JP2023057381A - Lighting device for lighting color display - Google Patents

Abstract

To provide a lighting device for lighting a color display that easily reduces eye fatigue and improves visibility by adjusting the color of light generated from a color display of information terminal equipment.SOLUTION: A lighting device for lighting a color display is used for dimming a color display of information terminal equipment and has a light source portion composed of a plurality of LED devices.SELECTED DRAWING: Figure 1

Description

The present invention relates to an illumination device for illuminating color displays.

In recent years, information terminal devices such as smartphones, tablet type information terminal devices, car navigation devices, laptop computers, game devices, and vehicle instrument panels that allow people to see information displayed on the screen have rapidly spread. and permeates our lives.

For example, in the use of smartphones, people turn off the room lights at night and look at the screen of the smartphone until just before going to bed, browse Internet sites, and use social media network services.

By the way, the human retina has photoreceptors that sense light. It has been known that the vision of image formation, such as light and dark vision, color vision, morphology, and kinesthetic vision, which is generally called vision, is perceived by cones and rods, which are photoreceptors present in the retina. On the other hand, in recent years, in addition to image-forming vision, attention has been paid to non-image-forming vision. Non-image-forming vision is vision that is not image-forming vision that affects circadian rhythms, such as sleep-wake rhythms. Such non-image-forming vision is mediated by intrinsic photosensitive retinal ganglion cells (ipRGCs), a novel photoreceptor distinct from cones and rods discovered on the mammalian retina in 2002. Recognized based on discovery. ipRGCs are non-imaging vision, ie, photoreceptors that sense light involuntarily.

The photoreceptors of the retina, cones, rods and ipRGCs, contain visual substances, proteins called opsins that change color in response to light. The visual substance is a substance that changes color when it receives light, and the color change senses the presence of light and transmits the signal to the brain. Visual substances contained in cone cells have absorption peaks at 559 nm for sensing red, 531 nm for sensing green, and 419 nm for sensing blue. In addition, visual substances contained in rod cells have an absorption peak at 496 nm. The perception of light by these visual substances is transmitted as a signal to the visual cortex of the cerebral cortex.

On the other hand, ipRGC has a special visual substance called melanopsin, which is a type of opsin with a peak absorption wavelength of 484 nm. It is known to make you feel better.

Further, in recent years, in lighting using LED devices, lighting that does not easily give people a feeling of fatigue has also been researched. For example, Patent Document 1 below describes a light source that emits light that gives a bright feeling in a dark place, provides high visibility, and does not cause fatigue. , 0.33), the line segment WB connecting the 480 nm coordinate B (0.091, 0.133) and the 560 nm coordinate G (0.373, 0.624) on the spectrum locus, and the color purity in the region surrounded by the line segment WG and the spectrum locus. 2 to 50, and the area occupied by continuous spectral wavelengths in the wavelength region of 480 to 540 nm is 15% or more of the spectral wavelength area of the entire light source of 380 to 780 nm. .

Further, Patent Document 2 below discloses an illumination device capable of enhancing the visibility of characters on a display without giving a sense of discomfort to a user during visual work in an office or the like. Specifically, in a lighting device including a light emitting unit, when the lighting device is installed on the ceiling and the direction directly below the light emitting unit is assumed to have a vertical angle of 0°, the vertical angle of the illumination light emitted from the lighting device is The color of the first light emitted in the direction of 0° is 0.7125u'+0.3284<v'< In the range of 0.7125u'+0.3339, the second light emitted in the range of a predetermined vertical angle or more among the illumination light emitted from the lighting device has a higher correlated color temperature than the first light. Disclose the device.

Further, Patent Literature 3 listed below discloses an illumination device capable of improving readability of characters on a display. Specifically, a light emitting unit that emits the first illumination light is provided, and the light characteristics of the first illumination light are such that the correlated color temperature is in the range of 3800 K or more and 6500 K or less, and the color deviation Duv is in the range of -9 or more and 0 or less. , an illumination device for a display, wherein the intrinsic photosensitive retinal ganglion cell (ipRGC) stimulation level is 0.6 or more as a value normalized by light emitted from a D65 light source.

Moreover, the following patent document 4 discloses the lighting device which can improve a feeling of whiteness and can improve visibility. Specifically, a light source having a solid-state light-emitting element is provided, and the light source has a correlated color temperature in the range of 5400K to 7000K, a color deviation in the range of Duv-6 to 8, and conforms to The CIE 1997 Interim Color Appearance Model (Simple Version ), which has a spectral radiation characteristic in which the chroma value obtained using the calculation method defined in ) is 2.7 or less.

In addition, Patent Document 5 below discloses an illumination device that suppresses the elderly from feeling glare and suppresses the deterioration of color saturation of characters and observation objects for the elderly. Specifically, it comprises a first light source module and a second light source module surrounding the first light source module, wherein the 1/2 beam angle of the first light source module is larger than the 1/2 beam angle of the second light source module. A lighting device is disclosed that is small and the correlated color temperature of the light emitted by the first light source module is higher than the correlated color temperature of the light emitted by the second light source module.

