JP6454505B2 - Lighting device - Google Patents

Description

  The present invention relates to an illumination device including an illumination filter cover having a function of cutting blue wavelength light emitted from a light source such as a light emitting diode (hereinafter abbreviated as LED).

Conventionally, many lighting devices using LED elements with low power consumption and long life have been proposed. In the illumination device using this LED element, it is known from research that the maximum wavelength that impairs human eyes is a light beam having a wavelength of about 480 nm or less.
There are two effects of blue wavelength light on the human body: (1) influence on the body clock and (2) “light pollution”. With regard to (1), in order to maintain life, people have become the body clock of the rhythm of one day, repeating the cycle of waking up in the morning, eating, working, sleeping at night, from birth to life. However, the use of smartphones and PC terminals regardless of the time, and the life under the white LED, make this body clock come. As a result, many studies have been reported that cause sleep disorders, depression, hypertension, diabetes, and obesity. Regarding (2), since blue wavelength light is light that is easily scattered, image blurring occurs, the load on the eye adjustment function is increased, and eye fatigue occurs. In addition, it is said that blue wavelength light reaches the retina of the human eye, causing retinal damage and causing macular degeneration.

  In addition, the LED element itself has a high directivity of light, is a light source with high brightness and low solid angle, and “glare” that causes discomfort and difficulty in viewing an object particularly when a lighting device is constructed. Therefore, a countermeasure against so-called discomfort glare (dazzle) is required. In recent years, laws and regulations for preventing glare have been established for road traffic and lighting design in some countries and regions. For this reason, it is essential that an illumination device using an LED element has a glare prevention function.

  For example, as disclosed in Patent Document 1, an illumination device having a glare prevention function includes a white light source having an LED element and a light adjustment unit, and the light adjustment unit is emitted from the white light source. For example, glass or acrylic with high light transmittance as a light reducing part that reduces light having a wavelength of at least 470 nm or less, which has little influence on the brightness perceived by humans, to an average of 75% (average transmittance is 75%) There are those provided with a band pass filter coated with ITO (indium tin oxide) and an LED element as a light adding portion having a light emission peak in the range of 480 to 485 nm.

  Further, as disclosed in, for example, Patent Document 2, an illumination device having a function of cutting the blue wavelength light described above includes, for example, an LED light bar or a fluorescent tube in a cylindrical support case made of glass or plastic. A blue wavelength light cut that cuts a part of light with a wavelength of 480 nm or less and converts the cut energy into an antibacterial deodorizing effect by a photocatalytic method on the light emitting surface of the support case. There is a coating made of an antibacterial deodorant layer.

JP, 2014-0117144, A Utility Model Registration No. 3189850

  However, since the surface temperature of the LED element described above reaches about 90 ° C. or higher, the bandpass filter in which ITO (indium tin oxide) is coated on glass or acrylic having high light transmittance in Patent Document 1, and Patent Document 2 Damage to the glass or plastic cylindrical support case of the LED element due to thermal shock from the LED element cannot be ignored.

  In particular, in recent years, plastic lenses have been employed as illumination filter covers. This illumination filter cover is low-cost and difficult to break, can be easily molded by a mold, and a large number of aspheric lenses can be produced. However, when the plastic lens is coated to cut blue wavelength light, a thermal crack (plastic deformation) occurs at an ambient temperature of 60 ° C., and the coating peels off and deteriorates. ing. Incidentally, in the case of a general glass, for example, the glass is broken by a thermal shock generated during a coating process by a heating type vacuum deposition method or the like. In addition, as described above, when the lighting device is used, the surface temperature of the LED element reaches 90 ° C. or more, so that there is a difficulty as a lens for cutting blue wavelength light from the LED element.

  Therefore, the present invention was created in view of the existing circumstances as described above, and can prevent the occurrence of thermal cracks due to environmental temperature and the accompanying peeling and deterioration of the coating, and also for cutting blue wavelength light An object of the present invention is to provide an illuminating device including an illuminating filter cover that can withstand a thermal shock generated during the coating process.

In order to solve the above-described problems, the present invention includes a light source having an LED element and an illumination filter cover that covers the light source, and the illumination filter cover is formed of a heat-resistant glass material. In addition, a spherical lens or an aspherical lens having a blue wavelength light cut coating for reducing a blue light emitting component having a wavelength of 470 nm or less emitted from the light source is formed .

  A reflection plate provided around the light source so as to reflect light emitted from the light source toward the concave surface of the spherical lens or the aspherical lens is included.

