JP6664646B2 - Lighting equipment and light collection method - Google Patents

Description

The present invention generally relates to a lighting device that functions as a lighting device and provides brightness necessary for a short-term countermeasure in an emergency such as loss of a commercial power supply at night, and a light collecting method thereof.

2. Description of the Related Art A display product that indicates an evacuation route and a position by using phosphorescence of a luminous material without lighting at night has been conventionally proposed. Also, there is a widespread use of a marker product that illuminates a guide map or the like by using phosphorescence of a luminous material when a commercial power supply is lost. Further, there is a device that stores power using a commercial power supply in a normal time and uses the stored power in an emergency such as power loss for lighting.

Patent Documents 1 to 4 propose the use of light. However, these inventions aim at energy saving and do not aim at securing luminous intensity sufficient to illuminate the surroundings. For this reason, while functioning as a lighting fixture, it is difficult to provide an amount of light sufficient for emergency lighting.

Patent Literatures 5 and 6 propose lighting equipment using an emergency power supply using a storage battery. However, in the event of an emergency, if a storage battery or a lighting device fails and becomes unusable, there is a possibility of causing a danger to human life, and it is not possible to rely entirely on such a device.

Patent No. 3427797 public relations JP 2001-350143 A JP 2010-040385 public relations Public information of JP-A-7-281032 JP 2014-229467 A JP-A-2015-15191

With existing instruments that use light-glowing materials and receive light from sunlight, the light intensity of phosphorescence is low after the time of use and after the time of use, and sufficient light intensity to illuminate the surroundings can be obtained. Absent. Furthermore, since these fixtures do not function as ordinary lighting, it is necessary to separately provide lighting fixtures. In a device that receives light from a general lighting device and stores light, the illuminance of the excitation light required for exciting the light storage material is low, and as a result, the phosphorescence due to the light storage has a low luminous intensity. In addition, due to the low illuminance received from these general lighting fixtures, it takes a long time for the phosphorescent material to reach the phosphorescent state.

In order to solve these problems, the present invention normally provides a lighting device that functions as a lighting device, and that can perform a countermeasure action without groping even in the dark for a short time when power is lost such as a power failure, and thereafter, It is another object of the present invention to provide a lighting fixture having a display function for confirming the position of the phosphorescent material by phosphorescence of the phosphorescent material.

In order to achieve the above object, an invention according to claim 1 is a lighting apparatus in which a light source and a light guide plate for guiding the light are arranged, wherein a convex protrusion is provided on one surface of the light guide plate, and the protrusion is provided. A light-storing diffuse reflection sheet is provided in opposition to the light-storing diffuse reflection sheet, and the light-storing diffusion reflection sheet includes a light storage function layer that stores light condensed by the convex protrusions and a diffusion reflection layer that reflects light transmitted therethrough. It is a lighting fixture characterized by comprising.
The invention according to claim 2 includes a light source, a light guide plate for guiding light from the light source, a convex protrusion provided on one surface of the light guide plate, and a light storage function layer provided opposite to the protrusion. And a diffuse reflection layer for reflecting light transmitted through the light storage function layer, and condensing the light from the light guide plate to the light storage function layer at the protrusions.
The invention according to claim 3 is the lighting apparatus according to claim 1 , wherein the convex protrusion provided on one surface of the light guide plate has a hemispherical lens shape.
According to a fourth aspect of the present invention, in the phosphorescent material used in the phosphorescent functional layer, the total energy of light having a wavelength whose excitation spectrum is in the range of 0.38 to 0.49 μm is 20% or more of the total energy of the entire excitation spectrum. a luminaire請Motomeko 1 and 3, wherein the use of畜光material becomes.
According to a fifth aspect of the present invention, the luminous function layer illuminates the surface of the luminous function layer having a planar shape of 25 cm square with visible light of 700 lumen for 30 seconds, then stops the luminous function layer on a line perpendicular to the center of the luminous function layer. 5. The lighting device according to claim 1, wherein the illuminating function layer has a phosphorescent light-emitting capability in which the measured illuminance after 2 seconds at a position 15 cm away from the device is 40 lux or more.