JP 2019-125577 A JP 2019-096573 A JP 2018-088374 A JP 2014-075186 A JP 2017-157485 A

Color displays of information terminal equipment use three primary colors (RGB) of red (R), green (G), and blue (B) as pixels, and by mixing those colors, all colors can be displayed in full color. are reproduced. Each color reproduced by such full color includes a respective sharp peak of RGB to stimulate the visual perception of image formation. Such sharp peaks are necessary for perceived color reproduction in image forming vision. On the other hand, such a color display tends to cause eye fatigue because the human eye is stimulated only by light of a specific wavelength.

In order to solve the above-described problems, the present invention illuminates a color display that easily reduces eye fatigue and improves visibility by adjusting the color of the light emitted from the color display. An object of the present invention is to provide a lighting device for

One aspect of the present invention is an illumination device for illuminating the color display, which is used for dimming the color display of information terminal equipment, and which includes a light source unit composed of a plurality of LED devices. According to such a lighting device for illuminating a color display, for example, by mixing the light from the color display with the light emitted from the light source section of the lighting device, the spectral distribution characteristics and illuminance of the color display visually recognized by the user can be changed. can be adjusted. As a result, for example, by emphasizing light of a wavelength that stimulates non-image-forming vision, which is hardly included in the luminescent color of a color display, even dark light can be made to feel brighter, or the correlated color temperature can be shifted to a lower color temperature. It is possible to reduce glare, which is an unpleasant glare, to reduce eye fatigue and improve visibility, and to adjust the emission color of the color display to a color according to the purpose such as to make it visible. Such an illumination device preferably further includes an illumination fixture for projecting light emitted from the light source toward the color display. Examples of information terminal equipment include smart phones, tablet information terminal equipment, car navigation equipment, notebook personal computers, instrument panels, and the like.

Further, the light emitted from the light source has a first peak indicating the maximum emission intensity in the wavelength range of 420 to 480 nm. It preferably exhibits an emission spectrum with a relative emission intensity in the range of 0.2 to 0.7 over the entire wavelength range and in the range of 0.5 to 0.9 over the entire wavelength range of 560 to 630 nm. According to a lighting device exhibiting such an emission spectrum, when a person views a full-color display in a dark environment, the wavelength of 490 to 520 nm stimulates non-image-forming vision, which is hardly included in the emission colors of the color display. By increasing the amount of light, even dark light can be felt bright, and even a light source with low illuminance can make the screen of a color display easy to see. In addition, by increasing the amount of light with a wavelength of 560 to 630 nm, the correlated color temperature of light emitted from the color display can be shifted to a lower color temperature, and glare, which is unpleasant glare, can be reduced. This reduces eye fatigue and improves visibility for those who view the color display.

Further, the plurality of LED devices each include at least one first LED device and at least one second LED device, and the first LED device has a maximum emission intensity in a wavelength range of 560 to 660 nm. When the relative emission intensity of the second peak is 1.0, the maximum relative emission intensity at a wavelength of 420 to 480 nm is 0.4 to 0.8, and in the entire wavelength range of 490 to 520 nm In the range of 0.2 to 0.7, the second LED device has a third peak indicating the maximum emission intensity in the wavelength range of 420 to 480 nm. When the emission intensity is 1.0, the relative emission intensity is in the range of 0.2 to 0.7 in the entire wavelength range of 490 to 520 nm, and in the range of 0.3 or more in the entire wavelength range of 520 to 580 nm. It preferably exhibits an emission spectrum having By mixing the light from the combination of the first LED device and the second LED device with the light from the color display as illumination for illuminating the color display in this way, the person viewing the color display does not experience eye fatigue. This makes it easier to obtain a lighting device that can easily reduce .

Further, the first LED device includes a first blue LED element, and a fluorescence peak wavelength with a half width of 80 to 120 nm in a wavelength range of 490 to 530 nm, which is excited by light emission of the first blue LED element and emits fluorescence. and a second phosphor having a fluorescence peak wavelength of 100 to 130 nm half-value width in the wavelength range of 510 to 580 nm, and a fluorescence peak wavelength of 60 to 100 nm in the wavelength range of 580 to 680 nm. and a third phosphor.

Further, the second LED device includes a second blue LED element and a fluorescent peak wavelength of 100 to 130 nm in the wavelength range of 510 to 580 nm, which emits fluorescence when excited by light emission of the second blue LED element. and a fourth phosphor having a fluorescence peak wavelength with a half width of 50 to 80 nm in the wavelength range of 430 to 490 nm.

According to the present invention, it is possible to obtain an illumination device for illuminating a color display that easily reduces eye fatigue and improves visibility by adjusting the color of light emitted from the color display.

