Difference between Active Matrix LCD and Passive Matrix LCD
1. Passive Matrix LCD: It uses a grid of vertical and horizontal conductors comprised of Indium Tin Oxide to create an image. Each pixel is controlled by an intersection of two conductors. It represents the off state of LCD i.e the pixel is OFF.
2. Active Matrix LCD: It uses thin-film transistors that are arranged in a matrix on a glass surface. To control the voltage tiny switching transistors and capacitors are used at each pixel location. The active pixel is called so because it has the ability to control the individual pixels and switch them quickly. thin-filmwhich
Difference between Active Matrix LCD and Passive Matrix LCD:
Active Matrix LCD
Passive Matrix LCD
|It uses thin film transistors that are arranged in a matrix on a glass surface. To control the voltage tiny switching transistors and capacitors are used at each pixel location.||It uses grid of vertical and horizontal conductors such that the intersection of two of those conductors allows for controlling a single pixel.|
|The primary constituent is silicon (allows for assigning one transistor for each pixel).||The primary constituent is Indium Tin Oxide (referred to as ITO).|
|Cost is usually higher.||They are less costly.|
|It has a segments best viewed higher response time.||It has a low response time.|
|Used for Full Graphic Displays.||Used for segmented digits or character displays.|
|It allows the viewer much more freedom to choose his/her angle.||They are best-viewed head-on. When the user to either side to view the screen from an oblique angle, it will cause color distortion, dimming, and other problems.|
|Refresh rates are high.||Refresh rates are low.|
|They display higher resolution.||They display lower resolution as compared to active matrix LCD.|
|They have the ability to create gray scale. It also offers 256 levels of brightness per pixel.||They don’t reproduce colors accurately.|
|Active matrix LCDs are used in full-color LCD TVs monitors, cell phones etc.||They are used in calculators display or a digital wrist watches where the display contains a limited number of segment and does not require full color. They are often created for custom applications.|
|The number of rows can be more than 50,grayscale.||The number of rows is limited to 50 only.|
On an elaborative note, passive and active displays also have several types which run down their very own category. For example, passive LCDs may be of the following types:
- Monochrome TN (Twisted Nematic) – here the liquid crystal cells do not require any current to flow past them and automatically work with lower voltages provided by the batteries.
- Monochrome STN (Super-Twisted Nematic) – an extension of TN except with the enhanced ability to allow selective wavelengths of light to pass.
Meanwhile, active displays may be further classified as:
- TN (Twisted Nematic) – note how even passive displays may employ this technology.
- IPS (In-Plane Switching) – only should any electric current flow past the liquid crystals can any 90° alignment happen. Otherwise, the alignment is horizontal and the screen is rendered as opaque.
- SIPS (Super In-Plane Switching) – a refined version of IPS with brighter colours and faster responses.