輝度

関: brightness、intensity

WordNet

high level or degree; the property of being intense (同)intensiveness
the amount of energy transmitted (as by acoustic or electromagnetic radiation); "he adjusted the intensity of the sound"; "they measured the stations signal strength" (同)strength, intensity level
the location of a visual perception along a continuum from black to white
intelligence as manifested in being quick and witty (同)cleverness, smartness
the luminous flux incident on a unit area (同)illumination
a measure of luminance

PrepTutorEJDIC

(感情・行動・熱・色などの)『強烈さ』,熱烈さ,強度
輝き;明るさ;(自の)あざやかさ

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/05/09 05:42:16」(JST)

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[Wiki en表示]

Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted or reflected from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m²). A non-SI term for the same unit is the "nit". The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m².

Explanation

Luminance is often used to characterize emission or reflection from flat, diffuse surfaces. The luminance indicates how much luminous power will be detected by an eye looking at the surface from a particular angle of view. Luminance is thus an indicator of how bright the surface will appear. In this case, the solid angle of interest is the solid angle subtended by the eye's pupil. Luminance is used in the video industry to characterize the brightness of displays. A typical computer display emits between 50 and 300 cd/m². The sun has luminance of about 1.6×10⁹ cd/m² at noon.^[1]

Luminance is invariant in geometric optics. This means that for an ideal optical system, the luminance at the output is the same as the input luminance. For real, passive, optical systems, the output luminance is at most equal to the input. As an example, if you form a demagnified image with a lens, the luminous power is concentrated into a smaller area, meaning that the illuminance is higher at the image. The light at the image plane, however, fills a larger solid angle so the luminance comes out to be the same assuming there is no loss at the lens. The image can never be "brighter" than the source.

Definition

Luminance is defined ^[2] by the derivative

where

is the luminance (cd/m²),

is the luminous flux or luminous power (lm),

is the angle between the surface normal and the specified direction,

is the area of the surface (m²), and

is the solid angle (sr).

The expression is written using Leibniz's notation.

Units

A variety of units have been used for luminance, besides the candela per square metre.

One candela per square metre is equal to:

10⁻⁴ stilbs (the CGS unit of luminance)
π apostilbs
π×10⁻⁴ lamberts
0.292 foot-lamberts

Health effects

Retinal damage can occur when the eye is exposed to high luminance. Damage can occur due to local heating of the retina. Photochemical effects can also cause damage, especially at short wavelengths.

References

^ "Luminance". Lighting Design Glossary. Retrieved Apr 13, 2009.
^ Chaves, Julio (2008). "Introduction to Nonimaging Optics". Optical Science and Engineering 134. CRC Press. p. 449. ISBN 9781420054293.

External links

A Kodak guide to Estimating Luminance and Illuminance using a camera's exposure meter. Also available in PDF form and Google Docs online version
Autodesk Design Academy Measuring Light Levels

UpToDate Contents

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English Journal

Towards Low-Cost Thermo-Optic Imaging Sensors: A Detection Principle Based on Tunable 1D Photonic Crystals.

Exner AT, Pavlichenko I, Lotsch BV, Scarpa G, Lugli P.AbstractInfrared (IR) sensors employing optical readout represent a promising class of devices for the development of thermographic imagers. We demonstrate an infrared radiation detection principle based on thermally tunable one-dimensional (1D) photonic crystals acting as optical filters, integrated with organic and inorganic light emitting diodes (OLEDs and LEDs, respectively). The optical filters are composed of periodically assembled mesoporous TiO2 and SiO2 layers. Due to the thermal tunability of the transmission spectrum of the optical filter, the intensity of light passing through the filter is modulated by temperature. The tuned spectrum lies in the visible region, and therefore can be directly detected by a visible-light photodetector. The thermal response of the luminance of the OLED-Photonic Crystal ensemble can be tuned by 3.8 cd m(-2) K(‑1). Furthermore, we demonstrate that the local temperature profile can be time and spatially resolved with a resolution of 530 by 530 pixel, thus enabling a potential application as an infrared imaging sensor featuring low power consumption and low fabrication costs.
ACS applied materials & interfaces.ACS Appl Mater Interfaces.2013 Jan 3. [Epub ahead of print]
Infrared (IR) sensors employing optical readout represent a promising class of devices for the development of thermographic imagers. We demonstrate an infrared radiation detection principle based on thermally tunable one-dimensional (1D) photonic crystals acting as optical filters, integrated with o
PMID 23286349

Loss of scotopic contrast sensitivity in the optomotor response of diabetic mice.

Umino Y, Solessio E.SourceDepartment of Ophthalmology, SUNY Upstate Medical University, Center for Vision Research and SUNY Eye Institute, Syracuse, NY, 13210, United States.
Investigative ophthalmology & visual science.Invest Ophthalmol Vis Sci.2013 Jan 3. pii: iovs.12-10825v1. doi: 10.1167/iovs.12-10825. [Epub ahead of print]
PURPOSE: Diabetes reduces retinal and visual sensitivity to dim light flashes. However, the impact of diabetes on contrast sensitivity in dim light is unknown. Based on the lowered visual sensitivity previously observed, we hypothesized that contrast sensitivity would similarly be reduced. We theref
PMID 23287790

Perceiving threat in the face of safety: excitation and inhibition of conditioned fear in human visual cortex.

