Photobiomodulation (PBM) in general lighting

Abstract

The present invention provides an illumination device for providing visible light and radiation in another spectrum of medical benefit. The illumination device comprises: a light source, the light source is suitable for emitting visible light; a radiation source, the radiation source is suitable for emitting radiation in a predetermined spectrum; and a driver circuit, the driver circuit is suitable for providing a first drive current, the first drive current is pulsed and has a duty cycle of not more than 20%. The predetermined spectrum is preferably in the range of 760-1400nm. The illumination device is suitable for providing the first drive current to the radiation source instead of to the light source. Corresponding methods and products using such an illumination device are also provided.

Description

Technical Field

[0001] The present invention relates generally to lighting, and more particularly to lighting devices, lighting systems, and methods for providing lighting devices that produce radiation in the non-visible spectrum sufficient to induce a photobiomodulation (PBM) response. Background Art

[0002] Photobiomodulation (PBM) refers to irradiating a living organism with a specific energy / power level to induce a biological or biochemical response. The irradiation can be in the visible spectrum, such as red light, or in the non-visible spectrum, such as infrared (IR). There has been a great deal of research on the medical benefits of using PBM therapy to treat physiological and psychological symptoms.

[0003] However, most of the equipment for administering PBM radiation is specialized equipment that is available in only a very limited number of medical facilities. Furthermore, these specialized equipment are often so complex that only a team of highly trained doctors, nurses, and technicians can use them. These factors have greatly limited the spread of the medical benefits of PBM within the general public.

[0004] Therefore, there is a need to overcome the above-mentioned shortcomings of currently available devices and methods. Summary of the invention

[0005] It would be desirable to provide a device that is easy to use, energy efficient, cost effective, and emits an amount of radiation sufficient to induce a PBM response.

[0006] According to a first aspect of the present disclosure, a lighting device is provided. The lighting device may include a light source, a radiation source, and a driver circuit. The light source may be suitable for emitting visible light. In one embodiment, the light source is capable of or suitable for emitting visible light having a color point in the CIE XYZ color space, the color point being less than 10 standard deviations of color matching (SDCM) from the black body line in the color space. The radiation source may be suitable for emitting radiation in a predetermined spectrum. In one embodiment, the predetermined spectrum may be within the infrared band or within the range of about 760-1400nm. The predetermined spectrum may include an invisible spectrum. The driver circuit may be suitable for providing a first drive current. The first drive current may be pulsed and may have a duty cycle of not more than 20%. The lighting device may be suitable for providing the first drive current to the radiation source rather than to the light source.

[0007] Conventional light sources already emit some radiation in the wavelength band that can induce a PBM response in humans. For example, the emission spectrum of a common incandescent light bulb includes small amounts of red and near infrared light, two wavelength bands associated with the ability to induce a PBM response.

[0008] However, medical studies have shown that radiation needs to reach a certain minimum amount of power density (measured in optical power per unit area) and dose (measured in energy per unit area) within the PBM-inducing light spectrum before it can induce a PBM response in a subject.

[0009] It should be noted that the meaning of the word "light" in the present disclosure is not limited to visible light. The word "light" in the present disclosure may include electromagnetic radiation outside the visible light spectrum. Likewise, it should also be noted that terms such as "optical power" are not limited to the power of visible light.

[0010] The inventors note a surprising effect discovered from an analysis of research literature in the field of PBM: light-induced biological or biochemical reactions may vary depending on power density, even though the same energy density or dose (energy per unit area) is delivered. In other words, simply targeting the product of power and time (and power density and time) may not be enough; the appropriate combination of power (density) and time is important. Sufficient power density is required to induce a PBM response even for short periods. Extending irradiation over time at a power density below the threshold to obtain the same amount of energy may not induce a PBM response or at most induce a limited PBM response. That is, insufficient power density is unlikely to be remedied by extending the irradiation time.

[0011] The inventors have recognized a problem in that driving a conventional light source, such as an incandescent light bulb, at a level that would provide sufficient power density in the PBM-induced light spectrum at a particular distance would require excessive electrical power. This problem arises at least from the fact that incandescent light bulbs are typically always on. Driving an incandescent light bulb to provide sufficient power density in the PBM-induced light spectrum would consume at least an order of magnitude more electrical power than is currently expected for sources used for general lighting.

[0012] The inventors have recognized that recent advances in other light sources, such as solid-state lighting (SSL) technology, can complement the shortcomings of incandescent bulbs. Taking light-emitting diodes (LEDs) as an example, lighting devices from SSL Technologies have lower thermal radiation and narrower emission bands, which help improve energy efficiency. SSL devices also allow for more precise control of the emission band, thereby achieving efficient power allocation in the desired emission band. More importantly, SSL devices are able to respond quickly to drive and / or control signals. In other words, compared with other types of light sources, such as incandescent lamps or halogen bulbs, which have thermal inertia as thermal emitters, the timing control of SSL devices is much more precise. In other words, SSL devices allow for almost instantaneous response to control and / or drive signals with negligible delay, making them suitable for fast pulsing.

[0013] However, the inventors have also recognized that current SSL devices alone are still unable to deliver the necessary amount of power density and dose within the PBM induction band. For example, assume a T8 or T5 type linear lamp with a length of 150 cm and equipped with LED devices as a replacement for fluorescent tubes has a uniform light distribution within 180°. At a distance r = 2m from the lamp, the surface area of ​​a theoretical half cylinder (which represents the theoretical light distribution at a distance of 2m) is A = πrh = ~10m 2 Assuming that the linear lamp is equipped with LED devices that emit substantially constant radiation over time at a total output power of 1 W in the desired light spectrum, the average power density at an average distance of 2 m from the lamp is approximately 10 μW / cm 2 (0.1W / m 2 ), which is higher than the minimum power density required (e.g. 1-50 mW / cm 2 It should be noted that because the difference is of orders of magnitude, it may be impractical, and most likely economically unacceptable, to maintain an LED device emitting substantially constant radiation over time and increase the total emitted watts by a corresponding order of magnitude.

[0014] The inventors have recognized another possibility for achieving a desired amount of power density within the physical capabilities of current SSL devices. By driving an SSL device (such as an LED) with a pulse rather than a continuous wave (which may be abbreviated as "CW" and implies non-pulsed) or near-continuous wave signal, the peak power emitted by the SSL device can be increased by a factor of the inverse of the pulse duty cycle while consuming the same amount of electrical power. In other words, an SSL device with pulsed emission has a higher peak emission power than the same device with continuous wave (CW) emission. In other words, the inventors have recognized the ability of pulsing to efficiently utilize limited electrical power in order to emit radiation with a desired amount of power (short term). In other words, the inventors have recognized that while narrowband transmitting devices such as SSL devices allow a limited amount of power to be concentrated into only a desired spectrum, pulsing such narrowband transmitting devices further allows the available power to be concentrated into short durations to enable such devices to emit radiation that passes an increased power threshold. Another advantage of pulsing is that the transmitting device can be cooled between pulses. This can ease the thermal budget of the emission device and can allow, for example, smaller driver circuits and the use of smaller and cheaper SSL devices (i.e., with less epitaxial material and / or smaller die surface). Cost savings can come from using smaller and cheaper SSL devices and / or using a smaller number of SSL devices in a lighting device that provides a fixed amount of PBM induced radiation. A looser thermal budget can also reduce the size of the enclosure that houses the emission device and the size of any associated cooling equipment.

[0015] For example, we assume that a 500W optical power with a peak wavelength of 850nm is required at a distance of 2m from the source in order to achieve 8mW / cm 2 Unlike using a 500W continuous wave transmitter (i.e., emitting non-pulsed waves at a substantially constant power over time), a pulsed 500W transmitter can also achieve 8mW / cm at a distance of 2m from the source with lower electrical power consumption. 2 The target power density is determined by pulsing. For example, if the emitted radiation is pulsed (or if the emitter is driven to emit radiation) with a pulse frequency of 1 Hz and a pulse duration of 2 ms (i.e. a duty cycle of 0.2%), the electrical power consumption is 500 times lower compared to continuous wave emission. The average optical power in pulsed mode will now be 1 W instead of 500 W, because the radiation is present during 1 / 500 of a second. Since the average optical power emitted is reduced by a factor of 500 in pulse frequency and pulse duration by pulsing, the electrical power consumption will also be reduced by the same factor of 500 (assuming similar efficiencies of the continuous wave electronic driver unit and emitter compared to the pulsed mode electronic driver unit and emitter).

[0016] The cost-saving benefits of pulsing radiation sources are further elaborated here. The maximum drive current of several types of radiation sources (such as light emitting diodes) is limited by thermal requirements: too much drive will overheat the diode and reduce the radiation efficiency. If the lighting device needs to output more PBM-induced radiation than the allowable drive current of the radiation source can provide, a larger number of radiation sources are required, or the type of radiation source must be changed. Both options can be costly. However, if the radiation source is pulsed, the allowable drive current can be further increased because the radiation source can cool between pulses. In other words, pulsing allows a given radiation source to push up or enhance the amount of its allowable drive current. This allows smaller and cheaper radiation sources and / or a smaller number of radiation sources to be used in a lighting device that provides a fixed amount of PBM-induced radiation. In one embodiment, the radiation source and the driver unit are adapted to operate in a drive mode with an enhanced allowable drive current.

[0017] In the scenario of this article, if the drive current during the pulse exceeds the DC allowable drive current specified by the manufacturer, the radiation source is driven by an enhanced allowable drive current. In the example where the radiation source is an infrared LED, the manufacturer typically specifies a maximum rated value for the forward current, such as 1A DC. The maximum rated value at DC (in continuous wave drive mode) does not mean that the maximum rated value can never be exceeded; it means that such maximum rated value cannot be exceeded in continuous wave drive mode without adversely affecting at least one aspect of the performance of the radiation source (whether electrical, thermal or optical). The manufacturer may also specify the time when the maximum rated value is exceeded and the difference by which it is exceeded. In the example of an infrared LED, the manufacturer may specify the "pulse handling capability" of the LED, which describes the relationship between the amount of forward current exceeding the maximum rated value in DC and the allowable pulse time length and duty cycle at such forward current.

[0018] Once general lighting equipment is adapted to emit a sufficient amount of power to achieve a specific power density at a specific distance that can induce a PBM response, many advantages are realized. General lighting equipment (such as lamps or overhead lighting) is easy to use and generally convenient, and therefore the need for medical experts to administer PBM radiation is greatly reduced, which amounts to a significant saving of time and financial resources for the recipient of PBM radiation.

[0019] It should be noted that the same adaptation can be made to task lighting or accent lighting. Task lighting can be considered a special form of general lighting, as both provide lighting to aid human vision, but task lighting can be used in places with special lighting requirements, such as sports fields and streets (which require high brightness over large areas). Accent lighting can be used to build visual emphasis and create points of interest for viewers; common applications include emphasizing indoor plants, sculptures, paintings, and other decorations, as well as emphasizing architectural textures or outdoor landscaping. General lighting, task lighting, or accent lighting that can be used in embodiments of the present disclosure include, but are not limited to, luminous surfaces that can be installed in or as part of lighting fixtures or lamps for areas, such as overhead lighting, bedside lighting, kitchen lighting, sports lighting, street lighting, medical lighting, public lighting, bathroom lighting, vanity lighting, track lighting, and mirror lighting. Applicable lighting also includes lighting that illuminates spaces, areas, and surfaces and thereby brightens the environment in which people and animals spend time.

[0020] In addition to the above advantages, the user can naturally stay in the light of general lighting or task lighting or accent lighting equipment or naturally be exposed to its light for a long time without interrupting their activities. This brings flexibility to provide a wide range of doses (measured in energy per unit area). Recall that energy is power multiplied by time. This means that different amounts of doses can be easily achieved by turning on general lighting or task lighting or accent lighting equipment. The simplicity of dosing is achieved by spreading the average daily dose over many hours so that the applied dose never exceeds the recommended dose. Through the pulse method described in this article, the dose is dispersed over a long period of time at a power density that is effective for inducing a PBM response. Although visits to a specialized treatment center for more than 30 minutes are usually considered a nuisance, it is completely common for people to stay in the light of a general lighting device or be exposed to the light for more than an hour or even eight hours without feeling trouble.

[0021] For example, assume that a general lighting device includes an infrared light emitter that has a peak emission of 850 nm and emits in a pulse mode with a pulse frequency of 1 Hz and a pulse duration of 2 ms. In addition, assume that the infrared light emitter has a peak light emission power of 500 W and can therefore transmit 8 mW / cm 2 The light emitter can then deliver about 0.23 J / cm to that location. 2 (8mW / cm 2 Multiply by 8*60*60 seconds) to get the accumulated energy density within eight hours.

