EA039957B1 - LED LIGHT SOURCE WITH SUNLIGHT CHARACTER TO IMPROVE COGNITIVE PERFORMANCE - Google Patents

Description

Technical field

An LED source that stimulates human cognitive activity and simulates sunlight.

The current state of the art

Lighting is considered one of the most important factors affecting the human circadian system. With the development of industry and technology, humanity artificially lengthens the day, especially during the winter months. We go to bed late at night or work evening shifts that require us to be absolutely alert. However, most of us at home or in the office use inappropriate lighting that does not stimulate us when we need it.

The biological clock, or central oscillator that controls circadian rhythms and resides in the suprachiasmatic nuclei (SCN), is affected by light indirectly through the retina. Thus, the eye, in addition to vision, transmits information about light. The pineal gland synthesizes the neurohormone melatonin, which in humans is used as a time indicator to synchronize and stabilize circadian rhythms and the cyclic alternation of sleep and wakefulness. SCN, using melatonin receptors, receive feedback on the amount of melatonin that circulates in the body. It has been proven that not all components of light affect us in the same way. Blue light with a wavelength of 460-480 nm has a stimulating effect, while red light with a wavelength of 610-700 nm calms and relaxes, its appearance is only desirable at night, when it is time to go to bed and productivity is not required. Blue light is certainly important, however, it can disrupt circadian rhythms, affect neuroendocrine systems and become one of the causes of the development of diseases of civilization. As a general rule, the higher the color temperature (CCT), the more blue is contained in the light. Indeed, in the case of blue light, stimulation with a significantly lower light intensity is necessary to achieve the desired effect than in the case of white light. A twenty-minute stimulation with bright white light results in the activation of the same areas of the brain as the same stimulation with blue light with an intensity 100 times lower.

Blue light serves as a modulator of many functions, including attention, arousal, reaction time, work productivity, and mood. The procognitive (cognitive) effect of light is transmitted through thalamocortical projections, the brainstem and ascending neurons of the reticular activation system. Improvements in attention following evening exposure to blue light have been shown to persist into the next day. In addition to attention, blue light also affects more complex cognitive activities. Blue LEDs have been proven to have a significant effect on the ability of visual space to rotate objects in 3D.

The effects of blue light on cognition have been compared to those of caffeine. Blue light and caffeine have also been tested and compared in a real-world driving situation at night on the motorway. Volunteers on a 400 km track received 200 mg of caffeine or had a blue light with a wavelength of 468 nm on their dashboard all the time. Decaffeinated coffee alternative was used as control. Both test groups were more effective than the decaf group. (SHMOTEK, Michal and Col. Effects of blue light on the circadian system, sleep, and cognitive performance. National Institute of Mental Health).

Patent document CN 106994209 describes an LED lighting for treating depression which includes blue light emitting LED chips and white light emitting LED chips, wherein the ratio of blue LED chips to the number of white LED chips is 0.03:0.25.

There are many manufacturers of LED lighting. Seoul Semiconductor introduced the world to the SunLike lamp, which emits a light spectrum similar to daylight. Blue wavelengths have been eliminated by adding purple LED chips. Objects illuminated by this light appear as if illuminated by the sun during daytime. A classic LED with a phosphor with the addition of a blue, yellow and red chip has a large roll-off in the turquoise and red ranges. Therefore, this light is not suitable for cognitive activities, and it also has a very poor color rendering index value. The lamp with the HUE designation from Philips has a high color temperature (up to 6000 K), but its light spectrum is similar to that of the above lamp, i.e. it has a large rolloff in the turquoise range and is therefore not suitable for stimulating cognitive activity. Also often combined are LEDs consisting of red, green and blue chips, the so-called RGB LEDs. White light appears as a superposition of all parts of the visible spectrum, namely red, blue and green. With these combined diodes, a wide range of color spectrum can be achieved. However, the light spectrum created by color mixing has a rolloff from turquoise to green and also in the orange range, so there is no stimulation of cognitive activity either.

The essence of the technical solution

A unique source of LED lighting was created, which increases cognitive activity and, by its nature, in the biologically favorable radiation range by 90%

- 1 039957 chen to sunlight. Cognitive activity of a person is very desirable during the working regime or during any activity when it is necessary to feel cheerful or even to concentrate as much as possible and perform mental work, such as, for example, during study, solving complex problems, longer concentration, etc.

