11.1 New Light Environment Technology
231
LED light distribution includes primary optical design and secondary optical
design. Among them, the primary optical design is completed in the packaging
process, which mainly determines the light output, the luminous flux size, the light
intensity, and the light intensity distribution of the light emitting device. The primary
light distribution design is to ensure the light output quality of each LED. It is
considered to extract as much light as possible from the LED chip. Due to the small
area of the LED chip, the large luminous flux, and the light-emitting characteristics
of the half-space light, the use of the LED chip for direct illumination application
has the problem of unreasonable use of light energy, thereby reducing the energy
utilization efficiency of the LED lamp. Therefore, the secondary light distribution
of the lighting fixture becomes a conventional scheme for improving the optical
performance of the LED light source and improving the energy utilization rate.
Secondary light distribution design mainly considers luminous flux, light intensity,
illuminance, illuminating angle and brightness, which are the research scope of nonimaging optics.
The purpose of LED thermal management technology is to derive and dissipate the heat generated by the LED device. Heat-dissipating materials should have
high thermal conductivity, such as new plastics, ceramics, graphite, metal, thermal
conductive adhesives, heat-dissipating coatings, etc. The development and design of
new luminaire structures with efficient heat dissipation is a key factor in reducing
the thermal resistance of LED lamps. In addition to developing high-performance
heat-dissipating materials and improving the heat dissipation performance of materials, LED lamp heat dissipation technology can also be divided into passive heat
dissipation and active heat dissipation according to the heat exchange mode with
ambient environment. Passive heat dissipation refers to the self-dissipation of heat
in an air environment without the need for additional ancillary facilities. Traditional
passive heat dissipation includes natural convection heat dissipation, uniform temperature plate heat dissipation, heat pipe and loop heat pipe heat dissipation, etc. The
new type has micro channel heat dissipation substrate and the use of new thermal
conductive materials. Active cooling of LED lighting refers to the consumption of
a certain amount of electric energy, using a fan, a pump, etc. to drive the heatdissipating medium to be forced to flow through the LED lighting device or to cool
the LED light source by means of semiconductor cooling, and bring the heat to the
heat-dissipating module. Compared with passive heat dissipation technique, active
cooling technology has the advantages of high cooling strength and good cooling
effect. It is especially suitable for high-power density or ultra-large LED lighting
devices. It mainly includes fan-type, water-cooled, thermoelectric cooling, ion wind
cooling and synthetic jet.
The main function of the LED driver is to convert ac voltage into dc voltage
and simultaneously match the LED voltage and current. LED drive technology has
the following features: DC control, high efficiency, pulse-width-modulation (PWM)
dimming, overvoltage protection, load disconnection, compact size and ease of use.
LED drive power is not only simple control and drive, but also has strict requirements
on energy efficiency, life, power factor, constant current accuracy, electromagnetic
compatibility, etc. Its development has been generally driven by industrial power
231
LED light distribution includes primary optical design and secondary optical
design. Among them, the primary optical design is completed in the packaging
process, which mainly determines the light output, the luminous flux size, the light
intensity, and the light intensity distribution of the light emitting device. The primary
light distribution design is to ensure the light output quality of each LED. It is
considered to extract as much light as possible from the LED chip. Due to the small
area of the LED chip, the large luminous flux, and the light-emitting characteristics
of the half-space light, the use of the LED chip for direct illumination application
has the problem of unreasonable use of light energy, thereby reducing the energy
utilization efficiency of the LED lamp. Therefore, the secondary light distribution
of the lighting fixture becomes a conventional scheme for improving the optical
performance of the LED light source and improving the energy utilization rate.
Secondary light distribution design mainly considers luminous flux, light intensity,
illuminance, illuminating angle and brightness, which are the research scope of nonimaging optics.
The purpose of LED thermal management technology is to derive and dissipate the heat generated by the LED device. Heat-dissipating materials should have
high thermal conductivity, such as new plastics, ceramics, graphite, metal, thermal
conductive adhesives, heat-dissipating coatings, etc. The development and design of
new luminaire structures with efficient heat dissipation is a key factor in reducing
the thermal resistance of LED lamps. In addition to developing high-performance
heat-dissipating materials and improving the heat dissipation performance of materials, LED lamp heat dissipation technology can also be divided into passive heat
dissipation and active heat dissipation according to the heat exchange mode with
ambient environment. Passive heat dissipation refers to the self-dissipation of heat
in an air environment without the need for additional ancillary facilities. Traditional
passive heat dissipation includes natural convection heat dissipation, uniform temperature plate heat dissipation, heat pipe and loop heat pipe heat dissipation, etc. The
new type has micro channel heat dissipation substrate and the use of new thermal
conductive materials. Active cooling of LED lighting refers to the consumption of
a certain amount of electric energy, using a fan, a pump, etc. to drive the heatdissipating medium to be forced to flow through the LED lighting device or to cool
the LED light source by means of semiconductor cooling, and bring the heat to the
heat-dissipating module. Compared with passive heat dissipation technique, active
cooling technology has the advantages of high cooling strength and good cooling
effect. It is especially suitable for high-power density or ultra-large LED lighting
devices. It mainly includes fan-type, water-cooled, thermoelectric cooling, ion wind
cooling and synthetic jet.
The main function of the LED driver is to convert ac voltage into dc voltage
and simultaneously match the LED voltage and current. LED drive technology has
the following features: DC control, high efficiency, pulse-width-modulation (PWM)
dimming, overvoltage protection, load disconnection, compact size and ease of use.
LED drive power is not only simple control and drive, but also has strict requirements
on energy efficiency, life, power factor, constant current accuracy, electromagnetic
compatibility, etc. Its development has been generally driven by industrial power