[0022] It should be noted that in embodiments where the light source is capable of or suitable for emitting visible light having a color point less than 10 SDCM from the black body line in the CIE XYZ color space, such a light source is suitable for use in general lighting equipment. The reason is that the visible light emitted by such a light source is relatively white in the sense that this type of visible light is suitable for improving the lighting level of a space to assist human vision and / or make it more convenient for people to live and / or work in the space. In some embodiments, the light source is capable of or suitable for emitting visible light having a color point less than 10 SDCM from the black body line in the CIE XYZ color space. In some embodiments, the distance from the black body line in the CIE XYZ color space may be less than 8 SDCM, 7 SDCM, 6 SDCM, 5 SDCM, or 3 SDCM.

[0023] It should be noted that pulsing the radiation source to provide radiation of appropriate duration and / or period to induce a PBM response (e.g., in the NIR band) can greatly reduce the chance of overdose, even if the user stays near a general lighting device for a period much longer than the typical treatment period of 30 or 60 minutes in a specialist center. For example, a medical study showed that beneficial biological responses increase with increasing dose and are effective at about 10 J / cm 2 Further increases in dose may reduce the beneficial PBM response, and if the dose exceeds about 35 J / cm 2 , then it may even cease to be beneficial. Thus, if the user is exposed to about 8mW / cm 2 If the power density level is sustained for more than about 20 minutes, it will be difficult for the user to receive the peak benefit. In other words, a sufficiently short pulse duration and / or period can provide sufficient power density to induce a PBM response while providing a beneficial amount of total energy density (i.e., power per unit area times time) over a wide range of time, such as from a few minutes to 8 hours or more (without overdosing the user). In this way, the user can use the lighting device as if it were a traditional light source without having to worry about when to turn it off (to prevent overdosing), but still receive the benefits of PBM-induced radiation.

[0024] Another benefit of pulsing the radiation source is better safety for the user's eyes by reducing the heat load induced in the cornea of ​​the user's eye by such radiation in the relevant spectrum, which in turn is due to the average power density of the pulsed radiation being low enough to comply with relevant safety regulations and safety limits. For example, the general international standard IEC 62471 requires that lamps intended for general lighting services (GLS) should expose the user's eyes to less than 10 mW / cm2 (to infrared radiation in the wavelength range of 780 nm to 3000 nm for a period greater than 1000 seconds) at a distance at which the lamp produces an illumination of 500 lux. 2 (100W / m 2 For example, at a distance where a lighting device produces 500 lux, its infrared radiation source produces 20 mW / cm 2 A lighting device with a power density of 1000 mW / cm2 can meet this safety requirement by pulsing the infrared radiation source at a 50% duty cycle according to the method described herein. As another example, IEC 62471 requires that a pulsed light source should maintain infrared eye exposure less than 10 mW / cm2 for a period greater than 1000 seconds at a distance of 200 mm. 2 Therefore, only infrared radiation is emitted and produces 8mW / cm at 2m 2 Pulse radiation source (equivalent to 800mW / cm at 0.2m) 2, assuming that the radiation is emitted omnidirectionally and evenly distributed) can be made compliant by pulsing the infrared radiation source with a duty cycle of 1.25%. Therefore, the technical solution of pulsing a radiation source (such as an infrared source) as described herein enables the use of general lighting equipment, where the (infrared) radiation source can be used without combining it with a visible light emitter. For example, photobiostimulation can be induced at night without the need for visible light to disturb the user's sleep. In the safety scenario mentioned above, the pulsing of the (infrared) radiation source is also an enabling element for making PBM applications safe and compliant with IEC 62471 when the visible component of the emitted spectrum is dimmed to a lower illumination level.

[0025] Thus, the lighting device according to the inventive idea behind the first aspect of the present invention is capable of inducing certain local and systemic (whole body) PBM effects. For example, there is a wide variety of medical research literature showing that PBM can stimulate, heal, regenerate and protect human tissue that has been injured, degenerated or is at risk of death. Most importantly, PBM can induce anti-inflammatory, antioxidant and / or mitochondrial enhancement and normalization effects on the human body and its systems. The positive effects on the human body can be further described as biostimulation and anti-allergy; further immunomodulation, vasodilation and anti-hypoxic effects on the blood. Other positive effects may include stimulating brain regeneration, for example after suffering an ischemic stroke, or increasing cognitive function in healthy subjects. Recent studies have further shown that PBM may have a positive impact on the psychological quality of patients suffering from, for example, depression, dementia, Alzheimer's disease, Parkinson's disease, ADHD, ADD, hypertension, testosterone deficiency and PTSD. In addition, skin rejuvenation and reduction of skin aging can be achieved, as well as certain systemic effects that can be described as rejuvenation or slowing of aging of the entire human body. Further preconditioning of the skin or body as a whole, to prepare for certain types of stress, such as before long sunbathing, or as preconditioning before expected high levels of stress, such as extensive exercise, mental stress or stress on the human body associated with high levels of reactive oxygen species, or as preconditioning before exposure to potentially toxic environments, or in cases of direct contact with toxins in possible areas. In addition, it can be used to reduce recovery time after exposure to extensive exercise, mental stress, harmful levels of radiation or toxins. It may also have a positive long-term effect on vision and the overall health of the human eye and may accelerate and improve hair growth. In addition, it may help normalize melatonin levels in the human body and thus improve sleep. It can also help deal with jet lag or other situations of circadian imbalance. In summary, due to the basic positive PBM effects on eukaryotic cells (inducing anti-inflammatory, antioxidant, homeostatic and / or mitochondrial enhancement and normalization effects), positive effects may be achieved in any part of the human body. Some of the benefits mentioned may also apply in a similar manner to animals such as pets (e.g., dogs, cats) or farm animals (e.g., dogs, cows, horses, pigs); essentially all organisms composed of eukaryotic cells may benefit from exposure to some type of light that causes PBM effects.

[0026] Another advantage of the lighting device according to the inventive concept behind the first aspect of the present invention is the ability to provide general lighting, task lighting or accent lighting and PBM induced radiation simultaneously. The same lighting device provides both functions.

[0027] In one embodiment, the predetermined spectrum of radiation emitted by the radiation source may be in the range of 800-1100 nm. The predetermined spectrum may preferably be in the range of 800-870 nm. In one embodiment, the predetermined spectrum may be in the range of 800-1100 nm, with optionally peak emission at about 830, 980 and / or 1060 nm. In one embodiment, the predetermined spectrum may be in the range of 800-870 nm, with optionally peak emission at about 820-850 nm. There is already a wealth of literature demonstrating the therapeutic value of PBM in the infrared band, and the inventors recognize that ranges such as 800-1100 nm and 800-870 nm may be particularly beneficial and / or easy to implement, which makes these embodiments particularly useful.

[0028] In one embodiment, the predetermined spectrum may exclude or not include the visible spectrum.Since the pulsed emission is not within the visible spectrum, the pulses may have very high peak emission without causing any perceptible annoyance to the user.

[0029] In one embodiment, the lighting device may be adapted to provide a second drive current different from the first drive current to the light source. The second drive current may drive the light source. In one embodiment, the second drive current may be a direct current (DC) or an alternating current (AC) or a pulse width modulation (PWM) current. The PWM current may preferably have a pulse frequency in the range of 20000Hz-300000Hz. The second drive current may provide greater flexibility in driving a light source suitable for emitting visible light. In other words, the (visible) light source may be easily driven in a manner different from that of a radiation source suitable for emitting radiation in a predetermined spectrum. Driving a visible light source with DC or AC may further increase the stability of the visible light emitted by the light source. For example, driving a visible light source with a pulse width modulation (PWM) signal may be used to achieve brightness dimming. Such drive currents may be well suited for widely used light sources, such as incandescent bulbs, fluorescent tubes, and different types of LEDs.

[0030] In one embodiment, the driver circuit may be a first driver circuit. The lighting device may further include a second driver circuit adapted to provide a second drive current. Separating the driver circuits for energizing the light source and the radiation source may help prevent one driver circuit from interfering with a light source or radiation source that the driver circuit does not energize.

[0031] In one embodiment, the pulse duration of the first drive current may be in the range of about 0.05-500ms. The pulse duration of the first drive current may optionally be in the range of about 0.1-100ms, preferably about 0.5-20ms, and most preferably about 4-10ms. Other optional ranges of pulse duration may include 1-40ms, 4-40ms, and 8-30ms. According to the research literature, these embodiments may have the advantageous effect of being implemented in practice by available electronic devices, and have special benefits for certain ranges. On the one hand, longer pulses may provide better PBM response; on the other hand, shorter pulses and / or lower duty cycles may enhance the allowable drive current of the radiation source.

[0032] In one embodiment, the pulse frequency of the first drive current may be in the range of about 0.01-10000 Hz. The pulse frequency of the first drive current may optionally be in the range of about 0.1-2500 Hz, preferably about 1-160 Hz. According to the research literature, this embodiment may have the advantageous effect of being implemented by the actual specific implementation of available electronic equipment, and has special benefits for certain ranges.

[0033] In one embodiment, the first drive current may have a duty cycle of no more than 10%, optionally no more than 5%, optionally no more than 1%. A lower duty cycle may allow the radiation source to generate a higher (peak) emission power with the same amount of consumed electrical power. A lower or more fine-tuned duty cycle also helps reduce the chance of overdosing the user. In one embodiment, the first drive current may have an alternating duty cycle, such as a first duty cycle of 1% during a predetermined period and a second duty cycle of 2% during another predetermined period. Multiple duty cycles can increase the flexibility of programming PBM-induced radiation doses at different times.

[0034] Of course, combinations of different ranges of pulse durations and pulse frequencies are possible. It should also be noted that a desired (peak) emission power from a radiation source with a varying amount of consumed electrical power can be achieved by varying the pulse duration, the pulse frequency, or both. This flexibility can allow different forms of power and / or dose and / or electrical power consumption control that can be adjusted to meet specific needs.

[0035] In one embodiment, at least one of the pulse duration, pulse frequency, and duty cycle is selected so that the first drive current can drive the radiation source at an enhanced allowable drive current. Driving the radiation source at the enhanced allowable drive current can achieve a given amount of radiation power density and dose with a lower cost radiation source (which may have a lower allowable DC drive rating) or a smaller number of radiation sources of a given type (which can operate under higher drive conditions to obtain the same radiation output), or both. This can reduce the cost of the lighting device.

[0036] In one embodiment, a pulse may be split into multiple "sub" pulses. For example, assuming a pulse duration of 10 ms and a pulse period of 100 ms (e.g., a pulse frequency of 10 Hz). It may be that a 10 ms "main" pulse is split into sub-pulses with a pulse duration of 80 ns and a pulse period of 100 ns. In this case, the main pulse comprises 100 sub-pulses. It should be noted that the pulse duration of the sub-pulses is not particularly limited as long as it is shorter than the pulse duration of the main pulse. Pulsing with different levels of pulse duration and / or pulse frequency provides further flexibility in adjusting the radiation pattern to suit specific usage needs or to suit specific requirements in associated electronic devices.

[0037] In one embodiment, the radiation source may be adapted to generate radiation in a predetermined spectrum that may be pulsed. The radiation in a predetermined spectrum (e.g., a spectrum capable of inducing a PBM response) is pulsed. Pulsing may allow the peak emission power of the radiation source to be "enhanced" by a desired factor at the same amount of electrical power consumption. Pulsing may also extend the time a user may be exposed to PBM-inducing radiation without overdosing.

[0038] In one embodiment, the peak emission power of the radiation emitted by the radiation source excited by the pulsed first drive current may be at least 25 W, optionally at least 100 W, optionally at least 200 W, optionally at least 500 W. The peak emission power of at least 25 W may result in a peak emission power of at least 1 mW / cm2 measured at a distance of about 0.6 m from the lighting device having a semicircular radiation pattern. 2 , and can ensure that a user of such a lighting device, for example in a desk lamp, receives sufficient power density. A higher peak transmit power can allow the user to still be exposed to sufficient power density even if the user is further away from the lighting device and / or the radiation pattern is different. For example, a peak transmit power of at least 200 W can result in at least 1 mW / cm2 measured at a distance of, for example, 1.8 m from a lighting device having, for example, a semicircular radiation pattern. 2 This may be suitable for other common usage scenarios of general lighting equipment, such as in an office setting.

[0039] In one embodiment, the peak emission power of the radiation emitted by the radiation source receiving the pulsed first drive current may be sufficient to induce a photobiomodulation (PBM) response in a human body. This will provide added value over other general lighting devices with only traditional light sources.

