A special optical track spotlight for reducing fruit ripening

Abstract

The application provides a special optical track spotlight for reducing fruit ripening, relates to the technical field of track spotlights, and comprises a spotlight rear shell, wherein an optical track is arranged on the spotlight rear shell, a spotlight front shell is arranged on the spotlight rear shell, an LED chip substrate is arranged in the spotlight front shell, an LED chip is arranged on the LED chip substrate, a composite fluorescent powder glue layer is coated on the LED chip, a second lens is arranged on one side of the composite fluorescent powder glue layer, LuAG:Ce green fluorescent powder and KSF narrow-band red fluorescent powder are mixed in the composite fluorescent powder glue layer, and the composite fluorescent powder glue layer does not contain nitride red fluorescent powder with an emission main peak located in a 655nm-665nm wave band, so that directional regulation of a light spectrum is completed at an encapsulation level of a light source, LuAG:Ce green powder emits a green spectrum with an emission main peak located in a 520nm-540nm wave band after being excited by blue light, the wave band can induce chlorophyll synthase activity and inhibit abscisic acid generation, and the process of fruit and vegetable aging is delayed from the perspective of plant physiology.

Description

Technical Field

[0001] This invention belongs to the field of track spotlight technology, and more specifically, relates to a special optical track spotlight that reduces the ripening of fruit. Background Technology

[0002] Track lighting is widely used for display lighting on fruit and vegetable shelves in supermarkets, fresh food markets, and fruit and vegetable retail stores. To attract customers' attention, these spotlights typically need to have high illuminance and a high color rendering index to reproduce the vibrant colors of fruits and vegetables. However, a dilemma often exists in practical applications: while high-intensity display lighting enhances the visual appeal of the products, it also accelerates the ripening and spoilage process of fruits and vegetables, leading to a significant reduction in shelf life and a substantial increase in store spoilage rates.

[0003] A special optical track spotlight designed to reduce fruit ripening has been found to have at least the following technical problems: Firstly, traditional track spotlights mostly use halogen lamps or ordinary LED light sources, which, while producing visible light, also emit a large amount of near-infrared heat radiation. This heat radiation directly shines on the surface of fruits and vegetables, raising the surface temperature by 3°C to 8°C compared to the ambient temperature. This temperature increase significantly accelerates the respiration of fruits and vegetables, with the respiration rate increasing by approximately 1.5 to 2 times for every 10°C increase. This leads to an uncontrolled rate of starch hydrolysis into soluble sugars, rapid degradation of organic acids and vitamin C, decreased fruit firmness, and ultimately, overripeness and rot.

[0004] Secondly, besides the thermal effect, the spectrum of ordinary LED light sources naturally contains a deep red light component with a peak around 660nm. Plant physiological studies have shown that light in this wavelength band can be preferentially absorbed by phytochromes in fruit and vegetable tissues, prompting the phytochromes to transform from a deactivated state (Pr) to an activated state (Pfr). The activated phytochromes, acting as signaling molecules, directly initiate the gene expression of ethylene synthase (ACC synthase), accelerating the release of ethylene, which is a well-known fruit ripening hormone. Therefore, even if a low-heat-generating LED light source is used, if the 660nm ripening peak is still present in the spectrum, the aging process of fruits and vegetables cannot be effectively curbed. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a special optical track spotlight that reduces the ripening of fruits, thus solving the problems described above.

[0006] A special optical track spotlight that reduces fruit ripening requires artificial ripening includes a rear housing with an optical track and a front housing. An LED chip substrate is located inside the front housing, and LED chips are mounted on the substrate. A composite phosphor layer is coated on the LED chips. A second lens is positioned on one side of the composite phosphor layer, and a reflector is positioned on one side of the second lens. The inner wall of the reflector is coated with a dichroic interference filter. A first lens is positioned on one side of the reflector, and a honeycomb anti-glare grid is positioned on one side of the first lens, thereby achieving photothermal separation and spectral control.

[0007] Preferably, the outer wall of the reflector cup is provided with a copper cavity, and a vacuum groove is opened inside the copper cavity. The vacuum groove is filled with pure water to achieve efficient phase change heat dissipation to eliminate local hot spots. The copper cavity is provided with heat dissipation fins, which are multiple parallel thin sheet structures to increase the heat exchange area and improve heat dissipation efficiency.

