JP2012221937A - Lighting device with led as light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain degradation of recognition and judgment of a human being due to fatigue of eye or sense of hearing, with the use of a white-color LED light source.SOLUTION: The lighting device has as a light source a white-color-light LED package consisting of blue-color LED elements, and phosphors emitting fluorescence of a wavelength longer than that of the blue-color LED elements, arranged at an emission side of light of those LED elements, and has a convergent lens arranged at an emission side of light of the white-color-light LED package. The device irradiates light that has a first peak originated in the blue-color LEDs from 420 nm to 450 nm, and a broad second peak from 600 nm to 680 nm, and at the same time, has a shoulder part formed within the range of 480 nm to 500 nm, not substantially increasing changes at appearance and disappearance of visual induction potential of a human being (F-VEP P100 wave) and/or delay of auditory induction potential (P 300 wave).

Description

  The present invention does not substantially increase the change in the appearance latency of the human visual induction potential (F-VEPP 100 waves) and / or the delay of the auditory induction potential (P300 waves) using an LED (light emitting diode) as a light source. The present invention relates to a lighting device that radiates light. Here, the appearance latency of the F-VEP P100 wave does not change, that is, the appearance latency of the F-VEP P100 wave does not become long or short, which means that eye fatigue is small, and the appearance latency of the P300 wave. Not delaying means that the decline in recognition / judgement through vision is low, that is, the shorter the delay in the appearance latency of the P300 wave is, the higher the recognition / judgement is.

  The present applicants based on a study of illumination and eye fatigue focused on visual evoked potential (VEP) used in clinical examinations of disorders and diseases in the ophthalmic field, and when eye fatigue occurs due to visual work, P100 in the VEP We found a phenomenon in which the appearance latency of the wave is delayed, and at the same time, the delay in the appearance latency of the P100 wave increases with the progress of eye fatigue. I found a fact that could be converted. And the present applicants etc. have proposed the illuminating device which irradiates the light which does not substantially delay the appearance latency of the P100 wave in human VEP based on these knowledge (for example, refer patent document 1). This illuminating device is an invention that irradiates light that does not easily cause eye fatigue, and by applying a DC voltage of 105 to 140% of the rated voltage to a xenon gas-filled incandescent bulb as its light source, the appearance of P100 waves in VEP The light source does not substantially delay the latency. Furthermore, examples of the light source include high color rendering fluorescent lamps such as a multi-wavelength light emitting fluorescent lamp and discharge lamps such as a xenon discharge lamp.

  Further, the present applicants and others have proposed an adrenocorticotropic hormone (ACTH), which is known as a clinical examination method for Cushing's syndrome and adrenal tumor in the internal medicine region, for the purpose of providing a lighting device that is difficult to cause stress when used for lighting. ) To study the relationship between lighting and stress. As a result, when stress occurs, a phenomenon is found in which the ACTH level in human blood rises, and this increase in ACTH level increases with the magnitude of the stress. It was found that the susceptibility to stress caused by quantification was quantified. ACTH is a peptide hormone consisting of 39 amino acids secreted from the anterior pituitary with a molecular weight of about 4,500, and is a substance that promotes the production and secretion of steroid hormones in the adrenal cortex. In addition, it is known that ACTH levels in human blood have daily fluctuations, reach the highest level in the early morning, and then gradually decrease toward midnight.

  As a result of searching for various light sources by the present applicant based on the above knowledge, light that does not substantially increase the ACTH level in human blood is less likely to cause stress when used for illumination and is directed to a comfortable illumination space. It was found to be suitable for a lighting device.

  Based on this result, the present applicants are incandescent bulbs enclosing a composition comprising krypton gas and nitrogen gas, or a composition comprising xenon gas and nitrogen gas, having a wavelength of about 290 nm to An incandescent bulb capable of emitting light rich in ultraviolet rays of 400 nm, and a power supply means for energizing the incandescent bulb under a DC voltage of about 105% to 130% or less of its rating, and adrenal cortex in human blood Provided is a lighting device that emits light that does not substantially increase stimulating hormone levels. (For example, see Patent Document 2)

  Further, the applicants of the present invention have applied a composition containing krypton gas and nitrogen gas or a composition containing xenon gas and nitrogen gas so that the internal pressure of the incandescent bulb is about 700 to 800 Torr when turned on. An enclosed incandescent lamp and power supply means for energizing the incandescent lamp under a DC voltage of about 105% to 130% or less of its rating, and the appearance latency of a P300 wave in a human event-related potential (auditory induction potential) An illumination device that emits light that does not substantially delay time is provided (see, for example, Patent Document 3).

