Choosing Your Perfect Smartphone Display Tech: From LCD To AMOLED

How LCD Display Works

Let us know a bit about the LCD technology itself. The LCD display is a volatile flat-panel display, meaning that the image displayed by it lasts only as long as the display has power, and the pixels on the screen are electronically refreshed (often multiple times per second) so that they can retain their state (i.e., the image being displayed, even if it is a still image with no change). It uses liquid crystals to control the passage of light, creating images on the screen.

The liquid crystals are crystals that have properties of liquids, or liquid that has properties of crystals. In other words, the liquid crystal is a state of matter (just like the more familiar solid, liquid, and gaseous states), in which the matter can have properties of both a liquid (e.g., it can flow) and a crystal (e.g., it can block or allow polarized light to pass through it).

The LCD screens have a thin layer of the liquid crystal matter, contained between two glass sheets that carry transparent electrodes; and they are held between two polarizing films, one at each side.

As you may recall from your Physics class, light waves (like any electromagnetic wave) are transverse waves, which is the type of waves in which the direction of oscillation of a wave is perpendicular to the direction of its travel. As a common example, you can think of the waves produced in a still pond of water when you throw a pebble in it - the waves move outward (along the water surface), whereas they oscillate up and down (perpendicular to the water surface). Polarization refers to the property of the transverse waves that specifies the geometrical orientation of the oscillations.

Polarized light is the light that has a particular polarization, i.e., it oscillates perpendicular to the direction of its travel but only along one orientation (or direction). Ordinary light (such as the sunlight and the lights from many other sources like flames) is unpolarized. Unpolarized light can be polarized by passing it through a polarizer. This is what the polarizing films (mentioned above) placed on both sides of the LCD screen do - they allow the light waves of a specific polarization to pass through them while blocking the waves of the other polarizations.

The light (which is either the backlight or the light from a reflector in the devices not sporting a backlight) polarized by the back polarizing film passes through the liquid crystals (which are organized in pixels in your smartphone display) of a uniform chirality, which is arranged in such a way that the polarization of light undergoes a rotation of 90°. The front polarizing film (on the viewing side) is usually oriented 90° (crossed) with respect to the back one, and will, therefore, allow the whole light coming out of the liquid crystals to pass through.

And so far, we get nothing special from the liquid crystals, except that they rotate the polarization of the light by 90°, thereby allowing the light to pass through the front polarizing film.

Now comes the role of the electrodes on the sides of the liquid crystal matter. These electrodes are used for applying a controlled electric field to the various portions (say, pixels) of the liquid crystal material, so as to change their polarizing properties. By selectively subjecting the crystals to the varying amounts of electric field, only the polarization of the desired portions of the polarized light from the back polarizing film can be oriented, which means that those portions will pass through the front polarizing film producing varying levels of gray light; the other portions will be dark when viewed.

And for the portions of the light that do get through, the various colors are produced in them by applying the color filters (red, green, and blue) to the subpixels.

Fun Fact: If you wear polarized sunglasses, an LCD display will often be unreadable.

Properties, Pros, and Cons of LCD Displays

LCDs are known for their reliable performance but lack the wow factor of OLEDs.

LCDs operate best in a specific temperature range. In temperatures lower than the range, their response becomes slower, and they are prone to "ghosting" or "smearing" (the retention of an image on the screen as it gets discolored - this is similar to the screen burn-in effect of the CRT displays, but may not be permanent in case of LCDs).

In higher temperatures, you may observe black spots on the screen (or the whole screen may go black), and the prolonged exposure to extreme heat can render the LCD permanently defective.

• Properties:
  • Contrast Ratio: (The contrast ratio is the ratio of the luminance of the full-on and the full-off pixel of the display. The higher the better.) Good, but not as impressive as OLED.
  • Color Accuracy: Decent, but not as vibrant as OLED.
  • Power Consumption: Moderate.
  • Effect on Eyes: Generally comfortable for extended use.
  • Longevity and Durability: Quite durable.
  • Brightness: Fairly bright. Can be used in direct sunlight.
  • Picture Quality: Solid for everyday use. LCDs offer wide viewing angles (except some old or cheaper LCD displays, which have limited viewing angles).
• Pros:
  • Affordable to produce.
  • Good outdoor visibility.
  • Typically long-lasting.
• Cons:
  • Lower contrast and color vibrancy compared to OLED.
  • Can't achieve true blacks.
  • The IPS LCDs (described later in this article) are sometimes vulnerable to "backlight bleeding" - the backlight can leak through the edges, causing uneven brightness and making it difficult to focus on the screen.
  • As explained above, extreme low and high temperatures affect them negatively.
  • They are prone to display "motion blur" (shadows behind fast-moving objects) owing to their slow response times.

