Renesas Displays
October 24, 2012, Renesas DevCon, Anaheim, CA—We talked with Cathy Dotson, Dale Maunu, Dean Collins, and Yuji Kondo from NLT Displays about their various display products. The displays are from the former NEC LCD Technologies company and geared for industrial use.
The context for the display group is that they are not in the consumer-grade business, and the industrial, medical, and other display applications they address are not trying to do a lot of CG animation viewing. At this time, they are not doing automotive displays, because the use modes and volumes are not a good fit with their manufacturing capacities. They offer a number of display sizes, with up to 24-inch diagonal measurements. Last year, they introduced a 9-inch HD display that serves as a portable reference monitor.
They also introduced a lenticular autostereoscopic display with some interesting features. The lenses are vertically oriented, and not diagonal like other lenticular displays. The RGB stripes are horizontal. In addition, they doubled the dot resolution in the horizontal direction to provide twice as many sub-pixels in the horizontal direction. This arrangement allows them to display full resolution HD in a side-by-side format, rather than the normal half resolution from other layouts. The resulting display has less than 2 percent crosstalk.
Their displays are built for a long lifetime operation. This strategy was developed 15 years ago to focus on markets that needed over 5 years lifetime for a display. To date, most of the displays are showing over 10-years operating lifetimes. The support model for these types of products requires them to offer 18-month end-of-life notifications for most users, and an additional 6 months for their advanced customers.
In general, the replacement products are built on the same footprint, and there is a fair amount of overlap across the various family lines. The sizes and resolutions available, and the alternative resolutions allow for easier transitions for the display technologies over time. Other industrial and infrastructure products like optical fiber follow this same trend.
The quality in the displays is evidenced by the very low color shift over time and temperature for the displays. This low shift is a function of the design and the quality of the materials, as no shortcuts or less dependable materials are used. The long-term reliability and quality provide the capabilities needed in medical and broadcast applications. The displays are designed with feedback to the drivers for the RGB pixels to maintain intensity and color balance. The displays are derated from maximum brightness to enable longer lifetimes and less color drift. They characterize the display colors over temperature, and use in-plane switching to improve the off-angle color shift issues.
For touch-enabled displays, they offer many technologies for the sensors. They have an outside source for the resistive sensors, and have developed a complete solution for capacitive sensors. This capacitive technology works with optically bonded and with separate cover glass displays. Soon, they will have on-cell capacitors to reduce manufacturing complexity and cost. One reason for their high performance is the good signal: noise ratios in the touch sensors. They get over 6:1 signal: noise, with allows for medical applications to pass sensitivity and functional tests with 3 gloves on a hand.
The displays are outputting a standard 24-bit image. They have built some 10-bit/color displays on a high resolution platform and achieved a 72 percent NTSC color gamut. More of the product lines are moving towards a LVDS (low-voltage, differential signaling) interface to improve performance, power efficiency, and reduce signaling noise.
The areas of interest in these industrial-grade displays include casino gaming machines, safety and security functions and monitors, and medical displays. Small-scale signage is another area that can use the industrial displays. These categories have an average 9-12 month ramp up. Medical, military and aerospace products take longer. This long lead time changes in their customers’ design starts, and also allows for greater customization in the displays. It’s important to take all factors and dynamics into account in creating solutions.
