracy, making it preferred for color-critical work.
Response Time: TN traditionally has faster response times (as low as 1ms) compared to IPS (typically 4-5ms in modern panels).
Refresh Rate: TN panels more commonly achieve higher refresh rates at lower costs, though high-refresh IPS panels are increasingly available.
Contrast Ratio: Both technologies offer similar contrast ratios, though neither excels in this area.
Price: TN panels are generally less expensive to manufacture, making them more budget-friendly.

Best Use Cases:
TN: Competitive gaming where response time is critical, budget displays.
IPS: Professional creative work, general computing, gaming where color quality matters more than absolute speed.

IPS vs. VA Displays: Which is Better?

VA panels represent a middle ground between TN and IPS in many respects, with their own unique strengths.

Technical Differences: - In VA panels, liquid crystals are aligned vertically (perpendicular to the substrate) in their resting state - When voltage is applied, the crystals tilt to allow light to pass through - This vertical alignment allows VA panels to block backlight better when displaying black content.

Performance Comparison: - Viewing Angles: IPS offers better viewing angles, though VA has improved significantly and is better than TN.
Color Accuracy: IPS generally provides better color accuracy, though high-end VA panels can come close.
Response Time: VA typically has slower response times (especially in dark-to-light transitions), leading to more motion blur.
Contrast Ratio: VA excels here, offering contrast ratios of 3000:1 or higher, compared to IPS's typical 1000:1.
Black Levels: VA produces significantly deeper blacks than IPS, approaching OLED quality in some cases.
Price: VA panels are typically priced between TN and IPS.

Best Use Cases: - VA: Movie watching, gaming with dark scenes, general use where
contrast is valued - IPS: Professional work requiring color accuracy, applications
requiring wide viewing angles.

IPS vs. OLED: Comparing Premium Display Technologies

OLED (Organic Light Emitting Diode) represents a fundamentally different display
technology that doesn't use liquid crystals or backlights.

Technical Differences: - OLED displays use organic compounds that emit light when electricity is applied - Each pixel generates its own light and can be turned completely off - No backlight is required, unlike all LCD technologies including IPS.

Performance Comparison: - Viewing Angles: Both offer excellent viewing angles, with OLED potentially having a slight edge - Color Accuracy: Both can offer excellent color accuracy, with OLED providing wider color gamuts in many cases.
Response Time: OLED has near-instantaneous response times (<1ms), faster than even the best IPS panels.
Contrast Ratio: OLED offers "infinite" contrast ratio due to perfect blacks, far surpassing IPS.
Black Levels: OLED produces perfect blacks by turning pixels completely off, while IPS suffers from some backlight bleed.
Power Efficiency: OLED is more power-efficient when displaying darker content, while IPS uses consistent power regardless of content.
Lifespan: IPS typically has longer lifespan without image retention or burn-in issues that can affect OLED.
Price: OLED is generally more expensive than IPS, especially in larger sizes.

Best Use Cases: - OLED: Premium entertainment experiences, high-end gaming, applications where perfect blacks are critical - IPS: Professional work requiring consistent performance over time, bright environments, budget-conscious quality displays.

Display Technology Comparison Table

Feature	IPS	TN	VA	OLED
Viewing Angles	Excellent (178°)	Poor, especially Vertical	Good	Excellent
Color Accuracy	Excellent	Poor to Adequate	Good	Excellent
Response Time	Good (4~5ms)	Excellent (1ms)	Fair to good	Excellent
Refresh Rate	Good to excellent	Excellent	Good	Excellent
Contrast Ratio	Good	Adequate	Excellent	Perfect
Black Levels	Good	Adequate	Very Good	Perfect
Brightness	Very Good	Good	Good	Good
Power Consumption	Higher	Lower	Moderate	Content dependent
Lifespan	Excellent	Excellent	Excellent	Good (burn-in risk)
Price	Moderate to High	Low	Moderate	High
Best for	Professional work, general use	Competitive gaming, budget	Movie, contrast focused	Premium experience

Advantages of IPS Displays

IPS TFT LCD technology has gained widespread popularity for good reason. Let's explore the key advantages that make IPS panels a preferred choice for many users and applications.

Superior Viewing Angles in IPS LCD

One of the most significant advantages of IPS technology is its exceptional viewing angle performance. IPS displays maintain color accuracy and brightness even when viewed from extreme angles — up to 178 degrees both horizontally and vertically. For example, this 12.1 inch IPS TFT LCD has 88°/88°/88°/88° viewing angles. This means you can look at an IPS screen from almost any position and still see an accurate representation of colors and content. There's minimal color shifting, contrast reduction, or brightness drop-off as you move to the side, above, or below the optimal viewing position.

This advantage is particularly valuable in several scenarios: - Collaborative environments where multiple people need to view the same screen simultaneously - Professional settings where accurate color perception is needed from different positions - Home entertainment where viewers may be seated at various angles from the display - Mobile devices that are frequently viewed from different orientations and positions.