Construction of TFT LCD

A transistor is a basic electronic device made of a semiconductor material. It is one of the building blocks of the electronics, and has three or more terminals to connect to an electronic circuit. You can apply a small signal (voltage or current) between one pair of its terminals, and produce a much larger signal proportional to the input signal at another pair. Owing to this property of the transistors, they are used as amplifiers for amplifying the electrical signals and power. Additionally, they can be used as switches for switching these signals on and off.

Of the two types of transistors (viz, BJT - bipolar junction transistor and FET - field-effect transistor), the TFTs belong to the second type (FET). In a FET, three terminals are labeled source, gate, and drain (the fourth being the substrate, which is labeled body), and a voltage applied between the source and the gate (which alters the conductivity between the source and the drain) is used to control the current between the source and the drain.

Trivia: The MOSFET (metal-oxide-semiconductor FET), which typically uses silicon as the semiconductor material, is the most widely used transistor, being 99.9% of all transistors (as of 2018), and the total increases by multiple billions ecery day. It is also the most common type of transistors used in computers and smartphones. However, this is not the transistor used in TFT.

The thin film in TFT refers to the deposition of a very thin layer (the thickness being a fraction of a nanometer) of the semiconductor material (amorphous or polycrystalline silicon in case of LCDs) on a non-conducting substrate (glass in case of LCDs).

In the TFT LCDs, the TFTs are embedded within the flat panel. Each pixel in the display gets its own transistor and capacitor, which actively maintain the pixel state while the other pixels are being addressed. Thus, the TFT LCDs are active matrix LCDs. In fact, virtually all the computer and smartphone LCD and OLED screens use the active matrix technology.

In the active matrix LCDs, re-drawing of the display is very fast. And since the transistor is so small, not only does it allow the light to easily pass through it, but the amount of charge required to control it is also very small.

Properties, Pros, and Cons of TFT LCD Displays

TFT LCDs are older tech with fewer advantages compared to IPS LCD or OLED. The properties ascribed to the LCDs in the previous section are largely also applicable to them.

• Properties:
  • Contrast Ratio: Basic.
  • Color Accuracy: Average.
  • Power Consumption: Can be high.
  • Effect on Eyes: Okay for short use.
  • Longevity and Durability: Not the most durable.
  • Brightness: Varies widely.
  • Picture Quality: Basic, suitable for everyday tasks.
• Pros:
  • Affordable.
  • Gets the job done for basic tasks.
• Cons:
  • Limited color accuracy and contrast.
  • May not be the best for extended use.
  • Durability can be an issue.

Construction of IPS LCD

From the section describing LCDs above, we already know the general construction of the liquid crystal matter between two glass sheets. In the IPS technology, the molecules of the liquid crystals are aligned parallel to the surfaces of glass ("in-plane"). The inner surfaces of the glass sheets are treated, so as to orient the bordering liquid crystal molecules at 90° when no electric filed is applied.

The electrodes here are on a single glass sheet, and the electric field produced between them is parallel to that sheet. So, when an electrical field is applied, the molecules get reoriented while still remaining essentially parallel to the glass sheets.

In this technology, each pixel requires two transistors as opposed to only one in a TFT LCD, and the image produced is not as dependent on the viewing angle. The color reproduction is also better. However, the contrast and the brightness are reduced compared to the TFT LCD.

Properties, Pros, and Cons of IPS LCD Displays

IPS improves on standard LCD with better color reproduction and wider viewing angles.

• Properties:
  • Contrast Ratio: Improved compared to standard LCD, but still the black levels are displayed as dark gray, not pitch black as in case of AMOLED.
  • Color Accuracy: Great.
  • Power Consumption: Moderate.
  • Effect on Eyes: Comfortable for long sessions.
  • Longevity and Durability: Durable.
  • Brightness: Good for most situations.
  • Picture Quality: Impressive, especially in mid-range phones.
• Pros:
  • Excellent color accuracy.
  • Wider viewing angles.
  • Balanced power consumption, about 15% higher than the standard panels.
  • The IPS panels do not show trailing when touched. This is good for touchscreens.
• Cons:
  • Still can't achieve true blacks like OLED.
  • Slightly pricier than standard LCD.
  • Have stable but longer response times than standard LCD.
  • Backlight bleeding (already explained under the section on LCDs above).

