The simplest and most economical solution for displaying numbers. Seven-segment displays are available in a wide variety of sizes and colours. They offer good visibility even from a distance, as the numbers are extremely bright, and they are very low cost.
These particular displays are formed of 5×10 pixel areas positioned next to one another. There are various formats and colours. They are low cost and can display numbers and letters, but do not allow icons, drawings or complex menus to be displayed.
Graphic displays feature a continuous matrix of pixels which provide a clearer and more immediate view of the information required by the user; they can display graphics, machine summaries, operating diagrams, animations and anything else required to more clearly communicate the data to the user.
Various formats with different resolutions are available, from the smallest 122×32 pixel up to 640×480.
The larger sizes, generally 128×240 and above, can be combined with a touchscreen interface
The use of colour allows more advanced graphics to be displayed, thus increasing the clarity of the information shown. With the addition of suitable hardware it is possible to display images, films and any other multimedia content.
They are available in various formats and resolutions: from the smallest 2.4″ and 3.5″ 320×240 resolution, through 4.3″ 480×240 models, right up to 5.7″ and 7″ models with 800×600 resolution.
Resistive touchscreens operate via the principle of electrical resistance: pressing on the screen creates a contact between two electrical conductors.
The device tracks the positional co-ordinates of the contact and communicates this data to the operating system. They can be combined with monochrome or colour graphic displays.
Capacitive touchscreens generate a flow of electrons through the surface of the display: when a capacitive object, such as a human finger, touches or even brushes the screen, the flow of electrons is distorted. The device detects this distortion via the sensors positioned in each corner of the display and assigns co-ordinates to the point touched. Reactivity is significantly better than with the resistive solution, offering improved ease of use.