FIG. 1 is an explanatory diagram showing a state when the lighting device 10 of the present embodiment is attached to the smartphone 100. As shown in FIG. FIG. 2 is a schematic plan view of a light source module 3 composed of a plurality of LED devices 1a and 1b containing phosphors. FIG. 3 is an explanatory diagram illustrating how the illumination device 10 projects light onto the color display 101 of the smartphone 100. As shown in FIG. FIG. 4 is an explanatory diagram for explaining how the position of the light source 5 of the illumination device 10 is changed to change the irradiation area. FIG. 5 is an explanatory diagram of a lighting device 20 according to another embodiment. FIG. 6 is an explanatory diagram of a lighting device 30 according to another embodiment. FIG. 7 is an explanatory diagram of a lighting device 40 according to another embodiment. FIG. 8 is an explanatory diagram of a lighting device 50 according to another embodiment. FIG. 9 is a schematic front view showing a state in which an illumination device 60 of another embodiment is attached to a color display 110 of car navigation equipment. FIG. 10 is a schematic explanatory diagram for explaining the layer structure when the illumination device 60 is arranged on the color display 110 of the car navigation device. FIG. 11 shows the emission spectrum of each lighting device obtained in the example of the lighting device of the present embodiment. FIG. 12 is a schematic plan view of an LED device 200 that constitutes the light source of the illumination device of this embodiment. FIG. 13 is a schematic cross-sectional view of the LED device 200 of FIG. 12 taken along line BB'. FIG. 14 shows the spectral distribution of each screen display when different types of screen displays (display screens A to D) are displayed on the color display of the smartphone. FIG. 15 is an explanatory diagram illustrating a method of measuring illuminance and color coordinates of a color display.

The lighting device of this embodiment is used for dimming color displays of information terminal devices such as smartphones, tablet information terminal devices, car navigation devices, laptop computers, or instrument panels. An illumination device for illuminating a color display comprising a light source unit configured as described above.

As an example of the lighting device according to the present invention, as a first embodiment, several embodiments of a lighting device for illuminating a color display of an information terminal device will be described in detail as representative examples.

1A and 1B are explanatory diagrams showing a state in which the lighting device 10 of the present embodiment is attached to a smartphone 100, which is an information terminal device, where (a) is a front view and (b) is a right side view. A smartphone 100 includes a color display 101 that presents various information in full color.

In FIG. 1, reference numeral 10 denotes an illumination device including a light source unit 5 and an illumination fixing unit 2 for projecting light emitted from the light source unit 5 toward a color display 101 . The light source unit 5 accommodates a light source module 3 in which two types of LED devices 1a and 1b having different emission spectra are arranged as shown in FIG. It is The illumination device 10 also includes an illumination fixing portion 2 for holding the upper portion of the housing of the smartphone 100 and fixing the light source portion 5 in order to project light emitted from the light source portion 5 toward the color display 101. . Although the light source module 3 of this embodiment is a structure in which two types of LED devices 1a and 1b are arranged, instead of such a light source module, a plurality of LED devices of only one type are arranged. A module or a light source module in which a plurality of LED devices of three or more types are arranged may be used.

The light source module 3 shown in FIG. 2 is an LED device structure in which three LED devices 1a and 1b of two types are alternately mounted on a surface-mounted circuit board 3a for mounting the LED devices. A power supply circuit (not shown) is formed on the surface mount circuit board 3a to supply power controlled to a predetermined current amount to the LED devices 1a and 1b. The power supply circuit adjusts the amount of current supplied to each LED device 1a, 1b to control the brightness. The amount of current supplied to each LED device is not particularly limited, but it is preferably 1 to 200 mA, or 2 to 150 mA, or further 3 to 100 mA, and the current value is controlled according to the required brightness of the illumination light. The amount of current can be appropriately changed by controlling the resistance and the resistance. Also, the brightness of illumination light may be controlled by pulse-controlling the lighting of each LED device.

Then, the LED devices 1a and 1b are lit by receiving power of a predetermined amount from the power source 4 through the power supply circuit. The power source 4 is not particularly limited, and may be a lithium ion battery or a battery such as a primary battery that is charged by receiving power from a USB terminal, which is housed in the lighting device 10 , or a battery that is housed in the smartphone 100 . A battery may be used as the power source, or a 100 V power source that receives power from a household outlet may be used, and is not particularly limited.

FIGS. 3A and 3B are explanatory diagrams illustrating a state when the lighting device 10 projects light onto the color display 101 of the smartphone 100, where (a) is a front view and (b) is a right side view.

As shown in FIG. 3, the illumination device 10 of the present embodiment emits light from two types of LED devices 1a and 1b that are powered by a light source unit 5 that accommodates a light source module 3, and emits light from the color display 101. Used to project light towards According to such a lighting device 10, by adjusting the light emission from the light source unit 5 according to the purpose, the light emission from the color display 101 is mixed with the light emission from the light source unit 5, thereby obtaining a desired color. It is possible to make a person visually recognize the screen which has been dimmed. Specifically, for example, light emitted from the color display 101 is dimmed to prevent glare by shifting the correlated color temperature to a lower color temperature to reduce unpleasant glare, or to reduce eye fatigue. It can be reduced, improved visibility, or dimmed to a color that does not interfere with falling asleep or to a color that wakes you up.

