Using fast or partial updates with e-paper displays can greatly improve the user experience. These updates reduce the time required to update a display, opening up new application areas to designers. In particular, for applications where only a small part of the display needs to change regularly, implementing partial updates can be very beneficial.

Both global updates (also referred to as full update or global refresh) and fast/partial updates (or local update or fast refresh) are supported by Pervasive Displays. A global update will impact every pixel on the display, while a fast/partial update only impacts the pixels that need to change, in order to display the new image. With a fast update, the full image is sent to the driver IC, which carries out the image data comparison. A partial update requires an area (window) to be defined and the system side sends just the image data specific to that area, but uses the same driving waveform to carry out the update.

The benefits of fast and partial update modes

As with any display technology, the faster e-paper can be updated, the better. Developers can use fast and partial update modes in place of a global update to improve the user experience when a display is updated ‘live’ in front of the user.

Both fast and partial update modes enhance flexibility for developers to choose a method best suited to their application. Additionally, the ability to execute a fast or partial update increases the number of possible applications.

Applications:

  • IoT or industrial devices
  • Human machine interfaces (HMIs)
  • Infotainment system, smart appliances, digital signage
  • Heating, ventilation, and air conditioning (HVAC)
  • Spotlight items, alerting devices, shelf talkers

Fast and Partial update example

Update comparison of fast and partial update

Update type
Global Update
Fast Update
Partial Update
InitializationPanel initializationPanel initializationPanel initialization
Image data uploadFull screen image
New image buffer with all 0x00 buffer
Full screen image
Previous image buffer and new image buffer
Partial window image
Previous image buffer and new image buffer
Panel updateWhole screen
Flashing effect
Whole screen
Fast mode
Partial window
Fast mode
Image qualityOptimal qualityPossible ghostingPossible ghosting
Upload image speedSlowSlowFast
Update image speedSlowFastFast
Overall speedSlowFasterFastest

Find out more about

As fast update and partial update modes may not be suitable for every application, it is important to understand how they are implemented and assess the potential consequences of implementing them.

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APAC

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