ISO 25178-605:2014 幾何学的製品仕様（GPS）—表面テクスチャ：面積—パート605：非接触（ポイントオートフォーカスプローブ）機器の公称特性 | ページ 6

3.1.1

面積参照

表面トポグラフィーが測定される基準面を生成する機器のコンポーネント。

3.1.2

計器の座標系

軸の右側直交座標系 ( x,y,z )

注記 1:このシステム ( x,y ) では、平面は機器の面参照によって確立されます (物理的な面ガイドを持たない光学機器があることに注意してください)

注記 2:このシステムでは、 z軸は光軸に平行に取り付けられ、光学機器の ( x , y ) 平面に垂直です。 z軸はスタイラスの軌跡の平面内にあり、スタイラス器具の ( x , y ) 平面に対して垂直です (図 1 を参照)

注記 3通常、 x軸はトレース軸であり、 y軸はステップ軸です。 (この注記は、水平面でスキャンする機器に有効です。)

注記 4: ISO 25178‑2:2012, 3.1.2 および ISO 25178‑6:2010, 3.1.1 でそれぞれ定義されている仕様座標系および測定座標系も参照のこと。

3.1.3

測定ループ

ワークピースとプローブを接続するすべてのコンポーネントを含むクローズド チェーン。たとえば、位置決め手段、ワーク保持治具、測定スタンド、ドライブ ユニット、プロービング システム

注記 1: 図 1 を参照してください。測定ループは、測定の不確かさに影響を与える外部および内部の妨害を受けます。

図 1 —計器の座標系と測定ループ

Key

1	計器の座標系
2	測定ループ

3.1.4

ワークピースの実表面

物理的に存在し、ワークピース全体を周囲の媒体から分離する機能のセット

[出典:ISO 14660‑1:1999, 2.4]

注記 1:実表面は、測定プロセスとは独立した表面の数学的表現です。

注記 2: ISO 25178-2:2012, 3.1.1.1 または ISO 14406:2010, 3.1.1 で定義されている機械的表面、および ISO 25178-2:2012, 3.1.1.2 で定義されている電磁表面も参照してください。または ISO 14406:2010, 3.1.

注記3あるタイプの光学機器で考慮される電磁表面は、他のタイプの光学機器の電磁表面とは異なる場合があります。

3.1.5

表面サンプル

測定時に表面高さを信号に変換する装置

注記1:以前の規格では、これは変換器と呼ばれていました。

3.1.6

体積の測定

計器によって測定された 3 つの座標すべての限界に関して述べられた計器の範囲。

3.2.1

areal reference guide

component(s) of the instrument that generate(s) the reference surface, in which the probing system moves relative to the surface being measured according to a theoretically exact trajectory

Note 1 to entry: Note to entry: In the case of x- and y-scanning areal surface texture measuring instruments, the areal reference guide establishes a reference surface [ISO 25178-2:2012, 3.1.8]. It can be achieved through the use of two linear and perpendicular reference guides [ISO 3274:1996, 3.3.2] or one reference surface guide.

3.2.2

lateral scanning system

system that performs the scanning of the surface to be measured in the (x,y) plane

Note 1 to entry: There are essentially four aspects to a surface texture scanning instrument system: the x-axis drive, the y-axis drive, the z-measurement probe and the surface to be measured. There are different ways in which these may be configured and thus there will be a difference between different configurations as explained in Table 2.

3.2.3

drive unit x [ y ]

component of the instrument that moves the probing system or the surface being measured along the reference guide on the x-axis [y-axis] and returns the horizontal position of the measured point in terms of the lateral x-coordinate [y-coordinate] of the profile

3.2.4

lateral position sensor

component of the drive unit that provides the lateral position of the measured point

Note 1 to entry: The lateral position can be measured or inferred by using, for example, a linear encoder, a laser interferometer, or a counting device coupled with a micrometre screw.

3.2.5

speed of measurement

V_x

speed of the probing system relative to the surface to be measured during the measurement along the x-axis

[SOURCE:ISO 25178‑601:2010, 3.4.13]

3.2.6

static noise

N_S

combination of the instrument and environmental noise on the output signal when the instrument is not scanning laterally

Note 1 to entry: Environmental noise is caused by e.g. seismic, sonic and external electromagnetic disturbances.

Note 2 to entry: Notes 2 and 3 in 3.1.9 apply to this definition.

Note 3 to entry: Static noise is included in measurement noise (3.1.10)

3.2.7

dynamic noise

N_D

noise occurring during the motion of the drive units on the output signal

Note 1 to entry: Notes 2 and 3 in 3.1.9 apply to this definition.

Note 2 to entry: Dynamic noise includes the static noise.

Note 3 to entry: Dynamic noise is included in measurement noise (3.1.10) .

3.3.1

light source

optical device emitting an appropriate range of wavelengths in a specified spectral region

3.3.2

measurement optical bandwidth

B_λ0

range of wavelengths of light used to measure a surface

Note 1 to entry: Instruments may be constructed with light sources with a limited optical bandwidth and/or with additional filter elements to further limit the optical bandwidth.

3.3.3

measurement optical wavelength

λ₀

effective value of the wavelength of the light used to measure a surface

Note 1 to entry: The measurement optical wavelength is affected by conditions such as the light source spectrum, spectral transmission of the optical components, and spectral response of the image sensor array.

