What changes have been made in the functions and styles of lamps since ancient times?

Functions: decorative lighting, heating, transmitting signals, adjusting atmosphere, ultraviolet rays can also sterilize, and black light can trap and kill pests.

Change: Humans have a long history of using oil lamps for lighting. During this period, the oil lamp was improved many times. Oil for oil lamps changed from animal oil to vegetable oil, and was finally replaced by kerosene. Wick has also experienced the change process of grass, cotton thread and multi-strand cotton thread. In order to prevent the wind from blowing out the fire, people put a cover on the oil lamp. Early covers were made of paper, which was very unsafe. Later, it was changed to a glass cover. This kind of oil lamp is not afraid of the wind, and can be used outdoors, and it burns fully without black smoke.

However, mankind is not satisfied. While lighting with oil lamps, they are still looking for other lighting methods. Around the 3rd century BC, people made candles with beeswax. /kloc-in the 0/8th century, candles made of paraffin appeared and began to be mass-produced by machines.

/kloc-more than 0/00 years ago, the British invented the gas lamp, which made a big step forward in human lighting. At first, this kind of lamp was very unsafe and dangerous when used indoors, so it was only used as a street lamp. Later, after improvement, it entered thousands of households.

Torches, candles, oil lamps, kerosene lamps, gas lamps, these lighting tools, have not left the fire, all rely on the light emitted by the burning of substances to illuminate. So is there any way to light it without fire? Someone once caught a large number of fireflies and used their fluorescence to illuminate. Although this method is not practical, it is the strangest method in the history of human lighting.

/kloc-at the end of 0/9, Edison invented the electric light, which rewrote the history of human lighting and made mankind move towards the electric light age.

Light bulb (incandescent lamp): the current in the wire enters the extremely thin metal wire, which will generate high heat and emit light to a certain extent.

Fluorescent lamp: it does not contain infrared rays, so the light is very mild and does not hurt the eyes; Because there is no hotline, it is more energy-saving to use; It also gives off many beautiful and colorful lights. This is determined by the properties of the chemicals contained in the phosphor, such as those coated with magnesium tungstate emitting blue-white light and those coated with cadmium borate emitting light red light.

Steam lamp: It is made of all kinds of steam sealed in a glass tube and ignited by electric current. Their structure, a bit like fluorescent lamps, can also save electricity. Steam lamps include mercury vapor lamps and sodium vapor lamps.

The next generation of new lighting source is LED lamp, that is, the lighting lamp made of high brightness light emitting diode. It has a series of advantages such as high efficiency, energy saving, long life and environmental protection.