According to the luminaire of the present invention as set forth in claims 1 to 5, the illuminance in the luminous function layer, that is, the illuminance of the excitation light is larger at the converging point than in the case of uniform irradiation, so that the luminous intensity of the phosphorescent function layer is reduced. Can be bigger. As a result, the lighting fixture of the present invention can provide illumination with phosphorescence of sufficient luminosity to enable emergency countermeasures in case of emergency at night while being used as a general lighting fixture at normal times.

Detailed solution

Various characteristics required for the present invention obtained from measurement results regarding the structure of the light storage material and the lighting device used for the lighting device of the present invention will be described. According to the measurement results, it was found that the initial phosphorescence and the total amount of phosphorescence increased as the excitation light illuminance increased. In order to achieve the object of the present invention, it is necessary to increase the initial luminous intensity of phosphorescence after stopping the light source and the total amount of phosphorescent light, and for that purpose, it is necessary to increase the illuminance of excitation light to the luminous material. In order to achieve this, we will study a structure to increase the illuminance of the excitation light for the luminous function layer of the luminaire, and evaluate the phosphorescence emission ability of the luminaire in order to specify the characteristics of the luminous material used in the luminaire and the criteria for the required amount. I decided how to do it.

The state of the decay of the phosphorescence intensity due to the illuminating light due to the elapsed time was observed from the decay curve. In the relationship between the phosphorescence emission luminous intensity and the elapsed time in the graphs of FIGS. 3 and 9, the luminous intensity two seconds after the excitation light was stopped was defined as the initial phosphorescence intensity in the present invention.

In the present invention, the illuminance on the surface of the luminous function layer of light that excites electrons of the luminous material is referred to as illuminance of excitation light. The illuminance is a value obtained by numerically processing measurement data of observation light based on standard spectral luminous efficiency, and is a measurement value obtained from an illuminometer that performs this numerical processing.

In the relationship between the initial phosphorescence intensity and the irradiation time in FIG. 1, under the irradiation condition in which the excitation light illuminance is fixed, the irradiation time reaches the irradiation time in which the initial phosphorescence intensity does not increase any more even if the excitation light irradiation time is increased for a specific time or more. The initial phosphorescence at this time is referred to as saturated phosphorescence. The time to reach this luminous intensity, such as t-7 and t-8 in FIG. 1, is called the saturated phosphorescence arrival time. As a result of the observation, as shown in FIGS. 1 and 2, (1) the saturation phosphorescence is increased by increasing the illuminance of the excitation light by the irradiation light. At the same time, it can be confirmed that (2) the saturated phosphorescence arrival time is shortened.

The decay of the phosphorescence of the phosphorescent material is classified into two regions having different attenuation modes. Here, in FIGS. 3 and 9, the phosphorescent luminous intensity of the phosphorescent material stored by the excitation light is approximately the same over a long period of time as the region where the luminous intensity rapidly decreases from a large luminous intensity and decreases in a short time. A region that gradually darkens appears while maintaining the luminous intensity of. When the excitation light illuminance and the excitation light irradiation time are changed to various values as a reference for determining the boundary area, the area where the decay curve of the phosphorescence emission luminosity changes is the first area, the excitation light illuminance, and the excitation light irradiation time are changed. The area where the decay curve of the phosphorescence did not change was defined as the second area. In FIG. 3, the boundary of each area is the turning point.
In the present invention, phosphorescent light emission in the first region is mainly used as an emergency light source. In this region, the phosphorescence luminous intensity is large, and the luminous intensity sufficient to illuminate the surroundings can be provided for several minutes, and emergency response measures can be made possible. Subsequently, in the second area, the light emission is darker than the first area but continues to be long enough to confirm the position, so that a marking function for indicating the position can be provided.