The sunlight character LED light source for cognitive enhancement consists of at least three types of LED chips: white chips, which are blue chips with phosphor overlay, monochrome blue LED chips, and monochrome turquoise LED chips. The spectrum thus composed has a very specific spectral composition and represents the best part of sunlight in the biologically favorable range of 460 to 660 nm. Shorter wavelengths of ultraviolet radiation no longer affect the imaging function and better visibility, on the contrary, they dazzle a person and their light is unpleasant. Therefore, sunglasses are often used outdoors in the summer. In addition, electromagnetic radiation in the range from 380 to 450 nm is considered dangerous blue light, and the human eye does not even have receptors for it. On the other side of the light spectrum, wavelengths of 740nm and above in the infrared range also do not contribute to the best display accuracy, since they only warm the interior, which is unnecessary and often even undesirable.

This LED light source is characterized by the distribution of light energy intensity in the range from 460 to 660 nm with a maximum difference of 25% at the maximum and minimum of a given light spectrum in this range. Hence, with minimized light intensity decays in individual spectral lengths.

Thus, this spectrum is continuous up to at least 75% of the value of its maximum, when it is the colors of the spectrum of the minimum energy source, which are these minima of the spectrum, that reach 75% of the emission intensity and above.

The spectrum of the LED light source approaches the spectrum of sunlight in the balance of the maximum and minimum distribution of light energy depending on the wavelength in the biologically favorable range from 460 to 660 nm to 91%.

The advantage is that in order to supplement the intensity of the yellow-green range of the emitted spectrum for maximum approximation to the spectrum of sunlight, an LED chip with radiation in the yellow-green range of at least 500-580 nm is also added. The light spectrum of the LED light source with the addition of intensity in the yellow-green range is characterized by the distribution of light energy in the range from 460 to 660 nm with a maximum difference between the maximum and minimum of this light spectrum in this range of 15%. Those. with minimized drops in light intensity in individual spectral lengths, when the distributed light energy between the wavelengths of the radiation differs by no more than 15%.

Thus, this spectrum is continuous up to at least 85% of the value of its maximum, when it is the spectral colors of the source with the lowest energy, which are given by the minima of the spectrum, that reach 85% of the emission intensity and above.

The spectrum of the LED light source approaches the spectrum emitted by the sun in terms of the balance of the maximum and minimum distribution of light energy depending on the wavelength in the biologically favorable range from 460 to 660 nm up to 98%.

The advantage of the new LED light sources with the nature of sunlight is that they consist of four light sources with a certain mutual distribution of light energy, which is given by the power and light power of the individual chips. The LED light source works as a single unit. When replacing even one type of chip with another, the LED light source will be unbalanced, and it will no longer produce the required integral parameters. The basic ratio of the light output of the individual LED light sources in relation to a white LED chip with a color temperature of 3800 to 4200 K and a CRI of 90 to 98 must always be respected.

The LED light source is set to a white LED light source with a color temperature between 3800K and 4200K, with an advantage of 4000K. If a white light source with a lower color temperature, such as 2700K, is used as a warm white light source that simulates light At sunset, the system will lack light energy in the blue range, in terms of color, the LED light source will lose its correct neutrality and shift towards the green hue of the emitted light. Conversely, when using a white light source with a higher color temperature, such as 5500 K, which is used in flashes during photography, the system will not have enough light energy in the red range, in terms of color, the LED light source will again lose proper neutrality and will shift towards the blue tint of the emitted light.

Each LED chip is made up of semiconductors that form alloys. A typical semiconductor used for blue LEDs is preferably a multiple quantum well Nitrid Indium-Galium (InGaN), Zinc Selenide (ZnSe) or Silicon carbide (SiC) semiconductor, and a semiconductor for turquoise LEDs is again a multiple quantum well semiconductor

- 2 039957 well InGaN only with a higher In content when the light spectrum shifts towards the turquoise range. The white LED chip used consisted of a blue phosphor overlay LED chip emitting a ribbon spectrum in the wavelength range from 420 to 780 nm.

The LED light source, which, in addition to blue and turquoise LED chips, is enriched with a yellow-green spectrum component using PC lime LED chips, not only supports human cognitive activity, but also simulates the light spectrum emitted by the sun with an even higher balance of individual color components of the spectrum in the required range, i.e. from 460 to 660 nm, which is an efficient simulation of sunlight that makes sense for quality visibility.

Models of LED lighting sources with the nature of sunlight include:

white chip - color temperature 3800-4200 K, CRI 90-98, emitted spectrum with a wavelength of 420 to 780 nm, with a share of 78 to 85% of the total radiated energy or 82 to 87% of the total luminous flux, turquoise monochrome LED chip with a maximum emission intensity of 475±5 nm with a share of 3 to 7% of the total radiated energy or 4 to 7% of the total luminous flux of the source, a blue monochrome LED chip with a maximum emission intensity of 495±5 nm with a share of 3 to 7% of the total radiated energy, and from 1 to 4% of the total luminous flux of the source, since this is the limit of the visible range, and not all electromagnetic radiation is visible light.

