Viewing angle: Difference between revisions

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{{Short description|Term in display technology}}

{{About|a display technology concept|the similarly named concept in photography|angle of view}}

{{More citations needed|date=July 2023}}

In [[display device|display technology]] parlance, '''viewing angle''' is the maximum [[angle]] at which a display can be viewed with an acceptable visual performance. In a technical context, thisthe angular range is called '''[[viewing cone]]''' defined by a multitude of '''[[viewing cone|viewing directions]]. The viewing angle can be an angular range over which the display view is acceptable,<ref>{{cite web |url=https://support.elotouch.com/TechnicalSupport/Video/viewing_angle/ |title=EloTouch Solutions {{!}} Support |website=support.elotouch.com |access-date=2019-11-21}}</ref> or it can be the angle of generally acceptable viewing, such as a twelve o'''clock viewing angle for a display optimized or viewing from the top.<ref>{{cite web |url=https://focuslcds.com/journals/lcd-viewing-angles-explained/ |title=LCD Viewing Angles Explained |website=Focus LCDs |date=10 December 2018 }}</ref>

The image may seem garbled, poorly saturated, of poor [[contrast ratio|contrast]], blurry, or too faint outside the stated viewing angle range, the exact mode of "failure" depends on the display type in question. For example, some [[projection screen]]s reflect more light perpendicular to the screen and less light to the sides, making the screen appear much darker (and sometimes colors distorted) if the viewer is not in front of the screen. Many manufacturers of projection screens thus define the viewing angle as the angle at which the [[luminance]] of the [[image]] is exactly half of the maximum. With LCD screens, some manufacturers have opted to measure the contrast ratio, and report the viewing angle as the angle where the contrast ratio exceeds 5:1 or 10:1, giving minimally acceptable viewing conditions.

The viewing angle is measured from one direction to the opposite, giving a maximum of 180° for a flat, one-sided screen. SomeA display devicesmay exhibit different behaviourbehavior in horizontal and vertical axisaxes, requiring users and manufacturers to specify maximum usable viewing angles in both directions. Usually, the screens are aligned and useddesigned to facilitate greater viewing angleangles inat the horizontal level, and smaller angleangles inat the vertical level, should the two of them be differentdiffer in magnitude.

The viewing angle for some displays is specified in only a general direction, such as 6 o'clock or 12 o'clock.

Early [[LCD]]s had strikingly narrow [[viewing cone]]s, a situation that has been improved with current technology.

Narrow [[viewing cone]]s of some types of displays have also been used to bring a measure of [[security]] in businesses, where employees handle [[privacy|private information]] in the presence of customers, banks being one example. Rectangular filters[[monitor filter|privacy filter]]s fitting to the computer monitors have also been sold as accessories for this purpose.

==LEDs==

LEDs are measured so that the line along half the viewing- angle from directly forward is half the brightness as at directly forward.

== References ==

{{Reflist}}

*{{cite web|url=http://www.elotouch.com/Support/TechnicalSupport/viewing_angle.asp|title=Elo Touch Solutions &mdash; Viewing angle|publisher=elotouch.com|accessdate=2014-01-25}}

*{{cite web|url=http://www.grandwell.com/viewing_angle_brightness.php|title=Indoor & Outdoor LED Signs � Digital Signage � LED Displays � Electronic Signs &#124; Grandwell|publisher=grandwell.com|accessdate=2014-01-25}}

[[Category:Display technology]]