  The light source is constituted by an LED substrate formed by arranging a plurality of LED elements, and the illumination filter cover is provided with a heat resistant glass with a blue wavelength light cut coating applied to each LED element of the LED substrate. A spherical lens group or an aspherical lens group made of a material is provided.

  A reflection plate is provided around the LED substrate to reflect light emitted from each LED element toward each concave surface of the spherical lens group or aspheric lens group of the illumination filter cover.

  According to the present invention, it is possible to prevent the occurrence of thermal cracks due to the environmental temperature and the accompanying peeling and deterioration of the coating, and to withstand the thermal shock generated during the coating process for cutting the blue wavelength light. An illuminating device including the filter cover can be provided.

  That is, in the present invention, a light source having an LED element and an illumination filter cover that covers the light source are provided, and the illumination filter cover is formed of a heat-resistant glass material. Since it has a glass transition temperature of 500 to 550 ° C. and a thermal shock of 160 to 180 ° C., when it is used as an illumination device with LED elements, no thermal cracks are generated in the filter cover for illumination itself. It is possible to prevent deterioration of the coating.

  The illumination filter cover is formed by forming a spherical lens or an aspherical lens having a blue wavelength light cut coating for reducing a blue light emitting component having a wavelength of 470 nm or less emitted from the light source. By effectively using, it is possible to efficiently brighten only the local part to be illuminated, and the power consumption can be reduced accordingly. That is, in the present invention, since the blue wavelength light cut coating is applied to the spherical lens or the aspherical lens, the relative radiation intensity in the maximum peak region (wavelength 452 nm) of the light source is cut at least 34% to 50% at maximum. In addition, the combined use of the blue wavelength light cut and the lens function makes it possible to compensate for the amount of light reduced by the blue wavelength light cut by condensing the lens.

  For example, a coating for cutting blue wavelength light applied to spectacles or the like attenuates not only blue light having a wavelength of 470 nm or less, but also other yellow and red light having a long wavelength, and has a cut rate. The higher the amount, the smaller the amount of light that reaches the eyes. In the case of an illumination device using an LED element, the light will be darker, which means that the tip falls. In addition, in the conventional illumination device that does not use the illumination filter cover formed by forming the spherical lens or the aspheric lens, the light spreads (illuminates the wall, not the desk), and does not illuminate the desk effectively. Therefore, in order to illuminate the desk brightly, it is necessary to increase the power consumption and secure the illuminance. On the other hand, in the present invention, by using the lens, it is possible to efficiently brighten only the illuminating place, and accordingly, power consumption can be reduced. It is sufficient to compensate for the decrease in the amount of light that has been cut off with the light consumption.

  Further, if the spherical lens or the aspherical lens is not coated, a problem of light directivity occurs. For example, when the LED element is covered with a coated flat glass instead of a lens, the yellow light is strong just under the LED element, and the light is obliquely white. On the other hand, by using a spherical lens or an aspherical lens as in the present invention, all the irradiation directions become slightly yellow light (dispersion of yellow light), and light color unevenness is eliminated. In addition, in an actual product, yellow light can be reduced by using a glare-preventing cover (for example, rubbed glass) together.

  It includes a reflector attached around the light source to reflect the light emitted from the light source toward the concave surface of the spherical lens or aspheric lens of the illumination filter cover. It can reflect well and irradiate the outside periphery through the spherical lens or aspherical lens of the filter cover for illumination. In addition, it is possible to use a method in which light leaking from the lens is picked up by a reflecting plate and the total amount of light emitted to the outside is compensated.

  The light source is constituted by an LED substrate formed by arranging a plurality of LED elements, and the illumination filter cover is provided with a heat resistant glass with a blue wavelength light cut coating applied to each LED element of the LED substrate. Since the spherical lens group or the aspherical lens group is made of a material, it is an illumination filter that can cover a plurality of LED elements while preventing the occurrence of thermal cracks due to the environmental temperature and the accompanying peeling and deterioration of the coating. An illumination system using a cover can be easily constructed.

  Around the LED substrate, a reflection plate for reflecting the light emitted from each LED element toward each concave surface of the spherical lens group or the aspheric lens group of the illumination filter cover is attached, for example, In a ceiling-embedded illumination device, light from a plurality of LED elements on an LED substrate can be efficiently reflected and irradiated to the outside periphery (periphery below the ceiling) through a spherical lens or an aspheric lens of an illumination filter cover. . In addition, it is possible to use a method in which light leaking from the lens is picked up by a reflecting plate and the entire amount of light applied to the outside periphery (periphery below the ceiling) is compensated.

