Pairing an e-paper display with location sensors and low-power wireless technology enables the creation of in-vehicle displays for use on production lines

Production lines revolutionised manufacturing, enabling factories to turn out high volumes of identical products quickly and economically. But as consumers’ desire for customisation has grown, so has the complexity around production lines. Those working in or overseeing manufacturing facilities now need to cater for numerous subtle differences between items as they come through. And while much of the work is automated, humans still play an important role, including in car manufacturing.

For quality assurance purposes, it’s crucial that production line workers have easily accessible instructions available for each vehicle as it passes through their area. These should be attached to the car in question, somewhere easy to read. This will ensure optimal clarity for the human operator, and remove any ambiguity over which vehicle the instructions apply to.

Having the entire spec of an individual vehicle visible at all times isn’t necessarily feasible or particularly practical. There’s a lot of information required to cover the full manufacturing journey, and workers or supervisors only need to know the information relevant to what they’re doing.

 

Large size e-paper displays can be used as in-vehicle displays on a production line

 

Low-powered batteryless displays

An in-vehicle (or on-vehicle) display with some kind of wireless communication and location-awareness is the ideal solution. At the start of the production line, the display unit could be wirelessly loaded up with all the information about a particular vehicle and mounted on or in the bodyshell. As the car moves through the factory, the unit’s location sensors would then trigger the information on the display to update, so that it’s always showing the right details at the right time.

Such a display unit cannot be plugged into a mains power source and therefore needs to be battery-powered. And this is where the challenge comes in: traditional flat-panel thin-film transistor (TFT) liquid-crystal displays (LCDs), such as those found in laptops and tablets, are very power-hungry. And while charging their computer batteries daily may be a price consumers are willing to pay, it wouldn’t be feasible on a busy production line with hundreds or even thousands of these displays in use.

E-paper: the low-power display

The answer is to use a different type of display. E-paper, for example, made famous by e-book readers, is an ideal screen technology for this scenario. Firstly, it’s easy to read at wide angles, even in very bright or harsh lighting conditions. Secondly, it requires much less energy than a TFT LCD. This is because it doesn’t need a backlight, and only draws on its power source when you want to change the display’s contents. Once there, information will remain on the screen, using no further energy.

By contrast, to maintain a constant visible image on a TFT LCD, you need to refresh the display around 50 times per second, and continually shine a backlight through it. Both are big users of energy.

So where a battery-powered unit with an always-on TFT LCD would struggle to last a day between charges, an e-paper variant could last months. This makes it a realistic and attractive option for use in automotive manufacturing.

The next evolution of the production line

Pairing a large e-paper display with location sensors and Bluetooth Low Energy (or another low-power wireless technology) enables us to create an ideal in-vehicle display for use on production lines. Such a display will make it easier for operators and supervisors to do their jobs, support quality assurance and enable even better-centralised control of the production line.

Blogger: HD Lee, CTO, Pervasive Displays