ISO/TR 10688:2015 紙、板、パルプ—光学特性の基本的な用語と方程式 | ページ 5

2.1.1

ISO brightness, R457

diffuse blue reflectance factor, UV level C

intrinsic diffuse radiance (reflectance) factor measured with a reflectometer having the characteristics described in ISO 2469, equipped with a filter or corresponding function having an effective wavelength of 457 nm and a half bandwidth of 44 nm, and adjusted so that the UV content of the irradiation incident upon the test piece corresponds to that of the CIE illuminant C

Note 1 to entry: The filter function is described more fully by the weighting function factors given in ISO 2470-1, Annex A.

[SOURCE:ISO 2470‑1:2009, 3.4, modified]

2.1.2

D65 brightness, R457 _D65

diffuse blue reflectance factor, UV level D65

intrinsic diffuse radiance (reflectance) factor measured with a reflectometer having the characteristics described in ISO 2469, equipped with a filter or corresponding function having an effective wavelength of 457 nm and a half-peak bandwidth of 44 nm, and adjusted so that the UV content of the irradiation incident upon the test piece corresponds to that of the CIE standard illuminant D65

Note 1 to entry: The filter function is described more fully by the weighting function factors given in ISO 2470-2, Annex A and Table A.1.

[SOURCE:ISO 2470‑2:2008, 3.4, modified]

2.2

CIE colour matching functions

functions in the CIE 1931 standard colorimetric system describing the tristimulus values X, Y, Z for monochromatic colour stimuli of equal radiance and where the wavelength λ is a variable

2.3

CIE colour matching functions

functions in the CIE 1964 standard colorimetric system describing the tristimulus values X₁₀, Y₁₀, Z₁₀ for monochromatic colour stimuli of equal radiance and where the wavelength λ is a variable

2.4

chromaticity coordinates

ratio of each of a set of three tristimulus values to their sum

Note 1 to entry: As the sum of the three chromaticity coordinates is equal to one, two of them are sufficient to define a chromaticity.

Note 2 to entry: In the CIE standard colorimetric systems, the chromaticity coordinates are represented by the symbols x, y, z and x₁₀, y₁₀, z₁₀.

[SOURCE:CIE S 017/E:2011 ILV, 17-145]

2.5

CIELAB colour space

three-dimensional approximately uniform colour space, produced by plotting in rectangular coordinates L*, a*, b* quantities defined by the formulae given in 3.7

[SOURCE:ISO 5631‑3:2014, 3.6, modified]

2.5.1

CIELAB colour (C/2°)

L*, a* and b* values of the sample according to the CIELAB 1976 system, evaluated according to the CIE 1931 (2°) standard colorimetric observer and the CIE illuminant C

2.5.2

CIELAB colour (D65/10°)

L*, a* and b* values of the sample according to the CIELAB 1976 system, evaluated according to the CIE 1964 (10°) standard colorimetric observer and the CIE standard illuminant D65

2.5.3

CIELAB colour (D50/2°)

L*, a* and b* values of the sample according to the CIELAB 1976 system, evaluated according to the CIE 1931 (2°) standard colorimetric observer and the CIE illuminant D50

2.5.4

CIELAB colour difference

distance in the CIELAB colour space between two colour stimuli

2.6

effective residual ink concentration

ERIC number

ratio of the light absorption coefficient of pulp or paper containing ink to the light absorption coefficient of the ink itself, both being determined at a wavelength of 950 nm

Note 1 to entry: The ERIC number is dimensionless.

[SOURCE:ISO 22754:2008, 3.6]

2.7

fluorescence component

F_B,SorF_W,S for specified CIE illuminant

S

fluorescence component is used as a measure of the extent to which the brightness (F_B) or whiteness (F_W) of the material is affected by emission from added fluorescent whitening agent (FWA) when the light source of the specified CIE illuminant (S = C or D65) emits UV radiation

Note 1 to entry: Relevant standards: ISO 2470-1, ISO 2470-2, ISO 11475, ISO 11476.

2.8

fluorescent whitening agent

FWA

fluorescing materials absorbing ultraviolet light and converting it into visible blue light

Note 1 to entry: The fluorescing light adds to light reflected by the pulp in the blue range and compensates for the absorbed share of the light.