  In addition, the present applicants activate the human serotonin nervous system and do not substantially increase the level of blood noradrenaline, but reduce the aggression and reduce the factors that cause a so-called “crisp” condition. An application for an invention of a lighting device that radiates light having an action has been filed (see, for example, Patent Document 4).

  According to the present invention, the light containing near ultraviolet light having a wavelength of 320 nm or more and less than 380 nm together with a visible light component having a wavelength of 380 nm or more and 780 nm or less has an action of activating the human serotonin nervous system, and further, this light is noradrenaline in blood. It has been found that it has an action that does not substantially improve the level, and when a lighting device using a light source that radiates such light is used as normal nighttime or indoor lighting, it activates the human serotonin nervous system, The present invention has been completed by finding that it does not substantially improve the level of noradrenaline in humans and reduces the factors that cause humans to become “killed”.

  Recently, lighting devices using LEDs (light emitting diodes) as light sources have high luminous efficiency, low power consumption, long life, small size, easy handling, no mercury and other harmful substances, and heat generation. Therefore, it is widely used as a lighting application in place of conventional lighting devices such as incandescent bulbs and fluorescent lamps.

  However, Patent Documents 1 to 3 do not disclose an illumination device that uses an LED as a light source and that exhibits the above effects. Further, in Patent Document 4, although an illumination device using an LED as a light source is exemplified, the light emitted by the white light LED that combines the blue LED element and the phosphor that emits fluorescence by the light emitted by the element is It has not been shown to reduce eye fatigue and cognitive / decision decline.

Japanese Patent No. 3230003 Japanese Patent No. 2934923 Japanese Patent No. 2934926 International Publication Number WO2010 / 041717A1

“Clinical EEG 4th Edition” Teruo Okuma, Medical School, November 15, 1991, “23 Brain Spinal Cord Evoked Potential, Event Related Potential” P443-445, “Visual Evoked Potential” P461-468, “Event Related Potential” P468-474

  As shown in the above-mentioned patent documents and the like, the effect that specific light reduces the stress by suppressing the level of human adrenocorticotropic hormone (ACTH), and it is difficult to cause eye fatigue and cognitive / judgement. Playing has been confirmed. However, even when an LED or organic EL that emits white light by blue light from a blue light emitting LED element and longer wavelength light from a phosphor excited by blue light is used as a light source, such eye fatigue and hearing It has not been confirmed that the decline in cognitive / judgment power via the Internet is reduced. An object of this invention is to provide the illuminating device which can suppress a human eye fatigue and the fall of cognition / judgment power also in the light source using LED.

  The present invention is an illuminating device that uses a blue light emitted from a blue light emitting LED element as a light source and an LED that emits white light by longer wavelength light from a phosphor excited by blue light. Changes in appearance latency of visual evoked potential (F-VEP P100 wave: brain response to visual stimulus) as an index of eye fatigue and / or appearance of auditory evoked potential (P300 wave) as an index of cognitive / judgement decline It is characterized by emitting light that does not substantially increase the latency delay, and has the effect of hardly causing eye fatigue and deterioration of cognition and judgment. Refer to Non-Patent Document 1 for the electroencephalogram in this specification.

  In order to achieve the above-described effects, the present invention configures an illuminating device using a light source composed of an LED element having the characteristics described later. The illuminating device according to the present invention can be various illuminations used indoors, outdoors, in a vehicle such as a desk lamp and a ceiling light.

The LED as a light source is an LED that emits white light (hereinafter, referred to as a white light LED) that combines a blue light emitting LED element and a phosphor. The blue light emitted from the blue light emitted from the blue light emitting LED element and the phosphor excited by the blue light. White light having the above-mentioned effects as a whole is obtained by light having a longer wavelength. The blue light-emitting LED element is an LED element that emits light of 425 nm to 465 nm made of a sapphire-based gallium nitride-based material, and the phosphor is made of a silica-based material, and is excited by blue LED light emission to 600 nm to 680 nm. It emits fluorescence having a peak. In the present specification, a component that is composed of members such as a blue LED element, a phosphor, an electrode, and an encapsulant and emits white light is referred to as a “white light LED package”.

  According to the present invention, in a lighting device, a white light LED package is used as a light source, and a change in human visual induction potential (F-VEP P100 wave) and / or a delay in appearance latency of auditory induction potential (P300 wave) is substantially reduced. Irradiate light that does not increase.

