As 32" 720P LCD TVs move under $500 and 17" PC monitors head below $100, TV, PC, monitor and panel makers must find ways to both differentiate and add value. Avoiding "commodity" status is connected to both increasing demands on video/graphics processors, and handling greater bandwidth requirements for interconnects that transport burgeoning amounts of data. Here are seven ways to differentiate next-generation panels:

1. Address size, resolution, wide color gamut and deep color requirements
2. Optimize cost
3. Control electromagnetic interference (EMI)
4. Enable lower power operation
5. Increase frame rate
6. Deliver wireless high definition
7. Provide a full digital experience

Size, resolution and color
Larger size, high resolution, wide color gamut, and deep color all require higher bandwidth in both the internal and external bus. Consider the external bus cable medium between the DVD and TV. Increased bandwidth can be observed at the high definition media interface (HDMI). An older HDMI 1.1 standard supported only 8 bits per color (pbc) while requiring approximately 1.65 Gbps of link speed. In comparison, today's HDMI 1.3 standard needs 2.25 Gbps link speed in order to support 10 bpc.

The increased demand for bandwidth also affects the internal bus such as the link from the TV system controller board to an LCD panel controller board. The traditional LVDS technology link is becoming a bottleneck for the huge amount of data delivered by the external bus. In this case, two sets of four pair LVDS are necessary to support Full HD resolution (1080p).

In response, a new display standard, DisplayPort based on SerDes technology is making inroads to addressing the bandwidth pressures posed by new requirements. One 8-wire DisplayPort implementation replaces a 32 x 4 LVDS link in terms of bandwidth. Featuring 10.8 Gbps of bandwidth over four links, DisplayPort is adequate to satisfy high resolution and deep color performance challenges. In PC applications its benefits are more obvious--it has the ability to optimize the display by driving resolution size of the panel from the GPU.

In TV applications, the external connection to the set top box is HDMI and the internal bus connection is DisplayPort. Both mediums can coexist and complement each other in this environment.

Optimizing cost
Integration is the key to cost optimization. The processor today integrates such I/O functions as HDMI, ADC for external analog components, LVDS interfaces, post image processing, and the tuner. New interface standards including DisplayPort enable direct drive for monitors eliminating the scalar processor and control board. The native resolution of the panel is enhanced, decreasing overall system cost and increasing performance by simply removing unnecessary steps in image compression and manipulation.

Control EMI
As resolution size and color depth increase, the system requires greater speed from its system clock and pixel clock. The drawback of increasing the frequency, however, is that it results in greater electromagnetic interference (EMI). There are strict requirements for EMI and given increased bandwidth, even greater EMI control is necessary.

New standards solve this problem as part of the specification, yet the challenge is at the system level. Mature phase locked loop technology with best-in-class spread spectrum generation and degeneration are necessary to reduce EMI and keep it under control.

Next: Manage power, Increase frame rate

Manage power
Higher speed, bandwidth and resolution all translate into a dramatic increase in power. This fact, coupled with the move towards thinner panels means that there is no fan on the panel. As fans are removed from the environment completely, lower power technology in circuit implementation and process geometry become even more critical. New standards such as DisplayPort enable more data per link, therefore decrease the I/O power, but they require complex PLL technologies that might re-increase the power. Advanced low power PLL design with newer process technologies will help to lower the overall power of the application.

Increased frame rate
Increasing the frame rate from 60Hz to such higher rates as 120Hz improves image processing and video quality. This must take place on a TV panel just before the image reaches the screen, and it is not an easy task. The frames must be interpolated to make up new ones and no standard means currently exists to accomplish it. The 120 Hz rate frames shown in Figure 1 below show a motion interpolation. In comparison, Figure 2 indicates the benefits of implementation at 60Hz. Notice the added sharpness and overall reduction in blur in the image on the right.

Figure 1: Motion interpolation

Figure 2: 60Hz Vs 120 Hz [2]

Wireless HD
Wireless typically provides greater convenience for the end user. When a wireless connection exists between the set-top-box and TV panel, the user is not required to purchase expensive cables or hide them inside the wall for a wall-mounted panel. When a wireless connection exists between a laptop and a large-screen TV, it is easy to share the laptop screen with others.

A trade off exists, however, between quality and convenience. When the quality is "good enough" wireless connections will become more popular. Wireless HDMI implementations are now coming to the fore. The move towards wireless interfaces is inevitable and those who develop innovation and expertise in providing it will be well positioned to enjoy a leading position.

Full digital experience
Full high definition does not just belong to video. It belongs to audio as well. This translates into greater integration of audio and video. Therefore, provision in the interface and on the panel for audio processing is necessary. New interfaces such as DisplayPort and HDMI integrate audio enabling a richer digital experience.

Conclusion
Digital display is evolving with greater demands from users. At the same time, the market is segmenting into low, medium, and high-end applications. Each segment requires a unique focus on features and associated technology that can provide viable solutions. Vendors must watch for changes in requirements very carefully and adapt quickly to avoid falling behind. Evolving features enable display panels to remain out of the "commodity" category as long as the features coincide with current user demands and anticipate the demands of the future.

About the authors
Ji Park is the vice president and general manager of the IDT Digital Display Operation. He holds his MBA degree from University of Dallas and a BSEE from University of Texas at Austin. . He can be reached at Bertan.tezcan@idt.com.

Bertan Tezcan is a product marketing manager in the IDT Digital Display Operation. Bertan holds an MBA from Santa Clara university, and is working towards his PhD in EE from University of Southern California. . He can be reached at Ji.park@idt.com.