[0008] Preferably, the LED chip substrate is an aluminum nitride ceramic substrate to ensure high thermal conductivity for rapid heat conduction, and the LED chip is a flip-chip blue light chip with a peak excitation wavelength of 450nm to 455nm to reduce light shading and lower thermal resistance.

[0009] Preferably, the matrix of the composite phosphor adhesive layer is methyl phenyl silicone rubber, and the composite phosphor adhesive layer is mixed with LuAG:Ce green phosphor and KSF narrowband red phosphor to generate a green-preserving spectrum to delay the aging of fruits and vegetables and maintain a high color rendering index.

[0010] Preferably, the second lens is a convex-concave lens, with its convex surface facing the LED chip side and its concave surface facing the reflector side, used to converge the diverging light to reduce light loss. The material of the second lens is high borosilicate optical glass, with a light transmittance of not less than 92%, ensuring high light transmittance to improve light output efficiency.

[0011] Preferably, the dichroic interference filter film consists of 27 layers. The dielectric films are stacked alternately to achieve photothermal separation of high visible light reflectance and high infrared light transmittance.

[0012] Preferably, the first lens is a plano-convex lens or a freeform lens, with its planar side facing the reflector and its convex side facing the light-emitting direction, for secondary light distribution shaping to obtain a uniform light spot. The first lens is made of polymethyl methacrylate or optical-grade polycarbonate, with a light transmittance of not less than 90%, to ensure light output efficiency and reduce light loss.

[0013] Preferably, the honeycomb anti-glare grille is formed by stamping and stretching thin aluminum alloy sheet, and multiple hexagonal honeycomb through holes are opened on its surface. The ratio of the depth to the diameter of the honeycomb through holes is not less than 1.5, which is used to block stray light to prevent glare. The surface of the honeycomb anti-glare grille is covered with a black chrome selective absorption coating. The black chrome selective absorption coating has an absorption rate of not less than 95% in the visible light band, which is used to absorb stray light energy and suppress secondary infrared radiation to avoid lateral heating of the fruit.

[0014] Preferably, a control circuit board is provided inside the rear housing of the spotlight. The control circuit board integrates a 24GHz microwave radar sensing module and a PWM constant current drive module. The PWM constant current drive module is electrically connected to the LED chip substrate to realize intelligent control of full power display when people are present, low power energy saving when no people are present, and constant spectrum, which greatly reduces the amount of standby accumulated heat radiation.

[0015] Compared with the prior art, the present invention has the following beneficial effects: In this invention, a copper cavity is tightly fitted and fixed to the outer wall of the reflector. The copper cavity has a vacuum groove filled with pure water. The pure water is heated and rapidly evaporates and vaporizes in a vacuum environment. The water vapor carries latent heat and diffuses to the cold end, where it condenses and releases heat. The condensate flows back to the hot end by relying on the inclined cavity wall, forming a phase change cycle that does not require external power. The equivalent thermal conductivity of this phase change cycle can reach more than 5000 W / (m·K), which is more than ten times that of pure copper. It can evenly diffuse the local hot spots generated by the LED chip to the entire copper cavity in a very short time, ensuring that the temperature difference between different areas of the lamp body does not exceed 2°C. Combined with the convective heat exchange between the heat dissipation fins and the air, the surface temperature of the lamp body is maintained below 35°C, completely eliminating the baking effect of local high heat caused by traditional spotlights on nearby fruits. Moreover, this phase change heat dissipation structure is evenly distributed along the circumference of the reflector, without increasing the axial length of the lamp, resulting in a compact structure.

[0016] In this invention, the composite phosphor layer contains a mixture of LuAG:Ce green phosphor and KSF narrowband red phosphor, without any nitride red phosphor whose emission peak is located in the 655nm-665nm band. This allows for directional spectral modulation of the light source at the encapsulation level. The LuAG:Ce green phosphor, when excited by blue light, emits a green-preserving spectrum with its main emission peak in the 520nm-540nm band. This band can induce chlorophyll synthase activity and inhibit abscisic acid production, thus delaying the senescence process of fruits and vegetables from a plant physiological perspective. The KSF red phosphor precisely controls the red light emission peak... Locked at 630nm, it provides sufficient red stimulation to human cone cells to ensure the color rendering index. Furthermore, because its emission peak is completely deviated from the 660nm activation band of plant phytochromes, it will not trigger the conversion of phytochrome Pr to Pfr, thereby blocking the expression pathway of the ethylene synthase gene from the source. Thus, without the need for external filters or additional energy consumption, it can achieve active elimination of ripening spectrum and directional enhancement of greening spectrum simultaneously while ensuring a high color rendering index (Ra≥95) through the physical limitation of the phosphor formulation. It combines structural simplicity with functional effectiveness.

