Top five requirements to consider for automotive surface-integrated displays
October 21, 2019
The surface area devoted to displays in vehicle interiors is growing rapidly driven by increased vehicle automation and connectivity. In order to sustain this trend, displays and touch screens have to become much better integrated into the curved and shaped surfaces of the interior. At the same time, these new surface-integrated displays must meet strict automotive requirements some of which we discuss below.
Conformable and shapeable
Auto makers are looking for innovative display technologies that merge with the car interior design while offering passengers a more secure and personalised environment. There is a demand for displays that can be shaped and conformed to the non-flat surfaces of the car interior. Be it an S-shaped centre console, a round display on the steering wheel or a curved digital side-view mirror, these screens should follow the design and not dictate the design.
Display brightness is a key consideration when choosing new display technologies for cars. High-brightness displays ensure that the information displayed can be viewed in daytime and sunlit conditions. Therefore any new display technology needs to meet or exceed the brightness of LCD screens used in vehicles today.
Automotive surface-integrated displays need to last as long as the lifetime of a vehicle which could be more than 10-15 years. This is much longer than the lifetime of many mainstream consumer electronic products such as, for example, smartphones and smartwatches.
Surface integrated displays face a unique environment and therefore require high level reliability. They have to be tested in much higher and much lower temperature and humidity conditions compared to consumer electronics.
Apart from meeting all other requirements, for any new technology to be adopted in automotive it has to be available at an affordable price. This requirement is even more important given the trend for bigger screens.
New display technologies for automotive
The dominant active-matrix display technology in vehicles is LCD made with amorphous silicon (a-Si) thin-film transistors (TFTs) on glass. However, glass can only be curved to an extremely limited extent and is difficult to cut to non-rectangular shapes. It is also relatively thick and heavy and can shatter, causing issues with head impact.
Some automotive companies are experimenting with flexible OLED which has been adopted in some high-end smartphones and smartwatches. However, this technology has several significant limitations for vehicle applications: lower reliability and lifetime compared to LCD; lower brightness; and much higher cost than LCD.
FlexEnable has developed a complementary flexible display technology, known as Organic LCD (OLCD). OLCD addresses the above issues by using, as far as possible, the existing supply chain for automotive qualified LCD displays. This is done by replacing the a-Si TFTs on glass with organic TFTs made on plastic using a very low temperature process.
By making a plastic version of LCD that can be made on existing active-matrix LCD production lines, FlexEnable reduces the cost, risk and time of making the transition to conformable and shapeable displays for vehicles. Unlike flexible OLED, the displays can be very bright with no impact on lifetime as this is primarily a function of the backlight implementation.
OLCD can also address the demand for higher contrast automotive displays in the future as it allows for a ‘dual-cell’ approach to be implemented providing advantages in black level (contrast), cost, and module thickness, while retaining the conformability and shapeability required for automotive applications.
Moreover, OLCD also enables ultra-narrow bezel displays. This is achieved by folding the borders of the display as FlexEnable has already demonstrated earlier this year.
An S-shaped centre unit consisting of twin 12.1” OLCDs. Source: Novares
A side-mirror replacement using curved OLCD. Source: Novares
Working closely with automotive clients FlexEnable is already developing display prototypes for cars. For more information on OLCD, please get in touch with us at firstname.lastname@example.org.