71 results about "Color rendering index" patented technology

The invention relates to the technical field related to energy-saving illumination control, in particular to an energy-saving illumination method, system and equipment integrating tasks and human body perception, and the method comprises the steps: dividing task scenes, configuring reference illumination parameters, evaluating an illumination comfort index, dynamically adjusting output power and spectral distribution, and determining an adaptive perception interval. And setting an illumination adaptive switching mechanism, when task scene switching is detected, performing illumination parameter smooth transition in combination with the adaptive sensing interval, and generating a non-dominated sorting optimization strategy according to energy consumption feedback and illumination comfort index optimization control. The technical problems that energy-saving control depends on fixed threshold adjustment, excessive low illumination is caused by energy consumption reduction, and visual fatigue is aggravated are solved, task scene division and reference parameter configuration are achieved, fuzzy control is adopted to adjust output power and spectral distribution in real time, and the real-time adjustment of the output power and spectral distribution is achieved in an adaptive sensing interval. Energy consumption optimization is carried out on the premise that the color rendering index and the illumination are guaranteed, and the energy efficiency of the lighting system is improved.

The invention discloses a preparation method of a low-blue-light LED panel lamp, and belongs to the technical field of LED illumination. According to the method, through blue light chip screening, composite fluorescent powder system optimization, multi-layer optical structure design and heat dissipation coordinated regulation and control, the radiation power proportion of the blue light wave band (430-460 nm) is smaller than or equal to 5%, meanwhile, it is guaranteed that the color rendering index Ra is larger than or equal to 85, and the lighting effect is larger than or equal to 100 lm / W. The core innovation of the LED lamp is that the double-effect eye protection layer of quantum dot doped silica gel and cerium yttrium aluminum garnet composite fluorescent powder is adopted, and the optical matching design of the micro-nano texture light guide plate and the gradual change type diffusion film is combined, so that the technical problems that an existing low-blue-light LED lamp is low in lighting effect, poor in color rendering property, uneven in blue light filtering and the like are solved. The blue light hazard level of the prepared LED panel lamp reaches RG0 level, and the LED panel lamp is suitable for long-time close-range illumination scenes such as classrooms, offices and bedrooms and has wide application prospects.

The utility model provides a light source device and a lamp. A containing groove is formed in a support of the light source device. The first blue light chip is arranged on the groove bottom of the accommodating groove, and the first blue light chip is used for emitting blue light of which the peak wavelength is a; the second blue light chip is arranged on the groove bottom of the containing groove, the second blue light chip and the first blue light chip are arranged in a spaced mode, the second blue light chip is used for emitting blue light with the peak wavelength being b, and b is larger than a; the first fluorescent structure covers the first blue light chip; the second fluorescent structure covers the second blue light chip and the first fluorescent structure, and the second fluorescent structure comprises yellow-green fluorescent powder; according to the invention, a regional excitation structure can be formed, light of different colors can be excited in a targeted manner to complement spectrum deficiency, and the overall color rendering index can be improved; meanwhile, mutual absorption loss between different fluorescent structures is reduced through dual-wavelength hierarchical excitation and physical isolation of the fluorescent structures, and optimization of light extraction efficiency is facilitated.

The utility model discloses an LED light source structure comprising a substrate, the substrate is connected with a light emitting unit and a first light blocking ring surrounding the outer side of the light emitting unit, and the light emitting unit comprises a purple light LED wafer, a blue light LED wafer, an ultraviolet light LED wafer, a red light generating structure and an infrared light generating structure. The surface of the blue light LED wafer is provided with first fluorescent powder or first fluorescent conversion glue capable of converting part of blue light into yellow light, purple light, blue light, yellow light, ultraviolet light, red light and infrared light are integrated, the light source structure can generate wider spectral distribution, and the color quality and the color rendering index of light are improved. The lighting quality can be improved, and the requirements of specific application fields such as plant growth lamps, special lighting in medical equipment and the like can be met. Through the design of the multi-wavelength LED wafer combination, spectral components are controlled more accurately, so that the energy conversion efficiency is optimized, unnecessary energy loss is reduced, higher luminous efficiency is achieved, and meanwhile energy consumption is reduced.