[0017] In this invention, a dichroic interference filter film is coated on the inner wall of the reflector cup, and this film consists of 27 layers. The dielectric films are stacked alternately, achieving a reflectivity of over 92% for the visible light band (380nm–780nm) and a transmittance of no less than 85% for the near-infrared thermal radiation band (780nm–2500nm). This achieves physical separation of visible light and infrared thermal radiation along their spatial propagation path. Unlike traditional filters that directly absorb infrared energy and generate heat, the interference film of this invention transmits infrared energy to the outer wall of the reflector cup, where it is actively dissipated by the subsequent heat dissipation structure. This ensures that the forward-shielded cold light carries almost no infrared thermal radiation without sacrificing visible light emission efficiency. The fruit surface temperature can be reduced by 4°C to 6°C compared to traditional spotlights, thus solving the problem of accelerated respiration rate and quality deterioration in fruits and vegetables caused by localized temperature rise at the source of thermal radiation.

[0018] In this invention, a honeycomb anti-glare grid is covered with a black chrome selective absorption coating. Combined with a depth-to-diameter ratio of no less than 1.5 for the honeycomb holes, the depth-to-diameter ratio constraint physically blocks stray light with an observation angle greater than 30° from the honeycomb hole walls. The black chrome coating has an absorption rate of no less than 95% in the visible light band and an emissivity of no more than 0.1 in the infrared band. It can absorb the residual stray light energy generated by multiple reflections and convert it into weak heat energy, which is conducted along the grid body to the outside of the lamp housing and dissipated, without radiating long-wave infrared heat. Thus, it not only eliminates glare pollution caused by stray light and improves the visual comfort of customers, but also avoids the lateral indirect heating of fruits caused by stray light being reflected twice and converted into infrared heat after hitting the metal edge of the shelf. This ensures that all effective emitted light is accurately projected onto the surface of the fruit without generating additional heat load. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the rear housing of the spotlight of the present invention; Figure 3 This is a schematic diagram of the structure of the front housing of the spotlight of the present invention; Figure 4 This is a schematic diagram of the structure of the heat-conducting ring of the present invention; Figure 5 This is a schematic diagram of the heat dissipation fins of the present invention; Figure 6 This is a schematic diagram of the structure of the LED chip substrate of the present invention; Figure 7 This is a schematic diagram of the reflector cup of the present invention; Figure 8 This is a schematic diagram of the honeycomb anti-glare grille of the present invention.

[0020] In the figure, the correspondence between the component names and the attached drawing numbers is as follows: 1. Spotlight front housing; 2. First lens; 3. Honeycomb anti-glare grille; 4. Heat-conducting ring; 5. Reflector cup; 6. Dichroic interference filter film; 7. Second lens; 8. LED chip substrate; 9. LED chip; 10. Composite phosphor adhesive layer; 11. Heat dissipation fins; 12. Copper cavity; 13. Vacuum groove; 14. Spotlight rear housing; 15. Optical track. Detailed Implementation

[0021] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but should not be used to limit the scope of the present invention. Please see Figure 1 - Figure 8 This invention provides a special optical track spotlight that reduces fruit ripening, including a front cover 1, a rear cover 14, and an optical track 15. The optical track 15 is fixedly installed on the top of the rear cover 14. The optical track 15 is used to engage with the mains rail to realize the power supply and mechanical suspension of the lamp. The left side of the rear cover 14 is screwed to the right side of the heat-conducting ring 4. The left side of the heat-conducting ring 4 is integrally formed with the front cover 1. The front cover 1 and the rear cover 14 together form a sealed lamp body cavity. The front cover 1 is a hollow cylindrical structure. Its inner cavity contains, along the axial direction, a first lens 2, a honeycomb anti-glare grid 3, a reflector 5, a second lens 7, an LED chip substrate 8, and an LED chip 9. All of the above components are coaxially arranged with the front cover 1.