[0040] In one embodiment, the peak emission power of the radiation source receiving the pulsed first drive current can be such that 0.4-50 mW / cm2 can be measured at a common average distance of between about 0.2 m and about 5 m from the radiation source. 2 , Optional 5-15mW / cm2 The common average distance may optionally be about 0.5 to about 3 m from the radiation source. The common average distance may optionally be about 2 m. The beneficial effects include PBM responses that have been shown to be beneficial to the human body, where 0.4 mW / cm 2 This may be sufficient to begin inducing a PBM response through the eye. This common average distance may also be applicable to many usage scenarios.

[0041] In one embodiment, the peak emission power of the radiation source receiving the pulsed first drive current can be such that 0.4-50 mW / cm2 can be measured at a distance where the illumination of the lighting device is about 500 lux (lx). 2 , Optional 5-15mW / cm 2 power density.

[0042] In one embodiment, the radiation source may emit at least 3,000 Joules in a predetermined spectrum over a period of 8 hours.

[0043] In one embodiment, the radiation source receiving the pulsed first drive current may be configured to deliver a dose (energy per unit area) sufficient to induce a PBM response in a human body. In one embodiment, the radiation source receiving the pulsed first drive current may be configured to deliver 0.01-5 J / cm2 measured at a common average distance from the radiation source. 2 The common average distance from the radiation source may be between about 0.2 m and about 5 m. The common average distance from the radiation source may optionally be between about 0.5 and about 3 m, preferably at about 2 m. The beneficial effects include PBM responses that have been demonstrated to be beneficial to the human body. This common average distance may also be applicable to many usage scenarios.

[0044] In one embodiment, the dose may be adjusted by modifying at least one of the amplitude, pulse duration, pulse frequency, and duty cycle of the first drive current. Preferably, the pulse frequency is modified while the pulse duration remains substantially the same. This may be preferable to changing the pulse duration, which may exacerbate droop effects of the epitaxial material in the radiation source when the pulse length is increased due to increased heat load in the radiation emitting epitaxial material. Modifying the pulse frequency may also be preferable to changing the amplitude, because too low an amplitude may reduce the power density delivered during the pulse, thereby reducing the efficacy of inducing a PBM response in the user. An exemplary threshold for maintaining efficacy is at least 0.4 mW / cm 2 NIR light, for example between 800-870 nm, at a distance from the user to the lighting device where the illumination of the lighting device reaches about 500 lux.

[0045] In one embodiment, the radiation source in use may consume less than 50 W, optionally less than 25 W, optionally less than 10 W of root mean square (RMS) electrical power. Such power consumption levels may be well suited for everyday use, and in light of growing environmental awareness, may help lighting devices meet various energy consumption regulations. In one embodiment, the radiation source in use may consume less than 10 W, optionally less than 2 W, optionally less than 0.5 W of root mean square (RMS) electrical power per square meter of intentionally irradiated surface. RMS electrical power per square meter may be a useful metric for certain lighting applications where large areas are illuminated, such as sports field lighting.

[0046] In one embodiment, the radiation source may include a solid-state device. The solid-state device may be an LED, optionally more than one LED. These devices are readily available and are numerous. In one embodiment, the solid-state device may be a flip-chip LED, which may provide better thermal performance and thus provide a higher capability for enhanced allowable drive current. Electrically bonding the flip-chip LED directly to the mounting board may also allow more current to flow, thereby providing a higher degree of enhanced allowable drive current (i.e., a higher crest factor) if a large enhanced allowable drive current becomes useful.

[0047] In one embodiment, the lighting device is adapted to generate visible light from a light source having a luminous flux, which does not have a flicker percentage greater than 40%, preferably does not have a flicker percentage greater than 20%, when the light source is in use. The limited amount of fluctuation of the luminous flux of the light source may increase the comfort of a user of the lighting device (or a general lighting device comprising such a lighting device). In one embodiment, the lighting device may be adapted to generate visible light from the light source without producing flicker perceptible to the human eye. The lack of flicker perceptible to the human eye may increase user satisfaction with the lighting device (or a general lighting device comprising such a lighting device).

[0048] In one embodiment, the light source may emit at least 250 lumens, optionally at least 1000 lumens, optionally at least 2000 lumens. In one embodiment, the correlated color temperature of the light source may be in the range of 1700-6500K, optionally in the range of 2400-5500K. In one embodiment, at a correlated color temperature of about 2700K, the color rendering index of the light source may be in the range of 80-99. Such a light source meets many requirements for general lighting purposes, such as brightness, light color and color rendering, making the lighting device of the embodiments of the present disclosure particularly convenient and acceptable to ordinary consumers. Needless to say, many suitable combinations of lumen specifications, CCT and CRI may be possible. For example, the light source may be a troffer, which is a rectangular luminaire that fits into a modular drop ceiling grid (i.e., 600×600mm or 300×1200mm). Troffer luminaires are typically designed to accommodate standard fluorescent lamps (e.g., T12, T8 or T5), but are now typically designed with integrated LED sources. In this example, the troffer fixture emits 4000 lumens at 4000K color temperature and has a CRI of 80.

[0049] In one embodiment, the light source may consume an electrical power of less than 120 W, preferably less than 80 W, more preferably less than 30 W. Such power consumption may be particularly suitable for home and office use.

[0050] In one embodiment, the light source may comprise a solid state device. The solid state device may comprise an LED, optionally more than one LED.

[0051] In one embodiment, when the lighting device is in use, the ratio of the electrical power consumed by the radiation source to the electrical power consumed by the light source may be no greater than 50%, preferably no greater than 25%, more preferably no greater than 10%, and even more preferably no greater than 5%. In one embodiment, the electrical power consumed by the radiation source may be less than the electrical power consumed by the light source, preferably less than two-thirds of the electrical power consumed by the light source, more preferably less than one-fifth of the electrical power consumed by the light source, and more preferably in the range of about 4-11% of the electrical power consumed by the light source. Since the radiation source consumes less electrical power than the light source, the additional energy cost from the radiation source can be limited. In some embodiments, the user will hardly notice any difference in the energy bill caused by the additional amount of electrical power consumed by the radiation source.

[0052] In one embodiment, the driver circuit is adapted to modify the first drive current in response to an input to the driver circuit. The input may come from a perception sensor coupled to the driver circuit and adapted to turn the first drive current on or off depending on whether the perception sensor detects the presence of a user near it. The input may come from a distance sensor coupled to the driver circuit and adapted to turn the first drive current on or off depending on the detected distance from the user. Another source of input may be data related to the time of day, ambient brightness, season and / or weather, which is remotely provided to the driver circuit or other circuits controlling the driver circuit, which may modify the first drive current to control the amount of radiation delivered to the user. For example, the pulse frequency and thus the radiation dose may increase on days with low ambient light, at night, in winter, and / or on cloudy days when the user is exposed to less sunlight, and decrease on days with high ambient light, in summer, and / or on sunny days. Any aspect of the amount of radiation dose delivered that may be modified to affect the first drive current, such as pulse amplitude, pulse period, pulse frequency, and duty cycle. Another source of input may be user data provided by, for example, a user's smart mobile device, which may determine, for example, the amount of time the user has stayed indoors and then modify the first drive current accordingly to increase or decrease the radiation dose delivered. In addition to the radiation dose, the power density may also be modified. The power density may be reduced, for example, by reducing the amount of current flowing through the epitaxial material of the radiation source. The purpose may include targeting certain specific photobiological effects without stimulating other photobiological effects. An example is targeting the retina of the human eye. The retina reacts to a lower power density than human skin because, unlike human skin, there is no substantial light absorbing layer on the surface of the human eye. Another reason for modifying the power density may be that the lighting device senses its potential variable distance from the user via a positioning system or a sensing sensor. Such a positioning system or sensor may be part of the lighting device, or may be present in a smart device or other device located at or near the user's body. The ability to maintain a substantially constant amount of power density delivered to the user's body at a variable distance between the lighting device and the user may help maintain a stable delivery of an effective amount of power density to the user's body surface. Improved stability in the delivery of an effective amount of power density may help optimize the photobiological stimulation of a specific biological effect.

[0053] According to another aspect of the present disclosure, a lighting method is provided. The lighting method may include: providing a light source, the light source is suitable for emitting visible light; providing a radiation source, the radiation source may be suitable for emitting radiation in a predetermined spectrum; and supplying a first drive current that may be pulsed and may have a duty cycle of no more than 20% to the radiation source so as to generate radiation in the predetermined spectrum. The light source may be capable of emitting visible light having a color point in the CIE XYZ color space, wherein the distance between the color point and the black body line in the color space is less than 10 color matching standard deviations (SDCM). The predetermined spectrum may be within the infrared band. The predetermined spectrum may be in the range of about 760-1400nm. The first drive current may not be supplied to the light source. The duty cycle may be no more than 20%. By precisely pulsing the radiation source, an appropriate and beneficial amount of radiation in the predetermined spectrum may be provided at a reasonable amount of power consumption. Combining such a radiation source into a general lighting device can greatly expand its use and can transform it into an easy-to-use general lighting source with medical benefits. In addition, the method may have similar embodiments, which have similar effects and advantages to the embodiments of the above-mentioned lighting device.

[0054] According to another aspect of the present disclosure, a lamp for general lighting is provided. The lamp for general lighting may include one of the lighting devices discussed above. In summary, the lamp for general lighting may provide a dual-function visible light source.

[0055] According to another aspect of the present disclosure, a retrofit bulb for general lighting is provided. The retrofit bulb may include one of the lighting devices discussed above. In summary, such a retrofit bulb may provide general lighting and medical benefits. The retrofit bulb may be particularly suitable for working with existing lamp bodies.

[0056] According to another aspect of the present disclosure, a retrofit lamp is provided. The retrofit lamp may include one of the lighting devices discussed above. In summary, such a retrofit lamp may provide general lighting and medical benefits. The retrofit lamp may be particularly suitable for working with existing lamp bodies.

[0057] According to another aspect of the present disclosure, a lighting fixture is provided. The lighting fixture may include one of the lighting devices discussed above. In summary, such a lighting fixture can provide general lighting and medical benefits.

[0058] Further embodiments of the lighting device, lighting method, lamp, retrofit bulb, retrofit lamp tube and lighting fixture according to the present disclosure are given in the appended claims, the disclosures of which are incorporated herein by reference.

[0059] It is clear that the various embodiments described and explained above are mutually compatible with each other, unless explicitly stated. Therefore, any number of combinations of features from the above-described embodiments are still within the present disclosure. For example, different combinations of exemplary predetermined spectra, exemplary (peak) emission power levels of radiation sources, and exemplary brightness of light sources are clearly within the scope of the present disclosure. In addition, features in the above-described embodiments may be canceled or otherwise omitted. For example, the predetermined spectrum may have different emission peaks and valleys within an exemplary range of 800-1100nm. Similarly, the CCT may include discrete sub-domains within a specific exemplary range such as 1700-6500K. Such changes are still clearly within the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings, in which corresponding reference numerals indicate corresponding parts, and in which:

[0061] Figure 1A A lighting device according to an embodiment of the present disclosure is schematically shown.

[0062] Figure 1B A lighting device according to an embodiment of the present disclosure is schematically shown.

[0063] Figure 1C A portion of the CIE XYZ color space including a portion of the blackbody line is shown.

[0064] Figure 1D A portion of a blackbody line is shown with MacAdam ellipses around a certain number of color points along the blackbody line.

[0065] Figure 1E Shows the Figure 1C The blocks shown are segmented.

[0066] Figure 2A A light bulb according to an embodiment of the present disclosure is shown.

[0067] Figure 2B A light tube according to an embodiment of the present disclosure is shown.

[0068] Figure 2C A lamp according to an embodiment of the present disclosure is shown.

[0069] Figure 2D A lighting fixture according to an embodiment of the present disclosure is shown.

[0070] Figure 3 The following illustrates a usage scenario of the lighting device according to an embodiment of the present disclosure.

[0071] Figure 4A graph showing the driving current in the lighting device according to an embodiment of the present disclosure changing over time is shown.

[0072] Figure 5 A graph showing transmitted power from a lighting device over time according to an embodiment of the present disclosure is shown.

[0073] Fig. 6A Allowable pulse handling capabilities of radiation sources suitable for use in embodiments of the present disclosure are shown.

[0074] Figure 6B The measurement results of the driving current and the corresponding radiation according to the embodiment of the present disclosure are shown.

[0075] Fig. 7A A linear lamp according to an embodiment of the present disclosure is conceptually illustrated.

