Mono displays are a type of display, just like TFT displays and OLED displays. Mono displays can be recognized by their mainly black and white image. They are often smaller in size and used in for example electronic shelf labeling in supermarkets or desk phones.
Below we explain the difference between three mono display technologies, how they work and what the advantages are of mono displays over TFT displays.
Passive vs Active Displays
Compare both technologies
There are multiple differences between passive and active displays. The main difference is the way they work and this also makes them suitable for different applications and environments.
Mono displays are passive displays. Continue reading to find out the difference between passive and active displays en compare their key features and qualities.
A passive LCD display uses a simple matrix to supply electrical charge to a specific pixel. Creating this matrix is quite a difficult process.
It starts with two glass layers, called substrates. One substrate has columns and the other one rows and are made of a transparant conductive material. This is usually indium-tin oxide. The rows and columns are connected with integrated circuits that regulate when a charge needs to be send to a specific row or column. Between the two glass substrates are the liquid crystals. A polarizing layers is added to the outside of each glass substrate. The location where a row and column intersect is called a pixel. When a charge is send to this intersection, the crystals at this location turn around to let light pass through.
A pixel of a passive display is either on or off. It cannot be opened partially to create grey scales. Next to black and white, a passive display pixel can also be one colour. This is realized by adding a coloured filter (in one colour) to the pixel.
|● Little control. Pixels are either open or closed|
|● Black/white only. Sometimes one colour|
|● High resolution|
|● Slow response time|
|● Low power|
|● Colours less bright|
|● Limited to 50 rows|
|● Each subpixel not individually controlled|
Active displays use so called thin film transistors (TFT). To simplify, TFTs are small switching transistors forming a matrix on a glass layer, controlling each pixel individually. Switching a TFT on, activates the corresponding pixel.
Adding an actively switching layer to the display, reduces cross-talk between adjacent pixels and improves response time. (Cross talk: when an electrical charge meant for one pixel, influences the adjacent pixel).
By slowly increasing the amount of electrical current, it is possible to create grey scale colours. A combination of red, green and blue colour filters and the variation in light intensity allow an active (TFT) display to display millions of colours.
|● A lot of control. Pixels can be partially open/closed|
|● Greyscale and millions of colours possible|
|● Very high resolution|
|● Quick response time|
|● More power needed|
|● Very bright colours|
|● Unlimited number of rows|
|● Each subpixel individually controlled|
Mono Display Technologies
Segment, Character and Graphic displays
Segment mono displays
A segment display can display both numbers and letters which are made up of segments, not pixels. A segment can also make symbols like plus and minus signs, units of measurement and custom icons. Each symbol is counted as one segment.
A segment mono display is restricted to displaying numbers, Roman letters and a set number of symbols. When the display needs to show something other than this, a character of graphic display might be a better choice. When the symbols need to be on a different location on the display, a new display will need to be made.
Segment displays are often used in devices like alarm clocks. They are easy to maintain and cost effective to develop.
Character mono displays
Character mono displays are also known as dot matrix displays. These displays display a number of rows with characters. They usually have 1 to 4 rows with 16 to 40 characters on each row. When a character display consists of 2 x 24 characters, a row cannot be longer than 24 characters. The characters to be displayed can be placed on any of the 24 character spots.
Each character consists of 5 x 8 dots and are individually controlled. A character can be a number, Roman letter, foreign letter or limited number of symbols.
Character mono displays are often used when more characters than those of the Roman alphabet need to be displayed. They are relatively easy to use and less costly than graphic displays.
Graphic mono displays
Graphic mono displays offer users a great amount of flexibility. They consist of pixels aligned in rows and columns. Each pixel can be individually controlled to display text, graphic images or a combination of both.
These graphic mono displays are ofted used in applications that require full control of the entire display. They are often a little bigger than other mono displays, more expensive and more complex to use. But on the other hand can display much more complicated and detailed images.
Find out which mono display technology fits your application
email@example.com or +31 (0)251 7002 82
QUESTIONS OR ADVICE?
Talk to a product specialist
firstname.lastname@example.org | 0251 7002 82