Spectrum management technology

The light as we said generally can be divided into natural light and artificial light. The natural light is the sunlight and the artificial light is the light made according to the spectrum of the sunlight. The wavelength of the solar spectrum is from 300nm UV light to the 2600nm infrared light. The wavelength of the visible light is from 380nm to 780nm. Therefore, the visible spectrum is also known as full spectrum (see fig.1). The purple light 380~435nm, the blue light 435~480nm, the cyan light 480~490nm, the blue and green 490~500nm, the green light 500nm~560nm, the yellow and green light 560~580nm, the yellow light 580nm~595nm, the orange light 595~605nm, the red light 605~780nm and the IR 780~1100nm.

Fig.1 Spectrum of the visible light

For light source, the most important thing is the spectrum, which determines the optical characteristics of the object. According to the visible light spectrum, many light sources and illuminators have been manufactured including A light, B light, C light, a series of D light and so on. These different lights can simulate the light environment of the sun at different times and represent the effect that is basically the same as the light sources in these specific environments. Such as A light, which simulates the sun rays at noon (Fig 2). D50 simulates The sun rays at nightfall (Fig 3).

　　　　　　　　　   　　　　Fig 2 the sun at noon(A light)                  　　    Fig 3 the sun at nightfall(D50)

Due to their optical characteristics, these kinds of A light, B light, C light, a series of D light can be applied to various industries such as color matching, device calibration, white balance and scene simulation. Reference standards also should be regulated for their spectral characteristics. In order to define the artificial light which is used to evaluate the color appearance, CIE (Commission Internationale de l´Eclairage) has formulated a series of standard illuminants and light. Its development can b divided into three periods: The first period is that CIE defined A,B and C lights as three standard illuminants and recommended corresponding standard lights in 1931. The second period is that a series of D light were formulated in 1967 to cover the shortage of the B light and C light in UV. It includes D50, D65 D75 and so on, which are UV, visible light and IR. The third period is that CIE has defined a series of F light after 1970 with the popularity of fluorescent lamp and its widely used in commerce. F1-F6 are common fluorescent lamps, F7-F9 have high CRI and F10-F12 are the tricolor fluorescent lamps. The emergence of the CIE standard illuminant make it possible to achieve accurate color identification in the industrial field. The color matching light is the artificial light which matches or partly match the CIE standard illuminant spectrum.

图四　各种CIE标准光谱曲线

For the spectral modulation, Scienca is at the forefront of its industry. When the fixed spectrum of the single CCT light source is generally used by most of the companies, our single CCT light source is available for spectral adjustment. When the single spectrum adjustment is available in the industry, we have achieved multiple spectra adjustable with their spectra conform to CIE standard and greatly matching the sunlight. What’s more, the spectrum real-time monitoring feedback system developed by Scienca can ensure the accuracy of the spectrum. Through the built-in spectrometer, it can be adjusted in a closed loop and it can be connected to the software to set the color temperature and brightness. The x and y value will be automatically calibrated. Our products are suitable for automatic and unmanned production

Four points to achieve Scienca’s spectrum management technology

一、LED light panel with multiple channels

To achieve the full spectrum of visible light and to modulate the spectrum of any kinds of visible light, firstly we have to solve the problem of full spectrum. We can integrate 24 ,40 or more groups of different types of LED beads into one light panel. Through the mutual combination of these different types of LED beads, the full spectrum whose wavelength is between 380-780nm can be achieved. So as any spectra among the full spectrum.

Spectral distribution diagram of the LED light panel with multiple channels

二、Reasonable light path structure

Since the problem of the full spectrum’s wavelength, the next problem is the light uniformity. It is known that uniformity is required in all visual light sources. Within a certain visual field of view, the light-emitting angle, color, brightness and light-emitting area of different groups of lamp beads are different. Different light sources require different light path structures. If each group of lamp beads does not have reasonable light path processing and just emits light directly at the same time, the light will be mottled, and messy. A reasonable design of the light path structure can make the light from each group of lamp beads merge together after passing through the light path, the light guide plate, reflective film and diffuser so that the color temperature and illuminance uniformity of the surface can be higher than 95%.

Diagram of the light path structure

三、Spectral adjustable software

The software realizes the dimming method that there are corresponding dimming channels according to the groups of lamp beads. For example, there are 24 sets of channels for the 24 groups of lamp beads and 40 sets of channels for 40 groups of lamp beads. When using the software, firstly, it is to use a variety of spectral models that are preset. Secondly, it is to directly use the customer's spectral model and the third one is to modulate the spectra currently. The blue line templat is displayed on the software after the model is set. When verifying the current spectrum, monitoring the spectrum of the red line through a micro spectrometer and act is displayed. Comparing the template and the act and make the adjustment by the dimming channels.

光谱可调软件示意图

四、Spectrum real-time monitoring feedback system

In order to guarantee the product quality, Scienca has developed a real-time spectrum monitoring feedback system. In the case of full-spectrum light source,a micro spectrometer SCN-380~780-SIS is built in to read and monitor spectral data in real time, which can output the real-time color temperature brightness and x, y values. All there statistics can be showed in the upper computer. The micro spectrometer has the same function of the CL-500A. Therefore, customers can monitor the statistics in real time without using the instrument to artificial operation. Timely adjustment can be achieved if the statistics is out of standard so that the defect rate caused by the light source can be prevented.

Inser spectrum

Spectrum real-time monitoring feedback diagram