Orthogonality A deviation from true perpendicular of the vertical. Parallelogram A deviation of the sides from the true vertical. Persistence Phosphor characteristic consisting of the ability to emit light after excitation current of electron beam is removed. Phosphor Chemical compound that emits light while being excited by electrons. An inward bowing of the video image.
All monitors experience slight amount of pincushion distortion.
The manufacturer has a guideline on what the specification is for each model. The pincushion changes per resolution and also according to the size of the image. Pincushion is similar to bowing or barrel distortion. The ability of the electron beam to hit precisely the correct phosphor color dot. If a full page of red color is shown on the display, impurity would result in a purple or greenish color region.