It is a disassembled perspective view which shows the outline | summary of the illuminating device in one form for implementing this invention. It is a top view which shows the outline | summary of the filter cover for illumination of a lighting device similarly. It is XX sectional drawing of FIG. It is a graph for demonstrating the comparison of the wavelength spectrum of blue wavelength light cut LED illumination, and the conventional LED illumination. It is a figure which shows the relationship between illumination intensity and power consumption in a table | surface. It is a figure which shows the test | inspection result using the test tool which detects a color vision abnormality in a table | surface. It is a figure showing the pattern of color misidentification. It is a figure which shows the evaluation result of the color discrimination under sunlight in a table | surface. It is a figure which shows the investigation result regarding the kind of illumination before a clinical trial in a table | surface.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[Whole structure of lighting device]
As shown in FIGS. 1 to 3, the illumination device according to the present invention includes a light source 3 constituted by an LED substrate 1 in which a plurality of LED elements 2 are arranged, and the light source (LED substrate 1 + LED element 2). ) A spherical or aspherical lens 5 made of a heat-resistant glass material, which is provided with a blue wavelength light cut coating for reducing blue light emission of a wavelength of 470 nm or less so as to cover each LED element 2 of the LED substrate 1 so as to cover 3. The illumination filter cover 4 is generally composed of a group.

[Configuration of light source]
As a specific configuration of the light source 3, as shown in FIG. 1 or FIG. 2, for example, a total of 14 LED elements (LEDs) are formed on a rectangular plate-like LED substrate 1 made of aluminum or glass / epoxy resin, for example. Chips 2 are arranged in two rows of 7 each, and the LED elements 2 in both rows are mounted in a staggered manner, and a current limiting resistor (not shown) is used to reduce the influence of voltage fluctuation (reverse voltage). Or a constant current element (a constant current diode, a reverse connection diode, a constant current IC, or the like) is inserted in series in the LED element 2.

[Configuration of filter cover for lighting]
As shown in FIG. 1 or FIG. 2, the illumination filter cover 4 is formed into a rectangular plate shape from a heat-resistant borosilicate glass (also known as borosilicate glass). Each of the flange portions 7 is formed through a downward step from the front surface side to the back surface side. Thereby, the recessed part 6 for accommodating the said LED board 1 is formed in the back surface side of the filter cover 4 for illumination along the longitudinal direction center. Further, in the center of the recess 6, a total of 14 lenses 5 such as spherical lenses or aspherical lenses are arranged in two rows corresponding to each LED element 2 on the LED substrate 1. These lenses 5 are alternately formed in a staggered pattern. The aspheric lens is, for example, a cylindrical surface, a toric surface, a symmetric aspheric surface, an asymmetric aspheric surface, or the like.

  Borosilicate glass is a glass that has been melted with boric acid and softened, and has a higher temperature and hardness, and its thermal expansion coefficient is about one-third lower than that of ordinary glass. Therefore, the thermal stress due to the temperature difference is reduced and it is strong against thermal shock, and it has excellent heat resistance and chemical resistance. It is called Pyrex from the American Corning trademark. Further, since the atomic weight of boron constituting the heat-resistant glass is small, the density is lower than that of normal glass. Optically, it is a crown glass with small chromatic dispersion (Abbe number of about 65) and low refractive index (1.51 to 1.54 in the visible region).

  Further, as shown in FIG. 3, a blue wavelength light cut coating layer 8 for reducing a blue light emitting component having a wavelength of 470 nm or less and at least about 450 nm emitted from the LED element 2 is provided on the surface of the lens 5 described above. It has been subjected. The blue wavelength light cut coating process may be applied to the back surface of the lens 5 or may be applied to the entire illumination filter cover 4 including the lens 5 group.

  In the periphery of the LED substrate 1 or each LED element 2 or around the recess 6, the light emitted from the LED element 2 is reflected toward the concave surface side of the lens 5 inside the recess 6 of the illumination filter cover 4. A reflector (not shown) is attached. This reflector is made of, for example, aluminum, and is a specular plate whose surface is coated with high-purity titanium and silicon and has a reflectance of 90% or more, and efficiently reflects the light emitted from the LED element 2. Irradiating to the outside through the lens 5 described above.

  In the above-described embodiment, the arrangement form and circuit configuration of the LED elements 2 on the LED substrate 1, the material of the LED substrate 1, the arrangement of the lenses 5 of the illumination filter cover 4, and the like do not limit the present invention. Various other modifications are possible.

  Next, a color identification function when the lighting device according to the present invention is used will be described.

[Clinical results of ABC-LED (blue wavelength light cut) illumination]
In blue wavelength light cut illumination (hereinafter referred to as ABC-LED) and conventional LED illumination (hereinafter referred to as NBC-LED), clinical trials will be conducted mainly on the color discrimination function to verify the visual improvement and marketability.

