Alphanumeric LCD Displays

Most Alphanumeric Displays Are Classified As 1, 2, Or 4 Line

The most common type of monochrome LCD modules are known as Alphanumeric LCD Displays or a Character LCD Display. Alphanumeric LCD displays are widely used for the following reasons.

  • These displays are easier to implement than a graphics unit.
  • There are a large number of LCD suppliers that carry drop in equivalent displays.
  • They have been a proven technology for many years.
  • There are built-in standard configurations.

Engineers and hardware designers favor Alphanumeric lcd displays for quick development products. The display contains its own controller driver chip with a character map built into the IC. The character map makes it easy for the design to integrate their software, aka firm ware, into the pre-written software of the LCD module. When the engineer wants to display the letter ‘A’, all they have to do is send a command requesting the capital ‘A’. This is much easier than a graphics LCD module where each dot on the letter ‘A’ needs to addressed. This is a very time consuming activity.

There are a large number of manufactures and electronic distributors that all carry the same model or type of the Alphanumeric LCD displays. I would guess there are over 50 suppliers that can supply the same 16×2 STN, yellow/green 6:00 with LED backlight. They are all interchangeable with each other and the cost difference between suppliers is small. In fact, most of the time OEMs design in a standard Alphanumeric LCD display not to save money or reduce development time, but to make sure there are plenty of backup suppliers.

Construction of a Alphanumeric LCD Display

Character LCD displays have been a proven technology for many years. The most common construction of the Alphanumeric LCD display is known as a COB or chip on Board. This is where there is a PCB attached to the LCD glass. The name Chip on board means that the controller driver chip is located on the back of the Printed circuit board. This type of module handles vibration very well. Also the mounting holes located on the PCB allow an easy secure method to attach the LCD to the customer’s product.

Alphanumeric LCD displays are built in standard configurations such as 16×2, 8×1 and 40×4. The identification of these displays is broken down into the number of characters in each row and then the number of rows. An example of this is a 16×2. That means there are 16 characters in each row. There are two rows of these characters. That means the alphanumeric LCD can display a total of 32 characters at a time.

A character is any letter, capital and non-capital, any number and the punctuation mark, such as period, comma and back slash. The character table built into the micro controller of the LCD can display 255 separate characters. Of course there are different languages, so you can choose a character table that displays English, French, German and many other languages.

Most alphanumeric LCD displays cannot display Chinese and Japanese without the use of a larger character size. This means that a 16×2 that is built to display Chinese will be larger than a 16×2 that is manufactured to display English characters.