Development of Organic Light Emitting Diode (OLED) Driver for Automotive Components

The OLED self luminous display device features high brightness, high contrast, a wide field of vision with a rapid response and is compact as well as light-weight. At the present time the device is implemented in sub-main displays for mobile phones along with other mobile devices, such as portable audio systems, as well as small to medium size displays for automotive components, including car audio and instrument panels. A lot of activities are proceeding to create large size versions of these displays, with announcements being made regarding plans to adopt them for television products. The displays, therefore, are becoming a focal point of attention with a high potential for the future. OLED displays can be categorized into passive drive and active drive methods. The dot matrix structure and segment structure are passive drive method OLED panels. Passive drive method panels are comprised of an OLED element located at the cross point of the anode and cathode. The drive method adopted uses anodes and cathodes to drive elements to emit light. Active drive method OLED panels, on the other hand, are comprised of transistors allocated for driving OLED elements inside the panel. This structure is identical to the structure of generic TFT liquid crystal displays1). Passive drive method OLED panels were launched in the market before active drive method OLED panels as they are easier to manufacture and the manufacturing costs are lower in comparison with active drive method panels. OKI started mass producing drivers for passive drive method OLED displays in 2002 and the development of OLED drivers is ongoing for automotive components, the growth of which is expected to continue in the market well into the future. This paper describes activities carried out by OKI with regards to technology development for drivers and controllers for passive drive method OLED, which are required for automotive components, as well as activities intended to reduce electromagnetic interference (EMI), considered to present technical challenges of a high degree. Furthermore, a product summary of single chip OLED drivers include controllers, developed by OKI for OLED displays of passive drive method featuring a dot matrix structure, is also provided.