Color Accuracy and Reproduction in IPS Displays

IPS panels are renowned for their superior color performance, making them the standard choice for color-critical work. This advantage stems from several factors:

• Color Depth: Most IPS panels offer true 8-bit color (16.7 million colors), with professional models supporting 10-bit color (1.07 billion colors).
• Color Consistency: Colors remain accurate across the entire screen, without the shifts or inconsistencies found in other panel types.
• Color Gamut: Modern IPS displays can cover a wide color gamut, with many professional models supporting 100% sRGB, 98% Adobe RGB, and even 95% DCI-P3 color spaces.

• Color Accuracy: When properly calibrated, IPS displays can achieve Delta E values below 2 (where values under 2 represent color differences imperceptible to the human eye).

This color performance makes IPS displays ideal for: - Photographers editing and
evaluating images - Graphic designers creating visual content - Video editors working with color grading - Digital artists requiring accurate color representation - Print professionals needing to match digital and physical colors - Anyone who values accurate and vibrant color reproduction.

Consistent Image Quality

IPS technology provides remarkable consistency in image quality across the entire display. This means that brightness, contrast, and color appear uniform from edge to edge, without the vignetting or inconsistency that can plague other panel types.

This consistency is particularly important for: - Professional work where precision is required across the entire canvas - Split-screen multitasking where content in different screen regions needs equal clarity - Content creation where subtle details must be visible throughout the frame - Quality control applications where detecting minor variations is critical.

Improved Response Times in Modern IPS Panels

While early IPS panels were criticized for slow response times, modern IPS technology has made significant strides in this area. Today's high-performance IPS displays offer response times as low as 1-2ms (gray-to-gray), making them viable even for competitive gaming.

This improvement addresses what was historically one of the few weaknesses of IPS technology, expanding its suitability to applications requiring fast pixel transitions, such as: - Action-packed gaming with fast-moving content - Sports broadcasting and viewing - Video playback with rapid scene changes - Animation and motion graphics.

Disadvantages of IPS TFT Displays.

While IPS technology offers numerous advantages, it's important to understand its limitations as well. No display technology is perfect for every situation, and IPS has several drawbacks that might make it less suitable for certain applications or users.

Higher Power Consumption

IPS displays typically consume more power than some alternative technologies,
particularly TN panels. This increased power consumption stems from several factors:

• The horizontal alignment of liquid crystals in IPS panels requires more power to maintain and adjust.
• IPS displays often need stronger backlights to achieve the same brightness levels as TN panels. Because IPS TFT LCD's aperture ratio is lower.
• The more complex pixel structure requires additional power for operation.

This higher power consumption is most noticeable in: - Battery-powered devices like hand-held instruments, laptops and tablets.

Studies suggest that IPS displays consume approximately 15% more power than equivalent TN displays, though this gap has narrowed with advances in energy-efficient backlighting technology.

Higher Manufacturing Costs

The higher cost is due to several factors:

• More complex pixel structure requiring additional manufacturing steps.
• Higher precision requirements in the manufacturing process.
• Greater quality control needs to ensure color accuracy and consistency.
• Additional materials needed for the panel construction.

Lower Contrast Ratios Compared to VA and OLED

While IPS panels offer good overall image quality, they typically have lower contrast ratios compared to VA panels and significantly lower contrast than OLED displays. A typical IPS panel achieves a static contrast ratio of around 1000:1, while VA panels can reach 3000:1 or higher, and OLED displays offer theoretically infinite contrast.

The lower contrast is primarily due to IPS panels' inability to completely block backlight when displaying black content, resulting in blacks that appear more like dark gray, especially in dark viewing environments.

IPS Glow and Backlight Bleed

IPS displays are susceptible to two related phenomena that can affect image quality, particularly in dark environments:

IPS Glow: This appears as a glow or shine that's visible when viewing dark content, especially from an angle. It's an inherent characteristic of IPS technology, resulting from light passing through the panel structure. The glow typically appears as a silvery or yellowish illumination in the corners of the display.

Backlight Bleed: This occurs when light from the backlight leaks around the edges of the panel or through certain areas, creating uneven illumination. While this can affect any LCD technology, it's often more noticeable on IPS panels due to their already limited ability to display deep blacks.

These issues are most problematic for: - Users who frequently view dark content in dim environments - Movie enthusiasts watching letterboxed content with black bars - Applications requiring perfect uniformity across the screen - Critical evaluation of shadow detail in images or video.

Historical Issues with Response Times

While modern IPS panels have made significant improvements in response times, historically this was a major weakness of the technology. Even today, budget and mid-range IPS displays may exhibit:

• Slower pixel transition times compared to TN panels.
• Motion blur during fast-moving content.
• Ghosting artifacts in high-speed gaming or video Higher input lag in some implementations.

Applications and Use Cases for IPS Displays

IPS panel technology finds application across a wide spectrum of devices and use cases, thanks to its versatile performance characteristics. Understanding where IPS display excels can help you determine if it's the right choice for your specific needs.

Professional Applications

IPS monitors have become the standard in many professional fields where visual accuracy is paramount. Their color accuracy, consistency, and wide viewing angles make them ideal for various professional applications: Graphic Design and Digital Art; Photography and Video Editing; Medical Imaging; CAD/CAM and Engineering; Mobile Devices, and so on.