A light emitting device includes a light emitting element having a light emission peak wavelength of 430 nm or more and 470 nm or less, and a fluorescent member containing a first fluorescent material having a light emission peak wavelength of 510 nm or more and less than 590 nm and a second fluorescent material having a light emission peak wavelength of 590 nm or more and 670 nm or less and containing a first fluoride fluorescent material having a composition included in the compositional formula represented by the following formula (1):where A1 includes K, M1 includes Si and Al, a and b satisfy 0<a<0.2 and 5<b<7, and c represents the absolute value of the charge of [M11-aMnaFb] ions.The light emitting device satisfies the following condition (A) or (B):the condition (A) is that an average color rendering index Ra is 80 or more and 90 or less and a color rendering index R9 is 50 or more and 90 or less; andthe condition (B) is that an average color rendering index Ra is 80 or more and 87 or less and a color rendering index R9 is 50 or more.

The utility model relates to the technical field of LED light sources, and discloses an LED light source capable of improving spectral continuity, which comprises a substrate, the substrate is provided with a light-emitting area, and the light-emitting area is provided with a plurality of short-wave blue light-emitting chips, a plurality of long-wave blue light-emitting chips and a plurality of red light-emitting chips; the light-emitting area is filled with a fluorescent glue layer; the fluorescent glue layer covers the plurality of short-wave blue light-emitting chips, the plurality of long-wave blue light-emitting chips and the plurality of red light-emitting chips; green fluorescent powder and red fluorescent powder are mixed in the fluorescent glue layer; in the process that light rays emitted by the short-wave blue light emitting chips, the long-wave blue light emitting chips and the red light emitting chips penetrate through the fluorescent glue layer, green fluorescent powder and red fluorescent powder are excited respectively, so that the emitted light rays are high in spectral continuity and have the advantages of being high in color temperature, low in blue light, high in color rendition degree and the like; the light emitted by the LED light source is closer to the solar spectrum, and the color rendering index is higher.

This invention discloses an LED spectral distribution optimization design method and an LED light source. The design method includes the following steps: S1, establishing a basis function library based on the Gaussian emission spectral function of phosphor materials; S2, defining the full spectral distribution function and optimization variables of the phosphor mixture; S3, constructing a comprehensive evaluation function and constraints based on color temperature, spectral efficacy, and color rendering index; S4, applying simulated annealing algorithm for optimization, aiming to minimize the comprehensive evaluation function, and globally optimizing the basis function weight vector w; S5, adjusting the comprehensive evaluation function and constraints and iteratively optimizing. This design method is applicable to the spectral control of white LEDs excited by multi-color phosphors, and can achieve synergistic optimization of color rendering index, color temperature accuracy, and luminous efficacy over a wide color temperature range, significantly improving the overall light quality and design efficiency of the LED light source.

The invention relates to the technical field of lighting lamps, in particular to a light generation method giving consideration to both color rendering and luminous efficiency, a light source comprises a high-efficiency LED and a high-color rendering LED, and the method comprises the following steps: acquiring a light source irradiation mode of the current light source; respectively matching a first illumination parameter of the high-efficiency LED and a second illumination parameter of the high-color-rendering LED according to the light source irradiation mode; first projection light projected by the high-efficiency LED is adjusted according to the first illumination parameter, second projection light projected by the high-color-rendering LED is adjusted according to the second illumination parameter, the first projection light and the second projection light are projected at the same time and form mixed light, and the CRI value and the luminous flux of the mixed light both meet the set requirements of the light source irradiation mode. The high-color-rendering LED can be matched with the high-efficiency LED with the power consumption originally small enough without full-power operation, light with the CRI value high enough is achieved in a light mixing mode, and therefore the problem that the power consumption is too large due to full-power operation of the high-color-rendering LED is solved, and the endurance of the whole light source is prolonged.

This utility model relates to the field of lighting display technology, and more particularly to a stage lighting system. The stage lighting system includes: a stage light and a driving structure; the stage light includes a light source, a reflector, a color temperature mixing component, and an imaging component; the driving structure is mechanically connected to the color temperature mixing component; the reflector, color temperature mixing component, and imaging component are arranged sequentially along the light path transmission direction of the light source; the color temperature mixing component includes a first filter, a second filter, a third filter, and a color temperature adjustment filter, which are arranged in a staggered manner along the light path transmission direction; two filter halves of each filter are arranged opposite each other on both sides of the light path transmission direction; two color temperature adjustment halves of the color temperature adjustment filter are also arranged opposite each other on both sides of the light path transmission direction. This utility model's technical solution can achieve a color rendering index (CRI) of over 70 for stage lights under low color temperature and low brightness conditions.