  In the present invention, the white light LED comprises a blue LED element and a phosphor that emits fluorescence having a wavelength longer than the emission wavelength of the blue LED element disposed on the light emitting side of the LED element. The optical LED has a continuous spectrum in the visible light region having a spectral energy of a wavelength of 400 nm to 800 nm, and is derived from a first peak caused by a blue LED element at 425 nm to 465 nm and a phosphor at 600 nm to 680 nm. It has a broad second peak and emits white light that forms a shoulder at 480 nm to 510 nm.

  The present invention provides a phosphor in which the white light LED emits fluorescence having a longer wavelength than the three LED elements connected in parallel and the LED element disposed on the light emitting side of the three LED elements. The irradiation unit includes a plurality of series connection branches in which a plurality of white light LEDs are connected in series, and a condensing lens plate and a condensing lens provided on the side that emits the light of the white light LEDs. It was set as the comprised illuminating device.

  The present invention includes a power supply device and a dimming circuit in which a switching element is connected in series to the white light LED, and the switching element controls an energization rate by pulse width control.

The lighting device of the present invention can be used for desk lighting devices, indoor lighting devices, in-car lighting devices, or aircraft cabins, inboards, outdoors, etc., and any space can be illuminated. Good. Other lighting spaces include private houses, condominiums, schools, studios, beauty salons, hospitals, factories, office buildings, offices, inns, hotels, restaurants, banquet halls, wedding halls, conference halls, shops, and supermarkets. It may be an indoor or outdoor space of various facilities such as department stores, art museums, museums, performance venues, halls, gymnasiums, stadiums, barns, poultry houses, fish farms, animal factories, plant factories. Also, table lamps such as arm lights, desk lamps, hurricane lamps, table lamps, mini lamps, or shelf-mounted lights, ceiling-mounted lights, downlights, wall-mounted lights, hanging lights, chandeliers, swag lamps, floor lamps Housed in or attached to indoor and outdoor lighting fixtures such as garden lights, gate lights, etc., and these lighting fixtures can be used for study, atelier, children's room, bedroom, living room, dining room, kitchen, toilet, toilet, bathroom, Corridor, stairs, balcony, entrance, reading room, classroom, hall, lobby, waiting room, treatment room, operating room, control room, office room, drafting room, laboratory, lounge, guest room, clerk room, cooking room, driver's room, It may be installed or attached at appropriate places inside and outside the breeding room and cultivation room.

FIG. 1 is a front view illustrating the configuration of an illumination device using an LED light source according to the present invention. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a bottom view of the illumination head of the present invention. FIG. 4 is a diagram for explaining the arrangement of the condensing lens and LEDs in the condensing lens plate. FIG. 5 is a diagram for explaining the spectrum of the LED light source according to the present invention. FIG. 6 is a diagram for explaining the configuration of the LED circuit according to the present invention. FIG. 7 is a diagram for explaining the configuration of the driving power supply circuit according to the present invention. FIG. 8 is a time chart for explaining the relationship between the operation of the operation switch according to the present invention and the illuminance. FIG. 9 is a diagram for explaining the rate of change in the appearance latency of the F-EVP P100 wave of the present invention light and normal light. FIG. 10 is a diagram for explaining the rate of change in the appearance latency of the P300 wave of the present invention light and normal light. FIG. 11 is a diagram for explaining the change rate of the appearance latency of the F-EVP P100 wave of the light source including the light of the present invention and near ultraviolet rays.

  The structure of the table-top lighting apparatus using the white light LED light source concerning the 1st Example of this invention is demonstrated using FIGS. 1-4. FIG. 1 is a front view of a desk lamp, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a bottom view of the lighting head unit. FIG. 4 is a diagram for explaining the relationship between the arrangement of the LED elements on the condenser lens plate and the condenser lens.

  The tabletop lighting device includes a base 1, an arm 2, and a lighting head 3. The base 1 includes a base 11, an arm mounting portion 13, an operation switch 15, and a turntable mechanism 17, and further includes a driving power supply device (not shown) in the base 11. The base 11 has a weight or a support mechanism that can support the arm 2 and the lighting head 3 without overturning. The arm attachment portion 13 includes a mechanism that supports the arm 2 and that allows the arm 2 to tilt forward and backward. The operation switch 15 is a switch that blinks the lighting device and changes the illuminance of the LED light source. The turntable mechanism 17 is a mechanism that enables the arm 2 to rotate left and right.

