Let's first understand what is a reflective cup?
Reflective cup refers to a reflector that uses a point source light bulb as a light source. A reflector that requires long-distance concentrated illumination, commonly known as a reflector, is a type of reflective device. In order to utilize limited light energy, the light distance of the main spot is controlled by a light reflector. And the area of the light.
The person who knows a little about the flashlight should be familiar with the reflector. Most of the
spotlight flashlights are reflective cups. The theoretical knowledge is there. What is the reflection cup?
The geometric parameters of the reflector mainly include the following:
· Distance between the center of the light source and the top surface of the reflector
· Reflector top opening diameter D
· Light exit angle B after reflection
· Spilled light angle A
· Irradiation distance L
· Center spotlight spot diameter E
· Spilled light spot diameter F
The relationship of geometric parameters is as follows:
1. The outer dimensions of the reflector are mainly determined by the size of H and D. H and D also determine the angle of overflow light A;
2. The diameters E and F of the spot are determined by the exit angles B, A and the distance L;
3. The most critical angle B is determined by the reflective surface of the reflector.
For the reflector, the design of the reflector is mainly to design the reflection curve. The above parameters of H, D and B determine the reflection curve. Therefore, for the reflector, the design of the reflector only needs to provide H. D, B three parameters. The external dimensions are determined by the actual application.
Reflective cup material:
Reflective cups are made of plastic, aluminum alloy and glass. The optical precision, temperature resistance and impact resistance of different materials are different.
Each material has its advantages and disadvantages. What kind of reflective cups are required for the flashlight should be selected according to the product positioning.
Reflective cup coating process:
Reflectivity is also known as the efficiency of the coating layer to reflect visible light. Different coatings have different reflectivities, but the general ranking is vacuum plating meson>vacuum aluminizing>anodizing.
1. Vacuum plating meson: applied to glass reflectors. The meson not only has the highest visible reflectivity, but the infrared light generated by the bulb can also pass through the meson to provide heat dissipation and extend the life of the light.
2. Vacuum aluminum plating: applied to metal reflectors. The high reflectivity is the main coating process for automobiles and most lamps. The disadvantage is that the ultraviolet light generated by the bulb will whiten the reflector and reduce the reflectivity: the infrared rays cannot penetrate the aluminized layer and are reflected back to the bulb, so that the bulb continues to heat up and affect the service life of the bulb.
3. Anodizing: applied to metal reflectors. The effective reflectance is less than half that of vacuum aluminum plating. The advantage is that it is not afraid of UV, infrared damage, and even can be washed with water.