The advantage is the inclusion of a yellow-green PC lime LED chip with a share of 6 to 9% of the total radiated energy or 10 to 15% of the total luminous flux of the source.

The ideal ratio of luminous power in lm of individual light sources of LED chips white LED : yellow-green LED PC lime : turquoise LED : blue LED is 100:9:6:3.

The advantage of this lighting is the combination of a white LED chip, 3800 to 4200 K, CRI 90 to 98, which has a continuous spectrum with a typical rolloff in the range of 460 to 530 nm, which is caused by stimulating the blue LED chip at about 450 nm and shifting the blue light by passing through a phosphor in the yellow-green-red range with a wavelength of 520 to 740 nm, a monochrome blue LED chip with a maximum emission of 475 ± 5 nm, a monochrome turquoise LED chip with a maximum emission of 495 ± nm, and as an advantage with yellow-green PC lime LED chip, which has a continuous spectrum caused by stimulating the blue LED chip at about 420 nm and shifting the blue light through the phosphor into the yellow-green range with a wavelength of 500 to 650 nm.

In this case, the mutual ratio of the luminous power or luminous efficiency of individual LED chips and their mutual representation in one lamp is of absolutely fundamental importance in order to obtain a balanced light spectrum in the range from 460 to 660 nm. By this is meant the maximum balance of all the peaks of the spectrum of the individual LED chips of the source in the same intensity.

For the demonstration, LED chips of the following parameters were selected:

1. Today's best white LED chip with a color temperature of 4000K and a color accuracy of 98, with a light output of 70 lm/W and a power of 1.395 W, with a representation in the total radiated power of 51.2%.

2. Blue monochrome LED chip, with a maximum emission wavelength of 475 nm, with a light output of 29.45 lm/W and a power of 1.46 W, with a representation in the total emitted power of 20%.

3. Turquoise monochrome LED chip, with a maximum emission wavelength of 495 nm, with a light output of 64.10 lm/W and a power of 1.56 W, with a representation in the total radiated power of 20%.

4. Yellow-green PC-lime LED chip with a continuous emission spectrum in the range of 500 to 600 nm, with a light output of 96 lm / W and a power of 1.395 W, with a representation in the total radiated power of 8.8%.

The cognitive LED light source includes at least one white LED chip, at least one blue LED chip, and at least one turquoise LED chip. The advantage is the use of different chips depending on the size and required power of the LED light source. It is also an advantage to install chips on a printed circuit board, which forms a section, the technological length of the printed circuit board section with the advantage is from 5 to 8 cm. The sections of the printed circuit boards are connected by soldering after the edges are applied. The connected printed circuit boards form a light strip of arbitrary length. Each section includes several LED chips connected in series, individual sections are connected in parallel in a tape.

The cognitive source includes LED chips with a precisely balanced power ratio of white LED chips with blue and turquoise LED chips, when the ratio between white LED chips : blue LED chips : turquoise LED chips is advantageously 1 : 0.03 to 0, 05 : 0.03 to 0.05. The cognitive LED light source has arbitrary power ratios of individual LED chips, when LED chips with lower power are installed in larger numbers to compensate for their lower light intensity to provide the required power to the given LED chips.

This unique relationship found for the Cognitive LED Light Source surprisingly fills the entire emitted spectrum of the Cognitive LED Light Source to the level of both light peaks of the whitest LED chip in the blue-green tint range, i.e. with wavelengths of light in the blue and turquoise range. As a result, the light emitted light spectrum becomes continuous up to at least 75% of the light intensity. This specific addition of blue and turquoise monochrome LED chips causes/ensures a great similarity of the emitted light to sunlight, when the main equalization of the light intensity in the blue-green tint range and in the spectral range of light from 460 to 660 nm occurs for an equalization of 80% of the light intensity sun, as shown in Fig. 1.

The whole system of the cognitive LED light source is adjusted so that the emitted light emission of the white LED chips is supplemented with 4.5 to 6% blue and turquoise light emission, with the advantage of the corresponding emission intensity. This will ensure that the intensity of the radiation in the blue-green range with respect to the red range is almost equal to the level of sunlight. The created combined light emission of the cognitive LED light source has a CRI of 98 and a color temperature of 4000 to 4700 K, sunlight has a color temperature of 4982 L and a CRI of 99.5.

The advantage of a light source for cognitive activity is the use of at least two light strips. White strip, which is equipped with white LED chips only. A blue strip that includes monochrome blue LED chips with monochrome turquoise LED chips with the same power and the power of one white LED chip with a lead of 0.17 W. The second LED strip with a advantage alternates between monochrome blue LED chips and monochrome turquoise LED chips with the same power , moreover, blue with turquoise LED chips with a 1:1 advantage. The luminous power of one blue or turquoise chip with a lead is 0.09 W.