  The arm 2 is a member that supports the illumination head 3. The arm 2 is formed in, for example, a hollow tube 21 that does not have flexibility, and can be tilted back and forth by the arm mounting portion 13 and the angle thereof can be maintained. An electric wire 23 for supplying electric power to the LED element is accommodated in the arm 2.

  The illumination head 3 includes a condensing lens plate 31 made of synthetic resin, a condensing lens 33 formed of synthetic resin in a hemispherical shape, a head cover 35, and an arm mounting portion 37. The illumination unit of the illumination head includes a condenser lens plate 31, a condenser lens 33, and a white light LED. The condensing lens plate 31 is a transparent member on which the condensing lens 33 is provided so as to cover the side of the white LED and white light LED that are not shown in the figure. The portion other than the condensing lens 33 of the condensing lens plate 31 is smoked to make it opaque and hide the LED substrate located on the back surface. The condensing lens 33 has a function of condensing and diffusing light from the white light LED provided on the back surface. The head cover 35 is a member that covers the upper surface of the lighting head 3. The arm attachment portion 37 is a member for attaching the illumination head to the tip of the arm 2 and is movable in the front-rear and left-right directions. The condenser lens plate 31 is provided with a plurality of fixing holes 39 for attaching the plate to the illumination head 3.

  The structure of the condenser lens plate 31 of the illumination head 3 will be described with reference to FIG. 4 is a front view of the condensing lens plate 31 (viewed from below in FIG. 3). As an example, the condenser lens plate 31 is provided with 24 condenser lenses 33 concentrically. One white LED is disposed on the back surface of the condenser lens 33, and is configured so that unevenness in illuminance on the irradiated surface does not occur. By adopting such a configuration and structure, eye fatigue and a decrease in cognition and judgment are effectively suppressed. In other words, the curved shape of the arm does not cause a feeling of pressure, and the illumination head is flat and has no pressure feeling so that the irradiation part and the condenser lens part cannot be directly seen when viewed from the side. It has become. Furthermore, by installing a hemispherical lens on the light emitting side of the white light LED package, the light is not in a beam shape or a narrowed shape while irradiating a suitable range on the tabletop (working area), and It does not spread unnecessarily. The white light LED made into a multi-chip type (three blue LED elements are used in one package and arranged in a triangle) also has an effect of appropriately diffusing light. Since the LEDs concentrically arranged are arranged so as to have the same degree on any circumference, it is possible to irradiate a range that can sufficiently cover the work area on the table. In addition, the condenser lens suppresses unnecessary diffusion of light from the LED, the lens plate is smoked, and the irradiation part is appropriately covered, making it difficult to feel glare from the LED light source. . These effects reduce the burden on the eyes and discomfort, and the effects of the present invention are more effectively exhibited.

The LED element 32 is an LED that emits blue light made of a sapphire-based gallium nitride-based material, and emits light having an emission maximum at 425 nm to 465 nm, and does not substantially emit light in the near ultraviolet region. The light emitting side of the LED element 32 is covered with a silica-based phosphor (not shown) encapsulated in a transparent encapsulant made of synthetic resin such as silicon resin or epoxy resin. Blue light from the LED element 32 that emits blue light excites the phosphor to emit longer wavelength fluorescence, and the blue light and longer wavelength fluorescence are combined to emit white light. As a silica-based phosphor, a crystalline inorganic compound serving as a base material into which an activator serving as a luminescent center is introduced can be used. As a combination of a crystal serving as a base material and an activator, (“matrix crystal: attached For example, (Sr, Ca, Ba) ₂ SiO ₄ : Eu system (yellow phosphor), (Ba, Sr) ₂ SiO ₄ : Eu system (yellow phosphor), La ₃ Si ₆ N ₁₁ : Ce system (yellow phosphor), (Ca, Sr) ₂ Si ₅ N ₈ : Eu system (red phosphor), CaAlSiN ₃ : Eu system (red phosphor), (Sr, Ba) ₃ SiO ₅ : Eu system (red phosphor), (Ca, Sr) AlSiN ₃ : Eu system (red phosphor), (Ba, Sr) ₂ SiO ₄ : Eu system (green phosphor), Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce-based (green phosphor), Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce system (green phosphor), (Sr, Ba) SiO ₂ N ₂ : Eu system (green phosphor), Ba ₃ Si ₆ O ₁₂ N ₂ : Eu system (green phosphor), Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu system (orange phosphor), (Ba, Sr, Ca) Si ₂ O ₂ N ₂ : Eu system (yellow to green phosphor), Ca ₈ MgSi ₄ O Those having a basic composition such as ₁₆ C ₁₂ : Eu (green phosphor) can be used alone or in combination of two or more. Note that the emission intensity and wavelength of each phosphor can be adjusted by the composition of the base crystal or the type and concentration of the activator, and light preferable for the present invention can be obtained. Three LED elements 32 are used for each white light LED, and in this example, a total of 72 LED elements are provided.