3.3.4

angular aperture

angle of the cone of light entering an optical system from a point on the surface being measured

[SOURCE:ISO 25178‑602:2010, 3.3.3]

3.3.5

half aperture angle

α

one half of the angular aperture

Note 1 to entry: This angle (see Figure 8) is sometimes also called half cone angle.

Figure 8—Half aperture angle

Key

L	lens or optical system
P	focal point
α	half aperture angle

3.3.6

numerical aperture

A_N

sine of the half aperture angle multiplied by the refractive index n of the surrounding medium (A_N = n sinα)

Note 1 to entry: In air for visible light, n ≅ 1.

Note 2 to entry: The numerical aperture is dependent on the wavelength of light. Typically the numerical aperture is specified for the wavelength that is in the middle of the measurement optical bandwidth.

3.3.7

Rayleigh criterion

quantity characterizing the spatial resolution of an optical system given by the separation of two point sources at which the first diffraction minimum of the image of one point source coincides with the maximum of the other

Note 1 to entry: For a theoretically perfect, incoherent optical system with a filled objective pupil, the Rayleigh criterion of the optical system is equal to 0,61 λ₀/A_N.

Note 2 to entry: This parameter is useful for characterizing the instrument response to features with heights much less than λ₀ for optical 3D metrology instruments.

3.3.8

Sparrow criterion

quantity characterizing the spatial resolution of an optical system given by the separation of two point sources at which the second derivative of the intensity distribution vanishes between the two imaged points

Note 1 to entry: For a theoretically perfect, incoherent optical system with a filled objective pupil, the Sparrow criterion of the optical system is equal to 0,47 λ₀/A_N, approximately 0,77 times the Rayleigh criterion (3.3.7) .

Note 2 to entry: This parameter is useful for characterizing the instrument response to features with heights much less than λ₀ for optical 3D metrology instruments.

Note 3 to entry: Under the same measurement conditions as the notes above, the Sparrow criterion is nearly equal to the spatial period of 0,50 λ₀/A_N, for which the theoretical instrument response falls to zero.

3.4.1

surface film

surface layer

material deposited onto another surface whose optical properties are different from that surface

3.4.2

thin film

film whose thickness is such that the top and bottom surfaces cannot be readily separated by the optical measuring system

Note 1 to entry: For some measurement systems with special properties and algorithms, the thicknesses of thin films may be derived.

3.4.3

thick film

film whose thickness is such that the top and bottom surfaces can be readily separated by the optical measuring system

3.4.4

optically smooth surface

surface from which the reflected light is primarily specular and scattered light is not significant

Note 1 to entry: An optically smooth surface behaves locally like a mirror.

Note 2 to entry: A surface that acts as optically smooth under certain conditions, such as wavelength range, numerical aperture, pixel resolution, etc., can act as optically rough when one or more of these conditions change.

3.4.5

optically rough surface

surface that does not behave as an optically smooth surface, i.e. where scattered light is significant

Note 1 to entry: A surface that acts as optically rough under certain conditions, such as wavelength range, numerical aperture, pixel resolution, etc., can act as optically smooth when one or more of these conditions change.

3.4.6

optically non-uniform material

sample with different optical properties in different regions

Note 1 to entry: An optically non-uniform material may result in measured phase differences across the field of view that can be erroneously interpreted as differences in surface height.

3.5.1

probing system

<surface texture, point autofocus probe> components of the instrument called point autofocus probe, consisting of an autofocus optical system, an autofocus mechanism and an electronic controller

3.5.2

point autofocus probe

device that converts the height of a point on a surface into a signal during measurement using the autofocus function

3.5.3

point autofocus profiling

surface topography measurement method whereby the local surface height is measured by automatically centring a focused light beam reflected from the sample onto a position sensitive detector as a function of surface height

[SOURCE:ISO 25178‑6:2010, 3.3.11]

3.5.4

objective

objective lens that focuses the light source image on to the workpiece surface

3.5.5

autofocus sensor

optical sensor that detects a focal position using the reflected light from the workpiece surface

3.5.6

autofocus mechanism

autofocus driving mechanism that positions optical elements or the whole optical system

3.5.7

z position sensor

sensor that measures the vertical position of the measured point

3.5.8

working distance

<point autofocus probe> distance measured along the optical axis between the element closest to the surface and the focus point on the surface

3.5.9

spot size

W_spot

<point autofocus probe> size that forms the focus image of the light source on the workpiece surface

3.5.10

focus range

range of z height, within which the focusing point exists

Note 1 to entry: Range where the autofocus sensor can detect the extreme defocused points.

3.5.11

vertical range

R_VERT

<point autofocus probe> measuring range that can output digital data with demonstrated measuring accuracy along a vertical direction in the movable range of the autofocus mechanism

3.5.12

measurable minimum reflection ratio

M_REF

minimum ratio of the reflected light intensity to the incident light intensity for a measurable workpiece surface

3.5.13

autofocus repeatability

R_af

measurement repeatability of the autofocus function that does not include environmental noise

3.5.14

speckle noise

uneven reflected optical intensity generated by irregular micro-scale geometry within the spot size