Dot pitch

Dot pitch (sometimes called line pitch, phosphor pitch or pixel pitch) is a specification for a computer display that describes the distance between phosphor dots (sub-pixels) or LCD cells of the same color on the inside of a display screen. Thus, dot pitch is a measure of the size of a triad plus the distance between the triads.

Measured in millimetres, a smaller number generally means a sharper image (as there are more dots in a given area), and vice versa. Note, however, that a monitor with a smaller dot pitch usually has a better-quality image, but by no means always, due to a number of factors, including:

• measurement method not documented, complicated by general ignorance of the existence of multiple methods
• differing pixel geometries
• differing screen resolutions when attempting to judge picture quality
• tightness of electron beam focus and aim (in CRTs)
• differing aspect ratios

Traditionally, dot pitch was always measured on the diagonal, as this gives the most accurate representation of the monitor. Starting about the mid-1990s, however, some companies introduced a horizontal dot pitch as a marketing ploy. By measuring only the horizontal component of the dot pitch and ignoring the vertical component, even a cheap, low-quality monitor could be awarded a small-seeming dot pitch.

The exact difference between horizontal and diagonal dot pitch varies with the design of the monitor (see Pixel geometry and Widescreen), but a typical entry-level 0.28 mm (diagonal) monitor has a horizontal pitch of 0.24 or 0.25 mm, a good quality 0.26 mm (diagonal) unit has a horizontal pitch of 0.22 mm. 0.099mm is the smallest dot pitch at the current time, this will ultimately produce an incredibly sharp picture on the screen.

The above dot pitch measurement do not apply to aperture grille displays. Such monitors use continuous vertical phosphors band on the screen, so the vertical distance between scan lines is limited only by video input signal's vertical resolution and the thickness of electron beam, so there is no vertical 'dot pitch' on such devices. Aperture grille only has horizontal 'dot pitch', or otherwise known as 'stripe pitch'.

Common dot pitches

_{Bolded screen sizes indicate primarily laptop use.}

See also

• Pixel

External links

• Dot Pitch Calculator