  An example of the spectrum of white light from the illumination head 3 is shown in FIG. The spectrum of FIG. 5 has a blue first peak (about 100 μW / nm) due to the blue LED element near 430 nm and a broad orange second peak (about 200 μW / nm) near 620 nm. Further, a light blue shoulder (about 80 μW / nm) is formed in the vicinity of 490 nm.

The light of the illumination device of the present invention using such a white light LED light source has the following characteristics.
A. The spectral energy intensity of the second peak is preferably 1 to 3 times, preferably 1.5 to 2.5 times, more preferably 1.7 to 2.2 times that of the first peak (for testing purposes). (Approximately 2 times for the actual machine used) and 1 to 3 times, preferably 1.5 to 2.5 times, more preferably 1.7 to 2.2 times the shoulder (preferably used for testing) (In actual machines, it is more than twice).
B. The irradiated light has a light bulb color to daylight color, and preferably a color temperature of 2,500 K to 4,000 K (3,022 K in the actual machine used for the test).
C. The average color rendering index (Ra) is 90 or more, preferably 95 or more (96.4 is achieved in the actual machine used for the test), and any of the special color rendering indices (R _{1 to} R ₁₄ ) is 80 or more, preferably It is desirable to have an excellent color rendering property of 90 or more (achieved 90.1 or more in the actual machine used in the test).
D. As the illuminance, for example, it is desirable to obtain an illuminance of 500 lux to 2,500 lux at a distance of 40 cm from the irradiation part (2,000 lux in the actual machine used for the test and 580 lux without the condenser lens). .

  An example of the configuration of the LED circuit will be described with reference to FIG. The LED circuit 40 connects three blue LED elements 32-11, 32-12, and 32-13 in parallel to form a white LED package D1, and six such white LED packages D1 to D6 are connected in series. Are connected to each other to form a series connection branch S1, and such series connection branches S1 to S4 are connected in parallel.

  An example of the configuration of the power supply device for driving the LED element will be described with reference to FIG. The drive power supply device 5 includes a switching stabilized power supply 51, a control microcomputer 53, a current limiting resistor 55, and a switching element 57. The switching stabilization power supply 51 converts the AC input input via the AC terminal Tad into a DC voltage of 24 V necessary for lighting the LEDs connected in series, and supplies a DC 5 V necessary for the operation of the control microcomputer 53. It is means to do. The control microcomputer 53 is a microcomputer in charge of turning on / off the LED and dimming. A current limiting resistor 55 is connected in series to the 24V output of the switching stabilized power supply 51, and the LED circuit 40 is connected via the DC terminal Tdc. The switching element 57 connected to the output of the control microcomputer 53 is means for switching the current of the LED circuit 40, and controls lighting / extinguishing (extinguishing) of the LED circuit 40 and energization rate (duty ratio) during lighting. . Further, an operation switch 15 is connected to the control microcomputer 53 to control the operating current of the LED. Commercially available parts can be used as appropriate for the switching stabilized power supply 51 and the control microcomputer 53.

The operation of the drive power supply device 5 will be described with reference to the time chart of FIG. 8A shows the light emission intensity (illuminance) of the LED, and FIG. 8B shows the operating state of the operation switch 15. When the operation switch 15 is turned on and now the time T _0, the control microcomputer 53, the switching element 57 is energized state, LED circuit 40 is set to the maximum illumination intensity that is set in advance. Press and hold the operation switch 15, the control microcomputer 53, a minimum illuminance gradually pulled time T _2, the duty factor of the switching element 57 toward the preset minimum illuminance from the time T ₁ which is set in advance at a fixed rate To reach. Control microcomputer 53, to maintain a minimum illuminance maintaining the duty ratio of the switching element 57 from time T2 to time T ₃ to a preset constant. The control microcomputer 53 at time T ₃ is gradually increasing the duty factor of the switching element 57 at a constant rate towards the maximum illumination intensity, LED circuit 40 again reaches a maximum illumination intensity at time T4. Control microcomputer 53 as long as the operation switch 15 is turned on is, repeat the lighting sequence in brightness from time T ₀ to T _4. For example, when turning off the operation switch 15 at time T _6, thereafter, the illumination is maintained illuminance of time T _6. In this way, an arbitrary illuminance can be selected and illuminated. The LED circuit 40 to flashing lights, at any point of time t ₆ after, may be off the operation switch 15 again.

