Multi-line addressing (MLA) for passive-matrix (PM) OLED displays
8 June 2009 - 10 June 2009
Austria
Part of the CARO project partners, namely Optrex Europe GmbH, Fraunhofer IPMS, Chair of Microelectronics (Saarland University), and Novaled AG, recently developed a 160 x 80 pixel PM OLED display, based on a high temperature stable and long-living Novaled PIN OLED? layer stack and driven by a new and worldwide unique OLED driver. The main feature of this PM OLED driver is the implemented innovative MLA scheme, called SELA (Summed Equiline Addressing). Today’s standard PM OLED displays will be driven by a single-line addressing scheme. Instead of that the SELA mode realized within the CARO research association allows the parallel driving of multiple rows, and consequently can effectively prevent high current amplitudes occurring in standard single-line addressing.
The reduction of the driving current amplitude results in an extension of the operating lifetime of the displays. Depending on the visual content, on the number of parallel driven rows (2-4), as well as on the overall display rows, an improvement of the operating lifetime up to one order of magnitude is expected. Moreover the power consumption will be reduced. Alternatively the SELA scheme enables higher display brightnesses or at the same brightness the realization of PM OLED displays with a higher resolution. By that saving of energy the SELA scheme also contributes to the realization of a “green” OLED display system integration.
The OLED MLA driver (“OC3.1”) developed by the Fraunhofer IPMS was designed for highly reliable applications, requested e.g. from the automotive industry. The driver is specified for operations between -40°C and +125°C, exhibits an OLED drive voltage up to 25 V, and a column source current up to 2 mA. In particular the latter can currently not be fulfilled by any commercial available PM OLED driver. The various underlying SELA algorithms were developed at the Chair of Microelectronics at the Saarland University.
In addition to the innovative addressing concept and the new OLED MLA driver, a high temperature stable and long-living orange emitting PIN OLED layer stack was developed by Novaled AG. In automotive applications high reliability at 85°C operational temperature and highly stable brightness (often only 20% reduction over lifetime is allowed) is required. The newly developed OLED stack offers an operating lifetime of currently 5.300 hours at 85°C and 20% brightness drop at an initial brightness of 600 cd/m².
The CARO partner Optrex Europe GmbH was responsible for the layout of the display and in particular for the subsequent manufacturing of the textured 160 x 80 pixel dot-matrix substrate. At the Fraunhofer IPMS the deposition and encapsulation processes were performed as well as the module assembly.
The technology demonstrator will also be presented during the upcoming SID Display Week 2009 in San Antonio, Texas, USA, on the German pavilion, booth no. 101-4. In autumn 2009 the first presentation in the Far East is planned during the IMID 2009 in Seoul, South Korea.
The reduction of the driving current amplitude results in an extension of the operating lifetime of the displays. Depending on the visual content, on the number of parallel driven rows (2-4), as well as on the overall display rows, an improvement of the operating lifetime up to one order of magnitude is expected. Moreover the power consumption will be reduced. Alternatively the SELA scheme enables higher display brightnesses or at the same brightness the realization of PM OLED displays with a higher resolution. By that saving of energy the SELA scheme also contributes to the realization of a “green” OLED display system integration.
The OLED MLA driver (“OC3.1”) developed by the Fraunhofer IPMS was designed for highly reliable applications, requested e.g. from the automotive industry. The driver is specified for operations between -40°C and +125°C, exhibits an OLED drive voltage up to 25 V, and a column source current up to 2 mA. In particular the latter can currently not be fulfilled by any commercial available PM OLED driver. The various underlying SELA algorithms were developed at the Chair of Microelectronics at the Saarland University.
In addition to the innovative addressing concept and the new OLED MLA driver, a high temperature stable and long-living orange emitting PIN OLED layer stack was developed by Novaled AG. In automotive applications high reliability at 85°C operational temperature and highly stable brightness (often only 20% reduction over lifetime is allowed) is required. The newly developed OLED stack offers an operating lifetime of currently 5.300 hours at 85°C and 20% brightness drop at an initial brightness of 600 cd/m².
The CARO partner Optrex Europe GmbH was responsible for the layout of the display and in particular for the subsequent manufacturing of the textured 160 x 80 pixel dot-matrix substrate. At the Fraunhofer IPMS the deposition and encapsulation processes were performed as well as the module assembly.
The technology demonstrator will also be presented during the upcoming SID Display Week 2009 in San Antonio, Texas, USA, on the German pavilion, booth no. 101-4. In autumn 2009 the first presentation in the Far East is planned during the IMID 2009 in Seoul, South Korea.