[0022] Specifically, an LED chip substrate 8 is fixedly mounted on the right side of the inner side of the spotlight front housing 1 by bolts. The LED chip substrate 8 is an aluminum nitride ceramic substrate with a thermal conductivity of not less than 170 W / (m·K). It is used to support the LED chip 9 and conduct the heat generated by the chip downstream. Multiple blue LED chips 9 are uniformly arrayed on the left side surface of the LED chip substrate 8 by a die bonding process. The spacing between adjacent LED chips 9 is 1.5 mm to 2.5 mm to ensure uniform light output. In this embodiment, the LED chip 9 is a flip-chip blue light chip with a peak excitation wavelength of 450 nm to 455 nm. The flip-chip structure can eliminate the gold wire bonding process, reduce light shading and reduce thermal resistance.

[0023] It should be noted that the light-emitting surfaces and surrounding sidewalls of multiple LED chips 9 are completely covered with a composite phosphor adhesive layer 10. This composite phosphor adhesive layer 10 is applied to the left side surface of the LED chip substrate 8 through a dispensing process, and after baking and curing, it forms a hemispherical transparent film that encapsulates all the LED chips 9 inside. The matrix of the composite phosphor adhesive layer 10 is methylphenyl silicone rubber with a refractive index of 1.54, which matches the refractive index of the light-emitting surfaces of the LED chips 9, thus reducing light extraction loss caused by total internal reflection. Unlike conventional phosphor adhesive layers, the composite phosphor adhesive layer 10 in this embodiment uniformly mixes LuAG:Ce green phosphor and KS. The F narrowband red phosphor contains absolutely no nitride red phosphors with emission peaks in the 655nm–665nm band. The emission peak of the LuAG:Ce green phosphor is locked in the 520nm–540nm band, which is used to generate a green-preserving spectrum that antagonizes abscisic acid in plants. The emission peak of the KSF narrowband red phosphor is precisely locked in the 630nm±3nm band, which is used to supplement the lack of red light to ensure the color rendering index. At the same time, its emission peak is far away from the 660nm plant phytochrome activation band. Through the physical limitation of the above phosphor formulation, the radiant flux of the ripening-sensitive band is directly reduced at the light source packaging level, without the need for external filters.

[0024] Furthermore, a second lens 7 is disposed at a distance on the left side of the LED chip substrate 8. The second lens 7 is a convex-concave lens, with its convex surface facing the LED chip 9 and its concave surface facing the reflector cup 5. It is used to converge the diverging light emitted from the composite phosphor adhesive layer 10. The second lens 7 is made of high borosilicate optical glass with a light transmittance of not less than 92%, and its outer peripheral wall is fixed to the internal stepped surface of the spotlight front housing 1 by a pressure ring. The reflector cup 5 is disposed adjacent to the left side of the second lens 7. The reflector cup 5 is a rotating parabolic structure formed by spinning aluminum alloy, with its small end facing the LED chip 9 and its large end facing the light emission direction. The inner wall surface of the reflector cup 5 is coated with a dichroic interference filter film 6 by electron beam evaporation. The dichroic interference filter film 6 consists of 27 layers. The dielectric films are stacked alternately, and the optical thickness of each film is precisely controlled after calculation. This makes the reflectivity of the film layer greater than 92% in the visible light band of 380nm to 780nm, and has high transmission characteristics in the near-infrared thermal radiation band of 780nm to 2500nm, with a transmittance of not less than 85%. When the light emitted by the LED chip 9 is excited by the composite phosphor adhesive layer 10 and shines on the inner wall of the reflector cup 5, the visible light is efficiently reflected and shines forward, while the infrared thermal radiation generated is directly transmitted through the dichroic interference filter film 6 and the metal wall of the reflector cup 5 to the outer wall surface of the reflector cup 5, realizing the physical separation of the optical path and the thermal path.

