Foreword
LED is generally considered to be the mainstream lighting technology of the next generation due to its power-saving and environmental protection characteristics. Governments of various manufacturers and countries are optimistic about this technology and have invested a lot of resources. However, today, LED lighting is relatively expensive. The development of the market has never been as expected. In addition to price factors, LED lighting specifications are uneven, uneven quality, unpredictable reliability, etc., are also obstacles to the LED lighting market. In view of this, various LED lighting standards have been introduced, and many measurement methods have been written. For example, IES LM-79 has standardized measurement methods such as integrating spheres and distributed brightness meters. However, the standard specification method often only considers accuracy, and other factors such as convenience in use, time required for testing, etc. are often ignored, so that the measurement method specified by the standard can only be applied in the laboratory, such as an integrating sphere. The convenience of loading and unloading parts with the distributed brightness meter, the space and time required for testing, etc., make it difficult to use in the production line, but only a small amount of testing in the laboratory has limited help for the overall quality improvement of LED lighting products It also makes it difficult for consumers to accept LED lighting products more widely.
System principle
If there is a test method that can satisfy 1) convenient loading and unloading of parts, 2) the size of the equipment is moderate, 3) the measurement time is fast, 4) the test cost is low, 5) the measured value can have a good comparison result with laboratory equipment Can meet these conditions, LED lighting products in the production line 100% test will be feasible, LED lighting product quality problems can no longer be criticized by consumers.
Therefore, if the photodetector can be covered in a proper way around the LED test object, the measurement device itself will only be slightly larger than the size of the test object, and the measurement device is also easier to integrate with automation .
Zhimao Electronics has introduced an innovative measurement method, using a mono-crystalline silicon solar cell (mono-crystalline silicon solar cell) as a light detector, which is properly covered around the object to be measured, as shown in the bulb test in Figure 1 and Figure 2 The lamp test structure uses the photoelectric conversion principle of the solar panel, and the relatively large area and low cost of the solar panel. All photoelectric parameter tests of each LED bulb can be completed within six seconds, realizing the possibility of online testing in production.
The method uses the characteristic that the energy received by the solar panel can be converted into electricity to achieve the purpose of light energy detection. The response of the general commercial monocrystalline silicon solar panel to the wavelength is shown in Figure 3. The figure shows the actual measurement data of the wavelength response of the three solar panels. It can be seen from the figure that within the general LED wavelength application range, monocrystalline silicon Solar panels can have a good response. The current value of the solar panel's short-circuit current is a function of the received light energy. From this characteristic, the energy of the light emitted by the LED lighting product can be known by measuring the value of this short-circuit current. That is its lumen value. Of course, the quality of the solar panel must undergo a strict screening process before it can be used as a light detector. For example, the response of each area on each solar panel must be consistent.
Usually, there are certain restrictions on smart portable projectors in 2 aspects:
1. Size: Usually the size is the size of a mobile phone.
2. Battery life: It is required to have at least 1-2 hours or more of battery life without power connection. In addition, its general weight will not exceed 0.2Kg, and some do not even need fan cooling or ultra-small silent fan cooling. Can be carried with you (it can be put into a pocket, the screen can be projected to 40-50 inches or more, so sometimes we also call it a pico projector or a pocket projector.)
smart portable projector,smart portable projector for iphone,best smart portable projector 2020,cheap smart portable projector,mini smart portable projector wifi
Shenzhen Happybate Trading Co.,LTD , https://www.szhappybateprojectors.com