Resolution - Display Devices

On a display device, the resolution means the maximum number of points that can be displayed simultaneously without an overlap in a row and number of such rows covering per square centimetre (or per square inch). In order to understand what non-overlap area is, refer to Fig.

The outmost ring is having almost negligible intensity, the second outer circle specifies the diameter which becomes visible to human eyes making a non- overlapping range of spots. The innermost spot is showing maximum intensity. So the non-overlapping points are actually those points which can be clearly distinguished. As given in the book, two adjacent spots are distinct if the difference between them is greater than the diameter at which each spot has intensity of about 60% of the maximum intensity.

Number of points is put in matrix form as the number of points in each horizontal line and the total number of horizontal lines that can be displayed at a time. In a layman's term if a CRT monitor can display 1024 points in a horizontal line and total horizontal lines that can be displayed simultaneously are 768, then the resolution of the monitor is 768 1024× . Each single point of display, which forms one unit of display, is called a pixel (short form of picture-cell). So a graphics display devices is treated as a graph paper with pixel as the smallest unit of display. Larger the resolution smaller is the size of the pixel.