[0025] Furthermore, multiple sets of copper cavities 12 are tightly fitted and fixed to the outer circumferential surface of the reflector cup 5. These copper cavities 12 are evenly distributed along the circumference of the reflector cup 5, with gaps between adjacent sets to form air convection channels. Each set of copper cavities 12 is a flat rectangular structure, made of oxygen-free copper and vacuum-brazed. A thermally conductive silicone grease layer is coated between its inner surface and the outer wall of the reflector cup 5 to eliminate contact thermal resistance. Each set of copper cavities 12 has a vacuum groove 13 inside, thereby allowing... To ensure the reflux of condensate in the vacuum tank 13, the vacuum tank 13 is a rectangular sealed chamber with a vacuum degree not exceeding 10⁻³Pa. The vacuum tank 13 is filled with high-purity pure water as a phase change working medium, and the filling amount of pure water is 20% to 30% of the volume of the vacuum tank 13. Heat dissipation fins 11 are integrally formed or welded to the side ends of each group of copper cavity bodies 12. The heat dissipation fins 11 are thin and multiple fins are arranged in parallel. The gap between adjacent fins is 3mm to 5mm, which is used to increase the heat exchange area with the outside air.

[0026] It should be noted that when the infrared heat penetrating the reflector 5 is conducted to the inner surface of the copper cavity 12, the liquid pure water at the bottom of the vacuum tank 13 is rapidly heated and evaporates. The water vapor, carrying the latent heat of vaporization, diffuses from the hot end to the cold end of the copper cavity 12 (i.e., the side near the heat-conducting ring 4). Upon contact with the cold end wall, it condenses into liquid water and releases heat. This released heat is dissipated to the outside of the lamp body via convection heat exchange with the surrounding air through the external heat-conducting ring 4. The condensed liquid water remains inside the vacuum tank 13. Because the copper cavity 12 is in use when the spotlight is operating... In a vertical or inclined state, the condensate can flow back to the hot end area along the vacuum tank 13, completing the phase change cycle of evaporation, condensation, and reflux. This cycle does not require external power and has an equivalent thermal conductivity of over 5000 W / (m·K), which is more than ten times that of pure copper. It can evenly diffuse the local hot spots generated by the LED chip 9 to the entire copper cavity 12 in a very short time, ensuring that the temperature distribution of each area on the lamp body is uniform and the temperature difference does not exceed 2℃, effectively avoiding the baking effect of local high temperature on nearby fruits.

[0027] Furthermore, a first lens 2 is fixedly installed on the left side of the large opening end of the reflector cup 5. This first lens 2 is a plano-convex lens or a freeform lens, with its planar side facing the reflector cup 5 and its convex side facing the light-emitting direction. It is used to perform secondary light distribution and shaping on the light reflected by the reflector cup 5, so that the uniformity of the light spot illuminating the shelf surface is not less than 0.8. The material of the first lens 2 is polymethyl methacrylate (PMMA) or optical grade polycarbonate (PC), and its light transmittance is not less than 90%. Its outer peripheral wall is pressed and fixed to the front end stepped surface of the inner cavity of the spotlight front housing 1 by a retaining ring. On the left side of the first lens 2, that is, at the light outlet at the front end of the spotlight front housing 1, a honeycomb anti-glare grid 3 is fixedly snapped. The honeycomb anti-glare grid 3 is formed by stamping and stretching a thin aluminum alloy plate. Multiple hexagonal honeycomb through holes are opened on its plate surface. The honeycomb holes are arranged in a honeycomb array, and adjacent... The honeycomb cells are connected by a common edge, and the ratio of the depth to the diameter of the honeycomb cells is not less than 1.5. For example, when the diameter is 10mm, the depth is not less than 15mm. This ensures that the light-emitting surface of the internal LED chip 9 is completely invisible when the angle between the observer's line of sight and the normal of the lamp surface is greater than 30°. This forces the light to be emitted along the effective irradiation direction and eliminates stray light obliquely shining towards the edge of the shelf. At the same time, the surface of the honeycomb anti-glare grid 3 is covered with a black chrome selective absorption coating by electroplating. The absorption rate of this coating in the visible light band is not less than 95%, while the emissivity in the infrared band is not higher than 0.1. This black chrome coating can absorb the residual stray light energy generated by multiple reflections, convert it into weak heat energy, and conduct it along the metal grid body to the outside of the lamp housing for dissipation. It will not radiate long-wave infrared heat to the outside, thereby avoiding the side heating of the fruit after the stray light is reflected twice by the edge of the shelf.