The length of the LED strip and the number of LED chips can be arbitrary, but the ratio of the light output of the white LED chips: (blue + turquoise) 1 : 0.03 to 0.05 must be observed. The luminous power of blue and turquoise LED chips is advantageously 4.5 to 6% of the luminous power of white LED chips, or the power consumption of blue and turquoise LED chips is 13 to 15% of the wattage of white LED chips. It was ensured that the white LED chips themselves had a power consumption of 85 to 87% of the total power consumption, and after turning on the blue-turquoise strip, the power consumption increased by 13-15%.

The cognitive LED light source advantageously includes at least two light strips consisting of a printed circuit board including white, blue and turquoise chips connected to a ballast that is connected to a power supply. Behind the ballast, a dimmer is advantageously connected to control the supplied current, which serves to reduce the intensity of the radiation of individual LED strips.

LED light source, which advantageously also includes yellow-green LED chips PC lime includes LED chips connected in two channels, where the 1st channel includes from 20 to 80 white LED chips, and the 2nd channel includes from one to eight groups of blue-turquoise-yellow-green LED chips, where one group of LED chips includes one blue LED chip, one turquoise LED chip and one green-yellow PC lime LED chip. The blue-turquoise-yellow-green LED chip group also advantageously includes one to four white LED chips.

With advantage, the 1st channel includes 40 to 60 white LED chips, and the 2nd channel includes four groups of blue-turquoise-yellow-green LED chips.

With advantage, the 1st channel includes 48 white LED chips, and the 2nd channel includes four groups of blue-turquoise-yellow-green LED chips and four white LED chips.

The LED light source, which also advantageously includes yellow-green PC lime LED chips, also advantageously contains three rows of chips, when the first and third rows include only white LED chips from the 1st channel, and the second row includes the chips from the 2nd channel , i.e., groups of blue-turquoise-yellow-green LED chips interleaved with a white LED chip.

Overview of drawings in drawings

Fig. 1 - light spectrum of daytime sunlight.

- 4 039957

Fig. 2 - light spectrum of a classic LED with a color temperature of 4000 K with a CRI of 80.

Fig. 3 - light spectrum of a white LED chip with a color temperature of 3957 K and CRI 98.

Fig. 4 - light spectrum of a strip with white LED chips and a color temperature of 3806 K and a CRI of 97.8.

Fig. 5 is a diagram of the electrical connection of a light source for improving cognitive activity.

Fig. 6 is a drawing of a printed circuit board with LED chips according to example 1.

Fig. 7 - light spectrum of the LED strip with monochrome blue and turquoise LED chips.

Fig. 8 is a spectrophotometric spectrum emitted by a cognitive LED light source in accordance with example 4.

Fig. 9 is a spectrophotometric spectrum emitted by a cognitive LED light source in accordance with example 2.

Fig. 10 is a detail of the spectrum of FIG. 9.

Fig. 11 is a spectrophotometric spectrum emitted by a cognitive LED light source in accordance with example 1.

Fig. 12 - detail of the spectrum of fig. eleven.

Fig. 13 - LED strip equipped with LED chips in two channels, in accordance with example 5.

Fig. 14 - 14A: light spectrum emitted by the tape, in accordance with example 5, with only the 2nd channel turned on, when the passing current was 350 mA,

B: the light spectrum emitted by the tape, in accordance with example 5, when only the 2nd channel is turned on, when the passing current was 500 mA,

C: light spectrum emitted by the tape, according to example 5, when only the 2nd channel is turned on, when the passing current was 600 mA,

D: light spectrum emitted by the tape according to example 5, when only the 2nd channel is switched on, when the passing current was 700 mA.

Fig. 15 shows the spectrum emitted by the LED light source according to Example 5.

Fig. 16 - comparison of spectra of light sources,

16A: spectrum of white LED chip with color temperature 4000K and CRI 90,

16V: spectrum emitted by the LED light source according to example 1, cognitive light source,

16C: spectrum emitted by the LED light source according to example 5, with the nature of sunlight.

Fig. 17 is a graph of individual spectra of all light sources of the used LED chips, A is a white LED chip 4000 K, B is a blue LED chip, C is a turquoise LED chip, D is a PC lime LED chip, E is an LED light source with a sunlight character according to example 5.

Fig. 18 - voltage characteristics of LED chips depending on the passing current.

Fig. 19 - the results of tests of cognitive activity - the average value of the group + the average deviation. An asterisk indicates a statistically significant difference according to example 7.

Fig. 20 - the average value of the subjective assessment of the test (GNP, n=51) and control (GULZ, n=53) groups in accordance with example 7.

Fig. 21 is a circuit board drawing of an LED light source manufactured according to Example 5 equipped with LED chips.

