Analysis on the classification and light source of courtyard lights
Since the development of courtyard lights, according to the different use environment and design styles, different types have been derived, which are divided into three categories: European-style courtyard lights, modern courtyard lights, and classical courtyard lights.
European style garden lights:
Its design style mostly adopts some European art elements from European countries, and adds abstract expressions.
Modern courtyard lights:
Its design style mostly adopts modern artistic elements, and adopts simple techniques to express.
Classical courtyard lights:
Its design mostly adopts Chinese classical elements, which are used and modified, such as palace lanterns.
These three types of courtyard lights represent different styles and are derived by most manufacturers to cater to the design styles of urban buildings.
The light source is an important part of all lighting products. According to different illuminance requirements, different brands and different types of light sources can be selected. Commonly used light sources are: incandescent lamps, energy-saving lamps, fluorescent lamps, sodium lamps, metal halide lamps, ceramic metal halide lamps, And a new type of LED light source. Characteristics of each light source:
1. Incandescent lamp
Incandescent luminescence refers to the visible photoelectric radiation generated by atoms excited by heat. The incandescent lamp uses the principle of incandescent light to let current pass through the tungsten filament in a vacuum, and the tungsten filament is heated to incandescence and emits visible light. The color temperature of ordinary incandescent lamps is 2800K, which is more yellowish than natural light and looks warm. The advantages and disadvantages of incandescent lamps: low cost, easy to use and install. It is suitable for frequent turning on, and the impact on the performance and life of the lamp is very low.
The advantages and disadvantages of incandescent lamps:
Short life and low luminous efficacy. The visible light radiation emitted by the incandescent lamp is generally less than 10% of the electric energy, and most of the energy is converted into infrared radiation, which generates a lot of heat. In addition, the ultraviolet radiation emitted by the incandescent lamp is also relatively high, which will cause the fading of the irradiated article.
2. Fluorescent lamps, energy-saving lamps
Fluorescent lamps and energy-saving lamps are a kind of low-pressure mercury vapor arc discharge lamps, usually long tubular, with an electrode at each end. The lamp contains low-pressure mercury vapor and a small amount of inert gas, and the inner surface of the lamp tube is coated with a phosphor layer. Fluorescent lamps are divided into straight tube fluorescent lamps and compact fluorescent lamps. Straight tube fluorescent lamps can be divided into preheating start, quick start and instant start according to the starting mode, and can be divided into T12, T8 and T5 according to the tube. The compact fluorescent lamp was developed to replace the incandescent lamp that consumes a lot of power, and has the characteristics of low energy consumption and long life. The life of ordinary incandescent lamps is only 1000 hours, and the typical life of compact fluorescent lamps is 8000-10000 hours.
Advantages and disadvantages of fluorescent lamps and energy-saving lamps:
The main advantage of fluorescent lamps is high luminous efficacy. The visible light emitted by a typical fluorescent lamp is approximately 28% of the input power. The geometric size of the tube, the filling gas and pressure, the phosphor coating, the manufacturing process, and the ambient temperature and power frequency will all have an impact on the luminous efficacy of the fluorescent lamp. The color of the light emitted by the fluorescent lamp is largely determined by the phosphor coated on the inner surface of the tube. The color temperature of different fluorescent lamps varies widely, ranging from 2900K to 10000K. According to the color, it can be roughly divided into warm white (WW), white (W), cool white (CW), and daylight (D). Under normal circumstances, warm white (WW), white (W), daylight (D) fluorescent lamps have general color rendering properties, and cool white (CW), soft white and advanced warm white (WWX) fluorescent lamps can provide better color rendering , High-grade cool white (CWX) fluorescent lamps can have excellent color rendering. The light emitted by fluorescent lamps is relatively scattered and not easy to focus, so it is widely used in relatively soft lighting, image down-shooting, up-shooting flood lighting, working lighting, and soft accent lighting.
3. Sodium lamp
Also known as a high-pressure sodium lamp is a discharge lamp that emits light from sodium vapor. The luminous efficiency is extremely high, the life is long, the adaptability to the environment is good, and it can work normally under various temperature conditions.