  We examined the appearance of the first and second regions from the damping mechanism, and examined the appropriate usage. Phosphorescence luminous intensity due to animal light basically decreases its luminous intensity according to an attenuation curve. This should be the decay form of the decay curve of FIG. 10 according to the equation shown in FIG. However, in practice, the k value in the equation of FIG. 13 is changed to a different value at the boundary between the first area and the second area as shown in FIGS. This is because observation has confirmed that the second region follows a larger k value than the phosphorescence intensity calculated based on the k value of the first region. If a change in the k value occurs at this conversion point, it is possible that the rate-limiting step in the process of leading to phosphorescence in the entire transition mechanism between the energies of a series of electrons may be alternated. There is. However, there is no data such as ESR at hand and there is no knowledge about the multiplicity of electrons, so the correct mechanism cannot be understood. However, in the actual observation phenomenon, the phosphorescence initial luminous intensity changes due to a change in the excitation light illuminance or the excitation light irradiation time in the first region. Further, the duration of the first area is substantially constant regardless of the change of the above condition. In the second region, it is observed that the decay curve of the phosphorescence always follows the same curve even when the irradiation light illuminance or the excitation light irradiation time changes. Among the above facts, if the illuminance of the excitation light is increased in the first region, the luminous intensity of the phosphorescent light is increased. That is, for the purpose of the present invention, it is necessary to increase the illuminance of the excitation light.

      In order to ensure a certain level of phosphorescence when the light source of the lighting apparatus of the present invention is lost, the structure of the lighting apparatus that increases the excitation light illuminance to the light-storing functional layer that satisfies this condition, and the selection of the light-emitting material that increases the phosphorescence luminous intensity Was done.

      An apparatus for increasing the illuminance of the excitation light to the light-irradiating functional layer has a light guide plate type illumination apparatus structure shown in FIGS. In this structure, the distance between the light source and the luminous material is kept short, and the light confined inside the light guide plate is taken out of the plate while being condensed through the hemispherical projection of the light guide plate as shown in FIG. Irradiate the sheet. By doing so, the structure was made to increase the illuminance of the excitation light.

The phosphor particles in the phosphorescent functional layer of the phosphorescent diffuse reflection sheet tend to emit more light to the light receiving side, and thus emit a large amount of phosphorescent light to the incident side of the sheet. Thus, the effect of phosphorescence can be more utilized.

      In the structure of the light guide plate type lighting device of FIG. 11, the light diffusion / reflection sheet is disposed so as to face and contact the lower portion of the light guide plate as shown in the figure. The structure of the light-storing diffuse reflection sheet has the structure shown in FIG. 7, and sequentially includes a light-storing function layer containing a light-storing material and a diffuse reflection layer containing particles having a high reflectivity and diffuse reflection, sequentially from the side where excitation light is incident. It has a two-layer structure. With this structure, when the light passes through the light storage function layer, the light excites the electrons of the light storage material. The energy of the light absorbed here is only a small part of the light from the light source, and most of the excitation light is reflected by the diffuse reflection layer and used for illumination as white light.

      The light-absorbing function layer absorbs light in a wavelength range effective for excitation from the spectrum of white light, and excites electrons of the light-absorbing material. Since the lighting fixture of the present invention is normally used as a general lighting fixture, the light from the light source is white light in the visible light region, and only the short wavelength side of the white light effectively works for electronic excitation of the light-emitting material.

In the present invention, phosphorescence of a phosphorescent material is used as illumination used in an emergency. The process of phosphorescence emission will be described with reference to the diagram shown in FIG. 12. Excited electron energy returns to the ground state before excitation through internal relaxation, fluorescence emission, part of intersystem crossing, phosphorescence emission, etc. Pass through. In the present invention, the phosphorescent light emission is used for emergency lighting.