Fig. 22 is a circuit board diagram of an LED light source manufactured according to Example 5 equipped with LED chips.

Fig. 23 is a wiring diagram for an LED light source made in accordance with example 5.

Fig. 24 is a plot of individual spectra of all light sources of the LED chips used, A is a white 2700 LED chip, B is a blue LED chip, C is a turquoise LED chip, D is a PC lime LED chip, E is an LED light source according to example 6.

Execution examples

Example 1 - two LED strips, blue and turquoise LED chips with the same light output.

The white LED chip consisted of a blue LED chip with an InGaN semiconductor composition, overlaid with a phosphor. The advantage was the use of phosphors with the commercial name ZYP630G3 emitting light with a maximum wavelength of 628 nm and ZYP555G3 emitting light with a maximum wavelength of 555 nm, which were dispersed in a silicone housing that was put on top of a blue LED. The LED housing can have different geometry, the advantage was the inclination of the wall angle of the LED housing by 20° to the plane.

Cognitive LED lighting was created with two meter LED strips

- 5 039957 and 6, which consisted of printed circuit boards equipped with LED chips, with the strips connected to a ballast 9, which were connected to a current source 10. The white light strip 5 was equipped with 240 white LED chips 1 arranged in two rows, wherein, one circuit board 4 with a length of 5 cm was equipped with 12 white LED chips 1 The white LED chip 1 consisted of a blue LED chip with InGaN semiconductor composition, overlaid with phosphor marked ZYP555G3 and ZYP63063 in a ratio of 1:2. The emitted light from the white LED chip 1 was a continuous spectrum tape with a wavelength of 380 to 700 nm with a color temperature of 3957 K and a CRI of 98. The white LED tape 5 with white LED chips 1 had a light power of 41 W/m. The 1m blue and turquoise chip 6 LED strip light strip was equipped with 55 monochrome blue LED chips 2 with InGaN semiconductor composition with a maximum emission of 475nm and 55 monochrome turquoise LED chips 3 with InGaN semiconductor composition with a maximum emission of 495nm. One circuit board 4 7.2 cm long was equipped with four blue LED chips 2 and four turquoise LED chips 3, which were mutually interleaved one after the other. The LED strip for blue and turquoise chips 6 had a power of 3 W/m. The brightness ratio of white LED chips: blue: turquoise was 1:0.3:0.3. The chip ratio was 4:1:1.

The characteristic parameters of this source were measured by UPRtek handheld spectrometer, the emitted light had a CRI of 89 with a color temperature of 4603 and the spectrum of the emitted light was in the range from 420 to 760 nm, the calculated emission area from the range from 460 to 650 nm was 80% of the intensity of sunlight , as shown in FIG. 10.

The consumption of cognitive LED lighting was also measured, which was 80.2 W.

Example 2 - two LED strips, blue and turquoise LED chips with different light output.

Educational LED lighting was created with two meter LED strips, 5 white chip LED strip and 6 blue and turquoise chip LED strip, which consisted of printed circuit boards equipped with LED chips, moreover, the strips were connected to a ballast 9, which were connected to a power source TO). The white chip LED strip 5 was equipped with 240 white LED chips 1 in two rows, whereby one PCB 4 5 cm long was equipped with 12 white LED chips 1 The white LED chip 1 consisted of a blue LED chip with a ZnS designation ZYP555G3 and ZYP63063 in a ratio of 1:2. The resulting emitted light from the white LED chip 1 was a continuous spectrum of a tape with wavelengths from 380 to 700 nm with a color temperature of 4000 K and one white LED chip 1 with a power of 0.17 W, i.e., the power of the entire meter white tape was 41 W/m.

6 blue and turquoise chips LED strip 1m length was equipped with 110 monochrome blue LED chips 2 with InGaN semiconductor composition with maximum emission of 475nm with light power of 4mW and 55 monochrome turquoise LED chips 3 with semiconductor composition with maximum emission of 495nm with light power 7 mW, i.e., the entire meter LED strip of blue and turquoise chips 6 had a power of 825 mW/m. One PCB 4, 7.2 cm long, was equipped with six blue LED chips 2 and two turquoise LED chips 3. The color LED chips always alternated: 2 blue and 1 turquoise. This source was measured with a UPRtek handheld spectrometer, the characteristic parameters of the emitted light had a CRI of 91.3 with a color temperature of 4397 and the spectrum of the emitted light was in the range from 420 to 760 nm, the calculated emission area from the range from 460 to 650 nm was 78 % sunlight intensity as shown in FIG. 10.

The consumption of cognitive LED lighting was also measured, which was 77.2 W.

Example 3 - three LED strips, blue and turquoise LED chips with different light outputs.

