JP5923738B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device.

  In recent years, light-emitting diodes (hereinafter referred to as LEDs) have been adopted as light sources for lighting fixtures and the like because they can contribute to power saving compared to incandescent lamps and fluorescent lamps (see, for example, Patent Document 1).

JP 2011-66314 A

  By the way, the lens may become clouded with age, and the light entering the eyeball from the outside may cause the eyeball to scatter inside the lens, resulting in dazzling feelings and difficult to read characters. To do. The intraocular scattering is more likely to occur with light having a shorter wavelength component, and the degree of influence (scattering intensity) is inversely proportional to the fourth power of the wavelength of light (Rayleigh scattering).

  The brightness perceived by a person is a value obtained by multiplying the physical energy intensity of the light generated from the light source by the spectral luminous efficiency. Here, the spectral luminous efficiency is a maximum curve at 555 nm, and the efficiency is only 10% or less of 555 nm below 470 nm. That is, even if light of 470 nm or less is reduced, it can be said that the influence on the brightness felt by humans is small.

  Therefore, for example, as a means for suppressing light having a relatively short wavelength of 470 nm or less, a method using a color filter that suppresses light having a short wavelength component such as sunglasses can be considered. However, if light of a short wavelength component is simply dimmed out of the light from the white light source, the light color of the light source changes from white to yellowish light, which may make it difficult to read characters and the like.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an illuminating device capable of suppressing a decrease in readability of characters while reducing glare.

In order to solve the above problem, a lighting device of the present invention, a white light source having an LED element, a light reducing unit to reduce the wavelength of 4 70 nm or less among the light in the visible light region emitted from the white light source 480 And a light adjusting portion having a light adding portion having an emission peak in a range of ˜485 nm.

Moreover, the said structure WHEREIN: It is preferable that the said light reduction part is a band pass filter which reduces the wavelength of 470 nm or less among the lights of the visible light area radiate | emitted from the said white light source .
Further, in the above configuration, the light adjustment unit is a wavelength conversion phosphor that absorbs light of 470 nm or less among light in a visible light region emitted from the white light source and has an emission peak in a range of 480 nm to 485 nm. It is preferable.

  Moreover, the said structure WHEREIN: The said white light source is provided with the said LED element and fluorescent substance, It is preferable that the LED element of the said white light source is a blue LED element, and the fluorescent substance of the said white light source is a yellow fluorescent substance.

  Further, in the above configuration, the white light source includes the LED element and a phosphor, the LED element of the white light source is an ultraviolet LED element, and the phosphor of the white light source receives light of the ultraviolet LED and combines light It is preferable that the phosphor is excited so as to be white light.

  ADVANTAGE OF THE INVENTION According to this invention, the illuminating device which provides the illuminating device which can suppress the fall of the readability of a character, reducing glare can be provided.

It is a schematic block diagram of the illuminating device in embodiment. It is a characteristic view of the spectrum of the illuminating device of embodiment, and the spectrum of the illuminating device of a comparative example. It is a characteristic view of a band pass filter. It is explanatory drawing for demonstrating the color deviation Duv and whiteness of a comparative example and embodiment. It is a schematic block diagram of the illuminating device in another example.

(First embodiment)
Hereinafter, 1st Embodiment of an illuminating device is described according to drawing.
As shown in FIG. 1, the illumination device 10 of the present embodiment includes a light emitting unit 11 and a lighting circuit 12 for lighting the light emitting unit 11.

  As shown in FIG. 1, the light emitting unit 11 receives the light from the LED element 21a in a state where a predetermined gap is provided between the LED element 21a electrically connected to the lighting circuit 12 and the LED element 21a. A white light source 21 having a phosphor 21b that emits yellow (yellowish green) light. The LED element 21a is a blue LED element, and has a peak wavelength at which the emission intensity is maximum at about 450 nm. The phosphor 21b receives the light from the LED element 21a and has a peak wavelength at which the emission intensity is maximum at about 555 nm.

As shown in FIG. 1, in addition to the white light source 21, the light emitting unit 11 includes an LED element 22 having a peak wavelength with a maximum light emission intensity in the range of 480 to 485 nm. The LED element 22 is electrically connected to the lighting circuit 12. The LED element 22 may be an InGaN-based LED that is a gallium nitride-based LED.

  As shown in FIG. 1, a band-pass filter 23 that reduces the wavelength of 470 nm or less is provided in front of the light emitting unit 11. As shown in FIG. 3, the bandpass filter 23 is a bandpass filter that reduces light having a wavelength of 470 nm or less in the visible light region to an average of 75%, that is, an average transmittance of 75%. As such a band pass filter 23, for example, a glass or acrylic with high light transmittance coated with ITO (indium tin oxide) can be used.

Next, the effect | action of the illuminating device 10 of this embodiment is described.
In the lighting device 10 configured as described above, power is supplied from the lighting circuit 12 to the LED element 21a and the LED element 22, the LED element 21a is lit in blue near purple, and the LED element 22 is blue near green. Lights up. At this time, in response to the light from the LED element 21a, the phosphor 21b is excited to emit yellow light. The light emitted from the LED elements 21 a and 22 and the phosphor 21 b is reduced by the bandpass filter 23 to light of 470 nm or less (visible light) to 75%. The illumination device 10 is irradiated with light having a spectral characteristic as shown by a solid line in FIG.