In the lighting device, it is preferable to be able to adjust the area of the light irradiated to the color display according to the size and arrangement of the color display. In the illumination device 10 shown in FIG. 1 , the illumination fixing unit 2 sandwiches the upper part of the housing of the smartphone 100 and projects light emitted from the light source unit 5 toward the color display 101 . In such a lighting device 10, as shown in FIG. , is preferable in that the area of light irradiated to the color display 101 can be adjusted.

Moreover, FIG. 5 is explanatory drawing of the illuminating device 20 of other embodiment. The lighting device 20 includes a clamping base 12a that clamps the upper portion of the housing of the smartphone 100, and a lighting fixture 12 that includes a lighting support 12b that detachably supports the light source unit 5 on the clamping base 12a using a magnet or the like. . According to such a lighting device 20, when not in use, it is preferable from the viewpoint of facilitating carrying by removing the lighting support portion 12b from the clamping base portion 12a. Moreover, FIG. 6 is explanatory drawing of the illuminating device 30 of other embodiment. The illumination device 30 also has a structure such that the illumination fixing portion 22b to which the light source portion 5 is joined can be detached from the illumination fixing base portion 22a by a slide rail when not in use.

Also, FIG. 7 is a schematic explanatory diagram of a lighting device 40 of another embodiment. The illuminating device 40 has an illuminating fixing portion 32 having a flexible portion 32b that can be deformed by bending, and is connected to a holding base portion 32a. , has the same configuration as the illumination device 10 . Thus, when the light source unit 5 is fixed via the flexible portion 32b, the flexible portion 32b can be moved to freely adjust the area where the color display 101 is irradiated with light. It is preferable from the point that

Moreover, FIG. 8 is explanatory drawing of the illuminating device 50 of other embodiment. The illumination device 50 includes an illumination fixture 42 having a reflective member 43 connected to a clamping base 42a. A light source module 3 in which two types of LED devices 1a and 1b are arranged, and a light source section 45 having a reflecting member 43 are provided. In the illumination device 50, the light source section 45 has a reflecting member 43, and light emitted from the two types of LED devices 1a and 1b is reflected and mixed inside the reflecting member 43, thereby providing a color display as indicated by an arrow. Light is distributed on the surface of 101 .

The embodiment of the lighting device used for adjusting the light color of the color display of the smartphone 100 has been described above. Note that each of the lighting devices described above can be similarly applied to a tablet-type information terminal device instead of a smart phone.

In addition, FIG. 9 shows that the lighting device 60 of the present embodiment reduces eye fatigue and improves visibility for a person viewing a color display of a car navigation device. 110 is a schematic front view showing the state when attached to 110. FIG. FIG. 10 is a schematic explanatory diagram for explaining the layer structure when the lighting device 60 is arranged on the color display 110 of the car navigation device.

The car navigation device has a color display 110 that presents various information in full color. The color display 110 is surrounded by the frame of the housing. A lighting device 60 is attached to the frame with adhesive or the like, or with screws, nuts, suction cups, or the like.

In FIGS. 9 and 10, 60 is an illumination device including a light source unit 55 and an illumination fixing unit 52 which is a light guide plate for projecting light emitted from the light source unit 55 toward the color display 110. FIG. The light source unit 55 is integrated with the light source module 3 in which a plurality of LED devices are arranged so that light is incident from one side surface of a light guide plate made of a molded transparent material such as silicone resin or acrylic resin.

A light source module is configured by, for example, mounting a plurality of LED devices on a surface-mounted circuit board. A power supply circuit (not shown) for supplying power to each LED device is formed on the surface-mounted circuit board. Power is supplied from the power supply through the power supply circuit, and the LED device is lit and emits light. The power supply is not particularly limited, and even a battery such as a lithium ion battery or a primary battery that is charged by receiving power from a USB terminal, which is housed in the lighting device 60, has a basic voltage of 12 v. Alternatively, power may be supplied from a 24v cigar socket.

The embodiment of the lighting device used for adjusting the light color of the color display 110 of the car navigation device has been described above. Each of the lighting devices described above can be similarly applied to a color display of a notebook computer or an instrument panel in place of the color display 110 of a car navigation device.

The light emission of the lighting device of the present embodiment is not particularly limited, but the light emission from the light source unit has a first peak indicating the maximum emission intensity in the wavelength range of 420 to 480 nm, and the relative emission intensity of the first peak. When is 1.0, the relative luminous intensity is in the range of 0.2 to 0.7 in the entire wavelength range of 490 to 520 nm, and in the range of 0.5 to 0.9 in the entire wavelength range of 560 to 630 nm. It is particularly preferred to exhibit an emission spectrum with

FIG. 11 shows the emission spectrum of the lighting device obtained in the example described later, according to the lighting device of the present embodiment. In FIG. 11, a spectrum that satisfies the above preferable conditions is shown as an example of the illumination device D1.