Three meter LED strip, 5 white chip LED strip, blue chip LED strip and turquoise chip LED strip were created, on which the LED chips were placed. The white chip LED strip 5 was equipped with 240 white LED chips 1, whereby one circuit board 4 with a length of 5 cm was equipped with 12 white LED chips 1 arranged one after the other. The white LED chip 1 consisted of a blue LED chip with a ZnS semiconductor composition, overlaid with a phosphor designated ZYP555G3 and ZYP63063 at a ratio of 1:2. The color temperature of the finally emitted light from the white LED chip 1 was 4000 K and the wavelength was 380 to 700 nm. The power of one white LED chip was 0.17 W, i.e., the power of the entire meter white strip was 41 W/m.

The 1m long blue chip LED strip was equipped with 219 monochrome blue LED chips 2 with InGaN semiconductor composition with a maximum emission of 475nm with a total light power of 1.5W/m, with a single chip power of 7mW. The 1m long turquoise LED chip LED strip was equipped with 110 monochrome turquoise LED chips 3 and

- 6 039957 semiconductor composition InGaN with a maximum emission of 495 nm and a total light power of 1.4 W/m, with a single chip power of 12 mW. The characteristic parameters of this source were measured using a UPRtek handheld spectrometer, the emitted light had a CRI of 90 with a color temperature of 4650 and the spectrum of the emitted light was in the range from 420 to 760 nm, the calculated emission area from the range from 460 to 650 nm was 80% of the light sunlight intensity.

The power consumption of cognitive LED lighting was also measured, which was 80 W.

Example 4 - three chips.

The round light source was equipped with three LED chips, one 2W white LED chip with a color temperature of 3957K and CRI 98 of the continuous band of visible light with a wavelength from 440nm to 700nm, one 60mW blue LED chip and a 60mW turquoise LED chip. . The white LED chip emitted a continuous ribbon spectrum of visible light with a wavelength of 440 nm to 700 nm and a CCT color temperature of 3800 to 4200 K, as well as a CRI of 98. The blue LED chip was formed by InGaN with a maximum emission of 475 nm, and the turquoise LED chip InGaN was formed with a maximum emission of 495 nm. This source was characterized by UPRtek handheld spectrometer, the emitted light had a CRI of 89.5 with a color temperature of 4810 and the spectrum of the emitted light was in the range from 420 to 760 nm, the calculated emission area from the range from 460 to 650 nm created 81% of the intensity sunlight, as shown in Fig. 8.

Example 5

An LED light source was created, which contained one LED strip with three rows, whereby the first and third rows were equipped with 24 white LED chips, i.e., a total of 48 white LED chips, and connected to the 1st channel in parallel through 12 chips, connected in series, with a color temperature of 4000 K and a CRI of 98, and the center row was equipped with 4 blue monochrome LED chips with a maximum emission of 473 to 475 nm, 4 turquoise monochrome LED chips with a maximum emission of 495 nm, 4 PC Lime LED chips with a maximum 520 nm stimulated at 420 nm, as well as 12 white LED chips and connected to the 2nd channel in parallel through 12 chips connected in series, with the central row being created by white LED chips alternating with blue, turquoise and PC lime LED chips, i.e., white, blue, white, turquoise, white, PC lime, white, blue, etc.

The characteristics of the individual chips were as follows:

white LED chip power: 0.31W per chip in 1st channel including 48 chips total 15.1W and 0.93W per chip in 2nd channel including 12 chips total 11.1W .

The sum of the total power of the white chips: 26.2 W, the light output: 70 lm/W, the proportion of the total light energy: 51.2% blue monochrome LED chip with a maximum emission of 475 nm, the power: 0.35 W per chip per 2nd channel, including 4 chips total 1.4 W, light output: 29.45 lm/W, proportion of total light energy: 20%, turquoise monochrome LED chip with a maximum output of 495 nm, power: 0.38 W per chip in the 2nd channel, including 4 chips total 1.5 W, light output: 64.1 lm/W, share of total light energy: 20%, PC Lime LED chips with a maximum output of 520 nm, power : 0.78 W per chip in the 2nd channel including 4 chips, total 3.1 W, light output: 96 lm/W, share of total light energy: 8.8%.

The total source power is 32.2 W, 72 LED chips.

Example 6

An LED light source was created, which included one LED strip with three rows, whereby the first and third rows were equipped with 24 white LED chips, i.e., a total of 48 white LED chips, and connected to the 1st channel in parallel through 12 chips, connected in series, with a color temperature of 2700 K and a CRI of 98, and the center row was equipped with 4 blue monochrome LED chips with a maximum emission of 473 to 475 nm, 4 turquoise monochrome LED chips with a maximum emission of 495 nm, 4 PC Lime LED chips with a maximum 520 nm stimulated at 420 nm and 12 white LED chips with a color temperature of 2700 K and CRI 98, and connected to the 2nd channel in parallel through 12 chips connected in series, with the central row being created by white LED chips laid alternately blue, turquoise and LED PC lime chip, i.e. white, blue, white, turquoise, white, PC lime, white, blue, etc. The spectrum of this source has been measured and judged to be unsuitable for use as an LED light source with the nature of sunlight.