  The wavelength spectrum of the target light source (horizontal axis: wavelength (nm), horizontal axis: relative radiation intensity) is shown in FIG. In the case of ABC-LED, the cut rate was 34% to 50% at the maximum peak wavelength of 452 nm (indicated by the solid curve of arrow 2 in FIG. 4). In the case of the NBC-LED, the cut rate was 42% at a wavelength of 440 nm (indicated by the dotted curve of arrow 1 in FIG. 4). The wavelength of 380 to 500 nm indicates a blue wavelength light wavelength region. The experiment was conducted under practical lighting with a cut rate of 34%.

  In addition, about 12 people (11 men, 1 woman) with near vision acuity 0.7 or more in the subject's 20-60s, color name table and color vision test under sunlight (temperature 24-25 ° C, humidity) 60%). As an inspection method, NBC-LED and ABC-LED light sources are installed on the ceiling in the same room, and only one of the light sources is turned on, and the color name table and color vision inspection (panel D-15) Carried out. In this case, the ceiling height of the room was 2.95 m, the lighting device was embedded in the ceiling, the desk height was 45 cm, and external light was blocked. As shown in FIG. 5, the NBC-LED has a desk illuminance of 900 [lx] and power consumption of 120 W, and the ABC-LED has a top illuminance of 900 [lx] and power consumption of 75 W. In other words, the JIS illuminance standard (visual work) is 750 to 1500 [lx] when there is no influence of daylight, and the power consumption is the power consumption because the lens is used in the case of ABC-LED and the illuminance directly below becomes high. Was adjusted to adjust the illuminance.

  The LED currently on the market looks white light at first glance, but contains blue light that affects the rhythm of the eyes and the body (see FIG. 4). Since blue light is particularly harmful to the eyes, an LED that cuts off this blue light is required, but as an LED that cuts off blue light, it is not on the market and only about 10% is cut by wearing glasses. Is possible. Therefore, we developed original LED lighting that cuts blue light, and worked on the creation of an LED lighting device that is safe for human eyes. As a result, it was possible to create an LED lighting device that cuts 34% to a maximum of 50% by applying a coating that cuts blue light on the spherical glass.

  However, when the blue light is cut, the illumination light becomes yellowish. However, since this light has a yellowish color similar to sunlight, a color discrimination test was performed in order to make it a point that ABC-LED does not cause color misidentification and is close to natural light. The product name of the blue wavelength light cut LED is ABC-LED (A is A class, B is BlueLight blue wavelength light, and C is Cut cut). Since the conventional thing does not cut blue wavelength light, it was set as Non BlueLight Cut (NBC-LED).

  In addition, a yellowish gemstone called citrine is called a stone that symbolizes the sun, and we examined the naming of citrine LED with the hints of health and sleep that bring wealth and prosperity, such as the meaning and auspiciousness of the stone. We decided to put a stone on the market, including a unique expression method such as “Citrine White” in the expression of the color temperature of illumination light (Both ABC-LED and Citrine LED are registered trademarks) .

[Result of panel D-15]
As shown in FIGS. 6 and 7, color misperception occurred in NBC-LEDs in 2 out of 11 color-blind normal persons. In ABC-LED, no color misidentification was observed in all cases. In addition, the subject A in whom the first color vision abnormality was seen was excluded. In addition, the color name table was used to check whether the actual color appearance was different between the two types of LEDs. The color name table is a basic color swatch that is used to select colors in which all colors are sampled in detail based on lightness and saturation. The actual color (green peppers, red / yellow peppers) was selected from the color table under two types of LED lighting. If there were no identical colors, we asked them to choose a similar one. As a result, there was almost no difference between ABC-LED and NBC-LED. That is, it was recognized that there was no difference in color appearance under ABC-LED illumination even when the actual product was seen.

[Results of Color Discrimination by Color Name Table (DIC Corporation: DIC COLOR GUIDE Ver. 19)]
For the purpose of demonstrating that there is no effect on the appearance of the actual color by cutting off the blue wavelength light, all the subjects are shown red, green, and yellow peppers, and a similar color number is selected from the color name table. I received it. The similar level was evaluated in three stages (1: somewhat close, 2: almost close, 3: -match). In addition, about yellow, the above was performed with the yellow pen for subjects A-D and yellow paprika for subjects E-L. As a result, in the color discrimination ability by each color, the number of subjects who chose red: same color is 5 for ABC-LED and 6 for NBC-LED. Green: 6 people with ABC-LED and 6 people with NBC-LED. Yellow: Same-colored subjects are 2 for ABC-LED and 2 for NBC-LED. There was one more subject who chose the same color for red only. From this result, there was no particular difference between the two LEDs.