In the spectrum of illumination device D1, 11 is the first peak indicating the maximum emission intensity in the wavelength range of 420 to 480 nm, and the relative emission intensity is 1.0. A point 12a indicates the minimum emission intensity in the wavelength range of 490 to 520 nm, and a point 12b indicates the maximum emission intensity in the wavelength range of 490 to 520 nm. A point 13a indicates the minimum emission intensity in the wavelength range of 560 to 630 nm, and a point 13b indicates the maximum emission intensity in the wavelength range of 560 to 630 nm.

As exemplified as the illumination device D1 in FIG. 11, when the relative emission intensity at the first peak wavelength is 1.0, it is 0.2 to 0.7, further 0.3 in the entire wavelength range of 490 to 520 nm. By illuminating a full-color display with light having a relative emission intensity in the range of ~0.6, particularly 0.4 to 0.6, it makes people feel bright even in dark light, and the illuminance is low. Even if it is a light source, it is preferable because it makes the screen of the color display easy to see. Further, when the relative emission intensity at the first peak wavelength is 1.0, it is 0.5 to 0.9, further 0.6 to 0.85, particularly 0.7 in the entire wavelength range of 560 to 630 nm. Illuminating a color display with light having a relative luminous intensity in the range of ~0.85 shifts the correlated color temperature of the emission of the color display to a lower color temperature resulting in unpleasant glare. This is preferable because it can reduce glare. This reduces eye fatigue and improves visibility for those who view the color display. In addition, according to a lighting device exhibiting such an emission spectrum, the visibility of a color display can be significantly improved, especially in a dark environment.

At the color temperature of CIE1931, an average display screen displayed by a general full-color display has a correlated color temperature exceeding 7000K and emits light with high glare that gives unpleasant glare. Using the illumination device of the present embodiment, a color display can be achieved with an illumination device that emits light of a spectrum having a relative emission intensity in the range of 0.5 to 0.9 in the entire wavelength range of 560 to 630 nm as described above. In particular, the color temperature of the color display can be lowered to, for example, less than 7000K, so that glare, which is an unpleasant glare, can be suppressed.

The illumination device of the present embodiment includes, for example, the light source section, which is an LED device structure formed by mounting at least two LED devices on a surface-mounted circuit board, as described above. At least two LED devices included in such a light source unit may be a combination of a plurality of LED devices of only one type exhibiting similar emission spectra, or a plurality of LED devices exhibiting different emission spectra. They may be combined individually, and are appropriately selected according to the desired illuminance and irradiation area of the application. The number of at least two LED devices mounted in the lighting device is practically preferably in the range of, for example, 3 to 30, more preferably 5 to 20.

Each of the LED devices constituting the at least two LED devices includes a phosphor-containing LED device in which a blue LED device including a blue LED element is combined with a phosphor as described later, and has the characteristics described above. It is preferable from the point that it is easy to manufacture a lighting device. Next, a representative example of a phosphor-containing LED device mounted in such a lighting device will be described with reference to the drawings.

FIG. 12 is a schematic plan view of an LED device 200 that constitutes the light source of the illumination device of this embodiment. 13 is a schematic cross-sectional view of the LED device 200 of FIG. 12 taken along line BB'. 12 and 13, an LED device 200 according to the present embodiment includes a phosphor layer containing an LED device body 205 including a blue LED element 201, a phosphor 203, and a light diffusion material blended as necessary. This is an LED device manufactured so as to be covered with a phosphor-containing cap 209 of .

As shown in FIG. 13, the LED device main body 205 includes a blue LED element 201 that exhibits the maximum emission intensity in the wavelength range of 420 to 480 nm, a package member 202 that includes a recess 202a that accommodates the blue LED element 201, and the recess 202a. It is a blue LED device provided with a transparent resin encapsulant 204 that encloses a blue LED element 201 housed therein.

The blue LED element 201 emits light having an emission peak in the blue region with a wavelength of 420-480 nm. Since the LED device main body 205 includes the blue LED element 201, it forms a first peak showing the maximum emission intensity in the wavelength range of 420 to 480 nm. A blue LED element can obtain high luminous efficiency of a phosphor and is excellent in long-term reliability.

Blue LED elements include gallium nitride (GaN)-based blue LED elements. Further, the transparent resin sealing material seals and seals the blue LED element housed in the recess. Examples of the transparent resin that forms the transparent resin encapsulant include silicone resin, epoxy resin, and acrylic resin. The LED device main body 205 of this embodiment is of a type called a surface mount device (SMD), but in place of the SMD, other types such as a so-called shell type, package type, chip-on-board type (COB type), etc. may be used.