  As a result of the volunteer test, it has been found that such an illumination device using a white light LED as a light source has the following effects.

[Outline of Volunteer Exam]
Six subjects (three healthy men and women in their twenties each) were read for 90 minutes under white light or normal light environment from an illumination device using the white light LED light source of the present invention. Measure the appearance latency of visual induction potential (F-VEP P100 wave) and haptic induction potential (P300 wave) with an induction potential measurement device before reading and every 30 minutes from the start of reading (30 minutes, 60 minutes, 90 minutes) did. Regarding the measured values of each induced potential, the changes over time were compared with those before reading, and the degree of eye fatigue and cognitive / judgment changes due to the light source were compared. Each subject was subjected to the crossover method under both light and normal light environments using the white light LED according to the present invention as a light source. That is, since it is considered that the visual work and the measurement of the induced potential may be accustomed after the second time, half of the subjects are in the order of white LED light-normal light according to the present invention, and the other half are normal light. -It implemented in order of the white LED light concerning this invention. During that time, an interval of one week was set. The illuminance at the work place was 2000 lux. As the normal light, an inverter fluorescent lamp, KL-H599, manufactured by Twin Bird Industries, Ltd. was used. The windows were shielded from being affected by external light such as sunlight. The test was conducted in the morning. Each work space was partitioned to minimize the impact of the subjects.

  Reading was done as a visual task for fatigue induction. Books, reading speed, etc. were not particularly unified, but as a general rule, each subject brought “Japanese paperback books with about 16 lines per page” and read at their own pace.

[Measurement of induced potential]
The induced potential measurement is a method in which the brain response to a certain stimulus (light, pattern, sound, etc.) is recorded as an electroencephalogram to examine the function of the brain. However, this brain wave is so weak that it cannot be observed because it is buried in a normal brain wave. Therefore, by superimposing the brain waves generated by the stimulation multiple times (in this test, the visual guidance is 100 times and the auditory guidance is 30 times), the normal brain wave as the background is erased, Only the electroencephalogram that has reacted is analyzed.

  The visual EEG shows a unique waveform about 100 milliseconds after stimulation, and is observed as a downward peak called a P100 wave (in this test, as a visual induction potential, a response to a flash stimulation (Flash Visual Evoked Potential, F-VEP) was measured.) The auditory electroencephalogram shows a characteristic waveform approximately 300 milliseconds after stimulation, and is observed as a downward peak called P300 wave. When eye fatigue or cognitive / judgment declines, the response of the brain to the stimulus is affected, and the phenomenon that the appearance time (latency) of these unique peaks is delayed or shaken is observed. By comparing, the degree of fatigue and the degree of recognition can be objectively determined. In this test, measurement was performed using an “inductive potential measuring device SYNAX ER1100” manufactured by NEC Corporation and a “multipurpose electroencephalograph 1A97A” manufactured by SANEI Corporation for xenon flash control. It should be noted that no special qualification is required for the induction potential measurement.

[Details of Inductive Potential Measurement Method]
1) The parts where electrodes were attached to the scalp and earlobe were wiped with 70% alcohol cotton and degreased. The mounting paste was applied to the mounting part and the electrode, the electrode was mounted, and fixed with gauze. It was installed at 10 locations per person.
2) Lying on the bed for measurement, we measured each induction potential when we were able to relax while monitoring the degree of tension with brain waves.
3) The visual evoked potential was measured by flashing a xenon flashlight 100 times at intervals of 1 second 30 cm in front of the eye. Subject was resting during that time. The visual evoked potential was measured twice.
4) The auditory evoked potential was measured with headphones. Sounds with a constant frequency (poe) are emitted at intervals of approximately 0.7 seconds, but sounds with different frequencies (pee) are mixed irregularly. The subject counted the number of times the mixed sound (pea) was mixed. This was continued until the total number of normal responses to the mixed sound reached 20 times. This measurement was performed twice.
5) Moved to the reading table with the electrodes attached and started reading.
6) The above 1) to 5) were repeated every 30 minutes.
7) The electrode was removed, and the attached electrode mounting paste was wiped with 70% alcohol cotton to complete the measurement.