[0076] Figure 7B A lighting device that can be used for a linear lamp according to an embodiment of the present disclosure is schematically shown.

[0077] Figure 8 Exemplary illustrations of troffers that may be used in conjunction with embodiments of the present disclosure are provided.

[0078] Fig.9A Examples of visible light sources and radiation sources that may be used in embodiments of the present disclosure are shown.

[0079] Fig. 9B Shown are measured spectra of a visible light source used in embodiments of the present disclosure, measured averaged over 4 seconds.

[0080] These drawings are for illustration purposes only and are not intended to limit the scope or protection provided by the claims. DETAILED DESCRIPTION

[0081] The following is a description of certain embodiments of the invention, given by way of example only and with reference to the accompanying drawings.

[0082] refer to Figure 1A , which shows a lighting device (which may also be referred to as a “lighting assembly”) 1a according to an embodiment of the present disclosure. The lighting device 1a includes a radiation source 10, a light source 11, and a driver circuit 12. Optionally, the lighting device 1a may include a sensor 14 coupled to the driver circuit 12.

[0083] The radiation source 10 is adapted to emit radiation 100 in a predetermined spectrum including an invisible spectrum. The radiation source 10 emits radiation 100 when receiving a drive signal or being stimulated by a drive signal. The drive signal may be an electrical signal. In one embodiment, the drive signal is a current, such as a first drive current 101.

[0084] The predetermined spectrum is not limited to the invisible spectrum and may optionally include a portion of the visible spectrum. In one embodiment, the predetermined spectrum includes the infrared (IR) spectrum and may optionally also include light in the red (visible) spectrum. In one embodiment, the predetermined spectrum is within the IR spectrum, optionally within the near infrared (NIR) spectrum. In one embodiment, the predetermined spectrum may be in the range of 760-1400nm. The predetermined spectrum may optionally be in the range of 800-1100nm. Another option is the range of 800-870nm. In one embodiment, the predetermined spectrum does not include the visible spectrum.

[0085] Recent advances in medical research have shown that beneficial biological or biochemical responses can be induced by irradiating living organisms with radiation including the IR spectrum and / or red light at specific energy / power levels. This irradiation is generally referred to as photobiomodulation (PBM). Existing medical research results on the medical benefits of using PBM therapy to treat physiological and psychological symptoms are rapidly increasing. Some wavelengths that have attracted special attention include 606, 627, 630, 632.8, 640, 660 and 670nm (in the red region) and 785, 800, 804, 808, 810, 820, 830, 850, 904, 980 and 1060nm (in the NIR region). Some spectra that have attracted special attention include 650-680nm and 800-870nm.

[0086] In one embodiment, the predetermined spectrum is in the range of 800-1100 nm, with an optional peak emission at around 830 nm. Other optional peak emissions include 980 and / or 1060 nm. In one embodiment, the predetermined spectrum is in the range of 800-870 nm, with an optional peak emission at 820-850 nm.

[0087] In one embodiment, radiation source 10 may include a solid state device. In one embodiment, radiation source 10 may include a light emitting diode (LED) and optionally more than one LED. In one embodiment, radiation source 10 may include an LED that emits in the NIR region.

[0088] The radiation source 10 may consume electrical power when in use. There is no particular limit to the amount of electrical power that the radiation source 10 may consume, as long as it is within the limits of the physical capabilities of the equipment used in the radiation source 10. In one embodiment, the radiation source 10 consumes less than 50 watts (W) of electrical power. In one embodiment, the radiation source 10 may consume less than 40 W, 30 W, 25 W, 20 W, 15 W, 10 W, or 5 W of electrical power. The amount of electrical power consumed by the radiation source 10 may be within a range, such as 5-50 W, 10-45 W, and other ranges with the above endpoints.

[0089] The radiation source 10 may have different levels of emitted power, which may have units of watts (W). The radiation 100 emitted by the radiation source 10 may achieve different levels of power density (power per unit area), depending on factors such as the radiation pattern of the radiation source 10 and the distance from the radiation source 10 at which the power density of the radiation 100 is measured. The power density achieved by the radiation 100 describes the amount of (optical) power distributed over a specific surface area, and may have units such as watts per meter (W / m 2 ) or Watts per centimeter (W / cm 2 ) units. For example, assume that the radiation source emits 10W and is a point source with a uniform spherical distribution pattern. The power density received at a distance of 2 meters from the radiation source is 10 / (4π*2^2) = about 0.2 (W / m 2 ).

[0090] The emission power of the radiation source 10 may vary over time. Therefore, while the radiation source 10 may emit radiation 100 with a substantially constant amplitude (which means a substantially constant emission power) over time, it is also possible that the radiation source 10 emits radiation 100 with other time domain characteristics. In one embodiment, the radiation source 10 emits pulsed radiation 100. The pulse may have a pulse duration and a pulse period. The pulse duration is the duration of the pulse. The pulse period represents the frequency of pulse repetition (which may also be described as a "pulse frequency", which is the inverse of the pulse period). It should be noted that the amplitude or intensity of the radiation between pulses is not necessarily zero. Between pulses, there may still be a certain amount of radiation (less than during the pulse), such as radiation induced by transients. In one embodiment, the threshold amplitude or intensity defining the pulse is an amount sufficient to induce a PBM effect in a biological body such as a human body.

[0091] There is no particular limitation on the shape of the pulse. In one embodiment, the pulse may have a rectangular shape. Other shapes are also possible, such as sinusoidal, triangular and sawtooth. Combinations of pulses with different shapes are also possible. In one embodiment, the end of the pulse may be defined as the point at which the amplitude drops below a predetermined threshold. The predetermined threshold may be approximately zero or non-zero. The predetermined threshold may be defined in relative terms, such as a percentage of the peak amplitude, such as 0.001%, 0.01%, 0.1%, 1%, etc. The predetermined threshold may also be defined in absolute terms. Some pulse shapes may be particularly suitable for certain conditions depending on the radiation source, such as delay or attenuation effects related to the material used as the radiation source (e.g., semiconductor or phosphor). A rectangular pulse shape may be advantageous because there are a wide variety of available generators for such pulses, such as integrated circuits. A sinusoidal pulse shape may be beneficial in situations where it is necessary to disperse the radiation power.

[0092] In one embodiment, the emitted radiation 100 is pulsed and may have a pulse duration in the range of about 0.05-500 ms. In one embodiment, the pulse duration may be in the range of about 0.1-100 ms, or about 0.5-20 ms, or about 1-20 ms, or about 4-10 ms. Other ranges of pulse durations, such as 1-40 ms, 4-40 ms, and 8-30 ms, are also possible. Depending on the type of PBM response desired to be induced, other values ​​or ranges of pulse durations are also possible, such as 5 ms, 13.4 ms, 27.78 ms; 16 ms, 8 ms, and 4 ms, each with a pulse frequency of 50 Hz, 100 Hz, and 200 Hz; 8 ms and 40 ms. These values ​​and ranges may be particularly suitable for achieving certain types of medical benefits.

[0093] In one embodiment, the emitted radiation 100 is pulsed and may have a pulse frequency (the inverse of the pulse period) in the range of about 0.01-10000 Hz. In one embodiment, the pulse frequency may be in the range of about 0.1-2500 Hz or about 1-160 Hz. Other ranges of pulse frequencies are also possible.

[0094] A parameter related to the pulse duration and the pulse period (frequency) is the duty cycle. The duty cycle describes the ratio between the period of a pulse and the period between pulses, usually expressed as a percentage. The duty cycle can be defined as the pulse duration divided by the pulse period. In one embodiment, the radiation 100 has a duty cycle of no more than 50%. Other maximum duty cycle values ​​are also possible, such as 40%, 30%, 20%, 10%, 5%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05% and 0.01%. In one embodiment, more than one duty cycle can be used; they can also be used interchangeably. Variable duty cycle directly allows different doses at different times, especially if combined with variable frequency. For certain types of radiation sources whose drive strength is related to the duty cycle (for example, due to thermal constraints), the variable duty cycle can additionally allow different power densities at different times by providing different cooling cycles.

[0095] The pulsed radiation 100 may have a peak emission power. In one embodiment, the peak emission power of the radiation emitted by the radiation source (via, for example, a pulsed drive current) is at least 25 W. In one embodiment, the peak emission power may be at least 50 W, 75 W, 100 W, 150 W, 200 W, 300 W, 400 W, or 500 W. Constraints on the peak emission power include the available electrical power and the number and physical capabilities of the equipment used in the radiation source 10. In one embodiment, the peak emission power of the radiation 100 emitted by the radiation source 10 is sufficient to induce a beneficial photobiomodulation (PBM) response in a human body.

[0096] If the radiation 100 emitted by the radiation source 10 is pulsed, the power density of the radiation 100 measured at a distance away from the radiation source 10 may also vary over time and thus may have peaks and valleys. In other words, if the power density is measured over time and displayed on, for example, an oscilloscope, a pulsed signal may be displayed. In one embodiment, the peak power density achieved by the radiation 100 emitted by the radiation source 10 is 0.4-50 mW / cm 2 and optionally 1-50 mW / cm 2 and optionally 5-15 mW / cm 2 , although other suitable ranges are possible. Depending on the usage scenario, the (peak) power density may be measured at a common average distance between about 0.2 m and about 5 m from the radiation source 10. Preferably, the radiation source 10 may achieve the above power density range at a common average distance of about 0.5 m to 3 m from the radiation source 10. In another embodiment, the (peak) power density may be measured at a distance where the illumination of the lighting device 1a is about 500 lux (lx).

[0097] As is well known, power multiplied by time yields energy. Therefore, the amount of radiation can also be expressed in terms of energy (e.g., joules (J)) or energy density (e.g., J / cm 2 In one embodiment, the radiation source 10 emits at least 3,000 joules in a predetermined spectrum over 8 hours (other energy values ​​and duration values, such as 1, 2, 4, and 6 hours, are also possible).

[0098] The total amount of radiation energy received at a given point during a particular period can be expressed in energy per unit area. This amount may be called the "fluence" or simply the "dose" or "dose", where J / cm 2 are exemplary units.

[0099] In one embodiment, the radiation source 10 may be configured to deliver a dose sufficient to induce a PBM response in a human. Different doses may be required, depending on the type of PBM response to be induced. In one embodiment, the radiation source 10 may be configured to deliver 0.01-5 J / cm2 measured at a common average distance from the radiation source. 2 The common average distance from the radiation source may be between about 0.2 m and about 5 m, depending on the usage scenario. Preferably, the dose may be measured at a common average distance from the radiation source that may be between about 0.5 m and 3 m. In another embodiment, the delivered dose may be measured at a distance where the illumination of the lighting device 1a is about 500 lux (lx).

[0100] The light source 11 is adapted to emit visible light. The light source 11 emits visible light 110 when receiving a drive signal or being excited by a drive signal. The drive signal may be an electrical signal. In one embodiment, the drive signal is an electric current, such as a second drive current 111. The light source 11 may be used for the purpose of any one of general lighting, task lighting, and accent lighting. In some embodiments, the emitted visible light 110 may have a color point that is less than 10 SDCM away from the black body line in the CIE XYZ color space. In some embodiments, the color point may be within 8 SDCM, 7 SDCM, 6 SDCM, 5 SDCM, or 3 SDCM from the black body line. This type of light may be useful for the purpose of general lighting, task lighting, and accent lighting.

[0101] In the context of this article, "general lighting" (which may sometimes be referred to as "general lighting") means that it is not special-purpose lighting that is not just lighting that assists human vision (e.g., killing bacteria, growing plants, detecting cracks, medical treatment, tanning). It means that when a space is too dark for people to work / live in it and its lighting level must be increased, the embodiments of this article can be used for the purpose of increasing the lighting level of the space so that people can live and work in the space conveniently.

[0102] In the context of this document, "task lighting" refers to forms of general lighting that have more specific applications, such as for sports fields, hospitals, open streets, and highways. Task lighting may require higher output to achieve higher brightness and / or cover larger areas than general lighting. In the context of this document, "accent lighting" refers to forms of lighting that are intended to create visual emphasis, with common applications including emphasizing indoor plants, sculptures, paintings, and other decorations, and emphasizing architectural textures or outdoor landscaping.

[0103] The color of light may be described as a point in a color space, such as the CIE XYZ color space. The color of visible light 110 for general lighting purposes is not limited to strictly white light, which occupies a very small region (if not a single point) in the color space. Exemplary color points that may be considered suitable for general, task, or accent lighting purposes include the black body line, a portion of the black body line, and color points within a specific distance from (a portion of) the black body line.