A reflective film 207 made of silver plating or the like may be formed on the inner wall surface of the concave portion 202a of the LED device main body 205 . One electrode of the blue LED element 201 is connected to a lead 202b, and the other electrode of the blue LED element 201 is wire-bonded with a gold wire 206, connected to a lead 202c, and extended to the outside. Lead 202b is the anode and lead 202c is the cathode. By connecting the positive electrode side of the power source to the lead 202c of the LED device main body 205 and the negative electrode side of the power source to the lead 202b and applying power, the blue LED element 201 emits light. In such an LED device main body 205, the upper surface of the transparent resin encapsulant 204 serves as a light emitting surface. A phosphor-containing cap 209 is attached so as to cover the light emitting surface of the LED device main body 205 .

The phosphor-containing cap 209 is a cap-shaped molded body formed by molding a phosphor sheet in which a phosphor that emits fluorescence when excited by the light emission of the blue LED element is blended with a light-transmissive resin. Specific examples of the light-transmissive resin include silicone rubber (silicone elastomer) and silicone resin.

Further, as phosphors, for example, europium-activated strontium aluminate (SAE)-based phosphors: lutetium-aluminum-garnet phosphors and LuAG (LAG)-based phosphors such as cerium-activated lutetium-aluminum-garnet phosphors; Silicate phosphors such as chlorosilicate phosphors; Yttrium aluminum garnet (YAG) phosphors such as cerium-activated yttrium aluminum garnet phosphors; Aluminate phosphors; β-SiAlON: Eu (sialon phosphor); Nitriding Material-based phosphors; cousin-based (CASN)-based phosphors such as (Sr, Ca)CaAlSiN ₃ :Eu and CaAlSiN ₃ :Eu.

In particular, in order to obtain a phosphor-containing LED device exhibiting an emission spectrum in the range of 0.2 to 0.7 in the entire wavelength range of 490 to 520 nm, the half width in the wavelength range of 490 to 530 nm should be 80 to 80. It is preferable to incorporate a LAG-based phosphor having a fluorescence peak wavelength such as 120 nm.

In particular, in order to obtain a phosphor-containing LED device exhibiting an emission spectrum in the range of 0.5 to 0.9 in the entire wavelength range of 560 to 630 nm, the half width of 60 in the wavelength range of 580 to 680 nm is required. It is preferable to incorporate a CASN-based phosphor having a fluorescence peak wavelength such as ~100 nm.

Further, a YAG-based phosphor having a fluorescence peak wavelength of 100-130 nm half-value width in the wavelength range of 510-580 nm, and an SAE having a fluorescence peak wavelength of 50-80 nm half-value width in the wavelength range of 430-490 nm. It is preferable to adjust the emission spectrum by blending a system phosphor or the like.

In addition, it is preferable to add a light diffusing material to the phosphor-containing cap in order to efficiently excite the phosphor in the phosphor-containing cap by diffusing the light of the blue LED element with a wavelength of 420 to 480 nm. Examples of such light diffusion materials include silica and calcium carbonate.

Further, the phosphor-containing cap may optionally contain a coloring material as a component for adjusting the emission color by absorbing light of a predetermined wavelength. Specific examples of such coloring materials include organic or inorganic pigments such as green pigments such as chrome green, chromium oxide, pigment green B, malachite green lake, final yellow green G, and phthalocyanine green. In addition, in order to adjust the brightness of the entire light source, white pigments such as titanium oxide, talc and barium sulfate, and black pigments such as carbon black can be used together. These may be mixed with the phosphor, or may be blended by providing a layer containing no phosphor.

Alternatively, instead of the phosphor-containing cap described above, a flat phosphor sheet containing a phosphor may be adhered, or a phosphor-containing LED device may be formed by providing a phosphor layer containing a phosphor on the light-emitting surface of the LED device main body. may be manufactured. The phosphor layer may be in the form of a film formed on the surface of the blue LED element or formed inside or on the surface of the transparent resin encapsulant by coating or printing. Especially when the phosphor layer is in the form of a film formed on the surface of the transparent resin encapsulant, fine adjustment of the amount of the phosphor and light color adjusting agent blended in the phosphor layer, and the spectral wavelength and emission intensity. , is preferable from the viewpoint of facilitating the manufacture of the LED device. Further, in the phosphor-containing LED device, instead of forming a phosphor layer, the phosphor may be dispersed in a transparent resin sealing material that seals the blue LED element.

As described above, when the light emitted from the light source unit has a first peak indicating the maximum emission intensity in the wavelength range of 420 to 480 nm, and the relative emission intensity of the first peak is 1.0, the wavelength is 490 A lighting device exhibiting an emission spectrum having a relative emission intensity in the range of 0.2 to 0.7 over the entire range of ~520 nm and in the range of 0.5 to 0.9 over the entire wavelength range of 560 to 630 nm, For example, it can be manufactured more simply as follows.

