When people face the question of what color is, they always think it is a very simple question. if someone asks the child what color the apple is, the children will say in unison: red. But if you ask again, what is red? Often, people get confused in this question. "A tree falls in a deep forest. if no one hears it, will it make a sound? " The answer is that the tree emits sound waves when it falls, but it is not a sound until the human brain receives it. it is a sound only when the brain receives the sound wave and explains it. For the question of color, the answer is the same. Color is the cognition of the interaction between the human eye and the brain to a very small range of electromagnetic waves. the so-called red, green and blue are all classified by the human brain according to experience.
The spectrum that the eye can see is called the visible region. Light is energy, consisting mainly of a small part of an electromagnetic spectrum, such as radio and television signals. Electromagnetic waves used in radio and television generally use frequencies. Visible light can be expressed as a frequency, but for reasons of magnitude. For SMD color
detection, people generally use the following methods:
1. human eye recognition: depending on the eye observation of the operator to judge whether the SMD LED color
and brightness are correct or not. The advantage of this method is simple, and the disadvantage is that it depends entirely on people to judge. Because of the poor discipline of the personnel, the quality of the product can not be controlled, at the same time, it can not be automated.
2. professional surface mount device LED
automation tester: this method is to import the light from optical fiber to SMD LED into the SMD LED automation tester. After analyzing the light in the SMD LED automation tester, it generally returns values for colors and brightness in a variety of formats, such as RGB, Hue, saturation, brightness, XY value, and so on. This method has high accuracy and high degree of automation. The downside is that there is an additional cost.
3. industrial camera: use the industrial camera to take pictures of the SMD LED, and then analyze the image to determine the color and brightness of the SMD LED. This approach has the advantage of testing a very large number of SMD LED at a time, but it also has problems such as insufficient accuracy.