This invention belongs to the field of luminescent materials technology, specifically disclosing a metal halide luminescent material, its preparation method, and its application. It involves reacting cuprous halide and tetraethylammonium halide to synthesize crystals emitting blue, white, and yellow light, thus completing the (TEA)₂Cu₂X luminescent material. y The preparation of the crystal enabled tunable emission spectra within the visible light region, resulting in a single-component white light emission crystal (TEA)2Cu2Br2Cl2 with excellent color rendering index and ultra-wideband emission. This single-component white light crystal exhibits ultra-wideband emission characteristics, with a full width at half maximum (FWHM) of 300 nm and CIE coordinates of (0.32, 0.32), very close to the CIE coordinates of pure white light (0.33, 0.33). These characteristics make it an ideal choice for natural white LED applications, and when fabricated into white light emission devices, it achieves a color rendering index as high as 95. Furthermore, it contains no rare earth elements, making it an environmentally friendly material. Its preparation process is simple and low-cost, enabling large-scale industrial production.

The lighting device includes a respective plurality of first and second light emitting diodes (M-LEDs, N-LEDs) arranged on a carrier. Each M-LED comprises a die having a first surface region SA1, the first surface region SA1 having a maximum spatial range SE1 of at most 100 microns. The N-LEDs are arranged on the carrier, each N-LED comprising a die having a second surface region SA2, the second surface region SA2 having a maximum spatial range SE2 of at most 300 microns. The M-LED emits a first light LG1 having a first emission peak wavelength in ultraviolet light, violet light, and / or blue light. The N-LED emits second light LG2 having a second emission peak wavelength in green light and / or red light. The ratio defined by SA2 / SA1 is equal to or greater than 10. The device light is white light having a correlated color temperature (CCT) in the range of 2000-6500 K and a color rendering index of at least 80.

The utility model discloses a wavelength conversion assembly and lighting equipment. The wavelength conversion assembly comprises a supporting piece, a first wavelength conversion layer and a second wavelength conversion layer. Wherein the first wavelength conversion layer comprises a bearing part and a protruding part which are connected with each other; the bearing part is arranged on the supporting piece, and the side, away from the supporting piece, of the bearing part is provided with a first area and a second area, the protruding part is located in the first area and protrudes relative to the bearing part. The second wavelength conversion layer is wound on the periphery of the protruding part and covers the second area; wherein the second wavelength conversion layer comprises red fluorescent particles. The second wavelength conversion layer is doped with the red fluorescent particles, so that the specified laser can be converted into red fluorescence under the excitation of the red fluorescent particles. When the wavelength conversion assembly is configured in the lighting equipment, the lighting light generated by the lighting equipment can be mixed with the red light component, so that the color rendering index of the lighting light is improved, and the lighting equipment can meet the application scene with the high color rendering index.

This invention discloses a low color temperature LED light source, comprising: a packaging substrate; a yellow LED chip and a blue LED chip, fixed to the packaging substrate by a die-bonding layer; a silicone mixture coated on the blue LED chip; the silicone mixture is doped with red phosphor, the peak wavelength range of which is 600nm to 640nm; wherein, both the yellow and blue LED chips are gallium nitride-based LED chips, the peak wavelength range of which is 540nm to 590nm for the yellow LED chip and 440nm to 460nm for the blue LED chip; the color temperature of the low color temperature LED light source is 1600K-2500K, and the color rendering index Ra≥70. By coating the blue LED chip with a silicone mixture doped with red phosphor, a portion of the blue light is converted into red light, thereby mixing to form low color temperature white light. Simultaneously, using only red phosphor effectively avoids the sedimentation and uncontrolled ratio problems that occur when different colored phosphors are mixed and coated, ensuring the long-term stability of the light source's color temperature from a physical structure perspective.