8 and 12, the relationship between the length of the wavelength of the spectrum and the magnitude of the difference between the energy levels will be examined. The length of the wavelengths of the excitation spectrum and the phosphorescence spectrum are inversely proportional to the magnitude of the difference between the corresponding energy levels. The diagram shows that the energy level difference of excitation is larger than the energy level difference of phosphorescence of FIG. This corresponds to the fact that the wavelength of the excitation spectrum is shorter than the wavelength of the phosphorescence emission spectrum of FIG.
From the above relationship, in order for phosphorescent light emission to be visible, the wavelength region of the phosphorescent light emission spectrum needs to be included in the wavelength region of visible light. As a result, the wavelength of the spectrum of the excitation light generally belongs to the short wavelength region to the near ultraviolet region of visible light. Then, in order to absorb the white light from the light source and excite the fluorescent material, it is necessary that a part of the excitation light spectrum overlaps with a part of the white light spectrum. Only in this overlapping wavelength region, the fluorescent material can absorb light from the light source. Taking the excitation spectrum of the phosphorescent material shown in FIG. 8 as an example, the dominant wavelength of this absorption is around 350 μm, which is shorter than the visible light region, and is the white color of the LED lighting that does not include light in this region. Light cannot excite the luminous material. However, due to the disorder of the crystal structure of the phosphor material and the fine structure of the transition between the energy levels of the electrons, the main spectral lines are dispersed and the spectrum width is extended to the visible light region. As a result, a region of the excitation spectrum overlapping with the visible light region of white light is generated, and light can be absorbed from the white light. The breadth of the excitation spectrum depends on the physical properties of the light-emitting material and the history of the manufacturing process. It is necessary for the light-emitting material that the energy of the excitation spectrum in this overlapping region be a certain ratio or more to the energy of the entire excitation spectrum. By doing so, large phosphorescence can be obtained.

The phenomenon that increasing the illuminance of the excitation light increases the luminous intensity of phosphorescence and the total amount of phosphorescence means that, in the diagram of FIG. 12, increasing the illuminance of the excitation light increases the number of electrons in the first excitation singlet. Equivalent to. As a result, the phosphorescent light intensity is increased, and the total phosphorescent light amount is also increased. This phenomenon is a phenomenon that appears even when the illuminance of the excitation light and the irradiation time of the excitation light are increased, until the number of electrons in the first excitation singlet no longer increases.

The method and criteria for evaluating the ability of the phosphorescent functional layer to perform emergency lighting as the lighting fixture of the present invention have been established. The method for evaluating the light storage ability is as follows: the surface of the light storage function layer having a plane shape of 25 cm square is irradiated with visible light of 700 lumen for 30 seconds, then the light irradiation is stopped, and the light is stopped on a line perpendicular to the center of the light storage function layer. The illuminance after 2 seconds was measured at a position separated by 15 cm, and this measured value was used as a reference for the light storage ability. In addition, as a criterion of the light storage ability, a measured illuminance of 40 lux or more was determined as a practically useful criterion. The reference value of 40 lux was the value obtained from the sensory test, that is, the illuminance determined to be able to maintain the situation of providing light that enables countermeasure activities in the event of power loss by visual observation.
The characteristics of the light-emitting material, the area of the light-emitting layer, the weight of the light-emitting material per area, that is, the total weight of the light-emitting material belonging to the instrument, the spectral distribution of the excitation light, the luminous intensity of the light source, the excitation time required for the light emission, etc., affect the measured illuminance. Where the measured illuminance obtained as a result of all these factors was taken as the measure of the luminous capacity. By doing so, it is possible to set a criterion for ensuring the light storage ability of the present invention.

Phosphorescence initial luminous intensity change by irradiation time of light from light source Saturated phosphorescence due to excitation light illuminance of irradiation light from light source Temporal change of phosphorescence luminous intensity when excitation light illuminance is changed by irradiation light Light path in light guide plate type lighting equipment Light guide plate hemispherical lens and light condensing on diffuse reflection sheet Diffuse reflection on phosphorescent diffuse reflection sheet Structure of phosphorescent diffuse reflection sheet Example of excitation spectrum and phosphorescence spectrum of phosphorescent material Region division in elapsed time of phosphorescence intensity Decay curve by calculation of various k values Structure of light guide plate type phosphorescent lighting fixture Diagram of electronic excitation and relaxation process of phosphorescent material Differential equations and solutions for damping processes

