One of the most common misconceptions about display customization among engineers and procurement team members is custom displays cost more. But the opposite is most often true.
A lower system-level cost can often be achieved with a custom display because off-the-shelf displays typically include components unnecessary for the specific application. With a standard off-the-shelf display, you just get what's available. A standard display may also be larger than required. Combine that with sub-optimal display integration into the end product, and its fairly easy to understand where costs mount up. Some of the best examples of standard display integration problems creating added cost are incompatible mounting features, the locations and types of connectors and cable lengths. These and other factors will cause increased bill-of-materials (BOM) costs as well as increased assembly costs.
Additionally, custom designs can incorporate supplementary components on the display such as LEDs, buttons, or ICs, to name a few. This eliminates intermediate printed circuit boards (PCBs), as well as streamlining system assembly, resulting in reduced overall assembly costs when taking a customized approach. Most of the time, the small up-front investment in customization results in lower BOM, lower assembly costs and due to optimal component integration, a more reliable system.
Lastly, a custom or semi-custom approach offers an end product focused solution. Standard products may already be very close to what's required. Whenever starting to develop a display for a new custom application, always look at standard components first. But more often is it beneficial to the usability of the end product to have the optimal display designed in, rather than settling for the predetermined attributes of a standard product. And in allotting product configurations, the requirements are unique such that a standard product would never fully support the end application.
Let's look at some of the most often-desired customization options.
With a custom approach a larger more expensive glass size isn't being used. Neither is implementing a smaller glass size which underutilizes the real-estate potential being considered. There are two options to consider -- start with the customer's maximum viewing area available, and then design the most efficient glass size to support that viewing area. However, the reverse process also works, where the application has a maximum mechanical envelope and the glass size decision is in favor of the largest active area (AA) or viewing area (VA) possible. Aside from the fixed cost of the LCD driver IC (integrated circuit), the module cost is generally proportional to the glass size. For TFT (thin-film transistor) it’s more economical to stay with one of the standard glass sizes available. For monochrome the tooling and minimum order quantity is low enough to support creating the optimal configuration for each application.
Photo courtesy: Phoenix Display
Decisions about this option should start with the display content required in the end product, and then specify the optimal resolution. For TFT it's more economical to stay with one of the standard glass resolutions available. For monochrome applications, the tooling and minimum order quantity (MOQ) is low enough to support creating the optimal configuration for each application. But more isn't necessarily better. Human vision is the gating factor. High resolution for small displays become unreadable at a distance or for the vision-impaired. Also as you go below 0.200 pitch on a monochrome display reduced contrast occurs.