[0104] The black body line is a collection of color points in the CIE color space of electromagnetic radiation emitted by a black body at various black body temperatures. Different black body temperatures result in different hues. For example, an incandescent lamp may emit light at 2700K, which exhibits a reddish or orange hue, often referred to as "warm" white light. Hues at higher temperatures, such as 4000K and 6500K, are whiter and are sometimes referred to as "cooler".

[0105] Color points suitable for general lighting, task lighting, or accent lighting purposes are not limited to color points on the black body line, and may include color points within a certain distance from the black body line. This may be the case for non-black body radiation light sources such as fluorescent lamps and LEDs.

[0106] Figure 1C A portion of the CIE XYZ color space from the ANSI C78.377-2008 standard is shown. The color space shown includes a portion of the black body line, labeled the "Planckian locus." Six ellipses (referred to as 7-step MacAdam ellipses) indicate the boundaries of the areas within 7 SDCM of the color points on the black body line corresponding to 2700K, 3000K, 3500K, 4000K, 5000K, and 6000K, respectively. One of ordinary skill in the art understands that SDCM has the same meaning as MacAdam ellipses. Visible light having a color point within 7 SDCM of a point on the black body line (preferably a point between 1700K and 6500K) may still be perceived by the naked eye as relatively white and may be suitable for general lighting, task lighting, or accent lighting purposes.

[0107] Figure 1D A portion of the black body line in the CIE XYZ color space is shown with four MacAdam ellipses around each of the color points corresponding to 2700K, 3000K, 3500K, 4000K, 5000K, and 6000K. The four MacAdam ellipses indicate 7SDCM, 5SDCM, 3SDCM, and 1SDCM away from the corresponding color temperature, respectively. Visible light having a color point within any of the shown MacAdam ellipses may be suitable for general lighting, task lighting, or accent lighting purposes.

[0108] Back to reference Figure 1C Another way to indicate a color point that may be suitable for general lighting, task lighting, or accent lighting purposes is by segmentation, such as in Figure 1C The ANSI C78.377-2008 block standard for various quadrilaterals is indicated. Figure 1C The blocks shown are not exhaustive. For example, Figure 1E A more precise specification is shown. Figure 1C Segmentation of the block shown.

[0109] In one embodiment, the light source 11 (or the lighting device 1a including the light source 11) may be adapted to generate visible light 110 whose luminous flux does not fluctuate by more than 20% or 15% or 10% or 5% or 3% when the light source 11 is used. The visible light 110 with limited luminous flux fluctuation has less flicker and is therefore more suitable for general lighting. In one embodiment, the light source 11 (or the lighting device 1a including the light source 11) may be adapted to generate visible light with no perceptible flicker to the human eye, for example, a very small amount of flicker or flicker only at a frequency that is too high to be perceived by the human eye.

[0110] In one embodiment, the light source 11 can emit at least 25 lumens, which is equivalent to about two candles. Such a light source can be used for home decoration purposes. In one embodiment, the light source 11 can emit at least 100 lumens. In one embodiment, the light source 11 can emit at least 300 lumens, which is suitable for general lighting purposes in the home. Other amounts of luminous flux may also be suitable for general lighting in, for example, an office or factory environment.

[0111] In one embodiment, the correlated color temperature (CCT) of the light source 11 emitting visible light 110 is in the range of about 1700-6500K, optionally in the range of about 2400-5500K, optionally in the range of about 4000-5500K. In one embodiment, the color rendering index of the light source 11 emitting visible light 110 is in the range of 80-99 at a correlated color temperature of about 2700K. For general lighting purposes, such light sources are more easily accepted by human users than, for example, monochromatic R, G or B light sources. Needless to say, many suitable combinations of lumen specifications, CCT and CRI are possible.

[0112] The light source 11 may consume electrical power. In one embodiment, the light source 11 may consume electrical power less than 120 W, optionally less than 80 W, optionally less than 30 W, depending on the power requirements of the usage scenario of the lighting device 1 a.

[0113] Many light sources used for general lighting can be used as light source 11. In one embodiment, light source 11 may include an incandescent bulb, a halogen bulb, or a fluorescent tube. In one embodiment, light source 11 may include a solid-state device. In one embodiment, light source 11 may include a light emitting diode (LED) or more than one LED. The type of LED is not particularly limited.

[0114] The radiation source 10 and the light source 11 may each consume electrical power. In one embodiment, when the lighting device 1a is in use, the radiation source 10 may consume a certain fraction of the electrical power consumed by the light source 11. The fraction may be no greater than 50%, optionally no greater than 25%, optionally no greater than 10%, optionally no greater than 5%. A lower fraction means that in addition to the benefits of general illumination provided by the light source 11, the user of the lighting device 1a can obtain the additional benefits of PBM-induced radiation at a lower marginal power consumption. The amount of electrical power consumed by the radiation source 10 can also be expressed as a fraction of the total electrical power consumption of the combined radiation source 10 and light source 11, for example, less than two-thirds, less than one-fifth, or in the range of about 5%-10%.

[0115] The driver circuit 12 may provide a drive signal to drive or excite the radiation source 10 and the light source 11. In one embodiment, the driver circuit 12 may provide a first drive current 101 to the radiation source 10 and a second drive current 111 to the light source 11. The first drive current 101 and the second drive current 111 may be different from each other. In one embodiment, the driver circuit 12 may provide the first drive current 101 to the radiation source 10 but not to the light source 11; and / or the driver circuit 12 may provide the second drive current 111 to the light source 11 but not to the radiation source 10.

[0116] In one embodiment, the first drive current 101 may be pulsed and have a duty cycle of less than 20%, optionally less than 10%, optionally less than 5%.In one embodiment, the first drive current 101 is not provided to the light source 11 in pulsed form.

[0117] In one embodiment, the radiation source 10 may be such that it reacts almost instantly (i.e., without delay or with a negligible amount of delay) to the first drive current 101, in which case the manner in which the first drive current 101 varies over time and the manner in which the radiation 100 emitted by the radiation source 10 varies over time are similar or substantially identical to each other. For example, if a modern solid-state radiation device (such as an LED) that can react quickly to a drive current is used as the radiation source 10 and is driven by a pulsed drive current 101, the radiation 100 emitted by the radiation source 10 is also pulsed with similar pulse parameters (such as peak intensity, pulse duration, pulse period / frequency, duty cycle, etc.).

[0118] In one embodiment, the second driving current 111 driving the light source 11 may also be pulsed. An example is to use pulse width modulation to implement dimming control in LED general lighting equipment. In one embodiment, the second driving current 111 may be DC or AC, which may be required by a specific light source. In one embodiment, the second driving current 111 may drive the light source 11 in a continuous wave (CW) mode.

[0119] The optional sensor 14 may provide an input 141 to the driver circuit 12. The driver circuit 12 may modify the first drive current 101 in response to the input 141. For example, the sensor 14 may be a perception sensor or a distance sensor that instructs the driver circuit 12 to turn the first drive current 101 on or off depending on the presence and / or distance of the user. In some embodiments, what is coupled to the driver circuit 12 is not a "sensor" in the strict sense, but a more general source of information that may or may not be present within the lighting device 1a. For example, the input 141 may be weather or user data from a user's smart mobile device.

[0120] It should be noted that the lighting device 1a may include Figure 1A Circuit blocks / elements not explicitly drawn in the figure, such as external power supply, switch, ballast and ground pin. Additional circuit blocks / elements may also exist between the radiation source 10 and the driver circuit 12 and / or between the light source 11 and the driver circuit 12 to achieve various purposes, such as controlling the first drive current 101 and the second drive current 111.

[0121] Figure 1B 1 shows an illumination device 1b according to an embodiment of the present disclosure. Compared to the illumination device 1a, the illumination device 1b also includes a driver circuit 13. The driver circuit 13 is optional. The addition of the driver circuit 13 can provide greater flexibility in driving the light source 11. For example, the light source 11 can be easily driven in a different manner from the radiation source 10. In addition, separating the driver circuits for exciting the light source 11 and the radiation source 10 can help reduce interference and crosstalk.

[0122] Figures 2A-2D Different embodiments incorporating the lighting device discussed above according to the present disclosure are schematically shown.

[0123] Figure 2A A light bulb 2a is shown that includes a lighting device 1a. The light bulb 2a can be a retrofit light bulb that an average consumer will find familiar and easy to use. The light source 11 in the lighting device 1a can provide sufficient visible light 110 to make the light bulb 2a suitable for general lighting purposes. The visible light 110 can be sufficient in both quantity (e.g., sufficient brightness) and quality (e.g., no flicker, comfortable color, etc.). After installing and turning on the light bulb 2a, the user not only receives visible light 110 for lighting, but is also exposed to radiation 100 that can induce beneficial PBM responses in the human body. That is, the light bulb 2a according to an embodiment of the present disclosure achieves two functions, making it far more useful than traditional light bulbs.

[0124] Figure 2BA lamp 2b is shown comprising the lighting device 1a. The lamp 2b may be a retrofit lamp that the average consumer will find familiar and as easy to use as a conventional fluorescent lamp. The lamp 2b may be adapted to fit into a standard fluorescent lighting fixture. Similar to the light bulb 2a, the lamp 2b may provide dual functionality (general lighting and health benefits) to its user.

[0125] Figure 2C A lamp 2c is shown that includes the lighting device 1a. The lamp 2c can be an off-the-shelf lamp that is adapted to easily fit with existing standard accessories. An average consumer can buy the lamp 2c and use it without having to call an electrician to fit a standard accessory, while providing the user with the same great versatility and benefits as the lighting device 1a. In one embodiment, the lamp 2c can be customized to fit with a specific accessory.

[0126] Figure 2D A lighting fixture 2d including the lighting device 1a is shown. The lighting fixture 2d may include a lamp fitting for accommodating the lighting device 1a or a lamp including the lighting device 1a, and may optionally include decorative elements (such as a shade, a base and / or a housing). The lighting fixture 2d can be used, for example, in a home or office environment, and may include additional light sources to meet additional lighting requirements. In one embodiment, the lighting fixture 2d may be provided as a ready-made product, in which all elements of the lighting device 1a are already installed in the lighting fixture 2d. A user can purchase such a lighting fixture 2d, provide it with electrical power, and directly enjoy the dual benefits of general lighting and medical benefits.

[0127] Some elements of the lighting device 1a may be mounted outside the lighting fixture 2d. For example, the radiation source 10 and the light source 11 may be mounted inside the lighting fixture 2d, while the driver circuit 12 is placed outside but connected to the lighting fixture 2d. If the radiation source 10 and the light source 11 are driven by two driver circuits, one of the driver circuits may be mounted inside the lighting fixture 2d and the other may be placed outside the lighting fixture 2d. More than one lamp may also be used, with some elements of the lighting device 1a mounted in one lighting fixture and other elements of the lighting device 1a mounted in another lighting fixture. For example, the radiation source 10 and the driver circuit 12 may be mounted on one lighting fixture, and the light source 11 and the driver circuit 13 may be mounted on another lighting fixture. It is also possible to mount the radiation source 10 on one lighting fixture and the light source 11 on another lighting fixture, and to mount the driver circuit 12 on the outside of both lamps, but to connect them.

[0128] Although the lighting device 1a Figures 2A-2D , but this is obviously not restrictive.

[0129] Figure 3 The figure shows a usage scenario of the lighting device 1a according to an embodiment of the present disclosure.

[0130] exist Figure 3 , the lighting device 1a emits radiation 100 and visible light 110. The user 20 is at a distance d from the lighting device 1a. The distance d may be, for example, 1 meter. The visible light 110 illuminates the surroundings of the user 20. The user 20 is exposed to the radiation 100. The power density achieved by (or produced by) the radiation 100 to which the user 20 is exposed depends on factors such as the distance d and the radiation pattern.

[0131] As a non-limiting example, assume that the radiation source 10 has a light emission power of 500 W and a light peak wavelength of 850 nm, so that 8 mW / cm 2 If the radiation source 10 is operated in CW mode (ie, with a non-pulsed, substantially constant emission of 500 W), the amount of electrical power required is 1000 W, assuming an electrical-to-optical power conversion efficiency of 50%.

[0132] In the above non-limiting example, a user 20 at a distance of 2 m may be exposed to 8 mW / cm2 sufficient to induce a PBM response. 2 The power density of the user 20 is 8 mW / cm 2 Multiply by the exposure time.

[0133] The radiation source 10 of the above non-limiting examples may be operated or driven in different ways that may provide additional benefits, as described below.