The embodiment of the invention discloses a multiband LED epitaxial structure. A multi-quantum well light-emitting layer of the multiband LED epitaxial structure comprises a first blue light InGaN layer, a first green light InGaN layer, a first quantum barrier layer, a first energy band regulation and control layer, a second blue light InGaN layer, a second energy band regulation and control layer and a second quantum barrier layer which are sequentially, periodically and alternately grown in the epitaxial direction. The first energy band regulation and control layer comprises a first N-polarity GaN layer and a first AlGaN layer which are stacked in sequence, the first AlGaN layer is of a multi-layer structure, and the Al component content of the first AlGaN layer is gradually increased in sequence in the epitaxial direction; the second energy band regulation and control layer comprises a second N-polarity GaN layer and a second AlGaN layer which are sequentially stacked, the second AlGaN layer is of a multi-layer structure, and the Al component content of the second AlGaN layer is sequentially decreased in the epitaxial direction; wherein N-polarity heat treatment needs to be carried out in an NH3 atmosphere after the first N-polarity GaN layer is deposited and after the second N-polarity GaN layer is deposited. According to the invention, the damage of the LED white light source to eyes can be reduced, and the LED white light source has good color rendering index and high luminous efficiency.

The lighting device includes a respective plurality of first and second light emitting diodes (M-LEDs, N-LEDs) arranged on a carrier. The M-LED includes a die having a first surface region SA1, the first surface region SA1 having a maximum spatial range SE1 of up to (100) microns. The N-LED includes a die having a second surface region SA2, the second surface region SA2 having a maximum spatial range SE2 of at most (300) microns. The M-LED emits first light having a first emission peak in green light. The N-LED is configured to emit second light having a second emission peak in blue light, and is configured to emit third light having a third emission peak in red light. The ratio defined by SA2 / SA1 is equal to or greater than (10), and the device light is white light having a correlated color temperature in the range of 2000 K to 6500 K and a color rendering index of at least (80).

The invention relates to an ultraviolet-blue light filtering type conjugated organic chromophore as well as a preparation method and application thereof, the ultraviolet-blue light filtering type conjugated organic chromophore provided by the invention is prepared by taking benzothiadiazole as a core, fusing heterocyclic ring units on two sides and introducing an aldehyde group (CHO) substituent, can be dissolved in organic solvents such as chloroform and chlorobenzene, and has excellent film-forming property. The material has strong absorption in the wave band of 350-550 nm, the maximum absorption peak is at the position of 460 nm, and the blue light hazard wave band can be accurately covered. When the material is applied to a semitransparent organic solar cell, the color rendering index (CRI) reaches 92 or above, and the material is responsive to 300-400 nm near ultraviolet light. The material can be widely applied to photoelectron protection materials, display device coatings and eye protection products, and the problems that an existing material excessively absorbs red light and is low in CRI are solved.

The invention discloses a high-color-rendering-index white light device and a preparation method and application thereof, yellow YAG and wide-band red and green nitride fluorescent powder improve the color rendering index of an LED, a flexible polymer is used as a packaging material, and the high-color-rendering-index white light LED device applied to a lighting source is prepared; red fluorescent powder and green fluorescent powder are added on the basis of yellow fluorescent powder, and a white light LED device with the color rendering index of 96.9 is obtained. The color rendering index is high, meanwhile, the mass ratio of the 6901A silica gel to the 6901B silica gel is adjusted, the fluorescent powder is packaged, and the flexible fluorescent powder composite light-emitting film with the maximum deformation displacement and the optimal fracture stress is obtained and used for device preparation. The color rendering index of the device can be effectively improved, and the adopted packaging film can still show excellent mechanical properties when subjected to stretching and cyclic physical deformation. Wide application prospects are realized in the fields of high-performance white light LED lighting devices, wearable equipment and flexible display.