Properties, Pros, and Cons of PLS LCD Displays

PLS further improves on the IPS LCD. Here are its properties, pros, and cons:

• Properties:
  • Contrast Ratio: PLS LCDs offer a good contrast ratio, which means you get decent differentiation between light and dark areas on the screen. However, this typically doesn't match the exceptional contrast of OLED or AMOLED displays.
  • Color Accuracy: PLS LCDs provide respectable color accuracy. While they may not match the vividness of OLEDs, they still deliver pleasing, true-to-life colors.
  • Power Consumption: PLS LCDs generally have moderate power consumption. They are more energy-efficient than older TFT LCDs but can't quite compete with the power efficiency of OLEDs.
  • Effect on Eyes: These displays are comfortable for prolonged use. They offer wide viewing angles, so you don't experience color shifts or distortion when viewing from the sides, making them easy on the eyes.
  • Longevity and Durability: PLS LCDs are known for their durability. They can withstand regular wear and tear quite well, making them a reliable choice for smartphones.
  • Brightness: PLS LCDs can achieve good levels of brightness, making them suitable for outdoor use. However, they may not reach the dazzling brightness levels of AMOLED displays.
  • Picture Quality: PLS LCDs offer solid picture quality, with sharp details and good color reproduction. They provide a satisfying visual experience for everyday tasks, from web browsing to watching videos.
• Pros:
  • Wide Viewing Angles: PLS LCDs excel in providing wide viewing angles, ensuring that colors remain consistent even when you're not looking at the screen head-on.
  • Good Color Accuracy: You can expect accurate and pleasing color reproduction, which is essential for a satisfying visual experience.
  • Durability: PLS LCDs are known for their durability and resistance to damage, making them a reliable choice for smartphones that need to withstand daily use.
  • Moderate Power Consumption: Both PLS and IPS LCDs are known for having moderate power consumption. This means that they generally do not drain the battery excessively during regular use.
  • No Backlight Bleed: The PLS panels do not suffer from backlight bleed at higher brightness like the IPS panels do.
• Cons:
  • Not as Energy-Efficient: While more efficient than older TFT LCDs, PLS LCDs are not as power-efficient as OLED or AMOLED displays, which can affect battery life.
  • Limited Contrast: The contrast ratio, while decent, may not match the exceptional levels of OLED or AMOLED displays, leading to less pronounced differences between dark and light areas on the screen.
  • Response Times: The PLS LCD displays, like the IPS LCD displays, have a high response time. Both are not very suitable for gaming.
  • Competing with IPS: PLS and IPS LCDs are closely matched in terms of performance, making it a matter of personal preference rather than one being definitively better than the other.

Which Is Better: PLS or IPS LCD?

The main difference between PLS and IPS LCDs lies in their origins. PLS is developed by Samsung, whereas IPS was pioneered by Hitachi. Both technologies aim to improve viewing angles and color accuracy compared to traditional TFT LCDs; and both offer excellent viewing angles, good color accuracy, and durability.

However, PLS is often considered a close competitor to IPS, offering similar benefits with slight variations in performance. It may be worth considering other factors like the device's brand, software optimization, and pricing when making your decision. In most cases, the differences between PLS and IPS displays are subtle, and either can provide a satisfying smartphone experience.

Super PLS

Super PLS is an enhanced version of PLS (Plane-to-Line Switching) LCD technology, also developed by Samsung, and they share many similarities. However, there are some differences that set Super PLS apart and make it an improvement over the regular PLS LCD displays.

Super PLS builds upon the strengths of PLS displays, offering even wider viewing angles and improved color accuracy, while maintaining the durability and the reliability of PLS displays. The Super PLS displays are known for their excellent outdoor visibility due to enhanced brightness.

PLS LCD displays are often found in mid-range and budget-friendly Samsung devices and some tablets. Super PLS LCDs are often found in higher-end Samsung devices, particularly some of their tablets and larger screens.