Advantages and disadvantages of sodium lamp:
The specifications and size of the sodium lamp are large; the color difference is an uncomfortable yellow-white cold light; the color rendering is poor, and the color rendering index of ordinary high-pressure sodium lamps is only 23. Therefore, ordinary high-pressure sodium lamps are mostly used for road lighting, etc. for their luminous efficacy and life High requirements, but not high requirements for light color and color rendering. There is also an improved high-pressure sodium lamp with high color rendering, which has a warm white light color and a high color rendering index of over 80%. This kind of lamp can be used in the field of display lighting, and the energy saving effect is obvious.
4. Metal halide lamp
Also known as metal halide lamp is a kind of high-pressure gas discharge lamp. The basic structure is a transparent glass shell and a high temperature resistant quartz glass arc tube. Nitrogen or inert gas is flushed between the shell and the inner tube, and the inner tube is filled with Enter inert gases, mercury vapor and metal halides. The basic working principle of the metal halide lamp: After entering the working state, the vapor of the metal halide diffuses to the arc center, and is dispersed into metal atoms and halogen atoms under the action of high temperature. The metal atoms participate in the discharge to emit visible light. When the atoms diffuse to the outer tube wall area of the electric isolated tube, the two recombine into metal halides.
The advantages and disadvantages of metal halide lamps:
The biggest advantage of metal halide lamps is high luminous efficacy and long life. Due to the difference in the structure of the lamp body and the filled metal halide, the luminous efficacy, the color temperature of the light and the color rendering of the metal halide lamp vary greatly. Although poor metal halide lamps have high luminous efficacy, they have poor color rendering properties; good metal halide lamps emit light colors close to the white of natural light, with comfortable visual experience and better color rendering properties. The working characteristic of the metal halide lamp is that it cannot be lit immediately, and it takes about 5 minutes to heat up to reach full brightness output. After the power supply is interrupted, it takes 5-20 minutes to cool the bulb before restarting. The metal halide lamp is sensitive to the fluctuation of the power supply voltage. When the power supply voltage changes more than 10% up and down the rated value, it will cause the change of the light color. And different working positions will also affect the color of the light and the life of the lamp.
5. Ceramic metal halide lamp
The ceramic metal halide lamp is a metal halide lamp that uses translucent ceramic as the electric solitary tube. It is a relatively new high-quality lighting source that combines the ceramic technology of a quartz metal halide lamp and a sodium lamp, combining the advantages of the two.
Advantages and disadvantages of ceramic metal halide lamps:
Since the ceramic tube can withstand higher temperatures and is very stable in chemical properties, the ceramic metal halide lamp has higher luminous efficacy, long life, more stable light and color during the life, small size, excellent color rendering, and Ra>80 advantage. And the ceramic tube can filter out most of the ultraviolet radiation, reducing the fading of the object due to lighting. In view of these advantages, ceramic metal halide lamps are becoming an important light source in the design of demonstrating light effects.
6.LED
Also known as light-emitting diodes, or LEDs for short, is a new type of light source that directly converts electrical energy into visible light through semiconductor diodes, using the principle of electroluminescence. Electroluminescence refers to the phenomenon of emitting light due to the interaction of a suitable substance with an electric field.
Advantages and disadvantages of LED light-emitting diodes:
As a new type of semiconductor light source, compared with traditional light sources, light-emitting diodes have the following advantages: long life, luminous time up to 100,000 hours; short start-up time, response time is only tens of nanoseconds; firm structure, as a solid whole The solid structure can withstand strong oscillations and shocks; it has high luminous efficiency and low energy consumption, and is an energy-saving light source; the luminous body is close to a point light source, and the light source radiation model is simple, which is conducive to the design of the lamp; the luminous direction is very strong, not It is necessary to use a reflector to control the direction of light irradiation, which can be made into a thin lamp, which is suitable for occasions where there is not much installation space. It is generally believed that light-emitting diodes are the fourth generation of light sources after incandescent lamps, fluorescent lamps, and high-pressure discharge lamps. With the advancement of new materials and manufacturing processes, the performance of light-emitting diodes is increasing, and the scope of applications is getting wider and wider.