[0134] See also Figure 4, which shows a graph of various drive currents over time in a lighting device according to an embodiment of the present disclosure. Curve 30 represents the first drive current 101, and curve 31 represents the second drive current 111. As shown, the first drive current 101 represented by curve 30 is pulsed, while the second drive current 111 represented by curve 31 is not pulsed. The non-pulsed second drive current 111 can help the light source 11 provide stable visible light suitable for general lighting. However, the second drive current 111 can have different shapes, some examples of which are shown by curves 31-33. For example, the second drive current 111 can be a stable DC current, as illustrated by curve 31. As another example, the second drive current 111 can be a rectified AC current, as illustrated by curve 32. The rectified AC current can have a frequency of, for example, 100 or 120 Hz; such a drive current can be suitable for a visible light source such as an incandescent lamp. As another example, the second drive current 111 can be pulsed, as illustrated by curve 33. Curve 33 may represent a pulse width modulated (PWM) drive current with a pulse frequency in the range of about 20,000 Hz-300,000 Hz, optionally about 50,000 Hz-300,000 Hz. Pulsing the light source 11 at an appropriate frequency may provide dimming control without generating flicker that is perceptible to the human eye. Obviously, Figure 4 The scales in are for illustration only and are not exact.

[0135] like Figure 4 As shown, the first driving current 101 has a pulse duration T d And the pulse period is T. The duty cycle is T d Divided by T. During the pulses, the radiation source 10 operates at maximum emission; between pulses, the radiation source 10 is switched off.

[0136] As a non-limiting example, assume that the pulse duration T d The power consumption is 2 ms and the pulse period is 1 s (ie, a pulse frequency of 1 Hz), i.e. a duty cycle of 0.2%. The radiation source 10 driven in this way will still deliver 8 mW / cm at a distance of 2 m during the pulse. 2 The power density is 100%, but because the radiation is present for 0.2% of the time, the average optical power in pulsed mode becomes 1 W instead of 500 W. This also means that the electrical power consumption is reduced by the same factor of 500.

[0137] That is, by pulsing, the same amount of transmitted power (at the source) and power density (at a certain distance from the source) can be obtained, with a corresponding reduction in electrical power consumption, usually by a large factor. Since devices used for general lighting generally have restrictions on electrical power consumption, pulsing the radiation source 10 can maintain the power density level induced by the PBM response under a tighter electrical power budget. Another result of pulsing the radiation source 10 is that the radiation dose (related to the energy density) received by the user 20 in the same amount of time will be reduced by a corresponding factor. However, the lower dose may actually be a benefit because it reduces the risk of overdose. That is, the user 20 will not worry about when to turn off the lighting device 1a and simply use it as a conventional general lighting source.

[0138] See also Figure 5 , which shows a graph of the emission power of the radiation source 10 and the light source 11 of the lighting device according to an embodiment of the present disclosure over time. Curve 40 represents radiation 100, and curve 41 represents visible light 110. If the radiation source 10 and the light source 11 can react immediately to the corresponding drive signal, the shape of the radiation 100 / visible light 110 will match the corresponding drive signal; if not, delays and transients may occur. For example, the intensity of light emitted by a thermal emitter (such as an incandescent light bulb) driven by a rectified AC current will change more slowly than the rectified AC current due to thermal inertia. As another example, driving an LED with a PWM signal in a sufficiently high frequency range suitable for dimming control can produce light that appears to be substantially constant to the human eye. However, the inventive concepts behind the embodiments will remain substantially the same.

[0139] Depending on the type of radiation source used and the desired amount of PBM-induced radiation, the magnitude, pulse duration, pulse period and duty cycle of the first drive current may vary.

[0140] See also Fig. 6A , which shows the amount of allowable drive current (along the vertical axis) under different conditions of pulse duration (along the horizontal axis) and duty cycle (represented by the family of curves) for a common type of high power SSL radiation source with a centroid wavelength of 850nm.

[0141] It is well known that several types of radiation sources have thermal constraints that limit their allowable drive current. Light emitting diodes are an example: excessive forward current can raise the junction temperature so high that it reduces the radiation output and thus reduces efficiency. However, pulsing combined with a selected amount of duty cycle allows the radiation source to cool between pulses, thereby allowing an enhanced allowable drive current. This can be achieved in Fig. 6AAs can be seen in Figure 1, it relates to the pulsing capability of the LED: if the radiation source is not pulsed (D=1), the drive current is at most 1 A; if the radiation source is pulsed with a duty cycle of 20% (D=0.2) and a pulse duration of 0.1 ms, the drive current can exceed 3.5 A. In other words, pulsing can enable an enhanced allowable drive current to reliably extract more radiation output from the same (number) of radiation sources.

[0142] although Fig. 6A The graphs in relate to a specific type of high power SSL (solid state lighting) near infrared radiation source, but pulsing the radiation source to achieve an enhanced allowable drive current is generally applicable to all SSL radiation sources and is not limited to any specific type of SSL radiation source.

[0143] The effect of pulsing the radiation source was experimentally verified. Figure 6B shows that it is different from Fig. 6A Measurement results of the drive current fed into the light emitting diode and the corresponding radiation output at 850 nm. Figure 6B The top portion shows the drive current averaging at about 2.5 A over about 5 ms. Figure 6B The bottom of the graph shows the measured radiation intensity, which is stable for about 1 ms and then drops by about 28%. This can be explained by the pulse handling capability of the radiation source in use: a drive strength of 2.5 A is permissible if the duty cycle is less than about 20% (the measured radiation intensity starts to drop thermally at 1 ms, which is about 20% of the entire pulse) and the pulse duration is less than about 1 ms.

[0144] The ability of pulses to drive a radiation source with varying degrees of enhancement can be used to reduce the cost of lighting devices that supply a specific amount of PBM-induced radiation. Fig. 6AIt can be seen in Figure 1 that a duty cycle of 2% (D=0.02) and a pulse duration of 5ms can achieve a drive strength of about 2.2A, while the same duty cycle with a longer pulse duration of 10ms can achieve a drive strength of about 1.7A. That is, this example shows that a lighting device whose radiation source is operated with a shorter pulse duration can achieve the same amount of radiation power density with a smaller number (about 20%) of radiation sources than operating the radiation source with a longer pulse duration, thereby reducing the cost of the lighting device. This can be described as using pulses to thermally "quench" the radiation source, otherwise overdriving of the radiation source is impossible. Overdriving can also reduce the cost of the lighting device by allowing the use of, for example, light-emitting diodes with smaller die sizes (cheaper but more thermally restricted) or less thermally favorable packages. Additionally or alternatively, pulsing and especially overdriving can open the door to engineering thermal and mechanical aspects of the radiation source (such as using flip chips or wire bonding and / or designing heat flow between the radiation source and the circuit board) in order to improve electrical (drive strength) and optical (radiation power density) aspects.

[0145] In short, the type of PBM response desired determines the desired radiated power density and sometimes also the minimum pulse duration. The desired radiated power density determines the drive strength of the radiation source employed. The drive strength may be limited by thermal considerations, which can be overcome by more expensive radiation sources. Alternatively, pulsing and overdriving can improve the trade-off between drive strength and cost.

[0146] The following examples illustrate how the inventive concepts behind the embodiments discussed above can be applied in some types of lighting devices. These examples are intended to be illustrative only and are not exhaustive or limiting.

[0147] Example - Linear Light

[0148] Fig. 7A A linear lamp 7 according to an embodiment of the present disclosure is conceptually illustrated.

[0149] For example, the linear lamp 7 may be of T8 or T5 type. The linear lamp 7 may be equipped with LEDs as an alternative to fluorescent technology. The linear lamp 7 may be of different lengths, for example 60 cm, 120 cm and 150 cm designed for standard fluorescent lighting fixtures.

[0150] In this example, it is assumed that the linear lamp 7 is 150 cm and has a uniform light distribution over 180°. It is assumed that the linear lamp 7 comprises a NIR radiation source. At a distance r = 2 m from the light source, the surface area of ​​a theoretical half cylinder (which represents the theoretical light distribution at a distance of 2 m) is A = πrh = ~10 m 2 , or if the total average NIR output power is 1W, then 1m 2 / 0.1W. Therefore, if the user 20 is 2 meters away from the linear lamp 7, the average power density in the NIR spectrum at the skin surface of the user 20 is about 10uW / cm 2 (0.1W / m 2 ).

[0151] It is also assumed that the linear lights are typically placed in a grid. Therefore, at an average distance of 2m from the linear lights, the cumulative average power density on the user's skin is estimated to be about 60% higher on average, which results in about 16uW / cm 2 This gain is achieved by the overlap of beams and the accumulation of diffuse light from adjacent linear lights placed in a specific common grid of linear lights. The 60% value is estimated based on actual experience with linear lights installed in actual offices and may vary in reality depending on the beam pattern, the distance between linear lights and other factors such as the reflectivity of the relevant surfaces.

[0152] Medical research shows that the human skin is exposed to 1-50mW / cm 2 The inventors have also recognized that an average NIR power density in the range of about 5-15 mW / cm at human skin can induce a beneficial PBM response. 2 , more specifically about 8mW / cm 2 The average NIR of 100 nm can induce a particularly beneficial PBM response because this power density range at the skin can result in a power density of about 0.4-1 mW / cm in a specific target layer of the skin (dermis). 2 This is higher than the 16uW / cm2 that linear lamps can deliver. 2 500 times higher. The 500-fold difference translates to a total average near-infrared output power of 500 W required for the NIR radiation source in the linear lamp. This amount of NIR output power means an electrical power consumption of more than 500 W (taking into account other factors such as non-ideal efficiency), which, while still possible, may not be suitable for certain usage scenarios (such as general lighting for home use).

[0153] If the NIR radiation source is pulsed with a pulse duration of 2 ms and a pulse period of 1 s (equal to a duty cycle of 0.2%), the NIR radiation source still outputs 500 W during the pulse, but the average electrical power consumption over time is reduced by a factor of 500 (i.e. equivalent to 1 W continuous wave (CW)).

[0154] A possible implementation is to use 200 NIR LEDs distributed over 150 cm, where each NIR LED has a peak output power of 2.5 W (still pulsed at 2 ms / s). Given the above light output power and pulse parameters, the amount of energy emitted by the radiation source after 8 hours is about 1 (W) * 8 (hours) * 60 (minutes / hour) * 60 (seconds / minute) = 28800 (J). The dose delivered to the user's skin at a distance of 2 meters after 8 hours is about 16 (uW / cm 2 )*8(hours)*60(minutes / hour)*60(seconds / minute)=460800(uJ / cm 2 )=0.4608(J / cm 2 ). This dose may be suitable for inducing a specific beneficial PBM response.

[0155] Assuming a 50% electrical-to-optical power conversion efficiency of the NIR LED, this specific implementation of the NIR radiation source consumes 2 W of electrical power on average.

[0156] Assume that the linear lamp 7 also includes a light source for general lighting that consumes 30W of electrical power, which is not uncommon for home use. Then, the linear lamp 7 will consume a total of 32W of electrical power, of which 30W is dedicated to visible light for general lighting, and 2W is dedicated to pulsed NIR radiation that can induce a beneficial PBM response. That is, the linear lamp 7 can impart two benefits to its user 20: general lighting and medical benefits.

[0157] Figure 7B Schematically, a lighting device 1c is shown that can be used in a linear lamp 7. The radiation source 10 can include a plurality of LEDs 70, whose number and light characteristics can be similar to those described. The light source 11 can include a plurality of LEDs 71 that provide visible light for general lighting. A driver circuit 12 can provide a pulsed drive current so that the radiation source 10 emits NIR radiation with the above-mentioned characteristics. Another driver circuit 13 can provide a non-pulsed drive current so that the light source 11 emits visible light for general lighting.

[0158] The above examples are non-limiting, as the following variations will demonstrate.

[0159] Variant 1

[0160] In order to increase the dose (energy density), the pulse duration or pulse frequency can be increased (i.e., the pulse period is reduced). Increasing the pulse frequency may be advantageous because some medical research results show that shorter pulses can enable a higher dose response (i.e., excitation and relaxation of ion channels) to be achieved compared to longer pulses. However, higher pulse frequencies and the same pulse duration require higher electrical power consumption.

[0161] As an example, assume that the pulse frequency is increased from 1 Hz to 10 Hz and the pulse duration is maintained at 2 ms. The resulting 8-hour dose to the user will be 0.46 J / cm 2 Increased to 4.6 J / cm 2 The electrical power consumption will also increase by a factor of 10, from 2 W electrical power to 20 W electrical power (assuming the same 50% conversion efficiency (WPE) of the NIR emitter).