[Color discrimination under sunlight]
When the following two people were discriminated under the sunlight, characteristic results (shown in FIG. 8) were obtained. In green discrimination (20's), dark green was selected under NBC-LED illumination, but light green was selected under ABC-LED and sunlight. Moreover, in the yellow discrimination (20's), the result was that the same color (NO. 165) was selected for both ABC-LED and sunlight (both level 3). However, this is a preliminary experiment for the next clinical trial, and since there are two subjects, this result is not a conclusion.

  Panel D-15 is an international reference tool for detecting color blindness in the ophthalmic field. Since ABC-LEDs seemed to have a yellowish color at first glance, they were inspected with internationally used inspection equipment to check for color misunderstandings. In this result, NBC-LED detected color misidentification in 2 out of 11 people, and the developed ABC-LED did not have color misidentification, and a better result than expected was obtained.

[Result of questionnaire survey]
Prior to the clinical trial, the near vision, subjective symptoms related to the eyes, and the type of lighting used at home were interviewed (see FIG. 9).

[Impression of ABC-LED and NBC-LED]
(Overall impressions) During the trial, I was asked to look at books and PC screens and interviewed the impressions they received. Eleven out of twelve felt that ABC-LED lighting was darker. The other one (20's) felt that the brightness was just right and the impression that the NBC-LED was too bright. Eleven of the 12 responded that ABC-LED lighting was more calm and soft. One other person (30's) replied that NBC-LEDs are more calm. 6 out of 8 people who showed the PC screen were not much different. Two other people (10's and 20's) replied that the ABC-LED was easier to see in the white background. Three of the eight people who showed the book (two in their teens and one in their 20s) can easily see the characters on the ABC-LED. One of these three people (in his 20s) felt dazzled by the NBC-LED. Also, if the NBC-LED characters were easier to see, the respondent (30's) would be flickering when reading the characters with the ABC-LED illumination. The above is a preliminary experiment for demonstrating the superiority of ABC-LED, and the number of cases and accuracy are examined and added as this trial.

[Summary]
The blue wavelength light-cut ABC-LED illumination in the present embodiment is more yellowish than the general blue wavelength light-cut NBC-LED illumination, so it is not preferred for color viewing or illumination light. I was worried that it might be. Therefore, this time, the visual functional evaluation was performed with respect to the color discrimination ability in particular, and the actual color discrimination ability was performed with the color name table on panel D-15. From the panel D-15 clinical trial results, it is considered that no error occurs under ABC-LED illumination, and that there is less risk of color discrimination when compared with NBC-LED illumination. Further, from the clinical trial results of the color name table, the tendency of selecting dark colors (green, yellow) for NBC-LEDs and light colors for ABC-LEDs was noticeable in the 30-40s. In clinical trials of color discrimination under sunlight, it was suggested that ABC-LED illumination is close to sunlight. In everyday life, ABC-LED is a yellowish illumination light compared to conventional LEDs, so it was feared whether it could be used favorably, but ABC-LED was slightly darker than NBC-LED, but ABC-LED was 12 Since one person (11 persons) in the name answered that it was soft light and calm, it is considered that it is preferred for use at home and is marketable. The impression of darkness can be solved by increasing the illuminance.

DESCRIPTION OF SYMBOLS 1 ... LED board 2 ... LED element 3 ... Light source 4 ... Illumination filter cover 5 ... Lens (spherical lens or aspherical lens)
6 ... Recess 7 ... Flange 8 ... Blue wavelength light cut coating layer

Claims (4)

A light source having an LED element; and an illumination filter cover covering the light source. The illumination filter cover is made of a heat-resistant glass material, and emits a blue light emitting component having a wavelength of 470 nm or less emitted from the light source. An illumination device comprising a spherical lens or an aspherical lens to which a blue wavelength light cut coating for reduction is applied .   The illuminating device according to claim 1, further comprising a reflector attached around the light source so as to reflect the light emitted from the light source toward the concave side of the spherical lens or the aspheric lens.   The light source is constituted by an LED substrate formed by arranging a plurality of LED elements, and the illumination filter cover is provided with a heat resistant glass with a blue wavelength light cut coating applied to each LED element of the LED substrate. 2. The illumination device according to claim 1, wherein a spherical lens group or an aspherical lens group made of a material is provided. 4. A reflecting plate for reflecting light emitted from each LED element toward each concave surface of the spherical lens group or aspherical lens group of the illumination filter cover is provided around the LED substrate. Lighting equipment.