[Expertise] What is the purpose of the color matching light box?

What is a color matching light box?

Before we discuss light color we need to explain what a "color-matching light box" is. It is mainly used for color detection equipment. When we need to inspect the developed or produced finished products, we can clearly detect the difference between the main color and the color to be compared by using different light colors in the light box.

Light box inspection

There are several specifications regarding the use of light boxes for inspection, and here is a brief explanation of each:

• Lightbox environment settings

In order to clearly compare colors without interference in the environment where color comparison is carried out, there are clear settings for the color in the light box. Generally, N5-N7 neutral gray paint is selected as the color in the light box. This color is suitable for inspection. Easier to identify and less susceptible to interference.

• Inspection angle

Generally, there are two types of angles during inspection, one is zero degree inspection and the other is 45° inspection.

• Sample inspection location

The best position for sample testing is the center. If multiple samples need to be compared, they should be tested side by side.

• Light source output

Before conducting the inspection, it is necessary to observe the condition of each lamp. If there is any abnormality, it should be replaced immediately to avoid affecting the measured results.

Commonly used light colors

Currently, there are five main types of light sources used in the industry: F/A, D65, TL84, UV and CWF. Let's briefly introduce them.

• CWF   The full name of CWF in English is Cool White fluoresent, the color temperature is 4150 K

This light is a cool white light that is often seen in shopping malls and offices in the United States. It complies with the CIE (International Commission on Illumination) standard setting. Its characteristic is that the main cold white light contains a large amount of green and a small amount of red light sources.

• TL84    color temperature is 4000 K

TL84 has a three-primary color fluorescent source with high light efficiency and color rendering power. It is a neutral white light that can restore the true color of the object being illuminated. Because this color has excellent lighting effects, it is often used in shopping mall lighting and product displays.

• D65    color temperature is 6500 K

D65 is the most commonly used artificial light source among standard color matching light sources. Because it is close to the color of natural sunlight in the north, many manufacturers will specify this color for color matching.

• F/A    color temperature is 2700 ~2856 K (F color temperature is 2700 K, A color temperature is 2856 K)

When using a light box, you sometimes find that the panel has an F/A option, but some models have two independent options: F and A. The main reason is that the filament boxes of the F and A light sources are the same and have similar color temperatures, so some models have Will merge them together. The light color is a warm white light source. This light source can accurately display warm-toned color sources. If other light sources are used, there will be slight differences. It can be said that it is a common light source used to evaluate warm colors.

• UV wavelength 365nm

UV ultraviolet irradiation light source is a commonly heard light source in the industry. Its main functions are product color fastness evaluation, color matching proofing, color difference determination and fluorescent material identification, etc.

The picture below is a schematic diagram of color temperature. This table is often used to confirm the color of light bulbs in daily life.

When making color judgments, there are often large errors through visual inspection. In addition to using a colorimeter for analysis, the other is to use a light box to make judgments. Different colors of light can be used to assist in judging product color differences. This product is developed or One of the necessary equipment for manufacturers.