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What is In-Plane Switching (IPS)?
In-Plane Switching or IPS refers to the panel for the Liquid Crystal Displays or LCDs where the layer of crystals is placed between two glass surfaces arranged in a preset direction and in parallel to the surfaces, and hence the name ‘In-Plane.’
From the technical point of view, in IPS technology an electric field is applied on the crystal molecules to reorient them but maintaining the parallel placement all the time to the surface to produce the image.
- IPS technology solves the issue of offering a wider viewing angle and higher quality color production than the TN or Twisted Nematic field effect matrix LCDs.
- The name In-Plane is derived from the arrangement of the liquid crystal layer which is in parallel to the two surfaces between which it is sandwiched.
- The liquid crystals here are always in a horizontal orientation and the molecules rotate in-plane or parallel when an electric current or voltage is applied on them.
- The modern IPS panels come with varied and more useful features that make them suitable for a wide range of applications.
Understanding In-Plane Switching (IPS) Technology
IPS is actually a type of LCD or LED (which is also a form of LCD) display panel technology and are typically characterized by their high quality color production with deeper blacks and wider viewing angles in comparison to TN and VA or Vertical Alignment panels.
This technology is a bit more expensive than the others. However, it offers better viewing angles due to the specific arrangement of electrodes in them as well as the preset orientation of the liquid crystal layers.
This LCD screen technology was developed in the mid 1990s by Hitachi and is now used extensively in iPads and several Android tablets.
It is the horizontal orientation of the liquid crystals inside and the parallel movement of the molecules that allows light to pass through them in order to create an image and display them on the screen.
It is the wide angle viewing that makes the IPS displays most suitable for using in computer monitors and televisions.
In this particular technology the axes of transmission of two linear polarizing filters are in the same direction.
The inner surface of the glass plate is treated to line up the liquid crystal molecules at the edges at a right angle. This gives the layer the 90-degree TN structure.
The liquid crystal layer between the two glass surfaces is merely a few micrometers thick and therefore is very small compared to the distance between the two electrodes that are arranged differently.
Since all these are on one single glass plate and are in the same plane, an electric field is typically generated parallel to the plate.
At this point, you must also keep in mind that buying an IPS display alone may not display truly accurate colors. You will have to calibrate the display for that.
However, these panels need more power than the other panels to operate and are expensive.
One significant challenge is blocking out the backlight for displaying better blacks. This may sometimes produce uneven blacks or even washed out images.
Even if local dimming is used to improve the production of blacks, it may result in ugly ‘blooming’ and ‘ghosting’ at the edges of the images of the bright objects.
Features of IPS Technology
The most distinctive feature of the IPS screen technology is the horizontal arrangement of the liquid crystals between the two transparent glass surfaces.
Some other notable features of IPS technology include:
- The two strip electrodes that creates electrical fields to switch the molecules of the liquid crystals
- An inhomogeneous electric field in the first estimation that is arranged in parallel to the substrate surface and
- The unique arrangement of the two electrodes between the liquid crystals and the orientation layers.
All these features facilitate the IPS switching mode in parallel to the two glass plates and according to the substrate by 90 degrees in the same plane, which is why it is called ‘In-Plane.’
The IPS panels now come with different useful features as well such as:
- Bright backlights
- Faster response times and
- High refresh rates
All these features of the IPS screen technology provide several advantages apart from wider viewing angle such as:
- Higher color consistency
- No tailing or lightning when touched
- Clear images and
- Stable response time.
The unique IPS switching mode helps in creating a much reduced viewing angle dependence without needing any extra compensation film.
This is the key feature of the IPS screen technology that makes it so attractive for several applications.
What Does an IPS Panel Do?
The IPS panels primarily leverage the liquid crystal molecules placed in between the two glass surfaces arranged in parallel to generate rich colors. These panels also overcome the limitations in terms of wider viewing angle and color quality of the TN panels.
This is the result of the specific shifting pattern of the molecules of the liquid crystals and it all depends on its working process that needs to be explained further in steps as follows:
- The liquid crystal molecules align them with their long axis parallel to the electric field applied on the molecules
- These molecules having a positive dielectric anisotropy are polarized by the polarizer when light enters in the OFF state
- The polarization axis of the light passing through is rotated by the Twisted Nematic liquid crystal layer by 90 degrees thereby obstructing the light from passing through the polarizer.