How OLED Display Works

The OLED is an LED in which the electroluminescent material is an organic compound (i.e., a chemical compound that has carbon-hydrogen or carbon-carbon bonds). The basic working of OLED is same as that of LED, only the materials used are different (organic). Below, we shall learn about the working of LEDs, which involves more familiar terms.

An electroluminescent material is the one that exhibits electroluminescence, i.e., that emits light when electric current is passed through it or when it is subjected to a strong electric field. Let us now see in brief why some materials are electroluminescent.

As you may recall from your Physics or Chemistry class, an atom consists of a nucleus and some electrons in the various orbitals around it. Since the nucleus has a net positive charge and the electrons are negatively charged, there is a force of attraction between them, while there is a force of repulsion among the electrons themselves. As it happens, the electrons arrange themselves in various shells around the nucleus. These shells have their fixed ranges of electrical potential energy levels.

Conventionally, the electrical potential energy of an atom and any of its electrons is considered 0 when the electron is so far away from the nucleus that it experiences virtually no force from it. Therefore, when it starts approaching the nucleus, the potential energy of the system decreases and becomes negative. Clearly, this means that the innermost (called the first) shell - the once closest to the nucleus - has the lowest (most negative) potential energy range; and as we move outward, the second, the third, etc shells have progressively higher energy ranges.

The maximum number of electrons that any shell can have is fixed; to be precise, the n-th shell can have a maximum of 2.n**2 (that is, twice the square of n) electrons. For example, the first (innermost) shell (for which n = 1) can have a maximum of 2 electrons, the second one can have a maximum of 8, the third 18, and so on. Generally, the innermost shell is filled first, followed by the second shell, followed by the next, and so on.

Since the outermost shell is the farthest from the nucleus, the electrons present in it feel the weakest force of attraction from the nucleus. They are further screened from the nucleus by the force of repulsion from the electrons in the inner shells. It follows that if enough energy were to be supplied to an atom, it will be easiest for an electron in the outermost shell to jump to the next outer shell (which is as yet empty).

In the solid materials, the range of energy levels in the outermost shell occupied by the electrons is known as the valence band, whereas the range of energy levels in the next higher shell (which is as yet empty) is known as the conduction band. The difference of energy level between the top of the valence band and the bottom of the conduction band is known as the band gap. If an electron in the valence band were to be given an energy equal to the band gap, it would jump to the conduction band.

When an electron jumps from the valence band to the conduction band, it is relatively free to move, and thus, conduct electricity. In other words, in general, the smaller the band gap, the easier it is to make a material conduct electricity.

It so happens that the band gap is virtually non-existent in the metals, as the valence band and the conduction band overlap in them. No wonder they are very good conductors of electricity. The band gap is very high in the insulators, giving them their insulating properties. In the semiconductors, the band gap is intermediate, and these are the materials used for making the LEDs.

When sufficient electric field is applied across a semiconductor, its electrons jump from their valence band to the conduction band. When they return, they emit photons (which you can define as the particles of light) of energy equal to the difference between their energy levels in the conduction band and the valence band (i.e., very close to, or you can say slightly higher than, the band gap). This is basically how an LED works.

The emitted light will have a color depending upon the energy levels of the emitted photons, which in turn depends upon the band gap of the material chosen to make the LED. For the materials with very small band gaps, the photons with lower energy levels are emitted, and the light would fall in the IR (infrared) spectrum. In the same way, for the materials with very high band gaps, the emitted light would fall in the UV (ultraviolet) spectrum. For the materials with the intermediate band gaps, we get the visible light of a specific color range.

Trivia: Remote-controllers that we typically use at home use infrared LEDs.

In constructing an OLED display, a film of the organic electroluminescent material is positioned between two electrodes, of which one is transparent so that we would see the light emitted by the diode. As you can see, an OLED (unlike an LED) does not require a backlight; it emits its own light. As such, it can produce pitch dark colors, as opposed to the levels of gray produced by LED. Thus, OLED offers better contrast ratio than LED.

Also, to avoid having to use three different materials to obtain three colors (red, green, and blue), the material is chosen to emit white light, which is then given the colors by passing it through the color filters. However, this also means lower color purity.

Properties, Pros, and Cons of OLED Displays

OLED offers unparalleled contrast and color vibrancy.

