Dot matrix

Most types of modern technology use dot matrices for display of information, including mobile phones, televisions, and printers.

Instead, a single group of vector shapes is used to render all the specific dot matrix patterns needed for the current display or printing task.

All points addressable (APA), or pixel addressable, in the context of a dot matrix on a computer monitor or any display device consisting of a pixel array, refers to an arrangement whereby bits or cells can be individually manipulated, as opposed to rewriting the whole array, or regions such as characters, every time a change is needed.

Impact printers survive where multi-part forms are needed, as the pins can impress dots through multiple layers of paper to make a carbonless copy, for security purposes.

Early 1980s impact printers used a simple form of internal raster image processing, using low-resolution built-in bitmap fonts to render raw character data sent from the computer, and only capable of storing enough dot matrix data for one printed line at a time.

By multiplexing, scanning across rows, quickly flashing the LEDs on and off, it is possible to create characters or pictures to display information to the user.

The primary difference between a common LED matrix and an OLED display is the large, low resolution dots.

The OLED monitor functionally works the same, except there are many times more dots, and they are all much smaller, allowing for greater detail in the displayed patterns.