Dot pitch

From Wikipedia, the free encyclopedia
  (Redirected from Pixel pitch)
Jump to: navigation, search
Color displays express pixel pitch as a measure of the size of a triad plus the distance between the triads.
Some other types of pixel layout showing how pixel pitch is measured.
For other uses, see Pitch.

Dot pitch (sometimes called line pitch, stripe pitch, or phosphor 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) on a display screen. In the case of an RGB color display, the derived unit of pixel pitch is a measure of the size of a triad plus the distance between triads.

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

  • undocumented or inadequately documented measurement method, complicated by ignorance of the existence of different methods
  • confusion of pixels and subpixels
  • element spacing varying across screen area (e.g., widening in corners compared to center)
  • differing pixel geometries
  • differing image and pixel aspect ratios
  • miscellanea such as Kell factor or interlaced video

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. 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.[citation needed]

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 does 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 pixel pitches in direct view monitors[edit]

LCD screens
Display resolution
(px×px)
Name Pixel count
(Mpx)
Aspect ratio Screen size
(in)
Pixel pitch
(µm)
Resolution
(px/in)
960×640 DVGA 0.61 3:2 3.5 77 326.0
1024×600 WSVGA 0.61 128:75 10.1 216 117.5
1024×768 XGA 0.78 4:3 9.7 192 132.0
1024×768 XGA 0.78 4:3 15.0 297 85.5
1024×768 XGA 0.78 4:3 17.0 337 75.3
1280×720 720p 0.92 16:9 13.3 230 110.4
1280×768 WXGA 0.98 5:3 15.4 262 96.9
1280×800 WXGA 1.02 16:10 12.1 204 124.7
1280×800 WXGA 1.02 16:10 13.3 224 113.5
1280×800 WXGA 1.02 16:10 14.1 237 107.1
1280×800 WXGA 1.02 16:10 15.4 259 98.0
1280×800 WXGA 1.02 16:10 17.0 286 88.8
1280×1024 SXGA 1.31 5:4 17.0 264 96.2
1280×1024 SXGA 1.31 5:4 18.1 280 90.7
1280×1024 SXGA 1.31 5:4 19.0 294 86.3
1366×768 WXGA 1.05 16:9 11.6 188 135.1
1366×768 WXGA 1.05 16:9 13.3 215 118.1
1366×768 WXGA 1.05 16:9 14.0 227 111.9
1366×768 WXGA 1.05 16:9 15.6 253 100.5
1366×768 WXGA 1.05 16:9 18.5 300 84.7
1360×768 WXGA 1.05 16:9 19.0 308 82.5
1440×900 WXGA+ 1.29 16:10 13.3 198 127.7
1440×900 WXGA+ 1.29 16:10 14.1 211 120.4
1440×900 WXGA+ 1.29 16:10 15.4 230 110.4
1440×900 WXGA+ 1.29 16:10 17.0 254 100.0
1440×900 WXGA+ 1.29 16:10 19.0 285 89.1
1400×1050 SXGA+ 1.51 4:3 15.0 214 118.6
1400×1050 SXGA+ 1.51 4:3 20.1 292 87.0
1600×900 1.44 16:9 13.1 181 140.1
1600×900 1.44 16:9 14.0 194 131.1
1600×900 1.44 16:9 15.4 213 119.2
1600×900 1.44 16:9 17.3 239 106.1
1600×900 1.44 16:9 20.0 277 91.8
1600×1000 1.60 16:10 22.0 296 85.8
1680×1050 WSXGA+ 1.76 16:10 15.4 197 128.9
1680×1050 WSXGA+ 1.76 16:10 17.0 218 116.5
1680×1050 WSXGA+ 1.76 16:10 19.0 244 104.0
1680×1050 WSXGA+ 1.76 16:10 20.1 258 98.4
1680×1050 WSXGA+ 1.76 16:10 21.0 269 94.4
1680×1050 WSXGA+ 1.76 16:10 22.0 282 90.0
1600×1200 UXGA 1.92 4:3 15.0 191 132.9
1600×1200 UXGA 1.92 4:3 20.1 255 99.6
1600×1200 UXGA 1.92 4:3 21.3 270 94.0
1920×1080 1080p 2.1 16:9 13.1 151 168.2
1920×1080 1080p 2.1 16:9 15.6 180 141.2
1920×1080 1080p 2.1 16:9 16.4 189 134.3
1920×1080 1080p 2.1 16:9 21.5 248 102.5
1920×1080 1080p 2.1 16:9 23.0 265 95.8
1920×1080 1080p 2.1 16:9 23.6 272 93.3
1920×1080 1080p 2.1 16:9 24.0 277 91.8
1920×1080 1080p 2.1 16:9 24.6 284 89.6
1920×1080 1080p 2.1 16:9 27.0 311 81.6
1920×1200 WUXGA 2.30 16:10 15.4 173 146.8
1920×1200 WUXGA 2.30 16:10 17.0 191 132.9
1920×1200 WUXGA 2.30 16:10 22.0 247 102.9
1920×1200 WUXGA 2.30 16:10 23.0 258 98.4
1920×1200 WUXGA 2.30 16:10 24.0 270 94.0
1920×1200 WUXGA 2.30 16:10 25.5 287 88.5
1920×1200 WUXGA 2.30 16:10 27.0 303 83.8
2048×1152 2.36 16:9 23.0 249 102.2
2560×1440 WQHD 3.68 16:9 27.0 233 108.8
2560×1600 WQXGA 4.09 16:10 30.0 250 101.6
3840×2400 WQUXGA 9.21 16:10 22.2 125 203.2
3840×2400 WQUXGA 9.21 16:10 39 220 115.7
3840×2400 WQUXGA 9.21 16:10 50 282 90.22
3840×2400 WQUXGA 9.21 16:10 65 365 69.40

Less common display pixel pitches[edit]

The best dot pitches of specialized video devices, such as the extremely tiny embedded components used inside an electronic viewfinder, head-mounted display, or especially a video projector, are much finer than that of a typical direct view display. For instance, an FLD can be as low as 10µm, LCD projector panels commonly reach 7µm or less, DLP 5.4µm, and LCoS 3.7µm.

See also[edit]

External links[edit]

  • 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.