• Properties:
  • Contrast Ratio: Outstanding, as each pixel emits its own light.
  • Color Accuracy: Vibrant and true-to-life.
  • Power Consumption: Very efficient.
  • Effect on Eyes: Comfortable, even during prolonged use. However, if the OLED display uses PWM (pulse-width modulation) for controlling the brightness, high rates of flicker can result in eye strain and headaches for people who are sensitive to such flickering.
  • Longevity and Durability: Susceptible to screen burn-in over time.
  • Brightness: Excellent; better than LCDs, especially in low-light conditions.
  • Picture Quality: Stunning, with deep blacks and vibrant colors.
• Pros:
  • Incredible picture quality.
  • Wider viewing angles than LCD.
  • Energy-efficient.
  • Thinner and lighter screens.
  • Much lower response time than LCD.
  • Possible to make flexible OLED displays (as used in foldable smartphones).
  • Possible to make transparent OLED displays (as used in smartphones with optical fingerprint scanners).
• Cons:
  • Susceptible to screen burn-in.
  • Slightly pricier to produce, though the price is expected to drop in future with the advancement in the technology.
  • Typically have lower lifespans than LCDs.
  • Require improved sealing processes, as water damages the organic materials of OLED displays.

P-OLED: The Marvelous Display Tech

The acronym P-OLED might sound like alphabet soup but is the ingredient behind the stunning visuals on your smartphone screen. P-OLED stands for Plastic Organic Light-Emitting Diode. We read about the OLED above. Now, add 'Plastic' to the mix - it refers to the substrate used in P-OLED displays. Unlike traditional OLED displays that use glass, P-OLED uses flexible plastic as a substrate. This flexibility allows for innovative designs, like curved screens, and makes the display more durable.

P-OLED displays have much the same properties, pros, and cons as the OLED displays. They offer the added advantage of flexible design; the plastic substrate allows for flexible and curved displays, enabling innovative and unique designs.

Properties, Pros, and Cons of AMOLED Displays

AMOLED is often used interchangeably with OLED but offers some enhancements. The attributes listed above for OLED also largely apply to AMOLED.

• Properties:
  • Contrast Ratio: Outstanding, like OLED.
  • Color Accuracy: Top-notch.
  • Power Consumption: Very efficient.
  • Effect on Eyes: Comfortable.
  • Longevity and Durability: Can also experience screen burn-in.
  • Brightness: Impressive.
  • Picture Quality: Exceptional, with vibrant colors and deep blacks.
• Pros:
  • Fantastic picture quality.
  • More energy-efficient than OLED, which makes them particularly suitable for the smartphones (and other portable electronic devices).
  • Great for outdoor use.
  • Better (lower) response times than LCDs, resulting in reduced artifacts like ghosting and motion blur.
• Cons:
  • Vulnerable to screen burn-in.
  • Slightly more expensive.

Properties, Pros, and Cons of Super AMOLED Displays

AMOLED is often used interchangeably with OLED but offers some enhancements. The attributes listed above for OLED also largely apply to AMOLED.

• Properties:
  • Contrast Ratio: Outstanding.
  • Color Accuracy: Exceptional.
  • Power Consumption: Very efficient.
  • Effect on Eyes: Comfortable.
  • Longevity and Durability: Susceptible to screen burn-in.
  • Brightness: Excellent, even in sunlight.
  • Picture Quality: Stunning, with vivid colors and deep blacks.
• Pros:
  • Outstanding outdoor visibility.
  • Top-tier picture quality.
  • Power-efficient.
• Cons:
  • Screen burn-in can still occur.
  • Often found in the most pricier phones. AMOLED displays cost higher than the IPS LCD displays.

Dynamic AMOLED

According to Samsung, the Dynamic AMOLED display, first released in 2019, comes with HDR10+ certification, and is the next generation of Super AMOLED technology.

Galaxy S10, Galaxy Note10, Note10+ 5G, and Galaxy Z Flip 5G used Dynamic AMOLED displays.

Dynamic AMOLED 2X

Dynamic AMOLED 2X is the latest and the greatest generation of the Dynamic AMOLED technology, and comes with dynamic tone mapping, which optimizes color and contrast. The "2X" in the name refers to the upgraded screen refresh rate of 120 Hz from from the standard 60 Hz, ensuring super smooth scrolling and highly responsive movements - perfect for fast paced gaming and multitasking.

You’ll find Dynamic AMOLED 2X technology in the latest flagship Samsung phones including Galaxy Z Fold5, Galaxy Z Flip5, and Galaxy S23 and S23+.