FIG. 11 shows a light guide plate type lighting device of the present invention, and FIG. 4 shows an optical path in the light guide plate lighting device. In the light guide plate type lighting device of the present invention, light from the light source installed on the side surface of the light guide plate is guided into the inside of the light guide plate as shown in FIG. 4, and the light is confined inside the light guide plate by repeating total reflection within the plate.
Here, as the light source, any light source such as a fluorescent lamp, an LED, and an arc tube can be used. However, for emergency use, LEDs are desirable because of the longevity of the light source, the stability of operation, and the small occupied space in installation. Next, this light is extracted from the light guide plate while being condensed out of the plate using a hemispherical lens-shaped convex portion provided on one side of the light guide plate, passes through the light storage function layer in the diffuse reflection sheet, and is diffusely reflected. The layer reflects light diffusely, and the diffuse reflected light travels across the light guide plate and is used for illumination. Here, there are various methods for extracting light from the light guide plate. (1) A method in which a scratch or a groove is formed on the surface of the light guide plate toward the inside of the plate to scatter light at that portion and extract the light to the outside, A method in which a projection is provided outside the light plate and light is extracted therefrom. (3) Light diffusion and reflection particles are contained in an organic resin having the same refractive index as that of the light guide plate, and the organic resin layer is brought into close contact with the light guide plate so that the light is diffused. A method of diffusing and reflecting the extracted light with the diffuse reflection particles and extracting the light to the outside is used. In the present invention, the illumination device for extracting light while condensing light from the light guide plate is configured by making the outer protrusion of (2) into a hemispherical shape. In this structure, the hemispherical lens-shaped projection serves as a convex lens, and as shown in FIG. 5, collects the light to be extracted to the outside and collects it on the light-storing diffuse reflection sheet, thereby increasing the illuminance of the excitation light to the storage light functional layer. I have. The light thus extracted enters the phosphorescent diffuse reflection sheet, and phosphorescent diffuse reflection is performed by the phosphorescent material particles contained in the phosphorescent functional layer and the diffuse reflection particles of the diffuse reflection layer. Further, light emitted from the light diffusion / reflection sheet according to this structure can illuminate the outside of the lighting device as shown in FIG. With this structure, light with high illuminance can be delivered to the light-emitting layer, and extremely bright phosphorescence can be obtained after stopping irradiation.
The reason that the method (1) is not suitable for the present invention is that the damage of the light extraction portion from the inside of the light guide plate does not cause all of the light to go to the light storage diffuse reflection sheet. Because it cannot be maximized and the light guide plate has large scattering near the light source, the illuminating light becomes bright near the light source, and the illuminance becomes uneven as the distance from the light source increases. It cannot be used effectively.

FIG. 7 shows the structure of the light diffusion and reflection sheet used in the present invention. Composed of two layers: a light-reflective layer, in order from the side where the excitation light is incident, and a diffuse-reflective layer containing diffusely-reflective particles (materials with high diffuse reflectance, such as magnesium carbonate and barium sulfate). I do. A reflective layer using a metal film has been tried to form a highly reflective perfect diffusion surface, but the metal has a high reflectance, but at the same time has a specular reflection. The light extracted from the light guide plate to the reflective layer has a shallow incident angle to the reflective layer, that is, an incident angle closer to parallel to the reflective layer, and the reflected light is directed in a direction perpendicular to the reflective layer required for illumination. Rather than proceed, it travels more horizontally, resulting in a darker lighting fixture. Attempts were made to diffuse the reflected light by roughening the metal surface, but the effect of the improvement was small. From these results, in the present invention, a method was achieved in which a diffuse reflection layer in which particles that diffusely reflect light were contained in an organic resin had a required thickness.

The light-storage material in the light-storage function layer of the light-storing diffuse reflection sheet has at least the total energy of light having a wavelength in the range of 0.38 to 0.55 μm in the excitation spectrum of the light-storage material at least the energy amount of the entire excitation spectrum of the light storage material. It is preferable that the light emitting material is 20% or more. This is because, when the numerical value is lower than 20%, the excitation light cannot be efficiently excited by the white light using the LED as a light source, that is, only a part of the phosphorescent material can absorb the excitation light. In order to solve this, a large amount of expensive phosphorescent materials must be used, which is not rational. Judging from the energy distribution related to the wavelength of the actual excitation spectrum, 20% is appropriate in consideration of fluctuations in quality and the like. The phosphorescent functional layer may be formed as a film, sheet, or plate of various transparent resins such as polyester, nylon, PET, and ABS, or may be formed by dispersing a phosphorescent material in a transparent paint and applying it as a paint. Is also good.