As an example, referring to FIG. 11, illumination device D2 has a second peak 14 exhibiting a maximum relative emission intensity of 1.0 in the wavelength range of 560-660 nm, and the relative emission intensity of the second peak 14 is When it is 1.0, the maximum relative emission intensity of peak 15 showing the maximum emission intensity in the wavelength range of 420 to 480 nm is 0.4 to 0.8, further 0.6 to 0.7. It exhibits an emission spectrum ranging from 0.2 to 0.7, or even from 0.3 to 0.6 over the entire range of 520 nm. Further, the illumination device D3 has a third peak indicating a maximum relative emission intensity of 1.0 in the wavelength range of 420 to 480 nm. Emission spectra with a relative emission intensity in the range of 0.2 to 0.7, in particular 0.25 to 0.5 over the entire wavelength range of 520 nm, in the range of 0.3 or more over the wavelength range of 520 to 580 nm indicates In FIG. 11, the illumination device D1 has a first peak indicating the maximum emission intensity in the wavelength range of 420 to 480 nm, and the relative emission intensity of the first peak 11 is set to 1.0. Then, an emission spectrum having a relative emission intensity in the range of 0.2 to 0.7 in the entire wavelength range of 490 to 520 nm and in the range of 0.5 to 0.9 in the entire wavelength range of 560 to 630 nm show. Such a lighting device D1 exhibits an emission spectrum intermediate between that of the lighting devices D2 and D3. Therefore, adjustment can be easily performed by combining and adjusting the LED devices forming the lighting device D2 or the lighting device D3.

The lighting device according to the present embodiment has been described in detail above. Note that the lighting device of the present embodiment is not limited to the configuration described above, and may include other elements or may be modified. Specifically, for example, as the LED device, a blue LED device containing a blue LED element that does not contain a phosphor, a color filter that adjusts the spectral wavelength of the LED device, and a light diffusion for extracting light without color unevenness Materials, light guide members and lens members for controlling light distribution may be combined as necessary.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to Examples. In addition, the scope of the present invention is not limited to the examples.

[Phosphor]
The phosphors used in this example are summarized in Table 1 below.

[Manufacture of LED device]
A phosphor-containing silicone rubber composition was prepared by uniformly dispersing the phosphors F1 to F4 shown in Table 1 and the light diffusing material D (calcium carbonate) in silicone rubber at the compounding ratio shown in Table 2 below. Phosphor-containing caps C1 and C2 with a thickness of 0.3 mm were produced by hot-pressing the composition.

Then, the phosphor-containing cap C1 or C2 is adhered to the light-emitting surface of the blue LED device with a silicone-based adhesive to attach the phosphor-containing LED devices L1 (first LED device) and L2 (second LED device). manufactured. As the blue LED device, "NSSB064 (luminescence peak: 467 nm)" manufactured by Nichia Corporation was used.

[Manufacture of lighting equipment]
As shown in FIG. 2, the LED device L1 (1a) or the LED device L2 (1b) can be mounted with six LED devices L1 (1a) or L2 (1b) at intervals of 15 mm. Either the phosphor-containing LED device L1 or L2 shown in Table 2 was mounted on a strip-shaped surface-mounted circuit board with a width of 10 mm, and a total of six phosphor-containing LED devices were mounted in the combinations shown in Table 3.

Then, the emission spectrum when the lighting devices D1 to D3 are lit by supplying power at a supply current amount of 10 mA to the six phosphor-containing LED devices (L1, L2) mounted in each of the lighting devices D1 to D3. was measured using a spectral irradiance meter (CL-500A manufactured by Konica Minolta, Inc.). Then, the range of relative emission intensity in the wavelength range of 490 to 520 nm and the range of relative emission intensity in the wavelength range of 560 to 630 nm were read. FIG. 11 shows emission spectra of the illumination devices D1 to D3 obtained.

Then, a smartphone (Xperia 8 manufactured by Sony Corporation) having a full HD liquid crystal color display of about 6.0 inches was prepared. The Xperia 8 manufactured by Sony Corporation was adopted as a representative of the various smartphones currently on the market because it shows the average spectral distribution and illuminance. FIG. 14 shows an example of the spectral distribution of each screen display when different types of screen displays (display screens A to D) are displayed on the liquid crystal color display of Xperia 8 manufactured by Sony Corporation.

Then, as shown in FIG. 1, one of the lighting devices D1 to D3 was fixed to the top of the housing of the smartphone. Then, as shown in FIG. 15, the illuminance and color coordinates were measured using a spectral irradiance meter (CL-500A manufactured by Konica Minolta, Inc.) from the center of the HD liquid crystal color display at a measurement distance of 30 cm. Also, the color temperature was calculated. The measurement distance of 30 cm was adopted as the average distance between the eyes and the screen when viewing the smartphone screen. Power was supplied to the six phosphor-containing LED devices (L1, L2) mounted in each of the lighting devices D1 to D3 at current amounts of 10 mA, 20 mA, and 30 mA.