Construction and Working Principle of Fluid AMOLED Display

A Fluid AMOLED display consists of several layers, including a thin-film transistor (TFT) array, organic light-emitting diodes (OLEDs), and a flexible substrate. Unlike traditional rigid OLED panels, Fluid AMOLED displays incorporate a flexible substrate, allowing for curved or contoured designs.

The display operates by passing an electric current through the organic materials within each pixel. When electricity flows, the organic compounds emit light, producing the vibrant colors and deep blacks characteristic of AMOLED technology. The flexible substrate enables the display to bend and conform to curved surfaces, offering enhanced design flexibility.

Characteristic Properties of Fluid AMOLED Display

Here are the characteristic properties of Fluid AMOLED displays:

• Vivid Colors: Fluid AMOLED displays are known for their rich and vibrant colors, offering a visually captivating viewing experience.
• Deep Blacks: Each pixel on a Fluid AMOLED display emits its own light, allowing for true black levels by simply turning off individual pixels. This results in superior contrast ratios and deeper blacks compared to traditional LCD displays.
• High Refresh Rates: Many Fluid AMOLED displays feature high refresh rates, such as 120 Hz, resulting in smoother animations and reduced motion blur during fast-paced content.
• Energy Efficiency: AMOLED displays are inherently more energy-efficient than LCDs since they do not require a separate backlight. Pixels emit light independently, allowing for better power management and potentially longer battery life.

Benefits and Drawbacks of Fluid AMOLED Display

Here are some benefits that the Fluid AMOLED displays offer over the regular AMOLED displays and other types of displays:

• Flexibility: The flexible nature of Fluid AMOLED displays enables manufacturers to experiment with innovative form factors, such as curved or foldable screens, leading to unique and aesthetically pleasing designs.
• Visual Quality: Fluid AMOLED displays deliver superior visual quality with vibrant colors, deep blacks, and high contrast ratios, enhancing the overall viewing experience for users.
• High Refresh Rates: The ability to achieve high refresh rates enhances the fluidity of on-screen content, resulting in smoother animations and improved responsiveness, particularly beneficial for gaming and multimedia consumption.

And here are some of their drawbacks:

• Cost: Implementing Fluid AMOLED technology can be costlier compared to traditional LCD displays, potentially leading to higher device prices for consumers.
• Burn-in Risk: Like other OLED displays, Fluid AMOLED screens are susceptible to burn-in, where static images displayed for extended periods may leave ghost images on the screen.
• Durability: While the flexible nature of Fluid AMOLED displays offers design flexibility, it may also make the screen more prone to damage from bending or flexing, requiring additional protective measures.

Construction and Working

The AMOLED display is a layer cake with the following layers:

• Organic Emissive Layer: This is the star of the show! When electricity zaps through it, individual organic pixels emit light, creating those vibrant colors and sharp images for your eager eyes.
• Protective Glass Surface: This layer acts as a shield, safeguarding the delicate OLED components from the outside world. It's like the display's trusty bodyguard, keeping it safe from scratches, dings, and environmental factors.
• Backplane: Now, at the back, we have the backplane. This layer is like the conductor of an orchestra. It controls each pixel's behavior, telling them when to light up and what color to display. Without the backplane, the OLED pixels would just be like rebellious teenagers, doing their own thing and causing chaos!

The third layer, the backplane, consists of TFTs, as we learned above. These TFTs have the following functions:

• Pixel Control: TFTs are responsible for controlling each individual pixel on the display. They act as switches that turn pixels on and off.
• Voltage Amplification: TFTs amplify the small electrical signals sent to them from the display's electronics. This amplification ensures that the OLED pixels receive the necessary voltage to emit light at varying levels of brightness. So, TFTs play a crucial role in brightness control.
• Refresh Rate Management: TFTs also help in managing the refresh rate of the display. In the case of LTPO displays, as we discussed earlier, TFTs play a role in dynamically adjusting the refresh rate.

In the standard OLED displays, LTPS (Low-Temperature Polycrystalline Silicon) and IGZO (Indium Gallium Zinc Oxide) are two of the types of TFTs used.

The LTPS TFTs are made from polycrystalline silicon, and are small but mighty. The LTPS displays are known for their high electron mobility, ensuring fast pixel response times. However, this high mobility makes it challenging to drive extremely low refresh rates, as at the very low refresh rates, LTPS TFTs may struggle to maintain consistent, stable performance.