The present invention relates to a light emitting diode, LED, filament (100) configured to, in an on-state of the LED filament, emit LED filament light. The LED filament (100) comprises an elongated carrier (101) comprising a first major surface (101´) and a second major surface (101´´) opposite to the first major surface (101´), and an array of a plurality of LEDs (102) arranged on the first major surface of the elongated carrier (101), wherein each LED (102) of the plurality of LEDs is configured to, in the on-state, emit LED light. The LED filament (100) further comprises a first elongated encapsulant (104) at least partly enclosing the plurality of LEDs and at least partly covering the first major surface (101´), the first elongated encapsulant (104) comprising a first luminescent material comprising first green-yellow luminescent particles (104´) and configured to convert at least part of the LED light into first green-yellow converted light, and a second elongated encapsulant (105) enclosing the first elongated encapsulant (104), the second elongated encapsulant (105) comprising a second luminescent material configured to, in the on-state, at least partly convert the LED light and / or part of the first green-yellow converted light into a second orange-red converted light, wherein the second luminescent material comprises first orange-red luminescent particles (105´), and wherein the second elongated encapsulant further comprises first white pigment particles (105´´). The LED filament light at least comprises the first green-yellow converted light and the second orange-red converted light. The LED filament light is white light having a correlated color temperature in a range from 1700K to 6500K and a color rendering index of at least 70. The second elongated encapsulant (105) has, in an off-state of the LED filament, a terracotta appearance.

The light-emitting device provided by the embodiment of the invention comprises a blue light unit used for emitting blue light; the chromaticity coordinates B (xB, yB) of the blue light units meet the following conditions: 0.1 < = xB < = 0.2, and 0 < = yB < = 0.1; the green light unit is used for emitting green light; the color coordinate G (xG, yG) of the green light unit satisfies the following conditions: 0.1 < = xG < = 0.2, and 0.65 < = yG < = 0.75; the red light unit is used for emitting red light; the chromaticity coordinates of the red light unit, such as R (xR, yR), meet the following conditions: 0.63 < = xR < = 0.7, 0.3 < = yR < = 0.35; the warm white light unit is used for emitting warm white light, and the color coordinates W (xW, yW) of the warm white light unit meet the following conditions: 0.4 < = xW < = 0.5, 0.4 < = yW < = 0.5; the color coordinate W (xW, yW) of the warm white light unit is positioned above the Planck track; the chromaticity coordinates of the warm white light unit and the chromaticity coordinates of the red light unit are located on the two sides of the Planck track respectively; and the blue light unit, the green light unit, the red light unit and the warm white light unit can be matched to emit mixed white light which is close to black body radiation rays in a color temperature adjusting interval of 1800K-6500K. The mixed white light with various color temperatures emitted by the light-emitting device has a good color rendering index.

The utility model discloses an LED full-spectrum light source which comprises a substrate, the substrate is provided with a light-emitting unit composed of a plurality of LED wafers, and the LED wafers comprise an ultraviolet light LED wafer, a purple light LED wafer, a blue light LED wafer, a green light LED wafer, a yellow light LED wafer, a red light LED wafer and an infrared light LED wafer. Positive and negative pins for connecting the light-emitting units with a power supply are also arranged on the substrate; the light source can generate an almost continuous spectrum. This means that the LED lamp can be closer to natural sunlight, provides a more real lighting effect, and can also meet the lighting effect for applications requiring high-quality lighting, such as museums, galleries, photography and medical fields. The full-spectrum light source generally has a higher color rendering index CRI, and the real color of the object can be accurately reproduced. This is very advantageous for commercial displays, artwork displays, and any scenarios that have strict requirements for color accuracy.

The embodiment of the present application discloses a display panel, which comprises a first electrode layer, a light-emitting structure and a second electrode layer. The light-emitting structure comprises a first light-emitting unit, a second light-emitting unit and a third light-emitting unit which are sequentially stacked, the first light-emitting unit, the second light-emitting unit and the third light-emitting unit are independently selected from red light-emitting units, green light-emitting units and blue light-emitting units, and the light-emitting colors of the first light-emitting unit, the second light-emitting unit and the third light-emitting unit are different from each other. The light-emitting structure is provided with a light conversion layer, the light conversion layer is arranged on the side of the green light-emitting unit and / or the blue light-emitting unit close to the light-emitting surface of the light-emitting structure, and the light conversion layer is doped with red photoluminescence particles. In the present application, the light conversion layer is arranged in the light-emitting structure, the color rendering index of the white light display panel is improved, and the performance of the white light display panel is improved.