- 7 039957 due to the low emission intensity in the blue range and the lack of spectrum balance in the required biologically favorable range from 460 to 660 nm.

Example 7

In the Prague Gymnasium Gymnazia Na Prazacce (GNP), part of the building was equipped with LED lighting technology to improve cognitive performance in accordance with example 1. Thanks to the blue component of the lighting spectrum, especially the cognitive activity of students was supported in the classrooms. Other monitored parameters were, for example, concentration, attention, reaction speed, memorization and thinking speed, recall, physical performance, visual comfort and subjective satisfaction of students and teachers - a summary of all subjective parameters is shown in Figure 20. The experiment was carried out in two evaluation time periods - before and after installation of LED lighting. The Liberec Castle Gymnasium (GULZ) was chosen as a control group. The experiment took place simultaneously in two objects (GNP and GULZ). The experiment was evaluated using two sets of specially designed psychological tests, where one set of tests was aimed at objective parameters resulting from the ability of students to learn, and the other set of psychological tests was aimed at the subjective perception of LED lighting by students and teachers. The results indicate that students exposed to LED lighting according to example 1 demonstrate better learning outcomes, better health - assessment parameters also included monitoring absence due to illness and waking up, as well as greater satisfaction compared to control groups of students. Individual experiments describe the following examples. All measurements were performed using a spectrophotometer.

Example 7A. Illumination measurement.

By measuring the illumination on the desktop, the actual lighting conditions in the classrooms during the training were recorded. A certain intensity of illumination was comparable in all classrooms in both gymnasiums where testing was carried out. The horizontal illumination of desks and teacher's desks with updated and standard lighting reaches approximately 800 1x and the light falling into the eyes of students (i.e. biologically effective light) is approximately 300-330 1x, depending on the position in the classroom and the direction of view.

Sufficient illumination of the surfaces was reflected in the evaluation of the legibility of the text on the board, which was comparable in the classrooms of the same size, very good. Although the illumination of surfaces in the classrooms was comparable, 25% of students from the control classrooms rated the spaces as too bright, while only 6% of students said so under the new lighting. The difference in score is statistically significant (T-test, n=104, p=0.01). The explanation for this phenomenon may lie in the better distribution and more balanced spectral composition of the new illumination.

Example 7B. Measurement of biological effectiveness.

Measurement of the spectral response showed that despite a comparable level of illumination, the new lighting reaches 0.47-0.36 W / m in the assessment of biological effectiveness according to Brainard, while the lighting in the control room is only about 0.25 to 0.20 W /m. This is possible thanks to a balanced spectral composition of light with a high content of the blue component of the spectrum, which is a key parameter for achieving the desired positive effect on cognition and perseverance, as well as good synchronization of the body's biological clock.

Example 7C. Objective assessment - tests of cognitive activity.

An objective assessment of the influence of light was carried out using tests of cognitive activity. The tests tested concentration and short-term memory. The first stage of testing, i.e., 3 months after the installation of lighting, reveals significantly better results in students who study in the morning in a classroom equipped with new cognitive lighting. These students made fewer mistakes in tests (T-test, n=104, p<0.05), their short-term memory was significantly better (Ttest, n=104, p<0.02) than that of students from regular classrooms. The test results are shown in Figure 19.

Example 7D Measurement of color rendering index Ra.

The new lighting also achieves a higher Ra color rendering index. Initially, all auditoriums were GNP, as well as monitored reference auditoriums in GULZ, lighting with Ra 60 was installed. This does not meet the requirement for indoor lighting for long-term occupancy, at least Ra 80 is required. The new lighting system reaches Ra 91, which is important not only because of the orientation of the gymnasium towards art education. This was probably reflected in the subjective assessment of the students, where there was a tendency to better assess the naturalness of the colors of the new lighting. If, under new lighting, 85% of respondents assess skin color as natural or relatively natural, then in the original it was only 69%. Mean subjective scores for the test (GNP, n=51) and control (GULZ, n=53) groups are shown in FIG. 20.

Example 7E. Energy saving.

New lighting has been installed in about half of the classrooms where it originally replaced

- 8 039957 installed fluorescent and conventional energy saving LED lighting. The measurement was carried out in the entire object. Despite a significant increase in lighting and, in particular, an improvement in the quality of lighting, about half of the premises of the gymnasium have not seen an increase in annual electricity consumption. On the contrary, in the last quarter of 2018 there was a slight decrease in consumption by 5%.