Note 2 to entry: The absorption maximum of the usual FWAs is around 360 nm in the UV range and their maximum of emission is in the blue range of the visible light at approximately 440 nm. By this fact, the yellow tint of the bleached pulp is compensated and seen by the human eye as white.

Note 3 to entry: FWAs in paper can only be effective when they are exposed to a light source with an adequate component of UV light. Light emitted by incandescent lamps and some LEDs have practically no UV component, ie radiation with a wavelength of less than 400 nm. FWAs are not sufficiently activated by such light sources. Daylight does contain an adequate UV component although the intensity of the light and the relative contribution of the UV component depends on the time of day, time of the year, geographical standpoint, weather conditions, etc.

Note 4 to entry: This term is often equivalent to optical brightening agent (OBA) (2.25) .

[SOURCE:Bayer Blankophor — fluorescent whitening agents for the paper industry]

2.9

gloss

<of a surface> mode of appearance by which reflected highlights of objects are perceived as superimposed on the surface due to the directionally selective properties of that surface

[SOURCE:CIE S 017/E:2011 ILV, 17-500]

2.10

illuminant

radiation with a relative spectral power distribution defined over the wavelength range that influences object colour perception

Note 1 to entry: In everyday English, this term is not restricted to this sense, but is also used for any kind of light falling on a body or scene.

[SOURCE:CIE S 017/E:2011 ILV, 17-554]

2.11

light-scattering coefficient

s

fraction of the spectral radiant flux diffusely incident on a differential layer within a material that is reflected when the flux passes through the layer, divided by the thickness of the layer

Note 1 to entry: The flux referred to is a radiant flux across the differential layer.

Note 2 to entry: It is assumed that no reflection occurs at the boundaries of the material.

Note 3 to entry: In a two-flux system, the scattering coefficient is equal to the net transfer of flux from the stronger flux to the weaker flux in a differential layer within a material divided by the product of the thickness of the layer and the difference between the fluxes.

[SOURCE:ISO 9416:2009, 3.7]

2.12

light-scattering coefficient by reflectance factor measurements

s_v

<Kubelka-Munk method> coefficient calculated by application of the Kubelka-Munk equations to luminance factor data weighted with respect to the CIE illuminant C, obtained in an instrument having a specified geometry and calibrated in a specified manner, on the basis of grammage

Note 1 to entry:s_v is expressed in square metres per kilogram (m²/kg).

2.13

light scattering coefficient at 950 nm by reflectance factor measurements

s₉₅₀

<Kubelka-Munk method> coefficient calculated by application of the Kubelka-Munk equations to reflectance factor data obtained at a wavelength of 950 nm in an instrument having a specified geometry and calibrated in a specified manner and taking into consideration the grammage

Note 1 to entry: Units: m²/kg.

Note 2 to entry: The relevant equations are given in ISO 22754, Clause 9.

[SOURCE:ISO 22754:2008, 3.4, modified]

2.14

light-absorption coefficient

k

fraction of the spectral radiant flux diffusely incident on a differential layer within a material that is absorbed when the flux passes through the layer, divided by the thickness of the layer

Note 1 to entry: The flux referred to is a radiant flux across the differential layer.

[SOURCE:ISO 9416:2009, 3.6]

2.15

light-absorption coefficient by reflectance factor measurements

k_v

<Kubelka-Munk method> coefficient calculated by application of the Kubelka-Munk equations to luminance factor data weighted with respect to the CIE illuminant C, obtained in an instrument having a specified geometry and calibrated in a specified manner, on the basis of grammage

Note 1 to entry:k_v is expressed in square metres per kilogram (m²/kg).

Note 2 to entry: light-scattering coefficient (2.11) and light-absorption coefficient (2.14) are strictly applicable to monochromatic light but, for the purpose of this International Standard, the relevant light absorption and scattering coefficients apply to broad-band radiation. In research work, s_v and k_v can and should be determined at the relevant wavelength for the study concerned. As general descriptions of a given paper, they are defined here in relation to the function and the CIE illuminant C.

