pel spacing; pixel pitch
Technical term in computing and display technology referring to the distance between adjacent pixels.
The pixel pitch of this display is very narrow.
画素 means 'pixel', while 画素間隔 specifically refers to the spacing between pixels.
ピクセルピッチ is a common loanword synonym for 画素間隔, often used in technical specifications.
Compound of 画素 (がそ, 'pixel') and 間隔 (かんかく, 'interval, spacing').