In a dark place, 10 smart phone users were asked to judge the legibility of the HD liquid crystal color display when it was illuminated by any of the lighting devices D1 to D3 based on the following criteria. The amount of supplied current was adjusted by each person within the range of 10 to 30 mA. The decision was then made by majority vote.

(criterion)
A: There is no noticeable discomfort with the color of the liquid crystal color display when the lighting device is not lit, and the glare that causes the eyes to flicker due to the brightness of the screen and the glare that makes them feel uncomfortable is suppressed. I didn't feel tired easily.
B: Although there was an uncomfortable feeling due to a slight change in color, the glare was suppressed and the eyes were less tired.
C: Glare was felt, and the eyes were easily tired.

The evaluation results are shown in Table 4 below.

Referring to Table 4, the color of light produced from the liquid crystal color display illuminated with the illumination device obtained in all the examples was produced from the liquid crystal color display not illuminated with the illumination device of the comparative example. The color temperature is lower than the color, and the glare, which is an unpleasant glare, is reduced. In particular, when the light emitted from the light source unit has a first peak that indicates the maximum emission intensity in the wavelength range of 420 to 480 nm, and the relative emission intensity of the first peak is 1.0, the wavelength is 490 to 490 nm. LED lighting device D1 exhibiting an emission spectrum having a relative emission intensity in the range of 0.2 to 0.7 over the entire range of 520 nm and in the range of 0.5 to 0.9 over the entire wavelength range of 560 to 630 nm. In Examples 1-1, 1-2, 1-3, and 1-4 using It was confirmed that the flickering of the eyes due to brightness and the glare that causes unpleasant glare are suppressed, and the eyes are less tired.

1a, 1b LED device 2 Illumination fixing part 3 Light source module 3a Surface mount circuit board 4 Power supplies 5, 45, 55 Light source parts 10, 20, 30, 40, 50, 60 Illumination devices 12, 22b, 32, 42, 52 Illumination fixing Part 60 Lighting device 100 Smartphone 101, 110 Color display 200 LED device 201 Blue LED element 202 Package member 203 Phosphor 204 Transparent resin sealing material 205 LED device body 209 Phosphor-containing cap

Claims (7)

Used for dimming the color display of information terminal equipment,
An illumination device for illuminating a color display, comprising a light source unit composed of a plurality of LED devices. 2. The illumination device for illuminating the color display according to claim 1, further comprising an illumination fixture for projecting light emitted from said light source towards said color display. Emission from the light source unit has a first peak indicating the maximum emission intensity in the wavelength range of 420 to 480 nm, and when the relative emission intensity of the first peak is 1.0, the wavelength of 490 to 520 nm 3. The method according to claim 1 or 2, exhibiting an emission spectrum having a relative emission intensity in the range of 0.2 to 0.7 over the entire wavelength range and in the range of 0.5 to 0.9 over the entire wavelength range of 560 to 630 nm. An illumination device for illuminating the described color display. the plurality of LED devices each include at least one first LED device and at least one second LED device;
The first LED device has a second peak indicating the maximum emission intensity in the wavelength range of 560 to 660 nm, and when the relative emission intensity of the second peak is 1.0, at a wavelength of 420 to 480 nm The maximum relative emission intensity is 0.4 to 0.8, and the emission spectrum is in the range of 0.2 to 0.7 in the entire wavelength range of 490 to 520 nm,
The second LED device has a third peak indicating the maximum emission intensity in the wavelength range of 420 to 480 nm, and when the relative emission intensity of the third peak is 1.0, the wavelength of 490 to 520 nm Any one of claims 1 to 3, exhibiting an emission spectrum having a relative emission intensity in the range of 0.2 to 0.7 over the entire wavelength range and in the range of 0.3 or more over the entire wavelength range of 520 to 580 nm. An illumination device for illuminating the color display of claim 1. The first LED device includes a first blue LED element and a fluorescent peak wavelength of 80 to 120 nm in a wavelength range of 490 to 530 nm, which emits fluorescence when excited by light emission of the first blue LED element. and a second phosphor having a fluorescence peak wavelength of 100 to 130 nm half-value width in the wavelength range of 510 to 580 nm, and a fluorescence peak wavelength of 60 to 100 nm in the wavelength range of 580 to 680 nm. 5. An illumination device for illuminating a color display as recited in claim 4, comprising: a third phosphor. The second LED device includes a second blue LED element, and a fluorescent peak wavelength of 100 to 130 nm at half maximum in a wavelength range of 510 to 580 nm, which emits fluorescence when excited by light emission of the second blue LED element. and a fourth phosphor having a fluorescence peak wavelength with a half-value width of 50 to 80 nm in the wavelength range of 430 to 490 nm, for illuminating a color display according to claim 4 or 5 lighting system. 7. An illumination device for illuminating a color display according to claim 1, wherein said information terminal equipment is a smart phone, a tablet information terminal equipment, a car navigation equipment, a laptop computer, or an instrument panel. .

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