[0028] Furthermore, a control circuit board is fixedly installed in the internal cavity of the spotlight rear housing 14. This control circuit board integrates a 24GHz microwave radar sensing module and a high-frequency PWM constant current drive module. The antenna end of the microwave radar sensing module extends to the inner edge of the spotlight front housing 1, and is used to emit high-frequency electromagnetic waves and receive reflected echoes generated by human movement. It determines whether there are customers lingering in front of the shelf by using the Doppler frequency shift principle. The input end of the PWM constant current drive module is electrically connected to the power contact in the optical track 15 through a wire, and its output end is electrically connected to the power supply pad on the LED chip substrate 8 through a wire passing through the inner hole of the heat conduction ring 4, and is used to provide a constant drive current to the LED chip 9. The core of the PWM constant current drive module is a high-speed MOS switch, whose switching frequency is not less than 1kHz. The brightness is adjusted by adjusting the duty cycle of the switching time and turn-off time of the switch. During the adjustment process, the instantaneous current flowing through the LED chip 9 is always equal to the rated peak current, thereby ensuring that the peak emission wavelength of the LED chip 9 and the spectral ratio of the composite phosphor layer 10 do not drift at different brightness levels.

[0029] Specifically, when the microwave radar sensing module detects a human signal in front of the shelf, the PWM constant current drive module outputs a continuous current with a duty cycle of 100%, and the spotlight operates at full power, reaching the rated maximum illuminance to ensure the best display effect for customers. When the microwave radar sensing module does not detect a human signal for 30 consecutive seconds, the PWM constant current drive module automatically adjusts the duty cycle of the output current to 20%. At this time, the illuminance perceived by the human eye is reduced to about 20% of the full power, but the instantaneous current when the LED chip 9 is turned on is still equal to the rated peak current. Therefore, the spectral ratio remains unchanged, and the ripening inhibition function of the composite phosphor adhesive layer 10 remains effective. As the integral value of the effective current decreases to 20% of the full power, the total heat generation of the LED chip 9 decreases significantly with a square relationship. During the standby period, the accumulated heat radiation is only 4% to 5% of that under full power continuous operation, achieving a dynamic balance between display effect and anti-ripening heat control.

[0030] Furthermore, the first lens 2, the honeycomb anti-glare grid 3, the heat-conducting ring 4, the reflector 5, the dichroic interference filter film 6, the second lens 7, the LED chip substrate 8, the LED chip 9, the composite phosphor adhesive layer 10, the heat dissipation fins 11, the copper cavity 12, and the vacuum groove 13 are all housed in a sealed inner cavity formed by the front housing 1 and the rear housing 14 of the spotlight. The heat-conducting ring 4 is an annular metal part with an inner hole for wires to pass through and an external thread on its outer peripheral wall for detachable threaded connection with the front housing 1 and the rear housing 14 of the spotlight. At the same time, the heat-conducting ring 4 itself is made of aluminum alloy and serves as one of the auxiliary channels for heat conduction from the inside of the lamp body to the outside.

[0031] The workflow is as follows: In the first step, the mains power is introduced into the PWM constant current drive module via optical track 15. After high-frequency switching conversion, it provides a stable drive current to the LED chip 9. After the LED chip 9 is lit, electron-hole recombination radiation transition occurs in its PN junction region, emitting blue photons with a peak wavelength of 450nm to 455nm. These blue photons enter the composite phosphor adhesive layer 10 and excite the uniformly suspended LuAG:Ce green phosphor and KSF narrowband red phosphor, causing a photoluminescence down-conversion process. The excited LuAG:Ce green phosphor emits a broad-spectrum green light with a main peak located at 520nm to 540nm. This band of green light can... In terms of plant physiology, it can induce chlorophyll synthase activity and inhibit abscisic acid production, thereby delaying the senescence process of fruits and vegetables. When stimulated, KSF red powder emits narrow-band red light with its main peak precisely locked at 630nm. This narrow-band red light provides sufficient red stimulation to ensure the color rendering index. At the same time, because its emission peak is completely deviated from the 660nm plant phytochrome activation band, it will not trigger the expression of ethylene synthase gene. The remaining part of the blue light that is not absorbed is directly transmitted through the gel layer and mixed with the green and red light mentioned above to form a composite cool white light in the spectral power distribution, in which the 660nm ripening peak is significantly suppressed and the 520nm green retention peak and the 630nm color rendering peak are enhanced.

