Tianma: free-form touch displays offering design freedom
With the introduction of electronics into a growing number of areas of daily life, the demand for innovative interaction possibilities between human and machine has also been growing. The touch display has largely established itself as an intuitive medium. But not every display has to be rectangular. At electronica 2018, display specialist Tianma is going to present new prototypes and process technologies with which developers and designers can now design displays in line with their individual ideas, following the classic design motto "form follows function".
To demonstrate the possibilities for producing such new and unconventionally shaped displays, Tianma presented a round display with a hole in the middle. Until now, it has been difficult to create comparable shapes because of the matrix-shaped arrangement of the pixel elements required. With individually embedded gate drivers as Virtual Gate Inline Pixel Array (VGIA), the desired degrees of design freedom are achieved when designing the display.
To meet customer demand for free-form displays, Tianma has solved several problems in the manufacturing process. These include the low cutting accuracy and the limited range of shapes that have hitherto precluded any free design options. Laser-assisted material processing offers the possibility of high-precision cuts in the 100 micrometer range. For example, very fine holes can be created by gentle laser ablation. This production technique enables classic and analog clock hands in combination with a background display. Applications include "smart" wristwatches and cockpit instruments in the automotive sector.
A prototype presented by Tianma illustrates the specific features of this technique. The display with a diameter of 12.7 cm provides an extremely slim concentric edge of 3 mm. This result is achieved by using a special oxide semiconductor material as active TFT backplane, which offers much higher electron mobility compared to conventional amorphous silicon. Smaller pixel structures, as well as more compact, transparent driver circuits, can be generated while maintaining the same level of current. The latter can be housed in the edge of the screen to save space or even arranged within the active display area.
Despite the capacitive touch sensor (PCAP), the display with a thickness of just 2.1 mm can be considered ultra slim. With a resolution of 1080 x 1080 pixels and a very high contrast ratio of 1,000,000:1, the display is capable of producing impressive graphics.