On the other hand, in the ON state, an adequate amount of voltage is used between the electrodes and an electrical field corresponding to it is generated at the same time.
This realigns the molecules of the liquid crystals so that light can pass through the polarizer.
Therefore, this arrangement includes two specific states namely V OFF and V ON and the arrangement is as follows.
In the Voltage OFF state:
- Non-polarized light passes through the polarizer to reach the two uncharged TFT electrodes
- The liquid crystals are in between the two surfaces and
- The upper surface contains the orientation layer, the glass substrate and the analyzer in that order.
In the Voltage ON state:
- The un-polarized passes through the polarizer to the two TFT electrodes with different charges
- An electrical field is created due to the difference in charges in the electrodes within the liquid crystals present between the two surfaces and
- The polarized light passes beyond the orientation layer and through the glass substrate and analyzer to create the image.
There are also other methods of implementation using a different arrangement of the liquid crystal molecules in which no twisting of the OFF state is required.
Since both the electrodes reside on the same substrate, more space is taken up by them in comparison to the electrodes in a TN matrix, which, in turn, reduces the color and brightness.
In the super IPS method, better color production and response times are offered which is more suited for graphics designing and other applications in which more consistent and accurate color reproduction is essential.
IPS Display vs LED
- IPS or In-Plane Switching displays uses more power than LED or Light Emitting Diode displays
- IPS has a much longer response time in comparison to the LEDs
- IPS offers much better screen consistency and more accurate colors in comparison to the LEDs
- The LEDs offer better contrast ratio, image quality and brighter screen than IPS displays
- IPS offers wider viewing angles with no shifts or distortion in color
- In IPS panel the liquid crystals are arranged in parallel to the substrate plane while an arrangement of diodes are used in LEDs
- The IPS panels are much more compatible in comparison to the LEDs and
- More heat is produced due to higher power consumption by the IPS panels in comparison to the LEDs.
IPS vs LCD
- The LCDs use CCFLs or Cold Cathode Fluorescent Lamps to light the screen up while the IPS displays uses the liquid crystal molecules placed in between two glass surfaces
- The IPS panels offer a much wider viewing angle and many colors than the LCDs
- The IPS displays offer much higher contrast than the LCD panels
- The clarity of color is much better in the IPS displays than it is in the LCDs and
- The aspect ratio of the IPS panels is much wider in comparison to the aspect ratio of the LCDs.
IPS vs OLED
- The Organic Light Emitting Diode screens are much more power efficient than the IPS displays
- The IPS displays are much thicker in comparison to the OLED screens
- IPS panels offer good color gamut and accuracy but the OLED screens offer excellent color gamut and more accuracy
- There is no image burn-in issue in the IPS panels but OLED screen may suffer from image burn-ins
- IPS panels offer wider viewing angles up to 178o overall but OLED screen offer 70o viewing angles from the center of the screen to extreme wide
- The black levels of the IPS panels are not perfect but that of the OLED displays are excellent and more perfect
- Contrast seems to be limited in the IPS screens than in the OLED screens
- There is a possibility of backlight leakage or bleeding in the IPS panels as opposed to the OLED screens
- The resolution in the OLED screens is much better and higher than the IPS panels being 3840 x 2160 pixels or 4K as opposed to 2560 × 1449 or Quad High Definition of the IPS displays
- The IPS screens have a slower response time in comparison to the OLED displays
- The Organic LED displays do not use backlighting as the IPS LCD panels
- The IPS panels support responsive gaming but OLED displays are better for dark games due to their true black rendering
- The brightness of the IPS displays is high as opposed to low to medium brightness of the OLED displays
- The OLED displays may get dimmer with age due to the use of organic substances in them that decay over time as opposed to the IPS panels and
- The layers of the OLED panels are less complex and more flexible enough to design even foldable panels as opposed to the IPS panels that are more complex and less flexible.
The IPS technology is very useful today as you can see very clearly from this article and therefore has a wide range of applications which is not restricted to computer monitors.
Though it may not be as good as an OLED display, considering the pros and cons, it is worth making an investment into.