[0032] In the second step, after the composite cold white light is emitted from the composite phosphor layer 10, it passes through the second lens 7. The second lens 7 utilizes the converging effect of convex and concave lenses to gather the diverging light rays towards the optical axis, causing the light to strike the inner wall of the reflector cup 5 at a smaller incident angle, reducing the loss of light through multiple reflections within the cup. After entering the reflector cup 5, the light illuminates the surface of the dichroic interference filter film 6 coated on its inner wall. This dichroic interference filter film 6 is composed of multiple alternating stacked TiO2 / SiO2 dielectric films, and has a reflectivity of more than 92% for the visible light band of 380nm to 780nm. Therefore, the visible light portion of the composite cold white light... The light beam is efficiently reflected and converges towards the light outlet along the parabolic shape of the reflector cup 5. The visible light beam reflected by the reflector cup 5 enters the first lens 2. The first lens 2 performs secondary light distribution and shaping on the beam according to the freeform surface design, so that the illuminance of the light spot finally projected onto the shelf surface is uniform. The uniformized visible light beam passes through the honeycomb anti-glare grid 3. The hexagonal honeycomb through holes of the honeycomb anti-glare grid 3 have a depth-to-diameter ratio of not less than 1.5, so that stray light with an observation angle greater than 30° is blocked and absorbed by the honeycomb hole walls, and only the effective light is emitted and finally projected onto the fruit surface, providing display lighting with a high color rendering index and no ripening effect.

[0033] Thirdly, while the LED chip 9 emits light, its PN junction region generates a large amount of Joule heat due to non-radiative transitions. This heat is conducted from the LED chip 9 through the die-bonding layer to the aluminum nitride ceramic LED chip substrate 8, and then through the heat-conducting channel to the wall of the reflector cup 5. The near-infrared thermal radiation reaching the wall of the reflector cup 5 penetrates directly through the interference film layer and the metal wall of the reflector cup 5 to the outer surface because the dichroic interference filter film 6 has a transmittance of over 85% for wavelengths above 780nm. The outer wall of the reflector cup 5 is tightly fitted to the inner surface of the copper cavity 12, thus transferring heat... After being guided to the copper cavity 12, the liquid pure water at the bottom of the vacuum tank 13 inside it rapidly evaporates and vaporizes. The water vapor carries latent heat and diffuses from the hot end to the cold end under the pressure difference. It condenses into liquid water on the cold end wall and releases heat. The released heat is dissipated through the heat dissipation fins 11 by convection with the surrounding air. The condensed liquid water automatically flows back to the hot end under the capillary force of the micro-channel group, completing the phase change cycle of evaporation, condensation and reflux. This cycle does not require external power and can evenly diffuse local hot spots in a very short time, eliminating the baking effect on nearby fruits.

[0034] Fourthly, while the aforementioned optical and thermal paths continue to operate, the 24GHz microwave radar sensing module on the control circuit board maintains real-time monitoring. The microwave radar sensing module emits high-frequency electromagnetic waves towards the front of the shelf and receives the reflected echoes. Based on the Doppler effect, it determines whether there is a moving human signal. When a customer is detected lingering in front of the shelf, the microwave radar sensing module outputs an enable signal to the PWM constant current drive module. The PWM constant current drive module sets the duty cycle of the MOS switch to 100%, allowing the LED chip 9 to receive a continuous rated peak current. The spotlight operates at full power, outputting maximum illuminance to ensure the display effect. When the microwave radar sensing module does not detect a human signal for 30 consecutive seconds, it adjusts the duty cycle to 20%. In this state, the switch is fully turned on for 20% of the cycle time and for 80% of the cycle time... Completely shut off, but it is important to emphasize that the instantaneous current during conduction is still the rated peak current. Therefore, the peak emission wavelength of LED chip 9 and the spectral ratio of composite phosphor layer 10 are completely consistent with those at full power. The anti-ripening function remains effective in the low brightness standby state. At the same time, due to the significant decrease in current integral value, the total heat generation is reduced to about 20% of the full power, and the accumulated heat radiation is significantly reduced. In this embodiment, the ripening-sensitive band is eliminated from the source through the composite phosphor layer formula, photothermal separation is achieved through dichroic interference filter film, uniform heat diffusion and efficient heat dissipation are achieved through phase change cycle, and intelligent control is achieved through microwave radar and PWM dimming linkage to achieve full power display when there are people, low power energy saving when there are no people, and constant spectrum. Together, they achieve the comprehensive technical effect of fruit and vegetable display lighting with high color rendering, low heat radiation and anti-ripening induction.