[SOURCE:ISO 9416:2009, 3.9, modified]

2.16

light absorption coefficient at 950 nm by reflectance factor measurements

k₉₅₀

<Kubelka-Munk method> coefficient calculated by application of the Kubelka-Munk equations to reflectance factor data obtained at a wavelength of 950 nm in an instrument having a geometry according to ISO 2469 and having been calibrated as specified in ISO 2470-1 and ISO 11475 and taking into consideration the grammage

Note 1 to entry: Units: m²/kg.

Note 2 to entry: The relevant equations are given in ISO 22754, Clause 9.

[SOURCE:ISO 22754:2008, 3.5]

2.17

luminance factor (C),

luminous reflectance factor, Y(C/2°)-value

reflectance factor defined with reference to the spectral luminous efficiency function and the CIE illuminant C

Note 1 to entry: The visual efficiency function describes the sensitivity of the eye to light so that the luminance factor corresponds to the attribute of visual perception of the reflecting surface.

Note 2 to entry: For computational purposes, the .

Note 3 to entry: The luminance factor (C) is also known as the Y(C/2°)-value. In previous editions of ISO 9416 and ISO 2471, it was referred to as the luminous reflectance factor.

Note 4 to entry: The CIE term"luminance factor" is a more general term since it does not specify the illuminant or observer condition.

2.18

single-sheet luminance factor (C)

luminance factor (C) of a single sheet of paper with a black cavity as backing

[SOURCE:ISO 9416:2009, 3.3, modified]

2.19

intrinsic luminance factor (C)

luminance factor (C) of a layer or pad of material thick enough to be opaque, i.e. such that increasing the thickness of the pad by doubling the number of sheets results in no change in the measured reflectance factor

[SOURCE:ISO 9416:2009, 3.4, modified]

2.20

spectral luminous efficiency

for photopic vision

ratio of the radiant flux at wavelength is chosen so that the maximum value of this ratio is equal to one

Note 1 to entry: Function describing the sensitivity to light of the human eye at different wavelengths.

Note 2 to entry:

Note 3 to entry: For computational purposes, the function for the CIE 1931 (2°) standard observer.

[SOURCE:CIE S 017/E:2011, 17-1222]

2.21

metameric colour stimuli

spectrally different colour stimuli that have the same tristimulus values in a specified colorimetric system

Note 1 to entry: Equivalent term:"metamers".

Note 2 to entry: The corresponding property is called"metamerism".

[SOURCE:CIE S 017/E:2011: ILV, 17-768 and 17-769]

2.22

metamerism index

degree of colour mismatch, calculated in the form of a colour difference, caused by substituting a test illuminant (observer) of different relative spectral composition (responsivity) for the reference illuminant (observer)

Note 1 to entry: The colour difference is evaluated using a CIE colour difference formula and it should be clearly stated which formula has been used.

[SOURCE:CIE S 017/E: 2011: ILV, 17-770]

2.23

diffuse reflectance factor

diffuse radiance factor

for the purpose of this Technical Report, only diffuse reflectance factor is considered.

Note 1 to entry: For non-fluorescent materials, the diffuse radiance factor, β, is simply the diffuse reflectance factor, R.

2.23.1

diffuse reflectance factor

R

ratio of the radiation (reflectance) reflected and emitted from a body to that reflected from the perfect reflecting diffuser under the same conditions of diffuse illumination and normal detection

Note 1 to entry: The ratio is often expressed as a percentage.

Note 2 to entry: In the context of ISO 2469 and related standards, the irradiation is diffuse and the direction of detection is perpendicular to the surface of the specimen (d:0 geometry). A gloss trap ensures that there is negligible irradiation from directions close to the direction of detection.

Note 3 to entry: This term is often expressed simply as reflectance factor.

[SOURCE:ISO 2469:2014, 3.5, modified]

2.23.2

intrinsic diffuse reflectance factor

R_∞

diffuse reflectance factor of a layer or pad of material thick enough to be opaque, i.e. such that increasing the thickness of the pad by doubling the number of sheets results in no change in the measured diffuse reflectance factor

Note 1 to entry: The diffuse reflectance factor of a single non-opaque sheet is dependent on the background and is not a material property.