  Based on the measurement results, the appearance latency of the P100 wave caused by visual guidance and the appearance latency of the P300 wave caused by auditory guidance were analyzed using the induction electron measuring device SYNAXER 1100. Based on each measured value after visual work, the change rate of appearance latency at each time with respect to the measured value before work was calculated for each subject according to the following equation (1). That is, the change rate of the appearance latency of the P100 wave (P300 wave) is the value obtained by subtracting the measurement value of the appearance latency before the visual work from the measurement value of the appearance latency after the visual work for each time. It is expressed by dividing by the measured appearance latency.

[Effect of the device of the present invention on eye fatigue]
Table 1 shows the change rate of the appearance latency of the visual induction potential (F-VEP P100 wave) until 90 minutes after the work.

  Table 1 shows the change in the appearance latency of the F-VEP P100 wave up to 90 minutes after the work. F-VEP is a simple response of the brain to light, and the change in the appearance latency of the P100 wave caused by eye fatigue is not a delay in the transmission speed of a visual signal from the optic nerve to the visual cortex of the cerebrum, but a response in the visual cortex. This is caused by time lag. Therefore, except for some measurement errors, it is unlikely that the reaction time will be greatly shortened, and even if working for a long time, no change in the appearance latency suggests that eye fatigue is reduced. Can be seen as.

  The analysis result of the rate of change of the visual induction potential (F-VEP P100 wave) will be described with reference to FIG. In FIG. 9, the upper part of FIG. 9A shows the rate of change of the F-VEP P100 wave when the white light LED light source of the present invention is used, and the lower part of FIG. 9B shows the F in the case of normal light. -Shows the rate of change of VEP P100 waves. As a result of analyzing the data, when compared with the change rate of the appearance latency after visual work (F-VRP P100 wave) based on the appearance latency before the visual work represented by the formula 1, in many subjects, In the illumination light (invention light) using the LED light source according to the present invention, the change in the appearance latency was small compared with the normal light, and the change rate was 5% at most. On the other hand, when normal light was used, the change in the rate of change of the appearance latency of the F-VEP P100 wave before the work was large, and sometimes it was about 10% (see FIG. 9B). When the LED light source of the present invention is used, the rate of change of the appearance latency of the F-VEP P100 wave is closer to “0” than when a normal light source is used (see FIG. 9A). Variation among subjects tended to be small. This result suggests that the light of the present invention has a feature that eye fatigue does not easily occur.

[Effect of the invention intelligence device on cognitive / judgement decline]
Table 2 shows the change rate of the appearance latency of the auditory induction potential (P300 wave) up to 90 minutes after the work.

  The analysis result of the change rate of the auditory induction potential (P300 wave) will be described with reference to FIG. In FIG. 10, the upper part of FIG. 10A shows the rate of change in the appearance latency of the P300 wave when the white light LED light source of the present invention is used, and the lower part of FIG. 10B shows the case of normal light. The rate of change in the appearance latency of the P300 wave is shown. The auditory evoked potential (P300 wave) looks at the higher-order functions of the brain, and the auditory signal that reaches the primary auditory cortex of the cerebral cortex automatically determines a certain meaning in the secondary sensory cortex. The time to appear is seen, and the appearance latency tends to be delayed due to a decline in cognition and judgment. As a result of analyzing the data between the two light sources for the P300 wave, when compared with the change rate of the appearance latency after the visual work based on the appearance latency before the visual work, in the case of normal light, the appearance of the P300 wave While the change rate of the latency was larger than “0”, that is, the delay increased (see FIG. 10B), the light of the present invention was 90 from the start of the visual work compared with the normal light. The rate of change in the appearance latency of the auditory evoked potential (P300 wave) was clearly small until minutes later (that is, the delay was small), and the difference was particularly significant until 60 minutes later (see FIG. 10A). . This result suggests that the light of the present invention has a feature that it is difficult to cause a decrease in cognition and judgment through hearing.

  That is, according to the present invention, the change in the appearance latency of the human visual induction potential (F-VEP P100 wave) and / or the delay of the auditory induction potential (P300 wave) can be substantially not increased.