[0035] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A special optical track spotlight for reducing fruit ripening, comprising a spotlight rear housing (14), wherein an optical track (15) is provided on the spotlight rear housing (14), characterized in that: The spotlight rear shell (14) is provided with a spotlight front shell (1), and an LED chip substrate (8) is provided inside the spotlight front shell (1). An LED chip (9) is provided on the LED chip substrate (8), and a composite phosphor adhesive layer (10) is coated on the LED chip (9). The front housing (1) of the spotlight is also provided with a reflector cup (5), and the outer wall of the reflector cup (5) is provided with a copper cavity (12). A vacuum groove (13) is opened inside the copper cavity (12), and the vacuum groove (13) is filled with pure water. A heat-conducting ring (4) is fixedly installed on the right side of the front housing (1) of the spotlight, and the heat-conducting ring (4) is fixedly connected to the copper cavity (12); A second lens (7) is provided on one side of the composite phosphor adhesive layer (10), a reflector (5) is provided on one side of the second lens (7), a first lens (2) is provided on one side of the reflector (5), and the inner wall of the reflector (5) is coated with a dichroic interference filter film (6). The composite phosphor adhesive layer (10) contains a mixture of LuAG:Ce green phosphor and KSF narrowband red phosphor, and does not contain nitride red phosphor with emission peak located in the 655nm~665nm band.

2. The special optical track spotlight for reducing fruit ripening as described in claim 1, characterized in that, A honeycomb anti-glare grid (3) is provided on one side of the first lens (2).

3. The special optical track spotlight for reducing fruit ripening as described in claim 2, characterized in that, The copper cavity (12) is provided with heat dissipation fins (11), which are multiple thin sheets arranged in parallel.

4. The special optical track spotlight for reducing fruit ripening as described in claim 3, characterized in that, The LED chip substrate (8) is an aluminum nitride ceramic substrate, and the LED chip (9) is a flip-chip blue light chip with a peak excitation wavelength of 450nm to 455nm.

5. The special optical track spotlight for reducing fruit ripening as described in claim 4, characterized in that, The matrix of the composite phosphor adhesive layer (10) is methyl phenyl silicone rubber, and the composite phosphor adhesive layer (10) contains LuAG:Ce green phosphor and KSF narrowband red phosphor.

6. The special optical track spotlight for reducing fruit ripening as described in claim 5, characterized in that, The second lens (7) is a convex-concave lens, with its convex surface facing the LED chip (9) and its concave surface facing the reflector (5). The material of the second lens (7) is high borosilicate optical glass, and its light transmittance is not less than 92%.

7. The special optical track spotlight for reducing fruit ripening as described in claim 6, characterized in that, The dichroic interference filter (6) consists of 27 layers. It is composed of alternating layers of dielectric films.

8. The special optical track spotlight for reducing fruit ripening as described in claim 7, characterized in that, The first lens (2) is a plano-convex lens or a freeform lens, with its planar side facing the reflector (5) and its convex side facing the light-emitting direction. The material of the first lens (2) is polymethyl methacrylate or optical grade polycarbonate, and its light transmittance is not less than 90%.

9. A special optical track spotlight for reducing fruit ripening as described in claim 8, characterized in that, The honeycomb anti-glare grille (3) is formed by stamping and stretching aluminum alloy sheet. Multiple hexagonal honeycomb through holes are opened on its surface. The ratio of the depth to the diameter of the honeycomb through holes is not less than 1.

5. The surface of the honeycomb anti-glare grille (3) is covered with a black chromium selective absorption coating. The absorption rate of the black chromium selective absorption coating in the visible light band is not less than 95%.

10. A special optical track spotlight for reducing fruit ripening as described in claim 9, characterized in that, The back cover (14) of the spotlight is equipped with a control circuit board, which integrates a 24GHz microwave radar sensing module and a PWM constant current drive module. The PWM constant current drive module is electrically connected to the LED chip substrate (8).

Images