Pioneer PDP-503CMX Product Training Manual page 13

Deep Waffle Rib Structure: realises even higher light emission
efficiency
For the PDP-503, Pioneer's further improved this technology
by making each individual cell deeper.
Deep Waffle Rib Structure
(Deep Encased Cell Structure)
The new cell structure has a greater light emission area, so this results in
even higher light emission efficiency—50% higher than our previous model .
(PDP-502)
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