[0162] Variant 2

[0163] In this variation, the pulse frequency was increased from 1 Hz to 1.5 Hz, resulting in 0.6912 J / cm 2 The 8-hour dose is 0.4608 J / cm 2 In this variant, the power consumption will also increase by 50%, from 2W electrical power to 3W electrical power (assuming 50% WPE of the NIR emitter).

[0164] Variant 3

[0165] In this variant, the pulse duration was reduced from 2 ms to 1 ms, and the pulse frequency was reduced from 1 Hz to 0.5 Hz (i.e., a 1 ms pulse was delivered every 2 seconds). The power consumption was then changed to 0.5 W (at 50% WPE), and the daily dose (8 h exposure) was reduced by a factor of 4 to 0.1152 J / cm 2 .

[0166] Assume that 30 W of electrical power is dedicated to a light source that emits visible light for general illumination (white light LED as an example). Therefore, the electrical power consumed by the NIR radiation source (0.5 W) is about 1.64% of the total 30.5 W. That is, the additional benefit of PBM-induced NIR radiation is provided at the cost of only less than 2% additional power consumption. The user will hardly notice such an increase in his energy bill.

[0167] Variant 4

[0168] In this variant, the pulse length is 1 ms (50% of 2 ms) and the pulse frequency is 5 Hz (five times 1 Hz). The resulting electrical consumption is 5 W (at 50% WPE), and the daily dose to the skin (8 h exposure) becomes 1.152 J / cm 2 .

[0169] Assume that 30W of electrical power is dedicated to a light source that emits visible light for general illumination (white light LED as an example). Then the power consumed by the NIR radiation source (5W) is 14.29% of the total power 35W.

[0170] Variant 5

[0171] In this variant, the pulse length is 5 ms (250% of 2 ms) and the pulse frequency is 1 Hz. The resulting electrical consumption is 5 W (at 50% WPE) and the daily dose (8 h exposure) to the skin (at the same average distance of 2 m) becomes 1.152 J / cm 2 .

[0172] Variant 6

[0173] In this variant, the radiation source includes 100 NIR LEDs (or laser LEDs, or other solid-state lighting (SSL) sources) with peak emission at 800nm ​​and 100 NIR LEDs (or laser LEDs, or other SSL sources) with peak emission at 850nm instead of 200 identical NIR LEDs. The pulse parameters, light emission power and electrical power consumption remain unchanged.

[0174] In this variant, the total light emission power (intensity) is achieved by two emitters with different wavelengths. This variant shows that the power emitted from the lamp and the power density and energy density delivered to the user's skin can also be accumulated by more than one NIR emitting device with different emission spectra within the NIR light spectrum.

[0175] Variant 7

[0176] In this variant, the radiation source includes 100 NIR LEDs (or laser LEDs, or other solid-state lighting (SSL) sources) with peak emission at 850 nm and 100 NIR LEDs (or laser LEDs, or other SSL sources) with peak emission at 980 nm instead of 200 identical NIR LEDs. The pulse parameters, light emission power and electrical power consumption remain unchanged.

[0177] This variation again demonstrates that the power density and energy density delivered to the user's skin can include different spectra within the NIR light spectrum.

[0178] Variant 8

[0179] In this variation, the 200 NIR LEDs (or laser LEDs, or other SSL sources) all have peak emission at 980 nm.

[0180] Typically, the human eye is able to see light at 760-780nm, but some people have vision extending to about 1000nm. This variation may be useful for people with extended vision into the NIR. Other suitable peak emission positions include 1060nm.

[0181] Variant 9

[0182] In this variant, the radiation source in the linear lamp includes 150 NIR LEDs (or laser LEDs, or other SSL sources) with peak emission at 850nm, and the peak emission of each NIR LED is 3.33W instead of 2.5W. The accumulated total peak intensity is still 500W. Therefore, other relevant parameters remain unchanged.

[0183] This variation demonstrates that either the peak emission level of individual radiating devices or their number can be varied to accommodate changes in the other while achieving the same overall peak emission.

[0184] Variant 10

[0185] In this variant, the target peak power density is approximately 32 mW / cm 2 , NIR radiation at the skin is 850nm. Such intensities (1-50mW / cm discussed earlier in this disclosure) 2 The upper end of the range) may be beneficial at certain locations in the body where deeper penetration of radiation is particularly useful.

[0186] Studies have shown that such power densities are beneficial if the human brain is targeted to treat certain diseases, such as major depression, Alzheimer's disease and dementia. Therefore, such higher intensities may be beneficial in nursing homes or psychiatric hospitals.

[0187] Studies have also shown that NIR light between 800-1100nm at such intensities is beneficial in increasing concentration and / or focus in healthy subjects, also achieved by targeting the brain at similar power densities as described in this variant. Therefore, in environments where enhanced cognitive function is required, it may be beneficial to use power densities at slightly higher power densities, where the benefits will outweigh the marginal increase in electrical power consumption. Lamps of this variant with cognitive enhancement properties may be suitable for use in schools, universities, offices, conference rooms, stages, or other places with similar requirements.

[0188] Assume a 150 cm linear lamp with uniform light distribution over 180°. At a distance r = 2 m from the light source, the surface area of ​​a theoretical half cylinder (which represents the theoretical light distribution at a distance of 2 m) is A = πrh = about 10 m 2 If the CW NIR output power is 2W, this will produce a 1m 2 / 0.2W.

[0189] It is also assumed that the linear lights are typically placed in a grid. Therefore, at an average distance of 2m from the linear lights, the cumulative average power density on the user's skin is estimated to be 60% higher on average, which results in about 32uW / cm 2 This is better than 32mW / cm2 The intended target is 1000 times lower and indicates that the (peak) NIR output power at the radiation source should be 1000 times 2 W, i.e. 2000 W.

[0190] If the NIR radiation source is pulsed with a pulse duration of 1 ms and a pulse period of 1 s (equal to a duty cycle of 0.1%), the NIR radiation source still achieves a peak emission power of 2000 W during the pulse process, but the average electrical power consumption over time is reduced by a factor of 1000 (i.e., equivalent to 2 W continuous wave (CW)).

[0191] Assuming a length of 1.5m can accommodate 200 spread out NIR LEDs, this would reduce the desired single LED peak intensity to 10W (pulsed at 1ms / s). This could be achieved with, for example, laser LEDs, which can withstand shorter and more intense pulses over their lifetime.

[0192] After 8 hours the resulting dose to the user at a distance of 2 meters is about 32 (uW / cm 2 )*8(hours)*60(minutes / hour)*60(seconds / minute)=921600(uJ / cm 2 )=0.9216(J / cm 2 ).

[0193] The NIR radiation source will consume an electrical power of 4 W. If the lamp comprises a visible light source for general lighting consuming 30 W, the total electrical consumption of the lamp of this variant will be 34 W.

[0194] Example - "Rejuvenation Mirror"

[0195] PBM-inducing radiation can be added to the mirror. This can add PBM to a morning routine, for example.

[0196] Assume that the NIR LED has uniform light distribution in the hemisphere (the calculation method explained below can be applied to other distribution patterns, such as focused or Lambertian). At a distance r from the lamp, the surface area of ​​the hemisphere is A = 2πr 2 For example, if the average distance r is 0.66 m, then A is about 27370 cm 2 .

[0197] Assuming about 8mW / cm2 is expected in the 800-870nm range on the skin 2 The radiation source should then emit NIR radiation in the range of 800-870 nm with an optical power of approximately 8 mW / cm 2 *27370(cm 2) = about 219 W. (In terms of useful NIR emission, this is about equivalent to 20 100-watt incandescent bulbs mounted around a mirror with a reflector.)

[0198] Techniques to adjust the radiation pattern, such as favorable Lambertian emission or optically focused LED emission, can reduce the required emission power at the radiation source from 219 W to 100 W. This can be achieved, for example, with 100 NIR LEDs, each with 1 W peak emission at 850 nm and a FWHM of 30 nm.

[0199] 100 NIR LEDs can be pulsed with a pulse duration of 10 ms and a pulse frequency of 10 Hz (i.e. the LEDs are switched on for 10 ms every 0.1 s, equivalent to a total on-time of 100 ms / s). Assuming a WPE of 50% for the NIR light source, the resulting power consumption will be 20 W. The dose delivered to the skin surface at distance r is 48 mJ / cm 2 / minute. Assume that the user uses the mirror for 20 minutes per day. Then, at the above distance r, the mirror will deliver about 1 J / cm2 to the exposed skin every day. 2 The average energy density (or dose, injection) of

[0200] As an additional feature, the NIR radiation source of the reflector can be switched on by a perception sensor or a motion sensor.

[0201] Variant - Hospital Lighting

[0202] The same concept can also be applied to inpatient lighting in hospitals (such as HCL (human-centric lighting) elements on the end walls of patient beds).

[0203] Assuming a setup similar to the rejuvenation mirror example above, where 100 NIR LEDs with identical light characteristics are located at an average distance of 0.66 m from the patient's face, the device can be designed to automatically turn on 1-2 times a day for 20-100 minutes, delivering 1-5 J / cm each time. 2 .

[0204] Example - Office Lighting Troffer

[0205] Troffers are rectangular lighting fixtures that fit into a modular drop ceiling grid (i.e. 600 x 600mm or 300 x 1200mm). Troffer fixtures can be designed to accommodate standard fluorescent lamps (e.g. T12, T8 or T5) or have an integrated LED light source. Troffers can be recessed above the ceiling grid, or can also be used in a surface mounted "box".

[0206] In this example, a popular troffer from the company Trilux named "Belvision Cl 600CDP LED3900nw 01" is used. It is assumed that the troffer is installed in a room with dimensions of 5 x 4 x 3 meters. To achieve a standard illumination of > 500 lux on an assumed working surface of 75 cm above the floor, we need 3 (rounded from strictly 2,93) luminaires with a surface reflectivity of 70 (ceiling) / 50 (wall) / 20 (floor) % and a maintenance factor of 0.8. Figure 8 Exemplary illustrations of troffers and their use in such rooms are provided.

[0207] The energy consumption of each troffer is 27W, and the total energy consumption of all 3 luminaires is 81W. This results in a power consumption of 27W per m2. 2 The working surface consumes about 4W of power, or 50% of the power consumption per square meter. 2 The light energy consumption is about 2W.

[0208] With the above radiation pattern and surface reflectivity of the room, we achieve 500lx at the work surface, which can also be described as 500lumens / m 2 The total available lumens is 12000lm (4000lm per luminaire), which means that without losses the available lumens is 600lm / m 2 , which shows that due to reflection and absorption losses in the ceiling, walls, and floor, we have 2 A loss of 100lm. Therefore, in this setup, 20% of the initial available lumens emitted by the luminaire are lost.

[0209] The next step is to calculate the amount of light watts in the NIR spectrum per luminaire, assuming the integrated NIR lamps have similar maintenance and reflection losses and similar radiation patterns.

[0210] Assuming a target power density of 8 mW / cm2 for NIR radiation at a similar distance from the ground compared to the work surface (i.e. 75 cm above ground) 2 , with a peak wavelength of 850nm. Taking into account the above 20% loss compared to the initial available optical power at the source, we assume that 10mW / cm2 of the irradiated working surface is required 2 , i.e. 100W / m 2 , or for 20m 2 The total cross-sectional area of ​​(5×4m) is 2000W.

[0211] Therefore, we need 2000W / 3 luminaires = about 667W of peak emission at 850nm / luminaire. This peak emission can be achieved by 200 individual NIR LEDs per luminaire, each with a pulsed peak emission of 3.335W of optical power.

[0212] Assume that the NIR light emission has a pulse frequency of 1 Hz and a pulse duration of 1 ms (rectangular waveform, 100% modulation). Under this pulse parameter, the average emitted light watt at 850 nm is 0.667 W, or 1.333 W electrical power per fixture at 50% WPE, or a total of 4 W electrical power per room (for all 3 fixtures).

[0213] In addition, we assume that the person is exposed to the light for 8 hours or 28800 seconds, and during this time, the skin surface of the person is on average at a similar distance from the light source compared to the working surface. Therefore, the dose (or energy density) reached by the skin surface of the person per day (8 hours of exposure) is on average 8 (mW / cm 2 )*28800(s)*(1 / 1000)=about 0.23(J / cm 2 ).

[0214] Variant 1

[0215] In this variant, we assume that the NIR radiation emission has a pulse frequency of 2 Hz and a pulse duration of 2 ms (rectangular waveform, 100% modulation). At this duty cycle and frequency, the average emitted light watt at 850 nm is 4 times higher than in the above example, resulting in 2.667 W, or 5.334 W of electrical power per lamp at 50% WPE, or a total of about 16 W of electrical power per room (for all 3 lamps). In addition, we assume that the person is exposed to the light for 8 h or 28,800 s, and during this time, the person's skin surface is on average at a similar distance from the light source compared to the work surface. Therefore, the dose (or energy density) reached by the person's skin surface per day (8 h exposure) is about 0.92 J / cm 2 (8mW*28800s*(0.002 / 0.5)).