The light-emitting device provided by the embodiment of the invention comprises an RGB light-emitting assembly and a warm white light unit, the RGB light-emitting assembly comprises a blue light unit for emitting blue light, a green light unit for emitting green light and a red light unit for emitting red light; a color gamut of colors capable of being modulated by the light-emitting device is defined by the RGB light-emitting assemblies, and the color gamut meets NTSCgt; 105%; the warm white light unit is used for emitting warm white light, and the dominant wavelength of the warm white light is 570-600 nm; the blue light unit, the green light unit, the red light unit and the warm white light unit can be matched to emit mixed white light and are used for adjusting the color temperature of the mixed white light. According to the light-emitting device, through the combination of the RGB light-emitting assembly with the specific color gamut and the specific warm white light unit, the color light dimming effect and the white light mixing effect close to black-body radiation rays can be considered, and the color rendering index is high.

The application relates to the field of photoelectric technology, and discloses a full-spectrum LED epitaxial wafer, a preparation method thereof and an LED chip. The epitaxial wafer comprises a substrate, a buffer layer, an N-type GaN layer, a multi-spectrum light emitting well layer and a P-type GaN layer arranged on the substrate in sequence; the multi-spectrum light emitting well layer comprises a first light emitting well layer, a second light emitting well layer and a third light emitting well layer stacked in sequence; the first light emitting well layer comprises a plurality of groups of In x Ga (1‑x) N quantum well layers, Al a Ga (1‑a) N interface layers and first GaN quantum barrier layers stacked in sequence; the second light emitting well layer comprises a plurality of groups of In y Ga (1‑y) N quantum well layers, Al b Ga (1‑b) N interface layers and second GaN quantum barrier layers stacked in sequence; and the third light emitting well layer comprises a plurality of groups of In z Ga (1‑z) N quantum well layers, Al c Ga (1‑c) N interface layers and third GaN quantum barrier layers stacked in sequence. The full-spectrum LED epitaxial wafer can improve the light emitting efficiency and color rendering index of a full-spectrum chip.

The invention belongs to the field of solid luminescent materials, and particularly relates to a composite fluorescent ceramic material and a preparation method and application thereof.The composite fluorescent ceramic material comprises a fluorescent ceramic substrate and a fluorescent ceramic film, and the fluorescent ceramic film is arranged on at least one surface of the fluorescent ceramic substrate; the number of the fluorescent ceramic film is one or more. The thin film type composite fluorescent ceramic material has great advantages in the aspects of preparation cost, large-scale production and light-emitting wave band, can maintain excellent thermal conductivity, uniformity and substrate bonding performance, and improves the high temperature resistance and service capability of the LED fluorescent material; meanwhile, the color rendering index of the prepared composite fluorescent ceramic material is greater than 85 under the excitation of blue light at room temperature, and the highest color rendering index can reach 91.3.

To provide LED light-emitting devices and lighting fixtures with excellent color rendering at high color temperatures. [Solution] A light-emitting device comprising one or more LED elements and multiple phosphors, wherein the extracted light from the light-emitting device has a color temperature of 8400 to 10000K, an average color rendering index Ra of 95 or higher, and a special color rendering index R9 of 88 or higher. Furthermore, the extracted light from the light-emitting device has chromaticity coordinates of 0.27 to 0.29 and 0.30 to 0.32 in the chromaticity diagram of the CIE1931 color system.

The application belongs to the technical field of fluorescent pigments, and particularly discloses a yellow composite fluorescent pigment for improving luminous intensity and a preparation method thereof, which comprises the following steps: preparing yellow fluorescent powder: taking Y2O3, Al(NO3)3.9H2O and Ce(NO3)3.6H2O, BaF2 and NH4F, and sintering; preparing blue fluorescent powder: taking BaMgAl 10 O 17 ∶Eu 2+ taking raw materials, adding BaF2 and NH4F, and sintering; preparing film raw materials; compounding and curing: mixing the yellow fluorescent powder and the blue fluorescent powder at a mass ratio of 1:0.5-2, adding the mixed fluorescent powder into the film raw materials, and performing high-temperature solid-phase treatment. The yellow composite fluorescent pigment for improving luminous intensity and the preparation method thereof can overcome the problems of low color temperature and low color rendering index of the traditional yellow fluorescent powder, improve the luminous intensity of the yellow fluorescent powder, and expand the spectral response range of the yellow fluorescent powder.

