Selectronic News

TFT Replaces traditional keymat and LCD Display


As users become more and more used to TFT with Touch screens, it is becoming the interface of choice for many applications that previously used a traditional keymat and display solution.

The picture illustrates the solution well: The keymat can be a normal size – leaving an area on the screen for prompts, warnings or other feedback.

How big a TFT is possible?

To be practical the ‘buttons’ must be suitably sized for the intended users. Will gloved hands ever be used? Having said that the smallest size TFT could be a 4.3” part. A 5” would be slightly larger whilst a 7” would enable a large ‘keymat’ area and ample space for detailed messages or further menus. Going to 3.5” or below would leave little room for feedback messages – but could be handled by switching to a different screen as soon as the keymat entry was made.

What Interface is needed?

Smaller TFT’s usually interface directly to a MCU via a parallel port, or even SPI. Larger screens may need a RGB  or even LVDS interface. The best solution depends on the exact configuration under consideration. We can also provide solutions for Android or Linux based products maybe using single board computers.

How do I incorporate it into my enclosure?

A popular way is to use a bonded cover glass over the TFT /Touch Display. This can include a Company Logo, and the front surface is the front of your product. The TFT is then connected to your pcb via a flexi pcb. Many other solutions are possible however and there is an ideal solution waiting for your design!

What can Selectronic offer?

We have a range of TFT displays from 1.4” to over 15” These are all capable of having a Touch panel overlaid onto the front surface. We can select the right display and touch Technology for you and assist in interfacing it to your system – by providing either custom hardware or software as required.

How do I get started?

Please contact us here for a discussion on your project requirements!