[SOURCE:ISO 2469:2014, 3.6, modified]

2.23.3

spectral diffuse reflectance factor

reflectance factor expressed as a function of wavelength

Note 1 to entry: In this Technical Report, a wavelength-specific reflectance factor is indicated as .

2.24

opacity

ratio of the single-sheet luminous reflectance factor (C), , of the same sample

Note 1 to entry: The single-sheet reflectance factor is defined as the reflectance factor of a single sheet of paper with a black cavity as backing.

2.25

optical brightening agent

OBA

see fluorescent whitening agent (2.8)

Note 1 to entry: This term is often equivalent to fluorescent whitening agent (FWA).

2.26

source

object that produces light or other radiant flux

[SOURCE:CIE S 017/E:2011, 17.1202]

2.27

CIE tint,

green/red tint

measure of the deviation from CIE whiteness of the test material towards the green or red region

Note 1 to entry: The deviation is expressed as CIE tint units.

Note 2 to entry: A positive value of T_worT_w,10 indicates a greenish tint and a negative value indicates a reddish tint.

Note 3 to entry:T_w refers to C/2° conditions and T_w,10 refers to D65/10° conditions.

2.28

transmittance

ratio of the transmitted radiant or luminous flux to the incident flux under given conditions (CIE Publ 17.4 - 845-04-59)

[SOURCE:ISO 22891:2013, 3.6]

2.29

regular transmittance

ratio of the regularly transmitted part of the (whole) transmitted flux to the incident flux (CIE S 0117/E:2011 ILV, 17-1079)

[SOURCE:ISO 22891:2013, 3.7]

2.30

diffuse transmittance

ratio of the diffusely transmitted part of the (whole) transmitted flux to the incident flux (CIE S 017/E: 2011 ILV, 17-308)

Note 1 to entry:

[SOURCE:ISO 22891:2013, 3.8]

2.31

transmittance from luminous reflectance factor measurement

T_y

transmittance obtained by measurement of reflectance factors and subsequent calculation as defined in ISO 22891

2.32

tristimulus values

X, Y, Z

X₁₀, Y₁₀, Z₁₀

amounts of the three reference colour stimuli, in a given chromatic system, required to match the stimulus considered

Note 1 to entry: Depending on the observer conditions, the tristimulus values are represented differently.

Note 2 to entry: In ISO 5631-1, the CIE 1931 (2°) standard observer and the CIE illuminant C are used to define the trichromatic system.

Note 3 to entry: In ISO 5631-2, the CIE 1964 (10°) standard observer and the CIE standard illuminant D65 are used to define the trichromatic system.

Note 4 to entry: In ISO 5631-3, the CIE 1931 (2°) standard observer and the CIE illuminant D50 are used to define the trichromatic system.

Note 5 to entry: The tristimulus values (X, Y, Z) without subscript are used for the CIE 1931 (2°) standard observer. The subscript 10 is used for the CIE 1964 (10°) standard observer

[SOURCE:ISO 5631‑3:2014, 3.5, modified]

2.33

dominant wavelength

λ_d

<of a colour stimulus> wavelength of the monochromatic stimulus that, when additively mixed in suitable proportions with the specified achromatic stimulus, matches the colour stimulus considered in the CIE 1931 x, y chromaticity diagram

Note 1 to entry: Unit: nm.

Note 2 to entry: In the case of purple stimuli, the dominant wavelength is replaced by the complementary wavelength

[SOURCE:eILV of the Jan 2014 CIE website, 17.345]

2.34

CIE-whiteness

W

measure of CIE whiteness derived from the CIE tristimulus values determined under the conditions specified in relevant International Standard (ISO 11475, ISO 11476)

Note 1 to entry: The CIE whiteness is expressed in CIE whiteness units.

Note 2 to entry: The observer and illuminant should be specified as a suffix, e.g. .

Note 3 to entry: If the sample is fluorescent, the UV content in the radiation falling on the sample should correspond to UV(D65) or UV(C) conditions, respectively, to meet the requirements of ISO 11475 or ISO 11476.

Note 4 to entry: For paper and board and for outdoor daylight conditions, , i.e. C/2°, is used.

2.35

yellowness index

yi

measure of the extent to which a nearly achromatic stimulus deviates in yellowness from an achromatic stimulus having the same Y-value