Pincushion distortion is commonly found in which type of display device?

• A. LED monitors
• B. LCD panels
• C. Cathode ray tubes (CRT)
• D. Plasma displays

Answer: (C)

Pincushion distortion is a geometric distortion that commonly occurs in cathode ray tubes (CRT). This type of distortion is characterized by the image appearing to bulge inward towards the center, resembling a pincushion. CRTs use an electron gun that emits beams onto a phosphorescent screen, and variations in the magnetic or electric fields can cause the electron beams to deviate from a straight path, leading to this specific type of distortion.

In contrast, modern display technologies like LED monitors, LCD panels, and plasma displays utilize entirely different mechanisms to produce images, such as liquid crystal modulation or plasma discharge, which do not exhibit pincushion distortion in the same manner. These technologies are designed to minimize various forms of distortion and provide a more consistent image quality across the display surface. Hence, the unique characteristics of CRTs make them the primary display device associated with pincushion distortion.