Example 7F. Psychological effect.

The newly installed auditorium lighting was subjectively rated as more pleasing compared to conventional lighting (t-test, n=104, p<0.01). While only 32% of students rated the lighting in the control rooms as pleasant or generally pleasant, in the newly installed lighting it was 53%.

List of related marks

- white LED chip;

- blue LED chip;

- turquoise LED chip;

- white tape printed circuit board;

- LED strip of white chips;

- LED strip of blue and turquoise chips;

- PCB LED strip blue and turquoise chips;

- dimmer;

- ballast;

- nutrition;

- yellow-green LED chip PC lime.

Application in industry

A light source that stimulates human cognitive activity is also suitable wherever greater concentration and attentiveness are required.

Claims (14)

CLAIM 1. An LED light source with the nature of sunlight to improve cognition with 90% compliance in the balance of the maximum and minimum distribution of light energy in the range from 460 to 660 nm, containing at least one white LED chip (1) emitting light with a wavelength from 380 to 700 nm, and at least one monochrome blue LED chip (2) emitting light with a wavelength of 470 to 480 nm, moreover, the LED chips are connected to an electric current source, characterized in that it also includes at least one monochrome turquoise LED chip (3) emitting light with a wavelength of 490 to 500 nm, a white LED chip has a color temperature of 3800 to 4200 K and a CRI of 90 to 98, while blue LED chips (2) and turquoise LED chips (3) each form 3 to 7% of the total radiant energy of the LED light source or the luminous flux of blue LED chips (2) account for 1 to 4% of the total light output output of the LED light source, and the luminous flux of the turquoise LED chips (3) is from 4 to 7% of the total luminous flux of the LED light source, while the main radiant energy and the main luminous flux are provided by white LED chips. 2. The source according to claim 1, characterized in that it includes at least one LED chip PC lime (11) with radiation in the yellow-green range with a wavelength of 500 to 650 nm with a share of 6 to 9% of total radiated energy or 10 to 15% of the total light power of the source. 3. Source according to claim 2, characterized in that the PC lime LED chip is formed by a blue chip (2) stimulated in the range of 420 ± 5 nm with a phosphor overlay. 4. Source according to claim 1, characterized in that the white LED chip (1) is formed by a blue LED chip (2) with a phosphor overlay. 5. Source according to claim 1, characterized in that the power ratio of blue LED chips (2) and turquoise LED chips (3) is 1:1. 6. Source according to claim 2, characterized in that the proportion of light power of blue LED chips (2):turquoise LED chips (3):PC lime LED chips is 1:2:3. 7. Source according to claim 2, characterized in that the total emission intensity of the LED light source is determined from 4.5 to 7% by blue LED chips (2), from 4.5 to 8% by turquoise LED chips (3), from 6 to 10% PC lime LED chips and 78 to 85% white LED chips. 8. Source according to claim 1, characterized in that the sum of the power of the blue LED chips (2) and the sum of the power of the turquoise LED chips (3) is each 5% of the sum of the power of the white LED chips (1). 9. Source according to claim 1, characterized in that four white LED chips (1), one blue LED chip (2) and one turquoise LED chip (3) are located on the printed circuit board (4, 7) times - 9 039957 measuring 1.25 cm. 10. The source according to claim 1, characterized in that four white LED chips (1), two blue LED chips (2) and one turquoise LED chip (3) are located on a printed circuit board (4, 7) with a size of 1.25 cm, moreover, the power of the blue LED chip (2) is 2 times less than that of the turquoise LED chip (3). 11. The source according to claim 1, characterized in that four white LED chips (1), one blue LED chip (2) and two turquoise LED chips (3) are located on a printed circuit board (4, 7) with a size of 1.25 cm, moreover, the power of the turquoise LED chip (3) is 2 times less than that of the blue LED chip (2). 12. Source according to claim 2, characterized in that the light power of the blue LED chip (2) is from 27 to 32 lm/W, the light power of the turquoise LED chip (3) is from 63 to 66 lm/W, the light power of the LED chip PC lime is 85 to 100 lm/W, and the light output of white LED chip is 70 to 90 lm/W. 13. The source according to claim 2, characterized in that it includes LED chips connected in two channels, and the 1st channel includes from 20 to 80 white LED chips and the 2nd channel includes from one to eight groups of blue-turquoise green LED chips, and one group of LED chips includes one blue LED chip, one turquoise LED chip and one PC lime LED chip. 14. The source according to claim 13, characterized in that the 1st channel includes from 40 to 60 white LED chips and the 2nd channel includes four groups of blue-turquoise-green LED chips.