A phosphorescent lighting device embodying the present invention was manufactured. The outer dimensions are 30 × 30 cm, the thickness is 15 mm, and the opening of the illumination has a plane shape of 25 × 25 cm. This is a light guide plate type lighting device using an LED as a light source, and has a hemispherical lens-shaped protrusion formed on one surface of the light guide plate. The light-storing diffuse reflection sheet is a two-layer structure sheet having the structure shown in FIG. 7, and the light-storing function layer is a paint made of NEMOTO Lumi Materials Co., Ltd. as a light-storing material in a high-art # 1000SP acrylic urethane resin paint made of Isamu paint. 1.5 g / cm 2 of N Luminescent Luminova GLL-300M was contained. Lumirror E6SR, # 225 manufactured by Toray Industries, Inc. was used as the diffuse reflection layer. The LED light source has a luminous flux of 850 lumens, the illuminance at a distance of 15 cm from the lighting equipment during energization illumination is 4300 lux, 68 lux 2 seconds after the light source is turned off, 11 lux 30 seconds, 5 lux 1 minute, 2 lux 2 minutes later. 0.5 lux, 2 lux after 5 minutes, and the same condition continued for a long time thereafter. Even after 30 minutes had passed, the surface of the lighting fixture emitted light in the dark, and the display function was performed to the extent that its position could be confirmed.

  According to the present invention, it can be normally used as a general lighting fixture, can function as a short-term emergency lighting at the time of power failure at night, and can further provide a display function for indicating its position. In addition to this, in the present invention, since the excitation time of the light storage is short, it is possible to apply the present invention to an appliance that suppresses power consumption by intermittent lighting in which lighting and extinguishing are repeated. This can reduce power consumption and contribute to energy conservation. Furthermore, it can be used as an emergency lighting device that is installed as a foot light on the road side of an evacuation route that assumes a possibility of a tsunami hit by an earthquake that occurs at night and that assists safe evacuation route guidance when power is lost.

1 Inside the light guide plate
2 Light reflection sheet
3 Hemispherical lenticular projection
4 Light function layer
5 Diffuse reflection layer 7 Phosphorescence initial luminosity by irradiation of high illuminance excitation light 8 Phosphorescence initial luminosity by excitation light illuminance lower than 7 9 Saturation reaching point 10 Excitation spectrum 11 Phosphorescence emission spectrum 12 Phosphorescence luminescence decay at high excitation light illuminance 13 12 Phosphorescence luminescence decay due to excitation light illuminance lower than 14 terms Phosphorescence luminescence decay due to excitation light illuminance lower than 13 terms

Claims (5)

A lighting device comprising a light source and a light guide plate for guiding the light, wherein a convex protrusion is provided on one surface of the light guide plate, and a light-storing diffuse reflection sheet is provided to face the protrusion, A lighting apparatus, wherein the reflection sheet includes a light storage function layer that stores light condensed by the convex protrusion, and a diffuse reflection layer that reflects light transmitted therethrough. A light source, a light guide plate for guiding light from the light source, a convex protrusion provided on one side of the light guide plate, a light storage function layer provided opposite to the protrusion, and a light transmission function layer transmitted through the light storage function layer. A light-diffusing layer for reflecting the reflected light, and condensing the light from the light guide plate to the light-storing function layer at the protrusions. The lighting device according to claim 1 , wherein the convex protrusion provided on one surface of the light guide plate has a hemispherical lens shape . As the phosphorescent material used for the phosphorescent functional layer, a phosphorescent material in which the total energy of light having a wavelength whose excitation spectrum is in the range of 0.38 to 0.49 μm is 20% or more of the total energy of the entire excitation spectrum is used. The lighting fixture according to claim 1 or 3, wherein: The luminous function layer illuminates the surface of the 25 cm square planar luminous function layer with 700 lumens of visible light for 30 seconds, then stops, and stops at a position 15 cm away from the center of the luminous function layer by a vertical line. The lighting device according to claim 1, 3 or 4, wherein the light emitting functional layer has a phosphorescent light emitting ability such that the measured illuminance after 40 seconds is 40 lux or more .

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