Dot pitch

This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (March 2007)

Color displays express dot pitch as a measure of the size of a triad plus the distance between the triads.

Some other types of pixel layout showing how dot pitch is measured.

Dot pitch (sometimes called line pitch, stripe pitch, phosphor pitch, or pixel pitch) is a specification for a computer display, computer printer, image scanner or other pixel-based device that describes the distance, for example, between dots (sub-pixels) of the same color on the inside of a display screen. In the case of a color display dot pitch is a measure of the size of a triad plus the distance between the triads.

Dot pitch may be measured in linear units, usually millimeters, with a smaller number meaning closer spacing, or in dots per linear unit, for example dots per inch, with a larger number meaning closer spacing. Closer spacing generally produces a sharper image (as there are more pixels in a given area). However, other factors may affect image quality, including:

• measurement method not documented, complicated by general ignorance of the existence of multiple methods
• pixel spacing varying across screen area (e.g., increasing in corners compared to center)
• 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 in displays has been measured on the diagonal, as this gives the most accurate representation of image quality. Starting about the mid-1990s, however, some companies introduced a horizontal dot pitch as a marketing ploy^{[citation needed]}. 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.

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 in monitors

_{Bolded screen sizes indicate primarily laptop use.}

Less common dot pitches

The dot pitch of FLC displays (Ferro Liquid Crystal) can be as low as 0.012 mm.

See also

• Pixel

External links

• Dot Pitch Calculator
• PPI calculator, also shows dot pitch
• Megapixel Calculator, also identifies aspect ratio (e.g. 4:3, 16:9), and displays photo and video storage requirements for different formats at a given megapixel number.