  From the above results, in the light environment of the present invention, the fluctuation in the appearance latency of the F-VEP P100 wave is small and the delay in the appearance latency of the P300 wave is small as compared with a normal fluorescent lamp. It was suggested that the decline of cognitive / judgment power through the system is easy to reduce.

  In the above description, the table lighting device has been described as an example of the lighting device using the LED light source of the present invention. However, the present invention is not limited to the table lighting device in view of the function of the light of the present invention, and other indoor lighting or outdoor Naturally, it can be applied to lighting, and the effect can be expected as well.

<Comparative example>
In the same manner as in the above volunteer test, a lighting device containing 5% of near-ultraviolet rays of 320 nm to 380 nm with respect to the radiant energy of visible light, which is the same as that used in Example 1 <Experiment 1> of Patent Document 4, is used. The effects on eye fatigue were examined and compared with the lighting device of the present invention. The results are shown in Table 3 and FIG. In FIG. 11, the upper part of FIG. 11A shows the change rate of the appearance latency of the F-VEP P100 wave when the white light LED light source of the present invention is used, and the lower part of FIG. 4 shows the change rate of the appearance latency of the F-VEP P100 wave in the case of the same control light as that used in Example 1 <Experiment 1>.

  Referring to Table 3 and FIG. 11, when the apparatus of the present invention is used, the rate of change in the appearance latency of the visual induction potential (F-VEP P100 wave) is higher than when the control light including the near ultraviolet component is used. It was small. This suggests that the illuminating device of the present invention has a stronger effect of preventing eye fatigue compared to an illuminating device that emits light including near ultraviolet rays.

That is, Patent Document 4 describes that in Example 2, it is considered that the effect of hardly causing eye fatigue is also obtained, but the differences from the illumination device of the present invention are as follows. Can be mentioned.
A. Illumination in Embodiment 1 of Example 2 of Patent Document 4 uses ultraviolet light to near ultraviolet light as excitation light, and emits blue, green, and red phosphors.
B. Including near ultraviolet light.
C. There is no disclosure regarding the use of a structure or configuration for desk lighting that effectively suppresses eye fatigue and cognitive decline.
About the illuminating device of the present invention, by adopting the structure and configuration as shown in FIGS. 1 to 4, the effect of reducing the change rate of the F-VEP P100 wave is seen, and the effect of preventing eye fatigue is strong. It suggests.

1: Base 11: Base 13: Arm mounting portion 15: Operation switch 17: Turntable mechanism 2: Arm 21: Hollow tube 23: Electric wire 3: Lighting head 31: Condensing lens plate 32: LED element 33: Collection Optical lens 35: Head cover 37: Arm attachment part 39: Fixing hole 40: LED circuit 5: Driving power supply device 51: Switching stabilization power supply 53: Control microcomputer 55: Current limiting resistor 57: Switching element

Claims (7)

Using a white light LED package as a light source, light that does not substantially increase the change in the appearance latency of the human visual induction potential (F-VEP P100 wave) and / or the delay in the appearance latency of the auditory induction potential (P300 wave) Lighting device to irradiate. The white light LED package includes a blue LED element and a phosphor that emits fluorescence having a wavelength longer than the emission wavelength of the blue LED element disposed on the light emitting side of the LED element. The spectral energy has a continuous spectrum in the visible light region with a wavelength of 400 nm to 800 nm, a first peak due to the blue LED element at 425 nm to 465 nm, and a broad due to the phosphor at 600 nm to 680 nm. The illumination device according to claim 1, wherein the illumination device emits light having a second peak and forming a shoulder at 480 nm to 500 nm. 3. The spectral energy intensity of the second peak in the spectrum is 1 to 3 times that of the first peak and 1 to 3 times that of the shoulder. The lighting device described. The blue LED element is made of a sapphire-based gallium nitride material, and the phosphor is made of one or more materials selected from silica materials. The lighting device according to item. A plurality of parallel connection branches connected in series with the white LED package are arranged concentrically, a condenser lens is provided on the light emitting side of the LED package, and human visual induction potential (F-VEP) 5. The illumination according to claim 1, wherein a change in appearance latency (P100 wave) and / or a delay of auditory induction potential (P300 wave) is not substantially increased. apparatus. 6. The power supply device according to claim 1, further comprising a power supply device that connects a switching element in series to the white LED package and controls the switching element by pulse width control, and a dimming circuit. Lighting equipment. The lighting device according to any one of claims 1 to 6, wherein the lighting device is a table lighting device, an indoor lighting device, or an in-vehicle lighting device.

Images