The IGZO TFTs are made from a semiconductor material, and have moderate electron mobility compared to LTPS. This makes them more suitable for driving extremely low refresh rates, because they are not as "overpowered" as LTPS in terms of speed. However, they are larger in size, so their use results in a lower display density. They are costlier too.

Now, the LTPO displays are based on a combination of oxide materials, including LTPS and IGZO, which are low-temperature processed. This makes them the best of both worlds. It's like having a fuel-efficient car that can switch between eco-mode and turbo-boost.

Properties, Pros, and Cons of LTPO Displays

LTPO is a twist on the OLED display. The attributes listed above for OLED also largely apply to LTPO.

• Properties:
  • Contrast Ratio: LTPO brings those deep blacks and vibrant colors, giving you an impressive contrast ratio.
  • Color Accuracy: Your photos will look as true-to-life as they come, thanks to LTPO's excellent color accuracy.
  • Power Consumption: It's a power-saving champ, especially when you're not in a hurry.
  • Effect on Eyes: No need to worry about eye strain; LTPO keeps your peepers happy.
  • Longevity and Durability: LTPO is less prone to screen burn-in, so your display stays gorgeous for longer.
  • Brightness: It can shine bright like a diamond, so you won't struggle in direct sunlight.
  • Picture Quality: Expect sharp and crisp visuals, making your content pop.
• Pros:
  • Energy-efficient, thanks to dynamic refresh rates.
  • Great for battery life.
  • Stunning color accuracy and contrast.
  • Reduced risk of screen burn-in.
  • Versatile for various usage scenarios.
• Cons:
  • Costlier to manufacture.
  • Limited adoption; found in some flagship devices.

Properties, Pros, and Cons of Retina Displays

Retina Display is essentially a high-res IPS LCD or OLED with Apple's marketing flair.

• Properties:
  • Contrast Ratio: Good.
  • Color Accuracy: Accurate and pleasing.
  • Power Consumption: Moderate.
  • Effect on Eyes: Comfortable.
  • Longevity and Durability: Durable.
  • Brightness: Adequate for most scenarios.
  • Picture Quality: Excellent, with sharp details.
• Pros:
  • Impressive pixel density.
  • Crisp visuals.
  • Apple's optimization for seamless performance.
• Cons:
  • Not as vibrant as AMOLED.
  • Mostly found in Apple devices.

Properties, Pros, and Cons of Notch and Hole-Punch Displays

Notch and hole-punch displays are about aesthetics, not display tech.

• Properties: The properties vary based on the underlying display technology (e.g., OLED, AMOLED, etc), of course.
• Pros:
  • Maximizes screen-to-body ratio.
  • Can be visually appealing.
• Cons:
  • Some find it distracting.

Properties, Pros, and Cons of Foldable Displays

Foldables are about form factor, not display technology.

• Properties: The properties vary based on the underlying display technology, which is typically AMOLED for flexibility.
• Pros:
  • Innovative design.
  • Combines two devices in one.
  • Great for multitasking.
• Cons:
  • Pricey.
  • Durability concerns.

Properties, Pros, and Cons of Always-On Displays

Always-on displays are great for showing limited and important information even when the device is asleep.

• Properties: The properties vary based on the model of the phone. Some phones have true always-on displays; some keep them off until there is a need to show a new message to the user.
• Pros:
  • Quick access to date and time, like a watch.
  • New notifications can be seen without having to unlock the phone.
  • Battery status is easily visible, reminding you to charge the device timely.
• Cons:
  • May sometimes be distracting.
  • Drains the battery.
  • Notifications can be seen by someone without unlocking your phone.

Properties, Pros, and Cons of E-ink Display

E-ink is specialized for reading, not so much for general smartphone use.

• Properties:
  • Contrast Ratio: Excellent for reading.
  • Color Accuracy: Limited (typically grayscale).
  • Power Consumption: Extremely low.
  • Effect on Eyes: Comfortable for reading.
  • Longevity and Durability: Durable.
  • Brightness: Suitable for reading in various lighting conditions.
  • Picture Quality: Focused on text, not multimedia.
• Pros:
  • Unmatched for reading.
  • Exceptional battery life.
• Cons:
  • Limited color and multimedia capabilities.
  • Not ideal for gaming or video.