[Expertise] What is gloss? 光沢とは?

25/06/2024

What is gloss? 光沢とは?

When we look at a metal object visually and it is illuminated by light, the reflective effect is called "gloss". However, everyone has different feelings about the degree of gloss, so it is necessary to use instruments to standardize and digitize it. Regarding the principle of light projection, we use the following two pictures to briefly explain each:
金属物体を目で見て光に照らされたときの反射効果を「光沢」といいます。ただし、光沢の度合いは人それぞれ感じ方が異なるため、機器を使って統一し数値化する必要があります。光の投影原理について、次の 2 つの図を使用して簡単に説明します。

First, we first set the input light as "incident light", and select a material surface as the "reflective surface", with an angle of 90 degrees to the reflective surface as N.

When light is thrown into the reflective surface, an incident angle i is obtained (as shown in Figure 1). When the material surface is a smooth plane, the reflection angle r of the reflected light will be the same as the incident angle i, and a normal reflected light will appear. Visually what we observe is like a mirror effect.

When the incident light is thrown into the reflective surface, the reflected light cannot be projected normally and is diffused. What is observed through visual inspection is the roughening effect.

まず、入力光を「入射光」とし、「反射面」として材料面を選択し、反射面に対して90度の角度をNとします。

反射面に光が入射すると、入射角 i が得られます (図 1 に示すように)。材料表面が滑らかな平面の場合、反射光の反射角 r は入射角 i と同じになります。通常の反射光が現れ、視覚的には鏡効果のように見えます。

入射光を反射面に入射すると、反射光が正常に投影できずに拡散してしまうのが目視で確認できる現象です。

Common names for gloss 光沢の通称

GLOSS UNIT (GU): Glossiness unit

GS: represents the incident angle of light (GS60=> incident angle 60 degrees)

GLOSS UNIT(GU):光沢度の単位

GS:光の入射角を表します(GS60=>入射角60度)

Gloss measuring instrument 光沢測定器

A common gloss meter is shown on the right
Single angle gloss meter YG60
Measurable value 0 ~ 1000 GU
Similar models are commonly used on the market

右は一般的な光沢計です。

シングルアングル光沢計 YG60

測定可能値 0~1000GU

同様のモデルが市場で一般的に使用されています