General Computing and Office Work

For everyday computing and office applications, IPS offers several advantages:

• Reduced eye strain during long work sessions due to consistent colors and brightness,
• Better readability of text and spreadsheets from different positions at a desk
• More accurate representation of colors in presentations and documents Improved visibility in brightly lit office environments

These benefits make IPS displays popular in corporate environments, home offices, and educational settings where display quality impacts productivity and comfort.

Industry-Specific Applications

Beyond consumer and professional creative uses, IPS displays serve specialized roles in various industries: Retail POS & Signage; Manufacturing Control; Transportation; Agriculture; Forestry, etc.

These specialized applications leverage IPS technology's unique combination of viewing angle performance and color accuracy.

Future of IPS Technology

Despite being a mature technology with decades of development behind it, IPS display technology continues to evolve and improve. Understanding current trends and future directions can help you make more informed decisions about display purchases and new project designs.

Current Research and Development Trends

Several key areas of research are driving the evolution of IPS technology:

Improve Response Times and Refresh Rates
Manufacturers continue to push the boundaries of how quickly IPS panels can change states: - Sub-1ms response times are becoming more common in premium gaming displays - Refresh rates continue to climb, with 360Hz IPS panels now available and higher rates in development - Overdrive algorithms are becoming more sophisticated, reducing artifacts while maintaining speed - Motion blur reduction technologies like backlight strobing are being refined for IPS implementations.

Enhanced Contrast Performance
While contrast has traditionally been a weakness of IPS technology, several approaches are improving this aspect: - Advanced panel designs with better light blocking capabilities - Improved polarizer technologies that reduce light leakage - More sophisticated local dimming implementations with greater zone counts - Hybrid backlighting approaches that combine mini-LED with IPS for better contrast.

Power Efficiency Improvements
Reducing power consumption remains a priority, especially for mobile applications: - More efficient backlight technologies, including optimized LED designs - Panel structures that require less power to maintain crystal alignment - Improved light transmission requiring less backlight power - Adaptive brightness and power management technologies.

Integration with Other Technologies

IPS is increasingly being combined with complementary technologies to enhance overall performance:

Quantum Dots
Quantum dot technology enhances color performance by converting backlight wavelengths: - Wider color gamut approaching or exceeding 100% DCI-P3 - More precise color control and better color volume - Improved energy efficiency through better light utilization - Enhanced HDR performance with more vibrant colors at high brightness levels.

Mini-LED Backlighting
This backlighting technology uses thousands of tiny LEDs arranged in dimming zones: - Dramatically improved contrast through more precise local dimming - Higher peak brightness for HDR content - Better uniformity across the panel - Reduced blooming and halo effects compared to traditional local dimming. When combined with IPS panels, mini-LED backlighting addresses one of IPS's primary weaknesses while maintaining its viewing angle and color advantages.

Advanced Coatings and Optical Films
New surface treatments and internal optical components enhance various aspects of performance: - Anti-reflection coatings that reduce glare while preserving image clarity - Optical films that improve viewing angles even further - Polarizer enhancements that improve contrast and reduce IPS glow - Blue light filtering technologies for reduced eye strain.

Frequently Asked Questions About IPS Displays

Q: Is IPS better than other technologies?
A: Not necessarily "better" in every single way, but different, with specific strengths. IPS excels in wide viewing angles, superior color accuracy compared to older technologies like TN. However, other technologies like VA might offer higher contrast ratios, and OLED provides perfect blacks. The "best" technology depends on your specific needs – if color fidelity and viewing angles are top priorities, IPS is often the preferred choice.

Q: Are IPS displays too slow for gaming?
A: Yes, modern IPS monitors are excellent for gaming. While early IPS panels had slow response times that caused motion blur, today's gaming-oriented IPS displays offer response times as low as 1ms and refresh rates up to 360Hz. They provide a great balance of speed and visual quality, with better color reproduction than TN panels. Many professional gamers now use IPS displays in competition.

Q: IPS glow means a defective panel?
A: Not usually. "IPS glow" is a characteristic phenomenon of IPS technology where a faint glow can be seen in dark areas, especially from an angle or in a dark room. A small amount of glow is normal for IPS panels. However, if the glow is excessive, very uneven, or distracting, it could indicate a quality control issue or a potential defect, but mild glow is expected.

Q: Can IPS displays be used outdoors?
A: Yes, but with limitations. Standard IPS displays rely on a backlight, and bright sunlight can easily overpower this backlight, making the screen difficult to see. For outdoor use, you would ideally need an IPS display with very high brightness levels (measured in nits) and often an anti-glare or anti-reflective coating to improve visibility in bright conditions. They are generally more visible outdoors than many other LCD types due to their brightness capabilities.

Q: What are IPS displays more expensive?
A: IPS displays tend to cost more than alternatives like TN panels for several reasons: - More complex manufacturing process requiring greater precision - Additional materials and components in the panel structure - Higher quality control standards to ensure color consistency - Licensing fees for the technology (in some cases) - Market positioning as a premium display technology. However, as manufacturing has scaled up and technology has matured, the price premium has decreased, making IPS more accessible across all market segments.