The application belongs to the field of semiconductor display, and specifically provides a full-color LED micro display array structure, a preparation method and a full-color LED micro display, which comprises a vertical stack of red, green and blue three-primary-color LED pixel groups, each pixel comprising, from bottom to top, a substrate, a first light-emitting unit, a second light-emitting unit, a third light-emitting unit, a metal reflecting layer and a third electrode arranged above the third light-emitting unit, a SiO2 insulating layer arranged above the metal reflecting layer, a first electrode arranged above the SiO2 insulating layer and connected to the first light-emitting unit, a second electrode arranged above the SiO2 insulating layer and connected to the second light-emitting unit, and a fourth electrode arranged above the SiO2 insulating layer and connected to the first light-emitting unit, the second light-emitting unit and the third light-emitting unit, and red light, green light and blue light are emitted from the substrate side. Not only the light-emitting efficiency of blue light and green light LEDs is improved, but also the light down-conversion process is avoided, thereby improving the color rendering index of the vertical stack LED.

The invention provides a light generating system comprising a first light generating device, a second light generating device, a first luminescent material, and a control system, wherein: (A) the first light generating device comprises a first laser light source and is configured to generate first device light (111) having a first device light peak wavelength (λ1) and having a first spectral power distribution; wherein the first device light peak wavelength (λ1) is selected from the wavelength range of 425-465 nm; (B) the second light generating device comprises a second laser light source and is configured to generate second device light (121) having a second device light peak wavelength (λ2) and having a second spectral power distribution, different from the first spectral power distribution; wherein the second device light peak wavelength (λ2) is selected from the range of 470-490 nm; (C) the first luminescent material is configured in a light receiving relationship with the first light generating device and is configured to convert at least part of the first device light into first luminescent material light having a luminescent material emission centroid wavelength (λc,1) within the green-yellow wavelength range; and the first luminescent material is not configured in a light receiving relationship with the second light generating device; (D) the light generating system is configured to generate system light (1001) comprising one or more of the first device light, the second device light, and the first luminescent material light, wherein the system light has a controllable correlated color temperature; and (E) the control system is configured to control the first light generating device and the second light generating device, such that (a) in a first operational mode of the light generating system the system light has a first correlated color temperature CCT1, wherein CCT1≥4000 K, (b) in a second operational mode of the light generating system the system light has a second correlated color temperature (CCT2), wherein CCT2−CCT1≥1000 K, (c) in at least one of the operational modes, the system light has a correlated color temperature selected from the range of at least 7000 K, and (d) the system light in both operational modes has a color rendering index of at least 70.

The application discloses a method and device for improving color rendering index of an LED display screen, and the method comprises the following steps: adding a first white light sub-pixel W1 and a second white light sub-pixel W2 in an RGB display unit of the LED display screen to form an RGBW1W2 screen; obtaining the luminance characteristics of each sub-pixel in the RGBW1W2 screen, and constructing a characteristic conversion matrix of the RGBW1W2 screen according to the luminance characteristics; obtaining the output signals of each sub-pixel in the RGBW1W2 screen according to a to-be-transmitted rgb signal and the characteristic conversion matrix of the RGBW1W2 screen; and adjusting the output proportion of the first white light sub-pixel W1 and the second white light sub-pixel W2 to realize color temperature adjustment. The W1 and W2 are added in the RGB display screen, the color temperature of the screen can be accurately adjusted, and the high color rendering index can be maintained. Meanwhile, the method can ensure the color temperature of the screen.

This invention discloses a trapezoidal composite fluorescent glass-ceramic for laser illumination and its preparation method. The composite fluorescent glass-ceramic comprises a trapezoidal fluorescent glass and a high thermal conductivity ceramic coating on the outer layer of the fluorescent glass. The trapezoidal fluorescent glass is formed by melting and casting waste glass doped with luminescent ceramic powder, red phosphor, and high thermal conductivity powder. The composite glass-ceramic prepared by this invention achieves high-brightness white light emission under excitation by a 460nm blue LD chip, with a color rendering index of 82-91, and can withstand an excitation power density of 40W / mm². 2 ~55W / mm 2 Its luminous efficacy is 206–265 lm / W, and its thermal conductivity at room temperature is 18–29 Wm. ‑1 k ‑1 .