[0216] Variant 2

[0217] In this variant, we assume that the NIR radiation has a pulse frequency of 3 Hz and a pulse duration of 3 ms (rectangular waveform, 100% modulation). At this duty cycle and frequency, the average emitted optical watts at 850 nm is 9 times higher than in the example, which results in 6 W optical watts, or 12 W electrical power per lamp at 50% WPE, or a total of 36 W electrical power per room (for all 3 lamps). In addition, we assume that the person is exposed to the radiation for 8 h or 28,800 s and that during this time, the person's skin surface is on average at a similar distance from the light source compared to the working surface. Therefore, the dose (or energy density) reached by the person's skin surface per day (8 h exposure) is approximately 2.07 J / cm 2(8mW*28800s*0.003*3).

[0218] Variant 3

[0219] In this variant, we assume that the NIR radiation has a pulse frequency of 1.5 Hz and a pulse duration of 10 ms (rectangular waveform, 100% modulation). At this duty cycle and frequency, the average emitted light watts at 850 nm is 15 times higher than in the example, which results in 10 W light watts, or 20 W electrical power per lamp at 50% WPE, or a total of 60 W electrical power per room (for all 3 lamps). In addition, we assume that the person is exposed to the light for 8 h or 28,800 s, and that during this time, the person's skin surface is on average at a similar distance from the light source compared to the working surface. Therefore, the dose (or energy density) reached by the person's skin surface per day (8 h exposure) is approximately 3.46 J / cm 2 (8mW*28800s*0.010*1.5).

[0220] Variant 4

[0221] In this variant, we assume that the NIR radiation has a pulse frequency of 0.1 Hz and a pulse duration of 5 ms (rectangular waveform, 100% modulation). At this duty cycle and frequency, the average emitted optical watts at 850 nm is 2 times lower than in the example, resulting in 0.333 W optical watts, or 0.667 W electrical power per lamp at 50% WPE, or a total of 2 W electrical power per room (for all 3 lamps). In addition, we assume that the person is exposed to the light for 8 h or 28,800 s and that during this time, the person's skin surface is on average at a similar distance from the light source compared to the work surface. Therefore, the dose (or energy density) reached by the person's skin surface per day (8 h exposure) is approximately 0.115 J / cm 2 (8mW*28800s*0.005*0.1).

[0222] Example - Lighting Troffer

[0223] Another example of a lighting troffer and its specific implementation details are provided below.

[0224] Fig.9A The visible light source and radiation source used in this example are shown. Fig.9AThe top of the SYLVANIA START PANEL 600 4000K G4" (EAN 5410288477794) is shown with the following specifications. The 596×65×596 mm panel is equipped with LEDs to produce visible light with a color temperature of 4000K and a luminous flux of 4200 lm. The panel operates at 230 volts and consumes 30 W of electrical power. There is a PMMA / PVA diffuser of about 1.5 mm thickness.

[0225] The lighting troffer is also equipped with 100 LEDs from Vishay (type VSMY98545) emitting infrared radiation. Fig.9A The bottom of the figure shows a picture of such an LED. The package is a high-power SMD with a lens. The dimensions are 3.85×3.85×2.24 (L×W×H, in mm). The peak wavelength is λp=850nm. The half-intensity angle is φ=45°.

[0226] The design goal is to have an optical power of at least 160 W peak at 850 nm to achieve 8 mW / cm in the desired spectrum NIR-A at a distance of about 2 m. 2 Power density, considering a half-intensity angle of 45°.

[0227] According to the data sheet of VSMY98545 (which can be found at https: / / www.vishay.com / doc?81223 ), each LED outputs about 800mW of optical power at 1A forward current, or about 1.89W of optical power at 2.5A forward current, and pulsed for 5ms with a 1% duty cycle (800mW times about 236%, derived from the datasheet). Thus, 100 such LEDs placed in a visible light lighting panel (behind its diffuser) would output a total of 189W, meeting the design target.

[0228] Fig. 9B The spectrum measured at a distance of 1 meter from the lighting dark light trough of this example in the center of the light emission direction is shown. The measurement was performed in a dark laboratory, where the background noise was measured separately and subtracted from the measured spectrum. The measurement was performed over 4 seconds, where the measured spectrum was averaged to ensure that a sufficiently large number of pulse cycles were included and the average light intensity of the pulsed part of the total spectrum was measured. The integrated power in the near-infrared part between 760-900nm is about 10% of the optical power of the visible light spectrum. This percentage matches the fact that the electrical power fed to the infrared LED is about 15% of the electrical power of the visible light panel, and the infrared LED has an electrical efficiency of about 40%, compared to the electrical efficiency of the visible light panel of about 60%. The ratio of the electrical power fed to the infrared LED to the electrical power lost to the visible light panel is calculated to be 2.0 (V F From the data sheet Figure 3)*2.5(A)*1%(duty cycle)*100(number of LEDs) / 30(W), which is 16.66%, close to 15%.

[0229] This example uses a spectrum from 760 to 900 nm at 4.6 J / cm per 8 hours. 2 The average dose (fluence) irradiates its user surface at a distance of 2 meters, assuming a light output of 160W (lower than 189W due to diffuser losses) distributed over the spherical surface area of ​​a 45° 3D cone at a distance of 2m from the lighting troffer.

[0230] It should be noted that the above examples and variations are not limiting.

[0231] In summary, the present disclosure provides at least a lighting device, a lighting method and a lamp for general lighting, a retrofit bulb for general lighting, a retrofit lamp tube for general lighting and a lighting fixture for general lighting. By precisely pulsing the radiation source, an appropriate and beneficial amount of radiation in a predetermined spectrum can be provided at a reasonable amount of power consumption. Combining such a radiation source into a general lighting device can greatly expand its use and transform it into an easy-to-use general lighting source with medical benefits. Pulsing the radiation source can also help prevent overdose if the user is exposed to radiation in a predetermined spectrum for an extended period of time (such as more than 20 minutes).

[0232] The above description is intended to be illustrative rather than limiting. It will be apparent to those skilled in the art that alternative and equivalent embodiments of the invention may be conceived and simplified to practice without departing from the scope of the claims set forth below.

[0233] Reference Mark List

[0234] Lighting

[0235] 1b Lighting device

[0236] lc lighting device

[0237] 10 Radiation Source

[0238] 11 Light Source

[0239] 12 Driver Circuit

[0240] 13. Driver Circuit

[0241] 14 Sensors

[0242] 100 Radiation

[0243] 101 First drive current

[0244] 110 Visible light

[0245] 111 Second drive current

[0246] 141 Input

[0247] 20 users

[0248] 2a (modified) bulb

[0249] 2b (Retrofit) lamp

[0250] 2c Light

[0251] 2d lighting fixtures

[0252] 30 Curve

[0253] 31 Curve

[0254] 32 Curve

[0255] 33 Curve

[0256] 40 Curve

[0257] 41 Curve

[0258] 7 Linear Lights

[0259] 70 LED

[0260] 71 LED

Claims

1. A lighting device for general lighting, include: A light source (11), the light source being suitable for emitting visible light (110) suitable for general lighting, the visible light being white light; A radiation source (10) adapted to emit radiation (100) in a predetermined spectrum, wherein the predetermined spectrum is in the range of 760-1400 nm; as well as A driver circuit (12), the driver circuit being adapted to provide a first drive current (101), the first drive current being pulsed; wherein the lighting device is adapted to provide the first driving current (101) to the radiation source (10) instead of to the light source (11); and Wherein, in use, the light source (11) is configured to emit at least 250 lumens at the same time as the radiation source (10) emits the radiation (100).

2. The lighting device according to claim 1, in, The light source is adapted to emit white light having a color point in a CIE XYZ color space, wherein the color point is less than 10 color matching standard deviations from a black body line in the color space.

3. The lighting device according to claim 1 or 2, in, The lighting device is suitable for providing a second driving current (111) different from the first driving current to the light source (11), wherein the second driving current is a direct current, an alternating current, or a pulse width modulated current, and the pulse frequency of the pulse width modulated current is in the range of 20,000 Hz to 300,000 Hz.

4. The lighting device according to claim 3, in, The driver circuit is a first driver circuit (12), and wherein the lighting device further comprises a second driver circuit (13) adapted to provide the second drive current.

5. The lighting device according to claim 1 or 2, in, The pulse duration of the pulse of the first drive current (101) is in the range of 0.05-500 ms.

6. The lighting device according to claim 1 or 2, in, The pulse frequency of the first driving current (101) is in the range of 0.01-10000 Hz.

7. The lighting device according to claim 1 or 2, in, The duty cycle of the first driving current (101) is no greater than 20%.

8. The lighting device according to claim 1 or 2, in, The radiation source (10) is suitable for operating at an enhanced allowable drive current; or wherein at least one of a pulse duration, a pulse frequency and a duty cycle of the first drive current (101) is selected so that the first drive current (101) can drive the radiation source (10) at the enhanced allowable drive current.

9. The lighting device according to claim 1 or 2, in, The predetermined spectrum does not include the visible spectrum.

10. The lighting device according to claim 1 or 2, in, The predetermined spectrum is in the range of 800-1100 nm.

11. The lighting device according to claim 1 or 2, in, The peak emission power of the radiation emitted by the radiation source (10) excited by the pulsed first driving current (101) is at least 25W.

12. The lighting device according to claim 1 or 2, in, The peak emission power of the radiation source (10) receiving the pulsed first drive current (101) is such that it can be measured at a common average distance of 0.2 to 5 meters from the radiation source. 2 power density.

13. The lighting device according to claim 1 or 2, in, The radiation source (10) receiving a pulsed first drive current (101) is configured to deliver 0.01-5 J / cm2 measured at a common average distance from the radiation source. 2 A dose of , wherein the common average distance from the radiation source is between 0.2m and 5m.

14. The lighting device according to claim 1 or 2, in, The radiation source (10) in use consumes less than 50 WRMS.

15. The lighting device according to claim 1 or 2, in, The radiation source (10) comprises a solid-state device.

16. The lighting device according to claim 1 or 2, in, The lighting device is suitable for generating visible light (110) from the light source (11) having a luminous flux, wherein the visible light does not have a flicker percentage greater than 40% when the light source is in use.

17. The lighting device according to claim 1 or 2, in, The correlated color temperature of the visible light (110) from the light source (11) is in the range of 1700-6500K.

18. The lighting device according to claim 1 or 2, in, When the lighting device is in use, the ratio of the electric power consumed by the radiation source (10) to the electric power consumed by the light source (11) is no greater than 50%.

19. The lighting device according to claim 2, in, The color point is less than 8 color matching standard deviations away from a black body line in the color space.

20. The lighting device according to claim 1 or 2, in, The driver circuit is adapted to modify the first drive current (101) in response to an input to the driver circuit.

21. A lighting method, include: Providing a light source (11), the light source is suitable for emitting visible light (110) suitable for general lighting, the visible light being white light; Providing a radiation source (10) adapted to emit radiation (100) in a predetermined spectrum, wherein the predetermined spectrum is in the range of 760-1400 nm; supplying a pulsed first drive current (101) to the radiation source (10) so as to generate the radiation (100) in the predetermined spectrum; wherein the first driving current (101) is not supplied to the light source; and Wherein, in use, the light source (11) is configured to emit at least 250 lumens at the same time as the radiation source (10) emits the radiation (100).

22. A lighting device, include: A light source (11), the light source being capable of emitting visible light (110), the visible light being white light; a radiation source (10) capable of emitting radiation (100) in a predetermined spectrum, wherein the predetermined spectrum is in the range of 760-1400 nm; and A driver circuit (12), the driver circuit being adapted to provide a first drive current (101), the first drive current being pulsed; The lighting device is suitable for providing the first driving current (101) to the radiation source (10) instead of to the light source (11); and Wherein, in use, the light source (11) is configured to emit at least 250 lumens at the same time as the radiation source (10) emits the radiation (100).

23. A lamp (2c) for general lighting, comprising the lighting device according to any one of claims 1 to 20.

24. A retrofit bulb (2a) for general lighting, comprising the lighting device according to any one of claims 1 to 20.

25. A retrofit lamp tube (2b) for general lighting, comprising the lighting device according to any one of claims 1 to 20.

26. A lighting fixture (2d) for general lighting, comprising the lighting device according to any one of claims 1 to 20.

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