  Here, in the case of a general white LED (substantially the same configuration as the white light source 21) as shown in FIG. 4, the color deviation Duv representing the deviation from the black body radiation locus is about 2, and the whiteness Is about 11.0. If the light of 470 nm or less is reduced to 75% using the bandpass filter 23 as described above, the value of whiteness is increased to about 12.5 and the whiteness is impaired. Therefore, by adding the LED element 22 having a peak wavelength in the range of 480 to 485 nm as in the present embodiment, the whiteness value is set to about 10.4, and the whiteness feeling is made into a general white LED. The

Next, the effect of this embodiment will be described.
(1) The illuminating device 10 of this embodiment is provided with the white light source 21 which has the LED element 21a, and the light adjustment part. The light adjusting unit includes a bandpass filter 23 as a light reducing unit that reduces at least a wavelength of 470 nm or less among the light emitted from the white light source 21, and an LED as a light adding unit having a light emission peak in a range of 480 to 485 nm. Element 22.

(2) In the present embodiment, the band-pass filter 23 that reduces at least a wavelength of 470 nm or less is employed, and the light reduction unit can be configured relatively simply.
(3) The white light source 21 includes the LED element 21a and the phosphor 21b, the LED element 21a of the white light source 21 is a blue LED element, and the phosphor 21b of the white light source 21 is a yellow phosphor. By setting it as such a structure, it can be set as a structure simpler than the white light source provided with the blue LED element, the green LED element, and the red LED element, for example. Moreover, by setting it as the above structures, it can be set as a simple structure compared with the structure which adds a green fluorescent substance and a red fluorescent substance in addition to a blue LED element, for example.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the light adjustment unit is configured by the band-pass filter 23 and the LED element 22, but is not limited thereto. For example, as shown in FIG. 5, the light intensity of 470 nm to 485 nm is maximized in the range of 480 nm to 485 nm by absorbing light of 470 nm or less among the light emitted from the white light source 21 in front of the white light source 21 (irradiation surface side). A wavelength conversion phosphor 31 that emits light having a peak wavelength may be employed as the light adjusting unit. As such a wavelength conversion phosphor 31, for example, a silicate phosphor can be employed. With such a configuration, for example, light that has been dimmed by the bandpass filter 23 can be used effectively, which can contribute to improvement in light emission efficiency.

  In the above embodiment, the white light source 21 is configured by the LED element 21a that emits blue light and the phosphor 21b that is excited by the light of the LED element 21a and emits yellow light. However, the present invention is not limited thereto.

  For example, an ultraviolet LED element that emits light having a shorter wavelength than blue is adopted as the LED element of the white light source 21, and the blue light that is excited by the ultraviolet LED element as the phosphor of the white light source 21 so that the combined light becomes white light. A phosphor and a yellow phosphor may be employed. In addition, as the phosphor of the white light source 21, a red phosphor, a green phosphor, and a blue phosphor may be employed so that the synthesized light is excited so as to become white light. In this way, by using invisible ultraviolet rays, blue light can be reproduced by a phosphor instead of an LED, so color rendering properties and color temperature settings can be set more freely, and the degree of freedom in design Can be increased.

In the above embodiment, the dimming unit is configured by one bandpass filter 23, but the dimming unit may be configured by combining a plurality of bandpass filters.
In the above embodiment, the bandpass filter having a 75% average transmittance in the range of 380 to 470 nm is used, but the average transmittance is not particularly limited.

  In the above embodiment, the LED element 21a that emits blue light with a peak wavelength of about 450 nm is used. However, the peak wavelength of the LED element 21a may be changed to, for example, 440 nm or 460 nm. Moreover, although the peak wavelength of the phosphor 21b is 555 nm, the peak wavelength is not limited to this, and may be changed to, for example, 550 nm or 560 nm.

  In the above embodiment, the white light source 21 is composed of one LED element 21a and one phosphor 21b, but the number thereof may be arbitrarily changed. A configuration in which a plurality of white light sources 21 are simply provided may be employed.

  DESCRIPTION OF SYMBOLS 10 ... Illuminating device, 21 ... White light source, 21a ... LED element which comprises a white light source, 21b ... Phosphor which comprises a white light source, 22 ... LED element as a light addition part, 23 ... Band pass filter as a light reduction part 31 ... Wavelength conversion phosphor as a light adjusting unit.

Claims (5)

A white light source having an LED element;
A light adjustment part having a light adding unit having an emission peak in the range of dimming section and 480~485nm reduce the wavelength of 4 70 nm or less among the light in the visible light region emitted from the white light source,
An illumination device comprising: The lighting device according to claim 1.
The illumination device according to claim 1, wherein the dimming unit is a band-pass filter that subtracts a wavelength of 470 nm or less from light in a visible light region emitted from the white light source . The lighting device according to claim 1.
The light adjusting unit is a wavelength conversion phosphor that absorbs light of 470 nm or less among light in a visible light region emitted from the white light source and has an emission peak in a range of 480 nm to 485 nm. Lighting device. In the illuminating device as described in any one of Claims 1-3,
The white light source includes the LED element and a phosphor.
The LED device of the white light source is a blue LED device, and the phosphor of the white light source is a yellow phosphor. In the illuminating device as described in any one of Claims 1-3,
The white light source includes the LED element and a phosphor.
The LED element of the white light source is an ultraviolet LED element, and the phosphor of the white light source is a phosphor that receives light from the ultraviolet LED and is excited so that the combined light becomes white light. apparatus.