Miskovic V, Keil A.SourceCenter for the Study of Emotion and Attention, University of Florida, Gainesville, Florida 32611.
The Journal of neuroscience : the official journal of the Society for Neuroscience.J Neurosci.2013 Jan 2;33(1):72-8. doi: 10.1523/JNEUROSCI.3692-12.2013.
Previous findings have established that cortical sensory systems exhibit experience-dependent biases toward stimuli consistently associated with threat. It remains unclear whether safety cues also facilitate perceptual engagement or how competition between learned threat and safety cues is resolved
PMID 23283323

Japanese Journal

3D CG Image Quality Metrics for the Contrast Enhancement of the Object Region Including S-CIELAB Color Space with 8 Viewpoints Parallax Barrier Method (イメージ・メディア・クオリティ)

KAWABATA Norifumi,MIYAO Masaru
電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 115(48), 17-22, 2015-05-22
NAID 40020491405

Optical outcoupling enhancement in organic light-emitting diodes using a gradually varying refractive index dielectric structure

Cho Hyun-Jun,Kim Doo-Hoon,Lee Ho-Nyeon
Jpn. J. Appl. Phys. 54(6), 062101, 2015-05-15
… In addition, the emission spectra remained almost unchanged following the introduction of the GRID MC structures, and the angular distribution of luminance became similar to that of Lambertian emission. …
NAID 150000110818

Optimization of hybrid blue organic light-emitting diodes based on singlet and triplet exciton diffusion length

Lee Song,Lee Ho,Lee Jae,Hwang Kyo,Park Soo,Yoon Seung,Kim Young
Jpn. J. Appl. Phys. 54(6S1), 06FG09, 2015-05-13
… Remarkably, the half-decay lifetime of a hybrid blue device with fluorescent and phosphorescent EML thickness of 5 and 25 nm, measured at an initial luminance of 500 cd/m<sup>2</sup>, has improved twice than that of using a conventional structure. …
NAID 150000110824

Related Pictures

★リンクテーブル★

リンク元	「輝度」「brightness」

「輝度」

　　[★]

英: intensity、brightness、luminance
関: インテンシティ、強度、明るさ

「brightness」

　　[★]

輝度、明るさ

関: intensity、luminance

[note-suffix-v-3] Standards organizations recommend that photometric quantities be denoted with a suffix "v" (for "visual") to avoid confusion with radiometric or photon quantities. For example: USA Standard Letter Symbols for Illuminating Engineering USAS Z7.1-1967, Y10.18-1967

[note-alternative-symbol-photometric-4] Alternative symbols sometimes seen: W for luminous energy, P or F for luminous flux, and ρ or K for luminous efficacy.

[note-dimension-J-5] "J" here is the symbol for the dimension of luminous intensity, not the symbol for the unit joules.

[1] "Luminance". Lighting Design Glossary. Retrieved Apr 13, 2009.

[2] Chaves, Julio (2008). "Introduction to Nonimaging Optics". Optical Science and Engineering 134. CRC Press. p. 449. ISBN 9781420054293.

Quantity		Unit		Dimension	Notes
Name	Symbol^{[nb 1]}	Name	Symbol	Symbol	Notes
Luminous energy	Q_v ^{[nb 2]}	lumen second	lm⋅s	T⋅J ^{[nb 3]}	Units are sometimes called talbots.
Luminous flux / Luminous power	Φ_v ^{[nb 2]}	lumen (= cd⋅sr)	lm	J ^{[nb 3]}	Luminous energy per unit time.
Luminous intensity	I_v	candela (= lm/sr)	cd	J ^{[nb 3]}	Luminous power per unit solid angle.
Luminance	L_v	candela per square metre	cd/m²	L⁻²⋅J	Luminous power per unit solid angle per unit projected source area. Units are sometimes called nits.
Illuminance	E_v	lux (= lm/m²)	lx	L⁻²⋅J	Luminous power incident on a surface.
Luminous exitance / Luminous emittance	M_v	lux	lx	L⁻²⋅J	Luminous power emitted from a surface.
Luminous exposure	H_v	lux second	lx⋅s	L⁻²⋅T⋅J
Luminous energy density	ω_v	lumen second per cubic metre	lm⋅s⋅m⁻³	L⁻³⋅T⋅J
Luminous efficacy	η ^{[nb 2]}	lumen per watt	lm/W	M⁻¹⋅L⁻²⋅T³⋅J	Ratio of luminous flux to radiant flux.
Luminous efficiency / Luminous coefficient	V			1
See also: SI · Photometry · Radiometry

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